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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 E1DFDC83004 for ; Tue, 28 Apr 2020 10:19:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B4C74206D6 for ; Tue, 28 Apr 2020 10:19:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="kgKO0cBP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727831AbgD1KTN (ORCPT ); Tue, 28 Apr 2020 06:19:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51244 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1727813AbgD1KTI (ORCPT ); Tue, 28 Apr 2020 06:19:08 -0400 Received: from mail-wm1-x343.google.com (mail-wm1-x343.google.com [IPv6:2a00:1450:4864:20::343]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5A293C03C1AC for ; Tue, 28 Apr 2020 03:19:04 -0700 (PDT) Received: by mail-wm1-x343.google.com with SMTP id z6so2229629wml.2 for ; Tue, 28 Apr 2020 03:19:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=date:from:to:cc:subject:message-id:mail-followup-to:references :mime-version:content-disposition:in-reply-to; bh=kG3pAr197zg/lS7mr8VNmBDpYyQu9IqibYfSDpBEn7k=; b=kgKO0cBP5Bssi7//kT69CO7mZYdf7AyFI1rR8/f/GDrUOTsB4qJ+hKHVFiJ9XtAS/o qP+mV4FkHAYXgBQdP2KVdASCvVYZOtS4NY0qKQYpCQ4aOLNXho1KhTsnQToVN3oudcCY PExtKt2Fx6dhe7iJ0BX5OyWPtd3rl8z+CcTqw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id :mail-followup-to:references:mime-version:content-disposition :in-reply-to; bh=kG3pAr197zg/lS7mr8VNmBDpYyQu9IqibYfSDpBEn7k=; b=rukPLkzOEniRmcMDkFs7+WAtf6WFVX6IzUtMrow1MUQLa/1Xc+CiQVjX1sisDD/lgL 2nT0On76samBONUo8jyToC9zn/2P64/d9KXtf1UcKfFOWKnjOexy6IDu5p6WwG7ZNeod mjNYR63G8DDyTTfVYnHydyrU6wQNuj9CFgs8SzD+E1dkoApDCGaNX/Q3CsPLozgzWn2+ sTKoC1sXHWpfxlt4i/Y0wvF6DEqJiGOVz/wRDOR+vauzJkvFPfeM5flk5sXxUp9VRQUm 95slTr2aPBgLXksPmbW+QZDaItCVk7n9x3P4wDTtgjj67Nf+msY+WY4/2O52MgACpfQc kMBQ== X-Gm-Message-State: AGi0PuavxvnBgfmr0RAJ8ONCZRFl4Hh5N+85aw2mN3wla01xMqYb5334 dJReoSeuARsZxkTWsIbOWEz4Ow== X-Google-Smtp-Source: APiQypKo38IfQ2C40mSf8kIDZj3p6vDuj6I8VfusT2k9k8ZJbwXy1/pntxWf3JXgC9wEVd95IwAP8w== X-Received: by 2002:a1c:a90a:: with SMTP id s10mr3498028wme.99.1588069142896; Tue, 28 Apr 2020 03:19:02 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id w18sm24063758wrn.55.2020.04.28.03.19.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Apr 2020 03:19:02 -0700 (PDT) Date: Tue, 28 Apr 2020 12:19:00 +0200 From: Daniel Vetter To: Neil Armstrong Cc: Eugeniy Paltsev , dri-devel@lists.freedesktop.org, Alexey Brodkin , linux-snps-arc@lists.infradead.org, linux-kernel@vger.kernel.org, David Airlie , Maarten Lankhorst , Maxime Ripard , devicetree@vger.kernel.org, Rob Herring , Sam Ravnborg Subject: Re: [PATCH v3 1/2] DRM: ARC: add HDMI 2.0 TX encoder support Message-ID: <20200428101900.GG3456981@phenom.ffwll.local> Mail-Followup-To: Neil Armstrong , Eugeniy Paltsev , dri-devel@lists.freedesktop.org, Alexey Brodkin , linux-snps-arc@lists.infradead.org, linux-kernel@vger.kernel.org, David Airlie , Maarten Lankhorst , Maxime Ripard , devicetree@vger.kernel.org, Rob Herring , Sam Ravnborg References: <20200414232929.22788-1-Eugeniy.Paltsev@synopsys.com> <20200414232929.22788-2-Eugeniy.Paltsev@synopsys.com> <20200415173320.GG3456981@phenom.ffwll.local> <267d49d8-a73a-0317-cb50-0f63f0ced049@baylibre.