Commit | Line | Data |
---|---|---|
9e60fdcf | 1 | /* |
f5e8ff48 | 2 | * pca953x.c - 4/8/16 bit I/O ports |
9e60fdcf | 3 | * |
4 | * Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com> | |
5 | * Copyright (C) 2007 Marvell International Ltd. | |
6 | * | |
7 | * Derived from drivers/i2c/chips/pca9539.c | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License as published by | |
11 | * the Free Software Foundation; version 2 of the License. | |
12 | */ | |
13 | ||
14 | #include <linux/module.h> | |
15 | #include <linux/init.h> | |
16 | #include <linux/i2c.h> | |
d1c057e3 | 17 | #include <linux/i2c/pca953x.h> |
9e60fdcf | 18 | |
19 | #include <asm/gpio.h> | |
20 | ||
f5e8ff48 GL |
21 | #define PCA953X_INPUT 0 |
22 | #define PCA953X_OUTPUT 1 | |
23 | #define PCA953X_INVERT 2 | |
24 | #define PCA953X_DIRECTION 3 | |
9e60fdcf | 25 | |
f5e8ff48 GL |
26 | /* This is temporary - in 2.6.26 i2c_driver_data should replace it. */ |
27 | struct pca953x_desc { | |
28 | char name[I2C_NAME_SIZE]; | |
29 | unsigned long driver_data; | |
30 | }; | |
9e60fdcf | 31 | |
f5e8ff48 GL |
32 | static const struct pca953x_desc pca953x_descs[] = { |
33 | { "pca9534", 8, }, | |
34 | { "pca9535", 16, }, | |
35 | { "pca9536", 4, }, | |
36 | { "pca9537", 4, }, | |
37 | { "pca9538", 8, }, | |
38 | { "pca9539", 16, }, | |
39 | /* REVISIT several pca955x parts should work here too */ | |
40 | }; | |
9e60fdcf | 41 | |
f3dc3630 | 42 | struct pca953x_chip { |
9e60fdcf | 43 | unsigned gpio_start; |
44 | uint16_t reg_output; | |
45 | uint16_t reg_direction; | |
46 | ||
47 | struct i2c_client *client; | |
48 | struct gpio_chip gpio_chip; | |
49 | }; | |
50 | ||
51 | /* NOTE: we can't currently rely on fault codes to come from SMBus | |
52 | * calls, so we map all errors to EIO here and return zero otherwise. | |
53 | */ | |
f3dc3630 | 54 | static int pca953x_write_reg(struct pca953x_chip *chip, int reg, uint16_t val) |
9e60fdcf | 55 | { |
f5e8ff48 GL |
56 | int ret; |
57 | ||
58 | if (chip->gpio_chip.ngpio <= 8) | |
59 | ret = i2c_smbus_write_byte_data(chip->client, reg, val); | |
9e60fdcf | 60 | else |
f5e8ff48 GL |
61 | ret = i2c_smbus_write_word_data(chip->client, reg << 1, val); |
62 | ||
63 | if (ret < 0) { | |
64 | dev_err(&chip->client->dev, "failed writing register\n"); | |
65 | return -EIO; | |
66 | } | |
67 | ||
68 | return 0; | |
9e60fdcf | 69 | } |
70 | ||
f3dc3630 | 71 | static int pca953x_read_reg(struct pca953x_chip *chip, int reg, uint16_t *val) |
9e60fdcf | 72 | { |
73 | int ret; | |
74 | ||
f5e8ff48 GL |
75 | if (chip->gpio_chip.ngpio <= 8) |
76 | ret = i2c_smbus_read_byte_data(chip->client, reg); | |
77 | else | |
78 | ret = i2c_smbus_read_word_data(chip->client, reg << 1); | |
79 | ||
9e60fdcf | 80 | if (ret < 0) { |
81 | dev_err(&chip->client->dev, "failed reading register\n"); | |
82 | return -EIO; | |
83 | } | |
84 | ||
85 | *val = (uint16_t)ret; | |
86 | return 0; | |
87 | } | |
88 | ||
f3dc3630 | 89 | static int pca953x_gpio_direction_input(struct gpio_chip *gc, unsigned off) |
9e60fdcf | 90 | { |
f3dc3630 | 91 | struct pca953x_chip *chip; |
9e60fdcf | 92 | uint16_t reg_val; |
93 | int ret; | |
94 | ||
f3dc3630 | 95 | chip = container_of(gc, struct pca953x_chip, gpio_chip); |
9e60fdcf | 96 | |
97 | reg_val = chip->reg_direction | (1u << off); | |
f3dc3630 | 98 | ret = pca953x_write_reg(chip, PCA953X_DIRECTION, reg_val); |
9e60fdcf | 99 | if (ret) |
100 | return ret; | |
101 | ||
102 | chip->reg_direction = reg_val; | |
103 | return 0; | |
