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 usleep_range(10000, 11000); 38 outb(KB3886_PWM0_WRITE, KB3886_IO); 39 usleep_range(10000, 11000); 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 const struct dmi_system_id kb3886bl_device_table[] __initconst = { 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_SLEEP 110 static int kb3886bl_suspend(struct device *dev) 111 { 112 struct backlight_device *bd = dev_get_drvdata(dev); 113 114 kb3886bl_flags |= KB3886BL_SUSPENDED; 115 backlight_update_status(bd); 116 return 0; 117 } 118 119 static int kb3886bl_resume(struct device *dev) 120 { 121 struct backlight_device *bd = dev_get_drvdata(dev); 122 123 kb3886bl_flags &= ~KB3886BL_SUSPENDED; 124 backlight_update_status(bd); 125 return 0; 126 } 127 #endif 128 129 static SIMPLE_DEV_PM_OPS(kb3886bl_pm_ops, kb3886bl_suspend, kb3886bl_resume); 130 131 static int kb3886bl_get_intensity(struct backlight_device *bd) 132 { 133 return kb3886bl_intensity; 134 } 135 136 static const struct backlight_ops kb3886bl_ops = { 137 .get_brightness = kb3886bl_get_intensity, 138 .update_status = kb3886bl_send_intensity, 139 }; 140 141 static int kb3886bl_probe(struct platform_device *pdev) 142 { 143 struct backlight_properties props; 144 struct kb3886bl_machinfo *machinfo = dev_get_platdata(&pdev->dev); 145 146 bl_machinfo = machinfo; 147 if (!machinfo->limit_mask) 148 machinfo->limit_mask = -1; 149 150 memset(&props, 0, sizeof(struct backlight_properties)); 151 props.type = BACKLIGHT_RAW; 152 props.max_brightness = machinfo->max_intensity; 153 kb3886_backlight_device = devm_backlight_device_register(&pdev->dev, 154 "kb3886-bl", &pdev->dev, 155 NULL, &kb3886bl_ops, 156 &props); 157 if (IS_ERR(kb3886_backlight_device)) 158 return PTR_ERR(kb3886_backlight_device); 159 160 platform_set_drvdata(pdev, kb3886_backlight_device); 161 162 kb3886_backlight_device->props.power = FB_BLANK_UNBLANK; 163 kb3886_backlight_device->props.brightness = machinfo->default_intensity; 164 backlight_update_status(kb3886_backlight_device); 165 166 return 0; 167 } 168 169 static struct platform_driver kb3886bl_driver = { 170 .probe = kb3886bl_probe, 171 .driver = { 172 .name = "kb3886-bl", 173 .pm = &kb3886bl_pm_ops, 174 }, 175 }; 176 177 static int __init kb3886_init(void) 178 { 179 if (!dmi_check_system(kb3886bl_device_table)) 180 return -ENODEV; 181 182 platform_add_devices(devices, ARRAY_SIZE(devices)); 183 return platform_driver_register(&kb3886bl_driver); 184 } 185 186 static void __exit kb3886_exit(void) 187 { 188 platform_driver_unregister(&kb3886bl_driver); 189 } 190 191 module_init(kb3886_init); 192 module_exit(kb3886_exit); 193 194 MODULE_AUTHOR("Claudio Nieder <private@claudio.ch>"); 195 MODULE_DESCRIPTION("Tabletkiosk Sahara Touch-iT Backlight Driver"); 196 MODULE_LICENSE("GPL"); 197 MODULE_ALIAS("dmi:*:svnSDV:pniTouchT201:*"); 198