diff --git a/drivers/greybus/interface.c b/drivers/greybus/interface.c
new file mode 100644
index 0000000..67dbe6f
--- /dev/null
+++ b/drivers/greybus/interface.c
@@ -0,0 +1,1263 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Greybus interface code
+ *
+ * Copyright 2014 Google Inc.
+ * Copyright 2014 Linaro Ltd.
+ */
+
+#include <linux/delay.h>
+#include <linux/greybus.h>
+
+#include "greybus_trace.h"
+
+#define GB_INTERFACE_MODE_SWITCH_TIMEOUT	2000
+
+#define GB_INTERFACE_DEVICE_ID_BAD	0xff
+
+#define GB_INTERFACE_AUTOSUSPEND_MS			3000
+
+/* Time required for interface to enter standby before disabling REFCLK */
+#define GB_INTERFACE_SUSPEND_HIBERNATE_DELAY_MS			20
+
+/* Don't-care selector index */
+#define DME_SELECTOR_INDEX_NULL		0
+
+/* DME attributes */
+/* FIXME: remove ES2 support and DME_T_TST_SRC_INCREMENT */
+#define DME_T_TST_SRC_INCREMENT		0x4083
+
+#define DME_DDBL1_MANUFACTURERID	0x5003
+#define DME_DDBL1_PRODUCTID		0x5004
+
+#define DME_TOSHIBA_GMP_VID		0x6000
+#define DME_TOSHIBA_GMP_PID		0x6001
+#define DME_TOSHIBA_GMP_SN0		0x6002
+#define DME_TOSHIBA_GMP_SN1		0x6003
+#define DME_TOSHIBA_GMP_INIT_STATUS	0x6101
+
+/* DDBL1 Manufacturer and Product ids */
+#define TOSHIBA_DMID			0x0126
+#define TOSHIBA_ES2_BRIDGE_DPID		0x1000
+#define TOSHIBA_ES3_APBRIDGE_DPID	0x1001
+#define TOSHIBA_ES3_GBPHY_DPID	0x1002
+
+static int gb_interface_hibernate_link(struct gb_interface *intf);
+static int gb_interface_refclk_set(struct gb_interface *intf, bool enable);
+
+static int gb_interface_dme_attr_get(struct gb_interface *intf,
+				     u16 attr, u32 *val)
+{
+	return gb_svc_dme_peer_get(intf->hd->svc, intf->interface_id,
+					attr, DME_SELECTOR_INDEX_NULL, val);
+}
+
+static int gb_interface_read_ara_dme(struct gb_interface *intf)
+{
+	u32 sn0, sn1;
+	int ret;
+
+	/*
+	 * Unless this is a Toshiba bridge, bail out until we have defined
+	 * standard GMP attributes.
+	 */
+	if (intf->ddbl1_manufacturer_id != TOSHIBA_DMID) {
+		dev_err(&intf->dev, "unknown manufacturer %08x\n",
+			intf->ddbl1_manufacturer_id);
+		return -ENODEV;
+	}
+
+	ret = gb_interface_dme_attr_get(intf, DME_TOSHIBA_GMP_VID,
+					&intf->vendor_id);
+	if (ret)
+		return ret;
+
+	ret = gb_interface_dme_attr_get(intf, DME_TOSHIBA_GMP_PID,
+					&intf->product_id);
+	if (ret)
+		return ret;
+
+	ret = gb_interface_dme_attr_get(intf, DME_TOSHIBA_GMP_SN0, &sn0);
+	if (ret)
+		return ret;
+
+	ret = gb_interface_dme_attr_get(intf, DME_TOSHIBA_GMP_SN1, &sn1);
+	if (ret)
+		return ret;
+
+	intf->serial_number = (u64)sn1 << 32 | sn0;
+
+	return 0;
+}
+
+static int gb_interface_read_dme(struct gb_interface *intf)
+{
+	int ret;
+
+	/* DME attributes have already been read */
+	if (intf->dme_read)
+		return 0;
+
+	ret = gb_interface_dme_attr_get(intf, DME_DDBL1_MANUFACTURERID,
+					&intf->ddbl1_manufacturer_id);
+	if (ret)
+		return ret;
+
+	ret = gb_interface_dme_attr_get(intf, DME_DDBL1_PRODUCTID,
+					&intf->ddbl1_product_id);
+	if (ret)
+		return ret;
+
+	if (intf->ddbl1_manufacturer_id == TOSHIBA_DMID &&
+	    intf->ddbl1_product_id == TOSHIBA_ES2_BRIDGE_DPID) {
+		intf->quirks |= GB_INTERFACE_QUIRK_NO_GMP_IDS;
+		intf->quirks |= GB_INTERFACE_QUIRK_NO_INIT_STATUS;
+	}
+
+	ret = gb_interface_read_ara_dme(intf);
+	if (ret)
+		return ret;
+
+	intf->dme_read = true;
+
+	return 0;
+}
+
+static int gb_interface_route_create(struct gb_interface *intf)
+{
+	struct gb_svc *svc = intf->hd->svc;
+	u8 intf_id = intf->interface_id;
+	u8 device_id;
+	int ret;
+
+	/* Allocate an interface device id. */
+	ret = ida_simple_get(&svc->device_id_map,
+			     GB_SVC_DEVICE_ID_MIN, GB_SVC_DEVICE_ID_MAX + 1,
+			     GFP_KERNEL);
+	if (ret < 0) {
+		dev_err(&intf->dev, "failed to allocate device id: %d\n", ret);
+		return ret;
+	}
+	device_id = ret;
+
+	ret = gb_svc_intf_device_id(svc, intf_id, device_id);
+	if (ret) {
+		dev_err(&intf->dev, "failed to set device id %u: %d\n",
+			device_id, ret);
+		goto err_ida_remove;
+	}
+
+	/* FIXME: Hard-coded AP device id. */
+	ret = gb_svc_route_create(svc, svc->ap_intf_id, GB_SVC_DEVICE_ID_AP,
+				  intf_id, device_id);
+	if (ret) {
+		dev_err(&intf->dev, "failed to create route: %d\n", ret);
+		goto err_svc_id_free;
+	}
+
+	intf->device_id = device_id;
+
+	return 0;
+
+err_svc_id_free:
+	/*
+	 * XXX Should we tell SVC that this id doesn't belong to interface
+	 * XXX anymore.
