drivers/mtd/spi-nor/atmel-quadspi.c

   1 /*
   2  * Driver for Atmel QSPI Controller
   3  *
   4  * Copyright (C) 2015 Atmel Corporation
   5  *
   6  * Author: Cyrille Pitchen <cyrille.pitchen@atmel.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  15  * more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along with
  18  * this program.  If not, see <http://www.gnu.org/licenses/>.
  19  *
  20  * This driver is based on drivers/mtd/spi-nor/fsl-quadspi.c from Freescale.
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/clk.h>
  25 #include <linux/module.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/delay.h>
  28 #include <linux/err.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/mtd/mtd.h>
  31 #include <linux/mtd/partitions.h>
  32 #include <linux/mtd/spi-nor.h>
  33 #include <linux/platform_data/atmel.h>
  34 #include <linux/of.h>
  35
  36 #include <linux/io.h>
  37 #include <linux/gpio.h>
  38
  39 /* QSPI register offsets */
  40 #define QSPI_CR      0x0000  /* Control Register */
  41 #define QSPI_MR      0x0004  /* Mode Register */
  42 #define QSPI_RD      0x0008  /* Receive Data Register */
  43 #define QSPI_TD      0x000c  /* Transmit Data Register */
  44 #define QSPI_SR      0x0010  /* Status Register */
  45 #define QSPI_IER     0x0014  /* Interrupt Enable Register */
  46 #define QSPI_IDR     0x0018  /* Interrupt Disable Register */
  47 #define QSPI_IMR     0x001c  /* Interrupt Mask Register */
  48 #define QSPI_SCR     0x0020  /* Serial Clock Register */
  49
  50 #define QSPI_IAR     0x0030  /* Instruction Address Register */
  51 #define QSPI_ICR     0x0034  /* Instruction Code Register */
  52 #define QSPI_IFR     0x0038  /* Instruction Frame Register */
  53
  54 #define QSPI_SMR     0x0040  /* Scrambling Mode Register */
  55 #define QSPI_SKR     0x0044  /* Scrambling Key Register */
  56
  57 #define QSPI_WPMR    0x00E4  /* Write Protection Mode Register */
  58 #define QSPI_WPSR    0x00E8  /* Write Protection Status Register */
  59
  60 #define QSPI_VERSION 0x00FC  /* Version Register */
  61
  62
  63 /* Bitfields in QSPI_CR (Control Register) */
  64 #define QSPI_CR_QSPIEN                  BIT(0)
  65 #define QSPI_CR_QSPIDIS                 BIT(1)
  66 #define QSPI_CR_SWRST                   BIT(7)
  67 #define QSPI_CR_LASTXFER                BIT(24)
  68
  69 /* Bitfields in QSPI_MR (Mode Register) */
  70 #define QSPI_MR_SSM                     BIT(0)
  71 #define QSPI_MR_LLB                     BIT(1)
  72 #define QSPI_MR_WDRBT                   BIT(2)
  73 #define QSPI_MR_SMRM                    BIT(3)
  74 #define QSPI_MR_CSMODE_MASK             GENMASK(5, 4)
  75 #define QSPI_MR_CSMODE_NOT_RELOADED     (0 << 4)
  76 #define QSPI_MR_CSMODE_LASTXFER         (1 << 4)
  77 #define QSPI_MR_CSMODE_SYSTEMATICALLY   (2 << 4)
  78 #define QSPI_MR_NBBITS_MASK             GENMASK(11, 8)
  79 #define QSPI_MR_NBBITS(n)               ((((n) - 8) << 8) & QSPI_MR_NBBITS_MASK)
  80 #define QSPI_MR_DLYBCT_MASK             GENMASK(23, 16)
  81 #define QSPI_MR_DLYBCT(n)               (((n) << 16) & QSPI_MR_DLYBCT_MASK)
  82 #define QSPI_MR_DLYCS_MASK              GENMASK(31, 24)
  83 #define QSPI_MR_DLYCS(n)                (((n) << 24) & QSPI_MR_DLYCS_MASK)
  84
  85 /* Bitfields in QSPI_SR/QSPI_IER/QSPI_IDR/QSPI_IMR  */
  86 #define QSPI_SR_RDRF                    BIT(0)
  87 #define QSPI_SR_TDRE                    BIT(1)
  88 #define QSPI_SR_TXEMPTY                 BIT(2)
  89 #define QSPI_SR_OVRES                   BIT(3)
  90 #define QSPI_SR_CSR                     BIT(8)
