[patch 06/32] greybus: svc driver/watchdog

[Greg KH <gregkh@linuxfoundation.org>]

This is the Greybus SVC (a switch) driver.  It includes a simple
watchdog that if it detects that there is no more network activity on
the Unipro system, userspace will be told to restart the system.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/greybus/svc.c          | 1486 +++++++++++++++++++++++++++++++++++++++++
 drivers/greybus/svc.h          |  109 +++
 drivers/greybus/svc_watchdog.c |  198 +++++
 3 files changed, 1793 insertions(+)

--- /dev/null
+++ b/drivers/greybus/svc.c
@@ -0,0 +1,1486 @@
+/*
+ * SVC Greybus driver.
+ *
+ * Copyright 2015 Google Inc.
+ * Copyright 2015 Linaro Ltd.
+ *
+ * Released under the GPLv2 only.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/workqueue.h>
+
+#include "greybus.h"
+
+#define SVC_INTF_EJECT_TIMEOUT		9000
+#define SVC_INTF_ACTIVATE_TIMEOUT	6000
+#define SVC_INTF_RESUME_TIMEOUT		3000
+
+struct gb_svc_deferred_request {
+	struct work_struct work;
+	struct gb_operation *operation;
+};
+
+
+static int gb_svc_queue_deferred_request(struct gb_operation *operation);
+
+static ssize_t endo_id_show(struct device *dev,
+			struct device_attribute *attr, char *buf)
+{
+	struct gb_svc *svc = to_gb_svc(dev);
+
+	return sprintf(buf, "0x%04x\n", svc->endo_id);
+}
+static DEVICE_ATTR_RO(endo_id);
+
+static ssize_t ap_intf_id_show(struct device *dev,
+			struct device_attribute *attr, char *buf)
+{
+	struct gb_svc *svc = to_gb_svc(dev);
+
+	return sprintf(buf, "%u\n", svc->ap_intf_id);
+}
+static DEVICE_ATTR_RO(ap_intf_id);
+
+// FIXME
+// This is a hack, we need to do this "right" and clean the interface up
+// properly, not just forcibly yank the thing out of the system and hope for the
+// best.  But for now, people want their modules to come out without having to
+// throw the thing to the ground or get out a screwdriver.
+static ssize_t intf_eject_store(struct device *dev,
+				struct device_attribute *attr, const char *buf,
+				size_t len)
+{
+	struct gb_svc *svc = to_gb_svc(dev);
+	unsigned short intf_id;
+	int ret;
+
+	ret = kstrtou16(buf, 10, &intf_id);
+	if (ret < 0)
+		return ret;
+
+	dev_warn(dev, "Forcibly trying to eject interface %d\n", intf_id);
+
+	ret = gb_svc_intf_eject(svc, intf_id);
+	if (ret < 0)
+		return ret;
+
+	return len;
+}
+static DEVICE_ATTR_WO(intf_eject);
+
+static ssize_t watchdog_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	struct gb_svc *svc = to_gb_svc(dev);
+
+	return sprintf(buf, "%s\n",
+		       gb_svc_watchdog_enabled(svc) ? "enabled" : "disabled");
+}
+
+static ssize_t watchdog_store(struct device *dev,
+			      struct device_attribute *attr, const char *buf,
+			      size_t len)
+{
+	struct gb_svc *svc = to_gb_svc(dev);
+	int retval;
+	bool user_request;
+
+	retval = strtobool(buf, &user_request);
+	if (retval)
+		return retval;
+
+	if (user_request)
+		retval = gb_svc_watchdog_enable(svc);
+	else
+		retval = gb_svc_watchdog_disable(svc);
+	if (retval)
+		return retval;
+	return len;
+}
+static DEVICE_ATTR_RW(watchdog);
+
+static ssize_t watchdog_action_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct gb_svc *svc = to_gb_svc(dev);
+
+	if (svc->action == GB_SVC_WATCHDOG_BITE_PANIC_KERNEL)
+		return sprintf(buf, "panic\n");
+	else if (svc->action == GB_SVC_WATCHDOG_BITE_RESET_UNIPRO)
+		return sprintf(buf, "reset\n");
+
+	return -EINVAL;
+}
+
+static ssize_t watchdog_action_store(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t len)
+{
+	struct gb_svc *svc = to_gb_svc(dev);
+
+	if (sysfs_streq(buf, "panic"))
+		svc->action = GB_SVC_WATCHDOG_BITE_PANIC_KERNEL;
+	else if (sysfs_streq(buf, "reset"))
+		svc->action = GB_SVC_WATCHDOG_BITE_RESET_UNIPRO;
+	else
+		return -EINVAL;
+
+	return len;
+}
+static DEVICE_ATTR_RW(watchdog_action);
+
+static int gb_svc_pwrmon_rail_count_get(struct gb_svc *svc, u8 *value)
+{
+	struct gb_svc_pwrmon_rail_count_get_response response;
+	int ret;
+
+	ret = gb_operation_sync(svc->connection,
+				GB_SVC_TYPE_PWRMON_RAIL_COUNT_GET, NULL, 0,
+				&response, sizeof(response));
+	if (ret) {
+		dev_err(&svc->dev, "failed to get rail count: %d\n", ret);
+		return ret;
+	}
+
+	*value = response.rail_count;
+
+	return 0;
+}
+
+static int gb_svc_pwrmon_rail_names_get(struct gb_svc *svc,
+		struct gb_svc_pwrmon_rail_names_get_response *response,
+		size_t bufsize)
+{
+	int ret;
+
+	ret = gb_operation_sync(svc->connection,
+				GB_SVC_TYPE_PWRMON_RAIL_NAMES_GET, NULL, 0,
+				response, bufsize);
+	if (ret) {
+		dev_err(&svc->dev, "failed to get rail names: %d\n", ret);
+		return ret;
+	}
+
+	if (response->status != GB_SVC_OP_SUCCESS) {
+		dev_err(&svc->dev,
+			"SVC error while getting rail names: %u\n",
+			response->status);
+		return -EREMOTEIO;
+	}
+
+	return 0;
+}
+
+static int gb_svc_pwrmon_sample_get(struct gb_svc *svc, u8 rail_id,
+				    u8 measurement_type, u32 *value)
+{
+	struct gb_svc_pwrmon_sample_get_request request;
+	struct gb_svc_pwrmon_sample_get_response response;
+	int ret;
+
+	request.rail_id = rail_id;
+	request.measurement_type = measurement_type;
+
+	ret = gb_operation_sync(svc->connection, GB_SVC_TYPE_PWRMON_SAMPLE_GET,
+				&request, sizeof(request),
+				&response, sizeof(response));
+	if (ret) {
+		dev_err(&svc->dev, "failed to get rail sample: %d\n", ret);
+		return ret;
+	}
+
+	if (response.result) {
+		dev_err(&svc->dev,
+			"UniPro error while getting rail power sample (%d %d): %d\n",
+			rail_id, measurement_type, response.result);
+		switch (response.result) {
+		case GB_SVC_PWRMON_GET_SAMPLE_INVAL:
+			return -EINVAL;
+		case GB_SVC_PWRMON_GET_SAMPLE_NOSUPP:
+			return -ENOMSG;
+		default:
+			return -EREMOTEIO;
+		}
+	}
+
+	*value = le32_to_cpu(response.measurement);
+
+	return 0;
+}
+
+int gb_svc_pwrmon_intf_sample_get(struct gb_svc *svc, u8 intf_id,
+				  u8 measurement_type, u32 *value)
+{
+	struct gb_svc_pwrmon_intf_sample_get_request request;
+	struct gb_svc_pwrmon_intf_sample_get_response response;
+	int ret;
+
+	request.intf_id = intf_id;
+	request.measurement_type = measurement_type;
+
+	ret = gb_operation_sync(svc->connection,
+				GB_SVC_TYPE_PWRMON_INTF_SAMPLE_GET,
+				&request, sizeof(request),
+				&response, sizeof(response));
+	if (ret) {
+		dev_err(&svc->dev, "failed to get intf sample: %d\n", ret);
+		return ret;
+	}
+
+	if (response.result) {
+		dev_err(&svc->dev,
+			"UniPro error while getting intf power sample (%d %d): %d\n",
+			intf_id, measurement_type, response.result);
+		switch (response.result) {
+		case GB_SVC_PWRMON_GET_SAMPLE_INVAL:
+			return -EINVAL;
+		case GB_SVC_PWRMON_GET_SAMPLE_NOSUPP:
+			return -ENOMSG;
+		default:
+			return -EREMOTEIO;
+		}
+	}
+
+	*value = le32_to_cpu(response.measurement);
+
+	return 0;
+}
+
+static struct attribute *svc_attrs[] = {
+	&dev_attr_endo_id.attr,
+	&dev_attr_ap_intf_id.attr,
+	&dev_attr_intf_eject.attr,
+	&dev_attr_watchdog.attr,
+	&dev_attr_watchdog_action.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(svc);
+
+int gb_svc_intf_device_id(struct gb_svc *svc, u8 intf_id, u8 device_id)
+{
+	struct gb_svc_intf_device_id_request request;
+
+	request.intf_id = intf_id;
+	request.device_id = device_id;
+
+	return gb_operation_sync(svc->connection, GB_SVC_TYPE_INTF_DEVICE_ID,
+				 &request, sizeof(request), NULL, 0);
+}
+
+int gb_svc_intf_eject(struct gb_svc *svc, u8 intf_id)
+{
+	struct gb_svc_intf_eject_request request;
+	int ret;
+
+	request.intf_id = intf_id;
+
+	/*
+	 * The pulse width for module release in svc is long so we need to
+	 * increase the timeout so the operation will not return to soon.
