Patchwork Add support for the nwp serial device

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Submitter Arnd Bergmann
Date Nov. 20, 2008, 2:01 p.m.
Message ID <200811201501.24000.arnd@arndb.de>
Download mbox | patch
Permalink /patch/9747/
State Superseded
Headers show

Comments

Arnd Bergmann - Nov. 20, 2008, 2:01 p.m.
From: Benjamin Krill <ben@codiert.org>

This patch adds support for the nwp serial device which is connected to
a DCR bus. It uses the of_serial device driver to determine necessary
properties from the device tree. The supported device is added as serial
port number 84.

Signed-off-by: Benjamin Krill <ben@codiert.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---

Since the serial drivers are still orphaned, should we merge this through
the powerpc tree?

---
 drivers/serial/Kconfig      |   11 +-
 drivers/serial/Makefile     |    1 +
 drivers/serial/nwpserial.c  |  443 +++++++++++++++++++++++++++++++++++++++++++
 drivers/serial/of_serial.c  |   18 ++
 include/linux/nwpserial.h   |   18 ++
 include/linux/serial_core.h |    3 +
 6 files changed, 493 insertions(+), 1 deletions(-)
 create mode 100644 drivers/serial/nwpserial.c
 create mode 100644 include/linux/nwpserial.h
Josh Boyer - Nov. 20, 2008, 2:13 p.m.
On Thu, Nov 20, 2008 at 03:01:23PM +0100, Arnd Bergmann wrote:
>From: Benjamin Krill <ben@codiert.org>
>
>This patch adds support for the nwp serial device which is connected to
>a DCR bus. It uses the of_serial device driver to determine necessary
>properties from the device tree. The supported device is added as serial
>port number 84.

What does 'NWP' stand for, and how is it different from a regular serial
port?  Also, what platforms can this device be found on currently?

Some of that should be included in the changelog, but I'm curious as well
too.

josh
Benjamin Krill - Nov. 20, 2008, 3:20 p.m.
Hi Josh,

>What does 'NWP' stand for, and how is it different from a regular serial
>port?  Also, what platforms can this device be found on currently?
>
>Some of that should be included in the changelog, but I'm curious as well
>too.

NWP stands for network processor and it is part of the QPACE - Quantum
Chromodynamics Parallel Computing on the Cell Broadband Engine
project [1]. The implementation is a lightweight uart implementation
with the focus to consume as little resources as possible and it is
connected to a DCR bus.

 Ben
Josh Boyer - Nov. 20, 2008, 3:40 p.m.
On Thu, 20 Nov 2008 16:20:54 +0100
Benjamin Krill <ben@codiert.org> wrote:

> Hi Josh,
> 
> >What does 'NWP' stand for, and how is it different from a regular serial
> >port?  Also, what platforms can this device be found on currently?
> >
> >Some of that should be included in the changelog, but I'm curious as well
> >too.
> 
> NWP stands for network processor and it is part of the QPACE - Quantum
> Chromodynamics Parallel Computing on the Cell Broadband Engine
> project [1]. The implementation is a lightweight uart implementation
> with the focus to consume as little resources as possible and it is
> connected to a DCR bus.

Neat.  Thanks.  We should include that in the changelog.

josh
David Gibson - Nov. 21, 2008, 12:35 a.m.
On Thu, Nov 20, 2008 at 03:01:23PM +0100, Arnd Bergmann wrote:
> From: Benjamin Krill <ben@codiert.org>
> 
> This patch adds support for the nwp serial device which is connected to
> a DCR bus. It uses the of_serial device driver to determine necessary
> properties from the device tree. The supported device is added as serial
> port number 84.

Uh.. registers as port number 84??  What's this random number about?
Benjamin Krill - Nov. 21, 2008, 7:21 a.m.
* David Gibson | 2008-11-21 11:35:45 [+1100]:

>
>Uh.. registers as port number 84??  What's this random number about?
>
It's just the next free number in serial_core.h.

 Ben
David Gibson - Nov. 21, 2008, 7:29 a.m.
On Fri, Nov 21, 2008 at 08:21:02AM +0100, Benjamin Krill wrote:
> * David Gibson | 2008-11-21 11:35:45 [+1100]:
> 
> >
> >Uh.. registers as port number 84??  What's this random number about?
> >
> It's just the next free number in serial_core.h.

Ah, right, sorry, those are type codes.  Thought you meant it was
registering as /dev/ttyS84 or something similarly strange.
Andrew Morton - Nov. 21, 2008, 9:22 p.m.
On Thu, 20 Nov 2008 15:01:23 +0100
Arnd Bergmann <arnd@arndb.de> wrote:

> This patch adds support for the nwp serial device which is connected to
> a DCR bus. It uses the of_serial device driver to determine necessary
> properties from the device tree. The supported device is added as serial
> port number 84.

checkpatch has a decent whine over this.  Some of those things you
might decide to ignore, other things tell me that you never ran it
anyway...

I'd suggest that nwpserial_pops and nwpserial_reg be marked const, as
they don't need to be in read/write storage.  Except that doesn't work
because the kernel isn't very const-competent.  Ho hum.


(does a powerpc allmodconfig)

drivers/serial/nwpserial.c:443: warning: data definition has no type or storage class
drivers/serial/nwpserial.c:443: warning: type defaults to 'int' in declaration of 'console_initcall'
drivers/serial/nwpserial.c:443: warning: parameter names (without types) in function declaration
drivers/serial/nwpserial.c:400: warning: 'nwpserial_console_init' defined but not used

The file fails to include linux/init.h.  It should do so, but that
doesn't fix the above.

Apparently it hasn't been tested as a kernel module...
Benjamin Herrenschmidt - Nov. 22, 2008, 10:03 p.m.
On Thu, 2008-11-20 at 15:01 +0100, Arnd Bergmann wrote:
> From: Benjamin Krill <ben@codiert.org>
> 
> This patch adds support for the nwp serial device which is connected to
> a DCR bus. It uses the of_serial device driver to determine necessary
> properties from the device tree. The supported device is added as serial
> port number 84.

I don't suppose it would have been useful to at least somewhere mention
what "NWP" serial is and where it can be found ? :-)

Cheers,
Ben.

