drivers/leds/leds-lp8501.c

   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/platform_data/leds-lp55xx.h>
  22 #include <linux/slab.h>
  23
  24 #include "leds-lp55xx-common.h"
  25
  26 #define LP8501_PROGRAM_LENGTH           32
  27 #define LP8501_MAX_LEDS                 9
  28
  29 /* Registers */
  30 #define LP8501_REG_ENABLE               0x00
  31 #define LP8501_ENABLE                   BIT(6)
  32 #define LP8501_EXEC_M                   0x3F
  33 #define LP8501_EXEC_ENG1_M              0x30
  34 #define LP8501_EXEC_ENG2_M              0x0C
  35 #define LP8501_EXEC_ENG3_M              0x03
  36 #define LP8501_RUN_ENG1                 0x20
  37 #define LP8501_RUN_ENG2                 0x08
  38 #define LP8501_RUN_ENG3                 0x02
  39
  40 #define LP8501_REG_OP_MODE              0x01
  41 #define LP8501_MODE_ENG1_M              0x30
  42 #define LP8501_MODE_ENG2_M              0x0C
  43 #define LP8501_MODE_ENG3_M              0x03
  44 #define LP8501_LOAD_ENG1                0x10
  45 #define LP8501_LOAD_ENG2                0x04
  46 #define LP8501_LOAD_ENG3                0x01
  47
  48 #define LP8501_REG_PWR_CONFIG           0x05
  49 #define LP8501_PWR_CONFIG_M             0x03
  50
  51 #define LP8501_REG_LED_PWM_BASE         0x16
  52
  53 #define LP8501_REG_LED_CURRENT_BASE     0x26
  54
  55 #define LP8501_REG_CONFIG               0x36
  56 #define LP8501_PWM_PSAVE                BIT(7)
  57 #define LP8501_AUTO_INC                 BIT(6)
  58 #define LP8501_PWR_SAVE                 BIT(5)
  59 #define LP8501_CP_AUTO                  0x18
  60 #define LP8501_INT_CLK                  BIT(0)
  61 #define LP8501_DEFAULT_CFG      \
  62         (LP8501_PWM_PSAVE | LP8501_AUTO_INC | LP8501_PWR_SAVE | LP8501_CP_AUTO)
  63
  64 #define LP8501_REG_RESET                0x3D
  65 #define LP8501_RESET                    0xFF
  66
  67 #define LP8501_REG_PROG_PAGE_SEL        0x4F
  68 #define LP8501_PAGE_ENG1                0
  69 #define LP8501_PAGE_ENG2                1
  70 #define LP8501_PAGE_ENG3                2
  71
  72 #define LP8501_REG_PROG_MEM             0x50
  73
  74 #define LP8501_ENG1_IS_LOADING(mode)    \
  75         ((mode & LP8501_MODE_ENG1_M) == LP8501_LOAD_ENG1)
  76 #define LP8501_ENG2_IS_LOADING(mode)    \
  77         ((mode & LP8501_MODE_ENG2_M) == LP8501_LOAD_ENG2)
  78 #define LP8501_ENG3_IS_LOADING(mode)    \
  79         ((mode & LP8501_MODE_ENG3_M) == LP8501_LOAD_ENG3)
  80
  81 static inline void lp8501_wait_opmode_done(void)
  82 {
  83         usleep_range(1000, 2000);
  84 }
  85
  86 static void lp8501_set_led_current(struct lp55xx_led *led, u8 led_current)
  87 {
  88         led->led_current = led_current;
  89         lp55xx_write(led->chip, LP8501_REG_LED_CURRENT_BASE + led->chan_nr,
  90                 led_current);
  91 }
  92
  93 static int lp8501_post_init_device(struct lp55xx_chip *chip)
  94 {
  95         int ret;
  96         u8 val = LP8501_DEFAULT_CFG;
  97
  98         ret = lp55xx_write(chip, LP8501_REG_ENABLE, LP8501_ENABLE);
  99         if (ret)
 100                 return ret;
 101
 102         /* Chip startup time is 500 us, 1 - 2 ms gives some margin */
 103         usleep_range(1000, 2000);
 104
 105         if (chip->pdata->clock_mode != LP55XX_CLOCK_EXT)
 106                 val |= LP8501_INT_CLK;
 107
 108         ret = lp55xx_write(chip, LP8501_REG_CONFIG, val);
 109         if (ret)
 110                 return ret;
 111
 112         /* Power selection for each output */
 113         return lp55xx_update_bits(chip, LP8501_REG_PWR_CONFIG,
 114                                 LP8501_PWR_CONFIG_M, chip->pdata->pwr_sel);
 115 }
 116
 117 static void lp8501_load_engine(struct lp55xx_chip *chip)
 118 {
 119         enum lp55xx_engine_index idx = chip->engine_idx;
 120         u8 mask[] = {
