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
lp5521_wait_opmode_done(void)99 static inline void lp5521_wait_opmode_done(void)
100 {
101 /* operation mode change needs to be longer than 153 us */
102 usleep_range(200, 300);
103 }
104
lp5521_wait_enable_done(void)105 static inline void lp5521_wait_enable_done(void)
106 {
107 /* it takes more 488 us to update ENABLE register */
108 usleep_range(500, 600);
109 }
110
lp5521_set_led_current(struct lp55xx_led * led,u8 led_current)111 static void lp5521_set_led_current(struct lp55xx_led *led, u8 led_current)
112 {
113 led->led_current = led_current;
114 lp55xx_write(led->chip, LP5521_REG_LED_CURRENT_BASE + led->chan_nr,
115 led_current);
116 }
117
lp5521_load_engine(struct lp55xx_chip * chip)118 static 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[idx], val[idx]);
134
135 lp5521_wait_opmode_done();
136 }
137
lp5521_stop_all_engines(struct lp55xx_chip * chip)138 static void lp5521_stop_all_engines(struct lp55xx_chip *chip)
139 {
140 lp55xx_write(chip, LP5521_REG_OP_MODE, 0);
141 lp5521_wait_opmode_done();
142 }
143
lp5521_stop_engine(struct lp55xx_chip * chip)144 static 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[idx], 0);
154
155 lp5521_wait_opmode_done();
156 }
157
lp5521_run_engine(struct lp55xx_chip * chip,bool start)158 static 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, &mode);
178 if (ret)
179 return;
180
181 ret = lp55xx_read(chip, LP5521_REG_ENABLE, &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, mode);
202 lp5521_wait_opmode_done();
203
204 lp55xx_update_bits(chip, LP5521_REG_ENABLE, LP5521_EXEC_M, exec);
205 lp5521_wait_enable_done();
206 }
207
lp5521_update_program_memory(struct lp55xx_chip * chip,const u8 * data,size_t size)208 static 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, addr[idx] + i, pattern[i]);
246 if (ret)
247 return -EINVAL;
248 }
249
250 return size;
251
252 err:
253 dev_err(&chip->cl->dev, "wrong pattern format\n");
254 return -EINVAL;
255 }
256
lp5521_firmware_loaded(struct lp55xx_chip * chip)257 static 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, fw->data, fw->size);
275 }
276
lp5521_post_init_device(struct lp55xx_chip * chip)277 static 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);
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(10000, 20000);
301
302 /* Set all PWMs to direct control mode */
303 ret = lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
304
305 /* Update configuration for the clock setting */
306 val = LP5521_DEFAULT_CFG;
307 if (!lp55xx_is_extclk_used(chip))
308 val |= LP5521_CLK_INT;
309
310 val |= (chip->pdata->charge_pump_mode << LP5521_CP_MODE_SHIFT) & LP5521_CP_MODE_MASK;
311
312 ret = lp55xx_write(chip, LP5521_REG_CONFIG, val);
313 if (ret)
314 return ret;
315
316 /* Initialize all channels PWM to zero -> leds off */
317 lp55xx_write(chip, LP5521_REG_R_PWM, 0);
318 lp55xx_write(chip, LP5521_REG_G_PWM, 0);
319 lp55xx_write(chip, LP5521_REG_B_PWM, 0);
320
321 /* Set engines are set to run state when OP_MODE enables engines */
322 ret = lp55xx_write(chip, LP5521_REG_ENABLE, LP5521_ENABLE_RUN_PROGRAM);
323 if (ret)
324 return ret;
325
326 lp5521_wait_enable_done();
327
328 return 0;
329 }
330
lp5521_run_selftest(struct lp55xx_chip * chip,char * buf)331 static int lp5521_run_selftest(struct lp55xx_chip *chip, char *buf)
332 {
333 struct lp55xx_platform_data *pdata = chip->pdata;
334 int ret;
335 u8 status;
336
337 ret = lp55xx_read(chip, LP5521_REG_STATUS, &status);
338 if (ret < 0)
339 return ret;
340
341 if (pdata->clock_mode != LP55XX_CLOCK_EXT)
342 return 0;
343
344 /* Check that ext clock is really in use if requested */
345 if ((status & LP5521_EXT_CLK_USED) == 0)
346 return -EIO;
347
348 return 0;
349 }
350
lp5521_multicolor_brightness(struct lp55xx_led * led)351 static int lp5521_multicolor_brightness(struct lp55xx_led *led)
