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14#include <linux/module.h>
15#include <linux/init.h>
16#include <linux/gpio.h>
17#include <linux/i2c.h>
18#include <linux/i2c/pca953x.h>
19#ifdef CONFIG_OF_GPIO
20#include <linux/of_platform.h>
21#include <linux/of_gpio.h>
22#endif
23
24#define PCA953X_INPUT 0
25#define PCA953X_OUTPUT 1
26#define PCA953X_INVERT 2
27#define PCA953X_DIRECTION 3
28
29static const struct i2c_device_id pca953x_id[] = {
30 { "pca9534", 8, },
31 { "pca9535", 16, },
32 { "pca9536", 4, },
33 { "pca9537", 4, },
34 { "pca9538", 8, },
35 { "pca9539", 16, },
36 { "pca9554", 8, },
37 { "pca9555", 16, },
38 { "pca9556", 8, },
39 { "pca9557", 8, },
40
41 { "max7310", 8, },
42 { "max7315", 8, },
43 { "pca6107", 8, },
44 { "tca6408", 8, },
45 { "tca6416", 16, },
46
47 { }
48};
49MODULE_DEVICE_TABLE(i2c, pca953x_id);
50
51struct pca953x_chip {
52 unsigned gpio_start;
53 uint16_t reg_output;
54 uint16_t reg_direction;
55
56 struct i2c_client *client;
57 struct pca953x_platform_data *dyn_pdata;
58 struct gpio_chip gpio_chip;
59 char **names;
60};
61
62static int pca953x_write_reg(struct pca953x_chip *chip, int reg, uint16_t val)
63{
64 int ret;
65
66 if (chip->gpio_chip.ngpio <= 8)
67 ret = i2c_smbus_write_byte_data(chip->client, reg, val);
68 else
69 ret = i2c_smbus_write_word_data(chip->client, reg << 1, val);
70
71 if (ret < 0) {
72 dev_err(&chip->client->dev, "failed writing register\n");
73 return ret;
74 }
75
76 return 0;
77}
78
79static int pca953x_read_reg(struct pca953x_chip *chip, int reg, uint16_t *val)
80{
81 int ret;
82
83 if (chip->gpio_chip.ngpio <= 8)
84 ret = i2c_smbus_read_byte_data(chip->client, reg);
85 else
86 ret = i2c_smbus_read_word_data(chip->client, reg << 1);
87
88 if (ret < 0) {
89 dev_err(&chip->client->dev, "failed reading register\n");
90 return ret;
91 }
92
93 *val = (uint16_t)ret;
94 return 0;
95}
96
97static int pca953x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
98{
99 struct pca953x_chip *chip;
100 uint16_t reg_val;
101 int ret;
102
103 chip = container_of(gc, struct pca953x_chip, gpio_chip);
104
105 reg_val = chip->reg_direction | (1u << off);
106 ret = pca953x_write_reg(chip, PCA953X_DIRECTION, reg_val);
107 if (ret)
108 return ret;
109
110 chip->reg_direction = reg_val;
111 return 0;
112}
113
114static int pca953x_gpio_direction_output(struct gpio_chip *gc,
115 unsigned off, int val)
116{
117 struct pca953x_chip *chip;
118 uint16_t reg_val;
119 int ret;
120
121 chip = container_of(gc, struct pca953x_chip, gpio_chip);
122
123
124 if (val)
125 reg_val = chip->reg_output | (1u << off);
126 else
127 reg_val = chip->reg_output & ~(1u << off);
128
129 ret = pca953x_write_reg(chip, PCA953X_OUTPUT, reg_val);
130 if (ret)
131 return ret;
132
133 chip->reg_output = reg_val;
134
135
136 reg_val = chip->reg_direction & ~(1u << off);
137 ret = pca953x_write_reg(chip, PCA953X_DIRECTION, reg_val);
138 if (ret)
139 return ret;
140
141 chip->reg_direction = reg_val;
142 return 0;
143}
144
145static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off)
146{
147 struct pca953x_chip *chip;
148 uint16_t reg_val;
149 int ret;
150
151 chip = container_of(gc, struct pca953x_chip, gpio_chip);
152
153 ret = pca953x_read_reg(chip, PCA953X_INPUT, ®_val);
154 if (ret < 0) {
155
156
157
158
159 return 0;
160 }
161
162 return (reg_val & (1u << off)) ? 1 : 0;
163}
164
165static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
166{
167 struct pca953x_chip *chip;
168 uint16_t reg_val;
169 int ret;
170
171 chip = container_of(gc, struct pca953x_chip, gpio_chip);
172
173 if (val)
174 reg_val = chip->reg_output | (1u << off);
175 else
176 reg_val = chip->reg_output & ~(1u << off);
177
178 ret = pca953x_write_reg(chip, PCA953X_OUTPUT, reg_val);
179 if (ret)
180 return;
181
182 chip->reg_output = reg_val;
183}
184
185static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)
186{
187 struct gpio_chip *gc;
188
189 gc = &chip->gpio_chip;
190
191 gc->direction_input = pca953x_gpio_direction_input;
192 gc->direction_output = pca953x_gpio_direction_output;
193 gc->get = pca953x_gpio_get_value;
