media: cec: add CEC_EVENT_PIN_HPD_LOW/HIGH events

Add support for two new low-level events: PIN_HPD_LOW and PIN_HPD_HIGH.

This is specifically meant for use with the upcoming cec-gpio driver
and makes it possible to trace when the HPD pin changes. Some HDMI
sinks do strange things with the HPD and this makes it easy to debug
this.

Note that this also moves the initialization of a devnode mutex and
list to the allocate_adapter function: if the HPD is high, then as
soon as the HPD interrupt is created an interrupt occurs and
cec_queue_pin_hpd_event() is called which requires that the devnode
mutex and list are initialized.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/drivers/media/cec/cec-core.c b/drivers/media/cec/cec-core.c
index 648136e5..e3a1fb6 100644
--- a/drivers/media/cec/cec-core.c
+++ b/drivers/media/cec/cec-core.c
@@ -112,10 +112,6 @@ static int __must_check cec_devnode_register(struct cec_devnode *devnode,
 	int minor;
 	int ret;
 
-	/* Initialization */
-	INIT_LIST_HEAD(&devnode->fhs);
-	mutex_init(&devnode->lock);
-
 	/* Part 1: Find a free minor number */
 	mutex_lock(&cec_devnode_lock);
 	minor = find_next_zero_bit(cec_devnode_nums, CEC_NUM_DEVICES, 0);
@@ -242,6 +238,10 @@ struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops,
 	INIT_LIST_HEAD(&adap->wait_queue);
 	init_waitqueue_head(&adap->kthread_waitq);
 
+	/* adap->devnode initialization */
+	INIT_LIST_HEAD(&adap->devnode.fhs);
+	mutex_init(&adap->devnode.lock);
+
 	adap->kthread = kthread_run(cec_thread_func, adap, "cec-%s", name);
 	if (IS_ERR(adap->kthread)) {
 		pr_err("cec-%s: kernel_thread() failed\n", name);