1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * LP5521 LED chip driver.
4 *
5 * Copyright (C) 2010 Nokia Corporation
6 * Copyright (C) 2012 Texas Instruments
7 *
8 * Contact: Samu Onkalo <samu.p.onkalo@nokia.com>
9 * Milo(Woogyom) Kim <milo.kim@ti.com>
10 */
11
12#include <linux/delay.h>
13#include <linux/firmware.h>
14#include <linux/i2c.h>
15#include <linux/leds.h>
16#include <linux/module.h>
17#include <linux/mutex.h>
18#include <linux/platform_data/leds-lp55xx.h>
19#include <linux/slab.h>
20#include <linux/of.h>
21
22#include "leds-lp55xx-common.h"
23
24#define LP5521_PROGRAM_LENGTH 32
25#define LP5521_MAX_LEDS 3
26#define LP5521_CMD_DIRECT 0x3F
27
28/* Registers */
29#define LP5521_REG_ENABLE 0x00
30#define LP5521_REG_OP_MODE 0x01
31#define LP5521_REG_R_PWM 0x02
32#define LP5521_REG_G_PWM 0x03
33#define LP5521_REG_B_PWM 0x04
34#define LP5521_REG_R_CURRENT 0x05
35#define LP5521_REG_G_CURRENT 0x06
36#define LP5521_REG_B_CURRENT 0x07
37#define LP5521_REG_CONFIG 0x08
38#define LP5521_REG_STATUS 0x0C
39#define LP5521_REG_RESET 0x0D
40#define LP5521_REG_R_PROG_MEM 0x10
41#define LP5521_REG_G_PROG_MEM 0x30
42#define LP5521_REG_B_PROG_MEM 0x50
43
44/* Base register to set LED current */
45#define LP5521_REG_LED_CURRENT_BASE LP5521_REG_R_CURRENT
46/* Base register to set the brightness */
47#define LP5521_REG_LED_PWM_BASE LP5521_REG_R_PWM
48
49/* Bits in ENABLE register */
50#define LP5521_MASTER_ENABLE 0x40 /* Chip master enable */
51#define LP5521_LOGARITHMIC_PWM 0x80 /* Logarithmic PWM adjustment */
52#define LP5521_EXEC_RUN 0x2A
53#define LP5521_ENABLE_DEFAULT \
54 (LP5521_MASTER_ENABLE | LP5521_LOGARITHMIC_PWM)
55#define LP5521_ENABLE_RUN_PROGRAM \
56 (LP5521_ENABLE_DEFAULT | LP5521_EXEC_RUN)
57
58/* CONFIG register */
59#define LP5521_PWM_HF 0x40 /* PWM: 0 = 256Hz, 1 = 558Hz */
60#define LP5521_PWRSAVE_EN 0x20 /* 1 = Power save mode */
61#define LP5521_CP_MODE_MASK 0x18 /* Charge pump mode */
62#define LP5521_CP_MODE_SHIFT 3
63#define LP5521_R_TO_BATT 0x04 /* R out: 0 = CP, 1 = Vbat */
64#define LP5521_CLK_INT 0x01 /* Internal clock */
65#define LP5521_DEFAULT_CFG (LP5521_PWM_HF | LP5521_PWRSAVE_EN)
66
67/* Status */
68#define LP5521_EXT_CLK_USED 0x08
69
70/* default R channel current register value */
71#define LP5521_REG_R_CURR_DEFAULT 0xAF
72
73/* Reset register value */
74#define LP5521_RESET 0xFF
75
76/* Program Memory Operations */
77#define LP5521_MODE_R_M 0x30 /* Operation Mode Register */
78#define LP5521_MODE_G_M 0x0C
79#define LP5521_MODE_B_M 0x03
80#define LP5521_LOAD_R 0x10
81#define LP5521_LOAD_G 0x04
82#define LP5521_LOAD_B 0x01
83
84#define LP5521_R_IS_LOADING(mode) \
85 ((mode & LP5521_MODE_R_M) == LP5521_LOAD_R)
86#define LP5521_G_IS_LOADING(mode) \
