[mirror_ubuntu-hirsute-kernel.git] / drivers / gpio / pca953x.c

/*
 *  pca953x.c - 4/8/16 bit I/O ports
 *
 *  Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com>
 *  Copyright (C) 2007 Marvell International Ltd.
 *
 *  Derived from drivers/i2c/chips/pca9539.c
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; version 2 of the License.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/i2c/pca953x.h>

#include <asm/gpio.h>

#define PCA953X_INPUT          0
#define PCA953X_OUTPUT         1
#define PCA953X_INVERT         2
#define PCA953X_DIRECTION      3

/* This is temporary - in 2.6.26 i2c_driver_data should replace it. */
struct pca953x_desc {
	char		name[I2C_NAME_SIZE];
	unsigned long	driver_data;
};

static const struct pca953x_desc pca953x_descs[] = {
	{ "pca9534", 8, },
	{ "pca9535", 16, },
	{ "pca9536", 4, },
	{ "pca9537", 4, },
	{ "pca9538", 8, },
	{ "pca9539", 16, },
	/* REVISIT several pca955x parts should work here too */
};

struct pca953x_chip {
	unsigned gpio_start;
	uint16_t reg_output;
	uint16_t reg_direction;

	struct i2c_client *client;
	struct gpio_chip gpio_chip;
};

/* NOTE:  we can't currently rely on fault codes to come from SMBus
 * calls, so we map all errors to EIO here and return zero otherwise.
 */
static int pca953x_write_reg(struct pca953x_chip *chip, int reg, uint16_t val)
{
	int ret;

	if (chip->gpio_chip.ngpio <= 8)
		ret = i2c_smbus_write_byte_data(chip->client, reg, val);
	else
		ret = i2c_smbus_write_word_data(chip->client, reg << 1, val);

	if (ret < 0) {
		dev_err(&chip->client->dev, "failed writing register\n");
		return -EIO;
	}

	return 0;
}

static int pca953x_read_reg(struct pca953x_chip *chip, int reg, uint16_t *val)
{
	int ret;

	if (chip->gpio_chip.ngpio <= 8)
		ret = i2c_smbus_read_byte_data(chip->client, reg);
	else
		ret = i2c_smbus_read_word_data(chip->client, reg << 1);

	if (ret < 0) {
		dev_err(&chip->client->dev, "failed reading register\n");
		return -EIO;
	}

	*val = (uint16_t)ret;
	return 0;
}

static int pca953x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
{
	struct pca953x_chip *chip;
	uint16_t reg_val;
	int ret;

	chip = container_of(gc, struct pca953x_chip, gpio_chip);

	reg_val = chip->reg_direction | (1u << off);
	ret = pca953x_write_reg(chip, PCA953X_DIRECTION, reg_val);
	if (ret)
		return ret;

	chip->reg_direction = reg_val;
	return 0;
}

static int pca953x_gpio_direction_output(struct gpio_chip *gc,
		unsigned off, int val)
{
	struct pca953x_chip *chip;
	uint16_t reg_val;
	int ret;

	chip = container_of(gc, struct pca953x_chip, gpio_chip);

	/* set output level */
	if (val)
		reg_val = chip->reg_output | (1u << off);
	else
		reg_val = chip->reg_output & ~(1u << off);

	ret = pca953x_write_reg(chip, PCA953X_OUTPUT, reg_val);
	if (ret)
		return ret;

	chip->reg_output = reg_val;

	/* then direction */
	reg_val = chip->reg_direction & ~(1u << off);
	ret = pca953x_write_reg(chip, PCA953X_DIRECTION, reg_val);
	if (ret)
		return ret;

	chip->reg_direction = reg_val;
	return 0;
}

static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off)
{
	struct pca953x_chip *chip;
	uint16_t reg_val;
	int ret;

	chip = container_of(gc, struct pca953x_chip, gpio_chip);

	ret = pca953x_read_reg(chip, PCA953X_INPUT, &reg_val);
	if (ret < 0) {
		/* NOTE:  diagnostic already emitted; that's all we should
		 * do unless gpio_*_value_cansleep() calls become different
		 * from their nonsleeping siblings (and report faults).
		 */
		return 0;
	}

