// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2019 MediaTek Inc.

/*
 * Bluetooth support for MediaTek SDIO devices
 *
 * This file is written based on btsdio.c and btmtkuart.c.
 *
 * Author: Sean Wang <sean.wang@mediatek.com>
 *
 */

#include <asm/unaligned.h>
#include <linux/atomic.h>
#include <linux/firmware.h>
#include <linux/init.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>
#include <linux/skbuff.h>

#include <linux/mmc/host.h>
#include <linux/mmc/sdio_ids.h>
#include <linux/mmc/sdio_func.h>

#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>

#include "h4_recv.h"

#define VERSION "0.1"

#define FIRMWARE_MT7663         "mediatek/mt7663pr2h.bin"
#define FIRMWARE_MT7668         "mediatek/mt7668pr2h.bin"

#define MTKBTSDIO_AUTOSUSPEND_DELAY     8000

static bool enable_autosuspend;

struct btmtksdio_data {
        const char *fwname;
};

static const struct btmtksdio_data mt7663_data = {
        .fwname = FIRMWARE_MT7663,
};

static const struct btmtksdio_data mt7668_data = {
        .fwname = FIRMWARE_MT7668,
};

static const struct sdio_device_id btmtksdio_table[] = {
        {SDIO_DEVICE(SDIO_VENDOR_ID_MEDIATEK, 0x7663),
         .driver_data = (kernel_ulong_t)&mt7663_data },
        {SDIO_DEVICE(SDIO_VENDOR_ID_MEDIATEK, 0x7668),
         .driver_data = (kernel_ulong_t)&mt7668_data },
        { }     /* Terminating entry */
};

#define MTK_REG_CHLPCR          0x4     /* W1S */
#define C_INT_EN_SET            BIT(0)
#define C_INT_EN_CLR            BIT(1)
#define C_FW_OWN_REQ_SET        BIT(8)  /* For write */
#define C_COM_DRV_OWN           BIT(8)  /* For read */
#define C_FW_OWN_REQ_CLR        BIT(9)

#define MTK_REG_CSDIOCSR        0x8
#define SDIO_RE_INIT_EN         BIT(0)
#define SDIO_INT_CTL            BIT(2)

#define MTK_REG_CHCR            0xc
#define C_INT_CLR_CTRL          BIT(1)

/* CHISR have the same bits field definition with CHIER */
#define MTK_REG_CHISR           0x10
#define MTK_REG_CHIER           0x14
#define FW_OWN_BACK_INT         BIT(0)
#define RX_DONE_INT             BIT(1)
#define TX_EMPTY                BIT(2)
#define TX_FIFO_OVERFLOW        BIT(8)
#define RX_PKT_LEN              GENMASK(31, 16)

#define MTK_REG_CTDR            0x18

#define MTK_REG_CRDR            0x1c

#define MTK_SDIO_BLOCK_SIZE     256

#define BTMTKSDIO_TX_WAIT_VND_EVT       1

enum {
        MTK_WMT_PATCH_DWNLD = 0x1,
        MTK_WMT_TEST = 0x2,
        MTK_WMT_WAKEUP = 0x3,
        MTK_WMT_HIF = 0x4,
        MTK_WMT_FUNC_CTRL = 0x6,
        MTK_WMT_RST = 0x7,
        MTK_WMT_SEMAPHORE = 0x17,
};

enum {
        BTMTK_WMT_INVALID,
        BTMTK_WMT_PATCH_UNDONE,
        BTMTK_WMT_PATCH_DONE,
        BTMTK_WMT_ON_UNDONE,
        BTMTK_WMT_ON_DONE,
        BTMTK_WMT_ON_PROGRESS,
};

struct mtkbtsdio_hdr {
        __le16  len;
        __le16  reserved;
        u8      bt_type;
} __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 btmtk_hci_wmt_evt {
        struct hci_event_hdr hhdr;
        struct mtk_wmt_hdr whdr;
} __packed;

struct btmtk_hci_wmt_evt_funcc {
        struct btmtk_hci_wmt_evt hwhdr;
        __be16 status;
} __packed;