87 ((mode & LP5521_MODE_G_M) == LP5521_LOAD_G)
88#define LP5521_B_IS_LOADING(mode) \
89 ((mode & LP5521_MODE_B_M) == LP5521_LOAD_B)
90
91#define LP5521_EXEC_R_M 0x30 /* Enable Register */
92#define LP5521_EXEC_G_M 0x0C
93#define LP5521_EXEC_B_M 0x03
94#define LP5521_EXEC_M 0x3F
95#define LP5521_RUN_R 0x20
96#define LP5521_RUN_G 0x08
97#define LP5521_RUN_B 0x02
98
99static inline void lp5521_wait_opmode_done(void)
100{
101 /* operation mode change needs to be longer than 153 us */
102 usleep_range(min: 200, max: 300);
103}
104
105static inline void lp5521_wait_enable_done(void)
106{
107 /* it takes more 488 us to update ENABLE register */
108 usleep_range(min: 500, max: 600);
109}
110
111static void lp5521_set_led_current(struct lp55xx_led *led, u8 led_current)
112{
113 led->led_current = led_current;
114 lp55xx_write(chip: led->chip, LP5521_REG_LED_CURRENT_BASE + led->chan_nr,
115 val: led_current);
116}
117
118static void lp5521_load_engine(struct lp55xx_chip *chip)
119{
120 enum lp55xx_engine_index idx = chip->engine_idx;
121 static const u8 mask[] = {
122 [LP55XX_ENGINE_1] = LP5521_MODE_R_M,
123 [LP55XX_ENGINE_2] = LP5521_MODE_G_M,
124 [LP55XX_ENGINE_3] = LP5521_MODE_B_M,
125 };
126
127 static const u8 val[] = {
128 [LP55XX_ENGINE_1] = LP5521_LOAD_R,
129 [LP55XX_ENGINE_2] = LP5521_LOAD_G,
130 [LP55XX_ENGINE_3] = LP5521_LOAD_B,
131 };
132
133 lp55xx_update_bits(chip, LP5521_REG_OP_MODE, mask: mask[idx], val: val[idx]);
134
135 lp5521_wait_opmode_done();
136}
137
138static void lp5521_stop_all_engines(struct lp55xx_chip *chip)
139{
140 lp55xx_write(chip, LP5521_REG_OP_MODE, val: 0);
141 lp5521_wait_opmode_done();
142}
143
144static void lp5521_stop_engine(struct lp55xx_chip *chip)
145{
146 enum lp55xx_engine_index idx = chip->engine_idx;
147 static const u8 mask[] = {
148 [LP55XX_ENGINE_1] = LP5521_MODE_R_M,
149 [LP55XX_ENGINE_2] = LP5521_MODE_G_M,
150 [LP55XX_ENGINE_3] = LP5521_MODE_B_M,
151 };
152
153 lp55xx_update_bits(chip, LP5521_REG_OP_MODE, mask: mask[idx], val: 0);
154
155 lp5521_wait_opmode_done();
156}
157
158static void lp5521_run_engine(struct lp55xx_chip *chip, bool start)
159{
160 int ret;
161 u8 mode;
162 u8 exec;
163
164 /* stop engine */
165 if (!start) {
166 lp5521_stop_engine(chip);
167 lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
168 lp5521_wait_opmode_done();
169 return;
170 }
171
172 /*
173 * To run the engine,
174 * operation mode and enable register should updated at the same time
175 */
176
177 ret = lp55xx_read(chip, LP5521_REG_OP_MODE, val: &mode);
178 if (ret)
179 return;
180
181 ret = lp55xx_read(chip, LP5521_REG_ENABLE, val: &exec);
182 if (ret)
183 return;
184
185 /* change operation mode to RUN only when each engine is loading */
186 if (LP5521_R_IS_LOADING(mode)) {