	return (reg_val & (1u << off)) ? 1 : 0;
}

static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
{
	struct pca953x_chip *chip;
	uint16_t reg_val;
	int ret;

	chip = container_of(gc, struct pca953x_chip, gpio_chip);

	if (val)
		reg_val = chip->reg_output | (1u << off);
	else
		reg_val = chip->reg_output & ~(1u << off);

	ret = pca953x_write_reg(chip, PCA953X_OUTPUT, reg_val);
	if (ret)
		return;

	chip->reg_output = reg_val;
}

static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)
{
	struct gpio_chip *gc;

	gc = &chip->gpio_chip;

	gc->direction_input  = pca953x_gpio_direction_input;
	gc->direction_output = pca953x_gpio_direction_output;
	gc->get = pca953x_gpio_get_value;
	gc->set = pca953x_gpio_set_value;

	gc->base = chip->gpio_start;
	gc->ngpio = gpios;
	gc->label = chip->client->name;
}

static int __devinit pca953x_probe(struct i2c_client *client)
{
	struct pca953x_platform_data *pdata;
	struct pca953x_chip *chip;
	int ret, i;
	const struct pca953x_desc *id = NULL;

	pdata = client->dev.platform_data;
	if (pdata == NULL)
		return -ENODEV;

	/* this loop vanishes when we get i2c_device_id */
	for (i = 0; i < ARRAY_SIZE(pca953x_descs); i++)
		if (!strcmp(pca953x_descs[i].name, client->name)) {
			id = pca953x_descs + i;
			break;
		}
	if (!id)
		return -ENODEV;

	chip = kzalloc(sizeof(struct pca953x_chip), GFP_KERNEL);
	if (chip == NULL)
		return -ENOMEM;

	chip->client = client;

	chip->gpio_start = pdata->gpio_base;

	/* initialize cached registers from their original values.
	 * we can't share this chip with another i2c master.
	 */
	pca953x_setup_gpio(chip, id->driver_data);

	ret = pca953x_read_reg(chip, PCA953X_OUTPUT, &chip->reg_output);
	if (ret)
		goto out_failed;

	ret = pca953x_read_reg(chip, PCA953X_DIRECTION, &chip->reg_direction);
	if (ret)
		goto out_failed;

	/* set platform specific polarity inversion */
	ret = pca953x_write_reg(chip, PCA953X_INVERT, pdata->invert);
	if (ret)
		goto out_failed;


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

	if (pdata->setup) {
		ret = pdata->setup(client, chip->gpio_chip.base,
				chip->gpio_chip.ngpio, pdata->context);
		if (ret < 0)
			dev_warn(&client->dev, "setup failed, %d\n", ret);
	}

	i2c_set_clientdata(client, chip);
	return 0;

out_failed:
	kfree(chip);
	return ret;
}

static int pca953x_remove(struct i2c_client *client)
{
	struct pca953x_platform_data *pdata = client->dev.platform_data;
	struct pca953x_chip *chip = i2c_get_clientdata(client);
	int ret = 0;

	if (pdata->teardown) {
		ret = pdata->teardown(client, chip->gpio_chip.base,
				chip->gpio_chip.ngpio, pdata->context);
		if (ret < 0) {
			dev_err(&client->dev, "%s failed, %d\n",
					"teardown", ret);
			return ret;
		}
	}

	ret = gpiochip_remove(&chip->gpio_chip);
	if (ret) {
		dev_err(&client->dev, "%s failed, %d\n",
				"gpiochip_remove()", ret);
		return ret;
	}

	kfree(chip);
	return 0;
}

static struct i2c_driver pca953x_driver = {
	.driver = {
		.name	= "pca953x",
	},
	.probe		= pca953x_probe,
	.remove		= pca953x_remove,
};

static int __init pca953x_init(void)
{
	return i2c_add_driver(&pca953x_driver);
}
module_init(pca953x_init);

static void __exit pca953x_exit(void)
{
	i2c_del_driver(&pca953x_driver);
}
module_exit(pca953x_exit);

