[U-Boot-Users] fdt_find_compatible_node() and friends
Wolfgang Grandegger
wg at grandegger.com
Wed May 16 12:40:23 CEST 2007
Hi Jerry,
any intention to merge these patches?
Thanks,
Wolfgang.
Wolfgang Grandegger wrote:
> Hi Jerry,
>
> Jerry Van Baren wrote:
>> Wolfgang Grandegger wrote:
>>> Hi Jerry,
>>>
>>> before re-coding fdt_find_compatible_node(), some more comments.
>>>
>>> After browsing more carefully the FDT related code of "arch/powerpc"
>>> I think we also need, apart from fdt_find_compatible_node() and
>>> fdt_path_offset(), fdt_find_node_by_type() and maybe
>>> fdt_find_node_by_name(). These functions do a sequential scan of all
>>> devices starting at the beginning or after a specified node. They
>>> actually ignore the hierarchy. Do you agree?
>>> BTW: any reason why not using the more compatible name
>>> fdt_find_node_by_path() for fdt_path_offset()?
>>>
>>> Wolfgang.
>>
>> Hi WolfganG,
>>
>> I'm not an expert, I just fake it on email ;-). With that disclaimer,
>> I would agree with you WRT all the "find" functions. The original
>> libfdt code does not support any "find" functions, so we will need to
>> add them.
>>
>> WRT to fdt_find_node_by_path() vs. fdt_path_offset(), I vaguely recall
>> some renames happening in the kernel source, but I cannot find them so
>> my memory likely is faulty[1]. I would be strongly in favor of
>> following the kernel's lead and renaming that function since we are
>> already divergent from the original libfdt. The kernel's name is a
>> much better description.
>
> OK, I have attached two new patches replacing fdt_path_offset() with
> fdt_find_node_by_path() and implementing fdt_find_node_by_type() and
> fdt_find_compatible_node(). This version does not use static variables
> any more to scan the nodes without re-scanning, but looks for the end
> tag. I think it's (almost) good enough to be applied.
>
> Wolfgang.
>
>
> ------------------------------------------------------------------------
>
> Replace fdt_node_offset() with fdt_find_node_by_path().
>
> From: Wolfgang Grandegger <wg at grandegger.com>
>
> The new name matches more closely the kernel's name, which is also
> a much better description.
> ---
>
> board/mpc8360emds/mpc8360emds.c | 2 +-
> board/mpc8360emds/pci.c | 2 +-
> common/cmd_fdt.c | 6 +++---
> common/fdt_support.c | 10 +++++-----
> cpu/mpc83xx/cpu.c | 2 +-
> include/libfdt.h | 2 +-
> libfdt/fdt_ro.c | 2 +-
> 7 files changed, 13 insertions(+), 13 deletions(-)
>
> diff --git a/board/mpc8360emds/mpc8360emds.c b/board/mpc8360emds/mpc8360emds.c
> index 562eb8b..3f87f09 100644
> --- a/board/mpc8360emds/mpc8360emds.c
> +++ b/board/mpc8360emds/mpc8360emds.c
> @@ -681,7 +681,7 @@ ft_board_setup(void *blob, bd_t *bd)
> int nodeoffset;
> int tmp[2];
>
> - nodeoffset = fdt_path_offset (fdt, "/memory");
> + nodeoffset = fdt_find_node_by_path (fdt, "/memory");
> if (nodeoffset >= 0) {
> tmp[0] = cpu_to_be32(bd->bi_memstart);
> tmp[1] = cpu_to_be32(bd->bi_memsize);
> diff --git a/board/mpc8360emds/pci.c b/board/mpc8360emds/pci.c
> index 158effe..4c7a82b 100644
> --- a/board/mpc8360emds/pci.c
> +++ b/board/mpc8360emds/pci.c
> @@ -311,7 +311,7 @@ ft_pci_setup(void *blob, bd_t *bd)
> int err;
> int tmp[2];
>
> - nodeoffset = fdt_path_offset (fdt, "/" OF_SOC "/pci at 8500");
> + nodeoffset = fdt_find_node_by_path (fdt, "/" OF_SOC "/pci at 8500");
> if (nodeoffset >= 0) {
> tmp[0] = cpu_to_be32(hose[0].first_busno);
> tmp[1] = cpu_to_be32(hose[0].last_busno);
> diff --git a/common/cmd_fdt.c b/common/cmd_fdt.c
> index 08fe351..7058197 100644
> --- a/common/cmd_fdt.c
> +++ b/common/cmd_fdt.c
> @@ -177,7 +177,7 @@ int do_fdt (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
> if (strcmp(pathp, "/") == 0) {
> nodeoffset = 0;
> } else {
> - nodeoffset = fdt_path_offset (fdt, pathp);
> + nodeoffset = fdt_find_node_by_path (fdt, pathp);
> if (nodeoffset < 0) {
> /*
> * Not found or something else bad happened.
