drivers/platform/x86/samsung-q10.c

   1 /*
   2  *  Driver for Samsung Q10 and related laptops: controls the backlight
   3  *
   4  *  Copyright (c) 2011 Frederick van der Wyck <fvanderwyck@gmail.com>
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License version 2 as
   8  *  published by the Free Software Foundation.
   9  *
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/kernel.h>
  14 #include <linux/init.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/backlight.h>
  17 #include <linux/i8042.h>
  18 #include <linux/dmi.h>
  19
  20 #define SAMSUNGQ10_BL_MAX_INTENSITY      255
  21 #define SAMSUNGQ10_BL_DEFAULT_INTENSITY  185
  22
  23 #define SAMSUNGQ10_BL_8042_CMD           0xbe
  24 #define SAMSUNGQ10_BL_8042_DATA          { 0x89, 0x91 }
  25
  26 static int samsungq10_bl_brightness;
  27
  28 static bool force;
  29 module_param(force, bool, 0);
  30 MODULE_PARM_DESC(force,
  31                 "Disable the DMI check and force the driver to be loaded");
  32
  33 static int samsungq10_bl_set_intensity(struct backlight_device *bd)
  34 {
  35
  36         int brightness = bd->props.brightness;
  37         unsigned char c[3] = SAMSUNGQ10_BL_8042_DATA;
  38
  39         c[2] = (unsigned char)brightness;
  40         i8042_lock_chip();
  41         i8042_command(c, (0x30 << 8) | SAMSUNGQ10_BL_8042_CMD);
  42         i8042_unlock_chip();
  43         samsungq10_bl_brightness = brightness;
  44
  45         return 0;
  46 }
  47
  48 static int samsungq10_bl_get_intensity(struct backlight_device *bd)
  49 {
  50         return samsungq10_bl_brightness;
  51 }
  52
  53 static const struct backlight_ops samsungq10_bl_ops = {
  54         .get_brightness = samsungq10_bl_get_intensity,
  55         .update_status  = samsungq10_bl_set_intensity,
  56 };
  57
  58 #ifdef CONFIG_PM_SLEEP
  59 static int samsungq10_suspend(struct device *dev)
  60 {
  61         return 0;
  62 }
  63
  64 static int samsungq10_resume(struct device *dev)
  65 {
  66
  67         struct backlight_device *bd = dev_get_drvdata(dev);
  68
  69         samsungq10_bl_set_intensity(bd);
  70         return 0;
  71 }
  72 #else
  73 #define samsungq10_suspend NULL
  74 #define samsungq10_resume  NULL
  75 #endif
  76
  77 static SIMPLE_DEV_PM_OPS(samsungq10_pm_ops,
  78                           samsungq10_suspend, samsungq10_resume);
  79
  80 static int samsungq10_probe(struct platform_device *pdev)
  81 {
  82
  83         struct backlight_properties props;
  84         struct backlight_device *bd;
  85
  86         memset(&props, 0, sizeof(struct backlight_properties));
  87         props.type = BACKLIGHT_PLATFORM;
  88         props.max_brightness = SAMSUNGQ10_BL_MAX_INTENSITY;
  89         bd = backlight_device_register("samsung", &pdev->dev, NULL,
  90                                        &samsungq10_bl_ops, &props);
  91         if (IS_ERR(bd))
  92                 return PTR_ERR(bd);
  93
  94         platform_set_drvdata(pdev, bd);
  95
  96         bd->props.brightness = SAMSUNGQ10_BL_DEFAULT_INTENSITY;
  97         samsungq10_bl_set_intensity(bd);
  98
  99         return 0;
 100 }
 101
 102 static int samsungq10_remove(struct platform_device *pdev)
 103 {
 104
 105         struct backlight_device *bd = platform_get_drvdata(pdev);
 106
 107         bd->props.brightness = SAMSUNGQ10_BL_DEFAULT_INTENSITY;
 108         samsungq10_bl_set_intensity(bd);
 109
 110         backlight_device_unregister(bd);
 111
 112         return 0;
 113 }
 114
 115 static struct platform_driver samsungq10_driver = {
 116         .driver         = {
 117                 .name   = KBUILD_MODNAME,
 118                 .owner  = THIS_MODULE,
 119                 .pm     = &samsungq10_pm_ops,
 120         },
 121         .probe          = samsungq10_probe,
 122         .remove         = samsungq10_remove,
 123 };
 124
 125 static struct platform_device *samsungq10_device;
 126
 127 static int __init dmi_check_callback(const struct dmi_system_id *id)
 128 {
 129         printk(KERN_INFO KBUILD_MODNAME ": found model '%s'\n", id->ident);
 130         return 1;
 131 }
 132
 133 static struct dmi_system_id __initdata samsungq10_dmi_table[] = {
 134         {
 135                 .ident = "Samsung Q10",
 136                 .matches = {
 137                         DMI_MATCH(DMI_SYS_VENDOR, "Samsung"),
 138                         DMI_MATCH(DMI_PRODUCT_NAME, "SQ10"),
 139                 },
 140                 .callback = dmi_check_callback,
 141         },
 142         {
 143                 .ident = "Samsung Q20",
 144                 .matches = {
 145                         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG Electronics"),
 146                         DMI_MATCH(DMI_PRODUCT_NAME, "SENS Q20"),
 147                 },
 148                 .callback = dmi_check_callback,
 149         },
 150         {
 151                 .ident = "Samsung Q25",
 152                 .matches = {
 153                         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG Electronics"),
 154                         DMI_MATCH(DMI_PRODUCT_NAME, "NQ25"),
 155                 },
 156                 .callback = dmi_check_callback,
 157         },
 158         {
 159                 .ident = "Dell Latitude X200",
 160                 .matches = {
 161                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 162                         DMI_MATCH(DMI_PRODUCT_NAME, "X200"),
 163                 },
 164                 .callback = dmi_check_callback,
 165         },
 166         { },
 167 };
 168 MODULE_DEVICE_TABLE(dmi, samsungq10_dmi_table);
 169
 170 static int __init samsungq10_init(void)
 171 {
 172         if (!force && !dmi_check_system(samsungq10_dmi_table))
 173                 return -ENODEV;
 174
 175         samsungq10_device = platform_create_bundle(&samsungq10_driver,
 176                                                    samsungq10_probe,
 177                                                    NULL, 0, NULL, 0);
 178
 179         return PTR_RET(samsungq10_device);
 180 }
 181
 182 static void __exit samsungq10_exit(void)
 183 {
 184         platform_device_unregister(samsungq10_device);
 185         platform_driver_unregister(&samsungq10_driver);
 186 }
 187
 188 module_init(samsungq10_init);
 189 module_exit(samsungq10_exit);
 190
 191 MODULE_AUTHOR("Frederick van der Wyck <fvanderwyck@gmail.com>");
 192 MODULE_DESCRIPTION("Samsung Q10 Driver");
 193 MODULE_LICENSE("GPL");