/*
* Driver for Samsung Q10 and related laptops: controls the backlight
*
* Copyright (c) 2011 Frederick van der Wyck <fvanderwyck@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/backlight.h>
#include <linux/i8042.h>
#include <linux/dmi.h>
#define SAMSUNGQ10_BL_MAX_INTENSITY 255
#define SAMSUNGQ10_BL_DEFAULT_INTENSITY 185
#define SAMSUNGQ10_BL_8042_CMD 0xbe
#define SAMSUNGQ10_BL_8042_DATA { 0x89, 0x91 }
static int samsungq10_bl_brightness;
static bool force;
module_param(force, bool, 0);
MODULE_PARM_DESC(force,
"Disable the DMI check and force the driver to be loaded");
static int samsungq10_bl_set_intensity(struct backlight_device *bd)
{
int brightness = bd->props.brightness;
unsigned char c[3] = SAMSUNGQ10_BL_8042_DATA;
c[2] = (unsigned char)brightness;
i8042_lock_chip();
i8042_command(c, (0x30 << 8) | SAMSUNGQ10_BL_8042_CMD);
i8042_unlock_chip();
samsungq10_bl_brightness = brightness;
return 0;
}
static int samsungq10_bl_get_intensity(struct backlight_device *bd)
{
return samsungq10_bl_brightness;
}
static const struct backlight_ops samsungq10_bl_ops = {
.get_brightness = samsungq10_bl_get_intensity,
.update_status = samsungq10_bl_set_intensity,
};
#ifdef CONFIG_PM_SLEEP
static int samsungq10_suspend(struct device *dev)
{
return 0;
}
static int samsungq10_resume(struct device *dev)
{
struct backlight_device *bd = dev_get_drvdata(dev);
samsungq10_bl_set_intensity(bd);
return 0;
}
#else
#define samsungq10_suspend NULL
#define samsungq10_resume NULL
#endif
static SIMPLE_DEV_PM_OPS(samsungq10_pm_ops,
samsungq10_suspend, samsungq10_resume);
static int __devinit samsungq10_probe(struct platform_device *pdev)
{
struct backlight_properties props;
struct backlight_device *bd;
memset(&props, 0, sizeof(struct backlight_properties));
props.type = BACKLIGHT_PLATFORM;
props.max_brightness = SAMSUNGQ10_BL_MAX_INTENSITY;
bd = backlight_device_register("samsung", &pdev->dev, NULL,
&samsungq10_bl_ops, &props);
if (IS_ERR(bd))
return PTR_ERR(bd);
platform_set_drvdata(pdev, bd);
bd->props.brightness = SAMSUNGQ10_BL_DEFAULT_INTENSITY;
samsungq10_bl_set_intensity(bd);
return 0;
}
static int __devexit samsungq10_remove(struct platform_device *pdev)
{
struct backlight_device *bd = platform_get_drvdata(pdev);
bd->props.brightness = SAMSUNGQ10_BL_DEFAULT_INTENSITY;
samsungq10_bl_set_intensity(bd);
backlight_device_unregister(bd);
return 0;
}
static struct platform_driver samsungq10_driver = {
.driver = {
.name = KBUILD_MODNAME,
.owner = THIS_MODULE,
.pm = &samsungq10_pm_ops,
},
.probe = samsungq10_probe,
.remove = __devexit_p(samsungq10_remove),
};
static struct platform_device *samsungq10_device;
static int __init dmi_check_callback(const struct dmi_system_id *id)
{
printk(KERN_INFO KBUILD_MODNAME ": found model '%s'\n", id->ident);
return 0;
}
static struct dmi_system_id __initdata samsungq10_dmi_table[] = {
{
.ident = "Samsung Q10",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Samsung"),
DMI_MATCH(DMI_PRODUCT_NAME, "SQ10"),
},
.callback = dmi_check_callback,
},
{
.ident = "Samsung Q20",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG Electronics"),
DMI_MATCH(DMI_PRODUCT_NAME, "SENS Q20"),
},
.callback = dmi_check_callback,
},
{
.ident = "Samsung Q25",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG Electronics"),
DMI_MATCH(DMI_PRODUCT_NAME, "NQ25"),
},
.callback = dmi_check_callback,
},
{
.ident = "Dell Latitude X200",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
DMI_MATCH(DMI_PRODUCT_NAME, "X200"),
},
.callback = dmi_check_callback,
},
{ },
};
MODULE_DEVICE_TABLE(dmi, samsungq10_dmi_table);
static int __init samsungq10_init(void)
{
if (!force && !dmi_check_system(samsungq10_dmi_table))
return -ENODEV;
samsungq10_device = platform_create_bundle(&samsungq10_driver,
samsungq10_probe,
NULL, 0, NULL, 0);
if (IS_ERR(samsungq10_device))
return PTR_ERR(samsungq10_device);
return 0;
}
static void __exit samsungq10_exit(void)
{
platform_device_unregister(samsungq10_device);
platform_driver_unregister(&samsungq10_driver);
}
module_init(samsungq10_init);
module_exit(samsungq10_exit);
MODULE_AUTHOR("Frederick van der Wyck <fvanderwyck@gmail.com>");
MODULE_DESCRIPTION("Samsung Q10 Driver");
MODULE_LICENSE("GPL");
