renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-26 06:04:14 +08:00
Code
24669f75a3
linux-next/drivers/serial/mpc52xx_uart.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

843 lines
22 KiB
C
Raw Blame History

/*
* drivers/serial/mpc52xx_uart.c
*
* Driver for the PSC of the Freescale MPC52xx PSCs configured as UARTs.
*
* FIXME According to the usermanual the status bits in the status register
* are only updated when the peripherals access the FIFO and not when the
* CPU access them. So since we use this bits to know when we stop writing
* and reading, they may not be updated in-time and a race condition may
* exists. But I haven't be able to prove this and I don't care. But if
* any problem arises, it might worth checking. The TX/RX FIFO Stats
* registers should be used in addition.
* Update: Actually, they seem updated ... At least the bits we use.
*
*
* Maintainer : Sylvain Munaut <tnt@246tNt.com>
*
* Some of the code has been inspired/copied from the 2.4 code written
* by Dale Farnsworth <dfarnsworth@mvista.com>.
*
* Copyright (C) 2004-2005 Sylvain Munaut <tnt@246tNt.com>
* Copyright (C) 2003 MontaVista, Software, Inc.
*
* This file is licensed under the terms of the GNU General Public License
* version 2. This program is licensed "as is" without any warranty of any
* kind, whether express or implied.
*/
/* Platform device Usage :
*
* Since PSCs can have multiple function, the correct driver for each one
* is selected by calling mpc52xx_match_psc_function(...). The function
* handled by this driver is "uart".
*
* The driver init all necessary registers to place the PSC in uart mode without
* DCD. However, the pin multiplexing aren't changed and should be set either
* by the bootloader or in the platform init code.
*
* The idx field must be equal to the PSC index ( e.g. 0 for PSC1, 1 for PSC2,
* and so on). So the PSC1 is mapped to /dev/ttyPSC0, PSC2 to /dev/ttyPSC1 and
* so on. But be warned, it's an ABSOLUTE REQUIREMENT ! This is needed mainly
* fpr the console code : without this 1:1 mapping, at early boot time, when we
* are parsing the kernel args console=ttyPSC?, we wouldn't know wich PSC it
* will be mapped to.
*/
#include <linux/config.h>
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/tty.h>
#include <linux/serial.h>
#include <linux/sysrq.h>
#include <linux/console.h>
#include <asm/delay.h>
#include <asm/io.h>
#include <asm/mpc52xx.h>
#include <asm/mpc52xx_psc.h>
#if defined(CONFIG_SERIAL_MPC52xx_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#include <linux/serial_core.h>
/* We've been assigned a range on the "Low-density serial ports" major */
#define SERIAL_PSC_MAJOR 204
#define SERIAL_PSC_MINOR 148
#define ISR_PASS_LIMIT 256 /* Max number of iteration in the interrupt */
static struct uart_port mpc52xx_uart_ports[MPC52xx_PSC_MAXNUM];