> Signed-off-by: Benjamin Krill <ben@codiert.org>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> 
> Since the serial drivers are still orphaned, should we merge this through
> the powerpc tree?
> 
> ---
>  drivers/serial/Kconfig      |   11 +-
>  drivers/serial/Makefile     |    1 +
>  drivers/serial/nwpserial.c  |  443 +++++++++++++++++++++++++++++++++++++++++++
>  drivers/serial/of_serial.c  |   18 ++
>  include/linux/nwpserial.h   |   18 ++
>  include/linux/serial_core.h |    3 +
>  6 files changed, 493 insertions(+), 1 deletions(-)
>  create mode 100644 drivers/serial/nwpserial.c
>  create mode 100644 include/linux/nwpserial.h
> 
> diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
> index 579d63a..45dcc8d 100644
> --- a/drivers/serial/Kconfig
> +++ b/drivers/serial/Kconfig
> @@ -1297,13 +1297,22 @@ config SERIAL_NETX_CONSOLE
>  config SERIAL_OF_PLATFORM
>  	tristate "Serial port on Open Firmware platform bus"
>  	depends on PPC_OF
> -	depends on SERIAL_8250
> +	depends on SERIAL_8250 || SERIAL_OF_PLATFORM_NWPSERIAL
>  	help
>  	  If you have a PowerPC based system that has serial ports
>  	  on a platform specific bus, you should enable this option.
>  	  Currently, only 8250 compatible ports are supported, but
>  	  others can easily be added.
>  
> +config SERIAL_OF_PLATFORM_NWPSERIAL
> +	tristate "NWP serial port driver"
> +	depends on PPC_OF && PPC_DCR
> +	select SERIAL_OF_PLATFORM
> +	select SERIAL_CORE_CONSOLE
> +	select SERIAL_CORE
> +	help
> +	  This driver supports the nwp serial port.
> +
>  config SERIAL_QE
>  	tristate "Freescale QUICC Engine serial port support"
>  	depends on QUICC_ENGINE
> diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
> index 0c17c8d..05da19d 100644
> --- a/drivers/serial/Makefile
> +++ b/drivers/serial/Makefile
> @@ -70,6 +70,7 @@ obj-$(CONFIG_SERIAL_ATMEL) += atmel_serial.o
>  obj-$(CONFIG_SERIAL_UARTLITE) += uartlite.o
>  obj-$(CONFIG_SERIAL_NETX) += netx-serial.o
>  obj-$(CONFIG_SERIAL_OF_PLATFORM) += of_serial.o
> +obj-$(CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL) += nwpserial.o
>  obj-$(CONFIG_SERIAL_KS8695) += serial_ks8695.o
>  obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o
>  obj-$(CONFIG_SERIAL_QE) += ucc_uart.o
> diff --git a/drivers/serial/nwpserial.c b/drivers/serial/nwpserial.c
> new file mode 100644
> index 0000000..5f2ecab
> --- /dev/null
> +++ b/drivers/serial/nwpserial.c
> @@ -0,0 +1,443 @@
> +/*
> + *  Serial Port driver for a NWP uart device
> + *
> + *    Copyright (C) 2008 IBM Corp., Benjamin Krill <ben@codiert.org>
> + *
> + *  This program is free software; you can redistribute it and/or
> + *  modify it under the terms of the GNU General Public License
> + *  as published by the Free Software Foundation; either version
> + *  2 of the License, or (at your option) any later version.
> + *
> + */
> +#include <linux/console.h>
> +#include <linux/serial.h>
> +#include <linux/serial_reg.h>
> +#include <linux/serial_core.h>
> +#include <linux/tty.h>
> +#include <linux/irqreturn.h>
> +#include <linux/mutex.h>
> +#include <linux/of_platform.h>
> +#include <linux/of_device.h>
> +#include <linux/nwpserial.h>
> +#include <asm/prom.h>
> +#include <asm/dcr.h>
> +
> +#define NWPSERIAL_NR               2
> +
> +#define NWPSERIAL_STATUS_RXVALID 0x1
> +#define NWPSERIAL_STATUS_TXFULL  0x2
> +
> +struct nwpserial_port {
> +	struct uart_port port;
> +	dcr_host_t dcr_host;
> +	unsigned int ier;
> +	unsigned int mcr;
> +};
> +
> +static DEFINE_MUTEX(nwpserial_mutex);
> +static struct nwpserial_port nwpserial_ports[NWPSERIAL_NR];
> +
> +static void nwpserial_console_putchar(struct uart_port *port, int c)
> +{
> +	struct nwpserial_port *up = container_of(port, struct nwpserial_port, port);
> +	/* check if tx buffer is full */
> +	while ((dcr_read(up->dcr_host, UART_LSR) & UART_LSR_THRE) == 0)
> +		cpu_relax();
> +	dcr_write(up->dcr_host, UART_TX, c);
> +	up->port.icount.tx++;
> +}
> +
> +static void
> +nwpserial_console_write(struct console *co, const char *s, unsigned int count)
> +{
> +	struct nwpserial_port *up = &nwpserial_ports[co->index];
> +	unsigned long flags;
> +	int locked = 1;
> +
> +	if (oops_in_progress)
> +		locked = spin_trylock_irqsave(&up->port.lock, flags);
> +	else
> +		spin_lock_irqsave(&up->port.lock, flags);
> +
> +	/* save and disable interrupt */
> +	up->ier = dcr_read(up->dcr_host, UART_IER);
> +	dcr_write(up->dcr_host, UART_IER, up->ier & ~UART_IER_RDI);
> +
> +	uart_console_write(&up->port, s, count, nwpserial_console_putchar);
> +
> +	/* wait for transmitter to become emtpy */
> +	while ((dcr_read(up->dcr_host, UART_LSR) & UART_LSR_THRE) == 0)
> +		cpu_relax();
> +
> +	/* restore interrupt state */
> +	dcr_write(up->dcr_host, UART_IER, up->ier);
> +
> +	if (locked)
> +		spin_unlock_irqrestore(&up->port.lock, flags);
> +}
> +
> +static struct uart_driver nwpserial_reg;
> +static struct console nwpserial_console = {
> +	.name		= "ttySQ",
> +	.write		= nwpserial_console_write,
> +	.device		= uart_console_device,
> +	.flags		= CON_PRINTBUFFER,
> +	.index		= -1,
> +	.data		= &nwpserial_reg,
> +};
> +
> +/*******************************************************************************/
> +
> +static int nwpserial_request_port(struct uart_port *port)
> +{
> +	return 0;
> +}
> +
> +static void nwpserial_release_port(struct uart_port *port)
> +{
> +	/* N/A */
> +}
> +
> +static void nwpserial_config_port(struct uart_port *port, int flags)
> +{
> +	port->type = PORT_NWPSERIAL;
> +}
> +
> +static irqreturn_t nwpserial_interrupt(int irq, void *dev_id)
> +{
> +	struct nwpserial_port *up = dev_id;//container_of(dev_id, struct nwpserial_port, port);
> +	struct tty_struct *tty = up->port.info->port.tty;
> +	irqreturn_t ret;
> +	unsigned int iir;
> +	unsigned char ch;
> +
> +	spin_lock(&up->port.lock);
> +
> +	/* check if the uart was the interrupt source. */
> +	iir = dcr_read(up->dcr_host, UART_IIR);
> +	if (!iir) {
> +		ret = IRQ_NONE;
> +		goto out;
> +	}
> +
> +	do {
> +		up->port.icount.rx++;
