esp-idf/components/driver/twai.c

694 wiersze
26 KiB
C

// Copyright 2015-2018 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 "soc/soc_caps.h"
#include "sdkconfig.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/queue.h"
#include "freertos/semphr.h"
#include "esp_types.h"
#include "esp_log.h"
#include "esp_intr_alloc.h"
#include "esp_pm.h"
#include "driver/gpio.h"
#include "driver/periph_ctrl.h"
#include "driver/twai.h"
#include "soc/twai_periph.h"
#include "hal/twai_hal.h"
#include "esp_rom_gpio.h"
/* ---------------------------- Definitions --------------------------------- */
//Internal Macros
#define TWAI_CHECK(cond, ret_val) ({ \
if (!(cond)) { \
return (ret_val); \
} \
})
#define TWAI_CHECK_FROM_CRIT(cond, ret_val) ({ \
if (!(cond)) { \
TWAI_EXIT_CRITICAL(); \
return ret_val; \
} \
})
#define TWAI_SET_FLAG(var, mask) ((var) |= (mask))
#define TWAI_RESET_FLAG(var, mask) ((var) &= ~(mask))
#define TWAI_TAG "TWAI"
#define DRIVER_DEFAULT_INTERRUPTS 0xE7 //Exclude data overrun (bit[3]) and brp_div (bit[4])
//Control flags
#define CTRL_FLAG_STOPPED 0x001 //TWAI peripheral in stopped state
#define CTRL_FLAG_RECOVERING 0x002 //Bus is undergoing bus recovery
#define CTRL_FLAG_ERR_WARN 0x004 //TEC or REC is >= error warning limit
#define CTRL_FLAG_ERR_PASSIVE 0x008 //TEC or REC is >= 128
#define CTRL_FLAG_BUS_OFF 0x010 //Bus-off due to TEC >= 256
#define CTRL_FLAG_TX_BUFF_OCCUPIED 0x020 //Transmit buffer is occupied
#define ALERT_LOG_LEVEL_WARNING TWAI_ALERT_ARB_LOST //Alerts above and including this level use ESP_LOGW
#define ALERT_LOG_LEVEL_ERROR TWAI_ALERT_TX_FAILED //Alerts above and including this level use ESP_LOGE
/* ------------------ Typedefs, structures, and variables ------------------- */
//Control structure for TWAI driver
typedef struct {
//Control and status members
uint32_t control_flags;
twai_mode_t mode;
uint32_t rx_missed_count;
uint32_t tx_failed_count;
uint32_t arb_lost_count;
uint32_t bus_error_count;
intr_handle_t isr_handle;
//TX and RX
QueueHandle_t tx_queue;
QueueHandle_t rx_queue;
int tx_msg_count;
int rx_msg_count;
//Alerts
SemaphoreHandle_t alert_semphr;
uint32_t alerts_enabled;
uint32_t alerts_triggered;
#ifdef CONFIG_PM_ENABLE
//Power Management
esp_pm_lock_handle_t pm_lock;
#endif
} twai_obj_t;
static twai_obj_t *p_twai_obj = NULL;
static portMUX_TYPE twai_spinlock = portMUX_INITIALIZER_UNLOCKED;
#define TWAI_ENTER_CRITICAL_ISR() portENTER_CRITICAL_ISR(&twai_spinlock)
#define TWAI_EXIT_CRITICAL_ISR() portEXIT_CRITICAL_ISR(&twai_spinlock)
#define TWAI_ENTER_CRITICAL() portENTER_CRITICAL(&twai_spinlock)
#define TWAI_EXIT_CRITICAL() portEXIT_CRITICAL(&twai_spinlock)
static twai_hal_context_t twai_context;
/* -------------------- Interrupt and Alert Handlers ------------------------ */
static void twai_alert_handler(uint32_t alert_code, int *alert_req)
{
if (p_twai_obj->alerts_enabled & alert_code) {
//Signify alert has occurred
TWAI_SET_FLAG(p_twai_obj->alerts_triggered, alert_code);
*alert_req = 1;
if (p_twai_obj->alerts_enabled & TWAI_ALERT_AND_LOG) {
if (alert_code >= ALERT_LOG_LEVEL_ERROR) {
ESP_EARLY_LOGE(TWAI_TAG, "Alert %d", alert_code);
} else if (alert_code >= ALERT_LOG_LEVEL_WARNING) {
ESP_EARLY_LOGW(TWAI_TAG, "Alert %d", alert_code);
} else {
ESP_EARLY_LOGI(TWAI_TAG, "Alert %d", alert_code);
}
}
}
}
static inline void twai_handle_bus_off(int *alert_req)
{
//Bus-Off condition. TEC should set and held at 127, REC should be 0, reset mode entered
TWAI_SET_FLAG(p_twai_obj->control_flags, CTRL_FLAG_BUS_OFF);
/* Note: REC is still allowed to increase during bus-off. REC > err_warn
can prevent "bus recovery complete" interrupt from occurring. Set to
listen only mode to freeze REC. */
twai_hal_handle_bus_off(&twai_context);
twai_alert_handler(TWAI_ALERT_BUS_OFF, alert_req);
}
static inline void twai_handle_recovery_complete(int *alert_req)
{
//Bus recovery complete.
