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(200, 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(500, 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(led->chip, LP5521_REG_LED_CURRENT_BASE + led->chan_nr,
115		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[idx], 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, 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[idx], 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, &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
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, addr[idx] + i, 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, fw->data, 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);
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	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, 0);
320	lp55xx_write(chip, LP5521_REG_G_PWM, 0);
321	lp55xx_write(chip, LP5521_REG_B_PWM, 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, &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				   led->mc_cdev.subled_info[i].brightness);
365		if (ret)
366			break;
367	}
368	mutex_unlock(&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		led->brightness);
380	mutex_unlock(&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, "run\n");
396	case LP55XX_ENGINE_LOAD:
397		return sprintf(buf, "load\n");
398	case LP55XX_ENGINE_DISABLED:
399	default:
400		return sprintf(buf, "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, 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(&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, buf, len);
452
453	mutex_unlock(&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(&chip->lock);
472
473	return sysfs_emit(buf, "%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(&client->dev);
527	struct device_node *np = dev_of_node(&client->dev);
528
529	chip = devm_kzalloc(&client->dev, 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(&client->dev, np,
538							 chip);
539			if (IS_ERR(pdata))
540				return PTR_ERR(pdata);
541		} else {
542			dev_err(&client->dev, "no platform data\n");
543			return -EINVAL;
544		}
545	}
546
547	led = devm_kcalloc(&client->dev,
548			pdata->num_channels, 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, 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