LXR uboot/drivers/spi/tegra20

   1/*
   2 * Copyright (c) 2010-2013 NVIDIA Corporation
   3 * With help from the mpc8xxx SPI driver
   4 * With more help from omap3_spi SPI driver
   5 *
   6 * SPDX-License-Identifier:     GPL-2.0+
   7 */
   8
   9#include <common.h>
  10#include <dm.h>
  11#include <errno.h>
  12#include <asm/io.h>
  13#include <asm/gpio.h>
  14#include <asm/arch/clock.h>
  15#include <asm/arch/pinmux.h>
  16#include <asm/arch-tegra/clk_rst.h>
  17#include <spi.h>
  18#include <fdtdec.h>
  19#include "tegra_spi.h"
  20
  21DECLARE_GLOBAL_DATA_PTR;
  22
  23#define SPI_CMD_GO                      BIT(30)
  24#define SPI_CMD_ACTIVE_SCLK_SHIFT       26
  25#define SPI_CMD_ACTIVE_SCLK_MASK        (3 << SPI_CMD_ACTIVE_SCLK_SHIFT)
  26#define SPI_CMD_CK_SDA                  BIT(21)
  27#define SPI_CMD_ACTIVE_SDA_SHIFT        18
  28#define SPI_CMD_ACTIVE_SDA_MASK         (3 << SPI_CMD_ACTIVE_SDA_SHIFT)
  29#define SPI_CMD_CS_POL                  BIT(16)
  30#define SPI_CMD_TXEN                    BIT(15)
  31#define SPI_CMD_RXEN                    BIT(14)
  32#define SPI_CMD_CS_VAL                  BIT(13)
  33#define SPI_CMD_CS_SOFT                 BIT(12)
  34#define SPI_CMD_CS_DELAY                BIT(9)
  35#define SPI_CMD_CS3_EN                  BIT(8)
  36#define SPI_CMD_CS2_EN                  BIT(7)
  37#define SPI_CMD_CS1_EN                  BIT(6)
  38#define SPI_CMD_CS0_EN                  BIT(5)
  39#define SPI_CMD_BIT_LENGTH              BIT(4)
  40#define SPI_CMD_BIT_LENGTH_MASK         GENMASK(4, 0)
  41
  42#define SPI_STAT_BSY                    BIT(31)
  43#define SPI_STAT_RDY                    BIT(30)
  44#define SPI_STAT_RXF_FLUSH              BIT(29)
  45#define SPI_STAT_TXF_FLUSH              BIT(28)
  46#define SPI_STAT_RXF_UNR                BIT(27)
  47#define SPI_STAT_TXF_OVF                BIT(26)
  48#define SPI_STAT_RXF_EMPTY              BIT(25)
  49#define SPI_STAT_RXF_FULL               BIT(24)
  50#define SPI_STAT_TXF_EMPTY              BIT(23)
  51#define SPI_STAT_TXF_FULL               BIT(22)
  52#define SPI_STAT_SEL_TXRX_N             BIT(16)
  53#define SPI_STAT_CUR_BLKCNT             BIT(15)
  54
  55#define SPI_TIMEOUT             1000
  56#define TEGRA_SPI_MAX_FREQ      52000000
  57
  58struct spi_regs {
  59        u32 command;    /* SPI_COMMAND_0 register  */
  60        u32 status;     /* SPI_STATUS_0 register */
  61        u32 rx_cmp;     /* SPI_RX_CMP_0 register  */
  62        u32 dma_ctl;    /* SPI_DMA_CTL_0 register */
  63        u32 tx_fifo;    /* SPI_TX_FIFO_0 register */
  64        u32 rsvd[3];    /* offsets 0x14 to 0x1F reserved */
  65        u32 rx_fifo;    /* SPI_RX_FIFO_0 register */
  66};
  67
  68struct tegra20_sflash_priv {
  69        struct spi_regs *regs;
  70        unsigned int freq;
  71        unsigned int mode;
  72        int periph_id;
  73        int valid;
  74        int last_transaction_us;
  75};
  76
  77int tegra20_sflash_cs_info(struct udevice *bus, unsigned int cs,
  78                           struct spi_cs_info *info)
  79{
