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/dmi.h>
  18 #include <linux/acpi.h>
  19
  20 #define SAMSUNGQ10_BL_MAX_INTENSITY 7
  21
  22 static acpi_handle ec_handle;
  23
  24 static bool force;
  25 module_param(force, bool, 0);
  26 MODULE_PARM_DESC(force,
  27                 "Disable the DMI check and force the driver to be loaded");
  28
  29 static int samsungq10_bl_set_intensity(struct backlight_device *bd)
  30 {
  31
  32         acpi_status status;
  33         int i;
  34
  35         for (i = 0; i < SAMSUNGQ10_BL_MAX_INTENSITY; i++) {
  36                 status = acpi_evaluate_object(ec_handle, "_Q63", NULL, NULL);
  37                 if (ACPI_FAILURE(status))
  38                         return -EIO;
  39         }
  40         for (i = 0; i < bd->props.brightness; i++) {
  41                 status = acpi_evaluate_object(ec_handle, "_Q64", NULL, NULL);
  42                 if (ACPI_FAILURE(status))
  43                         return -EIO;
  44         }
  45
  46         return 0;
  47 }
  48
  49 static const struct backlight_ops samsungq10_bl_ops = {
  50         .update_status  = samsungq10_bl_set_intensity,
  51 };
  52
  53 static int samsungq10_probe(struct platform_device *pdev)
  54 {
  55
  56         struct backlight_properties props;
  57         struct backlight_device *bd;
  58
  59         memset(&props, 0, sizeof(struct backlight_properties));
  60         props.type = BACKLIGHT_PLATFORM;
  61         props.max_brightness = SAMSUNGQ10_BL_MAX_INTENSITY;
  62         bd = backlight_device_register("samsung", &pdev->dev, NULL,
  63                                        &samsungq10_bl_ops, &props);
  64         if (IS_ERR(bd))
  65                 return PTR_ERR(bd);
  66
  67         platform_set_drvdata(pdev, bd);
  68
  69         return 0;
  70 }
  71
  72 static int samsungq10_remove(struct platform_device *pdev)
  73 {
  74
  75         struct backlight_device *bd = platform_get_drvdata(pdev);
  76
  77         backlight_device_unregister(bd);
  78
  79         return 0;
  80 }
  81
  82 static struct platform_driver samsungq10_driver = {
  83         .driver         = {
  84                 .name   = KBUILD_MODNAME,
  85         },
  86         .probe          = samsungq10_probe,
  87         .remove         = samsungq10_remove,
  88 };
  89
  90 static struct platform_device *samsungq10_device;
  91
  92 static int __init dmi_check_callback(const struct dmi_system_id *id)
  93 {
  94         printk(KERN_INFO KBUILD_MODNAME ": found model '%s'\n", id->ident);
  95         return 1;
  96 }
  97
  98 static struct dmi_system_id __initdata samsungq10_dmi_table[] = {
  99         {
 100                 .ident = "Samsung Q10",
 101                 .matches = {
 102                         DMI_MATCH(DMI_SYS_VENDOR, "Samsung"),
 103                         DMI_MATCH(DMI_PRODUCT_NAME, "SQ10"),
 104                 },
 105                 .callback = dmi_check_callback,
 106         },
 107         {
 108                 .ident = "Samsung Q20",
 109                 .matches = {
 110                         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG Electronics"),
 111                         DMI_MATCH(DMI_PRODUCT_NAME, "SENS Q20"),
 112                 },
 113                 .callback = dmi_check_callback,
 114         },
 115         {
 116                 .ident = "Samsung Q25",
 117                 .matches = {
 118                         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG Electronics"),
 119                         DMI_MATCH(DMI_PRODUCT_NAME, "NQ25"),
 120                 },
 121                 .callback = dmi_check_callback,
 122         },
 123         {
 124                 .ident = "Dell Latitude X200",
 125                 .matches = {
 126                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 127                         DMI_MATCH(DMI_PRODUCT_NAME, "X200"),
 128                 },
 129                 .callback = dmi_check_callback,
 130         },
 131         { },
 132 };
 133 MODULE_DEVICE_TABLE(dmi, samsungq10_dmi_table);
 134
 135 static int __init samsungq10_init(void)
 136 {
 137         if (!force && !dmi_check_system(samsungq10_dmi_table))
 138                 return -ENODEV;
 139
 140         ec_handle = ec_get_handle();
 141
 142         if (!ec_handle)
 143                 return -ENODEV;
 144
 145         samsungq10_device = platform_create_bundle(&samsungq10_driver,
 146                                                    samsungq10_probe,
 147                                                    NULL, 0, NULL, 0);
 148
 149         return PTR_ERR_OR_ZERO(samsungq10_device);
 150 }
 151
 152 static void __exit samsungq10_exit(void)
 153 {
 154         platform_device_unregister(samsungq10_device);
 155         platform_driver_unregister(&samsungq10_driver);
 156 }
 157
 158 module_init(samsungq10_init);
 159 module_exit(samsungq10_exit);
 160
 161 MODULE_AUTHOR("Frederick van der Wyck <fvanderwyck@gmail.com>");
 162 MODULE_DESCRIPTION("Samsung Q10 Driver");
 163 MODULE_LICENSE("GPL");