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samd/machine_pwm: Add init() method to PWM and simplify the PWM code. 

The PWM.init() method has been added.  Calling init() without arguments
restarts a PWM channel stopped with deinit().  Otherwise single parameters
except for "device=n" can be changed again.  The device can only be
specified once, either in the constructor or the first init() call.

Also simplify get_pwm_config() and get_adc_config(), and shrink the PWM
object.
This commit is contained in:
robert-hh 2023-02-24 14:51:36 +01:00 committed by Damien George
parent 9c7ad68165
commit 250757716a
4 changed files with 118 additions and 136 deletions
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2
docs/samd/quickref.rst
View File

@ -191,7 +191,7 @@ It supports all basic methods listed for that class. ::
PWM Constructor
```````````````
.. class:: PWM(dest, freq, duty_u16, duty_ns, *, invert, device)
.. class:: PWM(dest, *, freq, duty_u16, duty_ns, invert, device)
:noindex:
Construct and return a new PWM object using the following parameters:

219
ports/samd/machine_pwm.c
View File

@ -40,15 +40,14 @@
typedef struct _machine_pwm_obj_t {
mp_obj_base_t base;
Tcc *instance;
bool defer_start;
uint8_t pin_id;
uint8_t alt_fct;
uint8_t device;
int8_t device;
uint8_t channel;
uint8_t output;
uint16_t prescaler;
uint32_t period; // full period count ticks
uint32_t duty_ns; // just for reporting
uint16_t duty_u16; // just for reporting
int32_t freq; // for re-init.
} machine_pwm_obj_t;
#define PWM_NOT_INIT (0)
@ -58,6 +57,8 @@ typedef struct _machine_pwm_obj_t {
#define PWM_FULL_SCALE (65536)
#define PWM_UPDATE_TIMEOUT (2000)
#define VALUE_NOT_SET (-1)
static Tcc *tcc_instance[] = TCC_INSTS;
#if defined(MCU_SAMD21)
@ -104,10 +105,12 @@ static uint8_t device_status[TCC_INST_NUM];
static uint8_t output_active[TCC_INST_NUM];
const uint16_t prescaler_table[] = {1, 2, 4, 8, 16, 64, 256, 1024};
STATIC void pwm_stop_device(int device);
STATIC void mp_machine_pwm_freq_set(machine_pwm_obj_t *self, mp_int_t freq);
STATIC void mp_machine_pwm_duty_set_u16(machine_pwm_obj_t *self, mp_int_t duty_u16);
STATIC void mp_machine_pwm_duty_set_ns(machine_pwm_obj_t *self, mp_int_t duty_ns);
STATIC void mp_machine_pwm_start(machine_pwm_obj_t *self);
STATIC void mp_machine_pwm_stop(machine_pwm_obj_t *self);
STATIC void mp_machine_pwm_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
machine_pwm_obj_t *self = MP_OBJ_TO_PTR(self_in);
@ -115,48 +118,39 @@ STATIC void mp_machine_pwm_print(const mp_print_t *print, mp_obj_t self_in, mp_p
pin_name(self->pin_id), self->device, self->channel, self->output);
}
// PWM(pin)
STATIC mp_obj_t mp_machine_pwm_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
enum { ARG_pin, ARG_freq, ARG_duty_u16, ARG_duty_ns, ARG_invert, ARG_device };
// called by the constructor and init()
STATIC void mp_machine_pwm_init_helper(machine_pwm_obj_t *self,
size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_freq, ARG_duty_u16, ARG_duty_ns, ARG_invert, ARG_device };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_pin, MP_ARG_REQUIRED | MP_ARG_OBJ },
{ MP_QSTR_freq, MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_duty_u16, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_duty_ns, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_invert, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_device, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_duty_u16, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = VALUE_NOT_SET} },
{ MP_QSTR_duty_ns, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = VALUE_NOT_SET} },
{ MP_QSTR_invert, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = VALUE_NOT_SET} },
{ MP_QSTR_device, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = VALUE_NOT_SET} },
};
// Parse the arguments.
