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 int of_device_add(struct platform_device *ofdev) 37 { 38 BUG_ON(ofdev->dev.of_node == NULL); 39 40 /* name and id have to be set so that the platform bus doesn't get 41 * confused on matching */ 42 ofdev->name = dev_name(&ofdev->dev); 43 ofdev->id = PLATFORM_DEVID_NONE; 44 45 /* 46 * If this device has not binding numa node in devicetree, that is 47 * of_node_to_nid returns NUMA_NO_NODE. device_add will assume that this 48 * device is on the same node as the parent. 49 */ 50 set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node)); 51 52 return device_add(&ofdev->dev); 53 } 54 55 /** 56 * of_dma_configure - Setup DMA configuration 57 * @dev: Device to apply DMA configuration 58 * @np: Pointer to OF node having DMA configuration 59 * @force_dma: Whether device is to be set up by of_dma_configure() even if 60 * DMA capability is not explicitly described by firmware. 61 * @id: Optional const pointer value input id 62 * 63 * Try to get devices's DMA configuration from DT and update it 64 * accordingly. 65 * 66 * If platform code needs to use its own special DMA configuration, it 67 * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events 68 * to fix up DMA configuration. 69 */ 70 int of_dma_configure_id(struct device *dev, struct device_node *np, 71 bool force_dma, const u32 *id) 72 { 73 const struct iommu_ops *iommu; 74 const struct bus_dma_region *map = NULL; 75 u64 dma_start = 0; 76 u64 mask, end, size = 0; 77 bool coherent; 78 int ret; 79 80 ret = of_dma_get_range(np, &map); 81 if (ret < 0) { 82 /* 83 * For legacy reasons, we have to assume some devices need 84 * DMA configuration regardless of whether "dma-ranges" is 85 * correctly specified or not. 86 */ 87 if (!force_dma) 88 return ret == -ENODEV ? 0 : ret; 89 } else { 90 const struct bus_dma_region *r = map; 91 u64 dma_end = 0; 92 93 /* Determine the overall bounds of all DMA regions */ 94 for (dma_start = ~0; r->size; r++) { 95 /* Take lower and upper limits */ 96 if (r->dma_start < dma_start) 97 dma_start = r->dma_start; 98 if (r->dma_start + r->size > dma_end) 99 dma_end = r->dma_start + r->size; 100 } 101 size = dma_end - dma_start; 102 103 /* 104 * Add a work around to treat the size as mask + 1 in case 105 * it is defined in DT as a mask. 106 */ 107 if (size & 1) { 108 dev_warn(dev, "Invalid size 0x%llx for dma-range(s)\n", 109 size); 110 size = size + 1; 111 } 112 113 if (!size) { 114 dev_err(dev, "Adjusted size 0x%llx invalid\n", size); 115 kfree(map); 116 return -EINVAL; 117 } 118 } 119 120 /* 121 * If @dev is expected to be DMA-capable then the bus code that created 122 * it should have initialised its dma_mask pointer by this point. For 123 * now, we'll continue the legacy behaviour of coercing it to the 124 * coherent mask if not, but we'll no longer do so quietly. 125 */ 126 if (!dev->dma_mask) { 127 dev_warn(dev, "DMA mask not set\n"); 128 dev->dma_mask = &dev->coherent_dma_mask; 129 } 130 131 if (!size && dev->coherent_dma_mask) 132 size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); 133 else if (!size) 134 size = 1ULL << 32; 135 136 /* 137 * Limit coherent and dma mask based on size and default mask 138 * set by the driver. 139 */ 140 end = dma_start + size - 1; 141 mask = DMA_BIT_MASK(ilog2(end) + 1); 142 dev->coherent_dma_mask &= mask; 143 *dev->dma_mask &= mask; 144 /* ...but only set bus limit and range map if we found valid dma-ranges earlier */ 145 if (!ret) { 146 dev->bus_dma_limit = end; 147 dev->dma_range_map = map; 148 } 149 150 coherent = of_dma_is_coherent(np); 151 dev_dbg(dev, "device is%sdma coherent\n", 152 coherent ? " " : " not "); 153 154 iommu = of_iommu_configure(dev, np, id); 155 if (PTR_ERR(iommu) == -EPROBE_DEFER) { 156 /* Don't touch range map if it wasn't set from a valid dma-ranges */ 157 if (!ret) 158 dev->dma_range_map = NULL; 159 kfree(map); 160 return -EPROBE_DEFER; 161 } 162 163 dev_dbg(dev, "device is%sbehind an iommu\n", 164 iommu ? " " : " not "); 165 166 arch_setup_dma_ops(dev, dma_start, size, iommu, coherent); 167 168 return 0; 169 } 170 EXPORT_SYMBOL_GPL(of_dma_configure_id); 