[PATCH v4 0/2] Add writeback scaling

[PATCH v4 0/2] Add writeback scaling

[Ben Davis]

Add support for scaling on writeback. To do this add
writeback_dest_x,y,w,h writeback connector properties to specify the
desired output dimensions.
Then implement downscaling on writeback for Malidp-550 and Malidp-650
(upscaling on writeback is not supported on these devices).

v2: Use 0 as default for writeback_w,h and so update range to use 1 as
    minimum.

v3: Rename properties to specify they are destination width/height.
    Make sure the values from the properties are passed to
    enable_memwrite rather than the framebuffer dimensions.

v4: Add writeback_dest_x,y properties as well for consistency with
    plane properties.
    Writing to arbitrary x,y on writeback is not supported on the
    hardware so we simulate this in the driver.
    Clear the properties on duplicate state for robustness.
    Use 0 as minimum for all added properties.
    Also actually make sure the values from the properties are passed
    to enable_memwrite as intended in v3 and some other clean up.

Ben Davis (2):
  drm: Add writeback_dest_x,y,w,h properties
  drm/malidp: Enable writeback scaling

 drivers/gpu/drm/arm/malidp_crtc.c         |  47 ++++++------
 drivers/gpu/drm/arm/malidp_drv.c          |  10 ++-
 drivers/gpu/drm/arm/malidp_drv.h          |   2 +
 drivers/gpu/drm/arm/malidp_hw.c           |  45 ++++++++----
 drivers/gpu/drm/arm/malidp_hw.h           |  19 ++++-
 drivers/gpu/drm/arm/malidp_mw.c           | 117 ++++++++++++++++++++++++------
 drivers/gpu/drm/arm/malidp_regs.h         |   1 +
 drivers/gpu/drm/drm_atomic_state_helper.c |   6 ++
 drivers/gpu/drm/drm_atomic_uapi.c         |  17 +++++
 drivers/gpu/drm/drm_writeback.c           |  66 +++++++++++++++++
 include/drm/drm_connector.h               |  23 ++++++
 include/drm/drm_mode_config.h             |  20 +++++
 12 files changed, 308 insertions(+), 65 deletions(-)

-- 
2.7.4

[PATCH v4 1/2] drm: Add writeback_dest_x,y,w,h properties

[Ben Davis]

Add new properties to specify x,y coordinates and
width and height for writeback.

These are reset to 0 on duplicating state to provide
robustness against accidental scaling.

Signed-off-by: Ben Davis <ben.davis@arm.com>
---
 drivers/gpu/drm/drm_atomic_state_helper.c |  6 +++
 drivers/gpu/drm/drm_atomic_uapi.c         | 17 ++++++++
 drivers/gpu/drm/drm_writeback.c           | 66 +++++++++++++++++++++++++++++++
 include/drm/drm_connector.h               | 23 +++++++++++
 include/drm/drm_mode_config.h             | 20 ++++++++++
 5 files changed, 132 insertions(+)

diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c
index 25a95b9..5973ca3 100644
--- a/drivers/gpu/drm/drm_atomic_state_helper.c
+++ b/drivers/gpu/drm/drm_atomic_state_helper.c
@@ -382,6 +382,12 @@ __drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector,
 
 	/* Don't copy over a writeback job, they are used only once */
 	state->writeback_job = NULL;
+
+	/* Auto clear writeback coordinates, should only be used once */
+	state->writeback_dest_x = 0;
+	state->writeback_dest_y = 0;
+	state->writeback_dest_w = 0;
+	state->writeback_dest_h = 0;
 }
 EXPORT_SYMBOL(__drm_atomic_helper_connector_duplicate_state);
 
diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
index d520a04..7d3fb7f 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -765,6 +765,14 @@ static int drm_atomic_connector_set_property(struct drm_connector *connector,
 			return -EINVAL;
 		}
 		state->content_protection = val;
+	} else if (property == config->prop_writeback_dest_x) {
+		state->writeback_dest_x = val;
+	} else if (property == config->prop_writeback_dest_y) {
+		state->writeback_dest_y = val;
+	} else if (property == config->prop_writeback_dest_w) {
+		state->writeback_dest_w = val;
+	} else if (property == config->prop_writeback_dest_h) {
+		state->writeback_dest_h = val;
 	} else if (property == config->writeback_fb_id_property) {
 		struct drm_framebuffer *fb = drm_framebuffer_lookup(dev, NULL, val);
 		int ret = drm_atomic_set_writeback_fb_for_connector(state, fb);
@@ -837,6 +845,15 @@ drm_atomic_connector_get_property(struct drm_connector *connector,
 		*val = state->scaling_mode;
 	} else if (property == connector->content_protection_property) {
 		*val = state->content_protection;
+	} else if (property == config->prop_writeback_dest_x) {
+		/* Auto clear wb co-ordinates to prevent accidental scaling */
+		*val = 0;
+	} else if (property == config->prop_writeback_dest_y) {
+		*val = 0;
+	} else if (property == config->prop_writeback_dest_w) {
+		*val = 0;
+	} else if (property == config->prop_writeback_dest_h) {
+		*val = 0;
 	} else if (property == config->writeback_fb_id_property) {
 		/* Writeback framebuffer is one-shot, write and forget */
 		*val = 0;
diff --git a/drivers/gpu/drm/drm_writeback.c b/drivers/gpu/drm/drm_writeback.c
index c20e6fe..7c53abd 100644
--- a/drivers/gpu/drm/drm_writeback.c
+++ b/drivers/gpu/drm/drm_writeback.c
@@ -74,6 +74,30 @@
  *	applications making use of writeback connectors *always* retrieve an
  *	out-fence for the commit and use it appropriately.
  *	From userspace, this property will always read as zero.
+ *
+ *  "WRITEBACK_DEST_X":
+ *	The x-coordinate to write back onto the output writeback framebuffer.
+ *	0 acts as default. If non-zero the composition will be translated
+ *	horizontally in the buffer by the amount specified. This is the case
+ *	even if not scaling on writeback.
+ *
+ *  "WRITEBACK_DEST_Y":
+ *	The y-coordinate to write back onto the output writeback framebuffer.
+ *	0 acts as default. If non-zero the composition will be translated
+ *	vertically in the buffer by the amount specified. This is the case even
+ *	if not scaling on writeback.
+ *
+ *  "WRITEBACK_DEST_W":
+ *	The width of the composition to write back. 0 acts as default. If
+ *	non-zero the composition will be scaled to match the given width.
+ *	If scaling both WRITEBACK_DEST_W and WRITEBACK_DEST_H should be
+ *	set as non-zero.
+ *
+ *  "WRITEBACK_DEST_H":
+ *	The height of the composition to write back. 0 acts as default. If
+ *	non-zero the composition will be scaled to match the given height.
+ *	If scaling both WRITEBACK_DEST_W and WRITEBACK_DEST_H should be
+ *	set as non-zero.
  */
 
 #define fence_to_wb_connector(x) container_of(x->lock, \
@@ -141,6 +165,38 @@ static int create_writeback_properties(struct drm_device *dev)
 		dev->mode_config.writeback_out_fence_ptr_property = prop;
 	}
 
+	if (!dev->mode_config.prop_writeback_dest_x) {
+		prop = drm_property_create_range(dev, DRM_MODE_PROP_ATOMIC,
+						 "WRITEBACK_DEST_X", 0, UINT_MAX);
+		if (!prop)
+			return -ENOMEM;
+		dev->mode_config.prop_writeback_dest_x = prop;
+	}
+
+	if (!dev->mode_config.prop_writeback_dest_y) {
+		prop = drm_property_create_range(dev, DRM_MODE_PROP_ATOMIC,
+						 "WRITEBACK_DEST_Y", 0, UINT_MAX);
+		if (!prop)
+			return -ENOMEM;
+		dev->mode_config.prop_writeback_dest_y = prop;
+	}
+
+	if (!dev->mode_config.prop_writeback_dest_w) {
+		prop = drm_property_create_range(dev, DRM_MODE_PROP_ATOMIC,
+						 "WRITEBACK_DEST_W", 0, UINT_MAX);
+		if (!prop)
+			return -ENOMEM;
+		dev->mode_config.prop_writeback_dest_w = prop;
+	}
+
+	if (!dev->mode_config.prop_writeback_dest_h) {
+		prop = drm_property_create_range(dev, DRM_MODE_PROP_ATOMIC,
+						 "WRITEBACK_DEST_H", 0, UINT_MAX);
+		if (!prop)
+			return -ENOMEM;
+		dev->mode_config.prop_writeback_dest_h = prop;
+	}
+
 	return 0;
 }
 