187 mode = (mode & ~LP5521_MODE_R_M) | LP5521_RUN_R;
188 exec = (exec & ~LP5521_EXEC_R_M) | LP5521_RUN_R;
189 }
190
191 if (LP5521_G_IS_LOADING(mode)) {
192 mode = (mode & ~LP5521_MODE_G_M) | LP5521_RUN_G;
193 exec = (exec & ~LP5521_EXEC_G_M) | LP5521_RUN_G;
194 }
195
196 if (LP5521_B_IS_LOADING(mode)) {
197 mode = (mode & ~LP5521_MODE_B_M) | LP5521_RUN_B;
198 exec = (exec & ~LP5521_EXEC_B_M) | LP5521_RUN_B;
199 }
200
201 lp55xx_write(chip, LP5521_REG_OP_MODE, val: mode);
202 lp5521_wait_opmode_done();
203
204 lp55xx_update_bits(chip, LP5521_REG_ENABLE, LP5521_EXEC_M, val: exec);
205 lp5521_wait_enable_done();
206}
207
208static int lp5521_update_program_memory(struct lp55xx_chip *chip,
209 const u8 *data, size_t size)
210{
211 enum lp55xx_engine_index idx = chip->engine_idx;
212 u8 pattern[LP5521_PROGRAM_LENGTH] = {0};
213 static const u8 addr[] = {
214 [LP55XX_ENGINE_1] = LP5521_REG_R_PROG_MEM,
215 [LP55XX_ENGINE_2] = LP5521_REG_G_PROG_MEM,
216 [LP55XX_ENGINE_3] = LP5521_REG_B_PROG_MEM,
217 };
218 unsigned cmd;
219 char c[3];
220 int nrchars;
221 int ret;
222 int offset = 0;
223 int i = 0;
224
225 while ((offset < size - 1) && (i < LP5521_PROGRAM_LENGTH)) {
226 /* separate sscanfs because length is working only for %s */
227 ret = sscanf(data + offset, "%2s%n ", c, &nrchars);
228 if (ret != 1)
229 goto err;
230
231 ret = sscanf(c, "%2x", &cmd);
232 if (ret != 1)
233 goto err;
234
235 pattern[i] = (u8)cmd;
236 offset += nrchars;
237 i++;
238 }
239
240 /* Each instruction is 16bit long. Check that length is even */
241 if (i % 2)
242 goto err;
243
244 for (i = 0; i < LP5521_PROGRAM_LENGTH; i++) {
245 ret = lp55xx_write(chip, reg: addr[idx] + i, val: pattern[i]);
246 if (ret)
247 return -EINVAL;
248 }
249
250 return size;
251
252err:
253 dev_err(&chip->cl->dev, "wrong pattern format\n");
254 return -EINVAL;
255}
256
257static void lp5521_firmware_loaded(struct lp55xx_chip *chip)
258{
259 const struct firmware *fw = chip->fw;
260
261 if (fw->size > LP5521_PROGRAM_LENGTH) {
262 dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
263 fw->size);
264 return;
265 }
266
267 /*
268 * Program memory sequence
269 * 1) set engine mode to "LOAD"
270 * 2) write firmware data into program memory
271 */
272
273 lp5521_load_engine(chip);
274 lp5521_update_program_memory(chip, data: fw->data, size: fw->size);
275}
276
277static int lp5521_post_init_device(struct lp55xx_chip *chip)
278{
279 int ret;
280 u8 val;
281
282 /*
283 * Make sure that the chip is reset by reading back the r channel
284 * current reg. This is dummy read is required on some platforms -
285 * otherwise further access to the R G B channels in the
286 * LP5521_REG_ENABLE register will not have any effect - strange!
