// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *
 *  Generic Bluetooth SDIO driver
 *
 *  Copyright (C) 2007  Cambridge Silicon Radio Ltd.
 *  Copyright (C) 2007  Marcel Holtmann <marcel@holtmann.org>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/errno.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>

#define VERSION "0.1"

static const struct sdio_device_id btsdio_table[] = {
        /* Generic Bluetooth Type-A SDIO device */
        { SDIO_DEVICE_CLASS(SDIO_CLASS_BT_A) },

        /* Generic Bluetooth Type-B SDIO device */
        { SDIO_DEVICE_CLASS(SDIO_CLASS_BT_B) },

        { }     /* Terminating entry */
};

MODULE_DEVICE_TABLE(sdio, btsdio_table);

struct btsdio_data {
        struct hci_dev   *hdev;
        struct sdio_func *func;

        struct work_struct work;

        struct sk_buff_head txq;
};

#define REG_RDAT     0x00       /* Receiver Data */
#define REG_TDAT     0x00       /* Transmitter Data */
#define REG_PC_RRT   0x10       /* Read Packet Control */
#define REG_PC_WRT   0x11       /* Write Packet Control */
#define REG_RTC_STAT 0x12       /* Retry Control Status */
#define REG_RTC_SET  0x12       /* Retry Control Set */
#define REG_INTRD    0x13       /* Interrupt Indication */
#define REG_CL_INTRD 0x13       /* Interrupt Clear */
#define REG_EN_INTRD 0x14       /* Interrupt Enable */
#define REG_MD_STAT  0x20       /* Bluetooth Mode Status */
#define REG_MD_SET   0x20       /* Bluetooth Mode Set */

static int btsdio_tx_packet(struct btsdio_data *data, struct sk_buff *skb)
{
        int err;

        BT_DBG("%s", data->hdev->name);

        /* Prepend Type-A header */
        skb_push(skb, 4);
        skb->data[0] = (skb->len & 0x0000ff);
        skb->data[1] = (skb->len & 0x00ff00) >> 8;
        skb->data[2] = (skb->len & 0xff0000) >> 16;
        skb->data[3] = hci_skb_pkt_type(skb);

        err = sdio_writesb(data->func, REG_TDAT, skb->data, skb->len);
        if (err < 0) {
                skb_pull(skb, 4);
                sdio_writeb(data->func, 0x01, REG_PC_WRT, NULL);
                return err;
        }

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

        kfree_skb(skb);

        return 0;
}

static void btsdio_work(struct work_struct *work)
{
        struct btsdio_data *data = container_of(work, struct btsdio_data, work);
        struct sk_buff *skb;
        int err;

        BT_DBG("%s", data->hdev->name);

        sdio_claim_host(data->func);

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

        sdio_release_host(data->func);
}

static int btsdio_rx_packet(struct btsdio_data *data)
{
        u8 hdr[4] __attribute__ ((aligned(4)));
        struct sk_buff *skb;
        int err, len;

        BT_DBG("%s", data->hdev->name);

        err = sdio_readsb(data->func, hdr, REG_RDAT, 4);
        if (err < 0)
                return err;

        len = hdr[0] | (hdr[1] << 8) | (hdr[2] << 16);
        if (len < 4 || len > 65543)
                return -EILSEQ;

        skb = bt_skb_alloc(len - 4, GFP_KERNEL);
        if (!skb) {
                /* Out of memory. Prepare a read retry and just
                 * return with the expectation that the next time
                 * we're called we'll have more memory.
                 */
                return -ENOMEM;
        }

        skb_put(skb, len - 4);

        err = sdio_readsb(data->func, skb->data, REG_RDAT, len - 4);
        if (err < 0) {
                kfree_skb(skb);
                return err;
        }

        data->hdev->stat.byte_rx += len;

        switch (hdr[3]) {
        case HCI_EVENT_PKT:
        case HCI_ACLDATA_PKT:
        case HCI_SCODATA_PKT:
        case HCI_ISODATA_PKT:
                hci_skb_pkt_type(skb) = hdr[3];
                err = hci_recv_frame(data->hdev, skb);
                if (err < 0)
                        return err;
                break;
        default:
                kfree_skb(skb);
                return -EINVAL;
        }

        sdio_writeb(data->func, 0x00, REG_PC_RRT, NULL);

        return 0;
}

static void btsdio_interrupt(struct sdio_func *func)
{
        struct btsdio_data *data = sdio_get_drvdata(func);
        int intrd;

