dm: Add Hardware Spinlock class

This is uclass for Hardware Spinlocks.
It implements two mandatory operations: lock and unlock
and one optional relax operation.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>

4 files changed, 222 insertions, 0 deletions

diff --git a/drivers/hwspinlock/Kconfig b/drivers/hwspinlock/Kconfig
new file mode 100644
index 0000000000..de367fd2a9
--- /dev/null
+++ b/drivers/hwspinlock/Kconfig
@@ -0,0 +1,16 @@
+menu "Hardware Spinlock Support"
+
+config DM_HWSPINLOCK
+	bool "Enable U-Boot hardware spinlock support"
+	help
+	  This option enables U-Boot hardware spinlock support
+
+config HWSPINLOCK_SANDBOX
+	bool "Enable Hardware Spinlock support for Sandbox"
+	depends on SANDBOX && DM_HWSPINLOCK
+	help
+	  Enable hardware spinlock support in Sandbox. This is a dummy device that
+	  can be probed and support all the methods of HWSPINLOCK, but does not
+	  really do anything.
+
+endmenu
diff --git a/drivers/hwspinlock/Makefile b/drivers/hwspinlock/Makefile
new file mode 100644
index 0000000000..2704d6814f
--- /dev/null
+++ b/drivers/hwspinlock/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
+#
+# Copyright (C) 2018, STMicroelectronics - All Rights Reserved
+
+obj-$(CONFIG_DM_HWSPINLOCK) += hwspinlock-uclass.o
+obj-$(CONFIG_HWSPINLOCK_SANDBOX) += sandbox_hwspinlock.o
diff --git a/drivers/hwspinlock/hwspinlock-uclass.c b/drivers/hwspinlock/hwspinlock-uclass.c
new file mode 100644
index 0000000000..195f079707
--- /dev/null
+++ b/drivers/hwspinlock/hwspinlock-uclass.c
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
+/*
+ * Copyright (C) 2018, STMicroelectronics - All Rights Reserved
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <hwspinlock.h>
+#include <dm/device-internal.h>
+
+static inline const struct hwspinlock_ops *
+hwspinlock_dev_ops(struct udevice *dev)
+{
+	return (const struct hwspinlock_ops *)dev->driver->ops;
+}
+
+static int hwspinlock_of_xlate_default(struct hwspinlock *hws,
+				       struct ofnode_phandle_args *args)
+{
+	if (args->args_count > 1) {
+		debug("Invaild args_count: %d\n", args->args_count);
+		return -EINVAL;
+	}
+
+	if (args->args_count)
+		hws->id = args->args[0];
+	else
+		hws->id = 0;
+
+	return 0;
+}
+
+int hwspinlock_get_by_index(struct udevice *dev, int index,
+			    struct hwspinlock *hws)
+{
+	int ret;
+	struct ofnode_phandle_args args;
+	struct udevice *dev_hws;
+	const struct hwspinlock_ops *ops;
+
+	assert(hws);
+	hws->dev = NULL;
+
+	ret = dev_read_phandle_with_args(dev, "hwlocks", "#hwlock-cells", 1,
+					 index, &args);
+	if (ret) {
+		dev_dbg(dev, "%s: dev_read_phandle_with_args: err=%d\n",
+			__func__, ret);
+		return ret;
+	}
+
+	ret = uclass_get_device_by_ofnode(UCLASS_HWSPINLOCK,
+					  args.node, &dev_hws);
+	if (ret) {
+		dev_dbg(dev,
+			"%s: uclass_get_device_by_of_offset failed: err=%d\n",
+			__func__, ret);
+		return ret;
+	}
+
+	hws->dev = dev_hws;
+
+	ops = hwspinlock_dev_ops(dev_hws);
+
+	if (ops->of_xlate)
+		ret = ops->of_xlate(hws, &args);
+	else
+		ret = hwspinlock_of_xlate_default(hws, &args);
+	if (ret)
+		dev_dbg(dev, "of_xlate() failed: %d\n", ret);
+
+	return ret;
+}
+
+int hwspinlock_lock_timeout(struct hwspinlock *hws, unsigned int timeout)
+{
+	const struct hwspinlock_ops *ops;
+	ulong start;
+	int ret;
+
+	assert(hws);
+
+	if (!hws->dev)
+		return -EINVAL;
+
+	ops = hwspinlock_dev_ops(hws->dev);
+	if (!ops->lock)
+		return -ENOSYS;
+
+	start = get_timer(0);
+	do {
+		ret = ops->lock(hws->dev, hws->id);
+		if (!ret)
+			return ret;
+
+		if (ops->relax)
+			ops->relax(hws->dev);
+	} while (get_timer(start) < timeout);
+
+	return -ETIMEDOUT;
+}
+
+int hwspinlock_unlock(struct hwspinlock *hws)
+{
+	const struct hwspinlock_ops *ops;
+
+	assert(hws);
+
+	if (!hws->dev)
+		return -EINVAL;
+
+	ops = hwspinlock_dev_ops(hws->dev);
+	if (!ops->unlock)
+		return -ENOSYS;
+
+	return ops->unlock(hws->dev, hws->id);
+}
+
+static int hwspinlock_post_bind(struct udevice *dev)
+{
+#if defined(CONFIG_NEEDS_MANUAL_RELOC)
+	struct hwspinlock_ops *ops = device_get_ops(dev);
+	static int reloc_done;
+
+	if (!reloc_done) {
+		if (ops->lock)
+			ops->lock += gd->reloc_off;
+		if (ops->unlock)
+			ops->unlock += gd->reloc_off;
+		if (ops->relax)
+			ops->relax += gd->reloc_off;
+
+		reloc_done++;
+	}
+#endif
+	return 0;
+}
+
+UCLASS_DRIVER(hwspinlock) = {
+	.id		= UCLASS_HWSPINLOCK,
+	.name		= "hwspinlock",
+	.post_bind	= hwspinlock_post_bind,
+};
diff --git a/drivers/hwspinlock/sandbox_hwspinlock.c b/drivers/hwspinlock/sandbox_hwspinlock.c
new file mode 100644
index 0000000000..be920f5f99
--- /dev/null
+++ b/drivers/hwspinlock/sandbox_hwspinlock.c
@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
+/*
+ * Copyright (C) 2018, STMicroelectronics - All Rights Reserved
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <hwspinlock.h>
+#include <asm/state.h>
+
+static int sandbox_lock(struct udevice *dev, int index)
+{
+	struct sandbox_state *state = state_get_current();
+
+	if (index != 0)
+		return -1;
+
+	if (state->hwspinlock)
+		return -1;
+
+	state->hwspinlock = true;
+
+	return 0;
+}
+
+static int sandbox_unlock(struct udevice *dev, int index)
+{
+	struct sandbox_state *state = state_get_current();
+
+	if (index != 0)
+		return -1;
+
+	if (!state->hwspinlock)
+		return -1;
+
+	state->hwspinlock = false;
+
+	return 0;
+}
+
+static const struct hwspinlock_ops sandbox_hwspinlock_ops = {
+	.lock = sandbox_lock,
+	.unlock = sandbox_unlock,
+};
+
+static const struct udevice_id sandbox_hwspinlock_ids[] = {
+	{ .compatible = "sandbox,hwspinlock" },
+	{}
+};
+
+U_BOOT_DRIVER(hwspinlock_sandbox) = {
+	.name = "hwspinlock_sandbox",
+	.id = UCLASS_HWSPINLOCK,
+	.of_match = sandbox_hwspinlock_ids,
+	.ops = &sandbox_hwspinlock_ops,
+};