[PATCH v2 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[PATCH v2 1/2] drm: Add HPD state to drm_connector_oob_hotplug_event()

[Bjorn Andersson]

In some implementations, such as the Qualcomm platforms, the display
driver has no way to query the current HPD state and as such it's
impossible to distinguish between disconnect and attention events.

Add a parameter to drm_connector_oob_hotplug_event() to pass the HPD
state.

Also push the test for unchanged state in the displayport altmode driver
into the i915 driver, to allow other drivers to act upon each update.

Changes in v2:
- Replace bool with drm_connector_hpd_state enum to represent "state" better
- Track old hpd state per encoder in i915

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---
 drivers/gpu/drm/drm_connector.c          |  6 ++++--
 drivers/gpu/drm/i915/display/intel_dp.c  | 17 ++++++++++++++---
 drivers/gpu/drm/i915/i915_drv.h          |  3 +++
 drivers/usb/typec/altmodes/displayport.c | 10 +++-------
 include/drm/drm_connector.h              | 11 +++++++++--
 5 files changed, 33 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index a50c82bc2b2f..a44f082ebd9d 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -2825,6 +2825,7 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
 /**
  * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
  * @connector_fwnode: fwnode_handle to report the event on
+ * @hpd_state: hot plug detect logical state
  *
  * On some hardware a hotplug event notification may come from outside the display
  * driver / device. An example of this is some USB Type-C setups where the hardware
@@ -2834,7 +2835,8 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
  * This function can be used to report these out-of-band events after obtaining
  * a drm_connector reference through calling drm_connector_find_by_fwnode().
  */
-void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
+void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
+				     enum drm_connector_hpd_state hpd_state)
 {
 	struct drm_connector *connector;
 
@@ -2843,7 +2845,7 @@ void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
 		return;
 
 	if (connector->funcs->oob_hotplug_event)
-		connector->funcs->oob_hotplug_event(connector);
+		connector->funcs->oob_hotplug_event(connector, hpd_state);
 
 	drm_connector_put(connector);
 }
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 1046e7fe310a..a3c9dbae5cee 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -4825,15 +4825,26 @@ static int intel_dp_connector_atomic_check(struct drm_connector *conn,
 	return intel_modeset_synced_crtcs(state, conn);
 }
 
-static void intel_dp_oob_hotplug_event(struct drm_connector *connector)
+static void intel_dp_oob_hotplug_event(struct drm_connector *connector,
+				       enum drm_connector_hpd_state hpd_state)
 {
 	struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector));
 	struct drm_i915_private *i915 = to_i915(connector->dev);
+	bool hpd_high = hpd_state == DRM_CONNECTOR_HPD_HIGH;
+	unsigned int hpd_pin = encoder->hpd_pin;
+	bool need_work = false;
 
 	spin_lock_irq(&i915->irq_lock);
-	i915->hotplug.event_bits |= BIT(encoder->hpd_pin);
+	if (hpd_high != test_bit(hpd_pin, &i915->hotplug.oob_hotplug_last_state)) {
+		i915->hotplug.event_bits |= BIT(hpd_pin);
+
+		__assign_bit(hpd_pin, &i915->hotplug.oob_hotplug_last_state, hpd_high);
+		need_work = true;
+	}
 	spin_unlock_irq(&i915->irq_lock);
-	queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
+
+	if (need_work)
+		queue_delayed_work(system_wq, &i915->hotplug.hotplug_work, 0);
 }
 
 static const struct drm_connector_funcs intel_dp_connector_funcs = {
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 5cfe69b30841..80a4615a38e2 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -138,6 +138,9 @@ struct i915_hotplug {
 	/* Whether or not to count short HPD IRQs in HPD storms */
 	u8 hpd_short_storm_enabled;
 
