[PATCH 7.0.y 1/2] hwmon: (pmbus) Add support for guarded PMBus lock

[Sasha Levin <sashal@kernel.org>]

From: Guenter Roeck <linux@roeck-us.net>

[ Upstream commit 1814f4d3ff358277a5b6957e7f133c2812dc80ec ]

Add support for guard(pmbus_lock)() and scoped_guard(pmbus_lock)()
to be able to simplify the PMBus code.

Also introduce pmbus_lock() as pre-requisite for supporting
guard().

Reviewed-by: Sanman Pradhan <psanman@juniper.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Stable-dep-of: 4e4af55aaca7 ("hwmon: (pmbus/adm1266) serialize sequencer_state debugfs read with pmbus_lock")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/hwmon/pmbus/pmbus.h      | 5 +++++
 drivers/hwmon/pmbus/pmbus_core.c | 8 ++++++++
 2 files changed, 13 insertions(+)

diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
index d2e9bfb5320fc..e499cdae9442c 100644
--- a/drivers/hwmon/pmbus/pmbus.h
+++ b/drivers/hwmon/pmbus/pmbus.h
@@ -10,6 +10,7 @@
 #define PMBUS_H
 
 #include <linux/bitops.h>
+#include <linux/cleanup.h>
 #include <linux/regulator/driver.h>
 
 /*
@@ -563,7 +564,11 @@ int pmbus_get_fan_rate_device(struct i2c_client *client, int page, int id,
 int pmbus_get_fan_rate_cached(struct i2c_client *client, int page, int id,
 			      enum pmbus_fan_mode mode);
 int pmbus_lock_interruptible(struct i2c_client *client);
+void pmbus_lock(struct i2c_client *client);
 void pmbus_unlock(struct i2c_client *client);
+
+DEFINE_GUARD(pmbus_lock, struct i2c_client *, pmbus_lock(_T), pmbus_unlock(_T))
+
 int pmbus_update_fan(struct i2c_client *client, int page, int id,
 		     u8 config, u8 mask, u16 command);
 struct dentry *pmbus_get_debugfs_dir(struct i2c_client *client);
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 572be3ebc03df..7150f12d26300 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -3871,6 +3871,14 @@ struct dentry *pmbus_get_debugfs_dir(struct i2c_client *client)
 }
 EXPORT_SYMBOL_NS_GPL(pmbus_get_debugfs_dir, "PMBUS");
 
+void pmbus_lock(struct i2c_client *client)
+{
+	struct pmbus_data *data = i2c_get_clientdata(client);
+
+	mutex_lock(&data->update_lock);
+}
+EXPORT_SYMBOL_NS_GPL(pmbus_lock, "PMBUS");
+
 int pmbus_lock_interruptible(struct i2c_client *client)
 {
 	struct pmbus_data *data = i2c_get_clientdata(client);
-- 
2.53.0