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b2f9e2c226
RIOT/cpu/esp32/periph/can.c
Marian Buschsieweke b2f9e2c226
cpu/esp32: fix wrong control flow
2021-11-17 13:10:37 +01:00

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/*
* Copyright (C) 2019 Gunar Schorcht
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @ingroup cpu_esp32
* @brief Implementation of the CAN controller driver for ESP32 (esp_can)
*
* @author Gunar Schorcht <gunar@schorcht.net>
* @file
* @{
*/
#include <assert.h>
#include <errno.h>
#include <string.h>
#include "can_esp.h"
#include "can_params.h"
#include "esp_attr.h"
#include "esp_common.h"
#include "gpio_arch.h"
#include "irq_arch.h"
#include "tools.h"
#include "can/common.h"
#include "can/device.h"
#include "driver/periph_ctrl.h"
#include "freertos/FreeRTOS.h"
#include "log.h"
#include "rom/ets_sys.h"
#include "periph/can.h"
#include "periph/gpio.h"
#include "soc/can_struct.h"
#include "soc/gpio_struct.h"
#include "xtensa/xtensa_api.h"
#define ENABLE_DEBUG 0
#include "debug.h"
/** Common ESP CAN definitions */
#define ESP_CAN_INTR_MASK (0xffU) /* interrupts handled by ESP CAN */
#define ESP_CAN_CLOCK APB_CLK_FREQ /* controller main clock */
/** Error mode limits used for ESP CAN */
#define ESP_CAN_ERROR_WARNING_LIMIT 96 /* indicator for heavy loaded bus */
#define ESP_CAN_ERROR_PASSIVE_LIMIT 128 /* switch to error passive state */
#define ESP_CAN_ERROR_BUS_OFF_LIMIT 256 /* switch to bus off state */
/* ESP32 CAN events */
#define ESP_CAN_EVENT_BUS_OFF (1 << 0)
#define ESP_CAN_EVENT_ERROR_WARNING (1 << 1)
#define ESP_CAN_EVENT_ERROR_PASSIVE (1 << 2)
#define ESP_CAN_EVENT_TX_ERROR (1 << 3)
#define ESP_CAN_EVENT_RX_ERROR (1 << 4)
#define ESP_CAN_EVENT_TX_CONFIRMATION (1 << 5)
#define ESP_CAN_EVENT_RX_INDICATION (1 << 6)
#define ESP_CAN_EVENT_ARBITRATION_LOST (1 << 7)
#define ESP_CAN_EVENT_WAKE_UP (1 << 8)
/* ESP32 CAN commands */
#define ESP_CMD_TX_REQ 0x01 /* Transmission Request */
#define ESP_CMD_ABORT_TX 0x02 /* Abort Transmission */
#define ESP_CMD_TX_SINGLE_SHOT 0x03 /* Single Shot Transmission */
#define ESP_CMD_RELEASE_RX_BUFF 0x04 /* Release Receive Buffer */
#define ESP_CMD_CLR_DATA_OVRN 0x08 /* Clear Data Overrun */
#define ESP_CMD_SELF_RX_REQ 0x10 /* Self Reception Request */
#define ESP_CMD_SELF_RX_SINGLE_SHOT 0x12 /* Single Shot Self Reception */
/**
* Frame format definition as it is expected/received in the TX/RX buffer
* of ESP32.
