Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752355AbdGQV2e (ORCPT ); Mon, 17 Jul 2017 17:28:34 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:34949 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752371AbdGQV2c (ORCPT ); Mon, 17 Jul 2017 17:28:32 -0400 From: Enric Balletbo i Serra To: Thierry Reding , Lee Jones , Daniel Thompson , Jingoo Han , Bartlomiej Zolnierkiewicz , Rob Herring , Pavel Machek , Richard Purdie , Jacek Anaszewski , Heiko Stuebner Cc: linux-pwm@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, groeck@chromium.org, linux-rockchip@lists.infradead.org Subject: [PATCH v3 3/5] pwm-backlight: add support for PWM delays proprieties. Date: Mon, 17 Jul 2017 23:28:09 +0200 Message-Id: <20170717212811.25374-3-enric.balletbo@collabora.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20170717212811.25374-1-enric.balletbo@collabora.com> References: <20170717212811.25374-1-enric.balletbo@collabora.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3202 Lines: 96 Some panels (i.e. N116BGE-L41), in their power sequence specifications, request a delay between set the PWM signal and enable the backlight and between clear the PWM signal and disable the backlight. Add support for the new post-pwm-on-delay-us and pwm-off-delay-us proprieties to meet the timings. Signed-off-by: Enric Balletbo i Serra --- Changes since v2: - Move the pwm/enable sequence to another patch (Thierry Reding) Changes since v1: - As suggested by Daniel Thompson - Do not assume power-on delay and power-off delay will be the same - Move the check of dt property to the parse dt function. drivers/video/backlight/pwm_bl.c | 17 +++++++++++++++++ include/linux/pwm_backlight.h | 1 + 2 files changed, 18 insertions(+) diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 909a686..528155d 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -10,6 +10,7 @@ * published by the Free Software Foundation. */ +#include #include #include #include @@ -35,6 +36,7 @@ struct pwm_bl_data { struct gpio_desc *enable_gpio; unsigned int scale; bool legacy; + unsigned int pwm_delay[2]; int (*notify)(struct device *, int brightness); void (*notify_after)(struct device *, @@ -56,6 +58,9 @@ static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness) pwm_enable(pb->pwm); + if (pb->pwm_delay[0]) + usleep_range(pb->pwm_delay[0], pb->pwm_delay[0] * 2); + if (pb->enable_gpio) gpiod_set_value_cansleep(pb->enable_gpio, 1); @@ -70,6 +75,9 @@ static void pwm_backlight_power_off(struct pwm_bl_data *pb) if (pb->enable_gpio) gpiod_set_value_cansleep(pb->enable_gpio, 0); + if (pb->pwm_delay[1]) + usleep_range(pb->pwm_delay[1], pb->pwm_delay[1] * 2); + pwm_config(pb->pwm, 0, pb->period); pwm_disable(pb->pwm); @@ -175,6 +183,14 @@ static int pwm_backlight_parse_dt(struct device *dev, data->max_brightness--; } + /* + * These values are optional and set as 0 by default, the out values + * are modified only if a valid u32 value can be decoded. + */ + of_property_read_u32(node, "post-pwm-on-delay-us", + &data->pwm_delay[0]); + of_property_read_u32(node, "pwm-off-delay-us", &data->pwm_delay[1]); + data->enable_gpio = -EINVAL; return 0; } @@ -273,6 +289,7 @@ static int pwm_backlight_probe(struct platform_device *pdev) pb->exit = data->exit; pb->dev = &pdev->dev; pb->enabled = false; + memcpy(pb->pwm_delay, data->pwm_delay, sizeof(pb->pwm_delay)); pb->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable", GPIOD_ASIS); diff --git a/include/linux/pwm_backlight.h b/include/linux/pwm_backlight.h index efdd922..bf37131 100644 --- a/include/linux/pwm_backlight.h +++ b/include/linux/pwm_backlight.h @@ -13,6 +13,7 @@ struct platform_pwm_backlight_data { unsigned int lth_brightness; unsigned int pwm_period_ns; unsigned int *levels; + unsigned int pwm_delay[2]; /* TODO remove once all users are switched to gpiod_* API */ int enable_gpio; int (*init)(struct device *dev); -- 2.9.3