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1 #include <linux/string.h>
2 #include <linux/kernel.h>
3 #include <linux/of.h>
4 #include <linux/of_device.h>
5 #include <linux/of_address.h>
6 #include <linux/of_iommu.h>
7 #include <linux/dma-mapping.h>
8 #include <linux/init.h>
9 #include <linux/module.h>
10 #include <linux/mod_devicetable.h>
11 #include <linux/slab.h>
12 
13 #include <asm/errno.h>
14 #include "of_private.h"
15 
16 /**
17  * of_match_device - Tell if a struct device matches an of_device_id list
18  * @ids: array of of device match structures to search in
19  * @dev: the of device structure to match against
20  *
21  * Used by a driver to check whether an platform_device present in the
22  * system is in its list of supported devices.
23  */
of_match_device(const struct of_device_id * matches,const struct device * dev)24 const struct of_device_id *of_match_device(const struct of_device_id *matches,
25 					   const struct device *dev)
26 {
27 	if ((!matches) || (!dev->of_node))
28 		return NULL;
29 	return of_match_node(matches, dev->of_node);
30 }
31 EXPORT_SYMBOL(of_match_device);
32 
of_dev_get(struct platform_device * dev)33 struct platform_device *of_dev_get(struct platform_device *dev)
34 {
35 	struct device *tmp;
36 
37 	if (!dev)
38 		return NULL;
39 	tmp = get_device(&dev->dev);
40 	if (tmp)
41 		return to_platform_device(tmp);
42 	else
43 		return NULL;
44 }
45 EXPORT_SYMBOL(of_dev_get);
46 
of_dev_put(struct platform_device * dev)47 void of_dev_put(struct platform_device *dev)
48 {
49 	if (dev)
50 		put_device(&dev->dev);
51 }
52 EXPORT_SYMBOL(of_dev_put);
53 
of_device_add(struct platform_device * ofdev)54 int of_device_add(struct platform_device *ofdev)
55 {
56 	BUG_ON(ofdev->dev.of_node == NULL);
57 
58 	/* name and id have to be set so that the platform bus doesn't get
59 	 * confused on matching */
60 	ofdev->name = dev_name(&ofdev->dev);
61 	ofdev->id = -1;
62 
63 	/*
64 	 * If this device has not binding numa node in devicetree, that is
65 	 * of_node_to_nid returns NUMA_NO_NODE. device_add will assume that this
66 	 * device is on the same node as the parent.
67 	 */
68 	set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
69 
70 	return device_add(&ofdev->dev);
71 }
72 
73 /**
74  * of_dma_configure - Setup DMA configuration
75  * @dev:	Device to apply DMA configuration
76  * @np:		Pointer to OF node having DMA configuration
77  *
78  * Try to get devices's DMA configuration from DT and update it
79  * accordingly.
80  *
81  * If platform code needs to use its own special DMA configuration, it
82  * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
83  * to fix up DMA configuration.
84  */
of_dma_configure(struct device * dev,struct device_node * np)85 void of_dma_configure(struct device *dev, struct device_node *np)
86 {
87 	u64 dma_addr, paddr, size;
88 	int ret;
89 	bool coherent;
90 	unsigned long offset;
91 	const struct iommu_ops *iommu;
92 
93 	/*
94 	 * Set default coherent_dma_mask to 32 bit.  Drivers are expected to
95 	 * setup the correct supported mask.
96 	 */
97 	if (!dev->coherent_dma_mask)
98 		dev->coherent_dma_mask = DMA_BIT_MASK(32);
99 
100 	/*
101 	 * Set it to coherent_dma_mask by default if the architecture
102 	 * code has not set it.
103 	 */
104 	if (!dev->dma_mask)
105 		dev->dma_mask = &dev->coherent_dma_mask;
106 
107 	ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
108 	if (ret < 0) {
109 		dma_addr = offset = 0;
110 		size = dev->coherent_dma_mask + 1;
111 	} else {
112 		offset = PFN_DOWN(paddr - dma_addr);
113 
114 		/*
115 		 * Add a work around to treat the size as mask + 1 in case
116 		 * it is defined in DT as a mask.
117 		 */
118 		if (size & 1) {
119 			dev_warn(dev, "Invalid size 0x%llx for dma-range\n",
120 				 size);
121 			size = size + 1;
122 		}
123 
124 		if (!size) {
125 			dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
126 			return;
127 		}
128 		dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset);
129 	}
130 
131 	dev->dma_pfn_offset = offset;
132 
133 	/*
134 	 * Limit coherent and dma mask based on size and default mask
135 	 * set by the driver.
