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plip.c
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/* $Id: plip.c,v 1.3.6.2 1997/04/16 15:07:56 phil Exp $ */
/* PLIP: A parallel port "network" driver for Linux. */
/* This driver is for parallel port with 5-bit cable (LapLink (R) cable). */
/*
* Authors: Donald Becker <[email protected]>
* Tommy Thorn <[email protected]>
* Tanabe Hiroyasu <[email protected]>
* Alan Cox <[email protected]>
* Peter Bauer <[email protected]>
* Niibe Yutaka <[email protected]>
* Nimrod Zimerman <[email protected]>
*
* Enhancements:
* Modularization and ifreq/ifmap support by Alan Cox.
* Rewritten by Niibe Yutaka.
* parport-sharing awareness code by Philip Blundell.
* SMP locking by Niibe Yutaka.
* Support for parallel ports with no IRQ (poll mode),
* Modifications to use the parallel port API
* by Nimrod Zimerman.
*
* Fixes:
* Niibe Yutaka
* - Module initialization.
* - MTU fix.
* - Make sure other end is OK, before sending a packet.
* - Fix immediate timer problem.
*
* Al Viro
* - Changed {enable,disable}_irq handling to make it work
* with new ("stack") semantics.
*
* 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.
*/
/*
* Original version and the name 'PLIP' from Donald Becker <[email protected]>
* inspired by Russ Nelson's parallel port packet driver.
*
* NOTE:
* Tanabe Hiroyasu had changed the protocol, and it was in Linux v1.0.
* Because of the necessity to communicate to DOS machines with the
* Crynwr packet driver, Peter Bauer changed the protocol again
* back to original protocol.
*
* This version follows original PLIP protocol.
* So, this PLIP can't communicate the PLIP of Linux v1.0.
*/
/*
* To use with DOS box, please do (Turn on ARP switch):
* # ifconfig plip[0-2] arp
*/
static const char version[] = "NET3 PLIP version 2.4-parport [email protected]\n";
/*
Sources:
Ideas and protocols came from Russ Nelson's <[email protected]>
"parallel.asm" parallel port packet driver.
The "Crynwr" parallel port standard specifies the following protocol:
Trigger by sending nibble '0x8' (this causes interrupt on other end)
count-low octet
count-high octet
... data octets
checksum octet
Each octet is sent as <wait for rx. '0x1?'> <send 0x10+(octet&0x0F)>
<wait for rx. '0x0?'> <send 0x00+((octet>>4)&0x0F)>
The packet is encapsulated as if it were ethernet.
The cable used is a de facto standard parallel null cable -- sold as
a "LapLink" cable by various places. You'll need a 12-conductor cable to
make one yourself. The wiring is:
SLCTIN 17 - 17
GROUND 25 - 25
D0->ERROR 2 - 15 15 - 2
D1->SLCT 3 - 13 13 - 3
D2->PAPOUT 4 - 12 12 - 4
D3->ACK 5 - 10 10 - 5
D4->BUSY 6 - 11 11 - 6
Do not connect the other pins. They are
D5,D6,D7 are 7,8,9
STROBE is 1, FEED is 14, INIT is 16
extra grounds are 18,19,20,21,22,23,24
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/string.h>
#include <linux/if_ether.h>
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/lp.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/inetdevice.h>
#include <linux/skbuff.h>
#include <linux/if_plip.h>
#include <linux/workqueue.h>
#include <linux/ioport.h>
#include <linux/spinlock.h>
#include <linux/parport.h>
#include <linux/bitops.h>
#include <net/neighbour.h>
#include <asm/system.h>
#include <asm/irq.h>
#include <asm/byteorder.h>
#include <asm/semaphore.h>
/* Maximum number of devices to support. */
#define PLIP_MAX 8
/* Use 0 for production, 1 for verification, >2 for debug */
#ifndef NET_DEBUG
#define NET_DEBUG 1
