drivers/spi/cf_spi.c

   1 /*
   2  *
   3  * (C) Copyright 2000-2003
   4  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   5  *
   6  * Copyright (C) 2004-2009 Freescale Semiconductor, Inc.
   7  * TsiChung Liew (Tsi-Chung.Liew@freescale.com)
   8  *
   9  * SPDX-License-Identifier:     GPL-2.0+
  10  */
  11
  12 #include <common.h>
  13 #include <spi.h>
  14 #include <malloc.h>
  15 #include <asm/immap.h>
  16
  17 struct cf_spi_slave {
  18         struct spi_slave slave;
  19         uint baudrate;
  20         int charbit;
  21 };
  22
  23 int cfspi_xfer(struct spi_slave *slave, uint bitlen, const void *dout,
  24                void *din, ulong flags);
  25 struct spi_slave *cfspi_setup_slave(struct cf_spi_slave *cfslave, uint mode);
  26 void cfspi_init(void);
  27 void cfspi_tx(u32 ctrl, u16 data);
  28 u16 cfspi_rx(void);
  29
  30 extern void cfspi_port_conf(void);
  31 extern int cfspi_claim_bus(uint bus, uint cs);
  32 extern void cfspi_release_bus(uint bus, uint cs);
  33
  34 DECLARE_GLOBAL_DATA_PTR;
  35
  36 #ifndef CONFIG_SPI_IDLE_VAL
  37 #if defined(CONFIG_SPI_MMC)
  38 #define CONFIG_SPI_IDLE_VAL     0xFFFF
  39 #else
  40 #define CONFIG_SPI_IDLE_VAL     0x0
  41 #endif
  42 #endif
  43
  44 #if defined(CONFIG_CF_DSPI)
  45 /* DSPI specific mode */
  46 #define SPI_MODE_MOD    0x00200000
  47 #define SPI_DBLRATE     0x00100000
  48
  49 void cfspi_init(void)
  50 {
  51         volatile dspi_t *dspi = (dspi_t *) MMAP_DSPI;
  52
  53         cfspi_port_conf();      /* port configuration */
  54
  55         dspi->mcr = DSPI_MCR_MSTR | DSPI_MCR_CSIS7 | DSPI_MCR_CSIS6 |
  56             DSPI_MCR_CSIS5 | DSPI_MCR_CSIS4 | DSPI_MCR_CSIS3 |
  57             DSPI_MCR_CSIS2 | DSPI_MCR_CSIS1 | DSPI_MCR_CSIS0 |
  58             DSPI_MCR_CRXF | DSPI_MCR_CTXF;
  59
  60         /* Default setting in platform configuration */
  61 #ifdef CONFIG_SYS_DSPI_CTAR0
  62         dspi->ctar[0] = CONFIG_SYS_DSPI_CTAR0;
  63 #endif
  64 #ifdef CONFIG_SYS_DSPI_CTAR1
  65         dspi->ctar[1] = CONFIG_SYS_DSPI_CTAR1;
  66 #endif
  67 #ifdef CONFIG_SYS_DSPI_CTAR2
  68         dspi->ctar[2] = CONFIG_SYS_DSPI_CTAR2;
  69 #endif
  70 #ifdef CONFIG_SYS_DSPI_CTAR3
  71         dspi->ctar[3] = CONFIG_SYS_DSPI_CTAR3;
  72 #endif
  73 #ifdef CONFIG_SYS_DSPI_CTAR4
  74         dspi->ctar[4] = CONFIG_SYS_DSPI_CTAR4;
  75 #endif
  76 #ifdef CONFIG_SYS_DSPI_CTAR5
  77         dspi->ctar[5] = CONFIG_SYS_DSPI_CTAR5;
  78 #endif
  79 #ifdef CONFIG_SYS_DSPI_CTAR6
  80         dspi->ctar[6] = CONFIG_SYS_DSPI_CTAR6;
  81 #endif
  82 #ifdef CONFIG_SYS_DSPI_CTAR7
  83         dspi->ctar[7] = CONFIG_SYS_DSPI_CTAR7;
  84 #endif
  85 }
  86
  87 void cfspi_tx(u32 ctrl, u16 data)
  88 {
  89         volatile dspi_t *dspi = (dspi_t *) MMAP_DSPI;
  90
  91         while ((dspi->sr & 0x0000F000) >= 4) ;
  92
  93         dspi->tfr = (ctrl | data);
  94 }
  95
  96 u16 cfspi_rx(void)
  97 {
  98         volatile dspi_t *dspi = (dspi_t *) MMAP_DSPI;
  99
 100         while ((dspi->sr & 0x000000F0) == 0) ;
 101
 102         return (dspi->rfr & 0xFFFF);
 103 }
 104
 105 int cfspi_xfer(struct spi_slave *slave, uint bitlen, const void *dout,
 106                void *din, ulong flags)
 107 {
 108         struct cf_spi_slave *cfslave = (struct cf_spi_slave *)slave;
 109         u16 *spi_rd16 = NULL, *spi_wr16 = NULL;
 110         u8 *spi_rd = NULL, *spi_wr = NULL;
 111         static u32 ctrl = 0;
 112         uint len = bitlen >> 3;
 113
 114         if (cfslave->charbit == 16) {
 115                 bitlen >>= 1;
 116                 spi_wr16 = (u16 *) dout;
 117                 spi_rd16 = (u16 *) din;
 118         } else {
 119                 spi_wr = (u8 *) dout;
 120                 spi_rd = (u8 *) din;
 121         }
 122
 123         if ((flags & SPI_XFER_BEGIN) == SPI_XFER_BEGIN)
 124                 ctrl |= DSPI_TFR_CONT;
 125
 126         ctrl = (ctrl & 0xFF000000) | ((1 << slave->cs) << 16);
 127
 128         if (len > 1) {
 129                 int tmp_len = len - 1;
 130                 while (tmp_len--) {
