On 11/14/16 16:22, Hans Verkuil wrote:
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.
I realized that the name 'HDMI notifier' isn't the best: the same mechanism can be used with e.g. DisplayPort as well.
What would be a good alternative name?
"Video Notifier"?
Any objections to that? Or suggestions for a better name?
Regards,
Hans
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 | 136 ++++++++++++++++++++++++++++++++++++++++++ include/linux/hdmi-notifier.h | 43 +++++++++++++ 4 files changed, 183 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..c2a4f1b --- /dev/null +++ b/drivers/video/hdmi-notifier.c @@ -0,0 +1,136 @@ +#include <linux/export.h> +#include <linux/hdmi-notifier.h> +#include <linux/string.h> +#include <linux/slab.h> +#include <linux/list.h>
+struct hdmi_notifiers {
- struct list_head head;
- struct device *dev;
- struct hdmi_notifier *n;
+};
+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;- 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);- 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..f7fc405 --- /dev/null +++ b/include/linux/hdmi-notifier.h @@ -0,0 +1,43 @@ +#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;
+};
+struct hdmi_notifier *hdmi_notifier_get(struct device *dev); +void hdmi_notifier_put(struct hdmi_notifier *n); +int hdmi_notifier_register(struct hdmi_notifier *n, struct notifier_block *nb); +int hdmi_notifier_unregister(struct hdmi_notifier *n, struct notifier_block *nb);
+void hdmi_event_connect(struct hdmi_notifier *n); +void hdmi_event_disconnect(struct hdmi_notifier *n); +int hdmi_event_new_edid(struct hdmi_notifier *n, const void *edid, size_t size); +void hdmi_event_new_eld(struct hdmi_notifier *n, const u8 eld[128]);
+#endif