From 4d6affab8efe7be115fa4ea5348aa5ebf9348d31 Mon Sep 17 00:00:00 2001
From: Maxime Ripard <maxime@cerno.tech>
Date: Thu, 29 Apr 2021 11:08:52 +0200
Subject: [PATCH 467/552] drm/vc4: hdmi: Rely on interrupts to handle hotplug

DRM currently polls for the HDMI connector status every 10s, which can
be an issue when we connect/disconnect a display quickly or the device
on the other end only issues a hotplug pulse (for example on EDID
change).

Switch the driver to rely on the internal controller logic for the
BCM2711/RPi4.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 drivers/gpu/drm/vc4/vc4_crtc.c |  8 +++---
 drivers/gpu/drm/vc4/vc4_drv.h  |  5 ++++
 drivers/gpu/drm/vc4/vc4_hdmi.c | 45 ++++++++++++++++++++++++++++++++++
 3 files changed, 54 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c
index c146a3fb1825..9ad2542c234b 100644
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -279,10 +279,10 @@ static u32 vc4_crtc_get_fifo_full_level_bits(struct vc4_crtc *vc4_crtc,
  * allows drivers to push pixels to more than one encoder from the
  * same CRTC.
  */
-static struct drm_encoder *vc4_get_crtc_encoder(struct drm_crtc *crtc,
-						struct drm_atomic_state *state,
-						struct drm_connector_state *(*get_state)(struct drm_atomic_state *state,
-											 struct drm_connector *connector))
+struct drm_encoder *vc4_get_crtc_encoder(struct drm_crtc *crtc,
+					 struct drm_atomic_state *state,
+					 struct drm_connector_state *(*get_state)(struct drm_atomic_state *state,
+										  struct drm_connector *connector))
 {
 	struct drm_connector *connector;
 	struct drm_connector_list_iter conn_iter;
diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
index 5dceadc61600..d3e5238eadb5 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.h
+++ b/drivers/gpu/drm/vc4/vc4_drv.h
@@ -515,6 +515,11 @@ vc4_crtc_to_vc4_pv_data(const struct vc4_crtc *crtc)
 	return container_of(data, struct vc4_pv_data, base);
 }
 
+struct drm_encoder *vc4_get_crtc_encoder(struct drm_crtc *crtc,
+					 struct drm_atomic_state *state,
+					 struct drm_connector_state *(*get_state)(struct drm_atomic_state *state,
+										  struct drm_connector *connector));
+
 struct vc4_crtc_state {
 	struct drm_crtc_state base;
 	/* Dlist area for this CRTC configuration. */
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 461f051397c9..ed59344c1804 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -2157,6 +2157,47 @@ static int vc4_hdmi_audio_init(struct vc4_hdmi *vc4_hdmi)
 
 }
 
+static irqreturn_t vc4_hdmi_hpd_irq_thread(int irq, void *priv)
+{
+	struct vc4_hdmi *vc4_hdmi = priv;
+	struct drm_device *dev = vc4_hdmi->connector.dev;
+
+	if (dev)
+		drm_kms_helper_hotplug_event(dev);
+
+	return IRQ_HANDLED;
+}
+
+static int vc4_hdmi_hotplug_init(struct vc4_hdmi *vc4_hdmi)
+{
+	struct platform_device *pdev = vc4_hdmi->pdev;
+	struct device *dev = &pdev->dev;
+	struct drm_connector *connector = &vc4_hdmi->connector;
+	int ret;
+
+	if (vc4_hdmi->variant->external_irq_controller) {
+		ret = devm_request_threaded_irq(dev,
+						platform_get_irq_byname(pdev, "hpd-connected"),
+						NULL,
+						vc4_hdmi_hpd_irq_thread, IRQF_ONESHOT,
+						"vc4 hdmi hpd connected", vc4_hdmi);
+		if (ret)
+			return ret;
+
+		ret = devm_request_threaded_irq(dev,
+						platform_get_irq_byname(pdev, "hpd-removed"),
+						NULL,
+						vc4_hdmi_hpd_irq_thread, IRQF_ONESHOT,
+						"vc4 hdmi hpd disconnected", vc4_hdmi);
+		if (ret)
+			return ret;
+
+		connector->polled = DRM_CONNECTOR_POLL_HPD;
+	}
+
+	return 0;
+}
+
 #ifdef CONFIG_DRM_VC4_HDMI_CEC
 static irqreturn_t vc4_cec_irq_handler_rx_thread(int irq, void *priv)
 {
@@ -2788,6 +2829,10 @@ static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data)
 	if (ret)
 		goto err_destroy_encoder;
 
+	ret = vc4_hdmi_hotplug_init(vc4_hdmi);
+	if (ret)
+		goto err_destroy_conn;
+
 	ret = vc4_hdmi_cec_init(vc4_hdmi);
 	if (ret)
 		goto err_destroy_conn;
-- 
2.33.0