On Fri, 17 Dec 2021 18:52:00 +0100
"Rafael J. Wysocki" [off-list ref] wrote:

On Fri, Dec 3, 2021 at 10:24 PM Anand Ashok Dumbre
[off-list ref] wrote:

quoted

This patch introduces a new helper routine - fwnode_iomap(), which
allows to map the memory mapped IO for a given device node.

This implementation does not cover the ACPI case and may be expanded
in the future. The main purpose here is to be able to develop resource
provider agnostic drivers.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Anand Ashok Dumbre <redacted>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/base/property.c  | 16 ++++++++++++++++
 include/linux/property.h |  2 ++
 2 files changed, 18 insertions(+)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index f1f35b48ab8b..ed4470410030 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c

@@ -958,6 +958,22 @@ int fwnode_irq_get(const struct fwnode_handle *fwnode, unsigned int index)
 }
 EXPORT_SYMBOL(fwnode_irq_get);

+/**
+ * fwnode_iomap - Maps the memory mapped IO for a given fwnode
+ * @fwnode:    Pointer to the firmware node
+ * @index:     Index of the IO range
+ *
+ * Returns a pointer to the mapped memory.
+ */
+void __iomem *fwnode_iomap(struct fwnode_handle *fwnode, int index)
+{
+       if (IS_ENABLED(CONFIG_OF_ADDRESS) && is_of_node(fwnode))
+               return of_iomap(to_of_node(fwnode), index);
+
+       return NULL;
+}
+EXPORT_SYMBOL(fwnode_iomap);  

So why is this EXPORT_SYMBOL() and not EXPORT_SYMBOL_GPL()?

Good question.  I'm guessing this is because of_iomap is EXPORT_SYMBOL()
and we don't want to discourage use of this function in preference to it.

Series applied to the togreg branch of iio.git but initially pushed out
as testing to let 0-day see if it can find anything we broke.

Note I can still rebase if people would prefer _GPL() so feel free to
discuss further. +CC Rob Herring and DT list.

Thanks,

Jonathan

Other than this I'm not an OF_ expert, but I trust Andy, so with the
above addressed:

Acked-by: Rafael J. Wysocki <redacted>

quoted

+
 /**
  * fwnode_graph_get_next_endpoint - Get next endpoint firmware node
  * @fwnode: Pointer to the parent firmware node

diff --git a/include/linux/property.h b/include/linux/property.h
index 88fa726a76df..6670d5a1ec2a 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h

@@ -122,6 +122,8 @@ void fwnode_handle_put(struct fwnode_handle *fwnode);

 int fwnode_irq_get(const struct fwnode_handle *fwnode, unsigned int index);

+void __iomem *fwnode_iomap(struct fwnode_handle *fwnode, int index);
+
 unsigned int device_get_child_node_count(struct device *dev);

 static inline bool device_property_read_bool(struct device *dev,
--

2.17.1