/*

 * Bluetooth serial HCI transport.

 * CSR41814 HCI with H4p vendor extensions.

 *

 * Copyright (C) 2008 Andrzej Zaborowski  <balrog@zabor.org>

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License as

 * published by the Free Software Foundation; either version 2 or

 * (at your option) version 3 of the License.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,

 * MA 02111-1307 USA

 */

#include "qemu-common.h"

#include "qemu-char.h"

#include "qemu-timer.h"

#include "irq.h"

#include "sysemu.h"

#include "net.h"

#include "bt.h"

struct csrhci_s {

    int enable;

    qemu_irq *pins;

    int pin_state;

    int modem_state;

    CharDriverState chr;

#define FIFO_LEN	4096

    int out_start;

    int out_len;

    int out_size;

    uint8_t outfifo[FIFO_LEN * 2];

    uint8_t inpkt[FIFO_LEN];

    int in_len;

    int in_hdr;

    int in_data;

    QEMUTimer *out_tm;

    int64_t baud_delay;

    bdaddr_t bd_addr;

    struct HCIInfo *hci;

};

/* H4+ packet types */

enum {

    H4_CMD_PKT   = 1,

    H4_ACL_PKT   = 2,

    H4_SCO_PKT   = 3,

    H4_EVT_PKT   = 4,

    H4_NEG_PKT   = 6,

    H4_ALIVE_PKT = 7,

};

/* CSR41814 negotiation start magic packet */

static const uint8_t csrhci_neg_packet[] = {

    H4_NEG_PKT, 10,

    0x00, 0xa0, 0x01, 0x00, 0x00,

    0x4c, 0x00, 0x96, 0x00, 0x00,

};

/* CSR41814 vendor-specific command OCFs */

enum {

    OCF_CSR_SEND_FIRMWARE = 0x000,

};

static inline void csrhci_fifo_wake(struct csrhci_s *s)

{

    if (!s->enable || !s->out_len)

        return;

    /* XXX: Should wait for s->modem_state & CHR_TIOCM_RTS? */

    if (s->chr.chr_can_read && s->chr.chr_can_read(s->chr.handler_opaque) &&

                    s->chr.chr_read) {

        s->chr.chr_read(s->chr.handler_opaque,

                        s->outfifo + s->out_start ++, 1);

        s->out_len --;

        if (s->out_start >= s->out_size) {

            s->out_start = 0;

            s->out_size = FIFO_LEN;

        }

    }

    if (s->out_len)

        qemu_mod_timer(s->out_tm, qemu_get_clock(vm_clock) + s->baud_delay);

}

#define csrhci_out_packetz(s, len) memset(csrhci_out_packet(s, len), 0, len)

static uint8_t *csrhci_out_packet(struct csrhci_s *s, int len)

{

    int off = s->out_start + s->out_len;

    /* TODO: do the padding here, i.e. align len */

    s->out_len += len;

    if (off < FIFO_LEN) {

        if (off + len > FIFO_LEN && (s->out_size = off + len) > FIFO_LEN * 2) {

            fprintf(stderr, "%s: can't alloc %i bytes\n", __FUNCTION__, len);

            exit(-1);

        }

        return s->outfifo + off;

    }

    if (s->out_len > s->out_size) {

        fprintf(stderr, "%s: can't alloc %i bytes\n", __FUNCTION__, len);

        exit(-1);

    }

    return s->outfifo + off - s->out_size;

}

static inline uint8_t *csrhci_out_packet_csr(struct csrhci_s *s,

                int type, int len)

{

    uint8_t *ret = csrhci_out_packetz(s, len + 2);

    *ret ++ = type;

    *ret ++ = len;

    return ret;

}

static inline uint8_t *csrhci_out_packet_event(struct csrhci_s *s,

                int evt, int len)

{

    uint8_t *ret = csrhci_out_packetz(s,

                    len + 1 + sizeof(struct hci_event_hdr));

    *ret ++ = H4_EVT_PKT;

    ((struct hci_event_hdr *) ret)->evt = evt;

    ((struct hci_event_hdr *) ret)->plen = len;

    return ret + sizeof(struct hci_event_hdr);

}

static void csrhci_in_packet_vendor(struct csrhci_s *s, int ocf,

                uint8_t *data, int len)

{

    int offset;

    uint8_t *rpkt;

    switch (ocf) {

    case OCF_CSR_SEND_FIRMWARE:

        /* Check if this is the bd_address packet */

        if (len >= 18 + 8 && data[12] == 0x01 && data[13] == 0x00) {

            offset = 18;

            s->bd_addr.b[0] = data[offset + 7];	/* Beyond cmd packet end(!?) */

            s->bd_addr.b[1] = data[offset + 6];

            s->bd_addr.b[2] = data[offset + 4];

            s->bd_addr.b[3] = data[offset + 0];

            s->bd_addr.b[4] = data[offset + 3];

            s->bd_addr.b[5] = data[offset + 2];

            s->hci->bdaddr_set(s->hci, s->bd_addr.b);

            fprintf(stderr, "%s: bd_address loaded from firmware: "

