esp-idf/components/hal/twai_hal_iram.c
Darian Leung 2f58060921 TWAI: FIFO overrun handling and errata workarounds
This commit adds handling for FIFO overruns and
adds workarounds for HW errats on the ESP32.

Closes https://github.com/espressif/esp-idf/issues/2519
Closes https://github.com/espressif/esp-idf/issues/4276
2021-03-30 14:17:31 +08:00

205 lines
9.5 KiB
C

// Copyright 2015-2019 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <stddef.h>
#include <string.h>
#include "sdkconfig.h"
#include "hal/twai_hal.h"
#ifdef CONFIG_TWAI_ERRATA_FIX_RX_FIFO_CORRUPT
//Errata condition occurs at 64 messages. Threshold set to 62 to prevent the chance of failing to detect errata condition.
#define TWAI_RX_FIFO_CORRUPT_THRESH 62
#endif
/* ----------------------------- Event Handling ----------------------------- */
/**
* Helper functions that can decode what events have been triggered based on
* the values of the interrupt, status, TEC and REC registers. The HAL context's
* state flags are also updated based on the events that have triggered.
*/
static inline uint32_t twai_hal_decode_interrupt(twai_hal_context_t *hal_ctx)
{
uint32_t events = 0;
uint32_t interrupts = twai_ll_get_and_clear_intrs(hal_ctx->dev);
uint32_t status = twai_ll_get_status(hal_ctx->dev);
uint32_t tec = twai_ll_get_tec(hal_ctx->dev);
uint32_t rec = twai_ll_get_rec(hal_ctx->dev);
uint32_t state_flags = hal_ctx->state_flags;
//Error Warning Interrupt set whenever Error or Bus Status bit changes
if (interrupts & TWAI_LL_INTR_EI) {
if (status & TWAI_LL_STATUS_BS) { //Currently in BUS OFF state
if (status & TWAI_LL_STATUS_ES) { //EWL is exceeded, thus must have entered BUS OFF
TWAI_HAL_SET_BITS(events, TWAI_HAL_EVENT_BUS_OFF);
TWAI_HAL_SET_BITS(state_flags, TWAI_HAL_STATE_FLAG_BUS_OFF);
//Any TX would have been halted by entering bus off. Reset its flag
TWAI_HAL_CLEAR_BITS(state_flags, TWAI_HAL_STATE_FLAG_RUNNING | TWAI_HAL_STATE_FLAG_TX_BUFF_OCCUPIED);
} else {
//Below EWL. Therefore TEC is counting down in bus recovery
TWAI_HAL_SET_BITS(events, TWAI_HAL_EVENT_BUS_RECOV_PROGRESS);
}
} else { //Not in BUS OFF
if (status & TWAI_LL_STATUS_ES) { //Just Exceeded EWL
TWAI_HAL_SET_BITS(events, TWAI_HAL_EVENT_ABOVE_EWL);
TWAI_HAL_SET_BITS(state_flags, TWAI_HAL_STATE_FLAG_ERR_WARN);
} else if (hal_ctx->state_flags & TWAI_HAL_STATE_FLAG_RECOVERING) {
//Previously undergoing bus recovery. Thus means bus recovery complete
TWAI_HAL_SET_BITS(events, TWAI_HAL_EVENT_BUS_RECOV_CPLT);
TWAI_HAL_CLEAR_BITS(state_flags, TWAI_HAL_STATE_FLAG_RECOVERING | TWAI_HAL_STATE_FLAG_BUS_OFF);
} else { //Just went below EWL
TWAI_HAL_SET_BITS(events, TWAI_HAL_EVENT_BELOW_EWL);
TWAI_HAL_CLEAR_BITS(state_flags, TWAI_HAL_STATE_FLAG_ERR_WARN);
}
}
}
//Receive Interrupt set whenever RX FIFO is not empty
if (interrupts & TWAI_LL_INTR_RI) {
TWAI_HAL_SET_BITS(events, TWAI_HAL_EVENT_RX_BUFF_FRAME);
