Merging upstream version 6.8.9.

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

6 files changed, 221 insertions, 164 deletions

diff --git a/drivers/hid/intel-ish-hid/ipc/ipc.c b/drivers/hid/intel-ish-hid/ipc/ipc.c
index a49c6affd7..dd5fc60874 100644
--- a/drivers/hid/intel-ish-hid/ipc/ipc.c
+++ b/drivers/hid/intel-ish-hid/ipc/ipc.c
@@ -948,6 +948,7 @@ struct ishtp_device *ish_dev_init(struct pci_dev *pdev)
 	if (!dev)
 		return NULL;
 
+	dev->devc = &pdev->dev;
 	ishtp_device_init(dev);
 
 	init_waitqueue_head(&dev->wait_hw_ready);
@@ -983,7 +984,6 @@ struct ishtp_device *ish_dev_init(struct pci_dev *pdev)
 	}
 
 	dev->ops = &ish_hw_ops;
-	dev->devc = &pdev->dev;
 	dev->mtu = IPC_PAYLOAD_SIZE - sizeof(struct ishtp_msg_hdr);
 	return dev;
 }
diff --git a/drivers/hid/intel-ish-hid/ipc/pci-ish.c b/drivers/hid/intel-ish-hid/ipc/pci-ish.c
index 710fda5f19..65e7eeb2fa 100644
--- a/drivers/hid/intel-ish-hid/ipc/pci-ish.c
+++ b/drivers/hid/intel-ish-hid/ipc/pci-ish.c
@@ -119,50 +119,6 @@ static inline bool ish_should_leave_d0i3(struct pci_dev *pdev)
 	return !pm_resume_via_firmware() || pdev->device == CHV_DEVICE_ID;
 }
 
-static int enable_gpe(struct device *dev)
-{
-#ifdef CONFIG_ACPI
-	acpi_status acpi_sts;
-	struct acpi_device *adev;
-	struct acpi_device_wakeup *wakeup;
-
-	adev = ACPI_COMPANION(dev);
-	if (!adev) {
-		dev_err(dev, "get acpi handle failed\n");
-		return -ENODEV;
-	}
-	wakeup = &adev->wakeup;
-
-	/*
-	 * Call acpi_disable_gpe(), so that reference count
-	 * gpe_event_info->runtime_count doesn't overflow.
-	 * When gpe_event_info->runtime_count = 0, the call
-	 * to acpi_disable_gpe() simply return.
-	 */
-	acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
-
-	acpi_sts = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number);
-	if (ACPI_FAILURE(acpi_sts)) {
-		dev_err(dev, "enable ose_gpe failed\n");
-		return -EIO;
-	}
-
-	return 0;
-#else
-	return -ENODEV;
-#endif
-}
-
-static void enable_pme_wake(struct pci_dev *pdev)
-{
-	if ((pci_pme_capable(pdev, PCI_D0) ||
-	     pci_pme_capable(pdev, PCI_D3hot) ||
-	     pci_pme_capable(pdev, PCI_D3cold)) && !enable_gpe(&pdev->dev)) {
-		pci_pme_active(pdev, true);
-		dev_dbg(&pdev->dev, "ish ipc driver pme wake enabled\n");
-	}
-}
-
 /**
  * ish_probe() - PCI driver probe callback
  * @pdev:	pci device
@@ -233,7 +189,7 @@ static int ish_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	/* Enable PME for EHL */
 	if (pdev->device == EHL_Ax_DEVICE_ID)
-		enable_pme_wake(pdev);
+		device_init_wakeup(dev, true);
 
 	ret = ish_init(ishtp);
 	if (ret)
@@ -256,6 +212,19 @@ static void ish_remove(struct pci_dev *pdev)
 	ish_device_disable(ishtp_dev);
 }
 
