lss.c

Go to the documentation of this file.

#include "co.h"

#ifndef LELY_NO_CO_LSS

#include <lely/co/lss.h>
#include <lely/co/nmt.h>
#include <lely/co/obj.h>
#include <lely/co/val.h>
#include <lely/util/endian.h>
#include <lely/util/errnum.h>

#include <assert.h>
#include <stdlib.h>

struct __co_lss_state;
typedef const struct __co_lss_state co_lss_state_t;

struct __co_lss {
        co_nmt_t *nmt;
        can_net_t *net;
        co_dev_t *dev;
        co_lss_state_t *state;
#ifndef LELY_NO_CO_MASTER
        int master;
#endif
        can_recv_t *recv;
#ifndef LELY_NO_CO_MASTER
        int timeout;
        can_timer_t *timer;
#endif
        co_unsigned8_t cs;
        co_unsigned8_t lsspos;
#ifndef LELY_NO_CO_MASTER
        struct co_id lo;
        struct co_id hi;
        struct co_id mask;
        co_unsigned8_t bitchk;
        co_unsigned8_t lsssub;
        co_unsigned8_t err;
        co_unsigned8_t spec;
        co_unsigned32_t lssid;
        co_unsigned8_t nid;
        struct co_id id;
#endif
        co_lss_rate_ind_t *rate_ind;
        void *rate_data;
        co_lss_store_ind_t *store_ind;
        void *store_data;
#ifndef LELY_NO_CO_MASTER
        co_lss_cs_ind_t *cs_ind;
        void *cs_data;
        co_lss_err_ind_t *err_ind;
        void *err_data;
        co_lss_lssid_ind_t *lssid_ind;
        void *lssid_data;
        co_lss_nid_ind_t *nid_ind;
        void *nid_data;
        co_lss_scan_ind_t *scan_ind;
        void *scan_data;
#endif
};

static int co_lss_recv(const struct can_msg *msg, void *data);

#ifndef LELY_NO_CO_MASTER
static int co_lss_timer(const struct timespec *tp, void *data);
#endif

static void co_lss_enter(co_lss_t *lss, co_lss_state_t *next);

static inline void co_lss_emit_recv(co_lss_t *lss, const struct can_msg *msg);

#ifndef LELY_NO_CO_MASTER

static inline void co_lss_emit_time(co_lss_t *lss, const struct timespec *tp);
#endif

struct __co_lss_state {
        co_lss_state_t *(*on_enter)(co_lss_t *lss);
        co_lss_state_t *(*on_recv)(co_lss_t *lss, const struct can_msg *msg);
#ifndef LELY_NO_CO_MASTER

        co_lss_state_t *(*on_time)(co_lss_t *lss, const struct timespec *tp);
#endif
        void (*on_leave)(co_lss_t *lss);
};

#define LELY_CO_DEFINE_STATE(name, ...) \
        static co_lss_state_t *const name = &(co_lss_state_t){ __VA_ARGS__ };

static co_lss_state_t *co_lss_wait_on_enter(co_lss_t *lss);

// clang-format off
LELY_CO_DEFINE_STATE(co_lss_wait_state,
        .on_enter = &co_lss_wait_on_enter
)
// clang-format on

static co_lss_state_t *co_lss_wait_slave_on_enter(co_lss_t *lss);

static co_lss_state_t *co_lss_wait_slave_on_recv(
                co_lss_t *lss, const struct can_msg *msg);

// clang-format off
LELY_CO_DEFINE_STATE(co_lss_wait_slave_state,
        .on_enter = &co_lss_wait_slave_on_enter,
        .on_recv = &co_lss_wait_slave_on_recv
)
// clang-format on

static co_lss_state_t *co_lss_cfg_on_recv(
                co_lss_t *lss, const struct can_msg *msg);

// clang-format off
LELY_CO_DEFINE_STATE(co_lss_cfg_state,
        .on_recv = &co_lss_cfg_on_recv
)
// clang-format on

#ifndef LELY_NO_CO_MASTER

static co_lss_state_t *co_lss_cs_on_recv(
                co_lss_t *lss, const struct can_msg *msg);

static co_lss_state_t *co_lss_cs_on_time(
                co_lss_t *lss, const struct timespec *tp);

static void co_lss_cs_on_leave(co_lss_t *lss);

// clang-format off
LELY_CO_DEFINE_STATE(co_lss_cs_state,
        .on_recv = &co_lss_cs_on_recv,
        .on_time = &co_lss_cs_on_time,
        .on_leave = &co_lss_cs_on_leave
)
// clang-format on

static co_lss_state_t *co_lss_err_on_recv(
                co_lss_t *lss, const struct can_msg *msg);

static co_lss_state_t *co_lss_err_on_time(
                co_lss_t *lss, const struct timespec *tp);

static void co_lss_err_on_leave(co_lss_t *lss);

// clang-format off
LELY_CO_DEFINE_STATE(co_lss_err_state,
        .on_recv = &co_lss_err_on_recv,
        .on_time = &co_lss_err_on_time,
        .on_leave = &co_lss_err_on_leave
)
// clang-format on

static co_lss_state_t *co_lss_lssid_on_recv(
                co_lss_t *lss, const struct can_msg *msg);

static co_lss_state_t *co_lss_lssid_on_time(
                co_lss_t *lss, const struct timespec *tp);

static void co_lss_lssid_on_leave(co_lss_t *lss);

// clang-format off
LELY_CO_DEFINE_STATE(co_lss_lssid_state,
        .on_recv = &co_lss_lssid_on_recv,
        .on_time = &co_lss_lssid_on_time,
        .on_leave = &co_lss_lssid_on_leave
)
// clang-format on

static co_lss_state_t *co_lss_nid_on_recv(
                co_lss_t *lss, const struct can_msg *msg);

static co_lss_state_t *co_lss_nid_on_time(
                co_lss_t *lss, const struct timespec *tp);

static void co_lss_nid_on_leave(co_lss_t *lss);

// clang-format off
LELY_CO_DEFINE_STATE(co_lss_nid_state,
        .on_recv = &co_lss_nid_on_recv,
        .on_time = &co_lss_nid_on_time,
        .on_leave = &co_lss_nid_on_leave
)
// clang-format on

static co_lss_state_t *co_lss_slowscan_init_on_recv(
                co_lss_t *lss, const struct can_msg *msg);

static co_lss_state_t *co_lss_slowscan_init_on_time(
                co_lss_t *lss, const struct timespec *tp);

// clang-format off
LELY_CO_DEFINE_STATE(co_lss_slowscan_init_state,
        .on_recv = &co_lss_slowscan_init_on_recv,
        .on_time = &co_lss_slowscan_init_on_time
)
// clang-format on

static co_lss_state_t *co_lss_slowscan_scan_on_enter(co_lss_t *lss);

static co_lss_state_t *co_lss_slowscan_scan_on_recv(
                co_lss_t *lss, const struct can_msg *msg);

static co_lss_state_t *co_lss_slowscan_scan_on_time(
                co_lss_t *lss, const struct timespec *tp);

static co_lss_state_t *co_lss_slowscan_scan_on_res(co_lss_t *lss, int timeout);

// clang-format off
LELY_CO_DEFINE_STATE(co_lss_slowscan_scan_state,
        .on_enter = &co_lss_slowscan_scan_on_enter,
        .on_recv = &co_lss_slowscan_scan_on_recv,
        .on_time = &co_lss_slowscan_scan_on_time
)
// clang-format on

static co_lss_state_t *co_lss_slowscan_wait_on_recv(
                co_lss_t *lss, const struct can_msg *msg);

static co_lss_state_t *co_lss_slowscan_wait_on_time(
                co_lss_t *lss, const struct timespec *tp);

// clang-format off
LELY_CO_DEFINE_STATE(co_lss_slowscan_wait_state,
        .on_recv = &co_lss_slowscan_wait_on_recv,
        .on_time = &co_lss_slowscan_wait_on_time
)
// clang-format on

static co_lss_state_t *co_lss_slowscan_switch_on_enter(co_lss_t *lss);

static co_lss_state_t *co_lss_slowscan_switch_on_recv(
                co_lss_t *lss, const struct can_msg *msg);

static co_lss_state_t *co_lss_slowscan_switch_on_time(
                co_lss_t *lss, const struct timespec *tp);

