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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 | /* * Keyboard backlight LED driver for Chrome OS. * * Copyright (C) 2012 Google, Inc. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include <linux/acpi.h> #include <linux/leds.h> #include <linux/delay.h> #include <linux/err.h> #include <linux/module.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/platform_device.h> #include <linux/slab.h> /* Keyboard LED ACPI Device must be defined in firmware */ #define ACPI_KEYBOARD_BACKLIGHT_DEVICE "\\_SB.KBLT" #define ACPI_KEYBOARD_BACKLIGHT_READ ACPI_KEYBOARD_BACKLIGHT_DEVICE ".KBQC" #define ACPI_KEYBOARD_BACKLIGHT_WRITE ACPI_KEYBOARD_BACKLIGHT_DEVICE ".KBCM" #define ACPI_KEYBOARD_BACKLIGHT_MAX 100 static void keyboard_led_set_brightness(struct led_classdev *cdev, enum led_brightness brightness) { union acpi_object param; struct acpi_object_list input; acpi_status status; param.type = ACPI_TYPE_INTEGER; param.integer.value = brightness; input.count = 1; input.pointer = ¶m; status = acpi_evaluate_object(NULL, ACPI_KEYBOARD_BACKLIGHT_WRITE, &input, NULL); if (ACPI_FAILURE(status)) dev_err(cdev->dev, "Error setting keyboard LED value: %d\n", status); } static enum led_brightness keyboard_led_get_brightness(struct led_classdev *cdev) { unsigned long long brightness; acpi_status status; status = acpi_evaluate_integer(NULL, ACPI_KEYBOARD_BACKLIGHT_READ, NULL, &brightness); if (ACPI_FAILURE(status)) { dev_err(cdev->dev, "Error getting keyboard LED value: %d\n", status); return -EIO; } return brightness; } static int keyboard_led_probe(struct platform_device *pdev) { struct led_classdev *cdev; acpi_handle handle; acpi_status status; int error; /* Look for the keyboard LED ACPI Device */ status = acpi_get_handle(ACPI_ROOT_OBJECT, ACPI_KEYBOARD_BACKLIGHT_DEVICE, &handle); if (ACPI_FAILURE(status)) { dev_err(&pdev->dev, "Unable to find ACPI device %s: %d\n", ACPI_KEYBOARD_BACKLIGHT_DEVICE, status); return -ENXIO; } cdev = devm_kzalloc(&pdev->dev, sizeof(*cdev), GFP_KERNEL); if (!cdev) return -ENOMEM; cdev->name = "chromeos::kbd_backlight"; cdev->max_brightness = ACPI_KEYBOARD_BACKLIGHT_MAX; cdev->flags |= LED_CORE_SUSPENDRESUME; cdev->brightness_set = keyboard_led_set_brightness; cdev->brightness_get = keyboard_led_get_brightness; error = devm_led_classdev_register(&pdev->dev, cdev); if (error) return error; return 0; } static const struct acpi_device_id keyboard_led_id[] = { { "GOOG0002", 0 }, { } }; MODULE_DEVICE_TABLE(acpi, keyboard_led_id); static struct platform_driver keyboard_led_driver = { .driver = { .name = "chromeos-keyboard-leds", .acpi_match_table = ACPI_PTR(keyboard_led_id), }, .probe = keyboard_led_probe, }; module_platform_driver(keyboard_led_driver); MODULE_AUTHOR("Simon Que <sque@chromium.org>"); MODULE_DESCRIPTION("ChromeOS Keyboard backlight LED Driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:chromeos-keyboard-leds"); |