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ppa.c
1148 lines (998 loc) · 25.7 KB
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ppa.c
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/* ppa.c -- low level driver for the IOMEGA PPA3
* parallel port SCSI host adapter.
*
* (The PPA3 is the embedded controller in the ZIP drive.)
*
* (c) 1995,1996 Grant R. Guenther, grant@torque.net,
* under the terms of the GNU General Public License.
*
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/parport.h>
#include <linux/workqueue.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <asm/io.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
static void ppa_reset_pulse(unsigned int base);
typedef struct {
struct pardevice *dev; /* Parport device entry */
int base; /* Actual port address */
int mode; /* Transfer mode */
struct scsi_cmnd *cur_cmd; /* Current queued command */
struct delayed_work ppa_tq; /* Polling interrupt stuff */
unsigned long jstart; /* Jiffies at start */
unsigned long recon_tmo; /* How many usecs to wait for reconnection (6th bit) */
unsigned int failed:1; /* Failure flag */
unsigned wanted:1; /* Parport sharing busy flag */
wait_queue_head_t *waiting;
struct Scsi_Host *host;
struct list_head list;
} ppa_struct;
#include "ppa.h"
static inline ppa_struct *ppa_dev(struct Scsi_Host *host)
{
return *(ppa_struct **)&host->hostdata;
}
static DEFINE_SPINLOCK(arbitration_lock);
static void got_it(ppa_struct *dev)
{
dev->base = dev->dev->port->base;
if (dev->cur_cmd)
dev->cur_cmd->SCp.phase = 1;
else
wake_up(dev->waiting);
}
static void ppa_wakeup(void *ref)
{
ppa_struct *dev = (ppa_struct *) ref;
unsigned long flags;
spin_lock_irqsave(&arbitration_lock, flags);
if (dev->wanted) {
parport_claim(dev->dev);
got_it(dev);
dev->wanted = 0;
}
spin_unlock_irqrestore(&arbitration_lock, flags);
return;
}
static int ppa_pb_claim(ppa_struct *dev)
{
unsigned long flags;
int res = 1;
spin_lock_irqsave(&arbitration_lock, flags);
if (parport_claim(dev->dev) == 0) {
got_it(dev);
res = 0;
}
dev->wanted = res;
spin_unlock_irqrestore(&arbitration_lock, flags);
return res;
}
static void ppa_pb_dismiss(ppa_struct *dev)
{
unsigned long flags;
int wanted;
spin_lock_irqsave(&arbitration_lock, flags);
wanted = dev->wanted;
dev->wanted = 0;
spin_unlock_irqrestore(&arbitration_lock, flags);
if (!wanted)
parport_release(dev->dev);
}
static inline void ppa_pb_release(ppa_struct *dev)
{
parport_release(dev->dev);
}
/*
* Start of Chipset kludges
*/
/* This is to give the ppa driver a way to modify the timings (and other
* parameters) by writing to the /proc/scsi/ppa/0 file.
* Very simple method really... (To simple, no error checking :( )
* Reason: Kernel hackers HATE having to unload and reload modules for
* testing...