+	/* Last state reported by oob_hotplug_event for each encoder */
+	unsigned long oob_hotplug_last_state;
+
 	/*
 	 * if we get a HPD irq from DP and a HPD irq from non-DP
 	 * the non-DP HPD could block the workqueue on a mode config
diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
index c1d8c23baa39..ea9cb1d71fd2 100644
--- a/drivers/usb/typec/altmodes/displayport.c
+++ b/drivers/usb/typec/altmodes/displayport.c
@@ -59,7 +59,6 @@ struct dp_altmode {
 	struct typec_displayport_data data;
 
 	enum dp_state state;
-	bool hpd;
 
 	struct mutex lock; /* device lock */
 	struct work_struct work;
@@ -143,10 +142,8 @@ static int dp_altmode_status_update(struct dp_altmode *dp)
 		if (!ret)
 			dp->state = DP_STATE_CONFIGURE;
 	} else {
-		if (dp->hpd != hpd) {
-			drm_connector_oob_hotplug_event(dp->connector_fwnode);
-			dp->hpd = hpd;
-		}
+		drm_connector_oob_hotplug_event(dp->connector_fwnode,
+						hpd ? DRM_CONNECTOR_HPD_HIGH : DRM_CONNECTOR_HPD_LOW);
 	}
 
 	return ret;
@@ -573,8 +570,7 @@ void dp_altmode_remove(struct typec_altmode *alt)
 	cancel_work_sync(&dp->work);
 
 	if (dp->connector_fwnode) {
-		if (dp->hpd)
-			drm_connector_oob_hotplug_event(dp->connector_fwnode);
+		drm_connector_oob_hotplug_event(dp->connector_fwnode, DRM_CONNECTOR_HPD_LOW);
 
 		fwnode_handle_put(dp->connector_fwnode);
 	}
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 64cf5f88c05b..bd2f305fa670 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -142,6 +142,11 @@ enum subpixel_order {
 
 };
 
+enum drm_connector_hpd_state {
+	DRM_CONNECTOR_HPD_LOW,
+	DRM_CONNECTOR_HPD_HIGH
+};
+
 /**
  * struct drm_scrambling: sink's scrambling support.
  */
@@ -1141,7 +1146,8 @@ struct drm_connector_funcs {
 	 * This will get called when a hotplug-event for a drm-connector
 	 * has been received from a source outside the display driver / device.
 	 */
-	void (*oob_hotplug_event)(struct drm_connector *connector);
+	void (*oob_hotplug_event)(struct drm_connector *connector,
+				  enum drm_connector_hpd_state hpd_state);
 };
 
 /**
@@ -1742,7 +1748,8 @@ drm_connector_is_unregistered(struct drm_connector *connector)
 		DRM_CONNECTOR_UNREGISTERED;
 }
 
-void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode);
+void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode,
+				     enum drm_connector_hpd_state hpd_state);
 const char *drm_get_connector_type_name(unsigned int connector_type);
 const char *drm_get_connector_status_name(enum drm_connector_status status);
 const char *drm_get_subpixel_order_name(enum subpixel_order order);
-- 
2.33.1

[PATCH v2 2/2] drm/msm/dp: Implement oob_hotplug_event()

[Bjorn Andersson]

The Qualcomm DisplayPort driver contains traces of the necessary
plumbing to hook up USB HPD, in the form of the dp_hpd module and the
dp_usbpd_cb struct. Use this as basis for implementing the
oob_hotplug_event() callback, by amending the dp_hpd module with the
missing logic.

Overall the solution is similar to what's done downstream, but upstream
all the code to disect the HPD notification lives on the calling side of
drm_connector_oob_hotplug_event().

drm_connector_oob_hotplug_event() performs the lookup of the
drm_connector based on fwnode, hence the need to assign the fwnode in
dp_drm_connector_init().

