This commit was manufactured by cvs2svn to create branch 'vserver'.
[linux-2.6.git] / drivers / isdn / gigaset / common.c
diff --git a/drivers/isdn/gigaset/common.c b/drivers/isdn/gigaset/common.c
new file mode 100644 (file)
index 0000000..e55767b
--- /dev/null
@@ -0,0 +1,1233 @@
+/*
+ * 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"
+#include <linux/ctype.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+
+/* Version Information */
+#define DRIVER_AUTHOR "Hansjoerg Lipp <hjlipp@web.de>, Tilman Schmidt <tilman@imap.cc>, Stefan Eilers"
+#define DRIVER_DESC "Driver for Gigaset 307x"
+
+/* Module parameters */
+int gigaset_debuglevel = DEBUG_DEFAULT;
+EXPORT_SYMBOL_GPL(gigaset_debuglevel);
+module_param_named(debug, gigaset_debuglevel, int, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(debug, "debug level");
+
+/* driver state flags */
+#define VALID_MINOR    0x01
+#define VALID_ID       0x02
+#define ASSIGNED       0x04
+
+/* bitwise byte inversion table */
+__u8 gigaset_invtab[256] = {
+       0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0,
+       0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0,
+       0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8,
+       0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8,
+       0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4,
+       0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4,
+       0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec,
+       0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc,
+       0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2,
+       0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2,
+       0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea,
+       0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa,
+       0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6,
+       0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6,
+       0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee,
+       0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe,
+       0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1,
+       0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1,
+       0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9,
+       0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9,
+       0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5,
+       0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5,
+       0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed,
+       0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd,
+       0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3,
+       0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3,
+       0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb,
+       0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb,
+       0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7,
+       0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7,
+       0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef,
+       0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff
+};
+EXPORT_SYMBOL_GPL(gigaset_invtab);
+
+void gigaset_dbg_buffer(enum debuglevel level, const unsigned char *msg,
+                       size_t len, const unsigned char *buf)
+{
+       unsigned char outbuf[80];
+       unsigned char c;
+       size_t space = sizeof outbuf - 1;
+       unsigned char *out = outbuf;
+       size_t numin = len;
+
+       while (numin--) {
+               c = *buf++;
+               if (c == '~' || c == '^' || c == '\\') {
+                       if (!space--)
+                               break;
+                       *out++ = '\\';
+               }
+               if (c & 0x80) {
+                       if (!space--)
+                               break;
+                       *out++ = '~';
+                       c ^= 0x80;
+               }
+               if (c < 0x20 || c == 0x7f) {
+                       if (!space--)
+                               break;
+                       *out++ = '^';
+                       c ^= 0x40;
+               }
+               if (!space--)
+                       break;
+               *out++ = c;
+       }
+       *out = 0;
+
+       gig_dbg(level, "%s (%u bytes): %s", msg, (unsigned) len, outbuf);
+}
+EXPORT_SYMBOL_GPL(gigaset_dbg_buffer);
+
+static int setflags(struct cardstate *cs, unsigned flags, unsigned delay)
+{
+       int r;
+
+       r = cs->ops->set_modem_ctrl(cs, cs->control_state, flags);
+       cs->control_state = flags;
+       if (r < 0)
+               return r;
+
+       if (delay) {
+               set_current_state(TASK_INTERRUPTIBLE);
+               schedule_timeout(delay * HZ / 1000);
+       }
+
+       return 0;
+}
+
+int gigaset_enterconfigmode(struct cardstate *cs)
+{
+       int i, r;
+
+       cs->control_state = TIOCM_RTS; //FIXME
+
+       r = setflags(cs, TIOCM_DTR, 200);
+       if (r < 0)
+               goto error;
+       r = setflags(cs, 0, 200);
+       if (r < 0)
+               goto error;
+       for (i = 0; i < 5; ++i) {
+               r = setflags(cs, TIOCM_RTS, 100);
+               if (r < 0)
+                       goto error;
+               r = setflags(cs, 0, 100);
+               if (r < 0)
+                       goto error;
+       }
+       r = setflags(cs, TIOCM_RTS|TIOCM_DTR, 800);
+       if (r < 0)
+               goto error;
+
+       return 0;
+
+error:
+       dev_err(cs->dev, "error %d on setuartbits\n", -r);
+       cs->control_state = TIOCM_RTS|TIOCM_DTR; // FIXME is this a good value?
+       cs->ops->set_modem_ctrl(cs, 0, TIOCM_RTS|TIOCM_DTR);
+
+       return -1; //r
+}
+
+static int test_timeout(struct at_state_t *at_state)
+{
+       if (!at_state->timer_expires)
+               return 0;
+
+       if (--at_state->timer_expires) {
+               gig_dbg(DEBUG_MCMD, "decreased timer of %p to %lu",
+                       at_state, at_state->timer_expires);
+               return 0;
+       }
+
+       if (!gigaset_add_event(at_state->cs, at_state, EV_TIMEOUT, NULL,
+                              at_state->timer_index, NULL)) {
+               //FIXME what should we do?