                            "%02x:%02x:%02x:%02x:%02x:%02x\n", __FUNCTION__,

                            s->bd_addr.b[0], s->bd_addr.b[1], s->bd_addr.b[2],

                            s->bd_addr.b[3], s->bd_addr.b[4], s->bd_addr.b[5]);

        }

        rpkt = csrhci_out_packet_event(s, EVT_VENDOR, 11);

        /* Status bytes: no error */

        rpkt[9] = 0x00;

        rpkt[10] = 0x00;

        break;

    default:

        fprintf(stderr, "%s: got a bad CMD packet\n", __FUNCTION__);

        return;

    }

    csrhci_fifo_wake(s);

}

static void csrhci_in_packet(struct csrhci_s *s, uint8_t *pkt)

{

    uint8_t *rpkt;

    int opc;

    switch (*pkt ++) {

    case H4_CMD_PKT:

        opc = le16_to_cpu(((struct hci_command_hdr *) pkt)->opcode);

        if (cmd_opcode_ogf(opc) == OGF_VENDOR_CMD) {

            csrhci_in_packet_vendor(s, cmd_opcode_ocf(opc),

                            pkt + sizeof(struct hci_command_hdr),

                            s->in_len - sizeof(struct hci_command_hdr) - 1);

            return;

        }

        /* TODO: if the command is OCF_READ_LOCAL_COMMANDS or the likes,

         * we need to send it to the HCI layer and then add our supported

         * commands to the returned mask (such as OGF_VENDOR_CMD).  With

         * bt-hci.c we could just have hooks for this kind of commands but

         * we can't with bt-host.c.  */

        s->hci->cmd_send(s->hci, pkt, s->in_len - 1);

        break;

    case H4_EVT_PKT:

        goto bad_pkt;

    case H4_ACL_PKT:

        s->hci->acl_send(s->hci, pkt, s->in_len - 1);

        break;

    case H4_SCO_PKT:

        s->hci->sco_send(s->hci, pkt, s->in_len - 1);

        break;

    case H4_NEG_PKT:

        if (s->in_hdr != sizeof(csrhci_neg_packet) ||

                        memcmp(pkt - 1, csrhci_neg_packet, s->in_hdr)) {

            fprintf(stderr, "%s: got a bad NEG packet\n", __FUNCTION__);

            return;

        }

        pkt += 2;

        rpkt = csrhci_out_packet_csr(s, H4_NEG_PKT, 10);

        *rpkt ++ = 0x20;	/* Operational settings negotation Ok */

        memcpy(rpkt, pkt, 7); rpkt += 7;

        *rpkt ++ = 0xff;

        *rpkt ++ = 0xff;

        break;

    case H4_ALIVE_PKT:

        if (s->in_hdr != 4 || pkt[1] != 0x55 || pkt[2] != 0x00) {

            fprintf(stderr, "%s: got a bad ALIVE packet\n", __FUNCTION__);

            return;

        }

        rpkt = csrhci_out_packet_csr(s, H4_ALIVE_PKT, 2);

        *rpkt ++ = 0xcc;

        *rpkt ++ = 0x00;

        break;

    default:

    bad_pkt:

        /* TODO: error out */

        fprintf(stderr, "%s: got a bad packet\n", __FUNCTION__);

        break;

    }

    csrhci_fifo_wake(s);

}

static int csrhci_header_len(const uint8_t *pkt)

{

    switch (pkt[0]) {

    case H4_CMD_PKT:

        return HCI_COMMAND_HDR_SIZE;

    case H4_EVT_PKT:

        return HCI_EVENT_HDR_SIZE;

    case H4_ACL_PKT:

        return HCI_ACL_HDR_SIZE;

    case H4_SCO_PKT:

        return HCI_SCO_HDR_SIZE;

    case H4_NEG_PKT:

        return pkt[1] + 1;

    case H4_ALIVE_PKT:

        return 3;

    }

    exit(-1);

}

static int csrhci_data_len(const uint8_t *pkt)

{

    switch (*pkt ++) {

    case H4_CMD_PKT:

        /* It seems that vendor-specific command packets for H4+ are all

         * one byte longer than indicated in the standard header.  */

        if (le16_to_cpu(((struct hci_command_hdr *) pkt)->opcode) == 0xfc00)

            return (((struct hci_command_hdr *) pkt)->plen + 1) & ~1;

        return ((struct hci_command_hdr *) pkt)->plen;

    case H4_EVT_PKT:

        return ((struct hci_event_hdr *) pkt)->plen;

    case H4_ACL_PKT:

        return le16_to_cpu(((struct hci_acl_hdr *) pkt)->dlen);

    case H4_SCO_PKT:

        return ((struct hci_sco_hdr *) pkt)->dlen;

    case H4_NEG_PKT:

    case H4_ALIVE_PKT:

        return 0;

    }

    exit(-1);

}

static int csrhci_write(struct CharDriverState *chr,

                const uint8_t *buf, int len)

