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
cdev_to_lp55xx_led(struct led_classdev * cdev)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
dev_to_lp55xx_led(struct device * dev)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
lp55xx_reset_device(struct lp55xx_chip * chip)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
lp55xx_detect_device(struct lp55xx_chip * chip)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
lp55xx_post_init_device(struct lp55xx_chip * chip)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
lp55xx_show_current(struct device * dev,struct device_attribute * attr,char * buf)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
lp55xx_store_current(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)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
lp55xx_show_max_current(struct device * dev,struct device_attribute * attr,char * buf)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_attrs[] = {
131 &dev_attr_led_current.attr,
132 &dev_attr_max_current.attr,
133 NULL,
134 };
135 ATTRIBUTE_GROUPS(lp55xx_led);
136
lp55xx_set_brightness(struct led_classdev * cdev,enum led_brightness brightness)137 static void lp55xx_set_brightness(struct led_classdev *cdev,
138 enum led_brightness brightness)
139 {
140 struct lp55xx_led *led = cdev_to_lp55xx_led(cdev);
141
142 led->brightness = (u8)brightness;
143 schedule_work(&led->brightness_work);
144 }
145
lp55xx_init_led(struct lp55xx_led * led,struct lp55xx_chip * chip,int chan)146 static int lp55xx_init_led(struct lp55xx_led *led,
147 struct lp55xx_chip *chip, int chan)
148 {
149 struct lp55xx_platform_data *pdata = chip->pdata;
150 struct lp55xx_device_config *cfg = chip->cfg;
151 struct device *dev = &chip->cl->dev;
152 char name[32];
153 int ret;
154 int max_channel = cfg->max_channel;
155
156 if (chan >= max_channel) {
157 dev_err(dev, "invalid channel: %d / %d\n", chan, max_channel);
158 return -EINVAL;
159 }
160
161 if (pdata->led_config[chan].led_current == 0)
162 return 0;
163
164 led->led_current = pdata->led_config[chan].led_current;
165 led->max_current = pdata->led_config[chan].max_current;
166 led->chan_nr = pdata->led_config[chan].chan_nr;
167 led->cdev.default_trigger = pdata->led_config[chan].default_trigger;
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 led->cdev.groups = lp55xx_led_groups;
177
178 if (pdata->led_config[chan].name) {
179 led->cdev.name = pdata->led_config[chan].name;
180 } else {
181 snprintf(name, sizeof(name), "%s:channel%d",
182 pdata->label ? : chip->cl->name, chan);
183 led->cdev.name = name;
184 }
185
186 ret = led_classdev_register(dev, &led->cdev);
187 if (ret) {
188 dev_err(dev, "led register err: %d\n", ret);
189 return ret;
190 }
191
192 return 0;
193 }
194
lp55xx_firmware_loaded(const struct firmware * fw,void * context)195 static void lp55xx_firmware_loaded(const struct firmware *fw, void *context)
196 {
197 struct lp55xx_chip *chip = context;
198 struct device *dev = &chip->cl->dev;
199 enum lp55xx_engine_index idx = chip->engine_idx;
200
201 if (!fw) {
202 dev_err(dev, "firmware request failed\n");
203 return;
204 }
205
206 /* handling firmware data is chip dependent */
207 mutex_lock(&chip->lock);
208
209 chip->engines[idx - 1].mode = LP55XX_ENGINE_LOAD;
210 chip->fw = fw;
211 if (chip->cfg->firmware_cb)
212 chip->cfg->firmware_cb(chip);
213
214 mutex_unlock(&chip->lock);
215
216 /* firmware should be released for other channel use */
217 release_firmware(chip->fw);
218 chip->fw = NULL;
219 }
220
