ser_a2232.c

linux和2410结合开发 用他可以生成2410所需的zImage文件

/* drivers/char/ser_a2232.c */

/* $Id: ser_a2232.c,v 0.4 2000/01/25 12:00:00 ehaase Exp $ */

/* Linux serial driver for the Amiga A2232 board */

/* This driver is MAINTAINED. Before applying any changes, please contact
 * the author.
 */

/* Copyright (c) 2000-2001 Enver Haase    <[e-mail]>
 *                   alias The A2232 driver project <[e-mail]>
 * All rights reserved.
 *
 *   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.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */
/***************************** Documentation ************************/
/*
 * This driver is in EXPERIMENTAL state. That means I could not find
 * someone with five A2232 boards with 35 ports running at 19200 bps
 * at the same time and test the machine's behaviour.
 * However, I know that you can performance-tweak this driver (see
 * the source code).
 * One thing to consider is the time this driver consumes during the
 * Amiga's vertical blank interrupt. Everything that is to be done
 * _IS DONE_ when entering the vertical blank interrupt handler of
 * this driver.
 * However, it would be more sane to only do the job for only ONE card
 * instead of ALL cards at a time; or, more generally, to handle only
 * SOME ports instead of ALL ports at a time.
 * However, as long as no-one runs into problems I guess I shouldn't
 * change the driver as it runs fine for me :) .
 *
 * Version history of this file:
 * 0.4	Resolved licensing issues.
 * 0.3	Inclusion in the Linux/m68k tree, small fixes.
 * 0.2	Added documentation, minor typo fixes.
 * 0.1	Initial release.
 *
 * TO DO:
 * -	Handle incoming BREAK events. I guess "Stevens: Advanced
 *	Programming in the UNIX(R) Environment" is a good reference
 *	on what is to be done.
 * -	When installing as a module, don't simply 'printk' text, but
 *	send it to the TTY used by the user.
 *
 * THANKS TO:
 * -	Jukka Marin (65EC02 code).
 * -	The other NetBSD developers on whose A2232 driver I had a
 *	pretty close look. However, I didn't copy any code so it
 *	is okay to put my code under the GPL and include it into
 *	Linux.
 */
/***************************** End of Documentation *****************/

/***************************** Defines ******************************/
/*
 * Enables experimental 115200 (normal) 230400 (turbo) baud rate.
 * The A2232 specification states it can only operate at speeds up to
 * 19200 bits per second, and I was not able to send a file via
 * "sz"/"rz" and a null-modem cable from one A2232 port to another
 * at 115200 bits per second.
 * However, this might work for you.
 */
#undef A2232_SPEEDHACK
/*
 * Default is not to use RTS/CTS so you could be talked to death.
 */
#define A2232_SUPPRESS_RTSCTS_WARNING
/************************* End of Defines ***************************/

/***************************** Includes *****************************/
#include <linux/module.h>

#include <linux/types.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/errno.h>

#include <asm/setup.h>
#include <asm/amigaints.h>
#include <asm/amigahw.h>
#include <linux/zorro.h>
#include <asm/irq.h>
#include <asm/semaphore.h>

#include <linux/delay.h>

#include <linux/serial.h>
#include <linux/generic_serial.h>

#include "ser_a2232.h"
#include "ser_a2232fw.h"
/************************* End of Includes **************************/

/***************************** Prototypes ***************************/
/* Helper functions */
static __inline__ volatile struct a2232status *a2232stat(unsigned int board,
						unsigned int portonboard);
static __inline__ volatile struct a2232memory *a2232mem (unsigned int board); 
static __inline__ void a2232_receive_char(	struct a2232_port *port,
						int ch, int err );
/* The interrupt service routine */
static void a2232_vbl_inter(int irq, void *data, struct pt_regs *fp);
/* Initialize the port structures */
static void a2232_init_portstructs(void);
/* Initialize and register TTY drivers. */
/* returns 0 IFF successful */
static int a2232_init_drivers(void); 
/* Initialize all A2232 boards; main entry point. */
int a2232board_init(void);

