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/module.h>
12 #include <linux/mod_devicetable.h>
13 #include <linux/slab.h>
14 #include <linux/platform_device.h>
16 #include <asm/errno.h>
17 #include "of_private.h"
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
24 * Used by a driver to check whether an platform_device present in the
25 * system is in its list of supported devices.
27 const struct of_device_id *of_match_device(const struct of_device_id *matches,
28 const struct device *dev)
30 if (!matches || !dev->of_node || dev->of_node_reused)
32 return of_match_node(matches, dev->of_node);
34 EXPORT_SYMBOL(of_match_device);
36 int of_device_add(struct platform_device *ofdev)
38 BUG_ON(ofdev->dev.of_node == NULL);
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;
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.
50 set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
52 return device_add(&ofdev->dev);
56 of_dma_set_restricted_buffer(struct device *dev, struct device_node *np)
58 struct device_node *node, *of_node = dev->of_node;
61 if (!IS_ENABLED(CONFIG_DMA_RESTRICTED_POOL))
64 count = of_property_count_elems_of_size(of_node, "memory-region",
67 * If dev->of_node doesn't exist or doesn't contain memory-region, try
68 * the OF node having DMA configuration.
72 count = of_property_count_elems_of_size(
73 of_node, "memory-region", sizeof(u32));
76 for (i = 0; i < count; i++) {
77 node = of_parse_phandle(of_node, "memory-region", i);
79 * There might be multiple memory regions, but only one
80 * restricted-dma-pool region is allowed.
82 if (of_device_is_compatible(node, "restricted-dma-pool") &&
83 of_device_is_available(node)) {
91 * Attempt to initialize a restricted-dma-pool region if one was found.
92 * Note that count can hold a negative error code.
94 if (i < count && of_reserved_mem_device_init_by_idx(dev, of_node, i))
95 dev_warn(dev, "failed to initialise \"restricted-dma-pool\" memory node\n");
99 * of_dma_configure_id - Setup DMA configuration
100 * @dev: Device to apply DMA configuration
101 * @np: Pointer to OF node having DMA configuration
102 * @force_dma: Whether device is to be set up by of_dma_configure() even if
103 * DMA capability is not explicitly described by firmware.
104 * @id: Optional const pointer value input id
106 * Try to get devices's DMA configuration from DT and update it
109 * If platform code needs to use its own special DMA configuration, it
110 * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
111 * to fix up DMA configuration.
113 int of_dma_configure_id(struct device *dev, struct device_node *np,
114 bool force_dma, const u32 *id)
116 const struct iommu_ops *iommu;
117 const struct bus_dma_region *map = NULL;
118 struct device_node *bus_np;
120 u64 mask, end, size = 0;
124 if (np == dev->of_node)
125 bus_np = __of_get_dma_parent(np);
127 bus_np = of_node_get(np);
129 ret = of_dma_get_range(bus_np, &map);
133 * For legacy reasons, we have to assume some devices need
134 * DMA configuration regardless of whether "dma-ranges" is
135 * correctly specified or not.
138 return ret == -ENODEV ? 0 : ret;
140 const struct bus_dma_region *r = map;
143 /* Determine the overall bounds of all DMA regions */
144 for (dma_start = ~0; r->size; r++) {
145 /* Take lower and upper limits */
146 if (r->dma_start < dma_start)
147 dma_start = r->dma_start;
148 if (r->dma_start + r->size > dma_end)
149 dma_end = r->dma_start + r->size;
151 size = dma_end - dma_start;
154 * Add a work around to treat the size as mask + 1 in case
155 * it is defined in DT as a mask.
158 dev_warn(dev, "Invalid size 0x%llx for dma-range(s)\n",
164 dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
171 * If @dev is expected to be DMA-capable then the bus code that created
172 * it should have initialised its dma_mask pointer by this point. For
173 * now, we'll continue the legacy behaviour of coercing it to the
174 * coherent mask if not, but we'll no longer do so quietly.
