path: root/drivers/net/irda/sir_dev.c

/*********************************************************************
 *
 *	sir_dev.c:	irda sir network device
 * 
 *	Copyright (c) 2002 Martin Diehl
 * 
 *	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 <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>

#include <net/irda/irda.h>
#include <net/irda/wrapper.h>
#include <net/irda/irda_device.h>

#include "sir-dev.h"


static struct workqueue_struct *irda_sir_wq;

/* STATE MACHINE */

/* substate handler of the config-fsm to handle the cases where we want
 * to wait for transmit completion before changing the port configuration
 */

static int sirdev_tx_complete_fsm(struct sir_dev *dev)
{
	struct sir_fsm *fsm = &dev->fsm;
	unsigned next_state, delay;
	unsigned bytes_left;

	do {
		next_state = fsm->substate;	/* default: stay in current substate */
		delay = 0;

		switch(fsm->substate) {

		case SIRDEV_STATE_WAIT_XMIT:
			if (dev->drv->chars_in_buffer)
				bytes_left = dev->drv->chars_in_buffer(dev);
			else
				bytes_left = 0;
			if (!bytes_left) {
				next_state = SIRDEV_STATE_WAIT_UNTIL_SENT;
				break;
			}

			if (dev->speed > 115200)
				delay = (bytes_left*8*10000) / (dev->speed/100);
			else if (dev->speed > 0)
				delay = (bytes_left*10*10000) / (dev->speed/100);
			else
				delay = 0;
			/* expected delay (usec) until remaining bytes are sent */
			if (delay < 100) {
				udelay(delay);
				delay = 0;
				break;
			}
			/* sleep some longer delay (msec) */
			delay = (delay+999) / 1000;
			break;

		case SIRDEV_STATE_WAIT_UNTIL_SENT:
			/* block until underlaying hardware buffer are empty */
			if (dev->drv->wait_until_sent)
				dev->drv->wait_until_sent(dev);
			next_state = SIRDEV_STATE_TX_DONE;
			break;

		case SIRDEV_STATE_TX_DONE:
			return 0;

		default:
			IRDA_ERROR("%s - undefined state\n", __func__);
			return -EINVAL;
		}
		fsm->substate = next_state;
	} while (delay == 0);
	return delay;
}

/*
 * Function sirdev_config_fsm
 *
 * State machine to handle the configuration of the device (and attached dongle, if any).
 * This handler is scheduled for execution in kIrDAd context, so we can sleep.
 * however, kIrDAd is shared by all sir_dev devices so we better don't sleep there too
 * long. Instead, for longer delays we start a timer to reschedule us later.
 * On entry, fsm->sem is always locked and the netdev xmit queue stopped.
 * Both must be unlocked/restarted on completion - but only on final exit.
 */

static void sirdev_config_fsm(struct work_struct *work)
{
	struct sir_dev *dev = container_of(work, struct sir_dev, fsm.work.work);
	struct sir_fsm *fsm = &dev->fsm;
	int next_state;
	int ret = -1;
	unsigned delay;

	IRDA_DEBUG(2, "%s(), <%ld>\n", __func__, jiffies);

	do {
		IRDA_DEBUG(3, "%s - state=0x%04x / substate=0x%04x\n",
			__func__, fsm->state, fsm->substate);

		next_state = fsm->state;
		delay = 0;

		switch(fsm->state) {

		case SIRDEV_STATE_DONGLE_OPEN:
			if (dev->dongle_drv != NULL) {
				ret = sirdev_put_dongle(dev);
				if (ret) {
					fsm->result = -EINVAL;
					next_state = SIRDEV_STATE_ERROR;
					break;
				}
			}

			/* Initialize dongle */
			ret = sirdev_get_dongle(dev, fsm->param);
			if (ret) {
				fsm->result = ret;
				next_state = SIRDEV_STATE_ERROR;
				break;
			}

			/* Dongles are powered through the modem control lines which
			 * were just set during open. Before resetting, let's wait for
			 * the power to stabilize. This is what some dongle drivers did
			 * in open before, while others didn't - should be safe anyway.
			 */

			delay = 50;
			fsm->substate = SIRDEV_STATE_DONGLE_RESET;
			next_state = SIRDEV_STATE_DONGLE_RESET;

			fsm->param = 9600;

			break;

		case SIRDEV_STATE_DONGLE_CLOSE:
			/* shouldn't we just treat this as success=? */
			if (dev->dongle_drv == NULL) {
				fsm->result = -EINVAL;
				next_state = SIRDEV_STATE_ERROR;
				break;
			}

			ret = sirdev_put_dongle(dev);
			if (ret) {
				fsm->result = ret;
				next_state = SIRDEV_STATE_ERROR;
				break;
			}
			next_state = SIRDEV_STATE_DONE;
			break;

		case SIRDEV_STATE_SET_DTR_RTS:
			ret = sirdev_set_dtr_rts(dev,
				(fsm->param&0x02) ? TRUE