287 */
288 ret = lp55xx_read(chip, LP5521_REG_R_CURRENT, val: &val);
289 if (ret) {
290 dev_err(&chip->cl->dev, "error in resetting chip\n");
291 return ret;
292 }
293 if (val != LP5521_REG_R_CURR_DEFAULT) {
294 dev_err(&chip->cl->dev,
295 "unexpected data in register (expected 0x%x got 0x%x)\n",
296 LP5521_REG_R_CURR_DEFAULT, val);
297 ret = -EINVAL;
298 return ret;
299 }
300 usleep_range(min: 10000, max: 20000);
301
302 /* Set all PWMs to direct control mode */
303 ret = lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
304 if (ret)
305 return ret;
306
307 /* Update configuration for the clock setting */
308 val = LP5521_DEFAULT_CFG;
309 if (!lp55xx_is_extclk_used(chip))
310 val |= LP5521_CLK_INT;
311
312 val |= (chip->pdata->charge_pump_mode << LP5521_CP_MODE_SHIFT) & LP5521_CP_MODE_MASK;
313
314 ret = lp55xx_write(chip, LP5521_REG_CONFIG, val);
315 if (ret)
316 return ret;
317
318 /* Initialize all channels PWM to zero -> leds off */
319 lp55xx_write(chip, LP5521_REG_R_PWM, val: 0);
320 lp55xx_write(chip, LP5521_REG_G_PWM, val: 0);
321 lp55xx_write(chip, LP5521_REG_B_PWM, val: 0);
322
323 /* Set engines are set to run state when OP_MODE enables engines */
324 ret = lp55xx_write(chip, LP5521_REG_ENABLE, LP5521_ENABLE_RUN_PROGRAM);
325 if (ret)
326 return ret;
327
328 lp5521_wait_enable_done();
329
330 return 0;
331}
332
333static int lp5521_run_selftest(struct lp55xx_chip *chip, char *buf)
334{
335 struct lp55xx_platform_data *pdata = chip->pdata;
336 int ret;
337 u8 status;
338
339 ret = lp55xx_read(chip, LP5521_REG_STATUS, val: &status);
340 if (ret < 0)
341 return ret;
342
343 if (pdata->clock_mode != LP55XX_CLOCK_EXT)
344 return 0;
345
346 /* Check that ext clock is really in use if requested */
347 if ((status & LP5521_EXT_CLK_USED) == 0)
348 return -EIO;
349
350 return 0;
351}
352
353static int lp5521_multicolor_brightness(struct lp55xx_led *led)
354{
355 struct lp55xx_chip *chip = led->chip;
356 int ret;
357 int i;
358
359 mutex_lock(&chip->lock);
360 for (i = 0; i < led->mc_cdev.num_colors; i++) {
361 ret = lp55xx_write(chip,
362 LP5521_REG_LED_PWM_BASE +
363 led->mc_cdev.subled_info[i].channel,
364 val: led->mc_cdev.subled_info[i].brightness);
365 if (ret)
366 break;
367 }
368 mutex_unlock(lock: &chip->lock);
369 return ret;
370}
371
372static int lp5521_led_brightness(struct lp55xx_led *led)
373{
374 struct lp55xx_chip *chip = led->chip;
375 int ret;
376
377 mutex_lock(&chip->lock);
378 ret = lp55xx_write(chip, LP5521_REG_LED_PWM_BASE + led->chan_nr,
379 val: led->brightness);
380 mutex_unlock(lock: &chip->lock);
381
382 return ret;
383}
384
385static ssize_t show_engine_mode(struct device *dev,
386 struct device_attribute *attr,
387 char *buf, int nr)
388{
389 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
390 struct lp55xx_chip *chip = led->chip;
391 enum lp55xx_engine_mode mode = chip->engines[nr - 1].mode;
392
393 switch (mode) {
394 case LP55XX_ENGINE_RUN:
395 return sprintf(buf, fmt: "run\n");
396 case LP55XX_ENGINE_LOAD:
397 return sprintf(buf, fmt: "load\n");
