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