/*
* C-Brick Serial Port (and console) driver for SGI Altix machines.
*
* This driver is NOT suitable for talking to the l1-controller for
* anything other than 'console activities' --- please use the l1
* driver for that.
*
*
* Copyright (c) 2004-2006 Silicon Graphics, Inc. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of version 2 of the GNU General Public License
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
* Further, this software is distributed without any warranty that it is
* free of the rightful claim of any third person regarding infringement
* or the like. Any license provided herein, whether implied or
* otherwise, applies only to this software file. Patent licenses, if
* any, provided herein do not apply to combinations of this program with
* other software, or any other product whatsoever.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
*
* Contact information: Silicon Graphics, Inc., 1500 Crittenden Lane,
* Mountain View, CA 94043, or:
*
* http://www.sgi.com
*
* For further information regarding this notice, see:
*
* http://oss.sgi.com/projects/GenInfo/NoticeExplan
*/
#include <linux/config.h>
#include <linux/interrupt.h>
#include <linux/tty.h>
#include <linux/serial.h>
#include <linux/console.h>
#include <linux/module.h>
#include <linux/sysrq.h>
#include <linux/circ_buf.h>
#include <linux/serial_reg.h>
#include <linux/delay.h> /* for mdelay */
#include <linux/miscdevice.h>
#include <linux/serial_core.h>
#include <asm/io.h>
#include <asm/sn/simulator.h>
#include <asm/sn/sn_sal.h>
/* number of characters we can transmit to the SAL console at a time */
#define SN_SAL_MAX_CHARS 120
/* 64K, when we're asynch, it must be at least printk's LOG_BUF_LEN to
* avoid losing chars, (always has to be a power of 2) */
#define SN_SAL_BUFFER_SIZE (64 * (1 << 10))
#define SN_SAL_UART_FIFO_DEPTH 16
#define SN_SAL_UART_FIFO_SPEED_CPS 9600/10
/* sn_transmit_chars() calling args */
#define TRANSMIT_BUFFERED 0
#define TRANSMIT_RAW 1
/* To use dynamic numbers only and not use the assigned major and minor,
* define the following.. */
/* #define USE_DYNAMIC_MINOR 1 *//* use dynamic minor number */
#define USE_DYNAMIC_MINOR 0 /* Don't rely on misc_register dynamic minor */
/* Device name we're using */
#define DEVICE_NAME "ttySG"
#define DEVICE_NAME_DYNAMIC "ttySG0" /* need full name for misc_register */
/* The major/minor we are using, ignored for USE_DYNAMIC_MINOR */
#define DEVICE_MAJOR 204
#define DEVICE_MINOR 40
#ifdef CONFIG_MAGIC_SYSRQ
static char sysrq_serial_str[] = "\eSYS";
static char *sysrq_serial_ptr = sysrq_serial_str;
static unsigned long sysrq_requested;
#endif /* CONFIG_MAGIC_SYSRQ */
/*
* Port definition - this kinda drives it all
*/
struct sn_cons_port {
struct timer_list sc_timer;
struct uart_port sc_port;
struct sn_sal_ops {
int (*sal_puts_raw) (const char *s, int len);
int (*sal_puts) (const char *s, int len);
int (*sal_getc) (void);
int (*sal_input_pending) (void);
void (*sal_wakeup_transmit) (struct sn_cons_port *, int);
} *sc_ops;
unsigned long sc_interrupt_timeout;
int sc_is_asynch;
};
static struct sn_cons_port sal_console_port;
static int sn_process_input;
/* Only used if USE_DYNAMIC_MINOR is set to 1 */
static struct miscdevice misc; /* used with misc_register for dynamic */
