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

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
......@@ -808,3 +808,26 @@ int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *siz
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
......@@ -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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