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 <alexander.wachter@student.tugraz.at>

include/can.h

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

samples/can/CMakeLists.txt

@@ -0,0 +1,7 @@
+
+set(KCONFIG_ROOT ${CMAKE_CURRENT_SOURCE_DIR}/Kconfig)
+
+include($ENV{ZEPHYR_BASE}/cmake/app/boilerplate.cmake NO_POLICY_SCOPE)
+project(NONE)
+
+target_sources(app PRIVATE src/main.c)

samples/can/Kconfig

@@ -0,0 +1,52 @@
+# Kconfig - Private config options for can sample app
+
+#
+# Copyright (c) 2018 Alexander Wachter
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+mainmenu "Controller Area Network sample application"
+
+config ZEPHYR_BASE
+	string
+	option env="ZEPHYR_BASE"
+
+source "$ZEPHYR_BASE/Kconfig.zephyr"
+
+config CAN_DEV
+	string "Name of the CAN device"
+	default "CAN_1"
+	help
+	  Name of the can device used for send an receive.
+
+config GPIO_LED_DEV
+	string "Name of the LED GPIO port"
+	default "GPIOC"
+	help
+	  Name of the LED port for signaling message reception.
+
+config GPIO_BUTTON_DEV
+	string "Name of the button GPIO port"
+	default "GPIOA"
+	help
+	  Name of the button port for triggering messages.
+
+config PIN_USER_BUTTON
+	int "Pin User Button"
+	default 0
+	help
+	  Pin number of the user Button.
+
+config PIN_LED_1
+	int "Pin LED 1"
+	default 6
+	help
+	  Pin number of the first LED.
+
+config LOOPBACK_MODE
+	bool "Loopback LOOPBACK_MODE"
+	default y
+	help
+	  Set the controller to loopback mode.
+	  This allows testing without a second board.

samples/can/README.rst

@@ -0,0 +1,43 @@
+.. _can-sample:
+
+Controller Area Network
+#######################
+
+Overview
+********
+
+This sample demonstrates how to use the Controller Area Network (CAN) API.
+Messages with standard and extended identifiers are sent over the bus, triggered
+by a button event.
+Messages are received using message queues and ISRs.
+Reception is indicated by blink LEDs and output to the console.
+
+Building and Running
+********************
+
+In loopback mode, the board receives its own messages. This could be used for
+standalone testing.
+
+The sample can be built and executed on boards supporting CAN.
+The output ports and pins of the LEDs can be configured by Kconfig.
+
+Sample output
+=============
+
+.. code-block:: console
+
+   Finished init. waiting for Interrupts
+   TX thread is running.
+   filter id: 1
+   Button pressed! Send message 1
+   Button pressed 1 times
+   Button pressed! Send message 0
+   Button pressed 2 times
+   String sent over CAN
+   Button pressed! Send message 1
+   Button pressed 3 times
+   Button pressed! Send message 0
+   Button pressed 4 times
+   String sent over CAN
+
+.. note:: The values shown above might differ.

samples/can/prj.conf

@@ -0,0 +1,8 @@
+CONFIG_CAN=y
+CONFIG_CAN_INIT_PRIORITY=80
+CONFIG_CAN_PHASE_SEG1_PROP_SEG=5
+CONFIG_CAN_PHASE_SEG2=6
+CONFIG_CAN_SJW=1
+CONFIG_CAN_1=y
+CONFIG_CAN_STM32=y
+CONFIG_CAN_MAX_FILTER=5