extern void early_sn_setup(void);
#undef DEBUG
#ifdef DEBUG
static int sn_debug_printf(const char *fmt, ...);
#define DPRINTF(x...) sn_debug_printf(x)
#else
#define DPRINTF(x...) do { } while (0)
#endif
/* Prototypes */
static int snt_hw_puts_raw(const char *, int);
static int snt_hw_puts_buffered(const char *, int);
static int snt_poll_getc(void);
static int snt_poll_input_pending(void);
static int snt_intr_getc(void);
static int snt_intr_input_pending(void);
static void sn_transmit_chars(struct sn_cons_port *, int);
/* A table for polling:
*/
static struct sn_sal_ops poll_ops = {
.sal_puts_raw = snt_hw_puts_raw,
.sal_puts = snt_hw_puts_raw,
.sal_getc = snt_poll_getc,
.sal_input_pending = snt_poll_input_pending
};
/* A table for interrupts enabled */
static struct sn_sal_ops intr_ops = {
.sal_puts_raw = snt_hw_puts_raw,
.sal_puts = snt_hw_puts_buffered,
.sal_getc = snt_intr_getc,
.sal_input_pending = snt_intr_input_pending,
.sal_wakeup_transmit = sn_transmit_chars
};
/* the console does output in two distinctly different ways:
* synchronous (raw) and asynchronous (buffered). initally, early_printk
* does synchronous output. any data written goes directly to the SAL
* to be output (incidentally, it is internally buffered by the SAL)
* after interrupts and timers are initialized and available for use,
* the console init code switches to asynchronous output. this is
* also the earliest opportunity to begin polling for console input.
* after console initialization, console output and tty (serial port)
* output is buffered and sent to the SAL asynchronously (either by
* timer callback or by UART interrupt) */
/* routines for running the console in polling mode */
/**
* snt_poll_getc - Get a character from the console in polling mode
*
*/
static int snt_poll_getc(void)
{
int ch;
ia64_sn_console_getc(&ch);
return ch;
}
/**
* snt_poll_input_pending - Check if any input is waiting - polling mode.
*
*/
static int snt_poll_input_pending(void)
{
int status, input;
status = ia64_sn_console_check(&input);
return !status && input;
}
/* routines for an interrupt driven console (normal) */
/**
* snt_intr_getc - Get a character from the console, interrupt mode
*
*/
static int snt_intr_getc(void)
{
return ia64_sn_console_readc();
}
/**
* snt_intr_input_pending - Check if input is pending, interrupt mode
*
*/
static int snt_intr_input_pending(void)
{
return ia64_sn_console_intr_status() & SAL_CONSOLE_INTR_RECV;
}
/* these functions are polled and interrupt */
/**
* snt_hw_puts_raw - Send raw string to the console, polled or interrupt mode
* @s: String
* @len: Length
*
*/
static int snt_hw_puts_raw(const char *s, int len)
{
/* this will call the PROM and not return until this is done */
return ia64_sn_console_putb(s, len);
}
/**
* snt_hw_puts_buffered - Send string to console, polled or interrupt mode
* @s: String
* @len: Length
*
*/
static int snt_hw_puts_buffered(const char *s, int len)
{
/* queue data to the PROM */
return ia64_sn_console_xmit_chars((char *)s, len);
}
/* uart interface structs
* These functions are associated with the uart_port that the serial core
* infrastructure calls.
*
* Note: Due to how the console works, many routines are no-ops.
*/
/**
* snp_type - What type of console are we?
