1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/string.h>
3 #include <linux/kernel.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>
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))
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_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
63 * Try to get devices's DMA configuration from DT and update it
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.
70 int of_dma_configure_id(struct device *dev, struct device_node *np,
71 bool force_dma, const u32 *id)
73 const struct iommu_ops *iommu;
74 const struct bus_dma_region *map = NULL;
76 u64 mask, end, size = 0;
80 ret = of_dma_get_range(np, &map);
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.
88 return ret == -ENODEV ? 0 : ret;
90 const struct bus_dma_region *r = map;
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;
101 size = dma_end - dma_start;
104 * Add a work around to treat the size as mask + 1 in case
105 * it is defined in DT as a mask.
108 dev_warn(dev, "Invalid size 0x%llx for dma-range(s)\n",
114 dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
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.
126 if (!dev->dma_mask) {
127 dev_warn(dev, "DMA mask not set\n");
128 dev->dma_mask = &dev->coherent_dma_mask;
131 if (!size && dev->coherent_dma_mask)
132 size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
137 * Limit coherent and dma mask based on size and default mask
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 */
146 dev->bus_dma_limit = end;
147 dev->dma_range_map = map;
150 coherent = of_dma_is_coherent(np);
151 dev_dbg(dev, "device is%sdma coherent\n",
152 coherent ? " " : " not ");
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 */
158 dev->dma_range_map = NULL;
160 return -EPROBE_DEFER;
163 dev_dbg(dev, "device is%sbehind an iommu\n",
164 iommu ? " " : " not ");
166 arch_setup_dma_ops(dev, dma_start, size, iommu, coherent);
170 EXPORT_SYMBOL_GPL(of_dma_configure_id);
172 int of_device_register(struct platform_device *pdev)
174 device_initialize(&pdev->dev);
175 return of_device_add(pdev);
177 EXPORT_SYMBOL(of_device_register);
179 void of_device_unregister(struct platform_device *ofdev)
181 device_unregister(&ofdev->dev);
183 EXPORT_SYMBOL(of_device_unregister);
185 const void *of_device_get_match_data(const struct device *dev)
187 const struct of_device_id *match;
189 match = of_match_device(dev->driver->of_match_table, dev);
195 EXPORT_SYMBOL(of_device_get_match_data);
197 static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
205 if ((!dev) || (!dev->of_node))
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));
217 of_property_for_each_string(dev->of_node, "compatible", p, compat) {
218 csize = strlen(compat) + 1;
223 csize = snprintf(str, len, "C%s", compat);
236 int of_device_request_module(struct device *dev)
242 size = of_device_get_modalias(dev, NULL, 0);
246 str = kmalloc(size + 1, GFP_KERNEL);
250 of_device_get_modalias(dev, str, size);
252 ret = request_module(str);
257 EXPORT_SYMBOL_GPL(of_device_request_module);
260 * of_device_modalias - Fill buffer with newline terminated modalias string
262 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len)
264 ssize_t sl = of_device_get_modalias(dev, str, len - 2);
274 EXPORT_SYMBOL_GPL(of_device_modalias);
277 * of_device_uevent - Display OF related uevent information
279 void of_device_uevent(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);
316 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
320 if ((!dev) || (!dev->of_node))
323 /* Devicetree modalias is tricky, we add it in 2 steps */
324 if (add_uevent_var(env, "MODALIAS="))
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))
335 EXPORT_SYMBOL_GPL(of_device_uevent_modalias);