drivers/platform/x86/samsung-q10.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  Driver for Samsung Q10 and related laptops: controls the backlight
   4  *
   5  *  Copyright (c) 2011 Frederick van der Wyck <fvanderwyck@gmail.com>
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/kernel.h>
  10 #include <linux/init.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/backlight.h>
  13 #include <linux/dmi.h>
  14 #include <linux/acpi.h>
  15
  16 #define SAMSUNGQ10_BL_MAX_INTENSITY 7
  17
  18 static acpi_handle ec_handle;
  19
  20 static bool force;
  21 module_param(force, bool, 0);
  22 MODULE_PARM_DESC(force,
  23                 "Disable the DMI check and force the driver to be loaded");
  24
  25 static int samsungq10_bl_set_intensity(struct backlight_device *bd)
  26 {
  27
  28         acpi_status status;
  29         int i;
  30
  31         for (i = 0; i < SAMSUNGQ10_BL_MAX_INTENSITY; i++) {
  32                 status = acpi_evaluate_object(ec_handle, "_Q63", NULL, NULL);
  33                 if (ACPI_FAILURE(status))
  34                         return -EIO;
  35         }
  36         for (i = 0; i < bd->props.brightness; i++) {
  37                 status = acpi_evaluate_object(ec_handle, "_Q64", NULL, NULL);
  38                 if (ACPI_FAILURE(status))
  39                         return -EIO;
  40         }
  41
  42         return 0;
  43 }
  44
  45 static const struct backlight_ops samsungq10_bl_ops = {
  46         .update_status  = samsungq10_bl_set_intensity,
  47 };
  48
  49 static int samsungq10_probe(struct platform_device *pdev)
  50 {
  51
  52         struct backlight_properties props;
  53         struct backlight_device *bd;
  54
  55         memset(&props, 0, sizeof(struct backlight_properties));
  56         props.type = BACKLIGHT_PLATFORM;
  57         props.max_brightness = SAMSUNGQ10_BL_MAX_INTENSITY;
  58         bd = backlight_device_register("samsung", &pdev->dev, NULL,
  59                                        &samsungq10_bl_ops, &props);
  60         if (IS_ERR(bd))
  61                 return PTR_ERR(bd);
  62
  63         platform_set_drvdata(pdev, bd);
  64
  65         return 0;
  66 }
  67
  68 static int samsungq10_remove(struct platform_device *pdev)
  69 {
  70
  71         struct backlight_device *bd = platform_get_drvdata(pdev);
  72
  73         backlight_device_unregister(bd);
  74
  75         return 0;
  76 }
  77
  78 static struct platform_driver samsungq10_driver = {
  79         .driver         = {
  80                 .name   = KBUILD_MODNAME,
  81         },
  82         .probe          = samsungq10_probe,
  83         .remove         = samsungq10_remove,
  84 };
  85
  86 static struct platform_device *samsungq10_device;
  87
  88 static int __init dmi_check_callback(const struct dmi_system_id *id)
  89 {
  90         printk(KERN_INFO KBUILD_MODNAME ": found model '%s'\n", id->ident);
  91         return 1;
  92 }
  93
  94 static const struct dmi_system_id samsungq10_dmi_table[] __initconst = {
  95         {
  96                 .ident = "Samsung Q10",
  97                 .matches = {
  98                         DMI_MATCH(DMI_SYS_VENDOR, "Samsung"),
  99                         DMI_MATCH(DMI_PRODUCT_NAME, "SQ10"),
 100                 },
 101                 .callback = dmi_check_callback,
 102         },
 103         {
 104                 .ident = "Samsung Q20",
 105                 .matches = {
 106                         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG Electronics"),
 107                         DMI_MATCH(DMI_PRODUCT_NAME, "SENS Q20"),
 108                 },
 109                 .callback = dmi_check_callback,
 110         },
 111         {
 112                 .ident = "Samsung Q25",
 113                 .matches = {
 114                         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG Electronics"),
 115                         DMI_MATCH(DMI_PRODUCT_NAME, "NQ25"),
 116                 },
 117                 .callback = dmi_check_callback,
 118         },
 119         {
 120                 .ident = "Dell Latitude X200",
 121                 .matches = {
 122                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 123                         DMI_MATCH(DMI_PRODUCT_NAME, "X200"),
 124                 },
 125                 .callback = dmi_check_callback,
 126         },
 127         { },
 128 };
 129 MODULE_DEVICE_TABLE(dmi, samsungq10_dmi_table);
 130
 131 static int __init samsungq10_init(void)
 132 {
 133         if (!force && !dmi_check_system(samsungq10_dmi_table))
 134                 return -ENODEV;
 135
 136         ec_handle = ec_get_handle();
 137
 138         if (!ec_handle)
 139                 return -ENODEV;
 140
 141         samsungq10_device = platform_create_bundle(&samsungq10_driver,
 142                                                    samsungq10_probe,
 143                                                    NULL, 0, NULL, 0);
 144
 145         return PTR_ERR_OR_ZERO(samsungq10_device);
 146 }
 147
 148 static void __exit samsungq10_exit(void)
 149 {
 150         platform_device_unregister(samsungq10_device);
 151         platform_driver_unregister(&samsungq10_driver);
 152 }
 153
 154 module_init(samsungq10_init);
 155 module_exit(samsungq10_exit);
 156
 157 MODULE_AUTHOR("Frederick van der Wyck <fvanderwyck@gmail.com>");
 158 MODULE_DESCRIPTION("Samsung Q10 Driver");
 159 MODULE_LICENSE("GPL");