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=-8.4 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,USER_AGENT_SANE_1 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 4C15EC4CEC9 for ; Fri, 20 Sep 2019 22:43:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 062FE208C0 for ; Fri, 20 Sep 2019 22:43:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="f+Et5qfo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406254AbfITWnz (ORCPT ); Fri, 20 Sep 2019 18:43:55 -0400 Received: from perceval.ideasonboard.com ([213.167.242.64]:60752 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2393686AbfITWny (ORCPT ); Fri, 20 Sep 2019 18:43:54 -0400 Received: from pendragon.ideasonboard.com (81-175-216-236.bb.dnainternet.fi [81.175.216.236]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id BB2B22F9; Sat, 21 Sep 2019 00:43:51 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1569019431; bh=wRF+inf20HEiUbN9YBLR8jipxkbj24SDWRJymw3TjDE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=f+Et5qfogRANqs2APGlNOcaGPAnyy3JY+x4kGizhnFe98V1wbc32lTc1364A74pbz 69p/Oeph+DlIxTz+1PYRbLRgRpxfYHK9W9fkBOepx88DMiblgS9I+IdqLjHh2cX9ww avYpckF5eEKV/740lIVY1Ax2HRITAhCiXQi4A1k4= Date: Sat, 21 Sep 2019 01:43:42 +0300 From: Laurent Pinchart To: Kieran Bingham Cc: Jacopo Mondi , geert@linux-m68k.org, horms@verge.net.au, uli+renesas@fpond.eu, VenkataRajesh.Kalakodima@in.bosch.com, airlied@linux.ie, daniel@ffwll.ch, koji.matsuoka.xm@renesas.com, muroya@ksk.co.jp, Harsha.ManjulaMallikarjun@in.bosch.com, linux-renesas-soc@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 3/9] drm: rcar-du: Add support for CMM Message-ID: <20190920224342.GC12672@pendragon.ideasonboard.com> References: <20190906135436.10622-1-jacopo+renesas@jmondi.org> <20190906135436.10622-4-jacopo+renesas@jmondi.org> <20190918225534.GA11474@pendragon.ideasonboard.com> <48b1333a-74e4-34b8-f898-79a74a88a816@ideasonboard.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <48b1333a-74e4-34b8-f898-79a74a88a816@ideasonboard.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Kieran, On Thu, Sep 19, 2019 at 09:59:39AM +0100, Kieran Bingham wrote: > On 18/09/2019 23:55, Laurent Pinchart wrote: > > On Fri, Sep 06, 2019 at 03:54:30PM +0200, Jacopo Mondi wrote: > >> Add a driver for the R-Car Display Unit Color Correction Module. > >> > >> In most of Gen3 SoCs, each DU output channel is provided with a CMM unit > >> to perform image enhancement and color correction. > >> > >> Add support for CMM through a driver that supports configuration of > >> the 1-dimensional LUT table. More advanced CMM feature will be > >> implemented on top of this basic one. > >> > >> Signed-off-by: Jacopo Mondi > >> --- > >> drivers/gpu/drm/rcar-du/Kconfig | 7 + > >> drivers/gpu/drm/rcar-du/Makefile | 1 + > >> drivers/gpu/drm/rcar-du/rcar_cmm.c | 251 +++++++++++++++++++++++++++++ > >> drivers/gpu/drm/rcar-du/rcar_cmm.h | 61 +++++++ > >> 4 files changed, 320 insertions(+) > >> create mode 100644 drivers/gpu/drm/rcar-du/rcar_cmm.c > >> create mode 100644 drivers/gpu/drm/rcar-du/rcar_cmm.h > >> > >> diff --git a/drivers/gpu/drm/rcar-du/Kconfig b/drivers/gpu/drm/rcar-du/Kconfig > >> index 1529849e217e..539d232790d1 100644 > >> --- a/drivers/gpu/drm/rcar-du/Kconfig > >> +++ b/drivers/gpu/drm/rcar-du/Kconfig > >> @@ -13,6 +13,13 @@ config DRM_RCAR_DU > >> Choose this option if you have an R-Car chipset. > >> If M is selected the module will be called rcar-du-drm. > >> > >> +config DRM_RCAR_CMM > >> + bool "R-Car DU Color Management Module (CMM) Support" > >> + depends on DRM && OF > >> + depends on DRM_RCAR_DU > >> + help > >> + Enable support for R-Car Color Management Module (CMM). > >> + > >> config DRM_RCAR_DW_HDMI > >> tristate "R-Car DU Gen3 HDMI Encoder Support" > >> depends on DRM && OF > >> diff --git a/drivers/gpu/drm/rcar-du/Makefile b/drivers/gpu/drm/rcar-du/Makefile > >> index 6c2ed9c46467..4d1187ccc3e5 100644 > >> --- a/drivers/gpu/drm/rcar-du/Makefile > >> +++ b/drivers/gpu/drm/rcar-du/Makefile > >> @@ -15,6 +15,7 @@ rcar-du-drm-$(CONFIG_DRM_RCAR_LVDS) += rcar_du_of.o \ > >> rcar-du-drm-$(CONFIG_DRM_RCAR_VSP) += rcar_du_vsp.o > >> rcar-du-drm-$(CONFIG_DRM_RCAR_WRITEBACK) += rcar_du_writeback.o > >> > >> +obj-$(CONFIG_DRM_RCAR_CMM) += rcar_cmm.o > >> obj-$(CONFIG_DRM_RCAR_DU) += rcar-du-drm.o > >> obj-$(CONFIG_DRM_RCAR_DW_HDMI) += rcar_dw_hdmi.o > >> obj-$(CONFIG_DRM_RCAR_LVDS) += rcar_lvds.o > >> diff --git a/drivers/gpu/drm/rcar-du/rcar_cmm.c b/drivers/gpu/drm/rcar-du/rcar_cmm.c > >> new file mode 100644 > >> index 000000000000..3cacdc4474c7 > >> --- /dev/null > >> +++ b/drivers/gpu/drm/rcar-du/rcar_cmm.c > >> @@ -0,0 +1,251 @@ > >> +// SPDX-License-Identifier: GPL-2.0+ > >> +/* > >> + * rcar_cmm.c -- R-Car Display Unit Color Management Module > >> + * > >> + * Copyright (C) 2019 Jacopo Mondi > >> + */ > >> + > >> +#include > >> +#include > >> +#include > >> +#include > >> +#include > >> + > >> +#include > >> + > >> +#include "rcar_cmm.h" > >> + > >> +#define CM2_LUT_CTRL 0x0000 > >> +#define CM2_LUT_CTRL_LUT_EN BIT(0) > >> +#define CM2_LUT_TBL_BASE 0x0600 > >> +#define CM2_LUT_TBL(__i) (CM2_LUT_TBL_BASE + (__i) * 4) > >> + > >> +struct rcar_cmm { > >> + void __iomem *base; > >> + bool enabled; > >> + > >> + /* > >> + * @lut: 1D-LUT status > >> + * @lut.enabled: 1D-LUT enabled flag > >> + * @lut.table: Table of 1D-LUT entries scaled to hardware > >> + * precision (8-bits per color component) > >> + */ > >> + struct { > >> + bool enabled; > >> + u32 table[CM2_LUT_SIZE]; > >> + } lut; > >> +}; > >> + > >> +static inline int rcar_cmm_read(struct rcar_cmm *rcmm, u32 reg) > >> +{ > >> + return ioread32(rcmm->base + reg); > >> +} > >> + > >> +static inline void rcar_cmm_write(struct rcar_cmm *rcmm, u32 reg, u32 data) > >> +{ > >> + iowrite32(data, rcmm->base + reg); > >> +} > >> + > >> +/* > >> + * rcar_cmm_lut_extract() - Scale down to hardware precision the DRM LUT table > >> + * entries and store them. > > > > "Scale the DRM LUT table entries to hardware precision and store them." > > > >> + * @rcmm: Pointer to the CMM device > >> + * @drm_lut: Pointer to the DRM LUT table > >> + */ > >> +static void rcar_cmm_lut_extract(struct rcar_cmm *rcmm, > >> + const struct drm_color_lut *drm_lut) > >> +{ > >> + unsigned int i; > >> + > >> + for (i = 0; i < CM2_LUT_SIZE; ++i) { > >> + const struct drm_color_lut *lut = &drm_lut[i]; > >> + > >> + rcmm->lut.table[i] = drm_color_lut_extract(lut->red, 8) << 16 > >> + | drm_color_lut_extract(lut->green, 8) << 8 > >> + | drm_color_lut_extract(lut->blue, 