[PATCH 0/4] video/exynos/cec: add HDMI state notifier & use in s5p-cec

[PATCH 0/4] video/exynos/cec: add HDMI state notifier & use in s5p-cec

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

This patch series adds the HDMI notifier code, based on Russell's code:

https://patchwork.kernel.org/patch/9277043/

It adds support for it to the exynos_hdmi drm driver, adds support for
it to the CEC framework and finally adds support to the s5p-cec driver,
which now can be moved out of staging.

Tested with my Odroid U3 exynos4 devboard.

Comments are welcome. I'd like to get this in for the 4.11 kernel as
this is a missing piece needed to integrate CEC drivers.

Benjamin, can you look at doing the same notifier integration for your
st-cec driver as is done for s5p-cec? It would be good to be able to
move st-cec out of staging at the same time.

Regards,

	Hans

Hans Verkuil (4):
  video: add HDMI state notifier support
  exynos_hdmi: add HDMI notifier support
  cec: integrate HDMI notifier support
  s5p-cec: add hdmi-notifier support, move out of staging

 .../devicetree/bindings/media/s5p-cec.txt          |   2 +
 arch/arm/boot/dts/exynos4.dtsi                     |   1 +
 drivers/gpu/drm/exynos/Kconfig                     |   1 +
 drivers/gpu/drm/exynos/exynos_hdmi.c               |  24 +++-
 drivers/media/cec/cec-core.c                       |  50 ++++++++
 drivers/media/platform/Kconfig                     |  18 +++
 drivers/media/platform/Makefile                    |   1 +
 .../media => media/platform}/s5p-cec/Makefile      |   0
 .../platform}/s5p-cec/exynos_hdmi_cec.h            |   0
 .../platform}/s5p-cec/exynos_hdmi_cecctrl.c        |   0
 .../media => media/platform}/s5p-cec/regs-cec.h    |   0
 .../media => media/platform}/s5p-cec/s5p_cec.c     |  35 +++++-
 .../media => media/platform}/s5p-cec/s5p_cec.h     |   3 +
 drivers/staging/media/Kconfig                      |   2 -
 drivers/staging/media/Makefile                     |   1 -
 drivers/staging/media/s5p-cec/Kconfig              |   9 --
 drivers/staging/media/s5p-cec/TODO                 |   7 --
 drivers/video/Kconfig                              |   3 +
 drivers/video/Makefile                             |   1 +
 drivers/video/hdmi-notifier.c                      | 134 +++++++++++++++++++++
 include/linux/hdmi-notifier.h                      | 109 +++++++++++++++++
 include/media/cec.h                                |  15 +++
 22 files changed, 389 insertions(+), 27 deletions(-)
 rename drivers/{staging/media => media/platform}/s5p-cec/Makefile (100%)
 rename drivers/{staging/media => media/platform}/s5p-cec/exynos_hdmi_cec.h (100%)
 rename drivers/{staging/media => media/platform}/s5p-cec/exynos_hdmi_cecctrl.c (100%)
 rename drivers/{staging/media => media/platform}/s5p-cec/regs-cec.h (100%)
 rename drivers/{staging/media => media/platform}/s5p-cec/s5p_cec.c (89%)
 rename drivers/{staging/media => media/platform}/s5p-cec/s5p_cec.h (97%)
 delete mode 100644 drivers/staging/media/s5p-cec/Kconfig
 delete mode 100644 drivers/staging/media/s5p-cec/TODO
 create mode 100644 drivers/video/hdmi-notifier.c
 create mode 100644 include/linux/hdmi-notifier.h

-- 
2.10.2

[PATCH 1/4] video: add HDMI state notifier support

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Add support for HDMI hotplug and EDID notifiers, which is used to convey
information from HDMI drivers to their CEC and audio counterparts.

Based on an earlier version from Russell King:

https://patchwork.kernel.org/patch/9277043/

The hdmi_notifier is a reference counted object containing the HDMI state
of an HDMI device.

When a new notifier is registered the current state will be reported to
that notifier at registration time.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/video/Kconfig         |   3 +
 drivers/video/Makefile        |   1 +
 drivers/video/hdmi-notifier.c | 134 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/hdmi-notifier.h | 109 ++++++++++++++++++++++++++++++++++
 4 files changed, 247 insertions(+)
 create mode 100644 drivers/video/hdmi-notifier.c
 create mode 100644 include/linux/hdmi-notifier.h

diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 3c20af9..1ee7b9f 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -36,6 +36,9 @@ config VIDEOMODE_HELPERS
 config HDMI
 	bool
 
+config HDMI_NOTIFIERS
+	bool
+
 if VT
 	source "drivers/video/console/Kconfig"
 endif
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index 9ad3c17..65f5649 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -1,5 +1,6 @@
 obj-$(CONFIG_VGASTATE)            += vgastate.o
 obj-$(CONFIG_HDMI)                += hdmi.o
+obj-$(CONFIG_HDMI_NOTIFIERS)      += hdmi-notifier.o
 
