synclink_cs.c

linux-2.6.15.6

/*
 * 1st function defined in .text section. Calling this function in
 * init_module() followed by a breakpoint allows a remote debugger
 * (gdb) to get the .text address for the add-symbol-file command.
 * This allows remote debugging of dynamically loadable modules.
 */
static void* mgslpc_get_text_ptr(void)
{
	return mgslpc_get_text_ptr;
}

/**
 * line discipline callback wrappers
 *
 * The wrappers maintain line discipline references
 * while calling into the line discipline.
 *
 * ldisc_flush_buffer - flush line discipline receive buffers
 * ldisc_receive_buf  - pass receive data to line discipline
 */

static void ldisc_flush_buffer(struct tty_struct *tty)
{
	struct tty_ldisc *ld = tty_ldisc_ref(tty);
	if (ld) {
		if (ld->flush_buffer)
			ld->flush_buffer(tty);
		tty_ldisc_deref(ld);
	}
}

static void ldisc_receive_buf(struct tty_struct *tty,
			      const __u8 *data, char *flags, int count)
{
	struct tty_ldisc *ld;
	if (!tty)
		return;
	ld = tty_ldisc_ref(tty);
	if (ld) {
		if (ld->receive_buf)
			ld->receive_buf(tty, data, flags, count);
		tty_ldisc_deref(ld);
	}
}

static dev_link_t *mgslpc_attach(void)
{
    MGSLPC_INFO *info;
    dev_link_t *link;
    client_reg_t client_reg;
    int ret;
    
    if (debug_level >= DEBUG_LEVEL_INFO)
	    printk("mgslpc_attach\n");
	
    info = (MGSLPC_INFO *)kmalloc(sizeof(MGSLPC_INFO), GFP_KERNEL);
    if (!info) {
	    printk("Error can't allocate device instance data\n");
	    return NULL;
    }

    memset(info, 0, sizeof(MGSLPC_INFO));
    info->magic = MGSLPC_MAGIC;
    INIT_WORK(&info->task, bh_handler, info);
    info->max_frame_size = 4096;
    info->close_delay = 5*HZ/10;
    info->closing_wait = 30*HZ;
    init_waitqueue_head(&info->open_wait);
    init_waitqueue_head(&info->close_wait);
    init_waitqueue_head(&info->status_event_wait_q);
    init_waitqueue_head(&info->event_wait_q);
    spin_lock_init(&info->lock);
    spin_lock_init(&info->netlock);
    memcpy(&info->params,&default_params,sizeof(MGSL_PARAMS));
    info->idle_mode = HDLC_TXIDLE_FLAGS;		
    info->imra_value = 0xffff;
    info->imrb_value = 0xffff;
    info->pim_value = 0xff;

    link = &info->link;
    link->priv = info;
    
    /* Initialize the dev_link_t structure */

    /* Interrupt setup */
    link->irq.Attributes = IRQ_TYPE_EXCLUSIVE;
    link->irq.IRQInfo1   = IRQ_LEVEL_ID;
    link->irq.Handler = NULL;
    
    link->conf.Attributes = 0;
    link->conf.Vcc = 50;
    link->conf.IntType = INT_MEMORY_AND_IO;

    /* Register with Card Services */
    link->next = dev_list;
    dev_list = link;

    client_reg.dev_info = &dev_info;
    client_reg.Version = 0x0210;
    client_reg.event_callback_args.client_data = link;

    ret = pcmcia_register_client(&link->handle, &client_reg);
    if (ret != CS_SUCCESS) {
	    cs_error(link->handle, RegisterClient, ret);
	    mgslpc_detach(link);
	    return NULL;
    }

    mgslpc_add_device(info);

    return link;
}

/* Card has been inserted.
 */

#define CS_CHECK(fn, ret) \
do { last_fn = (fn); if ((last_ret = (ret)) != 0) goto cs_failed; } while (0)

static void mgslpc_config(dev_link_t *link)
{
    client_handle_t handle = link->handle;
    MGSLPC_INFO *info = link->priv;
    tuple_t tuple;
    cisparse_t parse;
    int last_fn, last_ret;
    u_char buf[64];
    config_info_t conf;
    cistpl_cftable_entry_t dflt = { 0 };
    cistpl_cftable_entry_t *cfg;
    
    if (debug_level >= DEBUG_LEVEL_INFO)
	    printk("mgslpc_config(0x%p)\n", link);