#endif
static unsigned int net_debug = NET_DEBUG;
#define ENABLE(irq) if (irq != -1) enable_irq(irq)
#define DISABLE(irq) if (irq != -1) disable_irq(irq)
/* In micro second */
#define PLIP_DELAY_UNIT 1
/* Connection time out = PLIP_TRIGGER_WAIT * PLIP_DELAY_UNIT usec */
#define PLIP_TRIGGER_WAIT 500
/* Nibble time out = PLIP_NIBBLE_WAIT * PLIP_DELAY_UNIT usec */
#define PLIP_NIBBLE_WAIT 3000
/* Bottom halves */
static void plip_kick_bh(struct net_device *dev);
static void plip_bh(struct net_device *dev);
static void plip_timer_bh(struct net_device *dev);
/* Interrupt handler */
static void plip_interrupt(int irq, void *dev_id, struct pt_regs *regs);
/* Functions for DEV methods */
static int plip_tx_packet(struct sk_buff *skb, struct net_device *dev);
static int plip_hard_header(struct sk_buff *skb, struct net_device *dev,
unsigned short type, void *daddr,
void *saddr, unsigned len);
static int plip_hard_header_cache(struct neighbour *neigh,
struct hh_cache *hh);
static int plip_open(struct net_device *dev);
static int plip_close(struct net_device *dev);
static struct net_device_stats *plip_get_stats(struct net_device *dev);
static int plip_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
static int plip_preempt(void *handle);
static void plip_wakeup(void *handle);
enum plip_connection_state {
PLIP_CN_NONE=0,
PLIP_CN_RECEIVE,
PLIP_CN_SEND,
PLIP_CN_CLOSING,
PLIP_CN_ERROR
};
enum plip_packet_state {
PLIP_PK_DONE=0,
PLIP_PK_TRIGGER,
PLIP_PK_LENGTH_LSB,
PLIP_PK_LENGTH_MSB,
PLIP_PK_DATA,
PLIP_PK_CHECKSUM
};
enum plip_nibble_state {
PLIP_NB_BEGIN,
PLIP_NB_1,
PLIP_NB_2,
};
struct plip_local {
enum plip_packet_state state;
enum plip_nibble_state nibble;
union {
struct {
#if defined(__LITTLE_ENDIAN)
unsigned char lsb;
unsigned char msb;
#elif defined(__BIG_ENDIAN)
unsigned char msb;
unsigned char lsb;
#else
#error "Please fix the endianness defines in <asm/byteorder.h>"
#endif
} b;
unsigned short h;
} length;
unsigned short byte;
unsigned char checksum;
unsigned char data;
struct sk_buff *skb;
};
struct net_local {
struct net_device_stats enet_stats;
struct work_struct immediate;
struct work_struct deferred;
struct work_struct timer;
struct plip_local snd_data;
struct plip_local rcv_data;
struct pardevice *pardev;
unsigned long trigger;
unsigned long nibble;
enum plip_connection_state connection;
unsigned short timeout_count;
int is_deferred;
int port_owner;
int should_relinquish;
int (*orig_hard_header)(struct sk_buff *skb, struct net_device *dev,
unsigned short type, void *daddr,
void *saddr, unsigned len);
int (*orig_hard_header_cache)(struct neighbour *neigh,
struct hh_cache *hh);
spinlock_t lock;
atomic_t kill_timer;
struct semaphore killed_timer_sem;
};
static inline void enable_parport_interrupts (struct net_device *dev)
{
if (dev->irq != -1)
{
struct parport *port =
((struct net_local *)dev->priv)->pardev->port;
port->ops->enable_irq (port);
}
}
static inline void disable_parport_interrupts (struct net_device *dev)
{
if (dev->irq != -1)
{
struct parport *port =
((struct net_local *)dev->priv)->pardev->port;
port->ops->disable_irq (port);
}
}
static inline void write_data (struct net_device *dev, unsigned char data)
{
struct parport *port =
((struct net_local *)dev->priv)->pardev->port;
port->ops->write_data (port, data);
}
static inline unsigned char read_status (struct net_device *dev)
{
struct parport *port =
((struct net_local *)dev->priv)->pardev->port;
return port->ops->read_status (port);
}
/* Entry point of PLIP driver.
