1/*
2 * LP5521 LED chip driver.
3 *
4 * Copyright (C) 2010 Nokia Corporation
5 * Copyright (C) 2012 Texas Instruments
6 *
7 * Contact: Samu Onkalo <samu.p.onkalo@nokia.com>
8 *          Milo(Woogyom) Kim <milo.kim@ti.com>
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * version 2 as published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
22 * 02110-1301 USA
23 */
24
25#include <linux/delay.h>
26#include <linux/firmware.h>
27#include <linux/i2c.h>
28#include <linux/leds.h>
29#include <linux/module.h>
30#include <linux/mutex.h>
31#include <linux/platform_data/leds-lp55xx.h>
32#include <linux/slab.h>
33#include <linux/of.h>
34
35#include "leds-lp55xx-common.h"
36
37#define LP5521_PROGRAM_LENGTH		32
38#define LP5521_MAX_LEDS			3
39#define LP5521_CMD_DIRECT		0x3F
40
41/* Registers */
42#define LP5521_REG_ENABLE		0x00
43#define LP5521_REG_OP_MODE		0x01
44#define LP5521_REG_R_PWM		0x02
45#define LP5521_REG_G_PWM		0x03
46#define LP5521_REG_B_PWM		0x04
47#define LP5521_REG_R_CURRENT		0x05
48#define LP5521_REG_G_CURRENT		0x06
49#define LP5521_REG_B_CURRENT		0x07
50#define LP5521_REG_CONFIG		0x08
51#define LP5521_REG_STATUS		0x0C
52#define LP5521_REG_RESET		0x0D
53#define LP5521_REG_R_PROG_MEM		0x10
54#define LP5521_REG_G_PROG_MEM		0x30
55#define LP5521_REG_B_PROG_MEM		0x50
56
57/* Base register to set LED current */
58#define LP5521_REG_LED_CURRENT_BASE	LP5521_REG_R_CURRENT
59/* Base register to set the brightness */
60#define LP5521_REG_LED_PWM_BASE		LP5521_REG_R_PWM
61
62/* Bits in ENABLE register */
63#define LP5521_MASTER_ENABLE		0x40	/* Chip master enable */
64#define LP5521_LOGARITHMIC_PWM		0x80	/* Logarithmic PWM adjustment */
65#define LP5521_EXEC_RUN			0x2A
66#define LP5521_ENABLE_DEFAULT	\
67	(LP5521_MASTER_ENABLE | LP5521_LOGARITHMIC_PWM)
68#define LP5521_ENABLE_RUN_PROGRAM	\
69	(LP5521_ENABLE_DEFAULT | LP5521_EXEC_RUN)
70
71/* CONFIG register */
72#define LP5521_PWM_HF			0x40	/* PWM: 0 = 256Hz, 1 = 558Hz */
73#define LP5521_PWRSAVE_EN		0x20	/* 1 = Power save mode */
74#define LP5521_CP_MODE_OFF		0	/* Charge pump (CP) off */
75#define LP5521_CP_MODE_BYPASS		8	/* CP forced to bypass mode */
76#define LP5521_CP_MODE_1X5		0x10	/* CP forced to 1.5x mode */
77#define LP5521_CP_MODE_AUTO		0x18	/* Automatic mode selection */
78#define LP5521_R_TO_BATT		0x04	/* R out: 0 = CP, 1 = Vbat */
79#define LP5521_CLK_INT			0x01	/* Internal clock */
80#define LP5521_DEFAULT_CFG		\
81	(LP5521_PWM_HF | LP5521_PWRSAVE_EN | LP5521_CP_MODE_AUTO)
82
83/* Status */
84#define LP5521_EXT_CLK_USED		0x08
85
86/* default R channel current register value */
87#define LP5521_REG_R_CURR_DEFAULT	0xAF
88
89/* Reset register value */
90#define LP5521_RESET			0xFF
91
92/* Program Memory Operations */
93#define LP5521_MODE_R_M			0x30	/* Operation Mode Register */
94#define LP5521_MODE_G_M			0x0C
95#define LP5521_MODE_B_M			0x03
96#define LP5521_LOAD_R			0x10
97#define LP5521_LOAD_G			0x04
98#define LP5521_LOAD_B			0x01
99
100#define LP5521_R_IS_LOADING(mode)	\
101	((mode & LP5521_MODE_R_M) == LP5521_LOAD_R)
102#define LP5521_G_IS_LOADING(mode)	\
103	((mode & LP5521_MODE_G_M) == LP5521_LOAD_G)
104#define LP5521_B_IS_LOADING(mode)	\
105	((mode & LP5521_MODE_B_M) == LP5521_LOAD_B)
106
107#define LP5521_EXEC_R_M			0x30	/* Enable Register */
108#define LP5521_EXEC_G_M			0x0C
109#define LP5521_EXEC_B_M			0x03
110#define LP5521_EXEC_M			0x3F
111#define LP5521_RUN_R			0x20
112#define LP5521_RUN_G			0x08
