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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Intel PCH/PCU SPI flash driver.
   4  *
   5  * Copyright (C) 2016, Intel Corporation
   6  * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
   7  */
   8
   9 #include <linux/err.h>
  10 #include <linux/io.h>
  11 #include <linux/iopoll.h>
  12 #include <linux/module.h>
  13 #include <linux/sched.h>
  14 #include <linux/sizes.h>
  15 #include <linux/mtd/mtd.h>
  16 #include <linux/mtd/partitions.h>
  17 #include <linux/mtd/spi-nor.h>
  18 #include <linux/platform_data/intel-spi.h>
  19
  20 #include "intel-spi.h"
  21
  22 /* Offsets are from @ispi->base */
  23 #define BFPREG                          0x00
  24
  25 #define HSFSTS_CTL                      0x04
  26 #define HSFSTS_CTL_FSMIE                BIT(31)
  27 #define HSFSTS_CTL_FDBC_SHIFT           24
  28 #define HSFSTS_CTL_FDBC_MASK            (0x3f << HSFSTS_CTL_FDBC_SHIFT)
  29
  30 #define HSFSTS_CTL_FCYCLE_SHIFT         17
  31 #define HSFSTS_CTL_FCYCLE_MASK          (0x0f << HSFSTS_CTL_FCYCLE_SHIFT)
  32 /* HW sequencer opcodes */
  33 #define HSFSTS_CTL_FCYCLE_READ          (0x00 << HSFSTS_CTL_FCYCLE_SHIFT)
  34 #define HSFSTS_CTL_FCYCLE_WRITE         (0x02 << HSFSTS_CTL_FCYCLE_SHIFT)
  35 #define HSFSTS_CTL_FCYCLE_ERASE         (0x03 << HSFSTS_CTL_FCYCLE_SHIFT)
  36 #define HSFSTS_CTL_FCYCLE_ERASE_64K     (0x04 << HSFSTS_CTL_FCYCLE_SHIFT)
  37 #define HSFSTS_CTL_FCYCLE_RDID          (0x06 << HSFSTS_CTL_FCYCLE_SHIFT)
  38 #define HSFSTS_CTL_FCYCLE_WRSR          (0x07 << HSFSTS_CTL_FCYCLE_SHIFT)
  39 #define HSFSTS_CTL_FCYCLE_RDSR          (0x08 << HSFSTS_CTL_FCYCLE_SHIFT)
  40
  41 #define HSFSTS_CTL_FGO                  BIT(16)
  42 #define HSFSTS_CTL_FLOCKDN              BIT(15)
  43 #define HSFSTS_CTL_FDV                  BIT(14)
  44 #define HSFSTS_CTL_SCIP                 BIT(5)
  45 #define HSFSTS_CTL_AEL                  BIT(2)
  46 #define HSFSTS_CTL_FCERR                BIT(1)
  47 #define HSFSTS_CTL_FDONE                BIT(0)
  48
  49 #define FADDR                           0x08
  50 #define DLOCK                           0x0c
  51 #define FDATA(n)                        (0x10 + ((n) * 4))
  52
  53 #define FRACC                           0x50
  54
  55 #define FREG(n)                         (0x54 + ((n) * 4))
  56 #define FREG_BASE_MASK                  0x3fff
  57 #define FREG_LIMIT_SHIFT                16
  58 #define FREG_LIMIT_MASK                 (0x03fff << FREG_LIMIT_SHIFT)
  59
  60 /* Offset is from @ispi->pregs */
  61 #define PR(n)                           ((n) * 4)
  62 #define PR_WPE                          BIT(31)
  63 #define PR_LIMIT_SHIFT                  16
  64 #define PR_LIMIT_MASK                   (0x3fff << PR_LIMIT_SHIFT)
  65 #define PR_RPE                          BIT(15)
  66 #define PR_BASE_MASK                    0x3fff
  67
  68 /* Offsets are from @ispi->sregs */
  69 #define SSFSTS_CTL                      0x00
  70 #define SSFSTS_CTL_FSMIE                BIT(23)
  71 #define SSFSTS_CTL_DS                   BIT(22)
  72 #define SSFSTS_CTL_DBC_SHIFT            16
  73 #define SSFSTS_CTL_SPOP                 BIT(11)
  74 #define SSFSTS_CTL_ACS                  BIT(10)
  75 #define SSFSTS_CTL_SCGO                 BIT(9)
  76 #define SSFSTS_CTL_COP_SHIFT            12
  77 #define SSFSTS_CTL_FRS                  BIT(7)
  78 #define SSFSTS_CTL_DOFRS                BIT(6)
  79 #define SSFSTS_CTL_AEL                  BIT(4)
  80 #define SSFSTS_CTL_FCERR                BIT(3)
  81 #define SSFSTS_CTL_FDONE                BIT(2)
  82 #define SSFSTS_CTL_SCIP                 BIT(0)
  83
  84 #define PREOP_OPTYPE                    0x04
  85 #define OPMENU0                         0x08
  86 #define OPMENU1                         0x0c
  87
  88 #define OPTYPE_READ_NO_ADDR             0
  89 #define OPTYPE_WRITE_NO_ADDR            1
  90 #define OPTYPE_READ_WITH_ADDR           2
  91 #define OPTYPE_WRITE_WITH_ADDR          3
  92
  93 /* CPU specifics */