 131                         if (dout != NULL) {
 132                                 if (cfslave->charbit == 16)
 133                                         cfspi_tx(ctrl, *spi_wr16++);
 134                                 else
 135                                         cfspi_tx(ctrl, *spi_wr++);
 136                                 cfspi_rx();
 137                         }
 138
 139                         if (din != NULL) {
 140                                 cfspi_tx(ctrl, CONFIG_SPI_IDLE_VAL);
 141                                 if (cfslave->charbit == 16)
 142                                         *spi_rd16++ = cfspi_rx();
 143                                 else
 144                                         *spi_rd++ = cfspi_rx();
 145                         }
 146                 }
 147
 148                 len = 1;        /* remaining byte */
 149         }
 150
 151         if ((flags & SPI_XFER_END) == SPI_XFER_END)
 152                 ctrl &= ~DSPI_TFR_CONT;
 153
 154         if (len) {
 155                 if (dout != NULL) {
 156                         if (cfslave->charbit == 16)
 157                                 cfspi_tx(ctrl, *spi_wr16);
 158                         else
 159                                 cfspi_tx(ctrl, *spi_wr);
 160                         cfspi_rx();
 161                 }
 162
 163                 if (din != NULL) {
 164                         cfspi_tx(ctrl, CONFIG_SPI_IDLE_VAL);
 165                         if (cfslave->charbit == 16)
 166                                 *spi_rd16 = cfspi_rx();
 167                         else
 168                                 *spi_rd = cfspi_rx();
 169                 }
 170         } else {
 171                 /* dummy read */
 172                 cfspi_tx(ctrl, CONFIG_SPI_IDLE_VAL);
 173                 cfspi_rx();
 174         }
 175
 176         return 0;
 177 }
 178
 179 struct spi_slave *cfspi_setup_slave(struct cf_spi_slave *cfslave, uint mode)
 180 {
 181         /*
 182          * bit definition for mode:
 183          * bit 31 - 28: Transfer size 3 to 16 bits
 184          *     27 - 26: PCS to SCK delay prescaler
 185          *     25 - 24: After SCK delay prescaler
 186          *     23 - 22: Delay after transfer prescaler
 187          *     21     : Allow overwrite for bit 31-22 and bit 20-8
 188          *     20     : Double baud rate
 189          *     19 - 16: PCS to SCK delay scaler
 190          *     15 - 12: After SCK delay scaler
 191          *     11 -  8: Delay after transfer scaler
 192          *      7 -  0: SPI_CPHA, SPI_CPOL, SPI_LSB_FIRST
 193          */
 194         volatile dspi_t *dspi = (dspi_t *) MMAP_DSPI;
 195         int prescaler[] = { 2, 3, 5, 7 };
 196         int scaler[] = {
 197                 2, 4, 6, 8,
 198                 16, 32, 64, 128,
 199                 256, 512, 1024, 2048,
 200                 4096, 8192, 16384, 32768
 201         };
 202         int i, j, pbrcnt, brcnt, diff, tmp, dbr = 0;
 203         int best_i, best_j, bestmatch = 0x7FFFFFFF, baud_speed;
 204         u32 bus_setup = 0;
 205
 206         tmp = (prescaler[3] * scaler[15]);
 207         /* Maximum and minimum baudrate it can handle */
 208         if ((cfslave->baudrate > (gd->bus_clk >> 1)) ||
 209             (cfslave->baudrate < (gd->bus_clk / tmp))) {
 210                 printf("Exceed baudrate limitation: Max %d - Min %d\n",
 211                        (int)(gd->bus_clk >> 1), (int)(gd->bus_clk / tmp));
 212                 return NULL;
 213         }
 214
 215         /* Activate Double Baud when it exceed 1/4 the bus clk */
 216         if ((CONFIG_SYS_DSPI_CTAR0 & DSPI_CTAR_DBR) ||
 217             (cfslave->baudrate > (gd->bus_clk / (prescaler[0] * scaler[0])))) {
 218                 bus_setup |= DSPI_CTAR_DBR;
 219                 dbr = 1;
 220         }
 221
 222         if (mode & SPI_CPOL)
 223                 bus_setup |= DSPI_CTAR_CPOL;
 224         if (mode & SPI_CPHA)
 225                 bus_setup |= DSPI_CTAR_CPHA;
 226         if (mode & SPI_LSB_FIRST)
 227                 bus_setup |= DSPI_CTAR_LSBFE;
