fdt_support.c

	const char	*name;
	const char	*addresses;
	int		(*match)(const void *blob, int parentoffset);
	void		(*count_cells)(const void *blob, int parentoffset,
				int *addrc, int *sizec);
	u64		(*map)(fdt32_t *addr, const fdt32_t *range,
				int na, int ns, int pna);
	int		(*translate)(fdt32_t *addr, u64 offset, int na);
};

/* Default translator (generic bus) */
void of_bus_default_count_cells(const void *blob, int parentoffset,
					int *addrc, int *sizec)
{
	const fdt32_t *prop;

	if (addrc)
		*addrc = fdt_address_cells(blob, parentoffset);

	if (sizec) {
		prop = fdt_getprop(blob, parentoffset, "#size-cells", NULL);
		if (prop)
			*sizec = be32_to_cpup(prop);
		else
			*sizec = 1;
	}
}

static u64 of_bus_default_map(fdt32_t *addr, const fdt32_t *range,
		int na, int ns, int pna)
{
	u64 cp, s, da;

	cp = of_read_number(range, na);
	s  = of_read_number(range + na + pna, ns);
	da = of_read_number(addr, na);

	debug("OF: default map, cp=%" PRIu64 ", s=%" PRIu64
	      ", da=%" PRIu64 "\n", cp, s, da);

	if (da < cp || da >= (cp + s))
		return OF_BAD_ADDR;
	return da - cp;
}

static int of_bus_default_translate(fdt32_t *addr, u64 offset, int na)
{
	u64 a = of_read_number(addr, na);
	memset(addr, 0, na * 4);
	a += offset;
	if (na > 1)
		addr[na - 2] = cpu_to_fdt32(a >> 32);
	addr[na - 1] = cpu_to_fdt32(a & 0xffffffffu);

	return 0;
}

#ifdef CONFIG_OF_ISA_BUS

/* ISA bus translator */
static int of_bus_isa_match(const void *blob, int parentoffset)
{
	const char *name;

	name = fdt_get_name(blob, parentoffset, NULL);
	if (!name)
		return 0;

	return !strcmp(name, "isa");
}

static void of_bus_isa_count_cells(const void *blob, int parentoffset,
				   int *addrc, int *sizec)
{
	if (addrc)
		*addrc = 2;
	if (sizec)
		*sizec = 1;
}

static u64 of_bus_isa_map(fdt32_t *addr, const fdt32_t *range,
			  int na, int ns, int pna)
{
	u64 cp, s, da;

	/* Check address type match */
	if ((addr[0] ^ range[0]) & cpu_to_be32(1))
		return OF_BAD_ADDR;

	cp = of_read_number(range + 1, na - 1);
	s  = of_read_number(range + na + pna, ns);
	da = of_read_number(addr + 1, na - 1);

	debug("OF: ISA map, cp=%" PRIu64 ", s=%" PRIu64
	      ", da=%" PRIu64 "\n", cp, s, da);

	if (da < cp || da >= (cp + s))
		return OF_BAD_ADDR;
	return da - cp;
}

static int of_bus_isa_translate(fdt32_t *addr, u64 offset, int na)
{
	return of_bus_default_translate(addr + 1, offset, na - 1);
}

#endif /* CONFIG_OF_ISA_BUS */

/* Array of bus specific translators */
static struct of_bus of_busses[] = {
#ifdef CONFIG_OF_ISA_BUS
	/* ISA */
	{
		.name = "isa",
		.addresses = "reg",
		.match = of_bus_isa_match,
		.count_cells = of_bus_isa_count_cells,
		.map = of_bus_isa_map,
		.translate = of_bus_isa_translate,
	},
#endif /* CONFIG_OF_ISA_BUS */
	/* Default */
	{
		.name = "default",
		.addresses = "reg",
		.count_cells = of_bus_default_count_cells,
		.map = of_bus_default_map,
		.translate = of_bus_default_translate,
	},
};

static struct of_bus *of_match_bus(const void *blob, int parentoffset)
{
	struct of_bus *bus;

	if (ARRAY_SIZE(of_busses) == 1)
		return of_busses;

	for (bus = of_busses; bus; bus++) {
		if (!bus->match || bus->match(blob, parentoffset))
			return bus;
	}

