From patchwork Thu Nov 29 12:42:47 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Maarten Lankhorst X-Patchwork-Id: 10704505 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 CEFD214BD for ; Thu, 29 Nov 2018 12:42:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BF3B42EE44 for ; Thu, 29 Nov 2018 12:42:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B32CC2EE5A; Thu, 29 Nov 2018 12:42:53 +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 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 4CE012EE44 for ; Thu, 29 Nov 2018 12:42:53 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 617FA6E4AE; Thu, 29 Nov 2018 12:42:52 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mblankhorst.nl (mblankhorst.nl [141.105.120.124]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3D2E36E4BF for ; Thu, 29 Nov 2018 12:42:51 +0000 (UTC) From: Maarten Lankhorst To: intel-gfx@lists.freedesktop.org Date: Thu, 29 Nov 2018 13:42:47 +0100 Message-Id: <20181129124247.11780-2-maarten.lankhorst@linux.intel.com> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20181129124247.11780-1-maarten.lankhorst@linux.intel.com> References: <20181129124247.11780-1-maarten.lankhorst@linux.intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 2/2] drm/i915/backlight: Fix backlight takeover on LPT, v2. X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Hans de Goede , Tolga Cakir , Basil Eric Rabi Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP On lynxpoint the bios sometimes sets up the backlight using the CPU display, but the driver expects using the PWM PCH override register. Read the value from the CPU register, then convert it to the other units by converting from the old duty cycle, to freq, to the new units. This value is then programmed in the override register, after which we set the override and disable the CPU display control. This allows us to switch the source without flickering, and make the backlight controls work in the driver. Changes since v1: - Read BLC_PWM_CPU_CTL2 to cpu_ctl2. - Clean up cpu_mode if slightly. - Always disable BLM_PWM_ENABLE in cpu_ctl2. Signed-off-by: Maarten Lankhorst Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108225 Cc: Basil Eric Rabi Cc: Hans de Goede Cc: Tolga Cakir Cc: Ville Syrjälä Tested-by: Tolga Cakir --- drivers/gpu/drm/i915/intel_panel.c | 40 +++++++++++++++++++++++++++--- 1 file changed, 36 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c index 39b9717ac36a..49c516e33df6 100644 --- a/drivers/gpu/drm/i915/intel_panel.c +++ b/drivers/gpu/drm/i915/intel_panel.c @@ -1484,8 +1484,8 @@ static int lpt_setup_backlight(struct intel_connector *connector, enum pipe unus { struct drm_i915_private *dev_priv = to_i915(connector->base.dev); struct intel_panel *panel = &connector->panel; - u32 pch_ctl1, pch_ctl2, val; - bool alt; + u32 cpu_ctl2, pch_ctl1, pch_ctl2, val; + bool alt, cpu_mode; if (HAS_PCH_LPT(dev_priv)) alt = I915_READ(SOUTH_CHICKEN2) & LPT_PWM_GRANULARITY; @@ -1499,6 +1499,8 @@ static int lpt_setup_backlight(struct intel_connector *connector, enum pipe unus pch_ctl2 = I915_READ(BLC_PWM_PCH_CTL2); panel->backlight.max = pch_ctl2 >> 16; + cpu_ctl2 = I915_READ(BLC_PWM_CPU_CTL2); + if (!panel->backlight.max) panel->backlight.max = get_backlight_max_vbt(connector); @@ -1507,12 +1509,42 @@ static int lpt_setup_backlight(struct intel_connector *connector, enum pipe unus panel->backlight.min = get_backlight_min_vbt(connector); - val = lpt_get_backlight(connector); + panel->backlight.enabled = pch_ctl1 & BLM_PCH_PWM_ENABLE; + + cpu_mode = panel->backlight.enabled && HAS_PCH_LPT(dev_priv) && + !(pch_ctl1 & BLM_PCH_OVERRIDE_ENABLE) && + (cpu_ctl2 & BLM_PWM_ENABLE); + if (cpu_mode) { + u32 freq; + + /* + * We're in cpu mode, convert to PCH units. + * + * Convert CPU pwm tick back to hz, back to new PCH units again. + * this is the same formula as pch_hz_to_pwm, but the other way + * around.. + */ + val = pch_get_backlight(connector); + freq = DIV_ROUND_CLOSEST(KHz(dev_priv->rawclk_freq), val * 128); + + DRM_DEBUG_KMS("Backlight PCH value: %u, converted to freq %u, converted to lpt units %u, minmax: %u/%u\n", + val, freq, lpt_hz_to_pwm(connector, freq), panel->backlight.min, panel->backlight.max); + + val = lpt_hz_to_pwm(connector, freq); + } else + val = lpt_get_backlight(connector); val = intel_panel_compute_brightness(connector, val); panel->backlight.level = clamp(val, panel->backlight.min, panel->backlight.max); - panel->backlight.enabled = pch_ctl1 & BLM_PCH_PWM_ENABLE; + if (cpu_mode) { + /* Write converted CPU PWM value to PCH override register */ + lpt_set_backlight(connector->base.state, panel->backlight.level); + I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1 | BLM_PCH_OVERRIDE_ENABLE); + } + + if (cpu_ctl2 & BLM_PWM_ENABLE) + I915_WRITE(BLC_PWM_CPU_CTL2, cpu_ctl2 & ~BLM_PWM_ENABLE); return 0; }