drivers/mtd/spi-nor/intel-spi.c

   1 /*
   2  * Intel PCH/PCU SPI flash driver.
   3  *
   4  * Copyright (C) 2016, Intel Corporation
   5  * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/err.h>
  13 #include <linux/io.h>
  14 #include <linux/iopoll.h>
  15 #include <linux/module.h>
  16 #include <linux/sched.h>
  17 #include <linux/sizes.h>
  18 #include <linux/mtd/mtd.h>
  19 #include <linux/mtd/partitions.h>
  20 #include <linux/mtd/spi-nor.h>
  21 #include <linux/platform_data/intel-spi.h>
  22
  23 #include "intel-spi.h"
  24
  25 /* Offsets are from @ispi->base */
  26 #define BFPREG                          0x00
  27
  28 #define HSFSTS_CTL                      0x04
  29 #define HSFSTS_CTL_FSMIE                BIT(31)
  30 #define HSFSTS_CTL_FDBC_SHIFT           24
  31 #define HSFSTS_CTL_FDBC_MASK            (0x3f << HSFSTS_CTL_FDBC_SHIFT)
  32
  33 #define HSFSTS_CTL_FCYCLE_SHIFT         17
  34 #define HSFSTS_CTL_FCYCLE_MASK          (0x0f << HSFSTS_CTL_FCYCLE_SHIFT)
  35 /* HW sequencer opcodes */
  36 #define HSFSTS_CTL_FCYCLE_READ          (0x00 << HSFSTS_CTL_FCYCLE_SHIFT)
  37 #define HSFSTS_CTL_FCYCLE_WRITE         (0x02 << HSFSTS_CTL_FCYCLE_SHIFT)
  38 #define HSFSTS_CTL_FCYCLE_ERASE         (0x03 << HSFSTS_CTL_FCYCLE_SHIFT)
  39 #define HSFSTS_CTL_FCYCLE_ERASE_64K     (0x04 << HSFSTS_CTL_FCYCLE_SHIFT)
  40 #define HSFSTS_CTL_FCYCLE_RDID          (0x06 << HSFSTS_CTL_FCYCLE_SHIFT)
  41 #define HSFSTS_CTL_FCYCLE_WRSR          (0x07 << HSFSTS_CTL_FCYCLE_SHIFT)
  42 #define HSFSTS_CTL_FCYCLE_RDSR          (0x08 << HSFSTS_CTL_FCYCLE_SHIFT)
  43
  44 #define HSFSTS_CTL_FGO                  BIT(16)
  45 #define HSFSTS_CTL_FLOCKDN              BIT(15)
  46 #define HSFSTS_CTL_FDV                  BIT(14)
  47 #define HSFSTS_CTL_SCIP                 BIT(5)
  48 #define HSFSTS_CTL_AEL                  BIT(2)
  49 #define HSFSTS_CTL_FCERR                BIT(1)
  50 #define HSFSTS_CTL_FDONE                BIT(0)
  51
  52 #define FADDR                           0x08
  53 #define DLOCK                           0x0c
  54 #define FDATA(n)                        (0x10 + ((n) * 4))
  55
  56 #define FRACC                           0x50
  57
  58 #define FREG(n)                         (0x54 + ((n) * 4))
  59 #define FREG_BASE_MASK                  0x3fff
  60 #define FREG_LIMIT_SHIFT                16
  61 #define FREG_LIMIT_MASK                 (0x03fff << FREG_LIMIT_SHIFT)
  62
  63 /* Offset is from @ispi->pregs */
  64 #define PR(n)                           ((n) * 4)
  65 #define PR_WPE                          BIT(31)
  66 #define PR_LIMIT_SHIFT                  16
  67 #define PR_LIMIT_MASK                   (0x3fff << PR_LIMIT_SHIFT)
  68 #define PR_RPE                          BIT(15)
  69 #define PR_BASE_MASK                    0x3fff
  70
  71 /* Offsets are from @ispi->sregs */
  72 #define SSFSTS_CTL                      0x00
  73 #define SSFSTS_CTL_FSMIE                BIT(23)
  74 #define SSFSTS_CTL_DS                   BIT(22)
  75 #define SSFSTS_CTL_DBC_SHIFT            16
  76 #define SSFSTS_CTL_SPOP                 BIT(11)
  77 #define SSFSTS_CTL_ACS                  BIT(10)
  78 #define SSFSTS_CTL_SCGO                 BIT(9)
  79 #define SSFSTS_CTL_COP_SHIFT            12
  80 #define SSFSTS_CTL_FRS                  BIT(7)
  81 #define SSFSTS_CTL_DOFRS                BIT(6)
  82 #define SSFSTS_CTL_AEL                  BIT(4)
  83 #define SSFSTS_CTL_FCERR                BIT(3)
  84 #define SSFSTS_CTL_FDONE                BIT(2)
  85 #define SSFSTS_CTL_SCIP                 BIT(0)
  86
  87 #define PREOP_OPTYPE                    0x04
  88 #define OPMENU0                         0x08
  89 #define OPMENU1                         0x0c
  90
  91 #define OPTYPE_READ_NO_ADDR             0
  92 #define OPTYPE_WRITE_NO_ADDR            1
