uart.c

microwindows移植到S3C44B0的源码

/*
 *  UART driver for 68360 CPM SCC or SMC
 *  Copyright (c) 2000 D. Jeff Dionne <[e-mail]>,
 *  Copyright (c) 2000 Michael Leslie <[e-mail]>
 *  Copyright (c) 1997 Dan Malek <[e-mail]>
 *
 * I used the serial.c driver as the framework for this driver.
 * Give credit to those guys.
 * The original code was written for the MBX860 board.  I tried to make
 * it generic, but there may be some assumptions in the structures that
 * have to be fixed later.
 * To save porting time, I did not bother to change any object names
 * that are not accessed outside of this file.
 * It still needs lots of work........When it was easy, I included code
 * to support the SCCs, but this has never been tested, nor is it complete.
 * Only the SCCs support modem control, so that is not complete either.
 *
 * This module exports the following rs232 io functions:
 *
 *	int rs_360_init(void);
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial.h>
#include <linux/serialP.h> 
#include <linux/major.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/ptrace.h>
#include <linux/mm.h>
#include <linux/malloc.h>
/* #include <linux/init.h> */
#include <linux/delay.h>
/* #include <asm/uaccess.h> */
#include <asm/irq.h>

#include <linux/compatmac.h>

#include <asm/m68360.h>
/* #include <asm/360_immap.h> */ /* more hierarchical than m68360_quicc.h */
#include "commproc.h"

 
#ifdef CONFIG_KGDB
extern void breakpoint(void);
extern void set_debug_traps(void);
extern int  kgdb_output_string (const char* s, unsigned int count);
#endif


/* #ifdef CONFIG_SERIAL_CONSOLE */ /* This seems to be a post 2.0 thing - mles */
#include <linux/console.h>

/* this defines the index into rs_table for the port to use
 */
#ifndef CONFIG_SERIAL_CONSOLE_PORT
#define CONFIG_SERIAL_CONSOLE_PORT	1 /* ie SMC2 - note USE_SMC2 must be defined */
#endif
/* #endif */

#if 0
/* SCC2 for console
 */
#undef CONFIG_SERIAL_CONSOLE_PORT
#define CONFIG_SERIAL_CONSOLE_PORT	2
#endif


#define TX_WAKEUP	ASYNC_SHARE_IRQ

static char *serial_name = "CPM UART driver";
static char *serial_version = "0.03";

static DECLARE_TASK_QUEUE(tq_serial);

static struct tty_driver serial_driver, callout_driver;
static int serial_refcount;
int serial_console_setup(struct console *co, char *options);

/*
 * Serial driver configuration section.  Here are the various options:
 */
#define SERIAL_PARANOIA_CHECK
#define CONFIG_SERIAL_NOPAUSE_IO
#define SERIAL_DO_RESTART

/* Set of debugging defines */

#undef SERIAL_DEBUG_INTR
#undef SERIAL_DEBUG_OPEN
#undef SERIAL_DEBUG_FLOW
#undef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT

#define _INLINE_ inline
  
#define DBG_CNT(s)

/* We overload some of the items in the data structure to meet our
 * needs.  For example, the port address is the CPM parameter ram
 * offset for the SCC or SMC.  The maximum number of ports is 4 SCCs and
 * 2 SMCs.  The "hub6" field is used to indicate the channel number, with
 * a flag indicating SCC or SMC, and the number is used as an index into
 * the CPM parameter area for this device.
 * The "type" field is currently set to 0, for PORT_UNKNOWN.  It is
 * not currently used.  I should probably use it to indicate the port
 * type of SMC or SCC.
 * The SMCs do not support any modem control signals.
 */
#define smc_scc_num	hub6
#define NUM_IS_SCC	((int)0x00010000)
#define PORT_NUM(P)	((P) & 0x0000ffff)


#if defined (CONFIG_UCQUICC)

volatile extern void *_periph_base;
/* sipex transceiver
 *   mode bits for       are on pins
 *
 *    SCC2                d16..19
 *    SCC3                d20..23
 *    SCC4                d24..27
 */
#define SIPEX_MODE(n,m) ((m & 0x0f)<<(16+4*(n-1)))

static uint sipex_mode_bits = 0x00000000;

#endif

/* There is no `serial_state' defined back here in 2.0.
 * Try to get by with serial_struct
 */
/* #define serial_state serial_struct */

