Date:   Thu, 20 May 2021 12:56:34 +0300
From:   Laurent Pinchart <laurent.pinchart@...asonboard.com>
To:     quanyang.wang@...driver.com
Cc:     Paul Cercueil <paul@...pouillou.net>,
        Hyun Kwon <hyun.kwon@...inx.com>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        Michal Simek <michal.simek@...inx.com>,
        dri-devel@...ts.freedesktop.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [V2][PATCH 2/2] drm: xlnx: consolidate the functions which
 programming AUDIO_VIDEO_SELECT register

Hi Quanyang,

Thank you for the patch.

On Tue, May 18, 2021 at 05:50:19PM +0800, quanyang.wang@...driver.com wrote:
> From: Quanyang Wang <quanyang.wang@...driver.com>
> 
> For now, the functions zynqmp_disp_avbuf_enable/disable_audio and
> zynqmp_disp_avbuf_enable/disable_video are all programming the register
> AV_BUF_OUTPUT_AUDIO_VIDEO_SELECT to select the output for audio or video.
> And in the future, many drm properties (like video_tpg, audio_tpg,
> audio_pl, etc) also need to access it. So let's introduce some variables
> of enum type and consolidate the code to unify handling this.
> 
> Signed-off-by: Quanyang Wang <quanyang.wang@...driver.com>
> ---
>  drivers/gpu/drm/xlnx/zynqmp_disp.c      | 168 ++++++++++++++----------
>  drivers/gpu/drm/xlnx/zynqmp_disp_regs.h |  23 +---
>  2 files changed, 106 insertions(+), 85 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xlnx/zynqmp_disp.c b/drivers/gpu/drm/xlnx/zynqmp_disp.c
> index eefb278e24c6..3672d2f5665b 100644
> --- a/drivers/gpu/drm/xlnx/zynqmp_disp.c
> +++ b/drivers/gpu/drm/xlnx/zynqmp_disp.c
> @@ -102,12 +102,39 @@ enum zynqmp_disp_layer_id {
>  
>  /**
>   * enum zynqmp_disp_layer_mode - Layer mode
> - * @ZYNQMP_DISP_LAYER_NONLIVE: non-live (memory) mode
> + * @ZYNQMP_DISP_LAYER_MEM: memory mode
>   * @ZYNQMP_DISP_LAYER_LIVE: live (stream) mode
> + * @ZYNQMP_DISP_LAYER_TPG: tpg mode (only for video layer)
> + * @ZYNQMP_DISP_LAYER_DISABLE: disable mode

"Disable" isn't really a mode :-S

>   */
>  enum zynqmp_disp_layer_mode {
> -	ZYNQMP_DISP_LAYER_NONLIVE,
> -	ZYNQMP_DISP_LAYER_LIVE
> +	ZYNQMP_DISP_LAYER_MEM,
> +	ZYNQMP_DISP_LAYER_LIVE,
> +	ZYNQMP_DISP_LAYER_TPG,
> +	ZYNQMP_DISP_LAYER_DISABLE
> +};
> +
> +enum avbuf_vid_mode {
> +	VID_MODE_LIVE,
> +	VID_MODE_MEM,
> +	VID_MODE_TPG,
> +	VID_MODE_NONE
> +};

I don't like this much. The enum here doesn't clearly show that the
values correspond to hardware register values. I'd rather address this
in drivers/gpu/drm/xlnx/zynqmp_disp_regs.h, see below for a proposal.

> +
> +enum avbuf_gfx_mode {
> +	GFX_MODE_DISABLE,
> +	GFX_MODE_MEM,
> +	GFX_MODE_LIVE,
> +	GFX_MODE_NONE
> +};
> +
> +enum avbuf_aud_mode {
> +	AUD1_MODE_LIVE,
> +	AUD1_MODE_MEM,
> +	AUD1_MODE_TPG,
> +	AUD1_MODE_DISABLE,
> +	AUD2_MODE_DISABLE,
> +	AUD2_MODE_ENABLE

Combining AUD1 and AUD2 in the same enum, with the
" - AUD2_MODE_DISABLE" below, is really a hack. Let's keep
hardware-related valeus in drivers/gpu/drm/xlnx/zynqmp_disp_regs.h.