+	 */
+err_ida_remove:
+	ida_simple_remove(&svc->device_id_map, device_id);
+
+	return ret;
+}
+
+static void gb_interface_route_destroy(struct gb_interface *intf)
+{
+	struct gb_svc *svc = intf->hd->svc;
+
+	if (intf->device_id == GB_INTERFACE_DEVICE_ID_BAD)
+		return;
+
+	gb_svc_route_destroy(svc, svc->ap_intf_id, intf->interface_id);
+	ida_simple_remove(&svc->device_id_map, intf->device_id);
+	intf->device_id = GB_INTERFACE_DEVICE_ID_BAD;
+}
+
+/* Locking: Caller holds the interface mutex. */
+static int gb_interface_legacy_mode_switch(struct gb_interface *intf)
+{
+	int ret;
+
+	dev_info(&intf->dev, "legacy mode switch detected\n");
+
+	/* Mark as disconnected to prevent I/O during disable. */
+	intf->disconnected = true;
+	gb_interface_disable(intf);
+	intf->disconnected = false;
+
+	ret = gb_interface_enable(intf);
+	if (ret) {
+		dev_err(&intf->dev, "failed to re-enable interface: %d\n", ret);
+		gb_interface_deactivate(intf);
+	}
+
+	return ret;
+}
+
+void gb_interface_mailbox_event(struct gb_interface *intf, u16 result,
+				u32 mailbox)
+{
+	mutex_lock(&intf->mutex);
+
+	if (result) {
+		dev_warn(&intf->dev,
+			 "mailbox event with UniPro error: 0x%04x\n",
+			 result);
+		goto err_disable;
+	}
+
+	if (mailbox != GB_SVC_INTF_MAILBOX_GREYBUS) {
+		dev_warn(&intf->dev,
+			 "mailbox event with unexpected value: 0x%08x\n",
+			 mailbox);
+		goto err_disable;
+	}
+
+	if (intf->quirks & GB_INTERFACE_QUIRK_LEGACY_MODE_SWITCH) {
+		gb_interface_legacy_mode_switch(intf);
+		goto out_unlock;
+	}
+
+	if (!intf->mode_switch) {
+		dev_warn(&intf->dev, "unexpected mailbox event: 0x%08x\n",
+			 mailbox);
+		goto err_disable;
+	}
+
+	dev_info(&intf->dev, "mode switch detected\n");
+
+	complete(&intf->mode_switch_completion);
+
+out_unlock:
+	mutex_unlock(&intf->mutex);
+
+	return;
+
+err_disable:
+	gb_interface_disable(intf);
+	gb_interface_deactivate(intf);
+	mutex_unlock(&intf->mutex);
+}
+
+static void gb_interface_mode_switch_work(struct work_struct *work)
+{
+	struct gb_interface *intf;
+	struct gb_control *control;
+	unsigned long timeout;
+	int ret;
+
+	intf = container_of(work, struct gb_interface, mode_switch_work);
+
+	mutex_lock(&intf->mutex);
+	/* Make sure interface is still enabled. */
+	if (!intf->enabled) {
+		dev_dbg(&intf->dev, "mode switch aborted\n");
+		intf->mode_switch = false;
+		mutex_unlock(&intf->mutex);
+		goto out_interface_put;
+	}
+
+	/*
+	 * Prepare the control device for mode switch and make sure to get an
+	 * extra reference before it goes away during interface disable.
