drivers/spi/fsl_espi.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * eSPI controller driver.
   4  *
   5  * Copyright 2010-2011 Freescale Semiconductor, Inc.
   6  * Author: Mingkai Hu (Mingkai.hu@freescale.com)
   7  */
   8
   9 #include <common.h>
  10
  11 #include <malloc.h>
  12 #include <spi.h>
  13 #include <asm/immap_85xx.h>
  14
  15 struct fsl_spi_slave {
  16         struct spi_slave slave;
  17         ccsr_espi_t     *espi;
  18         unsigned int    div16;
  19         unsigned int    pm;
  20         int             tx_timeout;
  21         unsigned int    mode;
  22         size_t          cmd_len;
  23         u8              cmd_buf[16];
  24         size_t          data_len;
  25         unsigned int    max_transfer_length;
  26 };
  27
  28 #define to_fsl_spi_slave(s) container_of(s, struct fsl_spi_slave, slave)
  29 #define US_PER_SECOND           1000000UL
  30
  31 #define ESPI_MAX_CS_NUM         4
  32 #define ESPI_FIFO_WIDTH_BIT     32
  33
  34 #define ESPI_EV_RNE             BIT(9)
  35 #define ESPI_EV_TNF             BIT(8)
  36 #define ESPI_EV_DON             BIT(14)
  37 #define ESPI_EV_TXE             BIT(15)
  38 #define ESPI_EV_RFCNT_SHIFT     24
  39 #define ESPI_EV_RFCNT_MASK      (0x3f << ESPI_EV_RFCNT_SHIFT)
  40
  41 #define ESPI_MODE_EN            BIT(31) /* Enable interface */
  42 #define ESPI_MODE_TXTHR(x)      ((x) << 8)      /* Tx FIFO threshold */
  43 #define ESPI_MODE_RXTHR(x)      ((x) << 0)      /* Rx FIFO threshold */
  44
  45 #define ESPI_COM_CS(x)          ((x) << 30)
  46 #define ESPI_COM_TRANLEN(x)     ((x) << 0)
  47
  48 #define ESPI_CSMODE_CI_INACTIVEHIGH     BIT(31)
  49 #define ESPI_CSMODE_CP_BEGIN_EDGCLK     BIT(30)
  50 #define ESPI_CSMODE_REV_MSB_FIRST       BIT(29)
  51 #define ESPI_CSMODE_DIV16               BIT(28)
  52 #define ESPI_CSMODE_PM(x)               ((x) << 24)
  53 #define ESPI_CSMODE_POL_ASSERTED_LOW    BIT(20)
  54 #define ESPI_CSMODE_LEN(x)              ((x) << 16)
  55 #define ESPI_CSMODE_CSBEF(x)            ((x) << 12)
  56 #define ESPI_CSMODE_CSAFT(x)            ((x) << 8)
  57 #define ESPI_CSMODE_CSCG(x)             ((x) << 3)
  58
  59 #define ESPI_CSMODE_INIT_VAL (ESPI_CSMODE_POL_ASSERTED_LOW | \
  60                 ESPI_CSMODE_CSBEF(0) | ESPI_CSMODE_CSAFT(0) | \
  61                 ESPI_CSMODE_CSCG(1))
  62
  63 #define ESPI_MAX_DATA_TRANSFER_LEN 0xFFF0
  64
  65 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
  66                 unsigned int max_hz, unsigned int mode)
  67 {
  68         struct fsl_spi_slave *fsl;
  69         sys_info_t sysinfo;
  70         unsigned long spibrg = 0;
  71         unsigned long spi_freq = 0;
  72         unsigned char pm = 0;
  73
  74         if (!spi_cs_is_valid(bus, cs))
  75                 return NULL;
  76
  77         fsl = spi_alloc_slave(struct fsl_spi_slave, bus, cs);
  78         if (!fsl)
  79                 return NULL;
  80
  81         fsl->espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR);
  82         fsl->mode = mode;
  83         fsl->max_transfer_length = ESPI_MAX_DATA_TRANSFER_LEN;
  84
  85         /* Set eSPI BRG clock source */
  86         get_sys_info(&sysinfo);
  87         spibrg = sysinfo.freq_systembus / 2;
  88         fsl->div16 = 0;
  89         if ((spibrg / max_hz) > 32) {
  90                 fsl->div16 = ESPI_CSMODE_DIV16;
  91                 pm = spibrg / (max_hz * 16 * 2);
  92                 if (pm > 16) {
  93                         pm = 16;
  94                         debug("Requested speed is too low: %d Hz, %ld Hz "
  95                                 "is used.\n", max_hz, spibrg / (32 * 16));
  96                 }
  97         } else
  98                 pm = spibrg / (max_hz * 2);
  99         if (pm)
