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[mirror_ubuntu-artful-kernel.git] / drivers / leds / leds-lp55xx-common.c
1 /*
2 * LP5521/LP5523/LP55231/LP5562 Common Driver
3 *
4 * Copyright 2012 Texas Instruments
5 *
6 * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * Derived from leds-lp5521.c, leds-lp5523.c
13 */
14
15 #include <linux/clk.h>
16 #include <linux/delay.h>
17 #include <linux/firmware.h>
18 #include <linux/i2c.h>
19 #include <linux/leds.h>
20 #include <linux/module.h>
21 #include <linux/platform_data/leds-lp55xx.h>
22 #include <linux/slab.h>
23
24 #include "leds-lp55xx-common.h"
25
26 /* External clock rate */
27 #define LP55XX_CLK_32K 32768
28
29 static struct lp55xx_led *cdev_to_lp55xx_led(struct led_classdev *cdev)
30 {
31 return container_of(cdev, struct lp55xx_led, cdev);
32 }
33
34 static struct lp55xx_led *dev_to_lp55xx_led(struct device *dev)
35 {
36 return cdev_to_lp55xx_led(dev_get_drvdata(dev));
37 }
38
39 static void lp55xx_reset_device(struct lp55xx_chip *chip)
40 {
41 struct lp55xx_device_config *cfg = chip->cfg;
42 u8 addr = cfg->reset.addr;
43 u8 val = cfg->reset.val;
44
45 /* no error checking here because no ACK from the device after reset */
46 lp55xx_write(chip, addr, val);
47 }
48
49 static int lp55xx_detect_device(struct lp55xx_chip *chip)
50 {
51 struct lp55xx_device_config *cfg = chip->cfg;
52 u8 addr = cfg->enable.addr;
53 u8 val = cfg->enable.val;
54 int ret;
55
56 ret = lp55xx_write(chip, addr, val);
57 if (ret)
58 return ret;
59
60 usleep_range(1000, 2000);
61
62 ret = lp55xx_read(chip, addr, &val);
63 if (ret)
64 return ret;
65
66 if (val != cfg->enable.val)
67 return -ENODEV;
68
69 return 0;
70 }
71
72 static int lp55xx_post_init_device(struct lp55xx_chip *chip)
73 {
74 struct lp55xx_device_config *cfg = chip->cfg;
75
76 if (!cfg->post_init_device)
77 return 0;
78
79 return cfg->post_init_device(chip);
80 }
81
82 static ssize_t lp55xx_show_current(struct device *dev,
83 struct device_attribute *attr,
84 char *buf)
85 {
86 struct lp55xx_led *led = dev_to_lp55xx_led(dev);
87
88 return scnprintf(buf, PAGE_SIZE, "%d\n", led->led_current);
89 }
90
91 static ssize_t lp55xx_store_current(struct device *dev,
92 struct device_attribute *attr,
93 const char *buf, size_t len)
94 {
95 struct lp55xx_led *led = dev_to_lp55xx_led(dev);
96 struct lp55xx_chip *chip = led->chip;
97 unsigned long curr;
98
99 if (kstrtoul(buf, 0, &curr))
100 return -EINVAL;
101
102 if (curr > led->max_current)
103 return -EINVAL;
104
105 if (!chip->cfg->set_led_current)
106 return len;
107
108 mutex_lock(&chip->lock);
109 chip->cfg->set_led_current(led, (u8)curr);
110 mutex_unlock(&chip->lock);
111
112 return len;
113 }
114
115 static ssize_t lp55xx_show_max_current(struct device *dev,
116 struct device_attribute *attr,
117 char *buf)
118 {
119 struct lp55xx_led *led = dev_to_lp55xx_led(dev);
120
121 return scnprintf(buf, PAGE_SIZE, "%d\n", led->max_current);
122 }
123
124 static DEVICE_ATTR(led_current, S_IRUGO | S_IWUSR, lp55xx_show_current,
125 lp55xx_store_current);
