Merge tag 'trace-v5.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt...

[linux/fpc-iii.git] / drivers / bluetooth / hci_ll.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Texas Instruments' Bluetooth HCILL UART protocol
 *
 *  HCILL (HCI Low Level) is a Texas Instruments' power management
 *  protocol extension to H4.
 *
 *  Copyright (C) 2007 Texas Instruments, Inc.
 *
 *  Written by Ohad Ben-Cohen <ohad@bencohen.org>
 *
 *  Acknowledgements:
 *  This file is based on hci_h4.c, which was written
 *  by Maxim Krasnyansky and Marcel Holtmann.
 */

#include <linux/module.h>
#include <linux/kernel.h>

#include <linux/init.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/firmware.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/poll.h>

#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/signal.h>
#include <linux/ioctl.h>
#include <linux/of.h>
#include <linux/serdev.h>
#include <linux/skbuff.h>
#include <linux/ti_wilink_st.h>
#include <linux/clk.h>

#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
#include <linux/gpio/consumer.h>
#include <linux/nvmem-consumer.h>

#include "hci_uart.h"

/* Vendor-specific HCI commands */
#define HCI_VS_WRITE_BD_ADDR                    0xfc06
#define HCI_VS_UPDATE_UART_HCI_BAUDRATE         0xff36

/* HCILL commands */
#define HCILL_GO_TO_SLEEP_IND   0x30
#define HCILL_GO_TO_SLEEP_ACK   0x31
#define HCILL_WAKE_UP_IND       0x32
#define HCILL_WAKE_UP_ACK       0x33

/* HCILL states */
enum hcill_states_e {
        HCILL_ASLEEP,
        HCILL_ASLEEP_TO_AWAKE,
        HCILL_AWAKE,
        HCILL_AWAKE_TO_ASLEEP
};

struct ll_device {
        struct hci_uart hu;
        struct serdev_device *serdev;
        struct gpio_desc *enable_gpio;
        struct clk *ext_clk;
        bdaddr_t bdaddr;
};

struct ll_struct {
        struct sk_buff *rx_skb;
        struct sk_buff_head txq;
        spinlock_t hcill_lock;          /* HCILL state lock     */
        unsigned long hcill_state;      /* HCILL power state    */
        struct sk_buff_head tx_wait_q;  /* HCILL wait queue     */
};

/*
 * Builds and sends an HCILL command packet.
 * These are very simple packets with only 1 cmd byte
 */
static int send_hcill_cmd(u8 cmd, struct hci_uart *hu)
{
        int err = 0;
        struct sk_buff *skb = NULL;
        struct ll_struct *ll = hu->priv;

        BT_DBG("hu %p cmd 0x%x", hu, cmd);

        /* allocate packet */
        skb = bt_skb_alloc(1, GFP_ATOMIC);
        if (!skb) {
                BT_ERR("cannot allocate memory for HCILL packet");
                err = -ENOMEM;
                goto out;
        }

        /* prepare packet */
        skb_put_u8(skb, cmd);

        /* send packet */
        skb_queue_tail(&ll->txq, skb);
out:
        return err;
}

/* Initialize protocol */
static int ll_open(struct hci_uart *hu)
{
        struct ll_struct *ll;

        BT_DBG("hu %p", hu);

        ll = kzalloc(sizeof(*ll), GFP_KERNEL);
        if (!ll)
                return -ENOMEM;

        skb_queue_head_init(&ll->txq);
        skb_queue_head_init(&ll->tx_wait_q);
        spin_lock_init(&ll->hcill_lock);

        ll->hcill_state = HCILL_AWAKE;

        hu->priv = ll;

        if (hu->serdev) {
                struct ll_device *lldev = serdev_device_get_drvdata(hu->serdev);

                if (!IS_ERR(lldev->ext_clk))
                        clk_prepare_enable(lldev->ext_clk);
        }

        return 0;
}

/* Flush protocol data */
static int ll_flush(struct hci_uart *hu)
{
        struct ll_struct *ll = hu->priv;

        BT_DBG("hu %p", hu);

        skb_queue_purge(&ll->tx_wait_q);
        skb_queue_purge(&ll->txq);

        return 0;
}

/* Close protocol */
static int ll_close(struct hci_uart *hu)
{
        struct ll_struct *ll = hu->priv;