176 if (!dev->dma_mask) {
177 dev_warn(dev, "DMA mask not set\n");
178 dev->dma_mask = &dev->coherent_dma_mask;
181 if (!size && dev->coherent_dma_mask)
182 size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
187 * Limit coherent and dma mask based on size and default mask
190 end = dma_start + size - 1;
191 mask = DMA_BIT_MASK(ilog2(end) + 1);
192 dev->coherent_dma_mask &= mask;
193 *dev->dma_mask &= mask;
194 /* ...but only set bus limit and range map if we found valid dma-ranges earlier */
196 dev->bus_dma_limit = end;
197 dev->dma_range_map = map;
200 coherent = of_dma_is_coherent(np);
201 dev_dbg(dev, "device is%sdma coherent\n",
202 coherent ? " " : " not ");
204 iommu = of_iommu_configure(dev, np, id);
205 if (PTR_ERR(iommu) == -EPROBE_DEFER) {
206 /* Don't touch range map if it wasn't set from a valid dma-ranges */
208 dev->dma_range_map = NULL;
210 return -EPROBE_DEFER;
213 dev_dbg(dev, "device is%sbehind an iommu\n",
214 iommu ? " " : " not ");
216 arch_setup_dma_ops(dev, dma_start, size, iommu, coherent);
219 of_dma_set_restricted_buffer(dev, np);
223 EXPORT_SYMBOL_GPL(of_dma_configure_id);
225 int of_device_register(struct platform_device *pdev)
227 device_initialize(&pdev->dev);
228 return of_device_add(pdev);
230 EXPORT_SYMBOL(of_device_register);
232 void of_device_unregister(struct platform_device *ofdev)
234 device_unregister(&ofdev->dev);
236 EXPORT_SYMBOL(of_device_unregister);
238 const void *of_device_get_match_data(const struct device *dev)
240 const struct of_device_id *match;
242 match = of_match_device(dev->driver->of_match_table, dev);
248 EXPORT_SYMBOL(of_device_get_match_data);
250 int of_device_request_module(struct device *dev)
256 if (!dev || !dev->of_node)
259 size = of_modalias(dev->of_node, NULL, 0);
263 /* Reserve an additional byte for the trailing '\0' */
266 str = kmalloc(size, GFP_KERNEL);
270 of_modalias(dev->of_node, str, size);
271 str[size - 1] = '\0';
272 ret = request_module(str);
277 EXPORT_SYMBOL_GPL(of_device_request_module);
280 * of_device_modalias - Fill buffer with newline terminated modalias string
281 * @dev: Calling device
282 * @str: Modalias string
285 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len)
289 if (!dev || !dev->of_node || dev->of_node_reused)
292 sl = of_modalias(dev->of_node, str, len - 2);
302 EXPORT_SYMBOL_GPL(of_device_modalias);
305 * of_device_uevent - Display OF related uevent information
306 * @dev: Device to display the uevent information for
307 * @env: Kernel object's userspace event reference to fill up
309 void of_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
311 const char *compat, *type;
312 struct alias_prop *app;
316 if ((!dev) || (!dev->of_node))
319 add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node);
320 add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node);
321 type = of_node_get_device_type(dev->of_node);
323 add_uevent_var(env, "OF_TYPE=%s", type);
325 /* Since the compatible field can contain pretty much anything
326 * it's not really legal to split it out with commas. We split it
327 * up using a number of environment variables instead. */
328 of_property_for_each_string(dev->of_node, "compatible", p, compat) {
329 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
332 add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
335 mutex_lock(&of_mutex);
336 list_for_each_entry(app, &aliases_lookup, link) {
337 if (dev->of_node == app->np) {
338 add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
343 mutex_unlock(&of_mutex);
346 int of_device_uevent_modalias(const struct device *dev, struct kobj_uevent_env *env)
350 if ((!dev) || (!dev->of_node) || dev->of_node_reused)
353 /* Devicetree modalias is tricky, we add it in 2 steps */
354 if (add_uevent_var(env, "MODALIAS="))
357 sl = of_modalias(dev->of_node, &env->buf[env->buflen-1],
358 sizeof(env->buf) - env->buflen);
361 if (sl >= (sizeof(env->buf) - env->buflen))
367 EXPORT_SYMBOL_GPL(of_device_uevent_modalias);