Hi Grant,
On 20 June 2011 22:13, Grant Likely grant.likely@secretlab.ca wrote:
Okay, this is getting ugly (not your fault, but this pattern has become too common. Can you craft and post a patch that adds the following functions to drivers/of/base.c and include/linux/of.h
/* offset in cells, not bytes */ int dt_decode_u32(struct *property, int offset, u32 *out_val) { if (!property || !property->value) return -EINVAL; if ((offset + 1) * 4 > property->length) return -EINVAL; *out_val = of_read_number(property->value + (offset * 4), 1); return 0; } int dt_decode_u64(struct *property, int offset, u64 *out_val) { ... } int dt_decode_string(struct *property, int index, char **out_string); { ... }
Plus a set of companion functions: int dt_getprop_u32(struct device_node *np, char *propname, int offset, u32 *out_val) { return dt_decode_u32(of_find_property(np, propname, NULL), offset, out_val); } int dt_getprop_u64(struct *device_node, char *propname, int offset, u64 *out_val); { ... } int dt_getprop_string(struct *device_node, char *propname, int index, char **out_string); { ... }
Then you'll be able to simply do the following to decode each property, with fifosize being left alone if the property cannot be found or decoded:
dt_getprop_u32(pdev->dev.of_node, "samsung,fifosize", &fifosize);
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.
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; + 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 *); extern int of_device_is_available(const struct device_node *device);