From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jacek Anaszewski Subject: Re: [PATCH v4] leds: Add Chrome OS keyboard LEDs driver Date: Tue, 23 Feb 2016 15:59:28 +0100 Message-ID: <56CC73D0.80106@samsung.com> References: <1456232462-2925-1-git-send-email-aeroevan@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mailout3.w1.samsung.com ([210.118.77.13]:48893 "EHLO mailout3.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751763AbcBWO7c (ORCPT ); Tue, 23 Feb 2016 09:59:32 -0500 Received: from eucpsbgm2.samsung.com (unknown [203.254.199.245]) by mailout3.w1.samsung.com (Oracle Communications Messaging Server 7.0.5.31.0 64bit (built May 5 2014)) with ESMTP id <0O3000LRZ9N5X250@mailout3.w1.samsung.com> for linux-leds@vger.kernel.org; Tue, 23 Feb 2016 14:59:29 +0000 (GMT) In-reply-to: <1456232462-2925-1-git-send-email-aeroevan@gmail.com> Sender: linux-leds-owner@vger.kernel.org List-Id: linux-leds@vger.kernel.org To: Jingoo Han , Lee Jones Cc: Evan McClain , Linux LED Subsystem , Simon Que , Duncan Laurie , Richard Purdie Hi Jingoo, Lee, I have my doubts if this driver wouldn't better fit for backlight subsystem. Actually the two are very similar and I wonder what are the criteria to follow when deciding if a driver should belong to one or to the other. Is the advertised purpose of the hardware the only one? Best regards, Jacek Anaszewski On 02/23/2016 02:01 PM, Evan McClain wrote: > From: Simon Que > > Some Chrome OS devices use ACPI-based keyboard backlight LEDs. > > Enable with menuconfig option under Device Drivers -> LED Support. > > Signed-off-by: Simon Que > Signed-off-by: Duncan Laurie > Signed-off-by: Evan McClain > --- > drivers/leds/Kconfig | 7 +++ > drivers/leds/Makefile | 1 + > drivers/leds/leds-chromeos-keyboard.c | 110 ++++++++++++++++++++++++++++++++++ > 3 files changed, 118 insertions(+) > create mode 100644 drivers/leds/leds-chromeos-keyboard.c > > diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig > index 1034696..89c81b6 100644 > --- a/drivers/leds/Kconfig > +++ b/drivers/leds/Kconfig > @@ -619,6 +619,13 @@ config LEDS_VERSATILE > This option enabled support for the LEDs on the ARM Versatile > and RealView boards. Say Y to enabled these. > > +config LEDS_CHROMEOS_KEYBOARD > + tristate "LED support for Chrome OS keyboards" > + depends on LEDS_CLASS && ACPI > + help > + This option enables support for the LEDs on Chrome OS keyboards. > + Say Y to enable keyboard LEDs on Chrome OS systems. > + > comment "LED Triggers" > source "drivers/leds/trigger/Kconfig" > > diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile > index 89c9b6f..5b96d15 100644 > --- a/drivers/leds/Makefile > +++ b/drivers/leds/Makefile > @@ -67,6 +67,7 @@ obj-$(CONFIG_LEDS_KTD2692) += leds-ktd2692.o > obj-$(CONFIG_LEDS_POWERNV) += leds-powernv.o > obj-$(CONFIG_LEDS_SEAD3) += leds-sead3.o > obj-$(CONFIG_LEDS_SN3218) += leds-sn3218.o > +obj-$(CONFIG_LEDS_CHROMEOS_KEYBOARD) += leds-chromeos-keyboard.o > > # LED SPI Drivers > obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o > diff --git a/drivers/leds/leds-chromeos-keyboard.c b/drivers/leds/leds-chromeos-keyboard.c > new file mode 100644 > index 0000000..4611fae > --- /dev/null > +++ b/drivers/leds/leds-chromeos-keyboard.c > @@ -0,0 +1,110 @@ > +/* > + * LED driver for Chrome OS keyboard backlight > + * > + * 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; > + > + if (!(cdev->flags & LED_SUSPENDED)) > + cdev->brightness = brightness; > + > + 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"); > +} > + > +static int keyboard_led_probe(struct platform_device *pdev) > +{ > + struct led_classdev *cdev; > + acpi_handle handle; > + acpi_status status; > + int ret; > + > + /* 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 fo find ACPI device %s\n", > + ACPI_KEYBOARD_BACKLIGHT_DEVICE); > + return -ENODEV; > + } > + > + cdev = devm_kzalloc(&pdev->dev, sizeof(struct led_classdev), GFP_KERNEL); > + if (!cdev) > + return -ENOMEM; > + > + cdev->name = "chromeos::kbd_backlight"; > + cdev->brightness_set = keyboard_led_set_brightness; > + cdev->max_brightness = ACPI_KEYBOARD_BACKLIGHT_MAX; > + cdev->flags |= LED_CORE_SUSPENDRESUME; > + > + ret = devm_led_classdev_register(&pdev->dev, cdev); > + if (ret) > + return ret; > + > + 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", > + .owner = THIS_MODULE, > + .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 LED Driver"); > +MODULE_LICENSE("GPL v2"); > +MODULE_ALIAS("platform:chromeos-keyboard-leds"); >