uart00.c

IXP425 平台下嵌入式LINUX的串口的驱动程序

	if (break_state == -1)
		mcr |= UART_MCR_BR_MSK;
	else
		mcr &= ~UART_MCR_BR_MSK;
	UART_PUT_MCR(port, mcr);
}

static inline u_int uart_calculate_quot(struct uart_info *info, u_int baud)
{
	u_int quot;

	/* Special case: B0 rate */
	if (!baud)
		baud = 9600;

	quot = (info->port->uartclk / (16 * baud)-1)  ;

	return quot;
}
static void uart00_change_speed(struct uart_port *port, u_int cflag, u_int iflag, u_int quot)
{
	u_int uart_mc=0, old_ies;
	unsigned long flags;

#ifdef DEBUG
	printk("uart00_set_cflag(0x%x) called\n", cflag);
#endif
	/* byte size and parity */
	switch (cflag & CSIZE) {
	case CS5: uart_mc = UART_MC_CLS_CHARLEN_5; break;
	case CS6: uart_mc = UART_MC_CLS_CHARLEN_6; break;
	case CS7: uart_mc = UART_MC_CLS_CHARLEN_7; break;
	default:  uart_mc = UART_MC_CLS_CHARLEN_8; break; // CS8
	}
	if (cflag & CSTOPB)
		uart_mc|= UART_MC_ST_TWO;
	if (cflag & PARENB) {
		uart_mc |= UART_MC_PE_MSK;
		if (!(cflag & PARODD))
			uart_mc |= UART_MC_EP_MSK;
	}

	port->read_status_mask = UART_RDS_OE_MSK;
	if (iflag & INPCK)
		port->read_status_mask |= UART_RDS_FE_MSK | UART_RDS_PE_MSK;
	if (iflag & (BRKINT | PARMRK))
		port->read_status_mask |= UART_RDS_BI_MSK;

	/*
	 * Characters to ignore
	 */
	port->ignore_status_mask = 0;
	if (iflag & IGNPAR)
		port->ignore_status_mask |= UART_RDS_FE_MSK | UART_RDS_PE_MSK;
	if (iflag & IGNBRK) {
		port->ignore_status_mask |= UART_RDS_BI_MSK;
		/*
		 * If we're ignoring parity and break indicators,
		 * ignore overruns to (for real raw support).
		 */
		if (iflag & IGNPAR)
			port->ignore_status_mask |= UART_RDS_OE_MSK;
	}

	/* first, disable everything */
	save_flags(flags); cli();
	old_ies = UART_GET_IES(port); 

	if ((port->flags & ASYNC_HARDPPS_CD) ||
	    (cflag & CRTSCTS) || !(cflag & CLOCAL))
		old_ies |= UART_IES_ME_MSK;


	/* Set baud rate */
	UART_PUT_DIV_LO(port, (quot & 0xff));
	UART_PUT_DIV_HI(port, ((quot & 0xf00) >> 8));
   

	UART_PUT_MC(port, uart_mc);
	UART_PUT_IES(port, old_ies);

	restore_flags(flags);
}

static int uart00_startup(struct uart_port *port, struct uart_info *info)
{
	int retval;

	/* 
	 * Use iobase to store a pointer to info. We need this to start a 
	 * transmission as the tranmittr interrupt is only generated on
	 * the transition to the idle state 
	 */

	port->iobase=(u_int)info;
	
	/*
	 * Allocate the IRQ
	 */
	retval = request_irq(port->irq, uart00_int, 0, "uart00", info);
	if (retval)
		return retval;

	/*
	 * Finally, enable interrupts. Use the TII interrupt to minimise 
	 * the number of interrupts generated. If higher performance is 
	 * needed, consider using the TI interrupt with a suitable FIFO
	 * threshold
	 */
	UART_PUT_IES(port, UART_IES_RE_MSK | UART_IES_TIE_MSK);

	return 0;
}

static void uart00_shutdown(struct uart_port *port, struct uart_info *info)
{
	/*
	 * disable all interrupts, disable the port
	 */
	UART_PUT_IEC(port, 0xff);

	/* disable break condition and fifos */
	UART_PUT_MCR(port, UART_GET_MCR(port) &~UART_MCR_BR_MSK);

	/*
	 * Free the interrupt
	 */
	free_irq(port->irq, info);
}

static const char *uart00_type(struct uart_port *port)
{
	return port->type == PORT_UART00 ? "UART00" : NULL;
}

/*
 * Release the memory region(s) being used by 'port'
 */
static void uart00_release_port(struct uart_port *port)
{
	release_mem_region(port->mapbase, UART_PORT_SIZE);

#ifdef CONFIG_ARCH_CAMELOT
	if(port->membase!=(void*)IO_ADDRESS(EXC_UART00_BASE)){
		iounmap(port->membase);
	}
#endif
}

/*
 * Request the memory region(s) being used by 'port'
 */
static int uart00_request_port(struct uart_port *port)
{
	int result;

	result = request_mem_region(port->mapbase, UART_PORT_SIZE,
				    "serial_uart00") != NULL ? 0 : -EBUSY;
	if (result)
		return result;

	port->membase = ioremap(port->mapbase, SZ_4K);
	if (!port->membase) {
		printk(KERN_ERR "serial00: cannot map io memory\n");
		release_mem_region(port->mapbase, UART_PORT_SIZE);
	}

	return port->membase ? 0 : -ENOMEM;
}

/*
 * Configure/autoconfigure the port.
 */
static void uart00_config_port(struct uart_port *port, int flags)
{
	if (flags & UART_CONFIG_TYPE) {
		if (uart00_request_port(port) == 0)
			port->type = PORT_UART00;
	}
}

