summaryrefslogtreecommitdiffstats
path: root/common/oftree.c
blob: 5bb5420a785b531b9cd54ce14188616be8a42925 (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
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
#include <common.h>
#include <environment.h>
#include <fdt.h>
#include <of.h>
#include <command.h>
#include <fs.h>
#include <malloc.h>
#include <linux/ctype.h>
#include <asm/byteorder.h>
#include <errno.h>
#include <getopt.h>
#include <init.h>
#include <boot.h>
#include <bootsource.h>
#include <i2c/i2c.h>
#include <reset_source.h>

#define MAX_LEVEL	32		/* how deeply nested we will go */

static int is_printable_string(const void *data, int len)
{
	const char *s = data;

	/* zero length is not */
	if (len == 0)
		return 0;

	/* must terminate with zero */
	if (s[len - 1] != '\0')
		return 0;

	/* printable or a null byte (concatenated strings) */
	while (((*s == '\0') || isprint(*s)) && (len > 0)) {
		/*
		 * If we see a null, there are three possibilities:
		 * 1) If len == 1, it is the end of the string, printable
		 * 2) Next character also a null, not printable.
		 * 3) Next character not a null, continue to check.
		 */
		if (s[0] == '\0') {
			if (len == 1)
				return 1;
			if (s[1] == '\0')
				return 0;
		}
		s++;
		len--;
	}

	/* Not the null termination, or not done yet: not printable */
	if (*s != '\0' || (len != 0))
		return 0;

	return 1;
}

/*
 * Print the property in the best format, a heuristic guess.  Print as
 * a string, concatenated strings, a byte, word, double word, or (if all
 * else fails) it is printed as a stream of bytes.
 */
void of_print_property(const void *data, int len)
{
	int j;

	/* no data, don't print */
	if (len == 0)
		return;

	/*
	 * It is a string, but it may have multiple strings (embedded '\0's).
	 */
	if (is_printable_string(data, len)) {
		puts("\"");
		j = 0;
		while (j < len) {
			if (j > 0)
				puts("\", \"");
			puts(data);
			j    += strlen(data) + 1;
			data += strlen(data) + 1;
		}
		puts("\"");
		return;
	}

	if ((len % 4) == 0) {
		const u32 *p;

		printf("<");
		for (j = 0, p = data; j < len/4; j ++)
			printf("0x%x%s", fdt32_to_cpu(p[j]), j < (len/4 - 1) ? " " : "");
		printf(">");
	} else { /* anything else... hexdump */
		const u8 *s;

		printf("[");
		for (j = 0, s = data; j < len; j++)
			printf("%02x%s", s[j], j < len - 1 ? " " : "");
		printf("]");
	}
}

void of_print_cmdline(struct device_node *root)
{
	struct device_node *node = of_find_node_by_path_from(root, "/chosen");
	const char *cmdline;

	if (!node) {
		printf("commandline: no /chosen node\n");
		return;
	}

	cmdline = of_get_property(node, "bootargs", NULL);

	printf("commandline: %s\n", cmdline);
}

static int of_fixup_bootargs_bootsource(struct device_node *root,
					struct device_node *chosen)
{
	char *alias_name = bootsource_get_alias_name();
	struct device_node *bootsource;
	int ret = 0;

	if (!alias_name)
		return 0;

	bootsource = of_find_node_by_alias(root, alias_name);
	/*
	 * If kernel DTB doesn't have the appropriate alias set up,
	 * give up and exit early. No error is reported.
	 */
	if (bootsource)
		ret = of_set_property(chosen, "bootsource", bootsource->full_name,
				      strlen(bootsource->full_name) + 1, true);

	free(alias_name);
	return ret;
}

static int of_fixup_bootargs(struct device_node *root, void *unused)
{
	struct device_node *node;
	const char *str;
	int err;

	str = linux_bootargs_get();
	if (!str)
		return 0;

	node = of_create_node(root, "/chosen");
	if (!node)
		return -ENOMEM;

	of_property_write_string(node, "barebox-version", release_string);

	err = of_property_write_string(node, "bootargs", str);
	if (err)
		return err;

	of_property_write_string(node, "reset-source", reset_source_name());
	of_property_write_u32(node, "reset-source-instance",
			      reset_source_get_instance());

	return of_fixup_bootargs_bootsource(root, node);
}

static int of_register_bootargs_fixup(void)
{
	return of_register_fixup(of_fixup_bootargs, NULL);
}
late_initcall(of_register_bootargs_fixup);

struct of_fixup_status_data {
	const char *path;
	bool status;
};

static int of_fixup_status(struct device_node *root, void *context)
{
	const struct of_fixup_status_data *data = context;
	struct device_node *node;

	node = of_find_node_by_path_or_alias(root, data->path);
	if (!node)
		return -ENODEV;

	if (data->status)
		return of_device_enable(node);
	else
		return of_device_disable(node);
}

