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-direct.h> /* for bus_dma_region */ 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 * @id: Optional const pointer value input id 82 * 83 * Try to get devices's DMA configuration from DT and update it 84 * accordingly. 85 * 86 * If platform code needs to use its own special DMA configuration, it 87 * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events 88 * to fix up DMA configuration. 89 */ 90 int of_dma_configure_id(struct device *dev, struct device_node *np, 91 bool force_dma, const u32 *id) 92 { 93 const struct iommu_ops *iommu; 94 const struct bus_dma_region *map = NULL; 95 dma_addr_t dma_start = 0; 96 u64 mask, end, size = 0; 97 bool coherent; 98 int ret; 99 100 ret = of_dma_get_range(np, &map); 101 if (ret < 0) { 102 /* 103 * For legacy reasons, we have to assume some devices need 104 * DMA configuration regardless of whether "dma-ranges" is 105 * correctly specified or not. 106 */ 107 if (!force_dma) 108 return ret == -ENODEV ? 0 : ret; 109 } else { 110 const struct bus_dma_region *r = map; 111 dma_addr_t dma_end = 0; 112 113 /* Determine the overall bounds of all DMA regions */ 114 for (dma_start = ~(dma_addr_t)0; r->size; r++) { 115 /* Take lower and upper limits */ 116 if (r->dma_start < dma_start) 117 dma_start = r->dma_start; 118 if (r->dma_start + r->size > dma_end) 119 dma_end = r->dma_start + r->size; 120 } 121 size = dma_end - dma_start; 122 123 /* 124 * Add a work around to treat the size as mask + 1 in case 125 * it is defined in DT as a mask. 126 */ 127 if (size & 1) { 128 dev_warn(dev, "Invalid size 0x%llx for dma-range(s)\n", 129 size); 130 size = size + 1; 131 } 132 133 if (!size) { 134 dev_err(dev, "Adjusted size 0x%llx invalid\n", size); 135 kfree(map); 136 return -EINVAL; 137 } 138 } 139 140 /* 141 * If @dev is expected to be DMA-capable then the bus code that created 142 * it should have initialised its dma_mask pointer by this point. For 143 * now, we'll continue the legacy behaviour of coercing it to the 144 * coherent mask if not, but we'll no longer do so quietly. 145 */ 146 if (!dev->dma_mask) { 147 dev_warn(dev, "DMA mask not set\n"); 148 dev->dma_mask = &dev->coherent_dma_mask; 149 } 150 151 if (!size && dev->coherent_dma_mask) 152 size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); 153 else if (!size) 154 size = 1ULL << 32; 155 156 /* 157 * Limit coherent and dma mask based on size and default mask 158 * set by the driver. 159 */ 160 end = dma_start + size - 1; 161 mask = DMA_BIT_MASK(ilog2(end) + 1); 162 dev->coherent_dma_mask &= mask; 163 *dev->dma_mask &= mask; 164 /* ...but only set bus limit if we found valid dma-ranges earlier */ 165 if (!ret) 166 dev->bus_dma_limit = end; 167 168 coherent = of_dma_is_coherent(np); 169 dev_dbg(dev, "device is%sdma coherent\n", 170 coherent ? " " : " not "); 171 172 iommu = of_iommu_configure(dev, np, id); 173 if (PTR_ERR(iommu) == -EPROBE_DEFER) { 174 kfree(map); 175 return -EPROBE_DEFER; 176 } 177 178 dev_dbg(dev, "device is%sbehind an iommu\n", 179 iommu ? " " : " not "); 180 181 arch_setup_dma_ops(dev, dma_start, size, iommu, coherent); 182 183 dev->dma_range_map = map; 184 return 0; 185 } 186 EXPORT_SYMBOL_GPL(of_dma_configure_id); 187 188 int of_device_register(struct platform_device *pdev) 189 { 190 device_initialize(&pdev->dev); 191 return of_device_add(pdev); 192 } 193 EXPORT_SYMBOL(of_device_register); 194 195 void of_device_unregister(struct platform_device *ofdev) 196 { 197 device_unregister(&ofdev->dev); 198 } 199 EXPORT_SYMBOL(of_device_unregister); 200 201 const void *of_device_get_match_data(const struct device *dev) 202 { 203 const struct of_device_id *match; 204 205 match = of_match_device(dev->driver->of_match_table, dev); 206 if (!match) 207 return NULL; 208 209 return match->data; 210 } 211 EXPORT_SYMBOL(of_device_get_match_data); 212 213 static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len) 214 { 215 const char *compat; 216 char *c; 217 struct property *p; 218 ssize_t csize; 219 ssize_t tsize; 220 221 if ((!dev) || (!dev->of_node)) 222 return -ENODEV; 223 224 /* Name & Type */ 225 /* %p eats all alphanum characters, so %c must be used here */ 226 csize = snprintf(str, len, "of:N%pOFn%c%s", dev->of_node, 'T', 227 of_node_get_device_type(dev->of_node)); 228 tsize = csize; 229 len -= csize; 230 if (str) 231 str += csize; 232 233 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 234 csize = strlen(compat) + 1; 235 tsize += csize; 236 if (csize > len) 237 continue; 238 239 csize = snprintf(str, len, "C%s", compat); 240 for (c = str; c; ) { 241 c = strchr(c, ' '); 242 if (c) 243 *c++ = '_'; 244 } 245 len -= csize; 246 str += csize; 247 } 248 249 return tsize; 250 } 251 252 int of_device_request_module(struct device *dev) 253 { 254 char *str; 255 ssize_t size; 256 int ret; 257 258 size = of_device_get_modalias(dev, NULL, 0); 259 if (size < 0) 260 return size; 261 262 str = kmalloc(size + 1, GFP_KERNEL); 263 if (!str) 264 return -ENOMEM; 265 266 of_device_get_modalias(dev, str, size); 267 str[size] = '\0'; 268 ret = request_module(str); 269 kfree(str); 270 271 return ret; 272 } 273 EXPORT_SYMBOL_GPL(of_device_request_module); 274 275 /** 276 * of_device_modalias - Fill buffer with newline terminated modalias string 277 */ 278 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len) 279 { 280 ssize_t sl = of_device_get_modalias(dev, str, len - 2); 281 if (sl < 0) 282 return sl; 283 if (sl > len - 2) 284 return -ENOMEM; 285 286 str[sl++] = '\n'; 287 str[sl] = 0; 288 return sl; 289 } 290 EXPORT_SYMBOL_GPL(of_device_modalias); 291 292 /** 293 * of_device_uevent - Display OF related uevent information 294 */ 295 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env) 296 { 297 const char *compat, *type; 298 struct alias_prop *app; 299 struct property *p; 300 int seen = 0; 301 302 if ((!dev) || (!dev->of_node)) 303 return; 304 305 add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node); 306 add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node); 307 type = of_node_get_device_type(dev->of_node); 308 if (type) 309 add_uevent_var(env, "OF_TYPE=%s", type); 310 311 /* Since the compatible field can contain pretty much anything 312 * it's not really legal to split it out with commas. We split it 313 * up using a number of environment variables instead. */ 314 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 315 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat); 316 seen++; 317 } 318 add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen); 319 320 seen = 0; 321 mutex_lock(&of_mutex); 322 list_for_each_entry(app, &aliases_lookup, link) { 323 if (dev->of_node == app->np) { 324 add_uevent_var(env, "OF_ALIAS_%d=%s", seen, 325 app->alias); 326 seen++; 327 } 328 } 329 mutex_unlock(&of_mutex); 330 } 331 332 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env) 333 { 334 int sl; 335 336 if ((!dev) || (!dev->of_node)) 337 return -ENODEV; 338 339 /* Devicetree modalias is tricky, we add it in 2 steps */ 340 if (add_uevent_var(env, "MODALIAS=")) 341 return -ENOMEM; 342 343 sl = of_device_get_modalias(dev, &env->buf[env->buflen-1], 344 sizeof(env->buf) - env->buflen); 345 if (sl >= (sizeof(env->buf) - env->buflen)) 346 return -ENOMEM; 347 env->buflen += sl; 348 349 return 0; 350 } 351 EXPORT_SYMBOL_GPL(of_device_uevent_modalias); 352