/*
* Check if transmitter is empty
* The port lock is not held.
*/
static unsigned int pmz_tx_empty(struct uart_port *port)
{
struct uart_pmac_port *uap = to_pmz(port);
unsigned char status;
if (ZS_IS_ASLEEP(uap) || uap->node == NULL)
return TIOCSER_TEMT;
status = pmz_peek_status(to_pmz(port));
if (status & Tx_BUF_EMP)
return TIOCSER_TEMT;
return 0;
}
static void __pmz_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
{
struct uart_pmac_port *uap = to_pmz(port);
unsigned long baud;
pmz_debug("pmz: set_termios()\n");
if (ZS_IS_ASLEEP(uap))
return;
memcpy(&uap->termios_cache, termios, sizeof(struct ktermios));
/* XXX Check which revs of machines actually allow 1 and 4Mb speeds
* on the IR dongle. Note that the IRTTY driver currently doesn't know
* about the FIR mode and high speed modes. So these are unused. For
* implementing proper support for these, we should probably add some
* DMA as well, at least on the Rx side, which isn't a simple thing
* at this point.
*/
if (ZS_IS_IRDA(uap)) {
/* Calc baud rate */
baud = uart_get_baud_rate(port, termios, old, 1200, 4000000);
pmz_debug("pmz: switch IRDA to %ld bauds\n", baud);
/* Cet the irda codec to the right rate */
pmz_irda_setup(uap, &baud);
/* Set final baud rate */
pmz_convert_to_zs(uap, termios->c_cflag, termios->c_iflag, baud);
pmz_load_zsregs(uap, uap->curregs);
zssync(uap);
} else {
baud = uart_get_baud_rate(port, termios, old, 1200, 230400);
pmz_convert_to_zs(uap, termios->c_cflag, termios->c_iflag, baud);
/* Make sure modem status interrupts are correctly configured */
if (UART_ENABLE_MS(&uap->port, termios->c_cflag)) {
uap->curregs[R15] |= DCDIE | SYNCIE | CTSIE;
uap->flags |= PMACZILOG_FLAG_MODEM_STATUS;
} else {
uap->curregs[R15] &= ~(DCDIE | SYNCIE | CTSIE);
uap->flags &= ~PMACZILOG_FLAG_MODEM_STATUS;
}
/* Load registers to the chip */
pmz_maybe_update_regs(uap);
}
uart_update_timeout(port, termios->c_cflag, baud);
pmz_debug("pmz: set_termios() done.\n");
}
/*
* Stop Rx side, basically disable emitting of
* Rx interrupts on the port. We don't disable the rx
* side of the chip proper though
* The port lock is held.
*/
static void pmz_stop_rx(struct uart_port *port)
{
struct uart_pmac_port *uap = to_pmz(port);
if (ZS_IS_ASLEEP(uap) || uap->node == NULL)
return;
pmz_debug("pmz: stop_rx()()\n");
/* Disable all RX interrupts. */
uap->curregs[R1] &= ~RxINT_MASK;
pmz_maybe_update_regs(uap);
pmz_debug("pmz: stop_rx() done.\n");
}
/*
* Set Modem Control (RTS & DTR) bits
* The port lock is held and interrupts are disabled.
* Note: Shall we really filter out RTS on external ports or
* should that be dealt at higher level only ?
