1 // SPDX-License-Identifier: GPL-2.0 OR MIT
2 /*
3 * MTK ECC controller driver.
4 * Copyright (C) 2016 MediaTek Inc.
5 * Authors: Xiaolei Li <xiaolei.li@mediatek.com>
6 * Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
7 */
8
9 #include <linux/platform_device.h>
10 #include <linux/dma-mapping.h>
11 #include <linux/interrupt.h>
12 #include <linux/clk.h>
13 #include <linux/module.h>
14 #include <linux/iopoll.h>
15 #include <linux/of.h>
16 #include <linux/of_platform.h>
17 #include <linux/mutex.h>
18 #include <linux/mtd/nand-ecc-mtk.h>
19
20 #define ECC_IDLE_MASK BIT(0)
21 #define ECC_IRQ_EN BIT(0)
22 #define ECC_PG_IRQ_SEL BIT(1)
23 #define ECC_OP_ENABLE (1)
24 #define ECC_OP_DISABLE (0)
25
26 #define ECC_ENCCON (0x00)
27 #define ECC_ENCCNFG (0x04)
28 #define ECC_MS_SHIFT (16)
29 #define ECC_ENCDIADDR (0x08)
30 #define ECC_ENCIDLE (0x0C)
31 #define ECC_DECCON (0x100)
32 #define ECC_DECCNFG (0x104)
33 #define DEC_EMPTY_EN BIT(31)
34 #define DEC_CNFG_CORRECT (0x3 << 12)
35 #define ECC_DECIDLE (0x10C)
36 #define ECC_DECENUM0 (0x114)
37
38 #define ECC_TIMEOUT (500000)
39
40 #define ECC_IDLE_REG(op) ((op) == ECC_ENCODE ? ECC_ENCIDLE : ECC_DECIDLE)
41 #define ECC_CTL_REG(op) ((op) == ECC_ENCODE ? ECC_ENCCON : ECC_DECCON)
42
43 #define ECC_ERRMASK_MT7622 GENMASK(4, 0)
44 #define ECC_ERRMASK_MT2701 GENMASK(5, 0)
45 #define ECC_ERRMASK_MT2712 GENMASK(6, 0)
46
47 struct mtk_ecc_caps {
48 u32 err_mask;
49 u32 err_shift;
50 const u8 *ecc_strength;
51 const u32 *ecc_regs;
52 u8 num_ecc_strength;
53 u8 ecc_mode_shift;
54 u32 parity_bits;
55 int pg_irq_sel;
56 };
57
58 struct mtk_ecc {
59 struct device *dev;
60 const struct mtk_ecc_caps *caps;
61 void __iomem *regs;
62 struct clk *clk;
63
64 struct completion done;
65 struct mutex lock;
66 u32 sectors;
67
68 u8 *eccdata;
69 };
70
71 /* ecc strength that each IP supports */
72 static const u8 ecc_strength_mt2701[] = {
73 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 28, 32, 36,
74 40, 44, 48, 52, 56, 60
75 };
76
77 static const u8 ecc_strength_mt2712[] = {
78 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 28, 32, 36,
79 40, 44, 48, 52, 56, 60, 68, 72, 80
80 };
81
82 static const u8 ecc_strength_mt7622[] = {
83 4, 6, 8, 10, 12
84 };
85
86 static const u8 ecc_strength_mt7986[] = {
87 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24
88 };
89
90 enum mtk_ecc_regs {
91 ECC_ENCPAR00,
92 ECC_ENCIRQ_EN,
93 ECC_ENCIRQ_STA,
94 ECC_DECDONE,
95 ECC_DECIRQ_EN,
96 ECC_DECIRQ_STA,
97 };
98
99 static int mt2701_ecc_regs[] = {
100 [ECC_ENCPAR00] = 0x10,
101 [ECC_ENCIRQ_EN] = 0x80,
102 [ECC_ENCIRQ_STA] = 0x84,
103 [ECC_DECDONE] = 0x124,
104 [ECC_DECIRQ_EN] = 0x200,
105 [ECC_DECIRQ_STA] = 0x204,
106 };
107
108 static int mt2712_ecc_regs[] = {
109 [ECC_ENCPAR00] = 0x300,
110 [ECC_ENCIRQ_EN] = 0x80,
111 [ECC_ENCIRQ_STA] = 0x84,
112 [ECC_DECDONE] = 0x124,
113 [ECC_DECIRQ_EN] = 0x200,
114 [ECC_DECIRQ_STA] = 0x204,
115 };
116