	/*
	 * We should always have matched the default bus at least, since
	 * it has a NULL match field. If we didn't then it somehow isn't
	 * in the of_busses array or something equally catastrophic has
	 * gone wrong.
	 */
	assert(0);
	return NULL;
}

static int of_translate_one(const void *blob, int parent, struct of_bus *bus,
			    struct of_bus *pbus, fdt32_t *addr,
			    int na, int ns, int pna, const char *rprop)
{
	const fdt32_t *ranges;
	int rlen;
	int rone;
	u64 offset = OF_BAD_ADDR;

	/* Normally, an absence of a "ranges" property means we are
	 * crossing a non-translatable boundary, and thus the addresses
	 * below the current not cannot be converted to CPU physical ones.
	 * Unfortunately, while this is very clear in the spec, it's not
	 * what Apple understood, and they do have things like /uni-n or
	 * /ht nodes with no "ranges" property and a lot of perfectly
	 * useable mapped devices below them. Thus we treat the absence of
	 * "ranges" as equivalent to an empty "ranges" property which means
	 * a 1:1 translation at that level. It's up to the caller not to try
	 * to translate addresses that aren't supposed to be translated in
	 * the first place. --BenH.
	 */
	ranges = fdt_getprop(blob, parent, rprop, &rlen);
	if (ranges == NULL || rlen == 0) {
		offset = of_read_number(addr, na);
		memset(addr, 0, pna * 4);
		debug("OF: no ranges, 1:1 translation\n");
		goto finish;
	}

	debug("OF: walking ranges...\n");

	/* Now walk through the ranges */
	rlen /= 4;
	rone = na + pna + ns;
	for (; rlen >= rone; rlen -= rone, ranges += rone) {
		offset = bus->map(addr, ranges, na, ns, pna);
		if (offset != OF_BAD_ADDR)
			break;
	}
	if (offset == OF_BAD_ADDR) {
		debug("OF: not found !\n");
		return 1;
	}
	memcpy(addr, ranges + na, 4 * pna);

 finish:
	of_dump_addr("OF: parent translation for:", addr, pna);
	debug("OF: with offset: %" PRIu64 "\n", offset);

	/* Translate it into parent bus space */
	return pbus->translate(addr, offset, pna);
}

/*
 * Translate an address from the device-tree into a CPU physical address,
 * this walks up the tree and applies the various bus mappings on the
 * way.
 *
 * Note: We consider that crossing any level with #size-cells == 0 to mean
 * that translation is impossible (that is we are not dealing with a value
 * that can be mapped to a cpu physical address). This is not really specified
 * that way, but this is traditionally the way IBM at least do things
 */
static u64 __of_translate_address(const void *blob, int node_offset,
				  const fdt32_t *in_addr, const char *rprop)
{
	int parent;
	struct of_bus *bus, *pbus;
	fdt32_t addr[OF_MAX_ADDR_CELLS];
	int na, ns, pna, pns;
	u64 result = OF_BAD_ADDR;

	debug("OF: ** translation for device %s **\n",
		fdt_get_name(blob, node_offset, NULL));

	/* Get parent & match bus type */
	parent = fdt_parent_offset(blob, node_offset);
	if (parent < 0)
		goto bail;
	bus = of_match_bus(blob, parent);