194 gc->set = pca953x_gpio_set_value;
195 gc->can_sleep = 1;
196
197 gc->base = chip->gpio_start;
198 gc->ngpio = gpios;
199 gc->label = chip->client->name;
200 gc->dev = &chip->client->dev;
201 gc->owner = THIS_MODULE;
202 gc->names = chip->names;
203}
204
205
206
207
208#ifdef CONFIG_OF_GPIO
209
210
211
212static struct pca953x_platform_data *
213pca953x_get_alt_pdata(struct i2c_client *client)
214{
215 struct pca953x_platform_data *pdata;
216 struct device_node *node;
217 const uint16_t *val;
218
219 node = dev_archdata_get_node(&client->dev.archdata);
220 if (node == NULL)
221 return NULL;
222
223 pdata = kzalloc(sizeof(struct pca953x_platform_data), GFP_KERNEL);
224 if (pdata == NULL) {
225 dev_err(&client->dev, "Unable to allocate platform_data\n");
226 return NULL;
227 }
228
229 pdata->gpio_base = -1;
230 val = of_get_property(node, "linux,gpio-base", NULL);
231 if (val) {
232 if (*val < 0)
233 dev_warn(&client->dev,
234 "invalid gpio-base in device tree\n");
235 else
236 pdata->gpio_base = *val;
237 }
238
239 val = of_get_property(node, "polarity", NULL);
240 if (val)
241 pdata->invert = *val;
242
243 return pdata;
244}
245#else
246static struct pca953x_platform_data *
247pca953x_get_alt_pdata(struct i2c_client *client)
248{
249 return NULL;
250}
251#endif
252
253static int __devinit pca953x_probe(struct i2c_client *client,
254 const struct i2c_device_id *id)
255{
256 struct pca953x_platform_data *pdata;
257 struct pca953x_chip *chip;
258 int ret;
259
260 chip = kzalloc(sizeof(struct pca953x_chip), GFP_KERNEL);
261 if (chip == NULL)
262 return -ENOMEM;
263
264 pdata = client->dev.platform_data;
265 if (pdata == NULL) {
266 pdata = pca953x_get_alt_pdata(client);
267
268
269
270
271 chip->dyn_pdata = pdata;
272 }
273
274 if (pdata == NULL) {
275 dev_dbg(&client->dev, "no platform data\n");
276 ret = -EINVAL;
277 goto out_failed;
278 }
279
280 chip->client = client;
281
282 chip->gpio_start = pdata->gpio_base;
283
284 chip->names = pdata->names;
285
286
287
288
289 pca953x_setup_gpio(chip, id->driver_data);
290
291 ret = pca953x_read_reg(chip, PCA953X_OUTPUT, &chip->reg_output);
292 if (ret)
293 goto out_failed;
294
295 ret = pca953x_read_reg(chip, PCA953X_DIRECTION, &chip->reg_direction);
296 if (ret)
297 goto out_failed;
298
299
300 ret = pca953x_write_reg(chip, PCA953X_INVERT, pdata->invert);
301 if (ret)
302 goto out_failed;
303
304
305 ret = gpiochip_add(&chip->gpio_chip);
306 if (ret)
307 goto out_failed;
308
309 if (pdata->setup) {
310 ret = pdata->setup(client, chip->gpio_chip.base,
311 chip->gpio_chip.ngpio, pdata->context);
312 if (ret < 0)
313 dev_warn(&client->dev, "setup failed, %d\n", ret);
314 }
315
316 i2c_set_clientdata(client, chip);
317 return 0;
318
319out_failed:
320 kfree(chip->dyn_pdata);
321 kfree(chip);
322 return ret;
323}
324
325static int pca953x_remove(struct i2c_client *client)
326{
327 struct pca953x_platform_data *pdata = client->dev.platform_data;
328 struct pca953x_chip *chip = i2c_get_clientdata(client);
329 int ret = 0;
330
331 if (pdata->teardown) {
332 ret = pdata->teardown(client, chip->gpio_chip.base,
333 chip->gpio_chip.ngpio, pdata->context);
334 if (ret < 0) {
335 dev_err(&client->dev, "%s failed, %d\n",
336 "teardown", ret);
337 return ret;
338 }
339 }
340
341 ret = gpiochip_remove(&chip->gpio_chip);
342 if (ret) {
343 dev_err(&client->dev, "%s failed, %d\n",
344 "gpiochip_remove()", ret);
345 return ret;
346 }
347
348 kfree(chip->dyn_pdata);
349 kfree(chip);
350 return 0;
351}
352
353static struct i2c_driver pca953x_driver = {
354 .driver = {
355 .name = "pca953x",
356 },
357 .probe = pca953x_probe,
358 .remove = pca953x_remove,
359 .id_table = pca953x_id,
360};
361
362static int __init pca953x_init(void)
363{
364 return i2c_add_driver(&pca953x_driver);
365}
366
367
368
369subsys_initcall(pca953x_init);
370
371static void __exit pca953x_exit(void)
372{
373 i2c_del_driver(&pca953x_driver);
374}
375module_exit(pca953x_exit);
376
377MODULE_AUTHOR("eric miao <eric.miao@marvell.com>");
378MODULE_DESCRIPTION("GPIO expander driver for PCA953x");
379MODULE_LICENSE("GPL");
380
