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linux-sg2042/drivers/serial/dz.c

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/*
* dz.c: Serial port driver for DECstations equipped
* with the DZ chipset.
*
* Copyright (C) 1998 Olivier A. D. Lebaillif
*
* Email: olivier.lebaillif@ifrsys.com
*
* Copyright (C) 2004, 2006 Maciej W. Rozycki
*
* [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
#if defined(CONFIG_SERIAL_DZ_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/sysrq.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>
#include "dz.h"
static char *dz_name = "DECstation DZ serial driver version ";
static char *dz_version = "1.03";
struct dz_port {
struct uart_port port;
unsigned int cflag;
};
static struct dz_port dz_ports[DZ_NB_PORT];
/*
* ------------------------------------------------------------
* 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 | dport->port.line);
spin_unlock_irqrestore(&dport->port.lock, flags);
}
static void dz_enable_ms(struct uart_port *port)
{
/* nothing to do */
}
/*
* ------------------------------------------------------------
*
* Here start 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: dz_interrupt() is a "fast" interrupt, which means that it
* runs with interrupts turned off. People who may want to modify
* dz_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_in)
{
struct dz_port *dport;
struct tty_struct *tty = NULL;
struct uart_icount *icount;
int lines_rx[DZ_NB_PORT] = { [0 ... DZ_NB_PORT - 1] = 0 };
unsigned short status;
unsigned char ch, flag;
int i;
while ((status = dz_in(dport_in, DZ_RBUF)) & DZ_DVAL) {
dport = &dz_ports[LINE(status)];
tty = dport->port.info->tty; /* point to the proper dev */
ch = UCHAR(status); /* grab the char */
icount = &dport->port.icount;
icount->rx++;
flag = TTY_NORMAL;
if (status & DZ_FERR) { /* frame error */
/*
* There is no separate BREAK status bit, so
* treat framing errors as BREAKs for Magic SysRq
* and SAK; normally, otherwise.
*/
if (uart_handle_break(&dport->port))
continue;
if (dport->port.flags & UPF_SAK)
flag = TTY_BREAK;
else
flag = TTY_FRAME;
} else if (status & DZ_OERR) /* overrun error */
flag = TTY_OVERRUN;
else if (status & DZ_PERR) /* parity error */
flag = TTY_PARITY;
/* keep track of the statistics */
switch (flag) {
case TTY_FRAME:
icount->frame++;
break;
case TTY_PARITY:
icount->parity++;
break;
case TTY_OVERRUN:
icount->overrun++;
break;
case TTY_BREAK:
icount->brk++;
break;
default:
break;
}
if (uart_handle_sysrq_char(&dport->port, ch))
continue;
if ((status & dport->port.ignore_status_mask) == 0) {
uart_insert_char(&dport->port,
status, DZ_OERR, ch, flag);
lines_rx[LINE(status)] = 1;
}
}
for (i = 0; i < DZ_NB_PORT; i++)
if (lines_rx[i])
tty_flip_buffer_push(dz_ports[i].port.info->tty);
}
/*
* ------------------------------------------------------------
* transmit_char ()
*
* This routine deals with outputs to any lines.
* ------------------------------------------------------------
*/
static inline void dz_transmit_chars(struct dz_port *dport_in)
{
struct dz_port *dport;
struct circ_buf *xmit;
unsigned short status;
unsigned char tmp;
status = dz_in(dport_in, DZ_CSR);
dport = &dz_ports[LINE(status)];
xmit = &dport->port.info->xmit;
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... (remember 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 are done. */
if (uart_circ_empty(xmit))
dz_stop_tx(&dport->port);
}
/*
* ------------------------------------------------------------
* check_modem_status()
*
* DS 3100 & 5100: Only valid for the MODEM line, duh!
* DS 5000/200: Valid for the MODEM and PRINTER line.
* ------------------------------------------------------------
*/
static inline void check_modem_status(struct dz_port *dport)
{
/*
* FIXME:
* 1. No status change interrupt; use a timer.
* 2. Handle the 3100/5000 as appropriate. --macro
*/
unsigned short status;
/* If not the 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 dz_port *dport = dev;
unsigned short status;
/* get the reason why we just got an irq */
status = dz_in(dport, DZ_CSR);
if ((status & (DZ_RDONE | DZ_RIE)) == (DZ_RDONE | DZ_RIE))
dz_receive_chars(dport);
if ((status & (DZ_TRDY | DZ_TIE)) == (DZ_TRDY | DZ_TIE))
dz_transmit_chars(dport);
return IRQ_HANDLED;
}
/*
* -------------------------------------------------------------------
* Here ends the DZ interrupt routines.