assert(twai_hal_handle_bus_recov_cplt(&twai_context));
//Reset and set flags to the equivalent of the stopped state
TWAI_RESET_FLAG(p_twai_obj->control_flags, CTRL_FLAG_RECOVERING | CTRL_FLAG_ERR_WARN |
CTRL_FLAG_ERR_PASSIVE | CTRL_FLAG_BUS_OFF |
CTRL_FLAG_TX_BUFF_OCCUPIED);
TWAI_SET_FLAG(p_twai_obj->control_flags, CTRL_FLAG_STOPPED);
twai_alert_handler(TWAI_ALERT_BUS_RECOVERED, alert_req);
}
static inline void twai_handle_recovery_in_progress(int * alert_req)
{
//Bus-recovery in progress. TEC has dropped below error warning limit
twai_alert_handler(TWAI_ALERT_RECOVERY_IN_PROGRESS, alert_req);
}
static inline void twai_handle_above_ewl(int *alert_req)
{
//TEC or REC surpassed error warning limit
TWAI_SET_FLAG(p_twai_obj->control_flags, CTRL_FLAG_ERR_WARN);
twai_alert_handler(TWAI_ALERT_ABOVE_ERR_WARN, alert_req);
}
static inline void twai_handle_below_ewl(int *alert_req)
{
//TEC and REC are both below error warning
TWAI_RESET_FLAG(p_twai_obj->control_flags, CTRL_FLAG_ERR_WARN);
twai_alert_handler(TWAI_ALERT_BELOW_ERR_WARN, alert_req);
}
static inline void twai_handle_error_passive(int *alert_req)
{
//Entered error passive
TWAI_SET_FLAG(p_twai_obj->control_flags, CTRL_FLAG_ERR_PASSIVE);
twai_alert_handler(TWAI_ALERT_ERR_PASS, alert_req);
}
static inline void twai_handle_error_active(int *alert_req)
{
//Returned to error active
TWAI_RESET_FLAG(p_twai_obj->control_flags, CTRL_FLAG_ERR_PASSIVE);
twai_alert_handler(TWAI_ALERT_ERR_ACTIVE, alert_req);
}
static inline void twai_handle_bus_error(int *alert_req)
{
// ECC register is read to re-arm bus error interrupt. ECC is not used
twai_hal_handle_bus_error(&twai_context);
p_twai_obj->bus_error_count++;
twai_alert_handler(TWAI_ALERT_BUS_ERROR, alert_req);
}
static inline void twai_handle_arb_lost(int *alert_req)
{
//ALC register is read to re-arm arb lost interrupt. ALC is not used
twai_hal_handle_arb_lost(&twai_context);
p_twai_obj->arb_lost_count++;
twai_alert_handler(TWAI_ALERT_ARB_LOST, alert_req);
}
static inline void twai_handle_rx_buffer_frames(BaseType_t *task_woken, int *alert_req)
{
uint32_t msg_count = twai_hal_get_rx_msg_count(&twai_context);
for (int i = 0; i < msg_count; i++) {
twai_hal_frame_t frame;
twai_hal_read_rx_buffer_and_clear(&twai_context, &frame);
//Copy frame into RX Queue
if (xQueueSendFromISR(p_twai_obj->rx_queue, &frame, task_woken) == pdTRUE) {
p_twai_obj->rx_msg_count++;
} else {
p_twai_obj->rx_missed_count++;
