Adding upstream version 6.1.76.upstream/6.1.76

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

1 files changed, 1135 insertions, 0 deletions

diff --git a/drivers/bluetooth/hci_h5.c b/drivers/bluetooth/hci_h5.c
new file mode 100644
index 000000000..e90670955
--- /dev/null
+++ b/drivers/bluetooth/hci_h5.c
@@ -0,0 +1,1135 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *
+ *  Bluetooth HCI Three-wire UART driver
+ *
+ *  Copyright (C) 2012  Intel Corporation
+ */
+
+#include <linux/acpi.h>
+#include <linux/errno.h>
+#include <linux/gpio/consumer.h>
+#include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
+#include <linux/of_device.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 "btrtl.h"
+#include "hci_uart.h"
+
+#define SUSPEND_TIMEOUT_MS	6000
+
+#define HCI_3WIRE_ACK_PKT	0
+#define HCI_3WIRE_LINK_PKT	15
+
+/* Sliding window size */
+#define H5_TX_WIN_MAX		4
+
+#define H5_ACK_TIMEOUT	msecs_to_jiffies(250)
+#define H5_SYNC_TIMEOUT	msecs_to_jiffies(100)
+
+/*
+ * Maximum Three-wire packet:
+ *     4 byte header + max value for 12-bit length + 2 bytes for CRC
+ */
+#define H5_MAX_LEN (4 + 0xfff + 2)
+
+/* Convenience macros for reading Three-wire header values */
+#define H5_HDR_SEQ(hdr)		((hdr)[0] & 0x07)
+#define H5_HDR_ACK(hdr)		(((hdr)[0] >> 3) & 0x07)
+#define H5_HDR_CRC(hdr)		(((hdr)[0] >> 6) & 0x01)
+#define H5_HDR_RELIABLE(hdr)	(((hdr)[0] >> 7) & 0x01)
+#define H5_HDR_PKT_TYPE(hdr)	((hdr)[1] & 0x0f)
+#define H5_HDR_LEN(hdr)		((((hdr)[1] >> 4) & 0x0f) + ((hdr)[2] << 4))
+
+#define SLIP_DELIMITER	0xc0
+#define SLIP_ESC	0xdb
+#define SLIP_ESC_DELIM	0xdc
+#define SLIP_ESC_ESC	0xdd
+
+/* H5 state flags */
+enum {
+	H5_RX_ESC,		/* SLIP escape mode */
+	H5_TX_ACK_REQ,		/* Pending ack to send */
+	H5_WAKEUP_DISABLE,	/* Device cannot wake host */
+	H5_HW_FLOW_CONTROL,	/* Use HW flow control */
+};
+
+struct h5 {
+	/* Must be the first member, hci_serdev.c expects this. */
+	struct hci_uart		serdev_hu;
+
+	struct sk_buff_head	unack;		/* Unack'ed packets queue */
+	struct sk_buff_head	rel;		/* Reliable packets queue */
+	struct sk_buff_head	unrel;		/* Unreliable packets queue */
+
+	unsigned long		flags;
+
+	struct sk_buff		*rx_skb;	/* Receive buffer */
+	size_t			rx_pending;	/* Expecting more bytes */
+	u8			rx_ack;		/* Last ack number received */
+
+	int			(*rx_func)(struct hci_uart *hu, u8 c);
+
+	struct timer_list	timer;		/* Retransmission timer */
+	struct hci_uart		*hu;		/* Parent HCI UART */
+
+	u8			tx_seq;		/* Next seq number to send */
+	u8			tx_ack;		/* Next ack number to send */
+	u8			tx_win;		/* Sliding window size */
+
+	enum {
+		H5_UNINITIALIZED,
+		H5_INITIALIZED,
+		H5_ACTIVE,
+	} state;
+
+	enum {
+		H5_AWAKE,
+		H5_SLEEPING,
+		H5_WAKING_UP,
+	} sleep;
+
+	const struct h5_vnd *vnd;
+	const char *id;
+
+	struct gpio_desc *enable_gpio;
+	struct gpio_desc *device_wake_gpio;
+};
+
+enum h5_driver_info {
+	H5_INFO_WAKEUP_DISABLE = BIT(0),
+};
+
+struct h5_vnd {
+	int (*setup)(struct h5 *h5);
+	void (*open)(struct h5 *h5);
+	void (*close)(struct h5 *h5);
+	int (*suspend)(struct h5 *h5);
+	int (*resume)(struct h5 *h5);
+	const struct acpi_gpio_mapping *acpi_gpio_map;
+};
+
+struct h5_device_data {
+	uint32_t driver_info;
+	struct h5_vnd *vnd;
+};
+
+static void h5_reset_rx(struct h5 *h5);
+
+static void h5_link_control(struct hci_uart *hu, const void *data, size_t len)
+{
+	struct h5 *h5 = hu->priv;