  91 #define QSPI_SR_CSS                     BIT(9)
  92 #define QSPI_SR_INSTRE                  BIT(10)
  93 #define QSPI_SR_QSPIENS                 BIT(24)
  94
  95 #define QSPI_SR_CMD_COMPLETED   (QSPI_SR_INSTRE | QSPI_SR_CSR)
  96
  97 /* Bitfields in QSPI_SCR (Serial Clock Register) */
  98 #define QSPI_SCR_CPOL                   BIT(0)
  99 #define QSPI_SCR_CPHA                   BIT(1)
 100 #define QSPI_SCR_SCBR_MASK              GENMASK(15, 8)
 101 #define QSPI_SCR_SCBR(n)                (((n) << 8) & QSPI_SCR_SCBR_MASK)
 102 #define QSPI_SCR_DLYBS_MASK             GENMASK(23, 16)
 103 #define QSPI_SCR_DLYBS(n)               (((n) << 16) & QSPI_SCR_DLYBS_MASK)
 104
 105 /* Bitfields in QSPI_ICR (Instruction Code Register) */
 106 #define QSPI_ICR_INST_MASK              GENMASK(7, 0)
 107 #define QSPI_ICR_INST(inst)             (((inst) << 0) & QSPI_ICR_INST_MASK)
 108 #define QSPI_ICR_OPT_MASK               GENMASK(23, 16)
 109 #define QSPI_ICR_OPT(opt)               (((opt) << 16) & QSPI_ICR_OPT_MASK)
 110
 111 /* Bitfields in QSPI_IFR (Instruction Frame Register) */
 112 #define QSPI_IFR_WIDTH_MASK             GENMASK(2, 0)
 113 #define QSPI_IFR_WIDTH_SINGLE_BIT_SPI   (0 << 0)
 114 #define QSPI_IFR_WIDTH_DUAL_OUTPUT      (1 << 0)
 115 #define QSPI_IFR_WIDTH_QUAD_OUTPUT      (2 << 0)
 116 #define QSPI_IFR_WIDTH_DUAL_IO          (3 << 0)
 117 #define QSPI_IFR_WIDTH_QUAD_IO          (4 << 0)
 118 #define QSPI_IFR_WIDTH_DUAL_CMD         (5 << 0)
 119 #define QSPI_IFR_WIDTH_QUAD_CMD         (6 << 0)
 120 #define QSPI_IFR_INSTEN                 BIT(4)
 121 #define QSPI_IFR_ADDREN                 BIT(5)
 122 #define QSPI_IFR_OPTEN                  BIT(6)
 123 #define QSPI_IFR_DATAEN                 BIT(7)
 124 #define QSPI_IFR_OPTL_MASK              GENMASK(9, 8)
 125 #define QSPI_IFR_OPTL_1BIT              (0 << 8)
 126 #define QSPI_IFR_OPTL_2BIT              (1 << 8)
 127 #define QSPI_IFR_OPTL_4BIT              (2 << 8)
 128 #define QSPI_IFR_OPTL_8BIT              (3 << 8)
 129 #define QSPI_IFR_ADDRL                  BIT(10)
 130 #define QSPI_IFR_TFRTYP_MASK            GENMASK(13, 12)
 131 #define QSPI_IFR_TFRTYP_TRSFR_READ      (0 << 12)
 132 #define QSPI_IFR_TFRTYP_TRSFR_READ_MEM  (1 << 12)
 133 #define QSPI_IFR_TFRTYP_TRSFR_WRITE     (2 << 12)
 134 #define QSPI_IFR_TFRTYP_TRSFR_WRITE_MEM (3 << 13)
 135 #define QSPI_IFR_CRM                    BIT(14)
 136 #define QSPI_IFR_NBDUM_MASK             GENMASK(20, 16)
 137 #define QSPI_IFR_NBDUM(n)               (((n) << 16) & QSPI_IFR_NBDUM_MASK)
 138
 139 /* Bitfields in QSPI_SMR (Scrambling Mode Register) */
 140 #define QSPI_SMR_SCREN                  BIT(0)
 141 #define QSPI_SMR_RVDIS                  BIT(1)
 142
 143 /* Bitfields in QSPI_WPMR (Write Protection Mode Register) */
 144 #define QSPI_WPMR_WPEN                  BIT(0)
 145 #define QSPI_WPMR_WPKEY_MASK            GENMASK(31, 8)
 146 #define QSPI_WPMR_WPKEY(wpkey)          (((wpkey) << 8) & QSPI_WPMR_WPKEY_MASK)
 147
 148 /* Bitfields in QSPI_WPSR (Write Protection Status Register) */
 149 #define QSPI_WPSR_WPVS                  BIT(0)
 150 #define QSPI_WPSR_WPVSRC_MASK           GENMASK(15, 8)
 151 #define QSPI_WPSR_WPVSRC(src)           (((src) << 8) & QSPI_WPSR_WPVSRC)
 152
 153
 154 struct atmel_qspi {
 155         void __iomem            *regs;
 156         void __iomem            *mem;
 157         struct clk              *clk;
 158         struct platform_device  *pdev;
 159         u32                     pending;
 160
 161         struct spi_nor          nor;
 162         u32                     clk_rate;
 163         struct completion       cmd_completion;
