[PATCH] serial uartlite driver

Add a driver for the Xilinx uartlite serial controller used in boards with
the PPC405 core in the Xilinx V2P/V4 fpgas.

The hardware is very simple (baudrate/start/stopbits fixed and no break
support).  See the datasheet for details:

	http://www.xilinx.com/bvdocs/ipcenter/data_sheet/opb_uartlite.pdf

See http://thread.gmane.org/gmane.linux.serial/1237/ for the email thread.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Acked-by: Olof Johansson <olof@lixom.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Peter Korsgaard 2006-12-06 20:35:17 -08:00 committed by Linus Torvalds
parent 57881dd9df
commit 238b8721a5
5 changed files with 533 additions and 0 deletions

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@ -3454,6 +3454,12 @@ W: http://oss.sgi.com/projects/xfs
T: git git://oss.sgi.com:8090/xfs/xfs-2.6 T: git git://oss.sgi.com:8090/xfs/xfs-2.6
S: Supported S: Supported
XILINX UARTLITE SERIAL DRIVER
P: Peter Korsgaard
M: jacmet@sunsite.dk
L: linux-serial@vger.kernel.org
S: Maintained
X86 3-LEVEL PAGING (PAE) SUPPORT X86 3-LEVEL PAGING (PAE) SUPPORT
P: Ingo Molnar P: Ingo Molnar
M: mingo@redhat.com M: mingo@redhat.com

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@ -511,6 +511,25 @@ config SERIAL_IMX_CONSOLE
your boot loader (lilo or loadlin) about how to pass options to the your boot loader (lilo or loadlin) about how to pass options to the
kernel at boot time.) kernel at boot time.)
config SERIAL_UARTLITE
tristate "Xilinx uartlite serial port support"
depends on PPC32
select SERIAL_CORE
help
Say Y here if you want to use the Xilinx uartlite serial controller.
To compile this driver as a module, choose M here: the
module will be called uartlite.ko.
config SERIAL_UARTLITE_CONSOLE
bool "Support for console on Xilinx uartlite serial port"
depends on SERIAL_UARTLITE=y
select SERIAL_CORE_CONSOLE
help
Say Y here if you wish to use a Xilinx uartlite as the system
console (the system console is the device which receives all kernel
messages and warnings and which allows logins in single user mode).
config SERIAL_SUNCORE config SERIAL_SUNCORE
bool bool
depends on SPARC depends on SPARC

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@ -55,4 +55,5 @@ obj-$(CONFIG_SERIAL_VR41XX) += vr41xx_siu.o
obj-$(CONFIG_SERIAL_SGI_IOC4) += ioc4_serial.o obj-$(CONFIG_SERIAL_SGI_IOC4) += ioc4_serial.o
obj-$(CONFIG_SERIAL_SGI_IOC3) += ioc3_serial.o obj-$(CONFIG_SERIAL_SGI_IOC3) += ioc3_serial.o
obj-$(CONFIG_SERIAL_ATMEL) += atmel_serial.o obj-$(CONFIG_SERIAL_ATMEL) += atmel_serial.o
obj-$(CONFIG_SERIAL_UARTLITE) += uartlite.o
obj-$(CONFIG_SERIAL_NETX) += netx-serial.o obj-$(CONFIG_SERIAL_NETX) += netx-serial.o

