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 82 static inline void lp8501_wait_opmode_done(void) 83 { 84 usleep_range(1000, 2000); 85 } 86 87 static 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 94 static 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 } 117 118 static 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 } 145 146 static void lp8501_stop_engine(struct lp55xx_chip *chip) 147 { 148 lp55xx_write(chip, LP8501_REG_OP_MODE, 0); 149 lp8501_wait_opmode_done(); 150 } 151 152 static 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 } 159 160 static 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 } 207 208 static 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; 249 250 err: 251 dev_err(&chip->cl->dev, "wrong pattern format\n"); 252 return -EINVAL; 253 } 254 255 static 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 } 274 275 static 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 */ 288 static 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 }; 304 305 static 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; 312 struct device_node *np = client->dev.of_node; 313 314 if (!dev_get_platdata(&client->dev)) { 315 if (np) { 316 ret = lp55xx_of_populate_pdata(&client->dev, np); 317 if (ret < 0) 318 return ret; 319 } else { 320 dev_err(&client->dev, "no platform data\n"); 321 return -EINVAL; 322 } 323 } 324 pdata = dev_get_platdata(&client->dev); 325 326 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL); 327 if (!chip) 328 return -ENOMEM; 329 330 led = devm_kzalloc(&client->dev, 331 sizeof(*led) * pdata->num_channels, GFP_KERNEL); 332 if (!led) 333 return -ENOMEM; 334 335 chip->cl = client; 336 chip->pdata = pdata; 337 chip->cfg = &lp8501_cfg; 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_register_leds; 352 353 ret = lp55xx_register_sysfs(chip); 354 if (ret) { 355 dev_err(&client->dev, "registering sysfs failed\n"); 356 goto err_register_sysfs; 357 } 358 359 return 0; 360 361 err_register_sysfs: 362 lp55xx_unregister_leds(led, chip); 363 err_register_leds: 364 lp55xx_deinit_device(chip); 365 err_init: 366 return ret; 367 } 368 369 static int lp8501_remove(struct i2c_client *client) 370 { 371 struct lp55xx_led *led = i2c_get_clientdata(client); 372 struct lp55xx_chip *chip = led->chip; 373 374 lp8501_stop_engine(chip); 375 lp55xx_unregister_sysfs(chip); 376 lp55xx_unregister_leds(led, chip); 377 lp55xx_deinit_device(chip); 378 379 return 0; 380 } 381 382 static const struct i2c_device_id lp8501_id[] = { 383 { "lp8501", 0 }, 384 { } 385 }; 386 MODULE_DEVICE_TABLE(i2c, lp8501_id); 387 388 #ifdef CONFIG_OF 389 static const struct of_device_id of_lp8501_leds_match[] = { 390 { .compatible = "ti,lp8501", }, 391 {}, 392 }; 393 394 MODULE_DEVICE_TABLE(of, of_lp8501_leds_match); 395 #endif 396 397 static struct i2c_driver lp8501_driver = { 398 .driver = { 399 .name = "lp8501", 400 .of_match_table = of_match_ptr(of_lp8501_leds_match), 401 }, 402 .probe = lp8501_probe, 403 .remove = lp8501_remove, 404 .id_table = lp8501_id, 405 }; 406 407 module_i2c_driver(lp8501_driver); 408 409 MODULE_DESCRIPTION("Texas Instruments LP8501 LED drvier"); 410 MODULE_AUTHOR("Milo Kim"); 411 MODULE_LICENSE("GPL"); 412