Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / net / irda / stir4200.c
diff --git a/kernel/drivers/net/irda/stir4200.c b/kernel/drivers/net/irda/stir4200.c
new file mode 100644 (file)
index 0000000..83cc48a
--- /dev/null
@@ -0,0 +1,1133 @@
+/*****************************************************************************
+*
+* Filename:      stir4200.c
+* Version:       0.4
+* Description:   Irda SigmaTel USB Dongle
+* Status:        Experimental
+* Author:        Stephen Hemminger <shemminger@osdl.org>
+*
+*      Based on earlier driver by Paul Stewart <stewart@parc.com>
+*
+*      Copyright (C) 2000, Roman Weissgaerber <weissg@vienna.at>
+*      Copyright (C) 2001, Dag Brattli <dag@brattli.net>
+*      Copyright (C) 2001, Jean Tourrilhes <jt@hpl.hp.com>
+*      Copyright (C) 2004, Stephen Hemminger <shemminger@osdl.org>
+*
+*      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.
+*
+*      This program is distributed in the hope that it will be useful,
+*      but WITHOUT ANY WARRANTY; without even the implied warranty of
+*      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+*      GNU General Public License for more details.
+*
+*      You should have received a copy of the GNU General Public License
+*      along with this program; if not, write to the Free Software
+*      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*
+*****************************************************************************/
+
+/*
+ * This dongle does no framing, and requires polling to receive the
+ * data.  The STIr4200 has bulk in and out endpoints just like
+ * usr-irda devices, but the data it sends and receives is raw; like
+ * irtty, it needs to call the wrap and unwrap functions to add and
+ * remove SOF/BOF and escape characters to/from the frame.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+
+#include <linux/kernel.h>
+#include <linux/ktime.h>
+#include <linux/types.h>
+#include <linux/time.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/usb.h>
+#include <linux/crc32.h>
+#include <linux/kthread.h>
+#include <linux/freezer.h>
+#include <net/irda/irda.h>
+#include <net/irda/irda_device.h>
+#include <net/irda/wrapper.h>
+#include <net/irda/crc.h>
+#include <asm/byteorder.h>
+#include <asm/unaligned.h>
+
+MODULE_AUTHOR("Stephen Hemminger <shemminger@linux-foundation.org>");
+MODULE_DESCRIPTION("IrDA-USB Dongle Driver for SigmaTel STIr4200");
+MODULE_LICENSE("GPL");
+
+static int qos_mtt_bits = 0x07;        /* 1 ms or more */
+module_param(qos_mtt_bits, int, 0);
+MODULE_PARM_DESC(qos_mtt_bits, "Minimum Turn Time");
+
+static int rx_sensitivity = 1; /* FIR 0..4, SIR 0..6 */
+module_param(rx_sensitivity, int, 0);
+MODULE_PARM_DESC(rx_sensitivity, "Set Receiver sensitivity (0-6, 0 is most sensitive)");
+
+static int tx_power = 0;       /* 0 = highest ... 3 = lowest */
+module_param(tx_power, int, 0);
+MODULE_PARM_DESC(tx_power, "Set Transmitter power (0-3, 0 is highest power)");
+
+#define STIR_IRDA_HEADER       4
+#define CTRL_TIMEOUT           100        /* milliseconds */
+#define TRANSMIT_TIMEOUT       200        /* milliseconds */
+#define STIR_FIFO_SIZE         4096
+#define FIFO_REGS_SIZE         3
+
+enum FirChars {
+       FIR_CE   = 0x7d,
+       FIR_XBOF = 0x7f,
+       FIR_EOF  = 0x7e,
+};
+
+enum StirRequests {
+       REQ_WRITE_REG =         0x00,
+       REQ_READ_REG =          0x01,
+       REQ_READ_ROM =          0x02,
+       REQ_WRITE_SINGLE =      0x03,
+};
+
+/* Register offsets */
+enum StirRegs {
+       REG_RSVD=0,
+       REG_MODE,
+       REG_PDCLK,
+       REG_CTRL1,
+       REG_CTRL2,
+       REG_FIFOCTL,
+       REG_FIFOLSB,
+       REG_FIFOMSB,
+       REG_DPLL,
+       REG_IRDIG,
