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[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
214         if (!fw) {
215                 dev_err(dev, "firmware request failed\n");
216                 goto out;
217         }
218
219         /* handling firmware data is chip dependent */
220         mutex_lock(&chip->lock);
221
222         chip->fw = fw;
223         if (chip->cfg->firmware_cb)
224                 chip->cfg->firmware_cb(chip);
225
226         mutex_unlock(&chip->lock);
227
228 out:
229         /* firmware should be released for other channel use */
230         release_firmware(chip->fw);
231 }
232
233 static int lp55xx_request_firmware(struct lp55xx_chip *chip)
234 {
235         const char *name = chip->cl->name;
236         struct device *dev = &chip->cl->dev;
237
238         return request_firmware_nowait(THIS_MODULE, true, name, dev,
239                                 GFP_KERNEL, chip, lp55xx_firmware_loaded);
240 }
241
242 static ssize_t lp55xx_show_engine_select(struct device *dev,
243                             struct device_attribute *attr,
244                             char *buf)
245 {
246         struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
247         struct lp55xx_chip *chip = led->chip;
248
249         return sprintf(buf, "%d\n", chip->engine_idx);
250 }
251
252 static ssize_t lp55xx_store_engine_select(struct device *dev,
253                              struct device_attribute *attr,
254                              const char *buf, size_t len)
255 {
256         struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
257         struct lp55xx_chip *chip = led->chip;
258         unsigned long val;
259         int ret;
260
261         if (kstrtoul(buf, 0, &val))
262                 return -EINVAL;
263
264         /* select the engine to be run */
265
266         switch (val) {
267         case LP55XX_ENGINE_1:
268         case LP55XX_ENGINE_2:
269         case LP55XX_ENGINE_3:
270                 mutex_lock(&chip->lock);
271                 chip->engine_idx = val;
272                 ret = lp55xx_request_firmware(chip);
273                 mutex_unlock(&chip->lock);
274                 break;
275         default:
276                 dev_err(dev, "%lu: invalid engine index. (1, 2, 3)\n", val);
277                 return -EINVAL;
278         }
279
280         if (ret) {
281                 dev_err(dev, "request firmware err: %d\n", ret);
282                 return ret;
283         }
284
285         return len;
286 }
287
288 static inline void lp55xx_run_engine(struct lp55xx_chip *chip, bool start)
289 {
290         if (chip->cfg->run_engine)
291                 chip->cfg->run_engine(chip, start);
292 }
293
294 static ssize_t lp55xx_store_engine_run(struct device *dev,
295                              struct device_attribute *attr,
296                              const char *buf, size_t len)
297 {
298         struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
299         struct lp55xx_chip *chip = led->chip;
300         unsigned long val;
301
302         if (kstrtoul(buf, 0, &val))
303                 return -EINVAL;
304
305         /* run or stop the selected engine */
306
307         if (val <= 0) {
308                 lp55xx_run_engine(chip, false);
309                 return len;
310         }
311
312         mutex_lock(&chip->lock);
313         lp55xx_run_engine(chip, true);
314         mutex_unlock(&chip->lock);
315
316         return len;
317 }
318
319 static DEVICE_ATTR(select_engine, S_IRUGO | S_IWUSR,
320                    lp55xx_show_engine_select, lp55xx_store_engine_select);
321 static DEVICE_ATTR(run_engine, S_IWUSR, NULL, lp55xx_store_engine_run);
322
323 static struct attribute *lp55xx_engine_attributes[] = {
324         &dev_attr_select_engine.attr,
325         &dev_attr_run_engine.attr,
326         NULL,
327 };
328
329 static const struct attribute_group lp55xx_engine_attr_group = {
330         .attrs = lp55xx_engine_attributes,
331 };
332
333 int lp55xx_write(struct lp55xx_chip *chip, u8 reg, u8 val)
334 {
335         return i2c_smbus_write_byte_data(chip->cl, reg, val);
336 }
337 EXPORT_SYMBOL_GPL(lp55xx_write);
338
339 int lp55xx_read(struct lp55xx_chip *chip, u8 reg, u8 *val)
340 {
341         s32 ret;
342
343         ret = i2c_smbus_read_byte_data(chip->cl, reg);
344         if (ret < 0)
345                 return ret;
346
