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 */
of_match_device(const struct of_device_id * matches,const struct device * dev)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
of_dev_get(struct platform_device * dev)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
of_dev_put(struct platform_device * dev)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
of_device_add(struct platform_device * ofdev)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 */
of_dma_configure(struct device * dev,struct device_node * np,bool force_dma)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
of_device_register(struct platform_device * pdev)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
of_device_unregister(struct platform_device * ofdev)182 void of_device_unregister(struct platform_device *ofdev)
183 {
184 device_unregister(&ofdev->dev);
185 }
186 EXPORT_SYMBOL(of_device_unregister);
187
of_device_get_match_data(const struct device * dev)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
of_device_get_modalias(struct device * dev,char * str,ssize_t len)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
of_device_request_module(struct device * dev)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 */
of_device_modalias(struct device * dev,char * str,ssize_t len)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 */
of_device_uevent(struct device * dev,struct kobj_uevent_env * env)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
of_device_uevent_modalias(struct device * dev,struct kobj_uevent_env * env)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