uboot/drivers/spi/bfin_spi.c
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   1/*
   2 * Driver for Blackfin On-Chip SPI device
   3 *
   4 * Copyright (c) 2005-2010 Analog Devices Inc.
   5 *
   6 * Licensed under the GPL-2 or later.
   7 */
   8
   9/*#define DEBUG*/
  10
  11#include <common.h>
  12#include <malloc.h>
  13#include <spi.h>
  14
  15#include <asm/blackfin.h>
  16#include <asm/dma.h>
  17#include <asm/gpio.h>
  18#include <asm/portmux.h>
  19#include <asm/mach-common/bits/spi.h>
  20
  21struct bfin_spi_slave {
  22        struct spi_slave slave;
  23        void *mmr_base;
  24        u16 ctl, baud, flg;
  25};
  26
  27#define MAKE_SPI_FUNC(mmr, off) \
  28static inline void write_##mmr(struct bfin_spi_slave *bss, u16 val) { bfin_write16(bss->mmr_base + off, val); } \
  29static inline u16 read_##mmr(struct bfin_spi_slave *bss) { return bfin_read16(bss->mmr_base + off); }
  30MAKE_SPI_FUNC(SPI_CTL,  0x00)
  31MAKE_SPI_FUNC(SPI_FLG,  0x04)
  32MAKE_SPI_FUNC(SPI_STAT, 0x08)
  33MAKE_SPI_FUNC(SPI_TDBR, 0x0c)
  34MAKE_SPI_FUNC(SPI_RDBR, 0x10)
  35MAKE_SPI_FUNC(SPI_BAUD, 0x14)
  36
  37#define to_bfin_spi_slave(s) container_of(s, struct bfin_spi_slave, slave)
  38
  39#define gpio_cs(cs) ((cs) - MAX_CTRL_CS)
  40#ifdef CONFIG_BFIN_SPI_GPIO_CS
  41# define is_gpio_cs(cs) ((cs) > MAX_CTRL_CS)
  42#else
  43# define is_gpio_cs(cs) 0
  44#endif
  45
  46int spi_cs_is_valid(unsigned int bus, unsigned int cs)
  47{
  48        if (is_gpio_cs(cs))
  49                return gpio_is_valid(gpio_cs(cs));
  50        else
  51                return (cs >= 1 && cs <= MAX_CTRL_CS);
  52}
  53
  54void spi_cs_activate(struct spi_slave *slave)
  55{
  56        struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
  57
  58        if (is_gpio_cs(slave->cs)) {
  59                unsigned int cs = gpio_cs(slave->cs);
  60                gpio_set_value(cs, bss->flg);
  61                debug("%s: SPI_CS_GPIO:%x\n", __func__, gpio_get_value(cs));
  62        } else {
  63                write_SPI_FLG(bss,
  64                        (read_SPI_FLG(bss) &
  65                        ~((!bss->flg << 8) << slave->cs)) |
  66                        (1 << slave->cs));
  67                debug("%s: SPI_FLG:%x\n", __func__, read_SPI_FLG(bss));
  68        }
  69
  70        SSYNC();
  71}
  72
  73void spi_cs_deactivate(struct spi_slave *slave)
  74{
  75        struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
  76
  77        if (is_gpio_cs(slave->cs)) {
  78                unsigned int cs = gpio_cs(slave->cs);
  79                gpio_set_value(cs, !bss->flg);
  80                debug("%s: SPI_CS_GPIO:%x\n", __func__, gpio_get_value(cs));
  81        } else {
  82                u16 flg;
  83
  84                /* make sure we force the cs to deassert rather than let the
  85                 * pin float back up.  otherwise, exact timings may not be
  86                 * met some of the time leading to random behavior (ugh).