+	 */
+	control = gb_control_get(intf->control);
+	gb_control_mode_switch_prepare(control);
+	gb_interface_disable(intf);
+	mutex_unlock(&intf->mutex);
+
+	timeout = msecs_to_jiffies(GB_INTERFACE_MODE_SWITCH_TIMEOUT);
+	ret = wait_for_completion_interruptible_timeout(
+			&intf->mode_switch_completion, timeout);
+
+	/* Finalise control-connection mode switch. */
+	gb_control_mode_switch_complete(control);
+	gb_control_put(control);
+
+	if (ret < 0) {
+		dev_err(&intf->dev, "mode switch interrupted\n");
+		goto err_deactivate;
+	} else if (ret == 0) {
+		dev_err(&intf->dev, "mode switch timed out\n");
+		goto err_deactivate;
+	}
+
+	/* Re-enable (re-enumerate) interface if still active. */
+	mutex_lock(&intf->mutex);
+	intf->mode_switch = false;
+	if (intf->active) {
+		ret = gb_interface_enable(intf);
+		if (ret) {
+			dev_err(&intf->dev, "failed to re-enable interface: %d\n",
+				ret);
+			gb_interface_deactivate(intf);
+		}
+	}
+	mutex_unlock(&intf->mutex);
+
+out_interface_put:
+	gb_interface_put(intf);
+
+	return;
+
+err_deactivate:
+	mutex_lock(&intf->mutex);
+	intf->mode_switch = false;
+	gb_interface_deactivate(intf);
+	mutex_unlock(&intf->mutex);
+
+	gb_interface_put(intf);
+}
+
+int gb_interface_request_mode_switch(struct gb_interface *intf)
+{
+	int ret = 0;
+
+	mutex_lock(&intf->mutex);
+	if (intf->mode_switch) {
+		ret = -EBUSY;
+		goto out_unlock;
+	}
+
+	intf->mode_switch = true;
+	reinit_completion(&intf->mode_switch_completion);
+
+	/*
+	 * Get a reference to the interface device, which will be put once the
+	 * mode switch is complete.
+	 */
+	get_device(&intf->dev);
+
+	if (!queue_work(system_long_wq, &intf->mode_switch_work)) {
+		put_device(&intf->dev);
+		ret = -EBUSY;
+		goto out_unlock;
+	}
+
+out_unlock:
+	mutex_unlock(&intf->mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(gb_interface_request_mode_switch);
+
+/*
+ * T_TstSrcIncrement is written by the module on ES2 as a stand-in for the
+ * init-status attribute DME_TOSHIBA_INIT_STATUS. The AP needs to read and
+ * clear it after reading a non-zero value from it.
+ *
+ * FIXME: This is module-hardware dependent and needs to be extended for every
+ * type of module we want to support.
+ */
+static int gb_interface_read_and_clear_init_status(struct gb_interface *intf)
+{
+	struct gb_host_device *hd = intf->hd;
+	unsigned long bootrom_quirks;
+	unsigned long s2l_quirks;
+	int ret;
+	u32 value;
+	u16 attr;
+	u8 init_status;
+
+	/*
+	 * ES2 bridges use T_TstSrcIncrement for the init status.
+	 *
+	 * FIXME: Remove ES2 support
+	 */
+	if (intf->quirks & GB_INTERFACE_QUIRK_NO_INIT_STATUS)
+		attr = DME_T_TST_SRC_INCREMENT;
+	else
+		attr = DME_TOSHIBA_GMP_INIT_STATUS;
+
+	ret = gb_svc_dme_peer_get(hd->svc, intf->interface_id, attr,
+				  DME_SELECTOR_INDEX_NULL, &value);
+	if (ret)
+		return ret;
+
+	/*
+	 * A nonzero init status indicates the module has finished
+	 * initializing.
+	 */
+	if (!value) {
+		dev_err(&intf->dev, "invalid init status\n");
+		return -ENODEV;
+	}
+
+	/*
+	 * Extract the init status.
+	 *
+	 * For ES2: We need to check lowest 8 bits of 'value'.
+	 * For ES3: We need to check highest 8 bits out of 32 of 'value'.
+	 *
+	 * FIXME: Remove ES2 support
+	 */
+	if (intf->quirks & GB_INTERFACE_QUIRK_NO_INIT_STATUS)
+		init_status = value & 0xff;
+	else
+		init_status = value >> 24;
+
+	/*
+	 * Check if the interface is executing the quirky ES3 bootrom that,
+	 * for example, requires E2EFC, CSD and CSV to be disabled.