+	struct sk_buff *nskb;
+
+	nskb = alloc_skb(3, GFP_ATOMIC);
+	if (!nskb)
+		return;
+
+	hci_skb_pkt_type(nskb) = HCI_3WIRE_LINK_PKT;
+
+	skb_put_data(nskb, data, len);
+
+	skb_queue_tail(&h5->unrel, nskb);
+}
+
+static u8 h5_cfg_field(struct h5 *h5)
+{
+	/* Sliding window size (first 3 bits) */
+	return h5->tx_win & 0x07;
+}
+
+static void h5_timed_event(struct timer_list *t)
+{
+	const unsigned char sync_req[] = { 0x01, 0x7e };
+	unsigned char conf_req[3] = { 0x03, 0xfc };
+	struct h5 *h5 = from_timer(h5, t, timer);
+	struct hci_uart *hu = h5->hu;
+	struct sk_buff *skb;
+	unsigned long flags;
+
+	BT_DBG("%s", hu->hdev->name);
+
+	if (h5->state == H5_UNINITIALIZED)
+		h5_link_control(hu, sync_req, sizeof(sync_req));
+
+	if (h5->state == H5_INITIALIZED) {
+		conf_req[2] = h5_cfg_field(h5);
+		h5_link_control(hu, conf_req, sizeof(conf_req));
+	}
+
+	if (h5->state != H5_ACTIVE) {
+		mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT);
+		goto wakeup;
+	}
+
+	if (h5->sleep != H5_AWAKE) {
+		h5->sleep = H5_SLEEPING;
+		goto wakeup;
+	}
+
+	BT_DBG("hu %p retransmitting %u pkts", hu, h5->unack.qlen);
+
+	spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
+
+	while ((skb = __skb_dequeue_tail(&h5->unack)) != NULL) {
+		h5->tx_seq = (h5->tx_seq - 1) & 0x07;
+		skb_queue_head(&h5->rel, skb);
+	}
+
+	spin_unlock_irqrestore(&h5->unack.lock, flags);
+
+wakeup:
+	hci_uart_tx_wakeup(hu);
+}
+
+static void h5_peer_reset(struct hci_uart *hu)
+{
+	struct h5 *h5 = hu->priv;
+
+	bt_dev_err(hu->hdev, "Peer device has reset");
+
+	h5->state = H5_UNINITIALIZED;
+
+	del_timer(&h5->timer);
+
+	skb_queue_purge(&h5->rel);
+	skb_queue_purge(&h5->unrel);
+	skb_queue_purge(&h5->unack);
+
+	h5->tx_seq = 0;
+	h5->tx_ack = 0;
+
+	/* Send reset request to upper stack */
+	hci_reset_dev(hu->hdev);
+}
+
+static int h5_open(struct hci_uart *hu)
+{
+	struct h5 *h5;
+	const unsigned char sync[] = { 0x01, 0x7e };
+
+	BT_DBG("hu %p", hu);
+
+	if (hu->serdev) {
+		h5 = serdev_device_get_drvdata(hu->serdev);
+	} else {
+		h5 = kzalloc(sizeof(*h5), GFP_KERNEL);
+		if (!h5)
+			return -ENOMEM;
+	}
+
+	hu->priv = h5;
+	h5->hu = hu;
+
+	skb_queue_head_init(&h5->unack);
+	skb_queue_head_init(&h5->rel);
+	skb_queue_head_init(&h5->unrel);
+
+	h5_reset_rx(h5);
+
+	timer_setup(&h5->timer, h5_timed_event, 0);
+
+	h5->tx_win = H5_TX_WIN_MAX;
+
+	if (h5->vnd && h5->vnd->open)
+		h5->vnd->open(h5);
+
+	set_bit(HCI_UART_INIT_PENDING, &hu->hdev_flags);
+
+	/* Send initial sync request */
+	h5_link_control(hu, sync, sizeof(sync));
+	mod_timer(&h5->timer, jiffies + H5_SYNC_TIMEOUT);
+
+	return 0;
+}
+
+static int h5_close(struct hci_uart *hu)
+{
+	struct h5 *h5 = hu->priv;
+
+	del_timer_sync(&h5->timer);
+
+	skb_queue_purge(&h5->unack);
+	skb_queue_purge(&h5->rel);
+	skb_queue_purge(&h5->unrel);
+
+	kfree_skb(h5->rx_skb);
+	h5->rx_skb = NULL;
+
+	if (h5->vnd && h5->vnd->close)
+		h5->vnd->close(h5);
+
+	if (!hu->serdev)
+		kfree(h5);
+
+	return 0;
+}
+
+static int h5_setup(struct hci_uart *hu)
+{
+	struct h5 *h5 = hu->priv;
+
+	if (h5->vnd && h5->vnd->setup)
+		return h5->vnd->setup(h5);
+
+	return 0;
+}
+
+static void h5_pkt_cull(struct h5 *h5)
+{
+	struct sk_buff *skb, *tmp;
+	unsigned long flags;
+	int i, to_remove;
+	u8 seq;
+
+	spin_lock_irqsave(&h5->unack.lock, flags);
+
+	to_remove = skb_queue_len(&h5->unack);
+	if (to_remove == 0)
+		goto unlock;
+
+	seq = h5->tx_seq;