@@ -225,6 +281,16 @@ int drm_writeback_connector_init(struct drm_device *dev,
 	drm_object_attach_property(&connector->base,
 				   config->writeback_pixel_formats_property,
 				   blob->base.id);
+
+	drm_object_attach_property(&connector->base,
+				   config->prop_writeback_dest_x, 0);
+	drm_object_attach_property(&connector->base,
+				   config->prop_writeback_dest_y, 0);
+	drm_object_attach_property(&connector->base,
+				   config->prop_writeback_dest_w, 0);
+	drm_object_attach_property(&connector->base,
+				   config->prop_writeback_dest_h, 0);
+
 	wb_connector->pixel_formats_blob_ptr = blob;
 
 	return 0;
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 8fe22ab..4c7701e 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -515,6 +515,25 @@ struct drm_connector_state {
 	 */
 	struct drm_writeback_job *writeback_job;
 
+	/** @writeback_dest_x: x coord to write plane to on wb buffer
+	 *  The written back composition will be translated by this
+	 *  amount horizontally on the output buffer.
+	 */
+	/** @writeback_dest_y: y coord to write plane to on wb buffer
+	 *  The written back composition will be translated by this
+	 *  amount vertically on the output buffer.
+	 */
+	/** @writeback_dest_w: width of plane to write to wb buffer
+	 *  The written back composition will be scaled to match this
+	 *  height dimension on the output buffer. Ignored if 0.
+	 */
+	/** @writeback_dest_h: height of plane to write to wb buffer
+	 *  The written back composition will be scaled to match this
+	 *  width dimension on the output buffer. Ignored if 0.
+	 */
+	uint32_t writeback_dest_x, writeback_dest_y,
+		 writeback_dest_w, writeback_dest_h;
+
 	/**
 	 * @max_requested_bpc: Connector property to limit the maximum bit
 	 * depth of the pixels.
@@ -704,6 +723,10 @@ struct drm_connector_funcs {
 	 * cleaned up by calling the @atomic_destroy_state hook in this
 	 * structure.
 	 *
+	 * State relating to writeback including writeback_job and
+	 * writeback_dest_x,y,w,h is not intended to be reused and so will not
+	 * be duplicated and will instead be reset to NULL/0 respectively.
+	 *
 	 * This callback is mandatory for atomic drivers.
 	 *
 	 * Atomic drivers which don't subclass &struct drm_connector_state should use
diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
index 7f60e8e..40ce4a8 100644
--- a/include/drm/drm_mode_config.h
+++ b/include/drm/drm_mode_config.h
@@ -622,6 +622,26 @@ struct drm_mode_config {
 	 */
 	struct drm_property *prop_crtc_h;
 	/**
+	 * @prop_writeback_dest_x: Writeback connector property for the crtc
+	 * output destination position in the writeback buffer.
+	 */
+	struct drm_property *prop_writeback_dest_x;
+	/**
+	 * @prop_writeback_dest_y: Writeback connector property for the crtc
+	 * output destination position in the writeback buffer.
+	 */
+	struct drm_property *prop_writeback_dest_y;
+	/**
+	 * @prop_writeback_dest_w: Writeback connector property for the crtc
+	 * output destination position in the writeback buffer.
+	 */
+	struct drm_property *prop_writeback_dest_w;
+	/**
+	 * @prop_writeback_dest_h: Writeback connector property for the crtc
+	 * output destination position in the writeback buffer.
+	 */
+	struct drm_property *prop_writeback_dest_h;
+	/**
 	 * @prop_fb_id: Default atomic plane property to specify the
 	 * &drm_framebuffer.
 	 */
-- 
2.7.4

Re: [PATCH v4 1/2] drm: Add writeback_dest_x,y,w,h properties

[Liviu Dudau]

On Thu, May 02, 2019 at 05:10:09PM +0100, Ben Davis wrote:
> Add new properties to specify x,y coordinates and
> width and height for writeback.
> 
> These are reset to 0 on duplicating state to provide
> robustness against accidental scaling.
> 
> Signed-off-by: Ben Davis <ben.davis@arm.com>

Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>

Best regards,
Liviu

> ---
>  drivers/gpu/drm/drm_atomic_state_helper.c |  6 +++
>  drivers/gpu/drm/drm_atomic_uapi.c         | 17 ++++++++
>  drivers/gpu/drm/drm_writeback.c           | 66 +++++++++++++++++++++++++++++++
>  include/drm/drm_connector.h               | 23 +++++++++++
>  include/drm/drm_mode_config.h             | 20 ++++++++++
>  5 files changed, 132 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c
> index 25a95b9..5973ca3 100644
> --- a/drivers/gpu/drm/drm_atomic_state_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_state_helper.c
> @@ -382,6 +382,12 @@ __drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector,
>  
>  	/* Don't copy over a writeback job, they are used only once */
>  	state->writeback_job = NULL;
> +
> +	/* Auto clear writeback coordinates, should only be used once */
> +	state->writeback_dest_x = 0;
> +	state->writeback_dest_y = 0;
> +	state->writeback_dest_w = 0;
> +	state->writeback_dest_h = 0;
>  }
>  EXPORT_SYMBOL(__drm_atomic_helper_connector_duplicate_state);
>  
> diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
> index d520a04..7d3fb7f 100644
> --- a/drivers/gpu/drm/drm_atomic_uapi.c
> +++ b/drivers/gpu/drm/drm_atomic_uapi.c
> @@ -765,6 +765,14 @@ static int drm_atomic_connector_set_property(struct drm_connector *connector,
>  			return -EINVAL;
>  		}
>  		state->content_protection = val;
> +	} else if (property == config->prop_writeback_dest_x) {
> +		state->writeback_dest_x = val;
> +	} else if (property == config->prop_writeback_dest_y) {
> +		state->writeback_dest_y = val;
> +	} else if (property == config->prop_writeback_dest_w) {
> +		state->writeback_dest_w = val;
> +	} else if (property == config->prop_writeback_dest_h) {
> +		state->writeback_dest_h = val;
>  	} else if (property == config->writeback_fb_id_property) {
>  		struct drm_framebuffer *fb = drm_framebuffer_lookup(dev, NULL, val);
>  		int ret = drm_atomic_set_writeback_fb_for_connector(state, fb);
> @@ -837,6 +845,15 @@ drm_atomic_connector_get_property(struct drm_connector *connector,
>  		*val = state->scaling_mode;
>  	} else if (property == connector->content_protection_property) {
>  		*val = state->content_protection;
> +	} else if (property == config->prop_writeback_dest_x) {
> +		/* Auto clear wb co-ordinates to prevent accidental scaling */
> +		*val = 0;
> +	} else if (property == config->prop_writeback_dest_y) {
> +		*val = 0;
> +	} else if (property == config->prop_writeback_dest_w) {
> +		*val = 0;
> +	} else if (property == config->prop_writeback_dest_h) {
> +		*val = 0;
>  	} else if (property == config->writeback_fb_id_property) {
>  		/* Writeback framebuffer is one-shot, write and forget */
>  		*val = 0;
> diff --git a/drivers/gpu/drm/drm_writeback.c b/drivers/gpu/drm/drm_writeback.c
> index c20e6fe..7c53abd 100644
> --- a/drivers/gpu/drm/drm_writeback.c
> +++ b/drivers/gpu/drm/drm_writeback.c
> @@ -74,6 +74,30 @@
>   *	applications making use of writeback connectors *always* retrieve an
>   *	out-fence for the commit and use it appropriately.
>   *	From userspace, this property will always read as zero.
> + *
> + *  "WRITEBACK_DEST_X":
> + *	The x-coordinate to write back onto the output writeback framebuffer.
> + *	0 acts as default. If non-zero the composition will be translated
> + *	horizontally in the buffer by the amount specified. This is the case
> + *	even if not scaling on writeback.
> + *
> + *  "WRITEBACK_DEST_Y":
> + *	The y-coordinate to write back onto the output writeback framebuffer.
> + *	0 acts as default. If non-zero the composition will be translated
> + *	vertically in the buffer by the amount specified. This is the case even
> + *	if not scaling on writeback.
> + *
> + *  "WRITEBACK_DEST_W":
> + *	The width of the composition to write back. 0 acts as default. If
> + *	non-zero the composition will be scaled to match the given width.
> + *	If scaling both WRITEBACK_DEST_W and WRITEBACK_DEST_H should be
> + *	set as non-zero.
> + *
> + *  "WRITEBACK_DEST_H":
> + *	The height of the composition to write back. 0 acts as default. If
> + *	non-zero the composition will be scaled to match the given height.
> + *	If scaling both WRITEBACK_DEST_W and WRITEBACK_DEST_H should be
> + *	set as non-zero.
>   */
>  
>  #define fence_to_wb_connector(x) container_of(x->lock, \
> @@ -141,6 +165,38 @@ static int create_writeback_properties(struct drm_device *dev)
>  		dev->mode_config.writeback_out_fence_ptr_property = prop;
>  	}
>  
> +	if (!dev->mode_config.prop_writeback_dest_x) {
> +		prop = drm_property_create_range(dev, DRM_MODE_PROP_ATOMIC,
> +						 "WRITEBACK_DEST_X", 0, UINT_MAX);
> +		if (!prop)
> +			return -ENOMEM;
> +		dev->mode_config.prop_writeback_dest_x = prop;
> +	}
> +
> +	if (!dev->mode_config.prop_writeback_dest_y) {
> +		prop = drm_property_create_range(dev, DRM_MODE_PROP_ATOMIC,
> +						 "WRITEBACK_DEST_Y", 0, UINT_MAX);
> +		if (!prop)
> +			return -ENOMEM;
> +		dev->mode_config.prop_writeback_dest_y = prop;
> +	}
> +
> +	if (!dev->mode_config.prop_writeback_dest_w) {
> +		prop = drm_property_create_range(dev, DRM_MODE_PROP_ATOMIC,
> +						 "WRITEBACK_DEST_W", 0, UINT_MAX);
> +		if (!prop)
> +			return -ENOMEM;
> +		dev->mode_config.prop_writeback_dest_w = prop;
> +	}
> +
> +	if (!dev->mode_config.prop_writeback_dest_h) {
> +		prop = drm_property_create_range(dev, DRM_MODE_PROP_ATOMIC,
> +						 "WRITEBACK_DEST_H", 0, UINT_MAX);
> +		if (!prop)
> +			return -ENOMEM;
> +		dev->mode_config.prop_writeback_dest_h = prop;
> +	}
> +
>  	return 0;
>  }
>  
> @@ -225,6 +281,16 @@ int drm_writeback_connector_init(struct drm_device *dev,
>  	drm_object_attach_property(&connector->base,
>  				   config->writeback_pixel_formats_property,
>  				   blob->base.id);
> +
> +	drm_object_attach_property(&connector->base,
> +				   config->prop_writeback_dest_x, 0);
> +	drm_object_attach_property(&connector->base,
> +				   config->prop_writeback_dest_y, 0);
> +	drm_object_attach_property(&connector->base,
> +				   config->prop_writeback_dest_w, 0);
> +	drm_object_attach_property(&connector->base,
> +				   config->prop_writeback_dest_h, 0);
> +
>  	wb_connector->pixel_formats_blob_ptr = blob;
>  
>  	return 0;
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index 8fe22ab..4c7701e 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -515,6 +515,25 @@ struct drm_connector_state {
>  	 */
>  	struct drm_writeback_job *writeback_job;
>  
> +	/** @writeback_dest_x: x coord to write plane to on wb buffer
> +	 *  The written back composition will be translated by this
> +	 *  amount horizontally on the output buffer.
> +	 */
> +	/** @writeback_dest_y: y coord to write plane to on wb buffer
> +	 *  The written back composition will be translated by this
> +	 *  amount vertically on the output buffer.
> +	 */
> +	/** @writeback_dest_w: width of plane to write to wb buffer
> +	 *  The written back composition will be scaled to match this
> +	 *  height dimension on the output buffer. Ignored if 0.
> +	 */
> +	/** @writeback_dest_h: height of plane to write to wb buffer
> +	 *  The written back composition will be scaled to match this
> +	 *  width dimension on the output buffer. Ignored if 0.
> +	 */
> +	uint32_t writeback_dest_x, writeback_dest_y,
> +		 writeback_dest_w, writeback_dest_h;
> +
>  	/**
>  	 * @max_requested_bpc: Connector property to limit the maximum bit
>  	 * depth of the pixels.
> @@ -704,6 +723,10 @@ struct drm_connector_funcs {
>  	 * cleaned up by calling the @atomic_destroy_state hook in this
>  	 * structure.
>  	 *
> +	 * State relating to writeback including writeback_job and
> +	 * writeback_dest_x,y,w,h is not intended to be reused and so will not
> +	 * be duplicated and will instead be reset to NULL/0 respectively.
> +	 *
>  	 * This callback is mandatory for atomic drivers.
>  	 *
>  	 * Atomic drivers which don't subclass &struct drm_connector_state should use
> diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
> index 7f60e8e..40ce4a8 100644
> --- a/include/drm/drm_mode_config.h
> +++ b/include/drm/drm_mode_config.h
> @@ -622,6 +622,26 @@ struct drm_mode_config {
>  	 */
>  	struct drm_property *prop_crtc_h;
>  	/**
> +	 * @prop_writeback_dest_x: Writeback connector property for the crtc
> +	 * output destination position in the writeback buffer.
> +	 */
> +	struct drm_property *prop_writeback_dest_x;
> +	/**
> +	 * @prop_writeback_dest_y: Writeback connector property for the crtc
> +	 * output destination position in the writeback buffer.
> +	 */
> +	struct drm_property *prop_writeback_dest_y;
> +	/**
> +	 * @prop_writeback_dest_w: Writeback connector property for the crtc
> +	 * output destination position in the writeback buffer.
> +	 */
> +	struct drm_property *prop_writeback_dest_w;
> +	/**
> +	 * @prop_writeback_dest_h: Writeback connector property for the crtc
> +	 * output destination position in the writeback buffer.
> +	 */
> +	struct drm_property *prop_writeback_dest_h;
> +	/**
>  	 * @prop_fb_id: Default atomic plane property to specify the
>  	 * &drm_framebuffer.
>  	 */
> -- 
> 2.7.4
> 

-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
  ---------------
    ¯\_(ツ)_/¯

[PATCH v4 2/2] drm/malidp: Enable writeback scaling

[Ben Davis]

The phase setting part of malidp_crtc_atomic_check_scaling is refactored
to allow use in writeback scaling.

Also the enable_memwrite function prototype is simplified by directly
passing mw_state.

Signed-off-by: Ben Davis <ben.davis@arm.com>
---
 drivers/gpu/drm/arm/malidp_crtc.c |  47 ++++++++-------
 drivers/gpu/drm/arm/malidp_drv.c  |  10 +++-
 drivers/gpu/drm/arm/malidp_drv.h  |   2 +
 drivers/gpu/drm/arm/malidp_hw.c   |  45 ++++++++++-----
 drivers/gpu/drm/arm/malidp_hw.h   |  19 ++++++-
 drivers/gpu/drm/arm/malidp_mw.c   | 117 ++++++++++++++++++++++++++++++--------
 drivers/gpu/drm/arm/malidp_regs.h |   1 +
 7 files changed, 176 insertions(+), 65 deletions(-)

diff --git a/drivers/gpu/drm/arm/malidp_crtc.c b/drivers/gpu/drm/arm/malidp_crtc.c
index 3f65996..6548859 100644
--- a/drivers/gpu/drm/arm/malidp_crtc.c
+++ b/drivers/gpu/drm/arm/malidp_crtc.c
@@ -265,6 +265,29 @@ static int malidp_crtc_atomic_check_ctm(struct drm_crtc *crtc,
 	return 0;
 }
 
+void malidp_set_se_config_phase(struct malidp_se_config *s)
+{
+#define SE_N_PHASE 4
+#define SE_SHIFT_N_PHASE 12
+	u32 phase;
+
+	/* Calculate initial_phase and delta_phase for horizontal. */
+	phase = s->input_w;
+	s->h_init_phase = ((phase << SE_N_PHASE) / s->output_w + 1) / 2;
+
+	phase <<= (SE_SHIFT_N_PHASE + SE_N_PHASE);
+	s->h_delta_phase = phase / s->output_w;
+
+	/* Same for vertical. */
+	phase = s->input_h;
+	s->v_init_phase = ((phase << SE_N_PHASE) / s->output_h + 1) / 2;
+
+	phase <<= (SE_SHIFT_N_PHASE + SE_N_PHASE);
+	s->v_delta_phase = phase / s->output_h;
+#undef SE_N_PHASE
+#undef SE_SHIFT_N_PHASE
+}
+
 static int malidp_crtc_atomic_check_scaling(struct drm_crtc *crtc,
 					    struct drm_crtc_state *state)
 {
@@ -291,7 +314,6 @@ static int malidp_crtc_atomic_check_scaling(struct drm_crtc *crtc,
 
 	drm_atomic_crtc_state_for_each_plane_state(plane, pstate, state) {
 		struct malidp_plane *mp = to_malidp_plane(plane);
-		u32 phase;
 
 		if (!(mp->layer->id & scaling))
 			continue;
@@ -319,27 +341,8 @@ static int malidp_crtc_atomic_check_scaling(struct drm_crtc *crtc,
 		s->output_w = pstate->crtc_w;
 		s->output_h = pstate->crtc_h;
 
