dev.c

Go to the documentation of this file.

/*
 * dev.c
 *
 * DSP-BIOS Bridge driver support functions for TI OMAP processors.
 *
 * Implementation of Bridge Bridge driver device operations.
 *
 * Copyright (C) 2005-2006 Texas Instruments, Inc.
 *
 * This package is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */
#include <linux/types.h>
#include <linux/list.h>

/*  ----------------------------------- Host OS */
#include <dspbridge/host_os.h>

/*  ----------------------------------- DSP/BIOS Bridge */
#include <dspbridge/dbdefs.h>

/*  ----------------------------------- Platform Manager */
#include <dspbridge/cod.h>
#include <dspbridge/drv.h>
#include <dspbridge/proc.h>
#include <dspbridge/dmm.h>

/*  ----------------------------------- Resource Manager */
#include <dspbridge/mgr.h>
#include <dspbridge/node.h>

/*  ----------------------------------- Others */
#include <dspbridge/dspapi.h>   /* DSP API version info. */

#include <dspbridge/chnl.h>
#include <dspbridge/io.h>
#include <dspbridge/msg.h>
#include <dspbridge/cmm.h>
#include <dspbridge/dspdeh.h>

/*  ----------------------------------- This */
#include <dspbridge/dev.h>

/*  ----------------------------------- Defines, Data Structures, Typedefs */

#define MAKEVERSION(major, minor)   (major * 10 + minor)
#define BRD_API_VERSION     MAKEVERSION(BRD_API_MAJOR_VERSION,  \
                BRD_API_MINOR_VERSION)

/* The Bridge device object: */
struct dev_object {
    struct list_head link;  /* Link to next dev_object. */
    u8 dev_type;        /* Device Type */
    struct cfg_devnode *dev_node_obj;   /* Platform specific dev id */
    /* Bridge Context Handle */
    struct bridge_dev_context *bridge_context;
    /* Function interface to Bridge driver. */
    struct bridge_drv_interface bridge_interface;
    struct brd_object *lock_owner;  /* Client with exclusive access. */
    struct cod_manager *cod_mgr;    /* Code manager handle. */
    struct chnl_mgr *chnl_mgr;  /* Channel manager. */
    struct deh_mgr *deh_mgr;    /* DEH manager. */
    struct msg_mgr *msg_mgr;    /* Message manager. */
    struct io_mgr *iomgr;   /* IO manager (CHNL, msg_ctrl) */
    struct cmm_object *cmm_mgr; /* SM memory manager. */
    struct dmm_object *dmm_mgr; /* Dynamic memory manager. */
    u32 word_size;      /* DSP word size: quick access. */
    struct drv_object *drv_obj; /* Driver Object */
    /* List of Processors attached to this device */
    struct list_head proc_list;
    struct node_mgr *node_mgr;
};

struct drv_ext {
    struct list_head link;
    char sz_string[MAXREGPATHLENGTH];
};

/*  ----------------------------------- Function Prototypes */
static int fxn_not_implemented(int arg, ...);
static int init_cod_mgr(struct dev_object *dev_obj);
static void store_interface_fxns(struct bridge_drv_interface *drv_fxns,
                 struct bridge_drv_interface *intf_fxns);
/*
 *  ======== dev_brd_write_fxn ========
 *  Purpose:
 *      Exported function to be used as the COD write function.  This function
 *      is passed a handle to a DEV_hObject, then calls the
 *      device's bridge_brd_write() function.
 */
u32 dev_brd_write_fxn(void *arb, u32 dsp_add, void *host_buf,
              u32 ul_num_bytes, u32 mem_space)
{
    struct dev_object *dev_obj = (struct dev_object *)arb;
    u32 ul_written = 0;
    int status;

    if (dev_obj) {
        /* Require of BrdWrite() */
        status = (*dev_obj->bridge_interface.brd_write) (
                    dev_obj->bridge_context, host_buf,
                    dsp_add, ul_num_bytes, mem_space);
        /* Special case of getting the address only */
        if (ul_num_bytes == 0)
            ul_num_bytes = 1;
        if (!status)
            ul_written = ul_num_bytes;

