perf tools: Don't clone maps from parent when synthesizing forks

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

// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2018 MediaTek Inc.

/*
 * Bluetooth support for MediaTek serial devices
 *
 * Author: Sean Wang <sean.wang@mediatek.com>
 *
 */

#include <asm/unaligned.h>
#include <linux/atomic.h>
#include <linux/clk.h>
#include <linux/firmware.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.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 "h4_recv.h"

#define VERSION "0.1"

#define FIRMWARE_MT7622         "mediatek/mt7622pr2h.bin"

#define MTK_STP_TLR_SIZE        2

#define BTMTKUART_TX_STATE_ACTIVE       1
#define BTMTKUART_TX_STATE_WAKEUP       2
#define BTMTKUART_TX_WAIT_VND_EVT       3

enum {
        MTK_WMT_PATCH_DWNLD = 0x1,
        MTK_WMT_FUNC_CTRL = 0x6,
        MTK_WMT_RST = 0x7
};

struct mtk_stp_hdr {
        u8      prefix;
        __be16  dlen;
        u8      cs;
} __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 btmtkuart_dev {
        struct hci_dev *hdev;
        struct serdev_device *serdev;
        struct clk *clk;

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

        struct sk_buff *rx_skb;

        u8      stp_pad[6];
        u8      stp_cursor;
        u16     stp_dlen;
};

static int mtk_hci_wmt_sync(struct hci_dev *hdev, u8 op, u8 flag, u16 plen,
                            const void *param)
{
        struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
        struct mtk_hci_wmt_cmd wc;
        struct mtk_wmt_hdr *hdr;
        u32 hlen;
        int err;

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

        hdr = (struct mtk_wmt_hdr *)&wc;
        hdr->dir = 1;
        hdr->op = op;
        hdr->dlen = cpu_to_le16(plen + 1);
        hdr->flag = flag;
        memcpy(wc.data, param, plen);

        set_bit(BTMTKUART_TX_WAIT_VND_EVT, &bdev->tx_state);

        err = __hci_cmd_send(hdev, 0xfc6f, hlen, &wc);
        if (err < 0) {
                clear_bit(BTMTKUART_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 BTMTKUART_TX_WAIT_VND_EVT
         * state to be cleared. The driver speicfic event receive routine
         * will clear that state and with that indicate completion of the
         * WMT command.
         */
        err = wait_on_bit_timeout(&bdev->tx_state, BTMTKUART_TX_WAIT_VND_EVT,
                                  TASK_INTERRUPTIBLE, HCI_INIT_TIMEOUT);
        if (err == -EINTR) {
                bt_dev_err(hdev, "Execution of wmt command interrupted");
                return err;
        }

        if (err) {
                bt_dev_err(hdev, "Execution of wmt command timed out");
                return -ETIMEDOUT;
        }

        return 0;
}

static int mtk_setup_fw(struct hci_dev *hdev)
{
        const struct firmware *fw;
        const u8 *fw_ptr;
        size_t fw_size;
        int err, dlen;
        u8 flag;

        err = request_firmware(&fw, FIRMWARE_MT7622, &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;

        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;

                err = mtk_hci_wmt_sync(hdev, MTK_WMT_PATCH_DWNLD, flag, dlen,
                                       fw_ptr);
                if (err < 0) {
                        bt_dev_err(hdev, "Failed to send wmt patch dwnld (%d)",
                                   err);
                        break;
                }

                fw_size -= dlen;
                fw_ptr += dlen;
        }

free_fw:
        release_firmware(fw);
        return err;
}

static int btmtkuart_recv_event(struct hci_dev *hdev, struct sk_buff *skb)
{
        struct btmtkuart_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;

        err = hci_recv_frame(hdev, skb);

        if (hdr->evt == HCI_EV_VENDOR) {
                if (test_and_clear_bit(BTMTKUART_TX_WAIT_VND_EVT,
                                       &bdev->tx_state)) {
                        /* Barrier to sync with other CPUs */
                        smp_mb__after_atomic();
                        wake_up_bit(&bdev->tx_state, BTMTKUART_TX_WAIT_VND_EVT);
                }
        }

