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 20 #include <video/platform_lcd.h> 21 22 struct platform_lcd { 23 struct device *us; 24 struct lcd_device *lcd; 25 struct plat_lcd_data *pdata; 26 27 unsigned int power; 28 unsigned int suspended : 1; 29 }; 30 31 static inline struct platform_lcd *to_our_lcd(struct lcd_device *lcd) 32 { 33 return lcd_get_data(lcd); 34 } 35 36 static int platform_lcd_get_power(struct lcd_device *lcd) 37 { 38 struct platform_lcd *plcd = to_our_lcd(lcd); 39 40 return plcd->power; 41 } 42 43 static int platform_lcd_set_power(struct lcd_device *lcd, int power) 44 { 45 struct platform_lcd *plcd = to_our_lcd(lcd); 46 int lcd_power = 1; 47 48 if (power == FB_BLANK_POWERDOWN || plcd->suspended) 49 lcd_power = 0; 50 51 plcd->pdata->set_power(plcd->pdata, lcd_power); 52 plcd->power = power; 53 54 return 0; 55 } 56 57 static int platform_lcd_match(struct lcd_device *lcd, struct fb_info *info) 58 { 59 struct platform_lcd *plcd = to_our_lcd(lcd); 60 struct plat_lcd_data *pdata = plcd->pdata; 61 62 if (pdata->match_fb) 63 return pdata->match_fb(pdata, info); 64 65 return plcd->us->parent == info->device; 66 } 67 68 static struct lcd_ops platform_lcd_ops = { 69 .get_power = platform_lcd_get_power, 70 .set_power = platform_lcd_set_power, 71 .check_fb = platform_lcd_match, 72 }; 73 74 static int __devinit platform_lcd_probe(struct platform_device *pdev) 75 { 76 struct plat_lcd_data *pdata; 77 struct platform_lcd *plcd; 78 struct device *dev = &pdev->dev; 79 int err; 80 81 pdata = pdev->dev.platform_data; 82 if (!pdata) { 83 dev_err(dev, "no platform data supplied\n"); 84 return -EINVAL; 85 } 86 87 plcd = kzalloc(sizeof(struct platform_lcd), GFP_KERNEL); 88 if (!plcd) { 89 dev_err(dev, "no memory for state\n"); 90 return -ENOMEM; 91 } 92 93 plcd->us = dev; 94 plcd->pdata = pdata; 95 plcd->lcd = lcd_device_register(dev_name(dev), dev, 96 plcd, &platform_lcd_ops); 97 if (IS_ERR(plcd->lcd)) { 98 dev_err(dev, "cannot register lcd device\n"); 99 err = PTR_ERR(plcd->lcd); 100 goto err_mem; 101 } 102 103 platform_set_drvdata(pdev, plcd); 104 platform_lcd_set_power(plcd->lcd, FB_BLANK_NORMAL); 105 106 return 0; 107 108 err_mem: 109 kfree(plcd); 110 return err; 111 } 112 113 static int __devexit platform_lcd_remove(struct platform_device *pdev) 114 { 115 struct platform_lcd *plcd = platform_get_drvdata(pdev); 116 117 lcd_device_unregister(plcd->lcd); 118 kfree(plcd); 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 static int __init platform_lcd_init(void) 160 { 161 return platform_driver_register(&platform_lcd_driver); 162 } 163 164 static void __exit platform_lcd_cleanup(void) 165 { 166 platform_driver_unregister(&platform_lcd_driver); 167 } 168 169 module_init(platform_lcd_init); 170 module_exit(platform_lcd_cleanup); 171 172 MODULE_AUTHOR("Ben Dooks <ben-linux@fluff.org>"); 173 MODULE_LICENSE("GPL v2"); 174 MODULE_ALIAS("platform:platform-lcd"); 175