release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/staging/tidspbridge/pmgr/chnl.c

   1 /*
   2  * chnl.c
   3  *
   4  * DSP-BIOS Bridge driver support functions for TI OMAP processors.
   5  *
   6  * DSP API channel interface: multiplexes data streams through the single
   7  * physical link managed by a Bridge Bridge driver.
   8  *
   9  * Copyright (C) 2005-2006 Texas Instruments, Inc.
  10  *
  11  * This package is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License version 2 as
  13  * published by the Free Software Foundation.
  14  *
  15  * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  17  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  18  */
  19
  20 #include <linux/types.h>
  21 /*  ----------------------------------- Host OS */
  22 #include <dspbridge/host_os.h>
  23
  24 /*  ----------------------------------- DSP/BIOS Bridge */
  25 #include <dspbridge/dbdefs.h>
  26
  27 /*  ----------------------------------- Trace & Debug */
  28 #include <dspbridge/dbc.h>
  29
  30 /*  ----------------------------------- OS Adaptation Layer */
  31 #include <dspbridge/cfg.h>
  32 #include <dspbridge/sync.h>
  33
  34 /*  ----------------------------------- Platform Manager */
  35 #include <dspbridge/proc.h>
  36 #include <dspbridge/dev.h>
  37
  38 /*  ----------------------------------- Others */
  39 #include <dspbridge/chnlpriv.h>
  40 #include <chnlobj.h>
  41
  42 /*  ----------------------------------- This */
  43 #include <dspbridge/chnl.h>
  44
  45 /*  ----------------------------------- Globals */
  46 static u32 refs;
  47
  48 /*
  49  *  ======== chnl_create ========
  50  *  Purpose:
  51  *      Create a channel manager object, responsible for opening new channels
  52  *      and closing old ones for a given 'Bridge board.
  53  */
  54 int chnl_create(struct chnl_mgr **channel_mgr,
  55                        struct dev_object *hdev_obj,
  56                        const struct chnl_mgrattrs *mgr_attrts)
  57 {
  58         int status;
  59         struct chnl_mgr *hchnl_mgr;
  60         struct chnl_mgr_ *chnl_mgr_obj = NULL;
  61
  62         DBC_REQUIRE(refs > 0);
  63         DBC_REQUIRE(channel_mgr != NULL);
  64         DBC_REQUIRE(mgr_attrts != NULL);
  65
  66         *channel_mgr = NULL;
  67
  68         /* Validate args: */
  69         if ((0 < mgr_attrts->max_channels) &&
  70             (mgr_attrts->max_channels <= CHNL_MAXCHANNELS))
  71                 status = 0;
  72         else if (mgr_attrts->max_channels == 0)
  73                 status = -EINVAL;
  74         else
  75                 status = -ECHRNG;
  76
  77         if (mgr_attrts->word_size == 0)
  78                 status = -EINVAL;
  79
  80         if (!status) {
  81                 status = dev_get_chnl_mgr(hdev_obj, &hchnl_mgr);
  82                 if (!status && hchnl_mgr != NULL)
  83                         status = -EEXIST;
  84
  85         }
  86
  87         if (!status) {
  88                 struct bridge_drv_interface *intf_fxns;
  89                 dev_get_intf_fxns(hdev_obj, &intf_fxns);
  90                 /* Let Bridge channel module finish the create: */
  91                 status = (*intf_fxns->pfn_chnl_create) (&hchnl_mgr, hdev_obj,
  92                                                         mgr_attrts);
  93                 if (!status) {
  94                         /* Fill in DSP API channel module's fields of the
  95                          * chnl_mgr structure */
  96                         chnl_mgr_obj = (struct chnl_mgr_ *)hchnl_mgr;
  97                         chnl_mgr_obj->intf_fxns = intf_fxns;
  98                         /* Finally, return the new channel manager handle: */
  99                         *channel_mgr = hchnl_mgr;
 100                 }
 101         }
 102
 103         DBC_ENSURE(status || chnl_mgr_obj);
 104
 105         return status;
 106 }
 107
 108 /*
 109  *  ======== chnl_destroy ========
 110  *  Purpose:
 111  *      Close all open channels, and destroy the channel manager.
 112  */
 113 int chnl_destroy(struct chnl_mgr *hchnl_mgr)
 114 {
 115         struct chnl_mgr_ *chnl_mgr_obj = (struct chnl_mgr_ *)hchnl_mgr;
 116         struct bridge_drv_interface *intf_fxns;
 117         int status;
 118
 119         DBC_REQUIRE(refs > 0);
 120
 121         if (chnl_mgr_obj) {
 122                 intf_fxns = chnl_mgr_obj->intf_fxns;
 123                 /* Let Bridge channel module destroy the chnl_mgr: */
 124                 status = (*intf_fxns->pfn_chnl_destroy) (hchnl_mgr);
 125         } else {
 126                 status = -EFAULT;
 127         }
 128
 129         return status;
 130 }
 131
 132 /*
 133  *  ======== chnl_exit ========
 134  *  Purpose:
 135  *      Discontinue usage of the CHNL module.
 136  */
 137 void chnl_exit(void)
 138 {
 139         DBC_REQUIRE(refs > 0);
 140
 141         refs--;
 142
 143         DBC_ENSURE(refs >= 0);
 144 }
 145
 146 /*
 147  *  ======== chnl_init ========
 148  *  Purpose:
 149  *      Initialize the CHNL module's private state.
 150  */
 151 bool chnl_init(void)
 152 {
 153         bool ret = true;
 154
 155         DBC_REQUIRE(refs >= 0);
 156
 157         if (ret)
 158                 refs++;
 159
 160         DBC_ENSURE((ret && (refs > 0)) || (!ret && (refs >= 0)));
 161
 162         return ret;
 163 }