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 * Set default coherent_dma_mask to 32 bit. Drivers are expected to 131 * setup the correct supported mask. 132 */ 133 if (!dev->coherent_dma_mask) 134 dev->coherent_dma_mask = DMA_BIT_MASK(32); 135 /* 136 * Set it to coherent_dma_mask by default if the architecture 137 * code has not set it. 138 */ 139 if (!dev->dma_mask) 140 dev->dma_mask = &dev->coherent_dma_mask; 141 142 if (!size) 143 size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); 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->coherent_dma_mask &= mask; 153 *dev->dma_mask &= mask; 154 155 coherent = of_dma_is_coherent(np); 156 dev_dbg(dev, "device is%sdma coherent\n", 157 coherent ? " " : " not "); 158 159 iommu = of_iommu_configure(dev, np); 160 if (IS_ERR(iommu) && PTR_ERR(iommu) == -EPROBE_DEFER) 161 return -EPROBE_DEFER; 162 163 dev_dbg(dev, "device is%sbehind an iommu\n", 164 iommu ? " " : " not "); 165 166 arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent); 167 168 return 0; 169 } 170 EXPORT_SYMBOL_GPL(of_dma_configure); 171 172 /** 173 * of_dma_deconfigure - Clean up DMA configuration 174 * @dev: Device for which to clean up DMA configuration 175 * 176 * Clean up all configuration performed by of_dma_configure_ops() and free all 177 * resources that have been allocated. 178 */ 179 void of_dma_deconfigure(struct device *dev) 180 { 181 arch_teardown_dma_ops(dev); 182 } 183 184 int of_device_register(struct platform_device *pdev) 185 { 186 device_initialize(&pdev->dev); 187 return of_device_add(pdev); 188 } 189 EXPORT_SYMBOL(of_device_register); 190 191 void of_device_unregister(struct platform_device *ofdev) 192 { 193 device_unregister(&ofdev->dev); 194 } 195 EXPORT_SYMBOL(of_device_unregister); 196 197 const void *of_device_get_match_data(const struct device *dev) 198 { 199 const struct of_device_id *match; 200 201 match = of_match_device(dev->driver->of_match_table, dev); 202 if (!match) 203 return NULL; 204 205 return match->data; 206 } 207 EXPORT_SYMBOL(of_device_get_match_data); 208 209 static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len) 210 { 211 const char *compat; 212 char *c; 213 struct property *p; 214 ssize_t csize; 215 ssize_t tsize; 216 217 if ((!dev) || (!dev->of_node)) 218 return -ENODEV; 219 220 /* Name & Type */ 221 csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name, 222 dev->of_node->type); 223 tsize = csize; 224 len -= csize; 225 if (str) 226 str += csize; 227 228 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 229 csize = strlen(compat) + 1; 230 tsize += csize; 231 if (csize > len) 232 continue; 233 234 csize = snprintf(str, len, "C%s", compat); 235 for (c = str; c; ) { 236 c = strchr(c, ' '); 237 if (c) 238 *c++ = '_'; 239 } 240 len -= csize; 241 str += csize; 242 } 243 244 return tsize; 245 } 246 247 int of_device_request_module(struct device *dev) 248 { 249 char *str; 250 ssize_t size; 251 int ret; 252 253 size = of_device_get_modalias(dev, NULL, 0); 254 if (size < 0) 255 return size; 256 257 str = kmalloc(size + 1, GFP_KERNEL); 258 if (!str) 259 return -ENOMEM; 260 261 of_device_get_modalias(dev, str, size); 262 str[size] = '\0'; 263 ret = request_module(str); 264 kfree(str); 265 266 return ret; 267 } 268 EXPORT_SYMBOL_GPL(of_device_request_module); 269 270 /** 271 * of_device_modalias - Fill buffer with newline terminated modalias string 272 */ 273 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len) 274 { 275 ssize_t sl = of_device_get_modalias(dev, str, len - 2); 276 if (sl < 0) 277 return sl; 278 if (sl > len - 2) 279 return -ENOMEM; 280 281 str[sl++] = '\n'; 282 str[sl] = 0; 283 return sl; 284 } 285 EXPORT_SYMBOL_GPL(of_device_modalias); 286 287 /** 288 * of_device_uevent - Display OF related uevent information 289 */ 290 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env) 291 { 292 const char *compat; 293 struct alias_prop *app; 294 struct property *p; 295 int seen = 0; 296 297 if ((!dev) || (!dev->of_node)) 298 return; 299 300 add_uevent_var(env, "OF_NAME=%s", dev->of_node->name); 301 add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node); 302 if (dev->of_node->type && strcmp("<NULL>", dev->of_node->type) != 0) 303 add_uevent_var(env, "OF_TYPE=%s", dev->of_node->type); 304 305 /* Since the compatible field can contain pretty much anything 306 * it's not really legal to split it out with commas. We split it 307 * up using a number of environment variables instead. */ 308 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 309 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat); 310 seen++; 311 } 312 add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen); 313 314 seen = 0; 315 mutex_lock(&of_mutex); 316 list_for_each_entry(app, &aliases_lookup, link) { 317 if (dev->of_node == app->np) { 318 add_uevent_var(env, "OF_ALIAS_%d=%s", seen, 319 app->alias); 320 seen++; 321 } 322 } 323 mutex_unlock(&of_mutex); 324 } 325 326 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env) 327 { 328 int sl; 329 330 if ((!dev) || (!dev->of_node)) 331 return -ENODEV; 332 333 /* Devicetree modalias is tricky, we add it in 2 steps */ 334 if (add_uevent_var(env, "MODALIAS=")) 335 return -ENOMEM; 336 337 sl = of_device_get_modalias(dev, &env->buf[env->buflen-1], 338 sizeof(env->buf) - env->buflen); 339 if (sl >= (sizeof(env->buf) - env->buflen)) 340 return -ENOMEM; 341 env->buflen += sl; 342 343 return 0; 344 } 345 EXPORT_SYMBOL_GPL(of_device_uevent_modalias); 346