Adding upstream version 6.1.76.upstream/6.1.76

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

1 files changed, 995 insertions, 0 deletions

diff --git a/drivers/bluetooth/btmtkuart.c b/drivers/bluetooth/btmtkuart.c
new file mode 100644
index 000000000..04b72394d
--- /dev/null
+++ b/drivers/bluetooth/btmtkuart.c
@@ -0,0 +1,995 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2018 MediaTek Inc.
+
+/*
+ * Bluetooth support for MediaTek serial devices
+ *
+ * Author: Sean Wang <sean.wang@mediatek.com>
+ *
+ */
+
+#include <asm/unaligned.h>
+#include <linux/atomic.h>
+#include <linux/clk.h>
+#include <linux/firmware.h>
+#include <linux/gpio/consumer.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/pm_runtime.h>
+#include <linux/regulator/consumer.h>
+#include <linux/serdev.h>
+#include <linux/skbuff.h>
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+
+#include "h4_recv.h"
+#include "btmtk.h"
+
+#define VERSION "0.2"
+
+#define MTK_STP_TLR_SIZE	2
+
+#define BTMTKUART_TX_STATE_ACTIVE	1
+#define BTMTKUART_TX_STATE_WAKEUP	2
+#define BTMTKUART_TX_WAIT_VND_EVT	3
+#define BTMTKUART_REQUIRED_WAKEUP	4
+
+#define BTMTKUART_FLAG_STANDALONE_HW	 BIT(0)
+
+struct mtk_stp_hdr {
+	u8	prefix;
+	__be16	dlen;
+	u8	cs;
+} __packed;
+
+struct btmtkuart_data {
+	unsigned int flags;
+	const char *fwname;
+};
+
+struct btmtkuart_dev {
+	struct hci_dev *hdev;
+	struct serdev_device *serdev;
+
+	struct clk *clk;
+	struct clk *osc;
+	struct regulator *vcc;
+	struct gpio_desc *reset;
+	struct gpio_desc *boot;
+	struct pinctrl *pinctrl;
+	struct pinctrl_state *pins_runtime;
+	struct pinctrl_state *pins_boot;
+	speed_t	desired_speed;
+	speed_t	curr_speed;
+
+	struct work_struct tx_work;
+	unsigned long tx_state;
+	struct sk_buff_head txq;
+
+	struct sk_buff *rx_skb;
+	struct sk_buff *evt_skb;
+
+	u8	stp_pad[6];
+	u8	stp_cursor;
+	u16	stp_dlen;
+
+	const struct btmtkuart_data *data;
+};
+
+#define btmtkuart_is_standalone(bdev)	\
+	((bdev)->data->flags & BTMTKUART_FLAG_STANDALONE_HW)
+#define btmtkuart_is_builtin_soc(bdev)	\
+	!((bdev)->data->flags & BTMTKUART_FLAG_STANDALONE_HW)
+
+static int mtk_hci_wmt_sync(struct hci_dev *hdev,
+			    struct btmtk_hci_wmt_params *wmt_params)
+{
+	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
+	struct btmtk_hci_wmt_evt_funcc *wmt_evt_funcc;
+	u32 hlen, status = BTMTK_WMT_INVALID;
+	struct btmtk_hci_wmt_evt *wmt_evt;
+	struct btmtk_hci_wmt_cmd *wc;
+	struct btmtk_wmt_hdr *hdr;
+	int err;
+
+	/* Send the WMT command and wait until the WMT event returns */
+	hlen = sizeof(*hdr) + wmt_params->dlen;
+	if (hlen > 255) {
+		err = -EINVAL;
+		goto err_free_skb;
+	}
+
+	wc = kzalloc(hlen, GFP_KERNEL);
+	if (!wc) {
+		err = -ENOMEM;
+		goto err_free_skb;
+	}
+
+	hdr = &wc->hdr;
+	hdr->dir = 1;
+	hdr->op = wmt_params->op;
+	hdr->dlen = cpu_to_le16(wmt_params->dlen + 1);
+	hdr->flag = wmt_params->flag;
+	memcpy(wc->data, wmt_params->data, wmt_params->dlen);
+
+	set_bit(BTMTKUART_TX_WAIT_VND_EVT, &bdev->tx_state);
+
+	err = __hci_cmd_send(hdev, 0xfc6f, hlen, wc);
+	if (err < 0) {
+		clear_bit(BTMTKUART_TX_WAIT_VND_EVT, &bdev->tx_state);
+		goto err_free_wc;
+	}
+
+	/* The vendor specific WMT commands are all answered by a vendor
+	 * specific event and will not have the Command Status or Command
+	 * Complete as with usual HCI command flow control.
