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 <linux/export.h>
  24 #include <asm/prom.h>
  25 #include <asm/dcr.h>
  26
  27 #ifdef CONFIG_PPC_DCR_MMIO
  28 static struct device_node *find_dcr_parent(struct device_node *node)
  29 {
  30         struct device_node *par, *tmp;
  31         const u32 *p;
  32
  33         for (par = of_node_get(node); par;) {
  34                 if (of_get_property(par, "dcr-controller", NULL))
  35                         break;
  36                 p = of_get_property(par, "dcr-parent", NULL);
  37                 tmp = par;
  38                 if (p == NULL)
  39                         par = of_get_parent(par);
  40                 else
  41                         par = of_find_node_by_phandle(*p);
  42                 of_node_put(tmp);
  43         }
  44         return par;
  45 }
  46 #endif
  47
  48 #if defined(CONFIG_PPC_DCR_NATIVE) && defined(CONFIG_PPC_DCR_MMIO)
  49
  50 bool dcr_map_ok_generic(dcr_host_t host)
  51 {
  52         if (host.type == DCR_HOST_NATIVE)
  53                 return dcr_map_ok_native(host.host.native);
  54         else if (host.type == DCR_HOST_MMIO)
  55                 return dcr_map_ok_mmio(host.host.mmio);
  56         else
  57                 return false;
  58 }
  59 EXPORT_SYMBOL_GPL(dcr_map_ok_generic);
  60
  61 dcr_host_t dcr_map_generic(struct device_node *dev,
  62                            unsigned int dcr_n,
  63                            unsigned int dcr_c)
  64 {
  65         dcr_host_t host;
  66         struct device_node *dp;
  67         const char *prop;
  68
  69         host.type = DCR_HOST_INVALID;
  70
  71         dp = find_dcr_parent(dev);
  72         if (dp == NULL)
  73                 return host;
  74
  75         prop = of_get_property(dp, "dcr-access-method", NULL);
  76
  77         pr_debug("dcr_map_generic(dcr-access-method = %s)\n", prop);
  78
  79         if (!strcmp(prop, "native")) {
  80                 host.type = DCR_HOST_NATIVE;
  81                 host.host.native = dcr_map_native(dev, dcr_n, dcr_c);
  82         } else if (!strcmp(prop, "mmio")) {
  83                 host.type = DCR_HOST_MMIO;
  84                 host.host.mmio = dcr_map_mmio(dev, dcr_n, dcr_c);
  85         }
  86
  87         of_node_put(dp);
  88         return host;
  89 }
  90 EXPORT_SYMBOL_GPL(dcr_map_generic);
  91
  92 void dcr_unmap_generic(dcr_host_t host, unsigned int dcr_c)
  93 {
  94         if (host.type == DCR_HOST_NATIVE)
  95                 dcr_unmap_native(host.host.native, dcr_c);
  96         else if (host.type == DCR_HOST_MMIO)
  97                 dcr_unmap_mmio(host.host.mmio, dcr_c);
  98         else /* host.type == DCR_HOST_INVALID */
  99                 WARN_ON(true);
 100 }
 101 EXPORT_SYMBOL_GPL(dcr_unmap_generic);
 102
 103 u32 dcr_read_generic(dcr_host_t host, unsigned int dcr_n)
 104 {
 105         if (host.type == DCR_HOST_NATIVE)
 106                 return dcr_read_native(host.host.native, dcr_n);
 107         else if (host.type == DCR_HOST_MMIO)
 108                 return dcr_read_mmio(host.host.mmio, dcr_n);
 109         else /* host.type == DCR_HOST_INVALID */
 110                 WARN_ON(true);
 111         return 0;
 112 }
 113 EXPORT_SYMBOL_GPL(dcr_read_generic);
 114
 115 void dcr_write_generic(dcr_host_t host, unsigned int dcr_n, u32 value)
 116 {
 117         if (host.type == DCR_HOST_NATIVE)
 118                 dcr_write_native(host.host.native, dcr_n, value);
 119         else if (host.type == DCR_HOST_MMIO)
 120                 dcr_write_mmio(host.host.mmio, dcr_n, value);
 121         else /* host.type == DCR_HOST_INVALID */
 122                 WARN_ON(true);
 123 }
 124 EXPORT_SYMBOL_GPL(dcr_write_generic);
 125
 126 #endif /* defined(CONFIG_PPC_DCR_NATIVE) && defined(CONFIG_PPC_DCR_MMIO) */