  93 #define OPTYPE_READ_WITH_ADDR           2
  94 #define OPTYPE_WRITE_WITH_ADDR          3
  95
  96 /* CPU specifics */
  97 #define BYT_PR                          0x74
  98 #define BYT_SSFSTS_CTL                  0x90
  99 #define BYT_BCR                         0xfc
 100 #define BYT_BCR_WPD                     BIT(0)
 101 #define BYT_FREG_NUM                    5
 102 #define BYT_PR_NUM                      5
 103
 104 #define LPT_PR                          0x74
 105 #define LPT_SSFSTS_CTL                  0x90
 106 #define LPT_FREG_NUM                    5
 107 #define LPT_PR_NUM                      5
 108
 109 #define BXT_PR                          0x84
 110 #define BXT_SSFSTS_CTL                  0xa0
 111 #define BXT_FREG_NUM                    12
 112 #define BXT_PR_NUM                      6
 113
 114 #define LVSCC                           0xc4
 115 #define UVSCC                           0xc8
 116 #define ERASE_OPCODE_SHIFT              8
 117 #define ERASE_OPCODE_MASK               (0xff << ERASE_OPCODE_SHIFT)
 118 #define ERASE_64K_OPCODE_SHIFT          16
 119 #define ERASE_64K_OPCODE_MASK           (0xff << ERASE_OPCODE_SHIFT)
 120
 121 #define INTEL_SPI_TIMEOUT               5000 /* ms */
 122 #define INTEL_SPI_FIFO_SZ               64
 123
 124 /**
 125  * struct intel_spi - Driver private data
 126  * @dev: Device pointer
 127  * @info: Pointer to board specific info
 128  * @nor: SPI NOR layer structure
 129  * @base: Beginning of MMIO space
 130  * @pregs: Start of protection registers
 131  * @sregs: Start of software sequencer registers
 132  * @nregions: Maximum number of regions
 133  * @pr_num: Maximum number of protected range registers
 134  * @writeable: Is the chip writeable
 135  * @locked: Is SPI setting locked
 136  * @swseq_reg: Use SW sequencer in register reads/writes
 137  * @swseq_erase: Use SW sequencer in erase operation
 138  * @erase_64k: 64k erase supported
 139  * @opcodes: Opcodes which are supported. This are programmed by BIOS
 140  *           before it locks down the controller.
 141  */
 142 struct intel_spi {
 143         struct device *dev;
 144         const struct intel_spi_boardinfo *info;
 145         struct spi_nor nor;
 146         void __iomem *base;
 147         void __iomem *pregs;
 148         void __iomem *sregs;
 149         size_t nregions;
 150         size_t pr_num;
 151         bool writeable;
 152         bool locked;
 153         bool swseq_reg;
 154         bool swseq_erase;
 155         bool erase_64k;
 156         u8 opcodes[8];
 157 };
 158
 159 static bool writeable;
 160 module_param(writeable, bool, 0);
 161 MODULE_PARM_DESC(writeable, "Enable write access to SPI flash chip (default=0)");
 162
 163 static void intel_spi_dump_regs(struct intel_spi *ispi)
 164 {
 165         u32 value;
 166         int i;
 167
 168         dev_dbg(ispi->dev, "BFPREG=0x%08x\n", readl(ispi->base + BFPREG));
 169
 170         value = readl(ispi->base + HSFSTS_CTL);
 171         dev_dbg(ispi->dev, "HSFSTS_CTL=0x%08x\n", value);
 172         if (value & HSFSTS_CTL_FLOCKDN)
 173                 dev_dbg(ispi->dev, "-> Locked\n");
 174
 175         dev_dbg(ispi->dev, "FADDR=0x%08x\n", readl(ispi->base + FADDR));
 176         dev_dbg(ispi->dev, "DLOCK=0x%08x\n", readl(ispi->base + DLOCK));
 177
 178         for (i = 0; i < 16; i++)
 179                 dev_dbg(ispi->dev, "FDATA(%d)=0x%08x\n",
 180                         i, readl(ispi->base + FDATA(i)));
 181
 182         dev_dbg(ispi->dev, "FRACC=0x%08x\n", readl(ispi->base + FRACC));
 183
 184         for (i = 0; i < ispi->nregions; i++)
 185                 dev_dbg(ispi->dev, "FREG(%d)=0x%08x\n", i,
 186                         readl(ispi->base + FREG(i)));
 187         for (i = 0; i < ispi->pr_num; i++)