+	 *
+	 * After sending the command, wait for BTMTKUART_TX_WAIT_VND_EVT
+	 * state to be cleared. The driver specific event receive routine
+	 * will clear that state and with that indicate completion of the
+	 * WMT command.
+	 */
+	err = wait_on_bit_timeout(&bdev->tx_state, BTMTKUART_TX_WAIT_VND_EVT,
+				  TASK_INTERRUPTIBLE, HCI_INIT_TIMEOUT);
+	if (err == -EINTR) {
+		bt_dev_err(hdev, "Execution of wmt command interrupted");
+		clear_bit(BTMTKUART_TX_WAIT_VND_EVT, &bdev->tx_state);
+		goto err_free_wc;
+	}
+
+	if (err) {
+		bt_dev_err(hdev, "Execution of wmt command timed out");
+		clear_bit(BTMTKUART_TX_WAIT_VND_EVT, &bdev->tx_state);
+		err = -ETIMEDOUT;
+		goto err_free_wc;
+	}
+
+	/* Parse and handle the return WMT event */
+	wmt_evt = (struct btmtk_hci_wmt_evt *)bdev->evt_skb->data;
+	if (wmt_evt->whdr.op != hdr->op) {
+		bt_dev_err(hdev, "Wrong op received %d expected %d",
+			   wmt_evt->whdr.op, hdr->op);
+		err = -EIO;
+		goto err_free_wc;
+	}
+
+	switch (wmt_evt->whdr.op) {
+	case BTMTK_WMT_SEMAPHORE:
+		if (wmt_evt->whdr.flag == 2)
+			status = BTMTK_WMT_PATCH_UNDONE;
+		else
+			status = BTMTK_WMT_PATCH_DONE;
+		break;
+	case BTMTK_WMT_FUNC_CTRL:
+		wmt_evt_funcc = (struct btmtk_hci_wmt_evt_funcc *)wmt_evt;
+		if (be16_to_cpu(wmt_evt_funcc->status) == 0x404)
+			status = BTMTK_WMT_ON_DONE;
+		else if (be16_to_cpu(wmt_evt_funcc->status) == 0x420)
+			status = BTMTK_WMT_ON_PROGRESS;
+		else
+			status = BTMTK_WMT_ON_UNDONE;
+		break;
+	}
+
+	if (wmt_params->status)
+		*wmt_params->status = status;
+
+err_free_wc:
+	kfree(wc);
+err_free_skb:
+	kfree_skb(bdev->evt_skb);
+	bdev->evt_skb = NULL;
+
+	return err;
+}
+
+static int btmtkuart_recv_event(struct hci_dev *hdev, struct sk_buff *skb)
+{
+	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
+	struct hci_event_hdr *hdr = (void *)skb->data;
+	int err;
+
+	/* When someone waits for the WMT event, the skb is being cloned
+	 * and being processed the events from there then.