136 	 */
137 	dev->coherent_dma_mask = min(dev->coherent_dma_mask,
138 				     DMA_BIT_MASK(ilog2(dma_addr + size)));
139 	*dev->dma_mask = min((*dev->dma_mask),
140 			     DMA_BIT_MASK(ilog2(dma_addr + size)));
141 
142 	coherent = of_dma_is_coherent(np);
143 	dev_dbg(dev, "device is%sdma coherent\n",
144 		coherent ? " " : " not ");
145 
146 	iommu = of_iommu_configure(dev, np);
147 	dev_dbg(dev, "device is%sbehind an iommu\n",
148 		iommu ? " " : " not ");
149 
150 	arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent);
151 }
152 EXPORT_SYMBOL_GPL(of_dma_configure);
153 
of_device_register(struct platform_device * pdev)154 int of_device_register(struct platform_device *pdev)
155 {
156 	device_initialize(&pdev->dev);
157 	return of_device_add(pdev);
158 }
159 EXPORT_SYMBOL(of_device_register);
160 
of_device_unregister(struct platform_device * ofdev)161 void of_device_unregister(struct platform_device *ofdev)
162 {
163 	device_unregister(&ofdev->dev);
164 }
165 EXPORT_SYMBOL(of_device_unregister);
166 
of_device_get_match_data(const struct device * dev)167 const void *of_device_get_match_data(const struct device *dev)
168 {
169 	const struct of_device_id *match;
170 
171 	match = of_match_device(dev->driver->of_match_table, dev);
172 	if (!match)
173 		return NULL;
174 
175 	return match->data;
176 }
177 EXPORT_SYMBOL(of_device_get_match_data);
178 
of_device_get_modalias(struct device * dev,char * str,ssize_t len)179 ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
180 {
181 	const char *compat;
182 	int cplen, i;
183 	ssize_t tsize, csize, repend;
184 
185 	if ((!dev) || (!dev->of_node))
186 		return -ENODEV;
187 
188 	/* Name & Type */
189 	csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
190 			 dev->of_node->type);
191 
192 	/* Get compatible property if any */
193 	compat = of_get_property(dev->of_node, "compatible", &cplen);
194 	if (!compat)
195 		return csize;
196 
197 	/* Find true end (we tolerate multiple \0 at the end */
198 	for (i = (cplen - 1); i >= 0 && !compat[i]; i--)
199 		cplen--;
200 	if (!cplen)
201 		return csize;
202 	cplen++;
203 
204 	/* Check space (need cplen+1 chars including final \0) */
205 	tsize = csize + cplen;
206 	repend = tsize;
207 
208 	if (csize >= len)		/* @ the limit, all is already filled */
209 		return tsize;
210 
211 	if (tsize >= len) {		/* limit compat list */
212 		cplen = len - csize - 1;
213 		repend = len;
214 	}
215 
216 	/* Copy and do char replacement */
217 	memcpy(&str[csize + 1], compat, cplen);
218 	for (i = csize; i < repend; i++) {
219 		char c = str[i];
220 		if (c == '\0')
221 			str[i] = 'C';
222 		else if (c == ' ')
223 			str[i] = '_';
224 	}
225 
226 	return repend;
227 }
228 EXPORT_SYMBOL_GPL(of_device_get_modalias);
229 
230 /**
231  * of_device_uevent - Display OF related uevent information
232  */
of_device_uevent(struct device * dev,struct kobj_uevent_env * env)233 void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
234 {
235 	const char *compat;
236 	struct alias_prop *app;
237 	int seen = 0, cplen, sl;
238 
239 	if ((!dev) || (!dev->of_node))
240 		return;
241 
242 	add_uevent_var(env, "OF_NAME=%s", dev->of_node->name);
243 	add_uevent_var(env, "OF_FULLNAME=%s", dev->of_node->full_name);
244 	if (dev->of_node->type && strcmp("<NULL>", dev->of_node->type) != 0)
245 		add_uevent_var(env, "OF_TYPE=%s", dev->of_node->type);
246 
247 	/* Since the compatible field can contain pretty much anything
248 	 * it's not really legal to split it out with commas. We split it
249 	 * up using a number of environment variables instead. */
250 	compat = of_get_property(dev->of_node, "compatible", &cplen);
251 	while (compat && *compat && cplen > 0) {
252 		add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
253 		sl = strlen(compat) + 1;
254 		compat += sl;
255 		cplen -= sl;
256 		seen++;
257 	}
258 	add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
259 
260 	seen = 0;
261 	mutex_lock(&of_mutex);
262 	list_for_each_entry(app, &aliases_lookup, link) {
263 		if (dev->of_node == app->np) {
264 			add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
265 				       app->alias);
266 			seen++;
267 		}
268 	}
269 	mutex_unlock(&of_mutex);
270 }
271 
of_device_uevent_modalias(struct device * dev,struct kobj_uevent_env * env)272 int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
273 {
274 	int sl;
275 
276 	if ((!dev) || (!dev->of_node))
277 		return -ENODEV;
278 
279 	/* Devicetree modalias is tricky, we add it in 2 steps */
280 	if (add_uevent_var(env, "MODALIAS="))
281 		return -ENOMEM;
282 
283 	sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
284 				    sizeof(env->buf) - env->buflen);
285 	if (sl >= (sizeof(env->buf) - env->buflen))
286 		return -ENOMEM;
287 	env->buflen += sl;
288 
289 	return 0;
290 }
291 EXPORT_SYMBOL_GPL(of_device_uevent_modalias);
292