drivers/video/backlight/lv5207lp.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Sanyo LV5207LP LED Driver
   4  *
   5  * Copyright (C) 2013 Ideas on board SPRL
   6  *
   7  * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
   8  */
   9
  10 #include <linux/backlight.h>
  11 #include <linux/err.h>
  12 #include <linux/fb.h>
  13 #include <linux/i2c.h>
  14 #include <linux/module.h>
  15 #include <linux/platform_data/lv5207lp.h>
  16 #include <linux/slab.h>
  17
  18 #define LV5207LP_CTRL1                  0x00
  19 #define LV5207LP_CPSW                   (1 << 7)
  20 #define LV5207LP_SCTEN                  (1 << 6)
  21 #define LV5207LP_C10                    (1 << 5)
  22 #define LV5207LP_CKSW                   (1 << 4)
  23 #define LV5207LP_RSW                    (1 << 3)
  24 #define LV5207LP_GSW                    (1 << 2)
  25 #define LV5207LP_BSW                    (1 << 1)
  26 #define LV5207LP_CTRL2                  0x01
  27 #define LV5207LP_MSW                    (1 << 7)
  28 #define LV5207LP_MLED4                  (1 << 6)
  29 #define LV5207LP_RED                    0x02
  30 #define LV5207LP_GREEN                  0x03
  31 #define LV5207LP_BLUE                   0x04
  32
  33 #define LV5207LP_MAX_BRIGHTNESS         32
  34
  35 struct lv5207lp {
  36         struct i2c_client *client;
  37         struct backlight_device *backlight;
  38         struct lv5207lp_platform_data *pdata;
  39 };
  40
  41 static int lv5207lp_write(struct lv5207lp *lv, u8 reg, u8 data)
  42 {
  43         return i2c_smbus_write_byte_data(lv->client, reg, data);
  44 }
  45
  46 static int lv5207lp_backlight_update_status(struct backlight_device *backlight)
  47 {
  48         struct lv5207lp *lv = bl_get_data(backlight);
  49         int brightness = backlight->props.brightness;
  50
  51         if (backlight->props.power != FB_BLANK_UNBLANK ||
  52             backlight->props.fb_blank != FB_BLANK_UNBLANK ||
  53             backlight->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
  54                 brightness = 0;
  55
  56         if (brightness) {
  57                 lv5207lp_write(lv, LV5207LP_CTRL1,
  58                                LV5207LP_CPSW | LV5207LP_C10 | LV5207LP_CKSW);
  59                 lv5207lp_write(lv, LV5207LP_CTRL2,
  60                                LV5207LP_MSW | LV5207LP_MLED4 |
  61                                (brightness - 1));
  62         } else {
  63                 lv5207lp_write(lv, LV5207LP_CTRL1, 0);
  64                 lv5207lp_write(lv, LV5207LP_CTRL2, 0);
  65         }
  66
  67         return 0;
  68 }
  69
  70 static int lv5207lp_backlight_check_fb(struct backlight_device *backlight,
  71                                        struct fb_info *info)
  72 {
  73         struct lv5207lp *lv = bl_get_data(backlight);
  74
  75         return lv->pdata->fbdev == NULL || lv->pdata->fbdev == info->dev;
  76 }
  77
  78 static const struct backlight_ops lv5207lp_backlight_ops = {
  79         .options        = BL_CORE_SUSPENDRESUME,
  80         .update_status  = lv5207lp_backlight_update_status,
  81         .check_fb       = lv5207lp_backlight_check_fb,
  82 };
  83
  84 static int lv5207lp_probe(struct i2c_client *client,
  85                           const struct i2c_device_id *id)
  86 {
  87         struct lv5207lp_platform_data *pdata = dev_get_platdata(&client->dev);
  88         struct backlight_device *backlight;
  89         struct backlight_properties props;
  90         struct lv5207lp *lv;
  91
  92         if (pdata == NULL) {
  93                 dev_err(&client->dev, "No platform data supplied\n");
  94                 return -EINVAL;
  95         }
  96
  97         if (!i2c_check_functionality(client->adapter,
  98                                      I2C_FUNC_SMBUS_BYTE_DATA)) {
  99                 dev_warn(&client->dev,
 100                          "I2C adapter doesn't support I2C_FUNC_SMBUS_BYTE\n");
 101                 return -EIO;
 102         }
 103
 104         lv = devm_kzalloc(&client->dev, sizeof(*lv), GFP_KERNEL);
 105         if (!lv)
 106                 return -ENOMEM;
 107
 108         lv->client = client;
 109         lv->pdata = pdata;
 110
 111         memset(&props, 0, sizeof(props));
 112         props.type = BACKLIGHT_RAW;
 113         props.max_brightness = min_t(unsigned int, pdata->max_value,
 114                                      LV5207LP_MAX_BRIGHTNESS);
 115         props.brightness = clamp_t(unsigned int, pdata->def_value, 0,
 116                                    props.max_brightness);
 117
 118         backlight = devm_backlight_device_register(&client->dev,
 119                                 dev_name(&client->dev), &lv->client->dev,
 120                                 lv, &lv5207lp_backlight_ops, &props);
 121         if (IS_ERR(backlight)) {
 122                 dev_err(&client->dev, "failed to register backlight\n");
 123                 return PTR_ERR(backlight);
 124         }
 125
 126         backlight_update_status(backlight);
 127         i2c_set_clientdata(client, backlight);
 128
 129         return 0;
 130 }
 131
 132 static int lv5207lp_remove(struct i2c_client *client)
 133 {
 134         struct backlight_device *backlight = i2c_get_clientdata(client);
 135
 136         backlight->props.brightness = 0;
 137         backlight_update_status(backlight);
 138
 139         return 0;
 140 }
 141
 142 static const struct i2c_device_id lv5207lp_ids[] = {
 143         { "lv5207lp", 0 },
 144         { }
 145 };
 146 MODULE_DEVICE_TABLE(i2c, lv5207lp_ids);
 147
 148 static struct i2c_driver lv5207lp_driver = {
 149         .driver = {
 150                 .name = "lv5207lp",
 151         },
 152         .probe = lv5207lp_probe,
 153         .remove = lv5207lp_remove,
 154         .id_table = lv5207lp_ids,
 155 };
 156
 157 module_i2c_driver(lv5207lp_driver);
 158
 159 MODULE_DESCRIPTION("Sanyo LV5207LP Backlight Driver");
 160 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
 161 MODULE_LICENSE("GPL");