LXR linux/arch/powerpc/sysdev/dcr.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * (c) Copyright 2006 Benjamin Herrenschmidt, IBM Corp.
   4 *                    <benh@kernel.crashing.org>
   5 */
   6
   7#undef DEBUG
   8
   9#include <linux/kernel.h>
  10#include <linux/export.h>
  11#include <asm/prom.h>
  12#include <asm/dcr.h>
  13
  14#ifdef CONFIG_PPC_DCR_MMIO
  15static struct device_node *find_dcr_parent(struct device_node *node)
  16{
  17        struct device_node *par, *tmp;
  18        const u32 *p;
  19
  20        for (par = of_node_get(node); par;) {
  21                if (of_get_property(par, "dcr-controller", NULL))
  22                        break;
  23                p = of_get_property(par, "dcr-parent", NULL);
  24                tmp = par;
  25                if (p == NULL)
  26                        par = of_get_parent(par);
  27                else
  28                        par = of_find_node_by_phandle(*p);
  29                of_node_put(tmp);
  30        }
  31        return par;
  32}
  33#endif
  34
  35#if defined(CONFIG_PPC_DCR_NATIVE) && defined(CONFIG_PPC_DCR_MMIO)
  36
  37bool dcr_map_ok_generic(dcr_host_t host)
  38{
  39        if (host.type == DCR_HOST_NATIVE)
  40                return dcr_map_ok_native(host.host.native);
  41        else if (host.type == DCR_HOST_MMIO)
  42                return dcr_map_ok_mmio(host.host.mmio);
  43        else
  44                return false;
  45}
  46EXPORT_SYMBOL_GPL(dcr_map_ok_generic);
  47
  48dcr_host_t dcr_map_generic(struct device_node *dev,
  49                           unsigned int dcr_n,
  50                           unsigned int dcr_c)
  51{
  52        dcr_host_t host;
  53        struct device_node *dp;
  54        const char *prop;
  55
  56        host.type = DCR_HOST_INVALID;
  57
  58        dp = find_dcr_parent(dev);
  59        if (dp == NULL)
  60                return host;
  61
  62        prop = of_get_property(dp, "dcr-access-method", NULL);
  63
  64        pr_debug("dcr_map_generic(dcr-access-method = %s)\n", prop);
  65
  66        if (!strcmp(prop, "native")) {
  67                host.type = DCR_HOST_NATIVE;
  68                host.host.native = dcr_map_native(dev, dcr_n, dcr_c);
  69        } else if (!strcmp(prop, "mmio")) {
  70                host.type = DCR_HOST_MMIO;
  71                host.host.mmio = dcr_map_mmio(dev, dcr_n, dcr_c);
  72        }
  73
  74        of_node_put(dp);
  75        return host;
  76}
  77EXPORT_SYMBOL_GPL(dcr_map_generic);
  78
  79void dcr_unmap_generic(dcr_host_t host, unsigned int dcr_c)
  80{
  81        if (host.type == DCR_HOST_NATIVE)
  82                dcr_unmap_native(host.host.native, dcr_c);
  83        else if (host.type == DCR_HOST_MMIO)
  84                dcr_unmap_mmio(host.host.mmio, dcr_c);
  85        else /* host.type == DCR_HOST_INVALID */
  86                WARN_ON(true);
  87}
  88EXPORT_SYMBOL_GPL(dcr_unmap_generic);
  89
  90u32 dcr_read_generic(dcr_host_t host, unsigned int dcr_n)
  91{
  92        if (host.type == DCR_HOST_NATIVE)
  93                return dcr_read_native(host.host.native, dcr_n);
  94        else if (host.type == DCR_HOST_MMIO)
  95                return dcr_read_mmio(host.host.mmio, dcr_n);
  96        else /* host.type == DCR_HOST_INVALID */
  97                WARN_ON(true);
  98        return 0;
  99}
 100EXPORT_SYMBOL_GPL(dcr_read_generic);
 101
 102void dcr_write_generic(dcr_host_t host, unsigned int dcr_n, u32 value)
 103{
 104        if (host.type == DCR_HOST_NATIVE)
 105                dcr_write_native(host.host.native, dcr_n, value);
 106        else if (host.type == DCR_HOST_MMIO)
 107                dcr_write_mmio(host.host.mmio, dcr_n, value);
 108        else /* host.type == DCR_HOST_INVALID */
 109                WARN_ON(true);
 110}
