luck/tmp_suning_uos_patched
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dt: add helper function to read u8 & u16 variables & arrays

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This adds following helper routines:
- of_property_read_u8_array()
- of_property_read_u16_array()
- of_property_read_u8()
- of_property_read_u16()

This expects arrays from DT to be passed as:
- u8 array:
	property = /bits/ 8 <0x50 0x60 0x70>;
- u16 array:
	property = /bits/ 16 <0x5000 0x6000 0x7000>;

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
This commit is contained in:
Viresh Kumar 2012-11-20 10:15:19 +05:30 committed by Rob Herring
parent 9846210b1e
commit be193249b4
2 changed files with 107 additions and 0 deletions
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77
drivers/of/base.c
View File

@ -670,6 +670,82 @@ struct device_node *of_find_node_by_phandle(phandle handle)
}
EXPORT_SYMBOL(of_find_node_by_phandle);
/**
* of_property_read_u8_array - Find and read an array of u8 from a property.
*
* @np: device node from which the property value is to be read.
* @propname: name of the property to be searched.
* @out_value: pointer to return value, modified only if return value is 0.
* @sz: number of array elements to read
*
* Search for a property in a device node and read 8-bit value(s) 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.
*
* dts entry of array should be like:
* property = /bits/ 8 <0x50 0x60 0x70>;
*
* The out_value is modified only if a valid u8 value can be decoded.
*/
int of_property_read_u8_array(const struct device_node *np,
const char *propname, u8 *out_values, size_t sz)
{
struct property *prop = of_find_property(np, propname, NULL);
const u8 *val;
if (!prop)
return -EINVAL;
if (!prop->value)
return -ENODATA;
if ((sz * sizeof(*out_values)) > prop->length)
return -EOVERFLOW;
val = prop->value;
while (sz--)
*out_values++ = *val++;
return 0;
}
EXPORT_SYMBOL_GPL(of_property_read_u8_array);
/**
* of_property_read_u16_array - Find and read an array of u16 from a property.
*
* @np: device node from which the property value is to be read.
* @propname: name of the property to be searched.
* @out_value: pointer to return value, modified only if return value is 0.
* @sz: number of array elements to read
*
* Search for a property in a device node and read 16-bit value(s) 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.
*
* dts entry of array should be like:
* property = /bits/ 16 <0x5000 0x6000 0x7000>;
*
* The out_value is modified only if a valid u16 value can be decoded.
*/
int of_property_read_u16_array(const struct device_node *np,
const char *propname, u16 *out_values, size_t sz)
{
struct property *prop = of_find_property(np, propname, NULL);
const __be16 *val;
if (!prop)
return -EINVAL;
if (!prop->value)
return -ENODATA;
if ((sz * sizeof(*out_values)) > prop->length)
return -EOVERFLOW;
val = prop->value;
while (sz--)
*out_values++ = be16_to_cpup(val++);
return 0;
}
EXPORT_SYMBOL_GPL(of_property_read_u16_array);
/**
* of_property_read_u32_array - Find and read an array of 32 bit integers
* from a property.
@ -677,6 +753,7 @@ EXPORT_SYMBOL(of_find_node_by_phandle);
* @np: device node from which the property value is to be read.
* @propname: name of the property to be searched.
* @out_value: pointer to return value, modified only if return value is 0.
* @sz: number of array elements to read
*
* Search for a property in a device node and read 32-bit value(s) from
* it. Returns 0 on success, -EINVAL if the property does not exist,

30
include/linux/of.h
View File

@ -223,6 +223,10 @@ 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_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,
const char *propname, u16 *out_values, size_t sz);
extern int of_property_read_u32_array(const struct device_node *np,
const char *propname,
u32 *out_values,
@ -364,6 +368,18 @@ static inline struct device_node *of_find_compatible_node(
return NULL;
}
static inline int of_property_read_u8_array(const struct device_node *np,
const char *propname, u8 *out_values, size_t sz)
{
return -ENOSYS;
}
static inline int of_property_read_u16_array(const struct device_node *np,
const char *propname, u16 *out_values, size_t sz)
{
return -ENOSYS;
}
static inline int of_property_read_u32_array(const struct device_node *np,
const char *propname,
u32 *out_values, size_t sz)
@ -470,6 +486,20 @@ static inline bool of_property_read_bool(const struct device_node *np,
return prop ? true : false;
}
static inline int of_property_read_u8(const struct device_node *np,
const char *propname,
u8 *out_value)
{
return of_property_read_u8_array(np, propname, out_value, 1);
}
static inline int of_property_read_u16(const struct device_node *np,
const char *propname,
u16 *out_value)
{
return of_property_read_u16_array(np, propname, out_value, 1);
}
static inline int of_property_read_u32(const struct device_node *np,
const char *propname,
u32 *out_value)