/**
* @file
*
* @brief Serial Peripheral Interface (SPI) Bus Implementation
*
* @ingroup SPIBus
*/
/*
* Copyright (c) 2016, 2017 embedded brains GmbH. All rights reserved.
*
* embedded brains GmbH
* Dornierstr. 4
* 82178 Puchheim
* Germany
* <rtems@embedded-brains.de>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <dev/spi/spi.h>
#include <rtems/imfs.h>
#include <stdlib.h>
#include <string.h>
static void spi_bus_obtain(spi_bus *bus)
{
rtems_recursive_mutex_lock(&bus->mutex);
}
static void spi_bus_release(spi_bus *bus)
{
rtems_recursive_mutex_unlock(&bus->mutex);
}
static void spi_bus_set_defaults(spi_bus *bus, spi_ioc_transfer *msg)
{
msg->cs_change = bus->cs_change;
msg->cs = bus->cs;
msg->bits_per_word = bus->bits_per_word;
msg->mode = bus->mode;
msg->speed_hz = bus->speed_hz;
msg->delay_usecs = bus->delay_usecs;
}
static ssize_t spi_bus_read(
rtems_libio_t *iop,
void *buffer,
size_t count
)
{
spi_bus *bus = IMFS_generic_get_context_by_iop(iop);
spi_ioc_transfer msg = {
.len = count,
.rx_buf = buffer
};
int err;
spi_bus_obtain(bus);
spi_bus_set_defaults(bus, &msg);
err = (*bus->transfer)(bus, &msg, 1);
spi_bus_release(bus);
if (err == 0) {
return msg.len;
} else {
rtems_set_errno_and_return_minus_one(-err);
}
}
static ssize_t spi_bus_write(
rtems_libio_t *iop,
const void *buffer,
size_t count
)
{
spi_bus *bus = IMFS_generic_get_context_by_iop(iop);
spi_ioc_transfer msg = {
.len = (uint16_t) count,
.tx_buf = buffer
};
int err;
spi_bus_obtain(bus);
spi_bus_set_defaults(bus, &msg);
err = (*bus->transfer)(bus, &msg, 1);
spi_bus_release(bus);
if (err == 0) {
return msg.len;
} else {
rtems_set_errno_and_return_minus_one(-err);
}
}
static int spi_bus_ioctl(
rtems_libio_t *iop,
ioctl_command_t command,
void *arg
)
{
spi_bus *bus = IMFS_generic_get_context_by_iop(iop);
int err;
uint32_t previous;
spi_bus_obtain(bus);
switch (command) {
case SPI_BUS_OBTAIN:
spi_bus_obtain(bus);
err = 0;
break;
case SPI_BUS_RELEASE:
spi_bus_release(bus);
err = 0;
break;
case SPI_IOC_RD_MODE:
*(uint8_t *) arg = bus->mode;
err = 0;
break;
case SPI_IOC_RD_MODE32:
*(uint32_t *) arg = bus->mode;
err = 0;
break;
case SPI_IOC_RD_LSB_FIRST:
*(uint8_t *) arg = bus->lsb_first;
err = 0;
break;
case SPI_IOC_RD_BITS_PER_WORD:
*(uint8_t *) arg = bus->bits_per_word;
err = 0;
break;
case SPI_IOC_RD_MAX_SPEED_HZ:
*(uint32_t *) arg = bus->speed_hz;
err = 0;
break;
case SPI_IOC_WR_MODE:
previous = bus->mode;
bus->mode = *(uint8_t *) arg;
err = (*bus->setup)(bus);
if (err != 0) {
bus->mode = previous;
}
break;
case SPI_IOC_WR_MODE32:
previous = bus->mode;
bus->mode = *(uint32_t *) arg;
err = (*bus->setup)(bus);
if (err != 0) {
bus->mode = previous;
}
break;
case SPI_IOC_WR_LSB_FIRST:
previous = bus->lsb_first;
bus->lsb_first = (*(uint8_t *) arg) != 0;
err = (*bus->setup)(bus);
if (err != 0) {
bus->lsb_first = (bool) previous;
}
break;
case SPI_IOC_WR_BITS_PER_WORD:
previous = bus->bits_per_word;
