Adding upstream version 6.1.76.upstream/6.1.76upstream

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

4 files changed, 1009 insertions, 0 deletions

diff --git a/drivers/amba/Kconfig b/drivers/amba/Kconfig
new file mode 100644
index 000000000..fb6c7e0b4
--- /dev/null
+++ b/drivers/amba/Kconfig
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0
+config ARM_AMBA
+	bool
+
+if ARM_AMBA
+
+config TEGRA_AHB
+	bool
+	default y if ARCH_TEGRA
+	help
+	  Adds AHB configuration functionality for NVIDIA Tegra SoCs,
+	  which controls AHB bus master arbitration and some performance
+	  parameters (priority, prefetch size).
+
+endif
diff --git a/drivers/amba/Makefile b/drivers/amba/Makefile
new file mode 100644
index 000000000..cc6b1c925
--- /dev/null
+++ b/drivers/amba/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_ARM_AMBA)		+= bus.o
+obj-$(CONFIG_TEGRA_AHB)		+= tegra-ahb.o
diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
new file mode 100644
index 000000000..0aa2d3111
--- /dev/null
+++ b/drivers/amba/bus.c
@@ -0,0 +1,702 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/arch/arm/common/amba.c
+ *
+ *  Copyright (C) 2003 Deep Blue Solutions Ltd, All Rights Reserved.
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/pm_domain.h>
+#include <linux/amba/bus.h>
+#include <linux/sizes.h>
+#include <linux/limits.h>
+#include <linux/clk/clk-conf.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/of_irq.h>
+#include <linux/of_device.h>
+#include <linux/acpi.h>
+#include <linux/iommu.h>
+#include <linux/dma-map-ops.h>
+
+#define to_amba_driver(d)	container_of(d, struct amba_driver, drv)
+
+/* called on periphid match and class 0x9 coresight device. */
+static int
+amba_cs_uci_id_match(const struct amba_id *table, struct amba_device *dev)
+{
+	int ret = 0;
+	struct amba_cs_uci_id *uci;
+
+	uci = table->data;
+
+	/* no table data or zero mask - return match on periphid */
+	if (!uci || (uci->devarch_mask == 0))
+		return 1;
+
+	/* test against read devtype and masked devarch value */
+	ret = (dev->uci.devtype == uci->devtype) &&
+		((dev->uci.devarch & uci->devarch_mask) == uci->devarch);
+	return ret;
+}
+
+static const struct amba_id *
+amba_lookup(const struct amba_id *table, struct amba_device *dev)
+{
+	while (table->mask) {
+		if (((dev->periphid & table->mask) == table->id) &&
+			((dev->cid != CORESIGHT_CID) ||
+			 (amba_cs_uci_id_match(table, dev))))
+			return table;
+		table++;
+	}
+	return NULL;
+}
+
+static int amba_get_enable_pclk(struct amba_device *pcdev)
+{
+	int ret;
+
+	pcdev->pclk = clk_get(&pcdev->dev, "apb_pclk");
+	if (IS_ERR(pcdev->pclk))
+		return PTR_ERR(pcdev->pclk);
+
+	ret = clk_prepare_enable(pcdev->pclk);
+	if (ret)
+		clk_put(pcdev->pclk);
+
+	return ret;
+}
+
+static void amba_put_disable_pclk(struct amba_device *pcdev)
+{
+	clk_disable_unprepare(pcdev->pclk);
+	clk_put(pcdev->pclk);
+}
+
+
+static ssize_t driver_override_show(struct device *_dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct amba_device *dev = to_amba_device(_dev);
+	ssize_t len;
+
+	device_lock(_dev);
+	len = sprintf(buf, "%s\n", dev->driver_override);
+	device_unlock(_dev);
+	return len;
+}
+
+static ssize_t driver_override_store(struct device *_dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t count)
+{
+	struct amba_device *dev = to_amba_device(_dev);
+	int ret;
+
+	ret = driver_set_override(_dev, &dev->driver_override, buf, count);
+	if (ret)
+		return ret;
+
+	return count;
+}
+static DEVICE_ATTR_RW(driver_override);
+
+#define amba_attr_func(name,fmt,arg...)					\
+static ssize_t name##_show(struct device *_dev,				\
+			   struct device_attribute *attr, char *buf)	\
+{									\
+	struct amba_device *dev = to_amba_device(_dev);			\
+	return sprintf(buf, fmt, arg);					\
+}									\
+static DEVICE_ATTR_RO(name)
+
+amba_attr_func(id, "%08x\n", dev->periphid);
+amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n",
+	 (unsigned long long)dev->res.start, (unsigned long long)dev->res.end,
+	 dev->res.flags);
+
+static struct attribute *amba_dev_attrs[] = {
+	&dev_attr_id.attr,
+	&dev_attr_resource.attr,
+	&dev_attr_driver_override.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(amba_dev);
+
+static int amba_read_periphid(struct amba_device *dev)
+{
+	struct reset_control *rstc;
+	u32 size, pid, cid;
+	void __iomem *tmp;
+	int i, ret;
+
+	ret = dev_pm_domain_attach(&dev->dev, true);
+	if (ret) {
+		dev_dbg(&dev->dev, "can't get PM domain: %d\n", ret);
+		goto err_out;
+	}
+
+	ret = amba_get_enable_pclk(dev);
+	if (ret) {
+		dev_dbg(&dev->dev, "can't get pclk: %d\n", ret);
+		goto err_pm;
+	}
+
+	/*
+	 * Find reset control(s) of the amba bus and de-assert them.
