Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

10 files changed, 2083 insertions, 0 deletions

diff --git a/drivers/hwspinlock/Kconfig b/drivers/hwspinlock/Kconfig
new file mode 100644
index 000000000..32cd26352
--- /dev/null
+++ b/drivers/hwspinlock/Kconfig
@@ -0,0 +1,68 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Generic HWSPINLOCK framework
+#
+
+menuconfig HWSPINLOCK
+	bool "Hardware Spinlock drivers"
+
+if HWSPINLOCK
+
+config HWSPINLOCK_OMAP
+	tristate "OMAP Hardware Spinlock device"
+	depends on ARCH_OMAP4 || SOC_OMAP5 || SOC_DRA7XX || SOC_AM33XX || SOC_AM43XX || ARCH_K3 || COMPILE_TEST
+	help
+	  Say y here to support the OMAP Hardware Spinlock device (firstly
+	  introduced in OMAP4).
+
+	  If unsure, say N.
+
+config HWSPINLOCK_QCOM
+	tristate "Qualcomm Hardware Spinlock device"
+	depends on ARCH_QCOM || COMPILE_TEST
+	select MFD_SYSCON
+	help
+	  Say y here to support the Qualcomm Hardware Mutex functionality, which
+	  provides a synchronisation mechanism for the various processors on
+	  the SoC.
+
+	  If unsure, say N.
+
+config HWSPINLOCK_SIRF
+	tristate "SIRF Hardware Spinlock device"
+	depends on ARCH_SIRF || COMPILE_TEST
+	help
+	  Say y here to support the SIRF Hardware Spinlock device, which
+	  provides a synchronisation mechanism for the various processors
+	  on the SoC.
+
+	  It's safe to say n here if you're not interested in SIRF hardware
+	  spinlock or just want a bare minimum kernel.
+
+config HWSPINLOCK_SPRD
+	tristate "SPRD Hardware Spinlock device"
+	depends on ARCH_SPRD || COMPILE_TEST
+	help
+	  Say y here to support the SPRD Hardware Spinlock device.
+
+	  If unsure, say N.
+
+config HWSPINLOCK_STM32
+	tristate "STM32 Hardware Spinlock device"
+	depends on MACH_STM32MP157 || COMPILE_TEST
+	help
+	  Say y here to support the STM32 Hardware Spinlock device.
+
+	  If unsure, say N.
+
+config HSEM_U8500
+	tristate "STE Hardware Semaphore functionality"
+	depends on ARCH_U8500 || COMPILE_TEST
+	help
+	  Say y here to support the STE Hardware Semaphore functionality, which
+	  provides a synchronisation mechanism for the various processor on the
+	  SoC.
+
+	  If unsure, say N.
+
+endif # HWSPINLOCK
diff --git a/drivers/hwspinlock/Makefile b/drivers/hwspinlock/Makefile
new file mode 100644
index 000000000..ed053e3f0
--- /dev/null
+++ b/drivers/hwspinlock/Makefile
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Generic Hardware Spinlock framework
+#
+
+obj-$(CONFIG_HWSPINLOCK)		+= hwspinlock_core.o
+obj-$(CONFIG_HWSPINLOCK_OMAP)		+= omap_hwspinlock.o
+obj-$(CONFIG_HWSPINLOCK_QCOM)		+= qcom_hwspinlock.o
+obj-$(CONFIG_HWSPINLOCK_SIRF)		+= sirf_hwspinlock.o
+obj-$(CONFIG_HWSPINLOCK_SPRD)		+= sprd_hwspinlock.o
+obj-$(CONFIG_HWSPINLOCK_STM32)		+= stm32_hwspinlock.o
+obj-$(CONFIG_HSEM_U8500)		+= u8500_hsem.o
diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c
new file mode 100644
index 000000000..fd5f5c5a5
--- /dev/null
+++ b/drivers/hwspinlock/hwspinlock_core.c
@@ -0,0 +1,954 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Hardware spinlock framework
+ *
+ * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com
+ *
+ * Contact: Ohad Ben-Cohen <ohad@wizery.com>
+ */
+
+#define pr_fmt(fmt)    "%s: " fmt, __func__
+
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <linux/err.h>
+#include <linux/jiffies.h>
+#include <linux/radix-tree.h>
+#include <linux/hwspinlock.h>
+#include <linux/pm_runtime.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+
+#include "hwspinlock_internal.h"
+
+/* retry delay used in atomic context */
+#define HWSPINLOCK_RETRY_DELAY_US	100
+
+/* radix tree tags */
+#define HWSPINLOCK_UNUSED	(0) /* tags an hwspinlock as unused */
+
+/*
+ * A radix tree is used to maintain the available hwspinlock instances.
+ * The tree associates hwspinlock pointers with their integer key id,
+ * and provides easy-to-use API which makes the hwspinlock core code simple
+ * and easy to read.
+ *
+ * Radix trees are quick on lookups, and reasonably efficient in terms of
+ * storage, especially with high density usages such as this framework
+ * requires (a continuous range of integer keys, beginning with zero, is
+ * used as the ID's of the hwspinlock instances).
+ *
+ * The radix tree API supports tagging items in the tree, which this
+ * framework uses to mark unused hwspinlock instances (see the
+ * HWSPINLOCK_UNUSED tag above). As a result, the process of querying the
+ * tree, looking for an unused hwspinlock instance, is now reduced to a
+ * single radix tree API call.
+ */
+static RADIX_TREE(hwspinlock_tree, GFP_KERNEL);
+
+/*
+ * Synchronization of access to the tree is achieved using this mutex,
+ * as the radix-tree API requires that users provide all synchronisation.
+ * A mutex is needed because we're using non-atomic radix tree allocations.
+ */
+static DEFINE_MUTEX(hwspinlock_tree_lock);
+
+
+/**
+ * __hwspin_trylock() - attempt to lock a specific hwspinlock
+ * @hwlock: an hwspinlock which we want to trylock
+ * @mode: controls whether local interrupts are disabled or not
+ * @flags: a pointer where the caller's interrupt state will be saved at (if
+ *         requested)
+ *
+ * This function attempts to lock an hwspinlock, and will immediately
+ * fail if the hwspinlock is already taken.
+ *
+ * Caution: If the mode is HWLOCK_RAW, that means user must protect the routine
+ * of getting hardware lock with mutex or spinlock. Since in some scenarios,
+ * user need some time-consuming or sleepable operations under the hardware
+ * lock, they need one sleepable lock (like mutex) to protect the operations.
+ *
+ * If the mode is neither HWLOCK_IN_ATOMIC nor HWLOCK_RAW, upon a successful
+ * return from this function, preemption (and possibly interrupts) is disabled,
+ * so the caller must not sleep, and is advised to release the hwspinlock as
+ * soon as possible. This is required in order to minimize remote cores polling
+ * on the hardware interconnect.
+ *
+ * The user decides whether local interrupts are disabled or not, and if yes,
+ * whether he wants their previous state to be saved. It is up to the user
+ * to choose the appropriate @mode of operation, exactly the same way users
+ * should decide between spin_trylock, spin_trylock_irq and
+ * spin_trylock_irqsave.
+ *
+ * Returns 0 if we successfully locked the hwspinlock or -EBUSY if
+ * the hwspinlock was already taken.
+ * This function will never sleep.
+ */
+int __hwspin_trylock(struct hwspinlock *hwlock, int mode, unsigned long *flags)
+{
+	int ret;
+
+	if (WARN_ON(!hwlock || (!flags && mode == HWLOCK_IRQSTATE)))
+		return -EINVAL;
+
+	/*
+	 * This spin_lock{_irq, _irqsave} serves three purposes:
+	 *
+	 * 1. Disable preemption, in order to minimize the period of time
+	 *    in which the hwspinlock is taken. This is important in order
+	 *    to minimize the possible polling on the hardware interconnect
+	 *    by a remote user of this lock.
+	 * 2. Make the hwspinlock SMP-safe (so we can take it from
+	 *    additional contexts on the local host).
+	 * 3. Ensure that in_atomic/might_sleep checks catch potential
+	 *    problems with hwspinlock usage (e.g. scheduler checks like
+	 *    'scheduling while atomic' etc.)