347         *val = ret;
348         return 0;
349 }
350 EXPORT_SYMBOL_GPL(lp55xx_read);
351
352 int lp55xx_update_bits(struct lp55xx_chip *chip, u8 reg, u8 mask, u8 val)
353 {
354         int ret;
355         u8 tmp;
356
357         ret = lp55xx_read(chip, reg, &tmp);
358         if (ret)
359                 return ret;
360
361         tmp &= ~mask;
362         tmp |= val & mask;
363
364         return lp55xx_write(chip, reg, tmp);
365 }
366 EXPORT_SYMBOL_GPL(lp55xx_update_bits);
367
368 bool lp55xx_is_extclk_used(struct lp55xx_chip *chip)
369 {
370         struct clk *clk;
371         int err;
372
373         clk = devm_clk_get(&chip->cl->dev, "32k_clk");
374         if (IS_ERR(clk))
375                 goto use_internal_clk;
376
377         err = clk_prepare_enable(clk);
378         if (err)
379                 goto use_internal_clk;
380
381         if (clk_get_rate(clk) != LP55XX_CLK_32K) {
382                 clk_disable_unprepare(clk);
383                 goto use_internal_clk;
384         }
385
386         dev_info(&chip->cl->dev, "%dHz external clock used\n",  LP55XX_CLK_32K);
387
388         chip->clk = clk;
389         return true;
390
391 use_internal_clk:
392         dev_info(&chip->cl->dev, "internal clock used\n");
393         return false;
394 }
395 EXPORT_SYMBOL_GPL(lp55xx_is_extclk_used);
396
397 int lp55xx_init_device(struct lp55xx_chip *chip)
398 {
399         struct lp55xx_platform_data *pdata;
400         struct lp55xx_device_config *cfg;
401         struct device *dev = &chip->cl->dev;
402         int ret = 0;
403
404         WARN_ON(!chip);
405
406         pdata = chip->pdata;
407         cfg = chip->cfg;
408
409         if (!pdata || !cfg)
410                 return -EINVAL;
411
412         if (gpio_is_valid(pdata->enable_gpio)) {
413                 ret = devm_gpio_request_one(dev, pdata->enable_gpio,
414                                             GPIOF_DIR_OUT, "lp5523_enable");
415                 if (ret < 0) {
416                         dev_err(dev, "could not acquire enable gpio (err=%d)\n",
417                                 ret);
418                         goto err;
419                 }
420
421                 gpio_set_value(pdata->enable_gpio, 0);
422                 usleep_range(1000, 2000); /* Keep enable down at least 1ms */
423                 gpio_set_value(pdata->enable_gpio, 1);
424                 usleep_range(1000, 2000); /* 500us abs min. */
425         }
426
427         lp55xx_reset_device(chip);
428
429         /*
430          * Exact value is not available. 10 - 20ms
431          * appears to be enough for reset.
432          */
433         usleep_range(10000, 20000);
434
435         ret = lp55xx_detect_device(chip);
436         if (ret) {
437                 dev_err(dev, "device detection err: %d\n", ret);
438                 goto err;
439         }
440
441         /* chip specific initialization */
442         ret = lp55xx_post_init_device(chip);
443         if (ret) {
444                 dev_err(dev, "post init device err: %d\n", ret);
445                 goto err_post_init;
446         }
447
448         return 0;
449
450 err_post_init:
451         lp55xx_deinit_device(chip);
452 err:
453         return ret;
454 }
455 EXPORT_SYMBOL_GPL(lp55xx_init_device);
456
457 void lp55xx_deinit_device(struct lp55xx_chip *chip)
458 {
459         struct lp55xx_platform_data *pdata = chip->pdata;
460
461         if (chip->clk)
462                 clk_disable_unprepare(chip->clk);
463
464         if (gpio_is_valid(pdata->enable_gpio))
465                 gpio_set_value(pdata->enable_gpio, 0);
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                 cfg[i].default_trigger =
590                         of_get_property(child, "linux,default-trigger", NULL);
591
592                 i++;
593         }
594
595         of_property_read_string(np, "label", &pdata->label);
596         of_property_read_u8(np, "clock-mode", &pdata->clock_mode);
597
598         pdata->enable_gpio = of_get_named_gpio(np, "enable-gpio", 0);
599
600         /* LP8501 specific */
601         of_property_read_u8(np, "pwr-sel", (u8 *)&pdata->pwr_sel);
602
603         dev->platform_data = pdata;
604
605         return 0;
606 }
607 EXPORT_SYMBOL_GPL(lp55xx_of_populate_pdata);
608
609 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
610 MODULE_DESCRIPTION("LP55xx Common Driver");
611 MODULE_LICENSE("GPL");