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 if we found valid dma-ranges earlier */ 166 if (!ret) 167 dev->bus_dma_limit = end; 168 169 coherent = of_dma_is_coherent(np); 170 dev_dbg(dev, "device is%sdma coherent\n", 171 coherent ? " " : " not "); 172 173 iommu = of_iommu_configure(dev, np, id); 174 if (PTR_ERR(iommu) == -EPROBE_DEFER) { 175 kfree(map); 176 return -EPROBE_DEFER; 177 } 178 179 dev_dbg(dev, "device is%sbehind an iommu\n", 180 iommu ? " " : " not "); 181 182 arch_setup_dma_ops(dev, dma_start, size, iommu, coherent); 183 184 dev->dma_range_map = map; 185 return 0; 186 } 187 EXPORT_SYMBOL_GPL(of_dma_configure_id); 188 189 int of_device_register(struct platform_device *pdev) 190 { 191 device_initialize(&pdev->dev); 192 return of_device_add(pdev); 193 } 194 EXPORT_SYMBOL(of_device_register); 195 196 void of_device_unregister(struct platform_device *ofdev) 197 { 198 device_unregister(&ofdev->dev); 199 } 200 EXPORT_SYMBOL(of_device_unregister); 201 202 const void *of_device_get_match_data(const struct device *dev) 203 { 204 const struct of_device_id *match; 205 206 match = of_match_device(dev->driver->of_match_table, dev); 207 if (!match) 208 return NULL; 209 210 return match->data; 211 } 212 EXPORT_SYMBOL(of_device_get_match_data); 213 214 static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len) 215 { 216 const char *compat; 217 char *c; 218 struct property *p; 219 ssize_t csize; 220 ssize_t tsize; 221 222 if ((!dev) || (!dev->of_node)) 223 return -ENODEV; 224 225 /* Name & Type */ 226 /* %p eats all alphanum characters, so %c must be used here */ 227 csize = snprintf(str, len, "of:N%pOFn%c%s", dev->of_node, 'T', 228 of_node_get_device_type(dev->of_node)); 229 tsize = csize; 230 len -= csize; 231 if (str) 232 str += csize; 233 234 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 235 csize = strlen(compat) + 1; 236 tsize += csize; 237 if (csize > len) 238 continue; 239 240 csize = snprintf(str, len, "C%s", compat); 241 for (c = str; c; ) { 242 c = strchr(c, ' '); 243 if (c) 244 *c++ = '_'; 245 } 246 len -= csize; 247 str += csize; 248 } 249 250 return tsize; 251 } 252 253 int of_device_request_module(struct device *dev) 254 { 255 char *str; 256 ssize_t size; 257 int ret; 258 259 size = of_device_get_modalias(dev, NULL, 0); 260 if (size < 0) 261 return size; 262 263 str = kmalloc(size + 1, GFP_KERNEL); 264 if (!str) 265 return -ENOMEM; 266 267 of_device_get_modalias(dev, str, size); 268 str[size] = '\0'; 269 ret = request_module(str); 270 kfree(str); 271 272 return ret; 273 } 274 EXPORT_SYMBOL_GPL(of_device_request_module); 275 276 /** 277 * of_device_modalias - Fill buffer with newline terminated modalias string 278 */ 279 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len) 280 { 281 ssize_t sl = of_device_get_modalias(dev, str, len - 2); 282 if (sl < 0) 283 return sl; 284 if (sl > len - 2) 285 return -ENOMEM; 286 287 str[sl++] = '\n'; 288 str[sl] = 0; 289 return sl; 290 } 291 EXPORT_SYMBOL_GPL(of_device_modalias); 292 293 /** 294 * of_device_uevent - Display OF related uevent information 295 */ 296 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env) 297 { 298 const char *compat, *type; 299 struct alias_prop *app; 300 struct property *p; 301 int seen = 0; 302 303 if ((!dev) || (!dev->of_node)) 304 return; 305 306 add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node); 307 add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node); 308 type = of_node_get_device_type(dev->of_node); 309 if (type) 310 add_uevent_var(env, "OF_TYPE=%s", type); 311 312 /* Since the compatible field can contain pretty much anything 313 * it's not really legal to split it out with commas. We split it 314 * up using a number of environment variables instead. */ 315 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 316 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat); 317 seen++; 318 } 319 add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen); 320 321 seen = 0; 322 mutex_lock(&of_mutex); 323 list_for_each_entry(app, &aliases_lookup, link) { 324 if (dev->of_node == app->np) { 325 add_uevent_var(env, "OF_ALIAS_%d=%s", seen, 326 app->alias); 327 seen++; 328 } 329 } 330 mutex_unlock(&of_mutex); 331 } 332 333 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env) 334 { 335 int sl; 336 337 if ((!dev) || (!dev->of_node)) 338 return -ENODEV; 339 340 /* Devicetree modalias is tricky, we add it in 2 steps */ 341 if (add_uevent_var(env, "MODALIAS=")) 342 return -ENOMEM; 343 344 sl = of_device_get_modalias(dev, &env->buf[env->buflen-1], 345 sizeof(env->buf) - env->buflen); 346 if (sl >= (sizeof(env->buf) - env->buflen)) 347 return -ENOMEM; 348 env->buflen += sl; 349 350 return 0; 351 } 352 EXPORT_SYMBOL_GPL(of_device_uevent_modalias); 353