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linux/drivers/serial/m32r_sio.c
Alan Cox 33f0f88f1c [PATCH] TTY layer buffering revamp 
The API and code have been through various bits of initial review by
serial driver people but they definitely need to live somewhere for a
while so the unconverted drivers can get knocked into shape, existing
drivers that have been updated can be better tuned and bugs whacked out.

This replaces the tty flip buffers with kmalloc objects in rings. In the
normal situation for an IRQ driven serial port at typical speeds the
behaviour is pretty much the same, two buffers end up allocated and the
kernel cycles between them as before.

When there are delays or at high speed we now behave far better as the
buffer pool can grow a bit rather than lose characters. This also means
that we can operate at higher speeds reliably.

For drivers that receive characters in blocks (DMA based, USB and
especially virtualisation) the layer allows a lot of driver specific
code that works around the tty layer with private secondary queues to be
removed. The IBM folks need this sort of layer, the smart serial port
people do, the virtualisers do (because a virtualised tty typically
operates at infinite speed rather than emulating 9600 baud).

Finally many drivers had invalid and unsafe attempts to avoid buffer
overflows by directly invoking tty methods extracted out of the innards
of work queue structs. These are no longer needed and all go away. That
fixes various random hangs with serial ports on overflow.

The other change in here is to optimise the receive_room path that is
used by some callers. It turns out that only one ldisc uses receive room
except asa constant and it updates it far far less than the value is
read. We thus make it a variable not a function call.

I expect the code to contain bugs due to the size alone but I'll be
watching and squashing them and feeding out new patches as it goes.

Because the buffers now dynamically expand you should only run out of
buffering when the kernel runs out of memory for real.  That means a lot of
the horrible hacks high performance drivers used to do just aren't needed any
more.

Description:

tty_insert_flip_char is an old API and continues to work as before, as does
tty_flip_buffer_push() [this is why many drivers dont need modification].  It
does now also return the number of chars inserted

There are also

tty_buffer_request_room(tty, len)

which asks for a buffer block of the length requested and returns the space
found.  This improves efficiency with hardware that knows how much to
transfer.

and tty_insert_flip_string_flags(tty, str, flags, len)

to insert a string of characters and flags

For a smart interface the usual code is

    len = tty_request_buffer_room(tty, amount_hardware_says);
    tty_insert_flip_string(tty, buffer_from_card, len);

More description!

At the moment tty buffers are attached directly to the tty.  This is causing a
lot of the problems related to tty layer locking, also problems at high speed
and also with bursty data (such as occurs in virtualised environments)

I'm working on ripping out the flip buffers and replacing them with a pool of
dynamically allocated buffers.  This allows both for old style "byte I/O"
devices and also helps virtualisation and smart devices where large blocks of
data suddenely materialise and need storing.

So far so good.  Lots of drivers reference tty->flip.*.  Several of them also
call directly and unsafely into function pointers it provides.  This will all
break.  Most drivers can use tty_insert_flip_char which can be kept as an API
but others need more.

At the moment I've added the following interfaces, if people think more will
be needed now is a good time to say

 int tty_buffer_request_room(tty, size)

Try and ensure at least size bytes are available, returns actual room (may be
zero).  At the moment it just uses the flipbuf space but that will change.
Repeated calls without characters being added are not cumulative.  (ie if you
call it with 1, 1, 1, and then 4 you'll have four characters of space.  The
other functions will also try and grow buffers in future but this will be a
more efficient way when you know block sizes.

 int tty_insert_flip_char(tty, ch, flag)

As before insert a character if there is room.  Now returns 1 for success, 0
for failure.

 int tty_insert_flip_string(tty, str, len)

Insert a block of non error characters.  Returns the number inserted.

 int tty_prepare_flip_string(tty, strptr, len)

Adjust the buffer to allow len characters to be added.  Returns a buffer
pointer in strptr and the length available.  This allows for hardware that
needs to use functions like insl or mencpy_fromio.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10 08:01:59 -08:00