 100                 pm--;
 101         fsl->pm = pm;
 102
 103         if (fsl->div16)
 104                 spi_freq = spibrg / ((pm + 1) * 2 * 16);
 105         else
 106                 spi_freq = spibrg / ((pm + 1) * 2);
 107
 108         /* set tx_timeout to 10 times of one espi FIFO entry go out */
 109         fsl->tx_timeout = DIV_ROUND_UP((US_PER_SECOND * ESPI_FIFO_WIDTH_BIT
 110                                 * 10), spi_freq);
 111
 112         return &fsl->slave;
 113 }
 114
 115 void spi_free_slave(struct spi_slave *slave)
 116 {
 117         struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
 118         free(fsl);
 119 }
 120
 121 int spi_claim_bus(struct spi_slave *slave)
 122 {
 123         struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
 124         ccsr_espi_t *espi = fsl->espi;
 125         unsigned char pm = fsl->pm;
 126         unsigned int cs = slave->cs;
 127         unsigned int mode =  fsl->mode;
 128         unsigned int div16 = fsl->div16;
 129         int i;
 130
 131         debug("%s: bus:%i cs:%i\n", __func__, slave->bus, cs);
 132
 133         /* Enable eSPI interface */
 134         out_be32(&espi->mode, ESPI_MODE_RXTHR(3)
 135                         | ESPI_MODE_TXTHR(4) | ESPI_MODE_EN);
 136
 137         out_be32(&espi->event, 0xffffffff); /* Clear all eSPI events */
 138         out_be32(&espi->mask, 0x00000000); /* Mask  all eSPI interrupts */
 139
 140         /* Init CS mode interface */
 141         for (i = 0; i < ESPI_MAX_CS_NUM; i++)
 142                 out_be32(&espi->csmode[i], ESPI_CSMODE_INIT_VAL);
 143
 144         out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs]) &
 145                 ~(ESPI_CSMODE_PM(0xF) | ESPI_CSMODE_DIV16
 146                 | ESPI_CSMODE_CI_INACTIVEHIGH | ESPI_CSMODE_CP_BEGIN_EDGCLK
 147                 | ESPI_CSMODE_REV_MSB_FIRST | ESPI_CSMODE_LEN(0xF)));
 148
 149         /* Set eSPI BRG clock source */
 150         out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
 151                 | ESPI_CSMODE_PM(pm) | div16);
 152
 153         /* Set eSPI mode */
 154         if (mode & SPI_CPHA)
 155                 out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
 156                         | ESPI_CSMODE_CP_BEGIN_EDGCLK);
 157         if (mode & SPI_CPOL)
 158                 out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
 159                         | ESPI_CSMODE_CI_INACTIVEHIGH);
 160
 161         /* Character bit order: msb first */
 162         out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
 163                 | ESPI_CSMODE_REV_MSB_FIRST);
 164
 165         /* Character length in bits, between 0x3~0xf, i.e. 4bits~16bits */
 166         out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
 167                 | ESPI_CSMODE_LEN(7));
 168
 169         return 0;
 170 }
 171
 172 void spi_release_bus(struct spi_slave *slave)
 173 {
 174
 175 }
 176
 177 static void fsl_espi_tx(struct fsl_spi_slave *fsl, const void *dout)
 178 {
 179         ccsr_espi_t *espi = fsl->espi;
 180         unsigned int tmpdout, event;
 181         int tmp_tx_timeout;
 182
 183         if (dout)
 184                 tmpdout = *(u32 *)dout;
 185         else
 186                 tmpdout = 0;
 187
 188         out_be32(&espi->tx, tmpdout);
 189         out_be32(&espi->event, ESPI_EV_TNF);
 190         debug("***spi_xfer:...%08x written\n", tmpdout);
 191
 192         tmp_tx_timeout = fsl->tx_timeout;
 193         /* Wait for eSPI transmit to go out */
 194         while (tmp_tx_timeout--) {
 195                 event = in_be32(&espi->event);
 196                 if (event & ESPI_EV_DON || event & ESPI_EV_TXE) {
 197                         out_be32(&espi->event, ESPI_EV_TXE);
 198                         break;
