drivers/spi/bcmstb_spi.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * (C) Copyright 2018  Cisco Systems, Inc.
   4  *
   5  * Author: Thomas Fitzsimmons <fitzsim@fitzsim.org>
   6  */
   7
   8 #include <asm/io.h>
   9 #include <command.h>
  10 #include <config.h>
  11 #include <dm.h>
  12 #include <errno.h>
  13 #include <fdtdec.h>
  14 #include <linux/bitops.h>
  15 #include <linux/delay.h>
  16 #include <log.h>
  17 #include <malloc.h>
  18 #include <spi.h>
  19 #include <time.h>
  20
  21 DECLARE_GLOBAL_DATA_PTR;
  22
  23 #define SPBR_MIN                8
  24 #define BITS_PER_WORD           8
  25
  26 #define NUM_TXRAM               32
  27 #define NUM_RXRAM               32
  28 #define NUM_CDRAM               16
  29
  30 /* hif_mspi register structure. */
  31 struct bcmstb_hif_mspi_regs {
  32         u32 spcr0_lsb;          /* 0x000 */
  33         u32 spcr0_msb;          /* 0x004 */
  34         u32 spcr1_lsb;          /* 0x008 */
  35         u32 spcr1_msb;          /* 0x00c */
  36         u32 newqp;              /* 0x010 */
  37         u32 endqp;              /* 0x014 */
  38         u32 spcr2;              /* 0x018 */
  39         u32 reserved0;          /* 0x01c */
  40         u32 mspi_status;        /* 0x020 */
  41         u32 cptqp;              /* 0x024 */
  42         u32 spcr3;              /* 0x028 */
  43         u32 revision;           /* 0x02c */
  44         u32 reserved1[4];       /* 0x030 */
  45         u32 txram[NUM_TXRAM];   /* 0x040 */
  46         u32 rxram[NUM_RXRAM];   /* 0x0c0 */
  47         u32 cdram[NUM_CDRAM];   /* 0x140 */
  48         u32 write_lock;         /* 0x180 */
  49 };
  50
  51 /* hif_mspi masks. */
  52 #define HIF_MSPI_SPCR2_CONT_AFTER_CMD_MASK      0x00000080
  53 #define HIF_MSPI_SPCR2_SPE_MASK                 0x00000040
  54 #define HIF_MSPI_SPCR2_SPIFIE_MASK              0x00000020
  55 #define HIF_MSPI_WRITE_LOCK_WRITE_LOCK_MASK     0x00000001
  56
  57 /* bspi offsets. */
  58 #define BSPI_MAST_N_BOOT_CTRL                   0x008
  59
  60 /* bspi_raf is not used in this driver. */
  61
  62 /* hif_spi_intr2 offsets and masks. */
  63 #define HIF_SPI_INTR2_CPU_CLEAR                 0x08
  64 #define HIF_SPI_INTR2_CPU_MASK_SET              0x10
  65 #define HIF_SPI_INTR2_CPU_MASK_CLEAR            0x14
  66 #define HIF_SPI_INTR2_CPU_SET_MSPI_DONE_MASK    0x00000020
  67
  68 /* SPI transfer timeout in milliseconds. */
  69 #define HIF_MSPI_WAIT                           10
  70
  71 enum bcmstb_base_type {
  72         HIF_MSPI,
  73         BSPI,
  74         HIF_SPI_INTR2,
  75         CS_REG,
  76         BASE_LAST,
  77 };
  78
  79 struct bcmstb_spi_platdata {
  80         void *base[4];
  81 };
  82
  83 struct bcmstb_spi_priv {
  84         struct bcmstb_hif_mspi_regs *regs;
  85         void *bspi;
  86         void *hif_spi_intr2;
  87         void *cs_reg;
  88         int default_cs;
  89         int curr_cs;
  90         uint tx_slot;
  91         uint rx_slot;
  92         u8 saved_cmd[NUM_CDRAM];
  93         uint saved_cmd_len;
  94         void *saved_din_addr;
  95 };
  96
  97 static int bcmstb_spi_ofdata_to_platdata(struct udevice *bus)
  98 {