+	 */
+	switch (mode) {
+	case HWLOCK_IRQSTATE:
+		ret = spin_trylock_irqsave(&hwlock->lock, *flags);
+		break;
+	case HWLOCK_IRQ:
+		ret = spin_trylock_irq(&hwlock->lock);
+		break;
+	case HWLOCK_RAW:
+	case HWLOCK_IN_ATOMIC:
+		ret = 1;
+		break;
+	default:
+		ret = spin_trylock(&hwlock->lock);
+		break;
+	}
+
+	/* is lock already taken by another context on the local cpu ? */
+	if (!ret)
+		return -EBUSY;
+
+	/* try to take the hwspinlock device */
+	ret = hwlock->bank->ops->trylock(hwlock);
+
+	/* if hwlock is already taken, undo spin_trylock_* and exit */
+	if (!ret) {
+		switch (mode) {
+		case HWLOCK_IRQSTATE:
+			spin_unlock_irqrestore(&hwlock->lock, *flags);
+			break;
+		case HWLOCK_IRQ:
+			spin_unlock_irq(&hwlock->lock);
+			break;
+		case HWLOCK_RAW:
+		case HWLOCK_IN_ATOMIC:
+			/* Nothing to do */
+			break;
+		default:
+			spin_unlock(&hwlock->lock);
+			break;
+		}
+
+		return -EBUSY;
+	}
+
+	/*
+	 * We can be sure the other core's memory operations
+	 * are observable to us only _after_ we successfully take
+	 * the hwspinlock, and we must make sure that subsequent memory
+	 * operations (both reads and writes) will not be reordered before
+	 * we actually took the hwspinlock.
+	 *
+	 * Note: the implicit memory barrier of the spinlock above is too
+	 * early, so we need this additional explicit memory barrier.
+	 */
+	mb();
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(__hwspin_trylock);
+
+/**
+ * __hwspin_lock_timeout() - lock an hwspinlock with timeout limit
+ * @hwlock: the hwspinlock to be locked
+ * @timeout: timeout value in msecs
+ * @mode: mode which controls whether local interrupts are disabled or not
+ * @flags: a pointer to where the caller's interrupt state will be saved at (if
+ *         requested)
+ *
+ * This function locks the given @hwlock. If the @hwlock
+ * is already taken, the function will busy loop waiting for it to
+ * be released, but give up after @timeout msecs have elapsed.
+ *
+ * Caution: If the mode is HWLOCK_RAW, that means user must protect the routine
+ * of getting hardware lock with mutex or spinlock. Since in some scenarios,
+ * user need some time-consuming or sleepable operations under the hardware
+ * lock, they need one sleepable lock (like mutex) to protect the operations.
+ *
+ * If the mode is HWLOCK_IN_ATOMIC (called from an atomic context) the timeout
+ * is handled with busy-waiting delays, hence shall not exceed few msecs.
+ *
+ * If the mode is neither HWLOCK_IN_ATOMIC nor HWLOCK_RAW, upon a successful
+ * return from this function, preemption (and possibly interrupts) is disabled,
+ * so the caller must not sleep, and is advised to release the hwspinlock as
+ * soon as possible. This is required in order to minimize remote cores polling
+ * on the hardware interconnect.
+ *
+ * The user decides whether local interrupts are disabled or not, and if yes,
+ * whether he wants their previous state to be saved. It is up to the user
+ * to choose the appropriate @mode of operation, exactly the same way users
+ * should decide between spin_lock, spin_lock_irq and spin_lock_irqsave.
+ *
+ * Returns 0 when the @hwlock was successfully taken, and an appropriate
+ * error code otherwise (most notably -ETIMEDOUT if the @hwlock is still
+ * busy after @timeout msecs). The function will never sleep.
+ */
+int __hwspin_lock_timeout(struct hwspinlock *hwlock, unsigned int to,
+					int mode, unsigned long *flags)
+{
+	int ret;
+	unsigned long expire, atomic_delay = 0;
+
+	expire = msecs_to_jiffies(to) + jiffies;
+
+	for (;;) {
+		/* Try to take the hwspinlock */
+		ret = __hwspin_trylock(hwlock, mode, flags);
+		if (ret != -EBUSY)
+			break;
+
+		/*
+		 * The lock is already taken, let's check if the user wants
+		 * us to try again
+		 */
+		if (mode == HWLOCK_IN_ATOMIC) {
+			udelay(HWSPINLOCK_RETRY_DELAY_US);
+			atomic_delay += HWSPINLOCK_RETRY_DELAY_US;
+			if (atomic_delay > to * 1000)
+				return -ETIMEDOUT;
+		} else {
+			if (time_is_before_eq_jiffies(expire))
+				return -ETIMEDOUT;
+		}
+
+		/*
+		 * Allow platform-specific relax handlers to prevent
+		 * hogging the interconnect (no sleeping, though)
+		 */
+		if (hwlock->bank->ops->relax)
+			hwlock->bank->ops->relax(hwlock);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(__hwspin_lock_timeout);
+
+/**
+ * __hwspin_unlock() - unlock a specific hwspinlock
+ * @hwlock: a previously-acquired hwspinlock which we want to unlock
+ * @mode: controls whether local interrupts needs to be restored or not
+ * @flags: previous caller's interrupt state to restore (if requested)
+ *
+ * This function will unlock a specific hwspinlock, enable preemption and
+ * (possibly) enable interrupts or restore their previous state.
+ * @hwlock must be already locked before calling this function: it is a bug
+ * to call unlock on a @hwlock that is already unlocked.
+ *
+ * The user decides whether local interrupts should be enabled or not, and
+ * if yes, whether he wants their previous state to be restored. It is up
+ * to the user to choose the appropriate @mode of operation, exactly the
+ * same way users decide between spin_unlock, spin_unlock_irq and
+ * spin_unlock_irqrestore.
+ *
+ * The function will never sleep.
+ */
+void __hwspin_unlock(struct hwspinlock *hwlock, int mode, unsigned long *flags)
+{
+	if (WARN_ON(!hwlock || (!flags && mode == HWLOCK_IRQSTATE)))
+		return;
+
+	/*
+	 * We must make sure that memory operations (both reads and writes),
+	 * done before unlocking the hwspinlock, will not be reordered
+	 * after the lock is released.
+	 *
+	 * That's the purpose of this explicit memory barrier.
+	 *
+	 * Note: the memory barrier induced by the spin_unlock below is too
+	 * late; the other core is going to access memory soon after it will
+	 * take the hwspinlock, and by then we want to be sure our memory
+	 * operations are already observable.
+	 */
+	mb();
+
+	hwlock->bank->ops->unlock(hwlock);
+
+	/* Undo the spin_trylock{_irq, _irqsave} called while locking */
+	switch (mode) {
+	case HWLOCK_IRQSTATE:
+		spin_unlock_irqrestore(&hwlock->lock, *flags);
+		break;
+	case HWLOCK_IRQ:
+		spin_unlock_irq(&hwlock->lock);
+		break;
+	case HWLOCK_RAW:
+	case HWLOCK_IN_ATOMIC:
+		/* Nothing to do */
+		break;
+	default:
+		spin_unlock(&hwlock->lock);
+		break;
+	}
+}
+EXPORT_SYMBOL_GPL(__hwspin_unlock);
+
+/**
+ * of_hwspin_lock_simple_xlate - translate hwlock_spec to return a lock id
+ * @bank: the hwspinlock device bank
+ * @hwlock_spec: hwlock specifier as found in the device tree
+ *
+ * This is a simple translation function, suitable for hwspinlock platform
+ * drivers that only has a lock specifier length of 1.
+ *
+ * Returns a relative index of the lock within a specified bank on success,
+ * or -EINVAL on invalid specifier cell count.
+ */
+static inline int
+of_hwspin_lock_simple_xlate(const struct of_phandle_args *hwlock_spec)
+{
+	if (WARN_ON(hwlock_spec->args_count != 1))
+		return -EINVAL;
+
+	return hwlock_spec->args[0];
+}
+
+/**
+ * of_hwspin_lock_get_id() - get lock id for an OF phandle-based specific lock
+ * @np: device node from which to request the specific hwlock
+ * @index: index of the hwlock in the list of values
+ *
+ * This function provides a means for DT users of the hwspinlock module to
+ * get the global lock id of a specific hwspinlock using the phandle of the
+ * hwspinlock device, so that it can be requested using the normal
+ * hwspin_lock_request_specific() API.
+ *
+ * Returns the global lock id number on success, -EPROBE_DEFER if the hwspinlock
+ * device is not yet registered, -EINVAL on invalid args specifier value or an
+ * appropriate error as returned from the OF parsing of the DT client node.