> +		ch = dcr_read(up->dcr_host, UART_RX);
> +		if (up->port.ignore_status_mask != NWPSERIAL_STATUS_RXVALID)
> +			tty_insert_flip_char(tty, ch, TTY_NORMAL);
> +	} while (dcr_read(up->dcr_host, UART_RX) & UART_LSR_DR);
> +
> +	tty_flip_buffer_push(tty);
> +	ret = IRQ_HANDLED;
> +
> +out:
> +	spin_unlock(&up->port.lock);
> +	return ret;
> +}
> +
> +static int nwpserial_startup(struct uart_port *port)
> +{
> +	struct nwpserial_port *up = container_of(port, struct nwpserial_port, port);
> +	int err;
> +
> +	/* disable flow control by default */
> +	up->mcr = dcr_read(up->dcr_host, UART_MCR) & ~UART_MCR_AFE;
> +	dcr_write(up->dcr_host, UART_MCR, up->mcr);
> +
> +	/* register interrupt handler */
> +	err = request_irq(up->port.irq, nwpserial_interrupt,
> +	                        IRQF_SHARED, "nwpserial", up);
> +	if (err) {
> +		free_irq(up->port.irq, port);
> +		return err;
> +	}
> +
> +	/* enable interrupts */
> +	up->ier = UART_IER_RDI;
> +	dcr_write(up->dcr_host, UART_IER, up->ier);
> +
> +	/* enable receiving */
> +	up->port.ignore_status_mask &= ~NWPSERIAL_STATUS_RXVALID;
> +
> +	return 0;
> +}
> +
> +static void nwpserial_shutdown(struct uart_port *port)
> +{
> +	struct nwpserial_port *up = container_of(port, struct nwpserial_port, port);
> +
> +	/* disable receiving */
> +	up->port.ignore_status_mask |= NWPSERIAL_STATUS_RXVALID;
> +
> +	/* disable interrupts from this port */
> +	up->ier = 0;
> +	dcr_write(up->dcr_host, UART_IER, up->ier);
> +
> +	/* free irq */
> +	free_irq(up->port.irq, port);
> +}
> +
> +static int nwpserial_verify_port(struct uart_port *port, struct serial_struct *ser)
> +{
> +	return -EINVAL;
> +}
> +
> +static const char *nwpserial_type(struct uart_port *port)
> +{
> +	return port->type == PORT_NWPSERIAL ? "nwpserial" : NULL;
> +}
> +
> +static void nwpserial_set_termios(struct uart_port *port, struct ktermios *termios,
> +                                struct ktermios *old)
> +{
> +	struct nwpserial_port *up = container_of(port, struct nwpserial_port, port);
> +
> +	up->port.read_status_mask = NWPSERIAL_STATUS_RXVALID | NWPSERIAL_STATUS_TXFULL;
> +
> +	up->port.ignore_status_mask = 0;
> +	/* ignore all characters if CREAD is not set */
> +	if ((termios->c_cflag & CREAD) == 0)
> +		up->port.ignore_status_mask |= NWPSERIAL_STATUS_RXVALID;
> +}
> +
> +static void nwpserial_break_ctl(struct uart_port *port, int ctl)
> +{
> +	/* N/A */
> +}
> +
> +static void nwpserial_enable_ms(struct uart_port *port)
> +{
> +	/* N/A */
> +}
> +
> +static void nwpserial_stop_rx(struct uart_port *port)
> +{
> +	struct nwpserial_port *up = container_of(port, struct nwpserial_port, port);
> +	/* don't forward any more data (like !CREAD) */
> +	up->port.ignore_status_mask = NWPSERIAL_STATUS_RXVALID;
> +}
> +
> +static void nwpserial_putchar(struct nwpserial_port *up, unsigned char c)
> +{
> +	/* check if tx buffer is full */
> +	while ((dcr_read(up->dcr_host, UART_LSR) & UART_LSR_THRE) == 0)
> +		cpu_relax();
> +	dcr_write(up->dcr_host, UART_TX, c);
> +	up->port.icount.tx++;
> +}
> +
> +static void nwpserial_start_tx(struct uart_port *port)
> +{
> +	struct nwpserial_port *up = container_of(port, struct nwpserial_port, port);
> +	struct circ_buf *xmit  = &up->port.info->xmit;
> +
> +	if (port->x_char) {
> +		nwpserial_putchar(up, up->port.x_char);
> +		port->x_char = 0;
> +	}
> +
> +	while (!(uart_circ_empty(xmit) || uart_tx_stopped(&up->port))) {
> +		nwpserial_putchar(up, xmit->buf[xmit->tail]);
> +		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE-1);
> +	}
> +}
> +
> +static unsigned int nwpserial_get_mctrl(struct uart_port *port)
> +{
> +	return 0;
> +}
> +
> +static void nwpserial_set_mctrl(struct uart_port *port, unsigned int mctrl)
> +{
> +	/* N/A */
> +}
> +
> +static void nwpserial_stop_tx(struct uart_port *port)
> +{
> +	/* N/A */
> +}
> +
> +static unsigned int nwpserial_tx_empty(struct uart_port *port)
> +{
> +	struct nwpserial_port *up = container_of(port, struct nwpserial_port, port);
> +	unsigned long flags;
> +	int ret;
> +
> +	spin_lock_irqsave(&up->port.lock, flags);
> +	ret = dcr_read(up->dcr_host, UART_LSR);
> +	spin_unlock_irqrestore(&up->port.lock, flags);
> +
> +	return ret & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
> +}
> +
> +static struct uart_ops nwpserial_pops = {
> +	.tx_empty     = nwpserial_tx_empty,
> +	.set_mctrl    = nwpserial_set_mctrl,
> +	.get_mctrl    = nwpserial_get_mctrl,
> +	.stop_tx      = nwpserial_stop_tx,
> +	.start_tx     = nwpserial_start_tx,
> +	.stop_rx      = nwpserial_stop_rx,
> +	.enable_ms    = nwpserial_enable_ms,
> +	.break_ctl    = nwpserial_break_ctl,
> +	.startup      = nwpserial_startup,
> +	.shutdown     = nwpserial_shutdown,
> +	.set_termios  = nwpserial_set_termios,
> +	.type         = nwpserial_type,
> +	.release_port = nwpserial_release_port,
> +	.request_port = nwpserial_request_port,
> +	.config_port  = nwpserial_config_port,
> +	.verify_port  = nwpserial_verify_port,
> +};
> +
> +static struct uart_driver nwpserial_reg = {
> +	.owner       = THIS_MODULE,
> +	.driver_name = "nwpserial",
> +	.dev_name    = "ttySQ",
> +	.major       = TTY_MAJOR,
> +	.minor       = 68,
> +	.nr          = NWPSERIAL_NR,
> +	.cons        = &nwpserial_console,
> +};
> +
> +int
> +nwpserial_register_port(struct uart_port *port)
> +{
> +	struct nwpserial_port *up = NULL;
> +	int ret = -1;
> +	int i;
> +	static int first = 1;
> +	int dcr_len;
> +	int dcr_base;
> +	struct device_node *dn;
> +
> +	mutex_lock(&nwpserial_mutex);
> +
> +	dn = to_of_device(port->dev)->node;
> +	if (dn == NULL)
> +		goto out;
> +
> +	/* get dcr base. */
> +	dcr_base = dcr_resource_start(dn, 0);
> +
> +	/* find matching entry */
> +	for (i = 0; i < NWPSERIAL_NR; i++)
> +		if (nwpserial_ports[i].port.iobase == dcr_base) {
> +			up = &nwpserial_ports[i];
> +			break;
> +		}
> +
> +	/* we didn't find a mtching entry, search for a free port */
> +	if (up == NULL)
> +		for (i = 0; i < NWPSERIAL_NR; i++)
> +			if (nwpserial_ports[i].port.type == PORT_UNKNOWN &&
