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_OFF 0 /* Charge pump (CP) off */
62 #define LP5521_CP_MODE_BYPASS 8 /* CP forced to bypass mode */
63 #define LP5521_CP_MODE_1X5 0x10 /* CP forced to 1.5x mode */
64 #define LP5521_CP_MODE_AUTO 0x18 /* Automatic mode selection */
65 #define LP5521_R_TO_BATT 0x04 /* R out: 0 = CP, 1 = Vbat */
66 #define LP5521_CLK_INT 0x01 /* Internal clock */
67 #define LP5521_DEFAULT_CFG \
68 (LP5521_PWM_HF | LP5521_PWRSAVE_EN | LP5521_CP_MODE_AUTO)
69
70 /* Status */
71 #define LP5521_EXT_CLK_USED 0x08
72
73 /* default R channel current register value */
74 #define LP5521_REG_R_CURR_DEFAULT 0xAF
75
76 /* Reset register value */
77 #define LP5521_RESET 0xFF
78
79 /* Program Memory Operations */
80 #define LP5521_MODE_R_M 0x30 /* Operation Mode Register */
81 #define LP5521_MODE_G_M 0x0C
82 #define LP5521_MODE_B_M 0x03
83 #define LP5521_LOAD_R 0x10
84 #define LP5521_LOAD_G 0x04
85 #define LP5521_LOAD_B 0x01
86
87 #define LP5521_R_IS_LOADING(mode) \
88 ((mode & LP5521_MODE_R_M) == LP5521_LOAD_R)
89 #define LP5521_G_IS_LOADING(mode) \
90 ((mode & LP5521_MODE_G_M) == LP5521_LOAD_G)
91 #define LP5521_B_IS_LOADING(mode) \
92 ((mode & LP5521_MODE_B_M) == LP5521_LOAD_B)
93
94 #define LP5521_EXEC_R_M 0x30 /* Enable Register */
95 #define LP5521_EXEC_G_M 0x0C
96 #define LP5521_EXEC_B_M 0x03
97 #define LP5521_EXEC_M 0x3F
98 #define LP5521_RUN_R 0x20
99 #define LP5521_RUN_G 0x08
100 #define LP5521_RUN_B 0x02
101
lp5521_wait_opmode_done(void)102 static inline void lp5521_wait_opmode_done(void)
103 {
104 /* operation mode change needs to be longer than 153 us */
105 usleep_range(200, 300);
106 }
107
lp5521_wait_enable_done(void)108 static inline void lp5521_wait_enable_done(void)
109 {
110 /* it takes more 488 us to update ENABLE register */
111 usleep_range(500, 600);
112 }
113
lp5521_set_led_current(struct lp55xx_led * led,u8 led_current)114 static void lp5521_set_led_current(struct lp55xx_led *led, u8 led_current)
115 {
116 led->led_current = led_current;
117 lp55xx_write(led->chip, LP5521_REG_LED_CURRENT_BASE + led->chan_nr,
118 led_current);
119 }
120
lp5521_load_engine(struct lp55xx_chip * chip)121 static void lp5521_load_engine(struct lp55xx_chip *chip)
122 {
123 enum lp55xx_engine_index idx = chip->engine_idx;
124 static const u8 mask[] = {
125 [LP55XX_ENGINE_1] = LP5521_MODE_R_M,
126 [LP55XX_ENGINE_2] = LP5521_MODE_G_M,
127 [LP55XX_ENGINE_3] = LP5521_MODE_B_M,
128 };
129
130 static const u8 val[] = {
131 [LP55XX_ENGINE_1] = LP5521_LOAD_R,
132 [LP55XX_ENGINE_2] = LP5521_LOAD_G,
133 [LP55XX_ENGINE_3] = LP5521_LOAD_B,
134 };
135
136 lp55xx_update_bits(chip, LP5521_REG_OP_MODE, mask[idx], val[idx]);
137
138 lp5521_wait_opmode_done();
139 }
140
lp5521_stop_all_engines(struct lp55xx_chip * chip)141 static void lp5521_stop_all_engines(struct lp55xx_chip *chip)
142 {
143 lp55xx_write(chip, LP5521_REG_OP_MODE, 0);
144 lp5521_wait_opmode_done();
145 }
146
lp5521_stop_engine(struct lp55xx_chip * chip)147 static void lp5521_stop_engine(struct lp55xx_chip *chip)
148 {
149 enum lp55xx_engine_index idx = chip->engine_idx;
150 static const u8 mask[] = {
151 [LP55XX_ENGINE_1] = LP5521_MODE_R_M,
152 [LP55XX_ENGINE_2] = LP5521_MODE_G_M,
153 [LP55XX_ENGINE_3] = LP5521_MODE_B_M,
154 };
155
156 lp55xx_update_bits(chip, LP5521_REG_OP_MODE, mask[idx], 0);
157
158 lp5521_wait_opmode_done();
159 }
160
lp5521_run_engine(struct lp55xx_chip * chip,bool start)161 static void lp5521_run_engine(struct lp55xx_chip *chip, bool start)
