drivers/leds/leds-lp55xx-common.c

   1 /*
   2  * LP5521/LP5523/LP55231 Common Driver
   3  *
   4  * Copyright 2012 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 modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  * Derived from leds-lp5521.c, leds-lp5523.c
  13  */
  14
  15 #include <linux/delay.h>
  16 #include <linux/i2c.h>
  17 #include <linux/leds.h>
  18 #include <linux/module.h>
  19 #include <linux/platform_data/leds-lp55xx.h>
  20
  21 #include "leds-lp55xx-common.h"
  22
  23 static void lp55xx_reset_device(struct lp55xx_chip *chip)
  24 {
  25         struct lp55xx_device_config *cfg = chip->cfg;
  26         u8 addr = cfg->reset.addr;
  27         u8 val  = cfg->reset.val;
  28
  29         /* no error checking here because no ACK from the device after reset */
  30         lp55xx_write(chip, addr, val);
  31 }
  32
  33 static int lp55xx_detect_device(struct lp55xx_chip *chip)
  34 {
  35         struct lp55xx_device_config *cfg = chip->cfg;
  36         u8 addr = cfg->enable.addr;
  37         u8 val  = cfg->enable.val;
  38         int ret;
  39
  40         ret = lp55xx_write(chip, addr, val);
  41         if (ret)
  42                 return ret;
  43
  44         usleep_range(1000, 2000);
  45
  46         ret = lp55xx_read(chip, addr, &val);
  47         if (ret)
  48                 return ret;
  49
  50         if (val != cfg->enable.val)
  51                 return -ENODEV;
  52
  53         return 0;
  54 }
  55
  56 static int lp55xx_post_init_device(struct lp55xx_chip *chip)
  57 {
  58         struct lp55xx_device_config *cfg = chip->cfg;
  59
  60         if (!cfg->post_init_device)
  61                 return 0;
  62
  63         return cfg->post_init_device(chip);
  64 }
  65
  66 static int lp55xx_init_led(struct lp55xx_led *led,
  67                         struct lp55xx_chip *chip, int chan)
  68 {
  69         return 0;
  70 }
  71
  72 int lp55xx_write(struct lp55xx_chip *chip, u8 reg, u8 val)
  73 {
  74         return i2c_smbus_write_byte_data(chip->cl, reg, val);
  75 }
  76 EXPORT_SYMBOL_GPL(lp55xx_write);
  77
  78 int lp55xx_read(struct lp55xx_chip *chip, u8 reg, u8 *val)
  79 {
  80         s32 ret;
  81
  82         ret = i2c_smbus_read_byte_data(chip->cl, reg);
  83         if (ret < 0)
  84                 return ret;
  85
  86         *val = ret;
  87         return 0;
  88 }
  89 EXPORT_SYMBOL_GPL(lp55xx_read);
  90
  91 int lp55xx_update_bits(struct lp55xx_chip *chip, u8 reg, u8 mask, u8 val)
  92 {
  93         int ret;
  94         u8 tmp;
  95
  96         ret = lp55xx_read(chip, reg, &tmp);
  97         if (ret)
  98                 return ret;
  99
 100         tmp &= ~mask;
 101         tmp |= val & mask;
 102
 103         return lp55xx_write(chip, reg, tmp);
 104 }
 105 EXPORT_SYMBOL_GPL(lp55xx_update_bits);
 106
 107 int lp55xx_init_device(struct lp55xx_chip *chip)
 108 {
 109         struct lp55xx_platform_data *pdata;
 110         struct lp55xx_device_config *cfg;
 111         struct device *dev = &chip->cl->dev;
 112         int ret = 0;
 113
 114         WARN_ON(!chip);
 115
 116         pdata = chip->pdata;
 117         cfg = chip->cfg;
 118
 119         if (!pdata || !cfg)
 120                 return -EINVAL;
 121
 122         if (pdata->setup_resources) {
 123                 ret = pdata->setup_resources();
 124                 if (ret < 0) {
 125                         dev_err(dev, "setup resoure err: %d\n", ret);
 126                         goto err;
 127                 }
 128         }
 129
 130         if (pdata->enable) {
 131                 pdata->enable(0);
 132                 usleep_range(1000, 2000); /* Keep enable down at least 1ms */
 133                 pdata->enable(1);
 134                 usleep_range(1000, 2000); /* 500us abs min. */
 135         }
 136
 137         lp55xx_reset_device(chip);
 138
 139         /*
 140          * Exact value is not available. 10 - 20ms
 141          * appears to be enough for reset.
 142          */
 143         usleep_range(10000, 20000);
 144
 145         ret = lp55xx_detect_device(chip);
 146         if (ret) {
 147                 dev_err(dev, "device detection err: %d\n", ret);
 148                 goto err;
 149         }
 150
 151         /* chip specific initialization */
 152         ret = lp55xx_post_init_device(chip);
 153         if (ret) {
 154                 dev_err(dev, "post init device err: %d\n", ret);
 155                 goto err_post_init;
 156         }
 157
 158         return 0;
 159
 160 err_post_init:
 161         lp55xx_deinit_device(chip);
 162 err:
 163         return ret;
 164 }
 165 EXPORT_SYMBOL_GPL(lp55xx_init_device);
 166
 167 void lp55xx_deinit_device(struct lp55xx_chip *chip)
 168 {
 169         struct lp55xx_platform_data *pdata = chip->pdata;
 170
 171         if (pdata->enable)
 172                 pdata->enable(0);
 173
 174         if (pdata->release_resources)
 175                 pdata->release_resources();
 176 }
 177 EXPORT_SYMBOL_GPL(lp55xx_deinit_device);
 178
 179 int lp55xx_register_leds(struct lp55xx_led *led, struct lp55xx_chip *chip)
 180 {
 181         struct lp55xx_platform_data *pdata = chip->pdata;
 182         struct lp55xx_device_config *cfg = chip->cfg;
 183         int num_channels = pdata->num_channels;
 184         struct lp55xx_led *each;
 185         u8 led_current;
 186         int ret;
 187         int i;
 188
 189         if (!cfg->brightness_work_fn) {
 190                 dev_err(&chip->cl->dev, "empty brightness configuration\n");
 191                 return -EINVAL;
 192         }
 193
 194         for (i = 0; i < num_channels; i++) {
 195
 196                 /* do not initialize channels that are not connected */
 197                 if (pdata->led_config[i].led_current == 0)
 198                         continue;
 199
 200                 led_current = pdata->led_config[i].led_current;
 201                 each = led + i;
 202                 ret = lp55xx_init_led(each, chip, i);
 203                 if (ret)
 204                         goto err_init_led;
 205
 206                 INIT_WORK(&each->brightness_work, cfg->brightness_work_fn);
 207
 208                 chip->num_leds++;
 209                 each->chip = chip;
 210
 211                 /* setting led current at each channel */
 212                 if (cfg->set_led_current)
 213                         cfg->set_led_current(each, led_current);
 214         }
 215
 216         return 0;
 217
 218 err_init_led:
 219         for (i = 0; i < chip->num_leds; i++) {
 220                 each = led + i;
 221                 led_classdev_unregister(&each->cdev);
 222                 flush_work(&each->brightness_work);
 223         }
 224         return ret;
 225 }
 226 EXPORT_SYMBOL_GPL(lp55xx_register_leds);
 227
 228 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
 229 MODULE_DESCRIPTION("LP55xx Common Driver");
 230 MODULE_LICENSE("GPL");