| Message ID | 1309449370-9554-1-git-send-email-thomas.abraham@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Thu, Jun 30, 2011 at 09:26:10PM +0530, Thomas Abraham wrote: > Add helper functions to retrive unsigned integer and string property values from > properties of a device node. These helper functions can be used to lookup a > property in a device node, perform error checking and read the property value. > > [grant.likely@secretlab.ca: Proposal and initial implementation] > Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org> Merged, thanks. Bonus points to anyone who submits patches converting existing code to this new api. g. > --- > drivers/of/base.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/of.h | 4 +++ > 2 files changed, 63 insertions(+), 0 deletions(-) > > diff --git a/drivers/of/base.c b/drivers/of/base.c > index 632ebae..4823b53 100644 > --- a/drivers/of/base.c > +++ b/drivers/of/base.c > @@ -596,6 +596,65 @@ struct device_node *of_find_node_by_phandle(phandle handle) > EXPORT_SYMBOL(of_find_node_by_phandle); > > /** > + * of_property_read_u32 - Find a property in a device node and read the > + * 32-bit property value > + * @np: device node from which the property value is to be read. > + * @propname: name of the property to be searched. > + * @out_value: returned value, valid if return value is 0. > + * > + * Search for a property in a device node and read a 32-bit value from a > + * property. Returns -EINVAL, if the property does not exist, -ENODATA, if > + * property does not have a value, -EOVERFLOW, if the property data isn't > + * large enough, and 0 on success. > + * > + * The out_value is modified only if a valid u32 value can be decoded. > + */ > +int of_property_read_u32(struct device_node *np, char *propname, u32 *out_value) > +{ > + struct property *prop = of_find_property(np, propname, NULL); > + > + if (!prop) > + return -EINVAL; > + if (!prop->value) > + return -ENODATA; > + if (sizeof(*out_value) > prop->length) > + return -EOVERFLOW; > + *out_value = be32_to_cpup(prop->value); > + return 0; > +} > +EXPORT_SYMBOL_GPL(of_property_read_u32); > + > +/** > + * of_property_read_string - Find a property in a device node and return a > + * pointer to the property string value. > + * @np: device node from which the property value is to be read. > + * @propname: name of the property to be searched. > + * @out_string: pointer to a null terminated string, valid only if the return > + * value is 0. > + * > + * Returns a pointer to a null terminated property value string. Returns > + * -EINVAL, if the property does not exist, -ENODATA, if property does not have > + * a value, -EILSEQ, if the string is not null-terminated within the length of > + * the property value, and 0 on success. > + * > + * The out_string value is modified only if a valid string can be decoded. > + */ > +int of_property_read_string(struct device_node *np, char *propname, > + char **out_string) > +{ > + struct property *prop = of_find_property(np, propname, NULL); > + if (!prop) > + return -EINVAL; > + if (!prop->value) > + return -ENODATA; > + if (strnlen(prop->value, prop->length) == prop->length) > + return -EILSEQ; > + *out_string = prop->value; > + return 0; > +} > +EXPORT_SYMBOL_GPL(of_property_read_string); > + > +/** > * of_parse_phandle - Resolve a phandle property to a device_node pointer > * @np: Pointer to device node holding phandle property > * @phandle_name: Name of property holding a phandle value > diff --git a/include/linux/of.h b/include/linux/of.h > index bfc0ed1..4fc4c1b 100644 > --- a/include/linux/of.h > +++ b/include/linux/of.h > @@ -195,6 +195,10 @@ 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_u32(struct device_node *np, char *propname, > + u32 *out_value); > +extern int of_property_read_string(struct device_node *np, char *propname, > + char **out_string); > extern int of_device_is_compatible(const struct device_node *device, > const char *); > extern int of_device_is_available(const struct device_node *device); > -- > 1.6.6.rc2 >
On Thu, Jun 30, 2011 at 12:13:53PM -0600, Grant Likely wrote: > On Thu, Jun 30, 2011 at 09:26:10PM +0530, Thomas Abraham wrote: > > Add helper functions to retrive unsigned integer and string property values from > > properties of a device node. These helper functions can be used to lookup a > > property in a device node, perform error checking and read the property value. > > > > [grant.likely@secretlab.ca: Proposal and initial implementation] > > Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org> > > Merged, thanks. Bonus points to anyone who submits patches converting > existing code to this new api. > > g. > > > --- > > drivers/of/base.