 188                 dev_dbg(ispi->dev, "PR(%d)=0x%08x\n", i,
 189                         readl(ispi->pregs + PR(i)));
 190
 191         value = readl(ispi->sregs + SSFSTS_CTL);
 192         dev_dbg(ispi->dev, "SSFSTS_CTL=0x%08x\n", value);
 193         dev_dbg(ispi->dev, "PREOP_OPTYPE=0x%08x\n",
 194                 readl(ispi->sregs + PREOP_OPTYPE));
 195         dev_dbg(ispi->dev, "OPMENU0=0x%08x\n", readl(ispi->sregs + OPMENU0));
 196         dev_dbg(ispi->dev, "OPMENU1=0x%08x\n", readl(ispi->sregs + OPMENU1));
 197
 198         if (ispi->info->type == INTEL_SPI_BYT)
 199                 dev_dbg(ispi->dev, "BCR=0x%08x\n", readl(ispi->base + BYT_BCR));
 200
 201         dev_dbg(ispi->dev, "LVSCC=0x%08x\n", readl(ispi->base + LVSCC));
 202         dev_dbg(ispi->dev, "UVSCC=0x%08x\n", readl(ispi->base + UVSCC));
 203
 204         dev_dbg(ispi->dev, "Protected regions:\n");
 205         for (i = 0; i < ispi->pr_num; i++) {
 206                 u32 base, limit;
 207
 208                 value = readl(ispi->pregs + PR(i));
 209                 if (!(value & (PR_WPE | PR_RPE)))
 210                         continue;
 211
 212                 limit = (value & PR_LIMIT_MASK) >> PR_LIMIT_SHIFT;
 213                 base = value & PR_BASE_MASK;
 214
 215                 dev_dbg(ispi->dev, " %02d base: 0x%08x limit: 0x%08x [%c%c]\n",
 216                          i, base << 12, (limit << 12) | 0xfff,
 217                          value & PR_WPE ? 'W' : '.',
 218                          value & PR_RPE ? 'R' : '.');
 219         }
 220
 221         dev_dbg(ispi->dev, "Flash regions:\n");
 222         for (i = 0; i < ispi->nregions; i++) {
 223                 u32 region, base, limit;
 224
 225                 region = readl(ispi->base + FREG(i));
 226                 base = region & FREG_BASE_MASK;
 227                 limit = (region & FREG_LIMIT_MASK) >> FREG_LIMIT_SHIFT;
 228
 229                 if (base >= limit || (i > 0 && limit == 0))
 230                         dev_dbg(ispi->dev, " %02d disabled\n", i);
 231                 else
 232                         dev_dbg(ispi->dev, " %02d base: 0x%08x limit: 0x%08x\n",
 233                                  i, base << 12, (limit << 12) | 0xfff);
 234         }
 235
 236         dev_dbg(ispi->dev, "Using %cW sequencer for register access\n",
 237                 ispi->swseq_reg ? 'S' : 'H');
 238         dev_dbg(ispi->dev, "Using %cW sequencer for erase operation\n",
 239                 ispi->swseq_erase ? 'S' : 'H');
 240 }
 241
 242 /* Reads max INTEL_SPI_FIFO_SZ bytes from the device fifo */
 243 static int intel_spi_read_block(struct intel_spi *ispi, void *buf, size_t size)
 244 {
 245         size_t bytes;
 246         int i = 0;
 247
 248         if (size > INTEL_SPI_FIFO_SZ)
 249                 return -EINVAL;
 250
 251         while (size > 0) {
 252                 bytes = min_t(size_t, size, 4);
 253                 memcpy_fromio(buf, ispi->base + FDATA(i), bytes);
 254                 size -= bytes;
 255                 buf += bytes;
 256                 i++;
 257         }
 258
 259         return 0;
 260 }
 261
 262 /* Writes max INTEL_SPI_FIFO_SZ bytes to the device fifo */
 263 static int intel_spi_write_block(struct intel_spi *ispi, const void *buf,
 264                                  size_t size)
 265 {
 266         size_t bytes;
 267         int i = 0;
 268
 269         if (size > INTEL_SPI_FIFO_SZ)
 270                 return -EINVAL;
 271
 272         while (size > 0) {
 273                 bytes = min_t(size_t, size, 4);
 274                 memcpy_toio(ispi->base + FDATA(i), buf, bytes);
 275                 size -= bytes;
 276                 buf += bytes;
 277                 i++;
 278         }
 279
 280         return 0;
 281 }
 282