+
+/**
+ * ish_shutdown() - PCI driver shutdown callback
+ * @pdev:	pci device
+ *
+ * This function sets up wakeup for S5
+ */
+static void ish_shutdown(struct pci_dev *pdev)
+{
+	if (pdev->device == EHL_Ax_DEVICE_ID)
+		pci_prepare_to_sleep(pdev);
+}
+
 static struct device __maybe_unused *ish_resume_device;
 
 /* 50ms to get resume response */
@@ -378,13 +347,6 @@ static int __maybe_unused ish_resume(struct device *device)
 	struct pci_dev *pdev = to_pci_dev(device);
 	struct ishtp_device *dev = pci_get_drvdata(pdev);
 
-	/* add this to finish power flow for EHL */
-	if (dev->pdev->device == EHL_Ax_DEVICE_ID) {
-		pci_set_power_state(pdev, PCI_D0);
-		enable_pme_wake(pdev);
-		dev_dbg(dev->devc, "set power state to D0 for ehl\n");
-	}
-
 	ish_resume_device = device;
 	dev->resume_flag = 1;
 
@@ -400,6 +362,7 @@ static struct pci_driver ish_driver = {
 	.id_table = ish_pci_tbl,
 	.probe = ish_probe,
 	.remove = ish_remove,
+	.shutdown = ish_shutdown,
 	.driver.pm = &ish_pm_ops,
 };
 
diff --git a/drivers/hid/intel-ish-hid/ishtp-fw-loader.c b/drivers/hid/intel-ish-hid/ishtp-fw-loader.c
index 16aa030af8..e157863a8b 100644
--- a/drivers/hid/intel-ish-hid/ishtp-fw-loader.c
+++ b/drivers/hid/intel-ish-hid/ishtp-fw-loader.c
@@ -840,43 +840,22 @@ static void load_fw_from_host_handler(struct work_struct *work)
  *
  * Return: 0 for success, negative error code for failure
  */
-static int loader_init(struct ishtp_cl *loader_ishtp_cl, int reset)
+static int loader_init(struct ishtp_cl *loader_ishtp_cl, bool reset)
 {
 	int rv;
-	struct ishtp_fw_client *fw_client;
 	struct ishtp_cl_data *client_data =
 		ishtp_get_client_data(loader_ishtp_cl);
 
 	dev_dbg(cl_data_to_dev(client_data), "reset flag: %d\n", reset);
 
-	rv = ishtp_cl_link(loader_ishtp_cl);
-	if (rv < 0) {
-		dev_err(cl_data_to_dev(client_data), "ishtp_cl_link failed\n");
-		return rv;
-	}
-
-	/* Connect to firmware client */
-	ishtp_set_tx_ring_size(loader_ishtp_cl, LOADER_CL_TX_RING_SIZE);
-	ishtp_set_rx_ring_size(loader_ishtp_cl, LOADER_CL_RX_RING_SIZE);
-
-	fw_client =
-		ishtp_fw_cl_get_client(ishtp_get_ishtp_device(loader_ishtp_cl),
-				       &loader_ishtp_id_table[0].guid);
-	if (!fw_client) {
-		dev_err(cl_data_to_dev(client_data),
-			"ISH client uuid not found\n");
-		rv = -ENOENT;
-		goto err_cl_unlink;
-	}
-
-	ishtp_cl_set_fw_client_id(loader_ishtp_cl,
-				  ishtp_get_fw_client_id(fw_client));
-	ishtp_set_connection_state(loader_ishtp_cl, ISHTP_CL_CONNECTING);
-
-	rv = ishtp_cl_connect(loader_ishtp_cl);
+	rv = ishtp_cl_establish_connection(loader_ishtp_cl,
+					   &loader_ishtp_id_table[0].guid,
+					   LOADER_CL_TX_RING_SIZE,
+					   LOADER_CL_RX_RING_SIZE,
+					   reset);
 	if (rv < 0) {
 		dev_err(cl_data_to_dev(client_data), "Client connect fail\n");
-		goto err_cl_unlink;
+		goto err_cl_disconnect;
 	}
 
 	dev_dbg(cl_data_to_dev(client_data), "Client connected\n");
@@ -885,17 +864,14 @@ static int loader_init(struct ishtp_cl *loader_ishtp_cl, int reset)
 
 	return 0;
 
