xref: /openbmc/u-boot/arch/sandbox/cpu/state.c (revision 1d2c0506)
1 /*
2  * Copyright (c) 2011-2012 The Chromium OS Authors.
3  * SPDX-License-Identifier:	GPL-2.0+
4  */
5 
6 #include <common.h>
7 #include <errno.h>
8 #include <fdtdec.h>
9 #include <os.h>
10 #include <asm/state.h>
11 
12 /* Main state record for the sandbox */
13 static struct sandbox_state main_state;
14 static struct sandbox_state *state;	/* Pointer to current state record */
15 
16 static int state_ensure_space(int extra_size)
17 {
18 	void *blob = state->state_fdt;
19 	int used, size, free;
20 	void *buf;
21 	int ret;
22 
23 	used = fdt_off_dt_strings(blob) + fdt_size_dt_strings(blob);
24 	size = fdt_totalsize(blob);
25 	free = size - used;
26 	if (free > extra_size)
27 		return 0;
28 
29 	size = used + extra_size;
30 	buf = os_malloc(size);
31 	if (!buf)
32 		return -ENOMEM;
33 
34 	ret = fdt_open_into(blob, buf, size);
35 	if (ret) {
36 		os_free(buf);
37 		return -EIO;
38 	}
39 
40 	os_free(blob);
41 	state->state_fdt = buf;
42 	return 0;
43 }
44 
45 static int state_read_file(struct sandbox_state *state, const char *fname)
46 {
47 	loff_t size;
48 	int ret;
49 	int fd;
50 
51 	ret = os_get_filesize(fname, &size);
52 	if (ret < 0) {
53 		printf("Cannot find sandbox state file '%s'\n", fname);
54 		return -ENOENT;
55 	}
56 	state->state_fdt = os_malloc(size);
57 	if (!state->state_fdt) {
58 		puts("No memory to read sandbox state\n");
59 		return -ENOMEM;
60 	}
61 	fd = os_open(fname, OS_O_RDONLY);
62 	if (fd < 0) {
63 		printf("Cannot open sandbox state file '%s'\n", fname);
64 		ret = -EPERM;
65 		goto err_open;
66 	}
67 	if (os_read(fd, state->state_fdt, size) != size) {
68 		printf("Cannot read sandbox state file '%s'\n", fname);
69 		ret = -EIO;
70 		goto err_read;
71 	}
72 	os_close(fd);
73 
74 	return 0;
75 err_read:
76 	os_close(fd);
77 err_open:
78 	os_free(state->state_fdt);
79 	state->state_fdt = NULL;
80 
81 	return ret;
82 }
83 
84 /***
85  * sandbox_read_state_nodes() - Read state associated with a driver
86  *
87  * This looks through all compatible nodes and calls the read function on
88  * each one, to read in the state.
89  *
90  * If nothing is found, it still calls the read function once, to set up a
91  * single global state for that driver.
92  *
93  * @state: Sandbox state
94  * @io: Method to use for reading state
95  * @blob: FDT containing state
96  * @return 0 if OK, -EINVAL if the read function returned failure
97  */
98 int sandbox_read_state_nodes(struct sandbox_state *state,
99 			     struct sandbox_state_io *io, const void *blob)
100 {
101 	int count;
102 	int node;
103 	int ret;
104 
105 	debug("   - read %s\n", io->name);
106 	if (!io->read)
107 		return 0;
108 
109 	node = -1;
110 	count = 0;
111 	while (blob) {
112 		node = fdt_node_offset_by_compatible(blob, node, io->compat);
113 		if (node < 0)
114 			return 0;	/* No more */
115 		debug("   - read node '%s'\n", fdt_get_name(blob, node, NULL));
116 		ret = io->read(blob, node);
117 		if (ret) {
118 			printf("Unable to read state for '%s'\n", io->compat);
119 			return -EINVAL;
120 		}
121 		count++;
122 	}
123 
124 	/*
125 	 * If we got no saved state, call the read function once without a
126 	 * node, to set up the global state.
