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linux/drivers/net/wan/pc300_tty.c
Alan Cox 33f0f88f1c [PATCH] TTY layer buffering revamp 
The API and code have been through various bits of initial review by
serial driver people but they definitely need to live somewhere for a
while so the unconverted drivers can get knocked into shape, existing
drivers that have been updated can be better tuned and bugs whacked out.

This replaces the tty flip buffers with kmalloc objects in rings. In the
normal situation for an IRQ driven serial port at typical speeds the
behaviour is pretty much the same, two buffers end up allocated and the
kernel cycles between them as before.

When there are delays or at high speed we now behave far better as the
buffer pool can grow a bit rather than lose characters. This also means
that we can operate at higher speeds reliably.

For drivers that receive characters in blocks (DMA based, USB and
especially virtualisation) the layer allows a lot of driver specific
code that works around the tty layer with private secondary queues to be
removed. The IBM folks need this sort of layer, the smart serial port
people do, the virtualisers do (because a virtualised tty typically
operates at infinite speed rather than emulating 9600 baud).

Finally many drivers had invalid and unsafe attempts to avoid buffer
overflows by directly invoking tty methods extracted out of the innards
of work queue structs. These are no longer needed and all go away. That
fixes various random hangs with serial ports on overflow.

The other change in here is to optimise the receive_room path that is
used by some callers. It turns out that only one ldisc uses receive room
except asa constant and it updates it far far less than the value is
read. We thus make it a variable not a function call.

I expect the code to contain bugs due to the size alone but I'll be
watching and squashing them and feeding out new patches as it goes.

Because the buffers now dynamically expand you should only run out of
buffering when the kernel runs out of memory for real.  That means a lot of
the horrible hacks high performance drivers used to do just aren't needed any
more.

Description:

tty_insert_flip_char is an old API and continues to work as before, as does
tty_flip_buffer_push() [this is why many drivers dont need modification].  It
does now also return the number of chars inserted

There are also

tty_buffer_request_room(tty, len)

which asks for a buffer block of the length requested and returns the space
found.  This improves efficiency with hardware that knows how much to
transfer.

and tty_insert_flip_string_flags(tty, str, flags, len)

to insert a string of characters and flags

For a smart interface the usual code is

    len = tty_request_buffer_room(tty, amount_hardware_says);
    tty_insert_flip_string(tty, buffer_from_card, len);

More description!

At the moment tty buffers are attached directly to the tty.  This is causing a
lot of the problems related to tty layer locking, also problems at high speed
and also with bursty data (such as occurs in virtualised environments)

I'm working on ripping out the flip buffers and replacing them with a pool of
dynamically allocated buffers.  This allows both for old style "byte I/O"
devices and also helps virtualisation and smart devices where large blocks of
data suddenely materialise and need storing.

So far so good.  Lots of drivers reference tty->flip.*.  Several of them also
call directly and unsafely into function pointers it provides.  This will all
break.  Most drivers can use tty_insert_flip_char which can be kept as an API
but others need more.

At the moment I've added the following interfaces, if people think more will
be needed now is a good time to say

 int tty_buffer_request_room(tty, size)

Try and ensure at least size bytes are available, returns actual room (may be
zero).  At the moment it just uses the flipbuf space but that will change.
Repeated calls without characters being added are not cumulative.  (ie if you
call it with 1, 1, 1, and then 4 you'll have four characters of space.  The
other functions will also try and grow buffers in future but this will be a
more efficient way when you know block sizes.

 int tty_insert_flip_char(tty, ch, flag)

As before insert a character if there is room.  Now returns 1 for success, 0
for failure.

 int tty_insert_flip_string(tty, str, len)

Insert a block of non error characters.  Returns the number inserted.

 int tty_prepare_flip_string(tty, strptr, len)

Adjust the buffer to allow len characters to be added.  Returns a buffer
pointer in strptr and the length available.  This allows for hardware that
needs to use functions like insl or mencpy_fromio.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10 08:01:59 -08:00