samples/can/src/main.c

@@ -0,0 +1,269 @@
+/*
+ * Copyright (c) 2018 Alexander Wachter
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr.h>
+#include <kernel.h>
+#include <misc/printk.h>
+#include <device.h>
+#include <can.h>
+#include <gpio.h>
+
+#define TX_THREAD_STACK_SIZE 512
+#define LED_THREAD_STACK_SIZE 512
+#define RX_STR_THREAD_STACK_SIZE 512
+#define TX_THREAD_PRIORITY 2
+#define LED_MSG_ID (0x10)
+#define BUTTON_MSG_ID (0x01)
+#define STR_MSG_ID (0x12345)
+
+#define SET_LED 0
+#define RESET_LED 1
+
+
+#define NUM_LEDS_STR STRINGIFY(NUM_LEDS)
+
+K_THREAD_STACK_DEFINE(tx_thread_stack, TX_THREAD_STACK_SIZE);
+K_THREAD_STACK_DEFINE(led_thread_stack, LED_THREAD_STACK_SIZE);
+K_THREAD_STACK_DEFINE(rx_str_thread_stack, RX_STR_THREAD_STACK_SIZE);
+struct k_thread tx_thread_data;
+struct k_thread led_thread_data;
+struct k_thread rx_str_thread_data;
+struct k_sem tx_sem;
+static struct gpio_callback gpio_cb;
+CAN_DEFINE_MSGQ(led_msgq, 2);
+CAN_DEFINE_MSGQ(str_msgq, 5);
+
+void tx_irq_callback(u32_t error_flags)
+{
+	if (error_flags) {
+		printk("Callback! error-code: %d\n", error_flags);
+	}
+}
+
+void button_callback(struct device *port,
+		     struct gpio_callback *cb, u32_t pins)
+{
+	k_sem_give(&tx_sem);
+}
+
+void send_string(char *string, struct device *can_dev)
+{
+	struct can_msg msg;
+	int str_len;
+
+	msg.ext_id = STR_MSG_ID;
+	msg.id_type = CAN_EXTENDED_IDENTIFIER;
+	msg.dlc = 0;
+	msg.rtr = CAN_DATAFRAME;
+
+	for (str_len = strlen(string); str_len; ) {
+		msg.dlc = str_len >= 8 ? 8 : str_len;
+		str_len -= msg.dlc;
+		memcpy(msg.data, string, msg.dlc);
+		string += msg.dlc;
+		can_send(can_dev, &msg, 10, tx_irq_callback);
+	}
+}
+
+void tx_thread(void *can_dev_param, void *unused2, void *unused3)
+{
+	u8_t toggle = SET_LED;
+	u16_t button_press_cnt = 0;
+	struct can_msg msg;
+	struct can_msg msg_button_cnt;
+	struct device *can_dev = can_dev_param;
+
+	msg.std_id = LED_MSG_ID;
+	msg.id_type = CAN_STANDARD_IDENTIFIER;
+	msg.dlc = 1;
+	msg.rtr = CAN_DATAFRAME;
+	msg.data[0] = 0;
+
+	msg_button_cnt.std_id = BUTTON_MSG_ID;
+	msg_button_cnt.id_type = CAN_STANDARD_IDENTIFIER;
+	msg_button_cnt.dlc = 2;
+	msg_button_cnt.rtr = CAN_DATAFRAME;
+	msg_button_cnt.data[0] = 0;
+	msg_button_cnt.data[1] = 0;
+
+	printk("TX thread is running.\n");
+	while (1) {
+		k_sem_take(&tx_sem, K_FOREVER);
+		button_press_cnt++;
+		toggle = (toggle == SET_LED) ? RESET_LED : SET_LED;
+		printk("Button pressed! Send message %u\n", toggle);
+		msg.data[0] = toggle;
+		msg_button_cnt.data[0] = button_press_cnt & 0xFF;
+		msg_button_cnt.data[1] = (button_press_cnt >> 8) & 0xFF;
+		can_send(can_dev, &msg, 10, tx_irq_callback);
+		can_send(can_dev, &msg_button_cnt, 10, NULL);
+		if (toggle == SET_LED) {
+			send_string("String sent over CAN\n", can_dev);
+		}
+	}
+}
+
+void rx_str_thread(void *msgq, void *can_dev_param, void *unused)
+{
+	struct can_msg msg;
+	const struct can_filter filter = {
+		.id_type = CAN_EXTENDED_IDENTIFIER,
+		.rtr = CAN_DATAFRAME,
+		.ext_id = STR_MSG_ID,
+		.rtr_mask = 1,
+		.ext_id_mask = CAN_EXT_ID_MASK
+	};
+	struct device *can_dev = can_dev_param;
+
+	can_attach_msgq(can_dev, msgq, &filter);
+
+	while (1) {
+		k_msgq_get((struct k_msgq *)msgq, &msg, K_FOREVER);
+		for (int i = 0; i < msg.dlc; i++)
+			printk("%c", msg.data[i]);
+	}
+}
+
+void led_thread(void *msgq, void *can_dev_param, void *gpio_dev_param)
+{
+	const struct can_filter filter = {
+		.id_type = CAN_STANDARD_IDENTIFIER,
+		.rtr = CAN_DATAFRAME,
+		.std_id = LED_MSG_ID,
+		.rtr_mask = 1,
