aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/of/platform.c
blob: 63d3cb73bdb9ac31b46efa252d0075e5c6c16c0a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
/*
 *    Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp.
 *			 <benh@kernel.crashing.org>
 *    and		 Arnd Bergmann, IBM Corp.
 *    Merged from powerpc/kernel/of_platform.c and
 *    sparc{,64}/kernel/of_device.c by Stephen Rothwell
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version
 *  2 of the License, or (at your option) any later version.
 *
 */
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>

static int of_dev_node_match(struct device *dev, void *data)
{
	return dev->of_node == data;
}

/**
 * of_find_device_by_node - Find the platform_device associated with a node
 * @np: Pointer to device tree node
 *
 * Returns platform_device pointer, or NULL if not found
 */
struct platform_device *of_find_device_by_node(struct device_node *np)
{
	struct device *dev;

	dev = bus_find_device(&platform_bus_type, NULL, np, of_dev_node_match);
	return dev ? to_platform_device(dev) : NULL;
}
EXPORT_SYMBOL(of_find_device_by_node);

#if defined(CONFIG_PPC_DCR)
#include <asm/dcr.h>
#endif

#if !defined(CONFIG_SPARC)
/*
 * The following routines scan a subtree and registers a device for
 * each applicable node.
 *
 * Note: sparc doesn't use these routines because it has a different
 * mechanism for creating devices from device tree nodes.
 */

/**
 * of_device_make_bus_id - Use the device node data to assign a unique name
 * @dev: pointer to device structure that is linked to a device tree node
 *
 * This routine will first try using either the dcr-reg or the reg property
 * value to derive a unique name.  As a last resort it will use the node
 * name followed by a unique number.
 */
void of_device_make_bus_id(struct device *dev)
{
	static atomic_t bus_no_reg_magic;
	struct device_node *node = dev->of_node;
	const u32 *reg;
	u64 addr;
	int magic;

#ifdef CONFIG_PPC_DCR
	/*
	 * If it's a DCR based device, use 'd' for native DCRs
	 * and 'D' for MMIO DCRs.
	 */
	reg = of_get_property(node, "dcr-reg", NULL);
	if (reg) {
#ifdef CONFIG_PPC_DCR_NATIVE
		dev_set_name(dev, "d%x.%s", *reg, node->name);
#else /* CONFIG_PPC_DCR_NATIVE */
		u64 addr = of_translate_dcr_address(node, *reg, NULL);
		if (addr != OF_BAD_ADDR) {
			dev_set_name(dev, "D%llx.%s",
				     (unsigned long long)addr, node->name);
			return;
		}
#endif /* !CONFIG_PPC_DCR_NATIVE */
	}
#endif /* CONFIG_PPC_DCR */

	/*
	 * For MMIO, get the physical address
	 */
	reg = of_get_property(node, "reg", NULL);
	if (reg) {
		addr = of_translate_address(node, reg);
		if (addr != OF_BAD_ADDR) {
			dev_set_name(dev, "%llx.%s",
				     (unsigned long long)addr, node->name);
			return;
		}
	}

	/*
	 * No BusID, use the node name and add a globally incremented
	 * counter (and pray...)
	 */
	magic = atomic_add_return(1, &bus_no_reg_magic);
	dev_set_name(dev, "%s.%d", node->name, magic - 1);
}

/**
 * of_device_alloc - Allocate and initialize an of_device
 * @np: device node to assign to device
 * @bus_id: Name to assign to the device.  May be null to use default name.
 * @parent: Parent device.
 */
struct platform_device *of_device_alloc(struct device_node *np,
				  const char *bus_id,
				  struct device *parent)
{
	struct platform_device *dev;
	int rc, i, num_reg = 0, num_irq;
	struct resource *res, temp_res;

	dev = platform_device_alloc("", -1);
	if (!dev)
		return NULL;

	/* count the io and irq resources */
	while (of_address_to_resource(np, num_reg, &temp_res) == 0)
		num_reg++;
	num_irq = of_irq_count(np);