+       REG_TEST=15,
+};
+
+enum StirModeMask {
+       MODE_FIR = 0x80,
+       MODE_SIR = 0x20,
+       MODE_ASK = 0x10,
+       MODE_FASTRX = 0x08,
+       MODE_FFRSTEN = 0x04,
+       MODE_NRESET = 0x02,
+       MODE_2400 = 0x01,
+};
+
+enum StirPdclkMask {
+       PDCLK_4000000 = 0x02,
+       PDCLK_115200 = 0x09,
+       PDCLK_57600 = 0x13,
+       PDCLK_38400 = 0x1D,
+       PDCLK_19200 = 0x3B,
+       PDCLK_9600 = 0x77,
+       PDCLK_2400 = 0xDF,
+};
+
+enum StirCtrl1Mask {
+       CTRL1_SDMODE = 0x80,
+       CTRL1_RXSLOW = 0x40,
+       CTRL1_TXPWD = 0x10,
+       CTRL1_RXPWD = 0x08,
+       CTRL1_SRESET = 0x01,
+};
+
+enum StirCtrl2Mask {
+       CTRL2_SPWIDTH = 0x08,
+       CTRL2_REVID = 0x03,
+};
+
+enum StirFifoCtlMask {
+       FIFOCTL_DIR = 0x10,
+       FIFOCTL_CLR = 0x08,
+       FIFOCTL_EMPTY = 0x04,
+};
+
+enum StirDiagMask {
+       IRDIG_RXHIGH = 0x80,
+       IRDIG_RXLOW = 0x40,
+};
+
+enum StirTestMask {
+       TEST_PLLDOWN = 0x80,
+       TEST_LOOPIR = 0x40,
+       TEST_LOOPUSB = 0x20,
+       TEST_TSTENA = 0x10,
+       TEST_TSTOSC = 0x0F,
+};
+
+struct stir_cb {
+        struct usb_device *usbdev;      /* init: probe_irda */
+        struct net_device *netdev;      /* network layer */
+        struct irlap_cb   *irlap;       /* The link layer we are binded to */
+
+        struct qos_info   qos;
+       unsigned          speed;        /* Current speed */
+
+        struct task_struct *thread;     /* transmit thread */
+
+       struct sk_buff    *tx_pending;
+       void              *io_buf;      /* transmit/receive buffer */
+       __u8              *fifo_status;
+
+       iobuff_t          rx_buff;      /* receive unwrap state machine */
+       ktime_t         rx_time;
+       int               receiving;
+       struct urb       *rx_urb;
+};
+
+
+/* These are the currently known USB ids */
+static struct usb_device_id dongles[] = {
+    /* SigmaTel, Inc,  STIr4200 IrDA/USB Bridge */
+    { USB_DEVICE(0x066f, 0x4200) },
+    { }
+};
+
+MODULE_DEVICE_TABLE(usb, dongles);
+
+/* Send control message to set dongle register */
+static int write_reg(struct stir_cb *stir, __u16 reg, __u8 value)
+{
+       struct usb_device *dev = stir->usbdev;
+
+       pr_debug("%s: write reg %d = 0x%x\n",
+                stir->netdev->name, reg, value);
+       return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
+                              REQ_WRITE_SINGLE,
+                              USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_DEVICE,
+                              value, reg, NULL, 0,
+                              CTRL_TIMEOUT);
+}
+
+/* Send control message to read multiple registers */
+static inline int read_reg(struct stir_cb *stir, __u16 reg,
+                   __u8 *data, __u16 count)
+{
+       struct usb_device *dev = stir->usbdev;
+
+       return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
+                              REQ_READ_REG,
+                              USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+                              0, reg, data, count,
+                              CTRL_TIMEOUT);
+}
+
+static inline int isfir(u32 speed)
+{
+       return speed == 4000000;
+}
+
+/*
+ * Prepare a FIR IrDA frame for transmission to the USB dongle.  The
+ * FIR transmit frame is documented in the datasheet.  It consists of
+ * a two byte 0x55 0xAA sequence, two little-endian length bytes, a
+ * sequence of exactly 16 XBOF bytes of 0x7E, two BOF bytes of 0x7E,
+ * then the data escaped as follows:
+ *
+ *    0x7D -> 0x7D 0x5D
+ *    0x7E -> 0x7D 0x5E
+ *    0x7F -> 0x7D 0x5F
+ *
+ * Then, 4 bytes of little endian (stuffed) FCS follow, then two
+ * trailing EOF bytes of 0x7E.
