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st5481_b.c

/*
 * Driver for ST5481 USB ISDN modem
 *
 * Author       Frode Isaksen
 * Copyright    2001 by Frode Isaksen      <fisaksen@bewan.com>
 *              2001 by Kai Germaschewski  <kai.germaschewski@gmx.de>
 * 
 * This software may be used and distributed according to the terms
 * of the GNU General Public License, incorporated herein by reference.
 *
 */

#include <linux/init.h>
#include <linux/usb.h>
#include <linux/slab.h>
#include <linux/netdevice.h>
#include <linux/bitrev.h>
#include "st5481.h"

static inline void B_L1L2(struct st5481_bcs *bcs, int pr, void *arg)
{
      struct hisax_if *ifc = (struct hisax_if *) &bcs->b_if;

      ifc->l1l2(ifc, pr, arg);
}

/*
 * Encode and transmit next frame.
 */
static void usb_b_out(struct st5481_bcs *bcs,int buf_nr)
{
      struct st5481_b_out *b_out = &bcs->b_out;
      struct st5481_adapter *adapter = bcs->adapter;
      struct urb *urb;
      unsigned int packet_size,offset;
      int len,buf_size,bytes_sent;
      int i;
      struct sk_buff *skb;
      
      if (test_and_set_bit(buf_nr, &b_out->busy)) {
            DBG(4,"ep %d urb %d busy",(bcs->channel+1)*2,buf_nr);
            return;
      }
      urb = b_out->urb[buf_nr];

      // Adjust isoc buffer size according to flow state
      if(b_out->flow_event & (OUT_DOWN | OUT_UNDERRUN)) {
            buf_size = NUM_ISO_PACKETS_B*SIZE_ISO_PACKETS_B_OUT + B_FLOW_ADJUST;
            packet_size = SIZE_ISO_PACKETS_B_OUT + B_FLOW_ADJUST;
            DBG(4,"B%d,adjust flow,add %d bytes",bcs->channel+1,B_FLOW_ADJUST);
      } else if(b_out->flow_event & OUT_UP){
            buf_size = NUM_ISO_PACKETS_B*SIZE_ISO_PACKETS_B_OUT - B_FLOW_ADJUST;
            packet_size = SIZE_ISO_PACKETS_B_OUT - B_FLOW_ADJUST;
            DBG(4,"B%d,adjust flow,remove %d bytes",bcs->channel+1,B_FLOW_ADJUST);
      } else {
            buf_size = NUM_ISO_PACKETS_B*SIZE_ISO_PACKETS_B_OUT;
            packet_size = 8;
      }
      b_out->flow_event = 0;

      len = 0;
      while (len < buf_size) {
            if ((skb = b_out->tx_skb)) {
                  DBG_SKB(0x100, skb);
                  DBG(4,"B%d,len=%d",bcs->channel+1,skb->len);
                  
                  if (bcs->mode == L1_MODE_TRANS) {   
                        bytes_sent = buf_size - len;
                        if (skb->len < bytes_sent)
                              bytes_sent = skb->len;
                        {     /* swap tx bytes to get hearable audio data */
                              register unsigned char *src  = skb->data;
                              register unsigned char *dest = urb->transfer_buffer+len;
                              register unsigned int count;
                              for (count = 0; count < bytes_sent; count++)
                                    *dest++ = bitrev8(*src++);
                        }
                        len += bytes_sent;
                  } else {
                        len += isdnhdlc_encode(&b_out->hdlc_state,
                                           skb->data, skb->len, &bytes_sent,
                                           urb->transfer_buffer+len, buf_size-len);
                  }

                  skb_pull(skb, bytes_sent);

                  if (!skb->len) {
                        // Frame sent
                        b_out->tx_skb = NULL;
                        B_L1L2(bcs, PH_DATA | CONFIRM, (void *)(unsigned long) skb->truesize);
                        dev_kfree_skb_any(skb);

/*                      if (!(bcs->tx_skb = skb_dequeue(&bcs->sq))) { */
/*                            st5481B_sched_event(bcs, B_XMTBUFREADY); */
/*                      } */
                  }
            } else {
                  if (bcs->mode == L1_MODE_TRANS) {
                        memset(urb->transfer_buffer+len, 0xff, buf_size-len);
                        len = buf_size;
                  } else {
                        // Send flags
                        len += isdnhdlc_encode(&b_out->hdlc_state,
                                           NULL, 0, &bytes_sent,
                                           urb->transfer_buffer+len, buf_size-len);
                  }
            }     
      }

