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 EXPORT_SYMBOL_GPL(dcr_resource_start);
  37
  38 unsigned int dcr_resource_len(struct device_node *np, unsigned int index)
  39 {
  40         unsigned int ds;
  41         const u32 *dr = of_get_property(np, "dcr-reg", &ds);
  42
  43         if (dr == NULL || ds & 1 || index >= (ds / 8))
  44                 return 0;
  45
  46         return dr[index * 2 + 1];
  47 }
  48 EXPORT_SYMBOL_GPL(dcr_resource_len);
  49
  50 #ifndef CONFIG_PPC_DCR_NATIVE
  51
  52 static struct device_node * find_dcr_parent(struct device_node * node)
  53 {
  54         struct device_node *par, *tmp;
  55         const u32 *p;
  56
  57         for (par = of_node_get(node); par;) {
  58                 if (of_get_property(par, "dcr-controller", NULL))
  59                         break;
  60                 p = of_get_property(par, "dcr-parent", NULL);
  61                 tmp = par;
  62                 if (p == NULL)
  63                         par = of_get_parent(par);
  64                 else
  65                         par = of_find_node_by_phandle(*p);
  66                 of_node_put(tmp);
  67         }
  68         return par;
  69 }
  70
  71 u64 of_translate_dcr_address(struct device_node *dev,
  72                              unsigned int dcr_n,
  73                              unsigned int *out_stride)
  74 {
  75         struct device_node *dp;
  76         const u32 *p;
  77         unsigned int stride;
  78         u64 ret;
  79
  80         dp = find_dcr_parent(dev);
  81         if (dp == NULL)
  82                 return OF_BAD_ADDR;
  83
  84         /* Stride is not properly defined yet, default to 0x10 for Axon */
  85         p = of_get_property(dp, "dcr-mmio-stride", NULL);
  86         stride = (p == NULL) ? 0x10 : *p;
  87
  88         /* XXX FIXME: Which property name is to use of the 2 following ? */
  89         p = of_get_property(dp, "dcr-mmio-range", NULL);
  90         if (p == NULL)
  91                 p = of_get_property(dp, "dcr-mmio-space", NULL);
  92         if (p == NULL)
  93                 return OF_BAD_ADDR;
  94
  95         /* Maybe could do some better range checking here */
  96         ret = of_translate_address(dp, p);
  97         if (ret != OF_BAD_ADDR)
  98                 ret += (u64)(stride) * (u64)dcr_n;
  99         if (out_stride)
 100                 *out_stride = stride;
 101         return ret;
 102 }
 103
 104 dcr_host_t dcr_map(struct device_node *dev, unsigned int dcr_n,
 105                    unsigned int dcr_c)
 106 {
 107         dcr_host_t ret = { .token = NULL, .stride = 0, .base = dcr_n };
 108         u64 addr;
 109
 110         pr_debug("dcr_map(%s, 0x%x, 0x%x)\n",
 111                  dev->full_name, dcr_n, dcr_c);
 112
 113         addr = of_translate_dcr_address(dev, dcr_n, &ret.stride);
 114         pr_debug("translates to addr: 0x%lx, stride: 0x%x\n",
 115                  addr, ret.stride);
 116         if (addr == OF_BAD_ADDR)
 117                 return ret;
 118         pr_debug("mapping 0x%x bytes\n", dcr_c * ret.stride);
 119         ret.token = ioremap(addr, dcr_c * ret.stride);
 120         if (ret.token == NULL)
 121                 return ret;
 122         pr_debug("mapped at 0x%p -> base is 0x%p\n",
 123                  ret.token, ret.token - dcr_n * ret.stride);
 124         ret.token -= dcr_n * ret.stride;
 125         return ret;
 126 }
 127 EXPORT_SYMBOL_GPL(dcr_map);
 128
 129 void dcr_unmap(dcr_host_t host, unsigned int dcr_c)
 130 {
 131         dcr_host_t h = host;
 132
 133         if (h.token == NULL)
 134                 return;
 135         h.token += host.base * h.stride;
 136         iounmap(h.token);
 137         h.token = NULL;
 138 }
 139 EXPORT_SYMBOL_GPL(dcr_unmap);
 140
 141 #endif /* !defined(CONFIG_PPC_DCR_NATIVE) */