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authorLinus Torvalds <torvalds@linux-foundation.org>2016-01-13 10:59:52 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-01-13 10:59:52 -0800
commitd6a322774cb7096ca683fc46ddc9482e02ee6133 (patch)
tree0e5b95d9899eefa5c58f23af8ecadd7e93010586 /Documentation
parent4c257ec37bc365614933c7f0a7fe9b0688dfd1e7 (diff)
parent8b648436eb45c1f561164b24aafd35fb2bee9cfc (diff)
Merge tag 'dmaengine-4.5-rc1' of git://git.infradead.org/users/vkoul/slave-dma
Pull dmaengine updates from Vinod Koul: "This round we have few new features, new driver and updates to few drivers. The new features to dmaengine core are: - Synchronized transfer termination API to terminate the dmaengine transfers in synchronized and async fashion as required by users. We have its user now in ALSA dmaengine lib, img, at_xdma, axi_dmac drivers. - Universal API for channel request and start consolidation of request flows. It's user is ompa-dma driver. - Introduce reuse of descriptors and use in pxa_dma driver Add/Remove: - New STM32 DMA driver - Removal of unused R-Car HPB-DMAC driver Updates: - ti-dma-crossbar updates for supporting eDMA - tegra-apb pm updates - idma64 - mv_xor updates - ste_dma updates" * tag 'dmaengine-4.5-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (54 commits) dmaengine: mv_xor: add suspend/resume support dmaengine: mv_xor: de-duplicate mv_chan_set_mode*() dmaengine: mv_xor: remove mv_xor_chan->current_type field dmaengine: omap-dma: Add support for DMA filter mapping to slave devices dmaengine: edma: Add support for DMA filter mapping to slave devices dmaengine: core: Introduce new, universal API to request a channel dmaengine: core: Move and merge the code paths using private_candidate dmaengine: core: Skip mask matching when it is not provided to private_candidate dmaengine: mdc: Correct terminate_all handling dmaengine: edma: Add probe callback to edma_tptc_driver dmaengine: dw: fix potential memory leak in dw_dma_parse_dt() dmaengine: stm32-dma: Fix unchecked deference of chan->desc dmaengine: sh: Remove unused R-Car HPB-DMAC driver dmaengine: usb-dmac: Document SoC specific compatibility strings ste_dma40: Delete an unnecessary variable initialisation in d40_probe() ste_dma40: Delete another unnecessary check in d40_probe() ste_dma40: Delete an unnecessary check before the function call "kmem_cache_destroy" dmaengine: tegra-apb: Free interrupts before killing tasklets dmaengine: tegra-apb: Update driver to use GFP_NOWAIT dmaengine: tegra-apb: Only save channel state for those in use ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/dma/renesas,usb-dmac.txt10
-rw-r--r--Documentation/devicetree/bindings/dma/stm32-dma.txt82
-rw-r--r--Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt6
-rw-r--r--Documentation/dmaengine/client.txt59
-rw-r--r--Documentation/dmaengine/provider.txt20
5 files changed, 155 insertions, 22 deletions
diff --git a/Documentation/devicetree/bindings/dma/renesas,usb-dmac.txt b/Documentation/devicetree/bindings/dma/renesas,usb-dmac.txt
index 040f365954cc..e7780a186a36 100644
--- a/Documentation/devicetree/bindings/dma/renesas,usb-dmac.txt
+++ b/Documentation/devicetree/bindings/dma/renesas,usb-dmac.txt
@@ -1,7 +1,13 @@
* Renesas USB DMA Controller Device Tree bindings
Required Properties:
-- compatible: must contain "renesas,usb-dmac"
+-compatible: "renesas,<soctype>-usb-dmac", "renesas,usb-dmac" as fallback.
+ Examples with soctypes are:
+ - "renesas,r8a7790-usb-dmac" (R-Car H2)
+ - "renesas,r8a7791-usb-dmac" (R-Car M2-W)
+ - "renesas,r8a7793-usb-dmac" (R-Car M2-N)
+ - "renesas,r8a7794-usb-dmac" (R-Car E2)
+ - "renesas,r8a7795-usb-dmac" (R-Car H3)
- reg: base address and length of the registers block for the DMAC
- interrupts: interrupt specifiers for the DMAC, one for each entry in
interrupt-names.
