int tty_port_block_til_ready(struct tty_port *port,
struct tty_struct *tty, struct file *filp)
{
int do_clocal = 0, retval;
unsigned long flags;
DEFINE_WAIT(wait);
/* if non-blocking mode is set we can pass directly to open unless
the port has just hung up or is in another error state */
if (tty_io_error(tty)) {
tty_port_set_active(port, 1);
return 0;
}
if (filp == NULL || (filp->f_flags & O_NONBLOCK)) {
/* Indicate we are open */
if (C_BAUD(tty))
tty_port_raise_dtr_rts(port);
tty_port_set_active(port, 1);
return 0;
}
if (C_CLOCAL(tty))
do_clocal = 1;
/* Block waiting until we can proceed. We may need to wait for the
carrier, but we must also wait for any close that is in progress
before the next open may complete */
retval = 0;
/* The port lock protects the port counts */
spin_lock_irqsave(&port->lock, flags);
port->count--;
port->blocked_open++;
spin_unlock_irqrestore(&port->lock, flags);
while (1) {
/* Indicate we are open */
if (C_BAUD(tty) && tty_port_initialized(port))
tty_port_raise_dtr_rts(port);
prepare_to_wait(&port->open_wait, &wait, TASK_INTERRUPTIBLE);
/* Check for a hangup or uninitialised port.
Return accordingly */
if (tty_hung_up_p(filp) || !tty_port_initialized(port)) {
if (port->flags & ASYNC_HUP_NOTIFY)
retval = -EAGAIN;
else
retval = -ERESTARTSYS;
break;
}
/*
* Probe the carrier. For devices with no carrier detect
* tty_port_carrier_raised will always return true.
* Never ask drivers if CLOCAL is set, this causes troubles
* on some hardware.
*/
if (do_clocal || tty_port_carrier_raised(port))
break;
if (signal_pending(current)) {
retval = -ERESTARTSYS;
break;
}
tty_unlock(tty);
schedule();
tty_lock(tty);
}
finish_wait(&port->open_wait, &wait);
/* Update counts. A parallel hangup will have set count to zero and
we must not mess that up further */
spin_lock_irqsave(&port->lock, flags);
if (!tty_hung_up_p(filp))
port->count++;
port->blocked_open--;
spin_unlock_irqrestore(&port->lock, flags);
if (retval == 0)
tty_port_set_active(port, 1);
return retval;
}
int gs_block_til_ready(void *port_, struct file * filp)
{
struct gs_port *gp = port_;
struct tty_port *port = &gp->port;
DECLARE_WAITQUEUE(wait, current);
int retval;
int do_clocal = 0;
int CD;
struct tty_struct *tty;
unsigned long flags;
func_enter ();
if (!port) return 0;
tty = port->tty;
gs_dprintk (GS_DEBUG_BTR, "Entering gs_block_till_ready.\n");
/*
* If the device is in the middle of being closed, then block
* until it's done, and then try again.
*/
if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) {
interruptible_sleep_on(&port->close_wait);
if (port->flags & ASYNC_HUP_NOTIFY)
return -EAGAIN;
else
return -ERESTARTSYS;
}
gs_dprintk (GS_DEBUG_BTR, "after hung up\n");
/*
* If non-blocking mode is set, or the port is not enabled,
* then make the check up front and then exit.
*/
if ((filp->f_flags & O_NONBLOCK) ||
(tty->flags & (1 << TTY_IO_ERROR))) {
port->flags |= ASYNC_NORMAL_ACTIVE;
return 0;
}
gs_dprintk (GS_DEBUG_BTR, "after nonblock\n");
if (C_CLOCAL(tty))
do_clocal = 1;
/*
* Block waiting for the carrier detect and the line to become
* free (i.e., not in use by the callout). While we are in
* this loop, port->count is dropped by one, so that
* rs_close() knows when to free things. We restore it upon
* exit, either normal or abnormal.