127 	 */
128 	if (count == 0) {
129 		debug("   - read global\n");
130 		ret = io->read(NULL, -1);
131 		if (ret) {
132 			printf("Unable to read global state for '%s'\n",
133 			       io->name);
134 			return -EINVAL;
135 		}
136 	}
137 
138 	return 0;
139 }
140 
141 int sandbox_read_state(struct sandbox_state *state, const char *fname)
142 {
143 	struct sandbox_state_io *io;
144 	const void *blob;
145 	bool got_err;
146 	int ret;
147 
148 	if (state->read_state && fname) {
149 		ret = state_read_file(state, fname);
150 		if (ret == -ENOENT && state->ignore_missing_state_on_read)
151 			ret = 0;
152 		if (ret)
153 			return ret;
154 	}
155 
156 	/* Call all the state read funtcions */
157 	got_err = false;
158 	blob = state->state_fdt;
159 	io = ll_entry_start(struct sandbox_state_io, state_io);
160 	for (; io < ll_entry_end(struct sandbox_state_io, state_io); io++) {
161 		ret = sandbox_read_state_nodes(state, io, blob);
162 		if (ret < 0)
163 			got_err = true;
164 	}
165 
166 	if (state->read_state && fname) {
167 		debug("Read sandbox state from '%s'%s\n", fname,
168 		      got_err ? " (with errors)" : "");
169 	}
170 
171 	return got_err ? -1 : 0;
172 }
173 
174 /***
175  * sandbox_write_state_node() - Write state associated with a driver
176  *
177  * This calls the write function to write out global state for that driver.
178  *
179  * TODO(sjg@chromium.org): Support writing out state from multiple drivers
180  * of the same time. We don't need this yet,and it will be much easier to
181  * do when driver model is available.
182  *
183  * @state: Sandbox state
184  * @io: Method to use for writing state
185  * @return 0 if OK, -EIO if there is a fatal error (such as out of space
186  * for adding the data), -EINVAL if the write function failed.
187  */
188 int sandbox_write_state_node(struct sandbox_state *state,
189 			     struct sandbox_state_io *io)
190 {
191 	void *blob;
192 	int node;
193 	int ret;
194 
195 	if (!io->write)
196 		return 0;
197 
198 	ret = state_ensure_space(SANDBOX_STATE_MIN_SPACE);
199 	if (ret) {
200 		printf("Failed to add more space for state\n");
201 		return -EIO;
202 	}
203 
204 	/* The blob location can change when the size increases */
205 	blob = state->state_fdt;
206 	node = fdt_node_offset_by_compatible(blob, -1, io->compat);
207 	if (node == -FDT_ERR_NOTFOUND) {
208 		node = fdt_add_subnode(blob, 0, io->name);
209 		if (node < 0) {
210 			printf("Cannot create node '%s': %s\n", io->name,
211 			       fdt_strerror(node));
212 			return -EIO;
213 		}
214 
215 		if (fdt_setprop_string(blob, node, "compatible", io->compat)) {
216 			puts("Cannot set compatible\n");
217 			return -EIO;
218 		}
219 	} else if (node < 0) {
220 		printf("Cannot access node '%s': %s\n", io->name,
221 		       fdt_strerror(node));
222 		return -EIO;
223 	}
224 	debug("Write state for '%s' to node %d\n", io->compat, node);
225 	ret = io->write(blob, node);
226 	if (ret) {
227 		printf("Unable to write state for '%s'\n", io->compat);
228 		return -EINVAL;
229 	}
230 
231 	return 0;
232 }
233 
234 int sandbox_write_state(struct sandbox_state *state, const char *fname)
235 {
236 	struct sandbox_state_io *io;
237 	bool got_err;
238 	int size;
239 	int ret;
240 	int fd;
241 
242 	/* Create a state FDT if we don't have one */
243 	if (!state->state_fdt) {
244 		size = 0x4000;
245 		state->state_fdt = os_malloc(size);
246 		if (!state->state_fdt) {
247 			puts("No memory to create FDT\n");
248 			return -ENOMEM;
249 		}
250 		ret = fdt_create_empty_tree(state->state_fdt, size);
251 		if (ret < 0) {
252 			printf("Cannot create empty state FDT: %s\n",
253 			       fdt_strerror(ret));
254 			ret = -EIO;
255 			goto err_create;
256 		}
257 	}
258 