505
drivers/serial/uartlite.c Normal file
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@ -0,0 +1,505 @@
/*
* uartlite.c: Serial driver for Xilinx uartlite serial controller
*
* Peter Korsgaard <jacmet@sunsite.dk>
*
* This file is licensed under the terms of the GNU General Public License
* version 2. This program is licensed "as is" without any warranty of any
* kind, whether express or implied.
*/
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/console.h>
#include <linux/serial.h>
#include <linux/serial_core.h>
#include <linux/tty.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <asm/io.h>
#define ULITE_MAJOR 204
#define ULITE_MINOR 187
#define ULITE_NR_UARTS 4
/* For register details see datasheet:
http://www.xilinx.com/bvdocs/ipcenter/data_sheet/opb_uartlite.pdf
*/
#define ULITE_RX 0x00
#define ULITE_TX 0x04
#define ULITE_STATUS 0x08
#define ULITE_CONTROL 0x0c
#define ULITE_REGION 16
#define ULITE_STATUS_RXVALID 0x01
#define ULITE_STATUS_RXFULL 0x02
#define ULITE_STATUS_TXEMPTY 0x04
#define ULITE_STATUS_TXFULL 0x08
#define ULITE_STATUS_IE 0x10
#define ULITE_STATUS_OVERRUN 0x20
#define ULITE_STATUS_FRAME 0x40
#define ULITE_STATUS_PARITY 0x80
#define ULITE_CONTROL_RST_TX 0x01
#define ULITE_CONTROL_RST_RX 0x02
#define ULITE_CONTROL_IE 0x10
static struct uart_port ports[ULITE_NR_UARTS];
static int ulite_receive(struct uart_port *port, int stat)
{
struct tty_struct *tty = port->info->tty;
unsigned char ch = 0;
char flag = TTY_NORMAL;
if ((stat & (ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN
| ULITE_STATUS_FRAME)) == 0)
return 0;
/* stats */
if (stat & ULITE_STATUS_RXVALID) {
port->icount.rx++;
ch = readb(port->membase + ULITE_RX);
if (stat & ULITE_STATUS_PARITY)
port->icount.parity++;
}
if (stat & ULITE_STATUS_OVERRUN)
port->icount.overrun++;
if (stat & ULITE_STATUS_FRAME)
port->icount.frame++;
/* drop byte with parity error if IGNPAR specificed */
if (stat & port->ignore_status_mask & ULITE_STATUS_PARITY)
stat &= ~ULITE_STATUS_RXVALID;
stat &= port->read_status_mask;
if (stat & ULITE_STATUS_PARITY)
flag = TTY_PARITY;
stat &= ~port->ignore_status_mask;
if (stat & ULITE_STATUS_RXVALID)
tty_insert_flip_char(tty, ch, flag);
if (stat & ULITE_STATUS_FRAME)
tty_insert_flip_char(tty, 0, TTY_FRAME);
if (stat & ULITE_STATUS_OVERRUN)
tty_insert_flip_char(tty, 0, TTY_OVERRUN);
return 1;
}
static int ulite_transmit(struct uart_port *port, int stat)
{
struct circ_buf *xmit = &port->info->xmit;
if (stat & ULITE_STATUS_TXFULL)
return 0;
if (port->x_char) {
writeb(port->x_char, port->membase + ULITE_TX);
port->x_char = 0;
port->icount.tx++;
return 1;
}
if (uart_circ_empty(xmit) || uart_tx_stopped(port))
return 0;
writeb(xmit->buf[xmit->tail], port->membase + ULITE_TX);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE-1);
port->icount.tx++;
/* wake up */
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
return 1;
}
static irqreturn_t ulite_isr(int irq, void *dev_id)
{
struct uart_port *port = (struct uart_port *)dev_id;
int busy;
do {
int stat = readb(port->membase + ULITE_STATUS);
busy = ulite_receive(port, stat);
busy |= ulite_transmit(port, stat);
} while (busy);
tty_flip_buffer_push(port->info->tty);
return IRQ_HANDLED;
}
static unsigned int ulite_tx_empty(struct uart_port *port)
{
unsigned long flags;
unsigned int ret;
spin_lock_irqsave(&port->lock, flags);
ret = readb(port->membase + ULITE_STATUS);
spin_unlock_irqrestore(&port->lock, flags);
return ret & ULITE_STATUS_TXEMPTY ? TIOCSER_TEMT : 0;
}
static unsigned int ulite_get_mctrl(struct uart_port *port)
{
return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
}
static void ulite_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
/* N/A */
}
static void ulite_stop_tx(struct uart_port *port)
{
/* N/A */
}