398 case LP55XX_ENGINE_DISABLED:
399 default:
400 return sprintf(buf, fmt: "disabled\n");
401 }
402}
403show_mode(1)
404show_mode(2)
405show_mode(3)
406
407static ssize_t store_engine_mode(struct device *dev,
408 struct device_attribute *attr,
409 const char *buf, size_t len, int nr)
410{
411 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
412 struct lp55xx_chip *chip = led->chip;
413 struct lp55xx_engine *engine = &chip->engines[nr - 1];
414
415 mutex_lock(&chip->lock);
416
417 chip->engine_idx = nr;
418
419 if (!strncmp(buf, "run", 3)) {
420 lp5521_run_engine(chip, start: true);
421 engine->mode = LP55XX_ENGINE_RUN;
422 } else if (!strncmp(buf, "load", 4)) {
423 lp5521_stop_engine(chip);
424 lp5521_load_engine(chip);
425 engine->mode = LP55XX_ENGINE_LOAD;
426 } else if (!strncmp(buf, "disabled", 8)) {
427 lp5521_stop_engine(chip);
428 engine->mode = LP55XX_ENGINE_DISABLED;
429 }
430
431 mutex_unlock(lock: &chip->lock);
432
433 return len;
434}
435store_mode(1)
436store_mode(2)
437store_mode(3)
438
439static ssize_t store_engine_load(struct device *dev,
440 struct device_attribute *attr,
441 const char *buf, size_t len, int nr)
442{
443 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
444 struct lp55xx_chip *chip = led->chip;
445 int ret;
446
447 mutex_lock(&chip->lock);
448
449 chip->engine_idx = nr;
450 lp5521_load_engine(chip);
451 ret = lp5521_update_program_memory(chip, data: buf, size: len);
452
453 mutex_unlock(lock: &chip->lock);
454
455 return ret;
456}
457store_load(1)
458store_load(2)
459store_load(3)
460
461static ssize_t lp5521_selftest(struct device *dev,
462 struct device_attribute *attr,
463 char *buf)
464{
465 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
466 struct lp55xx_chip *chip = led->chip;
467 int ret;
468
469 mutex_lock(&chip->lock);
470 ret = lp5521_run_selftest(chip, buf);
471 mutex_unlock(lock: &chip->lock);
472
473 return sysfs_emit(buf, fmt: "%s\n", ret ? "FAIL" : "OK");
474}
475
476/* device attributes */
477static LP55XX_DEV_ATTR_RW(engine1_mode, show_engine1_mode, store_engine1_mode);
478static LP55XX_DEV_ATTR_RW(engine2_mode, show_engine2_mode, store_engine2_mode);
479static LP55XX_DEV_ATTR_RW(engine3_mode, show_engine3_mode, store_engine3_mode);
480static LP55XX_DEV_ATTR_WO(engine1_load, store_engine1_load);
481static LP55XX_DEV_ATTR_WO(engine2_load, store_engine2_load);
482static LP55XX_DEV_ATTR_WO(engine3_load, store_engine3_load);
483static LP55XX_DEV_ATTR_RO(selftest, lp5521_selftest);
484
485static struct attribute *lp5521_attributes[] = {
486 &dev_attr_engine1_mode.attr,
487 &dev_attr_engine2_mode.attr,
488 &dev_attr_engine3_mode.attr,
489 &dev_attr_engine1_load.attr,
490 &dev_attr_engine2_load.attr,
491 &dev_attr_engine3_load.attr,
492 &dev_attr_selftest.attr,
493 NULL
494};
495
496static const struct attribute_group lp5521_group = {
497 .attrs = lp5521_attributes,
498};
499
500/* Chip specific configurations */
501static struct lp55xx_device_config lp5521_cfg = {
502 .reset = {
503 .addr = LP5521_REG_RESET,
504 .val = LP5521_RESET,
505 },
506 .enable = {
