watchdog: simatic-ipc-wdt: make IO region access of one model muxed

The IO region used for the watchdog also hold CMOS battery monitoring
information. Make the access muxed so that a hwmon driver can use the
region as well.
Signed-off-by: Henning Schild <henning.schild@siemens.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230706154831.19100-2-henning.schild@siemens.comReviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/watchdog/simatic-ipc-wdt.c

@@ -155,9 +155,8 @@ static int simatic_ipc_wdt_probe(struct platform_device *pdev)
 
 	switch (plat->devmode) {
 	case SIMATIC_IPC_DEVICE_227E:
-		if (!devm_request_region(dev, gp_status_reg_227e_res.start,
-					 resource_size(&gp_status_reg_227e_res),
-					 KBUILD_MODNAME)) {
+		res = &gp_status_reg_227e_res;
+		if (!request_muxed_region(res->start, resource_size(res), res->name)) {
 			dev_err(dev,
 				"Unable to register IO resource at %pR\n",
 				&gp_status_reg_227e_res);
@@ -210,6 +209,10 @@ static int simatic_ipc_wdt_probe(struct platform_device *pdev)
 	if (wdd_data.bootstatus)
 		dev_warn(dev, "last reboot caused by watchdog reset\n");
 
+	if (plat->devmode == SIMATIC_IPC_DEVICE_227E)
+		release_region(gp_status_reg_227e_res.start,
+			       resource_size(&gp_status_reg_227e_res));
+
 	watchdog_set_nowayout(&wdd_data, nowayout);
 	watchdog_stop_on_reboot(&wdd_data);
 	return devm_watchdog_register_device(dev, &wdd_data);