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@xxxxxxx>
CC: Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>
---
drivers/base/property.c | 29 +++++++++++++++++++++++++++++
include/linux/property.h | 4 ++++
2 files changed, 33 insertions(+)
diff --git a/drivers/base/property.c b/drivers/base/property.c
index 2d75366..baac186 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -547,6 +547,35 @@ 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
diff --git a/include/linux/property.h b/include/linux/property.h
index 522c1bf..bde8de3 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -172,6 +172,10 @@ void device_add_property_set(struct device *dev, struct property_set *pset);
bool device_dma_is_coherent(struct device *dev);
+bool device_dma_supported(struct device *dev);
+
+enum dev_dma_attr device_get_dma_attr(struct device *dev);
+
int device_get_phy_mode(struct device *dev);
void *device_get_mac_address(struct device *dev, char *addr, int alen);
--
2.1.0
--
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