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 <acpi/acpi_drivers.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 int samsungq10_bl_get_intensity(struct backlight_device *bd)
  50{
  51        return bd->props.brightness;
  52}
  53
  54static const struct backlight_ops samsungq10_bl_ops = {
  55        .get_brightness = samsungq10_bl_get_intensity,
  56        .update_status  = samsungq10_bl_set_intensity,
  57};
  58
  59static 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
  78static 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
  88static 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
  97static struct platform_device *samsungq10_device;
  98
  99static 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
 105static 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};
 140MODULE_DEVICE_TABLE(dmi, samsungq10_dmi_table);
 141
 142static 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
 159static void __exit samsungq10_exit(void)
 160{
 161        platform_device_unregister(samsungq10_device);
 162        platform_driver_unregister(&samsungq10_driver);
 163}
 164
 165module_init(samsungq10_init);
 166module_exit(samsungq10_exit);
 167
 168MODULE_AUTHOR("Frederick van der Wyck <fvanderwyck@gmail.com>");
 169MODULE_DESCRIPTION("Samsung Q10 Driver");
 170MODULE_LICENSE("GPL");
 171