 121                 [LP55XX_ENGINE_1] = LP8501_MODE_ENG1_M,
 122                 [LP55XX_ENGINE_2] = LP8501_MODE_ENG2_M,
 123                 [LP55XX_ENGINE_3] = LP8501_MODE_ENG3_M,
 124         };
 125
 126         u8 val[] = {
 127                 [LP55XX_ENGINE_1] = LP8501_LOAD_ENG1,
 128                 [LP55XX_ENGINE_2] = LP8501_LOAD_ENG2,
 129                 [LP55XX_ENGINE_3] = LP8501_LOAD_ENG3,
 130         };
 131
 132         u8 page_sel[] = {
 133                 [LP55XX_ENGINE_1] = LP8501_PAGE_ENG1,
 134                 [LP55XX_ENGINE_2] = LP8501_PAGE_ENG2,
 135                 [LP55XX_ENGINE_3] = LP8501_PAGE_ENG3,
 136         };
 137
 138         lp55xx_update_bits(chip, LP8501_REG_OP_MODE, mask[idx], val[idx]);
 139
 140         lp8501_wait_opmode_done();
 141
 142         lp55xx_write(chip, LP8501_REG_PROG_PAGE_SEL, page_sel[idx]);
 143 }
 144
 145 static void lp8501_stop_engine(struct lp55xx_chip *chip)
 146 {
 147         lp55xx_write(chip, LP8501_REG_OP_MODE, 0);
 148         lp8501_wait_opmode_done();
 149 }
 150
 151 static void lp8501_turn_off_channels(struct lp55xx_chip *chip)
 152 {
 153         int i;
 154
 155         for (i = 0; i < LP8501_MAX_LEDS; i++)
 156                 lp55xx_write(chip, LP8501_REG_LED_PWM_BASE + i, 0);
 157 }
 158
 159 static void lp8501_run_engine(struct lp55xx_chip *chip, bool start)
 160 {
 161         int ret;
 162         u8 mode;
 163         u8 exec;
 164
 165         /* stop engine */
 166         if (!start) {
 167                 lp8501_stop_engine(chip);
 168                 lp8501_turn_off_channels(chip);
 169                 return;
 170         }
 171
 172         /*
 173          * To run the engine,
 174          * operation mode and enable register should updated at the same time
 175          */
 176
 177         ret = lp55xx_read(chip, LP8501_REG_OP_MODE, &mode);
 178         if (ret)
 179                 return;
 180
 181         ret = lp55xx_read(chip, LP8501_REG_ENABLE, &exec);
 182         if (ret)
 183                 return;
 184
 185         /* change operation mode to RUN only when each engine is loading */
 186         if (LP8501_ENG1_IS_LOADING(mode)) {
 187                 mode = (mode & ~LP8501_MODE_ENG1_M) | LP8501_RUN_ENG1;
 188                 exec = (exec & ~LP8501_EXEC_ENG1_M) | LP8501_RUN_ENG1;
 189         }
 190
 191         if (LP8501_ENG2_IS_LOADING(mode)) {
 192                 mode = (mode & ~LP8501_MODE_ENG2_M) | LP8501_RUN_ENG2;
 193                 exec = (exec & ~LP8501_EXEC_ENG2_M) | LP8501_RUN_ENG2;
 194         }
 195
 196         if (LP8501_ENG3_IS_LOADING(mode)) {
 197                 mode = (mode & ~LP8501_MODE_ENG3_M) | LP8501_RUN_ENG3;
 198                 exec = (exec & ~LP8501_EXEC_ENG3_M) | LP8501_RUN_ENG3;
 199         }
 200
 201         lp55xx_write(chip, LP8501_REG_OP_MODE, mode);
 202         lp8501_wait_opmode_done();
 203
 204         lp55xx_update_bits(chip, LP8501_REG_ENABLE, LP8501_EXEC_M, exec);
 205 }
 206
 207 static int lp8501_update_program_memory(struct lp55xx_chip *chip,
 208                                         const u8 *data, size_t size)
 209 {
 210         u8 pattern[LP8501_PROGRAM_LENGTH] = {0};
 211         unsigned cmd;
 212         char c[3];
 213         int update_size;
 214         int nrchars;
 215         int offset = 0;
 216         int ret;
 217         int i;
 218
 219         /* clear program memory before updating */
 220         for (i = 0; i < LP8501_PROGRAM_LENGTH; i++)
 221                 lp55xx_write(chip, LP8501_REG_PROG_MEM + i, 0);
 222
 223         i = 0;
 224         while ((offset < size - 1) && (i < LP8501_PROGRAM_LENGTH)) {
 225                 /* separate sscanfs because length is working only for %s */
 226                 ret = sscanf(data + offset, "%2s%n ", c, &nrchars);
 227                 if (ret != 1)
 228                         goto err;
 229
