drm/i915/skl+: calculate pixel_rate & relative_data_rate in fixed point

This patch make changes to calculate adjusted plane pixel rate &
plane downscale amount using fixed_point functions available.
This patch will give uniformity in code, & will help to avoid mixing of
32bit uint32_t variable for fixed-16.16 with fixed_16_16_t variables in
later patch in the series.

Changes from V1:
 - Rebase based on wrapper name change
 - Remove unnecessary comment

Signed-off-by: Mahesh Kumar <mahesh1.kumar@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170517115831.13830-5-mahesh1.kumar@intel.com

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 8ff8cc59dccaccf0afb283bf5826341a8664ad2f..ab056952cfa475921e87abdc110801cf4d1fdf9e 100644 (file)
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3827,26 +3827,27 @@ void skl_ddb_get_hw_state(struct drm_i915_private *dev_priv,
  * Return value is provided in 16.16 fixed point form to retain fractional part.
  * Caller should take care of dividing & rounding off the value.
  */
-static uint32_t
+static uint_fixed_16_16_t
 skl_plane_downscale_amount(const struct intel_crtc_state *cstate,
                           const struct intel_plane_state *pstate)
 {
        struct intel_plane *plane = to_intel_plane(pstate->base.plane);
-       uint32_t downscale_h, downscale_w;
        uint32_t src_w, src_h, dst_w, dst_h;
+       uint_fixed_16_16_t fp_w_ratio, fp_h_ratio;
+       uint_fixed_16_16_t downscale_h, downscale_w;
 
        if (WARN_ON(!intel_wm_plane_visible(cstate, pstate)))
-               return DRM_PLANE_HELPER_NO_SCALING;
+               return u32_to_fixed_16_16(0);
 
        /* n.b., src is 16.16 fixed point, dst is whole integer */
        if (plane->id == PLANE_CURSOR) {
-               src_w = pstate->base.src_w;
-               src_h = pstate->base.src_h;
+               src_w = pstate->base.src_w >> 16;
+               src_h = pstate->base.src_h >> 16;
                dst_w = pstate->base.crtc_w;
                dst_h = pstate->base.crtc_h;
        } else {
-               src_w = drm_rect_width(&pstate->base.src);
-               src_h = drm_rect_height(&pstate->base.src);
+               src_w = drm_rect_width(&pstate->base.src) >> 16;
+               src_h = drm_rect_height(&pstate->base.src) >> 16;
                dst_w = drm_rect_width(&pstate->base.dst);
                dst_h = drm_rect_height(&pstate->base.dst);
        }
@@ -3854,11 +3855,12 @@ skl_plane_downscale_amount(const struct intel_crtc_state *cstate,
        if (drm_rotation_90_or_270(pstate->base.rotation))
                swap(dst_w, dst_h);
 
-       downscale_h = max(src_h / dst_h, (uint32_t)DRM_PLANE_HELPER_NO_SCALING);
-       downscale_w = max(src_w / dst_w, (uint32_t)DRM_PLANE_HELPER_NO_SCALING);
+       fp_w_ratio = fixed_16_16_div(src_w, dst_w);
+       fp_h_ratio = fixed_16_16_div(src_h, dst_h);
+       downscale_w = max_fixed_16_16(fp_w_ratio, u32_to_fixed_16_16(1));
+       downscale_h = max_fixed_16_16(fp_h_ratio, u32_to_fixed_16_16(1));
 
-       /* Provide result in 16.16 fixed point */
-       return (uint64_t)downscale_w * downscale_h >> 16;
+       return mul_fixed16(downscale_w, downscale_h);
 }
 
 static unsigned int
@@ -3868,10 +3870,11 @@ skl_plane_relative_data_rate(const struct intel_crtc_state *cstate,
 {
        struct intel_plane *plane = to_intel_plane(pstate->plane);
        struct intel_plane_state *intel_pstate = to_intel_plane_state(pstate);
-       uint32_t down_scale_amount, data_rate;
+       uint32_t data_rate;
        uint32_t width = 0, height = 0;
        struct drm_framebuffer *fb;
        u32 format;
+       uint_fixed_16_16_t down_scale_amount;
 
        if (!intel_pstate->base.visible)
                return 0;
@@ -3905,7 +3908,7 @@ skl_plane_relative_data_rate(const struct intel_crtc_state *cstate,
 
        down_scale_amount = skl_plane_downscale_amount(cstate, intel_pstate);
 
-       return (uint64_t)data_rate * down_scale_amount >> 16;
+       return mul_round_up_u32_fixed16(data_rate, down_scale_amount);
 }
 
 /*
@@ -4191,8 +4194,7 @@ static uint32_t skl_adjusted_plane_pixel_rate(const struct intel_crtc_state *cst
                                              struct intel_plane_state *pstate)
 {
        uint64_t adjusted_pixel_rate;
-       uint64_t downscale_amount;
-       uint64_t pixel_rate;
+       uint_fixed_16_16_t downscale_amount;
 
        /* Shouldn't reach here on disabled planes... */
        if (WARN_ON(!intel_wm_plane_visible(cstate, pstate)))
@@ -4205,10 +4207,8 @@ static uint32_t skl_adjusted_plane_pixel_rate(const struct intel_crtc_state *cst
        adjusted_pixel_rate = cstate->pixel_rate;
        downscale_amount = skl_plane_downscale_amount(cstate, pstate);
 
-       pixel_rate = adjusted_pixel_rate * downscale_amount >> 16;
-       WARN_ON(pixel_rate != clamp_t(uint32_t, pixel_rate, 0, ~0));
-
-       return pixel_rate;
+       return mul_round_up_u32_fixed16(adjusted_pixel_rate,
+                                           downscale_amount);
 }
 
 static int skl_compute_plane_wm(const struct drm_i915_private *dev_priv,