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WSL2-Linux-Kernel/drivers/tty/amiserial.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Serial driver for the amiga builtin port.
*
* This code was created by taking serial.c version 4.30 from kernel
* release 2.3.22, replacing all hardware related stuff with the
* corresponding amiga hardware actions, and removing all irrelevant
* code. As a consequence, it uses many of the constants and names
* associated with the registers and bits of 16550 compatible UARTS -
* but only to keep track of status, etc in the state variables. It
* was done this was to make it easier to keep the code in line with
* (non hardware specific) changes to serial.c.
*
* The port is registered with the tty driver as minor device 64, and
* therefore other ports should should only use 65 upwards.
*
* Richard Lucock 28/12/99
*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997,
* 1998, 1999 Theodore Ts'o
*
*/
#include <linux/delay.h>
/* Set of debugging defines */
#undef SERIAL_DEBUG_INTR
#undef SERIAL_DEBUG_OPEN
#undef SERIAL_DEBUG_FLOW
#undef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
/* Sanity checks */
#if defined(MODULE) && defined(SERIAL_DEBUG_MCOUNT)
#define DBG_CNT(s) printk("(%s): [%x] refc=%d, serc=%d, ttyc=%d -> %s\n", \
tty->name, (info->tport.flags), serial_driver->refcount,info->count,tty->count,s)
#else
#define DBG_CNT(s)
#endif
/*
* End of serial driver configuration section.
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/serial.h>
#include <linux/serial_reg.h>
static char *serial_version = "4.30";
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/circ_buf.h>
#include <linux/console.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/mm.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/platform_device.h>
#include <asm/setup.h>
#include <asm/irq.h>
#include <asm/amigahw.h>
#include <asm/amigaints.h>
struct serial_state {
struct tty_port tport;
struct circ_buf xmit;
struct async_icount icount;
unsigned long port;
int baud_base;
int xmit_fifo_size;
int custom_divisor;
int read_status_mask;
int ignore_status_mask;
int timeout;
int quot;
int IER; /* Interrupt Enable Register */
int MCR; /* Modem control register */
int x_char; /* xon/xoff character */
};
#define custom amiga_custom
static char *serial_name = "Amiga-builtin serial driver";
static struct tty_driver *serial_driver;
/* number of characters left in xmit buffer before we ask for more */
#define WAKEUP_CHARS 256
static unsigned char current_ctl_bits;
static void change_speed(struct tty_struct *tty, struct serial_state *info,
struct ktermios *old);
static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
static struct serial_state rs_table[1];
#define NR_PORTS ARRAY_SIZE(rs_table)
#include <linux/uaccess.h>
#define serial_isroot() (capable(CAP_SYS_ADMIN))
/* some serial hardware definitions */
#define SDR_OVRUN (1<<15)
#define SDR_RBF (1<<14)
#define SDR_TBE (1<<13)
#define SDR_TSRE (1<<12)
#define SERPER_PARENB (1<<15)
#define AC_SETCLR (1<<15)
#define AC_UARTBRK (1<<11)
#define SER_DTR (1<<7)
#define SER_RTS (1<<6)
#define SER_DCD (1<<5)
#define SER_CTS (1<<4)
#define SER_DSR (1<<3)
static __inline__ void rtsdtr_ctrl(int bits)
{
ciab.pra = ((bits & (SER_RTS | SER_DTR)) ^ (SER_RTS | SER_DTR)) | (ciab.pra & ~(SER_RTS | SER_DTR));
}
/*
* ------------------------------------------------------------
* rs_stop() and rs_start()
*
* This routines are called before setting or resetting tty->flow.stopped.
* They enable or disable transmitter interrupts, as necessary.
* ------------------------------------------------------------
*/
static void rs_stop(struct tty_struct *tty)
{
struct serial_state *info = tty->driver_data;
unsigned long flags;
local_irq_save(flags);
if (info->IER & UART_IER_THRI) {
info->IER &= ~UART_IER_THRI;
/* disable Tx interrupt and remove any pending interrupts */
custom.intena = IF_TBE;
mb();
custom.intreq = IF_TBE;
mb();
}
local_irq_restore(flags);
}
static void rs_start(struct tty_struct *tty)
{
struct serial_state *info = tty->driver_data;
unsigned long flags;
local_irq_save(flags);
if (info->xmit.head != info->xmit.tail
&& info->xmit.buf
&& !(info->IER & UART_IER_THRI)) {
info->IER |= UART_IER_THRI;
custom.intena = IF_SETCLR | IF_TBE;
mb();
/* set a pending Tx Interrupt, transmitter should restart now */
custom.intreq = IF_SETCLR | IF_TBE;
mb();
}
local_irq_restore(flags);
}
/*
* ----------------------------------------------------------------------
*
* Here starts the interrupt handling routines. All of the following
* subroutines are declared as inline and are folded into
* rs_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:
*
* gcc -S -DKERNEL -Wall -Wstrict-prototypes -O6 -fomit-frame-pointer serial.c
*
* and look at the resulting assemble code in serial.s.
*
* - Ted Ts'o (tytso@mit.edu), 7-Mar-93
* -----------------------------------------------------------------------
*/
static void receive_chars(struct serial_state *info)
{
int status;
int serdatr;
unsigned char ch, flag;
struct async_icount *icount;
int oe = 0;
icount = &info->icount;
status = UART_LSR_DR; /* We obviously have a character! */
serdatr = custom.serdatr;
mb();
custom.intreq = IF_RBF;
mb();
if((serdatr & 0x1ff) == 0)
status |= UART_LSR_BI;
if(serdatr & SDR_OVRUN)
status |= UART_LSR_OE;
ch = serdatr & 0xff;
icount->rx++;
#ifdef SERIAL_DEBUG_INTR
printk("DR%02x:%02x...", ch, status);
#endif
flag = TTY_NORMAL;
/*
* We don't handle parity or frame errors - but I have left
* the code in, since I'm not sure that the errors can't be
* detected.
