[PATCH RFC 3/6] iio: core: Add cleanup.h support for iio_device_claim_*()

[Kurt Borja <kuurtb@gmail.com>]

Add guard() and ACQUIRE() support for iio_device_claim_*() lock.

This involves exporting iio_device_{claim, release}() wrappers to define
a general GUARD class, and then defining the _direct and _buffer
conditional ones.

Suggested-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
 drivers/iio/industrialio-core.c | 12 ++++++++++++
 include/linux/iio/iio.h         | 20 ++++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index adf0142d0300..da090c993fe8 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -2171,6 +2171,18 @@ int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
 }
 EXPORT_SYMBOL_GPL(__devm_iio_device_register);
 
+void __iio_device_claim(struct iio_dev *indio_dev)
+{
+	mutex_lock(&to_iio_dev_opaque(indio_dev)->mlock);
+}
+EXPORT_SYMBOL_GPL(__iio_device_claim);
+
+void __iio_device_release(struct iio_dev *indio_dev)
+{
+	mutex_unlock(&to_iio_dev_opaque(indio_dev)->mlock);
+}
+EXPORT_SYMBOL_GPL(__iio_device_release);
+
 /**
  * __iio_device_claim_direct - Keep device in direct mode
  * @indio_dev:	the iio_dev associated with the device
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index 27da9af67c47..472b13ec28d3 100644
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -10,6 +10,7 @@
 #include <linux/align.h>
 #include <linux/device.h>
 #include <linux/cdev.h>
+#include <linux/cleanup.h>
 #include <linux/compiler_types.h>
 #include <linux/minmax.h>
 #include <linux/slab.h>
@@ -661,9 +662,23 @@ void iio_device_unregister(struct iio_dev *indio_dev);
 int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
 			       struct module *this_mod);
 int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp);
+void __iio_device_claim(struct iio_dev *indio_dev);
+void __iio_device_release(struct iio_dev *indio_dev);
 bool __iio_device_claim_direct(struct iio_dev *indio_dev);
 void __iio_device_release_direct(struct iio_dev *indio_dev);
 
+static inline void iio_device_claim(struct iio_dev *indio_dev)
+	__acquires(indio_dev)
+{
+	__iio_device_claim(indio_dev);
+}
+
+static inline void iio_device_release(struct iio_dev *indio_dev)
+	__releases(indio_dev)
+{
+	__iio_device_release(indio_dev);
+}
+
 /*
  * Helper functions that allow claim and release of direct mode
  * in a fashion that doesn't generate many false positives from sparse.
@@ -690,6 +705,11 @@ static inline void iio_device_release_direct(struct iio_dev *indio_dev)
 bool iio_device_claim_buffer(struct iio_dev *indio_dev);
 void iio_device_release_buffer(struct iio_dev *indio_dev);
 
+DEFINE_GUARD(iio_device_claim, struct iio_dev *, iio_device_claim(_T),
+	     iio_device_release(_T));
+DEFINE_GUARD_COND(iio_device_claim, _buffer, iio_device_claim_buffer(_T));
+DEFINE_GUARD_COND(iio_device_claim, _direct, iio_device_claim_direct(_T));
+
 extern const struct bus_type iio_bus_type;
 
 /**

-- 
2.52.0