/*
 * Stuff used by all variants of the driver
 *
 * Copyright (c) 2001 by Stefan Eilers,
 *                       Hansjoerg Lipp <hjlipp@web.de>,
 *                       Tilman Schmidt <tilman@imap.cc>.
 *
 * =====================================================================
 *      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 of
 *      the License, or (at your option) any later version.
 * =====================================================================
 */

#include "gigaset.h"

/* == Handling of I4L IO =====================================================*/

/* writebuf_from_LL
 * called by LL to transmit data on an open channel
 * inserts the buffer data into the send queue and starts the transmission
 * Note that this operation must not sleep!
 * When the buffer is processed completely, gigaset_skb_sent() should be called.
 * parameters:
 *      driverID        driver ID as assigned by LL
 *      channel         channel number
 *      ack             if != 0 LL wants to be notified on completion via
 *                      statcallb(ISDN_STAT_BSENT)
 *      skb             skb containing data to send
 * return value:
 *      number of accepted bytes
 *      0 if temporarily unable to accept data (out of buffer space)
 *      <0 on error (eg. -EINVAL)
 */
static int writebuf_from_LL(int driverID, int channel, int ack,
                            struct sk_buff *skb)
{
        struct cardstate *cs;
        struct bc_state *bcs;
        unsigned len;
        unsigned skblen;

        if (!(cs = gigaset_get_cs_by_id(driverID))) {
                pr_err("%s: invalid driver ID (%d)\n", __func__, driverID);
                return -ENODEV;
        }
        if (channel < 0 || channel >= cs->channels) {
                dev_err(cs->dev, "%s: invalid channel ID (%d)\n",
                        __func__, channel);
                return -ENODEV;
        }
        bcs = &cs->bcs[channel];

        /* can only handle linear sk_buffs */
        if (skb_linearize(skb) < 0) {
                dev_err(cs->dev, "%s: skb_linearize failed\n", __func__);
                return -ENOMEM;
        }
        len = skb->len;

        gig_dbg(DEBUG_LLDATA,
                "Receiving data from LL (id: %d, ch: %d, ack: %d, sz: %d)",
                driverID, channel, ack, len);

        if (!len) {
                if (ack)
                        dev_notice(cs->dev, "%s: not ACKing empty packet\n",
                                   __func__);
                return 0;
        }
        if (len > MAX_BUF_SIZE) {
                dev_err(cs->dev, "%s: packet too large (%d bytes)\n",
                        __func__, len);
                return -EINVAL;
        }

        skblen = ack ? len : 0;
        skb->head[0] = skblen & 0xff;
        skb->head[1] = skblen >> 8;
        gig_dbg(DEBUG_MCMD, "skb: len=%u, skblen=%u: %02x %02x",
                len, skblen, (unsigned) skb->head[0], (unsigned) skb->head[1]);

        /* pass to device-specific module */
        return cs->ops->send_skb(bcs, skb);
}

/**
 * gigaset_skb_sent() - acknowledge sending an skb
 * @bcs:        B channel descriptor structure.
 * @skb:        sent data.
 *
 * Called by hardware module {bas,ser,usb}_gigaset when the data in a
 * skb has been successfully sent, for signalling completion to the LL.
 */
void gigaset_skb_sent(struct bc_state *bcs, struct sk_buff *skb)
{
        unsigned len;
        isdn_ctrl response;

        ++bcs->trans_up;

        if (skb->len)
                dev_warn(bcs->cs->dev, "%s: skb->len==%d\n",
                         __func__, skb->len);

        len = (unsigned char) skb->head[0] |
              (unsigned) (unsigned char) skb->head[1] << 8;
        if (len) {
                gig_dbg(DEBUG_MCMD, "ACKing to LL (id: %d, ch: %d, sz: %u)",
                        bcs->cs->myid, bcs->channel, len);

                response.driver = bcs->cs->myid;
                response.command = ISDN_STAT_BSENT;
                response.arg = bcs->channel;
                response.parm.length = len;
                bcs->cs->iif.statcallb(&response);
        }
}
EXPORT_SYMBOL_GPL(gigaset_skb_sent);