 199                 }
 200                 udelay(1);
 201         }
 202
 203         if (tmp_tx_timeout < 0)
 204                 debug("***spi_xfer:...Tx timeout! event = %08x\n", event);
 205 }
 206
 207 static int fsl_espi_rx(struct fsl_spi_slave *fsl, void *din, unsigned int bytes)
 208 {
 209         ccsr_espi_t *espi = fsl->espi;
 210         unsigned int tmpdin, rx_times;
 211         unsigned char *buf, *p_cursor;
 212
 213         if (bytes <= 0)
 214                 return 0;
 215
 216         rx_times = DIV_ROUND_UP(bytes, 4);
 217         buf = (unsigned char *)malloc(4 * rx_times);
 218         if (!buf) {
 219                 debug("SF: Failed to malloc memory.\n");
 220                 return -1;
 221         }
 222         p_cursor = buf;
 223         while (rx_times--) {
 224                 tmpdin = in_be32(&espi->rx);
 225                 debug("***spi_xfer:...%08x readed\n", tmpdin);
 226                 *(u32 *)p_cursor = tmpdin;
 227                 p_cursor += 4;
 228         }
 229
 230         if (din)
 231                 memcpy(din, buf, bytes);
 232
 233         free(buf);
 234         out_be32(&espi->event, ESPI_EV_RNE);
 235
 236         return bytes;
 237 }
 238
 239 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *data_out,
 240                 void *data_in, unsigned long flags)
 241 {
 242         struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
 243         ccsr_espi_t *espi = fsl->espi;
 244         unsigned int event, rx_bytes;
 245         const void *dout = NULL;
 246         void *din = NULL;
 247         int len = 0;
 248         int num_blks, num_chunks, max_tran_len, tran_len;
 249         int num_bytes;
 250         unsigned char *buffer = NULL;
 251         size_t buf_len;
 252         u8 *cmd_buf = fsl->cmd_buf;
 253         size_t cmd_len = fsl->cmd_len;
 254         size_t data_len = bitlen / 8;
 255         size_t rx_offset = 0;
 256         int rf_cnt;
 257
 258         max_tran_len = fsl->max_transfer_length;
 259         switch (flags) {
 260         case SPI_XFER_BEGIN:
 261                 cmd_len = fsl->cmd_len = data_len;
 262                 memcpy(cmd_buf, data_out, cmd_len);
 263                 return 0;
 264         case 0:
 265         case SPI_XFER_END:
 266                 if (bitlen == 0) {
 267                         spi_cs_deactivate(slave);
 268                         return 0;
 269                 }
 270                 buf_len = 2 * cmd_len + min(data_len, (size_t)max_tran_len);
 271                 len = cmd_len + data_len;
 272                 rx_offset = cmd_len;
 273                 buffer = (unsigned char *)malloc(buf_len);
 274                 if (!buffer) {
 275                         debug("SF: Failed to malloc memory.\n");
 276                         return 1;
 277                 }
 278                 memcpy(buffer, cmd_buf, cmd_len);
 279                 if (data_in == NULL)
 280                         memcpy(buffer + cmd_len, data_out, data_len);
 281                 break;
 282         case SPI_XFER_BEGIN | SPI_XFER_END:
 283                 len = data_len;
 284                 buffer = (unsigned char *)malloc(len * 2);
 285                 if (!buffer) {
 286                         debug("SF: Failed to malloc memory.\n");
 287                         return 1;
 288                 }
 289                 memcpy(buffer, data_out, len);
 290                 rx_offset = len;
 291                 cmd_len = 0;
 292                 break;
 293         }
 294
 295         debug("spi_xfer: data_out %08X(%p) data_in %08X(%p) len %u\n",
 296               *(uint *)data_out, data_out, *(uint *)data_in, data_in, len);
 297
 298         num_chunks = DIV_ROUND_UP(data_len, max_tran_len);
 299         while (num_chunks--) {
