Re: [PATCH v8 17/23] drm/mediatek: Support MT8188 Padding in display driver

[CK Hu (胡俊光)]

Hi, Hsiao-chien:

On Mon, 2023-10-16 at 18:40 +0800, Hsiao Chien Sung wrote:
> Padding is a new display module on MT8188, it provides ability
> to add pixels to width and height of a layer with specified colors.
> 
> Due to hardware design, Mixer in VDOSYS1 requires width of a layer
> to be 2-pixel-align, or 4-pixel-align when ETHDR is enabled,
> we need Padding to deal with odd width.

Reviewed-by: CK Hu <ck.hu@xxxxxxxxxxxx>

> 
> Signed-off-by: Hsiao Chien Sung <shawn.sung@xxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/mediatek/Makefile       |   3 +-
>  drivers/gpu/drm/mediatek/mtk_disp_drv.h |   4 +
>  drivers/gpu/drm/mediatek/mtk_drm_drv.c  |   1 +
>  drivers/gpu/drm/mediatek/mtk_drm_drv.h  |   2 +-
>  drivers/gpu/drm/mediatek/mtk_padding.c  | 160
> ++++++++++++++++++++++++
>  5 files changed, 168 insertions(+), 2 deletions(-)
>  create mode 100644 drivers/gpu/drm/mediatek/mtk_padding.c
> 
> diff --git a/drivers/gpu/drm/mediatek/Makefile
> b/drivers/gpu/drm/mediatek/Makefile
> index d4d193f60271..5e4436403b8d 100644
> --- a/drivers/gpu/drm/mediatek/Makefile
> +++ b/drivers/gpu/drm/mediatek/Makefile
> @@ -16,7 +16,8 @@ mediatek-drm-y := mtk_disp_aal.o \
>  		  mtk_dsi.o \
>  		  mtk_dpi.o \
>  		  mtk_ethdr.o \
> -		  mtk_mdp_rdma.o
> +		  mtk_mdp_rdma.o \
> +		  mtk_padding.o
>  
>  obj-$(CONFIG_DRM_MEDIATEK) += mediatek-drm.o
>  
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_drv.h
> b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
> index bf06ccb65652..e2b602037ac3 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_drv.h
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_drv.h
> @@ -159,4 +159,8 @@ void mtk_mdp_rdma_config(struct device *dev,
> struct mtk_mdp_rdma_cfg *cfg,
>  const u32 *mtk_mdp_rdma_get_formats(struct device *dev);
>  size_t mtk_mdp_rdma_get_num_formats(struct device *dev);
>  
> +int mtk_padding_clk_enable(struct device *dev);
> +void mtk_padding_clk_disable(struct device *dev);
> +void mtk_padding_start(struct device *dev);
> +void mtk_padding_stop(struct device *dev);
>  #endif
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> index cdce165c092e..62e6e9785443 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> @@ -1025,6 +1025,7 @@ static struct platform_driver * const
> mtk_drm_drivers[] = {
>  	&mtk_dsi_driver,
>  	&mtk_ethdr_driver,
>  	&mtk_mdp_rdma_driver,
> +	&mtk_padding_driver,
>  };
>  
>  static int __init mtk_drm_init(void)
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> index 8dca68ea1b94..d2efd715699f 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> @@ -72,5 +72,5 @@ extern struct platform_driver mtk_dpi_driver;
>  extern struct platform_driver mtk_dsi_driver;
>  extern struct platform_driver mtk_ethdr_driver;
>  extern struct platform_driver mtk_mdp_rdma_driver;
> -
> +extern struct platform_driver mtk_padding_driver;
>  #endif /* MTK_DRM_DRV_H */
> diff --git a/drivers/gpu/drm/mediatek/mtk_padding.c
> b/drivers/gpu/drm/mediatek/mtk_padding.c
> new file mode 100644
> index 000000000000..fa2e7fc9c7bd
> --- /dev/null
> +++ b/drivers/gpu/drm/mediatek/mtk_padding.c
> @@ -0,0 +1,160 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2023 MediaTek Inc.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/component.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/soc/mediatek/mtk-cmdq.h>
> +
> +#include "mtk_disp_drv.h"
> +#include "mtk_drm_crtc.h"
> +#include "mtk_drm_ddp_comp.h"
> +
> +#define PADDING_CONTROL_REG	0x00
> +#define PADDING_BYPASS			BIT(0)
> +#define PADDING_ENABLE			BIT(1)
> +#define PADDING_PIC_SIZE_REG	0x04
