base: genlock: Add new functions to get the fd
Add new API to get the file descriptor reference to a lock suitable for
sharing with other processes.
Change-Id: I1b61f44b6d5745a628eb98dfdc876767c46552ea
Signed-off-by: Alex Wong <waiw@codeaurora.org>
diff --git a/drivers/base/genlock.c b/drivers/base/genlock.c
index 8b7259a..0de37c9 100644
--- a/drivers/base/genlock.c
+++ b/drivers/base/genlock.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2011-2013, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
@@ -712,6 +712,40 @@
}
EXPORT_SYMBOL(genlock_get_handle_fd);
+/*
+ * Get a file descriptor reference to a lock suitable for sharing with
+ * other processes
+ */
+
+int genlock_get_fd_handle(struct genlock_handle *handle)
+{
+ int ret;
+ struct genlock *lock;
+
+ if (IS_ERR_OR_NULL(handle))
+ return -EINVAL;
+
+ lock = handle->lock;
+
+ if (IS_ERR(lock))
+ return PTR_ERR(lock);
+
+ if (!lock->file) {
+ GENLOCK_LOG_ERR("No file attached to the lock\n");
+ return -EINVAL;
+ }
+
+ ret = get_unused_fd_flags(0);
+
+ if (ret < 0)
+ return ret;
+
+ fd_install(ret, lock->file);
+
+ return ret;
+}
+EXPORT_SYMBOL(genlock_get_fd_handle);
+
#ifdef CONFIG_GENLOCK_MISCDEVICE
static long genlock_dev_ioctl(struct file *filep, unsigned int cmd,
diff --git a/include/linux/genlock.h b/include/linux/genlock.h
index 587c49d..e233662 100644
--- a/include/linux/genlock.h
+++ b/include/linux/genlock.h
@@ -8,6 +8,7 @@
struct genlock_handle *genlock_get_handle(void);
struct genlock_handle *genlock_get_handle_fd(int fd);
+int genlock_get_fd_handle(struct genlock_handle *handle);
void genlock_put_handle(struct genlock_handle *handle);
struct genlock *genlock_create_lock(struct genlock_handle *);
struct genlock *genlock_attach_lock(struct genlock_handle *, int fd);