+       }
+
+       return 1;
+}
+
+static void timer_tick(unsigned long data)
+{
+       struct cardstate *cs = (struct cardstate *) data;
+       unsigned long flags;
+       unsigned channel;
+       struct at_state_t *at_state;
+       int timeout = 0;
+
+       spin_lock_irqsave(&cs->lock, flags);
+
+       for (channel = 0; channel < cs->channels; ++channel)
+               if (test_timeout(&cs->bcs[channel].at_state))
+                       timeout = 1;
+
+       if (test_timeout(&cs->at_state))
+               timeout = 1;
+
+       list_for_each_entry(at_state, &cs->temp_at_states, list)
+               if (test_timeout(at_state))
+                       timeout = 1;
+
+       if (cs->running) {
+               mod_timer(&cs->timer, jiffies + msecs_to_jiffies(GIG_TICK));
+               if (timeout) {
+                       gig_dbg(DEBUG_CMD, "scheduling timeout");
+                       tasklet_schedule(&cs->event_tasklet);
+               }
+       }
+
+       spin_unlock_irqrestore(&cs->lock, flags);
+}
+
+int gigaset_get_channel(struct bc_state *bcs)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&bcs->cs->lock, flags);
+       if (bcs->use_count) {
+               gig_dbg(DEBUG_ANY, "could not allocate channel %d",
+                       bcs->channel);
+               spin_unlock_irqrestore(&bcs->cs->lock, flags);
+               return 0;
+       }
+       ++bcs->use_count;
+       bcs->busy = 1;
+       gig_dbg(DEBUG_ANY, "allocated channel %d", bcs->channel);
+       spin_unlock_irqrestore(&bcs->cs->lock, flags);
+       return 1;
+}
+
+void gigaset_free_channel(struct bc_state *bcs)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&bcs->cs->lock, flags);
+       if (!bcs->busy) {
+               gig_dbg(DEBUG_ANY, "could not free channel %d", bcs->channel);
+               spin_unlock_irqrestore(&bcs->cs->lock, flags);
+               return;
+       }
+       --bcs->use_count;
+       bcs->busy = 0;
+       gig_dbg(DEBUG_ANY, "freed channel %d", bcs->channel);
+       spin_unlock_irqrestore(&bcs->cs->lock, flags);
+}
+
+int gigaset_get_channels(struct cardstate *cs)
+{
+       unsigned long flags;
+       int i;
+
+       spin_lock_irqsave(&cs->lock, flags);
+       for (i = 0; i < cs->channels; ++i)
+               if (cs->bcs[i].use_count) {
+                       spin_unlock_irqrestore(&cs->lock, flags);
+                       gig_dbg(DEBUG_ANY, "could not allocate all channels");
+                       return 0;
+               }
+       for (i = 0; i < cs->channels; ++i)
+               ++cs->bcs[i].use_count;
+       spin_unlock_irqrestore(&cs->lock, flags);
+
+       gig_dbg(DEBUG_ANY, "allocated all channels");
+
+       return 1;
+}
+
+void gigaset_free_channels(struct cardstate *cs)
+{
+       unsigned long flags;
+       int i;
+
+       gig_dbg(DEBUG_ANY, "unblocking all channels");
+       spin_lock_irqsave(&cs->lock, flags);
+       for (i = 0; i < cs->channels; ++i)
+               --cs->bcs[i].use_count;
+       spin_unlock_irqrestore(&cs->lock, flags);
+}
+
+void gigaset_block_channels(struct cardstate *cs)
+{
+       unsigned long flags;
+       int i;
+
+       gig_dbg(DEBUG_ANY, "blocking all channels");
+       spin_lock_irqsave(&cs->lock, flags);
+       for (i = 0; i < cs->channels; ++i)
+               ++cs->bcs[i].use_count;
+       spin_unlock_irqrestore(&cs->lock, flags);
+}
+
+static void clear_events(struct cardstate *cs)
+{
+       struct event_t *ev;
+       unsigned head, tail;
+       unsigned long flags;
+
+       spin_lock_irqsave(&cs->ev_lock, flags);
+
+       head = cs->ev_head;
+       tail = cs->ev_tail;
+
+       while (tail != head) {
+               ev = cs->events + head;
+               kfree(ev->ptr);
+               head = (head + 1) % MAX_EVENTS;
+       }
+
+       cs->ev_head = tail;
+
+       spin_unlock_irqrestore(&cs->ev_lock, flags);
+}
+
+struct event_t *gigaset_add_event(struct cardstate *cs,
+                                 struct at_state_t *at_state, int type,
+                                 void *ptr, int parameter, void *arg)
+{
+       unsigned long flags;
+       unsigned next, tail;
+       struct event_t *event = NULL;
+
+       spin_lock_irqsave(&cs->ev_lock, flags);
+
+       tail = cs->ev_tail;
+       next = (tail + 1) % MAX_EVENTS;
+       if (unlikely(next == cs->ev_head))
+               err("event queue full");
+       else {
+               event = cs->events + tail;
+               event->type = type;
+               event->at_state = at_state;
+               event->cid = -1;
