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
78static inline void lp8501_wait_opmode_done(void)
79{
80 usleep_range(min: 1000, max: 2000);
81}
82
83static void lp8501_set_led_current(struct lp55xx_led *led, u8 led_current)
84{
85 led->led_current = led_current;
86 lp55xx_write(chip: led->chip, LP8501_REG_LED_CURRENT_BASE + led->chan_nr,
87 val: led_current);
88}
89
90static 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(min: 1000, max: 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, val: chip->pdata->pwr_sel);
114}
115
116static 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: mask[idx], val: val[idx]);
138
139 lp8501_wait_opmode_done();
140
141 lp55xx_write(chip, LP8501_REG_PROG_PAGE_SEL, val: page_sel[idx]);
142}
143
144static void lp8501_stop_engine(struct lp55xx_chip *chip)
145{
146 lp55xx_write(chip, LP8501_REG_OP_MODE, val: 0);
147 lp8501_wait_opmode_done();
148}
149
150static 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, val: 0);
156}
157
158static 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, val: &mode);
177 if (ret)
178 return;
179
180 ret = lp55xx_read(chip, LP8501_REG_ENABLE, val: &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, val: mode);
201 lp8501_wait_opmode_done();
202
203 lp55xx_update_bits(chip, LP8501_REG_ENABLE, LP8501_EXEC_M, val: exec);
204}
205
206static 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, val: 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, val: pattern[i]);
245
246 return 0;
247
248err:
249 dev_err(&chip->cl->dev, "wrong pattern format\n");
250 return -EINVAL;
251}
252
253static 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, data: fw->data, size: fw->size);
271}
272
273static 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 val: led->brightness);
281 mutex_unlock(lock: &chip->lock);
282
283 return ret;
284}
285
286/* Chip specific configurations */
287static 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
304static 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(dev: &client->dev);
311 struct device_node *np = dev_of_node(dev: &client->dev);
312
313 chip = devm_kzalloc(dev: &client->dev, size: 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(dev: &client->dev, np,
322 chip);
323 if (IS_ERR(ptr: pdata))
324 return PTR_ERR(ptr: pdata);
325 } else {
326 dev_err(&client->dev, "no platform data\n");
327 return -EINVAL;
328 }
329 }
330
331 led = devm_kcalloc(dev: &client->dev,
332 n: pdata->num_channels, size: 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, data: 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
361err_out:
362 lp55xx_deinit_device(chip);
363err_init:
364 return ret;
365}
366
367static 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
377static const struct i2c_device_id lp8501_id[] = {
378 { "lp8501", 0 },
379 { }
380};
381MODULE_DEVICE_TABLE(i2c, lp8501_id);
382
383static const struct of_device_id of_lp8501_leds_match[] = {
384 { .compatible = "ti,lp8501", },
385 {},
386};
387
388MODULE_DEVICE_TABLE(of, of_lp8501_leds_match);
389
390static 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
400module_i2c_driver(lp8501_driver);
401
402MODULE_DESCRIPTION("Texas Instruments LP8501 LED driver");
403MODULE_AUTHOR("Milo Kim");
404MODULE_LICENSE("GPL");
405

source code of linux/drivers/leds/leds-lp8501.c