1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) STMicroelectronics SA 2017 4 * Author: Fabien Dessenne <fabien.dessenne@st.com> 5 */ 6 7 #include <linux/bitrev.h> 8 #include <linux/clk.h> 9 #include <linux/crc32.h> 10 #include <linux/crc32poly.h> 11 #include <linux/io.h> 12 #include <linux/kernel.h> 13 #include <linux/module.h> 14 #include <linux/mod_devicetable.h> 15 #include <linux/platform_device.h> 16 #include <linux/pm_runtime.h> 17 18 #include <crypto/internal/hash.h> 19 20 #include <asm/unaligned.h> 21 22 #define DRIVER_NAME "stm32-crc32" 23 #define CHKSUM_DIGEST_SIZE 4 24 #define CHKSUM_BLOCK_SIZE 1 25 26 /* Registers */ 27 #define CRC_DR 0x00000000 28 #define CRC_CR 0x00000008 29 #define CRC_INIT 0x00000010 30 #define CRC_POL 0x00000014 31 32 /* Registers values */ 33 #define CRC_CR_RESET BIT(0) 34 #define CRC_CR_REV_IN_WORD (BIT(6) | BIT(5)) 35 #define CRC_CR_REV_IN_BYTE BIT(5) 36 #define CRC_CR_REV_OUT BIT(7) 37 #define CRC32C_INIT_DEFAULT 0xFFFFFFFF 38 39 #define CRC_AUTOSUSPEND_DELAY 50 40 41 static unsigned int burst_size; 42 module_param(burst_size, uint, 0644); 43 MODULE_PARM_DESC(burst_size, "Select burst byte size (0 unlimited)"); 44 45 struct stm32_crc { 46 struct list_head list; 47 struct device *dev; 48 void __iomem *regs; 49 struct clk *clk; 50 spinlock_t lock; 51 }; 52 53 struct stm32_crc_list { 54 struct list_head dev_list; 55 spinlock_t lock; /* protect dev_list */ 56 }; 57 58 static struct stm32_crc_list crc_list = { 59 .dev_list = LIST_HEAD_INIT(crc_list.dev_list), 60 .lock = __SPIN_LOCK_UNLOCKED(crc_list.lock), 61 }; 62 63 struct stm32_crc_ctx { 64 u32 key; 65 u32 poly; 66 }; 67 68 struct stm32_crc_desc_ctx { 69 u32 partial; /* crc32c: partial in first 4 bytes of that struct */ 70 }; 71 72 static int stm32_crc32_cra_init(struct crypto_tfm *tfm) 73 { 74 struct stm32_crc_ctx *mctx = crypto_tfm_ctx(tfm); 75 76 mctx->key = 0; 77 mctx->poly = CRC32_POLY_LE; 78 return 0; 79 } 80 81 static int stm32_crc32c_cra_init(struct crypto_tfm *tfm) 82 { 83 struct stm32_crc_ctx *mctx = crypto_tfm_ctx(tfm); 84 85 mctx->key = CRC32C_INIT_DEFAULT; 86 mctx->poly = CRC32C_POLY_LE; 87 return 0; 88 } 89 90 static int stm32_crc_setkey(struct crypto_shash *tfm, const u8 *key, 91 unsigned int keylen) 92 { 93 struct stm32_crc_ctx *mctx = crypto_shash_ctx(tfm); 94 95 if (keylen != sizeof(u32)) 96 return -EINVAL; 97 98 mctx->key = get_unaligned_le32(key); 99 return 0; 100 } 101 102 static struct stm32_crc *stm32_crc_get_next_crc(void) 103 { 104 struct stm32_crc *crc; 105 106 spin_lock_bh(&crc_list.lock); 107 crc = list_first_entry(&crc_list.dev_list, struct stm32_crc, list); 108 if (crc) 109 list_move_tail(&crc->list, &crc_list.dev_list); 110 spin_unlock_bh(&crc_list.lock); 111 112 return crc; 113 } 114 115 static int stm32_crc_init(struct shash_desc *desc) 116 { 117 struct stm32_crc_desc_ctx *ctx = shash_desc_ctx(desc); 118 struct stm32_crc_ctx *mctx = crypto_shash_ctx(desc->tfm); 119 struct stm32_crc *crc; 120 unsigned long flags; 121 122 crc = stm32_crc_get_next_crc(); 123 if (!crc) 124 return -ENODEV; 125 126 pm_runtime_get_sync(crc->dev); 127 128 spin_lock_irqsave(&crc->lock, flags); 129 130 /* Reset, set key, poly