126 static DEVICE_ATTR(max_current, S_IRUGO , lp55xx_show_max_current, NULL);
127
128 static struct attribute *lp55xx_led_attributes[] = {
129 &dev_attr_led_current.attr,
130 &dev_attr_max_current.attr,
131 NULL,
132 };
133
134 static struct attribute_group lp55xx_led_attr_group = {
135 .attrs = lp55xx_led_attributes
136 };
137
138 static void lp55xx_set_brightness(struct led_classdev *cdev,
139 enum led_brightness brightness)
140 {
141 struct lp55xx_led *led = cdev_to_lp55xx_led(cdev);
142
143 led->brightness = (u8)brightness;
144 schedule_work(&led->brightness_work);
145 }
146
147 static int lp55xx_init_led(struct lp55xx_led *led,
148 struct lp55xx_chip *chip, int chan)
149 {
150 struct lp55xx_platform_data *pdata = chip->pdata;
151 struct lp55xx_device_config *cfg = chip->cfg;
152 struct device *dev = &chip->cl->dev;
153 char name[32];
154 int ret;
155 int max_channel = cfg->max_channel;
156
157 if (chan >= max_channel) {
158 dev_err(dev, "invalid channel: %d / %d\n", chan, max_channel);
159 return -EINVAL;
160 }
161
162 if (pdata->led_config[chan].led_current == 0)
163 return 0;
164
165 led->led_current = pdata->led_config[chan].led_current;
166 led->max_current = pdata->led_config[chan].max_current;
167 led->chan_nr = pdata->led_config[chan].chan_nr;
168
169 if (led->chan_nr >= max_channel) {
170 dev_err(dev, "Use channel numbers between 0 and %d\n",
171 max_channel - 1);
172 return -EINVAL;
173 }
174
175 led->cdev.brightness_set = lp55xx_set_brightness;
176
177 if (pdata->led_config[chan].name) {
178 led->cdev.name = pdata->led_config[chan].name;
179 } else {
180 snprintf(name, sizeof(name), "%s:channel%d",
181 pdata->label ? : chip->cl->name, chan);
182 led->cdev.name = name;
183 }
184
185 /*
186 * register led class device for each channel and
187 * add device attributes
188 */
189
190 ret = led_classdev_register(dev, &led->cdev);
191 if (ret) {
192 dev_err(dev, "led register err: %d\n", ret);
193 return ret;
194 }
195
196 ret = sysfs_create_group(&led->cdev.dev->kobj, &lp55xx_led_attr_group);
197 if (ret) {
198 dev_err(dev, "led sysfs err: %d\n", ret);
199 led_classdev_unregister(&led->cdev);
200 return ret;
201 }
202
203 return 0;
204 }
205
206 static void lp55xx_firmware_loaded(const struct firmware *fw, void *context)
207 {
208 struct lp55xx_chip *chip = context;
209 struct device *dev = &chip->cl->dev;
210
211 if (!fw) {
212 dev_err(dev, "firmware request failed\n");
213 goto out;
214 }
215
216 /* handling firmware data is chip dependent */
217 mutex_lock(&chip->lock);
218
219 chip->fw = fw;
220 if (chip->cfg->firmware_cb)
221 chip->cfg->firmware_cb(chip);
222
223 mutex_unlock(&chip->lock);
224
225 out:
226 /* firmware should be released for other channel use */
227 release_firmware(chip->fw);
228 }
229
230 static int lp55xx_request_firmware(struct lp55xx_chip *chip)
231 {
232 const char *name = chip->cl->name;
233 struct device *dev = &chip->cl->dev;
234
235 return request_firmware_nowait(THIS_MODULE, true, name, dev,
236 GFP_KERNEL, chip, lp55xx_firmware_loaded);