/* BEGIN GENERIC_SERIAL PROTOTYPES */
static void a2232_disable_tx_interrupts(void *ptr);
static void a2232_enable_tx_interrupts(void *ptr);
static void a2232_disable_rx_interrupts(void *ptr);
static void a2232_enable_rx_interrupts(void *ptr);
static int  a2232_get_CD(void *ptr);
static void a2232_shutdown_port(void *ptr);
static int  a2232_set_real_termios(void *ptr);
static int  a2232_chars_in_buffer(void *ptr);
static void a2232_close(void *ptr);
static void a2232_hungup(void *ptr);
/* static void a2232_getserial (void *ptr, struct serial_struct *sp); */
/* END GENERIC_SERIAL PROTOTYPES */

/* Functions that the TTY driver struct expects */
static int  a2232_ioctl(struct tty_struct *tty, struct file *file,
										unsigned int cmd, unsigned long arg);
static void a2232_throttle(struct tty_struct *tty);
static void a2232_unthrottle(struct tty_struct *tty);
static int  a2232_open(struct tty_struct * tty, struct file * filp);
/************************* End of Prototypes ************************/

/***************************** Global variables *********************/
/*---------------------------------------------------------------------------
 * Interface from generic_serial.c back here
 *--------------------------------------------------------------------------*/
static struct real_driver a2232_real_driver = {
        a2232_disable_tx_interrupts,
        a2232_enable_tx_interrupts,
        a2232_disable_rx_interrupts,
        a2232_enable_rx_interrupts,
        a2232_get_CD,
        a2232_shutdown_port,
        a2232_set_real_termios,
        a2232_chars_in_buffer,
        a2232_close,
        a2232_hungup,
	NULL	/* a2232_getserial */
};

static void *a2232_driver_ID = &a2232_driver_ID; // Some memory address WE own.

/* Ports structs */
static struct a2232_port a2232_ports[MAX_A2232_BOARDS*NUMLINES];

/* TTY driver structs */
static struct tty_driver a2232_driver;
static struct tty_driver a2232_callout_driver;

/* Variables used by the TTY driver */
static int a2232_refcount;
static struct tty_struct *a2232_table[MAX_A2232_BOARDS*NUMLINES] = { NULL, };
static struct termios *a2232_termios[MAX_A2232_BOARDS*NUMLINES];
static struct termios *a2232_termios_locked[MAX_A2232_BOARDS*NUMLINES];

/* nr of cards completely (all ports) and correctly configured */
static int nr_a2232; 

/* zorro_dev structs for the A2232's */
static struct zorro_dev *zd_a2232[MAX_A2232_BOARDS]; 
/***************************** End of Global variables **************/

/***************************** Functions ****************************/
/*** BEGIN OF REAL_DRIVER FUNCTIONS ***/

static void a2232_disable_tx_interrupts(void *ptr)
{
	struct a2232_port *port;
	volatile struct a2232status *stat;
	unsigned long flags;
  
	port = ptr;
	stat = a2232stat(port->which_a2232, port->which_port_on_a2232);
	stat->OutDisable = -1;

	/* Does this here really have to be? */
	save_flags(flags);
	cli(); 
	port->gs.flags &= ~GS_TX_INTEN;
	restore_flags(flags);
}

static void a2232_enable_tx_interrupts(void *ptr)
{
	struct a2232_port *port;
	volatile struct a2232status *stat;
	unsigned long flags;

	port = ptr;
	stat = a2232stat(port->which_a2232, port->which_port_on_a2232);
	stat->OutDisable = 0;

