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https://github.com/espressif/esp-idf.git
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1f6d7fa334
This commit adds a workaround for the TWAI listen only mode errata which is present on the ESP32, ESP32-S2, ESP32-S3, and ESP32-C3. twai_get_status_info() has also been updated to account for the fact that TEC/REC are frozen in listen only mode. Errata Description: When the TWAI controller is put into listen only mode, it should not influence the TWAI bus in any way (i.e., should never send a dominant bit). However, on the targets listed above, the TWAI controller will send dominant bits in an error frame (i.e., active error frame), even if the controller is set to listen only mode. Workaround: We can force the TWAI controller into the error passive state on startup (by setting the REC to >= 128). Since the TEC/REC are frozen in listen only mode, the TWAI controller will remain error passive and only send recessive bits (i.e., passive error frames), thus will not influence the TWAI bus. Closes https://github.com/espressif/esp-idf/issues/9157
101 lines
4.2 KiB
C
101 lines
4.2 KiB
C
// Copyright 2015-2019 Espressif Systems (Shanghai) PTE LTD
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include <stddef.h>
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#include "sdkconfig.h"
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#include "hal/twai_hal.h"
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#include "soc/soc_caps.h"
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//Default values written to various registers on initialization
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#define TWAI_HAL_INIT_TEC 0
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#define TWAI_HAL_INIT_REC 0
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#define TWAI_HAL_INIT_EWL 96
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/* ---------------------------- Init and Config ----------------------------- */
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bool twai_hal_init(twai_hal_context_t *hal_ctx)
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{
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//Initialize HAL context
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hal_ctx->dev = &TWAI;
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hal_ctx->state_flags = 0;
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//Initialize TWAI controller, and set default values to registers
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twai_ll_enter_reset_mode(hal_ctx->dev);
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if (!twai_ll_is_in_reset_mode(hal_ctx->dev)) { //Must enter reset mode to write to config registers
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return false;
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}
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#if SOC_TWAI_SUPPORT_MULTI_ADDRESS_LAYOUT
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twai_ll_enable_extended_reg_layout(hal_ctx->dev); //Changes the address layout of the registers
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#endif
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twai_ll_set_mode(hal_ctx->dev, TWAI_MODE_LISTEN_ONLY); //Freeze REC by changing to LOM mode
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//Both TEC and REC should start at 0
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twai_ll_set_tec(hal_ctx->dev, TWAI_HAL_INIT_TEC);
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twai_ll_set_rec(hal_ctx->dev, TWAI_HAL_INIT_REC);
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twai_ll_set_err_warn_lim(hal_ctx->dev, TWAI_HAL_INIT_EWL); //Set default value of for EWL
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return true;
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}
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void twai_hal_deinit(twai_hal_context_t *hal_ctx)
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{
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//Clear any pending registers
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(void) twai_ll_get_and_clear_intrs(hal_ctx->dev);
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twai_ll_set_enabled_intrs(hal_ctx->dev, 0);
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twai_ll_clear_arb_lost_cap(hal_ctx->dev);
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twai_ll_clear_err_code_cap(hal_ctx->dev);
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hal_ctx->dev = NULL;
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}
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void twai_hal_configure(twai_hal_context_t *hal_ctx, const twai_timing_config_t *t_config, const twai_filter_config_t *f_config, uint32_t intr_mask, uint32_t clkout_divider)
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{
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//Configure bus timing, acceptance filter, CLKOUT, and interrupts
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twai_ll_set_bus_timing(hal_ctx->dev, t_config->brp, t_config->sjw, t_config->tseg_1, t_config->tseg_2, t_config->triple_sampling);
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twai_ll_set_acc_filter(hal_ctx->dev, f_config->acceptance_code, f_config->acceptance_mask, f_config->single_filter);
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twai_ll_set_clkout(hal_ctx->dev, clkout_divider);
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twai_ll_set_enabled_intrs(hal_ctx->dev, intr_mask);
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(void) twai_ll_get_and_clear_intrs(hal_ctx->dev); //Clear any latched interrupts
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}
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/* -------------------------------- Actions --------------------------------- */
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void twai_hal_start(twai_hal_context_t *hal_ctx, twai_mode_t mode)
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{
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twai_ll_set_mode(hal_ctx->dev, mode); //Set operating mode
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//Clear the TEC and REC
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twai_ll_set_tec(hal_ctx->dev, 0);
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#ifdef CONFIG_TWAI_ERRATA_FIX_LISTEN_ONLY_DOM
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/*
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Errata workaround: Prevent transmission of dominant error frame while in listen only mode by setting REC to 128
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before exiting reset mode. This forces the controller to be error passive (thus only transmits recessive bits).
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The TEC/REC remain frozen in listen only mode thus ensuring we remain error passive.
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*/
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if (mode == TWAI_MODE_LISTEN_ONLY) {
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twai_ll_set_rec(hal_ctx->dev, 128);
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} else
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#endif
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{
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twai_ll_set_rec(hal_ctx->dev, 0);
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}
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(void) twai_ll_get_and_clear_intrs(hal_ctx->dev); //Clear any latched interrupts
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TWAI_HAL_SET_BITS(hal_ctx->state_flags, TWAI_HAL_STATE_FLAG_RUNNING);
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twai_ll_exit_reset_mode(hal_ctx->dev);
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}
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void twai_hal_stop(twai_hal_context_t *hal_ctx)
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{
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twai_ll_enter_reset_mode(hal_ctx->dev);
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(void) twai_ll_get_and_clear_intrs(hal_ctx->dev);
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twai_ll_set_mode(hal_ctx->dev, TWAI_MODE_LISTEN_ONLY); //Freeze REC by changing to LOM mode
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//Any TX is immediately halted on entering reset mode
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TWAI_HAL_CLEAR_BITS(hal_ctx->state_flags, TWAI_HAL_STATE_FLAG_TX_BUFF_OCCUPIED | TWAI_HAL_STATE_FLAG_RUNNING);
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}
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