* @port: Port to operate with (we ignore since we only have one port)
*
*/
static const char *snp_type(struct uart_port *port)
{
return ("SGI SN L1");
}
/**
* snp_tx_empty - Is the transmitter empty? We pretend we're always empty
* @port: Port to operate on (we ignore since we only have one port)
*
*/
static unsigned int snp_tx_empty(struct uart_port *port)
{
return 1;
}
/**
* snp_stop_tx - stop the transmitter - no-op for us
* @port: Port to operat eon - we ignore - no-op function
*
*/
static void snp_stop_tx(struct uart_port *port)
{
}
/**
* snp_release_port - Free i/o and resources for port - no-op for us
* @port: Port to operate on - we ignore - no-op function
*
*/
static void snp_release_port(struct uart_port *port)
{
}
/**
* snp_enable_ms - Force modem status interrupts on - no-op for us
* @port: Port to operate on - we ignore - no-op function
*
*/
static void snp_enable_ms(struct uart_port *port)
{
}
/**
* snp_shutdown - shut down the port - free irq and disable - no-op for us
* @port: Port to shut down - we ignore
*
*/
static void snp_shutdown(struct uart_port *port)
{
}
/**
* snp_set_mctrl - set control lines (dtr, rts, etc) - no-op for our console
* @port: Port to operate on - we ignore
* @mctrl: Lines to set/unset - we ignore
*
*/
static void snp_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
}
/**
* snp_get_mctrl - get contorl line info, we just return a static value
* @port: port to operate on - we only have one port so we ignore this
*
*/
static unsigned int snp_get_mctrl(struct uart_port *port)
{
return TIOCM_CAR | TIOCM_RNG | TIOCM_DSR | TIOCM_CTS;
}
/**
* snp_stop_rx - Stop the receiver - we ignor ethis
* @port: Port to operate on - we ignore
*
*/
static void snp_stop_rx(struct uart_port *port)
{
}
/**
* snp_start_tx - Start transmitter
* @port: Port to operate on
*
*/
static void snp_start_tx(struct uart_port *port)
{
if (sal_console_port.sc_ops->sal_wakeup_transmit)
sal_console_port.sc_ops->sal_wakeup_transmit(&sal_console_port,
TRANSMIT_BUFFERED);
}
/**
* snp_break_ctl - handle breaks - ignored by us
* @port: Port to operate on
* @break_state: Break state
*
*/
static void snp_break_ctl(struct uart_port *port, int break_state)
{
}
/**
* snp_startup - Start up the serial port - always return 0 (We're always on)
* @port: Port to operate on
*
*/
static int snp_startup(struct uart_port *port)
{
return 0;
}
/**
* snp_set_termios - set termios stuff - we ignore these
* @port: port to operate on
* @termios: New settings
* @termios: Old
*
*/
static void
snp_set_termios(struct uart_port *port, struct termios *termios,
struct termios *old)
{
}
/**
* snp_request_port - allocate resources for port - ignored by us
* @port: port to operate on
*
*/
static int snp_request_port(struct uart_port *port)
{
return 0;
}
/**
* snp_config_port - allocate resources, set up - we ignore, we're always on
* @port: Port to operate on
* @flags: flags used for port setup
*
*/
static void snp_config_port(struct uart_port *port, int flags)
{
}
/* Associate the uart functions above - given to serial core */
static struct uart_ops sn_console_ops = {
.tx_empty = snp_tx_empty,
.set_mctrl = snp_set_mctrl,
.get_mctrl = snp_get_mctrl,
.stop_tx = snp_stop_tx,
.start_tx = snp_start_tx,
.stop_rx = snp_stop_rx,
.enable_ms = snp_enable_ms,
.break_ctl = snp_break_ctl,
.startup = snp_startup,
.shutdown = snp_shutdown,
.set_termios = snp_set_termios,
.pm = NULL,
.type = snp_type,
.release_port = snp_release_port,
.request_port = snp_request_port,
.config_port = snp_config_port,
.verify_port = NULL,
};
/* End of uart struct functions and defines */
#ifdef DEBUG
/**
* sn_debug_printf - close to hardware debugging printf
* @fmt: printf format
*
* This is as "close to the metal" as we can get, used when the driver
* itself may be broken.
*
*/
static int sn_debug_printf(const char *fmt, ...)
{
static char printk_buf[1024];
int printed_len;
va_list args;
va_start(args, fmt);
printed_len = vsnprintf(printk_buf, sizeof(printk_buf), fmt, args);
if (!sal_console_port.sc_ops) {
sal_console_port.sc_ops = &poll_ops;
early_sn_setup();
}
sal_console_port.sc_ops->sal_puts_raw(printk_buf, printed_len);
va_end(args);
return printed_len;
}
#endif /* DEBUG */
/*
* Interrupt handling routines.
