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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * LP5521/LP5523/LP55231/LP5562 Common Driver
4 *
5 * Copyright 2012 Texas Instruments
6 *
7 * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
8 *
9 * Derived from leds-lp5521.c, leds-lp5523.c
10 */
11
12#include <linux/clk.h>
13#include <linux/delay.h>
14#include <linux/firmware.h>
15#include <linux/i2c.h>
16#include <linux/leds.h>
17#include <linux/module.h>
18#include <linux/platform_data/leds-lp55xx.h>
19#include <linux/slab.h>
20#include <linux/gpio.h>
21#include <linux/of_gpio.h>
22
23#include "leds-lp55xx-common.h"
24
25/* External clock rate */
26#define LP55XX_CLK_32K 32768
27
28static struct lp55xx_led *cdev_to_lp55xx_led(struct led_classdev *cdev)
29{
30 return container_of(cdev, struct lp55xx_led, cdev);
31}
32
33static struct lp55xx_led *dev_to_lp55xx_led(struct device *dev)
34{
35 return cdev_to_lp55xx_led(dev_get_drvdata(dev));
36}
37
38static void lp55xx_reset_device(struct lp55xx_chip *chip)
39{
40 struct lp55xx_device_config *cfg = chip->cfg;
41 u8 addr = cfg->reset.addr;
42 u8 val = cfg->reset.val;
43
44 /* no error checking here because no ACK from the device after reset */
45 lp55xx_write(chip, addr, val);
46}
47
48static int lp55xx_detect_device(struct lp55xx_chip *chip)
49{
50 struct lp55xx_device_config *cfg = chip->cfg;
51 u8 addr = cfg->enable.addr;
52 u8 val = cfg->enable.val;
53 int ret;
54
55 ret = lp55xx_write(chip, addr, val);
56 if (ret)
57 return ret;
58
59 usleep_range(1000, 2000);
60
61 ret = lp55xx_read(chip, addr, &val);
62 if (ret)
63 return ret;
64
65 if (val != cfg->enable.val)
66 return -ENODEV;
67
68 return 0;
69}
70
71static int lp55xx_post_init_device(struct lp55xx_chip *chip)
72{
73 struct lp55xx_device_config *cfg = chip->cfg;
74
75 if (!cfg->post_init_device)
76 return 0;
77
78 return cfg->post_init_device(chip);
79}
80
81static ssize_t lp55xx_show_current(struct device *dev,
82 struct device_attribute *attr,
83 char *buf)
84{
85 struct lp55xx_led *led = dev_to_lp55xx_led(dev);
86
87 return scnprintf(buf, PAGE_SIZE, "%d\n", led->led_current);
88}
89
90static ssize_t lp55xx_store_current(struct device *dev,
91 struct device_attribute *attr,
92 const char *buf, size_t len)
93{
94 struct lp55xx_led *led = dev_to_lp55xx_led(dev);
95 struct lp55xx_chip *chip = led->chip;
96 unsigned long curr;
97
98 if (kstrtoul(buf, 0, &curr))
99 return -EINVAL;
100
101 if (curr > led->max_current)
102 return -EINVAL;
103
104 if (!chip->cfg->set_led_current)
105 return len;
106
107 mutex_lock(&chip->lock);
108 chip->cfg->set_led_current(led, (u8)curr);
109 mutex_unlock(&chip->lock);
110
111 return len;
112}
113
114static ssize_t lp55xx_show_max_current(struct device *dev,
115 struct device_attribute *attr,
116 char *buf)
117{
118 struct lp55xx_led *led = dev_to_lp55xx_led(dev);
119
120 return scnprintf(buf, PAGE_SIZE, "%d\n", led->max_current);
121}
122
123static DEVICE_ATTR(led_current, S_IRUGO | S_IWUSR, lp55xx_show_current,
124 lp55xx_store_current);