> +				nwpserial_ports[i].port.iobase == 0) {
> +				up = &nwpserial_ports[i];
> +				break;
> +			}
> +
> +	if (up == NULL) {
> +		ret = -EBUSY;
> +		goto out;
> +	}
> +
> +	if (first)
> +		uart_register_driver(&nwpserial_reg);
> +	first = 0;
> +
> +	up->port.membase      = port->membase;
> +	up->port.irq          = port->irq;
> +	up->port.uartclk      = port->uartclk;
> +	up->port.fifosize     = port->fifosize;
> +	up->port.regshift     = port->regshift;
> +	up->port.iotype       = port->iotype;
> +	up->port.flags        = port->flags;
> +	up->port.mapbase      = port->mapbase;
> +	up->port.private_data = port->private_data;
> +
> +	if (port->dev)
> +		up->port.dev = port->dev;
> +
> +	if (up->port.iobase != dcr_base) {
> +		up->port.ops          = &nwpserial_pops;
> +		up->port.fifosize     = 16;
> +
> +		spin_lock_init(&up->port.lock);
> +
> +		up->port.iobase = dcr_base;
> +		dcr_len = dcr_resource_len(dn, 0);
> +
> +		up->dcr_host = dcr_map(dn, dcr_base, dcr_len);
> +		if (!DCR_MAP_OK(up->dcr_host)) {
> +			printk("Cannot map DCR resources for NWPSERIAL");
> +			goto out;
> +		}
> +	}
> +
> +	ret = uart_add_one_port(&nwpserial_reg, &up->port);
> +	if (ret == 0)
> +		ret = up->port.line;
> +
> +out:
> +	mutex_unlock(&nwpserial_mutex);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL(nwpserial_register_port);
> +
> +void nwpserial_unregister_port(int line)
> +{
> +	struct nwpserial_port *up = &nwpserial_ports[line];
> +	mutex_lock(&nwpserial_mutex);
> +	uart_remove_one_port(&nwpserial_reg, &up->port);
> +
> +	up->port.type = PORT_UNKNOWN;
> +
> +	mutex_unlock(&nwpserial_mutex);
> +}
> +EXPORT_SYMBOL(nwpserial_unregister_port);
> +
> +static int __init nwpserial_console_init(void)
> +{
> +	struct nwpserial_port *up = NULL;
> +	struct device_node *dn;
> +	const char *name;
> +	int dcr_base;
> +	int dcr_len;
> +	int i;
> +
> +	/* search for a free port */
> +	for (i = 0; i < NWPSERIAL_NR; i++)
> +		if (nwpserial_ports[i].port.type == PORT_UNKNOWN) {
> +			up = &nwpserial_ports[i];
> +			break;
> +		}
> +
> +	if (up == NULL)
> +		return -1;
> +
> +	name = of_get_property(of_chosen, "linux,stdout-path", NULL);
> +	if (name == NULL)
> +		return -1;
> +
> +	dn = of_find_node_by_path(name);
> +	if (!dn)
> +		return -1;
> +
> +	spin_lock_init(&up->port.lock);
> +	up->port.ops = &nwpserial_pops;
> +	up->port.type = PORT_NWPSERIAL;
> +	up->port.fifosize = 16;
> +
> +	dcr_base = dcr_resource_start(dn, 0);
> +	dcr_len = dcr_resource_len(dn, 0);
> +	up->port.iobase = dcr_base;
> +
> +	up->dcr_host = dcr_map(dn, dcr_base, dcr_len);
> +	if (!DCR_MAP_OK(up->dcr_host)) {
> +		printk("Cannot map DCR resources for SERIAL");
> +		return -1;
> +	}
> +	register_console(&nwpserial_console);
> +	return 0;
> +}
> +console_initcall(nwpserial_console_init);
> diff --git a/drivers/serial/of_serial.c b/drivers/serial/of_serial.c
> index 8fa0ff5..bb56231 100644
> --- a/drivers/serial/of_serial.c
> +++ b/drivers/serial/of_serial.c
> @@ -14,6 +14,7 @@
>  #include <linux/serial_core.h>
>  #include <linux/serial_8250.h>
>  #include <linux/of_platform.h>
> +#include <linux/nwpserial.h>
>  
>  #include <asm/prom.h>
>  
> @@ -99,9 +100,16 @@ static int __devinit of_platform_serial_probe(struct of_device *ofdev,
>  		goto out;
>  
>  	switch (port_type) {
> +#ifdef CONFIG_SERIAL_8250
>  	case PORT_8250 ... PORT_MAX_8250:
>  		ret = serial8250_register_port(&port);
>  		break;
> +#endif
> +#ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
> +	case PORT_NWPSERIAL:
> +		ret = nwpserial_register_port(&port);
> +		break;
> +#endif
>  	default:
>  		/* need to add code for these */
>  	case PORT_UNKNOWN:
> @@ -129,9 +137,16 @@ static int of_platform_serial_remove(struct of_device *ofdev)
>  {
>  	struct of_serial_info *info = ofdev->dev.driver_data;
>  	switch (info->type) {
> +#ifdef CONFIG_SERIAL_8250
>  	case PORT_8250 ... PORT_MAX_8250:
>  		serial8250_unregister_port(info->line);
>  		break;
> +#endif
> +#ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
> +	case PORT_NWPSERIAL:
> +		nwpserial_unregister_port(info->line);
> +		break;
> +#endif
>  	default:
>  		/* need to add code for these */
>  		break;
> @@ -148,6 +163,9 @@ static struct of_device_id __devinitdata of_platform_serial_table[] = {
>  	{ .type = "serial", .compatible = "ns16450",  .data = (void *)PORT_16450, },
>  	{ .type = "serial", .compatible = "ns16550",  .data = (void *)PORT_16550, },
>  	{ .type = "serial", .compatible = "ns16750",  .data = (void *)PORT_16750, },
> +#ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
> +	{ .type = "serial", .compatible = "ibm,qpace-nwpserial",  .data = (void *)PORT_NWPSERIAL, },
> +#endif
>  	{ .type = "serial",			      .data = (void *)PORT_UNKNOWN, },
>  	{ /* end of list */ },
>  };
> diff --git a/include/linux/nwpserial.h b/include/linux/nwpserial.h
> new file mode 100644
> index 0000000..9acb215
> --- /dev/null
> +++ b/include/linux/nwpserial.h
> @@ -0,0 +1,18 @@
> +/*
> + *  Serial Port driver for a NWP uart device
> + *
> + *    Copyright (C) 2008 IBM Corp., Benjamin Krill <ben@codiert.org>
> + *
> + *  This program is free software; you can redistribute it and/or
> + *  modify it under the terms of the GNU General Public License
> + *  as published by the Free Software Foundation; either version
> + *  2 of the License, or (at your option) any later version.
> + *
> + */
> +#ifndef _NWPSERIAL_H
> +#define _NWPSERIAL_H
> +
> +int nwpserial_register_port(struct uart_port *port);
> +void nwpserial_unregister_port(int line);
> +
> +#endif /* _NWPSERIAL_H */
> diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
> index 4e4f127..4621faf 100644
> --- a/include/linux/serial_core.h
> +++ b/include/linux/serial_core.h
> @@ -158,6 +158,9 @@
>  /* SH-SCI */
>  #define PORT_SCIFA	83
>  
> +/* NWPSERIAL */
> +#define PORT_NWPSERIAL	84
> +
>  #ifdef __KERNEL__
>  
>  #include <linux/compiler.h>
Benjamin Krill - Nov. 23, 2008, 9:46 p.m.
* Andrew Morton | 2008-11-21 13:22:44 [-0800]:

