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linux/drivers/serial/dz.c

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/*
* dz.c: Serial port driver for DECStations equiped
* with the DZ chipset.
*
* Copyright (C) 1998 Olivier A. D. Lebaillif
*
* Email: olivier.lebaillif@ifrsys.com
*
* [31-AUG-98] triemer
* Changed IRQ to use Harald's dec internals interrupts.h
* removed base_addr code - moving address assignment to setup.c
* Changed name of dz_init to rs_init to be consistent with tc code
* [13-NOV-98] triemer fixed code to receive characters
* after patches by harald to irq code.
* [09-JAN-99] triemer minor fix for schedule - due to removal of timeout
* field from "current" - somewhere between 2.1.121 and 2.1.131
Qua Jun 27 15:02:26 BRT 2001
* [27-JUN-2001] Arnaldo Carvalho de Melo <acme@conectiva.com.br> - cleanups
*
* Parts (C) 1999 David Airlie, airlied@linux.ie
* [07-SEP-99] Bugfixes
*
* [06-Jan-2002] Russell King <rmk@arm.linux.org.uk>
* Converted to new serial core
*/
#undef DEBUG_DZ
#include <linux/config.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <asm/bootinfo.h>
#include <asm/dec/interrupts.h>
#include <asm/dec/kn01.h>
#include <asm/dec/kn02.h>
#include <asm/dec/machtype.h>
#include <asm/dec/prom.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#define CONSOLE_LINE (3) /* for definition of struct console */
#include "dz.h"
#define DZ_INTR_DEBUG 1
static char *dz_name = "DECstation DZ serial driver version ";
static char *dz_version = "1.02";
struct dz_port {
struct uart_port port;
unsigned int cflag;
};
static struct dz_port dz_ports[DZ_NB_PORT];
#ifdef DEBUG_DZ
/*
* debugging code to send out chars via prom
*/
static void debug_console(const char *s, int count)
{
unsigned i;
for (i = 0; i < count; i++) {
if (*s == 10)
prom_printf("%c", 13);
prom_printf("%c", *s++);
}
}
#endif
/*
* ------------------------------------------------------------
* dz_in () and dz_out ()
*
* These routines are used to access the registers of the DZ
* chip, hiding relocation differences between implementation.
* ------------------------------------------------------------
*/
static inline unsigned short dz_in(struct dz_port *dport, unsigned offset)
{
volatile unsigned short *addr =
(volatile unsigned short *) (dport->port.membase + offset);
return *addr;
}
static inline void dz_out(struct dz_port *dport, unsigned offset,
unsigned short value)
{
volatile unsigned short *addr =
(volatile unsigned short *) (dport->port.membase + offset);
*addr = value;
}
/*
* ------------------------------------------------------------
* rs_stop () and rs_start ()
*
* These routines are called before setting or resetting
* tty->stopped. They enable or disable transmitter interrupts,
* as necessary.
* ------------------------------------------------------------
*/
static void dz_stop_tx(struct uart_port *uport)
{
struct dz_port *dport = (struct dz_port *)uport;
unsigned short tmp, mask = 1 << dport->port.line;
unsigned long flags;
spin_lock_irqsave(&dport->port.lock, flags);
tmp = dz_in(dport, DZ_TCR); /* read the TX flag */
tmp &= ~mask; /* clear the TX flag */
dz_out(dport, DZ_TCR, tmp);
spin_unlock_irqrestore(&dport->port.lock, flags);
}
static void dz_start_tx(struct uart_port *uport)
{
struct dz_port *dport = (struct dz_port *)uport;
unsigned short tmp, mask = 1 << dport->port.line;
unsigned long flags;
spin_lock_irqsave(&dport->port.lock, flags);
tmp = dz_in(dport, DZ_TCR); /* read the TX flag */
tmp |= mask; /* set the TX flag */
dz_out(dport, DZ_TCR, tmp);
spin_unlock_irqrestore(&dport->port.lock, flags);
}
static void dz_stop_rx(struct uart_port *uport)
{
struct dz_port *dport = (struct dz_port *)uport;
unsigned long flags;
spin_lock_irqsave(&dport->port.lock, flags);
dport->cflag &= ~DZ_CREAD;
dz_out(dport, DZ_LPR, dport->cflag);
spin_unlock_irqrestore(&dport->port.lock, flags);
}
static void dz_enable_ms(struct uart_port *port)
{
/* nothing to do */
}
/*
* ------------------------------------------------------------
* Here starts the interrupt handling routines. All of the
* following subroutines are declared as inline and are folded
* into dz_interrupt. They were separated out for readability's
* sake.