/* Rem: - We use the read_status_mask as a shadow of
* psc->mpc52xx_psc_imr
* - It's important that is array is all zero on start as we
* use it to know if it's initialized or not ! If it's not sure
* it's cleared, then a memset(...,0,...) should be added to
* the console_init
*/
#define PSC(port) ((struct mpc52xx_psc __iomem *)((port)->membase))
/* Forward declaration of the interruption handling routine */
static irqreturn_t mpc52xx_uart_int(int irq,void *dev_id,struct pt_regs *regs);
/* Simple macro to test if a port is console or not. This one is taken
* for serial_core.c and maybe should be moved to serial_core.h ? */
#ifdef CONFIG_SERIAL_CORE_CONSOLE
#define uart_console(port) ((port)->cons && (port)->cons->index == (port)->line)
#else
#define uart_console(port) (0)
#endif
/* ======================================================================== */
/* UART operations */
/* ======================================================================== */
static unsigned int
mpc52xx_uart_tx_empty(struct uart_port *port)
{
int status = in_be16(&PSC(port)->mpc52xx_psc_status);
return (status & MPC52xx_PSC_SR_TXEMP) ? TIOCSER_TEMT : 0;
}
static void
mpc52xx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
/* Not implemented */
}
static unsigned int
mpc52xx_uart_get_mctrl(struct uart_port *port)
{
/* Not implemented */
return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
}
static void
mpc52xx_uart_stop_tx(struct uart_port *port)
{
/* port->lock taken by caller */
port->read_status_mask &= ~MPC52xx_PSC_IMR_TXRDY;
out_be16(&PSC(port)->mpc52xx_psc_imr,port->read_status_mask);
}
static void
mpc52xx_uart_start_tx(struct uart_port *port)
{
/* port->lock taken by caller */
port->read_status_mask |= MPC52xx_PSC_IMR_TXRDY;
out_be16(&PSC(port)->mpc52xx_psc_imr,port->read_status_mask);
}
static void
mpc52xx_uart_send_xchar(struct uart_port *port, char ch)
{
unsigned long flags;
spin_lock_irqsave(&port->lock, flags);
port->x_char = ch;
if (ch) {
/* Make sure tx interrupts are on */
/* Truly necessary ??? They should be anyway */
port->read_status_mask |= MPC52xx_PSC_IMR_TXRDY;
out_be16(&PSC(port)->mpc52xx_psc_imr,port->read_status_mask);
}
spin_unlock_irqrestore(&port->lock, flags);
}
static void
mpc52xx_uart_stop_rx(struct uart_port *port)
{
/* port->lock taken by caller */
port->read_status_mask &= ~MPC52xx_PSC_IMR_RXRDY;
out_be16(&PSC(port)->mpc52xx_psc_imr,port->read_status_mask);
}
static void
mpc52xx_uart_enable_ms(struct uart_port *port)
{
/* Not implemented */
}
static void
mpc52xx_uart_break_ctl(struct uart_port *port, int ctl)
{
unsigned long flags;
spin_lock_irqsave(&port->lock, flags);
if ( ctl == -1 )
out_8(&PSC(port)->command,MPC52xx_PSC_START_BRK);
else
out_8(&PSC(port)->command,MPC52xx_PSC_STOP_BRK);
spin_unlock_irqrestore(&port->lock, flags);
}
static int
mpc52xx_uart_startup(struct uart_port *port)
{
