diff options
Diffstat (limited to 'drivers/net/irda/sir_dev.c')
-rw-r--r-- | drivers/net/irda/sir_dev.c | 315 |
1 files changed, 311 insertions, 4 deletions
diff --git a/drivers/net/irda/sir_dev.c b/drivers/net/irda/sir_dev.c index ea7c9464d46..3b5854d10c1 100644 --- a/drivers/net/irda/sir_dev.c +++ b/drivers/net/irda/sir_dev.c @@ -23,6 +23,298 @@ #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", __FUNCTION__); + 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(void *data) +{ + struct sir_dev *dev = data; + struct sir_fsm *fsm = &dev->fsm; + int next_state; + int ret = -1; + unsigned delay; + + IRDA_DEBUG(2, "%s(), <%ld>\n", __FUNCTION__, jiffies); + + do { + IRDA_DEBUG(3, "%s - state=0x%04x / substate=0x%04x\n", + __FUNCTION__, 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 : FALSE, + (fsm->param&0x01) ? TRUE : FALSE); + next_state = SIRDEV_STATE_DONE; + break; + + case SIRDEV_STATE_SET_SPEED: + fsm->substate = SIRDEV_STATE_WAIT_XMIT; + next_state = SIRDEV_STATE_DONGLE_CHECK; + break; + + case SIRDEV_STATE_DONGLE_CHECK: + ret = sirdev_tx_complete_fsm(dev); + if (ret < 0) { + fsm->result = ret; + next_state = SIRDEV_STATE_ERROR; + break; + } + if ((delay=ret) != 0) + break; + + if (dev->dongle_drv) { + fsm->substate = SIRDEV_STATE_DONGLE_RESET; + next_state = SIRDEV_STATE_DONGLE_RESET; + } + else { + dev->speed = fsm->param; + next_state = SIRDEV_STATE_PORT_SPEED; + } + break; + + case SIRDEV_STATE_DONGLE_RESET: + if (dev->dongle_drv->reset) { + ret = dev->dongle_drv->reset(dev); + if (ret < 0) { + fsm->result = ret; + next_state = SIRDEV_STATE_ERROR; + break; + } + } + else + ret = 0; + if ((delay=ret) == 0) { + /* set serial port according to dongle default speed */ + if (dev->drv->set_speed) + dev->drv->set_speed(dev, dev->speed); + fsm->substate = SIRDEV_STATE_DONGLE_SPEED; + next_state = SIRDEV_STATE_DONGLE_SPEED; + } + break; + + case SIRDEV_STATE_DONGLE_SPEED: + if (dev->dongle_drv->reset) { + ret = dev->dongle_drv->set_speed(dev, fsm->param); + if (ret < 0) { + fsm->result = ret; + next_state = SIRDEV_STATE_ERROR; + break; + } + } + else + ret = 0; + if ((delay=ret) == 0) + next_state = SIRDEV_STATE_PORT_SPEED; + break; + + case SIRDEV_STATE_PORT_SPEED: + /* Finally we are ready to change the serial port speed */ + if (dev->drv->set_speed) + dev->drv->set_speed(dev, dev->speed); + dev->new_speed = 0; + next_state = SIRDEV_STATE_DONE; + break; + + case SIRDEV_STATE_DONE: + /* Signal network layer so it can send more frames */ + netif_wake_queue(dev->netdev); + next_state = SIRDEV_STATE_COMPLETE; + break; + + default: + IRDA_ERROR("%s - undefined state\n", __FUNCTION__); + fsm->result = -EINVAL; + /* fall thru */ + + case SIRDEV_STATE_ERROR: + IRDA_ERROR("%s - error: %d\n", __FUNCTION__, fsm->result); + +#if 0 /* don't enable this before we have netdev->tx_timeout to recover */ + netif_stop_queue(dev->netdev); +#else + netif_wake_queue(dev->netdev); +#endif + /* fall thru */ + + case SIRDEV_STATE_COMPLETE: + /* config change finished, so we are not busy any longer */ + sirdev_enable_rx(dev); + up(&fsm->sem); + return; + } + fsm->state = next_state; + } while(!delay); + + queue_delayed_work(irda_sir_wq, &fsm->work, msecs_to_jiffies(delay)); +} + +/* schedule some device configuration task for execution by kIrDAd + * on behalf of the above state machine. + * can be called from process or interrupt/tasklet context. + */ + +int sirdev_schedule_request(struct sir_dev *dev, int initial_state, unsigned param) +{ + struct sir_fsm *fsm = &dev->fsm; + + IRDA_DEBUG(2, "%s - state=0x%04x / param=%u\n", __FUNCTION__, initial_state, param); + + if (down_trylock(&fsm->sem)) { + if (in_interrupt() || in_atomic() || irqs_disabled()) { + IRDA_DEBUG(1, "%s(), state machine busy!\n", __FUNCTION__); + return -EWOULDBLOCK; + } else + down(&fsm->sem); + } + + if (fsm->state == SIRDEV_STATE_DEAD) { + /* race with sirdev_close should never happen */ + IRDA_ERROR("%s(), instance staled!\n", __FUNCTION__); + up(&fsm->sem); + return -ESTALE; /* or better EPIPE? */ + } + + netif_stop_queue(dev->netdev); + atomic_set(&dev->enable_rx, 0); + + fsm->state = initial_state; + fsm->param = param; + fsm->result = 0; + + INIT_WORK(&fsm->work, sirdev_config_fsm, dev); + queue_work(irda_sir_wq, &fsm->work); + return 0; +} + + /***************************************************************************/ void sirdev_enable_rx(struct sir_dev *dev) @@ -619,10 +911,6 @@ struct sir_dev * sirdev_get_instance(const struct sir_driver *drv, const char *n spin_lock_init(&dev->tx_lock); init_MUTEX(&dev->fsm.sem); - INIT_LIST_HEAD(&dev->fsm.rq.lh_request); - dev->fsm.rq.pending = 0; - init_timer(&dev->fsm.rq.timer); - dev->drv = drv; dev->netdev = ndev; @@ -682,3 +970,22 @@ int sirdev_put_instance(struct sir_dev *dev) } EXPORT_SYMBOL(sirdev_put_instance); +static int __init sir_wq_init(void) +{ + irda_sir_wq = create_singlethread_workqueue("irda_sir_wq"); + if (!irda_sir_wq) + return -ENOMEM; + return 0; +} + +static void __exit sir_wq_exit(void) +{ + destroy_workqueue(irda_sir_wq); +} + +module_init(sir_wq_init); +module_exit(sir_wq_exit); + +MODULE_AUTHOR("Martin Diehl <info@mdiehl.de>"); +MODULE_DESCRIPTION("IrDA SIR core"); +MODULE_LICENSE("GPL"); |