kernel/drivers/video/backlight/bd6107.c

   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
  73 struct bd6107 {
  74         struct i2c_client *client;
  75         struct backlight_device *backlight;
  76         struct bd6107_platform_data *pdata;
  77 };
  78
  79 static int bd6107_write(struct bd6107 *bd, u8 reg, u8 data)
  80 {
  81         return i2c_smbus_write_byte_data(bd->client, reg, data);
  82 }
  83
  84 static 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
 108 static 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
 116 static 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
 122 static 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
 178 static 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
 188 static const struct i2c_device_id bd6107_ids[] = {
 189         { "bd6107", 0 },
 190         { }
 191 };
 192 MODULE_DEVICE_TABLE(i2c, bd6107_ids);
 193
 194 static 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
 203 module_i2c_driver(bd6107_driver);
 204
 205 MODULE_DESCRIPTION("Rohm BD6107 Backlight Driver");
 206 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
 207 MODULE_LICENSE("GPL");