uart.c

linux-2.4.29操作系统的源码

{
	struct serial_state *sstate;

	sstate = rs_table + line;
	if (sstate->info) {
		sstate->count++;
		*ret_info = (ser_info_t *)sstate->info;
		return 0;
	}
	else {
		return -ENOMEM;
	}
}

/*
 * This routine is called whenever a serial port is opened.  It
 * enables interrupts for a serial port, linking in its async structure into
 * the IRQ chain.   It also performs the serial-specific
 * initialization for the tty structure.
 */
static int rs_8xx_open(struct tty_struct *tty, struct file * filp)
{
	ser_info_t	*info;
	int 		retval, line;

	line = MINOR(tty->device) - tty->driver.minor_start;
	if ((line < 0) || (line >= NR_PORTS))
		return -ENODEV;
	retval = get_async_struct(line, &info);
	if (retval)
		return retval;
	if (serial_paranoia_check(info, tty->device, "rs_open"))
		return -ENODEV;

#ifdef SERIAL_DEBUG_OPEN
	printk("rs_open %s%d, count = %d\n", tty->driver.name, info->line,
	       info->state->count);
#endif
	tty->driver_data = info;
	info->tty = tty;

	/*
	 * Start up serial port
	 */
	retval = startup(info);
	if (retval)
		return retval;

	MOD_INC_USE_COUNT;
	retval = block_til_ready(tty, filp, info);
	if (retval) {
#ifdef SERIAL_DEBUG_OPEN
		printk("rs_open returning after block_til_ready with %d\n",
		       retval);
#endif
		MOD_DEC_USE_COUNT;
		return retval;
	}

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

	info->session = current->session;
	info->pgrp = current->pgrp;

#ifdef SERIAL_DEBUG_OPEN
	printk("rs_open ttys%d successful...", info->line);
#endif
	return 0;
}

/*
 * /proc fs routines....
 */

static int inline line_info(char *buf, struct serial_state *state)
{
#ifdef notdef
	struct async_struct *info = state->info, scr_info;
	char	stat_buf[30], control, status;
#endif
	int	ret;

	ret = sprintf(buf, "%d: uart:%s port:%X irq:%d",
		      state->line,
		      (PORT_IS_SCC(state->smc_scc_num)) ? "SCC" : "SMC",
		      (unsigned int)(state->port), state->irq);

	if (!state->port || (state->type == PORT_UNKNOWN)) {
		ret += sprintf(buf+ret, "\n");
		return ret;
	}

#ifdef notdef
	/*
	 * Figure out the current RS-232 lines
	 */
	if (!info) {
		info = &scr_info;	/* This is just for serial_{in,out} */

		info->magic = SERIAL_MAGIC;
		info->port = state->port;
		info->flags = state->flags;
		info->quot = 0;
		info->tty = 0;
	}
	cli();
	status = serial_in(info, UART_MSR);
	control = info ? info->MCR : serial_in(info, UART_MCR);
	sti();

	stat_buf[0] = 0;
	stat_buf[1] = 0;
	if (control & UART_MCR_RTS)
		strcat(stat_buf, "|RTS");
	if (status & UART_MSR_CTS)
		strcat(stat_buf, "|CTS");
	if (control & UART_MCR_DTR)
		strcat(stat_buf, "|DTR");
	if (status & UART_MSR_DSR)
		strcat(stat_buf, "|DSR");
	if (status & UART_MSR_DCD)
		strcat(stat_buf, "|CD");
	if (status & UART_MSR_RI)
		strcat(stat_buf, "|RI");

	if (info->quot) {
		ret += sprintf(buf+ret, " baud:%d",
			       state->baud_base / info->quot);
	}

	ret += sprintf(buf+ret, " tx:%d rx:%d",
		      state->icount.tx, state->icount.rx);

	if (state->icount.frame)
		ret += sprintf(buf+ret, " fe:%d", state->icount.frame);

	if (state->icount.parity)
		ret += sprintf(buf+ret, " pe:%d", state->icount.parity);

	if (state->icount.brk)
		ret += sprintf(buf+ret, " brk:%d", state->icount.brk);

	if (state->icount.overrun)
		ret += sprintf(buf+ret, " oe:%d", state->icount.overrun);

	/*
	 * Last thing is the RS-232 status lines
	 */
	ret += sprintf(buf+ret, " %s\n", stat_buf+1);
#endif
	return ret;
}

int rs_8xx_read_proc(char *page, char **start, off_t off, int count,
		 int *eof, void *data)
{
	int i, len = 0;
	off_t	begin = 0;

	len += sprintf(page, "serinfo:1.0 driver:%s\n", serial_version);
	for (i = 0; i < NR_PORTS && len < 4000; i++) {
		len += line_info(page + len, &rs_table[i]);
		if (len+begin > off+count)
			goto done;
		if (len+begin < off) {
			begin += len;
			len = 0;
		}
	}
	*eof = 1;
done:
	if (off >= len+begin)
		return 0;
	*start = page + (begin-off);
	return ((count < begin+len-off) ? count : begin+len-off);
}

