Hi Kieran, thanks for review
On Tue, Oct 15, 2019 at 12:53:55PM +0100, Kieran Bingham wrote:
> Hi Jacopo,
>
> On 15/10/2019 11:46, 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.
> >
>
> This is looking good to me.
>
> I have patches which start to add CLU on top of this, which refactor
> things slightly - but I don't think that refactoring needs to be in this
> series, and this version is independent and looks good ... thus:
>
> Reviewed-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
>
>
> > Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
> > ---
> > 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
>
>
> DRM_RCAR_DU already depends on both DRM && OF, so I wonder if those are
> needed to be specified explicitly.
>
> Doesn't hurt of course, but I see DRM_RCAR_DW_HDMI does the same, and so
> does DRM_RCAR_LVDS, so I don't think you need to remove it.
>
I did the same as it is done for HDMI and LVDS here. The extra
dependencies could be dropped yes, I chose to be consistent.
> > + 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 <jacopo+renesas@xxxxxxxxxx>
> > + */
> > +
> > +#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 status
> > + * @lut.enabled: 1D-LUT enabled flag
> > + */
> > + struct {
> > + bool enabled;
> > + } lut;
>
> This used to be a more complex structure in an earlier version storing a
> cached version of the table. Now that the cached entry is removed, does
> this need to be such a complex structure rather than just say, a bool
> lut_enabled?
>
> (We will soon add an equivalent clu_enabled too, but I don't know what
> other per-table options we'll need.)
>
> In fact, we'll potentially have other options specific to the HGO, and
> CSC at some point in the future - so grouping by entity is indeed a good
> thing IMO.
You are right, I pondered a bit it this was worth it, but I assume the
other CMM functions would have required some more complex fields so I
chose to keep it separate. I have no problem to make this a
lut_enabled, but I fear as soon as we support say, double buffering
for the lut, having a dedicated struct would be nice.
Is it ok if I keep this the way it is?
>
> > +};
> > +
> > +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.
> > + */
> > +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.
> > + */
> > +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.
> > + */
> > +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 <jacopo+renesas@xxxxxxxxxx>");
> > +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 <jacopo+renesas@xxxxxxxxxx>
> > + */
> > +
> > +#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;
> > + } 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;
>
> Excellent :-D
> > +}
> > +
> > +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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