	/* Populate the resource table */
	if (num_irq || num_reg) {
		res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL);
		if (!res) {
			platform_device_put(dev);
			return NULL;
		}

		dev->num_resources = num_reg + num_irq;
		dev->resource = res;
		for (i = 0; i < num_reg; i++, res++) {
			rc = of_address_to_resource(np, i, res);
			WARN_ON(rc);
		}
		WARN_ON(of_irq_to_resource_table(np, res, num_irq) != num_irq);
	}

	dev->dev.of_node = of_node_get(np);
#if defined(CONFIG_PPC) || defined(CONFIG_MICROBLAZE)
	dev->dev.dma_mask = &dev->archdata.dma_mask;
#endif
	dev->dev.parent = parent;

	if (bus_id)
		dev_set_name(&dev->dev, "%s", bus_id);
	else
		of_device_make_bus_id(&dev->dev);

	return dev;
}
EXPORT_SYMBOL(of_device_alloc);

/**
 * of_platform_device_create - Alloc, initialize and register an of_device
 * @np: pointer to node to create device for
 * @bus_id: name to assign device
 * @parent: Linux device model parent device.
 *
 * Returns pointer to created platform device, or NULL if a device was not
 * registered.  Unavailable devices will not get registered.
 */
struct platform_device *of_platform_device_create(struct device_node *np,
					    const char *bus_id,
					    struct device *parent)
{
	struct platform_device *dev;

	if (!of_device_is_available(np))
		return NULL;

	dev = of_device_alloc(np, bus_id, parent);
	if (!dev)
		return NULL;

#if defined(CONFIG_PPC) || defined(CONFIG_MICROBLAZE)
	dev->archdata.dma_mask = 0xffffffffUL;
#endif
	dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
	dev->dev.bus = &platform_bus_type;

	/* We do not fill the DMA ops for platform devices by default.
	 * This is currently the responsibility of the platform code
	 * to do such, possibly using a device notifier
	 */

	if (of_device_add(dev) != 0) {
		platform_device_put(dev);
		return NULL;
	}

	return dev;
}
EXPORT_SYMBOL(of_platform_device_create);

/**
 * of_platform_bus_create() - Create a device for a node and its children.
 * @bus: device node of the bus to instantiate
 * @matches: match table for bus nodes
 * disallow recursive creation of child buses
 * @parent: parent for new device, or NULL for top level.
 *
 * Creates a platform_device for the provided device_node, and optionally
 * recursively create devices for all the child nodes.
 */
static int of_platform_bus_create(struct device_node *bus,
				  const struct of_device_id *matches,
				  struct device *parent)
{
	struct device_node *child;
	struct platform_device *dev;
	int rc = 0;

	dev = of_platform_device_create(bus, NULL, parent);
	if (!dev || !of_match_node(matches, bus))
		return 0;

	for_each_child_of_node(bus, child) {
		pr_debug("   create child: %s\n", child->full_name);
		rc = of_platform_bus_create(child, matches, &dev->dev);
		if (rc) {
			of_node_put(child);
			break;
		}
	}
	return rc;
}

/**
 * of_platform_bus_probe() - Probe the device-tree for platform buses
 * @root: parent of the first level to probe or NULL for the root of the tree
 * @matches: match table for bus nodes
 * @parent: parent to hook devices from, NULL for toplevel
 *
 * Note that children of the provided root are not instantiated as devices
 * unless the specified root itself matches the bus list and is not NULL.
 */
int of_platform_bus_probe(struct device_node *root,
			  const struct of_device_id *matches,
			  struct device *parent)
{
	struct device_node *child;
	int rc = 0;

	root = root ? of_node_get(root) : of_find_node_by_path("/");
	if (!root)
		return -EINVAL;

	pr_debug("of_platform_bus_probe()\n");
	pr_debug(" starting at: %s\n", root->full_name);

	/* Do a self check of bus type, if there's a match, create children */
	if (of_match_node(matches, root)) {
		rc = of_platform_bus_create(root, matches, parent);
	} else for_each_child_of_node(root, child) {
		if (!of_match_node(matches, child))
			continue;
		rc = of_platform_bus_create(child, matches, parent);
		if (rc)
			break;
	}

	of_node_put(root);
	return rc;
}
EXPORT_SYMBOL(of_platform_bus_probe);
#endif /* !CONFIG_SPARC */

Privacy Policy