        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 = btmtkuart_recv_event },
};

static void btmtkuart_tx_work(struct work_struct *work)
{
        struct btmtkuart_dev *bdev = container_of(work, struct btmtkuart_dev,
                                                   tx_work);
        struct serdev_device *serdev = bdev->serdev;
        struct hci_dev *hdev = bdev->hdev;

        while (1) {
                clear_bit(BTMTKUART_TX_STATE_WAKEUP, &bdev->tx_state);

                while (1) {
                        struct sk_buff *skb = skb_dequeue(&bdev->txq);
                        int len;

                        if (!skb)
                                break;

                        len = serdev_device_write_buf(serdev, skb->data,
                                                      skb->len);
                        hdev->stat.byte_tx += len;

                        skb_pull(skb, len);
                        if (skb->len > 0) {
                                skb_queue_head(&bdev->txq, skb);
                                break;
                        }

                        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;
                        }

                        kfree_skb(skb);
                }

                if (!test_bit(BTMTKUART_TX_STATE_WAKEUP, &bdev->tx_state))
                        break;
        }

        clear_bit(BTMTKUART_TX_STATE_ACTIVE, &bdev->tx_state);
}

static void btmtkuart_tx_wakeup(struct btmtkuart_dev *bdev)
{
        if (test_and_set_bit(BTMTKUART_TX_STATE_ACTIVE, &bdev->tx_state))
                set_bit(BTMTKUART_TX_STATE_WAKEUP, &bdev->tx_state);

        schedule_work(&bdev->tx_work);
}

static const unsigned char *
mtk_stp_split(struct btmtkuart_dev *bdev, const unsigned char *data, int count,
              int *sz_h4)
{
        struct mtk_stp_hdr *shdr;

        /* The cursor is reset when all the data of STP is consumed out */
        if (!bdev->stp_dlen && bdev->stp_cursor >= 6)
                bdev->stp_cursor = 0;

        /* Filling pad until all STP info is obtained */
        while (bdev->stp_cursor < 6 && count > 0) {
                bdev->stp_pad[bdev->stp_cursor] = *data;
                bdev->stp_cursor++;
                data++;
                count--;
        }

        /* Retrieve STP info and have a sanity check */
        if (!bdev->stp_dlen && bdev->stp_cursor >= 6) {
                shdr = (struct mtk_stp_hdr *)&bdev->stp_pad[2];
                bdev->stp_dlen = be16_to_cpu(shdr->dlen) & 0x0fff;

                /* Resync STP when unexpected data is being read */
                if (shdr->prefix != 0x80 || bdev->stp_dlen > 2048) {
                        bt_dev_err(bdev->hdev, "stp format unexpect (%d, %d)",
                                   shdr->prefix, bdev->stp_dlen);
                        bdev->stp_cursor = 2;
                        bdev->stp_dlen = 0;
                }
        }

        /* Directly quit when there's no data found for H4 can process */
        if (count <= 0)
                return NULL;

        /* Tranlate to how much the size of data H4 can handle so far */
        *sz_h4 = min_t(int, count, bdev->stp_dlen);

        /* Update the remaining size of STP packet */
        bdev->stp_dlen -= *sz_h4;

        /* Data points to STP payload which can be handled by H4 */
        return data;
}

static int btmtkuart_recv(struct hci_dev *hdev, const u8 *data, size_t count)
{
        struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
        const unsigned char *p_left = data, *p_h4;
        int sz_left = count, sz_h4, adv;
        int err;

        while (sz_left > 0) {
                /*  The serial data received from MT7622 BT controller is
                 *  at all time padded around with the STP header and tailer.
                 *
                 *  A full STP packet is looking like
                 *   -----------------------------------
                 *  | STP header  |  H:4   | STP tailer |
                 *   -----------------------------------
                 *  but it doesn't guarantee to contain a full H:4 packet which
                 *  means that it's possible for multiple STP packets forms a
                 *  full H:4 packet that means extra STP header + length doesn't
                 *  indicate a full H:4 frame, things can fragment. Whose length
                 *  recorded in STP header just shows up the most length the
                 *  H:4 engine can handle currently.
                 */