struct mpc52xx_psc __iomem *psc = PSC(port);
int ret;
/* Request IRQ */
ret = request_irq(port->irq, mpc52xx_uart_int,
SA_INTERRUPT | SA_SAMPLE_RANDOM, "mpc52xx_psc_uart", port);
if (ret)
return ret;
/* Reset/activate the port, clear and enable interrupts */
out_8(&psc->command,MPC52xx_PSC_RST_RX);
out_8(&psc->command,MPC52xx_PSC_RST_TX);
out_be32(&psc->sicr,0); /* UART mode DCD ignored */
out_be16(&psc->mpc52xx_psc_clock_select, 0xdd00); /* /16 prescaler on */
out_8(&psc->rfcntl, 0x00);
out_be16(&psc->rfalarm, 0x1ff);
out_8(&psc->tfcntl, 0x07);
out_be16(&psc->tfalarm, 0x80);
port->read_status_mask |= MPC52xx_PSC_IMR_RXRDY | MPC52xx_PSC_IMR_TXRDY;
out_be16(&psc->mpc52xx_psc_imr,port->read_status_mask);
out_8(&psc->command,MPC52xx_PSC_TX_ENABLE);
out_8(&psc->command,MPC52xx_PSC_RX_ENABLE);
return 0;
}
static void
mpc52xx_uart_shutdown(struct uart_port *port)
{
struct mpc52xx_psc __iomem *psc = PSC(port);
/* Shut down the port, interrupt and all */
out_8(&psc->command,MPC52xx_PSC_RST_RX);
out_8(&psc->command,MPC52xx_PSC_RST_TX);
port->read_status_mask = 0;
out_be16(&psc->mpc52xx_psc_imr,port->read_status_mask);
/* Release interrupt */
free_irq(port->irq, port);
}
static void
mpc52xx_uart_set_termios(struct uart_port *port, struct termios *new,
struct termios *old)
{
struct mpc52xx_psc __iomem *psc = PSC(port);
unsigned long flags;
unsigned char mr1, mr2;
unsigned short ctr;
unsigned int j, baud, quot;
/* Prepare what we're gonna write */
mr1 = 0;
switch (new->c_cflag & CSIZE) {
case CS5: mr1 |= MPC52xx_PSC_MODE_5_BITS;
break;
case CS6: mr1 |= MPC52xx_PSC_MODE_6_BITS;
break;
case CS7: mr1 |= MPC52xx_PSC_MODE_7_BITS;
break;
case CS8:
default: mr1 |= MPC52xx_PSC_MODE_8_BITS;
}
if (new->c_cflag & PARENB) {
mr1 |= (new->c_cflag & PARODD) ?
MPC52xx_PSC_MODE_PARODD : MPC52xx_PSC_MODE_PAREVEN;
} else
mr1 |= MPC52xx_PSC_MODE_PARNONE;
mr2 = 0;
if (new->c_cflag & CSTOPB)
mr2 |= MPC52xx_PSC_MODE_TWO_STOP;
else
mr2 |= ((new->c_cflag & CSIZE) == CS5) ?
MPC52xx_PSC_MODE_ONE_STOP_5_BITS :
MPC52xx_PSC_MODE_ONE_STOP;
baud = uart_get_baud_rate(port, new, old, 0, port->uartclk/16);
quot = uart_get_divisor(port, baud);
ctr = quot & 0xffff;
/* Get the lock */
spin_lock_irqsave(&port->lock, flags);
/* Update the per-port timeout */
uart_update_timeout(port, new->c_cflag, baud);
/* Do our best to flush TX & RX, so we don't loose anything */
/* But we don't wait indefinitly ! */
j = 5000000; /* Maximum wait */
/* FIXME Can't receive chars since set_termios might be called at early
* boot for the console, all stuff is not yet ready to receive at that
* time and that just makes the kernel oops */
/* while (j-- && mpc52xx_uart_int_rx_chars(port)); */
while (!(in_be16(&psc->mpc52xx_psc_status) & MPC52xx_PSC_SR_TXEMP) &&
--j)
udelay(1);
if (!j)
printk( KERN_ERR "mpc52xx_uart.c: "
"Unable to flush RX & TX fifos in-time in set_termios."
