OF: import address related functions from Linux OF API

This imports drivers/of/address.c from Linux with some minor modifications.
of_translate_address is not yet enabled and PCI and ISA related bus translations
have not been imported. Also, a corresponding include header is created with
prototypes and non-OF function stubs.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 431 insertions, 0 deletions

diff --git a/drivers/of/address.c b/drivers/of/address.c
new file mode 100644
index 0000000000..3e5387a67a
--- /dev/null
+++ b/drivers/of/address.c
@@ -0,0 +1,431 @@
+/*
+ * address.c - address related devicetree functions
+ *
+ * Copyright (c) 2012 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
+ *
+ * based on Linux devicetree support
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#include <common.h>
+#include <of.h>
+#include <of_address.h>
+
+/* Max address size we deal with */
+#define OF_MAX_ADDR_CELLS	4
+#define OF_CHECK_ADDR_COUNT(na)	((na) > 0 && (na) <= OF_MAX_ADDR_CELLS)
+#define OF_CHECK_COUNTS(na, ns)	(OF_CHECK_ADDR_COUNT(na) && (ns) > 0)
+
+/* Debug utility */
+#ifdef DEBUG
+static void of_dump_addr(const char *s, const __be32 *addr, int na)
+{
+	printk(KERN_DEBUG "%s", s);
+	while (na--)
+		printk(" %08x", be32_to_cpu(*(addr++)));
+	printk("\n");
+}
+#else
+static void of_dump_addr(const char *s, const __be32 *addr, int na) { }
+#endif
+
+/* Callbacks for bus specific translators */
+struct of_bus {
+	const char	*name;
+	const char	*addresses;
+	int		(*match)(struct device_node *parent);
+	void		(*count_cells)(struct device_node *child,
+				       int *addrc, int *sizec);
+	u64		(*map)(__be32 *addr, const __be32 *range,
+				int na, int ns, int pna);
+	int		(*translate)(__be32 *addr, u64 offset, int na);
+	unsigned int	(*get_flags)(const __be32 *addr);
+};
+
+/*
+ * Default translator (generic bus)
+ */
+
+static void of_bus_default_count_cells(struct device_node *dev,
+				       int *addrc, int *sizec)
+{
+	if (addrc)
+		*addrc = of_n_addr_cells(dev);
+	if (sizec)
+		*sizec = of_n_size_cells(dev);
+}
+
+static u64 of_bus_default_map(__be32 *addr, const __be32 *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);
+
+	pr_debug("OF: default map, cp=%llx, s=%llx, da=%llx\n",
+		 (unsigned long long)cp, (unsigned long long)s,
+		 (unsigned long long)da);
+
+	/*
+	 * If the number of address cells is larger than 2 we assume the
+	 * mapping doesn't specify a physical address. Rather, the address
+	 * specifies an identifier that must match exactly.
+	 */
+	if (na > 2 && memcmp(range, addr, na * 4) != 0)
+		return OF_BAD_ADDR;
+
+	if (da < cp || da >= (cp + s))
+		return OF_BAD_ADDR;
+	return da - cp;
+}
+
+static int of_bus_default_translate(__be32 *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_be32(a >> 32);
+	addr[na - 1] = cpu_to_be32(a & 0xffffffffu);
+
+	return 0;
+}
+
+static unsigned int of_bus_default_get_flags(const __be32 *addr)
+{
+	return IORESOURCE_MEM;
+}
+
+/*
+ * Array of bus specific translators
+ */
+
+static struct of_bus of_busses[] = {
+	/* Default */
+	{
+		.name = "default",
+		.addresses = "reg",
+		.match = NULL,
+		.count_cells = of_bus_default_count_cells,
+		.map = of_bus_default_map,
+		.translate = of_bus_default_translate,
+		.get_flags = of_bus_default_get_flags,
+	},
+};
+
+static struct of_bus *of_match_bus(struct device_node *np)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(of_busses); i++)
+		if (!of_busses[i].match || of_busses[i].match(np))
+			return &of_busses[i];
+	BUG();
+	return NULL;
+}
+
+static int of_translate_one(struct device_node *parent, struct of_bus *bus,
+			    struct of_bus *pbus, __be32 *addr,
+			    int na, int ns, int pna, const char *rprop)
+{
+	const __be32 *ranges;
+	unsigned 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.
