Hi Laurent, On Thu, Sep 19, 2019 at 01:55:35AM +0300, Laurent Pinchart wrote: > Hi Jacopo, > > Thank you for the patch. > > 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 > Just to note I've take Kieran's suggestion in to return -ENODEV when the CMM config option is not set. > > + */ > > +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. How are we going to program CLU ? Using which DRM property ? I had a look at 'ctm', but it does not seems to apply, as it only provides 9 64bits entries (why 9??) https://elixir.bootlin.com/linux/latest/source/include/uapi/drm/drm_mode.h#L623 The CLU is programmed with pairs of 32bits entries, assembled using 8 bit data/addresses for each color components. Considering the LUT entries have 16 bits per color components, we could re-use those, but seems a bit of an abuse to me. Is there somethig more trivial I am missing ? Anyway, for now I think you are right, and if the 'crtc->state->gamma_lut' field is set, then the table (provided it's of the right size) cannot be NULL. Disabling the CMM with: req.add(crtc, { { "GAMMA_LUT", 0 }, }); results in 'crtc->state->gamma_lut' being not set, and this is already handled by setting to false the rcar_cmm_config.lut.enable flag in rcar_du_atomic_commit_update_cmm() so I would rather drop the table == NULL case from documentation and re-think about it once we handle CLU. > > 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. Unfortunately I would love to take your tag in and being done with this, but considering Sean's advices on Ezequiel's series, I think I'll now need to move CMM handling to crtc's begin/enable as well, so another review round will likely be required. > > 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; > > +} > > + > > +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