Changes in v2:
- Adopt enum drm_connector_hpd_state

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---
 drivers/gpu/drm/msm/dp/dp_display.c |  9 +++++++++
 drivers/gpu/drm/msm/dp/dp_display.h |  3 +++
 drivers/gpu/drm/msm/dp/dp_drm.c     | 11 +++++++++++
 drivers/gpu/drm/msm/dp/dp_hpd.c     | 21 +++++++++++++++++++++
 drivers/gpu/drm/msm/dp/dp_hpd.h     |  5 +++++
 5 files changed, 49 insertions(+)

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 178b774a5fbd..3d9d754a75f3 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -449,6 +449,14 @@ static int dp_display_usbpd_configure_cb(struct device *dev)
 	return dp_display_process_hpd_high(dp);
 }
 
+void dp_display_oob_hotplug_event(struct msm_dp *dp_display,
+				  enum drm_connector_hpd_state hpd_state)
+{
+	struct dp_display_private *dp = container_of(dp_display, struct dp_display_private, dp_display);
+
+	dp->usbpd->oob_event(dp->usbpd, hpd_state);
+}
+
 static int dp_display_usbpd_disconnect_cb(struct device *dev)
 {
 	struct dp_display_private *dp = dev_get_dp_display_private(dev);
@@ -1296,6 +1304,7 @@ static int dp_display_probe(struct platform_device *pdev)
 	dp->pdev = pdev;
 	dp->name = "drm_dp";
 	dp->dp_display.connector_type = desc->connector_type;
+	dp->dp_display.dev = &pdev->dev;
 
 	rc = dp_init_sub_modules(dp);
 	if (rc) {
diff --git a/drivers/gpu/drm/msm/dp/dp_display.h b/drivers/gpu/drm/msm/dp/dp_display.h
index 7af2b186d2d9..16658270df2c 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.h
+++ b/drivers/gpu/drm/msm/dp/dp_display.h
@@ -11,6 +11,7 @@
 #include "disp/msm_disp_snapshot.h"
 
 struct msm_dp {
+	struct device *dev;
 	struct drm_device *drm_dev;
 	struct device *codec_dev;
 	struct drm_bridge *bridge;
@@ -40,5 +41,7 @@ bool dp_display_check_video_test(struct msm_dp *dp_display);
 int dp_display_get_test_bpp(struct msm_dp *dp_display);
 void dp_display_signal_audio_start(struct msm_dp *dp_display);
 void dp_display_signal_audio_complete(struct msm_dp *dp_display);
+void dp_display_oob_hotplug_event(struct msm_dp *dp_display,
+				  enum drm_connector_hpd_state hpd_state);
 
 #endif /* _DP_DISPLAY_H_ */
diff --git a/drivers/gpu/drm/msm/dp/dp_drm.c b/drivers/gpu/drm/msm/dp/dp_drm.c
index 80f59cf99089..76904b1601b1 100644
--- a/drivers/gpu/drm/msm/dp/dp_drm.c
+++ b/drivers/gpu/drm/msm/dp/dp_drm.c
@@ -123,6 +123,14 @@ static enum drm_mode_status dp_connector_mode_valid(
 	return dp_display_validate_mode(dp_disp, mode->clock);
 }
 
+static void dp_oob_hotplug_event(struct drm_connector *connector,
+				 enum drm_connector_hpd_state hpd_state)
+{
+	struct msm_dp *dp_disp = to_dp_connector(connector)->dp_display;
+
+	dp_display_oob_hotplug_event(dp_disp, hpd_state);
+}
+
 static const struct drm_connector_funcs dp_connector_funcs = {
 	.detect = dp_connector_detect,
 	.fill_modes = drm_helper_probe_single_connector_modes,
@@ -130,6 +138,7 @@ static const struct drm_connector_funcs dp_connector_funcs = {
 	.reset = drm_atomic_helper_connector_reset,
 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+	.oob_hotplug_event = dp_oob_hotplug_event,
 };
 
 static const struct drm_connector_helper_funcs dp_connector_helper_funcs = {
@@ -160,6 +169,8 @@ struct drm_connector *dp_drm_connector_init(struct msm_dp *dp_display)
 	if (ret)
 		return ERR_PTR(ret);
 
