From patchwork Thu Sep 12 18:35:52 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Dunn X-Patchwork-Id: 2880651 Return-Path: X-Original-To: patchwork-linux-fbdev@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 0C7169F1E3 for ; Thu, 12 Sep 2013 18:37:34 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id A744A2034F for ; Thu, 12 Sep 2013 18:37:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 616F920378 for ; Thu, 12 Sep 2013 18:37:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755544Ab3ILShI (ORCPT ); Thu, 12 Sep 2013 14:37:08 -0400 Received: from smtp.newsguy.com ([74.209.136.69]:60147 "EHLO smtp.newsguy.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754899Ab3ILShE (ORCPT ); Thu, 12 Sep 2013 14:37:04 -0400 Received: from localhost.localdomain (181.sub-70-210-132.myvzw.com [70.210.132.181]) by smtp.newsguy.com (8.14.3/8.14.3) with ESMTP id r8CIa85j000132 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 12 Sep 2013 11:36:09 -0700 (PDT) (envelope-from mikedunn@newsguy.com) From: Mike Dunn To: thierry.reding@gmail.com Cc: Mike Dunn , Richard Purdie , Jingoo Han , Jean-Christophe Plagniol-Villard , Tomi Valkeinen , Grant Likely , Rob Herring , linux-pwm@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, Robert Jarzmik , Marek Vasut Subject: [PATCH] pwm-backlight: allow for non-increasing brightness levels Date: Thu, 12 Sep 2013 11:35:52 -0700 Message-Id: <1379010952-8928-1-git-send-email-mikedunn@newsguy.com> X-Mailer: git-send-email 1.8.1.5 Sender: linux-fbdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org X-Spam-Status: No, score=-7.8 required=5.0 tests=BAYES_00,KHOP_BIG_TO_CC, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently the driver assumes that the values specified in the brightness-levels device tree property increase as they are parsed from left to right. But boards that invert the signal between the PWM output and the backlight will need to specify decreasing brightness-levels. This patch removes the assumption that the last element of the array is the max value, and instead searches the array for the max value and uses that as the normalizing value when determining the duty cycle. Signed-off-by: Mike Dunn --- drivers/video/backlight/pwm_bl.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 1fea627..d66aaa0 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -27,6 +27,7 @@ struct pwm_bl_data { unsigned int period; unsigned int lth_brightness; unsigned int *levels; + unsigned int max_level; int (*notify)(struct device *, int brightness); void (*notify_after)(struct device *, @@ -57,7 +58,7 @@ static int pwm_backlight_update_status(struct backlight_device *bl) if (pb->levels) { duty_cycle = pb->levels[brightness]; - max = pb->levels[max]; + max = pb->levels[pb->max_level]; } else { duty_cycle = brightness; } @@ -195,7 +196,15 @@ static int pwm_backlight_probe(struct platform_device *pdev) } if (data->levels) { - max = data->levels[data->max_brightness]; + int i, max_value = 0, max_idx = 0; + for (i = 0; i <= data->max_brightness; i++) { + if (data->levels[i] > max_value) { + max_value = data->levels[i]; + max_idx = i; + } + } + pb->max_level = max_idx; + max = data->levels[max_idx]; pb->levels = data->levels; } else max = data->max_brightness;