sa1100.c

IXP425 平台下嵌入式LINUX的串口的驱动程序

	/* byte size and parity */
	switch (cflag & CSIZE) {
	case CS7:	utcr0 = 0;		break;
	default:	utcr0 = UTCR0_DSS;	break;
	}
	if (cflag & CSTOPB)
		utcr0 |= UTCR0_SBS;
	if (cflag & PARENB) {
		utcr0 |= UTCR0_PE;
		if (!(cflag & PARODD))
			utcr0 |= UTCR0_OES;
	}

	port->read_status_mask &= UTSR0_TO_SM(UTSR0_TFS);
	port->read_status_mask |= UTSR1_TO_SM(UTSR1_ROR);
	if (iflag & INPCK)
		port->read_status_mask |= UTSR1_TO_SM(UTSR1_FRE | UTSR1_PRE);
	if (iflag & (BRKINT | PARMRK))
		port->read_status_mask |= UTSR0_TO_SM(UTSR0_RBB | UTSR0_REB);

	/*
	 * Characters to ignore
	 */
	port->ignore_status_mask = 0;
	if (iflag & IGNPAR)
		port->ignore_status_mask |= UTSR1_TO_SM(UTSR1_FRE | UTSR1_PRE);
	if (iflag & IGNBRK) {
		port->ignore_status_mask |= UTSR0_TO_SM(UTSR0_RBB | UTSR0_REB);
		/*
		 * If we're ignoring parity and break indicators,
		 * ignore overruns too (for real raw support).
		 */
		if (iflag & IGNPAR)
			port->ignore_status_mask |= UTSR1_TO_SM(UTSR1_ROR);
	}

	/* first, disable interrupts and drain transmitter */
	local_irq_save(flags);
	old_utcr3 = UART_GET_UTCR3(port);
	UART_PUT_UTCR3(port, old_utcr3 & ~(UTCR3_RIE | UTCR3_TIE));
	local_irq_restore(flags);
	while (UART_GET_UTSR1(port) & UTSR1_TBY);

	/* then, disable everything */
	UART_PUT_UTCR3(port, 0);

	/* set the parity, stop bits and data size */
	UART_PUT_UTCR0(port, utcr0);

	/* set the baud rate */
	quot -= 1;
	UART_PUT_UTCR1(port, ((quot & 0xf00) >> 8));
	UART_PUT_UTCR2(port, (quot & 0xff));

	UART_PUT_UTSR0(port, -1);

	UART_PUT_UTCR3(port, old_utcr3);
}

static const char *sa1100_type(struct uart_port *port)
{
	return port->type == PORT_SA1100 ? "SA1100" : NULL;
}

/*
 * Release the memory region(s) being used by 'port'.
 */
static void sa1100_release_port(struct uart_port *port)
{
	release_mem_region(port->mapbase, UART_PORT_SIZE);
}

/*
 * Request the memory region(s) being used by 'port'.
 */
static int sa1100_request_port(struct uart_port *port)
{
	return request_mem_region(port->mapbase, UART_PORT_SIZE,
			"serial_sa1100") != NULL ? 0 : -EBUSY;
}

/*
 * Configure/autoconfigure the port.
 */
static void sa1100_config_port(struct uart_port *port, int flags)
{
	if (flags & UART_CONFIG_TYPE && sa1100_request_port(port) == 0)
		port->type = PORT_SA1100;
}

/*
 * Verify the new serial_struct (for TIOCSSERIAL).
 * The only change we allow are to the flags and type, and
 * even then only between PORT_SA1100 and PORT_UNKNOWN
 */
static int sa1100_verify_port(struct uart_port *port, struct serial_struct *ser)
{
	int ret = 0;
	if (ser->type != PORT_UNKNOWN && ser->type != PORT_SA1100)
		ret = -EINVAL;
	if (port->irq != ser->irq)
		ret = -EINVAL;
	if (ser->io_type != SERIAL_IO_MEM)
		ret = -EINVAL;
	if (port->uartclk / 16 != ser->baud_base)
		ret = -EINVAL;
	if ((void *)port->mapbase != ser->iomem_base)
		ret = -EINVAL;
	if (port->iobase != ser->port)
		ret = -EINVAL;
	if (ser->hub6 != 0)
		ret = -EINVAL;
	return ret;
}

static struct uart_ops sa1100_pops = {
	tx_empty:	sa1100_tx_empty,
	set_mctrl:	sa1100_set_mctrl,
	get_mctrl:	sa1100_get_mctrl,
	stop_tx:	sa1100_stop_tx,
	start_tx:	sa1100_start_tx,
	stop_rx:	sa1100_stop_rx,
	enable_ms:	sa1100_enable_ms,
	break_ctl:	sa1100_break_ctl,
	startup:	sa1100_startup,
	shutdown:	sa1100_shutdown,
	change_speed:	sa1100_change_speed,
	type:		sa1100_type,
	release_port:	sa1100_release_port,
	request_port:	sa1100_request_port,
	config_port:	sa1100_config_port,
	verify_port:	sa1100_verify_port,
};

static struct uart_port sa1100_ports[NR_PORTS];

