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Merge branch 'bugfix/can_backport_accumulated_fixes_v3.3' into 'release/v3.3'

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CAN backport accumulated fixes (backport v3.3)

See merge request espressif/esp-idf!11463
This commit is contained in:
Michael (XIAO Xufeng)
2020-12-04 23:57:09 +08:00
parent d96e1442b3 fcabc257a5
commit 24b910916a
5 changed files with 201 additions and 93 deletions
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23
components/driver/Kconfig
View File

@ -71,4 +71,27 @@ menu "Driver configurations"
endmenu # SPI Configuration
menu "CAN Configuration"
config CAN_ISR_IN_IRAM
bool "Place CAN ISR function into IRAM"
default n
select SUPPORT_STATIC_ALLOCATION
# We need to enable FREERTOS_SUPPORT_STATIC_ALLOCATION because the
# CAN driver requires the use of FreeRTOS Queues and Semaphores from
# the driver ISR. These Queues and Semaphores need to be placed in
# DRAM thus FreeRTOS static allocation API is required.
help
Place the CAN ISR in to IRAM. This will allow the ISR to avoid
cache misses, and also be able to run whilst the cache is disabled
(such as when writing to SPI Flash).
Note that if this option is enabled:
- Users should also set the ESP_INTR_FLAG_IRAM in the driver
configuration structure when installing the driver (see docs for
specifics).
- Alert logging (i.e., setting of the CAN_ALERT_AND_LOG flag)
will have no effect.
endmenu # CAN Configuration
endmenu # Driver configurations

237
components/driver/can.c
View File

@ -21,6 +21,8 @@
#include "esp_log.h"
#include "esp_intr_alloc.h"
#include "esp_pm.h"
#include "esp_attr.h"
#include "esp_heap_caps.h"
#include "soc/dport_reg.h"
#include "soc/can_struct.h"
#include "driver/gpio.h"
@ -42,7 +44,16 @@
})
#define CAN_SET_FLAG(var, mask) ((var) |= (mask))
#define CAN_RESET_FLAG(var, mask) ((var) &= ~(mask))
#ifdef CONFIG_CAN_ISR_IN_IRAM
#define CAN_INLINE_ATTR __attribute__((always_inline))
#define CAN_ISR_ATTR IRAM_ATTR
#define CAN_MALLOC_CAPS (MALLOC_CAP_INTERNAL | MALLOC_CAP_8BIT)
#else
#define CAN_INLINE_ATTR
#define CAN_TAG "CAN"
#define CAN_ISR_ATTR
#define CAN_MALLOC_CAPS MALLOC_CAP_DEFAULT
#endif
/*
* Baud Rate Prescaler Divider config/values. The BRP_DIV bit is located in the
@ -135,6 +146,13 @@ typedef struct {
uint32_t bus_error_count;
intr_handle_t isr_handle;
//TX and RX
#ifdef CONFIG_CAN_ISR_IN_IRAM
void *tx_queue_buff;
void *tx_queue_struct;
void *rx_queue_buff;
void *rx_queue_struct;
void *semphr_struct;
#endif
QueueHandle_t tx_queue;
QueueHandle_t rx_queue;
int tx_msg_count;
@ -158,7 +176,7 @@ static portMUX_TYPE can_spinlock = portMUX_INITIALIZER_UNLOCKED;
/* ------------------- Configuration Register Functions---------------------- */
static inline esp_err_t can_enter_reset_mode()
static inline CAN_INLINE_ATTR esp_err_t can_enter_reset_mode()
{
/* Enter reset mode (required to write to configuration registers). Reset mode
also prevents all CAN activity on the current module and is automatically
@ -183,7 +201,7 @@ static inline void can_config_pelican()
CAN.clock_divider_reg.can_mode = 1;
}
static inline void can_config_mode(can_mode_t mode)
static CAN_ISR_ATTR void can_config_mode(can_mode_t mode)
{