struct btmtk_tci_sleep {
        u8 mode;
        __le16 duration;
        __le16 host_duration;
        u8 host_wakeup_pin;
        u8 time_compensation;
} __packed;

struct btmtk_hci_wmt_params {
        u8 op;
        u8 flag;
        u16 dlen;
        const void *data;
        u32 *status;
};

struct btmtksdio_dev {
        struct hci_dev *hdev;
        struct sdio_func *func;
        struct device *dev;

        struct work_struct tx_work;
        unsigned long tx_state;
        struct sk_buff_head txq;

        struct sk_buff *evt_skb;

        const struct btmtksdio_data *data;
};

static int mtk_hci_wmt_sync(struct hci_dev *hdev,
                            struct btmtk_hci_wmt_params *wmt_params)
{
        struct btmtksdio_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 mtk_hci_wmt_cmd wc;
        struct mtk_wmt_hdr *hdr;
        int err;

        hlen = sizeof(*hdr) + wmt_params->dlen;
        if (hlen > 255)
                return -EINVAL;

        hdr = (struct mtk_wmt_hdr *)&wc;
        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(BTMTKSDIO_TX_WAIT_VND_EVT, &bdev->tx_state);

        err = __hci_cmd_send(hdev, 0xfc6f, hlen, &wc);
        if (err < 0) {
                clear_bit(BTMTKSDIO_TX_WAIT_VND_EVT, &bdev->tx_state);
                return err;
        }

        /* 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 BTMTKSDIO_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, BTMTKSDIO_TX_WAIT_VND_EVT,
                                  TASK_INTERRUPTIBLE, HCI_INIT_TIMEOUT);
        if (err == -EINTR) {
                bt_dev_err(hdev, "Execution of wmt command interrupted");
                clear_bit(BTMTKSDIO_TX_WAIT_VND_EVT, &bdev->tx_state);
                return err;
        }

        if (err) {
                bt_dev_err(hdev, "Execution of wmt command timed out");
                clear_bit(BTMTKSDIO_TX_WAIT_VND_EVT, &bdev->tx_state);
                return -ETIMEDOUT;
        }

        /* 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_skb;
        }

        switch (wmt_evt->whdr.op) {
        case MTK_WMT_SEMAPHORE:
                if (wmt_evt->whdr.flag == 2)
                        status = BTMTK_WMT_PATCH_UNDONE;
                else
                        status = BTMTK_WMT_PATCH_DONE;
                break;
        case MTK_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_skb:
        kfree_skb(bdev->evt_skb);
        bdev->evt_skb = NULL;

        return err;
}

static int btmtksdio_tx_packet(struct btmtksdio_dev *bdev,
                               struct sk_buff *skb)
{
        struct mtkbtsdio_hdr *sdio_hdr;
        int err;

        /* Make sure that there are enough rooms for SDIO header */
        if (unlikely(skb_headroom(skb) < sizeof(*sdio_hdr))) {
                err = pskb_expand_head(skb, sizeof(*sdio_hdr), 0,
                                       GFP_ATOMIC);
                if (err < 0)
                        return err;
        }

        /* Prepend MediaTek SDIO Specific Header */
        skb_push(skb, sizeof(*sdio_hdr));

        sdio_hdr = (void *)skb->data;
        sdio_hdr->len = cpu_to_le16(skb->len);
        sdio_hdr->reserved = cpu_to_le16(0);
        sdio_hdr->bt_type = hci_skb_pkt_type(skb);

        err = sdio_writesb(bdev->func, MTK_REG_CTDR, skb->data,
                           round_up(skb->len, MTK_SDIO_BLOCK_SIZE));
        if (err < 0)
                goto err_skb_pull;

        bdev->hdev->stat.byte_tx += skb->len;

        kfree_skb(skb);

        return 0;

err_skb_pull:
        skb_pull(skb, sizeof(*sdio_hdr));

        return err;
}

static u32 btmtksdio_drv_own_query(struct btmtksdio_dev *bdev)
{
        return sdio_readl(bdev->func, MTK_REG_CHLPCR, NULL);
}