-err_cl_unlink:
-	ishtp_cl_unlink(loader_ishtp_cl);
+err_cl_disconnect:
+	ishtp_cl_destroy_connection(loader_ishtp_cl, reset);
 	return rv;
 }
 
 static void loader_deinit(struct ishtp_cl *loader_ishtp_cl)
 {
-	ishtp_set_connection_state(loader_ishtp_cl, ISHTP_CL_DISCONNECTING);
-	ishtp_cl_disconnect(loader_ishtp_cl);
-	ishtp_cl_unlink(loader_ishtp_cl);
-	ishtp_cl_flush_queues(loader_ishtp_cl);
+	ishtp_cl_destroy_connection(loader_ishtp_cl, false);
 
 	/* Disband and free all Tx and Rx client-level rings */
 	ishtp_cl_free(loader_ishtp_cl);
@@ -914,19 +890,7 @@ static void reset_handler(struct work_struct *work)
 	loader_ishtp_cl = client_data->loader_ishtp_cl;
 	cl_device = client_data->cl_device;
 
-	/* Unlink, flush queues & start again */
-	ishtp_cl_unlink(loader_ishtp_cl);
-	ishtp_cl_flush_queues(loader_ishtp_cl);
-	ishtp_cl_free(loader_ishtp_cl);
-
-	loader_ishtp_cl = ishtp_cl_allocate(cl_device);
-	if (!loader_ishtp_cl)
-		return;
-
-	ishtp_set_drvdata(cl_device, loader_ishtp_cl);
-	ishtp_set_client_data(loader_ishtp_cl, client_data);
-	client_data->loader_ishtp_cl = loader_ishtp_cl;
-	client_data->cl_device = cl_device;
+	ishtp_cl_destroy_connection(loader_ishtp_cl, true);
 
 	rv = loader_init(loader_ishtp_cl, 1);
 	if (rv < 0) {
@@ -974,7 +938,7 @@ static int loader_ishtp_cl_probe(struct ishtp_cl_device *cl_device)
 	INIT_WORK(&client_data->work_fw_load,
 		  load_fw_from_host_handler);
 
-	rv = loader_init(loader_ishtp_cl, 0);
+	rv = loader_init(loader_ishtp_cl, false);
 	if (rv < 0) {
 		ishtp_cl_free(loader_ishtp_cl);
 		return rv;
diff --git a/drivers/hid/intel-ish-hid/ishtp-hid-client.c b/drivers/hid/intel-ish-hid/ishtp-hid-client.c
index e3d70c5460..fbd4f8ea19 100644
--- a/drivers/hid/intel-ish-hid/ishtp-hid-client.c
+++ b/drivers/hid/intel-ish-hid/ishtp-hid-client.c
@@ -639,47 +639,26 @@ static int ishtp_get_report_descriptor(struct ishtp_cl *hid_ishtp_cl,
  *
  * Return: 0 on success, non zero on error
  */
-static int hid_ishtp_cl_init(struct ishtp_cl *hid_ishtp_cl, int reset)
+static int hid_ishtp_cl_init(struct ishtp_cl *hid_ishtp_cl, bool reset)
 {
-	struct ishtp_device *dev;
 	struct ishtp_cl_data *client_data = ishtp_get_client_data(hid_ishtp_cl);
-	struct ishtp_fw_client *fw_client;
 	int i;
 	int rv;
 
 	dev_dbg(cl_data_to_dev(client_data), "%s\n", __func__);
 	hid_ishtp_trace(client_data,  "%s reset flag: %d\n", __func__, reset);
 
-	rv = ishtp_cl_link(hid_ishtp_cl);
-	if (rv) {
-		dev_err(cl_data_to_dev(client_data),
-			"ishtp_cl_link failed\n");
-		return	-ENOMEM;
-	}
-
 	client_data->init_done = 0;
 
