xref: /openbmc/linux/drivers/leds/leds-lp8501.c (revision 3d590af8)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * TI LP8501 9 channel LED Driver
4  *
5  * Copyright (C) 2013 Texas Instruments
6  *
7  * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
8  */
9 
10 #include <linux/delay.h>
11 #include <linux/firmware.h>
12 #include <linux/i2c.h>
13 #include <linux/init.h>
14 #include <linux/leds.h>
15 #include <linux/module.h>
16 #include <linux/mutex.h>
17 #include <linux/of.h>
18 #include <linux/platform_data/leds-lp55xx.h>
19 #include <linux/slab.h>
20 
21 #include "leds-lp55xx-common.h"
22 
23 #define LP8501_PROGRAM_LENGTH		32
24 #define LP8501_MAX_LEDS			9
25 
26 /* Registers */
27 #define LP8501_REG_ENABLE		0x00
28 #define LP8501_ENABLE			BIT(6)
29 #define LP8501_EXEC_M			0x3F
30 #define LP8501_EXEC_ENG1_M		0x30
31 #define LP8501_EXEC_ENG2_M		0x0C
32 #define LP8501_EXEC_ENG3_M		0x03
33 #define LP8501_RUN_ENG1			0x20
34 #define LP8501_RUN_ENG2			0x08
35 #define LP8501_RUN_ENG3			0x02
36 
37 #define LP8501_REG_OP_MODE		0x01
38 #define LP8501_MODE_ENG1_M		0x30
39 #define LP8501_MODE_ENG2_M		0x0C
40 #define LP8501_MODE_ENG3_M		0x03
41 #define LP8501_LOAD_ENG1		0x10
42 #define LP8501_LOAD_ENG2		0x04
43 #define LP8501_LOAD_ENG3		0x01
44 
45 #define LP8501_REG_PWR_CONFIG		0x05
46 #define LP8501_PWR_CONFIG_M		0x03
47 
48 #define LP8501_REG_LED_PWM_BASE		0x16
49 
50 #define LP8501_REG_LED_CURRENT_BASE	0x26
51 
52 #define LP8501_REG_CONFIG		0x36
53 #define LP8501_PWM_PSAVE		BIT(7)
54 #define LP8501_AUTO_INC			BIT(6)
55 #define LP8501_PWR_SAVE			BIT(5)
56 #define LP8501_CP_MODE_MASK		0x18
57 #define LP8501_CP_MODE_SHIFT		3
58 #define LP8501_INT_CLK			BIT(0)
59 #define LP8501_DEFAULT_CFG (LP8501_PWM_PSAVE | LP8501_AUTO_INC | LP8501_PWR_SAVE)
60 
61 #define LP8501_REG_RESET		0x3D
62 #define LP8501_RESET			0xFF
63 
64 #define LP8501_REG_PROG_PAGE_SEL	0x4F
65 #define LP8501_PAGE_ENG1		0
66 #define LP8501_PAGE_ENG2		1
67 #define LP8501_PAGE_ENG3		2
68 
69 #define LP8501_REG_PROG_MEM		0x50
70 
71 #define LP8501_ENG1_IS_LOADING(mode)	\
72 	((mode & LP8501_MODE_ENG1_M) == LP8501_LOAD_ENG1)
73 #define LP8501_ENG2_IS_LOADING(mode)	\
74 	((mode & LP8501_MODE_ENG2_M) == LP8501_LOAD_ENG2)
75 #define LP8501_ENG3_IS_LOADING(mode)	\
76 	((mode & LP8501_MODE_ENG3_M) == LP8501_LOAD_ENG3)
77 
lp8501_wait_opmode_done(void)78 static inline void lp8501_wait_opmode_done(void)
79 {
80 	usleep_range(1000, 2000);
81 }
82 
lp8501_set_led_current(struct lp55xx_led * led,u8 led_current)83 static void lp8501_set_led_current(struct lp55xx_led *led, u8 led_current)
84 {
85 	led->led_current = led_current;
86 	lp55xx_write(led->chip, LP8501_REG_LED_CURRENT_BASE + led->chan_nr,
87 		led_current);
88 }
89 
lp8501_post_init_device(struct lp55xx_chip * chip)90 static int lp8501_post_init_device(struct lp55xx_chip *chip)
91 {
92 	int ret;
93 	u8 val = LP8501_DEFAULT_CFG;