// clang-format off
LELY_CO_DEFINE_STATE(co_lss_slowscan_switch_state,
        .on_enter = &co_lss_slowscan_switch_on_enter,
        .on_recv = &co_lss_slowscan_switch_on_recv,
        .on_time = &co_lss_slowscan_switch_on_time
)
// clang-format on

static co_lss_state_t *co_lss_slowscan_fini_on_enter(co_lss_t *lss);

static void co_lss_slowscan_fini_on_leave(co_lss_t *lss);

// clang-format off
LELY_CO_DEFINE_STATE(co_lss_slowscan_fini_state,
        .on_enter = &co_lss_slowscan_fini_on_enter,
        .on_leave = &co_lss_slowscan_fini_on_leave
)
// clang-format on

static co_lss_state_t *co_lss_fastscan_init_on_recv(
                co_lss_t *lss, const struct can_msg *msg);

static co_lss_state_t *co_lss_fastscan_init_on_time(
                co_lss_t *lss, const struct timespec *tp);

// clang-format off
LELY_CO_DEFINE_STATE(co_lss_fastscan_init_state,
        .on_recv = &co_lss_fastscan_init_on_recv,
        .on_time = &co_lss_fastscan_init_on_time
)
// clang-format on

static co_lss_state_t *co_lss_fastscan_scan_on_enter(co_lss_t *lss);

static co_lss_state_t *co_lss_fastscan_scan_on_recv(
                co_lss_t *lss, const struct can_msg *msg);

static co_lss_state_t *co_lss_fastscan_scan_on_time(
                co_lss_t *lss, const struct timespec *tp);

static co_lss_state_t *co_lss_fastscan_scan_on_res(co_lss_t *lss, int timeout);

// clang-format off
LELY_CO_DEFINE_STATE(co_lss_fastscan_scan_state,
        .on_enter = &co_lss_fastscan_scan_on_enter,
        .on_recv = &co_lss_fastscan_scan_on_recv,
        .on_time = &co_lss_fastscan_scan_on_time
)
// clang-format on

static co_lss_state_t *co_lss_fastscan_wait_on_recv(
                co_lss_t *lss, const struct can_msg *msg);

static co_lss_state_t *co_lss_fastscan_wait_on_time(
                co_lss_t *lss, const struct timespec *tp);

// clang-format off
LELY_CO_DEFINE_STATE(co_lss_fastscan_wait_state,
        .on_recv = &co_lss_fastscan_wait_on_recv,
        .on_time = &co_lss_fastscan_wait_on_time
)
// clang-format on

static co_lss_state_t *co_lss_fastscan_fini_on_enter(co_lss_t *lss);

static void co_lss_fastscan_fini_on_leave(co_lss_t *lss);

// clang-format off
LELY_CO_DEFINE_STATE(co_lss_fastscan_fini_state,
        .on_enter = &co_lss_fastscan_fini_on_enter,
        .on_leave = &co_lss_fastscan_fini_on_leave
)
// clang-format on

#endif // !LELY_NO_CO_MASTER

#undef LELY_CO_DEFINE_STATE

static co_lss_state_t *co_lss_switch_sel(
                co_lss_t *lss, co_unsigned8_t cs, co_unsigned32_t id);

static void co_lss_id_slave(
                co_lss_t *lss, co_unsigned8_t cs, co_unsigned32_t id);

static void co_lss_id_non_cfg_slave(const co_lss_t *lss);

static co_lss_state_t *co_lss_fastscan(co_lss_t *lss, co_unsigned32_t id,
                co_unsigned8_t bitchk, co_unsigned8_t lsssub,
                co_unsigned8_t lssnext);

static void co_lss_init_req(
                const co_lss_t *lss, struct can_msg *msg, co_unsigned8_t cs);

#ifndef LELY_NO_CO_MASTER

static int co_lss_send_switch_sel_req(
                const co_lss_t *lss, const struct co_id *id);

static int co_lss_send_id_slave_req(const co_lss_t *lss, const struct co_id *lo,
                const struct co_id *hi);

static int co_lss_send_fastscan_req(const co_lss_t *lss, co_unsigned32_t id,
                co_unsigned8_t bitchk, co_unsigned8_t lsssub,
                co_unsigned8_t lssnext);

static void co_lss_init_ind(co_lss_t *lss, co_unsigned8_t cs);

#endif

void *
__co_lss_alloc(void)
{
        void *ptr = malloc(sizeof(struct __co_lss));
        if (__unlikely(!ptr))
                set_errc(errno2c(errno));
        return ptr;
}

void
__co_lss_free(void *ptr)
{
        free(ptr);
}

struct __co_lss *
__co_lss_init(struct __co_lss *lss, co_nmt_t *nmt)
{
        assert(lss);
        assert(nmt);

        int errc = 0;

        lss->nmt = nmt;
        lss->net = co_nmt_get_net(lss->nmt);
        lss->dev = co_nmt_get_dev(lss->nmt);

        lss->state = NULL;

#ifndef LELY_NO_CO_MASTER
        lss->master = 0;
#endif

        lss->recv = can_recv_create();
        if (__unlikely(!lss->recv)) {
                errc = get_errc();
                goto error_create_recv;
        }
        can_recv_set_func(lss->recv, &co_lss_recv, lss);

#ifndef LELY_NO_CO_MASTER
        lss->timeout = LELY_CO_LSS_TIMEOUT;

        lss->timer = can_timer_create();
        if (__unlikely(!lss->timer)) {
                errc = get_errc();
                goto error_create_timer;
        }
        can_timer_set_func(lss->timer, &co_lss_timer, lss);
#endif

        lss->cs = 0;
        lss->lsspos = 0;
#ifndef LELY_NO_CO_MASTER
        lss->lo = (struct co_id)CO_ID_INIT;
        lss->hi = (struct co_id)CO_ID_INIT;
        lss->mask = (struct co_id)CO_ID_INIT;
        lss->bitchk = 0;
        lss->lsssub = 0;
        lss->err = 0;
        lss->spec = 0;
        lss->lssid = 0;
        lss->nid = 0;
        lss->id = (struct co_id)CO_ID_INIT;
#endif

        lss->rate_ind = NULL;
        lss->rate_data = NULL;
        lss->store_ind = NULL;
        lss->store_data = NULL;
#ifndef LELY_NO_CO_MASTER
        lss->cs_ind = NULL;
        lss->cs_data = NULL;
        lss->err_ind = NULL;
        lss->err_data = NULL;
        lss->lssid_ind = NULL;
        lss->lssid_data = NULL;
        lss->nid_ind = NULL;
        lss->nid_data = NULL;
        lss->scan_ind = NULL;
        lss->scan_data = NULL;
#endif

        co_lss_enter(lss, co_lss_wait_state);
        return lss;

#ifndef LELY_NO_CO_MASTER
        can_timer_destroy(lss->timer);
error_create_timer:
#endif
        can_recv_destroy(lss->recv);
error_create_recv:
        set_errc(errc);
        return NULL;
}

void
__co_lss_fini(struct __co_lss *lss)
{
        assert(lss);

#ifndef LELY_NO_CO_MASTER
        can_timer_destroy(lss->timer);
#endif
        can_recv_destroy(lss->recv);
}

co_lss_t *
co_lss_create(co_nmt_t *nmt)
{
        trace("creating LSS");

        int errc = 0;

        co_lss_t *lss = __co_lss_alloc();
        if (__unlikely(!lss)) {
                errc = get_errc();
                goto error_alloc_lss;
        }

        if (__unlikely(!__co_lss_init(lss, nmt))) {
                errc = get_errc();
                goto error_init_lss;
        }

        return lss;

error_init_lss:
        __co_lss_free(lss);
error_alloc_lss:
        set_errc(errc);
        return NULL;
}

void
co_lss_destroy(co_lss_t *lss)
{
        if (lss) {
                trace("destroying LSS");
                __co_lss_fini(lss);
                __co_lss_free(lss);
        }
}

co_nmt_t *
co_lss_get_nmt(const co_lss_t *lss)
{
        assert(lss);

        return lss->nmt;
}

void
co_lss_get_rate_ind(const co_lss_t *lss, co_lss_rate_ind_t **pind, void **pdata)
{
        assert(lss);

        if (pind)
                *pind = lss->rate_ind;
        if (pdata)
                *pdata = lss->rate_data;
}