MODULE_AUTHOR("eric miao <eric.miao@marvell.com>");
MODULE_DESCRIPTION("GPIO expander driver for PCA953x");
MODULE_LICENSE("GPL");
Commit	Line	Data
9e60fdcf	1	/*
f5e8ff48	2	* pca953x.c - 4/8/16 bit I/O ports
9e60fdcf	3	*
	4	* Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com>
	5	* Copyright (C) 2007 Marvell International Ltd.
	6	*
	7	* Derived from drivers/i2c/chips/pca9539.c
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License as published by
	11	* the Free Software Foundation; version 2 of the License.
	12	*/
	13
	14	#include <linux/module.h>
	15	#include <linux/init.h>
	16	#include <linux/i2c.h>
d1c057e3	17	#include <linux/i2c/pca953x.h>
9e60fdcf	18
	19	#include <asm/gpio.h>
	20
f5e8ff48 GL	21	#define PCA953X_INPUT 0
	22	#define PCA953X_OUTPUT 1
	23	#define PCA953X_INVERT 2
	24	#define PCA953X_DIRECTION 3
9e60fdcf	25
f5e8ff48 GL	26	/* This is temporary - in 2.6.26 i2c_driver_data should replace it. */
	27	struct pca953x_desc {
	28	char name[I2C_NAME_SIZE];
	29	unsigned long driver_data;
	30	};
9e60fdcf	31
f5e8ff48 GL	32	static const struct pca953x_desc pca953x_descs[] = {
	33	{ "pca9534", 8, },
	34	{ "pca9535", 16, },
	35	{ "pca9536", 4, },
	36	{ "pca9537", 4, },
	37	{ "pca9538", 8, },
	38	{ "pca9539", 16, },
	39	/* REVISIT several pca955x parts should work here too */
	40	};
9e60fdcf	41
f3dc3630	42	struct pca953x_chip {
9e60fdcf	43	unsigned gpio_start;
	44	uint16_t reg_output;
	45	uint16_t reg_direction;
	46
	47	struct i2c_client *client;
	48	struct gpio_chip gpio_chip;
	49	};
	50
	51	/* NOTE: we can't currently rely on fault codes to come from SMBus
	52	* calls, so we map all errors to EIO here and return zero otherwise.
	53	*/
f3dc3630	54	static int pca953x_write_reg(struct pca953x_chip *chip, int reg, uint16_t val)
9e60fdcf	55	{
f5e8ff48 GL	56	int ret;
	57
	58	if (chip->gpio_chip.ngpio <= 8)
	59	ret = i2c_smbus_write_byte_data(chip->client, reg, val);
9e60fdcf	60	else
f5e8ff48 GL	61	ret = i2c_smbus_write_word_data(chip->client, reg << 1, val);
	62
	63	if (ret < 0) {
	64	dev_err(&chip->client->dev, "failed writing register\n");
	65	return -EIO;
	66	}
	67
	68	return 0;
9e60fdcf	69	}
9e60fdcf	70
f3dc3630	71	static int pca953x_read_reg(struct pca953x_chip chip, int reg, uint16_t val)
9e60fdcf	72	{
	73	int ret;
	74
f5e8ff48 GL	75	if (chip->gpio_chip.ngpio <= 8)
	76	ret = i2c_smbus_read_byte_data(chip->client, reg);
	77	else
	78	ret = i2c_smbus_read_word_data(chip->client, reg << 1);
	79
9e60fdcf	80	if (ret < 0) {
	81	dev_err(&chip->client->dev, "failed reading register\n");
	82	return -EIO;
	83	}
	84
	85	*val = (uint16_t)ret;
	86	return 0;
	87	}
	88
f3dc3630	89	static int pca953x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
9e60fdcf	90	{
f3dc3630	91	struct pca953x_chip *chip;
9e60fdcf	92	uint16_t reg_val;
	93	int ret;
	94
f3dc3630	95	chip = container_of(gc, struct pca953x_chip, gpio_chip);
9e60fdcf	96
9e60fdcf	97	reg_val = chip->reg_direction \| (1u << off);
f3dc3630	98	ret = pca953x_write_reg(chip, PCA953X_DIRECTION, reg_val);
9e60fdcf	99	if (ret)
	100	return ret;
