circuitpython/ports/atmel-samd/common-hal/busio/SPI.c
Scott Shawcroft 1a0b4193b7
Simplify the status LED to save power
This also removes the need to pin share because we don't use the
status LED while user code is running.

The status flashes fallback to the HW_STATUS LED if no RGB LED is
present. Each status has a unique blink pattern as well.

One caveat is the REPL state. In order to not pin share, we set the
RGB color once. PWM and single color will be shutoff immediately but
DotStars and NeoPixels will hold the color until the user overrides
it.

Fixes #4133
2021-05-13 14:41:20 -07:00

356 lines
12 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2016 Scott Shawcroft
*
* 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 "shared-bindings/busio/SPI.h"
#include "py/mperrno.h"
#include "py/runtime.h"
#include "hpl_sercom_config.h"
#include "peripheral_clk_config.h"
#include "supervisor/board.h"
#include "common-hal/microcontroller/Pin.h"
#include "hal/include/hal_gpio.h"
#include "hal/include/hal_spi_m_sync.h"
#include "hal/include/hpl_spi_m_sync.h"
#include "samd/dma.h"
#include "samd/sercom.h"
bool never_reset_sercoms[SERCOM_INST_NUM];
void never_reset_sercom(Sercom *sercom) {
// Reset all SERCOMs except the ones being used by on-board devices.
Sercom *sercom_instances[SERCOM_INST_NUM] = SERCOM_INSTS;
for (int i = 0; i < SERCOM_INST_NUM; i++) {
if (sercom_instances[i] == sercom) {
never_reset_sercoms[i] = true;
break;
}
}
}
void allow_reset_sercom(Sercom *sercom) {
// Reset all SERCOMs except the ones being used by on-board devices.
Sercom *sercom_instances[SERCOM_INST_NUM] = SERCOM_INSTS;
for (int i = 0; i < SERCOM_INST_NUM; i++) {
if (sercom_instances[i] == sercom) {
never_reset_sercoms[i] = false;
break;
}
}
}
void reset_sercoms(void) {
// Reset all SERCOMs except the ones being used by on-board devices.
Sercom *sercom_instances[SERCOM_INST_NUM] = SERCOM_INSTS;
for (int i = 0; i < SERCOM_INST_NUM; i++) {
if (never_reset_sercoms[i]) {
continue;
}
// SWRST is same for all modes of SERCOMs.
sercom_instances[i]->SPI.CTRLA.bit.SWRST = 1;
}
}
void common_hal_busio_spi_construct(busio_spi_obj_t *self,
const mcu_pin_obj_t *clock, const mcu_pin_obj_t *mosi,
const mcu_pin_obj_t *miso) {
Sercom *sercom = NULL;
uint8_t sercom_index;
uint32_t clock_pinmux = 0;
bool mosi_none = mosi == NULL;
bool miso_none = miso == NULL;
uint32_t mosi_pinmux = 0;
uint32_t miso_pinmux = 0;
uint8_t clock_pad = 0;
uint8_t mosi_pad = 0;
uint8_t miso_pad = 0;
uint8_t dopo = 255;
// Special case for SAMR21 boards. (feather_radiofruit_zigbee)
#if defined(PIN_PC19F_SERCOM4_PAD0)
if (miso == &pin_PC19) {
if (mosi == &pin_PB30 && clock == &pin_PC18) {
sercom = SERCOM4;
sercom_index = 4;
clock_pinmux = MUX_F;
mosi_pinmux = MUX_F;
miso_pinmux = MUX_F;
clock_pad = 3;
mosi_pad = 2;
miso_pad = 0;
dopo = samd_peripherals_get_spi_dopo(clock_pad, mosi_pad);
}
// Error, leave SERCOM unset to throw an exception later.
} else
#endif
{
for (int i = 0; i < NUM_SERCOMS_PER_PIN; i++) {
sercom_index = clock->sercom[i].index; // 2 for SERCOM2, etc.
