| Message ID | 1364015633-18580-2-git-send-email-linux@prisktech.co.nz (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, 23 Mar 2013 18:13:47 +1300, Tony Prisk <linux@prisktech.co.nz> wrote: > 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: Tony Prisk <linux@prisktech.co.nz> > --- > cc: Grant Likely <grant.likely@secretlab.ca> > cc: Rob Herring <rob.herring@calxeda.com> > cc: devicetree-discuss@lists.ozlabs.org > > Hi Rob/Grant, > After a review of my pinctrl driver, it was suggested that one of the helper > functions be moved into the OF subsystem. Could you review and ack this patch > if you're happy with it. Hey Tony, Instead of implementing this as a sparate function, this should be done as an extension to the of_proprety_read_u32_array() interface, just like how of_property_read_u32() is implemented. It will result in less code that way. So, rename of_property_read_u32_array() to __of_property_read_u32() and add a 'index' argument to it. Then of_property_read_u32_index() can be implemented as: static inline int of_property_read_u32_index(const struct device_node *np, const char *propname, int index, u32 *out_value) { return __of_property_read_u32(np, propname, index, 1, out_value); } And the new of_property_read_u32_array() becomes: static inline int of_property_read_u32_array(const struct device_node *np, const char *propname, int sz, u32 *out_value) { return __of_property_read_u32(np, propname, 0, sz, out_value); } g. > Regards > Tony P > > drivers/of/base.c | 33 +++++++++++++++++++++++++++++++++ > include/linux/of.h | 9 +++++++++ > 2 files changed, 42 insertions(+) > > diff --git a/drivers/of/base.c b/drivers/of/base.c > index 321d3ef..7dc001e 100644 > --- a/drivers/of/base.c > +++ b/drivers/of/base.c > @@ -746,6 +746,39 @@ 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 * 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. > * > * @np: device node from which the property value is to be read. > diff --git a/include/linux/of.h b/include/linux/of.h > index a0f1292..c0747a4 100644 > --- a/include/linux/of.h > +++ b/include/linux/of.h > @@ -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) > { > -- > 1.7.9.5 >
diff --git a/drivers/of/base.c b/drivers/of/base.c index 321d3ef..7dc001e 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -746,6 +746,39 @@ 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 * 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. * * @np: device node from which the property value is to be read. diff --git a/include/linux/of.h b/include/linux/of.h index a0f1292..c0747a4 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -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) {
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: Tony Prisk <linux@prisktech.co.nz> --- cc: Grant Likely <grant.likely@secretlab.ca> cc: Rob Herring <rob.herring@calxeda.com> cc: devicetree-discuss@lists.ozlabs.org Hi Rob/Grant, After a review of my pinctrl driver, it was suggested that one of the helper functions be moved into the OF subsystem. Could you review and ack this patch if you're happy with it. Regards Tony P drivers/of/base.c | 33 +++++++++++++++++++++++++++++++++ include/linux/of.h | 9 +++++++++ 2 files changed, 42 insertions(+)