    }
    return ul_written;
}

/*
 *  ======== dev_create_device ========
 *  Purpose:
 *      Called by the operating system to load the PM Bridge Driver for a
 *      PM board (device).
 */
int dev_create_device(struct dev_object **device_obj,
                 const char *driver_file_name,
                 struct cfg_devnode *dev_node_obj)
{
    struct cfg_hostres *host_res;
    struct bridge_drv_interface *drv_fxns = NULL;
    struct dev_object *dev_obj = NULL;
    struct chnl_mgrattrs mgr_attrs;
    struct io_attrs io_mgr_attrs;
    u32 num_windows;
    struct drv_object *hdrv_obj = NULL;
    struct drv_data *drv_datap = dev_get_drvdata(bridge);
    int status = 0;

    status = drv_request_bridge_res_dsp((void *)&host_res);

    if (status) {
        dev_dbg(bridge, "%s: Failed to reserve bridge resources\n",
            __func__);
        goto leave;
    }

    /*  Get the Bridge driver interface functions */
    bridge_drv_entry(&drv_fxns, driver_file_name);

    /* Retrieve the Object handle from the driver data */
    if (drv_datap && drv_datap->drv_object) {
        hdrv_obj = drv_datap->drv_object;
    } else {
        status = -EPERM;
        pr_err("%s: Failed to retrieve the object handle\n", __func__);
    }

    /* Create the device object, and pass a handle to the Bridge driver for
     * storage. */
    if (!status) {
        dev_obj = kzalloc(sizeof(struct dev_object), GFP_KERNEL);
        if (dev_obj) {
            /* Fill out the rest of the Dev Object structure: */
            dev_obj->dev_node_obj = dev_node_obj;
            dev_obj->cod_mgr = NULL;
            dev_obj->chnl_mgr = NULL;
            dev_obj->deh_mgr = NULL;
            dev_obj->lock_owner = NULL;
            dev_obj->word_size = DSPWORDSIZE;
            dev_obj->drv_obj = hdrv_obj;
            dev_obj->dev_type = DSP_UNIT;
            /* Store this Bridge's interface functions, based on its
             * version. */
            store_interface_fxns(drv_fxns,
                        &dev_obj->bridge_interface);

            /* Call fxn_dev_create() to get the Bridge's device
             * context handle. */
            status = (dev_obj->bridge_interface.dev_create)
                (&dev_obj->bridge_context, dev_obj,
                 host_res);
        } else {
            status = -ENOMEM;
        }
    }
    /* Attempt to create the COD manager for this device: */
    if (!status)
        status = init_cod_mgr(dev_obj);

    /* Attempt to create the channel manager for this device: */
    if (!status) {
        mgr_attrs.max_channels = CHNL_MAXCHANNELS;
        io_mgr_attrs.birq = host_res->birq_registers;
        io_mgr_attrs.irq_shared =
            (host_res->birq_attrib & CFG_IRQSHARED);
        io_mgr_attrs.word_size = DSPWORDSIZE;
        mgr_attrs.word_size = DSPWORDSIZE;
        num_windows = host_res->num_mem_windows;
        if (num_windows) {
            /* Assume last memory window is for CHNL */
            io_mgr_attrs.shm_base = host_res->mem_base[1] +
                host_res->offset_for_monitor;
            io_mgr_attrs.sm_length =
                host_res->mem_length[1] -
                host_res->offset_for_monitor;
        } else {
            io_mgr_attrs.shm_base = 0;
            io_mgr_attrs.sm_length = 0;
            pr_err("%s: No memory reserved for shared structures\n",
                   __func__);
        }
        status = chnl_create(&dev_obj->chnl_mgr, dev_obj, &mgr_attrs);
        if (status == -ENOSYS) {
            /* It's OK for a device not to have a channel
             * manager: */
            status = 0;
        }
        /* Create CMM mgr even if Msg Mgr not impl. */
        status = cmm_create(&dev_obj->cmm_mgr,
                    (struct dev_object *)dev_obj, NULL);
        /* Only create IO manager if we have a channel manager */
        if (!status && dev_obj->chnl_mgr) {
            status = io_create(&dev_obj->iomgr, dev_obj,
                       &io_mgr_attrs);
        }
        /* Only create DEH manager if we have an IO manager */
        if (!status) {
            /* Instantiate the DEH module */
            status = bridge_deh_create(&dev_obj->deh_mgr, dev_obj);
        }
        /* Create DMM mgr . */
        status = dmm_create(&dev_obj->dmm_mgr,
                    (struct dev_object *)dev_obj, NULL);
    }
    /* Add the new DEV_Object to the global list: */
    if (!status)
        status = drv_insert_dev_object(hdrv_obj, dev_obj);

