hwspinlock: Remove unused hwspin_lock_get_id()

hwspin_lock_get_id() has been unused since the original 2011
commit bd9a4c7 ("drivers: hwspinlock: add framework")

Remove it and the corresponding docs.

Note that the of_hwspin_lock_get_id() version is still in use,
so leave that alone.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Link: https://lore.kernel.org/r/20241215022023.181435-1-linux@treblig.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

Author: Dr. David Alan Gilbert

Documentation/locking/hwspinlock.rst

@@ -301,17 +301,6 @@ The caller should **never** unlock an hwspinlock which is already unlocked.
 Doing so is considered a bug (there is no protection against this).
 This function will never sleep.
 
-::
-
-  int hwspin_lock_get_id(struct hwspinlock *hwlock);
-
-Retrieve id number of a given hwspinlock. This is needed when an
-hwspinlock is dynamically assigned: before it can be used to achieve
-mutual exclusion with a remote cpu, the id number should be communicated
-to the remote task with which we want to synchronize.
-
-Returns the hwspinlock id number, or -EINVAL if hwlock is null.
-
 Typical usage
 =============
 

drivers/hwspinlock/hwspinlock_core.c

@@ -709,23 +709,6 @@ static int __hwspin_lock_request(struct hwspinlock *hwlock)
 	return ret;
 }
 
-/**
- * hwspin_lock_get_id() - retrieve id number of a given hwspinlock
- * @hwlock: a valid hwspinlock instance
- *
- * Returns: the id number of a given @hwlock, or -EINVAL if @hwlock is invalid.
- */
-int hwspin_lock_get_id(struct hwspinlock *hwlock)
-{
-	if (!hwlock) {
-		pr_err("invalid hwlock\n");
-		return -EINVAL;
-	}
-
-	return hwlock_to_id(hwlock);
-}
-EXPORT_SYMBOL_GPL(hwspin_lock_get_id);
-
 /**
  * hwspin_lock_request_specific() - request for a specific hwspinlock
  * @id: index of the specific hwspinlock that is requested

include/linux/hwspinlock.h

@@ -61,7 +61,6 @@ int hwspin_lock_unregister(struct hwspinlock_device *bank);
 struct hwspinlock *hwspin_lock_request_specific(unsigned int id);
 int hwspin_lock_free(struct hwspinlock *hwlock);
 int of_hwspin_lock_get_id(struct device_node *np, int index);
-int hwspin_lock_get_id(struct hwspinlock *hwlock);
 int __hwspin_lock_timeout(struct hwspinlock *, unsigned int, int,
 							unsigned long *);
 int __hwspin_trylock(struct hwspinlock *, int, unsigned long *);
@@ -131,11 +130,6 @@ static inline int of_hwspin_lock_get_id(struct device_node *np, int index)
 	return 0;
 }
 
-static inline int hwspin_lock_get_id(struct hwspinlock *hwlock)
-{
-	return 0;
-}
-
 static inline
 int of_hwspin_lock_get_id_byname(struct device_node *np, const char *name)
 {