113#define LP5521_RUN_B			0x02
114
115static inline void lp5521_wait_opmode_done(void)
116{
117	/* operation mode change needs to be longer than 153 us */
118	usleep_range(200, 300);
119}
120
121static inline void lp5521_wait_enable_done(void)
122{
123	/* it takes more 488 us to update ENABLE register */
124	usleep_range(500, 600);
125}
126
127static void lp5521_set_led_current(struct lp55xx_led *led, u8 led_current)
128{
129	led->led_current = led_current;
130	lp55xx_write(led->chip, LP5521_REG_LED_CURRENT_BASE + led->chan_nr,
131		led_current);
132}
133
134static void lp5521_load_engine(struct lp55xx_chip *chip)
135{
136	enum lp55xx_engine_index idx = chip->engine_idx;
137	u8 mask[] = {
138		[LP55XX_ENGINE_1] = LP5521_MODE_R_M,
139		[LP55XX_ENGINE_2] = LP5521_MODE_G_M,
140		[LP55XX_ENGINE_3] = LP5521_MODE_B_M,
141	};
142
143	u8 val[] = {
144		[LP55XX_ENGINE_1] = LP5521_LOAD_R,
145		[LP55XX_ENGINE_2] = LP5521_LOAD_G,
146		[LP55XX_ENGINE_3] = LP5521_LOAD_B,
147	};
148
149	lp55xx_update_bits(chip, LP5521_REG_OP_MODE, mask[idx], val[idx]);
150
151	lp5521_wait_opmode_done();
152}
153
154static void lp5521_stop_all_engines(struct lp55xx_chip *chip)
155{
156	lp55xx_write(chip, LP5521_REG_OP_MODE, 0);
157	lp5521_wait_opmode_done();
158}
159
160static void lp5521_stop_engine(struct lp55xx_chip *chip)
161{
162	enum lp55xx_engine_index idx = chip->engine_idx;
163	u8 mask[] = {
164		[LP55XX_ENGINE_1] = LP5521_MODE_R_M,
165		[LP55XX_ENGINE_2] = LP5521_MODE_G_M,
166		[LP55XX_ENGINE_3] = LP5521_MODE_B_M,
167	};
168
169	lp55xx_update_bits(chip, LP5521_REG_OP_MODE, mask[idx], 0);
170
171	lp5521_wait_opmode_done();
172}
173
174static void lp5521_run_engine(struct lp55xx_chip *chip, bool start)
175{
176	int ret;
177	u8 mode;
178	u8 exec;
179
180	/* stop engine */
181	if (!start) {
182		lp5521_stop_engine(chip);
183		lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
184		lp5521_wait_opmode_done();
185		return;
186	}
187
188	/*
189	 * To run the engine,
190	 * operation mode and enable register should updated at the same time
191	 */
192
193	ret = lp55xx_read(chip, LP5521_REG_OP_MODE, &mode);
194	if (ret)
195		return;
196
197	ret = lp55xx_read(chip, LP5521_REG_ENABLE, &exec);
198	if (ret)
199		return;
200
201	/* change operation mode to RUN only when each engine is loading */
202	if (LP5521_R_IS_LOADING(mode)) {
203		mode = (mode & ~LP5521_MODE_R_M) | LP5521_RUN_R;
204		exec = (exec & ~LP5521_EXEC_R_M) | LP5521_RUN_R;
205	}
206
207	if (LP5521_G_IS_LOADING(mode)) {
208		mode = (mode & ~LP5521_MODE_G_M) | LP5521_RUN_G;
209		exec = (exec & ~LP5521_EXEC_G_M) | LP5521_RUN_G;
210	}
211
212	if (LP5521_B_IS_LOADING(mode)) {
213		mode = (mode & ~LP5521_MODE_B_M) | LP5521_RUN_B;
214		exec = (exec & ~LP5521_EXEC_B_M) | LP5521_RUN_B;
215	}
216
217	lp55xx_write(chip, LP5521_REG_OP_MODE, mode);
218	lp5521_wait_opmode_done();
219
220	lp55xx_update_bits(chip, LP5521_REG_ENABLE, LP5521_EXEC_M, exec);
221	lp5521_wait_enable_done();
222}
223
224static int lp5521_update_program_memory(struct lp55xx_chip *chip,
225					const u8 *data, size_t size)
226{
227	enum lp55xx_engine_index idx = chip->engine_idx;
228	u8 pattern[LP5521_PROGRAM_LENGTH] = {0};
229	u8 addr[] = {
230		[LP55XX_ENGINE_1] = LP5521_REG_R_PROG_MEM,
231		[LP55XX_ENGINE_2] = LP5521_REG_G_PROG_MEM,
232		[LP55XX_ENGINE_3] = LP5521_REG_B_PROG_MEM,
233	};
234	unsigned cmd;
235	char c[3];
236	int nrchars;
237	int ret;
238	int offset = 0;
239	int i = 0;
