contiki/platform/stepper-robot/stepper/stepper-interrupt.c

297 lines
7.8 KiB
C
Raw Normal View History

#include <stepper-interrupt.h>
#include <interrupt-utils.h>
#include <stdio.h>
#include <stepper.h>
StepperContext stepper_context;
static void
do_step(StepperTimerStep *step)
{
const uint32_t *io_steps;
StepperState *state = step->state;
if (step->power >= STEPPER_POWER_ACC) {
io_steps = state->acc_steps;
} else if (step->power >= STEPPER_POWER_RUN) {
io_steps = state->run_steps;
} else {
io_steps = state->hold_steps;
}
if (io_steps) {
if (step->direction == STEPPER_DIRECTION_FORWARD){
state->step_count++;
/* dbg_putchar('+'); */
if (++state->current_step == state->sequence_length)
state->current_step = 0;
} else {
state->step_count--;
/* dbg_putchar('-'); */
if (state->current_step-- == 0)
state->current_step = state->sequence_length-1;
}
*AT91C_PIOA_ODSR = (*AT91C_PIOA_ODSR & ~state->io_mask)
| (io_steps[state->current_step] & state->io_mask);
#ifdef TIMING_ERRORS
{
long err = ((long)stepper_context.timer_channel->TC_CV - (long)step->time);
if (err >= (TIMER_FREQ/PPS/2)) {
err -= TIMER_FREQ/PPS;
} else if (err < -(TIMER_FREQ/PPS/2)) {
err += TIMER_FREQ/PPS;
}
if (err < state->err_min) state->err_min = err;
if (err > state->err_max) state->err_max = err;
}
#endif
}
}
static void
set_hold(StepperState *state) {
*AT91C_PIOA_ODSR = (*AT91C_PIOA_ODSR & ~state->io_mask)
| (state->hold_steps[state->current_step] & state->io_mask);
}
static void
advance_step()
{
StepperTimerStep *current =stepper_context.current_step;
AT91PS_TC timer = stepper_context.timer_channel;
unsigned int now = timer->TC_CV;
while (current && current->time <= now) {
do_step(current);
current = current->next;
if (!current) break;
timer->TC_RA = current->time;
now = timer->TC_CV;
}
stepper_context.current_step = current;
}
static inline int64_t
mulsu48_16(int64_t a, uint32_t b)
{
return a*(int64_t)b;
}
/* Find a solution for s = a*t*t +v * t in the interval [t_low, t_high[ */
static unsigned long
solve_dist(long long s, long a, long long v, unsigned long t_low, unsigned long t_high)
{
long long s_low = mulsu48_16((a*(long)t_low+ v), t_low);
long long s_high = mulsu48_16((a*(long)t_high + v), t_high);
if (s >= s_low && s <= s_high) {
while(t_low + 2 < t_high) {
unsigned long t = (t_high + t_low) / 2;
long long s_mid = mulsu48_16((a*(long)t + v), t);
if (s < s_mid) {
t_high = t;
s_high = s_mid;
} else {
t_low = t;
s_low = s_mid;
}
}
} else {
while(t_low + 1 < t_high) {
unsigned long t = (t_high + t_low) / 2;
long long s_mid = mulsu48_16((a*(long)t + v), t);
if (s > s_mid) {
t_high = t;
s_high = s_mid;
} else {
t_low = t;
s_low = s_mid;
}
}
}
return (t_high + t_low) / 2;
}
#define HEAP_SIZE 65
static StepperTimerStep step_heap[2][HEAP_SIZE];
static unsigned short heap_pos = 0; /* Next free position in heap */
static unsigned char current_heap = 0;
static StepperTimerStep *
allocate_step()
{
if (heap_pos >= HEAP_SIZE) return NULL;
return &step_heap[current_heap][heap_pos++];
}
static void
switch_step_heap()
{
current_heap ^= 1;
heap_pos = 0;
}
StepperTimerStep **
insert_step(StepperTimerStep **at, StepperState *state,
unsigned int time, uint8_t direction, uint8_t power)
{
StepperTimerStep *new_step;
while(*at && (*at)->time <= time) {
at = &(*at)->next;
}
new_step = allocate_step();
if (!new_step) return at;
new_step->next = *at;
new_step->state = state;
new_step->time = time;
new_step->direction = direction;
new_step->power = power;
*at = new_step;
/* dbg_putchar('!'); */
return &new_step->next;
}
/* Determine suitable power for the current state */
static uint8_t
get_power(StepperState *state)
{
if (state->acceleration != 0) return STEPPER_POWER_ACC;
