Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 819 insertions, 0 deletions

diff --git a/drivers/parport/ieee1284.c b/drivers/parport/ieee1284.c
new file mode 100644
index 000000000000..694bae162fed
--- /dev/null
+++ b/drivers/parport/ieee1284.c
@@ -0,0 +1,819 @@
+/* $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/config.h>
+#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 one immediately.  If it times out, it returns
+ *      a value greater than zero.  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 zero 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 + (HZ + 24) / 25;
+        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, (HZ + 99) / 100)) < 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. */
+                        __set_current_state (TASK_INTERRUPTIBLE);
+                        schedule_timeout ((HZ+ 99) / 100);
+                }
+        }
+
+        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 pt_regs *regs)
+{
+        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);