-	dev = ishtp_get_ishtp_device(hid_ishtp_cl);
-
-	/* Connect to FW client */
-	ishtp_set_tx_ring_size(hid_ishtp_cl, HID_CL_TX_RING_SIZE);
-	ishtp_set_rx_ring_size(hid_ishtp_cl, HID_CL_RX_RING_SIZE);
-
-	fw_client = ishtp_fw_cl_get_client(dev, &hid_ishtp_id_table[0].guid);
-	if (!fw_client) {
-		dev_err(cl_data_to_dev(client_data),
-			"ish client uuid not found\n");
-		return -ENOENT;
-	}
-	ishtp_cl_set_fw_client_id(hid_ishtp_cl,
-				  ishtp_get_fw_client_id(fw_client));
-	ishtp_set_connection_state(hid_ishtp_cl, ISHTP_CL_CONNECTING);
-
-	rv = ishtp_cl_connect(hid_ishtp_cl);
+	rv = ishtp_cl_establish_connection(hid_ishtp_cl,
+					   &hid_ishtp_id_table[0].guid,
+					   HID_CL_TX_RING_SIZE,
+					   HID_CL_RX_RING_SIZE,
+					   reset);
 	if (rv) {
 		dev_err(cl_data_to_dev(client_data),
 			"client connect fail\n");
-		goto err_cl_unlink;
+		goto err_cl_disconnect;
 	}
 
 	hid_ishtp_trace(client_data,  "%s client connected\n", __func__);
@@ -723,10 +702,7 @@ static int hid_ishtp_cl_init(struct ishtp_cl *hid_ishtp_cl, int reset)
 	return 0;
 
 err_cl_disconnect:
-	ishtp_set_connection_state(hid_ishtp_cl, ISHTP_CL_DISCONNECTING);
-	ishtp_cl_disconnect(hid_ishtp_cl);
-err_cl_unlink:
-	ishtp_cl_unlink(hid_ishtp_cl);
+	ishtp_cl_destroy_connection(hid_ishtp_cl, reset);
 	return rv;
 }
 
@@ -738,8 +714,7 @@ err_cl_unlink:
  */
 static void hid_ishtp_cl_deinit(struct ishtp_cl *hid_ishtp_cl)
 {
-	ishtp_cl_unlink(hid_ishtp_cl);
-	ishtp_cl_flush_queues(hid_ishtp_cl);
+	ishtp_cl_destroy_connection(hid_ishtp_cl, false);
 
 	/* disband and free all Tx and Rx client-level rings */
 	ishtp_cl_free(hid_ishtp_cl);
@@ -749,33 +724,23 @@ static void hid_ishtp_cl_reset_handler(struct work_struct *work)
 {
 	struct ishtp_cl_data *client_data;
 	struct ishtp_cl *hid_ishtp_cl;
-	struct ishtp_cl_device *cl_device;
 	int retry;
 	int rv;
 
 	client_data = container_of(work, struct ishtp_cl_data, work);
 
 	hid_ishtp_cl = client_data->hid_ishtp_cl;
-	cl_device = client_data->cl_device;
 
 	hid_ishtp_trace(client_data, "%s hid_ishtp_cl %p\n", __func__,
 			hid_ishtp_cl);
 	dev_dbg(ishtp_device(client_data->cl_device), "%s\n", __func__);
 
-	hid_ishtp_cl_deinit(hid_ishtp_cl);
-
-	hid_ishtp_cl = ishtp_cl_allocate(cl_device);
-	if (!hid_ishtp_cl)
-		return;
-
-	ishtp_set_drvdata(cl_device, hid_ishtp_cl);
-	ishtp_set_client_data(hid_ishtp_cl, client_data);
-	client_data->hid_ishtp_cl = hid_ishtp_cl;
+	ishtp_cl_destroy_connection(hid_ishtp_cl, true);
 
 	client_data->num_hid_devices = 0;
 
 	for (retry = 0; retry < 3; ++retry) {
-		rv = hid_ishtp_cl_init(hid_ishtp_cl, 1);
+		rv = hid_ishtp_cl_init(hid_ishtp_cl, true);
 		if (!rv)
 			break;
 		dev_err(cl_data_to_dev(client_data), "Retry reset init\n");
@@ -841,7 +806,7 @@ static int hid_ishtp_cl_probe(struct ishtp_cl_device *cl_device)
 
 	ishtp_hid_print_trace = ishtp_trace_callback(cl_device);
 
