diff options
Diffstat (limited to 'drivers/gpio/gpiolib.c')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 1954 |
1 files changed, 1245 insertions, 709 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 44c8f5743a24..fdafa0df1b43 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1,7 +1,9 @@ // SPDX-License-Identifier: GPL-2.0 #include <linux/acpi.h> +#include <linux/array_size.h> #include <linux/bitmap.h> +#include <linux/cleanup.h> #include <linux/compat.h> #include <linux/debugfs.h> #include <linux/device.h> @@ -12,15 +14,19 @@ #include <linux/idr.h> #include <linux/interrupt.h> #include <linux/irq.h> +#include <linux/irqdesc.h> #include <linux/kernel.h> #include <linux/list.h> +#include <linux/lockdep.h> #include <linux/module.h> +#include <linux/nospec.h> #include <linux/of.h> #include <linux/pinctrl/consumer.h> #include <linux/seq_file.h> #include <linux/slab.h> -#include <linux/spinlock.h> +#include <linux/srcu.h> #include <linux/string.h> +#include <linux/string_choices.h> #include <linux/gpio.h> #include <linux/gpio/driver.h> @@ -50,7 +56,7 @@ static DEFINE_IDA(gpio_ida); static dev_t gpio_devt; #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */ -static int gpio_bus_match(struct device *dev, struct device_driver *drv) +static int gpio_bus_match(struct device *dev, const struct device_driver *drv) { struct fwnode_handle *fwnode = dev_fwnode(dev); @@ -63,7 +69,7 @@ static int gpio_bus_match(struct device *dev, struct device_driver *drv) return 1; } -static struct bus_type gpio_bus_type = { +static const struct bus_type gpio_bus_type = { .name = "gpio", .match = gpio_bus_match, }; @@ -73,19 +79,20 @@ static struct bus_type gpio_bus_type = { */ #define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT -/* gpio_lock prevents conflicts during gpio_desc[] table updates. - * While any GPIO is requested, its gpio_chip is not removable; - * each GPIO's "requested" flag serves as a lock and refcount. - */ -DEFINE_SPINLOCK(gpio_lock); - static DEFINE_MUTEX(gpio_lookup_lock); static LIST_HEAD(gpio_lookup_list); -LIST_HEAD(gpio_devices); + +static LIST_HEAD(gpio_devices); +/* Protects the GPIO device list against concurrent modifications. */ +static DEFINE_MUTEX(gpio_devices_lock); +/* Ensures coherence during read-only accesses to the list of GPIO devices. */ +DEFINE_STATIC_SRCU(gpio_devices_srcu); static DEFINE_MUTEX(gpio_machine_hogs_mutex); static LIST_HEAD(gpio_machine_hogs); +const char *const gpio_suffixes[] = { "gpios", "gpio", NULL }; + static void gpiochip_free_hogs(struct gpio_chip *gc); static int gpiochip_add_irqchip(struct gpio_chip *gc, struct lock_class_key *lock_key, @@ -97,9 +104,48 @@ static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc); static bool gpiolib_initialized; -static inline void desc_set_label(struct gpio_desc *d, const char *label) +const char *gpiod_get_label(struct gpio_desc *desc) { - d->label = label; + struct gpio_desc_label *label; + unsigned long flags; + + flags = READ_ONCE(desc->flags); + + label = srcu_dereference_check(desc->label, &desc->gdev->desc_srcu, + srcu_read_lock_held(&desc->gdev->desc_srcu)); + + if (test_bit(FLAG_USED_AS_IRQ, &flags)) + return label ? label->str : "interrupt"; + + if (!test_bit(FLAG_REQUESTED, &flags)) + return NULL; + + return label ? label->str : NULL; +} + +static void desc_free_label(struct rcu_head *rh) +{ + kfree(container_of(rh, struct gpio_desc_label, rh)); +} + +static int desc_set_label(struct gpio_desc *desc, const char *label) +{ + struct gpio_desc_label *new = NULL, *old; + + if (label) { + new = kzalloc(struct_size(new, str, strlen(label) + 1), + GFP_KERNEL); + if (!new) + return -ENOMEM; + + strcpy(new->str, label); + } + + old = rcu_replace_pointer(desc->label, new, 1); + if (old) + call_srcu(&desc->gdev->desc_srcu, &old->rh, desc_free_label); + + return 0; } /** @@ -113,23 +159,16 @@ static inline void desc_set_label(struct gpio_desc *d, const char *label) struct gpio_desc *gpio_to_desc(unsigned gpio) { struct gpio_device *gdev; - unsigned long flags; - - spin_lock_irqsave(&gpio_lock, flags); - list_for_each_entry(gdev, &gpio_devices, list) { - if (gdev->base <= gpio && - gdev->base + gdev->ngpio > gpio) { - spin_unlock_irqrestore(&gpio_lock, flags); - return &gdev->descs[gpio - gdev->base]; + scoped_guard(srcu, &gpio_devices_srcu) { + list_for_each_entry_srcu(gdev, &gpio_devices, list, + srcu_read_lock_held(&gpio_devices_srcu)) { + if (gdev->base <= gpio && + gdev->base + gdev->ngpio > gpio) + return &gdev->descs[gpio - gdev->base]; } } - spin_unlock_irqrestore(&gpio_lock, flags); - - if (!gpio_is_valid(gpio)) - pr_warn("invalid GPIO %d\n", gpio); - return NULL; } EXPORT_SYMBOL_GPL(gpio_to_desc); @@ -140,7 +179,6 @@ struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, { return gpio_device_get_desc(gc->gpiodev, hwnum); } -EXPORT_SYMBOL_GPL(gpiochip_get_desc); /** * gpio_device_get_desc() - get the GPIO descriptor corresponding to the given @@ -161,20 +199,10 @@ EXPORT_SYMBOL_GPL(gpiochip_get_desc); struct gpio_desc * gpio_device_get_desc(struct gpio_device *gdev, unsigned int hwnum) { - struct gpio_chip *gc; - - /* - * FIXME: This will be locked once we protect gdev->chip everywhere - * with SRCU. - */ - gc = gdev->chip; - if (!gc) - return ERR_PTR(-ENODEV); - if (hwnum >= gdev->ngpio) return ERR_PTR(-EINVAL); - return &gdev->descs[hwnum]; + return &gdev->descs[array_index_nospec(hwnum, gdev->ngpio)]; } EXPORT_SYMBOL_GPL(gpio_device_get_desc); @@ -198,12 +226,21 @@ EXPORT_SYMBOL_GPL(desc_to_gpio); /** * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs * @desc: descriptor to return the chip of + * + * *DEPRECATED* + * This function is unsafe and should not be used. Using the chip address + * without taking the SRCU read lock may result in dereferencing a dangling + * pointer. + * + * Returns: + * Address of the GPIO chip backing this device. */ struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc) { - if (!desc || !desc->gdev) + if (!desc) return NULL; - return desc->gdev->chip; + + return gpio_device_get_chip(desc->gdev); } EXPORT_SYMBOL_GPL(gpiod_to_chip); @@ -229,6 +266,20 @@ struct gpio_device *gpiod_to_gpio_device(struct gpio_desc *desc) EXPORT_SYMBOL_GPL(gpiod_to_gpio_device); /** + * gpiod_is_equal() - Check if two GPIO descriptors refer to the same pin. + * @desc: Descriptor to compare. + * @other: The second descriptor to compare against. + * + * Returns: + * True if the descriptors refer to the same physical pin. False otherwise. + */ +bool gpiod_is_equal(struct gpio_desc *desc, struct gpio_desc *other) +{ + return desc == other; +} +EXPORT_SYMBOL_GPL(gpiod_is_equal); + +/** * gpio_device_get_base() - Get the base GPIO number allocated by this device * @gdev: GPIO device * @@ -262,6 +313,7 @@ EXPORT_SYMBOL(gpio_device_get_label); * Returns: * Address of the GPIO chip backing this device. * + * *DEPRECATED* * Until we can get rid of all non-driver users of struct gpio_chip, we must * provide a way of retrieving the pointer to it from struct gpio_device. This * is *NOT* safe as the GPIO API is considered to be hot-unpluggable and the @@ -272,17 +324,18 @@ EXPORT_SYMBOL(gpio_device_get_label); */ struct gpio_chip *gpio_device_get_chip(struct gpio_device *gdev) { - return gdev->chip; + return rcu_dereference_check(gdev->chip, 1); } EXPORT_SYMBOL_GPL(gpio_device_get_chip); /* dynamic allocation of GPIOs, e.g. on a hotplugged device */ -static int gpiochip_find_base_unlocked(int ngpio) +static int gpiochip_find_base_unlocked(u16 ngpio) { + unsigned int base = GPIO_DYNAMIC_BASE; struct gpio_device *gdev; - int base = GPIO_DYNAMIC_BASE; - list_for_each_entry(gdev, &gpio_devices, list) { + list_for_each_entry_srcu(gdev, &gpio_devices, list, + lockdep_is_held(&gpio_devices_lock)) { /* found a free space? */ if (gdev->base >= base + ngpio) break; @@ -290,9 +343,11 @@ static int gpiochip_find_base_unlocked(int ngpio) base = gdev->base + gdev->ngpio; if (base < GPIO_DYNAMIC_BASE) base = GPIO_DYNAMIC_BASE; + if (base > GPIO_DYNAMIC_MAX - ngpio) + break; } - if (gpio_is_valid(base)) { + if (base <= GPIO_DYNAMIC_MAX - ngpio) { pr_debug("%s: found new base at %d\n", __func__, base); return base; } else { @@ -301,43 +356,106 @@ static int gpiochip_find_base_unlocked(int ngpio) } } +/* + * This descriptor validation needs to be inserted verbatim into each + * function taking a descriptor, so we need to use a preprocessor + * macro to avoid endless duplication. If the desc is NULL it is an + * optional GPIO and calls should just bail out. + */ +static int validate_desc(const struct gpio_desc *desc, const char *func) +{ + if (!desc) + return 0; + + if (IS_ERR(desc)) { + pr_warn("%s: invalid GPIO (errorpointer: %pe)\n", func, desc); + return PTR_ERR(desc); + } + + return 1; +} + +#define VALIDATE_DESC(desc) do { \ + int __valid = validate_desc(desc, __func__); \ + if (__valid <= 0) \ + return __valid; \ + } while (0) + +#define VALIDATE_DESC_VOID(desc) do { \ + int __valid = validate_desc(desc, __func__); \ + if (__valid <= 0) \ + return; \ + } while (0) + +static int gpiochip_get_direction(struct gpio_chip *gc, unsigned int offset) +{ + int ret; + + lockdep_assert_held(&gc->gpiodev->srcu); + + if (WARN_ON(!gc->get_direction)) + return -EOPNOTSUPP; + + ret = gc->get_direction(gc, offset); + if (ret < 0) + return ret; + + if (ret != GPIO_LINE_DIRECTION_OUT && ret != GPIO_LINE_DIRECTION_IN) + ret = -EBADE; + + return ret; +} + /** * gpiod_get_direction - return the current direction of a GPIO * @desc: GPIO to get the direction of * - * Returns 0 for output, 1 for input, or an error code in case of error. + * Returns: + * 0 for output, 1 for input, or an error code in case of error. * * This function may sleep if gpiod_cansleep() is true. */ int gpiod_get_direction(struct gpio_desc *desc) { - struct gpio_chip *gc; + unsigned long flags; unsigned int offset; int ret; - gc = gpiod_to_chip(desc); + ret = validate_desc(desc, __func__); + if (ret <= 0) + return -EINVAL; + + CLASS(gpio_chip_guard, guard)(desc); + if (!guard.gc) + return -ENODEV; + offset = gpio_chip_hwgpio(desc); + flags = READ_ONCE(desc->flags); /* * Open drain emulation using input mode may incorrectly report * input here, fix that up. */ - if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && - test_bit(FLAG_IS_OUT, &desc->flags)) + if (test_bit(FLAG_OPEN_DRAIN, &flags) && + test_bit(FLAG_IS_OUT, &flags)) return 0; - if (!gc->get_direction) + if (!guard.gc->get_direction) return -ENOTSUPP; - ret = gc->get_direction(gc, offset); + ret = gpiochip_get_direction(guard.gc, offset); if (ret < 0) return ret; - /* GPIOF_DIR_IN or other positive, otherwise GPIOF_DIR_OUT */ + /* + * GPIO_LINE_DIRECTION_IN or other positive, + * otherwise GPIO_LINE_DIRECTION_OUT. + */ if (ret > 0) ret = 1; - assign_bit(FLAG_IS_OUT, &desc->flags, !ret); + assign_bit(FLAG_IS_OUT, &flags, !ret); + WRITE_ONCE(desc->flags, flags); return ret; } @@ -347,30 +465,32 @@ EXPORT_SYMBOL_GPL(gpiod_get_direction); * Add a new chip to the global chips list, keeping the list of chips sorted * by range(means [base, base + ngpio - 1]) order. * - * Return -EBUSY if the new chip overlaps with some other chip's integer - * space. + * Returns: + * -EBUSY if the new chip overlaps with some other chip's integer space. */ static int gpiodev_add_to_list_unlocked(struct gpio_device *gdev) { struct gpio_device *prev, *next; + lockdep_assert_held(&gpio_devices_lock); + if (list_empty(&gpio_devices)) { /* initial entry in list */ - list_add_tail(&gdev->list, &gpio_devices); + list_add_tail_rcu(&gdev->list, &gpio_devices); return 0; } next = list_first_entry(&gpio_devices, struct gpio_device, list); if (gdev->base + gdev->ngpio <= next->base) { /* add before first entry */ - list_add(&gdev->list, &gpio_devices); + list_add_rcu(&gdev->list, &gpio_devices); return 0; } prev = list_last_entry(&gpio_devices, struct gpio_device, list); if (prev->base + prev->ngpio <= gdev->base) { /* add behind last entry */ - list_add_tail(&gdev->list, &gpio_devices); + list_add_tail_rcu(&gdev->list, &gpio_devices); return 0; } @@ -382,11 +502,13 @@ static int gpiodev_add_to_list_unlocked(struct gpio_device *gdev) /* add between prev and next */ if (prev->base + prev->ngpio <= gdev->base && gdev->base + gdev->ngpio <= next->base) { - list_add(&gdev->list, &prev->list); + list_add_rcu(&gdev->list, &prev->list); return 0; } } + synchronize_srcu(&gpio_devices_srcu); + return -EBUSY; } @@ -399,26 +521,28 @@ static int gpiodev_add_to_list_unlocked(struct gpio_device *gdev) static struct gpio_desc *gpio_name_to_desc(const char * const name) { struct gpio_device *gdev; - unsigned long flags; + struct gpio_desc *desc; + struct gpio_chip *gc; if (!name) return NULL; - spin_lock_irqsave(&gpio_lock, flags); + guard(srcu)(&gpio_devices_srcu); + + list_for_each_entry_srcu(gdev, &gpio_devices, list, + srcu_read_lock_held(&gpio_devices_srcu)) { + guard(srcu)(&gdev->srcu); - list_for_each_entry(gdev, &gpio_devices, list) { - struct gpio_desc *desc; + gc = srcu_dereference(gdev->chip, &gdev->srcu); + if (!gc) + continue; - for_each_gpio_desc(gdev->chip, desc) { - if (desc->name && !strcmp(desc->name, name)) { - spin_unlock_irqrestore(&gpio_lock, flags); + for_each_gpio_desc(gc, desc) { + if (desc->name && !strcmp(desc->name, name)) return desc; - } } } - spin_unlock_irqrestore(&gpio_lock, flags); - return NULL; } @@ -430,7 +554,7 @@ static struct gpio_desc *gpio_name_to_desc(const char * const name) * 1. Non-unique names are still accepted, * 2. Name collisions within the same GPIO chip are not reported. */ -static int gpiochip_set_desc_names(struct gpio_chip *gc) +static void gpiochip_set_desc_names(struct gpio_chip *gc) { struct gpio_device *gdev = gc->gpiodev; int i; @@ -449,8 +573,6 @@ static int gpiochip_set_desc_names(struct gpio_chip *gc) /* Then add all names to the GPIO descriptors */ for (i = 0; i != gc->ngpio; ++i) gdev->descs[i].name = gc->names[i]; - - return 0; } /* @@ -592,7 +714,7 @@ static int gpiochip_apply_reserved_ranges(struct gpio_chip *gc) if (start >= gc->ngpio || start + count > gc->ngpio) continue; - bitmap_clear(gc->valid_mask, start, count); + bitmap_clear(gc->gpiodev->valid_mask, start, count); } kfree(ranges); @@ -606,8 +728,8 @@ static int gpiochip_init_valid_mask(struct gpio_chip *gc) if (!