    /* Create the Processor List */
    if (!status)
        INIT_LIST_HEAD(&dev_obj->proc_list);
leave:
    /*  If all went well, return a handle to the dev object;
     *  else, cleanup and return NULL in the OUT parameter. */
    if (!status) {
        *device_obj = dev_obj;
    } else {
        if (dev_obj) {
            if (dev_obj->cod_mgr)
                cod_delete(dev_obj->cod_mgr);
            if (dev_obj->dmm_mgr)
                dmm_destroy(dev_obj->dmm_mgr);
            kfree(dev_obj);
        }

        *device_obj = NULL;
    }

    return status;
}

/*
 *  ======== dev_create2 ========
 *  Purpose:
 *      After successful loading of the image from api_init_complete2
 *      (PROC Auto_Start) or proc_load this fxn is called. This creates
 *      the Node Manager and updates the DEV Object.
 */
int dev_create2(struct dev_object *hdev_obj)
{
    int status = 0;
    struct dev_object *dev_obj = hdev_obj;

    /* There can be only one Node Manager per DEV object */
    status = node_create_mgr(&dev_obj->node_mgr, hdev_obj);
    if (status)
        dev_obj->node_mgr = NULL;

    return status;
}

/*
 *  ======== dev_destroy2 ========
 *  Purpose:
 *      Destroys the Node manager for this device.
 */
int dev_destroy2(struct dev_object *hdev_obj)
{
    int status = 0;
    struct dev_object *dev_obj = hdev_obj;

    if (dev_obj->node_mgr) {
        if (node_delete_mgr(dev_obj->node_mgr))
            status = -EPERM;
        else
            dev_obj->node_mgr = NULL;

    }

    return status;
}

/*
 *  ======== dev_destroy_device ========
 *  Purpose:
 *      Destroys the channel manager for this device, if any, calls
 *      bridge_dev_destroy(), and then attempts to unload the Bridge module.
 */
int dev_destroy_device(struct dev_object *hdev_obj)
{
    int status = 0;
    struct dev_object *dev_obj = hdev_obj;

    if (hdev_obj) {
        if (dev_obj->cod_mgr) {
            cod_delete(dev_obj->cod_mgr);
            dev_obj->cod_mgr = NULL;
        }

        if (dev_obj->node_mgr) {
            node_delete_mgr(dev_obj->node_mgr);
            dev_obj->node_mgr = NULL;
        }