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
mp_arg_parse_all(n_args, pos_args, kw_args,
MP_ARRAY_SIZE(allowed_args), allowed_args, args);
// Get GPIO and optional device to connect to PWM.
uint32_t pin_id = mp_hal_get_pin_obj(args[ARG_pin].u_obj);
int32_t wanted_dev = args[ARG_device].u_int; // -1 = any
// Get the peripheral object and populate it
pwm_config_t config = get_pwm_config(pin_id, wanted_dev, device_status);
uint8_t device = config.device_channel >> 4;
if (device >= TCC_INST_NUM) {
mp_raise_ValueError(MP_ERROR_TEXT("wrong device"));
int8_t device = self->device;
if (device == VALUE_NOT_SET) { // Device not set, just get & set
int32_t wanted_dev = args[ARG_device].u_int; // -1 = any
pwm_config_t config = get_pwm_config(self->pin_id, wanted_dev, device_status);
device = config.device_channel >> 4;
self->instance = tcc_instance[device];
self->device = device;
self->alt_fct = config.alt_fct;
self->channel = (config.device_channel & 0x0f) % tcc_channel_count[device];
self->output = config.device_channel & 0x0f;
put_duty_value(device, self->channel, 0);
}
machine_pwm_obj_t *self = mp_obj_malloc(machine_pwm_obj_t, &machine_pwm_type);
self->instance = tcc_instance[device];
self->device = device;
self->pin_id = pin_id;
self->alt_fct = config.alt_fct;
self->channel = (config.device_channel & 0x0f) % tcc_channel_count[device];
self->output = config.device_channel & 0x0f;
self->prescaler = 1;
self->period = 1; // Use an invalid but safe value
self->duty_u16 = self->duty_ns = 0;
put_duty_value(self->device, self->channel, 0);
Tcc *tcc = self->instance;
// Initialize the hardware if needed
if (device_status[device] == PWM_NOT_INIT) {
// Enable the device clock at first use.
#if defined(MCU_SAMD21)
@ -203,10 +197,11 @@ STATIC mp_obj_t mp_machine_pwm_make_new(const mp_obj_type_t *type, size_t n_args
device_status[device] = PWM_CLK_READY;
}
if (args[ARG_invert].u_int != -1) {
self->defer_start = true;
if (args[ARG_invert].u_int != VALUE_NOT_SET) {
bool invert = !!args[ARG_invert].u_int;
if (device_status[device] != PWM_CLK_READY) {
pwm_stop_device(device);
mp_machine_pwm_stop(self);
}
uint32_t mask = 1 << (self->output + TCC_DRVCTRL_INVEN0_Pos);
if (invert) {
@ -215,24 +210,47 @@ STATIC mp_obj_t mp_machine_pwm_make_new(const mp_obj_type_t *type, size_t n_args
tcc->DRVCTRL.reg &= ~(mask);
}
}
if (args[ARG_duty_u16].u_int != -1) {
mp_machine_pwm_duty_set_u16(self, args[ARG_duty_u16].u_int);
}
if (args[ARG_duty_ns].u_int != -1) {
mp_machine_pwm_duty_set_ns(self, args[ARG_duty_ns].u_int);
}
if (args[ARG_freq].u_int != -1) {
if (args[ARG_freq].u_int != VALUE_NOT_SET) {
mp_machine_pwm_freq_set(self, args[ARG_freq].u_int);
}
if (args[ARG_duty_u16].u_int != VALUE_NOT_SET) {
mp_machine_pwm_duty_set_u16(self, args[ARG_duty_u16].u_int);
}
if (args[ARG_duty_ns].u_int != VALUE_NOT_SET) {
mp_machine_pwm_duty_set_ns(self, args[ARG_duty_ns].u_int);
}
self->defer_start = false;
// Start the PWM if properly set.
mp_machine_pwm_start(self);
}
// PWM(pin)
STATIC mp_obj_t mp_machine_pwm_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
// Check number of arguments
mp_arg_check_num(n_args, n_kw, 1, MP_OBJ_FUN_ARGS_MAX, true);
// Get the peripheral object and populate it
machine_pwm_obj_t *self = mp_obj_malloc(machine_pwm_obj_t, &machine_pwm_type);
self->pin_id = mp_hal_get_pin_obj(args[0]);
self->device = VALUE_NOT_SET;
self->prescaler = 1;
self->freq = VALUE_NOT_SET;
// Process the remaining parameters.
