arch/powerpc/sysdev/dcr.c

   1 /*
   2  * (c) Copyright 2006 Benjamin Herrenschmidt, IBM Corp.
   3  *                    <benh@kernel.crashing.org>
   4  *
   5  *   This program is free software;  you can redistribute it and/or modify
   6  *   it under the terms of the GNU General Public License as published by
   7  *   the Free Software Foundation; either version 2 of the License, or
   8  *   (at your option) any later version.
   9  *
  10  *   This program is distributed in the hope that it will be useful,
  11  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  13  *   the GNU General Public License for more details.
  14  *
  15  *   You should have received a copy of the GNU General Public License
  16  *   along with this program;  if not, write to the Free Software
  17  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  18  */
  19
  20 #undef DEBUG
  21
  22 #include <linux/kernel.h>
  23 #include <asm/prom.h>
  24 #include <asm/dcr.h>
  25
  26 unsigned int dcr_resource_start(struct device_node *np, unsigned int index)
  27 {
  28         unsigned int ds;
  29         const u32 *dr = of_get_property(np, "dcr-reg", &ds);
  30
  31         if (dr == NULL || ds & 1 || index >= (ds / 8))
  32                 return 0;
  33
  34         return dr[index * 2];
  35 }
  36
  37 unsigned int dcr_resource_len(struct device_node *np, unsigned int index)
  38 {
  39         unsigned int ds;
  40         const u32 *dr = of_get_property(np, "dcr-reg", &ds);
  41
  42         if (dr == NULL || ds & 1 || index >= (ds / 8))
  43                 return 0;
  44
  45         return dr[index * 2 + 1];
  46 }
  47
  48 #ifndef CONFIG_PPC_DCR_NATIVE
  49
  50 static struct device_node * find_dcr_parent(struct device_node * node)
  51 {
  52         struct device_node *par, *tmp;
  53         const u32 *p;
  54
  55         for (par = of_node_get(node); par;) {
  56                 if (of_get_property(par, "dcr-controller", NULL))
  57                         break;
  58                 p = of_get_property(par, "dcr-parent", NULL);
  59                 tmp = par;
  60                 if (p == NULL)
  61                         par = of_get_parent(par);
  62                 else
  63                         par = of_find_node_by_phandle(*p);
  64                 of_node_put(tmp);
  65         }
  66         return par;
  67 }
  68
  69 u64 of_translate_dcr_address(struct device_node *dev,
  70                              unsigned int dcr_n,
  71                              unsigned int *out_stride)
  72 {
  73         struct device_node *dp;
  74         const u32 *p;
  75         unsigned int stride;
  76         u64 ret;
  77
  78         dp = find_dcr_parent(dev);
  79         if (dp == NULL)
  80                 return OF_BAD_ADDR;
  81
  82         /* Stride is not properly defined yet, default to 0x10 for Axon */
  83         p = of_get_property(dp, "dcr-mmio-stride", NULL);
  84         stride = (p == NULL) ? 0x10 : *p;
  85
  86         /* XXX FIXME: Which property name is to use of the 2 following ? */
  87         p = of_get_property(dp, "dcr-mmio-range", NULL);
  88         if (p == NULL)
  89                 p = of_get_property(dp, "dcr-mmio-space", NULL);
  90         if (p == NULL)
  91                 return OF_BAD_ADDR;
  92
  93         /* Maybe could do some better range checking here */
  94         ret = of_translate_address(dp, p);
  95         if (ret != OF_BAD_ADDR)
  96                 ret += (u64)(stride) * (u64)dcr_n;
  97         if (out_stride)
  98                 *out_stride = stride;
  99         return ret;
 100 }
 101
 102 dcr_host_t dcr_map(struct device_node *dev, unsigned int dcr_n,
 103                    unsigned int dcr_c)
 104 {
 105         dcr_host_t ret = { .token = NULL, .stride = 0 };
 106         u64 addr;
 107
 108         pr_debug("dcr_map(%s, 0x%x, 0x%x)\n",
 109                  dev->full_name, dcr_n, dcr_c);
 110
 111         addr = of_translate_dcr_address(dev, dcr_n, &ret.stride);
 112         pr_debug("translates to addr: 0x%lx, stride: 0x%x\n",
 113                  addr, ret.stride);
 114         if (addr == OF_BAD_ADDR)
 115                 return ret;
 116         pr_debug("mapping 0x%x bytes\n", dcr_c * ret.stride);
 117         ret.token = ioremap(addr, dcr_c * ret.stride);
 118         if (ret.token == NULL)
 119                 return ret;
 120         pr_debug("mapped at 0x%p -> base is 0x%p\n",
 121                  ret.token, ret.token - dcr_n * ret.stride);
 122         ret.token -= dcr_n * ret.stride;
 123         return ret;
 124 }
 125
 126 void dcr_unmap(dcr_host_t host, unsigned int dcr_n, unsigned int dcr_c)
 127 {
 128         dcr_host_t h = host;
 129
 130         if (h.token == NULL)
 131                 return;
 132         h.token += dcr_n * h.stride;
 133         iounmap(h.token);
 134         h.token = NULL;
 135 }
 136
 137 #endif /* !defined(CONFIG_PPC_DCR_NATIVE) */