        /* Free the io, channel, and message managers for this board: */
        if (dev_obj->iomgr) {
            io_destroy(dev_obj->iomgr);
            dev_obj->iomgr = NULL;
        }
        if (dev_obj->chnl_mgr) {
            chnl_destroy(dev_obj->chnl_mgr);
            dev_obj->chnl_mgr = NULL;
        }
        if (dev_obj->msg_mgr) {
            msg_delete(dev_obj->msg_mgr);
            dev_obj->msg_mgr = NULL;
        }

        if (dev_obj->deh_mgr) {
            /* Uninitialize DEH module. */
            bridge_deh_destroy(dev_obj->deh_mgr);
            dev_obj->deh_mgr = NULL;
        }
        if (dev_obj->cmm_mgr) {
            cmm_destroy(dev_obj->cmm_mgr, true);
            dev_obj->cmm_mgr = NULL;
        }

        if (dev_obj->dmm_mgr) {
            dmm_destroy(dev_obj->dmm_mgr);
            dev_obj->dmm_mgr = NULL;
        }

        /* Call the driver's bridge_dev_destroy() function: */
        /* Require of DevDestroy */
        if (dev_obj->bridge_context) {
            status = (*dev_obj->bridge_interface.dev_destroy)
                (dev_obj->bridge_context);
            dev_obj->bridge_context = NULL;
        } else
            status = -EPERM;
        if (!status) {
            /* Remove this DEV_Object from the global list: */
            drv_remove_dev_object(dev_obj->drv_obj, dev_obj);
            /* Free The library * LDR_FreeModule
             * (dev_obj->module_obj); */
            /* Free this dev object: */
            kfree(dev_obj);
            dev_obj = NULL;
        }
    } else {
        status = -EFAULT;
    }

    return status;
}

/*
 *  ======== dev_get_chnl_mgr ========
 *  Purpose:
 *      Retrieve the handle to the channel manager handle created for this
 *      device.
 */
int dev_get_chnl_mgr(struct dev_object *hdev_obj,
                struct chnl_mgr **mgr)
{
    int status = 0;
    struct dev_object *dev_obj = hdev_obj;

    if (hdev_obj) {
        *mgr = dev_obj->chnl_mgr;
    } else {
        *mgr = NULL;
        status = -EFAULT;
    }

    return status;
}

/*
 *  ======== dev_get_cmm_mgr ========
 *  Purpose:
 *      Retrieve the handle to the shared memory manager created for this
 *      device.
 */
int dev_get_cmm_mgr(struct dev_object *hdev_obj,
               struct cmm_object **mgr)
{
    int status = 0;
    struct dev_object *dev_obj = hdev_obj;

    if (hdev_obj) {
        *mgr = dev_obj->cmm_mgr;
    } else {
        *mgr = NULL;
        status = -EFAULT;
    }

    return status;
}

/*
 *  ======== dev_get_dmm_mgr ========
 *  Purpose:
 *      Retrieve the handle to the dynamic memory manager created for this
 *      device.
 */
int dev_get_dmm_mgr(struct dev_object *hdev_obj,
               struct dmm_object **mgr)
{
    int status = 0;
    struct dev_object *dev_obj = hdev_obj;

    if (hdev_obj) {
        *mgr = dev_obj->dmm_mgr;
    } else {
        *mgr = NULL;
        status = -EFAULT;
    }

    return status;
}

/*
 *  ======== dev_get_cod_mgr ========
 *  Purpose:
 *      Retrieve the COD manager create for this device.
 */
int dev_get_cod_mgr(struct dev_object *hdev_obj,
               struct cod_manager **cod_mgr)
{
    int status = 0;
    struct dev_object *dev_obj = hdev_obj;

    if (hdev_obj) {
        *cod_mgr = dev_obj->cod_mgr;
    } else {
        *cod_mgr = NULL;
        status = -EFAULT;
    }

    return status;
}

/*
 *  ========= dev_get_deh_mgr ========
 */
int dev_get_deh_mgr(struct dev_object *hdev_obj,
               struct deh_mgr **deh_manager)
{
    int status = 0;

    if (hdev_obj) {
        *deh_manager = hdev_obj->deh_mgr;
    } else {
        *deh_manager = NULL;
        status = -EFAULT;
    }
    return status;
}

