kevin/linux
1
Fork 0
Code
7d12e780e0
linux/drivers/parport/ieee1284.c
David Howells 7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers 
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00

818 lines
23 KiB
C
Raw Blame History

/* $Id: parport_ieee1284.c,v 1.4 1997/10/19 21:37:21 philip Exp $
* IEEE-1284 implementation for parport.
*
* Authors: Phil Blundell <philb@gnu.org>
* Carsten Gross <carsten@sol.wohnheim.uni-ulm.de>
* Jose Renau <renau@acm.org>
* Tim Waugh <tim@cyberelk.demon.co.uk> (largely rewritten)
*
* This file is responsible for IEEE 1284 negotiation, and for handing
* read/write requests to low-level drivers.
*
* Any part of this program may be used in documents licensed under
* the GNU Free Documentation License, Version 1.1 or any later version
* published by the Free Software Foundation.
*
* Various hacks, Fred Barnes <frmb2@ukc.ac.uk>, 04/2000
*/
#include <linux/module.h>
#include <linux/threads.h>
#include <linux/parport.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/timer.h>
#include <linux/sched.h>
#undef DEBUG /* undef me for production */
#ifdef CONFIG_LP_CONSOLE
#undef DEBUG /* Don't want a garbled console */
#endif
#ifdef DEBUG
#define DPRINTK(stuff...) printk (stuff)
#else
#define DPRINTK(stuff...)
#endif
/* Make parport_wait_peripheral wake up.
* It will be useful to call this from an interrupt handler. */
static void parport_ieee1284_wakeup (struct parport *port)
{
up (&port->physport->ieee1284.irq);
}
static struct parport *port_from_cookie[PARPORT_MAX];
static void timeout_waiting_on_port (unsigned long cookie)
{
parport_ieee1284_wakeup (port_from_cookie[cookie % PARPORT_MAX]);
}
/**
* parport_wait_event - wait for an event on a parallel port
* @port: port to wait on
* @timeout: time to wait (in jiffies)
*
* This function waits for up to @timeout jiffies for an
* interrupt to occur on a parallel port. If the port timeout is
* set to zero, it returns immediately.
*
* If an interrupt occurs before the timeout period elapses, this
* function returns zero immediately. If it times out, it returns
* one. An error code less than zero indicates an error (most
* likely a pending signal), and the calling code should finish
* what it's doing as soon as it can.
*/
int parport_wait_event (struct parport *port, signed long timeout)
{
int ret;
struct timer_list timer;
if (!port->physport->cad->timeout)
/* Zero timeout is special, and we can't down() the
semaphore. */
return 1;
init_timer (&timer);
timer.expires = jiffies + timeout;
timer.function = timeout_waiting_on_port;
port_from_cookie[port->number % PARPORT_MAX] = port;
timer.data = port->number;
add_timer (&timer);
ret = down_interruptible (&port->physport->ieee1284.irq);
if (!del_timer (&timer) && !ret)
/* Timed out. */
ret = 1;
return ret;
}
/**
* parport_poll_peripheral - poll status lines
* @port: port to watch
* @mask: status lines to watch
* @result: desired values of chosen status lines
* @usec: timeout
*
* This function busy-waits until the masked status lines have
* the desired values, or until the timeout period elapses. The
* @mask and @result parameters are bitmasks, with the bits
* defined by the constants in parport.h: %PARPORT_STATUS_BUSY,
* and so on.
*
* This function does not call schedule(); instead it busy-waits
* using udelay(). It currently has a resolution of 5usec.
*
* If the status lines take on the desired values before the
* timeout period elapses, parport_poll_peripheral() returns zero
* immediately. A return value greater than zero indicates
* a timeout. An error code (less than zero) indicates an error,
* most likely a signal that arrived, and the caller should
* finish what it is doing as soon as possible.
*/
int parport_poll_peripheral(struct parport *port,
unsigned char mask,
unsigned char result,
int usec)
{
/* Zero return code is success, >0 is timeout. */
int count = usec / 5 + 2;
int i;
unsigned char status;
for (i = 0; i < count; i++) {
status = parport_read_status (port);
if ((status & mask) == result)
return 0;
if (signal_pending (current))
return -EINTR;
if (need_resched())
break;
if (i >= 2)
udelay (5);
}
return 1;
}
/**
* parport_wait_peripheral - wait for status lines to change in 35ms
* @port: port to watch
* @mask: status lines to watch
* @result: desired values of chosen status lines
*
* This function waits until the masked status lines have the
* desired values, or until 35ms have elapsed (see IEEE 1284-1994
* page 24 to 25 for why this value in particular is hardcoded).