-	rv = hid_ishtp_cl_init(hid_ishtp_cl, 0);
+	rv = hid_ishtp_cl_init(hid_ishtp_cl, false);
 	if (rv) {
 		ishtp_cl_free(hid_ishtp_cl);
 		return rv;
@@ -868,11 +833,9 @@ static void hid_ishtp_cl_remove(struct ishtp_cl_device *cl_device)
 			hid_ishtp_cl);
 
 	dev_dbg(ishtp_device(cl_device), "%s\n", __func__);
-	ishtp_set_connection_state(hid_ishtp_cl, ISHTP_CL_DISCONNECTING);
-	ishtp_cl_disconnect(hid_ishtp_cl);
+	hid_ishtp_cl_deinit(hid_ishtp_cl);
 	ishtp_put_device(cl_device);
 	ishtp_hid_remove(client_data);
-	hid_ishtp_cl_deinit(hid_ishtp_cl);
 
 	hid_ishtp_cl = NULL;
 
diff --git a/drivers/hid/intel-ish-hid/ishtp/bus.c b/drivers/hid/intel-ish-hid/ishtp/bus.c
index 7fc738a223..03d5601ce8 100644
--- a/drivers/hid/intel-ish-hid/ishtp/bus.c
+++ b/drivers/hid/intel-ish-hid/ishtp/bus.c
@@ -378,7 +378,7 @@ static const struct dev_pm_ops ishtp_cl_bus_dev_pm_ops = {
 	.restore = ishtp_cl_device_resume,
 };
 
-static struct bus_type ishtp_cl_bus_type = {
+static const struct bus_type ishtp_cl_bus_type = {
 	.name		= "ishtp",
 	.dev_groups	= ishtp_cl_dev_groups,
 	.probe		= ishtp_cl_device_probe,
@@ -722,6 +722,8 @@ void ishtp_bus_remove_all_clients(struct ishtp_device *ishtp_dev,
 	spin_lock_irqsave(&ishtp_dev->cl_list_lock, flags);
 	list_for_each_entry(cl, &ishtp_dev->cl_list, link) {
 		cl->state = ISHTP_CL_DISCONNECTED;
+		if (warm_reset && cl->device->reference_count)
+			continue;
 
 		/*
 		 * Wake any pending process. The waiter would check dev->state
diff --git a/drivers/hid/intel-ish-hid/ishtp/client.c b/drivers/hid/intel-ish-hid/ishtp/client.c
index 2d92fc129c..8a7f2f6a4f 100644
--- a/drivers/hid/intel-ish-hid/ishtp/client.c
+++ b/drivers/hid/intel-ish-hid/ishtp/client.c
@@ -49,7 +49,9 @@ static void ishtp_read_list_flush(struct ishtp_cl *cl)
 	list_for_each_entry_safe(rb, next, &cl->dev->read_list.list, list)
 		if (rb->cl && ishtp_cl_cmp_id(cl, rb->cl)) {
 			list_del(&rb->list);
-			ishtp_io_rb_free(rb);
+			spin_lock(&cl->free_list_spinlock);
+			list_add_tail(&rb->list, &cl->free_rb_list.list);
+			spin_unlock(&cl->free_list_spinlock);
 		}
 	spin_unlock_irqrestore(&cl->dev->read_list_spinlock, flags);
 }
@@ -339,16 +341,17 @@ static bool ishtp_cl_is_other_connecting(struct ishtp_cl *cl)
 }
 