* Also gives a method to use a script to obtain optimum timings (TODO)
*/
static inline int ppa_proc_write(ppa_struct *dev, char *buffer, int length)
{
unsigned long x;
if ((length > 5) && (strncmp(buffer, "mode=", 5) == 0)) {
x = simple_strtoul(buffer + 5, NULL, 0);
dev->mode = x;
return length;
}
if ((length > 10) && (strncmp(buffer, "recon_tmo=", 10) == 0)) {
x = simple_strtoul(buffer + 10, NULL, 0);
dev->recon_tmo = x;
printk(KERN_INFO "ppa: recon_tmo set to %ld\n", x);
return length;
}
printk(KERN_WARNING "ppa /proc: invalid variable\n");
return -EINVAL;
}
static int ppa_proc_info(struct Scsi_Host *host, char *buffer, char **start, off_t offset, int length, int inout)
{
int len = 0;
ppa_struct *dev = ppa_dev(host);
if (inout)
return ppa_proc_write(dev, buffer, length);
len += sprintf(buffer + len, "Version : %s\n", PPA_VERSION);
len +=
sprintf(buffer + len, "Parport : %s\n",
dev->dev->port->name);
len +=
sprintf(buffer + len, "Mode : %s\n",
PPA_MODE_STRING[dev->mode]);
#if PPA_DEBUG > 0
len +=
sprintf(buffer + len, "recon_tmo : %lu\n", dev->recon_tmo);
#endif
/* Request for beyond end of buffer */
if (offset > length)
return 0;
*start = buffer + offset;
len -= offset;
if (len > length)
len = length;
return len;
}
static int device_check(ppa_struct *dev);
#if PPA_DEBUG > 0
#define ppa_fail(x,y) printk("ppa: ppa_fail(%i) from %s at line %d\n",\
y, __func__, __LINE__); ppa_fail_func(x,y);
static inline void ppa_fail_func(ppa_struct *dev, int error_code)
#else
static inline void ppa_fail(ppa_struct *dev, int error_code)
#endif
{
/* If we fail a device then we trash status / message bytes */
if (dev->cur_cmd) {
dev->cur_cmd->result = error_code << 16;
dev->failed = 1;
}
}
/*
* Wait for the high bit to be set.
*
* In principle, this could be tied to an interrupt, but the adapter
* doesn't appear to be designed to support interrupts. We spin on
* the 0x80 ready bit.
*/
static unsigned char ppa_wait(ppa_struct *dev)
{
int k;
unsigned short ppb = dev->base;
unsigned char r;
k = PPA_SPIN_TMO;
/* Wait for bit 6 and 7 - PJC */
for (r = r_str(ppb); ((r & 0xc0) != 0xc0) && (k); k--) {
udelay(1);
r = r_str(ppb);
}
/*
* return some status information.
* Semantics: 0xc0 = ZIP wants more data
* 0xd0 = ZIP wants to send more data
* 0xe0 = ZIP is expecting SCSI command data
* 0xf0 = end of transfer, ZIP is sending status
*/
if (k)
return (r & 0xf0);
/* Counter expired - Time out occurred */
ppa_fail(dev, DID_TIME_OUT);
printk(KERN_WARNING "ppa timeout in ppa_wait\n");
return 0; /* command timed out */
}
/*
* Clear EPP Timeout Bit
*/
static inline void epp_reset(unsigned short ppb)
{
int i;
i = r_str(ppb);
w_str(ppb, i);
w_str(ppb, i & 0xfe);
}
/*
* Wait for empty ECP fifo (if we are in ECP fifo mode only)
*/
static inline void ecp_sync(ppa_struct *dev)
{
int i, ppb_hi = dev->dev->port->base_hi;
if (ppb_hi == 0)
return;
if ((r_ecr(ppb_hi) & 0xe0) == 0x60) { /* mode 011 == ECP fifo mode */
for (i = 0; i < 100; i++) {
if (r_ecr(ppb_hi) & 0x01)
return;
udelay(5);
}
printk(KERN_WARNING "ppa: ECP sync failed as data still present in FIFO.\n");
}
}
static int ppa_byte_out(unsigned short base, const char *buffer, int len)
{
int i;
for (i = len; i; i--) {