125static DEVICE_ATTR(max_current, S_IRUGO , lp55xx_show_max_current, NULL);
126
127static struct attribute *lp55xx_led_attrs[] = {
128 &dev_attr_led_current.attr,
129 &dev_attr_max_current.attr,
130 NULL,
131};
132ATTRIBUTE_GROUPS(lp55xx_led);
133
134static int lp55xx_set_brightness(struct led_classdev *cdev,
135 enum led_brightness brightness)
136{
137 struct lp55xx_led *led = cdev_to_lp55xx_led(cdev);
138 struct lp55xx_device_config *cfg = led->chip->cfg;
139
140 led->brightness = (u8)brightness;
141 return cfg->brightness_fn(led);
142}
143
144static int lp55xx_init_led(struct lp55xx_led *led,
145 struct lp55xx_chip *chip, int chan)
146{
147 struct lp55xx_platform_data *pdata = chip->pdata;
148 struct lp55xx_device_config *cfg = chip->cfg;
149 struct device *dev = &chip->cl->dev;
150 char name[32];
151 int ret;
152 int max_channel = cfg->max_channel;
153
154 if (chan >= max_channel) {
155 dev_err(dev, "invalid channel: %d / %d\n", chan, max_channel);
156 return -EINVAL;
157 }
158
159 if (pdata->led_config[chan].led_current == 0)
160 return 0;
161
162 led->led_current = pdata->led_config[chan].led_current;
163 led->max_current = pdata->led_config[chan].max_current;
164 led->chan_nr = pdata->led_config[chan].chan_nr;
165 led->cdev.default_trigger = pdata->led_config[chan].default_trigger;
166
167 if (led->chan_nr >= max_channel) {
168 dev_err(dev, "Use channel numbers between 0 and %d\n",
169 max_channel - 1);
170 return -EINVAL;
171 }
172
173 led->cdev.brightness_set_blocking = lp55xx_set_brightness;
174 led->cdev.groups = lp55xx_led_groups;
175
176 if (pdata->led_config[chan].name) {
177 led->cdev.name = pdata->led_config[chan].name;
178 } else {
179 snprintf(name, sizeof(name), "%s:channel%d",
180 pdata->label ? : chip->cl->name, chan);
181 led->cdev.name = name;
182 }
183
184 ret = led_classdev_register(dev, &led->cdev);
185 if (ret) {
186 dev_err(dev, "led register err: %d\n", ret);
187 return ret;
188 }
189
190 return 0;
191}
192
193static void lp55xx_firmware_loaded(const struct firmware *fw, void *context)
194{
195 struct lp55xx_chip *chip = context;
196 struct device *dev = &chip->cl->dev;
197 enum lp55xx_engine_index idx = chip->engine_idx;
198
199 if (!fw) {
200 dev_err(dev, "firmware request failed\n");
201 return;
202 }
203
204 /* handling firmware data is chip dependent */
205 mutex_lock(&chip->lock);
206
207 chip->engines[idx - 1].mode = LP55XX_ENGINE_LOAD;
208 chip->fw = fw;
209 if (chip->cfg->firmware_cb)
210 chip->cfg->firmware_cb(chip);
211
212 mutex_unlock(&chip->lock);
213
214 /* firmware should be released for other channel use */
215 release_firmware(chip->fw);
216 chip->fw = NULL;
217}
218
219static int lp55xx_request_firmware(struct lp55xx_chip *chip)
220{
221 const char *name = chip->cl->name;
222 struct device *dev = &chip->cl->dev;
223
224 return request_firmware_nowait(THIS_MODULE, false, name, dev,
225 GFP_KERNEL, chip, lp55xx_firmware_loaded);
226}
227
228static ssize_t lp55xx_show_engine_select(struct device *dev,
229 struct device_attribute *attr,
230 char *buf)
231{