and configure in bit reverse mode */ 131 writel_relaxed(bitrev32(mctx->key), crc->regs + CRC_INIT); 132 writel_relaxed(bitrev32(mctx->poly), crc->regs + CRC_POL); 133 writel_relaxed(CRC_CR_RESET | CRC_CR_REV_IN_WORD | CRC_CR_REV_OUT, 134 crc->regs + CRC_CR); 135 136 /* Store partial result */ 137 ctx->partial = readl_relaxed(crc->regs + CRC_DR); 138 139 spin_unlock_irqrestore(&crc->lock, flags); 140 141 pm_runtime_mark_last_busy(crc->dev); 142 pm_runtime_put_autosuspend(crc->dev); 143 144 return 0; 145 } 146 147 static int burst_update(struct shash_desc *desc, const u8 *d8, 148 size_t length) 149 { 150 struct stm32_crc_desc_ctx *ctx = shash_desc_ctx(desc); 151 struct stm32_crc_ctx *mctx = crypto_shash_ctx(desc->tfm); 152 struct stm32_crc *crc; 153 154 crc = stm32_crc_get_next_crc(); 155 if (!crc) 156 return -ENODEV; 157 158 pm_runtime_get_sync(crc->dev); 159 160 if (!spin_trylock(&crc->lock)) { 161 /* Hardware is busy, calculate crc32 by software */ 162 if (mctx->poly == CRC32_POLY_LE) 163 ctx->partial = crc32_le(ctx->partial, d8, length); 164 else 165 ctx->partial = __crc32c_le(ctx->partial, d8, length); 166 167 goto pm_out; 168 } 169 170 /* 171 * Restore previously calculated CRC for this context as init value 172 * Restore polynomial configuration 173 * Configure in register for word input data, 174 * Configure out register in reversed bit mode data. 175 */ 176 writel_relaxed(bitrev32(ctx->partial), crc->regs + CRC_INIT); 177 writel_relaxed(bitrev32(mctx->poly), crc->regs + CRC_POL); 178 writel_relaxed(CRC_CR_RESET | CRC_CR_REV_IN_WORD | CRC_CR_REV_OUT, 179 crc->regs + CRC_CR); 180 181 if (d8 != PTR_ALIGN(d8, sizeof(u32))) { 182 /* Configure for byte data */ 183 writel_relaxed(CRC_CR_REV_IN_BYTE | CRC_CR_REV_OUT, 184 crc->regs + CRC_CR); 185 while (d8 != PTR_ALIGN(d8, sizeof(u32)) && length) { 186 writeb_relaxed(*d8++, crc->regs + CRC_DR); 187 length--; 188 } 189 /* Configure for word data */ 190 writel_relaxed(CRC_CR_REV_IN_WORD | CRC_CR_REV_OUT, 191 crc->regs + CRC_CR); 192 } 193 194 for (; length >= sizeof(u32); d8 += sizeof(u32), length -= sizeof(u32)) 195 writel_relaxed(*((u32 *)d8), crc->regs + CRC_DR); 196 197 if (length) { 198 /* Configure for byte data */ 199 writel_relaxed(CRC_CR_REV_IN_BYTE | CRC_CR_REV_OUT, 200 crc->regs + CRC_CR); 201 while (length--) 202 writeb_relaxed(*d8++, crc->regs + CRC_DR); 203 } 204 205 /* Store partial result */ 206 ctx->partial = readl_relaxed(crc->regs + CRC_DR); 207 208 spin_unlock(&crc->lock); 209 210 pm_out: 211 pm_runtime_mark_last_busy(crc->dev); 212 pm_runtime_put_autosuspend(crc->dev); 213 214 return 0; 215 } 216 217 static int stm32_crc_update(struct shash_desc *desc, const u8 *d8, 218 unsigned int length) 219 { 220 const unsigned int burst_sz = burst_size; 221 unsigned int rem_sz; 222 const u8 *cur; 223 size_t size; 224 int ret; 225 226 if (!burst_sz) 227 return burst_update(desc, d8, length); 228 229 /* Digest first bytes not 32bit aligned at first pass in the loop */ 230 size = min_t(size_t, length, burst_sz + (size_t)d8 - 231 ALIGN_DOWN((size_t)d8, sizeof(u32))); 232 for (rem_sz = length, cur = d8; rem_sz; 233 rem_sz -= size, cur += size, size = min(rem_sz, burst_sz)) { 234 ret = burst_update(desc, cur, size); 235 if (ret) 236 return ret; 237 } 238 239 return 0; 240 } 241 242 static int stm32_crc_final(struct shash_desc *desc, u8 *out) 243 { 244 struct stm32_crc_desc_ctx *ctx = shash_desc_ctx(desc); 245 struct stm32_crc_ctx *mctx = crypto_shash_ctx(desc->tfm); 246 247 /* Send computed CRC */ 248 put_unaligned_le32(mctx->poly == CRC32C_POLY_LE ? 