 300                 if (data_in)
 301                         din = buffer + rx_offset;
 302                 dout = buffer;
 303                 tran_len = min(data_len, (size_t)max_tran_len);
 304                 num_blks = DIV_ROUND_UP(tran_len + cmd_len, 4);
 305                 num_bytes = (tran_len + cmd_len) % 4;
 306                 fsl->data_len = tran_len + cmd_len;
 307                 spi_cs_activate(slave);
 308
 309                 /* Clear all eSPI events */
 310                 out_be32(&espi->event , 0xffffffff);
 311                 /* handle data in 32-bit chunks */
 312                 while (num_blks) {
 313                         event = in_be32(&espi->event);
 314                         if (event & ESPI_EV_TNF) {
 315                                 fsl_espi_tx(fsl, dout);
 316                                 /* Set up the next iteration */
 317                                 if (len > 4) {
 318                                         len -= 4;
 319                                         dout += 4;
 320                                 }
 321                         }
 322
 323                         event = in_be32(&espi->event);
 324                         if (event & ESPI_EV_RNE) {
 325                                 rf_cnt = ((event & ESPI_EV_RFCNT_MASK)
 326                                                 >> ESPI_EV_RFCNT_SHIFT);
 327                                 if (rf_cnt >= 4)
 328                                         rx_bytes = 4;
 329                                 else if (num_blks == 1 && rf_cnt == num_bytes)
 330                                         rx_bytes = num_bytes;
 331                                 else
 332                                         continue;
 333                                 if (fsl_espi_rx(fsl, din, rx_bytes)
 334                                                 == rx_bytes) {
 335                                         num_blks--;
 336                                         if (din)
 337                                                 din = (unsigned char *)din
 338                                                         + rx_bytes;
 339                                 }
 340                         }
 341                 }
 342                 if (data_in) {
 343                         memcpy(data_in, buffer + 2 * cmd_len, tran_len);
 344                         if (*buffer == 0x0b) {
 345                                 data_in += tran_len;
 346                                 data_len -= tran_len;
 347                                 *(int *)buffer += tran_len;
 348                         }
 349                 }
 350                 spi_cs_deactivate(slave);
 351         }
 352
 353         free(buffer);
 354         return 0;
 355 }
 356
 357 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
 358 {
 359         return bus == 0 && cs < ESPI_MAX_CS_NUM;
 360 }
 361
 362 void spi_cs_activate(struct spi_slave *slave)
 363 {
 364         struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
 365         ccsr_espi_t *espi = fsl->espi;
 366         unsigned int com = 0;
 367         size_t data_len = fsl->data_len;
 368
 369         com &= ~(ESPI_COM_CS(0x3) | ESPI_COM_TRANLEN(0xFFFF));
 370         com |= ESPI_COM_CS(slave->cs);
 371         com |= ESPI_COM_TRANLEN(data_len - 1);
 372         out_be32(&espi->com, com);
 373 }
 374
 375 void spi_cs_deactivate(struct spi_slave *slave)
 376 {
 377         struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
 378         ccsr_espi_t *espi = fsl->espi;
 379
 380         /* clear the RXCNT and TXCNT */
 381         out_be32(&espi->mode, in_be32(&espi->mode) & (~ESPI_MODE_EN));
 382         out_be32(&espi->mode, in_be32(&espi->mode) | ESPI_MODE_EN);
 383 }