232 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
233 struct lp55xx_chip *chip = led->chip;
234
235 return sprintf(buf, "%d\n", chip->engine_idx);
236}
237
238static ssize_t lp55xx_store_engine_select(struct device *dev,
239 struct device_attribute *attr,
240 const char *buf, size_t len)
241{
242 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
243 struct lp55xx_chip *chip = led->chip;
244 unsigned long val;
245 int ret;
246
247 if (kstrtoul(buf, 0, &val))
248 return -EINVAL;
249
250 /* select the engine to be run */
251
252 switch (val) {
253 case LP55XX_ENGINE_1:
254 case LP55XX_ENGINE_2:
255 case LP55XX_ENGINE_3:
256 mutex_lock(&chip->lock);
257 chip->engine_idx = val;
258 ret = lp55xx_request_firmware(chip);
259 mutex_unlock(&chip->lock);
260 break;
261 default:
262 dev_err(dev, "%lu: invalid engine index. (1, 2, 3)\n", val);
263 return -EINVAL;
264 }
265
266 if (ret) {
267 dev_err(dev, "request firmware err: %d\n", ret);
268 return ret;
269 }
270
271 return len;
272}
273
274static inline void lp55xx_run_engine(struct lp55xx_chip *chip, bool start)
275{
276 if (chip->cfg->run_engine)
277 chip->cfg->run_engine(chip, start);
278}
279
280static ssize_t lp55xx_store_engine_run(struct device *dev,
281 struct device_attribute *attr,
282 const char *buf, size_t len)
283{
284 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
285 struct lp55xx_chip *chip = led->chip;
286 unsigned long val;
287
288 if (kstrtoul(buf, 0, &val))
289 return -EINVAL;
290
291 /* run or stop the selected engine */
292
293 if (val <= 0) {
294 lp55xx_run_engine(chip, false);
295 return len;
296 }
297
298 mutex_lock(&chip->lock);
299 lp55xx_run_engine(chip, true);
300 mutex_unlock(&chip->lock);
301
302 return len;
303}
304
305static DEVICE_ATTR(select_engine, S_IRUGO | S_IWUSR,
306 lp55xx_show_engine_select, lp55xx_store_engine_select);
307static DEVICE_ATTR(run_engine, S_IWUSR, NULL, lp55xx_store_engine_run);
308
309static struct attribute *lp55xx_engine_attributes[] = {
310 &dev_attr_select_engine.attr,
311 &dev_attr_run_engine.attr,
312 NULL,
313};
314
315static const struct attribute_group lp55xx_engine_attr_group = {
316 .attrs = lp55xx_engine_attributes,
317};
318
319int lp55xx_write(struct lp55xx_chip *chip, u8 reg, u8 val)
320{
321 return i2c_smbus_write_byte_data(chip->cl, reg, val);
322}
323EXPORT_SYMBOL_GPL(lp55xx_write);
324
325int lp55xx_read(struct lp55xx_chip *chip, u8 reg, u8 *val)
326{
327 s32 ret;
328
329 ret = i2c_smbus_read_byte_data(chip->cl, reg);
330 if (ret < 0)
331 return ret;
332
333 *val = ret;
334 return 0;
335}
336EXPORT_SYMBOL_GPL(lp55xx_read);
337
338int lp55xx_update_bits(struct lp55xx_chip *chip, u8 reg, u8 mask, u8 val)
339{
340 int ret;
341 u8 tmp;
342
343 ret = lp55xx_read(chip, reg, &tmp);
344 if (ret)
345 return ret;
346
347 tmp &= ~mask;
348 tmp |= val & mask;
349
350 return lp55xx_write(chip, reg, tmp);
351}
352EXPORT_SYMBOL_GPL(lp55xx_update_bits);
353
354bool lp55xx_is_extclk_used(struct lp55xx_chip *chip)
355{
356 struct clk *clk;
357 int err;
358
