On 11/14/16 16:22, Hans Verkuil wrote:
From: Hans Verkuil <hans.verkuil@xxxxxxxxx> 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@xxxxxxxxx> --- 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
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