94 
95 	ret = lp55xx_write(chip, LP8501_REG_ENABLE, LP8501_ENABLE);
96 	if (ret)
97 		return ret;
98 
99 	/* Chip startup time is 500 us, 1 - 2 ms gives some margin */
100 	usleep_range(1000, 2000);
101 
102 	if (chip->pdata->clock_mode != LP55XX_CLOCK_EXT)
103 		val |= LP8501_INT_CLK;
104 
105 	val |= (chip->pdata->charge_pump_mode << LP8501_CP_MODE_SHIFT) & LP8501_CP_MODE_MASK;
106 
107 	ret = lp55xx_write(chip, LP8501_REG_CONFIG, val);
108 	if (ret)
109 		return ret;
110 
111 	/* Power selection for each output */
112 	return lp55xx_update_bits(chip, LP8501_REG_PWR_CONFIG,
113 				LP8501_PWR_CONFIG_M, chip->pdata->pwr_sel);
114 }
115 
lp8501_load_engine(struct lp55xx_chip * chip)116 static void lp8501_load_engine(struct lp55xx_chip *chip)
117 {
118 	enum lp55xx_engine_index idx = chip->engine_idx;
119 	static const u8 mask[] = {
120 		[LP55XX_ENGINE_1] = LP8501_MODE_ENG1_M,
121 		[LP55XX_ENGINE_2] = LP8501_MODE_ENG2_M,
122 		[LP55XX_ENGINE_3] = LP8501_MODE_ENG3_M,
123 	};
124 
125 	static const u8 val[] = {
126 		[LP55XX_ENGINE_1] = LP8501_LOAD_ENG1,
127 		[LP55XX_ENGINE_2] = LP8501_LOAD_ENG2,
128 		[LP55XX_ENGINE_3] = LP8501_LOAD_ENG3,
129 	};
130 
131 	static const u8 page_sel[] = {
132 		[LP55XX_ENGINE_1] = LP8501_PAGE_ENG1,
133 		[LP55XX_ENGINE_2] = LP8501_PAGE_ENG2,
134 		[LP55XX_ENGINE_3] = LP8501_PAGE_ENG3,
135 	};
136 
137 	lp55xx_update_bits(chip, LP8501_REG_OP_MODE, mask[idx], val[idx]);
138 
139 	lp8501_wait_opmode_done();
140 
141 	lp55xx_write(chip, LP8501_REG_PROG_PAGE_SEL, page_sel[idx]);
142 }
143 
lp8501_stop_engine(struct lp55xx_chip * chip)144 static void lp8501_stop_engine(struct lp55xx_chip *chip)
145 {
146 	lp55xx_write(chip, LP8501_REG_OP_MODE, 0);
147 	lp8501_wait_opmode_done();
148 }
149 
lp8501_turn_off_channels(struct lp55xx_chip * chip)150 static void lp8501_turn_off_channels(struct lp55xx_chip *chip)
151 {
152 	int i;
153 
154 	for (i = 0; i < LP8501_MAX_LEDS; i++)
155 		lp55xx_write(chip, LP8501_REG_LED_PWM_BASE + i, 0);
156 }
157 
lp8501_run_engine(struct lp55xx_chip * chip,bool start)158 static void lp8501_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 		lp8501_stop_engine(chip);
167 		lp8501_turn_off_channels(chip);
168 		return;
169 	}
170 
171 	/*
172 	 * To run the engine,
173 	 * operation mode and enable register should updated at the same time
174 	 */
175 
176 	ret = lp55xx_read(chip, LP8501_REG_OP_MODE, &mode);
177 	if (ret)
178 		return;
179 
180 	ret = lp55xx_read(chip, LP8501_REG_ENABLE, &exec);
181 	if (ret)
182 		return;
183 
184 	/* change operation mode to RUN only when each engine is loading */
185 	if (LP8501_ENG1_IS_LOADING(mode)) {
186 		mode = (mode & ~LP8501_MODE_ENG1_M) | LP8501_RUN_ENG1;
187 		exec = (exec & ~LP8501_EXEC_ENG1_M) | LP8501_RUN_ENG1;
188 	}
189 
190 	if (LP8501_ENG2_IS_LOADING(mode)) {
191 		mode = (mode & ~LP8501_MODE_ENG2_M) | LP8501_RUN_ENG2;