(gpiochip_count_reserved_ranges(gc) || gc->init_valid_mask)) return 0; - gc->valid_mask = gpiochip_allocate_mask(gc); - if (!gc->valid_mask) + gc->gpiodev->valid_mask = gpiochip_allocate_mask(gc); + if (!gc->gpiodev->valid_mask) return -ENOMEM; ret = gpiochip_apply_reserved_ranges(gc); @@ -616,7 +738,7 @@ static int gpiochip_init_valid_mask(struct gpio_chip *gc) if (gc->init_valid_mask) return gc->init_valid_mask(gc, - gc->valid_mask, + gc->gpiodev->valid_mask, gc->ngpio); return 0; @@ -624,7 +746,7 @@ static int gpiochip_init_valid_mask(struct gpio_chip *gc) static void gpiochip_free_valid_mask(struct gpio_chip *gc) { - gpiochip_free_mask(&gc->valid_mask); + gpiochip_free_mask(&gc->gpiodev->valid_mask); } static int gpiochip_add_pin_ranges(struct gpio_chip *gc) @@ -643,26 +765,97 @@ static int gpiochip_add_pin_ranges(struct gpio_chip *gc) return 0; } +/** + * gpiochip_query_valid_mask - return the GPIO validity information + * @gc: gpio chip which validity information is queried + * + * Returns: bitmap representing valid GPIOs or NULL if all GPIOs are valid + * + * Some GPIO chips may support configurations where some of the pins aren't + * available. These chips can have valid_mask set to represent the valid + * GPIOs. This function can be used to retrieve this information. + */ +const unsigned long *gpiochip_query_valid_mask(const struct gpio_chip *gc) +{ + return gc->gpiodev->valid_mask; +} +EXPORT_SYMBOL_GPL(gpiochip_query_valid_mask); + bool gpiochip_line_is_valid(const struct gpio_chip *gc, unsigned int offset) { + /* + * hog pins are requested before registering GPIO chip + */ + if (!gc->gpiodev) + return true; + /* No mask means all valid */ - if (likely(!gc->valid_mask)) + if (likely(!gc->gpiodev->valid_mask)) return true; - return test_bit(offset, gc->valid_mask); + return test_bit(offset, gc->gpiodev->valid_mask); } EXPORT_SYMBOL_GPL(gpiochip_line_is_valid); +static void gpiod_free_irqs(struct gpio_desc *desc) +{ + int irq = gpiod_to_irq(desc); + struct irq_desc *irqd = irq_to_desc(irq); + void *cookie; + + for (;;) { + /* + * Make sure the action doesn't go away while we're + * dereferencing it. Retrieve and store the cookie value. + * If the irq is freed after we release the lock, that's + * alright - the underlying maple tree lookup will return NULL + * and nothing will happen in free_irq(). + */ + scoped_guard(mutex, &irqd->request_mutex) { + if (!irq_desc_has_action(irqd)) + return; + + cookie = irqd->action->dev_id; + } + + free_irq(irq, cookie); + } +} + +/* + * The chip is going away but there may be users who had requested interrupts + * on its GPIO lines who have no idea about its removal and have no way of + * being notified about it. We need to free any interrupts still in use here or + * we'll leak memory and resources (like procfs files). + */ +static void gpiochip_free_remaining_irqs(struct gpio_chip *gc) +{ + struct gpio_desc *desc; + + for_each_gpio_desc_with_flag(gc, desc, FLAG_USED_AS_IRQ) + gpiod_free_irqs(desc); +} + static void gpiodev_release(struct device *dev) { struct gpio_device *gdev = to_gpio_device(dev); + /* Call pending kfree()s for descriptor labels. */ + synchronize_srcu(&gdev->desc_srcu); + cleanup_srcu_struct(&gdev->desc_srcu); + ida_free(&gpio_ida, gdev->id); kfree_const(gdev->label); kfree(gdev->descs); + cleanup_srcu_struct(&gdev->srcu); kfree(gdev); } +static const struct device_type gpio_dev_type = { + .name = "gpio_chip", + .release = gpiodev_release, +}; + #ifdef CONFIG_GPIO_CDEV #define gcdev_register(gdev, devt) gpiolib_cdev_register((gdev), (devt)) #define gcdev_unregister(gdev) gpiolib_cdev_unregister((gdev)) @@ -680,6 +873,8 @@ static int gpiochip_setup_dev(struct gpio_device *gdev) struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev); int ret; + device_initialize(&gdev->dev); + /* * If fwnode doesn't belong to another device, it's safe to clear its * initialized flag. @@ -691,15 +886,12 @@ static int gpiochip_setup_dev(struct gpio_device *gdev) if (ret) return ret; - /* From this point, the .release() function cleans up gpio_device */ - gdev->dev.release = gpiodev_release; - ret = gpiochip_sysfs_register(gdev); if (ret) goto err_remove_device; - dev_dbg(&gdev->dev, "registered GPIOs %d to %d on %s\n", gdev->base, - gdev->base + gdev->ngpio - 1, gdev->chip->label ? : "generic"); + dev_dbg(&gdev->dev, "registered GPIOs %u to %u on %s\n", gdev->base, + gdev->base + gdev->ngpio - 1, gdev->label); return 0; @@ -720,9 +912,6 @@ static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog) return; } - if (test_bit(FLAG_IS_HOGGED, &desc->flags)) - return; - rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags); if (rv) gpiod_err(desc, "%s: unable to hog GPIO line (%s:%u): %d\n", @@ -733,14 +922,12 @@ static void machine_gpiochip_add(struct gpio_chip *gc) { struct gpiod_hog *hog; - mutex_lock(&gpio_machine_hogs_mutex); + guard(mutex)(&gpio_machine_hogs_mutex); list_for_each_entry(hog, &gpio_machine_hogs, list) { if (!strcmp(gc->label, hog->chip_label)) gpiochip_machine_hog(gc, hog); } - - mutex_unlock(&gpio_machine_hogs_mutex); } static void gpiochip_setup_devs(void) @@ -748,7 +935,10 @@ static void gpiochip_setup_devs(void) struct gpio_device *gdev; int ret; - list_for_each_entry(gdev, &gpio_devices, list) { + guard(srcu)(&gpio_devices_srcu); + + list_for_each_entry_srcu(gdev, &gpio_devices, list, + srcu_read_lock_held(&gpio_devices_srcu)) { ret = gpiochip_setup_dev(gdev); if (ret) dev_err(&gdev->dev, @@ -774,13 +964,29 @@ void *gpiochip_get_data(struct gpio_chip *gc) } EXPORT_SYMBOL_GPL(gpiochip_get_data); +/* + * If the calling driver provides the specific firmware node, + * use it. Otherwise use the one from the parent device, if any. + */ +static struct fwnode_handle *gpiochip_choose_fwnode(struct gpio_chip *gc) +{ + if (gc->fwnode) + return gc->fwnode; + + if (gc->parent) + return dev_fwnode(gc->parent); + + return NULL; +} + int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev) { + struct fwnode_handle *fwnode = gpiochip_choose_fwnode(gc); u32 ngpios = gc->ngpio; int ret; if (ngpios == 0) { - ret = device_property_read_u32(dev, "ngpios", &ngpios); + ret = fwnode_property_read_u32(fwnode, "ngpios", &ngpios); if (ret == -ENODATA) /* * -ENODATA means that there is no property found and @@ -796,13 +1002,13 @@ int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev) } if (gc->ngpio == 0) { - chip_err(gc, "tried to insert a GPIO chip with zero lines\n"); + dev_err(dev, "tried to insert a GPIO chip with zero lines\n"); return -EINVAL; } if (gc->ngpio > FASTPATH_NGPIO) - chip_warn(gc, "line cnt %u is greater than fast path cnt %u\n", - gc->ngpio, FASTPATH_NGPIO); + dev_warn(dev, "line cnt %u is greater than fast path cnt %u\n", + gc->ngpio, FASTPATH_NGPIO); return 0; } @@ -813,10 +1019,14 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, struct lock_class_key *request_key) { struct gpio_device *gdev; - unsigned long flags; - unsigned int i; + unsigned int desc_index; int base = 0; - int ret = 0; + int ret; + + /* Only allow one set() and one set_multiple(). */ + if ((gc->set && gc->set_rv) || + (gc->set_multiple && gc->set_multiple_rv)) + return -EINVAL; /* * First: allocate and populate the internal stat container, and @@ -825,33 +1035,26 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, gdev = kzalloc(sizeof(*gdev), GFP_KERNEL); if (!gdev) return -ENOMEM; + + gdev->dev.type = &gpio_dev_type; gdev->dev.bus = &gpio_bus_type; gdev->dev.parent = gc->parent; - gdev->chip = gc; + rcu_assign_pointer(gdev->chip, gc); gc->gpiodev = gdev; gpiochip_set_data(gc, data); - /* - * If the calling driver did not initialize firmware node, - * do it here using the parent device, if any. - */ - if (gc->fwnode) - device_set_node(&gdev->dev, gc->fwnode); - else if (gc->parent) - device_set_node(&gdev->dev, dev_fwnode(gc->parent)); + device_set_node(&gdev->dev, gpiochip_choose_fwnode(gc)); - gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL); - if (gdev->id < 0) { - ret = gdev->id; + ret = ida_alloc(&gpio_ida, GFP_KERNEL); + if (ret < 0) goto err_free_gdev; - } + gdev->id = ret; ret = dev_set_name(&gdev->dev, GPIOCHIP_NAME "%d", gdev->id); if (ret) goto err_free_ida; - device_initialize(&gdev->dev); if (gc->parent && gc->parent->driver) gdev->owner = gc->parent->driver->owner; else if (gc->owner) @@ -877,87 +1080,97 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, } gdev->ngpio = gc->ngpio; + gdev->can_sleep = gc->can_sleep; - spin_lock_irqsave(&gpio_lock, flags); - - /* - * TODO: this allocates a Linux GPIO number base in the global - * GPIO numberspace for this chip. In the long run we want to - * get *rid* of this numberspace and use only descriptors, but - * it may be a pipe dream. It will not happen before we get rid - * of the sysfs interface anyways. - */ - base = gc->base; - if (base < 0) { - base = gpiochip_find_base_unlocked(gc->ngpio); - if (base < 0) { - spin_unlock_irqrestore(&gpio_lock, flags); - ret = base; - base = 0; - goto err_free_label; - } + scoped_guard(mutex, &gpio_devices_lock) { /* - * TODO: it should not be necessary to reflect the assigned - * base outside of the GPIO subsystem. Go over drivers and - * see if anyone makes use of this, else drop this and assign - * a poison instead. + * TODO: this allocates a Linux GPIO number base in the global + * GPIO numberspace for this chip. In the long run we want to + * get *rid* of this numberspace and use only descriptors, but + * it may be a pipe dream. It will not happen before we get rid + * of the sysfs interface anyways. */ - gc->base = base; - } else { - dev_warn(&gdev->dev, - "Static allocation of GPIO base is deprecated, use dynamic allocation.\n"); - } - gdev->base = base; + base = gc->base; + if (base < 0) { + base = gpiochip_find_base_unlocked(gc->ngpio); + if (base < 0) { + ret = base; + base = 0; + goto err_free_label; + } - ret = gpiodev_add_to_list_unlocked(gdev); - if (ret) { - spin_unlock_irqrestore(&gpio_lock, flags); - chip_err(gc, "GPIO integer space overlap, cannot add chip\n"); - goto err_free_label; - } + /* + * TODO: it should not be necessary to reflect the + * assigned base outside of the GPIO subsystem. Go over + * drivers and see if anyone makes use of this, else + * drop this and assign a poison instead. + */ + gc->base = base; + } else { + dev_warn(&gdev->dev, + "Static allocation of GPIO base is deprecated, use dynamic allocation.