[PATCH v8 0/3] add support for Bluetooth on MT7622 SoC

[PATCH v8 0/3] add support for Bluetooth on MT7622 SoC

[sean.wang at mediatek.com]

From: Sean Wang <sean.wang@mediatek.com>

v8 and changes since v7:
 - add updates per these suggestions mentioned in [1][2]
 - remove the hack atomic_inc(&hdev->cmd_cnt) mentioned in [2] because it should
   be better to be considered in the core

[1] http://lists.infradead.org/pipermail/linux-mediatek/2018-August/014516.html
[2] http://lists.infradead.org/pipermail/linux-mediatek/2018-August/014518.html

v7 and changes since v6:
 - drop already applied patches
 - move clk_* and pm_* operation to ->open and ->close 
 - label this driver as BT_MTKUART
 - make code style aligned with the other drivers and code better to read
   as these suggestions and fixes are mentioned in [1]

[1] http://lists.infradead.org/pipermail/linux-mediatek/2018-July/014458.html

v6 and changes since v5:
 - make btmtkuart become a separate driver.
 - drop already applied patches and the patch for btuart driver
 - refine comments in driver allowing people know that mtk extra header
   + length doesn't indicate a full H:4 frame, things can fragment.
 - enhance dt-binding document with removing mistaken added " and improve
   English sentence.
 - remove unnecessary '\n' with bt_dev_err.
 - refine code style.
 - set hdev->manufacturer as mtk id.

v5 and changes since v4:
 - add Reviewed-by Tag from Ulf Hansson for patch 2
 - remove default y in Kconfig for btmtkuart selection to avoid overkill for
   users which would like to have less an amount on stuff in kernel.
 - list header declarations in alphabetical order and add a proper blank line
   within.
 - remove unused macro.
 - use sizeof to calculate structure size instead of an aextra macro to hardcode.
 - use struct hci_dev * as input paraments for mtk_hci_wmt_sync and mtk_setup_fw
   for that can be reused in mtk bluetooth with other interfaces.
 - remove unused local variabled in mtk_btuart_recv.
 - remove superfluous :8 for dlen2 in struct mtk_stp_hdr definition.
 - give a reasonable naming for these labels and add a pm_runtime_put_noidle()
   in the path undoing failing pm_runtime_get_sync().
 - Turn __u8 into u8 in struct mtk_stp_hdr.

 Really thanks for these reviews by Johan Hovold and Andy Shevchenko

v4 and changes since v3:
 - refine patch 2 based on commit 919b7308fcc4 to allow that
   dev_pm_domain_attach() will return better error codes. 

v3 and changes since v2
* all changes happen on patch 6
 - fix up SPDX license style for btmtkuart.h.
 - change firmware download from in ACL data to in HCI commands
   and then remove unused mtk_acl_wmt_sync and related code.
 - add a workaround replacing bad vendor event id 0xe4 with 0xff every
   vendor should use.
 - add a sanity check for mtk_hci_wmt_sync to verifying if
   input parameters are valid.
 - add an atomic_inc(&bdev->hdev->cmd_cnt) for __hci_cmd_sync_ev.
 - be changed to use firmware with a header called mt7622pr2h.bin.

v2 and changes since v1
 - Dropped patches already being applied
 - Rewirte the whole driver using btuart [1], and add slight extension
   of btuart to fit into btmtkuart driver. Beware that [1] is also pulled
   into one part of the series for avoiding any breakage when the patchset
   is being compiled.

[1] btuart 
	https://www.spinics.net/lists/linux-bluetooth/msg74918.html

v1:

Hi,

This patchset introduces built-in Bluetooth support on MT7622 SoC.
And, it should be simple to make an extension to support other
MediaTek SoCs with adjusting a few of changes on the initialization
sequence of the device.

Before the main driver is being introduced, a few of things about
power-domain management should be re-worked for serdev core and MediaTek
SCPSYS to allow the Bluetooth to properly power up.

