Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760179AbcCEBXP (ORCPT ); Fri, 4 Mar 2016 20:23:15 -0500 Received: from mail-pf0-f174.google.com ([209.85.192.174]:33325 "EHLO mail-pf0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755989AbcCEBXN (ORCPT ); Fri, 4 Mar 2016 20:23:13 -0500 Date: Fri, 4 Mar 2016 17:23:09 -0800 From: Dmitry Torokhov To: Olof Johansson Cc: Rhard Purdie , Jacek Anaszewski , Duncan Laurie , Simon Que , Bryan Wu , Guenter Roeck , Evan McClain , linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org Subject: [PATCH] platform/chrome: Add Chrome OS keyboard backlight LEDs support Message-ID: <20160305012309.GA30176@dtor-ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6568 Lines: 202 This is a driver for ACPI-based keyboard backlight LEDs found on Chromebooks. The driver locates \\_SB.KBLT ACPI device and exports backlight as "chromeos::kbd_backlight" LED class device in sysfs. Signed-off-by: Simon Que Signed-off-by: Duncan Laurie Signed-off-by: Dmitry Torokhov --- Changes form previous submission: - moved from drivers/leds to drivers/platform/chrome - added method to retrieve brightness from ACPI - renamed to cros_kbd_led_backlight - config option renamed to CROS_KBD_LED_BACKLIGHT - no longer setting initial brightness to max brightness (although on Pixel 1 - Link - ACPI initially reports 100 as brightness anyway) I ran this on Pixel 1; Evan, could you give it a spin on your Pixel 2? Thanks! drivers/platform/chrome/Kconfig | 10 ++ drivers/platform/chrome/Makefile | 15 +-- drivers/platform/chrome/cros_kbd_led_backlight.c | 123 +++++++++++++++++++++++ 3 files changed, 141 insertions(+), 7 deletions(-) diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig index d03df4a..76bdae1 100644 --- a/drivers/platform/chrome/Kconfig +++ b/drivers/platform/chrome/Kconfig @@ -64,4 +64,14 @@ config CROS_EC_PROTO help ChromeOS EC communication protocol helpers. +config CROS_KBD_LED_BACKLIGHT + tristate "Backlight LED support for Chrome OS keyboards" + depends on LEDS_CLASS && ACPI + help + This option enables support for the keyboard backlight LEDs on + select Chrome OS systems. + + To compile this driver as a module, choose M here: the + module will be called cros_kbd_led_backlight. + endif # CHROMEOS_PLATFORMS diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile index bc498bd..4f34627 100644 --- a/drivers/platform/chrome/Makefile +++ b/drivers/platform/chrome/Makefile @@ -1,8 +1,9 @@ -obj-$(CONFIG_CHROMEOS_LAPTOP) += chromeos_laptop.o -obj-$(CONFIG_CHROMEOS_PSTORE) += chromeos_pstore.o -cros_ec_devs-objs := cros_ec_dev.o cros_ec_sysfs.o \ - cros_ec_lightbar.o cros_ec_vbc.o -obj-$(CONFIG_CROS_EC_CHARDEV) += cros_ec_devs.o -obj-$(CONFIG_CROS_EC_LPC) += cros_ec_lpc.o -obj-$(CONFIG_CROS_EC_PROTO) += cros_ec_proto.o +obj-$(CONFIG_CHROMEOS_LAPTOP) += chromeos_laptop.o +obj-$(CONFIG_CHROMEOS_PSTORE) += chromeos_pstore.o +cros_ec_devs-objs := cros_ec_dev.o cros_ec_sysfs.o \ + cros_ec_lightbar.o cros_ec_vbc.o +obj-$(CONFIG_CROS_EC_CHARDEV) += cros_ec_devs.o +obj-$(CONFIG_CROS_EC_LPC) += cros_ec_lpc.o +obj-$(CONFIG_CROS_EC_PROTO) += cros_ec_proto.o +obj-$(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 0000000..55477d7 --- /dev/null +++ b/drivers/platform/chrome/cros_kbd_led_backlight.c @@ -0,0 +1,123 @@ +/* + * 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 +#include +#include +#include +#include +#include +#include +#include +#include + +/* 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; + + platform_set_drvdata(pdev, cdev); + 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 "); +MODULE_DESCRIPTION("ChromeOS Keyboard backlight LED Driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:chromeos-keyboard-leds"); -- 2.7.0.rc3.207.g0ac5344 -- Dmitry