@@ -15,7 +21,7 @@ Required Properties:
Example: R8A7790 (R-Car H2) USB-DMACs
usb_dmac0: dma-controller@e65a0000 {
- compatible = "renesas,usb-dmac";
+ compatible = "renesas,r8a7790-usb-dmac", "renesas,usb-dmac";
reg = <0 0xe65a0000 0 0x100>;
interrupts = <0 109 IRQ_TYPE_LEVEL_HIGH
0 109 IRQ_TYPE_LEVEL_HIGH>;
diff --git a/Documentation/devicetree/bindings/dma/stm32-dma.txt b/Documentation/devicetree/bindings/dma/stm32-dma.txt
new file mode 100644
index 000000000000..70cd13f1588a
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/stm32-dma.txt
@@ -0,0 +1,82 @@
+* STMicroelectronics STM32 DMA controller
+
+The STM32 DMA is a general-purpose direct memory access controller capable of
+supporting 8 independent DMA channels. Each channel can have up to 8 requests.
+
+Required properties:
+- compatible: Should be "st,stm32-dma"
+- reg: Should contain DMA registers location and length. This should include
+ all of the per-channel registers.
+- interrupts: Should contain all of the per-channel DMA interrupts in
+ ascending order with respect to the DMA channel index.
+- clocks: Should contain the input clock of the DMA instance.
+- #dma-cells : Must be <4>. See DMA client paragraph for more details.
+
+Optional properties:
+- resets: Reference to a reset controller asserting the DMA controller
+- st,mem2mem: boolean; if defined, it indicates that the controller supports
+ memory-to-memory transfer
+
+Example:
+
+ dma2: dma-controller@40026400 {
+ compatible = "st,stm32-dma";
+ reg = <0x40026400 0x400>;
+ interrupts = <56>,
+ <57>,
+ <58>,
+ <59>,
+ <60>,
+ <68>,
+ <69>,
+ <70>;
+ clocks = <&clk_hclk>;
+ #dma-cells = <4>;
+ st,mem2mem;
+ resets = <&rcc 150>;
+ };
+
+* DMA client
+
+DMA clients connected to the STM32 DMA controller must use the format
+described in the dma.txt file, using a five-cell specifier for each
+channel: a phandle plus four integer cells.
+The four cells in order are:
+
+1. The channel id
+2. The request line number
+3. A 32bit mask specifying the DMA channel configuration which are device
+ dependent:
+ -bit 9: Peripheral Increment Address
+ 0x0: no address increment between transfers
+ 0x1: increment address between transfers
+ -bit 10: Memory Increment Address
+ 0x0: no address increment between transfers
+ 0x1: increment address between transfers
+ -bit 15: Peripheral Increment Offset Size
+ 0x0: offset size is linked to the peripheral bus width
+ 0x1: offset size is fixed to 4 (32-bit alignment)
+ -bit 16-17: Priority level
+ 0x0: low
+ 0x1: medium
+ 0x2: high
+ 0x3: very high
+5. A 32bit mask specifying the DMA FIFO threshold configuration which are device
+ dependent:
+ -bit 0-1: Fifo threshold
+ 0x0: 1/4 full FIFO
+ 0x1: 1/2 full FIFO
+ 0x2: 3/4 full FIFO
+ 0x3: full FIFO
+
+Example:
+
+ usart1: serial@40011000 {
+ compatible = "st,stm32-usart", "st,stm32-uart";
+ reg = <0x40011000 0x400>;
+ interrupts = <37>;
+ clocks = <&clk_pclk2>;
+ dmas = <&dma2 2 4 0x10400 0x3>,
+ <&dma2 7 5 0x10200 0x3>;
+ dma-names = "rx", "tx";
+ };
diff --git a/Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt b/Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt
index b152a75dceae..aead5869a28d 100644
--- a/Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt
+++ b/Documentation/devicetree/bindings/dma/ti-dma-crossbar.txt
@@ -14,6 +14,10 @@ The DMA controller node need to have the following poroperties:
Optional properties:
- ti,dma-safe-map: Safe routing value for unused request lines
+- ti,reserved-dma-request-ranges: DMA request ranges which should not be used
+ when mapping xbar input to DMA request, they are either
+ allocated to be used by for example the DSP or they are used as
+ memcpy channels in eDMA.
Notes:
When requesting channel via ti,dra7-dma-crossbar, the DMA clinet must request
@@ -46,6 +50,8 @@ sdma_xbar: dma-router@4a002b78 {
#dma-cells = <1>;
dma-requests = <205>;
ti,dma-safe-map = <0>;
+ /* Protect the sDMA request ranges: 10-14 and 100-126 */
+ ti,reserved-dma-request-ranges = <10 5>, <100 27>;
dma-masters = <&sdma>;
};
diff --git a/Documentation/dmaengine/client.txt b/Documentation/dmaengine/client.txt
index 11fb87ff6cd0..9e33189745f0 100644
--- a/Documentation/dmaengine/client.txt
+++ b/Documentation/dmaengine/client.txt
@@ -22,25 +22,14 @@ The slave DMA usage consists of following steps:
Channel allocation is slightly different in the slave DMA context,
client drivers typically need a channel from a particular DMA
controller only and even in some cases a specific channel is desired.