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <267d49d8-a73a-0317-cb50-0f63f0ced049@baylibre.com> X-Operating-System: Linux phenom 5.3.0-3-amd64 Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Tue, Apr 21, 2020 at 05:55:38PM +0200, Neil Armstrong wrote: > On 15/04/2020 19:33, Daniel Vetter wrote: > > On Wed, Apr 15, 2020 at 02:29:28AM +0300, Eugeniy Paltsev wrote: > >> The Synopsys ARC SoCs (like HSDK4xD) include on-chip DesignWare HDMI > >> encoders. Support them with a platform driver to provide platform glue > >> data to the dw-hdmi driver. > >> > >> Acked-by: Sam Ravnborg > >> Signed-off-by: Eugeniy Paltsev > >> --- > >> MAINTAINERS | 6 ++ > >> drivers/gpu/drm/Makefile | 2 +- > >> drivers/gpu/drm/arc/Kconfig | 7 ++ > >> drivers/gpu/drm/arc/Makefile | 1 + > >> drivers/gpu/drm/arc/arc-dw-hdmi.c | 116 ++++++++++++++++++++++++++++++ > >> 5 files changed, 131 insertions(+), 1 deletion(-) > >> create mode 100644 drivers/gpu/drm/arc/arc-dw-hdmi.c > >> > >> diff --git a/MAINTAINERS b/MAINTAINERS > >> index a6fbdf354d34..2aaed1190370 100644 > >> --- a/MAINTAINERS > >> +++ b/MAINTAINERS > >> @@ -1258,6 +1258,12 @@ S: Supported > >> F: drivers/gpu/drm/arc/ > >> F: Documentation/devicetree/bindings/display/snps,arcpgu.txt > >> > >> +ARC DW HDMI DRIVER > >> +M: Eugeniy Paltsev > >> +S: Supported > >> +F: drivers/gpu/drm/arc/arc-dw-hdmi.c > >> +F: Documentation/devicetree/bindings/display/bridge/snps,arc-dw-hdmi.yaml > >> + > >> ARCNET NETWORK LAYER > >> M: Michael Grzeschik > >> L: netdev@vger.kernel.org > >> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile > >> index 6493088a0fdd..5b0bcf7f45cd 100644 > >> --- a/drivers/gpu/drm/Makefile > >> +++ b/drivers/gpu/drm/Makefile > >> @@ -109,7 +109,7 @@ obj-y += panel/ > >> obj-y += bridge/ > >> obj-$(CONFIG_DRM_FSL_DCU) += fsl-dcu/ > >> obj-$(CONFIG_DRM_ETNAVIV) += etnaviv/ > >> -obj-$(CONFIG_DRM_ARCPGU)+= arc/ > >> +obj-y += arc/ > >> obj-y += hisilicon/ > >> obj-$(CONFIG_DRM_ZTE) += zte/ > >> obj-$(CONFIG_DRM_MXSFB) += mxsfb/ > >> diff --git a/drivers/gpu/drm/arc/Kconfig b/drivers/gpu/drm/arc/Kconfig > >> index e8f3d63e0b91..baec9d2a4fba 100644 > >> --- a/drivers/gpu/drm/arc/Kconfig > >> +++ b/drivers/gpu/drm/arc/Kconfig > >> @@ -8,3 +8,10 @@ config DRM_ARCPGU > >> Choose this option if you have an ARC PGU controller. > >> > >> If M is selected the module will be called arcpgu. > >> + > >> +config DRM_ARC_DW_HDMI > >> + tristate "ARC DW HDMI" > >> + depends on DRM && OF > >> + select DRM_DW_HDMI > >> + help > >> + Synopsys DW HDMI driver for various ARC development boards > >> diff --git a/drivers/gpu/drm/arc/Makefile b/drivers/gpu/drm/arc/Makefile > >> index c7028b7427b3..7a156d8c2c3c 100644 > >> --- a/drivers/gpu/drm/arc/Makefile > >> +++ b/drivers/gpu/drm/arc/Makefile > >> @@ -1,3 +1,4 @@ > >> # SPDX-License-Identifier: GPL-2.0-only > >> arcpgu-y := arcpgu_crtc.o arcpgu_hdmi.o arcpgu_sim.o arcpgu_drv.o > >> obj-$(CONFIG_DRM_ARCPGU) += arcpgu.o > >> +obj-$(CONFIG_DRM_ARC_DW_HDMI) += arc-dw-hdmi.o > >> diff --git a/drivers/gpu/drm/arc/arc-dw-hdmi.c