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linux/drivers/serial/sunsab.c
David S. Miller b8df110fea [SPARC64]: Fix oops on runlevel change with serial console. 
Incorrect uart_write_wakeup() calls cause reference to a
NULL tty pointer in sunsab and sunzilog serial drivers.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-10 20:43:22 -07:00

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/* sunsab.c: ASYNC Driver for the SIEMENS SAB82532 DUSCC.
*
* Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
* Copyright (C) 2002 David S. Miller (davem@redhat.com)
*
* Rewrote buffer handling to use CIRC(Circular Buffer) macros.
* Maxim Krasnyanskiy <maxk@qualcomm.com>
*
* Fixed to use tty_get_baud_rate, and to allow for arbitrary baud
* rates to be programmed into the UART. Also eliminated a lot of
* duplicated code in the console setup.
* Theodore Ts'o <tytso@mit.edu>, 2001-Oct-12
*
* Ported to new 2.5.x UART layer.
* David S. Miller <davem@redhat.com>
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/circ_buf.h>
#include <linux/serial.h>
#include <linux/sysrq.h>
#include <linux/console.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/oplib.h>
#include <asm/ebus.h>
#if defined(CONFIG_SERIAL_SUNZILOG_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#include <linux/serial_core.h>
#include "suncore.h"
#include "sunsab.h"
struct uart_sunsab_port {
struct uart_port port; /* Generic UART port */
union sab82532_async_regs __iomem *regs; /* Chip registers */
unsigned long irqflags; /* IRQ state flags */
int dsr; /* Current DSR state */
unsigned int cec_timeout; /* Chip poll timeout... */
unsigned int tec_timeout; /* likewise */
unsigned char interrupt_mask0;/* ISR0 masking */
unsigned char interrupt_mask1;/* ISR1 masking */
unsigned char pvr_dtr_bit; /* Which PVR bit is DTR */
unsigned char pvr_dsr_bit; /* Which PVR bit is DSR */
int type; /* SAB82532 version */
/* Setting configuration bits while the transmitter is active
* can cause garbage characters to get emitted by the chip.
* Therefore, we cache such writes here and do the real register
* write the next time the transmitter becomes idle.
*/
unsigned int cached_ebrg;
unsigned char cached_mode;
unsigned char cached_pvr;
unsigned char cached_dafo;
};
/*
* This assumes you have a 29.4912 MHz clock for your UART.
*/
#define SAB_BASE_BAUD ( 29491200 / 16 )
static char *sab82532_version[16] = {
"V1.0", "V2.0", "V3.2", "V(0x03)",
"V(0x04)", "V(0x05)", "V(0x06)", "V(0x07)",
"V(0x08)", "V(0x09)", "V(0x0a)", "V(0x0b)",
"V(0x0c)", "V(0x0d)", "V(0x0e)", "V(0x0f)"
};
#define SAB82532_MAX_TEC_TIMEOUT 200000 /* 1 character time (at 50 baud) */
#define SAB82532_MAX_CEC_TIMEOUT 50000 /* 2.5 TX CLKs (at 50 baud) */
#define SAB82532_RECV_FIFO_SIZE 32 /* Standard async fifo sizes */
#define SAB82532_XMIT_FIFO_SIZE 32
static __inline__ void sunsab_tec_wait(struct uart_sunsab_port *up)
{
int timeout = up->tec_timeout;
while ((readb(&up->regs->r.star) & SAB82532_STAR_TEC) && --timeout)
udelay(1);
}
static __inline__ void sunsab_cec_wait(struct uart_sunsab_port *up)
{
int timeout = up->cec_timeout;
while ((readb(&up->regs->r.star) & SAB82532_STAR_CEC) && --timeout)
udelay(1);
}
static struct tty_struct *
receive_chars(struct uart_sunsab_port *up,
union sab82532_irq_status *stat,
struct pt_regs *regs)
{
struct tty_struct *tty = NULL;
unsigned char buf[32];
int saw_console_brk = 0;
int free_fifo = 0;
int count = 0;
int i;
if (up->port.info != NULL) /* Unopened serial console */
tty = up->port.info->tty;
/* Read number of BYTES (Character + Status) available. */
if (stat->sreg.isr0 & SAB82532_ISR0_RPF) {
count = SAB82532_RECV_FIFO_SIZE;
