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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
31static struct lp55xx_led *cdev_to_lp55xx_led(struct led_classdev *cdev)
32{
33 return container_of(cdev, struct lp55xx_led, cdev);
34}
35
36static struct lp55xx_led *dev_to_lp55xx_led(struct device *dev)
37{
38 return cdev_to_lp55xx_led(dev_get_drvdata(dev));
39}
40
41static 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
51static 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
74static 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
84static 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
93static 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
117static 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
126static DEVICE_ATTR(led_current, S_IRUGO | S_IWUSR, lp55xx_show_current,
127 lp55xx_store_current);
128static DEVICE_ATTR(max_current, S_IRUGO , lp55xx_show_max_current, NULL);
129
130static struct attribute *lp55xx_led_attrs[] = {
131 &dev_attr_led_current.attr,
132 &dev_attr_max_current.attr,
133 NULL,
134};
135ATTRIBUTE_GROUPS(lp55xx_led);
136
137static int lp55xx_set_brightness(struct led_classdev *cdev,
138 enum led_brightness brightness)
139{
140 struct lp55xx_led *led = cdev_to_lp55xx_led(cdev);
141 struct lp55xx_device_config *cfg = led->chip->cfg;
142
143 led->brightness = (u8)brightness;
144 return cfg->brightness_fn(led);
145}
146
147static 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 led->cdev.default_trigger = pdata->led_config[chan].default_trigger;
169
170 if (led->chan_nr >= max_channel) {
171 dev_err(dev, "Use channel numbers between 0 and %d\n",
172 max_channel - 1);
173 return -EINVAL;
174 }
175
176 led->cdev.brightness_set_blocking = lp55xx_set_brightness;
177 led->cdev.groups = lp55xx_led_groups;
178
179 if (pdata->led_config[chan].name) {
180 led->cdev.name = pdata->led_config[chan].name;
181 } else {
182 snprintf(name, sizeof(name), "%s:channel%d",
183 pdata->label ? : chip->cl->name, chan);
184 led->cdev.name = name;
185 }
186
187 ret = led_classdev_register(dev, &led->cdev);
188 if (ret) {
189 dev_err(dev, "led register err: %d\n", ret);
190 return ret;
191 }
192
193 return 0;
194}
195
196static void lp55xx_firmware_loaded(const struct firmware *fw, void *context)
197{
198 struct lp55xx_chip *chip = context;
199 struct device *dev = &chip->cl->dev;
200 enum lp55xx_engine_index idx = chip->engine_idx;
201
202 if (!fw) {
203 dev_err(dev, "firmware request failed\n");
204 goto out;
205 }
206
207 /* handling firmware data is chip dependent */
208 mutex_lock(&chip->lock);
209
210 chip->engines[idx - 1].mode = LP55XX_ENGINE_LOAD;
211 chip->fw = fw;
212 if (chip->cfg->firmware_cb)
213 chip->cfg->firmware_cb(chip);
214
215 mutex_unlock(&chip->lock);
216
217out:
218 /* firmware should be released for other channel use */
219 release_firmware(chip->fw);
220}
221
222static int lp55xx_request_firmware(struct lp55xx_chip *chip)
223{
224 const char *name = chip->cl->name;
225 struct device *dev = &chip->cl->dev;
226
227 return request_firmware_nowait(THIS_MODULE, false, name, dev,
228 GFP_KERNEL, chip, lp55xx_firmware_loaded);
229}
230
231static ssize_t lp55xx_show_engine_select(struct device *dev,
232 struct device_attribute *attr,
233 char *buf)
234{
235 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
236 struct lp55xx_chip *chip = led->chip;
237
238 return sprintf(buf, "%d\n", chip->engine_idx);
239}
240
241static ssize_t lp55xx_store_engine_select(struct device *dev,
242 struct device_attribute *attr,
243 const char *buf, size_t len)
244{
245 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
246 struct lp55xx_chip *chip = led->chip;
247 unsigned long val;
248 int ret;
249
250 if (kstrtoul(buf, 0, &val))
251 return -EINVAL;
252
253 /* select the engine to be run */
254
255 switch (val) {
256 case LP55XX_ENGINE_1:
257 case LP55XX_ENGINE_2:
