From patchwork Wed Nov 7 08:55:07 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Enric Balletbo i Serra X-Patchwork-Id: 10675453 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2234214D6 for ; Fri, 9 Nov 2018 08:04:41 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 171902E367 for ; Fri, 9 Nov 2018 08:04:41 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0BF532E376; Fri, 9 Nov 2018 08:04:41 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED,UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 8F4E02E367 for ; Fri, 9 Nov 2018 08:04:40 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1E43D6E777; Fri, 9 Nov 2018 08:04:16 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by gabe.freedesktop.org (Postfix) with ESMTPS id EB1946E50B for ; Wed, 7 Nov 2018 08:55:16 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: eballetbo) with ESMTPSA id 0F337263BB6 From: Enric Balletbo i Serra To: linux-kernel@vger.kernel.org, robert.jarzmik@free.fr, daniel.thompson@linaro.org, lee.jones@linaro.org Subject: [PATCH v3] backlight: pwm_bl: Fix brightness levels for non-DT case. Date: Wed, 7 Nov 2018 09:55:07 +0100 Message-Id: <20181107085507.26126-1-enric.balletbo@collabora.com> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 X-Mailman-Approved-At: Fri, 09 Nov 2018 08:04:13 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, linux-fbdev@vger.kernel.org, Bartlomiej Zolnierkiewicz , Jingoo Han , stable@vger.kernel.org, Thierry Reding , dri-devel@lists.freedesktop.org, u.kleine-koenig@pengutronix.de, kernel@collabora.com Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP Commit '88ba95bedb79 ("backlight: pwm_bl: Compute brightness of LED linearly to human eye")' allows the possibility to compute a default brightness table when there isn't the brightness-levels property in the DT. Unfortunately the changes made broke the pwm backlight for the non-DT boards. Usually, the non-DT boards don't pass the brightness levels via platform data, instead, it sets the max_brightness in their platform data and the driver calculates the level without a table. The offending patch assumed that when there is no brightness levels table we should create one, but this is clearly wrong for the non-DT case. After this patch the code handles the DT and the non-DT case taking in consideration also if max_brightness is set or not. Fixes: 88ba95bedb79 ("backlight: pwm_bl: Compute brightness of LED linearly to human eye") Cc: Reported-by: Robert Jarzmik Signed-off-by: Enric Balletbo i Serra Tested-by: Robert Jarzmik Acked-by: Daniel Thompson --- Changes in v3: - Fixed some typos in commit message. - Removed ' in Fixes tag. Changes in v2: - Rebase on top of mainline - Add Tested-by and Acked-by tags. drivers/video/backlight/pwm_bl.c | 41 +++++++++++++++++++++++++++----- 1 file changed, 35 insertions(+), 6 deletions(-) diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 678b27063198..f9ef0673a083 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -562,7 +562,30 @@ static int pwm_backlight_probe(struct platform_device *pdev) goto err_alloc; } - if (!data->levels) { + if (data->levels) { + /* + * For the DT case, only when brightness levels is defined + * data->levels is filled. For the non-DT case, data->levels + * can come from platform data, however is not usual. + */ + for (i = 0; i <= data->max_brightness; i++) { + if (data->levels[i] > pb->scale) + pb->scale = data->levels[i]; + + pb->levels = data->levels; + } + } else if (!data->max_brightness) { + /* + * If no brightness levels are provided and max_brightness is + * not set, use the default brightness table. For the DT case, + * max_brightness is set to 0 when brightness levels is not + * specified. For the non-DT case, max_brightness is usually + * set to some value. + */ + + /* Get the PWM period (in nanoseconds) */ + pwm_get_state(pb->pwm, &state); + ret = pwm_backlight_brightness_default(&pdev->dev, data, state.period); if (ret < 0) { @@ -570,13 +593,19 @@ static int pwm_backlight_probe(struct platform_device *pdev) "failed to setup default brightness table\n"); goto err_alloc; } - } - for (i = 0; i <= data->max_brightness; i++) { - if (data->levels[i] > pb->scale) - pb->scale = data->levels[i]; + for (i = 0; i <= data->max_brightness; i++) { + if (data->levels[i] > pb->scale) + pb->scale = data->levels[i]; - pb->levels = data->levels; + pb->levels = data->levels; + } + } else { + /* + * That only happens for the non-DT case, where platform data + * sets the max_brightness value. + */ + pb->scale = data->max_brightness; } pb->lth_brightness = data->lth_brightness * (state.period / pb->scale);