linux/drivers/video/backlight/platform_lcd.c
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   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
  20struct 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
  29static inline struct platform_lcd *to_our_lcd(struct lcd_device *lcd)
  30{
  31        return lcd_get_data(lcd);
  32}
  33
  34static 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
  41static 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
  55static 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
  66static 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
  72static 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
 112static 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
 122static 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
 133static SIMPLE_DEV_PM_OPS(platform_lcd_pm_ops, platform_lcd_suspend,
 134                        platform_lcd_resume);
 135
 136#ifdef CONFIG_OF
 137static const struct of_device_id platform_lcd_of_match[] = {
 138        { .compatible = "platform-lcd" },
 139        {},
 140};
 141MODULE_DEVICE_TABLE(of, platform_lcd_of_match);
 142#endif
 143
 144static 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
 153module_platform_driver(platform_lcd_driver);
 154
 155MODULE_AUTHOR("Ben Dooks <ben-linux@fluff.org>");
 156MODULE_LICENSE("GPL v2");
 157MODULE_ALIAS("platform:platform-lcd");
 158