drm/msm/dp: move link-specific parsing from dp_panel to dp_link

Since max_dp_lanes and max_dp_link_rate are link-specific parameters, move
their parsing from dp_panel to dp_link for better separation of concerns.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: Xiangxu Yin <xiangxu.yin@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/675643/
Link: https://lore.kernel.org/r/20250919-add-displayport-support-for-qcs615-platform-v5-13-eae6681f4002@oss.qualcomm.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>

4 files changed, 70 insertions, 72 deletions

diff --git a/drivers/gpu/drm/msm/dp/dp_link.c b/drivers/gpu/drm/msm/dp/dp_link.c
index 66e1bbd80db3..2aeb3ecf76fa 100644
--- a/drivers/gpu/drm/msm/dp/dp_link.c
+++ b/drivers/gpu/drm/msm/dp/dp_link.c
@@ -6,12 +6,14 @@
 #define pr_fmt(fmt)	"[drm-dp] %s: " fmt, __func__
 
 #include <drm/drm_device.h>
+#include <drm/drm_of.h>
 #include <drm/drm_print.h>
 
 #include "dp_reg.h"
 #include "dp_link.h"
 #include "dp_panel.h"
 
+#define DP_LINK_RATE_HBR2      540000 /* kbytes */
 #define DP_TEST_REQUEST_MASK		0x7F
 
 enum audio_sample_rate {
@@ -1210,10 +1212,61 @@ u32 msm_dp_link_get_test_bits_depth(struct msm_dp_link *msm_dp_link, u32 bpp)
 	return tbd;
 }
 
+static u32 msm_dp_link_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 msm_dp_link_parse_dt(struct device *dev, struct msm_dp_link *msm_dp_link)
+{
+	struct device_node *of_node = dev->of_node;
+	int cnt;
+
+	/*
+	 * data-lanes is the property of msm_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)
+		msm_dp_link->max_dp_lanes = cnt;
+	else
+		msm_dp_link->max_dp_lanes = DP_MAX_NUM_DP_LANES; /* 4 lanes */
+
+	msm_dp_link->max_dp_link_rate = msm_dp_link_link_frequencies(of_node);
+	if (!msm_dp_link->max_dp_link_rate)
+		msm_dp_link->max_dp_link_rate = DP_LINK_RATE_HBR2;
+
+	return 0;
+}
+
 struct msm_dp_link *msm_dp_link_get(struct device *dev, struct drm_dp_aux *aux)
 {
 	struct msm_dp_link_private *link;
 	struct msm_dp_link *msm_dp_link;
+	int ret;
 
 	if (!dev || !aux) {
 		DRM_ERROR("invalid input\n");
@@ -1229,5 +1282,9 @@ struct msm_dp_link *msm_dp_link_get(struct device *dev, struct drm_dp_aux *aux)
 	mutex_init(&link->psm_mutex);
 	msm_dp_link = &link->msm_dp_link;
 
+	ret = msm_dp_link_parse_dt(dev, msm_dp_link);
+	if (ret)
+		return ERR_PTR(ret);
+
 	return msm_dp_link;
 }
diff --git a/drivers/gpu/drm/msm/dp/dp_link.h b/drivers/gpu/drm/msm/dp/dp_link.h
index ba47c6d19fbf..0684a962d4ec 100644
--- a/drivers/gpu/drm/msm/dp/dp_link.h
+++ b/drivers/gpu/drm/msm/dp/dp_link.h
@@ -12,6 +12,7 @@
 #define DS_PORT_STATUS_CHANGED 0x200
 #define DP_TEST_BIT_DEPTH_UNKNOWN 0xFFFFFFFF
 #define DP_LINK_CAP_ENHANCED_FRAMING (1 << 0)
+#define DP_MAX_NUM_DP_LANES    4
 
 struct msm_dp_link_info {
 	unsigned char revision;
@@ -72,6 +73,9 @@ struct msm_dp_link {
 	struct msm_dp_link_test_audio test_audio;
 	struct msm_dp_link_phy_params phy_params;
 	struct msm_dp_link_info link_params;
+
+	u32 max_dp_lanes;
+	u32 max_dp_link_rate;
 };
 
 /**
diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c b/drivers/gpu/drm/msm/dp/dp_panel.c
index 15b7f6c7146e..ad5d55bf009d 100644
--- a/drivers/gpu/drm/msm/dp/dp_panel.c
+++ b/drivers/gpu/drm/msm/dp/dp_panel.c
@@ -16,9 +16,6 @@
 
 #define DP_INTF_CONFIG_DATABUS_WIDEN     BIT(4)
 