 283 static int intel_spi_wait_hw_busy(struct intel_spi *ispi)
 284 {
 285         u32 val;
 286
 287         return readl_poll_timeout(ispi->base + HSFSTS_CTL, val,
 288                                   !(val & HSFSTS_CTL_SCIP), 0,
 289                                   INTEL_SPI_TIMEOUT * 1000);
 290 }
 291
 292 static int intel_spi_wait_sw_busy(struct intel_spi *ispi)
 293 {
 294         u32 val;
 295
 296         return readl_poll_timeout(ispi->sregs + SSFSTS_CTL, val,
 297                                   !(val & SSFSTS_CTL_SCIP), 0,
 298                                   INTEL_SPI_TIMEOUT * 1000);
 299 }
 300
 301 static int intel_spi_init(struct intel_spi *ispi)
 302 {
 303         u32 opmenu0, opmenu1, lvscc, uvscc, val;
 304         int i;
 305
 306         switch (ispi->info->type) {
 307         case INTEL_SPI_BYT:
 308                 ispi->sregs = ispi->base + BYT_SSFSTS_CTL;
 309                 ispi->pregs = ispi->base + BYT_PR;
 310                 ispi->nregions = BYT_FREG_NUM;
 311                 ispi->pr_num = BYT_PR_NUM;
 312                 ispi->swseq_reg = true;
 313
 314                 if (writeable) {
 315                         /* Disable write protection */
 316                         val = readl(ispi->base + BYT_BCR);
 317                         if (!(val & BYT_BCR_WPD)) {
 318                                 val |= BYT_BCR_WPD;
 319                                 writel(val, ispi->base + BYT_BCR);
 320                                 val = readl(ispi->base + BYT_BCR);
 321                         }
 322
 323                         ispi->writeable = !!(val & BYT_BCR_WPD);
 324                 }
 325
 326                 break;
 327
 328         case INTEL_SPI_LPT:
 329                 ispi->sregs = ispi->base + LPT_SSFSTS_CTL;
 330                 ispi->pregs = ispi->base + LPT_PR;
 331                 ispi->nregions = LPT_FREG_NUM;
 332                 ispi->pr_num = LPT_PR_NUM;
 333                 ispi->swseq_reg = true;
 334                 break;
 335
 336         case INTEL_SPI_BXT:
 337                 ispi->sregs = ispi->base + BXT_SSFSTS_CTL;
 338                 ispi->pregs = ispi->base + BXT_PR;
 339                 ispi->nregions = BXT_FREG_NUM;
 340                 ispi->pr_num = BXT_PR_NUM;
 341                 ispi->erase_64k = true;
 342                 break;
 343
 344         default:
 345                 return -EINVAL;
 346         }
 347
 348         /* Disable #SMI generation from HW sequencer */
 349         val = readl(ispi->base + HSFSTS_CTL);
 350         val &= ~HSFSTS_CTL_FSMIE;
 351         writel(val, ispi->base + HSFSTS_CTL);
 352
 353         /*
 354          * Determine whether erase operation should use HW or SW sequencer.
 355          *
 356          * The HW sequencer has a predefined list of opcodes, with only the
 357          * erase opcode being programmable in LVSCC and UVSCC registers.
 358          * If these registers don't contain a valid erase opcode, erase
 359          * cannot be done using HW sequencer.
 360          */
 361         lvscc = readl(ispi->base + LVSCC);
 362         uvscc = readl(ispi->base + UVSCC);
 363         if (!(lvscc & ERASE_OPCODE_MASK) || !(uvscc & ERASE_OPCODE_MASK))
 364                 ispi->swseq_erase = true;
 365         /* SPI controller on Intel BXT supports 64K erase opcode */
 366         if (ispi->info->type == INTEL_SPI_BXT && !ispi->swseq_erase)
 367                 if (!(lvscc & ERASE_64K_OPCODE_MASK) ||
 368                     !(uvscc & ERASE_64K_OPCODE_MASK))
 369                         ispi->erase_64k = false;
 370
 371         /*
 372          * Some controllers can only do basic operations using hardware
 373          * sequencer. All other operations are supposed to be carried out
 374          * using software sequencer.
