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
41static unsigned int burst_size;
42module_param(burst_size, uint, 0644);
43MODULE_PARM_DESC(burst_size, "Select burst byte size (0 unlimited)");
44
45struct 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
53struct stm32_crc_list {
54 struct list_head dev_list;
55 spinlock_t lock; /* protect dev_list */
56};
57
58static 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
63struct stm32_crc_ctx {
64 u32 key;
65 u32 poly;
66};
67
68struct stm32_crc_desc_ctx {
69 u32 partial; /* crc32c: partial in first 4 bytes of that struct */
70};
71
72static 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
81static 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
90static 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(p: key);
99 return 0;
100}
101
102static struct stm32_crc *stm32_crc_get_next_crc(void)
103{
104 struct stm32_crc *crc;
105
106 spin_lock_bh(lock: &crc_list.lock);
107 crc = list_first_entry(&crc_list.dev_list, struct stm32_crc, list);
108 if (crc)
109 list_move_tail(list: &crc->list, head: &crc_list.dev_list);
110 spin_unlock_bh(lock: &crc_list.lock);
111
112 return crc;
113}
114
115static 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(tfm: 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(dev: 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(lock: &crc->lock, flags);
140
141 pm_runtime_mark_last_busy(dev: crc->dev);
142 pm_runtime_put_autosuspend(dev: crc->dev);
143
144 return 0;
145}
146
147static 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(tfm: 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(dev: crc->dev);
159
160 if (!spin_trylock(lock: &crc->lock)) {
161 /* Hardware is busy, calculate crc32 by software */
162 if (mctx->poly == CRC32_POLY_LE)
163 ctx->partial = crc32_le(crc: ctx->partial, p: d8, len: length);
164 else
165 ctx->partial = __crc32c_le(crc: ctx->partial, p: d8, len: 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(lock: &crc->lock);
209
210pm_out:
211 pm_runtime_mark_last_busy(dev: crc->dev);
212 pm_runtime_put_autosuspend(dev: crc->dev);
213
214 return 0;
215}
216
217static 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, d8: cur, length: size);
235 if (ret)
236 return ret;
237 }
238
239 return 0;
240}
241
242static 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(tfm: desc->tfm);
246
247 /* Send computed CRC */
248 put_unaligned_le32(val: mctx->poly == CRC32C_POLY_LE ?
249 ~ctx->partial : ctx->partial, p: out);
250
251 return 0;
252}
253
254static int stm32_crc_finup(struct shash_desc *desc, const u8 *data,
255 unsigned int length, u8 *out)
256{
257 return stm32_crc_update(desc, d8: data, length) ?:
258 stm32_crc_final(desc, out);
259}
260
261static 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
267static unsigned int refcnt;
268static DEFINE_MUTEX(refcnt_lock);
269static 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_ctxsize = sizeof(struct stm32_crc_ctx),
287 .cra_module = THIS_MODULE,
288 .cra_init = stm32_crc32_cra_init,
289 }
290 },
291 /* CRC-32Castagnoli */
292 {
293 .setkey = stm32_crc_setkey,
294 .init = stm32_crc_init,
295 .update = stm32_crc_update,
296 .final = stm32_crc_final,
297 .finup = stm32_crc_finup,
298 .digest = stm32_crc_digest,
299 .descsize = sizeof(struct stm32_crc_desc_ctx),
300 .digestsize = CHKSUM_DIGEST_SIZE,
301 .base = {
302 .cra_name = "crc32c",
303 .cra_driver_name = "stm32-crc32-crc32c",
304 .cra_priority = 200,
305 .cra_flags = CRYPTO_ALG_OPTIONAL_KEY,
306 .cra_blocksize = CHKSUM_BLOCK_SIZE,
307 .cra_ctxsize = sizeof(struct stm32_crc_ctx),
308 .cra_module = THIS_MODULE,
309 .cra_init = stm32_crc32c_cra_init,
310 }
311 }
312};
313
314static int stm32_crc_probe(struct platform_device *pdev)
315{
316 struct device *dev = &pdev->dev;
317 struct stm32_crc *crc;
318 int ret;
319
320 crc = devm_kzalloc(dev, size: sizeof(*crc), GFP_KERNEL);
321 if (!crc)
322 return -ENOMEM;
323
324 crc->dev = dev;
