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/*
* Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/
* Andrew F. Davis <afd@ti.com>
*
* 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 "as is" WITHOUT ANY WARRANTY of any
* kind, whether expressed or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License version 2 for more details.
*/
#include <linux/gpio/driver.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/mutex.h>
#define TPIC2810_WS_COMMAND 0x44
/**
* struct tpic2810 - GPIO driver data
* @chip: GPIO controller chip
* @client: I2C device pointer
* @buffer: Buffer for device register
* @lock: Protects write sequences
*/
struct tpic2810 {
struct gpio_chip chip;
struct i2c_client *client;
u8 buffer;
struct mutex lock;
};
static void tpic2810_set(struct gpio_chip *chip, unsigned offset, int value);
static int tpic2810_get_direction(struct gpio_chip *chip,
unsigned offset)
{
/* This device always output */
return 0;
}
static int tpic2810_direction_input(struct gpio_chip *chip,
unsigned offset)
{
/* This device is output only */
return -EINVAL;
}
static int tpic2810_direction_output(struct gpio_chip *chip,
unsigned offset, int value)
{
/* This device always output */
tpic2810_set(chip, offset, value);
return 0;
}
static void tpic2810_set_mask_bits(struct gpio_chip *chip, u8 mask, u8 bits)
{
struct tpic2810 *gpio = gpiochip_get_data(chip);
u8 buffer;
int err;
mutex_lock(&gpio->lock);
buffer = gpio->buffer & ~mask;
buffer |= (mask & bits);
err = i2c_smbus_write_byte_data(gpio->client, TPIC2810_WS_COMMAND,
buffer);
if (!err)
gpio->buffer = buffer;
mutex_unlock(&gpio->lock);
}
static void tpic2810_set(struct gpio_chip *chip, unsigned offset, int value)
{
tpic2810_set_mask_bits(chip, BIT(offset), value ? BIT(offset) : 0);
}
static void tpic2810_set_multiple(struct gpio_chip *chip, unsigned long *mask,
unsigned long *bits)
{
tpic2810_set_mask_bits(chip, *mask, *bits);
}
static struct gpio_chip template_chip = {
.label = "tpic2810",
.owner = THIS_MODULE,
.get_direction = tpic2810_get_direction,
.direction_input = tpic2810_direction_input,
.direction_output = tpic2810_direction_output,
.set = tpic2810_set,
.set_multiple = tpic2810_set_multiple,
.base = -1,
.ngpio = 8,
.can_sleep = true,
};
static const struct of_device_id tpic2810_of_match_table[] = {
{ .compatible = "ti,tpic2810" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, tpic2810_of_match_table);
static int tpic2810_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct tpic2810 *gpio;
int ret;
gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL);
if (!gpio)
return -ENOMEM;
i2c_set_clientdata(client, gpio);
gpio->chip = template_chip;
gpio->chip.parent = &client->dev;
gpio->client = client;
mutex_init(&gpio->lock);
ret = gpiochip_add_data(&gpio->chip, gpio);
if (ret < 0) {
dev_err(&client->dev, "Unable to register gpiochip\n");
return ret;
}
return 0;
}
static int tpic2810_remove(struct i2c_client *client)
{
struct tpic2810 *gpio = i2c_get_clientdata(client);
gpiochip_remove(&gpio->chip);
return 0;
}
static const struct i2c_device_id tpic2810_id_table[] = {
{ "tpic2810", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(i2c, tpic2810_id_table);
static struct i2c_driver tpic2810_driver = {
.driver = {
.name = "tpic2810",
.of_match_table = tpic2810_of_match_table,
},
.probe = tpic2810_probe,
.remove = tpic2810_remove,
.id_table = tpic2810_id_table,
};
module_i2c_driver(tpic2810_driver);
MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
MODULE_DESCRIPTION("TPIC2810 8-Bit LED Driver GPIO Driver");
MODULE_LICENSE("GPL v2");
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