[PATCHv5 02/11] media: add CEC notifier support
Hans Verkuil
hverkuil at xs4all.nl
Wed Mar 29 14:15:34 UTC 2017
From: Hans Verkuil <hans.verkuil at cisco.com>
Add support for CEC notifiers, which is used to convey CEC physical address
information from video drivers to their CEC counterpart driver(s).
Based on an earlier version from Russell King:
https://patchwork.kernel.org/patch/9277043/
The cec_notifier is a reference counted object containing the CEC physical address
state of a video 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 at cisco.com>
Tested-by: Marek Szyprowski <m.szyprowski at samsung.com>
---
MAINTAINERS | 4 +-
drivers/media/Kconfig | 3 ++
drivers/media/Makefile | 4 ++
drivers/media/cec-notifier.c | 116 +++++++++++++++++++++++++++++++++++++++++++
include/media/cec-notifier.h | 93 ++++++++++++++++++++++++++++++++++
5 files changed, 219 insertions(+), 1 deletion(-)
create mode 100644 drivers/media/cec-notifier.c
create mode 100644 include/media/cec-notifier.h
diff --git a/MAINTAINERS b/MAINTAINERS
index 83a42ef1d1a7..cfb2670aa372 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3066,7 +3066,7 @@ F: drivers/net/ieee802154/cc2520.c
F: include/linux/spi/cc2520.h
F: Documentation/devicetree/bindings/net/ieee802154/cc2520.txt
-CEC DRIVER
+CEC FRAMEWORK
M: Hans Verkuil <hans.verkuil at cisco.com>
L: linux-media at vger.kernel.org
T: git git://linuxtv.org/media_tree.git
@@ -3076,9 +3076,11 @@ F: Documentation/media/kapi/cec-core.rst
F: Documentation/media/uapi/cec
F: drivers/media/cec/
F: drivers/media/cec-edid.c
+F: drivers/media/cec-notifier.c
F: drivers/media/rc/keymaps/rc-cec.c
F: include/media/cec.h
F: include/media/cec-edid.h
+F: include/media/cec-notifier.h
F: include/uapi/linux/cec.h
F: include/uapi/linux/cec-funcs.h
diff --git a/drivers/media/Kconfig b/drivers/media/Kconfig
index 3512316e7a46..799429f51d1a 100644
--- a/drivers/media/Kconfig
+++ b/drivers/media/Kconfig
@@ -99,6 +99,9 @@ config MEDIA_CEC_DEBUG
config MEDIA_CEC_EDID
bool
+config MEDIA_CEC_NOTIFIER
+ bool
+
#
# Media controller
# Selectable only for webcam/grabbers, as other drivers don't use it
diff --git a/drivers/media/Makefile b/drivers/media/Makefile
index d87ccb8eeabe..8b36a571d443 100644
--- a/drivers/media/Makefile
+++ b/drivers/media/Makefile
@@ -6,6 +6,10 @@ ifeq ($(CONFIG_MEDIA_CEC_EDID),y)
obj-$(CONFIG_MEDIA_SUPPORT) += cec-edid.o
endif
+ifeq ($(CONFIG_MEDIA_CEC_NOTIFIER),y)
+ obj-$(CONFIG_MEDIA_SUPPORT) += cec-notifier.o
+endif
+
ifeq ($(CONFIG_MEDIA_CEC_SUPPORT),y)
obj-$(CONFIG_MEDIA_SUPPORT) += cec/
endif
diff --git a/drivers/media/cec-notifier.c b/drivers/media/cec-notifier.c
new file mode 100644
index 000000000000..a5938c4d3ab4
--- /dev/null
+++ b/drivers/media/cec-notifier.c
@@ -0,0 +1,116 @@
+/*
+ * cec-notifier.c - notify CEC drivers of physical address changes
+ *
+ * Copyright 2016 Russell King <rmk+kernel at arm.linux.org.uk>
+ * Copyright 2016-2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
+ *
+ * This program is free software; you may redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/export.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/kref.h>
+
+#include <media/cec-notifier.h>
+
+struct cec_notifier {
+ struct mutex lock;
+ struct list_head head;
+ struct kref kref;
+ struct device *dev;
+ struct cec_adapter *cec_adap;
+ void (*callback)(struct cec_adapter *adap, u16 pa);
+
+ u16 phys_addr;
+};
+
+static LIST_HEAD(cec_notifiers);
+static DEFINE_MUTEX(cec_notifiers_lock);
+
+struct cec_notifier *cec_notifier_get(struct device *dev)
+{
+ struct cec_notifier *n;
+
+ mutex_lock(&cec_notifiers_lock);
+ list_for_each_entry(n, &cec_notifiers, head) {
+ if (n->dev == dev) {
+ mutex_unlock(&cec_notifiers_lock);