b/drivers/gpu/drm/arc/arc-dw-hdmi.c > >> new file mode 100644 > >> index 000000000000..46a6ee09b302 > >> --- /dev/null > >> +++ b/drivers/gpu/drm/arc/arc-dw-hdmi.c > >> @@ -0,0 +1,116 @@ > >> +// SPDX-License-Identifier: GPL-2.0+ > >> +// > >> +// Synopsys DW HDMI driver for various ARC development boards > >> +// > >> +// Copyright (C) 2020 Synopsys > >> +// Author: Eugeniy Paltsev > >> + > >> +#include > >> +#include > >> +#include > >> +#include > >> +#include > >> +#include > >> +#include > >> +#include > >> + > >> +static const struct dw_hdmi_mpll_config snps_hdmi_mpll_cfg[] = { > >> + { > >> + 27000000, { > >> + { 0x00B3, 0x0000 }, > >> + { 0x00B3, 0x0000 }, > >> + { 0x00B3, 0x0000 } > >> + }, > >> + }, { > >> + 74250000, { > >> + { 0x0072, 0x0001}, > >> + { 0x0072, 0x0001}, > >> + { 0x0072, 0x0001} > >> + }, > >> + }, { > >> + 148500000, { > >> + { 0x0051, 0x0002}, > >> + { 0x0051, 0x0002}, > >> + { 0x0051, 0x0002} > >> + }, > >> + }, { > >> + ~0UL, { > >> + { 0x00B3, 0x0000 }, > >> + { 0x00B3, 0x0000 }, > >> + { 0x00B3, 0x0000 }, > >> + }, > >> + } > >> +}; > >> + > >> +static const struct dw_hdmi_curr_ctrl snps_hdmi_cur_ctr[] = { > >> + /* pixelclk bpp8 bpp10 bpp12 */ > >> + { 27000000, { 0x0000, 0x0000, 0x0000 }, }, > >> + { 74250000, { 0x0008, 0x0008, 0x0008 }, }, > >> + { 148500000, { 0x001b, 0x001b, 0x001b }, }, > >> + { ~0UL, { 0x0000, 0x0000, 0x0000 }, } > >> +}; > >> + > >> + > >> +static const struct dw_hdmi_phy_config snps_hdmi_phy_config[] = { > >> + /* pixelclk symbol term vlev */ > >> + { 27000000, 0x8009, 0x0004, 0x0232}, > >> + { 74250000, 0x8009, 0x0004, 0x0232}, > >> + { 148500000, 0x8009, 0x0004, 0x0232}, > >> + { ~0UL, 0x8009, 0x0004, 0x0232} > >> +}; > >> + > >> +static struct dw_hdmi_plat_data snps_dw_hdmi_drv_data = { > >> + .mpll_cfg = snps_hdmi_mpll_cfg, > >> + .cur_ctr = snps_hdmi_cur_ctr, > >> + .phy_config = snps_hdmi_phy_config, > >> +}; > >> + > >> +static const struct of_device_id snps_dw_hdmi_dt_ids[] = { > >> + { .compatible = "snps,arc-dw-hdmi-hsdk", .data = &snps_dw_hdmi_drv_data }, > >> + { /* sentinel */ } > >> +}; > >> +MODULE_DEVICE_TABLE(of, snps_dw_hdmi_dt_ids); > >> + > >> +static int snps_dw_hdmi_probe(struct platform_device *pdev) > >> +{ > >> + const struct dw_hdmi_plat_data *plat_data; > >> + const struct of_device_id *match; > >> + struct dw_hdmi *hdmi; > >> + > >> + if (!pdev->dev.of_node) > >> + return -ENODEV; > >> + > >> + match = of_match_node(snps_dw_hdmi_dt_ids, pdev->dev.of_node); > >> + plat_data = match->data; > >> + > >> + hdmi = dw_hdmi_probe(pdev, plat_data); > > > > So this is kinda not how bridge drivers are supposed to be done nowadays, > > direct calling into the driver was the old way, and dw-hdmi still works > > like that. Modern way is roughly > > - bridge drivers bind automatically to any bridge they support > > - bridge drivers publish a bridge with drm_bridge_add() > > - the driver using the bridge fishes out with dt magic using > > of_drm_find_bridge() or another of the related of_ functions > > dw-hdmi is an IP, with some platform specific code and arrays to make it work > on very different systems, thus we