      // Prepare the URB
      for (i = 0, offset = 0; offset < len; i++) {
            urb->iso_frame_desc[i].offset = offset;
            urb->iso_frame_desc[i].length = packet_size;
            offset += packet_size;
            packet_size = SIZE_ISO_PACKETS_B_OUT;
      }
      urb->transfer_buffer_length = len;
      urb->number_of_packets = i;
      urb->dev = adapter->usb_dev;

      DBG_ISO_PACKET(0x200,urb);

      SUBMIT_URB(urb, GFP_NOIO);
}

/*
 * Start transfering (flags or data) on the B channel, since
 * FIFO counters has been set to a non-zero value.
 */
static void st5481B_start_xfer(void *context)
{
      struct st5481_bcs *bcs = context;

      DBG(4,"B%d",bcs->channel+1);

      // Start transmitting (flags or data) on B channel

      usb_b_out(bcs,0);
      usb_b_out(bcs,1);
}

/*
 * If the adapter has only 2 LEDs, the green
 * LED will blink with a rate depending
 * on the number of channels opened.
 */
static void led_blink(struct st5481_adapter *adapter)
{
      u_char leds = adapter->leds;

      // 50 frames/sec for each channel
      if (++adapter->led_counter % 50) {
            return;
      }

      if (adapter->led_counter % 100) {
            leds |= GREEN_LED;
      } else {
            leds &= ~GREEN_LED;
      }
      
      st5481_usb_device_ctrl_msg(adapter, GPIO_OUT, leds, NULL, NULL);
}

static void usb_b_out_complete(struct urb *urb)
{
      struct st5481_bcs *bcs = urb->context;
      struct st5481_b_out *b_out = &bcs->b_out;
      struct st5481_adapter *adapter = bcs->adapter;
      int buf_nr;
      
      buf_nr = get_buf_nr(b_out->urb, urb);
      test_and_clear_bit(buf_nr, &b_out->busy);

      if (unlikely(urb->status < 0)) {
            switch (urb->status) {
                  case -ENOENT:
                  case -ESHUTDOWN:
                  case -ECONNRESET:
                        DBG(4,"urb killed status %d", urb->status);
                        return; // Give up
                  default: 
                        WARN("urb status %d",urb->status);
                        if (b_out->busy == 0) {
                              st5481_usb_pipe_reset(adapter, (bcs->channel+1)*2 | USB_DIR_OUT, NULL, NULL);
                        }
                        break;
            }
      }

      usb_b_out(bcs,buf_nr);

      if (adapter->number_of_leds == 2)
            led_blink(adapter);
}

/*
 * Start or stop the transfer on the B channel.
 */
static void st5481B_mode(struct st5481_bcs *bcs, int mode)
{
      struct st5481_b_out *b_out = &bcs->b_out;
      struct st5481_adapter *adapter = bcs->adapter;

      DBG(4,"B%d,mode=%d", bcs->channel + 1, mode);

      if (bcs->mode == mode)
            return;

      bcs->mode = mode;

      // Cancel all USB transfers on this B channel
      usb_unlink_urb(b_out->urb[0]);
      usb_unlink_urb(b_out->urb[1]);
      b_out->busy = 0;

      st5481_in_mode(&bcs->b_in, mode);
      if (bcs->mode != L1_MODE_NULL) {
            // Open the B channel
            if (bcs->mode != L1_MODE_TRANS) {
                  isdnhdlc_out_init(&b_out->hdlc_state, 0, bcs->mode == L1_MODE_HDLC_56K);
            }
            st5481_usb_pipe_reset(adapter, (bcs->channel+1)*2, NULL, NULL);
      
            // Enable B channel interrupts
            st5481_usb_device_ctrl_msg(adapter, FFMSK_B1+(bcs->channel*2), 
                            OUT_UP+OUT_DOWN+OUT_UNDERRUN, NULL, NULL);

            // Enable B channel FIFOs
            st5481_usb_device_ctrl_msg(adapter, OUT_B1_COUNTER+(bcs->channel*2), 32, st5481B_start_xfer, bcs);
            if (adapter->number_of_leds == 4) {
                  if (bcs->channel == 0) {
                        adapter->leds |= B1_LED;
                  } else {
                        adapter->leds |= B2_LED;
                  }
            }
      } else {
            // Disble B channel interrupts
            st5481_usb_device_ctrl_msg(adapter, FFMSK_B1+(bcs->channel*2), 0, NULL, NULL);

            // Disable B channel FIFOs
            st5481_usb_device_ctrl_msg(adapter, OUT_B1_COUNTER+(bcs->channel*2), 0, NULL, NULL);

            if (adapter->number_of_leds == 4) {
                  if (bcs->channel == 0) {
                        adapter->leds &= ~B1_LED;
                  } else {
                        adapter->leds &= ~B2_LED;
                  }
            } else {
                  st5481_usb_device_ctrl_msg(adapter, GPIO_OUT, adapter->leds, NULL, NULL);
            }
            if (b_out->tx_skb) {
                  dev_kfree_skb_any(b_out->tx_skb);
                  b_out->tx_skb = NULL;
            }
            
