Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / net / irda / sir_dev.c
diff --git a/kernel/drivers/net/irda/sir_dev.c b/kernel/drivers/net/irda/sir_dev.c
new file mode 100644 (file)
index 0000000..6af26a7
--- /dev/null
@@ -0,0 +1,987 @@
+/*********************************************************************
+ *
+ *     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/hardirq.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.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:
+                       net_err_ratelimited("%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;
+
+       pr_debug("%s(), <%ld>\n", __func__, jiffies);
+
+       do {
+               pr_debug("%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 : 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->set_speed) {
+                               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:
+                       net_err_ratelimited("%s - undefined state\n", __func__);
+                       fsm->result = -EINVAL;
+                       /* fall thru */
+
+               case SIRDEV_STATE_ERROR:
+                       net_err_ratelimited("%s - error: %d\n",
+                                           __func__, 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;
+
+       pr_debug("%s - state=0x%04x / param=%u\n", __func__,
+                initial_state, param);
+
+       if (down_trylock(&fsm->sem)) {
+               if (in_interrupt()  ||  in_atomic()  ||  irqs_disabled()) {
+                       pr_debug("%s(), state machine busy!\n", __func__);
+                       return -EWOULDBLOCK;
+               } else
+                       down(&fsm->sem);
+       }
+
+       if (fsm->state == SIRDEV_STATE_DEAD) {
+               /* race with sirdev_close should never happen */
+               net_err_ratelimited("%s(), instance staled!\n", __func__);
+               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_DELAYED_WORK(&fsm->work, sirdev_config_fsm);
+       queue_delayed_work(irda_sir_wq, &fsm->work, 0);
+       return 0;
+}
+
+
+/***************************************************************************/
+
+void sirdev_enable_rx(struct sir_dev *dev)
+{
+       if (unlikely(atomic_read(&dev->enable_rx)))
+               return;
+
+       /* flush rx-buffer - should also help in case of problems with echo cancelation */
+       dev->rx_buff.data = dev->rx_buff.head;
+       dev->rx_buff.len = 0;
+       dev->rx_buff.in_frame = FALSE;
+       dev->rx_buff.state = OUTSIDE_FRAME;
+       atomic_set(&dev->enable_rx, 1);
+}
+
+static int sirdev_is_receiving(struct sir_dev *dev)
+{
+       if (!atomic_read(&dev->enable_rx))
+               return 0;
+
+       return dev->rx_buff.state != OUTSIDE_FRAME;
+}
+
+int sirdev_set_dongle(struct sir_dev *dev, IRDA_DONGLE type)
+{
+       int err;
+
+       pr_debug("%s : requesting dongle %d.\n", __func__, type);
+
+       err = sirdev_schedule_dongle_open(dev, type);
+       if (unlikely(err))
+               return err;
+       down(&dev->fsm.sem);            /* block until config change completed */
+       err = dev->fsm.result;
+       up(&dev->fsm.sem);
+       return err;
+}
+EXPORT_SYMBOL(sirdev_set_dongle);
+
+/* used by dongle drivers for dongle programming */
+
+int sirdev_raw_write(struct sir_dev *dev, const char *buf, int len)
+{
+       unsigned long flags;
+       int ret;
+
+       if (unlikely(len > dev->tx_buff.truesize))
+               return -ENOSPC;
+
+       spin_lock_irqsave(&dev->tx_lock, flags);        /* serialize with other tx operations */
+       while (dev->tx_buff.len > 0) {                  /* wait until tx idle */
+               spin_unlock_irqrestore(&dev->tx_lock, flags);
+               msleep(10);
+               spin_lock_irqsave(&dev->tx_lock, flags);
+       }
+
+       dev->tx_buff.data = dev->tx_buff.head;
+       memcpy(dev->tx_buff.data, buf, len);    
+       dev->tx_buff.len = len;
+
+       ret = dev->drv->do_write(dev, dev->tx_buff.data, dev->tx_buff.len);
+       if (ret > 0) {
+               pr_debug("%s(), raw-tx started\n", __func__);
