[PATCH 1/5] media: cec-notifier: Get notifier by device and connector name

From: Neil Armstrong
Date: Tue May 15 2018 - 13:38:28 EST


In non device-tree world, we can need to get the notifier by the driver
name directly and eventually defer probe if not yet created.

This patch adds a variant of the get function by using the device name
instead and will not create a notifier if not yet created.

But the i915 driver exposes at least 2 HDMI connectors, this patch also
adds the possibility to add a connector name tied to the notifier device
to form a tuple and associate different CEC controllers for each HDMI
connectors.

Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
---
drivers/media/cec/cec-notifier.c | 12 +++++++++---
include/media/cec-notifier.h | 30 ++++++++++++++++++++++++++++--
2 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/drivers/media/cec/cec-notifier.c b/drivers/media/cec/cec-notifier.c
index 16dffa0..7038abae1 100644
--- a/drivers/media/cec/cec-notifier.c
+++ b/drivers/media/cec/cec-notifier.c
@@ -21,6 +21,7 @@ struct cec_notifier {
struct list_head head;
struct kref kref;
struct device *dev;
+ const char *conn;
struct cec_adapter *cec_adap;
void (*callback)(struct cec_adapter *adap, u16 pa);

@@ -30,13 +31,14 @@ struct cec_notifier {
static LIST_HEAD(cec_notifiers);
static DEFINE_MUTEX(cec_notifiers_lock);

-struct cec_notifier *cec_notifier_get(struct device *dev)
+struct cec_notifier *cec_notifier_get_conn(struct device *dev, const char *conn)
{
struct cec_notifier *n;

mutex_lock(&cec_notifiers_lock);
list_for_each_entry(n, &cec_notifiers, head) {
- if (n->dev == dev) {
+ if (n->dev == dev &&
+ (!conn || !strcmp(n->conn, conn))) {
kref_get(&n->kref);
mutex_unlock(&cec_notifiers_lock);
return n;
@@ -46,6 +48,8 @@ struct cec_notifier *cec_notifier_get(struct device *dev)
if (!n)
goto unlock;
n->dev = dev;
+ if (conn)
+ n->conn = kstrdup(conn, GFP_KERNEL);
n->phys_addr = CEC_PHYS_ADDR_INVALID;
mutex_init(&n->lock);
kref_init(&n->kref);
@@ -54,7 +58,7 @@ struct cec_notifier *cec_notifier_get(struct device *dev)
mutex_unlock(&cec_notifiers_lock);
return n;
}
-EXPORT_SYMBOL_GPL(cec_notifier_get);
+EXPORT_SYMBOL_GPL(cec_notifier_get_conn);

static void cec_notifier_release(struct kref *kref)
{
@@ -62,6 +66,8 @@ static void cec_notifier_release(struct kref *kref)
container_of(kref, struct cec_notifier, kref);

list_del(&n->head);
+ if (n->conn)
+ kfree(n->conn);
kfree(n);
}

diff --git a/include/media/cec-notifier.h b/include/media/cec-notifier.h
index cf0add7..73f92c7 100644
--- a/include/media/cec-notifier.h
+++ b/include/media/cec-notifier.h
@@ -20,6 +20,23 @@ struct cec_notifier;
#if IS_REACHABLE(CONFIG_CEC_CORE) && IS_ENABLED(CONFIG_CEC_NOTIFIER)

/**
+ * cec_notifier_get_conn - find or create a new cec_notifier for the given
+ * device and connector tuple.
+ * @dev: device that sends the events.
+ * @conn: the connector name from which the event occurs
+ *
+ * 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_conn(struct device *dev,
+ const char *conn);
+
+/**
* cec_notifier_get - find or create a new cec_notifier for the given device.
* @dev: device that sends the events.
*
@@ -31,7 +48,10 @@ struct cec_notifier;
*
* Return NULL if the memory could not be allocated.
*/
-struct cec_notifier *cec_notifier_get(struct device *dev);
+static inline struct cec_notifier *cec_notifier_get(struct device *dev)
+{
+ return cec_notifier_get_conn(dev, NULL);
+}

/**
* cec_notifier_put - decrease refcount and delete when the refcount reaches 0.
@@ -85,12 +105,18 @@ void cec_register_cec_notifier(struct cec_adapter *adap,
struct cec_notifier *notifier);

#else
-static inline struct cec_notifier *cec_notifier_get(struct device *dev)
+static inline struct cec_notifier *cec_notifier_get_conn(struct device *dev,
+ const char *conn)
{
/* A non-NULL pointer is expected on success */
return (struct cec_notifier *)0xdeadfeed;
}

+static inline struct cec_notifier *cec_notifier_get(struct device *dev)
+{
+ return cec_notifier_get_conn(dev, NULL);
+}
+
static inline void cec_notifier_put(struct cec_notifier *n)
{
}
--
2.7.4