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  * @ids: 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  *
  80  * Try to get devices's DMA configuration from DT and update it
  81  * accordingly.
  82  *
  83  * If platform code needs to use its own special DMA configuration, it
  84  * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
  85  * to fix up DMA configuration.
  86  */
  87 int of_dma_configure(struct device *dev, struct device_node *np)
  88 {
  89         u64 dma_addr, paddr, size = 0;
  90         int ret;
  91         bool coherent;
  92         unsigned long offset;
  93         const struct iommu_ops *iommu;
  94         u64 mask;
  95
  96         ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
  97         if (ret < 0) {
  98                 /*
  99                  * For legacy reasons, we have to assume some devices need
 100                  * DMA configuration regardless of whether "dma-ranges" is
 101                  * correctly specified or not.
 102                  */
 103                 if (!dev->bus->force_dma)
 104                         return ret == -ENODEV ? 0 : ret;
 105
 106                 dma_addr = offset = 0;
 107         } else {
 108                 offset = PFN_DOWN(paddr - dma_addr);
 109
 110                 /*
 111                  * Add a work around to treat the size as mask + 1 in case
 112                  * it is defined in DT as a mask.
 113                  */
 114                 if (size & 1) {
 115                         dev_warn(dev, "Invalid size 0x%llx for dma-range\n",
 116                                  size);
 117                         size = size + 1;
 118                 }
 119
 120                 if (!size) {
 121                         dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
 122                         return -EINVAL;
 123                 }
 124                 dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset);
 125         }
 126
 127         /*
 128          * Set default coherent_dma_mask to 32 bit.  Drivers are expected to
 129          * setup the correct supported mask.
 130          */
 131         if (!dev->coherent_dma_mask)
 132                 dev->coherent_dma_mask = DMA_BIT_MASK(32);
 133         /*
 134          * Set it to coherent_dma_mask by default if the architecture
 135          * code has not set it.
 136          */
 137         if (!dev->dma_mask)
 138                 dev->dma_mask = &dev->coherent_dma_mask;
 139
 140         if (!size)
 141                 size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
 142
 143         dev->dma_pfn_offset = offset;
 144
 145         /*
 146          * Limit coherent and dma mask based on size and default mask
 147          * set by the driver.
 148          */
 149         mask = DMA_BIT_MASK(ilog2(dma_addr + size - 1) + 1);
 150         dev->coherent_dma_mask &= mask;
 151         *dev->dma_mask &= mask;
 152
 153         coherent = of_dma_is_coherent(np);
 154         dev_dbg(dev, "device is%sdma coherent\n",
 155                 coherent ? " " : " not ");
 156
 157         iommu = of_iommu_configure(dev, np);
 158         if (IS_ERR(iommu) && PTR_ERR(iommu) == -EPROBE_DEFER)
 159                 return -EPROBE_DEFER;
 160
 161         dev_dbg(dev, "device is%sbehind an iommu\n",
 162                 iommu ? " " : " not ");
 163
 164         arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent);
 165
 166         return 0;
 167 }
 168 EXPORT_SYMBOL_GPL(of_dma_configure);
 169
 170 /**
 171  * of_dma_deconfigure - Clean up DMA configuration
 172  * @dev:        Device for which to clean up DMA configuration
 173  *
 174  * Clean up all configuration performed by of_dma_configure_ops() and free all
 175  * resources that have been allocated.