+
+               dev->tx_buff.data += ret;
+               dev->tx_buff.len -= ret;
+               dev->raw_tx = 1;
+               ret = len;              /* all data is going to be sent */
+       }
+       spin_unlock_irqrestore(&dev->tx_lock, flags);
+       return ret;
+}
+EXPORT_SYMBOL(sirdev_raw_write);
+
+/* seems some dongle drivers may need this */
+
+int sirdev_raw_read(struct sir_dev *dev, char *buf, int len)
+{
+       int count;
+
+       if (atomic_read(&dev->enable_rx))
+               return -EIO;            /* fail if we expect irda-frames */
+
+       count = (len < dev->rx_buff.len) ? len : dev->rx_buff.len;
+
+       if (count > 0) {
+               memcpy(buf, dev->rx_buff.data, count);
+               dev->rx_buff.data += count;
+               dev->rx_buff.len -= count;
+       }
+
+       /* remaining stuff gets flushed when re-enabling normal rx */
+
+       return count;
+}
+EXPORT_SYMBOL(sirdev_raw_read);
+
+int sirdev_set_dtr_rts(struct sir_dev *dev, int dtr, int rts)
+{
+       int ret = -ENXIO;
+       if (dev->drv->set_dtr_rts)
+               ret =  dev->drv->set_dtr_rts(dev, dtr, rts);
+       return ret;
+}
+EXPORT_SYMBOL(sirdev_set_dtr_rts);
+
+/**********************************************************************/
+
+/* called from client driver - likely with bh-context - to indicate
+ * it made some progress with transmission. Hence we send the next
+ * chunk, if any, or complete the skb otherwise
+ */
+
+void sirdev_write_complete(struct sir_dev *dev)
+{
+       unsigned long flags;
+       struct sk_buff *skb;
+       int actual = 0;
+       int err;
+       
+       spin_lock_irqsave(&dev->tx_lock, flags);
+
+       pr_debug("%s() - dev->tx_buff.len = %d\n",
+                __func__, dev->tx_buff.len);
+
+       if (likely(dev->tx_buff.len > 0))  {
+               /* Write data left in transmit buffer */
+               actual = dev->drv->do_write(dev, dev->tx_buff.data, dev->tx_buff.len);
+
+               if (likely(actual>0)) {
+                       dev->tx_buff.data += actual;
+                       dev->tx_buff.len  -= actual;
+               }
+               else if (unlikely(actual<0)) {
+                       /* could be dropped later when we have tx_timeout to recover */
+                       net_err_ratelimited("%s: drv->do_write failed (%d)\n",
+                                           __func__, actual);
+                       if ((skb=dev->tx_skb) != NULL) {
+                               dev->tx_skb = NULL;
+                               dev_kfree_skb_any(skb);
+                               dev->netdev->stats.tx_errors++;
+                               dev->netdev->stats.tx_dropped++;
+                       }
+                       dev->tx_buff.len = 0;
+               }
+               if (dev->tx_buff.len > 0)
+                       goto done;      /* more data to send later */
+       }
+
+       if (unlikely(dev->raw_tx != 0)) {
+               /* in raw mode we are just done now after the buffer was sent
+                * completely. Since this was requested by some dongle driver
+                * running under the control of the irda-thread we must take
+                * care here not to re-enable the queue. The queue will be
+                * restarted when the irda-thread has completed the request.
+                */
+
+               pr_debug("%s(), raw-tx done\n", __func__);
+               dev->raw_tx = 0;
+               goto done;      /* no post-frame handling in raw mode */
+       }
+
+       /* we have finished now sending this skb.
+        * update statistics and free the skb.
+        * finally we check and trigger a pending speed change, if any.
+        * if not we switch to rx mode and wake the queue for further
+        * packets.
+        * note the scheduled speed request blocks until the lower
+        * client driver and the corresponding hardware has really
+        * finished sending all data (xmit fifo drained f.e.)
+        * before the speed change gets finally done and the queue
+        * re-activated.