> @@ -306,7 +306,7 @@ int do_fdt (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
> nodeoffset = 0;
> printf("/");
> } else {
> - nodeoffset = fdt_path_offset (fdt, pathp);
> + nodeoffset = fdt_find_node_by_path (fdt, pathp);
> if (nodeoffset < 0) {
> /*
> * Not found or something else bad happened.
> @@ -405,7 +405,7 @@ int do_fdt (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
> if (strcmp(argv[2], "/") == 0) {
> nodeoffset = 0;
> } else {
> - nodeoffset = fdt_path_offset (fdt, argv[2]);
> + nodeoffset = fdt_find_node_by_path (fdt, argv[2]);
> if (nodeoffset < 0) {
> /*
> * Not found or something else bad happened.
> diff --git a/common/fdt_support.c b/common/fdt_support.c
> index 69099c4..05bf939 100644
> --- a/common/fdt_support.c
> +++ b/common/fdt_support.c
> @@ -92,7 +92,7 @@ int fdt_chosen(void *fdt, ulong initrd_start, ulong initrd_end, int force)
> /*
> * Find the "chosen" node.
> */
> - nodeoffset = fdt_path_offset (fdt, "/chosen");
> + nodeoffset = fdt_find_node_by_path (fdt, "/chosen");
>
> /*
> * If we have a "chosen" node already the "force the writing"
> @@ -140,7 +140,7 @@ int fdt_chosen(void *fdt, ulong initrd_start, ulong initrd_end, int force)
> printf("libfdt: %s\n", fdt_strerror(err));
> #endif
>
> - nodeoffset = fdt_path_offset (fdt, "/cpus");
> + nodeoffset = fdt_find_node_by_path (fdt, "/cpus");
> if (nodeoffset >= 0) {
> clock = cpu_to_be32(bd->bi_intfreq);
> err = fdt_setprop(fdt, nodeoffset, "clock-frequency", &clock, 4);
> @@ -148,7 +148,7 @@ int fdt_chosen(void *fdt, ulong initrd_start, ulong initrd_end, int force)
> printf("libfdt: %s\n", fdt_strerror(err));
> }
> #ifdef OF_TBCLK
> - nodeoffset = fdt_path_offset (fdt, "/cpus/" OF_CPU "/timebase-frequency");
> + nodeoffset = fdt_find_node_by_path (fdt, "/cpus/" OF_CPU "/timebase-frequency");
> if (nodeoffset >= 0) {
> clock = cpu_to_be32(OF_TBCLK);
> err = fdt_setprop(fdt, nodeoffset, "clock-frequency", &clock, 4);
> @@ -185,7 +185,7 @@ int fdt_env(void *fdt)
> * See if we already have a "u-boot-env" node, delete it if so.
> * Then create a new empty node.
> */
> - nodeoffset = fdt_path_offset (fdt, "/u-boot-env");
> + nodeoffset = fdt_find_node_by_path (fdt, "/u-boot-env");
> if (nodeoffset >= 0) {
> err = fdt_del_node(fdt, nodeoffset);
> if (err < 0) {
> @@ -305,7 +305,7 @@ int fdt_bd_t(void *fdt)
> * See if we already have a "bd_t" node, delete it if so.
> * Then create a new empty node.