*
* Note: rs_interrupt() is a "fast" interrupt, which means that it
* runs with interrupts turned off. People who may want to modify
* rs_interrupt() should try to keep the interrupt handler as fast as
* possible. After you are done making modifications, it is not a bad
* idea to do:
*
* make drivers/serial/dz.s
*
* and look at the resulting assemble code in dz.s.
*
* ------------------------------------------------------------
*/
/*
* ------------------------------------------------------------
* receive_char ()
*
* This routine deals with inputs from any lines.
* ------------------------------------------------------------
*/
static inline void dz_receive_chars(struct dz_port *dport)
{
struct tty_struct *tty = NULL;
struct uart_icount *icount;
int ignore = 0;
unsigned short status, tmp;
unsigned char ch, flag;
/* this code is going to be a problem...
the call to tty_flip_buffer is going to need
to be rethought...
*/
do {
status = dz_in(dport, DZ_RBUF);
/* punt so we don't get duplicate characters */
if (!(status & DZ_DVAL))
goto ignore_char;
ch = UCHAR(status); /* grab the char */
flag = TTY_NORMAL;
#if 0
if (info->is_console) {
if (ch == 0)
return; /* it's a break ... */
}
#endif
tty = dport->port.info->tty;/* now tty points to the proper dev */
icount = &dport->port.icount;
if (!tty)
break;
if (tty->flip.count >= TTY_FLIPBUF_SIZE)
break;
icount->rx++;
/* keep track of the statistics */
if (status & (DZ_OERR | DZ_FERR | DZ_PERR)) {
if (status & DZ_PERR) /* parity error */
icount->parity++;
else if (status & DZ_FERR) /* frame error */
icount->frame++;
if (status & DZ_OERR) /* overrun error */
icount->overrun++;
/* check to see if we should ignore the character
and mask off conditions that should be ignored
*/
if (status & dport->port.ignore_status_mask) {
if (++ignore > 100)
break;
goto ignore_char;
}
/* mask off the error conditions we want to ignore */
tmp = status & dport->port.read_status_mask;
if (tmp & DZ_PERR) {
flag = TTY_PARITY;
#ifdef DEBUG_DZ
debug_console("PERR\n", 5);
#endif
} else if (tmp & DZ_FERR) {
flag = TTY_FRAME;
#ifdef DEBUG_DZ
debug_console("FERR\n", 5);
#endif
}
if (tmp & DZ_OERR) {
#ifdef DEBUG_DZ
debug_console("OERR\n", 5);
#endif
tty_insert_flip_char(tty, ch, flag);
ch = 0;
flag = TTY_OVERRUN;
}
}
tty_insert_flip_char(tty, ch, flag);
ignore_char:
} while (status & DZ_DVAL);
if (tty)
tty_flip_buffer_push(tty);
}
/*
* ------------------------------------------------------------
* transmit_char ()
*
* This routine deals with outputs to any lines.
* ------------------------------------------------------------
*/
static inline void dz_transmit_chars(struct dz_port *dport)
{
struct circ_buf *xmit = &dport->port.info->xmit;
unsigned char tmp;
if (dport->port.x_char) { /* XON/XOFF chars */
dz_out(dport, DZ_TDR, dport->port.x_char);
dport->port.icount.tx++;
dport->port.x_char = 0;
return;
}
/* if nothing to do or stopped or hardware stopped */
if (uart_circ_empty(xmit) || uart_tx_stopped(&dport->port)) {
dz_stop_tx(&dport->port);
return;
}
/*
* if something to do ... (rember the dz has no output fifo so we go
* one char at a time :-<
*/
tmp = xmit->buf[xmit->tail];
xmit->tail = (xmit->tail + 1) & (DZ_XMIT_SIZE - 1);
dz_out(dport, DZ_TDR, tmp);
dport->port.icount.tx++;
if (uart_circ_chars_pending(xmit) < DZ_WAKEUP_CHARS)
uart_write_wakeup(&dport->port);
/* Are we done */
if (uart_circ_empty(xmit))
dz_stop_tx(&dport->port);
}
/*
* ------------------------------------------------------------
* check_modem_status ()
*
* Only valid for the MODEM line duh !