+        */
+
+       pr_debug("%s(), finished with frame!\n", __func__);
+               
+       if ((skb=dev->tx_skb) != NULL) {
+               dev->tx_skb = NULL;
+               dev->netdev->stats.tx_packets++;
+               dev->netdev->stats.tx_bytes += skb->len;
+               dev_kfree_skb_any(skb);
+       }
+
+       if (unlikely(dev->new_speed > 0)) {
+               pr_debug("%s(), Changing speed!\n", __func__);
+               err = sirdev_schedule_speed(dev, dev->new_speed);
+               if (unlikely(err)) {
+                       /* should never happen
+                        * forget the speed change and hope the stack recovers
+                        */
+                       net_err_ratelimited("%s - schedule speed change failed: %d\n",
+                                           __func__, err);
+                       netif_wake_queue(dev->netdev);
+               }
+               /* else: success
+                *      speed change in progress now
+                *      on completion dev->new_speed gets cleared,
+                *      rx-reenabled and the queue restarted
+                */
+       }
+       else {
+               sirdev_enable_rx(dev);
+               netif_wake_queue(dev->netdev);
+       }
+
+done:
+       spin_unlock_irqrestore(&dev->tx_lock, flags);
+}
+EXPORT_SYMBOL(sirdev_write_complete);
+
+/* called from client driver - likely with bh-context - to give us
+ * some more received bytes. We put them into the rx-buffer,
+ * normally unwrapping and building LAP-skb's (unless rx disabled)
+ */
+
+int sirdev_receive(struct sir_dev *dev, const unsigned char *cp, size_t count) 
+{
+       if (!dev || !dev->netdev) {
+               net_warn_ratelimited("%s(), not ready yet!\n", __func__);
+               return -1;
+       }
+
+       if (!dev->irlap) {
+               net_warn_ratelimited("%s - too early: %p / %zd!\n",
+                                    __func__, cp, count);
+               return -1;
+       }
+
+       if (cp==NULL) {
+               /* error already at lower level receive
+                * just update stats and set media busy
+                */
+               irda_device_set_media_busy(dev->netdev, TRUE);
+               dev->netdev->stats.rx_dropped++;
+               pr_debug("%s; rx-drop: %zd\n", __func__, count);
+               return 0;
+       }
+
+       /* Read the characters into the buffer */
+       if (likely(atomic_read(&dev->enable_rx))) {
+               while (count--)
+                       /* Unwrap and destuff one byte */
+                       async_unwrap_char(dev->netdev, &dev->netdev->stats,
+                                         &dev->rx_buff, *cp++);
+       } else {
+               while (count--) {
+                       /* rx not enabled: save the raw bytes and never
+                        * trigger any netif_rx. The received bytes are flushed
+                        * later when we re-enable rx but might be read meanwhile
+                        * by the dongle driver.
+                        */
+                       dev->rx_buff.data[dev->rx_buff.len++] = *cp++;
+
+                       /* What should we do when the buffer is full? */
+                       if (unlikely(dev->rx_buff.len == dev->rx_buff.truesize))
+                               dev->rx_buff.len = 0;
+               }
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL(sirdev_receive);
+
+/**********************************************************************/
+
+/* callbacks from network layer */
+
+static netdev_tx_t sirdev_hard_xmit(struct sk_buff *skb,
+                                         struct net_device *ndev)
+{
+       struct sir_dev *dev = netdev_priv(ndev);
+       unsigned long flags;
+       int actual = 0;
+       int err;
+       s32 speed;
+
+       IRDA_ASSERT(dev != NULL, return NETDEV_TX_OK;);
+
+       netif_stop_queue(ndev);
+
+       pr_debug("%s(), skb->len = %d\n", __func__, skb->len);
+
+       speed = irda_get_next_speed(skb);
+       if ((speed != dev->speed) && (speed != -1)) {
+               if (!skb->len) {
+                       err = sirdev_schedule_speed(dev, speed);
+                       if (unlikely(err == -EWOULDBLOCK)) {
+                               /* Failed to initiate the speed change, likely the fsm
+                                * is still busy (pretty unlikely, but...)
+                                * We refuse to accept the skb and return with the queue
+                                * stopped so the network layer will retry after the
+                                * fsm completes and wakes the queue.