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/*
* m32r_sio.c
*
* Driver for M32R serial ports
*
* Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
* Based on drivers/serial/8250.c.
*
* Copyright (C) 2001 Russell King.
* Copyright (C) 2004 Hirokazu Takata <takata at linux-m32r.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
/*
* A note about mapbase / membase
*
* mapbase is the physical address of the IO port. Currently, we don't
* support this very well, and it may well be dropped from this driver
* in future. As such, mapbase should be NULL.
*
* membase is an 'ioremapped' cookie. This is compatible with the old
* serial.c driver, and is currently the preferred form.
*/
#include <linux/config.h>
#if defined(CONFIG_SERIAL_M32R_SIO_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#include <linux/module.h>
#include <linux/tty.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/serial.h>
#include <linux/serialP.h>
#include <linux/delay.h>
#include <asm/m32r.h>
#include <asm/io.h>
#include <asm/irq.h>
#define PORT_M32R_BASE PORT_M32R_SIO
#define PORT_INDEX(x) (x - PORT_M32R_BASE + 1)
#define BAUD_RATE 115200
#include <linux/serial_core.h>
#include "m32r_sio.h"
#include "m32r_sio_reg.h"
/*
* Debugging.
*/
#if 0
#define DEBUG_AUTOCONF(fmt...) printk(fmt)
#else
#define DEBUG_AUTOCONF(fmt...) do { } while (0)
#endif
#if 0
#define DEBUG_INTR(fmt...) printk(fmt)
#else
#define DEBUG_INTR(fmt...) do { } while (0)
#endif
#define PASS_LIMIT 256
/*
* We default to IRQ0 for the "no irq" hack. Some
* machine types want others as well - they're free
* to redefine this in their header file.
*/
#define is_real_interrupt(irq) ((irq) != 0)
#include <asm/serial.h>
/* Standard COM flags */
#define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST)
/*
* SERIAL_PORT_DFNS tells us about built-in ports that have no
* standard enumeration mechanism. Platforms that can find all
* serial ports via mechanisms like ACPI or PCI need not supply it.
*/
#undef SERIAL_PORT_DFNS
#if defined(CONFIG_PLAT_USRV)
#define SERIAL_PORT_DFNS \
/* UART CLK PORT IRQ FLAGS */ \
{ 0, BASE_BAUD, 0x3F8, PLD_IRQ_UART0, STD_COM_FLAGS }, /* ttyS0 */ \
{ 0, BASE_BAUD, 0x2F8, PLD_IRQ_UART1, STD_COM_FLAGS }, /* ttyS1 */
#else /* !CONFIG_PLAT_USRV */
#if defined(CONFIG_SERIAL_M32R_PLDSIO)
#define SERIAL_PORT_DFNS \
{ 0, BASE_BAUD, ((unsigned long)PLD_ESIO0CR), PLD_IRQ_SIO0_RCV, \
STD_COM_FLAGS }, /* ttyS0 */
#else
#define SERIAL_PORT_DFNS \
{ 0, BASE_BAUD, M32R_SIO_OFFSET, M32R_IRQ_SIO0_R, \
STD_COM_FLAGS }, /* ttyS0 */
#endif
#endif /* !CONFIG_PLAT_USRV */
static struct old_serial_port old_serial_port[] = {
SERIAL_PORT_DFNS /* defined in asm/serial.h */
};
#define UART_NR ARRAY_SIZE(old_serial_port)
struct uart_sio_port {
struct uart_port port;
struct timer_list timer; /* "no irq" timer */
struct list_head list; /* ports on this IRQ */
unsigned short rev;
unsigned char acr;
unsigned char ier;
unsigned char lcr;
unsigned char mcr_mask; /* mask of user bits */
unsigned char mcr_force; /* mask of forced bits */
unsigned char lsr_break_flag;
/*
* We provide a per-port pm hook.
*/
void (*pm)(struct uart_port *port,
unsigned int state, unsigned int old);
};
struct irq_info {
spinlock_t lock;
struct list_head *head;
};
static struct irq_info irq_lists[NR_IRQS];
/*
