[linux.git] / drivers / gpio / gpio-74x164.c

/*
 *  74Hx164 - Generic serial-in/parallel-out 8-bits shift register GPIO driver
 *
 *  Copyright (C) 2010 Gabor Juhos <[email protected]>
 *  Copyright (C) 2010 Miguel Gaio <[email protected]>
 *
 *  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.
 */

#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/spi/spi.h>
#include <linux/spi/74x164.h>
#include <linux/gpio.h>
#include <linux/slab.h>
#include <linux/module.h>

struct gen_74x164_chip {
	struct spi_device	*spi;
	struct gpio_chip	gpio_chip;
	struct mutex		lock;
	u8			port_config;
};

static struct gen_74x164_chip *gpio_to_74x164_chip(struct gpio_chip *gc)
{
	return container_of(gc, struct gen_74x164_chip, gpio_chip);
}

static int __gen_74x164_write_config(struct gen_74x164_chip *chip)
{
	return spi_write(chip->spi,
			 &chip->port_config, sizeof(chip->port_config));
}

static int gen_74x164_get_value(struct gpio_chip *gc, unsigned offset)
{
	struct gen_74x164_chip *chip = gpio_to_74x164_chip(gc);
	int ret;

	mutex_lock(&chip->lock);
	ret = (chip->port_config >> offset) & 0x1;
	mutex_unlock(&chip->lock);

	return ret;
}

static void gen_74x164_set_value(struct gpio_chip *gc,
		unsigned offset, int val)
{
	struct gen_74x164_chip *chip = gpio_to_74x164_chip(gc);

	mutex_lock(&chip->lock);
	if (val)
		chip->port_config |= (1 << offset);
	else
		chip->port_config &= ~(1 << offset);

	__gen_74x164_write_config(chip);
	mutex_unlock(&chip->lock);
}

static int gen_74x164_direction_output(struct gpio_chip *gc,
		unsigned offset, int val)
{
	gen_74x164_set_value(gc, offset, val);
	return 0;
}

static int __devinit gen_74x164_probe(struct spi_device *spi)
{
	struct gen_74x164_chip *chip;
	struct gen_74x164_chip_platform_data *pdata;
	int ret;

	pdata = spi->dev.platform_data;
	if (!pdata || !pdata->base) {
		dev_dbg(&spi->dev, "incorrect or missing platform data\n");
		return -EINVAL;
	}

	/*
	 * bits_per_word cannot be configured in platform data
	 */
	spi->bits_per_word = 8;

	ret = spi_setup(spi);
	if (ret < 0)
		return ret;

	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
	if (!chip)
		return -ENOMEM;

	mutex_init(&chip->lock);

	dev_set_drvdata(&spi->dev, chip);

	chip->spi = spi;

	chip->gpio_chip.label = spi->modalias;
	chip->gpio_chip.direction_output = gen_74x164_direction_output;
	chip->gpio_chip.get = gen_74x164_get_value;
	chip->gpio_chip.set = gen_74x164_set_value;
	chip->gpio_chip.base = pdata->base;
	chip->gpio_chip.ngpio = 8;
	chip->gpio_chip.can_sleep = 1;
	chip->gpio_chip.dev = &spi->dev;
	chip->gpio_chip.owner = THIS_MODULE;

	ret = __gen_74x164_write_config(chip);
	if (ret) {
		dev_err(&spi->dev, "Failed writing: %d\n", ret);
		goto exit_destroy;
	}

	ret = gpiochip_add(&chip->gpio_chip);
	if (ret)
		goto exit_destroy;

	return ret;

exit_destroy:
	dev_set_drvdata(&spi->dev, NULL);
	mutex_destroy(&chip->lock);
	kfree(chip);
	return ret;
}

static int __devexit gen_74x164_remove(struct spi_device *spi)
{
	struct gen_74x164_chip *chip;
	int ret;