+                                */
+                                return NETDEV_TX_BUSY;
+                       }
+                       else if (unlikely(err)) {
+                               /* other fatal error - forget the speed change and
+                                * hope the stack will recover somehow
+                                */
+                                netif_start_queue(ndev);
+                       }
+                       /* else: success
+                        *      speed change in progress now
+                        *      on completion the queue gets restarted
+                        */
+
+                       dev_kfree_skb_any(skb);
+                       return NETDEV_TX_OK;
+               } else
+                       dev->new_speed = speed;
+       }
+
+       /* Init tx buffer*/
+       dev->tx_buff.data = dev->tx_buff.head;
+
+       /* Check problems */
+       if(spin_is_locked(&dev->tx_lock)) {
+               pr_debug("%s(), write not completed\n", __func__);
+       }
+
+       /* serialize with write completion */
+       spin_lock_irqsave(&dev->tx_lock, flags);
+
+        /* Copy skb to tx_buff while wrapping, stuffing and making CRC */
+       dev->tx_buff.len = async_wrap_skb(skb, dev->tx_buff.data, dev->tx_buff.truesize); 
+
+       /* transmission will start now - disable receive.
+        * if we are just in the middle of an incoming frame,
+        * treat it as collision. probably it's a good idea to
+        * reset the rx_buf OUTSIDE_FRAME in this case too?
+        */
+       atomic_set(&dev->enable_rx, 0);
+       if (unlikely(sirdev_is_receiving(dev)))
+               dev->netdev->stats.collisions++;
+
+       actual = dev->drv->do_write(dev, dev->tx_buff.data, dev->tx_buff.len);
+
+       if (likely(actual > 0)) {
+               dev->tx_skb = skb;
+               dev->tx_buff.data += actual;
+               dev->tx_buff.len -= actual;
+       }
+       else if (unlikely(actual < 0)) {
+               /* could be dropped later when we have tx_timeout to recover */
+               net_err_ratelimited("%s: drv->do_write failed (%d)\n",
+                                   __func__, actual);
+               dev_kfree_skb_any(skb);
+               dev->netdev->stats.tx_errors++;
+               dev->netdev->stats.tx_dropped++;
+               netif_wake_queue(ndev);
+       }
+       spin_unlock_irqrestore(&dev->tx_lock, flags);
+
+       return NETDEV_TX_OK;
+}
+
+/* called from network layer with rtnl hold */
+
+static int sirdev_ioctl(struct net_device *ndev, struct ifreq *rq, int cmd)
+{
+       struct if_irda_req *irq = (struct if_irda_req *) rq;
+       struct sir_dev *dev = netdev_priv(ndev);
+       int ret = 0;
+
+       IRDA_ASSERT(dev != NULL, return -1;);
+
+       pr_debug("%s(), %s, (cmd=0x%X)\n", __func__, ndev->name, cmd);
+       
+       switch (cmd) {
+       case SIOCSBANDWIDTH: /* Set bandwidth */
+               if (!capable(CAP_NET_ADMIN))
+                       ret = -EPERM;
+               else
+                       ret = sirdev_schedule_speed(dev, irq->ifr_baudrate);
+               /* cannot sleep here for completion
+                * we are called from network layer with rtnl hold
+                */
+               break;
+
+       case SIOCSDONGLE: /* Set dongle */
+               if (!capable(CAP_NET_ADMIN))
+                       ret = -EPERM;
+               else
+                       ret = sirdev_schedule_dongle_open(dev, irq->ifr_dongle);
+               /* cannot sleep here for completion
+                * we are called from network layer with rtnl hold
+                */
+               break;
+
+       case SIOCSMEDIABUSY: /* Set media busy */
