From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 74240C43334 for ; Wed, 8 Jun 2022 09:01:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Date:CC:To:From:Subject:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=CTTy1tsoHKX02ZXvxhlIEQM2b2vOM29gipZRBEStTzo=; b=LtEb6pnyvJED3e 3+J9BHFoCvaMkj81QFKr3brR5hmh4Z2J/+ixk8c5hCENL7SgsEc+oLuYM84zI4Dp5AnfrsQAQN95s v/BaZ8gBX0WjPDTM4Rye8MOcgOAP0ibXAwuXuRuYLrsQ+LQcm+91PRfnX9dtDDUorI+LYiXj1eG/q qYaHKBWqa39pmUS4Xrv5x6VlvmUHOt5FArkt07GFuf5JufatSfYXORrEMRtUa8iI1q+cyO+aso8HF ADgN0UoUT4RWngLcXuK66W8NBmPCVcHJBvUwc3LHrC03KvOvJGQxIibWi9TR+0Lr1ZX93LvzwF2By wJq6puMU7wHPvJ0zxWVw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nyrZb-00CBbz-JK; Wed, 08 Jun 2022 09:01:55 +0000 Received: from mailgw02.mediatek.com ([216.200.240.185]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nyrKL-00C4bK-8P; Wed, 08 Jun 2022 08:46:10 +0000 X-UUID: 97e47547641d43a6adb2f322e5b73c6e-20220608 X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.5,REQID:508215b0-0358-4d44-a996-10c88cc2e106,OB:0,LO B:0,IP:0,URL:0,TC:0,Content:0,EDM:0,RT:0,SF:0,FILE:0,RULE:Release_Ham,ACTI ON:release,TS:0 X-CID-META: VersionHash:2a19b09,CLOUDID:ecad15e5-2ba2-4dc1-b6c5-11feb6c769e0,C OID:IGNORED,Recheck:0,SF:nil,TC:nil,Content:0,EDM:-3,IP:nil,URL:0,File:nil ,QS:0,BEC:nil X-UUID: 97e47547641d43a6adb2f322e5b73c6e-20220608 Received: from mtkcas66.mediatek.inc [(172.29.193.44)] by mailgw02.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 302064904; Wed, 08 Jun 2022 01:46:04 -0700 Received: from mtkmbs11n1.mediatek.inc (172.21.101.185) by MTKMBS62N2.mediatek.inc (172.29.193.42) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 8 Jun 2022 01:45:15 -0700 Received: from mtkmbs11n1.mediatek.inc (172.21.101.185) by mtkmbs11n1.mediatek.inc (172.21.101.185) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.792.3; Wed, 8 Jun 2022 16:45:14 +0800 Received: from mtksdccf07 (172.21.84.99) by mtkmbs11n1.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.792.3 via Frontend Transport; Wed, 8 Jun 2022 16:45:14 +0800 Message-ID: <8bd5136b1404e16ba5085c3151b31ec9a1715e54.camel@mediatek.com> Subject: Re: [PATCH v10 18/21] drm/mediatek: Add mt8195 Embedded DisplayPort driver From: CK Hu To: Rex-BC Chen , Guillaume Ranquet , Chun-Kuang Hu , "Philipp Zabel" , David Airlie , "Daniel Vetter" , Rob Herring , "Krzysztof Kozlowski" , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Matthias Brugger , Chunfeng Yun , "Kishon Vijay Abraham I" , Vinod Koul , "Helge Deller" , Jitao shi CC: Markus Schneider-Pargmann , , , , , , , Date: Wed, 8 Jun 2022 16:45:14 +0800 In-Reply-To: <20220523104758.29531-19-granquet@baylibre.com> References: <20220523104758.29531-1-granquet@baylibre.com> <20220523104758.29531-19-granquet@baylibre.com> X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.2 MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220608_014609_362020_5B9688FD X-CRM114-Status: GOOD ( 23.66 ) X-BeenThere: linux-phy@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux Phy Mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-phy" Errors-To: linux-phy-bounces+linux-phy=archiver.kernel.org@lists.infradead.org Hi, Rex: On Mon, 2022-05-23 at 12:47 +0200, Guillaume Ranquet wrote: > From: Markus Schneider-Pargmann > > This patch adds a DisplayPort driver for the Mediatek mt8195 SoC. > > It supports the mt8195, the embedded DisplayPort units. It offers > DisplayPort 1.4 with up to 4 lanes. > > The driver creates a child device for the phy. The child device will > never exist without the parent being active. As they are sharing a > register range, the parent passes a regmap pointer to the child so > that > both can work with the same register range. The phy driver sets > device > data that is read by the parent to get the phy device that can be > used > to control the phy properties. > > This driver is based on an initial version by > Jason-JH.Lin . > > Signed-off-by: Markus Schneider-Pargmann > Signed-off-by: Guillaume Ranquet > --- [snip] > + > +static bool mtk_dp_set_swing_pre_emphasis(struct mtk_dp *mtk_dp, int > lane_num, > + int swing_val, int > preemphasis) The return value is never processed, so let this function to be void. Regards, CK > +{ > + int ret; > + > + u32 lane_shift = lane_num * DP_TX1_VOLT_SWING_SHIFT; > + > + if (lane_num < 0 || lane_num > 3) lane_num < 0 would not happen. lane_num > 3 only if device tree max lane is wrong. So I would like to checkout max lane when parsing device tree instead of checking here. > + return false; > + > + dev_dbg(mtk_dp->dev, > + "link training swing_val= 0x%x, preemphasis = 0x%x\n", > + swing_val, preemphasis); > + > + ret = mtk_dp_update_bits(mtk_dp, MTK_DP_TOP_SWING_EMP, > + swing_val << (DP_TX0_VOLT_SWING_SHIFT > + lane_shift), > + DP_TX0_VOLT_SWING_MASK << lane_shift); > + if (ret) > + return ret; > + ret = mtk_dp_update_bits(mtk_dp, MTK_DP_TOP_SWING_EMP, > + preemphasis << (DP_TX0_PRE_EMPH_SHIFT > + lane_shift), > + DP_TX0_PRE_EMPH_MASK << lane_shift); > + > + return !ret; > +} > + -- linux-phy mailing list linux-phy@lists.infradead.org https://lists.infradead.org/mailman/listinfo/linux-phy