twai_alert_handler(TWAI_ALERT_RX_QUEUE_FULL, alert_req);
}
}
//Todo: Add Software Filters
//Todo: Check for data overrun of RX FIFO, then trigger alert
}
static inline void twai_handle_tx_buffer_frame(BaseType_t *task_woken, int *alert_req)
{
//Handle previously transmitted frame
if (twai_hal_check_last_tx_successful(&twai_context)) {
twai_alert_handler(TWAI_ALERT_TX_SUCCESS, alert_req);
} else {
p_twai_obj->tx_failed_count++;
twai_alert_handler(TWAI_ALERT_TX_FAILED, alert_req);
}
//Update TX message count
p_twai_obj->tx_msg_count--;
assert(p_twai_obj->tx_msg_count >= 0); //Sanity check
//Check if there are more frames to transmit
if (p_twai_obj->tx_msg_count > 0 && p_twai_obj->tx_queue != NULL) {
twai_hal_frame_t frame;
int res = xQueueReceiveFromISR(p_twai_obj->tx_queue, &frame, task_woken);
if (res == pdTRUE) {
twai_hal_set_tx_buffer_and_transmit(&twai_context, &frame);
} else {
assert(false && "failed to get a frame from TX queue");
}
} else {
//No more frames to transmit
TWAI_RESET_FLAG(p_twai_obj->control_flags, CTRL_FLAG_TX_BUFF_OCCUPIED);
twai_alert_handler(TWAI_ALERT_TX_IDLE, alert_req);
}
}
static void twai_intr_handler_main(void *arg)
{
BaseType_t task_woken = pdFALSE;
int alert_req = 0;
uint32_t event;
TWAI_ENTER_CRITICAL_ISR();
if (p_twai_obj == NULL) { //Incase intr occurs whilst driver is being uninstalled
TWAI_EXIT_CRITICAL_ISR();
return;
}
event = twai_hal_decode_interrupt_events(&twai_context, p_twai_obj->control_flags & CTRL_FLAG_RECOVERING);
if (event & TWAI_HAL_EVENT_BUS_OFF) {
twai_handle_bus_off(&alert_req);
}
if (event & TWAI_HAL_EVENT_BUS_RECOV_CPLT) {
twai_handle_recovery_complete(&alert_req);
}
if (event & TWAI_HAL_EVENT_BUS_RECOV_PROGRESS) {
twai_handle_recovery_in_progress(&alert_req);
}
if (event & TWAI_HAL_EVENT_ABOVE_EWL) {
twai_handle_above_ewl(&alert_req);
}
if (event & TWAI_HAL_EVENT_BELOW_EWL) {
twai_handle_below_ewl(&alert_req);
}
if (event & TWAI_HAL_EVENT_ERROR_PASSIVE) {
twai_handle_error_passive(&alert_req);
}
if (event & TWAI_HAL_EVENT_ERROR_ACTIVE) {
twai_handle_error_active(&alert_req);
}
if (event & TWAI_HAL_EVENT_BUS_ERR) {
twai_handle_bus_error(&alert_req);
}
if (event & TWAI_HAL_EVENT_ARB_LOST) {
twai_handle_arb_lost(&alert_req);
}
if (event & TWAI_HAL_EVENT_RX_BUFF_FRAME) {
twai_handle_rx_buffer_frames(&task_woken, &alert_req);
}
//TX command related handlers should be called last, so that other commands
//do not overwrite the TX command related bits in the command register.
