linux/drivers/mtd/nand/raw/mtk_ecc.c
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   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
  19#include "mtk_ecc.h"
  20
  21#define ECC_IDLE_MASK           BIT(0)
  22#define ECC_IRQ_EN              BIT(0)
  23#define ECC_PG_IRQ_SEL          BIT(1)
  24#define ECC_OP_ENABLE           (1)
  25#define ECC_OP_DISABLE          (0)
  26
  27#define ECC_ENCCON              (0x00)
  28#define ECC_ENCCNFG             (0x04)
  29#define         ECC_MS_SHIFT            (16)
  30#define ECC_ENCDIADDR           (0x08)
  31#define ECC_ENCIDLE             (0x0C)
  32#define ECC_DECCON              (0x100)
  33#define ECC_DECCNFG             (0x104)
  34#define         DEC_EMPTY_EN            BIT(31)
  35#define         DEC_CNFG_CORRECT        (0x3 << 12)
  36#define ECC_DECIDLE             (0x10C)
  37#define ECC_DECENUM0            (0x114)
  38
  39#define ECC_TIMEOUT             (500000)
  40
  41#define ECC_IDLE_REG(op)        ((op) == ECC_ENCODE ? ECC_ENCIDLE : ECC_DECIDLE)
  42#define ECC_CTL_REG(op)         ((op) == ECC_ENCODE ? ECC_ENCCON : ECC_DECCON)
  43
  44struct mtk_ecc_caps {
  45        u32 err_mask;
  46        const u8 *ecc_strength;
  47        const u32 *ecc_regs;
  48        u8 num_ecc_strength;
  49        u8 ecc_mode_shift;
  50        u32 parity_bits;
  51        int pg_irq_sel;
  52};
  53
  54struct mtk_ecc {
  55        struct device *dev;
  56        const struct mtk_ecc_caps *caps;
  57        void __iomem *regs;
  58        struct clk *clk;
  59
  60        struct completion done;
  61        struct mutex lock;
  62        u32 sectors;
  63
  64        u8 *eccdata;
  65};
  66
  67/* ecc strength that each IP supports */
  68static const u8 ecc_strength_mt2701[] = {
  69        4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 28, 32, 36,
  70        40, 44, 48, 52, 56, 60
  71};
  72
  73static const u8 ecc_strength_mt2712[] = {
  74        4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 28, 32, 36,
  75        40, 44, 48, 52, 56, 60, 68, 72, 80
  76};
  77
  78static const u8 ecc_strength_mt7622[] = {
  79        4, 6, 8, 10, 12, 14, 16
  80};
  81
  82enum mtk_ecc_regs {
  83        ECC_ENCPAR00,
  84        ECC_ENCIRQ_EN,
  85        ECC_ENCIRQ_STA,
  86        ECC_DECDONE,
  87        ECC_DECIRQ_EN,
  88        ECC_DECIRQ_STA,
  89};
  90
  91static int mt2701_ecc_regs[] = {
  92        [ECC_ENCPAR00] =        0x10,
  93        [ECC_ENCIRQ_EN] =       0x80,
  94        [ECC_ENCIRQ_STA] =      0x84,
  95        [ECC_DECDONE] =         0x124,
  96        [ECC_DECIRQ_EN] =       0x200,
  97        [ECC_DECIRQ_STA] =      0x204,
  98};
  99
 100static int mt2712_ecc_regs[] = {
 101        [ECC_ENCPAR00] =        0x300,
 102        [ECC_ENCIRQ_EN] =       0x80,
 103        [ECC_ENCIRQ_STA] =      0x84,
 104        [ECC_DECDONE] =         0x124,
 105        [ECC_DECIRQ_EN] =       0x200,
 106        [ECC_DECIRQ_STA] =      0x204,
 107};
 108
 109static int mt7622_ecc_regs[] = {
 110        [ECC_ENCPAR00] =        0x10,
 111        [ECC_ENCIRQ_EN] =       0x30,
 112        [ECC_ENCIRQ_STA] =      0x34,
 113        [ECC_DECDONE] =         0x11c,
 114        [ECC_DECIRQ_EN] =       0x140,
 115        [ECC_DECIRQ_STA] =      0x144,
 116};
 117
 118static inline void mtk_ecc_wait_idle(struct mtk_ecc *ecc,
 119                                     enum mtk_ecc_operation op)
 120{