bus->bits_per_word = *(uint8_t *) arg;
err = (*bus->setup)(bus);
if (err != 0) {
bus->bits_per_word = (uint8_t) previous;
}
break;
case SPI_IOC_WR_MAX_SPEED_HZ:
previous = bus->speed_hz;
bus->speed_hz = *(uint32_t *) arg;
err = (*bus->setup)(bus);
if (err != 0) {
bus->speed_hz = previous;
}
break;
default:
if (IOCBASECMD(command) == IOCBASECMD(_IOW(SPI_IOC_MAGIC, 0, 0))) {
err = (*bus->transfer)(
bus,
arg,
IOCPARM_LEN(command) / sizeof(struct spi_ioc_transfer)
);
} else {
err = -EINVAL;
}
break;
}
spi_bus_release(bus);
if (err == 0) {
return 0;
} else {
rtems_set_errno_and_return_minus_one(-err);
}
}
static const rtems_filesystem_file_handlers_r spi_bus_handler = {
.open_h = rtems_filesystem_default_open,
.close_h = rtems_filesystem_default_close,
.read_h = spi_bus_read,
.write_h = spi_bus_write,
.ioctl_h = spi_bus_ioctl,
.lseek_h = rtems_filesystem_default_lseek,
.fstat_h = IMFS_stat,
.ftruncate_h = rtems_filesystem_default_ftruncate,
.fsync_h = rtems_filesystem_default_fsync_or_fdatasync,
.fdatasync_h = rtems_filesystem_default_fsync_or_fdatasync,
.fcntl_h = rtems_filesystem_default_fcntl,
.kqfilter_h = rtems_filesystem_default_kqfilter,
.mmap_h = rtems_filesystem_default_mmap,
.poll_h = rtems_filesystem_default_poll,
.readv_h = rtems_filesystem_default_readv,
.writev_h = rtems_filesystem_default_writev
};
static void spi_bus_node_destroy(IMFS_jnode_t *node)
{
spi_bus *bus;
bus = IMFS_generic_get_context_by_node(node);
(*bus->destroy)(bus);
IMFS_node_destroy_default(node);
}
static const IMFS_node_control spi_bus_node_control = IMFS_GENERIC_INITIALIZER(
&spi_bus_handler,
IMFS_node_initialize_generic,
spi_bus_node_destroy
);
int spi_bus_register(
spi_bus *bus,
const char *bus_path
)
{
int rv;
rv = IMFS_make_generic_node(
bus_path,
S_IFCHR | S_IRWXU | S_IRWXG | S_IRWXO,
&spi_bus_node_control,
bus
);
if (rv != 0) {
(*bus->destroy)(bus);
}
return rv;
}
static int spi_bus_transfer_default(
spi_bus *bus,
const spi_ioc_transfer *msgs,
uint32_t msg_count
)
{
(void) bus;
(void) msgs;
(void) msg_count;
return -EIO;
}
static int spi_bus_setup_default(
spi_bus *bus
)
{
(void) bus;
return -EIO;
}
static int spi_bus_do_init(
spi_bus *bus,
void (*destroy)(spi_bus *bus)
)
{
rtems_recursive_mutex_init(&bus->mutex, "SPI Bus");
bus->transfer = spi_bus_transfer_default;
bus->setup = spi_bus_setup_default;
bus->destroy = destroy;
bus->bits_per_word = 8;
return 0;
}
void spi_bus_destroy(spi_bus *bus)
{
rtems_recursive_mutex_destroy(&bus->mutex);
}
void spi_bus_destroy_and_free(spi_bus *bus)
{
spi_bus_destroy(bus);
free(bus);
}
int spi_bus_init(spi_bus *bus)
{
memset(bus, 0, sizeof(*bus));
return spi_bus_do_init(bus, spi_bus_destroy);
}
spi_bus *spi_bus_alloc_and_init(size_t size)
{
spi_bus *bus = NULL;
if (size >= sizeof(*bus)) {
bus = calloc(1, size);
if (bus != NULL) {
int rv;
rv = spi_bus_do_init(bus, spi_bus_destroy_and_free);
if (rv != 0) {
return NULL;
}
}
}
return bus;
}