Commit e08e934d authored by Jacopo Mondi's avatar Jacopo Mondi Committed by Laurent Pinchart
Browse files

drm: rcar-du: Add support for CMM 



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.

Reviewed-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: default avatarKieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: default avatarJacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
parent 6e2258b5

drivers/gpu/drm/rcar-du/Kconfig

+8 −0
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@@ -4,6 +4,7 @@ config DRM_RCAR_DU 
	depends on DRM && OF

	depends on ARM || ARM64

	depends on ARCH_RENESAS || COMPILE_TEST

	imply DRM_RCAR_CMM

	imply DRM_RCAR_LVDS

	select DRM_KMS_HELPER

	select DRM_KMS_CMA_HELPER
@@ -13,6 +14,13 @@ 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

	tristate "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

drivers/gpu/drm/rcar-du/Makefile

+1 −0
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@@ -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

drivers/gpu/drm/rcar-du/rcar_cmm.c

0 → 100644
+217 −0
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// SPDX-License-Identifier: GPL-2.0+

/*

 * rcar_cmm.c -- R-Car Display Unit Color Management Module

 *

 * Copyright (C) 2019 Jacopo Mondi <jacopo+renesas@jmondi.org>

 */



#include <linux/io.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/platform_device.h>

#include <linux/pm_runtime.h>



#include <drm/drm_color_mgmt.h>



#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 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

 * @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

			  | 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.

 *

 * As rcar_cmm_setup() accesses the CMM registers the unit should be powered

 * and its functional clock enabled. To guarantee this, before any call to

 * this function is made, the CMM unit has to be enabled by calling

 * rcar_cmm_enable() first.

 *

 * TODO: Add support for LUT double buffer operations to avoid updating the

 * LUT table entries while a frame is being displayed.

 */

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 no table is provided. */

	if (!config->lut.table) {

		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

 *

 * 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 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.

 */

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

 *

 * 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 unit

 * @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 <jacopo+renesas@jmondi.org>");

MODULE_DESCRIPTION("Renesas R-Car CMM Driver");

MODULE_LICENSE("GPL v2");

drivers/gpu/drm/rcar-du/rcar_cmm.h

0 → 100644
+58 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0+ */

/*

 * rcar_cmm.h -- R-Car Display Unit Color Management Module

 *

 * Copyright (C) 2019 Jacopo Mondi <jacopo+renesas@jmondi.org>

 */



#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.table:	1D-LUT table entries. Disable LUT operations when NULL

 */

struct rcar_cmm_config {

	struct {

		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 -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__ */

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