drivers/leds/leds-lp8501.c

   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
  78 static inline void lp8501_wait_opmode_done(void)
  79 {
  80         usleep_range(1000, 2000);
  81 }
  82
  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
  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
 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
 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
 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
 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
 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
 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
 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
 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
 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");