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 * @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 u64 dma_addr, paddr, size = 0; 94 int ret; 95 bool coherent; 96 unsigned long offset; 97 const struct iommu_ops *iommu; 98 u64 mask, end; 99 100 ret = of_dma_get_range(np, &dma_addr, &paddr, &size); 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; 109 110 dma_addr = offset = 0; 111 } else { 112 offset = PFN_DOWN(paddr - dma_addr); 113 114 /* 115 * Add a work around to treat the size as mask + 1 in case 116 * it is defined in DT as a mask. 117 */ 118 if (size & 1) { 119 dev_warn(dev, "Invalid size 0x%llx for dma-range\n", 120 size); 121 size = size + 1; 122 } 123 124 if (!size) { 125 dev_err(dev, "Adjusted size 0x%llx invalid\n", size); 126 return -EINVAL; 127 } 128 dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset); 129 } 130 131 /* 132 * If @dev is expected to be DMA-capable then the bus code that created 133 * it should have initialised its dma_mask pointer by this point. For 134 * now, we'll continue the legacy behaviour of coercing it to the 135 * coherent mask if not, but we'll no longer do so quietly. 136 */ 137 if (!dev->dma_mask) { 138 dev_warn(dev, "DMA mask not set\n"); 139 dev->dma_mask = &dev->coherent_dma_mask; 140 } 141 142 if (!size && dev->coherent_dma_mask) 143 size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); 144 else if (!size) 145 size = 1ULL << 32; 146 147 dev->dma_pfn_offset = offset; 148 149 /* 150 * Limit coherent and dma mask based on size and default mask 151 * set by the driver. 152 */ 153 end = dma_addr + size - 1; 154 mask = DMA_BIT_MASK(ilog2(end) + 1); 155 dev->coherent_dma_mask &= mask; 156 *dev->dma_mask &= mask; 157 /* ...but only set bus limit if we found valid dma-ranges earlier */ 158 if (!ret) 159 dev->bus_dma_limit = end; 160 161 coherent = of_dma_is_coherent(np); 162 dev_dbg(dev, "device is%sdma coherent\n", 163 coherent ? " " : " not "); 164 165 iommu = of_iommu_configure(dev, np, id); 166 if (PTR_ERR(iommu) == -EPROBE_DEFER) 167 return -EPROBE_DEFER; 168 169 dev_dbg(dev, "device is%sbehind an iommu\n", 170 iommu ? " " : " not "); 171 172 arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent); 173 174 return 0; 175 } 176 EXPORT_SYMBOL_GPL(of_dma_configure_id); 177 178 int of_device_register(struct platform_device *pdev) 179 { 180 device_initialize(&pdev->dev); 181 return of_device_add(pdev); 182 } 183 EXPORT_SYMBOL(of_device_register); 184 185 void of_device_unregister(struct platform_device *ofdev) 186 { 187 device_unregister(&ofdev->dev); 188 } 189 EXPORT_SYMBOL(of_device_unregister); 190 191 const void *of_device_get_match_data(const struct device *dev) 192 { 193 const struct of_device_id *match; 194 195 match = of_match_device(dev->driver->of_match_table, dev); 196 if (!match) 197 return NULL; 198 199 return match->data; 200 } 201 EXPORT_SYMBOL(of_device_get_match_data); 202 203 static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len) 204 { 205 const char *compat; 206 char *c; 207 struct property *p; 208 ssize_t csize; 209 ssize_t tsize; 210 211 if ((!dev) || (!dev->of_node)) 212 return -ENODEV; 213 214 /* Name & Type */ 215 /* %p eats all alphanum characters, so %c must be used here */ 216 csize = snprintf(str, len, "of:N%pOFn%c%s", dev->of_node, 'T', 217 of_node_get_device_type(dev->of_node)); 218 tsize = csize; 219 len -= csize; 220 if (str) 221 str += csize; 222 223 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 224 csize = strlen(compat) + 1; 225 tsize += csize; 226 if (csize > len) 227 continue; 228 229 csize = snprintf(str, len, "C%s", compat); 230 for (c = str; c; ) { 231 c = strchr(c, ' '); 232 if (c) 233 *c++ = '_'; 234 } 235 len -= csize; 236 str += csize; 237 } 238 239 return tsize; 240 } 241 242 int of_device_request_module(struct device *dev) 243 { 244 char *str; 245 ssize_t size; 246 int ret; 247 248 size = of_device_get_modalias(dev, NULL, 0); 249 if (size < 0) 250 return size; 251 252 str = kmalloc(size + 1, GFP_KERNEL); 253 if (!str) 254 return -ENOMEM; 255 256 of_device_get_modalias(dev, str, size); 257 str[size] = '\0'; 258 ret = request_module(str); 259 kfree(str); 260 261 return ret; 262 } 263 EXPORT_SYMBOL_GPL(of_device_request_module); 264 265 /** 266 * of_device_modalias - Fill buffer with newline terminated modalias string 267 */ 268 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len) 269 { 270 ssize_t sl = of_device_get_modalias(dev, str, len - 2); 271 if (sl < 0) 272 return sl; 273 if (sl > len - 2) 274 return -ENOMEM; 275 276 str[sl++] = '\n'; 277 str[sl] = 0; 278 return sl; 279 } 280 EXPORT_SYMBOL_GPL(of_device_modalias); 281 282 /** 283 * of_device_uevent - Display OF related uevent information 284 */ 285 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env) 286 { 287 const char *compat, *type; 288 struct alias_prop *app; 289 struct property *p; 290 int seen = 0; 291 292 if ((!dev) || (!dev->of_node)) 293 return; 294 295 add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node); 296 add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node); 297 type = of_node_get_device_type(dev->of_node); 298 if (type) 299 add_uevent_var(env, "OF_TYPE=%s", type); 300 301 /* Since the compatible field can contain pretty much anything 302 * it's not really legal to split it out with commas. We split it 303 * up using a number of environment variables instead. */ 304 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 305 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat); 306 seen++; 307 } 308 add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen); 309 310 seen = 0; 311 mutex_lock(&of_mutex); 312 list_for_each_entry(app, &aliases_lookup, link) { 313 if (dev->of_node == app->np) { 314 add_uevent_var(env, "OF_ALIAS_%d=%s", seen, 315 app->alias); 316 seen++; 317 } 318 } 319 mutex_unlock(&of_mutex); 320 } 321 322 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env) 323 { 324 int sl; 325 326 if ((!dev) || (!dev->of_node)) 327 return -ENODEV; 328 329 /* Devicetree modalias is tricky, we add it in 2 steps */ 330 if (add_uevent_var(env, "MODALIAS=")) 331 return -ENOMEM; 332 333 sl = of_device_get_modalias(dev, &env->buf[env->buflen-1], 334 sizeof(env->buf) - env->buflen); 335 if (sl >= (sizeof(env->buf) - env->buflen)) 336 return -ENOMEM; 337 env->buflen += sl; 338 339 return 0; 340 } 341 EXPORT_SYMBOL_GPL(of_device_uevent_modalias); 342