of/irq: merge irq mapping code

Merge common irq mapping code between PowerPC and Microblaze.

This patch merges of_irq_find_parent(), of_irq_map_raw() and
of_irq_map_one().  The functions are dependent on one another, so all
three are merged in a single patch.  Other than cosmetic difference
(ie. DBG() vs. pr_debug()), the implementations are identical.

of_irq_to_resource() is also merged, but in this case the
implementations are different.  This patch drops the microblaze version
and uses the powerpc implementation unchanged.  The microblaze version
essentially open-coded irq_of_parse_and_map() which it does not need
to do.  Therefore the powerpc version is safe to adopt.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
CC: Michal Simek <monstr@monstr.eu>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Stephen Rothwell <sfr@canb.auug.org.au>

1 files changed, 301 insertions, 0 deletions

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 9b3397c..598454f 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -43,3 +43,304 @@ unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 				     oirq.size);
 }
 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
+
+/**
+ * of_irq_find_parent - Given a device node, find its interrupt parent node
+ * @child: pointer to device node
+ *
+ * Returns a pointer to the interrupt parent node, or NULL if the interrupt
+ * parent could not be determined.
+ */
+static struct device_node *of_irq_find_parent(struct device_node *child)
+{
+	struct device_node *p;
+	const phandle *parp;
+
+	if (!of_node_get(child))
+		return NULL;
+
+	do {
+		parp = of_get_property(child, "interrupt-parent", NULL);
+		if (parp == NULL)
+			p = of_get_parent(child);
+		else {
+			if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
+				p = of_node_get(of_irq_dflt_pic);
+			else
+				p = of_find_node_by_phandle(*parp);
+		}
+		of_node_put(child);
+		child = p;
+	} while (p && of_get_property(p, "#interrupt-cells", NULL) == NULL);
+
+	return p;
+}
+
+/**
+ * of_irq_map_raw - Low level interrupt tree parsing
+ * @parent:	the device interrupt parent
+ * @intspec:	interrupt specifier ("interrupts" property of the device)
+ * @ointsize:   size of the passed in interrupt specifier
+ * @addr:	address specifier (start of "reg" property of the device)
+ * @out_irq:	structure of_irq filled by this function
+ *
+ * Returns 0 on success and a negative number on error
+ *
+ * This function is a low-level interrupt tree walking function. It
+ * can be used to do a partial walk with synthetized reg and interrupts
+ * properties, for example when resolving PCI interrupts when no device
+ * node exist for the parent.
+ */
+int of_irq_map_raw(struct device_node *parent, const u32 *intspec, u32 ointsize,
+		const u32 *addr, struct of_irq *out_irq)
+{
+	struct device_node *ipar, *tnode, *old = NULL, *newpar = NULL;
+	const u32 *tmp, *imap, *imask;
+	u32 intsize = 1, addrsize, newintsize = 0, newaddrsize = 0;
+	int imaplen, match, i;
+
+	pr_debug("of_irq_map_raw: par=%s,intspec=[0x%08x 0x%08x...],ointsize=%d\n",
+	    parent->full_name, intspec[0], intspec[1], ointsize);
+
+	ipar = of_node_get(parent);
+
+	/* First get the #interrupt-cells property of the current cursor
+	 * that tells us how to interpret the passed-in intspec. If there
+	 * is none, we are nice and just walk up the tree
+	 */
+	do {
+		tmp = of_get_property(ipar, "#interrupt-cells", NULL);
+		if (tmp != NULL) {
+			intsize = *tmp;
+			break;
+		}
+		tnode = ipar;
+		ipar = of_irq_find_parent(ipar);
+		of_node_put(tnode);
+	} while (ipar);
+	if (ipar == NULL) {
+		pr_debug(" -> no parent found !\n");
+		goto fail;
+	}
+
+	pr_debug("of_irq_map_raw: ipar=%s, size=%d\n", ipar->full_name, intsize);
+
+	if (ointsize != intsize)
+		return -EINVAL;
+
+	/* Look for this #address-cells. We have to implement the old linux
+	 * trick of looking for the parent here as some device-trees rely on it
+	 */
+	old = of_node_get(ipar);
+	do {
+		tmp = of_get_property(old, "#address-cells", NULL);
+		tnode = of_get_parent(old);
+		of_node_put(old);
+		old = tnode;
+	} while (old && tmp == NULL);
+	of_node_put(old);
+	old = NULL;
+	addrsize = (tmp == NULL) ? 2 : *tmp;
+
+	pr_debug(" -> addrsize=%d\n", addrsize);
+
+	/* Now start the actual "proper" walk of the interrupt tree */
+	while (ipar != NULL) {
+		/* Now check if cursor is an interrupt-controller and if it is
+		 * then we are done
+		 */
+		if (of_get_property(ipar, "interrupt-controller", NULL) !=
+				NULL) {
+			pr_debug(" -> got it !\n");
+			memcpy(out_irq->specifier, intspec,
+			       intsize * sizeof(u32));
+			out_irq->size = intsize;
+			out_irq->controller = ipar;
+			of_node_put(old);
+			return 0;
+		}
+
+		/* Now look for an interrupt-map */
+		imap = of_get_property(ipar, "interrupt-map", &imaplen);
+		/* No interrupt map, check for an interrupt parent */
+		if (imap == NULL) {
+			pr_debug(" -> no map, getting parent\n");
