1 #include <linux/string.h> 2 #include <linux/kernel.h> 3 #include <linux/of.h> 4 #include <linux/of_device.h> 5 #include <linux/of_address.h> 6 #include <linux/of_iommu.h> 7 #include <linux/dma-mapping.h> 8 #include <linux/init.h> 9 #include <linux/module.h> 10 #include <linux/mod_devicetable.h> 11 #include <linux/slab.h> 12 13 #include <asm/errno.h> 14 #include "of_private.h" 15 16 /** 17 * of_match_device - Tell if a struct device matches an of_device_id list 18 * @ids: array of of device match structures to search in 19 * @dev: the of device structure to match against 20 * 21 * Used by a driver to check whether an platform_device present in the 22 * system is in its list of supported devices. 23 */ 24 const struct of_device_id *of_match_device(const struct of_device_id *matches, 25 const struct device *dev) 26 { 27 if ((!matches) || (!dev->of_node)) 28 return NULL; 29 return of_match_node(matches, dev->of_node); 30 } 31 EXPORT_SYMBOL(of_match_device); 32 33 struct platform_device *of_dev_get(struct platform_device *dev) 34 { 35 struct device *tmp; 36 37 if (!dev) 38 return NULL; 39 tmp = get_device(&dev->dev); 40 if (tmp) 41 return to_platform_device(tmp); 42 else 43 return NULL; 44 } 45 EXPORT_SYMBOL(of_dev_get); 46 47 void of_dev_put(struct platform_device *dev) 48 { 49 if (dev) 50 put_device(&dev->dev); 51 } 52 EXPORT_SYMBOL(of_dev_put); 53 54 int of_device_add(struct platform_device *ofdev) 55 { 56 BUG_ON(ofdev->dev.of_node == NULL); 57 58 /* name and id have to be set so that the platform bus doesn't get 59 * confused on matching */ 60 ofdev->name = dev_name(&ofdev->dev); 61 ofdev->id = -1; 62 63 /* device_add will assume that this device is on the same node as 64 * the parent. If there is no parent defined, set the node 65 * explicitly */ 66 if (!ofdev->dev.parent) 67 set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node)); 68 69 return device_add(&ofdev->dev); 70 } 71 72 /** 73 * of_dma_configure - Setup DMA configuration 74 * @dev: Device to apply DMA configuration 75 * @np: Pointer to OF node having DMA configuration 76 * 77 * Try to get devices's DMA configuration from DT and update it 78 * accordingly. 79 * 80 * If platform code needs to use its own special DMA configuration, it 81 * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events 82 * to fix up DMA configuration. 83 */ 84 void of_dma_configure(struct device *dev, struct device_node *np) 85 { 86 u64 dma_addr, paddr, size; 87 int ret; 88 bool coherent; 89 unsigned long offset; 90 struct iommu_ops *iommu; 91 92 /* 93 * Set default coherent_dma_mask to 32 bit. Drivers are expected to 94 * setup the correct supported mask. 95 */ 96 if (!dev->coherent_dma_mask) 97 dev->coherent_dma_mask = DMA_BIT_MASK(32); 98 99 /* 100 * Set it to coherent_dma_mask by default if the architecture 101 * code has not set it. 102 */ 103 if (!dev->dma_mask) 104 dev->dma_mask = &dev->coherent_dma_mask; 105 106 ret = of_dma_get_range(np, &dma_addr, &paddr, &size); 107 if (ret < 0) { 108 dma_addr = offset = 0; 109 size = dev->coherent_dma_mask + 1; 110 } else { 111 offset = PFN_DOWN(paddr - dma_addr); 112 113 /* 114 * Add a work around to treat the size as mask + 1 in case 115 * it is defined in DT as a mask. 116 */ 117 if (size & 1) { 118 dev_warn(dev, "Invalid size 0x%llx for dma-range\n", 119 size); 120 size = size + 1; 121 } 122 123 if (!size) { 124 dev_err(dev, "Adjusted size 0x%llx invalid\n", size); 125 return; 126 } 127 dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset); 128 } 129 130 dev->dma_pfn_offset = offset; 131 132 /* 133 * Limit coherent and dma mask based on size and default mask 134 * set by the driver. 