Adding upstream version 4.19.249.upstream/4.19.249

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

1 files changed, 785 insertions, 0 deletions

diff --git a/drivers/hid/intel-ish-hid/ishtp/bus.c b/drivers/hid/intel-ish-hid/ishtp/bus.c
new file mode 100644
index 000000000..f546635e9
--- /dev/null
+++ b/drivers/hid/intel-ish-hid/ishtp/bus.c
@@ -0,0 +1,785 @@
+/*
+ * ISHTP bus driver
+ *
+ * Copyright (c) 2012-2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include "bus.h"
+#include "ishtp-dev.h"
+#include "client.h"
+#include "hbm.h"
+
+static int ishtp_use_dma;
+module_param_named(ishtp_use_dma, ishtp_use_dma, int, 0600);
+MODULE_PARM_DESC(ishtp_use_dma, "Use DMA to send messages");
+
+#define to_ishtp_cl_driver(d) container_of(d, struct ishtp_cl_driver, driver)
+#define to_ishtp_cl_device(d) container_of(d, struct ishtp_cl_device, dev)
+static bool ishtp_device_ready;
+
+/**
+ * ishtp_recv() - process ishtp message
+ * @dev: ishtp device
+ *
+ * If a message with valid header and size is received, then
+ * this function calls appropriate handler. The host or firmware
+ * address is zero, then they are host bus management message,
+ * otherwise they are message fo clients.
+ */
+void ishtp_recv(struct ishtp_device *dev)
+{
+	uint32_t	msg_hdr;
+	struct ishtp_msg_hdr	*ishtp_hdr;
+
+	/* Read ISHTP header dword */
+	msg_hdr = dev->ops->ishtp_read_hdr(dev);
+	if (!msg_hdr)
+		return;
+
+	dev->ops->sync_fw_clock(dev);
+
+	ishtp_hdr = (struct ishtp_msg_hdr *)&msg_hdr;
+	dev->ishtp_msg_hdr = msg_hdr;
+
+	/* Sanity check: ISHTP frag. length in header */
+	if (ishtp_hdr->length > dev->mtu) {
+		dev_err(dev->devc,
+			"ISHTP hdr - bad length: %u; dropped [%08X]\n",
+			(unsigned int)ishtp_hdr->length, msg_hdr);
+		return;
+	}
+
+	/* ISHTP bus message */
+	if (!ishtp_hdr->host_addr && !ishtp_hdr->fw_addr)
+		recv_hbm(dev, ishtp_hdr);
+	/* ISHTP fixed-client message */
+	else if (!ishtp_hdr->host_addr)
+		recv_fixed_cl_msg(dev, ishtp_hdr);
+	else
+		/* ISHTP client message */
+		recv_ishtp_cl_msg(dev, ishtp_hdr);
+}
+EXPORT_SYMBOL(ishtp_recv);
+
+/**
+ * ishtp_send_msg() - Send ishtp message
+ * @dev: ishtp device
+ * @hdr: Message header
+ * @msg: Message contents
+ * @ipc_send_compl: completion callback
+ * @ipc_send_compl_prm: completion callback parameter
+ *
+ * Send a multi fragment message via IPC. After sending the first fragment
+ * the completion callback is called to schedule transmit of next fragment.
+ *
+ * Return: This returns IPC send message status.
+ */
+int ishtp_send_msg(struct ishtp_device *dev, struct ishtp_msg_hdr *hdr,
+		       void *msg, void(*ipc_send_compl)(void *),
+		       void *ipc_send_compl_prm)
+{
+	unsigned char	ipc_msg[IPC_FULL_MSG_SIZE];
+	uint32_t	drbl_val;
+
+	drbl_val = dev->ops->ipc_get_header(dev, hdr->length +
+					    sizeof(struct ishtp_msg_hdr),
+					    1);
+
+	memcpy(ipc_msg, &drbl_val, sizeof(uint32_t));
+	memcpy(ipc_msg + sizeof(uint32_t), hdr, sizeof(uint32_t));
+	memcpy(ipc_msg + 2 * sizeof(uint32_t), msg, hdr->length);
+	return	dev->ops->write(dev, ipc_send_compl, ipc_send_compl_prm,
+				ipc_msg, 2 * sizeof(uint32_t) + hdr->length);
+}
+
+/**
+ * ishtp_write_message() - Send ishtp single fragment message
+ * @dev: ishtp device
+ * @hdr: Message header
+ * @buf: message data
+ *
+ * Send a single fragment message via IPC.  This returns IPC send message
+ * status.
