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author | Viresh Kumar <viresh.kumar@linaro.org> | 2012-11-20 10:15:19 +0530 |
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committer | Rob Herring <rob.herring@calxeda.com> | 2012-11-20 22:58:55 -0600 |
commit | be193249b4178158c0f697cb452b2bbf0cb16361 (patch) | |
tree | 4278eba967e625f0cdb6de865a83038243c51e80 /drivers/of/base.c | |
parent | 9846210b1ec9bbaa30022d6d8af7e55ef67ccb45 (diff) | |
download | op-kernel-dev-be193249b4178158c0f697cb452b2bbf0cb16361.zip op-kernel-dev-be193249b4178158c0f697cb452b2bbf0cb16361.tar.gz |
dt: add helper function to read u8 & u16 variables & arrays
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>
Diffstat (limited to 'drivers/of/base.c')
-rw-r--r-- | drivers/of/base.c | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c index af3b22a..f564e31 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -671,12 +671,89 @@ 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. * * @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, |