                p_h4 = mtk_stp_split(bdev, p_left, sz_left, &sz_h4);
                if (!p_h4)
                        break;

                adv = p_h4 - p_left;
                sz_left -= adv;
                p_left += adv;

                bdev->rx_skb = h4_recv_buf(bdev->hdev, bdev->rx_skb, p_h4,
                                           sz_h4, mtk_recv_pkts,
                                           ARRAY_SIZE(mtk_recv_pkts));
                if (IS_ERR(bdev->rx_skb)) {
                        err = PTR_ERR(bdev->rx_skb);
                        bt_dev_err(bdev->hdev,
                                   "Frame reassembly failed (%d)", err);
                        bdev->rx_skb = NULL;
                        return err;
                }

                sz_left -= sz_h4;
                p_left += sz_h4;
        }

        return 0;
}

static int btmtkuart_receive_buf(struct serdev_device *serdev, const u8 *data,
                                 size_t count)
{
        struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
        int err;

        err = btmtkuart_recv(bdev->hdev, data, count);
        if (err < 0)
                return err;

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

        return count;
}

static void btmtkuart_write_wakeup(struct serdev_device *serdev)
{
        struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);

        btmtkuart_tx_wakeup(bdev);
}

static const struct serdev_device_ops btmtkuart_client_ops = {
        .receive_buf = btmtkuart_receive_buf,
        .write_wakeup = btmtkuart_write_wakeup,
};

static int btmtkuart_open(struct hci_dev *hdev)
{
        struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
        struct device *dev;
        int err;

        err = serdev_device_open(bdev->serdev);
        if (err) {
                bt_dev_err(hdev, "Unable to open UART device %s",
                           dev_name(&bdev->serdev->dev));
                goto err_open;
        }

        bdev->stp_cursor = 2;
        bdev->stp_dlen = 0;

        dev = &bdev->serdev->dev;

        /* Enable the power domain and clock the device requires */
        pm_runtime_enable(dev);
        err = pm_runtime_get_sync(dev);
        if (err < 0) {
                pm_runtime_put_noidle(dev);
                goto err_disable_rpm;
        }

        err = clk_prepare_enable(bdev->clk);
        if (err < 0)
                goto err_put_rpm;

        return 0;

err_put_rpm:
        pm_runtime_put_sync(dev);
err_disable_rpm:
        pm_runtime_disable(dev);
err_open:
        return err;
}

static int btmtkuart_close(struct hci_dev *hdev)
{
        struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
        struct device *dev = &bdev->serdev->dev;

        /* Shutdown the clock and power domain the device requires */
        clk_disable_unprepare(bdev->clk);
        pm_runtime_put_sync(dev);
        pm_runtime_disable(dev);

        serdev_device_close(bdev->serdev);

        return 0;
}

static int btmtkuart_flush(struct hci_dev *hdev)
{
        struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);

        /* Flush any pending characters */
        serdev_device_write_flush(bdev->serdev);
        skb_queue_purge(&bdev->txq);

        cancel_work_sync(&bdev->tx_work);

        kfree_skb(bdev->rx_skb);
        bdev->rx_skb = NULL;

        bdev->stp_cursor = 2;
        bdev->stp_dlen = 0;

        return 0;
}

static int btmtkuart_setup(struct hci_dev *hdev)
{
        u8 param = 0x1;
        int err = 0;

        /* Setup a firmware which the device definitely requires */
        err = mtk_setup_fw(hdev);
        if (err < 0)
                return err;

        /* Activate function the firmware providing to */
        err = mtk_hci_wmt_sync(hdev, MTK_WMT_RST, 0x4, 0, 0);
        if (err < 0) {
                bt_dev_err(hdev, "Failed to send wmt rst (%d)", err);
                return err;
        }

