common.c

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/*
 * Stuff used by all variants of the driver
 *
 * Copyright (c) 2001 by Stefan Eilers,
 *                       Hansjoerg Lipp <[e-mail]>,
 *                       Tilman Schmidt <[e-mail]>.
 *
 * =====================================================================
 *	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 <[e-mail]>, Tilman Schmidt <[e-mail]>, 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

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;
	struct cardstate *ret = NULL;

	spin_lock_irqsave(&drv->lock, flags);
	for (i = 0; i < drv->minors; ++i) {
		if (!(drv->flags[i] & VALID_MINOR)) {
			if (try_module_get(drv->owner)) {
				drv->flags[i] = VALID_MINOR;
				ret = drv->cs + i;
			}
			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);
	if (drv->flags[cs->minor_index] & VALID_MINOR)
		module_put(drv->owner);
	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:
		/* clear device sysfs */
		gigaset_free_dev_sysfs(cs);

		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)\n",
				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 {
		warn("could not allocate skb");
		bcs->inputstate |= INS_skip_frame;
	}

	bcs->channel = channel;
	bcs->cs = cs;