sepfy

PWD := $(shell pwd) 
KVERSION := $(shell uname -r)
KERNEL_DIR = /usr/src/linux-headers-$(KVERSION)/

MODULE_NAME = mydev
obj-m := $(MODULE_NAME).o

all:
	make -C $(KERNEL_DIR) M=$(PWD) modules
clean:

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#include <linux/module.h>
#include <linux/device.h>
#include <linux/err.h>

int value = 0;

static ssize_t attr_store(struct device *dev,
		struct device_attribute *attr,
		const char *buf, size_t count)
{

sepfy

# Check gpio usage
mount -t debugfs debugfs /sys/kernel/debug
cat /sys/kernel/debug/gpio

sepfy

...

//char* reportedProperties = serializeToJson(&car);
char reportedProperties[512];
sprintf(reportedProperties, "{\"temperature\": 27.6, \"humidity\": 67.3}");

if (reportedProperties != NULL)
{
        (void)IoTHubDeviceClient_LL_SendReportedState(iotHubClientHandle, (const unsigned char*)reportedProperties, strlen(reportedProperties), reportedStateCallback, NULL);

sepfy

  int val = 0;
	int temp, humi;

	u8 bytes[6] = {0};
	const u8 cmd[6] = {0};
	u32 s;

	printk("[%s][%d]\n", __func__, __LINE__);
	s = i2c_smbus_write_i2c_block_data(i2c_client, 0x24, 1, cmd);
	if(s < 0) {

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echo "scale=2; -45 + 175*$(cat /sys/class/sensor/sht31/temperature)/65535" | bc
echo "scale=2; 100*$(cat /sys/class/sensor/sht31/humidity)/65535" | bc

sepfy

static ssize_t attr_store(struct device *dev,
		struct device_attribute *attr,
		const char *buf, size_t count)
{

	printk("[%s][%d]\n", __func__, __LINE__);
	buzzer_trigger = simple_strtoul(buf, NULL, 10);
	gpio_set_value(BUZZER, buzzer_trigger);
	return count;
}

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#define BUZZER 23
#define BUTTON 21

static short int button_irq = 0;
static unsigned long flags = 0;

int buzzer_trigger = 0;
u32 trigger_jiffies;

static irqreturn_t button_isr(int irq, void *data)

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static struct miscdevice my_miscdev = {
	.minor      = 11,
	.name       = "misc_dev",
	.fops       = &mydev_fops,
};

static int __init init_modules(void)
{
	int ret;
	ret = misc_register(&my_miscdev);

sepfy

static ssize_t
mydev_read(struct file *filp, char __user *buf, size_t count, loff_t *pos)
{
	char tmp[] = "Kernel says hello";
	printk("[%s][%d]\n", __func__, __LINE__);
	copy_to_user(buf, tmp, sizeof(tmp));
	*pos = 0;
	return 0;
}