-#define DP_MAX_NUM_DP_LANES	4
-#define DP_LINK_RATE_HBR2	540000 /* kbytes */
-
 struct msm_dp_panel_private {
 	struct device *dev;
 	struct drm_device *drm_dev;
@@ -91,6 +88,7 @@ static int msm_dp_panel_read_dpcd(struct msm_dp_panel *msm_dp_panel)
 	int rc, max_lttpr_lanes, max_lttpr_rate;
 	struct msm_dp_panel_private *panel;
 	struct msm_dp_link_info *link_info;
+	struct msm_dp_link *link;
 	u8 *dpcd, major, minor;
 
 	panel = container_of(msm_dp_panel, struct msm_dp_panel_private, msm_dp_panel);
@@ -105,16 +103,20 @@ static int msm_dp_panel_read_dpcd(struct msm_dp_panel *msm_dp_panel)
 	major = (link_info->revision >> 4) & 0x0f;
 	minor = link_info->revision & 0x0f;
 
+	link = panel->link;
+	drm_dbg_dp(panel->drm_dev, "max_lanes=%d max_link_rate=%d\n",
+		   link->max_dp_lanes, link->max_dp_link_rate);
+
 	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 > msm_dp_panel->max_dp_lanes)
-		link_info->num_lanes = msm_dp_panel->max_dp_lanes;
+	if (link_info->num_lanes > link->max_dp_lanes)
+		link_info->num_lanes = link->max_dp_lanes;
 
 	/* Limit link rate from link-frequencies of endpoint property of dtsi */
-	if (link_info->rate > msm_dp_panel->max_dp_link_rate)
-		link_info->rate = msm_dp_panel->max_dp_link_rate;
+	if (link_info->rate > link->max_dp_link_rate)
+		link_info->rate = link->max_dp_link_rate;
 
 	/* Limit data lanes from LTTPR capabilities, if any */
 	max_lttpr_lanes = drm_dp_lttpr_max_lane_count(panel->link->lttpr_common_caps);
@@ -173,9 +175,6 @@ int msm_dp_panel_read_sink_caps(struct msm_dp_panel *msm_dp_panel,
 
 	panel = container_of(msm_dp_panel, struct msm_dp_panel_private, msm_dp_panel);
 
-	drm_dbg_dp(panel->drm_dev, "max_lanes=%d max_link_rate=%d\n",
-		msm_dp_panel->max_dp_lanes, msm_dp_panel->max_dp_link_rate);
-
 	rc = msm_dp_panel_read_dpcd(msm_dp_panel);
 	if (rc) {
 		DRM_ERROR("read dpcd failed %d\n", rc);
@@ -648,60 +647,6 @@ int msm_dp_panel_init_panel_info(struct msm_dp_panel *msm_dp_panel)
 	return 0;
 }
 
-static u32 msm_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 msm_dp_panel_parse_dt(struct msm_dp_panel *msm_dp_panel)
-{
-	struct msm_dp_panel_private *panel;
-	struct device_node *of_node;
-	int cnt;
-
-	panel = container_of(msm_dp_panel, struct msm_dp_panel_private, msm_dp_panel);
-	of_node = panel->dev->of_node;
-
-	/*
-	 * data-lanes is the property of msm_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)
-		msm_dp_panel->max_dp_lanes = cnt;
-	else
-		msm_dp_panel->max_dp_lanes = DP_MAX_NUM_DP_LANES; /* 4 lanes */
-
-	msm_dp_panel->max_dp_link_rate = msm_dp_panel_link_frequencies(of_node);
-	if (!msm_dp_panel->max_dp_link_rate)
-		msm_dp_panel->max_dp_link_rate = DP_LINK_RATE_HBR2;
-
-	return 0;
-}
-
 struct msm_dp_panel *msm_dp_panel_get(struct device *dev, struct drm_dp_aux *aux,
 			      struct msm_dp_link *link,
 			      void __iomem *link_base,
@@ -709,7 +654,6 @@ struct msm_dp_panel *msm_dp_panel_get(struct device *dev, struct drm_dp_aux *aux
 {
 	struct msm_dp_panel_private *panel;
 	struct msm_dp_panel *msm_dp_panel;
-	int ret;
 
 	if (!dev || !aux || !link) {
 		DRM_ERROR("invalid input\n");
@@ -729,10 +673,6 @@ struct msm_dp_panel *msm_dp_panel_get(struct device *dev, struct drm_dp_aux *aux
 	msm_dp_panel = &panel->msm_dp_panel;
 	msm_dp_panel->max_bw_code = DP_LINK_BW_8_1;
 
-	ret = msm_dp_panel_parse_dt(msm_dp_panel);
-	if (ret)
-		return ERR_PTR(ret);
-
 	return msm_dp_panel;
 }
 
diff --git a/drivers/gpu/drm/msm/dp/dp_panel.h b/drivers/gpu/drm/msm/dp/dp_panel.h
index d2cf401506dc..921a296852d4 100644
--- a/drivers/gpu/drm/msm/dp/dp_panel.h
+++ b/drivers/gpu/drm/msm/dp/dp_panel.h
@@ -41,9 +41,6 @@ struct msm_dp_panel {
 	bool vsc_sdp_supported;
 	u32 hw_revision;
 
-	u32 max_dp_lanes;
-	u32 max_dp_link_rate;
-
 	u32 max_bw_code;
 };