From patchwork Mon Jul 8 15:01:14 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marek Vasut X-Patchwork-Id: 13726706 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 48ADCC3DA47 for ; Mon, 8 Jul 2024 15:01:52 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 3033310E376; Mon, 8 Jul 2024 15:01:51 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=denx.de header.i=@denx.de header.b="dI4N87sH"; dkim-atps=neutral Received: from phobos.denx.de (phobos.denx.de [85.214.62.61]) by gabe.freedesktop.org (Postfix) with ESMTPS id D310010E360 for ; Mon, 8 Jul 2024 15:01:48 +0000 (UTC) Received: from tr.lan (ip-86-49-120-218.bb.vodafone.cz [86.49.120.218]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: marex@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id B9D1D88730; Mon, 8 Jul 2024 17:01:46 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1720450907; bh=kzsN2CVcmen8q9agco8seR/ZLvEkcv55kH+IiDUqMzQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dI4N87sH2/cR4OFvIOmZO2bevVD8rTGunPzSCPAySNB0FTWIXmLPpwAu11DaxuiuM QyeW2JBitKVDz6LUj60u1pF1Ibq6POnCZonY94/w+cNFMmUZ9afgosCwVzcL2itZJ8 /9fR2iOZRcz/DzDfLQYIT6ncL64+CcQkoNTzhWDRGJoouPwgomEPA4k6ixEbmrxIEJ BD4q9El0oHAmDagw0NKzZnjTaGwa+J7N/ruElNqC3sB0Gx6J7+omY0btu/XCY6M/eE gd68kkLYhiRpH/EoDOyYtQwjF710D7KsybOKj89cv5im/wffM77leeBgYua/ZEfGRS vNNtNEvHWZ3Rg== From: Marek Vasut To: dri-devel@lists.freedesktop.org Cc: Marek Vasut , Alexander Stein , Andrzej Hajda , Conor Dooley , Daniel Vetter , David Airlie , Jernej Skrabec , Jonas Karlman , Krzysztof Kozlowski , Laurent Pinchart , Lucas Stach , Maarten Lankhorst , Maxime Ripard , Neil Armstrong , Rob Herring , Robert Foss , Thomas Zimmermann , devicetree@vger.kernel.org, kernel@dh-electronics.com Subject: [PATCH v4 2/2] drm/bridge: tc358767: Add configurable default preemphasis Date: Mon, 8 Jul 2024 17:01:14 +0200 Message-ID: <20240708150130.54484-2-marex@denx.de> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240708150130.54484-1-marex@denx.de> References: <20240708150130.54484-1-marex@denx.de> MIME-Version: 1.0 X-Virus-Scanned: clamav-milter 0.103.8 at phobos.denx.de X-Virus-Status: Clean X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Make the default DP port preemphasis configurable via new DT property "toshiba,pre-emphasis". This is useful in case the DP link properties are known and starting link training from preemphasis setting of 0 dB is not useful. The preemphasis can be set separately for both DP lanes in range 0=0dB, 1=3.5dB, 2=6dB . Acked-by: Alexander Stein Signed-off-by: Marek Vasut --- Cc: Alexander Stein Cc: Andrzej Hajda Cc: Conor Dooley Cc: Daniel Vetter Cc: David Airlie Cc: Jernej Skrabec Cc: Jonas Karlman Cc: Krzysztof Kozlowski Cc: Laurent Pinchart Cc: Lucas Stach Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Neil Armstrong Cc: Rob Herring Cc: Robert Foss Cc: Thomas Zimmermann Cc: devicetree@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: kernel@dh-electronics.com --- V2: - Parse toshiba,pre-emphasis property out of an endpoint of port 2 (the DP port) V3: - No change V4: - Invert the if (endpoint.port == 2) conditional in tc_probe_bridge_endpoint() - Add AB from Alexander --- drivers/gpu/drm/bridge/tc358767.c | 45 ++++++++++++++++++++++++++----- 1 file changed, 38 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c index dde1b2734c98a..a13e4898a210c 100644 --- a/drivers/gpu/drm/bridge/tc358767.c +++ b/drivers/gpu/drm/bridge/tc358767.c @@ -241,6 +241,10 @@ /* Link Training */ #define DP0_SRCCTRL 