  94 #define BYT_PR                          0x74
  95 #define BYT_SSFSTS_CTL                  0x90
  96 #define BYT_BCR                         0xfc
  97 #define BYT_BCR_WPD                     BIT(0)
  98 #define BYT_FREG_NUM                    5
  99 #define BYT_PR_NUM                      5
 100
 101 #define LPT_PR                          0x74
 102 #define LPT_SSFSTS_CTL                  0x90
 103 #define LPT_FREG_NUM                    5
 104 #define LPT_PR_NUM                      5
 105
 106 #define BXT_PR                          0x84
 107 #define BXT_SSFSTS_CTL                  0xa0
 108 #define BXT_FREG_NUM                    12
 109 #define BXT_PR_NUM                      6
 110
 111 #define LVSCC                           0xc4
 112 #define UVSCC                           0xc8
 113 #define ERASE_OPCODE_SHIFT              8
 114 #define ERASE_OPCODE_MASK               (0xff << ERASE_OPCODE_SHIFT)
 115 #define ERASE_64K_OPCODE_SHIFT          16
 116 #define ERASE_64K_OPCODE_MASK           (0xff << ERASE_OPCODE_SHIFT)
 117
 118 #define INTEL_SPI_TIMEOUT               5000 /* ms */
 119 #define INTEL_SPI_FIFO_SZ               64
 120
 121 /**
 122  * struct intel_spi - Driver private data
 123  * @dev: Device pointer
 124  * @info: Pointer to board specific info
 125  * @nor: SPI NOR layer structure
 126  * @base: Beginning of MMIO space
 127  * @pregs: Start of protection registers
 128  * @sregs: Start of software sequencer registers
 129  * @nregions: Maximum number of regions
 130  * @pr_num: Maximum number of protected range registers
 131  * @writeable: Is the chip writeable
 132  * @locked: Is SPI setting locked
 133  * @swseq_reg: Use SW sequencer in register reads/writes
 134  * @swseq_erase: Use SW sequencer in erase operation
 135  * @erase_64k: 64k erase supported
 136  * @atomic_preopcode: Holds preopcode when atomic sequence is requested
 137  * @opcodes: Opcodes which are supported. This are programmed by BIOS
 138  *           before it locks down the controller.
 139  */
 140 struct intel_spi {
 141         struct device *dev;
 142         const struct intel_spi_boardinfo *info;
 143         struct spi_nor nor;
 144         void __iomem *base;
 145         void __iomem *pregs;
 146         void __iomem *sregs;
 147         size_t nregions;
 148         size_t pr_num;
 149         bool writeable;
 150         bool locked;
 151         bool swseq_reg;
 152         bool swseq_erase;
 153         bool erase_64k;
 154         u8 atomic_preopcode;
 155         u8 opcodes[8];
 156 };
 157
 158 static bool writeable;
 159 module_param(writeable, bool, 0);
 160 MODULE_PARM_DESC(writeable, "Enable write access to SPI flash chip (default=0)");
 161
 162 static void intel_spi_dump_regs(struct intel_spi *ispi)
 163 {
 164         u32 value;
 165         int i;
 166
 167         dev_dbg(ispi->dev, "BFPREG=0x%08x\n", readl(ispi->base + BFPREG));
 168
 169         value = readl(ispi->base + HSFSTS_CTL);
 170         dev_dbg(ispi->dev, "HSFSTS_CTL=0x%08x\n", value);
 171         if (value & HSFSTS_CTL_FLOCKDN)
 172                 dev_dbg(ispi->dev, "-> Locked\n");
 173
 174         dev_dbg(ispi->dev, "FADDR=0x%08x\n", readl(ispi->base + FADDR));
 175         dev_dbg(ispi->dev, "DLOCK=0x%08x\n", readl(ispi->base + DLOCK));
 176
 177         for (i = 0; i < 16; i++)
 178                 dev_dbg(ispi->dev, "FDATA(%d)=0x%08x\n",
 179                         i, readl(ispi->base + FDATA(i)));
 180
 181         dev_dbg(ispi->dev, "FRACC=0x%08x\n", readl(ispi->base + FRACC));
 182
 183         for (i = 0; i < ispi->nregions; i++)
 184                 dev_dbg(ispi->dev, "FREG(%d)=0x%08x\n", i,
 185                         readl(ispi->base + FREG(i)));
 186         for (i = 0; i < ispi->pr_num; i++)
 187                 dev_dbg(ispi->dev, "PR(%d)=0x%08x\n", i,
 188                         readl(ispi->pregs + PR(i)));
 189
 190         value = readl(ispi->sregs + SSFSTS_CTL);
 191         dev_dbg(ispi->dev, "SSFSTS_CTL=0x%08x\n", value);
 192         dev_dbg(ispi->dev, "PREOP_OPTYPE=0x%08x\n",