+               if (!capable(CAP_NET_ADMIN))
+                       ret = -EPERM;
+               else
+                       irda_device_set_media_busy(dev->netdev, TRUE);
+               break;
+
+       case SIOCGRECEIVING: /* Check if we are receiving right now */
+               irq->ifr_receiving = sirdev_is_receiving(dev);
+               break;
+
+       case SIOCSDTRRTS:
+               if (!capable(CAP_NET_ADMIN))
+                       ret = -EPERM;
+               else
+                       ret = sirdev_schedule_dtr_rts(dev, irq->ifr_dtr, irq->ifr_rts);
+               /* cannot sleep here for completion
+                * we are called from network layer with rtnl hold
+                */
+               break;
+
+       case SIOCSMODE:
+#if 0
+               if (!capable(CAP_NET_ADMIN))
+                       ret = -EPERM;
+               else
+                       ret = sirdev_schedule_mode(dev, irq->ifr_mode);
+               /* cannot sleep here for completion
+                * we are called from network layer with rtnl hold
+                */
+               break;
+#endif
+       default:
+               ret = -EOPNOTSUPP;
+       }
+       
+       return ret;
+}
+
+/* ----------------------------------------------------------------------------- */
+
+#define SIRBUF_ALLOCSIZE 4269  /* worst case size of a wrapped IrLAP frame */
+
+static int sirdev_alloc_buffers(struct sir_dev *dev)
+{
+       dev->tx_buff.truesize = SIRBUF_ALLOCSIZE;
+       dev->rx_buff.truesize = IRDA_SKB_MAX_MTU; 
+
+       /* Bootstrap ZeroCopy Rx */
+       dev->rx_buff.skb = __netdev_alloc_skb(dev->netdev, dev->rx_buff.truesize,
+                                             GFP_KERNEL);
+       if (dev->rx_buff.skb == NULL)
+               return -ENOMEM;
+       skb_reserve(dev->rx_buff.skb, 1);
+       dev->rx_buff.head = dev->rx_buff.skb->data;
+
+       dev->tx_buff.head = kmalloc(dev->tx_buff.truesize, GFP_KERNEL);
+       if (dev->tx_buff.head == NULL) {
+               kfree_skb(dev->rx_buff.skb);
+               dev->rx_buff.skb = NULL;
+               dev->rx_buff.head = NULL;
+               return -ENOMEM;
+       }
+
+       dev->tx_buff.data = dev->tx_buff.head;
+       dev->rx_buff.data = dev->rx_buff.head;
+       dev->tx_buff.len = 0;
+       dev->rx_buff.len = 0;
+
+       dev->rx_buff.in_frame = FALSE;
+       dev->rx_buff.state = OUTSIDE_FRAME;
+       return 0;
+};
+
+static void sirdev_free_buffers(struct sir_dev *dev)
+{
+       kfree_skb(dev->rx_buff.skb);
+       kfree(dev->tx_buff.head);
+       dev->rx_buff.head = dev->tx_buff.head = NULL;
+       dev->rx_buff.skb = NULL;
+}
+
+static int sirdev_open(struct net_device *ndev)
+{
+       struct sir_dev *dev = netdev_priv(ndev);
+       const struct sir_driver *drv = dev->drv;
+
+       if (!drv)
+               return -ENODEV;
+
+       /* increase the reference count of the driver module before doing serious stuff */
+       if (!try_module_get(drv->owner))
+               return -ESTALE;
+
+       if (sirdev_alloc_buffers(dev))
+               goto errout_dec;
+
+       if (!dev->drv->start_dev  ||  dev->drv->start_dev(dev))
+               goto errout_free;
+
+       sirdev_enable_rx(dev);
+       dev->raw_tx = 0;
+
+       netif_start_queue(ndev);
+       dev->irlap = irlap_open(ndev, &dev->qos, dev->hwname);
+       if (!dev->irlap)
+               goto errout_stop;
+
+       netif_wake_queue(ndev);
+
+       pr_debug("%s - done, speed = %d\n", __func__, dev->speed);
+
+       return 0;
+
+errout_stop:
+       atomic_set(&dev->enable_rx, 0);
+       if (dev->drv->stop_dev)
+               dev->drv->stop_dev(dev);
+errout_free:
+       sirdev_free_buffers(dev);
+errout_dec:
