From patchwork Tue May 28 08:27:39 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomi Valkeinen X-Patchwork-Id: 10964149 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 1AE9D933 for ; Tue, 28 May 2019 08:28:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0AC7E286A8 for ; Tue, 28 May 2019 08:28:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F23CB286BD; Tue, 28 May 2019 08:28:57 +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 6E06D286A8 for ; Tue, 28 May 2019 08:28:57 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id DA79B89C83; Tue, 28 May 2019 08:28:55 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from fllv0015.ext.ti.com (fllv0015.ext.ti.com [198.47.19.141]) by gabe.freedesktop.org (Postfix) with ESMTPS id 940F889D02 for ; Tue, 28 May 2019 08:28:47 +0000 (UTC) Received: from lelv0266.itg.ti.com ([10.180.67.225]) by fllv0015.ext.ti.com (8.15.2/8.15.2) with ESMTP id x4S8Sh9c125353; Tue, 28 May 2019 03:28:43 -0500 Received: from DLEE105.ent.ti.com (dlee105.ent.ti.com [157.170.170.35]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id x4S8ShsE115108 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 28 May 2019 03:28:43 -0500 Received: from DLEE108.ent.ti.com (157.170.170.38) by DLEE105.ent.ti.com (157.170.170.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5; Tue, 28 May 2019 03:28:42 -0500 Received: from lelv0327.itg.ti.com (10.180.67.183) by DLEE108.ent.ti.com (157.170.170.38) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5 via Frontend Transport; Tue, 28 May 2019 03:28:42 -0500 Received: from deskari.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0327.itg.ti.com (8.15.2/8.15.2) with ESMTP id x4S8Rxuk125039; Tue, 28 May 2019 03:28:40 -0500 From: Tomi Valkeinen To: , Andrzej Hajda , Laurent Pinchart , Lucas Stach , Andrey Gusakov , Philipp Zabel , Andrey Smirnov , Peter Ujfalusi , Jyri Sarha , Benoit Parrot Subject: [PATCHv4 16/24] drm/bridge: tc358767: clean-up link training Date: Tue, 28 May 2019 11:27:39 +0300 Message-ID: <20190528082747.3631-17-tomi.valkeinen@ti.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190528082747.3631-1-tomi.valkeinen@ti.com> References: <20190528082747.3631-1-tomi.valkeinen@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 X-Mailman-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1559032123; bh=HagT0eq2gfjYNqJ2BnYyRsURVlC8Q50Jma7y0ziV7Ms=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=As8ojXEmJfPp4hmywxK31S254UX9PjNoL9upR15wTDDn3Cq8jkpt4AQBsj7qJKwt0 cIR3tplj02rp3UAIGkgeftCSYaXPwu0VjPWc99SwUPIikXvbzGPhoUFTF8KH4S2ie1 iISgmZstg2p+zUm0mMDUV4GwIP+d7ZeLkP2PuDuo= 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: Tomi Valkeinen Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP The current link training code does unnecessary retry-loops, and does extra writes to the registers. It is easier to follow the flow and ensure it's similar to Toshiba's documentation if we deal with LT inside tc_main_link_enable() function. This patch adds tc_wait_link_training() which handles waiting for the LT phase to finish, and does the necessary LT register setups in tc_main_link_enable, without extra loops. Signed-off-by: Tomi Valkeinen Reviewed-by: Andrzej Hajda --- drivers/gpu/drm/bridge/tc358767.c | 136 +++++++++++++----------------- 1 file changed, 60 insertions(+), 76 deletions(-) diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c index d79b1d0ca0db..10a9b46de5f1 100644 --- a/drivers/gpu/drm/bridge/tc358767.c +++ b/drivers/gpu/drm/bridge/tc358767.c @@ -740,84 +740,24 @@ static int tc_set_video_mode(struct tc_data *tc, return ret; } -static int tc_link_training(struct tc_data *tc, int pattern) +static int tc_wait_link_training(struct tc_data *tc) { - const char * const *errors; - u32 srcctrl = tc_srcctrl(tc) | DP0_SRCCTRL_SCRMBLDIS | - DP0_SRCCTRL_AUTOCORRECT; - int timeout; - int retry; + u32 