*/
static void pmz_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
struct uart_pmac_port *uap = to_pmz(port);
unsigned char set_bits, clear_bits;
/* Do nothing for irda for now... */
if (ZS_IS_IRDA(uap))
return;
/* We get called during boot with a port not up yet */
if (ZS_IS_ASLEEP(uap) ||
!(ZS_IS_OPEN(uap) || ZS_IS_CONS(uap)))
return;
set_bits = clear_bits = 0;
if (ZS_IS_INTMODEM(uap)) {
if (mctrl & TIOCM_RTS)
set_bits |= RTS;
else
clear_bits |= RTS;
}
if (mctrl & TIOCM_DTR)
set_bits |= DTR;
else
clear_bits |= DTR;
/* NOTE: Not subject to 'transmitter active' rule. */
uap->curregs[R5] |= set_bits;
uap->curregs[R5] &= ~clear_bits;
if (ZS_IS_ASLEEP(uap))
return;
write_zsreg(uap, R5, uap->curregs[R5]);
pmz_debug("pmz_set_mctrl: set bits: %x, clear bits: %x -> %x\n",
set_bits, clear_bits, uap->curregs[R5]);
zssync(uap);
}
/*
* Enable modem status change interrupts
* The port lock is held.
*/
static void pmz_enable_ms(struct uart_port *port)
{
struct uart_pmac_port *uap = to_pmz(port);
unsigned char new_reg;
if (ZS_IS_IRDA(uap) || uap->node == NULL)
return;
new_reg = uap->curregs[R15] | (DCDIE | SYNCIE | CTSIE);
if (new_reg != uap->curregs[R15]) {
uap->curregs[R15] = new_reg;
if (ZS_IS_ASLEEP(uap))
return;
/* NOTE: Not subject to 'transmitter active' rule. */
write_zsreg(uap, R15, uap->curregs[R15]);
}
}
/*
* Get Modem Control bits (only the input ones, the core will
* or that with a cached value of the control ones)
* The port lock is held and interrupts are disabled.
*/
static unsigned int pmz_get_mctrl(struct uart_port *port)
{
struct uart_pmac_port *uap = to_pmz(port);
unsigned char status;
unsigned int ret;
if (ZS_IS_ASLEEP(uap) || uap->node == NULL)
return 0;
status = read_zsreg(uap, R0);
ret = 0;
if (status & DCD)
ret |= TIOCM_CAR;
if (status & SYNC_HUNT)
ret |= TIOCM_DSR;
if (!(status & CTS))
ret |= TIOCM_CTS;
return ret;
}
/*
* Print a string to the serial port trying not to disturb
* any possible real use of the port...
*/
static void pmz_console_write(struct console *con, const char *s, unsigned int count)
{
struct uart_pmac_port *uap = &pmz_ports[con->index];
unsigned long flags;
if (ZS_IS_ASLEEP(uap))
return;
spin_lock_irqsave(&uap->port.lock, flags);
/* Turn of interrupts and enable the transmitter. */
write_zsreg(uap, R1, uap->curregs[1] & ~TxINT_ENAB);
write_zsreg(uap, R5, uap->curregs[5] | TxENABLE | RTS | DTR);
uart_console_write(&uap->port, s, count, pmz_console_putchar);
/* Restore the values in the registers. */
write_zsreg(uap, R1, uap->curregs[1]);
/* Don't disable the transmitter. */
spin_unlock_irqrestore(&uap->port.lock, flags);
}
/*
* Kick the Tx side.
* The port lock is held and interrupts are disabled.
*/
static void pmz_start_tx(struct uart_port *port)
{
struct uart_pmac_port *uap = to_pmz(port);
unsigned char status;
pmz_debug("pmz: start_tx()\n");
uap->flags |= PMACZILOG_FLAG_TX_ACTIVE;
uap->flags &= ~PMACZILOG_FLAG_TX_STOPPED;
if (ZS_IS_ASLEEP(uap) || uap->node == NULL)
return;
status = read_zsreg(uap, R0);
/* TX busy? Just wait for the TX done interrupt. */
if (!(status & Tx_BUF_EMP))
return;
/* Send the first character to jump-start the TX done
* IRQ sending engine.