*/
if (status & (UART_LSR_BI | UART_LSR_PE |
UART_LSR_FE | UART_LSR_OE)) {
/*
* For statistics only
*/
if (status & UART_LSR_BI) {
status &= ~(UART_LSR_FE | UART_LSR_PE);
icount->brk++;
} else if (status & UART_LSR_PE)
icount->parity++;
else if (status & UART_LSR_FE)
icount->frame++;
if (status & UART_LSR_OE)
icount->overrun++;
/*
* Now check to see if character should be
* ignored, and mask off conditions which
* should be ignored.
*/
if (status & info->ignore_status_mask)
goto out;
status &= info->read_status_mask;
if (status & (UART_LSR_BI)) {
#ifdef SERIAL_DEBUG_INTR
printk("handling break....");
#endif
flag = TTY_BREAK;
if (info->tport.flags & ASYNC_SAK)
do_SAK(info->tport.tty);
} else if (status & UART_LSR_PE)
flag = TTY_PARITY;
else if (status & UART_LSR_FE)
flag = TTY_FRAME;
if (status & UART_LSR_OE) {
/*
* Overrun is special, since it's
* reported immediately, and doesn't
* affect the current character
*/
oe = 1;
}
}
tty_insert_flip_char(&info->tport, ch, flag);
if (oe == 1)
tty_insert_flip_char(&info->tport, 0, TTY_OVERRUN);
tty_flip_buffer_push(&info->tport);
out:
return;
}
static void transmit_chars(struct serial_state *info)
{
custom.intreq = IF_TBE;
mb();
if (info->x_char) {
custom.serdat = info->x_char | 0x100;
mb();
info->icount.tx++;
info->x_char = 0;
return;
}
if (info->xmit.head == info->xmit.tail
|| info->tport.tty->flow.stopped
|| info->tport.tty->hw_stopped) {
info->IER &= ~UART_IER_THRI;
custom.intena = IF_TBE;
mb();
return;
}
custom.serdat = info->xmit.buf[info->xmit.tail++] | 0x100;
mb();
info->xmit.tail = info->xmit.tail & (SERIAL_XMIT_SIZE-1);
info->icount.tx++;
if (CIRC_CNT(info->xmit.head,
info->xmit.tail,
SERIAL_XMIT_SIZE) < WAKEUP_CHARS)
tty_wakeup(info->tport.tty);
#ifdef SERIAL_DEBUG_INTR
printk("THRE...");
#endif
if (info->xmit.head == info->xmit.tail) {
custom.intena = IF_TBE;
mb();
info->IER &= ~UART_IER_THRI;
}
}
static void check_modem_status(struct serial_state *info)
{
struct tty_port *port = &info->tport;
unsigned char status = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
unsigned char dstatus;
struct async_icount *icount;
/* Determine bits that have changed */
dstatus = status ^ current_ctl_bits;
current_ctl_bits = status;
if (dstatus) {
icount = &info->icount;
/* update input line counters */
if (dstatus & SER_DSR)
icount->dsr++;
if (dstatus & SER_DCD) {
icount->dcd++;
}
if (dstatus & SER_CTS)
icount->cts++;
wake_up_interruptible(&port->delta_msr_wait);
}
if (tty_port_check_carrier(port) && (dstatus & SER_DCD)) {
#if (defined(SERIAL_DEBUG_OPEN) || defined(SERIAL_DEBUG_INTR))
printk("ttyS%d CD now %s...", info->line,
(!(status & SER_DCD)) ? "on" : "off");
#endif
if (!(status & SER_DCD))
wake_up_interruptible(&port->open_wait);
else {
#ifdef SERIAL_DEBUG_OPEN
printk("doing serial hangup...");
#endif
if (port->tty)
tty_hangup(port->tty);
}
}
if (tty_port_cts_enabled(port)) {
if (port->tty->hw_stopped) {
if (!(status & SER_CTS)) {
#if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
printk("CTS tx start...");
#endif
port->tty->hw_stopped = 0;
info->IER |= UART_IER_THRI;
custom.intena = IF_SETCLR | IF_TBE;
mb();
/* set a pending Tx Interrupt, transmitter should restart now */
custom.intreq = IF_SETCLR | IF_TBE;
mb();
tty_wakeup(port->tty);
return;
}
} else {
if ((status & SER_CTS)) {
#if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
printk("CTS tx stop...");
#endif
port->tty->hw_stopped = 1;
info->IER &= ~UART_IER_THRI;
/* disable Tx interrupt and remove any pending interrupts */
custom.intena = IF_TBE;
mb();
custom.intreq = IF_TBE;
mb();
}
}
}
}
static irqreturn_t ser_vbl_int( int irq, void *data)
{
/* vbl is just a periodic interrupt we tie into to update modem status */
struct serial_state *info = data;
/*
* TBD - is it better to unregister from this interrupt or to
* ignore it if MSI is clear ?
*/
if(info->IER & UART_IER_MSI)
check_modem_status(info);
return IRQ_HANDLED;
}
static irqreturn_t ser_rx_int(int irq, void *dev_id)
{
struct serial_state *info = dev_id;
#ifdef SERIAL_DEBUG_INTR
printk("ser_rx_int...");
#endif
if (!info->tport.tty)
return IRQ_NONE;
receive_chars(info);
#ifdef SERIAL_DEBUG_INTR
printk("end.\n");
#endif
return IRQ_HANDLED;
}
static irqreturn_t ser_tx_int(int irq, void *dev_id)
{
struct serial_state *info = dev_id;
if (custom.serdatr & SDR_TBE) {
#ifdef SERIAL_DEBUG_INTR
printk("ser_tx_int...");
#endif
if (!info->tport.tty)
return IRQ_NONE;
transmit_chars(info);
#ifdef SERIAL_DEBUG_INTR
printk("end.\n");
#endif
}
return IRQ_HANDLED;
}
/*
* -------------------------------------------------------------------
* Here ends the serial interrupt routines.