 121        struct device *dev = ecc->dev;
 122        u32 val;
 123        int ret;
 124
 125        ret = readl_poll_timeout_atomic(ecc->regs + ECC_IDLE_REG(op), val,
 126                                        val & ECC_IDLE_MASK,
 127                                        10, ECC_TIMEOUT);
 128        if (ret)
 129                dev_warn(dev, "%s NOT idle\n",
 130                         op == ECC_ENCODE ? "encoder" : "decoder");
 131}
 132
 133static irqreturn_t mtk_ecc_irq(int irq, void *id)
 134{
 135        struct mtk_ecc *ecc = id;
 136        u32 dec, enc;
 137
 138        dec = readw(ecc->regs + ecc->caps->ecc_regs[ECC_DECIRQ_STA])
 139                    & ECC_IRQ_EN;
 140        if (dec) {
 141                dec = readw(ecc->regs + ecc->caps->ecc_regs[ECC_DECDONE]);
 142                if (dec & ecc->sectors) {
 143                        /*
 144                         * Clear decode IRQ status once again to ensure that
 145                         * there will be no extra IRQ.
 146                         */
 147                        readw(ecc->regs + ecc->caps->ecc_regs[ECC_DECIRQ_STA]);
 148                        ecc->sectors = 0;
 149                        complete(&ecc->done);
 150                } else {
 151                        return IRQ_HANDLED;
 152                }
 153        } else {
 154                enc = readl(ecc->regs + ecc->caps->ecc_regs[ECC_ENCIRQ_STA])
 155                      & ECC_IRQ_EN;
 156                if (enc)
 157                        complete(&ecc->done);
 158                else
 159                        return IRQ_NONE;
 160        }
 161
 162        return IRQ_HANDLED;
 163}
 164
 165static int mtk_ecc_config(struct mtk_ecc *ecc, struct mtk_ecc_config *config)
 166{
 167        u32 ecc_bit, dec_sz, enc_sz;
 168        u32 reg, i;
 169
 170        for (i = 0; i < ecc->caps->num_ecc_strength; i++) {
 171                if (ecc->caps->ecc_strength[i] == config->strength)
 172                        break;
 173        }
 174
 175        if (i == ecc->caps->num_ecc_strength) {
 176                dev_err(ecc->dev, "invalid ecc strength %d\n",
 177                        config->strength);
 178                return -EINVAL;
 179        }
 180
 181        ecc_bit = i;
 182
 183        if (config->op == ECC_ENCODE) {
 184                /* configure ECC encoder (in bits) */
 185                enc_sz = config->len << 3;
 186
 187                reg = ecc_bit | (config->mode << ecc->caps->ecc_mode_shift);
 188                reg |= (enc_sz << ECC_MS_SHIFT);
 189                writel(reg, ecc->regs + ECC_ENCCNFG);
 190
 191                if (config->mode != ECC_NFI_MODE)
 192                        writel(lower_32_bits(config->addr),
 193                               ecc->regs + ECC_ENCDIADDR);
 194
 195        } else {
 196                /* configure ECC decoder (in bits) */
 197                dec_sz = (config->len << 3) +
 198                         config->strength * ecc->caps->parity_bits;
 199
 200                reg = ecc_bit | (config->mode << ecc->caps->ecc_mode_shift);
 201                reg |= (dec_sz << ECC_MS_SHIFT) | DEC_CNFG_CORRECT;
 202                reg |= DEC_EMPTY_EN;
 203                writel(reg, ecc->regs + ECC_DECCNFG);
 204
 205                if (config->sectors)
 206                        ecc->sectors = 1 << (config->sectors - 1);
 207        }
 208
 209        return 0;
 210}