"Some chars may have been lost.\n" );
/* Reset the TX & RX */
out_8(&psc->command,MPC52xx_PSC_RST_RX);
out_8(&psc->command,MPC52xx_PSC_RST_TX);
/* Send new mode settings */
out_8(&psc->command,MPC52xx_PSC_SEL_MODE_REG_1);
out_8(&psc->mode,mr1);
out_8(&psc->mode,mr2);
out_8(&psc->ctur,ctr >> 8);
out_8(&psc->ctlr,ctr & 0xff);
/* Reenable TX & RX */
out_8(&psc->command,MPC52xx_PSC_TX_ENABLE);
out_8(&psc->command,MPC52xx_PSC_RX_ENABLE);
/* We're all set, release the lock */
spin_unlock_irqrestore(&port->lock, flags);
}
static const char *
mpc52xx_uart_type(struct uart_port *port)
{
return port->type == PORT_MPC52xx ? "MPC52xx PSC" : NULL;
}
static void
mpc52xx_uart_release_port(struct uart_port *port)
{
if (port->flags & UPF_IOREMAP) { /* remapped by us ? */
iounmap(port->membase);
port->membase = NULL;
}
release_mem_region(port->mapbase, MPC52xx_PSC_SIZE);
}
static int
mpc52xx_uart_request_port(struct uart_port *port)
{
if (port->flags & UPF_IOREMAP) /* Need to remap ? */
port->membase = ioremap(port->mapbase, MPC52xx_PSC_SIZE);
if (!port->membase)
return -EINVAL;
return request_mem_region(port->mapbase, MPC52xx_PSC_SIZE,
"mpc52xx_psc_uart") != NULL ? 0 : -EBUSY;
}
static void
mpc52xx_uart_config_port(struct uart_port *port, int flags)
{
if ( (flags & UART_CONFIG_TYPE) &&
(mpc52xx_uart_request_port(port) == 0) )
port->type = PORT_MPC52xx;
}
static int
mpc52xx_uart_verify_port(struct uart_port *port, struct serial_struct *ser)
{
if ( ser->type != PORT_UNKNOWN && ser->type != PORT_MPC52xx )
return -EINVAL;
if ( (ser->irq != port->irq) ||
(ser->io_type != SERIAL_IO_MEM) ||
(ser->baud_base != port->uartclk) ||
(ser->iomem_base != (void*)port->mapbase) ||
(ser->hub6 != 0 ) )
return -EINVAL;
return 0;
}
static struct uart_ops mpc52xx_uart_ops = {
.tx_empty = mpc52xx_uart_tx_empty,
.set_mctrl = mpc52xx_uart_set_mctrl,
.get_mctrl = mpc52xx_uart_get_mctrl,
.stop_tx = mpc52xx_uart_stop_tx,
.start_tx = mpc52xx_uart_start_tx,
.send_xchar = mpc52xx_uart_send_xchar,
.stop_rx = mpc52xx_uart_stop_rx,
.enable_ms = mpc52xx_uart_enable_ms,
.break_ctl = mpc52xx_uart_break_ctl,
.startup = mpc52xx_uart_startup,
.shutdown = mpc52xx_uart_shutdown,
.set_termios = mpc52xx_uart_set_termios,
/* .pm = mpc52xx_uart_pm, Not supported yet */
/* .set_wake = mpc52xx_uart_set_wake, Not supported yet */
.type = mpc52xx_uart_type,
.release_port = mpc52xx_uart_release_port,
.request_port = mpc52xx_uart_request_port,
.config_port = mpc52xx_uart_config_port,
.verify_port = mpc52xx_uart_verify_port
};
/* ======================================================================== */
/* Interrupt handling */
/* ======================================================================== */
static inline int
mpc52xx_uart_int_rx_chars(struct uart_port *port, struct pt_regs *regs)
{
struct tty_struct *tty = port->info->tty;
unsigned char ch, flag;
unsigned short status;
/* While we can read, do so ! */
while ( (status = in_be16(&PSC(port)->mpc52xx_psc_status)) &
MPC52xx_PSC_SR_RXRDY) {
/* Get the char */
ch = in_8(&PSC(port)->mpc52xx_psc_buffer_8);
/* Handle sysreq char */
#ifdef SUPPORT_SYSRQ
if (uart_handle_sysrq_char(port, ch, regs)) {
port->sysrq = 0;
continue;
}
#endif
/* Store it */
flag = TTY_NORMAL;
