summaryrefslogtreecommitdiffstats
path: root/Documentation/acpi/enumeration.txt
Commit message (Collapse)AuthorAgeFilesLines
* dma: acpi-dma: introduce ACPI DMA helpersAndy Shevchenko2013-04-151-0/+77
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* ACPI / Documentation: refer to correct file for acpi_platform_device_ids[] tableMika Westerberg2013-02-131-2/+2
| | | | | | | | | When the ACPI platform device code was converted to the new ACPI scan handler facility, the the acpi_platform_device_ids[] was moved to drivers/acpi/acpi_platform.c. Update the documentation accordingly. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* Documentation: remove __dev* attributes.Greg Kroah-Hartman2013-01-031-1/+1
| | | | | | | | | | | | | | CONFIG_HOTPLUG is going away as an option. As a result, the __dev* markings need to be removed. This change removes the use of __devinit, __devexit_p, __devinitdata, __devinitconst, and __devexit from the kernel documentation. Based on patches originally written by Bill Pemberton, but redone by me in order to handle some of the coding style issues better, by hand. Cc: Bill Pemberton <wfp5p@virginia.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ACPI: add documentation about ACPI 5 enumerationMika Westerberg2012-12-071-0/+227
Add a document that describes how to take advantage of ACPI enumeration for buses like platform, I2C and SPI. In addition to that we document how to translate ACPI GpioIo and GpioInt resources to be useful in Linux device drivers. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
OpenPOWER on IntegriCloud