      }
}

static int st5481_setup_b_out(struct st5481_bcs *bcs)
{
      struct usb_device *dev = bcs->adapter->usb_dev;
      struct usb_interface *intf;
      struct usb_host_interface *altsetting = NULL;
      struct usb_host_endpoint *endpoint;
      struct st5481_b_out *b_out = &bcs->b_out;

      DBG(4,"");

      intf = usb_ifnum_to_if(dev, 0);
      if (intf)
            altsetting = usb_altnum_to_altsetting(intf, 3);
      if (!altsetting)
            return -ENXIO;

      // Allocate URBs and buffers for the B channel out
      endpoint = &altsetting->endpoint[EP_B1_OUT - 1 + bcs->channel * 2];

      DBG(4,"endpoint address=%02x,packet size=%d",
          endpoint->desc.bEndpointAddress, le16_to_cpu(endpoint->desc.wMaxPacketSize));

      // Allocate memory for 8000bytes/sec + extra bytes if underrun
      return st5481_setup_isocpipes(b_out->urb, dev, 
                              usb_sndisocpipe(dev, endpoint->desc.bEndpointAddress),
                              NUM_ISO_PACKETS_B, SIZE_ISO_PACKETS_B_OUT,
                              NUM_ISO_PACKETS_B * SIZE_ISO_PACKETS_B_OUT + B_FLOW_ADJUST,
                              usb_b_out_complete, bcs);
}

static void st5481_release_b_out(struct st5481_bcs *bcs)
{
      struct st5481_b_out *b_out = &bcs->b_out;

      DBG(4,"");

      st5481_release_isocpipes(b_out->urb);
}

int st5481_setup_b(struct st5481_bcs *bcs)
{
      int retval;

      DBG(4,"");

      retval = st5481_setup_b_out(bcs);
      if (retval)
            goto err;
      bcs->b_in.bufsize = HSCX_BUFMAX;
      bcs->b_in.num_packets = NUM_ISO_PACKETS_B;
      bcs->b_in.packet_size = SIZE_ISO_PACKETS_B_IN;
      bcs->b_in.ep = (bcs->channel ? EP_B2_IN : EP_B1_IN) | USB_DIR_IN;
      bcs->b_in.counter = bcs->channel ? IN_B2_COUNTER : IN_B1_COUNTER;
      bcs->b_in.adapter = bcs->adapter;
      bcs->b_in.hisax_if = &bcs->b_if.ifc;
      retval = st5481_setup_in(&bcs->b_in);
      if (retval)
            goto err_b_out;


      return 0;

 err_b_out:
      st5481_release_b_out(bcs);
 err:
      return retval;
}

/*
 * Release buffers and URBs for the B channels
 */
void st5481_release_b(struct st5481_bcs *bcs)
{
      DBG(4,"");

      st5481_release_in(&bcs->b_in);
      st5481_release_b_out(bcs);
}

/*
 * st5481_b_l2l1 is the entry point for upper layer routines that want to
 * transmit on the B channel.  PH_DATA | REQUEST is a normal packet that
 * we either start transmitting (if idle) or queue (if busy).
 * PH_PULL | REQUEST can be called to request a callback message
 * (PH_PULL | CONFIRM)
 * once the link is idle.  After a "pull" callback, the upper layer
 * routines can use PH_PULL | INDICATION to send data.
 */
void st5481_b_l2l1(struct hisax_if *ifc, int pr, void *arg)
{
      struct st5481_bcs *bcs = ifc->priv;
      struct sk_buff *skb = arg;
      long mode;

      DBG(4, "");

      switch (pr) {
      case PH_DATA | REQUEST:
            BUG_ON(bcs->b_out.tx_skb);
            bcs->b_out.tx_skb = skb;
            break;
      case PH_ACTIVATE | REQUEST:
            mode = (long) arg;
            DBG(4,"B%d,PH_ACTIVATE_REQUEST %ld", bcs->channel + 1, mode);
            st5481B_mode(bcs, mode);
            B_L1L2(bcs, PH_ACTIVATE | INDICATION, NULL);
            break;
      case PH_DEACTIVATE | REQUEST:
            DBG(4,"B%d,PH_DEACTIVATE_REQUEST", bcs->channel + 1);
            st5481B_mode(bcs, L1_MODE_NULL);
            B_L1L2(bcs, PH_DEACTIVATE | INDICATION, NULL);
            break;
      default:
            WARN("pr %#x\n", pr);
      }
}

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