+ *
+ * Return: This returns IPC send message status.
+ */
+int ishtp_write_message(struct ishtp_device *dev, struct ishtp_msg_hdr *hdr,
+			unsigned char *buf)
+{
+	return ishtp_send_msg(dev, hdr, buf, NULL, NULL);
+}
+
+/**
+ * ishtp_fw_cl_by_uuid() - locate index of fw client
+ * @dev: ishtp device
+ * @uuid: uuid of the client to search
+ *
+ * Search firmware client using UUID.
+ *
+ * Return: fw client index or -ENOENT if not found
+ */
+int ishtp_fw_cl_by_uuid(struct ishtp_device *dev, const uuid_le *uuid)
+{
+	int i, res = -ENOENT;
+
+	for (i = 0; i < dev->fw_clients_num; ++i) {
+		if (uuid_le_cmp(*uuid, dev->fw_clients[i].props.protocol_name)
+				== 0) {
+			res = i;
+			break;
+		}
+	}
+	return res;
+}
+EXPORT_SYMBOL(ishtp_fw_cl_by_uuid);
+
+/**
+ * ishtp_fw_cl_by_id() - return index to fw_clients for client_id
+ * @dev: the ishtp device structure
+ * @client_id: fw client id to search
+ *
+ * Search firmware client using client id.
+ *
+ * Return: index on success, -ENOENT on failure.
+ */
+int ishtp_fw_cl_by_id(struct ishtp_device *dev, uint8_t client_id)
+{
+	int i, res = -ENOENT;
+	unsigned long	flags;
+
+	spin_lock_irqsave(&dev->fw_clients_lock, flags);
+	for (i = 0; i < dev->fw_clients_num; i++) {
+		if (dev->fw_clients[i].client_id == client_id) {
+			res = i;
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&dev->fw_clients_lock, flags);
+
+	return res;
+}
+
+/**
+ * ishtp_cl_device_probe() - Bus probe() callback
+ * @dev: the device structure
+ *
+ * This is a bus probe callback and calls the drive probe function.
+ *
+ * Return: Return value from driver probe() call.
+ */
+static int ishtp_cl_device_probe(struct device *dev)
+{
+	struct ishtp_cl_device *device = to_ishtp_cl_device(dev);
+	struct ishtp_cl_driver *driver;
+
+	if (!device)
+		return 0;
+
+	driver = to_ishtp_cl_driver(dev->driver);
+	if (!driver || !driver->probe)
+		return -ENODEV;
+
+	return driver->probe(device);
+}
+
+/**
+ * ishtp_cl_device_remove() - Bus remove() callback
+ * @dev: the device structure
+ *
+ * This is a bus remove callback and calls the drive remove function.
+ * Since the ISH driver model supports only built in, this is
+ * primarily can be called during pci driver init failure.
+ *
+ * Return: Return value from driver remove() call.
+ */
+static int ishtp_cl_device_remove(struct device *dev)
+{
+	struct ishtp_cl_device *device = to_ishtp_cl_device(dev);
+	struct ishtp_cl_driver *driver;
+
+	if (!device || !dev->driver)
+		return 0;
+
+	if (device->event_cb) {
+		device->event_cb = NULL;
+		cancel_work_sync(&device->event_work);
+	}
+
+	driver = to_ishtp_cl_driver(dev->driver);
+	if (!driver->remove) {
+		dev->driver = NULL;
+
+		return 0;
+	}
+
+	return driver->remove(device);
+}
+
+/**
+ * ishtp_cl_device_suspend() - Bus suspend callback
+ * @dev:	device
+ *
+ * Called during device suspend process.
+ *
+ * Return: Return value from driver suspend() call.
+ */
+static int ishtp_cl_device_suspend(struct device *dev)
+{
+	struct ishtp_cl_device *device = to_ishtp_cl_device(dev);
+	struct ishtp_cl_driver *driver;
+	int ret = 0;
+
+	if (!device)
+		return 0;
+
+	driver = to_ishtp_cl_driver(dev->driver);
+	if (driver && driver->driver.pm) {
+		if (driver->driver.pm->suspend)
+			ret = driver->driver.pm->suspend(dev);
+	}
+
+	return ret;
+}
+
+/**
+ * ishtp_cl_device_resume() - Bus resume callback
+ * @dev:	device
+ *
+ * Called during device resume process.