        BT_DBG("hu %p", hu);

        skb_queue_purge(&ll->tx_wait_q);
        skb_queue_purge(&ll->txq);

        kfree_skb(ll->rx_skb);

        if (hu->serdev) {
                struct ll_device *lldev = serdev_device_get_drvdata(hu->serdev);

                gpiod_set_value_cansleep(lldev->enable_gpio, 0);

                clk_disable_unprepare(lldev->ext_clk);
        }

        hu->priv = NULL;

        kfree(ll);

        return 0;
}

/*
 * internal function, which does common work of the device wake up process:
 * 1. places all pending packets (waiting in tx_wait_q list) in txq list.
 * 2. changes internal state to HCILL_AWAKE.
 * Note: assumes that hcill_lock spinlock is taken,
 * shouldn't be called otherwise!
 */
static void __ll_do_awake(struct ll_struct *ll)
{
        struct sk_buff *skb = NULL;

        while ((skb = skb_dequeue(&ll->tx_wait_q)))
                skb_queue_tail(&ll->txq, skb);

        ll->hcill_state = HCILL_AWAKE;
}

/*
 * Called upon a wake-up-indication from the device
 */
static void ll_device_want_to_wakeup(struct hci_uart *hu)
{
        unsigned long flags;
        struct ll_struct *ll = hu->priv;

        BT_DBG("hu %p", hu);

        /* lock hcill state */
        spin_lock_irqsave(&ll->hcill_lock, flags);

        switch (ll->hcill_state) {
        case HCILL_ASLEEP_TO_AWAKE:
                /*
                 * This state means that both the host and the BRF chip
                 * have simultaneously sent a wake-up-indication packet.
                 * Traditionally, in this case, receiving a wake-up-indication
                 * was enough and an additional wake-up-ack wasn't needed.
                 * This has changed with the BRF6350, which does require an
                 * explicit wake-up-ack. Other BRF versions, which do not
                 * require an explicit ack here, do accept it, thus it is
                 * perfectly safe to always send one.
                 */
                BT_DBG("dual wake-up-indication");
                fallthrough;
        case HCILL_ASLEEP:
                /* acknowledge device wake up */
                if (send_hcill_cmd(HCILL_WAKE_UP_ACK, hu) < 0) {
                        BT_ERR("cannot acknowledge device wake up");
                        goto out;
                }
                break;
        default:
                /* any other state is illegal */
                BT_ERR("received HCILL_WAKE_UP_IND in state %ld",
                       ll->hcill_state);
                break;
        }

        /* send pending packets and change state to HCILL_AWAKE */
        __ll_do_awake(ll);

out:
        spin_unlock_irqrestore(&ll->hcill_lock, flags);

        /* actually send the packets */
        hci_uart_tx_wakeup(hu);
}

/*
 * Called upon a sleep-indication from the device
 */
static void ll_device_want_to_sleep(struct hci_uart *hu)
{
        unsigned long flags;
        struct ll_struct *ll = hu->priv;

        BT_DBG("hu %p", hu);

        /* lock hcill state */
        spin_lock_irqsave(&ll->hcill_lock, flags);

        /* sanity check */
        if (ll->hcill_state != HCILL_AWAKE)
                BT_ERR("ERR: HCILL_GO_TO_SLEEP_IND in state %ld",
                       ll->hcill_state);

        /* acknowledge device sleep */
        if (send_hcill_cmd(HCILL_GO_TO_SLEEP_ACK, hu) < 0) {
                BT_ERR("cannot acknowledge device sleep");
                goto out;
        }

        /* update state */
        ll->hcill_state = HCILL_ASLEEP;

out:
        spin_unlock_irqrestore(&ll->hcill_lock, flags);

        /* actually send the sleep ack packet */
        hci_uart_tx_wakeup(hu);
}

/*
 * Called upon wake-up-acknowledgement from the device
 */
static void ll_device_woke_up(struct hci_uart *hu)
{
        unsigned long flags;
        struct ll_struct *ll = hu->priv;

        BT_DBG("hu %p", hu);

        /* lock hcill state */
        spin_lock_irqsave(&ll->hcill_lock, flags);

        /* sanity check */
        if (ll->hcill_state != HCILL_ASLEEP_TO_AWAKE)
                BT_ERR("received HCILL_WAKE_UP_ACK in state %ld",
                       ll->hcill_state);

        /* send pending packets and change state to HCILL_AWAKE */
        __ll_do_awake(ll);

        spin_unlock_irqrestore(&ll->hcill_lock, flags);