/*
 *  ======== dev_get_dev_node ========
 *  Purpose:
 *      Retrieve the platform specific device ID for this device.
 */
int dev_get_dev_node(struct dev_object *hdev_obj,
                struct cfg_devnode **dev_nde)
{
    int status = 0;
    struct dev_object *dev_obj = hdev_obj;

    if (hdev_obj) {
        *dev_nde = dev_obj->dev_node_obj;
    } else {
        *dev_nde = NULL;
        status = -EFAULT;
    }

    return status;
}

/*
 *  ======== dev_get_first ========
 *  Purpose:
 *      Retrieve the first Device Object handle from an internal linked list
 *      DEV_OBJECTs maintained by DEV.
 */
struct dev_object *dev_get_first(void)
{
    struct dev_object *dev_obj = NULL;

    dev_obj = (struct dev_object *)drv_get_first_dev_object();

    return dev_obj;
}

/*
 *  ======== dev_get_intf_fxns ========
 *  Purpose:
 *      Retrieve the Bridge interface function structure for the loaded driver.
 *      if_fxns != NULL.
 */
int dev_get_intf_fxns(struct dev_object *hdev_obj,
                 struct bridge_drv_interface **if_fxns)
{
    int status = 0;
    struct dev_object *dev_obj = hdev_obj;

    if (hdev_obj) {
        *if_fxns = &dev_obj->bridge_interface;
    } else {
        *if_fxns = NULL;
        status = -EFAULT;
    }

    return status;
}

/*
 *  ========= dev_get_io_mgr ========
 */
int dev_get_io_mgr(struct dev_object *hdev_obj,
              struct io_mgr **io_man)
{
    int status = 0;

    if (hdev_obj) {
        *io_man = hdev_obj->iomgr;
    } else {
        *io_man = NULL;
        status = -EFAULT;
    }

    return status;
}

/*
 *  ======== dev_get_next ========
 *  Purpose:
 *      Retrieve the next Device Object handle from an internal linked list
 *      of DEV_OBJECTs maintained by DEV, after having previously called
 *      dev_get_first() and zero or more dev_get_next
 */
struct dev_object *dev_get_next(struct dev_object *hdev_obj)
{
    struct dev_object *next_dev_object = NULL;

    if (hdev_obj) {
        next_dev_object = (struct dev_object *)
            drv_get_next_dev_object((u32) hdev_obj);
    }

    return next_dev_object;
}

/*
 *  ========= dev_get_msg_mgr ========
 */
void dev_get_msg_mgr(struct dev_object *hdev_obj, struct msg_mgr **msg_man)
{
    *msg_man = hdev_obj->msg_mgr;
}

/*
 *  ======== dev_get_node_manager ========
 *  Purpose:
 *      Retrieve the Node Manager Handle
 */
int dev_get_node_manager(struct dev_object *hdev_obj,
                struct node_mgr **node_man)
{
    int status = 0;
    struct dev_object *dev_obj = hdev_obj;

    if (hdev_obj) {
        *node_man = dev_obj->node_mgr;
    } else {
        *node_man = NULL;
        status = -EFAULT;
    }

    return status;
}

/*
 *  ======== dev_get_symbol ========
 */
int dev_get_symbol(struct dev_object *hdev_obj,
              const char *str_sym, u32 * pul_value)
{
    int status = 0;
    struct cod_manager *cod_mgr;

    if (hdev_obj) {
        status = dev_get_cod_mgr(hdev_obj, &cod_mgr);
        if (cod_mgr)
            status = cod_get_sym_value(cod_mgr, (char *)str_sym,
                           pul_value);
        else
            status = -EFAULT;
    }

    return status;
}

/*
 *  ======== dev_get_bridge_context ========
 *  Purpose:
 *      Retrieve the Bridge Context handle, as returned by the
 *      bridge_dev_create fxn.
 */
int dev_get_bridge_context(struct dev_object *hdev_obj,
                   struct bridge_dev_context **phbridge_context)
{
    int status = 0;
    struct dev_object *dev_obj = hdev_obj;

    if (hdev_obj) {
        *phbridge_context = dev_obj->bridge_context;
    } else {
        *phbridge_context = NULL;
        status = -EFAULT;
    }

    return status;
}

/*
 *  ======== dev_notify_clients ========
 *  Purpose:
 *      Notify all clients of this device of a change in device status.
 */
int dev_notify_clients(struct dev_object *dev_obj, u32 ret)
{
    struct list_head *curr;