	/* Cound address cells & copy address locally */
	bus->count_cells(blob, parent, &na, &ns);
	if (!OF_CHECK_COUNTS(na, ns)) {
		printf("%s: Bad cell count for %s\n", __FUNCTION__,
		       fdt_get_name(blob, node_offset, NULL));
		goto bail;
	}
	memcpy(addr, in_addr, na * 4);

	debug("OF: bus is %s (na=%d, ns=%d) on %s\n",
	    bus->name, na, ns, fdt_get_name(blob, parent, NULL));
	of_dump_addr("OF: translating address:", addr, na);

	/* Translate */
	for (;;) {
		/* Switch to parent bus */
		node_offset = parent;
		parent = fdt_parent_offset(blob, node_offset);

		/* If root, we have finished */
		if (parent < 0) {
			debug("OF: reached root node\n");
			result = of_read_number(addr, na);
			break;
		}

		/* Get new parent bus and counts */
		pbus = of_match_bus(blob, parent);
		pbus->count_cells(blob, parent, &pna, &pns);
		if (!OF_CHECK_COUNTS(pna, pns)) {
			printf("%s: Bad cell count for %s\n", __FUNCTION__,
				fdt_get_name(blob, node_offset, NULL));
			break;
		}

		debug("OF: parent bus is %s (na=%d, ns=%d) on %s\n",
		    pbus->name, pna, pns, fdt_get_name(blob, parent, NULL));

		/* Apply bus translation */
		if (of_translate_one(blob, node_offset, bus, pbus,
					addr, na, ns, pna, rprop))
			break;

		/* Complete the move up one level */
		na = pna;
		ns = pns;
		bus = pbus;

		of_dump_addr("OF: one level translation:", addr, na);
	}
 bail:

	return result;
}

u64 fdt_translate_address(const void *blob, int node_offset,
			  const fdt32_t *in_addr)
{
	return __of_translate_address(blob, node_offset, in_addr, "ranges");
}

/**
 * fdt_node_offset_by_compat_reg: Find a node that matches compatiable and
 * who's reg property matches a physical cpu address
 *
 * @blob: ptr to device tree
 * @compat: compatiable string to match
 * @compat_off: property name
 *
 */
int fdt_node_offset_by_compat_reg(void *blob, const char *compat,
					phys_addr_t compat_off)
{
	int len, off = fdt_node_offset_by_compatible(blob, -1, compat);
	while (off != -FDT_ERR_NOTFOUND) {
		const fdt32_t *reg = fdt_getprop(blob, off, "reg", &len);
		if (reg) {
			if (compat_off == fdt_translate_address(blob, off, reg))
				return off;
		}
		off = fdt_node_offset_by_compatible(blob, off, compat);
	}

	return -FDT_ERR_NOTFOUND;
}

/**
 * fdt_alloc_phandle: Return next free phandle value
 *
 * @blob: ptr to device tree
 */
int fdt_alloc_phandle(void *blob)
{
	int offset;
	uint32_t phandle = 0;

	for (offset = fdt_next_node(blob, -1, NULL); offset >= 0;
	     offset = fdt_next_node(blob, offset, NULL)) {
		phandle = max(phandle, fdt_get_phandle(blob, offset));
	}

	return phandle + 1;
}

/*
 * fdt_set_phandle: Create a phandle property for the given node
 *
 * @fdt: ptr to device tree
 * @nodeoffset: node to update
 * @phandle: phandle value to set (must be unique)
 */
int fdt_set_phandle(void *fdt, int nodeoffset, uint32_t phandle)
{
	int ret;

#ifdef DEBUG
	int off = fdt_node_offset_by_phandle(fdt, phandle);

	if ((off >= 0) && (off != nodeoffset)) {
		char buf[64];

		fdt_get_path(fdt, nodeoffset, buf, sizeof(buf));
		printf("Trying to update node %s with phandle %u ",
		       buf, phandle);

		fdt_get_path(fdt, off, buf, sizeof(buf));
		printf("that already exists in node %s.\n", buf);
		return -FDT_ERR_BADPHANDLE;
	}
#endif

	ret = fdt_setprop_cell(fdt, nodeoffset, "phandle", phandle);
	if (ret < 0)
		return ret;