+	 */
+	rstc = of_reset_control_array_get_optional_shared(dev->dev.of_node);
+	if (IS_ERR(rstc)) {
+		ret = PTR_ERR(rstc);
+		if (ret != -EPROBE_DEFER)
+			dev_err(&dev->dev, "can't get reset: %d\n", ret);
+		goto err_clk;
+	}
+	reset_control_deassert(rstc);
+	reset_control_put(rstc);
+
+	size = resource_size(&dev->res);
+	tmp = ioremap(dev->res.start, size);
+	if (!tmp) {
+		ret = -ENOMEM;
+		goto err_clk;
+	}
+
+	/*
+	 * Read pid and cid based on size of resource
+	 * they are located at end of region
+	 */
+	for (pid = 0, i = 0; i < 4; i++)
+		pid |= (readl(tmp + size - 0x20 + 4 * i) & 255) << (i * 8);
+	for (cid = 0, i = 0; i < 4; i++)
+		cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) << (i * 8);
+
+	if (cid == CORESIGHT_CID) {
+		/* set the base to the start of the last 4k block */
+		void __iomem *csbase = tmp + size - 4096;
+
+		dev->uci.devarch = readl(csbase + UCI_REG_DEVARCH_OFFSET);
+		dev->uci.devtype = readl(csbase + UCI_REG_DEVTYPE_OFFSET) & 0xff;
+	}
+
+	if (cid == AMBA_CID || cid == CORESIGHT_CID) {
+		dev->periphid = pid;
+		dev->cid = cid;
+	}
+
+	if (!dev->periphid)
+		ret = -ENODEV;
+
+	iounmap(tmp);
+
+err_clk:
+	amba_put_disable_pclk(dev);
+err_pm:
+	dev_pm_domain_detach(&dev->dev, true);
+err_out:
+	return ret;
+}
+
+static int amba_match(struct device *dev, struct device_driver *drv)
+{
+	struct amba_device *pcdev = to_amba_device(dev);
+	struct amba_driver *pcdrv = to_amba_driver(drv);
+
+	mutex_lock(&pcdev->periphid_lock);
+	if (!pcdev->periphid) {
+		int ret = amba_read_periphid(pcdev);
+
+		/*
+		 * Returning any error other than -EPROBE_DEFER from bus match
+		 * can cause driver registration failure. So, if there's a
+		 * permanent failure in reading pid and cid, simply map it to
+		 * -EPROBE_DEFER.
+		 */
+		if (ret) {
+			mutex_unlock(&pcdev->periphid_lock);
+			return -EPROBE_DEFER;
+		}
+		dev_set_uevent_suppress(dev, false);
+		kobject_uevent(&dev->kobj, KOBJ_ADD);
+	}
+	mutex_unlock(&pcdev->periphid_lock);
+
+	/* When driver_override is set, only bind to the matching driver */
+	if (pcdev->driver_override)
+		return !strcmp(pcdev->driver_override, drv->name);
+
+	return amba_lookup(pcdrv->id_table, pcdev) != NULL;
+}
+
+static int amba_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	struct amba_device *pcdev = to_amba_device(dev);
+	int retval = 0;
+
+	retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid);
+	if (retval)
+		return retval;
+
+	retval = add_uevent_var(env, "MODALIAS=amba:d%08X", pcdev->periphid);
+	return retval;
+}
+
+static int of_amba_device_decode_irq(struct amba_device *dev)
+{
+	struct device_node *node = dev->dev.of_node;
+	int i, irq = 0;
+
+	if (IS_ENABLED(CONFIG_OF_IRQ) && node) {
+		/* Decode the IRQs and address ranges */
+		for (i = 0; i < AMBA_NR_IRQS; i++) {
+			irq = of_irq_get(node, i);
+			if (irq < 0) {
+				if (irq == -EPROBE_DEFER)
+					return irq;
+				irq = 0;
+			}
+
+			dev->irq[i] = irq;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * These are the device model conversion veneers; they convert the
+ * device model structures to our more specific structures.
