Add a function to lookup a property which is a phandle in a node, and another to read a fixed-length integer array from an fdt property. Also add a function to read boolean properties.
Signed-off-by: Simon Glass sjg@chromium.org --- include/fdtdec.h | 40 ++++++++++++++++++++++++++ lib/fdtdec.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 122 insertions(+), 0 deletions(-)
diff --git a/include/fdtdec.h b/include/fdtdec.h index 9018181..9ecb6ab 100644 --- a/include/fdtdec.h +++ b/include/fdtdec.h @@ -126,3 +126,43 @@ int fdtdec_get_is_enabled(const void *blob, int node); * if not. */ int fdtdec_check_fdt(void); + +/** + * Look up a phandle and follow it to its node. Then return the offset + * of that node. + * + * @param blob FDT blob + * @param node node to examine + * @param prop_name name of property to find + * @return node offset if found, -ve error code on error + */ +int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); + +/** + * Look up a property in a node and return its contents in an integer + * array of given length. The property must have at least enough data for + * the array (4*count bytes). It may have more, but this will be ignored. + * + * @param blob FDT blob + * @param node node to examine + * @param prop_name name of property to find + * @param array array to fill with data + * @param count number of array elements + * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, + * or -FDT_ERR_BADLAYOUT if not enough data + */ +int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, + int *array, int count); + +/** + * Look up a boolean property in a node and return it. + * + * A boolean properly is true if present in the device tree and false if not + * present, or present with a 0 value. + * + * @param blob FDT blob + * @param node node to examine + * @param prop_name name of property to find + * @return 1 if the properly is present; 0 if it isn't present or is 0 + */ +int fdtdec_get_bool(const void *blob, int node, const char *prop_name); diff --git a/lib/fdtdec.c b/lib/fdtdec.c index d1321a8..613547a 100644 --- a/lib/fdtdec.c +++ b/lib/fdtdec.c @@ -146,3 +146,85 @@ int fdtdec_check_fdt(void) "binary or define CONFIG_OF_EMBED\n"); return 0; } + +int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name) +{ + const u32 *phandle; + int lookup; + + phandle = fdt_getprop(blob, node, prop_name, NULL); + if (!phandle) + return -FDT_ERR_NOTFOUND; + + lookup = fdt_node_offset_by_phandle(blob, fdt32_to_cpu(*phandle)); + return lookup; +} + +/** + * Look up a property in a node and check that it has a minimum length. + * + * @param blob FDT blob + * @param node node to examine + * @param prop_name name of property to find + * @param min_len minimum property length in bytes + * @param err 0 if ok, or -FDT_ERR_NOTFOUND if the property is not + found, or -FDT_ERR_BADLAYOUT if not enough data + * @return pointer to cell, which is only valid if err == 0 + */ +static const void *get_prop_len(const void *blob, int node, + const char *prop_name, int min_len, int *err) +{ + const void *cell; + int len; + + debug("%s: %s\n", __func__, prop_name); + cell = fdt_getprop(blob, node, prop_name, &len); + if (!cell) + *err = -FDT_ERR_NOTFOUND; + else if (len < min_len) + *err = -FDT_ERR_BADLAYOUT; + else + *err = 0; + return cell; +} + +int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, + int *array, int count) +{ + const s32 *cell; + int i, err = 0; + + debug("%s: %s\n", __func__, prop_name); + cell = get_prop_len(blob, node, prop_name, sizeof(s32) * count, &err); + if (!err) { + for (i = 0; i < count; i++) + array[i] = fdt32_to_cpu(cell[i]); + } + return err; +} + +/** + * Look up a boolean property in a node and return it. + * + * A boolean properly is true if present in the device tree and false if not + * present, or present with a 0 value. + * + * @param blob FDT blob + * @param node node to examine + * @param prop_name name of property to find + * @return 1 if the properly is present; 0 if it isn't present or is 0 + */ +int fdtdec_get_bool(const void *blob, int node, const char *prop_name) +{ + const s32 *cell; + int len; + + debug("%s: %s\n", __func__, prop_name); + cell = fdt_getprop(blob, node, prop_name, &len); + if (!cell) + return 0; + if (len >= sizeof(u32) && *cell == 0) + return 0; + + return 1; +}