+
+	while (to_remove > 0) {
+		if (h5->rx_ack == seq)
+			break;
+
+		to_remove--;
+		seq = (seq - 1) & 0x07;
+	}
+
+	if (seq != h5->rx_ack)
+		BT_ERR("Controller acked invalid packet");
+
+	i = 0;
+	skb_queue_walk_safe(&h5->unack, skb, tmp) {
+		if (i++ >= to_remove)
+			break;
+
+		__skb_unlink(skb, &h5->unack);
+		dev_kfree_skb_irq(skb);
+	}
+
+	if (skb_queue_empty(&h5->unack))
+		del_timer(&h5->timer);
+
+unlock:
+	spin_unlock_irqrestore(&h5->unack.lock, flags);
+}
+
+static void h5_handle_internal_rx(struct hci_uart *hu)
+{
+	struct h5 *h5 = hu->priv;
+	const unsigned char sync_req[] = { 0x01, 0x7e };
+	const unsigned char sync_rsp[] = { 0x02, 0x7d };
+	unsigned char conf_req[3] = { 0x03, 0xfc };
+	const unsigned char conf_rsp[] = { 0x04, 0x7b };
+	const unsigned char wakeup_req[] = { 0x05, 0xfa };
+	const unsigned char woken_req[] = { 0x06, 0xf9 };
+	const unsigned char sleep_req[] = { 0x07, 0x78 };
+	const unsigned char *hdr = h5->rx_skb->data;
+	const unsigned char *data = &h5->rx_skb->data[4];
+
+	BT_DBG("%s", hu->hdev->name);
+
+	if (H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT)
+		return;
+
+	if (H5_HDR_LEN(hdr) < 2)
+		return;
+
+	conf_req[2] = h5_cfg_field(h5);
+
+	if (memcmp(data, sync_req, 2) == 0) {
+		if (h5->state == H5_ACTIVE)
+			h5_peer_reset(hu);
+		h5_link_control(hu, sync_rsp, 2);
+	} else if (memcmp(data, sync_rsp, 2) == 0) {
+		if (h5->state == H5_ACTIVE)
+			h5_peer_reset(hu);
+		h5->state = H5_INITIALIZED;
+		h5_link_control(hu, conf_req, 3);
+	} else if (memcmp(data, conf_req, 2) == 0) {
+		h5_link_control(hu, conf_rsp, 2);
+		h5_link_control(hu, conf_req, 3);
+	} else if (memcmp(data, conf_rsp, 2) == 0) {
+		if (H5_HDR_LEN(hdr) > 2)
+			h5->tx_win = (data[2] & 0x07);
+		BT_DBG("Three-wire init complete. tx_win %u", h5->tx_win);
+		h5->state = H5_ACTIVE;
+		hci_uart_init_ready(hu);
+		return;
+	} else if (memcmp(data, sleep_req, 2) == 0) {
+		BT_DBG("Peer went to sleep");
+		h5->sleep = H5_SLEEPING;
+		return;
+	} else if (memcmp(data, woken_req, 2) == 0) {
+		BT_DBG("Peer woke up");
+		h5->sleep = H5_AWAKE;
+	} else if (memcmp(data, wakeup_req, 2) == 0) {
+		BT_DBG("Peer requested wakeup");
+		h5_link_control(hu, woken_req, 2);
+		h5->sleep = H5_AWAKE;
+	} else {
+		BT_DBG("Link Control: 0x%02hhx 0x%02hhx", data[0], data[1]);
+		return;
+	}
+
+	hci_uart_tx_wakeup(hu);
+}
+
+static void h5_complete_rx_pkt(struct hci_uart *hu)
+{
+	struct h5 *h5 = hu->priv;
+	const unsigned char *hdr = h5->rx_skb->data;
+
+	if (H5_HDR_RELIABLE(hdr)) {
+		h5->tx_ack = (h5->tx_ack + 1) % 8;
+		set_bit(H5_TX_ACK_REQ, &h5->flags);
+		hci_uart_tx_wakeup(hu);
+	}
+
+	h5->rx_ack = H5_HDR_ACK(hdr);
+
+	h5_pkt_cull(h5);
+
+	switch (H5_HDR_PKT_TYPE(hdr)) {
+	case HCI_EVENT_PKT:
+	case HCI_ACLDATA_PKT:
+	case HCI_SCODATA_PKT:
+	case HCI_ISODATA_PKT:
+		hci_skb_pkt_type(h5->rx_skb) = H5_HDR_PKT_TYPE(hdr);
+
+		/* Remove Three-wire header */
+		skb_pull(h5->rx_skb, 4);
+
+		hci_recv_frame(hu->hdev, h5->rx_skb);
+		h5->rx_skb = NULL;
+
+		break;
+
+	default:
+		h5_handle_internal_rx(hu);
+		break;
+	}
+
+	h5_reset_rx(h5);
+}
+
+static int h5_rx_crc(struct hci_uart *hu, unsigned char c)
+{
+	h5_complete_rx_pkt(hu);
+
+	return 0;
+}
+
+static int h5_rx_payload(struct hci_uart *hu, unsigned char c)
+{
+	struct h5 *h5 = hu->priv;
+	const unsigned char *hdr = h5->rx_skb->data;
+
+	if (H5_HDR_CRC(hdr)) {
+		h5->rx_func = h5_rx_crc;
