[PATCHv2 1/9] hwspinlock/core: add common dt bindings and OF helpers

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All the platform-specific hwlock driver implementations need the
number of locks and the associated base id for registering the
locks present within a hwspinlock device with the driver core.
These two variables are represented by 'hwlock-num-locks' and
'hwlock-base-id' properties. The documentation and OF helpers to
retrieve these common properties have been added to the driver core.

Signed-off-by: Suman Anna <s-anna@xxxxxx>
---
 .../devicetree/bindings/hwlock/hwlock.txt          | 26 +++++++++
 drivers/hwspinlock/hwspinlock_core.c               | 61 +++++++++++++++++++++-
 include/linux/hwspinlock.h                         | 11 ++--
 3 files changed, 93 insertions(+), 5 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/hwlock/hwlock.txt

diff --git a/Documentation/devicetree/bindings/hwlock/hwlock.txt b/Documentation/devicetree/bindings/hwlock/hwlock.txt
new file mode 100644
index 0000000..789930e
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwlock/hwlock.txt
@@ -0,0 +1,26 @@
+Generic hwlock bindings
+=======================
+
+Generic bindings that are common to all the hwlock platform specific driver
+implementations, the retrieved values are used for registering the device
+specific parameters with the hwspinlock core.
+
+The validity and need of these common properties may vary from one driver
+implementation to another. Look through the individual hwlock driver
+binding documentations for identifying which are mandatory and which are
+optional for that specific driver.
+
+Common properties:
+- hwlock-base-id:	Base Id for the locks for a particular hwlock device.
+			This property is used for representing a set of locks
+			present in a hwlock device with a unique base id in
+			the driver core. This property is mandatory ONLY if a
+			SoC has several hwlock devices.
+
+			See documentation on struct hwspinlock_pdata in
+			linux/hwspinlock.h for more details.
+
+- hwlock-num-locks:	Number of locks present in a hwlock device. This
+			property is needed on hwlock devices, where the number
+			of supported locks within a hwlock device cannot be
+			read from a register.
diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c
index 461a0d7..aec32e7 100644
--- a/drivers/hwspinlock/hwspinlock_core.c
+++ b/drivers/hwspinlock/hwspinlock_core.c
@@ -1,7 +1,7 @@
 /*
  * Hardware spinlock framework
  *
- * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com
+ * Copyright (C) 2010-2013 Texas Instruments Incorporated - http://www.ti.com
  *
  * Contact: Ohad Ben-Cohen <ohad@xxxxxxxxxx>
  *
@@ -27,6 +27,7 @@
 #include <linux/hwspinlock.h>
 #include <linux/pm_runtime.h>
 #include <linux/mutex.h>
+#include <linux/of.h>
 
 #include "hwspinlock_internal.h"
 
@@ -308,6 +309,64 @@ out:
 }
 
 /**
+ * of_hwspin_lock_get_base_id() - OF helper to retrieve base id
+ * @dn: device node pointer
+ *
+ * This is an OF helper function that can be called by the underlying
+ * platform-specific implementations, to retrieve the base id for the
+ * set of locks present within a hwspinlock device instance.
+ *
+ * Returns the base id value on success, -ENODEV on generic failure or
+ * an appropriate error code as returned by the OF layer
+ */
+int of_hwspin_lock_get_base_id(struct device_node *dn)
+{
+	unsigned int val;
+	int ret = -ENODEV;
+
+#ifdef CONFIG_OF
+	if (!dn)
+		return -ENODEV;
+
+	ret = of_property_read_u32(dn, "hwlock-base-id", &val);
+	if (!ret)
+		ret = val;
+#endif
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_hwspin_lock_get_base_id);
+
+/**
+ * of_hwspin_lock_get_num_locks() - OF helper to retrieve number of 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
+ * present within a hwspinlock device instance.
+ *
+ * Returns a positive number of locks on success, -ENODEV on generic
+ * failure or an appropriate error code as returned by the OF layer
+ */
+int of_hwspin_lock_get_num_locks(struct device_node *dn)
+{
+	unsigned int val;
+	int ret = -ENODEV;
+
+#ifdef CONFIG_OF
+	if (!dn)
+		return -ENODEV;
+
+	ret = of_property_read_u32(dn, "hwlock-num-locks", &val);
+	if (!ret)
+		ret = val ? val : -ENODEV;
+#endif
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_hwspin_lock_get_num_locks);
+
+/**
  * hwspin_lock_register() - register a new hw spinlock device
  * @bank: the hwspinlock device, which usually provides numerous hw locks
  * @dev: the backing device
diff --git a/include/linux/hwspinlock.h b/include/linux/hwspinlock.h
index 3343298..1f6a5b8 100644
--- a/include/linux/hwspinlock.h
+++ b/include/linux/hwspinlock.h
@@ -1,7 +1,7 @@
 /*
  * Hardware spinlock public header
  *
- * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com
+ * Copyright (C) 2010-2013 Texas Instruments Incorporated - http://www.ti.com
  *
  * Contact: Ohad Ben-Cohen <ohad@xxxxxxxxxx>
  *
@@ -26,6 +26,7 @@
 #define HWLOCK_IRQ	0x02	/* Disable interrupts, don't save state */
 
 struct device;
+struct device_node;
 struct hwspinlock;
 struct hwspinlock_device;
 struct hwspinlock_ops;
@@ -60,6 +61,8 @@ struct hwspinlock_pdata {
 
 #if defined(CONFIG_HWSPINLOCK) || defined(CONFIG_HWSPINLOCK_MODULE)
 
+int of_hwspin_lock_get_base_id(struct device_node *dn);
+int of_hwspin_lock_get_num_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 hwspin_lock_unregister(struct hwspinlock_device *bank);
@@ -80,9 +83,9 @@ void __hwspin_unlock(struct hwspinlock *, int, unsigned long *);
  * code path get compiled away. This way, if CONFIG_HWSPINLOCK is not
  * required on a given setup, users will still work.
  *
- * The only exception is hwspin_lock_register/hwspin_lock_unregister, with which
- * we _do_ want users to fail (no point in registering hwspinlock instances if
- * the framework is not available).
+ * The only exception is hwspin_lock_register/hwspin_lock_unregister and
+ * associated OF helpers, with which we _do_ want users to fail (no point
+ * in registering hwspinlock instances if the framework is not available).
  *
  * Note: ERR_PTR(-ENODEV) will still be considered a success for NULL-checking
  * users. Others, which care, can still check this with IS_ERR.
-- 
1.8.3.3

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