  99         struct bcmstb_spi_platdata *plat = dev_get_platdata(bus);
 100         const void *fdt = gd->fdt_blob;
 101         int node = dev_of_offset(bus);
 102         int ret = 0;
 103         int i = 0;
 104         struct fdt_resource resource = { 0 };
 105         char *names[BASE_LAST] = { "hif_mspi", "bspi", "hif_spi_intr2",
 106                                    "cs_reg" };
 107         const phys_addr_t defaults[BASE_LAST] = { BCMSTB_HIF_MSPI_BASE,
 108                                                   BCMSTB_BSPI_BASE,
 109                                                   BCMSTB_HIF_SPI_INTR2,
 110                                                   BCMSTB_CS_REG };
 111
 112         for (i = 0; i < BASE_LAST; i++) {
 113                 plat->base[i] = (void *)defaults[i];
 114
 115                 ret = fdt_get_named_resource(fdt, node, "reg", "reg-names",
 116                                              names[i], &resource);
 117                 if (ret) {
 118                         printf("%s: Assuming BCMSTB SPI %s address 0x0x%p\n",
 119                                __func__, names[i], (void *)defaults[i]);
 120                 } else {
 121                         plat->base[i] = (void *)resource.start;
 122                         debug("BCMSTB SPI %s address: 0x0x%p\n",
 123                               names[i], (void *)plat->base[i]);
 124                 }
 125         }
 126
 127         return 0;
 128 }
 129
 130 static void bcmstb_spi_hw_set_parms(struct bcmstb_spi_priv *priv)
 131 {
 132         writel(SPBR_MIN, &priv->regs->spcr0_lsb);
 133         writel(BITS_PER_WORD << 2 | SPI_MODE_3, &priv->regs->spcr0_msb);
 134 }
 135
 136 static void bcmstb_spi_enable_interrupt(void *base, u32 mask)
 137 {
 138         void *reg = base + HIF_SPI_INTR2_CPU_MASK_CLEAR;
 139
 140         writel(readl(reg) | mask, reg);
 141         readl(reg);
 142 }
 143
 144 static void bcmstb_spi_disable_interrupt(void *base, u32 mask)
 145 {
 146         void *reg = base + HIF_SPI_INTR2_CPU_MASK_SET;
 147
 148         writel(readl(reg) | mask, reg);
 149         readl(reg);
 150 }
 151
 152 static void bcmstb_spi_clear_interrupt(void *base, u32 mask)
 153 {
 154         void *reg = base + HIF_SPI_INTR2_CPU_CLEAR;
 155
 156         writel(readl(reg) | mask, reg);
 157         readl(reg);
 158 }
 159
 160 static int bcmstb_spi_probe(struct udevice *bus)
 161 {
 162         struct bcmstb_spi_platdata *plat = dev_get_platdata(bus);
 163         struct bcmstb_spi_priv *priv = dev_get_priv(bus);
 164
 165         priv->regs = plat->base[HIF_MSPI];
 166         priv->bspi = plat->base[BSPI];
 167         priv->hif_spi_intr2 = plat->base[HIF_SPI_INTR2];
 168         priv->cs_reg = plat->base[CS_REG];
 169         priv->default_cs = 0;
 170         priv->curr_cs = -1;
 171         priv->tx_slot = 0;
 172         priv->rx_slot = 0;
 173         memset(priv->saved_cmd, 0, NUM_CDRAM);
 174         priv->saved_cmd_len = 0;
 175         priv->saved_din_addr = NULL;
 176
 177         debug("spi_xfer: tx regs: 0x%p\n", &priv->regs->txram[0]);
 178         debug("spi_xfer: rx regs: 0x%p\n", &priv->regs->rxram[0]);
 179
 180         /* Disable BSPI. */
