3bfb1d20b5
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 dw_dmac_regs.h * Define and use controller-specific dma_slave data * Fix up a few outdated comments * Define hardware registers as structs (doesn't generate better code, unfortunately, but it looks nicer.)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>
92 lines
2.2 KiB
Plaintext
92 lines
2.2 KiB
Plaintext
#
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# DMA engine configuration
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#
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menuconfig DMADEVICES
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bool "DMA Engine support"
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depends on !HIGHMEM64G && HAS_DMA
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help
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DMA engines can do asynchronous data transfers without
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involving the host CPU. Currently, this framework can be
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used to offload memory copies in the network stack and
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RAID operations in the MD driver. This menu only presents
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DMA Device drivers supported by the configured arch, it may
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be empty in some cases.
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if DMADEVICES
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comment "DMA Devices"
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config INTEL_IOATDMA
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tristate "Intel I/OAT DMA support"
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depends on PCI && X86
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select DMA_ENGINE
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select DCA
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help
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Enable support for the Intel(R) I/OAT DMA engine present
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in recent Intel Xeon chipsets.
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Say Y here if you have such a chipset.
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If unsure, say N.
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config INTEL_IOP_ADMA
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tristate "Intel IOP ADMA support"
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depends on ARCH_IOP32X || ARCH_IOP33X || ARCH_IOP13XX
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select ASYNC_CORE
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select DMA_ENGINE
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help
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Enable support for the Intel(R) IOP Series RAID engines.
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config DW_DMAC
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tristate "Synopsys DesignWare AHB DMA support"
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depends on AVR32
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select DMA_ENGINE
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default y if CPU_AT32AP7000
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help
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Support the Synopsys DesignWare AHB DMA controller. This
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can be integrated in chips such as the Atmel AT32ap7000.
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config FSL_DMA
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bool "Freescale MPC85xx/MPC83xx DMA support"
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depends on PPC
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select DMA_ENGINE
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---help---
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Enable support for the Freescale DMA engine. Now, it support
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MPC8560/40, MPC8555, MPC8548 and MPC8641 processors.
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The MPC8349, MPC8360 is also supported.
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config MV_XOR
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bool "Marvell XOR engine support"
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depends on PLAT_ORION
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select ASYNC_CORE
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select DMA_ENGINE
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---help---
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Enable support for the Marvell XOR engine.
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config DMA_ENGINE
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bool
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comment "DMA Clients"
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depends on DMA_ENGINE
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config NET_DMA
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bool "Network: TCP receive copy offload"
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depends on DMA_ENGINE && NET
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default (INTEL_IOATDMA || FSL_DMA)
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help
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This enables the use of DMA engines in the network stack to
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offload receive copy-to-user operations, freeing CPU cycles.
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Say Y here if you enabled INTEL_IOATDMA or FSL_DMA, otherwise
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say N.
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config DMATEST
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tristate "DMA Test client"
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depends on DMA_ENGINE
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help
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Simple DMA test client. Say N unless you're debugging a
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DMA Device driver.
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endif
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