352 {
353 struct lp55xx_chip *chip = led->chip;
354 int ret;
355 int i;
356
357 mutex_lock(&chip->lock);
358 for (i = 0; i < led->mc_cdev.num_colors; i++) {
359 ret = lp55xx_write(chip,
360 LP5521_REG_LED_PWM_BASE +
361 led->mc_cdev.subled_info[i].channel,
362 led->mc_cdev.subled_info[i].brightness);
363 if (ret)
364 break;
365 }
366 mutex_unlock(&chip->lock);
367 return ret;
368 }
369
lp5521_led_brightness(struct lp55xx_led * led)370 static int lp5521_led_brightness(struct lp55xx_led *led)
371 {
372 struct lp55xx_chip *chip = led->chip;
373 int ret;
374
375 mutex_lock(&chip->lock);
376 ret = lp55xx_write(chip, LP5521_REG_LED_PWM_BASE + led->chan_nr,
377 led->brightness);
378 mutex_unlock(&chip->lock);
379
380 return ret;
381 }
382
show_engine_mode(struct device * dev,struct device_attribute * attr,char * buf,int nr)383 static ssize_t show_engine_mode(struct device *dev,
384 struct device_attribute *attr,
385 char *buf, int nr)
386 {
387 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
388 struct lp55xx_chip *chip = led->chip;
389 enum lp55xx_engine_mode mode = chip->engines[nr - 1].mode;
390
391 switch (mode) {
392 case LP55XX_ENGINE_RUN:
393 return sprintf(buf, "run\n");
394 case LP55XX_ENGINE_LOAD:
395 return sprintf(buf, "load\n");
396 case LP55XX_ENGINE_DISABLED:
397 default:
398 return sprintf(buf, "disabled\n");
399 }
400 }
401 show_mode(1)
402 show_mode(2)
403 show_mode(3)
404
store_engine_mode(struct device * dev,struct device_attribute * attr,const char * buf,size_t len,int nr)405 static ssize_t store_engine_mode(struct device *dev,
406 struct device_attribute *attr,
407 const char *buf, size_t len, int nr)
408 {
409 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
410 struct lp55xx_chip *chip = led->chip;
411 struct lp55xx_engine *engine = &chip->engines[nr - 1];
412
413 mutex_lock(&chip->lock);
414
415 chip->engine_idx = nr;
416
417 if (!strncmp(buf, "run", 3)) {
418 lp5521_run_engine(chip, true);
419 engine->mode = LP55XX_ENGINE_RUN;
420 } else if (!strncmp(buf, "load", 4)) {
421 lp5521_stop_engine(chip);
422 lp5521_load_engine(chip);
423 engine->mode = LP55XX_ENGINE_LOAD;
424 } else if (!strncmp(buf, "disabled", 8)) {
425 lp5521_stop_engine(chip);
426 engine->mode = LP55XX_ENGINE_DISABLED;
427 }
428
429 mutex_unlock(&chip->lock);
430
431 return len;
432 }
433 store_mode(1)
434 store_mode(2)
435 store_mode(3)
436
store_engine_load(struct device * dev,struct device_attribute * attr,const char * buf,size_t len,int nr)437 static ssize_t store_engine_load(struct device *dev,
438 struct device_attribute *attr,
439 const char *buf, size_t len, int nr)
440 {
441 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
442 struct lp55xx_chip *chip = led->chip;
443 int ret;
444
445 mutex_lock(&chip->lock);
446
447 chip->engine_idx = nr;
448 lp5521_load_engine(chip);
449 ret = lp5521_update_program_memory(chip, buf, len);
450
451 mutex_unlock(&chip->lock);
452
453 return ret;
454 }
455 store_load(1)
456 store_load(2)
457 store_load(3)
458
lp5521_selftest(struct device * dev,struct device_attribute * attr,char * buf)459 static ssize_t lp5521_selftest(struct device *dev,
460 struct device_attribute *attr,
461 char *buf)
462 {
463 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
464 struct lp55xx_chip *chip = led->chip;
465 int ret;
466
467 mutex_lock(&chip->lock);
468 ret = lp5521_run_selftest(chip, buf);
469 mutex_unlock(&chip->lock);
470
471 return sysfs_emit(buf, "%s\n", ret ? "FAIL" : "OK");
472 }
473
474 /* device attributes */
475 static LP55XX_DEV_ATTR_RW(engine1_mode, show_engine1_mode, store_engine1_mode);
476 static LP55XX_DEV_ATTR_RW(engine2_mode, show_engine2_mode, store_engine2_mode);
477 static LP55XX_DEV_ATTR_RW(engine3_mode, show_engine3_mode, store_engine3_mode);
478 static LP55XX_DEV_ATTR_WO(engine1_load, store_engine1_load);
