linux/drivers/gpu/drm/msm/dp/dp_panel.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2012-2020, The Linux Foundation. All rights reserved.
 */

#include "dp_panel.h"
#include "dp_utils.h"

#include <drm/drm_connector.h>
#include <drm/drm_edid.h>
#include <drm/drm_of.h>
#include <drm/drm_print.h>

#define DP_MAX_NUM_DP_LANES	4
#define DP_LINK_RATE_HBR2	540000 /* kbytes */

struct dp_panel_private {
	struct device *dev;
	struct drm_device *drm_dev;
	struct dp_panel dp_panel;
	struct drm_dp_aux *aux;
	struct dp_link *link;
	struct dp_catalog *catalog;
	bool panel_on;
};

static void dp_panel_read_psr_cap(struct dp_panel_private *panel)
{
	ssize_t rlen;
	struct dp_panel *dp_panel;

	dp_panel = &panel->dp_panel;

	/* edp sink */
	if (dp_panel->dpcd[DP_EDP_CONFIGURATION_CAP]) {
		rlen = drm_dp_dpcd_read(panel->aux, DP_PSR_SUPPORT,
				&dp_panel->psr_cap, sizeof(dp_panel->psr_cap));
		if (rlen == sizeof(dp_panel->psr_cap)) {
			drm_dbg_dp(panel->drm_dev,
				"psr version: 0x%x, psr_cap: 0x%x\n",
				dp_panel->psr_cap.version,
				dp_panel->psr_cap.capabilities);
		} else
			DRM_ERROR("failed to read psr info, rlen=%zd\n", rlen);
	}
}

static int dp_panel_read_dpcd(struct dp_panel *dp_panel)
{
	int rc;
	struct dp_panel_private *panel;
	struct dp_link_info *link_info;
	u8 *dpcd, major, minor;

	panel = container_of(dp_panel, struct dp_panel_private, dp_panel);
	dpcd = dp_panel->dpcd;
	rc = drm_dp_read_dpcd_caps(panel->aux, dpcd);
	if (rc)
		return rc;

	dp_panel->vsc_sdp_supported = drm_dp_vsc_sdp_supported(panel->aux, dpcd);
	link_info = &dp_panel->link_info;
	link_info->revision = dpcd[DP_DPCD_REV];
	major = (link_info->revision >> 4) & 0x0f;
	minor = link_info->revision & 0x0f;

	link_info->rate = drm_dp_max_link_rate(dpcd);
	link_info->num_lanes = drm_dp_max_lane_count(dpcd);

	/* Limit data lanes from data-lanes of endpoint property of dtsi */
	if (link_info->num_lanes > dp_panel->max_dp_lanes)
		link_info->num_lanes = dp_panel->max_dp_lanes;

	/* Limit link rate from link-frequencies of endpoint property of dtsi */
	if (link_info->rate > dp_panel->max_dp_link_rate)
		link_info->rate = dp_panel->max_dp_link_rate;

	drm_dbg_dp(panel->drm_dev, "version: %d.%d\n", major, minor);
	drm_dbg_dp(panel->drm_dev, "link_rate=%d\n", link_info->rate);
	drm_dbg_dp(panel->drm_dev, "lane_count=%d\n", link_info->num_lanes);

	if (drm_dp_enhanced_frame_cap(dpcd))
		link_info->capabilities |= DP_LINK_CAP_ENHANCED_FRAMING;

	dp_panel_read_psr_cap(panel);

	return rc;
}

static u32 dp_panel_get_supported_bpp(struct dp_panel *dp_panel,
		u32 mode_edid_bpp, u32 mode_pclk_khz)
{
	const struct dp_link_info *link_info;
	const u32 max_supported_bpp = 30, min_supported_bpp = 18;
	u32 bpp, data_rate_khz;

	bpp = min(mode_edid_bpp, max_supported_bpp);

	link_info = &dp_panel->link_info;
	data_rate_khz = link_info->num_lanes * link_info->rate * 8;

	do {
		if (mode_pclk_khz * bpp <= data_rate_khz)
			return bpp;
		bpp -= 6;
	} while (bpp > min_supported_bpp);

	return min_supported_bpp;
}

int dp_panel_read_sink_caps(struct dp_panel *dp_panel,
	struct drm_connector *connector)
{
	int rc, bw_code;
	int count;
	struct dp_panel_private *panel;

	if (!dp_panel || !connector) {
		DRM_ERROR("invalid input\n");
		return -EINVAL;
	}

	panel = container_of(dp_panel, struct dp_panel_private, dp_panel);