if (event & TWAI_HAL_EVENT_TX_BUFF_FREE) {
twai_handle_tx_buffer_frame(&task_woken, &alert_req);
}
TWAI_EXIT_CRITICAL_ISR();
if (p_twai_obj->alert_semphr != NULL && alert_req) {
//Give semaphore if alerts were triggered
xSemaphoreGiveFromISR(p_twai_obj->alert_semphr, &task_woken);
}
if (task_woken == pdTRUE) {
portYIELD_FROM_ISR();
}
}
/* --------------------------- GPIO functions ------------------------------ */
static void twai_configure_gpio(gpio_num_t tx, gpio_num_t rx, gpio_num_t clkout, gpio_num_t bus_status)
{
//Set TX pin
gpio_set_pull_mode(tx, GPIO_FLOATING);
esp_rom_gpio_connect_out_signal(tx, TWAI_TX_IDX, false, false);
esp_rom_gpio_pad_select_gpio(tx);
//Set RX pin
gpio_set_pull_mode(rx, GPIO_FLOATING);
esp_rom_gpio_connect_in_signal(rx, TWAI_RX_IDX, false);
esp_rom_gpio_pad_select_gpio(rx);
gpio_set_direction(rx, GPIO_MODE_INPUT);
//Configure output clock pin (Optional)
if (clkout >= 0 && clkout < GPIO_NUM_MAX) {
gpio_set_pull_mode(clkout, GPIO_FLOATING);
esp_rom_gpio_connect_out_signal(clkout, TWAI_CLKOUT_IDX, false, false);
esp_rom_gpio_pad_select_gpio(clkout);
}
//Configure bus status pin (Optional)
if (bus_status >= 0 && bus_status < GPIO_NUM_MAX) {
gpio_set_pull_mode(bus_status, GPIO_FLOATING);
esp_rom_gpio_connect_out_signal(bus_status, TWAI_BUS_OFF_ON_IDX, false, false);
esp_rom_gpio_pad_select_gpio(bus_status);
}
}
/* ---------------------------- Public Functions ---------------------------- */
esp_err_t twai_driver_install(const twai_general_config_t *g_config, const twai_timing_config_t *t_config, const twai_filter_config_t *f_config)
{
//Check arguments
TWAI_CHECK(g_config != NULL, ESP_ERR_INVALID_ARG);
TWAI_CHECK(t_config != NULL, ESP_ERR_INVALID_ARG);
TWAI_CHECK(f_config != NULL, ESP_ERR_INVALID_ARG);
TWAI_CHECK(g_config->rx_queue_len > 0, ESP_ERR_INVALID_ARG);
TWAI_CHECK(g_config->tx_io >= 0 && g_config->tx_io < GPIO_NUM_MAX, ESP_ERR_INVALID_ARG);
TWAI_CHECK(g_config->rx_io >= 0 && g_config->rx_io < GPIO_NUM_MAX, ESP_ERR_INVALID_ARG);
TWAI_CHECK(TWAI_BRP_IS_VALID(t_config->brp), ESP_ERR_INVALID_ARG);
esp_err_t ret;
twai_obj_t *p_twai_obj_dummy;
//Create a TWAI object
p_twai_obj_dummy = calloc(1, sizeof(twai_obj_t));
TWAI_CHECK(p_twai_obj_dummy != NULL, ESP_ERR_NO_MEM);
//Initialize queues, semaphores, and power management locks
p_twai_obj_dummy->tx_queue = (g_config->tx_queue_len > 0) ? xQueueCreate(g_config->tx_queue_len, sizeof(twai_hal_frame_t)) : NULL;
p_twai_obj_dummy->rx_queue = xQueueCreate(g_config->rx_queue_len, sizeof(twai_hal_frame_t));
p_twai_obj_dummy->alert_semphr = xSemaphoreCreateBinary();
if ((g_config->tx_queue_len > 0 && p_twai_obj_dummy->tx_queue == NULL) ||
p_twai_obj_dummy->rx_queue == NULL || p_twai_obj_dummy->alert_semphr == NULL) {
