Notify the user with a POLLPRI event when the host issues a
SetLineCoding request so that they can act upon it, for example by
configuring the line coding on a real serial port.
The event is cleared when the user reads the line coding using
USB_F_ACM_GET_LINE_CODING ioctl()
Signed-off-by: Tal Shorer <tal.sho...@gmail.com>
---
drivers/usb/gadget/function/f_acm.c | 38 ++++++++++++++++++++++++++-----------
1 file changed, 27 insertions(+), 11 deletions(-)
diff --git a/drivers/usb/gadget/function/f_acm.c
b/drivers/usb/gadget/function/f_acm.c
index 5feea7c..0983999 100644
--- a/drivers/usb/gadget/function/f_acm.c
+++ b/drivers/usb/gadget/function/f_acm.c
@@ -58,6 +58,9 @@ struct f_acm {
struct usb_request *notify_req;
struct usb_cdc_line_coding port_line_coding; /* 8-N-1 etc */
+ /* we have a SetLineCoding request that the user haven't read yet */
+ bool set_line_coding_pending;
+ wait_queue_head_t set_line_coding_waitq;
/* SetControlLineState request -- CDC 1.1 section 6.2.14 (INPUT) */
u16 port_handshake_bits;
@@ -326,23 +329,19 @@ static void acm_complete_set_line_coding(struct usb_ep
*ep,
} else {
struct usb_cdc_line_coding *value = req->buf;
- /* REVISIT: we currently just remember this data.
- * If we change that,
- * (a) update whatever hardware needs updating,
- * (b) worry about locking. This is information on
- * the order of 9600-8-N-1 ... most of which means
- * nothing unless we control a real RS232 line.
- */
dev_dbg(&cdev->gadget->dev,
"acm ttyGS%d set_line_coding: %d %d %d %d\n",
acm->port_num, le32_to_cpu(value->dwDTERate),
value->bCharFormat, value->bParityType,
value->bDataBits);
if (value->bCharFormat > 2 || value->bParityType > 4 ||
- value->bDataBits < 5 || value->bDataBits > 8)
+ value->bDataBits < 5 || value->bDataBits > 8) {
usb_ep_set_halt(ep);
- else
+ } else {
acm->port_line_coding = *value;
+ acm->set_line_coding_pending = true;
+ wake_up_interruptible(&acm->set_line_coding_waitq);
+ }
}
}
@@ -598,6 +597,19 @@ static void acm_disconnect(struct gserial *port)
acm_notify_serial_state(acm);
}
+static unsigned int acm_poll(struct gserial *port, struct file *file,
+ poll_table *wait)
+{
+ unsigned int mask = 0;
+ struct f_acm *acm = port_to_acm(port);
+
+ poll_wait(file, &acm->set_line_coding_waitq, wait);
+ if (acm->set_line_coding_pending)
+ mask |= POLLPRI;
+ return mask;
+}
+
+
static int acm_send_break(struct gserial *port, int duration)
{
struct f_acm *acm = port_to_acm(port);
@@ -620,10 +632,12 @@ static int acm_ioctl(struct gserial *port, unsigned int
cmd, unsigned long arg)
switch (cmd) {
case USB_F_ACM_GET_LINE_CODING:
if (copy_to_user((__user void *)arg, &acm->port_line_coding,
- sizeof(acm->port_line_coding)))
+ sizeof(acm->port_line_coding))) {
ret = -EFAULT;
- else
+ } else {
ret = 0;
+ acm->set_line_coding_pending = false;
+ }
break;
}
return ret;
@@ -763,11 +777,13 @@ static struct usb_function *acm_alloc_func(struct
usb_function_instance *fi)
return ERR_PTR(-ENOMEM);
spin_lock_init(&acm->lock);
+ init_waitqueue_head(&acm->set_line_coding_waitq);
acm->port.connect = acm_connect;
acm->port.disconnect = acm_disconnect;
acm->port.send_break = acm_send_break;
acm->port.ioctl = acm_ioctl;
+ acm->port.poll = acm_poll;
acm->port.func.name = "acm";
acm->port.func.strings = acm_strings;
--
2.7.4
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
