From 1faab1f2e3be3a10197840648d03a31fd0a29e93 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Mon, 17 Nov 2014 14:42:55 +0100 Subject: Documentation: dmaengine: Update the documentation Now that we have splitted device_control and removed device_slave_caps in favor of a few dma_device variables, update the documentation accordingly. Signed-off-by: Maxime Ripard Signed-off-by: Vinod Koul --- Documentation/dmaengine/provider.txt | 93 ++++++++++++++++++++---------------- 1 file changed, 51 insertions(+), 42 deletions(-) (limited to 'Documentation') diff --git a/Documentation/dmaengine/provider.txt b/Documentation/dmaengine/provider.txt index 766658ccf235..2c391cfe37eb 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 +299,32 @@ 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 + + * 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) -- cgit v1.2.3 From 6269591b989878992be443f77caa9ca4738dfaaf Mon Sep 17 00:00:00 2001 From: Vinod Koul Date: Sun, 7 Dec 2014 23:18:01 +0530 Subject: Documentation: dmaengine: clarify dma_slave_config expectations dma_slave_config is expected to be set for slave operations Only, not for memcpy ones Signed-off-by: Vinod Koul --- Documentation/dmaengine/provider.txt | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'Documentation') diff --git a/Documentation/dmaengine/provider.txt b/Documentation/dmaengine/provider.txt index 2c391cfe37eb..05d2280190f1 100644 --- a/Documentation/dmaengine/provider.txt +++ b/Documentation/dmaengine/provider.txt @@ -310,6 +310,10 @@ supported. - 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 -- cgit v1.2.3 From c4d7635280f24cfa8c3ef34c122600d148749030 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Sun, 6 Jul 2014 16:07:20 +0200 Subject: dmaengine: rcar-dmac: Remove duplicate sentence from DT bindings DT bindings are complex enough without expressing the same information twice in a slightly different way. Remove the duplicate. Reported-by: Geert Uytterhoeven Signed-off-by: Laurent Pinchart Tested-by: Kuninori Morimoto Tested-by: Wolfram Sang --- Documentation/devicetree/bindings/dma/renesas,rcar-dmac.txt | 3 --- 1 file changed, 3 deletions(-) (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.txt b/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.txt index df0f48bcf75a..5fb13ada29a9 100644 --- a/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.txt +++ b/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.txt @@ -5,9 +5,6 @@ controller instances named DMAC capable of serving multiple clients. Channels can be dedicated to specific clients or shared between a large number of clients. -DMA clients are connected to the DMAC ports referenced by an 8-bit identifier -called MID/RID. - Each DMA client is connected to one dedicated port of the DMAC, identified by an 8-bit port number called the MID/RID. A DMA controller can thus serve up to 256 clients in total. When the number of hardware channels is lower than the -- cgit v1.2.3 From 91d457dd50ea2ea35fe5b6e069169491ad45bffb Mon Sep 17 00:00:00 2001 From: Andrew Bresticker Date: Thu, 11 Dec 2014 14:59:16 -0800 Subject: dmaengine: Add binding document for IMG MDC Add a binding document for the IMG Multi-threaded DMA Controller (MDC) present on the MIPS-based Pistachio and other IMG SoCs. Signed-off-by: Andrew Bresticker Acked-by: Arnd Bergmann Signed-off-by: Vinod Koul --- .../devicetree/bindings/dma/img-mdc-dma.txt | 57 ++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 Documentation/devicetree/bindings/dma/img-mdc-dma.txt (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/dma/img-mdc-dma.txt b/Documentation/devicetree/bindings/dma/img-mdc-dma.txt new file mode 100644 index 000000000000..28c1341db346 --- /dev/null +++ b/Documentation/devicetree/bindings/dma/img-mdc-dma.txt @@ -0,0 +1,57 @@ +* IMG Multi-threaded DMA Controller (MDC) + +Required properties: +- compatible: Must be "img,pistachio-mdc-dma". +- reg: Must contain the base address and length of the MDC registers. +- interrupts: Must contain all the per-channel DMA interrupts. +- clocks: Must contain an entry for each entry in clock-names. + See ../clock/clock-bindings.txt for details. +- clock-names: Must include the following entries: + - sys: MDC system interface clock. +- img,cr-periph: Must contain a phandle to the peripheral control syscon + node which contains the DMA request to channel mapping registers. +- img,max-burst-multiplier: Must be the maximum supported burst size multiplier. + The maximum burst size is this value multiplied by the hardware-reported bus + width. +- #dma-cells: Must be 3: + - The first cell is the peripheral's DMA request line. + - The second cell is a bitmap specifying to which channels the DMA request + line may be mapped (i.e. bit N set indicates channel N is usable). + - The third cell is the thread ID to be used by the channel. + +Optional properties: +- dma-channels: Number of supported DMA channels, up to 32. If not specified + the number reported by the hardware is used. + +Example: + +mdc: dma-controller@18143000 { + compatible = "img,pistachio-mdc-dma"; + reg = <0x18143000 0x1000>; + interrupts = , + , + , + , + , + , + , + , + , + , + , + ; + clocks = <&system_clk>; + clock-names = "sys"; + + img,max-burst-multiplier = <16>; + img,cr-periph = <&cr_periph>; + + #dma-cells = <3>; +}; + +spi@18100f00 { + ... + dmas = <&mdc 9 0xffffffff 0>, <&mdc 10 0xffffffff 0>; + dma-names = "tx", "rx"; + ... +}; -- cgit v1.2.3 From d8ded50f8b26a224df48f9f93e49440c6a39b77f Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Tue, 13 Jan 2015 19:08:14 +0200 Subject: dmaengine: dw: define DW_DMA_MAX_NR_MASTERS Instead of using magic number in the code the patch provides DW_DMA_MAX_NR_MASTERS constant. While here, restrict the reading of data width array by amount of the actual number of AHB masters. Signed-off-by: Andy Shevchenko Signed-off-by: Vinod Koul --- Documentation/devicetree/bindings/dma/snps-dma.txt | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/dma/snps-dma.txt b/Documentation/devicetree/bindings/dma/snps-dma.txt index d58675ea1abf..c261598164a7 100644 --- a/Documentation/devicetree/bindings/dma/snps-dma.txt +++ b/Documentation/devicetree/bindings/dma/snps-dma.txt @@ -38,7 +38,7 @@ Example: chan_allocation_order = <1>; chan_priority = <1>; block_size = <0xfff>; - data_width = <3 3 0 0>; + data_width = <3 3>; }; DMA clients connected to the Designware DMA controller must use the format -- cgit v1.2.3