117 static int mt7622_ecc_regs[] = {
118 [ECC_ENCPAR00] = 0x10,
119 [ECC_ENCIRQ_EN] = 0x30,
120 [ECC_ENCIRQ_STA] = 0x34,
121 [ECC_DECDONE] = 0x11c,
122 [ECC_DECIRQ_EN] = 0x140,
123 [ECC_DECIRQ_STA] = 0x144,
124 };
125
mtk_ecc_wait_idle(struct mtk_ecc * ecc,enum mtk_ecc_operation op)126 static inline void mtk_ecc_wait_idle(struct mtk_ecc *ecc,
127 enum mtk_ecc_operation op)
128 {
129 struct device *dev = ecc->dev;
130 u32 val;
131 int ret;
132
133 ret = readl_poll_timeout_atomic(ecc->regs + ECC_IDLE_REG(op), val,
134 val & ECC_IDLE_MASK,
135 10, ECC_TIMEOUT);
136 if (ret)
137 dev_warn(dev, "%s NOT idle\n",
138 op == ECC_ENCODE ? "encoder" : "decoder");
139 }
140
mtk_ecc_irq(int irq,void * id)141 static irqreturn_t mtk_ecc_irq(int irq, void *id)
142 {
143 struct mtk_ecc *ecc = id;
144 u32 dec, enc;
145
146 dec = readw(ecc->regs + ecc->caps->ecc_regs[ECC_DECIRQ_STA])
147 & ECC_IRQ_EN;
148 if (dec) {
149 dec = readw(ecc->regs + ecc->caps->ecc_regs[ECC_DECDONE]);
150 if (dec & ecc->sectors) {
151 /*
152 * Clear decode IRQ status once again to ensure that
153 * there will be no extra IRQ.
154 */
155 readw(ecc->regs + ecc->caps->ecc_regs[ECC_DECIRQ_STA]);
156 ecc->sectors = 0;
157 complete(&ecc->done);
158 } else {
159 return IRQ_HANDLED;
160 }
161 } else {
162 enc = readl(ecc->regs + ecc->caps->ecc_regs[ECC_ENCIRQ_STA])
163 & ECC_IRQ_EN;
164 if (enc)
165 complete(&ecc->done);
166 else
167 return IRQ_NONE;
168 }
169
170 return IRQ_HANDLED;
171 }
172
mtk_ecc_config(struct mtk_ecc * ecc,struct mtk_ecc_config * config)173 static int mtk_ecc_config(struct mtk_ecc *ecc, struct mtk_ecc_config *config)
174 {
175 u32 ecc_bit, dec_sz, enc_sz;
176 u32 reg, i;
177
178 for (i = 0; i < ecc->caps->num_ecc_strength; i++) {
179 if (ecc->caps->ecc_strength[i] == config->strength)
180 break;
181 }
182
183 if (i == ecc->caps->num_ecc_strength) {
184 dev_err(ecc->dev, "invalid ecc strength %d\n",
185 config->strength);
186 return -EINVAL;
187 }
188
189 ecc_bit = i;
190
191 if (config->op == ECC_ENCODE) {
192 /* configure ECC encoder (in bits) */
193 enc_sz = config->len << 3;
194
195 reg = ecc_bit | (config->mode << ecc->caps->ecc_mode_shift);
196 reg |= (enc_sz << ECC_MS_SHIFT);
197 writel(reg, ecc->regs + ECC_ENCCNFG);
198
199 if (config->mode != ECC_NFI_MODE)
200 writel(lower_32_bits(config->addr),
201 ecc->regs + ECC_ENCDIADDR);
202
203 } else {
204 /* configure ECC decoder (in bits) */
205 dec_sz = (config->len << 3) +
206 config->strength * ecc->caps->parity_bits;
207
208 reg = ecc_bit | (config->mode << ecc->caps->ecc_mode_shift);
209 reg |= (dec_sz << ECC_MS_SHIFT) | DEC_CNFG_CORRECT;
210 reg |= DEC_EMPTY_EN;
211 writel(reg, ecc->regs + ECC_DECCNFG);
212
213 if (config->sectors)
214 ecc->sectors = 1 << (config->sectors - 1);
215 }
216
217 return 0;
218 }
219
mtk_ecc_get_stats(struct mtk_ecc * ecc,struct mtk_ecc_stats * stats,int sectors)220 void mtk_ecc_get_stats(struct mtk_ecc *ecc, struct mtk_ecc_stats *stats,
