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circuitpython/ports/stm/common-hal/busio/I2C.c

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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2016 Scott Shawcroft
* Copyright (c) 2019 Lucian Copeland for Adafruit Industries
*
* 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 <stdbool.h>
#include "shared-bindings/busio/I2C.h"
#include "py/mperrno.h"
#include "py/runtime.h"
#include "shared-bindings/microcontroller/__init__.h"
#include "supervisor/shared/translate.h"
#include "shared-bindings/microcontroller/Pin.h"
// I2C timing specs for the H7 and F7
// Configured for maximum possible clock settings for the family
#if (CPY_STM32F7)
#ifndef CPY_I2CFAST_TIMINGR
#define CPY_I2CFAST_TIMINGR 0x6000030D
#endif
#ifndef CPY_I2CSTANDARD_TIMINGR
#define CPY_I2CSTANDARD_TIMINGR 0x20404768
#endif
#elif (CPY_STM32H7)
#ifndef CPY_I2CFAST_TIMINGR
#define CPY_I2CFAST_TIMINGR 0x00B03FDB
#endif
#ifndef CPY_I2CSTANDARD_TIMINGR
#define CPY_I2CSTANDARD_TIMINGR 0x307075B1
#endif
#elif (CPY_STM32L4)
#ifndef CPY_I2CFAST_TIMINGR
#define CPY_I2CFAST_TIMINGR 0x00B03FDB
#endif
#ifndef CPY_I2CSTANDARD_TIMINGR
#define CPY_I2CSTANDARD_TIMINGR 0x307075B1
#endif
#endif
// Arrays use 0 based numbering: I2C1 is stored at index 0
#define MAX_I2C 4
STATIC bool reserved_i2c[MAX_I2C];
STATIC bool never_reset_i2c[MAX_I2C];
#define ALL_CLOCKS 0xFF
STATIC void i2c_clock_enable(uint8_t mask);
STATIC void i2c_clock_disable(uint8_t mask);
STATIC void i2c_assign_irq(busio_i2c_obj_t *self, I2C_TypeDef *I2Cx);
void i2c_reset(void) {
uint16_t never_reset_mask = 0x00;
for (int i = 0; i < MAX_I2C; i++) {
if (!never_reset_i2c[i]) {
reserved_i2c[i] = false;
} else {
never_reset_mask |= 1 << i;
}
}
i2c_clock_disable(ALL_CLOCKS & ~(never_reset_mask));
}
void common_hal_busio_i2c_construct(busio_i2c_obj_t *self,
const mcu_pin_obj_t *scl, const mcu_pin_obj_t *sda, uint32_t frequency, uint32_t timeout) {
// Match pins to I2C objects
I2C_TypeDef *I2Cx;
uint8_t sda_len = MP_ARRAY_SIZE(mcu_i2c_sda_list);
uint8_t scl_len = MP_ARRAY_SIZE(mcu_i2c_scl_list);
bool i2c_taken = false;
for (uint i = 0; i < sda_len; i++) {
if (mcu_i2c_sda_list[i].pin == sda) {
for (uint j = 0; j < scl_len; j++) {
if ((mcu_i2c_scl_list[j].pin == scl)
&& (mcu_i2c_scl_list[j].periph_index == mcu_i2c_sda_list[i].periph_index)) {
// Keep looking if the I2C is taken, could be another SCL that works
if (reserved_i2c[mcu_i2c_scl_list[j].periph_index - 1]) {
i2c_taken = true;
continue;
}
self->scl = &mcu_i2c_scl_list[j];
self->sda = &mcu_i2c_sda_list[i];
break;
}
}
if (self->scl != NULL) {
// Multi-level break to pick lowest peripheral
break;
}
}
}
// Handle typedef selection, errors
if (self->sda != NULL && self->scl != NULL) {
I2Cx = mcu_i2c_banks[self->sda->periph_index - 1];
} else {
if (i2c_taken) {
mp_raise_ValueError(translate("Hardware busy, try alternative pins"));
} else {
mp_raise_ValueError_varg(translate("Invalid %q pin selection"), MP_QSTR_I2C);
}
}
// Start GPIO for each pin
GPIO_InitTypeDef GPIO_InitStruct = {0};
GPIO_InitStruct.Pin = pin_mask(sda->number);
GPIO_InitStruct.Mode = GPIO_MODE_AF_OD;
GPIO_InitStruct.Pull = GPIO_PULLUP;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
GPIO_InitStruct.Alternate = self->sda->altfn_index;
HAL_GPIO_Init(pin_port(sda->port), &GPIO_InitStruct);
GPIO_InitStruct.Pin = pin_mask(scl->number);
GPIO_InitStruct.Mode = GPIO_MODE_AF_OD;
GPIO_InitStruct.Pull = GPIO_PULLUP;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
GPIO_InitStruct.Alternate = self->scl->altfn_index;
HAL_GPIO_Init(pin_port(scl->port), &GPIO_InitStruct);
// Note: due to I2C soft reboot issue, do not relocate clock init.
