arch/powerpc/kernel/prom_parse.c

   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 }