 181         writel(1, priv->bspi + BSPI_MAST_N_BOOT_CTRL);
 182         readl(priv->bspi + BSPI_MAST_N_BOOT_CTRL);
 183
 184         /* Set up interrupts. */
 185         bcmstb_spi_disable_interrupt(priv->hif_spi_intr2, 0xffffffff);
 186         bcmstb_spi_clear_interrupt(priv->hif_spi_intr2, 0xffffffff);
 187         bcmstb_spi_enable_interrupt(priv->hif_spi_intr2,
 188                                     HIF_SPI_INTR2_CPU_SET_MSPI_DONE_MASK);
 189
 190         /* Set up control registers. */
 191         writel(0, &priv->regs->spcr1_lsb);
 192         writel(0, &priv->regs->spcr1_msb);
 193         writel(0, &priv->regs->newqp);
 194         writel(0, &priv->regs->endqp);
 195         writel(HIF_MSPI_SPCR2_SPIFIE_MASK, &priv->regs->spcr2);
 196         writel(0, &priv->regs->spcr3);
 197
 198         bcmstb_spi_hw_set_parms(priv);
 199
 200         return 0;
 201 }
 202
 203 static void bcmstb_spi_submit(struct bcmstb_spi_priv *priv, bool done)
 204 {
 205         debug("WR NEWQP: %d\n", 0);
 206         writel(0, &priv->regs->newqp);
 207
 208         debug("WR ENDQP: %d\n", priv->tx_slot - 1);
 209         writel(priv->tx_slot - 1, &priv->regs->endqp);
 210
 211         if (done) {
 212                 debug("WR CDRAM[%d]: %02x\n", priv->tx_slot - 1,
 213                       readl(&priv->regs->cdram[priv->tx_slot - 1]) & ~0x80);
 214                 writel(readl(&priv->regs->cdram[priv->tx_slot - 1]) & ~0x80,
 215                        &priv->regs->cdram[priv->tx_slot - 1]);
 216         }
 217
 218         /* Force chip select first time. */
 219         if (priv->curr_cs != priv->default_cs) {
 220                 debug("spi_xfer: switching chip select to %d\n",
 221                       priv->default_cs);
 222                 writel((readl(priv->cs_reg) & ~0xff) | (1 << priv->default_cs),
 223                        priv->cs_reg);
 224                 readl(priv->cs_reg);
 225                 udelay(10);
 226                 priv->curr_cs = priv->default_cs;
 227         }
 228
 229         debug("WR WRITE_LOCK: %02x\n", 1);
 230         writel((readl(&priv->regs->write_lock) &
 231                 ~HIF_MSPI_WRITE_LOCK_WRITE_LOCK_MASK) | 1,
 232                &priv->regs->write_lock);
 233         readl(&priv->regs->write_lock);
 234
 235         debug("WR SPCR2: %02x\n",
 236               HIF_MSPI_SPCR2_SPIFIE_MASK |
 237               HIF_MSPI_SPCR2_SPE_MASK |
 238               HIF_MSPI_SPCR2_CONT_AFTER_CMD_MASK);
 239         writel(HIF_MSPI_SPCR2_SPIFIE_MASK |
 240                HIF_MSPI_SPCR2_SPE_MASK |
 241                HIF_MSPI_SPCR2_CONT_AFTER_CMD_MASK,
 242                &priv->regs->spcr2);
 243 }
 244
 245 static int bcmstb_spi_wait(struct bcmstb_spi_priv *priv)
 246 {
 247         u32 start_time = get_timer(0);
 248         u32 status = readl(&priv->regs->mspi_status);
 249
 250         while (!(status & 1)) {
 251                 if (get_timer(start_time) > HIF_MSPI_WAIT)
 252                         return -ETIMEDOUT;
 253                 status = readl(&priv->regs->mspi_status);
 254         }
 255
 256         writel(readl(&priv->regs->mspi_status) & ~1, &priv->regs->mspi_status);