/*
 * Setup the SA1100 serial ports.  Note that we don't include the IrDA
 * port here since we have our own SIR/FIR driver (see drivers/net/irda)
 *
 * Note also that we support "console=ttySAx" where "x" is either 0 or 1.
 * Which serial port this ends up being depends on the machine you're
 * running this kernel on.  I'm not convinced that this is a good idea,
 * but that's the way it traditionally works.
 *
 * Note that NanoEngine UART3 becomes UART2, and UART2 is no longer
 * used here.
 */
static void sa1100_init_ports(void)
{
	static int first = 1;
	int i;

	if (!first)
		return;
	first = 0;

	for (i = 0; i < NR_PORTS; i++) {
		sa1100_ports[i].uartclk  = 3686400;
		sa1100_ports[i].ops      = &sa1100_pops;
		sa1100_ports[i].fifosize = 8;
	}

	/*
	 * make transmit lines outputs, so that when the port
	 * is closed, the output is in the MARK state.
	 */
	PPDR |= PPC_TXD1 | PPC_TXD3;
	PPSR |= PPC_TXD1 | PPC_TXD3;
}

void __init sa1100_register_uart_fns(struct sa1100_port_fns *fns)
{
	if (fns->enable_ms)
		sa1100_pops.enable_ms = fns->enable_ms;
	if (fns->get_mctrl)
		sa1100_pops.get_mctrl = fns->get_mctrl;
	if (fns->set_mctrl)
		sa1100_pops.set_mctrl = fns->set_mctrl;
	sa1100_open          = fns->open;
	sa1100_close         = fns->close;
	sa1100_pops.pm       = fns->pm;
	sa1100_pops.set_wake = fns->set_wake;
}

void __init sa1100_register_uart(int idx, int port)
{
	if (idx >= NR_PORTS) {
		printk(KERN_ERR __FUNCTION__ ": bad index number %d\n", idx);
		return;
	}

	switch (port) {
	case 1:
		sa1100_ports[idx].membase = (void *)&Ser1UTCR0;
		sa1100_ports[idx].mapbase = _Ser1UTCR0;
		sa1100_ports[idx].irq     = IRQ_Ser1UART;
		sa1100_ports[idx].iotype  = SERIAL_IO_MEM;
		sa1100_ports[idx].flags   = ASYNC_BOOT_AUTOCONF;
		break;

	case 2:
		sa1100_ports[idx].membase = (void *)&Ser2UTCR0;
		sa1100_ports[idx].mapbase = _Ser2UTCR0;
		sa1100_ports[idx].irq     = IRQ_Ser2ICP;
		sa1100_ports[idx].iotype  = SERIAL_IO_MEM;
		sa1100_ports[idx].flags   = ASYNC_BOOT_AUTOCONF;
		break;

	case 3:
		sa1100_ports[idx].membase = (void *)&Ser3UTCR0;
		sa1100_ports[idx].mapbase = _Ser3UTCR0;
		sa1100_ports[idx].irq     = IRQ_Ser3UART;
		sa1100_ports[idx].iotype  = SERIAL_IO_MEM;
		sa1100_ports[idx].flags   = ASYNC_BOOT_AUTOCONF;
		break;

	default:
		printk(KERN_ERR __FUNCTION__ ": bad port number %d\n", port);
	}
}


#ifdef CONFIG_SERIAL_SA1100_CONSOLE

/*
 * Interrupts are disabled on entering
 */
static void sa1100_console_write(struct console *co, const char *s, u_int count)
{
	struct uart_port *port = sa1100_ports + co->index;
	u_int old_utcr3, status, i;

	/*
	 *	First, save UTCR3 and then disable interrupts
	 */
	old_utcr3 = UART_GET_UTCR3(port);
	UART_PUT_UTCR3(port, (old_utcr3 & ~(UTCR3_RIE | UTCR3_TIE)) | UTCR3_TXE);