Overall I'm not really fond of this rework I'm afraid, I think the
result is way less readable. Given that this isn't required yet as
support for the TPG or the PL input isn't part of this series, unless it
can be rewritten in a better way already, I'd prefer dropping this patch
for now and including it in a series that enables TPG or PL input.

I also think it could be beneficial to split the patch in two, it seems
to do a bit too much.

>  };
>  
>  /**
> @@ -542,92 +569,102 @@ static void zynqmp_disp_avbuf_disable_channels(struct zynqmp_disp_avbuf *avbuf)
>  }
>  
>  /**
> - * zynqmp_disp_avbuf_enable_audio - Enable audio
> + * zynqmp_disp_avbuf_output_select - Select the buffer manager outputs
>   * @avbuf: Audio/video buffer manager
> + * @layer: The layer
> + * @mode: The mode for this layer
>   *
> - * Enable all audio buffers with a non-live (memory) source.
> + * Select the buffer manager outputs for @layer.
>   */
> -static void zynqmp_disp_avbuf_enable_audio(struct zynqmp_disp_avbuf *avbuf)
> +static void zynqmp_disp_avbuf_output_select(struct zynqmp_disp_avbuf *avbuf,
> +					   struct zynqmp_disp_layer *layer,
> +					   u32 mode)
>  {
> -	u32 val;
> +	u32 reg;
>  
> -	val = zynqmp_disp_avbuf_read(avbuf, ZYNQMP_DISP_AV_BUF_OUTPUT);
> -	val &= ~ZYNQMP_DISP_AV_BUF_OUTPUT_AUD1_MASK;
> -	val |= ZYNQMP_DISP_AV_BUF_OUTPUT_AUD1_MEM;
> -	val |= ZYNQMP_DISP_AV_BUF_OUTPUT_AUD2_EN;
> -	zynqmp_disp_avbuf_write(avbuf, ZYNQMP_DISP_AV_BUF_OUTPUT, val);
> +	reg = zynqmp_disp_avbuf_read(avbuf, ZYNQMP_DISP_AV_BUF_OUTPUT);
> +
> +	/* Select audio mode when the layer is NULL */

This is also a hack, I don't really like it. I'd much prefer keeping
audio handling in separate functions.