171 172 int of_device_register(struct platform_device *pdev) 173 { 174 device_initialize(&pdev->dev); 175 return of_device_add(pdev); 176 } 177 EXPORT_SYMBOL(of_device_register); 178 179 void of_device_unregister(struct platform_device *ofdev) 180 { 181 device_unregister(&ofdev->dev); 182 } 183 EXPORT_SYMBOL(of_device_unregister); 184 185 const void *of_device_get_match_data(const struct device *dev) 186 { 187 const struct of_device_id *match; 188 189 match = of_match_device(dev->driver->of_match_table, dev); 190 if (!match) 191 return NULL; 192 193 return match->data; 194 } 195 EXPORT_SYMBOL(of_device_get_match_data); 196 197 static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len) 198 { 199 const char *compat; 200 char *c; 201 struct property *p; 202 ssize_t csize; 203 ssize_t tsize; 204 205 if ((!dev) || (!dev->of_node)) 206 return -ENODEV; 207 208 /* Name & Type */ 209 /* %p eats all alphanum characters, so %c must be used here */ 210 csize = snprintf(str, len, "of:N%pOFn%c%s", dev->of_node, 'T', 211 of_node_get_device_type(dev->of_node)); 212 tsize = csize; 213 len -= csize; 214 if (str) 215 str += csize; 216 217 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 218 csize = strlen(compat) + 1; 219 tsize += csize; 220 if (csize > len) 221 continue; 222 223 csize = snprintf(str, len, "C%s", compat); 224 for (c = str; c; ) { 225 c = strchr(c, ' '); 226 if (c) 227 *c++ = '_'; 228 } 229 len -= csize; 230 str += csize; 231 } 232 233 return tsize; 234 } 235 236 int of_device_request_module(struct device *dev) 237 { 238 char *str; 239 ssize_t size; 240 int ret; 241 242 size = of_device_get_modalias(dev, NULL, 0); 243 if (size < 0) 244 return size; 245 246 str = kmalloc(size + 1, GFP_KERNEL); 247 if (!str) 248 return -ENOMEM; 249 250 of_device_get_modalias(dev, str, size); 251 str[size] = '\0'; 252 ret = request_module(str); 253 kfree(str); 254 255 return ret; 256 } 257 EXPORT_SYMBOL_GPL(of_device_request_module); 258 259 /** 260 * of_device_modalias - Fill buffer with newline terminated modalias string 261 */ 262 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len) 263 { 264 ssize_t sl = of_device_get_modalias(dev, str, len - 2); 265 if (sl < 0) 266 return sl; 267 if (sl > len - 2) 268 return -ENOMEM; 269 270 str[sl++] = '\n'; 271 str[sl] = 0; 272 return sl; 273 } 274 EXPORT_SYMBOL_GPL(of_device_modalias); 275 276 /** 277 * of_device_uevent - Display OF related uevent information 278 */ 279 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env) 280 { 281 const char *compat, *type; 282 struct alias_prop *app; 283 struct property *p; 284 int seen = 0; 285 286 if ((!dev) || (!dev->of_node)) 287 return; 288 289 add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node); 290 add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node); 291 type = of_node_get_device_type(dev->of_node); 292 if (type) 293 add_uevent_var(env, "OF_TYPE=%s", type); 294 295 /* Since the compatible field can contain pretty much anything 296 * it's not really legal to split it out with commas. We split it 297 * up using a number of environment variables instead. */ 298 of_property_for_each_string(dev->of_node, "compatible", p, compat) { 299 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat); 300 seen++; 301 } 302 add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen); 303 304 seen = 0; 305 mutex_lock(&of_mutex); 306 list_for_each_entry(app, &aliases_lookup, link) { 307 if (dev->of_node == app->np) { 308 add_uevent_var(env, "OF_ALIAS_%d=%s", seen, 309 app->alias); 310 seen++; 311 } 312 } 313 mutex_unlock(&of_mutex); 314 } 315 316 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env) 317 { 318 int sl; 319 320 if ((!dev) || (!dev->of_node)) 321 return -ENODEV; 322 323 /* Devicetree modalias is tricky, we add it in 2 steps */ 324 if (add_uevent_var(env, "MODALIAS=")) 325 return -ENOMEM; 326 327 sl = of_device_get_modalias(dev, &env->buf[env->buflen-1], 328 sizeof(env->buf) - env->buflen); 329 if (sl >= (sizeof(env->buf) - env->buflen)) 330 return -ENOMEM; 331 env->buflen += sl; 332 333 return 0; 334 } 335 EXPORT_SYMBOL_GPL(of_device_uevent_modalias); 336