USB: ark3116: Callbacks for interrupt and bulk read

Signed-off-by: Bart Hartgers <bart.hartgers@gmail.com>
Cc: Mike McCormack <mikem@ring3k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 194 insertions, 0 deletions

diff --git a/drivers/usb/serial/ark3116.c b/drivers/usb/serial/ark3116.c
index a7c26990ec67..067daf4db646 100644
--- a/drivers/usb/serial/ark3116.c
+++ b/drivers/usb/serial/ark3116.c
@@ -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)