Message-ID: <f0e0a0b7f1dc3845dc6eafb4ccd60284d1675f8d.1522736996.git.sean.wang@mediatek.com>
Date:   Tue, 3 Apr 2018 15:15:56 +0800
From:   <sean.wang@...iatek.com>
To:     <robh+dt@...nel.org>, <mark.rutland@....com>,
        <marcel@...tmann.org>, <johan.hedberg@...il.com>
CC:     <devicetree@...r.kernel.org>, <linux-bluetooth@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-mediatek@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>, Sean Wang <sean.wang@...iatek.com>
Subject: [PATCH v1 6/7] Bluetooth: hci_mediatek: Add protocol support for MediaTek serial devices

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

This adds a driver for the MediaTek serial protocol based on H4 protocol,
which can enable the built-in Bluetooth device inside MT7622 SoC.

Signed-off-by: Sean Wang <sean.wang@...iatek.com>
---
 drivers/bluetooth/Kconfig        |  12 +
 drivers/bluetooth/Makefile       |   1 +
 drivers/bluetooth/hci_mediatek.c | 499 +++++++++++++++++++++++++++++++++++++++
 drivers/bluetooth/hci_uart.h     |   3 +-
 4 files changed, 514 insertions(+), 1 deletion(-)
 create mode 100644 drivers/bluetooth/hci_mediatek.c

diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig
index 010f5f5..851f430 100644
--- a/drivers/bluetooth/Kconfig
+++ b/drivers/bluetooth/Kconfig
@@ -104,6 +104,18 @@ config BT_HCIUART_H4
 
 	  Say Y here to compile support for HCI UART (H4) protocol.
 