+               event->ptr = ptr;
+               event->arg = arg;
+               event->parameter = parameter;
+               cs->ev_tail = next;
+       }
+
+       spin_unlock_irqrestore(&cs->ev_lock, flags);
+
+       return event;
+}
+EXPORT_SYMBOL_GPL(gigaset_add_event);
+
+static void free_strings(struct at_state_t *at_state)
+{
+       int i;
+
+       for (i = 0; i < STR_NUM; ++i) {
+               kfree(at_state->str_var[i]);
+               at_state->str_var[i] = NULL;
+       }
+}
+
+static void clear_at_state(struct at_state_t *at_state)
+{
+       free_strings(at_state);
+}
+
+static void dealloc_at_states(struct cardstate *cs)
+{
+       struct at_state_t *cur, *next;
+
+       list_for_each_entry_safe(cur, next, &cs->temp_at_states, list) {
+               list_del(&cur->list);
+               free_strings(cur);
+               kfree(cur);
+       }
+}
+
+static void gigaset_freebcs(struct bc_state *bcs)
+{
+       int i;
+
+       gig_dbg(DEBUG_INIT, "freeing bcs[%d]->hw", bcs->channel);
+       if (!bcs->cs->ops->freebcshw(bcs)) {
+               gig_dbg(DEBUG_INIT, "failed");
+       }
+
+       gig_dbg(DEBUG_INIT, "clearing bcs[%d]->at_state", bcs->channel);
+       clear_at_state(&bcs->at_state);
+       gig_dbg(DEBUG_INIT, "freeing bcs[%d]->skb", bcs->channel);
+
+       if (bcs->skb)
+               dev_kfree_skb(bcs->skb);
+       for (i = 0; i < AT_NUM; ++i) {
+               kfree(bcs->commands[i]);
+               bcs->commands[i] = NULL;
+       }
+}
+
+static struct cardstate *alloc_cs(struct gigaset_driver *drv)
+{
+       unsigned long flags;
+       unsigned i;
+       static struct cardstate *ret = NULL;
+
+       spin_lock_irqsave(&drv->lock, flags);
+       for (i = 0; i < drv->minors; ++i) {
+               if (!(drv->flags[i] & VALID_MINOR)) {
+                       drv->flags[i] = VALID_MINOR;
+                       ret = drv->cs + i;
+               }
+               if (ret)
+                       break;
+       }
+       spin_unlock_irqrestore(&drv->lock, flags);
+       return ret;
+}
+
+static void free_cs(struct cardstate *cs)
+{
+       unsigned long flags;
+       struct gigaset_driver *drv = cs->driver;
+       spin_lock_irqsave(&drv->lock, flags);
+       drv->flags[cs->minor_index] = 0;
+       spin_unlock_irqrestore(&drv->lock, flags);
+}
+
+static void make_valid(struct cardstate *cs, unsigned mask)
+{
+       unsigned long flags;
+       struct gigaset_driver *drv = cs->driver;
+       spin_lock_irqsave(&drv->lock, flags);
+       drv->flags[cs->minor_index] |= mask;
+       spin_unlock_irqrestore(&drv->lock, flags);
+}
+
+static void make_invalid(struct cardstate *cs, unsigned mask)
+{
+       unsigned long flags;
+       struct gigaset_driver *drv = cs->driver;
+       spin_lock_irqsave(&drv->lock, flags);
+       drv->flags[cs->minor_index] &= ~mask;
+       spin_unlock_irqrestore(&drv->lock, flags);
+}
+
+void gigaset_freecs(struct cardstate *cs)
+{
+       int i;
+       unsigned long flags;
+
+       if (!cs)
+               return;
+
+       mutex_lock(&cs->mutex);
+
+       if (!cs->bcs)
+               goto f_cs;
+       if (!cs->inbuf)
+               goto f_bcs;
+
+       spin_lock_irqsave(&cs->lock, flags);
+       cs->running = 0;
+       spin_unlock_irqrestore(&cs->lock, flags); /* event handler and timer are
+                                                    not rescheduled below */
+
+       tasklet_kill(&cs->event_tasklet);
+       del_timer_sync(&cs->timer);
+
+       switch (cs->cs_init) {
+       default:
+               gigaset_if_free(cs);
+
+               gig_dbg(DEBUG_INIT, "clearing hw");
+               cs->ops->freecshw(cs);
+
+               //FIXME cmdbuf
+
+               /* fall through */
+       case 2: /* error in initcshw */
+               /* Deregister from LL */
+               make_invalid(cs, VALID_ID);
+               gig_dbg(DEBUG_INIT, "clearing iif");
+               gigaset_i4l_cmd(cs, ISDN_STAT_UNLOAD);
+
+               /* fall through */
+       case 1: /* error when regestering to LL */
+               gig_dbg(DEBUG_INIT, "clearing at_state");
+               clear_at_state(&cs->at_state);
+               dealloc_at_states(cs);
+
+               /* fall through */
+       case 0: /* error in one call to initbcs */
+               for (i = 0; i < cs->channels; ++i) {
+                       gig_dbg(DEBUG_INIT, "clearing bcs[%d]", i);
+                       gigaset_freebcs(cs->bcs + i);
+               }
+
+               clear_events(cs);
+               gig_dbg(DEBUG_INIT, "freeing inbuf");