221 int sectors)
222 {
223 u32 offset, i, err;
224 u32 bitflips = 0;
225
226 stats->corrected = 0;
227 stats->failed = 0;
228
229 for (i = 0; i < sectors; i++) {
230 offset = (i >> 2) << 2;
231 err = readl(ecc->regs + ECC_DECENUM0 + offset);
232 err = err >> ((i % 4) * ecc->caps->err_shift);
233 err &= ecc->caps->err_mask;
234 if (err == ecc->caps->err_mask) {
235 /* uncorrectable errors */
236 stats->failed++;
237 continue;
238 }
239
240 stats->corrected += err;
241 bitflips = max_t(u32, bitflips, err);
242 }
243
244 stats->bitflips = bitflips;
245 }
246 EXPORT_SYMBOL(mtk_ecc_get_stats);
247
mtk_ecc_release(struct mtk_ecc * ecc)248 void mtk_ecc_release(struct mtk_ecc *ecc)
249 {
250 clk_disable_unprepare(ecc->clk);
251 put_device(ecc->dev);
252 }
253 EXPORT_SYMBOL(mtk_ecc_release);
254
mtk_ecc_hw_init(struct mtk_ecc * ecc)255 static void mtk_ecc_hw_init(struct mtk_ecc *ecc)
256 {
257 mtk_ecc_wait_idle(ecc, ECC_ENCODE);
258 writew(ECC_OP_DISABLE, ecc->regs + ECC_ENCCON);
259
260 mtk_ecc_wait_idle(ecc, ECC_DECODE);
261 writel(ECC_OP_DISABLE, ecc->regs + ECC_DECCON);
262 }
263
mtk_ecc_get(struct device_node * np)264 static struct mtk_ecc *mtk_ecc_get(struct device_node *np)
265 {
266 struct platform_device *pdev;
267 struct mtk_ecc *ecc;
268
269 pdev = of_find_device_by_node(np);
270 if (!pdev)
271 return ERR_PTR(-EPROBE_DEFER);
272
273 ecc = platform_get_drvdata(pdev);
274 if (!ecc) {
275 put_device(&pdev->dev);
276 return ERR_PTR(-EPROBE_DEFER);
277 }
278
279 clk_prepare_enable(ecc->clk);
280 mtk_ecc_hw_init(ecc);
281
282 return ecc;
283 }
284
of_mtk_ecc_get(struct device_node * of_node)285 struct mtk_ecc *of_mtk_ecc_get(struct device_node *of_node)
286 {
287 struct mtk_ecc *ecc = NULL;
288 struct device_node *np;
289
290 np = of_parse_phandle(of_node, "nand-ecc-engine", 0);
291 /* for backward compatibility */
292 if (!np)
293 np = of_parse_phandle(of_node, "ecc-engine", 0);
294 if (np) {
295 ecc = mtk_ecc_get(np);
296 of_node_put(np);
297 }
298
299 return ecc;
300 }
301 EXPORT_SYMBOL(of_mtk_ecc_get);
302
mtk_ecc_enable(struct mtk_ecc * ecc,struct mtk_ecc_config * config)303 int mtk_ecc_enable(struct mtk_ecc *ecc, struct mtk_ecc_config *config)
304 {
305 enum mtk_ecc_operation op = config->op;
306 u16 reg_val;
307 int ret;
308
309 ret = mutex_lock_interruptible(&ecc->lock);
310 if (ret) {
311 dev_err(ecc->dev, "interrupted when attempting to lock\n");
312 return ret;
313 }
314
315 mtk_ecc_wait_idle(ecc, op);
316
317 ret = mtk_ecc_config(ecc, config);
318 if (ret) {
319 mutex_unlock(&ecc->lock);
320 return ret;
321 }
322
323 if (config->mode != ECC_NFI_MODE || op != ECC_ENCODE) {
324 init_completion(&ecc->done);
325 reg_val = ECC_IRQ_EN;
326 /*
327 * For ECC_NFI_MODE, if ecc->caps->pg_irq_sel is 1, then it
328 * means this chip can only generate one ecc irq during page
329 * read / write. If is 0, generate one ecc irq each ecc step.
