Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * Backlight Driver for Sharp Corgi |
| 3 | * |
| 4 | * Copyright (c) 2004-2005 Richard Purdie |
| 5 | * |
| 6 | * Based on Sharp's 2.4 Backlight Driver |
| 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/kernel.h> |
| 16 | #include <linux/init.h> |
| 17 | #include <linux/device.h> |
| 18 | #include <linux/spinlock.h> |
| 19 | #include <linux/fb.h> |
| 20 | #include <linux/backlight.h> |
| 21 | |
| 22 | #include <asm/arch-pxa/corgi.h> |
| 23 | #include <asm/hardware/scoop.h> |
| 24 | |
| 25 | #define CORGI_MAX_INTENSITY 0x3e |
| 26 | #define CORGI_DEFAULT_INTENSITY 0x1f |
| 27 | #define CORGI_LIMIT_MASK 0x0b |
| 28 | |
| 29 | static int corgibl_powermode = FB_BLANK_UNBLANK; |
| 30 | static int current_intensity = 0; |
| 31 | static int corgibl_limit = 0; |
| 32 | static spinlock_t bl_lock = SPIN_LOCK_UNLOCKED; |
| 33 | |
| 34 | static void corgibl_send_intensity(int intensity) |
| 35 | { |
| 36 | unsigned long flags; |
| 37 | void (*corgi_kick_batt)(void); |
| 38 | |
| 39 | if (corgibl_powermode != FB_BLANK_UNBLANK) { |
| 40 | intensity = 0; |
| 41 | } else { |
| 42 | if (corgibl_limit) |
| 43 | intensity &= CORGI_LIMIT_MASK; |
| 44 | } |
| 45 | |
| 46 | /* Skip 0x20 as it will blank the display */ |
| 47 | if (intensity >= 0x20) |
| 48 | intensity++; |
| 49 | |
| 50 | spin_lock_irqsave(&bl_lock, flags); |
| 51 | /* Bits 0-4 are accessed via the SSP interface */ |
| 52 | corgi_ssp_blduty_set(intensity & 0x1f); |
| 53 | /* Bit 5 is via SCOOP */ |
| 54 | if (intensity & 0x0020) |
| 55 | set_scoop_gpio(&corgiscoop_device.dev, CORGI_SCP_BACKLIGHT_CONT); |
| 56 | else |
| 57 | reset_scoop_gpio(&corgiscoop_device.dev, CORGI_SCP_BACKLIGHT_CONT); |
| 58 | spin_unlock_irqrestore(&bl_lock, flags); |
| 59 | } |
| 60 | |
| 61 | static void corgibl_blank(int blank) |
| 62 | { |
| 63 | switch(blank) { |
| 64 | |
| 65 | case FB_BLANK_NORMAL: |
| 66 | case FB_BLANK_VSYNC_SUSPEND: |
| 67 | case FB_BLANK_HSYNC_SUSPEND: |
| 68 | case FB_BLANK_POWERDOWN: |
| 69 | if (corgibl_powermode == FB_BLANK_UNBLANK) { |
| 70 | corgibl_send_intensity(0); |
| 71 | corgibl_powermode = blank; |
| 72 | } |
| 73 | break; |
| 74 | case FB_BLANK_UNBLANK: |
| 75 | if (corgibl_powermode != FB_BLANK_UNBLANK) { |
| 76 | corgibl_powermode = blank; |
| 77 | corgibl_send_intensity(current_intensity); |
| 78 | } |
| 79 | break; |
| 80 | } |
| 81 | } |
| 82 | |
| 83 | #ifdef CONFIG_PM |
| 84 | static int corgibl_suspend(struct device *dev, u32 state, u32 level) |
| 85 | { |
| 86 | if (level == SUSPEND_POWER_DOWN) |
| 87 | corgibl_blank(FB_BLANK_POWERDOWN); |
| 88 | return 0; |
| 89 | } |
| 90 | |
| 91 | static int corgibl_resume(struct device *dev, u32 level) |
| 92 | { |
| 93 | if (level == RESUME_POWER_ON) |
| 94 | corgibl_blank(FB_BLANK_UNBLANK); |
| 95 | return 0; |
| 96 | } |
| 97 | #else |
| 98 | #define corgibl_suspend NULL |
| 99 | #define corgibl_resume NULL |
| 100 | #endif |
| 101 | |
| 102 | |
| 103 | static int corgibl_set_power(struct backlight_device *bd, int state) |
| 104 | { |
