From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753072AbeCPC7r (ORCPT ); Thu, 15 Mar 2018 22:59:47 -0400 Received: from mail-pg0-f65.google.com ([74.125.83.65]:42926 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752404AbeCPC7p (ORCPT ); Thu, 15 Mar 2018 22:59:45 -0400 X-Google-Smtp-Source: AG47ELtl9WMM8p3hd7ipXWjPRuLPfeWt9WXKDu+kIhqqHu2vo0J24aaiz0ncvTam11BqhW4ilkgNoQ== From: Alexandru M Stan To: David Airlie , Rob Herring , Mark Rutland , Archit Taneja , Andrzej Hajda , Laurent Pinchart , Sean Paul Cc: devicetree@vger.kernel.org, Enric Balletbo i Serra , Heiko Stuebner , briannorris@chromium.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, dianders@chromium.org, linux-rockchip@lists.infradead.org, marcheu@chromium.org, hoegsberg@chromium.org, Thierry Escande , Jeffy Chen , Alexandru M Stan , Yakir Yang , Daniel Vetter , Marek Szyprowski , zain wang , Sylwester Nawrocki Subject: [PATCH 2/2] drm/bridge: analogix: Enable EDP_BACKLIGHT_FREQ_PWM_PIN_PASSTHRU Date: Thu, 15 Mar 2018 19:56:59 -0700 Message-Id: <20180316025659.217423-3-amstan@chromium.org> X-Mailer: git-send-email 2.13.5 In-Reply-To: <20180316025659.217423-1-amstan@chromium.org> References: <20180316025659.217423-1-amstan@chromium.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Configure the DPCD registers for the backlight to respect the pwm frequency of the input. We sometimes don't want it to generate its own. Signed-off-by: Alexandru M Stan --- drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 48 ++++++++++++++++++++++ drivers/gpu/drm/bridge/analogix/analogix_dp_core.h | 1 + 2 files changed, 49 insertions(+) diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c index 5c52307146c7..b830403be8eb 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c @@ -916,6 +916,46 @@ static irqreturn_t analogix_dp_irq_thread(int irq, void *arg) return IRQ_HANDLED; } +static int analogix_dp_backlight_pwm_passthru(struct analogix_dp_device *dp) +{ + u8 value; + const u8 expected_cap = DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP | + DP_EDP_BACKLIGHT_FREQ_PWM_PIN_PASSTHRU_CAP; + int ret = 0; + + ret = drm_dp_dpcd_readb(&dp->aux, DP_EDP_BACKLIGHT_ADJUSTMENT_CAP, + &value); + if (ret != 1) { + DRM_DEV_ERROR(dp->dev, + "backlight PWM passthru: Can't read BACKLIGHT_ADJUSTMENT_CAP\n"); + return ret; + } + + if ((value & expected_cap) != expected_cap) { + DRM_DEV_ERROR(dp->dev, + "panel doesn't support backlight PWM passthru, BACKLIGHT_ADJUSTMENT_CAP=0x%02x\n", + value); + return -1; + } + + ret = drm_dp_dpcd_readb(&dp->aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, + &value); + if (ret != 1) { + DRM_DEV_ERROR(dp->dev, + "backlight PWM passthru: Can't read BACKLIGHT_MODE_SET_REGISTER\n"); + return ret; + } + + value |= DP_EDP_BACKLIGHT_FREQ_PWM_PIN_PASSTHRU_ENABLE; + ret = drm_dp_dpcd_writeb(&dp->aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, + value); + if (ret != 1) { + DRM_DEV_ERROR(dp->dev, + "backlight PWM passthru: Can't write BACKLIGHT_MODE_SET_REGISTER\n"); + } + return ret; +} + static void analogix_dp_commit(struct analogix_dp_device *dp) { int ret; @@ -954,6 +994,12 @@ static void analogix_dp_commit(struct analogix_dp_device *dp) dp->psr_enable = analogix_dp_detect_sink_psr(dp); if (dp->psr_enable) analogix_dp_enable_sink_psr(dp); + + if (dp->backlight_pwm_passthru) { + if (analogix_dp_backlight_pwm_passthru(dp) != 1) + DRM_DEV_ERROR(dp->dev, + "Could not enable backlight pwm pin passthru.\n"); + } } /* @@ -1424,6 +1470,8 @@ analogix_dp_bind(struct device *dev, struct drm_device *drm_dev, if (IS_ERR(dp->reg_base)) return ERR_CAST(dp->reg_base); + dp->backlight_pwm_passthru = + of_property_read_bool(dev->of_node, "backlight-pwm-passthru"); dp->force_hpd = of_property_read_bool(dev->of_node, "force-hpd"); dp->hpd_gpio = of_get_named_gpio(dev->of_node, "hpd-gpios", 0); diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h index 6a96ef7e6934..aea51413e78e 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h @@ -171,6 +171,7 @@ struct analogix_dp_device { struct phy *phy; int dpms_mode; int hpd_gpio; + bool backlight_pwm_passthru; bool force_hpd; bool psr_enable; bool fast_train_support; -- 2.13.5