[PATCH v2 08/16] cdev: stub out cdev_read/write for PBL

[Ahmad Fatoum]

To optimize out calls to undefined functions in PBL at compile-time
instead of link time, let's define stubs for the functions that
are referenced in obj-pbl-y files, but inside function sections
that are ultimately unreferenced.

We don't use IS_PROPER here as cdev support is always available
in barebox proper.

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 include/driver.h | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/include/driver.h b/include/driver.h
index c4067d531cc7..3aef385bc837 100644
--- a/include/driver.h
+++ b/include/driver.h
@@ -14,6 +14,7 @@
 #include <device.h>
 #include <of.h>
 #include <init.h>
+#include <errno.h>
 #include <filetype.h>
 
 #define FORMAT_DRIVER_NAME_ID	"%s%d"
@@ -514,21 +515,40 @@ int devfs_create_link(struct cdev *, const char *name);
 int devfs_remove(struct cdev *);
 int cdev_find_free_index(const char *);
 struct cdev *device_find_partition(struct device *dev, const char *name);
-struct cdev *cdev_by_name(const char *filename);
 struct cdev *lcdev_by_name(const char *filename);
 struct cdev *cdev_readlink(struct cdev *cdev);
 struct cdev *cdev_by_device_node(struct device_node *node);
 struct cdev *cdev_by_partuuid(const char *partuuid);
 struct cdev *cdev_by_diskuuid(const char *partuuid);
-struct cdev *cdev_open_by_name(const char *name, unsigned long flags);
 struct cdev *cdev_create_loop(const char *path, ulong flags, loff_t offset);
 void cdev_remove_loop(struct cdev *cdev);
 int cdev_open(struct cdev *, unsigned long flags);
 int cdev_fdopen(struct cdev *cdev, unsigned long flags);
 int cdev_close(struct cdev *cdev);
 int cdev_flush(struct cdev *cdev);
+#if IN_PROPER
 ssize_t cdev_read(struct cdev *cdev, void *buf, size_t count, loff_t offset, ulong flags);
 ssize_t cdev_write(struct cdev *cdev, const void *buf, size_t count, loff_t offset, ulong flags);
+struct cdev *cdev_by_name(const char *filename);
+struct cdev *cdev_open_by_name(const char *name, unsigned long flags);
+#else
+static inline ssize_t cdev_read(struct cdev *cdev, void *buf, size_t count, loff_t offset, ulong flags)
+{
+	return -ENOSYS;
+}
+static inline ssize_t cdev_write(struct cdev *cdev, const void *buf, size_t count, loff_t offset, ulong flags)
+{
+	return -ENOSYS;
+}
+static inline struct cdev *cdev_by_name(const char *filename)
+{
+	return NULL;
+}
+static inline struct cdev *cdev_open_by_name(const char *name, unsigned long flags)
+{
+	return NULL;
+}
+#endif
 int cdev_ioctl(struct cdev *cdev, unsigned int cmd, void *buf);
 int cdev_erase(struct cdev *cdev, loff_t count, loff_t offset);
 int cdev_lseek(struct cdev*, loff_t);
-- 
2.39.5