//Configure CAN mode of operation
can_mode_reg_t mode_reg;
@ -281,12 +299,12 @@ static inline void can_config_clk_out(uint32_t divider)
/* ---------------------- Runtime Register Functions------------------------- */
static inline void can_set_command(uint8_t commands)
static inline CAN_INLINE_ATTR void can_set_command(uint8_t commands)
{
CAN.command_reg.val = commands;
}
static void can_set_tx_buffer_and_transmit(can_frame_t *frame)
static CAN_ISR_ATTR void can_set_tx_buffer_and_transmit(can_frame_t *frame)
{
//Copy frame structure into TX buffer registers
for (int i = 0; i < FRAME_MAX_LEN; i++) {
@ -303,29 +321,29 @@ static void can_set_tx_buffer_and_transmit(can_frame_t *frame)
can_set_command(command);
}
static inline uint32_t can_get_status()
static inline CAN_INLINE_ATTR uint32_t can_get_status()
{
return CAN.status_reg.val;
}
static inline uint32_t can_get_interrupt_reason()
static inline CAN_INLINE_ATTR uint32_t can_get_interrupt_reason()
{
return CAN.interrupt_reg.val;
}
static inline uint32_t can_get_arbitration_lost_capture()
static inline CAN_INLINE_ATTR uint32_t can_get_arbitration_lost_capture()
{
return CAN.arbitration_lost_captue_reg.val;
//Todo: ALC read only to re-arm arb lost interrupt. Add function to decode ALC
}
static inline uint32_t can_get_error_code_capture()
static inline CAN_INLINE_ATTR uint32_t can_get_error_code_capture()
{
return CAN.error_code_capture_reg.val;
//Todo: ECC read only to re-arm bus error interrupt. Add function to decode ECC
}
static inline void can_get_error_counters(uint32_t *tx_error_cnt, uint32_t *rx_error_cnt)
static inline CAN_INLINE_ATTR void can_get_error_counters(uint32_t *tx_error_cnt, uint32_t *rx_error_cnt)
{
if (tx_error_cnt != NULL) {
*tx_error_cnt = CAN.tx_error_counter_reg.byte;
@ -335,7 +353,7 @@ static inline void can_get_error_counters(uint32_t *tx_error_cnt, uint32_t *rx_e
}
}
static inline void can_get_rx_buffer_and_clear(can_frame_t *frame)
static CAN_ISR_ATTR void can_get_rx_buffer_and_clear(can_frame_t *frame)
{
//Copy RX buffer registers into frame structure
for (int i = 0; i < FRAME_MAX_LEN; i++) {
@ -345,19 +363,20 @@ static inline void can_get_rx_buffer_and_clear(can_frame_t *frame)
can_set_command(CMD_RELEASE_RX_BUFF);
}
static inline uint32_t can_get_rx_message_counter()
static inline CAN_INLINE_ATTR uint32_t can_get_rx_message_counter()
{
return CAN.rx_message_counter_reg.val;
}
/* -------------------- Interrupt and Alert Handlers ------------------------ */
static void can_alert_handler(uint32_t alert_code, int *alert_req)
static CAN_ISR_ATTR void can_alert_handler(uint32_t alert_code, int *alert_req)
{
if (p_can_obj->alerts_enabled & alert_code) {
//Signify alert has occurred
CAN_SET_FLAG(p_can_obj->alerts_triggered, alert_code);
*alert_req = 1;
#ifndef CONFIG_CAN_ISR_IN_IRAM //Only log if ISR is not in IRAM
if (p_can_obj->alerts_enabled & CAN_ALERT_AND_LOG) {
if (alert_code >= ALERT_LOG_LEVEL_ERROR) {
ESP_EARLY_LOGE(CAN_TAG, "Alert %d", alert_code);
@ -367,10 +386,11 @@ static void can_alert_handler(uint32_t alert_code, int *alert_req)
ESP_EARLY_LOGI(CAN_TAG, "Alert %d", alert_code);
}
}
#endif
}
}
static void can_intr_handler_err_warn(can_status_reg_t *status, BaseType_t *task_woken, int *alert_req)
