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 ret = -ENOMEM; 254 goto err_chunks; 255 } 256 257 dev_dbg(sram->dev, "found %sblock '%s' 0x%x-0x%x\n", 258 block->export ? "exported " : "", block->label, 259 block->start, block->start + block->size); 260 } else { 261 dev_dbg(sram->dev, "found reserved block 0x%x-0x%x\n", 262 block->start, block->start + block->size); 263 } 264 265 block++; 266 } 267 child = NULL; 268 269 /* the last chunk marks the end of the region */ 270 rblocks[nblocks - 1].start = size; 271 rblocks[nblocks - 1].size = 0; 272 list_add_tail(&rblocks[nblocks - 1].list, &reserve_list); 273 274 list_sort(NULL, &reserve_list, sram_reserve_cmp); 275 276 if (exports) { 277 sram->partition = devm_kzalloc(sram->dev, 278 exports * sizeof(*sram->partition), 279 GFP_KERNEL); 280 if (!sram->partition) { 281 ret = -ENOMEM; 282 goto err_chunks; 283 } 284 } 285 286 cur_start = 0; 287 list_for_each_entry(block, &reserve_list, list) { 288 /* can only happen if sections overlap */ 289 if (block->start < cur_start) { 290 dev_err(sram->dev, 291 "block at 0x%x starts after current offset 0x%lx\n", 292 block->start, cur_start); 293 ret = -EINVAL; 294 sram_free_partitions(sram); 295 goto err_chunks; 296 } 297 298 if ((block->export || block->pool) && block->size) { 299 ret = sram_add_partition(sram, block, 300 res->start + block->start); 301 if (ret) { 302 sram_free_partitions(sram); 303 goto err_chunks; 304 } 305 } 306 307 /* current start is in a reserved block, so continue after it */ 308 if (block->start == cur_start) { 309 cur_start = block->start + block->size; 310 continue; 311 } 312 313 /* 314 * allocate the space between the current starting 315 * address and the following reserved block, or the 316 * end of the region. 317 */ 318 cur_size = block->start - cur_start; 319 320 dev_dbg(sram->dev, "adding chunk 0x%lx-0x%lx\n", 321 cur_start, cur_start + cur_size); 322 323 ret = gen_pool_add_virt(sram->pool, 324 (unsigned long)sram->virt_base + cur_start, 325 res->start + cur_start, cur_size, -1); 326 if (ret < 0) { 327 sram_free_partitions(sram); 328 goto err_chunks; 329 } 330 331 /* next allocation after this reserved block */ 332 cur_start = block->start + block->size; 333 } 334 335 err_chunks: 336 if (child) 337 of_node_put(child); 338 339 kfree(rblocks); 340 341 return ret; 342 } 343 344 static int atmel_securam_wait(void) 345 { 346 struct regmap *regmap; 347 u32 val; 348 349 regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-secumod"); 350 if (IS_ERR(regmap)) 351 return -ENODEV; 352 353 return regmap_read_poll_timeout(regmap, AT91_SECUMOD_RAMRDY, val, 354 val & AT91_SECUMOD_RAMRDY_READY, 355 10000, 500000); 356 } 357 358 static const struct of_device_id sram_dt_ids[] = { 359 { .compatible = "mmio-sram" }, 360 { .compatible = "atmel,sama5d2-securam", .data = atmel_securam_wait }, 361 {} 362 }; 363 364 static int sram_probe(struct platform_device *pdev) 365 { 366 struct sram_dev *sram; 367 struct resource *res; 368 size_t size; 369 int ret; 370 int (*init_func)(void); 371 372 sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL); 373 if (!sram) 374 return -ENOMEM; 375 376 sram->dev = &pdev->dev; 377 378 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 379 if (!res) { 380 dev_err(sram->dev, "found no memory resource\n"); 381 return -EINVAL; 382 } 383 384 size = resource_size(res); 385 386 if (!devm_request_mem_region(sram->dev, res->start, size, pdev->name)) { 387 dev_err(sram->dev, "could not request region for resource\n"); 388 return -EBUSY; 389 } 390 391 if (of_property_read_bool(pdev->dev.of_node, "no-memory-wc")) 392 sram->virt_base = devm_ioremap(sram->dev, res->start, size); 393 else 394 sram->virt_base = devm_ioremap_wc(sram->dev, res->start, size); 395 if (!sram->virt_base) 396 return -ENOMEM; 397 398 sram->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY), 399 NUMA_NO_NODE, NULL); 400 if (IS_ERR(sram->pool)) 401 return PTR_ERR(sram->pool); 402 403 ret = sram_reserve_regions(sram, res); 404 if (ret) 405 return ret; 406 407 sram->clk = devm_clk_get(sram->dev, NULL); 408 if (IS_ERR(sram->clk)) 409 sram->clk = NULL; 410 else 411 clk_prepare_enable(sram->clk); 412 413 platform_set_drvdata(pdev, sram); 414 415 init_func = of_device_get_match_data(&pdev->dev); 416 if (init_func) { 417 ret = init_func(); 418 if (ret) 419 return ret; 420 } 421 422 dev_dbg(sram->dev, "SRAM pool: %zu KiB @ 0x%p\n", 423 gen_pool_size(sram->pool) / 1024, sram->virt_base); 424 425 return 0; 426 } 427 428 static int sram_remove(struct platform_device *pdev) 429 { 430 struct sram_dev *sram = platform_get_drvdata(pdev); 431 432 sram_free_partitions(sram); 433 434 if (gen_pool_avail(sram->pool) < gen_pool_size(sram->pool)) 435 dev_err(sram->dev, "removed while SRAM allocated\n"); 436 437 if (sram->clk) 438 clk_disable_unprepare(sram->clk); 439 440 return 0; 441 } 442 443 static struct platform_driver sram_driver = { 444 .driver = { 445 .name = "sram", 446 .of_match_table = sram_dt_ids, 447 }, 448 .probe = sram_probe, 449 .remove = sram_remove, 450 }; 451 452 static int __init sram_init(void) 453 { 454 return platform_driver_register(&sram_driver); 455 } 456 457 postcore_initcall(sram_init); 458