        /* actually send the packets */
        hci_uart_tx_wakeup(hu);
}

/* Enqueue frame for transmittion (padding, crc, etc) */
/* may be called from two simultaneous tasklets */
static int ll_enqueue(struct hci_uart *hu, struct sk_buff *skb)
{
        unsigned long flags = 0;
        struct ll_struct *ll = hu->priv;

        BT_DBG("hu %p skb %p", hu, skb);

        /* Prepend skb with frame type */
        memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);

        /* lock hcill state */
        spin_lock_irqsave(&ll->hcill_lock, flags);

        /* act according to current state */
        switch (ll->hcill_state) {
        case HCILL_AWAKE:
                BT_DBG("device awake, sending normally");
                skb_queue_tail(&ll->txq, skb);
                break;
        case HCILL_ASLEEP:
                BT_DBG("device asleep, waking up and queueing packet");
                /* save packet for later */
                skb_queue_tail(&ll->tx_wait_q, skb);
                /* awake device */
                if (send_hcill_cmd(HCILL_WAKE_UP_IND, hu) < 0) {
                        BT_ERR("cannot wake up device");
                        break;
                }
                ll->hcill_state = HCILL_ASLEEP_TO_AWAKE;
                break;
        case HCILL_ASLEEP_TO_AWAKE:
                BT_DBG("device waking up, queueing packet");
                /* transient state; just keep packet for later */
                skb_queue_tail(&ll->tx_wait_q, skb);
                break;
        default:
                BT_ERR("illegal hcill state: %ld (losing packet)",
                       ll->hcill_state);
                kfree_skb(skb);
                break;
        }

        spin_unlock_irqrestore(&ll->hcill_lock, flags);

        return 0;
}

static int ll_recv_frame(struct hci_dev *hdev, struct sk_buff *skb)
{
        struct hci_uart *hu = hci_get_drvdata(hdev);
        struct ll_struct *ll = hu->priv;

        switch (hci_skb_pkt_type(skb)) {
        case HCILL_GO_TO_SLEEP_IND:
                BT_DBG("HCILL_GO_TO_SLEEP_IND packet");
                ll_device_want_to_sleep(hu);
                break;
        case HCILL_GO_TO_SLEEP_ACK:
                /* shouldn't happen */
                bt_dev_err(hdev, "received HCILL_GO_TO_SLEEP_ACK in state %ld",
                           ll->hcill_state);
                break;
        case HCILL_WAKE_UP_IND:
                BT_DBG("HCILL_WAKE_UP_IND packet");
                ll_device_want_to_wakeup(hu);
                break;
        case HCILL_WAKE_UP_ACK:
                BT_DBG("HCILL_WAKE_UP_ACK packet");
                ll_device_woke_up(hu);
                break;
        }

        kfree_skb(skb);
        return 0;
}

#define LL_RECV_SLEEP_IND \
        .type = HCILL_GO_TO_SLEEP_IND, \
        .hlen = 0, \
        .loff = 0, \
        .lsize = 0, \
        .maxlen = 0

#define LL_RECV_SLEEP_ACK \
        .type = HCILL_GO_TO_SLEEP_ACK, \
        .hlen = 0, \
        .loff = 0, \
        .lsize = 0, \
        .maxlen = 0

#define LL_RECV_WAKE_IND \
        .type = HCILL_WAKE_UP_IND, \
        .hlen = 0, \
        .loff = 0, \
        .lsize = 0, \
        .maxlen = 0

#define LL_RECV_WAKE_ACK \
        .type = HCILL_WAKE_UP_ACK, \
        .hlen = 0, \
        .loff = 0, \
        .lsize = 0, \
        .maxlen = 0

static const struct h4_recv_pkt ll_recv_pkts[] = {
        { H4_RECV_ACL,       .recv = hci_recv_frame },
        { H4_RECV_SCO,       .recv = hci_recv_frame },
        { H4_RECV_EVENT,     .recv = hci_recv_frame },
        { LL_RECV_SLEEP_IND, .recv = ll_recv_frame  },
        { LL_RECV_SLEEP_ACK, .recv = ll_recv_frame  },
        { LL_RECV_WAKE_IND,  .recv = ll_recv_frame  },
        { LL_RECV_WAKE_ACK,  .recv = ll_recv_frame  },
};

