drivers/gpio/pca953x.c - linux - Git at Google

 /*
  *  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->can_sleep = 1;

 	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");
	/*
	* 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->can_sleep = 1;

	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");