+	 */
+	ret = gb_operation_sync_timeout(svc->connection,
+					GB_SVC_TYPE_INTF_EJECT, &request,
+					sizeof(request), NULL, 0,
+					SVC_INTF_EJECT_TIMEOUT);
+	if (ret) {
+		dev_err(&svc->dev, "failed to eject interface %u\n", intf_id);
+		return ret;
+	}
+
+	return 0;
+}
+
+int gb_svc_intf_vsys_set(struct gb_svc *svc, u8 intf_id, bool enable)
+{
+	struct gb_svc_intf_vsys_request request;
+	struct gb_svc_intf_vsys_response response;
+	int type, ret;
+
+	request.intf_id = intf_id;
+
+	if (enable)
+		type = GB_SVC_TYPE_INTF_VSYS_ENABLE;
+	else
+		type = GB_SVC_TYPE_INTF_VSYS_DISABLE;
+
+	ret = gb_operation_sync(svc->connection, type,
+			&request, sizeof(request),
+			&response, sizeof(response));
+	if (ret < 0)
+		return ret;
+	if (response.result_code != GB_SVC_INTF_VSYS_OK)
+		return -EREMOTEIO;
+	return 0;
+}
+
+int gb_svc_intf_refclk_set(struct gb_svc *svc, u8 intf_id, bool enable)
+{
+	struct gb_svc_intf_refclk_request request;
+	struct gb_svc_intf_refclk_response response;
+	int type, ret;
+
+	request.intf_id = intf_id;
+
+	if (enable)
+		type = GB_SVC_TYPE_INTF_REFCLK_ENABLE;
+	else
+		type = GB_SVC_TYPE_INTF_REFCLK_DISABLE;
+
+	ret = gb_operation_sync(svc->connection, type,
+			&request, sizeof(request),
+			&response, sizeof(response));
+	if (ret < 0)
+		return ret;
+	if (response.result_code != GB_SVC_INTF_REFCLK_OK)
+		return -EREMOTEIO;
+	return 0;
+}
+
+int gb_svc_intf_unipro_set(struct gb_svc *svc, u8 intf_id, bool enable)
+{
+	struct gb_svc_intf_unipro_request request;
+	struct gb_svc_intf_unipro_response response;
+	int type, ret;
+
+	request.intf_id = intf_id;
+
+	if (enable)
+		type = GB_SVC_TYPE_INTF_UNIPRO_ENABLE;
+	else
+		type = GB_SVC_TYPE_INTF_UNIPRO_DISABLE;
+
+	ret = gb_operation_sync(svc->connection, type,
+			&request, sizeof(request),
+			&response, sizeof(response));
+	if (ret < 0)
+		return ret;
+	if (response.result_code != GB_SVC_INTF_UNIPRO_OK)
+		return -EREMOTEIO;
+	return 0;
+}
+
+int gb_svc_intf_activate(struct gb_svc *svc, u8 intf_id, u8 *intf_type)
+{
+	struct gb_svc_intf_activate_request request;
+	struct gb_svc_intf_activate_response response;
+	int ret;
+
+	request.intf_id = intf_id;
+
+	ret = gb_operation_sync_timeout(svc->connection,
+			GB_SVC_TYPE_INTF_ACTIVATE,
+			&request, sizeof(request),
+			&response, sizeof(response),
+			SVC_INTF_ACTIVATE_TIMEOUT);
+	if (ret < 0)
+		return ret;
+	if (response.status != GB_SVC_OP_SUCCESS) {
+		dev_err(&svc->dev, "failed to activate interface %u: %u\n",
+				intf_id, response.status);
+		return -EREMOTEIO;
+	}
+
+	*intf_type = response.intf_type;
+
+	return 0;
+}
+
+int gb_svc_intf_resume(struct gb_svc *svc, u8 intf_id)
+{
+	struct gb_svc_intf_resume_request request;
+	struct gb_svc_intf_resume_response response;
+	int ret;
+
+	request.intf_id = intf_id;
+
+	ret = gb_operation_sync_timeout(svc->connection,
+					GB_SVC_TYPE_INTF_RESUME,
+					&request, sizeof(request),
+					&response, sizeof(response),
+					SVC_INTF_RESUME_TIMEOUT);
+	if (ret < 0) {
+		dev_err(&svc->dev, "failed to send interface resume %u: %d\n",
+			intf_id, ret);
+		return ret;
+	}
+
+	if (response.status != GB_SVC_OP_SUCCESS) {
+		dev_err(&svc->dev, "failed to resume interface %u: %u\n",
+			intf_id, response.status);
+		return -EREMOTEIO;
+	}
+
+	return 0;
+}
+
+int gb_svc_dme_peer_get(struct gb_svc *svc, u8 intf_id, u16 attr, u16 selector,
+			u32 *value)
+{
+	struct gb_svc_dme_peer_get_request request;
+	struct gb_svc_dme_peer_get_response response;
+	u16 result;
+	int ret;
+
+	request.intf_id = intf_id;
+	request.attr = cpu_to_le16(attr);
+	request.selector = cpu_to_le16(selector);
+
+	ret = gb_operation_sync(svc->connection, GB_SVC_TYPE_DME_PEER_GET,
+				&request, sizeof(request),
+				&response, sizeof(response));
+	if (ret) {
+		dev_err(&svc->dev, "failed to get DME attribute (%u 0x%04x %u): %d\n",
+				intf_id, attr, selector, ret);
+		return ret;
+	}
+
+	result = le16_to_cpu(response.result_code);
+	if (result) {
+		dev_err(&svc->dev, "UniPro error while getting DME attribute (%u 0x%04x %u): %u\n",
+				intf_id, attr, selector, result);
+		return -EREMOTEIO;
+	}
+
+	if (value)
+		*value = le32_to_cpu(response.attr_value);
+
+	return 0;
+}
+
+int gb_svc_dme_peer_set(struct gb_svc *svc, u8 intf_id, u16 attr, u16 selector,
+			u32 value)
+{
+	struct gb_svc_dme_peer_set_request request;
+	struct gb_svc_dme_peer_set_response response;
+	u16 result;
+	int ret;
+
+	request.intf_id = intf_id;
+	request.attr = cpu_to_le16(attr);
+	request.selector = cpu_to_le16(selector);
+	request.value = cpu_to_le32(value);
+
+	ret = gb_operation_sync(svc->connection, GB_SVC_TYPE_DME_PEER_SET,
+				&request, sizeof(request),
+				&response, sizeof(response));
+	if (ret) {
+		dev_err(&svc->dev, "failed to set DME attribute (%u 0x%04x %u %u): %d\n",
+				intf_id, attr, selector, value, ret);
+		return ret;
+	}
+
+	result = le16_to_cpu(response.result_code);
+	if (result) {
+		dev_err(&svc->dev, "UniPro error while setting DME attribute (%u 0x%04x %u %u): %u\n",
+				intf_id, attr, selector, value, result);
+		return -EREMOTEIO;
+	}
+
+	return 0;
+}
+
+int gb_svc_connection_create(struct gb_svc *svc,
+				u8 intf1_id, u16 cport1_id,
+				u8 intf2_id, u16 cport2_id,
+				u8 cport_flags)
+{
+	struct gb_svc_conn_create_request request;
+
+	request.intf1_id = intf1_id;
+	request.cport1_id = cpu_to_le16(cport1_id);
+	request.intf2_id = intf2_id;
+	request.cport2_id = cpu_to_le16(cport2_id);
+	request.tc = 0;		/* TC0 */
+	request.flags = cport_flags;
+
+	return gb_operation_sync(svc->connection, GB_SVC_TYPE_CONN_CREATE,
+				 &request, sizeof(request), NULL, 0);
+}
+
+void gb_svc_connection_destroy(struct gb_svc *svc, u8 intf1_id, u16 cport1_id,
+			       u8 intf2_id, u16 cport2_id)
+{