 193                 readl(ispi->sregs + PREOP_OPTYPE));
 194         dev_dbg(ispi->dev, "OPMENU0=0x%08x\n", readl(ispi->sregs + OPMENU0));
 195         dev_dbg(ispi->dev, "OPMENU1=0x%08x\n", readl(ispi->sregs + OPMENU1));
 196
 197         if (ispi->info->type == INTEL_SPI_BYT)
 198                 dev_dbg(ispi->dev, "BCR=0x%08x\n", readl(ispi->base + BYT_BCR));
 199
 200         dev_dbg(ispi->dev, "LVSCC=0x%08x\n", readl(ispi->base + LVSCC));
 201         dev_dbg(ispi->dev, "UVSCC=0x%08x\n", readl(ispi->base + UVSCC));
 202
 203         dev_dbg(ispi->dev, "Protected regions:\n");
 204         for (i = 0; i < ispi->pr_num; i++) {
 205                 u32 base, limit;
 206
 207                 value = readl(ispi->pregs + PR(i));
 208                 if (!(value & (PR_WPE | PR_RPE)))
 209                         continue;
 210
 211                 limit = (value & PR_LIMIT_MASK) >> PR_LIMIT_SHIFT;
 212                 base = value & PR_BASE_MASK;
 213
 214                 dev_dbg(ispi->dev, " %02d base: 0x%08x limit: 0x%08x [%c%c]\n",
 215                          i, base << 12, (limit << 12) | 0xfff,
 216                          value & PR_WPE ? 'W' : '.',
 217                          value & PR_RPE ? 'R' : '.');
 218         }
 219
 220         dev_dbg(ispi->dev, "Flash regions:\n");
 221         for (i = 0; i < ispi->nregions; i++) {
 222                 u32 region, base, limit;
 223
 224                 region = readl(ispi->base + FREG(i));
 225                 base = region & FREG_BASE_MASK;
 226                 limit = (region & FREG_LIMIT_MASK) >> FREG_LIMIT_SHIFT;
 227
 228                 if (base >= limit || (i > 0 && limit == 0))
 229                         dev_dbg(ispi->dev, " %02d disabled\n", i);
 230                 else
 231                         dev_dbg(ispi->dev, " %02d base: 0x%08x limit: 0x%08x\n",
 232                                  i, base << 12, (limit << 12) | 0xfff);
 233         }
 234
 235         dev_dbg(ispi->dev, "Using %cW sequencer for register access\n",
 236                 ispi->swseq_reg ? 'S' : 'H');
 237         dev_dbg(ispi->dev, "Using %cW sequencer for erase operation\n",
 238                 ispi->swseq_erase ? 'S' : 'H');
 239 }
 240
 241 /* Reads max INTEL_SPI_FIFO_SZ bytes from the device fifo */
 242 static int intel_spi_read_block(struct intel_spi *ispi, void *buf, size_t size)
 243 {
 244         size_t bytes;
 245         int i = 0;
 246
 247         if (size > INTEL_SPI_FIFO_SZ)
 248                 return -EINVAL;
 249
 250         while (size > 0) {
 251                 bytes = min_t(size_t, size, 4);
 252                 memcpy_fromio(buf, ispi->base + FDATA(i), bytes);
 253                 size -= bytes;
 254                 buf += bytes;
 255                 i++;
 256         }
 257
 258         return 0;
 259 }
 260
 261 /* Writes max INTEL_SPI_FIFO_SZ bytes to the device fifo */
 262 static int intel_spi_write_block(struct intel_spi *ispi, const void *buf,
 263                                  size_t size)
 264 {
 265         size_t bytes;
 266         int i = 0;
 267
 268         if (size > INTEL_SPI_FIFO_SZ)
 269                 return -EINVAL;
 270
 271         while (size > 0) {
 272                 bytes = min_t(size_t, size, 4);
 273                 memcpy_toio(ispi->base + FDATA(i), buf, bytes);
 274                 size -= bytes;
 275                 buf += bytes;
 276                 i++;
 277         }
 278
 279         return 0;
 280 }
 281
 282 static int intel_spi_wait_hw_busy(struct intel_spi *ispi)
 283 {
 284         u32 val;
 285
 286         return readl_poll_timeout(ispi->base + HSFSTS_CTL, val,
 287                                   !(val & HSFSTS_CTL_SCIP), 40,
 288                                   INTEL_SPI_TIMEOUT * 1000);
 289 }
 290
 291 static int intel_spi_wait_sw_busy(struct intel_spi *ispi)
 292 {
 293         u32 val;
 294
 295         return readl_poll_timeout(ispi->sregs + SSFSTS_CTL, val,
 296                                   !(val & SSFSTS_CTL_SCIP), 40,
