espurna-sonoff-pow/espurna/pwm.c
2018-06-06 15:28:17 +02:00

448 lines
11 KiB
C
Executable File

/*
* Copyright (C) 2016 Stefan Brüns <stefan.bruens@rwth-aachen.de>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/* Set the following three defines to your needs */
#ifndef SDK_PWM_PERIOD_COMPAT_MODE
#define SDK_PWM_PERIOD_COMPAT_MODE 0
#endif
#ifndef PWM_MAX_CHANNELS
#define PWM_MAX_CHANNELS 8
#endif
#define PWM_DEBUG 0
#define PWM_USE_NMI 1
/* no user servicable parts beyond this point */
#define PWM_MAX_TICKS 0x7fffff
#if SDK_PWM_PERIOD_COMPAT_MODE
#define PWM_PERIOD_TO_TICKS(x) (x * 0.2)
#define PWM_DUTY_TO_TICKS(x) (x * 5)
#define PWM_MAX_DUTY (PWM_MAX_TICKS * 0.2)
#define PWM_MAX_PERIOD (PWM_MAX_TICKS * 5)
#else
#define PWM_PERIOD_TO_TICKS(x) (x)
#define PWM_DUTY_TO_TICKS(x) (x)
#define PWM_MAX_DUTY PWM_MAX_TICKS
#define PWM_MAX_PERIOD PWM_MAX_TICKS
#endif
#include <c_types.h>
#include <pwm.h>
#include <eagle_soc.h>
#include <ets_sys.h>
// from SDK hw_timer.c
#define TIMER1_DIVIDE_BY_16 0x0004
#define TIMER1_ENABLE_TIMER 0x0080
struct pwm_phase {
uint32_t ticks; ///< delay until next phase, in 200ns units
uint16_t on_mask; ///< GPIO mask to switch on
uint16_t off_mask; ///< GPIO mask to switch off
};
/* Three sets of PWM phases, the active one, the one used
* starting with the next cycle, and the one updated
* by pwm_start. After the update pwm_next_set
* is set to the last updated set. pwm_current_set is set to
* pwm_next_set from the interrupt routine during the first
* pwm phase
*/
typedef struct pwm_phase (pwm_phase_array)[PWM_MAX_CHANNELS + 2];
static pwm_phase_array pwm_phases[3];
static struct {
struct pwm_phase* next_set;
struct pwm_phase* current_set;
uint8_t current_phase;
} pwm_state;
static uint32_t pwm_period;
static uint32_t pwm_period_ticks;
static uint32_t pwm_duty[PWM_MAX_CHANNELS];
static uint16_t gpio_mask[PWM_MAX_CHANNELS];
static uint8_t pwm_channels;
// 3-tuples of MUX_REGISTER, MUX_VALUE and GPIO number
typedef uint32_t (pin_info_type)[3];
struct gpio_regs {
uint32_t out; /* 0x60000300 */
uint32_t out_w1ts; /* 0x60000304 */
uint32_t out_w1tc; /* 0x60000308 */
uint32_t enable; /* 0x6000030C */
uint32_t enable_w1ts; /* 0x60000310 */
uint32_t enable_w1tc; /* 0x60000314 */
uint32_t in; /* 0x60000318 */
uint32_t status; /* 0x6000031C */
uint32_t status_w1ts; /* 0x60000320 */
uint32_t status_w1tc; /* 0x60000324 */
};
static struct gpio_regs* gpio = (struct gpio_regs*)(0x60000300);
struct timer_regs {
uint32_t frc1_load; /* 0x60000600 */
uint32_t frc1_count; /* 0x60000604 */
uint32_t frc1_ctrl; /* 0x60000608 */
uint32_t frc1_int; /* 0x6000060C */
uint8_t pad[16];
uint32_t frc2_load; /* 0x60000620 */
uint32_t frc2_count; /* 0x60000624 */
uint32_t frc2_ctrl; /* 0x60000628 */
uint32_t frc2_int; /* 0x6000062C */
uint32_t frc2_alarm; /* 0x60000630 */
};
static struct timer_regs* timer = (struct timer_regs*)(0x60000600);
static void ICACHE_RAM_ATTR
pwm_intr_handler(void)
{
if ((pwm_state.current_set[pwm_state.current_phase].off_mask == 0) &&
(pwm_state.current_set[pwm_state.current_phase].on_mask == 0)) {
pwm_state.current_set = pwm_state.next_set;
pwm_state.current_phase = 0;
}
do {
// force write to GPIO registers on each loop
asm volatile ("" : : : "memory");
