1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kernel.h>
4 #include <linux/of_device.h>
5 #include <linux/of_address.h>
6 #include <linux/of_iommu.h>
7 #include <linux/of_reserved_mem.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/mod_devicetable.h>
12 #include <linux/slab.h>
13 #include <linux/platform_device.h>
15 #include <asm/errno.h>
16 #include "of_private.h"
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
23 * Used by a driver to check whether an platform_device present in the
24 * system is in its list of supported devices.
26 const struct of_device_id *of_match_device(const struct of_device_id *matches,
27 const struct device *dev)
29 if (!matches || !dev->of_node || dev->of_node_reused)
31 return of_match_node(matches, dev->of_node);
33 EXPORT_SYMBOL(of_match_device);
35 int of_device_add(struct platform_device *ofdev)
37 BUG_ON(ofdev->dev.of_node == NULL);
39 /* name and id have to be set so that the platform bus doesn't get
40 * confused on matching */
41 ofdev->name = dev_name(&ofdev->dev);
42 ofdev->id = PLATFORM_DEVID_NONE;
45 * If this device has not binding numa node in devicetree, that is
46 * of_node_to_nid returns NUMA_NO_NODE. device_add will assume that this
47 * device is on the same node as the parent.
49 set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
51 return device_add(&ofdev->dev);
55 of_dma_set_restricted_buffer(struct device *dev, struct device_node *np)
57 struct device_node *node, *of_node = dev->of_node;
60 if (!IS_ENABLED(CONFIG_DMA_RESTRICTED_POOL))
63 count = of_property_count_elems_of_size(of_node, "memory-region",
66 * If dev->of_node doesn't exist or doesn't contain memory-region, try
67 * the OF node having DMA configuration.
71 count = of_property_count_elems_of_size(
72 of_node, "memory-region", sizeof(u32));
75 for (i = 0; i < count; i++) {
76 node = of_parse_phandle(of_node, "memory-region", i);
78 * There might be multiple memory regions, but only one
79 * restricted-dma-pool region is allowed.
81 if (of_device_is_compatible(node, "restricted-dma-pool") &&
82 of_device_is_available(node)) {
90 * Attempt to initialize a restricted-dma-pool region if one was found.
91 * Note that count can hold a negative error code.
93 if (i < count && of_reserved_mem_device_init_by_idx(dev, of_node, i))
94 dev_warn(dev, "failed to initialise \"restricted-dma-pool\" memory node\n");
98 * of_dma_configure_id - Setup DMA configuration
99 * @dev: Device to apply DMA configuration
100 * @np: Pointer to OF node having DMA configuration
101 * @force_dma: Whether device is to be set up by of_dma_configure() even if
102 * DMA capability is not explicitly described by firmware.
103 * @id: Optional const pointer value input id
105 * Try to get devices's DMA configuration from DT and update it
108 * If platform code needs to use its own special DMA configuration, it
109 * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
110 * to fix up DMA configuration.
112 int of_dma_configure_id(struct device *dev, struct device_node *np,
113 bool force_dma, const u32 *id)
115 const struct iommu_ops *iommu;
116 const struct bus_dma_region *map = NULL;
117 struct device_node *bus_np;
119 u64 mask, end, size = 0;
123 if (np == dev->of_node)
124 bus_np = __of_get_dma_parent(np);
126 bus_np = of_node_get(np);
128 ret = of_dma_get_range(bus_np, &map);
132 * For legacy reasons, we have to assume some devices need
133 * DMA configuration regardless of whether "dma-ranges" is
134 * correctly specified or not.
137 return ret == -ENODEV ? 0 : ret;
139 const struct bus_dma_region *r = map;
142 /* Determine the overall bounds of all DMA regions */
143 for (dma_start = ~0; r->size; r++) {
144 /* Take lower and upper limits */
145 if (r->dma_start < dma_start)
146 dma_start = r->dma_start;
147 if (r->dma_start + r->size > dma_end)
148 dma_end = r->dma_start + r->size;
150 size = dma_end - dma_start;
153 * Add a work around to treat the size as mask + 1 in case
154 * it is defined in DT as a mask.
