samd/modmachine: Implement machine.lightsleep().

Which just sets the CPU clock to 200kHz and switches the peripheral clock
off.  There are two modes:

    machine.lightsleep(duration_ms)

and

    machine.lightsleep()

In any mode any configured pin.irq() event will terminate the sleep.

Current consumption in lightsleep for some boards:
- 1.5 - 2.5 mA when supplied trough an active USB
  (Seeed XIAO w/o power LED, Adafruit ItsyBitsy)
- 0.8 - 2 mA when supplied through Gnd/+5V (Vusb)
  (Seeed XIAO w/o power LED, Adafruit ItsyBitsy)
- < 1 mA for SAMD51 when supplied trough a battery connector
  (Sparkfun Thing SAMD51 plus)

Related change: move the calls to SysTick_Config() into set_cpu_freq().  It
is required after each CPU freq change to have ticks_ms run at the proper
rate.
This commit is contained in:
robert-hh 2022-08-01 17:23:11 +02:00 committed by Damien George
parent 4c9e4c3310
commit 03075a6839
5 changed files with 65 additions and 2 deletions

View File

@ -57,6 +57,8 @@ typedef struct _machine_pin_irq_obj_t {
STATIC const mp_irq_methods_t machine_pin_irq_methods;
bool EIC_occured;
uint32_t machine_pin_open_drain_mask[4];
// Open drain behaviour is simulated.
@ -410,6 +412,7 @@ void EIC_Handler() {
for (int eic_id = 0; eic_id < 16; eic_id++, mask <<= 1) {
// Did the ISR fire?
if (isr & mask) {
EIC_occured = true;
EIC->INTFLAG.reg |= mask; // clear the ISR flag
machine_pin_irq_obj_t *irq = MP_STATE_PORT(machine_pin_irq_objects[eic_id]);
if (irq != NULL) {

View File

@ -81,6 +81,7 @@ void set_cpu_freq(uint32_t cpu_freq_arg) {
}
// Set 0 waitstates for slower CPU clock
NVMCTRL->CTRLB.reg = NVMCTRL_CTRLB_MANW | NVMCTRL_CTRLB_RWS(cpu_freq > 24000000 ? 1 : 0);
SysTick_Config(cpu_freq / 1000);
}
void check_usb_recovery_mode(void) {

View File

@ -112,6 +112,7 @@ void set_cpu_freq(uint32_t cpu_freq_arg) {
while (GCLK->SYNCBUSY.bit.GENCTRL5) {
}
}
SysTick_Config(cpu_freq / 1000);
}
void check_usb_recovery_mode(void) {

View File

@ -50,6 +50,10 @@
#define DBL_TAP_MAGIC_LOADER 0xf01669ef
#define DBL_TAP_MAGIC_RESET 0xf02669ef
#define LIGHTSLEEP_CPU_FREQ 200000
extern bool EIC_occured;
STATIC mp_obj_t machine_reset(void) {
*DBL_TAP_ADDR = DBL_TAP_MAGIC_RESET;
NVIC_SystemReset();
@ -71,7 +75,6 @@ STATIC mp_obj_t machine_freq(size_t n_args, const mp_obj_t *args) {
uint32_t freq = mp_obj_get_int(args[0]);
if (freq >= 1000000 && freq <= MAX_CPU_FREQ) {
set_cpu_freq(freq);
SysTick_Config(get_cpu_freq() / 1000);
}
return mp_const_none;
}
@ -151,6 +154,60 @@ STATIC mp_obj_t machine_reset_cause(void) {
}
MP_DEFINE_CONST_FUN_OBJ_0(machine_reset_cause_obj, machine_reset_cause);
STATIC mp_obj_t machine_lightsleep(size_t n_args, const mp_obj_t *args) {
int32_t duration = -1;
uint32_t freq = get_cpu_freq();
if (n_args > 0) {
duration = mp_obj_get_int(args[0]);
}
EIC_occured = false;
// Slow down
set_cpu_freq(LIGHTSLEEP_CPU_FREQ);
#if defined(MCU_SAMD21)
// Switch the peripheral clock off
GCLK->GENCTRL.reg = GCLK_GENCTRL_ID(2);
while (GCLK->STATUS.bit.SYNCBUSY) {
}
// Switch the EIC temporarily to GCLK3, since GCLK2 is off
GCLK->CLKCTRL.reg = GCLK_CLKCTRL_CLKEN | GCLK_CLKCTRL_GEN_GCLK3 | EIC_GCLK_ID;
if (duration > 0) {
uint32_t t0 = systick_ms;
while ((systick_ms - t0 < duration) && (EIC_occured == false)) {
__WFI();
}
} else {
while (EIC_occured == false) {
__WFI();
}
}
GCLK->CLKCTRL.reg = GCLK_CLKCTRL_CLKEN | GCLK_CLKCTRL_GEN_GCLK2 | EIC_GCLK_ID;
#elif defined(MCU_SAMD51)
// Switch the peripheral clock off
GCLK->GENCTRL[2].reg = 0;
while (GCLK->SYNCBUSY.bit.GENCTRL2) {
}
// Switch the EIC temporarily to GCLK3, since GCLK2 is off
GCLK->PCHCTRL[EIC_GCLK_ID].reg = GCLK_PCHCTRL_CHEN | GCLK_PCHCTRL_GEN_GCLK3;
if (duration > 0) {
uint32_t t0 = systick_ms;
while ((systick_ms - t0 < duration) && (EIC_occured == false)) {
__WFI();
}
} else {
while (EIC_occured == false) {
__WFI();
}
}
GCLK->PCHCTRL[EIC_GCLK_ID].reg = GCLK_PCHCTRL_CHEN | GCLK_PCHCTRL_GEN_GCLK2;
#endif
// Speed up again
set_cpu_freq(freq);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_lightsleep_obj, 0, 1, machine_lightsleep);
STATIC const mp_rom_map_elem_t machine_module_globals_table[] = {
{ MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_umachine) },
{ MP_ROM_QSTR(MP_QSTR_reset), MP_ROM_PTR(&machine_reset_obj) },
@ -179,6 +236,8 @@ STATIC const mp_rom_map_elem_t machine_module_globals_table[] = {
{ MP_ROM_QSTR(MP_QSTR_enable_irq), MP_ROM_PTR(&machine_enable_irq_obj) },
{ MP_ROM_QSTR(MP_QSTR_reset_cause), MP_ROM_PTR(&machine_reset_cause_obj) },
{ MP_ROM_QSTR(MP_QSTR_time_pulse_us), MP_ROM_PTR(&machine_time_pulse_us_obj) },
{ MP_ROM_QSTR(MP_QSTR_lightsleep), MP_ROM_PTR(&machine_lightsleep_obj) },
{ MP_ROM_QSTR(MP_QSTR_bitstream), MP_ROM_PTR(&machine_bitstream_obj) },
#if MICROPY_PY_MACHINE_DHT_READINTO
{ MP_ROM_QSTR(MP_QSTR_dht_readinto), MP_ROM_PTR(&dht_readinto_obj) },

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@ -108,7 +108,6 @@ void init_us_counter(void) {
void samd_init(void) {
init_clocks(get_cpu_freq());
SysTick_Config(get_cpu_freq() / 1000);
init_us_counter();
usb_init();
check_usb_recovery_mode();