*/
#define ESP_CAN_SFF_ID_LEN 2 /* two byte (11 bit) in SFF ID format */
#define ESP_CAN_EFF_ID_LEN 4 /* two byte (29 bit) in EFF ID format */
#define ESP_CAN_MAX_DATA_LEN 8 /* 8 data bytes at maximum */
#define ESP_CAN_FRAME_LEN 13 /* 13 bytes at maximum */
typedef union esp_can_frame {
struct {
struct {
uint8_t dlc :4; /* frame payload length */
uint8_t zero:2; /* don't care, should be zero */
uint8_t rtr :1; /* remote transmission request frame */
uint8_t eff :1; /* extended ID frame format */
};
union {
struct {
uint8_t id[ESP_CAN_SFF_ID_LEN]; /* 11 bit standard frame identifier */
uint8_t data[ESP_CAN_MAX_DATA_LEN]; /* data bytes */
uint8_t reserved8[2];
} standard;
struct {
uint8_t id[ESP_CAN_EFF_ID_LEN]; /* 29 bit standard frame identifier */
uint8_t data[ESP_CAN_MAX_DATA_LEN]; /* data bytes */
} extended;
};
};
uint8_t bytes[ESP_CAN_FRAME_LEN];
} _esp_can_frame_t;
/* driver interface functions */
static int _esp_can_init(candev_t *candev);
static int _esp_can_send(candev_t *candev, const struct can_frame *frame);
static void _esp_can_isr(candev_t *candev);
static int _esp_can_set(candev_t *candev, canopt_t opt, void *value, size_t value_len);
static int _esp_can_get(candev_t *candev, canopt_t opt, void *value, size_t max_len);
static int _esp_can_abort(candev_t *candev, const struct can_frame *frame);
static int _esp_can_set_filter(candev_t *candev, const struct can_filter *filter);
static int _esp_can_remove_filter(candev_t *candev, const struct can_filter *filter);
/* internal function declarations, we don't need device since we habe only one */
static void _esp_can_set_bittiming (can_t *dev);
static void _esp_can_power_up(can_t *dev);
static void _esp_can_power_down(can_t *dev);
static void _esp_can_init_pins(can_t *dev);
static int _esp_can_set_mode(can_t *dev, canopt_state_t state);
static void IRAM_ATTR _esp_can_intr_handler (void *arg);
/** ESP32 CAN low level device driver data */
static const candev_driver_t _esp_can_driver = {
.send = _esp_can_send,
.init = _esp_can_init,
.isr = _esp_can_isr,
.get = _esp_can_get,
.set = _esp_can_set,
.abort = _esp_can_abort,
.set_filter = _esp_can_set_filter,
.remove_filter = _esp_can_remove_filter,
};
/** hardware dependent constants used for bit timing calculations */
static const struct can_bittiming_const bittiming_const = {
.tseg1_min = 1,
.tseg1_max = 16,
.tseg2_min = 1,
.tseg2_max = 8,
.sjw_max = 4,
.brp_min = 2,
.brp_max = 128,
.brp_inc = 2,
};
static void _esp_can_isr(candev_t *candev)
{
can_t *dev = (can_t *)candev;
DEBUG("%s candev=%p\n", __func__, candev);
assert(dev);
assert(dev->candev.event_callback);
if (dev->events & ESP_CAN_EVENT_BUS_OFF) {
dev->events &= ~ESP_CAN_EVENT_BUS_OFF;
dev->candev.event_callback(&dev->candev, CANDEV_EVENT_BUS_OFF, NULL);
}
if (dev->events & ESP_CAN_EVENT_ERROR_PASSIVE) {
dev->events &= ~ESP_CAN_EVENT_ERROR_PASSIVE;
dev->candev.event_callback(&dev->candev,
CANDEV_EVENT_ERROR_PASSIVE, NULL);
}
if (dev->events & ESP_CAN_EVENT_ERROR_WARNING) {
dev->events &= ~ESP_CAN_EVENT_ERROR_WARNING;
dev->candev.event_callback(&dev->candev,
CANDEV_EVENT_ERROR_WARNING, NULL);
}
if (dev->events & ESP_CAN_EVENT_TX_ERROR) {
/* a pending TX confirmation has also to be deleted on TX bus error */
dev->events &= ~ESP_CAN_EVENT_TX_ERROR;
dev->events &= ~ESP_CAN_EVENT_TX_CONFIRMATION;
if (dev->tx_frame) {
/* handle the event only if there is still a frame in TX buffer */
dev->candev.event_callback(&dev->candev,
CANDEV_EVENT_TX_ERROR, dev->tx_frame);
dev->tx_frame = NULL;
}
}
if (dev->events & ESP_CAN_EVENT_TX_CONFIRMATION) {
dev->events &= ~ESP_CAN_EVENT_TX_CONFIRMATION;
if (dev->tx_frame) {
/* handle the event only if there is still a frame in TX buffer */
dev->candev.event_callback(&dev->candev,