+config BT_HCIUART_MEDIATEK
+	tristate "MediaTek protocol support"
+	depends on BT_HCIUART_SERDEV
+	select BT_HCIUART_H4
+	help
+	  The MediaTek protocol based on H4 enables patch firmware download and
+	  configuration. This protocol is required for MediaTek Bluetooth
+	  devices with a serial bus such as BTIF, which can be usually found on
+	  various MediaTek SoCs.
+
+	  Say Y here to compile support for MediaTek protocol.
+
 config BT_HCIUART_NOKIA
 	tristate "UART Nokia H4+ protocol support"
 	depends on BT_HCIUART
diff --git a/drivers/bluetooth/Makefile b/drivers/bluetooth/Makefile
index ec16c55..db93c76 100644
--- a/drivers/bluetooth/Makefile
+++ b/drivers/bluetooth/Makefile
@@ -43,5 +43,6 @@ hci_uart-$(CONFIG_BT_HCIUART_INTEL)	+= hci_intel.o
 hci_uart-$(CONFIG_BT_HCIUART_BCM)	+= hci_bcm.o
 hci_uart-$(CONFIG_BT_HCIUART_QCA)	+= hci_qca.o
 hci_uart-$(CONFIG_BT_HCIUART_AG6XX)	+= hci_ag6xx.o
+hci_uart-$(CONFIG_BT_HCIUART_MEDIATEK)  += hci_mediatek.o
 hci_uart-$(CONFIG_BT_HCIUART_MRVL)	+= hci_mrvl.o
 hci_uart-objs				:= $(hci_uart-y)
diff --git a/drivers/bluetooth/hci_mediatek.c b/drivers/bluetooth/hci_mediatek.c
new file mode 100644
index 0000000..7ac1e7a
--- /dev/null
+++ b/drivers/bluetooth/hci_mediatek.c
@@ -0,0 +1,499 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2018 MediaTek Inc.
+
+/*
+ * Bluetooth HCI Serial driver for MediaTek SoC
+ *
+ * Author: Sean Wang <sean.wang@...iatek.com>
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/errno.h>
+#include <linux/firmware.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pm_runtime.h>
+#include <linux/unaligned/le_struct.h>
+#include <linux/serdev.h>
+#include <linux/skbuff.h>
+#include <linux/types.h>
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+
+#include "hci_uart.h"
+
+#define FIRMWARE_MT7622		"mediatek/mt7622_patch_firmware.bin"
+
+#define MTK_STP_HDR_SIZE	4
+#define MTK_STP_TLR_SIZE	2
+#define MTK_WMT_HDR_SIZE	5
+#define MTK_WMT_CMD_SIZE	(MTK_WMT_HDR_SIZE + MTK_STP_HDR_SIZE + \
+				 MTK_STP_TLR_SIZE + HCI_ACL_HDR_SIZE)
+
+enum {
+	MTK_WMT_PATCH_DWNLD = 0x1,
+	MTK_WMT_FUNC_CTRL = 0x6,
+	MTK_WMT_RST = 0x7
+};
+
+struct mtk_stp_splitter {
+	u8	pad[6];
+	u8	cursor;
+	u16	dlen;
+};
+
+struct mtk_bt_dev {
+	struct hci_uart hu;
+	struct clk *clk;
+	struct sk_buff *rx_skb;
+	struct sk_buff_head txq;
+	struct completion wmt_cmd;
+	struct mtk_stp_splitter *sp;
+};
+
+struct mtk_stp_hdr {
+	__u8 prefix;
+	__u8 dlen1:4;
+	__u8 type:4;
+	__u8 dlen2:8;
+	__u8 cs;
+} __packed;
+
+struct mtk_wmt_hdr {
+	__u8	dir;
+	__u8	op;
+	__le16	dlen;
+	__u8	flag;
+} __packed;
+
+static void mtk_stp_reset(struct mtk_stp_splitter *sp)
+{
+	sp->cursor = 2;
+	sp->dlen = 0;
+}
+
+static const unsigned char *
+mtk_stp_split(struct device *dev, struct mtk_stp_splitter *sp,
+	      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 being consumed. */
+	if (!sp->dlen && sp->cursor >= 6)
+		sp->cursor = 0;
+
+	/* Filling pad until all STP info is obtained. */
+	while (sp->cursor < 6 && count > 0) {
+		sp->pad[sp->cursor] = *data;
+		sp->cursor++;
+		data++;
+		count--;
+	}
+
+	/* Retrieve STP info and have a sanity check. */
+	if (!sp->dlen && sp->cursor >= 6) {
+		shdr = (struct mtk_stp_hdr *)&sp->pad[2];
+		sp->dlen = shdr->dlen1 << 8 | shdr->dlen2;
+
+		/* Resync STP when unexpected data is being read. */