void
co_lss_set_rate_ind(co_lss_t *lss, co_lss_rate_ind_t *ind, void *data)
{
        assert(lss);

        lss->rate_ind = ind;
        lss->rate_data = data;
}

void
co_lss_get_store_ind(
                const co_lss_t *lss, co_lss_store_ind_t **pind, void **pdata)
{
        assert(lss);

        if (pind)
                *pind = lss->store_ind;
        if (pdata)
                *pdata = lss->store_data;
}

void
co_lss_set_store_ind(co_lss_t *lss, co_lss_store_ind_t *ind, void *data)
{
        assert(lss);

        lss->store_ind = ind;
        lss->store_data = data;
}

#ifndef LELY_NO_CO_MASTER

int
co_lss_get_timeout(const co_lss_t *lss)
{
        assert(lss);

        return lss->timeout;
}

void
co_lss_set_timeout(co_lss_t *lss, int timeout)
{
        assert(lss);

        if (lss->timeout && timeout <= 0)
                can_timer_stop(lss->timer);

        lss->timeout = MAX(0, timeout);
}

#endif

int
co_lss_is_master(const co_lss_t *lss)
{
#ifdef LELY_NO_CO_MASTER
        (void)lss;

        return 0;
#else
        assert(lss);

        return lss->master;
#endif
}

#ifndef LELY_NO_CO_MASTER

int
co_lss_is_idle(const co_lss_t *lss)
{
        assert(lss);

        return lss->state == co_lss_wait_state;
}

void
co_lss_abort_req(co_lss_t *lss)
{
        assert(lss);

        co_lss_enter(lss, co_lss_wait_state);
}

int
co_lss_switch_req(co_lss_t *lss, co_unsigned8_t mode)
{
        if (__unlikely(!co_lss_is_master(lss) || !co_lss_is_idle(lss))) {
                set_errnum(ERRNUM_PERM);
                return -1;
        }

        if (__unlikely(mode > 0x01)) {
                set_errnum(ERRNUM_INVAL);
                return -1;
        }

        trace("LSS: switch state global");

        // Switch state global (see Fig. 31 in CiA 305 version 3.0.0).
        struct can_msg req;
        co_lss_init_req(lss, &req, 0x04);
        req.data[1] = mode;
        return can_net_send(lss->net, &req);
}

int
co_lss_switch_sel_req(co_lss_t *lss, const struct co_id *id,
                co_lss_cs_ind_t *ind, void *data)
{
        if (__unlikely(!co_lss_is_master(lss) || !co_lss_is_idle(lss))) {
                set_errnum(ERRNUM_PERM);
                return -1;
        }

        trace("LSS: switch state selective");

        // Switch state selective (see Fig. 32 in CiA 305 version 3.0.0).
        if (__unlikely(co_lss_send_switch_sel_req(lss, id) == -1))
                return -1;

        // Wait for response.
        co_lss_init_ind(lss, 0x44);
        lss->cs_ind = ind;
        lss->cs_data = data;
        co_lss_enter(lss, co_lss_cs_state);

        return 0;
}

int
co_lss_set_id_req(co_lss_t *lss, co_unsigned8_t id, co_lss_err_ind_t *ind,
                void *data)
{
        if (__unlikely(!co_lss_is_master(lss) || !co_lss_is_idle(lss))) {
                set_errnum(ERRNUM_PERM);
                return -1;
        }

        if (__unlikely(!id || (id > CO_NUM_NODES && id != 0xff))) {
                set_errnum(ERRNUM_INVAL);
                return -1;
        }

        trace("LSS: configure node-ID");

        // Configure node-ID (see Fig. 33 in CiA 305 version 3.0.0).
        struct can_msg req;
        co_lss_init_req(lss, &req, 0x11);
        req.data[1] = id;
        if (__unlikely(can_net_send(lss->net, &req) == -1))
                return -1;

        // Wait for response.
        co_lss_init_ind(lss, req.data[0]);
        lss->err_ind = ind;
        lss->err_data = data;
        co_lss_enter(lss, co_lss_err_state);

        return 0;
}

int
co_lss_set_rate_req(co_lss_t *lss, co_unsigned16_t rate, co_lss_err_ind_t *ind,
                void *data)
{
        if (__unlikely(!co_lss_is_master(lss) || !co_lss_is_idle(lss))) {
                set_errnum(ERRNUM_PERM);
                return -1;
        }

        // Configure bit timing parameters (see Fig. 34 in CiA 305 version
        // 3.0.0).
        struct can_msg req;
        co_lss_init_req(lss, &req, 0x13);
        req.data[1] = 0;
        switch (rate) {
        case 1000: req.data[2] = 0; break;
        case 800: req.data[2] = 1; break;
        case 500: req.data[2] = 2; break;
        case 250: req.data[2] = 3; break;
        case 125: req.data[2] = 4; break;
        case 50: req.data[2] = 6; break;
        case 20: req.data[2] = 7; break;
        case 10: req.data[2] = 8; break;
        case 0: req.data[2] = 9; break;
        default: set_errnum(ERRNUM_INVAL); return 0;
        }

        trace("LSS: configure bit timing parameters");

        if (__unlikely(can_net_send(lss->net, &req) == -1))
                return -1;

        // Wait for response.
        co_lss_init_ind(lss, req.data[0]);
        lss->err_ind = ind;
        lss->err_data = data;
        co_lss_enter(lss, co_lss_err_state);

        return 0;
}

int
co_lss_switch_rate_req(co_lss_t *lss, int delay)
{
        if (__unlikely(!co_lss_is_master(lss) || !co_lss_is_idle(lss))) {
                set_errnum(ERRNUM_PERM);
                return -1;
        }

        // clang-format off
        if (__unlikely(delay < CO_UNSIGNED16_MIN
                        || delay > CO_UNSIGNED16_MAX)) {
                // clang-format on
                set_errnum(ERRNUM_INVAL);
                return -1;
        }

        trace("LSS: activate bit timing parameters");

        // Activate bit timing parameters (see Fig. 35 in CiA 305 version
        // 3.0.0).
        struct can_msg req;
        co_lss_init_req(lss, &req, 0x15);
        stle_u16(req.data + 1, (co_unsigned16_t)delay);
        return can_net_send(lss->net, &req);
}

int
co_lss_store_req(co_lss_t *lss, co_lss_err_ind_t *ind, void *data)
{
        if (__unlikely(!co_lss_is_master(lss) || !co_lss_is_idle(lss))) {
                set_errnum(ERRNUM_PERM);
                return -1;
        }

        trace("LSS: store configuration");

        // Store configuration (see Fig. 36 in CiA 305 version 3.0.0).
        struct can_msg req;
        co_lss_init_req(lss, &req, 0x17);
        if (__unlikely(can_net_send(lss->net, &req) == -1))
                return -1;

        // Wait for response.
        co_lss_init_ind(lss, req.data[0]);
        lss->err_ind = ind;
        lss->err_data = data;
        co_lss_enter(lss, co_lss_err_state);

        return 0;
}

int
co_lss_get_vendor_id_req(co_lss_t *lss, co_lss_lssid_ind_t *ind, void *data)
{
        if (__unlikely(!co_lss_is_master(lss) || !co_lss_is_idle(lss))) {
                set_errnum(ERRNUM_PERM);
                return -1;
        }

        trace("LSS: inquire identity vendor-ID");

        // Inquire identity vendor-ID (see Fig. 37 in CiA 305 version 3.0.0).
        struct can_msg req;
        co_lss_init_req(lss, &req, 0x5a);
        if (__unlikely(can_net_send(lss->net, &req) == -1))
                return -1;

        // Wait for response.
        co_lss_init_ind(lss, req.data[0]);
        lss->lssid_ind = ind;
        lss->lssid_data = data;
        co_lss_enter(lss, co_lss_lssid_state);

        return 0;
}

int
co_lss_get_product_code_req(co_lss_t *lss, co_lss_lssid_ind_t *ind, void *data)
{
        if (__unlikely(!co_lss_is_master(lss) || !co_lss_is_idle(lss))) {
                set_errnum(ERRNUM_PERM);
                return -1;
        }

        trace("LSS: inquire identity product-code");

        // Inquire identity product-code (see Fig. 38 in CiA 305 version 3.0.0).
        struct can_msg req;
        co_lss_init_req(lss, &req, 0x5b);
        if (__unlikely(can_net_send(lss->net, &req) == -1))
                return -1;

