drivers/of/device.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/string.h>
   3 #include <linux/kernel.h>
   4 #include <linux/of.h>
   5 #include <linux/of_device.h>
   6 #include <linux/of_address.h>
   7 #include <linux/of_iommu.h>
   8 #include <linux/dma-mapping.h>
   9 #include <linux/init.h>
  10 #include <linux/module.h>
  11 #include <linux/mod_devicetable.h>
  12 #include <linux/slab.h>
  13 #include <linux/platform_device.h>
  14
  15 #include <asm/errno.h>
  16 #include "of_private.h"
  17
  18 /**
  19  * of_match_device - Tell if a struct device matches an of_device_id list
  20  * @matches: array of of device match structures to search in
  21  * @dev: the of device structure to match against
  22  *
  23  * Used by a driver to check whether an platform_device present in the
  24  * system is in its list of supported devices.
  25  */
  26 const struct of_device_id *of_match_device(const struct of_device_id *matches,
  27                                            const struct device *dev)
  28 {
  29         if ((!matches) || (!dev->of_node))
  30                 return NULL;
  31         return of_match_node(matches, dev->of_node);
  32 }
  33 EXPORT_SYMBOL(of_match_device);
  34
  35 struct platform_device *of_dev_get(struct platform_device *dev)
  36 {
  37         struct device *tmp;
  38
  39         if (!dev)
  40                 return NULL;
  41         tmp = get_device(&dev->dev);
  42         if (tmp)
  43                 return to_platform_device(tmp);
  44         else
  45                 return NULL;
  46 }
  47 EXPORT_SYMBOL(of_dev_get);
  48
  49 void of_dev_put(struct platform_device *dev)
  50 {
  51         if (dev)
  52                 put_device(&dev->dev);
  53 }
  54 EXPORT_SYMBOL(of_dev_put);
  55
  56 int of_device_add(struct platform_device *ofdev)
  57 {
  58         BUG_ON(ofdev->dev.of_node == NULL);
  59
  60         /* name and id have to be set so that the platform bus doesn't get
  61          * confused on matching */
  62         ofdev->name = dev_name(&ofdev->dev);
  63         ofdev->id = PLATFORM_DEVID_NONE;
  64
  65         /*
  66          * If this device has not binding numa node in devicetree, that is
  67          * of_node_to_nid returns NUMA_NO_NODE. device_add will assume that this
  68          * device is on the same node as the parent.
  69          */
  70         set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
  71
  72         return device_add(&ofdev->dev);
  73 }
  74
  75 /**
  76  * of_dma_configure - Setup DMA configuration
  77  * @dev:        Device to apply DMA configuration
  78  * @np:         Pointer to OF node having DMA configuration
  79  * @force_dma:  Whether device is to be set up by of_dma_configure() even if
  80  *              DMA capability is not explicitly described by firmware.
  81  *
  82  * Try to get devices's DMA configuration from DT and update it
  83  * accordingly.
  84  *
  85  * If platform code needs to use its own special DMA configuration, it
  86  * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
  87  * to fix up DMA configuration.
  88  */
  89 int of_dma_configure(struct device *dev, struct device_node *np, bool force_dma)
  90 {
  91         u64 dma_addr, paddr, size = 0;
  92         int ret;
  93         bool coherent;
  94         unsigned long offset;
  95         const struct iommu_ops *iommu;
  96         u64 mask, end;
  97
  98         ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
  99         if (ret < 0) {
 100                 /*
 101                  * For legacy reasons, we have to assume some devices need
 102                  * DMA configuration regardless of whether "dma-ranges" is
 103                  * correctly specified or not.
 104                  */
 105                 if (!force_dma)
 106                         return ret == -ENODEV ? 0 : ret;
 107
 108                 dma_addr = offset = 0;
 109         } else {
 110                 offset = PFN_DOWN(paddr - dma_addr);
 111
 112                 /*
 113                  * Add a work around to treat the size as mask + 1 in case
 114                  * it is defined in DT as a mask.
 115                  */
 116                 if (size & 1) {
 117                         dev_warn(dev, "Invalid size 0x%llx for dma-range\n",
 118                                  size);
 119                         size = size + 1;
 120                 }
 121
 122                 if (!size) {
 123                         dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
 124                         return -EINVAL;
 125                 }
 126                 dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset);
 127         }
 128
 129         /*
 130          * If @dev is expected to be DMA-capable then the bus code that created
 131          * it should have initialised its dma_mask pointer by this point. For
 132          * now, we'll continue the legacy behaviour of coercing it to the
 133          * coherent mask if not, but we'll no longer do so quietly.
 134          */
 135         if (!dev->dma_mask) {
 136                 dev_warn(dev, "DMA mask not set\n");
 137                 dev->dma_mask = &dev->coherent_dma_mask;
 138         }
 139
 140         if (!size && dev->coherent_dma_mask)
 141                 size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
 142         else if (!size)
 143                 size = 1ULL << 32;
 144
 145         dev->dma_pfn_offset = offset;
 146
 147         /*
 148          * Limit coherent and dma mask based on size and default mask
 149          * set by the driver.
