1 files changed, 363 insertions, 456 deletions

diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index c6707278a6bb..952c45ca6e48 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -1,11 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  linux/arch/arm/common/amba.c
  *
  *  Copyright (C) 2003 Deep Blue Solutions Ltd, All Rights Reserved.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
  */
 #include <linux/module.h>
 #include <linux/init.h>
@@ -15,48 +12,102 @@
 #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/property.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_const(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;
 
-#include <asm/irq.h>
+	uci = table->data;
 
-#define to_amba_driver(d)	container_of(d, struct amba_driver, drv)
+	/* 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)
 {
-	int ret = 0;
-
 	while (table->mask) {
-		ret = (dev->periphid & table->mask) == table->id;
-		if (ret)
-			break;
+		if (((dev->periphid & table->mask) == table->id) &&
+			((dev->cid != CORESIGHT_CID) ||
+			 (amba_cs_uci_id_match(table, dev))))
+			return table;
 		table++;
 	}
+	return NULL;
+}
 
-	return ret ? table : 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 int amba_match(struct device *dev, struct device_driver *drv)
+static void amba_put_disable_pclk(struct amba_device *pcdev)
 {
-	struct amba_device *pcdev = to_amba_device(dev);
-	struct amba_driver *pcdrv = to_amba_driver(drv);
+	clk_disable_unprepare(pcdev->pclk);
+	clk_put(pcdev->pclk);
+}
 
-	return amba_lookup(pcdrv->id_table, pcdev) != NULL;
+
+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 int amba_uevent(struct device *dev, struct kobj_uevent_env *env)
+static ssize_t driver_override_store(struct device *_dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t count)
 {
-	struct amba_device *pcdev = to_amba_device(dev);
-	int retval = 0;
+	struct amba_device *dev = to_amba_device(_dev);
+	int ret;
 
-	retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid);
-	if (retval)
-		return retval;
+	ret = driver_set_override(_dev, &dev->driver_override, buf, count);
+	if (ret)
+		return ret;
 
-	retval = add_uevent_var(env, "MODALIAS=amba:d%08X", pcdev->periphid);
-	return retval;
+	return count;
 }
+static DEVICE_ATTR_RW(driver_override);
 
 #define amba_attr_func(name,fmt,arg...)					\
 static ssize_t name##_show(struct device *_dev,				\
@@ -64,182 +115,271 @@ static ssize_t name##_show(struct device *_dev,				\
 {									\
 	struct amba_device *dev = to_amba_device(_dev);			\
 	return sprintf(buf, fmt, arg);					\
-}
-
-#define amba_attr(name,fmt,arg...)	\
-amba_attr_func(name,fmt,arg)		\
-static DEVICE_ATTR(name, S_IRUGO, name##_show, NULL)
+}									\
+static DEVICE_ATTR_RO(name)
 
 amba_attr_func(id, "%08x\n", dev->periphid);
-amba_attr(irq0, "%u\n", dev->irq[0]);
-amba_attr(irq1, "%u\n", dev->irq[1]);
 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 device_attribute amba_dev_attrs[] = {
-	__ATTR_RO(id),
-	__ATTR_RO(resource),
-	__ATTR_NULL,
+static struct attribute *amba_dev_attrs[] = {
+	&dev_attr_id.attr,
+	&dev_attr_resource.attr,
+	&dev_attr_driver_override.attr,
+	NULL,
 };
+ATTRIBUTE_GROUPS(amba_dev);
 
-#ifdef CONFIG_PM_SLEEP
-
-static int amba_legacy_suspend(struct device *dev, pm_message_t mesg)
+static int amba_read_periphid(struct amba_device *dev)
 {
-	struct amba_driver *adrv = to_amba_driver(dev->driver);
-	struct amba_device *adev = to_amba_device(dev);
-	int ret = 0;
+	struct reset_control *rstc;
+	u32 size, pid, cid;
+	void __iomem *tmp;
+	int i, ret;
 
-	if (dev->driver && adrv->suspend)
-		ret = adrv->suspend(adev, mesg);
+	ret = dev_pm_domain_attach(&dev->dev, PD_FLAG_ATTACH_POWER_ON);
+	if (ret) {
+		dev_dbg(&dev->dev, "can't get PM domain: %d\n", ret);
+		goto err_out;
+	}
 