 obj-$(CONFIG_VT)		  += console/
 obj-$(CONFIG_LOGO)		  += logo/
diff --git a/drivers/video/hdmi-notifier.c b/drivers/video/hdmi-notifier.c
new file mode 100644
index 0000000..29e4225
--- /dev/null
+++ b/drivers/video/hdmi-notifier.c
@@ -0,0 +1,134 @@
+#include <linux/export.h>
+#include <linux/hdmi-notifier.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+
+static LIST_HEAD(hdmi_notifiers);
+static DEFINE_MUTEX(hdmi_notifiers_lock);
+
+struct hdmi_notifier *hdmi_notifier_get(struct device *dev)
+{
+	struct hdmi_notifier *n;
+
+	mutex_lock(&hdmi_notifiers_lock);
+	list_for_each_entry(n, &hdmi_notifiers, head) {
+		if (n->dev == dev) {
+			mutex_unlock(&hdmi_notifiers_lock);
+			kref_get(&n->kref);
+			return n;
+		}
+	}
+	n = kzalloc(sizeof(*n), GFP_KERNEL);
+	if (!n)
+		goto unlock;
+	n->dev = dev;
+	mutex_init(&n->lock);
+	BLOCKING_INIT_NOTIFIER_HEAD(&n->notifiers);
+	kref_init(&n->kref);
+	list_add_tail(&n->head, &hdmi_notifiers);
+unlock:
+	mutex_unlock(&hdmi_notifiers_lock);
+	return n;
+}
+EXPORT_SYMBOL_GPL(hdmi_notifier_get);
+
+static void hdmi_notifier_release(struct kref *kref)
+{
+	struct hdmi_notifier *n =
+		container_of(kref, struct hdmi_notifier, kref);
+
+	mutex_lock(&hdmi_notifiers_lock);
+	list_del(&n->head);
+	mutex_unlock(&hdmi_notifiers_lock);
+	kfree(n->edid);
+	kfree(n);
+}
+
+void hdmi_notifier_put(struct hdmi_notifier *n)
+{
+	kref_put(&n->kref, hdmi_notifier_release);
+}
+EXPORT_SYMBOL_GPL(hdmi_notifier_put);
+
+int hdmi_notifier_register(struct hdmi_notifier *n, struct notifier_block *nb)
+{
+	int ret = blocking_notifier_chain_register(&n->notifiers, nb);
+
+	if (ret)
+		return ret;
+	kref_get(&n->kref);
+	mutex_lock(&n->lock);
+	if (n->connected) {
+		blocking_notifier_call_chain(&n->notifiers, HDMI_CONNECTED, n);
+		if (n->edid_size)
+			blocking_notifier_call_chain(&n->notifiers, HDMI_NEW_EDID, n);
+		if (n->has_eld)
+			blocking_notifier_call_chain(&n->notifiers, HDMI_NEW_ELD, n);
+	}
+	mutex_unlock(&n->lock);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hdmi_notifier_register);
+
+int hdmi_notifier_unregister(struct hdmi_notifier *n, struct notifier_block *nb)
+{
+	int ret = blocking_notifier_chain_unregister(&n->notifiers, nb);
+
+	if (ret == 0)
+		hdmi_notifier_put(n);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(hdmi_notifier_unregister);
+
+void hdmi_event_connect(struct hdmi_notifier *n)
+{
+	mutex_lock(&n->lock);
+	n->connected = true;
+	blocking_notifier_call_chain(&n->notifiers, HDMI_CONNECTED, n);
+	mutex_unlock(&n->lock);
+}
+EXPORT_SYMBOL_GPL(hdmi_event_connect);
+
+void hdmi_event_disconnect(struct hdmi_notifier *n)
+{
+	mutex_lock(&n->lock);
+	n->connected = false;
+	n->has_eld = false;
+	n->edid_size = 0;
+	blocking_notifier_call_chain(&n->notifiers, HDMI_DISCONNECTED, n);
+	mutex_unlock(&n->lock);
+}
+EXPORT_SYMBOL_GPL(hdmi_event_disconnect);
+
+int hdmi_event_new_edid(struct hdmi_notifier *n, const void *edid, size_t size)
+{
+	mutex_lock(&n->lock);
+	if (n->edid_allocated_size < size) {
+		void *p = kmalloc(size, GFP_KERNEL);
+
+		if (p == NULL) {
+			mutex_unlock(&n->lock);
+			return -ENOMEM;
+		}
+		kfree(n->edid);
+		n->edid = p;
+		n->edid_allocated_size = size;
+	}
+	memcpy(n->edid, edid, size);
+	n->edid_size = size;
+	blocking_notifier_call_chain(&n->notifiers, HDMI_NEW_EDID, n);
+	mutex_unlock(&n->lock);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hdmi_event_new_edid);
+
+void hdmi_event_new_eld(struct hdmi_notifier *n, const u8 eld[128])
+{
+	mutex_lock(&n->lock);
+	memcpy(n->eld, eld, sizeof(n->eld));
+	n->has_eld = true;
+	blocking_notifier_call_chain(&n->notifiers, HDMI_NEW_ELD, n);
+	mutex_unlock(&n->lock);
+}
+EXPORT_SYMBOL_GPL(hdmi_event_new_eld);
diff --git a/include/linux/hdmi-notifier.h b/include/linux/hdmi-notifier.h
new file mode 100644
index 0000000..1d88db0
--- /dev/null
+++ b/include/linux/hdmi-notifier.h
@@ -0,0 +1,109 @@
+/*
+ * hdmi-notifier.h - notify interested parties of (dis)connect and EDID
+ * events
+ *
+ * Copyright 2016 Russell King <rmk+kernel@arm.linux.org.uk>
+ * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
+ */
+
+#ifndef LINUX_HDMI_NOTIFIER_H
+#define LINUX_HDMI_NOTIFIER_H
+
+#include <linux/types.h>
+#include <linux/notifier.h>
+#include <linux/kref.h>
+
+enum {
+	HDMI_CONNECTED,
+	HDMI_DISCONNECTED,
+	HDMI_NEW_EDID,
+	HDMI_NEW_ELD,
+};
+
+struct device;
+
+struct hdmi_notifier {
+	struct mutex lock;
+	struct list_head head;
+	struct kref kref;
+	struct blocking_notifier_head notifiers;
+	struct device *dev;
+
+	/* Current state */
+	bool connected;
+	bool has_eld;
+	unsigned char eld[128];
+	void *edid;
+	size_t edid_size;
+	size_t edid_allocated_size;
+};
+
+/**
+ * hdmi_notifier_get - find or create a new hdmi_notifier for the given device.
+ * @dev: device that sends the events.
+ *
+ * If a notifier for device @dev already exists, then increase the refcount
+ * and return that notifier.
+ *
+ * If it doesn't exist, then allocate a new notifier struct and return a
+ * pointer to that new struct.
+ *
+ * Return NULL if the memory could not be allocated.
+ */
+struct hdmi_notifier *hdmi_notifier_get(struct device *dev);
+
+/**
+ * hdmi_notifier_put - decrease refcount and delete when the refcount reaches 0.
+ * @n: notifier
+ */
+void hdmi_notifier_put(struct hdmi_notifier *n);
+
+/**
+ * hdmi_notifier_register - register the notifier with the notifier_block.
+ * @n: the HDMI notifier
+ * @nb: the notifier_block
+ */
+int hdmi_notifier_register(struct hdmi_notifier *n, struct notifier_block *nb);
+
+/**
+ * hdmi_notifier_unregister - unregister the notifier with the notifier_block.
+ * @n: the HDMI notifier
+ * @nb: the notifier_block
+ */
+int hdmi_notifier_unregister(struct hdmi_notifier *n, struct notifier_block *nb);
+
+/**
+ * hdmi_event_connect - send a connect event.
+ * @n: the HDMI notifier
+ *
+ * Send an HDMI_CONNECTED event to any registered parties.
+ */
+void hdmi_event_connect(struct hdmi_notifier *n);
+
+/**
+ * hdmi_event_disconnect - send a disconnect event.
+ * @n: the HDMI notifier
+ *
+ * Send an HDMI_DISCONNECTED event to any registered parties.
+ */
+void hdmi_event_disconnect(struct hdmi_notifier *n);
+
+/**
+ * hdmi_event_new_edid - send a new EDID event.
+ * @n: the HDMI notifier
+ *
+ * Send an HDMI_NEW_EDID event to any registered parties.
+ * This function will make a copy the EDID so it can return -ENOMEM if
+ * no memory could be allocated.
+ */
+int hdmi_event_new_edid(struct hdmi_notifier *n, const void *edid, size_t size);
+
+/**
+ * hdmi_event_new_eld - send a new ELD event.
+ * @n: the HDMI notifier
+ *
+ * Send an HDMI_NEW_ELD event to any registered parties.
+ */
+void hdmi_event_new_eld(struct hdmi_notifier *n, const u8 eld[128]);
+
+#endif
-- 
2.10.2