/**
 * of_register_set_status_fixup - register fix up to set status of nodes
 * Register a fixup to enable or disable a node in the devicet tree by
 * passing the path or alias.
 */
int of_register_set_status_fixup(const char *path, bool status)
{
	struct of_fixup_status_data *data;

	data = xzalloc(sizeof(*data));
	data->path = path;
	data->status = status;

	return of_register_fixup(of_fixup_status, (void *)data);
}

struct of_fixup {
	int (*fixup)(struct device_node *, void *);
	void *context;
	struct list_head list;
};

static LIST_HEAD(of_fixup_list);

int of_register_fixup(int (*fixup)(struct device_node *, void *), void *context)
{
	struct of_fixup *of_fixup = xzalloc(sizeof(*of_fixup));

	of_fixup->fixup = fixup;
	of_fixup->context = context;

	list_add_tail(&of_fixup->list, &of_fixup_list);

	return 0;
}

/*
 * Remove a previously registered fixup. Only the first (if any) is removed.
 * Returns 0 if a match was found (and removed), -ENOENT otherwise.
 */
int of_unregister_fixup(int (*fixup)(struct device_node *, void *),
			void *context)
{
	struct of_fixup *of_fixup;

	list_for_each_entry(of_fixup, &of_fixup_list, list) {
		if (of_fixup->fixup == fixup && of_fixup->context == context) {
			list_del(&of_fixup->list);
			return 0;
		}
	}

	return -ENOENT;
}

/*
 * Apply registered fixups for the given fdt. The fdt must have
 * enough free space to apply the fixups.
 */
int of_fix_tree(struct device_node *node)
{
	struct of_fixup *of_fixup;
	int ret;

	list_for_each_entry(of_fixup, &of_fixup_list, list) {
		ret = of_fixup->fixup(node, of_fixup->context);
		if (ret)
			pr_warn("Failed to fixup node in %pS: %s\n",
					of_fixup->fixup, strerror(-ret));
	}

	return 0;
}

/*
 * Get the fixed fdt. This function uses the fdt input pointer
 * if provided or the barebox internal devicetree if not.
 * It increases the size of the tree and applies the registered
 * fixups.
 */
struct fdt_header *of_get_fixed_tree(struct device_node *node)
{
	int ret;
	struct fdt_header *fdt;

	if (!node) {
		node = of_get_root_node();
		if (!node)
			return NULL;
	}

	ret = of_fix_tree(node);
	if (ret)
		return NULL;

	fdt = of_flatten_dtb(node);
	if (!fdt)
		return NULL;

	return fdt;
}

/**
 * of_autoenable_device_by_path() - Autoenable a device by a device tree path
 * @param path Device tree path up from the root to the device
 * @return 0 on success, -enodev on failure. If no device found in the device
 * tree.
 *
 * This function will search for a device and will enable it in the kernel
 * device tree, if it exists and is loaded.
 */
int of_autoenable_device_by_path(char *path)
{
	struct device_node *node;
	int ret;

	node = of_find_node_by_name(NULL, path);
	if (!node)
		node = of_find_node_by_path(path);

	if (!node)
		return -ENODEV;

	if (!of_device_is_available(node))
			return -ENODEV;

	ret = of_register_set_status_fixup(path, 1);
	if (!ret)
		printf("autoenabled %s\n", node->name);
	return ret;
}

/**
 * of_autoenable_i2c_by_component - Autoenable a i2c client by a device tree path
 * @param path Device tree path up from the root to the i2c client
 * @return 0 on success, -enodev on failure. If no i2c client found in the i2c
 * device tree.
 *
 * This function will search for a i2c client, tries to write to the client and
 * will enable it in the kernel device tree, if it exists and is accessible.
 */
int of_autoenable_i2c_by_component(char *path)
{
	struct device_node *node;
	struct i2c_adapter *i2c_adapter;
	struct i2c_msg msg;
	char data[1] = {0x0};
	int ret;
	uint32_t addr;

	if (!IS_ENABLED(CONFIG_I2C))
		return -ENODEV;

	node = of_find_node_by_name(NULL, path);
	if (!node)
		node = of_find_node_by_path(path);
	if (!node)
		return -ENODEV;
	if (!node->parent)
		return -ENODEV;

	ret = of_property_read_u32(node, "reg", &addr);
	if (ret)
		return -ENODEV;

	i2c_adapter = of_find_i2c_adapter_by_node(node->parent);
	if (!i2c_adapter)
		return -ENODEV;

	msg.buf = data;
	msg.addr = addr;
	msg.len = 1;

	/* Try to communicate with the i2c client */
	ret = i2c_transfer(i2c_adapter, &msg, 1);
	if (ret == -EREMOTEIO)
		return -ENODEV;
	if (ret < 1) {
		printf("failed to autoenable i2c device on address 0x%x with %i\n",
								addr, ret);
		return ret;
	}

	ret = of_register_set_status_fixup(path, 1);
	if (!ret)
		printf("autoenabled i2c device %s\n", node->name);

	return ret;
}