static void btmtksdio_tx_work(struct work_struct *work)
{
        struct btmtksdio_dev *bdev = container_of(work, struct btmtksdio_dev,
                                                  tx_work);
        struct sk_buff *skb;
        int err;

        pm_runtime_get_sync(bdev->dev);

        sdio_claim_host(bdev->func);

        while ((skb = skb_dequeue(&bdev->txq))) {
                err = btmtksdio_tx_packet(bdev, skb);
                if (err < 0) {
                        bdev->hdev->stat.err_tx++;
                        skb_queue_head(&bdev->txq, skb);
                        break;
                }
        }

        sdio_release_host(bdev->func);

        pm_runtime_mark_last_busy(bdev->dev);
        pm_runtime_put_autosuspend(bdev->dev);
}

static int btmtksdio_recv_event(struct hci_dev *hdev, struct sk_buff *skb)
{
        struct btmtksdio_dev *bdev = hci_get_drvdata(hdev);
        struct hci_event_hdr *hdr = (void *)skb->data;
        int err;

        /* Fix up the vendor event id with 0xff for vendor specific instead
         * of 0xe4 so that event send via monitoring socket can be parsed
         * properly.
         */
        if (hdr->evt == 0xe4)
                hdr->evt = HCI_EV_VENDOR;

        /* When someone waits for the WMT event, the skb is being cloned
         * and being processed the events from there then.
         */
        if (test_bit(BTMTKSDIO_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_VENDOR) {
                if (test_and_clear_bit(BTMTKSDIO_TX_WAIT_VND_EVT,
                                       &bdev->tx_state)) {
                        /* Barrier to sync with other CPUs */
                        smp_mb__after_atomic();
                        wake_up_bit(&bdev->tx_state, BTMTKSDIO_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 = btmtksdio_recv_event },
};

static int btmtksdio_rx_packet(struct btmtksdio_dev *bdev, u16 rx_size)
{
        const struct h4_recv_pkt *pkts = mtk_recv_pkts;
        int pkts_count = ARRAY_SIZE(mtk_recv_pkts);
        struct mtkbtsdio_hdr *sdio_hdr;
        int err, i, pad_size;
        struct sk_buff *skb;
        u16 dlen;

        if (rx_size < sizeof(*sdio_hdr))
                return -EILSEQ;

        /* A SDIO packet is exactly containing a Bluetooth packet */
        skb = bt_skb_alloc(rx_size, GFP_KERNEL);
        if (!skb)
                return -ENOMEM;

        skb_put(skb, rx_size);

        err = sdio_readsb(bdev->func, skb->data, MTK_REG_CRDR, rx_size);
        if (err < 0)
                goto err_kfree_skb;

        sdio_hdr = (void *)skb->data;

        /* We assume the default error as -EILSEQ simply to make the error path
         * be cleaner.
         */
        err = -EILSEQ;

        if (rx_size != le16_to_cpu(sdio_hdr->len)) {
                bt_dev_err(bdev->hdev, "Rx size in sdio header is mismatched ");
                goto err_kfree_skb;
        }

        hci_skb_pkt_type(skb) = sdio_hdr->bt_type;

        /* Remove MediaTek SDIO header */
        skb_pull(skb, sizeof(*sdio_hdr));

        /* We have to dig into the packet to get payload size and then know how
         * many padding bytes at the tail, these padding bytes should be removed
         * before the packet is indicated to the core layer.
         */
        for (i = 0; i < pkts_count; i++) {
                if (sdio_hdr->bt_type == (&pkts[i])->type)
                        break;
        }

        if (i >= pkts_count) {
                bt_dev_err(bdev->hdev, "Invalid bt type 0x%02x",
                           sdio_hdr->bt_type);
                goto err_kfree_skb;
        }

        /* Remaining bytes cannot hold a header*/
        if (skb->len < (&pkts[i])->hlen) {
                bt_dev_err(bdev->hdev, "The size of bt header is mismatched");
                goto err_kfree_skb;
        }

        switch ((&pkts[i])->lsize) {
                case 1:
                        dlen = skb->data[(&pkts[i])->loff];
                        break;
                case 2:
                        dlen = get_unaligned_le16(skb->data +
                                                  (&pkts[i])->loff);
                        break;
                default:
                        goto err_kfree_skb;
        }

        pad_size = skb->len - (&pkts[i])->hlen -  dlen;