[PATCH 2/4] exynos_hdmi: add HDMI notifier support

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Implement the HDMI notifier support to allow CEC drivers to
be informed when there is a new EDID and when a connect or
disconnect happens.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/gpu/drm/exynos/Kconfig       |  1 +
 drivers/gpu/drm/exynos/exynos_hdmi.c | 24 +++++++++++++++++++++---
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/exynos/Kconfig b/drivers/gpu/drm/exynos/Kconfig
index 465d344f..34f3b6f 100644
--- a/drivers/gpu/drm/exynos/Kconfig
+++ b/drivers/gpu/drm/exynos/Kconfig
@@ -77,6 +77,7 @@ config DRM_EXYNOS_DP
 config DRM_EXYNOS_HDMI
 	bool "HDMI"
 	depends on DRM_EXYNOS_MIXER || DRM_EXYNOS5433_DECON
+	select HDMI_NOTIFIERS
 	help
 	  Choose this option if you want to use Exynos HDMI for DRM.
 
diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c b/drivers/gpu/drm/exynos/exynos_hdmi.c
index e8fb6ef..2bfc411 100644
--- a/drivers/gpu/drm/exynos/exynos_hdmi.c
+++ b/drivers/gpu/drm/exynos/exynos_hdmi.c
@@ -31,6 +31,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/clk.h>
 #include <linux/gpio/consumer.h>
+#include <linux/hdmi-notifier.h>
 #include <linux/regulator/consumer.h>
 #include <linux/io.h>
 #include <linux/of_address.h>
@@ -132,6 +133,7 @@ struct hdmi_context {
 	struct delayed_work		hotplug_work;
 	struct drm_display_mode		current_mode;
 	u8				cea_video_id;
+	struct hdmi_notifier		*notifier;
 	const struct hdmi_driver_data	*drv_data;
 
 	void __iomem			*regs;
@@ -857,9 +859,12 @@ static enum drm_connector_status hdmi_detect(struct drm_connector *connector,
 {
 	struct hdmi_context *hdata = connector_to_hdmi(connector);
 
-	if (gpiod_get_value(hdata->hpd_gpio))
+	if (gpiod_get_value(hdata->hpd_gpio)) {
+		hdmi_event_connect(hdata->notifier);
 		return connector_status_connected;
+	}
 
+	hdmi_event_disconnect(hdata->notifier);
 	return connector_status_disconnected;
 }
 
@@ -898,6 +903,9 @@ static int hdmi_get_modes(struct drm_connector *connector)
 		edid->width_cm, edid->height_cm);
 
 	drm_mode_connector_update_edid_property(connector, edid);
+	hdmi_event_connect(hdata->notifier);
+	hdmi_event_new_edid(hdata->notifier, edid,
+			    EDID_LENGTH * (1 + edid->extensions));
 
 	ret = drm_add_edid_modes(connector, edid);
 
@@ -1544,6 +1552,7 @@ static void hdmi_disable(struct drm_encoder *encoder)
 	if (funcs && funcs->disable)
 		(*funcs->disable)(crtc);
 
+	hdmi_event_disconnect(hdata->notifier);
 	cancel_delayed_work(&hdata->hotplug_work);
 
 	hdmiphy_disable(hdata);
@@ -1893,15 +1902,22 @@ static int hdmi_probe(struct platform_device *pdev)
 		}
 	}
 
+	hdata->notifier = hdmi_notifier_get(&pdev->dev);
+	if (hdata->notifier == NULL) {
+		ret = -ENOMEM;
+		goto err_hdmiphy;
+	}
+
 	pm_runtime_enable(dev);
 
 	ret = component_add(&pdev->dev, &hdmi_component_ops);
 	if (ret)
-		goto err_disable_pm_runtime;
+		goto err_notifier_put;
 
 	return ret;
 
-err_disable_pm_runtime:
+err_notifier_put:
+	hdmi_notifier_put(hdata->notifier);
 	pm_runtime_disable(dev);
 
 err_hdmiphy:
@@ -1918,9 +1934,11 @@ static int hdmi_remove(struct platform_device *pdev)
 	struct hdmi_context *hdata = platform_get_drvdata(pdev);
 
 	cancel_delayed_work_sync(&hdata->hotplug_work);
+	hdmi_event_disconnect(hdata->notifier);
 
 	component_del(&pdev->dev, &hdmi_component_ops);
 
+	hdmi_notifier_put(hdata->notifier);
 	pm_runtime_disable(&pdev->dev);
 
 	if (!IS_ERR(hdata->reg_hdmi_en))
-- 
2.10.2

[PATCH 3/4] cec: integrate HDMI notifier support

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Support the HDMI notifier framework, simplifying drivers that
depend on this.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/cec/cec-core.c | 50 ++++++++++++++++++++++++++++++++++++++++++++
 include/media/cec.h          | 15 +++++++++++++
 2 files changed, 65 insertions(+)

diff --git a/drivers/media/cec/cec-core.c b/drivers/media/cec/cec-core.c
index aca3ab8..c620a4c 100644
--- a/drivers/media/cec/cec-core.c
+++ b/drivers/media/cec/cec-core.c
@@ -195,6 +195,52 @@ static void cec_devnode_unregister(struct cec_devnode *devnode)
 	put_device(&devnode->dev);
 }
 
