1/*
2 * TI LP8501 9 channel LED Driver
3 *
4 * Copyright (C) 2013 Texas Instruments
5 *
6 * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * version 2 as published by the Free Software Foundation.
11 *
12 */
13
14#include <linux/delay.h>
15#include <linux/firmware.h>
16#include <linux/i2c.h>
17#include <linux/init.h>
18#include <linux/leds.h>
19#include <linux/module.h>
20#include <linux/mutex.h>
21#include <linux/of.h>
22#include <linux/platform_data/leds-lp55xx.h>
23#include <linux/slab.h>
24
25#include "leds-lp55xx-common.h"
26
27#define LP8501_PROGRAM_LENGTH		32
28#define LP8501_MAX_LEDS			9
29
30/* Registers */
31#define LP8501_REG_ENABLE		0x00
32#define LP8501_ENABLE			BIT(6)
33#define LP8501_EXEC_M			0x3F
34#define LP8501_EXEC_ENG1_M		0x30
35#define LP8501_EXEC_ENG2_M		0x0C
36#define LP8501_EXEC_ENG3_M		0x03
37#define LP8501_RUN_ENG1			0x20
38#define LP8501_RUN_ENG2			0x08
39#define LP8501_RUN_ENG3			0x02
40
41#define LP8501_REG_OP_MODE		0x01
42#define LP8501_MODE_ENG1_M		0x30
43#define LP8501_MODE_ENG2_M		0x0C
44#define LP8501_MODE_ENG3_M		0x03
45#define LP8501_LOAD_ENG1		0x10
46#define LP8501_LOAD_ENG2		0x04
47#define LP8501_LOAD_ENG3		0x01
48
49#define LP8501_REG_PWR_CONFIG		0x05
50#define LP8501_PWR_CONFIG_M		0x03
51
52#define LP8501_REG_LED_PWM_BASE		0x16
53
54#define LP8501_REG_LED_CURRENT_BASE	0x26
55
56#define LP8501_REG_CONFIG		0x36
57#define LP8501_PWM_PSAVE		BIT(7)
58#define LP8501_AUTO_INC			BIT(6)
59#define LP8501_PWR_SAVE			BIT(5)
60#define LP8501_CP_AUTO			0x18
61#define LP8501_INT_CLK			BIT(0)
62#define LP8501_DEFAULT_CFG	\
63	(LP8501_PWM_PSAVE | LP8501_AUTO_INC | LP8501_PWR_SAVE | LP8501_CP_AUTO)
64
65#define LP8501_REG_RESET		0x3D
66#define LP8501_RESET			0xFF
67
68#define LP8501_REG_PROG_PAGE_SEL	0x4F
69#define LP8501_PAGE_ENG1		0
70#define LP8501_PAGE_ENG2		1
71#define LP8501_PAGE_ENG3		2
72
73#define LP8501_REG_PROG_MEM		0x50
74
75#define LP8501_ENG1_IS_LOADING(mode)	\
76	((mode & LP8501_MODE_ENG1_M) == LP8501_LOAD_ENG1)
77#define LP8501_ENG2_IS_LOADING(mode)	\
78	((mode & LP8501_MODE_ENG2_M) == LP8501_LOAD_ENG2)
79#define LP8501_ENG3_IS_LOADING(mode)	\
80	((mode & LP8501_MODE_ENG3_M) == LP8501_LOAD_ENG3)
81
82static inline void lp8501_wait_opmode_done(void)
83{
84	usleep_range(1000, 2000);
85}
86
87static void lp8501_set_led_current(struct lp55xx_led *led, u8 led_current)
88{
89	led->led_current = led_current;
90	lp55xx_write(led->chip, LP8501_REG_LED_CURRENT_BASE + led->chan_nr,
91		led_current);
92}
93
94static int lp8501_post_init_device(struct lp55xx_chip *chip)
95{
96	int ret;
97	u8 val = LP8501_DEFAULT_CFG;
98
99	ret = lp55xx_write(chip, LP8501_REG_ENABLE, LP8501_ENABLE);
100	if (ret)
101		return ret;
102
103	/* Chip startup time is 500 us, 1 - 2 ms gives some margin */
104	usleep_range(1000, 2000);
105
106	if (chip->pdata->clock_mode != LP55XX_CLOCK_EXT)
107		val |= LP8501_INT_CLK;
108
109	ret = lp55xx_write(chip, LP8501_REG_CONFIG, val);
110	if (ret)
111		return ret;
112
113	/* Power selection for each output */
114	return lp55xx_update_bits(chip, LP8501_REG_PWR_CONFIG,
115				LP8501_PWR_CONFIG_M, chip->pdata->pwr_sel);
116}
117
118static void lp8501_load_engine(struct lp55xx_chip *chip)
119{
120	enum lp55xx_engine_index idx = chip->engine_idx;
121	u8 mask[] = {
122		[LP55XX_ENGINE_1] = LP8501_MODE_ENG1_M,
123		[LP55XX_ENGINE_2] = LP8501_MODE_ENG2_M,
124		[LP55XX_ENGINE_3] = LP8501_MODE_ENG3_M,
125	};
126
127	u8 val[] = {
