powerpc/kernel/prom_parse.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 #undef DEBUG
0003
0004 #include <linux/kernel.h>
0005 #include <linux/string.h>
0006 #include <linux/ioport.h>
0007 #include <linux/etherdevice.h>
0008 #include <linux/of_address.h>
0009 #include <asm/prom.h>
0010
0011 void of_parse_dma_window(struct device_node *dn, const __be32 *dma_window,
0012              unsigned long *busno, unsigned long *phys,
0013              unsigned long *size)
0014 {
0015     u32 cells;
0016     const __be32 *prop;
0017
0018     /* busno is always one cell */
0019     *busno = of_read_number(dma_window, 1);
0020     dma_window++;
0021
0022     prop = of_get_property(dn, "ibm,#dma-address-cells", NULL);
0023     if (!prop)
0024         prop = of_get_property(dn, "#address-cells", NULL);
0025
0026     cells = prop ? of_read_number(prop, 1) : of_n_addr_cells(dn);
0027     *phys = of_read_number(dma_window, cells);
0028
0029     dma_window += cells;
0030
0031     prop = of_get_property(dn, "ibm,#dma-size-cells", NULL);
0032     cells = prop ? of_read_number(prop, 1) : of_n_size_cells(dn);
0033     *size = of_read_number(dma_window, cells);
0034 }