+               kfree(cs->inbuf);
+       }
+f_bcs: gig_dbg(DEBUG_INIT, "freeing bcs[]");
+       kfree(cs->bcs);
+f_cs:  gig_dbg(DEBUG_INIT, "freeing cs");
+       mutex_unlock(&cs->mutex);
+       free_cs(cs);
+}
+EXPORT_SYMBOL_GPL(gigaset_freecs);
+
+void gigaset_at_init(struct at_state_t *at_state, struct bc_state *bcs,
+                    struct cardstate *cs, int cid)
+{
+       int i;
+
+       INIT_LIST_HEAD(&at_state->list);
+       at_state->waiting = 0;
+       at_state->getstring = 0;
+       at_state->pending_commands = 0;
+       at_state->timer_expires = 0;
+       at_state->timer_active = 0;
+       at_state->timer_index = 0;
+       at_state->seq_index = 0;
+       at_state->ConState = 0;
+       for (i = 0; i < STR_NUM; ++i)
+               at_state->str_var[i] = NULL;
+       at_state->int_var[VAR_ZDLE] = 0;
+       at_state->int_var[VAR_ZCTP] = -1;
+       at_state->int_var[VAR_ZSAU] = ZSAU_NULL;
+       at_state->cs = cs;
+       at_state->bcs = bcs;
+       at_state->cid = cid;
+       if (!cid)
+               at_state->replystruct = cs->tabnocid;
+       else
+               at_state->replystruct = cs->tabcid;
+}
+
+
+static void gigaset_inbuf_init(struct inbuf_t *inbuf, struct bc_state *bcs,
+                              struct cardstate *cs, int inputstate)
+/* inbuf->read must be allocated before! */
+{
+       atomic_set(&inbuf->head, 0);
+       atomic_set(&inbuf->tail, 0);
+       inbuf->cs = cs;
+       inbuf->bcs = bcs; /*base driver: NULL*/
+       inbuf->rcvbuf = NULL; //FIXME
+       inbuf->inputstate = inputstate;
+}
+
+/* append received bytes to inbuf */
+int gigaset_fill_inbuf(struct inbuf_t *inbuf, const unsigned char *src,
+                      unsigned numbytes)
+{
+       unsigned n, head, tail, bytesleft;
+
+       gig_dbg(DEBUG_INTR, "received %u bytes", numbytes);
+
+       if (!numbytes)
+               return 0;
+
+       bytesleft = numbytes;
+       tail = atomic_read(&inbuf->tail);
+       head = atomic_read(&inbuf->head);
+       gig_dbg(DEBUG_INTR, "buffer state: %u -> %u", head, tail);
+
+       while (bytesleft) {
+               if (head > tail)
+                       n = head - 1 - tail;
+               else if (head == 0)
+                       n = (RBUFSIZE-1) - tail;
+               else
+                       n = RBUFSIZE - tail;
+               if (!n) {
+                       dev_err(inbuf->cs->dev,
+                               "buffer overflow (%u bytes lost)", bytesleft);
+                       break;
+               }
+               if (n > bytesleft)
+                       n = bytesleft;
+               memcpy(inbuf->data + tail, src, n);
+               bytesleft -= n;
+               tail = (tail + n) % RBUFSIZE;
+               src += n;
+       }
+       gig_dbg(DEBUG_INTR, "setting tail to %u", tail);
+       atomic_set(&inbuf->tail, tail);
+       return numbytes != bytesleft;
+}
+EXPORT_SYMBOL_GPL(gigaset_fill_inbuf);
+
+/* Initialize the b-channel structure */
+static struct bc_state *gigaset_initbcs(struct bc_state *bcs,
+                                       struct cardstate *cs, int channel)
+{
+       int i;
+
+       bcs->tx_skb = NULL; //FIXME -> hw part
+
+       skb_queue_head_init(&bcs->squeue);
+
+       bcs->corrupted = 0;
+       bcs->trans_down = 0;
+       bcs->trans_up = 0;
+
+       gig_dbg(DEBUG_INIT, "setting up bcs[%d]->at_state", channel);
+       gigaset_at_init(&bcs->at_state, bcs, cs, -1);
+
+       bcs->rcvbytes = 0;
+
+#ifdef CONFIG_GIGASET_DEBUG
+       bcs->emptycount = 0;
+#endif
+
+       gig_dbg(DEBUG_INIT, "allocating bcs[%d]->skb", channel);
+       bcs->fcs = PPP_INITFCS;
+       bcs->inputstate = 0;
+       if (cs->ignoreframes) {
+               bcs->inputstate |= INS_skip_frame;
+               bcs->skb = NULL;
+       } else if ((bcs->skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN)) != NULL)
+               skb_reserve(bcs->skb, HW_HDR_LEN);
+       else {
+               dev_warn(cs->dev, "could not allocate skb\n");
+               bcs->inputstate |= INS_skip_frame;
+       }
+
+       bcs->channel = channel;
+       bcs->cs = cs;
+
+       bcs->chstate = 0;
+       bcs->use_count = 1;
+       bcs->busy = 0;
+       bcs->ignore = cs->ignoreframes;
+
+       for (i = 0; i < AT_NUM; ++i)
+               bcs->commands[i] = NULL;
+
+       gig_dbg(DEBUG_INIT, "  setting up bcs[%d]->hw", channel);
+       if (cs->ops->initbcshw(bcs))
+               return bcs;
+
+       gig_dbg(DEBUG_INIT, "  failed");
+
+       gig_dbg(DEBUG_INIT, "  freeing bcs[%d]->skb", channel);