}
//Transmit interrupt set whenever TX buffer becomes free
#ifdef CONFIG_TWAI_ERRATA_FIX_TX_INTR_LOST
if ((interrupts & TWAI_LL_INTR_TI || hal_ctx->state_flags & TWAI_HAL_STATE_FLAG_TX_BUFF_OCCUPIED) && status & TWAI_LL_STATUS_TBS) {
#else
if (interrupts & TWAI_LL_INTR_TI) {
#endif
TWAI_HAL_SET_BITS(events, TWAI_HAL_EVENT_TX_BUFF_FREE);
TWAI_HAL_CLEAR_BITS(state_flags, TWAI_HAL_STATE_FLAG_TX_BUFF_OCCUPIED);
}
//Error Passive Interrupt on transition from error active to passive or vice versa
if (interrupts & TWAI_LL_INTR_EPI) {
if (tec >= TWAI_ERR_PASS_THRESH || rec >= TWAI_ERR_PASS_THRESH) {
TWAI_HAL_SET_BITS(events, TWAI_HAL_EVENT_ERROR_PASSIVE);
TWAI_HAL_SET_BITS(state_flags, TWAI_HAL_STATE_FLAG_ERR_PASSIVE);
} else {
TWAI_HAL_SET_BITS(events, TWAI_HAL_EVENT_ERROR_ACTIVE);
TWAI_HAL_CLEAR_BITS(state_flags, TWAI_HAL_STATE_FLAG_ERR_PASSIVE);
}
}
//Bus error interrupt triggered on a bus error (e.g. bit, ACK, stuff etc)
if (interrupts & TWAI_LL_INTR_BEI) {
TWAI_HAL_SET_BITS(events, TWAI_HAL_EVENT_BUS_ERR);
}
//Arbitration Lost Interrupt triggered on losing arbitration
if (interrupts & TWAI_LL_INTR_ALI) {
TWAI_HAL_SET_BITS(events, TWAI_HAL_EVENT_ARB_LOST);
}
hal_ctx->state_flags = state_flags;
return events;
}
uint32_t twai_hal_get_events(twai_hal_context_t *hal_ctx)
{
uint32_t events = twai_hal_decode_interrupt(hal_ctx);
//Handle low latency events
if (events & TWAI_HAL_EVENT_BUS_OFF) {
twai_ll_set_mode(hal_ctx->dev, TWAI_MODE_LISTEN_ONLY); //Freeze TEC/REC by entering LOM
#ifdef CONFIG_TWAI_ERRATA_FIX_BUS_OFF_REC
//Errata workaround: Force REC to 0 by re-triggering bus-off (by setting TEC to 0 then 255)
twai_ll_set_tec(hal_ctx->dev, 0);
twai_ll_set_tec(hal_ctx->dev, 255);
(void) twai_ll_get_and_clear_intrs(hal_ctx->dev); //Clear the re-triggered bus-off interrupt
#endif
}
if (events & TWAI_HAL_EVENT_BUS_RECOV_CPLT) {
twai_ll_enter_reset_mode(hal_ctx->dev); //Enter reset mode to stop the controller
}
if (events & TWAI_HAL_EVENT_BUS_ERR) {
#ifdef CONFIG_TWAI_ERRATA_FIX_RX_FRAME_INVALID
twai_ll_err_type_t type;
twai_ll_err_dir_t dir;
twai_ll_err_seg_t seg;
twai_ll_parse_err_code_cap(hal_ctx->dev, &type, &dir, &seg); //Decode error interrupt
//Check for errata condition (RX message has bus error at particular segments)
if (dir == TWAI_LL_ERR_DIR_RX &&
((seg == TWAI_LL_ERR_SEG_DATA || seg == TWAI_LL_ERR_SEG_CRC_SEQ) ||
(seg == TWAI_LL_ERR_SEG_ACK_DELIM && type == TWAI_LL_ERR_OTHER))) {
TWAI_HAL_SET_BITS(events, TWAI_HAL_EVENT_NEED_PERIPH_RESET);
}
#endif
twai_ll_clear_err_code_cap(hal_ctx->dev);
}
if (events & TWAI_HAL_EVENT_ARB_LOST) {
twai_ll_clear_arb_lost_cap(hal_ctx->dev);
}
#ifdef CONFIG_TWAI_ERRATA_FIX_RX_FIFO_CORRUPT
//Check for errata condition (rx_msg_count >= corruption_threshold)
if (events & TWAI_HAL_EVENT_RX_BUFF_FRAME && twai_ll_get_rx_msg_count(hal_ctx->dev) >= TWAI_RX_FIFO_CORRUPT_THRESH) {