240
241	while ((offset < size - 1) && (i < LP5521_PROGRAM_LENGTH)) {
242		/* separate sscanfs because length is working only for %s */
243		ret = sscanf(data + offset, "%2s%n ", c, &nrchars);
244		if (ret != 1)
245			goto err;
246
247		ret = sscanf(c, "%2x", &cmd);
248		if (ret != 1)
249			goto err;
250
251		pattern[i] = (u8)cmd;
252		offset += nrchars;
253		i++;
254	}
255
256	/* Each instruction is 16bit long. Check that length is even */
257	if (i % 2)
258		goto err;
259
260	for (i = 0; i < LP5521_PROGRAM_LENGTH; i++) {
261		ret = lp55xx_write(chip, addr[idx] + i, pattern[i]);
262		if (ret)
263			return -EINVAL;
264	}
265
266	return size;
267
268err:
269	dev_err(&chip->cl->dev, "wrong pattern format\n");
270	return -EINVAL;
271}
272
273static void lp5521_firmware_loaded(struct lp55xx_chip *chip)
274{
275	const struct firmware *fw = chip->fw;
276
277	if (fw->size > LP5521_PROGRAM_LENGTH) {
278		dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
279			fw->size);
280		return;
281	}
282
283	/*
284	 * Program momery sequence
285	 *  1) set engine mode to "LOAD"
286	 *  2) write firmware data into program memory
287	 */
288
289	lp5521_load_engine(chip);
290	lp5521_update_program_memory(chip, fw->data, fw->size);
291}
292
293static int lp5521_post_init_device(struct lp55xx_chip *chip)
294{
295	int ret;
296	u8 val;
297
298	/*
299	 * Make sure that the chip is reset by reading back the r channel
300	 * current reg. This is dummy read is required on some platforms -
301	 * otherwise further access to the R G B channels in the
302	 * LP5521_REG_ENABLE register will not have any effect - strange!
303	 */
304	ret = lp55xx_read(chip, LP5521_REG_R_CURRENT, &val);
305	if (ret) {
306		dev_err(&chip->cl->dev, "error in resetting chip\n");
307		return ret;
308	}
309	if (val != LP5521_REG_R_CURR_DEFAULT) {
310		dev_err(&chip->cl->dev,
311			"unexpected data in register (expected 0x%x got 0x%x)\n",
312			LP5521_REG_R_CURR_DEFAULT, val);
313		ret = -EINVAL;
314		return ret;
315	}
316	usleep_range(10000, 20000);
317
318	/* Set all PWMs to direct control mode */
319	ret = lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
320
321	/* Update configuration for the clock setting */
322	val = LP5521_DEFAULT_CFG;
323	if (!lp55xx_is_extclk_used(chip))
324		val |= LP5521_CLK_INT;
325
326	ret = lp55xx_write(chip, LP5521_REG_CONFIG, val);
327	if (ret)
328		return ret;
329
330	/* Initialize all channels PWM to zero -> leds off */
331	lp55xx_write(chip, LP5521_REG_R_PWM, 0);
332	lp55xx_write(chip, LP5521_REG_G_PWM, 0);
333	lp55xx_write(chip, LP5521_REG_B_PWM, 0);
334
335	/* Set engines are set to run state when OP_MODE enables engines */
336	ret = lp55xx_write(chip, LP5521_REG_ENABLE, LP5521_ENABLE_RUN_PROGRAM);
337	if (ret)
338		return ret;
339
340	lp5521_wait_enable_done();
341
342	return 0;
343}
344
345static int lp5521_run_selftest(struct lp55xx_chip *chip, char *buf)
346{
347	struct lp55xx_platform_data *pdata = chip->pdata;
348	int ret;
349	u8 status;
350
351	ret = lp55xx_read(chip, LP5521_REG_STATUS, &status);
352	if (ret < 0)
353		return ret;
354
355	if (pdata->clock_mode != LP55XX_CLOCK_EXT)
356		return 0;
357
358	/* Check that ext clock is really in use if requested */
359	if  ((status & LP5521_EXT_CLK_USED) == 0)
360		return -EIO;
361
362	return 0;
363}
364
365static void lp5521_led_brightness_work(struct work_struct *work)
366{
367	struct lp55xx_led *led = container_of(work, struct lp55xx_led,