CANDEV_EVENT_TX_CONFIRMATION,
dev->tx_frame);
dev->tx_frame = NULL;
}
}
if (dev->events & ESP_CAN_EVENT_RX_ERROR) {
dev->events &= ~ESP_CAN_EVENT_RX_ERROR;
dev->candev.event_callback(&dev->candev, CANDEV_EVENT_RX_ERROR, NULL);
}
if (dev->events & ESP_CAN_EVENT_RX_INDICATION) {
dev->events &= ~ESP_CAN_EVENT_RX_INDICATION;
while (dev->rx_frames_num) {
dev->candev.event_callback(&dev->candev,
CANDEV_EVENT_RX_INDICATION,
&dev->rx_frames[dev->rx_frames_rptr]);
dev->rx_frames_num--;
dev->rx_frames_rptr++;
dev->rx_frames_rptr &= ESP_CAN_MAX_RX_FRAMES-1;
}
}
}
static int _esp_can_init(candev_t *candev)
{
can_t *dev = (can_t *)candev;
DEBUG("%s candev=%p\n", __func__, candev);
assert(dev);
/* initialize used GPIOs */
_esp_can_init_pins(dev);
/* power up and configure the CAN controller */
_esp_can_power_up(dev);
return 0;
}
static int _esp_can_send(candev_t *candev, const struct can_frame *frame)
{
can_t *dev = (can_t *)candev;
DEBUG("%s candev=%p frame=%p\n", __func__, candev, frame);
assert(dev);
assert(frame);
critical_enter();
/* check wthere the device is already transmitting a frame */
if (dev->tx_frame != NULL) {
critical_exit();
return -EBUSY;
}
/* save reference to frame in transmission (marks transmitter as busy) */
dev->tx_frame = (struct can_frame*)frame;
/* prepare the frame as expected by ESP32 */
_esp_can_frame_t esp_frame = {};
esp_frame.dlc = frame->can_dlc;
esp_frame.rtr = (frame->can_id & CAN_RTR_FLAG);
esp_frame.eff = (frame->can_id & CAN_EFF_FLAG);
/* esp_frame is a union that provides two views on the same memory: one
* tailored for efficient access and the other for readable code. Likely
* due to cppcheck not finding all headers it wrongly assumes that values
* are assigned but never read again (unreadVariable). But the union members
* are read via the aliases to the same memory. */
if (esp_frame.eff) {
uint32_t id = frame->can_id & CAN_EFF_MASK;
/* cppcheck-suppress unreadVariable */
esp_frame.extended.id[0] = (id >> 21) & 0xff;
/* cppcheck-suppress unreadVariable */
esp_frame.extended.id[1] = (id >> 13) & 0xff;
/* cppcheck-suppress unreadVariable */
esp_frame.extended.id[2] = (id >> 5) & 0xff;
/* cppcheck-suppress unreadVariable */
esp_frame.extended.id[3] = (id << 3) & 0xff;
}
else {
uint32_t id = frame->can_id & CAN_SFF_MASK;
/* cppcheck-suppress unreadVariable */
esp_frame.standard.id[0] = (id >> 3) & 0xff;
/* cppcheck-suppress unreadVariable */
esp_frame.standard.id[1] = (id << 5) & 0xff;
}
memcpy(esp_frame.eff ? &esp_frame.extended.data
: &esp_frame.standard.data, frame->data, ESP_CAN_MAX_DATA_LEN);
/* place the frame in TX buffer of ESP32 */
for (unsigned i = 0; i < ESP_CAN_FRAME_LEN; i++) {
CAN.tx_rx_buffer[i].val = esp_frame.bytes[i];
}
/* set the single shot transmit command without self-receiption */
CAN.command_reg.val = ESP_CMD_TX_SINGLE_SHOT;
critical_exit();
return 0;
}
static int _esp_can_set(candev_t *candev, canopt_t opt, void *value, size_t value_len)
{
can_t *dev = (can_t *)candev;
assert(dev);
assert(value);
int res = 0;
switch (opt) {
case CANOPT_BITTIMING:
DEBUG("%s CANOPT_BITTIMING\n", __func__);
if (value_len < sizeof(struct can_bittiming)) {
DEBUG("%s size error\n", __func__);
return -EOVERFLOW;
}
dev->candev.bittiming = *((struct can_bittiming*)value);
_esp_can_set_bittiming(dev);
res = sizeof(struct can_bittiming);
break;
case CANOPT_STATE:
DEBUG("%s CANOPT_STATE\n", __func__);
res = _esp_can_set_mode(dev, *((canopt_state_t *)value));
if (res == 0) {
res = sizeof(uint16_t);
}
break;
case CANOPT_TEC:
case CANOPT_REC:
DEBUG("%s %s\n", __func__, (opt == CANOPT_TEC) ? "CANOPT_TEC" : "CANOPT_REC");
if (value_len < sizeof(uint16_t)) {
DEBUG("%s size error\n", __func__);
return -EOVERFLOW;
}
if (opt == CANOPT_TEC) {