1091 lines
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/*
* pc300_tty.c Cyclades-PC300(tm) TTY Driver.
*
* Author: Regina Kodato <reginak@cyclades.com>
*
* Copyright: (c) 1999-2002 Cyclades Corp.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* $Log: pc300_tty.c,v $
* Revision 3.7 2002/03/07 14:17:09 henrique
* License data fixed
*
* Revision 3.6 2001/12/10 12:29:42 regina
* Fix the MLPPP bug
*
* Revision 3.5 2001/10/31 11:20:05 regina
* automatic pppd starts
*
* Revision 3.4 2001/08/06 12:01:51 regina
* problem in DSR_DE bit
*
* Revision 3.3 2001/07/26 22:58:41 regina
* update EDA value
*
* Revision 3.2 2001/07/12 13:11:20 regina
* bug fix - DCD-OFF in pc300 tty driver
*
* DMA transmission bug fix
*
* Revision 3.1 2001/06/22 13:13:02 regina
* MLPPP implementation
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/if.h>
#include <linux/skbuff.h>
/* TTY includes */
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include "pc300.h"
/* defines and macros */
/* TTY Global definitions */
#define CPC_TTY_NPORTS 8 /* maximum number of the sync tty connections */
#define CPC_TTY_MAJOR CYCLADES_MAJOR
#define CPC_TTY_MINOR_START 240 /* minor of the first PC300 interface */
#define CPC_TTY_MAX_MTU 2000
/* tty interface state */
#define CPC_TTY_ST_IDLE 0
#define CPC_TTY_ST_INIT 1 /* configured with MLPPP and up */
#define CPC_TTY_ST_OPEN 2 /* opened by application */
#define CPC_TTY_LOCK(card,flags)\
do {\
spin_lock_irqsave(&card->card_lock, flags); \
} while (0)
#define CPC_TTY_UNLOCK(card,flags) \
do {\
spin_unlock_irqrestore(&card->card_lock, flags); \
} while (0)
//#define CPC_TTY_DBG(format,a...) printk(format,##a)
#define CPC_TTY_DBG(format,a...)
/* data structures */
typedef struct _st_cpc_rx_buf {
struct _st_cpc_rx_buf *next;
int size;
unsigned char data[1];
} st_cpc_rx_buf;
struct st_cpc_rx_list {
st_cpc_rx_buf *first;
st_cpc_rx_buf *last;
};
typedef struct _st_cpc_tty_area {
int state; /* state of the TTY interface */
int num_open;
unsigned int tty_minor; /* minor this interface */
volatile struct st_cpc_rx_list buf_rx; /* ptr. to reception buffer */
unsigned char* buf_tx; /* ptr. to transmission buffer */
pc300dev_t* pc300dev; /* ptr. to info struct in PC300 driver */
unsigned char name[20]; /* interf. name + "-tty" */
struct tty_struct *tty;
struct work_struct tty_tx_work; /* tx work - tx interrupt */
struct work_struct tty_rx_work; /* rx work - rx interrupt */
} st_cpc_tty_area;
/* TTY data structures */
static struct tty_driver serial_drv;
/* local variables */
static st_cpc_tty_area cpc_tty_area[CPC_TTY_NPORTS];
static int cpc_tty_cnt = 0; /* number of intrfaces configured with MLPPP */
static int cpc_tty_unreg_flag = 0;
/* TTY functions prototype */
static int cpc_tty_open(struct tty_struct *tty, struct file *flip);
static void cpc_tty_close(struct tty_struct *tty, struct file *flip);
static int cpc_tty_write(struct tty_struct *tty, const unsigned char *buf, int count);
static int cpc_tty_write_room(struct tty_struct *tty);
static int cpc_tty_chars_in_buffer(struct tty_struct *tty);
static void cpc_tty_flush_buffer(struct tty_struct *tty);
static void cpc_tty_hangup(struct tty_struct *tty);
static void cpc_tty_rx_work(void *data);
static void cpc_tty_tx_work(void *data);
static int cpc_tty_send_to_card(pc300dev_t *dev,void *buf, int len);
static void cpc_tty_trace(pc300dev_t *dev, char* buf, int len, char rxtx);
static void cpc_tty_signal_off(pc300dev_t *pc300dev, unsigned char);
static void cpc_tty_signal_on(pc300dev_t *pc300dev, unsigned char);
static int pc300_tiocmset(struct tty_struct *, struct file *,
unsigned int, unsigned int);
static int pc300_tiocmget(struct tty_struct *, struct file *);
/* functions called by PC300 driver */
void cpc_tty_init(pc300dev_t *dev);
void cpc_tty_unregister_service(pc300dev_t *pc300dev);
void cpc_tty_receive(pc300dev_t *pc300dev);