/* 2.4 -> 2.0 portability problem: async_icount in 2.4 has a few
 * extras: */

#if 0
struct async_icount_24 {
	__u32   cts, dsr, rng, dcd, tx, rx;
	__u32   frame, parity, overrun, brk;
	__u32   buf_overrun;
} icount;
#endif

#if 0

struct serial_state {
        int     magic;
        int     baud_base;
        unsigned long   port;
        int     irq;
        int     flags;
        int     hub6;
        int     type;
        int     line;
        int     revision;       /* Chip revision (950) */
        int     xmit_fifo_size;
        int     custom_divisor;
        int     count;
        u8      *iomem_base;
        u16     iomem_reg_shift;
        unsigned short  close_delay;
        unsigned short  closing_wait; /* time to wait before closing */
        struct async_icount_24     icount; 
        struct termios          normal_termios;
        struct termios          callout_termios;
        int     io_type;
        struct async_struct *info;
};
#endif

#define SSTATE_MAGIC 0x5302



/* SMC2 is sometimes used for low performance TDM interfaces.  Define
 * this as 1 if you want SMC2 as a serial port UART managed by this driver.
 * Define this as 0 if you wish to use SMC2 for something else.
 */
#define USE_SMC2 1

#if 0
/* Define SCC to ttySx mapping. */
#define SCC_NUM_BASE	(USE_SMC2 + 1)	/* SCC base tty "number" */

/* Define which SCC is the first one to use for a serial port.  These
 * are 0-based numbers, i.e. this assumes the first SCC (SCC1) is used
 * for Ethernet, and the first available SCC for serial UART is SCC2.
 * NOTE:  IF YOU CHANGE THIS, you have to change the PROFF_xxx and
 * interrupt vectors in the table below to match.
 */
#define SCC_IDX_BASE	1	/* table index */
#endif


/* Processors other than the 860 only get SMCs configured by default.
 * Either they don't have SCCs or they are allocated somewhere else.
 * Of course, there are now 860s without some SCCs, so we will need to
 * address that someday.
 * The Embedded Planet Multimedia I/O cards use TDM interfaces to the
 * stereo codec parts, and we use SMC2 to help support that.
 */
static struct serial_state rs_table[] = {
/*  type   line   PORT           IRQ       FLAGS  smc_scc_num (F.K.A. hub6) */
	{  0,     0, PRSLOT_SMC1, CPMVEC_SMC1,   0,    0 }    /* SMC1 ttyS0 */
#if USE_SMC2
	,{ 0,     0, PRSLOT_SMC2, CPMVEC_SMC2,   0,    1 }     /* SMC2 ttyS1 */
#endif

#if defined(CONFIG_M68360_SCC_UART)
	,{ 0,     0, PRSLOT_SCC2, CPMVEC_SCC2,   0, (NUM_IS_SCC | 1) }    /* SCC2 ttyS2 */
	,{ 0,     0, PRSLOT_SCC3, CPMVEC_SCC3,   0, (NUM_IS_SCC | 2) }    /* SCC3 ttyS3 */
	,{ 0,     0, PRSLOT_SCC4, CPMVEC_SCC4,   0, (NUM_IS_SCC | 3) }    /* SCC4 ttyS4 */
#endif
};

#define NR_PORTS	(sizeof(rs_table)/sizeof(struct serial_state))

static struct tty_struct *serial_table[NR_PORTS];
static struct termios *serial_termios[NR_PORTS];
static struct termios *serial_termios_locked[NR_PORTS];

/* The number of buffer descriptors and their sizes.
 */
#define RX_NUM_FIFO	4
#define RX_BUF_SIZE	32
#define TX_NUM_FIFO	4
#define TX_BUF_SIZE	32

#define CONSOLE_NUM_FIFO 2
#define CONSOLE_BUF_SIZE 4

char *console_fifos[CONSOLE_NUM_FIFO * CONSOLE_BUF_SIZE];

