[PATCH 01/24] drm/amd/display: Add CACP ACE curve area debugfs for IGT validation

From: Chenyu Chen <[email protected]>

[Why]
IGT test cases for CACP need a way to validate that the ACE
(Adaptive Contrast Enhancement) curve responds to the CACP
aggression level. No interface exists to read the resulting
curve back from firmware for automated validation.

[How]
Add a read-only "cacp_ace_curve_area" debugfs node on eDP
connectors that support CACP. It issues a
DMUB_CMD__CACP_GET_ACE_CURVE_AREA command and reports the area
under the ACE PWL curve returned by firmware, which is directly
comparable across CACP levels, so IGT tests can query it per panel.

Reviewed-by: Leo Li <[email protected]>
Signed-off-by: Chenyu Chen <[email protected]>
Signed-off-by: James Lin <[email protected]>
---
 .../amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 68 +++++++++++++++++++
 1 file changed, 68 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
index c4b2fc690fd7..1a574f508b8d 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
@@ -3677,6 +3677,72 @@ DEFINE_DEBUGFS_ATTRIBUTE(ips_residency_cntl_fops, ips_residency_cntl_get,
 
 DEFINE_SHOW_ATTRIBUTE(current_backlight);
 DEFINE_SHOW_ATTRIBUTE(target_backlight);
+
+/*
+ * CACP ACE curve area. Read only.
+ * Returns the area under the ACE PWL curve computed by DMUB firmware on
+ * eDP panels that support CACP. The value is in DMU-internal units (PWL
+ * area); it is only meaningful for relative comparison between CACP
+ * levels on the same panel. Level 0 returns the linear baseline (largest).
+ *
+ * Example usage: cat /sys/kernel/debug/dri/0/eDP-1/cacp_ace_curve_area
+ */
+static int cacp_ace_curve_area_show(struct seq_file *m, void *unused)
+{
+	struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(m->private);
+	struct dc_link *link = aconnector->dc_link;
+	struct amdgpu_device *adev = drm_to_adev(aconnector->base.dev);
+	struct dc *dc;
+	union dmub_rb_cmd cmd;
+	unsigned int panel_inst = 0;
+	bool reallow_idle = false;
+	int ret = 0;
+
+	if (!link || link->type == dc_connection_none)
+		return -ENODEV;
+
+	if (!(link->connector_signal & SIGNAL_TYPE_EDP))
+		return -ENODEV;
+
+	if (!link->panel_config.cacp.cacp_supported)
+		return -EOPNOTSUPP;
+
+	dc = link->ctx->dc;
+
+	if (!dc_get_edp_link_panel_inst(dc, link, &panel_inst))
+		return -EINVAL;
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.cacp_get_ace_curve_area.header.type = DMUB_CMD__CACP;
+	cmd.cacp_get_ace_curve_area.header.sub_type = DMUB_CMD__CACP_GET_ACE_CURVE_AREA;
+	cmd.cacp_get_ace_curve_area.header.payload_bytes =
+		sizeof(cmd.cacp_get_ace_curve_area) -
+		sizeof(cmd.cacp_get_ace_curve_area.header);
+	cmd.cacp_get_ace_curve_area.data.in.panel_inst = panel_inst;
+
+	mutex_lock(&adev->dm.dc_lock);
+
+	if (dc->idle_optimizations_allowed) {
+		dc_allow_idle_optimizations(dc, false);
+		reallow_idle = true;
+	}
+
+	if (!dc_wake_and_execute_dmub_cmd(dc->ctx, &cmd,
+					  DM_DMUB_WAIT_TYPE_WAIT_WITH_REPLY) ||
+	    cmd.cacp_get_ace_curve_area.header.ret_status)
+		ret = -EIO;
+	else
+		seq_printf(m, "%u\n", cmd.cacp_get_ace_curve_area.data.out.area);
+
+	if (reallow_idle)
+		dc_allow_idle_optimizations(dc, true);
+
+	mutex_unlock(&adev->dm.dc_lock);
+
+	return ret;
+}
+DEFINE_SHOW_ATTRIBUTE(cacp_ace_curve_area);
+
 DEFINE_SHOW_ATTRIBUTE(ips_status);
 DEFINE_SHOW_ATTRIBUTE(ips_residency);
 
@@ -3877,6 +3943,8 @@ void connector_debugfs_init(struct amdgpu_dm_connector *connector)
 					&disallow_edp_enter_psr_fops);
 		debugfs_create_file("disallow_edp_enter_replay", 0644, dir, connector,
 					&disallow_edp_enter_replay_fops);
+		debugfs_create_file("cacp_ace_curve_area", 0444, dir, connector,
+				    &cacp_ace_curve_area_fops);
 	}
 
 	for (i = 0; i < ARRAY_SIZE(connector_debugfs_entries); i++) {
-- 
2.43.0