104 | } | |
105 | ||
f3dc3630 | 106 | static int pca953x_gpio_direction_output(struct gpio_chip *gc, |
9e60fdcf | 107 | unsigned off, int val) |
108 | { | |
f3dc3630 | 109 | struct pca953x_chip *chip; |
9e60fdcf | 110 | uint16_t reg_val; |
111 | int ret; | |
112 | ||
f3dc3630 | 113 | chip = container_of(gc, struct pca953x_chip, gpio_chip); |
9e60fdcf | 114 | |
115 | /* set output level */ | |
116 | if (val) | |
117 | reg_val = chip->reg_output | (1u << off); | |
118 | else | |
119 | reg_val = chip->reg_output & ~(1u << off); | |
120 | ||
f3dc3630 | 121 | ret = pca953x_write_reg(chip, PCA953X_OUTPUT, reg_val); |
9e60fdcf | 122 | if (ret) |
123 | return ret; | |
124 | ||
125 | chip->reg_output = reg_val; | |
126 | ||
127 | /* then direction */ | |
128 | reg_val = chip->reg_direction & ~(1u << off); | |
f3dc3630 | 129 | ret = pca953x_write_reg(chip, PCA953X_DIRECTION, reg_val); |
9e60fdcf | 130 | if (ret) |
131 | return ret; | |
132 | ||
133 | chip->reg_direction = reg_val; | |
134 | return 0; | |
135 | } | |
136 | ||
f3dc3630 | 137 | static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off) |
9e60fdcf | 138 | { |
f3dc3630 | 139 | struct pca953x_chip *chip; |
9e60fdcf | 140 | uint16_t reg_val; |
141 | int ret; | |
142 | ||
f3dc3630 | 143 | chip = container_of(gc, struct pca953x_chip, gpio_chip); |
9e60fdcf | 144 | |
f3dc3630 | 145 | ret = pca953x_read_reg(chip, PCA953X_INPUT, ®_val); |
9e60fdcf | 146 | if (ret < 0) { |
147 | /* NOTE: diagnostic already emitted; that's all we should | |
148 | * do unless gpio_*_value_cansleep() calls become different | |
149 | * from their nonsleeping siblings (and report faults). | |
150 | */ | |
151 | return 0; | |
152 | } | |
153 | ||
154 | return (reg_val & (1u << off)) ? 1 : 0; | |
155 | } | |
156 | ||
f3dc3630 | 157 | static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val) |
9e60fdcf | 158 | { |
f3dc3630 | 159 | struct pca953x_chip *chip; |
9e60fdcf | 160 | uint16_t reg_val; |
161 | int ret; | |
162 | ||
f3dc3630 | 163 | chip = container_of(gc, struct pca953x_chip, gpio_chip); |
9e60fdcf | 164 | |
165 | if (val) | |
166 | reg_val = chip->reg_output | (1u << off); | |
167 | else | |
168 | reg_val = chip->reg_output & ~(1u << off); | |
169 | ||
f3dc3630 | 170 | ret = pca953x_write_reg(chip, PCA953X_OUTPUT, reg_val); |
9e60fdcf | 171 | if (ret) |
172 | return; | |
173 | ||
174 | chip->reg_output = reg_val; | |
175 | } | |
176 | ||
f5e8ff48 | 177 | static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios) |
9e60fdcf | 178 | { |
179 | struct gpio_chip *gc; | |
180 | ||
181 | gc = &chip->gpio_chip; | |
182 | ||
f3dc3630 GL |
183 | gc->direction_input = pca953x_gpio_direction_input; |
184 | gc->direction_output = pca953x_gpio_direction_output; | |
185 | gc->get = pca953x_gpio_get_value; | |
186 | gc->set = pca953x_gpio_set_value; | |
84207805 | 187 | gc->can_sleep = 1; |
9e60fdcf | 188 | |
189 | gc->base = chip->gpio_start; | |
f5e8ff48 GL |
190 | gc->ngpio = gpios; |
191 | gc->label = chip->client->name; | |
9e60fdcf | 192 | } |
193 | ||
f3dc3630 | 194 | static int __devinit pca953x_probe(struct i2c_client *client) |
9e60fdcf | 195 | { |
f3dc3630 GL |
196 | struct pca953x_platform_data *pdata; |
197 | struct pca953x_chip *chip; | |
f5e8ff48 GL |
198 | int ret, i; |
199 | const struct pca953x_desc *id = NULL; | |
9e60fdcf | 200 | |
201 | pdata = client->dev.platform_data; | |
202 | if (pdata == NULL) | |
203 | return -ENODEV; | |
204 | ||
f5e8ff48 GL |
205 | /* this loop vanishes when we get i2c_device_id */ |