+ */
+int of_hwspin_lock_get_id(struct device_node *np, int index)
+{
+	struct of_phandle_args args;
+	struct hwspinlock *hwlock;
+	struct radix_tree_iter iter;
+	void **slot;
+	int id;
+	int ret;
+
+	ret = of_parse_phandle_with_args(np, "hwlocks", "#hwlock-cells", index,
+					 &args);
+	if (ret)
+		return ret;
+
+	if (!of_device_is_available(args.np)) {
+		ret = -ENOENT;
+		goto out;
+	}
+
+	/* Find the hwspinlock device: we need its base_id */
+	ret = -EPROBE_DEFER;
+	rcu_read_lock();
+	radix_tree_for_each_slot(slot, &hwspinlock_tree, &iter, 0) {
+		hwlock = radix_tree_deref_slot(slot);
+		if (unlikely(!hwlock))
+			continue;
+		if (radix_tree_deref_retry(hwlock)) {
+			slot = radix_tree_iter_retry(&iter);
+			continue;
+		}
+
+		if (hwlock->bank->dev->of_node == args.np) {
+			ret = 0;
+			break;
+		}
+	}
+	rcu_read_unlock();
+	if (ret < 0)
+		goto out;
+
+	id = of_hwspin_lock_simple_xlate(&args);
+	if (id < 0 || id >= hwlock->bank->num_locks) {
+		ret = -EINVAL;
+		goto out;
+	}
+	id += hwlock->bank->base_id;
+
+out:
+	of_node_put(args.np);
+	return ret ? ret : id;
+}
+EXPORT_SYMBOL_GPL(of_hwspin_lock_get_id);
+
+/**
+ * of_hwspin_lock_get_id_byname() - get lock id for an specified hwlock name
+ * @np: device node from which to request the specific hwlock
+ * @name: hwlock name
+ *
+ * This function provides a means for DT users of the hwspinlock module to
+ * get the global lock id of a specific hwspinlock using the specified name of
+ * the hwspinlock device, so that it can be requested using the normal
+ * hwspin_lock_request_specific() API.
+ *
+ * Returns the global lock id number on success, -EPROBE_DEFER if the hwspinlock
+ * device is not yet registered, -EINVAL on invalid args specifier value or an
+ * appropriate error as returned from the OF parsing of the DT client node.
+ */
+int of_hwspin_lock_get_id_byname(struct device_node *np, const char *name)
+{
+	int index;
+
+	if (!name)
+		return -EINVAL;
+
+	index = of_property_match_string(np, "hwlock-names", name);
+	if (index < 0)
+		return index;
+
+	return of_hwspin_lock_get_id(np, index);
+}
+EXPORT_SYMBOL_GPL(of_hwspin_lock_get_id_byname);
+
+static int hwspin_lock_register_single(struct hwspinlock *hwlock, int id)
+{
+	struct hwspinlock *tmp;
+	int ret;
+
+	mutex_lock(&hwspinlock_tree_lock);
+
+	ret = radix_tree_insert(&hwspinlock_tree, id, hwlock);
+	if (ret) {
+		if (ret == -EEXIST)
+			pr_err("hwspinlock id %d already exists!\n", id);
+		goto out;
+	}
+
+	/* mark this hwspinlock as available */
+	tmp = radix_tree_tag_set(&hwspinlock_tree, id, HWSPINLOCK_UNUSED);
+
+	/* self-sanity check which should never fail */
+	WARN_ON(tmp != hwlock);
+
+out:
+	mutex_unlock(&hwspinlock_tree_lock);
+	return 0;
+}
+
+static struct hwspinlock *hwspin_lock_unregister_single(unsigned int id)
+{
+	struct hwspinlock *hwlock = NULL;
+	int ret;
+
+	mutex_lock(&hwspinlock_tree_lock);
+
+	/* make sure the hwspinlock is not in use (tag is set) */
+	ret = radix_tree_tag_get(&hwspinlock_tree, id, HWSPINLOCK_UNUSED);
+	if (ret == 0) {
+		pr_err("hwspinlock %d still in use (or not present)\n", id);
+		goto out;
+	}
+
+	hwlock = radix_tree_delete(&hwspinlock_tree, id);
+	if (!hwlock) {
+		pr_err("failed to delete hwspinlock %d\n", id);
+		goto out;
+	}
+
+out:
+	mutex_unlock(&hwspinlock_tree_lock);
+	return hwlock;
+}
+
+/**
+ * hwspin_lock_register() - register a new hw spinlock device
+ * @bank: the hwspinlock device, which usually provides numerous hw locks
+ * @dev: the backing device
+ * @ops: hwspinlock handlers for this device
+ * @base_id: id of the first hardware spinlock in this bank
+ * @num_locks: number of hwspinlocks provided by this device
+ *
+ * This function should be called from the underlying platform-specific
+ * implementation, to register a new hwspinlock device instance.
+ *
+ * Should be called from a process context (might sleep)
+ *
+ * Returns 0 on success, or an appropriate error code on failure
+ */
+int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev,
+		const struct hwspinlock_ops *ops, int base_id, int num_locks)
+{
+	struct hwspinlock *hwlock;
+	int ret = 0, i;
+
+	if (!bank || !ops || !dev || !num_locks || !ops->trylock ||
+							!ops->unlock) {
+		pr_err("invalid parameters\n");
+		return -EINVAL;
+	}
+
+	bank->dev = dev;
+	bank->ops = ops;
+	bank->base_id = base_id;
+	bank->num_locks = num_locks;
+
+	for (i = 0; i < num_locks; i++) {
+		hwlock = &bank->lock[i];
+
+		spin_lock_init(&hwlock->lock);
+		hwlock->bank = bank;
+
+		ret = hwspin_lock_register_single(hwlock, base_id + i);
+		if (ret)
+			goto reg_failed;
+	}
+
+	return 0;
+
+reg_failed:
+	while (--i >= 0)
+		hwspin_lock_unregister_single(base_id + i);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(hwspin_lock_register);
+
+/**
+ * hwspin_lock_unregister() - unregister an hw spinlock device
+ * @bank: the hwspinlock device, which usually provides numerous hw locks
+ *
+ * This function should be called from the underlying platform-specific
+ * implementation, to unregister an existing (and unused) hwspinlock.
+ *
+ * Should be called from a process context (might sleep)
+ *
+ * Returns 0 on success, or an appropriate error code on failure
+ */
+int hwspin_lock_unregister(struct hwspinlock_device *bank)
+{
+	struct hwspinlock *hwlock, *tmp;
+	int i;
+
+	for (i = 0; i < bank->num_locks; i++) {
+		hwlock = &bank->lock[i];
+
+		tmp = hwspin_lock_unregister_single(bank->base_id + i);
+		if (!tmp)
+			return -EBUSY;
+
+		/* self-sanity check that should never fail */
+		WARN_ON(tmp != hwlock);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(hwspin_lock_unregister);
+
+static void devm_hwspin_lock_unreg(struct device *dev, void *res)
+{
+	hwspin_lock_unregister(*(struct hwspinlock_device **)res);
+}
+
+static int devm_hwspin_lock_device_match(struct device *dev, void *res,
+					 void *data)
+{
+	struct hwspinlock_device **bank = res;
+
+	if (WARN_ON(!bank || !*bank))
+		return 0;
+
+	return *bank == data;
+}
+
+/**
+ * devm_hwspin_lock_unregister() - unregister an hw spinlock device for
+ *				   a managed device
+ * @dev: the backing device
+ * @bank: the hwspinlock device, which usually provides numerous hw locks
+ *
+ * This function should be called from the underlying platform-specific
+ * implementation, to unregister an existing (and unused) hwspinlock.
+ *
+ * Should be called from a process context (might sleep)
+ *
+ * Returns 0 on success, or an appropriate error code on failure
+ */
+int devm_hwspin_lock_unregister(struct device *dev,
+				struct hwspinlock_device *bank)
+{
+	int ret;
+
+	ret = devres_release(dev, devm_hwspin_lock_unreg,
+			     devm_hwspin_lock_device_match, bank);
+	WARN_ON(ret);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devm_hwspin_lock_unregister);
+
+/**
+ * devm_hwspin_lock_register() - register a new hw spinlock device for
+ *				 a managed device
+ * @dev: the backing device
+ * @bank: the hwspinlock device, which usually provides numerous hw locks
+ * @ops: hwspinlock handlers for this device
+ * @base_id: id of the first hardware spinlock in this bank
+ * @num_locks: number of hwspinlocks provided by this device
+ *
+ * This function should be called from the underlying platform-specific
+ * implementation, to register a new hwspinlock device instance.
+ *
+ * Should be called from a process context (might sleep)
+ *
+ * Returns 0 on success, or an appropriate error code on failure
+ */
+int devm_hwspin_lock_register(struct device *dev,
+			      struct hwspinlock_device *bank,
+			      const struct hwspinlock_ops *ops,
+			      int base_id, int num_locks)
+{
+	struct hwspinlock_device **ptr;
+	int ret;
+
+	ptr = devres_alloc(devm_hwspin_lock_unreg, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	ret = hwspin_lock_register(bank, dev, ops, base_id, num_locks);
+	if (!ret) {
+		*ptr = bank;
+		devres_add(dev, ptr);
+	} else {
+		devres_free(ptr);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devm_hwspin_lock_register);
+
+/**
+ * __hwspin_lock_request() - tag an hwspinlock as used and power it up
+ *
+ * This is an internal function that prepares an hwspinlock instance
+ * before it is given to the user. The function assumes that
+ * hwspinlock_tree_lock is taken.