	/*
	 * For now, also set the deprecated "linux,phandle" property, so that we
	 * don't break older kernels.
	 */
	ret = fdt_setprop_cell(fdt, nodeoffset, "linux,phandle", phandle);

	return ret;
}

/*
 * fdt_create_phandle: Create a phandle property for the given node
 *
 * @fdt: ptr to device tree
 * @nodeoffset: node to update
 */
unsigned int fdt_create_phandle(void *fdt, int nodeoffset)
{
	/* see if there is a phandle already */
	int phandle = fdt_get_phandle(fdt, nodeoffset);

	/* if we got 0, means no phandle so create one */
	if (phandle == 0) {
		int ret;

		phandle = fdt_alloc_phandle(fdt);
		ret = fdt_set_phandle(fdt, nodeoffset, phandle);
		if (ret < 0) {
			printf("Can't set phandle %u: %s\n", phandle,
			       fdt_strerror(ret));
			return 0;
		}
	}

	return phandle;
}

/*
 * fdt_set_node_status: Set status for the given node
 *
 * @fdt: ptr to device tree
 * @nodeoffset: node to update
 * @status: FDT_STATUS_OKAY, FDT_STATUS_DISABLED,
 *	    FDT_STATUS_FAIL, FDT_STATUS_FAIL_ERROR_CODE
 * @error_code: optional, only used if status is FDT_STATUS_FAIL_ERROR_CODE
 */
int fdt_set_node_status(void *fdt, int nodeoffset,
			enum fdt_status status, unsigned int error_code)
{
	char buf[16];
	int ret = 0;

	if (nodeoffset < 0)
		return nodeoffset;

	switch (status) {
	case FDT_STATUS_OKAY:
		ret = fdt_setprop_string(fdt, nodeoffset, "status", "okay");
		break;
	case FDT_STATUS_DISABLED:
		ret = fdt_setprop_string(fdt, nodeoffset, "status", "disabled");
		break;
	case FDT_STATUS_FAIL:
		ret = fdt_setprop_string(fdt, nodeoffset, "status", "fail");
		break;
	case FDT_STATUS_FAIL_ERROR_CODE:
		sprintf(buf, "fail-%d", error_code);
		ret = fdt_setprop_string(fdt, nodeoffset, "status", buf);
		break;
	default:
		printf("Invalid fdt status: %x\n", status);
		ret = -1;
		break;
	}

	return ret;
}

/*
 * fdt_set_status_by_alias: Set status for the given node given an alias
 *
 * @fdt: ptr to device tree
 * @alias: alias of node to update
 * @status: FDT_STATUS_OKAY, FDT_STATUS_DISABLED,
 *	    FDT_STATUS_FAIL, FDT_STATUS_FAIL_ERROR_CODE
 * @error_code: optional, only used if status is FDT_STATUS_FAIL_ERROR_CODE
 */
int fdt_set_status_by_alias(void *fdt, const char* alias,
			    enum fdt_status status, unsigned int error_code)
{
	int offset = fdt_path_offset(fdt, alias);

	return fdt_set_node_status(fdt, offset, status, error_code);
}

#if defined(CONFIG_VIDEO) || defined(CONFIG_LCD)
int fdt_add_edid(void *blob, const char *compat, unsigned char *edid_buf)
{
	int noff;
	int ret;

	noff = fdt_node_offset_by_compatible(blob, -1, compat);
	if (noff != -FDT_ERR_NOTFOUND) {
		debug("%s: %s\n", fdt_get_name(blob, noff, 0), compat);
add_edid:
		ret = fdt_setprop(blob, noff, "edid", edid_buf, 128);
		if (ret == -FDT_ERR_NOSPACE) {
			ret = fdt_increase_size(blob, 512);
			if (!ret)
				goto add_edid;
			else
				goto err_size;
		} else if (ret < 0) {
			printf("Can't add property: %s\n", fdt_strerror(ret));
			return ret;
		}
	}
	return 0;
err_size:
	printf("Can't increase blob size: %s\n", fdt_strerror(ret));
	return ret;
}
#endif