 150          */
 151         end = dma_addr + size - 1;
 152         mask = DMA_BIT_MASK(ilog2(end) + 1);
 153         dev->coherent_dma_mask &= mask;
 154         *dev->dma_mask &= mask;
 155         /* ...but only set bus limit if we found valid dma-ranges earlier */
 156         if (!ret)
 157                 dev->bus_dma_limit = end;
 158
 159         coherent = of_dma_is_coherent(np);
 160         dev_dbg(dev, "device is%sdma coherent\n",
 161                 coherent ? " " : " not ");
 162
 163         iommu = of_iommu_configure(dev, np);
 164         if (PTR_ERR(iommu) == -EPROBE_DEFER)
 165                 return -EPROBE_DEFER;
 166
 167         dev_dbg(dev, "device is%sbehind an iommu\n",
 168                 iommu ? " " : " not ");
 169
 170         arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent);
 171
 172         return 0;
 173 }
 174 EXPORT_SYMBOL_GPL(of_dma_configure);
 175
 176 int of_device_register(struct platform_device *pdev)
 177 {
 178         device_initialize(&pdev->dev);
 179         return of_device_add(pdev);
 180 }
 181 EXPORT_SYMBOL(of_device_register);
 182
 183 void of_device_unregister(struct platform_device *ofdev)
 184 {
 185         device_unregister(&ofdev->dev);
 186 }
 187 EXPORT_SYMBOL(of_device_unregister);
 188
 189 const void *of_device_get_match_data(const struct device *dev)
 190 {
 191         const struct of_device_id *match;
 192
 193         match = of_match_device(dev->driver->of_match_table, dev);
 194         if (!match)
 195                 return NULL;
 196
 197         return match->data;
 198 }
 199 EXPORT_SYMBOL(of_device_get_match_data);
 200
 201 static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
 202 {
 203         const char *compat;
 204         char *c;
 205         struct property *p;
 206         ssize_t csize;
 207         ssize_t tsize;
 208
 209         if ((!dev) || (!dev->of_node))
 210                 return -ENODEV;
 211
 212         /* Name & Type */
 213         /* %p eats all alphanum characters, so %c must be used here */
 214         csize = snprintf(str, len, "of:N%pOFn%c%s", dev->of_node, 'T',
 215                          of_node_get_device_type(dev->of_node));
 216         tsize = csize;
 217         len -= csize;
 218         if (str)
 219                 str += csize;
 220
 221         of_property_for_each_string(dev->of_node, "compatible", p, compat) {
 222                 csize = strlen(compat) + 1;
 223                 tsize += csize;
 224                 if (csize > len)
 225                         continue;
 226
 227                 csize = snprintf(str, len, "C%s", compat);
 228                 for (c = str; c; ) {
 229                         c = strchr(c, ' ');
 230                         if (c)
 231                                 *c++ = '_';
 232                 }
 233                 len -= csize;
 234                 str += csize;
 235         }
 236
 237         return tsize;
 238 }
 239
 240 int of_device_request_module(struct device *dev)
 241 {
 242         char *str;
 243         ssize_t size;
 244         int ret;
 245
 246         size = of_device_get_modalias(dev, NULL, 0);
 247         if (size < 0)
 248                 return size;
 249
 250         str = kmalloc(size + 1, GFP_KERNEL);
 251         if (!str)
 252                 return -ENOMEM;
 253
 254         of_device_get_modalias(dev, str, size);
 255         str[size] = '\0';
 256         ret = request_module(str);
 257         kfree(str);
 258
 259         return ret;
 260 }
 261 EXPORT_SYMBOL_GPL(of_device_request_module);
 262
 263 /**
 264  * of_device_modalias - Fill buffer with newline terminated modalias string
 265  */
 266 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len)
 267 {
 268         ssize_t sl = of_device_get_modalias(dev, str, len - 2);
 269         if (sl < 0)
 270                 return sl;
 271         if (sl > len - 2)
 272                 return -ENOMEM;
 273
 274         str[sl++] = '\n';
 275         str[sl] = 0;
 276         return sl;
 277 }
 278 EXPORT_SYMBOL_GPL(of_device_modalias);
 279
 280 /**
 281  * of_device_uevent - Display OF related uevent information
 282  */
 283 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 284 {
 285         const char *compat, *type;
 286         struct alias_prop *app;
 287         struct property *p;
 288         int seen = 0;
 289
 290         if ((!dev) || (!dev->of_node))
 291                 return;
 292
 293         add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node);
 294         add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node);
 295         type = of_node_get_device_type(dev->of_node);
 296         if (type)
 297                 add_uevent_var(env, "OF_TYPE=%s", type);
 298
 299         /* Since the compatible field can contain pretty much anything
 300          * it's not really legal to split it out with commas. We split it
 301          * up using a number of environment variables instead. */
 302         of_property_for_each_string(dev->of_node, "compatible", p, compat) {
 303                 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
 304                 seen++;
 305         }
 306         add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
 307
 308         seen = 0;
 309         mutex_lock(&of_mutex);
 310         list_for_each_entry(app, &aliases_lookup, link) {
 311                 if (dev->of_node == app->np) {
 312                         add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
 313                                        app->alias);
 314                         seen++;
 315                 }
 316         }
 317         mutex_unlock(&of_mutex);
 318 }
 319
 320 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 321 {
 322         int sl;
 323
 324         if ((!dev) || (!dev->of_node))
 325                 return -ENODEV;
 326
 327         /* Devicetree modalias is tricky, we add it in 2 steps */
 328         if (add_uevent_var(env, "MODALIAS="))
 329                 return -ENOMEM;
 330
 331         sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
 332                                     sizeof(env->buf) - env->buflen);
 333         if (sl >= (sizeof(env->buf) - env->buflen))
 334                 return -ENOMEM;
 335         env->buflen += sl;
 336
 337         return 0;
 338 }
 339 EXPORT_SYMBOL_GPL(of_device_uevent_modalias);