 /**
- * ishtp_cl_connect() - Send connect request to firmware
+ * ishtp_cl_connect_to_fw() - Send connect request to firmware
  * @cl: client device instance
  *
- * Send a connect request for a client to firmware. If successful it will
- * RX and TX ring buffers
+ * Send a connect request to the firmware and wait for firmware response.
+ * If there is successful connection response from the firmware, change
+ * client state to ISHTP_CL_CONNECTED, and bind client to related
+ * firmware client_id.
  *
- * Return: 0 if successful connect response from the firmware and able
- * to bind and allocate ring buffers or error code on failure
+ * Return: 0 for success and error code on failure
  */
-int ishtp_cl_connect(struct ishtp_cl *cl)
+static int ishtp_cl_connect_to_fw(struct ishtp_cl *cl)
 {
 	struct ishtp_device *dev;
 	int rets;
@@ -358,8 +361,6 @@ int ishtp_cl_connect(struct ishtp_cl *cl)
 
 	dev = cl->dev;
 
-	dev->print_log(dev, "%s() current_state = %d\n", __func__, cl->state);
-
 	if (ishtp_cl_is_other_connecting(cl)) {
 		dev->print_log(dev, "%s() Busy\n", __func__);
 		return	-EBUSY;
@@ -405,6 +406,38 @@ int ishtp_cl_connect(struct ishtp_cl *cl)
 		return rets;
 	}
 
+	return rets;
+}
+
+/**
+ * ishtp_cl_connect() - Build connection with firmware
+ * @cl: client device instance
+ *
+ * Call ishtp_cl_connect_to_fw() to connect and bind to firmware. If successful,
+ * allocate RX and TX ring buffers, and start flow control with firmware to
+ * start communication.
+ *
+ * Return: 0 if there is successful connection to the firmware, allocate
+ * ring buffers.
+ */
+int ishtp_cl_connect(struct ishtp_cl *cl)
+{
+	struct ishtp_device *dev;
+	int rets;
+
+	if (!cl || !cl->dev)
+		return -ENODEV;
+
+	dev = cl->dev;
+
+	dev->print_log(dev, "%s() current_state = %d\n", __func__, cl->state);
+
+	rets = ishtp_cl_connect_to_fw(cl);
+	if (rets) {
+		dev->print_log(dev, "%s() Connect to fw failed\n", __func__);
+		return rets;
+	}
+
 	rets = ishtp_cl_alloc_rx_ring(cl);
 	if (rets) {
 		dev->print_log(dev, "%s() Alloc RX ring failed\n", __func__);
@@ -422,16 +455,148 @@ int ishtp_cl_connect(struct ishtp_cl *cl)
 		return rets;
 	}
 
-	/* Upon successful connection and allocation, emit flow-control */
+	/*
+	 * Upon successful connection and allocation, start flow-control.
+	 */
 	rets = ishtp_cl_read_start(cl);
 
-	dev->print_log(dev, "%s() successful\n", __func__);
-
 	return rets;
 }
 EXPORT_SYMBOL(ishtp_cl_connect);
 