CAN.tx_error_counter_reg.byte = *((uint16_t*)value);
}
else {
CAN.rx_error_counter_reg.byte = *((uint16_t*)value);
}
res = sizeof(uint16_t);
break;
default:
DEBUG("%s not supported opt\n", __func__);
res = ENOTSUP;
}
return res;
}
static int _esp_can_get(candev_t *candev, canopt_t opt, void *value, size_t max_len)
{
can_t *dev = (can_t *)candev;
DEBUG("%s\n", __func__);
assert(dev);
assert(value);
int res = 0;
switch (opt) {
case CANOPT_BITTIMING:
DEBUG("%s CANOPT_BITTIMING\n", __func__);
if (max_len < sizeof(struct can_bittiming)) {
res = -EOVERFLOW;
break;
}
*((struct can_bittiming*)value) = dev->candev.bittiming;
res = sizeof(struct can_bittiming);
break;
case CANOPT_BITTIMING_CONST:
DEBUG("%s CANOPT_BITTIMING_CONST\n", __func__);
if (max_len < sizeof(struct can_bittiming_const)) {
res = -EOVERFLOW;
break;
}
*((struct can_bittiming_const*)value) = bittiming_const;
res = sizeof(struct can_bittiming_const);
break;
case CANOPT_CLOCK:
DEBUG("%s CANOPT_CLOCK\n", __func__);
if (max_len < sizeof(uint32_t)) {
res = -EOVERFLOW;
break;
}
*((uint32_t *)value) = APB_CLK_FREQ;
res = sizeof(uint32_t);
break;
case CANOPT_TEC:
case CANOPT_REC:
DEBUG("%s %s\n", __func__, (opt == CANOPT_TEC) ? "CANOPT_TEC" : "CANOPT_REC");
if (max_len < sizeof(uint16_t)) {
res = EOVERFLOW;
break;
}
if (opt == CANOPT_TEC) {
*((uint16_t *)value) = CAN.tx_error_counter_reg.byte;
}
else {
*((uint16_t *)value) = CAN.rx_error_counter_reg.byte;
}
res = sizeof(uint16_t);
break;
case CANOPT_RX_FILTERS:
if (max_len % sizeof(struct can_filter) != 0) {
res = -EOVERFLOW;
break;
}
struct can_filter *list = value;
unsigned filter_num_max = max_len / sizeof(struct can_filter);
unsigned filter_num = 0;
unsigned i;
for (i = 0; i < ESP_CAN_MAX_RX_FILTERS && filter_num < filter_num_max; i++) {
if (dev->rx_filters[i].can_id != 0) {
list[i] = dev->rx_filters[i];
filter_num++;
}
}
res = filter_num * sizeof(struct can_filter);
break;
default:
DEBUG("%s not supported opt\n", __func__);
res = -ENOTSUP;
}
return res;
}
static int _esp_can_abort(candev_t *candev, const struct can_frame *frame)
{
can_t *dev = (can_t *)candev;
DEBUG("%s candev=%p frame=%p\n", __func__, candev, frame);
assert(dev);
assert(frame);
/* abort transmission command */
CAN.command_reg.val = ESP_CMD_ABORT_TX;
/* mark the transmitter as free */
dev->tx_frame = NULL;
return -ENOTSUP;
}
static int _esp_can_set_filter(candev_t *candev, const struct can_filter *filter)
{
can_t *dev = (can_t *)candev;
DEBUG("%s candev=%p filter=%p\n", __func__, candev, filter);
assert(dev);
assert(filter);
int i;
/* first, check whether filter is already set */
for (i = 0; i < ESP_CAN_MAX_RX_FILTERS; i++) {
if (dev->rx_filters[i].can_id == filter->can_id) {
DEBUG("%s filter already set\n", __func__);
return i;
}
}
/* next, search for free filter entry */
for (i = 0; i < ESP_CAN_MAX_RX_FILTERS; i++) {
if (dev->rx_filters[i].can_id == 0) {
break;
}
}
if (i == ESP_CAN_MAX_RX_FILTERS) {
DEBUG("%s no more filters available\n", __func__);
return -EOVERFLOW;
}
/* set the filter and return the filter index */
dev->rx_filters[i] = *filter;
dev->rx_filter_num++;
return i;
}
static int _esp_can_remove_filter(candev_t *candev, const struct can_filter *filter)
{
can_t *dev = (can_t *)candev;
DEBUG("%s candev=%p filter=%p\n", __func__, candev, filter);
assert(dev);
assert(filter);
/* search for the filter */
for (unsigned i = 0; i < ESP_CAN_MAX_RX_FILTERS; i++) {
if (dev->rx_filters[i].can_id == filter->can_id) {
/* mark the filter entry as not in use */
dev->rx_filters[i].can_id = 0;
dev->rx_filter_num--;
return 0;
}
}
DEBUG("%s error filter not found\n", __func__);
return -EOVERFLOW;
}
/**
* Internal functions. All these functions have no dev parameter since
* they directly access the only one existing CAN controller.