+	struct gb_svc_conn_destroy_request request;
+	struct gb_connection *connection = svc->connection;
+	int ret;
+
+	request.intf1_id = intf1_id;
+	request.cport1_id = cpu_to_le16(cport1_id);
+	request.intf2_id = intf2_id;
+	request.cport2_id = cpu_to_le16(cport2_id);
+
+	ret = gb_operation_sync(connection, GB_SVC_TYPE_CONN_DESTROY,
+				&request, sizeof(request), NULL, 0);
+	if (ret) {
+		dev_err(&svc->dev, "failed to destroy connection (%u:%u %u:%u): %d\n",
+				intf1_id, cport1_id, intf2_id, cport2_id, ret);
+	}
+}
+
+int gb_svc_timesync_enable(struct gb_svc *svc, u8 count, u64 frame_time,
+			   u32 strobe_delay, u32 refclk)
+{
+	struct gb_connection *connection = svc->connection;
+	struct gb_svc_timesync_enable_request request;
+
+	request.count = count;
+	request.frame_time = cpu_to_le64(frame_time);
+	request.strobe_delay = cpu_to_le32(strobe_delay);
+	request.refclk = cpu_to_le32(refclk);
+	return gb_operation_sync(connection,
+				 GB_SVC_TYPE_TIMESYNC_ENABLE,
+				 &request, sizeof(request), NULL, 0);
+}
+
+int gb_svc_timesync_disable(struct gb_svc *svc)
+{
+	struct gb_connection *connection = svc->connection;
+
+	return gb_operation_sync(connection,
+				 GB_SVC_TYPE_TIMESYNC_DISABLE,
+				 NULL, 0, NULL, 0);
+}
+
+int gb_svc_timesync_authoritative(struct gb_svc *svc, u64 *frame_time)
+{
+	struct gb_connection *connection = svc->connection;
+	struct gb_svc_timesync_authoritative_response response;
+	int ret, i;
+
+	ret = gb_operation_sync(connection,
+				GB_SVC_TYPE_TIMESYNC_AUTHORITATIVE, NULL, 0,
+				&response, sizeof(response));
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < GB_TIMESYNC_MAX_STROBES; i++)
+		frame_time[i] = le64_to_cpu(response.frame_time[i]);
+	return 0;
+}
+
+int gb_svc_timesync_ping(struct gb_svc *svc, u64 *frame_time)
+{
+	struct gb_connection *connection = svc->connection;
+	struct gb_svc_timesync_ping_response response;
+	int ret;
+
+	ret = gb_operation_sync(connection,
+				GB_SVC_TYPE_TIMESYNC_PING,
+				NULL, 0,
+				&response, sizeof(response));
+	if (ret < 0)
+		return ret;
+
+	*frame_time = le64_to_cpu(response.frame_time);
+	return 0;
+}
+
+int gb_svc_timesync_wake_pins_acquire(struct gb_svc *svc, u32 strobe_mask)
+{
+	struct gb_connection *connection = svc->connection;
+	struct gb_svc_timesync_wake_pins_acquire_request request;
+
+	request.strobe_mask = cpu_to_le32(strobe_mask);
+	return gb_operation_sync(connection,
+				 GB_SVC_TYPE_TIMESYNC_WAKE_PINS_ACQUIRE,
+				 &request, sizeof(request),
+				 NULL, 0);
+}
+
+int gb_svc_timesync_wake_pins_release(struct gb_svc *svc)
+{
+	struct gb_connection *connection = svc->connection;
+
+	return gb_operation_sync(connection,
+				 GB_SVC_TYPE_TIMESYNC_WAKE_PINS_RELEASE,
+				 NULL, 0, NULL, 0);
+}
+
+/* Creates bi-directional routes between the devices */
+int gb_svc_route_create(struct gb_svc *svc, u8 intf1_id, u8 dev1_id,
+			       u8 intf2_id, u8 dev2_id)
+{
+	struct gb_svc_route_create_request request;
+
+	request.intf1_id = intf1_id;
+	request.dev1_id = dev1_id;
+	request.intf2_id = intf2_id;
+	request.dev2_id = dev2_id;
+
+	return gb_operation_sync(svc->connection, GB_SVC_TYPE_ROUTE_CREATE,
+				 &request, sizeof(request), NULL, 0);
+}
+
+/* Destroys bi-directional routes between the devices */
+void gb_svc_route_destroy(struct gb_svc *svc, u8 intf1_id, u8 intf2_id)
+{
+	struct gb_svc_route_destroy_request request;
+	int ret;
+
+	request.intf1_id = intf1_id;
+	request.intf2_id = intf2_id;
+
+	ret = gb_operation_sync(svc->connection, GB_SVC_TYPE_ROUTE_DESTROY,
+				&request, sizeof(request), NULL, 0);
+	if (ret) {
+		dev_err(&svc->dev, "failed to destroy route (%u %u): %d\n",
+				intf1_id, intf2_id, ret);
+	}
+}
+
+int gb_svc_intf_set_power_mode(struct gb_svc *svc, u8 intf_id, u8 hs_series,
+			       u8 tx_mode, u8 tx_gear, u8 tx_nlanes,
+			       u8 tx_amplitude, u8 tx_hs_equalizer,
+			       u8 rx_mode, u8 rx_gear, u8 rx_nlanes,
+			       u8 flags, u32 quirks,
+			       struct gb_svc_l2_timer_cfg *local,
+			       struct gb_svc_l2_timer_cfg *remote)
+{
+	struct gb_svc_intf_set_pwrm_request request;
+	struct gb_svc_intf_set_pwrm_response response;
+	int ret;
+	u16 result_code;
+
+	memset(&request, 0, sizeof(request));
+
+	request.intf_id = intf_id;
+	request.hs_series = hs_series;
+	request.tx_mode = tx_mode;
+	request.tx_gear = tx_gear;
+	request.tx_nlanes = tx_nlanes;
+	request.tx_amplitude = tx_amplitude;
+	request.tx_hs_equalizer = tx_hs_equalizer;
+	request.rx_mode = rx_mode;
+	request.rx_gear = rx_gear;
+	request.rx_nlanes = rx_nlanes;
+	request.flags = flags;
+	request.quirks = cpu_to_le32(quirks);
+	if (local)
+		request.local_l2timerdata = *local;
+	if (remote)
+		request.remote_l2timerdata = *remote;
+
+	ret = gb_operation_sync(svc->connection, GB_SVC_TYPE_INTF_SET_PWRM,
+				&request, sizeof(request),
+				&response, sizeof(response));
+	if (ret < 0)
+		return ret;
+
+	result_code = response.result_code;
+	if (result_code != GB_SVC_SETPWRM_PWR_LOCAL) {
+		dev_err(&svc->dev, "set power mode = %d\n", result_code);
+		return -EIO;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(gb_svc_intf_set_power_mode);
+
+int gb_svc_intf_set_power_mode_hibernate(struct gb_svc *svc, u8 intf_id)
+{
+	struct gb_svc_intf_set_pwrm_request request;
+	struct gb_svc_intf_set_pwrm_response response;
+	int ret;
+	u16 result_code;
+
+	memset(&request, 0, sizeof(request));
+
+	request.intf_id = intf_id;
+	request.hs_series = GB_SVC_UNIPRO_HS_SERIES_A;
+	request.tx_mode = GB_SVC_UNIPRO_HIBERNATE_MODE;
+	request.rx_mode = GB_SVC_UNIPRO_HIBERNATE_MODE;
+
+	ret = gb_operation_sync(svc->connection, GB_SVC_TYPE_INTF_SET_PWRM,
+				&request, sizeof(request),
+				&response, sizeof(response));
+	if (ret < 0) {
+		dev_err(&svc->dev,