free_fifo++;
}
if (stat->sreg.isr0 & SAB82532_ISR0_TCD) {
count = readb(&up->regs->r.rbcl) & (SAB82532_RECV_FIFO_SIZE - 1);
free_fifo++;
}
/* Issue a FIFO read command in case we where idle. */
if (stat->sreg.isr0 & SAB82532_ISR0_TIME) {
sunsab_cec_wait(up);
writeb(SAB82532_CMDR_RFRD, &up->regs->w.cmdr);
return tty;
}
if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
free_fifo++;
/* Read the FIFO. */
for (i = 0; i < count; i++)
buf[i] = readb(&up->regs->r.rfifo[i]);
/* Issue Receive Message Complete command. */
if (free_fifo) {
sunsab_cec_wait(up);
writeb(SAB82532_CMDR_RMC, &up->regs->w.cmdr);
}
/* Count may be zero for BRK, so we check for it here */
if ((stat->sreg.isr1 & SAB82532_ISR1_BRK) &&
(up->port.line == up->port.cons->index))
saw_console_brk = 1;
for (i = 0; i < count; i++) {
unsigned char ch = buf[i];
if (tty == NULL) {
uart_handle_sysrq_char(&up->port, ch, regs);
continue;
}
if (unlikely(tty->flip.count >= TTY_FLIPBUF_SIZE)) {
tty->flip.work.func((void *)tty);
if (tty->flip.count >= TTY_FLIPBUF_SIZE)
return tty; // if TTY_DONT_FLIP is set
}
*tty->flip.char_buf_ptr = ch;
*tty->flip.flag_buf_ptr = TTY_NORMAL;
up->port.icount.rx++;
if (unlikely(stat->sreg.isr0 & (SAB82532_ISR0_PERR |
SAB82532_ISR0_FERR |
SAB82532_ISR0_RFO)) ||
unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) {
/*
* For statistics only
*/
if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR |
SAB82532_ISR0_FERR);
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))
continue;
} else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
up->port.icount.parity++;
else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
up->port.icount.frame++;
if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
up->port.icount.overrun++;
/*
* Mask off conditions which should be ingored.
*/
stat->sreg.isr0 &= (up->port.read_status_mask & 0xff);
stat->sreg.isr1 &= ((up->port.read_status_mask >> 8) & 0xff);
if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
*tty->flip.flag_buf_ptr = TTY_BREAK;
} else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
*tty->flip.flag_buf_ptr = TTY_PARITY;
else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
*tty->flip.flag_buf_ptr = TTY_FRAME;
}
if (uart_handle_sysrq_char(&up->port, ch, regs))
continue;
if ((stat->sreg.isr0 & (up->port.ignore_status_mask & 0xff)) == 0 &&
(stat->sreg.isr1 & ((up->port.ignore_status_mask >> 8) & 0xff)) == 0){
tty->flip.flag_buf_ptr++;
tty->flip.char_buf_ptr++;
tty->flip.count++;
}
if ((stat->sreg.isr0 & SAB82532_ISR0_RFO) &&
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++;
}
}
if (saw_console_brk)
sun_do_break();
return tty;
}
static void sunsab_stop_tx(struct uart_port *);
static void sunsab_tx_idle(struct uart_sunsab_port *);
static void transmit_chars(struct uart_sunsab_port *up,
union sab82532_irq_status *stat)
{
struct circ_buf *xmit = &up->port.info->xmit;
int i;
if (stat->sreg.isr1 & SAB82532_ISR1_ALLS) {
up->interrupt_mask1 |= SAB82532_IMR1_ALLS;
writeb(up->interrupt_mask1, &up->regs->w.imr1);
set_bit(SAB82532_ALLS, &up->irqflags);
}
#if 0 /* bde@nwlink.com says this check causes problems */
if (!(stat->sreg.isr1 & SAB82532_ISR1_XPR))
return;
#endif
if (!(readb(&up->regs->r.star) & SAB82532_STAR_XFW))
return;
set_bit(SAB82532_XPR, &up->irqflags);
sunsab_tx_idle(up);
if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
up->interrupt_mask1 |= SAB82532_IMR1_XPR;
writeb(up->interrupt_mask1, &up->regs->w.imr1);
return;
}
up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
writeb(up->interrupt_mask1, &up->regs->w.imr1);
clear_bit(SAB82532_ALLS, &up->irqflags);
/* Stuff 32 bytes into Transmit FIFO. */