* Here we define the default xmit fifo size used for each type of UART.
*/
static const struct serial_uart_config uart_config[] = {
[PORT_UNKNOWN] = {
.name = "unknown",
.dfl_xmit_fifo_size = 1,
.flags = 0,
},
[PORT_INDEX(PORT_M32R_SIO)] = {
.name = "M32RSIO",
.dfl_xmit_fifo_size = 1,
.flags = 0,
},
};
#ifdef CONFIG_SERIAL_M32R_PLDSIO
#define __sio_in(x) inw((unsigned long)(x))
#define __sio_out(v,x) outw((v),(unsigned long)(x))
static inline void sio_set_baud_rate(unsigned long baud)
{
unsigned short sbaud;
sbaud = (boot_cpu_data.bus_clock / (baud * 4))-1;
__sio_out(sbaud, PLD_ESIO0BAUR);
}
static void sio_reset(void)
{
unsigned short tmp;
tmp = __sio_in(PLD_ESIO0RXB);
tmp = __sio_in(PLD_ESIO0RXB);
tmp = __sio_in(PLD_ESIO0CR);
sio_set_baud_rate(BAUD_RATE);
__sio_out(0x0300, PLD_ESIO0CR);
__sio_out(0x0003, PLD_ESIO0CR);
}
static void sio_init(void)
{
unsigned short tmp;
tmp = __sio_in(PLD_ESIO0RXB);
tmp = __sio_in(PLD_ESIO0RXB);
tmp = __sio_in(PLD_ESIO0CR);
__sio_out(0x0300, PLD_ESIO0CR);
__sio_out(0x0003, PLD_ESIO0CR);
}
static void sio_error(int *status)
{
printk("SIO0 error[%04x]\n", *status);
do {
sio_init();
} while ((*status = __sio_in(PLD_ESIO0CR)) != 3);
}
#else /* not CONFIG_SERIAL_M32R_PLDSIO */
#define __sio_in(x) inl(x)
#define __sio_out(v,x) outl((v),(x))
static inline void sio_set_baud_rate(unsigned long baud)
{
unsigned long i, j;
i = boot_cpu_data.bus_clock / (baud * 16);
j = (boot_cpu_data.bus_clock - (i * baud * 16)) / baud;
i -= 1;
j = (j + 1) >> 1;
__sio_out(i, M32R_SIO0_BAUR_PORTL);
__sio_out(j, M32R_SIO0_RBAUR_PORTL);
}
static void sio_reset(void)
{
__sio_out(0x00000300, M32R_SIO0_CR_PORTL); /* init status */
__sio_out(0x00000800, M32R_SIO0_MOD1_PORTL); /* 8bit */
__sio_out(0x00000080, M32R_SIO0_MOD0_PORTL); /* 1stop non */
sio_set_baud_rate(BAUD_RATE);
__sio_out(0x00000000, M32R_SIO0_TRCR_PORTL);
__sio_out(0x00000003, M32R_SIO0_CR_PORTL); /* RXCEN */
}
static void sio_init(void)
{
unsigned int tmp;
tmp = __sio_in(M32R_SIO0_RXB_PORTL);
tmp = __sio_in(M32R_SIO0_RXB_PORTL);
tmp = __sio_in(M32R_SIO0_STS_PORTL);
__sio_out(0x00000003, M32R_SIO0_CR_PORTL);
}
static void sio_error(int *status)
{
printk("SIO0 error[%04x]\n", *status);
do {
sio_init();
} while ((*status = __sio_in(M32R_SIO0_CR_PORTL)) != 3);
}
#endif /* CONFIG_SERIAL_M32R_PLDSIO */
static _INLINE_ unsigned int sio_in(struct uart_sio_port *up, int offset)
{
return __sio_in(up->port.iobase + offset);
}
static _INLINE_ void sio_out(struct uart_sio_port *up, int offset, int value)
{
__sio_out(value, up->port.iobase + offset);
}
static _INLINE_ unsigned int serial_in(struct uart_sio_port *up, int offset)
{
if (!offset)
return 0;
return __sio_in(offset);
}
static _INLINE_ void
serial_out(struct uart_sio_port *up, int offset, int value)
{
if (!offset)
return;
__sio_out(value, offset);
}
static void m32r_sio_stop_tx(struct uart_port *port)
{
struct uart_sio_port *up = (struct uart_sio_port *)port;
if (up->ier & UART_IER_THRI) {
up->ier &= ~UART_IER_THRI;
serial_out(up, UART_IER, up->ier);
}
}
static void m32r_sio_start_tx(struct uart_port *port)
{
#ifdef CONFIG_SERIAL_M32R_PLDSIO
struct uart_sio_port *up = (struct uart_sio_port *)port;
struct circ_buf *xmit = &up->port.info->xmit;
if (!(up->ier & UART_IER_THRI)) {
up->ier |= UART_IER_THRI;
serial_out(up, UART_IER, up->ier);