162 {
163 int ret;
164 u8 mode;
165 u8 exec;
166
167 /* stop engine */
168 if (!start) {
169 lp5521_stop_engine(chip);
170 lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
171 lp5521_wait_opmode_done();
172 return;
173 }
174
175 /*
176 * To run the engine,
177 * operation mode and enable register should updated at the same time
178 */
179
180 ret = lp55xx_read(chip, LP5521_REG_OP_MODE, &mode);
181 if (ret)
182 return;
183
184 ret = lp55xx_read(chip, LP5521_REG_ENABLE, &exec);
185 if (ret)
186 return;
187
188 /* change operation mode to RUN only when each engine is loading */
189 if (LP5521_R_IS_LOADING(mode)) {
190 mode = (mode & ~LP5521_MODE_R_M) | LP5521_RUN_R;
191 exec = (exec & ~LP5521_EXEC_R_M) | LP5521_RUN_R;
192 }
193
194 if (LP5521_G_IS_LOADING(mode)) {
195 mode = (mode & ~LP5521_MODE_G_M) | LP5521_RUN_G;
196 exec = (exec & ~LP5521_EXEC_G_M) | LP5521_RUN_G;
197 }
198
199 if (LP5521_B_IS_LOADING(mode)) {
200 mode = (mode & ~LP5521_MODE_B_M) | LP5521_RUN_B;
201 exec = (exec & ~LP5521_EXEC_B_M) | LP5521_RUN_B;
202 }
203
204 lp55xx_write(chip, LP5521_REG_OP_MODE, mode);
205 lp5521_wait_opmode_done();
206
207 lp55xx_update_bits(chip, LP5521_REG_ENABLE, LP5521_EXEC_M, exec);
208 lp5521_wait_enable_done();
209 }
210
lp5521_update_program_memory(struct lp55xx_chip * chip,const u8 * data,size_t size)211 static int lp5521_update_program_memory(struct lp55xx_chip *chip,
212 const u8 *data, size_t size)
213 {
214 enum lp55xx_engine_index idx = chip->engine_idx;
215 u8 pattern[LP5521_PROGRAM_LENGTH] = {0};
216 static const u8 addr[] = {
217 [LP55XX_ENGINE_1] = LP5521_REG_R_PROG_MEM,
218 [LP55XX_ENGINE_2] = LP5521_REG_G_PROG_MEM,
219 [LP55XX_ENGINE_3] = LP5521_REG_B_PROG_MEM,
220 };
221 unsigned cmd;
222 char c[3];
223 int nrchars;
224 int ret;
225 int offset = 0;
226 int i = 0;
227
228 while ((offset < size - 1) && (i < LP5521_PROGRAM_LENGTH)) {
229 /* separate sscanfs because length is working only for %s */
230 ret = sscanf(data + offset, "%2s%n ", c, &nrchars);
231 if (ret != 1)
232 goto err;
233
234 ret = sscanf(c, "%2x", &cmd);
235 if (ret != 1)
236 goto err;
237
238 pattern[i] = (u8)cmd;
239 offset += nrchars;
240 i++;
241 }
242
243 /* Each instruction is 16bit long. Check that length is even */
244 if (i % 2)
245 goto err;
246
247 for (i = 0; i < LP5521_PROGRAM_LENGTH; i++) {
248 ret = lp55xx_write(chip, addr[idx] + i, pattern[i]);
249 if (ret)
250 return -EINVAL;
251 }
252
253 return size;
254
255 err:
256 dev_err(&chip->cl->dev, "wrong pattern format\n");
257 return -EINVAL;
258 }
259
lp5521_firmware_loaded(struct lp55xx_chip * chip)260 static void lp5521_firmware_loaded(struct lp55xx_chip *chip)
261 {
262 const struct firmware *fw = chip->fw;
263
264 if (fw->size > LP5521_PROGRAM_LENGTH) {
265 dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
266 fw->size);
267 return;
268 }
269
270 /*
271 * Program memory sequence
272 * 1) set engine mode to "LOAD"
273 * 2) write firmware data into program memory
274 */
275
276 lp5521_load_engine(chip);
277 lp5521_update_program_memory(chip, fw->data, fw->size);
278 }
279
lp5521_post_init_device(struct lp55xx_chip * chip)280 static int lp5521_post_init_device(struct lp55xx_chip *chip)
281 {
282 int ret;
283 u8 val;
284
285 /*
286 * Make sure that the chip is reset by reading back the r channel
287 * current reg. This is dummy read is required on some platforms -
288 * otherwise further access to the R G B channels in the
289 * LP5521_REG_ENABLE register will not have any effect - strange!