135 */ 136 dev->coherent_dma_mask = min(dev->coherent_dma_mask, 137 DMA_BIT_MASK(ilog2(dma_addr + size))); 138 *dev->dma_mask = min((*dev->dma_mask), 139 DMA_BIT_MASK(ilog2(dma_addr + size))); 140 141 coherent = of_dma_is_coherent(np); 142 dev_dbg(dev, "device is%sdma coherent\n", 143 coherent ? " " : " not "); 144 145 iommu = of_iommu_configure(dev, np); 146 dev_dbg(dev, "device is%sbehind an iommu\n", 147 iommu ? " " : " not "); 148 149 arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent); 150 } 151 EXPORT_SYMBOL_GPL(of_dma_configure); 152 153 int of_device_register(struct platform_device *pdev) 154 { 155 device_initialize(&pdev->dev); 156 return of_device_add(pdev); 157 } 158 EXPORT_SYMBOL(of_device_register); 159 160 void of_device_unregister(struct platform_device *ofdev) 161 { 162 device_unregister(&ofdev->dev); 163 } 164 EXPORT_SYMBOL(of_device_unregister); 165 166 const void *of_device_get_match_data(const struct device *dev) 167 { 168 const struct of_device_id *match; 169 170 match = of_match_device(dev->driver->of_match_table, dev); 171 if (!match) 172 return NULL; 173 174 return match->data; 175 } 176 EXPORT_SYMBOL(of_device_get_match_data); 177 178 ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len) 179 { 180 const char *compat; 181 int cplen, i; 182 ssize_t tsize, csize, repend; 183 184 if ((!dev) || (!dev->of_node)) 185 return -ENODEV; 186 187 /* Name & Type */ 188 csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name, 189 dev->of_node->type); 190 191 /* Get compatible property if any */ 192 compat = of_get_property(dev->of_node, "compatible", &cplen); 193 if (!compat) 194 return csize; 195 196 /* Find true end (we tolerate multiple \0 at the end */ 197 for (i = (cplen - 1); i >= 0 && !compat[i]; i--) 198 cplen--; 199 if (!cplen) 200 return csize; 201 cplen++; 202 203 /* Check space (need cplen+1 chars including final \0) */ 204 tsize = csize + cplen; 205 repend = tsize; 206 207 if (csize >= len) /* @ the limit, all is already filled */ 208 return tsize; 209 210 if (tsize >= len) { /* limit compat list */ 211 cplen = len - csize - 1; 212 repend = len; 213 } 214 215 /* Copy and do char replacement */ 216 memcpy(&str[csize + 1], compat, cplen); 217 for (i = csize; i < repend; i++) { 218 char c = str[i]; 219 if (c == '\0') 220 str[i] = 'C'; 221 else if (c == ' ') 222 str[i] = '_'; 223 } 224 225 return tsize; 226 } 227 228 /** 229 * of_device_uevent - Display OF related uevent information 230 */ 231 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env) 232 { 233 const char *compat; 234 struct alias_prop *app; 235 int seen = 0, cplen, sl; 236 237 if ((!dev) || (!dev->of_node)) 238 return; 239 240 add_uevent_var(env, "OF_NAME=%s", dev->of_node->name); 241 add_uevent_var(env, "OF_FULLNAME=%s", dev->of_node->full_name); 242 if (dev->of_node->type && strcmp("<NULL>", dev->of_node->type) != 0) 243 add_uevent_var(env, "OF_TYPE=%s", dev->of_node->type); 244 245 /* Since the compatible field can contain pretty much anything 246 * it's not really legal to split it out with commas. We split it 247 * up using a number of environment variables instead. */ 248 compat = of_get_property(dev->of_node, "compatible", &cplen); 249 while (compat && *compat && cplen > 0) { 250 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat); 251 sl = strlen(compat) + 1; 252 compat += sl; 253 cplen -= sl; 254 seen++; 255 } 256 add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen); 257 258 seen = 0; 259 mutex_lock(&of_mutex); 260 list_for_each_entry(app, &aliases_lookup, link) { 261 if (dev->of_node == app->np) { 262 add_uevent_var(env, "OF_ALIAS_%d=%s", seen, 263 app->alias); 264 seen++; 265 } 266 } 267 mutex_unlock(&of_mutex); 268 } 269 270 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env) 271 { 272 int sl; 273 274 if ((!dev) || (!dev->of_node)) 275 return -ENODEV; 276 277 /* Devicetree modalias is tricky, we add it in 2 steps */ 278 if (add_uevent_var(env, "MODALIAS=")) 279 return -ENOMEM; 280 281 sl = of_device_get_modalias(dev, &env->buf[env->buflen-1], 282 sizeof(env->buf) - env->buflen); 283 if (sl >= (sizeof(env->buf) - env->buflen)) 284 return -ENOMEM; 285 env->buflen += sl; 286 287 return 0; 288 } 289