+	 */
+	if (test_bit(BTMTKUART_TX_WAIT_VND_EVT, &bdev->tx_state)) {
+		bdev->evt_skb = skb_clone(skb, GFP_KERNEL);
+		if (!bdev->evt_skb) {
+			err = -ENOMEM;
+			goto err_out;
+		}
+	}
+
+	err = hci_recv_frame(hdev, skb);
+	if (err < 0)
+		goto err_free_skb;
+
+	if (hdr->evt == HCI_EV_WMT) {
+		if (test_and_clear_bit(BTMTKUART_TX_WAIT_VND_EVT,
+				       &bdev->tx_state)) {
+			/* Barrier to sync with other CPUs */
+			smp_mb__after_atomic();
+			wake_up_bit(&bdev->tx_state, BTMTKUART_TX_WAIT_VND_EVT);
+		}
+	}
+
+	return 0;
+
+err_free_skb:
+	kfree_skb(bdev->evt_skb);
+	bdev->evt_skb = NULL;
+
+err_out:
+	return err;
+}
+
+static const struct h4_recv_pkt mtk_recv_pkts[] = {
+	{ H4_RECV_ACL,      .recv = hci_recv_frame },
+	{ H4_RECV_SCO,      .recv = hci_recv_frame },
+	{ H4_RECV_EVENT,    .recv = btmtkuart_recv_event },
+};
+
+static void btmtkuart_tx_work(struct work_struct *work)
+{
+	struct btmtkuart_dev *bdev = container_of(work, struct btmtkuart_dev,
+						   tx_work);
+	struct serdev_device *serdev = bdev->serdev;
+	struct hci_dev *hdev = bdev->hdev;
+
+	while (1) {
+		clear_bit(BTMTKUART_TX_STATE_WAKEUP, &bdev->tx_state);
+
+		while (1) {
+			struct sk_buff *skb = skb_dequeue(&bdev->txq);
+			int len;
+
+			if (!skb)
+				break;
+
+			len = serdev_device_write_buf(serdev, skb->data,
+						      skb->len);
+			hdev->stat.byte_tx += len;
+
+			skb_pull(skb, len);
+			if (skb->len > 0) {
+				skb_queue_head(&bdev->txq, skb);
+				break;
+			}
+
+			switch (hci_skb_pkt_type(skb)) {
+			case HCI_COMMAND_PKT:
+				hdev->stat.cmd_tx++;
+				break;
+			case HCI_ACLDATA_PKT:
+				hdev->stat.acl_tx++;
+				break;
+			case HCI_SCODATA_PKT:
+				hdev->stat.sco_tx++;
+				break;
+			}
+
+			kfree_skb(skb);
+		}
+
+		if (!test_bit(BTMTKUART_TX_STATE_WAKEUP, &bdev->tx_state))
+			break;
+	}
+
+	clear_bit(BTMTKUART_TX_STATE_ACTIVE, &bdev->tx_state);
+}
+
+static void btmtkuart_tx_wakeup(struct btmtkuart_dev *bdev)
+{
+	if (test_and_set_bit(BTMTKUART_TX_STATE_ACTIVE, &bdev->tx_state))
+		set_bit(BTMTKUART_TX_STATE_WAKEUP, &bdev->tx_state);
+
+	schedule_work(&bdev->tx_work);
+}
+
+static const unsigned char *
+mtk_stp_split(struct btmtkuart_dev *bdev, const unsigned char *data, int count,
+	      int *sz_h4)
+{
+	struct mtk_stp_hdr *shdr;
+
+	/* The cursor is reset when all the data of STP is consumed out */
+	if (!bdev->stp_dlen && bdev->stp_cursor >= 6)
+		bdev->stp_cursor = 0;
+
+	/* Filling pad until all STP info is obtained */
+	while (bdev->stp_cursor < 6 && count > 0) {
+		bdev->stp_pad[bdev->stp_cursor] = *data;
+		bdev->stp_cursor++;
+		data++;
+		count--;
+	}
+
+	/* Retrieve STP info and have a sanity check */
+	if (!bdev->stp_dlen && bdev->stp_cursor >= 6) {
+		shdr = (struct mtk_stp_hdr *)&bdev->stp_pad[2];
+		bdev->stp_dlen = be16_to_cpu(shdr->dlen) & 0x0fff;
+
+		/* Resync STP when unexpected data is being read */
+		if (shdr->prefix != 0x80 || bdev->stp_dlen > 2048) {
+			bt_dev_err(bdev->hdev, "stp format unexpect (%d, %d)",
+				   shdr->prefix, bdev->stp_dlen);
+			bdev->stp_cursor = 2;
+			bdev->stp_dlen = 0;
+		}
+	}
+
+	/* Directly quit when there's no data found for H4 can process */
+	if (count <= 0)
+		return NULL;
+
+	/* Tranlate to how much the size of data H4 can handle so far */
+	*sz_h4 = min_t(int, count, bdev->stp_dlen);
+
+	/* Update the remaining size of STP packet */
+	bdev->stp_dlen -= *sz_h4;
+
+	/* Data points to STP payload which can be handled by H4 */
+	return data;
+}
+
+static void btmtkuart_recv(struct hci_dev *hdev, const u8 *data, size_t count)
+{
+	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
+	const unsigned char *p_left = data, *p_h4;
+	int sz_left = count, sz_h4, adv;
+	int err;
+
+	while (sz_left > 0) {
+		/*  The serial data received from MT7622 BT controller is
+		 *  at all time padded around with the STP header and tailer.