TWAI_HAL_SET_BITS(events, TWAI_HAL_EVENT_NEED_PERIPH_RESET);
}
#endif
#if defined(CONFIG_TWAI_ERRATA_FIX_RX_FRAME_INVALID) || defined(CONFIG_TWAI_ERRATA_FIX_RX_FIFO_CORRUPT)
if (events & TWAI_HAL_EVENT_NEED_PERIPH_RESET) {
//A peripheral reset will invalidate an RX event;
TWAI_HAL_CLEAR_BITS(events, (TWAI_HAL_EVENT_RX_BUFF_FRAME));
}
#endif
return events;
}
#if defined(CONFIG_TWAI_ERRATA_FIX_RX_FRAME_INVALID) || defined(CONFIG_TWAI_ERRATA_FIX_RX_FIFO_CORRUPT)
void twai_hal_prepare_for_reset(twai_hal_context_t *hal_ctx)
{
uint32_t status = twai_ll_get_status(hal_ctx->dev);
if (!(status & TWAI_LL_STATUS_TBS)) { //Transmit buffer is NOT free, indicating an Ongoing TX will be cancelled by the HW reset
TWAI_HAL_SET_BITS(hal_ctx->state_flags, TWAI_HAL_STATE_FLAG_TX_NEED_RETRY);
//Note: Even if the TX completes right after this, we still consider it will be retried.
//Worst case the same message will get sent twice.
}
//Some register must saved before entering reset mode
hal_ctx->rx_msg_cnt_save = (uint8_t) twai_ll_get_rx_msg_count(hal_ctx->dev);
twai_ll_enter_reset_mode(hal_ctx->dev); //Enter reset mode to stop the controller
twai_ll_save_reg(hal_ctx->dev, &hal_ctx->reg_save); //Save remaining registers after entering reset mode
}
void twai_hal_recover_from_reset(twai_hal_context_t *hal_ctx)
{
twai_ll_enter_reset_mode(hal_ctx->dev);
twai_ll_enable_extended_reg_layout(hal_ctx->dev);
twai_ll_restore_reg(hal_ctx->dev, &hal_ctx->reg_save);
twai_ll_exit_reset_mode(hal_ctx->dev);
(void) twai_ll_get_and_clear_intrs(hal_ctx->dev);
if (hal_ctx->state_flags & TWAI_HAL_STATE_FLAG_TX_NEED_RETRY) {
//HW reset has cancelled a TX. Re-transmit here
twai_hal_set_tx_buffer_and_transmit(hal_ctx, &hal_ctx->tx_frame_save);
TWAI_HAL_CLEAR_BITS(hal_ctx->state_flags, TWAI_HAL_STATE_FLAG_TX_NEED_RETRY);
}
}
#endif //defined(CONFIG_TWAI_ERRATA_FIX_RX_FRAME_INVALID) || defined(CONFIG_TWAI_ERRATA_FIX_RX_FIFO_CORRUPT)
void twai_hal_set_tx_buffer_and_transmit(twai_hal_context_t *hal_ctx, twai_hal_frame_t *tx_frame)
{
//Copy frame into tx buffer
twai_ll_set_tx_buffer(hal_ctx->dev, tx_frame);
//Hit the send command
if (tx_frame->self_reception) {
if (tx_frame->single_shot) {
twai_ll_set_cmd_self_rx_single_shot(hal_ctx->dev);
} else {
twai_ll_set_cmd_self_rx_request(hal_ctx->dev);
}
} else if (tx_frame->single_shot){
twai_ll_set_cmd_tx_single_shot(hal_ctx->dev);
} else {
twai_ll_set_cmd_tx(hal_ctx->dev);
}
TWAI_HAL_SET_BITS(hal_ctx->state_flags, TWAI_HAL_STATE_FLAG_TX_BUFF_OCCUPIED);
#if defined(CONFIG_TWAI_ERRATA_FIX_RX_FRAME_INVALID) || defined(CONFIG_TWAI_ERRATA_FIX_RX_FIFO_CORRUPT)
//Save transmitted frame in case we need to retry
memcpy(&hal_ctx->tx_frame_save, tx_frame, sizeof(twai_hal_frame_t));
#endif //defined(CONFIG_TWAI_ERRATA_FIX_RX_FRAME_INVALID) || defined(CONFIG_TWAI_ERRATA_FIX_RX_FIFO_CORRUPT)
}