dt: add property iteration helpers

This patch adds macros of_property_for_each_u32() and
of_property_for_each_string(), which iterate over an array of values
within a device-tree property. Usage is for example:

struct property *prop;
const __be32 *p;
u32 u;
of_property_for_each_u32(np, "propname", prop, p, u)
	printk("U32 value: %x\n", u);

struct property *prop;
const char *s;
of_property_for_each_string(np, "propname", prop, s)
	printk("String value: %s\n", s);

Based on work by Rob Herring <robherring2@gmail.com>

Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Stephen Warren 2012-04-04 09:27:46 -06:00 committed by Linus Walleij
parent c05127c4e2
commit c541adc637
2 changed files with 76 additions and 0 deletions

View file

@ -1260,3 +1260,44 @@ int of_alias_get_id(struct device_node *np, const char *stem)
return id;
}
EXPORT_SYMBOL_GPL(of_alias_get_id);
const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
u32 *pu)
{
const void *curv = cur;
if (!prop)
return NULL;
if (!cur) {
curv = prop->value;
goto out_val;
}
curv += sizeof(*cur);
if (curv >= prop->value + prop->length)
return NULL;
out_val:
*pu = be32_to_cpup(curv);
return curv;
}
EXPORT_SYMBOL_GPL(of_prop_next_u32);
const char *of_prop_next_string(struct property *prop, const char *cur)
{
const void *curv = cur;
if (!prop)
return NULL;
if (!cur)
return prop->value;
curv += strlen(cur) + 1;
if (curv >= prop->value + prop->length)
return NULL;
return curv;
}
EXPORT_SYMBOL_GPL(of_prop_next_string);

View file

@ -259,6 +259,37 @@ extern void of_detach_node(struct device_node *);
#endif
#define of_match_ptr(_ptr) (_ptr)
/*
* struct property *prop;
* const __be32 *p;
* u32 u;
*
* of_property_for_each_u32(np, "propname", prop, p, u)
* printk("U32 value: %x\n", u);
*/
const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
u32 *pu);
#define of_property_for_each_u32(np, propname, prop, p, u) \
for (prop = of_find_property(np, propname, NULL), \
p = of_prop_next_u32(prop, NULL, &u); \
p; \
p = of_prop_next_u32(prop, p, &u))
/*
* struct property *prop;
* const char *s;
*
* of_property_for_each_string(np, "propname", prop, s)
* printk("String value: %s\n", s);
*/
const char *of_prop_next_string(struct property *prop, const char *cur);
#define of_property_for_each_string(np, propname, prop, s) \
for (prop = of_find_property(np, propname, NULL), \
s = of_prop_next_string(prop, NULL); \
s; \
s = of_prop_next_string(prop, s))
#else /* CONFIG_OF */
static inline bool of_have_populated_dt(void)
@ -349,6 +380,10 @@ static inline int of_machine_is_compatible(const char *compat)
#define of_match_ptr(_ptr) NULL
#define of_match_node(_matches, _node) NULL
#define of_property_for_each_u32(np, propname, prop, p, u) \
while (0)
#define of_property_for_each_string(np, propname, prop, s) \
while (0)
#endif /* CONFIG_OF */
/**