ret = ESP_ERR_NO_MEM;
goto err;
}
#ifdef CONFIG_PM_ENABLE
esp_err_t pm_err = esp_pm_lock_create(ESP_PM_APB_FREQ_MAX, 0, "twai", &(p_twai_obj_dummy->pm_lock));
if (pm_err != ESP_OK ) {
ret = pm_err;
goto err;
}
#endif
//Initialize flags and variables. All other members are 0 initialized by calloc()
p_twai_obj_dummy->control_flags = CTRL_FLAG_STOPPED;
p_twai_obj_dummy->mode = g_config->mode;
p_twai_obj_dummy->alerts_enabled = g_config->alerts_enabled;
//Initialize TWAI peripheral registers, and allocate interrupt
TWAI_ENTER_CRITICAL();
if (p_twai_obj == NULL) {
p_twai_obj = p_twai_obj_dummy;
} else {
//Check if driver is already installed
TWAI_EXIT_CRITICAL();
ret = ESP_ERR_INVALID_STATE;
goto err;
}
periph_module_reset(PERIPH_TWAI_MODULE);
periph_module_enable(PERIPH_TWAI_MODULE); //Enable APB CLK to TWAI peripheral
assert(twai_hal_init(&twai_context));
twai_hal_configure(&twai_context, t_config, f_config, DRIVER_DEFAULT_INTERRUPTS, g_config->clkout_divider);
//Todo: Allow interrupt to be registered to specified CPU
TWAI_EXIT_CRITICAL();
//Allocate GPIO and Interrupts
twai_configure_gpio(g_config->tx_io, g_config->rx_io, g_config->clkout_io, g_config->bus_off_io);
ESP_ERROR_CHECK(esp_intr_alloc(ETS_TWAI_INTR_SOURCE, 0, twai_intr_handler_main, NULL, &p_twai_obj->isr_handle));
#ifdef CONFIG_PM_ENABLE
ESP_ERROR_CHECK(esp_pm_lock_acquire(p_twai_obj->pm_lock)); //Acquire pm_lock to keep APB clock at 80MHz
#endif
return ESP_OK; //TWAI module is still in reset mode, users need to call twai_start() afterwards
err:
//Cleanup TWAI object and return error
if (p_twai_obj_dummy != NULL) {
if (p_twai_obj_dummy->tx_queue != NULL) {
vQueueDelete(p_twai_obj_dummy->tx_queue);
p_twai_obj_dummy->tx_queue = NULL;
}
if (p_twai_obj_dummy->rx_queue != NULL) {
vQueueDelete(p_twai_obj_dummy->rx_queue);
p_twai_obj_dummy->rx_queue = NULL;
}
if (p_twai_obj_dummy->alert_semphr != NULL) {
vSemaphoreDelete(p_twai_obj_dummy->alert_semphr);
p_twai_obj_dummy->alert_semphr = NULL;
}
#ifdef CONFIG_PM_ENABLE
if (p_twai_obj_dummy->pm_lock != NULL) {
ESP_ERROR_CHECK(esp_pm_lock_delete(p_twai_obj_dummy->pm_lock));
}
#endif
free(p_twai_obj_dummy);
}
return ret;
}
esp_err_t twai_driver_uninstall(void)
{
twai_obj_t *p_twai_obj_dummy;
TWAI_ENTER_CRITICAL();
//Check state
TWAI_CHECK_FROM_CRIT(p_twai_obj != NULL, ESP_ERR_INVALID_STATE);
TWAI_CHECK_FROM_CRIT(p_twai_obj->control_flags & (CTRL_FLAG_STOPPED | CTRL_FLAG_BUS_OFF), ESP_ERR_INVALID_STATE);
//Todo: Add check to see if in reset mode. //Enter reset mode to stop any TWAI bus activity
//Clear registers by reading
twai_hal_deinit(&twai_context);
periph_module_disable(PERIPH_TWAI_MODULE); //Disable TWAI peripheral
p_twai_obj_dummy = p_twai_obj; //Use dummy to shorten critical section
