| Message ID | BANLkTi=RxEpBrALEQbBD_z6ZiEW24-wsng@mail.gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Jun 22, 2011 at 10:22 AM, Thomas Abraham <thomas.abraham@linaro.org> wrote: > > I have added the functions as you have suggested and the diff is > listed below. Could you please review the diff and suggest any changes > required. Thanks Thomas. Comments below... > drivers/of/base.c | 129 ++++++++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/of.h | 10 ++++ > 2 files changed, 139 insertions(+), 0 deletions(-) > > diff --git a/drivers/of/base.c b/drivers/of/base.c > index 632ebae..73f0144 100644 > --- a/drivers/of/base.c > +++ b/drivers/of/base.c > @@ -596,6 +596,135 @@ struct device_node > *of_find_node_by_phandle(phandle handle) > EXPORT_SYMBOL(of_find_node_by_phandle); > > /** > + * of_read_property_u32 - Reads a indexed 32-bit property value > + * @prop: property to read from. > + * @offset: cell number to read. > + * value: returned cell value > + * > + * Returns a indexed 32-bit value of a property cell, -EINVAL in case the cell > + * does not exist > + */ > +int of_read_property_u32(struct property *prop, u32 offset, u32 *value) > +{ > + if (!prop || !prop->value) > + return -EINVAL; Hmmm, it would probably be a good idea to differentiate return code depending on whether or not the property was found vs. the property data not large enough. > + if ((offset + 1) * 4 > prop->length) > + return -EINVAL; > + > + *value = of_read_ulong(prop->value + (offset * 4), 1); > + return 0; Despite the fact that this is exactly what I asked you to write, this ends up being rather ugly. (I originally put in the '*4' to match the behaviour of the existing of_read_number(), but that was a mistake. tglx also pointed it out). How about this instead: int of_read_property_u32(struct property *prop, unsigned int offset, u32 *out_value) { if (!prop || !out_value) return -EINVAL; if (!prop->value) return -ENODATA; if (offset + sizeof(*out_value) > prop->length) return -EOVERFLOW; *out_value = be32_to_cpup(prop->data + offset); return 0; } int of_read_property_u64(struct property *prop, unsigned int offset, u64 *out_value) { if (!prop || !out_value) return -EINVAL; if (!prop->value) return -ENODATA; if (offset + sizeof(*out_value) > prop->length) return -EOVERFLOW; *out_value = be32_to_cpup(prop->value + offset); *out_value = (*out_value << 32) | be32_to_cpup(prop->value + offset + sizeof(u32)); return 0; } > +} > +EXPORT_SYMBOL(of_read_property_u32); EXPORT_SYMBOL_GPL() > + > +/** > + * of_getprop_u32 - Find a property in a device node and read a 32-bit value > + * @np: device node from which the property value is to be read. > + * @propname name of the property to be searched. > + * @offset: cell number to read. > + * @value: returned value of the cell > + * > + * Search for a property in a device node and read a indexed 32-bit value of a > + * property cell. Returns the 32-bit cell value, -EINVAL in case the > property or > + * the indexed cell does not exist. > + */ > +int > +of_getprop_u32(struct device_node *np, char *propname, int offset, u32 *value) > +{ > + return of_read_property_u32(of_find_property(np, propname, NULL), > + offset, value); > +} > +EXPORT_SYMBOL(of_getprop_u32); > + > +/** > + * of_read_property_u64 - Reads a indexed 64-bit property value > + * @prop: property to read from. > + * @offset: cell number to read (each cell is 64-bits). > + * @value: returned cell value > + * > + * Returns a indexed 64-bit value of a property cell, -EINVAL in case the cell > + * does not exist > + */ > +int of_read_property_u64(struct property *prop, int offset, u64 *value) > +{ > + if (!prop || !prop->value) > + return -EINVAL; > + if ((offset + 1) * 8 > prop->length) > + return -EINVAL; > + > + *value = of_read_number(prop->value + (offset * 8), 2); > + return 0; > +} > +EXPORT_SYMBOL(of_read_property_u64); > + > +/** > + * of_getprop_u64 - Find a property in a device node and read a 64-bit value > + * @np: device node from which the property value is to be read. > + * @propname name of the property to be searched. > + * @offset: cell number to read (each cell is 64-bits). > + * @value: returned value of the cell > + * > + * Search for a property in a device node and read a indexed 64-bit value of a > + * property cell. Returns the 64-bit cell value, -EINVAL in case the > property or > + * the indexed cell does not exist. > + */ > +int > +of_getprop_u64(struct device_node *np, char *propname, int offset, u64 *value) > +{ > + return of_read_property_u64(of_find_property(np, propname, NULL), > + offset, value); > +} > +EXPORT_SYMBOL(of_getprop_u64); > + > +/** > + * of_read_property_string - Returns a pointer to a indexed null terminated > + * property value string > + * @prop: property to read from. > + * @offset: index of the property string to be read. > + * @string: pointer to a null terminated string, valid only if the return > + * value is 0. > + * > + * Returns a pointer to a indexed null terminated property cell string, -EINVAL > + * in case the cell does not exist. > + */ > +int of_read_property_string(struct property *prop, int offset, char **string) > +{ > + char *c; > + > + if (!prop || !prop->value) > + return -EINVAL; Ditto here about return values. > + > + c = (char *)prop->value; You don't need the cast. prop->value is a void* pointer. However, 'c' does need to be const char. > + while (offset--) > + while (*c++) > + ; Rather than open coding this, you should use the string library functions. Something like: c = prop->value; while (offset-- && (c - prop->value) < prop->size) c += strlen(c) + 1; if ((c - prop->value) + strlen(c) >= prop->size) return -EOVERFLOW; *out_value = c; Plus it catches more error conditions that way. g.