lp55xx_request_firmware(struct lp55xx_chip * chip)221 static int lp55xx_request_firmware(struct lp55xx_chip *chip)
222 {
223 const char *name = chip->cl->name;
224 struct device *dev = &chip->cl->dev;
225
226 return request_firmware_nowait(THIS_MODULE, false, name, dev,
227 GFP_KERNEL, chip, lp55xx_firmware_loaded);
228 }
229
lp55xx_show_engine_select(struct device * dev,struct device_attribute * attr,char * buf)230 static ssize_t lp55xx_show_engine_select(struct device *dev,
231 struct device_attribute *attr,
232 char *buf)
233 {
234 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
235 struct lp55xx_chip *chip = led->chip;
236
237 return sprintf(buf, "%d\n", chip->engine_idx);
238 }
239
lp55xx_store_engine_select(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)240 static ssize_t lp55xx_store_engine_select(struct device *dev,
241 struct device_attribute *attr,
242 const char *buf, size_t len)
243 {
244 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
245 struct lp55xx_chip *chip = led->chip;
246 unsigned long val;
247 int ret;
248
249 if (kstrtoul(buf, 0, &val))
250 return -EINVAL;
251
252 /* select the engine to be run */
253
254 switch (val) {
255 case LP55XX_ENGINE_1:
256 case LP55XX_ENGINE_2:
257 case LP55XX_ENGINE_3:
258 mutex_lock(&chip->lock);
259 chip->engine_idx = val;
260 ret = lp55xx_request_firmware(chip);
261 mutex_unlock(&chip->lock);
262 break;
263 default:
264 dev_err(dev, "%lu: invalid engine index. (1, 2, 3)\n", val);
265 return -EINVAL;
266 }
267
268 if (ret) {
269 dev_err(dev, "request firmware err: %d\n", ret);
270 return ret;
271 }
272
273 return len;
274 }
275
lp55xx_run_engine(struct lp55xx_chip * chip,bool start)276 static inline void lp55xx_run_engine(struct lp55xx_chip *chip, bool start)
277 {
278 if (chip->cfg->run_engine)
279 chip->cfg->run_engine(chip, start);
280 }
281
lp55xx_store_engine_run(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)282 static ssize_t lp55xx_store_engine_run(struct device *dev,
283 struct device_attribute *attr,
284 const char *buf, size_t len)
285 {
286 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
287 struct lp55xx_chip *chip = led->chip;
288 unsigned long val;
289
290 if (kstrtoul(buf, 0, &val))
291 return -EINVAL;
292
293 /* run or stop the selected engine */
294
295 if (val <= 0) {
296 lp55xx_run_engine(chip, false);
297 return len;
298 }
299
300 mutex_lock(&chip->lock);
301 lp55xx_run_engine(chip, true);
302 mutex_unlock(&chip->lock);
303
304 return len;
305 }
306
307 static DEVICE_ATTR(select_engine, S_IRUGO | S_IWUSR,
308 lp55xx_show_engine_select, lp55xx_store_engine_select);
309 static DEVICE_ATTR(run_engine, S_IWUSR, NULL, lp55xx_store_engine_run);
310
311 static struct attribute *lp55xx_engine_attributes[] = {
312 &dev_attr_select_engine.attr,
313 &dev_attr_run_engine.attr,
314 NULL,
315 };
316
317 static const struct attribute_group lp55xx_engine_attr_group = {
318 .attrs = lp55xx_engine_attributes,
319 };
320
lp55xx_write(struct lp55xx_chip * chip,u8 reg,u8 val)321 int lp55xx_write(struct lp55xx_chip *chip, u8 reg, u8 val)
322 {
323 return i2c_smbus_write_byte_data(chip->cl, reg, val);
324 }
325 EXPORT_SYMBOL_GPL(lp55xx_write);
326
lp55xx_read(struct lp55xx_chip * chip,u8 reg,u8 * val)327 int lp55xx_read(struct lp55xx_chip *chip, u8 reg, u8 *val)
328 {
329 s32 ret;
330
331 ret = i2c_smbus_read_byte_data(chip->cl, reg);
332 if (ret < 0)
333 return ret;
334
335 *val = ret;
336 return 0;
337 }
338 EXPORT_SYMBOL_GPL(lp55xx_read);
339
lp55xx_update_bits(struct lp55xx_chip * chip,u8 reg,u8 mask,u8 val)340 int lp55xx_update_bits(struct lp55xx_chip *chip, u8 reg, u8 mask, u8 val)