368					      brightness_work);
369	struct lp55xx_chip *chip = led->chip;
370
371	mutex_lock(&chip->lock);
372	lp55xx_write(chip, LP5521_REG_LED_PWM_BASE + led->chan_nr,
373		led->brightness);
374	mutex_unlock(&chip->lock);
375}
376
377static ssize_t show_engine_mode(struct device *dev,
378				struct device_attribute *attr,
379				char *buf, int nr)
380{
381	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
382	struct lp55xx_chip *chip = led->chip;
383	enum lp55xx_engine_mode mode = chip->engines[nr - 1].mode;
384
385	switch (mode) {
386	case LP55XX_ENGINE_RUN:
387		return sprintf(buf, "run\n");
388	case LP55XX_ENGINE_LOAD:
389		return sprintf(buf, "load\n");
390	case LP55XX_ENGINE_DISABLED:
391	default:
392		return sprintf(buf, "disabled\n");
393	}
394}
395show_mode(1)
396show_mode(2)
397show_mode(3)
398
399static ssize_t store_engine_mode(struct device *dev,
400				 struct device_attribute *attr,
401				 const char *buf, size_t len, int nr)
402{
403	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
404	struct lp55xx_chip *chip = led->chip;
405	struct lp55xx_engine *engine = &chip->engines[nr - 1];
406
407	mutex_lock(&chip->lock);
408
409	chip->engine_idx = nr;
410
411	if (!strncmp(buf, "run", 3)) {
412		lp5521_run_engine(chip, true);
413		engine->mode = LP55XX_ENGINE_RUN;
414	} else if (!strncmp(buf, "load", 4)) {
415		lp5521_stop_engine(chip);
416		lp5521_load_engine(chip);
417		engine->mode = LP55XX_ENGINE_LOAD;
418	} else if (!strncmp(buf, "disabled", 8)) {
419		lp5521_stop_engine(chip);
420		engine->mode = LP55XX_ENGINE_DISABLED;
421	}
422
423	mutex_unlock(&chip->lock);
424
425	return len;
426}
427store_mode(1)
428store_mode(2)
429store_mode(3)
430
431static ssize_t store_engine_load(struct device *dev,
432			     struct device_attribute *attr,
433			     const char *buf, size_t len, int nr)
434{
435	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
436	struct lp55xx_chip *chip = led->chip;
437	int ret;
438
439	mutex_lock(&chip->lock);
440
441	chip->engine_idx = nr;
442	lp5521_load_engine(chip);
443	ret = lp5521_update_program_memory(chip, buf, len);
444
445	mutex_unlock(&chip->lock);
446
447	return ret;
448}
449store_load(1)
450store_load(2)
451store_load(3)
452
453static ssize_t lp5521_selftest(struct device *dev,
454			       struct device_attribute *attr,
455			       char *buf)
456{
457	struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
458	struct lp55xx_chip *chip = led->chip;
459	int ret;
460
461	mutex_lock(&chip->lock);
462	ret = lp5521_run_selftest(chip, buf);
463	mutex_unlock(&chip->lock);
464
465	return scnprintf(buf, PAGE_SIZE, "%s\n", ret ? "FAIL" : "OK");
466}
467
468/* device attributes */
469static LP55XX_DEV_ATTR_RW(engine1_mode, show_engine1_mode, store_engine1_mode);
470static LP55XX_DEV_ATTR_RW(engine2_mode, show_engine2_mode, store_engine2_mode);
471static LP55XX_DEV_ATTR_RW(engine3_mode, show_engine3_mode, store_engine3_mode);
472static LP55XX_DEV_ATTR_WO(engine1_load, store_engine1_load);
473static LP55XX_DEV_ATTR_WO(engine2_load, store_engine2_load);
474static LP55XX_DEV_ATTR_WO(engine3_load, store_engine3_load);
475static LP55XX_DEV_ATTR_RO(selftest, lp5521_selftest);
476
477static struct attribute *lp5521_attributes[] = {
478	&dev_attr_engine1_mode.attr,
479	&dev_attr_engine2_mode.attr,
480	&dev_attr_engine3_mode.attr,
481	&dev_attr_engine1_load.attr,
482	&dev_attr_engine2_load.attr,
483	&dev_attr_engine3_load.attr,
