Commit 49d2cda7 authored by Herve Codina (Schneider Electric)'s avatar Herve Codina (Schneider Electric) Committed by Geert Uytterhoeven
Browse files

of/irq: Introduce for_each_of_imap_item 



for_each_of_imap_item is an iterator designed to help a driver to parse
an interrupt-map property.

Indeed some drivers need to know details about the interrupt mapping
described in the device-tree in order to set internal registers
accordingly.

Signed-off-by: default avatarHerve Codina (Schneider Electric) <herve.codina@bootlin.com>
Tested-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: default avatarRob Herring (Arm) <robh@kernel.org>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Link: https://patch.msgid.link/20260114093938.1089936-2-herve.codina@bootlin.com


Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
parent 1bea7e94

drivers/of/irq.c

+70 −0
Original line number Diff line number Diff line
@@ -157,6 +157,76 @@ const __be32 *of_irq_parse_imap_parent(const __be32 *imap, int len, struct of_ph 
	return imap;

}



int of_imap_parser_init(struct of_imap_parser *parser, struct device_node *node,

			struct of_imap_item *item)

{

	int imaplen;

	u32 tmp;

	int ret;



	/*

	 * parent_offset is the offset where the parent part is starting.

	 * In other words, the offset where the parent interrupt controller

	 * phandle is present.

	 *

	 * Compute this offset (child #interrupt-cells + child #address-cells)

	 */

	parser->parent_offset = of_bus_n_addr_cells(node);



	ret = of_property_read_u32(node, "#interrupt-cells", &tmp);

	if (ret)

		return ret;



	parser->parent_offset += tmp;



	if (WARN(parser->parent_offset > ARRAY_SIZE(item->child_imap),

		 "child part size = %u, cannot fit in array of %zu items",

		 parser->parent_offset, ARRAY_SIZE(item->child_imap)))

		return -EINVAL;



	parser->imap = of_get_property(node, "interrupt-map", &imaplen);

	if (!parser->imap)

		return -ENOENT;



	imaplen /= sizeof(*parser->imap);

	parser->imap_end = parser->imap + imaplen;



	memset(item, 0, sizeof(*item));

	item->child_imap_count = parser->parent_offset;



	return 0;

}

EXPORT_SYMBOL_GPL(of_imap_parser_init);



struct of_imap_item *of_imap_parser_one(struct of_imap_parser *parser,

					struct of_imap_item *item)

{

	const __be32 *imap_parent, *imap_next;

	int i;



	/* Release previously get parent node */

	of_node_put(item->parent_args.np);



	if (parser->imap + parser->parent_offset + 1 >= parser->imap_end)

		return NULL;



	imap_parent = parser->imap + parser->parent_offset;



	imap_next = of_irq_parse_imap_parent(imap_parent,

					     parser->imap_end - imap_parent,

					     &item->parent_args);

	if (!imap_next)

		return NULL;



	for (i = 0; i < parser->parent_offset; i++)

		item->child_imap[i] = be32_to_cpu(*(parser->imap + i));



	parser->imap = imap_next;



	return item;

}

EXPORT_SYMBOL_GPL(of_imap_parser_one);



/**

 * of_irq_parse_raw - Low level interrupt tree parsing

 * @addr:	address specifier (start of "reg" property of the device) in be32 format

include/linux/of_irq.h

+40 −1
Original line number Diff line number Diff line
@@ -11,6 +11,30 @@ 


typedef int (*of_irq_init_cb_t)(struct device_node *, struct device_node *);



struct of_imap_parser {

	struct device_node *node;

	const __be32 *imap;

	const __be32 *imap_end;

	u32 parent_offset;

};



struct of_imap_item {

	struct of_phandle_args parent_args;

	u32 child_imap_count;

	u32 child_imap[16]; /* Arbitrary size.

			     * Should be #address-cells + #interrupt-cells but

			     * avoid using allocation and so, expect that 16

			     * should be enough

			     */

};



/*

 * If the iterator is exited prematurely (break, goto, return) of_node_put() has

 * to be called on item.parent_args.np

 */

#define for_each_of_imap_item(parser, item) \

	for (; of_imap_parser_one(parser, item);)



/*

 * Workarounds only applied to 32bit powermac machines

 */
@@ -49,6 +73,11 @@ extern int of_irq_get_byname(struct device_node *dev, const char *name); 
extern int of_irq_to_resource_table(struct device_node *dev,

		struct resource *res, int nr_irqs);

extern struct device_node *of_irq_find_parent(struct device_node *child);

extern int of_imap_parser_init(struct of_imap_parser *parser,

			       struct device_node *node,

			       struct of_imap_item *item);

extern struct of_imap_item *of_imap_parser_one(struct of_imap_parser *parser,

					       struct of_imap_item *item);

extern struct irq_domain *of_msi_get_domain(struct device *dev,

					    const struct device_node *np,

					    enum irq_domain_bus_token token);
@@ -92,7 +121,17 @@ static inline void *of_irq_find_parent(struct device_node *child) 
{

	return NULL;

}



static inline int of_imap_parser_init(struct of_imap_parser *parser,

				      struct device_node *node,

				      struct of_imap_item *item)

{

	return -ENOSYS;

}

static inline struct of_imap_item *of_imap_parser_one(struct of_imap_parser *parser,

						      struct of_imap_item *item)

{

	return NULL;

}

static inline struct irq_domain *of_msi_get_domain(struct device *dev,

						   struct device_node *np,

						   enum irq_domain_bus_token token)