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Commit 227b6ebb authored by Narender Ankam's avatar Narender Ankam Committed by Gerrit - the friendly Code Review server
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drm/msm/dp: read extended dpcd if present 



In case sink supports DPCD 1.4 version, check if corresponding
DPCP is available at extended receiver capability field.
Read the extended receiver capability field for DPCD if present.

Change-Id: I60b93482b403ad0a3413b46214f4c288fa27c2da
Signed-off-by: default avatarAjay Singh Parmar <aparmar@codeaurora.org>
Signed-off-by: default avatarNarender Ankam <nankam@codeaurora.org>
parent 62337538

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

+51 −26
Original line number Diff line number Diff line 
/*

 * Copyright (c) 2012-2020, The Linux Foundation. All rights reserved.

 * Copyright (c) 2012-2021, 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
@@ -22,6 +22,7 @@ 
#define DP_MAX_DS_PORT_COUNT 1



#define DPRX_FEATURE_ENUMERATION_LIST 0x2210

#define DPRX_EXTENDED_DPCD_FIELD 0x2200

#define VSC_SDP_EXTENSION_FOR_COLORIMETRY_SUPPORTED BIT(3)

#define VSC_EXT_VESA_SDP_SUPPORTED BIT(4)

#define VSC_EXT_VESA_SDP_CHAINING_SUPPORTED BIT(5)
@@ -122,8 +123,9 @@ static int dp_panel_read_dpcd(struct dp_panel *dp_panel, bool multi_func) 
	int rlen, rc = 0;

	struct dp_panel_private *panel;

	struct drm_dp_link *link_info;

	u8 *dpcd, rx_feature;

	u32 dfp_count = 0;

	struct drm_dp_aux *drm_aux;

	u8 *dpcd, rx_feature, temp;

	u32 dfp_count = 0, offset = DP_DPCD_REV;

	unsigned long caps = DP_LINK_CAP_ENHANCED_FRAMING;



	if (!dp_panel) {
@@ -135,10 +137,33 @@ static int dp_panel_read_dpcd(struct dp_panel *dp_panel, bool multi_func) 
	dpcd = dp_panel->dpcd;



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

	drm_aux = panel->aux->drm_aux;

	link_info = &dp_panel->link_info;



	if (!panel->custom_dpcd) {

		rlen = drm_dp_dpcd_read(panel->aux->drm_aux, DP_DPCD_REV,

	/* reset vsc data */

	panel->vsc_supported = false;

	panel->vscext_supported = false;

	panel->vscext_chaining_supported = false;



	if (panel->custom_dpcd) {

		pr_debug("skip dpcd read in debug mode\n");

		goto skip_dpcd_read;

	}



	rlen = drm_dp_dpcd_read(drm_aux, DP_TRAINING_AUX_RD_INTERVAL, &temp, 1);

	if (rlen != 1) {

		pr_err("error reading DP_TRAINING_AUX_RD_INTERVAL\n");

		rc = -EINVAL;

		goto end;

	}



	/* check for EXTENDED_RECEIVER_CAPABILITY_FIELD_PRESENT */

	if (temp & BIT(7)) {

		pr_debug("using EXTENDED_RECEIVER_CAPABILITY_FIELD\n");

		offset = DPRX_EXTENDED_DPCD_FIELD;

	}



	rlen = drm_dp_dpcd_read(drm_aux, offset,

		dp_panel->dpcd, (DP_RECEIVER_CAP_SIZE + 1));

	if (rlen < (DP_RECEIVER_CAP_SIZE + 1)) {

		pr_err("dpcd read failed, rlen=%d\n", rlen);
@@ -149,30 +174,27 @@ static int dp_panel_read_dpcd(struct dp_panel *dp_panel, bool multi_func) 


		goto end;

	}

	}



	print_hex_dump(KERN_DEBUG, "[drm-dp] SINK DPCD: ",

		DUMP_PREFIX_NONE, 8, 1, dp_panel->dpcd, rlen, false);



	rlen = drm_dp_dpcd_read(panel->aux->drm_aux,

		DPRX_FEATURE_ENUMERATION_LIST, &rx_feature, 1);

	if (rlen != 1) {

		pr_debug("failed to read DPRX_FEATURE_ENUMERATION_LIST\n");

		panel->vsc_supported = false;

		panel->vscext_supported = false;

		panel->vscext_chaining_supported = false;

	} else {

		goto skip_dpcd_read;

	}

	panel->vsc_supported = !!(rx_feature &

		VSC_SDP_EXTENSION_FOR_COLORIMETRY_SUPPORTED);



		panel->vscext_supported = !!(rx_feature &

			VSC_EXT_VESA_SDP_SUPPORTED);



	panel->vscext_supported = !!(rx_feature & VSC_EXT_VESA_SDP_SUPPORTED);

	panel->vscext_chaining_supported = !!(rx_feature &

			VSC_EXT_VESA_SDP_CHAINING_SUPPORTED);

	}



	pr_debug("vsc=%d, vscext=%d, vscext_chaining=%d\n",

		panel->vsc_supported, panel->vscext_supported,

		panel->vscext_chaining_supported);



skip_dpcd_read:

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



	panel->major = (link_info->revision >> 4) & 0x0f;
@@ -271,6 +293,7 @@ static int dp_panel_set_edid(struct dp_panel *dp_panel, u8 *edid, 
		panel->custom_edid = false;

	}



	pr_debug("%d\n", panel->custom_edid);

	return 0;

}
@@ -295,6 +318,8 @@ static int dp_panel_set_dpcd(struct dp_panel *dp_panel, u8 *dpcd) 
		panel->custom_dpcd = false;

	}



	pr_debug("%d\n", panel->custom_dpcd);



	return 0;

}