	/* Does this here really have to be? */
	save_flags(flags);
	cli();
	port->gs.flags |= GS_TX_INTEN;
	restore_flags(flags);
}

static void a2232_disable_rx_interrupts(void *ptr)
{
	struct a2232_port *port;
	port = ptr;
	port->disable_rx = -1;
}

static void a2232_enable_rx_interrupts(void *ptr)
{
	struct a2232_port *port;
	port = ptr;
	port->disable_rx = 0;
}

static int  a2232_get_CD(void *ptr)
{
	return ((struct a2232_port *) ptr)->cd_status;
}

static void a2232_shutdown_port(void *ptr)
{
	struct a2232_port *port;
	volatile struct a2232status *stat;
	unsigned long flags;

	port = ptr;
	stat = a2232stat(port->which_a2232, port->which_port_on_a2232);

	save_flags(flags);
	cli();

	port->gs.flags &= ~GS_ACTIVE;
	
	if (port->gs.tty && port->gs.tty->termios->c_cflag & HUPCL) {
		/* Set DTR and RTS to Low, flush output.
		   The NetBSD driver "msc.c" does it this way. */
		stat->Command = (	(stat->Command & ~A2232CMD_CMask) | 
					A2232CMD_Close );
		stat->OutFlush = -1;
		stat->Setup = -1;
	}

	restore_flags(flags);
	
	/* After analyzing control flow, I think a2232_shutdown_port
		is actually the last call from the system when at application
		level someone issues a "echo Hello >>/dev/ttyY0".
		Therefore I think the MOD_DEC_USE_COUNT should be here and
		not in "a2232_close()". See the comment in "sx.c", too.
		If you run into problems, compile this driver into the
		kernel instead of compiling it as a module. */
	MOD_DEC_USE_COUNT;
}

static int  a2232_set_real_termios(void *ptr)
{
	unsigned int cflag, baud, chsize, stopb, parity, softflow;
	int rate;
	int a2232_param, a2232_cmd;
	unsigned long flags;
	unsigned int i;
	struct a2232_port *port = ptr;
	volatile struct a2232status *status;
	volatile struct a2232memory *mem;

	if (!port->gs.tty || !port->gs.tty->termios) return 0;

	status = a2232stat(port->which_a2232, port->which_port_on_a2232);
	mem = a2232mem(port->which_a2232);
	
	a2232_param = a2232_cmd = 0;

	// get baud rate
	baud = port->gs.baud;
	if (baud == 0) {
		/* speed == 0 -> drop DTR, do nothing else */
		save_flags(flags);
		cli();
		// Clear DTR (and RTS... mhhh).
		status->Command = (	(status->Command & ~A2232CMD_CMask) |
					A2232CMD_Close );
		status->OutFlush = -1;
		status->Setup = -1;
		
		restore_flags(flags);
		return 0;
	}
	
	rate = A2232_BAUD_TABLE_NOAVAIL;
	for (i=0; i < A2232_BAUD_TABLE_NUM_RATES * 3; i += 3){
		if (a2232_baud_table[i] == baud){
			if (mem->Common.Crystal == A2232_TURBO) rate = a2232_baud_table[i+2];
			else                                    rate = a2232_baud_table[i+1];
		}
	}
	if (rate == A2232_BAUD_TABLE_NOAVAIL){
		printk("a2232: Board %d Port %d unsupported baud rate: %d baud. Using another.\n",port->which_a2232,port->which_port_on_a2232,baud);
		// This is useful for both (turbo or normal) Crystal versions.
		rate = A2232PARAM_B9600;
	}
	a2232_param |= rate;

	cflag  = port->gs.tty->termios->c_cflag;

	// get character size
	chsize = cflag & CSIZE;
	switch (chsize){
		case CS8: 	a2232_param |= A2232PARAM_8Bit; break;
		case CS7: 	a2232_param |= A2232PARAM_7Bit; break;
		case CS6: 	a2232_param |= A2232PARAM_6Bit; break;
		case CS5: 	a2232_param |= A2232PARAM_5Bit; break;
		default:	printk("a2232: Board %d Port %d unsupported character size: %d. Using 8 data bits.\n",
					port->which_a2232,port->which_port_on_a2232,chsize);
				a2232_param |= A2232PARAM_8Bit; break;
	}