 297                                   INTEL_SPI_TIMEOUT * 1000);
 298 }
 299
 300 static int intel_spi_init(struct intel_spi *ispi)
 301 {
 302         u32 opmenu0, opmenu1, lvscc, uvscc, val;
 303         int i;
 304
 305         switch (ispi->info->type) {
 306         case INTEL_SPI_BYT:
 307                 ispi->sregs = ispi->base + BYT_SSFSTS_CTL;
 308                 ispi->pregs = ispi->base + BYT_PR;
 309                 ispi->nregions = BYT_FREG_NUM;
 310                 ispi->pr_num = BYT_PR_NUM;
 311                 ispi->swseq_reg = true;
 312
 313                 if (writeable) {
 314                         /* Disable write protection */
 315                         val = readl(ispi->base + BYT_BCR);
 316                         if (!(val & BYT_BCR_WPD)) {
 317                                 val |= BYT_BCR_WPD;
 318                                 writel(val, ispi->base + BYT_BCR);
 319                                 val = readl(ispi->base + BYT_BCR);
 320                         }
 321
 322                         ispi->writeable = !!(val & BYT_BCR_WPD);
 323                 }
 324
 325                 break;
 326
 327         case INTEL_SPI_LPT:
 328                 ispi->sregs = ispi->base + LPT_SSFSTS_CTL;
 329                 ispi->pregs = ispi->base + LPT_PR;
 330                 ispi->nregions = LPT_FREG_NUM;
 331                 ispi->pr_num = LPT_PR_NUM;
 332                 ispi->swseq_reg = true;
 333                 break;
 334
 335         case INTEL_SPI_BXT:
 336                 ispi->sregs = ispi->base + BXT_SSFSTS_CTL;
 337                 ispi->pregs = ispi->base + BXT_PR;
 338                 ispi->nregions = BXT_FREG_NUM;
 339                 ispi->pr_num = BXT_PR_NUM;
 340                 ispi->erase_64k = true;
 341                 break;
 342
 343         default:
 344                 return -EINVAL;
 345         }
 346
 347         /* Disable #SMI generation from HW sequencer */
 348         val = readl(ispi->base + HSFSTS_CTL);
 349         val &= ~HSFSTS_CTL_FSMIE;
 350         writel(val, ispi->base + HSFSTS_CTL);
 351
 352         /*
 353          * Determine whether erase operation should use HW or SW sequencer.
 354          *
 355          * The HW sequencer has a predefined list of opcodes, with only the
 356          * erase opcode being programmable in LVSCC and UVSCC registers.
 357          * If these registers don't contain a valid erase opcode, erase
 358          * cannot be done using HW sequencer.
 359          */
 360         lvscc = readl(ispi->base + LVSCC);
 361         uvscc = readl(ispi->base + UVSCC);
 362         if (!(lvscc & ERASE_OPCODE_MASK) || !(uvscc & ERASE_OPCODE_MASK))
 363                 ispi->swseq_erase = true;
 364         /* SPI controller on Intel BXT supports 64K erase opcode */
 365         if (ispi->info->type == INTEL_SPI_BXT && !ispi->swseq_erase)
 366                 if (!(lvscc & ERASE_64K_OPCODE_MASK) ||
 367                     !(uvscc & ERASE_64K_OPCODE_MASK))
 368                         ispi->erase_64k = false;
 369
 370         /*
 371          * Some controllers can only do basic operations using hardware
 372          * sequencer. All other operations are supposed to be carried out
 373          * using software sequencer.
 374          */
 375         if (ispi->swseq_reg) {
 376                 /* Disable #SMI generation from SW sequencer */
 377                 val = readl(ispi->sregs + SSFSTS_CTL);
 378                 val &= ~SSFSTS_CTL_FSMIE;
 379                 writel(val, ispi->sregs + SSFSTS_CTL);
 380         }
 381
 382         /* Check controller's lock status */
 383         val = readl(ispi->base + HSFSTS_CTL);
 384         ispi->locked = !!(val & HSFSTS_CTL_FLOCKDN);
 385
 386         if (ispi->locked) {
 387                 /*
 388                  * BIOS programs allowed opcodes and then locks down the
 389                  * register. So read back what opcodes it decided to support.
 390                  * That's the set we are going to support as well.
