drivers/video/backlight/platform_lcd.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* drivers/video/backlight/platform_lcd.c
   3  *
   4  * Copyright 2008 Simtec Electronics
   5  *      Ben Dooks <ben@simtec.co.uk>
   6  *
   7  * Generic platform-device LCD power control interface.
   8 */
   9
  10 #include <linux/module.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/fb.h>
  13 #include <linux/backlight.h>
  14 #include <linux/lcd.h>
  15 #include <linux/of.h>
  16 #include <linux/slab.h>
  17
  18 #include <video/platform_lcd.h>
  19
  20 struct platform_lcd {
  21         struct device           *us;
  22         struct lcd_device       *lcd;
  23         struct plat_lcd_data    *pdata;
  24
  25         unsigned int             power;
  26         unsigned int             suspended:1;
  27 };
  28
  29 static inline struct platform_lcd *to_our_lcd(struct lcd_device *lcd)
  30 {
  31         return lcd_get_data(lcd);
  32 }
  33
  34 static int platform_lcd_get_power(struct lcd_device *lcd)
  35 {
  36         struct platform_lcd *plcd = to_our_lcd(lcd);
  37
  38         return plcd->power;
  39 }
  40
  41 static int platform_lcd_set_power(struct lcd_device *lcd, int power)
  42 {
  43         struct platform_lcd *plcd = to_our_lcd(lcd);
  44         int lcd_power = 1;
  45
  46         if (power == FB_BLANK_POWERDOWN || plcd->suspended)
  47                 lcd_power = 0;
  48
  49         plcd->pdata->set_power(plcd->pdata, lcd_power);
  50         plcd->power = power;
  51
  52         return 0;
  53 }
  54
  55 static int platform_lcd_match(struct lcd_device *lcd, struct fb_info *info)
  56 {
  57         struct platform_lcd *plcd = to_our_lcd(lcd);
  58         struct plat_lcd_data *pdata = plcd->pdata;
  59
  60         if (pdata->match_fb)
  61                 return pdata->match_fb(pdata, info);
  62
  63         return plcd->us->parent == info->device;
  64 }
  65
  66 static struct lcd_ops platform_lcd_ops = {
  67         .get_power      = platform_lcd_get_power,
  68         .set_power      = platform_lcd_set_power,
  69         .check_fb       = platform_lcd_match,
  70 };
  71
  72 static int platform_lcd_probe(struct platform_device *pdev)
  73 {
  74         struct plat_lcd_data *pdata;
  75         struct platform_lcd *plcd;
  76         struct device *dev = &pdev->dev;
  77         int err;
  78
  79         pdata = dev_get_platdata(&pdev->dev);
  80         if (!pdata) {
  81                 dev_err(dev, "no platform data supplied\n");
  82                 return -EINVAL;
  83         }
  84
  85         if (pdata->probe) {
  86                 err = pdata->probe(pdata);
  87                 if (err)
  88                         return err;
  89         }
  90
  91         plcd = devm_kzalloc(&pdev->dev, sizeof(struct platform_lcd),
  92                             GFP_KERNEL);
  93         if (!plcd)
  94                 return -ENOMEM;
  95
  96         plcd->us = dev;
  97         plcd->pdata = pdata;
  98         plcd->lcd = devm_lcd_device_register(&pdev->dev, dev_name(dev), dev,
  99                                                 plcd, &platform_lcd_ops);
 100         if (IS_ERR(plcd->lcd)) {
 101                 dev_err(dev, "cannot register lcd device\n");
 102                 return PTR_ERR(plcd->lcd);
 103         }
 104
 105         platform_set_drvdata(pdev, plcd);
 106         platform_lcd_set_power(plcd->lcd, FB_BLANK_NORMAL);
 107
 108         return 0;
 109 }
 110
 111 #ifdef CONFIG_PM_SLEEP
 112 static int platform_lcd_suspend(struct device *dev)
 113 {
 114         struct platform_lcd *plcd = dev_get_drvdata(dev);
 115
 116         plcd->suspended = 1;
 117         platform_lcd_set_power(plcd->lcd, plcd->power);
 118
 119         return 0;
 120 }
 121
 122 static int platform_lcd_resume(struct device *dev)
 123 {
 124         struct platform_lcd *plcd = dev_get_drvdata(dev);
 125
 126         plcd->suspended = 0;
 127         platform_lcd_set_power(plcd->lcd, plcd->power);
 128
 129         return 0;
 130 }
 131 #endif
 132
 133 static SIMPLE_DEV_PM_OPS(platform_lcd_pm_ops, platform_lcd_suspend,
 134                         platform_lcd_resume);
 135
 136 #ifdef CONFIG_OF
 137 static const struct of_device_id platform_lcd_of_match[] = {
 138         { .compatible = "platform-lcd" },
 139         {},
 140 };
 141 MODULE_DEVICE_TABLE(of, platform_lcd_of_match);
 142 #endif
 143
 144 static struct platform_driver platform_lcd_driver = {
 145         .driver         = {
 146                 .name   = "platform-lcd",
 147                 .pm     = &platform_lcd_pm_ops,
 148                 .of_match_table = of_match_ptr(platform_lcd_of_match),
 149         },
 150         .probe          = platform_lcd_probe,
 151 };
 152
 153 module_platform_driver(platform_lcd_driver);
 154
 155 MODULE_AUTHOR("Ben Dooks <ben-linux@fluff.org>");
 156 MODULE_LICENSE("GPL v2");
 157 MODULE_ALIAS("platform:platform-lcd");