* ------------------------------------------------------------
*/
static inline void check_modem_status(struct dz_port *dport)
{
unsigned short status;
/* if not ne modem line just return */
if (dport->port.line != DZ_MODEM)
return;
status = dz_in(dport, DZ_MSR);
/* it's easy, since DSR2 is the only bit in the register */
if (status)
dport->port.icount.dsr++;
}
/*
* ------------------------------------------------------------
* dz_interrupt ()
*
* this is the main interrupt routine for the DZ chip.
* It deals with the multiple ports.
* ------------------------------------------------------------
*/
static irqreturn_t dz_interrupt(int irq, void *dev, struct pt_regs *regs)
{
struct dz_port *dport;
unsigned short status;
/* get the reason why we just got an irq */
status = dz_in((struct dz_port *)dev, DZ_CSR);
dport = &dz_ports[LINE(status)];
if (status & DZ_RDONE)
dz_receive_chars(dport);
if (status & DZ_TRDY)
dz_transmit_chars(dport);
/* FIXME: what about check modem status??? --rmk */
return IRQ_HANDLED;
}
/*
* -------------------------------------------------------------------
* Here ends the DZ interrupt routines.
* -------------------------------------------------------------------
*/
static unsigned int dz_get_mctrl(struct uart_port *uport)
{
struct dz_port *dport = (struct dz_port *)uport;
unsigned int mctrl = TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
if (dport->port.line == DZ_MODEM) {
/*
* CHECKME: This is a guess from the other code... --rmk
*/
if (dz_in(dport, DZ_MSR) & DZ_MODEM_DSR)
mctrl &= ~TIOCM_DSR;
}
return mctrl;
}
static void dz_set_mctrl(struct uart_port *uport, unsigned int mctrl)
{
struct dz_port *dport = (struct dz_port *)uport;
unsigned short tmp;
if (dport->port.line == DZ_MODEM) {
tmp = dz_in(dport, DZ_TCR);
if (mctrl & TIOCM_DTR)
tmp &= ~DZ_MODEM_DTR;
else
tmp |= DZ_MODEM_DTR;
dz_out(dport, DZ_TCR, tmp);
}
}
/*
* -------------------------------------------------------------------
* startup ()
*
* various initialization tasks
* -------------------------------------------------------------------
*/
static int dz_startup(struct uart_port *uport)
{
struct dz_port *dport = (struct dz_port *)uport;
unsigned long flags;
unsigned short tmp;
/* The dz lines for the mouse/keyboard must be
* opened using their respective drivers.
*/
if ((dport->port.line == DZ_KEYBOARD) ||
(dport->port.line == DZ_MOUSE))
return -ENODEV;
spin_lock_irqsave(&dport->port.lock, flags);
/* enable the interrupt and the scanning */
tmp = dz_in(dport, DZ_CSR);
tmp |= DZ_RIE | DZ_TIE | DZ_MSE;
dz_out(dport, DZ_CSR, tmp);
spin_unlock_irqrestore(&dport->port.lock, flags);
return 0;
}
/*
* -------------------------------------------------------------------
* shutdown ()
*
* This routine will shutdown a serial port; interrupts are disabled, and
* DTR is dropped if the hangup on close termio flag is on.
* -------------------------------------------------------------------
*/
static void dz_shutdown(struct uart_port *uport)
{
dz_stop_tx(uport);
}
/*
* get_lsr_info - get line status register info
*
* Purpose: Let user call ioctl() to get info when the UART physically
* is emptied. On bus types like RS485, the transmitter must
* release the bus after transmitting. This must be done when
* the transmit shift register is empty, not be done when the
* transmit holding register is empty. This functionality
* allows an RS485 driver to be written in user space.