p_twai_obj = NULL;
TWAI_EXIT_CRITICAL();
ESP_ERROR_CHECK(esp_intr_free(p_twai_obj_dummy->isr_handle)); //Free interrupt
//Delete queues, semaphores, and power management locks
if (p_twai_obj_dummy->tx_queue != NULL) {
vQueueDelete(p_twai_obj_dummy->tx_queue);
}
vQueueDelete(p_twai_obj_dummy->rx_queue);
vSemaphoreDelete(p_twai_obj_dummy->alert_semphr);
#ifdef CONFIG_PM_ENABLE
//Release and delete power management lock
ESP_ERROR_CHECK(esp_pm_lock_release(p_twai_obj_dummy->pm_lock));
ESP_ERROR_CHECK(esp_pm_lock_delete(p_twai_obj_dummy->pm_lock));
#endif
free(p_twai_obj_dummy); //Free can driver object
return ESP_OK;
}
esp_err_t twai_start(void)
{
//Check state
TWAI_ENTER_CRITICAL();
TWAI_CHECK_FROM_CRIT(p_twai_obj != NULL, ESP_ERR_INVALID_STATE);
TWAI_CHECK_FROM_CRIT(p_twai_obj->control_flags & CTRL_FLAG_STOPPED, ESP_ERR_INVALID_STATE);
//Reset RX queue, and RX message count
xQueueReset(p_twai_obj->rx_queue);
p_twai_obj->rx_msg_count = 0;
//Todo: Add assert to see if in reset mode. //Should already be in bus-off mode, set again to make sure
//Currently in listen only mode, need to set to mode specified by configuration
assert(twai_hal_start(&twai_context, p_twai_obj->mode));
TWAI_RESET_FLAG(p_twai_obj->control_flags, CTRL_FLAG_STOPPED);
TWAI_EXIT_CRITICAL();
return ESP_OK;
}
esp_err_t twai_stop(void)
{
//Check state
TWAI_ENTER_CRITICAL();
TWAI_CHECK_FROM_CRIT(p_twai_obj != NULL, ESP_ERR_INVALID_STATE);
TWAI_CHECK_FROM_CRIT(!(p_twai_obj->control_flags & (CTRL_FLAG_STOPPED | CTRL_FLAG_BUS_OFF)), ESP_ERR_INVALID_STATE);
assert(twai_hal_stop(&twai_context));
TWAI_RESET_FLAG(p_twai_obj->control_flags, CTRL_FLAG_TX_BUFF_OCCUPIED);
TWAI_SET_FLAG(p_twai_obj->control_flags, CTRL_FLAG_STOPPED);
//Reset TX Queue and message count
if (p_twai_obj->tx_queue != NULL) {
xQueueReset(p_twai_obj->tx_queue);
}
p_twai_obj->tx_msg_count = 0;
TWAI_EXIT_CRITICAL();
return ESP_OK;
}
esp_err_t twai_transmit(const twai_message_t *message, TickType_t ticks_to_wait)
{
//Check arguments
TWAI_CHECK(p_twai_obj != NULL, ESP_ERR_INVALID_STATE);
TWAI_CHECK(message != NULL, ESP_ERR_INVALID_ARG);
TWAI_CHECK((message->data_length_code <= TWAI_FRAME_MAX_DLC) || message->dlc_non_comp, ESP_ERR_INVALID_ARG);
TWAI_ENTER_CRITICAL();
//Check State
TWAI_CHECK_FROM_CRIT(!(p_twai_obj->mode == TWAI_MODE_LISTEN_ONLY), ESP_ERR_NOT_SUPPORTED);
TWAI_CHECK_FROM_CRIT(!(p_twai_obj->control_flags & (CTRL_FLAG_STOPPED | CTRL_FLAG_BUS_OFF)), ESP_ERR_INVALID_STATE);
//Format frame
esp_err_t ret = ESP_FAIL;
twai_hal_frame_t tx_frame;
twai_hal_format_frame(message, &tx_frame);
//Check if frame can be sent immediately
if ((p_twai_obj->tx_msg_count == 0) && !(p_twai_obj->control_flags & CTRL_FLAG_TX_BUFF_OCCUPIED)) {