void cpc_tty_trigger_poll(pc300dev_t *pc300dev);
void cpc_tty_reset_var(void);
/*
* PC300 TTY clear "signal"
*/
static void cpc_tty_signal_off(pc300dev_t *pc300dev, unsigned char signal)
{
pc300ch_t *pc300chan = (pc300ch_t *)pc300dev->chan;
pc300_t *card = (pc300_t *) pc300chan->card;
int ch = pc300chan->channel;
unsigned long flags;
CPC_TTY_DBG("%s-tty: Clear signal %x\n",
pc300dev->dev->name, signal);
CPC_TTY_LOCK(card, flags);
cpc_writeb(card->hw.scabase + M_REG(CTL,ch),
cpc_readb(card->hw.scabase+M_REG(CTL,ch))& signal);
CPC_TTY_UNLOCK(card,flags);
}
/*
* PC300 TTY set "signal" to ON
*/
static void cpc_tty_signal_on(pc300dev_t *pc300dev, unsigned char signal)
{
pc300ch_t *pc300chan = (pc300ch_t *)pc300dev->chan;
pc300_t *card = (pc300_t *) pc300chan->card;
int ch = pc300chan->channel;
unsigned long flags;
CPC_TTY_DBG("%s-tty: Set signal %x\n",
pc300dev->dev->name, signal);
CPC_TTY_LOCK(card, flags);
cpc_writeb(card->hw.scabase + M_REG(CTL,ch),
cpc_readb(card->hw.scabase+M_REG(CTL,ch))& ~signal);
CPC_TTY_UNLOCK(card,flags);
}
/*
* PC300 TTY initialization routine
*
* This routine is called by the PC300 driver during board configuration
* (ioctl=SIOCSP300CONF). At this point the adapter is completely
* initialized.
* o verify kernel version (only 2.4.x)
* o register TTY driver
* o init cpc_tty_area struct
*/
void cpc_tty_init(pc300dev_t *pc300dev)
{
unsigned long port;
int aux;
st_cpc_tty_area * cpc_tty;
/* hdlcX - X=interface number */
port = pc300dev->dev->name[4] - '0';
if (port >= CPC_TTY_NPORTS) {
printk("%s-tty: invalid interface selected (0-%i): %li",
pc300dev->dev->name,
CPC_TTY_NPORTS-1,port);
return;
}
if (cpc_tty_cnt == 0) { /* first TTY connection -> register driver */
CPC_TTY_DBG("%s-tty: driver init, major:%i, minor range:%i=%i\n",
pc300dev->dev->name,
CPC_TTY_MAJOR, CPC_TTY_MINOR_START,
CPC_TTY_MINOR_START+CPC_TTY_NPORTS);
/* initialize tty driver struct */
memset(&serial_drv,0,sizeof(struct tty_driver));
serial_drv.magic = TTY_DRIVER_MAGIC;
serial_drv.owner = THIS_MODULE;
serial_drv.driver_name = "pc300_tty";
serial_drv.name = "ttyCP";
serial_drv.major = CPC_TTY_MAJOR;
serial_drv.minor_start = CPC_TTY_MINOR_START;
serial_drv.num = CPC_TTY_NPORTS;
serial_drv.type = TTY_DRIVER_TYPE_SERIAL;
serial_drv.subtype = SERIAL_TYPE_NORMAL;
serial_drv.init_termios = tty_std_termios;
serial_drv.init_termios.c_cflag = B9600|CS8|CREAD|HUPCL|CLOCAL;
serial_drv.flags = TTY_DRIVER_REAL_RAW;
/* interface routines from the upper tty layer to the tty driver */
serial_drv.open = cpc_tty_open;
serial_drv.close = cpc_tty_close;
serial_drv.write = cpc_tty_write;
serial_drv.write_room = cpc_tty_write_room;
serial_drv.chars_in_buffer = cpc_tty_chars_in_buffer;
serial_drv.tiocmset = pc300_tiocmset;
serial_drv.tiocmget = pc300_tiocmget;
serial_drv.flush_buffer = cpc_tty_flush_buffer;
serial_drv.hangup = cpc_tty_hangup;
/* register the TTY driver */
if (tty_register_driver(&serial_drv)) {
printk("%s-tty: Failed to register serial driver! ",
pc300dev->dev->name);
return;
}
memset((void *)cpc_tty_area, 0,
sizeof(st_cpc_tty_area) * CPC_TTY_NPORTS);
}
cpc_tty = &cpc_tty_area[port];
if (cpc_tty->state != CPC_TTY_ST_IDLE) {
CPC_TTY_DBG("%s-tty: TTY port %i, already in use.\n",
pc300dev->dev->name, port);
return;
}
cpc_tty_cnt++;
cpc_tty->state = CPC_TTY_ST_INIT;
cpc_tty->num_open= 0;
cpc_tty->tty_minor = port + CPC_TTY_MINOR_START;
cpc_tty->pc300dev = pc300dev;
INIT_WORK(&cpc_tty->tty_tx_work, cpc_tty_tx_work, (void *)cpc_tty);
INIT_WORK(&cpc_tty->tty_rx_work, cpc_tty_rx_work, (void *)port);
cpc_tty->buf_rx.first = cpc_tty->buf_rx.last = NULL;
pc300dev->cpc_tty = (void *)cpc_tty;
aux = strlen(pc300dev->dev->name);
memcpy(cpc_tty->name, pc300dev->dev->name, aux);
memcpy(&cpc_tty->name[aux], "-tty", 5);
cpc_open(pc300dev->dev);
cpc_tty_signal_off(pc300dev, CTL_DTR);
CPC_TTY_DBG("%s: Initializing TTY Sync Driver, tty major#%d minor#%i\n",
