Commit 9706a36e authored by Stephen Neuendorffer's avatar Stephen Neuendorffer Committed by Grant Likely
Browse files

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: default avatarStephen Neuendorffer <stephen.neuendorffer@xilinx.com>
Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent e6ce1324

drivers/of/fdt.c

+79 −54
Original line number Diff line number Diff line
@@ -22,6 +22,82 @@ 


#include <asm/page.h>



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;

include/linux/of_fdt.h

+11 −0
Original line number Diff line number Diff line
@@ -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;

CRA Git | Maintained and supported by SUSTech CRA and CCSE