 391                  */
 392                 opmenu0 = readl(ispi->sregs + OPMENU0);
 393                 opmenu1 = readl(ispi->sregs + OPMENU1);
 394
 395                 if (opmenu0 && opmenu1) {
 396                         for (i = 0; i < ARRAY_SIZE(ispi->opcodes) / 2; i++) {
 397                                 ispi->opcodes[i] = opmenu0 >> i * 8;
 398                                 ispi->opcodes[i + 4] = opmenu1 >> i * 8;
 399                         }
 400                 }
 401         }
 402
 403         intel_spi_dump_regs(ispi);
 404
 405         return 0;
 406 }
 407
 408 static int intel_spi_opcode_index(struct intel_spi *ispi, u8 opcode, int optype)
 409 {
 410         int i;
 411         int preop;
 412
 413         if (ispi->locked) {
 414                 for (i = 0; i < ARRAY_SIZE(ispi->opcodes); i++)
 415                         if (ispi->opcodes[i] == opcode)
 416                                 return i;
 417
 418                 return -EINVAL;
 419         }
 420
 421         /* The lock is off, so just use index 0 */
 422         writel(opcode, ispi->sregs + OPMENU0);
 423         preop = readw(ispi->sregs + PREOP_OPTYPE);
 424         writel(optype << 16 | preop, ispi->sregs + PREOP_OPTYPE);
 425
 426         return 0;
 427 }
 428
 429 static int intel_spi_hw_cycle(struct intel_spi *ispi, u8 opcode, int len)
 430 {
 431         u32 val, status;
 432         int ret;
 433
 434         val = readl(ispi->base + HSFSTS_CTL);
 435         val &= ~(HSFSTS_CTL_FCYCLE_MASK | HSFSTS_CTL_FDBC_MASK);
 436
 437         switch (opcode) {
 438         case SPINOR_OP_RDID:
 439                 val |= HSFSTS_CTL_FCYCLE_RDID;
 440                 break;
 441         case SPINOR_OP_WRSR:
 442                 val |= HSFSTS_CTL_FCYCLE_WRSR;
 443                 break;
 444         case SPINOR_OP_RDSR:
 445                 val |= HSFSTS_CTL_FCYCLE_RDSR;
 446                 break;
 447         default:
 448                 return -EINVAL;
 449         }
 450
 451         if (len > INTEL_SPI_FIFO_SZ)
 452                 return -EINVAL;
 453
 454         val |= (len - 1) << HSFSTS_CTL_FDBC_SHIFT;
 455         val |= HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
 456         val |= HSFSTS_CTL_FGO;
 457         writel(val, ispi->base + HSFSTS_CTL);
 458
 459         ret = intel_spi_wait_hw_busy(ispi);
 460         if (ret)
 461                 return ret;
 462
 463         status = readl(ispi->base + HSFSTS_CTL);
 464         if (status & HSFSTS_CTL_FCERR)
 465                 return -EIO;
 466         else if (status & HSFSTS_CTL_AEL)
 467                 return -EACCES;
 468
 469         return 0;
 470 }
 471
 472 static int intel_spi_sw_cycle(struct intel_spi *ispi, u8 opcode, int len,
 473                               int optype)
 474 {
 475         u32 val = 0, status;
 476         u8 atomic_preopcode;
 477         int ret;
 478
 479         ret = intel_spi_opcode_index(ispi, opcode, optype);
 480         if (ret < 0)
 481                 return ret;
 482
 483         if (len > INTEL_SPI_FIFO_SZ)
 484                 return -EINVAL;
 485
 486         /*
 487          * Always clear it after each SW sequencer operation regardless
 488          * of whether it is successful or not.
 489          */
 490         atomic_preopcode = ispi->atomic_preopcode;
 491         ispi->atomic_preopcode = 0;
 492
 493         /* Only mark 'Data Cycle' bit when there is data to be transferred */
 494         if (len > 0)
 495                 val = ((len - 1) << SSFSTS_CTL_DBC_SHIFT) | SSFSTS_CTL_DS;
 496         val |= ret << SSFSTS_CTL_COP_SHIFT;
 497         val |= SSFSTS_CTL_FCERR | SSFSTS_CTL_FDONE;
 498         val |= SSFSTS_CTL_SCGO;
 499         if (atomic_preopcode) {
 500                 u16 preop;
 501
 502                 switch (optype) {
 503                 case OPTYPE_WRITE_NO_ADDR:
 504                 case OPTYPE_WRITE_WITH_ADDR:
 505                         /* Pick matching preopcode for the atomic sequence */
 506                         preop = readw(ispi->sregs + PREOP_OPTYPE);
 507                         if ((preop & 0xff) == atomic_preopcode)
 508                                 ; /* Do nothing */
 509                         else if ((preop >> 8) == atomic_preopcode)
 510                                 val |= SSFSTS_CTL_SPOP;
 511                         else
 512                                 return -EINVAL;
 513
 514                         /* Enable atomic sequence */
 515                         val |= SSFSTS_CTL_ACS;
 516                         break;
 517
 518                 default:
 519                         return -EINVAL;
 520                 }
 521
 522         }
 523         writel(val, ispi->sregs + SSFSTS_CTL);
 524
 525         ret = intel_spi_wait_sw_busy(ispi);
 526         if (ret)
 527                 return ret;
 528
 529         status = readl(ispi->sregs + SSFSTS_CTL);
 530         if (status & SSFSTS_CTL_FCERR)
 531                 return -EIO;
 532         else if (status & SSFSTS_CTL_AEL)
 533                 return -EACCES;
 534
 535         return 0;
 536 }
 537
 538 static int intel_spi_read_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
 539 {
 540         struct intel_spi *ispi = nor->priv;
 541         int ret;
 542
 543         /* Address of the first chip */
 544         writel(0, ispi->base + FADDR);
 545
 546         if (ispi->swseq_reg)
 547                 ret = intel_spi_sw_cycle(ispi, opcode, len,
 548                                          OPTYPE_READ_NO_ADDR);
 549         else
 550                 ret = intel_spi_hw_cycle(ispi, opcode, len);
 551
 552         if (ret)
 553                 return ret;
 554
 555         return intel_spi_read_block(ispi, buf, len);
 556 }
 557
 558 static int intel_spi_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
 559 {
 560         struct intel_spi *ispi = nor->priv;
 561         int ret;
 562
 563         /*
 564          * This is handled with atomic operation and preop code in Intel
 565          * controller so we only verify that it is available. If the
 566          * controller is not locked, program the opcode to the PREOP
 567          * register for later use.