/* Recv data */
static int ll_recv(struct hci_uart *hu, const void *data, int count)
{
        struct ll_struct *ll = hu->priv;

        if (!test_bit(HCI_UART_REGISTERED, &hu->flags))
                return -EUNATCH;

        ll->rx_skb = h4_recv_buf(hu->hdev, ll->rx_skb, data, count,
                                 ll_recv_pkts, ARRAY_SIZE(ll_recv_pkts));
        if (IS_ERR(ll->rx_skb)) {
                int err = PTR_ERR(ll->rx_skb);
                bt_dev_err(hu->hdev, "Frame reassembly failed (%d)", err);
                ll->rx_skb = NULL;
                return err;
        }

        return count;
}

static struct sk_buff *ll_dequeue(struct hci_uart *hu)
{
        struct ll_struct *ll = hu->priv;

        return skb_dequeue(&ll->txq);
}

#if IS_ENABLED(CONFIG_SERIAL_DEV_BUS)
static int read_local_version(struct hci_dev *hdev)
{
        int err = 0;
        unsigned short version = 0;
        struct sk_buff *skb;
        struct hci_rp_read_local_version *ver;

        skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
                             HCI_INIT_TIMEOUT);
        if (IS_ERR(skb)) {
                bt_dev_err(hdev, "Reading TI version information failed (%ld)",
                           PTR_ERR(skb));
                return PTR_ERR(skb);
        }
        if (skb->len != sizeof(*ver)) {
                err = -EILSEQ;
                goto out;
        }

        ver = (struct hci_rp_read_local_version *)skb->data;
        if (le16_to_cpu(ver->manufacturer) != 13) {
                err = -ENODEV;
                goto out;
        }

        version = le16_to_cpu(ver->lmp_subver);

out:
        if (err)
                bt_dev_err(hdev, "Failed to read TI version info: %d", err);
        kfree_skb(skb);
        return err ? err : version;
}

static int send_command_from_firmware(struct ll_device *lldev,
                                      struct hci_command *cmd)
{
        struct sk_buff *skb;

        if (cmd->opcode == HCI_VS_UPDATE_UART_HCI_BAUDRATE) {
                /* ignore remote change
                 * baud rate HCI VS command
                 */
                bt_dev_warn(lldev->hu.hdev,
                            "change remote baud rate command in firmware");
                return 0;
        }
        if (cmd->prefix != 1)
                bt_dev_dbg(lldev->hu.hdev, "command type %d", cmd->prefix);

        skb = __hci_cmd_sync(lldev->hu.hdev, cmd->opcode, cmd->plen,
                             &cmd->speed, HCI_INIT_TIMEOUT);
        if (IS_ERR(skb)) {
                bt_dev_err(lldev->hu.hdev, "send command failed");
                return PTR_ERR(skb);
        }
        kfree_skb(skb);
        return 0;
}

/**
 * download_firmware -
 *      internal function which parses through the .bts firmware
 *      script file intreprets SEND, DELAY actions only as of now
 */
static int download_firmware(struct ll_device *lldev)
{
        unsigned short chip, min_ver, maj_ver;
        int version, err, len;
        unsigned char *ptr, *action_ptr;
        unsigned char bts_scr_name[40]; /* 40 char long bts scr name? */
        const struct firmware *fw;
        struct hci_command *cmd;

        version = read_local_version(lldev->hu.hdev);
        if (version < 0)
                return version;

        chip = (version & 0x7C00) >> 10;
        min_ver = (version & 0x007F);
        maj_ver = (version & 0x0380) >> 7;
        if (version & 0x8000)
                maj_ver |= 0x0008;

        snprintf(bts_scr_name, sizeof(bts_scr_name),
                 "ti-connectivity/TIInit_%d.%d.%d.bts",
                 chip, maj_ver, min_ver);

        err = request_firmware(&fw, bts_scr_name, &lldev->serdev->dev);
        if (err || !fw->data || !fw->size) {
                bt_dev_err(lldev->hu.hdev, "request_firmware failed(errno %d) for %s",
                           err, bts_scr_name);
                return -EINVAL;
        }
        ptr = (void *)fw->data;
        len = fw->size;
        /* bts_header to remove out magic number and
         * version
         */
        ptr += sizeof(struct bts_header);
        len -= sizeof(struct bts_header);

        while (len > 0 && ptr) {
                bt_dev_dbg(lldev->hu.hdev, " action size %d, type %d ",
                           ((struct bts_action *)ptr)->size,
                           ((struct bts_action *)ptr)->type);

                action_ptr = &(((struct bts_action *)ptr)->data[0]);

