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Commit 4fcd15a0 authored by Benoit Cousson's avatar Benoit Cousson Committed by Kevin Hilman
Browse files

of: Add helpers to get one string in multiple strings property 



Add of_property_read_string_index and of_property_count_strings
to retrieve one string inside a property that will contains
severals strings.

Signed-off-by: default avatarBenoit Cousson <b-cousson@ti.com>
Acked-by: default avatarGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: default avatarKevin Hilman <khilman@ti.com>
parent f718e2c0

drivers/of/base.c

+84 −0
Original line number Diff line number Diff line
@@ -661,6 +661,90 @@ int of_property_read_string(struct device_node *np, const char *propname, 
}

EXPORT_SYMBOL_GPL(of_property_read_string);



/**

 * of_property_read_string_index - Find and read a string from a multiple

 * strings 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 string in the list of strings

 * @out_string:	pointer to null terminated return string, modified only if

 *		return value is 0.

 *

 * Search for a property in a device tree node and retrieve a null

 * terminated string value (pointer to data, not a copy) in the list of strings

 * contained in that property.

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

 * property does not have a value, and -EILSEQ if the string is not

 * null-terminated within the length of the property data.

 *

 * The out_string pointer is modified only if a valid string can be decoded.

 */

int of_property_read_string_index(struct device_node *np, const char *propname,

				  int index, const char **output)

{

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

	int i = 0;

	size_t l = 0, total = 0;

	const char *p;



	if (!prop)

		return -EINVAL;

	if (!prop->value)

		return -ENODATA;

	if (strnlen(prop->value, prop->length) >= prop->length)

		return -EILSEQ;



	p = prop->value;



	for (i = 0; total < prop->length; total += l, p += l) {

		l = strlen(p) + 1;

		if ((*p != 0) && (i++ == index)) {

			*output = p;

			return 0;

		}

	}

	return -ENODATA;

}

EXPORT_SYMBOL_GPL(of_property_read_string_index);





/**

 * of_property_count_strings - Find and return the number of strings from a

 * multiple strings property.

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

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

 *

 * Search for a property in a device tree node and retrieve the number of null

 * terminated string contain in it. Returns the number of strings on

 * success, -EINVAL if the property does not exist, -ENODATA if property

 * does not have a value, and -EILSEQ if the string is not null-terminated

 * within the length of the property data.

 */

int of_property_count_strings(struct device_node *np, const char *propname)

{

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

	int i = 0;

	size_t l = 0, total = 0;

	const char *p;



	if (!prop)

		return -EINVAL;

	if (!prop->value)

		return -ENODATA;

	if (strnlen(prop->value, prop->length) >= prop->length)

		return -EILSEQ;



	p = prop->value;



	for (i = 0; total < prop->length; total += l, p += l) {

		l = strlen(p) + 1;

		if (*p != 0)

			i++;

	}

	return i;

}

EXPORT_SYMBOL_GPL(of_property_count_strings);



/**

 * of_parse_phandle - Resolve a phandle property to a device_node pointer

 * @np: Pointer to device node holding phandle property

include/linux/of.h

+18 −0
Original line number Diff line number Diff line
@@ -203,6 +203,11 @@ extern int of_property_read_u32_array(const struct device_node *np, 
extern int of_property_read_string(struct device_node *np,

				   const char *propname,

				   const char **out_string);

extern int of_property_read_string_index(struct device_node *np,

					 const char *propname,

					 int index, const char **output);

extern int of_property_count_strings(struct device_node *np,

				     const char *propname);

extern int of_device_is_compatible(const struct device_node *device,

				   const char *);

extern int of_device_is_available(const struct device_node *device);
@@ -256,6 +261,19 @@ static inline int of_property_read_string(struct device_node *np, 
	return -ENOSYS;

}



static inline int of_property_read_string_index(struct device_node *np,

						const char *propname, int index,

						const char **out_string)

{

	return -ENOSYS;

}



static inline int of_property_count_strings(struct device_node *np,

					    const char *propname)

{

	return -ENOSYS;

}



static inline const void *of_get_property(const struct device_node *node,

				const char *name,

				int *lenp)