  87                 */
  88                flg = read_SPI_FLG(bss) | ((!bss->flg << 8) << slave->cs);
  89                write_SPI_FLG(bss, flg);
  90                SSYNC();
  91                debug("%s: SPI_FLG:%x\n", __func__, read_SPI_FLG(bss));
  92
  93                flg &= ~(1 << slave->cs);
  94                write_SPI_FLG(bss, flg);
  95                debug("%s: SPI_FLG:%x\n", __func__, read_SPI_FLG(bss));
  96        }
  97
  98        SSYNC();
  99}
 100
 101void spi_init()
 102{
 103}
 104
 105#ifdef SPI_CTL
 106# define SPI0_CTL SPI_CTL
 107#endif
 108
 109#define SPI_PINS(n) \
 110        [n] = { 0, P_SPI##n##_SCK, P_SPI##n##_MISO, P_SPI##n##_MOSI, 0 }
 111static unsigned short pins[][5] = {
 112#ifdef SPI0_CTL
 113        SPI_PINS(0),
 114#endif
 115#ifdef SPI1_CTL
 116        SPI_PINS(1),
 117#endif
 118#ifdef SPI2_CTL
 119        SPI_PINS(2),
 120#endif
 121};
 122
 123#define SPI_CS_PINS(n) \
 124        [n] = { \
 125                P_SPI##n##_SSEL1, P_SPI##n##_SSEL2, P_SPI##n##_SSEL3, \
 126                P_SPI##n##_SSEL4, P_SPI##n##_SSEL5, P_SPI##n##_SSEL6, \
 127                P_SPI##n##_SSEL7, \
 128        }
 129static const unsigned short cs_pins[][7] = {
 130#ifdef SPI0_CTL
 131        SPI_CS_PINS(0),
 132#endif
 133#ifdef SPI1_CTL
 134        SPI_CS_PINS(1),
 135#endif
 136#ifdef SPI2_CTL
 137        SPI_CS_PINS(2),
 138#endif
 139};
 140
 141void spi_set_speed(struct spi_slave *slave, uint hz)
 142{
 143        struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
 144        ulong sclk;
 145        u32 baud;
 146
 147        sclk = get_sclk();
 148        baud = sclk / (2 * hz);
 149        /* baud should be rounded up */
 150        if (sclk % (2 * hz))
 151                baud += 1;
 152        if (baud < 2)
 153                baud = 2;
 154        else if (baud > (u16)-1)
 155                baud = -1;
 156        bss->baud = baud;
 157}
 158
 159struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
 160                unsigned int max_hz, unsigned int mode)
 161{
 162        struct bfin_spi_slave *bss;
 163        u32 mmr_base;
 164
 165        if (!spi_cs_is_valid(bus, cs))
 166                return NULL;
 167
 168        if (bus >= ARRAY_SIZE(pins) || pins[bus] == NULL) {
 169                debug("%s: invalid bus %u\n", __func__, bus);
 170                return NULL;
 171        }
 172        switch (bus) {
 173#ifdef SPI0_CTL
 174                case 0: mmr_base = SPI0_CTL; break;
 175#endif
 176#ifdef SPI1_CTL
 177                case 1: mmr_base = SPI1_CTL; break;
 178#endif
 179#ifdef SPI2_CTL
 180                case 2: mmr_base = SPI2_CTL; break;
 181#endif
 182                default: return NULL;
 183        }
 184
 185        bss = spi_alloc_slave(struct bfin_spi_slave, bus, cs);
 186        if (!bss)
 187                return NULL;
 188
 189        bss->mmr_base = (void *)mmr_base;
 190        bss->ctl = SPE | MSTR | TDBR_CORE;
 191        if (mode & SPI_CPHA) bss->ctl |= CPHA;
 192        if (mode & SPI_CPOL) bss->ctl |= CPOL;
 193        if (mode & SPI_LSB_FIRST) bss->ctl |= LSBF;
 194        bss->flg = mode & SPI_CS_HIGH ? 1 : 0;
 195        spi_set_speed(&bss->slave, max_hz);
 196
 197        debug("%s: bus:%i cs:%i mmr:%x ctl:%x baud:%i flg:%i\n", __func__,
 198                bus, cs, mmr_base, bss->ctl, bss->baud, bss->flg);
 199
 200        return &bss->slave;
 201}
 202
 203void spi_free_slave(struct spi_slave *slave)
 204{
 205        struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
 206        free(bss);
 207}
 208
 209int spi_claim_bus(struct spi_slave *slave)
