mcs7780.c

《linux驱动程序设计从入门到精通》一书中所有的程序代码含驱动和相应的应用程序

	if (!mcs->tx_urb)
		return 0;

	mcs->rx_urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!mcs->rx_urb)
		return 0;

	return 1;
}

/* Sets up state to be initially outside frame, gets receive urb,
 * sets status to successful and then submits the urb to start
 * receiving the data.
 */
static inline int mcs_receive_start(struct mcs_cb *mcs)
{
	mcs->rx_buff.in_frame = FALSE;
	mcs->rx_buff.state = OUTSIDE_FRAME;

	usb_fill_bulk_urb(mcs->rx_urb, mcs->usbdev,
			  usb_rcvbulkpipe(mcs->usbdev, mcs->ep_in),
			  mcs->in_buf, 4096, mcs_receive_irq, mcs);

	mcs->rx_urb->status = 0;
	return usb_submit_urb(mcs->rx_urb, GFP_KERNEL);
}

/* Finds the in and out endpoints for the mcs control block */
static inline int mcs_find_endpoints(struct mcs_cb *mcs,
				     struct usb_host_endpoint *ep, int epnum)
{
	int i;
	int ret = 0;

	/* If no place to store the endpoints just return */
	if (!ep)
		return ret;

	/* cycle through all endpoints, find the first two that are DIR_IN */
	for (i = 0; i < epnum; i++) {
		if (ep[i].desc.bEndpointAddress & USB_DIR_IN)
			mcs->ep_in = ep[i].desc.bEndpointAddress;
		else
			mcs->ep_out = ep[i].desc.bEndpointAddress;

		/* MosChip says that the chip has only two bulk
		 * endpoints. Find one for each direction and move on.
		 */
		if ((mcs->ep_in != 0) && (mcs->ep_out != 0)) {
			ret = 1;
			break;
		}
	}

	return ret;
}

static void mcs_speed_work(struct work_struct *work)
{
	struct mcs_cb *mcs = container_of(work, struct mcs_cb, work);
	struct net_device *netdev = mcs->netdev;

	mcs_speed_change(mcs);
	netif_wake_queue(netdev);
}

/* Function to change the speed of the mcs7780.  Fully supports SIR,
 * MIR, and FIR speeds.
 */
static int mcs_speed_change(struct mcs_cb *mcs)
{
	int ret = 0;
	int rst = 0;
	int cnt = 0;
	__u16 nspeed;
	__u16 rval;

	nspeed = mcs_speed_set[(mcs->new_speed >> 8) & 0x0f];

	do {
		mcs_get_reg(mcs, MCS_RESV_REG, &rval);
	} while(cnt++ < 100 && (rval & MCS_IRINTX));

	if(cnt >= 100) {
		IRDA_ERROR("unable to change speed");
		ret = -EIO;
		goto error;
	}

	mcs_get_reg(mcs, MCS_MODE_REG, &rval);

	/* MINRXPW values recomended by MosChip */
	if (mcs->new_speed <= 115200) {
		rval &= ~MCS_FIR;

		if ((rst = (mcs->speed > 115200)))
			mcs_set_reg(mcs, MCS_MINRXPW_REG, 0);

	} else if (mcs->new_speed <= 1152000) {
		rval &= ~MCS_FIR;

		if ((rst = !(mcs->speed == 576000 || mcs->speed == 1152000)))
			mcs_set_reg(mcs, MCS_MINRXPW_REG, 5);

	} else {
		rval |= MCS_FIR;

		if ((rst = (mcs->speed != 4000000)))
			mcs_set_reg(mcs, MCS_MINRXPW_REG, 5);

	}

	rval &= ~MCS_SPEED_MASK;
	rval |= nspeed;

	ret = mcs_set_reg(mcs, MCS_MODE_REG, rval);
	if (unlikely(ret))
		goto error;

	if (rst)
		switch (mcs->transceiver_type) {
		case MCS_TSC_VISHAY:
			ret = mcs_setup_transceiver_vishay(mcs);
			break;

		case MCS_TSC_SHARP:
			ret = mcs_setup_transceiver_sharp(mcs);
			break;

		case MCS_TSC_AGILENT:
			ret = mcs_setup_transceiver_agilent(mcs);
			break;

		default:
			ret = 1;
			IRDA_WARNING("Unknown transceiver type: %d",
				     mcs->transceiver_type);
		}
	if (unlikely(ret))
		goto error;

	mcs_get_reg(mcs, MCS_MODE_REG, &rval);
	rval &= ~MCS_RESET;
	ret = mcs_set_reg(mcs, MCS_MODE_REG, rval);

	mcs->speed = mcs->new_speed;
	error:
		mcs->new_speed = 0;
		return ret;
}

/* Ioctl calls not supported at this time.  Can be an area of future work. */
static int mcs_net_ioctl(struct net_device *netdev, struct ifreq *rq, int cmd)
{
	/* struct if_irda_req *irq = (struct if_irda_req *)rq; */
	/* struct mcs_cb *mcs = netdev_priv(netdev); */
	int ret = 0;

	switch (cmd) {
	default:
		ret = -EOPNOTSUPP;
	}

	return ret;
}

/* Network device is taken down, done by "ifconfig irda0 down" */
static int mcs_net_close(struct net_device *netdev)
{
	int ret = 0;
	struct mcs_cb *mcs = netdev_priv(netdev);

