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1/*
2 * Generic on-chip SRAM allocation driver
3 *
4 * Copyright (C) 2012 Philipp Zabel, Pengutronix
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version 2
9 * of the License, or (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
18 * MA 02110-1301, USA.
19 */
20
21#include <linux/clk.h>
22#include <linux/delay.h>
23#include <linux/genalloc.h>
24#include <linux/io.h>
25#include <linux/list_sort.h>
26#include <linux/of_address.h>
27#include <linux/of_device.h>
28#include <linux/platform_device.h>
29#include <linux/regmap.h>
30#include <linux/slab.h>
31#include <linux/mfd/syscon.h>
32#include <soc/at91/atmel-secumod.h>
33
34#define SRAM_GRANULARITY 32
35
36struct sram_partition {
37 void __iomem *base;
38
39 struct gen_pool *pool;
40 struct bin_attribute battr;
41 struct mutex lock;
42};
43
44struct sram_dev {
45 struct device *dev;
46 void __iomem *virt_base;
47
48 struct gen_pool *pool;
49 struct clk *clk;
50
51 struct sram_partition *partition;
52 u32 partitions;
53};
54
55struct sram_reserve {
56 struct list_head list;
57 u32 start;
58 u32 size;
59 bool export;
60 bool pool;
61 const char *label;
62};
63
64static ssize_t sram_read(struct file *filp, struct kobject *kobj,
65 struct bin_attribute *attr,
66 char *buf, loff_t pos, size_t count)
67{
68 struct sram_partition *part;
69
70 part = container_of(attr, struct sram_partition, battr);
71
72 mutex_lock(&part->lock);
73 memcpy_fromio(buf, part->base + pos, count);
74 mutex_unlock(&part->lock);
75
76 return count;
77}
78
79static ssize_t sram_write(struct file *filp, struct kobject *kobj,
80 struct bin_attribute *attr,
81 char *buf, loff_t pos, size_t count)
82{
83 struct sram_partition *part;
84
85 part = container_of(attr, struct sram_partition, battr);
86
87 mutex_lock(&part->lock);
88 memcpy_toio(part->base + pos, buf, count);
89 mutex_unlock(&part->lock);
90
91 return count;
92}
93
94static int sram_add_pool(struct sram_dev *sram, struct sram_reserve *block,
95 phys_addr_t start, struct sram_partition *part)
96{
97 int ret;
98
99 part->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY),
100 NUMA_NO_NODE, block->label);
101 if (IS_ERR(part->pool))
102 return PTR_ERR(part->pool);
103
104 ret = gen_pool_add_virt(part->pool, (unsigned long)part->base, start,
105 block->size, NUMA_NO_NODE);
106 if (ret < 0) {
107 dev_err(sram->dev, "failed to register subpool: %d\n", ret);
108 return ret;
109 }
110
111 return 0;
112}
113
114static int sram_add_export(struct sram_dev *sram, struct sram_reserve *block,
115 phys_addr_t start, struct sram_partition *part)
116{
117 sysfs_bin_attr_init(&part->battr);
118 part->battr.attr.name = devm_kasprintf(sram->dev, GFP_KERNEL,
119 "%llx.sram",
120 (unsigned long long)start);
121 if (!part->battr.attr.name)
122 return -ENOMEM;
123
124 part->battr.attr.mode = S_IRUSR | S_IWUSR;
125 part->battr.read = sram_read;
126 part->battr.write = sram_write;
127 part->battr.size = block->size;
128
129 return device_create_bin_file(sram->dev, &part->battr);
130}
131
132static int sram_add_partition(struct sram_dev *sram, struct sram_reserve *block,
133 phys_addr_t start)
134{
135 int ret;
136 struct sram_partition *part = &sram->partition[sram->partitions];
137
138 mutex_init(&part->lock);
139 part->base = sram->virt_base + block->start;
140
141 if (block->pool) {
142 ret = sram_add_pool(sram, block, start, part);
143 if (ret)
144 return ret;
145 }
146 if (block->export) {
147 ret = sram_add_export(sram, block, start, part);
148 if (ret)
149 return ret;
150 }
151 sram->partitions++;
152
153 return 0;
154}
155
156static void sram_free_partitions(struct sram_dev *sram)
157{
158 struct sram_partition *part;
159
160 if (!sram->partitions)
161 return;
162
163 part = &sram->partition[sram->partitions - 1];
164 for (; sram->partitions; sram->partitions--, part--) {
165 if (part->battr.size)
166 device_remove_bin_file(sram->dev, &part->battr);
167
168 if (part->pool &&
169 gen_pool_avail(part->pool) < gen_pool_size(part->pool))
170 dev_err(sram->dev, "removed pool while SRAM allocated\n");
171 }
172}
173
174static int sram_reserve_cmp(void *priv, struct list_head *a,
175 struct list_head *b)
176{
177 struct sram_reserve *ra = list_entry(a, struct sram_reserve, list);
178 struct sram_reserve *rb = list_entry(b, struct sram_reserve, list);
179
180 return ra->start - rb->start;
181}
182
183static int sram_reserve_regions(struct sram_dev *sram, struct resource *res)
184{
185 struct device_node *np = sram->dev->of_node, *child;
186 unsigned long size, cur_start, cur_size;
187 struct sram_reserve *rblocks, *block;
188 struct list_head reserve_list;
189 unsigned int nblocks, exports = 0;
190 const char *label;
191 int ret = 0;
192
193 INIT_LIST_HEAD(&reserve_list);
194
195 size = resource_size(res);
196
197 /*
198 * We need an additional block to mark the end of the memory region
199 * after the reserved blocks from the dt are processed.