serial_out(up, UART_TX, xmit->buf[xmit->tail]);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
up->port.icount.tx++;
}
while((serial_in(up, UART_LSR) & UART_EMPTY) != UART_EMPTY);
#else
struct uart_sio_port *up = (struct uart_sio_port *)port;
if (!(up->ier & UART_IER_THRI)) {
up->ier |= UART_IER_THRI;
serial_out(up, UART_IER, up->ier);
}
#endif
}
static void m32r_sio_stop_rx(struct uart_port *port)
{
struct uart_sio_port *up = (struct uart_sio_port *)port;
up->ier &= ~UART_IER_RLSI;
up->port.read_status_mask &= ~UART_LSR_DR;
serial_out(up, UART_IER, up->ier);
}
static void m32r_sio_enable_ms(struct uart_port *port)
{
struct uart_sio_port *up = (struct uart_sio_port *)port;
up->ier |= UART_IER_MSI;
serial_out(up, UART_IER, up->ier);
}
static _INLINE_ void receive_chars(struct uart_sio_port *up, int *status,
struct pt_regs *regs)
{
struct tty_struct *tty = up->port.info->tty;
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, regs))
goto ignore_char;
if ((*status & up->port.ignore_status_mask) == 0)
tty_insert_flip_char(tty, 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(tty, 0, TTY_OVERRUN);
}
ignore_char:
*status = serial_in(up, UART_LSR);
} while ((*status & UART_LSR_DR) && (max_count-- > 0));
tty_flip_buffer_push(tty);
}
static _INLINE_ void transmit_chars(struct uart_sio_port *up)
{
struct circ_buf *xmit = &up->port.info->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);
}
/*
* This handles the interrupt from one port.
*/
static inline void m32r_sio_handle_port(struct uart_sio_port *up,
unsigned int status, struct pt_regs *regs)
{
DEBUG_INTR("status = %x...", status);
if (status & 0x04)
receive_chars(up, &status, regs);
if (status & 0x01)
transmit_chars(up);
}
/*
* 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 pt_regs *regs)
{
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, 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 (sts & 0xe0)
sio_error(&sts);
break;
}
} while (l != end);
spin_unlock(&i->lock);
DEBUG_INTR("end.\n");
return IRQ_HANDLED;
}
/*
* To support ISA shared interrupts, we need to have one interrupt
* handler that ensures that the IRQ line has been deasserted
* before returning. Failing to do this will result in the IRQ
* line being stuck active, and, since ISA irqs are edge triggered,
* no more IRQs will be seen.
*/
static void serial_do_unlink(struct irq_info *i, struct uart_sio_port *up)
{
spin_lock_irq(&i->lock);
if (!list_empty(i->head)) {
if (i->head == &up->list)
i->head = i->head->next;
list_del(&up->list);
} else {
BUG_ON(i->head != &up->list);
i->head = NULL;
}
spin_unlock_irq(&i->lock);
}
static int serial_link_irq_chain(struct uart_sio_port *up)
{
struct irq_info *i = irq_lists + up->port.irq;
int ret, irq_flags = up->port.flags & UPF_SHARE_IRQ ? SA_SHIRQ : 0;
spin_lock_irq(&i->lock);
if (i->head) {
list_add(&up->list, i->head);
spin_unlock_irq(&i->lock);
ret = 0;
} else {
INIT_LIST_HEAD(&up->list);
i->head = &up->list;
spin_unlock_irq(&i->lock);
ret = request_irq(up->port.irq, m32r_sio_interrupt,
irq_flags, "SIO0-RX", i);
ret |= request_irq(up->port.irq + 1, m32r_sio_interrupt,
irq_flags, "SIO0-TX", i);
if (ret < 0)
serial_do_unlink(i, up);
}
return ret;
}
static void serial_unlink_irq_chain(struct uart_sio_port *up)
{