* The @mask and @result parameters are bitmasks, with the bits
* defined by the constants in parport.h: %PARPORT_STATUS_BUSY,
* and so on.
*
* The port is polled quickly to start off with, in anticipation
* of a fast response from the peripheral. This fast polling
* time is configurable (using /proc), and defaults to 500usec.
* If the timeout for this port (see parport_set_timeout()) is
* zero, the fast polling time is 35ms, and this function does
* not call schedule().
*
* If the timeout for this port is non-zero, after the fast
* polling fails it uses parport_wait_event() to wait for up to
* 10ms, waking up if an interrupt occurs.
*/
int parport_wait_peripheral(struct parport *port,
unsigned char mask,
unsigned char result)
{
int ret;
int usec;
unsigned long deadline;
unsigned char status;
usec = port->physport->spintime; /* usecs of fast polling */
if (!port->physport->cad->timeout)
/* A zero timeout is "special": busy wait for the
entire 35ms. */
usec = 35000;
/* Fast polling.
*
* This should be adjustable.
* How about making a note (in the device structure) of how long
* it takes, so we know for next time?
*/
ret = parport_poll_peripheral (port, mask, result, usec);
if (ret != 1)
return ret;
if (!port->physport->cad->timeout)
/* We may be in an interrupt handler, so we can't poll
* slowly anyway. */
return 1;
/* 40ms of slow polling. */
deadline = jiffies + msecs_to_jiffies(40);
while (time_before (jiffies, deadline)) {
int ret;
if (signal_pending (current))
return -EINTR;
/* Wait for 10ms (or until an interrupt occurs if
* the handler is set) */
if ((ret = parport_wait_event (port, msecs_to_jiffies(10))) < 0)
return ret;
status = parport_read_status (port);
if ((status & mask) == result)
return 0;
if (!ret) {
/* parport_wait_event didn't time out, but the
* peripheral wasn't actually ready either.
* Wait for another 10ms. */
schedule_timeout_interruptible(msecs_to_jiffies(10));
}
}
return 1;
}
#ifdef CONFIG_PARPORT_1284
/* Terminate a negotiated mode. */
static void parport_ieee1284_terminate (struct parport *port)
{
int r;
port = port->physport;
/* EPP terminates differently. */
switch (port->ieee1284.mode) {
case IEEE1284_MODE_EPP:
case IEEE1284_MODE_EPPSL:
case IEEE1284_MODE_EPPSWE:
/* Terminate from EPP mode. */
/* Event 68: Set nInit low */
parport_frob_control (port, PARPORT_CONTROL_INIT, 0);
udelay (50);
/* Event 69: Set nInit high, nSelectIn low */
parport_frob_control (port,
PARPORT_CONTROL_SELECT
| PARPORT_CONTROL_INIT,
PARPORT_CONTROL_SELECT
| PARPORT_CONTROL_INIT);
break;
case IEEE1284_MODE_ECP:
case IEEE1284_MODE_ECPRLE:
case IEEE1284_MODE_ECPSWE:
/* In ECP we can only terminate from fwd idle phase. */
if (port->ieee1284.phase != IEEE1284_PH_FWD_IDLE) {
/* Event 47: Set nInit high */
parport_frob_control (port,
PARPORT_CONTROL_INIT
| PARPORT_CONTROL_AUTOFD,
PARPORT_CONTROL_INIT
| PARPORT_CONTROL_AUTOFD);
/* Event 49: PError goes high */
r = parport_wait_peripheral (port,
PARPORT_STATUS_PAPEROUT,
PARPORT_STATUS_PAPEROUT);
if (r)
DPRINTK (KERN_INFO "%s: Timeout at event 49\n",
port->name);
parport_data_forward (port);
DPRINTK (KERN_DEBUG "%s: ECP direction: forward\n",
port->name);
port->ieee1284.phase = IEEE1284_PH_FWD_IDLE;
}
/* fall-though.. */
default:
/* Terminate from all other modes. */
/* Event 22: Set nSelectIn low, nAutoFd high */
parport_frob_control (port,
PARPORT_CONTROL_SELECT
| PARPORT_CONTROL_AUTOFD,
PARPORT_CONTROL_SELECT);
/* Event 24: nAck goes low */
r = parport_wait_peripheral (port, PARPORT_STATUS_ACK, 0);
if (r)
DPRINTK (KERN_INFO "%s: Timeout at event 24\n",
port->name);
/* Event 25: Set nAutoFd low */
parport_frob_control (port,
PARPORT_CONTROL_AUTOFD,
PARPORT_CONTROL_AUTOFD);
/* Event 27: nAck goes high */
r = parport_wait_peripheral (port,
PARPORT_STATUS_ACK,
PARPORT_STATUS_ACK);
if (r)
DPRINTK (KERN_INFO "%s: Timeout at event 27\n",
port->name);
/* Event 29: Set nAutoFd high */
parport_frob_control (port, PARPORT_CONTROL_AUTOFD, 0);
}
port->ieee1284.mode = IEEE1284_MODE_COMPAT;
port->ieee1284.phase = IEEE1284_PH_FWD_IDLE;
DPRINTK (KERN_DEBUG "%s: In compatibility (forward idle) mode\n",
port->name);
}
#endif /* IEEE1284 support */
/**
* parport_negotiate - negotiate an IEEE 1284 mode
* @port: port to use
* @mode: mode to negotiate to
*
* Use this to negotiate to a particular IEEE 1284 transfer mode.