 568          *
 569          * When hardware sequencer is used there is no need to program
 570          * any opcodes (it handles them automatically as part of a command).
 571          */
 572         if (opcode == SPINOR_OP_WREN) {
 573                 u16 preop;
 574
 575                 if (!ispi->swseq_reg)
 576                         return 0;
 577
 578                 preop = readw(ispi->sregs + PREOP_OPTYPE);
 579                 if ((preop & 0xff) != opcode && (preop >> 8) != opcode) {
 580                         if (ispi->locked)
 581                                 return -EINVAL;
 582                         writel(opcode, ispi->sregs + PREOP_OPTYPE);
 583                 }
 584
 585                 /*
 586                  * This enables atomic sequence on next SW sycle. Will
 587                  * be cleared after next operation.
 588                  */
 589                 ispi->atomic_preopcode = opcode;
 590                 return 0;
 591         }
 592
 593         writel(0, ispi->base + FADDR);
 594
 595         /* Write the value beforehand */
 596         ret = intel_spi_write_block(ispi, buf, len);
 597         if (ret)
 598                 return ret;
 599
 600         if (ispi->swseq_reg)
 601                 return intel_spi_sw_cycle(ispi, opcode, len,
 602                                           OPTYPE_WRITE_NO_ADDR);
 603         return intel_spi_hw_cycle(ispi, opcode, len);
 604 }
 605
 606 static ssize_t intel_spi_read(struct spi_nor *nor, loff_t from, size_t len,
 607                               u_char *read_buf)
 608 {
 609         struct intel_spi *ispi = nor->priv;
 610         size_t block_size, retlen = 0;
 611         u32 val, status;
 612         ssize_t ret;
 613
 614         /*
 615          * Atomic sequence is not expected with HW sequencer reads. Make
 616          * sure it is cleared regardless.
 617          */
 618         if (WARN_ON_ONCE(ispi->atomic_preopcode))
 619                 ispi->atomic_preopcode = 0;
 620
 621         switch (nor->read_opcode) {
 622         case SPINOR_OP_READ:
 623         case SPINOR_OP_READ_FAST:
 624                 break;
 625         default:
 626                 return -EINVAL;
 627         }
 628
 629         while (len > 0) {
 630                 block_size = min_t(size_t, len, INTEL_SPI_FIFO_SZ);
 631
 632                 /* Read cannot cross 4K boundary */
 633                 block_size = min_t(loff_t, from + block_size,
 634                                    round_up(from + 1, SZ_4K)) - from;
 635
 636                 writel(from, ispi->base + FADDR);
 637
 638                 val = readl(ispi->base + HSFSTS_CTL);
 639                 val &= ~(HSFSTS_CTL_FDBC_MASK | HSFSTS_CTL_FCYCLE_MASK);
 640                 val |= HSFSTS_CTL_AEL | HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
 641                 val |= (block_size - 1) << HSFSTS_CTL_FDBC_SHIFT;
 642                 val |= HSFSTS_CTL_FCYCLE_READ;
 643                 val |= HSFSTS_CTL_FGO;
 644                 writel(val, ispi->base + HSFSTS_CTL);
 645
 646                 ret = intel_spi_wait_hw_busy(ispi);
 647                 if (ret)
 648                         return ret;
 649
 650                 status = readl(ispi->base + HSFSTS_CTL);
 651                 if (status & HSFSTS_CTL_FCERR)
 652                         ret = -EIO;
 653                 else if (status & HSFSTS_CTL_AEL)
 654                         ret = -EACCES;
 655
 656                 if (ret < 0) {
 657                         dev_err(ispi->dev, "read error: %llx: %#x\n", from,
 658                                 status);
 659                         return ret;
 660                 }
 661
 662                 ret = intel_spi_read_block(ispi, read_buf, block_size);
 663                 if (ret)
 664                         return ret;
 665
 666                 len -= block_size;
 667                 from += block_size;
 668                 retlen += block_size;
 669                 read_buf += block_size;
 670         }
 671
 672         return retlen;
 673 }
 674
 675 static ssize_t intel_spi_write(struct spi_nor *nor, loff_t to, size_t len,
 676                                const u_char *write_buf)
 677 {
 678         struct intel_spi *ispi = nor->priv;
 679         size_t block_size, retlen = 0;
 680         u32 val, status;
 681         ssize_t ret;
 682
 683         /* Not needed with HW sequencer write, make sure it is cleared */
 684         ispi->atomic_preopcode = 0;
 685
 686         while (len > 0) {
 687                 block_size = min_t(size_t, len, INTEL_SPI_FIFO_SZ);
 688
 689                 /* Write cannot cross 4K boundary */
 690                 block_size = min_t(loff_t, to + block_size,
 691                                    round_up(to + 1, SZ_4K)) - to;
 692
 693                 writel(to, ispi->base + FADDR);
 694