*/
if (port->x_char) {
write_zsdata(uap, port->x_char);
zssync(uap);
port->icount.tx++;
port->x_char = 0;
} else {
struct circ_buf *xmit = &port->info->xmit;
write_zsdata(uap, xmit->buf[xmit->tail]);
zssync(uap);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
port->icount.tx++;
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&uap->port);
}
pmz_debug("pmz: start_tx() done.\n");
}
/*
* This is the "normal" startup routine, using the above one
* wrapped with the lock and doing a schedule delay
*/
static int pmz_startup(struct uart_port *port)
{
struct uart_pmac_port *uap = to_pmz(port);
unsigned long flags;
int pwr_delay = 0;
pmz_debug("pmz: startup()\n");
if (ZS_IS_ASLEEP(uap))
return -EAGAIN;
if (uap->node == NULL)
return -ENODEV;
mutex_lock(&pmz_irq_mutex);
uap->flags |= PMACZILOG_FLAG_IS_OPEN;
/* A console is never powered down. Else, power up and
* initialize the chip
*/
if (!ZS_IS_CONS(uap)) {
spin_lock_irqsave(&port->lock, flags);
pwr_delay = __pmz_startup(uap);
spin_unlock_irqrestore(&port->lock, flags);
}
pmz_get_port_A(uap)->flags |= PMACZILOG_FLAG_IS_IRQ_ON;
if (request_irq(uap->port.irq, pmz_interrupt, IRQF_SHARED, "PowerMac Zilog", uap)) {
dev_err(&uap->dev->ofdev.dev,
"Unable to register zs interrupt handler.\n");
pmz_set_scc_power(uap, 0);
mutex_unlock(&pmz_irq_mutex);
return -ENXIO;
}
mutex_unlock(&pmz_irq_mutex);
/* Right now, we deal with delay by blocking here, I'll be
* smarter later on
*/
if (pwr_delay != 0) {
pmz_debug("pmz: delaying %d ms\n", pwr_delay);
msleep(pwr_delay);
}
/* IrDA reset is done now */
if (ZS_IS_IRDA(uap))
pmz_irda_reset(uap);
/* Enable interrupts emission from the chip */
spin_lock_irqsave(&port->lock, flags);
uap->curregs[R1] |= INT_ALL_Rx | TxINT_ENAB;
if (!ZS_IS_EXTCLK(uap))
uap->curregs[R1] |= EXT_INT_ENAB;
write_zsreg(uap, R1, uap->curregs[R1]);
spin_unlock_irqrestore(&port->lock, flags);
pmz_debug("pmz: startup() done.\n");
return 0;
}
static void pmz_transmit_chars(struct uart_pmac_port *uap)
{
struct circ_buf *xmit;
if (ZS_IS_ASLEEP(uap))
return;
if (ZS_IS_CONS(uap)) {
unsigned char status = read_zsreg(uap, R0);
/* TX still busy? Just wait for the next TX done interrupt.
*
* It can occur because of how we do serial console writes. It would
* be nice to transmit console writes just like we normally would for
* a TTY line. (ie. buffered and TX interrupt driven). That is not
* easy because console writes cannot sleep. One solution might be
* to poll on enough port->xmit space becomming free. -DaveM
*/
if (!(status & Tx_BUF_EMP))
return;
}
uap->flags &= ~PMACZILOG_FLAG_TX_ACTIVE;
if (ZS_REGS_HELD(uap)) {
pmz_load_zsregs(uap, uap->curregs);
uap->flags &= ~PMACZILOG_FLAG_REGS_HELD;
}
if (ZS_TX_STOPPED(uap)) {
uap->flags &= ~PMACZILOG_FLAG_TX_STOPPED;
goto ack_tx_int;
}
if (uap->port.x_char) {
uap->flags |= PMACZILOG_FLAG_TX_ACTIVE;
write_zsdata(uap, uap->port.x_char);
zssync(uap);
uap->port.icount.tx++;
uap->port.x_char = 0;
return;
}
if (uap->port.info == NULL)
goto ack_tx_int;
xmit = &uap->port.info->xmit;
if (uart_circ_empty(xmit)) {
uart_write_wakeup(&uap->port);
goto ack_tx_int;
}
if (uart_tx_stopped(&uap->port))
goto ack_tx_int;
uap->flags |= PMACZILOG_FLAG_TX_ACTIVE;
write_zsdata(uap, xmit->buf[xmit->tail]);
zssync(uap);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
uap->port.icount.tx++;
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&uap->port);
return;
ack_tx_int:
write_zsreg(uap, R0, RES_Tx_P);
zssync(uap);
}
/*
* Load all registers to reprogram the port
* This function must only be called when the TX is not busy. The UART
* port lock must be held and local interrupts disabled.