> +#define PADDING_H_REG		0x08 /* horizontal */
> +#define PADDING_V_REG		0x0c /* vertical */
> +#define PADDING_COLOR_REG	0x10
> +
> +/**
> + * struct mtk_padding - basic information of Padding
> + * @clk: Clock of the module
> + * @reg: Virtual address of the Padding for CPU to access
> + * @cmdq_reg: CMDQ setting of the Padding
> + *
> + * Every Padding should have different clock source, register base,
> and
> + * CMDQ settings, we stored these differences all together.
> + */
> +struct mtk_padding {
> +	struct clk		*clk;
> +	void __iomem		*reg;
> +	struct cmdq_client_reg	cmdq_reg;
> +};
> +
> +int mtk_padding_clk_enable(struct device *dev)
> +{
> +	struct mtk_padding *padding = dev_get_drvdata(dev);
> +
> +	return clk_prepare_enable(padding->clk);
> +}
> +
> +void mtk_padding_clk_disable(struct device *dev)
> +{
> +	struct mtk_padding *padding = dev_get_drvdata(dev);
> +
> +	clk_disable_unprepare(padding->clk);
> +}
> +
> +void mtk_padding_start(struct device *dev)
> +{
> +	struct mtk_padding *padding = dev_get_drvdata(dev);
> +
> +	writel(PADDING_ENABLE | PADDING_BYPASS,
> +	       padding->reg + PADDING_CONTROL_REG);
> +
> +	/*
> +	 * notice that even the padding is in bypass mode,
> +	 * all the settings must be cleared to 0 or
> +	 * undefined behaviors could happen
> +	 */
> +	writel(0, padding->reg + PADDING_PIC_SIZE_REG);
> +	writel(0, padding->reg + PADDING_H_REG);
> +	writel(0, padding->reg + PADDING_V_REG);
> +	writel(0, padding->reg + PADDING_COLOR_REG);
> +}
> +
> +void mtk_padding_stop(struct device *dev)
> +{
> +	struct mtk_padding *padding = dev_get_drvdata(dev);
> +
> +	writel(0, padding->reg + PADDING_CONTROL_REG);
> +}
> +
> +static int mtk_padding_bind(struct device *dev, struct device
> *master, void *data)
> +{
> +	return 0;
> +}
> +
> +static void mtk_padding_unbind(struct device *dev, struct device
> *master, void *data)
> +{
> +}
> +
> +static const struct component_ops mtk_padding_component_ops = {
> +	.bind	= mtk_padding_bind,
> +	.unbind = mtk_padding_unbind,
> +};
> +
> +static int mtk_padding_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct mtk_padding *priv;
> +	struct resource *res;
> +	int ret;
> +
> +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	priv->clk = devm_clk_get(dev, NULL);
> +	if (IS_ERR(priv->clk)) {
> +		dev_err(dev, "failed to get clk\n");
> +		return PTR_ERR(priv->clk);
> +	}
> +
> +	priv->reg = devm_platform_get_and_ioremap_resource(pdev, 0,
> &res);
> +	if (IS_ERR(priv->reg)) {
> +		dev_err(dev, "failed to do ioremap\n");
> +		return PTR_ERR(priv->reg);
> +	}
> +
> +#if IS_REACHABLE(CONFIG_MTK_CMDQ)
> +	ret = cmdq_dev_get_client_reg(dev, &priv->cmdq_reg, 0);
> +	if (ret) {
> +		dev_err(dev, "failed to get gce client reg\n");
> +		return ret;
> +	}
> +#endif
> +
> +	platform_set_drvdata(pdev, priv);
> +
> +	ret = devm_pm_runtime_enable(dev);
> +	if (ret)
> +		return ret;
> +
> +	ret = component_add(dev, &mtk_padding_component_ops);
> +	if (ret) {
> +		pm_runtime_disable(dev);
> +		return dev_err_probe(dev, ret, "failed to add
> component\n");
> +	}
> +
> +	return 0;
> +}
> +
> +static int mtk_padding_remove(struct platform_device *pdev)
> +{
> +	component_del(&pdev->dev, &mtk_padding_component_ops);
> +	return 0;
> +}
> +
> +static const struct of_device_id mtk_padding_driver_dt_match[] = {
> +	{ .compatible = "mediatek,mt8188-padding" },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, mtk_padding_driver_dt_match);
> +
> +struct platform_driver mtk_padding_driver = {
> +	.probe		= mtk_padding_probe,
> +	.remove		= mtk_padding_remove,
> +	.driver		= {
> +		.name	= "mediatek-padding",
> +		.owner	= THIS_MODULE,
> +		.of_match_table = mtk_padding_driver_dt_match,
> +	},
> +};