From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BA3BEC49ED6 for ; Wed, 11 Sep 2019 18:01:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8A4182081B for ; Wed, 11 Sep 2019 18:01:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="OMWrhrtZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729956AbfIKSBj (ORCPT ); Wed, 11 Sep 2019 14:01:39 -0400 Received: from fllv0015.ext.ti.com ([198.47.19.141]:55976 "EHLO fllv0015.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729729AbfIKSBX (ORCPT ); Wed, 11 Sep 2019 14:01:23 -0400 Received: from fllv0034.itg.ti.com ([10.64.40.246]) by fllv0015.ext.ti.com (8.15.2/8.15.2) with ESMTP id x8BI1Hce000896; Wed, 11 Sep 2019 13:01:17 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1568224877; bh=S8BtTodIkwTN2xYbwppqWLNg7DkbMnBekNn+USRsSks=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=OMWrhrtZwk9VJEOtsN8gA8chauwX/Pbfdp5YfghNlWeWSsVxRwLMBg4OdwWJMhxGD PArtS/V1bd+XK1BpqRcGDhD1SZOhM7PSaFPPh0SLG1pIQqkABlPIcBb8kdRBn3e2H4 IEG8rVYrD0O+XRrAF1/o4hcT9O2Dq5e5QAzicW7E= Received: from DLEE112.ent.ti.com (dlee112.ent.ti.com [157.170.170.23]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id x8BI1HCV007240 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 11 Sep 2019 13:01:17 -0500 Received: from DLEE115.ent.ti.com (157.170.170.26) by DLEE112.ent.ti.com (157.170.170.23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5; Wed, 11 Sep 2019 13:01:17 -0500 Received: from lelv0326.itg.ti.com (10.180.67.84) by DLEE115.ent.ti.com (157.170.170.26) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5 via Frontend Transport; Wed, 11 Sep 2019 13:01:17 -0500 Received: from localhost (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0326.itg.ti.com (8.15.2/8.15.2) with ESMTP id x8BI1HMi063840; Wed, 11 Sep 2019 13:01:17 -0500 From: Dan Murphy To: , CC: , , , Dan Murphy Subject: [PATCH v5 2/9] documention: leds: Add multicolor class documentation Date: Wed, 11 Sep 2019 13:01:08 -0500 Message-ID: <20190911180115.21035-3-dmurphy@ti.com> X-Mailer: git-send-email 2.22.0.214.g8dca754b1e In-Reply-To: <20190911180115.21035-1-dmurphy@ti.com> References: <20190911180115.21035-1-dmurphy@ti.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add the support documentation on the multicolor LED framework. This document defines the directores and file generated by the multicolor framework. It also documents usage. Signed-off-by: Dan Murphy --- Documentation/leds/index.rst | 1 + Documentation/leds/leds-class-multicolor.rst | 149 +++++++++++++++++++ 2 files changed, 150 insertions(+) create mode 100644 Documentation/leds/leds-class-multicolor.rst diff --git a/Documentation/leds/index.rst b/Documentation/leds/index.rst index 060f4e485897..bc70c6aa7138 100644 --- a/Documentation/leds/index.rst +++ b/Documentation/leds/index.rst @@ -9,6 +9,7 @@ LEDs leds-class leds-class-flash + leds-class-multicolor ledtrig-oneshot ledtrig-transient ledtrig-usbport diff --git a/Documentation/leds/leds-class-multicolor.rst b/Documentation/leds/leds-class-multicolor.rst new file mode 100644 index 000000000000..0b40c85f417a --- /dev/null +++ b/Documentation/leds/leds-class-multicolor.rst @@ -0,0 +1,149 @@ +==================================== +Multi Color LED handling under Linux +==================================== + +Description +=========== +There are varying monochrome LED colors available for application. These +LEDs can be used as a single use case LED or can be mixed with other color +LEDs to produce the full spectrum of color. Color LEDs that are grouped +can be presented under a single LED node with individual color control. +The multicolor class groups these LEDs and allows dynamically setting the value +of a single LED or setting the intensity values of the LEDs in the group and +updating the LEDs virtually simultaneously. + +Multicolor Class Control +======================== +The multicolor class presents the LED groups under a directory called "colors". +This directory is a child under the LED parent node created by the led_class +framework. The led_class framework is documented in led-class.rst within this +documentation directory. + +Each colored LED is given its own directory. These directories will be one of +LED_COLOR_ID_* definitions from the header