+#ifdef CONFIG_HDMI_NOTIFIERS
+static u16 parse_hdmi_addr(const struct edid *edid)
+{
+	if (!edid || edid->extensions == 0)
+		return CEC_PHYS_ADDR_INVALID;
+
+	return cec_get_edid_phys_addr((u8 *)edid,
+				EDID_LENGTH * (edid->extensions + 1), NULL);
+}
+
+static int cec_hdmi_notify(struct notifier_block *nb, unsigned long event,
+			   void *data)
+{
+	struct cec_adapter *adap = container_of(nb, struct cec_adapter, nb);
+	struct hdmi_notifier *n = data;
+	unsigned int phys;
+
+	dprintk(1, "event %lu\n", event);
+
+	switch (event) {
+	case HDMI_DISCONNECTED:
+		cec_s_phys_addr(adap, CEC_PHYS_ADDR_INVALID, false);
+		break;
+
+	case HDMI_NEW_EDID:
+		phys = parse_hdmi_addr(n->edid);
+		cec_s_phys_addr(adap, phys, false);
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+void cec_register_hdmi_notifier(struct cec_adapter *adap,
+				struct hdmi_notifier *notifier)
+{
+	if (WARN_ON(!adap->devnode.registered))
+		return;
+
+	adap->nb.notifier_call = cec_hdmi_notify;
+	adap->notifier = notifier;
+	hdmi_notifier_register(adap->notifier, &adap->nb);
+}
+EXPORT_SYMBOL_GPL(cec_register_hdmi_notifier);
+#endif
+
 struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops,
 					 void *priv, const char *name, u32 caps,
 					 u8 available_las)
@@ -344,6 +390,10 @@ void cec_unregister_adapter(struct cec_adapter *adap)
 	adap->rc = NULL;
 #endif
 	debugfs_remove_recursive(adap->cec_dir);
+#ifdef CONFIG_HDMI_NOTIFIERS
+	if (adap->notifier)
+		hdmi_notifier_unregister(adap->notifier, &adap->nb);
+#endif
 	cec_devnode_unregister(&adap->devnode);
 }
 EXPORT_SYMBOL_GPL(cec_unregister_adapter);
diff --git a/include/media/cec.h b/include/media/cec.h
index 96a0aa7..3b4860d 100644
--- a/include/media/cec.h
+++ b/include/media/cec.h
@@ -28,6 +28,11 @@
 #include <linux/kthread.h>
 #include <linux/timer.h>
 #include <linux/cec-funcs.h>
+#ifdef CONFIG_HDMI_NOTIFIERS
+#include <linux/notifier.h>
+#include <linux/hdmi-notifier.h>
+#include <drm/drm_edid.h>
+#endif
 #include <media/rc-core.h>
 #include <media/cec-edid.h>
 
@@ -173,6 +178,11 @@ struct cec_adapter {
 	bool passthrough;
 	struct cec_log_addrs log_addrs;
 
+#ifdef CONFIG_HDMI_NOTIFIERS
+	struct hdmi_notifier	*notifier;
+	struct notifier_block	nb;
+#endif
+
 	struct dentry *cec_dir;
 	struct dentry *status_file;
 
@@ -213,6 +223,11 @@ void cec_transmit_done(struct cec_adapter *adap, u8 status, u8 arb_lost_cnt,
 		       u8 nack_cnt, u8 low_drive_cnt, u8 error_cnt);
 void cec_received_msg(struct cec_adapter *adap, struct cec_msg *msg);
 
+#ifdef CONFIG_HDMI_NOTIFIERS
+void cec_register_hdmi_notifier(struct cec_adapter *adap,
+				struct hdmi_notifier *notifier);
+#endif
+
 #else
 
 static inline int cec_register_adapter(struct cec_adapter *adap,
-- 
2.10.2

[PATCH 4/4] s5p-cec: add hdmi-notifier support, move out of staging

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

By using the HDMI notifier framework there is no longer any reason
to manually set the physical address. This was the one blocking
issue that prevented this driver from going out of staging, so do
this move as well.

Update the bindings documenting the new hdmi phandle and
update exynos4.dtsi accordingly.

Tested with my Odroid U3.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 .../devicetree/bindings/media/s5p-cec.txt          |  2 ++
 arch/arm/boot/dts/exynos4.dtsi                     |  1 +
 drivers/media/platform/Kconfig                     | 18 +++++++++++
 drivers/media/platform/Makefile                    |  1 +
 .../media => media/platform}/s5p-cec/Makefile      |  0
 .../platform}/s5p-cec/exynos_hdmi_cec.h            |  0
 .../platform}/s5p-cec/exynos_hdmi_cecctrl.c        |  0
 .../media => media/platform}/s5p-cec/regs-cec.h    |  0
 .../media => media/platform}/s5p-cec/s5p_cec.c     | 35 ++++++++++++++++++----
 .../media => media/platform}/s5p-cec/s5p_cec.h     |  3 ++
 drivers/staging/media/Kconfig                      |  2 --
 drivers/staging/media/Makefile                     |  1 -
 drivers/staging/media/s5p-cec/Kconfig              |  9 ------
 drivers/staging/media/s5p-cec/TODO                 |  7 -----
 14 files changed, 55 insertions(+), 24 deletions(-)
 rename drivers/{staging/media => media/platform}/s5p-cec/Makefile (100%)
 rename drivers/{staging/media => media/platform}/s5p-cec/exynos_hdmi_cec.h (100%)
 rename drivers/{staging/media => media/platform}/s5p-cec/exynos_hdmi_cecctrl.c (100%)
 rename drivers/{staging/media => media/platform}/s5p-cec/regs-cec.h (100%)
 rename drivers/{staging/media => media/platform}/s5p-cec/s5p_cec.c (89%)
 rename drivers/{staging/media => media/platform}/s5p-cec/s5p_cec.h (97%)
 delete mode 100644 drivers/staging/media/s5p-cec/Kconfig
 delete mode 100644 drivers/staging/media/s5p-cec/TODO

diff --git a/Documentation/devicetree/bindings/media/s5p-cec.txt b/Documentation/devicetree/bindings/media/s5p-cec.txt
index 925ab4d..710fc00 100644
--- a/Documentation/devicetree/bindings/media/s5p-cec.txt
+++ b/Documentation/devicetree/bindings/media/s5p-cec.txt
@@ -15,6 +15,7 @@ Required properties:
   - clock-names : from common clock binding: must contain "hdmicec",
 		  corresponding to entry in the clocks property.
   - samsung,syscon-phandle - phandle to the PMU system controller
+  - samsung,hdmi-phandle - phandle to the HDMI controller
 
 Example:
 
@@ -25,6 +26,7 @@ hdmicec: cec at 100B0000 {
 	clocks = <&clock CLK_HDMI_CEC>;
 	clock-names = "hdmicec";
 	samsung,syscon-phandle = <&pmu_system_controller>;
+	samsung,hdmi-phandle = <&hdmi>;
 	pinctrl-names = "default";
 	pinctrl-0 = <&hdmi_cec>;
 	status = "okay";
diff --git a/arch/arm/boot/dts/exynos4.dtsi b/arch/arm/boot/dts/exynos4.dtsi
index 5f034eb..48ab7fc 100644
--- a/arch/arm/boot/dts/exynos4.dtsi
+++ b/arch/arm/boot/dts/exynos4.dtsi
@@ -750,6 +750,7 @@
 		clocks = <&clock CLK_HDMI_CEC>;
 		clock-names = "hdmicec";
 		samsung,syscon-phandle = <&pmu_system_controller>;
+		samsung,hdmi-phandle = <&hdmi>;
 		pinctrl-names = "default";
 		pinctrl-0 = <&hdmi_cec>;
 		status = "disabled";
diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
index d944421..42f747a 100644
--- a/drivers/media/platform/Kconfig
+++ b/drivers/media/platform/Kconfig
@@ -392,6 +392,24 @@ config VIDEO_TI_SC
 config VIDEO_TI_CSC
 	tristate
 
