From 1f344e8eb017093573ddccd939b2dc5d930569dc Mon Sep 17 00:00:00 2001 From: Dom Cobley Date: Fri, 9 Apr 2021 15:00:40 +0100 Subject: [PATCH] vc4/drm: Handle fractional coordinates using the phase field Signed-off-by: Dom Cobley --- drivers/gpu/drm/vc4/vc4_plane.c | 61 ++++++++++++++++++++++++++++++--- 1 file changed, 56 insertions(+), 5 deletions(-) --- a/drivers/gpu/drm/vc4/vc4_plane.c +++ b/drivers/gpu/drm/vc4/vc4_plane.c @@ -464,14 +464,47 @@ static void vc4_write_tpz(struct vc4_pla 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 consitent with YUV's luma scaling. + we lose 1bit 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) @@ -530,13 +563,13 @@ static void vc4_write_scaling_parameters /* 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_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_state->src_h[channel], vc4_state->crtc_h, vc4_state->src_y, channel); vc4_dlist_write(vc4_state, 0xc0c0c0c0); } @@ -984,6 +1017,24 @@ static int vc4_plane_mode_set(struct drm 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.