Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Driver for PCA9570 I2C GPO expander
4 *
5 * Copyright (C) 2020 Sungbo Eo <mans0n@gorani.run>
6 *
7 * Based on gpio-tpic2810.c
8 * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/
9 * Andrew F. Davis <afd@ti.com>
10 */
11
12#include <linux/bits.h>
13#include <linux/cleanup.h>
14#include <linux/device/devres.h>
15#include <linux/errno.h>
16#include <linux/gpio/driver.h>
17#include <linux/i2c.h>
18#include <linux/module.h>
19#include <linux/mutex.h>
20#include <linux/property.h>
21#include <linux/types.h>
22
23#define SLG7XL45106_GPO_REG 0xDB
24
25/**
26 * struct pca9570_chip_data - GPIO platformdata
27 * @ngpio: no of gpios
28 * @command: Command to be sent
29 */
30struct pca9570_chip_data {
31 u16 ngpio;
32 u32 command;
33};
34
35/**
36 * struct pca9570 - GPIO driver data
37 * @chip: GPIO controller chip
38 * @chip_data: GPIO controller platform data
39 * @lock: Protects write sequences
40 * @out: Buffer for device register
41 */
42struct pca9570 {
43 struct gpio_chip chip;
44 const struct pca9570_chip_data *chip_data;
45 struct mutex lock;
46 u8 out;
47};
48
49static int pca9570_read(struct pca9570 *gpio, u8 *value)
50{
51 struct i2c_client *client = to_i2c_client(gpio->chip.parent);
52 int ret;
53
54 if (gpio->chip_data->command != 0)
55 ret = i2c_smbus_read_byte_data(client, gpio->chip_data->command);
56 else
57 ret = i2c_smbus_read_byte(client);
58
59 if (ret < 0)
60 return ret;
61
62 *value = ret;
63 return 0;
64}
65
66static int pca9570_write(struct pca9570 *gpio, u8 value)
67{
68 struct i2c_client *client = to_i2c_client(gpio->chip.parent);
69
70 if (gpio->chip_data->command != 0)
71 return i2c_smbus_write_byte_data(client, gpio->chip_data->command, value);
72
73 return i2c_smbus_write_byte(client, value);
74}
75
76static int pca9570_get_direction(struct gpio_chip *chip,
77 unsigned offset)
78{
79 /* This device always output */
80 return GPIO_LINE_DIRECTION_OUT;
81}
82
83static int pca9570_get(struct gpio_chip *chip, unsigned offset)
84{
85 struct pca9570 *gpio = gpiochip_get_data(chip);
86 u8 buffer;
87 int ret;
88
89 ret = pca9570_read(gpio, &buffer);
90 if (ret)
91 return ret;
92
93 return !!(buffer & BIT(offset));
94}
95
96static int pca9570_set(struct gpio_chip *chip, unsigned int offset, int value)
97{
98 struct pca9570 *gpio = gpiochip_get_data(chip);
99 u8 buffer;
100 int ret;
101
102 guard(mutex)(&gpio->lock);
103
104 buffer = gpio->out;
105 if (value)
106 buffer |= BIT(offset);
107 else
108 buffer &= ~BIT(offset);
109
110 ret = pca9570_write(gpio, buffer);
111 if (ret)
112 return ret;
113
114 gpio->out = buffer;
115
116 return 0;
117}
118
119static int pca9570_probe(struct i2c_client *client)
120{
121 struct device *dev = &client->dev;
122 struct pca9570 *gpio;
123 int ret;
124
125 gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL);
126 if (!gpio)
127 return -ENOMEM;
128
129 gpio->chip.label = client->name;
130 gpio->chip.parent = &client->dev;
131 gpio->chip.owner = THIS_MODULE;
132 gpio->chip.get_direction = pca9570_get_direction;
133 gpio->chip.get = pca9570_get;
134 gpio->chip.set = pca9570_set;
135 gpio->chip.base = -1;
136 gpio->chip_data = device_get_match_data(&client->dev);
137 gpio->chip.ngpio = gpio->chip_data->ngpio;
138 gpio->chip.can_sleep = true;
139
140 ret = devm_mutex_init(dev, &gpio->lock);
141 if (ret)
142 return ret;
143
144 /* Read the current output level */
145 pca9570_read(gpio, &gpio->out);
146
147 i2c_set_clientdata(client, gpio);
148
149 return devm_gpiochip_add_data(&client->dev, &gpio->chip, gpio);
150}
151
152static const struct pca9570_chip_data pca9570_gpio = {
153 .ngpio = 4,
154};
155
156static const struct pca9570_chip_data pca9571_gpio = {
157 .ngpio = 8,
158};
159
160static const struct pca9570_chip_data slg7xl45106_gpio = {
161 .ngpio = 8,
162 .command = SLG7XL45106_GPO_REG,
163};
164
165static const struct i2c_device_id pca9570_id_table[] = {
166 { "pca9570", (kernel_ulong_t)&pca9570_gpio},
167 { "pca9571", (kernel_ulong_t)&pca9571_gpio },
168 { "slg7xl45106", (kernel_ulong_t)&slg7xl45106_gpio },
169 { /* sentinel */ }
170};
171MODULE_DEVICE_TABLE(i2c, pca9570_id_table);
172
173static const struct of_device_id pca9570_of_match_table[] = {
174 { .compatible = "dlg,slg7xl45106", .data = &slg7xl45106_gpio},
175 { .compatible = "nxp,pca9570", .data = &pca9570_gpio },
176 { .compatible = "nxp,pca9571", .data = &pca9571_gpio },
177 { /* sentinel */ }
178};
179MODULE_DEVICE_TABLE(of, pca9570_of_match_table);
180
181static struct i2c_driver pca9570_driver = {
182 .driver = {
183 .name = "pca9570",
184 .of_match_table = pca9570_of_match_table,
185 },
186 .probe = pca9570_probe,
187 .id_table = pca9570_id_table,
188};
189module_i2c_driver(pca9570_driver);
190
191MODULE_AUTHOR("Sungbo Eo <mans0n@gorani.run>");
192MODULE_DESCRIPTION("GPIO expander driver for PCA9570");
193MODULE_LICENSE("GPL v2");