+ *
+ * Returns 0 or positive to indicate success, and a negative value to
+ * indicate an error (with the appropriate error code)
+ */
+static int __hwspin_lock_request(struct hwspinlock *hwlock)
+{
+	struct device *dev = hwlock->bank->dev;
+	struct hwspinlock *tmp;
+	int ret;
+
+	/* prevent underlying implementation from being removed */
+	if (!try_module_get(dev->driver->owner)) {
+		dev_err(dev, "%s: can't get owner\n", __func__);
+		return -EINVAL;
+	}
+
+	/* notify PM core that power is now needed */
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0 && ret != -EACCES) {
+		dev_err(dev, "%s: can't power on device\n", __func__);
+		pm_runtime_put_noidle(dev);
+		module_put(dev->driver->owner);
+		return ret;
+	}
+
+	ret = 0;
+
+	/* mark hwspinlock as used, should not fail */
+	tmp = radix_tree_tag_clear(&hwspinlock_tree, hwlock_to_id(hwlock),
+							HWSPINLOCK_UNUSED);
+
+	/* self-sanity check that should never fail */
+	WARN_ON(tmp != 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() - request an hwspinlock
+ *
+ * This function should be called by users of the hwspinlock device,
+ * in order to dynamically assign them an unused hwspinlock.
+ * Usually the user of this lock will then have to communicate the lock's id
+ * to the remote core before it can be used for synchronization (to get the
+ * id of a given hwlock, use hwspin_lock_get_id()).
+ *
+ * Should be called from a process context (might sleep)
+ *
+ * Returns the address of the assigned hwspinlock, or NULL on error
+ */
+struct hwspinlock *hwspin_lock_request(void)
+{
+	struct hwspinlock *hwlock;
+	int ret;
+
+	mutex_lock(&hwspinlock_tree_lock);
+
+	/* look for an unused lock */
+	ret = radix_tree_gang_lookup_tag(&hwspinlock_tree, (void **)&hwlock,
+						0, 1, HWSPINLOCK_UNUSED);
+	if (ret == 0) {
+		pr_warn("a free hwspinlock is not available\n");
+		hwlock = NULL;
+		goto out;
+	}
+
+	/* sanity check that should never fail */
+	WARN_ON(ret > 1);
+
+	/* mark as used and power up */
+	ret = __hwspin_lock_request(hwlock);
+	if (ret < 0)
+		hwlock = NULL;
+
+out:
+	mutex_unlock(&hwspinlock_tree_lock);
+	return hwlock;
+}
+EXPORT_SYMBOL_GPL(hwspin_lock_request);
+
+/**
+ * hwspin_lock_request_specific() - request for a specific hwspinlock
+ * @id: index of the specific hwspinlock that is requested
+ *
+ * This function should be called by users of the hwspinlock module,
+ * in order to assign them a specific hwspinlock.
+ * Usually early board code will be calling this function in order to
+ * reserve specific hwspinlock ids for predefined purposes.
+ *
+ * Should be called from a process context (might sleep)
+ *
+ * Returns the address of the assigned hwspinlock, or NULL on error
+ */
+struct hwspinlock *hwspin_lock_request_specific(unsigned int id)
+{
+	struct hwspinlock *hwlock;
+	int ret;
+
+	mutex_lock(&hwspinlock_tree_lock);
+
+	/* make sure this hwspinlock exists */
+	hwlock = radix_tree_lookup(&hwspinlock_tree, id);
+	if (!hwlock) {
+		pr_warn("hwspinlock %u does not exist\n", id);
+		goto out;
+	}
+
+	/* sanity check (this shouldn't happen) */
+	WARN_ON(hwlock_to_id(hwlock) != id);
+
+	/* make sure this hwspinlock is unused */
+	ret = radix_tree_tag_get(&hwspinlock_tree, id, HWSPINLOCK_UNUSED);
+	if (ret == 0) {
+		pr_warn("hwspinlock %u is already in use\n", id);
+		hwlock = NULL;
+		goto out;
+	}
+
+	/* mark as used and power up */
+	ret = __hwspin_lock_request(hwlock);
+	if (ret < 0)
+		hwlock = NULL;
+
+out:
+	mutex_unlock(&hwspinlock_tree_lock);
+	return hwlock;
+}
+EXPORT_SYMBOL_GPL(hwspin_lock_request_specific);
+
+/**
+ * hwspin_lock_free() - free a specific hwspinlock
+ * @hwlock: the specific hwspinlock to free
+ *
+ * This function mark @hwlock as free again.
+ * Should only be called with an @hwlock that was retrieved from
+ * an earlier call to hwspin_lock_request{_specific}.
+ *
+ * Should be called from a process context (might sleep)
+ *
+ * Returns 0 on success, or an appropriate error code on failure
+ */
+int hwspin_lock_free(struct hwspinlock *hwlock)
+{
+	struct device *dev;
+	struct hwspinlock *tmp;
+	int ret;
+
+	if (!hwlock) {
+		pr_err("invalid hwlock\n");
+		return -EINVAL;
+	}
+
+	dev = hwlock->bank->dev;
+	mutex_lock(&hwspinlock_tree_lock);
+
+	/* make sure the hwspinlock is used */
+	ret = radix_tree_tag_get(&hwspinlock_tree, hwlock_to_id(hwlock),
+							HWSPINLOCK_UNUSED);
+	if (ret == 1) {
+		dev_err(dev, "%s: hwlock is already free\n", __func__);
+		dump_stack();
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* notify the underlying device that power is not needed */
+	pm_runtime_put(dev);
+
+	/* mark this hwspinlock as available */
+	tmp = radix_tree_tag_set(&hwspinlock_tree, hwlock_to_id(hwlock),
+							HWSPINLOCK_UNUSED);
+
+	/* sanity check (this shouldn't happen) */
+	WARN_ON(tmp != hwlock);
+
+	module_put(dev->driver->owner);
+
+out:
+	mutex_unlock(&hwspinlock_tree_lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(hwspin_lock_free);
+
+static int devm_hwspin_lock_match(struct device *dev, void *res, void *data)
+{
+	struct hwspinlock **hwlock = res;
+
+	if (WARN_ON(!hwlock || !*hwlock))
+		return 0;
+
+	return *hwlock == data;
+}
+
+static void devm_hwspin_lock_release(struct device *dev, void *res)
+{
+	hwspin_lock_free(*(struct hwspinlock **)res);
+}
+
+/**
+ * devm_hwspin_lock_free() - free a specific hwspinlock for a managed device
+ * @dev: the device to free the specific hwspinlock
+ * @hwlock: the specific hwspinlock to free
+ *
+ * This function mark @hwlock as free again.
+ * Should only be called with an @hwlock that was retrieved from
+ * an earlier call to hwspin_lock_request{_specific}.
+ *
+ * Should be called from a process context (might sleep)
+ *
+ * Returns 0 on success, or an appropriate error code on failure
+ */
+int devm_hwspin_lock_free(struct device *dev, struct hwspinlock *hwlock)
+{
+	int ret;
+
+	ret = devres_release(dev, devm_hwspin_lock_release,
+			     devm_hwspin_lock_match, hwlock);
+	WARN_ON(ret);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devm_hwspin_lock_free);
+
+/**
+ * devm_hwspin_lock_request() - request an hwspinlock for a managed device
+ * @dev: the device to request an hwspinlock
+ *
+ * This function should be called by users of the hwspinlock device,
+ * in order to dynamically assign them an unused hwspinlock.
+ * Usually the user of this lock will then have to communicate the lock's id
+ * to the remote core before it can be used for synchronization (to get the
+ * id of a given hwlock, use hwspin_lock_get_id()).
+ *
+ * Should be called from a process context (might sleep)
+ *
+ * Returns the address of the assigned hwspinlock, or NULL on error
+ */
+struct hwspinlock *devm_hwspin_lock_request(struct device *dev)
+{
+	struct hwspinlock **ptr, *hwlock;
+
+	ptr = devres_alloc(devm_hwspin_lock_release, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return NULL;
+
+	hwlock = hwspin_lock_request();
+	if (hwlock) {
+		*ptr = hwlock;
+		devres_add(dev, ptr);
+	} else {
+		devres_free(ptr);
+	}
+
+	return hwlock;
+}
+EXPORT_SYMBOL_GPL(devm_hwspin_lock_request);
+
+/**
+ * devm_hwspin_lock_request_specific() - request for a specific hwspinlock for
+ *					 a managed device
+ * @dev: the device to request the specific hwspinlock
+ * @id: index of the specific hwspinlock that is requested
+ *
+ * This function should be called by users of the hwspinlock module,
+ * in order to assign them a specific hwspinlock.
+ * Usually early board code will be calling this function in order to
+ * reserve specific hwspinlock ids for predefined purposes.
