[PATCH 2/4] drm: rcar-du: cmm: Provide 3D-CLU support

[Kieran Bingham]

Hi Laurent,

On 21/12/2020 01:57, Laurent Pinchart wrote:
> From: Kieran Bingham <kieran.bingham+renesas at ideasonboard.com>
> 
> The CMM module provides a three-dimensional cubic look up table that
> converts three-color-component data into desired three color components
> by use of a lookup table.
> 
> While the 1D-LUT can only control each of three color components
> separately, the 3D-CLU can be used for specific color adjustment.
> 
> Signed-off-by: Kieran Bingham <kieran.bingham+renesas at ideasonboard.com>
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas at ideasonboard.com>

For the updates since I wrote the patch:

Reviewed-by: Kieran Bingham <kieran.bingham+renesas at ideasonboard.com>

> ---
>  drivers/gpu/drm/rcar-du/rcar_cmm.c | 52 ++++++++++++++++++++++++++++--
>  drivers/gpu/drm/rcar-du/rcar_cmm.h | 11 ++++---
>  2 files changed, 57 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/rcar-du/rcar_cmm.c b/drivers/gpu/drm/rcar-du/rcar_cmm.c
> index ccc8c8b03bac..9a20728a3534 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_cmm.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_cmm.c
> @@ -17,9 +17,18 @@
>  
>  #define CM2_LUT_CTRL		0x0000
>  #define CM2_LUT_CTRL_LUT_EN	BIT(0)
> +
> +#define CM2_CLU_CTRL		0x0100
> +#define CM2_CLU_CTRL_CLU_EN	BIT(1)
> +#define CM2_CLU_CTRL_MVS	BIT(24)
> +#define CM2_CLU_CTRL_AAI	BIT(28)
> +
>  #define CM2_LUT_TBL_BASE	0x0600
>  #define CM2_LUT_TBL(__i)	(CM2_LUT_TBL_BASE + (__i) * 4)
>  
> +#define CM2_CLU_ADDR		0x0a00
> +#define CM2_CLU_DATA		0x0a04
> +
>  struct rcar_cmm {
>  	void __iomem *base;
>  
> @@ -30,6 +39,10 @@ struct rcar_cmm {
>  	struct {
>  		bool enabled;
>  	} lut;
> +
> +	struct {
> +		bool enabled;
> +	} clu;
>  };
>  
>  static inline int rcar_cmm_read(struct rcar_cmm *rcmm, u32 reg)
> @@ -72,13 +85,44 @@ static void rcar_cmm_lut_configure(struct rcar_cmm *rcmm,
>  	}
>  }
>  
> +static void rcar_cmm_clu_configure(struct rcar_cmm *rcmm,
> +				   const struct drm_color_lut *table)
> +{
> +	static const u32 cfg = CM2_CLU_CTRL_AAI
> +			     | CM2_CLU_CTRL_MVS
> +			     | CM2_CLU_CTRL_CLU_EN;
> +	bool enable = !!table;

Good, not sure why I was calculating this outside of the call.


> +
> +	if (rcmm->clu.enabled != enable) {
> +		rcar_cmm_write(rcmm, CM2_CLU_CTRL, enable ? cfg : 0);
> +		rcmm->clu.enabled = enable;
> +	}
> +
> +	if (table) {
> +		unsigned int i;
> +
> +		/* Utilise CM2_CLU_CTRL_AAI (auto-increment). */
> +		rcar_cmm_write(rcmm, CM2_CLU_ADDR, 0);
> +
> +		for (i = 0; i < CM2_CLU_SIZE; ++i) {
> +			const struct drm_color_lut *lut = &table[i];
> +
> +			u32 entry = 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_write(rcmm, CM2_CLU_DATA, 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.
> + * Configure the CMM unit with the given configuration, handling both the
> + * 1-D LUT and the 3-D CLU.
>   *
>   * 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
> @@ -96,6 +140,9 @@ int rcar_cmm_setup(struct platform_device *pdev,
>  	if (config->lut.update)
>  		rcar_cmm_lut_configure(rcmm, config->lut.table);
>  
> +	if (config->clu.update)
> +		rcar_cmm_clu_configure(rcmm, config->clu.table);
> +
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(rcar_cmm_setup);
> @@ -140,6 +187,7 @@ void rcar_cmm_disable(struct platform_device *pdev)
>  	struct rcar_cmm *rcmm = platform_get_drvdata(pdev);
>  
>  	rcar_cmm_lut_configure(rcmm, NULL);
> +	rcar_cmm_clu_configure(rcmm, NULL);
>  
>  	pm_runtime_put(&pdev->dev);
>  }
> diff --git a/drivers/gpu/drm/rcar-du/rcar_cmm.h b/drivers/gpu/drm/rcar-du/rcar_cmm.h
> index f4b16535ec16..35f901158cec 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_cmm.h
> +++ b/drivers/gpu/drm/rcar-du/rcar_cmm.h
> @@ -9,14 +9,15 @@
>  #define __RCAR_CMM_H__
>  
>  #define CM2_LUT_SIZE		256
> +#define CM2_CLU_SIZE		(17 * 17 * 17)
>  
>  struct drm_color_lut;
>  struct platform_device;
>  
>  /**
> - * struct rcar_cmm_table_config - CMM LUT configuration
> - * @update: When true, update the LUT configuration.
> - * @table: Table data. The LUT is enabled if non-NULL, and disabled
> + * struct rcar_cmm_table_config - CMM LUT and CLU configuration
> + * @update: When true, update the LUT or CLU configuration.
> + * @table: Table data. The LUT or CLU is enabled if non-NULL, and disabled
>   *	otherwise. The value is ignored if @update is false.
>   */
>  struct rcar_cmm_table_config {
> @@ -26,10 +27,12 @@ struct rcar_cmm_table_config {
>  
>  /**
>   * struct rcar_cmm_config - CMM configuration
> - * @lut: 1D-LUT configuration
> + * @lut: 1D LUT configuration
> + * @clu: 3D (cubic) LUT configuration
>   */
>  struct rcar_cmm_config {
>  	struct rcar_cmm_table_config lut;
> +	struct rcar_cmm_table_config clu;
>  };
>  
>  #if IS_ENABLED(CONFIG_DRM_RCAR_CMM)
> 

-- 
Regards
--
Kieran