clear_bit(SAB82532_XPR, &up->irqflags);
for (i = 0; i < up->port.fifosize; i++) {
writeb(xmit->buf[xmit->tail],
&up->regs->w.xfifo[i]);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
up->port.icount.tx++;
if (uart_circ_empty(xmit))
break;
}
/* Issue a Transmit Frame command. */
sunsab_cec_wait(up);
writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&up->port);
if (uart_circ_empty(xmit))
sunsab_stop_tx(&up->port);
}
static void check_status(struct uart_sunsab_port *up,
union sab82532_irq_status *stat)
{
if (stat->sreg.isr0 & SAB82532_ISR0_CDSC)
uart_handle_dcd_change(&up->port,
!(readb(&up->regs->r.vstr) & SAB82532_VSTR_CD));
if (stat->sreg.isr1 & SAB82532_ISR1_CSC)
uart_handle_cts_change(&up->port,
(readb(&up->regs->r.star) & SAB82532_STAR_CTS));
if ((readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ^ up->dsr) {
up->dsr = (readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ? 0 : 1;
up->port.icount.dsr++;
}
wake_up_interruptible(&up->port.info->delta_msr_wait);
}
static irqreturn_t sunsab_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
struct uart_sunsab_port *up = dev_id;
struct tty_struct *tty;
union sab82532_irq_status status;
unsigned long flags;
spin_lock_irqsave(&up->port.lock, flags);
status.stat = 0;
if (readb(&up->regs->r.gis) & SAB82532_GIS_ISA0)
status.sreg.isr0 = readb(&up->regs->r.isr0);
if (readb(&up->regs->r.gis) & SAB82532_GIS_ISA1)
status.sreg.isr1 = readb(&up->regs->r.isr1);
tty = NULL;
if (status.stat) {
if ((status.sreg.isr0 & (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
SAB82532_ISR0_RFO | SAB82532_ISR0_RPF)) ||
(status.sreg.isr1 & SAB82532_ISR1_BRK))
tty = receive_chars(up, &status, regs);
if ((status.sreg.isr0 & SAB82532_ISR0_CDSC) ||
(status.sreg.isr1 & SAB82532_ISR1_CSC))
check_status(up, &status);
if (status.sreg.isr1 & (SAB82532_ISR1_ALLS | SAB82532_ISR1_XPR))
transmit_chars(up, &status);
}
spin_unlock(&up->port.lock);
if (tty)
tty_flip_buffer_push(tty);
up++;
spin_lock(&up->port.lock);
status.stat = 0;
if (readb(&up->regs->r.gis) & SAB82532_GIS_ISB0)
status.sreg.isr0 = readb(&up->regs->r.isr0);
if (readb(&up->regs->r.gis) & SAB82532_GIS_ISB1)
status.sreg.isr1 = readb(&up->regs->r.isr1);
tty = NULL;
if (status.stat) {
if ((status.sreg.isr0 & (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
SAB82532_ISR0_RFO | SAB82532_ISR0_RPF)) ||
(status.sreg.isr1 & SAB82532_ISR1_BRK))
tty = receive_chars(up, &status, regs);
if ((status.sreg.isr0 & SAB82532_ISR0_CDSC) ||
(status.sreg.isr1 & (SAB82532_ISR1_BRK | SAB82532_ISR1_CSC)))
check_status(up, &status);
if (status.sreg.isr1 & (SAB82532_ISR1_ALLS | SAB82532_ISR1_XPR))
transmit_chars(up, &status);
}
spin_unlock_irqrestore(&up->port.lock, flags);
if (tty)
tty_flip_buffer_push(tty);
return IRQ_HANDLED;
}
/* port->lock is not held. */
static unsigned int sunsab_tx_empty(struct uart_port *port)
{
struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
int ret;
/* Do not need a lock for a state test like this. */
if (test_bit(SAB82532_ALLS, &up->irqflags))
ret = TIOCSER_TEMT;
else
ret = 0;
return ret;
}
/* port->lock held by caller. */
static void sunsab_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
if (mctrl & TIOCM_RTS) {
up->cached_mode &= ~SAB82532_MODE_FRTS;
up->cached_mode |= SAB82532_MODE_RTS;
} else {
up->cached_mode |= (SAB82532_MODE_FRTS |
SAB82532_MODE_RTS);
}
if (mctrl & TIOCM_DTR) {
up->cached_pvr &= ~(up->pvr_dtr_bit);
} else {
up->cached_pvr |= up->pvr_dtr_bit;
}
set_bit(SAB82532_REGS_PENDING, &up->irqflags);
if (test_bit(SAB82532_XPR, &up->irqflags))
sunsab_tx_idle(up);
}
/* port->lock is held by caller and interrupts are disabled. */
