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_AUTO 0x18
57 #define LP8501_INT_CLK BIT(0)
58 #define LP8501_DEFAULT_CFG \
59 (LP8501_PWM_PSAVE | LP8501_AUTO_INC | LP8501_PWR_SAVE | LP8501_CP_AUTO)
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 ret = lp55xx_write(chip, LP8501_REG_CONFIG, val);
106 if (ret)
107 return ret;
108
109 /* Power selection for each output */
110 return lp55xx_update_bits(chip, LP8501_REG_PWR_CONFIG,
111 LP8501_PWR_CONFIG_M, chip->pdata->pwr_sel);
112 }
113
lp8501_load_engine(struct lp55xx_chip * chip)114 static void lp8501_load_engine(struct lp55xx_chip *chip)
115 {
116 enum lp55xx_engine_index idx = chip->engine_idx;
117 static const u8 mask[] = {
118 [LP55XX_ENGINE_1] = LP8501_MODE_ENG1_M,
119 [LP55XX_ENGINE_2] = LP8501_MODE_ENG2_M,
120 [LP55XX_ENGINE_3] = LP8501_MODE_ENG3_M,
121 };
122
123 static const u8 val[] = {
124 [LP55XX_ENGINE_1] = LP8501_LOAD_ENG1,
125 [LP55XX_ENGINE_2] = LP8501_LOAD_ENG2,
126 [LP55XX_ENGINE_3] = LP8501_LOAD_ENG3,
127 };
128
129 static const u8 page_sel[] = {
130 [LP55XX_ENGINE_1] = LP8501_PAGE_ENG1,
131 [LP55XX_ENGINE_2] = LP8501_PAGE_ENG2,
132 [LP55XX_ENGINE_3] = LP8501_PAGE_ENG3,
133 };
134
135 lp55xx_update_bits(chip, LP8501_REG_OP_MODE, mask[idx], val[idx]);
136
137 lp8501_wait_opmode_done();
138
139 lp55xx_write(chip, LP8501_REG_PROG_PAGE_SEL, page_sel[idx]);
140 }
141
lp8501_stop_engine(struct lp55xx_chip * chip)142 static void lp8501_stop_engine(struct lp55xx_chip *chip)
143 {
144 lp55xx_write(chip, LP8501_REG_OP_MODE, 0);
145 lp8501_wait_opmode_done();
146 }
147
lp8501_turn_off_channels(struct lp55xx_chip * chip)148 static void lp8501_turn_off_channels(struct lp55xx_chip *chip)
149 {
150 int i;
151
152 for (i = 0; i < LP8501_MAX_LEDS; i++)
153 lp55xx_write(chip, LP8501_REG_LED_PWM_BASE + i, 0);
154 }
155
lp8501_run_engine(struct lp55xx_chip * chip,bool start)156 static void lp8501_run_engine(struct lp55xx_chip *chip, bool start)
157 {
158 int ret;
159 u8 mode;
160 u8 exec;
161
162 /* stop engine */
163 if (!start) {
164 lp8501_stop_engine(chip);
165 lp8501_turn_off_channels(chip);
166 return;
167 }
168
169 /*
170 * To run the engine,
171 * operation mode and enable register should updated at the same time
172 */
173
174 ret = lp55xx_read(chip, LP8501_REG_OP_MODE, &mode);
175 if (ret)
176 return;
177
178 ret = lp55xx_read(chip, LP8501_REG_ENABLE, &exec);
179 if (ret)
180 return;
181
182 /* change operation mode to RUN only when each engine is loading */
183 if (LP8501_ENG1_IS_LOADING(mode)) {
184 mode = (mode & ~LP8501_MODE_ENG1_M) | LP8501_RUN_ENG1;
185 exec = (exec & ~LP8501_EXEC_ENG1_M) | LP8501_RUN_ENG1;
186 }
187
188 if (LP8501_ENG2_IS_LOADING(mode)) {
189 mode = (mode & ~LP8501_MODE_ENG2_M) | LP8501_RUN_ENG2;
190 exec = (exec & ~LP8501_EXEC_ENG2_M) | LP8501_RUN_ENG2;
191 }
192
193 if (LP8501_ENG3_IS_LOADING(mode)) {
194 mode = (mode & ~LP8501_MODE_ENG3_M) | LP8501_RUN_ENG3;
195 exec = (exec & ~LP8501_EXEC_ENG3_M) | LP8501_RUN_ENG3;
196 }
197
198 lp55xx_write(chip, LP8501_REG_OP_MODE, mode);
199 lp8501_wait_opmode_done();
200
201 lp55xx_update_bits(chip, LP8501_REG_ENABLE, LP8501_EXEC_M, exec);
202 }
203
lp8501_update_program_memory(struct lp55xx_chip * chip,const u8 * data,size_t size)204 static int lp8501_update_program_memory(struct lp55xx_chip *chip,
205 const u8 *data, size_t size)
206 {
207 u8 pattern[LP8501_PROGRAM_LENGTH] = {0};
208 unsigned cmd;
209 char c[3];
210 int update_size;
211 int nrchars;
212 int offset = 0;
213 int ret;
214 int i;
215
216 /* clear program memory before updating */
217 for (i = 0; i < LP8501_PROGRAM_LENGTH; i++)
218 lp55xx_write(chip, LP8501_REG_PROG_MEM + i, 0);
219
220 i = 0;
221 while ((offset < size - 1) && (i < LP8501_PROGRAM_LENGTH)) {
222 /* separate sscanfs because length is working only for %s */
223 ret = sscanf(data + offset, "%2s%n ", c, &nrchars);
224 if (ret != 1)
225 goto err;
226
227 ret = sscanf(c, "%2x", &cmd);
228 if (ret != 1)
229 goto err;
230
231 pattern[i] = (u8)cmd;
232 offset += nrchars;
233 i++;
234 }
235
