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/dma-map-ops.h> 10 #include <linux/init.h> 11 #include <linux/module.h> 12 #include <linux/mod_devicetable.h> 13 #include <linux/slab.h> 14 #include <linux/platform_device.h> 15 16 #include <asm/errno.h> 17 #include "of_private.h" 18 19 /** 20 * of_match_device - Tell if a struct device matches an of_device_id list 21 * @matches: array of of device match structures to search in 22 * @dev: the of device structure to match against 23 * 24 * Used by a driver to check whether an platform_device present in the 25 * system is in its list of supported devices. 26 */ 27 const struct of_device_id *of_match_device(const struct of_device_id *matches, 28 const struct device *dev) 29 { 30 if ((!matches) || (!dev->of_node)) 31 return NULL; 32 return of_match_node(matches, dev->of_node); 33 } 34 EXPORT_SYMBOL(of_match_device); 35 36 struct platform_device *of_dev_get(struct platform_device *dev) 37 { 38 struct device *tmp; 39 40 if (!dev) 41 return NULL; 42 tmp = get_device(&dev->dev); 43 if (tmp) 44 return to_platform_device(tmp); 45 else 46 return NULL; 47 } 48 EXPORT_SYMBOL(of_dev_get); 49 50 void of_dev_put(struct platform_device *dev) 51 { 52 if (dev) 53 put_device(&dev->dev); 54 } 55 EXPORT_SYMBOL(of_dev_put); 56 57 int of_device_add(struct platform_device *ofdev) 58 { 59 BUG_ON(ofdev->dev.of_node == NULL); 60 61 /* name and id have to be set so that the platform bus doesn't get 62 * confused on matching */ 63 ofdev->name = dev_name(&ofdev->dev); 64 ofdev->id = PLATFORM_DEVID_NONE; 65 66 /* 67 * If this device has not binding numa node in devicetree, that is 68 * of_node_to_nid returns NUMA_NO_NODE. device_add will assume that this 69 * device is on the same node as the parent. 70 */ 71 set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node)); 72 73 return device_add(&ofdev->dev); 74 } 75 76 /** 77 * of_dma_configure - Setup DMA configuration 78 * @dev: Device to apply DMA configuration 79 * @np: Pointer to OF node having DMA configuration 80 * @force_dma: Whether device is to be set up by of_dma_configure() even if 81 * DMA capability is not explicitly described by firmware. 82 * @id: Optional const pointer value input id 83 * 84 * Try to get devices's DMA configuration from DT and update it 85 * accordingly. 86 * 87 * If platform code needs to use its own special DMA configuration, it 88 * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events 89 * to fix up DMA configuration. 90 */ 91 int of_dma_configure_id(struct device *dev, struct device_node *np, 92 bool force_dma, const u32 *id) 93 { 94 const struct iommu_ops *iommu; 95 const struct bus_dma_region *map = NULL; 96 u64 dma_start = 0; 97 u64 mask, end, size = 0; 98 bool coherent; 99 int ret; 100 101 ret = of_dma_get_range(np, &map); 102 if (ret < 0) { 103 /* 104 * For legacy reasons, we have to assume some devices need 105 * DMA configuration regardless of whether "dma-ranges" is 106 * correctly specified or not. 107 */ 108 if (!force_dma) 109 return ret == -ENODEV ? 0 : ret; 110 } else { 111 const struct bus_dma_region *r = map; 112 u64 dma_end = 0; 113 114 /* Determine the overall bounds of all DMA regions */ 115 for (dma_start = ~0; r->size; r++) { 116 /* Take lower and upper limits */ 117 if (r->dma_start < dma_start) 118 dma_start = r->dma_start; 119 if (r->dma_start + r->size > dma_end) 120 dma_end = r->dma_start + r->size; 121 } 122 size = dma_end - dma_start; 123 124 /* 125 * Add a work around to treat the size as mask + 1 in case 126 * it is defined in DT as a mask. 127 */ 128 if (size & 1) { 129 dev_warn(dev, "Invalid size 0x%llx for dma-range(s)\n", 130 size); 131 size = size + 1; 132 } 133 134 if (!size) { 135 dev_err(dev, "Adjusted size 0x%llx invalid\n", size); 136 kfree(map); 137 return -EINVAL; 138 } 139 } 140 141 /* 142 * If @dev is expected to be DMA-capable then the bus code that created 143 * it should have initialised its dma_mask pointer by this point. For 144 * now, we'll continue the legacy behaviour of coercing it to the 145 * coherent mask if not, but we'll no longer do so quietly. 146 */ 147 if (!dev->dma_mask) { 148 dev_warn(dev, "DMA mask not set\n"); 149 dev->dma_mask = &dev->coherent_dma_mask; 150 } 151 152 if (!size && dev->coherent_dma_mask) 153 size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); 154 else if (!size) 155 size = 1ULL << 32; 156 157 /* 158 * Limit coherent and dma mask based on size and default mask 159 * set by the driver. 