+		if (shdr->prefix != 0x80 || sp->dlen > 2048) {
+			dev_err(dev, "stp format unexpect (%d, %d)",
+				shdr->prefix, sp->dlen);
+			mtk_stp_reset(sp);
+		}
+	}
+
+	/* Directly leave 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, sp->dlen);
+	/* Update remaining the size of STP packet. */
+	sp->dlen -= *sz_h4;
+
+	/* Data points to STP payload which can be handled by H4. */
+	return data;
+}
+
+static void mtk_stp_hdr_build(struct mtk_stp_hdr *shdr, u8 type, u32 dlen)
+{
+	__u8 *p = (__u8 *)shdr;
+
+	shdr->prefix = 0x80;
+	shdr->dlen1 = (dlen & 0xf00) >> 8;
+	shdr->type = type;
+	shdr->dlen2 = dlen & 0xff;
+	shdr->cs = (p[0] + p[1] + p[2]) & 0xff;
+}
+
+static int mtk_enqueue(struct hci_uart *hu, struct sk_buff *skb)
+{
+	struct mtk_bt_dev *btdev = hu->priv;
+	struct mtk_stp_hdr *shdr;
+	struct sk_buff *new_skb;
+	int dlen;
+
+	memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
+	dlen = skb->len;
+
+	/* Make sure of STP header at least has 4-bytes free space to fill. */
+	if (unlikely(skb_headroom(skb) < MTK_STP_HDR_SIZE)) {
+		new_skb = skb_realloc_headroom(skb, MTK_STP_HDR_SIZE);
+		kfree_skb(skb);
+		skb = new_skb;
+	}
+
+	/* Build for STP packet format. */
+	shdr = skb_push(skb, MTK_STP_HDR_SIZE);
+	mtk_stp_hdr_build(shdr, 0, dlen);
+	skb_put_zero(skb, MTK_STP_TLR_SIZE);
+
+	skb_queue_tail(&btdev->txq, skb);
+
+	return 0;
+}
+
+static int mtk_wmt_cmd_sync(struct hci_uart *hu, u8 opcode, u8 flag, u16 plen,
+			    const void *param)
+{
+	struct mtk_bt_dev *btdev = hu->priv;
+	struct hci_command_hdr *hhdr;
+	struct hci_acl_hdr *ahdr;
+	struct mtk_wmt_hdr *whdr;
+	struct sk_buff *skb;
+	int ret = 0;
+
+	init_completion(&btdev->wmt_cmd);
+
+	skb = bt_skb_alloc(plen + MTK_WMT_CMD_SIZE, GFP_KERNEL);
+	if (!skb)
+		return -ENOMEM;
+
+	/*
+	 * WMT data is carried in either ACL or HCI format with op code as
+	 * 0xfc6f and followed by a WMT header and its actual payload.
+	 */
+	switch (opcode) {
+	case MTK_WMT_PATCH_DWNLD:
+		ahdr = skb_put(skb, HCI_ACL_HDR_SIZE);
+		ahdr->handle = cpu_to_le16(0xfc6f);
+		ahdr->dlen   = cpu_to_le16(plen + MTK_WMT_HDR_SIZE);
+		break;
+	default:
+		hhdr = skb_put(skb, HCI_COMMAND_HDR_SIZE);
+		hhdr->opcode = cpu_to_le16(0xfc6f);
+		hhdr->plen = plen + MTK_WMT_HDR_SIZE;
+		break;
+	}
+
+	hci_skb_pkt_type(skb) = opcode == MTK_WMT_PATCH_DWNLD ?
+				HCI_ACLDATA_PKT : HCI_COMMAND_PKT;
+
+	/* Start to build a WMT header and its actual payload. */
+	whdr = skb_put(skb, MTK_WMT_HDR_SIZE);
+	whdr->dir = 1;
+	whdr->op = opcode;
+	whdr->dlen = cpu_to_le16(plen + 1);
+	whdr->flag = flag;
+	skb_put_data(skb, param, plen);
+
+	mtk_enqueue(hu, skb);
+	hci_uart_tx_wakeup(hu);
+
+	/*
+	 * Waiting a WMT event response, while we must take care in case of
+	 * failures for the wait.
+	 */
+	ret = wait_for_completion_interruptible_timeout(&btdev->wmt_cmd, HZ);
+
+	return ret > 0 ? 0 : ret < 0 ? ret : -ETIMEDOUT;
+}
+
+static int mtk_setup_fw(struct hci_uart *hu)
+{
+	struct mtk_bt_dev *btdev = hu->priv;
+	const struct firmware *fw;
+	struct device *dev;
+	const char *fwname;
+	const u8 *fw_ptr;
+	size_t fw_size;
+	int err, dlen;
+	u8 flag;
+
+	dev = &hu->serdev->dev;
+	fwname = FIRMWARE_MT7622;
+
+	init_completion(&btdev->wmt_cmd);
+
+	err = request_firmware(&fw, fwname, dev);
+	if (err < 0) {