*/
static void _esp_can_set_reset_mode(void)
{
DEBUG("%s\n", __func__);
while (CAN.mode_reg.reset != 1) {
CAN.mode_reg.reset = 1;
}
}
static void _esp_can_set_operating_mode(void)
{
DEBUG("%s\n", __func__);
while (CAN.mode_reg.reset != 0) {
CAN.mode_reg.reset = 0;
}
}
static int _esp_can_config(can_t *dev)
{
DEBUG("%s dev=%p\n", __func__, dev);
assert(dev);
critical_enter();
/* reset mode to be able to write configuration registers */
_esp_can_set_reset_mode();
/* configuration is done in listen only mode */
CAN.mode_reg.self_test = 0;
CAN.mode_reg.listen_only = 1;
/* Use SJA1000 PeliCAN mode and registers layout */
CAN.clock_divider_reg.can_mode = 1;
#ifndef ESP_CAN_CLK_OUT
CAN.clock_divider_reg.clock_off = 1;
CAN.clock_divider_reg.clock_divider = 0;
#else
uint32_t clk_out_div = ESP_CAN_CLK_OUT_DIV / 2 - 1;
clk_out_div = (clk_out_div < 7) ? clk_out_div : 7;
CAN.clock_divider_reg.clock_off = 0;
CAN.clock_divider_reg.clock_divider = clk_out_div;
#endif
/* set error counter values and warning limits */
CAN.error_warning_limit_reg.byte = ESP_CAN_ERROR_WARNING_LIMIT;
CAN.tx_error_counter_reg.byte = 0;
CAN.rx_error_counter_reg.byte = 0;
/* accept all CAN messages, filtering is done by software */
CAN.mode_reg.acceptance_filter = 0; /* single filter */
CAN.acceptance_filter.mask_reg[0].byte = 0xff; /* all bits masked */
CAN.acceptance_filter.mask_reg[1].byte = 0xff;
CAN.acceptance_filter.mask_reg[2].byte = 0xff;
CAN.acceptance_filter.mask_reg[3].byte = 0xff;
/* clear interrupt status register by read and enable all interrupts */
uint32_t tmp = CAN.interrupt_reg.val; (void)tmp;
CAN.interrupt_enable_reg.val = ESP_CAN_INTR_MASK;
/* route CAN interrupt source to CPU interrupt and enable it */
intr_matrix_set(PRO_CPU_NUM, ETS_CAN_INTR_SOURCE, CPU_INUM_CAN);
xt_set_interrupt_handler(CPU_INUM_CAN, _esp_can_intr_handler, (void*)dev);
xt_ints_on(BIT(CPU_INUM_CAN));
/* set bittiming from parameters as given in device data */
_esp_can_set_bittiming(dev);
/* switch to operating mode */
_esp_can_set_operating_mode();
critical_exit();
return 0;
}
static void _esp_can_power_up(can_t *dev)
{
assert(dev);
/* just return when already powered up */
if (dev->powered_up) {
return;
}
DEBUG("%s dev=%p\n", __func__, dev);
critical_enter();
/* power up and (re)configure the CAN controller */
periph_module_enable(PERIPH_CAN_MODULE);
dev->powered_up = true;
_esp_can_config (dev);
critical_exit();
}
static void _esp_can_power_down(can_t *dev)
{
assert(dev);
/* just return when already powered down */
if (!dev->powered_up) {
return;
}
DEBUG("%s dev=%p\n", __func__, dev);
/* power down the CAN controller */
periph_module_disable(PERIPH_CAN_MODULE);
dev->powered_up = false;
}
static void _esp_can_init_pins(can_t *dev)
{
DEBUG("%s dev=%p\n", __func__, dev);
assert(dev);
/* Init TX pin */
gpio_init(dev->tx_pin, GPIO_OUT);
gpio_set_pin_usage(dev->tx_pin, _CAN);
GPIO.func_out_sel_cfg[dev->tx_pin].func_sel = CAN_TX_IDX;
/* Init RX pin */
gpio_init(dev->rx_pin, GPIO_IN);
gpio_set_pin_usage(dev->rx_pin, _CAN);
