drm/i915/ips: Add i915_ips_false_color debugfs file

Similar to FBC let's expose an debugfs file to control
IPS false color. Enabling this provides an immediate visual
feedback on whether IPS is working or not.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230327133942.22063-2-ville.syrjala@linux.intel.comReviewed-by: Jani Nikula <jani.nikula@intel.com>

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

@@ -14,6 +14,7 @@ static void hsw_ips_enable(const struct intel_crtc_state *crtc_state)
 {
 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
 	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
+	u32 val;
 
 	if (!crtc_state->ips_enabled)
 		return;
@@ -26,10 +27,15 @@ static void hsw_ips_enable(const struct intel_crtc_state *crtc_state)
 	drm_WARN_ON(&i915->drm,
 		    !(crtc_state->active_planes & ~BIT(PLANE_CURSOR)));
 
+	val = IPS_ENABLE;
+
+	if (i915->display.ips.false_color)
+		val |= IPS_FALSE_COLOR;
+
 	if (IS_BROADWELL(i915)) {
 		drm_WARN_ON(&i915->drm,
 			    snb_pcode_write(&i915->uncore, DISPLAY_IPS_CONTROL,
-					    IPS_ENABLE | IPS_PCODE_CONTROL));
+					    val | IPS_PCODE_CONTROL));
 		/*
 		 * Quoting Art Runyan: "its not safe to expect any particular
 		 * value in IPS_CTL bit 31 after enabling IPS through the
@@ -37,7 +43,7 @@ static void hsw_ips_enable(const struct intel_crtc_state *crtc_state)
 		 * so we need to just enable it and continue on.
 		 */
 	} else {
-		intel_de_write(i915, IPS_CTL, IPS_ENABLE);
+		intel_de_write(i915, IPS_CTL, val);
 		/*
 		 * The bit only becomes 1 in the next vblank, so this wait here
 		 * is essentially intel_wait_for_vblank. If we don't have this
@@ -268,6 +274,51 @@ void hsw_ips_get_config(struct intel_crtc_state *crtc_state)
 	}
 }
 
+static int hsw_ips_debugfs_false_color_get(void *data, u64 *val)
+{
+	struct intel_crtc *crtc = data;
+	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
+
+	*val = i915->display.ips.false_color;
+
+	return 0;
+}
+
+static int hsw_ips_debugfs_false_color_set(void *data, u64 val)
+{
+	struct intel_crtc *crtc = data;
+	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
+	struct intel_crtc_state *crtc_state;
+	int ret;
+
+	ret = drm_modeset_lock(&crtc->base.mutex, NULL);
+	if (ret)
+		return ret;
+
+	i915->display.ips.false_color = val;
+
+	crtc_state = to_intel_crtc_state(crtc->base.state);
+
+	if (!crtc_state->hw.active)
+		goto unlock;
+
+	if (crtc_state->uapi.commit &&
+	    !try_wait_for_completion(&crtc_state->uapi.commit->hw_done))
+		goto unlock;
+
+	hsw_ips_enable(crtc_state);
+
+ unlock:
+	drm_modeset_unlock(&crtc->base.mutex);
+
+	return ret;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(hsw_ips_debugfs_false_color_fops,
+			 hsw_ips_debugfs_false_color_get,
+			 hsw_ips_debugfs_false_color_set,
+			 "%llu\n");
+
 static int hsw_ips_debugfs_status_show(struct seq_file *m, void *unused)
 {
 	struct intel_crtc *crtc = m->private;
@@ -300,6 +351,9 @@ void hsw_ips_crtc_debugfs_add(struct intel_crtc *crtc)
 	if (!hsw_crtc_supports_ips(crtc))
 		return;
 
+	debugfs_create_file("i915_ips_false_color", 0644, crtc->base.debugfs_entry,
+			    crtc, &hsw_ips_debugfs_false_color_fops);
+
 	debugfs_create_file("i915_ips_status", 0444, crtc->base.debugfs_entry,
 			    crtc, &hsw_ips_debugfs_status_fops);
 }

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

@@ -418,6 +418,10 @@ struct intel_display {
 		u32 state;
 	} hti;
 
+	struct {
+		bool false_color;
+	} ips;
+
 	struct {
 		struct i915_power_domains domains;
 

drivers/gpu/drm/i915/i915_reg.h

@@ -1397,7 +1397,8 @@
 #define IVB_FBC_RT_BASE_UPPER		_MMIO(0x7024)
 
 #define IPS_CTL		_MMIO(0x43408)
-#define   IPS_ENABLE	(1 << 31)
+#define   IPS_ENABLE		REG_BIT(31)
+#define   IPS_FALSE_COLOR	REG_BIT(4)
 
 #define MSG_FBC_REND_STATE(fbc_id)	_MMIO_PIPE((fbc_id), 0x50380, 0x50384)
 #define   FBC_REND_NUKE			REG_BIT(2)