diff options
Diffstat (limited to 'drivers/gpio/gpiolib-swnode.c')
| -rw-r--r-- | drivers/gpio/gpiolib-swnode.c | 104 |
1 files changed, 72 insertions, 32 deletions
diff --git a/drivers/gpio/gpiolib-swnode.c b/drivers/gpio/gpiolib-swnode.c index fa52bdb1a29a..f21dbc28cf2c 100644 --- a/drivers/gpio/gpiolib-swnode.c +++ b/drivers/gpio/gpiolib-swnode.c @@ -4,8 +4,13 @@ * * Copyright 2022 Google LLC */ + +#define pr_fmt(fmt) "gpiolib: swnode: " fmt + #include <linux/err.h> #include <linux/errno.h> +#include <linux/export.h> +#include <linux/init.h> #include <linux/kernel.h> #include <linux/printk.h> #include <linux/property.h> @@ -17,19 +22,7 @@ #include "gpiolib.h" #include "gpiolib-swnode.h" -static void swnode_format_propname(const char *con_id, char *propname, - size_t max_size) -{ - /* - * Note we do not need to try both -gpios and -gpio suffixes, - * as, unlike OF and ACPI, we can fix software nodes to conform - * to the proper binding. - */ - if (con_id) - snprintf(propname, max_size, "%s-gpios", con_id); - else - strscpy(propname, "gpios", max_size); -} +#define GPIOLIB_SWNODE_UNDEFINED_NAME "swnode-gpio-undefined" static struct gpio_device *swnode_get_gpio_device(struct fwnode_handle *fwnode) { @@ -40,10 +33,29 @@ static struct gpio_device *swnode_get_gpio_device(struct fwnode_handle *fwnode) if (!gdev_node || !gdev_node->name) return ERR_PTR(-EINVAL); + /* + * Check for a special node that identifies undefined GPIOs, this is + * primarily used as a key for internal chip selects in SPI bindings. + */ + if (IS_ENABLED(CONFIG_GPIO_SWNODE_UNDEFINED) && + !strcmp(gdev_node->name, GPIOLIB_SWNODE_UNDEFINED_NAME)) + return ERR_PTR(-ENOENT); + gdev = gpio_device_find_by_label(gdev_node->name); return gdev ?: ERR_PTR(-EPROBE_DEFER); } +static int swnode_gpio_get_reference(const struct fwnode_handle *fwnode, + const char *propname, unsigned int idx, + struct fwnode_reference_args *args) +{ + /* + * We expect all swnode-described GPIOs have GPIO number and + * polarity arguments, hence nargs is set to 2. + */ + return fwnode_property_get_reference_args(fwnode, propname, NULL, 2, idx, args); +} + struct gpio_desc *swnode_find_gpio(struct fwnode_handle *fwnode, const char *con_id, unsigned int idx, unsigned long *flags) @@ -52,23 +64,21 @@ struct gpio_desc *swnode_find_gpio(struct fwnode_handle *fwnode, struct fwnode_reference_args args; struct gpio_desc *desc; char propname[32]; /* 32 is max size of property name */ - int error; + int ret = 0; swnode = to_software_node(fwnode); if (!swnode) return ERR_PTR(-EINVAL); - swnode_format_propname(con_id, propname, sizeof(propname)); - - /* - * We expect all swnode-described GPIOs have GPIO number and - * polarity arguments, hence nargs is set to 2. - */ - error = fwnode_property_get_reference_args(fwnode, propname, NULL, 2, idx, &args); - if (error) { + for_each_gpio_property_name(propname, con_id) { + ret = swnode_gpio_get_reference(fwnode, propname, idx, &args); + if (ret == 0) + break; + } + if (ret) { pr_debug("%s: can't parse '%s' property of node '%pfwP[%d]'\n", __func__, propname, fwnode, idx); - return ERR_PTR(error); + return ERR_PTR(ret); } struct gpio_device *gdev __free(gpio_device_put) = @@ -96,7 +106,7 @@ struct gpio_desc *swnode_find_gpio(struct fwnode_handle *fwnode, * system-global GPIOs * @con_id: function within the GPIO consumer * - * Return: + * Returns: * The number of GPIOs associated with a device / function or %-ENOENT, * if no GPIO has been assigned to the requested function. */ @@ -106,18 +116,48 @@ int swnode_gpio_count(const struct fwnode_handle *fwnode, const char *con_id) char propname[32]; int count; - swnode_format_propname(con_id, propname, sizeof(propname)); - /* * This is not very efficient, but GPIO lists usually have only * 1 or 2 entries. */ - count = 0; - while (fwnode_property_get_reference_args(fwnode, propname, NULL, 0, - count, &args) == 0) { - fwnode_handle_put(args.fwnode); - count++; + for_each_gpio_property_name(propname, con_id) { + count = 0; + while (swnode_gpio_get_reference(fwnode, propname, count, &args) == 0) { + fwnode_handle_put(args.fwnode); + count++; + } + if (count) + return count; } - return count ?: -ENOENT; + return -ENOENT; +} + +#if IS_ENABLED(CONFIG_GPIO_SWNODE_UNDEFINED) +/* + * A special node that identifies undefined GPIOs, this is primarily used as + * a key for internal chip selects in SPI bindings. + */ +const struct software_node swnode_gpio_undefined = { + .name = GPIOLIB_SWNODE_UNDEFINED_NAME, +}; +EXPORT_SYMBOL_NS_GPL(swnode_gpio_undefined, "GPIO_SWNODE"); + +static int __init swnode_gpio_init(void) +{ + int ret; + + ret = software_node_register(&swnode_gpio_undefined); + if (ret < 0) + pr_err("failed to register swnode: %d\n", ret); + + return ret; +} +subsys_initcall(swnode_gpio_init); + +static void __exit swnode_gpio_cleanup(void) +{ + software_node_unregister(&swnode_gpio_undefined); } +__exitcall(swnode_gpio_cleanup); +#endif |