 /**
+ * ishtp_cl_establish_connection() - Establish connection with the firmware
+ * @cl: client device instance
+ * @uuid: uuid of the client to search
+ * @tx_size: TX ring buffer size
+ * @rx_size: RX ring buffer size
+ * @reset: true if called for reset connection, otherwise for first connection
+ *
+ * This is a helper function for client driver to build connection with firmware.
+ * If it's first time connecting to the firmware, set reset to false, this
+ * function will link client to bus, find client id and send connect request to
+ * the firmware.
+ *
+ * If it's called for reset handler where client lost connection after
+ * firmware reset, set reset to true, this function will reinit client state and
+ * establish connection again. In this case, this function reuses current client
+ * structure and ring buffers to avoid allocation failure and memory fragments.
+ *
+ * Return: 0 for successful connection with the firmware,
+ * or error code on failure
+ */
+int ishtp_cl_establish_connection(struct ishtp_cl *cl, const guid_t *uuid,
+				  int tx_size, int rx_size, bool reset)
+{
+	struct ishtp_device *dev;
+	struct ishtp_fw_client *fw_client;
+	int rets;
+
+	if (!cl || !cl->dev)
+		return -ENODEV;
+
+	dev = cl->dev;
+
+	ishtp_set_connection_state(cl, ISHTP_CL_INITIALIZING);
+
+	/* reinit ishtp_cl structure if call for reset */
+	if (reset) {
+		cl->host_client_id = 0;
+		cl->fw_client_id = 0;
+		cl->ishtp_flow_ctrl_creds = 0;
+		cl->out_flow_ctrl_creds = 0;
+
+		cl->last_tx_path = CL_TX_PATH_IPC;
+		cl->last_dma_acked = 1;
+		cl->last_dma_addr = NULL;
+		cl->last_ipc_acked = 1;
+
+		cl->sending = 0;
+		cl->err_send_msg = 0;
+		cl->err_send_fc = 0;
+
+		cl->send_msg_cnt_ipc = 0;
+		cl->send_msg_cnt_dma = 0;
+		cl->recv_msg_cnt_ipc = 0;
+		cl->recv_msg_cnt_dma = 0;
+		cl->recv_msg_num_frags = 0;
+		cl->ishtp_flow_ctrl_cnt = 0;
+		cl->out_flow_ctrl_cnt = 0;
+	}
+
+	/* link to bus */
+	rets = ishtp_cl_link(cl);
+	if (rets) {
+		dev->print_log(dev, "%s() ishtp_cl_link failed\n", __func__);
+		return rets;
+	}
+
+	/* find firmware client */
+	fw_client = ishtp_fw_cl_get_client(dev, uuid);
+	if (!fw_client) {
+		dev->print_log(dev,
+			       "%s() ish client uuid not found\n", __func__);
+		return -ENOENT;
+	}
+
+	ishtp_set_tx_ring_size(cl, tx_size);
+	ishtp_set_rx_ring_size(cl, rx_size);
+
+	ishtp_cl_set_fw_client_id(cl, ishtp_get_fw_client_id(fw_client));
+
+	ishtp_set_connection_state(cl, ISHTP_CL_CONNECTING);
+
+	/*
+	 * For reset case, not allocate tx/rx ring buffer which are already
+	 * done in ishtp_cl_connect() during first connection.
+	 */
+	if (reset) {
+		rets = ishtp_cl_connect_to_fw(cl);
+		if (!rets)
+			rets = ishtp_cl_read_start(cl);
+		else
+			dev->print_log(dev,
+				"%s() connect to fw failed\n", __func__);
+	} else {
+		rets = ishtp_cl_connect(cl);
+	}
+
+	return rets;
+}
+EXPORT_SYMBOL(ishtp_cl_establish_connection);
+
+/**
+ * ishtp_cl_destroy_connection() - Disconnect with the firmware
+ * @cl: client device instance
+ * @reset: true if called for firmware reset, false for normal disconnection
+ *
+ * This is a helper function for client driver to disconnect with firmware,
+ * unlink to bus and flush message queue.
+ */
+void ishtp_cl_destroy_connection(struct ishtp_cl *cl, bool reset)
+{
+	if (!cl)
+		return;
+
+	if (reset) {
+		/*
+		 * For reset case, connection is already lost during fw reset.
+		 * Just set state to DISCONNECTED is enough.
+		 */
+		ishtp_set_connection_state(cl, ISHTP_CL_DISCONNECTED);
+	} else {
+		if (cl->state != ISHTP_CL_DISCONNECTED) {
+			ishtp_set_connection_state(cl, ISHTP_CL_DISCONNECTING);
+			ishtp_cl_disconnect(cl);
+		}
+	}
+
+	ishtp_cl_unlink(cl);
+	ishtp_cl_flush_queues(cl);
+}
+EXPORT_SYMBOL(ishtp_cl_destroy_connection);
+
+/**
  * ishtp_cl_read_start() - Prepare to read client message
  * @cl: client device instance
  *