diff options
Diffstat (limited to 'drivers/spi/sandbox_spi.c')
| -rw-r--r-- | drivers/spi/sandbox_spi.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/drivers/spi/sandbox_spi.c b/drivers/spi/sandbox_spi.c new file mode 100644 index 0000000..7895305 --- /dev/null +++ b/drivers/spi/sandbox_spi.c @@ -0,0 +1,204 @@ +/* + * 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; +} |