*/
/**
* sn_receive_chars - Grab characters, pass them to tty layer
* @port: Port to operate on
* @regs: Saved registers (needed by uart_handle_sysrq_char)
* @flags: irq flags
*
* Note: If we're not registered with the serial core infrastructure yet,
* we don't try to send characters to it...
*
*/
static void
sn_receive_chars(struct sn_cons_port *port, struct pt_regs *regs,
unsigned long flags)
{
int ch;
struct tty_struct *tty;
if (!port) {
printk(KERN_ERR "sn_receive_chars - port NULL so can't receieve\n");
return;
}
if (!port->sc_ops) {
printk(KERN_ERR "sn_receive_chars - port->sc_ops NULL so can't receieve\n");
return;
}
if (port->sc_port.info) {
/* The serial_core stuffs are initilized, use them */
tty = port->sc_port.info->tty;
}
else {
/* Not registered yet - can't pass to tty layer. */
tty = NULL;
}
while (port->sc_ops->sal_input_pending()) {
ch = port->sc_ops->sal_getc();
if (ch < 0) {
printk(KERN_ERR "sn_console: An error occured while "
"obtaining data from the console (0x%0x)\n", ch);
break;
}
#ifdef CONFIG_MAGIC_SYSRQ
if (sysrq_requested) {
unsigned long sysrq_timeout = sysrq_requested + HZ*5;
sysrq_requested = 0;
if (ch && time_before(jiffies, sysrq_timeout)) {
spin_unlock_irqrestore(&port->sc_port.lock, flags);
handle_sysrq(ch, regs, NULL);
spin_lock_irqsave(&port->sc_port.lock, flags);
/* ignore actual sysrq command char */
continue;
}
}
if (ch == *sysrq_serial_ptr) {
if (!(*++sysrq_serial_ptr)) {
sysrq_requested = jiffies;
sysrq_serial_ptr = sysrq_serial_str;
}
/*
* ignore the whole sysrq string except for the
* leading escape
*/
if (ch != '\e')
continue;
}
else
sysrq_serial_ptr = sysrq_serial_str;
#endif /* CONFIG_MAGIC_SYSRQ */
/* record the character to pass up to the tty layer */
if (tty) {
if(tty_insert_flip_char(tty, ch, TTY_NORMAL) == 0)
break;
}
port->sc_port.icount.rx++;
}
if (tty)
tty_flip_buffer_push(tty);
}
/**
* sn_transmit_chars - grab characters from serial core, send off
* @port: Port to operate on
* @raw: Transmit raw or buffered
*
* Note: If we're early, before we're registered with serial core, the
* writes are going through sn_sal_console_write because that's how
* register_console has been set up. We currently could have asynch
* polls calling this function due to sn_sal_switch_to_asynch but we can
* ignore them until we register with the serial core stuffs.
*
*/
static void sn_transmit_chars(struct sn_cons_port *port, int raw)
{
int xmit_count, tail, head, loops, ii;
int result;
char *start;
struct circ_buf *xmit;
if (!port)
return;
BUG_ON(!port->sc_is_asynch);
if (port->sc_port.info) {
/* We're initilized, using serial core infrastructure */
xmit = &port->sc_port.info->xmit;
} else {
/* Probably sn_sal_switch_to_asynch has been run but serial core isn't
* initilized yet. Just return. Writes are going through
* sn_sal_console_write (due to register_console) at this time.
*/
return;
}
if (uart_circ_empty(xmit) || uart_tx_stopped(&port->sc_port)) {
/* Nothing to do. */
ia64_sn_console_intr_disable(SAL_CONSOLE_INTR_XMIT);
return;
}
head = xmit->head;
tail = xmit->tail;
start = &xmit->buf[tail];
/* twice around gets the tail to the end of the buffer and
* then to the head, if needed */
loops = (head < tail) ? 2 : 1;
for (ii = 0; ii < loops; ii++) {
xmit_count = (head < tail) ?
