xref: /openbmc/linux/arch/powerpc/kernel/prom_parse.c (revision 842ed298)
1 // SPDX-License-Identifier: GPL-2.0
2 #undef DEBUG
3 
4 #include <linux/kernel.h>
5 #include <linux/string.h>
6 #include <linux/ioport.h>
7 #include <linux/etherdevice.h>
8 #include <linux/of_address.h>
9 #include <asm/prom.h>
10 
11 void of_parse_dma_window(struct device_node *dn, const __be32 *dma_window,
12 			 unsigned long *busno, unsigned long *phys,
13 			 unsigned long *size)
14 {
15 	u32 cells;
16 	const __be32 *prop;
17 
18 	/* busno is always one cell */
19 	*busno = of_read_number(dma_window, 1);
20 	dma_window++;
21 
22 	prop = of_get_property(dn, "ibm,#dma-address-cells", NULL);
23 	if (!prop)
24 		prop = of_get_property(dn, "#address-cells", NULL);
25 
26 	cells = prop ? of_read_number(prop, 1) : of_n_addr_cells(dn);
27 	*phys = of_read_number(dma_window, cells);
28 
29 	dma_window += cells;
30 
31 	prop = of_get_property(dn, "ibm,#dma-size-cells", NULL);
32 	cells = prop ? of_read_number(prop, 1) : of_n_size_cells(dn);
33 	*size = of_read_number(dma_window, cells);
34 }
35