+ *
+ * Return: Return value from driver resume() call.
+ */
+static int ishtp_cl_device_resume(struct device *dev)
+{
+	struct ishtp_cl_device *device = to_ishtp_cl_device(dev);
+	struct ishtp_cl_driver *driver;
+	int ret = 0;
+
+	if (!device)
+		return 0;
+
+	/*
+	 * When ISH needs hard reset, it is done asynchrnously, hence bus
+	 * resume will  be called before full ISH resume
+	 */
+	if (device->ishtp_dev->resume_flag)
+		return 0;
+
+	driver = to_ishtp_cl_driver(dev->driver);
+	if (driver && driver->driver.pm) {
+		if (driver->driver.pm->resume)
+			ret = driver->driver.pm->resume(dev);
+	}
+
+	return ret;
+}
+
+/**
+ * ishtp_cl_device_reset() - Reset callback
+ * @device:	ishtp client device instance
+ *
+ * This is a callback when HW reset is done and the device need
+ * reinit.
+ *
+ * Return: Return value from driver reset() call.
+ */
+static int ishtp_cl_device_reset(struct ishtp_cl_device *device)
+{
+	struct ishtp_cl_driver *driver;
+	int ret = 0;
+
+	device->event_cb = NULL;
+	cancel_work_sync(&device->event_work);
+
+	driver = to_ishtp_cl_driver(device->dev.driver);
+	if (driver && driver->reset)
+		ret = driver->reset(device);
+
+	return ret;
+}
+
+static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
+	char *buf)
+{
+	int len;
+
+	len = snprintf(buf, PAGE_SIZE, "ishtp:%s\n", dev_name(dev));
+	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
+}
+static DEVICE_ATTR_RO(modalias);
+
+static struct attribute *ishtp_cl_dev_attrs[] = {
+	&dev_attr_modalias.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(ishtp_cl_dev);
+
+static int ishtp_cl_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	if (add_uevent_var(env, "MODALIAS=ishtp:%s", dev_name(dev)))
+		return -ENOMEM;
+	return 0;
+}
+
+static const struct dev_pm_ops ishtp_cl_bus_dev_pm_ops = {
+	/* Suspend callbacks */
+	.suspend = ishtp_cl_device_suspend,
+	.resume = ishtp_cl_device_resume,
+	/* Hibernate callbacks */
+	.freeze = ishtp_cl_device_suspend,
+	.thaw = ishtp_cl_device_resume,
+	.restore = ishtp_cl_device_resume,
+};
+
+static struct bus_type ishtp_cl_bus_type = {
+	.name		= "ishtp",
+	.dev_groups	= ishtp_cl_dev_groups,
+	.probe		= ishtp_cl_device_probe,
+	.remove		= ishtp_cl_device_remove,
+	.pm		= &ishtp_cl_bus_dev_pm_ops,
+	.uevent		= ishtp_cl_uevent,
+};
+
+static void ishtp_cl_dev_release(struct device *dev)
+{
+	kfree(to_ishtp_cl_device(dev));
+}
+
+static const struct device_type ishtp_cl_device_type = {
+	.release	= ishtp_cl_dev_release,
+};
+
+/**
+ * ishtp_bus_add_device() - Function to create device on bus
+ * @dev:	ishtp device
+ * @uuid:	uuid of the client
+ * @name:	Name of the client
+ *
+ * Allocate ISHTP bus client device, attach it to uuid
+ * and register with ISHTP bus.