 257         bcmstb_spi_clear_interrupt(priv->hif_spi_intr2,
 258                                    HIF_SPI_INTR2_CPU_SET_MSPI_DONE_MASK);
 259
 260         return 0;
 261 }
 262
 263 static int bcmstb_spi_xfer(struct udevice *dev, unsigned int bitlen,
 264                            const void *dout, void *din, unsigned long flags)
 265 {
 266         uint len = bitlen / 8;
 267         uint tx_len = len;
 268         uint rx_len = len;
 269         const u8 *out_bytes = (u8 *)dout;
 270         u8 *in_bytes = (u8 *)din;
 271         struct udevice *bus = dev_get_parent(dev);
 272         struct bcmstb_spi_priv *priv = dev_get_priv(bus);
 273         struct bcmstb_hif_mspi_regs *regs = priv->regs;
 274
 275         debug("spi_xfer: %d, t: 0x%p, r: 0x%p, f: %lx\n",
 276               len, dout, din, flags);
 277         debug("spi_xfer: chip select: %x\n", readl(priv->cs_reg) & 0xff);
 278         debug("spi_xfer: tx addr: 0x%p\n", &regs->txram[0]);
 279         debug("spi_xfer: rx addr: 0x%p\n", &regs->rxram[0]);
 280         debug("spi_xfer: cd addr: 0x%p\n", &regs->cdram[0]);
 281
 282         if (flags & SPI_XFER_END) {
 283                 debug("spi_xfer: clearing saved din address: 0x%p\n",
 284                       priv->saved_din_addr);
 285                 priv->saved_din_addr = NULL;
 286                 priv->saved_cmd_len = 0;
 287                 memset(priv->saved_cmd, 0, NUM_CDRAM);
 288         }
 289
 290         if (bitlen == 0)
 291                 return 0;
 292
 293         if (bitlen % 8) {
 294                 printf("%s: Non-byte-aligned transfer\n", __func__);
 295                 return -EOPNOTSUPP;
 296         }
 297
 298         if (flags & ~(SPI_XFER_BEGIN | SPI_XFER_END)) {
 299                 printf("%s: Unsupported flags: %lx\n", __func__, flags);
 300                 return -EOPNOTSUPP;
 301         }
 302
 303         if (flags & SPI_XFER_BEGIN) {
 304                 priv->tx_slot = 0;
 305                 priv->rx_slot = 0;
 306
 307                 if (out_bytes && len > NUM_CDRAM) {
 308                         printf("%s: Unable to save transfer\n", __func__);
 309                         return -EOPNOTSUPP;
 310                 }
 311
 312                 if (out_bytes && !(flags & SPI_XFER_END)) {
 313                         /*
 314                          * This is the start of a transmit operation
 315                          * that will need repeating if the calling
 316                          * code polls for the result.  Save it for
 317                          * subsequent transmission.
 318                          */
 319                         debug("spi_xfer: saving command: %x, %d\n",
 320                               out_bytes[0], len);
 321                         priv->saved_cmd_len = len;
 322                         memcpy(priv->saved_cmd, out_bytes, priv->saved_cmd_len);
 323                 }
 324         }
 325
 326         if (!(flags & (SPI_XFER_BEGIN | SPI_XFER_END))) {
 327                 if (priv->saved_din_addr == din) {
 328                         /*
 329                          * The caller is polling for status.  Repeat
 330                          * the last transmission.