128		[LP55XX_ENGINE_1] = LP8501_LOAD_ENG1,
129		[LP55XX_ENGINE_2] = LP8501_LOAD_ENG2,
130		[LP55XX_ENGINE_3] = LP8501_LOAD_ENG3,
131	};
132
133	u8 page_sel[] = {
134		[LP55XX_ENGINE_1] = LP8501_PAGE_ENG1,
135		[LP55XX_ENGINE_2] = LP8501_PAGE_ENG2,
136		[LP55XX_ENGINE_3] = LP8501_PAGE_ENG3,
137	};
138
139	lp55xx_update_bits(chip, LP8501_REG_OP_MODE, mask[idx], val[idx]);
140
141	lp8501_wait_opmode_done();
142
143	lp55xx_write(chip, LP8501_REG_PROG_PAGE_SEL, page_sel[idx]);
144}
145
146static void lp8501_stop_engine(struct lp55xx_chip *chip)
147{
148	lp55xx_write(chip, LP8501_REG_OP_MODE, 0);
149	lp8501_wait_opmode_done();
150}
151
152static void lp8501_turn_off_channels(struct lp55xx_chip *chip)
153{
154	int i;
155
156	for (i = 0; i < LP8501_MAX_LEDS; i++)
157		lp55xx_write(chip, LP8501_REG_LED_PWM_BASE + i, 0);
158}
159
160static void lp8501_run_engine(struct lp55xx_chip *chip, bool start)
161{
162	int ret;
163	u8 mode;
164	u8 exec;
165
166	/* stop engine */
167	if (!start) {
168		lp8501_stop_engine(chip);
169		lp8501_turn_off_channels(chip);
170		return;
171	}
172
173	/*
174	 * To run the engine,
175	 * operation mode and enable register should updated at the same time
176	 */
177
178	ret = lp55xx_read(chip, LP8501_REG_OP_MODE, &mode);
179	if (ret)
180		return;
181
182	ret = lp55xx_read(chip, LP8501_REG_ENABLE, &exec);
183	if (ret)
184		return;
185
186	/* change operation mode to RUN only when each engine is loading */
187	if (LP8501_ENG1_IS_LOADING(mode)) {
188		mode = (mode & ~LP8501_MODE_ENG1_M) | LP8501_RUN_ENG1;
189		exec = (exec & ~LP8501_EXEC_ENG1_M) | LP8501_RUN_ENG1;
190	}
191
192	if (LP8501_ENG2_IS_LOADING(mode)) {
193		mode = (mode & ~LP8501_MODE_ENG2_M) | LP8501_RUN_ENG2;
194		exec = (exec & ~LP8501_EXEC_ENG2_M) | LP8501_RUN_ENG2;
195	}
196
197	if (LP8501_ENG3_IS_LOADING(mode)) {
198		mode = (mode & ~LP8501_MODE_ENG3_M) | LP8501_RUN_ENG3;
199		exec = (exec & ~LP8501_EXEC_ENG3_M) | LP8501_RUN_ENG3;
200	}
201
202	lp55xx_write(chip, LP8501_REG_OP_MODE, mode);
203	lp8501_wait_opmode_done();
204
205	lp55xx_update_bits(chip, LP8501_REG_ENABLE, LP8501_EXEC_M, exec);
206}
207
208static int lp8501_update_program_memory(struct lp55xx_chip *chip,
209					const u8 *data, size_t size)
210{
211	u8 pattern[LP8501_PROGRAM_LENGTH] = {0};
212	unsigned cmd;
213	char c[3];
214	int update_size;
215	int nrchars;
216	int offset = 0;
217	int ret;
218	int i;
219
220	/* clear program memory before updating */
221	for (i = 0; i < LP8501_PROGRAM_LENGTH; i++)
222		lp55xx_write(chip, LP8501_REG_PROG_MEM + i, 0);
223
224	i = 0;
225	while ((offset < size - 1) && (i < LP8501_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	update_size = i;
245	for (i = 0; i < update_size; i++)
246		lp55xx_write(chip, LP8501_REG_PROG_MEM + i, pattern[i]);
247
248	return 0;
249
250err:
251	dev_err(&chip->cl->dev, "wrong pattern format\n");
252	return -EINVAL;
253}
254
255static void lp8501_firmware_loaded(struct lp55xx_chip *chip)
256{
257	const struct firmware *fw = chip->fw;
258
259	if (fw->size > LP8501_PROGRAM_LENGTH) {
260		dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
261			fw->size);
262		return;
263	}
264
265	/*
266	 * Program memory sequence
267	 *  1) set engine mode to "LOAD"
268	 *  2) write firmware data into program memory
269	 */
270
271	lp8501_load_engine(chip);
272	lp8501_update_program_memory(chip, fw->data, fw->size);
273}
274
275static void lp8501_led_brightness_work(struct work_struct *work)
