8250.c

Linux Kernel 2.6.9 for OMAP1710

{
	unsigned int size = 8 << up->port.regshift;
	unsigned long start;
	int ret = 0;

	switch (up->port.iotype) {
	case UPIO_MEM:
		if (up->port.mapbase) {
			start = up->port.mapbase;
			start += UART_RSA_BASE << up->port.regshift;
			*res = request_mem_region(start, size, "serial-rsa");
			if (!*res)
				ret = -EBUSY;
		}
		break;

	case UPIO_HUB6:
	case UPIO_PORT:
		start = up->port.iobase;
		start += UART_RSA_BASE << up->port.regshift;
		*res = request_region(start, size, "serial-rsa");
		if (!*res)
			ret = -EBUSY;
		break;
	}

	return ret;
}

static void serial8250_release_port(struct uart_port *port)
{
	struct uart_8250_port *up = (struct uart_8250_port *)port;
	unsigned long start, offset = 0, size = 0;

	if (up->port.type == PORT_RSA) {
		offset = UART_RSA_BASE << up->port.regshift;
		size = 8;
	}

	size <<= up->port.regshift;

	switch (up->port.iotype) {
	case UPIO_MEM:
		if (up->port.mapbase) {
			/*
			 * Unmap the area.
			 */
			iounmap(up->port.membase);
			up->port.membase = NULL;

			start = up->port.mapbase;

			if (size)
				release_mem_region(start + offset, size);
			release_mem_region(start, 8 << up->port.regshift);
		}
		break;

	case UPIO_HUB6:
	case UPIO_PORT:
		start = up->port.iobase;

		if (size)
			release_region(start + offset, size);
		release_region(start + offset, 8 << up->port.regshift);
		break;

	default:
		break;
	}
}

static int serial8250_request_port(struct uart_port *port)
{
	struct uart_8250_port *up = (struct uart_8250_port *)port;
	struct resource *res = NULL, *res_rsa = NULL;
	int ret = 0;

	if (up->port.type == PORT_RSA) {
		ret = serial8250_request_rsa_resource(up, &res_rsa);
		if (ret < 0)
			return ret;
	}

	ret = serial8250_request_std_resource(up, &res);

	/*
	 * If we have a mapbase, then request that as well.
	 */
	if (ret == 0 && up->port.flags & UPF_IOREMAP) {
		int size = res->end - res->start + 1;

		up->port.membase = ioremap(up->port.mapbase, size);
		if (!up->port.membase)
			ret = -ENOMEM;
	}

	if (ret < 0) {
		if (res_rsa)
			release_resource(res_rsa);
		if (res)
			release_resource(res);
	}
	return ret;
}

static void serial8250_config_port(struct uart_port *port, int flags)
{
	struct uart_8250_port *up = (struct uart_8250_port *)port;
	struct resource *res_std = NULL, *res_rsa = NULL;
	int probeflags = PROBE_ANY;
	int ret;

#ifdef CONFIG_MCA
	/*
	 * Don't probe for MCA ports on non-MCA machines.
	 */
	if (up->port.flags & UPF_BOOT_ONLYMCA && !MCA_bus)
		return;
#endif

	/*
	 * Find the region that we can probe for.  This in turn
	 * tells us whether we can probe for the type of port.
	 */
	ret = serial8250_request_std_resource(up, &res_std);
	if (ret < 0)
		return;

	ret = serial8250_request_rsa_resource(up, &res_rsa);
	if (ret < 0)
		probeflags &= ~PROBE_RSA;

	if (flags & UART_CONFIG_TYPE)
		autoconfig(up, probeflags);
	if (up->port.type != PORT_UNKNOWN && flags & UART_CONFIG_IRQ)
		autoconfig_irq(up);