i2c_clock_enable(1 << (self->sda->periph_index - 1));
reserved_i2c[self->sda->periph_index - 1] = true;
// Create root pointer and assign IRQ
MP_STATE_PORT(cpy_i2c_obj_all)[self->sda->periph_index - 1] = self;
i2c_assign_irq(self, I2Cx);
// Handle the HAL handle differences
#if (CPY_STM32H7 || CPY_STM32F7 || CPY_STM32L4)
if (frequency == 400000) {
self->handle.Init.Timing = CPY_I2CFAST_TIMINGR;
} else if (frequency == 100000) {
self->handle.Init.Timing = CPY_I2CSTANDARD_TIMINGR;
} else {
mp_raise_ValueError(translate("Unsupported baudrate"));
}
#else
self->handle.Init.ClockSpeed = frequency;
self->handle.Init.DutyCycle = I2C_DUTYCYCLE_2;
#endif
self->handle.Instance = I2Cx;
self->handle.Init.OwnAddress1 = 0;
self->handle.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
self->handle.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
self->handle.Init.OwnAddress2 = 0;
self->handle.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
self->handle.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;
self->handle.State = HAL_I2C_STATE_RESET;
if (HAL_I2C_Init(&(self->handle)) != HAL_OK) {
mp_raise_RuntimeError(translate("I2C Init Error"));
}
common_hal_mcu_pin_claim(sda);
common_hal_mcu_pin_claim(scl);
self->frame_in_prog = false;
// start the receive interrupt chain
HAL_NVIC_DisableIRQ(self->irq); // prevent handle lock contention
HAL_NVIC_SetPriority(self->irq, 1, 0);
HAL_NVIC_EnableIRQ(self->irq);
}
void common_hal_busio_i2c_never_reset(busio_i2c_obj_t *self) {
for (size_t i = 0; i < MP_ARRAY_SIZE(mcu_i2c_banks); i++) {
if (self->handle.Instance == mcu_i2c_banks[i]) {
never_reset_i2c[i] = true;
never_reset_pin_number(self->scl->pin->port, self->scl->pin->number);
never_reset_pin_number(self->sda->pin->port, self->sda->pin->number);
break;
}
}
}
bool common_hal_busio_i2c_deinited(busio_i2c_obj_t *self) {
return self->sda == NULL;
}
void common_hal_busio_i2c_deinit(busio_i2c_obj_t *self) {
if (common_hal_busio_i2c_deinited(self)) {
return;
}
i2c_clock_disable(1 << (self->sda->periph_index - 1));
reserved_i2c[self->sda->periph_index - 1] = false;
never_reset_i2c[self->sda->periph_index - 1] = false;
reset_pin_number(self->sda->pin->port,self->sda->pin->number);
reset_pin_number(self->scl->pin->port,self->scl->pin->number);
self->sda = NULL;
self->scl = NULL;
}
bool common_hal_busio_i2c_probe(busio_i2c_obj_t *self, uint8_t addr) {
return HAL_I2C_IsDeviceReady(&(self->handle), (uint16_t)(addr << 1), 2, 2) == HAL_OK;
}
bool common_hal_busio_i2c_try_lock(busio_i2c_obj_t *self) {
bool grabbed_lock = false;
// Critical section code that may be required at some point.