+			"failed to send set power mode operation to interface %u: %d\n",
+			intf_id, ret);
+		return ret;
+	}
+
+	result_code = response.result_code;
+	if (result_code != GB_SVC_SETPWRM_PWR_OK) {
+		dev_err(&svc->dev,
+			"failed to hibernate the link for interface %u: %u\n",
+			intf_id, result_code);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+int gb_svc_ping(struct gb_svc *svc)
+{
+	return gb_operation_sync_timeout(svc->connection, GB_SVC_TYPE_PING,
+					 NULL, 0, NULL, 0,
+					 GB_OPERATION_TIMEOUT_DEFAULT * 2);
+}
+
+static int gb_svc_version_request(struct gb_operation *op)
+{
+	struct gb_connection *connection = op->connection;
+	struct gb_svc *svc = gb_connection_get_data(connection);
+	struct gb_svc_version_request *request;
+	struct gb_svc_version_response *response;
+
+	if (op->request->payload_size < sizeof(*request)) {
+		dev_err(&svc->dev, "short version request (%zu < %zu)\n",
+				op->request->payload_size,
+				sizeof(*request));
+		return -EINVAL;
+	}
+
+	request = op->request->payload;
+
+	if (request->major > GB_SVC_VERSION_MAJOR) {
+		dev_warn(&svc->dev, "unsupported major version (%u > %u)\n",
+				request->major, GB_SVC_VERSION_MAJOR);
+		return -ENOTSUPP;
+	}
+
+	svc->protocol_major = request->major;
+	svc->protocol_minor = request->minor;
+
+	if (!gb_operation_response_alloc(op, sizeof(*response), GFP_KERNEL))
+		return -ENOMEM;
+
+	response = op->response->payload;
+	response->major = svc->protocol_major;
+	response->minor = svc->protocol_minor;
+
+	return 0;
+}
+
+static ssize_t pwr_debugfs_voltage_read(struct file *file, char __user *buf,
+					size_t len, loff_t *offset)
+{
+	struct svc_debugfs_pwrmon_rail *pwrmon_rails = file->f_inode->i_private;
+	struct gb_svc *svc = pwrmon_rails->svc;
+	int ret, desc;
+	u32 value;
+	char buff[16];
+
+	ret = gb_svc_pwrmon_sample_get(svc, pwrmon_rails->id,
+				       GB_SVC_PWRMON_TYPE_VOL, &value);
+	if (ret) {
+		dev_err(&svc->dev,
+			"failed to get voltage sample %u: %d\n",
+			pwrmon_rails->id, ret);
+		return ret;
+	}
+
+	desc = scnprintf(buff, sizeof(buff), "%u\n", value);
+
+	return simple_read_from_buffer(buf, len, offset, buff, desc);
+}
+
+static ssize_t pwr_debugfs_current_read(struct file *file, char __user *buf,
+					size_t len, loff_t *offset)
+{
+	struct svc_debugfs_pwrmon_rail *pwrmon_rails = file->f_inode->i_private;
+	struct gb_svc *svc = pwrmon_rails->svc;
+	int ret, desc;
+	u32 value;
+	char buff[16];
+
+	ret = gb_svc_pwrmon_sample_get(svc, pwrmon_rails->id,
+				       GB_SVC_PWRMON_TYPE_CURR, &value);
+	if (ret) {
+		dev_err(&svc->dev,
+			"failed to get current sample %u: %d\n",
+			pwrmon_rails->id, ret);
+		return ret;
+	}
+
+	desc = scnprintf(buff, sizeof(buff), "%u\n", value);
+
+	return simple_read_from_buffer(buf, len, offset, buff, desc);
+}
+
+static ssize_t pwr_debugfs_power_read(struct file *file, char __user *buf,
+				      size_t len, loff_t *offset)
+{
+	struct svc_debugfs_pwrmon_rail *pwrmon_rails = file->f_inode->i_private;
+	struct gb_svc *svc = pwrmon_rails->svc;
+	int ret, desc;
+	u32 value;
+	char buff[16];
+
+	ret = gb_svc_pwrmon_sample_get(svc, pwrmon_rails->id,
+				       GB_SVC_PWRMON_TYPE_PWR, &value);
+	if (ret) {
+		dev_err(&svc->dev, "failed to get power sample %u: %d\n",
+			pwrmon_rails->id, ret);
+		return ret;
+	}
+
+	desc = scnprintf(buff, sizeof(buff), "%u\n", value);
+
+	return simple_read_from_buffer(buf, len, offset, buff, desc);
+}
+
+static const struct file_operations pwrmon_debugfs_voltage_fops = {
+	.read		= pwr_debugfs_voltage_read,
+};
+
+static const struct file_operations pwrmon_debugfs_current_fops = {
+	.read		= pwr_debugfs_current_read,
+};
+
+static const struct file_operations pwrmon_debugfs_power_fops = {
+	.read		= pwr_debugfs_power_read,
+};
+
+static void gb_svc_pwrmon_debugfs_init(struct gb_svc *svc)
+{
+	int i;
+	size_t bufsize;
+	struct dentry *dent;
+	struct gb_svc_pwrmon_rail_names_get_response *rail_names;
+	u8 rail_count;
+
+	dent = debugfs_create_dir("pwrmon", svc->debugfs_dentry);
+	if (IS_ERR_OR_NULL(dent))
+		return;
+
+	if (gb_svc_pwrmon_rail_count_get(svc, &rail_count))
+		goto err_pwrmon_debugfs;
+
+	if (!rail_count || rail_count > GB_SVC_PWRMON_MAX_RAIL_COUNT)
+		goto err_pwrmon_debugfs;
+
+	bufsize = sizeof(*rail_names) +
+		GB_SVC_PWRMON_RAIL_NAME_BUFSIZE * rail_count;
+
+	rail_names = kzalloc(bufsize, GFP_KERNEL);
+	if (!rail_names)
+		goto err_pwrmon_debugfs;
+
+	svc->pwrmon_rails = kcalloc(rail_count, sizeof(*svc->pwrmon_rails),
+				    GFP_KERNEL);
+	if (!svc->pwrmon_rails)
+		goto err_pwrmon_debugfs_free;
+
+	if (gb_svc_pwrmon_rail_names_get(svc, rail_names, bufsize))
+		goto err_pwrmon_debugfs_free;
+
+	for (i = 0; i < rail_count; i++) {
+		struct dentry *dir;
+		struct svc_debugfs_pwrmon_rail *rail = &svc->pwrmon_rails[i];
+		char fname[GB_SVC_PWRMON_RAIL_NAME_BUFSIZE];
+
+		snprintf(fname, sizeof(fname), "%s",
+			 (char *)&rail_names->name[i]);
+
+		rail->id = i;
+		rail->svc = svc;
+
+		dir = debugfs_create_dir(fname, dent);
+		debugfs_create_file("voltage_now", S_IRUGO, dir, rail,
+				    &pwrmon_debugfs_voltage_fops);
+		debugfs_create_file("current_now", S_IRUGO, dir, rail,
+				    &pwrmon_debugfs_current_fops);
+		debugfs_create_file("power_now", S_IRUGO, dir, rail,
+				    &pwrmon_debugfs_power_fops);
+	}
+
+	kfree(rail_names);
+	return;
+
+err_pwrmon_debugfs_free:
+	kfree(rail_names);
+	kfree(svc->pwrmon_rails);
+	svc->pwrmon_rails = NULL;
+
+err_pwrmon_debugfs:
+	debugfs_remove(dent);
+}
+
+static void gb_svc_debugfs_init(struct gb_svc *svc)
+{
+	svc->debugfs_dentry = debugfs_create_dir(dev_name(&svc->dev),
+						 gb_debugfs_get());
+	gb_svc_pwrmon_debugfs_init(svc);
+}
+
+static void gb_svc_debugfs_exit(struct gb_svc *svc)
+{
+	debugfs_remove_recursive(svc->debugfs_dentry);