//No other frames waiting to transmit. Bypass queue and transmit immediately
twai_hal_set_tx_buffer_and_transmit(&twai_context, &tx_frame);
p_twai_obj->tx_msg_count++;
TWAI_SET_FLAG(p_twai_obj->control_flags, CTRL_FLAG_TX_BUFF_OCCUPIED);
ret = ESP_OK;
}
TWAI_EXIT_CRITICAL();
if (ret != ESP_OK) {
if (p_twai_obj->tx_queue == NULL) {
//TX Queue is disabled and TX buffer is occupied, message was not sent
ret = ESP_FAIL;
} else if (xQueueSend(p_twai_obj->tx_queue, &tx_frame, ticks_to_wait) == pdTRUE) {
//Copied to TX Queue
TWAI_ENTER_CRITICAL();
if (p_twai_obj->control_flags & (CTRL_FLAG_STOPPED | CTRL_FLAG_BUS_OFF)) {
//TX queue was reset (due to stop/bus_off), remove copied frame from queue to prevent transmission
int res = xQueueReceive(p_twai_obj->tx_queue, &tx_frame, 0);
assert(res == pdTRUE);
ret = ESP_ERR_INVALID_STATE;
} else if ((p_twai_obj->tx_msg_count == 0) && !(p_twai_obj->control_flags & CTRL_FLAG_TX_BUFF_OCCUPIED)) {
//TX buffer was freed during copy, manually trigger transmission
int res = xQueueReceive(p_twai_obj->tx_queue, &tx_frame, 0);
assert(res == pdTRUE);
twai_hal_set_tx_buffer_and_transmit(&twai_context, &tx_frame);
p_twai_obj->tx_msg_count++;
TWAI_SET_FLAG(p_twai_obj->control_flags, CTRL_FLAG_TX_BUFF_OCCUPIED);
ret = ESP_OK;
} else {
//Frame was copied to queue, waiting to be transmitted
p_twai_obj->tx_msg_count++;
ret = ESP_OK;
}
TWAI_EXIT_CRITICAL();
} else {
//Timed out waiting for free space on TX queue
ret = ESP_ERR_TIMEOUT;
}
}
return ret;
}
esp_err_t twai_receive(twai_message_t *message, TickType_t ticks_to_wait)
{
//Check arguments and state
TWAI_CHECK(p_twai_obj != NULL, ESP_ERR_INVALID_STATE);
TWAI_CHECK(message != NULL, ESP_ERR_INVALID_ARG);
//Get frame from RX Queue or RX Buffer
twai_hal_frame_t rx_frame;
if (xQueueReceive(p_twai_obj->rx_queue, &rx_frame, ticks_to_wait) != pdTRUE) {
return ESP_ERR_TIMEOUT;
}
TWAI_ENTER_CRITICAL();
p_twai_obj->rx_msg_count--;
TWAI_EXIT_CRITICAL();
//Decode frame
twai_hal_parse_frame(&rx_frame, message);
return ESP_OK;
}
esp_err_t twai_read_alerts(uint32_t *alerts, TickType_t ticks_to_wait)
{
//Check arguments and state
TWAI_CHECK(p_twai_obj != NULL, ESP_ERR_INVALID_STATE);
TWAI_CHECK(alerts != NULL, ESP_ERR_INVALID_ARG);
//Wait for an alert to occur
if (xSemaphoreTake(p_twai_obj->alert_semphr, ticks_to_wait) == pdTRUE) {
TWAI_ENTER_CRITICAL();
*alerts = p_twai_obj->alerts_triggered;
p_twai_obj->alerts_triggered = 0; //Clear triggered alerts
TWAI_EXIT_CRITICAL();
return ESP_OK;
} else {
*alerts = 0;
return ESP_ERR_TIMEOUT;
}
}
esp_err_t twai_reconfigure_alerts(uint32_t alerts_enabled, uint32_t *current_alerts)
{
TWAI_CHECK(p_twai_obj != NULL, ESP_ERR_INVALID_STATE);
TWAI_ENTER_CRITICAL();
//Clear any unhandled alerts
if (current_alerts != NULL) {