GPIO.func_in_sel_cfg[CAN_RX_IDX].sig_in_sel = 1;
GPIO.func_in_sel_cfg[CAN_RX_IDX].sig_in_inv = 0;
GPIO.func_in_sel_cfg[CAN_RX_IDX].func_sel = dev->rx_pin;
#ifdef ESP_CAN_CLK_OUT
/* Init CLK_OUT pin (optional) if defined */
gpio_init(dev->clk_out_pin, GPIO_OD);
gpio_set_pin_usage(dev->clk_out_pin, _CAN);
GPIO.func_out_sel_cfg[dev->clk_out_pin].func_sel = CAN_CLKOUT_IDX;
#endif
/* Init BUS_ON_OFF pin pin (optional) if defined */
#ifdef ESP_CAN_BUS_ON_OFF
gpio_init(dev->bus_on_of_pin, GPIO_OD);
gpio_set_pin_usage(dev->bus_on_of_pin, _CAN);
GPIO.func_out_sel_cfg[dev->bus_on_of_pin].func_sel = CAN_BUS_OFF_ON_IDX;
#endif
}
static int _esp_can_set_mode(can_t *dev, canopt_state_t state)
{
DEBUG("%s dev=%p state=%d\n", __func__, dev, state);
assert(dev);
critical_enter();
switch (state) {
case CANOPT_STATE_OFF:
/* just power down the CAN controller */
_esp_can_power_down(dev);
break;
case CANOPT_STATE_LISTEN_ONLY:
/* power up and (re)configure the CAN controller if necessary */
_esp_can_power_up(dev);
/* set the new mode (has to be done in reset mode) */
_esp_can_set_reset_mode();
CAN.mode_reg.self_test = 0;
CAN.mode_reg.listen_only = 1;
_esp_can_set_operating_mode ();
break;
case CANOPT_STATE_SLEEP:
/* Sleep mode is not supported by ESP32, State On is used instead. */
#if 0
/* power up and (re)configure the CAN controller if necessary */
_esp_can_power_up(dev);
/* set the sleep mode (not necessary to set reset mode before) */
CAN.mode_reg.sleep_mode = 1;
break;
#endif
case CANOPT_STATE_ON:
/* power up and (re)configure the CAN controller if necessary */
_esp_can_power_up(dev);
/* set the new mode (has to be done in reset mode) */
_esp_can_set_reset_mode();
CAN.mode_reg.self_test = 0;
CAN.mode_reg.listen_only = 0;
_esp_can_set_operating_mode ();
break;
default:
LOG_TAG_ERROR ("esp_can", "state value %d not supported\n", state);
break;
}
dev->state = state;
critical_exit();
return 0;
}
static void IRAM_ATTR _esp_can_intr_handler(void *arg)
{
can_t* dev = (can_t *)arg;
assert(arg);
critical_enter();
/* read the registers to clear them */
can_status_reg_t sta_reg = CAN.status_reg;
can_intr_reg_t int_reg = CAN.interrupt_reg;
DEBUG("%s int=%08x sta=%08x\n", __func__, int_reg.val, sta_reg.val);
/* Wake-Up Interrupt (not supported by ESP32) */
if (int_reg.reserved1) {
DEBUG("%s wake-up interrupt\n", __func__);
dev->events |= ESP_CAN_EVENT_WAKE_UP;
}
/* Arbitration Lost Interrupt */
if (int_reg.arb_lost) {
DEBUG("%s arbitration lost interrupt\n", __func__);
/* can only happen during transmission, handle it as error in single shot transmission */
dev->events |= ESP_CAN_EVENT_TX_ERROR;
}
/* bus or error status has changed, handle this first */
if (int_reg.err_warn) {
/* BUS_OFF state condition */
if (sta_reg.error && sta_reg.bus) {
DEBUG("%s bus-off state interrupt\n", __func__);
/* switch to listen only mode to freeze the RX error counter */
_esp_can_set_mode (dev, CANOPT_STATE_LISTEN_ONLY);
/* save the event */
dev->events |= ESP_CAN_EVENT_BUS_OFF;
}