        /* Remaining bytes cannot hold a payload */
        if (pad_size < 0) {
                bt_dev_err(bdev->hdev, "The size of bt payload is mismatched");
                goto err_kfree_skb;
        }

        /* Remove padding bytes */
        skb_trim(skb, skb->len - pad_size);

        /* Complete frame */
        (&pkts[i])->recv(bdev->hdev, skb);

        bdev->hdev->stat.byte_rx += rx_size;

        return 0;

err_kfree_skb:
        kfree_skb(skb);

        return err;
}

static void btmtksdio_interrupt(struct sdio_func *func)
{
        struct btmtksdio_dev *bdev = sdio_get_drvdata(func);
        u32 int_status;
        u16 rx_size;

        /* It is required that the host gets ownership from the device before
         * accessing any register, however, if SDIO host is not being released,
         * a potential deadlock probably happens in a circular wait between SDIO
         * IRQ work and PM runtime work. So, we have to explicitly release SDIO
         * host here and claim again after the PM runtime work is all done.
         */
        sdio_release_host(bdev->func);

        pm_runtime_get_sync(bdev->dev);

        sdio_claim_host(bdev->func);

        /* Disable interrupt */
        sdio_writel(func, C_INT_EN_CLR, MTK_REG_CHLPCR, 0);

        int_status = sdio_readl(func, MTK_REG_CHISR, NULL);

        /* Ack an interrupt as soon as possible before any operation on
         * hardware.
         *
         * Note that we don't ack any status during operations to avoid race
         * condition between the host and the device such as it's possible to
         * mistakenly ack RX_DONE for the next packet and then cause interrupts
         * not be raised again but there is still pending data in the hardware
         * FIFO.
         */
        sdio_writel(func, int_status, MTK_REG_CHISR, NULL);

        if (unlikely(!int_status))
                bt_dev_err(bdev->hdev, "CHISR is 0");

        if (int_status & FW_OWN_BACK_INT)
                bt_dev_dbg(bdev->hdev, "Get fw own back");

        if (int_status & TX_EMPTY)
                schedule_work(&bdev->tx_work);
        else if (unlikely(int_status & TX_FIFO_OVERFLOW))
                bt_dev_warn(bdev->hdev, "Tx fifo overflow");

        if (int_status & RX_DONE_INT) {
                rx_size = (int_status & RX_PKT_LEN) >> 16;

                if (btmtksdio_rx_packet(bdev, rx_size) < 0)
                        bdev->hdev->stat.err_rx++;
        }

        /* Enable interrupt */
        sdio_writel(func, C_INT_EN_SET, MTK_REG_CHLPCR, 0);

        pm_runtime_mark_last_busy(bdev->dev);
        pm_runtime_put_autosuspend(bdev->dev);
}

static int btmtksdio_open(struct hci_dev *hdev)
{
        struct btmtksdio_dev *bdev = hci_get_drvdata(hdev);
        int err;
        u32 status;

        sdio_claim_host(bdev->func);

        err = sdio_enable_func(bdev->func);
        if (err < 0)
                goto err_release_host;

        /* Get ownership from the device */
        sdio_writel(bdev->func, C_FW_OWN_REQ_CLR, MTK_REG_CHLPCR, &err);
        if (err < 0)
                goto err_disable_func;

        err = readx_poll_timeout(btmtksdio_drv_own_query, bdev, status,
                                 status & C_COM_DRV_OWN, 2000, 1000000);
        if (err < 0) {
                bt_dev_err(bdev->hdev, "Cannot get ownership from device");
                goto err_disable_func;
        }

        /* Disable interrupt & mask out all interrupt sources */
        sdio_writel(bdev->func, C_INT_EN_CLR, MTK_REG_CHLPCR, &err);
        if (err < 0)
                goto err_disable_func;

        sdio_writel(bdev->func, 0, MTK_REG_CHIER, &err);
        if (err < 0)
                goto err_disable_func;

        err = sdio_claim_irq(bdev->func, btmtksdio_interrupt);
        if (err < 0)
                goto err_disable_func;

        err = sdio_set_block_size(bdev->func, MTK_SDIO_BLOCK_SIZE);
        if (err < 0)
                goto err_release_irq;