include/dt-bindings/leds/common.h. +Under these directories the intensity and max_intensity files are presented for +each LED. + +Directory Layout Example +======================== +root:/sys/class/leds/rgb:grouped_leds# ls -lR colors/ +colors/: +drwxr-xr-x 2 root root 0 Jun 28 20:21 blue +drwxr-xr-x 2 root root 0 Jun 28 20:21 green +drwxr-xr-x 2 root root 0 Jun 28 20:21 red +-rw------- 1 root root 4096 Jun 28 20:21 color_mix + +colors/blue: +-rw------- 1 root root 4096 Jun 28 20:21 intensity +-r-------- 1 root root 4096 Jun 28 20:27 max_intensity +-r-------- 1 root root 4096 Jun 28 20:21 color_id + +colors/green: +-rw------- 1 root root 4096 Jun 28 20:22 intensity +-r-------- 1 root root 4096 Jun 28 20:27 max_intensity +-r-------- 1 root root 4096 Jun 28 20:21 color_id + +colors/red: +-rw------- 1 root root 4096 Jun 28 20:21 intensity +-r-------- 1 root root 4096 Jun 28 20:27 max_intensity +-r-------- 1 root root 4096 Jun 28 20:21 color_id + +Multicolor Color Mixing +======================= +Multicolor monochrome LEDs intensity can be modified and mixed to produce a +varying array of colors. The color_mix file gives the user the ability to write +all the monochrome LEDs registered in the directory with a single call. +To create a specific color from monochrome LEDs the color_mix file needs to be +written with each color's intensity. The order in which the monochrome LEDs +should be written is based on the colors color_id. The LEDs brightness will be +updated on the next call to the parent brightness file. + +For example: +cat /sys/class/leds/rgb:grouped_leds/red/color_id +0 +cat /sys/class/leds/rgb:grouped_leds/green/color_id +1 +cat /sys/class/leds/rgb:grouped_leds/blue/color_id +2 + +red - color_id = 0 +green - color_id = 1 +blue - color_id = 2 + +These id's are the order in which to write the color_mix file. + +echo " " > color_mix + +echo "80 00 80" > color_mix + +The order of the monochrome LEDs are determined during multicolor class +registration and will not change unless unregistered and re-registered. + +Other example with amber monochrome LED: +blue - color_id = 0 +amber - color_id = 1 + +In this example blue is at ID 0 and amber ID is 1 so the user would write +echo " " > color_mix + +echo "38 80" > color_mix + +If a single monochrome LED needs to be modified then the user would write the +colors//intensity file. + + +Multicolor Class Brightness Control +=================================== +The multiclor class framework will calculate each monochrome LEDs intensity. + +The brightness level for each LED is calculated based on the color LED +intensity setting divided by the color LED max intensity setting multiplied by +the requested value. + +led_brightness = requested_value * led_color_intensity/led_color_max_intensity + +Example: +Three LEDs are present in the group as defined in "Directory Layout Example" +within this document. + +A user first writes the color LED brightness file with the brightness level that +is necessary to achieve a blueish violet output from the RGB LED group. + +echo 138 > /sys/class/leds/rgb:grouped_leds/red/intensity +echo 43 > /sys/class/leds/rgb:grouped_leds/green/intensity +echo 226 > /sys/class/leds/rgb:grouped_leds/blue/intensity + +red - + intensity = 138 + max_intensity = 255 +green - + intensity = 43 + max_intensity = 255 +blue - + intensity = 226 + max_intensity = 255 + +The user can control the brightness of that RGB group by writing the parent +'brightness' control. Assuming a parent max_brightness of 255 the user may want +to dim the LED color group to half. The user would write a value of 128 to the +parent brightness file then the values written to each LED will be adjusted +base on this value + +cat /sys/class/leds/rgb:grouped_leds/max_brightness +255 +echo 128 > /sys/class/leds/rgb:grouped_leds/brightness + +adjusted_red_value = 128 * 138/255 = 69 +adjusted_green_value = 128 * 43/255 = 21 +adjusted_blue_value = 128 * 226/255 = 113 + +Reading the parent brightness file will return the current brightness value of +the color LED group. + +cat /sys/class/leds/rgb:grouped_leds/max_brightness +255 + +echo 128 > /sys/class/leds/rgb:grouped_leds/brightness + +cat /sys/class/leds/rgb:grouped_leds/max_brightness +128 -- 2.22.0.214.g8dca754b1e