static CAN_ISR_ATTR void can_intr_handler_err_warn(can_status_reg_t *status, BaseType_t *task_woken, int *alert_req)
{
if (status->bus) {
if (status->error) {
@ -408,7 +428,7 @@ static void can_intr_handler_err_warn(can_status_reg_t *status, BaseType_t *task
}
}
static void can_intr_handler_err_passive(int *alert_req)
static inline CAN_INLINE_ATTR void can_intr_handler_err_passive(int *alert_req)
{
uint32_t tec, rec;
can_get_error_counters(&tec, &rec);
@ -423,7 +443,7 @@ static void can_intr_handler_err_passive(int *alert_req)
}
}
static void can_intr_handler_bus_err(int *alert_req)
static inline CAN_INLINE_ATTR void can_intr_handler_bus_err(int *alert_req)
{
// ECC register is read to re-arm bus error interrupt. ECC is not used
(void) can_get_error_code_capture();
@ -431,7 +451,7 @@ static void can_intr_handler_bus_err(int *alert_req)
can_alert_handler(CAN_ALERT_BUS_ERROR, alert_req);
}
static void can_intr_handler_arb_lost(int *alert_req)
static inline CAN_INLINE_ATTR void can_intr_handler_arb_lost(int *alert_req)
{
//ALC register is read to re-arm arb lost interrupt. ALC is not used
(void) can_get_arbitration_lost_capture();
@ -439,7 +459,7 @@ static void can_intr_handler_arb_lost(int *alert_req)
can_alert_handler(CAN_ALERT_ARB_LOST, alert_req);
}
static void can_intr_handler_rx(BaseType_t *task_woken, int *alert_req)
static inline CAN_INLINE_ATTR CAN_ISR_ATTR void can_intr_handler_rx(BaseType_t *task_woken, int *alert_req)
{
can_rx_msg_cnt_reg_t msg_count_reg;
msg_count_reg.val = can_get_rx_message_counter();
@ -459,7 +479,7 @@ static void can_intr_handler_rx(BaseType_t *task_woken, int *alert_req)
//Todo: Check for data overrun of RX FIFO, then trigger alert
}
static void can_intr_handler_tx(can_status_reg_t *status, int *alert_req)
static CAN_ISR_ATTR void can_intr_handler_tx(can_status_reg_t *status, int *alert_req)
{
//Handle previously transmitted frame
if (status->tx_complete) {
@ -489,7 +509,7 @@ static void can_intr_handler_tx(can_status_reg_t *status, int *alert_req)
}
}
static void can_intr_handler_main(void *arg)
static CAN_ISR_ATTR void can_intr_handler_main(void *arg)
{
BaseType_t task_woken = pdFALSE;
int alert_req = 0;
@ -542,7 +562,7 @@ static void can_intr_handler_main(void *arg)
}
}
/* ---------------------- Frame and GPIO functions ------------------------- */
/* -------------------------- Helper functions ----------------------------- */
static void can_format_frame(uint32_t id, uint8_t dlc, const uint8_t *data, uint32_t flags, can_frame_t *tx_frame)
{
@ -635,6 +655,93 @@ static void can_configure_gpio(gpio_num_t tx, gpio_num_t rx, gpio_num_t clkout,
}
}
static void can_free_driver_obj(can_obj_t *p_obj)
{
//Free driver object and any dependent SW resources it uses (queues, semaphores etc)
#ifdef CONFIG_PM_ENABLE
if (p_obj->pm_lock != NULL) {
ESP_ERROR_CHECK(esp_pm_lock_delete(p_obj->pm_lock));
}
#endif
//Delete queues and semaphores
if (p_obj->tx_queue != NULL) {
vQueueDelete(p_obj->tx_queue);
}
if (p_obj->rx_queue != NULL) {
vQueueDelete(p_obj->rx_queue);
}
if (p_obj->alert_semphr != NULL) {
vSemaphoreDelete(p_obj->alert_semphr);
}
#ifdef CONFIG_CAN_ISR_IN_IRAM
//Free memory used by static queues and semaphores. free() allows freeing NULL pointers