cpc_tty->name,CPC_TTY_MAJOR,cpc_tty->tty_minor);
return;
}
/*
* PC300 TTY OPEN routine
*
* This routine is called by the tty driver to open the interface
* o verify minor
* o allocate buffer to Rx and Tx
*/
static int cpc_tty_open(struct tty_struct *tty, struct file *flip)
{
int port ;
st_cpc_tty_area *cpc_tty;
if (!tty) {
return -ENODEV;
}
port = tty->index;
if ((port < 0) || (port >= CPC_TTY_NPORTS)){
CPC_TTY_DBG("pc300_tty: open invalid port %d\n", port);
return -ENODEV;
}
cpc_tty = &cpc_tty_area[port];
if (cpc_tty->state == CPC_TTY_ST_IDLE){
CPC_TTY_DBG("%s: open - invalid interface, port=%d\n",
cpc_tty->name, tty->index);
return -ENODEV;
}
if (cpc_tty->num_open == 0) { /* first open of this tty */
if (!cpc_tty_area[port].buf_tx){
cpc_tty_area[port].buf_tx = kmalloc(CPC_TTY_MAX_MTU,GFP_KERNEL);
if (cpc_tty_area[port].buf_tx == 0){
CPC_TTY_DBG("%s: error in memory allocation\n",cpc_tty->name);
return -ENOMEM;
}
}
if (cpc_tty_area[port].buf_rx.first) {
unsigned char * aux;
while (cpc_tty_area[port].buf_rx.first) {
aux = (unsigned char *)cpc_tty_area[port].buf_rx.first;
cpc_tty_area[port].buf_rx.first = cpc_tty_area[port].buf_rx.first->next;
kfree(aux);
}
cpc_tty_area[port].buf_rx.first = NULL;
cpc_tty_area[port].buf_rx.last = NULL;
}
cpc_tty_area[port].state = CPC_TTY_ST_OPEN;
cpc_tty_area[port].tty = tty;
tty->driver_data = &cpc_tty_area[port];
cpc_tty_signal_on(cpc_tty->pc300dev, CTL_DTR);
}
cpc_tty->num_open++;
CPC_TTY_DBG("%s: opening TTY driver\n", cpc_tty->name);
/* avisar driver PC300 */
return 0;
}
/*
* PC300 TTY CLOSE routine
*
* This routine is called by the tty driver to close the interface
* o call close channel in PC300 driver (cpc_closech)
* o free Rx and Tx buffers
*/
static void cpc_tty_close(struct tty_struct *tty, struct file *flip)
{
st_cpc_tty_area *cpc_tty;
unsigned long flags;
int res;
if (!tty || !tty->driver_data ) {
CPC_TTY_DBG("hdlx-tty: no TTY in close \n");
return;
}
cpc_tty = (st_cpc_tty_area *) tty->driver_data;
if ((cpc_tty->tty != tty)|| (cpc_tty->state != CPC_TTY_ST_OPEN)) {
CPC_TTY_DBG("%s: TTY is not opened\n",cpc_tty->name);
return;
}
if (!cpc_tty->num_open) {
CPC_TTY_DBG("%s: TTY is closed\n",cpc_tty->name);
return;
}
if (--cpc_tty->num_open > 0) {
CPC_TTY_DBG("%s: TTY closed\n",cpc_tty->name);
return;
}
cpc_tty_signal_off(cpc_tty->pc300dev, CTL_DTR);
CPC_TTY_LOCK(cpc_tty->pc300dev->chan->card, flags); /* lock irq */
cpc_tty->tty = NULL;
cpc_tty->state = CPC_TTY_ST_INIT;
CPC_TTY_UNLOCK(cpc_tty->pc300dev->chan->card, flags); /* unlock irq */
if (cpc_tty->buf_rx.first) {
unsigned char * aux;
while (cpc_tty->buf_rx.first) {
aux = (unsigned char *)cpc_tty->buf_rx.first;
cpc_tty->buf_rx.first = cpc_tty->buf_rx.first->next;
kfree(aux);
}
cpc_tty->buf_rx.first = NULL;
cpc_tty->buf_rx.last = NULL;
}
kfree(cpc_tty->buf_tx);
cpc_tty->buf_tx = NULL;
CPC_TTY_DBG("%s: TTY closed\n",cpc_tty->name);
if (!serial_drv.refcount && cpc_tty_unreg_flag) {
cpc_tty_unreg_flag = 0;
CPC_TTY_DBG("%s: unregister the tty driver\n", cpc_tty->name);
if ((res=tty_unregister_driver(&serial_drv))) {
CPC_TTY_DBG("%s: ERROR ->unregister the tty driver error=%d\n",
cpc_tty->name,res);
}
}
return;
}
/*
* PC300 TTY WRITE routine
*
* This routine is called by the tty driver to write a series of characters
* to the tty device. The characters may come from user or kernel space.
* o verify the DCD signal
* o send characters to board and start the transmission
*/
static int cpc_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
{
st_cpc_tty_area *cpc_tty;
pc300ch_t *pc300chan;
pc300_t *card;
int ch;
unsigned long flags;
struct net_device_stats *stats;
if (!tty || !tty->driver_data ) {
CPC_TTY_DBG("hdlcX-tty: no TTY in write\n");
return -ENODEV;
}
cpc_tty = (st_cpc_tty_area *) tty->driver_data;
if ((cpc_tty->tty != tty) || (cpc_tty->state != CPC_TTY_ST_OPEN)) {