-	return ret;
-}
+	ret = amba_get_enable_pclk(dev);
+	if (ret) {
+		dev_dbg(&dev->dev, "can't get pclk: %d\n", ret);
+		goto err_pm;
+	}
 
-static int amba_legacy_resume(struct device *dev)
-{
-	struct amba_driver *adrv = to_amba_driver(dev->driver);
-	struct amba_device *adev = to_amba_device(dev);
-	int ret = 0;
+	/*
+	 * 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);
 
-	if (dev->driver && adrv->resume)
-		ret = adrv->resume(adev);
+	size = resource_size(&dev->res);
+	tmp = ioremap(dev->res.start, size);
+	if (!tmp) {
+		ret = -ENOMEM;
+		goto err_clk;
+	}
 
-	return ret;
-}
+	/*
+	 * 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);
 
-#endif /* CONFIG_PM_SLEEP */
+	if (cid == CORESIGHT_CID) {
+		/* set the base to the start of the last 4k block */
+		void __iomem *csbase = tmp + size - 4096;
 
-#ifdef CONFIG_SUSPEND
+		dev->uci.devarch = readl(csbase + UCI_REG_DEVARCH_OFFSET);
+		dev->uci.devtype = readl(csbase + UCI_REG_DEVTYPE_OFFSET) & 0xff;
+	}
 
-static int amba_pm_suspend(struct device *dev)
-{
-	struct device_driver *drv = dev->driver;
-	int ret = 0;
+	if (cid == AMBA_CID || cid == CORESIGHT_CID) {
+		dev->periphid = pid;
+		dev->cid = cid;
+	}
 
-	if (!drv)
-		return 0;
+	if (!dev->periphid)
+		ret = -ENODEV;
 
-	if (drv->pm) {
-		if (drv->pm->suspend)
-			ret = drv->pm->suspend(dev);
-	} else {
-		ret = amba_legacy_suspend(dev, PMSG_SUSPEND);
-	}
+	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_pm_resume(struct device *dev)
+static int amba_match(struct device *dev, const struct device_driver *drv)
 {
-	struct device_driver *drv = dev->driver;
-	int ret = 0;
+	struct amba_device *pcdev = to_amba_device(dev);
+	const struct amba_driver *pcdrv = to_amba_driver(drv);
 
-	if (!drv)
-		return 0;
+	mutex_lock(&pcdev->periphid_lock);
+	if (!pcdev->periphid) {
+		int ret = amba_read_periphid(pcdev);
 
-	if (drv->pm) {
-		if (drv->pm->resume)
-			ret = drv->pm->resume(dev);
-	} else {
-		ret = amba_legacy_resume(dev);
+		/*
+		 * 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);
 
-	return ret;
-}
+	/* When driver_override is set, only bind to the matching driver */
+	if (pcdev->driver_override)
+		return !strcmp(pcdev->driver_override, drv->name);
 
-#else /* !CONFIG_SUSPEND */
+	return amba_lookup(pcdrv->id_table, pcdev) != NULL;
+}
 
-#define amba_pm_suspend		NULL
-#define amba_pm_resume		NULL
+static int amba_uevent(const struct device *dev, struct kobj_uevent_env *env)
+{
+	const struct amba_device *pcdev = to_amba_device(dev);
+	int retval = 0;
 
-#endif /* !CONFIG_SUSPEND */
+	retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid);
+	if (retval)
+		return retval;
 
-#ifdef CONFIG_HIBERNATE_CALLBACKS
+	retval = add_uevent_var(env, "MODALIAS=amba:d%08X", pcdev->periphid);
+	return retval;
+}
 
-static int amba_pm_freeze(struct device *dev)
+static int of_amba_device_decode_irq(struct amba_device *dev)
 {
-	struct device_driver *drv = dev->driver;
-	int ret = 0;
+	struct device_node *node = dev->dev.of_node;
+	int i, irq = 0;
 
-	if (!drv)
-		return 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;
+			}
 
-	if (drv->pm) {
-		if (drv->pm->freeze)
-			ret = drv->pm->freeze(dev);
-	} else {
-		ret = amba_legacy_suspend(dev, PMSG_FREEZE);
+			dev->irq[i] = irq;
+		}
 	}
 
-	return ret;
+	return 0;
 }
 
-static int amba_pm_thaw(struct device *dev)
+/*
+ * 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 device_driver *drv = dev->driver;
-	int ret = 0;
+	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;
 
