/*
* Compatibility mode handshaking is a matter of writing data,
* strobing it, and waiting for the printer to stop being busy.
*/
static long write_compat(unsigned minor, const char *c, unsigned long cnt)
{
long rc;
unsigned short pins = get_pins(minor);
unsigned long remaining = cnt;
while (remaining > 0) {
unsigned char byte;
get_user_ret(byte, c, -EFAULT);
c += 1;
rc = wait_for(BPP_GP_nAck, BPP_GP_Busy, TIME_IDLE_LIMIT, minor);
if (rc == -1) return -ETIMEDOUT;
bpp_outb_p(byte, base_addrs[minor]);
remaining -= 1;
/* snooze(1, minor); */
pins &= ~BPP_PP_nStrobe;
set_pins(pins, minor);
rc = wait_for(BPP_GP_Busy, 0, TIME_PResponse, minor);
pins |= BPP_PP_nStrobe;
set_pins(pins, minor);
}
return cnt - remaining;
}
static int bpp_ioctl(struct inode *inode, struct file *f, unsigned int cmd,
unsigned long arg)
{
int errno = 0;
unsigned minor = MINOR(inode->i_rdev);
if (minor >= BPP_NO) return -ENODEV;
if (!instances[minor].present) return -ENODEV;
switch (cmd) {
case BPP_PUT_PINS:
set_pins(arg, minor);
break;
case BPP_GET_PINS:
errno = get_pins(minor);
break;
case BPP_PUT_DATA:
bpp_outb_p(arg, base_addrs[minor]);
break;
case BPP_GET_DATA:
errno = bpp_inb_p(base_addrs[minor]);
break;
case BPP_SET_INPUT:
if (arg)
if (instances[minor].enhanced) {
unsigned short bits = get_pins(minor);
instances[minor].direction = 0x20;
set_pins(bits, minor);
} else {
errno = -ENOTTY;
}
else {
unsigned short bits = get_pins(minor);
instances[minor].direction = 0x00;
set_pins(bits, minor);
}
break;
default:
errno = -EINVAL;
}
return errno;
}
/*
* Write data using ECP mode. Watch out that the port may be set up
* for reading. If so, turn the port around.
*/
static long write_ecp(unsigned minor, const char __user *c, unsigned long cnt)
{
unsigned short pins = get_pins(minor);
unsigned long remaining = cnt;
if (instances[minor].direction) {
int rc;
/* Event 47 Request bus be turned around */
pins |= BPP_PP_nInit;
set_pins(pins, minor);
/* Wait for Event 49: Peripheral relinquished bus */
rc = wait_for(BPP_GP_PError, 0, TIME_PResponse, minor);
pins |= BPP_PP_nAutoFd;
instances[minor].direction = 0;
set_pins(pins, minor);
}
while (remaining > 0) {
unsigned char byte;
int rc;
if (get_user(byte, c))
return -EFAULT;
rc = wait_for(0, BPP_GP_Busy, TIME_PResponse, minor);
if (rc == -1) return -ETIMEDOUT;
c += 1;
bpp_outb_p(byte, base_addrs[minor]);
pins &= ~BPP_PP_nStrobe;
set_pins(pins, minor);
pins |= BPP_PP_nStrobe;
rc = wait_for(BPP_GP_Busy, 0, TIME_PResponse, minor);
if (rc == -1) return -EIO;
set_pins(pins, minor);
}
return cnt - remaining;
}
/*
* Return ZERO(0) If the negotiation succeeds, an errno otherwise. An
* errno means something broke, and I do not yet know how to fix it.
*/
static int negotiate(unsigned char mode, unsigned minor)
{
int rc;
unsigned short pins = get_pins(minor);
if (pins & BPP_PP_nSelectIn) return -EIO;
/* Event 0: Write the mode to the data lines */
bpp_outb_p(mode, base_addrs[minor]);
snooze(TIME_PSetup, minor);
/* Event 1: Strobe the mode code into the peripheral */
set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe|BPP_PP_nInit, minor);
/* Wait for Event 2: Peripheral responds as a 1284 device. */
rc = wait_for(BPP_GP_PError|BPP_GP_Select|BPP_GP_nFault,
BPP_GP_nAck,
TIME_PResponse,
minor);
if (rc == -1) return -ETIMEDOUT;
/* Event 3: latch extensibility request */
set_pins(BPP_PP_nSelectIn|BPP_PP_nInit, minor);
/* ... quick nap while peripheral ponders the byte i'm sending...*/
snooze(1, minor);
/* Event 4: restore strobe, to ACK peripheral's response. */
set_pins(BPP_PP_nSelectIn|BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, minor);
/* Wait for Event 6: Peripheral latches response bits */
rc = wait_for(BPP_GP_nAck, 0, TIME_PSetup+TIME_PResponse, minor);
if (rc == -1) return -EIO;
/* A 1284 device cannot refuse nibble mode */
if (mode == DEFAULT_NIBBLE) return 0;
if (pins & BPP_GP_Select) return 0;
return -EPROTONOSUPPORT;
}
