video/backlight/platform_lcd.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /* drivers/video/backlight/platform_lcd.c
0003  *
0004  * Copyright 2008 Simtec Electronics
0005  *  Ben Dooks <ben@simtec.co.uk>
0006  *
0007  * Generic platform-device LCD power control interface.
0008 */
0009
0010 #include <linux/module.h>
0011 #include <linux/platform_device.h>
0012 #include <linux/fb.h>
0013 #include <linux/backlight.h>
0014 #include <linux/lcd.h>
0015 #include <linux/slab.h>
0016
0017 #include <video/platform_lcd.h>
0018
0019 struct platform_lcd {
0020     struct device       *us;
0021     struct lcd_device   *lcd;
0022     struct plat_lcd_data    *pdata;
0023
0024     unsigned int         power;
0025     unsigned int         suspended:1;
0026 };
0027
0028 static inline struct platform_lcd *to_our_lcd(struct lcd_device *lcd)
0029 {
0030     return lcd_get_data(lcd);
0031 }
0032
0033 static int platform_lcd_get_power(struct lcd_device *lcd)
0034 {
0035     struct platform_lcd *plcd = to_our_lcd(lcd);
0036
0037     return plcd->power;
0038 }
0039
0040 static int platform_lcd_set_power(struct lcd_device *lcd, int power)
0041 {
0042     struct platform_lcd *plcd = to_our_lcd(lcd);
0043     int lcd_power = 1;
0044
0045     if (power == FB_BLANK_POWERDOWN || plcd->suspended)
0046         lcd_power = 0;
0047
0048     plcd->pdata->set_power(plcd->pdata, lcd_power);
0049     plcd->power = power;
0050
0051     return 0;
0052 }
0053
0054 static int platform_lcd_match(struct lcd_device *lcd, struct fb_info *info)
0055 {
0056     struct platform_lcd *plcd = to_our_lcd(lcd);
0057     struct plat_lcd_data *pdata = plcd->pdata;
0058
0059     if (pdata->match_fb)
0060         return pdata->match_fb(pdata, info);
0061
0062     return plcd->us->parent == info->device;
0063 }
0064
0065 static struct lcd_ops platform_lcd_ops = {
0066     .get_power  = platform_lcd_get_power,
0067     .set_power  = platform_lcd_set_power,
0068     .check_fb   = platform_lcd_match,
0069 };
0070
0071 static int platform_lcd_probe(struct platform_device *pdev)
0072 {
0073     struct plat_lcd_data *pdata;
0074     struct platform_lcd *plcd;
0075     struct device *dev = &pdev->dev;
0076     int err;
0077
0078     pdata = dev_get_platdata(&pdev->dev);
0079     if (!pdata) {
0080         dev_err(dev, "no platform data supplied\n");
0081         return -EINVAL;
0082     }
0083
0084     if (pdata->probe) {
0085         err = pdata->probe(pdata);
0086         if (err)
0087             return err;
0088     }
0089
0090     plcd = devm_kzalloc(&pdev->dev, sizeof(struct platform_lcd),
0091                 GFP_KERNEL);
0092     if (!plcd)
0093         return -ENOMEM;
0094
0095     plcd->us = dev;
0096     plcd->pdata = pdata;
0097     plcd->lcd = devm_lcd_device_register(&pdev->dev, dev_name(dev), dev,
0098                         plcd, &platform_lcd_ops);
0099     if (IS_ERR(plcd->lcd)) {
0100         dev_err(dev, "cannot register lcd device\n");
0101         return PTR_ERR(plcd->lcd);
0102     }
0103
0104     platform_set_drvdata(pdev, plcd);
0105     platform_lcd_set_power(plcd->lcd, FB_BLANK_NORMAL);
0106
0107     return 0;
0108 }
0109
0110 #ifdef CONFIG_PM_SLEEP
0111 static int platform_lcd_suspend(struct device *dev)
0112 {
0113     struct platform_lcd *plcd = dev_get_drvdata(dev);
0114
0115     plcd->suspended = 1;
0116     platform_lcd_set_power(plcd->lcd, plcd->power);
0117
0118     return 0;
0119 }
0120
0121 static int platform_lcd_resume(struct device *dev)
0122 {
0123     struct platform_lcd *plcd = dev_get_drvdata(dev);
0124
0125     plcd->suspended = 0;
0126     platform_lcd_set_power(plcd->lcd, plcd->power);
0127
0128     return 0;
0129 }
0130 #endif
0131
0132 static SIMPLE_DEV_PM_OPS(platform_lcd_pm_ops, platform_lcd_suspend,
0133             platform_lcd_resume);
0134
0135 static struct platform_driver platform_lcd_driver = {
0136     .driver     = {
0137         .name   = "platform-lcd",
0138         .pm = &platform_lcd_pm_ops,
0139     },
0140     .probe      = platform_lcd_probe,
0141 };
0142
0143 module_platform_driver(platform_lcd_driver);
0144
0145 MODULE_AUTHOR("Ben Dooks <ben-linux@fluff.org>");
0146 MODULE_LICENSE("GPL v2");
0147 MODULE_ALIAS("platform:platform-lcd");