+	 */
+	bootrom_quirks = GB_INTERFACE_QUIRK_NO_CPORT_FEATURES |
+				GB_INTERFACE_QUIRK_FORCED_DISABLE |
+				GB_INTERFACE_QUIRK_LEGACY_MODE_SWITCH |
+				GB_INTERFACE_QUIRK_NO_BUNDLE_ACTIVATE;
+
+	s2l_quirks = GB_INTERFACE_QUIRK_NO_PM;
+
+	switch (init_status) {
+	case GB_INIT_BOOTROM_UNIPRO_BOOT_STARTED:
+	case GB_INIT_BOOTROM_FALLBACK_UNIPRO_BOOT_STARTED:
+		intf->quirks |= bootrom_quirks;
+		break;
+	case GB_INIT_S2_LOADER_BOOT_STARTED:
+		/* S2 Loader doesn't support runtime PM */
+		intf->quirks &= ~bootrom_quirks;
+		intf->quirks |= s2l_quirks;
+		break;
+	default:
+		intf->quirks &= ~bootrom_quirks;
+		intf->quirks &= ~s2l_quirks;
+	}
+
+	/* Clear the init status. */
+	return gb_svc_dme_peer_set(hd->svc, intf->interface_id, attr,
+				   DME_SELECTOR_INDEX_NULL, 0);
+}
+
+/* interface sysfs attributes */
+#define gb_interface_attr(field, type)					\
+static ssize_t field##_show(struct device *dev,				\
+			    struct device_attribute *attr,		\
+			    char *buf)					\
+{									\
+	struct gb_interface *intf = to_gb_interface(dev);		\
+	return scnprintf(buf, PAGE_SIZE, type"\n", intf->field);	\
+}									\
+static DEVICE_ATTR_RO(field)
+
+gb_interface_attr(ddbl1_manufacturer_id, "0x%08x");
+gb_interface_attr(ddbl1_product_id, "0x%08x");
+gb_interface_attr(interface_id, "%u");
+gb_interface_attr(vendor_id, "0x%08x");
+gb_interface_attr(product_id, "0x%08x");
+gb_interface_attr(serial_number, "0x%016llx");
+
+static ssize_t voltage_now_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct gb_interface *intf = to_gb_interface(dev);
+	int ret;
+	u32 measurement;
+
+	ret = gb_svc_pwrmon_intf_sample_get(intf->hd->svc, intf->interface_id,
+					    GB_SVC_PWRMON_TYPE_VOL,
+					    &measurement);
+	if (ret) {
+		dev_err(&intf->dev, "failed to get voltage sample (%d)\n", ret);
+		return ret;
+	}
+
+	return sprintf(buf, "%u\n", measurement);
+}
+static DEVICE_ATTR_RO(voltage_now);
+
+static ssize_t current_now_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct gb_interface *intf = to_gb_interface(dev);
+	int ret;
+	u32 measurement;
+
+	ret = gb_svc_pwrmon_intf_sample_get(intf->hd->svc, intf->interface_id,
+					    GB_SVC_PWRMON_TYPE_CURR,
+					    &measurement);
+	if (ret) {
+		dev_err(&intf->dev, "failed to get current sample (%d)\n", ret);
+		return ret;
+	}
+
+	return sprintf(buf, "%u\n", measurement);
+}
+static DEVICE_ATTR_RO(current_now);
+
+static ssize_t power_now_show(struct device *dev,
+			      struct device_attribute *attr, char *buf)
+{
+	struct gb_interface *intf = to_gb_interface(dev);
+	int ret;
+	u32 measurement;
+
+	ret = gb_svc_pwrmon_intf_sample_get(intf->hd->svc, intf->interface_id,
+					    GB_SVC_PWRMON_TYPE_PWR,
+					    &measurement);
+	if (ret) {
+		dev_err(&intf->dev, "failed to get power sample (%d)\n", ret);
+		return ret;
+	}
+
+	return sprintf(buf, "%u\n", measurement);
+}
+static DEVICE_ATTR_RO(power_now);
+
+static ssize_t power_state_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct gb_interface *intf = to_gb_interface(dev);
+
+	if (intf->active)
+		return scnprintf(buf, PAGE_SIZE, "on\n");
+	else
+		return scnprintf(buf, PAGE_SIZE, "off\n");
+}
+
+static ssize_t power_state_store(struct device *dev,
+				 struct device_attribute *attr, const char *buf,
+				 size_t len)
+{
+	struct gb_interface *intf = to_gb_interface(dev);
+	bool activate;
+	int ret = 0;
+
+	if (kstrtobool(buf, &activate))
+		return -EINVAL;
+
+	mutex_lock(&intf->mutex);
+
+	if (activate == intf->active)
+		goto unlock;
+
+	if (activate) {
+		ret = gb_interface_activate(intf);
+		if (ret) {
+			dev_err(&intf->dev,
+				"failed to activate interface: %d\n", ret);
+			goto unlock;
+		}
+
+		ret = gb_interface_enable(intf);
+		if (ret) {
+			dev_err(&intf->dev,
+				"failed to enable interface: %d\n", ret);
+			gb_interface_deactivate(intf);
+			goto unlock;
+		}
+	} else {
+		gb_interface_disable(intf);
+		gb_interface_deactivate(intf);
+	}
+
+unlock:
+	mutex_unlock(&intf->mutex);
+
+	if (ret)
+		return ret;
+
+	return len;
+}
+static DEVICE_ATTR_RW(power_state);
+
+static const char *gb_interface_type_string(struct gb_interface *intf)
+{
+	static const char * const types[] = {
+		[GB_INTERFACE_TYPE_INVALID] = "invalid",
+		[GB_INTERFACE_TYPE_UNKNOWN] = "unknown",
+		[GB_INTERFACE_TYPE_DUMMY] = "dummy",
+		[GB_INTERFACE_TYPE_UNIPRO] = "unipro",
+		[GB_INTERFACE_TYPE_GREYBUS] = "greybus",
+	};
+
+	return types[intf->type];
+}
+