(UART_XMIT_SIZE - tail) : (head - tail);
if (xmit_count > 0) {
if (raw == TRANSMIT_RAW)
result =
port->sc_ops->sal_puts_raw(start,
xmit_count);
else
result =
port->sc_ops->sal_puts(start, xmit_count);
#ifdef DEBUG
if (!result)
DPRINTF("`");
#endif
if (result > 0) {
xmit_count -= result;
port->sc_port.icount.tx += result;
tail += result;
tail &= UART_XMIT_SIZE - 1;
xmit->tail = tail;
start = &xmit->buf[tail];
}
}
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&port->sc_port);
if (uart_circ_empty(xmit))
snp_stop_tx(&port->sc_port); /* no-op for us */
}
/**
* sn_sal_interrupt - Handle console interrupts
* @irq: irq #, useful for debug statements
* @dev_id: our pointer to our port (sn_cons_port which contains the uart port)
* @regs: Saved registers, used by sn_receive_chars for uart_handle_sysrq_char
*
*/
static irqreturn_t sn_sal_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
struct sn_cons_port *port = (struct sn_cons_port *)dev_id;
unsigned long flags;
int status = ia64_sn_console_intr_status();
if (!port)
return IRQ_NONE;
spin_lock_irqsave(&port->sc_port.lock, flags);
if (status & SAL_CONSOLE_INTR_RECV) {
sn_receive_chars(port, regs, flags);
}
if (status & SAL_CONSOLE_INTR_XMIT) {
sn_transmit_chars(port, TRANSMIT_BUFFERED);
}
spin_unlock_irqrestore(&port->sc_port.lock, flags);
return IRQ_HANDLED;
}
/**
* sn_sal_connect_interrupt - Request interrupt, handled by sn_sal_interrupt
* @port: Our sn_cons_port (which contains the uart port)
*
* returns the console irq if interrupt is successfully registered, else 0
*
*/
static int sn_sal_connect_interrupt(struct sn_cons_port *port)
{
if (request_irq(SGI_UART_VECTOR, sn_sal_interrupt,
SA_INTERRUPT | SA_SHIRQ,
"SAL console driver", port) >= 0) {
return SGI_UART_VECTOR;
}
printk(KERN_INFO "sn_console: console proceeding in polled mode\n");
return 0;
}
/**
* sn_sal_timer_poll - this function handles polled console mode
* @data: A pointer to our sn_cons_port (which contains the uart port)
*
* data is the pointer that init_timer will store for us. This function is
* associated with init_timer to see if there is any console traffic.
* Obviously not used in interrupt mode
*
*/
static void sn_sal_timer_poll(unsigned long data)
{
struct sn_cons_port *port = (struct sn_cons_port *)data;
unsigned long flags;
if (!port)
return;
if (!port->sc_port.irq) {
spin_lock_irqsave(&port->sc_port.lock, flags);
if (sn_process_input)
sn_receive_chars(port, NULL, flags);
sn_transmit_chars(port, TRANSMIT_RAW);
spin_unlock_irqrestore(&port->sc_port.lock, flags);
mod_timer(&port->sc_timer,
jiffies + port->sc_interrupt_timeout);
}
}
/*
* Boot-time initialization code
*/
/**
* sn_sal_switch_to_asynch - Switch to async mode (as opposed to synch)
* @port: Our sn_cons_port (which contains the uart port)
*
* So this is used by sn_sal_serial_console_init (early on, before we're
* registered with serial core). It's also used by sn_sal_module_init
* right after we've registered with serial core. The later only happens
* if we didn't already come through here via sn_sal_serial_console_init.
*
*/
static void __init sn_sal_switch_to_asynch(struct sn_cons_port *port)
{
unsigned long flags;
if (!port)
return;
DPRINTF("sn_console: about to switch to asynchronous console\n");
/* without early_printk, we may be invoked late enough to race
* with other cpus doing console IO at this point, however
* console interrupts will never be enabled */
spin_lock_irqsave(&port->sc_port.lock, flags);
/* early_printk invocation may have done this for us */
if (!port->sc_ops)
port->sc_ops = &poll_ops;
/* we can't turn on the console interrupt (as request_irq
* calls kmalloc, which isn't set up yet), so we rely on a
* timer to poll for input and push data from the console
* buffer.
