LXR linux/drivers/video/backlight/platform

   1/* drivers/video/backlight/platform_lcd.c
   2 *
   3 * Copyright 2008 Simtec Electronics
   4 *      Ben Dooks <ben@simtec.co.uk>
   5 *
   6 * Generic platform-device LCD power control interface.
   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
  14#include <linux/module.h>
  15#include <linux/platform_device.h>
  16#include <linux/fb.h>
  17#include <linux/backlight.h>
  18#include <linux/lcd.h>
  19#include <linux/of.h>
  20#include <linux/slab.h>
  21
  22#include <video/platform_lcd.h>
  23
  24struct platform_lcd {
  25        struct device           *us;
  26        struct lcd_device       *lcd;
  27        struct plat_lcd_data    *pdata;
  28
  29        unsigned int             power;
  30        unsigned int             suspended:1;
  31};
  32
  33static inline struct platform_lcd *to_our_lcd(struct lcd_device *lcd)
  34{
  35        return lcd_get_data(lcd);
  36}
  37
  38static int platform_lcd_get_power(struct lcd_device *lcd)
  39{
  40        struct platform_lcd *plcd = to_our_lcd(lcd);
  41
  42        return plcd->power;
  43}
  44
  45static int platform_lcd_set_power(struct lcd_device *lcd, int power)
  46{
  47        struct platform_lcd *plcd = to_our_lcd(lcd);
  48        int lcd_power = 1;
  49
  50        if (power == FB_BLANK_POWERDOWN || plcd->suspended)
  51                lcd_power = 0;
  52
  53        plcd->pdata->set_power(plcd->pdata, lcd_power);
  54        plcd->power = power;
  55
  56        return 0;
  57}
  58
  59static int platform_lcd_match(struct lcd_device *lcd, struct fb_info *info)
  60{
  61        struct platform_lcd *plcd = to_our_lcd(lcd);
  62        struct plat_lcd_data *pdata = plcd->pdata;
  63
  64        if (pdata->match_fb)
  65                return pdata->match_fb(pdata, info);
  66
  67        return plcd->us->parent == info->device;
  68}
  69
  70static struct lcd_ops platform_lcd_ops = {
  71        .get_power      = platform_lcd_get_power,
  72        .set_power      = platform_lcd_set_power,
  73        .check_fb       = platform_lcd_match,
  74};
  75
  76static int platform_lcd_probe(struct platform_device *pdev)
  77{
  78        struct plat_lcd_data *pdata;
  79        struct platform_lcd *plcd;
  80        struct device *dev = &pdev->dev;
  81        int err;
  82
  83        pdata = pdev->dev.platform_data;
  84        if (!pdata) {
  85                dev_err(dev, "no platform data supplied\n");
  86                return -EINVAL;
  87        }
  88
  89        plcd = devm_kzalloc(&pdev->dev, sizeof(struct platform_lcd),
  90                            GFP_KERNEL);
  91        if (!plcd) {
  92                dev_err(dev, "no memory for state\n");
  93                return -ENOMEM;
  94        }
  95
  96        plcd->us = dev;
  97        plcd->pdata = pdata;
  98        plcd->lcd = lcd_device_register(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                err = PTR_ERR(plcd->lcd);
 103                goto err;
 104        }
 105
 106        platform_set_drvdata(pdev, plcd);
 107        platform_lcd_set_power(plcd->lcd, FB_BLANK_NORMAL);
 108
 109        return 0;
 110
 111 err:
 112        return err;
 113}
 114
 115static int platform_lcd_remove(struct platform_device *pdev)
 116{
 117        struct platform_lcd *plcd = platform_get_drvdata(pdev);
 118
 119        lcd_device_unregister(plcd->lcd);
 120
 121        return 0;
 122}
 123
 124#ifdef CONFIG_PM
 125static int platform_lcd_suspend(struct device *dev)
 126{
 127        struct platform_lcd *plcd = dev_get_drvdata(dev);
 128
 129        plcd->suspended = 1;
 130        platform_lcd_set_power(plcd->lcd, plcd->power);
 131
 132        return 0;
 133}
 134
 135static int platform_lcd_resume(struct device *dev)
 136{
 137        struct platform_lcd *plcd = dev_get_drvdata(dev);
 138
 139        plcd->suspended = 0;
 140        platform_lcd_set_power(plcd->lcd, plcd->power);
 141
 142        return 0;
 143}
 144
 145static SIMPLE_DEV_PM_OPS(platform_lcd_pm_ops, platform_lcd_suspend,
 146                        platform_lcd_resume);
 147#endif
 148
 149#ifdef CONFIG_OF
 150static const struct of_device_id platform_lcd_of_match[] = {
 151        { .compatible = "platform-lcd" },
 152        {},
 153};
 154MODULE_DEVICE_TABLE(of, platform_lcd_of_match);
 155#endif
 156
 157static struct platform_driver platform_lcd_driver = {
 158        .driver         = {
 159                .name   = "platform-lcd",
 160                .owner  = THIS_MODULE,
 161#ifdef CONFIG_PM
 162                .pm     = &platform_lcd_pm_ops,
 163#endif
 164                .of_match_table = of_match_ptr(platform_lcd_of_match),
 165        },
 166        .probe          = platform_lcd_probe,
 167        .remove         = platform_lcd_remove,
 168};
 169
 170module_platform_driver(platform_lcd_driver);
 171
 172MODULE_AUTHOR("Ben Dooks <ben-linux@fluff.org>");
 173MODULE_LICENSE("GPL v2");
 174MODULE_ALIAS("platform:platform-lcd");
 175