	chip = dev_get_drvdata(&spi->dev);
	if (chip == NULL)
		return -ENODEV;

	dev_set_drvdata(&spi->dev, NULL);

	ret = gpiochip_remove(&chip->gpio_chip);
	if (!ret) {
		mutex_destroy(&chip->lock);
		kfree(chip);
	} else
		dev_err(&spi->dev, "Failed to remove the GPIO controller: %d\n",
				ret);

	return ret;
}

static struct spi_driver gen_74x164_driver = {
	.driver = {
		.name		= "74x164",
		.owner		= THIS_MODULE,
	},
	.probe		= gen_74x164_probe,
	.remove		= __devexit_p(gen_74x164_remove),
};

static int __init gen_74x164_init(void)
{
	return spi_register_driver(&gen_74x164_driver);
}
subsys_initcall(gen_74x164_init);

static void __exit gen_74x164_exit(void)
{
	spi_unregister_driver(&gen_74x164_driver);
}
module_exit(gen_74x164_exit);

MODULE_AUTHOR("Gabor Juhos <[email protected]>");
MODULE_AUTHOR("Miguel Gaio <[email protected]>");
MODULE_DESCRIPTION("GPIO expander driver for 74X164 8-bits shift register");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
ead6db08 MG	1	/*
	2	* 74Hx164 - Generic serial-in/parallel-out 8-bits shift register GPIO driver
	3	*
	4	* Copyright (C) 2010 Gabor Juhos <[email protected]>
	5	* Copyright (C) 2010 Miguel Gaio <[email protected]>
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*/
	11
	12	#include <linux/init.h>
	13	#include <linux/mutex.h>
	14	#include <linux/spi/spi.h>
	15	#include <linux/spi/74x164.h>
	16	#include <linux/gpio.h>
	17	#include <linux/slab.h>
bb207ef1	18	#include <linux/module.h>
ead6db08	19
ead6db08 MG	20	struct gen_74x164_chip {
	21	struct spi_device *spi;
	22	struct gpio_chip gpio_chip;
	23	struct mutex lock;
	24	u8 port_config;
	25	};
	26
12610be3	27	static struct gen_74x164_chip gpio_to_74x164_chip(struct gpio_chip gc)
ead6db08 MG	28	{
	29	return container_of(gc, struct gen_74x164_chip, gpio_chip);
	30	}
	31
	32	static int __gen_74x164_write_config(struct gen_74x164_chip *chip)
	33	{
	34	return spi_write(chip->spi,
	35	&chip->port_config, sizeof(chip->port_config));
	36	}
	37
ead6db08 MG	38	static int gen_74x164_get_value(struct gpio_chip *gc, unsigned offset)
ead6db08 MG	39	{
12610be3	40	struct gen_74x164_chip *chip = gpio_to_74x164_chip(gc);
ead6db08 MG	41	int ret;
	42
	43	mutex_lock(&chip->lock);
	44	ret = (chip->port_config >> offset) & 0x1;
	45	mutex_unlock(&chip->lock);
	46
	47	return ret;
	48	}
	49
	50	static void gen_74x164_set_value(struct gpio_chip *gc,
	51	unsigned offset, int val)
	52	{
12610be3	53	struct gen_74x164_chip *chip = gpio_to_74x164_chip(gc);
ead6db08 MG	54
	55	mutex_lock(&chip->lock);
	56	if (val)
	57	chip->port_config \|= (1 << offset);
	58	else
	59	chip->port_config &= ~(1 << offset);
	60
	61	__gen_74x164_write_config(chip);
	62	mutex_unlock(&chip->lock);
	63	}
	64
a3cc68c3 HS	65	static int gen_74x164_direction_output(struct gpio_chip *gc,
	66	unsigned offset, int val)
	67	{
	68	gen_74x164_set_value(gc, offset, val);
	69	return 0;