 164 };
 165
 166 struct atmel_qspi_command {
 167         union {
 168                 struct {
 169                         u32     instruction:1;
 170                         u32     address:3;
 171                         u32     mode:1;
 172                         u32     dummy:1;
 173                         u32     data:1;
 174                         u32     reserved:25;
 175                 }               bits;
 176                 u32     word;
 177         }       enable;
 178         u8      instruction;
 179         u8      mode;
 180         u8      num_mode_cycles;
 181         u8      num_dummy_cycles;
 182         u32     address;
 183
 184         size_t          buf_len;
 185         const void      *tx_buf;
 186         void            *rx_buf;
 187 };
 188
 189 /* Register access functions */
 190 static inline u32 qspi_readl(struct atmel_qspi *aq, u32 reg)
 191 {
 192         return readl_relaxed(aq->regs + reg);
 193 }
 194
 195 static inline void qspi_writel(struct atmel_qspi *aq, u32 reg, u32 value)
 196 {
 197         writel_relaxed(value, aq->regs + reg);
 198 }
 199
 200 static int atmel_qspi_run_transfer(struct atmel_qspi *aq,
 201                                    const struct atmel_qspi_command *cmd)
 202 {
 203         void __iomem *ahb_mem;
 204
 205         /* Then fallback to a PIO transfer (memcpy() DOES NOT work!) */
 206         ahb_mem = aq->mem;
 207         if (cmd->enable.bits.address)
 208                 ahb_mem += cmd->address;
 209         if (cmd->tx_buf)
 210                 _memcpy_toio(ahb_mem, cmd->tx_buf, cmd->buf_len);
 211         else
 212                 _memcpy_fromio(cmd->rx_buf, ahb_mem, cmd->buf_len);
 213
 214         return 0;
 215 }
 216
 217 #ifdef DEBUG
 218 static void atmel_qspi_debug_command(struct atmel_qspi *aq,
 219                                      const struct atmel_qspi_command *cmd,
 220                                      u32 ifr)
 221 {
 222         u8 cmd_buf[SPI_NOR_MAX_CMD_SIZE];
 223         size_t len = 0;
 224         int i;
 225
 226         if (cmd->enable.bits.instruction)
 227                 cmd_buf[len++] = cmd->instruction;
 228
 229         for (i = cmd->enable.bits.address-1; i >= 0; --i)
 230                 cmd_buf[len++] = (cmd->address >> (i << 3)) & 0xff;
 231
 232         if (cmd->enable.bits.mode)
 233                 cmd_buf[len++] = cmd->mode;
 234
 235         if (cmd->enable.bits.dummy) {
 236                 int num = cmd->num_dummy_cycles;
 237
 238                 switch (ifr & QSPI_IFR_WIDTH_MASK) {
 239                 case QSPI_IFR_WIDTH_SINGLE_BIT_SPI:
 240                 case QSPI_IFR_WIDTH_DUAL_OUTPUT:
 241                 case QSPI_IFR_WIDTH_QUAD_OUTPUT:
 242                         num >>= 3;
 243                         break;
 244                 case QSPI_IFR_WIDTH_DUAL_IO:
 245                 case QSPI_IFR_WIDTH_DUAL_CMD:
 246                         num >>= 2;
 247                         break;
 248                 case QSPI_IFR_WIDTH_QUAD_IO:
 249                 case QSPI_IFR_WIDTH_QUAD_CMD:
 250                         num >>= 1;
 251                         break;
 252                 default:
 253                         return;
 254                 }
 255
 256                 for (i = 0; i < num; ++i)
 257                         cmd_buf[len++] = 0;
 258         }
 259
 260         /* Dump the SPI command */
 261         print_hex_dump(KERN_DEBUG, "qspi cmd: ", DUMP_PREFIX_NONE,
 262                        32, 1, cmd_buf, len, false);
 263
 264 #ifdef VERBOSE_DEBUG