+		 *
+		 *  A full STP packet is looking like
+		 *   -----------------------------------
+		 *  | STP header  |  H:4   | STP tailer |
+		 *   -----------------------------------
+		 *  but it doesn't guarantee to contain a full H:4 packet which
+		 *  means that it's possible for multiple STP packets forms a
+		 *  full H:4 packet that means extra STP header + length doesn't
+		 *  indicate a full H:4 frame, things can fragment. Whose length
+		 *  recorded in STP header just shows up the most length the
+		 *  H:4 engine can handle currently.
+		 */
+
+		p_h4 = mtk_stp_split(bdev, p_left, sz_left, &sz_h4);
+		if (!p_h4)
+			break;
+
+		adv = p_h4 - p_left;
+		sz_left -= adv;
+		p_left += adv;
+
+		bdev->rx_skb = h4_recv_buf(bdev->hdev, bdev->rx_skb, p_h4,
+					   sz_h4, mtk_recv_pkts,
+					   ARRAY_SIZE(mtk_recv_pkts));
+		if (IS_ERR(bdev->rx_skb)) {
+			err = PTR_ERR(bdev->rx_skb);
+			bt_dev_err(bdev->hdev,
+				   "Frame reassembly failed (%d)", err);
+			bdev->rx_skb = NULL;
+			return;
+		}
+
+		sz_left -= sz_h4;
+		p_left += sz_h4;
+	}
+}
+
+static int btmtkuart_receive_buf(struct serdev_device *serdev, const u8 *data,
+				 size_t count)
+{
+	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
+
+	btmtkuart_recv(bdev->hdev, data, count);
+
+	bdev->hdev->stat.byte_rx += count;
+
+	return count;
+}
+
+static void btmtkuart_write_wakeup(struct serdev_device *serdev)
+{
+	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
+
+	btmtkuart_tx_wakeup(bdev);
+}
+
+static const struct serdev_device_ops btmtkuart_client_ops = {
+	.receive_buf = btmtkuart_receive_buf,
+	.write_wakeup = btmtkuart_write_wakeup,
+};
+
+static int btmtkuart_open(struct hci_dev *hdev)
+{
+	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
+	struct device *dev;
+	int err;
+
+	err = serdev_device_open(bdev->serdev);
+	if (err) {
+		bt_dev_err(hdev, "Unable to open UART device %s",
+			   dev_name(&bdev->serdev->dev));
+		goto err_open;
+	}
+
+	if (btmtkuart_is_standalone(bdev)) {
+		if (bdev->curr_speed != bdev->desired_speed)
+			err = serdev_device_set_baudrate(bdev->serdev,
+							 115200);
+		else
+			err = serdev_device_set_baudrate(bdev->serdev,
+							 bdev->desired_speed);
+
+		if (err < 0) {
+			bt_dev_err(hdev, "Unable to set baudrate UART device %s",
+				   dev_name(&bdev->serdev->dev));
+			goto  err_serdev_close;
+		}
+
+		serdev_device_set_flow_control(bdev->serdev, false);
+	}
+
+	bdev->stp_cursor = 2;
+	bdev->stp_dlen = 0;
+
+	dev = &bdev->serdev->dev;
+
+	/* Enable the power domain and clock the device requires */
+	pm_runtime_enable(dev);
+	err = pm_runtime_resume_and_get(dev);
+	if (err < 0)
+		goto err_disable_rpm;
+
+	err = clk_prepare_enable(bdev->clk);
+	if (err < 0)
+		goto err_put_rpm;
+
+	return 0;
+
+err_put_rpm:
+	pm_runtime_put_sync(dev);
+err_disable_rpm:
+	pm_runtime_disable(dev);
+err_serdev_close:
+	serdev_device_close(bdev->serdev);
+err_open:
+	return err;
+}
+
+static int btmtkuart_close(struct hci_dev *hdev)
+{
+	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
+	struct device *dev = &bdev->serdev->dev;
+
+	/* Shutdown the clock and power domain the device requires */
+	clk_disable_unprepare(bdev->clk);
+	pm_runtime_put_sync(dev);
+	pm_runtime_disable(dev);
+
+	serdev_device_close(bdev->serdev);
+
+	return 0;
+}
+
+static int btmtkuart_flush(struct hci_dev *hdev)
+{
+	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
+
+	/* Flush any pending characters */
+	serdev_device_write_flush(bdev->serdev);
+	skb_queue_purge(&bdev->txq);
+
+	cancel_work_sync(&bdev->tx_work);
+
+	kfree_skb(bdev->rx_skb);
+	bdev->rx_skb = NULL;
+
+	bdev->stp_cursor = 2;
+	bdev->stp_dlen = 0;
+
+	return 0;
+}
+
+static int btmtkuart_func_query(struct hci_dev *hdev)
+{
+	struct btmtk_hci_wmt_params wmt_params;
+	int status, err;
+	u8 param = 0;
+
+	/* Query whether the function is enabled */
+	wmt_params.op = BTMTK_WMT_FUNC_CTRL;
+	wmt_params.flag = 4;
+	wmt_params.dlen = sizeof(param);
+	wmt_params.data = &param;
+	wmt_params.status = &status;
+
+	err = mtk_hci_wmt_sync(hdev, &wmt_params);
+	if (err < 0) {
+		bt_dev_err(hdev, "Failed to query function status (%d)", err);
+		return err;
+	}
+
+	return status;
+}
+
+static int btmtkuart_change_baudrate(struct hci_dev *hdev)
+{
+	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
+	struct btmtk_hci_wmt_params wmt_params;
+	__le32 baudrate;
+	u8 param;
+	int err;
+
+	/* Indicate the device to enter the probe state the host is
+	 * ready to change a new baudrate.