+		h5->rx_pending = 2;
+	} else {
+		h5_complete_rx_pkt(hu);
+	}
+
+	return 0;
+}
+
+static int h5_rx_3wire_hdr(struct hci_uart *hu, unsigned char c)
+{
+	struct h5 *h5 = hu->priv;
+	const unsigned char *hdr = h5->rx_skb->data;
+
+	BT_DBG("%s rx: seq %u ack %u crc %u rel %u type %u len %u",
+	       hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
+	       H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
+	       H5_HDR_LEN(hdr));
+
+	if (((hdr[0] + hdr[1] + hdr[2] + hdr[3]) & 0xff) != 0xff) {
+		bt_dev_err(hu->hdev, "Invalid header checksum");
+		h5_reset_rx(h5);
+		return 0;
+	}
+
+	if (H5_HDR_RELIABLE(hdr) && H5_HDR_SEQ(hdr) != h5->tx_ack) {
+		bt_dev_err(hu->hdev, "Out-of-order packet arrived (%u != %u)",
+			   H5_HDR_SEQ(hdr), h5->tx_ack);
+		h5_reset_rx(h5);
+		return 0;
+	}
+
+	if (h5->state != H5_ACTIVE &&
+	    H5_HDR_PKT_TYPE(hdr) != HCI_3WIRE_LINK_PKT) {
+		bt_dev_err(hu->hdev, "Non-link packet received in non-active state");
+		h5_reset_rx(h5);
+		return 0;
+	}
+
+	h5->rx_func = h5_rx_payload;
+	h5->rx_pending = H5_HDR_LEN(hdr);
+
+	return 0;
+}
+
+static int h5_rx_pkt_start(struct hci_uart *hu, unsigned char c)
+{
+	struct h5 *h5 = hu->priv;
+
+	if (c == SLIP_DELIMITER)
+		return 1;
+
+	h5->rx_func = h5_rx_3wire_hdr;
+	h5->rx_pending = 4;
+
+	h5->rx_skb = bt_skb_alloc(H5_MAX_LEN, GFP_ATOMIC);
+	if (!h5->rx_skb) {
+		bt_dev_err(hu->hdev, "Can't allocate mem for new packet");
+		h5_reset_rx(h5);
+		return -ENOMEM;
+	}
+
+	h5->rx_skb->dev = (void *)hu->hdev;
+
+	return 0;
+}
+
+static int h5_rx_delimiter(struct hci_uart *hu, unsigned char c)
+{
+	struct h5 *h5 = hu->priv;
+
+	if (c == SLIP_DELIMITER)
+		h5->rx_func = h5_rx_pkt_start;
+
+	return 1;
+}
+
+static void h5_unslip_one_byte(struct h5 *h5, unsigned char c)
+{
+	const u8 delim = SLIP_DELIMITER, esc = SLIP_ESC;
+	const u8 *byte = &c;
+
+	if (!test_bit(H5_RX_ESC, &h5->flags) && c == SLIP_ESC) {
+		set_bit(H5_RX_ESC, &h5->flags);
+		return;
+	}
+
+	if (test_and_clear_bit(H5_RX_ESC, &h5->flags)) {
+		switch (c) {
+		case SLIP_ESC_DELIM:
+			byte = &delim;
+			break;
+		case SLIP_ESC_ESC:
+			byte = &esc;
+			break;
+		default:
+			BT_ERR("Invalid esc byte 0x%02hhx", c);
+			h5_reset_rx(h5);
+			return;
+		}
+	}
+
+	skb_put_data(h5->rx_skb, byte, 1);
+	h5->rx_pending--;
+
+	BT_DBG("unslipped 0x%02hhx, rx_pending %zu", *byte, h5->rx_pending);
+}
+
+static void h5_reset_rx(struct h5 *h5)
+{
+	if (h5->rx_skb) {
+		kfree_skb(h5->rx_skb);
+		h5->rx_skb = NULL;
+	}
+
+	h5->rx_func = h5_rx_delimiter;
+	h5->rx_pending = 0;
+	clear_bit(H5_RX_ESC, &h5->flags);
+}
+
+static int h5_recv(struct hci_uart *hu, const void *data, int count)
+{
+	struct h5 *h5 = hu->priv;
+	const unsigned char *ptr = data;
+
+	BT_DBG("%s pending %zu count %d", hu->hdev->name, h5->rx_pending,
+	       count);
+
+	while (count > 0) {
+		int processed;
+
+		if (h5->rx_pending > 0) {
+			if (*ptr == SLIP_DELIMITER) {
+				bt_dev_err(hu->hdev, "Too short H5 packet");
+				h5_reset_rx(h5);
+				continue;
+			}
+
+			h5_unslip_one_byte(h5, *ptr);
+
+			ptr++; count--;
+			continue;
+		}
+
+		processed = h5->rx_func(hu, *ptr);
+		if (processed < 0)
+			return processed;
+
+		ptr += processed;
+		count -= processed;
+	}
+
+	if (hu->serdev) {
+		pm_runtime_get(&hu->serdev->dev);
+		pm_runtime_mark_last_busy(&hu->serdev->dev);
+		pm_runtime_put_autosuspend(&hu->serdev->dev);
+	}
+