/*
 * Verify the physical address of device tree node for a given alias
 *
 * This function locates the device tree node of a given alias, and then
 * verifies that the physical address of that device matches the given
 * parameter.  It displays a message if there is a mismatch.
 *
 * Returns 1 on success, 0 on failure
 */
int fdt_verify_alias_address(void *fdt, int anode, const char *alias, u64 addr)
{
	const char *path;
	const fdt32_t *reg;
	int node, len;
	u64 dt_addr;

	path = fdt_getprop(fdt, anode, alias, NULL);
	if (!path) {
		/* If there's no such alias, then it's not a failure */
		return 1;
	}

	node = fdt_path_offset(fdt, path);
	if (node < 0) {
		printf("Warning: device tree alias '%s' points to invalid "
		       "node %s.\n", alias, path);
		return 0;
	}

	reg = fdt_getprop(fdt, node, "reg", &len);
	if (!reg) {
		printf("Warning: device tree node '%s' has no address.\n",
		       path);
		return 0;
	}

	dt_addr = fdt_translate_address(fdt, node, reg);
	if (addr != dt_addr) {
		printf("Warning: U-Boot configured device %s at address %"
		       PRIx64 ",\n but the device tree has it address %"
		       PRIx64 ".\n", alias, addr, dt_addr);
		return 0;
	}

	return 1;
}

/*
 * Returns the base address of an SOC or PCI node
 */
u64 fdt_get_base_address(void *fdt, int node)
{
	int size;
	u32 naddr;
	const fdt32_t *prop;

	naddr = fdt_address_cells(fdt, node);

	prop = fdt_getprop(fdt, node, "ranges", &size);

	return prop ? fdt_translate_address(fdt, node, prop + naddr) : 0;
}

/*
 * Read a property of size <prop_len>. Currently only supports 1 or 2 cells.
 */
static int fdt_read_prop(const fdt32_t *prop, int prop_len, int cell_off,
			 uint64_t *val, int cells)
{
	const fdt32_t *prop32 = &prop[cell_off];
	const fdt64_t *prop64 = (const fdt64_t *)&prop[cell_off];

	if ((cell_off + cells) > prop_len)
		return -FDT_ERR_NOSPACE;

	switch (cells) {
	case 1:
		*val = fdt32_to_cpu(*prop32);
		break;
	case 2:
		*val = fdt64_to_cpu(*prop64);
		break;
	default:
		return -FDT_ERR_NOSPACE;
	}

	return 0;
}

/**
 * fdt_read_range - Read a node's n'th range property
 *
 * @fdt: ptr to device tree
 * @node: offset of node
 * @n: range index
 * @child_addr: pointer to storage for the "child address" field
 * @addr: pointer to storage for the CPU view translated physical start
 * @len: pointer to storage for the range length
 *
 * Convenience function that reads and interprets a specific range out of
 * a number of the "ranges" property array.
 */
int fdt_read_range(void *fdt, int node, int n, uint64_t *child_addr,
		   uint64_t *addr, uint64_t *len)
{
	int pnode = fdt_parent_offset(fdt, node);
	const fdt32_t *ranges;
	int pacells;
	int acells;
	int scells;
	int ranges_len;
	int cell = 0;
	int r = 0;

	/*
	 * The "ranges" property is an array of
	 * { <child address> <parent address> <size in child address space> }
	 *
	 * All 3 elements can span a diffent number of cells. Fetch their size.
	 */
	pacells = fdt_getprop_u32_default_node(fdt, pnode, 0, "#address-cells", 1);
	acells = fdt_getprop_u32_default_node(fdt, node, 0, "#address-cells", 1);
	scells = fdt_getprop_u32_default_node(fdt, node, 0, "#size-cells", 1);