free(p_obj->tx_queue_buff);
free(p_obj->tx_queue_struct);
free(p_obj->rx_queue_buff);
free(p_obj->rx_queue_struct);
free(p_obj->semphr_struct);
#endif //CONFIG_CAN_ISR_IN_IRAM
free(p_obj);
}
static can_obj_t *can_alloc_driver_obj(uint32_t tx_queue_len, uint32_t rx_queue_len)
{
can_obj_t *p_obj = heap_caps_calloc(1, sizeof(can_obj_t), CAN_MALLOC_CAPS);
if (p_obj == NULL) {
return NULL;
}
#ifdef CONFIG_CAN_ISR_IN_IRAM
//Allocate memory for queues and semaphores in DRAM
if (tx_queue_len > 0) {
p_obj->tx_queue_buff = heap_caps_calloc(tx_queue_len, sizeof(can_frame_t), CAN_MALLOC_CAPS);
p_obj->tx_queue_struct = heap_caps_calloc(1, sizeof(StaticQueue_t), CAN_MALLOC_CAPS);
if (p_obj->tx_queue_buff == NULL || p_obj->tx_queue_struct == NULL) {
goto cleanup;
}
}
p_obj->rx_queue_buff = heap_caps_calloc(rx_queue_len, sizeof(can_frame_t), CAN_MALLOC_CAPS);
p_obj->rx_queue_struct = heap_caps_calloc(1, sizeof(StaticQueue_t), CAN_MALLOC_CAPS);
p_obj->semphr_struct = heap_caps_calloc(1, sizeof(StaticSemaphore_t), CAN_MALLOC_CAPS);
if (p_obj->rx_queue_buff == NULL || p_obj->rx_queue_struct == NULL || p_obj->semphr_struct == NULL) {
goto cleanup;
}
//Create static queues and semaphores
if (tx_queue_len > 0) {
p_obj->tx_queue = xQueueCreateStatic(tx_queue_len, sizeof(can_frame_t), p_obj->tx_queue_buff, p_obj->tx_queue_struct);
if (p_obj->tx_queue == NULL) {
goto cleanup;
}
}
p_obj->rx_queue = xQueueCreateStatic(rx_queue_len, sizeof(can_frame_t), p_obj->rx_queue_buff, p_obj->rx_queue_struct);
p_obj->alert_semphr = xSemaphoreCreateBinaryStatic(p_obj->semphr_struct);
if (p_obj->rx_queue == NULL || p_obj->alert_semphr == NULL) {
goto cleanup;
}
#else //CONFIG_CAN_ISR_IN_IRAM
if (tx_queue_len > 0) {
p_obj->tx_queue = xQueueCreate(tx_queue_len, sizeof(can_frame_t));
}
p_obj->rx_queue = xQueueCreate(rx_queue_len, sizeof(can_frame_t));
p_obj->alert_semphr = xSemaphoreCreateBinary();
if ((tx_queue_len > 0 && p_obj->tx_queue == NULL) || p_obj->rx_queue == NULL || p_obj->alert_semphr == NULL) {
goto cleanup;
}
#endif //CONFIG_CAN_ISR_IN_IRAM
#ifdef CONFIG_PM_ENABLE
esp_err_t pm_err = esp_pm_lock_create(ESP_PM_APB_FREQ_MAX, 0, "can", &(p_obj->pm_lock));
if (pm_err != ESP_OK ) {
goto cleanup;
}
#endif
return p_obj;
cleanup:
can_free_driver_obj(p_obj);
return NULL;
}
/* ---------------------------- Public Functions ---------------------------- */
esp_err_t can_driver_install(const can_general_config_t *g_config, const can_timing_config_t *t_config, const can_filter_config_t *f_config)
@ -652,43 +759,26 @@ esp_err_t can_driver_install(const can_general_config_t *g_config, const can_tim
#else
CAN_CHECK(BRP_CHECK_NO_DIV(t_config->brp), ESP_ERR_INVALID_ARG);
#endif
#ifndef CONFIG_CAN_ISR_IN_IRAM
CAN_CHECK(!(g_config->intr_flags & ESP_INTR_FLAG_IRAM), ESP_ERR_INVALID_ARG);
#endif
CAN_ENTER_CRITICAL();
CAN_CHECK_FROM_CRIT(p_can_obj == NULL, ESP_ERR_INVALID_STATE);
CAN_EXIT_CRITICAL();
esp_err_t ret;
can_obj_t *p_can_obj_dummy;
//Create a CAN object
p_can_obj_dummy = calloc(1, sizeof(can_obj_t));
//Create a CAN object (including queues and semaphores)
p_can_obj_dummy = can_alloc_driver_obj(g_config->tx_queue_len, g_config->rx_queue_len);
CAN_CHECK(p_can_obj_dummy != NULL, ESP_ERR_NO_MEM);
//Initialize queues, semaphores, and power management locks