/* This function will be called by LL to send commands
 * NOTE: LL ignores the returned value, for commands other than ISDN_CMD_IOCTL,
 * so don't put too much effort into it.
 */
static int command_from_LL(isdn_ctrl *cntrl)
{
        struct cardstate *cs = gigaset_get_cs_by_id(cntrl->driver);
        struct bc_state *bcs;
        int retval = 0;
        struct setup_parm *sp;

        gigaset_debugdrivers();

        if (!cs) {
                pr_err("%s: invalid driver ID (%d)\n", __func__, cntrl->driver);
                return -ENODEV;
        }

        switch (cntrl->command) {
        case ISDN_CMD_IOCTL:
                gig_dbg(DEBUG_ANY, "ISDN_CMD_IOCTL (driver: %d, arg: %ld)",
                        cntrl->driver, cntrl->arg);

                dev_warn(cs->dev, "ISDN_CMD_IOCTL not supported\n");
                return -EINVAL;

        case ISDN_CMD_DIAL:
                gig_dbg(DEBUG_ANY,
                        "ISDN_CMD_DIAL (driver: %d, ch: %ld, "
                        "phone: %s, ownmsn: %s, si1: %d, si2: %d)",
                        cntrl->driver, cntrl->arg,
                        cntrl->parm.setup.phone, cntrl->parm.setup.eazmsn,
                        cntrl->parm.setup.si1, cntrl->parm.setup.si2);

                if (cntrl->arg >= cs->channels) {
                        dev_err(cs->dev,
                                "ISDN_CMD_DIAL: invalid channel (%d)\n",
                                (int) cntrl->arg);
                        return -EINVAL;
                }

                bcs = cs->bcs + cntrl->arg;

                if (!gigaset_get_channel(bcs)) {
                        dev_err(cs->dev, "ISDN_CMD_DIAL: channel not free\n");
                        return -EBUSY;
                }

                sp = kmalloc(sizeof *sp, GFP_ATOMIC);
                if (!sp) {
                        gigaset_free_channel(bcs);
                        dev_err(cs->dev, "ISDN_CMD_DIAL: out of memory\n");
                        return -ENOMEM;
                }
                *sp = cntrl->parm.setup;

                if (!gigaset_add_event(cs, &bcs->at_state, EV_DIAL, sp,
                                       bcs->at_state.seq_index, NULL)) {
                        //FIXME what should we do?
                        kfree(sp);
                        gigaset_free_channel(bcs);
                        return -ENOMEM;
                }

                gig_dbg(DEBUG_CMD, "scheduling DIAL");
                gigaset_schedule_event(cs);
                break;
        case ISDN_CMD_ACCEPTD: //FIXME
                gig_dbg(DEBUG_ANY, "ISDN_CMD_ACCEPTD");

                if (cntrl->arg >= cs->channels) {
                        dev_err(cs->dev,
                                "ISDN_CMD_ACCEPTD: invalid channel (%d)\n",
                                (int) cntrl->arg);
                        return -EINVAL;
                }

                if (!gigaset_add_event(cs, &cs->bcs[cntrl->arg].at_state,
                                       EV_ACCEPT, NULL, 0, NULL)) {
                        //FIXME what should we do?
                        return -ENOMEM;
                }

                gig_dbg(DEBUG_CMD, "scheduling ACCEPT");
                gigaset_schedule_event(cs);

                break;
        case ISDN_CMD_ACCEPTB:
                gig_dbg(DEBUG_ANY, "ISDN_CMD_ACCEPTB");
                break;
        case ISDN_CMD_HANGUP:
                gig_dbg(DEBUG_ANY, "ISDN_CMD_HANGUP (ch: %d)",
                        (int) cntrl->arg);

                if (cntrl->arg >= cs->channels) {
                        dev_err(cs->dev,
                                "ISDN_CMD_HANGUP: invalid channel (%d)\n",
                                (int) cntrl->arg);
                        return -EINVAL;
                }