192 		exec = (exec & ~LP8501_EXEC_ENG2_M) | LP8501_RUN_ENG2;
193 	}
194 
195 	if (LP8501_ENG3_IS_LOADING(mode)) {
196 		mode = (mode & ~LP8501_MODE_ENG3_M) | LP8501_RUN_ENG3;
197 		exec = (exec & ~LP8501_EXEC_ENG3_M) | LP8501_RUN_ENG3;
198 	}
199 
200 	lp55xx_write(chip, LP8501_REG_OP_MODE, mode);
201 	lp8501_wait_opmode_done();
202 
203 	lp55xx_update_bits(chip, LP8501_REG_ENABLE, LP8501_EXEC_M, exec);
204 }
205 
lp8501_update_program_memory(struct lp55xx_chip * chip,const u8 * data,size_t size)206 static int lp8501_update_program_memory(struct lp55xx_chip *chip,
207 					const u8 *data, size_t size)
208 {
209 	u8 pattern[LP8501_PROGRAM_LENGTH] = {0};
210 	unsigned cmd;
211 	char c[3];
212 	int update_size;
213 	int nrchars;
214 	int offset = 0;
215 	int ret;
216 	int i;
217 
218 	/* clear program memory before updating */
219 	for (i = 0; i < LP8501_PROGRAM_LENGTH; i++)
220 		lp55xx_write(chip, LP8501_REG_PROG_MEM + i, 0);
221 
222 	i = 0;
223 	while ((offset < size - 1) && (i < LP8501_PROGRAM_LENGTH)) {
224 		/* separate sscanfs because length is working only for %s */
225 		ret = sscanf(data + offset, "%2s%n ", c, &nrchars);
226 		if (ret != 1)
227 			goto err;
228 
229 		ret = sscanf(c, "%2x", &cmd);
230 		if (ret != 1)
231 			goto err;
232 
233 		pattern[i] = (u8)cmd;
234 		offset += nrchars;
235 		i++;
236 	}
237 
238 	/* Each instruction is 16bit long. Check that length is even */
239 	if (i % 2)
240 		goto err;
241 
242 	update_size = i;
243 	for (i = 0; i < update_size; i++)
244 		lp55xx_write(chip, LP8501_REG_PROG_MEM + i, pattern[i]);
245 
246 	return 0;
247 
248 err:
249 	dev_err(&chip->cl->dev, "wrong pattern format\n");
250 	return -EINVAL;
251 }
252 
lp8501_firmware_loaded(struct lp55xx_chip * chip)253 static void lp8501_firmware_loaded(struct lp55xx_chip *chip)
254 {
255 	const struct firmware *fw = chip->fw;
256 
257 	if (fw->size > LP8501_PROGRAM_LENGTH) {
258 		dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
259 			fw->size);
260 		return;
261 	}
262 
263 	/*
264 	 * Program memory sequence
265 	 *  1) set engine mode to "LOAD"
266 	 *  2) write firmware data into program memory
267 	 */
268 
269 	lp8501_load_engine(chip);
270 	lp8501_update_program_memory(chip, fw->data, fw->size);
271 }
272 
lp8501_led_brightness(struct lp55xx_led * led)273 static int lp8501_led_brightness(struct lp55xx_led *led)
274 {
275 	struct lp55xx_chip *chip = led->chip;
276 	int ret;
277 
278 	mutex_lock(&chip->lock);
279 	ret = lp55xx_write(chip, LP8501_REG_LED_PWM_BASE + led->chan_nr,
280 		     led->brightness);
281 	mutex_unlock(&chip->lock);
282 
283 	return ret;
284 }
285 
286 /* Chip specific configurations */
287 static struct lp55xx_device_config lp8501_cfg = {
288 	.reset = {
289 		.addr = LP8501_REG_RESET,
290 		.val  = LP8501_RESET,
291 	},
292 	.enable = {
293 		.addr = LP8501_REG_ENABLE,
294 		.val  = LP8501_ENABLE,
295 	},
