usb gadget: issue notifications from ACM function
Update the CDC-ACM gadget code to support the peripheral-to-host notifications when the tty is opened or closed, or issues a BREAK. The serial framework code calls new generic hooks; right now only CDC-ACM uses those hooks. This resolves several REVISIT comments in the code. (Based on a patch from Felipe Balbi.) Note that this doesn't expose USB_CDC_CAP_BRK to the host, since this code still rejects USB_CDC_REQ_SEND_BREAK control requests for host-to-peripheral BREAK signaling (received via /dev/ttyGS*). Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Felipe Balbi <felipe.balbi@nokia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
David Brownell
Greg Kroah-Hartman
parent
630c7aa801
commit
1f1ba11b64
@ -47,16 +47,37 @@ struct f_acm {
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u8 ctrl_id, data_id;
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u8 port_num;
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u8 pending;
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/* lock is mostly for pending and notify_req ... they get accessed
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* by callbacks both from tty (open/close/break) under its spinlock,
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* and notify_req.complete() which can't use that lock.
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*/
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spinlock_t lock;
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struct acm_ep_descs fs;
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struct acm_ep_descs hs;
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struct usb_ep *notify;
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struct usb_endpoint_descriptor *notify_desc;
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struct usb_request *notify_req;
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struct usb_cdc_line_coding port_line_coding; /* 8-N-1 etc */
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/* SetControlLineState request -- CDC 1.1 section 6.2.14 (INPUT) */
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u16 port_handshake_bits;
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#define RS232_RTS (1 << 1) /* unused with full duplex */
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#define RS232_DTR (1 << 0) /* host is ready for data r/w */
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#define ACM_CTRL_RTS (1 << 1) /* unused with full duplex */
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#define ACM_CTRL_DTR (1 << 0) /* host is ready for data r/w */
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/* SerialState notification -- CDC 1.1 section 6.3.5 (OUTPUT) */
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u16 serial_state;
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#define ACM_CTRL_OVERRUN (1 << 6)
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#define ACM_CTRL_PARITY (1 << 5)
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#define ACM_CTRL_FRAMING (1 << 4)
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#define ACM_CTRL_RI (1 << 3)
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#define ACM_CTRL_BRK (1 << 2)
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#define ACM_CTRL_DSR (1 << 1)
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#define ACM_CTRL_DCD (1 << 0)
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};
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static inline struct f_acm *func_to_acm(struct usb_function *f)
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@ -64,12 +85,17 @@ static inline struct f_acm *func_to_acm(struct usb_function *f)
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return container_of(f, struct f_acm, port.func);
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}
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static inline struct f_acm *port_to_acm(struct gserial *p)
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{
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return container_of(p, struct f_acm, port);
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}
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/*-------------------------------------------------------------------------*/
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/* notification endpoint uses smallish and infrequent fixed-size messages */
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#define GS_LOG2_NOTIFY_INTERVAL 5 /* 1 << 5 == 32 msec */
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#define GS_NOTIFY_MAXPACKET 8
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#define GS_NOTIFY_MAXPACKET 10 /* notification + 2 bytes */
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/* interface and class descriptors: */
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@ -115,7 +141,7 @@ static struct usb_cdc_acm_descriptor acm_descriptor __initdata = {
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.bLength = sizeof(acm_descriptor),
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.bDescriptorType = USB_DT_CS_INTERFACE,
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.bDescriptorSubType = USB_CDC_ACM_TYPE,
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.bmCapabilities = (1 << 1),
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.bmCapabilities = USB_CDC_CAP_LINE,
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};
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static struct usb_cdc_union_desc acm_union_desc __initdata = {
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@ -275,6 +301,11 @@ static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
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/* composite driver infrastructure handles everything except
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* CDC class messages; interface activation uses set_alt().
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*
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* Note CDC spec table 4 lists the ACM request profile. It requires
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* encapsulated command support ... we don't handle any, and respond
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* to them by stalling. Options include get/set/clear comm features
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* (not that useful) and SEND_BREAK.
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*/
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switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
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@ -310,7 +341,7 @@ static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
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value = 0;
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/* FIXME we should not allow data to flow until the
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* host sets the RS232_DTR bit; and when it clears
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* host sets the ACM_CTRL_DTR bit; and when it clears
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* that bit, we should return to that no-flow state.
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*/
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acm->port_handshake_bits = w_value;
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@ -348,9 +379,6 @@ static int acm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
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/* we know alt == 0, so this is an activation or a reset */
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if (intf == acm->ctrl_id) {
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/* REVISIT this may need more work when we start to
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* send notifications ...
