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 24 struct 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 33 static inline struct platform_lcd *to_our_lcd(struct lcd_device *lcd) 34 { 35 return lcd_get_data(lcd); 36 } 37 38 static 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 45 static 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 59 static 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 70 static 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 76 static 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 = dev_get_platdata(&pdev->dev); 84 if (!pdata) { 85 dev_err(dev, "no platform data supplied\n"); 86 return -EINVAL; 87 } 88 89 if (pdata->probe) { 90 err = pdata->probe(pdata); 91 if (err) 92 return err; 93 } 94 95 plcd = devm_kzalloc(&pdev->dev, sizeof(struct platform_lcd), 96 GFP_KERNEL); 97 if (!plcd) 98 return -ENOMEM; 99 100 plcd->us = dev; 101 plcd->pdata = pdata; 102 plcd->lcd = devm_lcd_device_register(&pdev->dev, dev_name(dev), dev, 103 plcd, &platform_lcd_ops); 104 if (IS_ERR(plcd->lcd)) { 105 dev_err(dev, "cannot register lcd device\n"); 106 return PTR_ERR(plcd->lcd); 107 } 108 109 platform_set_drvdata(pdev, plcd); 110 platform_lcd_set_power(plcd->lcd, FB_BLANK_NORMAL); 111 112 return 0; 113 } 114 115 #ifdef CONFIG_PM_SLEEP 116 static int platform_lcd_suspend(struct device *dev) 117 { 118 struct platform_lcd *plcd = dev_get_drvdata(dev); 119 120 plcd->suspended = 1; 121 platform_lcd_set_power(plcd->lcd, plcd->power); 122 123 return 0; 124 } 125 126 static int platform_lcd_resume(struct device *dev) 127 { 128 struct platform_lcd *plcd = dev_get_drvdata(dev); 129 130 plcd->suspended = 0; 131 platform_lcd_set_power(plcd->lcd, plcd->power); 132 133 return 0; 134 } 135 #endif 136 137 static SIMPLE_DEV_PM_OPS(platform_lcd_pm_ops, platform_lcd_suspend, 138 platform_lcd_resume); 139 140 #ifdef CONFIG_OF 141 static const struct of_device_id platform_lcd_of_match[] = { 142 { .compatible = "platform-lcd" }, 143 {}, 144 }; 145 MODULE_DEVICE_TABLE(of, platform_lcd_of_match); 146 #endif 147 148 static struct platform_driver platform_lcd_driver = { 149 .driver = { 150 .name = "platform-lcd", 151 .pm = &platform_lcd_pm_ops, 152 .of_match_table = of_match_ptr(platform_lcd_of_match), 153 }, 154 .probe = platform_lcd_probe, 155 }; 156 157 module_platform_driver(platform_lcd_driver); 158 159 MODULE_AUTHOR("Ben Dooks <ben-linux@fluff.org>"); 160 MODULE_LICENSE("GPL v2"); 161 MODULE_ALIAS("platform:platform-lcd"); 162