if (sercom_index >= SERCOM_INST_NUM) {
continue;
}
Sercom *potential_sercom = sercom_insts[sercom_index];
if (potential_sercom->SPI.CTRLA.bit.ENABLE != 0) {
continue;
}
clock_pinmux = PINMUX(clock->number, (i == 0) ? MUX_C : MUX_D);
clock_pad = clock->sercom[i].pad;
if (!samd_peripherals_valid_spi_clock_pad(clock_pad)) {
continue;
}
for (int j = 0; j < NUM_SERCOMS_PER_PIN; j++) {
if (!mosi_none) {
if (sercom_index == mosi->sercom[j].index) {
mosi_pinmux = PINMUX(mosi->number, (j == 0) ? MUX_C : MUX_D);
mosi_pad = mosi->sercom[j].pad;
dopo = samd_peripherals_get_spi_dopo(clock_pad, mosi_pad);
if (dopo > 0x3) {
continue; // pad combination not possible
}
if (miso_none) {
sercom = potential_sercom;
break;
}
} else {
continue;
}
}
if (!miso_none) {
for (int k = 0; k < NUM_SERCOMS_PER_PIN; k++) {
if (sercom_index == miso->sercom[k].index) {
miso_pinmux = PINMUX(miso->number, (k == 0) ? MUX_C : MUX_D);
miso_pad = miso->sercom[k].pad;
sercom = potential_sercom;
break;
}
}
}
if (sercom != NULL) {
break;
}
}
if (sercom != NULL) {
break;
}
}
}
if (sercom == NULL) {
mp_raise_ValueError(translate("Invalid pins"));
}
// Set up SPI clocks on SERCOM.
samd_peripherals_sercom_clock_init(sercom, sercom_index);
if (spi_m_sync_init(&self->spi_desc, sercom) != ERR_NONE) {
mp_raise_OSError(MP_EIO);
}
// Pads must be set after spi_m_sync_init(), which uses default values from
// the prototypical SERCOM.
hri_sercomspi_write_CTRLA_DOPO_bf(sercom, dopo);
hri_sercomspi_write_CTRLA_DIPO_bf(sercom, miso_pad);
// Always start at 250khz which is what SD cards need. They are sensitive to
// SPI bus noise before they are put into SPI mode.
uint8_t baud_value = samd_peripherals_spi_baudrate_to_baud_reg_value(250000);
if (spi_m_sync_set_baudrate(&self->spi_desc, baud_value) != ERR_NONE) {
// spi_m_sync_set_baudrate does not check for validity, just whether the device is
// busy or not
mp_raise_OSError(MP_EIO);
}
gpio_set_pin_direction(clock->number, GPIO_DIRECTION_OUT);
gpio_set_pin_pull_mode(clock->number, GPIO_PULL_OFF);
gpio_set_pin_function(clock->number, clock_pinmux);
claim_pin(clock);
self->clock_pin = clock->number;
if (mosi_none) {
self->MOSI_pin = NO_PIN;
} else {
gpio_set_pin_direction(mosi->number, GPIO_DIRECTION_OUT);
gpio_set_pin_pull_mode(mosi->number, GPIO_PULL_OFF);
gpio_set_pin_function(mosi->number, mosi_pinmux);
self->MOSI_pin = mosi->number;
claim_pin(mosi);
}
if (miso_none) {
self->MISO_pin = NO_PIN;
} else {
gpio_set_pin_direction(miso->number, GPIO_DIRECTION_IN);
gpio_set_pin_pull_mode(miso->number, GPIO_PULL_OFF);
gpio_set_pin_function(miso->number, miso_pinmux);
self->MISO_pin = miso->number;
claim_pin(miso);
}
spi_m_sync_enable(&self->spi_desc);
}
void common_hal_busio_spi_never_reset(busio_spi_obj_t *self) {
never_reset_sercom(self->spi_desc.dev.prvt);
never_reset_pin_number(self->clock_pin);
never_reset_pin_number(self->MOSI_pin);
never_reset_pin_number(self->MISO_pin);
}
bool common_hal_busio_spi_deinited(busio_spi_obj_t *self) {
return self->clock_pin == NO_PIN;
}
void common_hal_busio_spi_deinit(busio_spi_obj_t *self) {
if (common_hal_busio_spi_deinited(self)) {
return;
}
allow_reset_sercom(self->spi_desc.dev.prvt);
spi_m_sync_disable(&self->spi_desc);
spi_m_sync_deinit(&self->spi_desc);
reset_pin_number(self->clock_pin);
reset_pin_number(self->MOSI_pin);
reset_pin_number(self->MISO_pin);
self->clock_pin = NO_PIN;
}
bool common_hal_busio_spi_configure(busio_spi_obj_t *self,
uint32_t baudrate, uint8_t polarity, uint8_t phase, uint8_t bits) {
uint8_t baud_reg_value = samd_peripherals_spi_baudrate_to_baud_reg_value(baudrate);
void *hw = self->spi_desc.dev.prvt;
// If the settings are already what we want then don't reset them.