+	 */
+	baudrate = cpu_to_le32(bdev->desired_speed);
+	wmt_params.op = BTMTK_WMT_HIF;
+	wmt_params.flag = 1;
+	wmt_params.dlen = 4;
+	wmt_params.data = &baudrate;
+	wmt_params.status = NULL;
+
+	err = mtk_hci_wmt_sync(hdev, &wmt_params);
+	if (err < 0) {
+		bt_dev_err(hdev, "Failed to device baudrate (%d)", err);
+		return err;
+	}
+
+	err = serdev_device_set_baudrate(bdev->serdev,
+					 bdev->desired_speed);
+	if (err < 0) {
+		bt_dev_err(hdev, "Failed to set up host baudrate (%d)",
+			   err);
+		return err;
+	}
+
+	serdev_device_set_flow_control(bdev->serdev, false);
+
+	/* Send a dummy byte 0xff to activate the new baudrate */
+	param = 0xff;
+	err = serdev_device_write_buf(bdev->serdev, &param, sizeof(param));
+	if (err < 0 || err < sizeof(param))
+		return err;
+
+	serdev_device_wait_until_sent(bdev->serdev, 0);
+
+	/* Wait some time for the device changing baudrate done */
+	usleep_range(20000, 22000);
+
+	/* Test the new baudrate */
+	wmt_params.op = BTMTK_WMT_TEST;
+	wmt_params.flag = 7;
+	wmt_params.dlen = 0;
+	wmt_params.data = NULL;
+	wmt_params.status = NULL;
+
+	err = mtk_hci_wmt_sync(hdev, &wmt_params);
+	if (err < 0) {
+		bt_dev_err(hdev, "Failed to test new baudrate (%d)",
+			   err);
+		return err;
+	}
+
+	bdev->curr_speed = bdev->desired_speed;
+
+	return 0;
+}
+
+static int btmtkuart_setup(struct hci_dev *hdev)
+{
+	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
+	struct btmtk_hci_wmt_params wmt_params;
+	ktime_t calltime, delta, rettime;
+	struct btmtk_tci_sleep tci_sleep;
+	unsigned long long duration;
+	struct sk_buff *skb;
+	int err, status;
+	u8 param = 0x1;
+
+	calltime = ktime_get();
+
+	/* Wakeup MCUSYS is required for certain devices before we start to
+	 * do any setups.