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*/
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if (acm->notify->driver_data) {
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VDBG(cdev, "reset acm control interface %d\n", intf);
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usb_ep_disable(acm->notify);
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@ -395,6 +423,128 @@ static void acm_disable(struct usb_function *f)
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/*-------------------------------------------------------------------------*/
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/**
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* acm_cdc_notify - issue CDC notification to host
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* @acm: wraps host to be notified
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* @type: notification type
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* @value: Refer to cdc specs, wValue field.
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* @data: data to be sent
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* @length: size of data
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* Context: irqs blocked, acm->lock held, acm_notify_req non-null
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*
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* Returns zero on sucess or a negative errno.
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*
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* See section 6.3.5 of the CDC 1.1 specification for information
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* about the only notification we issue: SerialState change.
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*/
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static int acm_cdc_notify(struct f_acm *acm, u8 type, u16 value,
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void *data, unsigned length)
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{
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struct usb_ep *ep = acm->notify;
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struct usb_request *req;
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struct usb_cdc_notification *notify;
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const unsigned len = sizeof(*notify) + length;
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void *buf;
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int status;
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req = acm->notify_req;
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acm->notify_req = NULL;
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acm->pending = false;
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req->length = len;
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notify = req->buf;
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buf = notify + 1;
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notify->bmRequestType = USB_DIR_IN | USB_TYPE_CLASS
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| USB_RECIP_INTERFACE;
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notify->bNotificationType = type;
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notify->wValue = cpu_to_le16(value);
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notify->wIndex = cpu_to_le16(acm->ctrl_id);
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notify->wLength = cpu_to_le16(length);
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memcpy(buf, data, length);
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status = usb_ep_queue(ep, req, GFP_ATOMIC);
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if (status < 0) {
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ERROR(acm->port.func.config->cdev,
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"acm ttyGS%d can't notify serial state, %d\n",
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acm->port_num, status);
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acm->notify_req = req;
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}
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return status;
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}
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static int acm_notify_serial_state(struct f_acm *acm)
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{
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struct usb_composite_dev *cdev = acm->port.func.config->cdev;
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int status;
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spin_lock(&acm->lock);
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if (acm->notify_req) {
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DBG(cdev, "acm ttyGS%d serial state %04x\n",
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acm->port_num, acm->serial_state);
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status = acm_cdc_notify(acm, USB_CDC_NOTIFY_SERIAL_STATE,
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0, &acm->serial_state, sizeof(acm->serial_state));
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} else {
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acm->pending = true;
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status = 0;
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}
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spin_unlock(&acm->lock);
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return status;
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}
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static void acm_cdc_notify_complete(struct usb_ep *ep, struct usb_request *req)
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{
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struct f_acm *acm = req->context;
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u8 doit = false;
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/* on this call path we do NOT hold the port spinlock,
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* which is why ACM needs its own spinlock
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*/
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spin_lock(&acm->lock);
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if (req->status != -ESHUTDOWN)
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doit = acm->pending;
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acm->notify_req = req;
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spin_unlock(&acm->lock);
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if (doit)
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acm_notify_serial_state(acm);
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}
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/* connect == the TTY link is open */
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static void acm_connect(struct gserial *port)
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{
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struct f_acm *acm = port_to_acm(port);
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acm->serial_state |= ACM_CTRL_DSR | ACM_CTRL_DCD;
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acm_notify_serial_state(acm);
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}
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static void acm_disconnect(struct gserial *port)
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{
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struct f_acm *acm = port_to_acm(port);
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acm->serial_state &= ~(ACM_CTRL_DSR | ACM_CTRL_DCD);
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acm_notify_serial_state(acm);
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}
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static int acm_send_break(struct gserial *port, int duration)
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{
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struct f_acm *acm = port_to_acm(port);
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u16 state;
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state = acm->serial_state;
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state &= ~ACM_CTRL_BRK;
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if (duration)
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state |= ACM_CTRL_BRK;
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acm->serial_state = state;
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return acm_notify_serial_state(acm);
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}
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/*-------------------------------------------------------------------------*/
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/* ACM function driver setup/binding */
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static int __init
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acm_bind(struct usb_configuration *c, struct usb_function *f)
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@ -443,8 +593,20 @@ acm_bind(struct usb_configuration *c, struct usb_function *f)
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acm->notify = ep;
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ep->driver_data = cdev; /* claim */
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/* allocate notification */
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acm->notify_req = gs_alloc_req(ep,
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sizeof(struct usb_cdc_notification) + 2,
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GFP_KERNEL);
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if (!acm->notify_req)
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goto fail;
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acm->notify_req->complete = acm_cdc_notify_complete;
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acm->notify_req->context = acm;
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/* copy descriptors, and track endpoint copies */
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f->descriptors = usb_copy_descriptors(acm_fs_function);
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if (!f->descriptors)
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goto fail;
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acm->fs.in = usb_find_endpoint(acm_fs_function,