	drm_dbg_dp(panel->drm_dev, "max_lanes=%d max_link_rate=%d\n",
		dp_panel->max_dp_lanes, dp_panel->max_dp_link_rate);

	rc = dp_panel_read_dpcd(dp_panel);
	if (rc) {
		DRM_ERROR("read dpcd failed %d\n", rc);
		return rc;
	}

	bw_code = drm_dp_link_rate_to_bw_code(dp_panel->link_info.rate);
	if (!is_link_rate_valid(bw_code) ||
			!is_lane_count_valid(dp_panel->link_info.num_lanes) ||
			(bw_code > dp_panel->max_bw_code)) {
		DRM_ERROR("Illegal link rate=%d lane=%d\n", dp_panel->link_info.rate,
				dp_panel->link_info.num_lanes);
		return -EINVAL;
	}

	if (drm_dp_is_branch(dp_panel->dpcd)) {
		count = drm_dp_read_sink_count(panel->aux);
		if (!count) {
			panel->link->sink_count = 0;
			return -ENOTCONN;
		}
	}

	rc = drm_dp_read_downstream_info(panel->aux, dp_panel->dpcd,
					 dp_panel->downstream_ports);
	if (rc)
		return rc;

	drm_edid_free(dp_panel->drm_edid);

	dp_panel->drm_edid = drm_edid_read_ddc(connector, &panel->aux->ddc);

	drm_edid_connector_update(connector, dp_panel->drm_edid);

	if (!dp_panel->drm_edid) {
		DRM_ERROR("panel edid read failed\n");
		/* check edid read fail is due to unplug */
		if (!dp_catalog_link_is_connected(panel->catalog)) {
			rc = -ETIMEDOUT;
			goto end;
		}
	}

end:
	return rc;
}

u32 dp_panel_get_mode_bpp(struct dp_panel *dp_panel,
		u32 mode_edid_bpp, u32 mode_pclk_khz)
{
	struct dp_panel_private *panel;
	u32 bpp;

	if (!dp_panel || !mode_edid_bpp || !mode_pclk_khz) {
		DRM_ERROR("invalid input\n");
		return 0;
	}

	panel = container_of(dp_panel, struct dp_panel_private, dp_panel);

	if (dp_panel->video_test)
		bpp = dp_link_bit_depth_to_bpp(
				panel->link->test_video.test_bit_depth);
	else
		bpp = dp_panel_get_supported_bpp(dp_panel, mode_edid_bpp,
				mode_pclk_khz);

	return bpp;
}

int dp_panel_get_modes(struct dp_panel *dp_panel,
	struct drm_connector *connector)
{
	if (!dp_panel) {
		DRM_ERROR("invalid input\n");
		return -EINVAL;
	}

	if (dp_panel->drm_edid)
		return drm_edid_connector_add_modes(connector);

	return 0;
}

static u8 dp_panel_get_edid_checksum(const struct edid *edid)
{
	edid += edid->extensions;

	return edid->checksum;
}

void dp_panel_handle_sink_request(struct dp_panel *dp_panel)
{
	struct dp_panel_private *panel;

	if (!dp_panel) {
		DRM_ERROR("invalid input\n");
		return;
	}

	panel = container_of(dp_panel, struct dp_panel_private, dp_panel);

	if (panel->link->sink_request & DP_TEST_LINK_EDID_READ) {
		/* FIXME: get rid of drm_edid_raw() */
		const struct edid *edid = drm_edid_raw(dp_panel->drm_edid);
		u8 checksum;

		if (edid)
			checksum = dp_panel_get_edid_checksum(edid);
		else
			checksum = dp_panel->connector->real_edid_checksum;

		dp_link_send_edid_checksum(panel->link, checksum);
		dp_link_send_test_response(panel->link);
	}
}

void dp_panel_tpg_config(struct dp_panel *dp_panel, bool enable)
{
	struct dp_catalog *catalog;
	struct dp_panel_private *panel;

	if (!dp_panel) {
		DRM_ERROR("invalid input\n");
		return;
	}

	panel = container_of(dp_panel, struct dp_panel_private, dp_panel);
	catalog = panel->catalog;

	if (!panel->panel_on) {
		drm_dbg_dp(panel->drm_dev,
				"DP panel not enabled, handle TPG on next on\n");
		return;
	}

	if (!enable) {
		dp_catalog_panel_tpg_disable(catalog);
		return;
	}

	drm_dbg_dp(panel->drm_dev, "calling catalog tpg_enable\n");
	dp_catalog_panel_tpg_enable(catalog, &panel->dp_panel.dp_mode.drm_mode);
}

static int dp_panel_setup_vsc_sdp_yuv_420(struct dp_panel *dp_panel)
{
	struct dp_catalog *catalog;
	struct dp_panel_private *panel;
	struct dp_display_mode *dp_mode;
	struct drm_dp_vsc_sdp vsc_sdp_data;
	struct dp_sdp vsc_sdp;
	ssize_t len;

	if (!dp_panel) {
		DRM_ERROR("invalid input\n");
		return -EINVAL;
	}

	panel = container_of(dp_panel, struct dp_panel_private, dp_panel);
	catalog = panel->catalog;
	dp_mode = &dp_panel->dp_mode;

	memset(&vsc_sdp_data, 0, sizeof(vsc_sdp_data));