+ *
+ * Return: ishtp_cl_device pointer or NULL on failure
+ */
+static struct ishtp_cl_device *ishtp_bus_add_device(struct ishtp_device *dev,
+						    uuid_le uuid, char *name)
+{
+	struct ishtp_cl_device *device;
+	int status;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->device_list_lock, flags);
+	list_for_each_entry(device, &dev->device_list, device_link) {
+		if (!strcmp(name, dev_name(&device->dev))) {
+			device->fw_client = &dev->fw_clients[
+				dev->fw_client_presentation_num - 1];
+			spin_unlock_irqrestore(&dev->device_list_lock, flags);
+			ishtp_cl_device_reset(device);
+			return device;
+		}
+	}
+	spin_unlock_irqrestore(&dev->device_list_lock, flags);
+
+	device = kzalloc(sizeof(struct ishtp_cl_device), GFP_KERNEL);
+	if (!device)
+		return NULL;
+
+	device->dev.parent = dev->devc;
+	device->dev.bus = &ishtp_cl_bus_type;
+	device->dev.type = &ishtp_cl_device_type;
+	device->ishtp_dev = dev;
+
+	device->fw_client =
+		&dev->fw_clients[dev->fw_client_presentation_num - 1];
+
+	dev_set_name(&device->dev, "%s", name);
+
+	spin_lock_irqsave(&dev->device_list_lock, flags);
+	list_add_tail(&device->device_link, &dev->device_list);
+	spin_unlock_irqrestore(&dev->device_list_lock, flags);
+
+	status = device_register(&device->dev);
+	if (status) {
+		spin_lock_irqsave(&dev->device_list_lock, flags);
+		list_del(&device->device_link);
+		spin_unlock_irqrestore(&dev->device_list_lock, flags);
+		dev_err(dev->devc, "Failed to register ISHTP client device\n");
+		put_device(&device->dev);
+		return NULL;
+	}
+
+	ishtp_device_ready = true;
+
+	return device;
+}
+
+/**
+ * ishtp_bus_remove_device() - Function to relase device on bus
+ * @device:	client device instance
+ *
+ * This is a counterpart of ishtp_bus_add_device.
+ * Device is unregistered.
+ * the device structure is freed in 'ishtp_cl_dev_release' function
+ * Called only during error in pci driver init path.
+ */
+static void ishtp_bus_remove_device(struct ishtp_cl_device *device)
+{
+	device_unregister(&device->dev);
+}
+
+/**
+ * __ishtp_cl_driver_register() - Client driver register
+ * @driver:	the client driver instance
+ * @owner:	Owner of this driver module
+ *
+ * Once a client driver is probed, it created a client
+ * instance and registers with the bus.
+ *
+ * Return: Return value of driver_register or -ENODEV if not ready
+ */
+int __ishtp_cl_driver_register(struct ishtp_cl_driver *driver,
+			       struct module *owner)
+{
+	int err;
+
+	if (!ishtp_device_ready)
+		return -ENODEV;
+
+	driver->driver.name = driver->name;
+	driver->driver.owner = owner;
+	driver->driver.bus = &ishtp_cl_bus_type;
+
+	err = driver_register(&driver->driver);
+	if (err)
+		return err;
+
+	return 0;
+}
+EXPORT_SYMBOL(__ishtp_cl_driver_register);
+
+/**
+ * ishtp_cl_driver_unregister() - Client driver unregister
+ * @driver:	the client driver instance
+ *
+ * Unregister client during device removal process.
+ */
+void ishtp_cl_driver_unregister(struct ishtp_cl_driver *driver)
+{
+	driver_unregister(&driver->driver);
+}
+EXPORT_SYMBOL(ishtp_cl_driver_unregister);
+
+/**
+ * ishtp_bus_event_work() - event work function
+ * @work:	work struct pointer
+ *
+ * Once an event is received for a client this work
+ * function is called. If the device has registered a
+ * callback then the callback is called.
+ */
+static void ishtp_bus_event_work(struct work_struct *work)
+{
+	struct ishtp_cl_device *device;
+
+	device = container_of(work, struct ishtp_cl_device, event_work);
+
+	if (device->event_cb)
+		device->event_cb(device);
+}
+
+/**
+ * ishtp_cl_bus_rx_event() - schedule event work
+ * @device:	client device instance
+ *
+ * Once an event is received for a client this schedules
+ * a work function to process.