+	 */
+	if (test_bit(BTMTKUART_REQUIRED_WAKEUP, &bdev->tx_state)) {
+		wmt_params.op = BTMTK_WMT_WAKEUP;
+		wmt_params.flag = 3;
+		wmt_params.dlen = 0;
+		wmt_params.data = NULL;
+		wmt_params.status = NULL;
+
+		err = mtk_hci_wmt_sync(hdev, &wmt_params);
+		if (err < 0) {
+			bt_dev_err(hdev, "Failed to wakeup the chip (%d)", err);
+			return err;
+		}
+
+		clear_bit(BTMTKUART_REQUIRED_WAKEUP, &bdev->tx_state);
+	}
+
+	if (btmtkuart_is_standalone(bdev))
+		btmtkuart_change_baudrate(hdev);
+
+	/* Query whether the firmware is already download */
+	wmt_params.op = BTMTK_WMT_SEMAPHORE;
+	wmt_params.flag = 1;
+	wmt_params.dlen = 0;
+	wmt_params.data = NULL;
+	wmt_params.status = &status;
+
+	err = mtk_hci_wmt_sync(hdev, &wmt_params);
+	if (err < 0) {
+		bt_dev_err(hdev, "Failed to query firmware status (%d)", err);
+		return err;
+	}
+
+	if (status == BTMTK_WMT_PATCH_DONE) {
+		bt_dev_info(hdev, "Firmware already downloaded");
+		goto ignore_setup_fw;
+	}
+
+	/* Setup a firmware which the device definitely requires */
+	err = btmtk_setup_firmware(hdev, bdev->data->fwname, mtk_hci_wmt_sync);
+	if (err < 0)
+		return err;
+
+ignore_setup_fw:
+	/* Query whether the device is already enabled */
+	err = readx_poll_timeout(btmtkuart_func_query, hdev, status,
+				 status < 0 || status != BTMTK_WMT_ON_PROGRESS,
+				 2000, 5000000);
+	/* -ETIMEDOUT happens */
+	if (err < 0)
+		return err;
+
+	/* The other errors happen in btusb_mtk_func_query */
+	if (status < 0)
+		return status;
+
+	if (status == BTMTK_WMT_ON_DONE) {
+		bt_dev_info(hdev, "function already on");
+		goto ignore_func_on;
+	}
+
+	/* Enable Bluetooth protocol */
+	wmt_params.op = BTMTK_WMT_FUNC_CTRL;
+	wmt_params.flag = 0;
+	wmt_params.dlen = sizeof(param);
+	wmt_params.data = &param;
+	wmt_params.status = NULL;
+
+	err = mtk_hci_wmt_sync(hdev, &wmt_params);
+	if (err < 0) {
+		bt_dev_err(hdev, "Failed to send wmt func ctrl (%d)", err);
+		return err;
+	}
+
+ignore_func_on:
+	/* Apply the low power environment setup */
+	tci_sleep.mode = 0x5;
+	tci_sleep.duration = cpu_to_le16(0x640);
+	tci_sleep.host_duration = cpu_to_le16(0x640);
+	tci_sleep.host_wakeup_pin = 0;
+	tci_sleep.time_compensation = 0;
+
+	skb = __hci_cmd_sync(hdev, 0xfc7a, sizeof(tci_sleep), &tci_sleep,
+			     HCI_INIT_TIMEOUT);
+	if (IS_ERR(skb)) {
+		err = PTR_ERR(skb);
+		bt_dev_err(hdev, "Failed to apply low power setting (%d)", err);
+		return err;
+	}
+	kfree_skb(skb);
+
+	rettime = ktime_get();
+	delta = ktime_sub(rettime, calltime);
+	duration = (unsigned long long)ktime_to_ns(delta) >> 10;
+
+	bt_dev_info(hdev, "Device setup in %llu usecs", duration);
+
+	return 0;
+}
+
+static int btmtkuart_shutdown(struct hci_dev *hdev)
+{
+	struct btmtk_hci_wmt_params wmt_params;
+	u8 param = 0x0;
+	int err;
+
+	/* Disable the device */
+	wmt_params.op = BTMTK_WMT_FUNC_CTRL;
+	wmt_params.flag = 0;
+	wmt_params.dlen = sizeof(param);
+	wmt_params.data = &param;
+	wmt_params.status = NULL;
+
+	err = mtk_hci_wmt_sync(hdev, &wmt_params);
+	if (err < 0) {
+		bt_dev_err(hdev, "Failed to send wmt func ctrl (%d)", err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int btmtkuart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
+{
+	struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
+	struct mtk_stp_hdr *shdr;
+	int err, dlen, type = 0;
+
+	/* Prepend skb with frame type */
+	memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
+
+	/* Make sure that there is enough rooms for STP header and trailer */
+	if (unlikely(skb_headroom(skb) < sizeof(*shdr)) ||
+	    (skb_tailroom(skb) < MTK_STP_TLR_SIZE)) {
+		err = pskb_expand_head(skb, sizeof(*shdr), MTK_STP_TLR_SIZE,
+				       GFP_ATOMIC);
