/* If all data has been read, return 1, else 0 */
static int receive_data(enum port_type index, struct nozomi *dc)
{
u8 buf[RECEIVE_BUF_MAX] = { 0 };
int size;
u32 offset = 4;
struct port *port = &dc->port[index];
void __iomem *addr = port->dl_addr[port->toggle_dl];
struct tty_struct *tty = tty_port_tty_get(&port->port);
int i, ret;
size = __le32_to_cpu(readl(addr));
/* DBG1( "%d bytes port: %d", size, index); */
if (tty && tty_throttled(tty)) {
DBG1("No room in tty, don't read data, don't ack interrupt, "
"disable interrupt");
/* disable interrupt in downlink... */
disable_transmit_dl(index, dc);
ret = 0;
goto put;
}
if (unlikely(size == 0)) {
dev_err(&dc->pdev->dev, "size == 0?\n");
ret = 1;
goto put;
}
while (size > 0) {
read_mem32((u32 *) buf, addr + offset, RECEIVE_BUF_MAX);
if (size == 1) {
tty_insert_flip_char(&port->port, buf[0], TTY_NORMAL);
size = 0;
} else if (size < RECEIVE_BUF_MAX) {
size -= tty_insert_flip_string(&port->port,
(char *)buf, size);
} else {
i = tty_insert_flip_string(&port->port,
(char *)buf, RECEIVE_BUF_MAX);
size -= i;
offset += i;
}
}
set_bit(index, &dc->flip);
ret = 1;
put:
tty_kref_put(tty);
return ret;
}
int tty_unthrottle_safe(struct tty_struct *tty)
{
int ret = 0;
mutex_lock(&tty->throttle_mutex);
if (tty_throttled(tty)) {
if (tty->flow_change != TTY_UNTHROTTLE_SAFE)
ret = 1;
else {
clear_bit(TTY_THROTTLED, &tty->flags);
if (tty->ops->unthrottle)
tty->ops->unthrottle(tty);
}
}
mutex_unlock(&tty->throttle_mutex);
return ret;
}
static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
{
struct serial_state *info = tty->driver_data;
unsigned long flags;
unsigned int cflag = tty->termios.c_cflag;
change_speed(tty, info, old_termios);
/* Handle transition to B0 status */
if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD)) {
info->MCR &= ~(SER_DTR|SER_RTS);
local_irq_save(flags);
rtsdtr_ctrl(info->MCR);
local_irq_restore(flags);
}
/* Handle transition away from B0 status */
if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
info->MCR |= SER_DTR;
if (!C_CRTSCTS(tty) || !tty_throttled(tty))
info->MCR |= SER_RTS;
local_irq_save(flags);
rtsdtr_ctrl(info->MCR);
local_irq_restore(flags);
}
/* Handle turning off CRTSCTS */
if ((old_termios->c_cflag & CRTSCTS) && !C_CRTSCTS(tty)) {
tty->hw_stopped = 0;
rs_start(tty);
}
#if 0
/*
* No need to wake up processes in open wait, since they
* sample the CLOCAL flag once, and don't recheck it.
* XXX It's not clear whether the current behavior is correct
* or not. Hence, this may change.....
*/
if (!(old_termios->c_cflag & CLOCAL) && C_CLOCAL(tty))
wake_up_interruptible(&info->open_wait);
#endif
}
/*
* RX tasklet takes data out of the RX queue and hands it up to the TTY
* layer until it refuses to take any more data (or is throttled back).
* Then it issues reads for any further data.
*
* If the RX queue becomes full enough that no usb_request is queued,
* the OUT endpoint may begin NAKing as soon as its FIFO fills up.
* So QUEUE_SIZE packets plus however many the FIFO holds (usually two)
* can be buffered before the TTY layer's buffers (currently 64 KB).
*/
static void gs_rx_push(unsigned long _port)
{
struct gs_port *port = (void *)_port;
struct tty_struct *tty;
struct list_head *queue = &port->read_queue;
bool disconnect = false;
bool do_push = false;
/* hand any queued data to the tty */
spin_lock_irq(&port->port_lock);
tty = port->port.tty;
while (!list_empty(queue)) {
struct usb_request *req;
req = list_first_entry(queue, struct usb_request, list);
/* leave data queued if tty was rx throttled */
if (tty && tty_throttled(tty))
break;
switch (req->status) {
case -ESHUTDOWN:
disconnect = true;
pr_vdebug("ttyGS%d: shutdown\n", port->port_num);
break;
default:
/* presumably a transient fault */
pr_warn("ttyGS%d: unexpected RX status %d\n",
port->port_num, req->status);
/* FALLTHROUGH */
case 0:
/* normal completion */
break;
}
/* push data to (open) tty */
if (req->actual && tty) {
char *packet = req->buf;
unsigned size = req->actual;
unsigned n;
int count;
/* we may have pushed part of this packet already... */
n = port->n_read;
if (n) {
packet += n;
size -= n;
}
count = tty_insert_flip_string(&port->port, packet,
size);
if (count)
do_push = true;
if (count != size) {
/* stop pushing; TTY layer can't handle more */
port->n_read += count;
pr_vdebug("ttyGS%d: rx block %d/%d\n",
port->port_num, count, req->actual);
break;
}
port->n_read = 0;
}
list_move(&req->list, &port->read_pool);
port->read_started--;
}
/* Push from tty to ldisc; this is handled by a workqueue,
* so we won't get callbacks and can hold port_lock
*/
if (do_push)
tty_flip_buffer_push(&port->port);
/* We want our data queue to become empty ASAP, keeping data
* in the tty and ldisc (not here). If we couldn't push any
* this time around, there may be trouble unless there's an
* implicit tty_unthrottle() call on its way...
*
* REVISIT we should probably add a timer to keep the tasklet
* from starving ... but it's not clear that case ever happens.
*/
if (!list_empty(queue) && tty) {
if (!tty_throttled(tty)) {
if (do_push)
tasklet_schedule(&port->push);
else
pr_warn("ttyGS%d: RX not scheduled?\n",
port->port_num);
}
}
/* If we're still connected, refill the USB RX queue. */
if (!disconnect && port->port_usb)
gs_start_rx(port);
spin_unlock_irq(&port->port_lock);
}