*/
static void pmz_load_zsregs(struct uart_pmac_port *uap, u8 *regs)
{
int i;
if (ZS_IS_ASLEEP(uap))
return;
/* Let pending transmits finish. */
for (i = 0; i < 1000; i++) {
unsigned char stat = read_zsreg(uap, R1);
if (stat & ALL_SNT)
break;
udelay(100);
}
ZS_CLEARERR(uap);
zssync(uap);
ZS_CLEARFIFO(uap);
zssync(uap);
ZS_CLEARERR(uap);
/* Disable all interrupts. */
write_zsreg(uap, R1,
regs[R1] & ~(RxINT_MASK | TxINT_ENAB | EXT_INT_ENAB));
/* Set parity, sync config, stop bits, and clock divisor. */
write_zsreg(uap, R4, regs[R4]);
/* Set misc. TX/RX control bits. */
write_zsreg(uap, R10, regs[R10]);
/* Set TX/RX controls sans the enable bits. */
write_zsreg(uap, R3, regs[R3] & ~RxENABLE);
write_zsreg(uap, R5, regs[R5] & ~TxENABLE);
/* now set R7 "prime" on ESCC */
write_zsreg(uap, R15, regs[R15] | EN85C30);
write_zsreg(uap, R7, regs[R7P]);
/* make sure we use R7 "non-prime" on ESCC */
write_zsreg(uap, R15, regs[R15] & ~EN85C30);
/* Synchronous mode config. */
write_zsreg(uap, R6, regs[R6]);
write_zsreg(uap, R7, regs[R7]);
/* Disable baud generator. */
write_zsreg(uap, R14, regs[R14] & ~BRENAB);
/* Clock mode control. */
write_zsreg(uap, R11, regs[R11]);
/* Lower and upper byte of baud rate generator divisor. */
write_zsreg(uap, R12, regs[R12]);
write_zsreg(uap, R13, regs[R13]);
/* Now rewrite R14, with BRENAB (if set). */
write_zsreg(uap, R14, regs[R14]);
/* Reset external status interrupts. */
write_zsreg(uap, R0, RES_EXT_INT);
write_zsreg(uap, R0, RES_EXT_INT);
/* Rewrite R3/R5, this time without enables masked. */
write_zsreg(uap, R3, regs[R3]);
write_zsreg(uap, R5, regs[R5]);
/* Rewrite R1, this time without IRQ enabled masked. */
write_zsreg(uap, R1, regs[R1]);
/* Enable interrupts */
write_zsreg(uap, R9, regs[R9]);
}
static struct tty_struct *pmz_receive_chars(struct uart_pmac_port *uap,
struct pt_regs *regs)
{
struct tty_struct *tty = NULL;
unsigned char ch, r1, drop, error;
int loops = 0;
retry:
/* The interrupt can be enabled when the port isn't open, typically
* that happens when using one port is open and the other closed (stale
* interrupt) or when one port is used as a console.