#ifndef MIN
#define MIN(a,b)	((a) < (b) ? (a) : (b))
#endif

/* The async_struct in serial.h does not really give us what we
 * need, so define our own here.
 */
typedef struct serial_info {
	int			magic;
	int			flags;

	struct serial_state		*state;
 	/* struct serial_struct	*state; */
 	/* struct async_struct	*state; */
	
	struct tty_struct 	*tty;
	int			read_status_mask;
	int			ignore_status_mask;
	int			timeout;
	int			line;
	int			x_char;	/* xon/xoff character */
	int			close_delay;
	unsigned short		closing_wait;
	unsigned short		closing_wait2;
	unsigned long		event;
	unsigned long		last_active;
	int			blocked_open; /* # of blocked opens */
	long			session; /* Session of opening process */
	long			pgrp; /* pgrp of opening process */
	struct tq_struct	tqueue;
	struct tq_struct	tqueue_hangup;
 	wait_queue_head_t	open_wait; 
 	wait_queue_head_t	close_wait; 
/*	struct wait_queue     *open_wait; */
/*	struct wait_queue	   *close_wait;i */

	
/* CPM Buffer Descriptor pointers.
	*/
	QUICC_BD			*rx_bd_base;
	QUICC_BD			*rx_cur;
	QUICC_BD			*tx_bd_base;
	QUICC_BD			*tx_cur;
} ser_info_t;


/* since kmalloc_init() does not get called until much after this initialization: */
static ser_info_t  quicc_ser_info[NR_PORTS];
static char rx_buf_pool[NR_PORTS * RX_NUM_FIFO * RX_BUF_SIZE];
static char tx_buf_pool[NR_PORTS * TX_NUM_FIFO * TX_BUF_SIZE];

static void change_speed(ser_info_t *info);
static void rs_360_wait_until_sent(struct tty_struct *tty, int timeout);

static inline int serial_paranoia_check(ser_info_t *info,
					kdev_t device, const char *routine)
{
#ifdef SERIAL_PARANOIA_CHECK
	static const char *badmagic =
		"Warning: bad magic number for serial struct (%s) in %s\n";
	static const char *badinfo =
		"Warning: null async_struct for (%s) in %s\n";

	if (!info) {
		printk(badinfo, kdevname(device), routine);
		return 1;
	}
	if (info->magic != SERIAL_MAGIC) {
		printk(badmagic, kdevname(device), routine);
		return 1;
	}
#endif
	return 0;
}

/*
 * This is used to figure out the divisor speeds and the timeouts,
 * indexed by the termio value.  The generic CPM functions are responsible
 * for setting and assigning baud rate generators for us.
 */
static int baud_table[] = {
	0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
	9600, 19200, 38400, 57600, 115200, 230400, 460800, 0 };

/* This sucks. There is a better way: */
#if defined(CONFIG_CONSOLE_9600)
  #define CONSOLE_BAUDRATE 9600
#elif defined(CONFIG_CONSOLE_19200)
  #define CONSOLE_BAUDRATE 19200
#elif defined(CONFIG_CONSOLE_115200)
  #define CONSOLE_BAUDRATE 115200
#else
#error "console baud rate undefined"
#endif

/*
 * ------------------------------------------------------------
 * rs_stop() and rs_start()
 *
 * This routines are called before setting or resetting tty->stopped.
 * They enable or disable transmitter interrupts, as necessary.
 * ------------------------------------------------------------
 */
static void rs_360_stop(struct tty_struct *tty)
{
	ser_info_t *info = (ser_info_t *)tty->driver_data;
	int	idx;
	unsigned long flags;
 	volatile struct scc_regs *sccp;
 	volatile struct smc_regs *smcp;

	if (serial_paranoia_check(info, tty->device, "rs_stop"))
		return;
	
	save_flags(flags); cli();
	idx = PORT_NUM(info->state->smc_scc_num);
	if (info->state->smc_scc_num & NUM_IS_SCC) {
		sccp = &pquicc->scc_regs[idx];
		sccp->scc_sccm &= ~UART_SCCM_TX;
	} else {
		/* smcp = &cpmp->cp_smc[idx]; */
		smcp = &pquicc->smc_regs[idx];
		smcp->smc_smcm &= ~SMCM_TX;
	}
	restore_flags(flags);
}


static void rs_360_start(struct tty_struct *tty)
{
	ser_info_t *info = (ser_info_t *)tty->driver_data;
	int	idx;
	unsigned long flags;
	volatile struct scc_regs *sccp;
	volatile struct smc_regs *smcp;

	if (serial_paranoia_check(info, tty->device, "rs_stop"))
		return;
	
	save_flags(flags); cli();
	idx = PORT_NUM(info->state->smc_scc_num);
	if (info->state->smc_scc_num & NUM_IS_SCC) {
		sccp = &pquicc->scc_regs[idx];
		sccp->scc_sccm |= UART_SCCM_TX;
	} else {
		smcp = &pquicc->smc_regs[idx];
		smcp->smc_smcm |= SMCM_TX;
	}
	restore_flags(flags);
}