359 clk = devm_clk_get(&chip->cl->dev, "32k_clk");
360 if (IS_ERR(clk))
361 goto use_internal_clk;
362
363 err = clk_prepare_enable(clk);
364 if (err)
365 goto use_internal_clk;
366
367 if (clk_get_rate(clk) != LP55XX_CLK_32K) {
368 clk_disable_unprepare(clk);
369 goto use_internal_clk;
370 }
371
372 dev_info(&chip->cl->dev, "%dHz external clock used\n", LP55XX_CLK_32K);
373
374 chip->clk = clk;
375 return true;
376
377use_internal_clk:
378 dev_info(&chip->cl->dev, "internal clock used\n");
379 return false;
380}
381EXPORT_SYMBOL_GPL(lp55xx_is_extclk_used);
382
383int lp55xx_init_device(struct lp55xx_chip *chip)
384{
385 struct lp55xx_platform_data *pdata;
386 struct lp55xx_device_config *cfg;
387 struct device *dev = &chip->cl->dev;
388 int ret = 0;
389
390 WARN_ON(!chip);
391
392 pdata = chip->pdata;
393 cfg = chip->cfg;
394
395 if (!pdata || !cfg)
396 return -EINVAL;
397
398 if (gpio_is_valid(pdata->enable_gpio)) {
399 ret = devm_gpio_request_one(dev, pdata->enable_gpio,
400 GPIOF_DIR_OUT, "lp5523_enable");
401 if (ret < 0) {
402 dev_err(dev, "could not acquire enable gpio (err=%d)\n",
403 ret);
404 goto err;
405 }
406
407 gpio_set_value(pdata->enable_gpio, 0);
408 usleep_range(1000, 2000); /* Keep enable down at least 1ms */
409 gpio_set_value(pdata->enable_gpio, 1);
410 usleep_range(1000, 2000); /* 500us abs min. */
411 }
412
413 lp55xx_reset_device(chip);
414
415 /*
416 * Exact value is not available. 10 - 20ms
417 * appears to be enough for reset.
418 */
419 usleep_range(10000, 20000);
420
421 ret = lp55xx_detect_device(chip);
422 if (ret) {
423 dev_err(dev, "device detection err: %d\n", ret);
424 goto err;
425 }
426
427 /* chip specific initialization */
428 ret = lp55xx_post_init_device(chip);
429 if (ret) {
430 dev_err(dev, "post init device err: %d\n", ret);
431 goto err_post_init;
432 }
433
434 return 0;
435
436err_post_init:
437 lp55xx_deinit_device(chip);
438err:
439 return ret;
440}
441EXPORT_SYMBOL_GPL(lp55xx_init_device);
442
443void lp55xx_deinit_device(struct lp55xx_chip *chip)
444{
445 struct lp55xx_platform_data *pdata = chip->pdata;
446
447 if (chip->clk)
448 clk_disable_unprepare(chip->clk);
449
450 if (gpio_is_valid(pdata->enable_gpio))
451 gpio_set_value(pdata->enable_gpio, 0);
452}
453EXPORT_SYMBOL_GPL(lp55xx_deinit_device);
454
455int lp55xx_register_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
456{
457 struct lp55xx_platform_data *pdata = chip->pdata;
458 struct lp55xx_device_config *cfg = chip->cfg;
459 int num_channels = pdata->num_channels;
460 struct lp55xx_led *each;
461 u8 led_current;
462 int ret;
463 int i;
464
465 if (!cfg->brightness_fn) {
466 dev_err(&chip->cl->dev, "empty brightness configuration\n");
467 return -EINVAL;
468 }
469
470 for (i = 0; i < num_channels; i++) {
471
472 /* do not initialize channels that are not connected */
473 if (pdata->led_config[i].led_current == 0)
474 continue;
475
476 led_current = pdata->led_config[i].led_current;
477 each = led + i;
478 ret = lp55xx_init_led(each, chip, i);
479 if (ret)
480 goto err_init_led;
481
482 chip->num_leds++;
