Andy Shevchenko 1b2e98bc1e dma: acpi-dma: introduce ACPI DMA helpers ... 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>		2013-04-15 22:04:10 +05:30
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apei	Update documentation for parameter *notrigger* in einj.txt	2012-03-30 03:30:19 -04:00
debug.txt	ACPI: update debug parameter documentation	2008-11-07 21:45:29 -05:00
dsdt-override.txt	ACPI: Remove ACPI_CUSTOM_DSDT_INITRD option	2008-03-15 11:58:04 -07:00
enumeration.txt	dma: acpi-dma: introduce ACPI DMA helpers	2013-04-15 22:04:10 +05:30
initrd_table_override.txt	ACPI: Document ACPI table overriding via initrd	2012-09-30 18:03:41 -07:00
method-customizing.txt	ACPI: Split out custom_method functionality into an own driver	2011-05-29 01:50:40 -04:00
method-tracing.txt	ACPI: document method tracing hooks	2007-11-19 12:25:56 -05:00
scan_handlers.txt	ACPI / scan: Introduce struct acpi_scan_handler	2013-01-30 14:27:29 +01:00