+menuconfig V4L_CEC_DRIVERS
+	bool "Platform HDMI CEC drivers"
+	depends on MEDIA_CEC_SUPPORT
+
+if V4L_CEC_DRIVERS
+
+config VIDEO_SAMSUNG_S5P_CEC
+       tristate "Samsung S5P CEC driver"
+       depends on VIDEO_DEV && MEDIA_CEC_SUPPORT && (PLAT_S5P || ARCH_EXYNOS || COMPILE_TEST)
+       select HDMI_NOTIFIERS
+       ---help---
+         This is a driver for Samsung S5P HDMI CEC interface. It uses the
+         generic CEC framework interface.
+         CEC bus is present in the HDMI connector and enables communication
+         between compatible devices.
+
+endif #V4L_CEC_DRIVERS
+
 menuconfig V4L_TEST_DRIVERS
 	bool "Media test drivers"
 	depends on MEDIA_CAMERA_SUPPORT
diff --git a/drivers/media/platform/Makefile b/drivers/media/platform/Makefile
index 5b3cb27..ad3bf22 100644
--- a/drivers/media/platform/Makefile
+++ b/drivers/media/platform/Makefile
@@ -33,6 +33,7 @@ obj-$(CONFIG_VIDEO_SAMSUNG_S5P_JPEG)	+= s5p-jpeg/
 obj-$(CONFIG_VIDEO_SAMSUNG_S5P_MFC)	+= s5p-mfc/
 
 obj-$(CONFIG_VIDEO_SAMSUNG_S5P_G2D)	+= s5p-g2d/
+obj-$(CONFIG_VIDEO_SAMSUNG_S5P_CEC)	+= s5p-cec/
 obj-$(CONFIG_VIDEO_SAMSUNG_EXYNOS_GSC)	+= exynos-gsc/
 
 obj-$(CONFIG_VIDEO_STI_BDISP)		+= sti/bdisp/
diff --git a/drivers/staging/media/s5p-cec/Makefile b/drivers/media/platform/s5p-cec/Makefile
similarity index 100%
rename from drivers/staging/media/s5p-cec/Makefile
rename to drivers/media/platform/s5p-cec/Makefile
diff --git a/drivers/staging/media/s5p-cec/exynos_hdmi_cec.h b/drivers/media/platform/s5p-cec/exynos_hdmi_cec.h
similarity index 100%
rename from drivers/staging/media/s5p-cec/exynos_hdmi_cec.h
rename to drivers/media/platform/s5p-cec/exynos_hdmi_cec.h
diff --git a/drivers/staging/media/s5p-cec/exynos_hdmi_cecctrl.c b/drivers/media/platform/s5p-cec/exynos_hdmi_cecctrl.c
similarity index 100%
rename from drivers/staging/media/s5p-cec/exynos_hdmi_cecctrl.c
rename to drivers/media/platform/s5p-cec/exynos_hdmi_cecctrl.c
diff --git a/drivers/staging/media/s5p-cec/regs-cec.h b/drivers/media/platform/s5p-cec/regs-cec.h
similarity index 100%
rename from drivers/staging/media/s5p-cec/regs-cec.h
rename to drivers/media/platform/s5p-cec/regs-cec.h
diff --git a/drivers/staging/media/s5p-cec/s5p_cec.c b/drivers/media/platform/s5p-cec/s5p_cec.c
similarity index 89%
rename from drivers/staging/media/s5p-cec/s5p_cec.c
rename to drivers/media/platform/s5p-cec/s5p_cec.c
index 2a07968..565ee92 100644
--- a/drivers/staging/media/s5p-cec/s5p_cec.c
+++ b/drivers/media/platform/s5p-cec/s5p_cec.c
@@ -14,15 +14,18 @@
  */
 
 #include <linux/clk.h>
+#include <linux/hdmi-notifier.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/timer.h>
 #include <linux/workqueue.h>
+#include <media/cec-edid.h>
 #include <media/cec.h>
 
 #include "exynos_hdmi_cec.h"
@@ -167,10 +170,22 @@ static const struct cec_adap_ops s5p_cec_adap_ops = {
 static int s5p_cec_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
+	struct device_node *np;
+	struct platform_device *hdmi_dev;
 	struct resource *res;
 	struct s5p_cec_dev *cec;
 	int ret;
 
+	np = of_parse_phandle(pdev->dev.of_node, "samsung,hdmi-phandle", 0);
+
+	if (!np) {
+		dev_err(&pdev->dev, "Failed to find hdmi node in device tree\n");
+		return -ENODEV;
+	}
+	hdmi_dev = of_find_device_by_node(np);
+	if (hdmi_dev == NULL)
+		return -EPROBE_DEFER;
+
 	cec = devm_kzalloc(&pdev->dev, sizeof(*cec), GFP_KERNEL);
 	if (!cec)
 		return -ENOMEM;
@@ -200,24 +215,33 @@ static int s5p_cec_probe(struct platform_device *pdev)
 	if (IS_ERR(cec->reg))
 		return PTR_ERR(cec->reg);
 
+	cec->notifier = hdmi_notifier_get(&hdmi_dev->dev);
+	if (cec->notifier == NULL)
+		return -ENOMEM;
+
 	cec->adap = cec_allocate_adapter(&s5p_cec_adap_ops, cec,
 		CEC_NAME,
-		CEC_CAP_PHYS_ADDR | CEC_CAP_LOG_ADDRS | CEC_CAP_TRANSMIT |
+		CEC_CAP_LOG_ADDRS | CEC_CAP_TRANSMIT |
 		CEC_CAP_PASSTHROUGH | CEC_CAP_RC, 1);
 	ret = PTR_ERR_OR_ZERO(cec->adap);
 	if (ret)
 		return ret;
+
 	ret = cec_register_adapter(cec->adap, &pdev->dev);
-	if (ret) {
-		cec_delete_adapter(cec->adap);
-		return ret;
-	}
+	if (ret)
+		goto err_delete_adapter;
+
+	cec_register_hdmi_notifier(cec->adap, cec->notifier);
 
 	platform_set_drvdata(pdev, cec);
 	pm_runtime_enable(dev);
 
