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-rw-r--r--drivers/platform/chrome/Kconfig10
-rw-r--r--drivers/platform/chrome/Makefile15
-rw-r--r--drivers/platform/chrome/cros_kbd_led_backlight.c122
3 files changed, 140 insertions, 7 deletions
diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig
index d03df4a60d05..76bdae1a93bb 100644
--- a/drivers/platform/chrome/Kconfig
+++ b/drivers/platform/chrome/Kconfig
@@ -64,4 +64,14 @@ config CROS_EC_PROTO
64 help 64 help
65 ChromeOS EC communication protocol helpers. 65 ChromeOS EC communication protocol helpers.
66 66
67config CROS_KBD_LED_BACKLIGHT
68 tristate "Backlight LED support for Chrome OS keyboards"
69 depends on LEDS_CLASS && ACPI
70 help
71 This option enables support for the keyboard backlight LEDs on
72 select Chrome OS systems.
73
74 To compile this driver as a module, choose M here: the
75 module will be called cros_kbd_led_backlight.
76
67endif # CHROMEOS_PLATFORMS 77endif # CHROMEOS_PLATFORMS
diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
index bc498bda8211..4f3462783a3c 100644
--- a/drivers/platform/chrome/Makefile
+++ b/drivers/platform/chrome/Makefile
@@ -1,8 +1,9 @@
1 1
2obj-$(CONFIG_CHROMEOS_LAPTOP) += chromeos_laptop.o 2obj-$(CONFIG_CHROMEOS_LAPTOP) += chromeos_laptop.o
3obj-$(CONFIG_CHROMEOS_PSTORE) += chromeos_pstore.o 3obj-$(CONFIG_CHROMEOS_PSTORE) += chromeos_pstore.o
4cros_ec_devs-objs := cros_ec_dev.o cros_ec_sysfs.o \ 4cros_ec_devs-objs := cros_ec_dev.o cros_ec_sysfs.o \
5 cros_ec_lightbar.o cros_ec_vbc.o 5 cros_ec_lightbar.o cros_ec_vbc.o
6obj-$(CONFIG_CROS_EC_CHARDEV) += cros_ec_devs.o 6obj-$(CONFIG_CROS_EC_CHARDEV) += cros_ec_devs.o
7obj-$(CONFIG_CROS_EC_LPC) += cros_ec_lpc.o 7obj-$(CONFIG_CROS_EC_LPC) += cros_ec_lpc.o
8obj-$(CONFIG_CROS_EC_PROTO) += cros_ec_proto.o 8obj-$(CONFIG_CROS_EC_PROTO) += cros_ec_proto.o
9obj-$(CONFIG_CROS_KBD_LED_BACKLIGHT) += cros_kbd_led_backlight.o
diff --git a/drivers/platform/chrome/cros_kbd_led_backlight.c b/drivers/platform/chrome/cros_kbd_led_backlight.c
new file mode 100644
index 000000000000..ca3e4da852b4
--- /dev/null
+++ b/drivers/platform/chrome/cros_kbd_led_backlight.c
@@ -0,0 +1,122 @@
1/*
2 * Keyboard backlight LED driver for Chrome OS.
3 *
4 * Copyright (C) 2012 Google, Inc.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 */
16
17#include <linux/acpi.h>
18#include <linux/leds.h>
19#include <linux/delay.h>
20#include <linux/err.h>
21#include <linux/module.h>
22#include <linux/init.h>
23#include <linux/kernel.h>
24#include <linux/platform_device.h>
25#include <linux/slab.h>
26
27/* Keyboard LED ACPI Device must be defined in firmware */
28#define ACPI_KEYBOARD_BACKLIGHT_DEVICE "\\_SB.KBLT"
29#define ACPI_KEYBOARD_BACKLIGHT_READ ACPI_KEYBOARD_BACKLIGHT_DEVICE ".KBQC"
30#define ACPI_KEYBOARD_BACKLIGHT_WRITE ACPI_KEYBOARD_BACKLIGHT_DEVICE ".KBCM"
31
32#define ACPI_KEYBOARD_BACKLIGHT_MAX 100
33
34static void keyboard_led_set_brightness(struct led_classdev *cdev,
35 enum led_brightness brightness)
36{
37 union acpi_object param;
38 struct acpi_object_list input;
39 acpi_status status;
40
41 param.type = ACPI_TYPE_INTEGER;
42 param.integer.value = brightness;
43 input.count = 1;
44 input.pointer = &param;
45
46 status = acpi_evaluate_object(NULL, ACPI_KEYBOARD_BACKLIGHT_WRITE,
47 &input, NULL);
48 if (ACPI_FAILURE(status))
49 dev_err(cdev->dev, "Error setting keyboard LED value: %d\n",
50 status);
51}
52
53static enum led_brightness
54keyboard_led_get_brightness(struct led_classdev *cdev)
55{
56 unsigned long long brightness;
57 acpi_status status;
58
59 status = acpi_evaluate_integer(NULL, ACPI_KEYBOARD_BACKLIGHT_READ,
60 NULL, &brightness);
61 if (ACPI_FAILURE(status)) {
62 dev_err(cdev->dev, "Error getting keyboard LED value: %d\n",
63 status);
64 return -EIO;
65 }
66
67 return brightness;
68}
69
70static int keyboard_led_probe(struct platform_device *pdev)
71{
72 struct led_classdev *cdev;
73 acpi_handle handle;
74 acpi_status status;
75 int error;
76
77 /* Look for the keyboard LED ACPI Device */
78 status = acpi_get_handle(ACPI_ROOT_OBJECT,
79 ACPI_KEYBOARD_BACKLIGHT_DEVICE,
80 &handle);
81 if (ACPI_FAILURE(status)) {
82 dev_err(&pdev->dev, "Unable to find ACPI device %s: %d\n",
83 ACPI_KEYBOARD_BACKLIGHT_DEVICE, status);
84 return -ENXIO;
85 }
86
87 cdev = devm_kzalloc(&pdev->dev, sizeof(*cdev), GFP_KERNEL);
88 if (!cdev)
89 return -ENOMEM;
90
91 cdev->name = "chromeos::kbd_backlight";
92 cdev->max_brightness = ACPI_KEYBOARD_BACKLIGHT_MAX;
93 cdev->flags |= LED_CORE_SUSPENDRESUME;
94 cdev->brightness_set = keyboard_led_set_brightness;
95 cdev->brightness_get = keyboard_led_get_brightness;
96
97 error = devm_led_classdev_register(&pdev->dev, cdev);
98 if (error)
99 return error;
100
101 return 0;
102}
103
104static const struct acpi_device_id keyboard_led_id[] = {
105 { "GOOG0002", 0 },
106 { }
107};
108MODULE_DEVICE_TABLE(acpi, keyboard_led_id);
109
110static struct platform_driver keyboard_led_driver = {
111 .driver = {
112 .name = "chromeos-keyboard-leds",
113 .acpi_match_table = ACPI_PTR(keyboard_led_id),
114 },
115 .probe = keyboard_led_probe,
116};
117module_platform_driver(keyboard_led_driver);
118
119MODULE_AUTHOR("Simon Que <sque@chromium.org>");
120MODULE_DESCRIPTION("ChromeOS Keyboard backlight LED Driver");
121MODULE_LICENSE("GPL");
122MODULE_ALIAS("platform:chromeos-keyboard-leds");
generated by cgit v1.2.2 (git 2.25.0) at 2026-04-27 12:05:11 -0400