+static ssize_t interface_type_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct gb_interface *intf = to_gb_interface(dev);
+
+	return sprintf(buf, "%s\n", gb_interface_type_string(intf));
+}
+static DEVICE_ATTR_RO(interface_type);
+
+static struct attribute *interface_unipro_attrs[] = {
+	&dev_attr_ddbl1_manufacturer_id.attr,
+	&dev_attr_ddbl1_product_id.attr,
+	NULL
+};
+
+static struct attribute *interface_greybus_attrs[] = {
+	&dev_attr_vendor_id.attr,
+	&dev_attr_product_id.attr,
+	&dev_attr_serial_number.attr,
+	NULL
+};
+
+static struct attribute *interface_power_attrs[] = {
+	&dev_attr_voltage_now.attr,
+	&dev_attr_current_now.attr,
+	&dev_attr_power_now.attr,
+	&dev_attr_power_state.attr,
+	NULL
+};
+
+static struct attribute *interface_common_attrs[] = {
+	&dev_attr_interface_id.attr,
+	&dev_attr_interface_type.attr,
+	NULL
+};
+
+static umode_t interface_unipro_is_visible(struct kobject *kobj,
+					   struct attribute *attr, int n)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct gb_interface *intf = to_gb_interface(dev);
+
+	switch (intf->type) {
+	case GB_INTERFACE_TYPE_UNIPRO:
+	case GB_INTERFACE_TYPE_GREYBUS:
+		return attr->mode;
+	default:
+		return 0;
+	}
+}
+
+static umode_t interface_greybus_is_visible(struct kobject *kobj,
+					    struct attribute *attr, int n)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct gb_interface *intf = to_gb_interface(dev);
+
+	switch (intf->type) {
+	case GB_INTERFACE_TYPE_GREYBUS:
+		return attr->mode;
+	default:
+		return 0;
+	}
+}
+
+static umode_t interface_power_is_visible(struct kobject *kobj,
+					  struct attribute *attr, int n)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct gb_interface *intf = to_gb_interface(dev);
+
+	switch (intf->type) {
+	case GB_INTERFACE_TYPE_UNIPRO:
+	case GB_INTERFACE_TYPE_GREYBUS:
+		return attr->mode;
+	default:
+		return 0;
+	}
+}
+
+static const struct attribute_group interface_unipro_group = {
+	.is_visible	= interface_unipro_is_visible,
+	.attrs		= interface_unipro_attrs,
+};
+
+static const struct attribute_group interface_greybus_group = {
+	.is_visible	= interface_greybus_is_visible,
+	.attrs		= interface_greybus_attrs,
+};
+
+static const struct attribute_group interface_power_group = {
+	.is_visible	= interface_power_is_visible,
+	.attrs		= interface_power_attrs,
+};
+
+static const struct attribute_group interface_common_group = {
+	.attrs		= interface_common_attrs,
+};
+
+static const struct attribute_group *interface_groups[] = {
+	&interface_unipro_group,
+	&interface_greybus_group,
+	&interface_power_group,
+	&interface_common_group,
+	NULL
+};
+
+static void gb_interface_release(struct device *dev)
+{
+	struct gb_interface *intf = to_gb_interface(dev);
+
+	trace_gb_interface_release(intf);
+
+	kfree(intf);
+}
+
+#ifdef CONFIG_PM
+static int gb_interface_suspend(struct device *dev)
+{
+	struct gb_interface *intf = to_gb_interface(dev);
+	int ret;
+
+	ret = gb_control_interface_suspend_prepare(intf->control);
+	if (ret)
+		return ret;
+
+	ret = gb_control_suspend(intf->control);
+	if (ret)
+		goto err_hibernate_abort;
+
+	ret = gb_interface_hibernate_link(intf);
+	if (ret)
+		return ret;
+
+	/* Delay to allow interface to enter standby before disabling refclk */
+	msleep(GB_INTERFACE_SUSPEND_HIBERNATE_DELAY_MS);
+
+	ret = gb_interface_refclk_set(intf, false);
+	if (ret)
+		return ret;
+
+	return 0;
+
+err_hibernate_abort:
+	gb_control_interface_hibernate_abort(intf->control);
+
+	return ret;
+}
+
+static int gb_interface_resume(struct device *dev)
+{
+	struct gb_interface *intf = to_gb_interface(dev);
+	struct gb_svc *svc = intf->hd->svc;
+	int ret;
+
+	ret = gb_interface_refclk_set(intf, true);
+	if (ret)
+		return ret;
+
+	ret = gb_svc_intf_resume(svc, intf->interface_id);
+	if (ret)
+		return ret;
+
+	ret = gb_control_resume(intf->control);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int gb_interface_runtime_idle(struct device *dev)
+{
+	pm_runtime_mark_last_busy(dev);
+	pm_request_autosuspend(dev);
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops gb_interface_pm_ops = {
+	SET_RUNTIME_PM_OPS(gb_interface_suspend, gb_interface_resume,
+			   gb_interface_runtime_idle)
+};
+
+struct device_type greybus_interface_type = {
+	.name =		"greybus_interface",
+	.release =	gb_interface_release,
+	.pm =		&gb_interface_pm_ops,
+};
+
+/*
+ * A Greybus module represents a user-replaceable component on a GMP
+ * phone.  An interface is the physical connection on that module.  A
+ * module may have more than one interface.