/* ERROR_WARNING state condition, RX/TX error counter are > 96 */
else if (sta_reg.error && !sta_reg.bus) {
DEBUG("%s error warning interrupt\n", __func__);
/* save the event */
dev->events |= ESP_CAN_EVENT_ERROR_WARNING;
}
}
/* enter to / return from ERROR_PASSIVE state */
if (int_reg.err_passive) {
/* enter to the ERROR_PASSIVE state when one of the error counters is >= 128 */
if (CAN.tx_error_counter_reg.byte >= ESP_CAN_ERROR_PASSIVE_LIMIT ||
CAN.rx_error_counter_reg.byte >= ESP_CAN_ERROR_PASSIVE_LIMIT) {
DEBUG("%s error passive interrupt %d %d\n", __func__,
CAN.tx_error_counter_reg.byte,
CAN.rx_error_counter_reg.byte);
/* save the event */
dev->events |= ESP_CAN_EVENT_ERROR_PASSIVE;
}
}
/*
* Bus Error Interrupt (bit, stuff, crc, form, ack), details are captured
* in ECC register (see SJA1000 Data sheet, Table 20 and 21)
*/
if (int_reg.bus_err) {
can_err_code_cap_reg_t ecc = CAN.error_code_capture_reg;
/* save the event */
DEBUG("%s bus error interrupt, ecc=%08x\n", __func__, ecc.val);
dev->events |= ecc.direction ? ESP_CAN_EVENT_RX_ERROR
: ESP_CAN_EVENT_TX_ERROR;
}
/* TX buffer becomes free */
if (int_reg.tx) {
DEBUG("%s transmit interrupt\n", __func__);
/* save the event */
dev->events |= ESP_CAN_EVENT_TX_CONFIRMATION;
}
/* RX buffer has one or more frames */
if (int_reg.rx) {
/* get the number of messages in receive buffer */
uint32_t msg_cnt = CAN.rx_message_counter_reg.val;
DEBUG("%s receive interrupt, msg_cnt=%d\n", __func__, msg_cnt);
for (unsigned i = 0; i < msg_cnt; i++) {
_esp_can_frame_t esp_frame;
/* fetch the frame from RX buffer of ESP32 */
for (unsigned j = 0; j < ESP_CAN_FRAME_LEN; j++) {
esp_frame.bytes[j] = CAN.tx_rx_buffer[j].val;
}
/* clear RX buffer at read position */
CAN.command_reg.val = ESP_CMD_RELEASE_RX_BUFF;
if (dev->rx_frames_num < ESP_CAN_MAX_RX_FRAMES) {
/* prepare the CAN frame from ESP32 CAN frame */
struct can_frame frame = {};
if (esp_frame.eff) {
frame.can_id = esp_frame.extended.id[0];
frame.can_id = (frame.can_id << 8) | esp_frame.extended.id[1];
frame.can_id = (frame.can_id << 8) | esp_frame.extended.id[2];
frame.can_id = (frame.can_id << 5) | (esp_frame.extended.id[3] >> 3);
memcpy(frame.data, &esp_frame.extended.data, CAN_MAX_DLEN);
}
else {
frame.can_id = esp_frame.standard.id[0];
frame.can_id = (frame.can_id << 3) | (esp_frame.standard.id[1] >> 5);
memcpy(frame.data, &esp_frame.standard.data, CAN_MAX_DLEN);
}
frame.can_id |= esp_frame.rtr ? CAN_RTR_FLAG : 0;
frame.can_id |= esp_frame.eff ? CAN_EFF_FLAG : 0;
frame.can_dlc = esp_frame.dlc;
/* apply acceptance filters only if they are set */
unsigned f_id = 0;
if (dev->rx_filter_num) {
for (f_id = 0; f_id < ESP_CAN_MAX_RX_FILTERS; f_id++) {
/* compared masked can_id with each filter */
struct can_filter* f = &dev->rx_filters[f_id];
if ((f->can_mask & f->can_id) ==
(f->can_mask & frame.can_id)) {
/* break the loop on first match */
break;
}
}
}
/*
* put the frame in the RX ring buffer if there are no
* acceptance filters (f_id == 0) or one filter matched
* (f_id < ESP_CAN_MAX_RX_FILTERS), otherwise drop it.