Probe the hardware, and register/initialize the driver.
PLIP is rather weird, because of the way it interacts with the parport
system. It is _not_ initialised from Space.c. Instead, plip_init()
is called, and that function makes up a "struct net_device" for each port, and
then calls us here.
*/
static void
plip_init_netdev(struct net_device *dev)
{
struct net_local *nl = netdev_priv(dev);
/* Then, override parts of it */
dev->hard_start_xmit = plip_tx_packet;
dev->open = plip_open;
dev->stop = plip_close;
dev->get_stats = plip_get_stats;
dev->do_ioctl = plip_ioctl;
dev->header_cache_update = NULL;
dev->tx_queue_len = 10;
dev->flags = IFF_POINTOPOINT|IFF_NOARP;
memset(dev->dev_addr, 0xfc, ETH_ALEN);
/* Set the private structure */
nl->orig_hard_header = dev->hard_header;
dev->hard_header = plip_hard_header;
nl->orig_hard_header_cache = dev->hard_header_cache;
dev->hard_header_cache = plip_hard_header_cache;
nl->port_owner = 0;
/* Initialize constants */
nl->trigger = PLIP_TRIGGER_WAIT;
nl->nibble = PLIP_NIBBLE_WAIT;
/* Initialize task queue structures */
INIT_WORK(&nl->immediate, (void (*)(void *))plip_bh, dev);
INIT_WORK(&nl->deferred, (void (*)(void *))plip_kick_bh, dev);
if (dev->irq == -1)
INIT_WORK(&nl->timer, (void (*)(void *))plip_timer_bh, dev);
spin_lock_init(&nl->lock);
}
/* Bottom half handler for the delayed request.
This routine is kicked by do_timer().
Request `plip_bh' to be invoked. */
static void
plip_kick_bh(struct net_device *dev)
{
struct net_local *nl = netdev_priv(dev);
if (nl->is_deferred)
schedule_work(&nl->immediate);
}
/* Forward declarations of internal routines */
static int plip_none(struct net_device *, struct net_local *,
struct plip_local *, struct plip_local *);
static int plip_receive_packet(struct net_device *, struct net_local *,
struct plip_local *, struct plip_local *);
static int plip_send_packet(struct net_device *, struct net_local *,
struct plip_local *, struct plip_local *);
static int plip_connection_close(struct net_device *, struct net_local *,
struct plip_local *, struct plip_local *);
static int plip_error(struct net_device *, struct net_local *,
struct plip_local *, struct plip_local *);
static int plip_bh_timeout_error(struct net_device *dev, struct net_local *nl,
struct plip_local *snd,
struct plip_local *rcv,
int error);
#define OK 0
#define TIMEOUT 1
#define ERROR 2
#define HS_TIMEOUT 3
typedef int (*plip_func)(struct net_device *dev, struct net_local *nl,
struct plip_local *snd, struct plip_local *rcv);
static plip_func connection_state_table[] =
{
plip_none,
plip_receive_packet,
plip_send_packet,
plip_connection_close,
plip_error
};
/* Bottom half handler of PLIP. */
static void
plip_bh(struct net_device *dev)
{
struct net_local *nl = netdev_priv(dev);
struct plip_local *snd = &nl->snd_data;
struct plip_local *rcv = &nl->rcv_data;
plip_func f;
int r;
nl->is_deferred = 0;
f = connection_state_table[nl->connection];
if ((r = (*f)(dev, nl, snd, rcv)) != OK
&& (r = plip_bh_timeout_error(dev, nl, snd, rcv, r)) != OK) {
nl->is_deferred = 1;
schedule_delayed_work(&nl->deferred, 1);
}
}
static void
plip_timer_bh(struct net_device *dev)
{
struct net_local *nl = netdev_priv(dev);
if (!(atomic_read (&nl->kill_timer))) {
plip_interrupt (-1, dev, NULL);
schedule_delayed_work(&nl->timer, 1);
}
else {
up (&nl->killed_timer_sem);
}
}
static int
plip_bh_timeout_error(struct net_device *dev, struct net_local *nl,
struct plip_local *snd, struct plip_local *rcv,
int error)
{
unsigned char c0;
/*
* This is tricky. If we got here from the beginning of send (either
* with ERROR or HS_TIMEOUT) we have IRQ enabled. Otherwise it's
* already disabled. With the old variant of {enable,disable}_irq()
* extra disable_irq() was a no-op. Now it became mortal - it's
* unbalanced and thus we'll never re-enable IRQ (until rmmod plip,
* that is). So we have to treat HS_TIMEOUT and ERROR from send
* in a special way.