+ */
+static inline __u8 *stuff_fir(__u8 *p, __u8 c)
+{
+       switch(c) {
+       case 0x7d:
+       case 0x7e:
+       case 0x7f:
+               *p++ = 0x7d;
+               c ^= IRDA_TRANS;
+               /* fall through */
+       default:
+               *p++ = c;
+       }
+       return p;
+}
+
+/* Take raw data in skb and put it wrapped into buf */
+static unsigned wrap_fir_skb(const struct sk_buff *skb, __u8 *buf)
+{
+       __u8 *ptr = buf;
+       __u32 fcs = ~(crc32_le(~0, skb->data, skb->len));
+       __u16 wraplen;
+       int i;
+
+       /* Header */
+       buf[0] = 0x55;
+       buf[1] = 0xAA;
+
+       ptr = buf + STIR_IRDA_HEADER;
+       memset(ptr, 0x7f, 16);
+       ptr += 16;
+
+       /* BOF */
+       *ptr++  = 0x7e;
+       *ptr++  = 0x7e;
+
+       /* Address / Control / Information */
+       for (i = 0; i < skb->len; i++)
+               ptr = stuff_fir(ptr, skb->data[i]);
+
+       /* FCS */
+       ptr = stuff_fir(ptr, fcs & 0xff);
+       ptr = stuff_fir(ptr, (fcs >> 8) & 0xff);
+       ptr = stuff_fir(ptr, (fcs >> 16) & 0xff);
+       ptr = stuff_fir(ptr, (fcs >> 24) & 0xff);
+
+       /* EOFs */
+       *ptr++ = 0x7e;
+       *ptr++ = 0x7e;
+
+       /* Total length, minus the header */
+       wraplen = (ptr - buf) - STIR_IRDA_HEADER;
+       buf[2] = wraplen & 0xff;
+       buf[3] = (wraplen >> 8) & 0xff;
+
+       return wraplen + STIR_IRDA_HEADER;
+}
+
+static unsigned wrap_sir_skb(struct sk_buff *skb, __u8 *buf)
+{
+       __u16 wraplen;
+
+       wraplen = async_wrap_skb(skb, buf + STIR_IRDA_HEADER,
+                                STIR_FIFO_SIZE - STIR_IRDA_HEADER);
+       buf[0] = 0x55;
+       buf[1] = 0xAA;
+       buf[2] = wraplen & 0xff;
+       buf[3] = (wraplen >> 8) & 0xff;
+
+       return wraplen + STIR_IRDA_HEADER;
+}
+
+/*
+ * Frame is fully formed in the rx_buff so check crc
+ * and pass up to irlap
+ * setup for next receive
+ */
+static void fir_eof(struct stir_cb *stir)
+{
+       iobuff_t *rx_buff = &stir->rx_buff;
+       int len = rx_buff->len - 4;
+       struct sk_buff *skb, *nskb;
+       __u32 fcs;
+
+       if (unlikely(len <= 0)) {
+               pr_debug("%s: short frame len %d\n",
+                        stir->netdev->name, len);
+
+               ++stir->netdev->stats.rx_errors;
+               ++stir->netdev->stats.rx_length_errors;
+               return;
+       }
+
+       fcs = ~(crc32_le(~0, rx_buff->data, len));
+       if (fcs != get_unaligned_le32(rx_buff->data + len)) {
+               pr_debug("crc error calc 0x%x len %d\n", fcs, len);
+               stir->netdev->stats.rx_errors++;
+               stir->netdev->stats.rx_crc_errors++;
+               return;
+       }
+
+       /* if frame is short then just copy it */
+       if (len < IRDA_RX_COPY_THRESHOLD) {
+               nskb = dev_alloc_skb(len + 1);
+               if (unlikely(!nskb)) {
+                       ++stir->netdev->stats.rx_dropped;
+                       return;
+               }
+               skb_reserve(nskb, 1);
+               skb = nskb;
+               skb_copy_to_linear_data(nskb, rx_buff->data, len);
+       } else {
+               nskb = dev_alloc_skb(rx_buff->truesize);
+               if (unlikely(!nskb)) {
+                       ++stir->netdev->stats.rx_dropped;
+                       return;
+               }
+               skb_reserve(nskb, 1);
+               skb = rx_buff->skb;
+               rx_buff->skb = nskb;
+               rx_buff->head = nskb->data;
+       }
+
+       skb_put(skb, len);
+
+       skb_reset_mac_header(skb);
+       skb->protocol = htons(ETH_P_IRDA);
+       skb->dev = stir->netdev;
+
+       netif_rx(skb);
+
+       stir->netdev->stats.rx_packets++;
+       stir->netdev->stats.rx_bytes += len;
+
+       rx_buff->data = rx_buff->head;
+       rx_buff->len = 0;
+}
+
+/* Unwrap FIR stuffed data and bump it to IrLAP */
+static void stir_fir_chars(struct stir_cb *stir,
+                           const __u8 *bytes, int len)
+{
+       iobuff_t *rx_buff = &stir->rx_buff;
+       int     i;
+
+       for (i = 0; i < len; i++) {
+               __u8    byte = bytes[i];
+
+               switch(rx_buff->state) {
+               case OUTSIDE_FRAME:
+                       /* ignore garbage till start of frame */
+                       if (unlikely(byte != FIR_EOF))
+                               continue;
+                       /* Now receiving frame */
+                       rx_buff->state = BEGIN_FRAME;
+
+                       /* Time to initialize receive buffer */
+                       rx_buff->data = rx_buff->head;
+                       rx_buff->len = 0;
+                       continue;
+
+               case LINK_ESCAPE:
+                       if (byte == FIR_EOF) {
+                               pr_debug("%s: got EOF after escape\n",
+                                        stir->netdev->name);
+                               goto frame_error;