static unsigned int sunsab_get_mctrl(struct uart_port *port)
{
struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
unsigned char val;
unsigned int result;
result = 0;
val = readb(&up->regs->r.pvr);
result |= (val & up->pvr_dsr_bit) ? 0 : TIOCM_DSR;
val = readb(&up->regs->r.vstr);
result |= (val & SAB82532_VSTR_CD) ? 0 : TIOCM_CAR;
val = readb(&up->regs->r.star);
result |= (val & SAB82532_STAR_CTS) ? TIOCM_CTS : 0;
return result;
}
/* port->lock held by caller. */
static void sunsab_stop_tx(struct uart_port *port)
{
struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
up->interrupt_mask1 |= SAB82532_IMR1_XPR;
writeb(up->interrupt_mask1, &up->regs->w.imr1);
}
/* port->lock held by caller. */
static void sunsab_tx_idle(struct uart_sunsab_port *up)
{
if (test_bit(SAB82532_REGS_PENDING, &up->irqflags)) {
u8 tmp;
clear_bit(SAB82532_REGS_PENDING, &up->irqflags);
writeb(up->cached_mode, &up->regs->rw.mode);
writeb(up->cached_pvr, &up->regs->rw.pvr);
writeb(up->cached_dafo, &up->regs->w.dafo);
writeb(up->cached_ebrg & 0xff, &up->regs->w.bgr);
tmp = readb(&up->regs->rw.ccr2);
tmp &= ~0xc0;
tmp |= (up->cached_ebrg >> 2) & 0xc0;
writeb(tmp, &up->regs->rw.ccr2);
}
}
/* port->lock held by caller. */
static void sunsab_start_tx(struct uart_port *port)
{
struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
struct circ_buf *xmit = &up->port.info->xmit;
int i;
up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
writeb(up->interrupt_mask1, &up->regs->w.imr1);
if (!test_bit(SAB82532_XPR, &up->irqflags))
return;
clear_bit(SAB82532_ALLS, &up->irqflags);
clear_bit(SAB82532_XPR, &up->irqflags);
for (i = 0; i < up->port.fifosize; i++) {
writeb(xmit->buf[xmit->tail],
&up->regs->w.xfifo[i]);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
up->port.icount.tx++;
if (uart_circ_empty(xmit))
break;
}
/* Issue a Transmit Frame command. */
sunsab_cec_wait(up);
writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
}
/* port->lock is not held. */
static void sunsab_send_xchar(struct uart_port *port, char ch)
{
struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
unsigned long flags;
spin_lock_irqsave(&up->port.lock, flags);
sunsab_tec_wait(up);
writeb(ch, &up->regs->w.tic);
spin_unlock_irqrestore(&up->port.lock, flags);
}
/* port->lock held by caller. */
static void sunsab_stop_rx(struct uart_port *port)
{
struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
up->interrupt_mask0 |= SAB82532_ISR0_TCD;
writeb(up->interrupt_mask1, &up->regs->w.imr0);
}
/* port->lock held by caller. */
static void sunsab_enable_ms(struct uart_port *port)
{
/* For now we always receive these interrupts. */
}
/* port->lock is not held. */
static void sunsab_break_ctl(struct uart_port *port, int break_state)
{
struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
unsigned long flags;
unsigned char val;
spin_lock_irqsave(&up->port.lock, flags);
val = up->cached_dafo;
if (break_state)
val |= SAB82532_DAFO_XBRK;
else
val &= ~SAB82532_DAFO_XBRK;
up->cached_dafo = val;
set_bit(SAB82532_REGS_PENDING, &up->irqflags);
if (test_bit(SAB82532_XPR, &up->irqflags))
sunsab_tx_idle(up);
spin_unlock_irqrestore(&up->port.lock, flags);
}
/* port->lock is not held. */
static int sunsab_startup(struct uart_port *port)
{
struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
unsigned long flags;
unsigned char tmp;
spin_lock_irqsave(&up->port.lock, flags);
/*
* Wait for any commands or immediate characters
*/
sunsab_cec_wait(up);
sunsab_tec_wait(up);
/*
* Clear the FIFO buffers.
*/
writeb(SAB82532_CMDR_RRES, &up->regs->w.cmdr);
sunsab_cec_wait(up);
writeb(SAB82532_CMDR_XRES, &up->regs->w.cmdr);
/*
* Clear the interrupt registers.