157 dev_warn(dev, "Invalid size 0x%llx for dma-range(s)\n",
163 dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
170 * If @dev is expected to be DMA-capable then the bus code that created
171 * it should have initialised its dma_mask pointer by this point. For
172 * now, we'll continue the legacy behaviour of coercing it to the
173 * coherent mask if not, but we'll no longer do so quietly.
175 if (!dev->dma_mask) {
176 dev_warn(dev, "DMA mask not set\n");
177 dev->dma_mask = &dev->coherent_dma_mask;
180 if (!size && dev->coherent_dma_mask)
181 size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
186 * Limit coherent and dma mask based on size and default mask
189 end = dma_start + size - 1;
190 mask = DMA_BIT_MASK(ilog2(end) + 1);
191 dev->coherent_dma_mask &= mask;
192 *dev->dma_mask &= mask;
193 /* ...but only set bus limit and range map if we found valid dma-ranges earlier */
195 dev->bus_dma_limit = end;
196 dev->dma_range_map = map;
199 coherent = of_dma_is_coherent(np);
200 dev_dbg(dev, "device is%sdma coherent\n",
201 coherent ? " " : " not ");
203 iommu = of_iommu_configure(dev, np, id);
204 if (PTR_ERR(iommu) == -EPROBE_DEFER) {
205 /* Don't touch range map if it wasn't set from a valid dma-ranges */
207 dev->dma_range_map = NULL;
209 return -EPROBE_DEFER;
212 dev_dbg(dev, "device is%sbehind an iommu\n",
213 iommu ? " " : " not ");
215 arch_setup_dma_ops(dev, dma_start, size, iommu, coherent);
218 of_dma_set_restricted_buffer(dev, np);
222 EXPORT_SYMBOL_GPL(of_dma_configure_id);
224 int of_device_register(struct platform_device *pdev)
226 device_initialize(&pdev->dev);
227 return of_device_add(pdev);
229 EXPORT_SYMBOL(of_device_register);
231 void of_device_unregister(struct platform_device *ofdev)
233 device_unregister(&ofdev->dev);
235 EXPORT_SYMBOL(of_device_unregister);
237 const void *of_device_get_match_data(const struct device *dev)
239 const struct of_device_id *match;
241 match = of_match_device(dev->driver->of_match_table, dev);
247 EXPORT_SYMBOL(of_device_get_match_data);
250 * of_device_modalias - Fill buffer with newline terminated modalias string
251 * @dev: Calling device
252 * @str: Modalias string
255 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len)
259 if (!dev || !dev->of_node || dev->of_node_reused)
262 sl = of_modalias(dev->of_node, str, len - 2);
272 EXPORT_SYMBOL_GPL(of_device_modalias);
275 * of_device_uevent - Display OF related uevent information
276 * @dev: Device to display the uevent information for
277 * @env: Kernel object's userspace event reference to fill up
279 void of_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
281 const char *compat, *type;
282 struct alias_prop *app;
286 if ((!dev) || (!dev->of_node))
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);
293 add_uevent_var(env, "OF_TYPE=%s", type);
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);
302 add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
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,
313 mutex_unlock(&of_mutex);
315 EXPORT_SYMBOL_GPL(of_device_uevent);
317 int of_device_uevent_modalias(const struct device *dev, struct kobj_uevent_env *env)
321 if ((!dev) || (!dev->of_node) || dev->of_node_reused)
324 /* Devicetree modalias is tricky, we add it in 2 steps */
325 if (add_uevent_var(env, "MODALIAS="))
328 sl = of_modalias(dev->of_node, &env->buf[env->buflen-1],
329 sizeof(env->buf) - env->buflen);
332 if (sl >= (sizeof(env->buf) - env->buflen))
338 EXPORT_SYMBOL_GPL(of_device_uevent_modalias);