[media] cec: add CEC_CAP_NEEDS_HPD
Add a new capability CEC_CAP_NEEDS_HPD. If this capability is set
then the hardware can only use CEC if the HDMI Hotplug Detect pin
is high. Such hardware cannot handle the corner case in the CEC specification
where it is possible to transmit messages even if no hotplug signal is
present (needed for some displays that turn off the HPD when in standby,
but still have CEC enabled).
Typically hardware that needs this capability have the HPD wired to the CEC
block, often to a 'power' or 'active' pin.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
diff --git a/drivers/media/cec/cec-api.c b/drivers/media/cec/cec-api.c
index 0860fb4..1359c397 100644
--- a/drivers/media/cec/cec-api.c
+++ b/drivers/media/cec/cec-api.c
@@ -202,7 +202,8 @@ static long cec_transmit(struct cec_adapter *adap, struct cec_fh *fh,
err = -EPERM;
else if (adap->is_configuring)
err = -ENONET;
- else if (!adap->is_configured && msg.msg[0] != 0xf0)
+ else if (!adap->is_configured &&
+ (adap->needs_hpd || msg.msg[0] != 0xf0))
err = -ENONET;
else if (cec_is_busy(adap, fh))
err = -EBUSY;
@@ -521,6 +522,7 @@ static int cec_open(struct inode *inode, struct file *filp)
mutex_lock(&devnode->lock);
if (list_empty(&devnode->fhs) &&
+ !adap->needs_hpd &&
adap->phys_addr == CEC_PHYS_ADDR_INVALID) {
err = adap->ops->adap_enable(adap, true);
if (err) {
@@ -565,6 +567,7 @@ static int cec_release(struct inode *inode, struct file *filp)
mutex_lock(&devnode->lock);
list_del(&fh->list);
if (list_empty(&devnode->fhs) &&
+ !adap->needs_hpd &&
adap->phys_addr == CEC_PHYS_ADDR_INVALID) {
WARN_ON(adap->ops->adap_enable(adap, false));
}