+	kfree(svc->pwrmon_rails);
+	svc->pwrmon_rails = NULL;
+}
+
+static int gb_svc_hello(struct gb_operation *op)
+{
+	struct gb_connection *connection = op->connection;
+	struct gb_svc *svc = gb_connection_get_data(connection);
+	struct gb_svc_hello_request *hello_request;
+	int ret;
+
+	if (op->request->payload_size < sizeof(*hello_request)) {
+		dev_warn(&svc->dev, "short hello request (%zu < %zu)\n",
+				op->request->payload_size,
+				sizeof(*hello_request));
+		return -EINVAL;
+	}
+
+	hello_request = op->request->payload;
+	svc->endo_id = le16_to_cpu(hello_request->endo_id);
+	svc->ap_intf_id = hello_request->interface_id;
+
+	ret = device_add(&svc->dev);
+	if (ret) {
+		dev_err(&svc->dev, "failed to register svc device: %d\n", ret);
+		return ret;
+	}
+
+	ret = gb_svc_watchdog_create(svc);
+	if (ret) {
+		dev_err(&svc->dev, "failed to create watchdog: %d\n", ret);
+		goto err_unregister_device;
+	}
+
+	gb_svc_debugfs_init(svc);
+
+	ret = gb_timesync_svc_add(svc);
+	if (ret) {
+		dev_err(&svc->dev, "failed to add SVC to timesync: %d\n", ret);
+		gb_svc_debugfs_exit(svc);
+		goto err_unregister_device;
+	}
+
+	return gb_svc_queue_deferred_request(op);
+
+err_unregister_device:
+	gb_svc_watchdog_destroy(svc);
+	device_del(&svc->dev);
+	return ret;
+}
+
+static struct gb_interface *gb_svc_interface_lookup(struct gb_svc *svc,
+							u8 intf_id)
+{
+	struct gb_host_device *hd = svc->hd;
+	struct gb_module *module;
+	size_t num_interfaces;
+	u8 module_id;
+
+	list_for_each_entry(module, &hd->modules, hd_node) {
+		module_id = module->module_id;
+		num_interfaces = module->num_interfaces;
+
+		if (intf_id >= module_id &&
+				intf_id < module_id + num_interfaces) {
+			return module->interfaces[intf_id - module_id];
+		}
+	}
+
+	return NULL;
+}
+
+static struct gb_module *gb_svc_module_lookup(struct gb_svc *svc, u8 module_id)
+{
+	struct gb_host_device *hd = svc->hd;
+	struct gb_module *module;
+
+	list_for_each_entry(module, &hd->modules, hd_node) {
+		if (module->module_id == module_id)
+			return module;
+	}
+
+	return NULL;
+}
+
+static void gb_svc_process_hello_deferred(struct gb_operation *operation)
+{
+	struct gb_connection *connection = operation->connection;
+	struct gb_svc *svc = gb_connection_get_data(connection);
+	int ret;
+
+	/*
+	 * XXX This is a hack/work-around to reconfigure the APBridgeA-Switch
+	 * link to PWM G2, 1 Lane, Slow Auto, so that it has sufficient
+	 * bandwidth for 3 audio streams plus boot-over-UniPro of a hot-plugged
+	 * module.
+	 *
+	 * The code should be removed once SW-2217, Heuristic for UniPro
+	 * Power Mode Changes is resolved.
+	 */
+	ret = gb_svc_intf_set_power_mode(svc, svc->ap_intf_id,
+					GB_SVC_UNIPRO_HS_SERIES_A,
+					GB_SVC_UNIPRO_SLOW_AUTO_MODE,
+					2, 1,
+					GB_SVC_SMALL_AMPLITUDE, GB_SVC_NO_DE_EMPHASIS,
+					GB_SVC_UNIPRO_SLOW_AUTO_MODE,
+					2, 1,
+					0, 0,
+					NULL, NULL);
+
+	if (ret)
+		dev_warn(&svc->dev,
+			"power mode change failed on AP to switch link: %d\n",
+			ret);
+}
+
+static void gb_svc_process_module_inserted(struct gb_operation *operation)
+{
+	struct gb_svc_module_inserted_request *request;
+	struct gb_connection *connection = operation->connection;
+	struct gb_svc *svc = gb_connection_get_data(connection);
+	struct gb_host_device *hd = svc->hd;
+	struct gb_module *module;
+	size_t num_interfaces;
+	u8 module_id;
+	u16 flags;
+	int ret;
+
+	/* The request message size has already been verified. */
+	request = operation->request->payload;
+	module_id = request->primary_intf_id;
+	num_interfaces = request->intf_count;
+	flags = le16_to_cpu(request->flags);
+
+	dev_dbg(&svc->dev, "%s - id = %u, num_interfaces = %zu, flags = 0x%04x\n",
+			__func__, module_id, num_interfaces, flags);
+
+	if (flags & GB_SVC_MODULE_INSERTED_FLAG_NO_PRIMARY) {
+		dev_warn(&svc->dev, "no primary interface detected on module %u\n",
+				module_id);
+	}
+
+	module = gb_svc_module_lookup(svc, module_id);
+	if (module) {
+		dev_warn(&svc->dev, "unexpected module-inserted event %u\n",
+				module_id);
+		return;
+	}
+
+	module = gb_module_create(hd, module_id, num_interfaces);
+	if (!module) {
+		dev_err(&svc->dev, "failed to create module\n");
+		return;
+	}
+
+	ret = gb_module_add(module);
+	if (ret) {
+		gb_module_put(module);
+		return;
+	}
+
+	list_add(&module->hd_node, &hd->modules);
+}
+
+static void gb_svc_process_module_removed(struct gb_operation *operation)
+{
+	struct gb_svc_module_removed_request *request;
+	struct gb_connection *connection = operation->connection;
+	struct gb_svc *svc = gb_connection_get_data(connection);
+	struct gb_module *module;
+	u8 module_id;
+
+	/* The request message size has already been verified. */
+	request = operation->request->payload;
+	module_id = request->primary_intf_id;
+
+	dev_dbg(&svc->dev, "%s - id = %u\n", __func__, module_id);
+
+	module = gb_svc_module_lookup(svc, module_id);
+	if (!module) {
+		dev_warn(&svc->dev, "unexpected module-removed event %u\n",
+				module_id);
+		return;
+	}
+
+	module->disconnected = true;
+
+	gb_module_del(module);
+	list_del(&module->hd_node);
+	gb_module_put(module);
+}
+
+static void gb_svc_process_intf_oops(struct gb_operation *operation)
+{
+	struct gb_svc_intf_oops_request *request;
+	struct gb_connection *connection = operation->connection;
+	struct gb_svc *svc = gb_connection_get_data(connection);
+	struct gb_interface *intf;
+	u8 intf_id;
+	u8 reason;
+
+	/* The request message size has already been verified. */
+	request = operation->request->payload;
+	intf_id = request->intf_id;
+	reason = request->reason;
+
+	intf = gb_svc_interface_lookup(svc, intf_id);
+	if (!intf) {
+		dev_warn(&svc->dev, "unexpected interface-oops event %u\n",
+			 intf_id);
+		return;
+	}
+