 265         /* If verbose debug is enabled, also dump the TX data */
 266         if (cmd->enable.bits.data && cmd->tx_buf)
 267                 print_hex_dump(KERN_DEBUG, "qspi tx : ", DUMP_PREFIX_NONE,
 268                                32, 1, cmd->tx_buf, cmd->buf_len, false);
 269 #endif
 270 }
 271 #else
 272 #define atmel_qspi_debug_command(aq, cmd, ifr)
 273 #endif
 274
 275 static int atmel_qspi_run_command(struct atmel_qspi *aq,
 276                                   const struct atmel_qspi_command *cmd,
 277                                   u32 ifr_tfrtyp, enum spi_nor_protocol proto)
 278 {
 279         u32 iar, icr, ifr, sr;
 280         int err = 0;
 281
 282         iar = 0;
 283         icr = 0;
 284         ifr = ifr_tfrtyp;
 285
 286         /* Set the SPI protocol */
 287         switch (proto) {
 288         case SNOR_PROTO_1_1_1:
 289                 ifr |= QSPI_IFR_WIDTH_SINGLE_BIT_SPI;
 290                 break;
 291
 292         case SNOR_PROTO_1_1_2:
 293                 ifr |= QSPI_IFR_WIDTH_DUAL_OUTPUT;
 294                 break;
 295
 296         case SNOR_PROTO_1_1_4:
 297                 ifr |= QSPI_IFR_WIDTH_QUAD_OUTPUT;
 298                 break;
 299
 300         case SNOR_PROTO_1_2_2:
 301                 ifr |= QSPI_IFR_WIDTH_DUAL_IO;
 302                 break;
 303
 304         case SNOR_PROTO_1_4_4:
 305                 ifr |= QSPI_IFR_WIDTH_QUAD_IO;
 306                 break;
 307
 308         case SNOR_PROTO_2_2_2:
 309                 ifr |= QSPI_IFR_WIDTH_DUAL_CMD;
 310                 break;
 311
 312         case SNOR_PROTO_4_4_4:
 313                 ifr |= QSPI_IFR_WIDTH_QUAD_CMD;
 314                 break;
 315
 316         default:
 317                 return -EINVAL;
 318         }
 319
 320         /* Compute instruction parameters */
 321         if (cmd->enable.bits.instruction) {
 322                 icr |= QSPI_ICR_INST(cmd->instruction);
 323                 ifr |= QSPI_IFR_INSTEN;
 324         }
 325
 326         /* Compute address parameters */
 327         switch (cmd->enable.bits.address) {
 328         case 4:
 329                 ifr |= QSPI_IFR_ADDRL;
 330                 /* fall through to the 24bit (3 byte) address case. */
 331         case 3:
 332                 iar = (cmd->enable.bits.data) ? 0 : cmd->address;
 333                 ifr |= QSPI_IFR_ADDREN;
 334                 break;
 335         case 0:
 336                 break;
 337         default:
 338                 return -EINVAL;
 339         }
 340
 341         /* Compute option parameters */
 342         if (cmd->enable.bits.mode && cmd->num_mode_cycles) {
 343                 u32 mode_cycle_bits, mode_bits;
 344
 345                 icr |= QSPI_ICR_OPT(cmd->mode);
 346                 ifr |= QSPI_IFR_OPTEN;
 347
 348                 switch (ifr & QSPI_IFR_WIDTH_MASK) {
 349                 case QSPI_IFR_WIDTH_SINGLE_BIT_SPI:
 350                 case QSPI_IFR_WIDTH_DUAL_OUTPUT:
 351                 case QSPI_IFR_WIDTH_QUAD_OUTPUT:
 352                         mode_cycle_bits = 1;
 353                         break;
 354                 case QSPI_IFR_WIDTH_DUAL_IO:
 355                 case QSPI_IFR_WIDTH_DUAL_CMD:
 356                         mode_cycle_bits = 2;
 357                         break;
 358                 case QSPI_IFR_WIDTH_QUAD_IO:
 359                 case QSPI_IFR_WIDTH_QUAD_CMD:
 360                         mode_cycle_bits = 4;
 361                         break;
 362                 default:
 363                         return -EINVAL;
 364                 }
 365
 366                 mode_bits = cmd->num_mode_cycles * mode_cycle_bits;