290 */
291 ret = lp55xx_read(chip, LP5521_REG_R_CURRENT, &val);
292 if (ret) {
293 dev_err(&chip->cl->dev, "error in resetting chip\n");
294 return ret;
295 }
296 if (val != LP5521_REG_R_CURR_DEFAULT) {
297 dev_err(&chip->cl->dev,
298 "unexpected data in register (expected 0x%x got 0x%x)\n",
299 LP5521_REG_R_CURR_DEFAULT, val);
300 ret = -EINVAL;
301 return ret;
302 }
303 usleep_range(10000, 20000);
304
305 /* Set all PWMs to direct control mode */
306 ret = lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
307
308 /* Update configuration for the clock setting */
309 val = LP5521_DEFAULT_CFG;
310 if (!lp55xx_is_extclk_used(chip))
311 val |= LP5521_CLK_INT;
312
313 ret = lp55xx_write(chip, LP5521_REG_CONFIG, val);
314 if (ret)
315 return ret;
316
317 /* Initialize all channels PWM to zero -> leds off */
318 lp55xx_write(chip, LP5521_REG_R_PWM, 0);
319 lp55xx_write(chip, LP5521_REG_G_PWM, 0);
320 lp55xx_write(chip, LP5521_REG_B_PWM, 0);
321
322 /* Set engines are set to run state when OP_MODE enables engines */
323 ret = lp55xx_write(chip, LP5521_REG_ENABLE, LP5521_ENABLE_RUN_PROGRAM);
324 if (ret)
325 return ret;
326
327 lp5521_wait_enable_done();
328
329 return 0;
330 }
331
lp5521_run_selftest(struct lp55xx_chip * chip,char * buf)332 static int lp5521_run_selftest(struct lp55xx_chip *chip, char *buf)
333 {
334 struct lp55xx_platform_data *pdata = chip->pdata;
335 int ret;
336 u8 status;
337
338 ret = lp55xx_read(chip, LP5521_REG_STATUS, &status);
339 if (ret < 0)
340 return ret;
341
342 if (pdata->clock_mode != LP55XX_CLOCK_EXT)
343 return 0;
344
345 /* Check that ext clock is really in use if requested */
346 if ((status & LP5521_EXT_CLK_USED) == 0)
347 return -EIO;
348
349 return 0;
350 }
351
lp5521_led_brightness(struct lp55xx_led * led)352 static int lp5521_led_brightness(struct lp55xx_led *led)
353 {
354 struct lp55xx_chip *chip = led->chip;
355 int ret;
356
357 mutex_lock(&chip->lock);
358 ret = lp55xx_write(chip, LP5521_REG_LED_PWM_BASE + led->chan_nr,
359 led->brightness);
360 mutex_unlock(&chip->lock);
361
362 return ret;
363 }
364
show_engine_mode(struct device * dev,struct device_attribute * attr,char * buf,int nr)365 static ssize_t show_engine_mode(struct device *dev,
366 struct device_attribute *attr,
367 char *buf, int nr)
368 {
369 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
370 struct lp55xx_chip *chip = led->chip;
371 enum lp55xx_engine_mode mode = chip->engines[nr - 1].mode;
372
373 switch (mode) {
374 case LP55XX_ENGINE_RUN:
375 return sprintf(buf, "run\n");
376 case LP55XX_ENGINE_LOAD:
377 return sprintf(buf, "load\n");
378 case LP55XX_ENGINE_DISABLED:
379 default:
380 return sprintf(buf, "disabled\n");
381 }
382 }
383 show_mode(1)
384 show_mode(2)
385 show_mode(3)
386
store_engine_mode(struct device * dev,struct device_attribute * attr,const char * buf,size_t len,int nr)387 static ssize_t store_engine_mode(struct device *dev,
388 struct device_attribute *attr,
389 const char *buf, size_t len, int nr)
390 {
391 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
