system/dev/display/vim-display/edid.cpp

// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <ddk/debug.h>

#include "vim-display.h"
#include "edid.h"

zx_status_t get_vic(const display_mode_t* disp_timing, struct hdmi_param* p)
{
    // Monitor has its own preferred timings. Use that
    p->timings.interlace_mode =     disp_timing->flags & MODE_FLAG_INTERLACED;
    p->timings.pfreq =              (disp_timing->pixel_clock_10khz * 10); // KHz
    //TODO: pixel repetition is 0 for most progressive. We don't support interlaced
    p->timings.pixel_repeat =       0;
    p->timings.hactive =            disp_timing->h_addressable;
    p->timings.hblank =             disp_timing->h_blanking;
    p->timings.hfront =             disp_timing->h_front_porch;
    p->timings.hsync =              disp_timing->h_sync_pulse;
    p->timings.htotal =             (p->timings.hactive) + (p->timings.hblank);
    p->timings.hback =              (p->timings.hblank) - (p->timings.hfront + p->timings.hsync);
    p->timings.hpol =               disp_timing->flags & MODE_FLAG_HSYNC_POSITIVE;

    p->timings.vactive =            disp_timing->v_addressable;
    p->timings.vblank0 =            disp_timing->v_blanking;
    p->timings.vfront =             disp_timing->v_front_porch;
    p->timings.vsync =              disp_timing->v_sync_pulse;
    p->timings.vtotal =             (p->timings.vactive) + (p->timings.vblank0);
    p->timings.vback =              (p->timings.vblank0) - (p->timings.vfront + p->timings.vsync);
    p->timings.vpol =               disp_timing->flags & MODE_FLAG_VSYNC_POSITIVE;

    //FIXE: VENC Repeat is undocumented. It seems to be only needed for the following
    // resolutions: 1280x720p60, 1280x720p50, 720x480p60, 720x480i60, 720x576p50, 720x576i50
    // For now, we will simply not support this feature.
    p->timings.venc_pixel_repeat = 0;
    // Let's make sure we support what we've got so far
    if (p->timings.interlace_mode) {
        return ZX_ERR_NOT_SUPPORTED;
    }

    if (p->timings.vactive == 2160) {
        DISP_INFO("4K Monitor Detected.\n");

        if (p->timings.pfreq == 533250) {
            // FIXME: 4K with reduced blanking (533.25MHz) does not work
            DISP_INFO("4K @ 30Hz\n");
            p->timings.interlace_mode =     0;
            p->timings.pfreq =              (297000); // KHz
            p->timings.pixel_repeat =       0;
            p->timings.hactive =            3840;
            p->timings.hblank =             560;
            p->timings.hfront =             176;
            p->timings.hsync =              88;
            p->timings.htotal =             (p->timings.hactive) + (p->timings.hblank);
            p->timings.hback =              (p->timings.hblank) -
                                               (p->timings.hfront + p->timings.hsync);
            p->timings.hpol =               1;
            p->timings.vactive =            2160;
            p->timings.vblank0 =            90;
            p->timings.vfront =             8;
            p->timings.vsync =              10;
            p->timings.vtotal =             (p->timings.vactive) + (p->timings.vblank0);
            p->timings.vback =              (p->timings.vblank0) -
                                               (p->timings.vfront + p->timings.vsync);
            p->timings.vpol =               1;
        }
    }

    if (p->timings.pfreq > 500000) {
        p->is4K = true;
    } else {
        p->is4K = false;
    }

    if (p->timings.hactive * 3 == p->timings.vactive * 4) {
        p->aspect_ratio = HDMI_ASPECT_RATIO_4x3;
    } else if (p->timings.hactive * 9 == p->timings.vactive * 16) {
        p->aspect_ratio = HDMI_ASPECT_RATIO_16x9;
    } else {
        p->aspect_ratio = HDMI_ASPECT_RATIO_NONE;
    }

    p->colorimetry = HDMI_COLORIMETRY_ITU601;

    if (p->timings.pfreq > 500000) {
        p->phy_mode = 1;
    } else if (p->timings.pfreq > 200000) {
        p->phy_mode = 2;
    } else if (p->timings.pfreq > 100000) {
        p->phy_mode = 3;
    } else {
        p->phy_mode = 4;
    }

    //TODO: We probably need a more sophisticated method for calculating
    // clocks. This will do for now.
    p->pll_p_24b.viu_channel =          1;
    p->pll_p_24b.viu_type =             VIU_ENCP;
    p->pll_p_24b.vid_pll_div =          VID_PLL_DIV_5;
    p->pll_p_24b.vid_clk_div =          2;
    p->pll_p_24b.hdmi_tx_pixel_div =    1;
    p->pll_p_24b.encp_div =             1;
    p->pll_p_24b.od1 =                  1;
    p->pll_p_24b.od2 =                  1;
    p->pll_p_24b.od3 =                  1;

    p->pll_p_24b.hpll_clk_out = (p->timings.pfreq * 10);
    while (p->pll_p_24b.hpll_clk_out < 2900000) {
        if (p->pll_p_24b.od1 < 4) {
            p->pll_p_24b.od1 *= 2;
            p->pll_p_24b.hpll_clk_out *= 2;
        } else if (p->pll_p_24b.od2 < 4) {
            p->pll_p_24b.od2 *= 2;
            p->pll_p_24b.hpll_clk_out *= 2;
        } else if (p->pll_p_24b.od3 < 4) {
            p->pll_p_24b.od3 *= 2;
            p->pll_p_24b.hpll_clk_out *= 2;
        } else {
            return ZX_ERR_OUT_OF_RANGE;
        }
    }
    if(p->pll_p_24b.hpll_clk_out > 6000000) {
        DISP_ERROR("Something went wrong in clock calculation (pll_out = %d)\n",
            p->pll_p_24b.hpll_clk_out);
        return ZX_ERR_OUT_OF_RANGE;
    }

    return ZX_OK;
}