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samples: can: Add example code for CAN driver
This adds example and testing code for CAN driver. Tested on stm32f072b disco. Examples are given for: - can_configure - can_attach_isr - can_attach_msgq - can_send Signed-off-by: Alexander Wachter <[email protected]>
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‎include/can.h‎

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@@ -329,7 +329,7 @@ __syscall int can_attach_msgq(struct device *dev, struct k_msgq *msg_q,
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static inline int _impl_can_attach_msgq(struct device *dev,
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struct k_msgq *msg_q,
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struct can_filter *filter)
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const struct can_filter *filter)
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{
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const struct can_driver_api *api = dev->driver_api;
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‎samples/can/CMakeLists.txt‎

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set(KCONFIG_ROOT ${CMAKE_CURRENT_SOURCE_DIR}/Kconfig)
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include($ENV{ZEPHYR_BASE}/cmake/app/boilerplate.cmake NO_POLICY_SCOPE)
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project(NONE)
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target_sources(app PRIVATE src/main.c)

‎samples/can/Kconfig‎

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# Kconfig - Private config options for can sample app
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#
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# Copyright (c) 2018 Alexander Wachter
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#
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# SPDX-License-Identifier: Apache-2.0
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#
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mainmenu "Controller Area Network sample application"
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config ZEPHYR_BASE
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string
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option env="ZEPHYR_BASE"
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source "$ZEPHYR_BASE/Kconfig.zephyr"
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config CAN_DEV
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string "Name of the CAN device"
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default "CAN_1"
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help
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Name of the can device used for send an receive.
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config GPIO_LED_DEV
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string "Name of the LED GPIO port"
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default "GPIOC"
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help
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Name of the LED port for signaling message reception.
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config GPIO_BUTTON_DEV
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string "Name of the button GPIO port"
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default "GPIOA"
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help
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Name of the button port for triggering messages.
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config PIN_USER_BUTTON
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int "Pin User Button"
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default 0
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help
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Pin number of the user Button.
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config PIN_LED_1
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int "Pin LED 1"
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default 6
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help
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Pin number of the first LED.
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config LOOPBACK_MODE
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bool "Loopback LOOPBACK_MODE"
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default y
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help
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Set the controller to loopback mode.
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This allows testing without a second board.

‎samples/can/README.rst‎

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.. _can-sample:
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Controller Area Network
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#######################
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Overview
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********
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This sample demonstrates how to use the Controller Area Network (CAN) API.
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Messages with standard and extended identifiers are sent over the bus, triggered
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by a button event.
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Messages are received using message queues and ISRs.
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Reception is indicated by blink LEDs and output to the console.
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Building and Running
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********************
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In loopback mode, the board receives its own messages. This could be used for
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standalone testing.
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The sample can be built and executed on boards supporting CAN.
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The output ports and pins of the LEDs can be configured by Kconfig.
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Sample output
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=============
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.. code-block:: console
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Finished init. waiting for Interrupts
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TX thread is running.
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filter id: 1
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Button pressed! Send message 1
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Button pressed 1 times
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Button pressed! Send message 0
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Button pressed 2 times
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String sent over CAN
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Button pressed! Send message 1
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Button pressed 3 times
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Button pressed! Send message 0
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Button pressed 4 times
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String sent over CAN
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.. note:: The values shown above might differ.

‎samples/can/prj.conf‎

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CONFIG_CAN=y
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CONFIG_CAN_INIT_PRIORITY=80
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CONFIG_CAN_PHASE_SEG1_PROP_SEG=5
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CONFIG_CAN_PHASE_SEG2=6
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CONFIG_CAN_SJW=1
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CONFIG_CAN_1=y
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CONFIG_CAN_STM32=y
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CONFIG_CAN_MAX_FILTER=5