        // Wait for response.
        co_lss_init_ind(lss, req.data[0]);
        lss->lssid_ind = ind;
        lss->lssid_data = data;
        co_lss_enter(lss, co_lss_lssid_state);

        return 0;
}

int
co_lss_get_revision_req(co_lss_t *lss, co_lss_lssid_ind_t *ind, void *data)
{
        if (__unlikely(!co_lss_is_master(lss) || !co_lss_is_idle(lss))) {
                set_errnum(ERRNUM_PERM);
                return -1;
        }

        trace("LSS: inquire identity revision-number");

        // Inquire identity revision-number (see Fig. 39 in CiA 305 version
        // 3.0.0).
        struct can_msg req;
        co_lss_init_req(lss, &req, 0x5c);
        if (__unlikely(can_net_send(lss->net, &req) == -1))
                return -1;

        // Wait for response.
        co_lss_init_ind(lss, req.data[0]);
        lss->lssid_ind = ind;
        lss->lssid_data = data;
        co_lss_enter(lss, co_lss_lssid_state);

        return 0;
}

int
co_lss_get_serial_nr_req(co_lss_t *lss, co_lss_lssid_ind_t *ind, void *data)
{
        if (__unlikely(!co_lss_is_master(lss) || !co_lss_is_idle(lss))) {
                set_errnum(ERRNUM_PERM);
                return -1;
        }

        trace("LSS: inquire identity serial number");

        // Inquire identity serial-number (see Fig. 40 in CiA 305 version
        // 3.0.0).
        struct can_msg req;
        co_lss_init_req(lss, &req, 0x5d);
        if (__unlikely(can_net_send(lss->net, &req) == -1))
                return -1;

        // Wait for response.
        co_lss_init_ind(lss, req.data[0]);
        lss->lssid_ind = ind;
        lss->lssid_data = data;
        co_lss_enter(lss, co_lss_lssid_state);

        return 0;
}

int
co_lss_get_id_req(co_lss_t *lss, co_lss_nid_ind_t *ind, void *data)
{
        if (__unlikely(!co_lss_is_master(lss) || !co_lss_is_idle(lss))) {
                set_errnum(ERRNUM_PERM);
                return -1;
        }

        trace("LSS: inquire node-ID");

        // Inquire node-ID (see Fig. 41 in CiA 305 version 3.0.0).
        struct can_msg req;
        co_lss_init_req(lss, &req, 0x5e);
        if (__unlikely(can_net_send(lss->net, &req) == -1))
                return -1;

        // Wait for response.
        co_lss_init_ind(lss, req.data[0]);
        lss->nid_ind = ind;
        lss->nid_data = data;
        co_lss_enter(lss, co_lss_nid_state);

        return 0;
}

int
co_lss_id_slave_req(co_lss_t *lss, const struct co_id *lo,
                const struct co_id *hi, co_lss_cs_ind_t *ind, void *data)
{
        if (__unlikely(!co_lss_is_master(lss) || !co_lss_is_idle(lss))) {
                set_errnum(ERRNUM_PERM);
                return -1;
        }

        trace("LSS: identify remote slave");

        // LSS identify remote slave (see Fig. 42 in CiA 305 version 3.0.0).
        if (__unlikely(co_lss_send_id_slave_req(lss, lo, hi) == -1))
                return -1;

        // Wait for response (see Fig. 43 in CiA 305 version 3.0.0).
        co_lss_init_ind(lss, 0x4f);
        lss->cs_ind = ind;
        lss->cs_data = data;
        co_lss_enter(lss, co_lss_cs_state);

        return 0;
}

int
co_lss_id_non_cfg_slave_req(co_lss_t *lss, co_lss_cs_ind_t *ind, void *data)
{
        if (__unlikely(!co_lss_is_master(lss) || !co_lss_is_idle(lss))) {
                set_errnum(ERRNUM_PERM);
                return -1;
        }

        trace("LSS: identify non-configured remote slave");

        // LSS identify non-configured remote slave (see Fig. 44 in CiA 305
        // version 3.0.0).
        struct can_msg req;
        co_lss_init_req(lss, &req, 0x4c);
        if (__unlikely(can_net_send(lss->net, &req) == -1))
                return -1;

        // Wait for response (see Fig. 45 in CiA 305 version 3.0.0).
        co_lss_init_ind(lss, 0x50);
        lss->cs_ind = ind;
        lss->cs_data = data;
        co_lss_enter(lss, co_lss_cs_state);

        return 0;
}

int
co_lss_slowscan_req(co_lss_t *lss, const struct co_id *lo,
                const struct co_id *hi, co_lss_scan_ind_t *ind, void *data)
{
        assert(lo);
        assert(hi);

        if (__unlikely(!co_lss_is_master(lss) || !co_lss_is_idle(lss))) {
                set_errnum(ERRNUM_PERM);
                return -1;
        }

        trace("LSS: Slowscan");

        lss->lo = *lo;
        lss->lo.n = 4;
        lss->hi = *hi;
        lss->hi.n = 4;

        // LSS identify remote slave (see Fig. 42 in CiA 305 version 3.0.0).
        if (__unlikely(co_lss_send_id_slave_req(lss, &lss->lo, &lss->hi) == -1))
                return -1;

        lss->id = (struct co_id)CO_ID_INIT;

        // Wait for response (see Fig. 43 in CiA 305 version 3.0.0).
        co_lss_init_ind(lss, 0x4f);
        lss->scan_ind = ind;
        lss->scan_data = data;
        co_lss_enter(lss, co_lss_slowscan_init_state);

        return 0;
}

int
co_lss_fastscan_req(co_lss_t *lss, const struct co_id *id,
                const struct co_id *mask, co_lss_scan_ind_t *ind, void *data)
{
        if (__unlikely(!co_lss_is_master(lss) || !co_lss_is_idle(lss))) {
                set_errnum(ERRNUM_PERM);
                return -1;
        }

        trace("LSS: Fastscan");

        lss->id = (struct co_id)CO_ID_INIT;
        lss->mask = (struct co_id)CO_ID_INIT;
        if (mask) {
                lss->mask = *mask;
                lss->mask.n = 4;
                if (id) {
                        lss->id = *id;
                        lss->id.n = 4;
                        // Clear all unmasked bits in the LSS address.
                        lss->id.vendor_id &= lss->mask.vendor_id;
                        lss->id.product_code &= lss->mask.product_code;
                        lss->id.revision &= lss->mask.revision;
                        lss->id.serial_nr &= lss->mask.serial_nr;
                }
        }
        lss->bitchk = 0x80;
        lss->lsssub = 0;

        // LSS Fastscan (see Fig. 46 in CiA 305 version 3.0.0).
        struct can_msg req;
        co_lss_init_req(lss, &req, 0x51);
        req.data[5] = lss->bitchk;
        if (__unlikely(can_net_send(lss->net, &req) == -1))
                return -1;

        // Wait for response (see Fig. 43 in CiA 305 version 3.0.0).
        co_lss_init_ind(lss, 0x4f);
        lss->scan_ind = ind;
        lss->scan_data = data;
        co_lss_enter(lss, co_lss_fastscan_init_state);

        return 0;
}

#endif // !LELY_NO_CO_MASTER

static int
co_lss_recv(const struct can_msg *msg, void *data)
{
        assert(msg);
        co_lss_t *lss = data;
        assert(lss);

        co_lss_emit_recv(lss, msg);

        return 0;
}

#ifndef LELY_NO_CO_MASTER
static int
co_lss_timer(const struct timespec *tp, void *data)
{
        assert(tp);
        co_lss_t *lss = data;
        assert(lss);

        co_lss_emit_time(lss, tp);

        return 0;
}
#endif

static void
co_lss_enter(co_lss_t *lss, co_lss_state_t *next)
{
        assert(lss);

        while (next) {
                co_lss_state_t *prev = lss->state;
                lss->state = next;

                if (prev && prev->on_leave)
                        prev->on_leave(lss);

                next = next->on_enter ? next->on_enter(lss) : NULL;
        }
}

static inline void
co_lss_emit_recv(co_lss_t *lss, const struct can_msg *msg)
{
        assert(lss);
        assert(lss->state);
        assert(lss->state->on_recv);

        co_lss_enter(lss, lss->state->on_recv(lss, msg));
}

#ifndef LELY_NO_CO_MASTER
static inline void
co_lss_emit_time(co_lss_t *lss, const struct timespec *tp)
{
        assert(lss);
        assert(lss->state);
        assert(lss->state->on_time);

        co_lss_enter(lss, lss->state->on_time(lss, tp));
}
#endif

static co_lss_state_t *
co_lss_wait_on_enter(co_lss_t *lss)
{
        assert(lss);