+                       }
+                       rx_buff->state = INSIDE_FRAME;
+                       byte ^= IRDA_TRANS;
+                       break;
+
+               case BEGIN_FRAME:
+                       /* ignore multiple BOF/EOF */
+                       if (byte == FIR_EOF)
+                               continue;
+                       rx_buff->state = INSIDE_FRAME;
+                       rx_buff->in_frame = TRUE;
+
+                       /* fall through */
+               case INSIDE_FRAME:
+                       switch(byte) {
+                       case FIR_CE:
+                               rx_buff->state = LINK_ESCAPE;
+                               continue;
+                       case FIR_XBOF:
+                               /* 0x7f is not used in this framing */
+                               pr_debug("%s: got XBOF without escape\n",
+                                        stir->netdev->name);
+                               goto frame_error;
+                       case FIR_EOF:
+                               rx_buff->state = OUTSIDE_FRAME;
+                               rx_buff->in_frame = FALSE;
+                               fir_eof(stir);
+                               continue;
+                       }
+                       break;
+               }
+
+               /* add byte to rx buffer */
+               if (unlikely(rx_buff->len >= rx_buff->truesize)) {
+                       pr_debug("%s: fir frame exceeds %d\n",
+                                stir->netdev->name, rx_buff->truesize);
+                       ++stir->netdev->stats.rx_over_errors;
+                       goto error_recovery;
+               }
+
+               rx_buff->data[rx_buff->len++] = byte;
+               continue;
+
+       frame_error:
+               ++stir->netdev->stats.rx_frame_errors;
+
+       error_recovery:
+               ++stir->netdev->stats.rx_errors;
+               rx_buff->state = OUTSIDE_FRAME;
+               rx_buff->in_frame = FALSE;
+       }
+}
+
+/* Unwrap SIR stuffed data and bump it up to IrLAP */
+static void stir_sir_chars(struct stir_cb *stir,
+                           const __u8 *bytes, int len)
+{
+       int i;
+
+       for (i = 0; i < len; i++)
+               async_unwrap_char(stir->netdev, &stir->netdev->stats,
+                                 &stir->rx_buff, bytes[i]);
+}
+
+static inline void unwrap_chars(struct stir_cb *stir,
+                               const __u8 *bytes, int length)
+{
+       if (isfir(stir->speed))
+               stir_fir_chars(stir, bytes, length);
+       else
+               stir_sir_chars(stir, bytes, length);
+}
+
+/* Mode parameters for each speed */
+static const struct {
+       unsigned speed;
+       __u8 pdclk;
+} stir_modes[] = {
+        { 2400,    PDCLK_2400 },
+        { 9600,    PDCLK_9600 },
+        { 19200,   PDCLK_19200 },
+        { 38400,   PDCLK_38400 },
+        { 57600,   PDCLK_57600 },
+        { 115200,  PDCLK_115200 },
+        { 4000000, PDCLK_4000000 },
+};
+
+
+/*
+ * Setup chip for speed.
+ *  Called at startup to initialize the chip
+ *  and on speed changes.
+ *
+ * Note: Write multiple registers doesn't appear to work
+ */
+static int change_speed(struct stir_cb *stir, unsigned speed)
+{
+       int i, err;
+       __u8 mode;
+
+       for (i = 0; i < ARRAY_SIZE(stir_modes); ++i) {
+               if (speed == stir_modes[i].speed)
+                       goto found;
+       }
+
+       dev_warn(&stir->netdev->dev, "invalid speed %d\n", speed);
+       return -EINVAL;
+
+ found:
+       pr_debug("speed change from %d to %d\n", stir->speed, speed);
+
+       /* Reset modulator */
+       err = write_reg(stir, REG_CTRL1, CTRL1_SRESET);
+       if (err)
+               goto out;
+
+       /* Undocumented magic to tweak the DPLL */
+       err = write_reg(stir, REG_DPLL, 0x15);
+       if (err)
+               goto out;
+
+       /* Set clock */
+       err = write_reg(stir, REG_PDCLK, stir_modes[i].pdclk);
+       if (err)
+               goto out;
+
+       mode = MODE_NRESET | MODE_FASTRX;
+       if (isfir(speed))
+               mode |= MODE_FIR | MODE_FFRSTEN;
+       else
+               mode |= MODE_SIR;
+
+       if (speed == 2400)
+               mode |= MODE_2400;
+
+       err = write_reg(stir, REG_MODE, mode);
+       if (err)
+               goto out;
+
+       /* This resets TEMIC style transceiver if any. */
+       err = write_reg(stir, REG_CTRL1,
+                       CTRL1_SDMODE | (tx_power & 3) << 1);
+       if (err)
+               goto out;
+
+       err = write_reg(stir, REG_CTRL1, (tx_power & 3) << 1);
+       if (err)
+               goto out;
+
+       /* Reset sensitivity */
+       err = write_reg(stir, REG_CTRL2, (rx_sensitivity & 7) << 5);
+ out:
+       stir->speed = speed;
+       return err;
+}
+
+/*
+ * Called from net/core when new frame is available.
