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Commit 3daf3726 authored by Tony Prisk's avatar Tony Prisk
Browse files

of: Add support for reading a u32 from a multi-value property. 



This patch adds an of_property_read_u32_index() function to allow
reading a single indexed u32 value from a property containing multiple
u32 values.

Signed-off-by: default avatarTony Prisk <linux@prisktech.co.nz>
Reviewed-by: default avatarStephen Warren <swarren@nvidia.com>
Acked-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Acked-by: default avatarRob Herring <robherring2@gmail.com>
parent 8bb96604

drivers/of/base.c

+33 −0
Original line number Diff line number Diff line
@@ -745,6 +745,39 @@ struct device_node *of_find_node_by_phandle(phandle handle) 
}

EXPORT_SYMBOL(of_find_node_by_phandle);



/**

 * of_property_read_u32_index - Find and read a u32 from a multi-value property.

 *

 * @np:		device node from which the property value is to be read.

 * @propname:	name of the property to be searched.

 * @index:	index of the u32 in the list of values

 * @out_value:	pointer to return value, modified only if no error.

 *

 * Search for a property in a device node and read nth 32-bit value from

 * it. Returns 0 on success, -EINVAL if the property does not exist,

 * -ENODATA if property does not have a value, and -EOVERFLOW if the

 * property data isn't large enough.

 *

 * The out_value is modified only if a valid u32 value can be decoded.

 */

int of_property_read_u32_index(const struct device_node *np,

				       const char *propname,

				       u32 index, u32 *out_value)

{

	struct property *prop = of_find_property(np, propname, NULL);



	if (!prop)

		return -EINVAL;

	if (!prop->value)

		return -ENODATA;

	if (((index + 1) * sizeof(*out_value)) > prop->length)

		return -EOVERFLOW;



	*out_value = be32_to_cpup(((__be32 *)prop->value) + index);

	return 0;

}

EXPORT_SYMBOL_GPL(of_property_read_u32_index);



/**

 * of_property_read_u8_array - Find and read an array of u8 from a property.

 *

include/linux/of.h

+9 −0
Original line number Diff line number Diff line
@@ -235,6 +235,9 @@ extern struct device_node *of_find_node_with_property( 
extern struct property *of_find_property(const struct device_node *np,

					 const char *name,

					 int *lenp);

extern int of_property_read_u32_index(const struct device_node *np,

				       const char *propname,

				       u32 index, u32 *out_value);

extern int of_property_read_u8_array(const struct device_node *np,

			const char *propname, u8 *out_values, size_t sz);

extern int of_property_read_u16_array(const struct device_node *np,
@@ -394,6 +397,12 @@ static inline struct device_node *of_find_compatible_node( 
	return NULL;

}



static inline int of_property_read_u32_index(const struct device_node *np,

			const char *propname, u32 index, u32 *out_value)

{

	return -ENOSYS;

}



static inline int of_property_read_u8_array(const struct device_node *np,

			const char *propname, u8 *out_values, size_t sz)

{