341 {
342 int ret;
343 u8 tmp;
344
345 ret = lp55xx_read(chip, reg, &tmp);
346 if (ret)
347 return ret;
348
349 tmp &= ~mask;
350 tmp |= val & mask;
351
352 return lp55xx_write(chip, reg, tmp);
353 }
354 EXPORT_SYMBOL_GPL(lp55xx_update_bits);
355
lp55xx_is_extclk_used(struct lp55xx_chip * chip)356 bool lp55xx_is_extclk_used(struct lp55xx_chip *chip)
357 {
358 struct clk *clk;
359 int err;
360
361 clk = devm_clk_get(&chip->cl->dev, "32k_clk");
362 if (IS_ERR(clk))
363 goto use_internal_clk;
364
365 err = clk_prepare_enable(clk);
366 if (err)
367 goto use_internal_clk;
368
369 if (clk_get_rate(clk) != LP55XX_CLK_32K) {
370 clk_disable_unprepare(clk);
371 goto use_internal_clk;
372 }
373
374 dev_info(&chip->cl->dev, "%dHz external clock used\n", LP55XX_CLK_32K);
375
376 chip->clk = clk;
377 return true;
378
379 use_internal_clk:
380 dev_info(&chip->cl->dev, "internal clock used\n");
381 return false;
382 }
383 EXPORT_SYMBOL_GPL(lp55xx_is_extclk_used);
384
lp55xx_init_device(struct lp55xx_chip * chip)385 int lp55xx_init_device(struct lp55xx_chip *chip)
386 {
387 struct lp55xx_platform_data *pdata;
388 struct lp55xx_device_config *cfg;
389 struct device *dev = &chip->cl->dev;
390 int ret = 0;
391
392 WARN_ON(!chip);
393
394 pdata = chip->pdata;
395 cfg = chip->cfg;
396
397 if (!pdata || !cfg)
398 return -EINVAL;
399
400 if (gpio_is_valid(pdata->enable_gpio)) {
401 ret = devm_gpio_request_one(dev, pdata->enable_gpio,
402 GPIOF_DIR_OUT, "lp5523_enable");
403 if (ret < 0) {
404 dev_err(dev, "could not acquire enable gpio (err=%d)\n",
405 ret);
406 goto err;
407 }
408
409 gpio_set_value(pdata->enable_gpio, 0);
410 usleep_range(1000, 2000); /* Keep enable down at least 1ms */
411 gpio_set_value(pdata->enable_gpio, 1);
412 usleep_range(1000, 2000); /* 500us abs min. */
413 }
414
415 lp55xx_reset_device(chip);
416
417 /*
418 * Exact value is not available. 10 - 20ms
419 * appears to be enough for reset.
420 */
421 usleep_range(10000, 20000);
422
423 ret = lp55xx_detect_device(chip);
424 if (ret) {
425 dev_err(dev, "device detection err: %d\n", ret);
426 goto err;
427 }
428
429 /* chip specific initialization */
430 ret = lp55xx_post_init_device(chip);
431 if (ret) {
432 dev_err(dev, "post init device err: %d\n", ret);
433 goto err_post_init;
434 }
435
436 return 0;
437
438 err_post_init:
439 lp55xx_deinit_device(chip);
440 err:
441 return ret;
442 }
443 EXPORT_SYMBOL_GPL(lp55xx_init_device);
444
lp55xx_deinit_device(struct lp55xx_chip * chip)445 void lp55xx_deinit_device(struct lp55xx_chip *chip)
446 {
447 struct lp55xx_platform_data *pdata = chip->pdata;
448
449 if (chip->clk)
450 clk_disable_unprepare(chip->clk);
451
452 if (gpio_is_valid(pdata->enable_gpio))
453 gpio_set_value(pdata->enable_gpio, 0);
454 }
455 EXPORT_SYMBOL_GPL(lp55xx_deinit_device);
456
lp55xx_register_leds(struct lp55xx_led * led,struct lp55xx_chip * chip)457 int lp55xx_register_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
458 {
459 struct lp55xx_platform_data *pdata = chip->pdata;
460 struct lp55xx_device_config *cfg = chip->cfg;
461 int num_channels = pdata->num_channels;
462 struct lp55xx_led *each;
463 u8 led_current;
464 int ret;
465 int i;
466
467 if (!cfg->brightness_work_fn) {
468 dev_err(&chip->cl->dev, "empty brightness configuration\n");
469 return -EINVAL;
470 }
471
472 for (i = 0; i < num_channels; i++) {
473
474 /* do not initialize channels that are not connected */
475 if (pdata->led_config[i].led_current == 0)
476 continue;
477
478 led_current = pdata->led_config[i].led_current;
