diff options
| author | Suthikulpanit, Suravee <Suravee.Suthikulpanit@amd.com> | 2015-10-29 01:50:49 +0300 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2015-11-07 03:29:22 +0300 |
| commit | e5e558644bbb23cad03c586703331b8bcd9e0e6c (patch) | |
| tree | 8e183e85861b37394bfa6a64b2352848325e0b6b /drivers/base | |
| parent | b84f196d963c3159329f72ca1913b08679004a43 (diff) | |
| download | linux-e5e558644bbb23cad03c586703331b8bcd9e0e6c.tar.xz | |
device property: Adding DMA Attribute APIs for Generic Devices
The function device_dma_is_coherent() does not sufficiently
communicate device DMA attributes. Instead, this patch introduces
device_get_dma_attr(), which returns enum dev_dma_attr.
It replaces the acpi_check_dma(), which will be removed in
subsequent patch.
This also provides a convenient function, device_dma_supported(),
to check DMA support of the specified device.
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/property.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/drivers/base/property.c b/drivers/base/property.c index de40623bbd8a..05d57a2afa05 100644 --- a/drivers/base/property.c +++ b/drivers/base/property.c @@ -611,6 +611,35 @@ bool device_dma_is_coherent(struct device *dev) } EXPORT_SYMBOL_GPL(device_dma_is_coherent); +bool device_dma_supported(struct device *dev) +{ + /* For DT, this is always supported. + * For ACPI, this depends on CCA, which + * is determined by the acpi_dma_supported(). + */ + if (IS_ENABLED(CONFIG_OF) && dev->of_node) + return true; + + return acpi_dma_supported(ACPI_COMPANION(dev)); +} +EXPORT_SYMBOL_GPL(device_dma_supported); + +enum dev_dma_attr device_get_dma_attr(struct device *dev) +{ + enum dev_dma_attr attr = DEV_DMA_NOT_SUPPORTED; + + if (IS_ENABLED(CONFIG_OF) && dev->of_node) { + if (of_dma_is_coherent(dev->of_node)) + attr = DEV_DMA_COHERENT; + else + attr = DEV_DMA_NON_COHERENT; + } else + attr = acpi_get_dma_attr(ACPI_COMPANION(dev)); + + return attr; +} +EXPORT_SYMBOL_GPL(device_get_dma_attr); + /** * device_get_phy_mode - Get phy mode for given device * @dev: Pointer to the given device |