linux-imx

/*

 * This file is subject to the terms and conditions of the GNU General Public

 * License.  See the file "COPYING" in the main directory of this archive

 * for more details.

 *

 * Copyright (C) 2005-2006 Silicon Graphics, Inc.  All Rights Reserved.

 */

​

/* This file contains the master driver module for use by SGI IOC4 subdrivers.

 *

 * It allocates any resources shared between multiple subdevices, and

 * provides accessor functions (where needed) and the like for those

 * resources.  It also provides a mechanism for the subdevice modules

 * to support loading and unloading.

 *

 * Non-shared resources (e.g. external interrupt A_INT_OUT register page

 * alias, serial port and UART registers) are handled by the subdevice

 * modules themselves.

 *

 * This is all necessary because IOC4 is not implemented as a multi-function

 * PCI device, but an amalgamation of disparate registers for several

 * types of device (ATA, serial, external interrupts).  The normal

 * resource management in the kernel doesn't have quite the right interfaces

 * to handle this situation (e.g. multiple modules can't claim the same

 * PCI ID), thus this IOC4 master module.

 */

​

#include <linux/errno.h>

#include <linux/module.h>

#include <linux/pci.h>

#include <linux/ioc4.h>

#include <linux/ktime.h>

#include <linux/slab.h>

#include <linux/mutex.h>

#include <linux/time.h>

#include <asm/io.h>

​

/***************

 * Definitions *

 ***************/

​

/* Tweakable values */

​

/* PCI bus speed detection/calibration */

#define IOC4_CALIBRATE_COUNT 63     /* Calibration cycle period */

#define IOC4_CALIBRATE_CYCLES 256   /* Average over this many cycles */

#define IOC4_CALIBRATE_DISCARD 2    /* Discard first few cycles */

#define IOC4_CALIBRATE_LOW_MHZ 25   /* Lower bound on bus speed sanity */

#define IOC4_CALIBRATE_HIGH_MHZ 75  /* Upper bound on bus speed sanity */

#define IOC4_CALIBRATE_DEFAULT_MHZ 66   /* Assumed if sanity check fails */

​

/************************

 * Submodule management *

 ************************/

​

static DEFINE_MUTEX(ioc4_mutex);

​

static LIST_HEAD(ioc4_devices);

static LIST_HEAD(ioc4_submodules);

​

/* Register an IOC4 submodule */

int

ioc4_register_submodule(struct ioc4_submodule *is)

{

    struct ioc4_driver_data *idd;

​

    mutex_lock(&ioc4_mutex);

    list_add(&is->is_list, &ioc4_submodules);

​

    /* Initialize submodule for each IOC4 */

    if (!is->is_probe)

        goto out;

​

    list_for_each_entry(idd, &ioc4_devices, idd_list) {

        if (is->is_probe(idd)) {

            printk(KERN_WARNING

                   "%s: IOC4 submodule %s probe failed "

                   "for pci_dev %s",

                   __func__, module_name(is->is_owner),

                   pci_name(idd->idd_pdev));

        }

    }

 out:

    mutex_unlock(&ioc4_mutex);

    return 0;

}

​

/* Unregister an IOC4 submodule */

void

ioc4_unregister_submodule(struct ioc4_submodule *is)

{

    struct ioc4_driver_data *idd;