linux/drivers/video/backlight/bd6107.c
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   1/*
   2 * ROHM Semiconductor BD6107 LED Driver
   3 *
   4 * Copyright (C) 2013 Ideas on board SPRL
   5 *
   6 * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.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
  13#include <linux/backlight.h>
  14#include <linux/delay.h>
  15#include <linux/err.h>
  16#include <linux/fb.h>
  17#include <linux/gpio.h>
  18#include <linux/i2c.h>
  19#include <linux/module.h>
  20#include <linux/platform_data/bd6107.h>
  21#include <linux/slab.h>
  22
  23#define BD6107_PSCNT1                           0x00
  24#define BD6107_PSCNT1_PSCNTREG2                 (1 << 2)
  25#define BD6107_PSCNT1_PSCNTREG1                 (1 << 0)
  26#define BD6107_REGVSET                          0x02
  27#define BD6107_REGVSET_REG1VSET_2_85V           (1 << 2)
  28#define BD6107_REGVSET_REG1VSET_2_80V           (0 << 2)
  29#define BD6107_LEDCNT1                          0x03
  30#define BD6107_LEDCNT1_LEDONOFF2                (1 << 1)
  31#define BD6107_LEDCNT1_LEDONOFF1                (1 << 0)
  32#define BD6107_PORTSEL                          0x04
  33#define BD6107_PORTSEL_LEDM(n)                  (1 << (n))
  34#define BD6107_RGB1CNT1                         0x05
  35#define BD6107_RGB1CNT2                         0x06
  36#define BD6107_RGB1CNT3                         0x07
  37#define BD6107_RGB1CNT4                         0x08
  38#define BD6107_RGB1CNT5                         0x09
  39#define BD6107_RGB1FLM                          0x0a
  40#define BD6107_RGB2CNT1                         0x0b
  41#define BD6107_RGB2CNT2                         0x0c
  42#define BD6107_RGB2CNT3                         0x0d
  43#define BD6107_RGB2CNT4                         0x0e
  44#define BD6107_RGB2CNT5                         0x0f
  45#define BD6107_RGB2FLM                          0x10
  46#define BD6107_PSCONT3                          0x11
  47#define BD6107_SMMONCNT                         0x12
  48#define BD6107_DCDCCNT                          0x13
  49#define BD6107_IOSEL                            0x14
  50#define BD6107_OUT1                             0x15
  51#define BD6107_OUT2                             0x16
  52#define BD6107_MASK1                            0x17
  53#define BD6107_MASK2                            0x18
  54#define BD6107_FACTOR1                          0x19
  55#define BD6107_FACTOR2                          0x1a
  56#define BD6107_CLRFACT1                         0x1b
  57#define BD6107_CLRFACT2                         0x1c
  58#define BD6107_STATE1                           0x1d
  59#define BD6107_LSIVER                           0x1e
  60#define BD6107_GRPSEL                           0x1f
  61#define BD6107_LEDCNT2                          0x20
  62#define BD6107_LEDCNT3                          0x21
  63#define BD6107_MCURRENT                         0x22
  64#define BD6107_MAINCNT1                         0x23
  65#define BD6107_MAINCNT2                         0x24
  66#define BD6107_SLOPECNT                         0x25
  67#define BD6107_MSLOPE                           0x26
  68#define BD6107_RGBSLOPE                         0x27
  69#define BD6107_TEST                             0x29
  70#define BD6107_SFTRST                           0x2a
  71#define BD6107_SFTRSTGD                         0x2b
  72
  73struct bd6107 {
  74        struct i2c_client *client;
  75        struct backlight_device *backlight;
  76        struct bd6107_platform_data *pdata;
  77};
  78
  79static int bd6107_write(struct bd6107 *bd, u8 reg, u8 data)
  80{
  81        return i2c_smbus_write_byte_data(bd->client, reg, data);
  82}
  83
  84static int bd6107_backlight_update_status(struct backlight_device *backlight)
  85{
  86        struct bd6107 *bd = bl_get_data(backlight);
  87        int brightness = backlight->props.brightness;
  88
  89        if (backlight->props.power != FB_BLANK_UNBLANK ||
  90            backlight->props.fb_blank != FB_BLANK_UNBLANK ||
  91            backlight->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
  92                brightness = 0;
  93