*/
static unsigned int dz_tx_empty(struct uart_port *uport)
{
struct dz_port *dport = (struct dz_port *)uport;
unsigned short status = dz_in(dport, DZ_LPR);
/* FIXME: this appears to be obviously broken --rmk. */
return status ? TIOCSER_TEMT : 0;
}
static void dz_break_ctl(struct uart_port *uport, int break_state)
{
struct dz_port *dport = (struct dz_port *)uport;
unsigned long flags;
unsigned short tmp, mask = 1 << uport->line;
spin_lock_irqsave(&uport->lock, flags);
tmp = dz_in(dport, DZ_TCR);
if (break_state)
tmp |= mask;
else
tmp &= ~mask;
dz_out(dport, DZ_TCR, tmp);
spin_unlock_irqrestore(&uport->lock, flags);
}
static void dz_set_termios(struct uart_port *uport, struct termios *termios,
struct termios *old_termios)
{
struct dz_port *dport = (struct dz_port *)uport;
unsigned long flags;
unsigned int cflag, baud;
cflag = dport->port.line;
switch (termios->c_cflag & CSIZE) {
case CS5:
cflag |= DZ_CS5;
break;
case CS6:
cflag |= DZ_CS6;
break;
case CS7:
cflag |= DZ_CS7;
break;
case CS8:
default:
cflag |= DZ_CS8;
}
if (termios->c_cflag & CSTOPB)
cflag |= DZ_CSTOPB;
if (termios->c_cflag & PARENB)
cflag |= DZ_PARENB;
if (termios->c_cflag & PARODD)
cflag |= DZ_PARODD;
baud = uart_get_baud_rate(uport, termios, old_termios, 50, 9600);
switch (baud) {
case 50:
cflag |= DZ_B50;
break;
case 75:
cflag |= DZ_B75;
break;
case 110:
cflag |= DZ_B110;
break;
case 134:
cflag |= DZ_B134;
break;
case 150:
cflag |= DZ_B150;
break;
case 300:
cflag |= DZ_B300;
break;
case 600:
cflag |= DZ_B600;
break;
case 1200:
cflag |= DZ_B1200;
break;
case 1800:
cflag |= DZ_B1800;
break;
case 2000:
cflag |= DZ_B2000;
break;
case 2400:
cflag |= DZ_B2400;
break;
case 3600:
cflag |= DZ_B3600;
break;
case 4800:
cflag |= DZ_B4800;
break;
case 7200:
cflag |= DZ_B7200;
break;
case 9600:
default:
cflag |= DZ_B9600;
}
if (termios->c_cflag & CREAD)
cflag |= DZ_RXENAB;
spin_lock_irqsave(&dport->port.lock, flags);
dz_out(dport, DZ_LPR, cflag);
dport->cflag = cflag;
/* setup accept flag */
dport->port.read_status_mask = DZ_OERR;
if (termios->c_iflag & INPCK)
dport->port.read_status_mask |= DZ_FERR | DZ_PERR;
/* characters to ignore */
uport->ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
dport->port.ignore_status_mask |= DZ_FERR | DZ_PERR;
spin_unlock_irqrestore(&dport->port.lock, flags);
}
static const char *dz_type(struct uart_port *port)
{
return "DZ";
}
static void dz_release_port(struct uart_port *port)
{
/* nothing to do */
}
static int dz_request_port(struct uart_port *port)
{
return 0;
}
static void dz_config_port(struct uart_port *port, int flags)
{
if (flags & UART_CONFIG_TYPE)
port->type = PORT_DZ;
}
/*
* verify the new serial_struct (for TIOCSSERIAL).
*/
static int dz_verify_port(struct uart_port *port, struct serial_struct *ser)
{
int ret = 0;
if (ser->type != PORT_UNKNOWN && ser->type != PORT_DZ)
ret = -EINVAL;
if (ser->irq != port->irq)
ret = -EINVAL;
return ret;
}
static struct uart_ops dz_ops = {
.tx_empty = dz_tx_empty,
.get_mctrl = dz_get_mctrl,
.set_mctrl = dz_set_mctrl,
.stop_tx = dz_stop_tx,
.start_tx = dz_start_tx,
.stop_rx = dz_stop_rx,
.enable_ms = dz_enable_ms,
.break_ctl = dz_break_ctl,
.startup = dz_startup,
.shutdown = dz_shutdown,
.set_termios = dz_set_termios,
.type = dz_type,
.release_port = dz_release_port,
.request_port = dz_request_port,
.config_port = dz_config_port,
.verify_port = dz_verify_port,
};
static void __init dz_init_ports(void)
{
static int first = 1;
struct dz_port *dport;
unsigned long base;
int i;
if (!first)
return;
first = 0;
if (mips_machtype == MACH_DS23100 ||
mips_machtype == MACH_DS5100)
base = (unsigned long) KN01_DZ11_BASE;
else
base = (unsigned long) KN02_DZ11_BASE;