-	if (!drv)
-		return 0;
+	do {
+		ret = of_amba_device_decode_irq(pcdev);
+		if (ret)
+			break;
 
-	if (drv->pm) {
-		if (drv->pm->thaw)
-			ret = drv->pm->thaw(dev);
-	} else {
-		ret = amba_legacy_resume(dev);
-	}
+		ret = of_clk_set_defaults(dev->of_node, false);
+		if (ret < 0)
+			break;
+
+		ret = dev_pm_domain_attach(dev, PD_FLAG_ATTACH_POWER_ON |
+						PD_FLAG_DETACH_POWER_OFF);
+		if (ret)
+			break;
+
+		ret = amba_get_enable_pclk(pcdev);
+		if (ret)
+			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);
+	} while (0);
 
 	return ret;
 }
 
-static int amba_pm_poweroff(struct device *dev)
+static void amba_remove(struct device *dev)
 {
-	struct device_driver *drv = dev->driver;
-	int ret = 0;
+	struct amba_device *pcdev = to_amba_device(dev);
+	struct amba_driver *drv = to_amba_driver(dev->driver);
 
-	if (!drv)
-		return 0;
+	pm_runtime_get_sync(dev);
+	if (drv->remove)
+		drv->remove(pcdev);
+	pm_runtime_put_noidle(dev);
 
-	if (drv->pm) {
-		if (drv->pm->poweroff)
-			ret = drv->pm->poweroff(dev);
-	} else {
-		ret = amba_legacy_suspend(dev, PMSG_HIBERNATE);
-	}
+	/* Undo the runtime PM settings in amba_probe() */
+	pm_runtime_disable(dev);
+	pm_runtime_set_suspended(dev);
+	pm_runtime_put_noidle(dev);
 
-	return ret;
+	amba_put_disable_pclk(pcdev);
 }
 
-static int amba_pm_restore(struct device *dev)
+static void amba_shutdown(struct device *dev)
 {
-	struct device_driver *drv = dev->driver;
+	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 (!drv)
-		return 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 (drv->pm) {
-		if (drv->pm->restore)
-			ret = drv->pm->restore(dev);
-	} else {
-		ret = amba_legacy_resume(dev);
+	/* @drv may not be valid when we're called from the IOMMU layer */
+	if (!ret && dev->driver && !drv->driver_managed_dma) {
+		ret = iommu_device_use_default_domain(dev);
+		if (ret)
+			arch_teardown_dma_ops(dev);
 	}
 
 	return ret;
 }
 
-#else /* !CONFIG_HIBERNATE_CALLBACKS */
-
-#define amba_pm_freeze		NULL
-#define amba_pm_thaw		NULL
-#define amba_pm_poweroff		NULL
-#define amba_pm_restore		NULL
+static void amba_dma_cleanup(struct device *dev)
+{
+	struct amba_driver *drv = to_amba_driver(dev->driver);
 
-#endif /* !CONFIG_HIBERNATE_CALLBACKS */
+	if (!drv->driver_managed_dma)
+		iommu_device_unuse_default_domain(dev);
+}
 
-#ifdef CONFIG_PM_RUNTIME
+#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
@@ -250,8 +390,12 @@ 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)
-		clk_disable(pcdev->pclk);
+	if (ret == 0 && dev->driver) {
+		if (pm_runtime_is_irq_safe(dev))
+			clk_disable(pcdev->pclk);
+		else
+			clk_disable_unprepare(pcdev->pclk);
+	}
 
 	return ret;
 }
@@ -262,7 +406,10 @@ static int amba_pm_runtime_resume(struct device *dev)
 	int ret;
 
 	if (dev->driver) {
-		ret = clk_enable(pcdev->pclk);
+		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;
@@ -270,17 +417,9 @@ static int amba_pm_runtime_resume(struct device *dev)
 
 	return pm_generic_runtime_resume(dev);
 }
-#endif
-
-#ifdef CONFIG_PM
+#endif /* CONFIG_PM */
 
 static const struct dev_pm_ops amba_pm = {
-	.suspend	= amba_pm_suspend,
-	.resume		= amba_pm_resume,
-	.freeze		= amba_pm_freeze,
-	.thaw		= amba_pm_thaw,
-	.poweroff	= amba_pm_poweroff,
-	.restore	= amba_pm_restore,
 	SET_RUNTIME_PM_OPS(
 		amba_pm_runtime_suspend,
 		amba_pm_runtime_resume,
@@ -288,25 +427,31 @@ static const struct dev_pm_ops amba_pm = {
 	)
 };
 