*/
(void) readb(&up->regs->r.isr0);
(void) readb(&up->regs->r.isr1);
/*
* Now, initialize the UART
*/
writeb(0, &up->regs->w.ccr0); /* power-down */
writeb(SAB82532_CCR0_MCE | SAB82532_CCR0_SC_NRZ |
SAB82532_CCR0_SM_ASYNC, &up->regs->w.ccr0);
writeb(SAB82532_CCR1_ODS | SAB82532_CCR1_BCR | 7, &up->regs->w.ccr1);
writeb(SAB82532_CCR2_BDF | SAB82532_CCR2_SSEL |
SAB82532_CCR2_TOE, &up->regs->w.ccr2);
writeb(0, &up->regs->w.ccr3);
writeb(SAB82532_CCR4_MCK4 | SAB82532_CCR4_EBRG, &up->regs->w.ccr4);
up->cached_mode = (SAB82532_MODE_RTS | SAB82532_MODE_FCTS |
SAB82532_MODE_RAC);
writeb(up->cached_mode, &up->regs->w.mode);
writeb(SAB82532_RFC_DPS|SAB82532_RFC_RFTH_32, &up->regs->w.rfc);
tmp = readb(&up->regs->rw.ccr0);
tmp |= SAB82532_CCR0_PU; /* power-up */
writeb(tmp, &up->regs->rw.ccr0);
/*
* Finally, enable interrupts
*/
up->interrupt_mask0 = (SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
SAB82532_IMR0_PLLA);
writeb(up->interrupt_mask0, &up->regs->w.imr0);
up->interrupt_mask1 = (SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
SAB82532_IMR1_XPR);
writeb(up->interrupt_mask1, &up->regs->w.imr1);
set_bit(SAB82532_ALLS, &up->irqflags);
set_bit(SAB82532_XPR, &up->irqflags);
spin_unlock_irqrestore(&up->port.lock, flags);
return 0;
}
/* port->lock is not held. */
static void sunsab_shutdown(struct uart_port *port)
{
struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
unsigned long flags;
spin_lock_irqsave(&up->port.lock, flags);
/* Disable Interrupts */
up->interrupt_mask0 = 0xff;
writeb(up->interrupt_mask0, &up->regs->w.imr0);
up->interrupt_mask1 = 0xff;
writeb(up->interrupt_mask1, &up->regs->w.imr1);
/* Disable break condition */
up->cached_dafo = readb(&up->regs->rw.dafo);
up->cached_dafo &= ~SAB82532_DAFO_XBRK;
writeb(up->cached_dafo, &up->regs->rw.dafo);
/* Disable Receiver */
up->cached_mode &= ~SAB82532_MODE_RAC;
writeb(up->cached_mode, &up->regs->rw.mode);
/*
* XXX FIXME
*
* If the chip is powered down here the system hangs/crashes during
* reboot or shutdown. This needs to be investigated further,
* similar behaviour occurs in 2.4 when the driver is configured
* as a module only. One hint may be that data is sometimes
* transmitted at 9600 baud during shutdown (regardless of the
* speed the chip was configured for when the port was open).
*/
#if 0
/* Power Down */
tmp = readb(&up->regs->rw.ccr0);
tmp &= ~SAB82532_CCR0_PU;
writeb(tmp, &up->regs->rw.ccr0);
#endif
spin_unlock_irqrestore(&up->port.lock, flags);
}
/*
* This is used to figure out the divisor speeds.
*
* The formula is: Baud = SAB_BASE_BAUD / ((N + 1) * (1 << M)),
*
* with 0 <= N < 64 and 0 <= M < 16
*/
static void calc_ebrg(int baud, int *n_ret, int *m_ret)
{
int n, m;
if (baud == 0) {
*n_ret = 0;
*m_ret = 0;
return;
}
/*
* We scale numbers by 10 so that we get better accuracy
* without having to use floating point. Here we increment m
* until n is within the valid range.
*/
n = (SAB_BASE_BAUD * 10) / baud;
m = 0;
while (n >= 640) {
n = n / 2;
m++;
}
n = (n+5) / 10;
/*
* We try very hard to avoid speeds with M == 0 since they may
* not work correctly for XTAL frequences above 10 MHz.