timeout = 1000; u32 value; int ret; - if (pattern == DP_TRAINING_PATTERN_1) { - srcctrl |= DP0_SRCCTRL_TP1; - errors = training_pattern1_errors; - } else { - srcctrl |= DP0_SRCCTRL_TP2; - errors = training_pattern2_errors; - } - - /* Set DPCD 0x102 for Training Part 1 or 2 */ - tc_write(DP0_SNKLTCTRL, DP_LINK_SCRAMBLING_DISABLE | pattern); - - tc_write(DP0_LTLOOPCTRL, - (0x0f << 28) | /* Defer Iteration Count */ - (0x0f << 24) | /* Loop Iteration Count */ - (0x0d << 0)); /* Loop Timer Delay */ - - retry = 5; do { - /* Set DP0 Training Pattern */ - tc_write(DP0_SRCCTRL, srcctrl); - - /* Enable DP0 to start Link Training */ - tc_write(DP0CTL, DP_EN); - - /* wait */ - timeout = 1000; - do { - tc_read(DP0_LTSTAT, &value); - udelay(1); - } while ((!(value & LT_LOOPDONE)) && (--timeout)); - if (timeout == 0) { - dev_err(tc->dev, "Link training timeout!\n"); - } else { - int pattern = (value >> 11) & 0x3; - int error = (value >> 8) & 0x7; - - dev_dbg(tc->dev, - "Link training phase %d done after %d uS: %s\n", - pattern, 1000 - timeout, errors[error]); - if (pattern == DP_TRAINING_PATTERN_1 && error == 0) - break; - if (pattern == DP_TRAINING_PATTERN_2) { - value &= LT_CHANNEL1_EQ_BITS | - LT_INTERLANE_ALIGN_DONE | - LT_CHANNEL0_EQ_BITS; - /* in case of two lanes */ - if ((tc->link.base.num_lanes == 2) && - (value == (LT_CHANNEL1_EQ_BITS | - LT_INTERLANE_ALIGN_DONE | - LT_CHANNEL0_EQ_BITS))) - break; - /* in case of one line */ - if ((tc->link.base.num_lanes == 1) && - (value == (LT_INTERLANE_ALIGN_DONE | - LT_CHANNEL0_EQ_BITS))) - break; - } - } - /* restart */ - tc_write(DP0CTL, 0); - usleep_range(10, 20); - } while (--retry); - if (retry == 0) { - dev_err(tc->dev, "Failed to finish training phase %d\n", - pattern); + udelay(1); + tc_read(DP0_LTSTAT, &value); + } while ((!(value & LT_LOOPDONE)) && (--timeout)); + + if (timeout == 0) { + dev_err(tc->dev, "Link training timeout waiting for LT_LOOPDONE!\n"); + return -ETIMEDOUT; } - return 0; + return (value >> 8) & 0x7; + err: return ret; } @@ -927,7 +867,7 @@ static int tc_main_link_enable(struct tc_data *tc) if (tmp[0] != tc->assr) { dev_dbg(dev, "Failed to switch display ASSR to %d, falling back to unscrambled mode\n", - tc->assr); + tc->assr); /* trying with disabled scrambler */ tc->link.scrambler_dis = true; } @@ -953,13 +893,57 @@ static int tc_main_link_enable(struct tc_data *tc) if (ret < 0) goto err_dpcd_write; - ret = tc_link_training(tc, DP_TRAINING_PATTERN_1); - if (ret) + /* Clock-Recovery */ + + /* Set DPCD 0x102 for Training Pattern 1 */ + tc_write(DP0_SNKLTCTRL, DP_LINK_SCRAMBLING_DISABLE | + DP_TRAINING_PATTERN_1); + + tc_write(DP0_LTLOOPCTRL, + (15 << 28) | /* Defer Iteration Count */ + (15 << 24) | /* Loop Iteration Count */ + (0xd << 0)); /* Loop Timer Delay */ + + tc_write(DP0_SRCCTRL, tc_srcctrl(tc) | DP0_SRCCTRL_SCRMBLDIS | + DP0_SRCCTRL_AUTOCORRECT | DP0_SRCCTRL_TP1); + + /* Enable DP0 to start Link Training */ + tc_write(DP0CTL, + ((tc->link.base.capabilities & DP_LINK_CAP_ENHANCED_FRAMING) ? EF_EN : 0) | + DP_EN); + + /* wait */ + ret = tc_wait_link_training(tc); + if (ret < 0) goto err; - ret = tc_link_training(tc, DP_TRAINING_PATTERN_2); - if (ret) + if (ret) { + dev_err(tc->dev, "Link training phase 1 failed: %s\n", + training_pattern1_errors[ret]); + ret = -ENODEV; goto err; + } + + /* Channel Equalization */ + + /* Set DPCD 0x102 for Training Pattern 2 */ + tc_write(DP0_SNKLTCTRL, DP_LINK_SCRAMBLING_DISABLE | + DP_TRAINING_PATTERN_2); + + tc_write(DP0_SRCCTRL, tc_srcctrl(tc) | DP0_SRCCTRL_SCRMBLDIS | + DP0_SRCCTRL_AUTOCORRECT | DP0_SRCCTRL_TP2); + + /* wait */ + ret = tc_wait_link_training(tc); + if (ret < 0) + goto err; + + if (ret) { + dev_err(tc->dev, "Link training phase 2 failed: %s\n", + training_pattern2_errors[ret]); + ret = -ENODEV; + goto err; + } /* * Toshiba's documentation suggests to first clear DPCD 0x102, then