	101
	102	chip->reg_direction = reg_val;
	103	return 0;
	104	}
	105
f3dc3630	106	static int pca953x_gpio_direction_output(struct gpio_chip *gc,
9e60fdcf	107	unsigned off, int val)
9e60fdcf	108	{
f3dc3630	109	struct pca953x_chip *chip;
9e60fdcf	110	uint16_t reg_val;
	111	int ret;
	112
f3dc3630	113	chip = container_of(gc, struct pca953x_chip, gpio_chip);
9e60fdcf	114
	115	/* set output level */
	116	if (val)
	117	reg_val = chip->reg_output \| (1u << off);
	118	else
	119	reg_val = chip->reg_output & ~(1u << off);
	120
f3dc3630	121	ret = pca953x_write_reg(chip, PCA953X_OUTPUT, reg_val);
9e60fdcf	122	if (ret)
	123	return ret;
	124
	125	chip->reg_output = reg_val;
	126
	127	/* then direction */
	128	reg_val = chip->reg_direction & ~(1u << off);
f3dc3630	129	ret = pca953x_write_reg(chip, PCA953X_DIRECTION, reg_val);
9e60fdcf	130	if (ret)
	131	return ret;
	132
	133	chip->reg_direction = reg_val;
	134	return 0;
	135	}
	136
f3dc3630	137	static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off)
9e60fdcf	138	{
f3dc3630	139	struct pca953x_chip *chip;
9e60fdcf	140	uint16_t reg_val;
	141	int ret;
	142
f3dc3630	143	chip = container_of(gc, struct pca953x_chip, gpio_chip);
9e60fdcf	144
f3dc3630	145	ret = pca953x_read_reg(chip, PCA953X_INPUT, &reg_val);
9e60fdcf	146	if (ret < 0) {
	147	/* NOTE: diagnostic already emitted; that's all we should
	148	* do unless gpio_*_value_cansleep() calls become different
	149	* from their nonsleeping siblings (and report faults).
	150	*/
	151	return 0;
	152	}
	153
	154	return (reg_val & (1u << off)) ? 1 : 0;
	155	}
	156
f3dc3630	157	static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
9e60fdcf	158	{
f3dc3630	159	struct pca953x_chip *chip;
9e60fdcf	160	uint16_t reg_val;
	161	int ret;
	162
f3dc3630	163	chip = container_of(gc, struct pca953x_chip, gpio_chip);
9e60fdcf	164
	165	if (val)
	166	reg_val = chip->reg_output \| (1u << off);
	167	else
	168	reg_val = chip->reg_output & ~(1u << off);
	169
f3dc3630	170	ret = pca953x_write_reg(chip, PCA953X_OUTPUT, reg_val);
9e60fdcf	171	if (ret)
	172	return;
	173
	174	chip->reg_output = reg_val;
	175	}
	176
f5e8ff48	177	static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)
9e60fdcf	178	{
	179	struct gpio_chip *gc;
	180
	181	gc = &chip->gpio_chip;
	182
f3dc3630 GL	183	gc->direction_input = pca953x_gpio_direction_input;
	184	gc->direction_output = pca953x_gpio_direction_output;
	185	gc->get = pca953x_gpio_get_value;
	186	gc->set = pca953x_gpio_set_value;
9e60fdcf	187
9e60fdcf	188	gc->base = chip->gpio_start;
f5e8ff48 GL	189	gc->ngpio = gpios;
f5e8ff48 GL	190	gc->label = chip->client->name;
9e60fdcf	191	}
9e60fdcf	192
f3dc3630	193	static int __devinit pca953x_probe(struct i2c_client *client)
9e60fdcf	194	{
f3dc3630 GL	195	struct pca953x_platform_data *pdata;
f3dc3630 GL	196	struct pca953x_chip *chip;
f5e8ff48 GL	197	int ret, i;
f5e8ff48 GL	198	const struct pca953x_desc *id = NULL;
9e60fdcf	199
	200	pdata = client->dev.platform_data;
	201	if (pdata == NULL)
	202	return -ENODEV;
	203