* The @mode parameter should be one of the constants in
* parport.h starting %IEEE1284_MODE_xxx.
*
* The return value is 0 if the peripheral has accepted the
* negotiation to the mode specified, -1 if the peripheral is not
* IEEE 1284 compliant (or not present), or 1 if the peripheral
* has rejected the negotiation.
*/
int parport_negotiate (struct parport *port, int mode)
{
#ifndef CONFIG_PARPORT_1284
if (mode == IEEE1284_MODE_COMPAT)
return 0;
printk (KERN_ERR "parport: IEEE1284 not supported in this kernel\n");
return -1;
#else
int m = mode & ~IEEE1284_ADDR;
int r;
unsigned char xflag;
port = port->physport;
/* Is there anything to do? */
if (port->ieee1284.mode == mode)
return 0;
/* Is the difference just an address-or-not bit? */
if ((port->ieee1284.mode & ~IEEE1284_ADDR) == (mode & ~IEEE1284_ADDR)){
port->ieee1284.mode = mode;
return 0;
}
/* Go to compability forward idle mode */
if (port->ieee1284.mode != IEEE1284_MODE_COMPAT)
parport_ieee1284_terminate (port);
if (mode == IEEE1284_MODE_COMPAT)
/* Compatibility mode: no negotiation. */
return 0;
switch (mode) {
case IEEE1284_MODE_ECPSWE:
m = IEEE1284_MODE_ECP;
break;
case IEEE1284_MODE_EPPSL:
case IEEE1284_MODE_EPPSWE:
m = IEEE1284_MODE_EPP;
break;
case IEEE1284_MODE_BECP:
return -ENOSYS; /* FIXME (implement BECP) */
}
if (mode & IEEE1284_EXT_LINK)
m = 1<<7; /* request extensibility link */
port->ieee1284.phase = IEEE1284_PH_NEGOTIATION;
/* Start off with nStrobe and nAutoFd high, and nSelectIn low */
parport_frob_control (port,
PARPORT_CONTROL_STROBE
| PARPORT_CONTROL_AUTOFD
| PARPORT_CONTROL_SELECT,
PARPORT_CONTROL_SELECT);
udelay(1);
/* Event 0: Set data */
parport_data_forward (port);
parport_write_data (port, m);
udelay (400); /* Shouldn't need to wait this long. */
/* Event 1: Set nSelectIn high, nAutoFd low */
parport_frob_control (port,
PARPORT_CONTROL_SELECT
| PARPORT_CONTROL_AUTOFD,
PARPORT_CONTROL_AUTOFD);
/* Event 2: PError, Select, nFault go high, nAck goes low */
if (parport_wait_peripheral (port,
PARPORT_STATUS_ERROR
| PARPORT_STATUS_SELECT
| PARPORT_STATUS_PAPEROUT
| PARPORT_STATUS_ACK,
PARPORT_STATUS_ERROR
| PARPORT_STATUS_SELECT
| PARPORT_STATUS_PAPEROUT)) {
/* Timeout */
parport_frob_control (port,
PARPORT_CONTROL_SELECT
| PARPORT_CONTROL_AUTOFD,
PARPORT_CONTROL_SELECT);
DPRINTK (KERN_DEBUG
"%s: Peripheral not IEEE1284 compliant (0x%02X)\n",
port->name, parport_read_status (port));
port->ieee1284.phase = IEEE1284_PH_FWD_IDLE;
return -1; /* Not IEEE1284 compliant */
}
/* Event 3: Set nStrobe low */
parport_frob_control (port,
PARPORT_CONTROL_STROBE,
PARPORT_CONTROL_STROBE);
/* Event 4: Set nStrobe and nAutoFd high */
udelay (5);
parport_frob_control (port,
PARPORT_CONTROL_STROBE
| PARPORT_CONTROL_AUTOFD,
0);
/* Event 6: nAck goes high */
if (parport_wait_peripheral (port,