479 each = led + i;
480 ret = lp55xx_init_led(each, chip, i);
481 if (ret)
482 goto err_init_led;
483
484 INIT_WORK(&each->brightness_work, cfg->brightness_work_fn);
485
486 chip->num_leds++;
487 each->chip = chip;
488
489 /* setting led current at each channel */
490 if (cfg->set_led_current)
491 cfg->set_led_current(each, led_current);
492 }
493
494 return 0;
495
496 err_init_led:
497 lp55xx_unregister_leds(led, chip);
498 return ret;
499 }
500 EXPORT_SYMBOL_GPL(lp55xx_register_leds);
501
lp55xx_unregister_leds(struct lp55xx_led * led,struct lp55xx_chip * chip)502 void lp55xx_unregister_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
503 {
504 int i;
505 struct lp55xx_led *each;
506
507 for (i = 0; i < chip->num_leds; i++) {
508 each = led + i;
509 led_classdev_unregister(&each->cdev);
510 flush_work(&each->brightness_work);
511 }
512 }
513 EXPORT_SYMBOL_GPL(lp55xx_unregister_leds);
514
lp55xx_register_sysfs(struct lp55xx_chip * chip)515 int lp55xx_register_sysfs(struct lp55xx_chip *chip)
516 {
517 struct device *dev = &chip->cl->dev;
518 struct lp55xx_device_config *cfg = chip->cfg;
519 int ret;
520
521 if (!cfg->run_engine || !cfg->firmware_cb)
522 goto dev_specific_attrs;
523
524 ret = sysfs_create_group(&dev->kobj, &lp55xx_engine_attr_group);
525 if (ret)
526 return ret;
527
528 dev_specific_attrs:
529 return cfg->dev_attr_group ?
530 sysfs_create_group(&dev->kobj, cfg->dev_attr_group) : 0;
531 }
532 EXPORT_SYMBOL_GPL(lp55xx_register_sysfs);
533
lp55xx_unregister_sysfs(struct lp55xx_chip * chip)534 void lp55xx_unregister_sysfs(struct lp55xx_chip *chip)
535 {
536 struct device *dev = &chip->cl->dev;
537 struct lp55xx_device_config *cfg = chip->cfg;
538
539 if (cfg->dev_attr_group)
540 sysfs_remove_group(&dev->kobj, cfg->dev_attr_group);
541
542 sysfs_remove_group(&dev->kobj, &lp55xx_engine_attr_group);
543 }
544 EXPORT_SYMBOL_GPL(lp55xx_unregister_sysfs);
545
lp55xx_of_populate_pdata(struct device * dev,struct device_node * np)546 struct lp55xx_platform_data *lp55xx_of_populate_pdata(struct device *dev,
547 struct device_node *np)
548 {
549 struct device_node *child;
550 struct lp55xx_platform_data *pdata;
551 struct lp55xx_led_config *cfg;
552 int num_channels;
553 int i = 0;
554
555 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
556 if (!pdata)
557 return ERR_PTR(-ENOMEM);
558
559 num_channels = of_get_child_count(np);
560 if (num_channels == 0) {
561 dev_err(dev, "no LED channels\n");
562 return ERR_PTR(-EINVAL);
563 }
564
565 cfg = devm_kzalloc(dev, sizeof(*cfg) * num_channels, GFP_KERNEL);
566 if (!cfg)
567 return ERR_PTR(-ENOMEM);
568
569 pdata->led_config = &cfg[0];
570 pdata->num_channels = num_channels;
571
572 for_each_child_of_node(np, child) {
573 cfg[i].chan_nr = i;
574
575 of_property_read_string(child, "chan-name", &cfg[i].name);
576 of_property_read_u8(child, "led-cur", &cfg[i].led_current);
577 of_property_read_u8(child, "max-cur", &cfg[i].max_current);
578 cfg[i].default_trigger =
579 of_get_property(child, "linux,default-trigger", NULL);
580
581 i++;
582 }
583
584 of_property_read_string(np, "label", &pdata->label);
585 of_property_read_u8(np, "clock-mode", &pdata->clock_mode);
586
587 pdata->enable_gpio = of_get_named_gpio(np, "enable-gpio", 0);
588
589 /* LP8501 specific */
590 of_property_read_u8(np, "pwr-sel", (u8 *)&pdata->pwr_sel);
591
592 return pdata;
593 }
594 EXPORT_SYMBOL_GPL(lp55xx_of_populate_pdata);
595
596 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
597 MODULE_DESCRIPTION("LP55xx Common Driver");
598 MODULE_LICENSE("GPL");
599