path: root/drivers/serial/sn_console.c

/*
 * 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) 2004-2005 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.
 *
 */
stati