Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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");