drm/i915/alpm: Add debugfs for LOBF

For validation purpose add debugfs for LOBF.

v1: Initial version.
v2: Add aux-wake/less info along with lobf status. [Jouni]
Reviewed-by: Jouni Högander <jouni.hogander@intel.com>
Signed-off-by: Animesh Manna <animesh.manna@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240529200742.1694401-7-animesh.manna@intel.com

drivers/gpu/drm/i915/display/intel_alpm.c

@@ -360,3 +360,52 @@ void intel_alpm_configure(struct intel_dp *intel_dp,
 {
 	lnl_alpm_configure(intel_dp, crtc_state);
 }
+
+static int i915_edp_lobf_info_show(struct seq_file *m, void *data)
+{
+	struct intel_connector *connector = m->private;
+	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
+	struct drm_crtc *crtc;
+	struct intel_crtc_state *crtc_state;
+	enum transcoder cpu_transcoder;
+	u32 alpm_ctl;
+	int ret;
+
+	ret = drm_modeset_lock_single_interruptible(&dev_priv->drm.mode_config.connection_mutex);
+	if (ret)
+		return ret;
+
+	crtc = connector->base.state->crtc;
+	if (connector->base.status != connector_status_connected || !crtc) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	crtc_state = to_intel_crtc_state(crtc->state);
+	cpu_transcoder = crtc_state->cpu_transcoder;
+	alpm_ctl = intel_de_read(dev_priv, ALPM_CTL(dev_priv, cpu_transcoder));
+	seq_printf(m, "LOBF status: %s\n", str_enabled_disabled(alpm_ctl & ALPM_CTL_LOBF_ENABLE));
+	seq_printf(m, "Aux-wake alpm status: %s\n",
+		   str_enabled_disabled(!(alpm_ctl & ALPM_CTL_ALPM_AUX_LESS_ENABLE)));
+	seq_printf(m, "Aux-less alpm status: %s\n",
+		   str_enabled_disabled(alpm_ctl & ALPM_CTL_ALPM_AUX_LESS_ENABLE));
+out:
+	drm_modeset_unlock(&dev_priv->drm.mode_config.connection_mutex);
+
+	return ret;
+}
+
+DEFINE_SHOW_ATTRIBUTE(i915_edp_lobf_info);
+
+void intel_alpm_lobf_debugfs_add(struct intel_connector *connector)
+{
+	struct drm_i915_private *i915 = to_i915(connector->base.dev);
+	struct dentry *root = connector->base.debugfs_entry;
+
+	if (DISPLAY_VER(i915) < 20 ||
+	    connector->base.connector_type != DRM_MODE_CONNECTOR_eDP)
+		return;
+
+	debugfs_create_file("i915_edp_lobf_info", 0444, root,
+			    connector, &i915_edp_lobf_info_fops);
+}

drivers/gpu/drm/i915/display/intel_alpm.h

@@ -11,6 +11,7 @@
 struct intel_dp;
 struct intel_crtc_state;
 struct drm_connector_state;
+struct intel_connector;
 
 void intel_alpm_init_dpcd(struct intel_dp *intel_dp);
 bool intel_alpm_compute_params(struct intel_dp *intel_dp,
@@ -20,4 +21,5 @@ void intel_alpm_lobf_compute_config(struct intel_dp *intel_dp,
 				    struct drm_connector_state *conn_state);
 void intel_alpm_configure(struct intel_dp *intel_dp,
 			  const struct intel_crtc_state *crtc_state);
+void intel_alpm_lobf_debugfs_add(struct intel_connector *connector);
 #endif

drivers/gpu/drm/i915/display/intel_display_debugfs.c

@@ -13,6 +13,7 @@
 #include "i915_debugfs.h"
 #include "i915_irq.h"
 #include "i915_reg.h"
+#include "intel_alpm.h"
 #include "intel_crtc.h"
 #include "intel_de.h"
 #include "intel_crtc_state_dump.h"
@@ -1515,6 +1516,7 @@ void intel_connector_debugfs_add(struct intel_connector *connector)
 	intel_drrs_connector_debugfs_add(connector);
 	intel_pps_connector_debugfs_add(connector);
 	intel_psr_connector_debugfs_add(connector);
+	intel_alpm_lobf_debugfs_add(connector);
 
 	if (connector_type == DRM_MODE_CONNECTOR_DisplayPort ||
 	    connector_type == DRM_MODE_CONNECTOR_HDMIA ||