w_dtr(base, *buffer++);
w_ctr(base, 0xe);
w_ctr(base, 0xc);
}
return 1; /* All went well - we hope! */
}
static int ppa_byte_in(unsigned short base, char *buffer, int len)
{
int i;
for (i = len; i; i--) {
*buffer++ = r_dtr(base);
w_ctr(base, 0x27);
w_ctr(base, 0x25);
}
return 1; /* All went well - we hope! */
}
static int ppa_nibble_in(unsigned short base, char *buffer, int len)
{
for (; len; len--) {
unsigned char h;
w_ctr(base, 0x4);
h = r_str(base) & 0xf0;
w_ctr(base, 0x6);
*buffer++ = h | ((r_str(base) & 0xf0) >> 4);
}
return 1; /* All went well - we hope! */
}
static int ppa_out(ppa_struct *dev, char *buffer, int len)
{
int r;
unsigned short ppb = dev->base;
r = ppa_wait(dev);
if ((r & 0x50) != 0x40) {
ppa_fail(dev, DID_ERROR);
return 0;
}
switch (dev->mode) {
case PPA_NIBBLE:
case PPA_PS2:
/* 8 bit output, with a loop */
r = ppa_byte_out(ppb, buffer, len);
break;
case PPA_EPP_32:
case PPA_EPP_16:
case PPA_EPP_8:
epp_reset(ppb);
w_ctr(ppb, 0x4);
#ifdef CONFIG_SCSI_IZIP_EPP16
if (!(((long) buffer | len) & 0x01))
outsw(ppb + 4, buffer, len >> 1);
#else
if (!(((long) buffer | len) & 0x03))
outsl(ppb + 4, buffer, len >> 2);
#endif
else
outsb(ppb + 4, buffer, len);
w_ctr(ppb, 0xc);
r = !(r_str(ppb) & 0x01);
w_ctr(ppb, 0xc);
ecp_sync(dev);
break;
default:
printk(KERN_ERR "PPA: bug in ppa_out()\n");
r = 0;
}
return r;
}
static int ppa_in(ppa_struct *dev, char *buffer, int len)
{
int r;
unsigned short ppb = dev->base;
r = ppa_wait(dev);
if ((r & 0x50) != 0x50) {
ppa_fail(dev, DID_ERROR);
return 0;
}
switch (dev->mode) {
case PPA_NIBBLE:
/* 4 bit input, with a loop */
r = ppa_nibble_in(ppb, buffer, len);
w_ctr(ppb, 0xc);
break;
case PPA_PS2:
/* 8 bit input, with a loop */
w_ctr(ppb, 0x25);
r = ppa_byte_in(ppb, buffer, len);
w_ctr(ppb, 0x4);
w_ctr(ppb, 0xc);
break;
case PPA_EPP_32:
case PPA_EPP_16:
case PPA_EPP_8:
epp_reset(ppb);
w_ctr(ppb, 0x24);
#ifdef CONFIG_SCSI_IZIP_EPP16
if (!(((long) buffer | len) & 0x01))
insw(ppb + 4, buffer, len >> 1);
#else
if (!(((long) buffer | len) & 0x03))
insl(ppb + 4, buffer, len >> 2);
#endif
else
insb(ppb + 4, buffer, len);
w_ctr(ppb, 0x2c);
r = !(r_str(ppb) & 0x01);
w_ctr(ppb, 0x2c);
ecp_sync(dev);
break;
default:
printk(KERN_ERR "PPA: bug in ppa_ins()\n");
r = 0;
break;
}
return r;
}
/* end of ppa_io.h */
static inline void ppa_d_pulse(unsigned short ppb, unsigned char b)
{
w_dtr(ppb, b);
w_ctr(ppb, 0xc);
w_ctr(ppb, 0xe);
w_ctr(ppb, 0xc);
w_ctr(ppb, 0x4);
w_ctr(ppb, 0xc);
}
static void ppa_disconnect(ppa_struct *dev)
{
unsigned short ppb = dev->base;
ppa_d_pulse(ppb, 0);
ppa_d_pulse(ppb, 0x3c);
ppa_d_pulse(ppb, 0x20);
ppa_d_pulse(ppb, 0xf);
}
static inline void ppa_c_pulse(unsigned short ppb, unsigned char b)
{
w_dtr(ppb, b);
w_ctr(ppb, 0x4);
w_ctr(ppb, 0x6);
w_ctr(ppb, 0x4);
w_ctr(ppb, 0xc);
}
static inline void ppa_connect(ppa_struct *dev, int flag)
{
unsigned short ppb = dev->base;
ppa_c_pulse(ppb, 0);
ppa_c_pulse(ppb, 0x3c);
ppa_c_pulse(ppb, 0x20);
if ((flag == CONNECT_EPP_MAYBE) && IN_EPP_MODE(dev->mode))
ppa_c_pulse(ppb, 0xcf);
else
ppa_c_pulse(ppb, 0x8f);
}
static int ppa_select(ppa_struct *dev, int target)
{
int k;
unsigned short ppb = dev->base;
/*
* Bit 6 (0x40) is the device selected bit.
