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/slab.h> 20 21 #include <video/platform_lcd.h> 22 23 struct platform_lcd { 24 struct device *us; 25 struct lcd_device *lcd; 26 struct plat_lcd_data *pdata; 27 28 unsigned int power; 29 unsigned int suspended : 1; 30 }; 31 32 static inline struct platform_lcd *to_our_lcd(struct lcd_device *lcd) 33 { 34 return lcd_get_data(lcd); 35 } 36 37 static int platform_lcd_get_power(struct lcd_device *lcd) 38 { 39 struct platform_lcd *plcd = to_our_lcd(lcd); 40 41 return plcd->power; 42 } 43 44 static int platform_lcd_set_power(struct lcd_device *lcd, int power) 45 { 46 struct platform_lcd *plcd = to_our_lcd(lcd); 47 int lcd_power = 1; 48 49 if (power == FB_BLANK_POWERDOWN || plcd->suspended) 50 lcd_power = 0; 51 52 plcd->pdata->set_power(plcd->pdata, lcd_power); 53 plcd->power = power; 54 55 return 0; 56 } 57 58 static int platform_lcd_match(struct lcd_device *lcd, struct fb_info *info) 59 { 60 struct platform_lcd *plcd = to_our_lcd(lcd); 61 struct plat_lcd_data *pdata = plcd->pdata; 62 63 if (pdata->match_fb) 64 return pdata->match_fb(pdata, info); 65 66 return plcd->us->parent == info->device; 67 } 68 69 static struct lcd_ops platform_lcd_ops = { 70 .get_power = platform_lcd_get_power, 71 .set_power = platform_lcd_set_power, 72 .check_fb = platform_lcd_match, 73 }; 74 75 static int __devinit platform_lcd_probe(struct platform_device *pdev) 76 { 77 struct plat_lcd_data *pdata; 78 struct platform_lcd *plcd; 79 struct device *dev = &pdev->dev; 80 int err; 81 82 pdata = pdev->dev.platform_data; 83 if (!pdata) { 84 dev_err(dev, "no platform data supplied\n"); 85 return -EINVAL; 86 } 87 88 plcd = devm_kzalloc(&pdev->dev, sizeof(struct platform_lcd), 89 GFP_KERNEL); 90 if (!plcd) { 91 dev_err(dev, "no memory for state\n"); 92 return -ENOMEM; 93 } 94 95 plcd->us = dev; 96 plcd->pdata = pdata; 97 plcd->lcd = lcd_device_register(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 err = PTR_ERR(plcd->lcd); 102 goto err; 103 } 104 105 platform_set_drvdata(pdev, plcd); 106 platform_lcd_set_power(plcd->lcd, FB_BLANK_NORMAL); 107 108 return 0; 109 110 err: 111 return err; 112 } 113 114 static int __devexit platform_lcd_remove(struct platform_device *pdev) 115 { 116 struct platform_lcd *plcd = platform_get_drvdata(pdev); 117 118 lcd_device_unregister(plcd->lcd); 119 120 return 0; 121 } 122 123 #ifdef CONFIG_PM 124 static int platform_lcd_suspend(struct platform_device *pdev, pm_message_t st) 125 { 126 struct platform_lcd *plcd = platform_get_drvdata(pdev); 127 128 plcd->suspended = 1; 129 platform_lcd_set_power(plcd->lcd, plcd->power); 130 131 return 0; 132 } 133 134 static int platform_lcd_resume(struct platform_device *pdev) 135 { 136 struct platform_lcd *plcd = platform_get_drvdata(pdev); 137 138 plcd->suspended = 0; 139 platform_lcd_set_power(plcd->lcd, plcd->power); 140 141 return 0; 142 } 143 #else 144 #define platform_lcd_suspend NULL 145 #define platform_lcd_resume NULL 146 #endif 147 148 static struct platform_driver platform_lcd_driver = { 149 .driver = { 150 .name = "platform-lcd", 151 .owner = THIS_MODULE, 152 }, 153 .probe = platform_lcd_probe, 154 .remove = __devexit_p(platform_lcd_remove), 155 .suspend = platform_lcd_suspend, 156 .resume = platform_lcd_resume, 157 }; 158 159 module_platform_driver(platform_lcd_driver); 160 161 MODULE_AUTHOR("Ben Dooks <ben-linux@fluff.org>"); 162 MODULE_LICENSE("GPL v2"); 163 MODULE_ALIAS("platform:platform-lcd"); 164