296 	.max_channel  = LP8501_MAX_LEDS,
297 	.post_init_device   = lp8501_post_init_device,
298 	.brightness_fn      = lp8501_led_brightness,
299 	.set_led_current    = lp8501_set_led_current,
300 	.firmware_cb        = lp8501_firmware_loaded,
301 	.run_engine         = lp8501_run_engine,
302 };
303 
lp8501_probe(struct i2c_client * client)304 static int lp8501_probe(struct i2c_client *client)
305 {
306 	const struct i2c_device_id *id = i2c_client_get_device_id(client);
307 	int ret;
308 	struct lp55xx_chip *chip;
309 	struct lp55xx_led *led;
310 	struct lp55xx_platform_data *pdata = dev_get_platdata(&client->dev);
311 	struct device_node *np = dev_of_node(&client->dev);
312 
313 	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
314 	if (!chip)
315 		return -ENOMEM;
316 
317 	chip->cfg = &lp8501_cfg;
318 
319 	if (!pdata) {
320 		if (np) {
321 			pdata = lp55xx_of_populate_pdata(&client->dev, np,
322 							 chip);
323 			if (IS_ERR(pdata))
324 				return PTR_ERR(pdata);
325 		} else {
326 			dev_err(&client->dev, "no platform data\n");
327 			return -EINVAL;
328 		}
329 	}
330 
331 	led = devm_kcalloc(&client->dev,
332 			pdata->num_channels, sizeof(*led), GFP_KERNEL);
333 	if (!led)
334 		return -ENOMEM;
335 
336 	chip->cl = client;
337 	chip->pdata = pdata;
338 
339 	mutex_init(&chip->lock);
340 
341 	i2c_set_clientdata(client, led);
342 
343 	ret = lp55xx_init_device(chip);
344 	if (ret)
345 		goto err_init;
346 
347 	dev_info(&client->dev, "%s Programmable led chip found\n", id->name);
348 
349 	ret = lp55xx_register_leds(led, chip);
350 	if (ret)
351 		goto err_out;
352 
353 	ret = lp55xx_register_sysfs(chip);
354 	if (ret) {
355 		dev_err(&client->dev, "registering sysfs failed\n");
356 		goto err_out;
357 	}
358 
359 	return 0;
360 
361 err_out:
362 	lp55xx_deinit_device(chip);
363 err_init:
364 	return ret;
365 }
366 
lp8501_remove(struct i2c_client * client)367 static void lp8501_remove(struct i2c_client *client)
368 {
369 	struct lp55xx_led *led = i2c_get_clientdata(client);
370 	struct lp55xx_chip *chip = led->chip;
371 
372 	lp8501_stop_engine(chip);
373 	lp55xx_unregister_sysfs(chip);
374 	lp55xx_deinit_device(chip);
375 }
376 
377 static const struct i2c_device_id lp8501_id[] = {
378 	{ "lp8501",  0 },
379 	{ }
380 };
381 MODULE_DEVICE_TABLE(i2c, lp8501_id);
382 
383 static const struct of_device_id of_lp8501_leds_match[] = {
384 	{ .compatible = "ti,lp8501", },
385 	{},
386 };
387 
388 MODULE_DEVICE_TABLE(of, of_lp8501_leds_match);
389 
390 static struct i2c_driver lp8501_driver = {
391 	.driver = {
392 		.name	= "lp8501",
393 		.of_match_table = of_lp8501_leds_match,
394 	},
395 	.probe		= lp8501_probe,
396 	.remove		= lp8501_remove,
397 	.id_table	= lp8501_id,
398 };
399 
400 module_i2c_driver(lp8501_driver);
401 
402 MODULE_DESCRIPTION("Texas Instruments LP8501 LED driver");
403 MODULE_AUTHOR("Milo Kim");
404 MODULE_LICENSE("GPL");
405