	/* Stop transmit processing */
	netif_stop_queue(netdev);

	/* kill and free the receive and transmit URBs */
	usb_kill_urb(mcs->rx_urb);
	usb_free_urb(mcs->rx_urb);
	usb_kill_urb(mcs->tx_urb);
	usb_free_urb(mcs->tx_urb);

	/* Stop and remove instance of IrLAP */
	if (mcs->irlap)
		irlap_close(mcs->irlap);

	mcs->irlap = NULL;
	return ret;
}

/* Network device is taken up, done by "ifconfig irda0 up" */
static int mcs_net_open(struct net_device *netdev)
{
	struct mcs_cb *mcs = netdev_priv(netdev);
	char hwname[16];
	int ret = 0;

	ret = usb_clear_halt(mcs->usbdev,
			     usb_sndbulkpipe(mcs->usbdev, mcs->ep_in));
	if (ret)
		goto error1;
	ret = usb_clear_halt(mcs->usbdev,
			     usb_rcvbulkpipe(mcs->usbdev, mcs->ep_out));
	if (ret)
		goto error1;

	ret = mcs_setup_transceiver(mcs);
	if (ret)
		goto error1;

	ret = -ENOMEM;

	/* Initialize for SIR/FIR to copy data directly into skb.  */
	mcs->receiving = 0;
	mcs->rx_buff.truesize = IRDA_SKB_MAX_MTU;
	mcs->rx_buff.skb = dev_alloc_skb(IRDA_SKB_MAX_MTU);
	if (!mcs->rx_buff.skb)
		goto error1;

	skb_reserve(mcs->rx_buff.skb, 1);
	mcs->rx_buff.head = mcs->rx_buff.skb->data;
	do_gettimeofday(&mcs->rx_time);

	/*
	 * 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", mcs->usbdev->devnum);
	mcs->irlap = irlap_open(netdev, &mcs->qos, hwname);
	if (!mcs->irlap) {
		IRDA_ERROR("mcs7780: irlap_open failed");
		goto error2;
	}

	if (!mcs_setup_urbs(mcs))
	goto error3;

	ret = mcs_receive_start(mcs);
	if (ret)
		goto error3;

	netif_start_queue(netdev);
	return 0;

	error3:
		irlap_close(mcs->irlap);
	error2:
		kfree_skb(mcs->rx_buff.skb);
	error1:
		return ret;
}


/* Get device stats for /proc/net/dev and ifconfig */
static struct net_device_stats *mcs_net_get_stats(struct net_device *netdev)
{
	struct mcs_cb *mcs = netdev_priv(netdev);
	return &mcs->stats;
}

/* Receive callback function.  */
static void mcs_receive_irq(struct urb *urb)
{
	__u8 *bytes;
	struct mcs_cb *mcs = urb->context;
	int i;
	int ret;

	if (!netif_running(mcs->netdev))
		return;

	if (urb->status)
		return;

	if (urb->actual_length > 0) {
		bytes = urb->transfer_buffer;

		/* MCS returns frames without BOF and EOF
		 * I assume it returns whole frames.
		 */
		/* SIR speed */
		if(mcs->speed < 576000) {
			async_unwrap_char(mcs->netdev, &mcs->stats,
				  &mcs->rx_buff, 0xc0);

			for (i = 0; i < urb->actual_length; i++)
				async_unwrap_char(mcs->netdev, &mcs->stats,
					  &mcs->rx_buff, bytes[i]);

			async_unwrap_char(mcs->netdev, &mcs->stats,
				  &mcs->rx_buff, 0xc1);
		}
		/* MIR speed */
		else if(mcs->speed == 576000 || mcs->speed == 1152000) {
			mcs_unwrap_mir(mcs, urb->transfer_buffer,
				urb->actual_length);
		}
		/* FIR speed */
		else {
			mcs_unwrap_fir(mcs, urb->transfer_buffer,
				urb->actual_length);
		}
		mcs->netdev->last_rx = jiffies;
		do_gettimeofday(&mcs->rx_time);
	}

	ret = usb_submit_urb(urb, GFP_ATOMIC);
}

/* Transmit callback funtion.  */
static void mcs_send_irq(struct urb *urb)
{
	struct mcs_cb *mcs = urb->context;
	struct net_device *ndev = mcs->netdev;

	if (unlikely(mcs->new_speed))
		schedule_work(&mcs->work);
	else
		netif_wake_queue(ndev);
}

/* Transmit callback funtion.  */
static int mcs_hard_xmit(struct sk_buff *skb, struct net_device *ndev)
{
	unsigned long flags;
	struct mcs_cb *mcs;
	int wraplen;
	int ret = 0;


	if (skb == NULL || ndev == NULL)
		return -EINVAL;

	netif_stop_queue(ndev);
	mcs = netdev_priv(ndev);

	spin_lock_irqsave(&mcs->lock, flags);

	mcs->new_speed = irda_get_next_speed(skb);
	if (likely(mcs->new_speed == mcs->speed))
		mcs->new_speed = 0;

