sx.c

这是一个SIGMA方案的PMP播放器的UCLINUX程序,可播放DVD,VCD,CD MP3...有很好的参考价值.

	data_in_buffer = (sx_read_channel_byte (port, hi_txipos) - 
	                  sx_read_channel_byte (port, hi_txopos)) & 0xff;

	/* XXX Must be "HIGH_WATER" for SI card according to doc. */
	if (data_in_buffer < LOW_WATER) 
		port->gs.flags &= ~GS_TX_INTEN;

	func_exit();
}


static void sx_disable_rx_interrupts (void * ptr) 
{
	/*  struct sx_port *port = ptr; */
	func_enter();

	func_exit();
}

static void sx_enable_rx_interrupts (void * ptr) 
{
	/*  struct sx_port *port = ptr; */
	func_enter();

	func_exit();
}


/* Jeez. Isn't this simple? */
static int sx_get_CD (void * ptr) 
{
	struct sx_port *port = ptr;
	func_enter2();

	func_exit();
	return ((sx_read_channel_byte (port, hi_ip) & IP_DCD) != 0);
}


/* Jeez. Isn't this simple? */
static int sx_chars_in_buffer (void * ptr) 
{
	struct sx_port *port = ptr;
	func_enter2();

	func_exit();
	return ((sx_read_channel_byte (port, hi_txipos) - 
	         sx_read_channel_byte (port, hi_txopos)) & 0xff);
}


static void sx_shutdown_port (void * ptr) 
{
	struct sx_port *port = ptr; 

	func_enter();

	port->gs.flags &= ~ GS_ACTIVE;
	if (port->gs.tty && (port->gs.tty->termios->c_cflag & HUPCL)) {
		sx_setsignals (port, 0, 0);
		sx_reconfigure_port(port);
	}

	func_exit();
}





/* ********************************************************************** *
 *                Here are the routines that actually                     *
 *               interface with the rest of the system                    *
 * ********************************************************************** */

static int sx_open  (struct tty_struct * tty, struct file * filp)
{
	struct sx_port *port;
	int retval, line;

	func_enter();

	if (!sx_initialized) {
		return -EIO;
	}

	line = MINOR(tty->device);
	sx_dprintk (SX_DEBUG_OPEN, "%d: opening line %d. tty=%p ctty=%p, np=%d)\n", 
	            current->pid, line, tty, current->tty, sx_nports);

	if ((line < 0) || (line >= SX_NPORTS) || (line >= sx_nports))
		return -ENODEV;

	port = & sx_ports[line];
	port->c_dcd = 0; /* Make sure that the first interrupt doesn't detect a
	                    1 -> 0 transition. */


	sx_dprintk (SX_DEBUG_OPEN, "port = %p c_dcd = %d\n", port, port->c_dcd);

	tty->driver_data = port;
	port->gs.tty = tty;
	if (!port->gs.count)
		MOD_INC_USE_COUNT;
	port->gs.count++;

	sx_dprintk (SX_DEBUG_OPEN, "starting port\n");

	/*
	 * Start up serial port
	 */
	retval = gs_init_port(&port->gs);
	sx_dprintk (SX_DEBUG_OPEN, "done gs_init\n");
	if (retval) {
		port->gs.count--;
		if (port->gs.count) MOD_DEC_USE_COUNT;
		return retval;
	}

	port->gs.flags |= GS_ACTIVE;
	sx_setsignals (port, 1,1);

