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=-10.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 921FFC433E2 for ; Mon, 31 Aug 2020 20:44:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 69DA42054F for ; Mon, 31 Aug 2020 20:44:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="OhB1coHr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726537AbgHaUoC (ORCPT ); Mon, 31 Aug 2020 16:44:02 -0400 Received: from perceval.ideasonboard.com ([213.167.242.64]:46512 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726102AbgHaUoB (ORCPT ); Mon, 31 Aug 2020 16:44:01 -0400 Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id DBFBC277; Mon, 31 Aug 2020 22:43:58 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1598906639; bh=GWc1kc2ZYMRzT4RklTX/9TamGTAXwPTp8ETTg6O8suA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OhB1coHrSP/iW/x30PtlAPrlM5c0tj8EdwS5afCTsmXePE0nLEQ8cuBmfnewcJRPq NCn8Cw+vH8QuW0vmE+cH29aC5aT51ly/JqlYzr6YuXx9J95YZZrfMY+NYaVaLyN5v2 BA9iZ9lLrt1VPlIMprAdpgVyQn8kTNOfltTG7fW4= Date: Mon, 31 Aug 2020 23:43:37 +0300 From: Laurent Pinchart To: Maxime Ripard Cc: Chen-Yu Tsai , dri-devel@lists.freedesktop.org, Maarten Lankhorst , Thomas Zimmermann , Daniel Vetter , David Airlie , devicetree@vger.kernel.org, Mark Rutland , Rob Herring , Frank Rowand , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 3/4] drm/sun4i: tcon: Support the LVDS Dual-Link on the A20 Message-ID: <20200831204337.GW16155@pendragon.ideasonboard.com> References: <100f5fe3391366e9bbc76ebec1edbf8c0aeb715a.1596101672.git-series.maxime@cerno.tech> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <100f5fe3391366e9bbc76ebec1edbf8c0aeb715a.1596101672.git-series.maxime@cerno.tech> Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Hi Maxime, Thank you for the patch. On Thu, Jul 30, 2020 at 11:35:03AM +0200, Maxime Ripard wrote: > The A20 can use its second TCON as the secondary LVDS link in a dual-link > setup, with the TCON0 being the main link. Extend a bit the parsing code to > leverage the DRM dual-link code, register only the LVDS output on the > primary TCON, and add the needed bits to setup the TCON properly. > > Signed-off-by: Maxime Ripard > --- > drivers/gpu/drm/sun4i/sun4i_tcon.c | 36 +++++++++++++++++++++++++++++++- > drivers/gpu/drm/sun4i/sun4i_tcon.h | 4 +++- > 2 files changed, 40 insertions(+) > > diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c > index d03ad75f9900..ed2abf6eb18b 100644 > --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c > +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c > @@ -487,6 +487,9 @@ static void sun4i_tcon0_mode_set_lvds(struct sun4i_tcon *tcon, > else > reg |= SUN4I_TCON0_LVDS_IF_DATA_POL_NORMAL; > > + if (tcon->lvds_dual_link) > + reg |= SUN4I_TCON0_LVDS_IF_DUAL_LINK; > + > if (sun4i_tcon_get_pixel_depth(encoder) == 24) > reg |= SUN4I_TCON0_LVDS_IF_BITWIDTH_24BITS; > else > @@ -896,6 +899,16 @@ static int sun4i_tcon_register_panel(struct drm_device *drm, > return sun4i_rgb_init(drm, tcon); > > /* > + * Only the TCON0 will be relevant for the LVDS output, so if > + * our ID is something else, let's prevent our TCON from > + * registering its own LVDS output > + */ > + if (tcon->id) { > + dev_info(dev, "Secondary TCON, disabling panel output"); This may worry the user unnecessarily. I'd make it a debug message, or drop it completely, and like reword it a bit as pointed out by Chen-Yu. > + return 0; > + } > + > + /* > * This can only be made optional since we've had DT > * nodes without the LVDS reset properties. > * > @@ -941,6 +954,28 @@ static int sun4i_tcon_register_panel(struct drm_device *drm, > return -ENODEV; > } > > + /* > + * If we don't have a second TCON, we will never be able to do > + * dual-link LVDS, so we don't have much more to do. > + */ > + companion = of_parse_phandle(dev->of_node, "allwinner,lvds-companion", 0); Should there be a patch to add this property to the DT bindings ? > + if (!companion) > + return 0; > + > + /* > + * Let's do a sanity check on the dual-link setup to make sure > + * everything is properly described. > + */ > + ret = drm_of_lvds_get_dual_link_pixel_order(dev->of_node, 1, 0, > + companion, 1, 0); > + if (ret < 0) { > + dev_err(dev, "Invalid Dual-Link Configuration.\n"); > + return ret; > + } > + > + dev_info(dev, "Primary TCON, enabling LVDS Dual-Link"); > + tcon->lvds_dual_link = true; > + > return sun4i_lvds_init(drm, tcon); > } > > @@ -1500,6 +1535,7 @@ static const struct sun4i_tcon_quirks sun7i_a20_tcon0_quirks = { > }; > > static const struct sun4i_tcon_quirks sun7i_a20_quirks = { > + .supports_lvds = true, Should this be split to a separate patch, or at least mentioned in the commit message ? > .has_channel_0 = true, > .has_channel_1 = true, > .dclk_min_div = 4, > diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.h b/drivers/gpu/drm/sun4i/sun4i_tcon.h > index cfbf4e6c1679..51c4e09cdd13 100644 > --- a/drivers/gpu/drm/sun4i/sun4i_tcon.h > +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.h > @@ -98,6 +98,7 @@ > > #define SUN4I_TCON0_LVDS_IF_REG 0x84 > #define SUN4I_TCON0_LVDS_IF_EN BIT(31) > +#define SUN4I_TCON0_LVDS_IF_DUAL_LINK BIT(30) > #define SUN4I_TCON0_LVDS_IF_BITWIDTH_MASK BIT(26) > #define SUN4I_TCON0_LVDS_IF_BITWIDTH_18BITS (1 << 26) > #define SUN4I_TCON0_LVDS_IF_BITWIDTH_24BITS (0 << 26) > @@ -274,6 +275,9 @@ struct sun4i_tcon { > /* Associated crtc */ > struct sun4i_crtc *crtc; > > + /* Is the LVDS link a dual-channel link? */ > + bool lvds_dual_link; > + > int id; > > /* TCON list management */ -- Regards, Laurent Pinchart