*/
spin_lock_irq(&nl->lock);
if (nl->connection == PLIP_CN_SEND) {
if (error != ERROR) { /* Timeout */
nl->timeout_count++;
if ((error == HS_TIMEOUT
&& nl->timeout_count <= 10)
|| nl->timeout_count <= 3) {
spin_unlock_irq(&nl->lock);
/* Try again later */
return TIMEOUT;
}
c0 = read_status(dev);
printk(KERN_WARNING "%s: transmit timeout(%d,%02x)\n",
dev->name, snd->state, c0);
} else
error = HS_TIMEOUT;
nl->enet_stats.tx_errors++;
nl->enet_stats.tx_aborted_errors++;
} else if (nl->connection == PLIP_CN_RECEIVE) {
if (rcv->state == PLIP_PK_TRIGGER) {
/* Transmission was interrupted. */
spin_unlock_irq(&nl->lock);
return OK;
}
if (error != ERROR) { /* Timeout */
if (++nl->timeout_count <= 3) {
spin_unlock_irq(&nl->lock);
/* Try again later */
return TIMEOUT;
}
c0 = read_status(dev);
printk(KERN_WARNING "%s: receive timeout(%d,%02x)\n",
dev->name, rcv->state, c0);
}
nl->enet_stats.rx_dropped++;
}
rcv->state = PLIP_PK_DONE;
if (rcv->skb) {
kfree_skb(rcv->skb);
rcv->skb = NULL;
}
snd->state = PLIP_PK_DONE;
if (snd->skb) {
dev_kfree_skb(snd->skb);
snd->skb = NULL;
}
spin_unlock_irq(&nl->lock);
if (error == HS_TIMEOUT) {
DISABLE(dev->irq);
synchronize_irq(dev->irq);
}
disable_parport_interrupts (dev);
netif_stop_queue (dev);
nl->connection = PLIP_CN_ERROR;
write_data (dev, 0x00);
return TIMEOUT;
}
static int
plip_none(struct net_device *dev, struct net_local *nl,
struct plip_local *snd, struct plip_local *rcv)
{
return OK;
}
/* PLIP_RECEIVE --- receive a byte(two nibbles)
Returns OK on success, TIMEOUT on timeout */
static inline int
plip_receive(unsigned short nibble_timeout, struct net_device *dev,
enum plip_nibble_state *ns_p, unsigned char *data_p)
{
unsigned char c0, c1;
unsigned int cx;
switch (*ns_p) {
case PLIP_NB_BEGIN:
cx = nibble_timeout;
while (1) {
c0 = read_status(dev);
udelay(PLIP_DELAY_UNIT);
if ((c0 & 0x80) == 0) {
c1 = read_status(dev);
if (c0 == c1)
break;
}
if (--cx == 0)
return TIMEOUT;
}
*data_p = (c0 >> 3) & 0x0f;
write_data (dev, 0x10); /* send ACK */
*ns_p = PLIP_NB_1;
case PLIP_NB_1:
cx = nibble_timeout;
while (1) {
c0 = read_status(dev);
udelay(PLIP_DELAY_UNIT);
if (c0 & 0x80) {
c1 = read_status(dev);
if (c0 == c1)
break;
}
if (--cx == 0)
return TIMEOUT;
}
*data_p |= (c0 << 1) & 0xf0;
write_data (dev, 0x00); /* send ACK */
*ns_p = PLIP_NB_BEGIN;
case PLIP_NB_2:
break;
}
return OK;
}
/*
* Determine the packet's protocol ID. The rule here is that we
* assume 802.3 if the type field is short enough to be a length.