+ */
+static int amba_probe(struct device *dev)
+{
+	struct amba_device *pcdev = to_amba_device(dev);
+	struct amba_driver *pcdrv = to_amba_driver(dev->driver);
+	const struct amba_id *id = amba_lookup(pcdrv->id_table, pcdev);
+	int ret;
+
+	do {
+		ret = of_amba_device_decode_irq(pcdev);
+		if (ret)
+			break;
+
+		ret = of_clk_set_defaults(dev->of_node, false);
+		if (ret < 0)
+			break;
+
+		ret = dev_pm_domain_attach(dev, true);
+		if (ret)
+			break;
+
+		ret = amba_get_enable_pclk(pcdev);
+		if (ret) {
+			dev_pm_domain_detach(dev, true);
+			break;
+		}
+
+		pm_runtime_get_noresume(dev);
+		pm_runtime_set_active(dev);
+		pm_runtime_enable(dev);
+
+		ret = pcdrv->probe(pcdev, id);
+		if (ret == 0)
+			break;
+
+		pm_runtime_disable(dev);
+		pm_runtime_set_suspended(dev);
+		pm_runtime_put_noidle(dev);
+
+		amba_put_disable_pclk(pcdev);
+		dev_pm_domain_detach(dev, true);
+	} while (0);
+
+	return ret;
+}
+
+static void amba_remove(struct device *dev)
+{
+	struct amba_device *pcdev = to_amba_device(dev);
+	struct amba_driver *drv = to_amba_driver(dev->driver);
+
+	pm_runtime_get_sync(dev);
+	if (drv->remove)
+		drv->remove(pcdev);
+	pm_runtime_put_noidle(dev);
+
+	/* Undo the runtime PM settings in amba_probe() */
+	pm_runtime_disable(dev);
+	pm_runtime_set_suspended(dev);
+	pm_runtime_put_noidle(dev);
+
+	amba_put_disable_pclk(pcdev);
+	dev_pm_domain_detach(dev, true);
+}
+
+static void amba_shutdown(struct device *dev)
+{
+	struct amba_driver *drv;
+
+	if (!dev->driver)
+		return;
+
+	drv = to_amba_driver(dev->driver);
+	if (drv->shutdown)
+		drv->shutdown(to_amba_device(dev));
+}
+
+static int amba_dma_configure(struct device *dev)
+{
+	struct amba_driver *drv = to_amba_driver(dev->driver);
+	enum dev_dma_attr attr;
+	int ret = 0;
+
+	if (dev->of_node) {
+		ret = of_dma_configure(dev, dev->of_node, true);
+	} else if (has_acpi_companion(dev)) {
+		attr = acpi_get_dma_attr(to_acpi_device_node(dev->fwnode));
+		ret = acpi_dma_configure(dev, attr);
+	}
+
+	if (!ret && !drv->driver_managed_dma) {
+		ret = iommu_device_use_default_domain(dev);
+		if (ret)
+			arch_teardown_dma_ops(dev);
+	}
+
+	return ret;
+}
+
+static void amba_dma_cleanup(struct device *dev)
+{
+	struct amba_driver *drv = to_amba_driver(dev->driver);
+
+	if (!drv->driver_managed_dma)
+		iommu_device_unuse_default_domain(dev);
+}
+
+#ifdef CONFIG_PM
+/*
+ * Hooks to provide runtime PM of the pclk (bus clock).  It is safe to
+ * enable/disable the bus clock at runtime PM suspend/resume as this
+ * does not result in loss of context.
