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