diff options
Diffstat (limited to 'drivers/gpu/drm/i915/display/intel_display.c')
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_display.c | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c index 6ae085c6b361..e829203befad 100644 --- a/drivers/gpu/drm/i915/display/intel_display.c +++ b/drivers/gpu/drm/i915/display/intel_display.c @@ -6289,6 +6289,105 @@ void skl_scaler_disable(const struct intel_crtc_state *old_crtc_state) skl_detach_scaler(crtc, i); } +static int cnl_coef_tap(int i) +{ + return i % 7; +} + +static u16 cnl_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 + * + */ + +static void cnl_program_nearest_filter_coefs(struct drm_i915_private *dev_priv, + enum pipe pipe, int id, int set) +{ + int i; + + intel_de_write_fw(dev_priv, CNL_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 = cnl_coef_tap(i); + tmp = cnl_nearest_filter_coef(t); + + t = cnl_coef_tap(i + 1); + tmp |= cnl_nearest_filter_coef(t) << 16; + + intel_de_write_fw(dev_priv, CNL_PS_COEF_DATA_SET(pipe, id, set), + tmp); + } + + intel_de_write_fw(dev_priv, CNL_PS_COEF_INDEX_SET(pipe, id, set), 0); +} + +inline u32 skl_scaler_get_filter_select(enum drm_scaling_filter filter, int set) +{ + if (filter == DRM_SCALING_FILTER_NEAREST_NEIGHBOR) { + return (PS_FILTER_PROGRAMMED | + PS_Y_VERT_FILTER_SELECT(set) | + PS_Y_HORZ_FILTER_SELECT(set) | + PS_UV_VERT_FILTER_SELECT(set) | + PS_UV_HORZ_FILTER_SELECT(set)); + } + + return PS_FILTER_MEDIUM; +} + +void skl_scaler_setup_filter(struct drm_i915_private *dev_priv, enum pipe pipe, + int id, int set, enum drm_scaling_filter filter) +{ + switch (filter) { + case DRM_SCALING_FILTER_DEFAULT: + break; + case DRM_SCALING_FILTER_NEAREST_NEIGHBOR: + cnl_program_nearest_filter_coefs(dev_priv, pipe, id, set); + break; + default: + MISSING_CASE(filter); + } +} + static void skl_pfit_enable(const struct intel_crtc_state *crtc_state) { struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc); |