\n"); + } - for (i = 0; i < gc->ngpio; i++) - gdev->descs[i].gdev = gdev; + gdev->base = base; - spin_unlock_irqrestore(&gpio_lock, flags); + ret = gpiodev_add_to_list_unlocked(gdev); + if (ret) { + chip_err(gc, "GPIO integer space overlap, cannot add chip\n"); + goto err_free_label; + } + } - BLOCKING_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier); + rwlock_init(&gdev->line_state_lock); + RAW_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier); BLOCKING_INIT_NOTIFIER_HEAD(&gdev->device_notifier); - init_rwsem(&gdev->sem); + + ret = init_srcu_struct(&gdev->srcu); + if (ret) + goto err_remove_from_list; + + ret = init_srcu_struct(&gdev->desc_srcu); + if (ret) + goto err_cleanup_gdev_srcu; #ifdef CONFIG_PINCTRL INIT_LIST_HEAD(&gdev->pin_ranges); #endif - if (gc->names) { - ret = gpiochip_set_desc_names(gc); - if (ret) - goto err_remove_from_list; - } + if (gc->names) + gpiochip_set_desc_names(gc); + ret = gpiochip_set_names(gc); if (ret) - goto err_remove_from_list; + goto err_cleanup_desc_srcu; ret = gpiochip_init_valid_mask(gc); if (ret) - goto err_remove_from_list; + goto err_cleanup_desc_srcu; - ret = of_gpiochip_add(gc); - if (ret) - goto err_free_gpiochip_mask; + for (desc_index = 0; desc_index < gc->ngpio; desc_index++) { + struct gpio_desc *desc = &gdev->descs[desc_index]; - for (i = 0; i < gc->ngpio; i++) { - struct gpio_desc *desc = &gdev->descs[i]; + desc->gdev = gdev; - if (gc->get_direction && gpiochip_line_is_valid(gc, i)) { - assign_bit(FLAG_IS_OUT, - &desc->flags, !gc->get_direction(gc, i)); - } else { + /* + * We would typically want to use gpiochip_get_direction() here + * but we must not check the return value and bail-out as pin + * controllers can have pins configured to alternate functions + * and return -EINVAL. Also: there's no need to take the SRCU + * lock here. + */ + if (gc->get_direction && gpiochip_line_is_valid(gc, desc_index)) + assign_bit(FLAG_IS_OUT, &desc->flags, + !gc->get_direction(gc, desc_index)); + else assign_bit(FLAG_IS_OUT, &desc->flags, !gc->direction_input); - } } + ret = of_gpiochip_add(gc); + if (ret) + goto err_free_valid_mask; + ret = gpiochip_add_pin_ranges(gc); if (ret) goto err_remove_of_chip; @@ -968,11 +1181,11 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, ret = gpiochip_irqchip_init_valid_mask(gc); if (ret) - goto err_remove_acpi_chip; + goto err_free_hogs; ret = gpiochip_irqchip_init_hw(gc); if (ret) - goto err_remove_acpi_chip; + goto err_remove_irqchip_mask; ret = gpiochip_add_irqchip(gc, lock_key, request_key); if (ret) @@ -997,23 +1210,27 @@ err_remove_irqchip: gpiochip_irqchip_remove(gc); err_remove_irqchip_mask: gpiochip_irqchip_free_valid_mask(gc); -err_remove_acpi_chip: +err_free_hogs: + gpiochip_free_hogs(gc); acpi_gpiochip_remove(gc); + gpiochip_remove_pin_ranges(gc); err_remove_of_chip: - gpiochip_free_hogs(gc); of_gpiochip_remove(gc); -err_free_gpiochip_mask: - gpiochip_remove_pin_ranges(gc); +err_free_valid_mask: gpiochip_free_valid_mask(gc); +err_cleanup_desc_srcu: + cleanup_srcu_struct(&gdev->desc_srcu); +err_cleanup_gdev_srcu: + cleanup_srcu_struct(&gdev->srcu); +err_remove_from_list: + scoped_guard(mutex, &gpio_devices_lock) + list_del_rcu(&gdev->list); + synchronize_srcu(&gpio_devices_srcu); if (gdev->dev.release) { /* release() has been registered by gpiochip_setup_dev() */ gpio_device_put(gdev); goto err_print_message; } -err_remove_from_list: - spin_lock_irqsave(&gpio_lock, flags); - list_del(&gdev->list); - spin_unlock_irqrestore(&gpio_lock, flags); err_free_label: kfree_const(gdev->label); err_free_descs: @@ -1044,16 +1261,19 @@ EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key); void gpiochip_remove(struct gpio_chip *gc) { struct gpio_device *gdev = gc->gpiodev; - unsigned long flags; - unsigned int i; - - down_write(&gdev->sem); /* FIXME: should the legacy sysfs handling be moved to gpio_device? */ gpiochip_sysfs_unregister(gdev); gpiochip_free_hogs(gc); + gpiochip_free_remaining_irqs(gc); + + scoped_guard(mutex, &gpio_devices_lock) + list_del_rcu(&gdev->list); + synchronize_srcu(&gpio_devices_srcu); + /* Numb the device, cancelling all outstanding operations */ - gdev->chip = NULL; + rcu_assign_pointer(gdev->chip, NULL); + synchronize_srcu(&gdev->srcu); gpiochip_irqchip_remove(gc); acpi_gpiochip_remove(gc); of_gpiochip_remove(gc); @@ -1065,20 +1285,6 @@ void gpiochip_remove(struct gpio_chip *gc) */ gpiochip_set_data(gc, NULL); - spin_lock_irqsave(&gpio_lock, flags); - for (i = 0; i < gdev->ngpio; i++) { - if (test_bit(FLAG_REQUESTED, &gdev->descs[i].flags)) - break; - } - spin_unlock_irqrestore(&gpio_lock, flags); - - if (i != gdev->ngpio) - dev_crit(&gdev->dev, - "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n"); - - scoped_guard(spinlock_irqsave, &gpio_lock) - list_del(&gdev->list); - /* * The gpiochip side puts its use of the device to rest here: * if there are no userspace clients, the chardev and device will @@ -1086,7 +1292,6 @@ void gpiochip_remove(struct gpio_chip *gc) * gone. */ gcdev_unregister(gdev); - up_write(&gdev->sem); gpio_device_put(gdev); } EXPORT_SYMBOL_GPL(gpiochip_remove); @@ -1112,23 +1317,27 @@ EXPORT_SYMBOL_GPL(gpiochip_remove); * If the function returns non-NULL, the returned reference must be freed by * the caller using gpio_device_put(). */ -struct gpio_device *gpio_device_find(void *data, +struct gpio_device *gpio_device_find(const void *data, int (*match)(struct gpio_chip *gc, - void *data)) + const void *data)) { struct gpio_device *gdev; + struct gpio_chip *gc; - /* - * Not yet but in the future the spinlock below will become a mutex. - * Annotate this function before anyone tries to use it in interrupt - * context like it happened with gpiochip_find(). - */ might_sleep(); - guard(spinlock_irqsave)(&gpio_lock); + guard(srcu)(&gpio_devices_srcu); - list_for_each_entry(gdev, &gpio_devices, list) { - if (gdev->chip && match(gdev->chip, data)) + list_for_each_entry_srcu(gdev, &gpio_devices, list, + srcu_read_lock_held(&gpio_devices_srcu)) { + if (!device_is_registered(&gdev->dev)) + continue; + + guard(srcu)(&gdev->srcu); + + gc = srcu_dereference(gdev->chip, &gdev->srcu); + + if (gc && match(gc, data)) return gpio_device_get(gdev); } @@ -1136,7 +1345,7 @@ struct gpio_device *gpio_device_find(void *data, } EXPORT_SYMBOL_GPL(gpio_device_find); -static int gpio_chip_match_by_label(struct gpio_chip *gc, void *label) +static int gpio_chip_match_by_label(struct gpio_chip *gc, const void *label) { return gc->label && !strcmp(gc->label, label); } @@ -1156,7 +1365,7 @@ struct gpio_device *gpio_device_find_by_label(const char *label) } EXPORT_SYMBOL_GPL(gpio_device_find_by_label); -static int gpio_chip_match_by_fwnode(struct gpio_chip *gc, void *fwnode) +static int gpio_chip_match_by_fwnode(struct gpio_chip *gc, const void *fwnode) { return device_match_fwnode(&gc->gpiodev->dev, fwnode); } @@ -1254,8 +1463,8 @@ static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc) gpiochip_free_mask(&gc->irq.valid_mask); } -bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc, - unsigned int offset) +static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc, + unsigned int offset) { if (!gpiochip_line_is_valid(gc, offset)) return false; @@ -1264,7 +1473,6 @@ bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc, return true; return test_bit(offset, gc->irq.valid_mask); } -EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid); #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY @@ -1344,9 +1552,8 @@ static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d, unsigned int *type) { /* We support standard DT translation */ - if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) { - return irq_domain_translate_twocell(d, fwspec, hwirq, type); - } + if (is_of_node(fwspec->fwnode)) + return irq_domain_translate_twothreecell(d, fwspec, hwirq, type); /* This is for board files and others not using DT */ if (is_fwnode_irqchip(fwspec->fwnode)) { @@ -1439,6 +1646,46 @@ static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc, return offset; } +/** + * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ + * @domain: The IRQ domain used by this IRQ chip + * @data: Outermost irq_data associated with the IRQ + * @reserve: If set, only reserve an interrupt vector instead of assigning one + * + * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be + * used as the activate function for the &struct irq_domain_ops. The host_data + * for the IRQ domain must be the &struct gpio_chip. + * + * Returns: + * 0 on success, or negative errno on failure. + */ +static int gpiochip_irq_domain_activate(struct irq_domain *domain, + struct irq_data *data, bool reserve) +{ + struct gpio_chip *gc = domain->host_data; + unsigned int hwirq = irqd_to_hwirq(data); + + return gpiochip_lock_as_irq(gc, hwirq); +} + +/** + * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ + * @domain: The IRQ domain used by this IRQ chip + * @data: Outermost irq_data associated with the IRQ + * + * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to + * be used as the deactivate function for the &struct irq_domain_ops. The + * host_data for the IRQ domain must be the &struct gpio_chip. + */ +static void gpiochip_irq_domain_deactivate(struct irq_domain *domain, + struct irq_data *data) +{ + struct gpio_chip *gc = domain->host_data; + unsigned int hwirq = irqd_to_hwirq(data); + + return gpiochip_unlock_as_irq(gc, hwirq); +} + static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops) { ops->activate = gpiochip_irq_domain_activate; @@ -1555,8 +1802,12 @@ static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc) * This function will set up the mapping for a certain IRQ line on a * gpiochip by assigning the gpiochip as chip data, and using the irqchip * stored inside the gpiochip. + * + * Returns: + * 0 on success, or negative errno on failure. */ -int gpiochip_irq_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hwirq) +static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq, + irq_hw_number_t hwirq) { struct gpio_chip *gc = d->host_data; int ret = 0; @@ -1593,9 +1844,8 @@ int gpiochip_irq_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hwi return 0; } -EXPORT_SYMBOL_GPL(gpiochip_irq_map); -void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq) +static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq) { struct gpio_chip *gc = d->host_data; @@ -1604,13 +1854,27 @@ void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq) irq_set_chip_and_handler(irq, NULL, NULL); irq_set_chip_data(irq, NULL); } -EXPORT_SYMBOL_GPL(gpiochip_irq_unmap); + +static int gpiochip_irq_select(struct irq_domain *d, struct irq_fwspec *fwspec, + enum irq_domain_bus_token bus_token) +{ + struct fwnode_handle *fwnode = fwspec->fwnode; + struct gpio_chip *gc = d->host_data; + unsigned int index = fwspec->param[0]; + + if (fwspec->param_count == 3 && is_of_node(fwnode)) + return of_gpiochip_instance_match(gc, index); + + /* Fallback for twocells */ + return (fwnode && (d->fwnode == fwnode) && (d->bus_token == bus_token)); +} static const struct irq_domain_ops gpiochip_domain_ops = { .map = gpiochip_irq_map, .unmap = gpiochip_irq_unmap, + .select = gpiochip_irq_select, /* Virtually all GPIO irqchips are twocell:ed */ - .xlate = irq_domain_xlate_twocell, + .xlate = irq_domain_xlate_twothreecell, }; static struct irq_domain *gpiochip_simple_create_domain(struct gpio_chip *gc) @@ -1626,55 +1890,10 @@ static struct irq_domain *gpiochip_simple_create_domain(struct gpio_chip *gc) return domain; } -/* - * TODO: move these activate/deactivate in under the hierarchicial - * irqchip implementation as static once SPMI and SSBI (all external - * users) are phased over. - */ -/** - * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ - * @domain: The IRQ domain used by this IRQ chip - * @data: Outermost irq_data associated with the IRQ - * @reserve: If set, only reserve an interrupt vector instead of assigning one - * - * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be - * used as the activate function for the &struct irq_domain_ops. The host_data - * for the IRQ domain must be the &struct gpio_chip. - */ -int gpiochip_irq_domain_activate(struct irq_domain *domain, - struct irq_data *data, bool reserve) -{ - struct gpio_chip *gc = domain->host_data; - unsigned int hwirq = irqd_to_hwirq(data); - - return gpiochip_lock_as_irq(gc, hwirq); -} -EXPORT_SYMBOL_GPL(gpiochip_irq_domain_activate); - -/** - * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ - * @domain: The IRQ domain used by this IRQ chip - * @data: Outermost irq_data associated with the IRQ - * - * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to - * be used as the deactivate function for the &struct irq_domain_ops. The - * host_data for the IRQ domain must be the &struct gpio_chip. - */ -void gpiochip_irq_domain_deactivate(struct irq_domain *domain, - struct irq_data *data) -{ - struct gpio_chip *gc = domain->host_data; - unsigned int hwirq = irqd_to_hwirq(data); - - return gpiochip_unlock_as_irq(gc, hwirq); -} -EXPORT_SYMBOL_GPL(gpiochip_irq_domain_deactivate); - static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset) { struct irq_domain *domain = gc->irq.domain; -#ifdef CONFIG_GPIOLIB_IRQCHIP /* * Avoid race condition with other code, which tries to lookup * an IRQ before the irqchip has been properly registered, @@ -1682,7 +1901,6 @@ static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset) */ if (!gc->irq.initialized) return -EPROBE_DEFER; -#endif if (!gpiochip_irqchip_irq_valid(gc, offset)) return -ENXIO; @@ -1834,6 +2052,9 @@ static int gpiochip_irqchip_add_allocated_domain(struct gpio_chip *gc, * @gc: the GPIO chip to add the IRQ chip to * @lock_key: lockdep class for IRQ lock * @request_key: lockdep class for IRQ request + * + * Returns: + * 0 on success, or a negative errno on failure. */ static int gpiochip_add_irqchip(struct gpio_chip *gc, struct lock_class_key *lock_key, @@ -1969,6 +2190,9 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gc) * @domain: the irqdomain to add to the gpiochip * * This function adds an IRQ domain to the gpiochip. + * + * Returns: + * 0 on success, or negative errno on failure. */ int gpiochip_irqchip_add_domain(struct gpio_chip *gc, struct irq_domain *domain) @@ -2005,6 +2229,9 @@ static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc) * gpiochip_generic_request() - request the gpio function for a pin * @gc: the gpiochip owning the GPIO * @offset: the offset of the GPIO to request for GPIO function + * + * Returns: + * 0 on success, or negative errno on failure. */ int gpiochip_generic_request(struct gpio_chip *gc, unsigned int offset) { @@ -2038,10 +2265,18 @@ EXPORT_SYMBOL_GPL(gpiochip_generic_free); * @gc: the gpiochip owning the GPIO * @offset: the offset of the GPIO to apply the configuration * @config: the configuration to be applied + * + * Returns: + * 0 on success, or negative errno on failure. */ int gpiochip_generic_config(struct gpio_chip *gc, unsigned int offset, unsigned long config) { +#ifdef CONFIG_PINCTRL + if (list_empty(&gc->gpiodev->pin_ranges)) + return -ENOTSUPP; +#endif + return