 367                 switch (mode_bits) {
 368                 case 1:
 369                         ifr |= QSPI_IFR_OPTL_1BIT;
 370                         break;
 371
 372                 case 2:
 373                         ifr |= QSPI_IFR_OPTL_2BIT;
 374                         break;
 375
 376                 case 4:
 377                         ifr |= QSPI_IFR_OPTL_4BIT;
 378                         break;
 379
 380                 case 8:
 381                         ifr |= QSPI_IFR_OPTL_8BIT;
 382                         break;
 383
 384                 default:
 385                         return -EINVAL;
 386                 }
 387         }
 388
 389         /* Set number of dummy cycles */
 390         if (cmd->enable.bits.dummy)
 391                 ifr |= QSPI_IFR_NBDUM(cmd->num_dummy_cycles);
 392
 393         /* Set data enable */
 394         if (cmd->enable.bits.data) {
 395                 ifr |= QSPI_IFR_DATAEN;
 396
 397                 /* Special case for Continuous Read Mode */
 398                 if (!cmd->tx_buf && !cmd->rx_buf)
 399                         ifr |= QSPI_IFR_CRM;
 400         }
 401
 402         /* Clear pending interrupts */
 403         (void)qspi_readl(aq, QSPI_SR);
 404
 405         /* Set QSPI Instruction Frame registers */
 406         atmel_qspi_debug_command(aq, cmd, ifr);
 407         qspi_writel(aq, QSPI_IAR, iar);
 408         qspi_writel(aq, QSPI_ICR, icr);
 409         qspi_writel(aq, QSPI_IFR, ifr);
 410
 411         /* Skip to the final steps if there is no data */
 412         if (!cmd->enable.bits.data)
 413                 goto no_data;
 414
 415         /* Dummy read of QSPI_IFR to synchronize APB and AHB accesses */
 416         (void)qspi_readl(aq, QSPI_IFR);
 417
 418         /* Stop here for continuous read */
 419         if (!cmd->tx_buf && !cmd->rx_buf)
 420                 return 0;
 421         /* Send/Receive data */
 422         err = atmel_qspi_run_transfer(aq, cmd);
 423
 424         /* Release the chip-select */
 425         qspi_writel(aq, QSPI_CR, QSPI_CR_LASTXFER);
 426
 427         if (err)
 428                 return err;
 429
 430 #if defined(DEBUG) && defined(VERBOSE_DEBUG)
 431         /*
 432          * If verbose debug is enabled, also dump the RX data in addition to
 433          * the SPI command previously dumped by atmel_qspi_debug_command()
 434          */
 435         if (cmd->rx_buf)
 436                 print_hex_dump(KERN_DEBUG, "qspi rx : ", DUMP_PREFIX_NONE,
 437                                32, 1, cmd->rx_buf, cmd->buf_len, false);
 438 #endif
 439 no_data:
 440         /* Poll INSTRuction End status */
 441         sr = qspi_readl(aq, QSPI_SR);
 442         if ((sr & QSPI_SR_CMD_COMPLETED) == QSPI_SR_CMD_COMPLETED)
 443                 return err;
 444
 445         /* Wait for INSTRuction End interrupt */
 446         reinit_completion(&aq->cmd_completion);
 447         aq->pending = sr & QSPI_SR_CMD_COMPLETED;
 448         qspi_writel(aq, QSPI_IER, QSPI_SR_CMD_COMPLETED);
 449         if (!wait_for_completion_timeout(&aq->cmd_completion,
 450                                          msecs_to_jiffies(1000)))
 451                 err = -ETIMEDOUT;
 452         qspi_writel(aq, QSPI_IDR, QSPI_SR_CMD_COMPLETED);
 453
 454         return err;
 455 }
 456
 457 static int atmel_qspi_read_reg(struct spi_nor *nor, u8 opcode,
 458                                u8 *buf, int len)
 459 {
 460         struct atmel_qspi *aq = nor->priv;
 461         struct atmel_qspi_command cmd;
 462
 463         memset(&cmd, 0, sizeof(cmd));