struct irq_info *i = irq_lists + up->port.irq;
BUG_ON(i->head == NULL);
if (list_empty(i->head)) {
free_irq(up->port.irq, i);
free_irq(up->port.irq + 1, i);
}
serial_do_unlink(i, up);
}
/*
* This function is used to handle ports that do not have an interrupt.
*/
static void m32r_sio_timeout(unsigned long data)
{
struct uart_sio_port *up = (struct uart_sio_port *)data;
unsigned int timeout;
unsigned int sts;
sts = sio_in(up, SIOSTS);
if (sts & 0x5) {
spin_lock(&up->port.lock);
m32r_sio_handle_port(up, sts, NULL);
spin_unlock(&up->port.lock);
}
timeout = up->port.timeout;
timeout = timeout > 6 ? (timeout / 2 - 2) : 1;
mod_timer(&up->timer, jiffies + timeout);
}
static unsigned int m32r_sio_tx_empty(struct uart_port *port)
{
struct uart_sio_port *up = (struct uart_sio_port *)port;
unsigned long flags;
unsigned int ret;
spin_lock_irqsave(&up->port.lock, flags);
ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
spin_unlock_irqrestore(&up->port.lock, flags);
return ret;
}
static unsigned int m32r_sio_get_mctrl(struct uart_port *port)
{
return 0;
}
static void m32r_sio_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
}
static void m32r_sio_break_ctl(struct uart_port *port, int break_state)
{
}
static int m32r_sio_startup(struct uart_port *port)
{
struct uart_sio_port *up = (struct uart_sio_port *)port;
int retval;
sio_init();
/*
* If the "interrupt" for this port doesn't correspond with any
* hardware interrupt, we use a timer-based system. The original
* driver used to do this with IRQ0.
*/
if (!is_real_interrupt(up->port.irq)) {
unsigned int timeout = up->port.timeout;
timeout = timeout > 6 ? (timeout / 2 - 2) : 1;
up->timer.data = (unsigned long)up;
mod_timer(&up->timer, jiffies + timeout);
} else {
retval = serial_link_irq_chain(up);
if (retval)
return retval;
}
/*
* Finally, enable interrupts. Note: Modem status interrupts
* are set via set_termios(), which will be occurring imminently
* anyway, so we don't enable them here.
* - M32R_SIO: 0x0c
* - M32R_PLDSIO: 0x04
*/
up->ier = UART_IER_MSI | UART_IER_RLSI | UART_IER_RDI;
sio_out(up, SIOTRCR, up->ier);
/*
* And clear the interrupt registers again for luck.
*/
sio_reset();
return 0;
}
static void m32r_sio_shutdown(struct uart_port *port)
{
struct uart_sio_port *up = (struct uart_sio_port *)port;
/*
* Disable interrupts from this port
*/
up->ier = 0;
sio_out(up, SIOTRCR, 0);
/*
* Disable break condition and FIFOs
*/
sio_init();
if (!is_real_interrupt(up->port.irq))
del_timer_sync(&up->timer);
else
serial_unlink_irq_chain(up);
}
static unsigned int m32r_sio_get_divisor(struct uart_port *port,
unsigned int baud)
{
return uart_get_divisor(port, baud);
}
static void m32r_sio_set_termios(struct uart_port *port,
struct termios *termios, struct termios *old)
{
struct uart_sio_port *up = (struct uart_sio_port *)port;
unsigned char cval = 0;
unsigned long flags;
unsigned int baud, quot;
switch (termios->c_cflag & CSIZE) {
case CS5:
cval = UART_LCR_WLEN5;
break;
case CS6:
cval = UART_LCR_WLEN6;
break;
case CS7:
cval = UART_LCR_WLEN7;
break;
default:
case CS8:
cval = UART_LCR_WLEN8;
break;
}
if (termios->c_cflag & CSTOPB)
cval |= UART_LCR_STOP;
if (termios->c_cflag & PARENB)
cval |= UART_LCR_PARITY;
if (!(termios->c_cflag & PARODD))
cval |= UART_LCR_EPAR;
#ifdef CMSPAR
if (termios->c_cflag & CMSPAR)
