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Subject[PATCH 6/7] ark3116: (3rd try) Callbacks for interrupt and bulk read
Signed-off-by: Bart Hartgers <bart.hartgers@gmail.com>
---
Index: linux-2.6.32-rc4/drivers/usb/serial/ark3116.c
===================================================================
--- linux-2.6.32-rc4.orig/drivers/usb/serial/ark3116.c 2009-10-25 13:39:15.000000000 +0100
+++ linux-2.6.32-rc4/drivers/usb/serial/ark3116.c 2009-10-25 13:46:48.000000000 +0100
@@ -626,6 +626,190 @@ static void ark3116_break_ctl(struct tty
mutex_unlock(&priv->lock);
}

+static void ark3116_update_msr(struct usb_serial_port *port, __u8 msr)
+{
+ struct ark3116_private *priv = usb_get_serial_port_data(port);
+
+ atomic_set(&priv->msr, msr);
+
+ 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_combine_lsr(struct usb_serial_port *port, __u8 lsr)
+{
+ struct ark3116_private *priv = usb_get_serial_port_data(port);
+
+ /* combine bits */
+ ark3116_atomic_set_clear(lsr, 0, &priv->lsr);
+
+ 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_combine_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;
+ __u8 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 */
+
+ lsr = atomic_read(&priv->lsr);
+ /* clear error bits; works because update_lsr ors the bits */
+ atomic_sub( lsr & UART_LSR_BRK_ERROR_BITS, &priv->lsr);
+
+ 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,
@@ -652,6 +836,8 @@ static struct usb_serial_driver ark3116_
.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)
--


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