#ifndef LELY_NO_CO_MASTER
        // Only an NMT master can be an LSS master.
        lss->master = co_nmt_is_master(lss->nmt);
        if (lss->master)
                return NULL;
#endif

        return co_lss_wait_slave_state;
}

static co_lss_state_t *
co_lss_wait_slave_on_enter(co_lss_t *lss)
{
        assert(lss);

        lss->cs = 0;
        lss->lsspos = 0;

        // Start receiving LSS commands from the master.
        can_recv_start(lss->recv, lss->net, CO_LSS_CANID(1), 0);

        return NULL;
}

static co_lss_state_t *
co_lss_wait_slave_on_recv(co_lss_t *lss, const struct can_msg *msg)
{
        assert(lss);
        assert(msg);

        if (__unlikely(!msg->len))
                return NULL;

        uint8_t cs = msg->data[0];
        switch (cs) {
        // Switch state global (see Fig. 31 in CiA 305 version 3.0.0).
        case 0x04:
                if (__unlikely(msg->len < 2))
                        return NULL;
                switch (msg->data[1]) {
                case 0x00:
                        // Re-enter the waiting state.
                        trace("LSS: switching to waiting state");
                        return co_lss_wait_state;
                case 0x01:
                        // Switch to the configuration state.
                        trace("LSS: switching to configuration state");
                        return co_lss_cfg_state;
                }
                break;
        // Switch state selective.
        case 0x40:
        case 0x41:
        case 0x42:
        case 0x43:
                if (msg->len < 5)
                        return NULL;
                return co_lss_switch_sel(lss, cs, ldle_u32(msg->data + 1));
        // LSS identify remote slave.
        case 0x46:
        case 0x47:
        case 0x48:
        case 0x49:
        case 0x4a:
        case 0x4b:
                if (msg->len < 5)
                        return NULL;
                co_lss_id_slave(lss, msg->data[0], ldle_u32(msg->data + 1));
                break;
        // LSS identify non-configured remote slave.
        case 0x4c: co_lss_id_non_cfg_slave(lss); break;
        // LSS Fastscan.
        case 0x51:
                if (msg->len < 8)
                        return NULL;
                return co_lss_fastscan(lss, ldle_u32(msg->data + 1),
                                msg->data[5], msg->data[6], msg->data[7]);
        }

        return NULL;
}

static co_lss_state_t *
co_lss_cfg_on_recv(co_lss_t *lss, const struct can_msg *msg)
{
        assert(lss);
        assert(msg);

        int errc = get_errc();
        co_obj_t *obj_1018 = co_dev_find_obj(lss->dev, 0x1018);
        struct can_msg req;

        if (__unlikely(!msg->len))
                return NULL;

        co_unsigned8_t cs = msg->data[0];
        switch (cs) {
        // Switch state global (see Fig. 31 in CiA 305 version 3.0.0).
        case 0x04:
                if (__unlikely(msg->len < 2))
                        return NULL;
                switch (msg->data[1]) {
                case 0x00:
                        // Switch to the waiting state.
                        trace("LSS: switching to waiting state");
                        return co_lss_wait_state;
                case 0x01:
                        // Re-enter the configuration state.
                        trace("LSS: switching to configuration state");
                        return co_lss_cfg_state;
                }
                break;
        // Configure node-ID (see Fig. 33 in CiA 305 version 3.0.0).
        case 0x11:
                if (msg->len < 2)
                        return NULL;
                // Configure the pending node-ID.
                trace("LSS: configuring node-ID");
                co_lss_init_req(lss, &req, cs);
                if (co_nmt_set_id(lss->nmt, msg->data[1]) == -1) {
                        // Discard the error code if the node-ID was invalid.
                        set_errc(errc);
                        req.data[1] = 1;
                }
                can_net_send(lss->net, &req);
                break;
        // Configure bit timing parameters (see Fig. 34 in CiA 305 version
        // 3.0.0).
        case 0x13:
                if (msg->len < 3)
                        return NULL;
                // Configure the pending baudrate.
                trace("LSS: configuring bit timing parameters");
                co_lss_init_req(lss, &req, cs);
                if (__unlikely(!lss->rate_ind || msg->data[1])) {
                        req.data[1] = 1;
                } else {
                        unsigned int baud = co_dev_get_baud(lss->dev);
                        switch (msg->data[2]) {
                        case 0:
                                if (!(req.data[1] = !(baud & CO_BAUD_1000)))
                                        co_dev_set_rate(lss->dev, 1000);
                                break;
                        case 1:
                                if (!(req.data[1] = !(baud & CO_BAUD_800)))
                                        co_dev_set_rate(lss->dev, 800);
                                break;
                        case 2:
                                if (!(req.data[1] = !(baud & CO_BAUD_500)))
                                        co_dev_set_rate(lss->dev, 500);
                                break;
                        case 3:
                                if (!(req.data[1] = !(baud & CO_BAUD_250)))
                                        co_dev_set_rate(lss->dev, 250);
                                break;
                        case 4:
                                if (!(req.data[1] = !(baud & CO_BAUD_125)))
                                        co_dev_set_rate(lss->dev, 135);
                                break;
                        case 6:
                                if (!(req.data[1] = !(baud & CO_BAUD_50)))
                                        co_dev_set_rate(lss->dev, 50);
                                break;
                        case 7:
                                if (!(req.data[1] = !(baud & CO_BAUD_20)))
                                        co_dev_set_rate(lss->dev, 20);
                                break;
                        case 8:
                                if (!(req.data[1] = !(baud & CO_BAUD_10)))
                                        co_dev_set_rate(lss->dev, 10);
                                break;
                        case 9:
                                if (!(req.data[1] = !(baud & CO_BAUD_AUTO)))
                                        co_dev_set_rate(lss->dev, 0);
                                break;
                        default: req.data[1] = 1; break;
                        }
                }
                can_net_send(lss->net, &req);
                break;
        // Activate bit timing parameters (see Fig. 35 in CiA 305 version
        // 3.0.0).
        case 0x15:
                if (msg->len < 3 || !lss->rate_ind)
                        return NULL;
                // Invoke the user-specified callback function to perform the
                // baudrate switch.
                trace("LSS: activating bit timing parameters");
                lss->rate_ind(lss, co_dev_get_rate(lss->dev),
                                ldle_u16(msg->data + 1), lss->rate_data);
                break;
        // Store configuration (see Fig. 36 in CiA 305 version 3.0.0).
        case 0x17:
                trace("LSS: storing configuration");
                co_lss_init_req(lss, &req, cs);
                if (lss->store_ind) {
                        // Store the pending node-ID and baudrate.
                        // clang-format off
                        if (__unlikely(lss->store_ind(lss,
                                        co_nmt_get_id(lss->nmt),
                                        co_dev_get_rate(lss->dev),
                                        lss->store_data) == -1)) {
                                // clang-format on
                                // Discard the error code.
                                set_errc(errc);
                                req.data[1] = 2;
                        }
                } else {
                        req.data[1] = 1;
                }
                can_net_send(lss->net, &req);
                break;
        // LSS identify remote slave.
        case 0x46:
        case 0x47:
        case 0x48:
        case 0x49:
        case 0x4a:
        case 0x4b:
                if (msg->len < 5)
                        return NULL;
                co_lss_id_slave(lss, cs, ldle_u32(msg->data + 1));
                break;
        // LSS identify non-configured remote slave.
        case 0x4c: co_lss_id_non_cfg_slave(lss); break;
        // Inquire identity vendor-ID (Fig. 37 in CiA 305 version 3.0.0).
        case 0x5a:
                trace("LSS: sending vendor-ID");
                co_lss_init_req(lss, &req, cs);
                stle_u32(req.data + 1, co_obj_get_val_u32(obj_1018, 0x01));
                can_net_send(lss->net, &req);
                break;
        // Inquire identity product-code (Fig. 38 in CiA 305 version 3.0.0).
        case 0x5b:
                trace("LSS: sending product-code");
                co_lss_init_req(lss, &req, cs);
                stle_u32(req.data + 1, co_obj_get_val_u32(obj_1018, 0x02));
                can_net_send(lss->net, &req);
                break;
        // Inquire identity revision-number (Fig. 39 in CiA 305 version 3.0.0).
        case 0x5c:
                trace("LSS: sending revision-number");
                co_lss_init_req(lss, &req, cs);
                stle_u32(req.data + 1, co_obj_get_val_u32(obj_1018, 0x03));
                can_net_send(lss->net, &req);
                break;
        // Inquire identity serial-number (Fig. 40 in CiA 305 version 3.0.0).
        case 0x5d:
                trace("LSS: sending serial-number");
                co_lss_init_req(lss, &req, cs);
                stle_u32(req.data + 1, co_obj_get_val_u32(obj_1018, 0x04));
                can_net_send(lss->net, &req);
                break;
        // Inquire node-ID (Fig. 41 in CiA 305 version 3.0.0).
        case 0x5e:
                trace("LSS: sending node-ID");
                co_lss_init_req(lss, &req, cs);
                // Respond with the active or pending node-ID, depending on
                // whether the device is in the NMT state Initializing.
                switch (co_nmt_get_st(lss->nmt)) {
                case CO_NMT_ST_BOOTUP:
                case CO_NMT_ST_RESET_NODE:
                case CO_NMT_ST_RESET_COMM:
                        req.data[1] = co_nmt_get_id(lss->nmt);
                        break;
                default: req.data[1] = co_dev_get_id(lss->dev); break;
                }
                can_net_send(lss->net, &req);
                break;
        }