  80        /* Tegra20 SPI-Flash - only 1 device ('bus/cs') */
  81        if (cs != 0)
  82                return -ENODEV;
  83        else
  84                return 0;
  85}
  86
  87static int tegra20_sflash_ofdata_to_platdata(struct udevice *bus)
  88{
  89        struct tegra_spi_platdata *plat = bus->platdata;
  90        const void *blob = gd->fdt_blob;
  91        int node = bus->of_offset;
  92
  93        plat->base = dev_get_addr(bus);
  94        plat->periph_id = clock_decode_periph_id(blob, node);
  95
  96        if (plat->periph_id == PERIPH_ID_NONE) {
  97                debug("%s: could not decode periph id %d\n", __func__,
  98                      plat->periph_id);
  99                return -FDT_ERR_NOTFOUND;
 100        }
 101
 102        /* Use 500KHz as a suitable default */
 103        plat->frequency = fdtdec_get_int(blob, node, "spi-max-frequency",
 104                                        500000);
 105        plat->deactivate_delay_us = fdtdec_get_int(blob, node,
 106                                        "spi-deactivate-delay", 0);
 107        debug("%s: base=%#08lx, periph_id=%d, max-frequency=%d, deactivate_delay=%d\n",
 108              __func__, plat->base, plat->periph_id, plat->frequency,
 109              plat->deactivate_delay_us);
 110
 111        return 0;
 112}
 113
 114static int tegra20_sflash_probe(struct udevice *bus)
 115{
 116        struct tegra_spi_platdata *plat = dev_get_platdata(bus);
 117        struct tegra20_sflash_priv *priv = dev_get_priv(bus);
 118
 119        priv->regs = (struct spi_regs *)plat->base;
 120
 121        priv->last_transaction_us = timer_get_us();
 122        priv->freq = plat->frequency;
 123        priv->periph_id = plat->periph_id;
 124
 125        return 0;
 126}
 127
 128static int tegra20_sflash_claim_bus(struct udevice *dev)
 129{
 130        struct udevice *bus = dev->parent;
 131        struct tegra20_sflash_priv *priv = dev_get_priv(bus);
 132        struct spi_regs *regs = priv->regs;
 133        u32 reg;
 134
 135        /* Change SPI clock to correct frequency, PLLP_OUT0 source */
 136        clock_start_periph_pll(priv->periph_id, CLOCK_ID_PERIPH,
 137                               priv->freq);
 138
 139        /* Clear stale status here */
 140        reg = SPI_STAT_RDY | SPI_STAT_RXF_FLUSH | SPI_STAT_TXF_FLUSH | \
 141                SPI_STAT_RXF_UNR | SPI_STAT_TXF_OVF;
 142        writel(reg, &regs->status);
 143        debug("%s: STATUS = %08x\n", __func__, readl(&regs->status));
 144
 145        /*
 146         * Use sw-controlled CS, so we can clock in data after ReadID, etc.
 147         */
 148        reg = (priv->mode & 1) << SPI_CMD_ACTIVE_SDA_SHIFT;
 149        if (priv->mode & 2)
 150                reg |= 1 << SPI_CMD_ACTIVE_SCLK_SHIFT;
 151        clrsetbits_le32(&regs->command, SPI_CMD_ACTIVE_SCLK_MASK |
 152                SPI_CMD_ACTIVE_SDA_MASK, SPI_CMD_CS_SOFT | reg);
 153        debug("%s: COMMAND = %08x\n", __func__, readl(&regs->command));
 154
 155        /*
 156         * SPI pins on Tegra20 are muxed - change pinmux later due to UART
 157         * issue.