    /*
     * FIXME: this code needs struct proc_object to have a list_head
     * at the beginning. If not, this can go horribly wrong.
     */
    list_for_each(curr, &dev_obj->proc_list)
        proc_notify_clients((void *)curr, ret);

    return 0;
}

/*
 *  ======== dev_remove_device ========
 */
int dev_remove_device(struct cfg_devnode *dev_node_obj)
{
    struct dev_object *hdev_obj;    /* handle to device object */
    int status = 0;
    struct drv_data *drv_datap = dev_get_drvdata(bridge);

    if (!drv_datap)
        status = -ENODATA;

    if (!dev_node_obj)
        status = -EFAULT;

    /* Retrieve the device object handle originally stored with
     * the dev_node: */
    if (!status) {
        /* check the device string and then store dev object */
        if (!strcmp((char *)((struct drv_ext *)dev_node_obj)->sz_string,
                                "TIOMAP1510")) {
            hdev_obj = drv_datap->dev_object;
            /* Destroy the device object. */
            status = dev_destroy_device(hdev_obj);
        } else {
            status = -EPERM;
        }
    }

    if (status)
        pr_err("%s: Failed, status 0x%x\n", __func__, status);

    return status;
}

/*
 *  ======== dev_set_chnl_mgr ========
 *  Purpose:
 *      Set the channel manager for this device.
 */
int dev_set_chnl_mgr(struct dev_object *hdev_obj,
                struct chnl_mgr *hmgr)
{
    int status = 0;
    struct dev_object *dev_obj = hdev_obj;

    if (hdev_obj)
        dev_obj->chnl_mgr = hmgr;
    else
        status = -EFAULT;

    return status;
}

/*
 *  ======== dev_set_msg_mgr ========
 *  Purpose:
 *      Set the message manager for this device.
 */
void dev_set_msg_mgr(struct dev_object *hdev_obj, struct msg_mgr *hmgr)
{
    hdev_obj->msg_mgr = hmgr;
}

/*
 *  ======== dev_start_device ========
 *  Purpose:
 *      Initializes the new device with the BRIDGE environment.
 */
int dev_start_device(struct cfg_devnode *dev_node_obj)
{
    struct dev_object *hdev_obj = NULL; /* handle to 'Bridge Device */
    /* Bridge driver filename */
    char *bridge_file_name = "UMA";
    int status;
    struct mgr_object *hmgr_obj = NULL;
    struct drv_data *drv_datap = dev_get_drvdata(bridge);

    /* Given all resources, create a device object. */
    status = dev_create_device(&hdev_obj, bridge_file_name,
                   dev_node_obj);
    if (!status) {
        /* Store away the hdev_obj with the DEVNODE */
        if (!drv_datap || !dev_node_obj) {
            status = -EFAULT;
            pr_err("%s: Failed, status 0x%x\n", __func__, status);
        } else if (!(strcmp((char *)dev_node_obj, "TIOMAP1510"))) {
            drv_datap->dev_object = (void *) hdev_obj;
        }
        if (!status) {
            /* Create the Manager Object */
            status = mgr_create(&hmgr_obj, dev_node_obj);
            if (status && !(strcmp((char *)dev_node_obj,
                            "TIOMAP1510"))) {
                /* Ensure the device extension is NULL */
                drv_datap->dev_object = NULL;
            }
        }
        if (status) {
            /* Clean up */
            dev_destroy_device(hdev_obj);
            hdev_obj = NULL;
        }
    }

    return status;
}

/*
 *  ======== fxn_not_implemented ========
 *  Purpose:
 *      Takes the place of a Bridge Null Function.
 *  Parameters:
 *      Multiple, optional.
 *  Returns:
 *      -ENOSYS:   Always.
 */
static int fxn_not_implemented(int arg, ...)
{
    return -ENOSYS;
}