+ *
+ * Should be called from a process context (might sleep)
+ *
+ * Returns the address of the assigned hwspinlock, or NULL on error
+ */
+struct hwspinlock *devm_hwspin_lock_request_specific(struct device *dev,
+						     unsigned int id)
+{
+	struct hwspinlock **ptr, *hwlock;
+
+	ptr = devres_alloc(devm_hwspin_lock_release, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return NULL;
+
+	hwlock = hwspin_lock_request_specific(id);
+	if (hwlock) {
+		*ptr = hwlock;
+		devres_add(dev, ptr);
+	} else {
+		devres_free(ptr);
+	}
+
+	return hwlock;
+}
+EXPORT_SYMBOL_GPL(devm_hwspin_lock_request_specific);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Hardware spinlock interface");
+MODULE_AUTHOR("Ohad Ben-Cohen <ohad@wizery.com>");
diff --git a/drivers/hwspinlock/hwspinlock_internal.h b/drivers/hwspinlock/hwspinlock_internal.h
new file mode 100644
index 000000000..29892767b
--- /dev/null
+++ b/drivers/hwspinlock/hwspinlock_internal.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Hardware spinlocks internal header
+ *
+ * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com
+ *
+ * Contact: Ohad Ben-Cohen <ohad@wizery.com>
+ */
+
+#ifndef __HWSPINLOCK_HWSPINLOCK_H
+#define __HWSPINLOCK_HWSPINLOCK_H
+
+#include <linux/spinlock.h>
+#include <linux/device.h>
+
+struct hwspinlock_device;
+
+/**
+ * struct hwspinlock_ops - platform-specific hwspinlock handlers
+ *
+ * @trylock: make a single attempt to take the lock. returns 0 on
+ *	     failure and true on success. may _not_ sleep.
+ * @unlock:  release the lock. always succeed. may _not_ sleep.
+ * @relax:   optional, platform-specific relax handler, called by hwspinlock
+ *	     core while spinning on a lock, between two successive
+ *	     invocations of @trylock. may _not_ sleep.
+ */
+struct hwspinlock_ops {
+	int (*trylock)(struct hwspinlock *lock);
+	void (*unlock)(struct hwspinlock *lock);
+	void (*relax)(struct hwspinlock *lock);
+};
+
+/**
+ * struct hwspinlock - this struct represents a single hwspinlock instance
+ * @bank: the hwspinlock_device structure which owns this lock
+ * @lock: initialized and used by hwspinlock core
+ * @priv: private data, owned by the underlying platform-specific hwspinlock drv
+ */
+struct hwspinlock {
+	struct hwspinlock_device *bank;
+	spinlock_t lock;
+	void *priv;
+};
+
+/**
+ * struct hwspinlock_device - a device which usually spans numerous hwspinlocks
+ * @dev: underlying device, will be used to invoke runtime PM api
+ * @ops: platform-specific hwspinlock handlers
+ * @base_id: id index of the first lock in this device
+ * @num_locks: number of locks in this device
+ * @lock: dynamically allocated array of 'struct hwspinlock'
+ */
+struct hwspinlock_device {
+	struct device *dev;
+	const struct hwspinlock_ops *ops;
+	int base_id;
+	int num_locks;
+	struct hwspinlock lock[];
+};
+
+static inline int hwlock_to_id(struct hwspinlock *hwlock)
+{
+	int local_id = hwlock - &hwlock->bank->lock[0];
+
+	return hwlock->bank->base_id + local_id;
+}
+
+#endif /* __HWSPINLOCK_HWSPINLOCK_H */
diff --git a/drivers/hwspinlock/omap_hwspinlock.c b/drivers/hwspinlock/omap_hwspinlock.c
new file mode 100644
index 000000000..3b0556045
--- /dev/null
+++ b/drivers/hwspinlock/omap_hwspinlock.c
@@ -0,0 +1,198 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * OMAP hardware spinlock driver
+ *
+ * Copyright (C) 2010-2015 Texas Instruments Incorporated - http://www.ti.com
+ *
+ * Contact: Simon Que <sque@ti.com>
+ *          Hari Kanigeri <h-kanigeri2@ti.com>
+ *          Ohad Ben-Cohen <ohad@wizery.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/bitops.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/hwspinlock.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#include "hwspinlock_internal.h"
+
+/* Spinlock register offsets */
+#define SYSSTATUS_OFFSET		0x0014
+#define LOCK_BASE_OFFSET		0x0800
+
+#define SPINLOCK_NUMLOCKS_BIT_OFFSET	(24)
+
+/* Possible values of SPINLOCK_LOCK_REG */
+#define SPINLOCK_NOTTAKEN		(0)	/* free */
+#define SPINLOCK_TAKEN			(1)	/* locked */
+
+static int omap_hwspinlock_trylock(struct hwspinlock *lock)
+{
+	void __iomem *lock_addr = lock->priv;
+
+	/* attempt to acquire the lock by reading its value */
+	return (SPINLOCK_NOTTAKEN == readl(lock_addr));
+}
+
+static void omap_hwspinlock_unlock(struct hwspinlock *lock)
+{
+	void __iomem *lock_addr = lock->priv;
+
+	/* release the lock by writing 0 to it */
+	writel(SPINLOCK_NOTTAKEN, lock_addr);
+}
+
+/*
+ * relax the OMAP interconnect while spinning on it.
+ *
+ * The specs recommended that the retry delay time will be
+ * just over half of the time that a requester would be
+ * expected to hold the lock.
+ *
+ * The number below is taken from an hardware specs example,
+ * obviously it is somewhat arbitrary.
+ */
+static void omap_hwspinlock_relax(struct hwspinlock *lock)
+{
+	ndelay(50);
+}
+
+static const struct hwspinlock_ops omap_hwspinlock_ops = {
+	.trylock = omap_hwspinlock_trylock,
+	.unlock = omap_hwspinlock_unlock,
+	.relax = omap_hwspinlock_relax,
+};
+
+static int omap_hwspinlock_probe(struct platform_device *pdev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	struct hwspinlock_device *bank;
+	struct hwspinlock *hwlock;
+	void __iomem *io_base;
+	int num_locks, i, ret;
+	/* Only a single hwspinlock block device is supported */
+	int base_id = 0;
+
+	if (!node)
+		return -ENODEV;
+
+	io_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(io_base))
+		return PTR_ERR(io_base);
+
+	/*
+	 * make sure the module is enabled and clocked before reading
+	 * the module SYSSTATUS register
+	 */
+	pm_runtime_enable(&pdev->dev);
+	ret = pm_runtime_get_sync(&pdev->dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(&pdev->dev);
+		goto runtime_err;
+	}
+
+	/* Determine number of locks */
+	i = readl(io_base + SYSSTATUS_OFFSET);
+	i >>= SPINLOCK_NUMLOCKS_BIT_OFFSET;
+
+	/*
+	 * runtime PM will make sure the clock of this module is
+	 * enabled again iff at least one lock is requested
+	 */
+	ret = pm_runtime_put(&pdev->dev);
+	if (ret < 0)
+		goto runtime_err;
+
+	/* one of the four lsb's must be set, and nothing else */
+	if (hweight_long(i & 0xf) != 1 || i > 8) {
+		ret = -EINVAL;
+		goto runtime_err;
+	}
+
+	num_locks = i * 32; /* actual number of locks in this device */
+
+	bank = devm_kzalloc(&pdev->dev, struct_size(bank, lock, num_locks),
+			    GFP_KERNEL);
+	if (!bank) {
+		ret = -ENOMEM;
+		goto runtime_err;
+	}
+
+	platform_set_drvdata(pdev, bank);
+
+	for (i = 0, hwlock = &bank->lock[0]; i < num_locks; i++, hwlock++)
+		hwlock->priv = io_base + LOCK_BASE_OFFSET + sizeof(u32) * i;
+
+	ret = hwspin_lock_register(bank, &pdev->dev, &omap_hwspinlock_ops,
+						base_id, num_locks);
+	if (ret)
+		goto runtime_err;
+
+	dev_dbg(&pdev->dev, "Registered %d locks with HwSpinlock core\n",
+		num_locks);
+
+	return 0;
+
+runtime_err:
+	pm_runtime_disable(&pdev->dev);
+	return ret;
+}
+
+static int omap_hwspinlock_remove(struct platform_device *pdev)
+{
+	struct hwspinlock_device *bank = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = hwspin_lock_unregister(bank);
+	if (ret) {
+		dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret);
+		return ret;
+	}
+
+	pm_runtime_disable(&pdev->dev);