+		.std_id_mask = CAN_STD_ID_MASK
+	};
+	struct device *can_dev = can_dev_param;
+	struct device *gpio_dev = gpio_dev_param;
+	struct can_msg msg;
+	int ret;
+	int filter_id;
+
+	ret = gpio_pin_configure(gpio_dev, CONFIG_PIN_LED_1, GPIO_DIR_OUT);
+	gpio_pin_write(gpio_dev, CONFIG_PIN_LED_1, 0);
+
+	if (ret) {
+		printk("ERROR configure pins\n");
+		return;
+	}
+
+	filter_id = can_attach_msgq(can_dev, msgq, &filter);
+	printk("filter id: %d\n", filter_id);
+
+	while (1) {
+		k_msgq_get((struct k_msgq *)msgq, &msg, K_FOREVER);
+
+		if (msg.dlc != 1) {
+			continue;
+		}
+
+		switch (msg.data[0]) {
+		case SET_LED:
+			gpio_pin_write(gpio_dev, CONFIG_PIN_LED_1, 1);
+
+			break;
+		case RESET_LED:
+			gpio_pin_write(gpio_dev, CONFIG_PIN_LED_1, 0);
+			break;
+		}
+	}
+}
+
+void rx_button_isr(struct can_msg *msg)
+{
+	u16_t cnt = msg->data[0] | (msg->data[1] << 8);
+
+	printk("Button pressed %d times\n", cnt);
+}
+
+void main(void)
+{
+	const struct can_filter filter = {
+		.id_type = CAN_STANDARD_IDENTIFIER,
+		.rtr = CAN_DATAFRAME,
+		.std_id = BUTTON_MSG_ID,
+		.rtr_mask = 1,
+		.std_id_mask = CAN_STD_ID_MASK
+	};
+	struct device *can_dev, *led_gpio_dev, *button_gpio_dev;
+	int ret;
+
+	can_dev = device_get_binding(CONFIG_CAN_DEV);
+	if (!can_dev) {
+		printk("CAN: Device driver not found.\n");
+		return;
+	}
+
+#ifdef CONFIG_LOOPBACK_MODE
+	can_configure(can_dev, CAN_LOOPBACK_MODE, 250000);
+#endif
+
+	led_gpio_dev = device_get_binding(CONFIG_GPIO_LED_DEV);
+	if (!led_gpio_dev) {
+		printk("LED: Device driver not found.\n");
+		return;
+	}
+
+	k_sem_init(&tx_sem, 0, INT_MAX);
+
+	button_gpio_dev = device_get_binding(CONFIG_GPIO_BUTTON_DEV);
+	if (!button_gpio_dev) {
+		printk("Button: Device driver not found.\n");
+		return;
+	}
+
+	ret = gpio_pin_configure(button_gpio_dev, CONFIG_PIN_USER_BUTTON,
+				    (GPIO_DIR_IN | GPIO_INT | GPIO_INT_EDGE |
+				     GPIO_INT_ACTIVE_HIGH | GPIO_INT_DEBOUNCE));
+	if (ret) {
+		printk("Error configuring  button pin\n");
+	}
+
+	gpio_init_callback(&gpio_cb, button_callback,
+			   BIT(CONFIG_PIN_USER_BUTTON));
+
+	ret = gpio_add_callback(button_gpio_dev, &gpio_cb);
+	if (ret) {
+		printk("Cannot setup callback!\n");
+	}
+
+	ret = gpio_pin_enable_callback(button_gpio_dev, CONFIG_PIN_USER_BUTTON);
+	if (ret) {
+		printk("Error enabling callback!\n");
+	}
+
+	can_attach_isr(can_dev, rx_button_isr, &filter);
+
+	k_tid_t tx_tid = k_thread_create(&tx_thread_data, tx_thread_stack,
+					 K_THREAD_STACK_SIZEOF(tx_thread_stack),
+					 tx_thread,
+					 can_dev, NULL, NULL,
+					 TX_THREAD_PRIORITY, 0, K_NO_WAIT);
+	if (!tx_tid) {
+		printk("ERROR spawning tx_thread\n");
+	}
+
+	k_tid_t led_tid = k_thread_create(&led_thread_data, led_thread_stack,
+					  K_THREAD_STACK_SIZEOF(led_thread_stack),
+					  led_thread,
+					  &led_msgq, can_dev, led_gpio_dev,
+					  TX_THREAD_PRIORITY, 0, K_NO_WAIT);
+	if (!led_tid) {
+		printk("ERROR spawning led_thread\n");
+	}
+
+	k_tid_t str_tid = k_thread_create(&rx_str_thread_data,
+					  rx_str_thread_stack,
+					  K_THREAD_STACK_SIZEOF(rx_str_thread_stack),
+					  rx_str_thread,
+					  &str_msgq, can_dev, NULL,
+					  TX_THREAD_PRIORITY, 0, K_NO_WAIT);
+	if (!str_tid) {
+		printk("ERROR spawning str_thread\n");
+	}
+
+	printk("Finished init. waiting for Interrupts\n");
+}

samples/samples.rst

@@ -20,6 +20,7 @@ Samples and Demos
    drivers/drivers.rst
    application_development/*
    display/*
+   can/README.rst
 
 
 To add a new sample document, please use the template available under