* -------------------------------------------------------------------
*/
/*
* ---------------------------------------------------------------
* Low level utility subroutines for the serial driver: routines to
* figure out the appropriate timeout for an interrupt chain, routines
* to initialize and startup a serial port, and routines to shutdown a
* serial port. Useful stuff like that.
* ---------------------------------------------------------------
*/
static int startup(struct tty_struct *tty, struct serial_state *info)
{
struct tty_port *port = &info->tport;
unsigned long flags;
int retval=0;
unsigned long page;
page = get_zeroed_page(GFP_KERNEL);
if (!page)
return -ENOMEM;
local_irq_save(flags);
if (tty_port_initialized(port)) {
free_page(page);
goto errout;
}
if (info->xmit.buf)
free_page(page);
else
info->xmit.buf = (unsigned char *) page;
#ifdef SERIAL_DEBUG_OPEN
printk("starting up ttys%d ...", info->line);
#endif
/* Clear anything in the input buffer */
custom.intreq = IF_RBF;
mb();
retval = request_irq(IRQ_AMIGA_VERTB, ser_vbl_int, 0, "serial status", info);
if (retval) {
if (serial_isroot()) {
set_bit(TTY_IO_ERROR, &tty->flags);
retval = 0;
}
goto errout;
}
/* enable both Rx and Tx interrupts */
custom.intena = IF_SETCLR | IF_RBF | IF_TBE;
mb();
info->IER = UART_IER_MSI;
/* remember current state of the DCD and CTS bits */
current_ctl_bits = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
info->MCR = 0;
if (C_BAUD(tty))
info->MCR = SER_DTR | SER_RTS;
rtsdtr_ctrl(info->MCR);
clear_bit(TTY_IO_ERROR, &tty->flags);
info->xmit.head = info->xmit.tail = 0;
/*
* and set the speed of the serial port
*/
change_speed(tty, info, NULL);
tty_port_set_initialized(port, 1);
local_irq_restore(flags);
return 0;
errout:
local_irq_restore(flags);
return retval;
}
/*
* 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 shutdown(struct tty_struct *tty, struct serial_state *info)
{
unsigned long flags;
struct serial_state *state;
if (!tty_port_initialized(&info->tport))
return;
state = info;
#ifdef SERIAL_DEBUG_OPEN
printk("Shutting down serial port %d ....\n", info->line);
#endif
local_irq_save(flags); /* Disable interrupts */
/*
* clear delta_msr_wait queue to avoid mem leaks: we may free the irq
* here so the queue might never be waken up
*/
wake_up_interruptible(&info->tport.delta_msr_wait);
/*
* Free the IRQ, if necessary
*/
free_irq(IRQ_AMIGA_VERTB, info);
if (info->xmit.buf) {
free_page((unsigned long) info->xmit.buf);
info->xmit.buf = NULL;
}
info->IER = 0;
custom.intena = IF_RBF | IF_TBE;
mb();
/* disable break condition */
custom.adkcon = AC_UARTBRK;
mb();
if (C_HUPCL(tty))
info->MCR &= ~(SER_DTR|SER_RTS);
rtsdtr_ctrl(info->MCR);
set_bit(TTY_IO_ERROR, &tty->flags);
tty_port_set_initialized(&info->tport, 0);
local_irq_restore(flags);
}
/*
* This routine is called to set the UART divisor registers to match
* the specified baud rate for a serial port.
*/
static void change_speed(struct tty_struct *tty, struct serial_state *info,
struct ktermios *old_termios)
{
struct tty_port *port = &info->tport;
int quot = 0, baud_base, baud;
unsigned cflag, cval = 0;
int bits;
unsigned long flags;
cflag = tty->termios.c_cflag;
/* Byte size is always 8 bits plus parity bit if requested */
cval = 3; bits = 10;
if (cflag & CSTOPB) {
cval |= 0x04;
bits++;
}
if (cflag & PARENB) {
cval |= UART_LCR_PARITY;
bits++;
}
if (!(cflag & PARODD))
cval |= UART_LCR_EPAR;
#ifdef CMSPAR
if (cflag & CMSPAR)
cval |= UART_LCR_SPAR;
#endif
/* Determine divisor based on baud rate */
baud = tty_get_baud_rate(tty);
if (!baud)
baud = 9600; /* B0 transition handled in rs_set_termios */
baud_base = info->baud_base;
if (baud == 38400 && (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
quot = info->custom_divisor;
else {
if (baud == 134)
/* Special case since 134 is really 134.5 */
quot = (2*baud_base / 269);
else if (baud)
quot = baud_base / baud;
}
/* If the quotient is zero refuse the change */
if (!quot && old_termios) {
/* FIXME: Will need updating for new tty in the end */
tty->termios.c_cflag &= ~CBAUD;
tty->termios.c_cflag |= (old_termios->c_cflag & CBAUD);
baud = tty_get_baud_rate(tty);
if (!baud)
baud = 9600;
if (baud == 38400 &&
(port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
quot = info->custom_divisor;
else {
if (baud == 134)
/* Special case since 134 is really 134.5 */
quot = (2*baud_base / 269);
else if (baud)
quot = baud_base / baud;
}
}
/* As a last resort, if the quotient is zero, default to 9600 bps */
if (!quot)
quot = baud_base / 9600;
info->quot = quot;
info->timeout = ((info->xmit_fifo_size*HZ*bits*quot) / baud_base);
info->timeout += HZ/50; /* Add .02 seconds of slop */
/* CTS flow control flag and modem status interrupts */
info->IER &= ~UART_IER_MSI;
if (port->flags & ASYNC_HARDPPS_CD)
info->IER |= UART_IER_MSI;
tty_port_set_cts_flow(port, cflag & CRTSCTS);
if (cflag & CRTSCTS)
info->IER |= UART_IER_MSI;
tty_port_set_check_carrier(port, ~cflag & CLOCAL);
if (~cflag & CLOCAL)
info->IER |= UART_IER_MSI;
/* TBD:
* Does clearing IER_MSI imply that we should disable the VBL interrupt ?
