[PATCH v2 0/3] DaVinci DMA engine conversion
Matt Porter
mporter at ti.com
Tue Aug 21 14:43:06 EDT 2012
Changes since v1:
- Add virt-dma support. Better error checks
and simplified descriptor handling.
- Fix support for multiple EDMA controllers
Tested on AM18x EVM with WL12xx on MMC1
This series begins the conversion of the DaVinci private
EDMA API implementation to a DMA engine driver and
converts two of the three in-kernel users of the private
EDMA API to DMA engine.
The approach taken is similar to the recent OMAP DMA
Engine conversion. The EDMA DMA Engine driver is a
wrapper around the existing private EDMA implementation
and registers the platform device within the driver.
This allows the conversion series to stand alone with
just the drivers and no changes to platform code. It
also allows peripheral drivers to continue to use the
private EDMA implementation until they are converted.
The EDMA DMA Engine driver supports slave transfers only
at this time. It is planned to add cyclic transfers in
support of audio peripherals.
There are three users of the private EDMA API in the
kernel now: davinci_mmc, spi-davinci, and davinci-mcasp.
This series provides DMA Engine conversions for the
davinci_mmc and spi-davinci drivers which use the
supported slave transfers.
This series has been tested on an AM18x EVM and
performance is comparable with the private EDMA
API implementations. Both MMC0 and MMC1 are tested
which handles the DA850/OMAP-L138/AM18x specific
case where MMC1 has DMA channels on a second EDMA
channel controller. Testing is needed on all DaVinci
platforms including DM355/365, DM644x/6x,
DA830/OMAP-L137/AM17x, and DA850/OMAP-L138/AM18x.
In order to ease the testing burden, I've pushed a
branch for each series release to my github tree
at https://github.com/ohporter/linux. The current
branch is edma-dmaengine-v2.
After this series, the current plan is to complete
the mcasp driver conversion which includes adding
cyclic dma support. This will then enable the
removal and refactoring of the private EDMA API
functionality into the EDMA DMA Engine driver.
Since EDMA is also used on the AM33xx family of
parts in mach-omap2/, the plan is to enable this
driver on that platform as well.
Matt Porter (3):
dmaengine: add TI EDMA DMA engine driver
mmc: davinci_mmc: convert to DMA engine API
spi: spi-davinci: convert to DMA engine API
drivers/dma/Kconfig | 10 +
drivers/dma/Makefile | 1 +
drivers/dma/edma.c | 684 ++++++++++++++++++++++++++++++++++++++++
drivers/mmc/host/davinci_mmc.c | 271 +++++-----------
drivers/spi/spi-davinci.c | 292 ++++++++---------
include/linux/edma.h | 29 ++
6 files changed, 936 insertions(+), 351 deletions(-)
create mode 100644 drivers/dma/edma.c
create mode 100644 include/linux/edma.h
--
1.7.9.5
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