 464         cmd.enable.bits.instruction = 1;
 465         cmd.enable.bits.data = 1;
 466         cmd.instruction = opcode;
 467         cmd.rx_buf = buf;
 468         cmd.buf_len = len;
 469         return atmel_qspi_run_command(aq, &cmd, QSPI_IFR_TFRTYP_TRSFR_READ,
 470                                       nor->reg_proto);
 471 }
 472
 473 static int atmel_qspi_write_reg(struct spi_nor *nor, u8 opcode,
 474                                 u8 *buf, int len)
 475 {
 476         struct atmel_qspi *aq = nor->priv;
 477         struct atmel_qspi_command cmd;
 478
 479         memset(&cmd, 0, sizeof(cmd));
 480         cmd.enable.bits.instruction = 1;
 481         cmd.enable.bits.data = (buf != NULL && len > 0);
 482         cmd.instruction = opcode;
 483         cmd.tx_buf = buf;
 484         cmd.buf_len = len;
 485         return atmel_qspi_run_command(aq, &cmd, QSPI_IFR_TFRTYP_TRSFR_WRITE,
 486                                       nor->reg_proto);
 487 }
 488
 489 static ssize_t atmel_qspi_write(struct spi_nor *nor, loff_t to, size_t len,
 490                                 const u_char *write_buf)
 491 {
 492         struct atmel_qspi *aq = nor->priv;
 493         struct atmel_qspi_command cmd;
 494         ssize_t ret;
 495
 496         memset(&cmd, 0, sizeof(cmd));
 497         cmd.enable.bits.instruction = 1;
 498         cmd.enable.bits.address = nor->addr_width;
 499         cmd.enable.bits.data = 1;
 500         cmd.instruction = nor->program_opcode;
 501         cmd.address = (u32)to;
 502         cmd.tx_buf = write_buf;
 503         cmd.buf_len = len;
 504         ret = atmel_qspi_run_command(aq, &cmd, QSPI_IFR_TFRTYP_TRSFR_WRITE_MEM,
 505                                      nor->write_proto);
 506         return (ret < 0) ? ret : len;
 507 }
 508
 509 static int atmel_qspi_erase(struct spi_nor *nor, loff_t offs)
 510 {
 511         struct atmel_qspi *aq = nor->priv;
 512         struct atmel_qspi_command cmd;
 513
 514         memset(&cmd, 0, sizeof(cmd));
 515         cmd.enable.bits.instruction = 1;
 516         cmd.enable.bits.address = nor->addr_width;
 517         cmd.instruction = nor->erase_opcode;
 518         cmd.address = (u32)offs;
 519         return atmel_qspi_run_command(aq, &cmd, QSPI_IFR_TFRTYP_TRSFR_WRITE,
 520                                       nor->reg_proto);
 521 }
 522
 523 static ssize_t atmel_qspi_read(struct spi_nor *nor, loff_t from, size_t len,
 524                                u_char *read_buf)
 525 {
 526         struct atmel_qspi *aq = nor->priv;
 527         struct atmel_qspi_command cmd;
 528         u8 num_mode_cycles, num_dummy_cycles;
 529         ssize_t ret;
 530
 531         if (nor->read_dummy >= 2) {
 532                 num_mode_cycles = 2;
 533                 num_dummy_cycles = nor->read_dummy - 2;
 534         } else {
 535                 num_mode_cycles = nor->read_dummy;
 536                 num_dummy_cycles = 0;
 537         }
 538
 539         memset(&cmd, 0, sizeof(cmd));
 540         cmd.enable.bits.instruction = 1;
 541         cmd.enable.bits.address = nor->addr_width;
 542         cmd.enable.bits.mode = (num_mode_cycles > 0);
 543         cmd.enable.bits.dummy = (num_dummy_cycles > 0);
 544         cmd.enable.bits.data = 1;
 545         cmd.instruction = nor->read_opcode;
 546         cmd.address = (u32)from;
 547         cmd.mode = 0xff; /* This value prevents from entering the 0-4-4 mode */
 548         cmd.num_mode_cycles = num_mode_cycles;
 549         cmd.num_dummy_cycles = num_dummy_cycles;
 550         cmd.rx_buf = read_buf;
 551         cmd.buf_len = len;
