intel_dp_mst.c

/*
 * Copyright © 2008 Intel Corporation
 *             2014 Red Hat Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 */

#include <drm/drm_atomic_helper.h>
#include <drm/drm_edid.h>
#include <drm/drm_probe_helper.h>

#include "i915_drv.h"
#include "intel_atomic.h"
#include "intel_audio.h"
#include "intel_connector.h"
#include "intel_ddi.h"
#include "intel_dp.h"
#include "intel_dp_mst.h"
#include "intel_dpio_phy.h"
#include "intel_drv.h"

static int intel_dp_mst_compute_link_config(struct intel_encoder *encoder,
					    struct intel_crtc_state *crtc_state,
					    struct drm_connector_state *conn_state,
					    struct link_config_limits *limits)
{
	struct drm_atomic_state *state = crtc_state->base.state;
	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
	struct intel_dp *intel_dp = &intel_mst->primary->dp;
	struct intel_connector *connector =
		to_intel_connector(conn_state->connector);
	const struct drm_display_mode *adjusted_mode =
		&crtc_state->base.adjusted_mode;
	void *port = connector->port;
	bool constant_n = drm_dp_has_quirk(&intel_dp->desc,
					   DP_DPCD_QUIRK_CONSTANT_N);
	int bpp, slots = -EINVAL;

	crtc_state->lane_count = limits->max_lane_count;
	crtc_state->port_clock = limits->max_clock;

	for (bpp = limits->max_bpp; bpp >= limits->min_bpp; bpp -= 2 * 3) {
		crtc_state->pipe_bpp = bpp;

		crtc_state->pbn = drm_dp_calc_pbn_mode(adjusted_mode->crtc_clock,
						       crtc_state->pipe_bpp);

		slots = drm_dp_atomic_find_vcpi_slots(state, &intel_dp->mst_mgr,
						      port, crtc_state->pbn);
		if (slots == -EDEADLK)
			return slots;
		if (slots >= 0)