 	dev_dbg(dev, "successfuly probed\n");
 	return 0;
+
+err_delete_adapter:
+	cec_delete_adapter(cec->adap);
+	return ret;
 }
 
 static int s5p_cec_remove(struct platform_device *pdev)
@@ -225,6 +249,7 @@ static int s5p_cec_remove(struct platform_device *pdev)
 	struct s5p_cec_dev *cec = platform_get_drvdata(pdev);
 
 	cec_unregister_adapter(cec->adap);
+	hdmi_notifier_put(cec->notifier);
 	pm_runtime_disable(&pdev->dev);
 	return 0;
 }
diff --git a/drivers/staging/media/s5p-cec/s5p_cec.h b/drivers/media/platform/s5p-cec/s5p_cec.h
similarity index 97%
rename from drivers/staging/media/s5p-cec/s5p_cec.h
rename to drivers/media/platform/s5p-cec/s5p_cec.h
index 03732c1..69856b1 100644
--- a/drivers/staging/media/s5p-cec/s5p_cec.h
+++ b/drivers/media/platform/s5p-cec/s5p_cec.h
@@ -59,12 +59,15 @@ enum cec_state {
 	STATE_ERROR
 };
 
+struct hdmi_notifier;
+
 struct s5p_cec_dev {
 	struct cec_adapter	*adap;
 	struct clk		*clk;
 	struct device		*dev;
 	struct mutex		lock;
 	struct regmap           *pmu;
+	struct hdmi_notifier	*notifier;
 	int			irq;
 	void __iomem		*reg;
 
diff --git a/drivers/staging/media/Kconfig b/drivers/staging/media/Kconfig
index ffb8fa7..1b7804c 100644
--- a/drivers/staging/media/Kconfig
+++ b/drivers/staging/media/Kconfig
@@ -27,8 +27,6 @@ source "drivers/staging/media/davinci_vpfe/Kconfig"
 
 source "drivers/staging/media/omap4iss/Kconfig"
 
-source "drivers/staging/media/s5p-cec/Kconfig"
-
 # Keep LIRC at the end, as it has sub-menus
 source "drivers/staging/media/lirc/Kconfig"
 
diff --git a/drivers/staging/media/Makefile b/drivers/staging/media/Makefile
index a28e82c..e11afbf 100644
--- a/drivers/staging/media/Makefile
+++ b/drivers/staging/media/Makefile
@@ -1,5 +1,4 @@
 obj-$(CONFIG_I2C_BCM2048)	+= bcm2048/
-obj-$(CONFIG_VIDEO_SAMSUNG_S5P_CEC) += s5p-cec/
 obj-$(CONFIG_DVB_CXD2099)	+= cxd2099/
 obj-$(CONFIG_LIRC_STAGING)	+= lirc/
 obj-$(CONFIG_VIDEO_DM365_VPFE)	+= davinci_vpfe/
diff --git a/drivers/staging/media/s5p-cec/Kconfig b/drivers/staging/media/s5p-cec/Kconfig
deleted file mode 100644
index ddfd955..0000000
--- a/drivers/staging/media/s5p-cec/Kconfig
+++ /dev/null
@@ -1,9 +0,0 @@
-config VIDEO_SAMSUNG_S5P_CEC
-       tristate "Samsung S5P CEC driver"
-       depends on VIDEO_DEV && MEDIA_CEC_SUPPORT && (PLAT_S5P || ARCH_EXYNOS || COMPILE_TEST)
-       ---help---
-         This is a driver for Samsung S5P HDMI CEC interface. It uses the
-         generic CEC framework interface.
-         CEC bus is present in the HDMI connector and enables communication
-         between compatible devices.
-
diff --git a/drivers/staging/media/s5p-cec/TODO b/drivers/staging/media/s5p-cec/TODO
deleted file mode 100644
index 64f21ba..0000000
--- a/drivers/staging/media/s5p-cec/TODO
+++ /dev/null
@@ -1,7 +0,0 @@
-This driver requires that userspace sets the physical address.
-However, this should be passed on from the corresponding
-Samsung HDMI driver.
-
-We have to wait until the HDMI notifier framework has been merged
-in order to handle this gracefully, until that time this driver
-has to remain in staging.
-- 
2.10.2

[PATCH 0/4] video/exynos/cec: add HDMI state notifier & use in s5p-cec

[Marek Szyprowski]

Hi Hans,


On 2016-12-13 16:08, Hans Verkuil wrote:
> From: Hans Verkuil <hans.verkuil@cisco.com>
>
> This patch series adds the HDMI notifier code, based on Russell's code:
>
> https://patchwork.kernel.org/patch/9277043/
>
> It adds support for it to the exynos_hdmi drm driver, adds support for
> it to the CEC framework and finally adds support to the s5p-cec driver,
> which now can be moved out of staging.
>
> Tested with my Odroid U3 exynos4 devboard.
>
> Comments are welcome. I'd like to get this in for the 4.11 kernel as
> this is a missing piece needed to integrate CEC drivers.
>
> Benjamin, can you look at doing the same notifier integration for your
> st-cec driver as is done for s5p-cec? It would be good to be able to
> move st-cec out of staging at the same time.

Thanks for working on this and taking it from by TODO list! :)

Please add:
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>

If you plan to send an updated version, please send it also to
linux-samsung-soc at vger.kernel.org, Krzysztof and Inki to get their acks
for the bindings, dtsi and drm parts.

This HDMI notifier framework will probably be also useful for integrating
HDMI audio support for Samsung ASoC driver.