+		dev_err(dev, "%s: Failed to load firmware file (%d)",
+			hu->hdev->name, err);
+		return err;
+	}
+
+	fw_ptr = fw->data;
+	fw_size = fw->size;
+
+	/* The size of a patch header at least has 30 bytes. */
+	if (fw_size < 30)
+		return -EINVAL;
+
+	while (fw_size > 0) {
+		dlen = min_t(int, 1000, fw_size);
+
+		/* Tell deivice the position in sequence. */
+		flag = (fw_size - dlen <= 0) ? 3 :
+		       (fw_size < fw->size) ? 2 : 1;
+
+		err = mtk_wmt_cmd_sync(hu, 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 mtk_open(struct hci_uart *hu)
+{
+	struct mtk_bt_dev *btdev = hu->priv;
+	struct device *dev;
+	int err = 0;
+
+	dev = &hu->serdev->dev;
+
+	serdev_device_open(hu->serdev);
+	skb_queue_head_init(&btdev->txq);
+
+	/* Setup the usage of H4. */
+	hu->alignment = 1;
+	hu->padding = 0;
+	mtk_stp_reset(btdev->sp);
+
+	/* Enable the power domain and clock the device requires */
+	pm_runtime_enable(dev);
+	err = pm_runtime_get_sync(dev);
+	if (err < 0) {
+		pm_runtime_disable(dev);
+		return err;
+	}
+
+	err = clk_prepare_enable(btdev->clk);
+	if (err < 0) {
+		pm_runtime_put_sync(dev);
+		pm_runtime_disable(dev);
+	}
+
+	return err;
+}
+
+static int mtk_close(struct hci_uart *hu)
+{
+	struct mtk_bt_dev *btdev = hu->priv;
+	struct device *dev = &hu->serdev->dev;
+	u8 param = 0x0;
+
+	skb_queue_purge(&btdev->txq);
+	kfree_skb(btdev->rx_skb);
+
+	/* Disable the device. */
+	mtk_wmt_cmd_sync(hu, MTK_WMT_FUNC_CTRL, 0x0, sizeof(param), &param);
+
+	/* Shutdown the clock and power domain the device requires. */
+	clk_disable_unprepare(btdev->clk);
+
+	pm_runtime_put_sync(dev);
+	pm_runtime_disable(dev);
+
+	serdev_device_close(hu->serdev);
+
+	return 0;
+}
+
+int mtk_recv_frame(struct hci_dev *hdev, struct sk_buff *skb)
+{
+	struct hci_event_hdr *hdr = (void *)skb->data;
+	struct hci_uart *hu = hci_get_drvdata(hdev);
+	struct mtk_bt_dev *btdev = hu->priv;
+
+	if (hci_skb_pkt_type(skb) == HCI_EVENT_PKT &&
+	    hdr->evt == 0xe4) {
+		complete(&btdev->wmt_cmd);
+		kfree_skb(skb);
+		return 0;
+	}
+
+	return hci_recv_frame(hdev, skb);
+}
+
+static const struct h4_recv_pkt mtk_recv_pkts[] = {
+	{ H4_RECV_ACL,		.recv = mtk_recv_frame },
+	{ H4_RECV_SCO,		.recv = mtk_recv_frame },
+	{ H4_RECV_EVENT,	.recv = mtk_recv_frame },
+};
+
+static int mtk_recv(struct hci_uart *hu, const void *data, int count)
+{
+	const unsigned char *p_left = data, *p_h4;
+	struct mtk_bt_dev *btdev = hu->priv;
+	int sz_left = count, sz_h4, adv;
+	struct device *dev;
+	int err;
+
+	if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
+		return -EUNATCH;
+
+	dev = &hu->serdev->dev;
+
+	while (sz_left > 0) {
+		p_h4 = mtk_stp_split(dev, btdev->sp, p_left, sz_left, &sz_h4);
+		if (!p_h4)
+			break;
+
+		adv = p_h4 - p_left;
+		sz_left -= adv;
+		p_left += adv;
+
+		btdev->rx_skb = h4_recv_buf(hu->hdev, btdev->rx_skb,
+					    p_h4, sz_h4, mtk_recv_pkts,
+					    ARRAY_SIZE(mtk_recv_pkts));
+		if (IS_ERR(btdev->rx_skb)) {
+			err = PTR_ERR(btdev->rx_skb);
+			dev_err(dev, "Frame reassembly failed (%d)", err);
+			btdev->rx_skb = NULL;
+			return err;
+		}
+
+		sz_left -= sz_h4;
+		p_left += sz_h4;
+	}
+
+	return count;
+}
+
+static struct sk_buff *mtk_dequeue(struct hci_uart *hu)
+{
+	struct mtk_bt_dev *btdev = hu->priv;
+
+	return skb_dequeue(&btdev->txq);
+}
+
+static int mtk_flush(struct hci_uart *hu)
