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path: root/drivers/dma/acpi-dma.c
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* acpi-dma: convert to return error code when asked for channelAndy Shevchenko2014-02-111-7/+8
| | | | | | | | | | | Currently acpi_dma_request_slave_chan_by_index() and acpi_dma_request_slave_chan_by_name() return only requested channel or NULL. This patch converts them to return appropriate error code instead of NULL in case of unsuccessfull request. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
* acpi-dma: use devm_release() instead of devm_destroy()Andy Shevchenko2014-02-111-1/+1
| | | | | | | | | Since devm_destroy() doesn't call release function we have to use devm_release() instead. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
* acpi-dma: align documentation with kernel-doc formatAndy Shevchenko2014-01-261-12/+24
| | | | | | | | | It mostly fixes the "RETURN" sections in the resulting manual page. There is no functional change. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
* acpi-dma: remove ugly conversionAndy Shevchenko2013-08-251-3/+1
| | | | | | | | | | | In case of big endian CPU we have to convert either all fields in the structure or leave this job to ACPICA. The second choice seems the best. So, let's remove the ugly conversion that is not fully comprehensive anyway. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
* acpi-dma: fix sparse warningAndy Shevchenko2013-08-051-1/+1
| | | | | | | | | | | | | | This patch fixes sparse warning: drivers/dma/acpi-dma.c:76:21: sparse: cast to restricted __le32 Since everything in all ACPI tables is little-endian, by definition, the used types in practice are uXX. Thus, we have to enforce __leXX if we want to convert them to CPU order. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
* dma: acpi-dma: parse CSRT to extract additional resourcesAndy Shevchenko2013-05-141-3/+169
| | | | | | | | | | Since we have CSRT only to get additional DMA controller resources, let's get rid of drivers/acpi/csrt.c and move its logic inside ACPI DMA helpers code. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
* dma: acpi-dma: introduce ACPI DMA helpersAndy Shevchenko2013-04-151-0/+279
There is a new generic API to get a DMA channel for a slave device (commit 9a6cecc8 "dmaengine: add helper function to request a slave DMA channel"). In similar fashion to the DT case (commit aa3da644 "of: Add generic device tree DMA helpers") we introduce helpers to the DMAC drivers which are enumerated by ACPI. The proposed extension provides the following API calls: acpi_dma_controller_register(), devm_acpi_dma_controller_register() acpi_dma_controller_free(), devm_acpi_dma_controller_free() acpi_dma_simple_xlate() acpi_dma_request_slave_chan_by_index() acpi_dma_request_slave_chan_by_name() The first two should be used, for example, at probe() and remove() of the corresponding DMAC driver. At the register stage the DMAC driver supplies a custom xlate() function to translate a struct dma_spec into struct dma_chan. Accordingly to the ACPI Fixed DMA resource specification the only two pieces of information the slave device has are the channel id and the request line (slave id). Those two are represented by struct dma_spec. The acpi_dma_request_slave_chan_by_index() provides access to the specifix FixedDMA resource by its index. Whereas dma_request_slave_channel() takes a string parameter to identify the DMA resources required by the slave device. To make a slave device driver work with both DeviceTree and ACPI enumeration a simple convention is established: "tx" corresponds to the index 0 and "rx" to the index 1. In case of robust configuration the slave device driver unfortunately needs to call acpi_dma_request_slave_chan_by_index() directly. Additionally the patch provides "managed" version of the register/free pair i.e. devm_acpi_dma_controller_register() and devm_acpi_dma_controller_free(). Usually, the driver uses only devm_acpi_dma_controller_register(). Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
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