drivers/spi/fsl_espi.c

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