1 /* 2 * Sanyo LV5207LP 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/err.h> 15 #include <linux/fb.h> 16 #include <linux/i2c.h> 17 #include <linux/module.h> 18 #include <linux/platform_data/lv5207lp.h> 19 #include <linux/slab.h> 20 21 #define LV5207LP_CTRL1 0x00 22 #define LV5207LP_CPSW (1 << 7) 23 #define LV5207LP_SCTEN (1 << 6) 24 #define LV5207LP_C10 (1 << 5) 25 #define LV5207LP_CKSW (1 << 4) 26 #define LV5207LP_RSW (1 << 3) 27 #define LV5207LP_GSW (1 << 2) 28 #define LV5207LP_BSW (1 << 1) 29 #define LV5207LP_CTRL2 0x01 30 #define LV5207LP_MSW (1 << 7) 31 #define LV5207LP_MLED4 (1 << 6) 32 #define LV5207LP_RED 0x02 33 #define LV5207LP_GREEN 0x03 34 #define LV5207LP_BLUE 0x04 35 36 #define LV5207LP_MAX_BRIGHTNESS 32 37 38 struct lv5207lp { 39 struct i2c_client *client; 40 struct backlight_device *backlight; 41 struct lv5207lp_platform_data *pdata; 42 }; 43 44 static int lv5207lp_write(struct lv5207lp *lv, u8 reg, u8 data) 45 { 46 return i2c_smbus_write_byte_data(lv->client, reg, data); 47 } 48 49 static int lv5207lp_backlight_update_status(struct backlight_device *backlight) 50 { 51 struct lv5207lp *lv = bl_get_data(backlight); 52 int brightness = backlight->props.brightness; 53 54 if (backlight->props.power != FB_BLANK_UNBLANK || 55 backlight->props.fb_blank != FB_BLANK_UNBLANK || 56 backlight->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK)) 57 brightness = 0; 58 59 if (brightness) { 60 lv5207lp_write(lv, LV5207LP_CTRL1, 61 LV5207LP_CPSW | LV5207LP_C10 | LV5207LP_CKSW); 62 lv5207lp_write(lv, LV5207LP_CTRL2, 63 LV5207LP_MSW | LV5207LP_MLED4 | 64 (brightness - 1)); 65 } else { 66 lv5207lp_write(lv, LV5207LP_CTRL1, 0); 67 lv5207lp_write(lv, LV5207LP_CTRL2, 0); 68 } 69 70 return 0; 71 } 72 73 static int lv5207lp_backlight_check_fb(struct backlight_device *backlight, 74 struct fb_info *info) 75 { 76 struct lv5207lp *lv = bl_get_data(backlight); 77 78 return lv->pdata->fbdev == NULL || lv->pdata->fbdev == info->dev; 79 } 80 81 static const struct backlight_ops lv5207lp_backlight_ops = { 82 .options = BL_CORE_SUSPENDRESUME, 83 .update_status = lv5207lp_backlight_update_status, 84 .check_fb = lv5207lp_backlight_check_fb, 85 }; 86 87 static int lv5207lp_probe(struct i2c_client *client, 88 const struct i2c_device_id *id) 89 { 90 struct lv5207lp_platform_data *pdata = dev_get_platdata(&client->dev); 91 struct backlight_device *backlight; 92 struct backlight_properties props; 93 struct lv5207lp *lv; 94 95 if (pdata == NULL) { 96 dev_err(&client->dev, "No platform data supplied\n"); 97 return -EINVAL; 98 } 99 100 if (!i2c_check_functionality(client->adapter, 101 I2C_FUNC_SMBUS_BYTE_DATA)) { 102 dev_warn(&client->dev, 103 "I2C adapter doesn't support I2C_FUNC_SMBUS_BYTE\n"); 104 return -EIO; 105 } 106 107 lv = devm_kzalloc(&client->dev, sizeof(*lv), GFP_KERNEL); 108 if (!lv) 109 return -ENOMEM; 110 111 lv->client = client; 112 lv->pdata = pdata; 113 114 memset(&props, 0, sizeof(props)); 115 props.type = BACKLIGHT_RAW; 116 props.max_brightness = min_t(unsigned int, pdata->max_value, 117 LV5207LP_MAX_BRIGHTNESS); 118 props.brightness = clamp_t(unsigned int, pdata->def_value, 0, 119 props.max_brightness); 120 121 backlight = devm_backlight_device_register(&client->dev, 122 dev_name(&client->dev), &lv->client->dev, 123 lv, &lv5207lp_backlight_ops, &props); 124 if (IS_ERR(backlight)) { 125 dev_err(&client->dev, "failed to register backlight\n"); 126 return PTR_ERR(backlight); 127 } 128 129 backlight_update_status(backlight); 130 i2c_set_clientdata(client, backlight); 131 132 return 0; 133 } 134 135 static int lv5207lp_remove(struct i2c_client *client) 136 { 137 struct backlight_device *backlight = i2c_get_clientdata(client); 138 139 backlight->props.brightness = 0; 140 backlight_update_status(backlight); 141 142 return 0; 143 } 144 145 static const struct i2c_device_id lv5207lp_ids[] = { 146 { "lv5207lp", 0 }, 147 { } 148 }; 149 MODULE_DEVICE_TABLE(i2c, lv5207lp_ids); 150 151 static struct i2c_driver lv5207lp_driver = { 152 .driver = { 153 .name = "lv5207lp", 154 }, 155 .probe = lv5207lp_probe, 156 .remove = lv5207lp_remove, 157 .id_table = lv5207lp_ids, 158 }; 159 160 module_i2c_driver(lv5207lp_driver); 161 162 MODULE_DESCRIPTION("Sanyo LV5207LP Backlight Driver"); 163 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>"); 164 MODULE_LICENSE("GPL"); 165