1 /* 2 * Backlight Driver for HP Jornada 680 3 * 4 * Copyright (c) 2005 Andriy Skulysh 5 * 6 * Based on Sharp's Corgi Backlight Driver 7 * 8 * This file is subject to the terms and conditions of the GNU General Public 9 * License. See the file "COPYING" in the main directory of this archive 10 * for more details. 11 */ 12 13 #include <linux/module.h> 14 #include <linux/kernel.h> 15 #include <linux/init.h> 16 #include <linux/platform_device.h> 17 #include <linux/spinlock.h> 18 #include <linux/fb.h> 19 #include <linux/backlight.h> 20 21 #include <cpu/dac.h> 22 #include <mach/hp6xx.h> 23 #include <asm/hd64461.h> 24 25 #define HP680_MAX_INTENSITY 255 26 #define HP680_DEFAULT_INTENSITY 10 27 28 static int hp680bl_suspended; 29 static int current_intensity = 0; 30 static DEFINE_SPINLOCK(bl_lock); 31 32 static void hp680bl_send_intensity(struct backlight_device *bd) 33 { 34 unsigned long flags; 35 u16 v; 36 int intensity = bd->props.brightness; 37 38 if (bd->props.power != FB_BLANK_UNBLANK) 39 intensity = 0; 40 if (bd->props.fb_blank != FB_BLANK_UNBLANK) 41 intensity = 0; 42 if (hp680bl_suspended) 43 intensity = 0; 44 45 spin_lock_irqsave(&bl_lock, flags); 46 if (intensity && current_intensity == 0) { 47 sh_dac_enable(DAC_LCD_BRIGHTNESS); 48 v = inw(HD64461_GPBDR); 49 v &= ~HD64461_GPBDR_LCDOFF; 50 outw(v, HD64461_GPBDR); 51 sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS); 52 } else if (intensity == 0 && current_intensity != 0) { 53 sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS); 54 sh_dac_disable(DAC_LCD_BRIGHTNESS); 55 v = inw(HD64461_GPBDR); 56 v |= HD64461_GPBDR_LCDOFF; 57 outw(v, HD64461_GPBDR); 58 } else if (intensity) { 59 sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS); 60 } 61 spin_unlock_irqrestore(&bl_lock, flags); 62 63 current_intensity = intensity; 64 } 65 66 67 #ifdef CONFIG_PM 68 static int hp680bl_suspend(struct platform_device *pdev, pm_message_t state) 69 { 70 struct backlight_device *bd = platform_get_drvdata(pdev); 71 72 hp680bl_suspended = 1; 73 hp680bl_send_intensity(bd); 74 return 0; 75 } 76 77 static int hp680bl_resume(struct platform_device *pdev) 78 { 79 struct backlight_device *bd = platform_get_drvdata(pdev); 80 81 hp680bl_suspended = 0; 82 hp680bl_send_intensity(bd); 83 return 0; 84 } 85 #else 86 #define hp680bl_suspend NULL 87 #define hp680bl_resume NULL 88 #endif 89 90 static int hp680bl_set_intensity(struct backlight_device *bd) 91 { 92 hp680bl_send_intensity(bd); 93 return 0; 94 } 95 96 static int hp680bl_get_intensity(struct backlight_device *bd) 97 { 98 return current_intensity; 99 } 100 101 static const struct backlight_ops hp680bl_ops = { 102 .get_brightness = hp680bl_get_intensity, 103 .update_status = hp680bl_set_intensity, 104 }; 105 106 static int __devinit hp680bl_probe(struct platform_device *pdev) 107 { 108 struct backlight_properties props; 109 struct backlight_device *bd; 110 111 memset(&props, 0, sizeof(struct backlight_properties)); 112 props.max_brightness = HP680_MAX_INTENSITY; 113 bd = backlight_device_register("hp680-bl", &pdev->dev, NULL, 114 &hp680bl_ops, &props); 115 if (IS_ERR(bd)) 116 return PTR_ERR(bd); 117 118 platform_set_drvdata(pdev, bd); 119 120 bd->props.brightness = HP680_DEFAULT_INTENSITY; 121 hp680bl_send_intensity(bd); 122 123 return 0; 124 } 125 126 static int hp680bl_remove(struct platform_device *pdev) 127 { 128 struct backlight_device *bd = platform_get_drvdata(pdev); 129 130 bd->props.brightness = 0; 131 bd->props.power = 0; 132 hp680bl_send_intensity(bd); 133 134 backlight_device_unregister(bd); 135 136 return 0; 137 } 138 139 static struct platform_driver hp680bl_driver = { 140 .probe = hp680bl_probe, 141 .remove = hp680bl_remove, 142 .suspend = hp680bl_suspend, 143 .resume = hp680bl_resume, 144 .driver = { 145 .name = "hp680-bl", 146 }, 147 }; 148 149 static struct platform_device *hp680bl_device; 150 151 static int __init hp680bl_init(void) 152 { 153 int ret; 154 155 ret = platform_driver_register(&hp680bl_driver); 156 if (ret) 157 return ret; 158 hp680bl_device = platform_device_register_simple("hp680-bl", -1, 159 NULL, 0); 160 if (IS_ERR(hp680bl_device)) { 161 platform_driver_unregister(&hp680bl_driver); 162 return PTR_ERR(hp680bl_device); 163 } 164 return 0; 165 } 166 167 static void __exit hp680bl_exit(void) 168 { 169 platform_device_unregister(hp680bl_device); 170 platform_driver_unregister(&hp680bl_driver); 171 } 172 173 module_init(hp680bl_init); 174 module_exit(hp680bl_exit); 175 176 MODULE_AUTHOR("Andriy Skulysh <askulysh@gmail.com>"); 177 MODULE_DESCRIPTION("HP Jornada 680 Backlight Driver"); 178 MODULE_LICENSE("GPL"); 179