*current_alerts = p_twai_obj->alerts_triggered;;
}
p_twai_obj->alerts_triggered = 0;
p_twai_obj->alerts_enabled = alerts_enabled; //Update enabled alerts
TWAI_EXIT_CRITICAL();
return ESP_OK;
}
esp_err_t twai_initiate_recovery(void)
{
TWAI_ENTER_CRITICAL();
//Check state
TWAI_CHECK_FROM_CRIT(p_twai_obj != NULL, ESP_ERR_INVALID_STATE);
TWAI_CHECK_FROM_CRIT(p_twai_obj->control_flags & CTRL_FLAG_BUS_OFF, ESP_ERR_INVALID_STATE);
TWAI_CHECK_FROM_CRIT(!(p_twai_obj->control_flags & CTRL_FLAG_RECOVERING), ESP_ERR_INVALID_STATE);
//Reset TX Queue/Counters
if (p_twai_obj->tx_queue != NULL) {
xQueueReset(p_twai_obj->tx_queue);
}
p_twai_obj->tx_msg_count = 0;
TWAI_RESET_FLAG(p_twai_obj->control_flags, CTRL_FLAG_TX_BUFF_OCCUPIED);
TWAI_SET_FLAG(p_twai_obj->control_flags, CTRL_FLAG_RECOVERING);
//Trigger start of recovery process
assert(twai_hal_start_bus_recovery(&twai_context));
TWAI_EXIT_CRITICAL();
return ESP_OK;
}
esp_err_t twai_get_status_info(twai_status_info_t *status_info)
{
//Check parameters and state
TWAI_CHECK(p_twai_obj != NULL, ESP_ERR_INVALID_STATE);
TWAI_CHECK(status_info != NULL, ESP_ERR_INVALID_ARG);
TWAI_ENTER_CRITICAL();
status_info->tx_error_counter = twai_hal_get_tec(&twai_context);
status_info->rx_error_counter = twai_hal_get_rec(&twai_context);
status_info->msgs_to_tx = p_twai_obj->tx_msg_count;
status_info->msgs_to_rx = p_twai_obj->rx_msg_count;
status_info->tx_failed_count = p_twai_obj->tx_failed_count;
status_info->rx_missed_count = p_twai_obj->rx_missed_count;
status_info->arb_lost_count = p_twai_obj->arb_lost_count;
status_info->bus_error_count = p_twai_obj->bus_error_count;
if (p_twai_obj->control_flags & CTRL_FLAG_RECOVERING) {
status_info->state = TWAI_STATE_RECOVERING;
} else if (p_twai_obj->control_flags & CTRL_FLAG_BUS_OFF) {
status_info->state = TWAI_STATE_BUS_OFF;
} else if (p_twai_obj->control_flags & CTRL_FLAG_STOPPED) {
status_info->state = TWAI_STATE_STOPPED;
} else {
status_info->state = TWAI_STATE_RUNNING;
}
TWAI_EXIT_CRITICAL();
return ESP_OK;
}
esp_err_t twai_clear_transmit_queue(void)
{
//Check State
TWAI_CHECK(p_twai_obj != NULL, ESP_ERR_INVALID_STATE);
TWAI_CHECK(p_twai_obj->tx_queue != NULL, ESP_ERR_NOT_SUPPORTED);
TWAI_ENTER_CRITICAL();
//If a message is currently undergoing transmission, the tx interrupt handler will decrement tx_msg_count
p_twai_obj->tx_msg_count = (p_twai_obj->control_flags & CTRL_FLAG_TX_BUFF_OCCUPIED) ? 1 : 0;
xQueueReset(p_twai_obj->tx_queue);
TWAI_EXIT_CRITICAL();
return ESP_OK;
}
esp_err_t twai_clear_receive_queue(void)
{
//Check State
TWAI_CHECK(p_twai_obj != NULL, ESP_ERR_INVALID_STATE);
TWAI_ENTER_CRITICAL();
p_twai_obj->rx_msg_count = 0;
xQueueReset(p_twai_obj->rx_queue);
TWAI_EXIT_CRITICAL();
return ESP_OK;
}