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-rw-r--r--drivers/gpu/drm/drm_dp_helper.c77
-rw-r--r--drivers/gpu/drm/i915/display/intel_dp.c60
-rw-r--r--drivers/gpu/drm/i915/display/intel_dp.h1
-rw-r--r--drivers/gpu/drm/i915/display/intel_lspcon.c2
-rw-r--r--include/drm/drm_dp_helper.h3
5 files changed, 83 insertions, 60 deletions
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 46d88ef4f59a..9ca88e6c7882 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -433,6 +433,83 @@ static u8 drm_dp_downstream_port_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
return port_count;
}
+static int drm_dp_read_extended_dpcd_caps(struct drm_dp_aux *aux,
+ u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+ u8 dpcd_ext[6];
+ int ret;
+
+ /*
+ * Prior to DP1.3 the bit represented by
+ * DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT was reserved.
+ * If it is set DP_DPCD_REV at 0000h could be at a value less than
+ * the true capability of the panel. The only way to check is to
+ * then compare 0000h and 2200h.
+ */
+ if (!(dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
+ DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT))
+ return 0;
+
+ ret = drm_dp_dpcd_read(aux, DP_DP13_DPCD_REV, &dpcd_ext,
+ sizeof(dpcd_ext));
+ if (ret < 0)
+ return ret;
+ if (ret != sizeof(dpcd_ext))
+ return -EIO;
+
+ if (dpcd[DP_DPCD_REV] > dpcd_ext[DP_DPCD_REV]) {
+ DRM_DEBUG_KMS("%s: Extended DPCD rev less than base DPCD rev (%d > %d)\n",
+ aux->name, dpcd[DP_DPCD_REV],
+ dpcd_ext[DP_DPCD_REV]);
+ return 0;
+ }
+
+ if (!memcmp(dpcd, dpcd_ext, sizeof(dpcd_ext)))
+ return 0;
+
+ DRM_DEBUG_KMS("%s: Base DPCD: %*ph\n",
+ aux->name, DP_RECEIVER_CAP_SIZE, dpcd);
+
+ memcpy(dpcd, dpcd_ext, sizeof(dpcd_ext));
+
+ return 0;
+}
+
+/**
+ * drm_dp_read_dpcd_caps() - read DPCD caps and extended DPCD caps if
+ * available
+ * @aux: DisplayPort AUX channel
+ * @dpcd: Buffer to store the resulting DPCD in
+ *
+ * Attempts to read the base DPCD caps for @aux. Additionally, this function
+ * checks for and reads the extended DPRX caps (%DP_DP13_DPCD_REV) if
+ * present.
+ *
+ * Returns: %0 if the DPCD was read successfully, negative error code
+ * otherwise.
+ */
+int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux,
+ u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+ int ret;
+
+ ret = drm_dp_dpcd_read(aux, DP_DPCD_REV, dpcd, DP_RECEIVER_CAP_SIZE);
+ if (ret < 0)
+ return ret;
+ if (ret != DP_RECEIVER_CAP_SIZE || dpcd[DP_DPCD_REV] == 0)
+ return -EIO;
+
+ ret = drm_dp_read_extended_dpcd_caps(aux, dpcd);
+ if (ret < 0)
+ return ret;
+
+ DRM_DEBUG_KMS("%s: DPCD: %*ph\n",
+ aux->name, DP_RECEIVER_CAP_SIZE, dpcd);
+
+ return ret;
+}
+EXPORT_SYMBOL(drm_dp_read_dpcd_caps);
+
/**
* drm_dp_read_downstream_info() - read DPCD downstream port info if available
* @aux: DisplayPort AUX channel
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 0de94fc6289b..284b15f84592 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -4449,62 +4449,6 @@ intel_dp_link_down(struct intel_encoder *encoder,
}
}
-static void
-intel_dp_extended_receiver_capabilities(struct intel_dp *intel_dp)
-{
- struct drm_i915_private *i915 = dp_to_i915(intel_dp);
- u8 dpcd_ext[6];
-
- /*
- * Prior to DP1.3 the bit represented by
- * DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT was reserved.
- * if it is set DP_DPCD_REV at 0000h could be at a value less than
- * the true capability of the panel. The only way to check is to
- * then compare 0000h and 2200h.
