u-boot/drivers/spi/sandbox_spi.c

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/*
* Simulate a SPI port
*
* Copyright (c) 2011-2013 The Chromium OS Authors.
* See file CREDITS for list of people who contributed to this
* project.
*
* Licensed under the GPL-2 or later.
*/
#include <common.h>
#include <dm.h>
#include <malloc.h>
#include <spi.h>
#include <spi_flash.h>
#include <os.h>
#include <linux/errno.h>
#include <asm/spi.h>
#include <asm/state.h>
#include <dm/device-internal.h>
DECLARE_GLOBAL_DATA_PTR;
#ifndef CONFIG_SPI_IDLE_VAL
# define CONFIG_SPI_IDLE_VAL 0xFF
#endif
const char *sandbox_spi_parse_spec(const char *arg, unsigned long *bus,
unsigned long *cs)
{
char *endp;
*bus = simple_strtoul(arg, &endp, 0);
if (*endp != ':' || *bus >= CONFIG_SANDBOX_SPI_MAX_BUS)
return NULL;
*cs = simple_strtoul(endp + 1, &endp, 0);
if (*endp != ':' || *cs >= CONFIG_SANDBOX_SPI_MAX_CS)
return NULL;
return endp + 1;
}
__weak int sandbox_spi_get_emul(struct sandbox_state *state,
struct udevice *bus, struct udevice *slave,
struct udevice **emulp)
{
return -ENOENT;
}
static int sandbox_spi_xfer(struct udevice *slave, unsigned int bitlen,
const void *dout, void *din, unsigned long flags)
{
struct udevice *bus = slave->parent;
struct sandbox_state *state = state_get_current();
struct dm_spi_emul_ops *ops;
struct udevice *emul;
uint bytes = bitlen / 8, i;
int ret;
u8 *tx = (void *)dout, *rx = din;
uint busnum, cs;
if (bitlen == 0)
return 0;
/* we can only do 8 bit transfers */
if (bitlen % 8) {
printf("sandbox_spi: xfer: invalid bitlen size %u; needs to be 8bit\n",
bitlen);
return -EINVAL;
}
busnum = bus->seq;
cs = spi_chip_select(slave);
if (busnum >= CONFIG_SANDBOX_SPI_MAX_BUS ||
cs >= CONFIG_SANDBOX_SPI_MAX_CS) {
printf("%s: busnum=%u, cs=%u: out of range\n", __func__,
busnum, cs);
return -ENOENT;
}
ret = sandbox_spi_get_emul(state, bus, slave, &emul);
if (ret) {
printf("%s: busnum=%u, cs=%u: no emulation available (err=%d)\n",
__func__, busnum, cs, ret);
return -ENOENT;
}
ret = device_probe(emul);
if (ret)
return ret;
/* make sure rx/tx buffers are full so clients can assume */
if (!tx) {
debug("sandbox_spi: xfer: auto-allocating tx scratch buffer\n");
tx = malloc(bytes);
if (!tx) {
debug("sandbox_spi: Out of memory\n");
return -ENOMEM;
}
}
if (!rx) {
debug("sandbox_spi: xfer: auto-allocating rx scratch buffer\n");
rx = malloc(bytes);
if (!rx) {
debug("sandbox_spi: Out of memory\n");
return -ENOMEM;
}
}
ops = spi_emul_get_ops(emul);
ret = ops->xfer(emul, bitlen, dout, din, flags);
debug("sandbox_spi: xfer: got back %i (that's %s)\n rx:",
ret, ret ? "bad" : "good");
for (i = 0; i < bytes; ++i)
debug(" %u:%02x", i, rx[i]);
debug("\n");
if (tx != dout)
free(tx);
if (rx != din)
free(rx);
return ret;
}
static int sandbox_spi_set_speed(struct udevice *bus, uint speed)
{
return 0;
}
static int sandbox_spi_set_mode(struct udevice *bus, uint mode)
{
return 0;
}
static int sandbox_cs_info(struct udevice *bus, uint cs,
struct spi_cs_info *info)
{
/* Always allow activity on CS 0 */
if (cs >= 1)
return -ENODEV;
return 0;
}
static const struct dm_spi_ops sandbox_spi_ops = {
.xfer = sandbox_spi_xfer,
.set_speed = sandbox_spi_set_speed,
.set_mode = sandbox_spi_set_mode,
.cs_info = sandbox_cs_info,
};
static const struct udevice_id sandbox_spi_ids[] = {
{ .compatible = "sandbox,spi" },
{ }
};
U_BOOT_DRIVER(spi_sandbox) = {
.name = "spi_sandbox",
.id = UCLASS_SPI,
.of_match = sandbox_spi_ids,
.ops = &sandbox_spi_ops,
};