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f->descriptors, &acm_fs_in_desc);
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@ -476,8 +638,6 @@ acm_bind(struct usb_configuration *c, struct usb_function *f)
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f->hs_descriptors, &acm_hs_notify_desc);
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}
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/* FIXME provide a callback for triggering notifications */
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DBG(cdev, "acm ttyGS%d: %s speed IN/%s OUT/%s NOTIFY/%s\n",
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acm->port_num,
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gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
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@ -486,6 +646,9 @@ acm_bind(struct usb_configuration *c, struct usb_function *f)
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return 0;
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fail:
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if (acm->notify_req)
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gs_free_req(acm->notify, acm->notify_req);
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/* we might as well release our claims on endpoints */
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if (acm->notify)
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acm->notify->driver_data = NULL;
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@ -502,10 +665,13 @@ fail:
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static void
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acm_unbind(struct usb_configuration *c, struct usb_function *f)
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{
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struct f_acm *acm = func_to_acm(f);
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if (gadget_is_dualspeed(c->cdev->gadget))
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usb_free_descriptors(f->hs_descriptors);
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usb_free_descriptors(f->descriptors);
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kfree(func_to_acm(f));
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gs_free_req(acm->notify, acm->notify_req);
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kfree(acm);
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}
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/* Some controllers can't support CDC ACM ... */
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@ -569,8 +735,14 @@ int __init acm_bind_config(struct usb_configuration *c, u8 port_num)
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if (!acm)
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return -ENOMEM;
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spin_lock_init(&acm->lock);
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acm->port_num = port_num;
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acm->port.connect = acm_connect;
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acm->port.disconnect = acm_disconnect;
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acm->port.send_break = acm_send_break;
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acm->port.func.name = "acm";
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acm->port.func.strings = acm_strings;
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/* descriptors are per-instance copies */
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@ -60,7 +60,8 @@
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* tty_struct links to the tty/filesystem framework
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*
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* gserial <---> gs_port ... links will be null when the USB link is
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* inactive; managed by gserial_{connect,disconnect}().
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* inactive; managed by gserial_{connect,disconnect}(). each gserial
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* instance can wrap its own USB control protocol.
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* gserial->ioport == usb_ep->driver_data ... gs_port
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* gs_port->port_usb ... gserial
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*
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@ -181,7 +182,7 @@ static void gs_buf_clear(struct gs_buf *gb)
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/*
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* gs_buf_data_avail
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*
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* Return the number of bytes of data available in the circular
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* Return the number of bytes of data written into the circular
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* buffer.
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*/
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static unsigned gs_buf_data_avail(struct gs_buf *gb)
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@ -282,7 +283,7 @@ gs_buf_get(struct gs_buf *gb, char *buf, unsigned count)
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* Allocate a usb_request and its buffer. Returns a pointer to the
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* usb_request or NULL if there is an error.
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*/
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static struct usb_request *
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struct usb_request *
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gs_alloc_req(struct usb_ep *ep, unsigned len, gfp_t kmalloc_flags)
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{
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struct usb_request *req;
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@ -306,7 +307,7 @@ gs_alloc_req(struct usb_ep *ep, unsigned len, gfp_t kmalloc_flags)
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*
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* Free a usb_request and its buffer.
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*/
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static void gs_free_req(struct usb_ep *ep, struct usb_request *req)
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void gs_free_req(struct usb_ep *ep, struct usb_request *req)
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{
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kfree(req->buf);
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usb_ep_free_request(ep, req);
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@ -788,10 +789,13 @@ static int gs_open(struct tty_struct *tty, struct file *file)
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/* if connected, start the I/O stream */
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if (port->port_usb) {
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struct gserial *gser = port->port_usb;
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pr_debug("gs_open: start ttyGS%d\n", port->port_num);
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gs_start_io(port);
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/* REVISIT for ACM, issue "network connected" event */
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if (gser->connect)
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gser->connect(gser);
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}
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pr_debug("gs_open: ttyGS%d (%p,%p)\n", port->port_num, tty, file);
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@ -818,6 +822,7 @@ static int gs_writes_finished(struct gs_port *p)
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static void gs_close(struct tty_struct *tty, struct file *file)
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{
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struct gs_port *port = tty->driver_data;
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struct gserial *gser;
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spin_lock_irq(&port->port_lock);
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@ -837,26 +842,27 @@ static void gs_close(struct tty_struct *tty, struct file *file)
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port->openclose = true;
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port->open_count = 0;
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if (port->port_usb)
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/* REVISIT for ACM, issue "network disconnected" event */;
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gser = port->port_usb;
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if (gser && gser->disconnect)
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gser->disconnect(gser);
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/* wait for circular write buffer to drain, disconnect, or at
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* most GS_CLOSE_TIMEOUT seconds; then discard the rest
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*/
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if (gs_buf_data_avail(&port->port_write_buf) > 0
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&& port->port_usb) {
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if (gs_buf_data_avail(&port->port_write_buf) > 0 && gser) {
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spin_unlock_irq(&port->port_lock);
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wait_event_interruptible_timeout(port->drain_wait,
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gs_writes_finished(port),
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GS_CLOSE_TIMEOUT * HZ);
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spin_lock_irq(&port->port_lock);
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gser = port->port_usb;
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}
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/* Iff we're disconnected, there can be no I/O in flight so it's
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* ok to free the circular buffer; else just scrub it. And don't
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* let the push tasklet fire again until we're re-opened.