 111EXPORT_SYMBOL_GPL(dcr_write_generic);
 112
 113#endif /* defined(CONFIG_PPC_DCR_NATIVE) && defined(CONFIG_PPC_DCR_MMIO) */
 114
 115unsigned int dcr_resource_start(const struct device_node *np,
 116                                unsigned int index)
 117{
 118        unsigned int ds;
 119        const u32 *dr = of_get_property(np, "dcr-reg", &ds);
 120
 121        if (dr == NULL || ds & 1 || index >= (ds / 8))
 122                return 0;
 123
 124        return dr[index * 2];
 125}
 126EXPORT_SYMBOL_GPL(dcr_resource_start);
 127
 128unsigned int dcr_resource_len(const struct device_node *np, unsigned int index)
 129{
 130        unsigned int ds;
 131        const u32 *dr = of_get_property(np, "dcr-reg", &ds);
 132
 133        if (dr == NULL || ds & 1 || index >= (ds / 8))
 134                return 0;
 135
 136        return dr[index * 2 + 1];
 137}
 138EXPORT_SYMBOL_GPL(dcr_resource_len);
 139
 140#ifdef CONFIG_PPC_DCR_MMIO
 141
 142static u64 of_translate_dcr_address(struct device_node *dev,
 143                                    unsigned int dcr_n,
 144                                    unsigned int *out_stride)
 145{
 146        struct device_node *dp;
 147        const u32 *p;
 148        unsigned int stride;
 149        u64 ret = OF_BAD_ADDR;
 150
 151        dp = find_dcr_parent(dev);
 152        if (dp == NULL)
 153                return OF_BAD_ADDR;
 154
 155        /* Stride is not properly defined yet, default to 0x10 for Axon */
 156        p = of_get_property(dp, "dcr-mmio-stride", NULL);
 157        stride = (p == NULL) ? 0x10 : *p;
 158
 159        /* XXX FIXME: Which property name is to use of the 2 following ? */
 160        p = of_get_property(dp, "dcr-mmio-range", NULL);
 161        if (p == NULL)
 162                p = of_get_property(dp, "dcr-mmio-space", NULL);
 163        if (p == NULL)
 164                goto done;
 165
 166        /* Maybe could do some better range checking here */
 167        ret = of_translate_address(dp, p);
 168        if (ret != OF_BAD_ADDR)
 169                ret += (u64)(stride) * (u64)dcr_n;
 170        if (out_stride)
 171                *out_stride = stride;
 172
 173 done:
 174        of_node_put(dp);
 175        return ret;
 176}
 177
 178dcr_host_mmio_t dcr_map_mmio(struct device_node *dev,
 179                             unsigned int dcr_n,
 180                             unsigned int dcr_c)
 181{
 182        dcr_host_mmio_t ret = { .token = NULL, .stride = 0, .base = dcr_n };
 183        u64 addr;
 184
 185        pr_debug("dcr_map(%pOF, 0x%x, 0x%x)\n",
 186                 dev, dcr_n, dcr_c);
 187
 188        addr = of_translate_dcr_address(dev, dcr_n, &ret.stride);
 189        pr_debug("translates to addr: 0x%llx, stride: 0x%x\n",
 190                 (unsigned long long) addr, ret.stride);
 191        if (addr == OF_BAD_ADDR)
 192                return ret;
 193        pr_debug("mapping 0x%x bytes\n", dcr_c * ret.stride);
 194        ret.token = ioremap(addr, dcr_c * ret.stride);
 195        if (ret.token == NULL)
 196                return ret;
 197        pr_debug("mapped at 0x%p -> base is 0x%p\n",
 198                 ret.token, ret.token - dcr_n * ret.stride);
 199        ret.token -= dcr_n * ret.stride;
 200        return ret;
 201}
 202EXPORT_SYMBOL_GPL(dcr_map_mmio);
 203
 204void dcr_unmap_mmio(dcr_host_mmio_t host, unsigned int dcr_c)
 205{
 206        dcr_host_mmio_t h = host;
 207
 208        if (h.token == NULL)
 209                return;
 210        h.token += host.base * h.stride;
 211        iounmap(h.token);
 212        h.token = NULL;
 213}
 214EXPORT_SYMBOL_GPL(dcr_unmap_mmio);
 215
 216#endif /* defined(CONFIG_PPC_DCR_MMIO) */
 217
 218#ifdef CONFIG_PPC_DCR_NATIVE
 219DEFINE_SPINLOCK(dcr_ind_lock);
 220EXPORT_SYMBOL_GPL(dcr_ind_lock);
 221#endif  /* defined(CONFIG_PPC_DCR_NATIVE) */
 222
 223