 158         */
 159        pinmux_set_func(PMUX_PINGRP_GMD, PMUX_FUNC_SFLASH);
 160        pinmux_tristate_disable(PMUX_PINGRP_LSPI);
 161        pinmux_set_func(PMUX_PINGRP_GMC, PMUX_FUNC_SFLASH);
 162
 163        return 0;
 164}
 165
 166static void spi_cs_activate(struct udevice *dev)
 167{
 168        struct udevice *bus = dev->parent;
 169        struct tegra_spi_platdata *pdata = dev_get_platdata(bus);
 170        struct tegra20_sflash_priv *priv = dev_get_priv(bus);
 171
 172        /* If it's too soon to do another transaction, wait */
 173        if (pdata->deactivate_delay_us &&
 174            priv->last_transaction_us) {
 175                ulong delay_us;         /* The delay completed so far */
 176                delay_us = timer_get_us() - priv->last_transaction_us;
 177                if (delay_us < pdata->deactivate_delay_us)
 178                        udelay(pdata->deactivate_delay_us - delay_us);
 179        }
 180
 181        /* CS is negated on Tegra, so drive a 1 to get a 0 */
 182        setbits_le32(&priv->regs->command, SPI_CMD_CS_VAL);
 183}
 184
 185static void spi_cs_deactivate(struct udevice *dev)
 186{
 187        struct udevice *bus = dev->parent;
 188        struct tegra_spi_platdata *pdata = dev_get_platdata(bus);
 189        struct tegra20_sflash_priv *priv = dev_get_priv(bus);
 190
 191        /* CS is negated on Tegra, so drive a 0 to get a 1 */
 192        clrbits_le32(&priv->regs->command, SPI_CMD_CS_VAL);
 193
 194        /* Remember time of this transaction so we can honour the bus delay */
 195        if (pdata->deactivate_delay_us)
 196                priv->last_transaction_us = timer_get_us();
 197}
 198
 199static int tegra20_sflash_xfer(struct udevice *dev, unsigned int bitlen,
 200                             const void *data_out, void *data_in,
 201                             unsigned long flags)
 202{
 203        struct udevice *bus = dev->parent;
 204        struct tegra20_sflash_priv *priv = dev_get_priv(bus);
 205        struct spi_regs *regs = priv->regs;
 206        u32 reg, tmpdout, tmpdin = 0;
 207        const u8 *dout = data_out;
 208        u8 *din = data_in;
 209        int num_bytes;
 210        int ret;
 211
 212        debug("%s: slave %u:%u dout %p din %p bitlen %u\n",
 213              __func__, bus->seq, spi_chip_select(dev), dout, din, bitlen);
 214        if (bitlen % 8)
 215                return -1;
 216        num_bytes = bitlen / 8;
 217
 218        ret = 0;
 219
 220        reg = readl(&regs->status);
 221        writel(reg, &regs->status);     /* Clear all SPI events via R/W */
 222        debug("spi_xfer entry: STATUS = %08x\n", reg);
 223
 224        reg = readl(&regs->command);
 225        reg |= SPI_CMD_TXEN | SPI_CMD_RXEN;
 226        writel(reg, &regs->command);
 227        debug("spi_xfer: COMMAND = %08x\n", readl(&regs->command));
 228
 229        if (flags & SPI_XFER_BEGIN)
 230                spi_cs_activate(dev);
 231
 232        /* handle data in 32-bit chunks */
 233        while (num_bytes > 0) {
 234                int bytes;
 235                int is_read = 0;
 236                int tm, i;
 237
 238                tmpdout = 0;
 239                bytes = (num_bytes > 4) ?  4 : num_bytes;
 240
 241                if (dout != NULL) {
 242                        for (i = 0; i < bytes; ++i)
 243                                tmpdout = (tmpdout << 8) | dout[i];
 244                }
 245
 246                num_bytes -= bytes;
 247                if (dout)
 248                        dout += bytes;
 249
 250                clrsetbits_le32(&regs->command, SPI_CMD_BIT_LENGTH_MASK,
 251                                bytes * 8 - 1);
 252                writel(tmpdout, &regs->tx_fifo);
 253                setbits_le32(&regs->command, SPI_CMD_GO);
 254
 255                /*
 256                 * Wait for SPI transmit FIFO to empty, or to time out.