 552         ret = atmel_qspi_run_command(aq, &cmd, QSPI_IFR_TFRTYP_TRSFR_READ_MEM,
 553                                      nor->read_proto);
 554         return (ret < 0) ? ret : len;
 555 }
 556
 557 static int atmel_qspi_init(struct atmel_qspi *aq)
 558 {
 559         unsigned long src_rate;
 560         u32 mr, scr, scbr;
 561
 562         /* Reset the QSPI controller */
 563         qspi_writel(aq, QSPI_CR, QSPI_CR_SWRST);
 564
 565         /* Set the QSPI controller in Serial Memory Mode */
 566         mr = QSPI_MR_NBBITS(8) | QSPI_MR_SSM;
 567         qspi_writel(aq, QSPI_MR, mr);
 568
 569         src_rate = clk_get_rate(aq->clk);
 570         if (!src_rate)
 571                 return -EINVAL;
 572
 573         /* Compute the QSPI baudrate */
 574         scbr = DIV_ROUND_UP(src_rate, aq->clk_rate);
 575         if (scbr > 0)
 576                 scbr--;
 577         scr = QSPI_SCR_SCBR(scbr);
 578         qspi_writel(aq, QSPI_SCR, scr);
 579
 580         /* Enable the QSPI controller */
 581         qspi_writel(aq, QSPI_CR, QSPI_CR_QSPIEN);
 582
 583         return 0;
 584 }
 585
 586 static irqreturn_t atmel_qspi_interrupt(int irq, void *dev_id)
 587 {
 588         struct atmel_qspi *aq = (struct atmel_qspi *)dev_id;
 589         u32 status, mask, pending;
 590
 591         status = qspi_readl(aq, QSPI_SR);
 592         mask = qspi_readl(aq, QSPI_IMR);
 593         pending = status & mask;
 594
 595         if (!pending)
 596                 return IRQ_NONE;
 597
 598         aq->pending |= pending;
 599         if ((aq->pending & QSPI_SR_CMD_COMPLETED) == QSPI_SR_CMD_COMPLETED)
 600                 complete(&aq->cmd_completion);
 601
 602         return IRQ_HANDLED;
 603 }
 604
 605 static int atmel_qspi_probe(struct platform_device *pdev)
 606 {
 607         const struct spi_nor_hwcaps hwcaps = {
 608                 .mask = SNOR_HWCAPS_READ |
 609                         SNOR_HWCAPS_READ_FAST |
 610                         SNOR_HWCAPS_READ_1_1_2 |
 611                         SNOR_HWCAPS_READ_1_2_2 |
 612                         SNOR_HWCAPS_READ_2_2_2 |
 613                         SNOR_HWCAPS_READ_1_1_4 |
 614                         SNOR_HWCAPS_READ_1_4_4 |
 615                         SNOR_HWCAPS_READ_4_4_4 |
 616                         SNOR_HWCAPS_PP |
 617                         SNOR_HWCAPS_PP_1_1_4 |
 618                         SNOR_HWCAPS_PP_1_4_4 |
 619                         SNOR_HWCAPS_PP_4_4_4,
 620         };
 621         struct device_node *child, *np = pdev->dev.of_node;
 622         struct atmel_qspi *aq;
 623         struct resource *res;
 624         struct spi_nor *nor;
 625         struct mtd_info *mtd;
 626         int irq, err = 0;
 627
 628         if (of_get_child_count(np) != 1)
 629                 return -ENODEV;
 630         child = of_get_next_child(np, NULL);
 631
 632         aq = devm_kzalloc(&pdev->dev, sizeof(*aq), GFP_KERNEL);
 633         if (!aq) {
 634                 err = -ENOMEM;
 635                 goto exit;
 636         }
 637
 638         platform_set_drvdata(pdev, aq);
 639         init_completion(&aq->cmd_completion);
 640         aq->pdev = pdev;
 641
 642         /* Map the registers */
 643         res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi_base");
 644         aq->regs = devm_ioremap_resource(&pdev->dev, res);
 645         if (IS_ERR(aq->regs)) {
 646                 dev_err(&pdev->dev, "missing registers\n");
 647                 err = PTR_ERR(aq->regs);
 648                 goto exit;
 649         }
 650
 651         /* Map the AHB memory */