+
+	return 0;
+}
+
+static const struct of_device_id omap_hwspinlock_of_match[] = {
+	{ .compatible = "ti,omap4-hwspinlock", },
+	{ .compatible = "ti,am654-hwspinlock", },
+	{ /* end */ },
+};
+MODULE_DEVICE_TABLE(of, omap_hwspinlock_of_match);
+
+static struct platform_driver omap_hwspinlock_driver = {
+	.probe		= omap_hwspinlock_probe,
+	.remove		= omap_hwspinlock_remove,
+	.driver		= {
+		.name	= "omap_hwspinlock",
+		.of_match_table = of_match_ptr(omap_hwspinlock_of_match),
+	},
+};
+
+static int __init omap_hwspinlock_init(void)
+{
+	return platform_driver_register(&omap_hwspinlock_driver);
+}
+/* board init code might need to reserve hwspinlocks for predefined purposes */
+postcore_initcall(omap_hwspinlock_init);
+
+static void __exit omap_hwspinlock_exit(void)
+{
+	platform_driver_unregister(&omap_hwspinlock_driver);
+}
+module_exit(omap_hwspinlock_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Hardware spinlock driver for OMAP");
+MODULE_AUTHOR("Simon Que <sque@ti.com>");
+MODULE_AUTHOR("Hari Kanigeri <h-kanigeri2@ti.com>");
+MODULE_AUTHOR("Ohad Ben-Cohen <ohad@wizery.com>");
diff --git a/drivers/hwspinlock/qcom_hwspinlock.c b/drivers/hwspinlock/qcom_hwspinlock.c
new file mode 100644
index 000000000..e49914664
--- /dev/null
+++ b/drivers/hwspinlock/qcom_hwspinlock.c
@@ -0,0 +1,188 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2013, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2015, Sony Mobile Communications AB
+ */
+
+#include <linux/hwspinlock.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include "hwspinlock_internal.h"
+
+#define QCOM_MUTEX_APPS_PROC_ID	1
+#define QCOM_MUTEX_NUM_LOCKS	32
+
+static int qcom_hwspinlock_trylock(struct hwspinlock *lock)
+{
+	struct regmap_field *field = lock->priv;
+	u32 lock_owner;
+	int ret;
+
+	ret = regmap_field_write(field, QCOM_MUTEX_APPS_PROC_ID);
+	if (ret)
+		return ret;
+
+	ret = regmap_field_read(field, &lock_owner);
+	if (ret)
+		return ret;
+
+	return lock_owner == QCOM_MUTEX_APPS_PROC_ID;
+}
+
+static void qcom_hwspinlock_unlock(struct hwspinlock *lock)
+{
+	struct regmap_field *field = lock->priv;
+	u32 lock_owner;
+	int ret;
+
+	ret = regmap_field_read(field, &lock_owner);
+	if (ret) {
+		pr_err("%s: unable to query spinlock owner\n", __func__);
+		return;
+	}
+
+	if (lock_owner != QCOM_MUTEX_APPS_PROC_ID) {
+		pr_err("%s: spinlock not owned by us (actual owner is %d)\n",
+				__func__, lock_owner);
+	}
+
+	ret = regmap_field_write(field, 0);
+	if (ret)
+		pr_err("%s: failed to unlock spinlock\n", __func__);
+}
+
+static const struct hwspinlock_ops qcom_hwspinlock_ops = {
+	.trylock	= qcom_hwspinlock_trylock,
+	.unlock		= qcom_hwspinlock_unlock,
+};
+
+static const struct of_device_id qcom_hwspinlock_of_match[] = {
+	{ .compatible = "qcom,sfpb-mutex" },
+	{ .compatible = "qcom,tcsr-mutex" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, qcom_hwspinlock_of_match);
+
+static struct regmap *qcom_hwspinlock_probe_syscon(struct platform_device *pdev,
+						   u32 *base, u32 *stride)
+{
+	struct device_node *syscon;
+	struct regmap *regmap;
+	int ret;
+
+	syscon = of_parse_phandle(pdev->dev.of_node, "syscon", 0);
+	if (!syscon)
+		return ERR_PTR(-ENODEV);
+
+	regmap = syscon_node_to_regmap(syscon);
+	of_node_put(syscon);
+	if (IS_ERR(regmap))
+		return regmap;
+
+	ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 1, base);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "no offset in syscon\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 2, stride);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "no stride syscon\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	return regmap;
+}
+
+static const struct regmap_config tcsr_mutex_config = {
+	.reg_bits		= 32,
+	.reg_stride		= 4,
+	.val_bits		= 32,
+	.max_register		= 0x20000,
+	.fast_io		= true,
+};
+
+static struct regmap *qcom_hwspinlock_probe_mmio(struct platform_device *pdev,
+						 u32 *offset, u32 *stride)
+{
+	struct device *dev = &pdev->dev;
+	void __iomem *base;
+
+	/* All modern platform has offset 0 and stride of 4k */
+	*offset = 0;
+	*stride = 0x1000;
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return ERR_CAST(base);
+
+	return devm_regmap_init_mmio(dev, base, &tcsr_mutex_config);
+}
+
+static int qcom_hwspinlock_probe(struct platform_device *pdev)
+{
+	struct hwspinlock_device *bank;
+	struct reg_field field;
+	struct regmap *regmap;
+	size_t array_size;
+	u32 stride;
+	u32 base;
+	int i;
+
+	regmap = qcom_hwspinlock_probe_syscon(pdev, &base, &stride);
+	if (IS_ERR(regmap) && PTR_ERR(regmap) == -ENODEV)
+		regmap = qcom_hwspinlock_probe_mmio(pdev, &base, &stride);
+
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	array_size = QCOM_MUTEX_NUM_LOCKS * sizeof(struct hwspinlock);
+	bank = devm_kzalloc(&pdev->dev, sizeof(*bank) + array_size, GFP_KERNEL);
+	if (!bank)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, bank);
+
+	for (i = 0; i < QCOM_MUTEX_NUM_LOCKS; i++) {
+		field.reg = base + i * stride;
+		field.lsb = 0;
+		field.msb = 31;
+
+		bank->lock[i].priv = devm_regmap_field_alloc(&pdev->dev,
+							     regmap, field);
+	}
+
+	return devm_hwspin_lock_register(&pdev->dev, bank, &qcom_hwspinlock_ops,
+					 0, QCOM_MUTEX_NUM_LOCKS);
+}
+
+static struct platform_driver qcom_hwspinlock_driver = {
+	.probe		= qcom_hwspinlock_probe,
+	.driver		= {
+		.name	= "qcom_hwspinlock",
+		.of_match_table = qcom_hwspinlock_of_match,
+	},
+};
+
+static int __init qcom_hwspinlock_init(void)
+{
+	return platform_driver_register(&qcom_hwspinlock_driver);
+}
+/* board init code might need to reserve hwspinlocks for predefined purposes */
+postcore_initcall(qcom_hwspinlock_init);
+
+static void __exit qcom_hwspinlock_exit(void)
+{
+	platform_driver_unregister(&qcom_hwspinlock_driver);
+}
+module_exit(qcom_hwspinlock_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Hardware spinlock driver for Qualcomm SoCs");
diff --git a/drivers/hwspinlock/sirf_hwspinlock.c b/drivers/hwspinlock/sirf_hwspinlock.c
new file mode 100644
index 000000000..823d3c4f6
--- /dev/null
+++ b/drivers/hwspinlock/sirf_hwspinlock.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SIRF hardware spinlock driver
+ *
+ * Copyright (c) 2015 Cambridge Silicon Radio Limited, a CSR plc group company.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/hwspinlock.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#include "hwspinlock_internal.h"
+
+struct sirf_hwspinlock {
+	void __iomem *io_base;
+	struct hwspinlock_device bank;
+};
+
+/* Number of Hardware Spinlocks*/
+#define	HW_SPINLOCK_NUMBER	30
+
+/* Hardware spinlock register offsets */
+#define HW_SPINLOCK_BASE	0x404
+#define HW_SPINLOCK_OFFSET(x)	(HW_SPINLOCK_BASE + 0x4 * (x))
+
+static int sirf_hwspinlock_trylock(struct hwspinlock *lock)
+{
+	void __iomem *lock_addr = lock->priv;
+
+	/* attempt to acquire the lock by reading value == 1 from it */
+	return !!readl(lock_addr);
+}
+
+static void sirf_hwspinlock_unlock(struct hwspinlock *lock)
+{
+	void __iomem *lock_addr = lock->priv;
+
+	/* release the lock by writing 0 to it */
+	writel(0, lock_addr);
+}
+
+static const struct hwspinlock_ops sirf_hwspinlock_ops = {
+	.trylock = sirf_hwspinlock_trylock,
+	.unlock = sirf_hwspinlock_unlock,