160 */ 161 end = dma_start + size - 1; 162 mask = DMA_BIT_MASK(ilog2(end) + 1); 163 dev->coherent_dma_mask &= mask; 164 *dev->dma_mask &= mask; 165 /* ...but only set bus limit and range map if we found valid dma-ranges earlier */ 166 if (!ret) { 167 dev->bus_dma_limit = end; 168 dev->dma_range_map = map; 169 } 170 171 coherent = of_dma_is_coherent(np); 172 dev_dbg(dev, "device is%sdma coherent\n", 173 coherent ? " " : " not "); 174 175 iommu = of_iommu_configure(dev, np, id); 176 if (PTR_ERR(iommu) == -EPROBE_DEFER) { 177 /* Don't touch range map if it wasn't set from a valid dma-ranges */ 178 if (!ret) 179 dev->dma_range_map = NULL; 180 kfree(map); 181 return -EPROBE_DEFER; 182 } 183 184 dev_dbg(dev, "device is%sbehind an iommu\n", 185 iommu ? " " : " not "); 186 187 arch_setup_dma_ops(dev, dma_start, size, iommu, coherent); 188 189 return 0; 190 } 191 EXPORT_SYMBOL_GPL(of_dma_configure_id); 192 193 int of_device_register(struct platform_device *pdev) 194 { 195 device_initialize(&pdev->dev); 196 return of_device_add(pdev); 197 } 198 EXPORT_SYMBOL(of_device_register); 199 200 void of_device_unregister(struct platform_device *ofdev) 201 { 202 device_unregister(&ofdev->dev); 203 } 204 EXPORT_SYMBOL(of_device_unregister); 205 206 const void *of_device_get_match_data(const struct device *dev) 207 { 208 const struct of_device_id *match; 209 210 match = of_match_device(dev->driver->of_match_table, dev); 211 if (!match) 212 return NULL; 213 214 return match->data; 215 } 216 EXPORT_SYMBOL(of_device_get_match_data); 217 218 static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len) 219 { 220 const char *compat; 221 char *c; 222 struct property *p; 223 ssize_t csize; 224 ssize_t tsize; 225 226 if ((!dev) || (!dev->of_node)) 227 return -ENODEV; 228 229 /* Name & Type */ 230 /* %p eats all alphanum characters, so %c must be used here */ 231 csize = snprintf(str, len, "of:N%pOFn%c%s", dev->of_node, 'T', 232 of_node_get_device_type(dev->of_node)); 233 tsize = csize; 234 len -= csize; 235 if (str) 236 str += csize; 237 238 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 239 csize = strlen(compat) + 1; 240 tsize += csize; 241 if (csize > len) 242 continue; 243 244 csize = snprintf(str, len, "C%s", compat); 245 for (c = str; c; ) { 246 c = strchr(c, ' '); 247 if (c) 248 *c++ = '_'; 249 } 250 len -= csize; 251 str += csize; 252 } 253 254 return tsize; 255 } 256 257 int of_device_request_module(struct device *dev) 258 { 259 char *str; 260 ssize_t size; 261 int ret; 262 263 size = of_device_get_modalias(dev, NULL, 0); 264 if (size < 0) 265 return size; 266 267 str = kmalloc(size + 1, GFP_KERNEL); 268 if (!str) 269 return -ENOMEM; 270 271 of_device_get_modalias(dev, str, size); 272 str[size] = '\0'; 273 ret = request_module(str); 274 kfree(str); 275 276 return ret; 277 } 278 EXPORT_SYMBOL_GPL(of_device_request_module); 279 280 /** 281 * of_device_modalias - Fill buffer with newline terminated modalias string 282 */ 283 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len) 284 { 285 ssize_t sl = of_device_get_modalias(dev, str, len - 2); 286 if (sl < 0) 287 return sl; 288 if (sl > len - 2) 289 return -ENOMEM; 290 291 str[sl++] = '\n'; 292 str[sl] = 0; 293 return sl; 294 } 295 EXPORT_SYMBOL_GPL(of_device_modalias); 296 297 /** 298 * of_device_uevent - Display OF related uevent information 299 */ 300 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env) 301 { 302 const char *compat, *type; 303 struct alias_prop *app; 304 struct property *p; 305 int seen = 0; 306 307 if ((!dev) || (!dev->of_node)) 308 return; 309 310 add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node); 311 add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node); 312 type = of_node_get_device_type(dev->of_node); 313 if (type) 314 add_uevent_var(env, "OF_TYPE=%s", type); 315 316 /* Since the compatible field can contain pretty much anything 317 * it's not really legal to split it out with commas. We split it 318 * up using a number of environment variables instead. */ 319 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 320 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat); 321 seen++; 322 } 323 add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen); 324 325 seen = 0; 326 mutex_lock(&of_mutex); 327 list_for_each_entry(app, &aliases_lookup, link) { 328 if (dev->of_node == app->np) { 329 add_uevent_var(env, "OF_ALIAS_%d=%s", seen, 330 app->alias); 331 seen++; 332 } 333 } 334 mutex_unlock(&of_mutex); 335 } 336 337 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env) 338 { 339 int sl; 340 341 if ((!dev) || (!dev->of_node)) 342 return -ENODEV; 343 344 /* Devicetree modalias is tricky, we add it in 2 steps */ 345 if (add_uevent_var(env, "MODALIAS=")) 346 return -ENOMEM; 347 348 sl = of_device_get_modalias(dev, &env->buf[env->buflen-1], 349 sizeof(env->buf) - env->buflen); 350 if (sl >= (sizeof(env->buf) - env->buflen)) 351 return -ENOMEM; 352 env->buflen += sl; 353 354 return 0; 355 } 356 EXPORT_SYMBOL_GPL(of_device_uevent_modalias); 357