 695                 val = readl(ispi->base + HSFSTS_CTL);
 696                 val &= ~(HSFSTS_CTL_FDBC_MASK | HSFSTS_CTL_FCYCLE_MASK);
 697                 val |= HSFSTS_CTL_AEL | HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
 698                 val |= (block_size - 1) << HSFSTS_CTL_FDBC_SHIFT;
 699                 val |= HSFSTS_CTL_FCYCLE_WRITE;
 700
 701                 ret = intel_spi_write_block(ispi, write_buf, block_size);
 702                 if (ret) {
 703                         dev_err(ispi->dev, "failed to write block\n");
 704                         return ret;
 705                 }
 706
 707                 /* Start the write now */
 708                 val |= HSFSTS_CTL_FGO;
 709                 writel(val, ispi->base + HSFSTS_CTL);
 710
 711                 ret = intel_spi_wait_hw_busy(ispi);
 712                 if (ret) {
 713                         dev_err(ispi->dev, "timeout\n");
 714                         return ret;
 715                 }
 716
 717                 status = readl(ispi->base + HSFSTS_CTL);
 718                 if (status & HSFSTS_CTL_FCERR)
 719                         ret = -EIO;
 720                 else if (status & HSFSTS_CTL_AEL)
 721                         ret = -EACCES;
 722
 723                 if (ret < 0) {
 724                         dev_err(ispi->dev, "write error: %llx: %#x\n", to,
 725                                 status);
 726                         return ret;
 727                 }
 728
 729                 len -= block_size;
 730                 to += block_size;
 731                 retlen += block_size;
 732                 write_buf += block_size;
 733         }
 734
 735         return retlen;
 736 }
 737
 738 static int intel_spi_erase(struct spi_nor *nor, loff_t offs)
 739 {
 740         size_t erase_size, len = nor->mtd.erasesize;
 741         struct intel_spi *ispi = nor->priv;
 742         u32 val, status, cmd;
 743         int ret;
 744
 745         /* If the hardware can do 64k erase use that when possible */
 746         if (len >= SZ_64K && ispi->erase_64k) {
 747                 cmd = HSFSTS_CTL_FCYCLE_ERASE_64K;
 748                 erase_size = SZ_64K;
 749         } else {
 750                 cmd = HSFSTS_CTL_FCYCLE_ERASE;
 751                 erase_size = SZ_4K;
 752         }
 753
 754         if (ispi->swseq_erase) {
 755                 while (len > 0) {
 756                         writel(offs, ispi->base + FADDR);
 757
 758                         ret = intel_spi_sw_cycle(ispi, nor->erase_opcode,
 759                                                  0, OPTYPE_WRITE_WITH_ADDR);
 760                         if (ret)
 761                                 return ret;
 762
 763                         offs += erase_size;
 764                         len -= erase_size;
 765                 }
 766
 767                 return 0;
 768         }
 769
 770         /* Not needed with HW sequencer erase, make sure it is cleared */
 771         ispi->atomic_preopcode = 0;
 772
 773         while (len > 0) {
 774                 writel(offs, ispi->base + FADDR);
 775
 776                 val = readl(ispi->base + HSFSTS_CTL);
 777                 val &= ~(HSFSTS_CTL_FDBC_MASK | HSFSTS_CTL_FCYCLE_MASK);
 778                 val |= HSFSTS_CTL_AEL | HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
 779                 val |= cmd;
 780                 val |= HSFSTS_CTL_FGO;
 781                 writel(val, ispi->base + HSFSTS_CTL);
 782
 783                 ret = intel_spi_wait_hw_busy(ispi);
 784                 if (ret)
 785                         return ret;
 786
 787                 status = readl(ispi->base + HSFSTS_CTL);
 788                 if (status & HSFSTS_CTL_FCERR)
 789                         return -EIO;
 790                 else if (status & HSFSTS_CTL_AEL)
 791                         return -EACCES;
 792
 793                 offs += erase_size;
 794                 len -= erase_size;
 795         }
 796
 797         return 0;
 798 }
 799
 800 static bool intel_spi_is_protected(const struct intel_spi *ispi,
 801                                    unsigned int base, unsigned int limit)
 802 {
 803         int i;
 804
 805         for (i = 0; i < ispi->pr_num; i++) {
 806                 u32 pr_base, pr_limit, pr_value;
 807
 808                 pr_value = readl(ispi->pregs + PR(i));
 809                 if (!(pr_value & (PR_WPE | PR_RPE)))
 810                         continue;
 811
 812                 pr_limit = (pr_value & PR_LIMIT_MASK) >> PR_LIMIT_SHIFT;
 813                 pr_base = pr_value & PR_BASE_MASK;
 814
 815                 if (pr_base >= base && pr_limit <= limit)
 816                         return true;
 817         }
 818
 819         return false;
 820 }
 821
 822 /*
 823  * There will be a single partition holding all enabled flash regions. We
 824  * call this "BIOS".