gpio->out_w1ts = (uint32_t)(pwm_state.current_set[pwm_state.current_phase].on_mask);
gpio->out_w1tc = (uint32_t)(pwm_state.current_set[pwm_state.current_phase].off_mask);
uint32_t ticks = pwm_state.current_set[pwm_state.current_phase].ticks;
pwm_state.current_phase++;
if (ticks) {
if (ticks >= 16) {
// constant interrupt overhead
ticks -= 9;
timer->frc1_int &= ~FRC1_INT_CLR_MASK;
WRITE_PERI_REG(&timer->frc1_load, ticks);
return;
}
ticks *= 4;
do {
ticks -= 1;
// stop compiler from optimizing delay loop to noop
asm volatile ("" : : : "memory");
} while (ticks > 0);
}
} while (1);
}
/**
* period: initial period (base unit 1us OR 200ns)
* duty: array of initial duty values, may be NULL, may be freed after pwm_init
* pwm_channel_num: number of channels to use
* pin_info_list: array of pin_info
*/
void ICACHE_FLASH_ATTR
pwm_init(uint32_t period, uint32_t *duty, uint32_t pwm_channel_num,
uint32_t (*pin_info_list)[3])
{
int i, j, n;
pwm_channels = pwm_channel_num;
if (pwm_channels > PWM_MAX_CHANNELS)
pwm_channels = PWM_MAX_CHANNELS;
for (i = 0; i < 3; i++) {
for (j = 0; j < (PWM_MAX_CHANNELS + 2); j++) {
pwm_phases[i][j].ticks = 0;
pwm_phases[i][j].on_mask = 0;
pwm_phases[i][j].off_mask = 0;
}
}
pwm_state.current_set = pwm_state.next_set = 0;
pwm_state.current_phase = 0;
uint32_t all = 0;
// PIN info: MUX-Register, Mux-Setting, PIN-Nr
for (n = 0; n < pwm_channels; n++) {
pin_info_type* pin_info = &pin_info_list[n];
PIN_FUNC_SELECT((*pin_info)[0], (*pin_info)[1]);
gpio_mask[n] = 1 << (*pin_info)[2];
all |= 1 << (*pin_info)[2];
if (duty)
pwm_set_duty(duty[n], n);
}
GPIO_REG_WRITE(GPIO_OUT_W1TC_ADDRESS, all);
GPIO_REG_WRITE(GPIO_ENABLE_W1TS_ADDRESS, all);
pwm_set_period(period);
#if PWM_USE_NMI
ETS_FRC_TIMER1_NMI_INTR_ATTACH(pwm_intr_handler);
#else
ETS_FRC_TIMER1_INTR_ATTACH(pwm_intr_handler, NULL);
#endif
TM1_EDGE_INT_ENABLE();
timer->frc1_int &= ~FRC1_INT_CLR_MASK;
timer->frc1_ctrl = 0;
pwm_start();
}
__attribute__ ((noinline))
static uint8_t ICACHE_FLASH_ATTR
_pwm_phases_prep(struct pwm_phase* pwm)
{
uint8_t n, phases;
for (n = 0; n < pwm_channels + 2; n++) {
pwm[n].ticks = 0;
pwm[n].on_mask = 0;
pwm[n].off_mask = 0;
}
phases = 1;
for (n = 0; n < pwm_channels; n++) {
uint32_t ticks = PWM_DUTY_TO_TICKS(pwm_duty[n]);
if (ticks == 0) {
pwm[0].off_mask |= gpio_mask[n];
} else if (ticks >= pwm_period_ticks) {
pwm[0].on_mask |= gpio_mask[n];
} else {
if (ticks < (pwm_period_ticks/2)) {
pwm[phases].ticks = ticks;
pwm[0].on_mask |= gpio_mask[n];
pwm[phases].off_mask = gpio_mask[n];
} else {
pwm[phases].ticks = pwm_period_ticks - ticks;
pwm[phases].on_mask = gpio_mask[n];
pwm[0].off_mask |= gpio_mask[n];
}
phases++;
}
}
pwm[phases].ticks = pwm_period_ticks;
// bubble sort, lowest to hightest duty
n = 2;
while (n < phases) {
if (pwm[n].ticks < pwm[n - 1].ticks) {
struct pwm_phase t = pwm[n];
pwm[n] = pwm[n - 1];
pwm[n - 1] = t;
if (n > 2)
n--;
} else {
n++;
}
}
#if PWM_DEBUG
int t = 0;
for (t = 0; t <= phases; t++) {
ets_printf("%d @%d: %04x %04x\n", t, pwm[t].ticks, pwm[t].on_mask, pwm[t].off_mask);
}
#endif
// shift left to align right edge;
uint8_t l = 0, r = 1;
while (r <= phases) {
uint32_t diff = pwm[r].ticks - pwm[l].ticks;
if (diff && (diff <= 16)) {
uint16_t mask = pwm[r].on_mask | pwm[r].off_mask;