237 }
238
239 static ssize_t lp55xx_show_engine_select(struct device *dev,
240 struct device_attribute *attr,
241 char *buf)
242 {
243 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
244 struct lp55xx_chip *chip = led->chip;
245
246 return sprintf(buf, "%d\n", chip->engine_idx);
247 }
248
249 static ssize_t lp55xx_store_engine_select(struct device *dev,
250 struct device_attribute *attr,
251 const char *buf, size_t len)
252 {
253 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
254 struct lp55xx_chip *chip = led->chip;
255 unsigned long val;
256 int ret;
257
258 if (kstrtoul(buf, 0, &val))
259 return -EINVAL;
260
261 /* select the engine to be run */
262
263 switch (val) {
264 case LP55XX_ENGINE_1:
265 case LP55XX_ENGINE_2:
266 case LP55XX_ENGINE_3:
267 mutex_lock(&chip->lock);
268 chip->engine_idx = val;
269 ret = lp55xx_request_firmware(chip);
270 mutex_unlock(&chip->lock);
271 break;
272 default:
273 dev_err(dev, "%lu: invalid engine index. (1, 2, 3)\n", val);
274 return -EINVAL;
275 }
276
277 if (ret) {
278 dev_err(dev, "request firmware err: %d\n", ret);
279 return ret;
280 }
281
282 return len;
283 }
284
285 static inline void lp55xx_run_engine(struct lp55xx_chip *chip, bool start)
286 {
287 if (chip->cfg->run_engine)
288 chip->cfg->run_engine(chip, start);
289 }
290
291 static ssize_t lp55xx_store_engine_run(struct device *dev,
292 struct device_attribute *attr,
293 const char *buf, size_t len)
294 {
295 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
296 struct lp55xx_chip *chip = led->chip;
297 unsigned long val;
298
299 if (kstrtoul(buf, 0, &val))
300 return -EINVAL;
301
302 /* run or stop the selected engine */
303
304 if (val <= 0) {
305 lp55xx_run_engine(chip, false);
306 return len;
307 }
308
309 mutex_lock(&chip->lock);
310 lp55xx_run_engine(chip, true);
311 mutex_unlock(&chip->lock);
312
313 return len;
314 }
315
316 static DEVICE_ATTR(select_engine, S_IRUGO | S_IWUSR,
317 lp55xx_show_engine_select, lp55xx_store_engine_select);
318 static DEVICE_ATTR(run_engine, S_IWUSR, NULL, lp55xx_store_engine_run);
319
320 static struct attribute *lp55xx_engine_attributes[] = {
321 &dev_attr_select_engine.attr,
322 &dev_attr_run_engine.attr,
323 NULL,
324 };
325
326 static const struct attribute_group lp55xx_engine_attr_group = {
327 .attrs = lp55xx_engine_attributes,
328 };
329
330 int lp55xx_write(struct lp55xx_chip *chip, u8 reg, u8 val)
331 {
332 return i2c_smbus_write_byte_data(chip->cl, reg, val);
333 }
334 EXPORT_SYMBOL_GPL(lp55xx_write);
335
336 int lp55xx_read(struct lp55xx_chip *chip, u8 reg, u8 *val)
337 {
338 s32 ret;
339
340 ret = i2c_smbus_read_byte_data(chip->cl, reg);
341 if (ret < 0)
342 return ret;
343
344 *val = ret;
345 return 0;
346 }
347 EXPORT_SYMBOL_GPL(lp55xx_read);
348
349 int lp55xx_update_bits(struct lp55xx_chip *chip, u8 reg, u8 mask, u8 val)
350 {
351 int ret;
352 u8 tmp;
353
354 ret = lp55xx_read(chip, reg, &tmp);
355 if (ret)
356 return ret;
357
358 tmp &= ~mask;
359 tmp |= val & mask;
360
361 return lp55xx_write(chip, reg, tmp);
362 }