 652         res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi_mmap");
 653         aq->mem = devm_ioremap_resource(&pdev->dev, res);
 654         if (IS_ERR(aq->mem)) {
 655                 dev_err(&pdev->dev, "missing AHB memory\n");
 656                 err = PTR_ERR(aq->mem);
 657                 goto exit;
 658         }
 659
 660         /* Get the peripheral clock */
 661         aq->clk = devm_clk_get(&pdev->dev, NULL);
 662         if (IS_ERR(aq->clk)) {
 663                 dev_err(&pdev->dev, "missing peripheral clock\n");
 664                 err = PTR_ERR(aq->clk);
 665                 goto exit;
 666         }
 667
 668         /* Enable the peripheral clock */
 669         err = clk_prepare_enable(aq->clk);
 670         if (err) {
 671                 dev_err(&pdev->dev, "failed to enable the peripheral clock\n");
 672                 goto exit;
 673         }
 674
 675         /* Request the IRQ */
 676         irq = platform_get_irq(pdev, 0);
 677         if (irq < 0) {
 678                 dev_err(&pdev->dev, "missing IRQ\n");
 679                 err = irq;
 680                 goto disable_clk;
 681         }
 682         err = devm_request_irq(&pdev->dev, irq, atmel_qspi_interrupt,
 683                                0, dev_name(&pdev->dev), aq);
 684         if (err)
 685                 goto disable_clk;
 686
 687         /* Setup the spi-nor */
 688         nor = &aq->nor;
 689         mtd = &nor->mtd;
 690
 691         nor->dev = &pdev->dev;
 692         spi_nor_set_flash_node(nor, child);
 693         nor->priv = aq;
 694         mtd->priv = nor;
 695
 696         nor->read_reg = atmel_qspi_read_reg;
 697         nor->write_reg = atmel_qspi_write_reg;
 698         nor->read = atmel_qspi_read;
 699         nor->write = atmel_qspi_write;
 700         nor->erase = atmel_qspi_erase;
 701
 702         err = of_property_read_u32(child, "spi-max-frequency", &aq->clk_rate);
 703         if (err < 0)
 704                 goto disable_clk;
 705
 706         err = atmel_qspi_init(aq);
 707         if (err)
 708                 goto disable_clk;
 709
 710         err = spi_nor_scan(nor, NULL, &hwcaps);
 711         if (err)
 712                 goto disable_clk;
 713
 714         err = mtd_device_register(mtd, NULL, 0);
 715         if (err)
 716                 goto disable_clk;
 717
 718         of_node_put(child);
 719
 720         return 0;
 721
 722 disable_clk:
 723         clk_disable_unprepare(aq->clk);
 724 exit:
 725         of_node_put(child);
 726
 727         return err;
 728 }
 729
 730 static int atmel_qspi_remove(struct platform_device *pdev)
 731 {
 732         struct atmel_qspi *aq = platform_get_drvdata(pdev);
 733
 734         mtd_device_unregister(&aq->nor.mtd);
 735         qspi_writel(aq, QSPI_CR, QSPI_CR_QSPIDIS);
 736         clk_disable_unprepare(aq->clk);
 737         return 0;
 738 }
 739
 740
 741 static const struct of_device_id atmel_qspi_dt_ids[] = {
 742         { .compatible = "atmel,sama5d2-qspi" },
 743         { /* sentinel */ }
 744 };
 745
 746 MODULE_DEVICE_TABLE(of, atmel_qspi_dt_ids);
 747
 748 static struct platform_driver atmel_qspi_driver = {
 749         .driver = {
 750                 .name   = "atmel_qspi",
 751                 .of_match_table = atmel_qspi_dt_ids,
 752         },
 753         .probe          = atmel_qspi_probe,
 754         .remove         = atmel_qspi_remove,
 755 };
 756 module_platform_driver(atmel_qspi_driver);
 757
 758 MODULE_AUTHOR("Cyrille Pitchen <cyrille.pitchen@atmel.com>");
 759 MODULE_DESCRIPTION("Atmel QSPI Controller driver");
 760 MODULE_LICENSE("GPL v2");