Merge tag 'hwmon-for-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull hwmon updates from Guenter Roeck:

 - Add driver for Intersil ISL68137 PWM Controller

 - Add driver for Lochnagar 2

 - Add driver for Infineon IR38064 Voltage Regulator

 - Add support for TMP75B to lm75 driver

 - Convert documentation to ReST format

 - Use request_muxed_region for Super-IO accesses in several drivers

 - Add 'samples' attribute to ABI, and start using it

 - Add support for custom sysfs attributes to pmbus drivers (used in
   ISL68137 driver)

 - Introduce HWMON_CHANNEL_INFO macro

 - Automated changes:
      - Use permission specific [SENSOR_][DEVICE_]ATTR variants
      - Fix build warnings due to unused of_device_id structures
      - Use HWMON_CHANNEL_INFO macro

 - Various minor improvements and fixes

* tag 'hwmon-for-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging: (125 commits)
  hwmon: (lm75) Add support for TMP75B
  dt-bindings: hwmon: Add tmp75b to lm75.txt
  hwmon: (s3c) Use dev_get_drvdata()
  hwmon: (max6650) Drop call to thermal_cdev_update
  docs: hwmon: remove the extension from .rst files
  docs: hwmon: convert three docs to ReST format
  hwmon: (max6650) add thermal cooling device capability
  hwmon: (ina3221) Add voltage conversion time settings
  hwmon: (ina3221) Do not read-back to cache reg_config
  docs: hwmon: Add an index file and rename docs to *.rst
  docs: hwmon: convert remaining files to ReST format
  docs: hwmon: misc files: convert to ReST format
  docs: hwmon: pmbus files: convert to ReST format
  docs: hwmon: k8temp, w83793: convert to ReST format
  docs: hwmon: da9052, da9055: convert to ReST format
  docs: hwmon: wm831x, wm8350: convert to ReST format
  docs: hwmon: dme1737, vt1211: convert to ReST format
  docs: hwmon: ads1015: convert to ReST format
  docs: hwmon: asc7621: convert to ReST format
  docs: hwmon: ibmpowernv: convert to ReST format
  ...

1 files changed, 11 insertions, 2 deletions

diff --git a/drivers/hwmon/smsc47b397.c b/drivers/hwmon/smsc47b397.c
index c0775084dde0..60e193f2e970 100644
--- a/drivers/hwmon/smsc47b397.c
+++ b/drivers/hwmon/smsc47b397.c
@@ -72,14 +72,19 @@ static inline void superio_select(int ld)
 	superio_outb(0x07, ld);
 }
 
-static inline void superio_enter(void)
+static inline int superio_enter(void)
 {
+	if (!request_muxed_region(REG, 2, DRVNAME))
+		return -EBUSY;
+
 	outb(0x55, REG);
+	return 0;
 }
 
 static inline void superio_exit(void)
 {
 	outb(0xAA, REG);
+	release_region(REG, 2);
 }
 
 #define SUPERIO_REG_DEVID	0x20
@@ -300,8 +305,12 @@ static int __init smsc47b397_find(void)
 	u8 id, rev;
 	char *name;
 	unsigned short addr;
+	int err;
+
+	err = superio_enter();
+	if (err)
+		return err;
 
-	superio_enter();
 	id = force_id ? force_id : superio_inb(SUPERIO_REG_DEVID);
 
 	switch (id) {