 211
 212void mtk_ecc_get_stats(struct mtk_ecc *ecc, struct mtk_ecc_stats *stats,
 213                       int sectors)
 214{
 215        u32 offset, i, err;
 216        u32 bitflips = 0;
 217
 218        stats->corrected = 0;
 219        stats->failed = 0;
 220
 221        for (i = 0; i < sectors; i++) {
 222                offset = (i >> 2) << 2;
 223                err = readl(ecc->regs + ECC_DECENUM0 + offset);
 224                err = err >> ((i % 4) * 8);
 225                err &= ecc->caps->err_mask;
 226                if (err == ecc->caps->err_mask) {
 227                        /* uncorrectable errors */
 228                        stats->failed++;
 229                        continue;
 230                }
 231
 232                stats->corrected += err;
 233                bitflips = max_t(u32, bitflips, err);
 234        }
 235
 236        stats->bitflips = bitflips;
 237}
 238EXPORT_SYMBOL(mtk_ecc_get_stats);
 239
 240void mtk_ecc_release(struct mtk_ecc *ecc)
 241{
 242        clk_disable_unprepare(ecc->clk);
 243        put_device(ecc->dev);
 244}
 245EXPORT_SYMBOL(mtk_ecc_release);
 246
 247static void mtk_ecc_hw_init(struct mtk_ecc *ecc)
 248{
 249        mtk_ecc_wait_idle(ecc, ECC_ENCODE);
 250        writew(ECC_OP_DISABLE, ecc->regs + ECC_ENCCON);
 251
 252        mtk_ecc_wait_idle(ecc, ECC_DECODE);
 253        writel(ECC_OP_DISABLE, ecc->regs + ECC_DECCON);
 254}
 255
 256static struct mtk_ecc *mtk_ecc_get(struct device_node *np)
 257{
 258        struct platform_device *pdev;
 259        struct mtk_ecc *ecc;
 260
 261        pdev = of_find_device_by_node(np);
 262        if (!pdev)
 263                return ERR_PTR(-EPROBE_DEFER);
 264
 265        ecc = platform_get_drvdata(pdev);
 266        if (!ecc) {
 267                put_device(&pdev->dev);
 268                return ERR_PTR(-EPROBE_DEFER);
 269        }
 270
 271        clk_prepare_enable(ecc->clk);
 272        mtk_ecc_hw_init(ecc);
 273
 274        return ecc;
 275}
 276
 277struct mtk_ecc *of_mtk_ecc_get(struct device_node *of_node)
 278{
 279        struct mtk_ecc *ecc = NULL;
 280        struct device_node *np;
 281
 282        np = of_parse_phandle(of_node, "ecc-engine", 0);
 283        if (np) {
 284                ecc = mtk_ecc_get(np);
 285                of_node_put(np);
 286        }
 287
 288        return ecc;
 289}
 290EXPORT_SYMBOL(of_mtk_ecc_get);
 291
 292int mtk_ecc_enable(struct mtk_ecc *ecc, struct mtk_ecc_config *config)
 293{
 294        enum mtk_ecc_operation op = config->op;
 295        u16 reg_val;
 296        int ret;
 297
 298        ret = mutex_lock_interruptible(&ecc->lock);
 299        if (ret) {
 300                dev_err(ecc->dev, "interrupted when attempting to lock\n");
 301                return ret;
 302        }
 303
 304        mtk_ecc_wait_idle(ecc, op);
 305
 306        ret = mtk_ecc_config(ecc, config);
 307        if (ret) {
 308                mutex_unlock(&ecc->lock);
 309                return ret;
 310        }
 311
 312        if (config->mode != ECC_NFI_MODE || op != ECC_ENCODE) {
 313                init_completion(&ecc->done);
 314                reg_val = ECC_IRQ_EN;
 315                /*
 316                 * For ECC_NFI_MODE, if ecc->caps->pg_irq_sel is 1, then it
 317                 * means this chip can only generate one ecc irq during page
 318                 * read / write. If is 0, generate one ecc irq each ecc step.