mp_map_t kw_args;
mp_map_init_fixed_table(&kw_args, n_kw, args + n_args);
mp_machine_pwm_init_helper(self, n_args - 1, args + 1, &kw_args);
return MP_OBJ_FROM_PTR(self);
}
STATIC void pwm_stop_device(int device) {
Tcc *tcc = tcc_instance[device];
STATIC void mp_machine_pwm_stop(machine_pwm_obj_t *self) {
Tcc *tcc = tcc_instance[self->device];
tcc->CTRLA.bit.ENABLE = 0;
while (tcc->SYNCBUSY.reg & TCC_SYNCBUSY_ENABLE) {
}
device_status[device] = PWM_CLK_READY;
device_status[self->device] = PWM_CLK_READY;
}
// Stop all TTC devices
@ -252,13 +270,13 @@ void pwm_deinit_all(void) {
// Switch off an output. If all outputs of a device are off,
// switch off that device.
// This stops all channels, but keeps the configuration
// Calling pwm.freq(n) will start an instance again.
// Calling pwm.freq(n), pwm.duty_x() or pwm.init() will start it again.
STATIC void mp_machine_pwm_deinit(machine_pwm_obj_t *self) {
mp_hal_clr_pin_mux(self->pin_id); // Switch the output off
output_active[self->device] &= ~(1 << self->output); // clear output flasg
// Stop the device, if no output is active.
if (output_active[self->device] == 0) {
pwm_stop_device(self->device);
mp_machine_pwm_stop(self);
}
}
@ -275,80 +293,52 @@ STATIC void wait_for_register_update(Tcc *tcc) {
tcc->INTFLAG.reg = TCC_INTFLAG_OVF;
}
STATIC mp_obj_t mp_machine_pwm_freq_get(machine_pwm_obj_t *self) {
if (self->instance->CTRLA.reg & TCC_CTRLA_ENABLE) {
return MP_OBJ_NEW_SMALL_INT(PWM_MASTER_CLK / self->prescaler / self->period);
} else {
return MP_OBJ_NEW_SMALL_INT(0);
}
}
STATIC void mp_machine_pwm_freq_set(machine_pwm_obj_t *self, mp_int_t freq) {
// Set the frequency. The period counter is 24 bit or 16 bit with a pre-scaling
STATIC void mp_machine_pwm_start(machine_pwm_obj_t *self) {
// Start the PWM. The period counter is 24 bit or 16 bit with a pre-scaling
// of up to 1024, allowing a range from 24 MHz down to 1 Hz.
static const uint32_t max_period[5] = {1 << 24, 1 << 24, 1 << 16, 1 << 16, 1 << 16};
Tcc *tcc = self->instance;
if (freq < 1) {
pwm_stop_device(self->device);
if (self->freq < 1 || self->defer_start == true) {
return;
}
// Get the actual settings of prescaler & period from the unit
// To be able for cope for changes.
uint32_t prev_period = tcc->PER.reg + 1;
Tcc *tcc = self->instance;
// Check for the right prescaler
uint8_t index;
for (index = 0; index < 8; index++) {
uint32_t temp = PWM_MASTER_CLK / prescaler_table[index] / freq;
uint32_t temp = PWM_MASTER_CLK / prescaler_table[index] / self->freq;
if (temp < max_period[self->device]) {
break;
}
}
self->prescaler = prescaler_table[index];
uint32_t period = PWM_MASTER_CLK / self->prescaler / freq;
uint32_t period = PWM_MASTER_CLK / self->prescaler / self->freq;
if (period < 2) {
mp_raise_ValueError(MP_ERROR_TEXT("freq too large"));
}
// If the PWM is running, ensure that a cycle has passed since the
// previous setting before setting a new frequency/duty value
// previous setting before setting frequency and duty.
if (tcc->CTRLA.reg & TCC_CTRLA_ENABLE) {
wait_for_register_update(tcc);
}
// Check, if the prescaler has to be changed and stop the device if so.
if (index != tcc->CTRLA.bit.PRESCALER) {
// stop the device
pwm_stop_device(self->device);
// update the prescaler
mp_machine_pwm_stop(self);
tcc->CTRLA.bit.PRESCALER = index;
}
// Lock the update to get a glitch-free change of period and duty cycle
tcc->CTRLBSET.reg = TCC_CTRLBSET_LUPD;
tcc->PERBUF.reg = period - 1;
self->period = period;
// Check if the Duty rate has to be aligned again when freq or prescaler were changed.