*/
/*
* Set up parity check flag
*/
info->read_status_mask = UART_LSR_OE | UART_LSR_DR;
if (I_INPCK(tty))
info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
if (I_BRKINT(tty) || I_PARMRK(tty))
info->read_status_mask |= UART_LSR_BI;
/*
* Characters to ignore
*/
info->ignore_status_mask = 0;
if (I_IGNPAR(tty))
info->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
if (I_IGNBRK(tty)) {
info->ignore_status_mask |= UART_LSR_BI;
/*
* If we're ignore parity and break indicators, ignore
* overruns too. (For real raw support).
*/
if (I_IGNPAR(tty))
info->ignore_status_mask |= UART_LSR_OE;
}
/*
* !!! ignore all characters if CREAD is not set
*/
if ((cflag & CREAD) == 0)
info->ignore_status_mask |= UART_LSR_DR;
local_irq_save(flags);
{
short serper;
/* Set up the baud rate */
serper = quot - 1;
/* Enable or disable parity bit */
if(cval & UART_LCR_PARITY)
serper |= (SERPER_PARENB);
custom.serper = serper;
mb();
}
local_irq_restore(flags);
}
static int rs_put_char(struct tty_struct *tty, unsigned char ch)
{
struct serial_state *info;
unsigned long flags;
info = tty->driver_data;
if (!info->xmit.buf)
return 0;
local_irq_save(flags);
if (CIRC_SPACE(info->xmit.head,
info->xmit.tail,
SERIAL_XMIT_SIZE) == 0) {
local_irq_restore(flags);
return 0;
}
info->xmit.buf[info->xmit.head++] = ch;
info->xmit.head &= SERIAL_XMIT_SIZE-1;
local_irq_restore(flags);
return 1;
}
static void rs_flush_chars(struct tty_struct *tty)
{
struct serial_state *info = tty->driver_data;
unsigned long flags;
if (info->xmit.head == info->xmit.tail
|| tty->flow.stopped
|| tty->hw_stopped
|| !info->xmit.buf)
return;
local_irq_save(flags);
info->IER |= UART_IER_THRI;
custom.intena = IF_SETCLR | IF_TBE;
mb();
/* set a pending Tx Interrupt, transmitter should restart now */
custom.intreq = IF_SETCLR | IF_TBE;
mb();
local_irq_restore(flags);
}
static int rs_write(struct tty_struct * tty, const unsigned char *buf, int count)
{
int c, ret = 0;
struct serial_state *info = tty->driver_data;
unsigned long flags;
if (!info->xmit.buf)
return 0;
local_irq_save(flags);
while (1) {
c = CIRC_SPACE_TO_END(info->xmit.head,
info->xmit.tail,
SERIAL_XMIT_SIZE);
if (count < c)
c = count;
if (c <= 0) {
break;
}
memcpy(info->xmit.buf + info->xmit.head, buf, c);
info->xmit.head = ((info->xmit.head + c) &
(SERIAL_XMIT_SIZE-1));
buf += c;
count -= c;
ret += c;
}
local_irq_restore(flags);
if (info->xmit.head != info->xmit.tail
&& !tty->flow.stopped
&& !tty->hw_stopped
&& !(info->IER & UART_IER_THRI)) {
info->IER |= UART_IER_THRI;
local_irq_disable();
custom.intena = IF_SETCLR | IF_TBE;
mb();
/* set a pending Tx Interrupt, transmitter should restart now */
custom.intreq = IF_SETCLR | IF_TBE;
mb();
local_irq_restore(flags);
}
return ret;
}
static unsigned int rs_write_room(struct tty_struct *tty)
{
struct serial_state *info = tty->driver_data;
return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
}
static unsigned int rs_chars_in_buffer(struct tty_struct *tty)
{
struct serial_state *info = tty->driver_data;
return CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
}
static void rs_flush_buffer(struct tty_struct *tty)
{
struct serial_state *info = tty->driver_data;
unsigned long flags;
local_irq_save(flags);
info->xmit.head = info->xmit.tail = 0;
local_irq_restore(flags);
tty_wakeup(tty);
}
/*
* This function is used to send a high-priority XON/XOFF character to
* the device
*/
static void rs_send_xchar(struct tty_struct *tty, char ch)
{
struct serial_state *info = tty->driver_data;
unsigned long flags;
info->x_char = ch;
if (ch) {
/* Make sure transmit interrupts are on */
/* Check this ! */
local_irq_save(flags);
if(!(custom.intenar & IF_TBE)) {
custom.intena = IF_SETCLR | IF_TBE;
mb();
/* set a pending Tx Interrupt, transmitter should restart now */
custom.intreq = IF_SETCLR | IF_TBE;
mb();
}
local_irq_restore(flags);
info->IER |= UART_IER_THRI;
}
}
/*
* ------------------------------------------------------------
* rs_throttle()
*
* This routine is called by the upper-layer tty layer to signal that
* incoming characters should be throttled.
