diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-01-17 12:32:01 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-01-17 12:32:01 -0800 |
commit | 58cf279acac3080ce03eeea5ca268210b3165fe1 (patch) | |
tree | 54997706fbfea2cd9fd4c4044edbd8ecdc154dfb /drivers/gpio/gpio-104-idi-48.c | |
parent | 6606b342febfd470b4a33acb73e360eeaca1d9bb (diff) | |
parent | c474e348778bdf5b453a2cdff4b2b1f9e000f343 (diff) |
Merge tag 'gpio-v4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull GPIO updates from Linus Walleij:
"Here is the bulk of GPIO changes for v4.5.
Notably there are big refactorings mostly by myself, aimed at getting
the gpio_chip into a shape that makes me believe I can proceed to
preserve state for a proper userspace ABI (character device) that has
already been proposed once, but resulted in the feedback that I need
to go back and restructure stuff. So I've been restructuring stuff.
On the way I ran into brokenness (return code from the get_value()
callback) and had to fix it. Also, refactored generic GPIO to be
simpler.
Some of that is still waiting to trickle down from the subsystems all
over the kernel that provide random gpio_chips, I've touched every
single GPIO driver in the kernel now, oh man I didn't know I was
responsible for so much...
Apart from that we're churning along as usual.
I took some effort to test and retest so it should merge nicely and we
shook out a couple of bugs in -next.
Infrastructural changes:
- In struct gpio_chip, rename the .dev node to .parent to better
reflect the fact that this is not the GPIO struct device
abstraction. We will add that soon so this would be totallt
confusing.
- It was noted that the driver .get_value() callbacks was sometimes
reporting negative -ERR values to the gpiolib core, expecting them
to be propagated to consumer gpiod_get_value() and gpio_get_value()
calls. This was not happening, so as there was a mess of drivers
returning negative errors and some returning "anything else than
zero" to indicate that a line was active. As some would have bit
31 set to indicate "line active" it clashed with negative error
codes. This is fixed by the largeish series clamping values in all
drivers with !!value to [0,1] and then augmenting the code to
propagate error codes to consumers. (Includes some ACKed patches
in other subsystems.)
- Add a void *data pointer to struct gpio_chip. The container_of()
design pattern is indeed very nice, but we want to reform the
struct gpio_chip to be a non-volative, stateless business, and keep
states internal to the gpiolib to be able to hold on to the state
when adding a proper userspace ABI (character device) further down
the road. To achieve this, drivers need a handle at the internal
state that is not dependent on their struct gpio_chip() so we add
gpiochip_add_data() and gpiochip_get_data() following the pattern
of many other subsystems. All the "use gpiochip data pointer"
patches transforms drivers to this scheme.
- The Generic GPIO chip header has been merged into the general
<linux/gpio/driver.h> header, and the custom header for that
removed. Instead of having a separate mm_gpio_chip struct for
these generic drivers, merge that into struct gpio_chip,
simplifying the code and removing the need for separate and
confusing includes.
Misc improvements:
- Stabilize the way GPIOs are looked up from the ACPI legacy
specification.
- Incremental driver features for PXA, PCA953X, Lantiq (patches from
the OpenWRT community), RCAR, Zynq, PL061, 104-idi-48
New drivers:
- Add a GPIO chip to the ALSA SoC AC97 driver.
- Add a new Broadcom NSP SoC driver (this lands in the pinctrl dir,
but the branch is merged here too to account for infrastructural
changes).
- The sx150x driver now supports the sx1502"
* tag 'gpio-v4.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (220 commits)
gpio: generic: make bgpio_pdata always visible
gpiolib: fix chip order in gpio list
gpio: mpc8xxx: Do not use gpiochip_get_data() in mpc8xxx_gpio_save_regs()
gpio: mm-lantiq: Do not use gpiochip_get_data() in ltq_mm_save_regs()
gpio: brcmstb: Allow building driver for BMIPS_GENERIC
gpio: brcmstb: Set endian flags for big-endian MIPS
gpio: moxart: fix build regression
gpio: xilinx: Do not use gpiochip_get_data() in xgpio_save_regs()
leds: pca9532: use gpiochip data pointer
leds: tca6507: use gpiochip data pointer
hid: cp2112: use gpiochip data pointer
bcma: gpio: use gpiochip data pointer
avr32: gpio: use gpiochip data pointer
video: fbdev: via: use gpiochip data pointer
gpio: pch: Optimize pch_gpio_get()
Revert "pinctrl: lantiq: Implement gpio_chip.to_irq"
pinctrl: nsp-gpio: use gpiochip data pointer
pinctrl: vt8500-wmt: use gpiochip data pointer
pinctrl: exynos5440: use gpiochip data pointer
pinctrl: at91-pio4: use gpiochip data pointer
...
