[RFC PATCH 0/2] Generic DMA bindings helpers for Device Tree
Cousson, Benoit
b-cousson at ti.com
Sat Jan 28 04:27:50 EST 2012
Hi All,
Here is a first RFC to introduce a generic binding for DMA
controller and DMA request along with a couple of basic helpers
functions.
The support is very limited since the a lot of DMA controllers in
ARM SoCs are far for being adapted to dmaengine. At least this is
the case for OMAP.
It is thus a little bit harder to handle that the same way GPIO is
doing thanks to the gpiolib and provide a dmaengine pointer to the
user.
For the moment the API is just returning the DMA controller device_node
to the driver + the DMA request number.
I added as well for legacy purpose the dma to resource API, because
it is still widely us in ARM SoC in general.
I found at least two custom DMA bindings that could be replaced by a
generic one for my point of view.
commit bf55499e6ee927e047feed85349365481289bd75
Stephen Warren <swarren at nvidia.com>
ASoC: Tegra I2S: Add device tree binding
commit 93ed55441245a39e3935f5cf1af3e22febcce905
Thomas Abraham <thomas.abraham at linaro.org>
DMA: PL330: Add device tree support
That generic DMA support is indeed pretty basic for the moment, but I
think it can still help a couple of platforms.
Comments are welcome.
Thanks,
Benoit
Benoit Cousson (2):
of: Add generic device tree DMA helpers
arm/dts: OMAP4: Add dma-controller and dma-request for I2C
Documentation/devicetree/bindings/dma/dma.txt | 44 +++++++++
arch/arm/boot/dts/omap4.dtsi | 15 +++
drivers/of/Kconfig | 5 +
drivers/of/Makefile | 1 +
drivers/of/dma.c | 130 +++++++++++++++++++++++++
include/linux/of_dma.h | 49 +++++++++
6 files changed, 244 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/dma/dma.txt
create mode 100644 drivers/of/dma.c
create mode 100644 include/linux/of_dma.h
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