1 files changed, 96 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 91c945b6a762..10ca5117fcee 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -4793,3 +4793,99 @@ void i915_debugfs_cleanup(struct drm_minor *minor)
 		drm_debugfs_remove_files(info_list, 1, minor);
 	}
 }
+
+struct dpcd_block {
+	/* DPCD dump start address. */
+	unsigned int offset;
+	/* DPCD dump end address, inclusive. If unset, .size will be used. */
+	unsigned int end;
+	/* DPCD dump size. Used if .end is unset. If unset, defaults to 1. */
+	size_t size;
+	/* Only valid for eDP. */
+	bool edp;
+};
+
+static const struct dpcd_block i915_dpcd_debug[] = {
+	{ .offset = DP_DPCD_REV, .size = DP_RECEIVER_CAP_SIZE },
+	{ .offset = DP_PSR_SUPPORT, .end = DP_PSR_CAPS },
+	{ .offset = DP_DOWNSTREAM_PORT_0, .size = 16 },
+	{ .offset = DP_LINK_BW_SET, .end = DP_EDP_CONFIGURATION_SET },
+	{ .offset = DP_SINK_COUNT, .end = DP_ADJUST_REQUEST_LANE2_3 },
+	{ .offset = DP_SET_POWER },
+	{ .offset = DP_EDP_DPCD_REV },
+	{ .offset = DP_EDP_GENERAL_CAP_1, .end = DP_EDP_GENERAL_CAP_3 },
+	{ .offset = DP_EDP_DISPLAY_CONTROL_REGISTER, .end = DP_EDP_BACKLIGHT_FREQ_CAP_MAX_LSB },
+	{ .offset = DP_EDP_DBC_MINIMUM_BRIGHTNESS_SET, .end = DP_EDP_DBC_MAXIMUM_BRIGHTNESS_SET },
+};
+
+static int i915_dpcd_show(struct seq_file *m, void *data)
+{
+	struct drm_connector *connector = m->private;
+	struct intel_dp *intel_dp =
+		enc_to_intel_dp(&intel_attached_encoder(connector)->base);
+	uint8_t buf[16];
+	ssize_t err;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(i915_dpcd_debug); i++) {
+		const struct dpcd_block *b = &i915_dpcd_debug[i];
+		size_t size = b->end ? b->end - b->offset + 1 : (b->size ?: 1);
+
+		if (b->edp &&
+		    connector->connector_type != DRM_MODE_CONNECTOR_eDP)
+			continue;
+
+		/* low tech for now */
+		if (WARN_ON(size > sizeof(buf)))
+			continue;
+
+		err = drm_dp_dpcd_read(&intel_dp->aux, b->offset, buf, size);
+		if (err <= 0) {
+			DRM_ERROR("dpcd read (%zu bytes at %u) failed (%zd)\n",
+				  size, b->offset, err);
+			continue;
+		}
+
+		seq_printf(m, "%04x: %*ph\n", b->offset, (int) size, buf);
+	};
+
+	return 0;
+}
+
+static int i915_dpcd_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, i915_dpcd_show, inode->i_private);
+}
+
+static const struct file_operations i915_dpcd_fops = {
+	.owner = THIS_MODULE,
+	.open = i915_dpcd_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+/**
+ * i915_debugfs_connector_add - add i915 specific connector debugfs files
+ * @connector: pointer to a registered drm_connector
+ *
+ * Cleanup will be done by drm_connector_unregister() through a call to
+ * drm_debugfs_connector_remove().
+ *
+ * Returns 0 on success, negative error codes on error.
+ */
+int i915_debugfs_connector_add(struct drm_connector *connector)
+{
+	struct dentry *root = connector->debugfs_entry;
+
+	/* The connector must have been registered beforehands. */
+	if (!root)
+		return -ENODEV;
+
+	if (connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort ||
+	    connector->connector_type == DRM_MODE_CONNECTOR_eDP)
+		debugfs_create_file("i915_dpcd", S_IRUGO, root, connector,
+				    &i915_dpcd_fops);
+
+	return 0;
+}