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Commit 1ceacea2 authored by William Breathitt Gray's avatar William Breathitt Gray Committed by Linus Walleij
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gpio: Add GPIO support for the ACCES 104-IDIO-16 



The ACCES 104-IDIO-16 family of PC/104 utility boards feature 16
optically isolated inputs and 16 optically isolated FET solid state
outputs. This driver provides GPIO support for these 32 channels of
digital I/O. Change-of-State detection interrupts are not supported.

GPIO 0-15 correspond to digital outputs 0-15, while GPIO 16-31
correspond to digital inputs 0-15. The base port address for the device
may be set via the idio_16_base module parameter.

Signed-off-by: default avatarWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 6057d40f

drivers/gpio/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -689,6 +689,16 @@ config GPIO_SX150X 


endmenu



menu "ISA GPIO drivers"



config GPIO_104_IDIO_16

	tristate "ACCES 104-IDIO-16 GPIO support"

	depends on X86

	help

	  Enables GPIO support for the ACCES 104-IDIO-16 family.



endmenu



menu "MFD GPIO expanders"



config GPIO_ADP5520

drivers/gpio/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ obj-$(CONFIG_GPIO_ACPI) += gpiolib-acpi.o 
# Device drivers. Generally keep list sorted alphabetically

obj-$(CONFIG_GPIO_GENERIC)	+= gpio-generic.o



obj-$(CONFIG_GPIO_104_IDIO_16)	+= gpio-104-idio-16.o

obj-$(CONFIG_GPIO_74X164)	+= gpio-74x164.o

obj-$(CONFIG_GPIO_74XX_MMIO)	+= gpio-74xx-mmio.o

obj-$(CONFIG_GPIO_ADNP)		+= gpio-adnp.o

drivers/gpio/gpio-104-idio-16.c

0 → 100644
+216 −0
Original line number Diff line number Diff line 
/*

 * GPIO driver for the ACCES 104-IDIO-16 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/device.h>

#include <linux/errno.h>

#include <linux/gpio/driver.h>

#include <linux/io.h>

#include <linux/ioport.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/platform_device.h>

#include <linux/spinlock.h>



static unsigned idio_16_base;

module_param(idio_16_base, uint, 0);

MODULE_PARM_DESC(idio_16_base, "ACCES 104-IDIO-16 base address");



/**

 * struct idio_16_gpio - GPIO device private data structure

 * @chip:	instance of the gpio_chip

 * @lock:	synchronization lock to prevent gpio_set race conditions

 * @base:	base port address of the GPIO device

 * @extent:	extent of port address region of the GPIO device

 * @out_state:	output bits state

 */

struct idio_16_gpio {

	struct gpio_chip chip;

	spinlock_t lock;

	unsigned base;

	unsigned extent;

	unsigned out_state;

};



static int idio_16_gpio_get_direction(struct gpio_chip *chip, unsigned offset)

{

	if (offset > 15)

		return 1;



	return 0;

}



static int idio_16_gpio_direction_input(struct gpio_chip *chip, unsigned offset)

{

	return 0;

}



static int idio_16_gpio_direction_output(struct gpio_chip *chip,

	unsigned offset, int value)

{

	chip->set(chip, offset, value);

	return 0;

}



static struct idio_16_gpio *to_idio16gpio(struct gpio_chip *gc)

{

	return container_of(gc, struct idio_16_gpio, chip);

}



static int idio_16_gpio_get(struct gpio_chip *chip, unsigned offset)

{

	struct idio_16_gpio *const idio16gpio = to_idio16gpio(chip);

	const unsigned BIT_MASK = 1U << (offset-16);



	if (offset < 16)

		return -EINVAL;



	if (offset < 24)

		return !!(inb(idio16gpio->base + 1) & BIT_MASK);



	return !!(inb(idio16gpio->base + 5) & (BIT_MASK>>8));

}



static void idio_16_gpio_set(struct gpio_chip *chip, unsigned offset, int value)

{

	struct idio_16_gpio *const idio16gpio = to_idio16gpio(chip);

	const unsigned BIT_MASK = 1U << offset;

	unsigned long flags;



	if (offset > 15)

		return;



	spin_lock_irqsave(&idio16gpio->lock, flags);



	if (value)

		idio16gpio->out_state |= BIT_MASK;

	else

		idio16gpio->out_state &= ~BIT_MASK;



	if (offset > 7)

		outb(idio16gpio->out_state >> 8, idio16gpio->base + 4);

	else

		outb(idio16gpio->out_state, idio16gpio->base);



	spin_unlock_irqrestore(&idio16gpio->lock, flags);

}



static int __init idio_16_probe(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;

	struct idio_16_gpio *idio16gpio;

	int err;



	const unsigned BASE = idio_16_base;

	const unsigned EXTENT = 8;

	const char *const NAME = dev_name(dev);



	idio16gpio = devm_kzalloc(dev, sizeof(*idio16gpio), GFP_KERNEL);

	if (!idio16gpio)

		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;

	}



	idio16gpio->chip.label = NAME;

	idio16gpio->chip.dev = dev;

	idio16gpio->chip.owner = THIS_MODULE;

	idio16gpio->chip.base = -1;

	idio16gpio->chip.ngpio = 32;

	idio16gpio->chip.get_direction = idio_16_gpio_get_direction;

	idio16gpio->chip.direction_input = idio_16_gpio_direction_input;

	idio16gpio->chip.direction_output = idio_16_gpio_direction_output;

	idio16gpio->chip.get = idio_16_gpio_get;

	idio16gpio->chip.set = idio_16_gpio_set;

	idio16gpio->base = BASE;

	idio16gpio->extent = EXTENT;

	idio16gpio->out_state = 0xFFFF;



	spin_lock_init(&idio16gpio->lock);



	dev_set_drvdata(dev, idio16gpio);



	err = gpiochip_add(&idio16gpio->chip);

	if (err) {

		dev_err(dev, "GPIO registering failed (%d)\n", err);

		goto err_gpio_register;

	}



	return 0;



err_gpio_register:

	release_region(BASE, EXTENT);

err_lock_io_port:

	return err;

}



static int idio_16_remove(struct platform_device *pdev)

{

	struct idio_16_gpio *const idio16gpio = platform_get_drvdata(pdev);



	gpiochip_remove(&idio16gpio->chip);

	release_region(idio16gpio->base, idio16gpio->extent);



	return 0;

}



static struct platform_device *idio_16_device;



static struct platform_driver idio_16_driver = {

	.driver = {

		.name = "104-idio-16"

	},

	.remove = idio_16_remove

};



static void __exit idio_16_exit(void)

{

	platform_device_unregister(idio_16_device);

	platform_driver_unregister(&idio_16_driver);

}



static int __init idio_16_init(void)

{

	int err;



	idio_16_device = platform_device_alloc(idio_16_driver.driver.name, -1);

	if (!idio_16_device)

		return -ENOMEM;



	err = platform_device_add(idio_16_device);

	if (err)

		goto err_platform_device;



	err = platform_driver_probe(&idio_16_driver, idio_16_probe);

	if (err)

		goto err_platform_driver;



	return 0;



err_platform_driver:

	platform_device_del(idio_16_device);

err_platform_device:

	platform_device_put(idio_16_device);

	return err;

}



module_init(idio_16_init);

module_exit(idio_16_exit);



MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");

MODULE_DESCRIPTION("ACCES 104-IDIO-16 GPIO driver");

MODULE_LICENSE("GPL");