f5e8ff48 GL	204	/* this loop vanishes when we get i2c_device_id */
	205	for (i = 0; i < ARRAY_SIZE(pca953x_descs); i++)
	206	if (!strcmp(pca953x_descs[i].name, client->name)) {
	207	id = pca953x_descs + i;
	208	break;
	209	}
	210	if (!id)
	211	return -ENODEV;
	212
f3dc3630	213	chip = kzalloc(sizeof(struct pca953x_chip), GFP_KERNEL);
9e60fdcf	214	if (chip == NULL)
	215	return -ENOMEM;
	216
	217	chip->client = client;
	218
	219	chip->gpio_start = pdata->gpio_base;
	220
	221	/* initialize cached registers from their original values.
	222	* we can't share this chip with another i2c master.
	223	*/
f5e8ff48 GL	224	pca953x_setup_gpio(chip, id->driver_data);
f5e8ff48 GL	225
f3dc3630	226	ret = pca953x_read_reg(chip, PCA953X_OUTPUT, &chip->reg_output);
9e60fdcf	227	if (ret)
	228	goto out_failed;
	229
f3dc3630	230	ret = pca953x_read_reg(chip, PCA953X_DIRECTION, &chip->reg_direction);
9e60fdcf	231	if (ret)
	232	goto out_failed;
	233
	234	/* set platform specific polarity inversion */
f3dc3630	235	ret = pca953x_write_reg(chip, PCA953X_INVERT, pdata->invert);
9e60fdcf	236	if (ret)
	237	goto out_failed;
	238
f5e8ff48 GL	239
f5e8ff48 GL	240	ret = gpiochip_add(&chip->gpio_chip);
9e60fdcf	241	if (ret)
	242	goto out_failed;
	243
	244	if (pdata->setup) {
	245	ret = pdata->setup(client, chip->gpio_chip.base,
	246	chip->gpio_chip.ngpio, pdata->context);
	247	if (ret < 0)
	248	dev_warn(&client->dev, "setup failed, %d\n", ret);
	249	}
	250
	251	i2c_set_clientdata(client, chip);
	252	return 0;
	253
	254	out_failed:
	255	kfree(chip);
	256	return ret;
	257	}
	258
f3dc3630	259	static int pca953x_remove(struct i2c_client *client)
9e60fdcf	260	{
f3dc3630 GL	261	struct pca953x_platform_data *pdata = client->dev.platform_data;
f3dc3630 GL	262	struct pca953x_chip *chip = i2c_get_clientdata(client);
9e60fdcf	263	int ret = 0;
	264
	265	if (pdata->teardown) {
	266	ret = pdata->teardown(client, chip->gpio_chip.base,
	267	chip->gpio_chip.ngpio, pdata->context);
	268	if (ret < 0) {
	269	dev_err(&client->dev, "%s failed, %d\n",
	270	"teardown", ret);
	271	return ret;
	272	}
	273	}
	274
	275	ret = gpiochip_remove(&chip->gpio_chip);
	276	if (ret) {
	277	dev_err(&client->dev, "%s failed, %d\n",
	278	"gpiochip_remove()", ret);
	279	return ret;
	280	}
	281
	282	kfree(chip);
	283	return 0;
	284	}
	285
f3dc3630	286	static struct i2c_driver pca953x_driver = {
9e60fdcf	287	.driver = {
f3dc3630	288	.name = "pca953x",
9e60fdcf	289	},
f3dc3630 GL	290	.probe = pca953x_probe,
f3dc3630 GL	291	.remove = pca953x_remove,
9e60fdcf	292	};
9e60fdcf	293
f3dc3630	294	static int __init pca953x_init(void)
9e60fdcf	295	{
f3dc3630	296	return i2c_add_driver(&pca953x_driver);
9e60fdcf	297	}
f3dc3630	298	module_init(pca953x_init);
9e60fdcf	299
f3dc3630	300	static void __exit pca953x_exit(void)
9e60fdcf	301	{
f3dc3630	302	i2c_del_driver(&pca953x_driver);
9e60fdcf	303	}
f3dc3630	304	module_exit(pca953x_exit);
9e60fdcf	305
9e60fdcf	306	MODULE_AUTHOR("eric miao <eric.miao@marvell.com>");
f3dc3630	307	MODULE_DESCRIPTION("GPIO expander driver for PCA953x");
9e60fdcf	308	MODULE_LICENSE("GPL");