121 lines
3.4 KiB
C
121 lines
3.4 KiB
C
/*
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* leds-chromeos-keyboard.c - Keyboard backlight LED driver for Chrome OS.
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*
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* Copyright (C) 2012 Google, Inc.
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*
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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 as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#include <linux/acpi.h>
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#include <linux/leds.h>
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#include <linux/delay.h>
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#include <linux/err.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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/* Keyboard LED ACPI Device must be defined in firmware */
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#define ACPI_KEYBOARD_BACKLIGHT_DEVICE "\\_SB.KBLT"
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#define ACPI_KEYBOARD_BACKLIGHT_READ ACPI_KEYBOARD_BACKLIGHT_DEVICE ".KBQC"
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#define ACPI_KEYBOARD_BACKLIGHT_WRITE ACPI_KEYBOARD_BACKLIGHT_DEVICE ".KBCM"
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#define ACPI_KEYBOARD_BACKLIGHT_MAX 100
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static void keyboard_led_set_brightness(struct led_classdev *cdev,
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enum led_brightness brightness)
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{
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union acpi_object param;
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struct acpi_object_list input;
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acpi_status status;
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if (!(cdev->flags & LED_SUSPENDED))
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cdev->brightness = brightness;
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param.type = ACPI_TYPE_INTEGER;
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param.integer.value = brightness;
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input.count = 1;
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input.pointer = ¶m;
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status = acpi_evaluate_object(NULL, ACPI_KEYBOARD_BACKLIGHT_WRITE,
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&input, NULL);
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if (ACPI_FAILURE(status))
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dev_err(cdev->dev, "Error setting keyboard LED value");
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}
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static int keyboard_led_probe(struct platform_device *pdev)
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{
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struct led_classdev *cdev;
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acpi_handle handle;
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acpi_status status;
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int ret;
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/* Look for the keyboard LED ACPI Device */
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status = acpi_get_handle(ACPI_ROOT_OBJECT,
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ACPI_KEYBOARD_BACKLIGHT_DEVICE,
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&handle);
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if (ACPI_FAILURE(status)) {
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dev_err(&pdev->dev, "Unable fo find ACPI device %s\n",
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ACPI_KEYBOARD_BACKLIGHT_DEVICE);
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return -ENODEV;
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}
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cdev = kzalloc(sizeof(struct led_classdev), GFP_KERNEL);
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if (!cdev)
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return -ENOMEM;
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cdev->name = "chromeos::kbd_backlight";
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cdev->brightness_set = keyboard_led_set_brightness;
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cdev->max_brightness = ACPI_KEYBOARD_BACKLIGHT_MAX;
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cdev->brightness = cdev->max_brightness;
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cdev->flags |= LED_CORE_SUSPENDRESUME;
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ret = led_classdev_register(&pdev->dev, cdev);
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if (ret)
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goto err;
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platform_set_drvdata(pdev, cdev);
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return 0;
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err:
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kfree(cdev);
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return ret;
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}
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static int keyboard_led_remove(struct platform_device *pdev)
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{
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struct led_classdev *cdev = platform_get_drvdata(pdev);
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platform_set_drvdata(pdev, NULL);
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kfree(cdev);
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return 0;
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}
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static struct platform_driver keyboard_led_driver = {
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.driver = {
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.name = "chromeos-keyboard-leds",
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.owner = THIS_MODULE,
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},
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.probe = keyboard_led_probe,
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.remove = keyboard_led_remove,
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};
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module_platform_driver(keyboard_led_driver);
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MODULE_AUTHOR("Simon Que <sque@chromium.org>");
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MODULE_DESCRIPTION("ChromeOS Keyboard LED Driver");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:chromeos-keyboard-leds");
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