+       if (bcs->skb)
+               dev_kfree_skb(bcs->skb);
+
+       return NULL;
+}
+
+/* gigaset_initcs
+ * Allocate and initialize cardstate structure for Gigaset driver
+ * Calls hardware dependent gigaset_initcshw() function
+ * Calls B channel initialization function gigaset_initbcs() for each B channel
+ * parameters:
+ *     drv             hardware driver the device belongs to
+ *     channels        number of B channels supported by device
+ *     onechannel      !=0: B channel data and AT commands share one
+ *                          communication channel
+ *                     ==0: B channels have separate communication channels
+ *     ignoreframes    number of frames to ignore after setting up B channel
+ *     cidmode         !=0: start in CallID mode
+ *     modulename      name of driver module (used for I4L registration)
+ * return value:
+ *     pointer to cardstate structure
+ */
+struct cardstate *gigaset_initcs(struct gigaset_driver *drv, int channels,
+                                int onechannel, int ignoreframes,
+                                int cidmode, const char *modulename)
+{
+       struct cardstate *cs = NULL;
+       unsigned long flags;
+       int i;
+
+       gig_dbg(DEBUG_INIT, "allocating cs");
+       cs = alloc_cs(drv);
+       if (!cs)
+               goto error;
+       gig_dbg(DEBUG_INIT, "allocating bcs[0..%d]", channels - 1);
+       cs->bcs = kmalloc(channels * sizeof(struct bc_state), GFP_KERNEL);
+       if (!cs->bcs)
+               goto error;
+       gig_dbg(DEBUG_INIT, "allocating inbuf");
+       cs->inbuf = kmalloc(sizeof(struct inbuf_t), GFP_KERNEL);
+       if (!cs->inbuf)
+               goto error;
+
+       cs->cs_init = 0;
+       cs->channels = channels;
+       cs->onechannel = onechannel;
+       cs->ignoreframes = ignoreframes;
+       INIT_LIST_HEAD(&cs->temp_at_states);
+       cs->running = 0;
+       init_timer(&cs->timer); /* clear next & prev */
+       spin_lock_init(&cs->ev_lock);
+       cs->ev_tail = 0;
+       cs->ev_head = 0;
+       mutex_init(&cs->mutex);
+       mutex_lock(&cs->mutex);
+
+       tasklet_init(&cs->event_tasklet, &gigaset_handle_event,
+                    (unsigned long) cs);
+       atomic_set(&cs->commands_pending, 0);
+       cs->cur_at_seq = 0;
+       cs->gotfwver = -1;
+       cs->open_count = 0;
+       cs->dev = NULL;
+       cs->tty = NULL;
+       cs->cidmode = cidmode != 0;
+
+       //if(onechannel) { //FIXME
+               cs->tabnocid = gigaset_tab_nocid_m10x;
+               cs->tabcid = gigaset_tab_cid_m10x;
+       //} else {
+       //      cs->tabnocid = gigaset_tab_nocid;
+       //      cs->tabcid = gigaset_tab_cid;
+       //}
+
+       init_waitqueue_head(&cs->waitqueue);
+       cs->waiting = 0;
+
+       atomic_set(&cs->mode, M_UNKNOWN);
+       atomic_set(&cs->mstate, MS_UNINITIALIZED);
+
+       for (i = 0; i < channels; ++i) {
+               gig_dbg(DEBUG_INIT, "setting up bcs[%d].read", i);
+               if (!gigaset_initbcs(cs->bcs + i, cs, i))
+                       goto error;
+       }
+
+       ++cs->cs_init;
+
+       gig_dbg(DEBUG_INIT, "setting up at_state");
+       spin_lock_init(&cs->lock);
+       gigaset_at_init(&cs->at_state, NULL, cs, 0);
+       cs->dle = 0;
+       cs->cbytes = 0;
+
+       gig_dbg(DEBUG_INIT, "setting up inbuf");
+       if (onechannel) {                       //FIXME distinction necessary?
+               gigaset_inbuf_init(cs->inbuf, cs->bcs, cs, INS_command);
+       } else
+               gigaset_inbuf_init(cs->inbuf, NULL,    cs, INS_command);
+
+       cs->connected = 0;
+       cs->isdn_up = 0;
+
+       gig_dbg(DEBUG_INIT, "setting up cmdbuf");
+       cs->cmdbuf = cs->lastcmdbuf = NULL;
+       spin_lock_init(&cs->cmdlock);
+       cs->curlen = 0;
+       cs->cmdbytes = 0;
+
+       gig_dbg(DEBUG_INIT, "setting up iif");
+       if (!gigaset_register_to_LL(cs, modulename)) {
+               err("register_isdn failed");
+               goto error;
+       }
+
+       make_valid(cs, VALID_ID);
+       ++cs->cs_init;
+       gig_dbg(DEBUG_INIT, "setting up hw");
+       if (!cs->ops->initcshw(cs))
+               goto error;
+
+       ++cs->cs_init;
+
+       gigaset_if_init(cs);
+
+       spin_lock_irqsave(&cs->lock, flags);
+       cs->running = 1;
+       spin_unlock_irqrestore(&cs->lock, flags);
+       setup_timer(&cs->timer, timer_tick, (unsigned long) cs);
+       cs->timer.expires = jiffies + msecs_to_jiffies(GIG_TICK);
+       /* FIXME: can jiffies increase too much until the timer is added?
