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 36 struct sram_partition { 37 void __iomem *base; 38 39 struct gen_pool *pool; 40 struct bin_attribute battr; 41 struct mutex lock; 42 }; 43 44 struct 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 55 struct 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 64 static 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 79 static 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 94 static 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 } 113 114 static 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 } 131 132 static 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 } 155 156 static 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 } 173 174 static 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 } 182 183 static 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 } 341 342 static 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 } 355 356 static const struct of_device_id sram_dt_ids[] = { 357 { .compatible = "mmio-sram" }, 358 { .compatible = "atmel,sama5d2-securam", .data = atmel_securam_wait }, 359 {} 360 }; 361 362 static 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 } 425 426 static 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 } 440 441 static 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 }; 449 450 static int __init sram_init(void) 451 { 452 return platform_driver_register(&sram_driver); 453 } 454 455 postcore_initcall(sram_init); 456