1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43#include <linux/module.h>
44#include <linux/delay.h>
45#include <linux/string.h>
46#include <linux/ctype.h>
47#include <linux/leds.h>
48#include <linux/err.h>
49#include <linux/i2c.h>
50#include <linux/workqueue.h>
51#include <linux/slab.h>
52
53
54#define PCA955X_LS_LED_ON 0x0
55#define PCA955X_LS_LED_OFF 0x1
56#define PCA955X_LS_BLINK0 0x2
57#define PCA955X_LS_BLINK1 0x3
58
59enum pca955x_type {
60 pca9550,
61 pca9551,
62 pca9552,
63 pca9553,
64};
65
66struct pca955x_chipdef {
67 int bits;
68 u8 slv_addr;
69 int slv_addr_shift;
70};
71
72static struct pca955x_chipdef pca955x_chipdefs[] = {
73 [pca9550] = {
74 .bits = 2,
75 .slv_addr = 0x60,
76 .slv_addr_shift = 1,
77 },
78 [pca9551] = {
79 .bits = 8,
80 .slv_addr = 0x60,
81 .slv_addr_shift = 3,
82 },
83 [pca9552] = {
84 .bits = 16,
85 .slv_addr = 0x60,
86 .slv_addr_shift = 3,
87 },
88 [pca9553] = {
89 .bits = 4,
90 .slv_addr = 0x62,
91 .slv_addr_shift = 1,
92 },
93};
94
95static const struct i2c_device_id pca955x_id[] = {
96 { "pca9550", pca9550 },
97 { "pca9551", pca9551 },
98 { "pca9552", pca9552 },
99 { "pca9553", pca9553 },
100 { }
101};
102MODULE_DEVICE_TABLE(i2c, pca955x_id);
103
104struct pca955x {
105 struct mutex lock;
106 struct pca955x_led *leds;
107 struct pca955x_chipdef *chipdef;
108 struct i2c_client *client;
109};
110
111struct pca955x_led {
112 struct pca955x *pca955x;
113 struct work_struct work;
114 enum led_brightness brightness;
115 struct led_classdev led_cdev;
116 int led_num;
117 char name[32];
118};
119
120
121static inline int pca95xx_num_input_regs(int bits)
122{
123 return (bits + 7) / 8;
124}
125
126
127static inline int pca95xx_num_led_regs(int bits)
128{
129 return (bits + 3) / 4;
130}
131
132
133
134
135
136static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state)
137{
138 return (oldval & (~(0x3 << (led_num << 1)))) |
139 ((state & 0x3) << (led_num << 1));
140}
141
142
143
144
145
146static void pca955x_write_psc(struct i2c_client *client, int n, u8 val)
147{
148 struct pca955x *pca955x = i2c_get_clientdata(client);
149
150 i2c_smbus_write_byte_data(client,
151 pca95xx_num_input_regs(pca955x->chipdef->bits) + 2*n,
152 val);
153}
154
155
156
157
158
159
160
161
162static void pca955x_write_pwm(struct i2c_client *client, int n, u8 val)
163{
164 struct pca955x *pca955x = i2c_get_clientdata(client);
165
166 i2c_smbus_write_byte_data(client,
167 pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + 2*n,
168 val);
169}
170
171
172
173
174
175static void pca955x_write_ls(struct i2c_client *client, int n, u8 val)
176{
177 struct pca955x *pca955x = i2c_get_clientdata(client);
178
179 i2c_smbus_write_byte_data(client,
180 pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n,
181 val);
182}
183
184
185
186
187
188static u8 pca955x_read_ls(struct i2c_client *client, int n)
189{
190 struct pca955x *pca955x = i2c_get_clientdata(client);
191
192 return (u8) i2c_smbus_read_byte_data(client,
193 pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n);
194}
195
196static void pca955x_led_work(struct work_struct *work)
197{
198 struct pca955x_led *pca955x_led;
199 struct pca955x *pca955x;
200 u8 ls;
201 int chip_ls;
202 int ls_led;
203
204 pca955x_led = container_of(work, struct pca955x_led, work);
205 pca955x = pca955x_led->pca955x;
206
207 chip_ls = pca955x_led->led_num / 4;
208 ls_led = pca955x_led->led_num % 4;
209
210 mutex_lock(&pca955x->lock);
211
212 ls = pca955x_read_ls(pca955x->client, chip_ls);
213
214 switch (pca955x_led->brightness) {
215 case LED_FULL:
216 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON);
217 break;
218 case LED_OFF:
219 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF);
220 break;
221 case LED_HALF:
222 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0);
223 break;
224 default:
225
226
227
228
229
230
231
232 pca955x_write_pwm(pca955x->client, 1,
233 255 - pca955x_led->brightness);
