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 struct platform_device *of_dev_get(struct platform_device *dev)
42 tmp = get_device(&dev->dev);
44 return to_platform_device(tmp);
48 EXPORT_SYMBOL(of_dev_get);
50 void of_dev_put(struct platform_device *dev)
53 put_device(&dev->dev);
55 EXPORT_SYMBOL(of_dev_put);
57 int of_device_add(struct platform_device *ofdev)
59 BUG_ON(ofdev->dev.of_node == NULL);
61 /* name and id have to be set so that the platform bus doesn't get
62 * confused on matching */
63 ofdev->name = dev_name(&ofdev->dev);
64 ofdev->id = PLATFORM_DEVID_NONE;
67 * If this device has not binding numa node in devicetree, that is
68 * of_node_to_nid returns NUMA_NO_NODE. device_add will assume that this
69 * device is on the same node as the parent.
71 set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
73 return device_add(&ofdev->dev);
77 * of_dma_configure - Setup DMA configuration
78 * @dev: Device to apply DMA configuration
79 * @np: Pointer to OF node having DMA configuration
80 * @force_dma: Whether device is to be set up by of_dma_configure() even if
81 * DMA capability is not explicitly described by firmware.
82 * @id: Optional const pointer value input id
84 * Try to get devices's DMA configuration from DT and update it
87 * If platform code needs to use its own special DMA configuration, it
88 * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
89 * to fix up DMA configuration.
91 int of_dma_configure_id(struct device *dev, struct device_node *np,
92 bool force_dma, const u32 *id)
94 const struct iommu_ops *iommu;
95 const struct bus_dma_region *map = NULL;
97 u64 mask, end, size = 0;
101 ret = of_dma_get_range(np, &map);
104 * For legacy reasons, we have to assume some devices need
105 * DMA configuration regardless of whether "dma-ranges" is
106 * correctly specified or not.
109 return ret == -ENODEV ? 0 : ret;
111 const struct bus_dma_region *r = map;
114 /* Determine the overall bounds of all DMA regions */
115 for (dma_start = ~0; r->size; r++) {
116 /* Take lower and upper limits */
117 if (r->dma_start < dma_start)
118 dma_start = r->dma_start;
119 if (r->dma_start + r->size > dma_end)
120 dma_end = r->dma_start + r->size;
122 size = dma_end - dma_start;
125 * Add a work around to treat the size as mask + 1 in case
126 * it is defined in DT as a mask.
129 dev_warn(dev, "Invalid size 0x%llx for dma-range(s)\n",
135 dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
142 * If @dev is expected to be DMA-capable then the bus code that created
143 * it should have initialised its dma_mask pointer by this point. For
144 * now, we'll continue the legacy behaviour of coercing it to the
145 * coherent mask if not, but we'll no longer do so quietly.
147 if (!dev->dma_mask) {
148 dev_warn(dev, "DMA mask not set\n");
149 dev->dma_mask = &dev->coherent_dma_mask;
152 if (!size && dev->coherent_dma_mask)
153 size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
158 * Limit coherent and dma mask based on size and default mask
161 end = dma_start + size - 1;
162 mask = DMA_BIT_MASK(ilog2(end) + 1);
163 dev->coherent_dma_mask &= mask;
164 *dev->dma_mask &= mask;
165 /* ...but only set bus limit and range map if we found valid dma-ranges earlier */
167 dev->bus_dma_limit = end;
168 dev->dma_range_map = map;
171 coherent = of_dma_is_coherent(np);
172 dev_dbg(dev, "device is%sdma coherent\n",
173 coherent ? " " : " not ");
175 iommu = of_iommu_configure(dev, np, id);
176 if (PTR_ERR(iommu) == -EPROBE_DEFER) {
177 /* Don't touch range map if it wasn't set from a valid dma-ranges */
179 dev->dma_range_map = NULL;
181 return -EPROBE_DEFER;
184 dev_dbg(dev, "device is%sbehind an iommu\n",
185 iommu ? " " : " not ");
187 arch_setup_dma_ops(dev, dma_start, size, iommu, coherent);
191 EXPORT_SYMBOL_GPL(of_dma_configure_id);
193 int of_device_register(struct platform_device *pdev)
195 device_initialize(&pdev->dev);
196 return of_device_add(pdev);
198 EXPORT_SYMBOL(of_device_register);
200 void of_device_unregister(struct platform_device *ofdev)
202 device_unregister(&ofdev->dev);
204 EXPORT_SYMBOL(of_device_unregister);
206 const void *of_device_get_match_data(const struct device *dev)
208 const struct of_device_id *match;
210 match = of_match_device(dev->driver->of_match_table, dev);
216 EXPORT_SYMBOL(of_device_get_match_data);
218 static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
226 if ((!dev) || (!dev->of_node))
230 /* %p eats all alphanum characters, so %c must be used here */
231 csize = snprintf(str, len, "of:N%pOFn%c%s", dev->of_node, 'T',
232 of_node_get_device_type(dev->of_node));
238 of_property_for_each_string(dev->of_node, "compatible", p, compat) {
239 csize = strlen(compat) + 1;
244 csize = snprintf(str, len, "C%s", compat);
257 int of_device_request_module(struct device *dev)
263 size = of_device_get_modalias(dev, NULL, 0);
267 str = kmalloc(size + 1, GFP_KERNEL);
271 of_device_get_modalias(dev, str, size);
273 ret = request_module(str);
278 EXPORT_SYMBOL_GPL(of_device_request_module);
281 * of_device_modalias - Fill buffer with newline terminated modalias string
283 ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len)
285 ssize_t sl = of_device_get_modalias(dev, str, len - 2);
295 EXPORT_SYMBOL_GPL(of_device_modalias);
298 * of_device_uevent - Display OF related uevent information
300 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
302 const char *compat, *type;
303 struct alias_prop *app;
307 if ((!dev) || (!dev->of_node))
310 add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node);
311 add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node);
312 type = of_node_get_device_type(dev->of_node);
314 add_uevent_var(env, "OF_TYPE=%s", type);
316 /* Since the compatible field can contain pretty much anything
317 * it's not really legal to split it out with commas. We split it
318 * up using a number of environment variables instead. */
319 of_property_for_each_string(dev->of_node, "compatible", p, compat) {
320 add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
323 add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
326 mutex_lock(&of_mutex);
327 list_for_each_entry(app, &aliases_lookup, link) {
328 if (dev->of_node == app->np) {
329 add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
334 mutex_unlock(&of_mutex);
337 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
341 if ((!dev) || (!dev->of_node))
344 /* Devicetree modalias is tricky, we add it in 2 steps */
345 if (add_uevent_var(env, "MODALIAS="))
348 sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
349 sizeof(env->buf) - env->buflen);
350 if (sl >= (sizeof(env->buf) - env->buflen))
356 EXPORT_SYMBOL_GPL(of_device_uevent_modalias);