[RFC,1/5] drm/hdmi21: Define frl_dfm structure

Commit Message

Kulkarni, Vandita Feb. 3, 2022, 5:50 a.m. UTC

Define frl_dfm structure to hold frl characteristics
needed for frl capacity computation in order to
meet the data flow metering requirement.

Signed-off-by: Vandita Kulkarni <[e-mail]>
---
 include/drm/drm_frl_dfm_helper.h | 126 +++++++++++++++++++++++++++++++
 1 file changed, 126 insertions(+)
 create mode 100644 include/drm/drm_frl_dfm_helper.h

Patch

diff --git a/include/drm/drm_frl_dfm_helper.h b/include/drm/drm_frl_dfm_helper.h
new file mode 100644
index 000000000000..16b8fcc7cbcc
--- /dev/null
+++ b/include/drm/drm_frl_dfm_helper.h
@@ -0,0 +1,126 @@ 
+/* SPDX-License-Identifier: MIT
+ * Copyright © 2022 Intel Corp
+ */
+
+#ifndef DRM_FRL_DFM_H_
+#define DRM_FRL_DFM_H_
+
+/* DFM constraints and tolerance values from HDMI2.1 spec */
+#define TB_BORROWED_MAX			400
+#define FRL_CHAR_PER_CHAR_BLK		510
+/* Tolerance pixel clock unit is in  mHz */
+#define TOLERANCE_PIXEL_CLOCK		5
+#define TOLERANCE_FRL_BIT_RATE		300
+#define TOLERANCE_AUDIO_CLOCK		1000
+#define ACR_RATE_MAX			1500
+#define EFFICIENCY_MULTIPLIER		1000
+#define OVERHEAD_M			(3 * EFFICIENCY_MULTIPLIER / 1000)
+#define BPP_MULTIPLIER			16
+#define FRL_TIMING_NS_MULTIPLIER	1000000000
+
+/* ALl the input config needed to compute DFM requirements */
+struct drm_frl_dfm_input_config {
+
+	/*
+	 * Pixel clock rate kHz, when FVA is
+	 * enabled this rate is the rate after adjustment
+	 */
+	u32 pixel_clock_nominal_khz;
+
+	/* active pixels per line */
+	u32 hactive;
+
+	/* Blanking pixels per line */
+	u32 hblank;
+
+	/* Bits per component */
+	u32 bpc;
+
+	/* Pixel encoding */
+	u32 color_format;
+
+	/* FRL bit rate in kbps */
+	u32 bit_rate_kbps;
+
+	/* FRL lanes */
+	u32 lanes;
+
+	/* Number of audio channels */
+	u32 audio_channels;
+
+	/* Audio rate in Hz */
+	u32 audio_hz;
+
+	/* Selected bpp target value */
+	u32 target_bpp_16;
+
+	/*
+	 * Number of horizontal pixels in a slice.
+	 * Equivalent to PPS parameter slice_width
+	 */
+	u32 slice_width;
+};
+
+/* Computed dfm parameters as per the HDMI2.1 spec */
+struct drm_frl_dfm_params {
+
+	/*
+	 * Link overhead in percentage
+	 * multiplied by 1000 (efficiency multiplier)
+	 */
+	u32 overhead_max;
+
+	/* Maximum pixel rate in kHz */
+	u32 pixel_clock_max_khz;
+
+	/* Minimum video line period in nano sec */
+	u32 line_time_ns;
+
+	/* worst case slow frl character rate in kbps */
+	u32 char_rate_min_kbps;
+
+	/* minimum total frl charecters per line perios */
+	u32 cfrl_line;
+
+	/* Average tribyte rate in khz */
+	u32 ftb_avg_k;
+
+	/* Audio characteristics */
+
+	/*  number of audio packets needed during hblank */
+	u32 num_audio_pkts_line;
+
+	/*
+	 *  Minimum required hblank assuming no control preiod
+	 *  RC compression
+	 */
+	u32 hblank_audio_min;
+
+	/* Number of tribytes required to carry active video */
+	u32 tb_active;
+
+	/* Total available tribytes during the blanking period */
+	u32 tb_blank;
+
+	/*
+	 * Number of tribytes required to be transmitted during
+	 * the hblank period
+	 */
+	u32 tb_borrowed;
+
+	/* DSC frl characteristics */
+
+	/* Tribytes required to carry the target bpp */
+	u32 hcactive_target;
+
+	/* tribytes available during blanking with target bpp */
+	u32 hcblank_target;
+};
+
+/* FRL DFM structure to hold involved in DFM computation */
+struct drm_hdmi_frl_dfm {
+	struct drm_frl_dfm_input_config config;
+	struct drm_frl_dfm_params params;
+};
+
+#endif