    /* read CONFIG tuple to find its configuration registers */
    tuple.DesiredTuple = CISTPL_CONFIG;
    tuple.Attributes = 0;
    tuple.TupleData = buf;
    tuple.TupleDataMax = sizeof(buf);
    tuple.TupleOffset = 0;
    CS_CHECK(GetFirstTuple, pcmcia_get_first_tuple(handle, &tuple));
    CS_CHECK(GetTupleData, pcmcia_get_tuple_data(handle, &tuple));
    CS_CHECK(ParseTuple, pcmcia_parse_tuple(handle, &tuple, &parse));
    link->conf.ConfigBase = parse.config.base;
    link->conf.Present = parse.config.rmask[0];
    
    /* Configure card */
    link->state |= DEV_CONFIG;

    /* Look up the current Vcc */
    CS_CHECK(GetConfigurationInfo, pcmcia_get_configuration_info(handle, &conf));
    link->conf.Vcc = conf.Vcc;

    /* get CIS configuration entry */

    tuple.DesiredTuple = CISTPL_CFTABLE_ENTRY;
    CS_CHECK(GetFirstTuple, pcmcia_get_first_tuple(handle, &tuple));

    cfg = &(parse.cftable_entry);
    CS_CHECK(GetTupleData, pcmcia_get_tuple_data(handle, &tuple));
    CS_CHECK(ParseTuple, pcmcia_parse_tuple(handle, &tuple, &parse));

    if (cfg->flags & CISTPL_CFTABLE_DEFAULT) dflt = *cfg;
    if (cfg->index == 0)
	    goto cs_failed;

    link->conf.ConfigIndex = cfg->index;
    link->conf.Attributes |= CONF_ENABLE_IRQ;
	
    /* IO window settings */
    link->io.NumPorts1 = 0;
    if ((cfg->io.nwin > 0) || (dflt.io.nwin > 0)) {
	    cistpl_io_t *io = (cfg->io.nwin) ? &cfg->io : &dflt.io;
	    link->io.Attributes1 = IO_DATA_PATH_WIDTH_AUTO;
	    if (!(io->flags & CISTPL_IO_8BIT))
		    link->io.Attributes1 = IO_DATA_PATH_WIDTH_16;
	    if (!(io->flags & CISTPL_IO_16BIT))
		    link->io.Attributes1 = IO_DATA_PATH_WIDTH_8;
	    link->io.IOAddrLines = io->flags & CISTPL_IO_LINES_MASK;
	    link->io.BasePort1 = io->win[0].base;
	    link->io.NumPorts1 = io->win[0].len;
	    CS_CHECK(RequestIO, pcmcia_request_io(link->handle, &link->io));
    }

    link->conf.Attributes = CONF_ENABLE_IRQ;
    link->conf.Vcc = 50;
    link->conf.IntType = INT_MEMORY_AND_IO;
    link->conf.ConfigIndex = 8;
    link->conf.Present = PRESENT_OPTION;
    
    link->irq.Attributes |= IRQ_HANDLE_PRESENT;
    link->irq.Handler     = mgslpc_isr;
    link->irq.Instance    = info;
    CS_CHECK(RequestIRQ, pcmcia_request_irq(link->handle, &link->irq));

    CS_CHECK(RequestConfiguration, pcmcia_request_configuration(link->handle, &link->conf));

    info->io_base = link->io.BasePort1;
    info->irq_level = link->irq.AssignedIRQ;

    /* add to linked list of devices */
    sprintf(info->node.dev_name, "mgslpc0");
    info->node.major = info->node.minor = 0;
    link->dev = &info->node;

    printk(KERN_INFO "%s: index 0x%02x:",
	   info->node.dev_name, link->conf.ConfigIndex);
    if (link->conf.Attributes & CONF_ENABLE_IRQ)
	    printk(", irq %d", link->irq.AssignedIRQ);
    if (link->io.NumPorts1)
	    printk(", io 0x%04x-0x%04x", link->io.BasePort1,
		   link->io.BasePort1+link->io.NumPorts1-1);
    printk("\n");
    
    link->state &= ~DEV_CONFIG_PENDING;
    return;

cs_failed:
    cs_error(link->handle, last_fn, last_ret);
    mgslpc_release((u_long)link);
}