p_can_obj_dummy->tx_queue = (g_config->tx_queue_len > 0) ? xQueueCreate(g_config->tx_queue_len, sizeof(can_frame_t)) : NULL;
p_can_obj_dummy->rx_queue = xQueueCreate(g_config->rx_queue_len, sizeof(can_frame_t));
p_can_obj_dummy->alert_semphr = xSemaphoreCreateBinary();
if ((g_config->tx_queue_len > 0 && p_can_obj_dummy->tx_queue == NULL) ||
p_can_obj_dummy->rx_queue == NULL || p_can_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, "can", &(p_can_obj_dummy->pm_lock));
if (pm_err != ESP_OK ) {
ret = pm_err;
goto err;
}
#endif
//Initialize flags and variables
//Initialize flags and variables. All other members are already set to zero by can_alloc_driver_obj()
p_can_obj_dummy->control_flags = CTRL_FLAG_STOPPED;
p_can_obj_dummy->control_flags |= (g_config->mode == CAN_MODE_NO_ACK) ? CTRL_FLAG_SELF_TEST : 0;
p_can_obj_dummy->control_flags |= (g_config->mode == CAN_MODE_LISTEN_ONLY) ? CTRL_FLAG_LISTEN_ONLY : 0;
p_can_obj_dummy->tx_msg_count = 0;
p_can_obj_dummy->rx_msg_count = 0;
p_can_obj_dummy->tx_failed_count = 0;
p_can_obj_dummy->rx_missed_count = 0;
p_can_obj_dummy->arb_lost_count = 0;
p_can_obj_dummy->bus_error_count = 0;
p_can_obj_dummy->alerts_enabled = g_config->alerts_enabled;
p_can_obj_dummy->alerts_triggered = 0;
//Initialize CAN peripheral registers, and allocate interrupt
CAN_ENTER_CRITICAL();
@ -719,40 +809,21 @@ esp_err_t can_driver_install(const can_general_config_t *g_config, const can_tim
can_config_error(DRIVER_DEFAULT_EWL, DRIVER_DEFAULT_REC, DRIVER_DEFAULT_TEC);
can_config_acceptance_filter(f_config->acceptance_code, f_config->acceptance_mask, f_config->single_filter);
can_config_clk_out(g_config->clkout_divider);
//Allocate GPIO and Interrupts
can_configure_gpio(g_config->tx_io, g_config->rx_io, g_config->clkout_io, g_config->bus_off_io);
(void) can_get_interrupt_reason(); //Read interrupt reg to clear it before allocating ISR
ESP_ERROR_CHECK(esp_intr_alloc(ETS_CAN_INTR_SOURCE, 0, can_intr_handler_main, NULL, &p_can_obj->isr_handle));
//Todo: Allow interrupt to be registered to specified CPU
CAN_EXIT_CRITICAL();
//Allocate GPIO and Interrupts
can_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_CAN_INTR_SOURCE, g_config->intr_flags, can_intr_handler_main, NULL, &p_can_obj->isr_handle));
#ifdef CONFIG_PM_ENABLE
ESP_ERROR_CHECK(esp_pm_lock_acquire(p_can_obj->pm_lock)); //Acquire pm_lock to keep APB clock at 80MHz
#endif
return ESP_OK; //CAN module is still in reset mode, users need to call can_start() afterwards
err:
//Cleanup CAN object and return error
if (p_can_obj_dummy != NULL) {
if (p_can_obj_dummy->tx_queue != NULL) {
vQueueDelete(p_can_obj_dummy->tx_queue);
p_can_obj_dummy->tx_queue = NULL;
}
if (p_can_obj_dummy->rx_queue != NULL) {
vQueueDelete(p_can_obj_dummy->rx_queue);
p_can_obj_dummy->rx_queue = NULL;
}
if (p_can_obj_dummy->alert_semphr != NULL) {
vSemaphoreDelete(p_can_obj_dummy->alert_semphr);
p_can_obj_dummy->alert_semphr = NULL;
}
#ifdef CONFIG_PM_ENABLE
if (p_can_obj_dummy->pm_lock != NULL) {
ESP_ERROR_CHECK(esp_pm_lock_delete(p_can_obj_dummy->pm_lock));
}
#endif
free(p_can_obj_dummy);
}
can_free_driver_obj(p_can_obj_dummy);
return ret;
}
@ -770,26 +841,17 @@ esp_err_t can_driver_uninstall()
