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Sender: Guenter Roeck <groeck7@gmail.com>
From:   Guenter Roeck <linux@roeck-us.net>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Daniel Scally <djrscally@gmail.com>,
        Heikki Krogerus <heikki.krogerus@linux.intel.com>,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
        "Rafael J . Wysocki" <rafael@kernel.org>,
        linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org,
        Guenter Roeck <linux@roeck-us.net>,
        Chris Packham <chris.packham@alliedtelesis.co.nz>
Subject: [PATCH] device property: make device_property functions take const device *
Date:   Wed, 19 Apr 2023 09:41:27 -0700
Message-Id: <20230419164127.3773278-1-linux@roeck-us.net>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

device_property functions do not modify the device pointer passed to them.
The underlying of_device and fwnode_ functions actually already take
const * arguments. Mark the parameter constant to simplify conversion
from of_property to device_property functions, and to let the calling code
use const device pointers where possible.

Cc: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
Found by Chris when trying to convert a driver from of_property_ to
device_property_ functions. I don't really see a reason why the device
parameter to device_property functions should not be const.
Please let me know if I am missing sonething.

 drivers/base/property.c  | 16 ++++++++--------
 include/linux/property.h | 36 ++++++++++++++++++------------------
 2 files changed, 26 insertions(+), 26 deletions(-)

diff --git a/drivers/base/property.c b/drivers/base/property.c
index 083a95791d3b..21d7a5d13e05 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -38,7 +38,7 @@ EXPORT_SYMBOL_GPL(__dev_fwnode_const);
  *
  * Check if property @propname is present in the device firmware description.
  */
-bool device_property_present(struct device *dev, const char *propname)
+bool device_property_present(const struct device *dev, const char *propname)
 {
 	return fwnode_property_present(dev_fwnode(dev), propname);
 }
@@ -86,7 +86,7 @@ EXPORT_SYMBOL_GPL(fwnode_property_present);
  *	   %-EOVERFLOW if the size of the property is not as expected.
  *	   %-ENXIO if no suitable firmware interface is present.
  */
-int device_property_read_u8_array(struct device *dev, const char *propname,
+int device_property_read_u8_array(const struct device *dev, const char *propname,
 				  u8 *val, size_t nval)
 {
 	return fwnode_property_read_u8_array(dev_fwnode(dev), propname, val, nval);
@@ -114,7 +114,7 @@ EXPORT_SYMBOL_GPL(device_property_read_u8_array);
  *	   %-EOVERFLOW if the size of the property is not as expected.
  *	   %-ENXIO if no suitable firmware interface is present.
  */
-int device_property_read_u16_array(struct device *dev, const char *propname,
+int device_property_read_u16_array(const struct device *dev, const char *propname,
 				   u16 *val, size_t nval)
 {
 	return fwnode_property_read_u16_array(dev_fwnode(dev), propname, val, nval);
@@ -142,7 +142,7 @@ EXPORT_SYMBOL_GPL(device_property_read_u16_array);
  *	   %-EOVERFLOW if the size of the property is not as expected.
  *	   %-ENXIO if no suitable firmware interface is present.
  */
-int device_property_read_u32_array(struct device *dev, const char *propname,
+int device_property_read_u32_array(const struct device *dev, const char *propname,
 				   u32 *val, size_t nval)
 {
 	return fwnode_property_read_u32_array(dev_fwnode(dev), propname, val, nval);
@@ -170,7 +170,7 @@ EXPORT_SYMBOL_GPL(device_property_read_u32_array);
  *	   %-EOVERFLOW if the size of the property is not as expected.
  *	   %-ENXIO if no suitable firmware interface is present.
  */
-int device_property_read_u64_array(struct device *dev, const char *propname,
+int device_property_read_u64_array(const struct device *dev, const char *propname,
 				   u64 *val, size_t nval)
 {
 	return fwnode_property_read_u64_array(dev_fwnode(dev), propname, val, nval);
@@ -198,7 +198,7 @@ EXPORT_SYMBOL_GPL(device_property_read_u64_array);
  *	   %-EOVERFLOW if the size of the property is not as expected.
  *	   %-ENXIO if no suitable firmware interface is present.
  */
-int device_property_read_string_array(struct device *dev, const char *propname,
+int device_property_read_string_array(const struct device *dev, const char *propname,
 				      const char **val, size_t nval)
 {
 	return fwnode_property_read_string_array(dev_fwnode(dev), propname, val, nval);
@@ -220,7 +220,7 @@ EXPORT_SYMBOL_GPL(device_property_read_string_array);
  *	   %-EPROTO or %-EILSEQ if the property type is not a string.
  *	   %-ENXIO if no suitable firmware interface is present.
  */
-int device_property_read_string(struct device *dev, const char *propname,
+int device_property_read_string(const struct device *dev, const char *propname,
 				const char **val)
 {
 	return fwnode_property_read_string(dev_fwnode(dev), propname, val);
@@ -242,7 +242,7 @@ EXPORT_SYMBOL_GPL(device_property_read_string);
  *	   %-EPROTO if the property is not an array of strings,
  *	   %-ENXIO if no suitable firmware interface is present.
  */
-int device_property_match_string(struct device *dev, const char *propname,
+int device_property_match_string(const struct device *dev, const char *propname,
 				 const char *string)
 {
 	return fwnode_property_match_string(dev_fwnode(dev), propname, string);
diff --git a/include/linux/property.h b/include/linux/property.h
index 0a29db15ff34..66fe73ee430d 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -40,20 +40,20 @@ struct fwnode_handle *__dev_fwnode(struct device *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,
+bool device_property_present(const struct device *dev, const char *propname);
+int device_property_read_u8_array(const struct device *dev, const char *propname,
 				  u8 *val, size_t nval);
-int device_property_read_u16_array(struct device *dev, const char *propname,
+int device_property_read_u16_array(const struct device *dev, const char *propname,
 				   u16 *val, size_t nval);
-int device_property_read_u32_array(struct device *dev, const char *propname,
+int device_property_read_u32_array(const struct device *dev, const char *propname,
 				   u32 *val, size_t nval);
-int device_property_read_u64_array(struct device *dev, const char *propname,
+int device_property_read_u64_array(const struct device *dev, const char *propname,
 				   u64 *val, size_t nval);
-int device_property_read_string_array(struct device *dev, const char *propname,
+int device_property_read_string_array(const struct device *dev, const char *propname,
 				      const char **val, size_t nval);
-int device_property_read_string(struct device *dev, const char *propname,
+int device_property_read_string(const struct device *dev, const char *propname,
 				const char **val);
-int device_property_match_string(struct device *dev,
+int device_property_match_string(const struct device *dev,
 				 const char *propname, const char *string);
 