+ */
+static int amba_pm_runtime_suspend(struct device *dev)
+{
+	struct amba_device *pcdev = to_amba_device(dev);
+	int ret = pm_generic_runtime_suspend(dev);
+
+	if (ret == 0 && dev->driver) {
+		if (pm_runtime_is_irq_safe(dev))
+			clk_disable(pcdev->pclk);
+		else
+			clk_disable_unprepare(pcdev->pclk);
+	}
+
+	return ret;
+}
+
+static int amba_pm_runtime_resume(struct device *dev)
+{
+	struct amba_device *pcdev = to_amba_device(dev);
+	int ret;
+
+	if (dev->driver) {
+		if (pm_runtime_is_irq_safe(dev))
+			ret = clk_enable(pcdev->pclk);
+		else
+			ret = clk_prepare_enable(pcdev->pclk);
+		/* Failure is probably fatal to the system, but... */
+		if (ret)
+			return ret;
+	}
+
+	return pm_generic_runtime_resume(dev);
+}
+#endif /* CONFIG_PM */
+
+static const struct dev_pm_ops amba_pm = {
+	.suspend	= pm_generic_suspend,
+	.resume		= pm_generic_resume,
+	.freeze		= pm_generic_freeze,
+	.thaw		= pm_generic_thaw,
+	.poweroff	= pm_generic_poweroff,
+	.restore	= pm_generic_restore,
+	SET_RUNTIME_PM_OPS(
+		amba_pm_runtime_suspend,
+		amba_pm_runtime_resume,
+		NULL
+	)
+};
+
+/*
+ * Primecells are part of the Advanced Microcontroller Bus Architecture,
+ * so we call the bus "amba".
+ * DMA configuration for platform and AMBA bus is same. So here we reuse
+ * platform's DMA config routine.
+ */
+struct bus_type amba_bustype = {
+	.name		= "amba",
+	.dev_groups	= amba_dev_groups,
+	.match		= amba_match,
+	.uevent		= amba_uevent,
+	.probe		= amba_probe,
+	.remove		= amba_remove,
+	.shutdown	= amba_shutdown,
+	.dma_configure	= amba_dma_configure,
+	.dma_cleanup	= amba_dma_cleanup,
+	.pm		= &amba_pm,
+};
+EXPORT_SYMBOL_GPL(amba_bustype);
+
+static int __init amba_init(void)
+{
+	return bus_register(&amba_bustype);
+}
+
+postcore_initcall(amba_init);
+
+static int amba_proxy_probe(struct amba_device *adev,
+			    const struct amba_id *id)
+{
+	WARN(1, "Stub driver should never match any device.\n");
+	return -ENODEV;
+}
+
+static const struct amba_id amba_stub_drv_ids[] = {
+	{ 0, 0 },
+};
+
+static struct amba_driver amba_proxy_drv = {
+	.drv = {
+		.name = "amba-proxy",
+	},
+	.probe = amba_proxy_probe,
+	.id_table = amba_stub_drv_ids,
+};
+
+static int __init amba_stub_drv_init(void)
+{
+	if (!IS_ENABLED(CONFIG_MODULES))
+		return 0;
+
+	/*
+	 * The amba_match() function will get called only if there is at least
+	 * one amba driver registered. If all amba drivers are modules and are
+	 * only loaded based on uevents, then we'll hit a chicken-and-egg
+	 * situation where amba_match() is waiting on drivers and drivers are
+	 * waiting on amba_match(). So, register a stub driver to make sure
+	 * amba_match() is called even if no amba driver has been registered.
+	 */
+	return amba_driver_register(&amba_proxy_drv);
+}
+late_initcall_sync(amba_stub_drv_init);
+
+/**
+ *	amba_driver_register - register an AMBA device driver
+ *	@drv: amba device driver structure
+ *
+ *	Register an AMBA device driver with the Linux device model
+ *	core.  If devices pre-exist, the drivers probe function will
+ *	be called.
+ */
+int amba_driver_register(struct amba_driver *drv)
+{
+	if (!drv->probe)
+		return -EINVAL;
+
+	drv->drv.bus = &amba_bustype;
+
+	return driver_register(&drv->drv);
+}
+EXPORT_SYMBOL(amba_driver_register);
+
+/**
+ *	amba_driver_unregister - remove an AMBA device driver
+ *	@drv: AMBA device driver structure to remove
+ *
+ *	Unregister an AMBA device driver from the Linux device
+ *	model.  The device model will call the drivers remove function
+ *	for each device the device driver is currently handling.
+ */
+void amba_driver_unregister(struct amba_driver *drv)
+{
+	driver_unregister(&drv->drv);
+}
+EXPORT_SYMBOL(amba_driver_unregister);
+
+static void amba_device_release(struct device *dev)
+{
+	struct amba_device *d = to_amba_device(dev);
+
+	of_node_put(d->dev.of_node);
+	if (d->res.parent)
+		release_resource(&d->res);
+	mutex_destroy(&d->periphid_lock);
+	kfree(d);
+}
+
+/**
+ *	amba_device_add - add a previously allocated AMBA device structure
+ *	@dev: AMBA device allocated by amba_device_alloc
+ *	@parent: resource parent for this devices resources
+ *
+ *	Claim the resource, and read the device cell ID if not already
+ *	initialized.  Register the AMBA device with the Linux device
+ *	manager.