cval |= UART_LCR_SPAR;
#endif
/*
* Ask the core to calculate the divisor for us.
*/
#ifdef CONFIG_SERIAL_M32R_PLDSIO
baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/4);
#else
baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
#endif
quot = m32r_sio_get_divisor(port, baud);
/*
* Ok, we're now changing the port state. Do it with
* interrupts disabled.
*/
spin_lock_irqsave(&up->port.lock, flags);
sio_set_baud_rate(baud);
/*
* Update the per-port timeout.
*/
uart_update_timeout(port, termios->c_cflag, baud);
up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
if (termios->c_iflag & INPCK)
up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
if (termios->c_iflag & (BRKINT | PARMRK))
up->port.read_status_mask |= UART_LSR_BI;
/*
* Characteres to ignore
*/
up->port.ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
if (termios->c_iflag & IGNBRK) {
up->port.ignore_status_mask |= UART_LSR_BI;
/*
* If we're ignoring parity and break indicators,
* ignore overruns too (for real raw support).
*/
if (termios->c_iflag & IGNPAR)
up->port.ignore_status_mask |= UART_LSR_OE;
}
/*
* ignore all characters if CREAD is not set
*/
if ((termios->c_cflag & CREAD) == 0)
up->port.ignore_status_mask |= UART_LSR_DR;
/*
* CTS flow control flag and modem status interrupts
*/
up->ier &= ~UART_IER_MSI;
if (UART_ENABLE_MS(&up->port, termios->c_cflag))
up->ier |= UART_IER_MSI;
serial_out(up, UART_IER, up->ier);
up->lcr = cval; /* Save LCR */
spin_unlock_irqrestore(&up->port.lock, flags);
}
static void m32r_sio_pm(struct uart_port *port, unsigned int state,
unsigned int oldstate)
{
struct uart_sio_port *up = (struct uart_sio_port *)port;
if (up->pm)
up->pm(port, state, oldstate);
}
/*
* Resource handling. This is complicated by the fact that resources
* depend on the port type. Maybe we should be claiming the standard
* 8250 ports, and then trying to get other resources as necessary?
*/
static int
m32r_sio_request_std_resource(struct uart_sio_port *up, struct resource **res)
{
unsigned int size = 8 << up->port.regshift;
#ifndef CONFIG_SERIAL_M32R_PLDSIO
unsigned long start;
#endif
int ret = 0;
switch (up->port.iotype) {
case UPIO_MEM:
if (up->port.mapbase) {
#ifdef CONFIG_SERIAL_M32R_PLDSIO
*res = request_mem_region(up->port.mapbase, size, "serial");
#else
start = up->port.mapbase;
*res = request_mem_region(start, size, "serial");
#endif
if (!*res)
ret = -EBUSY;
}
break;
case UPIO_PORT:
*res = request_region(up->port.iobase, size, "serial");
if (!*res)
ret = -EBUSY;
break;
}
return ret;
}
static void m32r_sio_release_port(struct uart_port *port)
{
struct uart_sio_port *up = (struct uart_sio_port *)port;
unsigned long start, offset = 0, size = 0;
size <<= up->port.regshift;
switch (up->port.iotype) {
case UPIO_MEM:
if (up->port.mapbase) {
/*
* Unmap the area.
*/
iounmap(up->port.membase);
up->port.membase = NULL;
start = up->port.mapbase;
if (size)
release_mem_region(start + offset, size);
release_mem_region(start, 8 << up->port.regshift);
}
break;
case UPIO_PORT:
start = up->port.iobase;
if (size)
release_region(start + offset, size);
release_region(start + offset, 8 << up->port.regshift);
break;
default:
break;
}
}
static int m32r_sio_request_port(struct uart_port *port)
{
struct uart_sio_port *up = (struct uart_sio_port *)port;
struct resource *res = NULL;
