drivers/staging/tidspbridge/pmgr/io.c

   1 /*
   2  * io.c
   3  *
   4  * DSP-BIOS Bridge driver support functions for TI OMAP processors.
   5  *
   6  * IO manager interface: Manages IO between CHNL and msg_ctrl.
   7  *
   8  * Copyright (C) 2005-2006 Texas Instruments, Inc.
   9  *
  10  * This package is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  *
  14  * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  16  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  17  */
  18 #include <linux/types.h>
  19
  20 /*  ----------------------------------- Host OS */
  21 #include <dspbridge/host_os.h>
  22
  23 /*  ----------------------------------- DSP/BIOS Bridge */
  24 #include <dspbridge/dbdefs.h>
  25
  26 /*  ----------------------------------- Trace & Debug */
  27 #include <dspbridge/dbc.h>
  28
  29 /*  ----------------------------------- Platform Manager */
  30 #include <dspbridge/dev.h>
  31
  32 /*  ----------------------------------- This */
  33 #include <ioobj.h>
  34 #include <dspbridge/io.h>
  35
  36 /*  ----------------------------------- Globals */
  37 static u32 refs;
  38
  39 /*
  40  *  ======== io_create ========
  41  *  Purpose:
  42  *      Create an IO manager object, responsible for managing IO between
  43  *      CHNL and msg_ctrl
  44  */
  45 int io_create(struct io_mgr **io_man, struct dev_object *hdev_obj,
  46                      const struct io_attrs *mgr_attrts)
  47 {
  48         struct bridge_drv_interface *intf_fxns;
  49         struct io_mgr *hio_mgr = NULL;
  50         struct io_mgr_ *pio_mgr = NULL;
  51         int status = 0;
  52
  53         DBC_REQUIRE(refs > 0);
  54         DBC_REQUIRE(io_man != NULL);
  55         DBC_REQUIRE(mgr_attrts != NULL);
  56
  57         *io_man = NULL;
  58
  59         /* A memory base of 0 implies no memory base: */
  60         if ((mgr_attrts->shm_base != 0) && (mgr_attrts->sm_length == 0))
  61                 status = -EINVAL;
  62
  63         if (mgr_attrts->word_size == 0)
  64                 status = -EINVAL;
  65
  66         if (!status) {
  67                 dev_get_intf_fxns(hdev_obj, &intf_fxns);
  68
  69                 /* Let Bridge channel module finish the create: */
  70                 status = (*intf_fxns->io_create) (&hio_mgr, hdev_obj,
  71                                                       mgr_attrts);
  72
  73                 if (!status) {
  74                         pio_mgr = (struct io_mgr_ *)hio_mgr;
  75                         pio_mgr->intf_fxns = intf_fxns;
  76                         pio_mgr->dev_obj = hdev_obj;
  77
  78                         /* Return the new channel manager handle: */
  79                         *io_man = hio_mgr;
  80                 }
  81         }
  82
  83         return status;
  84 }
  85
  86 /*
  87  *  ======== io_destroy ========
  88  *  Purpose:
  89  *      Delete IO manager.
  90  */
  91 int io_destroy(struct io_mgr *hio_mgr)
  92 {
  93         struct bridge_drv_interface *intf_fxns;
  94         struct io_mgr_ *pio_mgr = (struct io_mgr_ *)hio_mgr;
  95         int status;
  96
  97         DBC_REQUIRE(refs > 0);
  98
  99         intf_fxns = pio_mgr->intf_fxns;
 100
 101         /* Let Bridge channel module destroy the io_mgr: */
 102         status = (*intf_fxns->io_destroy) (hio_mgr);
 103
 104         return status;
 105 }
 106
 107 /*
 108  *  ======== io_exit ========
 109  *  Purpose:
 110  *      Discontinue usage of the IO module.
 111  */
 112 void io_exit(void)
 113 {
 114         DBC_REQUIRE(refs > 0);
 115
 116         refs--;
 117
 118         DBC_ENSURE(refs >= 0);
 119 }
 120
 121 /*
 122  *  ======== io_init ========
 123  *  Purpose:
 124  *      Initialize the IO module's private state.
 125  */
 126 bool io_init(void)
 127 {
 128         bool ret = true;
 129
 130         DBC_REQUIRE(refs >= 0);
 131
 132         if (ret)
 133                 refs++;
 134
 135         DBC_ENSURE((ret && (refs > 0)) || (!ret && (refs >= 0)));
 136
 137         return ret;
 138 }