/*
 * ---------------------------------------------------------------------
 * rs_init() and friends
 *
 * rs_init() is called at boot-time to initialize the serial driver.
 * ---------------------------------------------------------------------
 */

/*
 * This routine prints out the appropriate serial driver version
 * number, and identifies which options were configured into this
 * driver.
 */
static _INLINE_ void show_serial_version(void)
{
 	printk(KERN_INFO "%s version %s\n", serial_name, serial_version);
}


/*
 * The serial console driver used during boot.  Note that these names
 * clash with those found in "serial.c", so we currently can't support
 * the 16xxx uarts and these at the same time.  I will fix this to become
 * an indirect function call from tty_io.c (or something).
 */

#ifdef CONFIG_SERIAL_CONSOLE

/* I need this just so I can store the virtual addresses and have
 * common functions for the early console printing.
 */
static ser_info_t consinfo;

/*
 * Print a string to the serial port trying not to disturb any possible
 * real use of the port...
 */
static void my_console_write(int idx, const char *s,
				unsigned count)
{
	struct		serial_state	*ser;
	ser_info_t			*info;
	unsigned			i, c, cr_missing, max_tx_size;
	volatile	cbd_t		*bdp, *bdbase;
	volatile	smc_uart_t	*up;
	volatile	u_char		*cp;
	unsigned long                   flags;

	ser = rs_table + idx;

	/* If the port has been initialized for general use, we have
	 * to use the buffer descriptors allocated there.  Otherwise,
	 * we simply use the single buffer allocated.
	 */
	if ((info = (ser_info_t *)ser->info) != NULL) {
		bdbase = info->tx_bd_base;
	} else {
		/* Pointer to UART in parameter ram. */
		up = (smc_uart_t *)&cpmp->cp_dparam[ser->port];

		/* Get the address of the host memory buffer.*/
		info = &consinfo;
		info->tx_bd_base = (cbd_t *)bdbase = (cbd_t *)&cpmp->cp_dpmem[up->smc_tbase];
		info->tx_cur = (cbd_t *)bdbase;
	}
	max_tx_size = console_tx_buf_len;
	cr_missing = 0;
	while (1){
		c = MIN(max_tx_size, count);
		if (c <= 0)
			break;

		local_irq_save(flags);
		bdp = info->tx_cur;
		bdbase = info->tx_bd_base;
		if (bdp->cbd_sc & BD_SC_WRAP)
			info->tx_cur = (cbd_t *)bdbase;
		else
			info->tx_cur = (cbd_t *)(bdp+1);
		local_irq_restore(flags);

		/* Wait for transmitter fifo to empty.
		 * Ready indicates output is ready, and xmt is doing
		 * that, not that it is ready for us to send.
		 */
		while (bdp->cbd_sc & BD_SC_READY);

		/* Send the characters out.
		 * If the buffer address is in the CPM DPRAM, don't
		 * convert it.
		 */
		if ((uint)(bdp->cbd_bufaddr) > (uint)IMAP_ADDR)
			cp = (u_char *)(bdp->cbd_bufaddr);
		else
			cp = info->tx_va_base + ((bdp - info->tx_bd_base) * TX_BUF_SIZE);

		i=1; /* Keeps track of consumed TX buffer space */
		if (cr_missing) {
			/* Previus loop didn't have room for the CR, insert it first in this */
			*cp++ = '\r';
			i++;
		}
		cr_missing = 0;
		for (; i <= c; i++) {
			if ((*cp++ = *s++) != '\n')
				continue; /* Copy bytes until a NewLine is found */
			/* NewLine found, see if there is space in the TX buffer to add a CR */
			if (i < max_tx_size) {
				*cp++ = '\r'; /* yes, there is space to add a CR */
				i++;
			} else
				cr_missing = 1; /* No space in the TX buffer,
						   rember it so it can be inserted in the next loop */
		}
		count -= (c-cr_missing);
		bdp->cbd_datlen = i-1;
		bdp->cbd_sc |= BD_SC_READY;

	}
	/* while (bdp->cbd_sc & BD_SC_READY); is this really needed? */
}
static void serial_console_write(struct console *c, const char *s,
				unsigned count)
{
#ifdef CONFIG_KGDB_CONSOLE
	/* Try to let stub handle output. Returns true if it did. */
	if (kgdb_output_string(s, count))
		return;
#endif
	my_console_write(c->index, s, count);
}

#ifdef CONFIG_XMON
int
xmon_8xx_write(const char *s, unsigned count)
{
	my_console_write(0, s, count);
	return(count);
}
#endif

#if defined(CONFIG_KGDB) || defined(CONFIG_XMON)
/*
 * Receive character from the serial port.  This only works well
 * before the port is initialized for real use.
 */
static int my_console_wait_key(int idx, int xmon, char *obuf)
{
	struct serial_state		*ser;
	u_char				c, *cp;
	ser_info_t			*info;
	volatile	cbd_t		*bdp;
	volatile	smc_uart_t	*up;
	int				i;

	ser = rs_table + idx;

