LXR uboot/drivers/spi/sandbox

   1/*
   2 * Simulate a SPI port
   3 *
   4 * Copyright (c) 2011-2013 The Chromium OS Authors.
   5 * See file CREDITS for list of people who contributed to this
   6 * project.
   7 *
   8 * Licensed under the GPL-2 or later.
   9 */
  10
  11#include <common.h>
  12#include <dm.h>
  13#include <malloc.h>
  14#include <spi.h>
  15#include <spi_flash.h>
  16#include <os.h>
  17
  18#include <linux/errno.h>
  19#include <asm/spi.h>
  20#include <asm/state.h>
  21#include <dm/device-internal.h>
  22
  23DECLARE_GLOBAL_DATA_PTR;
  24
  25#ifndef CONFIG_SPI_IDLE_VAL
  26# define CONFIG_SPI_IDLE_VAL 0xFF
  27#endif
  28
  29const char *sandbox_spi_parse_spec(const char *arg, unsigned long *bus,
  30                                   unsigned long *cs)
  31{
  32        char *endp;
  33
  34        *bus = simple_strtoul(arg, &endp, 0);
  35        if (*endp != ':' || *bus >= CONFIG_SANDBOX_SPI_MAX_BUS)
  36                return NULL;
  37
  38        *cs = simple_strtoul(endp + 1, &endp, 0);
  39        if (*endp != ':' || *cs >= CONFIG_SANDBOX_SPI_MAX_CS)
  40                return NULL;
  41
  42        return endp + 1;
  43}
  44
  45__weak int sandbox_spi_get_emul(struct sandbox_state *state,
  46                                struct udevice *bus, struct udevice *slave,
  47                                struct udevice **emulp)
  48{
  49        return -ENOENT;
  50}
  51
  52static int sandbox_spi_xfer(struct udevice *slave, unsigned int bitlen,
  53                            const void *dout, void *din, unsigned long flags)
  54{
  55        struct udevice *bus = slave->parent;
  56        struct sandbox_state *state = state_get_current();
  57        struct dm_spi_emul_ops *ops;
  58        struct udevice *emul;
  59        uint bytes = bitlen / 8, i;
  60        int ret;
  61        u8 *tx = (void *)dout, *rx = din;
  62        uint busnum, cs;
  63
  64        if (bitlen == 0)
  65                return 0;
  66
  67        /* we can only do 8 bit transfers */
  68        if (bitlen % 8) {
  69                printf("sandbox_spi: xfer: invalid bitlen size %u; needs to be 8bit\n",
  70                       bitlen);
  71                return -EINVAL;
  72        }
  73
  74        busnum = bus->seq;
  75        cs = spi_chip_select(slave);
  76        if (busnum >= CONFIG_SANDBOX_SPI_MAX_BUS ||
  77            cs >= CONFIG_SANDBOX_SPI_MAX_CS) {
  78                printf("%s: busnum=%u, cs=%u: out of range\n", __func__,
  79                       busnum, cs);
  80                return -ENOENT;
  81        }
  82        ret = sandbox_spi_get_emul(state, bus, slave, &emul);
  83        if (ret) {
  84                printf("%s: busnum=%u, cs=%u: no emulation available (err=%d)\n",
  85                       __func__, busnum, cs, ret);
  86                return -ENOENT;
  87        }
  88        ret = device_probe(emul);
  89        if (ret)
  90                return ret;
  91
  92        /* make sure rx/tx buffers are full so clients can assume */
  93        if (!tx) {
  94                debug("sandbox_spi: xfer: auto-allocating tx scratch buffer\n");
  95                tx = malloc(bytes);
  96                if (!tx) {
  97                        debug("sandbox_spi: Out of memory\n");
  98                        return -ENOMEM;
  99                }
 100        }
 101        if (!rx) {
 102                debug("sandbox_spi: xfer: auto-allocating rx scratch buffer\n");
 103                rx = malloc(bytes);
 104                if (!rx) {
 105                        debug("sandbox_spi: Out of memory\n");
 106                        return -ENOMEM;
 107                }
 108        }
 109
 110        ops = spi_emul_get_ops(emul);
 111        ret = ops->xfer(emul, bitlen, dout, din, flags);
 112
 113        debug("sandbox_spi: xfer: got back %i (that's %s)\n rx:",
 114              ret, ret ? "bad" : "good");
 115        for (i = 0; i < bytes; ++i)
 116                debug(" %u:%02x", i, rx[i]);
 117        debug("\n");
 118
 119        if (tx != dout)
 120                free(tx);
 121        if (rx != din)
 122                free(rx);
 123
 124        return ret;
 125}
 126
 127static int sandbox_spi_set_speed(struct udevice *bus, uint speed)
 128{
 129        return 0;
 130}
 131
 132static int sandbox_spi_set_mode(struct udevice *bus, uint mode)
 133{
 134        return 0;
 135}
 136
 137static int sandbox_cs_info(struct udevice *bus, uint cs,
 138                           struct spi_cs_info *info)
 139{
 140        /* Always allow activity on CS 0 */
 141        if (cs >= 1)
 142                return -ENODEV;
 143
 144        return 0;
 145}
 146
 147static const struct dm_spi_ops sandbox_spi_ops = {
 148        .xfer           = sandbox_spi_xfer,
 149        .set_speed      = sandbox_spi_set_speed,
 150        .set_mode       = sandbox_spi_set_mode,
 151        .cs_info        = sandbox_cs_info,
 152};
 153
 154static const struct udevice_id sandbox_spi_ids[] = {
 155        { .compatible = "sandbox,spi" },
 156        { }
 157};
 158
 159U_BOOT_DRIVER(spi_sandbox) = {
 160        .name   = "spi_sandbox",
 161        .id     = UCLASS_SPI,
 162        .of_match = sandbox_spi_ids,
 163        .ops    = &sandbox_spi_ops,
 164};
 165