330 */
331 if (ecc->caps->pg_irq_sel && config->mode == ECC_NFI_MODE)
332 reg_val |= ECC_PG_IRQ_SEL;
333 if (op == ECC_ENCODE)
334 writew(reg_val, ecc->regs +
335 ecc->caps->ecc_regs[ECC_ENCIRQ_EN]);
336 else
337 writew(reg_val, ecc->regs +
338 ecc->caps->ecc_regs[ECC_DECIRQ_EN]);
339 }
340
341 writew(ECC_OP_ENABLE, ecc->regs + ECC_CTL_REG(op));
342
343 return 0;
344 }
345 EXPORT_SYMBOL(mtk_ecc_enable);
346
mtk_ecc_disable(struct mtk_ecc * ecc)347 void mtk_ecc_disable(struct mtk_ecc *ecc)
348 {
349 enum mtk_ecc_operation op = ECC_ENCODE;
350
351 /* find out the running operation */
352 if (readw(ecc->regs + ECC_CTL_REG(op)) != ECC_OP_ENABLE)
353 op = ECC_DECODE;
354
355 /* disable it */
356 mtk_ecc_wait_idle(ecc, op);
357 if (op == ECC_DECODE) {
358 /*
359 * Clear decode IRQ status in case there is a timeout to wait
360 * decode IRQ.
361 */
362 readw(ecc->regs + ecc->caps->ecc_regs[ECC_DECDONE]);
363 writew(0, ecc->regs + ecc->caps->ecc_regs[ECC_DECIRQ_EN]);
364 } else {
365 writew(0, ecc->regs + ecc->caps->ecc_regs[ECC_ENCIRQ_EN]);
366 }
367
368 writew(ECC_OP_DISABLE, ecc->regs + ECC_CTL_REG(op));
369
370 mutex_unlock(&ecc->lock);
371 }
372 EXPORT_SYMBOL(mtk_ecc_disable);
373
mtk_ecc_wait_done(struct mtk_ecc * ecc,enum mtk_ecc_operation op)374 int mtk_ecc_wait_done(struct mtk_ecc *ecc, enum mtk_ecc_operation op)
375 {
376 int ret;
377
378 ret = wait_for_completion_timeout(&ecc->done, msecs_to_jiffies(500));
379 if (!ret) {
380 dev_err(ecc->dev, "%s timeout - interrupt did not arrive)\n",
381 (op == ECC_ENCODE) ? "encoder" : "decoder");
382 return -ETIMEDOUT;
383 }
384
385 return 0;
386 }
387 EXPORT_SYMBOL(mtk_ecc_wait_done);
388
mtk_ecc_encode(struct mtk_ecc * ecc,struct mtk_ecc_config * config,u8 * data,u32 bytes)389 int mtk_ecc_encode(struct mtk_ecc *ecc, struct mtk_ecc_config *config,
390 u8 *data, u32 bytes)
391 {
392 dma_addr_t addr;
393 u32 len;
394 int ret;
395
396 addr = dma_map_single(ecc->dev, data, bytes, DMA_TO_DEVICE);
397 ret = dma_mapping_error(ecc->dev, addr);
398 if (ret) {
399 dev_err(ecc->dev, "dma mapping error\n");
400 return -EINVAL;
401 }
402
403 config->op = ECC_ENCODE;
404 config->addr = addr;
405 ret = mtk_ecc_enable(ecc, config);
406 if (ret) {
407 dma_unmap_single(ecc->dev, addr, bytes, DMA_TO_DEVICE);
408 return ret;
409 }
410
411 ret = mtk_ecc_wait_done(ecc, ECC_ENCODE);
412 if (ret)
413 goto timeout;
414
415 mtk_ecc_wait_idle(ecc, ECC_ENCODE);
416
417 /* Program ECC bytes to OOB: per sector oob = FDM + ECC + SPARE */
418 len = (config->strength * ecc->caps->parity_bits + 7) >> 3;
419
420 /* write the parity bytes generated by the ECC back to temp buffer */
421 __ioread32_copy(ecc->eccdata,