* First we must wait till the current device goes off line...
*/
k = PPA_SELECT_TMO;
do {
k--;
udelay(1);
} while ((r_str(ppb) & 0x40) && (k));
if (!k)
return 0;
w_dtr(ppb, (1 << target));
w_ctr(ppb, 0xe);
w_ctr(ppb, 0xc);
w_dtr(ppb, 0x80); /* This is NOT the initator */
w_ctr(ppb, 0x8);
k = PPA_SELECT_TMO;
do {
k--;
udelay(1);
}
while (!(r_str(ppb) & 0x40) && (k));
if (!k)
return 0;
return 1;
}
/*
* This is based on a trace of what the Iomega DOS 'guest' driver does.
* I've tried several different kinds of parallel ports with guest and
* coded this to react in the same ways that it does.
*
* The return value from this function is just a hint about where the
* handshaking failed.
*
*/
static int ppa_init(ppa_struct *dev)
{
int retv;
unsigned short ppb = dev->base;
ppa_disconnect(dev);
ppa_connect(dev, CONNECT_NORMAL);
retv = 2; /* Failed */
w_ctr(ppb, 0xe);
if ((r_str(ppb) & 0x08) == 0x08)
retv--;
w_ctr(ppb, 0xc);
if ((r_str(ppb) & 0x08) == 0x00)
retv--;
if (!retv)
ppa_reset_pulse(ppb);
udelay(1000); /* Allow devices to settle down */
ppa_disconnect(dev);
udelay(1000); /* Another delay to allow devices to settle */
if (retv)
return -EIO;
return device_check(dev);
}
static inline int ppa_send_command(struct scsi_cmnd *cmd)
{
ppa_struct *dev = ppa_dev(cmd->device->host);
int k;
w_ctr(dev->base, 0x0c);
for (k = 0; k < cmd->cmd_len; k++)
if (!ppa_out(dev, &cmd->cmnd[k], 1))
return 0;
return 1;
}
/*
* The bulk flag enables some optimisations in the data transfer loops,
* it should be true for any command that transfers data in integral
* numbers of sectors.
*
* The driver appears to remain stable if we speed up the parallel port
* i/o in this function, but not elsewhere.
*/
static int ppa_completion(struct scsi_cmnd *cmd)
{
/* Return codes:
* -1 Error
* 0 Told to schedule
* 1 Finished data transfer
*/
ppa_struct *dev = ppa_dev(cmd->device->host);
unsigned short ppb = dev->base;
unsigned long start_jiffies = jiffies;
unsigned char r, v;
int fast, bulk, status;
v = cmd->cmnd[0];
bulk = ((v == READ_6) ||
(v == READ_10) || (v == WRITE_6) || (v == WRITE_10));
/*
* We only get here if the drive is ready to comunicate,
* hence no need for a full ppa_wait.
*/
r = (r_str(ppb) & 0xf0);
while (r != (unsigned char) 0xf0) {
/*
* If we have been running for more than a full timer tick
* then take a rest.
*/
if (time_after(jiffies, start_jiffies + 1))
return 0;
if ((cmd->SCp.this_residual <= 0)) {
ppa_fail(dev, DID_ERROR);
return -1; /* ERROR_RETURN */
}
/* On some hardware we have SCSI disconnected (6th bit low)
* for about 100usecs. It is too expensive to wait a
* tick on every loop so we busy wait for no more than
* 500usecs to give the drive a chance first. We do not
* change things for "normal" hardware since generally
* the 6th bit is always high.
* This makes the CPU load higher on some hardware
* but otherwise we can not get more than 50K/secs
* on this problem hardware.
