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

/*
 * Copyright (c) 2012-2017, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#define pr_fmt(fmt)	"[drm-dp] %s: " fmt, __func__

#include "dp_panel.h"

#define DP_PANEL_DEFAULT_BPP 24

enum {
	DP_LINK_RATE_MULTIPLIER = 27000000,
};

struct dp_panel_private {
	struct device *dev;
	struct dp_panel dp_panel;
	struct dp_aux *aux;
	struct dp_catalog_panel *catalog;
	bool lane_switch_supported;
	bool aux_cfg_update_done;
};

static int dp_panel_read_dpcd(struct dp_panel *dp_panel)
{
	int rlen, rc = 0;
	struct dp_panel_private *panel;
	struct drm_dp_link *link_info;
	u8 major = 0, minor = 0;
	unsigned long caps = DP_LINK_CAP_ENHANCED_FRAMING;

	if (!dp_panel) {
		pr_err("invalid input\n");
		rc = -EINVAL;
		goto end;
	}

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

	rlen = drm_dp_dpcd_read(panel->aux->drm_aux, DP_DPCD_REV,
		dp_panel->dpcd, (DP_RECEIVER_CAP_SIZE + 1));
	if (rlen < (DP_RECEIVER_CAP_SIZE + 1)) {
		pr_err("dpcd read failed, rlen=%d\n", rlen);
		rc = -EINVAL;
		goto end;
	}

	link_info->revision = dp_panel->dpcd[DP_DPCD_REV];

	major = (link_info->revision >> 4) & 0x0f;
	minor = link_info->revision & 0x0f;
	pr_debug("version: %d.%d\n", major, minor);

	link_info->rate =
		drm_dp_bw_code_to_link_rate(dp_panel->dpcd[DP_MAX_LINK_RATE]);
	pr_debug("link_rate=%d\n", link_info->rate);

	if (panel->lane_switch_supported)
		link_info->num_lanes = dp_panel->dpcd[DP_MAX_LANE_COUNT] &
			DP_MAX_LANE_COUNT_MASK;
	else
		link_info->num_lanes = 2;

	pr_debug("lane_count=%d\n", link_info->num_lanes);

	if (dp_panel->dpcd[DP_MAX_LANE_COUNT] & DP_ENHANCED_FRAME_CAP)
		link_info->capabilities |= caps;

end:
	return rc;
}


static int dp_panel_read_edid(struct dp_panel *dp_panel,
	struct drm_connector *connector)
{
	int retry_cnt = 0;
	const int max_retry = 10;
	struct dp_panel_private *panel;

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

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

	do {
		sde_get_edid(connector, &panel->aux->drm_aux->ddc,
			(void **)&dp_panel->edid_ctrl);
		if (!dp_panel->edid_ctrl->edid) {
			pr_err("EDID read failed\n");
			retry_cnt++;
			panel->aux->reconfig(panel->aux);
			panel->aux_cfg_update_done = true;
		} else {
			return 0;
		}
	} while (retry_cnt < max_retry);

	return -EINVAL;
}

static int dp_panel_read_sink_caps(struct dp_panel *dp_panel,
	struct drm_connector *connector)
{
	int rc = 0;
	struct dp_panel_private *panel;

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

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

	rc = dp_panel_read_dpcd(dp_panel);
	if (rc) {
		pr_err("panel dpcd read failed\n");
		return rc;
	}

	rc = dp_panel_read_edid(dp_panel, connector);
	if (rc) {
		pr_err("panel edid read failed\n");
		return rc;
	}

	if (panel->aux_cfg_update_done) {
		pr_debug("read DPCD with updated AUX config\n");
		dp_panel_read_dpcd(dp_panel);
		panel->aux_cfg_update_done = false;
	}

	return 0;
}

static u32 dp_panel_get_max_pclk(struct dp_panel *dp_panel)
{
	struct drm_dp_link *link_info;
	const u8 num_components = 3;
	u32 bpc = 0, bpp = 0, max_data_rate_khz = 0, max_pclk_rate_khz = 0;

	if (!dp_panel) {
		pr_err("invalid input\n");
		return 0;
	}

	link_info = &dp_panel->link_info;

	bpc = sde_get_sink_bpc(dp_panel->edid_ctrl);
	bpp = bpc * num_components;
	if (!bpp)
		bpp = DP_PANEL_DEFAULT_BPP;

	max_data_rate_khz = (link_info->num_lanes * link_info->rate * 8);
	max_pclk_rate_khz = max_data_rate_khz / bpp;

	pr_debug("bpp=%d, max_lane_cnt=%d\n", bpp, link_info->num_lanes);
	pr_debug("max_data_rate=%dKHz, max_pclk_rate=%dKHz\n",
		max_data_rate_khz, max_pclk_rate_khz);

	return max_pclk_rate_khz;
}

static int dp_panel_timing_cfg(struct dp_panel *dp_panel)
{
	int rc = 0;
	u32 data, total_ver, total_hor;
	struct dp_catalog_panel *catalog;
	struct dp_panel_private *panel;
	struct dp_panel_info *pinfo;

	if (!dp_panel) {
		pr_err("invalid input\n");
		rc = -EINVAL;
		goto end;
	}

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

	pr_debug("width=%d hporch= %d %d %d\n",
		pinfo->h_active, pinfo->h_back_porch,
		pinfo->h_front_porch, pinfo->h_sync_width);

	pr_debug("height=%d vporch= %d %d %d\n",
		pinfo->v_active, pinfo->v_back_porch,
		pinfo->v_front_porch, pinfo->v_sync_width);

	total_hor = pinfo->h_active + pinfo->h_back_porch +
		pinfo->h_front_porch + pinfo->h_sync_width;

	total_ver = pinfo->v_active + pinfo->v_back_porch +
			pinfo->v_front_porch + pinfo->v_sync_width;

