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linux/drivers/serial/sunsab.c
David Howells 7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers 
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00

1179 lines
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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, 2006 David S. Miller (davem@davemloft.net)
*
* 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@davemloft.net>
*/
#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/prom.h>
#include <asm/of_device.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 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], flag;
if (tty == NULL) {
uart_handle_sysrq_char(&up->port, ch);
continue;
}
flag = 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) {
flag = TTY_BREAK;
} else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
flag = TTY_PARITY;
else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
flag = TTY_FRAME;
}
if (uart_handle_sysrq_char(&up->port, ch))
continue;
if ((stat->sreg.isr0 & (up->port.ignore_status_mask & 0xff)) == 0 &&
(stat->sreg.isr1 & ((up->port.ignore_status_mask >> 8) & 0xff)) == 0)
tty_insert_flip_char(tty, ch, flag);
if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
tty_insert_flip_char(tty, 0, TTY_OVERRUN);
}
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 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);
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);
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",
.dev_name = "ttyS",
.major = TTY_MAJOR,
};
static struct uart_sunsab_port *sunsab_ports;
static int num_channels;
#ifdef CONFIG_SERIAL_SUNSAB_CONSOLE
static void sunsab_console_putchar(struct uart_port *port, int c)
{
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(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];
uart_console_write(&up->port, s, n, sunsab_console_putchar);
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;
/*
* The console framework calls us for each and every port
* registered. Defer the console setup until the requested
* port has been properly discovered. A bit of a hack,
* though...
*/
if (up->port.type != PORT_SUNSAB)
return -1;
printk("Console: ttyS%d (SAB82532)\n",
(sunsab_reg.minor - 64) + con->index);
sunserial_console_termios(con);
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;
case B57600: baud = 57600; break;
case B115200: baud = 115200; break;
case B230400: baud = 230400; break;
case B460800: baud = 460800; 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,
};
static inline struct console *SUNSAB_CONSOLE(void)
{
int i;
if (con_is_present())
return NULL;
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 NULL;
sunsab_console.index = i;
return &sunsab_console;
}
#else
#define SUNSAB_CONSOLE() (NULL)
#define sunsab_console_init() do { } while (0)
#endif
static int __devinit sunsab_init_one(struct uart_sunsab_port *up,
struct of_device *op,
unsigned long offset,
int line)
{
up->port.line = line;
up->port.dev = &op->dev;
up->port.mapbase = op->resource[0].start + offset;
up->port.membase = of_ioremap(&op->resource[0], offset,
sizeof(union sab82532_async_regs),
"sab");
if (!up->port.membase)
return -ENOMEM;
up->regs = (union sab82532_async_regs __iomem *) up->port.membase;
up->port.irq = op->irqs[0];
up->port.fifosize = SAB82532_XMIT_FIFO_SIZE;
up->port.iotype = UPIO_MEM;
writeb(SAB82532_IPC_IC_ACT_LOW, &up->regs->w.ipc);
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 & 0x1) == 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)) {
int err;
err = request_irq(up->port.irq, sunsab_interrupt,
IRQF_SHARED, "sab", up);
if (err) {
of_iounmap(up->port.membase,
sizeof(union sab82532_async_regs));
return err;
}
}
return 0;
}
static int __devinit sab_probe(struct of_device *op, const struct of_device_id *match)
{
static int inst;
struct uart_sunsab_port *up;
int err;
up = &sunsab_ports[inst * 2];
err = sunsab_init_one(&up[0], op,
0,
(inst * 2) + 0);
if (err)
return err;
err = sunsab_init_one(&up[1], op,
sizeof(union sab82532_async_regs),
(inst * 2) + 1);
if (err) {
of_iounmap(up[0].port.membase,
sizeof(union sab82532_async_regs));
free_irq(up[0].port.irq, &up[0]);
return err;
}
uart_add_one_port(&sunsab_reg, &up[0].port);
uart_add_one_port(&sunsab_reg, &up[1].port);
dev_set_drvdata(&op->dev, &up[0]);
inst++;
return 0;
}
static void __devexit sab_remove_one(struct uart_sunsab_port *up)
{
uart_remove_one_port(&sunsab_reg, &up->port);
if (!(up->port.line & 1))
free_irq(up->port.irq, up);
of_iounmap(up->port.membase,
sizeof(union sab82532_async_regs));
}
static int __devexit sab_remove(struct of_device *op)
{
struct uart_sunsab_port *up = dev_get_drvdata(&op->dev);
sab_remove_one(&up[0]);
sab_remove_one(&up[1]);
dev_set_drvdata(&op->dev, NULL);
return 0;
}
static struct of_device_id sab_match[] = {
{
.name = "se",
},
{
.name = "serial",
.compatible = "sab82532",
},
{},
};
MODULE_DEVICE_TABLE(of, sab_match);
static struct of_platform_driver sab_driver = {
.name = "sab",
.match_table = sab_match,
.probe = sab_probe,
.remove = __devexit_p(sab_remove),
};
static int __init sunsab_init(void)
{
struct device_node *dp;
int err;
num_channels = 0;
for_each_node_by_name(dp, "se")
num_channels += 2;
for_each_node_by_name(dp, "serial") {
if (of_device_is_compatible(dp, "sab82532"))
num_channels += 2;
}
if (num_channels) {
sunsab_ports = kzalloc(sizeof(struct uart_sunsab_port) *
num_channels, GFP_KERNEL);
if (!sunsab_ports)
return -ENOMEM;
sunsab_reg.minor = sunserial_current_minor;
sunsab_reg.nr = num_channels;
err = uart_register_driver(&sunsab_reg);
if (err) {
kfree(sunsab_ports);
sunsab_ports = NULL;
return err;
}
sunsab_reg.tty_driver->name_base = sunsab_reg.minor - 64;
sunsab_reg.cons = SUNSAB_CONSOLE();
sunserial_current_minor += num_channels;
}
return of_register_driver(&sab_driver, &of_bus_type);
}
static void __exit sunsab_exit(void)
{
of_unregister_driver(&sab_driver);
if (num_channels) {
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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