From patchwork Thu Apr 27 14:29:33 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Francesco Dolcini X-Patchwork-Id: 13225539 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 725BCC77B73 for ; Thu, 27 Apr 2023 14:30:24 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id DE7D410EB56; Thu, 27 Apr 2023 14:30:23 +0000 (UTC) Received: from mail11.truemail.it (mail11.truemail.it [217.194.8.81]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3A80A10EB33 for ; Thu, 27 Apr 2023 14:29:46 +0000 (UTC) Received: from francesco-nb.pivistrello.it (93-49-2-63.ip317.fastwebnet.it [93.49.2.63]) by mail11.truemail.it (Postfix) with ESMTPA id 2F95C20B61; Thu, 27 Apr 2023 16:29:43 +0200 (CEST) From: Francesco Dolcini To: Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , tomi.valkeinen@ideasonboard.com, dri-devel@lists.freedesktop.org Subject: [PATCH v1 8/9] drm/bridge: tc358768: fix THS_TRAILCNT computation Date: Thu, 27 Apr 2023 16:29:33 +0200 Message-Id: <20230427142934.55435-9-francesco@dolcini.it> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230427142934.55435-1-francesco@dolcini.it> References: <20230427142934.55435-1-francesco@dolcini.it> MIME-Version: 1.0 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: , Cc: Francesco Dolcini , linux-kernel@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Francesco Dolcini Correct computation of THS_TRAILCNT register. This register must be set to a value that ensure that THS_TRAIL > 60 ns + 4 x UI and THS_TRAIL > 8 x UI and THS_TRAIL < TEOT with TEOT = 105 ns + (12 x UI) with the actual value of THS_TRAIL being (1 + THS_TRAILCNT) x ByteClk cycle + ((1 to 2) + 2) xHSBYTECLK cycle + - (PHY output delay) with PHY output delay being about (8 + (5 to 6)) x MIPIBitClk cycle in the BitClk conversion. Fixes: ff1ca6397b1d ("drm/bridge: Add tc358768 driver") Signed-off-by: Francesco Dolcini Reviewed-by: Robert Foss --- drivers/gpu/drm/bridge/tc358768.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/bridge/tc358768.c b/drivers/gpu/drm/bridge/tc358768.c index 854fc04f08d0..947c7dca567a 100644 --- a/drivers/gpu/drm/bridge/tc358768.c +++ b/drivers/gpu/drm/bridge/tc358768.c @@ -779,9 +779,10 @@ static void tc358768_bridge_pre_enable(struct drm_bridge *bridge) dev_dbg(priv->dev, "TCLK_POSTCNT: 0x%x\n", val); tc358768_write(priv, TC358768_TCLK_POSTCNT, val); - /* 60ns + 4*UI < THS_PREPARE < 105ns + 12*UI */ - val = tc358768_ns_to_cnt(60 + tc358768_to_ns(15 * ui_nsk), - dsibclk_nsk) - 5; + /* max(60ns + 4*UI, 8*UI) < THS_TRAILCNT < 105ns + 12*UI */ + raw_val = tc358768_ns_to_cnt(60 + tc358768_to_ns(18 * ui_nsk), + dsibclk_nsk) - 4; + val = clamp(raw_val, 0, 15); dev_dbg(priv->dev, "THS_TRAILCNT: 0x%x\n", val); tc358768_write(priv, TC358768_THS_TRAILCNT, val);