+		if (err < 0)
+			return err;
+	}
+
+	/* Add the STP header */
+	dlen = skb->len;
+	shdr = skb_push(skb, sizeof(*shdr));
+	shdr->prefix = 0x80;
+	shdr->dlen = cpu_to_be16((dlen & 0x0fff) | (type << 12));
+	shdr->cs = 0;		/* MT7622 doesn't care about checksum value */
+
+	/* Add the STP trailer */
+	skb_put_zero(skb, MTK_STP_TLR_SIZE);
+
+	skb_queue_tail(&bdev->txq, skb);
+
+	btmtkuart_tx_wakeup(bdev);
+	return 0;
+}
+
+static int btmtkuart_parse_dt(struct serdev_device *serdev)
+{
+	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
+	struct device_node *node = serdev->dev.of_node;
+	u32 speed = 921600;
+	int err;
+
+	if (btmtkuart_is_standalone(bdev)) {
+		of_property_read_u32(node, "current-speed", &speed);
+
+		bdev->desired_speed = speed;
+
+		bdev->vcc = devm_regulator_get(&serdev->dev, "vcc");
+		if (IS_ERR(bdev->vcc)) {
+			err = PTR_ERR(bdev->vcc);
+			return err;
+		}
+
+		bdev->osc = devm_clk_get_optional(&serdev->dev, "osc");
+		if (IS_ERR(bdev->osc)) {
+			err = PTR_ERR(bdev->osc);
+			return err;
+		}
+
+		bdev->boot = devm_gpiod_get_optional(&serdev->dev, "boot",
+						     GPIOD_OUT_LOW);
+		if (IS_ERR(bdev->boot)) {
+			err = PTR_ERR(bdev->boot);
+			return err;
+		}
+
+		bdev->pinctrl = devm_pinctrl_get(&serdev->dev);
+		if (IS_ERR(bdev->pinctrl)) {
+			err = PTR_ERR(bdev->pinctrl);
+			return err;
+		}
+
+		bdev->pins_boot = pinctrl_lookup_state(bdev->pinctrl,
+						       "default");
+		if (IS_ERR(bdev->pins_boot) && !bdev->boot) {
+			err = PTR_ERR(bdev->pins_boot);
+			dev_err(&serdev->dev,
+				"Should assign RXD to LOW at boot stage\n");
+			return err;
+		}
+
+		bdev->pins_runtime = pinctrl_lookup_state(bdev->pinctrl,
+							  "runtime");
+		if (IS_ERR(bdev->pins_runtime)) {
+			err = PTR_ERR(bdev->pins_runtime);
+			return err;
+		}
+
+		bdev->reset = devm_gpiod_get_optional(&serdev->dev, "reset",
+						      GPIOD_OUT_LOW);
+		if (IS_ERR(bdev->reset)) {
+			err = PTR_ERR(bdev->reset);
+			return err;
+		}
+	} else if (btmtkuart_is_builtin_soc(bdev)) {
+		bdev->clk = devm_clk_get(&serdev->dev, "ref");
+		if (IS_ERR(bdev->clk))
+			return PTR_ERR(bdev->clk);
+	}
+
+	return 0;
+}
+
+static int btmtkuart_probe(struct serdev_device *serdev)
+{
+	struct btmtkuart_dev *bdev;
+	struct hci_dev *hdev;
+	int err;
+
+	bdev = devm_kzalloc(&serdev->dev, sizeof(*bdev), GFP_KERNEL);
+	if (!bdev)
+		return -ENOMEM;
+
+	bdev->data = of_device_get_match_data(&serdev->dev);
+	if (!bdev->data)
+		return -ENODEV;
+
+	bdev->serdev = serdev;
+	serdev_device_set_drvdata(serdev, bdev);
+
+	serdev_device_set_client_ops(serdev, &btmtkuart_client_ops);
+
+	err = btmtkuart_parse_dt(serdev);
+	if (err < 0)
+		return err;
+
+	INIT_WORK(&bdev->tx_work, btmtkuart_tx_work);
+	skb_queue_head_init(&bdev->txq);
+
+	/* Initialize and register HCI device */
+	hdev = hci_alloc_dev();
+	if (!hdev) {
+		dev_err(&serdev->dev, "Can't allocate HCI device\n");
+		return -ENOMEM;
+	}
+
+	bdev->hdev = hdev;
+
+	hdev->bus = HCI_UART;
+	hci_set_drvdata(hdev, bdev);
+
+	hdev->open     = btmtkuart_open;
+	hdev->close    = btmtkuart_close;
+	hdev->flush    = btmtkuart_flush;
+	hdev->setup    = btmtkuart_setup;
+	hdev->shutdown = btmtkuart_shutdown;
+	hdev->send     = btmtkuart_send_frame;
+	hdev->set_bdaddr = btmtk_set_bdaddr;
+	SET_HCIDEV_DEV(hdev, &serdev->dev);
+
+	hdev->manufacturer = 70;
+	set_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks);
+
+	if (btmtkuart_is_standalone(bdev)) {
+		err = clk_prepare_enable(bdev->osc);
+		if (err < 0)
+			goto err_hci_free_dev;
+
+		if (bdev->boot) {
+			gpiod_set_value_cansleep(bdev->boot, 1);
+		} else {
+			/* Switch to the specific pin state for the booting
+			 * requires.
