kernel/linux.git/drivers/dma/dw, branch v5.15.7

dmaengine: dw: Simplify DT property parser

2021-08-06T13:48:59+00:00

Since we converted internal data types to match DT, there is no need to have an intermediate conversion layer, hence drop a few conditionals and for loops for good. Signed-off-by: Andy Shevchenko Reviewed-by: Serge Semin Tested-by: Serge Semin Link: https://lore.kernel.org/r/20210802184355.49879-3-andriy.shevchenko@linux.intel.com Signed-off-by: Vinod Koul

dmaengine: dw: Remove error message from DT parsing code

2021-08-06T13:47:46+00:00

Users are a bit frightened of the harmless message that tells that DT is missed on ACPI-based platforms. Remove it for good, it will simplify the future conversion to fwnode and device property APIs. Fixes: a9ddb575d6d6 ("dmaengine: dw_dmac: Enhance device tree support") Depends-on: f5e84eae7956 ("dmaengine: dw: platform: Split OF helpers to separate module") BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=199379 Signed-off-by: Andy Shevchenko Reviewed-by: Serge Semin Tested-by: Serge Semin Link: https://lore.kernel.org/r/20210802184355.49879-1-andriy.shevchenko@linux.intel.com Signed-off-by: Vinod Koul

dmaengine: dw: Program xBAR hardware for Elkhart Lake

2021-07-14T04:46:30+00:00

Intel Elkhart Lake PSE DMA implementation is integrated with crossbar IP in order to serve more hardware than there are DMA request lines available. Due to this, program xBAR hardware to make flexible support of PSE peripheral. The Device-to-Device has not been tested and it's not supported by DMA Engine, but it's left in the code for the sake of documenting hardware features. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20210712113940.42753-1-andriy.shevchenko@linux.intel.com Signed-off-by: Vinod Koul

dmaengine: dw: Make it dependent to HAS_IOMEM

2021-04-12T09:24:45+00:00

Some architectures do not provide devm_*() APIs. Hence make the driver dependent on HAVE_IOMEM. Fixes: dbde5c2934d1 ("dw_dmac: use devm_* functions to simplify code") Reported-by: kernel test robot Signed-off-by: Andy Shevchenko Acked-by: Viresh Kumar Link: https://lore.kernel.org/r/20210324141757.24710-1-andriy.shevchenko@linux.intel.com Signed-off-by: Vinod Koul

dmaengine dw: Revert "dmaengine: dw: Enable runtime PM"

2021-02-08T12:06:12+00:00

This reverts commit 842067940a3e3fc008a60fee388e000219b32632. For some solutions e.g. sound/soc/intel/catpt, DW DMA is part of a compound device (in that very example, domains: ADSP, SSP0, SSP1, DMA0 and DMA1 are part of a single entity) rather than being a standalone one. Driver for said device may enlist DMA to transfer data during suspend or resume sequences. Manipulating RPM explicitly in dw's DMA request and release channel functions causes suspend() to also invoke resume() for the exact same device. Similar situation occurs for resume() sequence. Effectively renders device dysfunctional after first suspend() attempt. Revert the change to address the problem. Fixes: 842067940a3e ("dmaengine: dw: Enable runtime PM") Cc: Andy Shevchenko Signed-off-by: Cezary Rojewski Acked-by: Andy Shevchenko Link: https://lore.kernel.org/r/20210203191924.15706-1-cezary.rojewski@intel.com Signed-off-by: Vinod Koul

dmaengine: dw: Enable runtime PM

2020-11-09T11:49:20+00:00

When consumer requests channel power on the DMA controller device and otherwise on the freeing channel resources. Note, in some cases consumer acquires channel at the ->probe() stage and releases it at the ->remove() stage. It will mean that DMA controller device will be powered during all this time if there is no assist from hardware to idle it. The above mentioned cases should be investigated separately and individually. Signed-off-by: Andy Shevchenko Acked-by: Viresh Kumar Link: https://lore.kernel.org/r/20201103183938.64752-1-andriy.shevchenko@linux.intel.com Signed-off-by: Vinod Koul

dmaengine: dw: convert tasklets to use new tasklet_setup() API

2020-09-18T06:48:11+00:00

In preparation for unconditionally passing the struct tasklet_struct pointer to all tasklet callbacks, switch to using the new tasklet_setup() and from_tasklet() to pass the tasklet pointer explicitly. Signed-off-by: Romain Perier Signed-off-by: Allen Pais Link: https://lore.kernel.org/r/20200831103542.305571-6-allen.lkml@gmail.com Signed-off-by: Vinod Koul

