Add a driver for the R-Car Display Unit Color Correction Module.
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 could be implemented on top of this basic one.
Signed-off-by: Jacopo Mondi jacopo+renesas@jmondi.org --- drivers/gpu/drm/rcar-du/Kconfig | 7 + drivers/gpu/drm/rcar-du/Makefile | 1 + drivers/gpu/drm/rcar-du/rcar_cmm.c | 197 +++++++++++++++++++++++++++++ drivers/gpu/drm/rcar-du/rcar_cmm.h | 38 ++++++ 4 files changed, 243 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..5d9d917b91f4 --- /dev/null +++ b/drivers/gpu/drm/rcar-du/rcar_cmm.c @@ -0,0 +1,197 @@ +// 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/clk.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> + +#include <drm/drm_atomic.h> + +#include "rcar_cmm.h" + +#define CM2_LUT_CTRL 0x00 +#define CM2_LUT_CTRL_EN BIT(0) +#define CM2_LUT_TBLA 0x600 + +struct rcar_cmm { + struct clk *clk; + void __iomem *base; + bool enabled; + + /* LUT table scratch buffer. */ + struct { + bool restore; + unsigned int size; + uint32_t table[CMM_GAMMA_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); +} + +int rcar_cmm_setup(struct platform_device *pdev, struct rcar_cmm_config *config) +{ + struct rcar_cmm *rcmm = platform_get_drvdata(pdev); + unsigned int i; + + if (config->lut.size > CMM_GAMMA_LUT_SIZE) + return -EINVAL; + + /* + * As cmm_setup is called by atomic commit tail helper, it might be + * called before the enabling the CRTC (which calls cmm_enable()). + * + * Store the LUT table entries in the scratch buffer to be later + * programmed at enable time. + */ + if (!rcmm->enabled) { + if (!config->lut.enable) + return 0; + + for (i = 0; i < config->lut.size; ++i) { + struct drm_color_lut *lut = &config->lut.table[i]; + + rcmm->lut.table[i] = (lut->red & 0xff) << 16 | + (lut->green & 0xff) << 8 | + (lut->blue & 0xff); + } + + rcmm->lut.restore = true; + rcmm->lut.size = config->lut.size; + + return 0; + } + + if (rcar_cmm_read(rcmm, CM2_LUT_CTRL) & CM2_LUT_CTRL_EN && + !config->lut.enable) { + rcar_cmm_write(rcmm, CM2_LUT_CTRL, 0); + return 0; + } + + /* Enable LUT and program the new gamma table values. */ + rcar_cmm_write(rcmm, CM2_LUT_CTRL, CM2_LUT_CTRL_EN); + for (i = 0; i < config->lut.size; ++i) { + struct drm_color_lut *lut = &config->lut.table[i]; + u32 val = (lut->red & 0xff) << 16 | (lut->green & 0xff) << 8 | + (lut->blue & 0xff); + + rcar_cmm_write(rcmm, CM2_LUT_TBLA + i * 4, val); + } + + return 0; +} + +int rcar_cmm_enable(struct platform_device *pdev) +{ + struct rcar_cmm *rcmm = platform_get_drvdata(pdev); + unsigned int i; + int ret; + + if (rcmm->enabled) + return 0; + + ret = clk_prepare_enable(rcmm->clk); + if (ret) + return ret; + + /* Apply the LUT table values saved at cmm_setup time. */ + if (rcmm->lut.restore) { + rcar_cmm_write(rcmm, CM2_LUT_CTRL, CM2_LUT_CTRL_EN); + for (i = 0; i < rcmm->lut.size; ++i) + rcar_cmm_write(rcmm, CM2_LUT_TBLA + i * 4, + rcmm->lut.table[i]); + + rcmm->lut.restore = false; + rcmm->lut.size = 0; + } + + rcmm->enabled = true; + + return 0; +} + +void rcar_cmm_disable(struct platform_device *pdev) +{ + struct rcar_cmm *rcmm = platform_get_drvdata(pdev); + + rcar_cmm_write(rcmm, CM2_LUT_CTRL, 0); + + clk_disable_unprepare(rcmm->clk); + + rcmm->lut.restore = false; + rcmm->lut.size = 0; + rcmm->enabled = false; +} + +static int rcar_cmm_probe(struct platform_device *pdev) +{ + struct rcar_cmm *rcmm; + struct resource *res; + resource_size_t size; + + rcmm = devm_kzalloc(&pdev->dev, sizeof(*rcmm), GFP_KERNEL); + if (!rcmm) + return -ENOMEM; + + platform_set_drvdata(pdev, rcmm); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + size = resource_size(res); + if (!devm_request_mem_region(&pdev->dev, res->start, size, + dev_name(&pdev->dev))) { + dev_err(&pdev->dev, + "can't request region for resource %pR\n", res); + return -EBUSY; + } + + rcmm->base = devm_ioremap_nocache(&pdev->dev, res->start, size); + if (IS_ERR(rcmm->base)) + return PTR_ERR(rcmm->base); + + rcmm->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(rcmm->clk)) { + dev_err(&pdev->dev, "Failed to get CMM clock"); + return PTR_ERR(rcmm->clk); + } + + rcmm->lut.restore = false; + rcmm->lut.size = 0; + rcmm->enabled = false; + + return 0; +} + +static const struct of_device_id rcar_cmm_of_table[] = { + { .compatible = "renesas,cmm-gen3" }, + { .compatible = "renesas,cmm-gen2" }, + { }, +}; + +MODULE_DEVICE_TABLE(of, rcar_cmm_of_table); + +static struct platform_driver rcar_cmm_platform_driver = { + .probe = rcar_cmm_probe, + .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..da61a145dc5c --- /dev/null +++ b/drivers/gpu/drm/rcar-du/rcar_cmm.h @@ -0,0 +1,38 @@ +/* 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__ + +#include <linux/platform_device.h> + +#define CMM_GAMMA_LUT_SIZE 256 + +struct drm_color_lut; + +/** + * struct rcar_cmm_config - CMM configuration + * + * @lut: 1D-LUT configuration + * @lut.enable: 1D-LUT enable flag + * @lut.table: 1D-LUT table entries. + * @lut.size 1D-LUT number of entries. Max is 256 + */ +struct rcar_cmm_config { + struct { + bool enable; + struct drm_color_lut *table; + unsigned int size; + } lut; +}; + +int rcar_cmm_enable(struct platform_device *); +void rcar_cmm_disable(struct platform_device *); + +int rcar_cmm_setup(struct platform_device *, struct rcar_cmm_config *); + +#endif /* __RCAR_CMM_H__ */