iio: add resource managed triggered buffer init helpers

Add resource managed devm_iio_triggered_buffer_setup() and
devm_iio_triggered_buffer_cleanup() to automatically clean up triggered
buffers setup by IIO drivers, thus leading to simplified IIO drivers code.

Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Documentation/driver-model/devres.txt

@@ -266,6 +266,8 @@ IIO
   devm_iio_device_unregister()
   devm_iio_kfifo_allocate()
   devm_iio_kfifo_free()
+  devm_iio_triggered_buffer_setup()
+  devm_iio_triggered_buffer_cleanup()
   devm_iio_trigger_alloc()
   devm_iio_trigger_free()
   devm_iio_trigger_register()

drivers/iio/buffer/industrialio-triggered-buffer.c

@@ -98,6 +98,48 @@ void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev)
 }
 EXPORT_SYMBOL(iio_triggered_buffer_cleanup);
 
+static void devm_iio_triggered_buffer_clean(struct device *dev, void *res)
+{
+	iio_triggered_buffer_cleanup(*(struct iio_dev **)res);
+}
+
+int devm_iio_triggered_buffer_setup(struct device *dev,
+				    struct iio_dev *indio_dev,
+				    irqreturn_t (*h)(int irq, void *p),
+				    irqreturn_t (*thread)(int irq, void *p),
+				    const struct iio_buffer_setup_ops *ops)
+{
+	struct iio_dev **ptr;
+	int ret;
+
+	ptr = devres_alloc(devm_iio_triggered_buffer_clean, sizeof(*ptr),
+			   GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	*ptr = indio_dev;
+
+	ret = iio_triggered_buffer_setup(indio_dev, h, thread, ops);
+	if (!ret)
+		devres_add(dev, ptr);
+	else
+		devres_free(ptr);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devm_iio_triggered_buffer_setup);
+
+void devm_iio_triggered_buffer_cleanup(struct device *dev,
+				       struct iio_dev *indio_dev)
+{
+	int rc;
+
+	rc = devres_release(dev, devm_iio_triggered_buffer_clean,
+			    devm_iio_device_match, indio_dev);
+	WARN_ON(rc);
+}
+EXPORT_SYMBOL_GPL(devm_iio_triggered_buffer_cleanup);
+
 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers");
 MODULE_LICENSE("GPL");

drivers/iio/industrialio-core.c

@@ -1309,7 +1309,7 @@ static void devm_iio_device_release(struct device *dev, void *res)
 	iio_device_free(*(struct iio_dev **)res);
 }
 
-static int devm_iio_device_match(struct device *dev, void *res, void *data)
+int devm_iio_device_match(struct device *dev, void *res, void *data)
 {
 	struct iio_dev **r = res;
 	if (!r || !*r) {
@@ -1318,6 +1318,7 @@ static int devm_iio_device_match(struct device *dev, void *res, void *data)
 	}
 	return *r == data;
 }
+EXPORT_SYMBOL_GPL(devm_iio_device_match);
 
 /**
  * devm_iio_device_alloc - Resource-managed iio_device_alloc()

include/linux/iio/iio.h

@@ -644,6 +644,7 @@ static inline struct iio_dev *iio_priv_to_dev(void *priv)
 }
 
 void iio_device_free(struct iio_dev *indio_dev);
+int devm_iio_device_match(struct device *dev, void *res, void *data);
 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv);
 void devm_iio_device_free(struct device *dev, struct iio_dev *indio_dev);
 struct iio_trigger *devm_iio_trigger_alloc(struct device *dev,

include/linux/iio/triggered_buffer.h

@@ -12,4 +12,12 @@ int iio_triggered_buffer_setup(struct iio_dev *indio_dev,
 	const struct iio_buffer_setup_ops *setup_ops);
 void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev);
 
+int devm_iio_triggered_buffer_setup(struct device *dev,
+				    struct iio_dev *indio_dev,
+				    irqreturn_t (*h)(int irq, void *p),
+				    irqreturn_t (*thread)(int irq, void *p),
+				    const struct iio_buffer_setup_ops *ops);
+void devm_iio_triggered_buffer_cleanup(struct device *dev,
+				       struct iio_dev *indio_dev);
+
 #endif