	/*
	 * If the port wasn't an RSA port, release the resource.
	 */
	if (up->port.type != PORT_RSA && res_rsa)
		release_resource(res_rsa);

	if (up->port.type == PORT_UNKNOWN && res_std)
		release_resource(res_std);
}

static int
serial8250_verify_port(struct uart_port *port, struct serial_struct *ser)
{
	if (ser->irq >= NR_IRQS || ser->irq < 0 ||
	    ser->baud_base < 9600 || ser->type < PORT_UNKNOWN ||
	    ser->type > PORT_MAX_8250 || ser->type == PORT_CIRRUS ||
	    ser->type == PORT_STARTECH)
		return -EINVAL;
	return 0;
}

static const char *
serial8250_type(struct uart_port *port)
{
	int type = port->type;

	if (type >= ARRAY_SIZE(uart_config))
		type = 0;
	return uart_config[type].name;
}

static struct uart_ops serial8250_pops = {
	.tx_empty	= serial8250_tx_empty,
	.set_mctrl	= serial8250_set_mctrl,
	.get_mctrl	= serial8250_get_mctrl,
	.stop_tx	= serial8250_stop_tx,
	.start_tx	= serial8250_start_tx,
	.stop_rx	= serial8250_stop_rx,
	.enable_ms	= serial8250_enable_ms,
	.break_ctl	= serial8250_break_ctl,
	.startup	= serial8250_startup,
	.shutdown	= serial8250_shutdown,
	.set_termios	= serial8250_set_termios,
	.pm		= serial8250_pm,
	.type		= serial8250_type,
	.release_port	= serial8250_release_port,
	.request_port	= serial8250_request_port,
	.config_port	= serial8250_config_port,
	.verify_port	= serial8250_verify_port,
};

static struct uart_8250_port serial8250_ports[UART_NR];

static void __init serial8250_isa_init_ports(void)
{
	struct uart_8250_port *up;
	static int first = 1;
	int i;

	if (!first)
		return;
	first = 0;

	for (i = 0, up = serial8250_ports; i < ARRAY_SIZE(old_serial_port);
	     i++, up++) {
		up->port.iobase   = old_serial_port[i].port;
		up->port.irq      = irq_canonicalize(old_serial_port[i].irq);
		up->port.uartclk  = old_serial_port[i].baud_base * 16;
		up->port.flags    = old_serial_port[i].flags;
		up->port.hub6     = old_serial_port[i].hub6;
		up->port.membase  = old_serial_port[i].iomem_base;
		up->port.iotype   = old_serial_port[i].io_type;
		up->port.regshift = old_serial_port[i].iomem_reg_shift;
		up->port.ops      = &serial8250_pops;
		if (share_irqs)
			up->port.flags |= UPF_SHARE_IRQ;
	}
}

static void __init serial8250_register_ports(struct uart_driver *drv)
{
	int i;

	serial8250_isa_init_ports();

	for (i = 0; i < UART_NR; i++) {
		struct uart_8250_port *up = &serial8250_ports[i];

		up->port.line = i;
		up->port.ops = &serial8250_pops;
		init_timer(&up->timer);
		up->timer.function = serial8250_timeout;

		/*
		 * ALPHA_KLUDGE_MCR needs to be killed.
		 */
		up->mcr_mask = ~ALPHA_KLUDGE_MCR;
		up->mcr_force = ALPHA_KLUDGE_MCR;

		uart_add_one_port(drv, &up->port);
	}
}

#ifdef CONFIG_SERIAL_8250_CONSOLE

#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)

/*
 *	Wait for transmitter & holding register to empty
 */
static inline void wait_for_xmitr(struct uart_8250_port *up)
{
	unsigned int status, tmout = 10000;

	/* Wait up to 10ms for the character(s) to be sent. */
	do {
		status = serial_in(up, UART_LSR);

		if (status & UART_LSR_BI)
			up->lsr_break_flag = UART_LSR_BI;

		if (--tmout == 0)
			break;
		udelay(1);
	} while ((status & BOTH_EMPTY) != BOTH_EMPTY);

	/* Wait up to 1s for flow control if necessary */
	if (up->port.flags & UPF_CONS_FLOW) {
		tmout = 1000000;
		while (--tmout &&
		       ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0))
			udelay(1);
	}
}

