USB: ark3116: Callbacks for interrupt and bulk read (62d826c8) · Commits · git / linux-net

drivers/usb/serial/ark3116.c

+194 −0

Original line number	Diff line number	Diff line
		@@ -605,6 +605,198 @@ static void ark3116_break_ctl(struct tty_struct *tty, int break_state)
		mutex_unlock(&priv->hw_lock);
		}

		static void ark3116_update_msr(struct usb_serial_port *port, __u8 msr)
		{
		struct ark3116_private *priv = usb_get_serial_port_data(port);
		unsigned long flags;

		spin_lock_irqsave(&priv->status_lock, flags);
		priv->msr = msr;
		spin_unlock_irqrestore(&priv->status_lock, flags);

		if (msr & UART_MSR_ANY_DELTA) {
		/* update input line counters */
		if (msr & UART_MSR_DCTS)
		priv->icount.cts++;
		if (msr & UART_MSR_DDSR)
		priv->icount.dsr++;
		if (msr & UART_MSR_DDCD)
		priv->icount.dcd++;
		if (msr & UART_MSR_TERI)
		priv->icount.rng++;
		wake_up_interruptible(&priv->delta_msr_wait);
		}
		}

		static void ark3116_update_lsr(struct usb_serial_port *port, __u8 lsr)
		{
		struct ark3116_private *priv = usb_get_serial_port_data(port);
		unsigned long flags;

		spin_lock_irqsave(&priv->status_lock, flags);
		/* combine bits */
		priv->lsr \|= lsr;
		spin_unlock_irqrestore(&priv->status_lock, flags);

		if (lsr&UART_LSR_BRK_ERROR_BITS) {
		if (lsr & UART_LSR_BI)
		priv->icount.brk++;
		if (lsr & UART_LSR_FE)
		priv->icount.frame++;
		if (lsr & UART_LSR_PE)
		priv->icount.parity++;
		if (lsr & UART_LSR_OE)
		priv->icount.overrun++;
		}
		}

		static void ark3116_read_int_callback(struct urb *urb)
		{
		struct usb_serial_port *port = urb->context;
		int status = urb->status;
		const __u8 *data = urb->transfer_buffer;
		int result;

		switch (status) {
		case -ECONNRESET:
		case -ENOENT:
		case -ESHUTDOWN:
		/* this urb is terminated, clean up */
		dbg("%s - urb shutting down with status: %d",
		__func__, status);
		return;
		default:
		dbg("%s - nonzero urb status received: %d",
		__func__, status);
		break;
		case 0: /* success */
		/* discovered this by trail and error... */
		if ((urb->actual_length == 4) && (data[0] == 0xe8)) {
		const __u8 id = data[1]&UART_IIR_ID;
		dbg("%s: iir=%02x", __func__, data[1]);
		if (id == UART_IIR_MSI) {
		dbg("%s: msr=%02x", __func__, data[3]);
		ark3116_update_msr(port, data[3]);
		break;
		} else if (id == UART_IIR_RLSI) {
		dbg("%s: lsr=%02x", __func__, data[2]);
		ark3116_update_lsr(port, data[2]);
		break;
		}
		}
		/*
		* Not sure what this data meant...
		*/
		usb_serial_debug_data(debug, &port->dev,
		__func__,
		urb->actual_length,
		urb->transfer_buffer);
		break;
		}

		result = usb_submit_urb(urb, GFP_ATOMIC);
		if (result)
		dev_err(&urb->dev->dev,
		"%s - Error %d submitting interrupt urb\n",
		__func__, result);
		}


		/* Data comes in via the bulk (data) URB, erors/interrupts via the int URB.
		* This means that we cannot be sure which data byte has an associated error
		* condition, so we report an error for all data in the next bulk read.
		*
		* Actually, there might even be a window between the bulk data leaving the
		* ark and reading/resetting the lsr in the read_bulk_callback where an
		* interrupt for the next data block could come in.
		* Without somekind of ordering on the ark, we would have to report the
		* error for the next block of data as well...
		* For now, let's pretend this can't happen.
		*/

		static void send_to_tty(struct tty_struct *tty,
		const unsigned char *chars,
		size_t size, char flag)
		{
		if (size == 0)
		return;
		if (flag == TTY_NORMAL) {
		tty_insert_flip_string(tty, chars, size);
		} else {
		int i;
		for (i = 0; i < size; ++i)
		tty_insert_flip_char(tty, chars[i], flag);
		}
		}

		static void ark3116_read_bulk_callback(struct urb *urb)
		{
		struct usb_serial_port *port = urb->context;
		struct ark3116_private *priv = usb_get_serial_port_data(port);
		const __u8 *data = urb->transfer_buffer;
		int status = urb->status;
		struct tty_struct *tty;
		unsigned long flags;
		int result;
		char flag;
		__u32 lsr;

		switch (status) {
		case -ECONNRESET:
		case -ENOENT:
		case -ESHUTDOWN:
		/* this urb is terminated, clean up */
		dbg("%s - urb shutting down with status: %d",
		__func__, status);
		return;
		default:
		dbg("%s - nonzero urb status received: %d",
		__func__, status);
		break;
		case 0: /* success */

		spin_lock_irqsave(&priv->status_lock, flags);
		lsr = priv->lsr;
		/* clear error bits */
		priv->lsr &= ~UART_LSR_BRK_ERROR_BITS;
		spin_unlock_irqrestore(&priv->status_lock, flags);

		if (unlikely(lsr & UART_LSR_BI))
		flag = TTY_BREAK;
		else if (unlikely(lsr & UART_LSR_PE))
		flag = TTY_PARITY;
		else if (unlikely(lsr & UART_LSR_FE))
		flag = TTY_FRAME;
		else
		flag = TTY_NORMAL;

		tty = tty_port_tty_get(&port->port);
		if (tty) {
		tty_buffer_request_room(tty, urb->actual_length + 1);
		/* overrun is special, not associated with a char */
		if (unlikely(lsr & UART_LSR_OE))
		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
		send_to_tty(tty, data, urb->actual_length, flag);
		tty_flip_buffer_push(tty);
		tty_kref_put(tty);
		}

		/* Throttle the device if requested by tty */
		spin_lock_irqsave(&port->lock, flags);
		port->throttled = port->throttle_req;
		if (port->throttled) {
		spin_unlock_irqrestore(&port->lock, flags);
		return;
		} else
		spin_unlock_irqrestore(&port->lock, flags);
		}
		/* Continue reading from device */
		result = usb_submit_urb(urb, GFP_ATOMIC);
		if (result)
		dev_err(&urb->dev->dev, "%s - failed resubmitting"
		" read urb, error %d\n", __func__, result);
		}

		static struct usb_driver ark3116_driver = {
		.name = "ark3116",
		.probe = usb_serial_probe,
		@@ -631,6 +823,8 @@ static struct usb_serial_driver ark3116_device = {
		.open = ark3116_open,
		.close = ark3116_close,
		.break_ctl = ark3116_break_ctl,
		.read_int_callback = ark3116_read_int_callback,
		.read_bulk_callback = ark3116_read_bulk_callback,
		};

		static int __init ark3116_init(void)