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=-8.3 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,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 720BDECE58F for ; Tue, 15 Oct 2019 17:25:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3B38A20872 for ; Tue, 15 Oct 2019 17:25:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="k/h4bIm4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388703AbfJORZb (ORCPT ); Tue, 15 Oct 2019 13:25:31 -0400 Received: from perceval.ideasonboard.com ([213.167.242.64]:57326 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727242AbfJORZb (ORCPT ); Tue, 15 Oct 2019 13:25:31 -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 14D20324; Tue, 15 Oct 2019 19:25:27 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1571160327; bh=BI8OaXXBknVbUuVSFQ+3+rQhs0xihyr00Mcv1/eLEFo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=k/h4bIm4YKHnXi2rWm65TEAhHnVipNyFnTfqhoPtFXuJavMZPZn1q6Duan8Hrfyih I/hoehoPbjSb2buKtIi8EI9P9JWz+FaaDK4EJitYOuEluD6Cs0mxGasmnZqh4mLrRR IzninsOII5qMrvPTS+wokvGcL0bGL5djT7HMcoIs= Date: Tue, 15 Oct 2019 20:25:24 +0300 From: Laurent Pinchart To: Jacopo Mondi Cc: kieran.bingham+renesas@ideasonboard.com, 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, ezequiel@collabora.com, seanpaul@chromium.org, linux-renesas-soc@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 3/8] drm: rcar-du: Add support for CMM Message-ID: <20191015172524.GM4875@pendragon.ideasonboard.com> References: <20191015104621.62514-1-jacopo+renesas@jmondi.org> <20191015104621.62514-4-jacopo+renesas@jmondi.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20191015104621.62514-4-jacopo+renesas@jmondi.org> 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 Jacopo, Thank you for the patch. On Tue, Oct 15, 2019 at 12:46:16PM +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 features will be > implemented on top of this initial 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 | 198 +++++++++++++++++++++++++++++ > drivers/gpu/drm/rcar-du/rcar_cmm.h | 60 +++++++++ > 4 files changed, 266 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..9675a8587dee > --- /dev/null > +++ b/drivers/gpu/drm/rcar-du/rcar_cmm.c > @@ -0,0 +1,198 @@ > +// 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; > + > + /* > + * @lut: 1D-LUT status s/status/state/ ? > + * @lut.enabled: 1D-LUT enabled flag > + */ > + struct { > + bool enabled; > + } 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_write() - Scale the DRM LUT table entries to hardware precision > + * and write to the CMM registers. Some of you brief descriptions end with a period, some don't. I don't have a preference, but could you please pick one option and use it consistently ? > + * @rcmm: Pointer to the CMM device > + * @drm_lut: Pointer to the DRM LUT table > + */ > +static void rcar_cmm_lut_write(struct rcar_cmm *rcmm, > + const struct drm_color_lut *drm_lut) > +{ > + unsigned int i; > + > + for (i = 0; i < CM2_LUT_SIZE; ++i) { > + u32 entry = drm_color_lut_extract(drm_lut[i].red, 8) << 16 As reported by Kieran, s/= /= / > + | drm_color_lut_extract(drm_lut[i].green, 8) << 8 > + | drm_color_lut_extract(drm_lut[i].blue, 8); > + > + rcar_cmm_write(rcmm, CM2_LUT_TBL(i), entry); > + } > +} > + > +/* > + * rcar_cmm_setup() - Configure the CMM unit. > + * @pdev: The platform device associated with the CMM instance > + * @config: The CMM unit configuration > + * > + * Configure the CMM unit with the given 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); > + > + /* Disable LUT 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. */ > + if (!rcmm->lut.enabled) { > + rcar_cmm_write(rcmm, CM2_LUT_CTRL, CM2_LUT_CTRL_LUT_EN); > + rcmm->lut.enabled = true; > + } > + > + rcar_cmm_lut_write(rcmm, config->lut.table); > + > + 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. It would be better to explain how the function should be used rather than what it does internally. * Enable the CMM unit. When the output of the corresponding DU channel is * routed to the CMM unit, the unit shall be enabled before the DU channel is * started, and remain enabled until the channel is stopped. The CMM unit shall * the be disabled with rcar_cmm_disable(). * * Calls to rcar_cmm_enable() and rcar_cmm_disable() are not reference-counted. * It is an error to attempt to enable an already enabled CMM unit, or to * attempt to disable a disabled unit. The relationship with rcar_cmm_setup() should also be documented. Looking at the code, I believe rcar_cmm_enable() has to be called first, otherwise the CMM MSTP will be disabled, and registers can't be accessed. I would document this as part of the rcar_cmm_setup() function. > + */ > +int rcar_cmm_enable(struct platform_device *pdev) > +{ > + int ret; > + > + ret = pm_runtime_get_sync(&pdev->dev); > + if (ret < 0) > + return ret; > + > + 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. Same here, but you can simply reference rcar_cmm_enable(). * Disable the CMM unit. See rcar_cmm_enable() for usage information. * * Disabling the CMM unit disable all the internal processing blocks. The CMM * state shall thus be restored with rcar_cmm_setup() when re-enabling the CMM * unit after the next rcar_cmm_enable() call. > + */ > +void rcar_cmm_disable(struct platform_device *pdev) > +{ > + struct rcar_cmm *rcmm = platform_get_drvdata(pdev); > + > + rcar_cmm_write(rcmm, CM2_LUT_CTRL, 0); > + rcmm->lut.enabled = false; > + > + pm_runtime_put(&pdev->dev); > +} > +EXPORT_SYMBOL_GPL(rcar_cmm_disable); > + > +/* > + * rcar_cmm_init() - Initialize the CMM > + * @pdev: The platform device associated with the CMM instance > + * > + * Return: 0 on success, -EPROBE_DEFER if the CMM is not available yet, > + * -ENODEV if the DRM_RCAR_CMM config option is disabled > + */ > +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..358ec03cf48a > --- /dev/null > +++ b/drivers/gpu/drm/rcar-du/rcar_cmm.h > @@ -0,0 +1,60 @@ > +/* 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 > + */ > +struct rcar_cmm_config { > + struct { > + bool enable; > + struct drm_color_lut *table; As enable == true implies table != NULL, and enable == false implies table == NULL, could we drop the enable field ? With those small issues addressed, Reviewed-by: Laurent Pinchart > + } 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 -ENODEV; > +} > + > +static inline int rcar_cmm_enable(struct platform_device *pdev) > +{ > + return 0; > +} > + > +static inline void rcar_cmm_disable(struct platform_device *pdev) > +{ > +} > + > +static inline 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