 375          */
 376         if (ispi->swseq_reg) {
 377                 /* Disable #SMI generation from SW sequencer */
 378                 val = readl(ispi->sregs + SSFSTS_CTL);
 379                 val &= ~SSFSTS_CTL_FSMIE;
 380                 writel(val, ispi->sregs + SSFSTS_CTL);
 381         }
 382
 383         /* Check controller's lock status */
 384         val = readl(ispi->base + HSFSTS_CTL);
 385         ispi->locked = !!(val & HSFSTS_CTL_FLOCKDN);
 386
 387         if (ispi->locked) {
 388                 /*
 389                  * BIOS programs allowed opcodes and then locks down the
 390                  * register. So read back what opcodes it decided to support.
 391                  * That's the set we are going to support as well.
 392                  */
 393                 opmenu0 = readl(ispi->sregs + OPMENU0);
 394                 opmenu1 = readl(ispi->sregs + OPMENU1);
 395
 396                 if (opmenu0 && opmenu1) {
 397                         for (i = 0; i < ARRAY_SIZE(ispi->opcodes) / 2; i++) {
 398                                 ispi->opcodes[i] = opmenu0 >> i * 8;
 399                                 ispi->opcodes[i + 4] = opmenu1 >> i * 8;
 400                         }
 401                 }
 402         }
 403
 404         intel_spi_dump_regs(ispi);
 405
 406         return 0;
 407 }
 408
 409 static int intel_spi_opcode_index(struct intel_spi *ispi, u8 opcode, int optype)
 410 {
 411         int i;
 412         int preop;
 413
 414         if (ispi->locked) {
 415                 for (i = 0; i < ARRAY_SIZE(ispi->opcodes); i++)
 416                         if (ispi->opcodes[i] == opcode)
 417                                 return i;
 418
 419                 return -EINVAL;
 420         }
 421
 422         /* The lock is off, so just use index 0 */
 423         writel(opcode, ispi->sregs + OPMENU0);
 424         preop = readw(ispi->sregs + PREOP_OPTYPE);
 425         writel(optype << 16 | preop, ispi->sregs + PREOP_OPTYPE);
 426
 427         return 0;
 428 }
 429
 430 static int intel_spi_hw_cycle(struct intel_spi *ispi, u8 opcode, int len)
 431 {
 432         u32 val, status;
 433         int ret;
 434
 435         val = readl(ispi->base + HSFSTS_CTL);
 436         val &= ~(HSFSTS_CTL_FCYCLE_MASK | HSFSTS_CTL_FDBC_MASK);
 437
 438         switch (opcode) {
 439         case SPINOR_OP_RDID:
 440                 val |= HSFSTS_CTL_FCYCLE_RDID;
 441                 break;
 442         case SPINOR_OP_WRSR:
 443                 val |= HSFSTS_CTL_FCYCLE_WRSR;
 444                 break;
 445         case SPINOR_OP_RDSR:
 446                 val |= HSFSTS_CTL_FCYCLE_RDSR;
 447                 break;
 448         default:
 449                 return -EINVAL;
 450         }
 451
 452         if (len > INTEL_SPI_FIFO_SZ)
 453                 return -EINVAL;
 454
 455         val |= (len - 1) << HSFSTS_CTL_FDBC_SHIFT;
 456         val |= HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
 457         val |= HSFSTS_CTL_FGO;
 458         writel(val, ispi->base + HSFSTS_CTL);
 459
 460         ret = intel_spi_wait_hw_busy(ispi);
 461         if (ret)
 462                 return ret;
 463
 464         status = readl(ispi->base + HSFSTS_CTL);
 465         if (status & HSFSTS_CTL_FCERR)
 466                 return -EIO;
 467         else if (status & HSFSTS_CTL_AEL)
 468                 return -EACCES;
 469
 470         return 0;
 471 }
 472
 473 static int intel_spi_sw_cycle(struct intel_spi *ispi, u8 opcode, int len,
 474                               int optype)
 475 {
 476         u32 val = 0, status;
 477         u16 preop;
 478         int ret;
 479
 480         ret = intel_spi_opcode_index(ispi, opcode, optype);
 481         if (ret < 0)
 482                 return ret;
 483
 484         if (len > INTEL_SPI_FIFO_SZ)
 485                 return -EINVAL;
 486
 487         /* Only mark 'Data Cycle' bit when there is data to be transferred */
 488         if (len > 0)
 489                 val = ((len - 1) << SSFSTS_CTL_DBC_SHIFT) | SSFSTS_CTL_DS;
 490         val |= ret << SSFSTS_CTL_COP_SHIFT;
 491         val |= SSFSTS_CTL_FCERR | SSFSTS_CTL_FDONE;
 492         val |= SSFSTS_CTL_SCGO;
 493         preop = readw(ispi->sregs + PREOP_OPTYPE);
 494         if (preop) {
 495                 val |= SSFSTS_CTL_ACS;
 496                 if (preop >> 8)
 497                         val |= SSFSTS_CTL_SPOP;
 498         }
 499         writel(val, ispi->sregs + SSFSTS_CTL);
 500
 501         ret = intel_spi_wait_sw_busy(ispi);
 502         if (ret)
 503                 return ret;
 504
 505         status = readl(ispi->sregs + SSFSTS_CTL);