* ------------------------------------------------------------
*/
static void rs_throttle(struct tty_struct * tty)
{
struct serial_state *info = tty->driver_data;
unsigned long flags;
#ifdef SERIAL_DEBUG_THROTTLE
printk("throttle %s ....\n", tty_name(tty));
#endif
if (I_IXOFF(tty))
rs_send_xchar(tty, STOP_CHAR(tty));
if (C_CRTSCTS(tty))
info->MCR &= ~SER_RTS;
local_irq_save(flags);
rtsdtr_ctrl(info->MCR);
local_irq_restore(flags);
}
static void rs_unthrottle(struct tty_struct * tty)
{
struct serial_state *info = tty->driver_data;
unsigned long flags;
#ifdef SERIAL_DEBUG_THROTTLE
printk("unthrottle %s ....\n", tty_name(tty));
#endif
if (I_IXOFF(tty)) {
if (info->x_char)
info->x_char = 0;
else
rs_send_xchar(tty, START_CHAR(tty));
}
if (C_CRTSCTS(tty))
info->MCR |= SER_RTS;
local_irq_save(flags);
rtsdtr_ctrl(info->MCR);
local_irq_restore(flags);
}
/*
* ------------------------------------------------------------
* rs_ioctl() and friends
* ------------------------------------------------------------
*/
static int get_serial_info(struct tty_struct *tty, struct serial_struct *ss)
{
struct serial_state *state = tty->driver_data;
unsigned int close_delay, closing_wait;
tty_lock(tty);
close_delay = jiffies_to_msecs(state->tport.close_delay) / 10;
closing_wait = state->tport.closing_wait;
if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
closing_wait = jiffies_to_msecs(closing_wait) / 10;
ss->line = tty->index;
ss->port = state->port;
ss->flags = state->tport.flags;
ss->xmit_fifo_size = state->xmit_fifo_size;
ss->baud_base = state->baud_base;
ss->close_delay = close_delay;
ss->closing_wait = closing_wait;
ss->custom_divisor = state->custom_divisor;
tty_unlock(tty);
return 0;
}
static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss)
{
struct serial_state *state = tty->driver_data;
struct tty_port *port = &state->tport;
bool change_spd;
int retval = 0;
unsigned int close_delay, closing_wait;
tty_lock(tty);
change_spd = ((ss->flags ^ port->flags) & ASYNC_SPD_MASK) ||
ss->custom_divisor != state->custom_divisor;
if (ss->irq || ss->port != state->port ||
ss->xmit_fifo_size != state->xmit_fifo_size) {
tty_unlock(tty);
return -EINVAL;
}
close_delay = msecs_to_jiffies(ss->close_delay * 10);
closing_wait = ss->closing_wait;
if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
closing_wait = msecs_to_jiffies(closing_wait * 10);
if (!serial_isroot()) {
if ((ss->baud_base != state->baud_base) ||
(close_delay != port->close_delay) ||
(closing_wait != port->closing_wait) ||
(ss->xmit_fifo_size != state->xmit_fifo_size) ||
((ss->flags & ~ASYNC_USR_MASK) !=
(port->flags & ~ASYNC_USR_MASK))) {
tty_unlock(tty);
return -EPERM;
}
port->flags = ((port->flags & ~ASYNC_USR_MASK) |
(ss->flags & ASYNC_USR_MASK));
state->custom_divisor = ss->custom_divisor;
goto check_and_exit;
}
if (ss->baud_base < 9600) {
tty_unlock(tty);
return -EINVAL;
}
/*
* OK, past this point, all the error checking has been done.
* At this point, we start making changes.....
*/
state->baud_base = ss->baud_base;
port->flags = ((port->flags & ~ASYNC_FLAGS) |
(ss->flags & ASYNC_FLAGS));
state->custom_divisor = ss->custom_divisor;
port->close_delay = close_delay;
port->closing_wait = closing_wait;
check_and_exit:
if (tty_port_initialized(port)) {
if (change_spd) {
/* warn about deprecation unless clearing */
if (ss->flags & ASYNC_SPD_MASK)
dev_warn_ratelimited(tty->dev, "use of SPD flags is deprecated\n");
change_speed(tty, state, NULL);
}
} else
retval = startup(tty, state);
tty_unlock(tty);
return retval;
}
/*
* 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 int get_lsr_info(struct serial_state *info, unsigned int __user *value)
{
unsigned char status;
unsigned int result;
unsigned long flags;
local_irq_save(flags);
status = custom.serdatr;
mb();
local_irq_restore(flags);
result = ((status & SDR_TSRE) ? TIOCSER_TEMT : 0);
if (copy_to_user(value, &result, sizeof(int)))
return -EFAULT;
return 0;
}
static int rs_tiocmget(struct tty_struct *tty)
{
struct serial_state *info = tty->driver_data;
unsigned char control, status;
unsigned long flags;
if (tty_io_error(tty))
return -EIO;
control = info->MCR;
local_irq_save(flags);
status = ciab.pra;
local_irq_restore(flags);
return ((control & SER_RTS) ? TIOCM_RTS : 0)
| ((control & SER_DTR) ? TIOCM_DTR : 0)
| (!(status & SER_DCD) ? TIOCM_CAR : 0)
| (!(status & SER_DSR) ? TIOCM_DSR : 0)
| (!(status & SER_CTS) ? TIOCM_CTS : 0);
}
static int rs_tiocmset(struct tty_struct *tty, unsigned int set,
unsigned int clear)
{
struct serial_state *info = tty->driver_data;
unsigned long flags;
if (tty_io_error(tty))
return -EIO;
local_irq_save(flags);
if (set & TIOCM_RTS)
info->MCR |= SER_RTS;
if (set & TIOCM_DTR)
info->MCR |= SER_DTR;
if (clear & TIOCM_RTS)
info->MCR &= ~SER_RTS;
if (clear & TIOCM_DTR)
info->MCR &= ~SER_DTR;
rtsdtr_ctrl(info->MCR);
local_irq_restore(flags);
return 0;
}
/*
* rs_break() --- routine which turns the break handling on or off
*/
static int rs_break(struct tty_struct *tty, int break_state)
{
unsigned long flags;
local_irq_save(flags);
if (break_state == -1)
custom.adkcon = AC_SETCLR | AC_UARTBRK;
else
custom.adkcon = AC_UARTBRK;
mb();
local_irq_restore(flags);
return 0;
}
/*
* Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
* Return: write counters to the user passed counter struct
* NB: both 1->0 and 0->1 transitions are counted except for
* RI where only 0->1 is counted.