PARPORT_STATUS_ACK,
PARPORT_STATUS_ACK)) {
/* This shouldn't really happen with a compliant device. */
DPRINTK (KERN_DEBUG
"%s: Mode 0x%02x not supported? (0x%02x)\n",
port->name, mode, port->ops->read_status (port));
parport_ieee1284_terminate (port);
return 1;
}
xflag = parport_read_status (port) & PARPORT_STATUS_SELECT;
/* xflag should be high for all modes other than nibble (0). */
if (mode && !xflag) {
/* Mode not supported. */
DPRINTK (KERN_DEBUG "%s: Mode 0x%02x rejected by peripheral\n",
port->name, mode);
parport_ieee1284_terminate (port);
return 1;
}
/* More to do if we've requested extensibility link. */
if (mode & IEEE1284_EXT_LINK) {
m = mode & 0x7f;
udelay (1);
parport_write_data (port, m);
udelay (1);
/* Event 51: Set nStrobe low */
parport_frob_control (port,
PARPORT_CONTROL_STROBE,
PARPORT_CONTROL_STROBE);
/* Event 52: nAck goes low */
if (parport_wait_peripheral (port, PARPORT_STATUS_ACK, 0)) {
/* This peripheral is _very_ slow. */
DPRINTK (KERN_DEBUG
"%s: Event 52 didn't happen\n",
port->name);
parport_ieee1284_terminate (port);
return 1;
}
/* Event 53: Set nStrobe high */
parport_frob_control (port,
PARPORT_CONTROL_STROBE,
0);
/* Event 55: nAck goes high */
if (parport_wait_peripheral (port,
PARPORT_STATUS_ACK,
PARPORT_STATUS_ACK)) {
/* This shouldn't really happen with a compliant
* device. */
DPRINTK (KERN_DEBUG
"%s: Mode 0x%02x not supported? (0x%02x)\n",
port->name, mode,
port->ops->read_status (port));
parport_ieee1284_terminate (port);
return 1;
}
/* Event 54: Peripheral sets XFlag to reflect support */
xflag = parport_read_status (port) & PARPORT_STATUS_SELECT;
/* xflag should be high. */
if (!xflag) {
/* Extended mode not supported. */
DPRINTK (KERN_DEBUG "%s: Extended mode 0x%02x not "
"supported\n", port->name, mode);
parport_ieee1284_terminate (port);
return 1;
}
/* Any further setup is left to the caller. */
}
/* Mode is supported */
DPRINTK (KERN_DEBUG "%s: In mode 0x%02x\n", port->name, mode);
port->ieee1284.mode = mode;
/* But ECP is special */
if (!(mode & IEEE1284_EXT_LINK) && (m & IEEE1284_MODE_ECP)) {
port->ieee1284.phase = IEEE1284_PH_ECP_SETUP;
/* Event 30: Set nAutoFd low */
parport_frob_control (port,
PARPORT_CONTROL_AUTOFD,
PARPORT_CONTROL_AUTOFD);
/* Event 31: PError goes high. */
r = parport_wait_peripheral (port,
PARPORT_STATUS_PAPEROUT,
PARPORT_STATUS_PAPEROUT);
if (r) {
DPRINTK (KERN_INFO "%s: Timeout at event 31\n",
port->name);
}
port->ieee1284.phase = IEEE1284_PH_FWD_IDLE;
DPRINTK (KERN_DEBUG "%s: ECP direction: forward\n",
port->name);
} else switch (mode) {
case IEEE1284_MODE_NIBBLE:
case IEEE1284_MODE_BYTE:
port->ieee1284.phase = IEEE1284_PH_REV_IDLE;
break;
default:
port->ieee1284.phase = IEEE1284_PH_FWD_IDLE;
}
return 0;
#endif /* IEEE1284 support */
}
/* Acknowledge that the peripheral has data available.