 506         if (status & SSFSTS_CTL_FCERR)
 507                 return -EIO;
 508         else if (status & SSFSTS_CTL_AEL)
 509                 return -EACCES;
 510
 511         return 0;
 512 }
 513
 514 static int intel_spi_read_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
 515 {
 516         struct intel_spi *ispi = nor->priv;
 517         int ret;
 518
 519         /* Address of the first chip */
 520         writel(0, ispi->base + FADDR);
 521
 522         if (ispi->swseq_reg)
 523                 ret = intel_spi_sw_cycle(ispi, opcode, len,
 524                                          OPTYPE_READ_NO_ADDR);
 525         else
 526                 ret = intel_spi_hw_cycle(ispi, opcode, len);
 527
 528         if (ret)
 529                 return ret;
 530
 531         return intel_spi_read_block(ispi, buf, len);
 532 }
 533
 534 static int intel_spi_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
 535 {
 536         struct intel_spi *ispi = nor->priv;
 537         int ret;
 538
 539         /*
 540          * This is handled with atomic operation and preop code in Intel
 541          * controller so skip it here now. If the controller is not locked,
 542          * program the opcode to the PREOP register for later use.
 543          */
 544         if (opcode == SPINOR_OP_WREN) {
 545                 if (!ispi->locked)
 546                         writel(opcode, ispi->sregs + PREOP_OPTYPE);
 547
 548                 return 0;
 549         }
 550
 551         writel(0, ispi->base + FADDR);
 552
 553         /* Write the value beforehand */
 554         ret = intel_spi_write_block(ispi, buf, len);
 555         if (ret)
 556                 return ret;
 557
 558         if (ispi->swseq_reg)
 559                 return intel_spi_sw_cycle(ispi, opcode, len,
 560                                           OPTYPE_WRITE_NO_ADDR);
 561         return intel_spi_hw_cycle(ispi, opcode, len);
 562 }
 563
 564 static ssize_t intel_spi_read(struct spi_nor *nor, loff_t from, size_t len,
 565                               u_char *read_buf)
 566 {
 567         struct intel_spi *ispi = nor->priv;
 568         size_t block_size, retlen = 0;
 569         u32 val, status;
 570         ssize_t ret;
 571
 572         switch (nor->read_opcode) {
 573         case SPINOR_OP_READ:
 574         case SPINOR_OP_READ_FAST:
 575                 break;
 576         default:
 577                 return -EINVAL;
 578         }
 579
 580         while (len > 0) {
 581                 block_size = min_t(size_t, len, INTEL_SPI_FIFO_SZ);
 582
 583                 writel(from, ispi->base + FADDR);
 584
 585                 val = readl(ispi->base + HSFSTS_CTL);
 586                 val &= ~(HSFSTS_CTL_FDBC_MASK | HSFSTS_CTL_FCYCLE_MASK);
 587                 val |= HSFSTS_CTL_AEL | HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
 588                 val |= (block_size - 1) << HSFSTS_CTL_FDBC_SHIFT;
 589                 val |= HSFSTS_CTL_FCYCLE_READ;
 590                 val |= HSFSTS_CTL_FGO;
 591                 writel(val, ispi->base + HSFSTS_CTL);
 592
 593                 ret = intel_spi_wait_hw_busy(ispi);
 594                 if (ret)
 595                         return ret;
 596
 597                 status = readl(ispi->base + HSFSTS_CTL);
 598                 if (status & HSFSTS_CTL_FCERR)
 599                         ret = -EIO;
 600                 else if (status & HSFSTS_CTL_AEL)
 601                         ret = -EACCES;
 602
 603                 if (ret < 0) {
 604                         dev_err(ispi->dev, "read error: %llx: %#x\n", from,
 605                                 status);
 606                         return ret;
 607                 }
 608
 609                 ret = intel_spi_read_block(ispi, read_buf, block_size);
 610                 if (ret)
 611                         return ret;
 612
 613                 len -= block_size;
 614                 from += block_size;
 615                 retlen += block_size;
 616                 read_buf += block_size;
 617         }
 618
 619         return retlen;
 620 }
 621
 622 static ssize_t intel_spi_write(struct spi_nor *nor, loff_t to, size_t len,
 623                                const u_char *write_buf)
 624 {
 625         struct intel_spi *ispi = nor->priv;
 626         size_t block_size, retlen = 0;
 627         u32 val, status;
 628         ssize_t ret;
 629
 630         while (len > 0) {
 631                 block_size = min_t(size_t, len, INTEL_SPI_FIFO_SZ);
 632
 633                 writel(to, ispi->base + FADDR);
 634
 635                 val = readl(ispi->base + HSFSTS_CTL);
 636                 val &= ~(HSFSTS_CTL_FDBC_MASK | HSFSTS_CTL_FCYCLE_MASK);