 319                 */
 320                if (ecc->caps->pg_irq_sel && config->mode == ECC_NFI_MODE)
 321                        reg_val |= ECC_PG_IRQ_SEL;
 322                if (op == ECC_ENCODE)
 323                        writew(reg_val, ecc->regs +
 324                               ecc->caps->ecc_regs[ECC_ENCIRQ_EN]);
 325                else
 326                        writew(reg_val, ecc->regs +
 327                               ecc->caps->ecc_regs[ECC_DECIRQ_EN]);
 328        }
 329
 330        writew(ECC_OP_ENABLE, ecc->regs + ECC_CTL_REG(op));
 331
 332        return 0;
 333}
 334EXPORT_SYMBOL(mtk_ecc_enable);
 335
 336void mtk_ecc_disable(struct mtk_ecc *ecc)
 337{
 338        enum mtk_ecc_operation op = ECC_ENCODE;
 339
 340        /* find out the running operation */
 341        if (readw(ecc->regs + ECC_CTL_REG(op)) != ECC_OP_ENABLE)
 342                op = ECC_DECODE;
 343
 344        /* disable it */
 345        mtk_ecc_wait_idle(ecc, op);
 346        if (op == ECC_DECODE) {
 347                /*
 348                 * Clear decode IRQ status in case there is a timeout to wait
 349                 * decode IRQ.
 350                 */
 351                readw(ecc->regs + ecc->caps->ecc_regs[ECC_DECDONE]);
 352                writew(0, ecc->regs + ecc->caps->ecc_regs[ECC_DECIRQ_EN]);
 353        } else {
 354                writew(0, ecc->regs + ecc->caps->ecc_regs[ECC_ENCIRQ_EN]);
 355        }
 356
 357        writew(ECC_OP_DISABLE, ecc->regs + ECC_CTL_REG(op));
 358
 359        mutex_unlock(&ecc->lock);
 360}
 361EXPORT_SYMBOL(mtk_ecc_disable);
 362
 363int mtk_ecc_wait_done(struct mtk_ecc *ecc, enum mtk_ecc_operation op)
 364{
 365        int ret;
 366
 367        ret = wait_for_completion_timeout(&ecc->done, msecs_to_jiffies(500));
 368        if (!ret) {
 369                dev_err(ecc->dev, "%s timeout - interrupt did not arrive)\n",
 370                        (op == ECC_ENCODE) ? "encoder" : "decoder");
 371                return -ETIMEDOUT;
 372        }
 373
 374        return 0;
 375}
 376EXPORT_SYMBOL(mtk_ecc_wait_done);
 377
 378int mtk_ecc_encode(struct mtk_ecc *ecc, struct mtk_ecc_config *config,
 379                   u8 *data, u32 bytes)
 380{
 381        dma_addr_t addr;
 382        u32 len;
 383        int ret;
 384
 385        addr = dma_map_single(ecc->dev, data, bytes, DMA_TO_DEVICE);
 386        ret = dma_mapping_error(ecc->dev, addr);
 387        if (ret) {
 388                dev_err(ecc->dev, "dma mapping error\n");
 389                return -EINVAL;
 390        }
 391
 392        config->op = ECC_ENCODE;
 393        config->addr = addr;
 394        ret = mtk_ecc_enable(ecc, config);
 395        if (ret) {
 396                dma_unmap_single(ecc->dev, addr, bytes, DMA_TO_DEVICE);
 397                return ret;
 398        }
 399
 400        ret = mtk_ecc_wait_done(ecc, ECC_ENCODE);
 401        if (ret)
 402                goto timeout;
 403
 404        mtk_ecc_wait_idle(ecc, ECC_ENCODE);
 405
 406        /* Program ECC bytes to OOB: per sector oob = FDM + ECC + SPARE */