*/
if ((m == 0) && ((n & 1) == 0)) {
n = n / 2;
m++;
}
*n_ret = n - 1;
*m_ret = m;
}
/* Internal routine, port->lock is held and local interrupts are disabled. */
static void sunsab_convert_to_sab(struct uart_sunsab_port *up, unsigned int cflag,
unsigned int iflag, unsigned int baud,
unsigned int quot)
{
unsigned char dafo;
int bits, n, m;
/* Byte size and parity */
switch (cflag & CSIZE) {
case CS5: dafo = SAB82532_DAFO_CHL5; bits = 7; break;
case CS6: dafo = SAB82532_DAFO_CHL6; bits = 8; break;
case CS7: dafo = SAB82532_DAFO_CHL7; bits = 9; break;
case CS8: dafo = SAB82532_DAFO_CHL8; bits = 10; break;
/* Never happens, but GCC is too dumb to figure it out */
default: dafo = SAB82532_DAFO_CHL5; bits = 7; break;
}
if (cflag & CSTOPB) {
dafo |= SAB82532_DAFO_STOP;
bits++;
}
if (cflag & PARENB) {
dafo |= SAB82532_DAFO_PARE;
bits++;
}
if (cflag & PARODD) {
dafo |= SAB82532_DAFO_PAR_ODD;
} else {
dafo |= SAB82532_DAFO_PAR_EVEN;
}
up->cached_dafo = dafo;
calc_ebrg(baud, &n, &m);
up->cached_ebrg = n | (m << 6);
up->tec_timeout = (10 * 1000000) / baud;
up->cec_timeout = up->tec_timeout >> 2;
/* CTS flow control flags */
/* We encode read_status_mask and ignore_status_mask like so:
*
* ---------------------
* | ... | ISR1 | ISR0 |
* ---------------------
* .. 15 8 7 0
*/
up->port.read_status_mask = (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
SAB82532_ISR0_RFO | SAB82532_ISR0_RPF |
SAB82532_ISR0_CDSC);
up->port.read_status_mask |= (SAB82532_ISR1_CSC |
SAB82532_ISR1_ALLS |
SAB82532_ISR1_XPR) << 8;
if (iflag & INPCK)
up->port.read_status_mask |= (SAB82532_ISR0_PERR |
SAB82532_ISR0_FERR);
if (iflag & (BRKINT | PARMRK))
up->port.read_status_mask |= (SAB82532_ISR1_BRK << 8);
/*
* Characteres to ignore
*/
up->port.ignore_status_mask = 0;
if (iflag & IGNPAR)
up->port.ignore_status_mask |= (SAB82532_ISR0_PERR |
SAB82532_ISR0_FERR);
if (iflag & IGNBRK) {
up->port.ignore_status_mask |= (SAB82532_ISR1_BRK << 8);
/*
* If we're ignoring parity and break indicators,
* ignore overruns too (for real raw support).
*/
if (iflag & IGNPAR)
up->port.ignore_status_mask |= SAB82532_ISR0_RFO;
}
/*
* ignore all characters if CREAD is not set
*/
if ((cflag & CREAD) == 0)
up->port.ignore_status_mask |= (SAB82532_ISR0_RPF |
SAB82532_ISR0_TCD);
uart_update_timeout(&up->port, cflag,
(up->port.uartclk / (16 * quot)));
/* Now schedule a register update when the chip's
* transmitter is idle.
*/
up->cached_mode |= SAB82532_MODE_RAC;
set_bit(SAB82532_REGS_PENDING, &up->irqflags);
if (test_bit(SAB82532_XPR, &up->irqflags))
sunsab_tx_idle(up);
}
/* port->lock is not held. */
static void sunsab_set_termios(struct uart_port *port, struct termios *termios,
struct termios *old)
{
struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
unsigned long flags;
unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
unsigned int quot = uart_get_divisor(port, baud);
spin_lock_irqsave(&up->port.lock, flags);
sunsab_convert_to_sab(up, termios->c_cflag, termios->c_iflag, baud, quot);
spin_unlock_irqrestore(&up->port.lock, flags);
}
static const char *sunsab_type(struct uart_port *port)
{
struct uart_sunsab_port *up = (void *)port;
static char buf[36];
sprintf(buf, "SAB82532 %s", sab82532_version[up->type]);
return buf;
}
static void sunsab_release_port(struct uart_port *port)
{
}
static int sunsab_request_port(struct uart_port *port)
{
return 0;
}
static void sunsab_config_port(struct uart_port *port, int flags)
{
}
static int sunsab_verify_port(struct uart_port *port, struct serial_struct *ser)
{
return -EINVAL;
}
static struct uart_ops sunsab_pops = {
.tx_empty = sunsab_tx_empty,
.set_mctrl = sunsab_set_mctrl,
.get_mctrl = sunsab_get_mctrl,
.stop_tx = sunsab_stop_tx,
.start_tx = sunsab_start_tx,
.send_xchar = sunsab_send_xchar,
.stop_rx = sunsab_stop_rx,
.enable_ms = sunsab_enable_ms,
.break_ctl = sunsab_break_ctl,
.startup = sunsab_startup,
.shutdown = sunsab_shutdown,
.set_termios = sunsab_set_termios,
.type = sunsab_type,
.release_port = sunsab_release_port,
.request_port = sunsab_request_port,
.config_port = sunsab_config_port,
.verify_port = sunsab_verify_port,
};
static struct uart_driver sunsab_reg = {
.owner = THIS_MODULE,
.driver_name = "serial",
.devfs_name = "tts/",
.dev_name = "ttyS",
.major = TTY_MAJOR,
};
static struct uart_sunsab_port *sunsab_ports;
static int num_channels;
#ifdef CONFIG_SERIAL_SUNSAB_CONSOLE
static __inline__ void sunsab_console_putchar(struct uart_sunsab_port *up, char c)
{
unsigned long flags;
spin_lock_irqsave(&up->port.lock, flags);
sunsab_tec_wait(up);
writeb(c, &up->regs->w.tic);
spin_unlock_irqrestore(&up->port.lock, flags);
}
static void sunsab_console_write(struct console *con, const char *s, unsigned n)
{
struct uart_sunsab_port *up = &sunsab_ports[con->index];
int i;
for (i = 0; i < n; i++) {
if (*s == '\n')
sunsab_console_putchar(up, '\r');
sunsab_console_putchar(up, *s++);
}
sunsab_tec_wait(up);
}
static int sunsab_console_setup(struct console *con, char *options)
{
struct uart_sunsab_port *up = &sunsab_ports[con->index];
unsigned long flags;
unsigned int baud, quot;
printk("Console: ttyS%d (SAB82532)\n",
(sunsab_reg.minor - 64) + con->index);
sunserial_console_termios(con);
/* Firmware console speed is limited to 150-->38400 baud so
* this hackish cflag thing is OK.