 210{
 211        struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
 212
 213        debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
 214
 215        if (is_gpio_cs(slave->cs)) {
 216                unsigned int cs = gpio_cs(slave->cs);
 217                gpio_request(cs, "bfin-spi");
 218                gpio_direction_output(cs, !bss->flg);
 219                pins[slave->bus][0] = P_DONTCARE;
 220        } else
 221                pins[slave->bus][0] = cs_pins[slave->bus][slave->cs - 1];
 222        peripheral_request_list(pins[slave->bus], "bfin-spi");
 223
 224        write_SPI_CTL(bss, bss->ctl);
 225        write_SPI_BAUD(bss, bss->baud);
 226        SSYNC();
 227
 228        return 0;
 229}
 230
 231void spi_release_bus(struct spi_slave *slave)
 232{
 233        struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
 234
 235        debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
 236
 237        peripheral_free_list(pins[slave->bus]);
 238        if (is_gpio_cs(slave->cs))
 239                gpio_free(gpio_cs(slave->cs));
 240
 241        write_SPI_CTL(bss, 0);
 242        SSYNC();
 243}
 244
 245#ifdef __ADSPBF54x__
 246# define SPI_DMA_BASE DMA4_NEXT_DESC_PTR
 247#elif defined(__ADSPBF533__) || defined(__ADSPBF532__) || defined(__ADSPBF531__) || \
 248      defined(__ADSPBF538__) || defined(__ADSPBF539__)
 249# define SPI_DMA_BASE DMA5_NEXT_DESC_PTR
 250#elif defined(__ADSPBF561__)
 251# define SPI_DMA_BASE DMA2_4_NEXT_DESC_PTR
 252#elif defined(__ADSPBF537__) || defined(__ADSPBF536__) || defined(__ADSPBF534__) || \
 253      defined(__ADSPBF52x__) || defined(__ADSPBF51x__)
 254# define SPI_DMA_BASE DMA7_NEXT_DESC_PTR
 255# elif defined(__ADSPBF50x__)
 256# define SPI_DMA_BASE DMA6_NEXT_DESC_PTR
 257#else
 258# error "Please provide SPI DMA channel defines"
 259#endif
 260static volatile struct dma_register *dma = (void *)SPI_DMA_BASE;
 261
 262#ifndef CONFIG_BFIN_SPI_IDLE_VAL
 263# define CONFIG_BFIN_SPI_IDLE_VAL 0xff
 264#endif
 265
 266#ifdef CONFIG_BFIN_SPI_NO_DMA
 267# define SPI_DMA 0
 268#else
 269# define SPI_DMA 1
 270#endif
 271
 272static int spi_dma_xfer(struct bfin_spi_slave *bss, const u8 *tx, u8 *rx,
 273                        uint bytes)
 274{
 275        int ret = -1;
 276        u16 ndsize, spi_config, dma_config;
 277        struct dmasg dmasg[2];
 278        const u8 *buf;
 279
 280        if (tx) {
 281                debug("%s: doing half duplex TX\n", __func__);
 282                buf = tx;
 283                spi_config = TDBR_DMA;
 284                dma_config = 0;
 285        } else {
 286                debug("%s: doing half duplex RX\n", __func__);
 287                buf = rx;
 288                spi_config = RDBR_DMA;
 289                dma_config = WNR;
 290        }
 291
 292        dmasg[0].start_addr = (unsigned long)buf;
 293        dmasg[0].x_modify = 1;
 294        dma_config |= WDSIZE_8 | DMAEN;
 295        if (bytes <= 65536) {
 296                blackfin_dcache_flush_invalidate_range(buf, buf + bytes);
 297                ndsize = NDSIZE_5;
 298                dmasg[0].cfg = NDSIZE_0 | dma_config | FLOW_STOP | DI_EN;
 299                dmasg[0].x_count = bytes;
 300        } else {
 301                blackfin_dcache_flush_invalidate_range(buf, buf + 65536 - 1);
 302                ndsize = NDSIZE_7;
 303                dmasg[0].cfg = NDSIZE_5 | dma_config | FLOW_ARRAY | DMA2D;
 304                dmasg[0].x_count = 0;   /* 2^16 */
 305                dmasg[0].y_count = bytes >> 16; /* count / 2^16 */
 306                dmasg[0].y_modify = 1;
