Commit 6122813f authored by Mike Frysinger's avatar Mike Frysinger Committed by Simon Glass
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sandbox: spi: Add SPI emulation bus



This adds a SPI framework for people to hook up simulated SPI clients.
Signed-off-by: default avatarMike Frysinger <vapier@gentoo.org>
Signed-off-by: default avatarSimon Glass <sjg@chromium.org>
parent afb6134f
......@@ -9,4 +9,12 @@
#define CONFIG_SANDBOX_ARCH
/* Used by drivers/spi/sandbox_spi.c and arch/sandbox/include/asm/state.h */
#ifndef CONFIG_SANDBOX_SPI_MAX_BUS
#define CONFIG_SANDBOX_SPI_MAX_BUS 1
#endif
#ifndef CONFIG_SANDBOX_SPI_MAX_CS
#define CONFIG_SANDBOX_SPI_MAX_CS 10
#endif
#endif
/*
* Simulate a SPI port and clients (see README.sandbox for details)
*
* 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.
*/
#ifndef __ASM_SPI_H__
#define __ASM_SPI_H__
#include <linux/types.h>
/*
* The interface between the SPI bus and the SPI client. The bus will
* instantiate a client, and that then call into it via these entry
* points. These should be enough for the client to emulate the SPI
* device just like the real hardware.
*/
struct sandbox_spi_emu_ops {
/* The bus wants to instantiate a new client, so setup everything */
int (*setup)(void **priv, const char *spec);
/* The bus is done with us, so break things down */
void (*free)(void *priv);
/* The CS has been "activated" -- we won't worry about low/high */
void (*cs_activate)(void *priv);
/* The CS has been "deactivated" -- we won't worry about low/high */
void (*cs_deactivate)(void *priv);
/* The client is rx-ing bytes from the bus, so it should tx some */
int (*xfer)(void *priv, const u8 *rx, u8 *tx, uint bytes);
};
/*
* There are times when the data lines are allowed to tristate. What
* is actually sensed on the line depends on the hardware. It could
* always be 0xFF/0x00 (if there are pull ups/downs), or things could
* float and so we'd get garbage back. This func encapsulates that
* scenario so we can worry about the details here.
*/
static inline void sandbox_spi_tristate(u8 *buf, uint len)
{
/* XXX: make this into a user config option ? */
memset(buf, 0xff, len);
}
/*
* Extract the bus/cs from the spi spec and return the start of the spi
* client spec. If the bus/cs are invalid for the current config, then
* it returns NULL.
*
* Example: arg="0:1:foo" will set bus to 0, cs to 1, and return "foo"
*/
const char *sandbox_spi_parse_spec(const char *arg, unsigned long *bus,
unsigned long *cs);
#endif
......@@ -15,6 +15,11 @@ enum exit_type_id {
STATE_EXIT_POWER_OFF,
};
struct sandbox_spi_info {
const char *spec;
const struct sandbox_spi_emu_ops *ops;
};
/* The complete state of the test system */
struct sandbox_state {
const char *cmd; /* Command to execute */
......@@ -23,6 +28,10 @@ struct sandbox_state {
const char *parse_err; /* Error to report from parsing */
int argc; /* Program arguments */
char **argv;
/* Pointer to information for each SPI bus/cs */
struct sandbox_spi_info spi[CONFIG_SANDBOX_SPI_MAX_BUS]
[CONFIG_SANDBOX_SPI_MAX_CS];
};
/**
......
......@@ -27,6 +27,7 @@ obj-$(CONFIG_MXC_SPI) += mxc_spi.o
obj-$(CONFIG_MXS_SPI) += mxs_spi.o
obj-$(CONFIG_OC_TINY_SPI) += oc_tiny_spi.o
obj-$(CONFIG_OMAP3_SPI) += omap3_spi.o
obj-$(CONFIG_SANDBOX_SPI) += sandbox_spi.o
obj-$(CONFIG_SOFT_SPI) += soft_spi.o
obj-$(CONFIG_SH_SPI) += sh_spi.o
obj-$(CONFIG_FSL_ESPI) += fsl_espi.o
......