#if 0
	if (sx_debug & SX_DEBUG_OPEN)
		my_hd ((unsigned char *)port, sizeof (*port));
#else
	if (sx_debug & SX_DEBUG_OPEN)
		my_hd ((unsigned char *)port->board->base + port->ch_base, 
		       sizeof (*port));
#endif

	if (sx_send_command (port, HS_LOPEN, -1, HS_IDLE_OPEN) != 1) {
		printk (KERN_ERR "sx: Card didn't respond to LOPEN command.\n");
		port->gs.count--;
		if (!port->gs.count) MOD_DEC_USE_COUNT;
		return -EIO;
	}

	retval = gs_block_til_ready(port, filp);
	sx_dprintk (SX_DEBUG_OPEN, "Block til ready returned %d. Count=%d\n", 
	            retval, port->gs.count);

	if (retval) {
		/* 
		 * Don't lower gs.count here because sx_close() will be called later
		 */ 

		return retval;
	}
	/* tty->low_latency = 1; */

	if ((port->gs.count == 1) && (port->gs.flags & ASYNC_SPLIT_TERMIOS)) {
		if (tty->driver.subtype == SERIAL_TYPE_NORMAL)
			*tty->termios = port->gs.normal_termios;
		else 
			*tty->termios = port->gs.callout_termios;
		sx_set_real_termios (port);
	}

	port->gs.session = current->session;
	port->gs.pgrp = current->pgrp;
	port->c_dcd = sx_get_CD (port);
	sx_dprintk (SX_DEBUG_OPEN, "at open: cd=%d\n", port->c_dcd);
	func_exit();
	return 0;

}


/* I haven't the foggiest why the decrement use count has to happen
   here. The whole linux serial drivers stuff needs to be redesigned.
   My guess is that this is a hack to minimize the impact of a bug
   elsewhere. Thinking about it some more. (try it sometime) Try
   running minicom on a serial port that is driven by a modularized
   driver. Have the modem hangup. Then remove the driver module. Then
   exit minicom.  I expect an "oops".  -- REW */
static void sx_hungup (void *ptr)
{
  /*
	struct sx_port *port = ptr; 
  */
	func_enter ();

	/* Don't force the SX card to close. mgetty doesn't like it !!!!!! -- pvdl */
	/* For some reson we added this code. Don't know why anymore ;-( -- pvdl */
	/*
	sx_setsignals (port, 0, 0);
	sx_reconfigure_port(port);	
	sx_send_command (port, HS_CLOSE, 0, 0);

	if (sx_read_channel_byte (port, hi_hstat) != HS_IDLE_CLOSED) {
		if (sx_send_command (port, HS_FORCE_CLOSED, -1, HS_IDLE_CLOSED) != 1) {
			printk (KERN_ERR 
			        "sx: sent the force_close command, but card didn't react\n");
		} else
			sx_dprintk (SX_DEBUG_CLOSE, "sent the force_close command.\n");
	}
	*/
	MOD_DEC_USE_COUNT;
	func_exit ();
}


static void sx_close (void *ptr)
{
	struct sx_port *port = ptr; 
	/* Give the port 5 seconds to close down. */
	int to = 5 * HZ; 

	func_enter ();

	sx_setsignals (port, 0, 0);
	sx_reconfigure_port(port);	
	sx_send_command (port, HS_CLOSE, 0, 0);

	while (to-- && (sx_read_channel_byte (port, hi_hstat) != HS_IDLE_CLOSED)) {
		current->state = TASK_INTERRUPTIBLE;
		schedule_timeout (1);
		if (signal_pending (current))
				break;
	}
	current->state = TASK_RUNNING;
	if (sx_read_channel_byte (port, hi_hstat) != HS_IDLE_CLOSED) {
		if (sx_send_command (port, HS_FORCE_CLOSED, -1, HS_IDLE_CLOSED) != 1) {
			printk (KERN_ERR 
			        "sx: sent the force_close command, but card didn't react\n");
		} else
			sx_dprintk (SX_DEBUG_CLOSE, "sent the force_close command.\n");
	}

	sx_dprintk (SX_DEBUG_CLOSE, "waited %d jiffies for close. count=%d\n", 
	            5 * HZ - to - 1, port->gs.count);

	if(port->gs.count) {
		sx_dprintk(SX_DEBUG_CLOSE, "WARNING port count:%d\n", port->gs.count);
		port->gs.count = 0;
	}