        return NULL;
}

#ifndef LELY_NO_CO_MASTER

static co_lss_state_t *
co_lss_cs_on_recv(co_lss_t *lss, const struct can_msg *msg)
{
        assert(lss);
        assert(msg);

        if (msg->len < 1 || msg->data[0] != lss->cs)
                return NULL;

        return co_lss_wait_state;
}

static co_lss_state_t *
co_lss_cs_on_time(co_lss_t *lss, const struct timespec *tp)
{
        assert(lss);
        (void)tp;

        lss->cs = 0;
        return co_lss_wait_state;
}

static void
co_lss_cs_on_leave(co_lss_t *lss)
{
        assert(lss);

        can_timer_stop(lss->timer);
        can_recv_stop(lss->recv);

        if (lss->cs_ind)
                lss->cs_ind(lss, lss->cs, lss->cs_data);
}

static co_lss_state_t *
co_lss_err_on_recv(co_lss_t *lss, const struct can_msg *msg)
{
        assert(lss);
        assert(msg);

        if (msg->len < 3 || msg->data[0] != lss->cs)
                return NULL;

        lss->err = msg->data[1];
        lss->spec = lss->err == 0xff ? msg->data[2] : 0;
        return co_lss_wait_state;
}

static co_lss_state_t *
co_lss_err_on_time(co_lss_t *lss, const struct timespec *tp)
{
        assert(lss);
        (void)tp;

        lss->cs = 0;
        return co_lss_wait_state;
}

static void
co_lss_err_on_leave(co_lss_t *lss)
{
        assert(lss);

        can_timer_stop(lss->timer);
        can_recv_stop(lss->recv);

        if (lss->err_ind)
                lss->err_ind(lss, lss->cs, lss->err, lss->spec, lss->err_data);
}

static co_lss_state_t *
co_lss_lssid_on_recv(co_lss_t *lss, const struct can_msg *msg)
{
        assert(lss);
        assert(msg);

        if (msg->len < 5 || msg->data[0] != lss->cs)
                return NULL;

        lss->lssid = ldle_u32(msg->data + 1);
        return co_lss_wait_state;
}

static co_lss_state_t *
co_lss_lssid_on_time(co_lss_t *lss, const struct timespec *tp)
{
        assert(lss);
        (void)tp;

        lss->cs = 0;
        return co_lss_wait_state;
}

static void
co_lss_lssid_on_leave(co_lss_t *lss)
{
        assert(lss);

        can_timer_stop(lss->timer);
        can_recv_stop(lss->recv);

        if (lss->lssid_ind)
                lss->lssid_ind(lss, lss->cs, lss->lssid, lss->lssid_data);
}

static co_lss_state_t *
co_lss_nid_on_recv(co_lss_t *lss, const struct can_msg *msg)
{
        assert(lss);
        assert(msg);

        if (msg->len < 2 || msg->data[0] != lss->cs)
                return NULL;

        lss->nid = msg->data[1];
        return co_lss_wait_state;
}

static co_lss_state_t *
co_lss_nid_on_time(co_lss_t *lss, const struct timespec *tp)
{
        assert(lss);
        (void)tp;

        lss->cs = 0;
        return co_lss_wait_state;
}

static void
co_lss_nid_on_leave(co_lss_t *lss)
{
        assert(lss);

        can_timer_stop(lss->timer);
        can_recv_stop(lss->recv);

        if (lss->nid_ind)
                lss->nid_ind(lss, lss->cs, lss->nid, lss->nid_data);
}

static co_lss_state_t *
co_lss_slowscan_init_on_recv(co_lss_t *lss, const struct can_msg *msg)
{
        assert(lss);
        assert(msg);

        if (msg->len < 1 || msg->data[0] != lss->cs)
                return NULL;

        return co_lss_slowscan_scan_state;
}

static co_lss_state_t *
co_lss_slowscan_init_on_time(co_lss_t *lss, const struct timespec *tp)
{
        assert(lss);
        (void)tp;

        // Abort if we did not receive a response on the first request.
        lss->cs = 0;
        return co_lss_slowscan_fini_state;
}

static co_lss_state_t *
co_lss_slowscan_scan_on_enter(co_lss_t *lss)
{
        assert(lss);

        struct co_id *id = &lss->id;

        // Calculate the midpoint while avoiding integer overflow.
        *id = lss->lo;
        if (id->revision < lss->hi.revision) {
                id->revision += (lss->hi.revision - id->revision) / 2;
                id->serial_nr = lss->hi.serial_nr;
        } else {
                id->serial_nr += (lss->hi.serial_nr - id->serial_nr) / 2;
        }

        // LSS identify remote slave (see Fig. 42 in CiA 305 version 3.0.0).
        if (__unlikely(co_lss_send_id_slave_req(lss, &lss->lo, id) == -1)) {
                // Abort if sending the CAN frame failed.
                lss->cs = 0;
                return co_lss_slowscan_fini_state;
        }

        // Restart the timeout for the next response.
        can_timer_timeout(lss->timer, lss->net, lss->timeout);
        return NULL;
}

static co_lss_state_t *
co_lss_slowscan_scan_on_recv(co_lss_t *lss, const struct can_msg *msg)
{
        assert(lss);
        assert(msg);

        if (msg->len < 1 || msg->data[0] != lss->cs)
                return NULL;

        // Wait until the timeout expires before handling the response.
        return co_lss_slowscan_wait_state;
}

static co_lss_state_t *
co_lss_slowscan_scan_on_time(co_lss_t *lss, const struct timespec *tp)
{
        assert(lss);
        (void)tp;

        return co_lss_slowscan_scan_on_res(lss, 1);
}

static co_lss_state_t *
co_lss_slowscan_scan_on_res(co_lss_t *lss, int timeout)
{
        assert(lss);

        if (lss->lo.revision == lss->hi.revision
                        && lss->lo.serial_nr == lss->hi.serial_nr) {
                // Abort if we timeout after sending the final LSS address.
                if (timeout) {
                        lss->cs = 0;
                        return co_lss_slowscan_fini_state;
                }
                // Switch the slave to the LSS configuration state.
                co_lss_init_ind(lss, 0x44);
                return co_lss_slowscan_switch_state;
        }

        // Update the bounds on the LSS address.
        if (timeout) {
                if (lss->id.revision < lss->hi.revision)
                        lss->lo.revision = lss->id.revision + 1;
                else
                        lss->lo.serial_nr = lss->id.serial_nr + 1;
        } else {
                lss->hi = lss->id;
        }

        // Start the next cycle.
        return co_lss_slowscan_scan_state;
}

static co_lss_state_t *
co_lss_slowscan_wait_on_recv(co_lss_t *lss, const struct can_msg *msg)
{
        (void)lss;
        (void)msg;

