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Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
[karo-tx-linux.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 #include <linux/gpio.h>
24 #include <linux/of_gpio.h>
25
26 #include "leds-lp55xx-common.h"
27
28 /* External clock rate */
29 #define LP55XX_CLK_32K                  32768
30
31 static struct lp55xx_led *cdev_to_lp55xx_led(struct led_classdev *cdev)
32 {
33         return container_of(cdev, struct lp55xx_led, cdev);
34 }
35
36 static struct lp55xx_led *dev_to_lp55xx_led(struct device *dev)
37 {
38         return cdev_to_lp55xx_led(dev_get_drvdata(dev));
39 }
40
41 static void lp55xx_reset_device(struct lp55xx_chip *chip)
42 {
43         struct lp55xx_device_config *cfg = chip->cfg;
44         u8 addr = cfg->reset.addr;
45         u8 val  = cfg->reset.val;
46
47         /* no error checking here because no ACK from the device after reset */
48         lp55xx_write(chip, addr, val);
49 }
50
51 static int lp55xx_detect_device(struct lp55xx_chip *chip)
52 {
53         struct lp55xx_device_config *cfg = chip->cfg;
54         u8 addr = cfg->enable.addr;
55         u8 val  = cfg->enable.val;
56         int ret;
57
58         ret = lp55xx_write(chip, addr, val);
59         if (ret)
60                 return ret;
61
62         usleep_range(1000, 2000);
63
64         ret = lp55xx_read(chip, addr, &val);
65         if (ret)
66                 return ret;
67
68         if (val != cfg->enable.val)
69                 return -ENODEV;
70
71         return 0;
72 }
73
74 static int lp55xx_post_init_device(struct lp55xx_chip *chip)
75 {
76         struct lp55xx_device_config *cfg = chip->cfg;
77
78         if (!cfg->post_init_device)
79                 return 0;
80
81         return cfg->post_init_device(chip);
82 }
83
84 static ssize_t lp55xx_show_current(struct device *dev,
85                             struct device_attribute *attr,
86                             char *buf)
87 {
88         struct lp55xx_led *led = dev_to_lp55xx_led(dev);
89
90         return scnprintf(buf, PAGE_SIZE, "%d\n", led->led_current);
91 }
92
93 static ssize_t lp55xx_store_current(struct device *dev,
94                              struct device_attribute *attr,
95                              const char *buf, size_t len)
96 {
97         struct lp55xx_led *led = dev_to_lp55xx_led(dev);
98         struct lp55xx_chip *chip = led->chip;
99         unsigned long curr;
100
101         if (kstrtoul(buf, 0, &curr))
102                 return -EINVAL;
103
104         if (curr > led->max_current)
105                 return -EINVAL;
106
107         if (!chip->cfg->set_led_current)
108                 return len;
109
110         mutex_lock(&chip->lock);
111         chip->cfg->set_led_current(led, (u8)curr);
112         mutex_unlock(&chip->lock);
113
114         return len;
115 }
116
117 static ssize_t lp55xx_show_max_current(struct device *dev,
118                             struct device_attribute *attr,
119                             char *buf)
120 {
121         struct lp55xx_led *led = dev_to_lp55xx_led(dev);
122
123         return scnprintf(buf, PAGE_SIZE, "%d\n", led->max_current);
124 }
125
126 static DEVICE_ATTR(led_current, S_IRUGO | S_IWUSR, lp55xx_show_current,
127                 lp55xx_store_current);
128 static DEVICE_ATTR(max_current, S_IRUGO , lp55xx_show_max_current, NULL);
129
130 static struct attribute *lp55xx_led_attributes[] = {
131         &dev_attr_led_current.attr,
132         &dev_attr_max_current.attr,
133         NULL,
134 };
135
136 static struct attribute_group lp55xx_led_attr_group = {
137         .attrs = lp55xx_led_attributes
138 };
139
140 static void lp55xx_set_brightness(struct led_classdev *cdev,
141                              enum led_brightness brightness)
142 {
143         struct lp55xx_led *led = cdev_to_lp55xx_led(cdev);
144