port->icount.rx++;
if ( status & (MPC52xx_PSC_SR_PE |
MPC52xx_PSC_SR_FE |
MPC52xx_PSC_SR_RB) ) {
if (status & MPC52xx_PSC_SR_RB) {
flag = TTY_BREAK;
uart_handle_break(port);
} else if (status & MPC52xx_PSC_SR_PE)
flag = TTY_PARITY;
else if (status & MPC52xx_PSC_SR_FE)
flag = TTY_FRAME;
/* Clear error condition */
out_8(&PSC(port)->command,MPC52xx_PSC_RST_ERR_STAT);
}
tty_insert_flip_char(tty, ch, flag);
if (status & MPC52xx_PSC_SR_OE) {
/*
* Overrun is special, since it's
* reported immediately, and doesn't
* affect the current character
*/
tty_insert_flip_char(tty, 0, TTY_OVERRUN);
}
}
tty_flip_buffer_push(tty);
return in_be16(&PSC(port)->mpc52xx_psc_status) & MPC52xx_PSC_SR_RXRDY;
}
static inline int
mpc52xx_uart_int_tx_chars(struct uart_port *port)
{
struct circ_buf *xmit = &port->info->xmit;
/* Process out of band chars */
if (port->x_char) {
out_8(&PSC(port)->mpc52xx_psc_buffer_8, port->x_char);
port->icount.tx++;
port->x_char = 0;
return 1;
}
/* Nothing to do ? */
if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
mpc52xx_uart_stop_tx(port);
return 0;
}
/* Send chars */
while (in_be16(&PSC(port)->mpc52xx_psc_status) & MPC52xx_PSC_SR_TXRDY) {
out_8(&PSC(port)->mpc52xx_psc_buffer_8, xmit->buf[xmit->tail]);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
port->icount.tx++;
if (uart_circ_empty(xmit))
break;
}
/* Wake up */
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
/* Maybe we're done after all */
if (uart_circ_empty(xmit)) {
mpc52xx_uart_stop_tx(port);
return 0;
}
return 1;
}
static irqreturn_t
mpc52xx_uart_int(int irq, void *dev_id, struct pt_regs *regs)
{
struct uart_port *port = (struct uart_port *) dev_id;
unsigned long pass = ISR_PASS_LIMIT;
unsigned int keepgoing;
unsigned short status;
if ( irq != port->irq ) {
printk( KERN_WARNING
"mpc52xx_uart_int : " \
"Received wrong int %d. Waiting for %d\n",
irq, port->irq);
return IRQ_NONE;
}
spin_lock(&port->lock);
/* While we have stuff to do, we continue */
do {
/* If we don't find anything to do, we stop */
keepgoing = 0;
/* Read status */
status = in_be16(&PSC(port)->mpc52xx_psc_isr);
status &= port->read_status_mask;
/* Do we need to receive chars ? */
/* For this RX interrupts must be on and some chars waiting */
if ( status & MPC52xx_PSC_IMR_RXRDY )
keepgoing |= mpc52xx_uart_int_rx_chars(port, regs);
/* Do we need to send chars ? */
/* For this, TX must be ready and TX interrupt enabled */
if ( status & MPC52xx_PSC_IMR_TXRDY )
keepgoing |= mpc52xx_uart_int_tx_chars(port);
/* Limit number of iteration */
if ( !(--pass) )
keepgoing = 0;
} while (keepgoing);
spin_unlock(&port->lock);
return IRQ_HANDLED;
}
/* ======================================================================== */
/* Console ( if applicable ) */
/* ======================================================================== */
#ifdef CONFIG_SERIAL_MPC52xx_CONSOLE
static void __init
mpc52xx_console_get_options(struct uart_port *port,
int *baud, int *parity, int *bits, int *flow)
{
struct mpc52xx_psc __iomem *psc = PSC(port);
unsigned char mr1;
/* Read the mode registers */
out_8(&psc->command,MPC52xx_PSC_SEL_MODE_REG_1);
mr1 = in_8(&psc->mode);
/* CT{U,L}R are write-only ! */
*baud = __res.bi_baudrate ?
