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>

drivers/media/dvb/dvb-core/dvb_frontend.c

@@ -1712,7 +1712,18 @@ static int dvb_frontend_ioctl_legacy(struct inode *inode, struct file *file,
 	struct dvb_device *dvbdev = file->private_data;
 	struct dvb_frontend *fe = dvbdev->priv;
 	struct dvb_frontend_private *fepriv = fe->frontend_priv;
-	int err = -EOPNOTSUPP;
+	int cb_err, err = -EOPNOTSUPP;
+
+	if (fe->dvb->fe_ioctl_override) {
+		cb_err = fe->dvb->fe_ioctl_override(fe, cmd, parg,
+						    DVB_FE_IOCTL_PRE);
+		if (cb_err < 0)
+			return cb_err;
+		if (cb_err > 0)
+			return 0;
+		/* fe_ioctl_override returning 0 allows
+		 * dvb-core to continue handling the ioctl */
+	}
 
 	switch (cmd) {
 	case FE_GET_INFO: {
@@ -1978,6 +1989,13 @@ static int dvb_frontend_ioctl_legacy(struct inode *inode, struct file *file,
 		break;
 	};
 
+	if (fe->dvb->fe_ioctl_override) {
+		cb_err = fe->dvb->fe_ioctl_override(fe, cmd, parg,
+						    DVB_FE_IOCTL_POST);
+		if (cb_err < 0)
+			return cb_err;
+	}
+
 	return err;
 }
 

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);
 };
 
 

drivers/media/video/cx23885/cx23885-dvb.c

@@ -904,7 +904,7 @@ static int dvb_register(struct cx23885_tsport *port)
 
 	/* register everything */
 	ret = videobuf_dvb_register_bus(&port->frontends, THIS_MODULE, port,
-		&dev->pci->dev, adapter_nr, 0);
+					&dev->pci->dev, adapter_nr, 0, NULL);
 
 	/* init CI & MAC */
 	switch (dev->board) {

drivers/media/video/cx88/cx88-dvb.c

@@ -1174,7 +1174,7 @@ static int dvb_register(struct cx8802_dev *dev)
 
 	/* register everything */
 	return videobuf_dvb_register_bus(&dev->frontends, THIS_MODULE, dev,
-		&dev->pci->dev, adapter_nr, mfe_shared);
+					 &dev->pci->dev, adapter_nr, mfe_shared, NULL);
 
 frontend_detach:
 	core->gate_ctrl = NULL;

drivers/media/video/saa7134/saa7134-dvb.c

@@ -1574,7 +1574,7 @@ static int dvb_init(struct saa7134_dev *dev)
 
 	/* register everything else */
 	ret = videobuf_dvb_register_bus(&dev->frontends, THIS_MODULE, dev,
-		&dev->pci->dev, adapter_nr, 0);
+					&dev->pci->dev, adapter_nr, 0, NULL);
 
 	/* this sequence is necessary to make the tda1004x load its firmware
 	 * and to enter analog mode of hybrid boards

drivers/media/video/videobuf-dvb.c

@@ -139,7 +139,9 @@ static int videobuf_dvb_register_adapter(struct videobuf_dvb_frontends *fe,
 			  struct device *device,
 			  char *adapter_name,
 			  short *adapter_nr,
-			  int mfe_shared)
+			  int mfe_shared,
+			  int (*fe_ioctl_override)(struct dvb_frontend *,
+					unsigned int, void *, unsigned int))
 {
 	int result;
 
@@ -154,6 +156,7 @@ static int videobuf_dvb_register_adapter(struct videobuf_dvb_frontends *fe,
 	}
 	fe->adapter.priv = adapter_priv;
 	fe->adapter.mfe_shared = mfe_shared;
+	fe->adapter.fe_ioctl_override = fe_ioctl_override;
 
 	return result;
 }
@@ -253,7 +256,9 @@ int videobuf_dvb_register_bus(struct videobuf_dvb_frontends *f,
 			  void *adapter_priv,
 			  struct device *device,
 			  short *adapter_nr,
-			  int mfe_shared)
+			  int mfe_shared,
+			  int (*fe_ioctl_override)(struct dvb_frontend *,
+					unsigned int, void *, unsigned int))
 {
 	struct list_head *list, *q;
 	struct videobuf_dvb_frontend *fe;
@@ -267,7 +272,7 @@ int videobuf_dvb_register_bus(struct videobuf_dvb_frontends *f,
 
 	/* Bring up the adapter */
 	res = videobuf_dvb_register_adapter(f, module, adapter_priv, device,
-		fe->dvb.name, adapter_nr, mfe_shared);
+		fe->dvb.name, adapter_nr, mfe_shared, fe_ioctl_override);
 	if (res < 0) {
 		printk(KERN_WARNING "videobuf_dvb_register_adapter failed (errno = %d)\n", res);
 		return res;

include/media/videobuf-dvb.h

@@ -42,7 +42,9 @@ int videobuf_dvb_register_bus(struct videobuf_dvb_frontends *f,
 			  void *adapter_priv,
 			  struct device *device,
 			  short *adapter_nr,
-			  int mfe_shared);
+			  int mfe_shared,
+			  int (*fe_ioctl_override)(struct dvb_frontend *,
+					unsigned int, void *, unsigned int));
 
 void videobuf_dvb_unregister_bus(struct videobuf_dvb_frontends *f);