* This is normal practice and works for any 'now in use' protocol.
*
* PLIP is ethernet ish but the daddr might not be valid if unicast.
* PLIP fortunately has no bus architecture (its Point-to-point).
*
* We can't fix the daddr thing as that quirk (more bug) is embedded
* in far too many old systems not all even running Linux.
*/
static __be16 plip_type_trans(struct sk_buff *skb, struct net_device *dev)
{
struct ethhdr *eth;
unsigned char *rawp;
skb->mac.raw=skb->data;
skb_pull(skb,dev->hard_header_len);
eth = eth_hdr(skb);
if(*eth->h_dest&1)
{
if(memcmp(eth->h_dest,dev->broadcast, ETH_ALEN)==0)
skb->pkt_type=PACKET_BROADCAST;
else
skb->pkt_type=PACKET_MULTICAST;
}
/*
* This ALLMULTI check should be redundant by 1.4
* so don't forget to remove it.
*/
if (ntohs(eth->h_proto) >= 1536)
return eth->h_proto;
rawp = skb->data;
/*
* This is a magic hack to spot IPX packets. Older Novell breaks
* the protocol design and runs IPX over 802.3 without an 802.2 LLC
* layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
* won't work for fault tolerant netware but does for the rest.
*/
if (*(unsigned short *)rawp == 0xFFFF)
return htons(ETH_P_802_3);
/*
* Real 802.2 LLC
*/
return htons(ETH_P_802_2);
}
/* PLIP_RECEIVE_PACKET --- receive a packet */
static int
plip_receive_packet(struct net_device *dev, struct net_local *nl,
struct plip_local *snd, struct plip_local *rcv)
{
unsigned short nibble_timeout = nl->nibble;
unsigned char *lbuf;
switch (rcv->state) {
case PLIP_PK_TRIGGER:
DISABLE(dev->irq);
/* Don't need to synchronize irq, as we can safely ignore it */
disable_parport_interrupts (dev);
write_data (dev, 0x01); /* send ACK */
if (net_debug > 2)
printk(KERN_DEBUG "%s: receive start\n", dev->name);
rcv->state = PLIP_PK_LENGTH_LSB;
rcv->nibble = PLIP_NB_BEGIN;
case PLIP_PK_LENGTH_LSB:
if (snd->state != PLIP_PK_DONE) {
if (plip_receive(nl->trigger, dev,
&rcv->nibble, &rcv->length.b.lsb)) {
/* collision, here dev->tbusy == 1 */
rcv->state = PLIP_PK_DONE;
nl->is_deferred = 1;
nl->connection = PLIP_CN_SEND;
schedule_delayed_work(&nl->deferred, 1);
enable_parport_interrupts (dev);
ENABLE(dev->irq);
return OK;
}
} else {
if (plip_receive(nibble_timeout, dev,
&rcv->nibble, &rcv->length.b.lsb))
return TIMEOUT;
}
rcv->state = PLIP_PK_LENGTH_MSB;
case PLIP_PK_LENGTH_MSB:
if (plip_receive(nibble_timeout, dev,
&rcv->nibble, &rcv->length.b.msb))
return TIMEOUT;
if (rcv->length.h > dev->mtu + dev->hard_header_len
|| rcv->length.h < 8) {
printk(KERN_WARNING "%s: bogus packet size %d.\n", dev->name, rcv->length.h);
return ERROR;
}
/* Malloc up new buffer. */
rcv->skb = dev_alloc_skb(rcv->length.h + 2);
