pps: default echo function

A default echo function has been provided so it is no longer an error when
you specify PPS_ECHOASSERT or PPS_ECHOCLEAR without an explicit echo
function.  This allows some code re-use and also makes it easier to write
client drivers since the default echo function does not normally need to
change.

Signed-off-by: James Nuss <jamesnuss@nanometrics.ca>
Reviewed-by: Ben Gardiner <bengardiner@nanometrics.ca>
Acked-by: Rodolfo Giometti <giometti@linux.it>
Cc: Ricardo Martins <rasm@fe.up.pt>
Cc: Alexander Gordeev <lasaine@lvk.cs.msu.su>
Cc: Igor Plyatov <plyatov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/pps/clients/pps-ktimer.c

@@ -51,17 +51,6 @@ static void pps_ktimer_event(unsigned long ptr)
 	mod_timer(&ktimer, jiffies + HZ);
 }
 
-/*
- * The echo function
- */
-
-static void pps_ktimer_echo(struct pps_device *pps, int event, void *data)
-{
-	dev_info(pps->dev, "echo %s %s\n",
-		event & PPS_CAPTUREASSERT ? "assert" : "",
-		event & PPS_CAPTURECLEAR ? "clear" : "");
-}
-
 /*
  * The PPS info struct
  */
@@ -72,7 +61,6 @@ static struct pps_source_info pps_ktimer_info = {
 	.mode		= PPS_CAPTUREASSERT | PPS_OFFSETASSERT |
 			  PPS_ECHOASSERT |
 			  PPS_CANWAIT | PPS_TSFMT_TSPEC,
-	.echo		= pps_ktimer_echo,
 	.owner		= THIS_MODULE,
 };
 

drivers/pps/clients/pps_parport.c

@@ -133,14 +133,6 @@ static void parport_irq(void *handle)
 	return;
 }
 
-/* the PPS echo function */
-static void pps_echo(struct pps_device *pps, int event, void *data)
-{
-	dev_info(pps->dev, "echo %s %s\n",
-		event & PPS_CAPTUREASSERT ? "assert" : "",
-		event & PPS_CAPTURECLEAR ? "clear" : "");
-}
-
 static void parport_attach(struct parport *port)
 {
 	struct pps_client_pp *device;
@@ -151,7 +143,6 @@ static void parport_attach(struct parport *port)
 				  PPS_OFFSETASSERT | PPS_OFFSETCLEAR | \
 				  PPS_ECHOASSERT | PPS_ECHOCLEAR | \
 				  PPS_CANWAIT | PPS_TSFMT_TSPEC,
-		.echo		= pps_echo,
 		.owner		= THIS_MODULE,
 		.dev		= NULL
 	};

drivers/pps/kapi.c

@@ -52,6 +52,14 @@ static void pps_add_offset(struct pps_ktime *ts, struct pps_ktime *offset)
 	ts->sec += offset->sec;
 }
 
+static void pps_echo_client_default(struct pps_device *pps, int event,
+		void *data)
+{
+	dev_info(pps->dev, "echo %s %s\n",
+		event & PPS_CAPTUREASSERT ? "assert" : "",
+		event & PPS_CAPTURECLEAR ? "clear" : "");
+}
+
 /*
  * Exported functions
  */
@@ -80,13 +88,6 @@ struct pps_device *pps_register_source(struct pps_source_info *info,
 		err = -EINVAL;
 		goto pps_register_source_exit;
 	}
-	if ((info->mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)) != 0 &&
-			info->echo == NULL) {
-		pr_err("%s: echo function is not defined\n",
-					info->name);
-		err = -EINVAL;
-		goto pps_register_source_exit;
-	}
 	if ((info->mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) {
 		pr_err("%s: unspecified time format\n",
 					info->name);
@@ -108,6 +109,11 @@ struct pps_device *pps_register_source(struct pps_source_info *info,
 	pps->params.mode = default_params;
 	pps->info = *info;
 
+	/* check for default echo function */
+	if ((pps->info.mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)) &&
+			pps->info.echo == NULL)
+		pps->info.echo = pps_echo_client_default;
+
 	init_waitqueue_head(&pps->queue);
 	spin_lock_init(&pps->lock);