*/
if (f_id < ESP_CAN_MAX_RX_FILTERS) {
dev->rx_frames[dev->rx_frames_wptr] = frame;
dev->rx_frames_num++;
dev->rx_frames_wptr++;
dev->rx_frames_wptr &= ESP_CAN_MAX_RX_FRAMES-1;
}
}
else {
DEBUG("%s receive buffer overrun\n", __func__);
/* we use rx error since there is no separate overrun error */
dev->events |= ESP_CAN_EVENT_RX_ERROR;
}
}
/* save the event */
dev->events |= ESP_CAN_EVENT_RX_INDICATION;
}
/* data overrun interrupts are not handled */
if (int_reg.data_overrun) {
DEBUG("%s data overrun interrupt\n", __func__);
/* we use rx error since there is no separate overrun error */
dev->events |= ESP_CAN_EVENT_RX_INDICATION;
}
DEBUG("%s events=%08x\n", __func__, dev->events);
/* inform the upper layer that there are events to be handled */
if (dev->events && dev->candev.event_callback) {
dev->candev.event_callback(&dev->candev, CANDEV_EVENT_ISR, NULL);
}
critical_exit();
}
static void _esp_can_set_bittiming(can_t *dev)
{
assert(dev);
struct can_bittiming* timing = &dev->candev.bittiming;
DEBUG("%s %p bitrate=%d, brp=%d, sample_point=%d, tq=%d, "
"prop_seg=%d phase_seg1=%d, phase_seg2=%d, sjw =%d\n", __func__, dev,
timing->bitrate, timing->brp, timing->sample_point, timing->tq,
timing->prop_seg, timing->phase_seg1, timing->phase_seg2,
timing->sjw);
can_bus_tim_0_reg_t reg_0;
can_bus_tim_1_reg_t reg_1;
/* Again cppcheck gets off rails due to missing concept of union (see
* explanation above), so we suppress false unreadVariable here */
/* cppcheck-suppress unreadVariable */
reg_0.baud_rate_prescaler = (timing->brp / 2) - 1;
/* cppcheck-suppress unreadVariable */
reg_0.sync_jump_width = timing->sjw - 1;
/* cppcheck-suppress unreadVariable */
reg_1.time_seg_1 = (timing->prop_seg + timing->phase_seg1) - 1;
/* cppcheck-suppress unreadVariable */
reg_1.time_seg_2 = timing->phase_seg2 - 1;
/* cppcheck-suppress unreadVariable */
reg_1.sampling = 0;
_esp_can_set_reset_mode();
CAN.bus_timing_0_reg.val = reg_0.val;
CAN.bus_timing_1_reg.val = reg_1.val;
_esp_can_set_operating_mode();
}
void can_init(can_t *dev, const can_conf_t *conf)
{
DEBUG("%s dev=%p conf=%p\n", __func__, dev, conf);
assert(dev);
assert(conf);
dev->candev.driver = &_esp_can_driver;
dev->candev.bittiming.bitrate = conf->bitrate;
dev->tx_pin = conf->tx_pin;
dev->rx_pin = conf->rx_pin;
#ifdef ESP_CAN_CLK_OUT
dev->clk_out_pin = conf->clk_out_pin;
#endif
#ifdef ESP_CAN_BUS_ON_OFF
dev->bus_on_off_pin = conf->bus_on_off_pin;
#endif
/* determine the hardware bittiming constants */
struct can_bittiming_const timing_const = bittiming_const;
/* calculate the initial bittimings from the bittiming constants */
can_device_calc_bittiming (ESP_CAN_CLOCK, &timing_const, &dev->candev.bittiming);
/* initialize other members */
dev->state = CAN_STATE_SLEEPING;
dev->tx_frame = NULL;
dev->rx_frames_wptr = 0;
dev->rx_frames_rptr = 0;
dev->rx_frames_num = 0;
dev->rx_filter_num = 0;
dev->powered_up = false;
}
void can_print_config(void)
{
printf("\tCAN_DEV(0)\ttxd=%d rxd=%d\n", CAN_TX, CAN_RX);
}
/**@}*/
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