	/* Now try to get the ranges property */
	ranges = fdt_getprop(fdt, node, "ranges", &ranges_len);
	if (!ranges)
		return -FDT_ERR_NOTFOUND;
	ranges_len /= sizeof(uint32_t);

	/* Jump to the n'th entry */
	cell = n * (pacells + acells + scells);

	/* Read <child address> */
	if (child_addr) {
		r = fdt_read_prop(ranges, ranges_len, cell, child_addr,
				  acells);
		if (r)
			return r;
	}
	cell += acells;

	/* Read <parent address> */
	if (addr)
		*addr = fdt_translate_address(fdt, node, ranges + cell);
	cell += pacells;

	/* Read <size in child address space> */
	if (len) {
		r = fdt_read_prop(ranges, ranges_len, cell, len, scells);
		if (r)
			return r;
	}

	return 0;
}

/**
 * fdt_setup_simplefb_node - Fill and enable a simplefb node
 *
 * @fdt: ptr to device tree
 * @node: offset of the simplefb node
 * @base_address: framebuffer base address
 * @width: width in pixels
 * @height: height in pixels
 * @stride: bytes per line
 * @format: pixel format string
 *
 * Convenience function to fill and enable a simplefb node.
 */
int fdt_setup_simplefb_node(void *fdt, int node, u64 base_address, u32 width,
			    u32 height, u32 stride, const char *format)
{
	char name[32];
	fdt32_t cells[4];
	int i, addrc, sizec, ret;

	of_bus_default_count_cells(fdt, fdt_parent_offset(fdt, node),
				   &addrc, &sizec);
	i = 0;
	if (addrc == 2)
		cells[i++] = cpu_to_fdt32(base_address >> 32);
	cells[i++] = cpu_to_fdt32(base_address);
	if (sizec == 2)
		cells[i++] = 0;
	cells[i++] = cpu_to_fdt32(height * stride);

	ret = fdt_setprop(fdt, node, "reg", cells, sizeof(cells[0]) * i);
	if (ret < 0)
		return ret;

	snprintf(name, sizeof(name), "framebuffer@%" PRIx64, base_address);
	ret = fdt_set_name(fdt, node, name);
	if (ret < 0)
		return ret;

	ret = fdt_setprop_u32(fdt, node, "width", width);
	if (ret < 0)
		return ret;

	ret = fdt_setprop_u32(fdt, node, "height", height);
	if (ret < 0)
		return ret;

	ret = fdt_setprop_u32(fdt, node, "stride", stride);
	if (ret < 0)
		return ret;

	ret = fdt_setprop_string(fdt, node, "format", format);
	if (ret < 0)
		return ret;

	ret = fdt_setprop_string(fdt, node, "status", "okay");
	if (ret < 0)
		return ret;

	return 0;
}

/*
 * Update native-mode in display-timings from display environment variable.
 * The node to update are specified by path.
 */
int fdt_fixup_display(void *blob, const char *path, const char *display)
{
	int off, toff;

	if (!display || !path)
		return -FDT_ERR_NOTFOUND;

	toff = fdt_path_offset(blob, path);
	if (toff >= 0)
		toff = fdt_subnode_offset(blob, toff, "display-timings");
	if (toff < 0)
		return toff;

	for (off = fdt_first_subnode(blob, toff);
	     off >= 0;
	     off = fdt_next_subnode(blob, off)) {
		uint32_t h = fdt_get_phandle(blob, off);
		debug("%s:0x%x\n", fdt_get_name(blob, off, NULL),
		      fdt32_to_cpu(h));
		if (strcasecmp(fdt_get_name(blob, off, NULL), display) == 0)
			return fdt_setprop_u32(blob, toff, "native-mode", h);
	}
	return toff;
}