*/
retval = 0;
add_wait_queue(&port->open_wait, &wait);
gs_dprintk (GS_DEBUG_BTR, "after add waitq.\n");
spin_lock_irqsave(&port->lock, flags);
if (!tty_hung_up_p(filp)) {
port->count--;
}
port->blocked_open++;
spin_unlock_irqrestore(&port->lock, flags);
while (1) {
CD = tty_port_carrier_raised(port);
gs_dprintk (GS_DEBUG_BTR, "CD is now %d.\n", CD);
set_current_state (TASK_INTERRUPTIBLE);
if (tty_hung_up_p(filp) ||
!(port->flags & ASYNC_INITIALIZED)) {
if (port->flags & ASYNC_HUP_NOTIFY)
retval = -EAGAIN;
else
retval = -ERESTARTSYS;
break;
}
if (!(port->flags & ASYNC_CLOSING) &&
(do_clocal || CD))
break;
gs_dprintk (GS_DEBUG_BTR, "signal_pending is now: %d (%lx)\n",
(int)signal_pending (current), *(long*)(¤t->blocked));
if (signal_pending(current)) {
retval = -ERESTARTSYS;
break;
}
schedule();
}
gs_dprintk (GS_DEBUG_BTR, "Got out of the loop. (%d)\n",
port->blocked_open);
set_current_state (TASK_RUNNING);
remove_wait_queue(&port->open_wait, &wait);
spin_lock_irqsave(&port->lock, flags);
if (!tty_hung_up_p(filp)) {
port->count++;
}
port->blocked_open--;
if (retval == 0)
port->flags |= ASYNC_NORMAL_ACTIVE;
spin_unlock_irqrestore(&port->lock, flags);
func_exit ();
return retval;
}
static int scc_open (struct tty_struct * tty, struct file * filp)
{
int line = tty->index;
int retval;
struct scc_port *port = &scc_ports[line];
int i, channel = port->channel;
unsigned long flags;
SCC_ACCESS_INIT(port);
#if defined(CONFIG_MVME162_SCC) || defined(CONFIG_MVME147_SCC)
static const struct {
unsigned reg, val;
} mvme_init_tab[] = {
/* Values for MVME162 and MVME147 */
/* no parity, 1 stop bit, async, 1:16 */
{ AUX1_CTRL_REG, A1CR_PARITY_NONE|A1CR_MODE_ASYNC_1|A1CR_CLKMODE_x16 },
/* parity error is special cond, ints disabled, no DMA */
{ INT_AND_DMA_REG, IDR_PARERR_AS_SPCOND | IDR_RX_INT_DISAB },
/* Rx 8 bits/char, no auto enable, Rx off */
{ RX_CTRL_REG, RCR_CHSIZE_8 },
/* DTR off, Tx 8 bits/char, RTS off, Tx off */
{ TX_CTRL_REG, TCR_CHSIZE_8 },
/* special features off */
{ AUX2_CTRL_REG, 0 },
{ CLK_CTRL_REG, CCR_RXCLK_BRG | CCR_TXCLK_BRG },
{ DPLL_CTRL_REG, DCR_BRG_ENAB | DCR_BRG_USE_PCLK },
/* Start Rx */
{ RX_CTRL_REG, RCR_RX_ENAB | RCR_CHSIZE_8 },
/* Start Tx */
{ TX_CTRL_REG, TCR_TX_ENAB | TCR_RTS | TCR_DTR | TCR_CHSIZE_8 },
/* Ext/Stat ints: DCD only */
{ INT_CTRL_REG, ICR_ENAB_DCD_INT },
/* Reset Ext/Stat ints */
{ COMMAND_REG, CR_EXTSTAT_RESET },
/* ...again */
{ COMMAND_REG, CR_EXTSTAT_RESET },
};
#endif
#if defined(CONFIG_BVME6000_SCC)
static const struct {
unsigned reg, val;
} bvme_init_tab[] = {
/* Values for BVME6000 */
/* no parity, 1 stop bit, async, 1:16 */
{ AUX1_CTRL_REG, A1CR_PARITY_NONE|A1CR_MODE_ASYNC_1|A1CR_CLKMODE_x16 },
/* parity error is special cond, ints disabled, no DMA */
{ INT_AND_DMA_REG, IDR_PARERR_AS_SPCOND | IDR_RX_INT_DISAB },
/* Rx 8 bits/char, no auto enable, Rx off */
{ RX_CTRL_REG, RCR_CHSIZE_8 },
/* DTR off, Tx 8 bits/char, RTS off, Tx off */
{ TX_CTRL_REG, TCR_CHSIZE_8 },
/* special features off */
{ AUX2_CTRL_REG, 0 },
{ CLK_CTRL_REG, CCR_RTxC_XTAL | CCR_RXCLK_BRG | CCR_TXCLK_BRG },
{ DPLL_CTRL_REG, DCR_BRG_ENAB },
/* Start Rx */
{ RX_CTRL_REG, RCR_RX_ENAB | RCR_CHSIZE_8 },
/* Start Tx */
{ TX_CTRL_REG, TCR_TX_ENAB | TCR_RTS | TCR_DTR | TCR_CHSIZE_8 },
/* Ext/Stat ints: DCD only */
{ INT_CTRL_REG, ICR_ENAB_DCD_INT },
/* Reset Ext/Stat ints */
{ COMMAND_REG, CR_EXTSTAT_RESET },
/* ...again */