> */
> - nodeoffset = fdt_path_offset (fdt, "/bd_t");
> + nodeoffset = fdt_find_node_by_path (fdt, "/bd_t");
> if (nodeoffset >= 0) {
> err = fdt_del_node(fdt, nodeoffset);
> if (err < 0) {
> diff --git a/cpu/mpc83xx/cpu.c b/cpu/mpc83xx/cpu.c
> index e934ba6..ef44581 100644
> --- a/cpu/mpc83xx/cpu.c
> +++ b/cpu/mpc83xx/cpu.c
> @@ -460,7 +460,7 @@ ft_cpu_setup(void *blob, bd_t *bd)
> int j;
>
> for (j = 0; j < (sizeof(fixup_props) / sizeof(fixup_props[0])); j++) {
> - nodeoffset = fdt_path_offset(fdt, fixup_props[j].node);
> + nodeoffset = fdt_find_node_by_path(fdt, fixup_props[j].node);
> if (nodeoffset >= 0) {
> err = (*fixup_props[j].set_fn)(blob, nodeoffset, fixup_props[j].prop, bd);
> if (err < 0)
> diff --git a/include/libfdt.h b/include/libfdt.h
> index f8bac73..e080028 100644
> --- a/include/libfdt.h
> +++ b/include/libfdt.h
> @@ -77,7 +77,7 @@ int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
> const char *name, int namelen);
> int fdt_subnode_offset(const void *fdt, int parentoffset, const char *name);
>
> -int fdt_path_offset(const void *fdt, const char *path);
> +int fdt_find_node_by_path(const void *fdt, const char *path);
>
> struct fdt_property *fdt_get_property(const void *fdt, int nodeoffset,
> const char *name, int *lenp);
> diff --git a/libfdt/fdt_ro.c b/libfdt/fdt_ro.c
> index 4e2c325..e5518c6 100644
> --- a/libfdt/fdt_ro.c
> +++ b/libfdt/fdt_ro.c
> @@ -129,7 +129,7 @@ int fdt_subnode_offset(const void *fdt, int parentoffset,
> * Searches for the node corresponding to the given path and returns the
> * offset of that node.
> */
> -int fdt_path_offset(const void *fdt, const char *path)
> +int fdt_find_node_by_path(const void *fdt, const char *path)
> {
> const char *end = path + strlen(path);
> const char *p = path;
>
>
> ------------------------------------------------------------------------
>
> Add fdt_find_node_by_type() and fdt_find_compatible_node() to LIBFDT
>
> From: Wolfgang Grandegger <wg at grandegger.com>
>
>
> ---
>
> include/libfdt.h | 6 ++
> libfdt/fdt_ro.c | 161 ++++++++++++++++++++++++++++++++++++++++++++++++------
> 2 files changed, 149 insertions(+), 18 deletions(-)
>
> diff --git a/include/libfdt.h b/include/libfdt.h
> index e080028..340e89d 100644
> --- a/include/libfdt.h
> +++ b/include/libfdt.h
> @@ -78,6 +78,12 @@ int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
> int fdt_subnode_offset(const void *fdt, int parentoffset, const char *name);
>
> int fdt_find_node_by_path(const void *fdt, const char *path);
> +int fdt_find_node_by_type(const void *fdt, int nodeoffset, const char *type);
> +
> +int fdt_node_is_compatible(const void *fdt, int nodeoffset,
> + const char *compat);
> +int fdt_find_compatible_node(const void *fdt, int nodeoffset,
> + const char *type, const char *compat);
>
> struct fdt_property *fdt_get_property(const void *fdt, int nodeoffset,
> const char *name, int *lenp);
> diff --git a/libfdt/fdt_ro.c b/libfdt/fdt_ro.c
> index e5518c6..e379fc2 100644
> --- a/libfdt/fdt_ro.c
> +++ b/libfdt/fdt_ro.c
> @@ -48,6 +48,33 @@ static int offset_streq(const void *fdt, int offset,
> }
>
> /*
> + * Checks if the property name matches.
> + */
> +static int prop_name_eq(const void *fdt, int offset, const char *name,
> + struct fdt_property **prop, int *lenp)
> +{
> + int namestroff, len;
> +
> + *prop = fdt_offset_ptr_typed(fdt, offset, *prop);
> + if (! *prop)
> + return -FDT_ERR_BADSTRUCTURE;
> +
> + namestroff = fdt32_to_cpu((*prop)->nameoff);
> + if (streq(fdt_string(fdt, namestroff), name)) {
> + len = fdt32_to_cpu((*prop)->len);
> + *prop = fdt_offset_ptr(fdt, offset,
> + sizeof(**prop) + len);
> + if (*prop) {
> + if (lenp)
> + *lenp = len;
> + return 1;
> + } else
> + return -FDT_ERR_BADSTRUCTURE;
> + }
> + return 0;
> +}
> +
> +/*
> * Return a pointer to the string at the given string offset.
> */
> char *fdt_string(const void *fdt, int stroffset)
> @@ -56,6 +83,118 @@ char *fdt_string(const void *fdt, int stroffset)
> }
>
> /*
> + * Check if the specified node is compatible by comparing the tokens
> + * in its "compatible" property with the specified string:
> + *
> + * nodeoffset - starting place of the node
> + * compat - the string to match to one of the tokens in the
> + * "compatible" list.
