diff options
author | Thierry Reding <treding@nvidia.com> | 2019-03-21 21:09:58 +0300 |
---|---|---|
committer | Simon Glass <sjg@chromium.org> | 2019-04-12 05:10:50 +0300 |
commit | ea1df3e07cc5a4b155e69fcb7f583cb7f4c2cbe3 (patch) | |
tree | 7ea3d9dec579e6379ea3b9f4270a1edfaee5fb4b /scripts | |
parent | c7fbee540e006b4cf6cda9272d0d5c9847b3db11 (diff) | |
download | u-boot-ea1df3e07cc5a4b155e69fcb7f583cb7f4c2cbe3.tar.xz |
libfdt: Add phandle generation helper
The new fdt_generate_phandle() function can be used to generate a new,
unused phandle given a specific device tree blob. The implementation is
somewhat naive in that it simply walks the entire device tree to find
the highest phandle value and then returns a phandle value one higher
than that. A more clever implementation might try to find holes in the
current set of phandle values and fill them. But this implementation is
relatively simple and works reliably.
Also add a test that validates that phandles generated by this new API
are indeed unique.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'scripts')
-rw-r--r-- | scripts/dtc/libfdt/fdt_ro.c | 31 | ||||
-rw-r--r-- | scripts/dtc/libfdt/libfdt.h | 19 | ||||
-rw-r--r-- | scripts/dtc/libfdt/libfdt_env.h | 1 |
3 files changed, 51 insertions, 0 deletions
diff --git a/scripts/dtc/libfdt/fdt_ro.c b/scripts/dtc/libfdt/fdt_ro.c index dfb3236da3..dc499884e4 100644 --- a/scripts/dtc/libfdt/fdt_ro.c +++ b/scripts/dtc/libfdt/fdt_ro.c @@ -115,6 +115,37 @@ uint32_t fdt_get_max_phandle(const void *fdt) return 0; } +int fdt_generate_phandle(const void *fdt, uint32_t *phandle) +{ + uint32_t max = 0; + int offset = -1; + + while (true) { + uint32_t value; + + offset = fdt_next_node(fdt, offset, NULL); + if (offset < 0) { + if (offset == -FDT_ERR_NOTFOUND) + break; + + return offset; + } + + value = fdt_get_phandle(fdt, offset); + + if (value > max) + max = value; + } + + if (max == FDT_MAX_PHANDLE) + return -FDT_ERR_NOPHANDLES; + + if (phandle) + *phandle = max + 1; + + return 0; +} + int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size) { FDT_CHECK_HEADER(fdt); diff --git a/scripts/dtc/libfdt/libfdt.h b/scripts/dtc/libfdt/libfdt.h index fd73688f9e..cf86ddba88 100644 --- a/scripts/dtc/libfdt/libfdt.h +++ b/scripts/dtc/libfdt/libfdt.h @@ -139,6 +139,10 @@ #define FDT_ERR_MAX 17 +/* constants */ +#define FDT_MAX_PHANDLE 0xfffffffe + /* Valid values for phandles range from 1 to 2^32-2. */ + /**********************************************************************/ /* Low-level functions (you probably don't need these) */ /**********************************************************************/ @@ -314,6 +318,21 @@ const char *fdt_string(const void *fdt, int stroffset); uint32_t fdt_get_max_phandle(const void *fdt); /** + * fdt_generate_phandle - return a new, unused phandle for a device tree blob + * @fdt: pointer to the device tree blob + * @phandle: return location for the new phandle + * + * Walks the device tree blob and looks for the highest phandle value. On + * success, the new, unused phandle value (one higher than the previously + * highest phandle value in the device tree blob) will be returned in the + * @phandle parameter. + * + * Returns: + * 0 on success or a negative error-code on failure + */ +int fdt_generate_phandle(const void *fdt, uint32_t *phandle); + +/** * fdt_num_mem_rsv - retrieve the number of memory reserve map entries * @fdt: pointer to the device tree blob * diff --git a/scripts/dtc/libfdt/libfdt_env.h b/scripts/dtc/libfdt/libfdt_env.h index bd24746287..3ff9e28630 100644 --- a/scripts/dtc/libfdt/libfdt_env.h +++ b/scripts/dtc/libfdt/libfdt_env.h @@ -52,6 +52,7 @@ * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ +#include <stdbool.h> #include <stddef.h> #include <stdint.h> #include <stdlib.h> |