CPC_TTY_DBG("%s: TTY is not opened\n", cpc_tty->name);
return -ENODEV;
}
if (count > CPC_TTY_MAX_MTU) {
CPC_TTY_DBG("%s: count is invalid\n",cpc_tty->name);
return -EINVAL; /* frame too big */
}
CPC_TTY_DBG("%s: cpc_tty_write data len=%i\n",cpc_tty->name,count);
pc300chan = (pc300ch_t *)((pc300dev_t*)cpc_tty->pc300dev)->chan;
stats = hdlc_stats(((pc300dev_t*)cpc_tty->pc300dev)->dev);
card = (pc300_t *) pc300chan->card;
ch = pc300chan->channel;
/* verify DCD signal*/
if (cpc_readb(card->hw.scabase + M_REG(ST3,ch)) & ST3_DCD) {
/* DCD is OFF */
CPC_TTY_DBG("%s : DCD is OFF\n", cpc_tty->name);
stats->tx_errors++;
stats->tx_carrier_errors++;
CPC_TTY_LOCK(card, flags);
cpc_writeb(card->hw.scabase + M_REG(CMD, ch), CMD_TX_BUF_CLR);
if (card->hw.type == PC300_TE) {
cpc_writeb(card->hw.falcbase + card->hw.cpld_reg2,
cpc_readb(card->hw.falcbase + card->hw.cpld_reg2) &
~(CPLD_REG2_FALC_LED1 << (2 *ch)));
}
CPC_TTY_UNLOCK(card, flags);
return -EINVAL;
}
if (cpc_tty_send_to_card(cpc_tty->pc300dev, (void*)buf, count)) {
/* failed to send */
CPC_TTY_DBG("%s: trasmition error\n", cpc_tty->name);
return 0;
}
return count;
}
/*
* PC300 TTY Write Room routine
*
* This routine returns the numbers of characteres the tty driver will accept
* for queuing to be written.
* o return MTU
*/
static int cpc_tty_write_room(struct tty_struct *tty)
{
st_cpc_tty_area *cpc_tty;
if (!tty || !tty->driver_data ) {
CPC_TTY_DBG("hdlcX-tty: no TTY to write room\n");
return -ENODEV;
}
cpc_tty = (st_cpc_tty_area *) tty->driver_data;
if ((cpc_tty->tty != tty) || (cpc_tty->state != CPC_TTY_ST_OPEN)) {
CPC_TTY_DBG("%s: TTY is not opened\n",cpc_tty->name);
return -ENODEV;
}
CPC_TTY_DBG("%s: write room\n",cpc_tty->name);
return CPC_TTY_MAX_MTU;
}
/*
* PC300 TTY chars in buffer routine
*
* This routine returns the chars number in the transmission buffer
* o returns 0
*/
static int cpc_tty_chars_in_buffer(struct tty_struct *tty)
{
st_cpc_tty_area *cpc_tty;
if (!tty || !tty->driver_data ) {
CPC_TTY_DBG("hdlcX-tty: no TTY to chars in buffer\n");
return -ENODEV;
}
cpc_tty = (st_cpc_tty_area *) tty->driver_data;
if ((cpc_tty->tty != tty) || (cpc_tty->state != CPC_TTY_ST_OPEN)) {
CPC_TTY_DBG("%s: TTY is not opened\n",cpc_tty->name);
return -ENODEV;
}
return(0);
}
static int pc300_tiocmset(struct tty_struct *tty, struct file *file,
unsigned int set, unsigned int clear)
{
st_cpc_tty_area *cpc_tty;
CPC_TTY_DBG("%s: set:%x clear:%x\n", __FUNCTION__, set, clear);
if (!tty || !tty->driver_data ) {
CPC_TTY_DBG("hdlcX-tty: no TTY to chars in buffer\n");
return -ENODEV;
}
cpc_tty = (st_cpc_tty_area *) tty->driver_data;
if (set & TIOCM_RTS)
cpc_tty_signal_on(cpc_tty->pc300dev, CTL_RTS);
if (set & TIOCM_DTR)
cpc_tty_signal_on(cpc_tty->pc300dev, CTL_DTR);
if (clear & TIOCM_RTS)
cpc_tty_signal_off(cpc_tty->pc300dev, CTL_RTS);
if (clear & TIOCM_DTR)
cpc_tty_signal_off(cpc_tty->pc300dev, CTL_DTR);
return 0;
}
static int pc300_tiocmget(struct tty_struct *tty, struct file *file)
{
unsigned int result;
unsigned char status;
unsigned long flags;
st_cpc_tty_area *cpc_tty = (st_cpc_tty_area *) tty->driver_data;
pc300dev_t *pc300dev = cpc_tty->pc300dev;
pc300ch_t *pc300chan = (pc300ch_t *)pc300dev->chan;
pc300_t *card = (pc300_t *) pc300chan->card;
int ch = pc300chan->channel;
cpc_tty = (st_cpc_tty_area *) tty->driver_data;
CPC_TTY_DBG("%s-tty: tiocmget\n",
((struct net_device*)(pc300dev->hdlc))->name);
CPC_TTY_LOCK(card, flags);
status = cpc_readb(card->hw.scabase+M_REG(CTL,ch));
CPC_TTY_UNLOCK(card,flags);
result = ((status & CTL_DTR) ? TIOCM_DTR : 0) |
((status & CTL_RTS) ? TIOCM_RTS : 0);
return result;
}
/*
* PC300 TTY Flush Buffer routine
*
* This routine resets the transmission buffer
*/
static void cpc_tty_flush_buffer(struct tty_struct *tty)
{
st_cpc_tty_area *cpc_tty;
if (!tty || !tty->driver_data ) {
CPC_TTY_DBG("hdlcX-tty: no TTY to flush buffer\n");
return;
}