static void ulite_start_tx(struct uart_port *port)
{
ulite_transmit(port, readb(port->membase + ULITE_STATUS));
}
static void ulite_stop_rx(struct uart_port *port)
{
/* don't forward any more data (like !CREAD) */
port->ignore_status_mask = ULITE_STATUS_RXVALID | ULITE_STATUS_PARITY
| ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
}
static void ulite_enable_ms(struct uart_port *port)
{
/* N/A */
}
static void ulite_break_ctl(struct uart_port *port, int ctl)
{
/* N/A */
}
static int ulite_startup(struct uart_port *port)
{
int ret;
ret = request_irq(port->irq, ulite_isr,
IRQF_DISABLED | IRQF_SAMPLE_RANDOM, "uartlite", port);
if (ret)
return ret;
writeb(ULITE_CONTROL_RST_RX | ULITE_CONTROL_RST_TX,
port->membase + ULITE_CONTROL);
writeb(ULITE_CONTROL_IE, port->membase + ULITE_CONTROL);
return 0;
}
static void ulite_shutdown(struct uart_port *port)
{
writeb(0, port->membase + ULITE_CONTROL);
readb(port->membase + ULITE_CONTROL); /* dummy */
free_irq(port->irq, port);
}
static void ulite_set_termios(struct uart_port *port, struct termios *termios,
struct termios *old)
{
unsigned long flags;
unsigned int baud;
spin_lock_irqsave(&port->lock, flags);
port->read_status_mask = ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN
| ULITE_STATUS_TXFULL;
if (termios->c_iflag & INPCK)
port->read_status_mask |=
ULITE_STATUS_PARITY | ULITE_STATUS_FRAME;
port->ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= ULITE_STATUS_PARITY
| ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
/* ignore all characters if CREAD is not set */
if ((termios->c_cflag & CREAD) == 0)
port->ignore_status_mask |=
ULITE_STATUS_RXVALID | ULITE_STATUS_PARITY
| ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
/* update timeout */
baud = uart_get_baud_rate(port, termios, old, 0, 460800);
uart_update_timeout(port, termios->c_cflag, baud);
spin_unlock_irqrestore(&port->lock, flags);
}
static const char *ulite_type(struct uart_port *port)
{
return port->type == PORT_UARTLITE ? "uartlite" : NULL;
}
static void ulite_release_port(struct uart_port *port)
{
release_mem_region(port->mapbase, ULITE_REGION);
iounmap(port->membase);
port->membase = 0;
}
static int ulite_request_port(struct uart_port *port)
{
if (!request_mem_region(port->mapbase, ULITE_REGION, "uartlite")) {
dev_err(port->dev, "Memory region busy\n");
return -EBUSY;
}
port->membase = ioremap(port->mapbase, ULITE_REGION);
if (!port->membase) {
dev_err(port->dev, "Unable to map registers\n");
release_mem_region(port->mapbase, ULITE_REGION);
return -EBUSY;
}
return 0;
}
static void ulite_config_port(struct uart_port *port, int flags)
{
ulite_request_port(port);
port->type = PORT_UARTLITE;
}
static int ulite_verify_port(struct uart_port *port, struct serial_struct *ser)
{
/* we don't want the core code to modify any port params */
return -EINVAL;
}
static struct uart_ops ulite_ops = {
.tx_empty = ulite_tx_empty,
.set_mctrl = ulite_set_mctrl,
.get_mctrl = ulite_get_mctrl,
.stop_tx = ulite_stop_tx,
.start_tx = ulite_start_tx,
.stop_rx = ulite_stop_rx,
.enable_ms = ulite_enable_ms,
.break_ctl = ulite_break_ctl,
.startup = ulite_startup,
.shutdown = ulite_shutdown,
.set_termios = ulite_set_termios,
.type = ulite_type,
.release_port = ulite_release_port,
.request_port = ulite_request_port,
.config_port = ulite_config_port,
.verify_port = ulite_verify_port
};
#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
static void ulite_console_wait_tx(struct uart_port *port)
{
int i;
/* wait up to 10ms for the character(s) to be sent */
for (i = 0; i < 10000; i++) {
if (readb(port->membase + ULITE_STATUS) & ULITE_STATUS_TXEMPTY)
break;
udelay(1);
}
}
static void ulite_console_putchar(struct uart_port *port, int ch)
{
ulite_console_wait_tx(port);
writeb(ch, port->membase + ULITE_TX);
