From patchwork Thu Feb 23 11:23:09 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: ChiaEn Wu X-Patchwork-Id: 656158 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 680EFC636D6 for ; Thu, 23 Feb 2023 11:24:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233509AbjBWLYN (ORCPT ); Thu, 23 Feb 2023 06:24:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56192 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233101AbjBWLYN (ORCPT ); Thu, 23 Feb 2023 06:24:13 -0500 Received: from mg.richtek.com (mg.richtek.com [220.130.44.152]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 9F0CF59FC; Thu, 23 Feb 2023 03:24:09 -0800 (PST) X-MailGates: (flag:4,DYNAMIC,BADHELO,RELAY,NOHOST:PASS)(compute_score:DE LIVER,40,3) Received: from 192.168.10.46 by mg.richtek.com with MailGates ESMTP Server V5.0(14980:0:AUTH_RELAY) (envelope-from ); Thu, 23 Feb 2023 19:23:39 +0800 (CST) Received: from ex4.rt.l (192.168.10.47) by ex3.rt.l (192.168.10.46) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.20; Thu, 23 Feb 2023 19:23:39 +0800 Received: from linuxcarl2.richtek.com (192.168.10.154) by ex4.rt.l (192.168.10.45) with Microsoft SMTP Server id 15.2.1118.20 via Frontend Transport; Thu, 23 Feb 2023 19:23:38 +0800 From: ChiaEn Wu To: , , , , , , CC: , , , , , , , , ChiaEn Wu Subject: [PATCH v17 RESEND 3/3] docs: leds: Add MT6370 RGB LED pattern document Date: Thu, 23 Feb 2023 19:23:09 +0800 Message-ID: X-Mailer: git-send-email 1.8.3.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-leds@vger.kernel.org From: ChiYuan Huang Document the MT6370 RGB LED pattern trigger. This simply describe how the pattern works, each timing period, and the pattern diagram for MT6370 RGB LED. Signed-off-by: ChiYuan Huang Signed-off-by: ChiaEn Wu --- Documentation/leds/leds-mt6370-rgb.rst | 64 ++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) create mode 100644 Documentation/leds/leds-mt6370-rgb.rst diff --git a/Documentation/leds/leds-mt6370-rgb.rst b/Documentation/leds/leds-mt6370-rgb.rst new file mode 100644 index 00000000..d1b2e4f --- /dev/null +++ b/Documentation/leds/leds-mt6370-rgb.rst @@ -0,0 +1,64 @@ +.. SPDX-License-Identifier: GPL-2.0 + +========================================= +Kernel driver for Mediatek MT6370 RGB LED +========================================= + +Description +----------- + +The MT6370 integrates a four-channel RGB LED driver, designed to provide a +variety of lighting effect for mobile device applications. The RGB LED driver +includes a smart LED string controller and it can drive 3 channels of LEDs with +a sink current up to 24mA and a CHG_VIN power good indicator LED with sink +current up to 6mA. It provides three operation modes for RGB LEDs: +PWM Dimming mode, breath pattern mode, and constant current mode. The device +can increase or decrease the brightness of the RGB LED via I2C interface. + +The breath pattern for a channel can be programmed using the "pattern" trigger, +using the hw_pattern attribute. + +/sys/class/leds//hw_pattern +-------------------------------- + +Specify a hardware breath pattern for a MT6370 RGB LED. + +The breath pattern is a series of timing pairs, with the hold-time expressed in +milliseconds. And the brightness is controlled by +'/sys/class/leds//brightness'. The pattern doesn't include the brightness +setting. Hardware pattern only controls the timing for each pattern stage +depending on the current brightness setting. + +Pattern diagram:: + + "0 Tr1 0 Tr2 0 Tf1 0 Tf2 0 Ton 0 Toff" --> '0' for dummy brightness code + + ^ + | ============ + | / \ / +Icurr | / \ / + | / \ / + | / \ / .....repeat + | / \ / + | --- --- --- + |--- --- --- + +----------------------------------============------------> Time + < Tr1>< Ton >< Toff >< Tr1> + +Timing description:: + +Tr1: First rising time for duty 0 to 30%. +Tr2: Second rising time for duty 31% to 100%. +Ton: On time for duty 100%. +Tf1: First falling time for duty 100% to 31%. +Tf2: Second falling time for duty 30% to 0%. +Toff: Off time for duty 0%. + +Tr1/Tr2/Tf1/Tf2/Ton: 125ms to 3125ms, 200ms per step. +Toff: 250ms to 6250ms, 400ms per step. + +Pattern example:: + + "0 125 0 125 0 125 0 125 0 625 0 1050" + +This Will configure Tr1/Tr2/Tf1/Tf2 to 125m, Ton to 625ms, and Toff to 1050ms.