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authorSantosh Shilimkar <santosh.shilimkar@ti.com>2014-04-24 19:30:03 +0400
committerSantosh Shilimkar <santosh.shilimkar@ti.com>2014-05-06 02:11:13 +0400
commit92ea637edea36e58236e3124f199161da6f5c5de (patch)
tree3d448091313a8f872a8e6bb7498c447350d801b8 /drivers/of
parent18308c94723e162ed121942335bc186e66820a7a (diff)
downloadlinux-92ea637edea36e58236e3124f199161da6f5c5de.tar.xz
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>
Diffstat (limited to 'drivers/of')
-rw-r--r--drivers/of/address.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/of/address.c b/drivers/of/address.c
index c54baee87d93..d244b2859aac 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