|  | /* | 
|  | *  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/gpio.h> | 
|  | #include <linux/i2c.h> | 
|  | #include <linux/i2c/pca953x.h> | 
|  | #ifdef CONFIG_OF_GPIO | 
|  | #include <linux/of_platform.h> | 
|  | #include <linux/of_gpio.h> | 
|  | #endif | 
|  |  | 
|  | #define PCA953X_INPUT          0 | 
|  | #define PCA953X_OUTPUT         1 | 
|  | #define PCA953X_INVERT         2 | 
|  | #define PCA953X_DIRECTION      3 | 
|  |  | 
|  | static const struct i2c_device_id pca953x_id[] = { | 
|  | { "pca9534", 8, }, | 
|  | { "pca9535", 16, }, | 
|  | { "pca9536", 4, }, | 
|  | { "pca9537", 4, }, | 
|  | { "pca9538", 8, }, | 
|  | { "pca9539", 16, }, | 
|  | { "pca9554", 8, }, | 
|  | { "pca9555", 16, }, | 
|  | { "pca9556", 8, }, | 
|  | { "pca9557", 8, }, | 
|  |  | 
|  | { "max7310", 8, }, | 
|  | { "max7315", 8, }, | 
|  | { "pca6107", 8, }, | 
|  | { "tca6408", 8, }, | 
|  | { "tca6416", 16, }, | 
|  | /* NYET:  { "tca6424", 24, }, */ | 
|  | { } | 
|  | }; | 
|  | MODULE_DEVICE_TABLE(i2c, pca953x_id); | 
|  |  | 
|  | struct pca953x_chip { | 
|  | unsigned gpio_start; | 
|  | uint16_t reg_output; | 
|  | uint16_t reg_direction; | 
|  |  | 
|  | struct i2c_client *client; | 
|  | struct pca953x_platform_data *dyn_pdata; | 
|  | struct gpio_chip gpio_chip; | 
|  | char **names; | 
|  | }; | 
|  |  | 
|  | 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 ret; | 
|  | } | 
|  |  | 
|  | 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 ret; | 
|  | } | 
|  |  | 
|  | *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, ®_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; | 
|  | gc->dev = &chip->client->dev; | 
|  | gc->owner = THIS_MODULE; | 
|  | gc->names = chip->names; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Handlers for alternative sources of platform_data | 
|  | */ | 
|  | #ifdef CONFIG_OF_GPIO | 
|  | /* | 
|  | * Translate OpenFirmware node properties into platform_data | 
|  | */ | 
|  | static struct pca953x_platform_data * | 
|  | pca953x_get_alt_pdata(struct i2c_client *client) | 
|  | { | 
|  | struct pca953x_platform_data *pdata; | 
|  | struct device_node *node; | 
|  | const uint16_t *val; | 
|  |  | 
|  | node = dev_archdata_get_node(&client->dev.archdata); | 
|  | if (node == NULL) | 
|  | return NULL; | 
|  |  | 
|  | pdata = kzalloc(sizeof(struct pca953x_platform_data), GFP_KERNEL); | 
|  | if (pdata == NULL) { | 
|  | dev_err(&client->dev, "Unable to allocate platform_data\n"); | 
|  | return NULL; | 
|  | } | 
|  |  | 
|  | pdata->gpio_base = -1; | 
|  | val = of_get_property(node, "linux,gpio-base", NULL); | 
|  | if (val) { | 
|  | if (*val < 0) | 
|  | dev_warn(&client->dev, | 
|  | "invalid gpio-base in device tree\n"); | 
|  | else | 
|  | pdata->gpio_base = *val; | 
|  | } | 
|  |  | 
|  | val = of_get_property(node, "polarity", NULL); | 
|  | if (val) | 
|  | pdata->invert = *val; | 
|  |  | 
|  | return pdata; | 
|  | } | 
|  | #else | 
|  | static struct pca953x_platform_data * | 
|  | pca953x_get_alt_pdata(struct i2c_client *client) | 
|  | { | 
|  | return NULL; | 
|  | } | 
|  | #endif | 
|  |  | 
|  | static int __devinit pca953x_probe(struct i2c_client *client, | 
|  | const struct i2c_device_id *id) | 
|  | { | 
|  | struct pca953x_platform_data *pdata; | 
|  | struct pca953x_chip *chip; | 
|  | int ret; | 
|  |  | 
|  | chip = kzalloc(sizeof(struct pca953x_chip), GFP_KERNEL); | 
|  | if (chip == NULL) | 
|  | return -ENOMEM; | 
|  |  | 
|  | pdata = client->dev.platform_data; | 
|  | if (pdata == NULL) { | 
|  | pdata = pca953x_get_alt_pdata(client); | 
|  | /* | 
|  | * Unlike normal platform_data, this is allocated | 
|  | * dynamically and must be freed in the driver | 
|  | */ | 
|  | chip->dyn_pdata = pdata; | 
|  | } | 
|  |  | 
|  | if (pdata == NULL) { | 
|  | dev_dbg(&client->dev, "no platform data\n"); | 
|  | ret = -EINVAL; | 
|  | goto out_failed; | 
|  | } | 
|  |  | 
|  | chip->client = client; | 
|  |  | 
|  | chip->gpio_start = pdata->gpio_base; | 
|  |  | 
|  | chip->names = pdata->names; | 
|  |  | 
|  | /* 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->dyn_pdata); | 
|  | 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->dyn_pdata); | 
|  | kfree(chip); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static struct i2c_driver pca953x_driver = { | 
|  | .driver = { | 
|  | .name	= "pca953x", | 
|  | }, | 
|  | .probe		= pca953x_probe, | 
|  | .remove		= pca953x_remove, | 
|  | .id_table	= pca953x_id, | 
|  | }; | 
|  |  | 
|  | static int __init pca953x_init(void) | 
|  | { | 
|  | return i2c_add_driver(&pca953x_driver); | 
|  | } | 
|  | /* register after i2c postcore initcall and before | 
|  | * subsys initcalls that may rely on these GPIOs | 
|  | */ | 
|  | subsys_initcall(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"); |