for (i = 0, dport = dz_ports; i < DZ_NB_PORT; i++, dport++) {
spin_lock_init(&dport->port.lock);
dport->port.membase = (char *) base;
dport->port.iotype = SERIAL_IO_PORT;
dport->port.irq = dec_interrupt[DEC_IRQ_DZ11];
dport->port.line = i;
dport->port.fifosize = 1;
dport->port.ops = &dz_ops;
dport->port.flags = UPF_BOOT_AUTOCONF;
}
}
static void dz_reset(struct dz_port *dport)
{
dz_out(dport, DZ_CSR, DZ_CLR);
while (dz_in(dport, DZ_CSR) & DZ_CLR);
/* FIXME: cpu_relax? */
iob();
/* enable scanning */
dz_out(dport, DZ_CSR, DZ_MSE);
}
#ifdef CONFIG_SERIAL_DZ_CONSOLE
static void dz_console_put_char(struct dz_port *dport, unsigned char ch)
{
unsigned long flags;
int loops = 2500;
unsigned short tmp = ch;
/* this code sends stuff out to serial device - spinning its
wheels and waiting. */
spin_lock_irqsave(&dport->port.lock, flags);
/* spin our wheels */
while (((dz_in(dport, DZ_CSR) & DZ_TRDY) != DZ_TRDY) && loops--)
/* FIXME: cpu_relax, udelay? --rmk */
;
/* Actually transmit the character. */
dz_out(dport, DZ_TDR, tmp);
spin_unlock_irqrestore(&dport->port.lock, flags);
}
/*
* -------------------------------------------------------------------
* dz_console_print ()
*
* dz_console_print is registered for printk.
* The console must be locked when we get here.
* -------------------------------------------------------------------
*/
static void dz_console_print(struct console *cons,
const char *str,
unsigned int count)
{
struct dz_port *dport = &dz_ports[CONSOLE_LINE];
#ifdef DEBUG_DZ
prom_printf((char *) str);
#endif
while (count--) {
if (*str == '\n')
dz_console_put_char(dport, '\r');
dz_console_put_char(dport, *str++);
}
}
static int __init dz_console_setup(struct console *co, char *options)
{
struct dz_port *dport = &dz_ports[CONSOLE_LINE];
int baud = 9600;
int bits = 8;
int parity = 'n';
int flow = 'n';
int ret;
unsigned short mask, tmp;
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
dz_reset(dport);
ret = uart_set_options(&dport->port, co, baud, parity, bits, flow);
if (ret == 0) {
mask = 1 << dport->port.line;
tmp = dz_in(dport, DZ_TCR); /* read the TX flag */
if (!(tmp & mask)) {
tmp |= mask; /* set the TX flag */
dz_out(dport, DZ_TCR, tmp);
}
}
return ret;
}
static struct console dz_sercons =
{
.name = "ttyS",
.write = dz_console_print,
.device = uart_console_device,
.setup = dz_console_setup,
.flags = CON_CONSDEV | CON_PRINTBUFFER,
.index = CONSOLE_LINE,
};
void __init dz_serial_console_init(void)
{
dz_init_ports();
register_console(&dz_sercons);
}
#define SERIAL_DZ_CONSOLE &dz_sercons
#else
#define SERIAL_DZ_CONSOLE NULL
#endif /* CONFIG_SERIAL_DZ_CONSOLE */
static struct uart_driver dz_reg = {
.owner = THIS_MODULE,
.driver_name = "serial",
#ifdef CONFIG_DEVFS
.dev_name = "tts/%d",
#else
.dev_name = "ttyS%d",
#endif
.major = TTY_MAJOR,
.minor = 64,
.nr = DZ_NB_PORT,
.cons = SERIAL_DZ_CONSOLE,
};
int __init dz_init(void)
{
unsigned long flags;
int ret, i;
printk("%s%s\n", dz_name, dz_version);
dz_init_ports();
save_flags(flags);
cli();
#ifndef CONFIG_SERIAL_DZ_CONSOLE
/* reset the chip */
dz_reset(&dz_ports[0]);
#endif
/* order matters here... the trick is that flags
is updated... in request_irq - to immediatedly obliterate
it is unwise. */
restore_flags(flags);
if (request_irq(dz_ports[0].port.irq, dz_interrupt,
SA_INTERRUPT, "DZ", &dz_ports[0]))
panic("Unable to register DZ interrupt");
ret = uart_register_driver(&dz_reg);
if (ret != 0)
return ret;
for (i = 0; i < DZ_NB_PORT; i++)
uart_add_one_port(&dz_reg, &dz_ports[i].port);
return ret;
}
MODULE_DESCRIPTION("DECstation DZ serial driver");
MODULE_LICENSE("GPL");
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