422 ecc->regs + ecc->caps->ecc_regs[ECC_ENCPAR00],
423 round_up(len, 4));
424
425 /* copy into possibly unaligned OOB region with actual length */
426 memcpy(data + bytes, ecc->eccdata, len);
427 timeout:
428
429 dma_unmap_single(ecc->dev, addr, bytes, DMA_TO_DEVICE);
430 mtk_ecc_disable(ecc);
431
432 return ret;
433 }
434 EXPORT_SYMBOL(mtk_ecc_encode);
435
mtk_ecc_adjust_strength(struct mtk_ecc * ecc,u32 * p)436 void mtk_ecc_adjust_strength(struct mtk_ecc *ecc, u32 *p)
437 {
438 const u8 *ecc_strength = ecc->caps->ecc_strength;
439 int i;
440
441 for (i = 0; i < ecc->caps->num_ecc_strength; i++) {
442 if (*p <= ecc_strength[i]) {
443 if (!i)
444 *p = ecc_strength[i];
445 else if (*p != ecc_strength[i])
446 *p = ecc_strength[i - 1];
447 return;
448 }
449 }
450
451 *p = ecc_strength[ecc->caps->num_ecc_strength - 1];
452 }
453 EXPORT_SYMBOL(mtk_ecc_adjust_strength);
454
mtk_ecc_get_parity_bits(struct mtk_ecc * ecc)455 unsigned int mtk_ecc_get_parity_bits(struct mtk_ecc *ecc)
456 {
457 return ecc->caps->parity_bits;
458 }
459 EXPORT_SYMBOL(mtk_ecc_get_parity_bits);
460
461 static const struct mtk_ecc_caps mtk_ecc_caps_mt2701 = {
462 .err_mask = ECC_ERRMASK_MT2701,
463 .err_shift = 8,
464 .ecc_strength = ecc_strength_mt2701,
465 .ecc_regs = mt2701_ecc_regs,
466 .num_ecc_strength = 20,
467 .ecc_mode_shift = 5,
468 .parity_bits = 14,
469 .pg_irq_sel = 0,
470 };
471
472 static const struct mtk_ecc_caps mtk_ecc_caps_mt2712 = {
473 .err_mask = ECC_ERRMASK_MT2712,
474 .err_shift = 8,
475 .ecc_strength = ecc_strength_mt2712,
476 .ecc_regs = mt2712_ecc_regs,
477 .num_ecc_strength = 23,
478 .ecc_mode_shift = 5,
479 .parity_bits = 14,
480 .pg_irq_sel = 1,
481 };
482
483 static const struct mtk_ecc_caps mtk_ecc_caps_mt7622 = {
484 .err_mask = ECC_ERRMASK_MT7622,
485 .err_shift = 5,
486 .ecc_strength = ecc_strength_mt7622,
487 .ecc_regs = mt7622_ecc_regs,
488 .num_ecc_strength = 5,
489 .ecc_mode_shift = 4,
490 .parity_bits = 13,
491 .pg_irq_sel = 0,
492 };
493
494 static const struct mtk_ecc_caps mtk_ecc_caps_mt7986 = {
495 .err_mask = ECC_ERRMASK_MT7622,
496 .err_shift = 8,
497 .ecc_strength = ecc_strength_mt7986,
498 .ecc_regs = mt2712_ecc_regs,
499 .num_ecc_strength = 11,
500 .ecc_mode_shift = 5,
501 .parity_bits = 14,
502 .pg_irq_sel = 1,
503 };
504
505 static const struct of_device_id mtk_ecc_dt_match[] = {
506 {
507 .compatible = "mediatek,mt2701-ecc",
508 .data = &mtk_ecc_caps_mt2701,
509 }, {
510 .compatible = "mediatek,mt2712-ecc",
511 .data = &mtk_ecc_caps_mt2712,
512 }, {
513 .compatible = "mediatek,mt7622-ecc",
514 .data = &mtk_ecc_caps_mt7622,
515 }, {
516 .compatible = "mediatek,mt7986-ecc",
517 .data = &mtk_ecc_caps_mt7986,
518 },
519 {},
