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path: root/drivers/dma/idma64.c
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2016-02-15dmaengine: idma64: clear LLP_[SD]_EN bits in last descriptorAndy Shevchenko
The datasheet requires that the user must clear LLP_[SD]_EN bits whenever LLP.LOC is zero, i.e. in the last descriptor of a multi-block chain. Make the driver do this. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-05dmaengine: idma64: use local variable to index descriptorAndy Shevchenko
Since a local variable contains the number of hardware desriptors at the beginning of idma64_desc_fill() we may use it to index the last descriptor as well. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-05dmaengine: idma64: convert idma64_hw_desc_fill() to return voidAndy Shevchenko
Explicitly show in idma64_desc_fill() how we link the hardware descriptors. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-05dmaengine: idma64: set maximum allowed segment size for DMAAndy Shevchenko
This tells, for example, IOMMU what the maximum size of a segment the DMA controller can send. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-05dmaengine: idma64: drop IRQ enable / disable in handlerAndy Shevchenko
There is no need to disable interrupts in the IRQ handler. The driver guarantess that at one time only one descriptor is active, besides the fact that each call to the same channel will be serialized in idma64_chan_irq() handler anyway. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-11-10Merge tag 'dmaengine-4.4-rc1' of git://git.infradead.org/users/vkoul/slave-dmaLinus Torvalds
Pull dmaengine updates from Vinod Koul: "This time we have a very typical update which is mostly fixes and updates to drivers and no new drivers. - the biggest change is coming from Peter for edma cleanup which even caused some last minute regression, things seem settled now - idma64 and dw updates - iotdma updates - module autoload fixes for various drivers - scatter gather support for hdmac" * tag 'dmaengine-4.4-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (77 commits) dmaengine: edma: Add dummy driver skeleton for edma3-tptc Revert "ARM: DTS: am33xx: Use the new DT bindings for the eDMA3" Revert "ARM: DTS: am437x: Use the new DT bindings for the eDMA3" dmaengine: dw: some Intel devices has no memcpy support dmaengine: dw: platform: provide platform data for Intel dmaengine: dw: don't override platform data with autocfg dmaengine: hdmac: Add scatter-gathered memset support dmaengine: hdmac: factorise memset descriptor allocation dmaengine: virt-dma: Fix kernel-doc annotations ARM: DTS: am437x: Use the new DT bindings for the eDMA3 ARM: DTS: am33xx: Use the new DT bindings for the eDMA3 dmaengine: edma: New device tree binding dmaengine: Kconfig: edma: Select TI_DMA_CROSSBAR in case of ARCH_OMAP dmaengine: ti-dma-crossbar: Add support for crossbar on AM33xx/AM43xx dmaengine: edma: Merge the of parsing functions dmaengine: edma: Do not allocate memory for edma_rsv_info in case of DT boot dmaengine: edma: Refactor the dma device and channel struct initialization dmaengine: edma: Get qDMA channel information from HW also dmaengine: edma: Merge map_dmach_to_queue into assign_channel_eventq dmaengine: edma: Correct PaRAM access function names (_parm_ to _param_) ...
2015-09-25dmaengine: idma64: make better performance on pause / resumeAndy Shevchenko
Accordingly to the documentation the CH_DRAIN bit enforses single bursts when channel is going to be suspended. This, in case when channel will be resumed, makes data to flow in non-optimal mode until DMA returns to full burst mode. The fix differentiates pause / resume cycle from pause / terminate and sets CH_DRAIN bit accordingly. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-09-25dmaengine: idma64: useless use of min_t()Andy Shevchenko
We use a pattern x = min_t(u32, <LOG2_CONSTANT>, __ffs(expr)); There is no need to use min_t() since we can replace it by x = __ffs(expr | <2^LOG2_CONST>); and moreover guarantee that argument of __ffs() will be not zero. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-09-25dmaengine: idma64: convert to __ffs()Andy Shevchenko
We replace __fls() by __ffs() since we have to find a *minimum* data width that satisfies both source and destination. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-09-25dmaengine: idma64: improve residue estimationAndy Shevchenko
The residue calculation may provide a wrong estimation when the transfer is started. There are possible scenarios we have to separate: 1) the transfer is not started yet; residue is equal to the total length; 2) the transfer is just started (first chunk is ongoing); residue is equal to the total length without already transfered bytes; 3) the transfer is ongoing and we already sent few chunks of data; residue is equal to the total length without fully transfered chunks and already sent bytes. Mistakenly the calculation in cases 2) and 3) was done in the similar way and the result is equal to -bytes that have been transfered, i.e. quite big since size_t type can't keep negative values. Rewrite the calculation algorithm to be one pass and have a correct result. Besides above in case user asks for a status of the active DMA descriptor without pausing an ongoing transfer the residue will be estimated based on the register value, though it's still racy. Since the transfer is active the value is continuously being changed. Here we have to read two registers at a time. To minimize an error make those reads close to each other. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-07-28dmaengine: add a driver for Intel integrated DMA 64-bitAndy Shevchenko
Intel integrated DMA (iDMA) 64-bit is a specific IP that is used as a part of LPSS devices such as HSUART or SPI. The iDMA IP is attached for private usage on each host controller independently. While it has similarities with Synopsys DesignWare DMA, the following distinctions doesn't allow to use the existing driver: - 64-bit mode with corresponding changes in Hardware Linked List data structure - many slight differences in the channel registers Moreover this driver is based on the DMA virtual channels framework that helps to make the driver cleaner and easy to understand. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>