if (rcv->skb == NULL) {
printk(KERN_ERR "%s: Memory squeeze.\n", dev->name);
return ERROR;
}
skb_reserve(rcv->skb, 2); /* Align IP on 16 byte boundaries */
skb_put(rcv->skb,rcv->length.h);
rcv->skb->dev = dev;
rcv->state = PLIP_PK_DATA;
rcv->byte = 0;
rcv->checksum = 0;
case PLIP_PK_DATA:
lbuf = rcv->skb->data;
do
if (plip_receive(nibble_timeout, dev,
&rcv->nibble, &lbuf[rcv->byte]))
return TIMEOUT;
while (++rcv->byte < rcv->length.h);
do
rcv->checksum += lbuf[--rcv->byte];
while (rcv->byte);
rcv->state = PLIP_PK_CHECKSUM;
case PLIP_PK_CHECKSUM:
if (plip_receive(nibble_timeout, dev,
&rcv->nibble, &rcv->data))
return TIMEOUT;
if (rcv->data != rcv->checksum) {
nl->enet_stats.rx_crc_errors++;
if (net_debug)
printk(KERN_DEBUG "%s: checksum error\n", dev->name);
return ERROR;
}
rcv->state = PLIP_PK_DONE;
case PLIP_PK_DONE:
/* Inform the upper layer for the arrival of a packet. */
rcv->skb->protocol=plip_type_trans(rcv->skb, dev);
netif_rx(rcv->skb);
dev->last_rx = jiffies;
nl->enet_stats.rx_bytes += rcv->length.h;
nl->enet_stats.rx_packets++;
rcv->skb = NULL;
if (net_debug > 2)
printk(KERN_DEBUG "%s: receive end\n", dev->name);
/* Close the connection. */
write_data (dev, 0x00);
spin_lock_irq(&nl->lock);
if (snd->state != PLIP_PK_DONE) {
nl->connection = PLIP_CN_SEND;
spin_unlock_irq(&nl->lock);
schedule_work(&nl->immediate);
enable_parport_interrupts (dev);
ENABLE(dev->irq);
return OK;
} else {
nl->connection = PLIP_CN_NONE;
spin_unlock_irq(&nl->lock);
enable_parport_interrupts (dev);
ENABLE(dev->irq);
return OK;
}
}
return OK;
}
/* PLIP_SEND --- send a byte (two nibbles)
Returns OK on success, TIMEOUT when timeout */
static inline int
plip_send(unsigned short nibble_timeout, struct net_device *dev,
enum plip_nibble_state *ns_p, unsigned char data)
{
unsigned char c0;
unsigned int cx;
switch (*ns_p) {
case PLIP_NB_BEGIN:
write_data (dev, data & 0x0f);
*ns_p = PLIP_NB_1;
case PLIP_NB_1:
write_data (dev, 0x10 | (data & 0x0f));
cx = nibble_timeout;
while (1) {
c0 = read_status(dev);
if ((c0 & 0x80) == 0)
break;
if (--cx == 0)
return TIMEOUT;
udelay(PLIP_DELAY_UNIT);
}
write_data (dev, 0x10 | (data >> 4));
*ns_p = PLIP_NB_2;
case PLIP_NB_2:
write_data (dev, (data >> 4));
cx = nibble_timeout;
while (1) {
c0 = read_status(dev);
if (c0 & 0x80)
break;
if (--cx == 0)
return TIMEOUT;
udelay(PLIP_DELAY_UNIT);
}
*ns_p = PLIP_NB_BEGIN;
return OK;
}
return OK;
}
/* PLIP_SEND_PACKET --- send a packet */
static int
plip_send_packet(struct net_device *dev, struct net_local *nl,
struct plip_local *snd, struct plip_local *rcv)
{
unsigned short nibble_timeout = nl->nibble;
unsigned char *lbuf;
unsigned char c0;
unsigned int cx;
