From 09258f1e8b12acc4a2a02b60d942660798038fba Mon Sep 17 00:00:00 2001 From: Abhilash Kesavan Date: Thu, 25 Oct 2012 16:30:58 +0000 Subject: [PATCH] fdt: Add function to get config int from device tree Add a function to look up a configuration item such as machine id and return its value. Note: The code has been taken as is from the Chromium u-boot development tree and needs Simon Glass' sign-off. Signed-off-by: Abhilash Kesavan Signed-off-by: Simon Glass --- include/fdtdec.h | 13 +++++++++++++ lib/fdtdec.c | 22 ++++++++++++++++++++++ 2 files changed, 35 insertions(+) diff --git a/include/fdtdec.h b/include/fdtdec.h index 0b14075..d880fe8 100644 --- a/include/fdtdec.h +++ b/include/fdtdec.h @@ -354,6 +354,19 @@ int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, */ int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); +/** + * Look in the FDT for a config item with the given name and return its value + * as a 32-bit integer. The property must have at least 4 bytes of data. The + * value of the first cell is returned. + * + * @param blob FDT blob to use + * @param prop_name Node property name + * @param default_val default value to return if the property is not found + * @return integer value, if found, or default_val if not + */ +int fdtdec_get_config_int(const void *blob, const char *prop_name, + int default_val); + /* * Look up a property in a node and return its contents in a byte * array of given length. The property must have at least enough data for diff --git a/lib/fdtdec.c b/lib/fdtdec.c index 4c23f45..1f50022 100644 --- a/lib/fdtdec.c +++ b/lib/fdtdec.c @@ -512,3 +512,25 @@ const u8 *fdtdec_locate_byte_array(const void *blob, int node, return NULL; return cell; } + +/** + * Look in the FDT for a config item with the given name and return its value + * as a 32-bit integer. The property must have at least 4 bytes of data. The + * value of the first cell is returned. + * + * @param blob FDT blob to use + * @param prop_name Node property name + * @param default_val default value to return if the property is not found + * @return integer value, if found, or default_val if not + */ +int fdtdec_get_config_int(const void *blob, const char *prop_name, + int default_val) +{ + int config_node; + + debug("%s: %s\n", __func__, prop_name); + config_node = fdt_path_offset(blob, "/config"); + if (config_node < 0) + return default_val; + return fdtdec_get_int(blob, config_node, prop_name, default_val); +}