*/
if ((r & 0xc0) != 0xc0) {
/* Wait for reconnection should be no more than
* jiffy/2 = 5ms = 5000 loops
*/
unsigned long k = dev->recon_tmo;
for (; k && ((r = (r_str(ppb) & 0xf0)) & 0xc0) != 0xc0;
k--)
udelay(1);
if (!k)
return 0;
}
/* determine if we should use burst I/O */
fast = (bulk && (cmd->SCp.this_residual >= PPA_BURST_SIZE))
? PPA_BURST_SIZE : 1;
if (r == (unsigned char) 0xc0)
status = ppa_out(dev, cmd->SCp.ptr, fast);
else
status = ppa_in(dev, cmd->SCp.ptr, fast);
cmd->SCp.ptr += fast;
cmd->SCp.this_residual -= fast;
if (!status) {
ppa_fail(dev, DID_BUS_BUSY);
return -1; /* ERROR_RETURN */
}
if (cmd->SCp.buffer && !cmd->SCp.this_residual) {
/* if scatter/gather, advance to the next segment */
if (cmd->SCp.buffers_residual--) {
cmd->SCp.buffer++;
cmd->SCp.this_residual =
cmd->SCp.buffer->length;
cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
}
}
/* Now check to see if the drive is ready to comunicate */
r = (r_str(ppb) & 0xf0);
/* If not, drop back down to the scheduler and wait a timer tick */
if (!(r & 0x80))
return 0;
}
return 1; /* FINISH_RETURN */
}
/*
* Since the PPA itself doesn't generate interrupts, we use
* the scheduler's task queue to generate a stream of call-backs and
* complete the request when the drive is ready.
*/
static void ppa_interrupt(struct work_struct *work)
{
ppa_struct *dev = container_of(work, ppa_struct, ppa_tq.work);
struct scsi_cmnd *cmd = dev->cur_cmd;
if (!cmd) {
printk(KERN_ERR "PPA: bug in ppa_interrupt\n");
return;
}
if (ppa_engine(dev, cmd)) {
schedule_delayed_work(&dev->ppa_tq, 1);
return;
}
/* Command must of completed hence it is safe to let go... */
#if PPA_DEBUG > 0
switch ((cmd->result >> 16) & 0xff) {
case DID_OK:
break;
case DID_NO_CONNECT:
printk(KERN_DEBUG "ppa: no device at SCSI ID %i\n", cmd->device->target);
break;
case DID_BUS_BUSY:
printk(KERN_DEBUG "ppa: BUS BUSY - EPP timeout detected\n");
break;
case DID_TIME_OUT:
printk(KERN_DEBUG "ppa: unknown timeout\n");
break;
case DID_ABORT:
printk(KERN_DEBUG "ppa: told to abort\n");
break;
case DID_PARITY:
printk(KERN_DEBUG "ppa: parity error (???)\n");
break;
case DID_ERROR:
printk(KERN_DEBUG "ppa: internal driver error\n");
break;
case DID_RESET:
printk(KERN_DEBUG "ppa: told to reset device\n");
break;
case DID_BAD_INTR:
printk(KERN_WARNING "ppa: bad interrupt (???)\n");
break;
default:
printk(KERN_WARNING "ppa: bad return code (%02x)\n",
(cmd->result >> 16) & 0xff);
}
#endif
if (cmd->SCp.phase > 1)
ppa_disconnect(dev);
ppa_pb_dismiss(dev);
dev->cur_cmd = NULL;
cmd->scsi_done(cmd);
}
static int ppa_engine(ppa_struct *dev, struct scsi_cmnd *cmd)
{
unsigned short ppb = dev->base;
unsigned char l = 0, h = 0;
int retv;
/* First check for any errors that may of occurred
* Here we check for internal errors
*/
if (dev->failed)
return 0;
switch (cmd->SCp.phase) {