-#define SE_N_PHASE 4
-#define SE_SHIFT_N_PHASE 12
-		/* Calculate initial_phase and delta_phase for horizontal. */
-		phase = s->input_w;
-		s->h_init_phase =
-				((phase << SE_N_PHASE) / s->output_w + 1) / 2;
-
-		phase = s->input_w;
-		phase <<= (SE_SHIFT_N_PHASE + SE_N_PHASE);
-		s->h_delta_phase = phase / s->output_w;
-
-		/* Same for vertical. */
-		phase = s->input_h;
-		s->v_init_phase =
-				((phase << SE_N_PHASE) / s->output_h + 1) / 2;
-
-		phase = s->input_h;
-		phase <<= (SE_SHIFT_N_PHASE + SE_N_PHASE);
-		s->v_delta_phase = phase / s->output_h;
-#undef SE_N_PHASE
-#undef SE_SHIFT_N_PHASE
+
+		malidp_set_se_config_phase(s);
 		s->plane_src_id = mp->layer->id;
 	}
 
diff --git a/drivers/gpu/drm/arm/malidp_drv.c b/drivers/gpu/drm/arm/malidp_drv.c
index d37ff9d..e2465e9 100644
--- a/drivers/gpu/drm/arm/malidp_drv.c
+++ b/drivers/gpu/drm/arm/malidp_drv.c
@@ -138,7 +138,7 @@ static void malidp_atomic_commit_se_config(struct drm_crtc *crtc,
 	u32 val;
 
 	/* Set SE_CONTROL */
-	if (!s->scale_enable) {
+	if (!s->scale_enable && !s->wb_scale_enable) {
 		val = malidp_hw_read(hwdev, se_control);
 		val &= ~MALIDP_SE_SCALING_EN;
 		malidp_hw_write(hwdev, val, se_control);
@@ -147,12 +147,16 @@ static void malidp_atomic_commit_se_config(struct drm_crtc *crtc,
 
 	hwdev->hw->se_set_scaling_coeffs(hwdev, s, old_s);
 	val = malidp_hw_read(hwdev, se_control);
-	val |= MALIDP_SE_SCALING_EN | MALIDP_SE_ALPHA_EN;
+	val |= MALIDP_SE_SCALING_EN;
 
 	val &= ~MALIDP_SE_ENH(MALIDP_SE_ENH_MASK);
 	val |= s->enhancer_enable ? MALIDP_SE_ENH(3) : 0;
 
-	val |= MALIDP_SE_RGBO_IF_EN;
+	if (s->scale_enable)
+		val |= (MALIDP_SE_RGBO_IF_EN | MALIDP_SE_ALPHA_EN);
+	else
+		val &= ~((MALIDP_SE_RGBO_IF_EN | MALIDP_SE_ALPHA_EN));
+
 	malidp_hw_write(hwdev, val, se_control);
 
 	/* Set IN_SIZE & OUT_SIZE. */
diff --git a/drivers/gpu/drm/arm/malidp_drv.h b/drivers/gpu/drm/arm/malidp_drv.h
index 391d6ff..924f831 100644
--- a/drivers/gpu/drm/arm/malidp_drv.h
+++ b/drivers/gpu/drm/arm/malidp_drv.h
@@ -104,6 +104,8 @@ struct malidp_crtc_state {
 int malidp_de_planes_init(struct drm_device *drm);
 int malidp_crtc_init(struct drm_device *drm);
 
+void malidp_set_se_config_phase(struct malidp_se_config *s);
+
 bool malidp_hw_format_is_linear_only(u32 format);
 bool malidp_hw_format_is_afbc_only(u32 format);
 
diff --git a/drivers/gpu/drm/arm/malidp_hw.c b/drivers/gpu/drm/arm/malidp_hw.c
index 1a36718..6f59c0e 100644
--- a/drivers/gpu/drm/arm/malidp_hw.c
+++ b/drivers/gpu/drm/arm/malidp_hw.c
@@ -497,13 +497,18 @@ static long malidp500_se_calc_mclk(struct malidp_hw_device *hwdev,
 	return ret;
 }
 
-static int malidp500_enable_memwrite(struct malidp_hw_device *hwdev,
-				     dma_addr_t *addrs, s32 *pitches,
-				     int num_planes, u16 w, u16 h, u32 fmt_id,
-				     const s16 *rgb2yuv_coeffs)
+static int malidp500_enable_memwrite(struct malidp_hw_device *hwdev, u16 w, u16 h,
+				     struct malidp_mw_connector_state *mw_state)
 {
+
+	int num_planes = mw_state->n_planes;
+	dma_addr_t *addrs = mw_state->addrs;
+	s32 *pitches = mw_state->pitches;
+	u32 fmt_id = mw_state->format;
 	u32 base = MALIDP500_SE_MEMWRITE_BASE;
 	u32 de_base = malidp_get_block_base(hwdev, MALIDP_DE_BLOCK);
+	const s16 *rgb2yuv_coeffs = !mw_state->rgb2yuv_initialized ?
+					mw_state->rgb2yuv_coeffs : NULL;
 
 	/* enable the scaling engine block */
 	malidp_hw_setbits(hwdev, MALIDP_SCALE_ENGINE_EN, de_base + MALIDP_DE_DISPLAY_FUNC);
@@ -847,13 +852,18 @@ static long malidp550_se_calc_mclk(struct malidp_hw_device *hwdev,
 	return ret;
 }
 
-static int malidp550_enable_memwrite(struct malidp_hw_device *hwdev,
-				     dma_addr_t *addrs, s32 *pitches,
-				     int num_planes, u16 w, u16 h, u32 fmt_id,
-				     const s16 *rgb2yuv_coeffs)
+static int malidp550_enable_memwrite(struct malidp_hw_device *hwdev, u16 w, u16 h,
+				     struct malidp_mw_connector_state *mw_state)
 {
+	int num_planes = mw_state->n_planes;
+	bool scaling = mw_state->wb_scale_enable;
+	dma_addr_t *addrs = mw_state->addrs;
+	s32 *pitches = mw_state->pitches;
+	u32 fmt_id = mw_state->format;
 	u32 base = MALIDP550_SE_MEMWRITE_BASE;
 	u32 de_base = malidp_get_block_base(hwdev, MALIDP_DE_BLOCK);
+	const s16 *rgb2yuv_coeffs = !mw_state->rgb2yuv_initialized ?
+					mw_state->rgb2yuv_coeffs : NULL;
 
 	/* enable the scaling engine block */
 	malidp_hw_setbits(hwdev, MALIDP_SCALE_ENGINE_EN, de_base + MALIDP_DE_DISPLAY_FUNC);
@@ -876,10 +886,18 @@ static int malidp550_enable_memwrite(struct malidp_hw_device *hwdev,
 		WARN(1, "Invalid number of planes");
 	}
 
-	malidp_hw_write(hwdev, MALIDP_DE_H_ACTIVE(w) | MALIDP_DE_V_ACTIVE(h),
-			MALIDP550_SE_MEMWRITE_OUT_SIZE);
-	malidp_hw_setbits(hwdev, MALIDP550_SE_MEMWRITE_ONESHOT | MALIDP_SE_MEMWRITE_EN,
-			  MALIDP550_SE_CONTROL);
+	malidp_hw_clearbits(hwdev, MALIDP_SE_MEMWRITE_EN | MALIDP_SE_MEMWRITE_SCL_EN,
+			    MALIDP550_SE_CONTROL);
+
+	if (scaling) {
+		malidp_hw_setbits(hwdev, MALIDP550_SE_MEMWRITE_ONESHOT | MALIDP_SE_MEMWRITE_SCL_EN,
+				  MALIDP550_SE_CONTROL);
+	} else {
+		malidp_hw_write(hwdev, MALIDP_DE_H_ACTIVE(w) | MALIDP_DE_V_ACTIVE(h),
+				MALIDP550_SE_MEMWRITE_OUT_SIZE);
+		malidp_hw_setbits(hwdev, MALIDP550_SE_MEMWRITE_ONESHOT | MALIDP_SE_MEMWRITE_EN,
+				  MALIDP550_SE_CONTROL);
+	}
 
 	if (rgb2yuv_coeffs) {
 		int i;
@@ -897,7 +915,8 @@ static void malidp550_disable_memwrite(struct malidp_hw_device *hwdev)
 {
 	u32 base = malidp_get_block_base(hwdev, MALIDP_DE_BLOCK);
 