+ *
+ * Create a gb_interface structure to represent a discovered interface.
+ * The position of interface within the Endo is encoded in "interface_id"
+ * argument.
+ *
+ * Returns a pointer to the new interfce or a null pointer if a
+ * failure occurs due to memory exhaustion.
+ */
+struct gb_interface *gb_interface_create(struct gb_module *module,
+					 u8 interface_id)
+{
+	struct gb_host_device *hd = module->hd;
+	struct gb_interface *intf;
+
+	intf = kzalloc(sizeof(*intf), GFP_KERNEL);
+	if (!intf)
+		return NULL;
+
+	intf->hd = hd;		/* XXX refcount? */
+	intf->module = module;
+	intf->interface_id = interface_id;
+	INIT_LIST_HEAD(&intf->bundles);
+	INIT_LIST_HEAD(&intf->manifest_descs);
+	mutex_init(&intf->mutex);
+	INIT_WORK(&intf->mode_switch_work, gb_interface_mode_switch_work);
+	init_completion(&intf->mode_switch_completion);
+
+	/* Invalid device id to start with */
+	intf->device_id = GB_INTERFACE_DEVICE_ID_BAD;
+
+	intf->dev.parent = &module->dev;
+	intf->dev.bus = &greybus_bus_type;
+	intf->dev.type = &greybus_interface_type;
+	intf->dev.groups = interface_groups;
+	intf->dev.dma_mask = module->dev.dma_mask;
+	device_initialize(&intf->dev);
+	dev_set_name(&intf->dev, "%s.%u", dev_name(&module->dev),
+		     interface_id);
+
+	pm_runtime_set_autosuspend_delay(&intf->dev,
+					 GB_INTERFACE_AUTOSUSPEND_MS);
+
+	trace_gb_interface_create(intf);
+
+	return intf;
+}
+
+static int gb_interface_vsys_set(struct gb_interface *intf, bool enable)
+{
+	struct gb_svc *svc = intf->hd->svc;
+	int ret;
+
+	dev_dbg(&intf->dev, "%s - %d\n", __func__, enable);
+
+	ret = gb_svc_intf_vsys_set(svc, intf->interface_id, enable);
+	if (ret) {
+		dev_err(&intf->dev, "failed to set v_sys: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int gb_interface_refclk_set(struct gb_interface *intf, bool enable)
+{
+	struct gb_svc *svc = intf->hd->svc;
+	int ret;
+
+	dev_dbg(&intf->dev, "%s - %d\n", __func__, enable);
+
+	ret = gb_svc_intf_refclk_set(svc, intf->interface_id, enable);
+	if (ret) {
+		dev_err(&intf->dev, "failed to set refclk: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int gb_interface_unipro_set(struct gb_interface *intf, bool enable)
+{
+	struct gb_svc *svc = intf->hd->svc;
+	int ret;
+
+	dev_dbg(&intf->dev, "%s - %d\n", __func__, enable);
+
+	ret = gb_svc_intf_unipro_set(svc, intf->interface_id, enable);
+	if (ret) {
+		dev_err(&intf->dev, "failed to set UniPro: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int gb_interface_activate_operation(struct gb_interface *intf,
+					   enum gb_interface_type *intf_type)
+{
+	struct gb_svc *svc = intf->hd->svc;
+	u8 type;
+	int ret;
+
+	dev_dbg(&intf->dev, "%s\n", __func__);
+
+	ret = gb_svc_intf_activate(svc, intf->interface_id, &type);
+	if (ret) {
+		dev_err(&intf->dev, "failed to activate: %d\n", ret);
+		return ret;
+	}
+
+	switch (type) {
+	case GB_SVC_INTF_TYPE_DUMMY:
+		*intf_type = GB_INTERFACE_TYPE_DUMMY;
+		/* FIXME: handle as an error for now */
+		return -ENODEV;
+	case GB_SVC_INTF_TYPE_UNIPRO:
+		*intf_type = GB_INTERFACE_TYPE_UNIPRO;
+		dev_err(&intf->dev, "interface type UniPro not supported\n");
+		/* FIXME: handle as an error for now */
+		return -ENODEV;
+	case GB_SVC_INTF_TYPE_GREYBUS:
+		*intf_type = GB_INTERFACE_TYPE_GREYBUS;
+		break;
+	default:
+		dev_err(&intf->dev, "unknown interface type: %u\n", type);
+		*intf_type = GB_INTERFACE_TYPE_UNKNOWN;
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int gb_interface_hibernate_link(struct gb_interface *intf)
+{
+	struct gb_svc *svc = intf->hd->svc;
+
+	return gb_svc_intf_set_power_mode_hibernate(svc, intf->interface_id);
+}
+
+static int _gb_interface_activate(struct gb_interface *intf,
+				  enum gb_interface_type *type)
+{
+	int ret;
+
+	*type = GB_INTERFACE_TYPE_UNKNOWN;
+
+	if (intf->ejected || intf->removed)
+		return -ENODEV;
+
+	ret = gb_interface_vsys_set(intf, true);
+	if (ret)
+		return ret;
+
+	ret = gb_interface_refclk_set(intf, true);
+	if (ret)
+		goto err_vsys_disable;
+
+	ret = gb_interface_unipro_set(intf, true);
+	if (ret)
+		goto err_refclk_disable;
+
+	ret = gb_interface_activate_operation(intf, type);
+	if (ret) {