case 0: /* Phase 0 - Waiting for parport */
if (time_after(jiffies, dev->jstart + HZ)) {
/*
* We waited more than a second
* for parport to call us
*/
ppa_fail(dev, DID_BUS_BUSY);
return 0;
}
return 1; /* wait until ppa_wakeup claims parport */
case 1: /* Phase 1 - Connected */
{ /* Perform a sanity check for cable unplugged */
int retv = 2; /* Failed */
ppa_connect(dev, CONNECT_EPP_MAYBE);
w_ctr(ppb, 0xe);
if ((r_str(ppb) & 0x08) == 0x08)
retv--;
w_ctr(ppb, 0xc);
if ((r_str(ppb) & 0x08) == 0x00)
retv--;
if (retv) {
if (time_after(jiffies, dev->jstart + (1 * HZ))) {
printk(KERN_ERR "ppa: Parallel port cable is unplugged.\n");
ppa_fail(dev, DID_BUS_BUSY);
return 0;
} else {
ppa_disconnect(dev);
return 1; /* Try again in a jiffy */
}
}
cmd->SCp.phase++;
}
case 2: /* Phase 2 - We are now talking to the scsi bus */
if (!ppa_select(dev, scmd_id(cmd))) {
ppa_fail(dev, DID_NO_CONNECT);
return 0;
}
cmd->SCp.phase++;
case 3: /* Phase 3 - Ready to accept a command */
w_ctr(ppb, 0x0c);
if (!(r_str(ppb) & 0x80))
return 1;
if (!ppa_send_command(cmd))
return 0;
cmd->SCp.phase++;
case 4: /* Phase 4 - Setup scatter/gather buffers */
if (scsi_bufflen(cmd)) {
cmd->SCp.buffer = scsi_sglist(cmd);
cmd->SCp.this_residual = cmd->SCp.buffer->length;
cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
} else {
cmd->SCp.buffer = NULL;
cmd->SCp.this_residual = 0;
cmd->SCp.ptr = NULL;
}
cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
cmd->SCp.phase++;
case 5: /* Phase 5 - Data transfer stage */
w_ctr(ppb, 0x0c);
if (!(r_str(ppb) & 0x80))
return 1;
retv = ppa_completion(cmd);
if (retv == -1)
return 0;
if (retv == 0)
return 1;
cmd->SCp.phase++;
case 6: /* Phase 6 - Read status/message */
cmd->result = DID_OK << 16;
/* Check for data overrun */
if (ppa_wait(dev) != (unsigned char) 0xf0) {
ppa_fail(dev, DID_ERROR);
return 0;
}
if (ppa_in(dev, &l, 1)) { /* read status byte */
/* Check for optional message byte */
if (ppa_wait(dev) == (unsigned char) 0xf0)
ppa_in(dev, &h, 1);
cmd->result =
(DID_OK << 16) + (h << 8) + (l & STATUS_MASK);
}
return 0; /* Finished */
break;
default:
printk(KERN_ERR "ppa: Invalid scsi phase\n");
}
return 0;
}
static int ppa_queuecommand_lck(struct scsi_cmnd *cmd,
void (*done) (struct scsi_cmnd *))
{
ppa_struct *dev = ppa_dev(cmd->device->host);
if (dev->cur_cmd) {
printk(KERN_ERR "PPA: bug in ppa_queuecommand\n");
return 0;
}
dev->failed = 0;
dev->jstart = jiffies;
dev->cur_cmd = cmd;
cmd->scsi_done = done;
cmd->result = DID_ERROR << 16; /* default return code */
cmd->SCp.phase = 0; /* bus free */
schedule_delayed_work(&dev->ppa_tq, 0);
ppa_pb_claim(dev);
return 0;
}
static DEF_SCSI_QCMD(ppa_queuecommand)
/*
* Apparently the disk->capacity attribute is off by 1 sector
* for all disk drives. We add the one here, but it should really
* be done in sd.c. Even if it gets fixed there, this will still
* work.