        /* SDIO CMD 5 allows the SDIO device back to idle state an
         * synchronous interrupt is supported in SDIO 4-bit mode
         */
        sdio_writel(bdev->func, SDIO_INT_CTL | SDIO_RE_INIT_EN,
                    MTK_REG_CSDIOCSR, &err);
        if (err < 0)
                goto err_release_irq;

        /* Setup write-1-clear for CHISR register */
        sdio_writel(bdev->func, C_INT_CLR_CTRL, MTK_REG_CHCR, &err);
        if (err < 0)
                goto err_release_irq;

        /* Setup interrupt sources */
        sdio_writel(bdev->func, RX_DONE_INT | TX_EMPTY | TX_FIFO_OVERFLOW,
                    MTK_REG_CHIER, &err);
        if (err < 0)
                goto err_release_irq;

        /* Enable interrupt */
        sdio_writel(bdev->func, C_INT_EN_SET, MTK_REG_CHLPCR, &err);
        if (err < 0)
                goto err_release_irq;

        sdio_release_host(bdev->func);

        return 0;

err_release_irq:
        sdio_release_irq(bdev->func);

err_disable_func:
        sdio_disable_func(bdev->func);

err_release_host:
        sdio_release_host(bdev->func);

        return err;
}

static int btmtksdio_close(struct hci_dev *hdev)
{
        struct btmtksdio_dev *bdev = hci_get_drvdata(hdev);
        u32 status;
        int err;

        sdio_claim_host(bdev->func);

        /* Disable interrupt */
        sdio_writel(bdev->func, C_INT_EN_CLR, MTK_REG_CHLPCR, NULL);

        sdio_release_irq(bdev->func);

        /* Return ownership to the device */
        sdio_writel(bdev->func, C_FW_OWN_REQ_SET, MTK_REG_CHLPCR, NULL);

        err = readx_poll_timeout(btmtksdio_drv_own_query, bdev, status,
                                 !(status & C_COM_DRV_OWN), 2000, 1000000);
        if (err < 0)
                bt_dev_err(bdev->hdev, "Cannot return ownership to device");

        sdio_disable_func(bdev->func);

        sdio_release_host(bdev->func);

        return 0;
}

static int btmtksdio_flush(struct hci_dev *hdev)
{
        struct btmtksdio_dev *bdev = hci_get_drvdata(hdev);

        skb_queue_purge(&bdev->txq);

        cancel_work_sync(&bdev->tx_work);

        return 0;
}

static int btmtksdio_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 = MTK_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 mtk_setup_firmware(struct hci_dev *hdev, const char *fwname)
{
        struct btmtk_hci_wmt_params wmt_params;
        const struct firmware *fw;
        const u8 *fw_ptr;
        size_t fw_size;
        int err, dlen;
        u8 flag;

        err = request_firmware(&fw, fwname, &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) {
                err = -EINVAL;
                goto free_fw;
        }

        fw_size -= 30;
        fw_ptr += 30;
        flag = 1;

        wmt_params.op = MTK_WMT_PATCH_DWNLD;
        wmt_params.status = NULL;

        while (fw_size > 0) {
                dlen = min_t(int, 250, fw_size);

                /* Tell device the position in sequence */
                if (fw_size - dlen <= 0)
                        flag = 3;
                else if (fw_size < fw->size - 30)
                        flag = 2;

                wmt_params.flag = flag;
                wmt_params.dlen = dlen;
                wmt_params.data = fw_ptr;

                err = mtk_hci_wmt_sync(hdev, &wmt_params);
                if (err < 0) {
                        bt_dev_err(hdev, "Failed to send wmt patch dwnld (%d)",
                                   err);
                        goto free_fw;
                }

                fw_size -= dlen;
                fw_ptr += dlen;
        }

        wmt_params.op = MTK_WMT_RST;
        wmt_params.flag = 4;
        wmt_params.dlen = 0;
        wmt_params.data = NULL;
        wmt_params.status = NULL;