 bool fwnode_property_present(const struct fwnode_handle *fwnode,
@@ -143,57 +143,57 @@ int fwnode_irq_get_byname(const struct fwnode_handle *fwnode, const char *name);
 
 unsigned int device_get_child_node_count(const struct device *dev);
 
-static inline bool device_property_read_bool(struct device *dev,
+static inline bool device_property_read_bool(const struct device *dev,
 					     const char *propname)
 {
 	return device_property_present(dev, propname);
 }
 
-static inline int device_property_read_u8(struct device *dev,
+static inline int device_property_read_u8(const struct device *dev,
 					  const char *propname, u8 *val)
 {
 	return device_property_read_u8_array(dev, propname, val, 1);
 }
 
-static inline int device_property_read_u16(struct device *dev,
+static inline int device_property_read_u16(const struct device *dev,
 					   const char *propname, u16 *val)
 {
 	return device_property_read_u16_array(dev, propname, val, 1);
 }
 
-static inline int device_property_read_u32(struct device *dev,
+static inline int device_property_read_u32(const struct device *dev,
 					   const char *propname, u32 *val)
 {
 	return device_property_read_u32_array(dev, propname, val, 1);
 }
 
-static inline int device_property_read_u64(struct device *dev,
+static inline int device_property_read_u64(const struct device *dev,
 					   const char *propname, u64 *val)
 {
 	return device_property_read_u64_array(dev, propname, val, 1);
 }
 
-static inline int device_property_count_u8(struct device *dev, const char *propname)
+static inline int device_property_count_u8(const struct device *dev, const char *propname)
 {
 	return device_property_read_u8_array(dev, propname, NULL, 0);
 }
 
-static inline int device_property_count_u16(struct device *dev, const char *propname)
+static inline int device_property_count_u16(const struct device *dev, const char *propname)
 {
 	return device_property_read_u16_array(dev, propname, NULL, 0);
 }
 
-static inline int device_property_count_u32(struct device *dev, const char *propname)
+static inline int device_property_count_u32(const struct device *dev, const char *propname)
 {
 	return device_property_read_u32_array(dev, propname, NULL, 0);
 }
 
-static inline int device_property_count_u64(struct device *dev, const char *propname)
+static inline int device_property_count_u64(const struct device *dev, const char *propname)
 {
 	return device_property_read_u64_array(dev, propname, NULL, 0);
 }
 
-static inline int device_property_string_array_count(struct device *dev,
+static inline int device_property_string_array_count(const struct device *dev,
 						     const char *propname)
 {
 	return device_property_read_string_array(dev, propname, NULL, 0);
-- 
2.39.2