linux/drivers/platform/x86/samsung-q10.c
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   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
  22static acpi_handle ec_handle;
  23
  24static bool force;
  25module_param(force, bool, 0);
  26MODULE_PARM_DESC(force,
  27                "Disable the DMI check and force the driver to be loaded");
  28
  29static 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
  49static const struct backlight_ops samsungq10_bl_ops = {
  50        .update_status  = samsungq10_bl_set_intensity,
  51};
  52
  53static 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
  72static 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
  82static struct platform_driver samsungq10_driver = {
  83        .driver         = {
  84                .name   = KBUILD_MODNAME,
  85        },
  86        .probe          = samsungq10_probe,
  87        .remove         = samsungq10_remove,
  88};
  89
  90static struct platform_device *samsungq10_device;
  91
  92static 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
  98static 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};
 133MODULE_DEVICE_TABLE(dmi, samsungq10_dmi_table);
 134
 135static 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
 152static void __exit samsungq10_exit(void)
 153{
 154        platform_device_unregister(samsungq10_device);
 155        platform_driver_unregister(&samsungq10_driver);
 156}
 157
 158module_init(samsungq10_init);
 159module_exit(samsungq10_exit);
 160
 161MODULE_AUTHOR("Frederick van der Wyck <fvanderwyck@gmail.com>");
 162MODULE_DESCRIPTION("Samsung Q10 Driver");
 163MODULE_LICENSE("GPL");
 164