8); > >> + } > >> +} > >> + > >> +/* > >> + * rcar_cmm_lut_write() - Write to hardware the LUT table entries from the > >> + * local table. > > > > "Write the LUT table entries from the local table to the hardware." > > > >> + * @rcmm: Pointer to the CMM device > >> + */ > >> +static void rcar_cmm_lut_write(struct rcar_cmm *rcmm) > >> +{ > >> + unsigned int i; > >> + > >> + for (i = 0; i < CM2_LUT_SIZE; ++i) > >> + rcar_cmm_write(rcmm, CM2_LUT_TBL(i), rcmm->lut.table[i]); > >> +} > >> + > >> +/* > >> + * rcar_cmm_setup() - Configure the CMM unit. > >> + * @pdev: The platform device associated with the CMM instance > >> + * @config: The CRTC-provided configuration. > >> + * > >> + * Configure the CMM unit with the CRTC-provided configuration. > >> + * Currently enabling, disabling and programming of the 1-D LUT unit is > >> + * supported. > >> + */ > >> +int rcar_cmm_setup(struct platform_device *pdev, > >> + const struct rcar_cmm_config *config) > >> +{ > >> + struct rcar_cmm *rcmm = platform_get_drvdata(pdev); > >> + > >> + /* > >> + * As rcar_cmm_setup() is called by atomic commit tail helper, it might > >> + * be called when the CMM is disabled. As we can't program the hardware > >> + * in that case, store the configuration internally and apply it when > >> + * the CMM will be enabled by the CRTC through rcar_cmm_enable(). > >> + */ > >> + if (!rcmm->enabled) { > >> + if (!config->lut.enable) > >> + return 0; > >> + > >> + rcar_cmm_lut_extract(rcmm, config->lut.table); > >> + rcmm->lut.enabled = true; > >> + > >> + return 0; > >> + } > >> + > >> + /* Stop LUT operations if requested. */ > >> + if (!config->lut.enable) { > >> + if (rcmm->lut.enabled) { > >> + rcar_cmm_write(rcmm, CM2_LUT_CTRL, 0); > >> + rcmm->lut.enabled = false; > >> + } > >> + > >> + return 0; > >> + } > >> + > >> + /* > >> + * Enable LUT and program the new gamma table values. > >> + * > >> + * FIXME: In order to have stable operations it is required to first > >> + * enable the 1D-LUT and then program its table entries. This seems to > >> + * contradict what the chip manual reports, and will have to be > >> + * reconsidered when implementing support for double buffering. > >> + */ > >> + if (!rcmm->lut.enabled) { > >> + rcar_cmm_write(rcmm, CM2_LUT_CTRL, CM2_LUT_CTRL_LUT_EN); > >> + rcmm->lut.enabled = true; > >> + } > >> + > >> + rcar_cmm_lut_extract(rcmm, config->lut.table); > >> + rcar_cmm_lut_write(rcmm); > >> + > >> + return 0; > >> +} > >> +EXPORT_SYMBOL_GPL(rcar_cmm_setup); > >> + > >> +/* > >> + * rcar_cmm_enable() - Enable the CMM unit. > >> + * @pdev: The platform device associated with the CMM instance > >> + * > >> + * Enable the CMM unit by enabling the parent clock and enabling the CMM > >> + * components, such as 1-D LUT, if requested. > >> + */ > >> +int rcar_cmm_enable(struct platform_device *pdev) > >> +{ > >> + struct rcar_cmm *rcmm = platform_get_drvdata(pdev); > >> + int ret; > >> + > >> + ret = pm_runtime_get_sync(&pdev->dev); > >> + if (ret < 0) > >> + return ret; > >> + > >> + /* Apply the LUT table values saved at rcar_cmm_setup() time. */ > >> + if (rcmm->lut.enabled) { > >> + rcar_cmm_write(rcmm, CM2_LUT_CTRL, CM2_LUT_CTRL_LUT_EN); > >> + rcar_cmm_lut_write(rcmm); > >> + } > >> + > >> + rcmm->enabled = true; > >> + > >> + return 0; > >> +} > >> +EXPORT_SYMBOL_GPL(rcar_cmm_enable); > >> + > >> +/* > >> + * rcar_cmm_disable() - Disable the CMM unit. > >> + * @pdev: The platform device associated with the CMM instance > >> + * > >> + * Disable the CMM unit by stopping the parent clock. > >> + */ > >> +void rcar_cmm_disable(struct platform_device *pdev) > >> +{ > >> + struct rcar_cmm *rcmm = platform_get_drvdata(pdev); > >> + > >> + rcar_cmm_write(rcmm, CM2_LUT_CTRL, 0); > >> + > >> + pm_runtime_put(&pdev->dev); > >> + > >> + rcmm->lut.enabled = false; > >> + rcmm->enabled = false; > >> +} > >> +EXPORT_SYMBOL_GPL(rcar_cmm_disable); > >> + > >> +/* > >> + * rcar_cmm_init() - Make sure the CMM has probed. > > > > I would document this as "Intialize the CMM" to match the function name. > > We may add more initialization in the future. > > > >> + * @pdev: The platform device associated with the CMM instance > >> + * > >> + * Return: 0 if the CMM has probed, -EPROBE_DEFER otherwise > > > > 0 on success, -EPROBE_DEFER is the CMM isn't availablet yet > > And possibly -ENODEV if the suggestion below in the header is worthy, to > return no device if the CMM is disabled at the CONFIG_ level. > > >> + */ > >> +int rcar_cmm_init(struct platform_device *pdev) > >> +{ > >> + struct rcar_cmm *rcmm = platform_get_drvdata(pdev); > >> + > >> + if (!rcmm) > >> + return -EPROBE_DEFER; > >> + > >> + return 0; > >> +} > >> +EXPORT_SYMBOL_GPL(rcar_cmm_init); > >> + > >> +static int rcar_cmm_probe(struct platform_device *pdev) > >> +{ > >> + struct rcar_cmm *rcmm; > >> + > >> + rcmm = devm_kzalloc(&pdev->dev, sizeof(*rcmm), GFP_KERNEL); > >> + if (!rcmm) > >> + return -ENOMEM; > >> + platform_set_drvdata(pdev, rcmm); > >> + > >> + rcmm->base = devm_platform_ioremap_resource(pdev, 0); > >> + if (IS_ERR(rcmm->base)) > >> + return PTR_ERR(rcmm->base); > >> + > >> + pm_runtime_enable(&pdev->dev); > >> + > >> + return 0; > >> +} > >> + > >> +static int rcar_cmm_remove(struct platform_device *pdev) > >> +{ > >> + pm_runtime_disable(&pdev->dev); > >> + > >> + return 0; > >> +} > >> + > >> +static const struct of_device_id rcar_cmm_of_table[] = { > >> + { .compatible = "renesas,rcar-gen3-cmm", }, > >> + { .compatible = "renesas,rcar-gen2-cmm", }, > >> + { }, > >> +}; > >> +MODULE_DEVICE_TABLE(of, rcar_cmm_of_table); > >> + > >> +static struct platform_driver rcar_cmm_platform_driver = { > >> + .probe = rcar_cmm_probe, > >> + .remove = rcar_cmm_remove, > >> + .driver = { > >> + .name = "rcar-cmm", > >> + .of_match_table = rcar_cmm_of_table, > >> + }, > >> +}; > >> + > >> +module_platform_driver(rcar_cmm_platform_driver); > >> + > >> +MODULE_AUTHOR("Jacopo Mondi "); > >> +MODULE_DESCRIPTION("Renesas R-Car CMM Driver"); > >> +MODULE_LICENSE("GPL v2"); > >> diff --git a/drivers/gpu/drm/rcar-du/rcar_cmm.h b/drivers/gpu/drm/rcar-du/rcar_cmm.h > >> new file mode 100644 > >> index 000000000000..15a2c874b6a6 > >> --- /dev/null > >> +++ b/drivers/gpu/drm/rcar-du/rcar_cmm.h > >> @@ -0,0 +1,61 @@ > >> +/* SPDX-License-Identifier: GPL-2.0+ */ > >> +/* > >> + * rcar_cmm.h -- R-Car Display Unit Color Management Module > >> + * > >> + * Copyright (C) 2019 Jacopo Mondi > >> + */ > >> + > >> +#ifndef __RCAR_CMM_H__ > >> +#define __RCAR_CMM_H__ > >> + > >> +#define