+{
+	struct mtk_bt_dev *btdev = hu->priv;
+
+	skb_queue_purge(&btdev->txq);
+
+	return 0;
+}
+
+static int mtk_setup(struct hci_uart *hu)
+{
+	struct device *dev;
+	u8 param = 0x1;
+	int err;
+
+	dev = &hu->serdev->dev;
+
+	/* Setup a firmware which the device definitely requires. */
+	err = mtk_setup_fw(hu);
+	if (err < 0) {
+		dev_err(dev, "Fail at setup FW (%d): %d", __LINE__, err);
+		return err;
+	}
+
+	/* Activate funciton the firmware provides to. */
+	err = mtk_wmt_cmd_sync(hu, MTK_WMT_RST, 0x4, 0, 0);
+	if (err < 0) {
+		dev_err(dev, "Fail at WMT RST (%d): %d", __LINE__, err);
+		return err;
+	}
+
+	/* Enable Bluetooth protocol. */
+	err = mtk_wmt_cmd_sync(hu, MTK_WMT_FUNC_CTRL, 0x0, sizeof(param),
+			       &param);
+	if (err < 0)
+		dev_err(dev, "Fail at FUNC CTRL (%d): %d", __LINE__, err);
+
+	return err;
+}
+
+static const struct hci_uart_proto mtk_proto = {
+	.id		= HCI_UART_MTK,
+	.name		= "MediaTek",
+	.open		= mtk_open,
+	.close		= mtk_close,
+	.recv		= mtk_recv,
+	.enqueue	= mtk_enqueue,
+	.dequeue	= mtk_dequeue,
+	.flush		= mtk_flush,
+	.setup		= mtk_setup,
+	.manufacturer	= 1,
+};
+
+static int mtk_bluetooth_serdev_probe(struct serdev_device *serdev)
+{
+	struct device *dev = &serdev->dev;
+	struct mtk_bt_dev *btdev;
+	int err = 0;
+
+	btdev = devm_kzalloc(dev, sizeof(*btdev), GFP_KERNEL);
+	if (!btdev)
+		return -ENOMEM;
+
+	btdev->sp = devm_kzalloc(dev, sizeof(*btdev->sp), GFP_KERNEL);
+	if (!btdev->sp)
+		return -ENOMEM;
+
+	btdev->clk = devm_clk_get(dev, "ref");
+	if (IS_ERR(btdev->clk))
+		return PTR_ERR(btdev->clk);
+
+	btdev->hu.serdev = serdev;
+	btdev->hu.priv = btdev;
+
+	serdev_device_set_drvdata(serdev, btdev);
+
+	err = hci_uart_register_device(&btdev->hu, &mtk_proto);
+	if (err)
+		dev_err(dev, "Could not register bluetooth uart: %d", err);
+
+	return err;
+}
+
+static void mtk_bluetooth_serdev_remove(struct serdev_device *serdev)
+{
+	struct mtk_bt_dev *btdev = serdev_device_get_drvdata(serdev);
+
+	hci_uart_unregister_device(&btdev->hu);
+}
+
+static const struct of_device_id mtk_bluetooth_of_match[] = {
+	{ .compatible = "mediatek,mt7622-bluetooth" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mtk_bluetooth_of_match);
+
+static struct serdev_device_driver mtk_bluetooth_serdev_driver = {
+	.probe = mtk_bluetooth_serdev_probe,
+	.remove = mtk_bluetooth_serdev_remove,
+	.driver = {
+		.name = "mediatek-bluetooth",
+		.of_match_table = of_match_ptr(mtk_bluetooth_of_match),
+	},
+};
+
+module_serdev_device_driver(mtk_bluetooth_serdev_driver);
+
+MODULE_AUTHOR("Sean Wang <sean.wang@...iatek.com>");
+MODULE_DESCRIPTION("Bluetooth HCI Serial driver for MediaTek SoC");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/bluetooth/hci_uart.h b/drivers/bluetooth/hci_uart.h
index 66e8c68..3f0911e 100644
--- a/drivers/bluetooth/hci_uart.h
+++ b/drivers/bluetooth/hci_uart.h
@@ -35,7 +35,7 @@
 #define HCIUARTGETFLAGS		_IOR('U', 204, int)
 
 /* UART protocols */
-#define HCI_UART_MAX_PROTO	12
+#define HCI_UART_MAX_PROTO	13
 
 #define HCI_UART_H4	0
 #define HCI_UART_BCSP	1
@@ -49,6 +49,7 @@
 #define HCI_UART_AG6XX	9
 #define HCI_UART_NOKIA	10
 #define HCI_UART_MRVL	11
+#define HCI_UART_MTK	12
 
 #define HCI_UART_RAW_DEVICE	0
 #define HCI_UART_RESET_ON_INIT	1
-- 
2.7.4

Powered by blists - more mailing lists