236 /* Each instruction is 16bit long. Check that length is even */
237 if (i % 2)
238 goto err;
239
240 update_size = i;
241 for (i = 0; i < update_size; i++)
242 lp55xx_write(chip, LP8501_REG_PROG_MEM + i, pattern[i]);
243
244 return 0;
245
246 err:
247 dev_err(&chip->cl->dev, "wrong pattern format\n");
248 return -EINVAL;
249 }
250
lp8501_firmware_loaded(struct lp55xx_chip * chip)251 static void lp8501_firmware_loaded(struct lp55xx_chip *chip)
252 {
253 const struct firmware *fw = chip->fw;
254
255 if (fw->size > LP8501_PROGRAM_LENGTH) {
256 dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
257 fw->size);
258 return;
259 }
260
261 /*
262 * Program memory sequence
263 * 1) set engine mode to "LOAD"
264 * 2) write firmware data into program memory
265 */
266
267 lp8501_load_engine(chip);
268 lp8501_update_program_memory(chip, fw->data, fw->size);
269 }
270
lp8501_led_brightness(struct lp55xx_led * led)271 static int lp8501_led_brightness(struct lp55xx_led *led)
272 {
273 struct lp55xx_chip *chip = led->chip;
274 int ret;
275
276 mutex_lock(&chip->lock);
277 ret = lp55xx_write(chip, LP8501_REG_LED_PWM_BASE + led->chan_nr,
278 led->brightness);
279 mutex_unlock(&chip->lock);
280
281 return ret;
282 }
283
284 /* Chip specific configurations */
285 static struct lp55xx_device_config lp8501_cfg = {
286 .reset = {
287 .addr = LP8501_REG_RESET,
288 .val = LP8501_RESET,
289 },
290 .enable = {
291 .addr = LP8501_REG_ENABLE,
292 .val = LP8501_ENABLE,
293 },
294 .max_channel = LP8501_MAX_LEDS,
295 .post_init_device = lp8501_post_init_device,
296 .brightness_fn = lp8501_led_brightness,
297 .set_led_current = lp8501_set_led_current,
298 .firmware_cb = lp8501_firmware_loaded,
299 .run_engine = lp8501_run_engine,
300 };
301
lp8501_probe(struct i2c_client * client,const struct i2c_device_id * id)302 static int lp8501_probe(struct i2c_client *client,
303 const struct i2c_device_id *id)
304 {
305 int ret;
306 struct lp55xx_chip *chip;
307 struct lp55xx_led *led;
308 struct lp55xx_platform_data *pdata = dev_get_platdata(&client->dev);
309 struct device_node *np = dev_of_node(&client->dev);
310
311 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
312 if (!chip)
313 return -ENOMEM;
314
315 chip->cfg = &lp8501_cfg;
316
317 if (!pdata) {
318 if (np) {
319 pdata = lp55xx_of_populate_pdata(&client->dev, np,
320 chip);
321 if (IS_ERR(pdata))
322 return PTR_ERR(pdata);
323 } else {
324 dev_err(&client->dev, "no platform data\n");
325 return -EINVAL;
326 }
327 }
328
329 led = devm_kcalloc(&client->dev,
330 pdata->num_channels, sizeof(*led), GFP_KERNEL);
331 if (!led)
332 return -ENOMEM;
333
334 chip->cl = client;
335 chip->pdata = pdata;
336
337 mutex_init(&chip->lock);
338
339 i2c_set_clientdata(client, led);
340
341 ret = lp55xx_init_device(chip);
342 if (ret)
343 goto err_init;
344
345 dev_info(&client->dev, "%s Programmable led chip found\n", id->name);
346
347 ret = lp55xx_register_leds(led, chip);
348 if (ret)
349 goto err_out;
350
351 ret = lp55xx_register_sysfs(chip);
352 if (ret) {
353 dev_err(&client->dev, "registering sysfs failed\n");
354 goto err_out;
355 }
356
357 return 0;
358
359 err_out:
360 lp55xx_deinit_device(chip);
361 err_init:
362 return ret;
363 }
364
lp8501_remove(struct i2c_client * client)365 static void lp8501_remove(struct i2c_client *client)
366 {
367 struct lp55xx_led *led = i2c_get_clientdata(client);
368 struct lp55xx_chip *chip = led->chip;
369
370 lp8501_stop_engine(chip);
371 lp55xx_unregister_sysfs(chip);
372 lp55xx_deinit_device(chip);
373 }
374
375 static const struct i2c_device_id lp8501_id[] = {
376 { "lp8501", 0 },
377 { }
378 };
379 MODULE_DEVICE_TABLE(i2c, lp8501_id);
380
381 #ifdef CONFIG_OF
382 static const struct of_device_id of_lp8501_leds_match[] = {
383 { .compatible = "ti,lp8501", },
384 {},
385 };
386
387 MODULE_DEVICE_TABLE(of, of_lp8501_leds_match);
388 #endif
389
390 static struct i2c_driver lp8501_driver = {
391 .driver = {
392 .name = "lp8501",
393 .of_match_table = of_match_ptr(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