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docs: firmware-guide: ACPI: Replace dma_request_slave_channel() with dma_request_chan()

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dma_request_chan() is the preferred API to request slave channels.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Peter Ujfalusi 2019-12-17 12:48:56 +02:00 committed by Rafael J. Wysocki
parent d1eef1c619
commit 0435bcd9e1
1 changed files with 8 additions and 8 deletions
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16
Documentation/firmware-guide/acpi/enumeration.rst
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@ -71,8 +71,8 @@ DMA support
DMA controllers enumerated via ACPI should be registered in the system to DMA controllers enumerated via ACPI should be registered in the system to
provide generic access to their resources. For example, a driver that would provide generic access to their resources. For example, a driver that would
like to be accessible to slave devices via generic API call like to be accessible to slave devices via generic API call
dma_request_slave_channel() must register itself at the end of the probe dma_request_chan() must register itself at the end of the probe function like
function like this:: this::
err = devm_acpi_dma_controller_register(dev, xlate_func, dw); err = devm_acpi_dma_controller_register(dev, xlate_func, dw);
/* Handle the error if it's not a case of !CONFIG_ACPI */ /* Handle the error if it's not a case of !CONFIG_ACPI */
@ -112,15 +112,15 @@ could look like::
} }
#endif #endif
dma_request_slave_channel() will call xlate_func() for each registered DMA dma_request_chan() will call xlate_func() for each registered DMA controller.
controller. In the xlate function the proper channel must be chosen based on In the xlate function the proper channel must be chosen based on
information in struct acpi_dma_spec and the properties of the controller information in struct acpi_dma_spec and the properties of the controller
provided by struct acpi_dma. provided by struct acpi_dma.
Clients must call dma_request_slave_channel() with the string parameter that Clients must call dma_request_chan() with the string parameter that corresponds
corresponds to a specific FixedDMA resource. By default "tx" means the first to a specific FixedDMA resource. By default "tx" means the first entry of the
entry of the FixedDMA resource array, "rx" means the second entry. The table FixedDMA resource array, "rx" means the second entry. The table below shows a
below shows a layout:: layout::
Device (I2C0) Device (I2C0)
{ {