1 /* 2 * Backlight Driver for the KB3886 Backlight 3 * 4 * Copyright (c) 2007-2008 Claudio Nieder 5 * 6 * Based on corgi_bl.c by Richard Purdie and kb3886 driver by Robert Woerle 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/platform_device.h> 18 #include <linux/mutex.h> 19 #include <linux/fb.h> 20 #include <linux/backlight.h> 21 #include <linux/delay.h> 22 #include <linux/dmi.h> 23 24 #define KB3886_PARENT 0x64 25 #define KB3886_IO 0x60 26 #define KB3886_ADC_DAC_PWM 0xC4 27 #define KB3886_PWM0_WRITE 0x81 28 #define KB3886_PWM0_READ 0x41 29 30 static DEFINE_MUTEX(bl_mutex); 31 32 static void kb3886_bl_set_intensity(int intensity) 33 { 34 mutex_lock(&bl_mutex); 35 intensity = intensity&0xff; 36 outb(KB3886_ADC_DAC_PWM, KB3886_PARENT); 37 msleep(10); 38 outb(KB3886_PWM0_WRITE, KB3886_IO); 39 msleep(10); 40 outb(intensity, KB3886_IO); 41 mutex_unlock(&bl_mutex); 42 } 43 44 struct kb3886bl_machinfo { 45 int max_intensity; 46 int default_intensity; 47 int limit_mask; 48 void (*set_bl_intensity)(int intensity); 49 }; 50 51 static struct kb3886bl_machinfo kb3886_bl_machinfo = { 52 .max_intensity = 0xff, 53 .default_intensity = 0xa0, 54 .limit_mask = 0x7f, 55 .set_bl_intensity = kb3886_bl_set_intensity, 56 }; 57 58 static struct platform_device kb3886bl_device = { 59 .name = "kb3886-bl", 60 .dev = { 61 .platform_data = &kb3886_bl_machinfo, 62 }, 63 .id = -1, 64 }; 65 66 static struct platform_device *devices[] __initdata = { 67 &kb3886bl_device, 68 }; 69 70 /* 71 * Back to driver 72 */ 73 74 static int kb3886bl_intensity; 75 static struct backlight_device *kb3886_backlight_device; 76 static struct kb3886bl_machinfo *bl_machinfo; 77 78 static unsigned long kb3886bl_flags; 79 #define KB3886BL_SUSPENDED 0x01 80 81 static struct dmi_system_id __initdata kb3886bl_device_table[] = { 82 { 83 .ident = "Sahara Touch-iT", 84 .matches = { 85 DMI_MATCH(DMI_SYS_VENDOR, "SDV"), 86 DMI_MATCH(DMI_PRODUCT_NAME, "iTouch T201"), 87 }, 88 }, 89 { } 90 }; 91 92 static int kb3886bl_send_intensity(struct backlight_device *bd) 93 { 94 int intensity = bd->props.brightness; 95 96 if (bd->props.power != FB_BLANK_UNBLANK) 97 intensity = 0; 98 if (bd->props.fb_blank != FB_BLANK_UNBLANK) 99 intensity = 0; 100 if (kb3886bl_flags & KB3886BL_SUSPENDED) 101 intensity = 0; 102 103 bl_machinfo->set_bl_intensity(intensity); 104 105 kb3886bl_intensity = intensity; 106 return 0; 107 } 108 109 #ifdef CONFIG_PM 110 static int kb3886bl_suspend(struct platform_device *pdev, pm_message_t state) 111 { 112 struct backlight_device *bd = platform_get_drvdata(pdev); 113 114 kb3886bl_flags |= KB3886BL_SUSPENDED; 115 backlight_update_status(bd); 116 return 0; 117 } 118 119 static int kb3886bl_resume(struct platform_device *pdev) 120 { 121 struct backlight_device *bd = platform_get_drvdata(pdev); 122 123 kb3886bl_flags &= ~KB3886BL_SUSPENDED; 124 backlight_update_status(bd); 125 return 0; 126 } 127 #else 128 #define kb3886bl_suspend NULL 129 #define kb3886bl_resume NULL 130 #endif 131 132 static int kb3886bl_get_intensity(struct backlight_device *bd) 133 { 134 return kb3886bl_intensity; 135 } 136 137 static struct backlight_ops kb3886bl_ops = { 138 .get_brightness = kb3886bl_get_intensity, 139 .update_status = kb3886bl_send_intensity, 140 }; 141 142 static int kb3886bl_probe(struct platform_device *pdev) 143 { 144 struct kb3886bl_machinfo *machinfo = pdev->dev.platform_data; 145 146 bl_machinfo = machinfo; 147 if (!machinfo->limit_mask) 148 machinfo->limit_mask = -1; 149 150 kb3886_backlight_device = backlight_device_register("kb3886-bl", 151 &pdev->dev, NULL, &kb3886bl_ops); 152 if (IS_ERR(kb3886_backlight_device)) 153 return PTR_ERR(kb3886_backlight_device); 154 155 platform_set_drvdata(pdev, kb3886_backlight_device); 156 157 kb3886_backlight_device->props.max_brightness = machinfo->max_intensity; 158 kb3886_backlight_device->props.power = FB_BLANK_UNBLANK; 159 kb3886_backlight_device->props.brightness = machinfo->default_intensity; 160 backlight_update_status(kb3886_backlight_device); 161 162 return 0; 163 } 164 165 static int kb3886bl_remove(struct platform_device *pdev) 166 { 167 struct backlight_device *bd = platform_get_drvdata(pdev); 168 169 backlight_device_unregister(bd); 170 171 return 0; 172 } 173 174 static struct platform_driver kb3886bl_driver = { 175 .probe = kb3886bl_probe, 176 .remove = kb3886bl_remove, 177 .suspend = kb3886bl_suspend, 178 .resume = kb3886bl_resume, 179 .driver = { 180 .name = "kb3886-bl", 181 }, 182 }; 183 184 static int __init kb3886_init(void) 185 { 186 if (!dmi_check_system(kb3886bl_device_table)) 187 return -ENODEV; 188 189 platform_add_devices(devices, ARRAY_SIZE(devices)); 190 return platform_driver_register(&kb3886bl_driver); 191 } 192 193 static void __exit kb3886_exit(void) 194 { 195 platform_driver_unregister(&kb3886bl_driver); 196 } 197 198 module_init(kb3886_init); 199 module_exit(kb3886_exit); 200 201 MODULE_AUTHOR("Claudio Nieder <private@claudio.ch>"); 202 MODULE_DESCRIPTION("Tabletkiosk Sahara Touch-iT Backlight Driver"); 203 MODULE_LICENSE("GPL"); 204 MODULE_ALIAS("dmi:*:svnSDV:pniTouchT201:*"); 205