+			 */
+			pinctrl_select_state(bdev->pinctrl, bdev->pins_boot);
+		}
+
+		/* Power on */
+		err = regulator_enable(bdev->vcc);
+		if (err < 0)
+			goto err_clk_disable_unprepare;
+
+		/* Reset if the reset-gpios is available otherwise the board
+		 * -level design should be guaranteed.
+		 */
+		if (bdev->reset) {
+			gpiod_set_value_cansleep(bdev->reset, 1);
+			usleep_range(1000, 2000);
+			gpiod_set_value_cansleep(bdev->reset, 0);
+		}
+
+		/* Wait some time until device got ready and switch to the pin
+		 * mode the device requires for UART transfers.
+		 */
+		msleep(50);
+
+		if (bdev->boot)
+			devm_gpiod_put(&serdev->dev, bdev->boot);
+
+		pinctrl_select_state(bdev->pinctrl, bdev->pins_runtime);
+
+		/* A standalone device doesn't depends on power domain on SoC,
+		 * so mark it as no callbacks.
+		 */
+		pm_runtime_no_callbacks(&serdev->dev);
+
+		set_bit(BTMTKUART_REQUIRED_WAKEUP, &bdev->tx_state);
+	}
+
+	err = hci_register_dev(hdev);
+	if (err < 0) {
+		dev_err(&serdev->dev, "Can't register HCI device\n");
+		goto err_regulator_disable;
+	}
+
+	return 0;
+
+err_regulator_disable:
+	if (btmtkuart_is_standalone(bdev))
+		regulator_disable(bdev->vcc);
+err_clk_disable_unprepare:
+	if (btmtkuart_is_standalone(bdev))
+		clk_disable_unprepare(bdev->osc);
+err_hci_free_dev:
+	hci_free_dev(hdev);
+
+	return err;
+}
+
+static void btmtkuart_remove(struct serdev_device *serdev)
+{
+	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
+	struct hci_dev *hdev = bdev->hdev;
+
+	if (btmtkuart_is_standalone(bdev)) {
+		regulator_disable(bdev->vcc);
+		clk_disable_unprepare(bdev->osc);
+	}
+
+	hci_unregister_dev(hdev);
+	hci_free_dev(hdev);
+}
+
+static const struct btmtkuart_data mt7622_data = {
+	.fwname = FIRMWARE_MT7622,
+};
+
+static const struct btmtkuart_data mt7663_data = {
+	.flags = BTMTKUART_FLAG_STANDALONE_HW,
+	.fwname = FIRMWARE_MT7663,
+};
+
+static const struct btmtkuart_data mt7668_data = {
+	.flags = BTMTKUART_FLAG_STANDALONE_HW,
+	.fwname = FIRMWARE_MT7668,
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id mtk_of_match_table[] = {
+	{ .compatible = "mediatek,mt7622-bluetooth", .data = &mt7622_data},
+	{ .compatible = "mediatek,mt7663u-bluetooth", .data = &mt7663_data},
+	{ .compatible = "mediatek,mt7668u-bluetooth", .data = &mt7668_data},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, mtk_of_match_table);
+#endif
+
+static struct serdev_device_driver btmtkuart_driver = {
+	.probe = btmtkuart_probe,
+	.remove = btmtkuart_remove,
+	.driver = {
+		.name = "btmtkuart",
+		.of_match_table = of_match_ptr(mtk_of_match_table),
+	},
+};
+
+module_serdev_device_driver(btmtkuart_driver);
+
+MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
+MODULE_DESCRIPTION("MediaTek Bluetooth Serial driver ver " VERSION);
+MODULE_VERSION(VERSION);
+MODULE_LICENSE("GPL");