 331                          */
 332                         int ret = 0;
 333
 334                         debug("spi_xfer: Making recursive call\n");
 335                         ret = bcmstb_spi_xfer(dev, priv->saved_cmd_len * 8,
 336                                               priv->saved_cmd, NULL,
 337                                               SPI_XFER_BEGIN);
 338                         if (ret) {
 339                                 printf("%s: Recursive call failed\n", __func__);
 340                                 return ret;
 341                         }
 342                 } else {
 343                         debug("spi_xfer: saving din address: 0x%p\n", din);
 344                         priv->saved_din_addr = din;
 345                 }
 346         }
 347
 348         while (rx_len > 0) {
 349                 priv->rx_slot = priv->tx_slot;
 350
 351                 while (priv->tx_slot < NUM_CDRAM && tx_len > 0) {
 352                         bcmstb_spi_hw_set_parms(priv);
 353                         debug("WR TXRAM[%d]: %02x\n", priv->tx_slot,
 354                               out_bytes ? out_bytes[len - tx_len] : 0xff);
 355                         writel(out_bytes ? out_bytes[len - tx_len] : 0xff,
 356                                &regs->txram[priv->tx_slot << 1]);
 357                         debug("WR CDRAM[%d]: %02x\n", priv->tx_slot, 0x8e);
 358                         writel(0x8e, &regs->cdram[priv->tx_slot]);
 359                         priv->tx_slot++;
 360                         tx_len--;
 361                         if (!in_bytes)
 362                                 rx_len--;
 363                 }
 364
 365                 debug("spi_xfer: early return clauses: %d, %d, %d\n",
 366                       len <= NUM_CDRAM,
 367                       !in_bytes,
 368                       (flags & (SPI_XFER_BEGIN |
 369                                 SPI_XFER_END)) == SPI_XFER_BEGIN);
 370                 if (len <= NUM_CDRAM &&
 371                     !in_bytes &&
 372                     (flags & (SPI_XFER_BEGIN | SPI_XFER_END)) == SPI_XFER_BEGIN)
 373                         return 0;
 374
 375                 bcmstb_spi_submit(priv, tx_len == 0);
 376
 377                 if (bcmstb_spi_wait(priv) == -ETIMEDOUT) {
 378                         printf("%s: Timed out\n", __func__);
 379                         return -ETIMEDOUT;
 380                 }
 381
 382                 priv->tx_slot %= NUM_CDRAM;
 383
 384                 if (in_bytes) {
 385                         while (priv->rx_slot < NUM_CDRAM && rx_len > 0) {
 386                                 in_bytes[len - rx_len] =
 387                                         readl(&regs->rxram[(priv->rx_slot << 1)
 388                                                            + 1])
 389                                         & 0xff;
 390                                 debug("RD RXRAM[%d]: %02x\n",
 391                                       priv->rx_slot, in_bytes[len - rx_len]);
 392                                 priv->rx_slot++;
 393                                 rx_len--;
 394                         }
 395                 }
 396         }
 397
 398         if (flags & SPI_XFER_END) {
 399                 debug("WR WRITE_LOCK: %02x\n", 0);
 400                 writel((readl(&priv->regs->write_lock) &
 401                         ~HIF_MSPI_WRITE_LOCK_WRITE_LOCK_MASK) | 0,
 402                        &priv->regs->write_lock);
 403                 readl(&priv->regs->write_lock);
 404         }
 405
 406         return 0;
 407 }
 408
 409 static int bcmstb_spi_set_speed(struct udevice *dev, uint speed)
 410 {
 411         return 0;
 412 }
 413
 414 static int bcmstb_spi_set_mode(struct udevice *dev, uint mode)
 415 {
 416         return 0;
 417 }
 418
 419 static const struct dm_spi_ops bcmstb_spi_ops = {
 420         .xfer           = bcmstb_spi_xfer,
 421         .set_speed      = bcmstb_spi_set_speed,
 422         .set_mode       = bcmstb_spi_set_mode,
 423 };
 424
 425 static const struct udevice_id bcmstb_spi_id[] = {
 426         { .compatible = "brcm,spi-brcmstb" },
 427         { }
 428 };
 429
 430 U_BOOT_DRIVER(bcmstb_spi) = {
 431         .name                           = "bcmstb_spi",
 432         .id                             = UCLASS_SPI,
 433         .of_match                       = bcmstb_spi_id,
 434         .ops                            = &bcmstb_spi_ops,
 435         .ofdata_to_platdata             = bcmstb_spi_ofdata_to_platdata,
 436         .probe                          = bcmstb_spi_probe,
 437         .platdata_auto_alloc_size       = sizeof(struct bcmstb_spi_platdata),
 438         .priv_auto_alloc_size           = sizeof(struct bcmstb_spi_priv),
 439 };