int ret = 0;
ret = m32r_sio_request_std_resource(up, &res);
/*
* If we have a mapbase, then request that as well.
*/
if (ret == 0 && up->port.flags & UPF_IOREMAP) {
int size = res->end - res->start + 1;
up->port.membase = ioremap(up->port.mapbase, size);
if (!up->port.membase)
ret = -ENOMEM;
}
if (ret < 0) {
if (res)
release_resource(res);
}
return ret;
}
static void m32r_sio_config_port(struct uart_port *port, int flags)
{
struct uart_sio_port *up = (struct uart_sio_port *)port;
spin_lock_irqsave(&up->port.lock, flags);
up->port.type = (PORT_M32R_SIO - PORT_M32R_BASE + 1);
up->port.fifosize = uart_config[up->port.type].dfl_xmit_fifo_size;
spin_unlock_irqrestore(&up->port.lock, flags);
}
static int
m32r_sio_verify_port(struct uart_port *port, struct serial_struct *ser)
{
if (ser->irq >= NR_IRQS || ser->irq < 0 ||
ser->baud_base < 9600 || ser->type < PORT_UNKNOWN ||
ser->type >= ARRAY_SIZE(uart_config))
return -EINVAL;
return 0;
}
static const char *
m32r_sio_type(struct uart_port *port)
{
int type = port->type;
if (type >= ARRAY_SIZE(uart_config))
type = 0;
return uart_config[type].name;
}
static struct uart_ops m32r_sio_pops = {
.tx_empty = m32r_sio_tx_empty,
.set_mctrl = m32r_sio_set_mctrl,
.get_mctrl = m32r_sio_get_mctrl,
.stop_tx = m32r_sio_stop_tx,
.start_tx = m32r_sio_start_tx,
.stop_rx = m32r_sio_stop_rx,
.enable_ms = m32r_sio_enable_ms,
.break_ctl = m32r_sio_break_ctl,
.startup = m32r_sio_startup,
.shutdown = m32r_sio_shutdown,
.set_termios = m32r_sio_set_termios,
.pm = m32r_sio_pm,
.type = m32r_sio_type,
.release_port = m32r_sio_release_port,
.request_port = m32r_sio_request_port,
.config_port = m32r_sio_config_port,
.verify_port = m32r_sio_verify_port,
};
static struct uart_sio_port m32r_sio_ports[UART_NR];
static void __init m32r_sio_init_ports(void)
{
struct uart_sio_port *up;
static int first = 1;
int i;
if (!first)
return;
first = 0;
for (i = 0, up = m32r_sio_ports; i < ARRAY_SIZE(old_serial_port);
i++, up++) {
up->port.iobase = old_serial_port[i].port;
up->port.irq = irq_canonicalize(old_serial_port[i].irq);
up->port.uartclk = old_serial_port[i].baud_base * 16;
up->port.flags = old_serial_port[i].flags;
up->port.membase = old_serial_port[i].iomem_base;
up->port.iotype = old_serial_port[i].io_type;
up->port.regshift = old_serial_port[i].iomem_reg_shift;
up->port.ops = &m32r_sio_pops;
}
}
static void __init m32r_sio_register_ports(struct uart_driver *drv)
{
int i;
m32r_sio_init_ports();
for (i = 0; i < UART_NR; i++) {
struct uart_sio_port *up = &m32r_sio_ports[i];
up->port.line = i;
up->port.ops = &m32r_sio_pops;
init_timer(&up->timer);
up->timer.function = m32r_sio_timeout;
/*
* ALPHA_KLUDGE_MCR needs to be killed.
*/
up->mcr_mask = ~ALPHA_KLUDGE_MCR;
up->mcr_force = ALPHA_KLUDGE_MCR;
uart_add_one_port(drv, &up->port);
}
}
#ifdef CONFIG_SERIAL_M32R_SIO_CONSOLE
/*
* Wait for transmitter & holding register to empty
*/
static inline void wait_for_xmitr(struct uart_sio_port *up)
{
unsigned int status, tmout = 10000;
/* Wait up to 10ms for the character(s) to be sent. */
do {
status = sio_in(up, SIOSTS);
if (--tmout == 0)
break;
udelay(1);
} while ((status & UART_EMPTY) != UART_EMPTY);
/* Wait up to 1s for flow control if necessary */
if (up->port.flags & UPF_CONS_FLOW) {
tmout = 1000000;
while (--tmout)
