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Commit 92ea637e authored by Santosh Shilimkar's avatar Santosh Shilimkar
Browse files

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: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarSantosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: default avatarGrygorii Strashko <grygorii.strashko@ti.com>
parent 18308c94

drivers/of/address.c

+23 −0
Original line number Diff line number Diff line
@@ -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

include/linux/of_address.h

+6 −0
Original line number Diff line number Diff line
@@ -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