device property: Allow const parameter to dev_fwnode()

commit b295d484b97081feba72b071ffcb72fb4638ccfd upstream.

It's not fully correct to take a const parameter pointer to a struct
and return a non-const pointer to a member of that struct.

Instead, introduce a const version of the dev_fwnode() API which takes
and returns const pointers and use it where it's applicable.

With this, convert dev_fwnode() to be a macro wrapper on top of const
and non-const APIs that chooses one based on the type.

Suggested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Fixes: aade55c86033 ("device property: Add const qualifier to device_get_match_data() parameter")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Link: https://lore.kernel.org/r/20221004092129.19412-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/base/property.c b/drivers/base/property.c
index 2ed844650328cbba88f55bb3747512c864e0c174..21f4184db42fc2eb1f71d42ba493dbf225aa0a33 100644 (file)
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -18,12 +18,19 @@
 #include <linux/etherdevice.h>
 #include <linux/phy.h>
 
-struct fwnode_handle *dev_fwnode(const struct device *dev)
+struct fwnode_handle *__dev_fwnode(struct device *dev)
 {
        return IS_ENABLED(CONFIG_OF) && dev->of_node ?
                of_fwnode_handle(dev->of_node) : dev->fwnode;
 }
-EXPORT_SYMBOL_GPL(dev_fwnode);
+EXPORT_SYMBOL_GPL(__dev_fwnode);
+
+const struct fwnode_handle *__dev_fwnode_const(const struct device *dev)
+{
+       return IS_ENABLED(CONFIG_OF) && dev->of_node ?
+               of_fwnode_handle(dev->of_node) : dev->fwnode;
+}
+EXPORT_SYMBOL_GPL(__dev_fwnode_const);
 
 /**
  * device_property_present - check if a property of a device is present

diff --git a/include/linux/property.h b/include/linux/property.h
index 1bd1e4ada7e3a4b6afb162ed5e38b7eccf0620b8..fe2092e39aedbd34e5fcb804ca41e9279f771cf7 100644 (file)
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -31,7 +31,12 @@ enum dev_dma_attr {
        DEV_DMA_COHERENT,
 };
 
-struct fwnode_handle *dev_fwnode(const struct device *dev);
+const struct fwnode_handle *__dev_fwnode_const(const struct device *dev);
+struct fwnode_handle *__dev_fwnode(struct device *dev);
+#define dev_fwnode(dev)                                                        \
+       _Generic((dev),                                                 \
+                const struct device *: __dev_fwnode_const,     \
+                struct device *: __dev_fwnode)(dev)
 
 bool device_property_present(struct device *dev, const char *propname);
 int device_property_read_u8_array(struct device *dev, const char *propname,