+};
+
+static int sirf_hwspinlock_probe(struct platform_device *pdev)
+{
+	struct sirf_hwspinlock *hwspin;
+	struct hwspinlock *hwlock;
+	int idx;
+
+	if (!pdev->dev.of_node)
+		return -ENODEV;
+
+	hwspin = devm_kzalloc(&pdev->dev,
+			      struct_size(hwspin, bank.lock,
+					  HW_SPINLOCK_NUMBER),
+			      GFP_KERNEL);
+	if (!hwspin)
+		return -ENOMEM;
+
+	/* retrieve io base */
+	hwspin->io_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(hwspin->io_base))
+		return PTR_ERR(hwspin->io_base);
+
+	for (idx = 0; idx < HW_SPINLOCK_NUMBER; idx++) {
+		hwlock = &hwspin->bank.lock[idx];
+		hwlock->priv = hwspin->io_base + HW_SPINLOCK_OFFSET(idx);
+	}
+
+	platform_set_drvdata(pdev, hwspin);
+
+	return devm_hwspin_lock_register(&pdev->dev, &hwspin->bank,
+					 &sirf_hwspinlock_ops, 0,
+					 HW_SPINLOCK_NUMBER);
+}
+
+static const struct of_device_id sirf_hwpinlock_ids[] = {
+	{ .compatible = "sirf,hwspinlock", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, sirf_hwpinlock_ids);
+
+static struct platform_driver sirf_hwspinlock_driver = {
+	.probe = sirf_hwspinlock_probe,
+	.driver = {
+		.name = "atlas7_hwspinlock",
+		.of_match_table = of_match_ptr(sirf_hwpinlock_ids),
+	},
+};
+
+module_platform_driver(sirf_hwspinlock_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("SIRF Hardware spinlock driver");
+MODULE_AUTHOR("Wei Chen <wei.chen@csr.com>");
diff --git a/drivers/hwspinlock/sprd_hwspinlock.c b/drivers/hwspinlock/sprd_hwspinlock.c
new file mode 100644
index 000000000..36dc8038b
--- /dev/null
+++ b/drivers/hwspinlock/sprd_hwspinlock.c
@@ -0,0 +1,171 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Spreadtrum hardware spinlock driver
+ * Copyright (C) 2017 Spreadtrum  - http://www.spreadtrum.com
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/hwspinlock.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include "hwspinlock_internal.h"
+
+/* hwspinlock registers definition */
+#define HWSPINLOCK_RECCTRL		0x4
+#define HWSPINLOCK_MASTERID(_X_)	(0x80 + 0x4 * (_X_))
+#define HWSPINLOCK_TOKEN(_X_)		(0x800 + 0x4 * (_X_))
+
+/* unlocked value */
+#define HWSPINLOCK_NOTTAKEN		0x55aa10c5
+/* bits definition of RECCTRL reg */
+#define HWSPINLOCK_USER_BITS		0x1
+
+/* hwspinlock number */
+#define SPRD_HWLOCKS_NUM		32
+
+struct sprd_hwspinlock_dev {
+	void __iomem *base;
+	struct clk *clk;
+	struct hwspinlock_device bank;
+};
+
+/* try to lock the hardware spinlock */
+static int sprd_hwspinlock_trylock(struct hwspinlock *lock)
+{
+	struct sprd_hwspinlock_dev *sprd_hwlock =
+		dev_get_drvdata(lock->bank->dev);
+	void __iomem *addr = lock->priv;
+	int user_id, lock_id;
+
+	if (!readl(addr))
+		return 1;
+
+	lock_id = hwlock_to_id(lock);
+	/* get the hardware spinlock master/user id */
+	user_id = readl(sprd_hwlock->base + HWSPINLOCK_MASTERID(lock_id));
+	dev_warn(sprd_hwlock->bank.dev,
+		 "hwspinlock [%d] lock failed and master/user id = %d!\n",
+		 lock_id, user_id);
+	return 0;
+}
+
+/* unlock the hardware spinlock */
+static void sprd_hwspinlock_unlock(struct hwspinlock *lock)
+{
+	void __iomem *lock_addr = lock->priv;
+
+	writel(HWSPINLOCK_NOTTAKEN, lock_addr);
+}
+
+/* The specs recommended below number as the retry delay time */
+static void sprd_hwspinlock_relax(struct hwspinlock *lock)
+{
+	ndelay(10);
+}
+
+static const struct hwspinlock_ops sprd_hwspinlock_ops = {
+	.trylock = sprd_hwspinlock_trylock,
+	.unlock = sprd_hwspinlock_unlock,
+	.relax = sprd_hwspinlock_relax,
+};
+
+static void sprd_hwspinlock_disable(void *data)
+{
+	struct sprd_hwspinlock_dev *sprd_hwlock = data;
+
+	clk_disable_unprepare(sprd_hwlock->clk);
+}
+
+static int sprd_hwspinlock_probe(struct platform_device *pdev)
+{
+	struct sprd_hwspinlock_dev *sprd_hwlock;
+	struct hwspinlock *lock;
+	int i, ret;
+
+	if (!pdev->dev.of_node)
+		return -ENODEV;
+
+	sprd_hwlock = devm_kzalloc(&pdev->dev,
+				   sizeof(struct sprd_hwspinlock_dev) +
+				   SPRD_HWLOCKS_NUM * sizeof(*lock),
+				   GFP_KERNEL);
+	if (!sprd_hwlock)
+		return -ENOMEM;
+
+	sprd_hwlock->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(sprd_hwlock->base))
+		return PTR_ERR(sprd_hwlock->base);
+
+	sprd_hwlock->clk = devm_clk_get(&pdev->dev, "enable");
+	if (IS_ERR(sprd_hwlock->clk)) {
+		dev_err(&pdev->dev, "get hwspinlock clock failed!\n");
+		return PTR_ERR(sprd_hwlock->clk);
+	}
+
+	ret = clk_prepare_enable(sprd_hwlock->clk);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(&pdev->dev, sprd_hwspinlock_disable,
+				       sprd_hwlock);
+	if (ret) {
+		dev_err(&pdev->dev,
+			"Failed to add hwspinlock disable action\n");
+		return ret;
+	}
+
+	/* set the hwspinlock to record user id to identify subsystems */
+	writel(HWSPINLOCK_USER_BITS, sprd_hwlock->base + HWSPINLOCK_RECCTRL);
+
+	for (i = 0; i < SPRD_HWLOCKS_NUM; i++) {
+		lock = &sprd_hwlock->bank.lock[i];
+		lock->priv = sprd_hwlock->base + HWSPINLOCK_TOKEN(i);
+	}
+
+	platform_set_drvdata(pdev, sprd_hwlock);
+
+	return devm_hwspin_lock_register(&pdev->dev, &sprd_hwlock->bank,
+					 &sprd_hwspinlock_ops, 0,
+					 SPRD_HWLOCKS_NUM);
+}
+
+static const struct of_device_id sprd_hwspinlock_of_match[] = {
+	{ .compatible = "sprd,hwspinlock-r3p0", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sprd_hwspinlock_of_match);
+
+static struct platform_driver sprd_hwspinlock_driver = {
+	.probe = sprd_hwspinlock_probe,
+	.driver = {
+		.name = "sprd_hwspinlock",
+		.of_match_table = of_match_ptr(sprd_hwspinlock_of_match),
+	},
+};
+
+static int __init sprd_hwspinlock_init(void)
+{
+	return platform_driver_register(&sprd_hwspinlock_driver);
+}
+postcore_initcall(sprd_hwspinlock_init);
+
+static void __exit sprd_hwspinlock_exit(void)
+{
+	platform_driver_unregister(&sprd_hwspinlock_driver);
+}
+module_exit(sprd_hwspinlock_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Hardware spinlock driver for Spreadtrum");
+MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>");
+MODULE_AUTHOR("Lanqing Liu <lanqing.liu@spreadtrum.com>");
+MODULE_AUTHOR("Long Cheng <aiden.cheng@spreadtrum.com>");
diff --git a/drivers/hwspinlock/stm32_hwspinlock.c b/drivers/hwspinlock/stm32_hwspinlock.c
new file mode 100644
index 000000000..3ad0ce0da
--- /dev/null
+++ b/drivers/hwspinlock/stm32_hwspinlock.c
@@ -0,0 +1,161 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) STMicroelectronics SA 2018
+ * Author: Benjamin Gaignard <benjamin.gaignard@st.com> for STMicroelectronics.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/hwspinlock.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+#include "hwspinlock_internal.h"
+
+#define STM32_MUTEX_COREID	BIT(8)
+#define STM32_MUTEX_LOCK_BIT	BIT(31)
+#define STM32_MUTEX_NUM_LOCKS	32
+
+struct stm32_hwspinlock {
+	struct clk *clk;
+	struct hwspinlock_device bank;
+};
+
+static int stm32_hwspinlock_trylock(struct hwspinlock *lock)
+{
+	void __iomem *lock_addr = lock->priv;
+	u32 status;
+
+	writel(STM32_MUTEX_LOCK_BIT | STM32_MUTEX_COREID, lock_addr);
+	status = readl(lock_addr);
+
+	return status == (STM32_MUTEX_LOCK_BIT | STM32_MUTEX_COREID);
+}
+
+static void stm32_hwspinlock_unlock(struct hwspinlock *lock)
+{
+	void __iomem *lock_addr = lock->priv;
+
+	writel(STM32_MUTEX_COREID, lock_addr);
+}
+