if (snd->skb == NULL || (lbuf = snd->skb->data) == NULL) {
printk(KERN_DEBUG "%s: send skb lost\n", dev->name);
snd->state = PLIP_PK_DONE;
snd->skb = NULL;
return ERROR;
}
switch (snd->state) {
case PLIP_PK_TRIGGER:
if ((read_status(dev) & 0xf8) != 0x80)
return HS_TIMEOUT;
/* Trigger remote rx interrupt. */
write_data (dev, 0x08);
cx = nl->trigger;
while (1) {
udelay(PLIP_DELAY_UNIT);
spin_lock_irq(&nl->lock);
if (nl->connection == PLIP_CN_RECEIVE) {
spin_unlock_irq(&nl->lock);
/* Interrupted. */
nl->enet_stats.collisions++;
return OK;
}
c0 = read_status(dev);
if (c0 & 0x08) {
spin_unlock_irq(&nl->lock);
DISABLE(dev->irq);
synchronize_irq(dev->irq);
if (nl->connection == PLIP_CN_RECEIVE) {
/* Interrupted.
We don't need to enable irq,
as it is soon disabled. */
/* Yes, we do. New variant of
{enable,disable}_irq *counts*
them. -- AV */
ENABLE(dev->irq);
nl->enet_stats.collisions++;
return OK;
}
disable_parport_interrupts (dev);
if (net_debug > 2)
printk(KERN_DEBUG "%s: send start\n", dev->name);
snd->state = PLIP_PK_LENGTH_LSB;
snd->nibble = PLIP_NB_BEGIN;
nl->timeout_count = 0;
break;
}
spin_unlock_irq(&nl->lock);
if (--cx == 0) {
write_data (dev, 0x00);
return HS_TIMEOUT;
}
}
case PLIP_PK_LENGTH_LSB:
if (plip_send(nibble_timeout, dev,
&snd->nibble, snd->length.b.lsb))
return TIMEOUT;
snd->state = PLIP_PK_LENGTH_MSB;
case PLIP_PK_LENGTH_MSB:
if (plip_send(nibble_timeout, dev,
&snd->nibble, snd->length.b.msb))
return TIMEOUT;
snd->state = PLIP_PK_DATA;
snd->byte = 0;
snd->checksum = 0;
case PLIP_PK_DATA:
do
if (plip_send(nibble_timeout, dev,
&snd->nibble, lbuf[snd->byte]))
return TIMEOUT;
while (++snd->byte < snd->length.h);
do
snd->checksum += lbuf[--snd->byte];
while (snd->byte);
snd->state = PLIP_PK_CHECKSUM;
case PLIP_PK_CHECKSUM:
if (plip_send(nibble_timeout, dev,
&snd->nibble, snd->checksum))
return TIMEOUT;
nl->enet_stats.tx_bytes += snd->skb->len;
dev_kfree_skb(snd->skb);
nl->enet_stats.tx_packets++;
snd->state = PLIP_PK_DONE;
case PLIP_PK_DONE:
/* Close the connection */
write_data (dev, 0x00);
snd->skb = NULL;
if (net_debug > 2)
printk(KERN_DEBUG "%s: send end\n", dev->name);
nl->connection = PLIP_CN_CLOSING;
nl->is_deferred = 1;
schedule_delayed_work(&nl->deferred, 1);
enable_parport_interrupts (dev);
ENABLE(dev->irq);
return OK;
}
return OK;
}
static int
plip_connection_close(struct net_device *dev, struct net_local *nl,
struct plip_local *snd, struct plip_local *rcv)
{
spin_lock_irq(&nl->lock);
if (nl->connection == PLIP_CN_CLOSING) {
nl->connection = PLIP_CN_NONE;
netif_wake_queue (dev);
}
spin_unlock_irq(&nl->lock);
if (nl->should_relinquish) {
nl->should_relinquish = nl->port_owner = 0;