                if (!gigaset_add_event(cs, &cs->bcs[cntrl->arg].at_state,
                                       EV_HUP, NULL, 0, NULL)) {
                        //FIXME what should we do?
                        return -ENOMEM;
                }

                gig_dbg(DEBUG_CMD, "scheduling HUP");
                gigaset_schedule_event(cs);

                break;
        case ISDN_CMD_CLREAZ: /* Do not signal incoming signals */ //FIXME
                gig_dbg(DEBUG_ANY, "ISDN_CMD_CLREAZ");
                break;
        case ISDN_CMD_SETEAZ: /* Signal incoming calls for given MSN */ //FIXME
                gig_dbg(DEBUG_ANY,
                        "ISDN_CMD_SETEAZ (id: %d, ch: %ld, number: %s)",
                        cntrl->driver, cntrl->arg, cntrl->parm.num);
                break;
        case ISDN_CMD_SETL2: /* Set L2 to given protocol */
                gig_dbg(DEBUG_ANY, "ISDN_CMD_SETL2 (ch: %ld, proto: %lx)",
                        cntrl->arg & 0xff, (cntrl->arg >> 8));

                if ((cntrl->arg & 0xff) >= cs->channels) {
                        dev_err(cs->dev,
                                "ISDN_CMD_SETL2: invalid channel (%d)\n",
                                (int) cntrl->arg & 0xff);
                        return -EINVAL;
                }

                if (!gigaset_add_event(cs, &cs->bcs[cntrl->arg & 0xff].at_state,
                                       EV_PROTO_L2, NULL, cntrl->arg >> 8,
                                       NULL)) {
                        //FIXME what should we do?
                        return -ENOMEM;
                }

                gig_dbg(DEBUG_CMD, "scheduling PROTO_L2");
                gigaset_schedule_event(cs);
                break;
        case ISDN_CMD_SETL3: /* Set L3 to given protocol */
                gig_dbg(DEBUG_ANY, "ISDN_CMD_SETL3 (ch: %ld, proto: %lx)",
                        cntrl->arg & 0xff, (cntrl->arg >> 8));

                if ((cntrl->arg & 0xff) >= cs->channels) {
                        dev_err(cs->dev,
                                "ISDN_CMD_SETL3: invalid channel (%d)\n",
                                (int) cntrl->arg & 0xff);
                        return -EINVAL;
                }

                if (cntrl->arg >> 8 != ISDN_PROTO_L3_TRANS) {
                        dev_err(cs->dev,
                                "ISDN_CMD_SETL3: invalid protocol %lu\n",
                                cntrl->arg >> 8);
                        return -EINVAL;
                }

                break;
        case ISDN_CMD_PROCEED:
                gig_dbg(DEBUG_ANY, "ISDN_CMD_PROCEED"); //FIXME
                break;
        case ISDN_CMD_ALERT:
                gig_dbg(DEBUG_ANY, "ISDN_CMD_ALERT"); //FIXME
                if (cntrl->arg >= cs->channels) {
                        dev_err(cs->dev,
                                "ISDN_CMD_ALERT: invalid channel (%d)\n",
                                (int) cntrl->arg);
                        return -EINVAL;
                }
                //bcs = cs->bcs + cntrl->arg;
                //bcs->proto2 = -1;
                // FIXME
                break;
        case ISDN_CMD_REDIR:
                gig_dbg(DEBUG_ANY, "ISDN_CMD_REDIR"); //FIXME
                break;
        case ISDN_CMD_PROT_IO:
                gig_dbg(DEBUG_ANY, "ISDN_CMD_PROT_IO");
                break;
        case ISDN_CMD_FAXCMD:
                gig_dbg(DEBUG_ANY, "ISDN_CMD_FAXCMD");
                break;
        case ISDN_CMD_GETL2:
                gig_dbg(DEBUG_ANY, "ISDN_CMD_GETL2");
                break;
        case ISDN_CMD_GETL3:
                gig_dbg(DEBUG_ANY, "ISDN_CMD_GETL3");
                break;
        case ISDN_CMD_GETEAZ:
                gig_dbg(DEBUG_ANY, "ISDN_CMD_GETEAZ");
                break;
        case ISDN_CMD_SETSIL:
                gig_dbg(DEBUG_ANY, "ISDN_CMD_SETSIL");
                break;
        case ISDN_CMD_GETSIL:
                gig_dbg(DEBUG_ANY, "ISDN_CMD_GETSIL");
                break;
        default:
                dev_err(cs->dev, "unknown command %d from LL\n",
                        cntrl->command);
                return -EINVAL;
        }