*/
switch (con->cflag & CBAUD) {
case B150: baud = 150; break;
case B300: baud = 300; break;
case B600: baud = 600; break;
case B1200: baud = 1200; break;
case B2400: baud = 2400; break;
case B4800: baud = 4800; break;
default: case B9600: baud = 9600; break;
case B19200: baud = 19200; break;
case B38400: baud = 38400; break;
};
/*
* Temporary fix.
*/
spin_lock_init(&up->port.lock);
/*
* Initialize the hardware
*/
sunsab_startup(&up->port);
spin_lock_irqsave(&up->port.lock, flags);
/*
* Finally, enable interrupts
*/
up->interrupt_mask0 = SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
SAB82532_IMR0_PLLA | SAB82532_IMR0_CDSC;
writeb(up->interrupt_mask0, &up->regs->w.imr0);
up->interrupt_mask1 = SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
SAB82532_IMR1_XPR;
writeb(up->interrupt_mask1, &up->regs->w.imr1);
quot = uart_get_divisor(&up->port, baud);
sunsab_convert_to_sab(up, con->cflag, 0, baud, quot);
sunsab_set_mctrl(&up->port, TIOCM_DTR | TIOCM_RTS);
spin_unlock_irqrestore(&up->port.lock, flags);
return 0;
}
static struct console sunsab_console = {
.name = "ttyS",
.write = sunsab_console_write,
.device = uart_console_device,
.setup = sunsab_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &sunsab_reg,
};
#define SUNSAB_CONSOLE (&sunsab_console)
static void __init sunsab_console_init(void)
{
int i;
if (con_is_present())
return;
for (i = 0; i < num_channels; i++) {
int this_minor = sunsab_reg.minor + i;
if ((this_minor - 64) == (serial_console - 1))
break;
}
if (i == num_channels)
return;
sunsab_console.index = i;
register_console(&sunsab_console);
}
#else
#define SUNSAB_CONSOLE (NULL)
#define sunsab_console_init() do { } while (0)
#endif
static void __init for_each_sab_edev(void (*callback)(struct linux_ebus_device *, void *), void *arg)
{
struct linux_ebus *ebus;
struct linux_ebus_device *edev = NULL;
for_each_ebus(ebus) {
for_each_ebusdev(edev, ebus) {
if (!strcmp(edev->prom_name, "se")) {
callback(edev, arg);
continue;
} else if (!strcmp(edev->prom_name, "serial")) {
char compat[32];
int clen;
/* On RIO this can be an SE, check it. We could
* just check ebus->is_rio, but this is more portable.