                switch (((struct bts_action *)ptr)->type) {
                case ACTION_SEND_COMMAND:       /* action send */
                        bt_dev_dbg(lldev->hu.hdev, "S");
                        cmd = (struct hci_command *)action_ptr;
                        err = send_command_from_firmware(lldev, cmd);
                        if (err)
                                goto out_rel_fw;
                        break;
                case ACTION_WAIT_EVENT:  /* wait */
                        /* no need to wait as command was synchronous */
                        bt_dev_dbg(lldev->hu.hdev, "W");
                        break;
                case ACTION_DELAY:      /* sleep */
                        bt_dev_info(lldev->hu.hdev, "sleep command in scr");
                        msleep(((struct bts_action_delay *)action_ptr)->msec);
                        break;
                }
                len -= (sizeof(struct bts_action) +
                        ((struct bts_action *)ptr)->size);
                ptr += sizeof(struct bts_action) +
                        ((struct bts_action *)ptr)->size;
        }

out_rel_fw:
        /* fw download complete */
        release_firmware(fw);
        return err;
}

static int ll_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
{
        bdaddr_t bdaddr_swapped;
        struct sk_buff *skb;

        /* HCI_VS_WRITE_BD_ADDR (at least on a CC2560A chip) expects the BD
         * address to be MSB first, but bdaddr_t has the convention of being
         * LSB first.
         */
        baswap(&bdaddr_swapped, bdaddr);
        skb = __hci_cmd_sync(hdev, HCI_VS_WRITE_BD_ADDR, sizeof(bdaddr_t),
                             &bdaddr_swapped, HCI_INIT_TIMEOUT);
        if (!IS_ERR(skb))
                kfree_skb(skb);

        return PTR_ERR_OR_ZERO(skb);
}

static int ll_setup(struct hci_uart *hu)
{
        int err, retry = 3;
        struct ll_device *lldev;
        struct serdev_device *serdev = hu->serdev;
        u32 speed;

        if (!serdev)
                return 0;

        lldev = serdev_device_get_drvdata(serdev);

        hu->hdev->set_bdaddr = ll_set_bdaddr;

        serdev_device_set_flow_control(serdev, true);

        do {
                /* Reset the Bluetooth device */
                gpiod_set_value_cansleep(lldev->enable_gpio, 0);
                msleep(5);
                gpiod_set_value_cansleep(lldev->enable_gpio, 1);
                mdelay(100);
                err = serdev_device_wait_for_cts(serdev, true, 200);
                if (err) {
                        bt_dev_err(hu->hdev, "Failed to get CTS");
                        return err;
                }

                err = download_firmware(lldev);
                if (!err)
                        break;

                /* Toggle BT_EN and retry */
                bt_dev_err(hu->hdev, "download firmware failed, retrying...");
        } while (retry--);

        if (err)
                return err;

        /* Set BD address if one was specified at probe */
        if (!bacmp(&lldev->bdaddr, BDADDR_NONE)) {
                /* This means that there was an error getting the BD address
                 * during probe, so mark the device as having a bad address.
                 */
                set_bit(HCI_QUIRK_INVALID_BDADDR, &hu->hdev->quirks);
        } else if (bacmp(&lldev->bdaddr, BDADDR_ANY)) {
                err = ll_set_bdaddr(hu->hdev, &lldev->bdaddr);
                if (err)
                        set_bit(HCI_QUIRK_INVALID_BDADDR, &hu->hdev->quirks);
        }

        /* Operational speed if any */
        if (hu->oper_speed)
                speed = hu->oper_speed;
        else if (hu->proto->oper_speed)
                speed = hu->proto->oper_speed;
        else
                speed = 0;

        if (speed) {
                __le32 speed_le = cpu_to_le32(speed);
                struct sk_buff *skb;

                skb = __hci_cmd_sync(hu->hdev, HCI_VS_UPDATE_UART_HCI_BAUDRATE,
                                     sizeof(speed_le), &speed_le,
                                     HCI_INIT_TIMEOUT);
                if (!IS_ERR(skb)) {
                        kfree_skb(skb);
                        serdev_device_set_baudrate(serdev, speed);
                }
        }

        return 0;
}

static const struct hci_uart_proto llp;

static int hci_ti_probe(struct serdev_device *serdev)
{
        struct hci_uart *hu;
        struct ll_device *lldev;
        struct nvmem_cell *bdaddr_cell;
        u32 max_speed = 3000000;

        lldev = devm_kzalloc(&serdev->dev, sizeof(struct ll_device), GFP_KERNEL);
        if (!lldev)
                return -ENOMEM;
        hu = &lldev->hu;

