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 II. Known problems
  20
  21   None.
  22
  23 III. DMA Engine Support
  24
  25 Tsi721 mport driver supports DMA data transfers between local system memory and
  26 remote RapidIO devices. This functionality is implemented according to SLAVE
  27 mode API defined by common Linux kernel DMA Engine framework.
  28
  29 Depending on system requirements RapidIO DMA operations can be included/excluded
  30 by setting CONFIG_RAPIDIO_DMA_ENGINE option. Tsi721 miniport driver uses seven
  31 out of eight available BDMA channels to support DMA data transfers.
  32 One BDMA channel is reserved for generation of maintenance read/write requests.
  33
  34 If Tsi721 mport driver have been built with RAPIDIO_DMA_ENGINE support included,
  35 this driver will accept DMA-specific module parameter:
  36   "dma_desc_per_channel" - defines number of hardware buffer descriptors used by
  37                            each BDMA channel of Tsi721 (by default - 128).
  38
  39 IV. Version History
  40
  41   1.1.0 - DMA operations re-worked to support data scatter/gather lists larger
  42           than hardware buffer descriptors ring.
  43   1.0.0 - Initial driver release.
  44
  45 V.  License
  46 -----------------------------------------------
  47
  48   Copyright(c) 2011 Integrated Device Technology, Inc. All rights reserved.
  49
  50   This program is free software; you can redistribute it and/or modify it
  51   under the terms of the GNU General Public License as published by the Free
  52   Software Foundation; either version 2 of the License, or (at your option)
  53   any later version.
  54
  55   This program is distributed in the hope that it will be useful, but WITHOUT
  56   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  57   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  58   more details.
  59
  60   You should have received a copy of the GNU General Public License along with
  61   this program; if not, write to the Free Software Foundation, Inc.,
  62   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.