/*
* This is the serial driver's interrupt routine.
*
* Arjan thinks the old way was overly complex, so it got simplified.
* Alan disagrees, saying that need the complexity to handle the weird
* nature of ISA shared interrupts. (This is a special exception.)
*
* In order to handle ISA shared interrupts properly, we need to check
* that all ports have been serviced, and therefore the ISA interrupt
* line has been de-asserted.
*
* This means we need to loop through all ports. checking that they
* don't have an interrupt pending.
*/
static irqreturn_t m32r_sio_interrupt(int irq, void *dev_id)
{
struct irq_info *i = dev_id;
struct list_head *l, *end = NULL;
int pass_counter = 0;
DEBUG_INTR("m32r_sio_interrupt(%d)...", irq);
#ifdef CONFIG_SERIAL_M32R_PLDSIO
// if (irq == PLD_IRQ_SIO0_SND)
// irq = PLD_IRQ_SIO0_RCV;
#else
if (irq == M32R_IRQ_SIO0_S)
irq = M32R_IRQ_SIO0_R;
#endif
spin_lock(&i->lock);
l = i->head;
do {
struct uart_sio_port *up;
unsigned int sts;
up = list_entry(l, struct uart_sio_port, list);
sts = sio_in(up, SIOSTS);
if (sts & 0x5) {
spin_lock(&up->port.lock);
m32r_sio_handle_port(up, sts);
spin_unlock(&up->port.lock);
end = NULL;
} else if (end == NULL)
end = l;
l = l->next;
if (l == i->head && pass_counter++ > PASS_LIMIT) {
if (sts & 0xe0)
sio_error(&sts);
break;
}
} while (l != end);
spin_unlock(&i->lock);
DEBUG_INTR("end.\n");
return IRQ_HANDLED;
}
static _INLINE_ void transmit_chars(struct uart_8250_port *up)
{
struct circ_buf *xmit = &up->port.info->xmit;
int count;
if (up->port.x_char) {
serial_outp(up, UART_TX, up->port.x_char);
up->port.icount.tx++;
up->port.x_char = 0;
return;
}
if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
serial8250_stop_tx(&up->port);
return;
}
count = up->port.fifosize;
do {
serial_out(up, UART_TX, xmit->buf[xmit->tail]);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
up->port.icount.tx++;
if (uart_circ_empty(xmit))
break;
} while (--count > 0);
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&up->port);
DEBUG_INTR("THRE...");
if (uart_circ_empty(xmit))
serial8250_stop_tx(&up->port);
}
/*
* This is the serial driver's interrupt routine.
*
* Arjan thinks the old way was overly complex, so it got simplified.
* Alan disagrees, saying that need the complexity to handle the weird
* nature of ISA shared interrupts. (This is a special exception.)
*
* In order to handle ISA shared interrupts properly, we need to check
* that all ports have been serviced, and therefore the ISA interrupt
* line has been de-asserted.
*
* This means we need to loop through all ports. checking that they
* don't have an interrupt pending.
*/
static irqreturn_t serial8250_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
struct irq_info *i = dev_id;
struct list_head *l, *end = NULL;
int pass_counter = 0;
DEBUG_INTR("serial8250_interrupt(%d)...", irq);
spin_lock(&i->lock);
l = i->head;
do {
struct uart_8250_port *up;
unsigned int iir;
up = list_entry(l, struct uart_8250_port, list);
iir = serial_in(up, UART_IIR);
if (!(iir & UART_IIR_NO_INT)) {
spin_lock(&up->port.lock);
serial8250_handle_port(up, regs);
spin_unlock(&up->port.lock);
end = NULL;
} else if (end == NULL)
end = l;
l = l->next;
if (l == i->head && pass_counter++ > PASS_LIMIT) {
/* If we hit this, we're dead. */
printk(KERN_ERR "serial8250: too much work for "
"irq%d\n", irq);
break;
}
} while (l != end);
spin_unlock(&i->lock);
DEBUG_INTR("end.\n");
/* FIXME! Was it really ours? */
return IRQ_HANDLED;
}
/*
* This handles the interrupt from one port.
*/
static inline void m32r_sio_handle_port(struct uart_sio_port *up,
unsigned int status)
{
DEBUG_INTR("status = %x...", status);
if (status & 0x04)
receive_chars(up, &status);
if (status & 0x01)
transmit_chars(up);
}
/*
* This handles the interrupt from one port.