258 case LP55XX_ENGINE_3:
259 mutex_lock(&chip->lock);
260 chip->engine_idx = val;
261 ret = lp55xx_request_firmware(chip);
262 mutex_unlock(&chip->lock);
263 break;
264 default:
265 dev_err(dev, "%lu: invalid engine index. (1, 2, 3)\n", val);
266 return -EINVAL;
267 }
268
269 if (ret) {
270 dev_err(dev, "request firmware err: %d\n", ret);
271 return ret;
272 }
273
274 return len;
275}
276
277static inline void lp55xx_run_engine(struct lp55xx_chip *chip, bool start)
278{
279 if (chip->cfg->run_engine)
280 chip->cfg->run_engine(chip, start);
281}
282
283static ssize_t lp55xx_store_engine_run(struct device *dev,
284 struct device_attribute *attr,
285 const char *buf, size_t len)
286{
287 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
288 struct lp55xx_chip *chip = led->chip;
289 unsigned long val;
290
291 if (kstrtoul(buf, 0, &val))
292 return -EINVAL;
293
294 /* run or stop the selected engine */
295
296 if (val <= 0) {
297 lp55xx_run_engine(chip, false);
298 return len;
299 }
300
301 mutex_lock(&chip->lock);
302 lp55xx_run_engine(chip, true);
303 mutex_unlock(&chip->lock);
304
305 return len;
306}
307
308static DEVICE_ATTR(select_engine, S_IRUGO | S_IWUSR,
309 lp55xx_show_engine_select, lp55xx_store_engine_select);
310static DEVICE_ATTR(run_engine, S_IWUSR, NULL, lp55xx_store_engine_run);
311
312static struct attribute *lp55xx_engine_attributes[] = {
313 &dev_attr_select_engine.attr,
314 &dev_attr_run_engine.attr,
315 NULL,
316};
317
318static const struct attribute_group lp55xx_engine_attr_group = {
319 .attrs = lp55xx_engine_attributes,
320};
321
322int lp55xx_write(struct lp55xx_chip *chip, u8 reg, u8 val)
323{
324 return i2c_smbus_write_byte_data(chip->cl, reg, val);
325}
326EXPORT_SYMBOL_GPL(lp55xx_write);
327
328int lp55xx_read(struct lp55xx_chip *chip, u8 reg, u8 *val)
329{
330 s32 ret;
331
332 ret = i2c_smbus_read_byte_data(chip->cl, reg);
333 if (ret < 0)
334 return ret;
335
336 *val = ret;
337 return 0;
338}
339EXPORT_SYMBOL_GPL(lp55xx_read);
340
341int lp55xx_update_bits(struct lp55xx_chip *chip, u8 reg, u8 mask, u8 val)
342{
343 int ret;
344 u8 tmp;
345
346 ret = lp55xx_read(chip, reg, &tmp);
347 if (ret)
348 return ret;
349
350 tmp &= ~mask;
351 tmp |= val & mask;
352
353 return lp55xx_write(chip, reg, tmp);
354}
355EXPORT_SYMBOL_GPL(lp55xx_update_bits);
356
357bool lp55xx_is_extclk_used(struct lp55xx_chip *chip)
358{
359 struct clk *clk;
360 int err;
361
362 clk = devm_clk_get(&chip->cl->dev, "32k_clk");
363 if (IS_ERR(clk))
364 goto use_internal_clk;
365
366 err = clk_prepare_enable(clk);
367 if (err)
368 goto use_internal_clk;
369
370 if (clk_get_rate(clk) != LP55XX_CLK_32K) {
371 clk_disable_unprepare(clk);
372 goto use_internal_clk;
373 }
374
375 dev_info(&chip->cl->dev, "%dHz external clock used\n", LP55XX_CLK_32K);
376
377 chip->clk = clk;
378 return true;
379
380use_internal_clk:
381 dev_info(&chip->cl->dev, "internal clock used\n");
382 return false;
383}
384EXPORT_SYMBOL_GPL(lp55xx_is_extclk_used);
385
386int lp55xx_init_device(struct lp55xx_chip *chip)
387{
388 struct lp55xx_platform_data *pdata;
389 struct lp55xx_device_config *cfg;
390 struct device *dev = &chip->cl->dev;
391 int ret = 0;
392
393 WARN_ON(!chip);
394
395 pdata = chip->pdata;
396 cfg = chip->cfg;
397
398 if (!pdata || !cfg)
399 return -EINVAL;
400
401 if (gpio_is_valid(pdata->enable_gpio)) {
402 ret = devm_gpio_request_one(dev, pdata->enable_gpio,
403 GPIOF_DIR_OUT, "lp5523_enable");
404 if (ret < 0) {
405 dev_err(dev, "could not acquire enable gpio (err=%d)\n",
406 ret);
407 goto err;
408 }
409
410 gpio_set_value(pdata->enable_gpio, 0);
411 usleep_range(1000, 2000); /* Keep enable down at least 1ms */
412 gpio_set_value(pdata->enable_gpio, 1);
413 usleep_range(1000, 2000); /* 500us abs min. */
414 }
415
416 lp55xx_reset_device(chip);
417
418 /*
419 * Exact value is not available. 10 - 20ms
420 * appears to be enough for reset.