Patch 2: add a generic way attaching power domain to serdev
Patch 3 and 4: add cleanups with reuse APIs from Linux core
Patch 5: fix a limitation about power enablement Bluetooth depends on
Patch 1, 6 and 7: the major part of adding Bluetooth support to MT7622
	
	Sean

Sean Wang (3):
  dt-bindings: net: bluetooth: Add mediatek-bluetooth
  Bluetooth: mediatek: Add protocol support for MediaTek serial devices
  MAINTAINERS: add an entry for MediaTek Bluetooth driver

 .../devicetree/bindings/net/mediatek-bluetooth.txt |  35 ++
 MAINTAINERS                                        |   8 +
 drivers/bluetooth/Kconfig                          |  11 +
 drivers/bluetooth/Makefile                         |   2 +
 drivers/bluetooth/btmtkuart.c                      | 588 +++++++++++++++++++++
 5 files changed, 644 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/mediatek-bluetooth.txt
 create mode 100644 drivers/bluetooth/btmtkuart.c

-- 
2.7.4

[PATCH v8 1/3] dt-bindings: net: bluetooth: Add mediatek-bluetooth

[sean.wang at mediatek.com]

From: Sean Wang <sean.wang@mediatek.com>

Add binding document for a SoC built-in device using MediaTek protocol.
Which could be found on MT7622 SoC or other similar MediaTek SoCs.

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../devicetree/bindings/net/mediatek-bluetooth.txt | 35 ++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/mediatek-bluetooth.txt

diff --git a/Documentation/devicetree/bindings/net/mediatek-bluetooth.txt b/Documentation/devicetree/bindings/net/mediatek-bluetooth.txt
new file mode 100644
index 0000000..14ceb2a
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/mediatek-bluetooth.txt
@@ -0,0 +1,35 @@
+MediaTek SoC built-in Bluetooth Devices
+==================================
+
+This device is a serial attached device to BTIF device and thus it must be a
+child node of the serial node with BTIF. The dt-bindings details for BTIF
+device can be known via Documentation/devicetree/bindings/serial/8250.txt.
+
+Required properties:
+
+- compatible:	Must be
+		  "mediatek,mt7622-bluetooth": for MT7622 SoC
+- clocks:	Should be the clock specifiers corresponding to the entry in
+		clock-names property.
+- clock-names:	Should contain "ref" entries.
+- power-domains: Phandle to the power domain that the device is part of
+
+Example:
+
+	btif: serial at 1100c000 {
+		compatible = "mediatek,mt7622-btif",
+			     "mediatek,mtk-btif";
+		reg = <0 0x1100c000 0 0x1000>;
+		interrupts = <GIC_SPI 90 IRQ_TYPE_LEVEL_LOW>;
+		clocks = <&pericfg CLK_PERI_BTIF_PD>;
+		clock-names = "main";
+		reg-shift = <2>;
+		reg-io-width = <4>;
+
+		bluetooth {
+			compatible = "mediatek,mt7622-bluetooth";
+			power-domains = <&scpsys MT7622_POWER_DOMAIN_WB>;
+			clocks = <&clk25m>;
+			clock-names = "ref";
+		};
+	};
-- 
2.7.4

[PATCH v8 2/3] Bluetooth: mediatek: Add protocol support for MediaTek serial devices

[sean.wang at mediatek.com]

From: Sean Wang <sean.wang@mediatek.com>

This adds a driver based on serdev driver for the MediaTek serial protocol
based on running H:4, which can enable the built-in Bluetooth device inside
MT7622 SoC.