	// get number of stop bits
	stopb  = cflag & CSTOPB;
	if (stopb){ // two stop bits instead of one
		printk("a2232: Board %d Port %d 2 stop bits unsupported. Using 1 stop bit.\n",
			port->which_a2232,port->which_port_on_a2232);
	}

	// Warn if RTS/CTS not wanted
	if (!(cflag & CRTSCTS)){
#ifndef A2232_SUPPRESS_RTSCTS_WARNING
		printk("a2232: Board %d Port %d cannot switch off firmware-implemented RTS/CTS hardware flow control.\n",
			port->which_a2232,port->which_port_on_a2232);
#endif
	}

	/*	I think this is correct.
		However, IXOFF means _input_ flow control and I wonder
		if one should care about IXON _output_ flow control,
		too. If this makes problems, one should turn the A2232
		firmware XON/XOFF "SoftFlow" flow control off and use
		the conventional way of inserting START/STOP characters
		by hand in throttle()/unthrottle().
	*/
	softflow = !!( port->gs.tty->termios->c_iflag & IXOFF );

	// get Parity (Enabled/Disabled? If Enabled, Odd or Even?)
	parity = cflag & (PARENB | PARODD);
	if (parity & PARENB){
		if (parity & PARODD){
			a2232_cmd |= A2232CMD_OddParity;
		}
		else{
			a2232_cmd |= A2232CMD_EvenParity;
		}
	}
	else a2232_cmd |= A2232CMD_NoParity;


	/*	Hmm. Maybe an own a2232_port structure
		member would be cleaner?	*/
	if (cflag & CLOCAL)
		port->gs.flags &= ~ASYNC_CHECK_CD;
	else
		port->gs.flags |= ASYNC_CHECK_CD;


	/* Now we have all parameters and can go to set them: */
	save_flags(flags);
	cli();

	status->Param = a2232_param | A2232PARAM_RcvBaud;
	status->Command = a2232_cmd | A2232CMD_Open |  A2232CMD_Enable;
	status->SoftFlow = softflow;
	status->OutDisable = 0;
	status->Setup = -1;

	restore_flags(flags);
	return 0;
}

static int  a2232_chars_in_buffer(void *ptr)
{
	struct a2232_port *port;
	volatile struct a2232status *status; 
	unsigned char ret; /* we need modulo-256 arithmetics */
	port = ptr;
	status = a2232stat(port->which_a2232, port->which_port_on_a2232);
#if A2232_IOBUFLEN != 256
#error "Re-Implement a2232_chars_in_buffer()!"
#endif
	ret = (status->OutHead - status->OutTail);
	return ret;
}

static void a2232_close(void *ptr)
{
	a2232_disable_tx_interrupts(ptr);
	a2232_disable_rx_interrupts(ptr);
	/* see the comment in a2232_shutdown_port above. */
	/* MOD_DEC_USE_COUNT; */
}

static void a2232_hungup(void *ptr)
{
	a2232_close(ptr);
}
/*** END   OF REAL_DRIVER FUNCTIONS ***/

/*** BEGIN  FUNCTIONS EXPECTED BY TTY DRIVER STRUCTS ***/
static int a2232_ioctl(	struct tty_struct *tty, struct file *file,
			unsigned int cmd, unsigned long arg)
{
	return -ENOIOCTLCMD;
}

static void a2232_throttle(struct tty_struct *tty)
{
/* Throttle: System cannot take another chars: Drop RTS or
             send the STOP char or whatever.
   The A2232 firmware does RTS/CTS anyway, and XON/XOFF
   if switched on. So the only thing we can do at this
   layer here is not taking any characters out of the