276{
277	struct lp55xx_led *led = container_of(work, struct lp55xx_led,
278					      brightness_work);
279	struct lp55xx_chip *chip = led->chip;
280
281	mutex_lock(&chip->lock);
282	lp55xx_write(chip, LP8501_REG_LED_PWM_BASE + led->chan_nr,
283		     led->brightness);
284	mutex_unlock(&chip->lock);
285}
286
287/* Chip specific configurations */
288static struct lp55xx_device_config lp8501_cfg = {
289	.reset = {
290		.addr = LP8501_REG_RESET,
291		.val  = LP8501_RESET,
292	},
293	.enable = {
294		.addr = LP8501_REG_ENABLE,
295		.val  = LP8501_ENABLE,
296	},
297	.max_channel  = LP8501_MAX_LEDS,
298	.post_init_device   = lp8501_post_init_device,
299	.brightness_work_fn = lp8501_led_brightness_work,
300	.set_led_current    = lp8501_set_led_current,
301	.firmware_cb        = lp8501_firmware_loaded,
302	.run_engine         = lp8501_run_engine,
303};
304
305static int lp8501_probe(struct i2c_client *client,
306			const struct i2c_device_id *id)
307{
308	int ret;
309	struct lp55xx_chip *chip;
310	struct lp55xx_led *led;
311	struct lp55xx_platform_data *pdata = dev_get_platdata(&client->dev);
312	struct device_node *np = client->dev.of_node;
313
314	if (!pdata) {
315		if (np) {
316			pdata = lp55xx_of_populate_pdata(&client->dev, np);
317			if (IS_ERR(pdata))
318				return PTR_ERR(pdata);
319		} else {
320			dev_err(&client->dev, "no platform data\n");
321			return -EINVAL;
322		}
323	}
324
325	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
326	if (!chip)
327		return -ENOMEM;
328
329	led = devm_kzalloc(&client->dev,
330			sizeof(*led) * pdata->num_channels, GFP_KERNEL);
331	if (!led)
332		return -ENOMEM;
333
334	chip->cl = client;
335	chip->pdata = pdata;
336	chip->cfg = &lp8501_cfg;
337
338	mutex_init(&chip->lock);
339
340	i2c_set_clientdata(client, led);
341
342	ret = lp55xx_init_device(chip);
343	if (ret)
344		goto err_init;
345
346	dev_info(&client->dev, "%s Programmable led chip found\n", id->name);
347
348	ret = lp55xx_register_leds(led, chip);
349	if (ret)
350		goto err_register_leds;
351
352	ret = lp55xx_register_sysfs(chip);
353	if (ret) {
354		dev_err(&client->dev, "registering sysfs failed\n");
355		goto err_register_sysfs;
356	}
357
358	return 0;
359
360err_register_sysfs:
361	lp55xx_unregister_leds(led, chip);
362err_register_leds:
363	lp55xx_deinit_device(chip);
364err_init:
365	return ret;
366}
367
368static int lp8501_remove(struct i2c_client *client)
369{
370	struct lp55xx_led *led = i2c_get_clientdata(client);
371	struct lp55xx_chip *chip = led->chip;
372
373	lp8501_stop_engine(chip);
374	lp55xx_unregister_sysfs(chip);
375	lp55xx_unregister_leds(led, chip);
376	lp55xx_deinit_device(chip);
377
378	return 0;
379}
380
381static const struct i2c_device_id lp8501_id[] = {
382	{ "lp8501",  0 },
383	{ }
384};
385MODULE_DEVICE_TABLE(i2c, lp8501_id);
386
387#ifdef CONFIG_OF
388static const struct of_device_id of_lp8501_leds_match[] = {
389	{ .compatible = "ti,lp8501", },
390	{},
391};
392
393MODULE_DEVICE_TABLE(of, of_lp8501_leds_match);
394#endif
395
396static struct i2c_driver lp8501_driver = {
397	.driver = {
398		.name	= "lp8501",
399		.of_match_table = of_match_ptr(of_lp8501_leds_match),
400	},
401	.probe		= lp8501_probe,
402	.remove		= lp8501_remove,
403	.id_table	= lp8501_id,
404};
405
406module_i2c_driver(lp8501_driver);
407
408MODULE_DESCRIPTION("Texas Instruments LP8501 LED driver");
409MODULE_AUTHOR("Milo Kim");
410MODULE_LICENSE("GPL");
411