	MOD_DEC_USE_COUNT;
	func_exit ();
}



/* This is relatively thorough. But then again it is only 20 lines. */
#define MARCHUP    for (i=min;i<max;i++) 
#define MARCHDOWN  for (i=max-1;i>=min;i--)
#define W0         write_sx_byte (board, i, 0x55)
#define W1         write_sx_byte (board, i, 0xaa)
#define R0         if (read_sx_byte (board, i) != 0x55) return 1
#define R1         if (read_sx_byte (board, i) != 0xaa) return 1

/* This memtest takes a human-noticable time. You normally only do it
   once a boot, so I guess that it is worth it. */
static int do_memtest (struct sx_board *board, int min, int max)
{
	int i;

	/* This is a marchb. Theoretically, marchb catches much more than
	   simpler tests. In practise, the longer test just catches more
	   intermittent errors. -- REW
	   (For the theory behind memory testing see: 
	   Testing Semiconductor Memories by A.J. van de Goor.) */
	MARCHUP	 {W0;}
	MARCHUP   {R0;W1;R1;W0;R0;W1;}
	MARCHUP   {R1;W0;W1;}
	MARCHDOWN {R1;W0;W1;W0;}
	MARCHDOWN {R0;W1;W0;}

	return 0;
}


#undef MARCHUP
#undef MARCHDOWN
#undef W0
#undef W1
#undef R0
#undef R1

#define MARCHUP    for (i=min;i<max;i+=2) 
#define MARCHDOWN  for (i=max-1;i>=min;i-=2)
#define W0         write_sx_word (board, i, 0x55aa)
#define W1         write_sx_word (board, i, 0xaa55)
#define R0         if (read_sx_word (board, i) != 0x55aa) return 1
#define R1         if (read_sx_word (board, i) != 0xaa55) return 1

#if 0
/* This memtest takes a human-noticable time. You normally only do it
   once a boot, so I guess that it is worth it. */
static int do_memtest_w (struct sx_board *board, int min, int max)
{
	int i;

	MARCHUP   {W0;}
	MARCHUP   {R0;W1;R1;W0;R0;W1;}
	MARCHUP   {R1;W0;W1;}
	MARCHDOWN {R1;W0;W1;W0;}
	MARCHDOWN {R0;W1;W0;}

	return 0;
}
#endif


static int sx_fw_ioctl (struct inode *inode, struct file *filp,
                        unsigned int cmd, unsigned long arg)
{
	int rc = 0;
	int *descr = (int *)arg, i;
	static struct sx_board *board = NULL;
	int nbytes, offset;
	unsigned long data;
	char *tmp;

	func_enter();

#if 0 
	/* Removed superuser check: Sysops can use the permissions on the device
	   file to restrict access. Recommendation: Root only. (root.root 600) */
	if (!capable(CAP_SYS_ADMIN)) {
		return -EPERM;
	}
#endif

	sx_dprintk (SX_DEBUG_FIRMWARE, "IOCTL %x: %lx\n", cmd, arg);

	if (!board) board = &boards[0];
	if (board->flags & SX_BOARD_PRESENT) {
		sx_dprintk (SX_DEBUG_FIRMWARE, "Board present! (%x)\n", 
		            board->flags);
	} else {
		sx_dprintk (SX_DEBUG_FIRMWARE, "Board not present! (%x) all:", 
		            board->flags);
		for (i=0;i< SX_NBOARDS;i++)
			sx_dprintk (SX_DEBUG_FIRMWARE, "<%x> ", boards[i].flags);
		sx_dprintk (SX_DEBUG_FIRMWARE, "\n");
		return -EIO;
	}