        /* Activate funciton the firmware providing to */
        err = mtk_hci_wmt_sync(hdev, &wmt_params);
        if (err < 0) {
                bt_dev_err(hdev, "Failed to send wmt rst (%d)", err);
                goto free_fw;
        }

        /* Wait a few moments for firmware activation done */
        usleep_range(10000, 12000);

free_fw:
        release_firmware(fw);
        return err;
}

static int btmtksdio_setup(struct hci_dev *hdev)
{
        struct btmtksdio_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();

        /* Query whether the firmware is already download */
        wmt_params.op = MTK_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 = mtk_setup_firmware(hdev, bdev->data->fwname);
        if (err < 0)
                return err;

ignore_setup_fw:
        /* Query whether the device is already enabled */
        err = readx_poll_timeout(btmtksdio_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 = MTK_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;

        pm_runtime_set_autosuspend_delay(bdev->dev,
                                         MTKBTSDIO_AUTOSUSPEND_DELAY);
        pm_runtime_use_autosuspend(bdev->dev);

        err = pm_runtime_set_active(bdev->dev);
        if (err < 0)
                return err;

        /* Default forbid runtime auto suspend, that can be allowed by
         * enable_autosuspend flag or the PM runtime entry under sysfs.
         */
        pm_runtime_forbid(bdev->dev);
        pm_runtime_enable(bdev->dev);

        if (enable_autosuspend)
                pm_runtime_allow(bdev->dev);

        bt_dev_info(hdev, "Device setup in %llu usecs", duration);

        return 0;
}

static int btmtksdio_shutdown(struct hci_dev *hdev)
{
        struct btmtksdio_dev *bdev = hci_get_drvdata(hdev);
        struct btmtk_hci_wmt_params wmt_params;
        u8 param = 0x0;
        int err;

        /* Get back the state to be consistent with the state
         * in btmtksdio_setup.
         */
        pm_runtime_get_sync(bdev->dev);

        /* Disable the device */
        wmt_params.op = MTK_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;
        }

        pm_runtime_put_noidle(bdev->dev);
        pm_runtime_disable(bdev->dev);

        return 0;
}

static int btmtksdio_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
{
        struct btmtksdio_dev *bdev = hci_get_drvdata(hdev);

        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;

        default:
                return -EILSEQ;
        }

        skb_queue_tail(&bdev->txq, skb);

        schedule_work(&bdev->tx_work);

        return 0;
}

static int btmtksdio_probe(struct sdio_func *func,
                           const struct sdio_device_id *id)
{
        struct btmtksdio_dev *bdev;
        struct hci_dev *hdev;
        int err;

        bdev = devm_kzalloc(&func->dev, sizeof(*bdev), GFP_KERNEL);
        if (!bdev)
                return -ENOMEM;

        bdev->data = (void *)id->driver_data;
        if (!bdev->data)
                return -ENODEV;

        bdev->dev = &func->dev;
        bdev->func = func;

        INIT_WORK(&bdev->tx_work, btmtksdio_tx_work);
        skb_queue_head_init(&bdev->txq);

        /* Initialize and register HCI device */
        hdev = hci_alloc_dev();
        if (!hdev) {
                dev_err(&func->dev, "Can't allocate HCI device\n");
                return -ENOMEM;
        }

        bdev->hdev = hdev;

        hdev->bus = HCI_SDIO;
        hci_set_drvdata(hdev, bdev);

        hdev->open     = btmtksdio_open;
        hdev->close    = btmtksdio_close;
        hdev->flush    = btmtksdio_flush;
        hdev->setup    = btmtksdio_setup;
        hdev->shutdown = btmtksdio_shutdown;
        hdev->send     = btmtksdio_send_frame;
        SET_HCIDEV_DEV(hdev, &func->dev);

        hdev->manufacturer = 70;
        set_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks);

        err = hci_register_dev(hdev);
        if (err < 0) {
                dev_err(&func->dev, "Can't register HCI device\n");
                hci_free_dev(hdev);
                return err;
        }

        sdio_set_drvdata(func, bdev);

