Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759909AbcCEBuJ (ORCPT ); Fri, 4 Mar 2016 20:50:09 -0500 Received: from mail-lb0-f173.google.com ([209.85.217.173]:35753 "EHLO mail-lb0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759462AbcCEBuG (ORCPT ); Fri, 4 Mar 2016 20:50:06 -0500 MIME-Version: 1.0 In-Reply-To: <20160305012309.GA30176@dtor-ws> References: <20160305012309.GA30176@dtor-ws> Date: Fri, 4 Mar 2016 17:50:04 -0800 Message-ID: Subject: Re: [PATCH] platform/chrome: Add Chrome OS keyboard backlight LEDs support From: Guenter Roeck To: Dmitry Torokhov Cc: Olof Johansson , Rhard Purdie , Jacek Anaszewski , Duncan Laurie , Simon Que , Bryan Wu , Guenter Roeck , Evan McClain , linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7846 Lines: 210 On Fri, Mar 4, 2016 at 5:23 PM, Dmitry Torokhov wrote: > 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); Is this needed ? Thanks, Guenter > + 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