From 9706a36e35c4ce04f28a62cfe1205b4e3b0dd13c Mon Sep 17 00:00:00 2001 From: Stephen Neuendorffer Date: Thu, 18 Nov 2010 15:54:59 -0800 Subject: [PATCH] of/flattree: Add non-boottime device tree functions In preparation for providing run-time handling of device trees, factor out some of the basic functions so that they take an arbitrary blob, rather than relying on the single boot-time tree. V2: - functions have of_fdt_* names - removed find_flat_dt_string - blob argument is first Signed-off-by: Stephen Neuendorffer Signed-off-by: Grant Likely --- drivers/of/fdt.c | 133 ++++++++++++++++++++++++----------------- include/linux/of_fdt.h | 11 ++++ 2 files changed, 90 insertions(+), 54 deletions(-) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 2ebacf14e7de..10eab21076ea 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -22,6 +22,82 @@ #include +char *of_fdt_get_string(struct boot_param_header *blob, u32 offset) +{ + return ((char *)blob) + + be32_to_cpu(blob->off_dt_strings) + offset; +} + +/** + * of_fdt_get_property - Given a node in the given flat blob, return + * the property ptr + */ +void *of_fdt_get_property(struct boot_param_header *blob, + unsigned long node, const char *name, + unsigned long *size) +{ + unsigned long p = node; + + do { + u32 tag = be32_to_cpup((__be32 *)p); + u32 sz, noff; + const char *nstr; + + p += 4; + if (tag == OF_DT_NOP) + continue; + if (tag != OF_DT_PROP) + return NULL; + + sz = be32_to_cpup((__be32 *)p); + noff = be32_to_cpup((__be32 *)(p + 4)); + p += 8; + if (be32_to_cpu(blob->version) < 0x10) + p = ALIGN(p, sz >= 8 ? 8 : 4); + + nstr = of_fdt_get_string(blob, noff); + if (nstr == NULL) { + pr_warning("Can't find property index name !\n"); + return NULL; + } + if (strcmp(name, nstr) == 0) { + if (size) + *size = sz; + return (void *)p; + } + p += sz; + p = ALIGN(p, 4); + } while (1); +} + +/** + * of_fdt_is_compatible - Return true if given node from the given blob has + * compat in its compatible list + * @blob: A device tree blob + * @node: node to test + * @compat: compatible string to compare with compatible list. + */ +int of_fdt_is_compatible(struct boot_param_header *blob, + unsigned long node, const char *compat) +{ + const char *cp; + unsigned long cplen, l; + + cp = of_fdt_get_property(blob, node, "compatible", &cplen); + if (cp == NULL) + return 0; + while (cplen > 0) { + if (of_compat_cmp(cp, compat, strlen(compat)) == 0) + return 1; + l = strlen(cp) + 1; + cp += l; + cplen -= l; + } + + return 0; +} + +/* Everything below here references initial_boot_params directly. */ int __initdata dt_root_addr_cells; int __initdata dt_root_size_cells; @@ -29,12 +105,6 @@ struct boot_param_header *initial_boot_params; #ifdef CONFIG_OF_EARLY_FLATTREE -char *find_flat_dt_string(u32 offset) -{ - return ((char *)initial_boot_params) + - be32_to_cpu(initial_boot_params->off_dt_strings) + offset; -} - /** * of_scan_flat_dt - scan flattened tree blob and call callback on each. * @it: callback function @@ -123,38 +193,7 @@ unsigned long __init of_get_flat_dt_root(void) void *__init of_get_flat_dt_prop(unsigned long node, const char *name, unsigned long *size) { - unsigned long p = node; - - do { - u32 tag = be32_to_cpup((__be32 *)p); - u32 sz, noff; - const char *nstr; - - p += 4; - if (tag == OF_DT_NOP) - continue; - if (tag != OF_DT_PROP) - return NULL; - - sz = be32_to_cpup((__be32 *)p); - noff = be32_to_cpup((__be32 *)(p + 4)); - p += 8; - if (be32_to_cpu(initial_boot_params->version) < 0x10) - p = ALIGN(p, sz >= 8 ? 8 : 4); - - nstr = find_flat_dt_string(noff); - if (nstr == NULL) { - pr_warning("Can't find property index name !\n"); - return NULL; - } - if (strcmp(name, nstr) == 0) { - if (size) - *size = sz; - return (void *)p; - } - p += sz; - p = ALIGN(p, 4); - } while (1); + return of_fdt_get_property(initial_boot_params, node, name, size); } /** @@ -164,21 +203,7 @@ void *__init of_get_flat_dt_prop(unsigned long node, const char *name, */ int __init of_flat_dt_is_compatible(unsigned long node, const char *compat) { - const char *cp; - unsigned long cplen, l; - - cp = of_get_flat_dt_prop(node, "compatible", &cplen); - if (cp == NULL) - return 0; - while (cplen > 0) { - if (of_compat_cmp(cp, compat, strlen(compat)) == 0) - return 1; - l = strlen(cp) + 1; - cp += l; - cplen -= l; - } - - return 0; + return of_fdt_is_compatible(initial_boot_params, node, compat); } static void *__init unflatten_dt_alloc(unsigned long *mem, unsigned long size, @@ -303,7 +328,7 @@ unsigned long __init unflatten_dt_node(unsigned long mem, if (be32_to_cpu(initial_boot_params->version) < 0x10) *p = ALIGN(*p, sz >= 8 ? 8 : 4); - pname = find_flat_dt_string(noff); + pname = of_fdt_get_string(initial_boot_params, noff); if (pname == NULL) { pr_info("Can't find property name in list !\n"); break; diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h index 7bbf5b328438..70c5b736f0a3 100644 --- a/include/linux/of_fdt.h +++ b/include/linux/of_fdt.h @@ -58,6 +58,17 @@ struct boot_param_header { }; #if defined(CONFIG_OF_FLATTREE) + +/* For scanning an arbitrary device-tree at any time */ +extern char *of_fdt_get_string(struct boot_param_header *blob, u32 offset); +extern void *of_fdt_get_property(struct boot_param_header *blob, + unsigned long node, + const char *name, + unsigned long *size); +extern int of_fdt_is_compatible(struct boot_param_header *blob, + unsigned long node, + const char *compat); + /* TBD: Temporary export of fdt globals - remove when code fully merged */ extern int __initdata dt_root_addr_cells; extern int __initdata dt_root_size_cells; -- GitLab