484	&dev_attr_selftest.attr,
485	NULL
486};
487
488static const struct attribute_group lp5521_group = {
489	.attrs = lp5521_attributes,
490};
491
492/* Chip specific configurations */
493static struct lp55xx_device_config lp5521_cfg = {
494	.reset = {
495		.addr = LP5521_REG_RESET,
496		.val  = LP5521_RESET,
497	},
498	.enable = {
499		.addr = LP5521_REG_ENABLE,
500		.val  = LP5521_ENABLE_DEFAULT,
501	},
502	.max_channel  = LP5521_MAX_LEDS,
503	.post_init_device   = lp5521_post_init_device,
504	.brightness_work_fn = lp5521_led_brightness_work,
505	.set_led_current    = lp5521_set_led_current,
506	.firmware_cb        = lp5521_firmware_loaded,
507	.run_engine         = lp5521_run_engine,
508	.dev_attr_group     = &lp5521_group,
509};
510
511static int lp5521_probe(struct i2c_client *client,
512			const struct i2c_device_id *id)
513{
514	int ret;
515	struct lp55xx_chip *chip;
516	struct lp55xx_led *led;
517	struct lp55xx_platform_data *pdata;
518	struct device_node *np = client->dev.of_node;
519
520	if (!dev_get_platdata(&client->dev)) {
521		if (np) {
522			ret = lp55xx_of_populate_pdata(&client->dev, np);
523			if (ret < 0)
524				return ret;
525		} else {
526			dev_err(&client->dev, "no platform data\n");
527			return -EINVAL;
528		}
529	}
530	pdata = dev_get_platdata(&client->dev);
531
532	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
533	if (!chip)
534		return -ENOMEM;
535
536	led = devm_kzalloc(&client->dev,
537			sizeof(*led) * pdata->num_channels, GFP_KERNEL);
538	if (!led)
539		return -ENOMEM;
540
541	chip->cl = client;
542	chip->pdata = pdata;
543	chip->cfg = &lp5521_cfg;
544
545	mutex_init(&chip->lock);
546
547	i2c_set_clientdata(client, led);
548
549	ret = lp55xx_init_device(chip);
550	if (ret)
551		goto err_init;
552
553	dev_info(&client->dev, "%s programmable led chip found\n", id->name);
554
555	ret = lp55xx_register_leds(led, chip);
556	if (ret)
557		goto err_register_leds;
558
559	ret = lp55xx_register_sysfs(chip);
560	if (ret) {
561		dev_err(&client->dev, "registering sysfs failed\n");
562		goto err_register_sysfs;
563	}
564
565	return 0;
566
567err_register_sysfs:
568	lp55xx_unregister_leds(led, chip);
569err_register_leds:
570	lp55xx_deinit_device(chip);
571err_init:
572	return ret;
573}
574
575static int lp5521_remove(struct i2c_client *client)
576{
577	struct lp55xx_led *led = i2c_get_clientdata(client);
578	struct lp55xx_chip *chip = led->chip;
579
580	lp5521_stop_all_engines(chip);
581	lp55xx_unregister_sysfs(chip);
582	lp55xx_unregister_leds(led, chip);
583	lp55xx_deinit_device(chip);
584
585	return 0;
586}
587
588static const struct i2c_device_id lp5521_id[] = {
589	{ "lp5521", 0 }, /* Three channel chip */
590	{ }
591};
592MODULE_DEVICE_TABLE(i2c, lp5521_id);
593
594#ifdef CONFIG_OF
595static const struct of_device_id of_lp5521_leds_match[] = {
596	{ .compatible = "national,lp5521", },
597	{},
598};
599
600MODULE_DEVICE_TABLE(of, of_lp5521_leds_match);
601#endif
602static struct i2c_driver lp5521_driver = {
603	.driver = {
604		.name	= "lp5521",
605		.of_match_table = of_match_ptr(of_lp5521_leds_match),
606	},
607	.probe		= lp5521_probe,
608	.remove		= lp5521_remove,
609	.id_table	= lp5521_id,
610};
611
612module_i2c_driver(lp5521_driver);
613
614MODULE_AUTHOR("Mathias Nyman, Yuri Zaporozhets, Samu Onkalo");
615MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
616MODULE_DESCRIPTION("LP5521 LED engine");
617MODULE_LICENSE("GPL v2");
618