 825  */
 826 static void intel_spi_fill_partition(struct intel_spi *ispi,
 827                                      struct mtd_partition *part)
 828 {
 829         u64 end;
 830         int i;
 831
 832         memset(part, 0, sizeof(*part));
 833
 834         /* Start from the mandatory descriptor region */
 835         part->size = 4096;
 836         part->name = "BIOS";
 837
 838         /*
 839          * Now try to find where this partition ends based on the flash
 840          * region registers.
 841          */
 842         for (i = 1; i < ispi->nregions; i++) {
 843                 u32 region, base, limit;
 844
 845                 region = readl(ispi->base + FREG(i));
 846                 base = region & FREG_BASE_MASK;
 847                 limit = (region & FREG_LIMIT_MASK) >> FREG_LIMIT_SHIFT;
 848
 849                 if (base >= limit || limit == 0)
 850                         continue;
 851
 852                 /*
 853                  * If any of the regions have protection bits set, make the
 854                  * whole partition read-only to be on the safe side.
 855                  */
 856                 if (intel_spi_is_protected(ispi, base, limit))
 857                         ispi->writeable = false;
 858
 859                 end = (limit << 12) + 4096;
 860                 if (end > part->size)
 861                         part->size = end;
 862         }
 863 }
 864
 865 struct intel_spi *intel_spi_probe(struct device *dev,
 866         struct resource *mem, const struct intel_spi_boardinfo *info)
 867 {
 868         const struct spi_nor_hwcaps hwcaps = {
 869                 .mask = SNOR_HWCAPS_READ |
 870                         SNOR_HWCAPS_READ_FAST |
 871                         SNOR_HWCAPS_PP,
 872         };
 873         struct mtd_partition part;
 874         struct intel_spi *ispi;
 875         int ret;
 876
 877         if (!info || !mem)
 878                 return ERR_PTR(-EINVAL);
 879
 880         ispi = devm_kzalloc(dev, sizeof(*ispi), GFP_KERNEL);
 881         if (!ispi)
 882                 return ERR_PTR(-ENOMEM);
 883
 884         ispi->base = devm_ioremap_resource(dev, mem);
 885         if (IS_ERR(ispi->base))
 886                 return ERR_CAST(ispi->base);
 887
 888         ispi->dev = dev;
 889         ispi->info = info;
 890         ispi->writeable = info->writeable;
 891
 892         ret = intel_spi_init(ispi);
 893         if (ret)
 894                 return ERR_PTR(ret);
 895
 896         ispi->nor.dev = ispi->dev;
 897         ispi->nor.priv = ispi;
 898         ispi->nor.read_reg = intel_spi_read_reg;
 899         ispi->nor.write_reg = intel_spi_write_reg;
 900         ispi->nor.read = intel_spi_read;
 901         ispi->nor.write = intel_spi_write;
 902         ispi->nor.erase = intel_spi_erase;
 903
 904         ret = spi_nor_scan(&ispi->nor, NULL, &hwcaps);
 905         if (ret) {
 906                 dev_info(dev, "failed to locate the chip\n");
 907                 return ERR_PTR(ret);
 908         }
 909
 910         intel_spi_fill_partition(ispi, &part);
 911
 912         /* Prevent writes if not explicitly enabled */
 913         if (!ispi->writeable || !writeable)
 914                 ispi->nor.mtd.flags &= ~MTD_WRITEABLE;
 915
 916         ret = mtd_device_register(&ispi->nor.mtd, &part, 1);
 917         if (ret)
 918                 return ERR_PTR(ret);
 919
 920         return ispi;
 921 }
 922 EXPORT_SYMBOL_GPL(intel_spi_probe);
 923
 924 int intel_spi_remove(struct intel_spi *ispi)
 925 {
 926         return mtd_device_unregister(&ispi->nor.mtd);
 927 }
 928 EXPORT_SYMBOL_GPL(intel_spi_remove);
 929
 930 MODULE_DESCRIPTION("Intel PCH/PCU SPI flash core driver");
 931 MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
 932 MODULE_LICENSE("GPL v2");