 257                 * The RX FIFO status will be read and cleared last
 258                 */
 259                for (tm = 0, is_read = 0; tm < SPI_TIMEOUT; ++tm) {
 260                        u32 status;
 261
 262                        status = readl(&regs->status);
 263
 264                        /* We can exit when we've had both RX and TX activity */
 265                        if (is_read && (status & SPI_STAT_TXF_EMPTY))
 266                                break;
 267
 268                        if ((status & (SPI_STAT_BSY | SPI_STAT_RDY)) !=
 269                                        SPI_STAT_RDY)
 270                                tm++;
 271
 272                        else if (!(status & SPI_STAT_RXF_EMPTY)) {
 273                                tmpdin = readl(&regs->rx_fifo);
 274                                is_read = 1;
 275
 276                                /* swap bytes read in */
 277                                if (din != NULL) {
 278                                        for (i = bytes - 1; i >= 0; --i) {
 279                                                din[i] = tmpdin & 0xff;
 280                                                tmpdin >>= 8;
 281                                        }
 282                                        din += bytes;
 283                                }
 284                        }
 285                }
 286
 287                if (tm >= SPI_TIMEOUT)
 288                        ret = tm;
 289
 290                /* clear ACK RDY, etc. bits */
 291                writel(readl(&regs->status), &regs->status);
 292        }
 293
 294        if (flags & SPI_XFER_END)
 295                spi_cs_deactivate(dev);
 296
 297        debug("spi_xfer: transfer ended. Value=%08x, status = %08x\n",
 298                tmpdin, readl(&regs->status));
 299
 300        if (ret) {
 301                printf("spi_xfer: timeout during SPI transfer, tm %d\n", ret);
 302                return -1;
 303        }
 304
 305        return 0;
 306}
 307
 308static int tegra20_sflash_set_speed(struct udevice *bus, uint speed)
 309{
 310        struct tegra_spi_platdata *plat = bus->platdata;
 311        struct tegra20_sflash_priv *priv = dev_get_priv(bus);
 312
 313        if (speed > plat->frequency)
 314                speed = plat->frequency;
 315        priv->freq = speed;
 316        debug("%s: regs=%p, speed=%d\n", __func__, priv->regs, priv->freq);
 317
 318        return 0;
 319}
 320
 321static int tegra20_sflash_set_mode(struct udevice *bus, uint mode)
 322{
 323        struct tegra20_sflash_priv *priv = dev_get_priv(bus);
 324
 325        priv->mode = mode;
 326        debug("%s: regs=%p, mode=%d\n", __func__, priv->regs, priv->mode);
 327
 328        return 0;
 329}
 330
 331static const struct dm_spi_ops tegra20_sflash_ops = {
 332        .claim_bus      = tegra20_sflash_claim_bus,
 333        .xfer           = tegra20_sflash_xfer,
 334        .set_speed      = tegra20_sflash_set_speed,
 335        .set_mode       = tegra20_sflash_set_mode,
 336        .cs_info        = tegra20_sflash_cs_info,
 337};
 338
 339static const struct udevice_id tegra20_sflash_ids[] = {
 340        { .compatible = "nvidia,tegra20-sflash" },
 341        { }
 342};
 343
 344U_BOOT_DRIVER(tegra20_sflash) = {
 345        .name   = "tegra20_sflash",
 346        .id     = UCLASS_SPI,
 347        .of_match = tegra20_sflash_ids,
 348        .ops    = &tegra20_sflash_ops,
 349        .ofdata_to_platdata = tegra20_sflash_ofdata_to_platdata,
 350        .platdata_auto_alloc_size = sizeof(struct tegra_spi_platdata),
 351        .priv_auto_alloc_size = sizeof(struct tegra20_sflash_priv),
 352        .probe  = tegra20_sflash_probe,
 353};
 354