-#define AMBA_PM (&amba_pm)
-
-#else /* !CONFIG_PM */
-
-#define AMBA_PM	NULL
-
-#endif /* !CONFIG_PM */
-
 /*
  * 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 = {
+const struct bus_type amba_bustype = {
 	.name		= "amba",
-	.dev_attrs	= amba_dev_attrs,
+	.dev_groups	= amba_dev_groups,
 	.match		= amba_match,
 	.uevent		= amba_uevent,
-	.pm		= AMBA_PM,
+	.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);
+
+bool dev_is_amba(const struct device *dev)
+{
+	return dev->bus == &amba_bustype;
+}
+EXPORT_SYMBOL_GPL(dev_is_amba);
 
 static int __init amba_init(void)
 {
@@ -315,119 +460,63 @@ static int __init amba_init(void)
 
 postcore_initcall(amba_init);
 
-static int amba_get_enable_pclk(struct amba_device *pcdev)
+static int amba_proxy_probe(struct amba_device *adev,
+			    const struct amba_id *id)
 {
-	struct clk *pclk = clk_get(&pcdev->dev, "apb_pclk");
-	int ret;
-
-	pcdev->pclk = pclk;
-
-	if (IS_ERR(pclk))
-		return PTR_ERR(pclk);
-
-	ret = clk_prepare(pclk);
-	if (ret) {
-		clk_put(pclk);
-		return ret;
-	}
-
-	ret = clk_enable(pclk);
-	if (ret) {
-		clk_unprepare(pclk);
-		clk_put(pclk);
-	}
-
-	return ret;
-}
-
-static void amba_put_disable_pclk(struct amba_device *pcdev)
-{
-	struct clk *pclk = pcdev->pclk;
-
-	clk_disable(pclk);
-	clk_unprepare(pclk);
-	clk_put(pclk);
+	WARN(1, "Stub driver should never match any device.\n");
+	return -ENODEV;
 }
 
-/*
- * 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 = amba_get_enable_pclk(pcdev);
-		if (ret)
-			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);
-	} while (0);
+static const struct amba_id amba_stub_drv_ids[] = {
+	{ 0, 0 },
+};
 
-	return ret;
-}
+static struct amba_driver amba_proxy_drv = {
+	.drv = {
+		.name = "amba-proxy",
+	},
+	.probe = amba_proxy_probe,
+	.id_table = amba_stub_drv_ids,
+};
 
-static int amba_remove(struct device *dev)
+static int __init amba_stub_drv_init(void)
 {
-	struct amba_device *pcdev = to_amba_device(dev);
-	struct amba_driver *drv = to_amba_driver(dev->driver);
-	int ret;
-
-	pm_runtime_get_sync(dev);
-	ret = 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);
-
-	return ret;
-}
+	if (!IS_ENABLED(CONFIG_MODULES))
+		return 0;
 
-static void amba_shutdown(struct device *dev)
-{
-	struct amba_driver *drv = to_amba_driver(dev->driver);
-	drv->shutdown(to_amba_device(dev));
+	/*
+	 * 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, NULL);
 }
+late_initcall_sync(amba_stub_drv_init);
 
 /**
- *	amba_driver_register - register an AMBA device driver
+ *	__amba_driver_register - register an AMBA device driver
  *	@drv: amba device driver structure
+ *	@owner: owning module/driver
  *
  *	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)
+int __amba_driver_register(struct amba_driver *drv,
+			   struct module *owner)
 {
-	drv->drv.bus = &amba_bustype;
+	if (!drv->probe)
+		return -EINVAL;
 
-#define SETFN(fn)	if (drv->fn) drv->drv.fn = amba_##fn
-	SETFN(probe);
-	SETFN(remove);
-	SETFN(shutdown);
+	drv->drv.owner = owner;
+	drv->drv.bus = &amba_bustype;
 
 	return driver_register(&drv->drv);
 }
+EXPORT_SYMBOL(__amba_driver_register);
 
 /**
  *	amba_driver_unregister - remove an AMBA device driver
@@ -441,14 +530,16 @@ 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);
 
+	fwnode_handle_put(dev_fwnode(&d->dev));
 	if (d->res.parent)
 		release_resource(&d->res);
+	mutex_destroy(&d->periphid_lock);
 	kfree(d);
 }
 