259 	/* Call all the state write funtcions */
260 	got_err = false;
261 	io = ll_entry_start(struct sandbox_state_io, state_io);
262 	ret = 0;
263 	for (; io < ll_entry_end(struct sandbox_state_io, state_io); io++) {
264 		ret = sandbox_write_state_node(state, io);
265 		if (ret == -EIO)
266 			break;
267 		else if (ret)
268 			got_err = true;
269 	}
270 
271 	if (ret == -EIO) {
272 		printf("Could not write sandbox state\n");
273 		goto err_create;
274 	}
275 
276 	ret = fdt_pack(state->state_fdt);
277 	if (ret < 0) {
278 		printf("Cannot pack state FDT: %s\n", fdt_strerror(ret));
279 		ret = -EINVAL;
280 		goto err_create;
281 	}
282 	size = fdt_totalsize(state->state_fdt);
283 	fd = os_open(fname, OS_O_WRONLY | OS_O_CREAT);
284 	if (fd < 0) {
285 		printf("Cannot open sandbox state file '%s'\n", fname);
286 		ret = -EIO;
287 		goto err_create;
288 	}
289 	if (os_write(fd, state->state_fdt, size) != size) {
290 		printf("Cannot write sandbox state file '%s'\n", fname);
291 		ret = -EIO;
292 		goto err_write;
293 	}
294 	os_close(fd);
295 
296 	debug("Wrote sandbox state to '%s'%s\n", fname,
297 	      got_err ? " (with errors)" : "");
298 
299 	return 0;
300 err_write:
301 	os_close(fd);
302 err_create:
303 	os_free(state->state_fdt);
304 
305 	return ret;
306 }
307 
308 int state_setprop(int node, const char *prop_name, const void *data, int size)
309 {
310 	void *blob;
311 	int len;
312 	int ret;
313 
314 	fdt_getprop(state->state_fdt, node, prop_name, &len);
315 
316 	/* Add space for the new property, its name and some overhead */
317 	ret = state_ensure_space(size - len + strlen(prop_name) + 32);
318 	if (ret)
319 		return ret;
320 
321 	/* This should succeed, barring a mutiny */
322 	blob = state->state_fdt;
323 	ret = fdt_setprop(blob, node, prop_name, data, size);
324 	if (ret) {
325 		printf("%s: Unable to set property '%s' in node '%s': %s\n",
326 		       __func__, prop_name, fdt_get_name(blob, node, NULL),
327 			fdt_strerror(ret));
328 		return -ENOSPC;
329 	}
330 
331 	return 0;
332 }
333 
334 struct sandbox_state *state_get_current(void)
335 {
336 	assert(state);
337 	return state;
338 }
339 
340 void state_set_skip_delays(bool skip_delays)
341 {
342 	struct sandbox_state *state = state_get_current();
343 
344 	state->skip_delays = skip_delays;
345 }
346 
347 bool state_get_skip_delays(void)
348 {
349 	struct sandbox_state *state = state_get_current();
350 
351 	return state->skip_delays;
352 }
353 
354 int state_init(void)
355 {
356 	state = &main_state;
357 
358 	state->ram_size = CONFIG_SYS_SDRAM_SIZE;
359 	state->ram_buf = os_malloc(state->ram_size);
360 	assert(state->ram_buf);
361 
362 	/* No reset yet, so mark it as such. Always allow power reset */
363 	state->last_sysreset = SYSRESET_COUNT;
364 	state->sysreset_allowed[SYSRESET_POWER] = true;
365 
366 	/*
367 	 * Example of how to use GPIOs:
368 	 *
369 	 * sandbox_gpio_set_direction(170, 0);
370 	 * sandbox_gpio_set_value(170, 0);
371 	 */
372 	return 0;
373 }
374 
375 int state_uninit(void)
376 {
377 	int err;
378 
379 	state = &main_state;
380 
381 	if (state->write_ram_buf && !state->ram_buf_rm) {
382 		err = os_write_ram_buf(state->ram_buf_fname);
383 		if (err) {
384 			printf("Failed to write RAM buffer\n");
385 			return err;
386 		}
387 	}
388 
389 	if (state->write_state) {
390 		if (sandbox_write_state(state, state->state_fname)) {
391 			printf("Failed to write sandbox state\n");
392 			return -1;
393 		}
394 	}
395 
396 	/* Delete this at the last moment so as not to upset gdb too much */
397 	if (state->jumped_fname)
398 		os_unlink(state->jumped_fname);
399 
400 	if (state->state_fdt)
401 		os_free(state->state_fdt);
402 	memset(state, '\0', sizeof(*state));
403 
404 	return 0;
405 }
406