| Message ID | 20200319102103.28895-5-pankaj.laxminarayan.bharadiya@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Introduce drm scaling filter property | expand |
On Thu, Mar 19, 2020 at 03:51:02PM +0530, Pankaj Bharadiya wrote: > Integer scaling (IS) is a nearest-neighbor upscaling technique that > simply scales up the existing pixels by an integer > (i.e., whole number) multiplier.Nearest-neighbor (NN) interpolation > works by filling in the missing color values in the upscaled image > with that of the coordinate-mapped nearest source pixel value. > > Both IS and NN preserve the clarity of the original image. Integer > scaling is particularly useful for pixel art games that rely on > sharp, blocky images to deliver their distinctive look. > > Introduce skl_scaler_setup_nearest_neighbor_filter() function which > configures the scaler filter coefficients to enable nearest-neighbor > filtering. > > Bspec: 49247 > > changes since v1: > * Rearrange skl_scaler_setup_nearest_neighbor_filter() to iterate the > registers directly instead of the phases and taps (Ville) > > changes since RFC: > * Refine the skl_scaler_setup_nearest_neighbor_filter() logic (Ville) > > Signed-off-by: Shashank Sharma <shashank.sharma@intel.com> > Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com> > Signed-off-by: Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com> > --- > drivers/gpu/drm/i915/display/intel_display.c | 72 ++++++++++++++++++++ > drivers/gpu/drm/i915/display/intel_display.h | 2 + > 2 files changed, 74 insertions(+) > > diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c > index 8f23c4d51c33..791dd908aa89 100644 > --- a/drivers/gpu/drm/i915/display/intel_display.c > +++ b/drivers/gpu/drm/i915/display/intel_display.c > @@ -6237,6 +6237,78 @@ void skl_scaler_disable(const struct intel_crtc_state *old_crtc_state) > skl_detach_scaler(crtc, i); > } > > +static int skl_coef_tap(int i) > +{ > + return i % 7; > +} > + > +static u16 skl_nearest_filter_coef(int t) > +{ > + return t == 3 ? 0x0800 : 0x3000; > +} > + > +/** > + * Theory behind setting nearest-neighbor integer scaling: > + * > + * 17 phase of 7 taps requires 119 coefficients in 60 dwords per set. > + * The letter represents the filter tap (D is the center tap) and the number > + * represents the coefficient set for a phase (0-16). > + * > + * +------------+------------------------+------------------------+ > + * |Index value | Data value coeffient 1 | Data value coeffient 2 | > + * +------------+------------------------+------------------------+ > + * | 00h | B0 | A0 | > + * +------------+------------------------+------------------------+ > + * | 01h | D0 | C0 | > + * +------------+------------------------+------------------------+ > + * | 02h | F0 | E0 | > + * +------------+------------------------+------------------------+ > + * | 03h | A1 | G0 | > + * +------------+------------------------+------------------------+ > + * | 04h | C1 | B1 | > + * +------------+------------------------+------------------------+ > + * | ... | ... | ... | > + * +------------+------------------------+------------------------+ > + * | 38h | B16 | A16 | > + * +------------+------------------------+------------------------+ > + * | 39h | D16 | C16 | > + * +------------+------------------------+------------------------+ > + * | 3Ah | F16 | C16 | > + * +------------+------------------------+------------------------+ > + * | 3Bh | Reserved | G16 | > + * +------------+------------------------+------------------------+ > + * > + * To enable nearest-neighbor scaling: program scaler coefficents with > + * the center tap (Dxx) values set to 1 and all other values set to 0 as per > + * SCALER_COEFFICIENT_FORMAT > + * > + */ > + > +void skl_scaler_setup_nearest_neighbor_filter(struct drm_i915_private *dev_priv, > + enum pipe pipe, int id, int set) > +{ > + int i; > + > + /*enable the index auto increment.