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 */
21 struct tpic2810 {
22 struct gpio_chip chip;
23 struct i2c_client *client;
24 u8 buffer;
25 struct mutex lock;
26 };
27
28 static void tpic2810_set(struct gpio_chip *chip, unsigned offset, int value);
29
tpic2810_get_direction(struct gpio_chip * chip,unsigned offset)30 static 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
tpic2810_direction_input(struct gpio_chip * chip,unsigned offset)37 static int tpic2810_direction_input(struct gpio_chip *chip,
38 unsigned offset)
39 {
40 /* This device is output only */
41 return -EINVAL;
42 }
43
tpic2810_direction_output(struct gpio_chip * chip,unsigned offset,int value)44 static 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
tpic2810_set_mask_bits(struct gpio_chip * chip,u8 mask,u8 bits)52 static 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
tpic2810_set(struct gpio_chip * chip,unsigned offset,int value)71 static 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
tpic2810_set_multiple(struct gpio_chip * chip,unsigned long * mask,unsigned long * bits)76 static 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
82 static 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
95 static const struct of_device_id tpic2810_of_match_table[] = {
96 { .compatible = "ti,tpic2810" },
97 { /* sentinel */ }
98 };
99 MODULE_DEVICE_TABLE(of, tpic2810_of_match_table);
100
tpic2810_probe(struct i2c_client * client)101 static 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
119 static const struct i2c_device_id tpic2810_id_table[] = {
120 { "tpic2810", },
121 { /* sentinel */ }
122 };
123 MODULE_DEVICE_TABLE(i2c, tpic2810_id_table);
124
125 static 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 };
133 module_i2c_driver(tpic2810_driver);
134
135 MODULE_AUTHOR("Andrew Davis <afd@ti.com>");
136 MODULE_DESCRIPTION("TPIC2810 8-Bit LED Driver GPIO Driver");
137 MODULE_LICENSE("GPL v2");
138