‎samples/can/src/main.c‎

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/*
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* Copyright (c) 2018 Alexander Wachter
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <zephyr.h>
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#include <kernel.h>
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#include <misc/printk.h>
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#include <device.h>
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#include <can.h>
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#include <gpio.h>
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#define TX_THREAD_STACK_SIZE 512
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#define LED_THREAD_STACK_SIZE 512
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#define RX_STR_THREAD_STACK_SIZE 512
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#define TX_THREAD_PRIORITY 2
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#define LED_MSG_ID (0x10)
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#define BUTTON_MSG_ID (0x01)
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#define STR_MSG_ID (0x12345)
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#define SET_LED 0
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#define RESET_LED 1
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#define NUM_LEDS_STR STRINGIFY(NUM_LEDS)
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K_THREAD_STACK_DEFINE(tx_thread_stack, TX_THREAD_STACK_SIZE);
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K_THREAD_STACK_DEFINE(led_thread_stack, LED_THREAD_STACK_SIZE);
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K_THREAD_STACK_DEFINE(rx_str_thread_stack, RX_STR_THREAD_STACK_SIZE);
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struct k_thread tx_thread_data;
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struct k_thread led_thread_data;
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struct k_thread rx_str_thread_data;
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struct k_sem tx_sem;
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static struct gpio_callback gpio_cb;
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CAN_DEFINE_MSGQ(led_msgq, 2);
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CAN_DEFINE_MSGQ(str_msgq, 5);
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void tx_irq_callback(u32_t error_flags)
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{
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if (error_flags) {
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printk("Callback! error-code: %d\n", error_flags);
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}
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}
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void button_callback(struct device *port,
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struct gpio_callback *cb, u32_t pins)
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{
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k_sem_give(&tx_sem);
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}
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void send_string(char *string, struct device *can_dev)
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{
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struct can_msg msg;
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int str_len;
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msg.ext_id = STR_MSG_ID;
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msg.id_type = CAN_EXTENDED_IDENTIFIER;
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msg.dlc = 0;
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msg.rtr = CAN_DATAFRAME;
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for (str_len = strlen(string); str_len; ) {
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msg.dlc = str_len >= 8 ? 8 : str_len;
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str_len -= msg.dlc;
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memcpy(msg.data, string, msg.dlc);
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string += msg.dlc;
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can_send(can_dev, &msg, 10, tx_irq_callback);
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}
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}
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void tx_thread(void *can_dev_param, void *unused2, void *unused3)
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{
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u8_t toggle = SET_LED;
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u16_t button_press_cnt = 0;
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struct can_msg msg;
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struct can_msg msg_button_cnt;
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struct device *can_dev = can_dev_param;
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msg.std_id = LED_MSG_ID;
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msg.id_type = CAN_STANDARD_IDENTIFIER;
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msg.dlc = 1;
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msg.rtr = CAN_DATAFRAME;
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msg.data[0] = 0;
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msg_button_cnt.std_id = BUTTON_MSG_ID;
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msg_button_cnt.id_type = CAN_STANDARD_IDENTIFIER;
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msg_button_cnt.dlc = 2;
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msg_button_cnt.rtr = CAN_DATAFRAME;
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msg_button_cnt.data[0] = 0;
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msg_button_cnt.data[1] = 0;
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printk("TX thread is running.\n");
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while (1) {
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k_sem_take(&tx_sem, K_FOREVER);
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button_press_cnt++;
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toggle = (toggle == SET_LED) ? RESET_LED : SET_LED;
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printk("Button pressed! Send message %u\n", toggle);
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msg.data[0] = toggle;
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msg_button_cnt.data[0] = button_press_cnt & 0xFF;
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msg_button_cnt.data[1] = (button_press_cnt >> 8) & 0xFF;
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can_send(can_dev, &msg, 10, tx_irq_callback);
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can_send(can_dev, &msg_button_cnt, 10, NULL);
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if (toggle == SET_LED) {
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send_string("String sent over CAN\n", can_dev);
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}
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}
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}
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void rx_str_thread(void *msgq, void *can_dev_param, void *unused)
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{
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struct can_msg msg;
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const struct can_filter filter = {
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.id_type = CAN_EXTENDED_IDENTIFIER,
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.rtr = CAN_DATAFRAME,
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.ext_id = STR_MSG_ID,
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.rtr_mask = 1,
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.ext_id_mask = CAN_EXT_ID_MASK
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};
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struct device *can_dev = can_dev_param;
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can_attach_msgq(can_dev, msgq, &filter);
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while (1) {
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k_msgq_get((struct k_msgq *)msgq, &msg, K_FOREVER);
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for (int i = 0; i < msg.dlc; i++)
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printk("%c", msg.data[i]);
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}
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}
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void led_thread(void *msgq, void *can_dev_param, void *gpio_dev_param)
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{
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const struct can_filter filter = {
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.id_type = CAN_STANDARD_IDENTIFIER,