        // Ignore further responses from slaves.
        return NULL;
}

static co_lss_state_t *
co_lss_slowscan_wait_on_time(co_lss_t *lss, const struct timespec *tp)
{
        (void)lss;
        (void)tp;

        // All slaves should have responded by now.
        return co_lss_slowscan_scan_on_res(lss, 0);
}

static co_lss_state_t *
co_lss_slowscan_switch_on_enter(co_lss_t *lss)
{
        assert(lss);

        // Switch state selective (see Fig. 32 in CiA 305 version 3.0.0).
        if (__unlikely(co_lss_send_switch_sel_req(lss, &lss->id) == -1)) {
                // Abort if sending the CAN frame failed.
                lss->cs = 0;
                return co_lss_slowscan_fini_state;
        }

        // Restart the timeout for the response.
        can_timer_timeout(lss->timer, lss->net, lss->timeout);
        return NULL;
}

static co_lss_state_t *
co_lss_slowscan_switch_on_recv(co_lss_t *lss, const struct can_msg *msg)
{
        assert(lss);
        assert(msg);

        if (msg->len < 1 || msg->data[0] != lss->cs)
                return NULL;

        return co_lss_slowscan_fini_state;
}

static co_lss_state_t *
co_lss_slowscan_switch_on_time(co_lss_t *lss, const struct timespec *tp)
{
        assert(lss);
        (void)tp;

        // Abort if no response was received.
        lss->cs = 0;
        return co_lss_slowscan_fini_state;
}

static co_lss_state_t *
co_lss_slowscan_fini_on_enter(co_lss_t *lss)
{
        (void)lss;

        return co_lss_wait_state;
}

static void
co_lss_slowscan_fini_on_leave(co_lss_t *lss)
{
        assert(lss);

        can_timer_stop(lss->timer);
        can_recv_stop(lss->recv);

        if (lss->scan_ind)
                lss->scan_ind(lss, lss->cs, lss->cs ? &lss->id : NULL,
                                lss->scan_data);
}

static co_lss_state_t *
co_lss_fastscan_init_on_recv(co_lss_t *lss, const struct can_msg *msg)
{
        assert(lss);
        assert(msg);

        if (msg->len < 1 || msg->data[0] != lss->cs)
                return NULL;

        lss->bitchk = 31;
        return co_lss_fastscan_scan_state;
}

static co_lss_state_t *
co_lss_fastscan_init_on_time(co_lss_t *lss, const struct timespec *tp)
{
        assert(lss);
        (void)tp;

        // Abort if we did not receive a response on the reset request.
        lss->cs = 0;
        return co_lss_fastscan_fini_state;
}

static co_lss_state_t *
co_lss_fastscan_scan_on_enter(co_lss_t *lss)
{
        assert(lss);

        const co_unsigned32_t *pid = &lss->id.vendor_id;
        const co_unsigned32_t *pmask = &lss->mask.vendor_id;

        // Find the next unknown bit.
        for (; lss->bitchk
                        && (pmask[lss->lsssub] & (UINT32_C(1) << lss->bitchk));
                        lss->bitchk--)
                ;

        co_unsigned8_t lssnext = lss->lsssub;
        // If we obtained the complete LSS number, send it again and prepare for
        // the next number.
        if (!lss->bitchk && (pmask[lss->lsssub] & 1)) {
                if (lssnext < 3) {
                        lssnext++;
                } else {
                        lssnext = 0;
                }
        }

        // LSS Fastscan (see Fig. 46 in CiA 305 version 3.0.0).
        // clang-format off
        if (__unlikely(co_lss_send_fastscan_req(lss, pid[lss->lsssub],
                        lss->bitchk, lss->lsssub, lssnext) == -1)) {
                // Abort if sending the CAN frame failed.
                // clang-format on
                lss->cs = 0;
                return co_lss_fastscan_fini_state;
        }

        // Restart the timeout for the next response.
        can_timer_timeout(lss->timer, lss->net, lss->timeout);
        return NULL;
}

static co_lss_state_t *
co_lss_fastscan_scan_on_recv(co_lss_t *lss, const struct can_msg *msg)
{
        assert(lss);
        assert(msg);

        if (msg->len < 1 || msg->data[0] != lss->cs)
                return NULL;

        // Wait until the timeout expires before handling the response.
        return co_lss_fastscan_wait_state;
}

static co_lss_state_t *
co_lss_fastscan_scan_on_time(co_lss_t *lss, const struct timespec *tp)
{
        assert(lss);
        (void)tp;

        return co_lss_fastscan_scan_on_res(lss, 1);
}

static co_lss_state_t *
co_lss_fastscan_scan_on_res(co_lss_t *lss, int timeout)
{
        assert(lss);
        assert(lss->bitchk <= 31);
        assert(lss->lsssub < 4);

        co_unsigned32_t *pid = &lss->id.vendor_id;
        co_unsigned32_t *pmask = &lss->mask.vendor_id;

        if (!lss->bitchk && (pmask[lss->lsssub] & 1)) {
                // Abort if we timeout after sending the complete LSS number.
                if (__unlikely(timeout)) {
                        lss->cs = 0;
                        return co_lss_fastscan_fini_state;
                }
                // We're done if this was the last LSS number.
                if (++lss->lsssub == 4)
                        return co_lss_fastscan_fini_state;
                lss->bitchk = 31;
        } else {
                // Update the LSS address. A timeout indicates the bit is 1.
                if (timeout)
                        pid[lss->lsssub] |= UINT32_C(1) << lss->bitchk;
                pmask[lss->lsssub] |= UINT32_C(1) << lss->bitchk;
        }

        // Start the next cycle.
        return co_lss_fastscan_scan_state;
}

static co_lss_state_t *
co_lss_fastscan_wait_on_recv(co_lss_t *lss, const struct can_msg *msg)
{
        (void)lss;
        (void)msg;

        // Ignore further responses from slaves.
        return NULL;
}

static co_lss_state_t *
co_lss_fastscan_wait_on_time(co_lss_t *lss, const struct timespec *tp)
{
        (void)lss;
        (void)tp;

        // All slaves should have responded by now.
        return co_lss_fastscan_scan_on_res(lss, 0);
}

static co_lss_state_t *
co_lss_fastscan_fini_on_enter(co_lss_t *lss)
{
        (void)lss;

        return co_lss_wait_state;
}

static void
co_lss_fastscan_fini_on_leave(co_lss_t *lss)
{
        assert(lss);

        can_timer_stop(lss->timer);
        can_recv_stop(lss->recv);

        if (lss->scan_ind)
                lss->scan_ind(lss, lss->cs, lss->cs ? &lss->id : NULL,
                                lss->scan_data);
}

#endif // !LELY_NO_CO_MASTER

static co_lss_state_t *
co_lss_switch_sel(co_lss_t *lss, co_unsigned8_t cs, co_unsigned32_t id)
{
        assert(lss);

        co_obj_t *obj_1018 = co_dev_find_obj(lss->dev, 0x1018);
        struct can_msg req;

        switch (cs) {
        case 0x40:
                if (id != co_obj_get_val_u32(obj_1018, 0x01)) {
                        lss->cs = 0;
                        return NULL;
                }
                lss->cs = 0x41;
                return NULL;
        case 0x41:
                if (cs != lss->cs || id != co_obj_get_val_u32(obj_1018, 0x02)) {
                        lss->cs = 0;
                        return NULL;
                }
                lss->cs = 0x42;
                return NULL;
        case 0x42:
                if (cs != lss->cs || id != co_obj_get_val_u32(obj_1018, 0x03)) {
                        lss->cs = 0;
                        return NULL;
                }
                lss->cs = 0x43;
                return NULL;
        case 0x43:
                if (cs != lss->cs || id != co_obj_get_val_u32(obj_1018, 0x04)) {
                        lss->cs = 0;
                        return NULL;
                }
                lss->cs = 0;
                // Notify the master of the state switch.
                co_lss_init_req(lss, &req, 0x44);
                can_net_send(lss->net, &req);
                // Switch to the configuration state.
                trace("LSS: switching to configuration state");
                return co_lss_cfg_state;
        default: return NULL;
        }
}

static void
co_lss_id_slave(co_lss_t *lss, co_unsigned8_t cs, co_unsigned32_t id)
{
        assert(lss);