+ */
+int amba_device_add(struct amba_device *dev, struct resource *parent)
+{
+	int ret;
+
+	ret = request_resource(parent, &dev->res);
+	if (ret)
+		return ret;
+
+	/* If primecell ID isn't hard-coded, figure it out */
+	if (!dev->periphid) {
+		/*
+		 * AMBA device uevents require reading its pid and cid
+		 * registers.  To do this, the device must be on, clocked and
+		 * out of reset.  However in some cases those resources might
+		 * not yet be available.  If that's the case, we suppress the
+		 * generation of uevents until we can read the pid and cid
+		 * registers.  See also amba_match().
+		 */
+		if (amba_read_periphid(dev))
+			dev_set_uevent_suppress(&dev->dev, true);
+	}
+
+	ret = device_add(&dev->dev);
+	if (ret)
+		release_resource(&dev->res);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(amba_device_add);
+
+static void amba_device_initialize(struct amba_device *dev, const char *name)
+{
+	device_initialize(&dev->dev);
+	if (name)
+		dev_set_name(&dev->dev, "%s", name);
+	dev->dev.release = amba_device_release;
+	dev->dev.bus = &amba_bustype;
+	dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
+	dev->dev.dma_parms = &dev->dma_parms;
+	dev->res.name = dev_name(&dev->dev);
+	mutex_init(&dev->periphid_lock);
+}
+
+/**
+ *	amba_device_alloc - allocate an AMBA device
+ *	@name: sysfs name of the AMBA device
+ *	@base: base of AMBA device
+ *	@size: size of AMBA device
+ *
+ *	Allocate and initialize an AMBA device structure.  Returns %NULL
+ *	on failure.
+ */
+struct amba_device *amba_device_alloc(const char *name, resource_size_t base,
+	size_t size)
+{
+	struct amba_device *dev;
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (dev) {
+		amba_device_initialize(dev, name);
+		dev->res.start = base;
+		dev->res.end = base + size - 1;
+		dev->res.flags = IORESOURCE_MEM;
+	}
+
+	return dev;
+}
+EXPORT_SYMBOL_GPL(amba_device_alloc);
+
+/**
+ *	amba_device_register - register an AMBA device
+ *	@dev: AMBA device to register
+ *	@parent: parent memory resource
+ *
+ *	Setup the AMBA device, reading the cell ID if present.
+ *	Claim the resource, and register the AMBA device with
+ *	the Linux device manager.
+ */
+int amba_device_register(struct amba_device *dev, struct resource *parent)
+{
+	amba_device_initialize(dev, dev->dev.init_name);
+	dev->dev.init_name = NULL;
+
+	return amba_device_add(dev, parent);
+}
+EXPORT_SYMBOL(amba_device_register);
+
+/**
+ *	amba_device_put - put an AMBA device
+ *	@dev: AMBA device to put
+ */
+void amba_device_put(struct amba_device *dev)
+{
+	put_device(&dev->dev);
+}
+EXPORT_SYMBOL_GPL(amba_device_put);
+
+/**
+ *	amba_device_unregister - unregister an AMBA device
+ *	@dev: AMBA device to remove
+ *
+ *	Remove the specified AMBA device from the Linux device
+ *	manager.  All files associated with this object will be
+ *	destroyed, and device drivers notified that the device has
+ *	been removed.  The AMBA device's resources including
+ *	the amba_device structure will be freed once all
+ *	references to it have been dropped.
+ */
+void amba_device_unregister(struct amba_device *dev)
+{
+	device_unregister(&dev->dev);
+}
+EXPORT_SYMBOL(amba_device_unregister);
+
+/**
+ *	amba_request_regions - request all mem regions associated with device
+ *	@dev: amba_device structure for device
+ *	@name: name, or NULL to use driver name
+ */
+int amba_request_regions(struct amba_device *dev, const char *name)
+{
+	int ret = 0;
+	u32 size;
+
+	if (!name)
+		name = dev->dev.driver->name;
+
+	size = resource_size(&dev->res);
+
+	if (!request_mem_region(dev->res.start, size, name))
+		ret = -EBUSY;
+
+	return ret;
+}
+EXPORT_SYMBOL(amba_request_regions);
+
+/**
+ *	amba_release_regions - release mem regions associated with device
+ *	@dev: amba_device structure for device
+ *
+ *	Release regions claimed by a successful call to amba_request_regions.