+static void stm32_hwspinlock_relax(struct hwspinlock *lock)
+{
+	ndelay(50);
+}
+
+static const struct hwspinlock_ops stm32_hwspinlock_ops = {
+	.trylock	= stm32_hwspinlock_trylock,
+	.unlock		= stm32_hwspinlock_unlock,
+	.relax		= stm32_hwspinlock_relax,
+};
+
+static int stm32_hwspinlock_probe(struct platform_device *pdev)
+{
+	struct stm32_hwspinlock *hw;
+	void __iomem *io_base;
+	size_t array_size;
+	int i, ret;
+
+	io_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(io_base))
+		return PTR_ERR(io_base);
+
+	array_size = STM32_MUTEX_NUM_LOCKS * sizeof(struct hwspinlock);
+	hw = devm_kzalloc(&pdev->dev, sizeof(*hw) + array_size, GFP_KERNEL);
+	if (!hw)
+		return -ENOMEM;
+
+	hw->clk = devm_clk_get(&pdev->dev, "hsem");
+	if (IS_ERR(hw->clk))
+		return PTR_ERR(hw->clk);
+
+	for (i = 0; i < STM32_MUTEX_NUM_LOCKS; i++)
+		hw->bank.lock[i].priv = io_base + i * sizeof(u32);
+
+	platform_set_drvdata(pdev, hw);
+	pm_runtime_enable(&pdev->dev);
+
+	ret = hwspin_lock_register(&hw->bank, &pdev->dev, &stm32_hwspinlock_ops,
+				   0, STM32_MUTEX_NUM_LOCKS);
+
+	if (ret)
+		pm_runtime_disable(&pdev->dev);
+
+	return ret;
+}
+
+static int stm32_hwspinlock_remove(struct platform_device *pdev)
+{
+	struct stm32_hwspinlock *hw = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = hwspin_lock_unregister(&hw->bank);
+	if (ret)
+		dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret);
+
+	pm_runtime_disable(&pdev->dev);
+
+	return 0;
+}
+
+static int __maybe_unused stm32_hwspinlock_runtime_suspend(struct device *dev)
+{
+	struct stm32_hwspinlock *hw = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(hw->clk);
+
+	return 0;
+}
+
+static int __maybe_unused stm32_hwspinlock_runtime_resume(struct device *dev)
+{
+	struct stm32_hwspinlock *hw = dev_get_drvdata(dev);
+
+	clk_prepare_enable(hw->clk);
+
+	return 0;
+}
+
+static const struct dev_pm_ops stm32_hwspinlock_pm_ops = {
+	SET_RUNTIME_PM_OPS(stm32_hwspinlock_runtime_suspend,
+			   stm32_hwspinlock_runtime_resume,
+			   NULL)
+};
+
+static const struct of_device_id stm32_hwpinlock_ids[] = {
+	{ .compatible = "st,stm32-hwspinlock", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, stm32_hwpinlock_ids);
+
+static struct platform_driver stm32_hwspinlock_driver = {
+	.probe		= stm32_hwspinlock_probe,
+	.remove		= stm32_hwspinlock_remove,
+	.driver		= {
+		.name	= "stm32_hwspinlock",
+		.of_match_table = stm32_hwpinlock_ids,
+		.pm	= &stm32_hwspinlock_pm_ops,
+	},
+};
+
+static int __init stm32_hwspinlock_init(void)
+{
+	return platform_driver_register(&stm32_hwspinlock_driver);
+}
+/* board init code might need to reserve hwspinlocks for predefined purposes */
+postcore_initcall(stm32_hwspinlock_init);
+
+static void __exit stm32_hwspinlock_exit(void)
+{
+	platform_driver_unregister(&stm32_hwspinlock_driver);
+}
+module_exit(stm32_hwspinlock_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Hardware spinlock driver for STM32 SoCs");
+MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
diff --git a/drivers/hwspinlock/u8500_hsem.c b/drivers/hwspinlock/u8500_hsem.c
new file mode 100644
index 000000000..67845c0c9
--- /dev/null
+++ b/drivers/hwspinlock/u8500_hsem.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * u8500 HWSEM driver
+ *
+ * Copyright (C) 2010-2011 ST-Ericsson
+ *
+ * Implements u8500 semaphore handling for protocol 1, no interrupts.
+ *
+ * Author: Mathieu Poirier <mathieu.poirier@linaro.org>
+ * Heavily borrowed from the work of :
+ *   Simon Que <sque@ti.com>
+ *   Hari Kanigeri <h-kanigeri2@ti.com>
+ *   Ohad Ben-Cohen <ohad@wizery.com>
+ */
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/hwspinlock.h>
+#include <linux/platform_device.h>
+
+#include "hwspinlock_internal.h"
+
+/*
+ * Implementation of STE's HSem protocol 1 without interrutps.
+ * The only masterID we allow is '0x01' to force people to use
+ * HSems for synchronisation between processors rather than processes
+ * on the ARM core.
+ */
+
+#define U8500_MAX_SEMAPHORE		32	/* a total of 32 semaphore */
+#define RESET_SEMAPHORE			(0)	/* free */
+
+/*
+ * CPU ID for master running u8500 kernel.
+ * Hswpinlocks should only be used to synchonise operations
+ * between the Cortex A9 core and the other CPUs.  Hence
+ * forcing the masterID to a preset value.
+ */
+#define HSEM_MASTER_ID			0x01
+
+#define HSEM_REGISTER_OFFSET		0x08
+
+#define HSEM_CTRL_REG			0x00
+#define HSEM_ICRALL			0x90
+#define HSEM_PROTOCOL_1			0x01
+
+static int u8500_hsem_trylock(struct hwspinlock *lock)
+{
+	void __iomem *lock_addr = lock->priv;
+
+	writel(HSEM_MASTER_ID, lock_addr);
+
+	/* get only first 4 bit and compare to masterID.
+	 * if equal, we have the semaphore, otherwise
+	 * someone else has it.
+	 */
+	return (HSEM_MASTER_ID == (0x0F & readl(lock_addr)));
+}
+
+static void u8500_hsem_unlock(struct hwspinlock *lock)
+{
+	void __iomem *lock_addr = lock->priv;
+
+	/* release the lock by writing 0 to it */
+	writel(RESET_SEMAPHORE, lock_addr);
+}
+
+/*
+ * u8500: what value is recommended here ?
+ */
+static void u8500_hsem_relax(struct hwspinlock *lock)
+{
+	ndelay(50);
+}
+
+static const struct hwspinlock_ops u8500_hwspinlock_ops = {
+	.trylock	= u8500_hsem_trylock,
+	.unlock		= u8500_hsem_unlock,
+	.relax		= u8500_hsem_relax,
+};
+
+static int u8500_hsem_probe(struct platform_device *pdev)
+{
+	struct hwspinlock_pdata *pdata = pdev->dev.platform_data;
+	struct hwspinlock_device *bank;
+	struct hwspinlock *hwlock;
+	void __iomem *io_base;
+	int i, num_locks = U8500_MAX_SEMAPHORE;
+	ulong val;
+
+	if (!pdata)
+		return -ENODEV;
+
+	io_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(io_base))
+		return PTR_ERR(io_base);
+
+	/* make sure protocol 1 is selected */
+	val = readl(io_base + HSEM_CTRL_REG);
+	writel((val & ~HSEM_PROTOCOL_1), io_base + HSEM_CTRL_REG);
+
+	/* clear all interrupts */
+	writel(0xFFFF, io_base + HSEM_ICRALL);
+
+	bank = devm_kzalloc(&pdev->dev, struct_size(bank, lock, num_locks),
+			    GFP_KERNEL);
+	if (!bank)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, bank);
+
+	for (i = 0, hwlock = &bank->lock[0]; i < num_locks; i++, hwlock++)
+		hwlock->priv = io_base + HSEM_REGISTER_OFFSET + sizeof(u32) * i;
+
+	return devm_hwspin_lock_register(&pdev->dev, bank,
+					 &u8500_hwspinlock_ops,
+					 pdata->base_id, num_locks);
+}
+
+static int u8500_hsem_remove(struct platform_device *pdev)
+{
+	struct hwspinlock_device *bank = platform_get_drvdata(pdev);
+	void __iomem *io_base = bank->lock[0].priv - HSEM_REGISTER_OFFSET;
+
+	/* clear all interrupts */
+	writel(0xFFFF, io_base + HSEM_ICRALL);
+
+	return 0;
+}
+
+static struct platform_driver u8500_hsem_driver = {
+	.probe		= u8500_hsem_probe,
+	.remove		= u8500_hsem_remove,
+	.driver		= {
+		.name	= "u8500_hsem",
+	},
+};
+
+static int __init u8500_hsem_init(void)
+{
+	return platform_driver_register(&u8500_hsem_driver);
+}
+/* board init code might need to reserve hwspinlocks for predefined purposes */
+postcore_initcall(u8500_hsem_init);
+
+static void __exit u8500_hsem_exit(void)
+{
+	platform_driver_unregister(&u8500_hsem_driver);
+}
+module_exit(u8500_hsem_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Hardware Spinlock driver for u8500");
+MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");