pwm[l].off_mask ^= pwm[r].off_mask;
pwm[l].on_mask ^= pwm[r].on_mask;
pwm[0].off_mask ^= pwm[r].on_mask;
pwm[0].on_mask ^= pwm[r].off_mask;
pwm[r].ticks = pwm_period_ticks - diff;
pwm[r].on_mask ^= mask;
pwm[r].off_mask ^= mask;
} else {
l = r;
}
r++;
}
#if PWM_DEBUG
for (t = 0; t <= phases; t++) {
ets_printf("%d @%d: %04x %04x\n", t, pwm[t].ticks, pwm[t].on_mask, pwm[t].off_mask);
}
#endif
// sort again
n = 2;
while (n <= phases) {
if (pwm[n].ticks < pwm[n - 1].ticks) {
struct pwm_phase t = pwm[n];
pwm[n] = pwm[n - 1];
pwm[n - 1] = t;
if (n > 2)
n--;
} else {
n++;
}
}
// merge same duty
l = 0, r = 1;
while (r <= phases) {
if (pwm[r].ticks == pwm[l].ticks) {
pwm[l].off_mask |= pwm[r].off_mask;
pwm[l].on_mask |= pwm[r].on_mask;
pwm[r].on_mask = 0;
pwm[r].off_mask = 0;
} else {
l++;
if (l != r) {
struct pwm_phase t = pwm[l];
pwm[l] = pwm[r];
pwm[r] = t;
}
}
r++;
}
phases = l;
#if PWM_DEBUG
for (t = 0; t <= phases; t++) {
ets_printf("%d @%d: %04x %04x\n", t, pwm[t].ticks, pwm[t].on_mask, pwm[t].off_mask);
}
#endif
// transform absolute end time to phase durations
for (n = 0; n < phases; n++) {
pwm[n].ticks =
pwm[n + 1].ticks - pwm[n].ticks;
// subtract common overhead
pwm[n].ticks--;
}
pwm[phases].ticks = 0;
// do a cyclic shift if last phase is short
if (pwm[phases - 1].ticks < 16) {
for (n = 0; n < phases - 1; n++) {
struct pwm_phase t = pwm[n];
pwm[n] = pwm[n + 1];
pwm[n + 1] = t;
}
}
#if PWM_DEBUG
for (t = 0; t <= phases; t++) {
ets_printf("%d +%d: %04x %04x\n", t, pwm[t].ticks, pwm[t].on_mask, pwm[t].off_mask);
}
ets_printf("\n");
#endif
return phases;
}
void ICACHE_FLASH_ATTR
pwm_start(void)
{
pwm_phase_array* pwm = &pwm_phases[0];
if ((*pwm == pwm_state.next_set) ||
(*pwm == pwm_state.current_set))
pwm++;
if ((*pwm == pwm_state.next_set) ||
(*pwm == pwm_state.current_set))
pwm++;
uint8_t phases = _pwm_phases_prep(*pwm);
// all with 0% / 100% duty - stop timer
if (phases == 1) {
if (pwm_state.next_set) {
#if PWM_DEBUG
ets_printf("PWM stop\n");
#endif
timer->frc1_ctrl = 0;
ETS_FRC1_INTR_DISABLE();
}
pwm_state.next_set = NULL;
GPIO_REG_WRITE(GPIO_OUT_W1TS_ADDRESS, (*pwm)[0].on_mask);
GPIO_REG_WRITE(GPIO_OUT_W1TC_ADDRESS, (*pwm)[0].off_mask);
return;
}
// start if not running
if (!pwm_state.next_set) {
#if PWM_DEBUG
ets_printf("PWM start\n");
#endif
pwm_state.current_set = pwm_state.next_set = *pwm;
pwm_state.current_phase = phases - 1;
ETS_FRC1_INTR_ENABLE();
RTC_REG_WRITE(FRC1_LOAD_ADDRESS, 0);
timer->frc1_ctrl = TIMER1_DIVIDE_BY_16 | TIMER1_ENABLE_TIMER;
return;
}
pwm_state.next_set = *pwm;
}
void ICACHE_FLASH_ATTR
pwm_set_duty(uint32_t duty, uint8_t channel)
{
if (channel > PWM_MAX_CHANNELS)
return;
if (duty > PWM_MAX_DUTY)
duty = PWM_MAX_DUTY;
pwm_duty[channel] = duty;
}
uint32_t ICACHE_FLASH_ATTR
pwm_get_duty(uint8_t channel)
{
if (channel > PWM_MAX_CHANNELS)
return 0;
return pwm_duty[channel];
}
void ICACHE_FLASH_ATTR
pwm_set_period(uint32_t period)
{
pwm_period = period;
if (pwm_period > PWM_MAX_PERIOD)
pwm_period = PWM_MAX_PERIOD;
pwm_period_ticks = PWM_PERIOD_TO_TICKS(period);
}
uint32_t ICACHE_FLASH_ATTR
pwm_get_period(void)
{
return pwm_period;
}
uint32_t ICACHE_FLASH_ATTR
get_pwm_version(void)
{
return 1;
}
void ICACHE_FLASH_ATTR
set_pwm_debug_en(uint8_t print_en)
{
(void) print_en;
}