+ kref_get(&n->kref);
+ return n;
+ }
+ }
+ n = kzalloc(sizeof(*n), GFP_KERNEL);
+ if (!n)
+ goto unlock;
+ n->dev = dev;
+ n->phys_addr = CEC_PHYS_ADDR_INVALID;
+ mutex_init(&n->lock);
+ kref_init(&n->kref);
+ list_add_tail(&n->head, &cec_notifiers);
+unlock:
+ mutex_unlock(&cec_notifiers_lock);
+ return n;
+}
+EXPORT_SYMBOL_GPL(cec_notifier_get);
+
+static void cec_notifier_release(struct kref *kref)
+{
+ struct cec_notifier *n =
+ container_of(kref, struct cec_notifier, kref);
+
+ list_del(&n->head);
+ kfree(n);
+}
+
+void cec_notifier_put(struct cec_notifier *n)
+{
+ mutex_lock(&cec_notifiers_lock);
+ kref_put(&n->kref, cec_notifier_release);
+ mutex_unlock(&cec_notifiers_lock);
+}
+EXPORT_SYMBOL_GPL(cec_notifier_put);
+
+void cec_notifier_set_phys_addr(struct cec_notifier *n, u16 pa)
+{
+ mutex_lock(&n->lock);
+ n->phys_addr = pa;
+ if (n->callback)
+ n->callback(n->cec_adap, n->phys_addr);
+ mutex_unlock(&n->lock);
+}
+EXPORT_SYMBOL_GPL(cec_notifier_set_phys_addr);
+
+void cec_notifier_register(struct cec_notifier *n,
+ struct cec_adapter *adap,
+ void (*callback)(struct cec_adapter *adap, u16 pa))
+{
+ kref_get(&n->kref);
+ mutex_lock(&n->lock);
+ n->cec_adap = adap;
+ n->callback = callback;
+ n->callback(adap, n->phys_addr);
+ mutex_unlock(&n->lock);
+}
+EXPORT_SYMBOL_GPL(cec_notifier_register);
+
+void cec_notifier_unregister(struct cec_notifier *n)
+{
+ mutex_lock(&n->lock);
+ n->callback = NULL;
+ mutex_unlock(&n->lock);
+ cec_notifier_put(n);
+}
+EXPORT_SYMBOL_GPL(cec_notifier_unregister);
diff --git a/include/media/cec-notifier.h b/include/media/cec-notifier.h
new file mode 100644
index 000000000000..79ad3a48361c
--- /dev/null
+++ b/include/media/cec-notifier.h
@@ -0,0 +1,93 @@
+/*
+ * cec-notifier.h - notify CEC drivers of physical address changes
+ *
+ * Copyright 2016 Russell King <rmk+kernel at arm.linux.org.uk>
+ * Copyright 2016-2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
+ *
+ * This program is free software; you may redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef LINUX_CEC_NOTIFIER_H
+#define LINUX_CEC_NOTIFIER_H
+
+#include <linux/types.h>
+#include <media/cec-edid.h>
+
+struct device;
+struct cec_adapter;
+struct cec_notifier;
+
+#ifdef CONFIG_MEDIA_CEC_NOTIFIER
+
+/**
+ * cec_notifier_get - find or create a new cec_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 cec_notifier *cec_notifier_get(struct device *dev);
+
+/**
+ * cec_notifier_put - decrease refcount and delete when the refcount reaches 0.
+ * @n: notifier
+ */
+void cec_notifier_put(struct cec_notifier *n);
+
+/**
+ * cec_notifier_set_phys_addr - set a new physical address.
+ * @n: the CEC notifier
+ *
+ * Set a new CEC physical address.
+ */
+void cec_notifier_set_phys_addr(struct cec_notifier *n, u16 pa);
+
+/**
+ * cec_notifier_register - register a callback with the notifier
+ * @n: the CEC notifier
+ * @adap: the CEC adapter, passed as argument to the callback function
+ * @callback: the callback function
+ */
+void cec_notifier_register(struct cec_notifier *n,
+ struct cec_adapter *adap,
+ void (*callback)(struct cec_adapter *adap, u16 pa));
+
+/**
+ * cec_notifier_unregister - unregister the callback from the notifier.
+ * @n: the CEC notifier
+ */
+void cec_notifier_unregister(struct cec_notifier *n);
+
+#else
+static inline struct cec_notifier *cec_notifier_get(struct device *dev)
+{
+ /* A non-NULL pointer is expected on success */
+ return (struct cec_notifier *)0xdeadfeed;
+}
+
+static inline void cec_notifier_put(struct cec_notifier *n)
+{
+}
+
+static inline void cec_notifier_set_phys_addr(struct cec_notifier *n, u16 pa)
+{
+}
+#endif
+
+#endif
--
2.11.0
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