249 ~ctx->partial : ctx->partial, out); 250 251 return 0; 252 } 253 254 static int stm32_crc_finup(struct shash_desc *desc, const u8 *data, 255 unsigned int length, u8 *out) 256 { 257 return stm32_crc_update(desc, data, length) ?: 258 stm32_crc_final(desc, out); 259 } 260 261 static int stm32_crc_digest(struct shash_desc *desc, const u8 *data, 262 unsigned int length, u8 *out) 263 { 264 return stm32_crc_init(desc) ?: stm32_crc_finup(desc, data, length, out); 265 } 266 267 static unsigned int refcnt; 268 static DEFINE_MUTEX(refcnt_lock); 269 static struct shash_alg algs[] = { 270 /* CRC-32 */ 271 { 272 .setkey = stm32_crc_setkey, 273 .init = stm32_crc_init, 274 .update = stm32_crc_update, 275 .final = stm32_crc_final, 276 .finup = stm32_crc_finup, 277 .digest = stm32_crc_digest, 278 .descsize = sizeof(struct stm32_crc_desc_ctx), 279 .digestsize = CHKSUM_DIGEST_SIZE, 280 .base = { 281 .cra_name = "crc32", 282 .cra_driver_name = "stm32-crc32-crc32", 283 .cra_priority = 200, 284 .cra_flags = CRYPTO_ALG_OPTIONAL_KEY, 285 .cra_blocksize = CHKSUM_BLOCK_SIZE, 286 .cra_alignmask = 3, 287 .cra_ctxsize = sizeof(struct stm32_crc_ctx), 288 .cra_module = THIS_MODULE, 289 .cra_init = stm32_crc32_cra_init, 290 } 291 }, 292 /* CRC-32Castagnoli */ 293 { 294 .setkey = stm32_crc_setkey, 295 .init = stm32_crc_init, 296 .update = stm32_crc_update, 297 .final = stm32_crc_final, 298 .finup = stm32_crc_finup, 299 .digest = stm32_crc_digest, 300 .descsize = sizeof(struct stm32_crc_desc_ctx), 301 .digestsize = CHKSUM_DIGEST_SIZE, 302 .base = { 303 .cra_name = "crc32c", 304 .cra_driver_name = "stm32-crc32-crc32c", 305 .cra_priority = 200, 306 .cra_flags = CRYPTO_ALG_OPTIONAL_KEY, 307 .cra_blocksize = CHKSUM_BLOCK_SIZE, 308 .cra_alignmask = 3, 309 .cra_ctxsize = sizeof(struct stm32_crc_ctx), 310 .cra_module = THIS_MODULE, 311 .cra_init = stm32_crc32c_cra_init, 312 } 313 } 314 }; 315 316 static int stm32_crc_probe(struct platform_device *pdev) 317 { 318 struct device *dev = &pdev->dev; 319 struct stm32_crc *crc; 320 int ret; 321 322 crc = devm_kzalloc(dev, sizeof(*crc), GFP_KERNEL); 323 if (!crc) 324 return -ENOMEM; 325 326 crc->dev = dev; 327 328 crc->regs = devm_platform_ioremap_resource(pdev, 0); 329 if (IS_ERR(crc->regs)) { 330 dev_err(dev, "Cannot map CRC IO\n"); 331 return PTR_ERR(crc->regs); 332 } 333 334 crc->clk = devm_clk_get(dev, NULL); 335 if (IS_ERR(crc->clk)) { 336 dev_err(dev, "Could not get clock\n"); 337 return PTR_ERR(crc->clk); 338 } 339 340 ret = clk_prepare_enable(crc->clk); 341 if (ret) { 342 dev_err(crc->dev, "Failed to enable clock\n"); 343 return ret; 344 } 345 346 pm_runtime_set_autosuspend_delay(dev, CRC_AUTOSUSPEND_DELAY); 347 pm_runtime_use_autosuspend(dev); 348 349 pm_runtime_get_noresume(dev); 350 pm_runtime_set_active(dev); 351 pm_runtime_irq_safe(dev); 