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_MODE_MASK             0x18
  57 #define LP8501_CP_MODE_SHIFT            3
  58 #define LP8501_INT_CLK                  BIT(0)
  59 #define LP8501_DEFAULT_CFG (LP8501_PWM_PSAVE | LP8501_AUTO_INC | LP8501_PWR_SAVE)
  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         val |= (chip->pdata->charge_pump_mode << LP8501_CP_MODE_SHIFT) & LP8501_CP_MODE_MASK;
 106
 107         ret = lp55xx_write(chip, LP8501_REG_CONFIG, val);
 108         if (ret)
 109                 return ret;
 110
 111         /* Power selection for each output */
 112         return lp55xx_update_bits(chip, LP8501_REG_PWR_CONFIG,
 113                                 LP8501_PWR_CONFIG_M, chip->pdata->pwr_sel);
 114 }
 115
 116 static void lp8501_load_engine(struct lp55xx_chip *chip)
 117 {
 118         enum lp55xx_engine_index idx = chip->engine_idx;
 119         static const u8 mask[] = {
 120                 [LP55XX_ENGINE_1] = LP8501_MODE_ENG1_M,
 121                 [LP55XX_ENGINE_2] = LP8501_MODE_ENG2_M,
 122                 [LP55XX_ENGINE_3] = LP8501_MODE_ENG3_M,
 123         };
 124
 125         static const u8 val[] = {
 126                 [LP55XX_ENGINE_1] = LP8501_LOAD_ENG1,
 127                 [LP55XX_ENGINE_2] = LP8501_LOAD_ENG2,
 128                 [LP55XX_ENGINE_3] = LP8501_LOAD_ENG3,
 129         };
 130
 131         static const u8 page_sel[] = {
 132                 [LP55XX_ENGINE_1] = LP8501_PAGE_ENG1,
 133                 [LP55XX_ENGINE_2] = LP8501_PAGE_ENG2,
 134                 [LP55XX_ENGINE_3] = LP8501_PAGE_ENG3,
 135         };
 136
 137         lp55xx_update_bits(chip, LP8501_REG_OP_MODE, mask[idx], val[idx]);
 138
 139         lp8501_wait_opmode_done();
 140
 141         lp55xx_write(chip, LP8501_REG_PROG_PAGE_SEL, page_sel[idx]);
 142 }
 143
 144 static void lp8501_stop_engine(struct lp55xx_chip *chip)
 145 {
 146         lp55xx_write(chip, LP8501_REG_OP_MODE, 0);
 147         lp8501_wait_opmode_done();
 148 }
 149
 150 static void lp8501_turn_off_channels(struct lp55xx_chip *chip)
 151 {
 152         int i;
 153
 154         for (i = 0; i < LP8501_MAX_LEDS; i++)
 155                 lp55xx_write(chip, LP8501_REG_LED_PWM_BASE + i, 0);
 156 }
 157
 158 static void lp8501_run_engine(struct lp55xx_chip *chip, bool start)
 159 {
 160         int ret;
 161         u8 mode;
 162         u8 exec;
 163
 164         /* stop engine */
 165         if (!start) {
 166                 lp8501_stop_engine(chip);
 167                 lp8501_turn_off_channels(chip);
 168                 return;
 169         }
 170
 171         /*
 172          * To run the engine,
 173          * operation mode and enable register should updated at the same time
 174          */
 175
 176         ret = lp55xx_read(chip, LP8501_REG_OP_MODE, &mode);
 177         if (ret)
 178                 return;
 179
 180         ret = lp55xx_read(chip, LP8501_REG_ENABLE, &exec);
 181         if (ret)
 182                 return;
 183
 184         /* change operation mode to RUN only when each engine is loading */
 185         if (LP8501_ENG1_IS_LOADING(mode)) {
 186                 mode = (mode & ~LP8501_MODE_ENG1_M) | LP8501_RUN_ENG1;
 187                 exec = (exec & ~LP8501_EXEC_ENG1_M) | LP8501_RUN_ENG1;
 188         }
 189
 190         if (LP8501_ENG2_IS_LOADING(mode)) {
 191                 mode = (mode & ~LP8501_MODE_ENG2_M) | LP8501_RUN_ENG2;
 192                 exec = (exec & ~LP8501_EXEC_ENG2_M) | LP8501_RUN_ENG2;
 193         }
 194
 195         if (LP8501_ENG3_IS_LOADING(mode)) {
 196                 mode = (mode & ~LP8501_MODE_ENG3_M) | LP8501_RUN_ENG3;
 197                 exec = (exec & ~LP8501_EXEC_ENG3_M) | LP8501_RUN_ENG3;
 198         }
 199
 200         lp55xx_write(chip, LP8501_REG_OP_MODE, mode);
 201         lp8501_wait_opmode_done();
 202
 203         lp55xx_update_bits(chip, LP8501_REG_ENABLE, LP8501_EXEC_M, exec);
 204 }
 205
 206 static int lp8501_update_program_memory(struct lp55xx_chip *chip,
 207                                         const u8 *data, size_t size)
 208 {
 209         u8 pattern[LP8501_PROGRAM_LENGTH] = {0};
 210         unsigned cmd;
 211         char c[3];
 212         int update_size;
 213         int nrchars;
 214         int offset = 0;
 215         int ret;
 216         int i;
 217
 218         /* clear program memory before updating */
 219         for (i = 0; i < LP8501_PROGRAM_LENGTH; i++)
 220                 lp55xx_write(chip, LP8501_REG_PROG_MEM + i, 0);
 221
 222         i = 0;
 223         while ((offset < size - 1) && (i < LP8501_PROGRAM_LENGTH)) {