/*
 *  ======== init_cod_mgr ========
 *  Purpose:
 *      Create a COD manager for this device.
 *  Parameters:
 *      dev_obj:             Pointer to device object created with
 *                              dev_create_device()
 *  Returns:
 *      0:                Success.
 *      -EFAULT:            Invalid hdev_obj.
 *  Requires:
 *      Should only be called once by dev_create_device() for a given DevObject.
 *  Ensures:
 */
static int init_cod_mgr(struct dev_object *dev_obj)
{
    int status = 0;
    char *sz_dummy_file = "dummy";

    status = cod_create(&dev_obj->cod_mgr, sz_dummy_file);

    return status;
}

/*
 *  ======== dev_insert_proc_object ========
 *  Purpose:
 *      Insert a ProcObject into the list maintained by DEV.
 *  Parameters:
 *      p_proc_object:        Ptr to ProcObject to insert.
 *      dev_obj:         Ptr to Dev Object where the list is.
  *     already_attached:  Ptr to return the bool
 *  Returns:
 *      0:           If successful.
 *  Requires:
 *      List Exists
 *      hdev_obj is Valid handle
 *      DEV Initialized
 *      already_attached != NULL
 *      proc_obj != 0
 *  Ensures:
 *      0 and List is not Empty.
 */
int dev_insert_proc_object(struct dev_object *hdev_obj,
                  u32 proc_obj, bool *already_attached)
{
    struct dev_object *dev_obj = (struct dev_object *)hdev_obj;

    if (!list_empty(&dev_obj->proc_list))
        *already_attached = true;

    /* Add DevObject to tail. */
    /*
     * FIXME: this code needs struct proc_object to have a list_head
     * at the beginning. If not, this can go horribly wrong.
     */
    list_add_tail((struct list_head *)proc_obj, &dev_obj->proc_list);

    return 0;
}

/*
 *  ======== dev_remove_proc_object ========
 *  Purpose:
 *      Search for and remove a Proc object from the given list maintained
 *      by the DEV
 *  Parameters:
 *      p_proc_object:        Ptr to ProcObject to insert.
 *      dev_obj          Ptr to Dev Object where the list is.
 *  Returns:
 *      0:            If successful.
 *  Requires:
 *      List exists and is not empty
 *      proc_obj != 0
 *      hdev_obj is a valid Dev handle.
 *  Ensures:
 *  Details:
 *      List will be deleted when the DEV is destroyed.
 */
int dev_remove_proc_object(struct dev_object *hdev_obj, u32 proc_obj)
{
    int status = -EPERM;
    struct list_head *cur_elem;
    struct dev_object *dev_obj = (struct dev_object *)hdev_obj;

    /* Search list for dev_obj: */
    list_for_each(cur_elem, &dev_obj->proc_list) {
        if ((u32) cur_elem == proc_obj) {
            list_del(cur_elem);
            status = 0;
            break;
        }
    }

    return status;
}

int dev_get_dev_type(struct dev_object *dev_obj, u8 *dev_type)
{
    *dev_type = dev_obj->dev_type;
    return 0;
}

/*
 *  ======== store_interface_fxns ========
 *  Purpose:
 *      Copy the Bridge's interface functions into the device object,
 *      ensuring that fxn_not_implemented() is set for:
 *
 *      1. All Bridge function pointers which are NULL; and
 *      2. All function slots in the struct dev_object structure which have no
 *         corresponding slots in the the Bridge's interface, because the Bridge
 *         is of an *older* version.
 *  Parameters:
 *      intf_fxns:      Interface fxn Structure of the Bridge's Dev Object.
 *      drv_fxns:      Interface Fxns offered by the Bridge during DEV_Create().
 *  Returns:
 *  Requires:
 *      Input pointers are valid.
 *      Bridge driver is *not* written for a newer DSP API.
 *  Ensures:
 *      All function pointers in the dev object's fxn interface are not NULL.
 */
static void store_interface_fxns(struct bridge_drv_interface *drv_fxns,
                 struct bridge_drv_interface *intf_fxns)
{
    u32 bridge_version;