392 struct lp55xx_chip *chip = led->chip;
393 struct lp55xx_engine *engine = &chip->engines[nr - 1];
394
395 mutex_lock(&chip->lock);
396
397 chip->engine_idx = nr;
398
399 if (!strncmp(buf, "run", 3)) {
400 lp5521_run_engine(chip, true);
401 engine->mode = LP55XX_ENGINE_RUN;
402 } else if (!strncmp(buf, "load", 4)) {
403 lp5521_stop_engine(chip);
404 lp5521_load_engine(chip);
405 engine->mode = LP55XX_ENGINE_LOAD;
406 } else if (!strncmp(buf, "disabled", 8)) {
407 lp5521_stop_engine(chip);
408 engine->mode = LP55XX_ENGINE_DISABLED;
409 }
410
411 mutex_unlock(&chip->lock);
412
413 return len;
414 }
415 store_mode(1)
416 store_mode(2)
417 store_mode(3)
418
store_engine_load(struct device * dev,struct device_attribute * attr,const char * buf,size_t len,int nr)419 static ssize_t store_engine_load(struct device *dev,
420 struct device_attribute *attr,
421 const char *buf, size_t len, int nr)
422 {
423 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
424 struct lp55xx_chip *chip = led->chip;
425 int ret;
426
427 mutex_lock(&chip->lock);
428
429 chip->engine_idx = nr;
430 lp5521_load_engine(chip);
431 ret = lp5521_update_program_memory(chip, buf, len);
432
433 mutex_unlock(&chip->lock);
434
435 return ret;
436 }
437 store_load(1)
438 store_load(2)
439 store_load(3)
440
lp5521_selftest(struct device * dev,struct device_attribute * attr,char * buf)441 static ssize_t lp5521_selftest(struct device *dev,
442 struct device_attribute *attr,
443 char *buf)
444 {
445 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
446 struct lp55xx_chip *chip = led->chip;
447 int ret;
448
449 mutex_lock(&chip->lock);
450 ret = lp5521_run_selftest(chip, buf);
451 mutex_unlock(&chip->lock);
452
453 return scnprintf(buf, PAGE_SIZE, "%s\n", ret ? "FAIL" : "OK");
454 }
455
456 /* device attributes */
457 static LP55XX_DEV_ATTR_RW(engine1_mode, show_engine1_mode, store_engine1_mode);
458 static LP55XX_DEV_ATTR_RW(engine2_mode, show_engine2_mode, store_engine2_mode);
459 static LP55XX_DEV_ATTR_RW(engine3_mode, show_engine3_mode, store_engine3_mode);
460 static LP55XX_DEV_ATTR_WO(engine1_load, store_engine1_load);
461 static LP55XX_DEV_ATTR_WO(engine2_load, store_engine2_load);
462 static LP55XX_DEV_ATTR_WO(engine3_load, store_engine3_load);
463 static LP55XX_DEV_ATTR_RO(selftest, lp5521_selftest);
464
465 static struct attribute *lp5521_attributes[] = {
466 &dev_attr_engine1_mode.attr,
467 &dev_attr_engine2_mode.attr,
468 &dev_attr_engine3_mode.attr,
469 &dev_attr_engine1_load.attr,
470 &dev_attr_engine2_load.attr,
471 &dev_attr_engine3_load.attr,
472 &dev_attr_selftest.attr,
473 NULL
474 };
475
476 static const struct attribute_group lp5521_group = {
477 .attrs = lp5521_attributes,
478 };
479
480 /* Chip specific configurations */
481 static struct lp55xx_device_config lp5521_cfg = {
482 .reset = {
483 .addr = LP5521_REG_RESET,
484 .val = LP5521_RESET,
485 },
486 .enable = {
487 .addr = LP5521_REG_ENABLE,
488 .val = LP5521_ENABLE_DEFAULT,
489 },
490 .max_channel = LP5521_MAX_LEDS,