if (state->velocity == 0) return STEPPER_POWER_HOLD;
return STEPPER_POWER_RUN;
}
#define SQ(x) ((x)*(x))
#define S_SCALING ((2LL*SQ((long long)TIMER_FREQ)) / DIST_SCALE )
#define V_SCALING (2LL*TIMER_FREQ/VEL_SCALE)
static void
step_interval(StepperState *state)
{
unsigned int i;
long long v = state->velocity * V_SCALING;
long long a = state->acceleration;
unsigned long t = 0;
StepperTimerStep **at = &stepper_context.steps;
if (state->n_steps >= 0) {
long long s = -state->step_frac * S_SCALING;
for (i = 0; i < state->n_steps; i++) {
s+= DIST_SCALE * S_SCALING;
t = solve_dist(s, a, v, t, TIMER_FREQ/PPS);
/* printf("F%ld\n", t); */
at = insert_step(at, state, t, STEPPER_DIRECTION_FORWARD, get_power(state));
}
} else {
long long s = (DIST_SCALE - state->step_frac) * S_SCALING;
for (i = 0; i < -state->n_steps; i++) {
s-= DIST_SCALE * S_SCALING;
t = solve_dist(s, a, v, t, TIMER_FREQ/PPS);
/* printf("B%ld\n", t); */
at = insert_step(at, state, t, STEPPER_DIRECTION_BACKWARD, get_power(state));
}
}
}
static void
setup_speed(StepperState *state)
{
long steps;
long step_frac;
/* printf("%ld v= %ld s=%ld\n",stepper_context.period_count, */
/* state->velocity, state->step_frac); */
step_frac = (state->acceleration + 2 * state->velocity
+ state->step_frac);
steps = step_frac / DIST_SCALE;
step_frac -= steps * DIST_SCALE;
if (step_frac <0) {
step_frac += DIST_SCALE;
steps--;
}
/* printf("step_frac=%ld (%f) steps=%ld\n",step_frac, */
/* (double)step_frac/(double)(DIST_SCALE), steps); */
state->n_steps = steps;
step_interval(state);
state->velocity += state->acceleration;
state->step_frac = step_frac;
state->step_full += steps;
}
static void
advance_period()
{
unsigned int s;
StepperTimerStep *current =stepper_context.current_step;
/* Do any remaining step */
while (current) {
do_step(current);
current = current->next;
}
/* Start from the beginning */
stepper_context.current_step = stepper_context.steps;
stepper_context.steps = NULL;
if (stepper_context.current_step) {
stepper_context.timer_channel->TC_RA = stepper_context.current_step->time;
} else {
stepper_context.timer_channel->TC_RA = 0xffff;
}
/* In case there is a step very early in the period */
advance_step();
stepper_context.period_count++;
*AT91C_AIC_EOICR = 0;
for(s = 0; s < NUM_STEPPERS; s++) {
StepperState *state = &stepper_context.steppers[s];
StepperAccSeq *acc_seq;
if (state->acceleration == 0 && state->velocity == 0) {
/* Set hold power if stationary */
stepper_context.timer_channel->TC_IDR = AT91C_TC_CPCS | AT91C_TC_CPAS;
set_hold(state);
stepper_context.timer_channel->TC_IER = AT91C_TC_CPCS | AT91C_TC_CPAS;
}
while ((acc_seq = state->acceleration_sequence)
&& acc_seq->period == stepper_context.period_count + 1) {
state->acceleration_sequence = acc_seq->next;
if (acc_seq->acceleration == STEPPER_ACC_INVALID) {
if (stepper_context.user_callback) {
stepper_context.user_callback(s, stepper_context.period_count);
}
} else {
state->acceleration = acc_seq->acceleration;
}
acc_seq->next = NULL; /* Only free this one */
stepper_free_seq(acc_seq);
}
setup_speed(&stepper_context.steppers[s]);
}
/* Prepare heap for next period */
switch_step_heap();
}
/* Here we have a proper stack frame and can use local variables */
static void stepper_int_safe() __attribute((noinline));
static void
stepper_int_safe()
{
unsigned int status;
status = stepper_context.timer_channel->TC_SR;
if (status & AT91C_TC_CPAS) {
advance_step();
/* dbg_putchar('*'); */
}
if (status & AT91C_TC_CPCS) {
advance_period();
} else {
*AT91C_AIC_EOICR = 0; /* End of Interrupt */
}
}
void NACKEDFUNC stepper_timer_interrupt (void) {
ISR_STORE();
ISR_ENABLE_NEST();
stepper_int_safe();
ISR_DISABLE_NEST();
ISR_RESTORE();
}