xref: /linux/drivers/gpio/gpio-tpic2810.c (revision cdd5b5a9761fd66d17586e4f4ba6588c70e640ea)
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