-	malidp_hw_clearbits(hwdev, MALIDP550_SE_MEMWRITE_ONESHOT | MALIDP_SE_MEMWRITE_EN,
+	malidp_hw_clearbits(hwdev,
+			    MALIDP550_SE_MEMWRITE_ONESHOT | MALIDP_SE_MEMWRITE_EN | MALIDP_SE_MEMWRITE_SCL_EN,
 			    MALIDP550_SE_CONTROL);
 	malidp_hw_clearbits(hwdev, MALIDP_SCALE_ENGINE_EN, base + MALIDP_DE_DISPLAY_FUNC);
 }
diff --git a/drivers/gpu/drm/arm/malidp_hw.h b/drivers/gpu/drm/arm/malidp_hw.h
index 8352a2e..61ddcb5 100644
--- a/drivers/gpu/drm/arm/malidp_hw.h
+++ b/drivers/gpu/drm/arm/malidp_hw.h
@@ -85,6 +85,7 @@ enum malidp_scaling_coeff_set {
 struct malidp_se_config {
 	u8 scale_enable : 1;
 	u8 enhancer_enable : 1;
+	u8 wb_scale_enable : 1;
 	u8 hcoeff : 3;
 	u8 vcoeff : 3;
 	u8 plane_src_id;
@@ -94,6 +95,19 @@ struct malidp_se_config {
 	u32 v_init_phase, v_delta_phase;
 };
 
+#define to_mw_state(_state) (struct malidp_mw_connector_state *)(_state)
+
+struct malidp_mw_connector_state {
+	struct drm_connector_state base;
+	dma_addr_t addrs[2];
+	s32 pitches[2];
+	u8 format;
+	u8 n_planes;
+	bool rgb2yuv_initialized;
+	const s16 *rgb2yuv_coeffs;
+	bool wb_scale_enable;
+};
+
 /* regmap features */
 #define MALIDP_REGMAP_HAS_CLEARIRQ				BIT(0)
 #define MALIDP_DEVICE_AFBC_SUPPORT_SPLIT			BIT(1)
@@ -206,9 +220,8 @@ struct malidp_hw {
 	 * @param h - height of the output frame
 	 * @param fmt_id - internal format ID of output buffer
 	 */
-	int (*enable_memwrite)(struct malidp_hw_device *hwdev, dma_addr_t *addrs,
-			       s32 *pitches, int num_planes, u16 w, u16 h, u32 fmt_id,
-			       const s16 *rgb2yuv_coeffs);
+	int (*enable_memwrite)(struct malidp_hw_device *hwdev, u16 w, u16 h,
+			       struct malidp_mw_connector_state *mw_state);
 
 	/*
 	 * Disable the writing to memory of the next frame's content.
diff --git a/drivers/gpu/drm/arm/malidp_mw.c b/drivers/gpu/drm/arm/malidp_mw.c
index 2865f7a..f1ad588 100644
--- a/drivers/gpu/drm/arm/malidp_mw.c
+++ b/drivers/gpu/drm/arm/malidp_mw.c
@@ -13,23 +13,12 @@
 #include <drm/drm_gem_cma_helper.h>
 #include <drm/drmP.h>
 #include <drm/drm_writeback.h>
+#include <video/videomode.h>
 
 #include "malidp_drv.h"
 #include "malidp_hw.h"
 #include "malidp_mw.h"
 
-#define to_mw_state(_state) (struct malidp_mw_connector_state *)(_state)
-
-struct malidp_mw_connector_state {
-	struct drm_connector_state base;
-	dma_addr_t addrs[2];
-	s32 pitches[2];
-	u8 format;
-	u8 n_planes;
-	bool rgb2yuv_initialized;
-	const s16 *rgb2yuv_coeffs;
-};
-
 static int malidp_mw_connector_get_modes(struct drm_connector *connector)
 {
 	struct drm_device *dev = connector->dev;
@@ -126,19 +115,91 @@ malidp_mw_encoder_atomic_check(struct drm_encoder *encoder,
 			       struct drm_connector_state *conn_state)
 {
 	struct malidp_mw_connector_state *mw_state = to_mw_state(conn_state);
+	struct malidp_crtc_state *cs = to_malidp_crtc_state(crtc_state);
+	struct malidp_se_config *s = &cs->scaler_config;
 	struct malidp_drm *malidp = encoder->dev->dev_private;
 	struct drm_framebuffer *fb;
-	int i, n_planes;
+	int i, n_planes, ret;
+	struct malidp_hw_device *hwdev = malidp->dev;
+	struct videomode vm;
+	u32 h_upscale_factor = 0; /* U16.16 */
+	u32 v_upscale_factor = 0; /* U16.16 */
+
+	s->wb_scale_enable = 0;
 
 	if (!conn_state->writeback_job || !conn_state->writeback_job->fb)
 		return 0;
 
+
+	/* 0s are the default for writeback_dest_w,h - so don't scale.
+	 * The case where one of w,h is set but the other is 0 is meaningless
+	 * so ignore it
+	 */
+	if (conn_state->writeback_dest_w && conn_state->writeback_dest_h) {
+		if ((conn_state->writeback_dest_w != crtc_state->mode.hdisplay) ||
+		    (conn_state->writeback_dest_h != crtc_state->mode.vdisplay)) {
+			s->wb_scale_enable = 1;
+			mw_state->wb_scale_enable = true;
+		}
+	}
+
 	fb = conn_state->writeback_job->fb;
-	if ((fb->width != crtc_state->mode.hdisplay) ||
-	    (fb->height != crtc_state->mode.vdisplay)) {
-		DRM_DEBUG_KMS("Invalid framebuffer size %ux%u\n",
-				fb->width, fb->height);
-		return -EINVAL;
+	if (s->wb_scale_enable) {
+		if (s->scale_enable) {
+			DRM_DEBUG_KMS("Attempting to scale on writeback while scaling a layer\n");
+			return -EINVAL;
+		}
+
+		s->input_w = crtc_state->mode.hdisplay;
+		s->input_h = crtc_state->mode.vdisplay;
+		s->output_w = conn_state->writeback_dest_w;
+		s->output_h = conn_state->writeback_dest_h;
+
+		if (fb->width < s->output_w + conn_state->writeback_dest_x ||
+		    fb->height < s->output_h + conn_state->writeback_dest_y) {
+			DRM_DEBUG_KMS("Invalid framebuffer size %ux%u for writeback x,y,w,h %u,%u,%u,%u\n",
+					fb->width, fb->height,
+					conn_state->writeback_dest_x,
+					conn_state->writeback_dest_y,
+					s->output_w, s->output_h);
+			return -EINVAL;
+		}
+
+		if ((s->output_w > s->input_w) || (s->output_h > s->input_h)) {
+			DRM_DEBUG_KMS("Upscaling on writeback is not supported\n");
+			return -EINVAL;
+		}
+
+		/*
+		 * Convert crtc_[w|h] to U32.32, then divide by U16.16 src_[w|h]
+		 * to get the U16.16 result.
+		 */
+		h_upscale_factor = div_u64((u64)s->output_w << 32,
+					   (u32)s->input_w << 16);
+		v_upscale_factor = div_u64((u64)s->output_h << 32,
+					   (u32)s->input_h << 16);
+
+		/* enhancer is for upscaling */
+		s->enhancer_enable = 0;
+
+		malidp_set_se_config_phase(s);
+
+		s->hcoeff = malidp_se_select_coeffs(h_upscale_factor);
+		s->vcoeff = malidp_se_select_coeffs(v_upscale_factor);
+
+		drm_display_mode_to_videomode(&crtc_state->adjusted_mode, &vm);
+		ret = hwdev->hw->se_calc_mclk(hwdev, s, &vm);
+		if (ret < 0)
+			return -EINVAL;
+	}
+
+	else {
+		if ((fb->width < crtc_state->mode.hdisplay + conn_state->writeback_dest_x) ||
+		    (fb->height < crtc_state->mode.vdisplay + conn_state->writeback_dest_y)) {
+			DRM_DEBUG_KMS("Invalid framebuffer size %ux%u\n",
+					fb->width, fb->height);
+			return -EINVAL;
+	       }
 	}
 
 	if (fb->modifier) {
@@ -163,6 +224,8 @@ malidp_mw_encoder_atomic_check(struct drm_encoder *encoder,
 		struct drm_gem_cma_object *obj = drm_fb_cma_get_gem_obj(fb, i);
 		/* memory write buffers are never rotated */
 		u8 alignment = malidp_hw_get_pitch_align(malidp->dev, 0);
+		unsigned int cpp = fb->format->cpp[i];
+		unsigned int pitch = fb->pitches[i];
 
 		if (fb->pitches[i] & (alignment - 1)) {
 			DRM_DEBUG_KMS("Invalid pitch %u for plane %d\n",
@@ -170,7 +233,9 @@ malidp_mw_encoder_atomic_check(struct drm_encoder *encoder,
 			return -EINVAL;
 		}
 		mw_state->pitches[i] = fb->pitches[i];
-		mw_state->addrs[i] = obj->paddr + fb->offsets[i];
+		mw_state->addrs[i] = obj->paddr + fb->offsets[i] +
+				     (conn_state->writeback_dest_y * pitch) +
+				     (conn_state->writeback_dest_x * cpp);
 	}
 	mw_state->n_planes = n_planes;
 