*/
static inline void
serial8250_handle_port(struct uart_8250_port *up, struct pt_regs *regs)
{
unsigned int status = serial_inp(up, UART_LSR);
DEBUG_INTR("status = %x...", status);
if (status & UART_LSR_DR)
receive_chars(up, &status, regs);
check_modem_status(up);
if (status & UART_LSR_THRE)
transmit_chars(up);
}
static void transmit_chars(struct uart_sio_port *up)
{
struct circ_buf *xmit = &up->port.state->xmit;
int count;
if (up->port.x_char) {
#ifndef CONFIG_SERIAL_M32R_PLDSIO /* XXX */
serial_out(up, UART_TX, up->port.x_char);
#endif
up->port.icount.tx++;
up->port.x_char = 0;
return;
}
if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
m32r_sio_stop_tx(&up->port);
return;
}
count = up->port.fifosize;
do {
serial_out(up, UART_TX, xmit->buf[xmit->tail]);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
up->port.icount.tx++;
if (uart_circ_empty(xmit))
break;
while (!(serial_in(up, UART_LSR) & UART_LSR_THRE));
} while (--count > 0);
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&up->port);
DEBUG_INTR("THRE...");
if (uart_circ_empty(xmit))
m32r_sio_stop_tx(&up->port);
}
static _INLINE_ void
receive_chars(struct uart_8250_port *up, int *status, struct pt_regs *regs)
{
struct tty_struct *tty = up->port.info->tty;
unsigned char ch;
int max_count = 256;
do {
if (unlikely(tty->flip.count >= TTY_FLIPBUF_SIZE)) {
tty->flip.work.func((void *)tty);
if (tty->flip.count >= TTY_FLIPBUF_SIZE)
return; // if TTY_DONT_FLIP is set
}
ch = serial_inp(up, UART_RX);
*tty->flip.char_buf_ptr = ch;
*tty->flip.flag_buf_ptr = TTY_NORMAL;
up->port.icount.rx++;
if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
UART_LSR_FE | UART_LSR_OE))) {
/*
* For statistics only
*/
if (*status & UART_LSR_BI) {
*status &= ~(UART_LSR_FE | UART_LSR_PE);
up->port.icount.brk++;
/*
* We do the SysRQ and SAK checking
* here because otherwise the break
* may get masked by ignore_status_mask
* or read_status_mask.
*/
if (uart_handle_break(&up->port))
goto ignore_char;
} else if (*status & UART_LSR_PE)
up->port.icount.parity++;
else if (*status & UART_LSR_FE)
up->port.icount.frame++;
if (*status & UART_LSR_OE)
up->port.icount.overrun++;
/*
* Mask off conditions which should be ingored.
*/
*status &= up->port.read_status_mask;
#ifdef CONFIG_SERIAL_AU1X00_CONSOLE
if (up->port.line == up->port.cons->index) {
/* Recover the break flag from console xmit */
*status |= up->lsr_break_flag;
up->lsr_break_flag = 0;
}
#endif
if (*status & UART_LSR_BI) {
DEBUG_INTR("handling break....");
*tty->flip.flag_buf_ptr = TTY_BREAK;
} else if (*status & UART_LSR_PE)
*tty->flip.flag_buf_ptr = TTY_PARITY;
else if (*status & UART_LSR_FE)
*tty->flip.flag_buf_ptr = TTY_FRAME;
}
if (uart_handle_sysrq_char(&up->port, ch, regs))
goto ignore_char;
if ((*status & up->port.ignore_status_mask) == 0) {
tty->flip.flag_buf_ptr++;
tty->flip.char_buf_ptr++;
tty->flip.count++;
}
if ((*status & UART_LSR_OE) &&
tty->flip.count < TTY_FLIPBUF_SIZE) {
/*
* Overrun is special, since it's reported
* immediately, and doesn't affect the current
* character.
*/
*tty->flip.flag_buf_ptr = TTY_OVERRUN;
tty->flip.flag_buf_ptr++;
tty->flip.char_buf_ptr++;
tty->flip.count++;
}
ignore_char:
*status = serial_inp(up, UART_LSR);
} while ((*status & UART_LSR_DR) && (max_count-- > 0));
spin_unlock(&up->port.lock);
tty_flip_buffer_push(tty);
spin_lock(&up->port.lock);
}
static void receive_chars(struct uart_sio_port *up, int *status)
{
struct tty_port *port = &up->port.state->port;
unsigned char ch;
unsigned char flag;
int max_count = 256;
do {
ch = sio_in(up, SIORXB);
flag = TTY_NORMAL;
up->port.icount.rx++;
if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
UART_LSR_FE | UART_LSR_OE))) {
/*
* For statistics only
*/
if (*status & UART_LSR_BI) {
*status &= ~(UART_LSR_FE | UART_LSR_PE);
up->port.icount.brk++;
/*
* We do the SysRQ and SAK checking
* here because otherwise the break
* may get masked by ignore_status_mask
* or read_status_mask.
*/
if (uart_handle_break(&up->port))
goto ignore_char;
} else if (*status & UART_LSR_PE)
up->port.icount.parity++;
else if (*status & UART_LSR_FE)
up->port.icount.frame++;
if (*status & UART_LSR_OE)
up->port.icount.overrun++;
/*
* Mask off conditions which should be ingored.
*/
*status &= up->port.read_status_mask;
if (up->port.line == up->port.cons->index) {
/* Recover the break flag from console xmit */
*status |= up->lsr_break_flag;
up->lsr_break_flag = 0;
}
if (*status & UART_LSR_BI) {
DEBUG_INTR("handling break....");
flag = TTY_BREAK;
} else if (*status & UART_LSR_PE)
flag = TTY_PARITY;
else if (*status & UART_LSR_FE)
flag = TTY_FRAME;
}
if (uart_handle_sysrq_char(&up->port, ch))
goto ignore_char;
if ((*status & up->port.ignore_status_mask) == 0)
tty_insert_flip_char(port, ch, flag);
if (*status & UART_LSR_OE) {
/*
* Overrun is special, since it's reported
* immediately, and doesn't affect the current
* character.
*/
tty_insert_flip_char(port, 0, TTY_OVERRUN);
}
ignore_char:
*status = serial_in(up, UART_LSR);
} while ((*status & UART_LSR_DR) && (max_count-- > 0));
spin_unlock(&up->port.lock);
tty_flip_buffer_push(port);
spin_lock(&up->port.lock);
}