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
---
 drivers/bluetooth/Kconfig     |  11 +
 drivers/bluetooth/Makefile    |   2 +
 drivers/bluetooth/btmtkuart.c | 588 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 601 insertions(+)
 create mode 100644 drivers/bluetooth/btmtkuart.c

diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig
index f3c643a..5ace676 100644
--- a/drivers/bluetooth/Kconfig
+++ b/drivers/bluetooth/Kconfig
@@ -74,6 +74,17 @@ config BT_HCIBTSDIO
 	  Say Y here to compile support for Bluetooth SDIO devices into the
 	  kernel or say M to compile it as module (btsdio).
 
+config BT_MTKUART
+	tristate "MediaTek HCI UART driver"
+	depends on SERIAL_DEV_BUS
+	help
+	  MediaTek Bluetooth HCI UART driver.
+	  This driver is required if you want to use MediaTek Bluetooth
+	  with serial interface.
+
+	  Say Y here to compile support for MediaTek Bluetooth UART devices
+	  into the kernel or say M to compile it as module (btmtkuart).
+
 config BT_HCIUART
 	tristate "HCI UART driver"
 	depends on SERIAL_DEV_BUS || !SERIAL_DEV_BUS
diff --git a/drivers/bluetooth/Makefile b/drivers/bluetooth/Makefile
index ec16c55..12ad6e9 100644
--- a/drivers/bluetooth/Makefile
+++ b/drivers/bluetooth/Makefile
@@ -25,6 +25,8 @@ obj-$(CONFIG_BT_BCM)		+= btbcm.o
 obj-$(CONFIG_BT_RTL)		+= btrtl.o
 obj-$(CONFIG_BT_QCA)		+= btqca.o
 
+obj-$(CONFIG_BT_MTKUART)	+= btmtkuart.o
+
 obj-$(CONFIG_BT_HCIUART_NOKIA)	+= hci_nokia.o
 
