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 * 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 mask = DMA_BIT_MASK(ilog2(dma_addr + size - 1) + 1); 152 dev->coherent_dma_mask &= mask; 153 *dev->dma_mask &= mask; 154 /* ...but only set bus mask if we found valid dma-ranges earlier */ 155 if (!ret) 156 dev->bus_dma_mask = mask; 157 158 coherent = of_dma_is_coherent(np); 159 dev_dbg(dev, "device is%sdma coherent\n", 160 coherent ? " " : " not "); 161 162 iommu = of_iommu_configure(dev, np); 163 if (IS_ERR(iommu) && PTR_ERR(iommu) == -EPROBE_DEFER) 164 return -EPROBE_DEFER; 165 166 dev_dbg(dev, "device is%sbehind an iommu\n", 167 iommu ? " " : " not "); 168 169 arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent); 170 171 return 0; 172 } 173 EXPORT_SYMBOL_GPL(of_dma_configure); 174 175 int of_device_register(struct platform_device *pdev) 176 { 177 device_initialize(&pdev->dev); 178 return of_device_add(pdev); 179 } 180 EXPORT_SYMBOL(of_device_register); 181 182 void of_device_unregister(struct platform_device *ofdev) 183 { 184 device_unregister(&ofdev->dev); 185 } 186 EXPORT_SYMBOL(of_device_unregister); 187 188 const void *of_device_get_match_data(const struct device *dev) 189 { 190 const struct of_device_id *match; 191 192 match = of_match_device(dev->driver->of_match_table, dev); 193 if (!match) 194 return NULL; 195 196 return match->data; 197 } 198 EXPORT_SYMBOL(of_device_get_match_data); 199 200 static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len) 201 { 202 const char *compat; 203 char *c; 204 struct property *p; 205 ssize_t csize; 206 ssize_t tsize; 207 208 if ((!dev) || (!dev->of_node)) 209 return -ENODEV; 210 211 /* Name & Type */ 212 /* %p eats all alphanum characters, so %c must be used here */ 213 csize = snprintf(str, len, "of:N%pOFn%c%s", dev->of_node, 'T', 214 of_node_get_device_type(dev->of_node)); 215 tsize = csize; 216 len -= csize; 217 if (str) 218 str += csize; 219 220 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 221 csize = strlen(compat) + 1; 222 tsize += csize; 223 if (csize > len) 224 continue; 225 226 csize = snprintf(str, len, "C%s", compat); 227 for (c = str; c; ) { 228 c = strchr(c, ' '); 229 if (c) 230 *c++ = '_'; 231 } 232 len -= csize; 233 str += csize; 234 } 235 236 return tsize; 237 } 238 239 int of_device_request_module(struct device *dev) 240 { 241 char *str; 242 ssize_t size; 243 int ret; 244 245 size = of_device_get_modalias(dev, NULL, 0); 246 if (size < 0) 247 return size; 248 249 str = kmalloc(size + 1, GFP_KERNEL); 250 if (!str) 251 return -ENOMEM; 252 253 of_device_get_modalias(dev, str, size); 254 str[size] = '\0'; 255 ret = request_module(str); 256 kfree(str); 257 258 return ret; 259 } 260 EXPORT_SYMBOL_GPL(of_device_request_module); 261 262 /** 263 * of_device_modalias - Fill buffer with newline terminated modalias string 264 */ 265 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len) 266 { 267 ssize_t sl = of_device_get_modalias(dev, str, len - 2); 268 if (sl < 0) 269 return sl; 270 if (sl > len - 2) 271 return -ENOMEM; 272 273 str[sl++] = '\n'; 274 str[sl] = 0; 275 return sl; 276 } 277 EXPORT_SYMBOL_GPL(of_device_modalias); 278 279 /** 280 * of_device_uevent - Display OF related uevent information 281 */ 282 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env) 283 { 284 const char *compat, *type; 285 struct alias_prop *app; 286 struct property *p; 287 int seen = 0; 288 289 if ((!dev) || (!dev->of_node)) 290 return; 291 292 add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node); 293 add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node); 294 type = of_node_get_device_type(dev->of_node); 295 if (type) 296 add_uevent_var(env, "OF_TYPE=%s", type); 297 298 /* Since the compatible field can contain pretty much anything 299 * it's not really legal to split it out with commas. We split it 300 * up using a number of environment variables instead. */ 301 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 302 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat); 303 seen++; 304 } 305 add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen); 306 307 seen = 0; 308 mutex_lock(&of_mutex); 309 list_for_each_entry(app, &aliases_lookup, link) { 310 if (dev->of_node == app->np) { 311 add_uevent_var(env, "OF_ALIAS_%d=%s", seen, 312 app->alias); 313 seen++; 314 } 315 } 316 mutex_unlock(&of_mutex); 317 } 318 319 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env) 320 { 321 int sl; 322 323 if ((!dev) || (!dev->of_node)) 324 return -ENODEV; 325 326 /* Devicetree modalias is tricky, we add it in 2 steps */ 327 if (add_uevent_var(env, "MODALIAS=")) 328 return -ENOMEM; 329 330 sl = of_device_get_modalias(dev, &env->buf[env->buflen-1], 331 sizeof(env->buf) - env->buflen); 332 if (sl >= (sizeof(env->buf) - env->buflen)) 333 return -ENOMEM; 334 env->buflen += sl; 335 336 return 0; 337 } 338 EXPORT_SYMBOL_GPL(of_device_uevent_modalias); 339