* Events 18-20, in order to get from Reverse Idle phase
* to Host Busy Data Available.
* This will most likely be called from an interrupt.
* Returns zero if data was available.
*/
#ifdef CONFIG_PARPORT_1284
static int parport_ieee1284_ack_data_avail (struct parport *port)
{
if (parport_read_status (port) & PARPORT_STATUS_ERROR)
/* Event 18 didn't happen. */
return -1;
/* Event 20: nAutoFd goes high. */
port->ops->frob_control (port, PARPORT_CONTROL_AUTOFD, 0);
port->ieee1284.phase = IEEE1284_PH_HBUSY_DAVAIL;
return 0;
}
#endif /* IEEE1284 support */
/* Handle an interrupt. */
void parport_ieee1284_interrupt (int which, void *handle)
{
struct parport *port = handle;
parport_ieee1284_wakeup (port);
#ifdef CONFIG_PARPORT_1284
if (port->ieee1284.phase == IEEE1284_PH_REV_IDLE) {
/* An interrupt in this phase means that data
* is now available. */
DPRINTK (KERN_DEBUG "%s: Data available\n", port->name);
parport_ieee1284_ack_data_avail (port);
}
#endif /* IEEE1284 support */
}
/**
* parport_write - write a block of data to a parallel port
* @port: port to write to
* @buffer: data buffer (in kernel space)
* @len: number of bytes of data to transfer
*
* This will write up to @len bytes of @buffer to the port
* specified, using the IEEE 1284 transfer mode most recently
* negotiated to (using parport_negotiate()), as long as that
* mode supports forward transfers (host to peripheral).
*
* It is the caller's responsibility to ensure that the first
* @len bytes of @buffer are valid.
*
* This function returns the number of bytes transferred (if zero
* or positive), or else an error code.
*/
ssize_t parport_write (struct parport *port, const void *buffer, size_t len)
{
#ifndef CONFIG_PARPORT_1284
return port->ops->compat_write_data (port, buffer, len, 0);
#else
ssize_t retval;
int mode = port->ieee1284.mode;
int addr = mode & IEEE1284_ADDR;
size_t (*fn) (struct parport *, const void *, size_t, int);
/* Ignore the device-ID-request bit and the address bit. */
mode &= ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
/* Use the mode we're in. */
switch (mode) {
case IEEE1284_MODE_NIBBLE:
case IEEE1284_MODE_BYTE:
parport_negotiate (port, IEEE1284_MODE_COMPAT);
case IEEE1284_MODE_COMPAT:
DPRINTK (KERN_DEBUG "%s: Using compatibility mode\n",
port->name);
fn = port->ops->compat_write_data;
break;
case IEEE1284_MODE_EPP:
DPRINTK (KERN_DEBUG "%s: Using EPP mode\n", port->name);
if (addr) {
fn = port->ops->epp_write_addr;
} else {
fn = port->ops->epp_write_data;
}
break;
case IEEE1284_MODE_EPPSWE:
DPRINTK (KERN_DEBUG "%s: Using software-emulated EPP mode\n",
port->name);
if (addr) {
fn = parport_ieee1284_epp_write_addr;
} else {
fn = parport_ieee1284_epp_write_data;
}
break;
case IEEE1284_MODE_ECP:
case IEEE1284_MODE_ECPRLE:
DPRINTK (KERN_DEBUG "%s: Using ECP mode\n", port->name);
if (addr) {
fn = port->ops->ecp_write_addr;
} else {
fn = port->ops->ecp_write_data;
}
break;
case IEEE1284_MODE_ECPSWE:
DPRINTK (KERN_DEBUG "%s: Using software-emulated ECP mode\n",
port->name);
/* The caller has specified that it must be emulated,
* even if we have ECP hardware! */
if (addr) {
fn = parport_ieee1284_ecp_write_addr;
} else {
fn = parport_ieee1284_ecp_write_data;
}
break;
default:
DPRINTK (KERN_DEBUG "%s: Unknown mode 0x%02x\n", port->name,
port->ieee1284.mode);
return -ENOSYS;
}
retval = (*fn) (port, buffer, len, 0);
DPRINTK (KERN_DEBUG "%s: wrote %d/%d bytes\n", port->name, retval, len);
return retval;
#endif /* IEEE1284 support */
}
/**
* parport_read - read a block of data from a parallel port
* @port: port to read from
* @buffer: data buffer (in kernel space)
* @len: number of bytes of data to transfer
*
* This will read up to @len bytes of @buffer to the port
* specified, using the IEEE 1284 transfer mode most recently
* negotiated to (using parport_negotiate()), as long as that
* mode supports reverse transfers (peripheral to host).