| 105 | corgibl_blank(state); |
| 106 | return 0; |
| 107 | } |
| 108 | |
| 109 | static int corgibl_get_power(struct backlight_device *bd) |
| 110 | { |
| 111 | return corgibl_powermode; |
| 112 | } |
| 113 | |
| 114 | static int corgibl_set_intensity(struct backlight_device *bd, int intensity) |
| 115 | { |
| 116 | if (intensity > CORGI_MAX_INTENSITY) |
| 117 | intensity = CORGI_MAX_INTENSITY; |
| 118 | corgibl_send_intensity(intensity); |
| 119 | current_intensity=intensity; |
| 120 | return 0; |
| 121 | } |
| 122 | |
| 123 | static int corgibl_get_intensity(struct backlight_device *bd) |
| 124 | { |
| 125 | return current_intensity; |
| 126 | } |
| 127 | |
| 128 | /* |
| 129 | * Called when the battery is low to limit the backlight intensity. |
| 130 | * If limit==0 clear any limit, otherwise limit the intensity |
| 131 | */ |
| 132 | void corgibl_limit_intensity(int limit) |
| 133 | { |
| 134 | corgibl_limit = (limit ? 1 : 0); |
| 135 | corgibl_send_intensity(current_intensity); |
| 136 | } |
| 137 | EXPORT_SYMBOL(corgibl_limit_intensity); |
| 138 | |
| 139 | |
| 140 | static struct backlight_properties corgibl_data = { |
| 141 | .owner = THIS_MODULE, |
| 142 | .get_power = corgibl_get_power, |
| 143 | .set_power = corgibl_set_power, |
| 144 | .max_brightness = CORGI_MAX_INTENSITY, |
| 145 | .get_brightness = corgibl_get_intensity, |
| 146 | .set_brightness = corgibl_set_intensity, |
| 147 | }; |
| 148 | |
| 149 | static struct backlight_device *corgi_backlight_device; |
| 150 | |
| 151 | static int __init corgibl_probe(struct device *dev) |
| 152 | { |
| 153 | corgi_backlight_device = backlight_device_register ("corgi-bl", |
| 154 | NULL, &corgibl_data); |
| 155 | if (IS_ERR (corgi_backlight_device)) |
| 156 | return PTR_ERR (corgi_backlight_device); |
| 157 | |
| 158 | corgibl_set_intensity(NULL, CORGI_DEFAULT_INTENSITY); |
| 159 | |
| 160 | printk("Corgi Backlight Driver Initialized.\n"); |
| 161 | return 0; |
| 162 | } |
| 163 | |
| 164 | static int corgibl_remove(struct device *dev) |
| 165 | { |
| 166 | backlight_device_unregister(corgi_backlight_device); |
| 167 | |
| 168 | corgibl_set_intensity(NULL, 0); |
| 169 | |
| 170 | printk("Corgi Backlight Driver Unloaded\n"); |
| 171 | return 0; |
| 172 | } |
| 173 | |
| 174 | static struct device_driver corgibl_driver = { |
| 175 | .name = "corgi-bl", |
| 176 | .bus = &platform_bus_type, |
| 177 | .probe = corgibl_probe, |
| 178 | .remove = corgibl_remove, |
| 179 | .suspend = corgibl_suspend, |
| 180 | .resume = corgibl_resume, |
| 181 | }; |
| 182 | |
| 183 | static int __init corgibl_init(void) |
| 184 | { |
| 185 | return driver_register(&corgibl_driver); |
| 186 | } |
| 187 | |
| 188 | static void __exit corgibl_exit(void) |
| 189 | { |
| 190 | driver_unregister(&corgibl_driver); |
| 191 | } |
| 192 | |
| 193 | module_init(corgibl_init); |
| 194 | module_exit(corgibl_exit); |
| 195 | |
| 196 | MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>"); |
| 197 | MODULE_DESCRIPTION("Corgi Backlight Driver"); |
| 198 | MODULE_LICENSE("GPLv2"); |