[PATCH v4 2/2] Use "request_muxed_region" in it87 hwmon drivers

[Nat Gurumoorthy <natg@google.com>]

02 - Chages to hwmon it87 driver to use "request_muxed_region"
Serialize access to the hardware by using "request_muxed_region" macro defined
by Alan Cox. Call to this macro will hold off the requestor if the resource is
currently busy.

Signed-off-by: Nat Gurumoorthy <natg@google.com>
---

diff --git a/drivers/hwmon/it87.c b/drivers/hwmon/it87.c
index 316b648..1dc04d4 100644
--- a/drivers/hwmon/it87.c
+++ b/drivers/hwmon/it87.c
@@ -111,6 +111,9 @@ superio_select(int ldn)
 static inline void
 superio_enter(void)
 {
+	while (!request_muxed_region(REG, 2, DRVNAME))
+		continue;
+
 	outb(0x87, REG);
 	outb(0x01, REG);
 	outb(0x55, REG);
@@ -122,6 +125,7 @@ superio_exit(void)
 {
 	outb(0x02, REG);
 	outb(0x02, VAL);
+	release_region(REG, 2);
 }
 
 /* Logical device 4 registers */
-- 
1.7.3.1