dmaengine: dw: Add DMA-channels mask cell support

2020-08-17T06:28:31+00:00

DW DMA IP-core provides a way to synthesize the DMA controller with channels having different parameters like maximum burst-length, multi-block support, maximum data width, etc. Those parameters both explicitly and implicitly affect the channels performance. Since DMA slave devices might be very demanding to the DMA performance, let's provide a functionality for the slaves to be assigned with DW DMA channels, which performance according to the platform engineer fulfill their requirements. After this patch is applied it can be done by passing the mask of suitable DMA-channels either directly in the dw_dma_slave structure instance or as a fifth cell of the DMA DT-property. If mask is zero or not provided, then there is no limitation on the channels allocation. For instance Baikal-T1 SoC is equipped with a DW DMAC engine, which first two channels are synthesized with max burst length of 16, while the rest of the channels have been created with max-burst-len=4. It would seem that the first two channels must be faster than the others and should be more preferable for the time-critical DMA slave devices. In practice it turned out that the situation is quite the opposite. The channels with max-burst-len=4 demonstrated a better performance than the channels with max-burst-len=16 even when they both had been initialized with the same settings. The performance drop of the first two DMA-channels made them unsuitable for the DW APB SSI slave device. No matter what settings they are configured with, full-duplex SPI transfers occasionally experience the Rx FIFO overflow. It means that the DMA-engine doesn't keep up with incoming data pace even though the SPI-bus is enabled with speed of 25MHz while the DW DMA controller is clocked with 50MHz signal. There is no such problem has been noticed for the channels synthesized with max-burst-len=4. Signed-off-by: Serge Semin Link: https://lore.kernel.org/r/20200731200826.9292-6-Sergey.Semin@baikalelectronics.ru Signed-off-by: Vinod Koul

dmaengine: dw: Ignore burst setting for memory peripherals

2020-08-17T06:28:31+00:00

According to the DW DMA controller Databook 2.18b (page 40 "3.5 Memory Peripherals") memory peripherals don't have handshaking interface connected to the controller, therefore they can never be a flow controller. Since the CTLx.SRC_MSIZE and CTLx.DEST_MSIZE are properties valid only for peripherals with a handshaking interface, we can freely zero these fields out if the memory peripheral is selected to be the source or the destination of the DMA transfers. Note according to the databook, length of burst transfers to memory is always equal to the number of data items available in a channel FIFO or data items required to complete the block transfer, whichever is smaller; length of burst transfers from memory is always equal to the space available in a channel FIFO or number of data items required to complete the block transfer, whichever is smaller. Signed-off-by: Serge Semin Link: https://lore.kernel.org/r/20200731200826.9292-5-Sergey.Semin@baikalelectronics.ru Signed-off-by: Vinod Koul

dmaengine: dw: Discard dlen from the dev-to-mem xfer width calculation

2020-08-17T06:28:31+00:00

Indeed in case of the DMA_DEV_TO_MEM DMA transfers it's enough to take the destination memory address and the destination master data width into account to calculate the CTLx.DST_TR_WIDTH setting of the memory peripheral. According to the DW DMAC IP-core Databook 2.18b (page 66, Example 5) at the and of a DMA transfer when the DMA-channel internal FIFO is left with data less than for a single destination burst transaction, the destination peripheral will enter the Single Transaction Region where the DW DMA controller can complete a block transfer to the destination using single transactions (non-burst transaction of CTLx.DST_TR_WIDTH bytes). If there is no enough data in the DMA-channel internal FIFO for even a single non-burst transaction of CTLx.DST_TR_WIDTH bytes, then the channel enters "FIFO flush mode". That mode is activated to empty the FIFO and flush the leftovers out to the memory peripheral. The flushing procedure is simple. The data is sent to the memory by means of a set of single transaction of CTLx.SRC_TR_WIDTH bytes. To sum up it's redundant to use the LLPs length to find out the CTLx.DST_TR_WIDTH parameter value, since each DMA transfer will be completed with the CTLx.SRC_TR_WIDTH bytes transaction if it is required. We suggest to remove the LLP entry length from the statement which calculates the memory peripheral DMA transaction width since it's redundant due to the feature described above. By doing so we'll improve the memory bus utilization and speed up the DMA-channel performance for DMA_DEV_TO_MEM DMA-transfers. Signed-off-by: Serge Semin Acked-by: Andy Shevchenko Link: https://lore.kernel.org/r/20200731200826.9292-4-Sergey.Semin@baikalelectronics.ru Signed-off-by: Vinod Koul