	switch (cmd) {
	case SXIO_SET_BOARD:
		sx_dprintk (SX_DEBUG_FIRMWARE, "set board to %ld\n", arg);
		if (arg > SX_NBOARDS) return -EIO;
		sx_dprintk (SX_DEBUG_FIRMWARE, "not out of range\n");
		if (!(boards[arg].flags	& SX_BOARD_PRESENT)) return -EIO;
		sx_dprintk (SX_DEBUG_FIRMWARE, ".. and present!\n");
		board = &boards[arg];
		break;
	case SXIO_GET_TYPE:
		rc = -ENOENT; /* If we manage to miss one, return error. */
		if (IS_SX_BOARD (board)) rc = SX_TYPE_SX;
		if (IS_CF_BOARD (board)) rc = SX_TYPE_CF;
		if (IS_SI_BOARD (board)) rc = SX_TYPE_SI;
		if (IS_EISA_BOARD (board)) rc = SX_TYPE_SI;
		sx_dprintk (SX_DEBUG_FIRMWARE, "returning type= %d\n", rc);
		break;
	case SXIO_DO_RAMTEST:
		if (sx_initialized) /* Already initialized: better not ramtest the board.  */
			return -EPERM;
		if (IS_SX_BOARD (board)) {
			rc          = do_memtest   (board, 0, 0x7000);
			if (!rc) rc = do_memtest   (board, 0, 0x7000);
			/*if (!rc) rc = do_memtest_w (board, 0, 0x7000);*/
		} else {
			rc             = do_memtest   (board, 0, 0x7ff8);
			/* if (!rc) rc = do_memtest_w (board, 0, 0x7ff8); */
		}
		sx_dprintk (SX_DEBUG_FIRMWARE, "returning memtest result= %d\n", rc);
		break;
	case SXIO_DOWNLOAD:
		if (sx_initialized) /* Already initialized */
			return -EEXIST;
		if (!sx_reset (board)) 
			return -EIO;
		sx_dprintk (SX_DEBUG_INIT, "reset the board...\n");

		tmp = kmalloc (SX_CHUNK_SIZE, GFP_USER);
		if (!tmp) return -ENOMEM;
		Get_user (nbytes, descr++);
		Get_user (offset, descr++); 
		Get_user (data,	 descr++);
		while (nbytes && data) {
			for (i=0;i<nbytes;i += SX_CHUNK_SIZE) {
				copy_from_user (tmp, (char *)data+i, 
				                (i+SX_CHUNK_SIZE>nbytes)?nbytes-i:SX_CHUNK_SIZE);
				memcpy_toio    ((char *) (board->base2 + offset + i), tmp, 
				                (i+SX_CHUNK_SIZE>nbytes)?nbytes-i:SX_CHUNK_SIZE);
			}

			Get_user (nbytes, descr++);
			Get_user (offset, descr++); 
			Get_user (data,   descr++);
		}
		kfree (tmp);
		sx_nports += sx_init_board (board);
		rc = sx_nports;
		break;
	case SXIO_INIT:
		if (sx_initialized) /* Already initialized */
			return -EEXIST;
		/* This is not allowed until all boards are initialized... */
		for (i=0;i<SX_NBOARDS;i++) {
			if ( (boards[i].flags & SX_BOARD_PRESENT) &&
			     !(boards[i].flags & SX_BOARD_INITIALIZED))
				return -EIO;
		}
		for (i=0;i<SX_NBOARDS;i++)
			if (!(boards[i].flags & SX_BOARD_PRESENT)) break;

		sx_dprintk (SX_DEBUG_FIRMWARE, "initing portstructs, %d boards, "
		            "%d channels, first board: %d ports\n", 
		            i, sx_nports, boards[0].nports);
		rc = sx_init_portstructs (i, sx_nports);
		sx_init_drivers ();
		if (rc >= 0) 
			sx_initialized++;
		break;
	case SXIO_SETDEBUG:
		sx_debug = arg;
		break;
	case SXIO_GETDEBUG:
		rc = sx_debug;
		break;
	case SXIO_GETGSDEBUG:
	case SXIO_SETGSDEBUG:
		rc = -EINVAL;
		break;
	case SXIO_GETNPORTS:
		rc = sx_nports;
		break;
	default:
		printk (KERN_WARNING "Unknown ioctl on firmware device (%x).\n", cmd);
		break;
	}
	func_exit ();
	return rc;
}


static void sx_break (struct tty_struct * tty, int flag)
{
	struct sx_port *port = tty->driver_data;
	int rv;

	if (flag)