/* Card has been removed.
 * Unregister device and release PCMCIA configuration.
 * If device is open, postpone until it is closed.
 */
static void mgslpc_release(u_long arg)
{
    dev_link_t *link = (dev_link_t *)arg;

    if (debug_level >= DEBUG_LEVEL_INFO)
	    printk("mgslpc_release(0x%p)\n", link);

    /* Unlink the device chain */
    link->dev = NULL;
    link->state &= ~DEV_CONFIG;

    pcmcia_release_configuration(link->handle);
    if (link->io.NumPorts1)
	    pcmcia_release_io(link->handle, &link->io);
    if (link->irq.AssignedIRQ)
	    pcmcia_release_irq(link->handle, &link->irq);
    if (link->state & DEV_STALE_LINK)
	    mgslpc_detach(link);
}

static void mgslpc_detach(dev_link_t *link)
{
    dev_link_t **linkp;

    if (debug_level >= DEBUG_LEVEL_INFO)
	    printk("mgslpc_detach(0x%p)\n", link);
    
    /* find device */
    for (linkp = &dev_list; *linkp; linkp = &(*linkp)->next)
	    if (*linkp == link) break;
    if (*linkp == NULL)
	    return;

    if (link->state & DEV_CONFIG) {
	    /* device is configured/active, mark it so when
	     * release() is called a proper detach() occurs.
	     */
	    if (debug_level >= DEBUG_LEVEL_INFO)
		    printk(KERN_DEBUG "synclinkpc: detach postponed, '%s' "
			   "still locked\n", link->dev->dev_name);
	    link->state |= DEV_STALE_LINK;
	    return;
    }

    /* Break the link with Card Services */
    if (link->handle)
	    pcmcia_deregister_client(link->handle);
    
    /* Unlink device structure, and free it */
    *linkp = link->next;
    mgslpc_remove_device((MGSLPC_INFO *)link->priv);
}

static int mgslpc_event(event_t event, int priority,
			event_callback_args_t *args)
{
    dev_link_t *link = args->client_data;
    MGSLPC_INFO *info = link->priv;
    
    if (debug_level >= DEBUG_LEVEL_INFO)
	    printk("mgslpc_event(0x%06x)\n", event);
    
    switch (event) {
    case CS_EVENT_CARD_REMOVAL:
	    link->state &= ~DEV_PRESENT;
	    if (link->state & DEV_CONFIG) {
		    ((MGSLPC_INFO *)link->priv)->stop = 1;
		    mgslpc_release((u_long)link);
	    }
	    break;
    case CS_EVENT_CARD_INSERTION:
	    link->state |= DEV_PRESENT | DEV_CONFIG_PENDING;
	    mgslpc_config(link);
	    break;
    case CS_EVENT_PM_SUSPEND:
	    link->state |= DEV_SUSPEND;
	    /* Fall through... */
    case CS_EVENT_RESET_PHYSICAL:
	    /* Mark the device as stopped, to block IO until later */
	    info->stop = 1;
	    if (link->state & DEV_CONFIG)
		    pcmcia_release_configuration(link->handle);
	    break;
    case CS_EVENT_PM_RESUME:
	    link->state &= ~DEV_SUSPEND;
	    /* Fall through... */
    case CS_EVENT_CARD_RESET:
	    if (link->state & DEV_CONFIG)
		    pcmcia_request_configuration(link->handle, &link->conf);
	    info->stop = 0;
	    break;
    }
    return 0;
}

static inline int mgslpc_paranoia_check(MGSLPC_INFO *info,
					char *name, const char *routine)
{
#ifdef MGSLPC_PARANOIA_CHECK
	static const char *badmagic =
		"Warning: bad magic number for mgsl struct (%s) in %s\n";
	static const char *badinfo =
		"Warning: null mgslpc_info for (%s) in %s\n";

	if (!info) {
		printk(badinfo, name, routine);
		return 1;
	}
	if (info->magic != MGSLPC_MAGIC) {
		printk(badmagic, name, routine);
		return 1;
	}
#else
	if (!info)
		return 1;
#endif
	return 0;
}