+	 *
+	 * As far as we know, this damage only exists on Apple machines, so
+	 * This code is only enabled on powerpc. --gcl
+	 */
+	ranges = of_get_property(parent, rprop, &rlen);
+#if !defined(CONFIG_PPC)
+	if (ranges == NULL) {
+		pr_err("OF: no ranges; cannot translate\n");
+		return 1;
+	}
+#endif /* !defined(CONFIG_PPC) */
+	if (ranges == NULL || rlen == 0) {
+		offset = of_read_number(addr, na);
+		memset(addr, 0, pna * 4);
+		pr_debug("OF: empty ranges; 1:1 translation\n");
+		goto finish;
+	}
+
+	pr_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) {
+		pr_debug("OF: not found !\n");
+		return 1;
+	}
+	memcpy(addr, ranges + na, 4 * pna);
+
+ finish:
+	of_dump_addr("OF: parent translation for:", addr, pna);
+	pr_debug("OF: with offset: %llx\n", (unsigned long long)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(struct device_node *dev,
+				  const __be32 *in_addr, const char *rprop)
+{
+	struct device_node *parent = NULL;
+	struct of_bus *bus, *pbus;
+	__be32 addr[OF_MAX_ADDR_CELLS];
+	int na, ns, pna, pns;
+	u64 result = OF_BAD_ADDR;
+
+	pr_debug("OF: ** translation for device %s **\n", dev->full_name);
+
+	/* Get parent & match bus type */
+	parent = of_get_parent(dev);
+	if (parent == NULL)
+		return OF_BAD_ADDR;
+	bus = of_match_bus(parent);
+
+	/* Count address cells & copy address locally */
+	bus->count_cells(dev, &na, &ns);
+	if (!OF_CHECK_COUNTS(na, ns)) {
+		printk(KERN_ERR "prom_parse: Bad cell count for %s\n",
+		       dev->full_name);
+		return OF_BAD_ADDR;
+	}
+	memcpy(addr, in_addr, na * 4);
+
+	pr_debug("OF: bus is %s (na=%d, ns=%d) on %s\n",
+	    bus->name, na, ns, parent->full_name);
+	of_dump_addr("OF: translating address:", addr, na);
+
+	/* Translate */
+	for (;;) {
+		/* Switch to parent bus */
+		dev = parent;
+		parent = of_get_parent(dev);
+
+		/* If root, we have finished */
+		if (parent == NULL) {
+			pr_debug("OF: reached root node\n");
+			result = of_read_number(addr, na);
+			break;
+		}
+
+		/* Get new parent bus and counts */
+		pbus = of_match_bus(parent);
+		pbus->count_cells(dev, &pna, &pns);
+		if (!OF_CHECK_COUNTS(pna, pns)) {
+			printk(KERN_ERR "prom_parse: Bad cell count for %s\n",
+			       dev->full_name);
+			break;
+		}
+
+		pr_debug("OF: parent bus is %s (na=%d, ns=%d) on %s\n",
+		    pbus->name, pna, pns, parent->full_name);
+
+		/* Apply bus translation */
+		if (of_translate_one(dev, 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);
+	}
+
+	return result;
+}
+
+u64 of_translate_dma_address(struct device_node *dev, const __be32 *in_addr)
+{
+	return __of_translate_address(dev, in_addr, "dma-ranges");
+}
+EXPORT_SYMBOL(of_translate_dma_address);
+
+bool of_can_translate_address(struct device_node *dev)
+{
+	struct device_node *parent;
+	struct of_bus *bus;
+	int na, ns;
+
+	parent = of_get_parent(dev);
+	if (parent == NULL)
+		return false;
+
+	bus = of_match_bus(parent);
+	bus->count_cells(dev, &na, &ns);
+
+	return OF_CHECK_COUNTS(na, ns);
+}
+EXPORT_SYMBOL(of_can_translate_address);
+
+const __be32 *of_get_address(struct device_node *dev, int index, u64 *size,
+		    unsigned int *flags)
+{
+	const __be32 *prop;
+	unsigned int psize;
+	struct device_node *parent;