> +	if (layer == NULL) {
> +		if (mode >= AUD2_MODE_DISABLE) {
> +			reg &= ~ZYNQMP_DISP_AV_BUF_OUTPUT_AUD2_MASK;
> +			reg |= FIELD_PREP(ZYNQMP_DISP_AV_BUF_OUTPUT_AUD2_MASK,
> +					(mode - AUD2_MODE_DISABLE));
> +		} else {
> +			reg &= ~ZYNQMP_DISP_AV_BUF_OUTPUT_AUD1_MASK;
> +			reg |= FIELD_PREP(ZYNQMP_DISP_AV_BUF_OUTPUT_AUD1_MASK, mode);
> +		}
> +	} else if (is_layer_vid(layer)) {
> +		reg &= ~ZYNQMP_DISP_AV_BUF_OUTPUT_VID1_MASK;
> +		reg |= FIELD_PREP(ZYNQMP_DISP_AV_BUF_OUTPUT_VID1_MASK, mode);
> +	} else {
> +		reg &= ~ZYNQMP_DISP_AV_BUF_OUTPUT_VID2_MASK;
> +		reg |= FIELD_PREP(ZYNQMP_DISP_AV_BUF_OUTPUT_VID2_MASK, mode);
> +	}
> +
> +	zynqmp_disp_avbuf_write(avbuf, ZYNQMP_DISP_AV_BUF_OUTPUT, reg);
>  }
>  
>  /**
> - * zynqmp_disp_avbuf_disable_audio - Disable audio
> + * zynqmp_disp_avbuf_enable_audio - Enable audio
>   * @avbuf: Audio/video buffer manager
>   *
> - * Disable all audio buffers.
> + * Enable all audio buffers.
>   */
> -static void zynqmp_disp_avbuf_disable_audio(struct zynqmp_disp_avbuf *avbuf)
> +static void zynqmp_disp_avbuf_enable_audio(struct zynqmp_disp_avbuf *avbuf)
>  {
> -	u32 val;
> -
> -	val = zynqmp_disp_avbuf_read(avbuf, ZYNQMP_DISP_AV_BUF_OUTPUT);
> -	val &= ~ZYNQMP_DISP_AV_BUF_OUTPUT_AUD1_MASK;
> -	val |= ZYNQMP_DISP_AV_BUF_OUTPUT_AUD1_DISABLE;
> -	val &= ~ZYNQMP_DISP_AV_BUF_OUTPUT_AUD2_EN;
> -	zynqmp_disp_avbuf_write(avbuf, ZYNQMP_DISP_AV_BUF_OUTPUT, val);
> +	zynqmp_disp_avbuf_output_select(avbuf, NULL, AUD1_MODE_MEM);
> +	zynqmp_disp_avbuf_output_select(avbuf, NULL, AUD2_MODE_ENABLE);
>  }
>  
>  /**
> - * zynqmp_disp_avbuf_enable_video - Enable a video layer
> + * zynqmp_disp_avbuf_disable_audio - Disable audio
>   * @avbuf: Audio/video buffer manager
> - * @layer: The layer
> - * @mode: Operating mode of layer
>   *
> - * Enable the video/graphics buffer for @layer.
> + * Disable all audio buffers.
>   */
> -static void zynqmp_disp_avbuf_enable_video(struct zynqmp_disp_avbuf *avbuf,
> -					   struct zynqmp_disp_layer *layer,
> -					   enum zynqmp_disp_layer_mode mode)
> +static void zynqmp_disp_avbuf_disable_audio(struct zynqmp_disp_avbuf *avbuf)
>  {
> -	u32 val;
> -
> -	val = zynqmp_disp_avbuf_read(avbuf, ZYNQMP_DISP_AV_BUF_OUTPUT);
> -	if (is_layer_vid(layer)) {
> -		val &= ~ZYNQMP_DISP_AV_BUF_OUTPUT_VID1_MASK;
> -		if (mode == ZYNQMP_DISP_LAYER_NONLIVE)
> -			val |= ZYNQMP_DISP_AV_BUF_OUTPUT_VID1_MEM;
> -		else
> -			val |= ZYNQMP_DISP_AV_BUF_OUTPUT_VID1_LIVE;
> -	} else {
> -		val &= ~ZYNQMP_DISP_AV_BUF_OUTPUT_VID2_MASK;
> -		val |= ZYNQMP_DISP_AV_BUF_OUTPUT_VID2_MEM;
> -		if (mode == ZYNQMP_DISP_LAYER_NONLIVE)
> -			val |= ZYNQMP_DISP_AV_BUF_OUTPUT_VID2_MEM;
> -		else
> -			val |= ZYNQMP_DISP_AV_BUF_OUTPUT_VID2_LIVE;
> -	}
> -	zynqmp_disp_avbuf_write(avbuf, ZYNQMP_DISP_AV_BUF_OUTPUT, val);
> +	zynqmp_disp_avbuf_output_select(avbuf, NULL, AUD1_MODE_DISABLE);
> +	zynqmp_disp_avbuf_output_select(avbuf, NULL, AUD2_MODE_DISABLE);
>  }
>  
>  /**
> - * zynqmp_disp_avbuf_disable_video - Disable a video layer
> - * @avbuf: Audio/video buffer manager
> + * zynqmp_disp_avbuf_set_layer_output - Set layer output
>   * @layer: The layer
> + * @mode: The layer mode
>   *
> - * Disable the video/graphics buffer for @layer.
> + * Set output for @layer
>   */
> -static void zynqmp_disp_avbuf_disable_video(struct zynqmp_disp_avbuf *avbuf,
> -					    struct zynqmp_disp_layer *layer)
> +static void zynqmp_disp_avbuf_set_layer_output(struct zynqmp_disp_layer *layer,
> +					   enum zynqmp_disp_layer_mode mode)
>  {
> -	u32 val;
> -
> -	val = zynqmp_disp_avbuf_read(avbuf, ZYNQMP_DISP_AV_BUF_OUTPUT);
> -	if (is_layer_vid(layer)) {
> -		val &= ~ZYNQMP_DISP_AV_BUF_OUTPUT_VID1_MASK;
> -		val |= ZYNQMP_DISP_AV_BUF_OUTPUT_VID1_NONE;
> -	} else {
> -		val &= ~ZYNQMP_DISP_AV_BUF_OUTPUT_VID2_MASK;
> -		val |= ZYNQMP_DISP_AV_BUF_OUTPUT_VID2_DISABLE;
> +	struct zynqmp_disp *disp = layer->disp;