- To request a channel dma_request_channel() API is used.
+ To request a channel dma_request_chan() API is used.
Interface:
- struct dma_chan *dma_request_channel(dma_cap_mask_t mask,
- dma_filter_fn filter_fn,
- void *filter_param);
- where dma_filter_fn is defined as:
- typedef bool (*dma_filter_fn)(struct dma_chan *chan, void *filter_param);
+ struct dma_chan *dma_request_chan(struct device *dev, const char *name);
- The 'filter_fn' parameter is optional, but highly recommended for
- slave and cyclic channels as they typically need to obtain a specific
- DMA channel.
-
- When the optional 'filter_fn' parameter is NULL, dma_request_channel()
- simply returns the first channel that satisfies the capability mask.
-
- Otherwise, the 'filter_fn' routine will be called once for each free
- channel which has a capability in 'mask'. 'filter_fn' is expected to
- return 'true' when the desired DMA channel is found.
+ Which will find and return the 'name' DMA channel associated with the 'dev'
+ device. The association is done via DT, ACPI or board file based
+ dma_slave_map matching table.
A channel allocated via this interface is exclusive to the caller,
until dma_release_channel() is called.
@@ -128,7 +117,7 @@ The slave DMA usage consists of following steps:
transaction.
For cyclic DMA, a callback function may wish to terminate the
- DMA via dmaengine_terminate_all().
+ DMA via dmaengine_terminate_async().
Therefore, it is important that DMA engine drivers drop any
locks before calling the callback function which may cause a
@@ -166,12 +155,29 @@ The slave DMA usage consists of following steps:
Further APIs:
-1. int dmaengine_terminate_all(struct dma_chan *chan)
+1. int dmaengine_terminate_sync(struct dma_chan *chan)
+ int dmaengine_terminate_async(struct dma_chan *chan)
+ int dmaengine_terminate_all(struct dma_chan *chan) /* DEPRECATED */
This causes all activity for the DMA channel to be stopped, and may
discard data in the DMA FIFO which hasn't been fully transferred.
No callback functions will be called for any incomplete transfers.
+ Two variants of this function are available.
+
+ dmaengine_terminate_async() might not wait until the DMA has been fully
+ stopped or until any running complete callbacks have finished. But it is
+ possible to call dmaengine_terminate_async() from atomic context or from
+ within a complete callback. dmaengine_synchronize() must be called before it
+ is safe to free the memory accessed by the DMA transfer or free resources
+ accessed from within the complete callback.
+
+ dmaengine_terminate_sync() will wait for the transfer and any running
+ complete callbacks to finish before it returns. But the function must not be
+ called from atomic context or from within a complete callback.
+
+ dmaengine_terminate_all() is deprecated and should not be used in new code.
+
2. int dmaengine_pause(struct dma_chan *chan)
This pauses activity on the DMA channel without data loss.
@@ -197,3 +203,20 @@ Further APIs:
a running DMA channel. It is recommended that DMA engine users
pause or stop (via dmaengine_terminate_all()) the channel before
using this API.
+
+5. void dmaengine_synchronize(struct dma_chan *chan)
+
+ Synchronize the termination of the DMA channel to the current context.
+
+ This function should be used after dmaengine_terminate_async() to synchronize
+ the termination of the DMA channel to the current context. The function will
+ wait for the transfer and any running complete callbacks to finish before it
+ returns.
+
+ If dmaengine_terminate_async() is used to stop the DMA channel this function
+ must be called before it is safe to free memory accessed by previously
+ submitted descriptors or to free any resources accessed within the complete
+ callback of previously submitted descriptors.
+
+ The behavior of this function is undefined if dma_async_issue_pending() has
+ been called between dmaengine_terminate_async() and this function.
diff --git a/Documentation/dmaengine/provider.txt b/Documentation/dmaengine/provider.txt
index 67d4ce4df109..122b7f4876bb 100644
--- a/Documentation/dmaengine/provider.txt
+++ b/Documentation/dmaengine/provider.txt
@@ -327,8 +327,24 @@ supported.
* 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
+ - For aborted transfers the complete callback should not be called
+ - Can be called from atomic context or from within a complete
+ callback of a descriptor. Must not sleep. Drivers must be able
+ to handle this correctly.
+ - Termination may be asynchronous. The driver does not have to
+ wait until the currently active transfer has completely stopped.
+ See device_synchronize.
+
+ * device_synchronize
+ - Must synchronize the termination of a channel to the current
+ context.
+ - Must make sure that memory for previously submitted
+ descriptors is no longer accessed by the DMA controller.
+ - Must make sure that all complete callbacks for previously
+ submitted descriptors have finished running and none are
+ scheduled to run.
+ - May sleep.
+
Misc notes (stuff that should be documented, but don't really know
where to put them)