+		switch (*type) {
+		case GB_INTERFACE_TYPE_UNIPRO:
+		case GB_INTERFACE_TYPE_GREYBUS:
+			goto err_hibernate_link;
+		default:
+			goto err_unipro_disable;
+		}
+	}
+
+	ret = gb_interface_read_dme(intf);
+	if (ret)
+		goto err_hibernate_link;
+
+	ret = gb_interface_route_create(intf);
+	if (ret)
+		goto err_hibernate_link;
+
+	intf->active = true;
+
+	trace_gb_interface_activate(intf);
+
+	return 0;
+
+err_hibernate_link:
+	gb_interface_hibernate_link(intf);
+err_unipro_disable:
+	gb_interface_unipro_set(intf, false);
+err_refclk_disable:
+	gb_interface_refclk_set(intf, false);
+err_vsys_disable:
+	gb_interface_vsys_set(intf, false);
+
+	return ret;
+}
+
+/*
+ * At present, we assume a UniPro-only module to be a Greybus module that
+ * failed to send its mailbox poke. There is some reason to believe that this
+ * is because of a bug in the ES3 bootrom.
+ *
+ * FIXME: Check if this is a Toshiba bridge before retrying?
+ */
+static int _gb_interface_activate_es3_hack(struct gb_interface *intf,
+					   enum gb_interface_type *type)
+{
+	int retries = 3;
+	int ret;
+
+	while (retries--) {
+		ret = _gb_interface_activate(intf, type);
+		if (ret == -ENODEV && *type == GB_INTERFACE_TYPE_UNIPRO)
+			continue;
+
+		break;
+	}
+
+	return ret;
+}
+
+/*
+ * Activate an interface.
+ *
+ * Locking: Caller holds the interface mutex.
+ */
+int gb_interface_activate(struct gb_interface *intf)
+{
+	enum gb_interface_type type;
+	int ret;
+
+	switch (intf->type) {
+	case GB_INTERFACE_TYPE_INVALID:
+	case GB_INTERFACE_TYPE_GREYBUS:
+		ret = _gb_interface_activate_es3_hack(intf, &type);
+		break;
+	default:
+		ret = _gb_interface_activate(intf, &type);
+	}
+
+	/* Make sure type is detected correctly during reactivation. */
+	if (intf->type != GB_INTERFACE_TYPE_INVALID) {
+		if (type != intf->type) {
+			dev_err(&intf->dev, "failed to detect interface type\n");
+
+			if (!ret)
+				gb_interface_deactivate(intf);
+
+			return -EIO;
+		}
+	} else {
+		intf->type = type;
+	}
+
+	return ret;
+}
+
+/*
+ * Deactivate an interface.
+ *
+ * Locking: Caller holds the interface mutex.
+ */
+void gb_interface_deactivate(struct gb_interface *intf)
+{
+	if (!intf->active)
+		return;
+
+	trace_gb_interface_deactivate(intf);
+
+	/* Abort any ongoing mode switch. */
+	if (intf->mode_switch)
+		complete(&intf->mode_switch_completion);
+
+	gb_interface_route_destroy(intf);
+	gb_interface_hibernate_link(intf);
+	gb_interface_unipro_set(intf, false);
+	gb_interface_refclk_set(intf, false);
+	gb_interface_vsys_set(intf, false);
+
+	intf->active = false;
+}
+
+/*
+ * Enable an interface by enabling its control connection, fetching the
+ * manifest and other information over it, and finally registering its child
+ * devices.
+ *
+ * Locking: Caller holds the interface mutex.
+ */
+int gb_interface_enable(struct gb_interface *intf)
+{
+	struct gb_control *control;
+	struct gb_bundle *bundle, *tmp;
+	int ret, size;
+	void *manifest;
+
+	ret = gb_interface_read_and_clear_init_status(intf);
+	if (ret) {
+		dev_err(&intf->dev, "failed to clear init status: %d\n", ret);
+		return ret;
+	}
+
+	/* Establish control connection */
+	control = gb_control_create(intf);
+	if (IS_ERR(control)) {
+		dev_err(&intf->dev, "failed to create control device: %ld\n",
+			PTR_ERR(control));
+		return PTR_ERR(control);
+	}
+	intf->control = control;
+
+	ret = gb_control_enable(intf->control);
+	if (ret)
+		goto err_put_control;
+
+	/* Get manifest size using control protocol on CPort */
+	size = gb_control_get_manifest_size_operation(intf);
+	if (size <= 0) {
+		dev_err(&intf->dev, "failed to get manifest size: %d\n", size);
+
+		if (size)
+			ret = size;
+		else
+			ret =  -EINVAL;
+
+		goto err_disable_control;
+	}
+
+	manifest = kmalloc(size, GFP_KERNEL);
+	if (!manifest) {
+		ret = -ENOMEM;
+		goto err_disable_control;
+	}
+
+	/* Get manifest using control protocol on CPort */
+	ret = gb_control_get_manifest_operation(intf, manifest, size);
+	if (ret) {
+		dev_err(&intf->dev, "failed to get manifest: %d\n", ret);
+		goto err_free_manifest;
+	}
+
+	/*
+	 * Parse the manifest and build up our data structures representing
+	 * what's in it.