 obj-$(CONFIG_BT_HCIRSI)		+= btrsi.o
diff --git a/drivers/bluetooth/btmtkuart.c b/drivers/bluetooth/btmtkuart.c
new file mode 100644
index 0000000..8ec7568
--- /dev/null
+++ b/drivers/bluetooth/btmtkuart.c
@@ -0,0 +1,588 @@
+// 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/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pm_runtime.h>
+#include <linux/serdev.h>
+#include <linux/skbuff.h>
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+
+#include "h4_recv.h"
+
+#define VERSION "0.1"
+
+#define FIRMWARE_MT7622		"mediatek/mt7622pr2h.bin"
+
+#define MTK_STP_TLR_SIZE	2
+
+#define BTMTKUART_TX_STATE_ACTIVE	1
+#define BTMTKUART_TX_STATE_WAKEUP	2
+
+enum {
+	MTK_WMT_PATCH_DWNLD = 0x1,
+	MTK_WMT_FUNC_CTRL = 0x6,
+	MTK_WMT_RST = 0x7
+};
+
+struct mtk_stp_hdr {
+	u8 prefix;
+	u8 dlen1;
+	u8 dlen2;
+	u8 cs;
+} __packed;
+
+struct mtk_wmt_hdr {
+	u8	dir;
+	u8	op;
+	__le16	dlen;
+	u8	flag;
+} __packed;
+
+struct mtk_hci_wmt_cmd {
+	struct mtk_wmt_hdr hdr;
+	u8 data[256];
+} __packed;
+
+struct btmtkuart_dev {
+	struct hci_dev *hdev;
+	struct serdev_device *serdev;
+	struct clk *clk;
+
+	struct work_struct tx_work;
+	unsigned long tx_state;
+	struct sk_buff_head txq;
+
+	struct sk_buff *rx_skb;
+
+	u8	stp_pad[6];
+	u8	stp_cursor;
+	u16	stp_dlen;
+};
+
+static int mtk_hci_wmt_sync(struct hci_dev *hdev, u8 op, u8 flag, u16 plen,
+			    const void *param)
+{
+	struct mtk_hci_wmt_cmd wc;
+	struct mtk_wmt_hdr *hdr;
+	struct sk_buff *skb;
+	u32 hlen;
+
+	hlen = sizeof(*hdr) + plen;
+	if (hlen > 255)
+		return -EINVAL;
+
+	hdr = (struct mtk_wmt_hdr *)&wc;
+	hdr->dir = 1;
+	hdr->op = op;
+	hdr->dlen = cpu_to_le16(plen + 1);
+	hdr->flag = flag;
+	memcpy(wc.data, param, plen);
+
+	skb = __hci_cmd_sync_ev(hdev, 0xfc6f, hlen, &wc, HCI_VENDOR_PKT,
+				HCI_INIT_TIMEOUT);
+
+	if (IS_ERR(skb)) {
+		int err = PTR_ERR(skb);
+
+		bt_dev_err(hdev, "Failed to send wmt cmd (%d)", err);
+		return err;
+	}
+
+	kfree_skb(skb);
+
+	return 0;
+}
+
+static int mtk_setup_fw(struct hci_dev *hdev)
+{
+	const struct firmware *fw;
+	const u8 *fw_ptr;
+	size_t fw_size;
+	int err, dlen;
+	u8 flag;
+
+	err = request_firmware(&fw, FIRMWARE_MT7622, &hdev->dev);
+	if (err < 0) {
+		bt_dev_err(hdev, "Failed to load firmware file (%d)", err);
+		return err;
+	}
+
+	fw_ptr = fw->data;
+	fw_size = fw->size;
+
+	/* The size of patch header is 30 bytes, should be skip. */
+	if (fw_size < 30)
+		return -EINVAL;
+
+	fw_size -= 30;
+	fw_ptr += 30;
+	flag = 1;
+
+	while (fw_size > 0) {
+		dlen = min_t(int, 250, fw_size);
+
+		/* Tell deivice the position in sequence. */
+		if (fw_size - dlen <= 0)
+			flag = 3;
+		else if (fw_size < fw->size - 30)
+			flag = 2;
+
+		err = mtk_hci_wmt_sync(hdev, MTK_WMT_PATCH_DWNLD, flag, dlen,
+				       fw_ptr);
+		if (err < 0)
+			break;
+
+		fw_size -= dlen;
+		fw_ptr += dlen;
+	}
+
+	release_firmware(fw);
+
+	return err;
+}
+
+static int btmtkuart_recv_event(struct hci_dev *hdev, struct sk_buff *skb)
+{
+	struct hci_event_hdr *hdr = (void *)skb->data;
+
+	/* Fix up the vendor event id with HCI_VENDOR_PKT instead of
+	 * 0xe4 so that btmon can parse the kind of vendor event properly.
+	 */
+	if (hdr->evt == 0xe4)
+		hdr->evt = HCI_VENDOR_PKT;
+
+	return hci_recv_frame(hdev, skb);
+}
+
+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 = (shdr->dlen1 & 0xf) << 8 | shdr->dlen2;
+
+		/* 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 int 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,
+					   sizeof(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 err;
+		}
+
+		sz_left -= sz_h4;
+		p_left += sz_h4;
+	}
+
+	return 0;
+}
+
+static int btmtkuart_receive_buf(struct serdev_device *serdev, const u8 *data,
+				 size_t count)
+{
+	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
+	int err;
+
+	err = btmtkuart_recv(bdev->hdev, data, count);