+ */
+void ishtp_cl_bus_rx_event(struct ishtp_cl_device *device)
+{
+	if (!device || !device->event_cb)
+		return;
+
+	if (device->event_cb)
+		schedule_work(&device->event_work);
+}
+
+/**
+ * ishtp_register_event_cb() - Register callback
+ * @device:	client device instance
+ * @event_cb:	Event processor for an client
+ *
+ * Register a callback for events, called from client driver
+ *
+ * Return: Return 0 or -EALREADY if already registered
+ */
+int ishtp_register_event_cb(struct ishtp_cl_device *device,
+	void (*event_cb)(struct ishtp_cl_device *))
+{
+	if (device->event_cb)
+		return -EALREADY;
+
+	device->event_cb = event_cb;
+	INIT_WORK(&device->event_work, ishtp_bus_event_work);
+
+	return 0;
+}
+EXPORT_SYMBOL(ishtp_register_event_cb);
+
+/**
+ * ishtp_get_device() - update usage count for the device
+ * @cl_device:	client device instance
+ *
+ * Increment the usage count. The device can't be deleted
+ */
+void ishtp_get_device(struct ishtp_cl_device *cl_device)
+{
+	cl_device->reference_count++;
+}
+EXPORT_SYMBOL(ishtp_get_device);
+
+/**
+ * ishtp_put_device() - decrement usage count for the device
+ * @cl_device:	client device instance
+ *
+ * Decrement the usage count. The device can be deleted is count = 0
+ */
+void ishtp_put_device(struct ishtp_cl_device *cl_device)
+{
+	cl_device->reference_count--;
+}
+EXPORT_SYMBOL(ishtp_put_device);
+
+/**
+ * ishtp_bus_new_client() - Create a new client
+ * @dev:	ISHTP device instance
+ *
+ * Once bus protocol enumerates a client, this is called
+ * to add a device for the client.
+ *
+ * Return: 0 on success or error code on failure
+ */
+int ishtp_bus_new_client(struct ishtp_device *dev)
+{
+	int	i;
+	char	*dev_name;
+	struct ishtp_cl_device	*cl_device;
+	uuid_le	device_uuid;
+
+	/*
+	 * For all reported clients, create an unconnected client and add its
+	 * device to ISHTP bus.
+	 * If appropriate driver has loaded, this will trigger its probe().
+	 * Otherwise, probe() will be called when driver is loaded
+	 */
+	i = dev->fw_client_presentation_num - 1;
+	device_uuid = dev->fw_clients[i].props.protocol_name;
+	dev_name = kasprintf(GFP_KERNEL, "{%pUL}", device_uuid.b);
+	if (!dev_name)
+		return	-ENOMEM;
+
+	cl_device = ishtp_bus_add_device(dev, device_uuid, dev_name);
+	if (!cl_device) {
+		kfree(dev_name);
+		return	-ENOENT;
+	}
+
+	kfree(dev_name);
+
+	return	0;
+}
+
+/**
+ * ishtp_cl_device_bind() - bind a device
+ * @cl:		ishtp client device
+ *
+ * Binds connected ishtp_cl to ISHTP bus device
+ *
+ * Return: 0 on success or fault code
+ */
+int ishtp_cl_device_bind(struct ishtp_cl *cl)
+{
+	struct ishtp_cl_device	*cl_device;
+	unsigned long flags;
+	int	rv;
+
+	if (!cl->fw_client_id || cl->state != ISHTP_CL_CONNECTED)
+		return	-EFAULT;
+
+	rv = -ENOENT;
+	spin_lock_irqsave(&cl->dev->device_list_lock, flags);
+	list_for_each_entry(cl_device, &cl->dev->device_list,
+			device_link) {
+		if (cl_device->fw_client &&
+		    cl_device->fw_client->client_id == cl->fw_client_id) {
+			cl->device = cl_device;
+			rv = 0;
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&cl->dev->device_list_lock, flags);
+	return	rv;
+}
+
+/**
+ * ishtp_bus_remove_all_clients() - Remove all clients
+ * @ishtp_dev:		ishtp device
+ * @warm_reset:		Reset due to FW reset dure to errors or S3 suspend
+ *
+ * This is part of reset/remove flow. This function the main processing
+ * only targets error processing, if the FW has forced reset or
+ * error to remove connected clients. When warm reset the client devices are
+ * not removed.