*/
static int ppa_biosparam(struct scsi_device *sdev, struct block_device *dev,
sector_t capacity, int ip[])
{
ip[0] = 0x40;
ip[1] = 0x20;
ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
if (ip[2] > 1024) {
ip[0] = 0xff;
ip[1] = 0x3f;
ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
if (ip[2] > 1023)
ip[2] = 1023;
}
return 0;
}
static int ppa_abort(struct scsi_cmnd *cmd)
{
ppa_struct *dev = ppa_dev(cmd->device->host);
/*
* There is no method for aborting commands since Iomega
* have tied the SCSI_MESSAGE line high in the interface
*/
switch (cmd->SCp.phase) {
case 0: /* Do not have access to parport */
case 1: /* Have not connected to interface */
dev->cur_cmd = NULL; /* Forget the problem */
return SUCCESS;
break;
default: /* SCSI command sent, can not abort */
return FAILED;
break;
}
}
static void ppa_reset_pulse(unsigned int base)
{
w_dtr(base, 0x40);
w_ctr(base, 0x8);
udelay(30);
w_ctr(base, 0xc);
}
static int ppa_reset(struct scsi_cmnd *cmd)
{
ppa_struct *dev = ppa_dev(cmd->device->host);
if (cmd->SCp.phase)
ppa_disconnect(dev);
dev->cur_cmd = NULL; /* Forget the problem */
ppa_connect(dev, CONNECT_NORMAL);
ppa_reset_pulse(dev->base);
mdelay(1); /* device settle delay */
ppa_disconnect(dev);
mdelay(1); /* device settle delay */
return SUCCESS;
}
static int device_check(ppa_struct *dev)
{
/* This routine looks for a device and then attempts to use EPP
to send a command. If all goes as planned then EPP is available. */
static u8 cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
int loop, old_mode, status, k, ppb = dev->base;
unsigned char l;
old_mode = dev->mode;
for (loop = 0; loop < 8; loop++) {
/* Attempt to use EPP for Test Unit Ready */
if ((ppb & 0x0007) == 0x0000)
dev->mode = PPA_EPP_32;
second_pass:
ppa_connect(dev, CONNECT_EPP_MAYBE);
/* Select SCSI device */
if (!ppa_select(dev, loop)) {
ppa_disconnect(dev);
continue;
}
printk(KERN_INFO "ppa: Found device at ID %i, Attempting to use %s\n",
loop, PPA_MODE_STRING[dev->mode]);
/* Send SCSI command */
status = 1;
w_ctr(ppb, 0x0c);
for (l = 0; (l < 6) && (status); l++)
status = ppa_out(dev, cmd, 1);
if (!status) {
ppa_disconnect(dev);
ppa_connect(dev, CONNECT_EPP_MAYBE);
w_dtr(ppb, 0x40);
w_ctr(ppb, 0x08);
udelay(30);
w_ctr(ppb, 0x0c);
udelay(1000);
ppa_disconnect(dev);
udelay(1000);
if (dev->mode == PPA_EPP_32) {
dev->mode = old_mode;
goto second_pass;
}
return -EIO;
}
w_ctr(ppb, 0x0c);
k = 1000000; /* 1 Second */
do {
l = r_str(ppb);
k--;
udelay(1);
} while (!(l & 0x80) && (k));
l &= 0xf0;
if (l != 0xf0) {
ppa_disconnect(dev);
ppa_connect(dev, CONNECT_EPP_MAYBE);
ppa_reset_pulse(ppb);
udelay(1000);
ppa_disconnect(dev);
udelay(1000);
if (dev->mode == PPA_EPP_32) {
dev->mode = old_mode;
goto second_pass;
}
return -EIO;
}
ppa_disconnect(dev);
printk(KERN_INFO "ppa: Communication established with ID %i using %s\n",
loop, PPA_MODE_STRING[dev->mode]);
ppa_connect(dev, CONNECT_EPP_MAYBE);
ppa_reset_pulse(ppb);
udelay(1000);
ppa_disconnect(dev);
udelay(1000);
return 0;
}
return -ENODEV;
}
static int ppa_adjust_queue(struct scsi_device *device)
{
blk_queue_bounce_limit(device->request_queue, BLK_BOUNCE_HIGH);
return 0;
}
static struct scsi_host_template ppa_template = {
.module = THIS_MODULE,
.proc_name = "ppa",
.proc_info = ppa_proc_info,
.name = "Iomega VPI0 (ppa) interface",
.queuecommand = ppa_queuecommand,
.eh_abort_handler = ppa_abort,
.eh_bus_reset_handler = ppa_reset,
.eh_host_reset_handler = ppa_reset,
.bios_param = ppa_biosparam,
.this_id = -1,
.sg_tablesize = SG_ALL,
.cmd_per_lun = 1,
.use_clustering = ENABLE_CLUSTERING,
.can_queue = 1,
.slave_alloc = ppa_adjust_queue,
};
/***************************************************************************
* Parallel port probing routines *