+	 */
+	if (!gb_manifest_parse(intf, manifest, size)) {
+		dev_err(&intf->dev, "failed to parse manifest\n");
+		ret = -EINVAL;
+		goto err_destroy_bundles;
+	}
+
+	ret = gb_control_get_bundle_versions(intf->control);
+	if (ret)
+		goto err_destroy_bundles;
+
+	/* Register the control device and any bundles */
+	ret = gb_control_add(intf->control);
+	if (ret)
+		goto err_destroy_bundles;
+
+	pm_runtime_use_autosuspend(&intf->dev);
+	pm_runtime_get_noresume(&intf->dev);
+	pm_runtime_set_active(&intf->dev);
+	pm_runtime_enable(&intf->dev);
+
+	list_for_each_entry_safe_reverse(bundle, tmp, &intf->bundles, links) {
+		ret = gb_bundle_add(bundle);
+		if (ret) {
+			gb_bundle_destroy(bundle);
+			continue;
+		}
+	}
+
+	kfree(manifest);
+
+	intf->enabled = true;
+
+	pm_runtime_put(&intf->dev);
+
+	trace_gb_interface_enable(intf);
+
+	return 0;
+
+err_destroy_bundles:
+	list_for_each_entry_safe(bundle, tmp, &intf->bundles, links)
+		gb_bundle_destroy(bundle);
+err_free_manifest:
+	kfree(manifest);
+err_disable_control:
+	gb_control_disable(intf->control);
+err_put_control:
+	gb_control_put(intf->control);
+	intf->control = NULL;
+
+	return ret;
+}
+
+/*
+ * Disable an interface and destroy its bundles.
+ *
+ * Locking: Caller holds the interface mutex.
+ */
+void gb_interface_disable(struct gb_interface *intf)
+{
+	struct gb_bundle *bundle;
+	struct gb_bundle *next;
+
+	if (!intf->enabled)
+		return;
+
+	trace_gb_interface_disable(intf);
+
+	pm_runtime_get_sync(&intf->dev);
+
+	/* Set disconnected flag to avoid I/O during connection tear down. */
+	if (intf->quirks & GB_INTERFACE_QUIRK_FORCED_DISABLE)
+		intf->disconnected = true;
+
+	list_for_each_entry_safe(bundle, next, &intf->bundles, links)
+		gb_bundle_destroy(bundle);
+
+	if (!intf->mode_switch && !intf->disconnected)
+		gb_control_interface_deactivate_prepare(intf->control);
+
+	gb_control_del(intf->control);
+	gb_control_disable(intf->control);
+	gb_control_put(intf->control);
+	intf->control = NULL;
+
+	intf->enabled = false;
+
+	pm_runtime_disable(&intf->dev);
+	pm_runtime_set_suspended(&intf->dev);
+	pm_runtime_dont_use_autosuspend(&intf->dev);
+	pm_runtime_put_noidle(&intf->dev);
+}
+
+/* Register an interface. */
+int gb_interface_add(struct gb_interface *intf)
+{
+	int ret;
+
+	ret = device_add(&intf->dev);
+	if (ret) {
+		dev_err(&intf->dev, "failed to register interface: %d\n", ret);
+		return ret;
+	}
+
+	trace_gb_interface_add(intf);
+
+	dev_info(&intf->dev, "Interface added (%s)\n",
+		 gb_interface_type_string(intf));
+
+	switch (intf->type) {
+	case GB_INTERFACE_TYPE_GREYBUS:
+		dev_info(&intf->dev, "GMP VID=0x%08x, PID=0x%08x\n",
+			 intf->vendor_id, intf->product_id);
+		/* fall-through */
+	case GB_INTERFACE_TYPE_UNIPRO:
+		dev_info(&intf->dev, "DDBL1 Manufacturer=0x%08x, Product=0x%08x\n",
+			 intf->ddbl1_manufacturer_id,
+			 intf->ddbl1_product_id);
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+/* Deregister an interface. */
+void gb_interface_del(struct gb_interface *intf)
+{
+	if (device_is_registered(&intf->dev)) {
+		trace_gb_interface_del(intf);
+
+		device_del(&intf->dev);
+		dev_info(&intf->dev, "Interface removed\n");
+	}
+}
+
+void gb_interface_put(struct gb_interface *intf)
+{
+	put_device(&intf->dev);
+}