145         led->brightness = (u8)brightness;
146         schedule_work(&led->brightness_work);
147 }
148
149 static int lp55xx_init_led(struct lp55xx_led *led,
150                         struct lp55xx_chip *chip, int chan)
151 {
152         struct lp55xx_platform_data *pdata = chip->pdata;
153         struct lp55xx_device_config *cfg = chip->cfg;
154         struct device *dev = &chip->cl->dev;
155         char name[32];
156         int ret;
157         int max_channel = cfg->max_channel;
158
159         if (chan >= max_channel) {
160                 dev_err(dev, "invalid channel: %d / %d\n", chan, max_channel);
161                 return -EINVAL;
162         }
163
164         if (pdata->led_config[chan].led_current == 0)
165                 return 0;
166
167         led->led_current = pdata->led_config[chan].led_current;
168         led->max_current = pdata->led_config[chan].max_current;
169         led->chan_nr = pdata->led_config[chan].chan_nr;
170         led->cdev.default_trigger = pdata->led_config[chan].default_trigger;
171
172         if (led->chan_nr >= max_channel) {
173                 dev_err(dev, "Use channel numbers between 0 and %d\n",
174                         max_channel - 1);
175                 return -EINVAL;
176         }
177
178         led->cdev.brightness_set = lp55xx_set_brightness;
179
180         if (pdata->led_config[chan].name) {
181                 led->cdev.name = pdata->led_config[chan].name;
182         } else {
183                 snprintf(name, sizeof(name), "%s:channel%d",
184                         pdata->label ? : chip->cl->name, chan);
185                 led->cdev.name = name;
186         }
187
188         /*
189          * register led class device for each channel and
190          * add device attributes
191          */
192
193         ret = led_classdev_register(dev, &led->cdev);
194         if (ret) {
195                 dev_err(dev, "led register err: %d\n", ret);
196                 return ret;
197         }
198
199         ret = sysfs_create_group(&led->cdev.dev->kobj, &lp55xx_led_attr_group);
200         if (ret) {
201                 dev_err(dev, "led sysfs err: %d\n", ret);
202                 led_classdev_unregister(&led->cdev);
203                 return ret;
204         }
205
206         return 0;
207 }
208
209 static void lp55xx_firmware_loaded(const struct firmware *fw, void *context)
210 {
211         struct lp55xx_chip *chip = context;
212         struct device *dev = &chip->cl->dev;
213         enum lp55xx_engine_index idx = chip->engine_idx;
214
215         if (!fw) {
216                 dev_err(dev, "firmware request failed\n");
217                 goto out;
218         }
219
220         /* handling firmware data is chip dependent */
221         mutex_lock(&chip->lock);
222
223         chip->engines[idx - 1].mode = LP55XX_ENGINE_LOAD;
224         chip->fw = fw;
225         if (chip->cfg->firmware_cb)
226                 chip->cfg->firmware_cb(chip);
227
228         mutex_unlock(&chip->lock);
229
230 out:
231         /* firmware should be released for other channel use */
232         release_firmware(chip->fw);
233 }
234
235 static int lp55xx_request_firmware(struct lp55xx_chip *chip)
236 {
237         const char *name = chip->cl->name;
238         struct device *dev = &chip->cl->dev;
239
240         return request_firmware_nowait(THIS_MODULE, true, name, dev,
241                                 GFP_KERNEL, chip, lp55xx_firmware_loaded);
242 }
243
244 static ssize_t lp55xx_show_engine_select(struct device *dev,
245                             struct device_attribute *attr,
246                             char *buf)
247 {
248         struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
249         struct lp55xx_chip *chip = led->chip;
250
251         return sprintf(buf, "%d\n", chip->engine_idx);
252 }
253