        return retval;
}

void gigaset_i4l_cmd(struct cardstate *cs, int cmd)
{
        isdn_ctrl command;

        command.driver = cs->myid;
        command.command = cmd;
        command.arg = 0;
        cs->iif.statcallb(&command);
}

void gigaset_i4l_channel_cmd(struct bc_state *bcs, int cmd)
{
        isdn_ctrl command;

        command.driver = bcs->cs->myid;
        command.command = cmd;
        command.arg = bcs->channel;
        bcs->cs->iif.statcallb(&command);
}

int gigaset_isdn_setup_dial(struct at_state_t *at_state, void *data)
{
        struct bc_state *bcs = at_state->bcs;
        unsigned proto;
        const char *bc;
        size_t length[AT_NUM];
        size_t l;
        int i;
        struct setup_parm *sp = data;

        switch (bcs->proto2) {
        case ISDN_PROTO_L2_HDLC:
                proto = 1; /* 0: Bitsynchron, 1: HDLC, 2: voice */
                break;
        case ISDN_PROTO_L2_TRANS:
                proto = 2; /* 0: Bitsynchron, 1: HDLC, 2: voice */
                break;
        default:
                dev_err(bcs->cs->dev, "%s: invalid L2 protocol: %u\n",
                        __func__, bcs->proto2);
                return -EINVAL;
        }

        switch (sp->si1) {
        case 1:         /* audio */
                bc = "9090A3";  /* 3.1 kHz audio, A-law */
                break;
        case 7:         /* data */
        default:        /* hope the app knows what it is doing */
                bc = "8890";    /* unrestricted digital information */
        }
        //FIXME add missing si1 values from 1TR6, inspect si2, set HLC/LLC

        length[AT_DIAL ] = 1 + strlen(sp->phone) + 1 + 1;
        l = strlen(sp->eazmsn);
        length[AT_MSN  ] = l ? 6 + l + 1 + 1 : 0;
        length[AT_BC   ] = 5 + strlen(bc) + 1 + 1;
        length[AT_PROTO] = 6 + 1 + 1 + 1; /* proto: 1 character */
        length[AT_ISO  ] = 6 + 1 + 1 + 1; /* channel: 1 character */
        length[AT_TYPE ] = 6 + 1 + 1 + 1; /* call type: 1 character */
        length[AT_HLC  ] = 0;

        for (i = 0; i < AT_NUM; ++i) {
                kfree(bcs->commands[i]);
                bcs->commands[i] = NULL;
                if (length[i] &&
                    !(bcs->commands[i] = kmalloc(length[i], GFP_ATOMIC))) {
                        dev_err(bcs->cs->dev, "out of memory\n");
                        return -ENOMEM;
                }
        }

