linux/drivers/leds/leds-lp8501.c
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   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
  82static inline void lp8501_wait_opmode_done(void)
  83{
  84        usleep_range(1000, 2000);
  85}
  86
  87static 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
  94static 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
 118static 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
 146static 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
 152static 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
 160static 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
 208static 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
 250err:
 251        dev_err(&chip->cl->dev, "wrong pattern format\n");
 252        return -EINVAL;
 253}
 254
 255static 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
 275static 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 */
 288static 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
 305static 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
 361err_register_sysfs:
 362        lp55xx_unregister_leds(led, chip);
 363err_register_leds:
 364        lp55xx_deinit_device(chip);
 365err_init:
 366        return ret;
 367}
 368
 369static 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
 382static const struct i2c_device_id lp8501_id[] = {
 383        { "lp8501",  0 },
 384        { }
 385};
 386MODULE_DEVICE_TABLE(i2c, lp8501_id);
 387
 388#ifdef CONFIG_OF
 389static const struct of_device_id of_lp8501_leds_match[] = {
 390        { .compatible = "ti,lp8501", },
 391        {},
 392};
 393
 394MODULE_DEVICE_TABLE(of, of_lp8501_leds_match);
 395#endif
 396
 397static 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
 407module_i2c_driver(lp8501_driver);
 408
 409MODULE_DESCRIPTION("Texas Instruments LP8501 LED drvier");
 410MODULE_AUTHOR("Milo Kim");
 411MODULE_LICENSE("GPL");
 412
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