+ */
+static netdev_tx_t stir_hard_xmit(struct sk_buff *skb,
+                                       struct net_device *netdev)
+{
+       struct stir_cb *stir = netdev_priv(netdev);
+
+       netif_stop_queue(netdev);
+
+       /* the IRDA wrapping routines don't deal with non linear skb */
+       SKB_LINEAR_ASSERT(skb);
+
+       skb = xchg(&stir->tx_pending, skb);
+        wake_up_process(stir->thread);
+       
+       /* this should never happen unless stop/wakeup problem */
+       if (unlikely(skb)) {
+               WARN_ON(1);
+               dev_kfree_skb(skb);
+       }
+
+       return NETDEV_TX_OK;
+}
+
+/*
+ * Wait for the transmit FIFO to have space for next data
+ *
+ * If space < 0 then wait till FIFO completely drains.
+ * FYI: can take up to 13 seconds at 2400baud.
+ */
+static int fifo_txwait(struct stir_cb *stir, int space)
+{
+       int err;
+       unsigned long count, status;
+       unsigned long prev_count = 0x1fff;
+
+       /* Read FIFO status and count */
+       for (;; prev_count = count) {
+               err = read_reg(stir, REG_FIFOCTL, stir->fifo_status, 
+                                  FIFO_REGS_SIZE);
+               if (unlikely(err != FIFO_REGS_SIZE)) {
+                       dev_warn(&stir->netdev->dev,
+                                "FIFO register read error: %d\n", err);
+
+                       return err;
+               }
+
+               status = stir->fifo_status[0];
+               count = (unsigned)(stir->fifo_status[2] & 0x1f) << 8 
+                       | stir->fifo_status[1];
+
+               pr_debug("fifo status 0x%lx count %lu\n", status, count);
+
+               /* is fifo receiving already, or empty */
+               if (!(status & FIFOCTL_DIR) ||
+                   (status & FIFOCTL_EMPTY))
+                       return 0;
+
+               if (signal_pending(current))
+                       return -EINTR;
+
+               /* shutting down? */
+               if (!netif_running(stir->netdev) ||
+                   !netif_device_present(stir->netdev))
+                       return -ESHUTDOWN;
+
+               /* only waiting for some space */
+               if (space >= 0 && STIR_FIFO_SIZE - 4 > space + count)
+                       return 0;
+
+               /* queue confused */
+               if (prev_count < count)
+                       break;
+
+               /* estimate transfer time for remaining chars */
+               msleep((count * 8000) / stir->speed);
+       }
+                       
+       err = write_reg(stir, REG_FIFOCTL, FIFOCTL_CLR);
+       if (err) 
+               return err;
+       err = write_reg(stir, REG_FIFOCTL, 0);
+       if (err)
+               return err;
+
+       return 0;
+}
+
+
+/* Wait for turnaround delay before starting transmit.  */
+static void turnaround_delay(const struct stir_cb *stir, long us)
+{
+       long ticks;
+
+       if (us <= 0)
+               return;
+
+       us -= ktime_us_delta(ktime_get(), stir->rx_time);
+
+       if (us < 10)
+               return;
+
+       ticks = us / (1000000 / HZ);
+       if (ticks > 0)
+               schedule_timeout_interruptible(1 + ticks);
+       else
+               udelay(us);
+}
+
+/*
+ * Start receiver by submitting a request to the receive pipe.
+ * If nothing is available it will return after rx_interval.
+ */
+static int receive_start(struct stir_cb *stir)
+{
+       /* reset state */
+       stir->receiving = 1;
+
+       stir->rx_buff.in_frame = FALSE;
+       stir->rx_buff.state = OUTSIDE_FRAME;
+
+       stir->rx_urb->status = 0;
+       return usb_submit_urb(stir->rx_urb, GFP_KERNEL);
+}
+
+/* Stop all pending receive Urb's */
+static void receive_stop(struct stir_cb *stir)
+{
+       stir->receiving = 0;
+       usb_kill_urb(stir->rx_urb);
+
+       if (stir->rx_buff.in_frame) 
+               stir->netdev->stats.collisions++;
+}
+/*
+ * Wrap data in socket buffer and send it.