 230                 ret = sscanf(c, "%2x", &cmd);
 231                 if (ret != 1)
 232                         goto err;
 233
 234                 pattern[i] = (u8)cmd;
 235                 offset += nrchars;
 236                 i++;
 237         }
 238
 239         /* Each instruction is 16bit long. Check that length is even */
 240         if (i % 2)
 241                 goto err;
 242
 243         update_size = i;
 244         for (i = 0; i < update_size; i++)
 245                 lp55xx_write(chip, LP8501_REG_PROG_MEM + i, pattern[i]);
 246
 247         return 0;
 248
 249 err:
 250         dev_err(&chip->cl->dev, "wrong pattern format\n");
 251         return -EINVAL;
 252 }
 253
 254 static void lp8501_firmware_loaded(struct lp55xx_chip *chip)
 255 {
 256         const struct firmware *fw = chip->fw;
 257
 258         if (fw->size > LP8501_PROGRAM_LENGTH) {
 259                 dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
 260                         fw->size);
 261                 return;
 262         }
 263
 264         /*
 265          * Program momery sequence
 266          *  1) set engine mode to "LOAD"
 267          *  2) write firmware data into program memory
 268          */
 269
 270         lp8501_load_engine(chip);
 271         lp8501_update_program_memory(chip, fw->data, fw->size);
 272 }
 273
 274 static void lp8501_led_brightness_work(struct work_struct *work)
 275 {
 276         struct lp55xx_led *led = container_of(work, struct lp55xx_led,
 277                                               brightness_work);
 278         struct lp55xx_chip *chip = led->chip;
 279
 280         mutex_lock(&chip->lock);
 281         lp55xx_write(chip, LP8501_REG_LED_PWM_BASE + led->chan_nr,
 282                      led->brightness);
 283         mutex_unlock(&chip->lock);
 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_work_fn = lp8501_led_brightness_work,
 299         .set_led_current    = lp8501_set_led_current,
 300         .firmware_cb        = lp8501_firmware_loaded,
 301         .run_engine         = lp8501_run_engine,
 302 };
 303
 304 static int lp8501_probe(struct i2c_client *client,
 305                         const struct i2c_device_id *id)
 306 {
 307         int ret;
 308         struct lp55xx_chip *chip;
 309         struct lp55xx_led *led;
 310         struct lp55xx_platform_data *pdata;
 311         struct device_node *np = client->dev.of_node;
 312
 313         if (!dev_get_platdata(&client->dev)) {
 314                 if (np) {
 315                         ret = lp55xx_of_populate_pdata(&client->dev, np);
 316                         if (ret < 0)
 317                                 return ret;
 318                 } else {
 319                         dev_err(&client->dev, "no platform data\n");
 320                         return -EINVAL;
 321                 }
 322         }
 323         pdata = dev_get_platdata(&client->dev);
 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
 360 err_register_sysfs:
 361         lp55xx_unregister_leds(led, chip);
 362 err_register_leds:
 363         lp55xx_deinit_device(chip);
 364 err_init:
 365         return ret;
 366 }
 367
 368 static 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
 381 static const struct i2c_device_id lp8501_id[] = {
 382         { "lp8501",  0 },
 383         { }
 384 };
 385 MODULE_DEVICE_TABLE(i2c, lp8501_id);
 386
 387 #ifdef CONFIG_OF
 388 static const struct of_device_id of_lp8501_leds_match[] = {
 389         { .compatible = "ti,lp8501", },
 390         {},
 391 };
 392
 393 MODULE_DEVICE_TABLE(of, of_lp8501_leds_match);
 394 #endif
 395
 396 static 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
 406 module_i2c_driver(lp8501_driver);
 407
 408 MODULE_DESCRIPTION("Texas Instruments LP8501 LED drvier");
 409 MODULE_AUTHOR("Milo Kim");
 410 MODULE_LICENSE("GPL");