        serdev_device_set_drvdata(serdev, lldev);
        lldev->serdev = hu->serdev = serdev;

        lldev->enable_gpio = devm_gpiod_get_optional(&serdev->dev,
                                                     "enable",
                                                     GPIOD_OUT_LOW);
        if (IS_ERR(lldev->enable_gpio))
                return PTR_ERR(lldev->enable_gpio);

        lldev->ext_clk = devm_clk_get(&serdev->dev, "ext_clock");
        if (IS_ERR(lldev->ext_clk) && PTR_ERR(lldev->ext_clk) != -ENOENT)
                return PTR_ERR(lldev->ext_clk);

        of_property_read_u32(serdev->dev.of_node, "max-speed", &max_speed);
        hci_uart_set_speeds(hu, 115200, max_speed);

        /* optional BD address from nvram */
        bdaddr_cell = nvmem_cell_get(&serdev->dev, "bd-address");
        if (IS_ERR(bdaddr_cell)) {
                int err = PTR_ERR(bdaddr_cell);

                if (err == -EPROBE_DEFER)
                        return err;

                /* ENOENT means there is no matching nvmem cell and ENOSYS
                 * means that nvmem is not enabled in the kernel configuration.
                 */
                if (err != -ENOENT && err != -ENOSYS) {
                        /* If there was some other error, give userspace a
                         * chance to fix the problem instead of failing to load
                         * the driver. Using BDADDR_NONE as a flag that is
                         * tested later in the setup function.
                         */
                        dev_warn(&serdev->dev,
                                 "Failed to get \"bd-address\" nvmem cell (%d)\n",
                                 err);
                        bacpy(&lldev->bdaddr, BDADDR_NONE);
                }
        } else {
                bdaddr_t *bdaddr;
                size_t len;

                bdaddr = nvmem_cell_read(bdaddr_cell, &len);
                nvmem_cell_put(bdaddr_cell);
                if (IS_ERR(bdaddr)) {
                        dev_err(&serdev->dev, "Failed to read nvmem bd-address\n");
                        return PTR_ERR(bdaddr);
                }
                if (len != sizeof(bdaddr_t)) {
                        dev_err(&serdev->dev, "Invalid nvmem bd-address length\n");
                        kfree(bdaddr);
                        return -EINVAL;
                }

                /* As per the device tree bindings, the value from nvmem is
                 * expected to be MSB first, but in the kernel it is expected
                 * that bdaddr_t is LSB first.
                 */
                baswap(&lldev->bdaddr, bdaddr);
                kfree(bdaddr);
        }

        return hci_uart_register_device(hu, &llp);
}

static void hci_ti_remove(struct serdev_device *serdev)
{
        struct ll_device *lldev = serdev_device_get_drvdata(serdev);

        hci_uart_unregister_device(&lldev->hu);
}

static const struct of_device_id hci_ti_of_match[] = {
        { .compatible = "ti,cc2560" },
        { .compatible = "ti,wl1271-st" },
        { .compatible = "ti,wl1273-st" },
        { .compatible = "ti,wl1281-st" },
        { .compatible = "ti,wl1283-st" },
        { .compatible = "ti,wl1285-st" },
        { .compatible = "ti,wl1801-st" },
        { .compatible = "ti,wl1805-st" },
        { .compatible = "ti,wl1807-st" },
        { .compatible = "ti,wl1831-st" },
        { .compatible = "ti,wl1835-st" },
        { .compatible = "ti,wl1837-st" },
        {},
};
MODULE_DEVICE_TABLE(of, hci_ti_of_match);

static struct serdev_device_driver hci_ti_drv = {
        .driver         = {
                .name   = "hci-ti",
                .of_match_table = of_match_ptr(hci_ti_of_match),
        },
        .probe  = hci_ti_probe,
        .remove = hci_ti_remove,
};
#else
#define ll_setup NULL
#endif

static const struct hci_uart_proto llp = {
        .id             = HCI_UART_LL,
        .name           = "LL",
        .setup          = ll_setup,
        .open           = ll_open,
        .close          = ll_close,
        .recv           = ll_recv,
        .enqueue        = ll_enqueue,
        .dequeue        = ll_dequeue,
        .flush          = ll_flush,
};

int __init ll_init(void)
{
        serdev_device_driver_register(&hci_ti_drv);

        return hci_uart_register_proto(&llp);
}

int __exit ll_deinit(void)
{
        serdev_device_driver_unregister(&hci_ti_drv);

        return hci_uart_unregister_proto(&llp);
}