> Regards,
>
> 	Hans
>
> Hans Verkuil (4):
>    video: add HDMI state notifier support
>    exynos_hdmi: add HDMI notifier support
>    cec: integrate HDMI notifier support
>    s5p-cec: add hdmi-notifier support, move out of staging
>
>   .../devicetree/bindings/media/s5p-cec.txt          |   2 +
>   arch/arm/boot/dts/exynos4.dtsi                     |   1 +
>   drivers/gpu/drm/exynos/Kconfig                     |   1 +
>   drivers/gpu/drm/exynos/exynos_hdmi.c               |  24 +++-
>   drivers/media/cec/cec-core.c                       |  50 ++++++++
>   drivers/media/platform/Kconfig                     |  18 +++
>   drivers/media/platform/Makefile                    |   1 +
>   .../media => media/platform}/s5p-cec/Makefile      |   0
>   .../platform}/s5p-cec/exynos_hdmi_cec.h            |   0
>   .../platform}/s5p-cec/exynos_hdmi_cecctrl.c        |   0
>   .../media => media/platform}/s5p-cec/regs-cec.h    |   0
>   .../media => media/platform}/s5p-cec/s5p_cec.c     |  35 +++++-
>   .../media => media/platform}/s5p-cec/s5p_cec.h     |   3 +
>   drivers/staging/media/Kconfig                      |   2 -
>   drivers/staging/media/Makefile                     |   1 -
>   drivers/staging/media/s5p-cec/Kconfig              |   9 --
>   drivers/staging/media/s5p-cec/TODO                 |   7 --
>   drivers/video/Kconfig                              |   3 +
>   drivers/video/Makefile                             |   1 +
>   drivers/video/hdmi-notifier.c                      | 134 +++++++++++++++++++++
>   include/linux/hdmi-notifier.h                      | 109 +++++++++++++++++
>   include/media/cec.h                                |  15 +++
>   22 files changed, 389 insertions(+), 27 deletions(-)
>   rename drivers/{staging/media => media/platform}/s5p-cec/Makefile (100%)
>   rename drivers/{staging/media => media/platform}/s5p-cec/exynos_hdmi_cec.h (100%)
>   rename drivers/{staging/media => media/platform}/s5p-cec/exynos_hdmi_cecctrl.c (100%)
>   rename drivers/{staging/media => media/platform}/s5p-cec/regs-cec.h (100%)
>   rename drivers/{staging/media => media/platform}/s5p-cec/s5p_cec.c (89%)
>   rename drivers/{staging/media => media/platform}/s5p-cec/s5p_cec.h (97%)
>   delete mode 100644 drivers/staging/media/s5p-cec/Kconfig
>   delete mode 100644 drivers/staging/media/s5p-cec/TODO
>   create mode 100644 drivers/video/hdmi-notifier.c
>   create mode 100644 include/linux/hdmi-notifier.h
>

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland

[PATCH 1/4] video: add HDMI state notifier support

[Philipp Zabel]

Am Dienstag, den 13.12.2016, 16:08 +0100 schrieb Hans Verkuil:
> From: Hans Verkuil <hans.verkuil@cisco.com>
> 
> Add support for HDMI hotplug and EDID notifiers, which is used to convey
> information from HDMI drivers to their CEC and audio counterparts.
> 
> Based on an earlier version from Russell King:
> 
> https://patchwork.kernel.org/patch/9277043/
> 
> The hdmi_notifier is a reference counted object containing the HDMI state
> of an HDMI device.
> 
> When a new notifier is registered the current state will be reported to
> that notifier at registration time.
> 
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>