/*
* 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 <malloc.h>
#include <spi.h>
#include <os.h>
#include <asm/errno.h>
#include <asm/spi.h>
#include <asm/state.h>
#ifndef CONFIG_SPI_IDLE_VAL
# define CONFIG_SPI_IDLE_VAL 0xFF
#endif
struct sandbox_spi_slave {
struct spi_slave slave;
const struct sandbox_spi_emu_ops *ops;
void *priv;
};
#define to_sandbox_spi_slave(s) container_of(s, struct sandbox_spi_slave, slave)
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;
}
int spi_cs_is_valid(unsigned int bus, unsigned int cs)
{
return bus < CONFIG_SANDBOX_SPI_MAX_BUS &&
cs < CONFIG_SANDBOX_SPI_MAX_CS;
}
void spi_cs_activate(struct spi_slave *slave)
{
struct sandbox_spi_slave *sss = to_sandbox_spi_slave(slave);
debug("sandbox_spi: activating CS\n");
if (sss->ops->cs_activate)
sss->ops->cs_activate(sss->priv);
}
void spi_cs_deactivate(struct spi_slave *slave)
{
struct sandbox_spi_slave *sss = to_sandbox_spi_slave(slave);
debug("sandbox_spi: deactivating CS\n");
if (sss->ops->cs_deactivate)
sss->ops->cs_deactivate(sss->priv);
}
void spi_init(void)
{
}
void spi_set_speed(struct spi_slave *slave, uint hz)
{
}
struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
unsigned int max_hz, unsigned int mode)
{
struct sandbox_spi_slave *sss;
struct sandbox_state *state = state_get_current();
const char *spec;
if (!spi_cs_is_valid(bus, cs)) {
debug("sandbox_spi: Invalid SPI bus/cs\n");
return NULL;
}
sss = spi_alloc_slave(struct sandbox_spi_slave, bus, cs);
if (!sss) {
debug("sandbox_spi: Out of memory\n");
return NULL;
}
spec = state->spi[bus][cs].spec;
sss->ops = state->spi[bus][cs].ops;
if (!spec || !sss->ops || sss->ops->setup(&sss->priv, spec)) {
free(sss);
printf("sandbox_spi: unable to locate a slave client\n");
return NULL;
}
return &sss->slave;
}
void spi_free_slave(struct spi_slave *slave)
{
struct sandbox_spi_slave *sss = to_sandbox_spi_slave(slave);
debug("sandbox_spi: releasing slave\n");
if (sss->ops->free)
sss->ops->free(sss->priv);
free(sss);
}
static int spi_bus_claim_cnt[CONFIG_SANDBOX_SPI_MAX_BUS];
int spi_claim_bus(struct spi_slave *slave)
{
if (spi_bus_claim_cnt[slave->bus]++) {
printf("sandbox_spi: error: bus already claimed: %d!\n",
spi_bus_claim_cnt[slave->bus]);
}
return 0;
}
void spi_release_bus(struct spi_slave *slave)
{
if (--spi_bus_claim_cnt[slave->bus]) {
printf("sandbox_spi: error: bus freed too often: %d!\n",
spi_bus_claim_cnt[slave->bus]);
}
}
int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
void *din, unsigned long flags)
{
struct sandbox_spi_slave *sss = to_sandbox_spi_slave(slave);
uint bytes = bitlen / 8, i;
int ret = 0;
u8 *tx = (void *)dout, *rx = din;
if (bitlen == 0)
goto done;
/* we can only do 8 bit transfers */
if (bitlen % 8) {
printf("sandbox_spi: xfer: invalid bitlen size %u; needs to be 8bit\n",
bitlen);
flags |= SPI_XFER_END;
goto done;
}
if (flags & SPI_XFER_BEGIN)
spi_cs_activate(slave);
/* 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;
}
}
debug("sandbox_spi: xfer: bytes = %u\n tx:", bytes);
for (i = 0; i < bytes; ++i)
debug(" %u:%02x", i, tx[i]);
debug("\n");
ret = sss->ops->xfer(sss->priv, tx, rx, bytes);
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);
done:
if (flags & SPI_XFER_END)
spi_cs_deactivate(slave);
return ret;
}
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