cpc_tty = (st_cpc_tty_area *) tty->driver_data;
if ((cpc_tty->tty != tty) || (cpc_tty->state != CPC_TTY_ST_OPEN)) {
CPC_TTY_DBG("%s: TTY is not opened\n",cpc_tty->name);
return;
}
CPC_TTY_DBG("%s: call wake_up_interruptible\n",cpc_tty->name);
tty_wakeup(tty);
return;
}
/*
* PC300 TTY Hangup routine
*
* This routine is called by the tty driver to hangup the interface
* o clear DTR signal
*/
static void cpc_tty_hangup(struct tty_struct *tty)
{
st_cpc_tty_area *cpc_tty;
int res;
if (!tty || !tty->driver_data ) {
CPC_TTY_DBG("hdlcX-tty: no TTY to hangup\n");
return ;
}
cpc_tty = (st_cpc_tty_area *) tty->driver_data;
if ((cpc_tty->tty != tty) || (cpc_tty->state != CPC_TTY_ST_OPEN)) {
CPC_TTY_DBG("%s: TTY is not opened\n",cpc_tty->name);
return ;
}
if (!serial_drv.refcount && cpc_tty_unreg_flag) {
cpc_tty_unreg_flag = 0;
CPC_TTY_DBG("%s: unregister the tty driver\n", cpc_tty->name);
if ((res=tty_unregister_driver(&serial_drv))) {
CPC_TTY_DBG("%s: ERROR ->unregister the tty driver error=%d\n",
cpc_tty->name,res);
}
}
cpc_tty_signal_off(cpc_tty->pc300dev, CTL_DTR);
}
/*
* PC300 TTY RX work routine
* This routine treats RX work
* o verify read buffer
* o call the line disc. read
* o free memory
*/
static void cpc_tty_rx_work(void * data)
{
unsigned long port;
int i, j;
st_cpc_tty_area *cpc_tty;
volatile st_cpc_rx_buf *buf;
char flags=0,flg_rx=1;
struct tty_ldisc *ld;
if (cpc_tty_cnt == 0) return;
for (i=0; (i < 4) && flg_rx ; i++) {
flg_rx = 0;
port = (unsigned long)data;
for (j=0; j < CPC_TTY_NPORTS; j++) {
cpc_tty = &cpc_tty_area[port];
if ((buf=cpc_tty->buf_rx.first) != 0) {
if (cpc_tty->tty) {
ld = tty_ldisc_ref(cpc_tty->tty);
if (ld) {
if (ld->receive_buf) {
CPC_TTY_DBG("%s: call line disc. receive_buf\n",cpc_tty->name);
ld->receive_buf(cpc_tty->tty, (char *)(buf->data), &flags, buf->size);
}
tty_ldisc_deref(ld);
}
}
cpc_tty->buf_rx.first = cpc_tty->buf_rx.first->next;
kfree((void *)buf);
buf = cpc_tty->buf_rx.first;
flg_rx = 1;
}
if (++port == CPC_TTY_NPORTS) port = 0;
}
}
}
/*
* PC300 TTY RX work routine
*
* This routine treats RX interrupt.
* o read all frames in card
* o verify the frame size
* o read the frame in rx buffer
*/
static void cpc_tty_rx_disc_frame(pc300ch_t *pc300chan)
{
volatile pcsca_bd_t __iomem * ptdescr;
volatile unsigned char status;
pc300_t *card = (pc300_t *)pc300chan->card;
int ch = pc300chan->channel;
/* dma buf read */
ptdescr = (pcsca_bd_t __iomem *)(card->hw.rambase +
RX_BD_ADDR(ch, pc300chan->rx_first_bd));
while (pc300chan->rx_first_bd != pc300chan->rx_last_bd) {
status = cpc_readb(&ptdescr->status);
cpc_writeb(&ptdescr->status, 0);
cpc_writeb(&ptdescr->len, 0);
pc300chan->rx_first_bd = (pc300chan->rx_first_bd + 1) &
(N_DMA_RX_BUF - 1);
if (status & DST_EOM) {
break; /* end of message */
}
ptdescr = (pcsca_bd_t __iomem *)(card->hw.rambase + cpc_readl(&ptdescr->next));
}
}
void cpc_tty_receive(pc300dev_t *pc300dev)
{
st_cpc_tty_area *cpc_tty;
pc300ch_t *pc300chan = (pc300ch_t *)pc300dev->chan;
pc300_t *card = (pc300_t *)pc300chan->card;
int ch = pc300chan->channel;
volatile pcsca_bd_t __iomem * ptdescr;
struct net_device_stats *stats = hdlc_stats(pc300dev->dev);
int rx_len, rx_aux;
volatile unsigned char status;
unsigned short first_bd = pc300chan->rx_first_bd;
st_cpc_rx_buf *new = NULL;
unsigned char dsr_rx;
if (pc300dev->cpc_tty == NULL) {
return;
}
dsr_rx = cpc_readb(card->hw.scabase + DSR_RX(ch));
cpc_tty = (st_cpc_tty_area *)pc300dev->cpc_tty;
while (1) {
rx_len = 0;
ptdescr = (pcsca_bd_t __iomem *)(card->hw.rambase + RX_BD_ADDR(ch, first_bd));
while ((status = cpc_readb(&ptdescr->status)) & DST_OSB) {
rx_len += cpc_readw(&ptdescr->len);
first_bd = (first_bd + 1) & (N_DMA_RX_BUF - 1);
if (status & DST_EOM) {
break;
}
ptdescr = (pcsca_bd_t __iomem *)(card->hw.rambase+cpc_readl(&ptdescr->next));
}
if (!rx_len) {
if (dsr_rx & DSR_BOF) {
/* update EDA */