*/
static int rs_get_icount(struct tty_struct *tty,
struct serial_icounter_struct *icount)
{
struct serial_state *info = tty->driver_data;
struct async_icount cnow;
unsigned long flags;
local_irq_save(flags);
cnow = info->icount;
local_irq_restore(flags);
icount->cts = cnow.cts;
icount->dsr = cnow.dsr;
icount->rng = cnow.rng;
icount->dcd = cnow.dcd;
icount->rx = cnow.rx;
icount->tx = cnow.tx;
icount->frame = cnow.frame;
icount->overrun = cnow.overrun;
icount->parity = cnow.parity;
icount->brk = cnow.brk;
icount->buf_overrun = cnow.buf_overrun;
return 0;
}
static int rs_ioctl(struct tty_struct *tty,
unsigned int cmd, unsigned long arg)
{
struct serial_state *info = tty->driver_data;
struct async_icount cprev, cnow; /* kernel counter temps */
void __user *argp = (void __user *)arg;
unsigned long flags;
DEFINE_WAIT(wait);
int ret;
if ((cmd != TIOCSERCONFIG) &&
(cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
if (tty_io_error(tty))
return -EIO;
}
switch (cmd) {
case TIOCSERCONFIG:
return 0;
case TIOCSERGETLSR: /* Get line status register */
return get_lsr_info(info, argp);
/*
* Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
* - mask passed in arg for lines of interest
* (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
* Caller should use TIOCGICOUNT to see which one it was
*/
case TIOCMIWAIT:
local_irq_save(flags);
/* note the counters on entry */
cprev = info->icount;
local_irq_restore(flags);
while (1) {
prepare_to_wait(&info->tport.delta_msr_wait,
&wait, TASK_INTERRUPTIBLE);
local_irq_save(flags);
cnow = info->icount; /* atomic copy */
local_irq_restore(flags);
if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
cnow.dcd == cprev.dcd && cnow.cts == cprev.cts) {
ret = -EIO; /* no change => error */
break;
}
if ( ((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
ret = 0;
break;
}
schedule();
/* see if a signal did it */
if (signal_pending(current)) {
ret = -ERESTARTSYS;
break;
}
cprev = cnow;
}
finish_wait(&info->tport.delta_msr_wait, &wait);
return ret;
default:
return -ENOIOCTLCMD;
}
return 0;
}
static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
{
struct serial_state *info = tty->driver_data;
unsigned long flags;
unsigned int cflag = tty->termios.c_cflag;
change_speed(tty, info, old_termios);
/* Handle transition to B0 status */
if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD)) {
info->MCR &= ~(SER_DTR|SER_RTS);
local_irq_save(flags);
rtsdtr_ctrl(info->MCR);
local_irq_restore(flags);
}
/* Handle transition away from B0 status */
if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
info->MCR |= SER_DTR;
if (!C_CRTSCTS(tty) || !tty_throttled(tty))
info->MCR |= SER_RTS;
local_irq_save(flags);
rtsdtr_ctrl(info->MCR);
local_irq_restore(flags);
}
/* Handle turning off CRTSCTS */
if ((old_termios->c_cflag & CRTSCTS) && !C_CRTSCTS(tty)) {
tty->hw_stopped = 0;
rs_start(tty);
}
#if 0
/*
* No need to wake up processes in open wait, since they
* sample the CLOCAL flag once, and don't recheck it.
* XXX It's not clear whether the current behavior is correct
* or not. Hence, this may change.....
*/
if (!(old_termios->c_cflag & CLOCAL) && C_CLOCAL(tty))
wake_up_interruptible(&info->open_wait);
#endif
}
/*
* ------------------------------------------------------------
* rs_close()
*
* This routine is called when the serial port gets closed. First, we
* wait for the last remaining data to be sent. Then, we unlink its
* async structure from the interrupt chain if necessary, and we free
* that IRQ if nothing is left in the chain.
* ------------------------------------------------------------
*/
static void rs_close(struct tty_struct *tty, struct file * filp)
{
struct serial_state *state = tty->driver_data;
struct tty_port *port = &state->tport;
if (tty_port_close_start(port, tty, filp) == 0)
return;
/*
* At this point we stop accepting input. To do this, we
* disable the receive line status interrupts, and tell the
* interrupt driver to stop checking the data ready bit in the
* line status register.
*/
state->read_status_mask &= ~UART_LSR_DR;
if (tty_port_initialized(port)) {
/* disable receive interrupts */
custom.intena = IF_RBF;
mb();
/* clear any pending receive interrupt */
custom.intreq = IF_RBF;
mb();
/*
* Before we drop DTR, make sure the UART transmitter
* has completely drained; this is especially
* important if there is a transmit FIFO!