__res.bi_baudrate : CONFIG_SERIAL_MPC52xx_CONSOLE_BAUD;
/* Parse them */
switch (mr1 & MPC52xx_PSC_MODE_BITS_MASK) {
case MPC52xx_PSC_MODE_5_BITS: *bits = 5; break;
case MPC52xx_PSC_MODE_6_BITS: *bits = 6; break;
case MPC52xx_PSC_MODE_7_BITS: *bits = 7; break;
case MPC52xx_PSC_MODE_8_BITS:
default: *bits = 8;
}
if (mr1 & MPC52xx_PSC_MODE_PARNONE)
*parity = 'n';
else
*parity = mr1 & MPC52xx_PSC_MODE_PARODD ? 'o' : 'e';
}
static void
mpc52xx_console_write(struct console *co, const char *s, unsigned int count)
{
struct uart_port *port = &mpc52xx_uart_ports[co->index];
struct mpc52xx_psc __iomem *psc = PSC(port);
unsigned int i, j;
/* Disable interrupts */
out_be16(&psc->mpc52xx_psc_imr, 0);
/* Wait the TX buffer to be empty */
j = 5000000; /* Maximum wait */
while (!(in_be16(&psc->mpc52xx_psc_status) & MPC52xx_PSC_SR_TXEMP) &&
--j)
udelay(1);
/* Write all the chars */
for ( i=0 ; i<count ; i++ ) {
/* Send the char */
out_8(&psc->mpc52xx_psc_buffer_8, *s);
/* Line return handling */
if ( *s++ == '\n' )
out_8(&psc->mpc52xx_psc_buffer_8, '\r');
/* Wait the TX buffer to be empty */
j = 20000; /* Maximum wait */
while (!(in_be16(&psc->mpc52xx_psc_status) &
MPC52xx_PSC_SR_TXEMP) && --j)
udelay(1);
}
/* Restore interrupt state */
out_be16(&psc->mpc52xx_psc_imr, port->read_status_mask);
}
static int __init
mpc52xx_console_setup(struct console *co, char *options)
{
struct uart_port *port = &mpc52xx_uart_ports[co->index];
int baud = CONFIG_SERIAL_MPC52xx_CONSOLE_BAUD;
int bits = 8;
int parity = 'n';
int flow = 'n';
if (co->index < 0 || co->index >= MPC52xx_PSC_MAXNUM)
return -EINVAL;
/* Basic port init. Needed since we use some uart_??? func before
* real init for early access */
spin_lock_init(&port->lock);
port->uartclk = __res.bi_ipbfreq / 2; /* Look at CTLR doc */
port->ops = &mpc52xx_uart_ops;
port->mapbase = MPC52xx_PA(MPC52xx_PSCx_OFFSET(co->index+1));
/* We ioremap ourself */
port->membase = ioremap(port->mapbase, MPC52xx_PSC_SIZE);
if (port->membase == NULL)
return -EINVAL;
/* Setup the port parameters accoding to options */
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
else
mpc52xx_console_get_options(port, &baud, &parity, &bits, &flow);
return uart_set_options(port, co, baud, parity, bits, flow);
}
static struct uart_driver mpc52xx_uart_driver;
static struct console mpc52xx_console = {
.name = "ttyPSC",
.write = mpc52xx_console_write,
.device = uart_console_device,
.setup = mpc52xx_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1, /* Specified on the cmdline (e.g. console=ttyPSC0 ) */
.data = &mpc52xx_uart_driver,
};
static int __init
mpc52xx_console_init(void)
{
register_console(&mpc52xx_console);
return 0;
}
console_initcall(mpc52xx_console_init);
#define MPC52xx_PSC_CONSOLE &mpc52xx_console
#else
#define MPC52xx_PSC_CONSOLE NULL
#endif
/* ======================================================================== */
/* UART Driver */
/* ======================================================================== */
static struct uart_driver mpc52xx_uart_driver = {
.owner = THIS_MODULE,
.driver_name = "mpc52xx_psc_uart",
.dev_name = "ttyPSC",
.devfs_name = "ttyPSC",
.major = SERIAL_PSC_MAJOR,
.minor = SERIAL_PSC_MINOR,
