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