kernel/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/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 driver");
 410 MODULE_AUTHOR("Milo Kim");
 411 MODULE_LICENSE("GPL");