V4L/DVB (13103): create a standard method for dvb adapter drivers to override frontend ioctls

Signed-off-by: Michael Krufky <mkrufky@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/drivers/media/dvb/dvb-core/dvbdev.h b/drivers/media/dvb/dvb-core/dvbdev.h
index 01fc704..f7b499d 100644
--- a/drivers/media/dvb/dvb-core/dvbdev.h
+++ b/drivers/media/dvb/dvb-core/dvbdev.h
@@ -54,6 +54,8 @@
 	module_param_array(adapter_nr, short, NULL, 0444); \
 	MODULE_PARM_DESC(adapter_nr, "DVB adapter numbers")
 
+struct dvb_frontend;
+
 struct dvb_adapter {
 	int num;
 	struct list_head list_head;
@@ -69,6 +71,32 @@ struct dvb_adapter {
 	int mfe_shared;			/* indicates mutually exclusive frontends */
 	struct dvb_device *mfe_dvbdev;	/* frontend device in use */
 	struct mutex mfe_lock;		/* access lock for thread creation */
+
+	/* Allow the adapter/bridge driver to perform an action before and/or
+	 * after the core handles an ioctl:
+	 *
+	 * DVB_FE_IOCTL_PRE indicates that the ioctl has not yet been handled.
+	 * DVB_FE_IOCTL_POST indicates that the ioctl has been handled.
+	 *
+	 * When DVB_FE_IOCTL_PRE is passed to the callback as the stage arg:
+	 *
+	 * return 0 to allow dvb-core to handle the ioctl.
+	 * return a positive int to prevent dvb-core from handling the ioctl,
+	 * 	and exit without error.
+	 * return a negative int to prevent dvb-core from handling the ioctl,
+	 * 	and return that value as an error.
+	 *
+	 * When DVB_FE_IOCTL_POST is passed to the callback as the stage arg:
+	 *
+	 * return 0 to allow the dvb_frontend ioctl handler to exit normally.
+	 * return a negative int to cause the dvb_frontend ioctl handler to
+	 * 	return that value as an error.
+	 */
+#define DVB_FE_IOCTL_PRE 0
+#define DVB_FE_IOCTL_POST 1
+	int (*fe_ioctl_override)(struct dvb_frontend *fe,
+				 unsigned int cmd, void *parg,
+				 unsigned int stage);
 };