+	dev_info(&svc->dev, "Deactivating interface %u, interface oops reason = %u\n",
+		 intf_id, reason);
+
+	mutex_lock(&intf->mutex);
+	intf->disconnected = true;
+	gb_interface_disable(intf);
+	gb_interface_deactivate(intf);
+	mutex_unlock(&intf->mutex);
+}
+
+static void gb_svc_process_intf_mailbox_event(struct gb_operation *operation)
+{
+	struct gb_svc_intf_mailbox_event_request *request;
+	struct gb_connection *connection = operation->connection;
+	struct gb_svc *svc = gb_connection_get_data(connection);
+	struct gb_interface *intf;
+	u8 intf_id;
+	u16 result_code;
+	u32 mailbox;
+
+	/* The request message size has already been verified. */
+	request = operation->request->payload;
+	intf_id = request->intf_id;
+	result_code = le16_to_cpu(request->result_code);
+	mailbox = le32_to_cpu(request->mailbox);
+
+	dev_dbg(&svc->dev, "%s - id = %u, result = 0x%04x, mailbox = 0x%08x\n",
+			__func__, intf_id, result_code, mailbox);
+
+	intf = gb_svc_interface_lookup(svc, intf_id);
+	if (!intf) {
+		dev_warn(&svc->dev, "unexpected mailbox event %u\n", intf_id);
+		return;
+	}
+
+	gb_interface_mailbox_event(intf, result_code, mailbox);
+}
+
+static void gb_svc_process_deferred_request(struct work_struct *work)
+{
+	struct gb_svc_deferred_request *dr;
+	struct gb_operation *operation;
+	struct gb_svc *svc;
+	u8 type;
+
+	dr = container_of(work, struct gb_svc_deferred_request, work);
+	operation = dr->operation;
+	svc = gb_connection_get_data(operation->connection);
+	type = operation->request->header->type;
+
+	switch (type) {
+	case GB_SVC_TYPE_SVC_HELLO:
+		gb_svc_process_hello_deferred(operation);
+		break;
+	case GB_SVC_TYPE_MODULE_INSERTED:
+		gb_svc_process_module_inserted(operation);
+		break;
+	case GB_SVC_TYPE_MODULE_REMOVED:
+		gb_svc_process_module_removed(operation);
+		break;
+	case GB_SVC_TYPE_INTF_MAILBOX_EVENT:
+		gb_svc_process_intf_mailbox_event(operation);
+		break;
+	case GB_SVC_TYPE_INTF_OOPS:
+		gb_svc_process_intf_oops(operation);
+		break;
+	default:
+		dev_err(&svc->dev, "bad deferred request type: 0x%02x\n", type);
+	}
+
+	gb_operation_put(operation);
+	kfree(dr);
+}
+
+static int gb_svc_queue_deferred_request(struct gb_operation *operation)
+{
+	struct gb_svc *svc = gb_connection_get_data(operation->connection);
+	struct gb_svc_deferred_request *dr;
+
+	dr = kmalloc(sizeof(*dr), GFP_KERNEL);
+	if (!dr)
+		return -ENOMEM;
+
+	gb_operation_get(operation);
+
+	dr->operation = operation;
+	INIT_WORK(&dr->work, gb_svc_process_deferred_request);
+
+	queue_work(svc->wq, &dr->work);
+
+	return 0;
+}
+
+static int gb_svc_intf_reset_recv(struct gb_operation *op)
+{
+	struct gb_svc *svc = gb_connection_get_data(op->connection);
+	struct gb_message *request = op->request;
+	struct gb_svc_intf_reset_request *reset;
+	u8 intf_id;
+
+	if (request->payload_size < sizeof(*reset)) {
+		dev_warn(&svc->dev, "short reset request received (%zu < %zu)\n",
+				request->payload_size, sizeof(*reset));
+		return -EINVAL;
+	}
+	reset = request->payload;
+
+	intf_id = reset->intf_id;
+
+	/* FIXME Reset the interface here */
+
+	return 0;
+}
+
+static int gb_svc_module_inserted_recv(struct gb_operation *op)
+{
+	struct gb_svc *svc = gb_connection_get_data(op->connection);
+	struct gb_svc_module_inserted_request *request;
+
+	if (op->request->payload_size < sizeof(*request)) {
+		dev_warn(&svc->dev, "short module-inserted request received (%zu < %zu)\n",
+				op->request->payload_size, sizeof(*request));
+		return -EINVAL;
+	}
+
+	request = op->request->payload;
+
+	dev_dbg(&svc->dev, "%s - id = %u\n", __func__,
+			request->primary_intf_id);
+
+	return gb_svc_queue_deferred_request(op);
+}
+
+static int gb_svc_module_removed_recv(struct gb_operation *op)
+{
+	struct gb_svc *svc = gb_connection_get_data(op->connection);
+	struct gb_svc_module_removed_request *request;
+
+	if (op->request->payload_size < sizeof(*request)) {
+		dev_warn(&svc->dev, "short module-removed request received (%zu < %zu)\n",
+				op->request->payload_size, sizeof(*request));
+		return -EINVAL;
+	}
+
+	request = op->request->payload;
+
+	dev_dbg(&svc->dev, "%s - id = %u\n", __func__,
+			request->primary_intf_id);
+
+	return gb_svc_queue_deferred_request(op);
+}
+
+static int gb_svc_intf_oops_recv(struct gb_operation *op)
+{
+	struct gb_svc *svc = gb_connection_get_data(op->connection);
+	struct gb_svc_intf_oops_request *request;
+
+	if (op->request->payload_size < sizeof(*request)) {
+		dev_warn(&svc->dev, "short intf-oops request received (%zu < %zu)\n",
+			 op->request->payload_size, sizeof(*request));
+		return -EINVAL;
+	}
+
+	return gb_svc_queue_deferred_request(op);
+}
+
+static int gb_svc_intf_mailbox_event_recv(struct gb_operation *op)
+{
+	struct gb_svc *svc = gb_connection_get_data(op->connection);
+	struct gb_svc_intf_mailbox_event_request *request;
+
+	if (op->request->payload_size < sizeof(*request)) {
+		dev_warn(&svc->dev, "short mailbox request received (%zu < %zu)\n",
+				op->request->payload_size, sizeof(*request));
+		return -EINVAL;
+	}
+
+	request = op->request->payload;
+
+	dev_dbg(&svc->dev, "%s - id = %u\n", __func__, request->intf_id);
+
+	return gb_svc_queue_deferred_request(op);
+}
+
+static int gb_svc_request_handler(struct gb_operation *op)
+{
+	struct gb_connection *connection = op->connection;
+	struct gb_svc *svc = gb_connection_get_data(connection);
+	u8 type = op->type;
+	int ret = 0;
+
+	/*
+	 * SVC requests need to follow a specific order (at least initially) and
+	 * below code takes care of enforcing that. The expected order is:
+	 * - PROTOCOL_VERSION
+	 * - SVC_HELLO
+	 * - Any other request, but the earlier two.
+	 *
+	 * Incoming requests are guaranteed to be serialized and so we don't
+	 * need to protect 'state' for any races.
