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authorSantosh Shilimkar <santosh.shilimkar@ti.com>2014-04-24 11:30:03 -0400
committerSantosh Shilimkar <santosh.shilimkar@ti.com>2014-05-05 18:11:13 -0400
commit92ea637edea36e58236e3124f199161da6f5c5de (patch)
tree3d448091313a8f872a8e6bb7498c447350d801b8
parent18308c94723e162ed121942335bc186e66820a7a (diff)
downloadop-kernel-dev-92ea637edea36e58236e3124f199161da6f5c5de.zip
op-kernel-dev-92ea637edea36e58236e3124f199161da6f5c5de.tar.gz
of: introduce of_dma_is_coherent() helper
The of_dma_is_coherent() helper parses the given DT device node to see if the "dma-coherent" property is supported and returns true or false accordingly. If the arch is always coherent or always noncoherent, then the default DMA ops has to be specified accordingly. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Olof Johansson <olof@lixom.net> Cc: Grant Likely <grant.likely@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
-rw-r--r--drivers/of/address.c23
-rw-r--r--include/linux/of_address.h6
2 files changed, 29 insertions, 0 deletions
diff --git a/drivers/of/address.c b/drivers/of/address.c
index c54baee..d244b28 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -808,3 +808,26 @@ out:
return ret;
}
EXPORT_SYMBOL_GPL(of_dma_get_range);
+
+/**
+ * of_dma_is_coherent - Check if device is coherent
+ * @np: device node
+ *
+ * It returns true if "dma-coherent" property was found
+ * for this device in DT.
+ */
+bool of_dma_is_coherent(struct device_node *np)
+{
+ struct device_node *node = of_node_get(np);
+
+ while (node) {
+ if (of_property_read_bool(node, "dma-coherent")) {
+ of_node_put(node);
+ return true;
+ }
+ node = of_get_next_parent(node);
+ }
+ of_node_put(node);
+ return false;
+}
+EXPORT_SYMBOL_GPL(of_dma_is_coherent); \ No newline at end of file
diff --git a/include/linux/of_address.h b/include/linux/of_address.h
index 4d7b325..839a352 100644
--- a/include/linux/of_address.h
+++ b/include/linux/of_address.h
@@ -65,6 +65,7 @@ extern struct of_pci_range *of_pci_range_parser_one(
struct of_pci_range *range);
extern int of_dma_get_range(struct device_node *np, u64 *dma_addr,
u64 *paddr, u64 *size);
+extern bool of_dma_is_coherent(struct device_node *np);
#else /* CONFIG_OF_ADDRESS */
static inline struct device_node *of_find_matching_node_by_address(
struct device_node *from,
@@ -98,6 +99,11 @@ static inline int of_dma_get_range(struct device_node *np, u64 *dma_addr,
{
return -ENODEV;
}
+
+static inline bool of_dma_is_coherent(struct device_node *np)
+{
+ return false;
+}
#endif /* CONFIG_OF_ADDRESS */
#ifdef CONFIG_OF
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