@@ -463,155 +554,36 @@ static void amba_device_release(struct device *dev)
  */
 int amba_device_add(struct amba_device *dev, struct resource *parent)
 {
-	u32 size;
-	void __iomem *tmp;
-	int i, ret;
+	int ret;
 
-	WARN_ON(dev->irq[0] == (unsigned int)-1);
-	WARN_ON(dev->irq[1] == (unsigned int)-1);
+	fwnode_handle_get(dev_fwnode(&dev->dev));
 
 	ret = request_resource(parent, &dev->res);
 	if (ret)
-		goto err_out;
-
-	/* Hard-coded primecell ID instead of plug-n-play */
-	if (dev->periphid != 0)
-		goto skip_probe;
-
-	/*
-	 * Dynamically calculate the size of the resource
-	 * and use this for iomap
-	 */
-	size = resource_size(&dev->res);
-	tmp = ioremap(dev->res.start, size);
-	if (!tmp) {
-		ret = -ENOMEM;
-		goto err_release;
-	}
-
-	ret = amba_get_enable_pclk(dev);
-	if (ret == 0) {
-		u32 pid, cid;
+		return ret;
 
+	/* If primecell ID isn't hard-coded, figure it out */
+	if (!dev->periphid) {
 		/*
-		 * Read pid and cid based on size of resource
-		 * they are located at end of region
+		 * 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().
 		 */
-		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);
-
-		amba_put_disable_pclk(dev);
-
-		if (cid == AMBA_CID)
-			dev->periphid = pid;
-
-		if (!dev->periphid)
-			ret = -ENODEV;
+		if (amba_read_periphid(dev))
+			dev_set_uevent_suppress(&dev->dev, true);
 	}
 
-	iounmap(tmp);
-
-	if (ret)
-		goto err_release;
-
- skip_probe:
 	ret = device_add(&dev->dev);
 	if (ret)
-		goto err_release;
-
-	if (dev->irq[0])
-		ret = device_create_file(&dev->dev, &dev_attr_irq0);
-	if (ret == 0 && dev->irq[1])
-		ret = device_create_file(&dev->dev, &dev_attr_irq1);
-	if (ret == 0)
-		return ret;
-
-	device_unregister(&dev->dev);
+		release_resource(&dev->res);
 
- err_release:
-	release_resource(&dev->res);
- err_out:
 	return ret;
 }
 EXPORT_SYMBOL_GPL(amba_device_add);
 
-static struct amba_device *
-amba_aphb_device_add(struct device *parent, const char *name,
-		     resource_size_t base, size_t size, int irq1, int irq2,
-		     void *pdata, unsigned int periphid, u64 dma_mask,
-		     struct resource *resbase)
-{
-	struct amba_device *dev;
-	int ret;
-
-	dev = amba_device_alloc(name, base, size);
-	if (!dev)
-		return ERR_PTR(-ENOMEM);
-
-	dev->dma_mask = dma_mask;
-	dev->dev.coherent_dma_mask = dma_mask;
-	dev->irq[0] = irq1;
-	dev->irq[1] = irq2;
-	dev->periphid = periphid;
-	dev->dev.platform_data = pdata;
-	dev->dev.parent = parent;
-
-	ret = amba_device_add(dev, resbase);
-	if (ret) {
-		amba_device_put(dev);
-		return ERR_PTR(ret);
-	}
-
-	return dev;
-}
-
-struct amba_device *
-amba_apb_device_add(struct device *parent, const char *name,
-		    resource_size_t base, size_t size, int irq1, int irq2,
-		    void *pdata, unsigned int periphid)
-{
-	return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
-				    periphid, 0, &iomem_resource);
-}
-EXPORT_SYMBOL_GPL(amba_apb_device_add);
-
-struct amba_device *
-amba_ahb_device_add(struct device *parent, const char *name,
-		    resource_size_t base, size_t size, int irq1, int irq2,
-		    void *pdata, unsigned int periphid)
-{
-	return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
-				    periphid, ~0ULL, &iomem_resource);
-}
-EXPORT_SYMBOL_GPL(amba_ahb_device_add);
-
-struct amba_device *
-amba_apb_device_add_res(struct device *parent, const char *name,
-			resource_size_t base, size_t size, int irq1,
-			int irq2, void *pdata, unsigned int periphid,
-			struct resource *resbase)
-{
-	return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
-				    periphid, 0, resbase);
-}
-EXPORT_SYMBOL_GPL(amba_apb_device_add_res);
-
-struct amba_device *
-amba_ahb_device_add_res(struct device *parent, const char *name,
-			resource_size_t base, size_t size, int irq1,
-			int irq2, void *pdata, unsigned int periphid,
-			struct resource *resbase)
-{
-	return amba_aphb_device_add(parent, name, base, size, irq1, irq2, pdata,
-				    periphid, ~0ULL, resbase);
-}
-EXPORT_SYMBOL_GPL(amba_ahb_device_add_res);
-
-
 static void amba_device_initialize(struct amba_device *dev, const char *name)
 {
 	device_initialize(&dev->dev);
@@ -619,8 +591,10 @@ static void amba_device_initialize(struct amba_device *dev, const char *name)
 		dev_set_name(&dev->dev, "%s", name);
 	dev->dev.release = amba_device_release;
 	dev->dev.bus = &amba_bustype;
-	dev->dev.dma_mask = &dev->dma_mask;
+	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);
 }
 