421 */
422 usleep_range(10000, 20000);
423
424 ret = lp55xx_detect_device(chip);
425 if (ret) {
426 dev_err(dev, "device detection err: %d\n", ret);
427 goto err;
428 }
429
430 /* chip specific initialization */
431 ret = lp55xx_post_init_device(chip);
432 if (ret) {
433 dev_err(dev, "post init device err: %d\n", ret);
434 goto err_post_init;
435 }
436
437 return 0;
438
439err_post_init:
440 lp55xx_deinit_device(chip);
441err:
442 return ret;
443}
444EXPORT_SYMBOL_GPL(lp55xx_init_device);
445
446void lp55xx_deinit_device(struct lp55xx_chip *chip)
447{
448 struct lp55xx_platform_data *pdata = chip->pdata;
449
450 if (chip->clk)
451 clk_disable_unprepare(chip->clk);
452
453 if (gpio_is_valid(pdata->enable_gpio))
454 gpio_set_value(pdata->enable_gpio, 0);
455}
456EXPORT_SYMBOL_GPL(lp55xx_deinit_device);
457
458int lp55xx_register_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
459{
460 struct lp55xx_platform_data *pdata = chip->pdata;
461 struct lp55xx_device_config *cfg = chip->cfg;
462 int num_channels = pdata->num_channels;
463 struct lp55xx_led *each;
464 u8 led_current;
465 int ret;
466 int i;
467
468 if (!cfg->brightness_fn) {
469 dev_err(&chip->cl->dev, "empty brightness configuration\n");
470 return -EINVAL;
471 }
472
473 for (i = 0; i < num_channels; i++) {
474
475 /* do not initialize channels that are not connected */
476 if (pdata->led_config[i].led_current == 0)
477 continue;
478
479 led_current = pdata->led_config[i].led_current;
480 each = led + i;
481 ret = lp55xx_init_led(each, chip, i);
482 if (ret)
483 goto err_init_led;
484
485 chip->num_leds++;
486 each->chip = chip;
487
488 /* setting led current at each channel */
489 if (cfg->set_led_current)
490 cfg->set_led_current(each, led_current);
491 }
492
493 return 0;
494
495err_init_led:
496 lp55xx_unregister_leds(led, chip);
497 return ret;
498}
499EXPORT_SYMBOL_GPL(lp55xx_register_leds);
500
501void lp55xx_unregister_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
502{
503 int i;
504 struct lp55xx_led *each;
505
506 for (i = 0; i < chip->num_leds; i++) {
507 each = led + i;
508 led_classdev_unregister(&each->cdev);
509 }
510}
511EXPORT_SYMBOL_GPL(lp55xx_unregister_leds);
512
513int lp55xx_register_sysfs(struct lp55xx_chip *chip)
514{
515 struct device *dev = &chip->cl->dev;
516 struct lp55xx_device_config *cfg = chip->cfg;
517 int ret;
518
519 if (!cfg->run_engine || !cfg->firmware_cb)
520 goto dev_specific_attrs;
521
522 ret = sysfs_create_group(&dev->kobj, &lp55xx_engine_attr_group);
523 if (ret)
524 return ret;
525
526dev_specific_attrs:
527 return cfg->dev_attr_group ?
528 sysfs_create_group(&dev->kobj, cfg->dev_attr_group) : 0;
529}
530EXPORT_SYMBOL_GPL(lp55xx_register_sysfs);
531
532void lp55xx_unregister_sysfs(struct lp55xx_chip *chip)
533{
534 struct device *dev = &chip->cl->dev;
535 struct lp55xx_device_config *cfg = chip->cfg;
536
537 if (cfg->dev_attr_group)
538 sysfs_remove_group(&dev->kobj, cfg->dev_attr_group);
539
540 sysfs_remove_group(&dev->kobj, &lp55xx_engine_attr_group);
541}
542EXPORT_SYMBOL_GPL(lp55xx_unregister_sysfs);
543
544struct lp55xx_platform_data *lp55xx_of_populate_pdata(struct device *dev,
545 struct device_node *np)
546{
547 struct device_node *child;
548 struct lp55xx_platform_data *pdata;
549 struct lp55xx_led_config *cfg;
550 int num_channels;
551 int i = 0;
552
553 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
554 if (!pdata)
555 return ERR_PTR(-ENOMEM);
556
557 num_channels = of_get_child_count(np);
558 if (num_channels == 0) {
559 dev_err(dev, "no LED channels\n");
560 return ERR_PTR(-EINVAL);
561 }
562
563 cfg = devm_kzalloc(dev, sizeof(*cfg) * num_channels, GFP_KERNEL);
564 if (!cfg)
565 return ERR_PTR(-ENOMEM);
566
567 pdata->led_config = &cfg[0];
568 pdata->num_channels = num_channels;
569
570 for_each_child_of_node(np, child) {
571 cfg[i].chan_nr = i;
572
573 of_property_read_string(child, "chan-name", &cfg[i].name);
574 of_property_read_u8(child, "led-cur", &cfg[i].led_current);
575 of_property_read_u8(child, "max-cur", &cfg[i].max_current);
576 cfg[i].default_trigger =
577 of_get_property(child, "linux,default-trigger", NULL);
578
579 i++;
580 }
581
582 of_property_read_string(np, "label", &pdata->label);
583 of_property_read_u8(np, "clock-mode", &pdata->clock_mode);
584
585 pdata->enable_gpio = of_get_named_gpio(np, "enable-gpio", 0);
586
587 /* LP8501 specific */
588 of_property_read_u8(np, "pwr-sel", (u8 *)&pdata->pwr_sel);
589
590 return pdata;
591}
592EXPORT_SYMBOL_GPL(lp55xx_of_populate_pdata);
593
594MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
595MODULE_DESCRIPTION("LP55xx Common Driver");
596MODULE_LICENSE("GPL");