+       module_put(drv->owner);
+       return -EAGAIN;
+}
+
+static int sirdev_close(struct net_device *ndev)
+{
+       struct sir_dev *dev = netdev_priv(ndev);
+       const struct sir_driver *drv;
+
+/* pr_debug("%s\n", __func__); */
+
+       netif_stop_queue(ndev);
+
+       down(&dev->fsm.sem);            /* block on pending config completion */
+
+       atomic_set(&dev->enable_rx, 0);
+
+       if (unlikely(!dev->irlap))
+               goto out;
+       irlap_close(dev->irlap);
+       dev->irlap = NULL;
+
+       drv = dev->drv;
+       if (unlikely(!drv  ||  !dev->priv))
+               goto out;
+
+       if (drv->stop_dev)
+               drv->stop_dev(dev);
+
+       sirdev_free_buffers(dev);
+       module_put(drv->owner);
+
+out:
+       dev->speed = 0;
+       up(&dev->fsm.sem);
+       return 0;
+}
+
+static const struct net_device_ops sirdev_ops = {
+       .ndo_start_xmit = sirdev_hard_xmit,
+       .ndo_open       = sirdev_open,
+       .ndo_stop       = sirdev_close,
+       .ndo_do_ioctl   = sirdev_ioctl,
+};
+/* ----------------------------------------------------------------------------- */
+
+struct sir_dev * sirdev_get_instance(const struct sir_driver *drv, const char *name)
+{
+       struct net_device *ndev;
+       struct sir_dev *dev;
+
+       pr_debug("%s - %s\n", __func__, name);
+
+       /* instead of adding tests to protect against drv->do_write==NULL
+        * at several places we refuse to create a sir_dev instance for
+        * drivers which don't implement do_write.
+        */
+       if (!drv ||  !drv->do_write)
+               return NULL;
+
+       /*
+        *  Allocate new instance of the device
+        */
+       ndev = alloc_irdadev(sizeof(*dev));
+       if (ndev == NULL) {
+               net_err_ratelimited("%s - Can't allocate memory for IrDA control block!\n",
+                                   __func__);
+               goto out;
+       }
+       dev = netdev_priv(ndev);
+
+       irda_init_max_qos_capabilies(&dev->qos);
+       dev->qos.baud_rate.bits = IR_9600|IR_19200|IR_38400|IR_57600|IR_115200;
+       dev->qos.min_turn_time.bits = drv->qos_mtt_bits;
+       irda_qos_bits_to_value(&dev->qos);
+
+       strncpy(dev->hwname, name, sizeof(dev->hwname)-1);
+
+       atomic_set(&dev->enable_rx, 0);
+       dev->tx_skb = NULL;
+
+       spin_lock_init(&dev->tx_lock);
+       sema_init(&dev->fsm.sem, 1);
+
+       dev->drv = drv;
+       dev->netdev = ndev;
+
+       /* Override the network functions we need to use */
+       ndev->netdev_ops = &sirdev_ops;
+
+       if (register_netdev(ndev)) {
+               net_err_ratelimited("%s(), register_netdev() failed!\n",
+                                   __func__);
+               goto out_freenetdev;
+       }
+
+       return dev;
+
+out_freenetdev:
+       free_netdev(ndev);
+out:
+       return NULL;
+}
+EXPORT_SYMBOL(sirdev_get_instance);
+
+int sirdev_put_instance(struct sir_dev *dev)
+{
+       int err = 0;
+
+       pr_debug("%s\n", __func__);
+
+       atomic_set(&dev->enable_rx, 0);
+
+       netif_carrier_off(dev->netdev);
+       netif_device_detach(dev->netdev);
+
+       if (dev->dongle_drv)
+               err = sirdev_schedule_dongle_close(dev);
+       if (err)
+               net_err_ratelimited("%s - error %d\n", __func__, err);
+
+       sirdev_close(dev->netdev);
+
+       down(&dev->fsm.sem);
+       dev->fsm.state = SIRDEV_STATE_DEAD;     /* mark staled */
+       dev->dongle_drv = NULL;
+       dev->priv = NULL;
+       up(&dev->fsm.sem);
+
+       /* Remove netdevice */
+       unregister_netdev(dev->netdev);
+
+       free_netdev(dev->netdev);
+
+       return 0;
+}
+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");