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  * @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;
  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         mask = DMA_BIT_MASK(ilog2(dma_addr + size - 1) + 1);
 152         dev->bus_dma_mask = mask;
 153         dev->coherent_dma_mask &= mask;
 154         *dev->dma_mask &= mask;
 155
 156         coherent = of_dma_is_coherent(np);
 157         dev_dbg(dev, "device is%sdma coherent\n",
 158                 coherent ? " " : " not ");
 159
 160         iommu = of_iommu_configure(dev, np);
 161         if (IS_ERR(iommu) && PTR_ERR(iommu) == -EPROBE_DEFER)
 162                 return -EPROBE_DEFER;
 163
 164         dev_dbg(dev, "device is%sbehind an iommu\n",
 165                 iommu ? " " : " not ");
 166
 167         arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent);
 168
 169         return 0;
 170 }
 171 EXPORT_SYMBOL_GPL(of_dma_configure);
 172
 173 /**
 174  * of_dma_deconfigure - Clean up DMA configuration
 175  * @dev:        Device for which to clean up DMA configuration
 176  *
 177  * Clean up all configuration performed by of_dma_configure_ops() and free all
 178  * resources that have been allocated.
 179  */
 180 void of_dma_deconfigure(struct device *dev)
 181 {
 182         arch_teardown_dma_ops(dev);
 183 }
 184
 185 int of_device_register(struct platform_device *pdev)
 186 {
 187         device_initialize(&pdev->dev);
 188         return of_device_add(pdev);
 189 }
 190 EXPORT_SYMBOL(of_device_register);
 191
 192 void of_device_unregister(struct platform_device *ofdev)
 193 {
 194         device_unregister(&ofdev->dev);
 195 }
 196 EXPORT_SYMBOL(of_device_unregister);
 197
 198 const void *of_device_get_match_data(const struct device *dev)
 199 {
 200         const struct of_device_id *match;
 201
 202         match = of_match_device(dev->driver->of_match_table, dev);
 203         if (!match)
 204                 return NULL;
 205
 206         return match->data;
 207 }
 208 EXPORT_SYMBOL(of_device_get_match_data);
 209
 210 static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
 211 {
 212         const char *compat;
 213         char *c;
 214         struct property *p;
 215         ssize_t csize;
 216         ssize_t tsize;
 217
 218         if ((!dev) || (!dev->of_node))
 219                 return -ENODEV;
 220
 221         /* Name & Type */
 222         csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
 223                          dev->of_node->type);
 224         tsize = csize;
 225         len -= csize;
 226         if (str)
 227                 str += csize;
 228
 229         of_property_for_each_string(dev->of_node, "compatible", p, compat) {
 230                 csize = strlen(compat) + 1;
 231                 tsize += csize;
 232                 if (csize > len)
 233                         continue;
 234
 235                 csize = snprintf(str, len, "C%s", compat);
 236                 for (c = str; c; ) {
 237                         c = strchr(c, ' ');
 238                         if (c)
 239                                 *c++ = '_';
 240                 }
 241                 len -= csize;
 242                 str += csize;
 243         }
 244
 245         return tsize;
 246 }
 247
 248 int of_device_request_module(struct device *dev)
 249 {
 250         char *str;
 251         ssize_t size;
 252         int ret;
 253
 254         size = of_device_get_modalias(dev, NULL, 0);
 255         if (size < 0)
 256                 return size;
 257
 258         str = kmalloc(size + 1, GFP_KERNEL);
 259         if (!str)
 260                 return -ENOMEM;
 261
 262         of_device_get_modalias(dev, str, size);
 263         str[size] = '\0';
 264         ret = request_module(str);
 265         kfree(str);
 266
 267         return ret;
 268 }
 269 EXPORT_SYMBOL_GPL(of_device_request_module);
 270
 271 /**
 272  * of_device_modalias - Fill buffer with newline terminated modalias string
 273  */
 274 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len)
 275 {
 276         ssize_t sl = of_device_get_modalias(dev, str, len - 2);
 277         if (sl < 0)
 278                 return sl;
 279         if (sl > len - 2)
 280                 return -ENOMEM;
 281
 282         str[sl++] = '\n';
 283         str[sl] = 0;
 284         return sl;
 285 }
 286 EXPORT_SYMBOL_GPL(of_device_modalias);
 287
 288 /**
 289  * of_device_uevent - Display OF related uevent information
 290  */
 291 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 292 {
 293         const char *compat;
 294         struct alias_prop *app;
 295         struct property *p;
 296         int seen = 0;
 297
 298         if ((!dev) || (!dev->of_node))
 299                 return;
 300
 301         add_uevent_var(env, "OF_NAME=%s", dev->of_node->name);
 302         add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node);
 303         if (dev->of_node->type && strcmp("<NULL>", dev->of_node->type) != 0)
 304                 add_uevent_var(env, "OF_TYPE=%s", dev->of_node->type);
 305
 306         /* Since the compatible field can contain pretty much anything
 307          * it's not really legal to split it out with commas. We split it
 308          * up using a number of environment variables instead. */
 309         of_property_for_each_string(dev->of_node, "compatible", p, compat) {
 310                 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
 311                 seen++;
 312         }
 313         add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
 314
 315         seen = 0;
 316         mutex_lock(&of_mutex);
 317         list_for_each_entry(app, &aliases_lookup, link) {
 318                 if (dev->of_node == app->np) {
 319                         add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
 320                                        app->alias);
 321                         seen++;
 322                 }
 323         }
 324         mutex_unlock(&of_mutex);
 325 }
 326
 327 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
 328 {
 329         int sl;
 330
 331         if ((!dev) || (!dev->of_node))
 332                 return -ENODEV;
 333
 334         /* Devicetree modalias is tricky, we add it in 2 steps */
 335         if (add_uevent_var(env, "MODALIAS="))
 336                 return -ENOMEM;
 337
 338         sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
 339                                     sizeof(env->buf) - env->buflen);
 340         if (sl >= (sizeof(env->buf) - env->buflen))
 341                 return -ENOMEM;
 342         env->buflen += sl;
 343
 344         return 0;
 345 }
 346 EXPORT_SYMBOL_GPL(of_device_uevent_modalias);