491 .post_init_device = lp5521_post_init_device,
492 .brightness_fn = lp5521_led_brightness,
493 .set_led_current = lp5521_set_led_current,
494 .firmware_cb = lp5521_firmware_loaded,
495 .run_engine = lp5521_run_engine,
496 .dev_attr_group = &lp5521_group,
497 };
498
lp5521_probe(struct i2c_client * client,const struct i2c_device_id * id)499 static int lp5521_probe(struct i2c_client *client,
500 const struct i2c_device_id *id)
501 {
502 int ret;
503 struct lp55xx_chip *chip;
504 struct lp55xx_led *led;
505 struct lp55xx_platform_data *pdata = dev_get_platdata(&client->dev);
506 struct device_node *np = client->dev.of_node;
507
508 if (!pdata) {
509 if (np) {
510 pdata = lp55xx_of_populate_pdata(&client->dev, np);
511 if (IS_ERR(pdata))
512 return PTR_ERR(pdata);
513 } else {
514 dev_err(&client->dev, "no platform data\n");
515 return -EINVAL;
516 }
517 }
518
519 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
520 if (!chip)
521 return -ENOMEM;
522
523 led = devm_kcalloc(&client->dev,
524 pdata->num_channels, sizeof(*led), GFP_KERNEL);
525 if (!led)
526 return -ENOMEM;
527
528 chip->cl = client;
529 chip->pdata = pdata;
530 chip->cfg = &lp5521_cfg;
531
532 mutex_init(&chip->lock);
533
534 i2c_set_clientdata(client, led);
535
536 ret = lp55xx_init_device(chip);
537 if (ret)
538 goto err_init;
539
540 dev_info(&client->dev, "%s programmable led chip found\n", id->name);
541
542 ret = lp55xx_register_leds(led, chip);
543 if (ret)
544 goto err_register_leds;
545
546 ret = lp55xx_register_sysfs(chip);
547 if (ret) {
548 dev_err(&client->dev, "registering sysfs failed\n");
549 goto err_register_sysfs;
550 }
551
552 return 0;
553
554 err_register_sysfs:
555 lp55xx_unregister_leds(led, chip);
556 err_register_leds:
557 lp55xx_deinit_device(chip);
558 err_init:
559 return ret;
560 }
561
lp5521_remove(struct i2c_client * client)562 static int lp5521_remove(struct i2c_client *client)
563 {
564 struct lp55xx_led *led = i2c_get_clientdata(client);
565 struct lp55xx_chip *chip = led->chip;
566
567 lp5521_stop_all_engines(chip);
568 lp55xx_unregister_sysfs(chip);
569 lp55xx_unregister_leds(led, chip);
570 lp55xx_deinit_device(chip);
571
572 return 0;
573 }
574
575 static const struct i2c_device_id lp5521_id[] = {
576 { "lp5521", 0 }, /* Three channel chip */
577 { }
578 };
579 MODULE_DEVICE_TABLE(i2c, lp5521_id);
580
581 #ifdef CONFIG_OF
582 static const struct of_device_id of_lp5521_leds_match[] = {
583 { .compatible = "national,lp5521", },
584 {},
585 };
586
587 MODULE_DEVICE_TABLE(of, of_lp5521_leds_match);
588 #endif
589 static struct i2c_driver lp5521_driver = {
590 .driver = {
591 .name = "lp5521",
592 .of_match_table = of_match_ptr(of_lp5521_leds_match),
593 },
594 .probe = lp5521_probe,
595 .remove = lp5521_remove,
596 .id_table = lp5521_id,
597 };
598
599 module_i2c_driver(lp5521_driver);
600
601 MODULE_AUTHOR("Mathias Nyman, Yuri Zaporozhets, Samu Onkalo");
602 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
603 MODULE_DESCRIPTION("LP5521 LED engine");
604 MODULE_LICENSE("GPL v2");
605