/*
 * ----------------------------------------------------------------------
 *
 * Here starts the interrupt handling routines.  All of the following
 * subroutines are declared as inline and are folded into
 * rs_interrupt().  They were separated out for readability's sake.
 *
 * Note: rs_interrupt() is a "fast" interrupt, which means that it
 * runs with interrupts turned off.  People who may want to modify
 * rs_interrupt() should try to keep the interrupt handler as fast as
 * possible.  After you are done making modifications, it is not a bad
 * idea to do:
 * 
 * gcc -S -DKERNEL -Wall -Wstrict-prototypes -O6 -fomit-frame-pointer serial.c
 *
 * and look at the resulting assemble code in serial.s.
 *
 * 				- Ted Ts'o ([e-mail]), 7-Mar-93
 * -----------------------------------------------------------------------
 */

/*
 * This routine is used by the interrupt handler to schedule
 * processing in the software interrupt portion of the driver.
 */
static _INLINE_ void rs_sched_event(ser_info_t *info,
				  int event)
{
	info->event |= 1 << event;
	queue_task(&info->tqueue, &tq_serial);
	mark_bh(SERIAL_BH);
}

static _INLINE_ void receive_chars(ser_info_t *info)
{
	struct tty_struct *tty = info->tty;
	unsigned char ch, *cp;
	/*int	ignored = 0;*/
	int	i;
	ushort	status;
	 struct	async_icount *icount; 
	/* struct	async_icount_24 *icount; */
	volatile QUICC_BD	*bdp;

	icount = &info->state->icount;

	/* Just loop through the closed BDs and copy the characters into
	 * the buffer.
	 */
	bdp = info->rx_cur;
	for (;;) {
		if (bdp->status & BD_SC_EMPTY)	/* If this one is empty */
			break;			/*   we are all done */

		/* The read status mask tell us what we should do with
		 * incoming characters, especially if errors occur.
		 * One special case is the use of BD_SC_EMPTY.  If
		 * this is not set, we are supposed to be ignoring
		 * inputs.  In this case, just mark the buffer empty and
		 * continue.
		 */
		if (!(info->read_status_mask & BD_SC_EMPTY)) {
			bdp->status |= BD_SC_EMPTY;
			bdp->status &=
				~(BD_SC_BR | BD_SC_FR | BD_SC_PR | BD_SC_OV);

			if (bdp->status & BD_SC_WRAP)
				bdp = info->rx_bd_base;
			else
				bdp++;
			continue;
		}

		/* Get the number of characters and the buffer pointer.
		*/
		i = bdp->length;
		/* cp = (unsigned char *)__va(bdp->buf); */
		cp = (char *)bdp->buf;
		status = bdp->status;

		/* Check to see if there is room in the tty buffer for
		 * the characters in our BD buffer.  If not, we exit
		 * now, leaving the BD with the characters.  We'll pick
		 * them up again on the next receive interrupt (which could
		 * be a timeout).
		 */
		if ((tty->flip.count + i) >= TTY_FLIPBUF_SIZE)
			break;

		while (i-- > 0) {
			ch = *cp++;
			*tty->flip.char_buf_ptr = ch;
			icount->rx++;

#ifdef SERIAL_DEBUG_INTR
			printk("DR%02x:%02x...", ch, status);
#endif
			*tty->flip.flag_buf_ptr = 0;
			if (status & (BD_SC_BR | BD_SC_FR |
				       BD_SC_PR | BD_SC_OV)) {
				/*
				 * For statistics only
				 */
				if (status & BD_SC_BR)
					icount->brk++;
				else if (status & BD_SC_PR)
					icount->parity++;
				else if (status & BD_SC_FR)
					icount->frame++;
				if (status & BD_SC_OV)
					icount->overrun++;

				/*
				 * Now check to see if character should be
				 * ignored, and mask off conditions which
				 * should be ignored.
				if (status & info->ignore_status_mask) {
					if (++ignored > 100)
						break;
					continue;
				}
				 */
				status &= info->read_status_mask;
		
				if (status & (BD_SC_BR)) {
#ifdef SERIAL_DEBUG_INTR
					printk("handling break....");
#endif