+        * Same problem(?) with mod_timer() in timer_tick(). */
+       add_timer(&cs->timer);
+
+       gig_dbg(DEBUG_INIT, "cs initialized");
+       mutex_unlock(&cs->mutex);
+       return cs;
+
+error: if (cs)
+               mutex_unlock(&cs->mutex);
+       gig_dbg(DEBUG_INIT, "failed");
+       gigaset_freecs(cs);
+       return NULL;
+}
+EXPORT_SYMBOL_GPL(gigaset_initcs);
+
+/* ReInitialize the b-channel structure on hangup */
+void gigaset_bcs_reinit(struct bc_state *bcs)
+{
+       struct sk_buff *skb;
+       struct cardstate *cs = bcs->cs;
+       unsigned long flags;
+
+       while ((skb = skb_dequeue(&bcs->squeue)) != NULL)
+               dev_kfree_skb(skb);
+
+       spin_lock_irqsave(&cs->lock, flags);
+       clear_at_state(&bcs->at_state);
+       bcs->at_state.ConState = 0;
+       bcs->at_state.timer_active = 0;
+       bcs->at_state.timer_expires = 0;
+       bcs->at_state.cid = -1;                 /* No CID defined */
+       spin_unlock_irqrestore(&cs->lock, flags);
+
+       bcs->inputstate = 0;
+
+#ifdef CONFIG_GIGASET_DEBUG
+       bcs->emptycount = 0;
+#endif
+
+       bcs->fcs = PPP_INITFCS;
+       bcs->chstate = 0;
+
+       bcs->ignore = cs->ignoreframes;
+       if (bcs->ignore)
+               bcs->inputstate |= INS_skip_frame;
+
+
+       cs->ops->reinitbcshw(bcs);
+}
+
+static void cleanup_cs(struct cardstate *cs)
+{
+       struct cmdbuf_t *cb, *tcb;
+       int i;
+       unsigned long flags;
+
+       spin_lock_irqsave(&cs->lock, flags);
+
+       atomic_set(&cs->mode, M_UNKNOWN);
+       atomic_set(&cs->mstate, MS_UNINITIALIZED);
+
+       clear_at_state(&cs->at_state);
+       dealloc_at_states(cs);
+       free_strings(&cs->at_state);
+       gigaset_at_init(&cs->at_state, NULL, cs, 0);
+
+       kfree(cs->inbuf->rcvbuf);
+       cs->inbuf->rcvbuf = NULL;
+       cs->inbuf->inputstate = INS_command;
+       atomic_set(&cs->inbuf->head, 0);
+       atomic_set(&cs->inbuf->tail, 0);
+
+       cb = cs->cmdbuf;
+       while (cb) {
+               tcb = cb;
+               cb = cb->next;
+               kfree(tcb);
+       }
+       cs->cmdbuf = cs->lastcmdbuf = NULL;
+       cs->curlen = 0;
+       cs->cmdbytes = 0;
+       cs->gotfwver = -1;
+       cs->dle = 0;
+       cs->cur_at_seq = 0;
+       atomic_set(&cs->commands_pending, 0);
+       cs->cbytes = 0;
+
+       spin_unlock_irqrestore(&cs->lock, flags);
+
+       for (i = 0; i < cs->channels; ++i) {
+               gigaset_freebcs(cs->bcs + i);
+               if (!gigaset_initbcs(cs->bcs + i, cs, i))
+                       break;                  //FIXME error handling
+       }
+
+       if (cs->waiting) {
+               cs->cmd_result = -ENODEV;
+               cs->waiting = 0;
+               wake_up_interruptible(&cs->waitqueue);
+       }
+}
+
+
+int gigaset_start(struct cardstate *cs)
+{
+       unsigned long flags;
+
+       if (mutex_lock_interruptible(&cs->mutex))
+               return 0;
+
+       spin_lock_irqsave(&cs->lock, flags);
+       cs->connected = 1;
+       spin_unlock_irqrestore(&cs->lock, flags);
+
+       if (atomic_read(&cs->mstate) != MS_LOCKED) {
+               cs->ops->set_modem_ctrl(cs, 0, TIOCM_DTR|TIOCM_RTS);
+               cs->ops->baud_rate(cs, B115200);
+               cs->ops->set_line_ctrl(cs, CS8);
+               cs->control_state = TIOCM_DTR|TIOCM_RTS;
+       } else {
+               //FIXME use some saved values?
+       }
+
+       cs->waiting = 1;
+
+       if (!gigaset_add_event(cs, &cs->at_state, EV_START, NULL, 0, NULL)) {
+               cs->waiting = 0;
+               //FIXME what should we do?
+               goto error;
+       }
+
+       gig_dbg(DEBUG_CMD, "scheduling START");
+       gigaset_schedule_event(cs);
+
+       wait_event(cs->waitqueue, !cs->waiting);
+
+       /* set up device sysfs */
+       gigaset_init_dev_sysfs(cs);
+
+       mutex_unlock(&cs->mutex);
+       return 1;
+
+error:
+       mutex_unlock(&cs->mutex);
+       return 0;
+}
+EXPORT_SYMBOL_GPL(gigaset_start);
+
+void gigaset_shutdown(struct cardstate *cs)
+{
+       mutex_lock(&cs->mutex);
+
+       cs->waiting = 1;
+
+       if (!gigaset_add_event(cs, &cs->at_state, EV_SHUTDOWN, NULL, 0, NULL)) {
+               //FIXME what should we do?