352 pm_runtime_enable(dev); 353 354 spin_lock_init(&crc->lock); 355 356 platform_set_drvdata(pdev, crc); 357 358 spin_lock(&crc_list.lock); 359 list_add(&crc->list, &crc_list.dev_list); 360 spin_unlock(&crc_list.lock); 361 362 mutex_lock(&refcnt_lock); 363 if (!refcnt) { 364 ret = crypto_register_shashes(algs, ARRAY_SIZE(algs)); 365 if (ret) { 366 mutex_unlock(&refcnt_lock); 367 dev_err(dev, "Failed to register\n"); 368 clk_disable_unprepare(crc->clk); 369 return ret; 370 } 371 } 372 refcnt++; 373 mutex_unlock(&refcnt_lock); 374 375 dev_info(dev, "Initialized\n"); 376 377 pm_runtime_put_sync(dev); 378 379 return 0; 380 } 381 382 static int stm32_crc_remove(struct platform_device *pdev) 383 { 384 struct stm32_crc *crc = platform_get_drvdata(pdev); 385 int ret = pm_runtime_get_sync(crc->dev); 386 387 if (ret < 0) { 388 pm_runtime_put_noidle(crc->dev); 389 return ret; 390 } 391 392 spin_lock(&crc_list.lock); 393 list_del(&crc->list); 394 spin_unlock(&crc_list.lock); 395 396 mutex_lock(&refcnt_lock); 397 if (!--refcnt) 398 crypto_unregister_shashes(algs, ARRAY_SIZE(algs)); 399 mutex_unlock(&refcnt_lock); 400 401 pm_runtime_disable(crc->dev); 402 pm_runtime_put_noidle(crc->dev); 403 404 clk_disable_unprepare(crc->clk); 405 406 return 0; 407 } 408 409 static int __maybe_unused stm32_crc_suspend(struct device *dev) 410 { 411 struct stm32_crc *crc = dev_get_drvdata(dev); 412 int ret; 413 414 ret = pm_runtime_force_suspend(dev); 415 if (ret) 416 return ret; 417 418 clk_unprepare(crc->clk); 419 420 return 0; 421 } 422 423 static int __maybe_unused stm32_crc_resume(struct device *dev) 424 { 425 struct stm32_crc *crc = dev_get_drvdata(dev); 426 int ret; 427 428 ret = clk_prepare(crc->clk); 429 if (ret) { 430 dev_err(crc->dev, "Failed to prepare clock\n"); 431 return ret; 432 } 433 434 return pm_runtime_force_resume(dev); 435 } 436 437 static int __maybe_unused stm32_crc_runtime_suspend(struct device *dev) 438 { 439 struct stm32_crc *crc = dev_get_drvdata(dev); 440 441 clk_disable(crc->clk); 442 443 return 0; 444 } 445 446 static int __maybe_unused stm32_crc_runtime_resume(struct device *dev) 447 { 448 struct stm32_crc *crc = dev_get_drvdata(dev); 449 int ret; 450 451 ret = clk_enable(crc->clk); 452 if (ret) { 453 dev_err(crc->dev, "Failed to enable clock\n"); 454 return ret; 455 } 456 457 return 0; 458 } 459 460 static const struct dev_pm_ops stm32_crc_pm_ops = { 461 SET_SYSTEM_SLEEP_PM_OPS(stm32_crc_suspend, 462 stm32_crc_resume) 463 SET_RUNTIME_PM_OPS(stm32_crc_runtime_suspend, 464 stm32_crc_runtime_resume, NULL) 465 }; 466 467 static const struct of_device_id stm32_dt_ids[] = { 468 { .compatible = "st,stm32f7-crc", }, 469 {}, 470 }; 471 MODULE_DEVICE_TABLE(of, stm32_dt_ids); 472 473 static struct platform_driver stm32_crc_driver = { 474 .probe = stm32_crc_probe, 475 .remove = stm32_crc_remove, 476 .driver = { 477 .name = DRIVER_NAME, 478 .pm = &stm32_crc_pm_ops, 479 .of_match_table = stm32_dt_ids, 480 }, 481 }; 482 483 module_platform_driver(stm32_crc_driver); 484 485 MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>"); 486 MODULE_DESCRIPTION("STMicrolectronics STM32 CRC32 hardware driver"); 487 MODULE_LICENSE("GPL"); 488