+	connector->fwnode = fwnode_handle_get(dev_fwnode(dp_display->dev));
+
 	drm_connector_helper_add(connector, &dp_connector_helper_funcs);
 
 	/*
diff --git a/drivers/gpu/drm/msm/dp/dp_hpd.c b/drivers/gpu/drm/msm/dp/dp_hpd.c
index db98a1d431eb..cdb1feea5ebf 100644
--- a/drivers/gpu/drm/msm/dp/dp_hpd.c
+++ b/drivers/gpu/drm/msm/dp/dp_hpd.c
@@ -7,6 +7,8 @@
 
 #include <linux/slab.h>
 #include <linux/device.h>
+#include <drm/drm_connector.h>
+#include <drm/drm_print.h>
 
 #include "dp_hpd.h"
 
@@ -45,6 +47,24 @@ int dp_hpd_connect(struct dp_usbpd *dp_usbpd, bool hpd)
 	return rc;
 }
 
+static void dp_hpd_oob_event(struct dp_usbpd *dp_usbpd,
+			     enum drm_connector_hpd_state hpd_state)
+{
+	struct dp_hpd_private *hpd_priv = container_of(dp_usbpd, struct dp_hpd_private, dp_usbpd);
+
+	DRM_DEBUG_DP("hpd_state: %d connected: %d\n", hpd_state, dp_usbpd->connected);
+
+	if (!dp_usbpd->connected && hpd_state == DRM_CONNECTOR_HPD_HIGH) {
+		dp_usbpd->connected = true;
+		hpd_priv->dp_cb->configure(hpd_priv->dev);
+	} else if (hpd_state == DRM_CONNECTOR_HPD_LOW) {
+		dp_usbpd->connected = false;
+		hpd_priv->dp_cb->disconnect(hpd_priv->dev);
+	} else {
+		hpd_priv->dp_cb->attention(hpd_priv->dev);
+	}
+}
+
 struct dp_usbpd *dp_hpd_get(struct device *dev, struct dp_usbpd_cb *cb)
 {
 	struct dp_hpd_private *dp_hpd;
@@ -62,6 +82,7 @@ struct dp_usbpd *dp_hpd_get(struct device *dev, struct dp_usbpd_cb *cb)
 	dp_hpd->dp_cb = cb;
 
 	dp_hpd->dp_usbpd.connect = dp_hpd_connect;
+	dp_hpd->dp_usbpd.oob_event = dp_hpd_oob_event;
 
 	return &dp_hpd->dp_usbpd;
 }
diff --git a/drivers/gpu/drm/msm/dp/dp_hpd.h b/drivers/gpu/drm/msm/dp/dp_hpd.h
index 8feec5aa5027..4166e5fd3156 100644
--- a/drivers/gpu/drm/msm/dp/dp_hpd.h
+++ b/drivers/gpu/drm/msm/dp/dp_hpd.h
@@ -29,7 +29,9 @@ enum plug_orientation {
  * @hpd_irq: Change in the status since last message
  * @alt_mode_cfg_done: bool to specify alt mode status
  * @debug_en: bool to specify debug mode
+ * @connected: cable currently connected
  * @connect: simulate disconnect or connect for debug mode
+ * @oob_event: deliver oob event to the usbpd code
  */
 struct dp_usbpd {
 	enum plug_orientation orientation;
@@ -41,8 +43,11 @@ struct dp_usbpd {
 	bool hpd_irq;
 	bool alt_mode_cfg_done;
 	bool debug_en;
+	bool connected;
 
 	int (*connect)(struct dp_usbpd *dp_usbpd, bool hpd);
+	void (*oob_event)(struct dp_usbpd *dp_usbpd,
+			  enum drm_connector_hpd_state hpd_state);
 };
 
 /**
-- 
2.33.1