+	if (err < 0)
+		return err;
+
+	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;
+	}
+
+	dev = &bdev->serdev->dev;
+
+	bdev->stp_cursor = 2;
+	bdev->stp_dlen = 0;
+
+	/* Enable the power domain and clock the device requires. */
+	pm_runtime_enable(dev);
+	err = pm_runtime_get_sync(dev);
+	if (err < 0) {
+		pm_runtime_put_noidle(dev);
+		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_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_setup(struct hci_dev *hdev)
+{
+	u8 param = 0x1;
+	int err = 0;
+
+	/* Setup a firmware which the device definitely requires. */
+	err = mtk_setup_fw(hdev);
+	if (err < 0)
+		return err;
+
+	/* Activate funciton the firmware providing to. */
+	err = mtk_hci_wmt_sync(hdev, MTK_WMT_RST, 0x4, 0, 0);
+	if (err < 0)
+		return err;
+
+	/* Enable Bluetooth protocol. */
+	err = mtk_hci_wmt_sync(hdev, MTK_WMT_FUNC_CTRL, 0x0, sizeof(param),
+			       &param);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+static int btmtkuart_shutdown(struct hci_dev *hdev)
+{
+	u8 param = 0x0;
+	int err;
+
+	/* Disable the device. */
+	err = mtk_hci_wmt_sync(hdev, MTK_WMT_FUNC_CTRL, 0x0, sizeof(param),
+			       &param);
+
+	return err;
+}
+
+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;
+	u8 *p;
+
+	/* Prepend skb with frame type */
+	memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
+	dlen = skb->len;
+
+	/* 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 */
+	shdr = skb_push(skb, sizeof(*shdr));
+	p = (u8 *)shdr;
+	shdr->prefix = 0x80;
+	shdr->dlen1 = (dlen & 0xf00) >> 8;
+	shdr->dlen2 = dlen & 0xff;
+	/* MT7622 don't care the checksum value */
+	shdr->cs = 0;
+	/* 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_probe(struct serdev_device *serdev)
+{
+	struct btmtkuart_dev *bdev;
+	struct hci_dev *hdev;
+
+	bdev = devm_kzalloc(&serdev->dev, sizeof(*bdev), GFP_KERNEL);
+	if (!bdev)
+		return -ENOMEM;
+
+	bdev->clk = devm_clk_get(&serdev->dev, "ref");
+	if (IS_ERR(bdev->clk))
+		return PTR_ERR(bdev->clk);
+
+	bdev->serdev = serdev;
+	serdev_device_set_drvdata(serdev, bdev);
+
+	serdev_device_set_client_ops(serdev, &btmtkuart_client_ops);
+
+	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;
+	SET_HCIDEV_DEV(hdev, &serdev->dev);
+
+	hdev->manufacturer = 70;
+	set_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks);
+
+	if (hci_register_dev(hdev) < 0) {
+		dev_err(&serdev->dev, "Can't register HCI device\n");
+		hci_free_dev(hdev);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static void btmtkuart_remove(struct serdev_device *serdev)
+{
+	struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
+	struct hci_dev *hdev = bdev->hdev;
+
+	hci_unregister_dev(hdev);
+	hci_free_dev(hdev);
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id mtk_of_match_table[] = {
+	{ .compatible = "mediatek,mt7622-bluetooth"},
+	{ }
+};
+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");
+MODULE_FIRMWARE(FIRMWARE_MT7622);
-- 
2.7.4

[PATCH v8 3/3] MAINTAINERS: add an entry for MediaTek Bluetooth driver

[sean.wang at mediatek.com]

From: Sean Wang <sean.wang@mediatek.com>

Add an entry for the MediaTek Bluetooth driver.

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
---
 MAINTAINERS | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 0f2cce4..e983d9e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9144,6 +9144,14 @@ F:	include/uapi/linux/meye.h
 F:	include/uapi/linux/ivtv*
 F:	include/uapi/linux/uvcvideo.h
 
+MEDIATEK BLUETOOTH DRIVER
+M:	Sean Wang <sean.wang@mediatek.com>
+L:	linux-bluetooth at vger.kernel.org
+L:	linux-mediatek at lists.infradead.org (moderated for non-subscribers)
+S:	Maintained
+F:	Documentation/devicetree/bindings/net/mediatek-bluetooth.txt
+F:	drivers/bluetooth/btmtkuart.c
+
 MEDIATEK CIR DRIVER
 M:	Sean Wang <sean.wang@mediatek.com>
 S:	Maintained
-- 
2.7.4