        /* type = 1: extern, 0: intern, 2: recall, 3: door, 4: centrex */
        if (sp->phone[0] == '*' && sp->phone[1] == '*') {
                /* internal call: translate ** prefix to CTP value */
                snprintf(bcs->commands[AT_DIAL], length[AT_DIAL],
                         "D%s\r", sp->phone+2);
                strncpy(bcs->commands[AT_TYPE], "^SCTP=0\r", length[AT_TYPE]);
        } else {
                snprintf(bcs->commands[AT_DIAL], length[AT_DIAL],
                         "D%s\r", sp->phone);
                strncpy(bcs->commands[AT_TYPE], "^SCTP=1\r", length[AT_TYPE]);
        }

        if (bcs->commands[AT_MSN])
                snprintf(bcs->commands[AT_MSN], length[AT_MSN],
                         "^SMSN=%s\r", sp->eazmsn);
        snprintf(bcs->commands[AT_BC   ], length[AT_BC   ],
                 "^SBC=%s\r", bc);
        snprintf(bcs->commands[AT_PROTO], length[AT_PROTO],
                 "^SBPR=%u\r", proto);
        snprintf(bcs->commands[AT_ISO  ], length[AT_ISO  ],
                 "^SISO=%u\r", (unsigned)bcs->channel + 1);

        return 0;
}

int gigaset_isdn_setup_accept(struct at_state_t *at_state)
{
        unsigned proto;
        size_t length[AT_NUM];
        int i;
        struct bc_state *bcs = at_state->bcs;

        switch (bcs->proto2) {
        case ISDN_PROTO_L2_HDLC:
                proto = 1; /* 0: Bitsynchron, 1: HDLC, 2: voice */
                break;
        case ISDN_PROTO_L2_TRANS:
                proto = 2; /* 0: Bitsynchron, 1: HDLC, 2: voice */
                break;
        default:
                dev_err(at_state->cs->dev, "%s: invalid protocol: %u\n",
                        __func__, bcs->proto2);
                return -EINVAL;
        }

        length[AT_DIAL ] = 0;
        length[AT_MSN  ] = 0;
        length[AT_BC   ] = 0;
        length[AT_PROTO] = 6 + 1 + 1 + 1; /* proto: 1 character */
        length[AT_ISO  ] = 6 + 1 + 1 + 1; /* channel: 1 character */
        length[AT_TYPE ] = 0;
        length[AT_HLC  ] = 0;

        for (i = 0; i < AT_NUM; ++i) {
                kfree(bcs->commands[i]);
                bcs->commands[i] = NULL;
                if (length[i] &&
                    !(bcs->commands[i] = kmalloc(length[i], GFP_ATOMIC))) {
                        dev_err(at_state->cs->dev, "out of memory\n");
                        return -ENOMEM;
                }
        }

        snprintf(bcs->commands[AT_PROTO], length[AT_PROTO],
                 "^SBPR=%u\r", proto);
        snprintf(bcs->commands[AT_ISO  ], length[AT_ISO  ],
                 "^SISO=%u\r", (unsigned) bcs->channel + 1);

        return 0;
}

/**
 * gigaset_isdn_icall() - signal incoming call
 * @at_state:   connection state structure.
 *
 * Called by main module to notify the LL that an incoming call has been
 * received. @at_state contains the parameters of the call.
 *
 * Return value: call disposition (ICALL_*)
 */
int gigaset_isdn_icall(struct at_state_t *at_state)
{
        struct cardstate *cs = at_state->cs;
        struct bc_state *bcs = at_state->bcs;
        isdn_ctrl response;
        int retval;