}
static void ulite_console_write(struct console *co, const char *s,
unsigned int count)
{
struct uart_port *port = &ports[co->index];
unsigned long flags;
unsigned int ier;
int locked = 1;
if (oops_in_progress) {
locked = spin_trylock_irqsave(&port->lock, flags);
} else
spin_lock_irqsave(&port->lock, flags);
/* save and disable interrupt */
ier = readb(port->membase + ULITE_STATUS) & ULITE_STATUS_IE;
writeb(0, port->membase + ULITE_CONTROL);
uart_console_write(port, s, count, ulite_console_putchar);
ulite_console_wait_tx(port);
/* restore interrupt state */
if (ier)
writeb(ULITE_CONTROL_IE, port->membase + ULITE_CONTROL);
if (locked)
spin_unlock_irqrestore(&port->lock, flags);
}
static int __init ulite_console_setup(struct console *co, char *options)
{
struct uart_port *port;
int baud = 9600;
int bits = 8;
int parity = 'n';
int flow = 'n';
if (co->index < 0 || co->index >= ULITE_NR_UARTS)
return -EINVAL;
port = &ports[co->index];
/* not initialized yet? */
if (!port->membase)
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 ulite_uart_driver;
static struct console ulite_console = {
.name = "ttyUL",
.write = ulite_console_write,
.device = uart_console_device,
.setup = ulite_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1, /* Specified on the cmdline (e.g. console=ttyUL0 ) */
.data = &ulite_uart_driver,
};
static int __init ulite_console_init(void)
{
register_console(&ulite_console);
return 0;
}
console_initcall(ulite_console_init);
#endif /* CONFIG_SERIAL_UARTLITE_CONSOLE */
static struct uart_driver ulite_uart_driver = {
.owner = THIS_MODULE,
.driver_name = "uartlite",
.dev_name = "ttyUL",
.major = ULITE_MAJOR,
.minor = ULITE_MINOR,
.nr = ULITE_NR_UARTS,
#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
.cons = &ulite_console,
#endif
};
static int __devinit ulite_probe(struct platform_device *pdev)
{
struct resource *res, *res2;
struct uart_port *port;
if (pdev->id < 0 || pdev->id >= ULITE_NR_UARTS)
return -EINVAL;
if (ports[pdev->id].membase)
return -EBUSY;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -ENODEV;
res2 = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (!res2)
return -ENODEV;
port = &ports[pdev->id];
port->fifosize = 16;
port->regshift = 2;
port->iotype = UPIO_MEM;
port->iobase = 1; /* mark port in use */
port->mapbase = res->start;
port->membase = 0;
port->ops = &ulite_ops;
port->irq = res2->start;
port->flags = UPF_BOOT_AUTOCONF;
port->dev = &pdev->dev;
port->type = PORT_UNKNOWN;
port->line = pdev->id;
uart_add_one_port(&ulite_uart_driver, port);
platform_set_drvdata(pdev, port);
return 0;
}
static int ulite_remove(struct platform_device *pdev)
{
struct uart_port *port = platform_get_drvdata(pdev);
platform_set_drvdata(pdev, NULL);
if (port)
uart_remove_one_port(&ulite_uart_driver, port);
/* mark port as free */
port->membase = 0;
return 0;
}
static struct platform_driver ulite_platform_driver = {
.probe = ulite_probe,
.remove = ulite_remove,
.driver = {
.owner = THIS_MODULE,
.name = "uartlite",
},
};
int __init ulite_init(void)
{
int ret;
ret = uart_register_driver(&ulite_uart_driver);
if (ret)
return ret;
ret = platform_driver_register(&ulite_platform_driver);
if (ret)
uart_unregister_driver(&ulite_uart_driver);
return ret;
}
void __exit ulite_exit(void)
{
platform_driver_unregister(&ulite_platform_driver);
uart_unregister_driver(&ulite_uart_driver);
}
module_init(ulite_init);
module_exit(ulite_exit);
MODULE_AUTHOR("Peter Korsgaard <jacmet@sunsite.dk>");
MODULE_DESCRIPTION("Xilinx uartlite serial driver");
MODULE_LICENSE("GPL");

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@ -132,6 +132,8 @@
#define PORT_S3C2412 73 #define PORT_S3C2412 73
/* Xilinx uartlite */
#define PORT_UARTLITE 74
#ifdef __KERNEL__ #ifdef __KERNEL__