	70	}
	71
ead6db08 MG	72	static int __devinit gen_74x164_probe(struct spi_device *spi)
	73	{
	74	struct gen_74x164_chip *chip;
	75	struct gen_74x164_chip_platform_data *pdata;
	76	int ret;
	77
	78	pdata = spi->dev.platform_data;
	79	if (!pdata \|\| !pdata->base) {
	80	dev_dbg(&spi->dev, "incorrect or missing platform data\n");
	81	return -EINVAL;
	82	}
	83
	84	/*
	85	* bits_per_word cannot be configured in platform data
	86	*/
	87	spi->bits_per_word = 8;
	88
	89	ret = spi_setup(spi);
	90	if (ret < 0)
	91	return ret;
	92
	93	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
	94	if (!chip)
	95	return -ENOMEM;
	96
	97	mutex_init(&chip->lock);
	98
	99	dev_set_drvdata(&spi->dev, chip);
	100
	101	chip->spi = spi;
	102
a3cc68c3 HS	103	chip->gpio_chip.label = spi->modalias;
a3cc68c3 HS	104	chip->gpio_chip.direction_output = gen_74x164_direction_output;
ead6db08 MG	105	chip->gpio_chip.get = gen_74x164_get_value;
	106	chip->gpio_chip.set = gen_74x164_set_value;
	107	chip->gpio_chip.base = pdata->base;
a3cc68c3	108	chip->gpio_chip.ngpio = 8;
ead6db08 MG	109	chip->gpio_chip.can_sleep = 1;
	110	chip->gpio_chip.dev = &spi->dev;
	111	chip->gpio_chip.owner = THIS_MODULE;
	112
	113	ret = __gen_74x164_write_config(chip);
	114	if (ret) {
	115	dev_err(&spi->dev, "Failed writing: %d\n", ret);
	116	goto exit_destroy;
	117	}
	118
	119	ret = gpiochip_add(&chip->gpio_chip);
	120	if (ret)
	121	goto exit_destroy;
	122
	123	return ret;
	124
	125	exit_destroy:
	126	dev_set_drvdata(&spi->dev, NULL);
	127	mutex_destroy(&chip->lock);
	128	kfree(chip);
	129	return ret;
	130	}
	131
fc1599f7	132	static int __devexit gen_74x164_remove(struct spi_device *spi)
ead6db08 MG	133	{
	134	struct gen_74x164_chip *chip;
	135	int ret;
	136
	137	chip = dev_get_drvdata(&spi->dev);
	138	if (chip == NULL)
	139	return -ENODEV;
	140
	141	dev_set_drvdata(&spi->dev, NULL);
	142
	143	ret = gpiochip_remove(&chip->gpio_chip);
	144	if (!ret) {
	145	mutex_destroy(&chip->lock);
	146	kfree(chip);
	147	} else
	148	dev_err(&spi->dev, "Failed to remove the GPIO controller: %d\n",
	149	ret);
	150
	151	return ret;
	152	}
	153
	154	static struct spi_driver gen_74x164_driver = {
	155	.driver = {
a3cc68c3	156	.name = "74x164",
ead6db08 MG	157	.owner = THIS_MODULE,
	158	},
	159	.probe = gen_74x164_probe,
	160	.remove = __devexit_p(gen_74x164_remove),
	161	};
	162
	163	static int __init gen_74x164_init(void)
	164	{
	165	return spi_register_driver(&gen_74x164_driver);
	166	}
	167	subsys_initcall(gen_74x164_init);
	168
	169	static void __exit gen_74x164_exit(void)
	170	{
	171	spi_unregister_driver(&gen_74x164_driver);
	172	}
	173	module_exit(gen_74x164_exit);
	174
	175	MODULE_AUTHOR("Gabor Juhos <[email protected]>");
	176	MODULE_AUTHOR("Miguel Gaio <[email protected]>");
	177	MODULE_DESCRIPTION("GPIO expander driver for 74X164 8-bits shift register");
	178	MODULE_LICENSE("GPL v2");