*/
if (!ZS_IS_OPEN(uap)) {
pmz_debug("pmz: draining input\n");
/* Port is closed, drain input data */
for (;;) {
if ((++loops) > 1000)
goto flood;
(void)read_zsreg(uap, R1);
write_zsreg(uap, R0, ERR_RES);
(void)read_zsdata(uap);
ch = read_zsreg(uap, R0);
if (!(ch & Rx_CH_AV))
break;
}
return NULL;
}
/* Sanity check, make sure the old bug is no longer happening */
if (uap->port.info == NULL || uap->port.info->tty == NULL) {
WARN_ON(1);
(void)read_zsdata(uap);
return NULL;
}
tty = uap->port.info->tty;
while (1) {
error = 0;
drop = 0;
if (unlikely(tty->flip.count >= TTY_FLIPBUF_SIZE)) {
/* Have to drop the lock here */
pmz_debug("pmz: flip overflow\n");
spin_unlock(&uap->port.lock);
tty->flip.work.func((void *)tty);
spin_lock(&uap->port.lock);
if (tty->flip.count >= TTY_FLIPBUF_SIZE)
drop = 1;
if (ZS_IS_ASLEEP(uap))
return NULL;
if (!ZS_IS_OPEN(uap))
goto retry;
}
r1 = read_zsreg(uap, R1);
ch = read_zsdata(uap);
if (r1 & (PAR_ERR | Rx_OVR | CRC_ERR)) {
write_zsreg(uap, R0, ERR_RES);
zssync(uap);
}
ch &= uap->parity_mask;
if (ch == 0 && uap->prev_status & BRK_ABRT)
r1 |= BRK_ABRT;
/* A real serial line, record the character and status. */
if (drop)
goto next_char;
*tty->flip.char_buf_ptr = ch;
*tty->flip.flag_buf_ptr = TTY_NORMAL;
uap->port.icount.rx++;
if (r1 & (PAR_ERR | Rx_OVR | CRC_ERR | BRK_ABRT)) {
error = 1;
if (r1 & BRK_ABRT) {
pmz_debug("pmz: got break !\n");
r1 &= ~(PAR_ERR | CRC_ERR);
uap->port.icount.brk++;
if (uart_handle_break(&uap->port)) {
pmz_debug("pmz: do handle break !\n");
goto next_char;
}
}
else if (r1 & PAR_ERR)
uap->port.icount.parity++;
else if (r1 & CRC_ERR)
uap->port.icount.frame++;
if (r1 & Rx_OVR)
uap->port.icount.overrun++;
r1 &= uap->port.read_status_mask;
if (r1 & BRK_ABRT)
*tty->flip.flag_buf_ptr = TTY_BREAK;
else if (r1 & PAR_ERR)
*tty->flip.flag_buf_ptr = TTY_PARITY;
else if (r1 & CRC_ERR)
*tty->flip.flag_buf_ptr = TTY_FRAME;
}
if (uart_handle_sysrq_char(&uap->port, ch, regs)) {
pmz_debug("pmz: sysrq swallowed the char\n");
goto next_char;
}
if (uap->port.ignore_status_mask == 0xff ||
(r1 & uap->port.ignore_status_mask) == 0) {
tty->flip.flag_buf_ptr++;
tty->flip.char_buf_ptr++;
tty->flip.count++;
}
if ((r1 & Rx_OVR) &&
tty->flip.count < TTY_FLIPBUF_SIZE) {
*tty->flip.flag_buf_ptr = TTY_OVERRUN;
tty->flip.flag_buf_ptr++;
tty->flip.char_buf_ptr++;
tty->flip.count++;
}
next_char:
/* We can get stuck in an infinite loop getting char 0 when the
* line is in a wrong HW state, we break that here.
* When that happens, I disable the receive side of the driver.
* Note that what I've been experiencing is a real irq loop where
* I'm getting flooded regardless of the actual port speed.
* Something stange is going on with the HW
*/
if ((++loops) > 1000)
goto flood;
ch = read_zsreg(uap, R0);
if (!(ch & Rx_CH_AV))
break;
}
return tty;
flood:
uap->curregs[R1] &= ~(EXT_INT_ENAB | TxINT_ENAB | RxINT_MASK);
write_zsreg(uap, R1, uap->curregs[R1]);
zssync(uap);
dev_err(&uap->dev->ofdev.dev, "pmz: rx irq flood !\n");
return tty;
}