> + */
> +int fdt_node_is_compatible(const void *fdt, int nodeoffset,
> + const char *compat)
> +{
> + const char* cp;
> + int cplen, len;
> +
> + cp = fdt_getprop(fdt, nodeoffset, "compatible", &cplen);
> + if (cp == NULL)
> + return 0;
> + while (cplen > 0) {
> + if (strncmp(cp, compat, strlen(compat)) == 0)
> + return 1;
> + len = strlen(cp) + 1;
> + cp += len;
> + cplen -= len;
> + }
> +
> + return 0;
> +}
> +
> +/*
> + * Find a node by its device type property. On success, the offset of that
> + * node is returned or an error code otherwise:
> + *
> + * nodeoffset - the node to start searching from or 0, the node you pass
> + * will not be searched, only the next one will; typically,
> + * you pass 0 to start the search and then what the previous
> + * call returned.
> + * type - the device type string to match against.
> + */
> +int fdt_find_node_by_type(const void *fdt, int nodeoffset, const char *type)
> +{
> + int offset, nextoffset;
> + struct fdt_property *prop;
> + uint32_t tag;
> + int len, ret;
> +
> + CHECK_HEADER(fdt);
> +
> + tag = fdt_next_tag(fdt, nodeoffset, &nextoffset, NULL);
> + if (tag != FDT_BEGIN_NODE)
> + return -FDT_ERR_BADOFFSET;
> + if (nodeoffset)
> + nodeoffset = 0; /* start searching with next node */
> +
> + while (1) {
> + offset = nextoffset;
> + tag = fdt_next_tag(fdt, offset, &nextoffset, NULL);
> +
> + switch (tag) {
> + case FDT_BEGIN_NODE:
> + nodeoffset = offset;
> + break;
> +
> + case FDT_PROP:
> + if (nodeoffset == 0)
> + break;
> + ret = prop_name_eq(fdt, offset, "device_type",
> + &prop, &len);
> + if (ret < 0)
> + return ret;
> + else if (ret > 0 &&
> + strncmp(prop->data, type, len - 1) == 0)
> + return nodeoffset;
> + break;
> +
> + case FDT_END_NODE:
> + case FDT_NOP:
> + break;
> +
> + case FDT_END:
> + return -FDT_ERR_NOTFOUND;
> +
> + default:
> + return -FDT_ERR_BADSTRUCTURE;
> + }
> + }
> +}
> +
> +/*
> + * Find a node based on its device type and one of the tokens in its its
> + * "compatible" property. On success, the offset of that node is returned
> + * or an error code otherwise:
> + *
> + * nodeoffset - the node to start searching from or 0, the node you pass
> + * will not be searched, only the next one will; typically,
> + * you pass 0 to start the search and then what the previous
> + * call returned.
> + * type - the device type string to match against.
> + * compat - the string to match to one of the tokens in the
> + * "compatible" list.
> + */
> +int fdt_find_compatible_node(const void *fdt, int nodeoffset,
> + const char *type, const char *compat)
> +{
> + int offset;
> +
> + offset = fdt_find_node_by_type(fdt, nodeoffset, type);
> + if (offset < 0 || fdt_node_is_compatible(fdt, offset, compat))
> + return offset;
> +
> + return -FDT_ERR_NOTFOUND;
> +}
> +
> +/*
> * Return the node offset of the node specified by:
> * parentoffset - starting place (0 to start at the root)
> * name - name being searched for
> @@ -184,7 +323,6 @@ struct fdt_property *fdt_get_property(const void *fdt,
> int level = 0;
> uint32_t tag;
> struct fdt_property *prop;
> - int namestroff;
> int offset, nextoffset;
> int err;
>
> @@ -224,24 +362,11 @@ struct fdt_property *fdt_get_property(const void *fdt,
> if (level != 0)
> continue;
>
> - err = -FDT_ERR_BADSTRUCTURE;
> - prop = fdt_offset_ptr_typed(fdt, offset, prop);
> - if (! prop)
> - goto fail;
> - namestroff = fdt32_to_cpu(prop->nameoff);
> - if (streq(fdt_string(fdt, namestroff), name)) {
> - /* Found it! */
> - int len = fdt32_to_cpu(prop->len);
> - prop = fdt_offset_ptr(fdt, offset,
> - sizeof(*prop)+len);
> - if (! prop)
> - goto fail;
> -
> - if (lenp)
> - *lenp = len;
> -
> + err = prop_name_eq(fdt, offset, name, &prop, lenp);
> + if (err > 0)
> return prop;
> - }
> + else if (err < 0)
> + goto fail;
> break;
>
> case FDT_NOP:
>
>
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