pinctrl_gpio_set_config(gc, offset, config); } EXPORT_SYMBOL_GPL(gpiochip_generic_config); @@ -2059,6 +2294,9 @@ EXPORT_SYMBOL_GPL(gpiochip_generic_config); * pinctrl driver is DEPRECATED. Please see Section 2.1 of * Documentation/devicetree/bindings/gpio/gpio.txt on how to * bind pinctrl and gpio drivers via the "gpio-ranges" property. + * + * Returns: + * 0 on success, or negative errno on failure. */ int gpiochip_add_pingroup_range(struct gpio_chip *gc, struct pinctrl_dev *pctldev, @@ -2110,13 +2348,13 @@ EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range); * @npins: the number of pins from the offset of each pin space (GPIO and * pin controller) to accumulate in this range * - * Returns: - * 0 on success, or a negative error-code on failure. - * * Calling this function directly from a DeviceTree-supported * pinctrl driver is DEPRECATED. Please see Section 2.1 of * Documentation/devicetree/bindings/gpio/gpio.txt on how to * bind pinctrl and gpio drivers via the "gpio-ranges" property. + * + * Returns: + * 0 on success, or a negative errno on failure. */ int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name, unsigned int gpio_offset, unsigned int pin_offset, @@ -2184,99 +2422,46 @@ EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges); */ static int gpiod_request_commit(struct gpio_desc *desc, const char *label) { - struct gpio_chip *gc = desc->gdev->chip; - unsigned long flags; unsigned int offset; int ret; - if (label) { - label = kstrdup_const(label, GFP_KERNEL); - if (!label) - return -ENOMEM; - } + CLASS(gpio_chip_guard, guard)(desc); + if (!guard.gc) + return -ENODEV; + + if (test_and_set_bit(FLAG_REQUESTED, &desc->flags)) + return -EBUSY; - spin_lock_irqsave(&gpio_lock, flags); + offset = gpio_chip_hwgpio(desc); + if (!gpiochip_line_is_valid(guard.gc, offset)) + return -EINVAL; /* NOTE: gpio_request() can be called in early boot, * before IRQs are enabled, for non-sleeping (SOC) GPIOs. */ - if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) { - desc_set_label(desc, label ? : "?"); - } else { - ret = -EBUSY; - goto out_free_unlock; + if (guard.gc->request) { + ret = guard.gc->request(guard.gc, offset); + if (ret > 0) + ret = -EBADE; + if (ret) + goto out_clear_bit; } - if (gc->request) { - /* gc->request may sleep */ - spin_unlock_irqrestore(&gpio_lock, flags); - offset = gpio_chip_hwgpio(desc); - if (gpiochip_line_is_valid(gc, offset)) - ret = gc->request(gc, offset); - else - ret = -EINVAL; - spin_lock_irqsave(&gpio_lock, flags); - - if (ret) { - desc_set_label(desc, NULL); - clear_bit(FLAG_REQUESTED, &desc->flags); - goto out_free_unlock; - } - } - if (gc->get_direction) { - /* gc->get_direction may sleep */ - spin_unlock_irqrestore(&gpio_lock, flags); + if (guard.gc->get_direction) gpiod_get_direction(desc); - spin_lock_irqsave(&gpio_lock, flags); - } - spin_unlock_irqrestore(&gpio_lock, flags); + + ret = desc_set_label(desc, label ? : "?"); + if (ret) + goto out_clear_bit; + return 0; -out_free_unlock: - spin_unlock_irqrestore(&gpio_lock, flags); - kfree_const(label); +out_clear_bit: + clear_bit(FLAG_REQUESTED, &desc->flags); return ret; } -/* - * This descriptor validation needs to be inserted verbatim into each - * function taking a descriptor, so we need to use a preprocessor - * macro to avoid endless duplication. If the desc is NULL it is an - * optional GPIO and calls should just bail out. - */ -static int validate_desc(const struct gpio_desc *desc, const char *func) -{ - if (!desc) - return 0; - if (IS_ERR(desc)) { - pr_warn("%s: invalid GPIO (errorpointer)\n", func); - return PTR_ERR(desc); - } - if (!desc->gdev) { - pr_warn("%s: invalid GPIO (no device)\n", func); - return -EINVAL; - } - if (!desc->gdev->chip) { - dev_warn(&desc->gdev->dev, - "%s: backing chip is gone\n", func); - return 0; - } - return 1; -} - -#define VALIDATE_DESC(desc) do { \ - int __valid = validate_desc(desc, __func__); \ - if (__valid <= 0) \ - return __valid; \ - } while (0) - -#define VALIDATE_DESC_VOID(desc) do { \ - int __valid = validate_desc(desc, __func__); \ - if (__valid <= 0) \ - return; \ - } while (0) - int gpiod_request(struct gpio_desc *desc, const char *label) { int ret = -EPROBE_DEFER; @@ -2297,60 +2482,47 @@ int gpiod_request(struct gpio_desc *desc, const char *label) return ret; } -static bool gpiod_free_commit(struct gpio_desc *desc) +static void gpiod_free_commit(struct gpio_desc *desc) { - struct gpio_chip *gc; unsigned long flags; - bool ret = false; might_sleep(); - spin_lock_irqsave(&gpio_lock, flags); + CLASS(gpio_chip_guard, guard)(desc); - gc = desc->gdev->chip; - if (gc && test_bit(FLAG_REQUESTED, &desc->flags)) { - if (gc->free) { - spin_unlock_irqrestore(&gpio_lock, flags); - might_sleep_if(gc->can_sleep); - gc->free(gc, gpio_chip_hwgpio(desc)); - spin_lock_irqsave(&gpio_lock, flags); - } - kfree_const(desc->label); - desc_set_label(desc, NULL); - clear_bit(FLAG_ACTIVE_LOW, &desc->flags); - clear_bit(FLAG_REQUESTED, &desc->flags); - clear_bit(FLAG_OPEN_DRAIN, &desc->flags); - clear_bit(FLAG_OPEN_SOURCE, &desc->flags); - clear_bit(FLAG_PULL_UP, &desc->flags); - clear_bit(FLAG_PULL_DOWN, &desc->flags); - clear_bit(FLAG_BIAS_DISABLE, &desc->flags); - clear_bit(FLAG_EDGE_RISING, &desc->flags); - clear_bit(FLAG_EDGE_FALLING, &desc->flags); - clear_bit(FLAG_IS_HOGGED, &desc->flags); + flags = READ_ONCE(desc->flags); + + if (guard.gc && test_bit(FLAG_REQUESTED, &flags)) { + if (guard.gc->free) + guard.gc->free(guard.gc, gpio_chip_hwgpio(desc)); + + clear_bit(FLAG_ACTIVE_LOW, &flags); + clear_bit(FLAG_REQUESTED, &flags); + clear_bit(FLAG_OPEN_DRAIN, &flags); + clear_bit(FLAG_OPEN_SOURCE, &flags); + clear_bit(FLAG_PULL_UP, &flags); + clear_bit(FLAG_PULL_DOWN, &flags); + clear_bit(FLAG_BIAS_DISABLE, &flags); + clear_bit(FLAG_EDGE_RISING, &flags); + clear_bit(FLAG_EDGE_FALLING, &flags); + clear_bit(FLAG_IS_HOGGED, &flags); #ifdef CONFIG_OF_DYNAMIC - desc->hog = NULL; + WRITE_ONCE(desc->hog, NULL); #endif - ret = true; + desc_set_label(desc, NULL); + WRITE_ONCE(desc->flags, flags); +#ifdef CONFIG_GPIO_CDEV + WRITE_ONCE(desc->debounce_period_us, 0); +#endif + gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_RELEASED); } - - spin_unlock_irqrestore(&gpio_lock, flags); - gpiod_line_state_notify(desc, GPIOLINE_CHANGED_RELEASED); - - return ret; } void gpiod_free(struct gpio_desc *desc) { - /* - * We must not use VALIDATE_DESC_VOID() as the underlying gdev->chip - * may already be NULL but we still want to put the references. - */ - if (!desc) - return; - - if (!gpiod_free_commit(desc)) - WARN_ON(1); + VALIDATE_DESC_VOID(desc); + gpiod_free_commit(desc); module_put(desc->gdev->owner); gpio_device_put(desc->gdev); } @@ -2376,20 +2548,12 @@ char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset) if (IS_ERR(desc)) return NULL; - guard(spinlock_irqsave)(&gpio_lock); - if (!test_bit(FLAG_REQUESTED, &desc->flags)) return NULL; - /* - * FIXME: Once we mark gpiod_direction_input/output() and - * gpiod_get_direction() with might_sleep(), we'll be able to protect - * the GPIO descriptors with mutex (while value setting operations will - * become lockless). - * - * Until this happens, this allocation needs to be atomic. - */ - label = kstrdup(desc->label, GFP_ATOMIC); + guard(srcu)(&desc->gdev->desc_srcu); + + label = kstrdup(gpiod_get_label(desc), GFP_KERNEL); if (!label) return ERR_PTR(-ENOMEM); @@ -2397,6 +2561,11 @@ char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset) } EXPORT_SYMBOL_GPL(gpiochip_dup_line_label); +static inline const char *function_name_or_default(const char *con_id) +{ + return con_id ?: "(default)"; +} + /** * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor * @gc: GPIO chip @@ -2425,10 +2594,11 @@ struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc, enum gpiod_flags dflags) { struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum); + const char *name = function_name_or_default(label); int ret; if (IS_ERR(desc)) { - chip_err(gc, "failed to get GPIO descriptor\n"); + chip_err(gc, "failed to get GPIO %s descriptor\n", name); return desc; } @@ -2438,11 +2608,13 @@ struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc, ret = gpiod_configure_flags(desc, label, lflags, dflags); if (ret) { - chip_err(gc, "setup of own GPIO %s failed\n", label); gpiod_free_commit(desc); + chip_err(gc, "setup of own GPIO %s failed\n", name); return ERR_PTR(ret); } + gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_REQUESTED); + return desc; } EXPORT_SYMBOL_GPL(gpiochip_request_own_desc); @@ -2471,24 +2643,41 @@ EXPORT_SYMBOL_GPL(gpiochip_free_own_desc); * rely on gpio_request() having been called beforehand. */ -static int gpio_do_set_config(struct gpio_chip *gc, unsigned int offset, - unsigned long config) +int gpio_do_set_config(struct gpio_desc *desc, unsigned long config) { - if (!gc->set_config) + int ret; + + CLASS(gpio_chip_guard, guard)(desc); + if (!guard.gc) + return -ENODEV; + + if (!guard.gc->set_config) return -ENOTSUPP; - return gc->set_config(gc, offset, config); + ret = guard.gc->set_config(guard.gc, gpio_chip_hwgpio(desc), config); + if (ret > 0) + ret = -EBADE; + +#ifdef CONFIG_GPIO_CDEV + /* + * Special case - if we're setting debounce period, we need to store + * it in the descriptor in case user-space wants to know it. + */ + if (!ret && pinconf_to_config_param(config) == PIN_CONFIG_INPUT_DEBOUNCE) + WRITE_ONCE(desc->debounce_period_us, + pinconf_to_config_argument(config)); +#endif + return ret; } static int gpio_set_config_with_argument(struct gpio_desc *desc, enum pin_config_param mode, u32 argument) { - struct gpio_chip *gc = desc->gdev->chip; unsigned long config; config = pinconf_to_config_packed(mode, argument); - return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config); + return gpio_do_set_config(desc, config); } static int gpio_set_config_with_argument_optional(struct gpio_desc *desc, @@ -2522,13 +2711,16 @@ static int gpio_set_config(struct gpio_desc *desc, enum pin_config_param mode) static int gpio_set_bias(struct gpio_desc *desc) { enum pin_config_param bias; + unsigned long flags; unsigned int arg; - if (test_bit(FLAG_BIAS_DISABLE, &desc->flags)) + flags = READ_ONCE(desc->flags); + + if (test_bit(FLAG_BIAS_DISABLE, &flags)) bias = PIN_CONFIG_BIAS_DISABLE; - else if (test_bit(FLAG_PULL_UP, &desc->flags)) + else if (test_bit(FLAG_PULL_UP, &flags)) bias = PIN_CONFIG_BIAS_PULL_UP; - else if (test_bit(FLAG_PULL_DOWN, &desc->flags)) + else if (test_bit(FLAG_PULL_DOWN, &flags)) bias = PIN_CONFIG_BIAS_PULL_DOWN; else return 0; @@ -2555,13 +2747,53 @@ static int gpio_set_bias(struct gpio_desc *desc) * The function calls the certain GPIO driver to set debounce timeout * in the hardware. * - * Returns 0 on success, or negative error code otherwise. + * Returns: + * 0 on success, or negative errno on failure. */ int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce) { - return gpio_set_config_with_argument_optional(desc, - PIN_CONFIG_INPUT_DEBOUNCE, - debounce); + int ret; + + ret = gpio_set_config_with_argument_optional(desc, + PIN_CONFIG_INPUT_DEBOUNCE, + debounce); + if (!ret) + gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG); + + return ret; +} + +static int gpiochip_direction_input(struct gpio_chip *gc, unsigned int offset) +{ + int ret; + + lockdep_assert_held(&gc->gpiodev->srcu); + + if (WARN_ON(!gc->direction_input)) + return -EOPNOTSUPP; + + ret = gc->direction_input(gc, offset); + if (ret > 0) + ret = -EBADE; + + return ret; +} + +static int gpiochip_direction_output(struct gpio_chip *gc, unsigned int offset, + int value) +{ + int ret; + + lockdep_assert_held(&gc->gpiodev->srcu); + + if (WARN_ON(!gc->direction_output)) + return -EOPNOTSUPP; + + ret = gc->direction_output(gc, offset, value); + if (ret > 0) + ret = -EBADE; + + return ret; } /** @@ -2571,22 +2803,37 @@ int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce) * Set the direction of the passed GPIO to input, such as gpiod_get_value() can * be called safely on it. * - * Return 0 in case of success, else an error code. + * Returns: + * 0 on success, or negative errno on failure. */ int gpiod_direction_input(struct gpio_desc *desc) { - struct gpio_chip *gc; - int ret = 0; + int ret; VALIDATE_DESC(desc); - gc = desc->gdev->chip; + + ret = gpiod_direction_input_nonotify(desc); + if (ret == 0) + gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG); + + return ret; +} +EXPORT_SYMBOL_GPL(gpiod_direction_input); + +int gpiod_direction_input_nonotify(struct gpio_desc *desc) +{ + int ret = 0, dir; + + CLASS(gpio_chip_guard, guard)(desc); + if (!guard.gc) + return -ENODEV; /* * It is legal to have no .get() and .direction_input() specified if * the chip is output-only, but you can't specify .direction_input() * and not support the .get() operation, that doesn't make sense. */ - if (!gc->get && gc->direction_input) { + if (!guard.gc->get && guard.gc->direction_input) { gpiod_warn(desc, "%s: missing get() but have direction_input()\n", __func__); @@ -2599,14 +2846,20 @@ int gpiod_direction_input(struct gpio_desc *desc) * direction (if .get_direction() is supported) else we silently * assume we are in input mode after this. */ - if (gc->direction_input) { - ret = gc->direction_input(gc, gpio_chip_hwgpio(desc)); - } else if (gc->get_direction && - (gc->get_direction(gc, gpio_chip_hwgpio(desc)) != 