	/* Pointer to UART in parameter ram.
	*/
	up = (smc_uart_t *)&cpmp->cp_dparam[ser->port];

	/* Get the address of the host memory buffer.
	 * If the port has been initialized for general use, we must
	 * use information from the port structure.
	 */
	if ((info = (ser_info_t *)ser->info)) {
		bdp = info->rx_cur;
	}
	else {
		bdp = (cbd_t *)&cpmp->cp_dpmem[up->smc_rbase];
		info = &consinfo;
	}

	/*
	 * We need to gracefully shut down the receiver, disable
	 * interrupts, then read the input.
	 * XMON just wants a poll.  If no character, return -1, else
	 * return the character.
	 */
	if (!xmon) {
		while (bdp->cbd_sc & BD_SC_EMPTY);
	}
	else {
		if (bdp->cbd_sc & BD_SC_EMPTY)
			return -1;
	}

	/* If the buffer address is in the CPM DPRAM, don't
	 * convert it.
	 */
	if ((uint)(bdp->cbd_bufaddr) > (uint)IMAP_ADDR)
		cp = (u_char *)(bdp->cbd_bufaddr);
	else
		cp = info->rx_va_base + ((bdp - info->rx_bd_base) * RX_BUF_SIZE);

	if (obuf) {
		i = c = bdp->cbd_datlen;
		while (i-- > 0)
			*obuf++ = *cp++;
	}
	else {
		c = *cp;
	}
	bdp->cbd_sc |= BD_SC_EMPTY;

	if (info) {
		if (bdp->cbd_sc & BD_SC_WRAP) {
			bdp = info->rx_bd_base;
		}
		else {
			bdp++;
		}
		info->rx_cur = (cbd_t *)bdp;
	}

	return((int)c);
}
#endif /* CONFIG_KGDB || CONFIG_XMON */

#ifdef CONFIG_XMON
int
xmon_8xx_read_poll(void)
{
	return(my_console_wait_key(0, 1, NULL));
}

int
xmon_8xx_read_char(void)
{
	return(my_console_wait_key(0, 0, NULL));
}
#endif

#ifdef CONFIG_KGDB
static char kgdb_buf[RX_BUF_SIZE], *kgdp;
static int kgdb_chars;

void
putDebugChar(char ch)
{
	my_console_write(0, &ch, 1);
}

char
getDebugChar(void)
{
	if (kgdb_chars <= 0) {
		kgdb_chars = my_console_wait_key(0, 0, kgdb_buf);
		kgdp = kgdb_buf;
	}
	kgdb_chars--;

	return(*kgdp++);
}

void kgdb_interruptible(int yes)
{
	volatile smc_t	*smcp;

	smcp = &cpmp->cp_smc[KGDB_SER_IDX];

	if (yes == 1)
		smcp->smc_smcm |= SMCM_RX;
	else
		smcp->smc_smcm &= ~SMCM_RX;
}

void kgdb_map_scc(void)
{
	struct		serial_state *ser;
	uint		mem_addr;
	volatile	cbd_t		*bdp;
	volatile	smc_uart_t	*up;

	cpmp = (cpm8xx_t *)&(((immap_t *)IMAP_ADDR)->im_cpm);

	/* To avoid data cache CPM DMA coherency problems, allocate a
	 * buffer in the CPM DPRAM.  This will work until the CPM and
	 * serial ports are initialized.  At that time a memory buffer
	 * will be allocated.
	 * The port is already initialized from the boot procedure, all
	 * we do here is give it a different buffer and make it a FIFO.
	 */

	ser = rs_table;

	/* Right now, assume we are using SMCs.
	*/
	up = (smc_uart_t *)&cpmp->cp_dparam[ser->port];

	/* Allocate space for an input FIFO, plus a few bytes for output.
	 * Allocate bytes to maintain word alignment.
	 */
	mem_addr = (uint)(&cpmp->cp_dpmem[0xa00]);

	/* Set the physical address of the host memory buffers in
	 * the buffer descriptors.
	 */
	bdp = (cbd_t *)&cpmp->cp_dpmem[up->smc_rbase];
	bdp->cbd_bufaddr = mem_addr;

	bdp = (cbd_t *)&cpmp->cp_dpmem[up->smc_tbase];
	bdp->cbd_bufaddr = mem_addr+RX_BUF_SIZE;

	up->smc_mrblr = RX_BUF_SIZE;		/* receive buffer length */
	up->smc_maxidl = RX_BUF_SIZE;
}
#endif

static kdev_t serial_console_device(struct console *c)
{
	return MKDEV(TTY_MAJOR, 64 + c->index);
}

/*
 *	Register console.
 */
long __init console_8xx_init(long kmem_start, long kmem_end)
{
	register_console(&sercons);
	return kmem_start;
}

#endif /* CONFIG_SERIAL_CONSOLE */

/* Index in baud rate table of the default console baud rate.
*/
static