gpio-tpic2810.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (C) 2015-2023 Texas Instruments Incorporated - https://www.ti.com/
  4 *	Andrew Davis <afd@ti.com>
  5 */
  6
  7#include <linux/gpio/driver.h>
  8#include <linux/i2c.h>
  9#include <linux/module.h>
 10#include <linux/mutex.h>
 11
 12#define TPIC2810_WS_COMMAND 0x44
 13
 14/**
 15 * struct tpic2810 - GPIO driver data
 16 * @chip: GPIO controller chip
 17 * @client: I2C device pointer
 18 * @buffer: Buffer for device register
 19 * @lock: Protects write sequences
 20 */
 21struct tpic2810 {
 22	struct gpio_chip chip;
 23	struct i2c_client *client;
 24	u8 buffer;
 25	struct mutex lock;
 26};
 27
 28static int tpic2810_set(struct gpio_chip *chip, unsigned int offset, int value);
 29
 30static int tpic2810_get_direction(struct gpio_chip *chip,
 31				  unsigned offset)
 32{
 33	/* This device always output */
 34	return GPIO_LINE_DIRECTION_OUT;
 35}
 36
 37static int tpic2810_direction_output(struct gpio_chip *chip,
 38				     unsigned offset, int value)
 39{
 40	/* This device always output */
 41	return tpic2810_set(chip, offset, value);
 42}
 43
 44static void tpic2810_set_mask_bits(struct gpio_chip *chip, u8 mask, u8 bits)
 45{
 46	struct tpic2810 *gpio = gpiochip_get_data(chip);
 47	u8 buffer;
 48	int err;
 49
 50	mutex_lock(&gpio->lock);
 51
 52	buffer = gpio->buffer & ~mask;
 53	buffer |= (mask & bits);
 54
 55	err = i2c_smbus_write_byte_data(gpio->client, TPIC2810_WS_COMMAND,
 56					buffer);
 57	if (!err)
 58		gpio->buffer = buffer;
 59
 60	mutex_unlock(&gpio->lock);
 61}
 62
 63static int tpic2810_set(struct gpio_chip *chip, unsigned int offset, int value)
 64{
 65	tpic2810_set_mask_bits(chip, BIT(offset), value ? BIT(offset) : 0);
 66
 67	return 0;
 68}
 69
 70static int tpic2810_set_multiple(struct gpio_chip *chip, unsigned long *mask,
 71				 unsigned long *bits)
 72{
 73	tpic2810_set_mask_bits(chip, *mask, *bits);
 74
 75	return 0;
 76}
 77
 78static const struct gpio_chip template_chip = {
 79	.label			= "tpic2810",
 80	.owner			= THIS_MODULE,
 81	.get_direction		= tpic2810_get_direction,
 82	.direction_output	= tpic2810_direction_output,
 83	.set			= tpic2810_set,
 84	.set_multiple		= tpic2810_set_multiple,
 85	.base			= -1,
 86	.ngpio			= 8,
 87	.can_sleep		= true,
 88};
 89
 90static const struct of_device_id tpic2810_of_match_table[] = {
 91	{ .compatible = "ti,tpic2810" },
 92	{ /* sentinel */ }
 93};
 94MODULE_DEVICE_TABLE(of, tpic2810_of_match_table);
 95
 96static int tpic2810_probe(struct i2c_client *client)
 97{
 98	struct tpic2810 *gpio;
 99
100	gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL);
101	if (!gpio)
102		return -ENOMEM;
103
104	gpio->chip = template_chip;
105	gpio->chip.parent = &client->dev;
106
107	gpio->client = client;
108
109	mutex_init(&gpio->lock);
110
111	return devm_gpiochip_add_data(&client->dev, &gpio->chip, gpio);
112}
113
114static const struct i2c_device_id tpic2810_id_table[] = {
115	{ "tpic2810", },
116	{ /* sentinel */ }
117};
118MODULE_DEVICE_TABLE(i2c, tpic2810_id_table);
119
120static struct i2c_driver tpic2810_driver = {
121	.driver = {
122		.name = "tpic2810",
123		.of_match_table = tpic2810_of_match_table,
124	},
125	.probe = tpic2810_probe,
126	.id_table = tpic2810_id_table,
127};
128module_i2c_driver(tpic2810_driver);
129
130MODULE_AUTHOR("Andrew Davis <afd@ti.com>");
131MODULE_DESCRIPTION("TPIC2810 8-Bit LED Driver GPIO Driver");
132MODULE_LICENSE("GPL v2");