{

    struct csrhci_s *s = (struct csrhci_s *) chr->opaque;

    int plen = s->in_len;

    if (!s->enable)

        return 0;

    s->in_len += len;

    memcpy(s->inpkt + plen, buf, len);

    while (1) {

        if (s->in_len >= 2 && plen < 2)

            s->in_hdr = csrhci_header_len(s->inpkt) + 1;

        if (s->in_len >= s->in_hdr && plen < s->in_hdr)

            s->in_data = csrhci_data_len(s->inpkt) + s->in_hdr;

        if (s->in_len >= s->in_data) {

            csrhci_in_packet(s, s->inpkt);

            memmove(s->inpkt, s->inpkt + s->in_len, s->in_len - s->in_data);

            s->in_len -= s->in_data;

            s->in_hdr = INT_MAX;

            s->in_data = INT_MAX;

            plen = 0;

        } else

            break;

    }

    return len;

}

static void csrhci_out_hci_packet_event(void *opaque,

                const uint8_t *data, int len)

{

    struct csrhci_s *s = (struct csrhci_s *) opaque;

    uint8_t *pkt = csrhci_out_packet(s, (len + 2) & ~1);	/* Align */

    *pkt ++ = H4_EVT_PKT;

    memcpy(pkt, data, len);

    csrhci_fifo_wake(s);

}

static void csrhci_out_hci_packet_acl(void *opaque,

                const uint8_t *data, int len)

{

    struct csrhci_s *s = (struct csrhci_s *) opaque;

    uint8_t *pkt = csrhci_out_packet(s, (len + 2) & ~1);	/* Align */

    *pkt ++ = H4_ACL_PKT;

    pkt[len & ~1] = 0;

    memcpy(pkt, data, len);

    csrhci_fifo_wake(s);

}

static int csrhci_ioctl(struct CharDriverState *chr, int cmd, void *arg)

{

    QEMUSerialSetParams *ssp;

    struct csrhci_s *s = (struct csrhci_s *) chr->opaque;

    int prev_state = s->modem_state;

    switch (cmd) {

    case CHR_IOCTL_SERIAL_SET_PARAMS:

        ssp = (QEMUSerialSetParams *) arg;

        s->baud_delay = ticks_per_sec / ssp->speed;

        /* Moments later... (but shorter than 100ms) */

        s->modem_state |= CHR_TIOCM_CTS;

        break;

    case CHR_IOCTL_SERIAL_GET_TIOCM:

        *(int *) arg = s->modem_state;

        break;

    case CHR_IOCTL_SERIAL_SET_TIOCM:

        s->modem_state = *(int *) arg;

        if (~s->modem_state & prev_state & CHR_TIOCM_RTS)

            s->modem_state &= ~CHR_TIOCM_CTS;

        break;

    default:

        return -ENOTSUP;

    }

    return 0;

}

static void csrhci_reset(struct csrhci_s *s)

{

    s->out_len = 0;

    s->out_size = FIFO_LEN;

    s->in_len = 0;

    s->baud_delay = ticks_per_sec;

    s->enable = 0;

    s->in_hdr = INT_MAX;

    s->in_data = INT_MAX;

    s->modem_state = 0;

    /* After a while... (but sooner than 10ms) */

    s->modem_state |= CHR_TIOCM_CTS;

    memset(&s->bd_addr, 0, sizeof(bdaddr_t));

}

static void csrhci_out_tick(void *opaque)

{

    csrhci_fifo_wake((struct csrhci_s *) opaque);

}

static void csrhci_pins(void *opaque, int line, int level)

{

    struct csrhci_s *s = (struct csrhci_s *) opaque;

    int state = s->pin_state;

    s->pin_state &= ~(1 << line);

    s->pin_state |= (!!level) << line;

    if ((state & ~s->pin_state) & (1 << csrhci_pin_reset)) {

        /* TODO: Disappear from lower layers */

        csrhci_reset(s);

    }

    if (s->pin_state == 3 && state != 3) {

        s->enable = 1;

        /* TODO: Wake lower layers up */

    }

}

qemu_irq *csrhci_pins_get(CharDriverState *chr)

{

    struct csrhci_s *s = (struct csrhci_s *) chr->opaque;

    return s->pins;

}

CharDriverState *uart_hci_init(qemu_irq wakeup)

{

    struct csrhci_s *s = (struct csrhci_s *)

            qemu_mallocz(sizeof(struct csrhci_s));

    s->chr.opaque = s;

    s->chr.chr_write = csrhci_write;

    s->chr.chr_ioctl = csrhci_ioctl;

    s->hci = qemu_next_hci();

    s->hci->opaque = s;

    s->hci->evt_recv = csrhci_out_hci_packet_event;

    s->hci->acl_recv = csrhci_out_hci_packet_acl;

    s->out_tm = qemu_new_timer(vm_clock, csrhci_out_tick, s);

    s->pins = qemu_allocate_irqs(csrhci_pins, s, __csrhci_pins);

    csrhci_reset(s);

    return &s->chr;

}