>(does a powerpc allmodconfig)
>
>drivers/serial/nwpserial.c:443: warning: data definition has no type or storage class
>drivers/serial/nwpserial.c:443: warning: type defaults to 'int' in declaration of 'console_initcall'
>drivers/serial/nwpserial.c:443: warning: parameter names (without types) in function declaration
>drivers/serial/nwpserial.c:400: warning: 'nwpserial_console_init' defined but not used
>
>The file fails to include linux/init.h.  It should do so, but that
>doesn't fix the above.
>
>Apparently it hasn't been tested as a kernel module...

Console support doesn't work when the driver is build as module, all
other serial drivers did this with a further configuration option. Will
send an updated patch which fixes this and the other issues.

Patch

diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 579d63a..45dcc8d 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -1297,13 +1297,22 @@  config SERIAL_NETX_CONSOLE
 config SERIAL_OF_PLATFORM
 	tristate "Serial port on Open Firmware platform bus"
 	depends on PPC_OF
-	depends on SERIAL_8250
+	depends on SERIAL_8250 || SERIAL_OF_PLATFORM_NWPSERIAL
 	help
 	  If you have a PowerPC based system that has serial ports
 	  on a platform specific bus, you should enable this option.
 	  Currently, only 8250 compatible ports are supported, but
 	  others can easily be added.
 