+               goto exit;
+       }
+
+       gig_dbg(DEBUG_CMD, "scheduling SHUTDOWN");
+       gigaset_schedule_event(cs);
+
+       if (wait_event_interruptible(cs->waitqueue, !cs->waiting)) {
+               warn("%s: aborted", __func__);
+               //FIXME
+       }
+
+       if (atomic_read(&cs->mstate) != MS_LOCKED) {
+               //FIXME?
+               //gigaset_baud_rate(cs, B115200);
+               //gigaset_set_line_ctrl(cs, CS8);
+               //gigaset_set_modem_ctrl(cs, TIOCM_DTR|TIOCM_RTS, 0);
+               //cs->control_state = 0;
+       } else {
+               //FIXME use some saved values?
+       }
+
+       cleanup_cs(cs);
+
+exit:
+       mutex_unlock(&cs->mutex);
+}
+EXPORT_SYMBOL_GPL(gigaset_shutdown);
+
+void gigaset_stop(struct cardstate *cs)
+{
+       mutex_lock(&cs->mutex);
+
+       cs->waiting = 1;
+
+       if (!gigaset_add_event(cs, &cs->at_state, EV_STOP, NULL, 0, NULL)) {
+               //FIXME what should we do?
+               goto exit;
+       }
+
+       gig_dbg(DEBUG_CMD, "scheduling STOP");
+       gigaset_schedule_event(cs);
+
+       if (wait_event_interruptible(cs->waitqueue, !cs->waiting)) {
+               warn("%s: aborted", __func__);
+               //FIXME
+       }
+
+       /* clear device sysfs */
+       gigaset_free_dev_sysfs(cs);
+
+       cleanup_cs(cs);
+
+exit:
+       mutex_unlock(&cs->mutex);
+}
+EXPORT_SYMBOL_GPL(gigaset_stop);
+
+static LIST_HEAD(drivers);
+static spinlock_t driver_lock = SPIN_LOCK_UNLOCKED;
+
+struct cardstate *gigaset_get_cs_by_id(int id)
+{
+       unsigned long flags;
+       static struct cardstate *ret = NULL;
+       static struct cardstate *cs;
+       struct gigaset_driver *drv;
+       unsigned i;
+
+       spin_lock_irqsave(&driver_lock, flags);
+       list_for_each_entry(drv, &drivers, list) {
+               spin_lock(&drv->lock);
+               for (i = 0; i < drv->minors; ++i) {
+                       if (drv->flags[i] & VALID_ID) {
+                               cs = drv->cs + i;
+                               if (cs->myid == id)
+                                       ret = cs;
+                       }
+                       if (ret)
+                               break;
+               }
+               spin_unlock(&drv->lock);
+               if (ret)
+                       break;
+       }
+       spin_unlock_irqrestore(&driver_lock, flags);
+       return ret;
+}
+
+void gigaset_debugdrivers(void)
+{
+       unsigned long flags;
+       static struct cardstate *cs;
+       struct gigaset_driver *drv;
+       unsigned i;
+
+       spin_lock_irqsave(&driver_lock, flags);
+       list_for_each_entry(drv, &drivers, list) {
+               gig_dbg(DEBUG_DRIVER, "driver %p", drv);
+               spin_lock(&drv->lock);
+               for (i = 0; i < drv->minors; ++i) {
+                       gig_dbg(DEBUG_DRIVER, "  index %u", i);
+                       gig_dbg(DEBUG_DRIVER, "    flags 0x%02x",
+                               drv->flags[i]);
+                       cs = drv->cs + i;
+                       gig_dbg(DEBUG_DRIVER, "    cardstate %p", cs);
+                       gig_dbg(DEBUG_DRIVER, "    minor_index %u",
+                               cs->minor_index);
+                       gig_dbg(DEBUG_DRIVER, "    driver %p", cs->driver);
+                       gig_dbg(DEBUG_DRIVER, "    i4l id %d", cs->myid);
+               }
+               spin_unlock(&drv->lock);
+       }
+       spin_unlock_irqrestore(&driver_lock, flags);
+}
+
+static struct cardstate *gigaset_get_cs_by_minor(unsigned minor)
+{
+       unsigned long flags;
+       static struct cardstate *ret = NULL;
+       struct gigaset_driver *drv;
+       unsigned index;
+
+       spin_lock_irqsave(&driver_lock, flags);
+       list_for_each_entry(drv, &drivers, list) {
+               if (minor < drv->minor || minor >= drv->minor + drv->minors)
+                       continue;
+               index = minor - drv->minor;
+               spin_lock(&drv->lock);
+               if (drv->flags[index] & VALID_MINOR)
+                       ret = drv->cs + index;
+               spin_unlock(&drv->lock);
+               if (ret)
+                       break;
+       }
+       spin_unlock_irqrestore(&driver_lock, flags);
+       return ret;
+}
+
+struct cardstate *gigaset_get_cs_by_tty(struct tty_struct *tty)
+{
+       if (tty->index < 0 || tty->index >= tty->driver->num)
+               return NULL;
+       return gigaset_get_cs_by_minor(tty->index + tty->driver->minor_start);
+}
+
+void gigaset_freedriver(struct gigaset_driver *drv)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&driver_lock, flags);
+       list_del(&drv->list);
+       spin_unlock_irqrestore(&driver_lock, flags);
+
+       gigaset_if_freedriver(drv);
+       module_put(drv->owner);
+
+       kfree(drv->cs);
+       kfree(drv->flags);
+       kfree(drv);
+}
+EXPORT_SYMBOL_GPL(gigaset_freedriver);
+
+/* gigaset_initdriver
+ * Allocate and initialize gigaset_driver structure. Initialize interface.