  94        if (brightness) {
  95                bd6107_write(bd, BD6107_PORTSEL, BD6107_PORTSEL_LEDM(2) |
  96                             BD6107_PORTSEL_LEDM(1) | BD6107_PORTSEL_LEDM(0));
  97                bd6107_write(bd, BD6107_MAINCNT1, brightness);
  98                bd6107_write(bd, BD6107_LEDCNT1, BD6107_LEDCNT1_LEDONOFF1);
  99        } else {
 100                gpio_set_value(bd->pdata->reset, 0);
 101                msleep(24);
 102                gpio_set_value(bd->pdata->reset, 1);
 103        }
 104
 105        return 0;
 106}
 107
 108static int bd6107_backlight_check_fb(struct backlight_device *backlight,
 109                                       struct fb_info *info)
 110{
 111        struct bd6107 *bd = bl_get_data(backlight);
 112
 113        return bd->pdata->fbdev == NULL || bd->pdata->fbdev == info->dev;
 114}
 115
 116static const struct backlight_ops bd6107_backlight_ops = {
 117        .options        = BL_CORE_SUSPENDRESUME,
 118        .update_status  = bd6107_backlight_update_status,
 119        .check_fb       = bd6107_backlight_check_fb,
 120};
 121
 122static int bd6107_probe(struct i2c_client *client,
 123                          const struct i2c_device_id *id)
 124{
 125        struct bd6107_platform_data *pdata = dev_get_platdata(&client->dev);
 126        struct backlight_device *backlight;
 127        struct backlight_properties props;
 128        struct bd6107 *bd;
 129        int ret;
 130
 131        if (pdata == NULL || !pdata->reset) {
 132                dev_err(&client->dev, "No reset GPIO in platform data\n");
 133                return -EINVAL;
 134        }
 135
 136        if (!i2c_check_functionality(client->adapter,
 137                                     I2C_FUNC_SMBUS_BYTE_DATA)) {
 138                dev_warn(&client->dev,
 139                         "I2C adapter doesn't support I2C_FUNC_SMBUS_BYTE\n");
 140                return -EIO;
 141        }
 142
 143        bd = devm_kzalloc(&client->dev, sizeof(*bd), GFP_KERNEL);
 144        if (!bd)
 145                return -ENOMEM;
 146
 147        bd->client = client;
 148        bd->pdata = pdata;
 149
 150        ret = devm_gpio_request_one(&client->dev, pdata->reset,
 151                                    GPIOF_DIR_OUT | GPIOF_INIT_LOW, "reset");
 152        if (ret < 0) {
 153                dev_err(&client->dev, "unable to request reset GPIO\n");
 154                return ret;
 155        }
 156
 157        memset(&props, 0, sizeof(props));
 158        props.type = BACKLIGHT_RAW;
 159        props.max_brightness = 128;
 160        props.brightness = clamp_t(unsigned int, pdata->def_value, 0,
 161                                   props.max_brightness);
 162
 163        backlight = devm_backlight_device_register(&client->dev,
 164                                              dev_name(&client->dev),
 165                                              &bd->client->dev, bd,
 166                                              &bd6107_backlight_ops, &props);
 167        if (IS_ERR(backlight)) {
 168                dev_err(&client->dev, "failed to register backlight\n");
 169                return PTR_ERR(backlight);
 170        }
 171
 172        backlight_update_status(backlight);
 173        i2c_set_clientdata(client, backlight);
 174
 175        return 0;
 176}
 177
 178static int bd6107_remove(struct i2c_client *client)
 179{
 180        struct backlight_device *backlight = i2c_get_clientdata(client);
 181
 182        backlight->props.brightness = 0;
 183        backlight_update_status(backlight);
 184
 185        return 0;
 186}
 187
 188static const struct i2c_device_id bd6107_ids[] = {
 189        { "bd6107", 0 },
 190        { }
 191};
 192MODULE_DEVICE_TABLE(i2c, bd6107_ids);
 193
 194static struct i2c_driver bd6107_driver = {
 195        .driver = {
 196                .name = "bd6107",
 197        },
 198        .probe = bd6107_probe,
 199        .remove = bd6107_remove,
 200        .id_table = bd6107_ids,
 201};
 202
 203module_i2c_driver(bd6107_driver);
 204
 205MODULE_DESCRIPTION("Rohm BD6107 Backlight Driver");
 206MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
 207MODULE_LICENSE("GPL");
 208