> +	int val;
> +
> +	switch (mode) {
> +	case ZYNQMP_DISP_LAYER_LIVE:
> +		val = is_layer_vid(layer) ? VID_MODE_LIVE : GFX_MODE_LIVE;
> +		break;
> +	case ZYNQMP_DISP_LAYER_MEM:
> +		val = is_layer_vid(layer) ? VID_MODE_MEM : GFX_MODE_MEM;
> +		break;
> +	case ZYNQMP_DISP_LAYER_TPG:
> +		if (!is_layer_vid(layer)) {
> +			dev_err(disp->dev, "gfx layer has no tpg mode\n");
> +			return;
> +		}
> +		val = VID_MODE_TPG;
> +		break;
> +	case ZYNQMP_DISP_LAYER_DISABLE:
> +		val = is_layer_vid(layer) ? VID_MODE_NONE : GFX_MODE_DISABLE;
> +		break;
> +	default:
> +		dev_err(disp->dev, "invalid layer mode\n");
> +		return;
>  	}
> -	zynqmp_disp_avbuf_write(avbuf, ZYNQMP_DISP_AV_BUF_OUTPUT, val);
> +
> +	zynqmp_disp_avbuf_output_select(&disp->avbuf, layer, val);
>  }
>  
>  /**
> @@ -1030,11 +1067,10 @@ zynqmp_disp_layer_find_format(struct zynqmp_disp_layer *layer,
>   */
>  static void zynqmp_disp_layer_enable(struct zynqmp_disp_layer *layer)
>  {
> -	zynqmp_disp_avbuf_enable_video(&layer->disp->avbuf, layer,
> -				       ZYNQMP_DISP_LAYER_NONLIVE);
> +	zynqmp_disp_avbuf_set_layer_output(layer, ZYNQMP_DISP_LAYER_MEM);
>  	zynqmp_disp_blend_layer_enable(&layer->disp->blend, layer);
>  
> -	layer->mode = ZYNQMP_DISP_LAYER_NONLIVE;
> +	layer->mode = ZYNQMP_DISP_LAYER_MEM;
>  }
>  
>  /**
> @@ -1051,7 +1087,7 @@ static void zynqmp_disp_layer_disable(struct zynqmp_disp_layer *layer)
>  	for (i = 0; i < layer->drm_fmt->num_planes; i++)
>  		dmaengine_terminate_sync(layer->dmas[i].chan);
>  
> -	zynqmp_disp_avbuf_disable_video(&layer->disp->avbuf, layer);
> +	zynqmp_disp_avbuf_set_layer_output(layer, ZYNQMP_DISP_LAYER_DISABLE);
>  	zynqmp_disp_blend_layer_disable(&layer->disp->blend, layer);
>  }
>  
> diff --git a/drivers/gpu/drm/xlnx/zynqmp_disp_regs.h b/drivers/gpu/drm/xlnx/zynqmp_disp_regs.h
> index f92a006d5070..4316e324102d 100644
> --- a/drivers/gpu/drm/xlnx/zynqmp_disp_regs.h
> +++ b/drivers/gpu/drm/xlnx/zynqmp_disp_regs.h
> @@ -118,25 +118,10 @@
>  #define ZYNQMP_DISP_AV_BUF_STC_SNAPSHOT0		0x60
>  #define ZYNQMP_DISP_AV_BUF_STC_SNAPSHOT1		0x64
>  #define ZYNQMP_DISP_AV_BUF_OUTPUT			0x70
> -#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID1_SHIFT		0
> -#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID1_MASK		(0x3 << 0)
> -#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID1_LIVE		(0 << 0)
> -#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID1_MEM		(1 << 0)
> -#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID1_PATTERN		(2 << 0)
> -#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID1_NONE		(3 << 0)
> -#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID2_SHIFT		2
> -#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID2_MASK		(0x3 << 2)
> -#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID2_DISABLE		(0 << 2)
> -#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID2_MEM		(1 << 2)
> -#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID2_LIVE		(2 << 2)
> -#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID2_NONE		(3 << 2)
> -#define ZYNQMP_DISP_AV_BUF_OUTPUT_AUD1_SHIFT		4
> -#define ZYNQMP_DISP_AV_BUF_OUTPUT_AUD1_MASK		(0x3 << 4)
> -#define ZYNQMP_DISP_AV_BUF_OUTPUT_AUD1_PL		(0 << 4)
> -#define ZYNQMP_DISP_AV_BUF_OUTPUT_AUD1_MEM		(1 << 4)
> -#define ZYNQMP_DISP_AV_BUF_OUTPUT_AUD1_PATTERN		(2 << 4)
> -#define ZYNQMP_DISP_AV_BUF_OUTPUT_AUD1_DISABLE		(3 << 4)
> -#define ZYNQMP_DISP_AV_BUF_OUTPUT_AUD2_EN		BIT(6)
> +#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID1_MASK		GENMASK(1, 0)
> +#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID2_MASK		GENMASK(3, 2)
> +#define ZYNQMP_DISP_AV_BUF_OUTPUT_AUD1_MASK		GENMASK(5, 4)
> +#define ZYNQMP_DISP_AV_BUF_OUTPUT_AUD2_MASK		BIT(6)
>  #define ZYNQMP_DISP_AV_BUF_HCOUNT_VCOUNT_INT0		0x74
>  #define ZYNQMP_DISP_AV_BUF_HCOUNT_VCOUNT_INT1		0x78
>  #define ZYNQMP_DISP_AV_BUF_PATTERN_GEN_SELECT		0x100

