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 <acpi/acpi_drivers.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 int samsungq10_bl_get_intensity(struct backlight_device *bd)
  50 {
  51         return bd->props.brightness;
  52 }
  53
  54 static const struct backlight_ops samsungq10_bl_ops = {
  55         .get_brightness = samsungq10_bl_get_intensity,
  56         .update_status  = samsungq10_bl_set_intensity,
  57 };
  58
  59 static int samsungq10_probe(struct platform_device *pdev)
  60 {
  61
  62         struct backlight_properties props;
  63         struct backlight_device *bd;
  64
  65         memset(&props, 0, sizeof(struct backlight_properties));
  66         props.type = BACKLIGHT_PLATFORM;
  67         props.max_brightness = SAMSUNGQ10_BL_MAX_INTENSITY;
  68         bd = backlight_device_register("samsung", &pdev->dev, NULL,
  69                                        &samsungq10_bl_ops, &props);
  70         if (IS_ERR(bd))
  71                 return PTR_ERR(bd);
  72
  73         platform_set_drvdata(pdev, bd);
  74
  75         return 0;
  76 }
  77
  78 static int samsungq10_remove(struct platform_device *pdev)
  79 {
  80
  81         struct backlight_device *bd = platform_get_drvdata(pdev);
  82
  83         backlight_device_unregister(bd);
  84
  85         return 0;
  86 }
  87
  88 static struct platform_driver samsungq10_driver = {
  89         .driver         = {
  90                 .name   = KBUILD_MODNAME,
  91                 .owner  = THIS_MODULE,
  92         },
  93         .probe          = samsungq10_probe,
  94         .remove         = samsungq10_remove,
  95 };
  96
  97 static struct platform_device *samsungq10_device;
  98
  99 static int __init dmi_check_callback(const struct dmi_system_id *id)
 100 {
 101         printk(KERN_INFO KBUILD_MODNAME ": found model '%s'\n", id->ident);
 102         return 1;
 103 }
 104
 105 static struct dmi_system_id __initdata samsungq10_dmi_table[] = {
 106         {
 107                 .ident = "Samsung Q10",
 108                 .matches = {
 109                         DMI_MATCH(DMI_SYS_VENDOR, "Samsung"),
 110                         DMI_MATCH(DMI_PRODUCT_NAME, "SQ10"),
 111                 },
 112                 .callback = dmi_check_callback,
 113         },
 114         {
 115                 .ident = "Samsung Q20",
 116                 .matches = {
 117                         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG Electronics"),
 118                         DMI_MATCH(DMI_PRODUCT_NAME, "SENS Q20"),
 119                 },
 120                 .callback = dmi_check_callback,
 121         },
 122         {
 123                 .ident = "Samsung Q25",
 124                 .matches = {
 125                         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG Electronics"),
 126                         DMI_MATCH(DMI_PRODUCT_NAME, "NQ25"),
 127                 },
 128                 .callback = dmi_check_callback,
 129         },
 130         {
 131                 .ident = "Dell Latitude X200",
 132                 .matches = {
 133                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 134                         DMI_MATCH(DMI_PRODUCT_NAME, "X200"),
 135                 },
 136                 .callback = dmi_check_callback,
 137         },
 138         { },
 139 };
 140 MODULE_DEVICE_TABLE(dmi, samsungq10_dmi_table);
 141
 142 static int __init samsungq10_init(void)
 143 {
 144         if (!force && !dmi_check_system(samsungq10_dmi_table))
 145                 return -ENODEV;
 146
 147         ec_handle = ec_get_handle();
 148
 149         if (!ec_handle)
 150                 return -ENODEV;
 151
 152         samsungq10_device = platform_create_bundle(&samsungq10_driver,
 153                                                    samsungq10_probe,
 154                                                    NULL, 0, NULL, 0);
 155
 156         return PTR_ERR_OR_ZERO(samsungq10_device);
 157 }
 158
 159 static void __exit samsungq10_exit(void)
 160 {
 161         platform_device_unregister(samsungq10_device);
 162         platform_driver_unregister(&samsungq10_driver);
 163 }
 164
 165 module_init(samsungq10_init);
 166 module_exit(samsungq10_exit);
 167
 168 MODULE_AUTHOR("Frederick van der Wyck <fvanderwyck@gmail.com>");
 169 MODULE_DESCRIPTION("Samsung Q10 Driver");
 170 MODULE_LICENSE("GPL");