circuitpython/ports/samd/machine_dac.c

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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2017 Nick Moore
* Copyright (c) 2022 Robert Hammelrath
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <stdint.h>
#include "py/obj.h"
#include "py/runtime.h"
#include "py/mphal.h"
#include "sam.h"
#include "pin_af.h"
#include "modmachine.h"
typedef struct _dac_obj_t {
mp_obj_base_t base;
uint8_t id;
mp_hal_pin_obj_t gpio_id;
uint8_t vref;
} dac_obj_t;
STATIC dac_obj_t dac_obj[] = {
#if defined(MCU_SAMD21)
{{&machine_dac_type}, 0, PIN_PA02},
#elif defined(MCU_SAMD51)
{{&machine_dac_type}, 0, PIN_PA02},
{{&machine_dac_type}, 1, PIN_PA05},
#endif
};
Dac *const dac_bases[] = DAC_INSTS;
#if defined(MCU_SAMD21)
#define MAX_DAC_VALUE (1023)
#define DEFAULT_DAC_VREF (1)
#define MAX_DAC_VREF (2)
#elif defined(MCU_SAMD51)
// According to Errata 2.9.2, VDDANA as ref value is not available. However it worked
// in tests. So I keep the selection here but set the default to Aref, which is usually
// connected at the Board to VDDANA
static uint8_t dac_vref_table[] = {
DAC_CTRLB_REFSEL_INTREF_Val, DAC_CTRLB_REFSEL_VDDANA_Val,
DAC_CTRLB_REFSEL_VREFPU_Val, DAC_CTRLB_REFSEL_VREFPB_Val
};
#define MAX_DAC_VALUE (4095)
#define DEFAULT_DAC_VREF (2)
#define MAX_DAC_VREF (3)
static bool dac_init = false;
#endif
STATIC mp_obj_t dac_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw,
const mp_obj_t *all_args) {
enum { ARG_id, ARG_vref };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_id, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_vref, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = DEFAULT_DAC_VREF} },
};
// 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);
uint8_t id = args[ARG_id].u_int;
dac_obj_t *self = NULL;
if (0 <= id && id <= MP_ARRAY_SIZE(dac_obj)) {
self = &dac_obj[id];
} else {
mp_raise_ValueError(MP_ERROR_TEXT("invalid Pin for DAC"));
}
uint8_t vref = args[ARG_vref].u_int;
if (0 <= vref && vref <= MAX_DAC_VREF) {
self->vref = vref;
}
Dac *dac = dac_bases[0]; // Just one DAC
// Init DAC
#if defined(MCU_SAMD21)
// Configuration SAMD21
// Enable APBC clocks and PCHCTRL clocks; GCLK3 at 1 MHz
PM->APBCMASK.reg |= PM_APBCMASK_DAC;
GCLK->CLKCTRL.reg = GCLK_CLKCTRL_CLKEN | GCLK_CLKCTRL_GEN_GCLK3 | GCLK_CLKCTRL_ID_DAC;
while (GCLK->STATUS.bit.SYNCBUSY) {
}
// Reset DAC registers
dac->CTRLA.bit.SWRST = 1;
while (dac->CTRLA.bit.SWRST) {
}
dac->CTRLB.reg = DAC_CTRLB_EOEN | DAC_CTRLB_REFSEL(self->vref);
// Enable DAC and wait to be ready
dac->CTRLA.bit.ENABLE = 1;
while (dac->STATUS.bit.SYNCBUSY) {
}
#elif defined(MCU_SAMD51)
// Configuration SAMD51
// Enable APBD clocks and PCHCTRL clocks; GCLK3 at 8 MHz
dac_init = true;
MCLK->APBDMASK.reg |= MCLK_APBDMASK_DAC;
GCLK->PCHCTRL[DAC_GCLK_ID].reg = GCLK_PCHCTRL_GEN_GCLK3 | GCLK_PCHCTRL_CHEN;
// Reset DAC registers
dac->CTRLA.bit.SWRST = 1;
while (dac->CTRLA.bit.SWRST) {
}
dac->CTRLB.reg = DAC_CTRLB_REFSEL(dac_vref_table[self->vref]);
dac->DACCTRL[self->id].reg = DAC_DACCTRL_ENABLE | DAC_DACCTRL_REFRESH(2) | DAC_DACCTRL_CCTRL_CC12M;
// Enable DAC and wait to be ready
dac->CTRLA.bit.ENABLE = 1;
while (dac->SYNCBUSY.bit.ENABLE) {
}
#endif
// Set the port as given in self->gpio_id as DAC
mp_hal_set_pin_mux(self->gpio_id, ALT_FCT_DAC);
return MP_OBJ_FROM_PTR(self);
}
STATIC void dac_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
dac_obj_t *self = self_in;
mp_printf(print, "DAC(%u, Pin=%s, vref=%d)", self->id, pin_name(self->gpio_id), self->vref);
}
STATIC mp_obj_t dac_write(mp_obj_t self_in, mp_obj_t value_in) {
Dac *dac = dac_bases[0]; // Just one DAC
int value = mp_obj_get_int(value_in);
if (value < 0 || value > MAX_DAC_VALUE) {
mp_raise_ValueError(MP_ERROR_TEXT("value out of range"));
}
#if defined(MCU_SAMD21)
dac->DATA.reg = value;
#elif defined(MCU_SAMD51)
dac_obj_t *self = self_in;
dac->DATA[self->id].reg = value;
#endif
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_2(dac_write_obj, dac_write);
STATIC const mp_rom_map_elem_t dac_locals_dict_table[] = {
{ MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&dac_write_obj) },
};
STATIC MP_DEFINE_CONST_DICT(dac_locals_dict, dac_locals_dict_table);
MP_DEFINE_CONST_OBJ_TYPE(
machine_dac_type,
MP_QSTR_DAC,
MP_TYPE_FLAG_NONE,
make_new, dac_make_new,
print, dac_print,
locals_dict, &dac_locals_dict
);