diff options
Diffstat (limited to 'drivers/gpu/drm/i915/display/intel_hdmi.c')
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_hdmi.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c index 82674a8853c6..a57796b0a47f 100644 --- a/drivers/gpu/drm/i915/display/intel_hdmi.c +++ b/drivers/gpu/drm/i915/display/intel_hdmi.c @@ -3438,3 +3438,236 @@ void intel_hdmi_init(struct drm_i915_private *dev_priv, dig_port->aux_ch = intel_bios_port_aux_ch(dev_priv, port); intel_hdmi_init_connector(dig_port, intel_connector); } + +/* + * intel_hdmi_dsc_get_slice_height - get the dsc slice_height + * @vactive: Vactive of a display mode + * + * @return: appropriate dsc slice height for a given mode. + */ +int intel_hdmi_dsc_get_slice_height(int vactive) +{ + int slice_height; + + /* + * Slice Height determination : HDMI2.1 Section 7.7.5.2 + * Select smallest slice height >=96, that results in a valid PPS and + * requires minimum padding lines required for final slice. + * + * Assumption : Vactive is even. + */ + for (slice_height = 96; slice_height <= vactive; slice_height += 2) + if (vactive % slice_height == 0) + return slice_height; + + return 0; +} + +/* + * intel_hdmi_dsc_get_num_slices - get no. of dsc slices based on dsc encoder + * and dsc decoder capabilities + * + * @crtc_state: intel crtc_state + * @src_max_slices: maximum slices supported by the DSC encoder + * @src_max_slice_width: maximum slice width supported by DSC encoder + * @hdmi_max_slices: maximum slices supported by sink DSC decoder + * @hdmi_throughput: maximum clock per slice (MHz) supported by HDMI sink + * + * @return: num of dsc slices that can be supported by the dsc encoder + * and decoder. + */ +int +intel_hdmi_dsc_get_num_slices(const struct intel_crtc_state *crtc_state, + int src_max_slices, int src_max_slice_width, + int hdmi_max_slices, int hdmi_throughput) +{ +/* Pixel rates in KPixels/sec */ +#define HDMI_DSC_PEAK_PIXEL_RATE 2720000 +/* + * Rates at which the source and sink are required to process pixels in each + * slice, can be two levels: either atleast 340000KHz or atleast 40000KHz. + */ +#define HDMI_DSC_MAX_ENC_THROUGHPUT_0 340000 +#define HDMI_DSC_MAX_ENC_THROUGHPUT_1 400000 + +/* Spec limits the slice width to 2720 pixels */ +#define MAX_HDMI_SLICE_WIDTH 2720 + int kslice_adjust; + int adjusted_clk_khz; + int min_slices; + int target_slices; + int max_throughput; /* max clock freq. in khz per slice */ + int max_slice_width; + int slice_width; + int pixel_clock = crtc_state->hw.adjusted_mode.crtc_clock; + + if (!hdmi_throughput) + return 0; + + /* + * Slice Width determination : HDMI2.1 Section 7.7.5.1 + * kslice_adjust factor for 4:2:0, and 4:2:2 formats is 0.5, where as + * for 4:4:4 is 1.0. Multiplying these factors by 10 and later + * dividing adjusted clock value by 10. + */ + if (crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR444 || + crtc_state->output_format == INTEL_OUTPUT_FORMAT_RGB) + kslice_adjust = 10; + else + kslice_adjust = 5; + + /* + * As per spec, the rate at which the source and the sink process + * the pixels per slice are at two levels: atleast 340Mhz or 400Mhz. + * This depends upon the pixel clock rate and output formats + * (kslice adjust). + * If pixel clock * kslice adjust >= 2720MHz slices can be processed + * at max 340MHz, otherwise they can be processed at max 400MHz. + */ + + adjusted_clk_khz = DIV_ROUND_UP(kslice_adjust * pixel_clock, 10); + + if (adjusted_clk_khz <= HDMI_DSC_PEAK_PIXEL_RATE) + max_throughput = HDMI_DSC_MAX_ENC_THROUGHPUT_0; + else + max_throughput = HDMI_DSC_MAX_ENC_THROUGHPUT_1; + + /* + * Taking into account the sink's capability for maximum + * clock per slice (in MHz) as read from HF-VSDB. + */ + max_throughput = min(max_throughput, hdmi_throughput * 1000); + + min_slices = DIV_ROUND_UP(adjusted_clk_khz, max_throughput); + max_slice_width = min(MAX_HDMI_SLICE_WIDTH, src_max_slice_width); + + /* + * Keep on increasing the num of slices/line, starting from min_slices + * per line till we get such a number, for which the slice_width is + * just less than max_slice_width. The slices/line selected should be + * less than or equal to the max horizontal slices that the