(void) can_get_interrupt_reason();
(void) can_get_arbitration_lost_capture();
(void) can_get_error_code_capture();
ESP_ERROR_CHECK(esp_intr_free(p_can_obj->isr_handle)); //Free interrupt
periph_module_disable(PERIPH_CAN_MODULE); //Disable CAN peripheral
p_can_obj_dummy = p_can_obj; //Use dummy to shorten critical section
p_can_obj = NULL;
CAN_EXIT_CRITICAL();
//Delete queues, semaphores, and power management locks
if (p_can_obj_dummy->tx_queue != NULL) {
vQueueDelete(p_can_obj_dummy->tx_queue);
}
vQueueDelete(p_can_obj_dummy->rx_queue);
vSemaphoreDelete(p_can_obj_dummy->alert_semphr);
ESP_ERROR_CHECK(esp_intr_free(p_can_obj_dummy->isr_handle)); //Free interrupt
#ifdef CONFIG_PM_ENABLE
//Release and delete power management lock
ESP_ERROR_CHECK(esp_pm_lock_release(p_can_obj_dummy->pm_lock));
ESP_ERROR_CHECK(esp_pm_lock_delete(p_can_obj_dummy->pm_lock));
#endif
free(p_can_obj_dummy); //Free can driver object
can_free_driver_obj(p_can_obj_dummy);
return ESP_OK;
}
@ -953,15 +1015,16 @@ esp_err_t can_read_alerts(uint32_t *alerts, TickType_t ticks_to_wait)
esp_err_t can_reconfigure_alerts(uint32_t alerts_enabled, uint32_t *current_alerts)
{
CAN_CHECK(p_can_obj != NULL, ESP_ERR_INVALID_STATE);
CAN_ENTER_CRITICAL();
uint32_t cur_alerts;
can_read_alerts(&cur_alerts, 0); //Clear any unhandled alerts
//Clear any unhandled alerts
if (current_alerts != NULL) {
*current_alerts = p_can_obj->alerts_triggered;;
}
p_can_obj->alerts_triggered = 0;
p_can_obj->alerts_enabled = alerts_enabled; //Update enabled alerts
CAN_EXIT_CRITICAL();
if (current_alerts != NULL) {
*current_alerts = cur_alerts;
}
return ESP_OK;
}

6
components/driver/include/driver/can.h
View File

@ -37,7 +37,8 @@ extern "C" {
#define CAN_GENERAL_CONFIG_DEFAULT(tx_io_num, rx_io_num, op_mode) {.mode = op_mode, .tx_io = tx_io_num, .rx_io = rx_io_num, \
.clkout_io = CAN_IO_UNUSED, .bus_off_io = CAN_IO_UNUSED, \
.tx_queue_len = 5, .rx_queue_len = 5, \
.alerts_enabled = CAN_ALERT_NONE, .clkout_divider = 0, }
.alerts_enabled = CAN_ALERT_NONE, .clkout_divider = 0, \
.intr_flags = ESP_INTR_FLAG_LEVEL1}
/**
* @brief Initializer macros for timing configuration structure
@ -91,7 +92,7 @@ extern "C" {
#define CAN_ALERT_BUS_OFF 0x1000 /**< Alert(4096): Bus-off condition occurred. CAN controller can no longer influence bus */
#define CAN_ALERT_ALL 0x1FFF /**< Bit mask to enable all alerts during configuration */
#define CAN_ALERT_NONE 0x0000 /**< Bit mask to disable all alerts during configuration */
#define CAN_ALERT_AND_LOG 0x2000 /**< Bit mask to enable alerts to also be logged when they occur */
#define CAN_ALERT_AND_LOG 0x2000 /**< Bit mask to enable alerts to also be logged when they occur. Note that logging from the ISR is disabled if CONFIG_TWAI_ISR_IN_IRAM is enabled. */
/**
* @brief Message flags
@ -151,6 +152,7 @@ typedef struct {
uint32_t rx_queue_len; /**< Number of messages RX queue can hold */
uint32_t alerts_enabled; /**< Bit field of alerts to enable (see documentation) */
uint32_t clkout_divider; /**< CLKOUT divider. Can be 1 or any even number from 2 to 14 (optional, set to 0 if unused) */
int intr_flags; /**< Interrupt flags to set the priority of the driver's ISR. Note that to use the ESP_INTR_FLAG_IRAM, the CONFIG_CAN_ISR_IN_IRAM option should be enabled first. */