udelay(1);
}
}
/*
* Print a string to the serial port trying not to disturb
* any possible real use of the port...
*
* The console_lock must be held when we get here.
*/
static void m32r_sio_console_write(struct console *co, const char *s,
unsigned int count)
{
struct uart_sio_port *up = &m32r_sio_ports[co->index];
unsigned int ier;
int i;
/*
* First save the UER then disable the interrupts
*/
ier = sio_in(up, SIOTRCR);
sio_out(up, SIOTRCR, 0);
/*
* Now, do each character
*/
for (i = 0; i < count; i++, s++) {
wait_for_xmitr(up);
/*
* Send the character out.
* If a LF, also do CR...
*/
sio_out(up, SIOTXB, *s);
if (*s == 10) {
wait_for_xmitr(up);
sio_out(up, SIOTXB, 13);
}
}
/*
* Finally, wait for transmitter to become empty
* and restore the IER
*/
wait_for_xmitr(up);
sio_out(up, SIOTRCR, ier);
}
static int __init m32r_sio_console_setup(struct console *co, char *options)
{
struct uart_port *port;
int baud = 9600;
int bits = 8;
int parity = 'n';
int flow = 'n';
/*
* Check whether an invalid uart number has been specified, and
* if so, search for the first available port that does have
* console support.
*/
if (co->index >= UART_NR)
co->index = 0;
port = &m32r_sio_ports[co->index].port;
/*
* Temporary fix.
*/
spin_lock_init(&port->lock);
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
return uart_set_options(port, co, baud, parity, bits, flow);
}
static struct uart_driver m32r_sio_reg;
static struct console m32r_sio_console = {
.name = "ttyS",
.write = m32r_sio_console_write,
.device = uart_console_device,
.setup = m32r_sio_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &m32r_sio_reg,
};
static int __init m32r_sio_console_init(void)
{
sio_reset();
sio_init();
m32r_sio_init_ports();
register_console(&m32r_sio_console);
return 0;
}
console_initcall(m32r_sio_console_init);
#define M32R_SIO_CONSOLE &m32r_sio_console
#else
#define M32R_SIO_CONSOLE NULL
#endif
static struct uart_driver m32r_sio_reg = {
.owner = THIS_MODULE,
.driver_name = "sio",
.devfs_name = "tts/",
.dev_name = "ttyS",
.major = TTY_MAJOR,
.minor = 64,
.nr = UART_NR,
.cons = M32R_SIO_CONSOLE,
};
/**
* m32r_sio_suspend_port - suspend one serial port
* @line: serial line number
*
* Suspend one serial port.
*/
void m32r_sio_suspend_port(int line)
{
uart_suspend_port(&m32r_sio_reg, &m32r_sio_ports[line].port);
}
/**
* m32r_sio_resume_port - resume one serial port
* @line: serial line number
*
* Resume one serial port.
*/
void m32r_sio_resume_port(int line)
{
uart_resume_port(&m32r_sio_reg, &m32r_sio_ports[line].port);
}
static int __init m32r_sio_init(void)
{
int ret, i;
printk(KERN_INFO "Serial: M32R SIO driver $Revision: 1.11 $ ");
for (i = 0; i < NR_IRQS; i++)
spin_lock_init(&irq_lists[i].lock);
ret = uart_register_driver(&m32r_sio_reg);
if (ret >= 0)
m32r_sio_register_ports(&m32r_sio_reg);
return ret;
}
static void __exit m32r_sio_exit(void)
{
int i;
for (i = 0; i < UART_NR; i++)
uart_remove_one_port(&m32r_sio_reg, &m32r_sio_ports[i].port);
uart_unregister_driver(&m32r_sio_reg);
}
module_init(m32r_sio_init);
module_exit(m32r_sio_exit);
EXPORT_SYMBOL(m32r_sio_suspend_port);
EXPORT_SYMBOL(m32r_sio_resume_port);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Generic M32R SIO serial driver $Revision: 1.11 $");
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