cpc_writel(card->hw.scabase + DRX_REG(EDAL, ch),
RX_BD_ADDR(ch, pc300chan->rx_last_bd));
}
kfree(new);
return;
}
if (rx_len > CPC_TTY_MAX_MTU) {
/* Free RX descriptors */
CPC_TTY_DBG("%s: frame size is invalid.\n",cpc_tty->name);
stats->rx_errors++;
stats->rx_frame_errors++;
cpc_tty_rx_disc_frame(pc300chan);
continue;
}
new = (st_cpc_rx_buf *)kmalloc(rx_len + sizeof(st_cpc_rx_buf), GFP_ATOMIC);
if (new == 0) {
cpc_tty_rx_disc_frame(pc300chan);
continue;
}
/* dma buf read */
ptdescr = (pcsca_bd_t __iomem *)(card->hw.rambase +
RX_BD_ADDR(ch, pc300chan->rx_first_bd));
rx_len = 0; /* counter frame size */
while ((status = cpc_readb(&ptdescr->status)) & DST_OSB) {
rx_aux = cpc_readw(&ptdescr->len);
if ((status & (DST_OVR | DST_CRC | DST_RBIT | DST_SHRT | DST_ABT))
|| (rx_aux > BD_DEF_LEN)) {
CPC_TTY_DBG("%s: reception error\n", cpc_tty->name);
stats->rx_errors++;
if (status & DST_OVR) {
stats->rx_fifo_errors++;
}
if (status & DST_CRC) {
stats->rx_crc_errors++;
}
if ((status & (DST_RBIT | DST_SHRT | DST_ABT)) ||
(rx_aux > BD_DEF_LEN)) {
stats->rx_frame_errors++;
}
/* discard remainig descriptors used by the bad frame */
CPC_TTY_DBG("%s: reception error - discard descriptors",
cpc_tty->name);
cpc_tty_rx_disc_frame(pc300chan);
rx_len = 0;
kfree(new);
new = NULL;
break; /* read next frame - while(1) */
}
if (cpc_tty->state != CPC_TTY_ST_OPEN) {
/* Free RX descriptors */
cpc_tty_rx_disc_frame(pc300chan);
stats->rx_dropped++;
rx_len = 0;
kfree(new);
new = NULL;
break; /* read next frame - while(1) */
}
/* read the segment of the frame */
if (rx_aux != 0) {
memcpy_fromio((new->data + rx_len),
(void __iomem *)(card->hw.rambase +
cpc_readl(&ptdescr->ptbuf)), rx_aux);
rx_len += rx_aux;
}
cpc_writeb(&ptdescr->status,0);
cpc_writeb(&ptdescr->len, 0);
pc300chan->rx_first_bd = (pc300chan->rx_first_bd + 1) &
(N_DMA_RX_BUF -1);
if (status & DST_EOM)break;
ptdescr = (pcsca_bd_t __iomem *) (card->hw.rambase +
cpc_readl(&ptdescr->next));
}
/* update pointer */
pc300chan->rx_last_bd = (pc300chan->rx_first_bd - 1) &
(N_DMA_RX_BUF - 1) ;
if (!(dsr_rx & DSR_BOF)) {
/* update EDA */
cpc_writel(card->hw.scabase + DRX_REG(EDAL, ch),
RX_BD_ADDR(ch, pc300chan->rx_last_bd));
}
if (rx_len != 0) {
stats->rx_bytes += rx_len;
if (pc300dev->trace_on) {
cpc_tty_trace(pc300dev, new->data,rx_len, 'R');
}
new->size = rx_len;
new->next = NULL;
if (cpc_tty->buf_rx.first == 0) {
cpc_tty->buf_rx.first = new;
cpc_tty->buf_rx.last = new;
} else {
cpc_tty->buf_rx.last->next = new;
cpc_tty->buf_rx.last = new;
}
schedule_work(&(cpc_tty->tty_rx_work));
stats->rx_packets++;
}
}
}
/*
* PC300 TTY TX work routine
*
* This routine treats TX interrupt.
* o if need call line discipline wakeup
* o call wake_up_interruptible
*/
static void cpc_tty_tx_work(void *data)
{
st_cpc_tty_area *cpc_tty = (st_cpc_tty_area *) data;
struct tty_struct *tty;
CPC_TTY_DBG("%s: cpc_tty_tx_work init\n",cpc_tty->name);
if ((tty = cpc_tty->tty) == 0) {
CPC_TTY_DBG("%s: the interface is not opened\n",cpc_tty->name);
return;
}
tty_wakeup(tty);
}
/*
* PC300 TTY send to card routine
*
* This routine send data to card.
* o clear descriptors
* o write data to DMA buffers
* o start the transmission
*/
static int cpc_tty_send_to_card(pc300dev_t *dev,void* buf, int len)
{
pc300ch_t *chan = (pc300ch_t *)dev->chan;
pc300_t *card = (pc300_t *)chan->card;
int ch = chan->channel;
struct net_device_stats *stats = hdlc_stats(dev->dev);
unsigned long flags;
volatile pcsca_bd_t __iomem *ptdescr;
int i, nchar;
int tosend = len;
int nbuf = ((len - 1)/BD_DEF_LEN) + 1;
unsigned char *pdata=buf;
CPC_TTY_DBG("%s:cpc_tty_send_to_cars len=%i",
(st_cpc_tty_area *)dev->cpc_tty->name,len);
if (nbuf >= card->chan[ch].nfree_tx_bd) {
return 1;
}
/* write buffer to DMA buffers */
CPC_TTY_DBG("%s: call dma_buf_write\n",
(st_cpc_tty_area *)dev->cpc_tty->name);
for (i = 0 ; i < nbuf ; i++) {
ptdescr = (pcsca_bd_t __iomem *)(card->hw.rambase +