483 each->chip = chip;
484
485 /* setting led current at each channel */
486 if (cfg->set_led_current)
487 cfg->set_led_current(each, led_current);
488 }
489
490 return 0;
491
492err_init_led:
493 lp55xx_unregister_leds(led, chip);
494 return ret;
495}
496EXPORT_SYMBOL_GPL(lp55xx_register_leds);
497
498void lp55xx_unregister_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
499{
500 int i;
501 struct lp55xx_led *each;
502
503 for (i = 0; i < chip->num_leds; i++) {
504 each = led + i;
505 led_classdev_unregister(&each->cdev);
506 }
507}
508EXPORT_SYMBOL_GPL(lp55xx_unregister_leds);
509
510int lp55xx_register_sysfs(struct lp55xx_chip *chip)
511{
512 struct device *dev = &chip->cl->dev;
513 struct lp55xx_device_config *cfg = chip->cfg;
514 int ret;
515
516 if (!cfg->run_engine || !cfg->firmware_cb)
517 goto dev_specific_attrs;
518
519 ret = sysfs_create_group(&dev->kobj, &lp55xx_engine_attr_group);
520 if (ret)
521 return ret;
522
523dev_specific_attrs:
524 return cfg->dev_attr_group ?
525 sysfs_create_group(&dev->kobj, cfg->dev_attr_group) : 0;
526}
527EXPORT_SYMBOL_GPL(lp55xx_register_sysfs);
528
529void lp55xx_unregister_sysfs(struct lp55xx_chip *chip)
530{
531 struct device *dev = &chip->cl->dev;
532 struct lp55xx_device_config *cfg = chip->cfg;
533
534 if (cfg->dev_attr_group)
535 sysfs_remove_group(&dev->kobj, cfg->dev_attr_group);
536
537 sysfs_remove_group(&dev->kobj, &lp55xx_engine_attr_group);
538}
539EXPORT_SYMBOL_GPL(lp55xx_unregister_sysfs);
540
541struct lp55xx_platform_data *lp55xx_of_populate_pdata(struct device *dev,
542 struct device_node *np)
543{
544 struct device_node *child;
545 struct lp55xx_platform_data *pdata;
546 struct lp55xx_led_config *cfg;
547 int num_channels;
548 int i = 0;
549
550 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
551 if (!pdata)
552 return ERR_PTR(-ENOMEM);
553
554 num_channels = of_get_child_count(np);
555 if (num_channels == 0) {
556 dev_err(dev, "no LED channels\n");
557 return ERR_PTR(-EINVAL);
558 }
559
560 cfg = devm_kcalloc(dev, num_channels, sizeof(*cfg), GFP_KERNEL);
561 if (!cfg)
562 return ERR_PTR(-ENOMEM);
563
564 pdata->led_config = &cfg[0];
565 pdata->num_channels = num_channels;
566
567 for_each_child_of_node(np, child) {
568 cfg[i].chan_nr = i;
569
570 of_property_read_string(child, "chan-name", &cfg[i].name);
571 of_property_read_u8(child, "led-cur", &cfg[i].led_current);
572 of_property_read_u8(child, "max-cur", &cfg[i].max_current);
573 cfg[i].default_trigger =
574 of_get_property(child, "linux,default-trigger", NULL);
575
576 i++;
577 }
578
579 of_property_read_string(np, "label", &pdata->label);
580 of_property_read_u8(np, "clock-mode", &pdata->clock_mode);
581
582 pdata->enable_gpio = of_get_named_gpio(np, "enable-gpio", 0);
583
584 /* LP8501 specific */
585 of_property_read_u8(np, "pwr-sel", (u8 *)&pdata->pwr_sel);
586
587 return pdata;
588}
589EXPORT_SYMBOL_GPL(lp55xx_of_populate_pdata);
590
591MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
592MODULE_DESCRIPTION("LP55xx Common Driver");
593MODULE_LICENSE("GPL");