 637                 val |= HSFSTS_CTL_AEL | HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
 638                 val |= (block_size - 1) << HSFSTS_CTL_FDBC_SHIFT;
 639                 val |= HSFSTS_CTL_FCYCLE_WRITE;
 640
 641                 ret = intel_spi_write_block(ispi, write_buf, block_size);
 642                 if (ret) {
 643                         dev_err(ispi->dev, "failed to write block\n");
 644                         return ret;
 645                 }
 646
 647                 /* Start the write now */
 648                 val |= HSFSTS_CTL_FGO;
 649                 writel(val, ispi->base + HSFSTS_CTL);
 650
 651                 ret = intel_spi_wait_hw_busy(ispi);
 652                 if (ret) {
 653                         dev_err(ispi->dev, "timeout\n");
 654                         return ret;
 655                 }
 656
 657                 status = readl(ispi->base + HSFSTS_CTL);
 658                 if (status & HSFSTS_CTL_FCERR)
 659                         ret = -EIO;
 660                 else if (status & HSFSTS_CTL_AEL)
 661                         ret = -EACCES;
 662
 663                 if (ret < 0) {
 664                         dev_err(ispi->dev, "write error: %llx: %#x\n", to,
 665                                 status);
 666                         return ret;
 667                 }
 668
 669                 len -= block_size;
 670                 to += block_size;
 671                 retlen += block_size;
 672                 write_buf += block_size;
 673         }
 674
 675         return retlen;
 676 }
 677
 678 static int intel_spi_erase(struct spi_nor *nor, loff_t offs)
 679 {
 680         size_t erase_size, len = nor->mtd.erasesize;
 681         struct intel_spi *ispi = nor->priv;
 682         u32 val, status, cmd;
 683         int ret;
 684
 685         /* If the hardware can do 64k erase use that when possible */
 686         if (len >= SZ_64K && ispi->erase_64k) {
 687                 cmd = HSFSTS_CTL_FCYCLE_ERASE_64K;
 688                 erase_size = SZ_64K;
 689         } else {
 690                 cmd = HSFSTS_CTL_FCYCLE_ERASE;
 691                 erase_size = SZ_4K;
 692         }
 693
 694         if (ispi->swseq_erase) {
 695                 while (len > 0) {
 696                         writel(offs, ispi->base + FADDR);
 697
 698                         ret = intel_spi_sw_cycle(ispi, nor->erase_opcode,
 699                                                  0, OPTYPE_WRITE_WITH_ADDR);
 700                         if (ret)
 701                                 return ret;
 702
 703                         offs += erase_size;
 704                         len -= erase_size;
 705                 }
 706
 707                 return 0;
 708         }
 709
 710         while (len > 0) {
 711                 writel(offs, ispi->base + FADDR);
 712
 713                 val = readl(ispi->base + HSFSTS_CTL);
 714                 val &= ~(HSFSTS_CTL_FDBC_MASK | HSFSTS_CTL_FCYCLE_MASK);
 715                 val |= HSFSTS_CTL_AEL | HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
 716                 val |= cmd;
 717                 val |= HSFSTS_CTL_FGO;
 718                 writel(val, ispi->base + HSFSTS_CTL);
 719
 720                 ret = intel_spi_wait_hw_busy(ispi);
 721                 if (ret)
 722                         return ret;
 723
 724                 status = readl(ispi->base + HSFSTS_CTL);
 725                 if (status & HSFSTS_CTL_FCERR)
 726                         return -EIO;
 727                 else if (status & HSFSTS_CTL_AEL)
 728                         return -EACCES;
 729
 730                 offs += erase_size;
 731                 len -= erase_size;
 732         }
 733
 734         return 0;
 735 }
 736
 737 static bool intel_spi_is_protected(const struct intel_spi *ispi,
 738                                    unsigned int base, unsigned int limit)
 739 {
 740         int i;
 741
 742         for (i = 0; i < ispi->pr_num; i++) {
 743                 u32 pr_base, pr_limit, pr_value;
 744
 745                 pr_value = readl(ispi->pregs + PR(i));
 746                 if (!(pr_value & (PR_WPE | PR_RPE)))
 747                         continue;
 748
 749                 pr_limit = (pr_value & PR_LIMIT_MASK) >> PR_LIMIT_SHIFT;
 750                 pr_base = pr_value & PR_BASE_MASK;
 751
 752                 if (pr_base >= base && pr_limit <= limit)
 753                         return true;
 754         }
 755
 756         return false;
 757 }
 758
 759 /*
 760  * There will be a single partition holding all enabled flash regions. We
 761  * call this "BIOS".