#define CMD_RXFIFO      BIT7	// release current rx FIFO
#define CMD_RXRESET     BIT6	// receiver reset
#define CMD_RXFIFO_READ BIT5
#define CMD_START_TIMER BIT4
#define CMD_TXFIFO      BIT3	// release current tx FIFO
#define CMD_TXEOM       BIT1	// transmit end message
#define CMD_TXRESET     BIT0	// transmit reset

static BOOLEAN wait_command_complete(MGSLPC_INFO *info, unsigned char channel) 
{
	int i = 0;
	/* wait for command completion */ 
	while (read_reg(info, (unsigned char)(channel+STAR)) & BIT2) {
		udelay(1);
		if (i++ == 1000)
			return FALSE;
	}
	return TRUE;
}

static void issue_command(MGSLPC_INFO *info, unsigned char channel, unsigned char cmd) 
{
	wait_command_complete(info, channel);
	write_reg(info, (unsigned char) (channel + CMDR), cmd);
}

static void tx_pause(struct tty_struct *tty)
{
	MGSLPC_INFO *info = (MGSLPC_INFO *)tty->driver_data;
	unsigned long flags;
	
	if (mgslpc_paranoia_check(info, tty->name, "tx_pause"))
		return;
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("tx_pause(%s)\n",info->device_name);	
		
	spin_lock_irqsave(&info->lock,flags);
	if (info->tx_enabled)
	 	tx_stop(info);
	spin_unlock_irqrestore(&info->lock,flags);
}

static void tx_release(struct tty_struct *tty)
{
	MGSLPC_INFO *info = (MGSLPC_INFO *)tty->driver_data;
	unsigned long flags;
	
	if (mgslpc_paranoia_check(info, tty->name, "tx_release"))
		return;
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("tx_release(%s)\n",info->device_name);	
		
	spin_lock_irqsave(&info->lock,flags);
	if (!info->tx_enabled)
	 	tx_start(info);
	spin_unlock_irqrestore(&info->lock,flags);
}

/* Return next bottom half action to perform.
 * or 0 if nothing to do.
 */
static int bh_action(MGSLPC_INFO *info)
{
	unsigned long flags;
	int rc = 0;
	
	spin_lock_irqsave(&info->lock,flags);

	if (info->pending_bh & BH_RECEIVE) {
		info->pending_bh &= ~BH_RECEIVE;
		rc = BH_RECEIVE;
	} else if (info->pending_bh & BH_TRANSMIT) {
		info->pending_bh &= ~BH_TRANSMIT;
		rc = BH_TRANSMIT;
	} else if (info->pending_bh & BH_STATUS) {
		info->pending_bh &= ~BH_STATUS;
		rc = BH_STATUS;
	}

	if (!rc) {
		/* Mark BH routine as complete */
		info->bh_running   = 0;
		info->bh_requested = 0;
	}
	
	spin_unlock_irqrestore(&info->lock,flags);
	
	return rc;
}

void bh_handler(void* Context)
{
	MGSLPC_INFO *info = (MGSLPC_INFO*)Context;
	int action;

	if (!info)
		return;
		
	if (debug_level >= DEBUG_LEVEL_BH)
		printk( "%s(%d):bh_handler(%s) entry\n",
			__FILE__,__LINE__,info->device_name);
	
	info->bh_running = 1;

	while((action = bh_action(info)) != 0) {
	
		/* Process work item */
		if ( debug_level >= DEBUG_LEVEL_BH )
			printk( "%s(%d):bh_handler() work item action=%d\n",
				__FILE__,__LINE__,action);

		switch (action) {
		
		case BH_RECEIVE:
			while(rx_get_frame(info));
			break;
		case BH_TRANSMIT:
			bh_transmit(info);
			break;
		case BH_STATUS:
			bh_status(info);
			break;
		default:
			/* unknown work item ID */
			printk("Unknown work item ID=%08X!\n", action);
			break;
		}
	}

	if (debug_level >= DEBUG_LEVEL_BH)
		printk( "%s(%d):bh_handler(%s) exit\n",
			__FILE__,__LINE__,info->device_name);
}

void bh_transmit(MGSLPC_INFO *info)
{
	struct tty_struct *tty = info->tty;
	if (debug_level >= DEBUG_LEVEL_BH)
		printk("bh_transmit() entry on %s\n", info->device_name);

	if (tty) {
		tty_wakeup(tty);
		wake_up_interruptible(&tty->write_wait);
	}
}

void bh_status(MGSLPC_INFO *info)
{