*/
init_timer(&port->sc_timer);
port->sc_timer.function = sn_sal_timer_poll;
port->sc_timer.data = (unsigned long)port;
if (IS_RUNNING_ON_SIMULATOR())
port->sc_interrupt_timeout = 6;
else {
/* 960cps / 16 char FIFO = 60HZ
* HZ / (SN_SAL_FIFO_SPEED_CPS / SN_SAL_FIFO_DEPTH) */
port->sc_interrupt_timeout =
HZ * SN_SAL_UART_FIFO_DEPTH / SN_SAL_UART_FIFO_SPEED_CPS;
}
mod_timer(&port->sc_timer, jiffies + port->sc_interrupt_timeout);
port->sc_is_asynch = 1;
spin_unlock_irqrestore(&port->sc_port.lock, flags);
}
/**
* sn_sal_switch_to_interrupts - Switch to interrupt driven mode
* @port: Our sn_cons_port (which contains the uart port)
*
* In sn_sal_module_init, after we're registered with serial core and
* the port is added, this function is called to switch us to interrupt
* mode. We were previously in asynch/polling mode (using init_timer).
*
* We attempt to switch to interrupt mode here by calling
* sn_sal_connect_interrupt. If that works out, we enable receive interrupts.
*/
static void __init sn_sal_switch_to_interrupts(struct sn_cons_port *port)
{
int irq;
unsigned long flags;
if (!port)
return;
DPRINTF("sn_console: switching to interrupt driven console\n");
spin_lock_irqsave(&port->sc_port.lock, flags);
irq = sn_sal_connect_interrupt(port);
if (irq) {
port->sc_port.irq = irq;
port->sc_ops = &intr_ops;
/* turn on receive interrupts */
ia64_sn_console_intr_enable(SAL_CONSOLE_INTR_RECV);
}
spin_unlock_irqrestore(&port->sc_port.lock, flags);
}
/*
* Kernel console definitions
*/
static void sn_sal_console_write(struct console *, const char *, unsigned);
static int __init sn_sal_console_setup(struct console *, char *);
static struct uart_driver sal_console_uart;
extern struct tty_driver *uart_console_device(struct console *, int *);
static struct console sal_console = {
.name = DEVICE_NAME,
.write = sn_sal_console_write,
.device = uart_console_device,
.setup = sn_sal_console_setup,
.index = -1, /* unspecified */
.data = &sal_console_uart,
};
#define SAL_CONSOLE &sal_console
static struct uart_driver sal_console_uart = {
.owner = THIS_MODULE,
.driver_name = "sn_console",
.dev_name = DEVICE_NAME,
.major = 0, /* major/minor set at registration time per USE_DYNAMIC_MINOR */
.minor = 0,
.nr = 1, /* one port */
.cons = SAL_CONSOLE,
};
/**
* sn_sal_module_init - When the kernel loads us, get us rolling w/ serial core
*
* Before this is called, we've been printing kernel messages in a special
* early mode not making use of the serial core infrastructure. When our
* driver is loaded for real, we register the driver and port with serial
* core and try to enable interrupt driven mode.