	/*
	 *	Now, do each character
	 */
	for (i = 0; i < count; i++) {
		do {
			status = UART_GET_UTSR1(port);
		} while (!(status & UTSR1_TNF));
		UART_PUT_CHAR(port, s[i]);
		if (s[i] == '\n') {
			do {
				status = UART_GET_UTSR1(port);
			} while (!(status & UTSR1_TNF));
			UART_PUT_CHAR(port, '\r');
		}
	}

	/*
	 *	Finally, wait for transmitter to become empty
	 *	and restore UTCR3
	 */
	do {
		status = UART_GET_UTSR1(port);
	} while (status & UTSR1_TBY);
	UART_PUT_UTCR3(port, old_utcr3);
}

static kdev_t sa1100_console_device(struct console *co)
{
	return MKDEV(SERIAL_SA1100_MAJOR, MINOR_START + co->index);
}

/*
 * If the port was already initialised (eg, by a boot loader), try to determine
 * the current setup.
 */
static void __init
sa1100_console_get_options(struct uart_port *port, int *baud, int *parity, int *bits)
{
	u_int utcr3;

	utcr3 = UART_GET_UTCR3(port) & (UTCR3_RXE | UTCR3_TXE);
	if (utcr3 == (UTCR3_RXE | UTCR3_TXE)) {
		/* ok, the port was enabled */
		u_int utcr0, quot;

		utcr0 = UART_GET_UTCR0(port);

		*parity = 'n';
		if (utcr0 & UTCR0_PE) {
			if (utcr0 & UTCR0_OES)
				*parity = 'e';
			else
				*parity = 'o';
		}

		if (utcr0 & UTCR0_DSS)
			*bits = 8;
		else
			*bits = 7;

		quot = UART_GET_UTCR2(port) | UART_GET_UTCR1(port) << 8;
		quot &= 0xfff;
		*baud = port->uartclk / (16 * (quot + 1));
	}
}

static int __init
sa1100_console_setup(struct console *co, char *options)
{
	struct uart_port *port;
	int baud = CONFIG_SA1100_DEFAULT_BAUDRATE;
	int bits = 8;
	int parity = 'n';
	int flow = 'n';

	/*
	 * Check whether an invalid uart number has been specified, and
	 * if so, search for the first available port that does have
	 * console support.
	 */
	port = uart_get_console(sa1100_ports, NR_PORTS, co);

	if (options)
		uart_parse_options(options, &baud, &parity, &bits, &flow);
	else
		sa1100_console_get_options(port, &baud, &parity, &bits);

	return uart_set_options(port, co, baud, parity, bits, flow);
}

static struct console sa1100_console = {
	name:		"ttySA",
	write:		sa1100_console_write,
	device:		sa1100_console_device,
	setup:		sa1100_console_setup,
	flags:		CON_PRINTBUFFER,
	index:		-1,
};

void __init sa1100_rs_console_init(void)
{
	sa1100_init_ports();
	register_console(&sa1100_console);
}

#define SA1100_CONSOLE	&sa1100_console
#else
#define SA1100_CONSOLE	NULL
#endif

static struct uart_driver sa1100_reg = {
	owner:			THIS_MODULE,
	normal_major:		SERIAL_SA1100_MAJOR,
#ifdef CONFIG_DEVFS_FS
	normal_name:		"ttySA%d",
	callout_name:		"cusa%d",
#else
	normal_name:		"ttySA",
	callout_name:		"cusa",
#endif
	normal_driver:		&normal,
	callout_major:		CALLOUT_SA1100_MAJOR,
	callout_driver:		&callout,
	table:			sa1100_table,
	termios:		sa1100_termios,
	termios_locked:		sa1100_termios_locked,
	minor:			MINOR_START,
	nr:			NR_PORTS,
	port:			sa1100_ports,
	cons:			SA1100_CONSOLE,
};

static int __init sa1100_serial_init(void)
{
	sa1100_init_ports();
	return uart_register_driver(&sa1100_reg);
}

static void __exit sa1100_serial_exit(void)
{
	uart_unregister_driver(&sa1100_reg);
}

module_init(sa1100_serial_init);
module_exit(sa1100_serial_exit);

EXPORT_NO_SYMBOLS;

MODULE_AUTHOR("Deep Blue Solutions Ltd");
MODULE_DESCRIPTION("SA1100 generic serial port driver");
MODULE_LICENSE("GPL");