+config SERIAL_OF_PLATFORM_NWPSERIAL
+	tristate "NWP serial port driver"
+	depends on PPC_OF && PPC_DCR
+	select SERIAL_OF_PLATFORM
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_CORE
+	help
+	  This driver supports the nwp serial port.
+
 config SERIAL_QE
 	tristate "Freescale QUICC Engine serial port support"
 	depends on QUICC_ENGINE
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 0c17c8d..05da19d 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -70,6 +70,7 @@  obj-$(CONFIG_SERIAL_ATMEL) += atmel_serial.o
 obj-$(CONFIG_SERIAL_UARTLITE) += uartlite.o
 obj-$(CONFIG_SERIAL_NETX) += netx-serial.o
 obj-$(CONFIG_SERIAL_OF_PLATFORM) += of_serial.o
+obj-$(CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL) += nwpserial.o
 obj-$(CONFIG_SERIAL_KS8695) += serial_ks8695.o
 obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o
 obj-$(CONFIG_SERIAL_QE) += ucc_uart.o
diff --git a/drivers/serial/nwpserial.c b/drivers/serial/nwpserial.c
new file mode 100644
index 0000000..5f2ecab
--- /dev/null
+++ b/drivers/serial/nwpserial.c
@@ -0,0 +1,443 @@ 
+/*
+ *  Serial Port driver for a NWP uart device
+ *
+ *    Copyright (C) 2008 IBM Corp., Benjamin Krill <ben@codiert.org>
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version
+ *  2 of the License, or (at your option) any later version.
+ *
+ */
+#include <linux/console.h>
+#include <linux/serial.h>
+#include <linux/serial_reg.h>
+#include <linux/serial_core.h>
+#include <linux/tty.h>
+#include <linux/irqreturn.h>
+#include <linux/mutex.h>
+#include <linux/of_platform.h>
+#include <linux/of_device.h>
+#include <linux/nwpserial.h>
+#include <asm/prom.h>
+#include <asm/dcr.h>
+
+#define NWPSERIAL_NR               2
+
+#define NWPSERIAL_STATUS_RXVALID 0x1
+#define NWPSERIAL_STATUS_TXFULL  0x2
+
+struct nwpserial_port {
+	struct uart_port port;
+	dcr_host_t dcr_host;
+	unsigned int ier;
+	unsigned int mcr;
+};
+
+static DEFINE_MUTEX(nwpserial_mutex);
+static struct nwpserial_port nwpserial_ports[NWPSERIAL_NR];
+
+static void nwpserial_console_putchar(struct uart_port *port, int c)
+{
+	struct nwpserial_port *up = container_of(port, struct nwpserial_port, port);
+	/* check if tx buffer is full */
+	while ((dcr_read(up->dcr_host, UART_LSR) & UART_LSR_THRE) == 0)
+		cpu_relax();
+	dcr_write(up->dcr_host, UART_TX, c);
+	up->port.icount.tx++;
+}
+
+static void
+nwpserial_console_write(struct console *co, const char *s, unsigned int count)
+{
+	struct nwpserial_port *up = &nwpserial_ports[co->index];
+	unsigned long flags;
+	int locked = 1;
+
+	if (oops_in_progress)
+		locked = spin_trylock_irqsave(&up->port.lock, flags);
+	else
+		spin_lock_irqsave(&up->port.lock, flags);
+
+	/* save and disable interrupt */
+	up->ier = dcr_read(up->dcr_host, UART_IER);
+	dcr_write(up->dcr_host, UART_IER, up->ier & ~UART_IER_RDI);
+
+	uart_console_write(&up->port, s, count, nwpserial_console_putchar);
+
+	/* wait for transmitter to become emtpy */
+	while ((dcr_read(up->dcr_host, UART_LSR) & UART_LSR_THRE) == 0)
+		cpu_relax();
+
+	/* restore interrupt state */
+	dcr_write(up->dcr_host, UART_IER, up->ier);
+
+	if (locked)
+		spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static struct uart_driver nwpserial_reg;
+static struct console nwpserial_console = {
+	.name		= "ttySQ",
+	.write		= nwpserial_console_write,
+	.device		= uart_console_device,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &nwpserial_reg,
+};
+
+/*******************************************************************************/
+
+static int nwpserial_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+static void nwpserial_release_port(struct uart_port *port)
+{
+	/* N/A */
+}
+
+static void nwpserial_config_port(struct uart_port *port, int flags)
+{
+	port->type = PORT_NWPSERIAL;
+}
+
+static irqreturn_t nwpserial_interrupt(int irq, void *dev_id)
+{
+	struct nwpserial_port *up = dev_id;//container_of(dev_id, struct nwpserial_port, port);
+	struct tty_struct *tty = up->port.info->port.tty;
+	irqreturn_t ret;
+	unsigned int iir;
+	unsigned char ch;
+
+	spin_lock(&up->port.lock);
+
+	/* check if the uart was the interrupt source. */
+	iir = dcr_read(up->dcr_host, UART_IIR);
+	if (!iir) {
+		ret = IRQ_NONE;
+		goto out;
+	}
+
+	do {
+		up->port.icount.rx++;
+		ch = dcr_read(up->dcr_host, UART_RX);
+		if (up->port.ignore_status_mask != NWPSERIAL_STATUS_RXVALID)
+			tty_insert_flip_char(tty, ch, TTY_NORMAL);
+	} while (dcr_read(up->dcr_host, UART_RX) & UART_LSR_DR);
+
+	tty_flip_buffer_push(tty);
+	ret = IRQ_HANDLED;
+
+out:
+	spin_unlock(&up->port.lock);
+	return ret;
+}
+
+static int nwpserial_startup(struct uart_port *port)
+{
+	struct nwpserial_port *up = container_of(port, struct nwpserial_port, port);
+	int err;
+
+	/* disable flow control by default */
+	up->mcr = dcr_read(up->dcr_host, UART_MCR) & ~UART_MCR_AFE;
+	dcr_write(up->dcr_host, UART_MCR, up->mcr);
+
+	/* register interrupt handler */
+	err = request_irq(up->port.irq, nwpserial_interrupt,
+	                        IRQF_SHARED, "nwpserial", up);
+	if (err) {
+		free_irq(up->port.irq, port);
+		return err;
+	}
+
+	/* enable interrupts */
+	up->ier = UART_IER_RDI;
+	dcr_write(up->dcr_host, UART_IER, up->ier);
+
+	/* enable receiving */
+	up->port.ignore_status_mask &= ~NWPSERIAL_STATUS_RXVALID;
+
+	return 0;
+}
+
+static void nwpserial_shutdown(struct uart_port *port)
+{
+	struct nwpserial_port *up = container_of(port, struct nwpserial_port, port);
+
+	/* disable receiving */
+	up->port.ignore_status_mask |= NWPSERIAL_STATUS_RXVALID;
+
+	/* disable interrupts from this port */
+	up->ier = 0;
+	dcr_write(up->dcr_host, UART_IER, up->ier);
+
+	/* free irq */
+	free_irq(up->port.irq, port);
+}
+
+static int nwpserial_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	return -EINVAL;
+}
+
+static const char *nwpserial_type(struct uart_port *port)
+{
+	return port->type == PORT_NWPSERIAL ? "nwpserial" : NULL;
+}
+
+static void nwpserial_set_termios(struct uart_port *port, struct ktermios *termios,
+                                struct ktermios *old)
+{
+	struct nwpserial_port *up = container_of(port, struct nwpserial_port, port);
+
+	up->port.read_status_mask = NWPSERIAL_STATUS_RXVALID | NWPSERIAL_STATUS_TXFULL;
+
+	up->port.ignore_status_mask = 0;
+	/* ignore all characters if CREAD is not set */
+	if ((termios->c_cflag & CREAD) == 0)