1)) { - gpiod_warn(desc, - "%s: missing direction_input() operation and line is output\n", - __func__); - return -EIO; + if (guard.gc->direction_input) { + ret = gpiochip_direction_input(guard.gc, + gpio_chip_hwgpio(desc)); + } else if (guard.gc->get_direction) { + dir = gpiochip_get_direction(guard.gc, gpio_chip_hwgpio(desc)); + if (dir < 0) + return dir; + + if (dir != GPIO_LINE_DIRECTION_IN) { + gpiod_warn(desc, + "%s: missing direction_input() operation and line is output\n", + __func__); + return -EIO; + } } if (ret == 0) { clear_bit(FLAG_IS_OUT, &desc->flags); @@ -2617,42 +2870,73 @@ int gpiod_direction_input(struct gpio_desc *desc) return ret; } -EXPORT_SYMBOL_GPL(gpiod_direction_input); + +static int gpiochip_set(struct gpio_chip *gc, unsigned int offset, int value) +{ + int ret; + + lockdep_assert_held(&gc->gpiodev->srcu); + + if (WARN_ON(unlikely(!gc->set && !gc->set_rv))) + return -EOPNOTSUPP; + + if (gc->set_rv) { + ret = gc->set_rv(gc, offset, value); + if (ret > 0) + ret = -EBADE; + + return ret; + } + + gc->set(gc, offset, value); + return 0; +} static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value) { - struct gpio_chip *gc = desc->gdev->chip; - int val = !!value; - int ret = 0; + int val = !!value, ret = 0, dir; + + CLASS(gpio_chip_guard, guard)(desc); + if (!guard.gc) + return -ENODEV; /* * It's OK not to specify .direction_output() if the gpiochip is * output-only, but if there is then not even a .set() operation it * is pretty tricky to drive the output line. */ - if (!gc->set && !gc->direction_output) { + if (!guard.gc->set && !guard.gc->set_rv && !guard.gc->direction_output) { gpiod_warn(desc, "%s: missing set() and direction_output() operations\n", __func__); return -EIO; } - if (gc->direction_output) { - ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val); + if (guard.gc->direction_output) { + ret = gpiochip_direction_output(guard.gc, + gpio_chip_hwgpio(desc), val); } else { /* Check that we are in output mode if we can */ - if (gc->get_direction && - gc->get_direction(gc, gpio_chip_hwgpio(desc))) { - gpiod_warn(desc, - "%s: missing direction_output() operation\n", - __func__); - return -EIO; + if (guard.gc->get_direction) { + dir = gpiochip_get_direction(guard.gc, + gpio_chip_hwgpio(desc)); + if (dir < 0) + return dir; + + if (dir != GPIO_LINE_DIRECTION_OUT) { + gpiod_warn(desc, + "%s: missing direction_output() operation\n", + __func__); + return -EIO; + } } /* * If we can't actively set the direction, we are some * output-only chip, so just drive the output as desired. */ - gc->set(gc, gpio_chip_hwgpio(desc), val); + ret = gpiochip_set(guard.gc, gpio_chip_hwgpio(desc), val); + if (ret) + return ret; } if (!ret) @@ -2671,12 +2955,20 @@ static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value) * be called safely on it. The initial value of the output must be specified * as raw value on the physical line without regard for the ACTIVE_LOW status. * - * Return 0 in case of success, else an error code. + * Returns: + * 0 on success, or negative errno on failure. */ int gpiod_direction_output_raw(struct gpio_desc *desc, int value) { + int ret; + VALIDATE_DESC(desc); - return gpiod_direction_output_raw_commit(desc, value); + + ret = gpiod_direction_output_raw_commit(desc, value); + if (ret == 0) + gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG); + + return ret; } EXPORT_SYMBOL_GPL(gpiod_direction_output_raw); @@ -2690,46 +2982,59 @@ EXPORT_SYMBOL_GPL(gpiod_direction_output_raw); * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into * account. * - * Return 0 in case of success, else an error code. + * Returns: + * 0 on success, or negative errno on failure. */ int gpiod_direction_output(struct gpio_desc *desc, int value) { int ret; VALIDATE_DESC(desc); - if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) + + ret = gpiod_direction_output_nonotify(desc, value); + if (ret == 0) + gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG); + + return ret; +} +EXPORT_SYMBOL_GPL(gpiod_direction_output); + +int gpiod_direction_output_nonotify(struct gpio_desc *desc, int value) +{ + unsigned long flags; + int ret; + + flags = READ_ONCE(desc->flags); + + if (test_bit(FLAG_ACTIVE_LOW, &flags)) value = !value; else value = !!value; /* GPIOs used for enabled IRQs shall not be set as output */ - if (test_bit(FLAG_USED_AS_IRQ, &desc->flags) && - test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) { + if (test_bit(FLAG_USED_AS_IRQ, &flags) && + test_bit(FLAG_IRQ_IS_ENABLED, &flags)) { gpiod_err(desc, "%s: tried to set a GPIO tied to an IRQ as output\n", __func__); return -EIO; } - if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) { + if (test_bit(FLAG_OPEN_DRAIN, &flags)) { /* First see if we can enable open drain in hardware */ ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_DRAIN); if (!ret) goto set_output_value; /* Emulate open drain by not actively driving the line high */ - if (value) { - ret = gpiod_direction_input(desc); + if (value) goto set_output_flag; - } - } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) { + } else if (test_bit(FLAG_OPEN_SOURCE, &flags)) { ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_SOURCE); if (!ret) goto set_output_value; /* Emulate open source by not actively driving the line low */ - if (!value) { - ret = gpiod_direction_input(desc); + if (!value) goto set_output_flag; - } } else { gpio_set_config(desc, PIN_CONFIG_DRIVE_PUSH_PULL); } @@ -2741,40 +3046,46 @@ set_output_value: return gpiod_direction_output_raw_commit(desc, value); set_output_flag: + ret = gpiod_direction_input_nonotify(desc); + if (ret) + return ret; /* * When emulating open-source or open-drain functionalities by not * actively driving the line (setting mode to input) we still need to * set the IS_OUT flag or otherwise we won't be able to set the line * value anymore. */ - if (ret == 0) - set_bit(FLAG_IS_OUT, &desc->flags); - return ret; + set_bit(FLAG_IS_OUT, &desc->flags); + return 0; } -EXPORT_SYMBOL_GPL(gpiod_direction_output); +#if IS_ENABLED(CONFIG_HTE) /** * gpiod_enable_hw_timestamp_ns - Enable hardware timestamp in nanoseconds. * * @desc: GPIO to enable. * @flags: Flags related to GPIO edge. * - * Return 0 in case of success, else negative error code. + * Returns: + * 0 on success, or negative errno on failure. */ int gpiod_enable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags) { - int ret = 0; - struct gpio_chip *gc; + int ret; VALIDATE_DESC(desc); - gc = desc->gdev->chip; - if (!gc->en_hw_timestamp) { + CLASS(gpio_chip_guard, guard)(desc); + if (!guard.gc) + return -ENODEV; + + if (!guard.gc->en_hw_timestamp) { gpiod_warn(desc, "%s: hw ts not supported\n", __func__); return -ENOTSUPP; } - ret = gc->en_hw_timestamp(gc, gpio_chip_hwgpio(desc), flags); + ret = guard.gc->en_hw_timestamp(guard.gc, + gpio_chip_hwgpio(desc), flags); if (ret) gpiod_warn(desc, "%s: hw ts request failed\n", __func__); @@ -2788,28 +3099,33 @@ EXPORT_SYMBOL_GPL(gpiod_enable_hw_timestamp_ns); * @desc: GPIO to disable. * @flags: Flags related to GPIO edge, same value as used during enable call. * - * Return 0 in case of success, else negative error code. + * Returns: + * 0 on success, or negative errno on failure. */ int gpiod_disable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags) { - int ret = 0; - struct gpio_chip *gc; + int ret; VALIDATE_DESC(desc); - gc = desc->gdev->chip; - if (!gc->dis_hw_timestamp) { + CLASS(gpio_chip_guard, guard)(desc); + if (!guard.gc) + return -ENODEV; + + if (!guard.gc->dis_hw_timestamp) { gpiod_warn(desc, "%s: hw ts not supported\n", __func__); return -ENOTSUPP; } - ret = gc->dis_hw_timestamp(gc, gpio_chip_hwgpio(desc), flags); + ret = guard.gc->dis_hw_timestamp(guard.gc, gpio_chip_hwgpio(desc), + flags); if (ret) gpiod_warn(desc, "%s: hw ts release failed\n", __func__); return ret; } EXPORT_SYMBOL_GPL(gpiod_disable_hw_timestamp_ns); +#endif /* CONFIG_HTE */ /** * gpiod_set_config - sets @config for a GPIO @@ -2822,12 +3138,30 @@ EXPORT_SYMBOL_GPL(gpiod_disable_hw_timestamp_ns); */ int gpiod_set_config(struct gpio_desc *desc, unsigned long config) { - struct gpio_chip *gc; + int ret; VALIDATE_DESC(desc); - gc = desc->gdev->chip; - return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config); + ret = gpio_do_set_config(desc, config); + if (!ret) { + /* These are the only options we notify the userspace about. */ + switch (pinconf_to_config_param(config)) { + case PIN_CONFIG_BIAS_DISABLE: + case PIN_CONFIG_BIAS_PULL_DOWN: + case PIN_CONFIG_BIAS_PULL_UP: + case PIN_CONFIG_DRIVE_OPEN_DRAIN: + case PIN_CONFIG_DRIVE_OPEN_SOURCE: + case PIN_CONFIG_DRIVE_PUSH_PULL: + case PIN_CONFIG_INPUT_DEBOUNCE: + gpiod_line_state_notify(desc, + GPIO_V2_LINE_CHANGED_CONFIG); + break; + default: + break; + } + } + + return ret; } EXPORT_SYMBOL_GPL(gpiod_set_config); @@ -2876,7 +3210,8 @@ int gpiod_set_transitory(struct gpio_desc *desc, bool transitory) * gpiod_is_active_low - test whether a GPIO is active-low or not * @desc: the gpio descriptor to test * - * Returns 1 if the GPIO is active-low, 0 otherwise. + * Returns: + * 1 if the GPIO is active-low, 0 otherwise. */ int gpiod_is_active_low(const struct gpio_desc *desc) { @@ -2893,12 +3228,27 @@ void gpiod_toggle_active_low(struct gpio_desc *desc) { VALIDATE_DESC_VOID(desc); change_bit(FLAG_ACTIVE_LOW, &desc->flags); + gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG); } EXPORT_SYMBOL_GPL(gpiod_toggle_active_low); +static int gpiochip_get(struct gpio_chip *gc, unsigned int offset) +{ + int ret; + + lockdep_assert_held(&gc->gpiodev->srcu); + + /* Make sure this is called after checking for gc->get(). */ + ret = gc->get(gc, offset); + if (ret > 1) + ret = -EBADE; + + return ret; +} + static int gpio_chip_get_value(struct gpio_chip *gc, const struct gpio_desc *desc) { - return gc->get ? gc->get(gc, gpio_chip_hwgpio(desc)) : -EIO; + return gc->get ? gpiochip_get(gc, gpio_chip_hwgpio(desc)) : -EIO; } /* I/O calls are only valid after configuration completed; the relevant @@ -2925,10 +3275,19 @@ static int gpio_chip_get_value(struct gpio_chip *gc, const struct gpio_desc *des static int gpiod_get_raw_value_commit(const struct gpio_desc *desc) { + struct gpio_device *gdev; struct gpio_chip *gc; int value; - gc = desc->gdev->chip; + /* FIXME Unable to use gpio_chip_guard due to const desc. */ + gdev = desc->gdev; + + guard(srcu)(&gdev->srcu); + + gc = srcu_dereference(gdev->chip, &gdev->srcu); + if (!gc) + return -ENODEV; + value = gpio_chip_get_value(gc, desc); value = value < 0 ? value : !!value; trace_gpio_value(desc_to_gpio(desc), 1, value); @@ -2938,13 +3297,21 @@ static int gpiod_get_raw_value_commit(const struct gpio_desc *desc) static int gpio_chip_get_multiple(struct gpio_chip *gc, unsigned long *mask, unsigned long *bits) { - if (gc->get_multiple) - return gc->get_multiple(gc, mask, bits); + int ret; + + lockdep_assert_held(&gc->gpiodev->srcu); + + if (gc->get_multiple) { + ret = gc->get_multiple(gc, mask, bits); + if (ret > 0) + return -EBADE; + } + if (gc->get) { int i, value; for_each_set_bit(i, mask, gc->ngpio) { - value = gc->get(gc, i); + value = gpiochip_get(gc, i); if (value < 0) return value; __assign_bit(i, bits, value); @@ -2954,12 +3321,21 @@ static int gpio_chip_get_multiple(struct gpio_chip *gc, return -EIO; } +/* The 'other' chip must be protected with its GPIO device's SRCU. */ +static bool gpio_device_chip_cmp(struct gpio_device *gdev, struct gpio_chip *gc) +{ + guard(srcu)(&gdev->srcu); + + return gc == srcu_dereference(gdev->chip, &gdev->srcu); +} + int gpiod_get_array_value_complex(bool raw, bool can_sleep, unsigned int array_size, struct gpio_desc **desc_array, struct gpio_array *array_info, unsigned long *value_bitmap) { + struct gpio_chip *gc; int ret, i = 0; /* @@ -2971,10 +3347,15 @@ int gpiod_get_array_value_complex(bool raw, bool can_sleep, array_size <= array_info->size && (void *)array_info == desc_array + array_info->size) { if (!can_sleep) - WARN_ON(array_info->chip->can_sleep); + WARN_ON(array_info->gdev->can_sleep); + + guard(srcu)(&array_info->gdev->srcu); + gc = srcu_dereference(array_info->gdev->chip, + &array_info->gdev->srcu); + if (!gc) + return -ENODEV; - ret = gpio_chip_get_multiple(array_info->chip, - array_info->get_mask, + ret = gpio_chip_get_multiple(gc, array_info->get_mask, value_bitmap); if (ret) return ret; @@ -2991,33 +3372,36 @@ int gpiod_get_array_value_complex(bool raw, bool can_sleep, } while (i < array_size) { - struct gpio_chip *gc = desc_array[i]->gdev->chip; DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO); DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO); unsigned long *mask, *bits; int first, j; - if (likely(gc->ngpio <= FASTPATH_NGPIO)) { + CLASS(gpio_chip_guard, guard)(desc_array[i]); + if (!guard.gc) + return -ENODEV; + + if (likely(guard.gc->ngpio <= FASTPATH_NGPIO)) { mask = fastpath_mask; bits = fastpath_bits; } else { gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC; - mask = bitmap_alloc(gc->ngpio, flags); + mask = bitmap_alloc(guard.gc->ngpio, flags); if (!mask) return -ENOMEM; - bits = bitmap_alloc(gc->ngpio, flags); + bits = bitmap_alloc(guard.gc->ngpio, flags); if (!bits) { bitmap_free(mask); return -ENOMEM; } } - bitmap_zero(mask, gc->ngpio); + bitmap_zero(mask, guard.gc->ngpio); if (!can_sleep) - WARN_ON(gc->can_sleep); + WARN_ON(guard.gc->can_sleep); /* collect all inputs belonging to the same chip */ first = i; @@ -3032,9 +3416,9 @@ int gpiod_get_array_value_complex(bool raw, bool can_sleep, i = find_next_zero_bit(array_info->get_mask, array_size, i); } while ((i < array_size) && - (desc_array[i]->gdev->chip == gc)); + gpio_device_chip_cmp(desc_array[i]->gdev, guard.gc)); - ret = gpio_chip_get_multiple(gc, mask, bits); + ret = gpio_chip_get_multiple(guard.gc, mask, bits); if (ret) { if (mask != fastpath_mask) bitmap_free(mask); @@ -3071,7 +3455,8 @@ int gpiod_get_array_value_complex(bool raw, bool can_sleep, * gpiod_get_raw_value() - return a gpio's raw value * @desc: gpio whose value will be returned * - * Return the GPIO's raw value, i.e. the value of the physical line disregarding + * Returns: + * The GPIO's raw value, i.e. the value of the physical line disregarding * its ACTIVE_LOW status, or negative errno on failure. * * This function can be called from contexts where we cannot sleep, and will @@ -3081,7 +3466,7 @@ int gpiod_get_raw_value(const struct gpio_desc *desc) { VALIDATE_DESC(desc); /* Should be using gpiod_get_raw_value_cansleep() */ - WARN_ON(desc->gdev->chip->can_sleep); + WARN_ON(desc->gdev->can_sleep); return gpiod_get_raw_value_commit(desc); } EXPORT_SYMBOL_GPL(gpiod_get_raw_value); @@ -3090,7 +3475,8 @@ EXPORT_SYMBOL_GPL(gpiod_get_raw_value); * gpiod_get_value() - return a gpio's value * @desc: gpio whose value will be returned * - * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into + * Returns: + * The GPIO's logical value, i.e. taking the ACTIVE_LOW status into * account, or negative errno on failure. * * This function can be called from contexts where we cannot sleep, and will @@ -3102,7 +3488,7 @@ int gpiod_get_value(const struct gpio_desc *desc) VALIDATE_DESC(desc); /* Should be using gpiod_get_value_cansleep() */ - WARN_ON(desc->gdev->chip->can_sleep); + WARN_ON(desc->gdev->can_sleep); value = gpiod_get_raw_value_commit(desc); if (value < 0) @@ -3123,11 +3509,13 @@ EXPORT_SYMBOL_GPL(gpiod_get_value); * @value_bitmap: bitmap to store the read values * * Read the raw values of the GPIOs, i.e. the values of the physical lines - * without regard for their ACTIVE_LOW status. Return 0 in case of success, - * else an error code. + * without regard for their ACTIVE_LOW status. * * This function can be called from contexts where we cannot sleep, * and it will complain if the GPIO chip functions potentially sleep. + * + * Returns: + * 0 on success, or negative errno on failure. */ int gpiod_get_raw_array_value(unsigned int array_size, struct gpio_desc **desc_array, @@ -3150,10 +3538,13 @@ EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value); * @value_bitmap: bitmap to store the read values * * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status - * into account. Return 0 in case of success, else an error code. + * into account. * * This function can be called from contexts where we cannot sleep, * and it will complain if the GPIO chip functions potentially sleep. + * + * Returns: + * 0 on success, or negative errno on failure. */ int gpiod_get_array_value(unsigned int array_size, struct gpio_desc **desc_array, @@ -3173,16 +3564,18 @@ EXPORT_SYMBOL_GPL(gpiod_get_array_value); * @desc: gpio descriptor whose state need to be set. * @value: Non-zero for setting it HIGH otherwise it will set to LOW. */ -static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value) +static int gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value) { - int ret = 0; - struct gpio_chip *gc = desc->gdev->chip; - int offset = gpio_chip_hwgpio(desc); + int ret = 0, offset = gpio_chip_hwgpio(desc); + + CLASS(gpio_chip_guard, guard)(desc); + if (!guard.gc) + return -ENODEV; if (value) { - ret = gc->direction_input(gc, offset); + ret = gpiochip_direction_input(guard.gc, offset); } else { - ret = gc->direction_output(gc, offset, 0); + ret = gpiochip_direction_output(guard.gc, offset, 0); if (!ret) set_bit(FLAG_IS_OUT, &desc->flags); } @@ -3191,6 +3584,8 @@ static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value) gpiod_err(desc, "%s: Error in set_value for open drain err %d\n", __func__, ret); + + return ret; } /* @@ -3198,33 +3593,41 @@ static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value) * @desc: gpio descriptor whose state need to be set. * @value: Non-zero for setting it HIGH otherwise it will set to LOW. */ -static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value) +static int gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value) { - int ret = 0; - struct gpio_chip *gc = desc->gdev->chip; - int offset = gpio_chip_hwgpio(desc); + int ret = 0, offset = gpio_chip_hwgpio(desc); + + CLASS(gpio_chip_guard, guard)(desc); + if (!guard.gc) + return -ENODEV; if (value) { - ret = gc->direction_output(gc, offset, 1); + ret = gpiochip_direction_output(guard.gc, offset, 1); if (!ret) set_bit(FLAG_IS_OUT, &desc->flags); } else { - ret = gc->direction_input(gc, offset); + ret = gpiochip_direction_input(guard.gc, offset); } trace_gpio_direction(desc_to_gpio(desc), !value, ret); if (ret < 0) gpiod_err(desc, "%s: Error in set_value for open source err %d\n", __func__, ret); + + return ret; } -static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value) +static int gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value) { - struct gpio_chip *gc; + if (unlikely(!test_bit(FLAG_IS_OUT, &desc->flags))) + return -EPERM; + + CLASS(gpio_chip_guard, guard)(desc); + if (!guard.gc) + return -ENODEV; - gc = desc->gdev->chip; trace_gpio_value(desc_to_gpio(desc), 0, value); - gc->set(gc, gpio_chip_hwgpio(desc), value); + return gpiochip_set(guard.gc, gpio_chip_hwgpio(desc), value); } /* @@ -3236,19 +3639,38 @@ static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value) * defines which outputs are to be changed * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word * defines the values the outputs specified by mask are to be set to + * + * Returns: 0 on success, negative error number on failure. */ -static void gpio_chip_set_multiple(struct gpio_chip *gc, - unsigned long *mask, unsigned long *bits) +static int gpiochip_set_multiple(struct gpio_chip *gc, + unsigned long *mask, unsigned long *bits) { + unsigned int i; + int ret; + + lockdep_assert_held(&gc->gpiodev->srcu); + + if (gc->set_multiple_rv) { + ret = gc->set_multiple_rv(gc, mask, bits); + if (ret > 0) + ret = -EBADE; + + return ret; + } + if (gc->set_multiple) { gc->set_multiple(gc, mask, bits); - } else { - unsigned int i; + return 0; + } - /* set outputs if the corresponding mask bit is set */ - for_each_set_bit(i, mask, gc->ngpio) - gc->set(gc, i, test_bit(i, bits)); + /* set outputs if the corresponding mask bit is set */ + for_each_set_bit(i, mask, gc->ngpio) { + ret = gpiochip_set(gc, i, test_bit(i, bits)); + if (ret) + break; } + + return ret; } int gpiod_set_array_value_complex(bool raw, bool can_sleep, @@ -3257,7 +3679,8 @@ int gpiod_set_array_value_complex(bool raw, bool can_sleep, struct gpio_array *array_info, unsigned long *value_bitmap) { - int i = 0; + struct gpio_chip *gc; + int i = 0, ret; /* * Validate array_info against desc_array and its size. @@ -3268,14 +3691,28 @@ int gpiod_set_array_value_complex(bool raw, bool can_sleep, array_size <= array_info->size && (void *)array_info == desc_array + array_info->size) { if (!can_sleep) - WARN_ON(array_info->chip->can_sleep); + WARN_ON(array_info->gdev->can_sleep); + + for (i = 0; i < array_size; i++) { + if (unlikely(!test_bit(FLAG_IS_OUT, + &desc_array[i]->flags))) + return -EPERM; + } + + guard(srcu)(&array_info->gdev->srcu); + gc = srcu_dereference(array_info->gdev->chip, + &array_info->gdev->srcu); + if (!gc) + return -ENODEV; if (!raw && !bitmap_empty(array_info->invert_mask, array_size)) bitmap_xor(value_bitmap, value_bitmap, array_info->invert_mask, array_size); - gpio_chip_set_multiple(array_info->chip, array_info->set_mask, - value_bitmap); + ret = gpiochip_set_multiple(gc, array_info->set_mask, + value_bitmap); + if (ret) + return ret; i = find_first_zero_bit(array_info->set_mask, array_size); if (i == array_size) @@ -3285,39 +3722,45 @@ int gpiod_set_array_value_complex(bool raw, bool can_sleep, } while (i < array_size) { - struct gpio_chip *gc = desc_array[i]->gdev->chip; DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO); DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO); unsigned long *mask, *bits; int count = 0; - if (likely(gc->ngpio <= FASTPATH_NGPIO)) { + CLASS(gpio_chip_guard, guard)(desc_array[i]); + if (!guard.gc) + return -ENODEV; + + if (likely(guard.gc->ngpio <= FASTPATH_NGPIO)) { mask = fastpath_mask; bits = fastpath_bits; } else { gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC; - mask = bitmap_alloc(gc->ngpio, flags); + mask = bitmap_alloc(guard.gc->ngpio, flags); if (!mask) return -ENOMEM; - bits = bitmap_alloc(gc->ngpio, flags); + bits = bitmap_alloc(guard.gc->ngpio, flags); if (!bits) { bitmap_free(mask); return -ENOMEM; } } - bitmap_zero(mask, gc->ngpio); + bitmap_zero(mask, guard.gc->ngpio); if (!can_sleep) - WARN_ON(gc->can_sleep); + WARN_ON(guard.gc->can_sleep); do { struct gpio_desc *desc = desc_array[i]; int hwgpio = gpio_chip_hwgpio(desc); int value = test_bit(i, value_bitmap); + if (unlikely(!test_bit(FLAG_IS_OUT, &desc->flags))) + return -EPERM; + /* * Pins applicable for fast input but not for * fast output processing may have been already @@ -3347,10 +3790,13 @@ int gpiod_set_array_value_complex(bool raw, bool can_sleep, i = find_next_zero_bit(array_info->set_mask, array_size, i); } while ((i < array_size) && - (desc_array[i]->gdev->chip == gc)); + gpio_device_chip_cmp(desc_array[i]->gdev, guard.gc)); /* push collected bits to outputs */ - if (count != 0) - gpio_chip_set_multiple(gc, mask, bits); + if (count != 0) { + ret = gpiochip_set_multiple(guard.gc, mask, bits); + if (ret) + return ret; + } if (mask != fastpath_mask) bitmap_free(mask); @@ -3370,13 +3816,16 @@ int gpiod_set_array_value_complex(bool raw, bool can_sleep, * * This function can be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. + * + * Returns: + * 0 on success, negative error number on failure. */ -void gpiod_set_raw_value(struct gpio_desc *desc, int value) +int gpiod_set_raw_value(struct gpio_desc *desc, int value) { - VALIDATE_DESC_VOID(desc); + VALIDATE_DESC(desc); /* Should be using gpiod_set_raw_value_cansleep() */ - WARN_ON(desc->gdev->chip->can_sleep); - gpiod_set_raw_value_commit(desc, value); + WARN_ON(desc->gdev->can_sleep); + return gpiod_set_raw_value_commit(desc, value); } EXPORT_SYMBOL_GPL(gpiod_set_raw_value); @@ -3388,17 +3837,21 @@ EXPORT_SYMBOL_GPL(gpiod_set_raw_value); * This sets the value of a GPIO line backing a descriptor, applying * different semantic quirks like active low and open drain/source * handling. + * + * Returns: + * 0 on success, negative error number on failure. */ -static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value) +static int gpiod_set_value_nocheck(struct gpio_desc *desc, int value) { if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) value = !value; + if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) - gpio_set_open_drain_value_commit(desc, value); + return gpio_set_open_drain_value_commit(desc, value); else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) - gpio_set_open_source_value_commit(desc, value); - else - gpiod_set_raw_value_commit(desc, value); + return gpio_set_open_source_value_commit(desc, value); + + return gpiod_set_raw_value_commit(desc, value); } /** @@ -3411,13 +3864,16 @@ static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value) * * This function can be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. + * + * Returns: + * 0 on success, negative error number on failure. */ -void gpiod_set_value(struct gpio_desc *desc, int value) +int gpiod_set_value(struct gpio_desc *desc, int value) { - VALIDATE_DESC_VOID(desc); + VALIDATE_DESC(desc); /* Should be using gpiod_set_value_cansleep() */ - WARN_ON(desc->gdev->chip->can_sleep); - gpiod_set_value_nocheck(desc, value); + WARN_ON(desc->gdev->can_sleep); + return gpiod_set_value_nocheck(desc, value); } EXPORT_SYMBOL_GPL(gpiod_set_value); @@ -3433,6 +3889,9 @@ EXPORT_SYMBOL_GPL(gpiod_set_value); * * This function can be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. + * + * Returns: + * 0 on success, or negative errno on failure. */ int gpiod_set_raw_array_value(unsigned int array_size, struct gpio_desc **desc_array, @@ -3458,6 +3917,9 @@ EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value); * * This function can be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. + * + * Returns: + * 0 on success, or negative errno on failure. */ int gpiod_set_array_value(unsigned int array_size, struct gpio_desc **desc_array, @@ -3476,11 +3938,13 @@ EXPORT_SYMBOL_GPL(gpiod_set_array_value); * gpiod_cansleep() - report whether gpio value access may sleep * @desc: gpio to check * + * Returns: + * 0 for non-sleepable, 1 for sleepable, or an error code in case of error. */ int gpiod_cansleep(const struct gpio_desc *desc) { VALIDATE_DESC(desc); - return desc->gdev->chip->can_sleep; + return desc->gdev->can_sleep; } EXPORT_SYMBOL_GPL(gpiod_cansleep); @@ -3488,20 +3952,21 @@ EXPORT_SYMBOL_GPL(gpiod_cansleep); * gpiod_set_consumer_name() - set the consumer name for the descriptor * @desc: gpio to set the consumer name on * @name: the new consumer name + * + * Returns: + * 0 on success, or negative errno on failure. */ int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name) { + int ret; + VALIDATE_DESC(desc); - if (name) { - name = kstrdup_const(name, GFP_KERNEL); - if (!name) - return -ENOMEM; - } - kfree_const(desc->label); - desc_set_label(desc, name); + ret = desc_set_label(desc, name); + if (ret == 0) + gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG); - return 0; + return ret; } EXPORT_SYMBOL_GPL(gpiod_set_consumer_name); @@ -3509,32 +3974,35 @@ EXPORT_SYMBOL_GPL(gpiod_set_consumer_name); * gpiod_to_irq() - return the IRQ corresponding to a GPIO * @desc: gpio whose IRQ will be returned (already requested) * - * Return the IRQ corresponding to the passed GPIO, or an error code in case of - * error. + * Returns: + * The IRQ corresponding to the passed GPIO, or an error code in case of error. */ int gpiod_to_irq(const struct gpio_desc *desc) { + struct gpio_device *gdev; struct gpio_chip *gc; int offset; + int ret; - /* - * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics - * requires this function to not return zero on an invalid descriptor - * but rather a negative error number. - */ - if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip) + ret = validate_desc(desc, __func__); + if (ret <= 0) return -EINVAL; - gc = desc->gdev->chip; + gdev = desc->gdev; + /* FIXME Cannot use gpio_chip_guard due to const desc. */ + guard(srcu)(&gdev->srcu); + gc = srcu_dereference(gdev->chip, &gdev->srcu); + if (!gc) + return -ENODEV; + offset = gpio_chip_hwgpio(desc); if (gc->to_irq) { - int retirq = gc->to_irq(gc, offset); + ret = gc->to_irq(gc, offset); + if (ret) + return ret; /* Zero means NO_IRQ */ - if (!retirq) - return -ENXIO; - - return retirq; + return -ENXIO; } #ifdef CONFIG_GPIOLIB_IRQCHIP if (gc->irq.chip) { @@ -3557,6 +4025,9 @@ EXPORT_SYMBOL_GPL(gpiod_to_irq); * * This is used directly by GPIO drivers that want to lock down * a certain GPIO line to be used for IRQs. + * + * Returns: + * 0 on success, or negative errno on failure. */ int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset) { @@ -3592,14 +4063,6 @@ int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset) set_bit(FLAG_USED_AS_IRQ, &desc->flags); set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags); - /* - * If the consumer has not set up a label (such as when the - * IRQ is referenced from .to_irq()) we set up a label here - * so it is clear this is used as an interrupt. - */ - if (!desc->label) - desc_set_label(desc, "interrupt"); - return 0; } EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq); @@ -3622,10 +4085,6 @@ void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset) clear_bit(FLAG_USED_AS_IRQ, &desc->flags); clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags); - - /* If we only had this marking, erase it */ - if (desc->label && !strcmp(desc->label, "interrupt")) - desc_set_label(desc, NULL); } EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq); @@ -3720,7 +4179,8 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent); * gpiod_get_raw_value_cansleep() - return a gpio's raw value * @desc: gpio whose value will be returned * - * Return the GPIO's raw value, i.e. the value of the physical line disregarding + * Returns: + * The GPIO's raw value, i.e. the value of the physical line disregarding * its ACTIVE_LOW status, or negative errno on failure. * * This function is to be called from contexts that can sleep. @@ -3737,7 +4197,8 @@ EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep); * gpiod_get_value_cansleep() - return a gpio's value * @desc: gpio whose value will be returned * - * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into + * Returns: + * The GPIO's logical value, i.e. taking the ACTIVE_LOW status into * account, or negative errno on failure. * * This function is to be called from contexts that can sleep. @@ -3767,10 +4228,12 @@ EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep); * @value_bitmap: bitmap to store the read values * * Read the raw values of the GPIOs, i.e. the values of the physical lines - * without regard for their ACTIVE_LOW status. Return 0 in case of success, - * else an error code. + * without regard for their ACTIVE_LOW status. * * This function is to be called from contexts that can sleep. + * + * Returns: + * 0 on success, or negative errno on failure. */ int gpiod_get_raw_array_value_cansleep(unsigned int array_size, struct gpio_desc **desc_array, @@ -3794,9 +4257,12 @@ EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep); * @value_bitmap: bitmap to store the read values * * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status - * into account. Return 0 in case of success, else an error code. + * into account. * * This function is to be called from contexts that can sleep. + * + * Returns: + * 0 on success, or negative errno on failure. */ int gpiod_get_array_value_cansleep(unsigned int array_size, struct gpio_desc **desc_array, @@ -3821,12 +4287,15 @@ EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep); * regard for its ACTIVE_LOW status. * * This function is to be called from contexts that can sleep. + * + * Returns: + * 0 on success, negative error number on failure. */ -void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value) +int gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value) { might_sleep(); - VALIDATE_DESC_VOID(desc); - gpiod_set_raw_value_commit(desc, value); + VALIDATE_DESC(desc); + return gpiod_set_raw_value_commit(desc, value); } EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep); @@ -3839,12 +4308,15 @@ EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep); * account * * This function is to be called from contexts that can sleep. + * + * Returns: + * 0 on success, negative error number on failure. */ -void gpiod_set_value_cansleep(struct gpio_desc *desc, int value) +int gpiod_set_value_cansleep(struct gpio_desc *desc, int value) { might_sleep(); - VALIDATE_DESC_VOID(desc); - gpiod_set_value_nocheck(desc, value); + VALIDATE_DESC(desc); + return gpiod_set_value_nocheck(desc, value); } EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep); @@ -3859,6 +4331,9 @@ EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep); * without regard for their ACTIVE_LOW status. * * This function is to be called from contexts that can sleep. + * + * Returns: + * 0 on success, or negative errno on failure. */ int gpiod_set_raw_array_value_cansleep(unsigned int array_size, struct gpio_desc **desc_array, @@ -3882,12 +4357,10 @@ void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n) { unsigned int i; - mutex_lock(&gpio_lookup_lock); + guard(mutex)(&gpio_lookup_lock); for (i = 0; i < n; i++) list_add_tail(&tables[i]->list, &gpio_lookup_list); - - mutex_unlock(&gpio_lookup_lock); } /** @@ -3901,6 +4374,9 @@ void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n) * into account. * * This function is to be called from contexts that can sleep. + * + * Returns: + * 0 on success, or negative errno on failure. */ int gpiod_set_array_value_cansleep(unsigned int array_size, struct gpio_desc **desc_array, @@ -3918,8 +4394,9 @@ EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep); void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action) { - blocking_notifier_call_chain(&desc->gdev->line_state_notifier, - action, desc); + guard(read_lock_irqsave)(&desc->gdev->line_state_lock); + + raw_notifier_call_chain(&desc->gdev->line_state_notifier, action, desc); } /** @@ -3942,11 +4419,9 @@ void gpiod_remove_lookup_table(struct gpiod_lookup_table *table) if (!table) return; - mutex_lock(&gpio_lookup_lock); + guard(mutex)(&gpio_lookup_lock); list_del(&table->list); - - mutex_unlock(&gpio_lookup_lock); } EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table); @@ -3958,7 +4433,7 @@ void gpiod_add_hogs(struct gpiod_hog *hogs) { struct gpiod_hog *hog; - mutex_lock(&gpio_machine_hogs_mutex); + guard(mutex)(&gpio_machine_hogs_mutex); for (hog = &hogs[0]; hog->chip_label; hog++) { list_add_tail(&hog->list, &gpio_machine_hogs); @@ -3972,8 +4447,6 @@ void gpiod_add_hogs(struct gpiod_hog *hogs) if (gdev) gpiochip_machine_hog(gpio_device_get_chip(gdev), hog); } - - mutex_unlock(&gpio_machine_hogs_mutex); } EXPORT_SYMBOL_GPL(gpiod_add_hogs); @@ -3981,10 +4454,10 @@ void gpiod_remove_hogs(struct gpiod_hog *hogs) { struct gpiod_hog *hog; - mutex_lock(&gpio_machine_hogs_mutex); + guard(mutex)(&gpio_machine_hogs_mutex); + for (hog = &hogs[0]; hog->chip_label; hog++) list_del(&hog->list); - mutex_unlock(&gpio_machine_hogs_mutex); } EXPORT_SYMBOL_GPL(gpiod_remove_hogs); @@ -4114,58 +4587,65 @@ static struct gpio_desc *gpiod_find_by_fwnode(struct fwnode_handle *fwnode, enum gpiod_flags *flags, unsigned long *lookupflags) { + const char *name = function_name_or_default(con_id); struct gpio_desc *desc = ERR_PTR(-ENOENT); if (is_of_node(fwnode)) { - dev_dbg(consumer, "using DT '%pfw' for '%s' GPIO lookup\n", - fwnode, con_id); + dev_dbg(consumer, "using DT '%pfw' for '%s' GPIO lookup\n", fwnode, name); desc = of_find_gpio(to_of_node(fwnode), con_id, idx, lookupflags); } else if (is_acpi_node(fwnode)) { - dev_dbg(consumer, "using ACPI '%pfw' for '%s' GPIO lookup\n", - fwnode, con_id); + dev_dbg(consumer, "using ACPI '%pfw' for '%s' GPIO lookup\n", fwnode, name); desc = acpi_find_gpio(fwnode, con_id, idx, flags, lookupflags); } else if (is_software_node(fwnode)) { - dev_dbg(consumer, "using swnode '%pfw' for '%s' GPIO lookup\n", - fwnode, con_id); + dev_dbg(consumer, "using swnode '%pfw' for '%s' GPIO lookup\n", fwnode, name); desc = swnode_find_gpio(fwnode, con_id, idx, lookupflags); } return desc; } -static struct gpio_desc *gpiod_find_and_request(struct device *consumer, - struct fwnode_handle *fwnode, - const char *con_id, - unsigned int idx, - enum gpiod_flags flags, - const char *label, - bool platform_lookup_allowed) +struct gpio_desc *gpiod_find_and_request(struct device *consumer, + struct fwnode_handle *fwnode, + const char *con_id, + unsigned int idx, + enum gpiod_flags flags, + const char *label, + bool platform_lookup_allowed) { unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT; - struct gpio_desc *desc; - int ret; + const char *name = function_name_or_default(con_id); + /* + * scoped_guard() is implemented as a for loop, meaning static + * analyzers will complain about these two not being initialized. + */ + struct gpio_desc *desc = NULL; + int ret = 0; + + scoped_guard(srcu, &gpio_devices_srcu) { + desc = gpiod_find_by_fwnode(fwnode, consumer, con_id, idx, + &flags, &lookupflags); + if (gpiod_not_found(desc) && platform_lookup_allowed) { + /* + * Either we are not using DT or ACPI, or their lookup + * did not return a result. In that case, use platform + * lookup as a fallback. + */ + dev_dbg(consumer, + "using lookup tables for GPIO lookup\n"); + desc = gpiod_find(consumer, con_id, idx, &lookupflags); + } + + if (IS_ERR(desc)) { + dev_dbg(consumer, "No GPIO consumer %s found\n", name); + return desc; + } - desc = gpiod_find_by_fwnode(fwnode, consumer, con_id, idx, &flags, &lookupflags); - if (gpiod_not_found(desc) && platform_lookup_allowed) { /* - * Either we are not using DT or ACPI, or their lookup did not - * return a result. In that case, use platform lookup as a - * fallback. + * If a connection label was passed use that, else attempt to use + * the device name as label */ - dev_dbg(consumer, "using lookup tables for GPIO lookup\n"); - desc = gpiod_find(consumer, con_id, idx, &lookupflags); - } - - if (IS_ERR(desc)) { - dev_dbg(consumer, "No GPIO consumer %s found\n", con_id); - return desc; + ret = gpiod_request(desc, label); } - - /* - * If a connection label was passed use that, else attempt to use - * the device name as label - */ - ret = gpiod_request(desc, label); if (ret) { if (!(ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE)) return ERR_PTR(ret); @@ -4178,19 +4658,18 @@ static struct gpio_desc *gpiod_find_and_request(struct device *consumer, * * FIXME: Make this more sane and safe. */ - dev_info(consumer, - "nonexclusive access to GPIO for %s\n", con_id); + dev_info(consumer, "nonexclusive access to GPIO for %s\n", name); return desc; } ret = gpiod_configure_flags(desc, con_id, lookupflags, flags); if (ret < 0) { - dev_dbg(consumer, "setup of GPIO %s failed\n", con_id); gpiod_put(desc); + dev_err(consumer, "setup of GPIO %s failed: %d\n", name, ret); return ERR_PTR(ret); } - gpiod_line_state_notify(desc, GPIOLINE_CHANGED_REQUESTED); + gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_REQUESTED); return desc; } @@ -4228,9 +4707,12 @@ EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index); /** * gpiod_count - return the number of GPIOs associated with a device / function - * or -ENOENT if no GPIO has been assigned to the requested function * @dev: GPIO consumer, can be NULL for system-global GPIOs * @con_id: function within the GPIO consumer + * + * Returns: + * The number of GPIOs associated with a device / function or -ENOENT if no + * GPIO has been assigned to the requested function. */ int gpiod_count(struct device *dev, const char *con_id) { @@ -4238,9 +4720,9 @@ int gpiod_count(struct device *dev, const char *con_id) int count = -ENOENT; if (is_of_node(fwnode)) - count = of_gpio_get_count(dev, con_id); + count = of_gpio_count(fwnode, con_id); else if (is_acpi_node(fwnode)) - count = acpi_gpio_count(dev, con_id); + count = acpi_gpio_count(fwnode, con_id); else if (is_software_node(fwnode)) count = swnode_gpio_count(fwnode, con_id); @@ -4257,7 +4739,8 @@ EXPORT_SYMBOL_GPL(gpiod_count); * @con_id: function within the GPIO consumer * @flags: optional GPIO initialization flags * - * Return the GPIO descriptor corresponding to the function con_id of device + * Returns: + * The GPIO descriptor corresponding to the function @con_id of device * dev, -ENOENT if no GPIO has been assigned to the requested function, or * another IS_ERR() code if an error occurred while trying to acquire the GPIO. */ @@ -4277,6 +4760,11 @@ EXPORT_SYMBOL_GPL(gpiod_get); * This is equivalent to gpiod_get(), except that when no GPIO was assigned to * the requested function it will return NULL. This is convenient for drivers * that need to handle optional GPIOs. + * + * Returns: + * The GPIO descriptor corresponding to the function @con_id of device + * dev, NULL if no GPIO has been assigned to the requested function, or + * another IS_ERR() code if an error occurred while trying to acquire the GPIO. */ struct gpio_desc *__must_check gpiod_get_optional(struct device *dev, const char *con_id, @@ -4295,13 +4783,15 @@ EXPORT_SYMBOL_GPL(gpiod_get_optional); * of_find_gpio() or of_get_gpio_hog() * @dflags: gpiod_flags - optional GPIO initialization flags * - * Return 0 on success, -ENOENT if no GPIO has been assigned to the + * Returns: + * 0 on success, -ENOENT if no GPIO has been assigned to the * requested function and/or index, or another IS_ERR() code if an error * occurred while trying to acquire the GPIO. */ int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, unsigned long lflags, enum gpiod_flags dflags) { + const char *name = function_name_or_default(con_id); int ret; if (lflags & GPIO_ACTIVE_LOW) @@ -4345,16 +4835,16 @@ int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, /* No particular flag request, return here... */ if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) { - gpiod_dbg(desc, "no flags found for %s\n", con_id); + gpiod_dbg(desc, "no flags found for GPIO %s\n", name); return 0; } /* Process flags */ if (dflags & GPIOD_FLAGS_BIT_DIR_OUT) - ret = gpiod_direction_output(desc, + ret = gpiod_direction_output_nonotify(desc, !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL)); else - ret = gpiod_direction_input(desc); + ret = gpiod_direction_input_nonotify(desc); return ret; } @@ -4369,7 +4859,8 @@ int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, * This variant of gpiod_get() allows to access GPIOs other than the first * defined one for functions that define several GPIOs. * - * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the + * Returns: + * A valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the * requested function and/or index, or another IS_ERR() code if an error * occurred while trying to acquire the GPIO. */ @@ -4397,6 +4888,11 @@ EXPORT_SYMBOL_GPL(gpiod_get_index); * This is equivalent to gpiod_get_index(), except that when no GPIO with the * specified index was assigned to the requested function it will return NULL. * This is convenient for drivers that need to handle optional GPIOs. + * + * Returns: + * A valid GPIO descriptor, NULL if no GPIO has been assigned to the + * requested function and/or index, or another IS_ERR() code if an error + * occurred while trying to acquire the GPIO. */ struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev, const char *con_id, @@ -4420,34 +4916,41 @@ EXPORT_SYMBOL_GPL(gpiod_get_index_optional); * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from * of_find_gpio() or of_get_gpio_hog() * @dflags: gpiod_flags - optional GPIO initialization flags + * + * Returns: + * 0 on success, or negative errno on failure. */ int gpiod_hog(struct gpio_desc *desc, const char *name, unsigned long lflags, enum gpiod_flags dflags) { - struct gpio_chip *gc; + struct gpio_device *gdev = desc->gdev; struct gpio_desc *local_desc; int hwnum; int ret; - gc = gpiod_to_chip(desc); + CLASS(gpio_chip_guard, guard)(desc); + if (!guard.gc) + return -ENODEV; + + if (test_and_set_bit(FLAG_IS_HOGGED, &desc->flags)) + return 0; + hwnum = gpio_chip_hwgpio(desc); - local_desc = gpiochip_request_own_desc(gc, hwnum, name, + local_desc = gpiochip_request_own_desc(guard.gc, hwnum, name, lflags, dflags); if (IS_ERR(local_desc)) { + clear_bit(FLAG_IS_HOGGED, &desc->flags); ret = PTR_ERR(local_desc); pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n", - name, gc->label, hwnum, ret); + name, gdev->label, hwnum, ret); return ret; } - /* Mark GPIO as hogged so it can be identified and removed later */ - set_bit(FLAG_IS_HOGGED, &desc->flags); - - gpiod_dbg(desc, "hogged as %s%s\n", + gpiod_dbg(desc, "hogged as %s/%s\n", (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input", (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? - (dflags & GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low" : ""); + str_high_low(dflags & GPIOD_FLAGS_BIT_DIR_VAL) : "?"); return 0; } @@ -4472,9 +4975,11 @@ static void gpiochip_free_hogs(struct gpio_chip *gc) * * This function acquires all the GPIOs defined under a given function. * - * Return a struct gpio_descs containing an array of descriptors, -ENOENT if - * no GPIO has been assigned to the requested function, or another IS_ERR() - * code if an error occurred while trying to acquire the GPIOs. + * Returns: + * The GPIO descriptors corresponding to the function @con_id of device + * dev, -ENOENT if no GPIO has been assigned to the requested function, + * or another IS_ERR() code if an error occurred while trying to acquire + * the GPIOs. */ struct gpio_descs *__must_check gpiod_get_array(struct device *dev, const char *con_id, @@ -4482,9 +4987,10 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev, { struct gpio_desc *desc; struct gpio_descs *descs; + struct gpio_device *gdev; struct gpio_array *array_info = NULL; - struct gpio_chip *gc; int count, bitmap_size; + unsigned long dflags; size_t descs_size; count = gpiod_count(dev, con_id); @@ -4505,7 +5011,7 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev, descs->desc[descs->ndescs] = desc; - gc = gpiod_to_chip(desc); + gdev = gpiod_to_gpio_device(desc); /* * If pin hardware number of array member 0 is also 0, select * its chip as a candidate for fast bitmap processing path. @@ -4513,8 +5019,8 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev, if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) { struct gpio_descs *array; - bitmap_size = BITS_TO_LONGS(gc->ngpio > count ? - gc->ngpio : count); + bitmap_size = BITS_TO_LONGS(gdev->ngpio > count ? + gdev->ngpio : count); array = krealloc(descs, descs_size + struct_size(array_info, invert_mask, 3 * bitmap_size), @@ -4534,7 +5040,7 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev, array_info->desc = descs->desc; array_info->size = count; - array_info->chip = gc; + array_info->gdev = gdev; bitmap_set(array_info->get_mask, descs->ndescs, count - descs->ndescs); bitmap_set(array_info->set_mask, descs->ndescs, @@ -4547,7 +5053,7 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev, continue; /* Unmark array members which don't belong to the 'fast' chip */ - if (array_info->chip != gc) { + if (array_info->gdev != gdev) { __clear_bit(descs->ndescs, array_info->get_mask); __clear_bit(descs->ndescs, array_info->set_mask); } @@ -4570,9 +5076,10 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev, array_info->set_mask); } } else { + dflags = READ_ONCE(desc->flags); /* Exclude open drain or open source from fast output */ - if (gpiochip_line_is_open_drain(gc, descs->ndescs) || - gpiochip_line_is_open_source(gc, descs->ndescs)) + if (test_bit(FLAG_OPEN_DRAIN, &dflags) || + test_bit(FLAG_OPEN_SOURCE, &dflags)) __clear_bit(descs->ndescs, array_info->set_mask); /* Identify 'fast' pins which require invertion */ @@ -4584,7 +5091,7 @@ struct gpio_descs *__must_check gpiod_get_array(struct device *dev, if (array_info) dev_dbg(dev, "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n", - array_info->chip->label, array_info->size, + array_info->gdev->label, array_info->size, *array_info->get_mask, *array_info->set_mask, *array_info->invert_mask); return descs; @@ -4600,6 +5107,12 @@ EXPORT_SYMBOL_GPL(gpiod_get_array); * * This is equivalent to gpiod_get_array(), except that when no GPIO was * assigned to the requested function it will return NULL. + * + * Returns: + * The GPIO descriptors corresponding to the function @con_id of device + * dev, NULL if no GPIO has been assigned to the requested function, + * or another IS_ERR() code if an error occurred while trying to acquire + * the GPIOs. */ struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev, const char *con_id, @@ -4623,8 +5136,7 @@ EXPORT_SYMBOL_GPL(gpiod_get_array_optional); */ void gpiod_put(struct gpio_desc *desc) { - if (desc) - gpiod_free(desc); + gpiod_free(desc); } EXPORT_SYMBOL_GPL(gpiod_put); @@ -4707,90 +5219,114 @@ core_initcall(gpiolib_dev_init); static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev) { - struct gpio_chip *gc = gdev->chip; bool active_low, is_irq, is_out; unsigned int gpio = gdev->base; struct gpio_desc *desc; + struct gpio_chip *gc; + unsigned long flags; int value; + guard(srcu)(&gdev->srcu); + + gc = srcu_dereference(gdev->chip, &gdev->srcu); + if (!gc) { + seq_puts(s, "Underlying GPIO chip is gone\n"); + return; + } + for_each_gpio_desc(gc, desc) { - if (test_bit(FLAG_REQUESTED, &desc->flags)) { + guard(srcu)(&desc->gdev->desc_srcu); + flags = READ_ONCE(desc->flags); + is_irq = test_bit(FLAG_USED_AS_IRQ, &flags); + if (is_irq || test_bit(FLAG_REQUESTED, &flags)) { gpiod_get_direction(desc); - is_out = test_bit(FLAG_IS_OUT, &desc->flags); + is_out = test_bit(FLAG_IS_OUT, &flags); value = gpio_chip_get_value(gc, desc); - is_irq = test_bit(FLAG_USED_AS_IRQ, &desc->flags); - active_low = test_bit(FLAG_ACTIVE_LOW, &desc->flags); - seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s\n", - gpio, desc->name ?: "", desc->label, + active_low = test_bit(FLAG_ACTIVE_LOW, &flags); + seq_printf(s, " gpio-%-3u (%-20.20s|%-20.20s) %s %s %s%s\n", + gpio, desc->name ?: "", gpiod_get_label(desc), is_out ? "out" : "in ", - value >= 0 ? (value ? "hi" : "lo") : "? ", + value >= 0 ? str_hi_lo(value) : "? ", is_irq ? "IRQ " : "", active_low ? "ACTIVE LOW" : ""); } else if (desc->name) { - seq_printf(s, " gpio-%-3d (%-20.20s)\n", gpio, desc->name); + seq_printf(s, " gpio-%-3u (%-20.20s)\n", gpio, desc->name); } gpio++; } } +struct gpiolib_seq_priv { + bool newline; + int idx; +}; + static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos) { - unsigned long flags; - struct gpio_device *gdev = NULL; + struct gpiolib_seq_priv *priv; + struct gpio_device *gdev; loff_t index = *pos; - s->private = ""; + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) + return NULL; + + s->private = priv; + if (*pos > 0) + priv->newline = true; + priv->idx = srcu_read_lock(&gpio_devices_srcu); - spin_lock_irqsave(&gpio_lock, flags); - list_for_each_entry(gdev, &gpio_devices, list) - if (index-- == 0) { - spin_unlock_irqrestore(&gpio_lock, flags); + list_for_each_entry_srcu(gdev, &gpio_devices, list, + srcu_read_lock_held(&gpio_devices_srcu)) { + if (index-- == 0) return gdev; - } - spin_unlock_irqrestore(&gpio_lock, flags); + } return NULL; } static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos) { - unsigned long flags; - struct gpio_device *gdev = v; - void *ret = NULL; - - spin_lock_irqsave(&gpio_lock, flags); - if (list_is_last(&gdev->list, &gpio_devices)) - ret = NULL; - else - ret = list_first_entry(&gdev->list, struct gpio_device, list); - spin_unlock_irqrestore(&gpio_lock, flags); + struct gpiolib_seq_priv *priv = s->private; + struct gpio_device *gdev = v, *next; - s->private = "\n"; + next = list_entry_rcu(gdev->list.next, struct gpio_device, list); + gdev = &next->list == &gpio_devices ? NULL : next; + priv->newline = true; ++*pos; - return ret; + return gdev; } static void gpiolib_seq_stop(struct seq_file *s, void *v) { + struct gpiolib_seq_priv *priv = s->private; + + srcu_read_unlock(&gpio_devices_srcu, priv->idx); + kfree(priv); } static int gpiolib_seq_show(struct seq_file *s, void *v) { + struct gpiolib_seq_priv *priv = s->private; struct gpio_device *gdev = v; - struct gpio_chip *gc = gdev->chip; + struct gpio_chip *gc; struct device *parent; + if (priv->newline) + seq_putc(s, '\n'); + + guard(srcu)(&gdev->srcu); + + gc = srcu_dereference(gdev->chip, &gdev->srcu); if (!gc) { - seq_printf(s, "%s%s: (dangling chip)", (char *)s->private, - dev_name(&gdev->dev)); + seq_printf(s, "%s: (dangling chip)\n", dev_name(&gdev->dev)); return 0; } - seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private, - dev_name(&gdev->dev), - gdev->base, gdev->base + gdev->ngpio - 1); + seq_printf(s, "%s: GPIOs %u-%u", dev_name(&gdev->dev), gdev->base, + gdev->base + gdev->ngpio - 1); parent = gc->parent; if (parent) seq_printf(s, ", parent: %s/%s", |