Re: [PATCH v3 3/7] of: introduce of_dma_is_coherent() helper

Rob Herring
2014-05-02T00:56:49Z

On Thu, Apr 24, 2014 at 10:30 AM, Santosh Shilimkar
<santosh.shilimkar@ti.com> wrote:
> 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: Rob Herring <robh+dt@kernel.org>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
> ---
> drivers/of/platform.c | 23 +++++++++++++++++++++++
> include/linux/of_platform.h | 6 ++++++

I thought I said this already, but this does not belong in these files
as the function does not deal with platform devices. Probably
address.c/of_address.h would be the best place.

Rob

> 2 files changed, 29 insertions(+)
>
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index 404d1da..48de98f 100644
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -485,4 +485,27 @@ int of_platform_populate(struct device_node *root,
> return rc;
> }
> EXPORT_SYMBOL_GPL(of_platform_populate);
> +
> +/**
> + * 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);
> #endif /* CONFIG_OF_ADDRESS */
> diff --git a/include/linux/of_platform.h b/include/linux/of_platform.h
> index 05cb4a9..b9a3cb2 100644
> --- a/include/linux/of_platform.h
> +++ b/include/linux/of_platform.h
> @@ -72,6 +72,7 @@ extern int of_platform_populate(struct device_node *root,
> const struct of_device_id *matches,
> const struct of_dev_auxdata *lookup,
> struct device *parent);
> +extern bool of_dma_is_coherent(struct device_node *np);
> #else
> static inline int of_platform_populate(struct device_node *root,
> const struct of_device_id *matches,
> @@ -80,6 +81,11 @@ static inline int of_platform_populate(struct device_node *root,
> {
> return -ENODEV;
> }
> +
> +static inline bool of_dma_is_coherent(struct device_node *np)
> +{
> + return false;
> +}
> #endif
>
> #endif /* _LINUX_OF_PLATFORM_H */
> --
> 1.7.9.5
>