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

	catalog->total = data;

	data = (pinfo->v_back_porch + pinfo->v_sync_width);
	data <<= 16;
	data |= (pinfo->h_back_porch + pinfo->h_sync_width);

	catalog->sync_start = data;

	data = pinfo->v_sync_width;
	data <<= 16;
	data |= (pinfo->v_active_low << 31);
	data |= pinfo->h_sync_width;
	data |= (pinfo->h_active_low << 15);

	catalog->width_blanking = data;

	data = pinfo->v_active;
	data <<= 16;
	data |= pinfo->h_active;

	catalog->dp_active = data;

	panel->catalog->timing_cfg(catalog);
end:
	return rc;
}

static int dp_panel_edid_register(struct dp_panel *dp_panel)
{
	int rc = 0;

	if (!dp_panel) {
		pr_err("invalid input\n");
		rc = -EINVAL;
		goto end;
	}

	dp_panel->edid_ctrl = sde_edid_init();
	if (!dp_panel->edid_ctrl) {
		pr_err("sde edid init for DP failed\n");
		rc = -ENOMEM;
		goto end;
	}
end:
	return rc;
}

static void dp_panel_edid_deregister(struct dp_panel *dp_panel)
{
	if (!dp_panel) {
		pr_err("invalid input\n");
		return;
	}

	sde_edid_deinit((void **)&dp_panel->edid_ctrl);
}

static int dp_panel_init_panel_info(struct dp_panel *dp_panel)
{
	int rc = 0;
	struct dp_panel_info *pinfo;

	if (!dp_panel) {
		pr_err("invalid input\n");
		rc = -EINVAL;
		goto end;
	}

	pinfo = &dp_panel->pinfo;

	/*
	 * print resolution info as this is a result
	 * of user initiated action of cable connection
	 */
	pr_info("SET NEW RESOLUTION:\n");
	pr_info("%dx%d@%dfps\n", pinfo->h_active,
		pinfo->v_active, pinfo->refresh_rate);
	pr_info("h_porches(back|front|width) = (%d|%d|%d)\n",
			pinfo->h_back_porch,
			pinfo->h_front_porch,
			pinfo->h_sync_width);
	pr_info("v_porches(back|front|width) = (%d|%d|%d)\n",
			pinfo->v_back_porch,
			pinfo->v_front_porch,
			pinfo->v_sync_width);
	pr_info("pixel clock (KHz)=(%d)\n", pinfo->pixel_clk_khz);
	pr_info("bpp = %d\n", pinfo->bpp);
	pr_info("active low (h|v)=(%d|%d)\n", pinfo->h_active_low,
		pinfo->v_active_low);

	pinfo->bpp = max_t(u32, 18, min_t(u32, pinfo->bpp, 30));
	pr_info("updated bpp = %d\n", pinfo->bpp);
end:
	return rc;
}

static u32 dp_panel_get_min_req_link_rate(struct dp_panel *dp_panel)
{
	const u32 encoding_factx10 = 8;
	u32 min_link_rate_khz = 0, lane_cnt;
	struct dp_panel_info *pinfo;

	if (!dp_panel) {
		pr_err("invalid input\n");
		goto end;
	}

	lane_cnt = dp_panel->link_info.num_lanes;
	pinfo = &dp_panel->pinfo;

	/* num_lanes * lane_count * 8 >= pclk * bpp * 10 */
	min_link_rate_khz = pinfo->pixel_clk_khz /
				(lane_cnt * encoding_factx10);
	min_link_rate_khz *= pinfo->bpp;

	pr_debug("min lclk req=%d khz for pclk=%d khz, lanes=%d, bpp=%d\n",
		min_link_rate_khz, pinfo->pixel_clk_khz, lane_cnt,
		pinfo->bpp);
end:
	return min_link_rate_khz;
}

struct dp_panel *dp_panel_get(struct device *dev, struct dp_aux *aux,
				struct dp_catalog_panel *catalog)
{
	int rc = 0;
	struct dp_panel_private *panel;
	struct dp_panel *dp_panel;

	if (!dev || !aux || !catalog) {
		pr_err("invalid input\n");
		rc = -EINVAL;
		goto error;
	}

	panel = devm_kzalloc(dev, sizeof(*panel), GFP_KERNEL);
	if (!panel) {
		rc = -ENOMEM;
		goto error;
	}

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

	dp_panel = &panel->dp_panel;
	panel->aux_cfg_update_done = false;

	dp_panel->sde_edid_register = dp_panel_edid_register;
	dp_panel->sde_edid_deregister = dp_panel_edid_deregister;
	dp_panel->init_info = dp_panel_init_panel_info;
	dp_panel->timing_cfg = dp_panel_timing_cfg;
	dp_panel->read_sink_caps = dp_panel_read_sink_caps;
	dp_panel->get_min_req_link_rate = dp_panel_get_min_req_link_rate;
	dp_panel->get_max_pclk = dp_panel_get_max_pclk;

	return dp_panel;
error:
	return ERR_PTR(rc);
}

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

	if (!dp_panel)
		return;

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

	devm_kfree(panel->dev, panel);
}