/*
 *	Print a string to the serial port trying not to disturb
 *	any possible real use of the port...
 *
 *	The console_lock must be held when we get here.
 */
static void
serial8250_console_write(struct console *co, const char *s, unsigned int count)
{
	struct uart_8250_port *up = &serial8250_ports[co->index];
	unsigned int ier;
	int i;

	/*
	 *	First save the UER then disable the interrupts
	 */
	ier = serial_in(up, UART_IER);

	if (up->port.type == PORT_XSCALE)
		serial_out(up, UART_IER, UART_IER_UUE);
	else
		serial_out(up, UART_IER, 0);

	/*
	 *	Now, do each character
	 */
	for (i = 0; i < count; i++, s++) {
		wait_for_xmitr(up);

		/*
		 *	Send the character out.
		 *	If a LF, also do CR...
		 */
		serial_out(up, UART_TX, *s);
		if (*s == 10) {
			wait_for_xmitr(up);
			serial_out(up, UART_TX, 13);
		}
	}

	/*
	 *	Finally, wait for transmitter to become empty
	 *	and restore the IER
	 */
	wait_for_xmitr(up);
	serial_out(up, UART_IER, ier);
}

static int __init serial8250_console_setup(struct console *co, char *options)
{
	struct uart_port *port;
	int baud = 115200;
	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.
	 */
	if (co->index >= UART_NR)
		co->index = 0;
	port = &serial8250_ports[co->index].port;
	if (!port->ops)
		return -ENODEV;

	/*
	 * Temporary fix.
	 */
	spin_lock_init(&port->lock);

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

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

static struct uart_driver serial8250_reg;
static struct console serial8250_console = {
	.name		= "ttyS",
	.write		= serial8250_console_write,
	.device		= uart_console_device,
	.setup		= serial8250_console_setup,
	.flags		= CON_PRINTBUFFER,
	.index		= -1,
	.data		= &serial8250_reg,
};

static int __init serial8250_console_init(void)
{
	serial8250_isa_init_ports();
	register_console(&serial8250_console);
	return 0;
}
console_initcall(serial8250_console_init);

static int __init serial8250_late_console_init(void)
{
	if (!(serial8250_console.flags & CON_ENABLED))
		register_console(&serial8250_console);
	return 0;
}
late_initcall(serial8250_late_console_init);

#define SERIAL8250_CONSOLE	&serial8250_console
#else
#define SERIAL8250_CONSOLE	NULL
#endif

static struct uart_driver serial8250_reg = {
	.owner			= THIS_MODULE,
	.driver_name		= "serial",
	.devfs_name		= "tts/",
	.dev_name		= "ttyS",
	.major			= TTY_MAJOR,
	.minor			= 64,
	.nr			= UART_NR,
	.cons			= SERIAL8250_CONSOLE,
};

/*
 * register_serial and unregister_serial allows for 16x50 serial ports to be
 * configured at run-time, to support PCMCIA modems.
 */

static int __register_serial(struct serial_struct *req, int line)
{
	struct uart_port port;

	port.type     = req->type;
	port.iobase   = req->port;
	port.membase  = req->iomem_base;
	port.irq      = req->irq;
	port.uartclk  = req->baud_base * 16;
	port.fifosize = req->xmit_fifo_size;
	port.regshift = req->iomem_reg_shift;
	port.iotype   = req->io_type;
	port.flags    = req->flags;
	port.mapbase  = req->iomap_base;
	port.line     = line;

	if (req->type != PORT_OMAP)
		req->flags |= UPF_BOOT_AUTOCONF;

	if (share_irqs)
		port.flags |= UPF_SHARE_IRQ;

	if (HIGH_BITS_OFFSET)
		port.iobase |= (long) req->port_high << HIGH_BITS_OFFSET;