@@ -257,13 +322,17 @@ void malidp_mw_atomic_commit(struct drm_device *drm,
 				     &mw_state->addrs[0],
 				     mw_state->format);
 
+		if (mw_state->wb_scale_enable) {
+			DRM_DEV_DEBUG_DRIVER(drm->dev,
+					     "Scaling writeback to %ux%u\n",
+					     conn_state->writeback_dest_w,
+					     conn_state->writeback_dest_h);
+		}
+
 		drm_writeback_queue_job(mw_conn, conn_state->writeback_job);
 		conn_state->writeback_job = NULL;
-		hwdev->hw->enable_memwrite(hwdev, mw_state->addrs,
-					   mw_state->pitches, mw_state->n_planes,
-					   fb->width, fb->height, mw_state->format,
-					   !mw_state->rgb2yuv_initialized ?
-					   mw_state->rgb2yuv_coeffs : NULL);
+		hwdev->hw->enable_memwrite(hwdev, conn_state->writeback_dest_w,
+					   conn_state->writeback_dest_h, mw_state);
 		mw_state->rgb2yuv_initialized = !!mw_state->rgb2yuv_coeffs;
 	} else {
 		DRM_DEV_DEBUG_DRIVER(drm->dev, "Disable memwrite\n");
diff --git a/drivers/gpu/drm/arm/malidp_regs.h b/drivers/gpu/drm/arm/malidp_regs.h
index a3363f3..254aa98 100644
--- a/drivers/gpu/drm/arm/malidp_regs.h
+++ b/drivers/gpu/drm/arm/malidp_regs.h
@@ -73,6 +73,7 @@
 #define   MALIDP_DISP_FUNC_CADJ		(1 << 4)
 #define   MALIDP_DISP_FUNC_ILACED	(1 << 8)
 #define   MALIDP_SCALE_ENGINE_EN	(1 << 16)
+#define   MALIDP_SE_MEMWRITE_SCL_EN	(1 << 5)
 #define   MALIDP_SE_MEMWRITE_EN		(2 << 5)
 
 /* register offsets for IRQ management */
-- 
2.7.4

Re: [PATCH v4 2/2] drm/malidp: Enable writeback scaling

[Liviu Dudau]

On Thu, May 02, 2019 at 05:10:10PM +0100, Ben Davis wrote:
> The phase setting part of malidp_crtc_atomic_check_scaling is refactored
> to allow use in writeback scaling.
> 
> Also the enable_memwrite function prototype is simplified by directly
> passing mw_state.
> 
> Signed-off-by: Ben Davis <ben.davis@arm.com>

Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>

I will pull this series the mali-dp tree after more people had a chance
to review it. I think the next thing to do would be to come up with a
test in igt for these properties.

