linux-imx

// SPDX-License-Identifier: GPL-2.0

/* IEEE-1284 operations for parport.

 *

 * This file is for generic IEEE 1284 operations.  The idea is that

 * they are used by the low-level drivers.  If they have a special way

 * of doing something, they can provide their own routines (and put

 * the function pointers in port->ops); if not, they can just use these

 * as a fallback.

 *

 * Note: Make no assumptions about hardware or architecture in this file!

 *

 * Author: Tim Waugh <tim@cyberelk.demon.co.uk>

 * Fixed AUTOFD polarity in ecp_forward_to_reverse().  Fred Barnes, 1999

 * Software emulated EPP fixes, Fred Barnes, 04/2001.

 */

​

​

#include <linux/module.h>

#include <linux/parport.h>

#include <linux/delay.h>

#include <linux/sched/signal.h>

#include <linux/uaccess.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

​

/***                                *

 * One-way data transfer functions. *

 *                                ***/

​

/* Compatibility mode. */

size_t parport_ieee1284_write_compat (struct parport *port,

                      const void *buffer, size_t len,

                      int flags)

{

    int no_irq = 1;

    ssize_t count = 0;

    const unsigned char *addr = buffer;

    unsigned char byte;

    struct pardevice *dev = port->physport->cad;

    unsigned char ctl = (PARPORT_CONTROL_SELECT

                 | PARPORT_CONTROL_INIT);

​

    if (port->irq != PARPORT_IRQ_NONE) {

        parport_enable_irq (port);

        no_irq = 0;

    }

​

    port->physport->ieee1284.phase = IEEE1284_PH_FWD_DATA;

    parport_write_control (port, ctl);

    parport_data_forward (port);

    while (count < len) {

        unsigned long expire = jiffies + dev->timeout;

        long wait = msecs_to_jiffies(10);

        unsigned char mask = (PARPORT_STATUS_ERROR

                      | PARPORT_STATUS_BUSY);

        unsigned char val = (PARPORT_STATUS_ERROR

                     | PARPORT_STATUS_BUSY);

​

        /* Wait until the peripheral's ready */

        do {

            /* Is the peripheral ready yet? */

            if (!parport_wait_peripheral (port, mask, val))

                /* Skip the loop */

                goto ready;

​

            /* Is the peripheral upset? */

            if ((parport_read_status (port) &

                 (PARPORT_STATUS_PAPEROUT |

                  PARPORT_STATUS_SELECT |

                  PARPORT_STATUS_ERROR))

                != (PARPORT_STATUS_SELECT |

                PARPORT_STATUS_ERROR))

                /* If nFault is asserted (i.e. no

                 * error) and PAPEROUT and SELECT are

                 * just red herrings, give the driver

                 * a chance to check it's happy with

                 * that before continuing. */

                goto stop;

​

            /* Have we run out of time? */

            if (!time_before (jiffies, expire))

                break;