mcf.c

linux 内核源代码

		port->x_char = 0;
		port->icount.tx++;
		return;
	}

	while (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY) {
		if (xmit->head == xmit->tail)
			break;
		writeb(xmit->buf[xmit->tail], port->membase + MCFUART_UTB);
		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE -1);
		port->icount.tx++;
	}

	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
		uart_write_wakeup(port);

	if (xmit->head == xmit->tail) {
		pp->imr &= ~MCFUART_UIR_TXREADY;
		writeb(pp->imr, port->membase + MCFUART_UIMR);
	}
}

/****************************************************************************/

static irqreturn_t mcf_interrupt(int irq, void *data)
{
	struct uart_port *port = data;
	struct mcf_uart *pp = (struct mcf_uart *) port;
	unsigned int isr;

	isr = readb(port->membase + MCFUART_UISR) & pp->imr;
	if (isr & MCFUART_UIR_RXREADY)
		mcf_rx_chars(pp);
	if (isr & MCFUART_UIR_TXREADY)
		mcf_tx_chars(pp);
	return IRQ_HANDLED;
}

/****************************************************************************/

static void mcf_config_port(struct uart_port *port, int flags)
{
	port->type = PORT_MCF;

	/* Clear mask, so no surprise interrupts. */
	writeb(0, port->membase + MCFUART_UIMR);

	if (request_irq(port->irq, mcf_interrupt, IRQF_DISABLED, "UART", port))
		printk(KERN_ERR "MCF: unable to attach ColdFire UART %d "
			"interrupt vector=%d\n", port->line, port->irq);
}

/****************************************************************************/

static const char *mcf_type(struct uart_port *port)
{
	return (port->type == PORT_MCF) ? "ColdFire UART" : NULL;
}

/****************************************************************************/

static int mcf_request_port(struct uart_port *port)
{
	/* UARTs always present */
	return 0;
}

/****************************************************************************/

static void mcf_release_port(struct uart_port *port)
{
	/* Nothing to release... */
}

/****************************************************************************/

static int mcf_verify_port(struct uart_port *port, struct serial_struct *ser)
{
	if ((ser->type != PORT_UNKNOWN) && (ser->type != PORT_MCF))
		return -EINVAL;
	return 0;
}

/****************************************************************************/

/*
 *	Define the basic serial functions we support.
 */
static struct uart_ops mcf_uart_ops = {
	.tx_empty	= mcf_tx_empty,
	.get_mctrl	= mcf_get_mctrl,
	.set_mctrl	= mcf_set_mctrl,
	.start_tx	= mcf_start_tx,
	.stop_tx	= mcf_stop_tx,
	.stop_rx	= mcf_stop_rx,
	.enable_ms	= mcf_enable_ms,
	.break_ctl	= mcf_break_ctl,
	.startup	= mcf_startup,
	.shutdown	= mcf_shutdown,
	.set_termios	= mcf_set_termios,
	.type		= mcf_type,
	.request_port	= mcf_request_port,
	.release_port	= mcf_release_port,
	.config_port	= mcf_config_port,
	.verify_port	= mcf_verify_port,
};

static struct mcf_uart mcf_ports[3];

#define	MCF_MAXPORTS	(sizeof(mcf_ports) / sizeof(struct mcf_uart))

/****************************************************************************/
#if defined(CONFIG_SERIAL_MCF_CONSOLE)
/****************************************************************************/

int __init early_mcf_setup(struct mcf_platform_uart *platp)
{
	struct uart_port *port;
	int i;

	for (i = 0; ((i < MCF_MAXPORTS) && (platp[i].mapbase)); i++) {
		port = &mcf_ports[i].port;

		port->line = i;
		port->type = PORT_MCF;
		port->mapbase = platp[i].mapbase;
		port->membase = (platp[i].membase) ? platp[i].membase :
			(unsigned char __iomem *) port->mapbase;
		port->iotype = SERIAL_IO_MEM;
		port->irq = platp[i].irq;
		port->uartclk = MCF_BUSCLK;
		port->flags = ASYNC_BOOT_AUTOCONF;
		port->ops = &mcf_uart_ops;
	}

	return 0;
}

/****************************************************************************/

static void mcf_console_putc(struct console *co, const char c)
{
	struct uart_port *port = &(mcf_ports + co->index)->port;
	int i;

	for (i = 0; (i < 0x10000); i++) {
		if (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY)
			break;
	}
	writeb(c, port->membase + MCFUART_UTB);
	for (i = 0; (i < 0x10000); i++) {
		if (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY)
			break;
	}
}

