Commit ac69c01f authored by Dom Cobley's avatar Dom Cobley Committed by Dave Stevenson
Browse files

drm/vc4: plane: Handle fractional coordinates using the phase field 



Apply fractional source co-ordinates into the scaling filters.

Signed-off-by: default avatarDom Cobley <popcornmix@gmail.com>
Reviewed-by: default avatarMaxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240621152055.4180873-3-dave.stevenson@raspberrypi.com


Signed-off-by: default avatarDave Stevenson <dave.stevenson@raspberrypi.com>
parent 6639d7d9

drivers/gpu/drm/vc4/vc4_plane.c

+76 −11
Original line number Diff line number Diff line
@@ -532,14 +532,61 @@ static void vc4_write_tpz(struct vc4_plane_state *vc4_state, u32 src, u32 dst) 
			VC4_SET_FIELD(recip, SCALER_TPZ1_RECIP));

}



static void vc4_write_ppf(struct vc4_plane_state *vc4_state, u32 src, u32 dst)

/* phase magnitude bits */

#define PHASE_BITS 6



static void vc4_write_ppf(struct vc4_plane_state *vc4_state, u32 src, u32 dst,

			  u32 xy, int channel)

{

	u32 scale = (1 << 16) * src / dst;

	u32 scale = src / dst;

	s32 offset, offset2;

	s32 phase;



	/*

	 * Start the phase at 1/2 pixel from the 1st pixel at src_x.

	 * 1/4 pixel for YUV.

	 */

	if (channel) {

		/*

		 * The phase is relative to scale_src->x, so shift it for

		 * display list's x value

		 */

		offset = (xy & 0x1ffff) >> (16 - PHASE_BITS) >> 1;

		offset += -(1 << PHASE_BITS >> 2);

	} else {

		/*

		 * The phase is relative to scale_src->x, so shift it for

		 * display list's x value

		 */

		offset = (xy & 0xffff) >> (16 - PHASE_BITS);

		offset += -(1 << PHASE_BITS >> 1);



		/*

		 * This is a kludge to make sure the scaling factors are

		 * consistent with YUV's luma scaling. We lose 1-bit precision

		 * because of this.

		 */

		scale &= ~1;

	}



	/*

	 * There may be a also small error introduced by precision of scale.

	 * Add half of that as a compromise

	 */

	offset2 = src - dst * scale;

	offset2 >>= 16 - PHASE_BITS;

	phase = offset + (offset2 >> 1);



	/* Ensure +ve values don't touch the sign bit, then truncate negative values */

	if (phase >= 1 << PHASE_BITS)

		phase = (1 << PHASE_BITS) - 1;



	phase &= SCALER_PPF_IPHASE_MASK;



	vc4_dlist_write(vc4_state,

			SCALER_PPF_AGC |

			VC4_SET_FIELD(scale, SCALER_PPF_SCALE) |

			VC4_SET_FIELD(0, SCALER_PPF_IPHASE));

			VC4_SET_FIELD(phase, SCALER_PPF_IPHASE));

}



static u32 vc4_lbm_size(struct drm_plane_state *state)
@@ -597,27 +644,27 @@ static void vc4_write_scaling_parameters(struct drm_plane_state *state, 


	/* Ch0 H-PPF Word 0: Scaling Parameters */

	if (vc4_state->x_scaling[channel] == VC4_SCALING_PPF) {

		vc4_write_ppf(vc4_state,

			      vc4_state->src_w[channel], vc4_state->crtc_w);

		vc4_write_ppf(vc4_state, vc4_state->src_w[channel],

			      vc4_state->crtc_w, vc4_state->src_x, channel);

	}



	/* Ch0 V-PPF Words 0-1: Scaling Parameters, Context */

	if (vc4_state->y_scaling[channel] == VC4_SCALING_PPF) {

		vc4_write_ppf(vc4_state,

			      vc4_state->src_h[channel], vc4_state->crtc_h);

		vc4_write_ppf(vc4_state, vc4_state->src_h[channel],

			      vc4_state->crtc_h, vc4_state->src_y, channel);

		vc4_dlist_write(vc4_state, 0xc0c0c0c0);

	}



	/* Ch0 H-TPZ Words 0-1: Scaling Parameters, Recip */

	if (vc4_state->x_scaling[channel] == VC4_SCALING_TPZ) {

		vc4_write_tpz(vc4_state,

			      vc4_state->src_w[channel], vc4_state->crtc_w);

		vc4_write_tpz(vc4_state, vc4_state->src_w[channel],

			      vc4_state->crtc_w);

	}



	/* Ch0 V-TPZ Words 0-2: Scaling Parameters, Recip, Context */

	if (vc4_state->y_scaling[channel] == VC4_SCALING_TPZ) {

		vc4_write_tpz(vc4_state,

			      vc4_state->src_h[channel], vc4_state->crtc_h);

		vc4_write_tpz(vc4_state, vc4_state->src_h[channel],

			      vc4_state->crtc_h);

		vc4_dlist_write(vc4_state, 0xc0c0c0c0);

	}

}
@@ -1052,6 +1099,24 @@ static int vc4_plane_mode_set(struct drm_plane *plane, 
		return -EINVAL;

	}



	/* fetch an extra pixel if we don't actually line up with the left edge. */

	if ((vc4_state->src_x & 0xffff) && vc4_state->src_x < (state->fb->width << 16))

		width++;



	/* same for the right side */

	if (((vc4_state->src_x + vc4_state->src_w[0]) & 0xffff) &&

	    vc4_state->src_x + vc4_state->src_w[0] < (state->fb->width << 16))

		width++;



	/* now for the top */

	if ((vc4_state->src_y & 0xffff) && vc4_state->src_y < (state->fb->height << 16))

		height++;



	/* and the bottom */

	if (((vc4_state->src_y + vc4_state->src_h[0]) & 0xffff) &&

	    vc4_state->src_y + vc4_state->src_h[0] < (state->fb->height << 16))

		height++;



	/* Don't waste cycles mixing with plane alpha if the set alpha

	 * is opaque or there is no per-pixel alpha information.

	 * In any case we use the alpha property value as the fixed alpha.