507 .addr = LP5521_REG_ENABLE,
508 .val = LP5521_ENABLE_DEFAULT,
509 },
510 .max_channel = LP5521_MAX_LEDS,
511 .post_init_device = lp5521_post_init_device,
512 .brightness_fn = lp5521_led_brightness,
513 .multicolor_brightness_fn = lp5521_multicolor_brightness,
514 .set_led_current = lp5521_set_led_current,
515 .firmware_cb = lp5521_firmware_loaded,
516 .run_engine = lp5521_run_engine,
517 .dev_attr_group = &lp5521_group,
518};
519
520static int lp5521_probe(struct i2c_client *client)
521{
522 const struct i2c_device_id *id = i2c_client_get_device_id(client);
523 int ret;
524 struct lp55xx_chip *chip;
525 struct lp55xx_led *led;
526 struct lp55xx_platform_data *pdata = dev_get_platdata(dev: &client->dev);
527 struct device_node *np = dev_of_node(dev: &client->dev);
528
529 chip = devm_kzalloc(dev: &client->dev, size: sizeof(*chip), GFP_KERNEL);
530 if (!chip)
531 return -ENOMEM;
532
533 chip->cfg = &lp5521_cfg;
534
535 if (!pdata) {
536 if (np) {
537 pdata = lp55xx_of_populate_pdata(dev: &client->dev, np,
538 chip);
539 if (IS_ERR(ptr: pdata))
540 return PTR_ERR(ptr: pdata);
541 } else {
542 dev_err(&client->dev, "no platform data\n");
543 return -EINVAL;
544 }
545 }
546
547 led = devm_kcalloc(dev: &client->dev,
548 n: pdata->num_channels, size: sizeof(*led), GFP_KERNEL);
549 if (!led)
550 return -ENOMEM;
551
552 chip->cl = client;
553 chip->pdata = pdata;
554
555 mutex_init(&chip->lock);
556
557 i2c_set_clientdata(client, data: led);
558
559 ret = lp55xx_init_device(chip);
560 if (ret)
561 goto err_init;
562
563 dev_info(&client->dev, "%s programmable led chip found\n", id->name);
564
565 ret = lp55xx_register_leds(led, chip);
566 if (ret)
567 goto err_out;
568
569 ret = lp55xx_register_sysfs(chip);
570 if (ret) {
571 dev_err(&client->dev, "registering sysfs failed\n");
572 goto err_out;
573 }
574
575 return 0;
576
577err_out:
578 lp55xx_deinit_device(chip);
579err_init:
580 return ret;
581}
582
583static void lp5521_remove(struct i2c_client *client)
584{
585 struct lp55xx_led *led = i2c_get_clientdata(client);
586 struct lp55xx_chip *chip = led->chip;
587
588 lp5521_stop_all_engines(chip);
589 lp55xx_unregister_sysfs(chip);
590 lp55xx_deinit_device(chip);
591}
592
593static const struct i2c_device_id lp5521_id[] = {
594 { "lp5521", 0 }, /* Three channel chip */
595 { }
596};
597MODULE_DEVICE_TABLE(i2c, lp5521_id);
598
599static const struct of_device_id of_lp5521_leds_match[] = {
600 { .compatible = "national,lp5521", },
601 {},
602};
603
604MODULE_DEVICE_TABLE(of, of_lp5521_leds_match);
605
606static struct i2c_driver lp5521_driver = {
607 .driver = {
608 .name = "lp5521",
609 .of_match_table = of_lp5521_leds_match,
610 },
611 .probe = lp5521_probe,
612 .remove = lp5521_remove,
613 .id_table = lp5521_id,
614};
615
616module_i2c_driver(lp5521_driver);
617
618MODULE_AUTHOR("Mathias Nyman, Yuri Zaporozhets, Samu Onkalo");
619MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
620MODULE_DESCRIPTION("LP5521 LED engine");
621MODULE_LICENSE("GPL v2");
622

source code of linux/drivers/leds/leds-lp5521.c