254 static ssize_t lp55xx_store_engine_select(struct device *dev,
255                              struct device_attribute *attr,
256                              const char *buf, size_t len)
257 {
258         struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
259         struct lp55xx_chip *chip = led->chip;
260         unsigned long val;
261         int ret;
262
263         if (kstrtoul(buf, 0, &val))
264                 return -EINVAL;
265
266         /* select the engine to be run */
267
268         switch (val) {
269         case LP55XX_ENGINE_1:
270         case LP55XX_ENGINE_2:
271         case LP55XX_ENGINE_3:
272                 mutex_lock(&chip->lock);
273                 chip->engine_idx = val;
274                 ret = lp55xx_request_firmware(chip);
275                 mutex_unlock(&chip->lock);
276                 break;
277         default:
278                 dev_err(dev, "%lu: invalid engine index. (1, 2, 3)\n", val);
279                 return -EINVAL;
280         }
281
282         if (ret) {
283                 dev_err(dev, "request firmware err: %d\n", ret);
284                 return ret;
285         }
286
287         return len;
288 }
289
290 static inline void lp55xx_run_engine(struct lp55xx_chip *chip, bool start)
291 {
292         if (chip->cfg->run_engine)
293                 chip->cfg->run_engine(chip, start);
294 }
295
296 static ssize_t lp55xx_store_engine_run(struct device *dev,
297                              struct device_attribute *attr,
298                              const char *buf, size_t len)
299 {
300         struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
301         struct lp55xx_chip *chip = led->chip;
302         unsigned long val;
303
304         if (kstrtoul(buf, 0, &val))
305                 return -EINVAL;
306
307         /* run or stop the selected engine */
308
309         if (val <= 0) {
310                 lp55xx_run_engine(chip, false);
311                 return len;
312         }
313
314         mutex_lock(&chip->lock);
315         lp55xx_run_engine(chip, true);
316         mutex_unlock(&chip->lock);
317
318         return len;
319 }
320
321 static DEVICE_ATTR(select_engine, S_IRUGO | S_IWUSR,
322                    lp55xx_show_engine_select, lp55xx_store_engine_select);
323 static DEVICE_ATTR(run_engine, S_IWUSR, NULL, lp55xx_store_engine_run);
324
325 static struct attribute *lp55xx_engine_attributes[] = {
326         &dev_attr_select_engine.attr,
327         &dev_attr_run_engine.attr,
328         NULL,
329 };
330
331 static const struct attribute_group lp55xx_engine_attr_group = {
332         .attrs = lp55xx_engine_attributes,
333 };
334
335 int lp55xx_write(struct lp55xx_chip *chip, u8 reg, u8 val)
336 {
337         return i2c_smbus_write_byte_data(chip->cl, reg, val);
338 }
339 EXPORT_SYMBOL_GPL(lp55xx_write);
340
341 int lp55xx_read(struct lp55xx_chip *chip, u8 reg, u8 *val)
342 {
343         s32 ret;
344
345         ret = i2c_smbus_read_byte_data(chip->cl, reg);
346         if (ret < 0)
347                 return ret;
348
349         *val = ret;
350         return 0;
351 }
352 EXPORT_SYMBOL_GPL(lp55xx_read);
353
354 int lp55xx_update_bits(struct lp55xx_chip *chip, u8 reg, u8 mask, u8 val)
355 {
356         int ret;
357         u8 tmp;
358
359         ret = lp55xx_read(chip, reg, &tmp);
360         if (ret)
361                 return ret;
362
363         tmp &= ~mask;
364         tmp |= val & mask;
365
366         return lp55xx_write(chip, reg, tmp);
367 }
368 EXPORT_SYMBOL_GPL(lp55xx_update_bits);
369
370 bool lp55xx_is_extclk_used(struct lp55xx_chip *chip)
371 {
372         struct clk *clk;
373         int err;
374
375         clk = devm_clk_get(&chip->cl->dev, "32k_clk");
376         if (IS_ERR(clk))
377                 goto use_internal_clk;
378
379         err = clk_prepare_enable(clk);
380         if (err)
381                 goto use_internal_clk;
