Commit ff61bacd authored by Rob Herring's avatar Rob Herring
Browse files

of/address: Add of_property_read_reg() helper 

Add a helper, of_property_read_reg(), to read "reg" entries untranslated
address and size. This function is intended mainly for cases with an
untranslatable "reg" address (i.e. not MMIO). There's also a few
translatable cases such as address cells containing a bus chip-select
number.

Link: https://lore.kernel.org/r/20230328-dt-address-helpers-v1-5-e2456c3e77ab@kernel.org


Signed-off-by: default avatarRob Herring <robh@kernel.org>
parent b50c788a

drivers/of/address.c

+23 −0
Original line number Diff line number Diff line
@@ -760,6 +760,29 @@ const __be32 *__of_get_address(struct device_node *dev, int index, int bar_no, 
}

EXPORT_SYMBOL(__of_get_address);



/**

 * of_property_read_reg - Retrieve the specified "reg" entry index without translating

 * @np: device tree node for which to retrieve "reg" from

 * @idx: "reg" entry index to read

 * @addr: return value for the untranslated address

 * @size: return value for the entry size

 *

 * Returns -EINVAL if "reg" is not found. Returns 0 on success with addr and

 * size values filled in.

 */

int of_property_read_reg(struct device_node *np, int idx, u64 *addr, u64 *size)

{

	const __be32 *prop = of_get_address(np, idx, size, NULL);



	if (!prop)

		return -EINVAL;



	*addr = of_read_number(prop, of_n_addr_cells(np));



	return 0;

}

EXPORT_SYMBOL(of_property_read_reg);



static int parser_init(struct of_pci_range_parser *parser,

			struct device_node *node, const char *name)

{

drivers/of/unittest.c

+22 −0
Original line number Diff line number Diff line
@@ -1134,6 +1134,27 @@ static void __init of_unittest_bus_3cell_ranges(void) 
	of_node_put(np);

}



static void __init of_unittest_reg(void)

{

	struct device_node *np;

	int ret;

	u64 addr, size;



	np = of_find_node_by_path("/testcase-data/address-tests/bus@80000000/device@1000");

	if (!np) {

		pr_err("missing testcase data\n");

		return;

	}



	ret = of_property_read_reg(np, 0, &addr, &size);

	unittest(!ret, "of_property_read_reg(%pOF) returned error %d\n",

		np, ret);

	unittest(addr == 0x1000, "of_property_read_reg(%pOF) untranslated address (%llx) incorrect\n",

		np, addr);



	of_node_put(np);

}



static void __init of_unittest_parse_interrupts(void)

{

	struct device_node *np;
@@ -3772,6 +3793,7 @@ static int __init of_unittest(void) 
	of_unittest_pci_dma_ranges();

	of_unittest_bus_ranges();

	of_unittest_bus_3cell_ranges();

	of_unittest_reg();

	of_unittest_match_node();

	of_unittest_platform_populate();

	of_unittest_overlay();

include/linux/of_address.h

+7 −0
Original line number Diff line number Diff line
@@ -72,6 +72,8 @@ void __iomem *of_io_request_and_map(struct device_node *device, 
extern const __be32 *__of_get_address(struct device_node *dev, int index, int bar_no,

				      u64 *size, unsigned int *flags);



int of_property_read_reg(struct device_node *np, int idx, u64 *addr, u64 *size);



extern int of_pci_range_parser_init(struct of_pci_range_parser *parser,

			struct device_node *node);

extern int of_pci_dma_range_parser_init(struct of_pci_range_parser *parser,
@@ -106,6 +108,11 @@ static inline const __be32 *__of_get_address(struct device_node *dev, int index, 
	return NULL;

}



static inline int of_property_read_reg(struct device_node *np, int idx, u64 *addr, u64 *size)

{

	return -ENOSYS;

}



static inline int of_pci_range_parser_init(struct of_pci_range_parser *parser,

			struct device_node *node)

{