+		up->port.ignore_status_mask |= NWPSERIAL_STATUS_RXVALID;
+}
+
+static void nwpserial_break_ctl(struct uart_port *port, int ctl)
+{
+	/* N/A */
+}
+
+static void nwpserial_enable_ms(struct uart_port *port)
+{
+	/* N/A */
+}
+
+static void nwpserial_stop_rx(struct uart_port *port)
+{
+	struct nwpserial_port *up = container_of(port, struct nwpserial_port, port);
+	/* don't forward any more data (like !CREAD) */
+	up->port.ignore_status_mask = NWPSERIAL_STATUS_RXVALID;
+}
+
+static void nwpserial_putchar(struct nwpserial_port *up, unsigned char c)
+{
+	/* check if tx buffer is full */
+	while ((dcr_read(up->dcr_host, UART_LSR) & UART_LSR_THRE) == 0)
+		cpu_relax();
+	dcr_write(up->dcr_host, UART_TX, c);
+	up->port.icount.tx++;
+}
+
+static void nwpserial_start_tx(struct uart_port *port)
+{
+	struct nwpserial_port *up = container_of(port, struct nwpserial_port, port);
+	struct circ_buf *xmit  = &up->port.info->xmit;
+
+	if (port->x_char) {
+		nwpserial_putchar(up, up->port.x_char);
+		port->x_char = 0;
+	}
+
+	while (!(uart_circ_empty(xmit) || uart_tx_stopped(&up->port))) {
+		nwpserial_putchar(up, xmit->buf[xmit->tail]);
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE-1);
+	}
+}
+
+static unsigned int nwpserial_get_mctrl(struct uart_port *port)
+{
+	return 0;
+}
+
+static void nwpserial_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	/* N/A */
+}
+
+static void nwpserial_stop_tx(struct uart_port *port)
+{
+	/* N/A */
+}
+
+static unsigned int nwpserial_tx_empty(struct uart_port *port)
+{
+	struct nwpserial_port *up = container_of(port, struct nwpserial_port, port);
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	ret = dcr_read(up->dcr_host, UART_LSR);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	return ret & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
+}
+
+static struct uart_ops nwpserial_pops = {
+	.tx_empty     = nwpserial_tx_empty,
+	.set_mctrl    = nwpserial_set_mctrl,
+	.get_mctrl    = nwpserial_get_mctrl,
+	.stop_tx      = nwpserial_stop_tx,
+	.start_tx     = nwpserial_start_tx,
+	.stop_rx      = nwpserial_stop_rx,
+	.enable_ms    = nwpserial_enable_ms,
+	.break_ctl    = nwpserial_break_ctl,
+	.startup      = nwpserial_startup,
+	.shutdown     = nwpserial_shutdown,
+	.set_termios  = nwpserial_set_termios,
+	.type         = nwpserial_type,
+	.release_port = nwpserial_release_port,
+	.request_port = nwpserial_request_port,
+	.config_port  = nwpserial_config_port,
+	.verify_port  = nwpserial_verify_port,
+};
+
+static struct uart_driver nwpserial_reg = {
+	.owner       = THIS_MODULE,
+	.driver_name = "nwpserial",
+	.dev_name    = "ttySQ",
+	.major       = TTY_MAJOR,
+	.minor       = 68,
+	.nr          = NWPSERIAL_NR,
+	.cons        = &nwpserial_console,
+};
+
+int
+nwpserial_register_port(struct uart_port *port)
+{
+	struct nwpserial_port *up = NULL;
+	int ret = -1;
+	int i;
+	static int first = 1;
+	int dcr_len;
+	int dcr_base;
+	struct device_node *dn;
+
+	mutex_lock(&nwpserial_mutex);
+
+	dn = to_of_device(port->dev)->node;
+	if (dn == NULL)
+		goto out;
+
+	/* get dcr base. */
+	dcr_base = dcr_resource_start(dn, 0);
+
+	/* find matching entry */
+	for (i = 0; i < NWPSERIAL_NR; i++)
+		if (nwpserial_ports[i].port.iobase == dcr_base) {
+			up = &nwpserial_ports[i];
+			break;
+		}
+
+	/* we didn't find a mtching entry, search for a free port */
+	if (up == NULL)
+		for (i = 0; i < NWPSERIAL_NR; i++)
+			if (nwpserial_ports[i].port.type == PORT_UNKNOWN &&
+				nwpserial_ports[i].port.iobase == 0) {
+				up = &nwpserial_ports[i];
+				break;
+			}
+
+	if (up == NULL) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	if (first)
+		uart_register_driver(&nwpserial_reg);
+	first = 0;
+
+	up->port.membase      = port->membase;
+	up->port.irq          = port->irq;
+	up->port.uartclk      = port->uartclk;
+	up->port.fifosize     = port->fifosize;
+	up->port.regshift     = port->regshift;
+	up->port.iotype       = port->iotype;
+	up->port.flags        = port->flags;
+	up->port.mapbase      = port->mapbase;
+	up->port.private_data = port->private_data;
+
+	if (port->dev)
+		up->port.dev = port->dev;
+
+	if (up->port.iobase != dcr_base) {
+		up->port.ops          = &nwpserial_pops;
+		up->port.fifosize     = 16;
+
+		spin_lock_init(&up->port.lock);
+
+		up->port.iobase = dcr_base;
+		dcr_len = dcr_resource_len(dn, 0);
+
+		up->dcr_host = dcr_map(dn, dcr_base, dcr_len);
+		if (!DCR_MAP_OK(up->dcr_host)) {
+			printk("Cannot map DCR resources for NWPSERIAL");
+			goto out;
+		}
+	}
+
+	ret = uart_add_one_port(&nwpserial_reg, &up->port);
+	if (ret == 0)
+		ret = up->port.line;
+
+out:
+	mutex_unlock(&nwpserial_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL(nwpserial_register_port);
+
+void nwpserial_unregister_port(int line)
+{
+	struct nwpserial_port *up = &nwpserial_ports[line];
+	mutex_lock(&nwpserial_mutex);
+	uart_remove_one_port(&nwpserial_reg, &up->port);
+
+	up->port.type = PORT_UNKNOWN;
+
+	mutex_unlock(&nwpserial_mutex);
+}
+EXPORT_SYMBOL(nwpserial_unregister_port);
+
+static int __init nwpserial_console_init(void)
+{
+	struct nwpserial_port *up = NULL;
+	struct device_node *dn;
+	const char *name;
+	int dcr_base;
+	int dcr_len;
+	int i;
+
+	/* search for a free port */
+	for (i = 0; i < NWPSERIAL_NR; i++)
+		if (nwpserial_ports[i].port.type == PORT_UNKNOWN) {
+			up = &nwpserial_ports[i];
+			break;
+		}
+
+	if (up == NULL)
+		return -1;
+
+	name = of_get_property(of_chosen, "linux,stdout-path", NULL);
+	if (name == NULL)
+		return -1;
+
+	dn = of_find_node_by_path(name);
+	if (!dn)
+		return -1;
+
+	spin_lock_init(&up->port.lock);
+	up->port.ops = &nwpserial_pops;
+	up->port.type = PORT_NWPSERIAL;
+	up->port.fifosize = 16;
+
+	dcr_base = dcr_resource_start(dn, 0);
+	dcr_len = dcr_resource_len(dn, 0);
+	up->port.iobase = dcr_base;
+
+	up->dcr_host = dcr_map(dn, dcr_base, dcr_len);
+	if (!DCR_MAP_OK(up->dcr_host)) {
+		printk("Cannot map DCR resources for SERIAL");
+		return -1;
+	}
+	register_console(&nwpserial_console);
+	return 0;
+}
+console_initcall(nwpserial_console_init);
diff --git a/drivers/serial/of_serial.c b/drivers/serial/of_serial.c
index 8fa0ff5..bb56231 100644
--- a/drivers/serial/of_serial.c
+++ b/drivers/serial/of_serial.c
@@ -14,6 +14,7 @@ 
 #include <linux/serial_core.h>
 #include <linux/serial_8250.h>
 #include <linux/of_platform.h>
+#include <linux/nwpserial.h>
 
