drm: dw-hdmi: use cec_notifier_conn_(un)register

Use the new cec_notifier_conn_(un)register() functions to
(un)register the notifier for the HDMI connector, and fill in
the cec_connector_info.

Changes since v6:
        - move cec_notifier_conn_unregister to a bridge detach
	  function,
	- add a mutex protecting a CEC notifier.
Changes since v4:
	- typo fix
Changes since v2:
	- removed unnecessary NULL check before a call to
	cec_notifier_conn_unregister,
	- use cec_notifier_phys_addr_invalidate to invalidate physical
	address.
Changes since v1:
	Add memory barrier to make sure that the notifier
	becomes visible to the irq thread once it is fully
	constructed.

Signed-off-by: Dariusz Marcinkiewicz <darekm@google.com>
Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Tested-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190814104520.6001-9-darekm@google.com

drivers/gpu/drm/bridge/synopsys/dw-hdmi.c

@@ -190,6 +190,7 @@ struct dw_hdmi {
 	void (*enable_audio)(struct dw_hdmi *hdmi);
 	void (*disable_audio)(struct dw_hdmi *hdmi);
 
+	struct mutex cec_notifier_mutex;
 	struct cec_notifier *cec_notifier;
 };
 
@@ -2230,6 +2231,8 @@ static int dw_hdmi_bridge_attach(struct drm_bridge *bridge)
 	struct dw_hdmi *hdmi = bridge->driver_private;
 	struct drm_encoder *encoder = bridge->encoder;
 	struct drm_connector *connector = &hdmi->connector;
+	struct cec_connector_info conn_info;
+	struct cec_notifier *notifier;
 
 	connector->interlace_allowed = 1;
 	connector->polled = DRM_CONNECTOR_POLL_HPD;
@@ -2243,9 +2246,29 @@ static int dw_hdmi_bridge_attach(struct drm_bridge *bridge)
 
 	drm_connector_attach_encoder(connector, encoder);
 
+	cec_fill_conn_info_from_drm(&conn_info, connector);
+
+	notifier = cec_notifier_conn_register(hdmi->dev, NULL, &conn_info);
+	if (!notifier)
+		return -ENOMEM;
+
+	mutex_lock(&hdmi->cec_notifier_mutex);
+	hdmi->cec_notifier = notifier;
+	mutex_unlock(&hdmi->cec_notifier_mutex);
+
 	return 0;
 }
 
+static void dw_hdmi_bridge_detach(struct drm_bridge *bridge)
+{
+	struct dw_hdmi *hdmi = bridge->driver_private;
+
+	mutex_lock(&hdmi->cec_notifier_mutex);
+	cec_notifier_conn_unregister(hdmi->cec_notifier);
+	hdmi->cec_notifier = NULL;
+	mutex_unlock(&hdmi->cec_notifier_mutex);
+}
+
 static enum drm_mode_status
 dw_hdmi_bridge_mode_valid(struct drm_bridge *bridge,
 			  const struct drm_display_mode *mode)
@@ -2302,6 +2325,7 @@ static void dw_hdmi_bridge_enable(struct drm_bridge *bridge)
 
 static const struct drm_bridge_funcs dw_hdmi_bridge_funcs = {
 	.attach = dw_hdmi_bridge_attach,
+	.detach = dw_hdmi_bridge_detach,
 	.enable = dw_hdmi_bridge_enable,
 	.disable = dw_hdmi_bridge_disable,
 	.mode_set = dw_hdmi_bridge_mode_set,
@@ -2409,9 +2433,11 @@ static irqreturn_t dw_hdmi_irq(int irq, void *dev_id)
 				       phy_stat & HDMI_PHY_HPD,
 				       phy_stat & HDMI_PHY_RX_SENSE);
 
-		if ((phy_stat & (HDMI_PHY_RX_SENSE | HDMI_PHY_HPD)) == 0)
-			cec_notifier_set_phys_addr(hdmi->cec_notifier,
-						   CEC_PHYS_ADDR_INVALID);
+		if ((phy_stat & (HDMI_PHY_RX_SENSE | HDMI_PHY_HPD)) == 0) {
+			mutex_lock(&hdmi->cec_notifier_mutex);
+			cec_notifier_phys_addr_invalidate(hdmi->cec_notifier);
+			mutex_unlock(&hdmi->cec_notifier_mutex);
+		}
 	}
 
 	if (intr_stat & HDMI_IH_PHY_STAT0_HPD) {
@@ -2597,6 +2623,7 @@ __dw_hdmi_probe(struct platform_device *pdev,
 
 	mutex_init(&hdmi->mutex);
 	mutex_init(&hdmi->audio_mutex);
+	mutex_init(&hdmi->cec_notifier_mutex);
 	spin_lock_init(&hdmi->audio_lock);
 
 	ddc_node = of_parse_phandle(np, "ddc-i2c-bus", 0);
@@ -2729,12 +2756,6 @@ __dw_hdmi_probe(struct platform_device *pdev,
 	if (ret)
 		goto err_iahb;
 
-	hdmi->cec_notifier = cec_notifier_get(dev);
-	if (!hdmi->cec_notifier) {
-		ret = -ENOMEM;
-		goto err_iahb;
-	}
-
 	/*
 	 * To prevent overflows in HDMI_IH_FC_STAT2, set the clk regenerator
 	 * N and cts values before enabling phy
@@ -2833,9 +2854,6 @@ __dw_hdmi_probe(struct platform_device *pdev,
 		hdmi->ddc = NULL;
 	}
 
-	if (hdmi->cec_notifier)
-		cec_notifier_put(hdmi->cec_notifier);
-
 	clk_disable_unprepare(hdmi->iahb_clk);
 	if (hdmi->cec_clk)
 		clk_disable_unprepare(hdmi->cec_clk);
@@ -2857,9 +2875,6 @@ static void __dw_hdmi_remove(struct dw_hdmi *hdmi)
 	/* Disable all interrupts */
 	hdmi_writeb(hdmi, ~0, HDMI_IH_MUTE_PHY_STAT0);
 
-	if (hdmi->cec_notifier)
-		cec_notifier_put(hdmi->cec_notifier);
-
 	clk_disable_unprepare(hdmi->iahb_clk);
 	clk_disable_unprepare(hdmi->isfr_clk);
 	if (hdmi->cec_clk)