} can_general_config_t;
/**

4
components/soc/esp32/include/soc/can_struct.h
View File

@ -147,8 +147,8 @@ typedef struct {
typedef union {
struct {
uint32_t rx_message_counter: 5; /* RMC[4:0] RX Message Counter */
uint32_t reserved27: 27; /* Internal Reserved */
uint32_t rx_message_counter: 7; /* RMC[6:0] RX Message Counter */
uint32_t reserved25: 25; /* Internal Reserved */
};
uint32_t val;
} can_rx_msg_cnt_reg_t;

22
docs/en/api-reference/peripherals/can.rst
View File

@ -157,7 +157,10 @@ The CAN driver contains an alert feature which is used to notify the application
The **error warning limit** can be used to preemptively warn the application of bus errors before the error passive state is reached. By default the CAN driver sets the **error warning limit** to **96**. The ``CAN_ALERT_ABOVE_ERR_WARN`` is raised when the TEC or REC becomes larger then or equal to the error warning limit. The ``CAN_ALERT_BELOW_ERR_WARN`` is raised when both TEC and REC return back to values below **96**.
.. note::
When enabling alerts, the ``CAN_ALERT_AND_LOG`` flag can be used to cause the CAN driver to log any raised alerts to UART. The ``CAN_ALERT_ALL`` and ``CAN_ALERT_NONE`` macros can also be used to enable/disable all alerts during configuration/reconfiguration.
When enabling alerts, the ``CAN_ALERT_AND_LOG`` flag can be used to cause the CAN driver to log any raised alerts to UART. However, alert logging is disabled and ``CAN_ALERT_AND_LOG`` if the :ref:`CONFIG_CAN_ISR_IN_IRAM` option is enabled (see :ref:`placing-isr-into-iram`).
.. note::
The ``CAN_ALERT_ALL`` and ``CAN_ALERT_NONE`` macros can also be used to enable/disable all alerts during configuration/reconfiguration.
Bit Timing
^^^^^^^^^^
@ -223,6 +226,23 @@ Disabling TX Queue
The TX queue can be disabled during configuration by setting the ``tx_queue_len`` member of :cpp:type:`can_general_config_t` to ``0``. This will allow applications that do not require message transmission to save a small amount of memory when using the CAN driver.
.. _placing-isr-into-iram:
Placing ISR into IRAM
^^^^^^^^^^^^^^^^^^^^^
The CAN driver's ISR (Interrupt Service Routine) can be placed into IRAM so that the ISR can still run whilst the cache is disabled. Placing the ISR into IRAM may be necessary to maintain the CAN driver's functionality during lengthy cache disabling operations (such as SPI Flash writes, OTA updates etc). Whilst the cache is disabled, the ISR will continue to:
- Read received messages from the RX buffer and place them into the driver's RX queue.
- Load messages pending transmission from the driver's TX queue and write them into the TX buffer.
To place the CAN driver's ISR, users must do the following:
- Enable the :ref:`CONFIG_CAN_ISR_IN_IRAM` option using ``idf.py menuconfig``.
- When calling :cpp:func:`can_driver_install`, the `intr_flags` member of :cpp:type:`can_general_config_t` should set the :c:macro:`ESP_INTR_FLAG_IRAM` set.
.. note::
When the :ref:`CONFIG_CAN_ISR_IN_IRAM` option is enabled, the CAN driver will no longer log any alerts (i.e., the ``CAN_ALERT_AND_LOG`` flag will not have any effect).
.. -------------------------------- CAN Driver ---------------------------------