*/
clen = prom_getproperty(edev->prom_node, "compatible",
compat, sizeof(compat));
if (clen > 0) {
if (strncmp(compat, "sab82532", 8) == 0) {
callback(edev, arg);
continue;
}
}
}
}
}
}
static void __init sab_count_callback(struct linux_ebus_device *edev, void *arg)
{
int *count_p = arg;
(*count_p)++;
}
static void __init sab_attach_callback(struct linux_ebus_device *edev, void *arg)
{
int *instance_p = arg;
struct uart_sunsab_port *up;
unsigned long regs, offset;
int i;
/* Note: ports are located in reverse order */
regs = edev->resource[0].start;
offset = sizeof(union sab82532_async_regs);
for (i = 0; i < 2; i++) {
up = &sunsab_ports[(*instance_p * 2) + 1 - i];
memset(up, 0, sizeof(*up));
up->regs = ioremap(regs + offset, sizeof(union sab82532_async_regs));
up->port.irq = edev->irqs[0];
up->port.fifosize = SAB82532_XMIT_FIFO_SIZE;
up->port.mapbase = (unsigned long)up->regs;
up->port.iotype = SERIAL_IO_MEM;
writeb(SAB82532_IPC_IC_ACT_LOW, &up->regs->w.ipc);
offset -= sizeof(union sab82532_async_regs);
}
(*instance_p)++;
}
static int __init probe_for_sabs(void)
{
int this_sab = 0;
/* Find device instances. */
for_each_sab_edev(&sab_count_callback, &this_sab);
if (!this_sab)
return -ENODEV;
/* Allocate tables. */
sunsab_ports = kmalloc(sizeof(struct uart_sunsab_port) * this_sab * 2,
GFP_KERNEL);
if (!sunsab_ports)
return -ENOMEM;
num_channels = this_sab * 2;
this_sab = 0;
for_each_sab_edev(&sab_attach_callback, &this_sab);
return 0;
}
static void __init sunsab_init_hw(void)
{
int i;
for (i = 0; i < num_channels; i++) {
struct uart_sunsab_port *up = &sunsab_ports[i];
up->port.line = i;
up->port.ops = &sunsab_pops;
up->port.type = PORT_SUNSAB;
up->port.uartclk = SAB_BASE_BAUD;
up->type = readb(&up->regs->r.vstr) & 0x0f;
writeb(~((1 << 1) | (1 << 2) | (1 << 4)), &up->regs->w.pcr);
writeb(0xff, &up->regs->w.pim);
if (up->port.line == 0) {
up->pvr_dsr_bit = (1 << 0);
up->pvr_dtr_bit = (1 << 1);
} else {
up->pvr_dsr_bit = (1 << 3);
up->pvr_dtr_bit = (1 << 2);
}
up->cached_pvr = (1 << 1) | (1 << 2) | (1 << 4);
writeb(up->cached_pvr, &up->regs->w.pvr);
up->cached_mode = readb(&up->regs->rw.mode);
up->cached_mode |= SAB82532_MODE_FRTS;
writeb(up->cached_mode, &up->regs->rw.mode);
up->cached_mode |= SAB82532_MODE_RTS;
writeb(up->cached_mode, &up->regs->rw.mode);
up->tec_timeout = SAB82532_MAX_TEC_TIMEOUT;
up->cec_timeout = SAB82532_MAX_CEC_TIMEOUT;
if (!(up->port.line & 0x01)) {
if (request_irq(up->port.irq, sunsab_interrupt,
SA_SHIRQ, "serial(sab82532)", up)) {
printk("sunsab%d: can't get IRQ %x\n",
i, up->port.irq);
continue;
}
}
}
}
static int __init sunsab_init(void)
{
int ret = probe_for_sabs();
int i;
if (ret < 0)
return ret;
sunsab_init_hw();
sunsab_reg.minor = sunserial_current_minor;
sunsab_reg.nr = num_channels;
sunsab_reg.cons = SUNSAB_CONSOLE;
ret = uart_register_driver(&sunsab_reg);
if (ret < 0) {
int i;
for (i = 0; i < num_channels; i++) {
struct uart_sunsab_port *up = &sunsab_ports[i];
if (!(up->port.line & 0x01))
free_irq(up->port.irq, up);
iounmap(up->regs);
}
kfree(sunsab_ports);
sunsab_ports = NULL;
return ret;
}
sunserial_current_minor += num_channels;
sunsab_console_init();
for (i = 0; i < num_channels; i++) {
struct uart_sunsab_port *up = &sunsab_ports[i];
uart_add_one_port(&sunsab_reg, &up->port);
}
return 0;
}
static void __exit sunsab_exit(void)
{
int i;
for (i = 0; i < num_channels; i++) {
struct uart_sunsab_port *up = &sunsab_ports[i];
uart_remove_one_port(&sunsab_reg, &up->port);
if (!(up->port.line & 0x01))
free_irq(up->port.irq, up);
iounmap(up->regs);
}
sunserial_current_minor -= num_channels;
uart_unregister_driver(&sunsab_reg);
kfree(sunsab_ports);
sunsab_ports = NULL;
}
module_init(sunsab_init);
module_exit(sunsab_exit);
MODULE_AUTHOR("Eddie C. Dost and David S. Miller");
MODULE_DESCRIPTION("Sun SAB82532 serial port driver");
MODULE_LICENSE("GPL");
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