+ */
+static void stir_send(struct stir_cb *stir, struct sk_buff *skb)
+{
+       unsigned wraplen;
+       int first_frame = 0;
+
+       /* if receiving, need to turnaround */
+       if (stir->receiving) {
+               receive_stop(stir);
+               turnaround_delay(stir, irda_get_mtt(skb));
+               first_frame = 1;
+       }
+
+       if (isfir(stir->speed))
+               wraplen = wrap_fir_skb(skb, stir->io_buf);
+       else
+               wraplen = wrap_sir_skb(skb, stir->io_buf);
+               
+       /* check for space available in fifo */
+       if (!first_frame)
+               fifo_txwait(stir, wraplen);
+
+       stir->netdev->stats.tx_packets++;
+       stir->netdev->stats.tx_bytes += skb->len;
+       stir->netdev->trans_start = jiffies;
+       pr_debug("send %d (%d)\n", skb->len, wraplen);
+
+       if (usb_bulk_msg(stir->usbdev, usb_sndbulkpipe(stir->usbdev, 1),
+                        stir->io_buf, wraplen,
+                        NULL, TRANSMIT_TIMEOUT))
+               stir->netdev->stats.tx_errors++;
+}
+
+/*
+ * Transmit state machine thread
+ */
+static int stir_transmit_thread(void *arg)
+{
+       struct stir_cb *stir = arg;
+       struct net_device *dev = stir->netdev;
+       struct sk_buff *skb;
+
+        while (!kthread_should_stop()) {
+#ifdef CONFIG_PM
+               /* if suspending, then power off and wait */
+               if (unlikely(freezing(current))) {
+                       if (stir->receiving)
+                               receive_stop(stir);
+                       else
+                               fifo_txwait(stir, -1);
+
+                       write_reg(stir, REG_CTRL1, CTRL1_TXPWD|CTRL1_RXPWD);
+
+                       try_to_freeze();
+
+                       if (change_speed(stir, stir->speed))
+                               break;
+               }
+#endif
+
+               /* if something to send? */
+               skb = xchg(&stir->tx_pending, NULL);
+               if (skb) {
+                       unsigned new_speed = irda_get_next_speed(skb);
+                       netif_wake_queue(dev);
+
+                       if (skb->len > 0)
+                               stir_send(stir, skb);
+                       dev_kfree_skb(skb);
+
+                       if ((new_speed != -1) && (stir->speed != new_speed)) {
+                               if (fifo_txwait(stir, -1) ||
+                                   change_speed(stir, new_speed))
+                                       break;
+                       }
+                       continue;
+               }
+
+               /* nothing to send? start receiving */
+               if (!stir->receiving &&
+                   irda_device_txqueue_empty(dev)) {
+                       /* Wait otherwise chip gets confused. */
+                       if (fifo_txwait(stir, -1))
+                               break;
+
+                       if (unlikely(receive_start(stir))) {
+                               if (net_ratelimit())
+                                       dev_info(&dev->dev,
+                                                "%s: receive usb submit failed\n",
+                                                stir->netdev->name);
+                               stir->receiving = 0;
+                               msleep(10);
+                               continue;
+                       }
+               }
+
+               /* sleep if nothing to send */
+                set_current_state(TASK_INTERRUPTIBLE);
+                schedule();
+
+       }
+        return 0;
+}
+
+
+/*
+ * USB bulk receive completion callback.
+ * Wakes up every ms (usb round trip) with wrapped 
+ * data.