        BT_DBG("%s", data->hdev->name);

        intrd = sdio_readb(func, REG_INTRD, NULL);
        if (intrd & 0x01) {
                sdio_writeb(func, 0x01, REG_CL_INTRD, NULL);

                if (btsdio_rx_packet(data) < 0) {
                        data->hdev->stat.err_rx++;
                        sdio_writeb(data->func, 0x01, REG_PC_RRT, NULL);
                }
        }
}

static int btsdio_open(struct hci_dev *hdev)
{
        struct btsdio_data *data = hci_get_drvdata(hdev);
        int err;

        BT_DBG("%s", hdev->name);

        sdio_claim_host(data->func);

        err = sdio_enable_func(data->func);
        if (err < 0)
                goto release;

        err = sdio_claim_irq(data->func, btsdio_interrupt);
        if (err < 0) {
                sdio_disable_func(data->func);
                goto release;
        }

        if (data->func->class == SDIO_CLASS_BT_B)
                sdio_writeb(data->func, 0x00, REG_MD_SET, NULL);

        sdio_writeb(data->func, 0x01, REG_EN_INTRD, NULL);

release:
        sdio_release_host(data->func);

        return err;
}

static int btsdio_close(struct hci_dev *hdev)
{
        struct btsdio_data *data = hci_get_drvdata(hdev);

        BT_DBG("%s", hdev->name);

        sdio_claim_host(data->func);

        sdio_writeb(data->func, 0x00, REG_EN_INTRD, NULL);

        sdio_release_irq(data->func);
        sdio_disable_func(data->func);

        sdio_release_host(data->func);

        return 0;
}

static int btsdio_flush(struct hci_dev *hdev)
{
        struct btsdio_data *data = hci_get_drvdata(hdev);

        BT_DBG("%s", hdev->name);

        skb_queue_purge(&data->txq);

        return 0;
}

static int btsdio_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
{
        struct btsdio_data *data = hci_get_drvdata(hdev);

        BT_DBG("%s", hdev->name);

        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(&data->txq, skb);

        schedule_work(&data->work);

        return 0;
}

static int btsdio_probe(struct sdio_func *func,
                                const struct sdio_device_id *id)
{
        struct btsdio_data *data;
        struct hci_dev *hdev;
        struct sdio_func_tuple *tuple = func->tuples;
        int err;

        BT_DBG("func %p id %p class 0x%04x", func, id, func->class);

        while (tuple) {
                BT_DBG("code 0x%x size %d", tuple->code, tuple->size);
                tuple = tuple->next;
        }

        /* Broadcom devices soldered onto the PCB (non-removable) use an
         * UART connection for Bluetooth, ignore the BT SDIO interface.
         */
        if (func->vendor == SDIO_VENDOR_ID_BROADCOM &&
            !mmc_card_is_removable(func->card->host)) {
                switch (func->device) {
                case SDIO_DEVICE_ID_BROADCOM_43341:
                case SDIO_DEVICE_ID_BROADCOM_43430:
                case SDIO_DEVICE_ID_BROADCOM_4345:
                case SDIO_DEVICE_ID_BROADCOM_43455:
                case SDIO_DEVICE_ID_BROADCOM_4356:
                case SDIO_DEVICE_ID_BROADCOM_CYPRESS_4373:
                        return -ENODEV;
                }
        }

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

        data->func = func;

        INIT_WORK(&data->work, btsdio_work);

        skb_queue_head_init(&data->txq);

        hdev = hci_alloc_dev();
        if (!hdev)
                return -ENOMEM;

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

        data->hdev = hdev;

        SET_HCIDEV_DEV(hdev, &func->dev);

        hdev->open     = btsdio_open;
        hdev->close    = btsdio_close;
        hdev->flush    = btsdio_flush;
        hdev->send     = btsdio_send_frame;

        if (func->vendor == 0x0104 && func->device == 0x00c5)
                hci_set_quirk(hdev, HCI_QUIRK_RESET_ON_CLOSE);

        err = hci_register_dev(hdev);
        if (err < 0) {
                hci_free_dev(hdev);
                return err;
        }

        sdio_set_drvdata(func, data);

        return 0;
}

static void btsdio_remove(struct sdio_func *func)
{
        struct btsdio_data *data = sdio_get_drvdata(func);
        struct hci_dev *hdev;

        BT_DBG("func %p", func);

        if (!data)
                return;

        cancel_work_sync(&data->work);
        hdev = data->hdev;

        sdio_set_drvdata(func, NULL);

        hci_unregister_dev(hdev);

        hci_free_dev(hdev);
}

static struct sdio_driver btsdio_driver = {
        .name           = "btsdio",
        .probe          = btsdio_probe,
        .remove         = btsdio_remove,
        .id_table       = btsdio_table,
};

module_sdio_driver(btsdio_driver);

MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
MODULE_DESCRIPTION("Generic Bluetooth SDIO driver ver " VERSION);
MODULE_VERSION(VERSION);
MODULE_LICENSE("GPL");