 228
 229         /* Overwrite default value set in platform configuration file */
 230         if (mode & SPI_MODE_MOD) {
 231
 232                 if ((mode & 0xF0000000) == 0)
 233                         bus_setup |=
 234                             dspi->ctar[cfslave->slave.bus] & 0x78000000;
 235                 else
 236                         bus_setup |= ((mode & 0xF0000000) >> 1);
 237
 238                 /*
 239                  * Check to see if it is enabled by default in platform
 240                  * config, or manual setting passed by mode parameter
 241                  */
 242                 if (mode & SPI_DBLRATE) {
 243                         bus_setup |= DSPI_CTAR_DBR;
 244                         dbr = 1;
 245                 }
 246                 bus_setup |= (mode & 0x0FC00000) >> 4;  /* PSCSCK, PASC, PDT */
 247                 bus_setup |= (mode & 0x000FFF00) >> 4;  /* CSSCK, ASC, DT */
 248         } else
 249                 bus_setup |= (dspi->ctar[cfslave->slave.bus] & 0x78FCFFF0);
 250
 251         cfslave->charbit =
 252             ((dspi->ctar[cfslave->slave.bus] & 0x78000000) ==
 253              0x78000000) ? 16 : 8;
 254
 255         pbrcnt = sizeof(prescaler) / sizeof(int);
 256         brcnt = sizeof(scaler) / sizeof(int);
 257
 258         /* baudrate calculation - to closer value, may not be exact match */
 259         for (best_i = 0, best_j = 0, i = 0; i < pbrcnt; i++) {
 260                 baud_speed = gd->bus_clk / prescaler[i];
 261                 for (j = 0; j < brcnt; j++) {
 262                         tmp = (baud_speed / scaler[j]) * (1 + dbr);
 263
 264                         if (tmp > cfslave->baudrate)
 265                                 diff = tmp - cfslave->baudrate;
 266                         else
 267                                 diff = cfslave->baudrate - tmp;
 268
 269                         if (diff < bestmatch) {
 270                                 bestmatch = diff;
 271                                 best_i = i;
 272                                 best_j = j;
 273                         }
 274                 }
 275         }
 276         bus_setup |= (DSPI_CTAR_PBR(best_i) | DSPI_CTAR_BR(best_j));
 277         dspi->ctar[cfslave->slave.bus] = bus_setup;
 278
 279         return &cfslave->slave;
 280 }
 281 #endif                          /* CONFIG_CF_DSPI */
 282
 283 #ifdef CONFIG_CF_QSPI
 284 /* 52xx, 53xx */
 285 #endif                          /* CONFIG_CF_QSPI */
 286
 287 #ifdef CONFIG_CMD_SPI
 288 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
 289 {
 290         if (((cs >= 0) && (cs < 8)) && ((bus >= 0) && (bus < 8)))
 291                 return 1;
 292         else
 293                 return 0;
 294 }
 295
 296 void spi_init_f(void)
 297 {
 298 }
 299
 300 void spi_init_r(void)
 301 {
 302 }
 303
 304 void spi_init(void)
 305 {
 306         cfspi_init();
 307 }
 308
 309 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
 310                                   unsigned int max_hz, unsigned int mode)
 311 {
 312         struct cf_spi_slave *cfslave;
 313
 314         if (!spi_cs_is_valid(bus, cs))
 315                 return NULL;
 316
 317         cfslave = spi_alloc_slave(struct cf_spi_slave, bus, cs);
 318         if (!cfslave)
 319                 return NULL;
 320
 321         cfslave->baudrate = max_hz;
 322
 323         /* specific setup */
 324         return cfspi_setup_slave(cfslave, mode);
 325 }
 326
 327 void spi_free_slave(struct spi_slave *slave)
 328 {
 329         free(slave);
 330 }
 331
 332 int spi_claim_bus(struct spi_slave *slave)
 333 {
 334         return cfspi_claim_bus(slave->bus, slave->cs);
 335 }
 336
 337 void spi_release_bus(struct spi_slave *slave)
 338 {
 339         cfspi_release_bus(slave->bus, slave->cs);
 340 }
 341
 342 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
 343              void *din, unsigned long flags)
 344 {
 345         return cfspi_xfer(slave, bitlen, dout, din, flags);
 346 }
 347 #endif                          /* CONFIG_CMD_SPI */