{ COMMAND_REG, CR_EXTSTAT_RESET },
};
#endif
if (!(port->gs.port.flags & ASYNC_INITIALIZED)) {
local_irq_save(flags);
#if defined(CONFIG_MVME147_SCC) || defined(CONFIG_MVME162_SCC)
if (MACH_IS_MVME147 || MACH_IS_MVME16x) {
for (i = 0; i < ARRAY_SIZE(mvme_init_tab); ++i)
SCCwrite(mvme_init_tab[i].reg, mvme_init_tab[i].val);
}
#endif
#if defined(CONFIG_BVME6000_SCC)
if (MACH_IS_BVME6000) {
for (i = 0; i < ARRAY_SIZE(bvme_init_tab); ++i)
SCCwrite(bvme_init_tab[i].reg, bvme_init_tab[i].val);
}
#endif
/* remember status register for detection of DCD and CTS changes */
scc_last_status_reg[channel] = SCCread(STATUS_REG);
port->c_dcd = 0; /* Prevent initial 1->0 interrupt */
scc_setsignals (port, 1,1);
local_irq_restore(flags);
}
tty->driver_data = port;
port->gs.port.tty = tty;
port->gs.port.count++;
retval = gs_init_port(&port->gs);
if (retval) {
port->gs.port.count--;
return retval;
}
port->gs.port.flags |= GS_ACTIVE;
retval = gs_block_til_ready(port, filp);
if (retval) {
port->gs.port.count--;
return retval;
}
port->c_dcd = tty_port_carrier_raised(&port->gs.port);
scc_enable_rx_interrupts(port);
return 0;
}
int tty_port_block_til_ready(struct tty_port *port,
struct tty_struct *tty, struct file *filp)
{
int do_clocal = 0, retval;
unsigned long flags;
DEFINE_WAIT(wait);
int cd;
/* block if port is in the process of being closed */
if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) {
wait_event_interruptible_tty(port->close_wait,
!(port->flags & ASYNC_CLOSING));
if (port->flags & ASYNC_HUP_NOTIFY)
return -EAGAIN;
else
return -ERESTARTSYS;
}
/* if non-blocking mode is set we can pass directly to open unless
the port has just hung up or is in another error state */
if (tty->flags & (1 << TTY_IO_ERROR)) {
port->flags |= ASYNC_NORMAL_ACTIVE;
return 0;
}
if (filp->f_flags & O_NONBLOCK) {
/* Indicate we are open */
if (tty->termios->c_cflag & CBAUD)
tty_port_raise_dtr_rts(port);
port->flags |= ASYNC_NORMAL_ACTIVE;
return 0;
}
if (C_CLOCAL(tty))
do_clocal = 1;
/* Block waiting until we can proceed. We may need to wait for the
carrier, but we must also wait for any close that is in progress
before the next open may complete */
retval = 0;
/* The port lock protects the port counts */
spin_lock_irqsave(&port->lock, flags);
if (!tty_hung_up_p(filp))
port->count--;
port->blocked_open++;
spin_unlock_irqrestore(&port->lock, flags);
while (1) {
/* Indicate we are open */
if (tty->termios->c_cflag & CBAUD)
tty_port_raise_dtr_rts(port);
prepare_to_wait(&port->open_wait, &wait, TASK_INTERRUPTIBLE);
/* Check for a hangup or uninitialised port.
Return accordingly */
if (tty_hung_up_p(filp) || !(port->flags & ASYNC_INITIALIZED)) {
if (port->flags & ASYNC_HUP_NOTIFY)
retval = -EAGAIN;
else
retval = -ERESTARTSYS;
break;
}
/* Probe the carrier. For devices with no carrier detect this
will always return true */
cd = tty_port_carrier_raised(port);
if (!(port->flags & ASYNC_CLOSING) &&
(do_clocal || cd))
break;
if (signal_pending(current)) {
retval = -ERESTARTSYS;
break;
}
tty_unlock();
schedule();
tty_lock();
}
finish_wait(&port->open_wait, &wait);
/* Update counts. A parallel hangup will have set count to zero and
we must not mess that up further */
spin_lock_irqsave(&port->lock, flags);
if (!tty_hung_up_p(filp))
port->count++;
port->blocked_open--;
if (retval == 0)
port->flags |= ASYNC_NORMAL_ACTIVE;
spin_unlock_irqrestore(&port->lock, flags);
return retval;
}