*
*/
static int __init sn_sal_module_init(void)
{
int retval;
if (!ia64_platform_is("sn2"))
return -ENODEV;
printk(KERN_INFO "sn_console: Console driver init\n");
if (USE_DYNAMIC_MINOR == 1) {
misc.minor = MISC_DYNAMIC_MINOR;
misc.name = DEVICE_NAME_DYNAMIC;
retval = misc_register(&misc);
if (retval != 0) {
printk(KERN_WARNING "Failed to register console "
"device using misc_register.\n");
return -ENODEV;
}
sal_console_uart.major = MISC_MAJOR;
sal_console_uart.minor = misc.minor;
} else {
sal_console_uart.major = DEVICE_MAJOR;
sal_console_uart.minor = DEVICE_MINOR;
}
/* We register the driver and the port before switching to interrupts
* or async above so the proper uart structures are populated */
if (uart_register_driver(&sal_console_uart) < 0) {
printk
("ERROR sn_sal_module_init failed uart_register_driver, line %d\n",
__LINE__);
return -ENODEV;
}
spin_lock_init(&sal_console_port.sc_port.lock);
/* Setup the port struct with the minimum needed */
sal_console_port.sc_port.membase = (char *)1; /* just needs to be non-zero */
sal_console_port.sc_port.type = PORT_16550A;
sal_console_port.sc_port.fifosize = SN_SAL_MAX_CHARS;
sal_console_port.sc_port.ops = &sn_console_ops;
sal_console_port.sc_port.line = 0;
if (uart_add_one_port(&sal_console_uart, &sal_console_port.sc_port) < 0) {
/* error - not sure what I'd do - so I'll do nothing */
printk(KERN_ERR "%s: unable to add port\n", __FUNCTION__);
}
/* when this driver is compiled in, the console initialization
* will have already switched us into asynchronous operation
* before we get here through the module initcalls */
if (!sal_console_port.sc_is_asynch) {
sn_sal_switch_to_asynch(&sal_console_port);
}
/* at this point (module_init) we can try to turn on interrupts */
if (!IS_RUNNING_ON_SIMULATOR()) {
sn_sal_switch_to_interrupts(&sal_console_port);
}
sn_process_input = 1;
return 0;
}
/**
* sn_sal_module_exit - When we're unloaded, remove the driver/port
*
*/
static void __exit sn_sal_module_exit(void)
{
del_timer_sync(&sal_console_port.sc_timer);
uart_remove_one_port(&sal_console_uart, &sal_console_port.sc_port);
uart_unregister_driver(&sal_console_uart);
misc_deregister(&misc);
}
module_init(sn_sal_module_init);
module_exit(sn_sal_module_exit);
/**
* puts_raw_fixed - sn_sal_console_write helper for adding \r's as required
* @puts_raw : puts function to do the writing
* @s: input string
* @count: length
*
* We need a \r ahead of every \n for direct writes through
* ia64_sn_console_putb (what sal_puts_raw below actually does).
*
*/
static void puts_raw_fixed(int (*puts_raw) (const char *s, int len),
const char *s, int count)
{
const char *s1;
/* Output '\r' before each '\n' */
while ((s1 = memchr(s, '\n', count)) != NULL) {
puts_raw(s, s1 - s);
puts_raw("\r\n", 2);
count -= s1 + 1 - s;
s = s1 + 1;
}
puts_raw(s, count);
}
/**
* sn_sal_console_write - Print statements before serial core available
* @console: Console to operate on - we ignore since we have just one
* @s: String to send
* @count: length
*
* This is referenced in the console struct. It is used for early
* console printing before we register with serial core and for things
* such as kdb. The console_lock must be held when we get here.
*
* This function has some code for trying to print output even if the lock
* is held. We try to cover the case where a lock holder could have died.
* We don't use this special case code if we're not registered with serial
* core yet. After we're registered with serial core, the only time this
* function would be used is for high level kernel output like magic sys req,
* kdb, and printk's.
*/
static void
sn_sal_console_write(struct console *co, const char *s, unsigned count)
{
unsigned long flags = 0;
struct sn_cons_port *port = &sal_console_port;
static int stole_lock = 0;
BUG_ON(!port->sc_is_asynch);
/* We can't look at the xmit buffer if we're not registered with serial core
* yet. So only do the fancy recovery after registering
*/
if (!port->sc_port.info) {
/* Not yet registered with serial core - simple case */
puts_raw_fixed(port->sc_ops->sal_puts_raw, s, count);
return;
}
/* somebody really wants this output, might be an
* oops, kdb, panic, etc. make sure they get it. */
if (spin_is_locked(&port->sc_port.lock)) {
int lhead = port->sc_port.info->xmit.head;
int ltail = port->sc_port.info->xmit.tail;
int counter, got_lock = 0;
/*
* We attempt to determine if someone has died with the
* lock. We wait ~20 secs after the head and tail ptrs
* stop moving and assume the lock holder is not functional
* and plow ahead. If the lock is freed within the time out
* period we re-get the lock and go ahead normally. We also
* remember if we have plowed ahead so that we don't have
* to wait out the time out period again - the asumption
* is that we will time out again.