 176  */
 177 void of_dma_deconfigure(struct device *dev)
 178 {
 179         arch_teardown_dma_ops(dev);
 180 }
 181
 182 int of_device_register(struct platform_device *pdev)
 183 {
 184         device_initialize(&pdev->dev);
 185         return of_device_add(pdev);
 186 }
 187 EXPORT_SYMBOL(of_device_register);
 188
 189 void of_device_unregister(struct platform_device *ofdev)
 190 {
 191         device_unregister(&ofdev->dev);
 192 }
 193 EXPORT_SYMBOL(of_device_unregister);
 194
 195 const void *of_device_get_match_data(const struct device *dev)
 196 {
 197         const struct of_device_id *match;
 198
 199         match = of_match_device(dev->driver->of_match_table, dev);
 200         if (!match)
 201                 return NULL;
 202
 203         return match->data;
 204 }
 205 EXPORT_SYMBOL(of_device_get_match_data);
 206
 207 static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
 208 {
 209         const char *compat;
 210         char *c;
 211         struct property *p;
 212         ssize_t csize;
 213         ssize_t tsize;
 214
 215         if ((!dev) || (!dev->of_node))
 216                 return -ENODEV;
 217
 218         /* Name & Type */
 219         csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
 220                          dev->of_node->type);
 221         tsize = csize;
 222         len -= csize;
 223         if (str)
 224                 str += csize;
 225
 226         of_property_for_each_string(dev->of_node, "compatible", p, compat) {
 227                 csize = strlen(compat) + 1;
 228                 tsize += csize;
 229                 if (csize > len)
 230                         continue;
 231
 232                 csize = snprintf(str, len, "C%s", compat);
 233                 for (c = str; c; ) {
 234                         c = strchr(c, ' ');
 235                         if (c)
 236                                 *c++ = '_';
 237                 }
 238                 len -= csize;
 239                 str += csize;
 240         }
 241
 242         return tsize;
 243 }
 244
 245 int of_device_request_module(struct device *dev)
 246 {
 247         char *str;
 248         ssize_t size;
 249         int ret;
 250
 251         size = of_device_get_modalias(dev, NULL, 0);
 252         if (size < 0)
 253                 return size;
 254
 255         str = kmalloc(size + 1, GFP_KERNEL);
 256         if (!str)
 257                 return -ENOMEM;
 258
 259         of_device_get_modalias(dev, str, size);
 260         str[size] = '\0';
 261         ret = request_module(str);
 262         kfree(str);
 263
 264         return ret;
 265 }
 266 EXPORT_SYMBOL_GPL(of_device_request_module);
 267
 268 /**
 269  * of_device_modalias - Fill buffer with newline terminated modalias string
 270  */
 271 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len)
 272 {
 273         ssize_t sl = of_device_get_modalias(dev, str, len - 2);
 274         if (sl < 0)
 275                 return sl;
 276         if (sl > len - 2)
 277                 return -ENOMEM;
 278
 279         str[sl++] = '\n';
 280         str[sl] = 0;
 281         return sl;
 282 }
 283 EXPORT_SYMBOL_GPL(of_device_modalias);
 284
 285 /**
 286  * of_device_uevent - Display OF related uevent information
 287  */
 288 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 289 {
 290         const char *compat;
 291         struct alias_prop *app;
 292         struct property *p;
 293         int seen = 0;
 294
 295         if ((!dev) || (!dev->of_node))
 296                 return;
 297
 298         add_uevent_var(env, "OF_NAME=%s", dev->of_node->name);
 299         add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node);
 300         if (dev->of_node->type && strcmp("<NULL>", dev->of_node->type) != 0)
 301                 add_uevent_var(env, "OF_TYPE=%s", dev->of_node->type);
 302
 303         /* Since the compatible field can contain pretty much anything
 304          * it's not really legal to split it out with commas. We split it
 305          * up using a number of environment variables instead. */
 306         of_property_for_each_string(dev->of_node, "compatible", p, compat) {
 307                 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
 308                 seen++;
 309         }
 310         add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
 311
 312         seen = 0;
 313         mutex_lock(&of_mutex);
 314         list_for_each_entry(app, &aliases_lookup, link) {
 315                 if (dev->of_node == app->np) {
 316                         add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
 317                                        app->alias);
 318                         seen++;
 319                 }
 320         }
 321         mutex_unlock(&of_mutex);
 322 }
 323
 324 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 325 {
 326         int sl;
 327
 328         if ((!dev) || (!dev->of_node))
 329                 return -ENODEV;
 330
 331         /* Devicetree modalias is tricky, we add it in 2 steps */
 332         if (add_uevent_var(env, "MODALIAS="))
 333                 return -ENOMEM;
 334
 335         sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
 336                                     sizeof(env->buf) - env->buflen);
 337         if (sl >= (sizeof(env->buf) - env->buflen))
 338                 return -ENOMEM;
 339         env->buflen += sl;
 340
 341         return 0;
 342 }
 343 EXPORT_SYMBOL_GPL(of_device_uevent_modalias);