	/* VSC SDP header as per table 2-118 of DP 1.4 specification */
	vsc_sdp_data.sdp_type = DP_SDP_VSC;
	vsc_sdp_data.revision = 0x05;
	vsc_sdp_data.length = 0x13;

	/* VSC SDP Payload for DB16 */
	vsc_sdp_data.pixelformat = DP_PIXELFORMAT_YUV420;
	vsc_sdp_data.colorimetry = DP_COLORIMETRY_DEFAULT;

	/* VSC SDP Payload for DB17 */
	vsc_sdp_data.bpc = dp_mode->bpp / 3;
	vsc_sdp_data.dynamic_range = DP_DYNAMIC_RANGE_CTA;

	/* VSC SDP Payload for DB18 */
	vsc_sdp_data.content_type = DP_CONTENT_TYPE_GRAPHICS;

	len = drm_dp_vsc_sdp_pack(&vsc_sdp_data, &vsc_sdp);
	if (len < 0) {
		DRM_ERROR("unable to pack vsc sdp\n");
		return len;
	}

	dp_catalog_panel_enable_vsc_sdp(catalog, &vsc_sdp);

	return 0;
}

void dp_panel_dump_regs(struct dp_panel *dp_panel)
{
	struct dp_catalog *catalog;
	struct dp_panel_private *panel;

	panel = container_of(dp_panel, struct dp_panel_private, dp_panel);
	catalog = panel->catalog;

	dp_catalog_dump_regs(catalog);
}

int dp_panel_timing_cfg(struct dp_panel *dp_panel)
{
	u32 data, total_ver, total_hor;
	struct dp_catalog *catalog;
	struct dp_panel_private *panel;
	struct drm_display_mode *drm_mode;
	u32 width_blanking;
	u32 sync_start;
	u32 dp_active;
	u32 total;

	panel = container_of(dp_panel, struct dp_panel_private, dp_panel);
	catalog = panel->catalog;
	drm_mode = &panel->dp_panel.dp_mode.drm_mode;

	drm_dbg_dp(panel->drm_dev, "width=%d hporch= %d %d %d\n",
		drm_mode->hdisplay, drm_mode->htotal - drm_mode->hsync_end,
		drm_mode->hsync_start - drm_mode->hdisplay,
		drm_mode->hsync_end - drm_mode->hsync_start);

	drm_dbg_dp(panel->drm_dev, "height=%d vporch= %d %d %d\n",
		drm_mode->vdisplay, drm_mode->vtotal - drm_mode->vsync_end,
		drm_mode->vsync_start - drm_mode->vdisplay,
		drm_mode->vsync_end - drm_mode->vsync_start);

	total_hor = drm_mode->htotal;

	total_ver = drm_mode->vtotal;

	data = total_ver;
	data <<= 16;
	data |= total_hor;

	total = data;

	data = (drm_mode->vtotal - drm_mode->vsync_start);
	data <<= 16;
	data |= (drm_mode->htotal - drm_mode->hsync_start);

	sync_start = data;

	data = drm_mode->vsync_end - drm_mode->vsync_start;
	data <<= 16;
	data |= (panel->dp_panel.dp_mode.v_active_low << 31);
	data |= drm_mode->hsync_end - drm_mode->hsync_start;
	data |= (panel->dp_panel.dp_mode.h_active_low << 15);

	width_blanking = data;

	data = drm_mode->vdisplay;
	data <<= 16;
	data |= drm_mode->hdisplay;

	dp_active = data;

	dp_catalog_panel_timing_cfg(catalog, total, sync_start, width_blanking, dp_active);

	if (dp_panel->dp_mode.out_fmt_is_yuv_420)
		dp_panel_setup_vsc_sdp_yuv_420(dp_panel);

	panel->panel_on = true;

	return 0;
}

int dp_panel_init_panel_info(struct dp_panel *dp_panel)
{
	struct drm_display_mode *drm_mode;
	struct dp_panel_private *panel;

	drm_mode = &dp_panel->dp_mode.drm_mode;

	panel = container_of(dp_panel, struct dp_panel_private, dp_panel);