 762  */
 763 static void intel_spi_fill_partition(struct intel_spi *ispi,
 764                                      struct mtd_partition *part)
 765 {
 766         u64 end;
 767         int i;
 768
 769         memset(part, 0, sizeof(*part));
 770
 771         /* Start from the mandatory descriptor region */
 772         part->size = 4096;
 773         part->name = "BIOS";
 774
 775         /*
 776          * Now try to find where this partition ends based on the flash
 777          * region registers.
 778          */
 779         for (i = 1; i < ispi->nregions; i++) {
 780                 u32 region, base, limit;
 781
 782                 region = readl(ispi->base + FREG(i));
 783                 base = region & FREG_BASE_MASK;
 784                 limit = (region & FREG_LIMIT_MASK) >> FREG_LIMIT_SHIFT;
 785
 786                 if (base >= limit || limit == 0)
 787                         continue;
 788
 789                 /*
 790                  * If any of the regions have protection bits set, make the
 791                  * whole partition read-only to be on the safe side.
 792                  */
 793                 if (intel_spi_is_protected(ispi, base, limit))
 794                         ispi->writeable = false;
 795
 796                 end = (limit << 12) + 4096;
 797                 if (end > part->size)
 798                         part->size = end;
 799         }
 800 }
 801
 802 struct intel_spi *intel_spi_probe(struct device *dev,
 803         struct resource *mem, const struct intel_spi_boardinfo *info)
 804 {
 805         const struct spi_nor_hwcaps hwcaps = {
 806                 .mask = SNOR_HWCAPS_READ |
 807                         SNOR_HWCAPS_READ_FAST |
 808                         SNOR_HWCAPS_PP,
 809         };
 810         struct mtd_partition part;
 811         struct intel_spi *ispi;
 812         int ret;
 813
 814         if (!info || !mem)
 815                 return ERR_PTR(-EINVAL);
 816
 817         ispi = devm_kzalloc(dev, sizeof(*ispi), GFP_KERNEL);
 818         if (!ispi)
 819                 return ERR_PTR(-ENOMEM);
 820
 821         ispi->base = devm_ioremap_resource(dev, mem);
 822         if (IS_ERR(ispi->base))
 823                 return ERR_CAST(ispi->base);
 824
 825         ispi->dev = dev;
 826         ispi->info = info;
 827         ispi->writeable = info->writeable;
 828
 829         ret = intel_spi_init(ispi);
 830         if (ret)
 831                 return ERR_PTR(ret);
 832
 833         ispi->nor.dev = ispi->dev;
 834         ispi->nor.priv = ispi;
 835         ispi->nor.read_reg = intel_spi_read_reg;
 836         ispi->nor.write_reg = intel_spi_write_reg;
 837         ispi->nor.read = intel_spi_read;
 838         ispi->nor.write = intel_spi_write;
 839         ispi->nor.erase = intel_spi_erase;
 840
 841         ret = spi_nor_scan(&ispi->nor, NULL, &hwcaps);
 842         if (ret) {
 843                 dev_info(dev, "failed to locate the chip\n");
 844                 return ERR_PTR(ret);
 845         }
 846
 847         intel_spi_fill_partition(ispi, &part);
 848
 849         /* Prevent writes if not explicitly enabled */
 850         if (!ispi->writeable || !writeable)
 851                 ispi->nor.mtd.flags &= ~MTD_WRITEABLE;
 852
 853         ret = mtd_device_parse_register(&ispi->nor.mtd, NULL, NULL, &part, 1);
 854         if (ret)
 855                 return ERR_PTR(ret);
 856
 857         return ispi;
 858 }
 859 EXPORT_SYMBOL_GPL(intel_spi_probe);
 860
 861 int intel_spi_remove(struct intel_spi *ispi)
 862 {
 863         return mtd_device_unregister(&ispi->nor.mtd);
 864 }
 865 EXPORT_SYMBOL_GPL(intel_spi_remove);
 866
 867 MODULE_DESCRIPTION("Intel PCH/PCU SPI flash core driver");
 868 MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
 869 MODULE_LICENSE("GPL v2");