 /**
@@ -663,11 +637,9 @@ int amba_device_register(struct amba_device *dev, struct resource *parent)
 	amba_device_initialize(dev, dev->dev.init_name);
 	dev->dev.init_name = NULL;
 
-	if (!dev->dev.coherent_dma_mask && dev->dma_mask)
-		dev_warn(&dev->dev, "coherent dma mask is unset\n");
-
 	return amba_device_add(dev, parent);
 }
+EXPORT_SYMBOL(amba_device_register);
 
 /**
  *	amba_device_put - put an AMBA device
@@ -694,66 +666,7 @@ void amba_device_unregister(struct amba_device *dev)
 {
 	device_unregister(&dev->dev);
 }
-
-
-struct find_data {
-	struct amba_device *dev;
-	struct device *parent;
-	const char *busid;
-	unsigned int id;
-	unsigned int mask;
-};
-
-static int amba_find_match(struct device *dev, void *data)
-{
-	struct find_data *d = data;
-	struct amba_device *pcdev = to_amba_device(dev);
-	int r;
-
-	r = (pcdev->periphid & d->mask) == d->id;
-	if (d->parent)
-		r &= d->parent == dev->parent;
-	if (d->busid)
-		r &= strcmp(dev_name(dev), d->busid) == 0;
-
-	if (r) {
-		get_device(dev);
-		d->dev = pcdev;
-	}
-
-	return r;
-}
-
-/**
- *	amba_find_device - locate an AMBA device given a bus id
- *	@busid: bus id for device (or NULL)
- *	@parent: parent device (or NULL)
- *	@id: peripheral ID (or 0)
- *	@mask: peripheral ID mask (or 0)
- *
- *	Return the AMBA device corresponding to the supplied parameters.
- *	If no device matches, returns NULL.
- *
- *	NOTE: When a valid device is found, its refcount is
- *	incremented, and must be decremented before the returned
- *	reference.
- */
-struct amba_device *
-amba_find_device(const char *busid, struct device *parent, unsigned int id,
-		 unsigned int mask)
-{
-	struct find_data data;
-
-	data.dev = NULL;
-	data.parent = parent;
-	data.busid = busid;
-	data.id = id;
-	data.mask = mask;
-
-	bus_for_each_dev(&amba_bustype, NULL, &data, amba_find_match);
-
-	return data.dev;
-}
+EXPORT_SYMBOL(amba_device_unregister);
 
 /**
  *	amba_request_regions - request all mem regions associated with device
@@ -775,6 +688,7 @@ int amba_request_regions(struct amba_device *dev, const char *name)
 
 	return ret;
 }
+EXPORT_SYMBOL(amba_request_regions);
 
 /**
  *	amba_release_regions - release mem regions associated with device
@@ -789,11 +703,4 @@ void amba_release_regions(struct amba_device *dev)
 	size = resource_size(&dev->res);
 	release_mem_region(dev->res.start, size);
 }
-
-EXPORT_SYMBOL(amba_driver_register);
-EXPORT_SYMBOL(amba_driver_unregister);
-EXPORT_SYMBOL(amba_device_register);
-EXPORT_SYMBOL(amba_device_unregister);
-EXPORT_SYMBOL(amba_find_device);
-EXPORT_SYMBOL(amba_request_regions);
 EXPORT_SYMBOL(amba_release_regions);