        /* pm_runtime_enable would be done after the firmware is being
         * downloaded because the core layer probably already enables
         * runtime PM for this func such as the case host->caps &
         * MMC_CAP_POWER_OFF_CARD.
         */
        if (pm_runtime_enabled(bdev->dev))
                pm_runtime_disable(bdev->dev);

        /* As explaination in drivers/mmc/core/sdio_bus.c tells us:
         * Unbound SDIO functions are always suspended.
         * During probe, the function is set active and the usage count
         * is incremented.  If the driver supports runtime PM,
         * it should call pm_runtime_put_noidle() in its probe routine and
         * pm_runtime_get_noresume() in its remove routine.
         *
         * So, put a pm_runtime_put_noidle here !
         */
        pm_runtime_put_noidle(bdev->dev);

        return 0;
}

static void btmtksdio_remove(struct sdio_func *func)

{
        struct btmtksdio_dev *bdev = sdio_get_drvdata(func);
        struct hci_dev *hdev;

        if (!bdev)
                return;

        /* Be consistent the state in btmtksdio_probe */
        pm_runtime_get_noresume(bdev->dev);

        hdev = bdev->hdev;

        sdio_set_drvdata(func, NULL);
        hci_unregister_dev(hdev);
        hci_free_dev(hdev);
}

#ifdef CONFIG_PM
static int btmtksdio_runtime_suspend(struct device *dev)
{
        struct sdio_func *func = dev_to_sdio_func(dev);
        struct btmtksdio_dev *bdev;
        u32 status;
        int err;

        bdev = sdio_get_drvdata(func);
        if (!bdev)
                return 0;

        sdio_claim_host(bdev->func);

        sdio_writel(bdev->func, C_FW_OWN_REQ_SET, MTK_REG_CHLPCR, &err);
        if (err < 0)
                goto out;

        err = readx_poll_timeout(btmtksdio_drv_own_query, bdev, status,
                                 !(status & C_COM_DRV_OWN), 2000, 1000000);
out:
        bt_dev_info(bdev->hdev, "status (%d) return ownership to device", err);

        sdio_release_host(bdev->func);

        return err;
}

static int btmtksdio_runtime_resume(struct device *dev)
{
        struct sdio_func *func = dev_to_sdio_func(dev);
        struct btmtksdio_dev *bdev;
        u32 status;
        int err;

        bdev = sdio_get_drvdata(func);
        if (!bdev)
                return 0;

        sdio_claim_host(bdev->func);

        sdio_writel(bdev->func, C_FW_OWN_REQ_CLR, MTK_REG_CHLPCR, &err);
        if (err < 0)
                goto out;

        err = readx_poll_timeout(btmtksdio_drv_own_query, bdev, status,
                                 status & C_COM_DRV_OWN, 2000, 1000000);
out:
        bt_dev_info(bdev->hdev, "status (%d) get ownership from device", err);

        sdio_release_host(bdev->func);

        return err;
}

static UNIVERSAL_DEV_PM_OPS(btmtksdio_pm_ops, btmtksdio_runtime_suspend,
                            btmtksdio_runtime_resume, NULL);
#define BTMTKSDIO_PM_OPS (&btmtksdio_pm_ops)
#else   /* CONFIG_PM */
#define BTMTKSDIO_PM_OPS NULL
#endif  /* CONFIG_PM */

static struct sdio_driver btmtksdio_driver = {
        .name           = "btmtksdio",
        .probe          = btmtksdio_probe,
        .remove         = btmtksdio_remove,
        .id_table       = btmtksdio_table,
        .drv = {
                .owner = THIS_MODULE,
                .pm = BTMTKSDIO_PM_OPS,
        }
};

module_sdio_driver(btmtksdio_driver);

module_param(enable_autosuspend, bool, 0644);
MODULE_PARM_DESC(enable_autosuspend, "Enable autosuspend by default");

MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
MODULE_DESCRIPTION("MediaTek Bluetooth SDIO driver ver " VERSION);
MODULE_VERSION(VERSION);
MODULE_LICENSE("GPL");
MODULE_FIRMWARE(FIRMWARE_MT7663);
MODULE_FIRMWARE(FIRMWARE_MT7668);