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serial: Add driver for the Cell Network Processor serial port NWP device

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Add 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 85.

NWP stands for network processor and it is part of the QPACE - Quantum
Chromodynamics Parallel Computing on the Cell Broadband Engine project.
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.

Signed-off-by: Benjamin Krill <ben@codiert.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Benjamin Krill 2009-01-07 10:32:38 +01:00 committed by Benjamin Herrenschmidt
parent 2b79d69623
commit 5886188dc7
6 changed files with 534 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
drivers/serial/Kconfig
View File

@ -1320,13 +1320,30 @@ 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 cell network processor nwp serial
device.
config SERIAL_OF_PLATFORM_NWPSERIAL_CONSOLE
bool "Console on NWP serial port"
depends on SERIAL_OF_PLATFORM_NWPSERIAL=y
select SERIAL_CORE_CONSOLE
help
Support for Console on the NWP serial ports.
config SERIAL_QE
tristate "Freescale QUICC Engine serial port support"
depends on QUICC_ENGINE

1
drivers/serial/Makefile
View File

@ -72,6 +72,7 @@ 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

475
drivers/serial/nwpserial.c Normal file
View File

@ -0,0 +1,475 @@
/*
* 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/init.h>
#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 wait_for_bits(struct nwpserial_port *up, int bits)
{
unsigned int status, tmout = 10000;
/* Wait up to 10ms for the character(s) to be sent. */
do {
status = dcr_read(up->dcr_host, UART_LSR);
if (--tmout == 0)
break;
udelay(1);
} while ((status & bits) != bits);
}
#ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL_CONSOLE
static void nwpserial_console_putchar(struct uart_port *port, int c)
{
struct nwpserial_port *up;
up = container_of(port, struct nwpserial_port, port);
/* check if tx buffer is full */
wait_for_bits(up, UART_LSR_THRE);
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,
};
#define NWPSERIAL_CONSOLE (&nwpserial_console)
#else
#define NWPSERIAL_CONSOLE NULL
#endif /* CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL_CONSOLE */
/**************************************************************************/
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;
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;
int err;
up = container_of(port, struct nwpserial_port, port);
/* 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)
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;
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;
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;
/* Copy back the old hardware settings */
if (old)
tty_termios_copy_hw(termios, old);
}
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;
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 */
wait_for_bits(up, UART_LSR_THRE);
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;
struct circ_buf *xmit;
up = container_of(port, struct nwpserial_port, port);
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;
unsigned long flags;
int ret;
up = container_of(port, struct nwpserial_port, port);
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(KERN_ERR "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);
#ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL_CONSOLE
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);
#endif /* CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL_CONSOLE */

19
drivers/serial/of_serial.c
View File

@ -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 +163,10 @@ 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-nwp-serial",
.data = (void *)PORT_NWPSERIAL, },
#endif
{ .type = "serial", .data = (void *)PORT_UNKNOWN, },
{ /* end of list */ },
};

18
include/linux/nwpserial.h Normal file
View File

@ -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 */

3
include/linux/serial_core.h
View File

@ -161,6 +161,9 @@
#define PORT_S3C6400 84
/* NWPSERIAL */
#define PORT_NWPSERIAL 85
#ifdef __KERNEL__
#include <linux/compiler.h>