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usb serial gadget: CDC ACM fixes

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Based on a patch from <Aurel.Thomi@ruag.com>, this makes the
CDC-ACM support in the serial gadget handle the SET_LINE_CODING
and SET_CONTROL_LINE_STATE requests ... which should improve
interop with at least MS-Windows "usbser.sys" if not some other
ACM host drivers.

It also adds a few REVISIT comments where this code plays a bit
loose with the CDC ACM spec.  If this were used to hook up to a
real RS232 or modem link, those places would need a bit of work.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
David Brownell 2008-04-18 17:37:49 -07:00 committed by Greg Kroah-Hartman
parent d75379a538
commit f371e750c9
1 changed files with 73 additions and 17 deletions
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90
drivers/usb/gadget/serial.c
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@ -135,7 +135,10 @@ struct gs_port {
int port_in_use; /* open/close in progress */
wait_queue_head_t port_write_wait;/* waiting to write */
struct gs_buf *port_write_buf;
struct usb_cdc_line_coding port_line_coding;
struct usb_cdc_line_coding port_line_coding; /* 8-N-1 etc */
u16 port_handshake_bits;
#define RS232_RTS (1 << 1)
#define RS232_DTE (1 << 0)
};
/* the device structure holds info for the USB device */
@ -199,6 +202,8 @@ static int gs_setup_standard(struct usb_gadget *gadget,
static int gs_setup_class(struct usb_gadget *gadget,
const struct usb_ctrlrequest *ctrl);
static void gs_setup_complete(struct usb_ep *ep, struct usb_request *req);
static void gs_setup_complete_set_line_coding(struct usb_ep *ep,
struct usb_request *req);
static void gs_disconnect(struct usb_gadget *gadget);
static int gs_set_config(struct gs_dev *dev, unsigned config);
static void gs_reset_config(struct gs_dev *dev);
@ -406,7 +411,7 @@ static struct usb_cdc_acm_descriptor gs_acm_descriptor = {
.bLength = sizeof(gs_acm_descriptor),
.bDescriptorType = USB_DT_CS_INTERFACE,
.bDescriptorSubType = USB_CDC_ACM_TYPE,
.bmCapabilities = 0,
.bmCapabilities = (1 << 1),
};
static const struct usb_cdc_union_desc gs_union_desc = {
@ -1502,6 +1507,8 @@ static int gs_setup(struct usb_gadget *gadget,
u16 wValue = le16_to_cpu(ctrl->wValue);
u16 wLength = le16_to_cpu(ctrl->wLength);
req->complete = gs_setup_complete;
switch (ctrl->bRequestType & USB_TYPE_MASK) {
case USB_TYPE_STANDARD:
ret = gs_setup_standard(gadget,ctrl);
@ -1679,18 +1686,14 @@ static int gs_setup_class(struct usb_gadget *gadget,
switch (ctrl->bRequest) {
case USB_CDC_REQ_SET_LINE_CODING:
/* FIXME Submit req to read the data; have its completion
* handler copy that data to port->port_line_coding (iff
* it's valid) and maybe pass it on. Until then, fail.
*/
pr_warning("gs_setup: set_line_coding "
"unuspported\n");
if (wLength != sizeof(struct usb_cdc_line_coding))
break;
ret = wLength;
req->complete = gs_setup_complete_set_line_coding;
break;
case USB_CDC_REQ_GET_LINE_CODING:
port = dev->dev_port[0]; /* ACM only has one port */
ret = min(wLength,
(u16)sizeof(struct usb_cdc_line_coding));
ret = min_t(int, wLength, sizeof(struct usb_cdc_line_coding));
if (port) {
spin_lock(&port->port_lock);
memcpy(req->buf, &port->port_line_coding, ret);
@ -1699,15 +1702,27 @@ static int gs_setup_class(struct usb_gadget *gadget,
break;
case USB_CDC_REQ_SET_CONTROL_LINE_STATE:
/* FIXME Submit req to read the data; have its completion
* handler use that to set the state (iff it's valid) and
* maybe pass it on. Until then, fail.
*/
pr_warning("gs_setup: set_control_line_state "
"unuspported\n");
if (wLength != 0)
break;
ret = 0;
if (port) {
/* REVISIT: we currently just remember this data.
* If we change that, update whatever hardware needs
* updating.
*/
spin_lock(&port->port_lock);
port->port_handshake_bits = wValue;
spin_unlock(&port->port_lock);
}
break;
default:
/* NOTE: strictly speaking, we should accept AT-commands
* using SEND_ENCPSULATED_COMMAND/GET_ENCAPSULATED_RESPONSE.
* But our call management descriptor says we don't handle
* call management, so we should be able to get by without
* handling those "required" commands (except by stalling).
*/
pr_err("gs_setup: unknown class request, "
"type=%02x, request=%02x, value=%04x, "
"index=%04x, length=%d\n",
@ -1719,6 +1734,42 @@ static int gs_setup_class(struct usb_gadget *gadget,
return ret;
}
static void gs_setup_complete_set_line_coding(struct usb_ep *ep,
struct usb_request *req)
{
struct gs_dev *dev = ep->driver_data;
struct gs_port *port = dev->dev_port[0]; /* ACM only has one port */
switch (req->status) {
case 0:
/* normal completion */
if (req->actual != sizeof(port->port_line_coding))
usb_ep_set_halt(ep);
else if (port) {
struct usb_cdc_line_coding *value = req->buf;
/* REVISIT: we currently just remember this data.
* If we change that, (a) validate it first, then
* (b) update whatever hardware needs updating.
*/
spin_lock(&port->port_lock);
port->port_line_coding = *value;
spin_unlock(&port->port_lock);
}
break;
case -ESHUTDOWN:
/* disconnect */
gs_free_req(ep, req);
break;
default:
/* unexpected */
break;
}
return;
}
/*
* gs_setup_complete
*/
@ -1906,6 +1957,11 @@ static int gs_set_config(struct gs_dev *dev, unsigned config)
}
}
/* REVISIT the ACM mode should be able to actually *issue* some
* notifications, for at least serial state change events if
* not also for network connection; say so in bmCapabilities.
*/
pr_info("gs_set_config: %s configured, %s speed %s config\n",
GS_LONG_NAME,
gadget->speed == USB_SPEED_HIGH ? "high" : "full",