From: Oliver Neukum <oneukum@xxxxxxx>
This implements TIOCMIWAIT for TIOCM_DSR, TIOCM_RI and TIOCM_CD
Disconnect is handled as TIOCM_CD or an error.
Signed-off-by: Oliver Neukum <oneukum@xxxxxxx>
---
drivers/usb/class/cdc-acm.c | 81 ++++++++++++++++++++++++++++++++++++++-------
drivers/usb/class/cdc-acm.h | 3 ++
2 files changed, 72 insertions(+), 12 deletions(-)
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 3e7560f..9ac688e 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -262,6 +262,7 @@ static void acm_ctrl_irq(struct urb *urb)
struct usb_cdc_notification *dr = urb->transfer_buffer;
unsigned char *data;
int newctrl;
+ int difference;
int retval;
int status = urb->status;
@@ -302,20 +303,30 @@ static void acm_ctrl_irq(struct urb *urb)
tty_port_tty_hangup(&acm->port, false);
}
+ difference = acm->ctrlin ^ newctrl;
acm->ctrlin = newctrl;
+ acm->oldcount = acm->iocount;
+ smp_wmb();
+
+ if (difference & ACM_CTRL_DSR)
+ acm->iocount.dsr++;
+ if (difference & ACM_CTRL_BRK)
+ acm->iocount.brk++;
+ if (difference & ACM_CTRL_RI)
+ acm->iocount.rng++;
+ if (difference & ACM_CTRL_DCD)
+ acm->iocount.dcd++;
+ if (difference & ACM_CTRL_FRAMING)
+ acm->iocount.frame++;
+ if (difference & ACM_CTRL_PARITY)
+ acm->iocount.parity++;
+ if (difference & ACM_CTRL_OVERRUN)
+ acm->iocount.overrun++;
+
+ if (difference)
+ wake_up_all(&acm->wioctl);
- dev_dbg(&acm->control->dev,
- "%s - input control lines: dcd%c dsr%c break%c "
- "ring%c framing%c parity%c overrun%c\n",
- __func__,
- acm->ctrlin & ACM_CTRL_DCD ? '+' : '-',
- acm->ctrlin & ACM_CTRL_DSR ? '+' : '-',
- acm->ctrlin & ACM_CTRL_BRK ? '+' : '-',
- acm->ctrlin & ACM_CTRL_RI ? '+' : '-',
- acm->ctrlin & ACM_CTRL_FRAMING ? '+' : '-',
- acm->ctrlin & ACM_CTRL_PARITY ? '+' : '-',
- acm->ctrlin & ACM_CTRL_OVERRUN ? '+' : '-');
- break;
+ break;
default:
dev_dbg(&acm->control->dev,
@@ -796,6 +807,47 @@ static int set_serial_info(struct acm *acm,
return retval;
}
+static int wait_serial_change(struct acm *acm, unsigned long arg)
+{
+ int rv = 0;
+ DECLARE_WAITQUEUE(wait, current);
+ struct async_icount old, new;
+
+ if (arg & (TIOCM_DSR | TIOCM_RI | TIOCM_CD ))
+ return -EINVAL;
+ do {
+ old = acm->oldcount;
+ smp_rmb();
+ new = acm->iocount;
+
+ if ((arg & TIOCM_DSR) &&
+ old.dsr != new.dsr)
+ break;
+ if ((arg & TIOCM_CD) &&
+ old.dcd != new.dcd)
+ break;
+ if ((arg & TIOCM_RI) &&
+ old.rng != new.rng)
+ break;
+
+ add_wait_queue(&acm->wioctl, &wait);
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule();
+ remove_wait_queue(&acm->wioctl, &wait);
+ if (acm->disconnected) {
+ if (arg & TIOCM_CD)
+ break;
+ else
+ rv = -ENODEV;
+ } else {
+ if (signal_pending(current))
+ rv = -ERESTARTSYS;
+ }
+ } while (!rv);
+
+ return rv;
+}
+
static int acm_tty_ioctl(struct tty_struct *tty,
unsigned int cmd, unsigned long arg)
{
@@ -809,6 +861,9 @@ static int acm_tty_ioctl(struct tty_struct *tty,
case TIOCSSERIAL:
rv = set_serial_info(acm, (struct serial_struct __user *) arg);
break;
+ case TIOCMIWAIT:
+ rv = wait_serial_change(acm, arg);
+ break;
}
return rv;
@@ -1167,6 +1222,7 @@ made_compressed_probe:
acm->readsize = readsize;
acm->rx_buflimit = num_rx_buf;
INIT_WORK(&acm->work, acm_softint);
+ init_waitqueue_head(&acm->wioctl);
spin_lock_init(&acm->write_lock);
spin_lock_init(&acm->read_lock);
mutex_init(&acm->mutex);
@@ -1383,6 +1439,7 @@ static void acm_disconnect(struct usb_interface *intf)
device_remove_file(&acm->control->dev,
&dev_attr_iCountryCodeRelDate);
}
+ wake_up_all(&acm->wioctl);
device_remove_file(&acm->control->dev, &dev_attr_bmCapabilities);
usb_set_intfdata(acm->control, NULL);
usb_set_intfdata(acm->data, NULL);
diff --git a/drivers/usb/class/cdc-acm.h b/drivers/usb/class/cdc-acm.h
index 0f76e4a..e38dc78 100644
--- a/drivers/usb/class/cdc-acm.h
+++ b/drivers/usb/class/cdc-acm.h
@@ -106,6 +106,9 @@ struct acm {
struct work_struct work; /* work queue entry for line discipline waking up */
unsigned int ctrlin; /* input control lines (DCD, DSR, RI, break, overruns) */
unsigned int ctrlout; /* output control lines (DTR, RTS) */
+ struct async_icount iocount; /* counters for control line changes */
+ struct async_icount oldcount; /* for comparison of counter */
+ wait_queue_head_t wioctl; /* for ioctl */
unsigned int writesize; /* max packet size for the output bulk endpoint */
unsigned int readsize,ctrlsize; /* buffer sizes for freeing */
unsigned int minor; /* acm minor number */
--
1.8.3.1
--
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