+ * parameters:
+ *     minor           First minor number
+ *     minors          Number of minors this driver can handle
+ *     procname        Name of the driver
+ *     devname         Name of the device files (prefix without minor number)
+ *     devfsname       Devfs name of the device files without %d
+ * return value:
+ *     Pointer to the gigaset_driver structure on success, NULL on failure.
+ */
+struct gigaset_driver *gigaset_initdriver(unsigned minor, unsigned minors,
+                                         const char *procname,
+                                         const char *devname,
+                                         const char *devfsname,
+                                         const struct gigaset_ops *ops,
+                                         struct module *owner)
+{
+       struct gigaset_driver *drv;
+       unsigned long flags;
+       unsigned i;
+
+       drv = kmalloc(sizeof *drv, GFP_KERNEL);
+       if (!drv)
+               return NULL;
+
+       if (!try_module_get(owner))
+               goto out1;
+
+       drv->cs = NULL;
+       drv->have_tty = 0;
+       drv->minor = minor;
+       drv->minors = minors;
+       spin_lock_init(&drv->lock);
+       drv->blocked = 0;
+       drv->ops = ops;
+       drv->owner = owner;
+       INIT_LIST_HEAD(&drv->list);
+
+       drv->cs = kmalloc(minors * sizeof *drv->cs, GFP_KERNEL);
+       if (!drv->cs)
+               goto out2;
+
+       drv->flags = kmalloc(minors * sizeof *drv->flags, GFP_KERNEL);
+       if (!drv->flags)
+               goto out3;
+
+       for (i = 0; i < minors; ++i) {
+               drv->flags[i] = 0;
+               drv->cs[i].driver = drv;
+               drv->cs[i].ops = drv->ops;
+               drv->cs[i].minor_index = i;
+       }
+
+       gigaset_if_initdriver(drv, procname, devname, devfsname);
+
+       spin_lock_irqsave(&driver_lock, flags);
+       list_add(&drv->list, &drivers);
+       spin_unlock_irqrestore(&driver_lock, flags);
+
+       return drv;
+
+out3:
+       kfree(drv->cs);
+out2:
+       module_put(owner);
+out1:
+       kfree(drv);
+       return NULL;
+}
+EXPORT_SYMBOL_GPL(gigaset_initdriver);
+
+/* For drivers without fixed assignment device<->cardstate (usb) */
+struct cardstate *gigaset_getunassignedcs(struct gigaset_driver *drv)
+{
+       unsigned long flags;
+       struct cardstate *cs = NULL;
+       unsigned i;
+
+       spin_lock_irqsave(&drv->lock, flags);
+       if (drv->blocked)
+               goto exit;
+       for (i = 0; i < drv->minors; ++i) {
+               if ((drv->flags[i] & VALID_MINOR) &&
+                   !(drv->flags[i] & ASSIGNED)) {
+                       drv->flags[i] |= ASSIGNED;
+                       cs = drv->cs + i;
+                       break;
+               }
+       }
+exit:
+       spin_unlock_irqrestore(&drv->lock, flags);
+       return cs;
+}
+EXPORT_SYMBOL_GPL(gigaset_getunassignedcs);
+
+void gigaset_unassign(struct cardstate *cs)
+{
+       unsigned long flags;
+       unsigned *minor_flags;
+       struct gigaset_driver *drv;
+
+       if (!cs)
+               return;
+       drv = cs->driver;
+       spin_lock_irqsave(&drv->lock, flags);
+       minor_flags = drv->flags + cs->minor_index;
+       if (*minor_flags & VALID_MINOR)
+               *minor_flags &= ~ASSIGNED;
+       spin_unlock_irqrestore(&drv->lock, flags);
+}
+EXPORT_SYMBOL_GPL(gigaset_unassign);
+
+void gigaset_blockdriver(struct gigaset_driver *drv)
+{
+       unsigned long flags;
+       spin_lock_irqsave(&drv->lock, flags);
+       drv->blocked = 1;
+       spin_unlock_irqrestore(&drv->lock, flags);
+}
+EXPORT_SYMBOL_GPL(gigaset_blockdriver);
+
+static int __init gigaset_init_module(void)
+{
+       /* in accordance with the principle of least astonishment,
+        * setting the 'debug' parameter to 1 activates a sensible
+        * set of default debug levels
+        */
+       if (gigaset_debuglevel == 1)
+               gigaset_debuglevel = DEBUG_DEFAULT;
+
+       info(DRIVER_AUTHOR);
+       info(DRIVER_DESC);
+       return 0;
+}
+
+static void __exit gigaset_exit_module(void)
+{
+}
+
+module_init(gigaset_init_module);
+module_exit(gigaset_exit_module);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+
+MODULE_LICENSE("GPL");