200 */
201 nblocks = (np) ? of_get_available_child_count(np) + 1 : 1;
202 rblocks = kzalloc((nblocks) * sizeof(*rblocks), GFP_KERNEL);
203 if (!rblocks)
204 return -ENOMEM;
205
206 block = &rblocks[0];
207 for_each_available_child_of_node(np, child) {
208 struct resource child_res;
209
210 ret = of_address_to_resource(child, 0, &child_res);
211 if (ret < 0) {
212 dev_err(sram->dev,
213 "could not get address for node %s\n",
214 child->full_name);
215 goto err_chunks;
216 }
217
218 if (child_res.start < res->start || child_res.end > res->end) {
219 dev_err(sram->dev,
220 "reserved block %s outside the sram area\n",
221 child->full_name);
222 ret = -EINVAL;
223 goto err_chunks;
224 }
225
226 block->start = child_res.start - res->start;
227 block->size = resource_size(&child_res);
228 list_add_tail(&block->list, &reserve_list);
229
230 if (of_find_property(child, "export", NULL))
231 block->export = true;
232
233 if (of_find_property(child, "pool", NULL))
234 block->pool = true;
235
236 if ((block->export || block->pool) && block->size) {
237 exports++;
238
239 label = NULL;
240 ret = of_property_read_string(child, "label", &label);
241 if (ret && ret != -EINVAL) {
242 dev_err(sram->dev,
243 "%s has invalid label name\n",
244 child->full_name);
245 goto err_chunks;
246 }
247 if (!label)
248 label = child->name;
249
250 block->label = devm_kstrdup(sram->dev,
251 label, GFP_KERNEL);
252 if (!block->label)
253 goto err_chunks;
254
255 dev_dbg(sram->dev, "found %sblock '%s' 0x%x-0x%x\n",
256 block->export ? "exported " : "", block->label,
257 block->start, block->start + block->size);
258 } else {
259 dev_dbg(sram->dev, "found reserved block 0x%x-0x%x\n",
260 block->start, block->start + block->size);
261 }
262
263 block++;
264 }
265 child = NULL;
266
267 /* the last chunk marks the end of the region */
268 rblocks[nblocks - 1].start = size;
269 rblocks[nblocks - 1].size = 0;
270 list_add_tail(&rblocks[nblocks - 1].list, &reserve_list);
271
272 list_sort(NULL, &reserve_list, sram_reserve_cmp);
273
274 if (exports) {
275 sram->partition = devm_kzalloc(sram->dev,
276 exports * sizeof(*sram->partition),
277 GFP_KERNEL);
278 if (!sram->partition) {
279 ret = -ENOMEM;
280 goto err_chunks;
281 }
282 }
283
284 cur_start = 0;
285 list_for_each_entry(block, &reserve_list, list) {
286 /* can only happen if sections overlap */
287 if (block->start < cur_start) {
288 dev_err(sram->dev,
289 "block at 0x%x starts after current offset 0x%lx\n",
290 block->start, cur_start);
291 ret = -EINVAL;
292 sram_free_partitions(sram);
293 goto err_chunks;
294 }
295
296 if ((block->export || block->pool) && block->size) {
297 ret = sram_add_partition(sram, block,
298 res->start + block->start);
299 if (ret) {
300 sram_free_partitions(sram);
301 goto err_chunks;
302 }
303 }
304
305 /* current start is in a reserved block, so continue after it */
306 if (block->start == cur_start) {
307 cur_start = block->start + block->size;
308 continue;
309 }
310
311 /*
312 * allocate the space between the current starting
313 * address and the following reserved block, or the
314 * end of the region.