382
383         if (clk_get_rate(clk) != LP55XX_CLK_32K) {
384                 clk_disable_unprepare(clk);
385                 goto use_internal_clk;
386         }
387
388         dev_info(&chip->cl->dev, "%dHz external clock used\n",  LP55XX_CLK_32K);
389
390         chip->clk = clk;
391         return true;
392
393 use_internal_clk:
394         dev_info(&chip->cl->dev, "internal clock used\n");
395         return false;
396 }
397 EXPORT_SYMBOL_GPL(lp55xx_is_extclk_used);
398
399 int lp55xx_init_device(struct lp55xx_chip *chip)
400 {
401         struct lp55xx_platform_data *pdata;
402         struct lp55xx_device_config *cfg;
403         struct device *dev = &chip->cl->dev;
404         int ret = 0;
405
406         WARN_ON(!chip);
407
408         pdata = chip->pdata;
409         cfg = chip->cfg;
410
411         if (!pdata || !cfg)
412                 return -EINVAL;
413
414         if (gpio_is_valid(pdata->enable_gpio)) {
415                 ret = devm_gpio_request_one(dev, pdata->enable_gpio,
416                                             GPIOF_DIR_OUT, "lp5523_enable");
417                 if (ret < 0) {
418                         dev_err(dev, "could not acquire enable gpio (err=%d)\n",
419                                 ret);
420                         goto err;
421                 }
422
423                 gpio_set_value(pdata->enable_gpio, 0);
424                 usleep_range(1000, 2000); /* Keep enable down at least 1ms */
425                 gpio_set_value(pdata->enable_gpio, 1);
426                 usleep_range(1000, 2000); /* 500us abs min. */
427         }
428
429         lp55xx_reset_device(chip);
430
431         /*
432          * Exact value is not available. 10 - 20ms
433          * appears to be enough for reset.
434          */
435         usleep_range(10000, 20000);
436
437         ret = lp55xx_detect_device(chip);
438         if (ret) {
439                 dev_err(dev, "device detection err: %d\n", ret);
440                 goto err;
441         }
442
443         /* chip specific initialization */
444         ret = lp55xx_post_init_device(chip);
445         if (ret) {
446                 dev_err(dev, "post init device err: %d\n", ret);
447                 goto err_post_init;
448         }
449
450         return 0;
451
452 err_post_init:
453         lp55xx_deinit_device(chip);
454 err:
455         return ret;
456 }
457 EXPORT_SYMBOL_GPL(lp55xx_init_device);
458
459 void lp55xx_deinit_device(struct lp55xx_chip *chip)
460 {
461         struct lp55xx_platform_data *pdata = chip->pdata;
462
463         if (chip->clk)
464                 clk_disable_unprepare(chip->clk);
465
466         if (gpio_is_valid(pdata->enable_gpio))
467                 gpio_set_value(pdata->enable_gpio, 0);
468 }
469 EXPORT_SYMBOL_GPL(lp55xx_deinit_device);
470
471 int lp55xx_register_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
472 {
473         struct lp55xx_platform_data *pdata = chip->pdata;
474         struct lp55xx_device_config *cfg = chip->cfg;
475         int num_channels = pdata->num_channels;
476         struct lp55xx_led *each;
477         u8 led_current;
478         int ret;
479         int i;
480
481         if (!cfg->brightness_work_fn) {
482                 dev_err(&chip->cl->dev, "empty brightness configuration\n");
483                 return -EINVAL;
484         }
485
486         for (i = 0; i < num_channels; i++) {
487
488                 /* do not initialize channels that are not connected */
489                 if (pdata->led_config[i].led_current == 0)
490                         continue;
491
492                 led_current = pdata->led_config[i].led_current;
493                 each = led + i;
494                 ret = lp55xx_init_led(each, chip, i);
495                 if (ret)
496                         goto err_init_led;
497
498                 INIT_WORK(&each->brightness_work, cfg->brightness_work_fn);