325
326 crc->regs = devm_platform_ioremap_resource(pdev, index: 0);
327 if (IS_ERR(ptr: crc->regs)) {
328 dev_err(dev, "Cannot map CRC IO\n");
329 return PTR_ERR(ptr: crc->regs);
330 }
331
332 crc->clk = devm_clk_get(dev, NULL);
333 if (IS_ERR(ptr: crc->clk)) {
334 dev_err(dev, "Could not get clock\n");
335 return PTR_ERR(ptr: crc->clk);
336 }
337
338 ret = clk_prepare_enable(clk: crc->clk);
339 if (ret) {
340 dev_err(crc->dev, "Failed to enable clock\n");
341 return ret;
342 }
343
344 pm_runtime_set_autosuspend_delay(dev, CRC_AUTOSUSPEND_DELAY);
345 pm_runtime_use_autosuspend(dev);
346
347 pm_runtime_get_noresume(dev);
348 pm_runtime_set_active(dev);
349 pm_runtime_irq_safe(dev);
350 pm_runtime_enable(dev);
351
352 spin_lock_init(&crc->lock);
353
354 platform_set_drvdata(pdev, data: crc);
355
356 spin_lock(lock: &crc_list.lock);
357 list_add(new: &crc->list, head: &crc_list.dev_list);
358 spin_unlock(lock: &crc_list.lock);
359
360 mutex_lock(&refcnt_lock);
361 if (!refcnt) {
362 ret = crypto_register_shashes(algs, ARRAY_SIZE(algs));
363 if (ret) {
364 mutex_unlock(lock: &refcnt_lock);
365 dev_err(dev, "Failed to register\n");
366 clk_disable_unprepare(clk: crc->clk);
367 return ret;
368 }
369 }
370 refcnt++;
371 mutex_unlock(lock: &refcnt_lock);
372
373 dev_info(dev, "Initialized\n");
374
375 pm_runtime_put_sync(dev);
376
377 return 0;
378}
379
380static void stm32_crc_remove(struct platform_device *pdev)
381{
382 struct stm32_crc *crc = platform_get_drvdata(pdev);
383 int ret = pm_runtime_get_sync(dev: crc->dev);
384
385 spin_lock(lock: &crc_list.lock);
386 list_del(entry: &crc->list);
387 spin_unlock(lock: &crc_list.lock);
388
389 mutex_lock(&refcnt_lock);
390 if (!--refcnt)
391 crypto_unregister_shashes(algs, ARRAY_SIZE(algs));
392 mutex_unlock(lock: &refcnt_lock);
393
394 pm_runtime_disable(dev: crc->dev);
395 pm_runtime_put_noidle(dev: crc->dev);
396
397 if (ret >= 0)
398 clk_disable(clk: crc->clk);
399 clk_unprepare(clk: crc->clk);
400}
401
402static int __maybe_unused stm32_crc_suspend(struct device *dev)
403{
404 struct stm32_crc *crc = dev_get_drvdata(dev);
405 int ret;
406
407 ret = pm_runtime_force_suspend(dev);
408 if (ret)
409 return ret;
410
411 clk_unprepare(clk: crc->clk);
412
413 return 0;
414}
415
416static int __maybe_unused stm32_crc_resume(struct device *dev)
417{
418 struct stm32_crc *crc = dev_get_drvdata(dev);
419 int ret;
420
421 ret = clk_prepare(clk: crc->clk);
422 if (ret) {
423 dev_err(crc->dev, "Failed to prepare clock\n");
424 return ret;
425 }
426
427 return pm_runtime_force_resume(dev);
428}
429
430static int __maybe_unused stm32_crc_runtime_suspend(struct device *dev)
431{
432 struct stm32_crc *crc = dev_get_drvdata(dev);
433
434 clk_disable(clk: crc->clk);
435
436 return 0;
437}
438
439static int __maybe_unused stm32_crc_runtime_resume(struct device *dev)
440{
441 struct stm32_crc *crc = dev_get_drvdata(dev);
442 int ret;
443
444 ret = clk_enable(clk: crc->clk);
445 if (ret) {
446 dev_err(crc->dev, "Failed to enable clock\n");
447 return ret;
448 }
449
450 return 0;
451}
452
453static const struct dev_pm_ops stm32_crc_pm_ops = {
454 SET_SYSTEM_SLEEP_PM_OPS(stm32_crc_suspend,
455 stm32_crc_resume)
456 SET_RUNTIME_PM_OPS(stm32_crc_runtime_suspend,
457 stm32_crc_runtime_resume, NULL)
458};
459
460static const struct of_device_id stm32_dt_ids[] = {
461 { .compatible = "st,stm32f7-crc", },
462 {},
463};
464MODULE_DEVICE_TABLE(of, stm32_dt_ids);
465
466static struct platform_driver stm32_crc_driver = {
467 .probe = stm32_crc_probe,
468 .remove_new = stm32_crc_remove,
469 .driver = {
470 .name = DRIVER_NAME,
471 .pm = &stm32_crc_pm_ops,
472 .of_match_table = stm32_dt_ids,
473 },
474};
475
476module_platform_driver(stm32_crc_driver);
477
478MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>");
479MODULE_DESCRIPTION("STMicrolectronics STM32 CRC32 hardware driver");
480MODULE_LICENSE("GPL");
481

source code of linux/drivers/crypto/stm32/stm32-crc32.c