315 */
316 cur_size = block->start - cur_start;
317
318 dev_dbg(sram->dev, "adding chunk 0x%lx-0x%lx\n",
319 cur_start, cur_start + cur_size);
320
321 ret = gen_pool_add_virt(sram->pool,
322 (unsigned long)sram->virt_base + cur_start,
323 res->start + cur_start, cur_size, -1);
324 if (ret < 0) {
325 sram_free_partitions(sram);
326 goto err_chunks;
327 }
328
329 /* next allocation after this reserved block */
330 cur_start = block->start + block->size;
331 }
332
333 err_chunks:
334 if (child)
335 of_node_put(child);
336
337 kfree(rblocks);
338
339 return ret;
340}
341
342static int atmel_securam_wait(void)
343{
344 struct regmap *regmap;
345 u32 val;
346
347 regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-secumod");
348 if (IS_ERR(regmap))
349 return -ENODEV;
350
351 return regmap_read_poll_timeout(regmap, AT91_SECUMOD_RAMRDY, val,
352 val & AT91_SECUMOD_RAMRDY_READY,
353 10000, 500000);
354}
355
356static const struct of_device_id sram_dt_ids[] = {
357 { .compatible = "mmio-sram" },
358 { .compatible = "atmel,sama5d2-securam", .data = atmel_securam_wait },
359 {}
360};
361
362static int sram_probe(struct platform_device *pdev)
363{
364 struct sram_dev *sram;
365 struct resource *res;
366 size_t size;
367 int ret;
368 int (*init_func)(void);
369
370 sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL);
371 if (!sram)
372 return -ENOMEM;
373
374 sram->dev = &pdev->dev;
375
376 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
377 if (!res) {
378 dev_err(sram->dev, "found no memory resource\n");
379 return -EINVAL;
380 }
381
382 size = resource_size(res);
383
384 if (!devm_request_mem_region(sram->dev, res->start, size, pdev->name)) {
385 dev_err(sram->dev, "could not request region for resource\n");
386 return -EBUSY;
387 }
388
389 if (of_property_read_bool(pdev->dev.of_node, "no-memory-wc"))
390 sram->virt_base = devm_ioremap(sram->dev, res->start, size);
391 else
392 sram->virt_base = devm_ioremap_wc(sram->dev, res->start, size);
393 if (!sram->virt_base)
394 return -ENOMEM;
395
396 sram->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY),
397 NUMA_NO_NODE, NULL);
398 if (IS_ERR(sram->pool))
399 return PTR_ERR(sram->pool);
400
401 ret = sram_reserve_regions(sram, res);
402 if (ret)
403 return ret;
404
405 sram->clk = devm_clk_get(sram->dev, NULL);
406 if (IS_ERR(sram->clk))
407 sram->clk = NULL;
408 else
409 clk_prepare_enable(sram->clk);
410
411 platform_set_drvdata(pdev, sram);
412
413 init_func = of_device_get_match_data(&pdev->dev);
414 if (init_func) {
415 ret = init_func();
416 if (ret)
417 return ret;
418 }
419
420 dev_dbg(sram->dev, "SRAM pool: %zu KiB @ 0x%p\n",
421 gen_pool_size(sram->pool) / 1024, sram->virt_base);
422
423 return 0;
424}
425
426static int sram_remove(struct platform_device *pdev)
427{
428 struct sram_dev *sram = platform_get_drvdata(pdev);
429
430 sram_free_partitions(sram);
431
432 if (gen_pool_avail(sram->pool) < gen_pool_size(sram->pool))
433 dev_err(sram->dev, "removed while SRAM allocated\n");
434
435 if (sram->clk)
436 clk_disable_unprepare(sram->clk);
437
438 return 0;
439}
440
441static struct platform_driver sram_driver = {
442 .driver = {
443 .name = "sram",
444 .of_match_table = sram_dt_ids,
445 },
446 .probe = sram_probe,
447 .remove = sram_remove,
448};
449
450static int __init sram_init(void)
451{
452 return platform_driver_register(&sram_driver);
453}
454
455postcore_initcall(sram_init);