- */
- if (!(intel_dp->dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
- DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT))
- return;
-
- if (drm_dp_dpcd_read(&intel_dp->aux, DP_DP13_DPCD_REV,
- &dpcd_ext, sizeof(dpcd_ext)) != sizeof(dpcd_ext)) {
- drm_err(&i915->drm,
- "DPCD failed read at extended capabilities\n");
- return;
- }
-
- if (intel_dp->dpcd[DP_DPCD_REV] > dpcd_ext[DP_DPCD_REV]) {
- drm_dbg_kms(&i915->drm,
- "DPCD extended DPCD rev less than base DPCD rev\n");
- return;
- }
-
- if (!memcmp(intel_dp->dpcd, dpcd_ext, sizeof(dpcd_ext)))
- return;
-
- drm_dbg_kms(&i915->drm, "Base DPCD: %*ph\n",
- (int)sizeof(intel_dp->dpcd), intel_dp->dpcd);
-
- memcpy(intel_dp->dpcd, dpcd_ext, sizeof(dpcd_ext));
-}
-
-bool
-intel_dp_read_dpcd(struct intel_dp *intel_dp)
-{
- struct drm_i915_private *i915 = dp_to_i915(intel_dp);
-
- if (drm_dp_dpcd_read(&intel_dp->aux, 0x000, intel_dp->dpcd,
- sizeof(intel_dp->dpcd)) < 0)
- return false; /* aux transfer failed */
-
- intel_dp_extended_receiver_capabilities(intel_dp);
-
- drm_dbg_kms(&i915->drm, "DPCD: %*ph\n", (int)sizeof(intel_dp->dpcd),
- intel_dp->dpcd);
-
- return intel_dp->dpcd[DP_DPCD_REV] != 0;
-}
-
bool intel_dp_get_colorimetry_status(struct intel_dp *intel_dp)
{
u8 dprx = 0;
@@ -4563,7 +4507,7 @@ intel_edp_init_dpcd(struct intel_dp *intel_dp)
/* this function is meant to be called only once */
drm_WARN_ON(&dev_priv->drm, intel_dp->dpcd[DP_DPCD_REV] != 0);
- if (!intel_dp_read_dpcd(intel_dp))
+ if (drm_dp_read_dpcd_caps(&intel_dp->aux, intel_dp->dpcd) != 0)
return false;
drm_dp_read_desc(&intel_dp->aux, &intel_dp->desc,
@@ -4650,7 +4594,7 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
{
int ret;
- if (!intel_dp_read_dpcd(intel_dp))
+ if (drm_dp_read_dpcd_caps(&intel_dp->aux, intel_dp->dpcd))
return false;
/*
diff --git a/drivers/gpu/drm/i915/display/intel_dp.h b/drivers/gpu/drm/i915/display/intel_dp.h
index b901ab850cbd..0a3af3410d52 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.h
+++ b/drivers/gpu/drm/i915/display/intel_dp.h
@@ -99,7 +99,6 @@ bool intel_dp_source_supports_hbr3(struct intel_dp *intel_dp);
bool
intel_dp_get_link_status(struct intel_dp *intel_dp, u8 *link_status);
-bool intel_dp_read_dpcd(struct intel_dp *intel_dp);
bool intel_dp_get_colorimetry_status(struct intel_dp *intel_dp);
int intel_dp_link_required(int pixel_clock, int bpp);
int intel_dp_max_data_rate(int max_link_clock, int max_lanes);
diff --git a/drivers/gpu/drm/i915/display/intel_lspcon.c b/drivers/gpu/drm/i915/display/intel_lspcon.c
index b781bf469644..dc1b35559afd 100644
--- a/drivers/gpu/drm/i915/display/intel_lspcon.c
+++ b/drivers/gpu/drm/i915/display/intel_lspcon.c
@@ -571,7 +571,7 @@ bool lspcon_init(struct intel_digital_port *dig_port)
return false;
}
- if (!intel_dp_read_dpcd(dp)) {
+ if (drm_dp_read_dpcd_caps(&dp->aux, dp->dpcd) != 0) {
DRM_ERROR("LSPCON DPCD read failed\n");
return false;
}
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index bc5cb8c503fb..85513eeb2196 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1607,6 +1607,9 @@ static inline ssize_t drm_dp_dpcd_writeb(struct drm_dp_aux *aux,
return drm_dp_dpcd_write(aux, offset, &value, 1);
}
+int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux,
+ u8 dpcd[DP_RECEIVER_CAP_SIZE]);
+
int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
u8 status[DP_LINK_STATUS_SIZE]);