1/*
2 * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/
3 *	Andrew F. Davis <afd@ti.com>
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
10 * kind, whether expressed or implied; without even the implied warranty
11 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License version 2 for more details.
13 */
14
15#include <linux/gpio/driver.h>
16#include <linux/i2c.h>
17#include <linux/module.h>
18#include <linux/mutex.h>
19
20#define TPIC2810_WS_COMMAND 0x44
21
22/**
23 * struct tpic2810 - GPIO driver data
24 * @chip: GPIO controller chip
25 * @client: I2C device pointer
26 * @buffer: Buffer for device register
27 * @lock: Protects write sequences
28 */
29struct tpic2810 {
30	struct gpio_chip chip;
31	struct i2c_client *client;
32	u8 buffer;
33	struct mutex lock;
34};
35
36static void tpic2810_set(struct gpio_chip *chip, unsigned offset, int value);
37
38static int tpic2810_get_direction(struct gpio_chip *chip,
39				  unsigned offset)
40{
41	/* This device always output */
42	return GPIO_LINE_DIRECTION_OUT;
43}
44
45static int tpic2810_direction_input(struct gpio_chip *chip,
46				    unsigned offset)
47{
48	/* This device is output only */
49	return -EINVAL;
50}
51
52static int tpic2810_direction_output(struct gpio_chip *chip,
53				     unsigned offset, int value)
54{
55	/* This device always output */
56	tpic2810_set(chip, offset, value);
57	return 0;
58}
59
60static void tpic2810_set_mask_bits(struct gpio_chip *chip, u8 mask, u8 bits)
61{
62	struct tpic2810 *gpio = gpiochip_get_data(chip);
63	u8 buffer;
64	int err;
65
66	mutex_lock(&gpio->lock);
67
68	buffer = gpio->buffer & ~mask;
69	buffer |= (mask & bits);
70
71	err = i2c_smbus_write_byte_data(gpio->client, TPIC2810_WS_COMMAND,
72					buffer);
73	if (!err)
74		gpio->buffer = buffer;
75
76	mutex_unlock(&gpio->lock);
77}
78
79static void tpic2810_set(struct gpio_chip *chip, unsigned offset, int value)
80{
81	tpic2810_set_mask_bits(chip, BIT(offset), value ? BIT(offset) : 0);
82}
83
84static void tpic2810_set_multiple(struct gpio_chip *chip, unsigned long *mask,
85				  unsigned long *bits)
86{
87	tpic2810_set_mask_bits(chip, *mask, *bits);
88}
89
90static const struct gpio_chip template_chip = {
91	.label			= "tpic2810",
92	.owner			= THIS_MODULE,
93	.get_direction		= tpic2810_get_direction,
94	.direction_input	= tpic2810_direction_input,
95	.direction_output	= tpic2810_direction_output,
96	.set			= tpic2810_set,
97	.set_multiple		= tpic2810_set_multiple,
98	.base			= -1,
99	.ngpio			= 8,
100	.can_sleep		= true,
101};
102
103static const struct of_device_id tpic2810_of_match_table[] = {
104	{ .compatible = "ti,tpic2810" },
105	{ /* sentinel */ }
106};
107MODULE_DEVICE_TABLE(of, tpic2810_of_match_table);
108
109static int tpic2810_probe(struct i2c_client *client,
110			  const struct i2c_device_id *id)
111{
112	struct tpic2810 *gpio;
113	int ret;
114
115	gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL);
116	if (!gpio)
117		return -ENOMEM;
118
119	i2c_set_clientdata(client, gpio);
120
121	gpio->chip = template_chip;
122	gpio->chip.parent = &client->dev;
123
124	gpio->client = client;
125
126	mutex_init(&gpio->lock);
127
128	ret = gpiochip_add_data(&gpio->chip, gpio);
129	if (ret < 0) {
130		dev_err(&client->dev, "Unable to register gpiochip\n");
131		return ret;
132	}
133
134	return 0;
135}
136
137static int tpic2810_remove(struct i2c_client *client)
138{
139	struct tpic2810 *gpio = i2c_get_clientdata(client);
140
141	gpiochip_remove(&gpio->chip);
142
143	return 0;
144}
145
146static const struct i2c_device_id tpic2810_id_table[] = {
147	{ "tpic2810", },
148	{ /* sentinel */ }
149};
150MODULE_DEVICE_TABLE(i2c, tpic2810_id_table);
151
152static struct i2c_driver tpic2810_driver = {
153	.driver = {
154		.name = "tpic2810",
155		.of_match_table = tpic2810_of_match_table,
156	},
157	.probe = tpic2810_probe,
158	.remove = tpic2810_remove,
159	.id_table = tpic2810_id_table,
160};
161module_i2c_driver(tpic2810_driver);
162
163MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
164MODULE_DESCRIPTION("TPIC2810 8-Bit LED Driver GPIO Driver");
165MODULE_LICENSE("GPL v2");
166