/****************************************************************************/

static void mcf_console_write(struct console *co, const char *s, unsigned int count)
{
	for (; (count); count--, s++) {
		mcf_console_putc(co, *s);
		if (*s == '\n')
			mcf_console_putc(co, '\r');
	}
}

/****************************************************************************/

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

	if ((co->index >= 0) && (co->index <= MCF_MAXPORTS))
		co->index = 0;
	port = &mcf_ports[co->index].port;
	if (port->membase == 0)
		return -ENODEV;

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

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

/****************************************************************************/

static struct uart_driver mcf_driver;

static struct console mcf_console = {
	.name		= "ttyS",
	.write		= mcf_console_write,
	.device		= uart_console_device,
	.setup		= mcf_console_setup,
	.flags		= CON_PRINTBUFFER,
	.index		= -1,
	.data		= &mcf_driver,
};

static int __init mcf_console_init(void)
{
	register_console(&mcf_console);
	return 0;
}

console_initcall(mcf_console_init);

#define	MCF_CONSOLE	&mcf_console

/****************************************************************************/
#else
/****************************************************************************/

#define	MCF_CONSOLE	NULL

/****************************************************************************/
#endif /* CONFIG_MCF_CONSOLE */
/****************************************************************************/

/*
 *	Define the mcf UART driver structure.
 */
static struct uart_driver mcf_driver = {
	.owner		= THIS_MODULE,
	.driver_name	= "mcf",
	.dev_name	= "ttyS",
	.major		= TTY_MAJOR,
	.minor		= 64,
	.nr		= MCF_MAXPORTS,
	.cons		= MCF_CONSOLE,
};

/****************************************************************************/

static int __devinit mcf_probe(struct platform_device *pdev)
{
	struct mcf_platform_uart *platp = pdev->dev.platform_data;
	struct uart_port *port;
	int i;

	for (i = 0; ((i < MCF_MAXPORTS) && (platp[i].mapbase)); i++) {
		port = &mcf_ports[i].port;

		port->line = i;
		port->type = PORT_MCF;
		port->mapbase = platp[i].mapbase;
		port->membase = (platp[i].membase) ? platp[i].membase :
			(unsigned char __iomem *) platp[i].mapbase;
		port->iotype = SERIAL_IO_MEM;
		port->irq = platp[i].irq;
		port->uartclk = MCF_BUSCLK;
		port->ops = &mcf_uart_ops;
		port->flags = ASYNC_BOOT_AUTOCONF;

		uart_add_one_port(&mcf_driver, port);
	}

	return 0;
}

/****************************************************************************/

static int mcf_remove(struct platform_device *pdev)
{
	struct uart_port *port;
	int i;

	for (i = 0; (i < MCF_MAXPORTS); i++) {
		port = &mcf_ports[i].port;
		if (port)
			uart_remove_one_port(&mcf_driver, port);
	}

	return 0;
}

/****************************************************************************/

static struct platform_driver mcf_platform_driver = {
	.probe		= mcf_probe,
	.remove		= __devexit_p(mcf_remove),
	.driver		= {
		.name	= "mcfuart",
		.owner	= THIS_MODULE,
	},
};

/****************************************************************************/

static int __init mcf_init(void)
{
	int rc;

	printk("ColdFire internal UART serial driver\n");

	rc = uart_register_driver(&mcf_driver);
	if (rc)
		return rc;
	rc = platform_driver_register(&mcf_platform_driver);
	if (rc)
		return rc;
	return 0;
}

/****************************************************************************/

static void __exit mcf_exit(void)
{
	platform_driver_unregister(&mcf_platform_driver);
	uart_unregister_driver(&mcf_driver);
}

/****************************************************************************/

module_init(mcf_init);
module_exit(mcf_exit);

MODULE_AUTHOR("Greg Ungerer <[e-mail]>");
MODULE_DESCRIPTION("Freescale ColdFire UART driver");
MODULE_LICENSE("GPL");

/****************************************************************************/