/*
 * verify the new serial_struct (for TIOCSSERIAL).
 */
static int uart00_verify_port(struct uart_port *port, struct serial_struct *ser)
{
	int ret = 0;
	if (ser->type != PORT_UNKNOWN && ser->type != PORT_UART00)
		ret = -EINVAL;
	if (ser->irq < 0 || ser->irq >= NR_IRQS)
		ret = -EINVAL;
	if (ser->baud_base < 9600)
		ret = -EINVAL;
	return ret;
}

static struct uart_ops uart00_pops = {
	tx_empty:	uart00_tx_empty,
	set_mctrl:	uart00_set_mctrl_null,
	get_mctrl:	uart00_get_mctrl,
	stop_tx:	uart00_stop_tx,
	start_tx:	uart00_start_tx,
	stop_rx:	uart00_stop_rx,
	enable_ms:	uart00_enable_ms,
	break_ctl:	uart00_break_ctl,
	startup:	uart00_startup,
	shutdown:	uart00_shutdown,
	change_speed:	uart00_change_speed,
	type:		uart00_type,
	release_port:	uart00_release_port,
	request_port:	uart00_request_port,
	config_port:	uart00_config_port,
	verify_port:	uart00_verify_port,
};

#ifdef CONFIG_ARCH_CAMELOT
static struct uart_port epxa10db_port = {
	membase:	(void*)IO_ADDRESS(EXC_UART00_BASE),
	mapbase:        EXC_UART00_BASE,
	iotype:		SERIAL_IO_MEM,
	irq:		IRQ_UART,
	uartclk:	EXC_AHB2_CLK_FREQUENCY,
	fifosize:	16,
	ops:		&uart00_pops,
	flags:          ASYNC_BOOT_AUTOCONF,
};
#endif

#ifdef CONFIG_SERIAL_UART00_CONSOLE
static void uart00_console_write(struct console *co, const char *s, unsigned count)
{
#ifdef CONFIG_ARCH_CAMELOT
	struct uart_port *port = &epxa10db_port;
	unsigned int status, old_ies;
	int i;

	/*
	 *	First save the CR then disable the interrupts
	 */
	old_ies = UART_GET_IES(port);
	UART_PUT_IEC(port,0xff);

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

	/*
	 *	Finally, wait for transmitter to become empty
	 *	and restore the IES
	 */
	do {
		status = UART_GET_TSR(port);
	} while (status & UART_TSR_TX_LEVEL_MSK);
	UART_PUT_IES(port, old_ies);
#endif
}

static kdev_t uart00_console_device(struct console *co)
{
	return MKDEV(SERIAL_UART00_MAJOR, SERIAL_UART00_MINOR + co->index);
}

static void /*__init*/ uart00_console_get_options(struct uart_port *port, int *baud, int *parity, int *bits)
{
	u_int uart_mc, quot;
	uart_mc= UART_GET_MC(port);

	*parity = 'n';
	if (uart_mc & UART_MC_PE_MSK) {
		if (uart_mc & UART_MC_EP_MSK)
			*parity = 'e';
		else
			*parity = 'o';
	}

	switch (uart_mc & UART_MC_CLS_MSK){

	case UART_MC_CLS_CHARLEN_5:
		*bits = 5;
		break;
	case UART_MC_CLS_CHARLEN_6:
		*bits = 6;
		break;
	case UART_MC_CLS_CHARLEN_7:
		*bits = 7;
		break;
	case UART_MC_CLS_CHARLEN_8:
		*bits = 8;
		break;
	}
	quot = UART_GET_DIV_LO(port) | (UART_GET_DIV_HI(port) << 8);
	*baud = port->uartclk / (16 *quot );
}

static int __init uart00_console_setup(struct console *co, char *options)
{
	struct uart_port *port;
	int baud = 38400;
	int bits = 8;
	int parity = 'n';
	int flow= 'n';

#ifdef CONFIG_ARCH_CAMELOT
	/*
	 * Check whether an invalid uart number has been specified, and
	 * if so, search for the first available port that does have
	 * console support.
	 */
	port = &epxa10db_port;
	co->index = 0;
#else
	return -ENODEV;
#endif

	if (options)
		uart_parse_options(options, &baud, &parity, &bits, &flow);
	else
		uart00_console_get_options(port, &baud, &parity, &bits);

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

static struct console uart00_console = {
	name:           SERIAL_UART00_NAME,
	write:		uart00_console_write,
	device:		uart00_console_device,
	setup:		uart00_console_setup,
	flags:		CON_PRINTBUFFER,
	index:		0,
};

void __init uart00_console_init(void)
{
	register_console(&uart00_console);
}

#define UART00_CONSOLE	&uart00_console
#else
#define UART00_CONSOLE	NULL
#endif

static struct uart_driver uart00_reg = {
	owner:                  NULL,
	normal_major:		SERIAL_UART00_MAJOR,
	normal_name:		SERIAL_UART00_NAME,
	normal_driver:		&normal,
	callout_major:		CALLOUT_UART00_MAJOR,
	callout_name:		CALLOUT_UART00_NAME,
	callout_driver:		&callout,
	table:			uart00_table,
	termios:		uart00_termios,
	termios_locked:		uart00_termios_locked,
	minor:			SERIAL_UART00_MINOR,
	nr:			UART_NR,
#ifdef CONFIG_ARCH_CAMELOT
	port:			&epxa10db_port,
#endif
	state:			NULL,
	cons:			UART00_CONSOLE,
};

static int __init uart00_init(void)
{
	printk(KERN_WARNING "serial_uart00:Using temporary major/minor pairs - these WILL change in the future\n");

	return uart_register_driver(&uart00_reg);
}


__initcall(uart00_init);