*/
for (counter = 0; counter < 150; mdelay(125), counter++) {
if (!spin_is_locked(&port->sc_port.lock)
|| stole_lock) {
if (!stole_lock) {
spin_lock_irqsave(&port->sc_port.lock,
flags);
got_lock = 1;
}
break;
} else {
/* still locked */
if ((lhead != port->sc_port.info->xmit.head)
|| (ltail !=
port->sc_port.info->xmit.tail)) {
lhead =
port->sc_port.info->xmit.head;
ltail =
port->sc_port.info->xmit.tail;
counter = 0;
}
}
}
/* flush anything in the serial core xmit buffer, raw */
sn_transmit_chars(port, 1);
if (got_lock) {
spin_unlock_irqrestore(&port->sc_port.lock, flags);
stole_lock = 0;
} else {
/* fell thru */
stole_lock = 1;
}
puts_raw_fixed(port->sc_ops->sal_puts_raw, s, count);
} else {
stole_lock = 0;
spin_lock_irqsave(&port->sc_port.lock, flags);
sn_transmit_chars(port, 1);
spin_unlock_irqrestore(&port->sc_port.lock, flags);
puts_raw_fixed(port->sc_ops->sal_puts_raw, s, count);
}
}
/**
* sn_sal_console_setup - Set up console for early printing
* @co: Console to work with
* @options: Options to set
*
* Altix console doesn't do anything with baud rates, etc, anyway.
*
* This isn't required since not providing the setup function in the
* console struct is ok. However, other patches like KDB plop something
* here so providing it is easier.
*
*/
static int __init sn_sal_console_setup(struct console *co, char *options)
{
return 0;
}
/**
* sn_sal_console_write_early - simple early output routine
* @co - console struct
* @s - string to print
* @count - count
*
* Simple function to provide early output, before even
* sn_sal_serial_console_init is called. Referenced in the
* console struct registerd in sn_serial_console_early_setup.
*
*/
static void __init
sn_sal_console_write_early(struct console *co, const char *s, unsigned count)
{
puts_raw_fixed(sal_console_port.sc_ops->sal_puts_raw, s, count);
}
/* Used for very early console printing - again, before
* sn_sal_serial_console_init is run */
static struct console sal_console_early __initdata = {
.name = "sn_sal",
.write = sn_sal_console_write_early,
.flags = CON_PRINTBUFFER,
.index = -1,
};
/**
* sn_serial_console_early_setup - Sets up early console output support
*
* Register a console early on... This is for output before even
* sn_sal_serial_cosnole_init is called. This function is called from
* setup.c. This allows us to do really early polled writes. When
* sn_sal_serial_console_init is called, this console is unregistered
* and a new one registered.
*/
int __init sn_serial_console_early_setup(void)
{
if (!ia64_platform_is("sn2"))
return -1;
sal_console_port.sc_ops = &poll_ops;
spin_lock_init(&sal_console_port.sc_port.lock);
early_sn_setup(); /* Find SAL entry points */
register_console(&sal_console_early);
return 0;
}
/**
* sn_sal_serial_console_init - Early console output - set up for register
*
* This function is called when regular console init happens. Because we
* support even earlier console output with sn_serial_console_early_setup
* (called from setup.c directly), this function unregisters the really
* early console.
*
* Note: Even if setup.c doesn't register sal_console_early, unregistering
* it here doesn't hurt anything.
*
*/
static int __init sn_sal_serial_console_init(void)
{
if (ia64_platform_is("sn2")) {
sn_sal_switch_to_asynch(&sal_console_port);
DPRINTF("sn_sal_serial_console_init : register console\n");
register_console(&sal_console);
unregister_console(&sal_console_early);
}
return 0;
}
console_initcall(sn_sal_serial_console_init);