+	 */
+	switch (type) {
+	case GB_SVC_TYPE_PROTOCOL_VERSION:
+		if (svc->state != GB_SVC_STATE_RESET)
+			ret = -EINVAL;
+		break;
+	case GB_SVC_TYPE_SVC_HELLO:
+		if (svc->state != GB_SVC_STATE_PROTOCOL_VERSION)
+			ret = -EINVAL;
+		break;
+	default:
+		if (svc->state != GB_SVC_STATE_SVC_HELLO)
+			ret = -EINVAL;
+		break;
+	}
+
+	if (ret) {
+		dev_warn(&svc->dev, "unexpected request 0x%02x received (state %u)\n",
+				type, svc->state);
+		return ret;
+	}
+
+	switch (type) {
+	case GB_SVC_TYPE_PROTOCOL_VERSION:
+		ret = gb_svc_version_request(op);
+		if (!ret)
+			svc->state = GB_SVC_STATE_PROTOCOL_VERSION;
+		return ret;
+	case GB_SVC_TYPE_SVC_HELLO:
+		ret = gb_svc_hello(op);
+		if (!ret)
+			svc->state = GB_SVC_STATE_SVC_HELLO;
+		return ret;
+	case GB_SVC_TYPE_INTF_RESET:
+		return gb_svc_intf_reset_recv(op);
+	case GB_SVC_TYPE_MODULE_INSERTED:
+		return gb_svc_module_inserted_recv(op);
+	case GB_SVC_TYPE_MODULE_REMOVED:
+		return gb_svc_module_removed_recv(op);
+	case GB_SVC_TYPE_INTF_MAILBOX_EVENT:
+		return gb_svc_intf_mailbox_event_recv(op);
+	case GB_SVC_TYPE_INTF_OOPS:
+		return gb_svc_intf_oops_recv(op);
+	default:
+		dev_warn(&svc->dev, "unsupported request 0x%02x\n", type);
+		return -EINVAL;
+	}
+}
+
+static void gb_svc_release(struct device *dev)
+{
+	struct gb_svc *svc = to_gb_svc(dev);
+
+	if (svc->connection)
+		gb_connection_destroy(svc->connection);
+	ida_destroy(&svc->device_id_map);
+	destroy_workqueue(svc->wq);
+	kfree(svc);
+}
+
+struct device_type greybus_svc_type = {
+	.name		= "greybus_svc",
+	.release	= gb_svc_release,
+};
+
+struct gb_svc *gb_svc_create(struct gb_host_device *hd)
+{
+	struct gb_svc *svc;
+
+	svc = kzalloc(sizeof(*svc), GFP_KERNEL);
+	if (!svc)
+		return NULL;
+
+	svc->wq = alloc_workqueue("%s:svc", WQ_UNBOUND, 1, dev_name(&hd->dev));
+	if (!svc->wq) {
+		kfree(svc);
+		return NULL;
+	}
+
+	svc->dev.parent = &hd->dev;
+	svc->dev.bus = &greybus_bus_type;
+	svc->dev.type = &greybus_svc_type;
+	svc->dev.groups = svc_groups;
+	svc->dev.dma_mask = svc->dev.parent->dma_mask;
+	device_initialize(&svc->dev);
+
+	dev_set_name(&svc->dev, "%d-svc", hd->bus_id);
+
+	ida_init(&svc->device_id_map);
+	svc->state = GB_SVC_STATE_RESET;
+	svc->hd = hd;
+
+	svc->connection = gb_connection_create_static(hd, GB_SVC_CPORT_ID,
+						gb_svc_request_handler);
+	if (IS_ERR(svc->connection)) {
+		dev_err(&svc->dev, "failed to create connection: %ld\n",
+				PTR_ERR(svc->connection));
+		goto err_put_device;
+	}
+
+	gb_connection_set_data(svc->connection, svc);
+
+	return svc;
+
+err_put_device:
+	put_device(&svc->dev);
+	return NULL;
+}
+
+int gb_svc_add(struct gb_svc *svc)
+{
+	int ret;
+
+	/*
+	 * The SVC protocol is currently driven by the SVC, so the SVC device
+	 * is added from the connection request handler when enough
+	 * information has been received.
+	 */
+	ret = gb_connection_enable(svc->connection);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static void gb_svc_remove_modules(struct gb_svc *svc)
+{
+	struct gb_host_device *hd = svc->hd;
+	struct gb_module *module, *tmp;
+
+	list_for_each_entry_safe(module, tmp, &hd->modules, hd_node) {
+		gb_module_del(module);
+		list_del(&module->hd_node);
+		gb_module_put(module);
+	}
+}
+
+void gb_svc_del(struct gb_svc *svc)
+{
+	gb_connection_disable_rx(svc->connection);
+
+	/*
+	 * The SVC device may have been registered from the request handler.
+	 */
+	if (device_is_registered(&svc->dev)) {
+		gb_timesync_svc_remove(svc);
+		gb_svc_debugfs_exit(svc);
+		gb_svc_watchdog_destroy(svc);
+		device_del(&svc->dev);
+	}
+
+	flush_workqueue(svc->wq);
+
+	gb_svc_remove_modules(svc);
+
+	gb_connection_disable(svc->connection);
+}
+
+void gb_svc_put(struct gb_svc *svc)
+{
+	put_device(&svc->dev);
+}
--- /dev/null
+++ b/drivers/greybus/svc.h
@@ -0,0 +1,109 @@
+/*
+ * Greybus SVC code
+ *
+ * Copyright 2015 Google Inc.
+ * Copyright 2015 Linaro Ltd.
+ *
+ * Released under the GPLv2 only.
+ */
+
+#ifndef __SVC_H
+#define __SVC_H
+
+#define GB_SVC_CPORT_FLAG_E2EFC		BIT(0)
+#define GB_SVC_CPORT_FLAG_CSD_N		BIT(1)
+#define GB_SVC_CPORT_FLAG_CSV_N		BIT(2)
+
+enum gb_svc_state {
+	GB_SVC_STATE_RESET,
+	GB_SVC_STATE_PROTOCOL_VERSION,
+	GB_SVC_STATE_SVC_HELLO,
+};
+
+enum gb_svc_watchdog_bite {
+	GB_SVC_WATCHDOG_BITE_RESET_UNIPRO = 0,
+	GB_SVC_WATCHDOG_BITE_PANIC_KERNEL,
+};
+
+struct gb_svc_watchdog;
+
+struct svc_debugfs_pwrmon_rail {
+	u8 id;
+	struct gb_svc *svc;
+};
+
+struct gb_svc {
+	struct device		dev;
+
+	struct gb_host_device	*hd;
+	struct gb_connection	*connection;
+	enum gb_svc_state	state;
+	struct ida		device_id_map;
+	struct workqueue_struct	*wq;
+
+	u16 endo_id;
+	u8 ap_intf_id;
+
+	u8 protocol_major;
+	u8 protocol_minor;
+
+	struct gb_svc_watchdog	*watchdog;
+	enum gb_svc_watchdog_bite action;
+
+	struct dentry *debugfs_dentry;
+	struct svc_debugfs_pwrmon_rail *pwrmon_rails;
+};
+#define to_gb_svc(d) container_of(d, struct gb_svc, dev)
+
+struct gb_svc *gb_svc_create(struct gb_host_device *hd);
+int gb_svc_add(struct gb_svc *svc);
+void gb_svc_del(struct gb_svc *svc);
+void gb_svc_put(struct gb_svc *svc);
+
+int gb_svc_pwrmon_intf_sample_get(struct gb_svc *svc, u8 intf_id,
+				  u8 measurement_type, u32 *value);
+int gb_svc_intf_device_id(struct gb_svc *svc, u8 intf_id, u8 device_id);
+int gb_svc_route_create(struct gb_svc *svc, u8 intf1_id, u8 dev1_id,
+			       u8 intf2_id, u8 dev2_id);
+void gb_svc_route_destroy(struct gb_svc *svc, u8 intf1_id, u8 intf2_id);
+int gb_svc_connection_create(struct gb_svc *svc, u8 intf1_id, u16 cport1_id,
+			     u8 intf2_id, u16 cport2_id, u8 cport_flags);
+void gb_svc_connection_destroy(struct gb_svc *svc, u8 intf1_id, u16 cport1_id,
+			       u8 intf2_id, u16 cport2_id);
+int gb_svc_intf_eject(struct gb_svc *svc, u8 intf_id);
+int gb_svc_intf_vsys_set(struct gb_svc *svc, u8 intf_id, bool enable);
+int gb_svc_intf_refclk_set(struct gb_svc *svc, u8 intf_id, bool enable);
+int gb_svc_intf_unipro_set(struct gb_svc *svc, u8 intf_id, bool enable);
+int gb_svc_intf_activate(struct gb_svc *svc, u8 intf_id, u8 *intf_type);
+int gb_svc_intf_resume(struct gb_svc *svc, u8 intf_id);
+
+int gb_svc_dme_peer_get(struct gb_svc *svc, u8 intf_id, u16 attr, u16 selector,
+			u32 *value);
+int gb_svc_dme_peer_set(struct gb_svc *svc, u8 intf_id, u16 attr, u16 selector,
+			u32 value);
+int gb_svc_intf_set_power_mode(struct gb_svc *svc, u8 intf_id, u8 hs_series,
+			       u8 tx_mode, u8 tx_gear, u8 tx_nlanes,
+			       u8 tx_amplitude, u8 tx_hs_equalizer,
+			       u8 rx_mode, u8 rx_gear, u8 rx_nlanes,
+			       u8 flags, u32 quirks,
+			       struct gb_svc_l2_timer_cfg *local,
+			       struct gb_svc_l2_timer_cfg *remote);
+int gb_svc_intf_set_power_mode_hibernate(struct gb_svc *svc, u8 intf_id);
+int gb_svc_ping(struct gb_svc *svc);
+int gb_svc_watchdog_create(struct gb_svc *svc);
+void gb_svc_watchdog_destroy(struct gb_svc *svc);
+bool gb_svc_watchdog_enabled(struct gb_svc *svc);
+int gb_svc_watchdog_enable(struct gb_svc *svc);
+int gb_svc_watchdog_disable(struct gb_svc *svc);
+int gb_svc_timesync_enable(struct gb_svc *svc, u8 count, u64 frame_time,
+			   u32 strobe_delay, u32 refclk);
+int gb_svc_timesync_disable(struct gb_svc *svc);
+int gb_svc_timesync_authoritative(struct gb_svc *svc, u64 *frame_time);
+int gb_svc_timesync_ping(struct gb_svc *svc, u64 *frame_time);
+int gb_svc_timesync_wake_pins_acquire(struct gb_svc *svc, u32 strobe_mask);
+int gb_svc_timesync_wake_pins_release(struct gb_svc *svc);
+
+int gb_svc_protocol_init(void);
+void gb_svc_protocol_exit(void);
+
+#endif /* __SVC_H */
--- /dev/null
+++ b/drivers/greybus/svc_watchdog.c
@@ -0,0 +1,198 @@
+/*
+ * SVC Greybus "watchdog" driver.