// This condition is as well true on first call after instantiation. So (re-)configure
// all channels with a duty_u16 setting.
if (period != prev_period) {
for (uint16_t ch = 0; ch < tcc_channel_count[self->device]; ch++) {
if ((duty_type_flags[self->device] & (1 << ch)) != 0) { // duty_u16 type?
tcc->CCBUF[ch].reg = (uint64_t)get_duty_value(self->device, ch) * period /
PWM_FULL_SCALE;
}
}
}
// If the prescaler was changed, the device is disabled. So this condition is true
// after the instantiation and after a prescaler change.
// (re-)configure all channels with a duty_ns setting.
if (!(tcc->CTRLA.reg & TCC_CTRLA_ENABLE)) {
for (uint16_t ch = 0; ch < tcc_channel_count[self->device]; ch++) {
if ((duty_type_flags[self->device] & (1 << ch)) == 0) { // duty_ns type?
tcc->CCBUF[ch].reg = (uint64_t)get_duty_value(self->device, ch) * PWM_MASTER_CLK /
self->prescaler / 1000000000ULL;
}
// (re-) configure the duty type settings.
for (uint16_t ch = 0; ch < tcc_channel_count[self->device]; ch++) {
if ((duty_type_flags[self->device] & (1 << ch)) != 0) { // duty_u16 type?
tcc->CCBUF[ch].reg = (uint64_t)get_duty_value(self->device, ch) * period /
PWM_FULL_SCALE;
} else { // duty_ns type
tcc->CCBUF[ch].reg = (uint64_t)get_duty_value(self->device, ch) * PWM_MASTER_CLK /
self->prescaler / 1000000000ULL;
}
}
// Remember the output as active.
@ -367,38 +357,39 @@ STATIC void mp_machine_pwm_freq_set(machine_pwm_obj_t *self, mp_int_t freq) {
tcc->CTRLBCLR.reg = TCC_CTRLBCLR_LUPD;
}
STATIC mp_obj_t mp_machine_pwm_freq_get(machine_pwm_obj_t *self) {
return MP_OBJ_NEW_SMALL_INT(self->freq);
}
STATIC void mp_machine_pwm_freq_set(machine_pwm_obj_t *self, mp_int_t freq) {
self->freq = freq;
mp_machine_pwm_start(self);
}
STATIC mp_obj_t mp_machine_pwm_duty_get_u16(machine_pwm_obj_t *self) {
return MP_OBJ_NEW_SMALL_INT(self->duty_u16);
if (duty_type_flags[self->device] & (1 << self->channel)) {
return MP_OBJ_NEW_SMALL_INT(get_duty_value(self->device, self->channel));
} else {
return MP_OBJ_NEW_SMALL_INT(-1);
}
}
STATIC void mp_machine_pwm_duty_set_u16(machine_pwm_obj_t *self, mp_int_t duty_u16) {
// Remember the values for update & reporting
put_duty_value(self->device, self->channel, duty_u16);
self->duty_u16 = duty_u16;
self->duty_ns = 0;
// If the device is enabled, than the period is set and we get a reasonable value for
// the duty cycle, set to the CCBUF register. Otherwise, PWM does not start.