499
500                 chip->num_leds++;
501                 each->chip = chip;
502
503                 /* setting led current at each channel */
504                 if (cfg->set_led_current)
505                         cfg->set_led_current(each, led_current);
506         }
507
508         return 0;
509
510 err_init_led:
511         lp55xx_unregister_leds(led, chip);
512         return ret;
513 }
514 EXPORT_SYMBOL_GPL(lp55xx_register_leds);
515
516 void lp55xx_unregister_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
517 {
518         int i;
519         struct lp55xx_led *each;
520
521         for (i = 0; i < chip->num_leds; i++) {
522                 each = led + i;
523                 led_classdev_unregister(&each->cdev);
524                 flush_work(&each->brightness_work);
525         }
526 }
527 EXPORT_SYMBOL_GPL(lp55xx_unregister_leds);
528
529 int lp55xx_register_sysfs(struct lp55xx_chip *chip)
530 {
531         struct device *dev = &chip->cl->dev;
532         struct lp55xx_device_config *cfg = chip->cfg;
533         int ret;
534
535         if (!cfg->run_engine || !cfg->firmware_cb)
536                 goto dev_specific_attrs;
537
538         ret = sysfs_create_group(&dev->kobj, &lp55xx_engine_attr_group);
539         if (ret)
540                 return ret;
541
542 dev_specific_attrs:
543         return cfg->dev_attr_group ?
544                 sysfs_create_group(&dev->kobj, cfg->dev_attr_group) : 0;
545 }
546 EXPORT_SYMBOL_GPL(lp55xx_register_sysfs);
547
548 void lp55xx_unregister_sysfs(struct lp55xx_chip *chip)
549 {
550         struct device *dev = &chip->cl->dev;
551         struct lp55xx_device_config *cfg = chip->cfg;
552
553         if (cfg->dev_attr_group)
554                 sysfs_remove_group(&dev->kobj, cfg->dev_attr_group);
555
556         sysfs_remove_group(&dev->kobj, &lp55xx_engine_attr_group);
557 }
558 EXPORT_SYMBOL_GPL(lp55xx_unregister_sysfs);
559
560 int lp55xx_of_populate_pdata(struct device *dev, struct device_node *np)
561 {
562         struct device_node *child;
563         struct lp55xx_platform_data *pdata;
564         struct lp55xx_led_config *cfg;
565         int num_channels;
566         int i = 0;
567
568         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
569         if (!pdata)
570                 return -ENOMEM;
571
572         num_channels = of_get_child_count(np);
573         if (num_channels == 0) {
574                 dev_err(dev, "no LED channels\n");
575                 return -EINVAL;
576         }
577
578         cfg = devm_kzalloc(dev, sizeof(*cfg) * num_channels, GFP_KERNEL);
579         if (!cfg)
580                 return -ENOMEM;
581
582         pdata->led_config = &cfg[0];
583         pdata->num_channels = num_channels;
584
585         for_each_child_of_node(np, child) {
586                 cfg[i].chan_nr = i;
587
588                 of_property_read_string(child, "chan-name", &cfg[i].name);
589                 of_property_read_u8(child, "led-cur", &cfg[i].led_current);
590                 of_property_read_u8(child, "max-cur", &cfg[i].max_current);
591                 cfg[i].default_trigger =
592                         of_get_property(child, "linux,default-trigger", NULL);
593
594                 i++;
595         }
596
597         of_property_read_string(np, "label", &pdata->label);
598         of_property_read_u8(np, "clock-mode", &pdata->clock_mode);
599
600         pdata->enable_gpio = of_get_named_gpio(np, "enable-gpio", 0);
601
602         /* LP8501 specific */
603         of_property_read_u8(np, "pwr-sel", (u8 *)&pdata->pwr_sel);
604
605         dev->platform_data = pdata;
606
607         return 0;
608 }
609 EXPORT_SYMBOL_GPL(lp55xx_of_populate_pdata);
610
611 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
612 MODULE_DESCRIPTION("LP55xx Common Driver");
613 MODULE_LICENSE("GPL");