+	return 0;
+}
+
+static int h5_enqueue(struct hci_uart *hu, struct sk_buff *skb)
+{
+	struct h5 *h5 = hu->priv;
+
+	if (skb->len > 0xfff) {
+		bt_dev_err(hu->hdev, "Packet too long (%u bytes)", skb->len);
+		kfree_skb(skb);
+		return 0;
+	}
+
+	if (h5->state != H5_ACTIVE) {
+		bt_dev_err(hu->hdev, "Ignoring HCI data in non-active state");
+		kfree_skb(skb);
+		return 0;
+	}
+
+	switch (hci_skb_pkt_type(skb)) {
+	case HCI_ACLDATA_PKT:
+	case HCI_COMMAND_PKT:
+		skb_queue_tail(&h5->rel, skb);
+		break;
+
+	case HCI_SCODATA_PKT:
+	case HCI_ISODATA_PKT:
+		skb_queue_tail(&h5->unrel, skb);
+		break;
+
+	default:
+		bt_dev_err(hu->hdev, "Unknown packet type %u", hci_skb_pkt_type(skb));
+		kfree_skb(skb);
+		break;
+	}
+
+	if (hu->serdev) {
+		pm_runtime_get_sync(&hu->serdev->dev);
+		pm_runtime_mark_last_busy(&hu->serdev->dev);
+		pm_runtime_put_autosuspend(&hu->serdev->dev);
+	}
+
+	return 0;
+}
+
+static void h5_slip_delim(struct sk_buff *skb)
+{
+	const char delim = SLIP_DELIMITER;
+
+	skb_put_data(skb, &delim, 1);
+}
+
+static void h5_slip_one_byte(struct sk_buff *skb, u8 c)
+{
+	const char esc_delim[2] = { SLIP_ESC, SLIP_ESC_DELIM };
+	const char esc_esc[2] = { SLIP_ESC, SLIP_ESC_ESC };
+
+	switch (c) {
+	case SLIP_DELIMITER:
+		skb_put_data(skb, &esc_delim, 2);
+		break;
+	case SLIP_ESC:
+		skb_put_data(skb, &esc_esc, 2);
+		break;
+	default:
+		skb_put_data(skb, &c, 1);
+	}
+}
+
+static bool valid_packet_type(u8 type)
+{
+	switch (type) {
+	case HCI_ACLDATA_PKT:
+	case HCI_COMMAND_PKT:
+	case HCI_SCODATA_PKT:
+	case HCI_ISODATA_PKT:
+	case HCI_3WIRE_LINK_PKT:
+	case HCI_3WIRE_ACK_PKT:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static struct sk_buff *h5_prepare_pkt(struct hci_uart *hu, u8 pkt_type,
+				      const u8 *data, size_t len)
+{
+	struct h5 *h5 = hu->priv;
+	struct sk_buff *nskb;
+	u8 hdr[4];
+	int i;
+
+	if (!valid_packet_type(pkt_type)) {
+		bt_dev_err(hu->hdev, "Unknown packet type %u", pkt_type);
+		return NULL;
+	}
+
+	/*
+	 * Max len of packet: (original len + 4 (H5 hdr) + 2 (crc)) * 2
+	 * (because bytes 0xc0 and 0xdb are escaped, worst case is when
+	 * the packet is all made of 0xc0 and 0xdb) + 2 (0xc0
+	 * delimiters at start and end).
+	 */
+	nskb = alloc_skb((len + 6) * 2 + 2, GFP_ATOMIC);
+	if (!nskb)
+		return NULL;
+
+	hci_skb_pkt_type(nskb) = pkt_type;
+
+	h5_slip_delim(nskb);
+
+	hdr[0] = h5->tx_ack << 3;
+	clear_bit(H5_TX_ACK_REQ, &h5->flags);
+
+	/* Reliable packet? */
+	if (pkt_type == HCI_ACLDATA_PKT || pkt_type == HCI_COMMAND_PKT) {
+		hdr[0] |= 1 << 7;
+		hdr[0] |= h5->tx_seq;
+		h5->tx_seq = (h5->tx_seq + 1) % 8;
+	}
+
+	hdr[1] = pkt_type | ((len & 0x0f) << 4);
+	hdr[2] = len >> 4;
+	hdr[3] = ~((hdr[0] + hdr[1] + hdr[2]) & 0xff);
+
+	BT_DBG("%s tx: seq %u ack %u crc %u rel %u type %u len %u",
+	       hu->hdev->name, H5_HDR_SEQ(hdr), H5_HDR_ACK(hdr),
+	       H5_HDR_CRC(hdr), H5_HDR_RELIABLE(hdr), H5_HDR_PKT_TYPE(hdr),
+	       H5_HDR_LEN(hdr));
+
+	for (i = 0; i < 4; i++)
+		h5_slip_one_byte(nskb, hdr[i]);
+
+	for (i = 0; i < len; i++)
+		h5_slip_one_byte(nskb, data[i]);
+
+	h5_slip_delim(nskb);
+
+	return nskb;
+}
+
+static struct sk_buff *h5_dequeue(struct hci_uart *hu)
+{
+	struct h5 *h5 = hu->priv;
+	unsigned long flags;
+	struct sk_buff *skb, *nskb;
+
+	if (h5->sleep != H5_AWAKE) {
+		const unsigned char wakeup_req[] = { 0x05, 0xfa };
+
+		if (h5->sleep == H5_WAKING_UP)
+			return NULL;