+ */
+static void stir_rcv_irq(struct urb *urb)
+{
+       struct stir_cb *stir = urb->context;
+       int err;
+
+       /* in process of stopping, just drop data */
+       if (!netif_running(stir->netdev))
+               return;
+
+       /* unlink, shutdown, unplug, other nasties */
+       if (urb->status != 0) 
+               return;
+
+       if (urb->actual_length > 0) {
+               pr_debug("receive %d\n", urb->actual_length);
+               unwrap_chars(stir, urb->transfer_buffer,
+                            urb->actual_length);
+
+               stir->rx_time = ktime_get();
+       }
+
+       /* kernel thread is stopping receiver don't resubmit */
+       if (!stir->receiving)
+               return;
+
+       /* resubmit existing urb */
+       err = usb_submit_urb(urb, GFP_ATOMIC);
+
+       /* in case of error, the kernel thread will restart us */
+       if (err) {
+               dev_warn(&stir->netdev->dev, "usb receive submit error: %d\n",
+                        err);
+               stir->receiving = 0;
+               wake_up_process(stir->thread);
+       }
+}
+
+/*
+ * Function stir_net_open (dev)
+ *
+ *    Network device is taken up. Usually this is done by "ifconfig irda0 up"
+ */
+static int stir_net_open(struct net_device *netdev)
+{
+       struct stir_cb *stir = netdev_priv(netdev);
+       int err;
+       char hwname[16];
+
+       err = usb_clear_halt(stir->usbdev, usb_sndbulkpipe(stir->usbdev, 1));
+       if (err)
+               goto err_out1;
+       err = usb_clear_halt(stir->usbdev, usb_rcvbulkpipe(stir->usbdev, 2));
+       if (err)
+               goto err_out1;
+
+       err = change_speed(stir, 9600);
+       if (err)
+               goto err_out1;
+
+       err = -ENOMEM;
+
+       /* Initialize for SIR/FIR to copy data directly into skb.  */
+       stir->receiving = 0;
+       stir->rx_buff.truesize = IRDA_SKB_MAX_MTU;
+       stir->rx_buff.skb = dev_alloc_skb(IRDA_SKB_MAX_MTU);
+       if (!stir->rx_buff.skb) 
+               goto err_out1;
+
+       skb_reserve(stir->rx_buff.skb, 1);
+       stir->rx_buff.head = stir->rx_buff.skb->data;
+       stir->rx_time = ktime_get();
+
+       stir->rx_urb = usb_alloc_urb(0, GFP_KERNEL);
+       if (!stir->rx_urb) 
+               goto err_out2;
+
+       stir->io_buf = kmalloc(STIR_FIFO_SIZE, GFP_KERNEL);
+       if (!stir->io_buf)
+               goto err_out3;
+
+       usb_fill_bulk_urb(stir->rx_urb, stir->usbdev,
+                         usb_rcvbulkpipe(stir->usbdev, 2),
+                         stir->io_buf, STIR_FIFO_SIZE,
+                         stir_rcv_irq, stir);
+
+       stir->fifo_status = kmalloc(FIFO_REGS_SIZE, GFP_KERNEL);
+       if (!stir->fifo_status) 
+               goto err_out4;
+               
+       /*
+        * Now that everything should be initialized properly,
+        * Open new IrLAP layer instance to take care of us...
+        * Note : will send immediately a speed change...
+        */
+       sprintf(hwname, "usb#%d", stir->usbdev->devnum);
+       stir->irlap = irlap_open(netdev, &stir->qos, hwname);
+       if (!stir->irlap) {
+               dev_err(&stir->usbdev->dev, "irlap_open failed\n");
+               goto err_out5;
+       }
+
+       /** Start kernel thread for transmit.  */
+       stir->thread = kthread_run(stir_transmit_thread, stir,
+                                  "%s", stir->netdev->name);
+        if (IS_ERR(stir->thread)) {
+                err = PTR_ERR(stir->thread);
+               dev_err(&stir->usbdev->dev, "unable to start kernel thread\n");
+               goto err_out6;
+       }
+
+       netif_start_queue(netdev);
+
+       return 0;
+
+ err_out6:
+       irlap_close(stir->irlap);
+ err_out5:
+       kfree(stir->fifo_status);
+ err_out4:
+       kfree(stir->io_buf);
+ err_out3:
+       usb_free_urb(stir->rx_urb);
+ err_out2:
+       kfree_skb(stir->rx_buff.skb);
+ err_out1:
+       return err;
+}
+
+/*
+ * Function stir_net_close (stir)
+ *
+ *    Network device is taken down. Usually this is done by
+ *    "ifconfig irda0 down"
+ */
+static int stir_net_close(struct net_device *netdev)
+{
+       struct stir_cb *stir = netdev_priv(netdev);
+
+       /* Stop transmit processing */
+       netif_stop_queue(netdev);
+
+       /* Kill transmit thread */
+       kthread_stop(stir->thread);
+       kfree(stir->fifo_status);
+
+       /* Mop up receive urb's */
+       usb_kill_urb(stir->rx_urb);
+       
+       kfree(stir->io_buf);
+       usb_free_urb(stir->rx_urb);
+       kfree_skb(stir->rx_buff.skb);
+
+       /* Stop and remove instance of IrLAP */
+       if (stir->irlap)
+               irlap_close(stir->irlap);
+
+       stir->irlap = NULL;
+
+       return 0;
+}
+
+/*
+ * IOCTLs : Extra out-of-band network commands...
