linux/drivers/dma/Kconfig
Haavard Skinnemoen 3bfb1d20b5 dmaengine: Driver for the Synopsys DesignWare DMA controller
This adds a driver for the Synopsys DesignWare DMA controller (aka
DMACA on AVR32 systems.) This DMA controller can be found integrated
on the AT32AP7000 chip and is primarily meant for peripheral DMA
transfer, but can also be used for memory-to-memory transfers.

This patch is based on a driver from David Brownell which was based on
an older version of the DMA Engine framework. It also implements the
proposed extensions to the DMA Engine API for slave DMA operations.

The dmatest client shows no problems, but there may still be room for
improvement performance-wise. DMA slave transfer performance is
definitely "good enough"; reading 100 MiB from an SD card running at ~20
MHz yields ~7.2 MiB/s average transfer rate.

Full documentation for this controller can be found in the Synopsys
DW AHB DMAC Databook:

http://www.synopsys.com/designware/docs/iip/DW_ahb_dmac/latest/doc/dw_ahb_dmac_db.pdf

The controller has lots of implementation options, so it's usually a
good idea to check the data sheet of the chip it's intergrated on as
well. The AT32AP7000 data sheet can be found here:

http://www.atmel.com/dyn/products/datasheets.asp?family_id=682


Changes since v4:
  * Use client_count instead of dma_chan_is_in_use()
  * Add missing include
  * Unmap buffers unless client told us not to

Changes since v3:
  * Update to latest DMA engine and DMA slave APIs
  * Embed the hw descriptor into the sw descriptor
  * Clean up and update MODULE_DESCRIPTION, copyright date, etc.

Changes since v2:
  * Dequeue all pending transfers in terminate_all()
  * Rename dw_dmac.h -> dw_dmac_regs.h
  * Define and use controller-specific dma_slave data
  * Fix up a few outdated comments
  * Define hardware registers as structs (doesn't generate better
    code, unfortunately, but it looks nicer.)
  * Get number of channels from platform_data instead of hardcoding it
    based on CONFIG_WHATEVER_CPU.
  * Give slave clients exclusive access to the channel

Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>,
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2008-07-08 11:59:42 -07:00

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#
# DMA engine configuration
#
menuconfig DMADEVICES
bool "DMA Engine support"
depends on !HIGHMEM64G && HAS_DMA
help
DMA engines can do asynchronous data transfers without
involving the host CPU. Currently, this framework can be
used to offload memory copies in the network stack and
RAID operations in the MD driver. This menu only presents
DMA Device drivers supported by the configured arch, it may
be empty in some cases.
if DMADEVICES
comment "DMA Devices"
config INTEL_IOATDMA
tristate "Intel I/OAT DMA support"
depends on PCI && X86
select DMA_ENGINE
select DCA
help
Enable support for the Intel(R) I/OAT DMA engine present
in recent Intel Xeon chipsets.
Say Y here if you have such a chipset.
If unsure, say N.
config INTEL_IOP_ADMA
tristate "Intel IOP ADMA support"
depends on ARCH_IOP32X || ARCH_IOP33X || ARCH_IOP13XX
select ASYNC_CORE
select DMA_ENGINE
help
Enable support for the Intel(R) IOP Series RAID engines.
config DW_DMAC
tristate "Synopsys DesignWare AHB DMA support"
depends on AVR32
select DMA_ENGINE
default y if CPU_AT32AP7000
help
Support the Synopsys DesignWare AHB DMA controller. This
can be integrated in chips such as the Atmel AT32ap7000.
config FSL_DMA
bool "Freescale MPC85xx/MPC83xx DMA support"
depends on PPC
select DMA_ENGINE
---help---
Enable support for the Freescale DMA engine. Now, it support
MPC8560/40, MPC8555, MPC8548 and MPC8641 processors.
The MPC8349, MPC8360 is also supported.
config MV_XOR
bool "Marvell XOR engine support"
depends on PLAT_ORION
select ASYNC_CORE
select DMA_ENGINE
---help---
Enable support for the Marvell XOR engine.
config DMA_ENGINE
bool
comment "DMA Clients"
depends on DMA_ENGINE
config NET_DMA
bool "Network: TCP receive copy offload"
depends on DMA_ENGINE && NET
default (INTEL_IOATDMA || FSL_DMA)
help
This enables the use of DMA engines in the network stack to
offload receive copy-to-user operations, freeing CPU cycles.
Say Y here if you enabled INTEL_IOATDMA or FSL_DMA, otherwise
say N.
config DMATEST
tristate "DMA Test client"
depends on DMA_ENGINE
help
Simple DMA test client. Say N unless you're debugging a
DMA Device driver.
endif