+
+		h5->sleep = H5_WAKING_UP;
+		BT_DBG("Sending wakeup request");
+
+		mod_timer(&h5->timer, jiffies + HZ / 100);
+		return h5_prepare_pkt(hu, HCI_3WIRE_LINK_PKT, wakeup_req, 2);
+	}
+
+	skb = skb_dequeue(&h5->unrel);
+	if (skb) {
+		nskb = h5_prepare_pkt(hu, hci_skb_pkt_type(skb),
+				      skb->data, skb->len);
+		if (nskb) {
+			kfree_skb(skb);
+			return nskb;
+		}
+
+		skb_queue_head(&h5->unrel, skb);
+		bt_dev_err(hu->hdev, "Could not dequeue pkt because alloc_skb failed");
+	}
+
+	spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
+
+	if (h5->unack.qlen >= h5->tx_win)
+		goto unlock;
+
+	skb = skb_dequeue(&h5->rel);
+	if (skb) {
+		nskb = h5_prepare_pkt(hu, hci_skb_pkt_type(skb),
+				      skb->data, skb->len);
+		if (nskb) {
+			__skb_queue_tail(&h5->unack, skb);
+			mod_timer(&h5->timer, jiffies + H5_ACK_TIMEOUT);
+			spin_unlock_irqrestore(&h5->unack.lock, flags);
+			return nskb;
+		}
+
+		skb_queue_head(&h5->rel, skb);
+		bt_dev_err(hu->hdev, "Could not dequeue pkt because alloc_skb failed");
+	}
+
+unlock:
+	spin_unlock_irqrestore(&h5->unack.lock, flags);
+
+	if (test_bit(H5_TX_ACK_REQ, &h5->flags))
+		return h5_prepare_pkt(hu, HCI_3WIRE_ACK_PKT, NULL, 0);
+
+	return NULL;
+}
+
+static int h5_flush(struct hci_uart *hu)
+{
+	BT_DBG("hu %p", hu);
+	return 0;
+}
+
+static const struct hci_uart_proto h5p = {
+	.id		= HCI_UART_3WIRE,
+	.name		= "Three-wire (H5)",
+	.open		= h5_open,
+	.close		= h5_close,
+	.setup		= h5_setup,
+	.recv		= h5_recv,
+	.enqueue	= h5_enqueue,
+	.dequeue	= h5_dequeue,
+	.flush		= h5_flush,
+};
+
+static int h5_serdev_probe(struct serdev_device *serdev)
+{
+	struct device *dev = &serdev->dev;
+	struct h5 *h5;
+	const struct h5_device_data *data;
+
+	h5 = devm_kzalloc(dev, sizeof(*h5), GFP_KERNEL);
+	if (!h5)
+		return -ENOMEM;
+
+	h5->hu = &h5->serdev_hu;
+	h5->serdev_hu.serdev = serdev;
+	serdev_device_set_drvdata(serdev, h5);
+
+	if (has_acpi_companion(dev)) {
+		const struct acpi_device_id *match;
+
+		match = acpi_match_device(dev->driver->acpi_match_table, dev);
+		if (!match)
+			return -ENODEV;
+
+		data = (const struct h5_device_data *)match->driver_data;
+		h5->vnd = data->vnd;
+		h5->id  = (char *)match->id;
+
+		if (h5->vnd->acpi_gpio_map)
+			devm_acpi_dev_add_driver_gpios(dev,
+						       h5->vnd->acpi_gpio_map);
+	} else {
+		data = of_device_get_match_data(dev);
+		if (!data)
+			return -ENODEV;
+
+		h5->vnd = data->vnd;
+	}
+
+	if (data->driver_info & H5_INFO_WAKEUP_DISABLE)
+		set_bit(H5_WAKEUP_DISABLE, &h5->flags);
+
+	h5->enable_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW);
+	if (IS_ERR(h5->enable_gpio))
+		return PTR_ERR(h5->enable_gpio);
+
+	h5->device_wake_gpio = devm_gpiod_get_optional(dev, "device-wake",
+						       GPIOD_OUT_LOW);
+	if (IS_ERR(h5->device_wake_gpio))
+		return PTR_ERR(h5->device_wake_gpio);
+
+	return hci_uart_register_device(&h5->serdev_hu, &h5p);
+}
+
+static void h5_serdev_remove(struct serdev_device *serdev)
+{
+	struct h5 *h5 = serdev_device_get_drvdata(serdev);
+
+	hci_uart_unregister_device(&h5->serdev_hu);
+}
+
+static int __maybe_unused h5_serdev_suspend(struct device *dev)
+{
+	struct h5 *h5 = dev_get_drvdata(dev);
+	int ret = 0;
+
+	if (h5->vnd && h5->vnd->suspend)
+		ret = h5->vnd->suspend(h5);
+
+	return ret;
+}
+
+static int __maybe_unused h5_serdev_resume(struct device *dev)
+{
+	struct h5 *h5 = dev_get_drvdata(dev);