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++ > > include/linux/of.h | 4 +++ > > 2 files changed, 63 insertions(+), 0 deletions(-) > > > > diff --git a/drivers/of/base.c b/drivers/of/base.c > > index 632ebae..4823b53 100644 > > --- a/drivers/of/base.c > > +++ b/drivers/of/base.c > > @@ -596,6 +596,65 @@ struct device_node *of_find_node_by_phandle(phandle handle) > > EXPORT_SYMBOL(of_find_node_by_phandle); > > > > /** > > + * of_property_read_u32 - Find a property in a device node and read the > > + * 32-bit property value > > + * @np: device node from which the property value is to be read. > > + * @propname: name of the property to be searched. > > + * @out_value: returned value, valid if return value is 0. > > + * > > + * Search for a property in a device node and read a 32-bit value from a > > + * property. Returns -EINVAL, if the property does not exist, -ENODATA, if > > + * property does not have a value, -EOVERFLOW, if the property data isn't > > + * large enough, and 0 on success. > > + * > > + * The out_value is modified only if a valid u32 value can be decoded. > > + */ > > +int of_property_read_u32(struct device_node *np, char *propname, u32 *out_value) > > +{ > > + struct property *prop = of_find_property(np, propname, NULL); > > + > > + if (!prop) > > + return -EINVAL; > > + if (!prop->value) > > + return -ENODATA; > > + if (sizeof(*out_value) > prop->length) > > + return -EOVERFLOW; > > + *out_value = be32_to_cpup(prop->value); > > + return 0; > > +} > > +EXPORT_SYMBOL_GPL(of_property_read_u32); > > + > > +/** > > + * of_property_read_string - Find a property in a device node and return a > > + * pointer to the property string value. > > + * @np: device node from which the property value is to be read. > > + * @propname: name of the property to be searched. > > + * @out_string: pointer to a null terminated string, valid only if the return > > + * value is 0. > > + * > > + * Returns a pointer to a null terminated property value string. Returns > > + * -EINVAL, if the property does not exist, -ENODATA, if property does not have > > + * a value, -EILSEQ, if the string is not null-terminated within the length of > > + * the property value, and 0 on success. > > + * > > + * The out_string value is modified only if a valid string can be decoded. > > + */ > > +int of_property_read_string(struct device_node *np, char *propname, > > + char **out_string) When converting my dt code to use this api, the following type mismatch warning is being seen in a lot of places. 'char **' but argument is of type 'const char **' This is because the existing codes usually get string from of_get_property and assign it to a 'const char *'. I'm wondering if we should drop the const during converting or change the api with const added to out_string to get converting a little bit easier. Regards, Shawn > > +{ > > + struct property *prop = of_find_property(np, propname, NULL); > > + if (!prop) > > + return -EINVAL; > > + if (!prop->value) > > + return -ENODATA; > > + if (strnlen(prop->value, prop->length) == prop->length) > > + return -EILSEQ; > > + *out_string = prop->value; > > + return 0; > > +} > > +EXPORT_SYMBOL_GPL(of_property_read_string); > > + > > +/** > > * of_parse_phandle - Resolve a phandle property to a device_node pointer > > * @np: Pointer to device node holding phandle property > > * @phandle_name: Name of property holding a phandle value > > diff --git a/include/linux/of.h b/include/linux/of.h > > index bfc0ed1..4fc4c1b 100644 > > --- a/include/linux/of.h > > +++ b/include/linux/of.h > > @@ -195,6 +195,10 @@ 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_u32(struct device_node *np, char *propname, > > + u32 *out_value); > > +extern int of_property_read_string(struct device_node *np, char *propname, > > + char **out_string); > > extern int of_device_is_compatible(const struct device_node *device, > > const char *); > > extern int of_device_is_available(const struct device_node *device); > > -- > > 1.6.6.rc2 > > > _______________________________________________ > devicetree-discuss mailing list > devicetree-discuss@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/devicetree-discuss >
On Sun, Jul 03, 2011 at 11:55:28AM +0800, Shawn Guo wrote: > On Thu, Jun 30, 2011 at 12:13:53PM -0600, Grant Likely wrote: > > On Thu, Jun 30, 2011 at 09:26:10PM +0530, Thomas Abraham wrote: > > > Add helper functions to retrive unsigned integer and string property values from > > > properties of a device node. These helper functions can be used to lookup a > > > property in a device node, perform error checking and read the property value. > > > > > > [grant.likely@secretlab.ca: Proposal and initial implementation] > > > Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org> > > > > Merged, thanks. Bonus points to anyone who submits patches converting > > existing code to this new api. > > > > g. > > > > > --- > > > drivers/of/base.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++ > > > include/linux/of.h | 4 +++ > > > 2 files changed, 63 insertions(+), 0 deletions(-) > > > > > > diff --git a/drivers/of/base.c b/drivers/of/base.c > > > index 632ebae..4823b53 100644 > > > --- a/drivers/of/base.c > > > +++ b/drivers/of/base.c > > > @@ -596,6 +596,65 @@ struct device_node *of_find_node_by_phandle(phandle handle) > > > EXPORT_SYMBOL(of_find_node_by_phandle); > > > > > > /** > > > + * of_property_read_u32 - Find a property in a device node and read the > > > + * 32-bit property value > > > + * @np: device node from which the property value is to be read. > > > + * @propname: name of the property to be searched. > > > + * @out_value: returned value, valid if return value is 0. > > > + * > > > + * Search for a property in a device node and read a 32-bit value from a > > > + * property. Returns -EINVAL, if the property does not exist, -ENODATA, if > > > + * property does not have a value, -EOVERFLOW, if the property data isn't > > > + * large enough, and 0 on success. > > > + * > > > + * The out_value is modified only if a valid u32 value can be decoded. > > > + */ > > > +int of_property_read_u32(struct device_node *np, char *propname, u32 *out_value) > > > +{ > > > + struct property *prop = of_find_property(np, propname, NULL); > > > + > > > + if (!prop) > > > + return -EINVAL; > > > + if (!prop->value) > > > + return -ENODATA; > > > + if (sizeof(*out_value) > prop->length) > > > + return -EOVERFLOW; > > > + *out_value = be32_to_cpup(prop->value); > > > + return 0; > > > +} > > > +EXPORT_SYMBOL_GPL(of_property_read_u32); > > > + > > > +/** > > > + * of_property_read_string - Find a property in a device node and return a > > > + * pointer to the property string value. > > > + * @np: device node from which the property value is to be read. > > > + * @propname: name of the property to be searched. > > > + * @out_string: pointer to a null terminated string, valid only if the return > > > + * value is 0. > > > + * > > > + * Returns a pointer to a null terminated property value string. Returns > > > + * -EINVAL, if the property does not exist, -ENODATA, if property does not have > > > + * a value, -EILSEQ, if the string is not null-terminated within the length of > > > + * the property value, and 0 on success. > > > + * > > > + * The out_string value is modified only if a valid string can be decoded. > > > + */ > > > +int of_property_read_string(struct device_node *np, char *propname, > > > + char **out_string) > > When converting my dt code to use this api, the following type > mismatch warning is being seen in a lot of places. > > 'char **' but argument is of type 'const char **' > > This is because the existing codes usually get string from > of_get_property and assign it to a 'const char *'. > > I'm wondering if we should drop the const during converting or > change the api with const added to out_string to get converting > a little bit easier. Add the const to out_string. It's the right thing to do. Can you craft and post a patch doing so? g.
diff --git a/drivers/of/base.c b/drivers/of/base.c index 632ebae..4823b53 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -596,6 +596,65 @@ struct device_node *of_find_node_by_phandle(phandle handle) EXPORT_SYMBOL(of_find_node_by_phandle); /** + * of_property_read_u32 - Find a property in a device node and read the + * 32-bit property value + * @np: device node from which the property value is to be read. + * @propname: name of the property to be searched. + * @out_value: returned value, valid if return value is 0. + * + * Search for a property in a device node and read a 32-bit value from a + * property. Returns -EINVAL, if the property does not exist, -ENODATA, if + * property does not have a value, -EOVERFLOW, if the property data isn't + * large enough, and 0 on success. + * + * The out_value is modified only if a valid u32 value can be decoded. + */ +int of_property_read_u32(struct device_node *np, char *propname, u32 *out_value) +{ + struct property *prop = of_find_property(np, propname, NULL); + + if (!prop) + return -EINVAL; + if (!prop->value) + return -ENODATA; + if (sizeof(*out_value) > prop->length) + return -EOVERFLOW; + *out_value = be32_to_cpup(prop->value); + return 0; +} +EXPORT_SYMBOL_GPL(of_property_read_u32); + +/** + * of_property_read_string - Find a property in a device node and return a + * pointer to the property string value. + * @np: device node from which the property value is to be read. + * @propname: name of the property to be searched. + * @out_string: pointer to a null terminated string, valid only if the return + * value is 0. + * + * Returns a pointer to a null terminated property value string. Returns + * -EINVAL, if the property does not exist, -ENODATA, if property does not have + * a value, -EILSEQ, if the string is not null-terminated within the length of + * the property value, and 0 on success. + * + * The out_string value is modified only if a valid string can be decoded. + */ +int of_property_read_string(struct device_node *np, char *propname, + char **out_string) +{ + struct property *prop = of_find_property(np, propname, NULL); + if (!prop) + return -EINVAL; + if (!prop->value) + return -ENODATA; + if (strnlen(prop->value, prop->length) == prop->length) + return -EILSEQ; + *out_string = prop->value; + return 0; +} +EXPORT_SYMBOL_GPL(of_property_read_string); + +/** * of_parse_phandle - Resolve a phandle property to a device_node pointer * @np: Pointer to device node holding phandle property * @phandle_name: Name of property holding a phandle value diff --git a/include/linux/of.h b/include/linux/of.h index bfc0ed1..4fc4c1b 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -195,6 +195,10 @@ 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_u32(struct device_node *np, char *propname, + u32 *out_value); +extern int of_property_read_string(struct device_node *np, char *propname, + char **out_string); extern int of_device_is_compatible(const struct device_node *device, const char *); extern int of_device_is_available(const struct device_node *device);
Add helper functions to retrive unsigned integer and string property values from properties of a device node. These helper functions can be used to lookup a property in a device node, perform error checking and read the property value. [grant.likely@secretlab.ca: Proposal and initial implementation] Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org> --- drivers/of/base.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/of.h | 4 +++ 2 files changed, 63 insertions(+), 0 deletions(-)