Documentation/rapidio/tsi721.txt

   1 RapidIO subsystem mport driver for IDT Tsi721 PCI Express-to-SRIO bridge.
   2 =========================================================================
   3
   4 I. Overview
   5
   6 This driver implements all currently defined RapidIO mport callback functions.
   7 It supports maintenance read and write operations, inbound and outbound RapidIO
   8 doorbells, inbound maintenance port-writes and RapidIO messaging.
   9
  10 To generate SRIO maintenance transactions this driver uses one of Tsi721 DMA
  11 channels. This mechanism provides access to larger range of hop counts and
  12 destination IDs without need for changes in outbound window translation.
  13
  14 RapidIO messaging support uses dedicated messaging channels for each mailbox.
  15 For inbound messages this driver uses destination ID matching to forward messages
  16 into the corresponding message queue. Messaging callbacks are implemented to be
  17 fully compatible with RIONET driver (Ethernet over RapidIO messaging services).
  18
  19 1. Module parameters:
  20 - 'dbg_level' - This parameter allows to control amount of debug information
  21         generated by this device driver. This parameter is formed by set of
  22         This parameter can be changed bit masks that correspond to the specific
  23         functional block.
  24         For mask definitions see 'drivers/rapidio/devices/tsi721.h'
  25         This parameter can be changed dynamically.
  26         Use CONFIG_RAPIDIO_DEBUG=y to enable debug output at the top level.
  27
  28 II. Known problems
  29
  30   None.
  31
  32 III. DMA Engine Support
  33
  34 Tsi721 mport driver supports DMA data transfers between local system memory and
  35 remote RapidIO devices. This functionality is implemented according to SLAVE
  36 mode API defined by common Linux kernel DMA Engine framework.
  37
  38 Depending on system requirements RapidIO DMA operations can be included/excluded
  39 by setting CONFIG_RAPIDIO_DMA_ENGINE option. Tsi721 miniport driver uses seven
  40 out of eight available BDMA channels to support DMA data transfers.
  41 One BDMA channel is reserved for generation of maintenance read/write requests.
  42
  43 If Tsi721 mport driver have been built with RAPIDIO_DMA_ENGINE support included,
  44 this driver will accept DMA-specific module parameter:
  45   "dma_desc_per_channel" - defines number of hardware buffer descriptors used by
  46                            each BDMA channel of Tsi721 (by default - 128).
  47
  48 IV. Version History
  49
  50   1.1.0 - DMA operations re-worked to support data scatter/gather lists larger
  51           than hardware buffer descriptors ring.
  52   1.0.0 - Initial driver release.
  53
  54 V.  License
  55 -----------------------------------------------
  56
  57   Copyright(c) 2011 Integrated Device Technology, Inc. All rights reserved.
  58
  59   This program is free software; you can redistribute it and/or modify it
  60   under the terms of the GNU General Public License as published by the Free
  61   Software Foundation; either version 2 of the License, or (at your option)
  62   any later version.
  63
  64   This program is distributed in the hope that it will be useful, but WITHOUT
  65   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  66   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  67   more details.
  68
  69   You should have received a copy of the GNU General Public License along with
  70   this program; if not, write to the Free Software Foundation, Inc.,
  71   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.