    /* Local helper macro: */
#define  STORE_FXN(cast, pfn) \
    (intf_fxns->pfn = ((drv_fxns->pfn != NULL) ? drv_fxns->pfn : \
    (cast)fxn_not_implemented))

    bridge_version = MAKEVERSION(drv_fxns->brd_api_major_version,
                     drv_fxns->brd_api_minor_version);
    intf_fxns->brd_api_major_version = drv_fxns->brd_api_major_version;
    intf_fxns->brd_api_minor_version = drv_fxns->brd_api_minor_version;
    /* Install functions up to DSP API version .80 (first alpha): */
    if (bridge_version > 0) {
        STORE_FXN(fxn_dev_create, dev_create);
        STORE_FXN(fxn_dev_destroy, dev_destroy);
        STORE_FXN(fxn_dev_ctrl, dev_cntrl);
        STORE_FXN(fxn_brd_monitor, brd_monitor);
        STORE_FXN(fxn_brd_start, brd_start);
        STORE_FXN(fxn_brd_stop, brd_stop);
        STORE_FXN(fxn_brd_status, brd_status);
        STORE_FXN(fxn_brd_read, brd_read);
        STORE_FXN(fxn_brd_write, brd_write);
        STORE_FXN(fxn_brd_setstate, brd_set_state);
        STORE_FXN(fxn_brd_memcopy, brd_mem_copy);
        STORE_FXN(fxn_brd_memwrite, brd_mem_write);
        STORE_FXN(fxn_brd_memmap, brd_mem_map);
        STORE_FXN(fxn_brd_memunmap, brd_mem_un_map);
        STORE_FXN(fxn_chnl_create, chnl_create);
        STORE_FXN(fxn_chnl_destroy, chnl_destroy);
        STORE_FXN(fxn_chnl_open, chnl_open);
        STORE_FXN(fxn_chnl_close, chnl_close);
        STORE_FXN(fxn_chnl_addioreq, chnl_add_io_req);
        STORE_FXN(fxn_chnl_getioc, chnl_get_ioc);
        STORE_FXN(fxn_chnl_cancelio, chnl_cancel_io);
        STORE_FXN(fxn_chnl_flushio, chnl_flush_io);
        STORE_FXN(fxn_chnl_getinfo, chnl_get_info);
        STORE_FXN(fxn_chnl_getmgrinfo, chnl_get_mgr_info);
        STORE_FXN(fxn_chnl_idle, chnl_idle);
        STORE_FXN(fxn_chnl_registernotify, chnl_register_notify);
        STORE_FXN(fxn_io_create, io_create);
        STORE_FXN(fxn_io_destroy, io_destroy);
        STORE_FXN(fxn_io_onloaded, io_on_loaded);
        STORE_FXN(fxn_io_getprocload, io_get_proc_load);
        STORE_FXN(fxn_msg_create, msg_create);
        STORE_FXN(fxn_msg_createqueue, msg_create_queue);
        STORE_FXN(fxn_msg_delete, msg_delete);
        STORE_FXN(fxn_msg_deletequeue, msg_delete_queue);
        STORE_FXN(fxn_msg_get, msg_get);
        STORE_FXN(fxn_msg_put, msg_put);
        STORE_FXN(fxn_msg_registernotify, msg_register_notify);
        STORE_FXN(fxn_msg_setqueueid, msg_set_queue_id);
    }
    /* Add code for any additional functions in newerBridge versions here */
#undef  STORE_FXN
}