combination + * of PCON encoder and HDMI decoder can support. + */ + slice_width = max_slice_width; + + do { + if (min_slices <= 1 && src_max_slices >= 1 && hdmi_max_slices >= 1) + target_slices = 1; + else if (min_slices <= 2 && src_max_slices >= 2 && hdmi_max_slices >= 2) + target_slices = 2; + else if (min_slices <= 4 && src_max_slices >= 4 && hdmi_max_slices >= 4) + target_slices = 4; + else if (min_slices <= 8 && src_max_slices >= 8 && hdmi_max_slices >= 8) + target_slices = 8; + else if (min_slices <= 12 && src_max_slices >= 12 && hdmi_max_slices >= 12) + target_slices = 12; + else if (min_slices <= 16 && src_max_slices >= 16 && hdmi_max_slices >= 16) + target_slices = 16; + else + return 0; + + slice_width = DIV_ROUND_UP(crtc_state->hw.adjusted_mode.hdisplay, target_slices); + if (slice_width >= max_slice_width) + min_slices = target_slices + 1; + } while (slice_width >= max_slice_width); + + return target_slices; +} + +/* + * intel_hdmi_dsc_get_bpp - get the appropriate compressed bits_per_pixel based on + * source and sink capabilities. + * + * @src_fraction_bpp: fractional bpp supported by the source + * @slice_width: dsc slice width supported by the source and sink + * @num_slices: num of slices supported by the source and sink + * @output_format: video output format + * @hdmi_all_bpp: sink supports decoding of 1/16th bpp setting + * @hdmi_max_chunk_bytes: max bytes in a line of chunks supported by sink + * + * @return: compressed bits_per_pixel in step of 1/16 of bits_per_pixel + */ +int +intel_hdmi_dsc_get_bpp(int src_fractional_bpp, int slice_width, int num_slices, + int output_format, bool hdmi_all_bpp, + int hdmi_max_chunk_bytes) +{ + int max_dsc_bpp, min_dsc_bpp; + int target_bytes; + bool bpp_found = false; + int bpp_decrement_x16; + int bpp_target; + int bpp_target_x16; + + /* + * Get min bpp and max bpp as per Table 7.23, in HDMI2.1 spec + * Start with the max bpp and keep on decrementing with + * fractional bpp, if supported by PCON DSC encoder + * + * for each bpp we check if no of bytes can be supported by HDMI sink + */ + + /* Assuming: bpc as 8*/ + if (output_format == INTEL_OUTPUT_FORMAT_YCBCR420) { + min_dsc_bpp = 6; + max_dsc_bpp = 3 * 4; /* 3*bpc/2 */ + } else if (output_format == INTEL_OUTPUT_FORMAT_YCBCR444 || + output_format == INTEL_OUTPUT_FORMAT_RGB) { + min_dsc_bpp = 8; + max_dsc_bpp = 3 * 8; /* 3*bpc */ + } else { + /* Assuming 4:2:2 encoding */ + min_dsc_bpp = 7; + max_dsc_bpp = 2 * 8; /* 2*bpc */ + } + + /* + * Taking into account if all dsc_all_bpp supported by HDMI2.1 sink + * Section 7.7.34 : Source shall not enable compressed Video + * Transport with bpp_target settings above 12 bpp unless + * DSC_all_bpp is set to 1. + */ + if (!hdmi_all_bpp) + max_dsc_bpp = min(max_dsc_bpp, 12); + + /* + * The Sink has a limit of compressed data in bytes for a scanline, + * as described in max_chunk_bytes field in HFVSDB block of edid. + * The no. of bytes depend on the target bits per pixel that the + * source configures. So we start with the max_bpp and calculate + * the target_chunk_bytes. We keep on decrementing the target_bpp, + * till we get the target_chunk_bytes just less than what the sink's + * max_chunk_bytes, or else till we reach the min_dsc_bpp. + * + * The decrement is according to the fractional support from PCON DSC + * encoder. For fractional BPP we use bpp_target as a multiple of 16. + * + * bpp_target_x16 = bpp_target * 16 + * So we need to decrement by {1, 2, 4, 8, 16} for fractional bpps + * {1/16, 1/8, 1/4, 1/2, 1} respectively. + */ + + bpp_target = max_dsc_bpp; + + /* src does not support fractional bpp implies decrement by 16 for bppx16 */ + if (!src_fractional_bpp) + src_fractional_bpp = 1; + bpp_decrement_x16 = DIV_ROUND_UP(16, src_fractional_bpp); + bpp_target_x16 = (bpp_target * 16) - bpp_decrement_x16; + + while (bpp_target_x16 > (min_dsc_bpp * 16)) { + int bpp; + + bpp = DIV_ROUND_UP(bpp_target_x16, 16); + target_bytes = DIV_ROUND_UP((num_slices * slice_width * bpp), 8); + if (target_bytes <= hdmi_max_chunk_bytes) { + bpp_found = true; + break; + } + bpp_target_x16 -= bpp_decrement_x16; + } + if (bpp_found) + return bpp_target_x16; + + return 0; +} |