	/*
	 * If a clock rate wasn't specified by the low level
	 * driver, then default to the standard clock rate.
	 */
	if (port.uartclk == 0)
		port.uartclk = BASE_BAUD * 16;

	return uart_register_port(&serial8250_reg, &port);
}

/**
 *	register_serial - configure a 16x50 serial port at runtime
 *	@req: request structure
 *
 *	Configure the serial port specified by the request. If the
 *	port exists and is in use an error is returned. If the port
 *	is not currently in the table it is added.
 *
 *	The port is then probed and if necessary the IRQ is autodetected
 *	If this fails an error is returned.
 *
 *	On success the port is ready to use and the line number is returned.
 */
int register_serial(struct serial_struct *req)
{
	return __register_serial(req, -1);
}

int __init early_serial_setup(struct uart_port *port)
{
	if (port->line >= ARRAY_SIZE(serial8250_ports))
		return -ENODEV;

	serial8250_isa_init_ports();
	serial8250_ports[port->line].port	= *port;
	serial8250_ports[port->line].port.ops	= &serial8250_pops;
	return 0;
}

/**
 *	unregister_serial - remove a 16x50 serial port at runtime
 *	@line: serial line number
 *
 *	Remove one serial port.  This may be called from interrupt
 *	context.
 */
void unregister_serial(int line)
{
	uart_unregister_port(&serial8250_reg, line);
}

/*
 * This is for ISAPNP only.
 */
void serial8250_get_irq_map(unsigned int *map)
{
	int i;

	for (i = 0; i < UART_NR; i++) {
		if (serial8250_ports[i].port.type != PORT_UNKNOWN &&
		    serial8250_ports[i].port.irq < 16)
			*map |= 1 << serial8250_ports[i].port.irq;
	}
}

/**
 *	serial8250_suspend_port - suspend one serial port
 *	@line:  serial line number
 *      @level: the level of port suspension, as per uart_suspend_port
 *
 *	Suspend one serial port.
 */
void serial8250_suspend_port(int line)
{
	uart_suspend_port(&serial8250_reg, &serial8250_ports[line].port);
}

/**
 *	serial8250_resume_port - resume one serial port
 *	@line:  serial line number
 *      @level: the level of port resumption, as per uart_resume_port
 *
 *	Resume one serial port.
 */
void serial8250_resume_port(int line)
{
	uart_resume_port(&serial8250_reg, &serial8250_ports[line].port);
}

static int __init serial8250_init(void)
{
	int ret, i;

	printk(KERN_INFO "Serial: 8250/16550 driver $Revision: 1.90 $ "
		"%d ports, IRQ sharing %sabled\n", (int) UART_NR,
		share_irqs ? "en" : "dis");

	for (i = 0; i < NR_IRQS; i++)
		spin_lock_init(&irq_lists[i].lock);

	ret = uart_register_driver(&serial8250_reg);
	if (ret >= 0)
		serial8250_register_ports(&serial8250_reg);

	return ret;
}

static void __exit serial8250_exit(void)
{
	int i;

	for (i = 0; i < UART_NR; i++)
		uart_remove_one_port(&serial8250_reg, &serial8250_ports[i].port);

	uart_unregister_driver(&serial8250_reg);
}

module_init(serial8250_init);
module_exit(serial8250_exit);

EXPORT_SYMBOL(register_serial);
EXPORT_SYMBOL(unregister_serial);
EXPORT_SYMBOL(serial8250_get_irq_map);
EXPORT_SYMBOL(serial8250_suspend_port);
EXPORT_SYMBOL(serial8250_resume_port);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Generic 8250/16x50 serial driver $Revision: 1.90 $");

module_param(share_irqs, uint, 0644);
MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices"
	" (unsafe)");

#ifdef CONFIG_SERIAL_8250_RSA
module_param_array(probe_rsa, ulong, probe_rsa_count, 0444);
MODULE_PARM_DESC(probe_rsa, "Probe I/O ports for RSA");
#endif
MODULE_ALIAS_CHARDEV_MAJOR(TTY_MAJOR);