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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AEA19C43334 for ; Tue, 7 Jun 2022 12:46:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244144AbiFGMqk (ORCPT ); Tue, 7 Jun 2022 08:46:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32804 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242948AbiFGMqj (ORCPT ); Tue, 7 Jun 2022 08:46:39 -0400 Received: from mailgw01.mediatek.com (unknown [60.244.123.138]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0C692C966A; Tue, 7 Jun 2022 05:46:37 -0700 (PDT) X-UUID: 4536014a1aa64cfc89fa6006743de399-20220607 X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.5,REQID:e63a083f-6cd4-4694-9894-e2fb43d438b0,OB:0,LO B:0,IP:0,URL:0,TC:0,Content:0,EDM:0,RT:0,SF:45,FILE:0,RULE:Release_Ham,ACT ION:release,TS:45 X-CID-INFO: VERSION:1.1.5,REQID:e63a083f-6cd4-4694-9894-e2fb43d438b0,OB:0,LOB: 0,IP:0,URL:0,TC:0,Content:0,EDM:0,RT:0,SF:45,FILE:0,RULE:Release_Ham,ACTIO N:release,TS:45 X-CID-META: VersionHash:2a19b09,CLOUDID:3d317e7e-c8dc-403a-96e8-6237210dceee,C OID:1fd60574827d,Recheck:0,SF:28|17|19|48,TC:nil,Content:0,EDM:-3,IP:nil,U RL:0,File:nil,QS:0,BEC:nil X-UUID: 4536014a1aa64cfc89fa6006743de399-20220607 Received: from mtkmbs10n1.mediatek.inc [(172.21.101.34)] by mailgw01.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 727649322; Tue, 07 Jun 2022 20:46:33 +0800 Received: from mtkmbs11n2.mediatek.inc (172.21.101.187) 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; Tue, 7 Jun 2022 20:46:31 +0800 Received: from mtksdccf07 (172.21.84.99) by mtkmbs11n2.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.792.3 via Frontend Transport; Tue, 7 Jun 2022 20:46:31 +0800 Message-ID: Subject: Re: [PATCH v10 18/21] drm/mediatek: Add mt8195 Embedded DisplayPort driver From: Rex-BC Chen To: CK Hu , 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 =?UTF-8?Q?=28=E4=BA=91=E6=98=A5=E5=B3=B0=29?= , Kishon Vijay Abraham I , Vinod Koul , Helge Deller , Jitao Shi =?UTF-8?Q?=28=E7=9F=B3=E8=AE=B0=E6=B6=9B=29?= CC: Markus Schneider-Pargmann , "dri-devel@lists.freedesktop.org" , "linux-mediatek@lists.infradead.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-phy@lists.infradead.org" , "linux-fbdev@vger.kernel.org" Date: Tue, 7 Jun 2022 20:46:31 +0800 In-Reply-To: References: <20220523104758.29531-1-granquet@baylibre.com> <20220523104758.29531-19-granquet@baylibre.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.2 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org On Tue, 2022-06-07 at 15:30 +0800, CK Hu wrote: > 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 ssize_t mtk_dp_aux_transfer(struct drm_dp_aux *mtk_aux, > > + struct drm_dp_aux_msg *msg) > > +{ > > + struct mtk_dp *mtk_dp; > > + bool is_read; > > + u8 request; > > + size_t accessed_bytes = 0; > > + int ret = 0; > > + > > + mtk_dp = container_of(mtk_aux, struct mtk_dp, aux); > > + > > + if (!mtk_dp->train_info.cable_plugged_in || > > + mtk_dp->train_info.irq_status & MTK_DP_HPD_DISCONNECT) { > > + mtk_dp->train_state = MTK_DP_TRAIN_STATE_CHECKCAP; > > Changing state here has no any effect, so drop this. > ok, I will drop it. > > + return -EAGAIN; > > + } > > + > > + switch (msg->request) { > > + case DP_AUX_I2C_MOT: > > + case DP_AUX_I2C_WRITE: > > + case DP_AUX_NATIVE_WRITE: > > + case DP_AUX_I2C_WRITE_STATUS_UPDATE: > > + case DP_AUX_I2C_WRITE_STATUS_UPDATE | DP_AUX_I2C_MOT: > > + request = msg->request & > > ~DP_AUX_I2C_WRITE_STATUS_UPDATE; > > + is_read = false; > > + break; > > + case DP_AUX_I2C_READ: > > + case DP_AUX_NATIVE_READ: > > + case DP_AUX_I2C_READ | DP_AUX_I2C_MOT: > > + request = msg->request; > > + is_read = true; > > + break; > > + default: > > + drm_err(mtk_aux->drm_dev, "invalid aux cmd = %d\n", > > + msg->request); > > + return -EINVAL; > > + } > > + > > + if (msg->size == 0) { > > + ret = mtk_dp_aux_do_transfer(mtk_dp, is_read, request, > > + msg->address + > > accessed_bytes, > > + msg->buffer + > > accessed_bytes, 0); > > + } else { > > + while (accessed_bytes < msg->size) { > > + size_t to_access = > > + min_t(size_t, DP_AUX_MAX_PAYLOAD_BYTES, > > + msg->size - accessed_bytes); > > + > > + ret = mtk_dp_aux_do_transfer(mtk_dp, > > + is_read, request, > > + msg->address + > > accessed_bytes, > > + msg->buffer + > > accessed_bytes, > > + to_access); > > + > > + if (ret) { > > + drm_info(mtk_dp->drm_dev, > > + "Failed to do AUX transfer: > > %d\n", ret); > > + break; > > + } > > + accessed_bytes += to_access; > > + } > > + } > > + > > + if (ret) { > > + msg->reply = DP_AUX_NATIVE_REPLY_NACK | > > DP_AUX_I2C_REPLY_NACK; > > + return ret; > > + } > > + > > + msg->reply = DP_AUX_NATIVE_REPLY_ACK | DP_AUX_I2C_REPLY_ACK; > > + return msg->size; > > +} > >