circuitpython/ports/atmel-samd/common-hal/busio/SPI.c

342 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 "shared-bindings/microcontroller/Pin.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/busio/__init__.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"
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, bool half_duplex) {
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;
if (half_duplex) {
mp_raise_NotImplementedError(translate("Half duplex SPI is not implemented"));
}
// Ensure the object starts in its deinit state.
self->clock_pin = NO_PIN;
// 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) {
raise_ValueError_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) {
size_t bytes_remaining = len;
// Maximum DMA transfer is 65535
while (1) {
size_t to_send = (bytes_remaining > 65535) ? 65535 : bytes_remaining;
status = sercom_dma_write(self->spi_desc.dev.prvt, data + (len - bytes_remaining), to_send);
bytes_remaining -= to_send;
if (bytes_remaining > 0) {
// Multi-part transfer; let other things run before doing the next chunk.
RUN_BACKGROUND_TASKS;
} else {
// All done.
break;
}
}
} 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);
}