 407        len = (config->strength * ecc->caps->parity_bits + 7) >> 3;
 408
 409        /* write the parity bytes generated by the ECC back to temp buffer */
 410        __ioread32_copy(ecc->eccdata,
 411                        ecc->regs + ecc->caps->ecc_regs[ECC_ENCPAR00],
 412                        round_up(len, 4));
 413
 414        /* copy into possibly unaligned OOB region with actual length */
 415        memcpy(data + bytes, ecc->eccdata, len);
 416timeout:
 417
 418        dma_unmap_single(ecc->dev, addr, bytes, DMA_TO_DEVICE);
 419        mtk_ecc_disable(ecc);
 420
 421        return ret;
 422}
 423EXPORT_SYMBOL(mtk_ecc_encode);
 424
 425void mtk_ecc_adjust_strength(struct mtk_ecc *ecc, u32 *p)
 426{
 427        const u8 *ecc_strength = ecc->caps->ecc_strength;
 428        int i;
 429
 430        for (i = 0; i < ecc->caps->num_ecc_strength; i++) {
 431                if (*p <= ecc_strength[i]) {
 432                        if (!i)
 433                                *p = ecc_strength[i];
 434                        else if (*p != ecc_strength[i])
 435                                *p = ecc_strength[i - 1];
 436                        return;
 437                }
 438        }
 439
 440        *p = ecc_strength[ecc->caps->num_ecc_strength - 1];
 441}
 442EXPORT_SYMBOL(mtk_ecc_adjust_strength);
 443
 444unsigned int mtk_ecc_get_parity_bits(struct mtk_ecc *ecc)
 445{
 446        return ecc->caps->parity_bits;
 447}
 448EXPORT_SYMBOL(mtk_ecc_get_parity_bits);
 449
 450static const struct mtk_ecc_caps mtk_ecc_caps_mt2701 = {
 451        .err_mask = 0x3f,
 452        .ecc_strength = ecc_strength_mt2701,
 453        .ecc_regs = mt2701_ecc_regs,
 454        .num_ecc_strength = 20,
 455        .ecc_mode_shift = 5,
 456        .parity_bits = 14,
 457        .pg_irq_sel = 0,
 458};
 459
 460static const struct mtk_ecc_caps mtk_ecc_caps_mt2712 = {
 461        .err_mask = 0x7f,
 462        .ecc_strength = ecc_strength_mt2712,
 463        .ecc_regs = mt2712_ecc_regs,
 464        .num_ecc_strength = 23,
 465        .ecc_mode_shift = 5,
 466        .parity_bits = 14,
 467        .pg_irq_sel = 1,
 468};
 469
 470static const struct mtk_ecc_caps mtk_ecc_caps_mt7622 = {
 471        .err_mask = 0x3f,
 472        .ecc_strength = ecc_strength_mt7622,
 473        .ecc_regs = mt7622_ecc_regs,
 474        .num_ecc_strength = 7,
 475        .ecc_mode_shift = 4,
 476        .parity_bits = 13,
 477        .pg_irq_sel = 0,
 478};
 479
 480static const struct of_device_id mtk_ecc_dt_match[] = {
 481        {
 482                .compatible = "mediatek,mt2701-ecc",
 483                .data = &mtk_ecc_caps_mt2701,
 484        }, {
 485                .compatible = "mediatek,mt2712-ecc",
 486                .data = &mtk_ecc_caps_mt2712,
 487        }, {
 488                .compatible = "mediatek,mt7622-ecc",
 489                .data = &mtk_ecc_caps_mt7622,
 490        },
 491        {},
 492};
 493
 494static int mtk_ecc_probe(struct platform_device *pdev)
 495{
 496        struct device *dev = &pdev->dev;
 497        struct mtk_ecc *ecc;
 498        struct resource *res;