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*/
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if (port->port_usb == NULL)
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if (gser == NULL)
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gs_buf_free(&port->port_write_buf);
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else
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gs_buf_clear(&port->port_write_buf);
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@ -974,6 +980,24 @@ static void gs_unthrottle(struct tty_struct *tty)
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spin_unlock_irqrestore(&port->port_lock, flags);
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}
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static int gs_break_ctl(struct tty_struct *tty, int duration)
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{
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struct gs_port *port = tty->driver_data;
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int status = 0;
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struct gserial *gser;
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pr_vdebug("gs_break_ctl: ttyGS%d, send break (%d) \n",
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port->port_num, duration);
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spin_lock_irq(&port->port_lock);
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gser = port->port_usb;
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if (gser && gser->send_break)
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status = gser->send_break(gser, duration);
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spin_unlock_irq(&port->port_lock);
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return status;
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}
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static const struct tty_operations gs_tty_ops = {
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.open = gs_open,
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.close = gs_close,
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@ -983,6 +1007,7 @@ static const struct tty_operations gs_tty_ops = {
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.write_room = gs_write_room,
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.chars_in_buffer = gs_chars_in_buffer,
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.unthrottle = gs_unthrottle,
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.break_ctl = gs_break_ctl,
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};
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/*-------------------------------------------------------------------------*/
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@ -1230,14 +1255,17 @@ int gserial_connect(struct gserial *gser, u8 port_num)
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/* REVISIT if waiting on "carrier detect", signal. */
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/* REVISIT for ACM, issue "network connection" status notification:
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* connected if open_count, else disconnected.
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/* if it's already open, start I/O ... and notify the serial
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* protocol about open/close status (connect/disconnect).
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*/
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/* if it's already open, start I/O */
|
||||
if (port->open_count) {
|
||||
pr_debug("gserial_connect: start ttyGS%d\n", port->port_num);
|
||||
gs_start_io(port);
|
||||
if (gser->connect)
|
||||
gser->connect(gser);
|
||||
} else {
|
||||
if (gser->disconnect)
|
||||
gser->disconnect(gser);
|
||||
}
|
||||
|
||||
spin_unlock_irqrestore(&port->port_lock, flags);
|
||||
|
||||
@ -23,8 +23,7 @@
|
||||
* style I/O using the USB peripheral endpoints listed here, including
|
||||
* hookups to sysfs and /dev for each logical "tty" device.
|
||||
*
|
||||
* REVISIT need TTY --> USB event flow too, so ACM can report open/close
|
||||
* as carrier detect events. Model after ECM. There's more ACM state too.
|
||||
* REVISIT at least ACM could support tiocmget() if needed.
|
||||
*
|
||||
* REVISIT someday, allow multiplexing several TTYs over these endpoints.
|
||||
*/
|
||||
@ -41,8 +40,17 @@ struct gserial {
|
||||
|
||||
/* REVISIT avoid this CDC-ACM support harder ... */
|
||||
struct usb_cdc_line_coding port_line_coding; /* 9600-8-N-1 etc */
|
||||
|
||||
/* notification callbacks */
|
||||
void (*connect)(struct gserial *p);
|
||||
void (*disconnect)(struct gserial *p);
|
||||
int (*send_break)(struct gserial *p, int duration);
|
||||
};
|
||||
|
||||
/* utilities to allocate/free request and buffer */
|
||||
struct usb_request *gs_alloc_req(struct usb_ep *ep, unsigned len, gfp_t flags);
|
||||
void gs_free_req(struct usb_ep *, struct usb_request *req);
|
||||
|
||||
/* port setup/teardown is handled by gadget driver */
|
||||
int gserial_setup(struct usb_gadget *g, unsigned n_ports);
|
||||
void gserial_cleanup(void);
|
||||
|
||||
Loading…
Reference in New Issue
Block a user