*/
rs_wait_until_sent(tty, state->timeout);
}
shutdown(tty, state);
rs_flush_buffer(tty);
tty_ldisc_flush(tty);
port->tty = NULL;
tty_port_close_end(port, tty);
}
/*
* rs_wait_until_sent() --- wait until the transmitter is empty
*/
static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
{
struct serial_state *info = tty->driver_data;
unsigned long orig_jiffies, char_time;
int lsr;
if (info->xmit_fifo_size == 0)
return; /* Just in case.... */
orig_jiffies = jiffies;
/*
* Set the check interval to be 1/5 of the estimated time to
* send a single character, and make it at least 1. The check
* interval should also be less than the timeout.
*
* Note: we have to use pretty tight timings here to satisfy
* the NIST-PCTS.
*/
char_time = (info->timeout - HZ/50) / info->xmit_fifo_size;
char_time = char_time / 5;
if (char_time == 0)
char_time = 1;
if (timeout)
char_time = min_t(unsigned long, char_time, timeout);
/*
* If the transmitter hasn't cleared in twice the approximate
* amount of time to send the entire FIFO, it probably won't
* ever clear. This assumes the UART isn't doing flow
* control, which is currently the case. Hence, if it ever
* takes longer than info->timeout, this is probably due to a
* UART bug of some kind. So, we clamp the timeout parameter at
* 2*info->timeout.
*/
if (!timeout || timeout > 2*info->timeout)
timeout = 2*info->timeout;
#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
printk("In rs_wait_until_sent(%d) check=%lu...", timeout, char_time);
printk("jiff=%lu...", jiffies);
#endif
while(!((lsr = custom.serdatr) & SDR_TSRE)) {
#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
printk("serdatr = %d (jiff=%lu)...", lsr, jiffies);
#endif
msleep_interruptible(jiffies_to_msecs(char_time));
if (signal_pending(current))
break;
if (timeout && time_after(jiffies, orig_jiffies + timeout))
break;
}
__set_current_state(TASK_RUNNING);
#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
#endif
}
/*
* rs_hangup() --- called by tty_hangup() when a hangup is signaled.
*/
static void rs_hangup(struct tty_struct *tty)
{
struct serial_state *info = tty->driver_data;
rs_flush_buffer(tty);
shutdown(tty, info);
info->tport.count = 0;
tty_port_set_active(&info->tport, 0);
info->tport.tty = NULL;
wake_up_interruptible(&info->tport.open_wait);
}
/*
* This routine is called whenever a serial port is opened. It
* enables interrupts for a serial port, linking in its async structure into
* the IRQ chain. It also performs the serial-specific
* initialization for the tty structure.
*/
static int rs_open(struct tty_struct *tty, struct file * filp)
{
struct serial_state *info = rs_table + tty->index;
struct tty_port *port = &info->tport;
int retval;
port->count++;
port->tty = tty;
tty->driver_data = info;
tty->port = port;
retval = startup(tty, info);
if (retval) {
return retval;
}
return tty_port_block_til_ready(port, tty, filp);
}
/*
* /proc fs routines....
*/
static inline void line_info(struct seq_file *m, int line,
struct serial_state *state)
{
char stat_buf[30], control, status;
unsigned long flags;
seq_printf(m, "%d: uart:amiga_builtin", line);
local_irq_save(flags);
status = ciab.pra;
control = tty_port_initialized(&state->tport) ? state->MCR : status;
local_irq_restore(flags);
stat_buf[0] = 0;
stat_buf[1] = 0;
if(!(control & SER_RTS))
strcat(stat_buf, "|RTS");
if(!(status & SER_CTS))
strcat(stat_buf, "|CTS");
if(!(control & SER_DTR))
strcat(stat_buf, "|DTR");
if(!(status & SER_DSR))
strcat(stat_buf, "|DSR");
if(!(status & SER_DCD))
strcat(stat_buf, "|CD");
if (state->quot)
seq_printf(m, " baud:%d", state->baud_base / state->quot);
seq_printf(m, " tx:%d rx:%d", state->icount.tx, state->icount.rx);
if (state->icount.frame)
seq_printf(m, " fe:%d", state->icount.frame);
if (state->icount.parity)
seq_printf(m, " pe:%d", state->icount.parity);
if (state->icount.brk)
seq_printf(m, " brk:%d", state->icount.brk);
if (state->icount.overrun)
seq_printf(m, " oe:%d", state->icount.overrun);
/*
* Last thing is the RS-232 status lines
*/
seq_printf(m, " %s\n", stat_buf+1);
}
static int rs_proc_show(struct seq_file *m, void *v)
{
seq_printf(m, "serinfo:1.0 driver:%s\n", serial_version);
line_info(m, 0, &rs_table[0]);
return 0;
}
/*
* ---------------------------------------------------------------------
* rs_init() and friends
*
* rs_init() is called at boot-time to initialize the serial driver.
* ---------------------------------------------------------------------
*/
/*
* This routine prints out the appropriate serial driver version
* number, and identifies which options were configured into this
* driver.
*/
static void show_serial_version(void)
{
printk(KERN_INFO "%s version %s\n", serial_name, serial_version);
}
static const struct tty_operations serial_ops = {
.open = rs_open,
.close = rs_close,
.write = rs_write,
.put_char = rs_put_char,
.flush_chars = rs_flush_chars,
.write_room = rs_write_room,
.chars_in_buffer = rs_chars_in_buffer,
.flush_buffer = rs_flush_buffer,
.ioctl = rs_ioctl,
.throttle = rs_throttle,
.unthrottle = rs_unthrottle,
.set_termios = rs_set_termios,
.stop = rs_stop,
.start = rs_start,
.hangup = rs_hangup,
.break_ctl = rs_break,
.send_xchar = rs_send_xchar,
.wait_until_sent = rs_wait_until_sent,
.tiocmget = rs_tiocmget,
.tiocmset = rs_tiocmset,
.get_icount = rs_get_icount,
.set_serial = set_serial_info,
.get_serial = get_serial_info,
.proc_show = rs_proc_show,
};
static int amiga_carrier_raised(struct tty_port *port)
{
return !(ciab.pra & SER_DCD);
}
static void amiga_dtr_rts(struct tty_port *port, int raise)
{
struct serial_state *info = container_of(port, struct serial_state,
tport);
unsigned long flags;
if (raise)
info->MCR |= SER_DTR|SER_RTS;
else
info->MCR &= ~(SER_DTR|SER_RTS);
local_irq_save(flags);
rtsdtr_ctrl(info->MCR);
local_irq_restore(flags);
}
static const struct tty_port_operations amiga_port_ops = {
.carrier_raised = amiga_carrier_raised,
.dtr_rts = amiga_dtr_rts,
};
/*
* The serial driver boot-time initialization code!