520 };
521
mtk_ecc_probe(struct platform_device * pdev)522 static int mtk_ecc_probe(struct platform_device *pdev)
523 {
524 struct device *dev = &pdev->dev;
525 struct mtk_ecc *ecc;
526 u32 max_eccdata_size;
527 int irq, ret;
528
529 ecc = devm_kzalloc(dev, sizeof(*ecc), GFP_KERNEL);
530 if (!ecc)
531 return -ENOMEM;
532
533 ecc->caps = of_device_get_match_data(dev);
534
535 max_eccdata_size = ecc->caps->num_ecc_strength - 1;
536 max_eccdata_size = ecc->caps->ecc_strength[max_eccdata_size];
537 max_eccdata_size = (max_eccdata_size * ecc->caps->parity_bits + 7) >> 3;
538 max_eccdata_size = round_up(max_eccdata_size, 4);
539 ecc->eccdata = devm_kzalloc(dev, max_eccdata_size, GFP_KERNEL);
540 if (!ecc->eccdata)
541 return -ENOMEM;
542
543 ecc->regs = devm_platform_ioremap_resource(pdev, 0);
544 if (IS_ERR(ecc->regs))
545 return PTR_ERR(ecc->regs);
546
547 ecc->clk = devm_clk_get(dev, NULL);
548 if (IS_ERR(ecc->clk)) {
549 dev_err(dev, "failed to get clock: %ld\n", PTR_ERR(ecc->clk));
550 return PTR_ERR(ecc->clk);
551 }
552
553 irq = platform_get_irq(pdev, 0);
554 if (irq < 0)
555 return irq;
556
557 ret = dma_set_mask(dev, DMA_BIT_MASK(32));
558 if (ret) {
559 dev_err(dev, "failed to set DMA mask\n");
560 return ret;
561 }
562
563 ret = devm_request_irq(dev, irq, mtk_ecc_irq, 0x0, "mtk-ecc", ecc);
564 if (ret) {
565 dev_err(dev, "failed to request irq\n");
566 return -EINVAL;
567 }
568
569 ecc->dev = dev;
570 mutex_init(&ecc->lock);
571 platform_set_drvdata(pdev, ecc);
572 dev_info(dev, "probed\n");
573
574 return 0;
575 }
576
577 #ifdef CONFIG_PM_SLEEP
mtk_ecc_suspend(struct device * dev)578 static int mtk_ecc_suspend(struct device *dev)
579 {
580 struct mtk_ecc *ecc = dev_get_drvdata(dev);
581
582 clk_disable_unprepare(ecc->clk);
583
584 return 0;
585 }
586
mtk_ecc_resume(struct device * dev)587 static int mtk_ecc_resume(struct device *dev)
588 {
589 struct mtk_ecc *ecc = dev_get_drvdata(dev);
590 int ret;
591
592 ret = clk_prepare_enable(ecc->clk);
593 if (ret) {
594 dev_err(dev, "failed to enable clk\n");
595 return ret;
596 }
597
598 return 0;
599 }
600
601 static SIMPLE_DEV_PM_OPS(mtk_ecc_pm_ops, mtk_ecc_suspend, mtk_ecc_resume);
602 #endif
603
604 MODULE_DEVICE_TABLE(of, mtk_ecc_dt_match);
605
606 static struct platform_driver mtk_ecc_driver = {
607 .probe = mtk_ecc_probe,
608 .driver = {
609 .name = "mtk-ecc",
610 .of_match_table = mtk_ecc_dt_match,
611 #ifdef CONFIG_PM_SLEEP
612 .pm = &mtk_ecc_pm_ops,
613 #endif
614 },
615 };
616
617 module_platform_driver(mtk_ecc_driver);
618
619 MODULE_AUTHOR("Xiaolei Li <xiaolei.li@mediatek.com>");
620 MODULE_DESCRIPTION("MTK Nand ECC Driver");
621 MODULE_LICENSE("Dual MIT/GPL");
622