0x06a0 +#define DP0_SRCCTRL_PRE1 GENMASK(29, 28) +#define DP0_SRCCTRL_SWG1 GENMASK(25, 24) +#define DP0_SRCCTRL_PRE0 GENMASK(21, 20) +#define DP0_SRCCTRL_SWG0 GENMASK(17, 16) #define DP0_SRCCTRL_SCRMBLDIS BIT(13) #define DP0_SRCCTRL_EN810B BIT(12) #define DP0_SRCCTRL_NOTP (0 << 8) @@ -278,6 +282,8 @@ #define AUDIFDATA6 0x0720 /* DP0 Audio Info Frame Bytes 27 to 24 */ #define DP1_SRCCTRL 0x07a0 /* DP1 Control Register */ +#define DP1_SRCCTRL_PRE GENMASK(21, 20) +#define DP1_SRCCTRL_SWG GENMASK(17, 16) /* PHY */ #define DP_PHY_CTRL 0x0800 @@ -369,6 +375,7 @@ struct tc_data { u32 rev; u8 assr; + u8 pre_emphasis[2]; struct gpio_desc *sd_gpio; struct gpio_desc *reset_gpio; @@ -1090,13 +1097,17 @@ static int tc_main_link_enable(struct tc_data *tc) return ret; } - ret = regmap_write(tc->regmap, DP0_SRCCTRL, tc_srcctrl(tc)); + ret = regmap_write(tc->regmap, DP0_SRCCTRL, + tc_srcctrl(tc) | + FIELD_PREP(DP0_SRCCTRL_PRE0, tc->pre_emphasis[0]) | + FIELD_PREP(DP0_SRCCTRL_PRE1, tc->pre_emphasis[1])); if (ret) return ret; /* SSCG and BW27 on DP1 must be set to the same as on DP0 */ ret = regmap_write(tc->regmap, DP1_SRCCTRL, (tc->link.spread ? DP0_SRCCTRL_SSCG : 0) | - ((tc->link.rate != 162000) ? DP0_SRCCTRL_BW27 : 0)); + ((tc->link.rate != 162000) ? DP0_SRCCTRL_BW27 : 0) | + FIELD_PREP(DP1_SRCCTRL_PRE, tc->pre_emphasis[1])); if (ret) return ret; @@ -1188,8 +1199,10 @@ static int tc_main_link_enable(struct tc_data *tc) goto err_dpcd_write; /* Reset voltage-swing & pre-emphasis */ - tmp[0] = tmp[1] = DP_TRAIN_VOLTAGE_SWING_LEVEL_0 | - DP_TRAIN_PRE_EMPH_LEVEL_0; + tmp[0] = DP_TRAIN_VOLTAGE_SWING_LEVEL_0 | + FIELD_PREP(DP_TRAIN_PRE_EMPHASIS_MASK, tc->pre_emphasis[0]); + tmp[1] = DP_TRAIN_VOLTAGE_SWING_LEVEL_0 | + FIELD_PREP(DP_TRAIN_PRE_EMPHASIS_MASK, tc->pre_emphasis[1]); ret = drm_dp_dpcd_write(aux, DP_TRAINING_LANE0_SET, tmp, 2); if (ret < 0) goto err_dpcd_write; @@ -1213,7 +1226,9 @@ static int tc_main_link_enable(struct tc_data *tc) ret = regmap_write(tc->regmap, DP0_SRCCTRL, tc_srcctrl(tc) | DP0_SRCCTRL_SCRMBLDIS | DP0_SRCCTRL_AUTOCORRECT | - DP0_SRCCTRL_TP1); + DP0_SRCCTRL_TP1 | + FIELD_PREP(DP0_SRCCTRL_PRE0, tc->pre_emphasis[0]) | + FIELD_PREP(DP0_SRCCTRL_PRE1, tc->pre_emphasis[1])); if (ret) return ret; @@ -1248,7 +1263,9 @@ static int tc_main_link_enable(struct tc_data *tc) ret = regmap_write(tc->regmap, DP0_SRCCTRL, tc_srcctrl(tc) | DP0_SRCCTRL_SCRMBLDIS | DP0_SRCCTRL_AUTOCORRECT | - DP0_SRCCTRL_TP2); + DP0_SRCCTRL_TP2 | + FIELD_PREP(DP0_SRCCTRL_PRE0, tc->pre_emphasis[0]) | + FIELD_PREP(DP0_SRCCTRL_PRE1, tc->pre_emphasis[1])); if (ret) return ret; @@ -1274,7 +1291,9 @@ static int tc_main_link_enable(struct tc_data *tc) /* Clear Training Pattern, set AutoCorrect Mode = 1 */ ret = regmap_write(tc->regmap, DP0_SRCCTRL, tc_srcctrl(tc) | - DP0_SRCCTRL_AUTOCORRECT); + DP0_SRCCTRL_AUTOCORRECT | + FIELD_PREP(DP0_SRCCTRL_PRE0, tc->pre_emphasis[0]) | + FIELD_PREP(DP0_SRCCTRL_PRE1, tc->pre_emphasis[1])); if (ret) return ret; @@ -2435,6 +2454,18 @@ static int tc_probe_bridge_endpoint(struct tc_data *tc) return -EINVAL; } mode |= BIT(endpoint.port); + + if (endpoint.port == 2) { + of_property_read_u8_array(node, "toshiba,pre-emphasis", + tc->pre_emphasis, + ARRAY_SIZE(tc->pre_emphasis)); + + if (tc->pre_emphasis[0] < 0 || tc->pre_emphasis[0] > 2 || + tc->pre_emphasis[1] < 0 || tc->pre_emphasis[1] > 2) { + dev_err(dev, "Incorrect Pre-Emphasis setting, use either 0=0dB 1=3.5dB 2=6dB\n"); + return -EINVAL; + } + } } if (mode == mode_dpi_to_edp || mode == mode_dpi_to_dp) {