+ */
+void amba_release_regions(struct amba_device *dev)
+{
+	u32 size;
+
+	size = resource_size(&dev->res);
+	release_mem_region(dev->res.start, size);
+}
+EXPORT_SYMBOL(amba_release_regions);
diff --git a/drivers/amba/tegra-ahb.c b/drivers/amba/tegra-ahb.c
new file mode 100644
index 000000000..0b2c20fdd
--- /dev/null
+++ b/drivers/amba/tegra-ahb.c
@@ -0,0 +1,289 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (C) 2011 Google, Inc.
+ *
+ * Author:
+ *	Jay Cheng <jacheng@nvidia.com>
+ *	James Wylder <james.wylder@motorola.com>
+ *	Benoit Goby <benoit@android.com>
+ *	Colin Cross <ccross@android.com>
+ *	Hiroshi DOYU <hdoyu@nvidia.com>
+ */
+
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/of.h>
+
+#include <soc/tegra/ahb.h>
+
+#define DRV_NAME "tegra-ahb"
+
+#define AHB_ARBITRATION_DISABLE		0x04
+#define AHB_ARBITRATION_PRIORITY_CTRL	0x08
+#define   AHB_PRIORITY_WEIGHT(x)	(((x) & 0x7) << 29)
+#define   PRIORITY_SELECT_USB BIT(6)
+#define   PRIORITY_SELECT_USB2 BIT(18)
+#define   PRIORITY_SELECT_USB3 BIT(17)
+
+#define AHB_GIZMO_AHB_MEM		0x10
+#define   ENB_FAST_REARBITRATE BIT(2)
+#define   DONT_SPLIT_AHB_WR     BIT(7)
+
+#define AHB_GIZMO_APB_DMA		0x14
+#define AHB_GIZMO_IDE			0x1c
+#define AHB_GIZMO_USB			0x20
+#define AHB_GIZMO_AHB_XBAR_BRIDGE	0x24
+#define AHB_GIZMO_CPU_AHB_BRIDGE	0x28
+#define AHB_GIZMO_COP_AHB_BRIDGE	0x2c
+#define AHB_GIZMO_XBAR_APB_CTLR		0x30
+#define AHB_GIZMO_VCP_AHB_BRIDGE	0x34
+#define AHB_GIZMO_NAND			0x40
+#define AHB_GIZMO_SDMMC4		0x48
+#define AHB_GIZMO_XIO			0x4c
+#define AHB_GIZMO_BSEV			0x64
+#define AHB_GIZMO_BSEA			0x74
+#define AHB_GIZMO_NOR			0x78
+#define AHB_GIZMO_USB2			0x7c
+#define AHB_GIZMO_USB3			0x80
+#define   IMMEDIATE	BIT(18)
+
+#define AHB_GIZMO_SDMMC1		0x84
+#define AHB_GIZMO_SDMMC2		0x88
+#define AHB_GIZMO_SDMMC3		0x8c
+#define AHB_MEM_PREFETCH_CFG_X		0xdc
+#define AHB_ARBITRATION_XBAR_CTRL	0xe0
+#define AHB_MEM_PREFETCH_CFG3		0xe4
+#define AHB_MEM_PREFETCH_CFG4		0xe8
+#define AHB_MEM_PREFETCH_CFG1		0xf0
+#define AHB_MEM_PREFETCH_CFG2		0xf4
+#define   PREFETCH_ENB	BIT(31)
+#define   MST_ID(x)	(((x) & 0x1f) << 26)
+#define   AHBDMA_MST_ID	MST_ID(5)
+#define   USB_MST_ID	MST_ID(6)
+#define   USB2_MST_ID	MST_ID(18)
+#define   USB3_MST_ID	MST_ID(17)
+#define   ADDR_BNDRY(x)	(((x) & 0xf) << 21)
+#define   INACTIVITY_TIMEOUT(x)	(((x) & 0xffff) << 0)
+
+#define AHB_ARBITRATION_AHB_MEM_WRQUE_MST_ID	0xfc
+
+#define AHB_ARBITRATION_XBAR_CTRL_SMMU_INIT_DONE BIT(17)
+
+/*
+ * INCORRECT_BASE_ADDR_LOW_BYTE: Legacy kernel DT files for Tegra SoCs
+ * prior to Tegra124 generally use a physical base address ending in
+ * 0x4 for the AHB IP block.  According to the TRM, the low byte
+ * should be 0x0.  During device probing, this macro is used to detect
+ * whether the passed-in physical address is incorrect, and if so, to
+ * correct it.