Acked-by: Philipp Zabel <p.zabel@pengutronix.de>

regards
Philipp

> ---
>  drivers/video/Kconfig         |   3 +
>  drivers/video/Makefile        |   1 +
>  drivers/video/hdmi-notifier.c | 134 ++++++++++++++++++++++++++++++++++++++++++
>  include/linux/hdmi-notifier.h | 109 ++++++++++++++++++++++++++++++++++
>  4 files changed, 247 insertions(+)
>  create mode 100644 drivers/video/hdmi-notifier.c
>  create mode 100644 include/linux/hdmi-notifier.h
> 
> diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
> index 3c20af9..1ee7b9f 100644
> --- a/drivers/video/Kconfig
> +++ b/drivers/video/Kconfig
> @@ -36,6 +36,9 @@ config VIDEOMODE_HELPERS
>  config HDMI
>  	bool
>  
> +config HDMI_NOTIFIERS
> +	bool
> +
>  if VT
>  	source "drivers/video/console/Kconfig"
>  endif
> diff --git a/drivers/video/Makefile b/drivers/video/Makefile
> index 9ad3c17..65f5649 100644
> --- a/drivers/video/Makefile
> +++ b/drivers/video/Makefile
> @@ -1,5 +1,6 @@
>  obj-$(CONFIG_VGASTATE)            += vgastate.o
>  obj-$(CONFIG_HDMI)                += hdmi.o
> +obj-$(CONFIG_HDMI_NOTIFIERS)      += hdmi-notifier.o
>  
>  obj-$(CONFIG_VT)		  += console/
>  obj-$(CONFIG_LOGO)		  += logo/
> diff --git a/drivers/video/hdmi-notifier.c b/drivers/video/hdmi-notifier.c
> new file mode 100644
> index 0000000..29e4225
> --- /dev/null
> +++ b/drivers/video/hdmi-notifier.c
> @@ -0,0 +1,134 @@
> +#include <linux/export.h>
> +#include <linux/hdmi-notifier.h>
> +#include <linux/string.h>
> +#include <linux/slab.h>
> +#include <linux/list.h>
> +
> +static LIST_HEAD(hdmi_notifiers);
> +static DEFINE_MUTEX(hdmi_notifiers_lock);
> +
> +struct hdmi_notifier *hdmi_notifier_get(struct device *dev)
> +{
> +	struct hdmi_notifier *n;
> +
> +	mutex_lock(&hdmi_notifiers_lock);
> +	list_for_each_entry(n, &hdmi_notifiers, head) {
> +		if (n->dev == dev) {
> +			mutex_unlock(&hdmi_notifiers_lock);
> +			kref_get(&n->kref);
> +			return n;
> +		}
> +	}
> +	n = kzalloc(sizeof(*n), GFP_KERNEL);
> +	if (!n)
> +		goto unlock;
> +	n->dev = dev;
> +	mutex_init(&n->lock);
> +	BLOCKING_INIT_NOTIFIER_HEAD(&n->notifiers);
> +	kref_init(&n->kref);
> +	list_add_tail(&n->head, &hdmi_notifiers);
> +unlock:
> +	mutex_unlock(&hdmi_notifiers_lock);
> +	return n;
> +}
> +EXPORT_SYMBOL_GPL(hdmi_notifier_get);
> +
> +static void hdmi_notifier_release(struct kref *kref)
> +{
> +	struct hdmi_notifier *n =
> +		container_of(kref, struct hdmi_notifier, kref);
> +
> +	mutex_lock(&hdmi_notifiers_lock);
> +	list_del(&n->head);
> +	mutex_unlock(&hdmi_notifiers_lock);
> +	kfree(n->edid);
> +	kfree(n);
> +}
> +
> +void hdmi_notifier_put(struct hdmi_notifier *n)
> +{
> +	kref_put(&n->kref, hdmi_notifier_release);
> +}
> +EXPORT_SYMBOL_GPL(hdmi_notifier_put);
> +
> +int hdmi_notifier_register(struct hdmi_notifier *n, struct notifier_block *nb)
> +{
> +	int ret = blocking_notifier_chain_register(&n->notifiers, nb);
> +
> +	if (ret)
> +		return ret;
> +	kref_get(&n->kref);
> +	mutex_lock(&n->lock);
> +	if (n->connected) {
> +		blocking_notifier_call_chain(&n->notifiers, HDMI_CONNECTED, n);
> +		if (n->edid_size)
> +			blocking_notifier_call_chain(&n->notifiers, HDMI_NEW_EDID, n);
> +		if (n->has_eld)
> +			blocking_notifier_call_chain(&n->notifiers, HDMI_NEW_ELD, n);
> +	}
> +	mutex_unlock(&n->lock);
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(hdmi_notifier_register);
> +
> +int hdmi_notifier_unregister(struct hdmi_notifier *n, struct notifier_block *nb)
> +{
> +	int ret = blocking_notifier_chain_unregister(&n->notifiers, nb);
> +
> +	if (ret == 0)
> +		hdmi_notifier_put(n);
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(hdmi_notifier_unregister);
> +
> +void hdmi_event_connect(struct hdmi_notifier *n)
> +{
> +	mutex_lock(&n->lock);
> +	n->connected = true;
> +	blocking_notifier_call_chain(&n->notifiers, HDMI_CONNECTED, n);
> +	mutex_unlock(&n->lock);
> +}
> +EXPORT_SYMBOL_GPL(hdmi_event_connect);
> +
> +void hdmi_event_disconnect(struct hdmi_notifier *n)
> +{
> +	mutex_lock(&n->lock);
> +	n->connected = false;
> +	n->has_eld = false;
> +	n->edid_size = 0;
> +	blocking_notifier_call_chain(&n->notifiers, HDMI_DISCONNECTED, n);
> +	mutex_unlock(&n->lock);
> +}
> +EXPORT_SYMBOL_GPL(hdmi_event_disconnect);
> +
> +int hdmi_event_new_edid(struct hdmi_notifier *n, const void *edid, size_t size)
> +{
> +	mutex_lock(&n->lock);
> +	if (n->edid_allocated_size < size) {
> +		void *p = kmalloc(size, GFP_KERNEL);
> +
> +		if (p == NULL) {
> +			mutex_unlock(&n->lock);
> +			return -ENOMEM;
> +		}
> +		kfree(n->edid);
> +		n->edid = p;
> +		n->edid_allocated_size = size;
> +	}
> +	memcpy(n->edid, edid, size);
> +	n->edid_size = size;
> +	blocking_notifier_call_chain(&n->notifiers, HDMI_NEW_EDID, n);
> +	mutex_unlock(&n->lock);
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(hdmi_event_new_edid);
> +
> +void hdmi_event_new_eld(struct hdmi_notifier *n, const u8 eld[128])
> +{
> +	mutex_lock(&n->lock);
> +	memcpy(n->eld, eld, sizeof(n->eld));
> +	n->has_eld = true;
> +	blocking_notifier_call_chain(&n->notifiers, HDMI_NEW_ELD, n);
> +	mutex_unlock(&n->lock);
> +}
> +EXPORT_SYMBOL_GPL(hdmi_event_new_eld);
> diff --git a/include/linux/hdmi-notifier.h b/include/linux/hdmi-notifier.h
> new file mode 100644
> index 0000000..1d88db0
> --- /dev/null
> +++ b/include/linux/hdmi-notifier.h
> @@ -0,0 +1,109 @@
> +/*
> + * hdmi-notifier.h - notify interested parties of (dis)connect and EDID
> + * events
> + *
> + * Copyright 2016 Russell King <rmk+kernel@arm.linux.org.uk>
> + * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
> + */
> +
> +#ifndef LINUX_HDMI_NOTIFIER_H
> +#define LINUX_HDMI_NOTIFIER_H
> +
> +#include <linux/types.h>
> +#include <linux/notifier.h>
> +#include <linux/kref.h>
> +
> +enum {
> +	HDMI_CONNECTED,
> +	HDMI_DISCONNECTED,
> +	HDMI_NEW_EDID,
> +	HDMI_NEW_ELD,
> +};
> +
> +struct device;
> +
> +struct hdmi_notifier {
> +	struct mutex lock;
> +	struct list_head head;
> +	struct kref kref;
> +	struct blocking_notifier_head notifiers;
> +	struct device *dev;
> +
> +	/* Current state */
> +	bool connected;
> +	bool has_eld;
> +	unsigned char eld[128];
> +	void *edid;
> +	size_t edid_size;
> +	size_t edid_allocated_size;
> +};
> +
> +/**
> + * hdmi_notifier_get - find or create a new hdmi_notifier for the given device.
> + * @dev: device that sends the events.
> + *
> + * If a notifier for device @dev already exists, then increase the refcount
> + * and return that notifier.
> + *
> + * If it doesn't exist, then allocate a new notifier struct and return a
> + * pointer to that new struct.
> + *
> + * Return NULL if the memory could not be allocated.
> + */
> +struct hdmi_notifier *hdmi_notifier_get(struct device *dev);
> +
> +/**
> + * hdmi_notifier_put - decrease refcount and delete when the refcount reaches 0.
> + * @n: notifier
> + */
> +void hdmi_notifier_put(struct hdmi_notifier *n);
> +
> +/**
> + * hdmi_notifier_register - register the notifier with the notifier_block.
> + * @n: the HDMI notifier
> + * @nb: the notifier_block
> + */
> +int hdmi_notifier_register(struct hdmi_notifier *n, struct notifier_block *nb);
> +
> +/**
> + * hdmi_notifier_unregister - unregister the notifier with the notifier_block.
> + * @n: the HDMI notifier
> + * @nb: the notifier_block
> + */
> +int hdmi_notifier_unregister(struct hdmi_notifier *n, struct notifier_block *nb);
> +
> +/**
> + * hdmi_event_connect - send a connect event.
> + * @n: the HDMI notifier
> + *
> + * Send an HDMI_CONNECTED event to any registered parties.
> + */
> +void hdmi_event_connect(struct hdmi_notifier *n);
> +
> +/**
> + * hdmi_event_disconnect - send a disconnect event.
> + * @n: the HDMI notifier
> + *
> + * Send an HDMI_DISCONNECTED event to any registered parties.
> + */
> +void hdmi_event_disconnect(struct hdmi_notifier *n);
> +
> +/**
> + * hdmi_event_new_edid - send a new EDID event.
> + * @n: the HDMI notifier
> + *
> + * Send an HDMI_NEW_EDID event to any registered parties.
> + * This function will make a copy the EDID so it can return -ENOMEM if
> + * no memory could be allocated.
> + */
> +int hdmi_event_new_edid(struct hdmi_notifier *n, const void *edid, size_t size);
> +
> +/**
> + * hdmi_event_new_eld - send a new ELD event.
> + * @n: the HDMI notifier
> + *
> + * Send an HDMI_NEW_ELD event to any registered parties.
> + */
> +void hdmi_event_new_eld(struct hdmi_notifier *n, const u8 eld[128]);
> +
> +#endif