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