*/ Pointless comment, and also misformatted. > + intel_de_write_fw(dev_priv, > + SKL_PS_COEF_INDEX_SET(pipe, id, set), > + PS_COEE_INDEX_AUTO_INC); > + > + for (i = 0; i < 17 * 7; i += 2) { > + u32 tmp; > + int t; > + > + t = skl_coef_tap(i); > + tmp = skl_nearest_filter_coef(t); > + > + t = skl_coef_tap(i+1); > + tmp |= skl_nearest_filter_coef(t)<<16; Missing spaces. > + > + intel_de_write_fw(dev_priv, SKL_PS_COEF_DATA_SET(pipe, id, set), > + tmp); > + } I'd maybe reset the index back to 0 here and disable the auto-increment bit. > +} > + > static void skl_pfit_enable(const struct intel_crtc_state *crtc_state) > { > struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc); > diff --git a/drivers/gpu/drm/i915/display/intel_display.h b/drivers/gpu/drm/i915/display/intel_display.h > index adb1225a3480..88f3c77f6806 100644 > --- a/drivers/gpu/drm/i915/display/intel_display.h > +++ b/drivers/gpu/drm/i915/display/intel_display.h > @@ -587,6 +587,8 @@ void intel_crtc_arm_fifo_underrun(struct intel_crtc *crtc, > u16 skl_scaler_calc_phase(int sub, int scale, bool chroma_center); > int skl_update_scaler_crtc(struct intel_crtc_state *crtc_state); > void skl_scaler_disable(const struct intel_crtc_state *old_crtc_state); > +void skl_scaler_setup_nearest_neighbor_filter(struct drm_i915_private *dev_priv, > + enum pipe pipe, int id, int set); > void ilk_pfit_disable(const struct intel_crtc_state *old_crtc_state); > u32 glk_plane_color_ctl(const struct intel_crtc_state *crtc_state, > const struct intel_plane_state *plane_state); > -- > 2.23.0
diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c index 8f23c4d51c33..791dd908aa89 100644 --- a/drivers/gpu/drm/i915/display/intel_display.c +++ b/drivers/gpu/drm/i915/display/intel_display.c @@ -6237,6 +6237,78 @@ void skl_scaler_disable(const struct intel_crtc_state *old_crtc_state) skl_detach_scaler(crtc, i); } +static int skl_coef_tap(int i) +{ + return i % 7; +} + +static u16 skl_nearest_filter_coef(int t) +{ + return t == 3 ? 0x0800 : 0x3000; +} + +/** + * Theory behind setting nearest-neighbor integer scaling: + * + * 17 phase of 7 taps requires 119 coefficients in 60 dwords per set. + * The letter represents the filter tap (D is the center tap) and the number + * represents the coefficient set for a phase (0-16). + * + * +------------+------------------------+------------------------+ + * |Index value | Data value coeffient 1 | Data value coeffient 2 | + * +------------+------------------------+------------------------+ + * | 00h | B0 | A0 | + * +------------+------------------------+------------------------+ + * | 01h | D0 | C0 | + * +------------+------------------------+------------------------+ + * | 02h | F0 | E0 | + * +------------+------------------------+------------------------+ + * | 03h | A1 | G0 | + * +------------+------------------------+------------------------+ + * | 04h | C1 | B1 | + * +------------+------------------------+------------------------+ + * | ... | ... | ... | + * +------------+------------------------+------------------------+ + * | 38h | B16 | A16 | + * +------------+------------------------+------------------------+ + * | 39h | D16 | C16 | + * +------------+------------------------+------------------------+ + * | 3Ah | F16 | C16 | + * +------------+------------------------+------------------------+ + * | 3Bh | Reserved | G16 | + * +------------+------------------------+------------------------+ + * + * To enable nearest-neighbor scaling: program scaler coefficents with + * the center tap (Dxx) values set to 1 and all other values set to 0 as per + * SCALER_COEFFICIENT_FORMAT + * + */ + +void skl_scaler_setup_nearest_neighbor_filter(struct drm_i915_private *dev_priv, + enum pipe pipe, int id, int set) +{ + int i; + + /*enable the index auto increment.*/ + intel_de_write_fw(dev_priv, + SKL_PS_COEF_INDEX_SET(pipe, id, set), + PS_COEE_INDEX_AUTO_INC); + + for (i = 0; i < 17 * 7; i += 2) { + u32 tmp; + int t; + + t = skl_coef_tap(i); + tmp = skl_nearest_filter_coef(t); + + t = skl_coef_tap(i+1); + tmp |= skl_nearest_filter_coef(t)<<16; + + intel_de_write_fw(dev_priv, SKL_PS_COEF_DATA_SET(pipe, id, set), + tmp); + } +} + static void skl_pfit_enable(const struct intel_crtc_state *crtc_state) { struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc); diff --git a/drivers/gpu/drm/i915/display/intel_display.h b/drivers/gpu/drm/i915/display/intel_display.h index adb1225a3480..88f3c77f6806 100644 --- a/drivers/gpu/drm/i915/display/intel_display.h +++ b/drivers/gpu/drm/i915/display/intel_display.h @@ -587,6 +587,8 @@ void intel_crtc_arm_fifo_underrun(struct intel_crtc *crtc, u16 skl_scaler_calc_phase(int sub, int scale, bool chroma_center); int skl_update_scaler_crtc(struct intel_crtc_state *crtc_state); void skl_scaler_disable(const struct intel_crtc_state *old_crtc_state); +void skl_scaler_setup_nearest_neighbor_filter(struct drm_i915_private *dev_priv, + enum pipe pipe, int id, int set); void ilk_pfit_disable(const struct intel_crtc_state *old_crtc_state); u32 glk_plane_color_ctl(const struct intel_crtc_state *crtc_state, const struct intel_plane_state *plane_state);