*/
static int __init amiga_serial_probe(struct platform_device *pdev)
{
unsigned long flags;
struct serial_state * state;
int error;
serial_driver = alloc_tty_driver(NR_PORTS);
if (!serial_driver)
return -ENOMEM;
show_serial_version();
/* Initialize the tty_driver structure */
serial_driver->driver_name = "amiserial";
serial_driver->name = "ttyS";
serial_driver->major = TTY_MAJOR;
serial_driver->minor_start = 64;
serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
serial_driver->subtype = SERIAL_TYPE_NORMAL;
serial_driver->init_termios = tty_std_termios;
serial_driver->init_termios.c_cflag =
B9600 | CS8 | CREAD | HUPCL | CLOCAL;
serial_driver->flags = TTY_DRIVER_REAL_RAW;
tty_set_operations(serial_driver, &serial_ops);
state = rs_table;
state->port = (int)&custom.serdatr; /* Just to give it a value */
state->custom_divisor = 0;
state->icount.cts = state->icount.dsr =
state->icount.rng = state->icount.dcd = 0;
state->icount.rx = state->icount.tx = 0;
state->icount.frame = state->icount.parity = 0;
state->icount.overrun = state->icount.brk = 0;
tty_port_init(&state->tport);
state->tport.ops = &amiga_port_ops;
tty_port_link_device(&state->tport, serial_driver, 0);
error = tty_register_driver(serial_driver);
if (error)
goto fail_put_tty_driver;
printk(KERN_INFO "ttyS0 is the amiga builtin serial port\n");
/* Hardware set up */
state->baud_base = amiga_colorclock;
state->xmit_fifo_size = 1;
/* set ISRs, and then disable the rx interrupts */
error = request_irq(IRQ_AMIGA_TBE, ser_tx_int, 0, "serial TX", state);
if (error)
goto fail_unregister;
error = request_irq(IRQ_AMIGA_RBF, ser_rx_int, 0,
"serial RX", state);
if (error)
goto fail_free_irq;
local_irq_save(flags);
/* turn off Rx and Tx interrupts */
custom.intena = IF_RBF | IF_TBE;
mb();
/* clear any pending interrupt */
custom.intreq = IF_RBF | IF_TBE;
mb();
local_irq_restore(flags);
/*
* set the appropriate directions for the modem control flags,
* and clear RTS and DTR
*/
ciab.ddra |= (SER_DTR | SER_RTS); /* outputs */
ciab.ddra &= ~(SER_DCD | SER_CTS | SER_DSR); /* inputs */
platform_set_drvdata(pdev, state);
return 0;
fail_free_irq:
free_irq(IRQ_AMIGA_TBE, state);
fail_unregister:
tty_unregister_driver(serial_driver);
fail_put_tty_driver:
tty_port_destroy(&state->tport);
put_tty_driver(serial_driver);
return error;
}
static int __exit amiga_serial_remove(struct platform_device *pdev)
{
struct serial_state *state = platform_get_drvdata(pdev);
/* printk("Unloading %s: version %s\n", serial_name, serial_version); */
tty_unregister_driver(serial_driver);
put_tty_driver(serial_driver);
tty_port_destroy(&state->tport);
free_irq(IRQ_AMIGA_TBE, state);
free_irq(IRQ_AMIGA_RBF, state);
return 0;
}
static struct platform_driver amiga_serial_driver = {
.remove = __exit_p(amiga_serial_remove),
.driver = {
.name = "amiga-serial",
},
};
module_platform_driver_probe(amiga_serial_driver, amiga_serial_probe);
#if defined(CONFIG_SERIAL_CONSOLE) && !defined(MODULE)
/*
* ------------------------------------------------------------
* Serial console driver
* ------------------------------------------------------------
*/
static void amiga_serial_putc(char c)
{
custom.serdat = (unsigned char)c | 0x100;
while (!(custom.serdatr & 0x2000))
barrier();
}
/*
* Print a string to the serial port trying not to disturb
* any possible real use of the port...
*
* The console must be locked when we get here.
*/
static void serial_console_write(struct console *co, const char *s,
unsigned count)
{
unsigned short intena = custom.intenar;
custom.intena = IF_TBE;
while (count--) {
if (*s == '\n')
amiga_serial_putc('\r');
amiga_serial_putc(*s++);
}
custom.intena = IF_SETCLR | (intena & IF_TBE);
}
static struct tty_driver *serial_console_device(struct console *c, int *index)
{
*index = 0;
return serial_driver;
}
static struct console sercons = {
.name = "ttyS",
.write = serial_console_write,
.device = serial_console_device,
.flags = CON_PRINTBUFFER,
.index = -1,
};
/*
* Register console.
*/
static int __init amiserial_console_init(void)
{
if (!MACH_IS_AMIGA)
return -ENODEV;
register_console(&sercons);
return 0;
}
console_initcall(amiserial_console_init);
#endif /* CONFIG_SERIAL_CONSOLE && !MODULE */
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:amiga-serial");
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