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 X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CC073C433E3 for ; Mon, 27 Jul 2020 20:03:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AEB182072E for ; Mon, 27 Jul 2020 20:03:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727032AbgG0UD2 (ORCPT ); Mon, 27 Jul 2020 16:03:28 -0400 Received: from asavdk3.altibox.net ([109.247.116.14]:44580 "EHLO asavdk3.altibox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727837AbgG0UD1 (ORCPT ); Mon, 27 Jul 2020 16:03:27 -0400 Received: from ravnborg.org (unknown [188.228.123.71]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by asavdk3.altibox.net (Postfix) with ESMTPS id 79BA32002B; Mon, 27 Jul 2020 22:03:21 +0200 (CEST) Date: Mon, 27 Jul 2020 22:03:20 +0200 From: Sam Ravnborg To: Paul Cercueil Cc: Thierry Reding , David Airlie , Daniel Vetter , Rob Herring , Andrzej Hajda , Neil Armstrong , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Noralf =?iso-8859-1?Q?Tr=F8nnes?= , od@zcrc.me, dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/6] drm: dsi: Let host and device specify supported bus Message-ID: <20200727200320.GA1014103@ravnborg.org> References: <20200727164613.19744-1-paul@crapouillou.net> <20200727164613.19744-3-paul@crapouillou.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200727164613.19744-3-paul@crapouillou.net> X-CMAE-Score: 0 X-CMAE-Analysis: v=2.3 cv=f+hm+t6M c=1 sm=1 tr=0 a=S6zTFyMACwkrwXSdXUNehg==:117 a=S6zTFyMACwkrwXSdXUNehg==:17 a=kj9zAlcOel0A:10 a=ER_8r6IbAAAA:8 a=mj1frrxOal-xCd-NJWkA:9 a=kvZZqAbxeRUPa8gG:21 a=D4JMFfri3F8EuTwx:21 a=CjuIK1q_8ugA:10 a=9LHmKk7ezEChjTCyhBa9:22 Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Hi Paul. On Mon, Jul 27, 2020 at 06:46:09PM +0200, Paul Cercueil wrote: > The current MIPI DSI framework can very well be used to support MIPI DBI > panels. In order to add support for the various bus types supported by > DBI, the DRM panel drivers should specify the bus type they will use, > and the DSI host drivers should specify the bus types they are > compatible with. > > The DSI host driver can then use the information provided by the DBI/DSI > device driver, such as the bus type and the number of lanes, to > configure its hardware properly. > > Signed-off-by: Paul Cercueil > --- > drivers/gpu/drm/drm_mipi_dsi.c | 9 +++++++++ > include/drm/drm_mipi_dsi.h | 12 ++++++++++++ > 2 files changed, 21 insertions(+) > > diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c > index 5dd475e82995..11ef885de765 100644 > --- a/drivers/gpu/drm/drm_mipi_dsi.c > +++ b/drivers/gpu/drm/drm_mipi_dsi.c > @@ -281,6 +281,9 @@ int mipi_dsi_host_register(struct mipi_dsi_host *host) > { > struct device_node *node; > > + if (WARN_ON_ONCE(!host->bus_types)) > + host->bus_types = MIPI_DEVICE_TYPE_DSI; > + So all 14 users need to specify bus_types. Seems doable. > for_each_available_child_of_node(host->dev->of_node, node) { > /* skip nodes without reg property */ > if (!of_find_property(node, "reg", NULL)) > @@ -323,6 +326,12 @@ int mipi_dsi_attach(struct mipi_dsi_device *dsi) > { > const struct mipi_dsi_host_ops *ops = dsi->host->ops; > > + if (WARN_ON_ONCE(!dsi->bus_type)) > + dsi->bus_type = MIPI_DEVICE_TYPE_DSI; We have ~50 users of mipi_dsi_attach() - doable. But a bit more work. > + > + if (!(dsi->bus_type & dsi->host->bus_types)) > + return -EINVAL; > + > if (!ops || !ops->attach) > return -ENOSYS; > > diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h > index 360e6377e84b..65d2961fc054 100644 > --- a/include/drm/drm_mipi_dsi.h > +++ b/include/drm/drm_mipi_dsi.h > @@ -63,6 +63,14 @@ struct mipi_dsi_packet { > int mipi_dsi_create_packet(struct mipi_dsi_packet *packet, > const struct mipi_dsi_msg *msg); > > +/* MIPI bus types */ If you define this as an enum then kernel-doc syntax will be picked up. See for example: enum drm_driver_feature > +#define MIPI_DEVICE_TYPE_DSI BIT(0) > +#define MIPI_DEVICE_TYPE_DBI_SPI_MODE1 BIT(1) > +#define MIPI_DEVICE_TYPE_DBI_SPI_MODE2 BIT(2) > +#define MIPI_DEVICE_TYPE_DBI_SPI_MODE3 BIT(3) > +#define MIPI_DEVICE_TYPE_DBI_M6800 BIT(4) > +#define MIPI_DEVICE_TYPE_DBI_I8080 BIT(5) > + > /** > * struct mipi_dsi_host_ops - DSI bus operations > * @attach: attach DSI device to DSI host > @@ -94,11 +102,13 @@ struct mipi_dsi_host_ops { > * struct mipi_dsi_host - DSI host device > * @dev: driver model device node for this DSI host > * @ops: DSI host operations > + * @bus_types: Bitmask of supported MIPI bus types Please add some kind of reference to MIPI_DEVICE_TYPE_* - so the reader knows for sure this is the bits used here. > * @list: list management > */ > struct mipi_dsi_host { > struct device *dev; > const struct mipi_dsi_host_ops *ops; > + unsigned int bus_types; Use u32. Shorter and we know this is 32 bits wide. > struct list_head list; > }; > > @@ -162,6 +172,7 @@ struct mipi_dsi_device_info { > * @host: DSI host for this peripheral > * @dev: driver model device node for this peripheral > * @name: DSI peripheral chip type > + * @bus_type: MIPI bus type (MIPI_DEVICE_TYPE_DSI/...) > * @channel: virtual channel assigned to the peripheral > * @format: pixel format for video mode > * @lanes: number of active data lanes > @@ -178,6 +189,7 @@ struct mipi_dsi_device { > struct device dev; > > char name[DSI_DEV_NAME_SIZE]; > + unsigned int bus_type; Use u32. > unsigned int channel; > unsigned int lanes; > enum mipi_dsi_pixel_format format; > -- > 2.27.0