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authorLinus Torvalds <torvalds@linux-foundation.org>2015-02-18 16:49:20 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2015-02-18 16:49:20 (GMT)
commitce1d3fde87d1a21f1ec1147dde32b2825dd3a276 (patch)
tree6ffab43e47e3a22a76bf9bf4efeecdf1b90dcb6f /Documentation/dmaengine
parent928fce2f6d8152d897790c1a5bbeef5642f69e0e (diff)
parent88987d2c7534a0269f567fb101e6d71a08f0f01d (diff)
Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma
Pull dmaengine updates from Vinod Koul: "This update brings: - the big cleanup up by Maxime for device control and slave capabilities. This makes the API much cleaner. - new IMG MDC driver by Andrew - new Renesas R-Car Gen2 DMA Controller driver by Laurent along with bunch of fixes on rcar drivers - odd fixes and updates spread over driver" * 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma: (130 commits) dmaengine: pl330: add DMA_PAUSE feature dmaengine: pl330: improve pl330_tx_status() function dmaengine: rcar-dmac: Disable channel 0 when using IOMMU dmaengine: rcar-dmac: Work around descriptor mode IOMMU errata dmaengine: rcar-dmac: Allocate hardware descriptors with DMAC device dmaengine: rcar-dmac: Fix oops due to unintialized list in error ISR dmaengine: rcar-dmac: Fix spinlock issues in interrupt dmaenegine: edma: fix sparse warnings dmaengine: rcar-dmac: Fix uninitialized variable usage dmaengine: shdmac: extend PM methods dmaengine: shdmac: use SET_RUNTIME_PM_OPS() dmaengine: pl330: fix bug that cause start the same descs in cyclic dmaengine: at_xdmac: allow muliple dwidths when doing slave transfers dmaengine: at_xdmac: simplify channel configuration stuff dmaengine: at_xdmac: introduce save_cc field dmaengine: at_xdmac: wait for in-progress transaction to complete after pausing a channel ioat: fail self-test if wait_for_completion times out dmaengine: dw: define DW_DMA_MAX_NR_MASTERS dmaengine: dw: amend description of dma_dev field dmatest: move src_off, dst_off, len inside loop ...
Diffstat (limited to 'Documentation/dmaengine')
-rw-r--r--Documentation/dmaengine/provider.txt97
1 files changed, 55 insertions, 42 deletions
diff --git a/Documentation/dmaengine/provider.txt b/Documentation/dmaengine/provider.txt
index 766658c..05d2280 100644
--- a/Documentation/dmaengine/provider.txt
+++ b/Documentation/dmaengine/provider.txt
@@ -113,6 +113,31 @@ need to initialize a few fields in there:
* channels: should be initialized as a list using the
INIT_LIST_HEAD macro for example
+ * src_addr_widths:
+ - should contain a bitmask of the supported source transfer width
+
+ * dst_addr_widths:
+ - should contain a bitmask of the supported destination transfer
+ width
+
+ * directions:
+ - should contain a bitmask of the supported slave directions
+ (i.e. excluding mem2mem transfers)
+
+ * residue_granularity:
+ - Granularity of the transfer residue reported to dma_set_residue.
+ - This can be either:
+ + Descriptor
+ -> Your device doesn't support any kind of residue
+ reporting. The framework will only know that a particular
+ transaction descriptor is done.
+ + Segment
+ -> Your device is able to report which chunks have been
+ transferred
+ + Burst
+ -> Your device is able to report which burst have been
+ transferred
+
* dev: should hold the pointer to the struct device associated
to your current driver instance.
@@ -274,48 +299,36 @@ supported.
account the current period.
- This function can be called in an interrupt context.
- * device_control
- - Used by client drivers to control and configure the channel it
- has a handle on.
- - Called with a command and an argument
- + The command is one of the values listed by the enum
- dma_ctrl_cmd. The valid commands are:
- + DMA_PAUSE
- + Pauses a transfer on the channel
- + This command should operate synchronously on the channel,
- pausing right away the work of the given channel
- + DMA_RESUME
- + Restarts a transfer on the channel
- + This command should operate synchronously on the channel,
- resuming right away the work of the given channel
- + DMA_TERMINATE_ALL
- + Aborts all the pending and ongoing transfers on the
- channel
- + This command should operate synchronously on the channel,
- terminating right away all the channels
- + DMA_SLAVE_CONFIG
- + Reconfigures the channel with passed configuration
- + This command should NOT perform synchronously, or on any
- currently queued transfers, but only on subsequent ones
- + In this case, the function will receive a
- dma_slave_config structure pointer as an argument, that
- will detail which configuration to use.
- + Even though that structure contains a direction field,
- this field is deprecated in favor of the direction
- argument given to the prep_* functions
- + FSLDMA_EXTERNAL_START
- + TODO: Why does that even exist?
- + The argument is an opaque unsigned long. This actually is a
- pointer to a struct dma_slave_config that should be used only
- in the DMA_SLAVE_CONFIG.
-
- * device_slave_caps
- - Called through the framework by client drivers in order to have
- an idea of what are the properties of the channel allocated to
- them.
- - Such properties are the buswidth, available directions, etc.
- - Required for every generic layer doing DMA transfers, such as
- ASoC.
+ * device_config
+ - Reconfigures the channel with the configuration given as
+ argument
+ - This command should NOT perform synchronously, or on any
+ currently queued transfers, but only on subsequent ones
+ - In this case, the function will receive a dma_slave_config
+ structure pointer as an argument, that will detail which
+ configuration to use.
+ - Even though that structure contains a direction field, this
+ field is deprecated in favor of the direction argument given to
+ the prep_* functions
+ - This call is mandatory for slave operations only. This should NOT be
+ set or expected to be set for memcpy operations.
+ If a driver support both, it should use this call for slave
+ operations only and not for memcpy ones.
+
+ * device_pause
+ - Pauses a transfer on the channel
+ - This command should operate synchronously on the channel,
+ pausing right away the work of the given channel
+
+ * device_resume
+ - Resumes a transfer on the channel
+ - This command should operate synchronously on the channel,
+ pausing right away the work of the given channel
+
+ * device_terminate_all
+ - Aborts all the pending and ongoing transfers on the channel
+ - This command should operate synchronously on the channel,
+ terminating right away all the channels
Misc notes (stuff that should be documented, but don't really know
where to put them)

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