CM2_LUT_SIZE 256 > >> + > >> +struct drm_color_lut; > >> +struct platform_device; > >> + > >> +/** > >> + * struct rcar_cmm_config - CMM configuration > >> + * > >> + * @lut: 1D-LUT configuration > >> + * @lut.enable: 1D-LUT enable flag > >> + * @lut.table: 1D-LUT table entries. Might be set to NULL when the CMM has to > >> + * be re-enabled but not re=programmed. > > > > s/re=programmed/re-programmed/ > > > > As discussed offline this can't really happen as far as I can tell. > > However, it will still be useful when we'll add CLU support, as then a > > CLU reprogramming without a LUT reprogramming could happen. > > > > I think we should make the documentation a bit clearer: > > > > "1D-LUT table entries. Only valid when lut.enable is true, shall be NULL > > otherwise. When non-NULL, the LUT table will be programmed with the new > > values. Otherwise the LUT table will retain its previously programmed > > values." > > > > This being said, the code in rcar_cmm_setup() will crash if table is > > NULL. I would either drop the option of table being NULL (and thus > > update the documentation here) if you don't need this yet in the DU > > driver, or fix rcar_cmm_setup(). You've posted enough versions of this > > series in my opinion, so please pick the easiest option, and we'll > > rework the code when adding CLU support anyway. > > > > With those small issues fixes, > > > > Reviewed-by: Laurent Pinchart > > > >> + */ > >> +struct rcar_cmm_config { > >> + struct { > >> + bool enable; > >> + struct drm_color_lut *table; > >> + } lut; > >> +}; > >> + > >> +#if IS_ENABLED(CONFIG_DRM_RCAR_CMM) > >> +int rcar_cmm_init(struct platform_device *pdev); > >> + > >> +int rcar_cmm_enable(struct platform_device *pdev); > >> +void rcar_cmm_disable(struct platform_device *pdev); > >> + > >> +int rcar_cmm_setup(struct platform_device *pdev, > >> + const struct rcar_cmm_config *config); > >> +#else > >> +static inline int rcar_cmm_init(struct platform_device *pdev) > >> +{ > >> + return 0; > > I feel like here, this should return -ENODEV if CMM is disabled, and > allow rcar_du_cmm_init() to succeed, but leave the rcdu->cmms[i] > unpopulated. ... I think that's a good idea, otherwise the DU driver will believe that CMM initialisation succeeded, and will configure the DU to route its outputs to the CMM. I don't think that would work nicely without a driver :-) Although, in practice, for the processing (non-statistics) path, the DU output clock may be all that is needed, so the CMM might be operational in its default configuration without the MSTP clock. Still, that's probably not a very safe path, so I'd rather see CMM being disabled on the DU side in that case. > But this could be updated later too if it's awkward ... Hopefully that would be easy to do :-) > >> +} > >> + > >> +static inline int rcar_cmm_enable(struct platform_device *pdev) > >> +{ > >> + return 0; > >> +} > >> + > >> +static inline void rcar_cmm_disable(struct platform_device *pdev) > >> +{ > >> +} > >> + > >> +static int rcar_cmm_setup(struct platform_device *pdev, > >> + const struct rcar_cmm_config *config) > >> +{ > >> + return 0; > >> +} > >> +#endif /* IS_ENABLED(CONFIG_DRM_RCAR_CMM) */ > >> + > >> +#endif /* __RCAR_CMM_H__ */ -- Regards, Laurent Pinchart