diff --git a/drivers/of/base.c b/drivers/of/base.c index 632ebae..73f0144 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -596,6 +596,135 @@ struct device_node *of_find_node_by_phandle(phandle handle) EXPORT_SYMBOL(of_find_node_by_phandle); /** + * of_read_property_u32 - Reads a indexed 32-bit property value + * @prop: property to read from. + * @offset: cell number to read. + * value: returned cell value + * + * Returns a indexed 32-bit value of a property cell, -EINVAL in case the cell + * does not exist + */ +int of_read_property_u32(struct property *prop, u32 offset, u32 *value) +{ + if (!prop || !prop->value) + return -EINVAL; + if ((offset + 1) * 4 > prop->length) + return -EINVAL; + + *value = of_read_ulong(prop->value + (offset * 4), 1); + return 0; +} +EXPORT_SYMBOL(of_read_property_u32); + +/** + * of_getprop_u32 - Find a property in a device node and read a 32-bit value + * @np: device node from which the property value is to be read. + * @propname name of the property to be searched. + * @offset: cell number to read. + * @value: returned value of the cell + * + * Search for a property in a device node and read a indexed 32-bit value of a + * property cell. Returns the 32-bit cell value, -EINVAL in case the property or + * the indexed cell does not exist. + */ +int +of_getprop_u32(struct device_node *np, char *propname, int offset, u32 *value) +{ + return of_read_property_u32(of_find_property(np, propname, NULL), + offset, value); +} +EXPORT_SYMBOL(of_getprop_u32); + +/** + * of_read_property_u64 - Reads a indexed 64-bit property value + * @prop: property to read from. + * @offset: cell number to read (each cell is 64-bits). + * @value: returned cell value + * + * Returns a indexed 64-bit value of a property cell, -EINVAL in case the cell + * does not exist + */ +int of_read_property_u64(struct property *prop, int offset, u64 *value) +{ + if (!prop || !prop->value) + return -EINVAL; + if ((offset + 1) * 8 > prop->length) + return -EINVAL; + + *value = of_read_number(prop->value + (offset * 8), 2); + return 0; +} +EXPORT_SYMBOL(of_read_property_u64); + +/** + * of_getprop_u64 - Find a property in a device node and read a 64-bit value + * @np: device node from which the property value is to be read. + * @propname name of the property to be searched. + * @offset: cell number to read (each cell is 64-bits). + * @value: returned value of the cell + * + * Search for a property in a device node and read a indexed 64-bit value of a + * property cell. Returns the 64-bit cell value, -EINVAL in case the property or + * the indexed cell does not exist. + */ +int +of_getprop_u64(struct device_node *np, char *propname, int offset, u64 *value) +{ + return of_read_property_u64(of_find_property(np, propname, NULL), + offset, value); +} +EXPORT_SYMBOL(of_getprop_u64); + +/** + * of_read_property_string - Returns a pointer to a indexed null terminated + * property value string + * @prop: property to read from. + * @offset: index of the property string to be read. + * @string: pointer to a null terminated string, valid only if the return + * value is 0. + * + * Returns a pointer to a indexed null terminated property cell string, -EINVAL + * in case the cell does not exist. + */ +int of_read_property_string(struct property *prop, int offset, char **string) +{ + char *c; + + if (!prop || !prop->value) + return -EINVAL; + + c = (char *)prop->value; + while (offset--) + while (*c++) + ; + + *string = c; + return 0; +} + +/** + * of_getprop_string - Find a property in a device node and read a null + * terminated string property + * @np: device node from which the property value is to be read. + * @propname name of the property to be searched. + * @offset: cell number to read (each cell contains a null-terminated + * string). + * @string: pointer to a null terminated string, valid only if the return + * value is 0. + * + * Search for a property in a device node and return a pointer to a indexed + * string value of a property cell. Returns a pointer to a string, -EINVAL + * in case the property or the indexed cell does not exist. + */ +int of_getprop_string(struct device_node *np, char *propname, int offset, + char **string) +{ + return of_read_property_string(of_find_property(np, propname, NULL), + offset, string); +} +EXPORT_SYMBOL(of_getprop_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..aff2786 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -195,6 +195,16 @@ 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_read_property_u32(struct property *prop, u32 offset, u32 *value); +extern int of_getprop_u32(struct device_node *np, char *propname, int offset, + u32 *value); +extern int of_read_property_u64(struct property *prop, int offset, u64 *value); +extern int of_getprop_u64(struct device_node *np, char *propname, int offset, + u64 *value); +extern int of_read_property_string(struct property *prop, int offset, + char **string); +extern int of_getprop_string(struct device_node *np, char *propname, int offset, + char **string); extern int of_device_is_compatible(const struct device_node *device, const char *);