Thanks,
Liviu

> ---
>  drivers/gpu/drm/arm/malidp_crtc.c |  47 ++++++++-------
>  drivers/gpu/drm/arm/malidp_drv.c  |  10 +++-
>  drivers/gpu/drm/arm/malidp_drv.h  |   2 +
>  drivers/gpu/drm/arm/malidp_hw.c   |  45 ++++++++++-----
>  drivers/gpu/drm/arm/malidp_hw.h   |  19 ++++++-
>  drivers/gpu/drm/arm/malidp_mw.c   | 117 ++++++++++++++++++++++++++++++--------
>  drivers/gpu/drm/arm/malidp_regs.h |   1 +
>  7 files changed, 176 insertions(+), 65 deletions(-)
> 
> diff --git a/drivers/gpu/drm/arm/malidp_crtc.c b/drivers/gpu/drm/arm/malidp_crtc.c
> index 3f65996..6548859 100644
> --- a/drivers/gpu/drm/arm/malidp_crtc.c
> +++ b/drivers/gpu/drm/arm/malidp_crtc.c
> @@ -265,6 +265,29 @@ static int malidp_crtc_atomic_check_ctm(struct drm_crtc *crtc,
>  	return 0;
>  }
>  
> +void malidp_set_se_config_phase(struct malidp_se_config *s)
> +{
> +#define SE_N_PHASE 4
> +#define SE_SHIFT_N_PHASE 12
> +	u32 phase;
> +
> +	/* Calculate initial_phase and delta_phase for horizontal. */
> +	phase = s->input_w;
> +	s->h_init_phase = ((phase << SE_N_PHASE) / s->output_w + 1) / 2;
> +
> +	phase <<= (SE_SHIFT_N_PHASE + SE_N_PHASE);
> +	s->h_delta_phase = phase / s->output_w;
> +
> +	/* Same for vertical. */
> +	phase = s->input_h;
> +	s->v_init_phase = ((phase << SE_N_PHASE) / s->output_h + 1) / 2;
> +
> +	phase <<= (SE_SHIFT_N_PHASE + SE_N_PHASE);
> +	s->v_delta_phase = phase / s->output_h;
> +#undef SE_N_PHASE
> +#undef SE_SHIFT_N_PHASE
> +}
> +
>  static int malidp_crtc_atomic_check_scaling(struct drm_crtc *crtc,
>  					    struct drm_crtc_state *state)
>  {
> @@ -291,7 +314,6 @@ static int malidp_crtc_atomic_check_scaling(struct drm_crtc *crtc,
>  
>  	drm_atomic_crtc_state_for_each_plane_state(plane, pstate, state) {
>  		struct malidp_plane *mp = to_malidp_plane(plane);
> -		u32 phase;
>  
>  		if (!(mp->layer->id & scaling))
>  			continue;
> @@ -319,27 +341,8 @@ static int malidp_crtc_atomic_check_scaling(struct drm_crtc *crtc,
>  		s->output_w = pstate->crtc_w;
>  		s->output_h = pstate->crtc_h;
>  
> -#define SE_N_PHASE 4
> -#define SE_SHIFT_N_PHASE 12
> -		/* Calculate initial_phase and delta_phase for horizontal. */
> -		phase = s->input_w;
> -		s->h_init_phase =
> -				((phase << SE_N_PHASE) / s->output_w + 1) / 2;
> -
> -		phase = s->input_w;
> -		phase <<= (SE_SHIFT_N_PHASE + SE_N_PHASE);
> -		s->h_delta_phase = phase / s->output_w;
> -
> -		/* Same for vertical. */
> -		phase = s->input_h;
> -		s->v_init_phase =
> -				((phase << SE_N_PHASE) / s->output_h + 1) / 2;
> -
> -		phase = s->input_h;
> -		phase <<= (SE_SHIFT_N_PHASE + SE_N_PHASE);
> -		s->v_delta_phase = phase / s->output_h;
> -#undef SE_N_PHASE
> -#undef SE_SHIFT_N_PHASE
> +
> +		malidp_set_se_config_phase(s);
>  		s->plane_src_id = mp->layer->id;
>  	}
>  
> diff --git a/drivers/gpu/drm/arm/malidp_drv.c b/drivers/gpu/drm/arm/malidp_drv.c
> index d37ff9d..e2465e9 100644
> --- a/drivers/gpu/drm/arm/malidp_drv.c
> +++ b/drivers/gpu/drm/arm/malidp_drv.c
> @@ -138,7 +138,7 @@ static void malidp_atomic_commit_se_config(struct drm_crtc *crtc,
>  	u32 val;
>  
>  	/* Set SE_CONTROL */
> -	if (!s->scale_enable) {
> +	if (!s->scale_enable && !s->wb_scale_enable) {
>  		val = malidp_hw_read(hwdev, se_control);
>  		val &= ~MALIDP_SE_SCALING_EN;
>  		malidp_hw_write(hwdev, val, se_control);
> @@ -147,12 +147,16 @@ static void malidp_atomic_commit_se_config(struct drm_crtc *crtc,
>  
>  	hwdev->hw->se_set_scaling_coeffs(hwdev, s, old_s);
>  	val = malidp_hw_read(hwdev, se_control);
> -	val |= MALIDP_SE_SCALING_EN | MALIDP_SE_ALPHA_EN;
> +	val |= MALIDP_SE_SCALING_EN;
>  
>  	val &= ~MALIDP_SE_ENH(MALIDP_SE_ENH_MASK);
>  	val |= s->enhancer_enable ? MALIDP_SE_ENH(3) : 0;
>  
> -	val |= MALIDP_SE_RGBO_IF_EN;
> +	if (s->scale_enable)
> +		val |= (MALIDP_SE_RGBO_IF_EN | MALIDP_SE_ALPHA_EN);
> +	else
> +		val &= ~((MALIDP_SE_RGBO_IF_EN | MALIDP_SE_ALPHA_EN));
> +
>  	malidp_hw_write(hwdev, val, se_control);
>  
>  	/* Set IN_SIZE & OUT_SIZE. */
> diff --git a/drivers/gpu/drm/arm/malidp_drv.h b/drivers/gpu/drm/arm/malidp_drv.h
> index 391d6ff..924f831 100644
> --- a/drivers/gpu/drm/arm/malidp_drv.h
> +++ b/drivers/gpu/drm/arm/malidp_drv.h
> @@ -104,6 +104,8 @@ struct malidp_crtc_state {
>  int malidp_de_planes_init(struct drm_device *drm);
>  int malidp_crtc_init(struct drm_device *drm);
>  
> +void malidp_set_se_config_phase(struct malidp_se_config *s);
> +
>  bool malidp_hw_format_is_linear_only(u32 format);
>  bool malidp_hw_format_is_afbc_only(u32 format);
>  
> diff --git a/drivers/gpu/drm/arm/malidp_hw.c b/drivers/gpu/drm/arm/malidp_hw.c
> index 1a36718..6f59c0e 100644
> --- a/drivers/gpu/drm/arm/malidp_hw.c
> +++ b/drivers/gpu/drm/arm/malidp_hw.c
> @@ -497,13 +497,18 @@ static long malidp500_se_calc_mclk(struct malidp_hw_device *hwdev,
>  	return ret;
>  }
>  
> -static int malidp500_enable_memwrite(struct malidp_hw_device *hwdev,
> -				     dma_addr_t *addrs, s32 *pitches,
> -				     int num_planes, u16 w, u16 h, u32 fmt_id,
> -				     const s16 *rgb2yuv_coeffs)
> +static int malidp500_enable_memwrite(struct malidp_hw_device *hwdev, u16 w, u16 h,
> +				     struct malidp_mw_connector_state *mw_state)
>  {
> +
> +	int num_planes = mw_state->n_planes;
> +	dma_addr_t *addrs = mw_state->addrs;
> +	s32 *pitches = mw_state->pitches;
> +	u32 fmt_id = mw_state->format;
>  	u32 base = MALIDP500_SE_MEMWRITE_BASE;
>  	u32 de_base = malidp_get_block_base(hwdev, MALIDP_DE_BLOCK);
> +	const s16 *rgb2yuv_coeffs = !mw_state->rgb2yuv_initialized ?
> +					mw_state->rgb2yuv_coeffs : NULL;
>  
>  	/* enable the scaling engine block */
>  	malidp_hw_setbits(hwdev, MALIDP_SCALE_ENGINE_EN, de_base + MALIDP_DE_DISPLAY_FUNC);
> @@ -847,13 +852,18 @@ static long malidp550_se_calc_mclk(struct malidp_hw_device *hwdev,
>  	return ret;
>  }
>  
> -static int malidp550_enable_memwrite(struct malidp_hw_device *hwdev,
> -				     dma_addr_t *addrs, s32 *pitches,
> -				     int num_planes, u16 w, u16 h, u32 fmt_id,
> -				     const s16 *rgb2yuv_coeffs)
> +static int malidp550_enable_memwrite(struct malidp_hw_device *hwdev, u16 w, u16 h,
> +				     struct malidp_mw_connector_state *mw_state)
>  {
> +	int num_planes = mw_state->n_planes;
> +	bool scaling = mw_state->wb_scale_enable;
> +	dma_addr_t *addrs = mw_state->addrs;
> +	s32 *pitches = mw_state->pitches;
> +	u32 fmt_id = mw_state->format;
>  	u32 base = MALIDP550_SE_MEMWRITE_BASE;
>  	u32 de_base = malidp_get_block_base(hwdev, MALIDP_DE_BLOCK);
> +	const s16 *rgb2yuv_coeffs = !mw_state->rgb2yuv_initialized ?
> +					mw_state->rgb2yuv_coeffs : NULL;
>  
>  	/* enable the scaling engine block */
>  	malidp_hw_setbits(hwdev, MALIDP_SCALE_ENGINE_EN, de_base + MALIDP_DE_DISPLAY_FUNC);
> @@ -876,10 +886,18 @@ static int malidp550_enable_memwrite(struct malidp_hw_device *hwdev,
>  		WARN(1, "Invalid number of planes");
>  	}
>  
> -	malidp_hw_write(hwdev, MALIDP_DE_H_ACTIVE(w) | MALIDP_DE_V_ACTIVE(h),
> -			MALIDP550_SE_MEMWRITE_OUT_SIZE);
> -	malidp_hw_setbits(hwdev, MALIDP550_SE_MEMWRITE_ONESHOT | MALIDP_SE_MEMWRITE_EN,
> -			  MALIDP550_SE_CONTROL);
> +	malidp_hw_clearbits(hwdev, MALIDP_SE_MEMWRITE_EN | MALIDP_SE_MEMWRITE_SCL_EN,
> +			    MALIDP550_SE_CONTROL);
> +
> +	if (scaling) {
> +		malidp_hw_setbits(hwdev, MALIDP550_SE_MEMWRITE_ONESHOT | MALIDP_SE_MEMWRITE_SCL_EN,
> +				  MALIDP550_SE_CONTROL);
> +	} else {
> +		malidp_hw_write(hwdev, MALIDP_DE_H_ACTIVE(w) | MALIDP_DE_V_ACTIVE(h),
> +				MALIDP550_SE_MEMWRITE_OUT_SIZE);
> +		malidp_hw_setbits(hwdev, MALIDP550_SE_MEMWRITE_ONESHOT | MALIDP_SE_MEMWRITE_EN,
> +				  MALIDP550_SE_CONTROL);
> +	}
>  
>  	if (rgb2yuv_coeffs) {
>  		int i;
> @@ -897,7 +915,8 @@ static void malidp550_disable_memwrite(struct malidp_hw_device *hwdev)
>  {
>  	u32 base = malidp_get_block_base(hwdev, MALIDP_DE_BLOCK);
>  
> -	malidp_hw_clearbits(hwdev, MALIDP550_SE_MEMWRITE_ONESHOT | MALIDP_SE_MEMWRITE_EN,
> +	malidp_hw_clearbits(hwdev,
> +			    MALIDP550_SE_MEMWRITE_ONESHOT | MALIDP_SE_MEMWRITE_EN | MALIDP_SE_MEMWRITE_SCL_EN,
>  			    MALIDP550_SE_CONTROL);
>  	malidp_hw_clearbits(hwdev, MALIDP_SCALE_ENGINE_EN, base + MALIDP_DE_DISPLAY_FUNC);
>  }
> diff --git a/drivers/gpu/drm/arm/malidp_hw.h b/drivers/gpu/drm/arm/malidp_hw.h
> index 8352a2e..61ddcb5 100644