363 EXPORT_SYMBOL_GPL(lp55xx_update_bits);
364
365 bool lp55xx_is_extclk_used(struct lp55xx_chip *chip)
366 {
367 struct clk *clk;
368 int err;
369
370 clk = devm_clk_get(&chip->cl->dev, "32k_clk");
371 if (IS_ERR(clk))
372 goto use_internal_clk;
373
374 err = clk_prepare_enable(clk);
375 if (err)
376 goto use_internal_clk;
377
378 if (clk_get_rate(clk) != LP55XX_CLK_32K) {
379 clk_disable_unprepare(clk);
380 goto use_internal_clk;
381 }
382
383 dev_info(&chip->cl->dev, "%dHz external clock used\n", LP55XX_CLK_32K);
384
385 chip->clk = clk;
386 return true;
387
388 use_internal_clk:
389 dev_info(&chip->cl->dev, "internal clock used\n");
390 return false;
391 }
392 EXPORT_SYMBOL_GPL(lp55xx_is_extclk_used);
393
394 int lp55xx_init_device(struct lp55xx_chip *chip)
395 {
396 struct lp55xx_platform_data *pdata;
397 struct lp55xx_device_config *cfg;
398 struct device *dev = &chip->cl->dev;
399 int ret = 0;
400
401 WARN_ON(!chip);
402
403 pdata = chip->pdata;
404 cfg = chip->cfg;
405
406 if (!pdata || !cfg)
407 return -EINVAL;
408
409 if (pdata->setup_resources) {
410 ret = pdata->setup_resources();
411 if (ret < 0) {
412 dev_err(dev, "setup resoure err: %d\n", ret);
413 goto err;
414 }
415 }
416
417 if (pdata->enable) {
418 pdata->enable(0);
419 usleep_range(1000, 2000); /* Keep enable down at least 1ms */
420 pdata->enable(1);
421 usleep_range(1000, 2000); /* 500us abs min. */
422 }
423
424 lp55xx_reset_device(chip);
425
426 /*
427 * Exact value is not available. 10 - 20ms
428 * appears to be enough for reset.
429 */
430 usleep_range(10000, 20000);
431
432 ret = lp55xx_detect_device(chip);
433 if (ret) {
434 dev_err(dev, "device detection err: %d\n", ret);
435 goto err;
436 }
437
438 /* chip specific initialization */
439 ret = lp55xx_post_init_device(chip);
440 if (ret) {
441 dev_err(dev, "post init device err: %d\n", ret);
442 goto err_post_init;
443 }
444
445 return 0;
446
447 err_post_init:
448 lp55xx_deinit_device(chip);
449 err:
450 return ret;
451 }
452 EXPORT_SYMBOL_GPL(lp55xx_init_device);
453
454 void lp55xx_deinit_device(struct lp55xx_chip *chip)
455 {
456 struct lp55xx_platform_data *pdata = chip->pdata;
457
458 if (chip->clk)
459 clk_disable_unprepare(chip->clk);
460
461 if (pdata->enable)
462 pdata->enable(0);
463
464 if (pdata->release_resources)
465 pdata->release_resources();
466 }
467 EXPORT_SYMBOL_GPL(lp55xx_deinit_device);
468
469 int lp55xx_register_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
470 {
471 struct lp55xx_platform_data *pdata = chip->pdata;
472 struct lp55xx_device_config *cfg = chip->cfg;
473 int num_channels = pdata->num_channels;
474 struct lp55xx_led *each;
475 u8 led_current;
476 int ret;
477 int i;
478
479 if (!cfg->brightness_work_fn) {
480 dev_err(&chip->cl->dev, "empty brightness configuration\n");
481 return -EINVAL;
482 }
483
484 for (i = 0; i < num_channels; i++) {
485
486 /* do not initialize channels that are not connected */
487 if (pdata->led_config[i].led_current == 0)
488 continue;
489
490 led_current = pdata->led_config[i].led_current;