        /* Enable Bluetooth protocol */
        err = mtk_hci_wmt_sync(hdev, MTK_WMT_FUNC_CTRL, 0x0, sizeof(param),
                               &param);
        if (err < 0) {
                bt_dev_err(hdev, "Failed to send wmt func ctrl (%d)", err);
                return err;
        }

        return 0;
}

static int btmtkuart_shutdown(struct hci_dev *hdev)
{
        u8 param = 0x0;
        int err;

        /* Disable the device */
        err = mtk_hci_wmt_sync(hdev, MTK_WMT_FUNC_CTRL, 0x0, sizeof(param),
                               &param);
        if (err < 0) {
                bt_dev_err(hdev, "Failed to send wmt func ctrl (%d)", err);
                return err;
        }

        return 0;
}

static int btmtkuart_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
{
        struct btmtkuart_dev *bdev = hci_get_drvdata(hdev);
        struct mtk_stp_hdr *shdr;
        int err, dlen, type = 0;

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

        /* Make sure that there is enough rooms for STP header and trailer */
        if (unlikely(skb_headroom(skb) < sizeof(*shdr)) ||
            (skb_tailroom(skb) < MTK_STP_TLR_SIZE)) {
                err = pskb_expand_head(skb, sizeof(*shdr), MTK_STP_TLR_SIZE,
                                       GFP_ATOMIC);
                if (err < 0)
                        return err;
        }

        /* Add the STP header */
        dlen = skb->len;
        shdr = skb_push(skb, sizeof(*shdr));
        shdr->prefix = 0x80;
        shdr->dlen = cpu_to_be16((dlen & 0x0fff) | (type << 12));
        shdr->cs = 0;           /* MT7622 doesn't care about checksum value */

        /* Add the STP trailer */
        skb_put_zero(skb, MTK_STP_TLR_SIZE);

        skb_queue_tail(&bdev->txq, skb);

        btmtkuart_tx_wakeup(bdev);
        return 0;
}

static int btmtkuart_probe(struct serdev_device *serdev)
{
        struct btmtkuart_dev *bdev;
        struct hci_dev *hdev;

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

        bdev->clk = devm_clk_get(&serdev->dev, "ref");
        if (IS_ERR(bdev->clk))
                return PTR_ERR(bdev->clk);

        bdev->serdev = serdev;
        serdev_device_set_drvdata(serdev, bdev);

        serdev_device_set_client_ops(serdev, &btmtkuart_client_ops);

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

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

        bdev->hdev = hdev;

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

        hdev->open     = btmtkuart_open;
        hdev->close    = btmtkuart_close;
        hdev->flush    = btmtkuart_flush;
        hdev->setup    = btmtkuart_setup;
        hdev->shutdown = btmtkuart_shutdown;
        hdev->send     = btmtkuart_send_frame;
        SET_HCIDEV_DEV(hdev, &serdev->dev);

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

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

        return 0;
}

static void btmtkuart_remove(struct serdev_device *serdev)
{
        struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);
        struct hci_dev *hdev = bdev->hdev;

        hci_unregister_dev(hdev);
        hci_free_dev(hdev);
}

#ifdef CONFIG_OF
static const struct of_device_id mtk_of_match_table[] = {
        { .compatible = "mediatek,mt7622-bluetooth"},
        { }
};
MODULE_DEVICE_TABLE(of, mtk_of_match_table);
#endif

static struct serdev_device_driver btmtkuart_driver = {
        .probe = btmtkuart_probe,
        .remove = btmtkuart_remove,
        .driver = {
                .name = "btmtkuart",
                .of_match_table = of_match_ptr(mtk_of_match_table),
        },
};

module_serdev_device_driver(btmtkuart_driver);

MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
MODULE_DESCRIPTION("MediaTek Bluetooth Serial driver ver " VERSION);
MODULE_VERSION(VERSION);
MODULE_LICENSE("GPL");
MODULE_FIRMWARE(FIRMWARE_MT7622);