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 void tpic2810_set(struct gpio_chip *chip, unsigned 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_input(struct gpio_chip *chip,
38				    unsigned offset)
39{
40	/* This device is output only */
41	return -EINVAL;
42}
43
44static int tpic2810_direction_output(struct gpio_chip *chip,
45				     unsigned offset, int value)
46{
47	/* This device always output */
48	tpic2810_set(chip, offset, value);
49	return 0;
50}
51
52static void tpic2810_set_mask_bits(struct gpio_chip *chip, u8 mask, u8 bits)
53{
54	struct tpic2810 *gpio = gpiochip_get_data(chip);
55	u8 buffer;
56	int err;
57
58	mutex_lock(&gpio->lock);
59
60	buffer = gpio->buffer & ~mask;
61	buffer |= (mask & bits);
62
63	err = i2c_smbus_write_byte_data(gpio->client, TPIC2810_WS_COMMAND,
64					buffer);
65	if (!err)
66		gpio->buffer = buffer;
67
68	mutex_unlock(&gpio->lock);
69}
70
71static void tpic2810_set(struct gpio_chip *chip, unsigned offset, int value)
72{
73	tpic2810_set_mask_bits(chip, BIT(offset), value ? BIT(offset) : 0);
74}
75
76static void tpic2810_set_multiple(struct gpio_chip *chip, unsigned long *mask,
77				  unsigned long *bits)
78{
79	tpic2810_set_mask_bits(chip, *mask, *bits);
80}
81
82static const struct gpio_chip template_chip = {
83	.label			= "tpic2810",
84	.owner			= THIS_MODULE,
85	.get_direction		= tpic2810_get_direction,
86	.direction_input	= tpic2810_direction_input,
87	.direction_output	= tpic2810_direction_output,
88	.set			= tpic2810_set,
89	.set_multiple		= tpic2810_set_multiple,
90	.base			= -1,
91	.ngpio			= 8,
92	.can_sleep		= true,
93};
94
95static const struct of_device_id tpic2810_of_match_table[] = {
96	{ .compatible = "ti,tpic2810" },
97	{ /* sentinel */ }
98};
99MODULE_DEVICE_TABLE(of, tpic2810_of_match_table);
100
101static int tpic2810_probe(struct i2c_client *client)
102{
103	struct tpic2810 *gpio;
104
105	gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL);
106	if (!gpio)
107		return -ENOMEM;
108
109	gpio->chip = template_chip;
110	gpio->chip.parent = &client->dev;
111
112	gpio->client = client;
113
114	mutex_init(&gpio->lock);
115
116	return devm_gpiochip_add_data(&client->dev, &gpio->chip, gpio);
117}
118
119static const struct i2c_device_id tpic2810_id_table[] = {
120	{ "tpic2810", },
121	{ /* sentinel */ }
122};
123MODULE_DEVICE_TABLE(i2c, tpic2810_id_table);
124
125static struct i2c_driver tpic2810_driver = {
126	.driver = {
127		.name = "tpic2810",
128		.of_match_table = tpic2810_of_match_table,
129	},
130	.probe = tpic2810_probe,
131	.id_table = tpic2810_id_table,
132};
133module_i2c_driver(tpic2810_driver);
134
135MODULE_AUTHOR("Andrew Davis <afd@ti.com>");
136MODULE_DESCRIPTION("TPIC2810 8-Bit LED Driver GPIO Driver");
137MODULE_LICENSE("GPL v2");
138