if (hri_sercomspi_get_CTRLA_CPHA_bit(hw) == phase &&
hri_sercomspi_get_CTRLA_CPOL_bit(hw) == polarity &&
hri_sercomspi_read_CTRLB_CHSIZE_bf(hw) == ((uint32_t)bits - 8) &&
hri_sercomspi_read_BAUD_BAUD_bf(hw) == baud_reg_value) {
return true;
}
// Disable, set values (most or all are enable-protected), and re-enable.
spi_m_sync_disable(&self->spi_desc);
hri_sercomspi_wait_for_sync(hw, SERCOM_SPI_SYNCBUSY_MASK);
hri_sercomspi_write_CTRLA_CPHA_bit(hw, phase);
hri_sercomspi_write_CTRLA_CPOL_bit(hw, polarity);
hri_sercomspi_write_CTRLB_CHSIZE_bf(hw, bits - 8);
hri_sercomspi_write_BAUD_BAUD_bf(hw, baud_reg_value);
hri_sercomspi_wait_for_sync(hw, SERCOM_SPI_SYNCBUSY_MASK);
spi_m_sync_enable(&self->spi_desc);
hri_sercomspi_wait_for_sync(hw, SERCOM_SPI_SYNCBUSY_MASK);
return true;
}
bool common_hal_busio_spi_try_lock(busio_spi_obj_t *self) {
bool grabbed_lock = false;
CRITICAL_SECTION_ENTER()
if (!self->has_lock) {
grabbed_lock = true;
self->has_lock = true;
}
CRITICAL_SECTION_LEAVE();
return grabbed_lock;
}
bool common_hal_busio_spi_has_lock(busio_spi_obj_t *self) {
return self->has_lock;
}
void common_hal_busio_spi_unlock(busio_spi_obj_t *self) {
self->has_lock = false;
}
bool common_hal_busio_spi_write(busio_spi_obj_t *self,
const uint8_t *data, size_t len) {
if (len == 0) {
return true;
}
int32_t status;
if (len >= 16) {
status = sercom_dma_write(self->spi_desc.dev.prvt, data, len);
} else {
struct io_descriptor *spi_io;
spi_m_sync_get_io_descriptor(&self->spi_desc, &spi_io);
status = spi_io->write(spi_io, data, len);
}
return status >= 0; // Status is number of chars read or an error code < 0.
}
bool common_hal_busio_spi_read(busio_spi_obj_t *self,
uint8_t *data, size_t len, uint8_t write_value) {
if (len == 0) {
return true;
}
int32_t status;
if (len >= 16) {
status = sercom_dma_read(self->spi_desc.dev.prvt, data, len, write_value);
} else {
self->spi_desc.dev.dummy_byte = write_value;
struct io_descriptor *spi_io;
spi_m_sync_get_io_descriptor(&self->spi_desc, &spi_io);
status = spi_io->read(spi_io, data, len);
}
return status >= 0; // Status is number of chars read or an error code < 0.
}
bool common_hal_busio_spi_transfer(busio_spi_obj_t *self, const uint8_t *data_out, uint8_t *data_in, size_t len) {
if (len == 0) {
return true;
}
int32_t status;
if (len >= 16) {
status = sercom_dma_transfer(self->spi_desc.dev.prvt, data_out, data_in, len);
} else {
struct spi_xfer xfer;
xfer.txbuf = (uint8_t *)data_out;
xfer.rxbuf = data_in;
xfer.size = len;
status = spi_m_sync_transfer(&self->spi_desc, &xfer);
}
return status >= 0; // Status is number of chars read or an error code < 0.
}
uint32_t common_hal_busio_spi_get_frequency(busio_spi_obj_t *self) {
return samd_peripherals_spi_baud_reg_value_to_baudrate(hri_sercomspi_read_BAUD_reg(self->spi_desc.dev.prvt));
}
uint8_t common_hal_busio_spi_get_phase(busio_spi_obj_t *self) {
void *hw = self->spi_desc.dev.prvt;
return hri_sercomspi_get_CTRLA_CPHA_bit(hw);
}
uint8_t common_hal_busio_spi_get_polarity(busio_spi_obj_t *self) {
void *hw = self->spi_desc.dev.prvt;
return hri_sercomspi_get_CTRLA_CPOL_bit(hw);
}