 127
 128 unsigned int dcr_resource_start(const struct device_node *np,
 129                                 unsigned int index)
 130 {
 131         unsigned int ds;
 132         const u32 *dr = of_get_property(np, "dcr-reg", &ds);
 133
 134         if (dr == NULL || ds & 1 || index >= (ds / 8))
 135                 return 0;
 136
 137         return dr[index * 2];
 138 }
 139 EXPORT_SYMBOL_GPL(dcr_resource_start);
 140
 141 unsigned int dcr_resource_len(const struct device_node *np, unsigned int index)
 142 {
 143         unsigned int ds;
 144         const u32 *dr = of_get_property(np, "dcr-reg", &ds);
 145
 146         if (dr == NULL || ds & 1 || index >= (ds / 8))
 147                 return 0;
 148
 149         return dr[index * 2 + 1];
 150 }
 151 EXPORT_SYMBOL_GPL(dcr_resource_len);
 152
 153 #ifdef CONFIG_PPC_DCR_MMIO
 154
 155 static u64 of_translate_dcr_address(struct device_node *dev,
 156                                     unsigned int dcr_n,
 157                                     unsigned int *out_stride)
 158 {
 159         struct device_node *dp;
 160         const u32 *p;
 161         unsigned int stride;
 162         u64 ret = OF_BAD_ADDR;
 163
 164         dp = find_dcr_parent(dev);
 165         if (dp == NULL)
 166                 return OF_BAD_ADDR;
 167
 168         /* Stride is not properly defined yet, default to 0x10 for Axon */
 169         p = of_get_property(dp, "dcr-mmio-stride", NULL);
 170         stride = (p == NULL) ? 0x10 : *p;
 171
 172         /* XXX FIXME: Which property name is to use of the 2 following ? */
 173         p = of_get_property(dp, "dcr-mmio-range", NULL);
 174         if (p == NULL)
 175                 p = of_get_property(dp, "dcr-mmio-space", NULL);
 176         if (p == NULL)
 177                 goto done;
 178
 179         /* Maybe could do some better range checking here */
 180         ret = of_translate_address(dp, p);
 181         if (ret != OF_BAD_ADDR)
 182                 ret += (u64)(stride) * (u64)dcr_n;
 183         if (out_stride)
 184                 *out_stride = stride;
 185
 186  done:
 187         of_node_put(dp);
 188         return ret;
 189 }
 190
 191 dcr_host_mmio_t dcr_map_mmio(struct device_node *dev,
 192                              unsigned int dcr_n,
 193                              unsigned int dcr_c)
 194 {
 195         dcr_host_mmio_t ret = { .token = NULL, .stride = 0, .base = dcr_n };
 196         u64 addr;
 197
 198         pr_debug("dcr_map(%s, 0x%x, 0x%x)\n",
 199                  dev->full_name, dcr_n, dcr_c);
 200
 201         addr = of_translate_dcr_address(dev, dcr_n, &ret.stride);
 202         pr_debug("translates to addr: 0x%llx, stride: 0x%x\n",
 203                  (unsigned long long) addr, ret.stride);
 204         if (addr == OF_BAD_ADDR)
 205                 return ret;
 206         pr_debug("mapping 0x%x bytes\n", dcr_c * ret.stride);
 207         ret.token = ioremap(addr, dcr_c * ret.stride);
 208         if (ret.token == NULL)
 209                 return ret;
 210         pr_debug("mapped at 0x%p -> base is 0x%p\n",
 211                  ret.token, ret.token - dcr_n * ret.stride);
 212         ret.token -= dcr_n * ret.stride;
 213         return ret;
 214 }
 215 EXPORT_SYMBOL_GPL(dcr_map_mmio);
 216
 217 void dcr_unmap_mmio(dcr_host_mmio_t host, unsigned int dcr_c)
 218 {
 219         dcr_host_mmio_t h = host;
 220
 221         if (h.token == NULL)
 222                 return;
 223         h.token += host.base * h.stride;
 224         iounmap(h.token);
 225         h.token = NULL;
 226 }
 227 EXPORT_SYMBOL_GPL(dcr_unmap_mmio);
 228
 229 #endif /* defined(CONFIG_PPC_DCR_MMIO) */
 230
 231 #ifdef CONFIG_PPC_DCR_NATIVE
 232 DEFINE_SPINLOCK(dcr_ind_lock);
 233 EXPORT_SYMBOL_GPL(dcr_ind_lock);
 234 #endif  /* defined(CONFIG_PPC_DCR_NATIVE) */
 235