// uint32_t store_primask = __get_PRIMASK();
// __disable_irq();
// __DMB();
if (!self->has_lock) {
grabbed_lock = true;
self->has_lock = true;
}
// __DMB();
// __set_PRIMASK(store_primask);
return grabbed_lock;
}
bool common_hal_busio_i2c_has_lock(busio_i2c_obj_t *self) {
return self->has_lock;
}
void common_hal_busio_i2c_unlock(busio_i2c_obj_t *self) {
self->has_lock = false;
}
uint8_t common_hal_busio_i2c_write(busio_i2c_obj_t *self, uint16_t addr,
const uint8_t *data, size_t len, bool transmit_stop_bit) {
HAL_StatusTypeDef result;
if (!transmit_stop_bit) {
uint32_t xfer_opt;
if (!self->frame_in_prog) {
xfer_opt = I2C_FIRST_FRAME;
} else {
// handle rare possibility of multiple restart writes in a row
xfer_opt = I2C_NEXT_FRAME;
}
result = HAL_I2C_Master_Seq_Transmit_IT(&(self->handle),
(uint16_t)(addr << 1), (uint8_t *)data,
(uint16_t)len, xfer_opt);
while (HAL_I2C_GetState(&(self->handle)) != HAL_I2C_STATE_READY) {
RUN_BACKGROUND_TASKS;
}
self->frame_in_prog = true;
} else {
result = HAL_I2C_Master_Transmit(&(self->handle), (uint16_t)(addr << 1),
(uint8_t *)data, (uint16_t)len, 500);
}
return result == HAL_OK ? 0 : MP_EIO;
}
uint8_t common_hal_busio_i2c_read(busio_i2c_obj_t *self, uint16_t addr,
uint8_t *data, size_t len) {
if (!self->frame_in_prog) {
return HAL_I2C_Master_Receive(&(self->handle), (uint16_t)(addr << 1), data, (uint16_t)len, 500)
== HAL_OK ? 0 : MP_EIO;
} else {
HAL_StatusTypeDef result = HAL_I2C_Master_Seq_Receive_IT(&(self->handle),
(uint16_t)(addr << 1), (uint8_t *)data,
(uint16_t)len, I2C_LAST_FRAME);
while (HAL_I2C_GetState(&(self->handle)) != HAL_I2C_STATE_READY) {
RUN_BACKGROUND_TASKS;
}
self->frame_in_prog = false;
return result;
}
}
STATIC void i2c_clock_enable(uint8_t mask) {
// Note: hard reset required due to soft reboot issue.
#ifdef I2C1
if (mask & (1 << 0)) {
__HAL_RCC_I2C1_CLK_ENABLE();
__HAL_RCC_I2C1_FORCE_RESET();
__HAL_RCC_I2C1_RELEASE_RESET();
}
#endif
#ifdef I2C2
if (mask & (1 << 1)) {
__HAL_RCC_I2C2_CLK_ENABLE();
__HAL_RCC_I2C2_FORCE_RESET();
__HAL_RCC_I2C2_RELEASE_RESET();
}
#endif
#ifdef I2C3
if (mask & (1 << 2)) {
__HAL_RCC_I2C3_CLK_ENABLE();
__HAL_RCC_I2C3_FORCE_RESET();
__HAL_RCC_I2C3_RELEASE_RESET();
}
#endif
#ifdef I2C4
if (mask & (1 << 3)) {
__HAL_RCC_I2C4_CLK_ENABLE();
__HAL_RCC_I2C4_FORCE_RESET();
__HAL_RCC_I2C4_RELEASE_RESET();
}
#endif
}
STATIC void i2c_clock_disable(uint8_t mask) {
#ifdef I2C1
if (mask & (1 << 0)) {
__HAL_RCC_I2C1_CLK_DISABLE();
}
#endif
#ifdef I2C2
if (mask & (1 << 1)) {
__HAL_RCC_I2C2_CLK_DISABLE();
}
#endif
#ifdef I2C3
if (mask & (1 << 2)) {
__HAL_RCC_I2C3_CLK_DISABLE();
}
#endif
#ifdef I2C4
if (mask & (1 << 3)) {
__HAL_RCC_I2C4_CLK_DISABLE();
}
#endif
}
STATIC void i2c_assign_irq(busio_i2c_obj_t *self, I2C_TypeDef *I2Cx) {
#ifdef I2C1
if (I2Cx == I2C1) {
self->irq = I2C1_EV_IRQn;
}
#endif
#ifdef I2C2
if (I2Cx == I2C2) {
self->irq = I2C2_EV_IRQn;
}
#endif
#ifdef I2C3
if (I2Cx == I2C3) {
self->irq = I2C3_EV_IRQn;
}
#endif
#ifdef I2C4
if (I2Cx == I2C4) {
self->irq = I2C4_EV_IRQn;
}
#endif
}
STATIC void call_hal_irq(int i2c_num) {
// Create casted context pointer
busio_i2c_obj_t *context = (busio_i2c_obj_t *)MP_STATE_PORT(cpy_i2c_obj_all)[i2c_num - 1];
if (context != NULL) {
HAL_NVIC_ClearPendingIRQ(context->irq);
HAL_I2C_EV_IRQHandler(&context->handle);
}
}
void I2C1_EV_IRQHandler(void) {
call_hal_irq(1);
}
void I2C2_EV_IRQHandler(void) {
call_hal_irq(2);
}
void I2C3_EV_IRQHandler(void) {
call_hal_irq(3);
}
void I2C4_EV_IRQHandler(void) {
call_hal_irq(4);
}
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