> --- a/drivers/gpu/drm/arm/malidp_hw.h
> +++ b/drivers/gpu/drm/arm/malidp_hw.h
> @@ -85,6 +85,7 @@ enum malidp_scaling_coeff_set {
>  struct malidp_se_config {
>  	u8 scale_enable : 1;
>  	u8 enhancer_enable : 1;
> +	u8 wb_scale_enable : 1;
>  	u8 hcoeff : 3;
>  	u8 vcoeff : 3;
>  	u8 plane_src_id;
> @@ -94,6 +95,19 @@ struct malidp_se_config {
>  	u32 v_init_phase, v_delta_phase;
>  };
>  
> +#define to_mw_state(_state) (struct malidp_mw_connector_state *)(_state)
> +
> +struct malidp_mw_connector_state {
> +	struct drm_connector_state base;
> +	dma_addr_t addrs[2];
> +	s32 pitches[2];
> +	u8 format;
> +	u8 n_planes;
> +	bool rgb2yuv_initialized;
> +	const s16 *rgb2yuv_coeffs;
> +	bool wb_scale_enable;
> +};
> +
>  /* regmap features */
>  #define MALIDP_REGMAP_HAS_CLEARIRQ				BIT(0)
>  #define MALIDP_DEVICE_AFBC_SUPPORT_SPLIT			BIT(1)
> @@ -206,9 +220,8 @@ struct malidp_hw {
>  	 * @param h - height of the output frame
>  	 * @param fmt_id - internal format ID of output buffer
>  	 */
> -	int (*enable_memwrite)(struct malidp_hw_device *hwdev, dma_addr_t *addrs,
> -			       s32 *pitches, int num_planes, u16 w, u16 h, u32 fmt_id,
> -			       const s16 *rgb2yuv_coeffs);
> +	int (*enable_memwrite)(struct malidp_hw_device *hwdev, u16 w, u16 h,
> +			       struct malidp_mw_connector_state *mw_state);
>  
>  	/*
>  	 * Disable the writing to memory of the next frame's content.
> diff --git a/drivers/gpu/drm/arm/malidp_mw.c b/drivers/gpu/drm/arm/malidp_mw.c
> index 2865f7a..f1ad588 100644
> --- a/drivers/gpu/drm/arm/malidp_mw.c
> +++ b/drivers/gpu/drm/arm/malidp_mw.c
> @@ -13,23 +13,12 @@
>  #include <drm/drm_gem_cma_helper.h>
>  #include <drm/drmP.h>
>  #include <drm/drm_writeback.h>
> +#include <video/videomode.h>
>  
>  #include "malidp_drv.h"
>  #include "malidp_hw.h"
>  #include "malidp_mw.h"
>  
> -#define to_mw_state(_state) (struct malidp_mw_connector_state *)(_state)
> -
> -struct malidp_mw_connector_state {
> -	struct drm_connector_state base;
> -	dma_addr_t addrs[2];
> -	s32 pitches[2];
> -	u8 format;
> -	u8 n_planes;
> -	bool rgb2yuv_initialized;
> -	const s16 *rgb2yuv_coeffs;
> -};
> -
>  static int malidp_mw_connector_get_modes(struct drm_connector *connector)
>  {
>  	struct drm_device *dev = connector->dev;
> @@ -126,19 +115,91 @@ malidp_mw_encoder_atomic_check(struct drm_encoder *encoder,
>  			       struct drm_connector_state *conn_state)
>  {
>  	struct malidp_mw_connector_state *mw_state = to_mw_state(conn_state);
> +	struct malidp_crtc_state *cs = to_malidp_crtc_state(crtc_state);
> +	struct malidp_se_config *s = &cs->scaler_config;
>  	struct malidp_drm *malidp = encoder->dev->dev_private;
>  	struct drm_framebuffer *fb;
> -	int i, n_planes;
> +	int i, n_planes, ret;
> +	struct malidp_hw_device *hwdev = malidp->dev;
> +	struct videomode vm;
> +	u32 h_upscale_factor = 0; /* U16.16 */
> +	u32 v_upscale_factor = 0; /* U16.16 */
> +
> +	s->wb_scale_enable = 0;
>  
>  	if (!conn_state->writeback_job || !conn_state->writeback_job->fb)
>  		return 0;
>  
> +
> +	/* 0s are the default for writeback_dest_w,h - so don't scale.
> +	 * The case where one of w,h is set but the other is 0 is meaningless
> +	 * so ignore it
> +	 */
> +	if (conn_state->writeback_dest_w && conn_state->writeback_dest_h) {
> +		if ((conn_state->writeback_dest_w != crtc_state->mode.hdisplay) ||
> +		    (conn_state->writeback_dest_h != crtc_state->mode.vdisplay)) {
> +			s->wb_scale_enable = 1;
> +			mw_state->wb_scale_enable = true;
> +		}
> +	}
> +
>  	fb = conn_state->writeback_job->fb;
> -	if ((fb->width != crtc_state->mode.hdisplay) ||
> -	    (fb->height != crtc_state->mode.vdisplay)) {
> -		DRM_DEBUG_KMS("Invalid framebuffer size %ux%u\n",
> -				fb->width, fb->height);
> -		return -EINVAL;
> +	if (s->wb_scale_enable) {
> +		if (s->scale_enable) {
> +			DRM_DEBUG_KMS("Attempting to scale on writeback while scaling a layer\n");
> +			return -EINVAL;
> +		}
> +
> +		s->input_w = crtc_state->mode.hdisplay;
> +		s->input_h = crtc_state->mode.vdisplay;
> +		s->output_w = conn_state->writeback_dest_w;
> +		s->output_h = conn_state->writeback_dest_h;
> +
> +		if (fb->width < s->output_w + conn_state->writeback_dest_x ||
> +		    fb->height < s->output_h + conn_state->writeback_dest_y) {
> +			DRM_DEBUG_KMS("Invalid framebuffer size %ux%u for writeback x,y,w,h %u,%u,%u,%u\n",
> +					fb->width, fb->height,
> +					conn_state->writeback_dest_x,
> +					conn_state->writeback_dest_y,
> +					s->output_w, s->output_h);
> +			return -EINVAL;
> +		}
> +
> +		if ((s->output_w > s->input_w) || (s->output_h > s->input_h)) {
> +			DRM_DEBUG_KMS("Upscaling on writeback is not supported\n");
> +			return -EINVAL;
> +		}
> +
> +		/*
> +		 * Convert crtc_[w|h] to U32.32, then divide by U16.16 src_[w|h]
> +		 * to get the U16.16 result.
> +		 */
> +		h_upscale_factor = div_u64((u64)s->output_w << 32,
> +					   (u32)s->input_w << 16);
> +		v_upscale_factor = div_u64((u64)s->output_h << 32,
> +					   (u32)s->input_h << 16);
> +
> +		/* enhancer is for upscaling */
> +		s->enhancer_enable = 0;
> +
> +		malidp_set_se_config_phase(s);
> +
> +		s->hcoeff = malidp_se_select_coeffs(h_upscale_factor);
> +		s->vcoeff = malidp_se_select_coeffs(v_upscale_factor);
> +
> +		drm_display_mode_to_videomode(&crtc_state->adjusted_mode, &vm);
> +		ret = hwdev->hw->se_calc_mclk(hwdev, s, &vm);
> +		if (ret < 0)
> +			return -EINVAL;
> +	}
> +
> +	else {
> +		if ((fb->width < crtc_state->mode.hdisplay + conn_state->writeback_dest_x) ||
> +		    (fb->height < crtc_state->mode.vdisplay + conn_state->writeback_dest_y)) {
> +			DRM_DEBUG_KMS("Invalid framebuffer size %ux%u\n",
> +					fb->width, fb->height);
> +			return -EINVAL;
> +	       }
>  	}
>  
>  	if (fb->modifier) {
> @@ -163,6 +224,8 @@ malidp_mw_encoder_atomic_check(struct drm_encoder *encoder,
>  		struct drm_gem_cma_object *obj = drm_fb_cma_get_gem_obj(fb, i);
>  		/* memory write buffers are never rotated */
>  		u8 alignment = malidp_hw_get_pitch_align(malidp->dev, 0);
> +		unsigned int cpp = fb->format->cpp[i];
> +		unsigned int pitch = fb->pitches[i];
>  
>  		if (fb->pitches[i] & (alignment - 1)) {
>  			DRM_DEBUG_KMS("Invalid pitch %u for plane %d\n",
> @@ -170,7 +233,9 @@ malidp_mw_encoder_atomic_check(struct drm_encoder *encoder,
>  			return -EINVAL;
>  		}
>  		mw_state->pitches[i] = fb->pitches[i];
> -		mw_state->addrs[i] = obj->paddr + fb->offsets[i];
> +		mw_state->addrs[i] = obj->paddr + fb->offsets[i] +
> +				     (conn_state->writeback_dest_y * pitch) +
> +				     (conn_state->writeback_dest_x * cpp);
>  	}
>  	mw_state->n_planes = n_planes;
>  
> @@ -257,13 +322,17 @@ void malidp_mw_atomic_commit(struct drm_device *drm,
>  				     &mw_state->addrs[0],
>  				     mw_state->format);
>  
> +		if (mw_state->wb_scale_enable) {
> +			DRM_DEV_DEBUG_DRIVER(drm->dev,
> +					     "Scaling writeback to %ux%u\n",
> +					     conn_state->writeback_dest_w,
> +					     conn_state->writeback_dest_h);
> +		}
> +
>  		drm_writeback_queue_job(mw_conn, conn_state->writeback_job);
>  		conn_state->writeback_job = NULL;
> -		hwdev->hw->enable_memwrite(hwdev, mw_state->addrs,
> -					   mw_state->pitches, mw_state->n_planes,
> -					   fb->width, fb->height, mw_state->format,
> -					   !mw_state->rgb2yuv_initialized ?
> -					   mw_state->rgb2yuv_coeffs : NULL);
> +		hwdev->hw->enable_memwrite(hwdev, conn_state->writeback_dest_w,
> +					   conn_state->writeback_dest_h, mw_state);
>  		mw_state->rgb2yuv_initialized = !!mw_state->rgb2yuv_coeffs;
>  	} else {
>  		DRM_DEV_DEBUG_DRIVER(drm->dev, "Disable memwrite\n");
> diff --git a/drivers/gpu/drm/arm/malidp_regs.h b/drivers/gpu/drm/arm/malidp_regs.h
> index a3363f3..254aa98 100644
> --- a/drivers/gpu/drm/arm/malidp_regs.h
> +++ b/drivers/gpu/drm/arm/malidp_regs.h
> @@ -73,6 +73,7 @@
>  #define   MALIDP_DISP_FUNC_CADJ		(1 << 4)
>  #define   MALIDP_DISP_FUNC_ILACED	(1 << 8)
>  #define   MALIDP_SCALE_ENGINE_EN	(1 << 16)
> +#define   MALIDP_SE_MEMWRITE_SCL_EN	(1 << 5)
>  #define   MALIDP_SE_MEMWRITE_EN		(2 << 5)
>  
>  /* register offsets for IRQ management */
> -- 
> 2.7.4
> 

-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
  ---------------
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