+ */
+void ishtp_bus_remove_all_clients(struct ishtp_device *ishtp_dev,
+				  bool warm_reset)
+{
+	struct ishtp_cl_device	*cl_device, *n;
+	struct ishtp_cl	*cl;
+	unsigned long	flags;
+
+	spin_lock_irqsave(&ishtp_dev->cl_list_lock, flags);
+	list_for_each_entry(cl, &ishtp_dev->cl_list, link) {
+		cl->state = ISHTP_CL_DISCONNECTED;
+
+		/*
+		 * Wake any pending process. The waiter would check dev->state
+		 * and determine that it's not enabled already,
+		 * and will return error to its caller
+		 */
+		wake_up_interruptible(&cl->wait_ctrl_res);
+
+		/* Disband any pending read/write requests and free rb */
+		ishtp_cl_flush_queues(cl);
+
+		/* Remove all free and in_process rings, both Rx and Tx */
+		ishtp_cl_free_rx_ring(cl);
+		ishtp_cl_free_tx_ring(cl);
+
+		/*
+		 * Free client and ISHTP bus client device structures
+		 * don't free host client because it is part of the OS fd
+		 * structure
+		 */
+	}
+	spin_unlock_irqrestore(&ishtp_dev->cl_list_lock, flags);
+
+	/* Release DMA buffers for client messages */
+	ishtp_cl_free_dma_buf(ishtp_dev);
+
+	/* remove bus clients */
+	spin_lock_irqsave(&ishtp_dev->device_list_lock, flags);
+	list_for_each_entry_safe(cl_device, n, &ishtp_dev->device_list,
+				 device_link) {
+		cl_device->fw_client = NULL;
+		if (warm_reset && cl_device->reference_count)
+			continue;
+
+		list_del(&cl_device->device_link);
+		spin_unlock_irqrestore(&ishtp_dev->device_list_lock, flags);
+		ishtp_bus_remove_device(cl_device);
+		spin_lock_irqsave(&ishtp_dev->device_list_lock, flags);
+	}
+	spin_unlock_irqrestore(&ishtp_dev->device_list_lock, flags);
+
+	/* Free all client structures */
+	spin_lock_irqsave(&ishtp_dev->fw_clients_lock, flags);
+	kfree(ishtp_dev->fw_clients);
+	ishtp_dev->fw_clients = NULL;
+	ishtp_dev->fw_clients_num = 0;
+	ishtp_dev->fw_client_presentation_num = 0;
+	ishtp_dev->fw_client_index = 0;
+	bitmap_zero(ishtp_dev->fw_clients_map, ISHTP_CLIENTS_MAX);
+	spin_unlock_irqrestore(&ishtp_dev->fw_clients_lock, flags);
+}
+EXPORT_SYMBOL(ishtp_bus_remove_all_clients);
+
+/**
+ * ishtp_reset_handler() - IPC reset handler
+ * @dev:	ishtp device
+ *
+ * ISHTP Handler for IPC_RESET notification
+ */
+void ishtp_reset_handler(struct ishtp_device *dev)
+{
+	unsigned long	flags;
+
+	/* Handle FW-initiated reset */
+	dev->dev_state = ISHTP_DEV_RESETTING;
+
+	/* Clear BH processing queue - no further HBMs */
+	spin_lock_irqsave(&dev->rd_msg_spinlock, flags);
+	dev->rd_msg_fifo_head = dev->rd_msg_fifo_tail = 0;
+	spin_unlock_irqrestore(&dev->rd_msg_spinlock, flags);
+
+	/* Handle ISH FW reset against upper layers */
+	ishtp_bus_remove_all_clients(dev, true);
+}
+EXPORT_SYMBOL(ishtp_reset_handler);
+
+/**
+ * ishtp_reset_compl_handler() - Reset completion handler
+ * @dev:	ishtp device
+ *
+ * ISHTP handler for IPC_RESET sequence completion to start
+ * host message bus start protocol sequence.
+ */
+void ishtp_reset_compl_handler(struct ishtp_device *dev)
+{
+	dev->dev_state = ISHTP_DEV_INIT_CLIENTS;
+	dev->hbm_state = ISHTP_HBM_START;
+	ishtp_hbm_start_req(dev);
+}
+EXPORT_SYMBOL(ishtp_reset_compl_handler);
+
+/**
+ * ishtp_use_dma_transfer() - Function to use DMA
+ *
+ * This interface is used to enable usage of DMA
+ *
+ * Return non zero if DMA can be enabled
+ */
+int ishtp_use_dma_transfer(void)
+{
+	return ishtp_use_dma;
+}
+
+/**
+ * ishtp_bus_register() - Function to register bus
+ *
+ * This register ishtp bus
+ *
+ * Return: Return output of bus_register
+ */
+static int  __init ishtp_bus_register(void)
+{
+	return bus_register(&ishtp_cl_bus_type);
+}
+
+/**
+ * ishtp_bus_unregister() - Function to unregister bus
+ *
+ * This unregister ishtp bus
+ */
+static void __exit ishtp_bus_unregister(void)
+{
+	bus_unregister(&ishtp_cl_bus_type);
+}
+
+module_init(ishtp_bus_register);
+module_exit(ishtp_bus_unregister);
+
+MODULE_LICENSE("GPL");