+ */
+#define INCORRECT_BASE_ADDR_LOW_BYTE		0x4
+
+static struct platform_driver tegra_ahb_driver;
+
+static const u32 tegra_ahb_gizmo[] = {
+	AHB_ARBITRATION_DISABLE,
+	AHB_ARBITRATION_PRIORITY_CTRL,
+	AHB_GIZMO_AHB_MEM,
+	AHB_GIZMO_APB_DMA,
+	AHB_GIZMO_IDE,
+	AHB_GIZMO_USB,
+	AHB_GIZMO_AHB_XBAR_BRIDGE,
+	AHB_GIZMO_CPU_AHB_BRIDGE,
+	AHB_GIZMO_COP_AHB_BRIDGE,
+	AHB_GIZMO_XBAR_APB_CTLR,
+	AHB_GIZMO_VCP_AHB_BRIDGE,
+	AHB_GIZMO_NAND,
+	AHB_GIZMO_SDMMC4,
+	AHB_GIZMO_XIO,
+	AHB_GIZMO_BSEV,
+	AHB_GIZMO_BSEA,
+	AHB_GIZMO_NOR,
+	AHB_GIZMO_USB2,
+	AHB_GIZMO_USB3,
+	AHB_GIZMO_SDMMC1,
+	AHB_GIZMO_SDMMC2,
+	AHB_GIZMO_SDMMC3,
+	AHB_MEM_PREFETCH_CFG_X,
+	AHB_ARBITRATION_XBAR_CTRL,
+	AHB_MEM_PREFETCH_CFG3,
+	AHB_MEM_PREFETCH_CFG4,
+	AHB_MEM_PREFETCH_CFG1,
+	AHB_MEM_PREFETCH_CFG2,
+	AHB_ARBITRATION_AHB_MEM_WRQUE_MST_ID,
+};
+
+struct tegra_ahb {
+	void __iomem	*regs;
+	struct device	*dev;
+	u32		ctx[];
+};
+
+static inline u32 gizmo_readl(struct tegra_ahb *ahb, u32 offset)
+{
+	return readl(ahb->regs + offset);
+}
+
+static inline void gizmo_writel(struct tegra_ahb *ahb, u32 value, u32 offset)
+{
+	writel(value, ahb->regs + offset);
+}
+
+#ifdef CONFIG_TEGRA_IOMMU_SMMU
+int tegra_ahb_enable_smmu(struct device_node *dn)
+{
+	struct device *dev;
+	u32 val;
+	struct tegra_ahb *ahb;
+
+	dev = driver_find_device_by_of_node(&tegra_ahb_driver.driver, dn);
+	if (!dev)
+		return -EPROBE_DEFER;
+	ahb = dev_get_drvdata(dev);
+	val = gizmo_readl(ahb, AHB_ARBITRATION_XBAR_CTRL);
+	val |= AHB_ARBITRATION_XBAR_CTRL_SMMU_INIT_DONE;
+	gizmo_writel(ahb, val, AHB_ARBITRATION_XBAR_CTRL);
+	return 0;
+}
+EXPORT_SYMBOL(tegra_ahb_enable_smmu);
+#endif
+
+static int __maybe_unused tegra_ahb_suspend(struct device *dev)
+{
+	int i;
+	struct tegra_ahb *ahb = dev_get_drvdata(dev);
+
+	for (i = 0; i < ARRAY_SIZE(tegra_ahb_gizmo); i++)
+		ahb->ctx[i] = gizmo_readl(ahb, tegra_ahb_gizmo[i]);
+	return 0;
+}
+
+static int __maybe_unused tegra_ahb_resume(struct device *dev)
+{
+	int i;
+	struct tegra_ahb *ahb = dev_get_drvdata(dev);
+
+	for (i = 0; i < ARRAY_SIZE(tegra_ahb_gizmo); i++)
+		gizmo_writel(ahb, ahb->ctx[i], tegra_ahb_gizmo[i]);
+	return 0;
+}
+
+static UNIVERSAL_DEV_PM_OPS(tegra_ahb_pm,
+			    tegra_ahb_suspend,
+			    tegra_ahb_resume, NULL);
+
+static void tegra_ahb_gizmo_init(struct tegra_ahb *ahb)
+{
+	u32 val;
+
+	val = gizmo_readl(ahb, AHB_GIZMO_AHB_MEM);
+	val |= ENB_FAST_REARBITRATE | IMMEDIATE | DONT_SPLIT_AHB_WR;
+	gizmo_writel(ahb, val, AHB_GIZMO_AHB_MEM);
+
+	val = gizmo_readl(ahb, AHB_GIZMO_USB);
+	val |= IMMEDIATE;
+	gizmo_writel(ahb, val, AHB_GIZMO_USB);
+
+	val = gizmo_readl(ahb, AHB_GIZMO_USB2);
