pps: using ERR_PTR instead of NULL while pps_register_source fails

pps_register_source() has keeps error codes in a local variable,
but it does not make use of the code. This patch let it return
the errcode in case of failure.
Suggested-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Rodolfo Giometti <giometti@enneenne.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/pps/clients/pps-gpio.c

@@ -158,10 +158,10 @@ static int pps_gpio_probe(struct platform_device *pdev)
 	if (data->capture_clear)
 		pps_default_params |= PPS_CAPTURECLEAR | PPS_OFFSETCLEAR;
 	data->pps = pps_register_source(&data->info, pps_default_params);
-	if (data->pps == NULL) {
+	if (IS_ERR(data->pps)) {
 		dev_err(&pdev->dev, "failed to register IRQ %d as PPS source\n",
 			data->irq);
-		return -EINVAL;
+		return PTR_ERR(data->pps);
 	}
 
 	/* register IRQ interrupt handler */

drivers/pps/clients/pps-ktimer.c

@@ -80,9 +80,9 @@ static int __init pps_ktimer_init(void)
 {
 	pps = pps_register_source(&pps_ktimer_info,
 				PPS_CAPTUREASSERT | PPS_OFFSETASSERT);
-	if (pps == NULL) {
+	if (IS_ERR(pps)) {
 		pr_err("cannot register PPS source\n");
-		return -ENOMEM;
+		return PTR_ERR(pps);
 	}
 
 	timer_setup(&ktimer, pps_ktimer_event, 0);

drivers/pps/clients/pps-ldisc.c

@@ -72,9 +72,9 @@ static int pps_tty_open(struct tty_struct *tty)
 
 	pps = pps_register_source(&info, PPS_CAPTUREBOTH | \
 				PPS_OFFSETASSERT | PPS_OFFSETCLEAR);
-	if (pps == NULL) {
+	if (IS_ERR(pps)) {
 		pr_err("cannot register PPS source \"%s\"\n", info.path);
-		return -ENOMEM;
+		return PTR_ERR(pps);
 	}
 	pps->lookup_cookie = tty;
 

drivers/pps/clients/pps_parport.c

@@ -179,7 +179,7 @@ static void parport_attach(struct parport *port)
 
 	device->pps = pps_register_source(&info,
 			PPS_CAPTUREBOTH | PPS_OFFSETASSERT | PPS_OFFSETCLEAR);
-	if (device->pps == NULL) {
+	if (IS_ERR(device->pps)) {
 		pr_err("couldn't register PPS source\n");
 		goto err_release_dev;
 	}

drivers/pps/kapi.c

@@ -72,7 +72,8 @@ static void pps_echo_client_default(struct pps_device *pps, int event,
  * source is described by info's fields and it will have, as default PPS
  * parameters, the ones specified into default_params.
  *
- * The function returns, in case of success, the PPS device. Otherwise NULL.
+ * The function returns, in case of success, the PPS device. Otherwise
+ * ERR_PTR(errno).
  */
 
 struct pps_device *pps_register_source(struct pps_source_info *info,
@@ -135,7 +136,7 @@ struct pps_device *pps_register_source(struct pps_source_info *info,
 pps_register_source_exit:
 	pr_err("%s: unable to register source\n", info->name);
 
-	return NULL;
+	return ERR_PTR(err);
 }
 EXPORT_SYMBOL(pps_register_source);