	/*
	 * print resolution info as this is a result
	 * of user initiated action of cable connection
	 */
	drm_dbg_dp(panel->drm_dev, "SET NEW RESOLUTION:\n");
	drm_dbg_dp(panel->drm_dev, "%dx%d@%dfps\n",
		drm_mode->hdisplay, drm_mode->vdisplay, drm_mode_vrefresh(drm_mode));
	drm_dbg_dp(panel->drm_dev,
			"h_porches(back|front|width) = (%d|%d|%d)\n",
			drm_mode->htotal - drm_mode->hsync_end,
			drm_mode->hsync_start - drm_mode->hdisplay,
			drm_mode->hsync_end - drm_mode->hsync_start);
	drm_dbg_dp(panel->drm_dev,
			"v_porches(back|front|width) = (%d|%d|%d)\n",
			drm_mode->vtotal - drm_mode->vsync_end,
			drm_mode->vsync_start - drm_mode->vdisplay,
			drm_mode->vsync_end - drm_mode->vsync_start);
	drm_dbg_dp(panel->drm_dev, "pixel clock (KHz)=(%d)\n",
				drm_mode->clock);
	drm_dbg_dp(panel->drm_dev, "bpp = %d\n", dp_panel->dp_mode.bpp);

	dp_panel->dp_mode.bpp = dp_panel_get_mode_bpp(dp_panel, dp_panel->dp_mode.bpp,
						      dp_panel->dp_mode.drm_mode.clock);

	drm_dbg_dp(panel->drm_dev, "updated bpp = %d\n",
				dp_panel->dp_mode.bpp);

	return 0;
}

static u32 dp_panel_link_frequencies(struct device_node *of_node)
{
	struct device_node *endpoint;
	u64 frequency = 0;
	int cnt;

	endpoint = of_graph_get_endpoint_by_regs(of_node, 1, 0); /* port@1 */
	if (!endpoint)
		return 0;

	cnt = of_property_count_u64_elems(endpoint, "link-frequencies");

	if (cnt > 0)
		of_property_read_u64_index(endpoint, "link-frequencies",
						cnt - 1, &frequency);
	of_node_put(endpoint);

	do_div(frequency,
		10 * /* from symbol rate to link rate */
		1000); /* kbytes */

	return frequency;
}

static int dp_panel_parse_dt(struct dp_panel *dp_panel)
{
	struct dp_panel_private *panel;
	struct device_node *of_node;
	int cnt;

	panel = container_of(dp_panel, struct dp_panel_private, dp_panel);
	of_node = panel->dev->of_node;

	/*
	 * data-lanes is the property of dp_out endpoint
	 */
	cnt = drm_of_get_data_lanes_count_ep(of_node, 1, 0, 1, DP_MAX_NUM_DP_LANES);
	if (cnt < 0) {
		/* legacy code, data-lanes is the property of mdss_dp node */
		cnt = drm_of_get_data_lanes_count(of_node, 1, DP_MAX_NUM_DP_LANES);
	}

	if (cnt > 0)
		dp_panel->max_dp_lanes = cnt;
	else
		dp_panel->max_dp_lanes = DP_MAX_NUM_DP_LANES; /* 4 lanes */

	dp_panel->max_dp_link_rate = dp_panel_link_frequencies(of_node);
	if (!dp_panel->max_dp_link_rate)
		dp_panel->max_dp_link_rate = DP_LINK_RATE_HBR2;

	return 0;
}

struct dp_panel *dp_panel_get(struct dp_panel_in *in)
{
	struct dp_panel_private *panel;
	struct dp_panel *dp_panel;
	int ret;

	if (!in->dev || !in->catalog || !in->aux || !in->link) {
		DRM_ERROR("invalid input\n");
		return ERR_PTR(-EINVAL);
	}

	panel = devm_kzalloc(in->dev, sizeof(*panel), GFP_KERNEL);
	if (!panel)
		return ERR_PTR(-ENOMEM);

	panel->dev = in->dev;
	panel->aux = in->aux;
	panel->catalog = in->catalog;
	panel->link = in->link;

	dp_panel = &panel->dp_panel;
	dp_panel->max_bw_code = DP_LINK_BW_8_1;

	ret = dp_panel_parse_dt(dp_panel);
	if (ret)
		return ERR_PTR(ret);

	return dp_panel;
}

void dp_panel_put(struct dp_panel *dp_panel)
{
	if (!dp_panel)
		return;

	drm_edid_free(dp_panel->drm_edid);
}