parport_release(nl->pardev);
}
return OK;
}
/* PLIP_ERROR --- wait till other end settled */
static int
plip_error(struct net_device *dev, struct net_local *nl,
struct plip_local *snd, struct plip_local *rcv)
{
unsigned char status;
status = read_status(dev);
if ((status & 0xf8) == 0x80) {
if (net_debug > 2)
printk(KERN_DEBUG "%s: reset interface.\n", dev->name);
nl->connection = PLIP_CN_NONE;
nl->should_relinquish = 0;
netif_start_queue (dev);
enable_parport_interrupts (dev);
ENABLE(dev->irq);
netif_wake_queue (dev);
} else {
nl->is_deferred = 1;
schedule_delayed_work(&nl->deferred, 1);
}
return OK;
}
/* Handle the parallel port interrupts. */
static void
plip_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
struct net_device *dev = dev_id;
struct net_local *nl;
struct plip_local *rcv;
unsigned char c0;
if (dev == NULL) {
printk(KERN_DEBUG "plip_interrupt: irq %d for unknown device.\n", irq);
return;
}
nl = netdev_priv(dev);
rcv = &nl->rcv_data;
spin_lock_irq (&nl->lock);
c0 = read_status(dev);
if ((c0 & 0xf8) != 0xc0) {
if ((dev->irq != -1) && (net_debug > 1))
printk(KERN_DEBUG "%s: spurious interrupt\n", dev->name);
spin_unlock_irq (&nl->lock);
return;
}
if (net_debug > 3)
printk(KERN_DEBUG "%s: interrupt.\n", dev->name);
switch (nl->connection) {
case PLIP_CN_CLOSING:
netif_wake_queue (dev);
case PLIP_CN_NONE:
case PLIP_CN_SEND:
rcv->state = PLIP_PK_TRIGGER;
nl->connection = PLIP_CN_RECEIVE;
nl->timeout_count = 0;
schedule_work(&nl->immediate);
break;
case PLIP_CN_RECEIVE:
/* May occur because there is race condition
around test and set of dev->interrupt.
Ignore this interrupt. */
break;
case PLIP_CN_ERROR:
printk(KERN_ERR "%s: receive interrupt in error state\n", dev->name);
break;
}
spin_unlock_irq(&nl->lock);
}
static int
plip_tx_packet(struct sk_buff *skb, struct net_device *dev)
{
struct net_local *nl = netdev_priv(dev);
struct plip_local *snd = &nl->snd_data;
if (netif_queue_stopped(dev))
return 1;
/* We may need to grab the bus */
if (!nl->port_owner) {
if (parport_claim(nl->pardev))
return 1;
nl->port_owner = 1;
}
netif_stop_queue (dev);
if (skb->len > dev->mtu + dev->hard_header_len) {
printk(KERN_WARNING "%s: packet too big, %d.\n", dev->name, (int)skb->len);
netif_start_queue (dev);
return 1;
}
if (net_debug > 2)
printk(KERN_DEBUG "%s: send request\n", dev->name);
spin_lock_irq(&nl->lock);
dev->trans_start = jiffies;
snd->skb = skb;
snd->length.h = skb->len;
snd->state = PLIP_PK_TRIGGER;
if (nl->connection == PLIP_CN_NONE) {
nl->connection = PLIP_CN_SEND;
nl->timeout_count = 0;
}
schedule_work(&nl->immediate);
spin_unlock_irq(&nl->lock);
return 0;
}