+	struct of_bus *bus;
+	int onesize, i, na, ns;
+
+	/* Get parent & match bus type */
+	parent = of_get_parent(dev);
+	if (parent == NULL)
+		return NULL;
+	bus = of_match_bus(parent);
+	bus->count_cells(dev, &na, &ns);
+	if (!OF_CHECK_ADDR_COUNT(na))
+		return NULL;
+
+	/* Get "reg" or "assigned-addresses" property */
+	prop = of_get_property(dev, bus->addresses, &psize);
+	if (prop == NULL)
+		return NULL;
+	psize /= 4;
+
+	onesize = na + ns;
+	for (i = 0; psize >= onesize; psize -= onesize, prop += onesize, i++)
+		if (i == index) {
+			if (size)
+				*size = of_read_number(prop + na, ns);
+			if (flags)
+				*flags = bus->get_flags(prop);
+			return prop;
+		}
+	return NULL;
+}
+EXPORT_SYMBOL(of_get_address);
+
+static int __of_address_to_resource(struct device_node *dev,
+		const __be32 *addrp, u64 size, unsigned int flags,
+		const char *name, struct resource *r)
+{
+	u64 taddr;
+
+	if ((flags & (IORESOURCE_IO | IORESOURCE_MEM)) == 0)
+		return -EINVAL;
+	taddr = of_translate_address(dev, addrp);
+	if (taddr == OF_BAD_ADDR)
+		return -EINVAL;
+	memset(r, 0, sizeof(struct resource));
+	if (flags & IORESOURCE_IO) {
+		unsigned long port;
+		port = pci_address_to_pio(taddr);
+		if (port == (unsigned long)-1)
+			return -EINVAL;
+		r->start = port;
+		r->end = port + size - 1;
+	} else {
+		r->start = taddr;
+		r->end = taddr + size - 1;
+	}
+	r->flags = flags;
+	r->name = name ? name : dev->full_name;
+
+	return 0;
+}
+
+/**
+ * of_address_to_resource - Translate device tree address and return as resource
+ *
+ * Note that if your address is a PIO address, the conversion will fail if
+ * the physical address can't be internally converted to an IO token with
+ * pci_address_to_pio(), that is because it's either called to early or it
+ * can't be matched to any host bridge IO space
+ */
+int of_address_to_resource(struct device_node *dev, int index,
+			   struct resource *r)
+{
+	const __be32	*addrp;
+	u64		size;
+	unsigned int	flags;
+	const char	*name = NULL;
+
+	addrp = of_get_address(dev, index, &size, &flags);
+	if (addrp == NULL)
+		return -EINVAL;
+
+	/* Get optional "reg-names" property to add a name to a resource */
+	of_property_read_string_index(dev, "reg-names",	index, &name);
+
+	return __of_address_to_resource(dev, addrp, size, flags, name, r);
+}
+EXPORT_SYMBOL_GPL(of_address_to_resource);
+
+struct device_node *of_find_matching_node_by_address(struct device_node *from,
+					const struct of_device_id *matches,
+					u64 base_address)
+{
+	struct device_node *dn = of_find_matching_node(from, matches);
+	struct resource res;
+
+	while (dn) {
+		if (of_address_to_resource(dn, 0, &res))
+			continue;
+		if (res.start == base_address)
+			return dn;
+		dn = of_find_matching_node(dn, matches);
+	}
+
+	return NULL;
+}
+
+/**
+ * of_iomap - Maps the memory mapped IO for a given device_node
+ * @device:	the device whose io range will be mapped
+ * @index:	index of the io range
+ *
+ * Returns a pointer to the mapped memory
+ */
+void __iomem *of_iomap(struct device_node *np, int index)
+{
+	struct resource res;
+
+	if (of_address_to_resource(np, index, &res))
+		return NULL;
+
+	return IOMEM(res.start);
+}
+EXPORT_SYMBOL(of_iomap);