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.rtr = CAN_DATAFRAME,
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.std_id = LED_MSG_ID,
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.rtr_mask = 1,
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.std_id_mask = CAN_STD_ID_MASK
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};
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struct device *can_dev = can_dev_param;
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struct device *gpio_dev = gpio_dev_param;
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struct can_msg msg;
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int ret;
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int filter_id;
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ret = gpio_pin_configure(gpio_dev, CONFIG_PIN_LED_1, GPIO_DIR_OUT);
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gpio_pin_write(gpio_dev, CONFIG_PIN_LED_1, 0);
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if (ret) {
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printk("ERROR configure pins\n");
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return;
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}
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filter_id = can_attach_msgq(can_dev, msgq, &filter);
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printk("filter id: %d\n", filter_id);
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while (1) {
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k_msgq_get((struct k_msgq *)msgq, &msg, K_FOREVER);
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if (msg.dlc != 1) {
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continue;
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}
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switch (msg.data[0]) {
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case SET_LED:
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gpio_pin_write(gpio_dev, CONFIG_PIN_LED_1, 1);
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break;
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case RESET_LED:
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gpio_pin_write(gpio_dev, CONFIG_PIN_LED_1, 0);
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break;
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}
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}
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}
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void rx_button_isr(struct can_msg *msg)
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{
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u16_t cnt = msg->data[0] | (msg->data[1] << 8);
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printk("Button pressed %d times\n", cnt);
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}
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void main(void)
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{
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const struct can_filter filter = {
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.id_type = CAN_STANDARD_IDENTIFIER,
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.rtr = CAN_DATAFRAME,
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.std_id = BUTTON_MSG_ID,
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.rtr_mask = 1,
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.std_id_mask = CAN_STD_ID_MASK
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};
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struct device *can_dev, *led_gpio_dev, *button_gpio_dev;
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int ret;
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can_dev = device_get_binding(CONFIG_CAN_DEV);
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if (!can_dev) {
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printk("CAN: Device driver not found.\n");
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return;
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}
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#ifdef CONFIG_LOOPBACK_MODE
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can_configure(can_dev, CAN_LOOPBACK_MODE, 250000);
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#endif
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led_gpio_dev = device_get_binding(CONFIG_GPIO_LED_DEV);
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if (!led_gpio_dev) {
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printk("LED: Device driver not found.\n");
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return;
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}
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k_sem_init(&tx_sem, 0, INT_MAX);
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button_gpio_dev = device_get_binding(CONFIG_GPIO_BUTTON_DEV);
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if (!button_gpio_dev) {
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printk("Button: Device driver not found.\n");
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return;
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}
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ret = gpio_pin_configure(button_gpio_dev, CONFIG_PIN_USER_BUTTON,
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(GPIO_DIR_IN | GPIO_INT | GPIO_INT_EDGE |
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GPIO_INT_ACTIVE_HIGH | GPIO_INT_DEBOUNCE));
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if (ret) {
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printk("Error configuring button pin\n");
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}
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gpio_init_callback(&gpio_cb, button_callback,
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BIT(CONFIG_PIN_USER_BUTTON));
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ret = gpio_add_callback(button_gpio_dev, &gpio_cb);
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if (ret) {
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printk("Cannot setup callback!\n");
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}
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ret = gpio_pin_enable_callback(button_gpio_dev, CONFIG_PIN_USER_BUTTON);
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if (ret) {
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printk("Error enabling callback!\n");
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}
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can_attach_isr(can_dev, rx_button_isr, &filter);
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k_tid_t tx_tid = k_thread_create(&tx_thread_data, tx_thread_stack,
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K_THREAD_STACK_SIZEOF(tx_thread_stack),
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tx_thread,
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can_dev, NULL, NULL,
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TX_THREAD_PRIORITY, 0, K_NO_WAIT);
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if (!tx_tid) {
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printk("ERROR spawning tx_thread\n");
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}
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k_tid_t led_tid = k_thread_create(&led_thread_data, led_thread_stack,
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K_THREAD_STACK_SIZEOF(led_thread_stack),
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led_thread,
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&led_msgq, can_dev, led_gpio_dev,
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TX_THREAD_PRIORITY, 0, K_NO_WAIT);
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if (!led_tid) {
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printk("ERROR spawning led_thread\n");
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}
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k_tid_t str_tid = k_thread_create(&rx_str_thread_data,
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rx_str_thread_stack,
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K_THREAD_STACK_SIZEOF(rx_str_thread_stack),
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rx_str_thread,
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&str_msgq, can_dev, NULL,
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TX_THREAD_PRIORITY, 0, K_NO_WAIT);
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if (!str_tid) {
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printk("ERROR spawning str_thread\n");
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}
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printk("Finished init. waiting for Interrupts\n");
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}

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