.nr = MPC52xx_PSC_MAXNUM,
.cons = MPC52xx_PSC_CONSOLE,
};
/* ======================================================================== */
/* Platform Driver */
/* ======================================================================== */
static int __devinit
mpc52xx_uart_probe(struct platform_device *dev)
{
struct resource *res = dev->resource;
struct uart_port *port = NULL;
int i, idx, ret;
/* Check validity & presence */
idx = dev->id;
if (idx < 0 || idx >= MPC52xx_PSC_MAXNUM)
return -EINVAL;
if (!mpc52xx_match_psc_function(idx,"uart"))
return -ENODEV;
/* Init the port structure */
port = &mpc52xx_uart_ports[idx];
memset(port, 0x00, sizeof(struct uart_port));
spin_lock_init(&port->lock);
port->uartclk = __res.bi_ipbfreq / 2; /* Look at CTLR doc */
port->fifosize = 255; /* Should be 512 ! But it can't be */
/* stored in a unsigned char */
port->iotype = UPIO_MEM;
port->flags = UPF_BOOT_AUTOCONF |
( uart_console(port) ? 0 : UPF_IOREMAP );
port->line = idx;
port->ops = &mpc52xx_uart_ops;
/* Search for IRQ and mapbase */
for (i=0 ; i<dev->num_resources ; i++, res++) {
if (res->flags & IORESOURCE_MEM)
port->mapbase = res->start;
else if (res->flags & IORESOURCE_IRQ)
port->irq = res->start;
}
if (!port->irq || !port->mapbase)
return -EINVAL;
/* Add the port to the uart sub-system */
ret = uart_add_one_port(&mpc52xx_uart_driver, port);
if (!ret)
platform_set_drvdata(dev, (void*)port);
return ret;
}
static int
mpc52xx_uart_remove(struct platform_device *dev)
{
struct uart_port *port = (struct uart_port *) platform_get_drvdata(dev);
platform_set_drvdata(dev, NULL);
if (port)
uart_remove_one_port(&mpc52xx_uart_driver, port);
return 0;
}
#ifdef CONFIG_PM
static int
mpc52xx_uart_suspend(struct platform_device *dev, pm_message_t state)
{
struct uart_port *port = (struct uart_port *) platform_get_drvdata(dev);
if (sport)
uart_suspend_port(&mpc52xx_uart_driver, port);
return 0;
}
static int
mpc52xx_uart_resume(struct platform_device *dev)
{
struct uart_port *port = (struct uart_port *) platform_get_drvdata(dev);
if (port)
uart_resume_port(&mpc52xx_uart_driver, port);
return 0;
}
#endif
static struct platform_driver mpc52xx_uart_platform_driver = {
.probe = mpc52xx_uart_probe,
.remove = mpc52xx_uart_remove,
#ifdef CONFIG_PM
.suspend = mpc52xx_uart_suspend,
.resume = mpc52xx_uart_resume,
#endif
.driver = {
.name = "mpc52xx-psc",
},
};
/* ======================================================================== */
/* Module */
/* ======================================================================== */
static int __init
mpc52xx_uart_init(void)
{
int ret;
printk(KERN_INFO "Serial: MPC52xx PSC driver\n");
ret = uart_register_driver(&mpc52xx_uart_driver);
if (ret == 0) {
ret = platform_driver_register(&mpc52xx_uart_platform_driver);
if (ret)
uart_unregister_driver(&mpc52xx_uart_driver);
}
return ret;
}
static void __exit
mpc52xx_uart_exit(void)
{
platform_driver_unregister(&mpc52xx_uart_platform_driver);
uart_unregister_driver(&mpc52xx_uart_driver);
}
module_init(mpc52xx_uart_init);
module_exit(mpc52xx_uart_exit);
MODULE_AUTHOR("Sylvain Munaut <tnt@246tNt.com>");
MODULE_DESCRIPTION("Freescale MPC52xx PSC UART");
MODULE_LICENSE("GPL");
View Git Blame Copy Permalink