+	int ret = 0;
+
+	if (h5->vnd && h5->vnd->resume)
+		ret = h5->vnd->resume(h5);
+
+	return ret;
+}
+
+#ifdef CONFIG_BT_HCIUART_RTL
+static int h5_btrtl_setup(struct h5 *h5)
+{
+	struct btrtl_device_info *btrtl_dev;
+	struct sk_buff *skb;
+	__le32 baudrate_data;
+	u32 device_baudrate;
+	unsigned int controller_baudrate;
+	bool flow_control;
+	int err;
+
+	btrtl_dev = btrtl_initialize(h5->hu->hdev, h5->id);
+	if (IS_ERR(btrtl_dev))
+		return PTR_ERR(btrtl_dev);
+
+	err = btrtl_get_uart_settings(h5->hu->hdev, btrtl_dev,
+				      &controller_baudrate, &device_baudrate,
+				      &flow_control);
+	if (err)
+		goto out_free;
+
+	baudrate_data = cpu_to_le32(device_baudrate);
+	skb = __hci_cmd_sync(h5->hu->hdev, 0xfc17, sizeof(baudrate_data),
+			     &baudrate_data, HCI_INIT_TIMEOUT);
+	if (IS_ERR(skb)) {
+		rtl_dev_err(h5->hu->hdev, "set baud rate command failed\n");
+		err = PTR_ERR(skb);
+		goto out_free;
+	} else {
+		kfree_skb(skb);
+	}
+	/* Give the device some time to set up the new baudrate. */
+	usleep_range(10000, 20000);
+
+	serdev_device_set_baudrate(h5->hu->serdev, controller_baudrate);
+	serdev_device_set_flow_control(h5->hu->serdev, flow_control);
+
+	if (flow_control)
+		set_bit(H5_HW_FLOW_CONTROL, &h5->flags);
+
+	err = btrtl_download_firmware(h5->hu->hdev, btrtl_dev);
+	/* Give the device some time before the hci-core sends it a reset */
+	usleep_range(10000, 20000);
+	if (err)
+		goto out_free;
+
+	btrtl_set_quirks(h5->hu->hdev, btrtl_dev);
+
+out_free:
+	btrtl_free(btrtl_dev);
+
+	return err;
+}
+
+static void h5_btrtl_open(struct h5 *h5)
+{
+	/*
+	 * Since h5_btrtl_resume() does a device_reprobe() the suspend handling
+	 * done by the hci_suspend_notifier is not necessary; it actually causes
+	 * delays and a bunch of errors to get logged, so disable it.
+	 */
+	if (test_bit(H5_WAKEUP_DISABLE, &h5->flags))
+		set_bit(HCI_UART_NO_SUSPEND_NOTIFIER, &h5->hu->flags);
+
+	/* Devices always start with these fixed parameters */
+	serdev_device_set_flow_control(h5->hu->serdev, false);
+	serdev_device_set_parity(h5->hu->serdev, SERDEV_PARITY_EVEN);
+	serdev_device_set_baudrate(h5->hu->serdev, 115200);
+
+	if (!test_bit(H5_WAKEUP_DISABLE, &h5->flags)) {
+		pm_runtime_set_active(&h5->hu->serdev->dev);
+		pm_runtime_use_autosuspend(&h5->hu->serdev->dev);
+		pm_runtime_set_autosuspend_delay(&h5->hu->serdev->dev,
+						 SUSPEND_TIMEOUT_MS);
+		pm_runtime_enable(&h5->hu->serdev->dev);
+	}
+
+	/* The controller needs reset to startup */
+	gpiod_set_value_cansleep(h5->enable_gpio, 0);
+	gpiod_set_value_cansleep(h5->device_wake_gpio, 0);
+	msleep(100);
+
+	/* The controller needs up to 500ms to wakeup */
+	gpiod_set_value_cansleep(h5->enable_gpio, 1);
+	gpiod_set_value_cansleep(h5->device_wake_gpio, 1);
+	msleep(500);
+}
+
+static void h5_btrtl_close(struct h5 *h5)
+{
+	if (!test_bit(H5_WAKEUP_DISABLE, &h5->flags))
+		pm_runtime_disable(&h5->hu->serdev->dev);
+
+	gpiod_set_value_cansleep(h5->device_wake_gpio, 0);
+	gpiod_set_value_cansleep(h5->enable_gpio, 0);
+}
+
+/* Suspend/resume support. On many devices the RTL BT device loses power during
+ * suspend/resume, causing it to lose its firmware and all state. So we simply
+ * turn it off on suspend and reprobe on resume. This mirrors how RTL devices
+ * are handled in the USB driver, where the BTUSB_WAKEUP_DISABLE is used which
+ * also causes a reprobe on resume.
