The property 'hwlock-reserved-locks' will be used to represent
the number of locks to be reserved for clients that would need
to request/operate on specific locks. A new OF helper function,
of_hwspin_lock_get_num_reserved_locks(), is added to minimize
duplication in different platform implementations.
The function will return a value of 0 if the property is not
defined, so as to support a default behavior of marking all
locks as unused and open for anonymous allocations.
Signed-off-by: Suman Anna <s-anna@xxxxxx>
---
.../devicetree/bindings/hwlock/hwlock.txt | 3 +++
drivers/hwspinlock/hwspinlock_core.c | 25 ++++++++++++++++++++++
include/linux/hwspinlock.h | 1 +
3 files changed, 29 insertions(+)
diff --git a/Documentation/devicetree/bindings/hwlock/hwlock.txt b/Documentation/devicetree/bindings/hwlock/hwlock.txt
index d538a9b..88d16d2 100644
--- a/Documentation/devicetree/bindings/hwlock/hwlock.txt
+++ b/Documentation/devicetree/bindings/hwlock/hwlock.txt
@@ -18,6 +18,9 @@ Common properties:
property is needed on hwlock devices, where the number
of supported locks within a hwlock device cannot be
read from a register.
+- hwlock-reserved-locks: Number of locks to reserve for clients requiring
+ specific locks. This value cannot exceed the value of
+ hwlock-num-locks.
- hwlock-base-id: An unique base Id for the locks for a particular hwlock
device. This property is mandatory ONLY if a SoC has
several hwlock devices.
diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c
index e05cea8..e74b55b 100644
--- a/drivers/hwspinlock/hwspinlock_core.c
+++ b/drivers/hwspinlock/hwspinlock_core.c
@@ -286,6 +286,31 @@ int of_hwspin_lock_get_base_id(struct device_node *dn)
EXPORT_SYMBOL_GPL(of_hwspin_lock_get_base_id);
/**
+ * of_hwspin_lock_get_num_reserved_locks() - retrieve number of reserved locks
+ * @dn: device node pointer
+ *
+ * This is an OF helper function that can be called by the underlying platform
+ * specific implementations, to retrieve the number of locks to reserve from
+ * the hwspinlock device instance's base id. The hwlock-reserved-locks DT
+ * property needs to be defined for requesting any DT-based locks.
+ *
+ * Returns a positive number of locks on success, a default value of 0 if the
+ * property is missing or an appropriate error code as returned by the OF layer
+ */
+int of_hwspin_lock_get_num_reserved_locks(struct device_node *dn)
+{
+ unsigned int val = 0;
+ int ret;
+
+ ret = of_property_read_u32(dn, "hwlock-reserved-locks", &val);
+ if (!ret || ret == -EINVAL)
+ ret = val;
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(of_hwspin_lock_get_num_reserved_locks);
+
+/**
* of_hwspin_lock_get_num_locks() - OF helper to retrieve number of locks
* @dn: device node pointer
*
diff --git a/include/linux/hwspinlock.h b/include/linux/hwspinlock.h
index d120035..d18431f 100644
--- a/include/linux/hwspinlock.h
+++ b/include/linux/hwspinlock.h
@@ -69,6 +69,7 @@ int of_hwspin_lock_simple_xlate(struct hwspinlock_device *bank,
const struct of_phandle_args *hwlock_spec);
int of_hwspin_lock_get_base_id(struct device_node *dn);
int of_hwspin_lock_get_num_locks(struct device_node *dn);
+int of_hwspin_lock_get_num_reserved_locks(struct device_node *dn);
int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev,
const struct hwspinlock_ops *ops, int base_id, int num_locks,
int num_reserved_locks);
--
1.9.2
--
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