* -------------------------------------------------------------------
*/
static unsigned int dz_get_mctrl(struct uart_port *uport)
{
/*
* FIXME: Handle the 3100/5000 as appropriate. --macro
*/
struct dz_port *dport = (struct dz_port *)uport;
unsigned int mctrl = TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
if (dport->port.line == DZ_MODEM) {
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)
{
/*
* FIXME: Handle the 3100/5000 as appropriate. --macro
*/
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;
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);
}
/*
* -------------------------------------------------------------------
* dz_tx_empty() -- get the transmitter empty status
*
* 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 tmp, mask = 1 << dport->port.line;
tmp = dz_in(dport, DZ_TCR);
tmp &= mask;
return tmp ? 0 : TIOCSER_TEMT;
}
static void dz_break_ctl(struct uart_port *uport, int break_state)
{
/*
* FIXME: Can't access BREAK bits in TDR easily;
* reuse the code for polled TX. --macro
*/
struct dz_port *dport = (struct dz_port *)uport;
unsigned long flags;
unsigned short tmp, mask = 1 << dport->port.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 ktermios *termios,
struct ktermios *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->port.line);
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 = CKSEG1ADDR(KN01_SLOT_BASE + KN01_DZ11);
else
base = CKSEG1ADDR(KN02_SLOT_BASE + KN02_DZ11);
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 = UPIO_MEM;
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);
iob();
/* enable scanning */
dz_out(dport, DZ_CSR, DZ_MSE);
}
#ifdef CONFIG_SERIAL_DZ_CONSOLE
/*
* -------------------------------------------------------------------
* dz_console_putchar() -- transmit a character
*
* Polled transmission. This is tricky. We need to mask transmit
* interrupts so that they do not interfere, enable the transmitter
* for the line requested and then wait till the transmit scanner
* requests data for this line. But it may request data for another
* line first, in which case we have to disable its transmitter and
* repeat waiting till our line pops up. Only then the character may
* be transmitted. Finally, the state of the transmitter mask is
* restored. Welcome to the world of PDP-11!
* -------------------------------------------------------------------
*/
static void dz_console_putchar(struct uart_port *uport, int ch)
{
struct dz_port *dport = (struct dz_port *)uport;
unsigned long flags;
unsigned short csr, tcr, trdy, mask;
int loops = 10000;
spin_lock_irqsave(&dport->port.lock, flags);
csr = dz_in(dport, DZ_CSR);
dz_out(dport, DZ_CSR, csr & ~DZ_TIE);
tcr = dz_in(dport, DZ_TCR);
tcr |= 1 << dport->port.line;
mask = tcr;
dz_out(dport, DZ_TCR, mask);
iob();
spin_unlock_irqrestore(&dport->port.lock, flags);
do {
trdy = dz_in(dport, DZ_CSR);
if (!(trdy & DZ_TRDY))
continue;
trdy = (trdy & DZ_TLINE) >> 8;
if (trdy == dport->port.line)
break;
mask &= ~(1 << trdy);
dz_out(dport, DZ_TCR, mask);
iob();
udelay(2);
} while (loops--);
if (loops) /* Cannot send otherwise. */
dz_out(dport, DZ_TDR, ch);
dz_out(dport, DZ_TCR, tcr);
dz_out(dport, DZ_CSR, csr);
}
/*
* -------------------------------------------------------------------
* 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 *co,
const char *str,
unsigned int count)
{
struct dz_port *dport = &dz_ports[co->index];
#ifdef DEBUG_DZ
prom_printf((char *) str);
#endif
uart_console_write(&dport->port, str, count, dz_console_putchar);
}
static int __init dz_console_setup(struct console *co, char *options)
{
struct dz_port *dport = &dz_ports[co->index];
int baud = 9600;
int bits = 8;
int parity = 'n';
int flow = 'n';
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
dz_reset(dport);
return uart_set_options(&dport->port, co, baud, parity, bits, flow);
}
static struct uart_driver dz_reg;
static struct console dz_sercons = {
.name = "ttyS",
.write = dz_console_print,
.device = uart_console_device,
.setup = dz_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &dz_reg,
};
static int __init dz_serial_console_init(void)
{
if (!IOASIC) {
dz_init_ports();
register_console(&dz_sercons);
return 0;
} else
return -ENXIO;
}
console_initcall(dz_serial_console_init);
#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",
.dev_name = "ttyS",
.major = TTY_MAJOR,
.minor = 64,
.nr = DZ_NB_PORT,
.cons = SERIAL_DZ_CONSOLE,
};
static int __init dz_init(void)
{
int ret, i;
if (IOASIC)
return -ENXIO;
printk("%s%s\n", dz_name, dz_version);
dz_init_ports();
#ifndef CONFIG_SERIAL_DZ_CONSOLE
/* reset the chip */
dz_reset(&dz_ports[0]);
#endif
if (request_irq(dz_ports[0].port.irq, dz_interrupt,
IRQF_DISABLED, "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_init(dz_init);
MODULE_DESCRIPTION("DECstation DZ serial driver");
MODULE_LICENSE("GPL");
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