*
* It is the caller's responsibility to ensure that the first
* @len bytes of @buffer are available to write to.
*
* This function returns the number of bytes transferred (if zero
* or positive), or else an error code.
*/
ssize_t parport_read (struct parport *port, void *buffer, size_t len)
{
#ifndef CONFIG_PARPORT_1284
printk (KERN_ERR "parport: IEEE1284 not supported in this kernel\n");
return -ENODEV;
#else
int mode = port->physport->ieee1284.mode;
int addr = mode & IEEE1284_ADDR;
size_t (*fn) (struct parport *, void *, size_t, int);
/* Ignore the device-ID-request bit and the address bit. */
mode &= ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
/* Use the mode we're in. */
switch (mode) {
case IEEE1284_MODE_COMPAT:
/* if we can tri-state use BYTE mode instead of NIBBLE mode,
* if that fails, revert to NIBBLE mode -- ought to store somewhere
* the device's ability to do BYTE mode reverse transfers, so we don't
* end up needlessly calling negotiate(BYTE) repeately.. (fb)
*/
if ((port->physport->modes & PARPORT_MODE_TRISTATE) &&
!parport_negotiate (port, IEEE1284_MODE_BYTE)) {
/* got into BYTE mode OK */
DPRINTK (KERN_DEBUG "%s: Using byte mode\n", port->name);
fn = port->ops->byte_read_data;
break;
}
if (parport_negotiate (port, IEEE1284_MODE_NIBBLE)) {
return -EIO;
}
/* fall through to NIBBLE */
case IEEE1284_MODE_NIBBLE:
DPRINTK (KERN_DEBUG "%s: Using nibble mode\n", port->name);
fn = port->ops->nibble_read_data;
break;
case IEEE1284_MODE_BYTE:
DPRINTK (KERN_DEBUG "%s: Using byte mode\n", port->name);
fn = port->ops->byte_read_data;
break;
case IEEE1284_MODE_EPP:
DPRINTK (KERN_DEBUG "%s: Using EPP mode\n", port->name);
if (addr) {
fn = port->ops->epp_read_addr;
} else {
fn = port->ops->epp_read_data;
}
break;
case IEEE1284_MODE_EPPSWE:
DPRINTK (KERN_DEBUG "%s: Using software-emulated EPP mode\n",
port->name);
if (addr) {
fn = parport_ieee1284_epp_read_addr;
} else {
fn = parport_ieee1284_epp_read_data;
}
break;
case IEEE1284_MODE_ECP:
case IEEE1284_MODE_ECPRLE:
DPRINTK (KERN_DEBUG "%s: Using ECP mode\n", port->name);
fn = port->ops->ecp_read_data;
break;
case IEEE1284_MODE_ECPSWE:
DPRINTK (KERN_DEBUG "%s: Using software-emulated ECP mode\n",
port->name);
fn = parport_ieee1284_ecp_read_data;
break;
default:
DPRINTK (KERN_DEBUG "%s: Unknown mode 0x%02x\n", port->name,
port->physport->ieee1284.mode);
return -ENOSYS;
}
return (*fn) (port, buffer, len, 0);
#endif /* IEEE1284 support */
}
/**
* parport_set_timeout - set the inactivity timeout for a device
* @dev: device on a port
* @inactivity: inactivity timeout (in jiffies)
*
* This sets the inactivity timeout for a particular device on a
* port. This affects functions like parport_wait_peripheral().
* The special value 0 means not to call schedule() while dealing
* with this device.
*
* The return value is the previous inactivity timeout.
*
* Any callers of parport_wait_event() for this device are woken
* up.
*/
long parport_set_timeout (struct pardevice *dev, long inactivity)
{
long int old = dev->timeout;
dev->timeout = inactivity;
if (dev->port->physport->cad == dev)
parport_ieee1284_wakeup (dev->port);
return old;
}
/* Exported symbols for modules. */
EXPORT_SYMBOL(parport_negotiate);
EXPORT_SYMBOL(parport_write);
EXPORT_SYMBOL(parport_read);
EXPORT_SYMBOL(parport_wait_peripheral);
EXPORT_SYMBOL(parport_wait_event);
EXPORT_SYMBOL(parport_set_timeout);
EXPORT_SYMBOL(parport_ieee1284_interrupt);
View Git Blame Copy Permalink