 307                dmasg[1].start_addr = (unsigned long)(buf + (bytes & ~0xFFFF));
 308                dmasg[1].cfg = NDSIZE_0 | dma_config | FLOW_STOP | DI_EN;
 309                dmasg[1].x_count = bytes & 0xFFFF; /* count % 2^16 */
 310                dmasg[1].x_modify = 1;
 311        }
 312
 313        dma->cfg = 0;
 314        dma->irq_status = DMA_DONE | DMA_ERR;
 315        dma->curr_desc_ptr = dmasg;
 316        write_SPI_CTL(bss, (bss->ctl & ~TDBR_CORE));
 317        write_SPI_STAT(bss, -1);
 318        SSYNC();
 319
 320        write_SPI_TDBR(bss, CONFIG_BFIN_SPI_IDLE_VAL);
 321        dma->cfg = ndsize | FLOW_ARRAY | DMAEN;
 322        write_SPI_CTL(bss, (bss->ctl & ~TDBR_CORE) | spi_config);
 323        SSYNC();
 324
 325        /*
 326         * We already invalidated the first 64k,
 327         * now while we just wait invalidate the remaining part.
 328         * Its not likely that the DMA is going to overtake
 329         */
 330        if (bytes > 65536)
 331                blackfin_dcache_flush_invalidate_range(buf + 65536, buf + bytes);
 332
 333        while (!(dma->irq_status & DMA_DONE))
 334                if (ctrlc())
 335                        goto done;
 336
 337        dma->cfg = 0;
 338
 339        ret = 0;
 340 done:
 341        write_SPI_CTL(bss, bss->ctl);
 342        return ret;
 343}
 344
 345static int spi_pio_xfer(struct bfin_spi_slave *bss, const u8 *tx, u8 *rx,
 346                        uint bytes)
 347{
 348        /* todo: take advantage of hardware fifos  */
 349        while (bytes--) {
 350                u8 value = (tx ? *tx++ : CONFIG_BFIN_SPI_IDLE_VAL);
 351                debug("%s: tx:%x ", __func__, value);
 352                write_SPI_TDBR(bss, value);
 353                SSYNC();
 354                while ((read_SPI_STAT(bss) & TXS))
 355                        if (ctrlc())
 356                                return -1;
 357                while (!(read_SPI_STAT(bss) & SPIF))
 358                        if (ctrlc())
 359                                return -1;
 360                while (!(read_SPI_STAT(bss) & RXS))
 361                        if (ctrlc())
 362                                return -1;
 363                value = read_SPI_RDBR(bss);
 364                if (rx)
 365                        *rx++ = value;
 366                debug("rx:%x\n", value);
 367        }
 368
 369        return 0;
 370}
 371
 372int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
 373                void *din, unsigned long flags)
 374{
 375        struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
 376        const u8 *tx = dout;
 377        u8 *rx = din;
 378        uint bytes = bitlen / 8;
 379        int ret = 0;
 380
 381        debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__,
 382                slave->bus, slave->cs, bitlen, bytes, flags);
 383
 384        if (bitlen == 0)
 385                goto done;
 386
 387        /* we can only do 8 bit transfers */
 388        if (bitlen % 8) {
 389                flags |= SPI_XFER_END;
 390                goto done;
 391        }
 392
 393        if (flags & SPI_XFER_BEGIN)
 394                spi_cs_activate(slave);
 395
 396        /* TX DMA doesn't work quite right */
 397        if (SPI_DMA && bytes > 6 && (!tx /*|| !rx*/))
 398                ret = spi_dma_xfer(bss, tx, rx, bytes);
 399        else
 400                ret = spi_pio_xfer(bss, tx, rx, bytes);
 401
 402 done:
 403        if (flags & SPI_XFER_END)
 404                spi_cs_deactivate(slave);
 405
 406        return ret;
 407}
 408