 #include <asm/prom.h>
 
@@ -99,9 +100,16 @@  static int __devinit of_platform_serial_probe(struct of_device *ofdev,
 		goto out;
 
 	switch (port_type) {
+#ifdef CONFIG_SERIAL_8250
 	case PORT_8250 ... PORT_MAX_8250:
 		ret = serial8250_register_port(&port);
 		break;
+#endif
+#ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
+	case PORT_NWPSERIAL:
+		ret = nwpserial_register_port(&port);
+		break;
+#endif
 	default:
 		/* need to add code for these */
 	case PORT_UNKNOWN:
@@ -129,9 +137,16 @@  static int of_platform_serial_remove(struct of_device *ofdev)
 {
 	struct of_serial_info *info = ofdev->dev.driver_data;
 	switch (info->type) {
+#ifdef CONFIG_SERIAL_8250
 	case PORT_8250 ... PORT_MAX_8250:
 		serial8250_unregister_port(info->line);
 		break;
+#endif
+#ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
+	case PORT_NWPSERIAL:
+		nwpserial_unregister_port(info->line);
+		break;
+#endif
 	default:
 		/* need to add code for these */
 		break;
@@ -148,6 +163,9 @@  static struct of_device_id __devinitdata of_platform_serial_table[] = {
 	{ .type = "serial", .compatible = "ns16450",  .data = (void *)PORT_16450, },
 	{ .type = "serial", .compatible = "ns16550",  .data = (void *)PORT_16550, },
 	{ .type = "serial", .compatible = "ns16750",  .data = (void *)PORT_16750, },
+#ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
+	{ .type = "serial", .compatible = "ibm,qpace-nwpserial",  .data = (void *)PORT_NWPSERIAL, },
+#endif
 	{ .type = "serial",			      .data = (void *)PORT_UNKNOWN, },
 	{ /* end of list */ },
 };
diff --git a/include/linux/nwpserial.h b/include/linux/nwpserial.h
new file mode 100644
index 0000000..9acb215
--- /dev/null
+++ b/include/linux/nwpserial.h
@@ -0,0 +1,18 @@ 
+/*
+ *  Serial Port driver for a NWP uart device
+ *
+ *    Copyright (C) 2008 IBM Corp., Benjamin Krill <ben@codiert.org>
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version
+ *  2 of the License, or (at your option) any later version.
+ *
+ */
+#ifndef _NWPSERIAL_H
+#define _NWPSERIAL_H
+
+int nwpserial_register_port(struct uart_port *port);
+void nwpserial_unregister_port(int line);
+
+#endif /* _NWPSERIAL_H */
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 4e4f127..4621faf 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -158,6 +158,9 @@ 
 /* SH-SCI */
 #define PORT_SCIFA	83
 
+/* NWPSERIAL */
+#define PORT_NWPSERIAL	84
+
 #ifdef __KERNEL__
 
 #include <linux/compiler.h>