+ */
+static int stir_net_ioctl(struct net_device *netdev, struct ifreq *rq, int cmd)
+{
+       struct if_irda_req *irq = (struct if_irda_req *) rq;
+       struct stir_cb *stir = netdev_priv(netdev);
+       int ret = 0;
+
+       switch (cmd) {
+       case SIOCSBANDWIDTH: /* Set bandwidth */
+               if (!capable(CAP_NET_ADMIN))
+                       return -EPERM;
+
+               /* Check if the device is still there */
+               if (netif_device_present(stir->netdev))
+                       ret = change_speed(stir, irq->ifr_baudrate);
+               break;
+
+       case SIOCSMEDIABUSY: /* Set media busy */
+               if (!capable(CAP_NET_ADMIN))
+                       return -EPERM;
+
+               /* Check if the IrDA stack is still there */
+               if (netif_running(stir->netdev))
+                       irda_device_set_media_busy(stir->netdev, TRUE);
+               break;
+
+       case SIOCGRECEIVING:
+               /* Only approximately true */
+               irq->ifr_receiving = stir->receiving;
+               break;
+
+       default:
+               ret = -EOPNOTSUPP;
+       }
+
+       return ret;
+}
+
+static const struct net_device_ops stir_netdev_ops = {
+       .ndo_open       = stir_net_open,
+       .ndo_stop       = stir_net_close,
+       .ndo_start_xmit = stir_hard_xmit,
+       .ndo_do_ioctl   = stir_net_ioctl,
+};
+
+/*
+ * This routine is called by the USB subsystem for each new device
+ * in the system. We need to check if the device is ours, and in
+ * this case start handling it.
+ * Note : it might be worth protecting this function by a global
+ * spinlock... Or not, because maybe USB already deal with that...
+ */
+static int stir_probe(struct usb_interface *intf,
+                     const struct usb_device_id *id)
+{
+       struct usb_device *dev = interface_to_usbdev(intf);
+       struct stir_cb *stir = NULL;
+       struct net_device *net;
+       int ret = -ENOMEM;
+
+       /* Allocate network device container. */
+       net = alloc_irdadev(sizeof(*stir));
+       if(!net)
+               goto err_out1;
+
+       SET_NETDEV_DEV(net, &intf->dev);
+       stir = netdev_priv(net);
+       stir->netdev = net;
+       stir->usbdev = dev;
+
+       ret = usb_reset_configuration(dev);
+       if (ret != 0) {
+               dev_err(&intf->dev, "usb reset configuration failed\n");
+               goto err_out2;
+       }
+
+       printk(KERN_INFO "SigmaTel STIr4200 IRDA/USB found at address %d, "
+               "Vendor: %x, Product: %x\n",
+              dev->devnum, le16_to_cpu(dev->descriptor.idVendor),
+              le16_to_cpu(dev->descriptor.idProduct));
+
+       /* Initialize QoS for this device */
+       irda_init_max_qos_capabilies(&stir->qos);
+
+       /* That's the Rx capability. */
+       stir->qos.baud_rate.bits       &= IR_2400 | IR_9600 | IR_19200 |
+                                        IR_38400 | IR_57600 | IR_115200 |
+                                        (IR_4000000 << 8);
+       stir->qos.min_turn_time.bits   &= qos_mtt_bits;
+       irda_qos_bits_to_value(&stir->qos);
+
+       /* Override the network functions we need to use */
+       net->netdev_ops = &stir_netdev_ops;
+
+       ret = register_netdev(net);
+       if (ret != 0)
+               goto err_out2;
+
+       dev_info(&intf->dev, "IrDA: Registered SigmaTel device %s\n",
+                net->name);
+
+       usb_set_intfdata(intf, stir);
+
+       return 0;
+
+err_out2:
+       free_netdev(net);
+err_out1:
+       return ret;
+}
+
+/*
+ * The current device is removed, the USB layer tell us to shut it down...
+ */
+static void stir_disconnect(struct usb_interface *intf)
+{
+       struct stir_cb *stir = usb_get_intfdata(intf);
+
+       if (!stir)
+               return;
+
+       unregister_netdev(stir->netdev);
+       free_netdev(stir->netdev);
+
+       usb_set_intfdata(intf, NULL);
+}
+
+#ifdef CONFIG_PM
+/* USB suspend, so power off the transmitter/receiver */
+static int stir_suspend(struct usb_interface *intf, pm_message_t message)
+{
+       struct stir_cb *stir = usb_get_intfdata(intf);
+
+       netif_device_detach(stir->netdev);
+       return 0;
+}
+
+/* Coming out of suspend, so reset hardware */
+static int stir_resume(struct usb_interface *intf)
+{
+       struct stir_cb *stir = usb_get_intfdata(intf);
+
+       netif_device_attach(stir->netdev);
+
+       /* receiver restarted when send thread wakes up */
+       return 0;
+}
+#endif
+
+/*
+ * USB device callbacks
+ */
+static struct usb_driver irda_driver = {
+       .name           = "stir4200",
+       .probe          = stir_probe,
+       .disconnect     = stir_disconnect,
+       .id_table       = dongles,
+#ifdef CONFIG_PM
+       .suspend        = stir_suspend,
+       .resume         = stir_resume,
+#endif
+};
+
+module_usb_driver(irda_driver);