On Fri, Jun 24, 2016 at 04:27:52PM +0200, Maxime Ripard wrote:
Add a function to modify inplace a property starting from a given index.
This is especially useful when the property is an array of values, and you want to update one of them without changing the DT size.
Signed-off-by: Maxime Ripard maxime.ripard@free-electrons.com
include/libfdt.h | 34 +++++++++++++++++++++++++++++++--- lib/libfdt/fdt_wip.c | 13 ++++++++----- 2 files changed, 39 insertions(+), 8 deletions(-)
diff --git a/include/libfdt.h b/include/libfdt.h index 4643be5adf39..2c8a42bcb667 100644 --- a/include/libfdt.h +++ b/include/libfdt.h @@ -1032,6 +1032,27 @@ int fdt_size_cells(const void *fdt, int nodeoffset); /* Write-in-place functions */ /**********************************************************************/
+/**
- fdt_setprop_inplace_namelen_by_index - change a property's value,
but not its size
- @fdt: pointer to the device tree blob
- @nodeoffset: offset of the node whose property to change
- @name: name of the property to change
- @namelen: number of characters of name to consider
- @index: index of the property to change in the array
- @val: pointer to data to replace the property value with
- @len: length of the property value
- Identical to fdt_setprop_inplace(), but modifies the given property
- starting from the given index, and using only the first characters
- of the name. It is useful when you want to manipulate only one value of
- an array and you have a string that doesn't end with \0.
- */
+int fdt_setprop_inplace_namelen_by_index(void *fdt, int nodeoffset,
const char *name, int namelen,uint32_t index, const void *val,int len);
This looks like a good addition to upstream, but I don't like the name. I'd suggest fdt_setprop_inplace_namelen_partial() because it only overwrite part of the existing property value.
/**
- fdt_setprop_inplace - change a property's value, but not its size
- @fdt: pointer to the device tree blob
@@ -1060,8 +1081,13 @@ int fdt_size_cells(const void *fdt, int nodeoffset);
- -FDT_ERR_BADSTRUCTURE,
- -FDT_ERR_TRUNCATED, standard meanings
*/ -int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name,
const void *val, int len);+static inline int fdt_setprop_inplace(void *fdt, int nodeoffset,
const char *name, const void *val,int len)+{
- return fdt_setprop_inplace_namelen_by_index(fdt, nodeoffset, name,
strlen(name), 0, val, len);
This effectively removes the error if len is not equal to the existing property length, so that needs to be put back.
+}
/**
- fdt_setprop_inplace_u32 - change the value of a 32-bit integer property
@@ -1095,7 +1121,9 @@ static inline int fdt_setprop_inplace_u32(void *fdt, int nodeoffset, const char *name, uint32_t val) { fdt32_t tmp = cpu_to_fdt32(val);
- return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp));
- return fdt_setprop_inplace_namelen_by_index(fdt, nodeoffset,
name, strlen(name),0, &tmp, sizeof(tmp));}
/** diff --git a/lib/libfdt/fdt_wip.c b/lib/libfdt/fdt_wip.c index 9fe988655fe3..737769fa59e2 100644 --- a/lib/libfdt/fdt_wip.c +++ b/lib/libfdt/fdt_wip.c @@ -14,20 +14,23 @@
#include "libfdt_internal.h"
-int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name,
const void *val, int len)+int fdt_setprop_inplace_namelen_by_index(void *fdt, int nodeoffset,
const char *name, int namelen,uint32_t index, const void *val,int len){ void *propval; int proplen;
- propval = fdt_getprop_w(fdt, nodeoffset, name, &proplen);
- propval = fdt_getprop_namelen_w(fdt, nodeoffset, name, namelen,
&proplen);
- if (proplen != len)
- if (proplen < (len + index)) return -FDT_ERR_NOSPACE;
- memcpy(propval, val, len);
- memcpy(propval + index, val, len); return 0;
}