491 each = led + i;
492 ret = lp55xx_init_led(each, chip, i);
493 if (ret)
494 goto err_init_led;
495
496 INIT_WORK(&each->brightness_work, cfg->brightness_work_fn);
497
498 chip->num_leds++;
499 each->chip = chip;
500
501 /* setting led current at each channel */
502 if (cfg->set_led_current)
503 cfg->set_led_current(each, led_current);
504 }
505
506 return 0;
507
508 err_init_led:
509 lp55xx_unregister_leds(led, chip);
510 return ret;
511 }
512 EXPORT_SYMBOL_GPL(lp55xx_register_leds);
513
514 void lp55xx_unregister_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
515 {
516 int i;
517 struct lp55xx_led *each;
518
519 for (i = 0; i < chip->num_leds; i++) {
520 each = led + i;
521 led_classdev_unregister(&each->cdev);
522 flush_work(&each->brightness_work);
523 }
524 }
525 EXPORT_SYMBOL_GPL(lp55xx_unregister_leds);
526
527 int lp55xx_register_sysfs(struct lp55xx_chip *chip)
528 {
529 struct device *dev = &chip->cl->dev;
530 struct lp55xx_device_config *cfg = chip->cfg;
531 int ret;
532
533 if (!cfg->run_engine || !cfg->firmware_cb)
534 goto dev_specific_attrs;
535
536 ret = sysfs_create_group(&dev->kobj, &lp55xx_engine_attr_group);
537 if (ret)
538 return ret;
539
540 dev_specific_attrs:
541 return cfg->dev_attr_group ?
542 sysfs_create_group(&dev->kobj, cfg->dev_attr_group) : 0;
543 }
544 EXPORT_SYMBOL_GPL(lp55xx_register_sysfs);
545
546 void lp55xx_unregister_sysfs(struct lp55xx_chip *chip)
547 {
548 struct device *dev = &chip->cl->dev;
549 struct lp55xx_device_config *cfg = chip->cfg;
550
551 if (cfg->dev_attr_group)
552 sysfs_remove_group(&dev->kobj, cfg->dev_attr_group);
553
554 sysfs_remove_group(&dev->kobj, &lp55xx_engine_attr_group);
555 }
556 EXPORT_SYMBOL_GPL(lp55xx_unregister_sysfs);
557
558 int lp55xx_of_populate_pdata(struct device *dev, struct device_node *np)
559 {
560 struct device_node *child;
561 struct lp55xx_platform_data *pdata;
562 struct lp55xx_led_config *cfg;
563 int num_channels;
564 int i = 0;
565
566 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
567 if (!pdata)
568 return -ENOMEM;
569
570 num_channels = of_get_child_count(np);
571 if (num_channels == 0) {
572 dev_err(dev, "no LED channels\n");
573 return -EINVAL;
574 }
575
576 cfg = devm_kzalloc(dev, sizeof(*cfg) * num_channels, GFP_KERNEL);
577 if (!cfg)
578 return -ENOMEM;
579
580 pdata->led_config = &cfg[0];
581 pdata->num_channels = num_channels;
582
583 for_each_child_of_node(np, child) {
584 cfg[i].chan_nr = i;
585
586 of_property_read_string(child, "chan-name", &cfg[i].name);
587 of_property_read_u8(child, "led-cur", &cfg[i].led_current);
588 of_property_read_u8(child, "max-cur", &cfg[i].max_current);
589
590 i++;
591 }
592
593 of_property_read_string(np, "label", &pdata->label);
594 of_property_read_u8(np, "clock-mode", &pdata->clock_mode);
595
596 dev->platform_data = pdata;
597
598 return 0;
599 }
600 EXPORT_SYMBOL_GPL(lp55xx_of_populate_pdata);
601
602 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
603 MODULE_DESCRIPTION("LP55xx Common Driver");
604 MODULE_LICENSE("GPL");