+	val |= IMMEDIATE;
+	gizmo_writel(ahb, val, AHB_GIZMO_USB2);
+
+	val = gizmo_readl(ahb, AHB_GIZMO_USB3);
+	val |= IMMEDIATE;
+	gizmo_writel(ahb, val, AHB_GIZMO_USB3);
+
+	val = gizmo_readl(ahb, AHB_ARBITRATION_PRIORITY_CTRL);
+	val |= PRIORITY_SELECT_USB |
+		PRIORITY_SELECT_USB2 |
+		PRIORITY_SELECT_USB3 |
+		AHB_PRIORITY_WEIGHT(7);
+	gizmo_writel(ahb, val, AHB_ARBITRATION_PRIORITY_CTRL);
+
+	val = gizmo_readl(ahb, AHB_MEM_PREFETCH_CFG1);
+	val &= ~MST_ID(~0);
+	val |= PREFETCH_ENB |
+		AHBDMA_MST_ID |
+		ADDR_BNDRY(0xc) |
+		INACTIVITY_TIMEOUT(0x1000);
+	gizmo_writel(ahb, val, AHB_MEM_PREFETCH_CFG1);
+
+	val = gizmo_readl(ahb, AHB_MEM_PREFETCH_CFG2);
+	val &= ~MST_ID(~0);
+	val |= PREFETCH_ENB |
+		USB_MST_ID |
+		ADDR_BNDRY(0xc) |
+		INACTIVITY_TIMEOUT(0x1000);
+	gizmo_writel(ahb, val, AHB_MEM_PREFETCH_CFG2);
+
+	val = gizmo_readl(ahb, AHB_MEM_PREFETCH_CFG3);
+	val &= ~MST_ID(~0);
+	val |= PREFETCH_ENB |
+		USB3_MST_ID |
+		ADDR_BNDRY(0xc) |
+		INACTIVITY_TIMEOUT(0x1000);
+	gizmo_writel(ahb, val, AHB_MEM_PREFETCH_CFG3);
+
+	val = gizmo_readl(ahb, AHB_MEM_PREFETCH_CFG4);
+	val &= ~MST_ID(~0);
+	val |= PREFETCH_ENB |
+		USB2_MST_ID |
+		ADDR_BNDRY(0xc) |
+		INACTIVITY_TIMEOUT(0x1000);
+	gizmo_writel(ahb, val, AHB_MEM_PREFETCH_CFG4);
+}
+
+static int tegra_ahb_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct tegra_ahb *ahb;
+	size_t bytes;
+
+	bytes = sizeof(*ahb) + sizeof(u32) * ARRAY_SIZE(tegra_ahb_gizmo);
+	ahb = devm_kzalloc(&pdev->dev, bytes, GFP_KERNEL);
+	if (!ahb)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	/* Correct the IP block base address if necessary */
+	if (res &&
+	    (res->start & INCORRECT_BASE_ADDR_LOW_BYTE) ==
+	    INCORRECT_BASE_ADDR_LOW_BYTE) {
+		dev_warn(&pdev->dev, "incorrect AHB base address in DT data - enabling workaround\n");
+		res->start -= INCORRECT_BASE_ADDR_LOW_BYTE;
+	}
+
+	ahb->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(ahb->regs))
+		return PTR_ERR(ahb->regs);
+
+	ahb->dev = &pdev->dev;
+	platform_set_drvdata(pdev, ahb);
+	tegra_ahb_gizmo_init(ahb);
+	return 0;
+}
+
+static const struct of_device_id tegra_ahb_of_match[] = {
+	{ .compatible = "nvidia,tegra30-ahb", },
+	{ .compatible = "nvidia,tegra20-ahb", },
+	{},
+};
+
+static struct platform_driver tegra_ahb_driver = {
+	.probe = tegra_ahb_probe,
+	.driver = {
+		.name = DRV_NAME,
+		.of_match_table = tegra_ahb_of_match,
+		.pm = &tegra_ahb_pm,
+	},
+};
+module_platform_driver(tegra_ahb_driver);
+
+MODULE_AUTHOR("Hiroshi DOYU <hdoyu@nvidia.com>");
+MODULE_DESCRIPTION("Tegra AHB driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRV_NAME);