234 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1);
235 break;
236 }
237
238 pca955x_write_ls(pca955x->client, chip_ls, ls);
239
240 mutex_unlock(&pca955x->lock);
241}
242
243static void pca955x_led_set(struct led_classdev *led_cdev, enum led_brightness value)
244{
245 struct pca955x_led *pca955x;
246
247 pca955x = container_of(led_cdev, struct pca955x_led, led_cdev);
248
249 pca955x->brightness = value;
250
251
252
253
254
255 schedule_work(&pca955x->work);
256}
257
258static int pca955x_probe(struct i2c_client *client,
259 const struct i2c_device_id *id)
260{
261 struct pca955x *pca955x;
262 struct pca955x_led *pca955x_led;
263 struct pca955x_chipdef *chip;
264 struct i2c_adapter *adapter;
265 struct led_platform_data *pdata;
266 int i, err;
267
268 chip = &pca955x_chipdefs[id->driver_data];
269 adapter = to_i2c_adapter(client->dev.parent);
270 pdata = dev_get_platdata(&client->dev);
271
272
273 if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) !=
274 chip->slv_addr) {
275 dev_err(&client->dev, "invalid slave address %02x\n",
276 client->addr);
277 return -ENODEV;
278 }
279
280 dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at "
281 "slave address 0x%02x\n",
282 id->name, chip->bits, client->addr);
283
284 if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
285 return -EIO;
286
287 if (pdata) {
288 if (pdata->num_leds != chip->bits) {
289 dev_err(&client->dev, "board info claims %d LEDs"
290 " on a %d-bit chip\n",
291 pdata->num_leds, chip->bits);
292 return -ENODEV;
293 }
294 }
295
296 pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL);
297 if (!pca955x)
298 return -ENOMEM;
299
300 pca955x->leds = devm_kzalloc(&client->dev,
301 sizeof(*pca955x_led) * chip->bits, GFP_KERNEL);
302 if (!pca955x->leds)
303 return -ENOMEM;
304
305 i2c_set_clientdata(client, pca955x);
306
307 mutex_init(&pca955x->lock);
308 pca955x->client = client;
309 pca955x->chipdef = chip;
310
311 for (i = 0; i < chip->bits; i++) {
312 pca955x_led = &pca955x->leds[i];
313 pca955x_led->led_num = i;
314 pca955x_led->pca955x = pca955x;
315
316
317 if (pdata) {
318 if (pdata->leds[i].name)
319 snprintf(pca955x_led->name,
320 sizeof(pca955x_led->name), "pca955x:%s",
321 pdata->leds[i].name);
322 if (pdata->leds[i].default_trigger)
323 pca955x_led->led_cdev.default_trigger =
324 pdata->leds[i].default_trigger;
325 } else {
326 snprintf(pca955x_led->name, sizeof(pca955x_led->name),
327 "pca955x:%d", i);
328 }
329
330 pca955x_led->led_cdev.name = pca955x_led->name;
331 pca955x_led->led_cdev.brightness_set = pca955x_led_set;
332
333 INIT_WORK(&pca955x_led->work, pca955x_led_work);
334
335 err = led_classdev_register(&client->dev,
336 &pca955x_led->led_cdev);
337 if (err < 0)
338 goto exit;
339 }
340
341
342 for (i = 0; i < pca95xx_num_led_regs(chip->bits); i++)
343 pca955x_write_ls(client, i, 0x55);
344
345
346 pca955x_write_pwm(client, 0, 255-LED_HALF);
347
348
349 pca955x_write_pwm(client, 1, 0);
350
351
352 pca955x_write_psc(client, 0, 0);
353 pca955x_write_psc(client, 1, 0);
354
355 return 0;
356
357exit:
358 while (i--) {
359 led_classdev_unregister(&pca955x->leds[i].led_cdev);
360 cancel_work_sync(&pca955x->leds[i].work);
361 }
362
363 return err;
364}
365
366static int pca955x_remove(struct i2c_client *client)
367{
368 struct pca955x *pca955x = i2c_get_clientdata(client);
369 int i;
370
371 for (i = 0; i < pca955x->chipdef->bits; i++) {
372 led_classdev_unregister(&pca955x->leds[i].led_cdev);
373 cancel_work_sync(&pca955x->leds[i].work);
374 }
375
376 return 0;
377}
378
379static struct i2c_driver pca955x_driver = {
380 .driver = {
381 .name = "leds-pca955x",
382 .owner = THIS_MODULE,
383 },
384 .probe = pca955x_probe,
385 .remove = pca955x_remove,
386 .id_table = pca955x_id,
387};
388
389module_i2c_driver(pca955x_driver);
390
391MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>");
392MODULE_DESCRIPTION("PCA955x LED driver");
393MODULE_LICENSE("GPL v2");
394