        /* fill ICALL structure */
        response.parm.setup.si1 = 0;    /* default: unknown */
        response.parm.setup.si2 = 0;
        response.parm.setup.screen = 0; //FIXME how to set these?
        response.parm.setup.plan = 0;
        if (!at_state->str_var[STR_ZBC]) {
                /* no BC (internal call): assume speech, A-law */
                response.parm.setup.si1 = 1;
        } else if (!strcmp(at_state->str_var[STR_ZBC], "8890")) {
                /* unrestricted digital information */
                response.parm.setup.si1 = 7;
        } else if (!strcmp(at_state->str_var[STR_ZBC], "8090A3")) {
                /* speech, A-law */
                response.parm.setup.si1 = 1;
        } else if (!strcmp(at_state->str_var[STR_ZBC], "9090A3")) {
                /* 3,1 kHz audio, A-law */
                response.parm.setup.si1 = 1;
                response.parm.setup.si2 = 2;
        } else {
                dev_warn(cs->dev, "RING ignored - unsupported BC %s\n",
                     at_state->str_var[STR_ZBC]);
                return ICALL_IGNORE;
        }
        if (at_state->str_var[STR_NMBR]) {
                strncpy(response.parm.setup.phone, at_state->str_var[STR_NMBR],
                        sizeof response.parm.setup.phone - 1);
                response.parm.setup.phone[sizeof response.parm.setup.phone - 1] = 0;
        } else
                response.parm.setup.phone[0] = 0;
        if (at_state->str_var[STR_ZCPN]) {
                strncpy(response.parm.setup.eazmsn, at_state->str_var[STR_ZCPN],
                        sizeof response.parm.setup.eazmsn - 1);
                response.parm.setup.eazmsn[sizeof response.parm.setup.eazmsn - 1] = 0;
        } else
                response.parm.setup.eazmsn[0] = 0;

        if (!bcs) {
                dev_notice(cs->dev, "no channel for incoming call\n");
                response.command = ISDN_STAT_ICALLW;
                response.arg = 0; //FIXME
        } else {
                gig_dbg(DEBUG_CMD, "Sending ICALL");
                response.command = ISDN_STAT_ICALL;
                response.arg = bcs->channel; //FIXME
        }
        response.driver = cs->myid;
        retval = cs->iif.statcallb(&response);
        gig_dbg(DEBUG_CMD, "Response: %d", retval);
        switch (retval) {
        case 0: /* no takers */
                return ICALL_IGNORE;
        case 1: /* alerting */
                bcs->chstate |= CHS_NOTIFY_LL;
                return ICALL_ACCEPT;
        case 2: /* reject */
                return ICALL_REJECT;
        case 3: /* incomplete */
                dev_warn(cs->dev,
                       "LL requested unsupported feature: Incomplete Number\n");
                return ICALL_IGNORE;
        case 4: /* proceeding */
                /* Gigaset will send ALERTING anyway.
                 * There doesn't seem to be a way to avoid this.
                 */
                return ICALL_ACCEPT;
        case 5: /* deflect */
                dev_warn(cs->dev,
                         "LL requested unsupported feature: Call Deflection\n");
                return ICALL_IGNORE;
        default:
                dev_err(cs->dev, "LL error %d on ICALL\n", retval);
                return ICALL_IGNORE;
        }
}

/* Set Callback function pointer */
int gigaset_register_to_LL(struct cardstate *cs, const char *isdnid)
{
        isdn_if *iif = &cs->iif;

        gig_dbg(DEBUG_ANY, "Register driver capabilities to LL");

        if (snprintf(iif->id, sizeof iif->id, "%s_%u", isdnid, cs->minor_index)
            >= sizeof iif->id) {
                pr_err("ID too long: %s\n", isdnid);
                return 0;
        }

        iif->owner = THIS_MODULE;
        iif->channels = cs->channels;
        iif->maxbufsize = MAX_BUF_SIZE;
        iif->features = ISDN_FEATURE_L2_TRANS |
                ISDN_FEATURE_L2_HDLC |
#ifdef GIG_X75
                ISDN_FEATURE_L2_X75I |
#endif
                ISDN_FEATURE_L3_TRANS |
                ISDN_FEATURE_P_EURO;
        iif->hl_hdrlen = HW_HDR_LEN;            /* Area for storing ack */
        iif->command = command_from_LL;
        iif->writebuf_skb = writebuf_from_LL;
        iif->writecmd = NULL;                   /* Don't support isdnctrl */
        iif->readstat = NULL;                   /* Don't support isdnctrl */
        iif->rcvcallb_skb = NULL;               /* Will be set by LL */
        iif->statcallb = NULL;                  /* Will be set by LL */

        if (!register_isdn(iif)) {
                pr_err("register_isdn failed\n");
                return 0;
        }

        cs->myid = iif->channels;               /* Set my device id */
        return 1;
}