        co_obj_t *obj_1018 = co_dev_find_obj(lss->dev, 0x1018);
        struct can_msg req;

        switch (cs) {
        case 0x46:
                // Check the vendor-ID.
                if (id != co_obj_get_val_u32(obj_1018, 0x01)) {
                        lss->cs = 0;
                        return;
                }
                lss->cs = 0x47;
                break;
        case 0x47:
                // Check the product-code.
                if (cs != lss->cs || id != co_obj_get_val_u32(obj_1018, 0x02)) {
                        lss->cs = 0;
                        return;
                }
                lss->cs = 0x48;
                break;
        case 0x48:
                // Check the lower bound of the revision-number.
                if (cs != lss->cs || id > co_obj_get_val_u32(obj_1018, 0x03)) {
                        lss->cs = 0;
                        return;
                }
                lss->cs = 0x49;
                break;
        case 0x49:
                // Check the upper bound of the revision-number.
                if (cs != lss->cs || id < co_obj_get_val_u32(obj_1018, 0x03)) {
                        lss->cs = 0;
                        return;
                }
                lss->cs = 0x4a;
                break;
        case 0x4a:
                // Check the lower bound of the serial-number.
                if (cs != lss->cs || id > co_obj_get_val_u32(obj_1018, 0x04)) {
                        lss->cs = 0;
                        return;
                }
                lss->cs = 0x4b;
                break;
        case 0x4b:
                // Check the upper bound of the serial-number.
                if (cs != lss->cs || id < co_obj_get_val_u32(obj_1018, 0x04)) {
                        lss->cs = 0;
                        return;
                }
                lss->cs = 0;
                // Notify the master that it is a match.
                co_lss_init_req(lss, &req, 0x4f);
                can_net_send(lss->net, &req);
                break;
        }
}

static void
co_lss_id_non_cfg_slave(const co_lss_t *lss)
{
        assert(lss);

        // Check if both the active and the pending node-ID are invalid.
        if (co_dev_get_id(lss->dev) != 0xff || co_nmt_get_id(lss->nmt) != 0xff)
                return;

        // Check if the device is in the NMT state Initialization.
        switch (co_nmt_get_st(lss->nmt)) {
        case CO_NMT_ST_BOOTUP:
        case CO_NMT_ST_RESET_NODE:
        case CO_NMT_ST_RESET_COMM: break;
        default: return;
        }

        struct can_msg req;
        co_lss_init_req(lss, &req, 0x50);
        can_net_send(lss->net, &req);
}

static co_lss_state_t *
co_lss_fastscan(co_lss_t *lss, co_unsigned32_t id, co_unsigned8_t bitchk,
                co_unsigned8_t lsssub, co_unsigned8_t lssnext)
{
        assert(lss);

        co_obj_t *obj_1018 = co_dev_find_obj(lss->dev, 0x1018);
        struct can_msg req;
        co_lss_state_t *next = NULL;

        if (__unlikely(bitchk > 31 && bitchk != 0x80))
                return NULL;

        if (bitchk == 0x80) {
                lss->lsspos = 0;
        } else {
                if (lss->lsspos > 3 || lss->lsspos != lsssub)
                        return NULL;
                // Check if the unmasked bits of the specified IDNumber match.
                co_unsigned32_t pid[] = { co_obj_get_val_u32(obj_1018, 0x01),
                        co_obj_get_val_u32(obj_1018, 0x02),
                        co_obj_get_val_u32(obj_1018, 0x03),
                        co_obj_get_val_u32(obj_1018, 0x04) };
                if ((id ^ pid[lss->lsspos]) & ~((UINT32_C(1) << bitchk) - 1))
                        return NULL;
                lss->lsspos = lssnext;
                // If this was the final bit, switch to the configuration state.
                if (!bitchk && lss->lsspos < lsssub)
                        next = co_lss_cfg_state;
        }

        // Notify the master that it is a match.
        co_lss_init_req(lss, &req, 0x4f);
        can_net_send(lss->net, &req);

        return next;
}

static void
co_lss_init_req(const co_lss_t *lss, struct can_msg *msg, co_unsigned8_t cs)
{
        assert(lss);
        assert(msg);

        *msg = (struct can_msg)CAN_MSG_INIT;
        msg->id = CO_LSS_CANID(co_lss_is_master(lss));
        msg->len = CAN_MAX_LEN;
        msg->data[0] = cs;
}

#ifndef LELY_NO_CO_MASTER

static int
co_lss_send_switch_sel_req(const co_lss_t *lss, const struct co_id *id)
{
        assert(id);

        // Switch state selective (see Fig. 32 in CiA 305 version 3.0.0).
        struct can_msg req;
        co_lss_init_req(lss, &req, 0x40);
        stle_u32(req.data + 1, id->vendor_id);
        if (__unlikely(can_net_send(lss->net, &req) == -1))
                return -1;
        co_lss_init_req(lss, &req, 0x41);
        stle_u32(req.data + 1, id->product_code);
        if (__unlikely(can_net_send(lss->net, &req) == -1))
                return -1;
        co_lss_init_req(lss, &req, 0x42);
        stle_u32(req.data + 1, id->revision);
        if (__unlikely(can_net_send(lss->net, &req) == -1))
                return -1;
        co_lss_init_req(lss, &req, 0x43);
        stle_u32(req.data + 1, id->serial_nr);
        if (__unlikely(can_net_send(lss->net, &req) == -1))
                return -1;

        return 0;
}

static int
co_lss_send_id_slave_req(const co_lss_t *lss, const struct co_id *lo,
                const struct co_id *hi)
{
        assert(lo);
        assert(hi);

        // clang-format off
        if (__unlikely(lo->vendor_id != hi->vendor_id
                        || lo->product_code != hi->product_code)
                        || lo->revision > hi->revision
                        || lo->serial_nr > hi->serial_nr) {
                // clang-format on
                set_errnum(ERRNUM_INVAL);
                return -1;
        }

        // LSS identify remote slave (see Fig. 42 in CiA 305 version 3.0.0).
        struct can_msg req;
        co_lss_init_req(lss, &req, 0x46);
        stle_u32(req.data + 1, lo->vendor_id);
        if (__unlikely(can_net_send(lss->net, &req) == -1))
                return -1;
        co_lss_init_req(lss, &req, 0x47);
        stle_u32(req.data + 1, lo->product_code);
        if (__unlikely(can_net_send(lss->net, &req) == -1))
                return -1;
        co_lss_init_req(lss, &req, 0x48);
        stle_u32(req.data + 1, lo->revision);
        if (__unlikely(can_net_send(lss->net, &req) == -1))
                return -1;
        co_lss_init_req(lss, &req, 0x49);
        stle_u32(req.data + 1, hi->revision);
        if (__unlikely(can_net_send(lss->net, &req) == -1))
                return -1;
        co_lss_init_req(lss, &req, 0x4a);
        stle_u32(req.data + 1, lo->serial_nr);
        if (__unlikely(can_net_send(lss->net, &req) == -1))
                return -1;
        co_lss_init_req(lss, &req, 0x4b);
        stle_u32(req.data + 1, hi->serial_nr);
        if (__unlikely(can_net_send(lss->net, &req) == -1))
                return -1;

        return 0;
}

static int
co_lss_send_fastscan_req(const co_lss_t *lss, co_unsigned32_t id,
                co_unsigned8_t bitchk, co_unsigned8_t lsssub,
                co_unsigned8_t lssnext)
{
        // LSS Fastscan (see Fig. 46 in CiA 305 version 3.0.0).
        struct can_msg req;
        co_lss_init_req(lss, &req, 0x51);
        stle_u32(req.data + 1, id);
        req.data[5] = bitchk;
        req.data[6] = lsssub;
        req.data[7] = lssnext;
        return can_net_send(lss->net, &req);
}

static void
co_lss_init_ind(co_lss_t *lss, co_unsigned8_t cs)
{
        assert(lss);

        lss->cs = cs;
        lss->err = 0;
        lss->spec = 0;
        lss->lssid = 0;
        lss->nid = 0;

        can_recv_start(lss->recv, lss->net, CO_LSS_CANID(0), 0);
        can_timer_timeout(lss->timer, lss->net, lss->timeout);
}

#endif // !LELY_NO_CO_MASTER

#endif // !LELY_NO_CO_LSS