 224                 /* separate sscanfs because length is working only for %s */
 225                 ret = sscanf(data + offset, "%2s%n ", c, &nrchars);
 226                 if (ret != 1)
 227                         goto err;
 228
 229                 ret = sscanf(c, "%2x", &cmd);
 230                 if (ret != 1)
 231                         goto err;
 232
 233                 pattern[i] = (u8)cmd;
 234                 offset += nrchars;
 235                 i++;
 236         }
 237
 238         /* Each instruction is 16bit long. Check that length is even */
 239         if (i % 2)
 240                 goto err;
 241
 242         update_size = i;
 243         for (i = 0; i < update_size; i++)
 244                 lp55xx_write(chip, LP8501_REG_PROG_MEM + i, pattern[i]);
 245
 246         return 0;
 247
 248 err:
 249         dev_err(&chip->cl->dev, "wrong pattern format\n");
 250         return -EINVAL;
 251 }
 252
 253 static void lp8501_firmware_loaded(struct lp55xx_chip *chip)
 254 {
 255         const struct firmware *fw = chip->fw;
 256
 257         if (fw->size > LP8501_PROGRAM_LENGTH) {
 258                 dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
 259                         fw->size);
 260                 return;
 261         }
 262
 263         /*
 264          * Program memory sequence
 265          *  1) set engine mode to "LOAD"
 266          *  2) write firmware data into program memory
 267          */
 268
 269         lp8501_load_engine(chip);
 270         lp8501_update_program_memory(chip, fw->data, fw->size);
 271 }
 272
 273 static int lp8501_led_brightness(struct lp55xx_led *led)
 274 {
 275         struct lp55xx_chip *chip = led->chip;
 276         int ret;
 277
 278         mutex_lock(&chip->lock);
 279         ret = lp55xx_write(chip, LP8501_REG_LED_PWM_BASE + led->chan_nr,
 280                      led->brightness);
 281         mutex_unlock(&chip->lock);
 282
 283         return ret;
 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_fn      = lp8501_led_brightness,
 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 {
 306         const struct i2c_device_id *id = i2c_client_get_device_id(client);
 307         int ret;
 308         struct lp55xx_chip *chip;
 309         struct lp55xx_led *led;
 310         struct lp55xx_platform_data *pdata = dev_get_platdata(&client->dev);
 311         struct device_node *np = dev_of_node(&client->dev);
 312
 313         chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
 314         if (!chip)
 315                 return -ENOMEM;
 316
 317         chip->cfg = &lp8501_cfg;
 318
 319         if (!pdata) {
 320                 if (np) {
 321                         pdata = lp55xx_of_populate_pdata(&client->dev, np,
 322                                                          chip);
 323                         if (IS_ERR(pdata))
 324                                 return PTR_ERR(pdata);
 325                 } else {
 326                         dev_err(&client->dev, "no platform data\n");
 327                         return -EINVAL;
 328                 }
 329         }
 330
 331         led = devm_kcalloc(&client->dev,
 332                         pdata->num_channels, sizeof(*led), GFP_KERNEL);
 333         if (!led)
 334                 return -ENOMEM;
 335
 336         chip->cl = client;
 337         chip->pdata = pdata;
 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_out;
 352
 353         ret = lp55xx_register_sysfs(chip);
 354         if (ret) {
 355                 dev_err(&client->dev, "registering sysfs failed\n");
 356                 goto err_out;
 357         }
 358
 359         return 0;
 360
 361 err_out:
 362         lp55xx_deinit_device(chip);
 363 err_init:
 364         return ret;
 365 }
 366
 367 static void lp8501_remove(struct i2c_client *client)
 368 {
 369         struct lp55xx_led *led = i2c_get_clientdata(client);
 370         struct lp55xx_chip *chip = led->chip;
 371
 372         lp8501_stop_engine(chip);
 373         lp55xx_unregister_sysfs(chip);
 374         lp55xx_deinit_device(chip);
 375 }
 376
 377 static const struct i2c_device_id lp8501_id[] = {
 378         { "lp8501",  0 },
 379         { }
 380 };
 381 MODULE_DEVICE_TABLE(i2c, lp8501_id);
 382
 383 static const struct of_device_id of_lp8501_leds_match[] = {
 384         { .compatible = "ti,lp8501", },
 385         {},
 386 };
 387
 388 MODULE_DEVICE_TABLE(of, of_lp8501_leds_match);
 389
 390 static struct i2c_driver lp8501_driver = {
 391         .driver = {
 392                 .name   = "lp8501",
 393                 .of_match_table = 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");