+ */
+static int h5_btrtl_suspend(struct h5 *h5)
+{
+	serdev_device_set_flow_control(h5->hu->serdev, false);
+	gpiod_set_value_cansleep(h5->device_wake_gpio, 0);
+
+	if (test_bit(H5_WAKEUP_DISABLE, &h5->flags))
+		gpiod_set_value_cansleep(h5->enable_gpio, 0);
+
+	return 0;
+}
+
+struct h5_btrtl_reprobe {
+	struct device *dev;
+	struct work_struct work;
+};
+
+static void h5_btrtl_reprobe_worker(struct work_struct *work)
+{
+	struct h5_btrtl_reprobe *reprobe =
+		container_of(work, struct h5_btrtl_reprobe, work);
+	int ret;
+
+	ret = device_reprobe(reprobe->dev);
+	if (ret && ret != -EPROBE_DEFER)
+		dev_err(reprobe->dev, "Reprobe error %d\n", ret);
+
+	put_device(reprobe->dev);
+	kfree(reprobe);
+	module_put(THIS_MODULE);
+}
+
+static int h5_btrtl_resume(struct h5 *h5)
+{
+	if (test_bit(H5_WAKEUP_DISABLE, &h5->flags)) {
+		struct h5_btrtl_reprobe *reprobe;
+
+		reprobe = kzalloc(sizeof(*reprobe), GFP_KERNEL);
+		if (!reprobe)
+			return -ENOMEM;
+
+		__module_get(THIS_MODULE);
+
+		INIT_WORK(&reprobe->work, h5_btrtl_reprobe_worker);
+		reprobe->dev = get_device(&h5->hu->serdev->dev);
+		queue_work(system_long_wq, &reprobe->work);
+	} else {
+		gpiod_set_value_cansleep(h5->device_wake_gpio, 1);
+
+		if (test_bit(H5_HW_FLOW_CONTROL, &h5->flags))
+			serdev_device_set_flow_control(h5->hu->serdev, true);
+	}
+
+	return 0;
+}
+
+static const struct acpi_gpio_params btrtl_device_wake_gpios = { 0, 0, false };
+static const struct acpi_gpio_params btrtl_enable_gpios = { 1, 0, false };
+static const struct acpi_gpio_params btrtl_host_wake_gpios = { 2, 0, false };
+static const struct acpi_gpio_mapping acpi_btrtl_gpios[] = {
+	{ "device-wake-gpios", &btrtl_device_wake_gpios, 1 },
+	{ "enable-gpios", &btrtl_enable_gpios, 1 },
+	{ "host-wake-gpios", &btrtl_host_wake_gpios, 1 },
+	{},
+};
+
+static struct h5_vnd rtl_vnd = {
+	.setup		= h5_btrtl_setup,
+	.open		= h5_btrtl_open,
+	.close		= h5_btrtl_close,
+	.suspend	= h5_btrtl_suspend,
+	.resume		= h5_btrtl_resume,
+	.acpi_gpio_map	= acpi_btrtl_gpios,
+};
+
+static const struct h5_device_data h5_data_rtl8822cs = {
+	.vnd = &rtl_vnd,
+};
+
+static const struct h5_device_data h5_data_rtl8723bs = {
+	.driver_info = H5_INFO_WAKEUP_DISABLE,
+	.vnd = &rtl_vnd,
+};
+#endif
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id h5_acpi_match[] = {
+#ifdef CONFIG_BT_HCIUART_RTL
+	{ "OBDA0623", (kernel_ulong_t)&h5_data_rtl8723bs },
+	{ "OBDA8723", (kernel_ulong_t)&h5_data_rtl8723bs },
+#endif
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, h5_acpi_match);
+#endif
+
+static const struct dev_pm_ops h5_serdev_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(h5_serdev_suspend, h5_serdev_resume)
+	SET_RUNTIME_PM_OPS(h5_serdev_suspend, h5_serdev_resume, NULL)
+};
+
+static const struct of_device_id rtl_bluetooth_of_match[] = {
+#ifdef CONFIG_BT_HCIUART_RTL
+	{ .compatible = "realtek,rtl8822cs-bt",
+	  .data = (const void *)&h5_data_rtl8822cs },
+	{ .compatible = "realtek,rtl8723bs-bt",
+	  .data = (const void *)&h5_data_rtl8723bs },
+	{ .compatible = "realtek,rtl8723cs-bt",
+	  .data = (const void *)&h5_data_rtl8723bs },
+	{ .compatible = "realtek,rtl8723ds-bt",
+	  .data = (const void *)&h5_data_rtl8723bs },
+#endif
+	{ },
+};
+MODULE_DEVICE_TABLE(of, rtl_bluetooth_of_match);
+
+static struct serdev_device_driver h5_serdev_driver = {
+	.probe = h5_serdev_probe,
+	.remove = h5_serdev_remove,
+	.driver = {
+		.name = "hci_uart_h5",
+		.acpi_match_table = ACPI_PTR(h5_acpi_match),
+		.pm = &h5_serdev_pm_ops,
+		.of_match_table = rtl_bluetooth_of_match,
+	},
+};
+
+int __init h5_init(void)
+{
+	serdev_device_driver_register(&h5_serdev_driver);
+	return hci_uart_register_proto(&h5p);
+}
+
+int __exit h5_deinit(void)
+{
+	serdev_device_driver_unregister(&h5_serdev_driver);
+	return hci_uart_unregister_proto(&h5p);
+}