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Date:      Mon, 31 May 2010 22:12:47 +0200
From:      Jakub Klama <jceel@semihalf.com>
To:        soc-status@freebsd.org
Subject:   [DMA Engine Framework] status report #1
Message-ID:  <C12C54A6-6474-435A-B4C6-9D3BFD81F388@semihalf.com>

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Done this week:
* Created early skeleton of API for DMA engine drivers=20
  (Milesone M1: in progress)
* Written basic working driver for DaVinci EDMA3 engine using above =
mentioned=20
  API (Milestone M2: in progress)
* Written basic character device driver to test some transfers
* Submitted first DMA transfers and got correct results. :-)

Plans for next week:
* Improve DMA engine drivers API:
  - get information from DMA engine about supported transfer types
  - think about some transfer validation mechanism (eg. "this transfer =
can't be
    done using this device" or "this is illegal transfer because address =
ranges
    overlap") [1]
* Write some skeleton of DMA engine API for use in various kernel =
subsystems
  and device drivers.
* Think about DMA transfer descriptor structure - can we simplify it?

Potential problems:
* [1] - transfer descriptors are somewhat complex and transfer =
validation
  can be complex too (checking address ranges, stride sizes/spacings,
  FIFO widths, etc on source and destination buffers)

--=20
Jakub Klama.=



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