Diffstat (limited to 'drivers/gpio/gpio-104-idi-48.c')
-rw-r--r-- | drivers/gpio/gpio-104-idi-48.c | 343 |
1 files changed, 343 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-104-idi-48.c b/drivers/gpio/gpio-104-idi-48.c new file mode 100644 index 000000000000..52eed328ce99 --- /dev/null +++ b/drivers/gpio/gpio-104-idi-48.c @@ -0,0 +1,343 @@ +/* + * GPIO driver for the ACCES 104-IDI-48 family + * Copyright (C) 2015 William Breathitt Gray + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2, as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ +#include <linux/bitops.h> +#include <linux/device.h> +#include <linux/errno.h> +#include <linux/gpio/driver.h> +#include <linux/io.h> +#include <linux/ioport.h> +#include <linux/interrupt.h> +#include <linux/irqdesc.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> + +static unsigned idi_48_base; +module_param(idi_48_base, uint, 0); +MODULE_PARM_DESC(idi_48_base, "ACCES 104-IDI-48 base address"); +static unsigned idi_48_irq; +module_param(idi_48_irq, uint, 0); +MODULE_PARM_DESC(idi_48_irq, "ACCES 104-IDI-48 interrupt line number"); + +/** + * struct idi_48_gpio - GPIO device private data structure + * @chip: instance of the gpio_chip + * @lock: synchronization lock to prevent I/O race conditions + * @ack_lock: synchronization lock to prevent IRQ handler race conditions + * @irq_mask: input bits affected by interrupts + * @base: base port address of the GPIO device + * @extent: extent of port address region of the GPIO device + * @irq: Interrupt line number + * @cos_enb: Change-Of-State IRQ enable boundaries mask + */ +struct idi_48_gpio { + struct gpio_chip chip; + spinlock_t lock; + spinlock_t ack_lock; + unsigned char irq_mask[6]; + unsigned base; + unsigned extent; + unsigned irq; + unsigned char cos_enb; +}; + +static int idi_48_gpio_get_direction(struct gpio_chip *chip, unsigned offset) +{ + return 1; +} + +static int idi_48_gpio_direction_input(struct gpio_chip *chip, unsigned offset) +{ + return 0; +} + +static int idi_48_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip); + unsigned i; + const unsigned register_offset[6] = { 0, 1, 2, 4, 5, 6 }; + unsigned base_offset; + unsigned mask; + + for (i = 0; i < 48; i += 8) + if (offset < i + 8) { + base_offset = register_offset[i / 8]; + mask = BIT(offset - i); + + return !!(inb(idi48gpio->base + base_offset) & mask); + } + + /* The following line should never execute since offset < 48 */ + return 0; +} + +static void idi_48_irq_ack(struct irq_data *data) +{ +} + +static void idi_48_irq_mask(struct irq_data *data) +{ + struct gpio_chip *chip = irq_data_get_irq_chip_data(data); + struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip); + const unsigned offset = irqd_to_hwirq(data); + unsigned i; + unsigned mask; + unsigned boundary; + unsigned long flags; + + for (i = 0; i < 48; i += 8) + if (offset < i + 8) { + mask = BIT(offset - i); + boundary = i / 8; + + idi48gpio->irq_mask[boundary] &= ~mask; + + if (!idi48gpio->irq_mask[boundary]) { + idi48gpio->cos_enb &= ~BIT(boundary); + + spin_lock_irqsave(&idi48gpio->lock, flags); + + outb(idi48gpio->cos_enb, idi48gpio->base + 7); + + spin_unlock_irqrestore(&idi48gpio->lock, flags); + } + + return; + } +} + +static void idi_48_irq_unmask(struct irq_data *data) +{ + struct gpio_chip *chip = irq_data_get_irq_chip_data(data); + struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip); + const unsigned offset = irqd_to_hwirq(data); + unsigned i; + unsigned mask; + unsigned boundary; + unsigned prev_irq_mask; + unsigned long flags; + + for (i = 0; i < 48; i += 8) + if (offset < i + 8) { + mask = BIT(offset - i); + boundary = i / 8; + prev_irq_mask = idi48gpio->irq_mask[boundary]; + + idi48gpio->irq_mask[boundary] |= mask; + + if (!prev_irq_mask) { + idi48gpio->cos_enb |= BIT(boundary); + + spin_lock_irqsave(&idi48gpio->lock, flags); + + outb(idi48gpio->cos_enb, idi48gpio->base + 7); + + spin_unlock_irqrestore(&idi48gpio->lock, flags); + } + + return; + } +} + +static int idi_48_irq_set_type(struct irq_data *data, unsigned flow_type) +{ + /* The only valid irq types are none and both-edges */ + if (flow_type != IRQ_TYPE_NONE && + (flow_type & IRQ_TYPE_EDGE_BOTH) != IRQ_TYPE_EDGE_BOTH) + return -EINVAL; + + return 0; +} + +static struct irq_chip idi_48_irqchip = { + .name = "104-idi-48", + .irq_ack = idi_48_irq_ack, + .irq_mask = idi_48_irq_mask, + .irq_unmask = idi_48_irq_unmask, + .irq_set_type = idi_48_irq_set_type +}; + +static irqreturn_t idi_48_irq_handler(int irq, void *dev_id) +{ + struct idi_48_gpio *const idi48gpio = dev_id; + unsigned long cos_status; + unsigned long boundary; + unsigned long irq_mask; + unsigned long bit_num; + unsigned long gpio; + struct gpio_chip *const chip = &idi48gpio->chip; + + spin_lock(&idi48gpio->ack_lock); + + spin_lock(&idi48gpio->lock); + + cos_status = inb(idi48gpio->base + 7); + + spin_unlock(&idi48gpio->lock); + + /* IRQ Status (bit 6) is active low (0 = IRQ generated by device) */ + if (cos_status & BIT(6)) { + spin_unlock(&idi48gpio->ack_lock); + return IRQ_NONE; + } + + /* Bit 0-5 indicate which Change-Of-State boundary triggered the IRQ */ + cos_status &= 0x3F; + + for_each_set_bit(boundary, &cos_status, 6) { + irq_mask = idi48gpio->irq_mask[boundary]; + + for_each_set_bit(bit_num, &irq_mask, 8) { + gpio = bit_num + boundary * 8; + + generic_handle_irq(irq_find_mapping(chip->irqdomain, + gpio)); + } + } + + spin_unlock(&idi48gpio->ack_lock); + + return IRQ_HANDLED; +} + +static int __init idi_48_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct idi_48_gpio *idi48gpio; + const unsigned base = idi_48_base; + const unsigned extent = 8; + const char *const name = dev_name(dev); + int err; + const unsigned irq = idi_48_irq; + + idi48gpio = devm_kzalloc(dev, sizeof(*idi48gpio), GFP_KERNEL); + if (!idi48gpio) + return -ENOMEM; + + if (!request_region(base, extent, name)) { + dev_err(dev, "Unable to lock %s port addresses (0x%X-0x%X)\n", + name, base, base + extent); + err = -EBUSY; + goto err_lock_io_port; + } + + idi48gpio->chip.label = name; + idi48gpio->chip.parent = dev; + idi48gpio->chip.owner = THIS_MODULE; + idi48gpio->chip.base = -1; + idi48gpio->chip.ngpio = 48; + idi48gpio->chip.get_direction = idi_48_gpio_get_direction; + idi48gpio->chip.direction_input = idi_48_gpio_direction_input; + idi48gpio->chip.get = idi_48_gpio_get; + idi48gpio->base = base; + idi48gpio->extent = extent; + idi48gpio->irq = irq; + + spin_lock_init(&idi48gpio->lock); + + dev_set_drvdata(dev, idi48gpio); + + err = gpiochip_add_data(&idi48gpio->chip, idi48gpio); + if (err) { + dev_err(dev, "GPIO registering failed (%d)\n", err); + goto err_gpio_register; + } + + /* Disable IRQ by default */ + outb(0, base + 7); + inb(base + 7); + + err = gpiochip_irqchip_add(&idi48gpio->chip, &idi_48_irqchip, 0, + handle_edge_irq, IRQ_TYPE_NONE); + if (err) { + dev_err(dev, "Could not add irqchip (%d)\n", err); + goto err_gpiochip_irqchip_add; + } + + err = request_irq(irq, idi_48_irq_handler, 0, name, idi48gpio); + if (err) { + dev_err(dev, "IRQ handler registering failed (%d)\n", err); + goto err_request_irq; + } + + return 0; + +err_request_irq: +err_gpiochip_irqchip_add: + gpiochip_remove(&idi48gpio->chip); +err_gpio_register: + release_region(base, extent); +err_lock_io_port: + return err; +} + +static int idi_48_remove(struct platform_device *pdev) +{ + struct idi_48_gpio *const idi48gpio = platform_get_drvdata(pdev); + + free_irq(idi48gpio->irq, idi48gpio); + gpiochip_remove(&idi48gpio->chip); + release_region(idi48gpio->base, idi48gpio->extent); + + return 0; +} + +static struct platform_device *idi_48_device; + +static struct platform_driver idi_48_driver = { + .driver = { + .name = "104-idi-48" + }, + .remove = idi_48_remove +}; + +static void __exit idi_48_exit(void) +{ + platform_device_unregister(idi_48_device); + platform_driver_unregister(&idi_48_driver); +} + +static int __init idi_48_init(void) +{ + int err; + + idi_48_device = platform_device_alloc(idi_48_driver.driver.name, -1); + if (!idi_48_device) + return -ENOMEM; + + err = platform_device_add(idi_48_device); + if (err) + goto err_platform_device; + + err = platform_driver_probe(&idi_48_driver, idi_48_probe); + if (err) + goto err_platform_driver; + + return 0; + +err_platform_driver: + platform_device_del(idi_48_device); +err_platform_device: + platform_device_put(idi_48_device); + return err; +} + +module_init(idi_48_init); +module_exit(idi_48_exit); + +MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>"); +MODULE_DESCRIPTION("ACCES 104-IDI-48 GPIO driver"); +MODULE_LICENSE("GPL"); |