	/* SIR speed */
	if(mcs->speed < 576000) {
		wraplen = mcs_wrap_sir_skb(skb, mcs->out_buf);
	}
	/* MIR speed */
	else if(mcs->speed == 576000 || mcs->speed == 1152000) {
		wraplen = mcs_wrap_mir_skb(skb, mcs->out_buf);
	}
	/* FIR speed */
	else {
		wraplen = mcs_wrap_fir_skb(skb, mcs->out_buf);
	}
	usb_fill_bulk_urb(mcs->tx_urb, mcs->usbdev,
			  usb_sndbulkpipe(mcs->usbdev, mcs->ep_out),
			  mcs->out_buf, wraplen, mcs_send_irq, mcs);

	if ((ret = usb_submit_urb(mcs->tx_urb, GFP_ATOMIC))) {
		IRDA_ERROR("failed tx_urb: %d", ret);
		switch (ret) {
		case -ENODEV:
		case -EPIPE:
			break;
		default:
			mcs->stats.tx_errors++;
			netif_start_queue(ndev);
		}
	} else {
		mcs->stats.tx_packets++;
		mcs->stats.tx_bytes += skb->len;
	}

	dev_kfree_skb(skb);
	spin_unlock_irqrestore(&mcs->lock, flags);
	return ret;
}

/*
 * This function is called by the USB subsystem for each new device in the
 * system.  Need to verify the device and if it is, then start handling it.
 */
static int mcs_probe(struct usb_interface *intf,
		     const struct usb_device_id *id)
{
	struct usb_device *udev = interface_to_usbdev(intf);
	struct net_device *ndev = NULL;
	struct mcs_cb *mcs;
	int ret = -ENOMEM;

	ndev = alloc_irdadev(sizeof(*mcs));
	if (!ndev)
		goto error1;

	IRDA_DEBUG(1, "MCS7780 USB-IrDA bridge found at %d.", udev->devnum);

	/* what is it realy for? */
	SET_MODULE_OWNER(ndev);
	SET_NETDEV_DEV(ndev, &intf->dev);

	ret = usb_reset_configuration(udev);
	if (ret != 0) {
		IRDA_ERROR("mcs7780: usb reset configuration failed");
		goto error2;
	}

	mcs = netdev_priv(ndev);
	mcs->usbdev = udev;
	mcs->netdev = ndev;
	spin_lock_init(&mcs->lock);

	/* Initialize QoS for this device */
	irda_init_max_qos_capabilies(&mcs->qos);

	/* That's the Rx capability. */
	mcs->qos.baud_rate.bits &=
	    IR_2400 | IR_9600 | IR_19200 | IR_38400 | IR_57600 | IR_115200
		| IR_576000 | IR_1152000 | (IR_4000000 << 8);


	mcs->qos.min_turn_time.bits &= qos_mtt_bits;
	irda_qos_bits_to_value(&mcs->qos);

	/* Speed change work initialisation*/
	INIT_WORK(&mcs->work, mcs_speed_work);

	/* Override the network functions we need to use */
	ndev->hard_start_xmit = mcs_hard_xmit;
	ndev->open = mcs_net_open;
	ndev->stop = mcs_net_close;
	ndev->get_stats = mcs_net_get_stats;
	ndev->do_ioctl = mcs_net_ioctl;

	if (!intf->cur_altsetting)
		goto error2;

	ret = mcs_find_endpoints(mcs, intf->cur_altsetting->endpoint,
				 intf->cur_altsetting->desc.bNumEndpoints);
	if (!ret) {
		ret = -ENODEV;
		goto error2;
	}

	ret = register_netdev(ndev);
	if (ret != 0)
		goto error2;

	IRDA_DEBUG(1, "IrDA: Registered MosChip MCS7780 device as %s",
		   ndev->name);

	mcs->transceiver_type = transceiver_type;
	mcs->sir_tweak = sir_tweak;
	mcs->receive_mode = receive_mode;

	usb_set_intfdata(intf, mcs);
	return 0;

	error2:
		free_netdev(ndev);

	error1:
		return ret;
}

/* The current device is removed, the USB layer tells us to shut down. */
static void mcs_disconnect(struct usb_interface *intf)
{
	struct mcs_cb *mcs = usb_get_intfdata(intf);

	if (!mcs)
		return;

	flush_scheduled_work();

	unregister_netdev(mcs->netdev);
	free_netdev(mcs->netdev);

	usb_set_intfdata(intf, NULL);
	IRDA_DEBUG(0, "MCS7780 now disconnected.");
}

/* Module insertion */
static int __init mcs_init(void)
{
	int result;

	/* register this driver with the USB subsystem */
	result = usb_register(&mcs_driver);
	if (result)
		IRDA_ERROR("usb_register failed. Error number %d", result);

	return result;
}
module_init(mcs_init);

/* Module removal */
static void __exit mcs_exit(void)
{
	/* deregister this driver with the USB subsystem */
	usb_deregister(&mcs_driver);
}
module_exit(mcs_exit);