+			newpar = of_irq_find_parent(ipar);
+			goto skiplevel;
+		}
+		imaplen /= sizeof(u32);
+
+		/* Look for a mask */
+		imask = of_get_property(ipar, "interrupt-map-mask", NULL);
+
+		/* If we were passed no "reg" property and we attempt to parse
+		 * an interrupt-map, then #address-cells must be 0.
+		 * Fail if it's not.
+		 */
+		if (addr == NULL && addrsize != 0) {
+			pr_debug(" -> no reg passed in when needed !\n");
+			goto fail;
+		}
+
+		/* Parse interrupt-map */
+		match = 0;
+		while (imaplen > (addrsize + intsize + 1) && !match) {
+			/* Compare specifiers */
+			match = 1;
+			for (i = 0; i < addrsize && match; ++i) {
+				u32 mask = imask ? imask[i] : 0xffffffffu;
+				match = ((addr[i] ^ imap[i]) & mask) == 0;
+			}
+			for (; i < (addrsize + intsize) && match; ++i) {
+				u32 mask = imask ? imask[i] : 0xffffffffu;
+				match =
+				   ((intspec[i-addrsize] ^ imap[i]) & mask) == 0;
+			}
+			imap += addrsize + intsize;
+			imaplen -= addrsize + intsize;
+
+			pr_debug(" -> match=%d (imaplen=%d)\n", match, imaplen);
+
+			/* Get the interrupt parent */
+			if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
+				newpar = of_node_get(of_irq_dflt_pic);
+			else
+				newpar = of_find_node_by_phandle((phandle)*imap);
+			imap++;
+			--imaplen;
+
+			/* Check if not found */
+			if (newpar == NULL) {
+				pr_debug(" -> imap parent not found !\n");
+				goto fail;
+			}
+
+			/* Get #interrupt-cells and #address-cells of new
+			 * parent
+			 */
+			tmp = of_get_property(newpar, "#interrupt-cells", NULL);
+			if (tmp == NULL) {
+				pr_debug(" -> parent lacks #interrupt-cells!\n");
+				goto fail;
+			}
+			newintsize = *tmp;
+			tmp = of_get_property(newpar, "#address-cells", NULL);
+			newaddrsize = (tmp == NULL) ? 0 : *tmp;
+
+			pr_debug(" -> newintsize=%d, newaddrsize=%d\n",
+			    newintsize, newaddrsize);
+
+			/* Check for malformed properties */
+			if (imaplen < (newaddrsize + newintsize))
+				goto fail;
+
+			imap += newaddrsize + newintsize;
+			imaplen -= newaddrsize + newintsize;
+
+			pr_debug(" -> imaplen=%d\n", imaplen);
+		}
+		if (!match)
+			goto fail;
+
+		of_node_put(old);
+		old = of_node_get(newpar);
+		addrsize = newaddrsize;
+		intsize = newintsize;
+		intspec = imap - intsize;
+		addr = intspec - addrsize;
+
+	skiplevel:
+		/* Iterate again with new parent */
+		pr_debug(" -> new parent: %s\n", newpar ? newpar->full_name : "<>");
+		of_node_put(ipar);
+		ipar = newpar;
+		newpar = NULL;
+	}
+ fail:
+	of_node_put(ipar);
+	of_node_put(old);
+	of_node_put(newpar);
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(of_irq_map_raw);
+
+/**
+ * of_irq_map_one - Resolve an interrupt for a device
+ * @device: the device whose interrupt is to be resolved
+ * @index: index of the interrupt to resolve
+ * @out_irq: structure of_irq filled by this function
+ *
+ * This function resolves an interrupt, walking the tree, for a given
+ * device-tree node. It's the high level pendant to of_irq_map_raw().
+ */
+int of_irq_map_one(struct device_node *device, int index, struct of_irq *out_irq)
+{
+	struct device_node *p;
+	const u32 *intspec, *tmp, *addr;
+	u32 intsize, intlen;
+	int res = -EINVAL;
+
+	pr_debug("of_irq_map_one: dev=%s, index=%d\n", device->full_name, index);
+
+	/* OldWorld mac stuff is "special", handle out of line */
+	if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
+		return of_irq_map_oldworld(device, index, out_irq);
+
+	/* Get the interrupts property */
+	intspec = of_get_property(device, "interrupts", &intlen);
+	if (intspec == NULL)
+		return -EINVAL;
+	intlen /= sizeof(u32);
+
+	pr_debug(" intspec=%d intlen=%d\n", *intspec, intlen);
+
+	/* Get the reg property (if any) */
+	addr = of_get_property(device, "reg", NULL);
+
+	/* Look for the interrupt parent. */
+	p = of_irq_find_parent(device);
+	if (p == NULL)
+		return -EINVAL;
+
+	/* Get size of interrupt specifier */
+	tmp = of_get_property(p, "#interrupt-cells", NULL);
+	if (tmp == NULL)
+		goto out;
+	intsize = *tmp;
+
+	pr_debug(" intsize=%d intlen=%d\n", intsize, intlen);
+
+	/* Check index */
+	if ((index + 1) * intsize > intlen)
+		goto out;
+
+	/* Get new specifier and map it */
+	res = of_irq_map_raw(p, intspec + index * intsize, intsize,
+			     addr, out_irq);
+ out:
+	of_node_put(p);
+	return res;
+}
+EXPORT_SYMBOL_GPL(of_irq_map_one);
+
+/**
+ * of_irq_to_resource - Decode a node's IRQ and return it as a resource
+ * @dev: pointer to device tree node
+ * @index: zero-based index of the irq
+ * @r: pointer to resource structure to return result into.
+ */
+int of_irq_to_resource(struct device_node *dev, int index, struct resource *r)
+{
+	int irq = irq_of_parse_and_map(dev, index);
+
+	/* Only dereference the resource if both the
+	 * resource and the irq are valid. */
+	if (r && irq != NO_IRQ) {
+		r->start = r->end = irq;
+		r->flags = IORESOURCE_IRQ;
+	}
+
+	return irq;
+}
+EXPORT_SYMBOL_GPL(of_irq_to_resource);