if (self->instance->CTRLA.reg & TCC_CTRLA_ENABLE) {
// Ensure that a cycle has passed updating the registers
// since the previous setting before setting a new duty value
wait_for_register_update(self->instance);
self->instance->CCBUF[self->channel].reg = (uint64_t)duty_u16 * (self->period) / PWM_FULL_SCALE;
}
duty_type_flags[self->device] |= 1 << self->channel;
mp_machine_pwm_start(self);
}
STATIC mp_obj_t mp_machine_pwm_duty_get_ns(machine_pwm_obj_t *self) {
return MP_OBJ_NEW_SMALL_INT(self->duty_ns);
if (!(duty_type_flags[self->device] & (1 << self->channel))) {
return MP_OBJ_NEW_SMALL_INT(get_duty_value(self->device, self->channel));
} else {
return MP_OBJ_NEW_SMALL_INT(-1);
}
}
STATIC void mp_machine_pwm_duty_set_ns(machine_pwm_obj_t *self, mp_int_t duty_ns) {
// Remember the values for update & reporting
put_duty_value(self->device, self->channel, duty_ns);
self->duty_ns = duty_ns;
self->duty_u16 = 0;
// Ensure that a cycle has passed updating the registers
// since the previous setting before setting a new duty value
wait_for_register_update(self->instance);
self->instance->CCBUF[self->channel].reg = (uint64_t)duty_ns * PWM_MASTER_CLK / self->prescaler / 1000000000ULL;
duty_type_flags[self->device] &= ~(1 << self->channel);
mp_machine_pwm_start(self);
}

2
ports/samd/mpconfigport.h
View File

@ -107,7 +107,7 @@
#define MICROPY_PY_MACHINE_BITSTREAM (1)
#define MICROPY_PY_MACHINE_PULSE (1)
#define MICROPY_PY_MACHINE_PWM (1)
#define MICROPY_PY_MACHINE_PWM_INIT (0)
#define MICROPY_PY_MACHINE_PWM_INIT (1)
#define MICROPY_PY_MACHINE_PWM_DUTY_U16_NS (1)
#define MICROPY_PY_MACHINE_PWM_INCLUDEFILE "ports/samd/machine_pwm.c"
#define MICROPY_PY_MACHINE_PIN_MAKE_NEW mp_pin_make_new

31
ports/samd/pin_af.c
View File

@ -142,11 +142,6 @@ sercom_pad_config_t get_sercom_config(int pin_id, uint8_t sercom_nr) {
adc_config_t get_adc_config(int pin_id, int32_t flag) {
const machine_pin_obj_t *pct_ptr = get_pin_obj_ptr(pin_id);
#if defined(MCU_SAMD51)
if (pct_ptr->adc1 != 0xff && (flag & (1 << (pct_ptr->adc1 + 16))) == 0) {
return (adc_config_t) {1, pct_ptr->adc1};
} else
#endif
if (pct_ptr->adc0 != 0xff && (flag & (1 << pct_ptr->adc0)) == 0) {
return (adc_config_t) {0, pct_ptr->adc0};
#if defined(MUC_SAMD51)
@ -174,26 +169,22 @@ pwm_config_t get_pwm_config(int pin_id, int wanted_dev, uint8_t device_status[])
return (pwm_config_t) {ALT_FCT_TCC1, tcc1};
} else if ((tcc2 >> 4) == wanted_dev) {
return (pwm_config_t) {ALT_FCT_TCC2, tcc2};
} else {
mp_raise_ValueError(MP_ERROR_TEXT("wrong device or channel"));
}
} else {
pwm_config_t ret = {};
// Try to get a unused PWM device at the pin
if (((tcc1 >> 4) < TCC_INST_NUM) && (device_status[tcc1 >> 4] == 0)) {
return (pwm_config_t) {ALT_FCT_TCC1, tcc1};
}
if (((tcc2 >> 4) < TCC_INST_NUM) && (device_status[tcc2 >> 4] == 0)) {
return (pwm_config_t) {ALT_FCT_TCC2, tcc2};
}
// If all devices are used, return one from the pin if available
if ((tcc1 >> 4) < TCC_INST_NUM) {
ret = (pwm_config_t) {ALT_FCT_TCC1, tcc1};
if (tcc2 == 0xff) {
return ret;
}
return (pwm_config_t) {ALT_FCT_TCC1, tcc1};
}
if ((tcc2 >> 4) < TCC_INST_NUM) {
// if a device in slot 1 is not available or already in use, use the one in slot 2
if (tcc1 == 0xff || device_status[(ret.device_channel >> 4)] != 0) {
return (pwm_config_t) {ALT_FCT_TCC2, tcc2};
} else {
return ret;
}
} else {
mp_raise_ValueError(MP_ERROR_TEXT("not a PWM pin"));
return (pwm_config_t) {ALT_FCT_TCC2, tcc2};
}
}
mp_raise_ValueError(MP_ERROR_TEXT("not a PWM Pin"));
}