TX_BD_ADDR(ch, card->chan[ch].tx_next_bd));
nchar = (BD_DEF_LEN > tosend) ? tosend : BD_DEF_LEN;
if (cpc_readb(&ptdescr->status) & DST_OSB) {
memcpy_toio((void __iomem *)(card->hw.rambase +
cpc_readl(&ptdescr->ptbuf)),
&pdata[len - tosend],
nchar);
card->chan[ch].nfree_tx_bd--;
if ((i + 1) == nbuf) {
/* This must be the last BD to be used */
cpc_writeb(&ptdescr->status, DST_EOM);
} else {
cpc_writeb(&ptdescr->status, 0);
}
cpc_writew(&ptdescr->len, nchar);
} else {
CPC_TTY_DBG("%s: error in dma_buf_write\n",
(st_cpc_tty_area *)dev->cpc_tty->name);
stats->tx_dropped++;
return 1;
}
tosend -= nchar;
card->chan[ch].tx_next_bd =
(card->chan[ch].tx_next_bd + 1) & (N_DMA_TX_BUF - 1);
}
if (dev->trace_on) {
cpc_tty_trace(dev, buf, len,'T');
}
/* start transmission */
CPC_TTY_DBG("%s: start transmission\n",
(st_cpc_tty_area *)dev->cpc_tty->name);
CPC_TTY_LOCK(card, flags);
cpc_writeb(card->hw.scabase + DTX_REG(EDAL, ch),
TX_BD_ADDR(ch, chan->tx_next_bd));
cpc_writeb(card->hw.scabase + M_REG(CMD, ch), CMD_TX_ENA);
cpc_writeb(card->hw.scabase + DSR_TX(ch), DSR_DE);
if (card->hw.type == PC300_TE) {
cpc_writeb(card->hw.falcbase + card->hw.cpld_reg2,
cpc_readb(card->hw.falcbase + card->hw.cpld_reg2) |
(CPLD_REG2_FALC_LED1 << (2 * ch)));
}
CPC_TTY_UNLOCK(card, flags);
return 0;
}
/*
* PC300 TTY trace routine
*
* This routine send trace of connection to application.
* o clear descriptors
* o write data to DMA buffers
* o start the transmission
*/
static void cpc_tty_trace(pc300dev_t *dev, char* buf, int len, char rxtx)
{
struct sk_buff *skb;
if ((skb = dev_alloc_skb(10 + len)) == NULL) {
/* out of memory */
CPC_TTY_DBG("%s: tty_trace - out of memory\n", dev->dev->name);
return;
}
skb_put (skb, 10 + len);
skb->dev = dev->dev;
skb->protocol = htons(ETH_P_CUST);
skb->mac.raw = skb->data;
skb->pkt_type = PACKET_HOST;
skb->len = 10 + len;
memcpy(skb->data,dev->dev->name,5);
skb->data[5] = '[';
skb->data[6] = rxtx;
skb->data[7] = ']';
skb->data[8] = ':';
skb->data[9] = ' ';
memcpy(&skb->data[10], buf, len);
netif_rx(skb);
}
/*
* PC300 TTY unregister service routine
*
* This routine unregister one interface.
*/
void cpc_tty_unregister_service(pc300dev_t *pc300dev)
{
st_cpc_tty_area *cpc_tty;
ulong flags;
int res;
if ((cpc_tty= (st_cpc_tty_area *) pc300dev->cpc_tty) == 0) {
CPC_TTY_DBG("%s: interface is not TTY\n", pc300dev->dev->name);
return;
}
CPC_TTY_DBG("%s: cpc_tty_unregister_service", cpc_tty->name);
if (cpc_tty->pc300dev != pc300dev) {
CPC_TTY_DBG("%s: invalid tty ptr=%s\n",
pc300dev->dev->name, cpc_tty->name);
return;
}
if (--cpc_tty_cnt == 0) {
if (serial_drv.refcount) {
CPC_TTY_DBG("%s: unregister is not possible, refcount=%d",
cpc_tty->name, serial_drv.refcount);
cpc_tty_cnt++;
cpc_tty_unreg_flag = 1;
return;
} else {
CPC_TTY_DBG("%s: unregister the tty driver\n", cpc_tty->name);
if ((res=tty_unregister_driver(&serial_drv))) {
CPC_TTY_DBG("%s: ERROR ->unregister the tty driver error=%d\n",
cpc_tty->name,res);
}
}
}
CPC_TTY_LOCK(pc300dev->chan->card,flags);
cpc_tty->tty = NULL;
CPC_TTY_UNLOCK(pc300dev->chan->card, flags);
cpc_tty->tty_minor = 0;
cpc_tty->state = CPC_TTY_ST_IDLE;
}
/*
* PC300 TTY trigger poll routine
* This routine is called by pc300driver to treats Tx interrupt.
*/
void cpc_tty_trigger_poll(pc300dev_t *pc300dev)
{
st_cpc_tty_area *cpc_tty = (st_cpc_tty_area *)pc300dev->cpc_tty;
if (!cpc_tty) {
return;
}
schedule_work(&(cpc_tty->tty_tx_work));
}
/*
* PC300 TTY reset var routine
* This routine is called by pc300driver to init the TTY area.
*/
void cpc_tty_reset_var(void)
{
int i ;
CPC_TTY_DBG("hdlcX-tty: reset variables\n");
/* reset the tty_driver structure - serial_drv */
memset(&serial_drv, 0, sizeof(struct tty_driver));
for (i=0; i < CPC_TTY_NPORTS; i++){
memset(&cpc_tty_area[i],0, sizeof(st_cpc_tty_area));
}
}
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