206 | for (i = 0; i < ARRAY_SIZE(pca953x_descs); i++) | |
207 | if (!strcmp(pca953x_descs[i].name, client->name)) { | |
208 | id = pca953x_descs + i; | |
209 | break; | |
210 | } | |
211 | if (!id) | |
212 | return -ENODEV; | |
213 | ||
f3dc3630 | 214 | chip = kzalloc(sizeof(struct pca953x_chip), GFP_KERNEL); |
9e60fdcf | 215 | if (chip == NULL) |
216 | return -ENOMEM; | |
217 | ||
218 | chip->client = client; | |
219 | ||
220 | chip->gpio_start = pdata->gpio_base; | |
221 | ||
222 | /* initialize cached registers from their original values. | |
223 | * we can't share this chip with another i2c master. | |
224 | */ | |
f5e8ff48 GL |
225 | pca953x_setup_gpio(chip, id->driver_data); |
226 | ||
f3dc3630 | 227 | ret = pca953x_read_reg(chip, PCA953X_OUTPUT, &chip->reg_output); |
9e60fdcf | 228 | if (ret) |
229 | goto out_failed; | |
230 | ||
f3dc3630 | 231 | ret = pca953x_read_reg(chip, PCA953X_DIRECTION, &chip->reg_direction); |
9e60fdcf | 232 | if (ret) |
233 | goto out_failed; | |
234 | ||
235 | /* set platform specific polarity inversion */ | |
f3dc3630 | 236 | ret = pca953x_write_reg(chip, PCA953X_INVERT, pdata->invert); |
9e60fdcf | 237 | if (ret) |
238 | goto out_failed; | |
239 | ||
f5e8ff48 GL |
240 | |
241 | ret = gpiochip_add(&chip->gpio_chip); | |
9e60fdcf | 242 | if (ret) |
243 | goto out_failed; | |
244 | ||
245 | if (pdata->setup) { | |
246 | ret = pdata->setup(client, chip->gpio_chip.base, | |
247 | chip->gpio_chip.ngpio, pdata->context); | |
248 | if (ret < 0) | |
249 | dev_warn(&client->dev, "setup failed, %d\n", ret); | |
250 | } | |
251 | ||
252 | i2c_set_clientdata(client, chip); | |
253 | return 0; | |
254 | ||
255 | out_failed: | |
256 | kfree(chip); | |
257 | return ret; | |
258 | } | |
259 | ||
f3dc3630 | 260 | static int pca953x_remove(struct i2c_client *client) |
9e60fdcf | 261 | { |
f3dc3630 GL |
262 | struct pca953x_platform_data *pdata = client->dev.platform_data; |
263 | struct pca953x_chip *chip = i2c_get_clientdata(client); | |
9e60fdcf | 264 | int ret = 0; |
265 | ||
266 | if (pdata->teardown) { | |
267 | ret = pdata->teardown(client, chip->gpio_chip.base, | |
268 | chip->gpio_chip.ngpio, pdata->context); | |
269 | if (ret < 0) { | |
270 | dev_err(&client->dev, "%s failed, %d\n", | |
271 | "teardown", ret); | |
272 | return ret; | |
273 | } | |
274 | } | |
275 | ||
276 | ret = gpiochip_remove(&chip->gpio_chip); | |
277 | if (ret) { | |
278 | dev_err(&client->dev, "%s failed, %d\n", | |
279 | "gpiochip_remove()", ret); | |
280 | return ret; | |
281 | } | |
282 | ||
283 | kfree(chip); | |
284 | return 0; | |
285 | } | |
286 | ||
f3dc3630 | 287 | static struct i2c_driver pca953x_driver = { |
9e60fdcf | 288 | .driver = { |
f3dc3630 | 289 | .name = "pca953x", |
9e60fdcf | 290 | }, |
f3dc3630 GL |
291 | .probe = pca953x_probe, |
292 | .remove = pca953x_remove, | |
9e60fdcf | 293 | }; |
294 | ||
f3dc3630 | 295 | static int __init pca953x_init(void) |
9e60fdcf | 296 | { |
f3dc3630 | 297 | return i2c_add_driver(&pca953x_driver); |
9e60fdcf | 298 | } |
f3dc3630 | 299 | module_init(pca953x_init); |
9e60fdcf | 300 | |
f3dc3630 | 301 | static void __exit pca953x_exit(void) |
9e60fdcf | 302 | { |
f3dc3630 | 303 | i2c_del_driver(&pca953x_driver); |
9e60fdcf | 304 | } |
f3dc3630 | 305 | module_exit(pca953x_exit); |
9e60fdcf | 306 | |
307 | MODULE_AUTHOR("eric miao <eric.miao@marvell.com>"); | |
f3dc3630 | 308 | MODULE_DESCRIPTION("GPIO expander driver for PCA953x"); |
9e60fdcf | 309 | MODULE_LICENSE("GPL"); |