+ *
+ * Copyright 2016 Google Inc.
+ *
+ * Released under the GPLv2 only.
+ */
+
+#include <linux/delay.h>
+#include <linux/suspend.h>
+#include <linux/workqueue.h>
+#include "greybus.h"
+
+#define SVC_WATCHDOG_PERIOD	(2*HZ)
+
+struct gb_svc_watchdog {
+	struct delayed_work	work;
+	struct gb_svc		*svc;
+	bool			enabled;
+	struct notifier_block pm_notifier;
+};
+
+static struct delayed_work reset_work;
+
+static int svc_watchdog_pm_notifier(struct notifier_block *notifier,
+				    unsigned long pm_event, void *unused)
+{
+	struct gb_svc_watchdog *watchdog =
+		container_of(notifier, struct gb_svc_watchdog, pm_notifier);
+
+	switch (pm_event) {
+	case PM_SUSPEND_PREPARE:
+		gb_svc_watchdog_disable(watchdog->svc);
+		break;
+	case PM_POST_SUSPEND:
+		gb_svc_watchdog_enable(watchdog->svc);
+		break;
+	default:
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static void greybus_reset(struct work_struct *work)
+{
+	static char start_path[256] = "/system/bin/start";
+	static char *envp[] = {
+		"HOME=/",
+		"PATH=/sbin:/vendor/bin:/system/sbin:/system/bin:/system/xbin",
+		NULL,
+	};
+	static char *argv[] = {
+		start_path,
+		"unipro_reset",
+		NULL,
+	};
+
+	printk(KERN_ERR "svc_watchdog: calling \"%s %s\" to reset greybus network!\n",
+	       argv[0], argv[1]);
+	call_usermodehelper(start_path, argv, envp, UMH_WAIT_EXEC);
+}
+
+static void do_work(struct work_struct *work)
+{
+	struct gb_svc_watchdog *watchdog;
+	struct gb_svc *svc;
+	int retval;
+
+	watchdog = container_of(work, struct gb_svc_watchdog, work.work);
+	svc = watchdog->svc;
+
+	dev_dbg(&svc->dev, "%s: ping.\n", __func__);
+	retval = gb_svc_ping(svc);
+	if (retval) {
+		/*
+		 * Something went really wrong, let's warn userspace and then
+		 * pull the plug and reset the whole greybus network.
+		 * We need to do this outside of this workqueue as we will be
+		 * tearing down the svc device itself.  So queue up
+		 * yet-another-callback to do that.
+		 */
+		dev_err(&svc->dev,
+			"SVC ping has returned %d, something is wrong!!!\n",
+			retval);
+
+		if (svc->action == GB_SVC_WATCHDOG_BITE_PANIC_KERNEL) {
+			panic("SVC is not responding\n");
+		} else if (svc->action == GB_SVC_WATCHDOG_BITE_RESET_UNIPRO) {
+			dev_err(&svc->dev, "Resetting the greybus network, watch out!!!\n");
+
+			INIT_DELAYED_WORK(&reset_work, greybus_reset);
+			schedule_delayed_work(&reset_work, HZ / 2);
+
+			/*
+			 * Disable ourselves, we don't want to trip again unless
+			 * userspace wants us to.
+			 */
+			watchdog->enabled = false;
+		}
+	}
+
+	/* resubmit our work to happen again, if we are still "alive" */
+	if (watchdog->enabled)
+		schedule_delayed_work(&watchdog->work, SVC_WATCHDOG_PERIOD);
+}
+
+int gb_svc_watchdog_create(struct gb_svc *svc)
+{
+	struct gb_svc_watchdog *watchdog;
+	int retval;
+
+	if (svc->watchdog)
+		return 0;
+
+	watchdog = kmalloc(sizeof(*watchdog), GFP_KERNEL);
+	if (!watchdog)
+		return -ENOMEM;
+
+	watchdog->enabled = false;
+	watchdog->svc = svc;
+	INIT_DELAYED_WORK(&watchdog->work, do_work);
+	svc->watchdog = watchdog;
+
+	watchdog->pm_notifier.notifier_call = svc_watchdog_pm_notifier;
+	retval = register_pm_notifier(&watchdog->pm_notifier);
+	if (retval) {
+		dev_err(&svc->dev, "error registering pm notifier(%d)\n",
+			retval);
+		goto svc_watchdog_create_err;
+	}
+
+	retval = gb_svc_watchdog_enable(svc);
+	if (retval) {
+		dev_err(&svc->dev, "error enabling watchdog (%d)\n", retval);
+		unregister_pm_notifier(&watchdog->pm_notifier);
+		goto svc_watchdog_create_err;
+	}
+	return retval;
+
+svc_watchdog_create_err:
+	svc->watchdog = NULL;
+	kfree(watchdog);
+
+	return retval;
+}
+
+void gb_svc_watchdog_destroy(struct gb_svc *svc)
+{
+	struct gb_svc_watchdog *watchdog = svc->watchdog;
+
+	if (!watchdog)
+		return;
+
+	unregister_pm_notifier(&watchdog->pm_notifier);
+	gb_svc_watchdog_disable(svc);
+	svc->watchdog = NULL;
+	kfree(watchdog);
+}
+
+bool gb_svc_watchdog_enabled(struct gb_svc *svc)
+{
+	if (!svc || !svc->watchdog)
+		return false;
+	return svc->watchdog->enabled;
+}
+
+int gb_svc_watchdog_enable(struct gb_svc *svc)
+{
+	struct gb_svc_watchdog *watchdog;
+
+	if (!svc->watchdog)
+		return -ENODEV;
+
+	watchdog = svc->watchdog;
+	if (watchdog->enabled)
+		return 0;
+
+	watchdog->enabled = true;
+	schedule_delayed_work(&watchdog->work, SVC_WATCHDOG_PERIOD);
+	return 0;
+}
+
+int gb_svc_watchdog_disable(struct gb_svc *svc)
+{
+	struct gb_svc_watchdog *watchdog;
+
+	if (!svc->watchdog)
+		return -ENODEV;
+
+	watchdog = svc->watchdog;
+	if (!watchdog->enabled)
+		return 0;
+
+	watchdog->enabled = false;
+	cancel_delayed_work_sync(&watchdog->work);
+	return 0;
+}