 499        u32 max_eccdata_size;
 500        int irq, ret;
 501
 502        ecc = devm_kzalloc(dev, sizeof(*ecc), GFP_KERNEL);
 503        if (!ecc)
 504                return -ENOMEM;
 505
 506        ecc->caps = of_device_get_match_data(dev);
 507
 508        max_eccdata_size = ecc->caps->num_ecc_strength - 1;
 509        max_eccdata_size = ecc->caps->ecc_strength[max_eccdata_size];
 510        max_eccdata_size = (max_eccdata_size * ecc->caps->parity_bits + 7) >> 3;
 511        max_eccdata_size = round_up(max_eccdata_size, 4);
 512        ecc->eccdata = devm_kzalloc(dev, max_eccdata_size, GFP_KERNEL);
 513        if (!ecc->eccdata)
 514                return -ENOMEM;
 515
 516        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 517        ecc->regs = devm_ioremap_resource(dev, res);
 518        if (IS_ERR(ecc->regs))
 519                return PTR_ERR(ecc->regs);
 520
 521        ecc->clk = devm_clk_get(dev, NULL);
 522        if (IS_ERR(ecc->clk)) {
 523                dev_err(dev, "failed to get clock: %ld\n", PTR_ERR(ecc->clk));
 524                return PTR_ERR(ecc->clk);
 525        }
 526
 527        irq = platform_get_irq(pdev, 0);
 528        if (irq < 0)
 529                return irq;
 530
 531        ret = dma_set_mask(dev, DMA_BIT_MASK(32));
 532        if (ret) {
 533                dev_err(dev, "failed to set DMA mask\n");
 534                return ret;
 535        }
 536
 537        ret = devm_request_irq(dev, irq, mtk_ecc_irq, 0x0, "mtk-ecc", ecc);
 538        if (ret) {
 539                dev_err(dev, "failed to request irq\n");
 540                return -EINVAL;
 541        }
 542
 543        ecc->dev = dev;
 544        mutex_init(&ecc->lock);
 545        platform_set_drvdata(pdev, ecc);
 546        dev_info(dev, "probed\n");
 547
 548        return 0;
 549}
 550
 551#ifdef CONFIG_PM_SLEEP
 552static int mtk_ecc_suspend(struct device *dev)
 553{
 554        struct mtk_ecc *ecc = dev_get_drvdata(dev);
 555
 556        clk_disable_unprepare(ecc->clk);
 557
 558        return 0;
 559}
 560
 561static int mtk_ecc_resume(struct device *dev)
 562{
 563        struct mtk_ecc *ecc = dev_get_drvdata(dev);
 564        int ret;
 565
 566        ret = clk_prepare_enable(ecc->clk);
 567        if (ret) {
 568                dev_err(dev, "failed to enable clk\n");
 569                return ret;
 570        }
 571
 572        return 0;
 573}
 574
 575static SIMPLE_DEV_PM_OPS(mtk_ecc_pm_ops, mtk_ecc_suspend, mtk_ecc_resume);
 576#endif
 577
 578MODULE_DEVICE_TABLE(of, mtk_ecc_dt_match);
 579
 580static struct platform_driver mtk_ecc_driver = {
 581        .probe  = mtk_ecc_probe,
 582        .driver = {
 583                .name  = "mtk-ecc",
 584                .of_match_table = of_match_ptr(mtk_ecc_dt_match),
 585#ifdef CONFIG_PM_SLEEP
 586                .pm = &mtk_ecc_pm_ops,
 587#endif
 588        },
 589};
 590
 591module_platform_driver(mtk_ecc_driver);
 592
 593MODULE_AUTHOR("Xiaolei Li <xiaolei.li@mediatek.com>");
 594MODULE_DESCRIPTION("MTK Nand ECC Driver");
 595MODULE_LICENSE("Dual MIT/GPL");
 596