479 static LP55XX_DEV_ATTR_WO(engine2_load, store_engine2_load);
480 static LP55XX_DEV_ATTR_WO(engine3_load, store_engine3_load);
481 static LP55XX_DEV_ATTR_RO(selftest, lp5521_selftest);
482
483 static struct attribute *lp5521_attributes[] = {
484 &dev_attr_engine1_mode.attr,
485 &dev_attr_engine2_mode.attr,
486 &dev_attr_engine3_mode.attr,
487 &dev_attr_engine1_load.attr,
488 &dev_attr_engine2_load.attr,
489 &dev_attr_engine3_load.attr,
490 &dev_attr_selftest.attr,
491 NULL
492 };
493
494 static const struct attribute_group lp5521_group = {
495 .attrs = lp5521_attributes,
496 };
497
498 /* Chip specific configurations */
499 static struct lp55xx_device_config lp5521_cfg = {
500 .reset = {
501 .addr = LP5521_REG_RESET,
502 .val = LP5521_RESET,
503 },
504 .enable = {
505 .addr = LP5521_REG_ENABLE,
506 .val = LP5521_ENABLE_DEFAULT,
507 },
508 .max_channel = LP5521_MAX_LEDS,
509 .post_init_device = lp5521_post_init_device,
510 .brightness_fn = lp5521_led_brightness,
511 .multicolor_brightness_fn = lp5521_multicolor_brightness,
512 .set_led_current = lp5521_set_led_current,
513 .firmware_cb = lp5521_firmware_loaded,
514 .run_engine = lp5521_run_engine,
515 .dev_attr_group = &lp5521_group,
516 };
517
lp5521_probe(struct i2c_client * client)518 static int lp5521_probe(struct i2c_client *client)
519 {
520 const struct i2c_device_id *id = i2c_client_get_device_id(client);
521 int ret;
522 struct lp55xx_chip *chip;
523 struct lp55xx_led *led;
524 struct lp55xx_platform_data *pdata = dev_get_platdata(&client->dev);
525 struct device_node *np = dev_of_node(&client->dev);
526
527 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
528 if (!chip)
529 return -ENOMEM;
530
531 chip->cfg = &lp5521_cfg;
532
533 if (!pdata) {
534 if (np) {
535 pdata = lp55xx_of_populate_pdata(&client->dev, np,
536 chip);
537 if (IS_ERR(pdata))
538 return PTR_ERR(pdata);
539 } else {
540 dev_err(&client->dev, "no platform data\n");
541 return -EINVAL;
542 }
543 }
544
545 led = devm_kcalloc(&client->dev,
546 pdata->num_channels, sizeof(*led), GFP_KERNEL);
547 if (!led)
548 return -ENOMEM;
549
550 chip->cl = client;
551 chip->pdata = pdata;
552
553 mutex_init(&chip->lock);
554
555 i2c_set_clientdata(client, led);
556
557 ret = lp55xx_init_device(chip);
558 if (ret)
559 goto err_init;
560
561 dev_info(&client->dev, "%s programmable led chip found\n", id->name);
562
563 ret = lp55xx_register_leds(led, chip);
564 if (ret)
565 goto err_out;
566
567 ret = lp55xx_register_sysfs(chip);
568 if (ret) {
569 dev_err(&client->dev, "registering sysfs failed\n");
570 goto err_out;
571 }
572
573 return 0;
574
575 err_out:
576 lp55xx_deinit_device(chip);
577 err_init:
578 return ret;
579 }
580
lp5521_remove(struct i2c_client * client)581 static void lp5521_remove(struct i2c_client *client)
582 {
583 struct lp55xx_led *led = i2c_get_clientdata(client);
584 struct lp55xx_chip *chip = led->chip;
585
586 lp5521_stop_all_engines(chip);
587 lp55xx_unregister_sysfs(chip);
588 lp55xx_deinit_device(chip);
589 }
590
591 static const struct i2c_device_id lp5521_id[] = {
592 { "lp5521", 0 }, /* Three channel chip */
593 { }
594 };
595 MODULE_DEVICE_TABLE(i2c, lp5521_id);
596
597 static const struct of_device_id of_lp5521_leds_match[] = {
598 { .compatible = "national,lp5521", },
599 {},
600 };
601
602 MODULE_DEVICE_TABLE(of, of_lp5521_leds_match);
603
604 static struct i2c_driver lp5521_driver = {
605 .driver = {
606 .name = "lp5521",
607 .of_match_table = of_lp5521_leds_match,
608 },
609 .probe = lp5521_probe,
610 .remove = lp5521_remove,
611 .id_table = lp5521_id,
612 };
613
614 module_i2c_driver(lp5521_driver);
615
616 MODULE_AUTHOR("Mathias Nyman, Yuri Zaporozhets, Samu Onkalo");
617 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
618 MODULE_DESCRIPTION("LP5521 LED engine");
619 MODULE_LICENSE("GPL v2");
620