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: Laurent Pinchart laurent.pinchart@ideasonboard.com Reviewed-by: Kieran Bingham kieran.bingham+renesas@ideasonboard.com Signed-off-by: Jacopo Mondi jacopo+renesas@jmondi.org
--- v6 -> v6.1 - Expand rcar_cmm_setup() function documentation to detail its relationship with rcar_cmm_enable() and their call order precedence. ---
drivers/gpu/drm/rcar-du/Kconfig | 7 + drivers/gpu/drm/rcar-du/Makefile | 1 + drivers/gpu/drm/rcar-du/rcar_cmm.c | 217 +++++++++++++++++++++++++++++ drivers/gpu/drm/rcar-du/rcar_cmm.h | 58 ++++++++ 4 files changed, 283 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..952316eb202b --- /dev/null +++ b/drivers/gpu/drm/rcar-du/rcar_cmm.c @@ -0,0 +1,217 @@ +// 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"); 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..b5f7ec6db04a --- /dev/null +++ b/drivers/gpu/drm/rcar-du/rcar_cmm.h @@ -0,0 +1,58 @@ +/* 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__ */ -- 2.23.0