Following my comment above, let's write this

#define ZYNQMP_DISP_AV_BUF_OUTPUT_LIVE			0
#define ZYNQMP_DISP_AV_BUF_OUTPUT_MEM			1
#define ZYNQMP_DISP_AV_BUF_OUTPUT_PATTERN		2
#define ZYNQMP_DISP_AV_BUF_OUTPUT_NONE			3
#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID1(v)		((v) << 0)
#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID1_MASK		GENMASK(1, 0)
#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID2(v)		((v) << 2)
#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID2_MASK		GENMASK(3, 2)
#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID3(v)		((v) << 4)
#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID3_MASK		GENMASK(5, 4)
#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID4(v)		((v) << 6)
#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID4_MASK		GENMASK(7, 6)

Or possibly better,

#define ZYNQMP_DISP_AV_BUF_OUTPUT_LIVE			0
#define ZYNQMP_DISP_AV_BUF_OUTPUT_MEM			1
#define ZYNQMP_DISP_AV_BUF_OUTPUT_PATTERN		2
#define ZYNQMP_DISP_AV_BUF_OUTPUT_NONE			3
#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID(n, v)		((v) << ((n) * 2))
#define ZYNQMP_DISP_AV_BUF_OUTPUT_VID_MASK(n)		GENMASK((n)+1, (n))
-- 
Regards,

Laurent Pinchart

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