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