From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936606AbaH1LB6 (ORCPT ); Thu, 28 Aug 2014 07:01:58 -0400 Received: from mail-pa0-f49.google.com ([209.85.220.49]:60481 "EHLO mail-pa0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936487AbaH1LB4 (ORCPT ); Thu, 28 Aug 2014 07:01:56 -0400 From: Gyungoh Yoo X-Google-Original-From: Gyungoh Yoo To: rdunlap@infradead.org Cc: jack.yoo@skyworksinc.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 7/7] Adding SKY81452 backlight document Date: Thu, 28 Aug 2014 20:01:49 +0900 Message-Id: <1409223709-23671-1-git-send-email-jack.yoo@skyworksinc.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1409222307-23225-1-git-send-email-jack.yoo@skyworksinc.com> References: <1409222307-23225-1-git-send-email-jack.yoo@skyworksinc.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org v2: split the patches --- Documentation/backlight/sky81452-backlight.txt | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 Documentation/backlight/sky81452-backlight.txt diff --git a/Documentation/backlight/sky81452-backlight.txt b/Documentation/backlight/sky81452-backlight.txt new file mode 100644 index 0000000..39f2f8c --- /dev/null +++ b/Documentation/backlight/sky81452-backlight.txt @@ -0,0 +1,26 @@ +backlight driver for sky81452 +========================== + +* Skyworks Solutions SKY81452 : + High-Efficiency, Six-Channel White LED Driver with Touch Panel Bias Supply + +Description +----------- +The SKY81452 is a highly integrated, high-efficiency LED backlight solution for +tablets, notebook computers, monitors, and other portable devices. + +The SKY81452 supports Direct Pulse Width Modulation(DPWM) dimming and Analog +Pulse Width Modulation (APWM). In the DPWM dimming mode, the output waveform +follows the Pulse Width Modulation Input(PWMI) signal and the current level is +set by I2C control and an external RSET resistor. In the APWM mode, the PWMI +signal duty and the I2C brightness control signal are multiplied to control +the output current level. + +The driver exports some additional attributes for SKY81452 backlight. +- enable : Current sink channels. Bit0 is for channel 1, Bit1 is for channel 2 + and Bit2 is for channel 3. In same way, Bit5 is for channel 6. + For example, if 5 is written to this attribute, channel 1 and + channel 3 are enabled. +- open : Shows an open LED fault. +- short : Shows an short LED fault. +- fault : Shows information about over-current and over-temperature. -- 1.9.1