can't use this scheme everywhere.... > > Some platforms (like r-car) uses the "right" model because the IP is integrated > as-is with the default PHY and as an independent IP on the system. > > It's definitely not the case on Rockchip/Amlogic/Allwinner systems, > and even worse on Amlogic system having a glue on top of the IP, and a > custom PHY instead of the Synopsys PHY. > > Thus it would be great this would be the case on a Synopsys SoC... but like > other platforms they have platform specific parameters. > > All this has been discussed and reviewed a few years ago, I would > personally prefer "fishing out a bridge using dt magic" instead having > 1k glue code around the IP. I'm not opposed to the per-instance glue code, that seems required. I'm kinda questioning where it is. Current design is that the glue code is in the drm_device driver side of things, with the drm_bridge somewhat awkward in-between. That doesn't seem very clean. I think more suitable for drm_bridge would be to push all the glue behind the drm_bridge (maybe into separate files in a drm/bridge/dw-hdmi/ directory), and the drm_device driver side simply grabs a drm_bridge and that's it. Then the drm_bridge abstraction lines up with the code organization again. Atm it's a bit a confusing state of things. Plan B would be to give up dw-hdmi being a drm_bridge, and rework dw-hdmi to be some kind of helper library to build a driver for a specific dw-hdmi instance. I think that would also be a clean design. But right now we kinda have a bit of both, so not really abstracted, but also not really a clean helper without midlayer either, and that doesn't look great. -Daniel > > Neil > > > > > I know a bit late, just spotted this because you brought your series here > > up in my arc cleanup series, but can you pls look into adjusting > > accordingly? > > > > I shouldn't take more than moving this binding here into the dw-hdmi > > driver, and switching arc itself over to the of_drm_find_bridge() call. > > That way we could slowly work to transform old bridge drivers like dw-hdmi > > to the new way, instead of adding more cases that will never get > > converted. > > > > Other upside is that arc stays a neat&tiny driver :-) > > > > Thanks, Daniel > > > >> + if (IS_ERR(hdmi)) > >> + return PTR_ERR(hdmi); > >> + > >> + platform_set_drvdata(pdev, hdmi); > >> + > >> + return 0; > >> +} > >> + > >> +static int snps_dw_hdmi_remove(struct platform_device *pdev) > >> +{ > >> + struct dw_hdmi *hdmi = platform_get_drvdata(pdev); > >> + > >> + dw_hdmi_remove(hdmi); > >> + > >> + return 0; > >> +} > >> + > >> +static struct platform_driver snps_dw_hdmi_platform_driver = { > >> + .probe = snps_dw_hdmi_probe, > >> + .remove = snps_dw_hdmi_remove, > >> + .driver = { > >> + .name = KBUILD_MODNAME, > >> + .of_match_table = snps_dw_hdmi_dt_ids, > >> + }, > >> +}; > >> +module_platform_driver(snps_dw_hdmi_platform_driver); > >> + > >> +MODULE_LICENSE("GPL v2"); > >> +MODULE_DESCRIPTION("ARC specific DW-HDMI driver extension"); > >> +MODULE_AUTHOR("Eugeniy Paltsev "); > >> -- > >> 2.21.1 > >> > > > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch