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