Volodymyr.savchenko

06-TimeManagement/Makefile

@@ -0,0 +1,14 @@
+obj-m+=my_time.o
+
+all:
+	make -C /lib/modules/$(shell uname -r)/build/ M=$(PWD) modules
+
+clean:
+	make -C /lib/modules/$(shell uname -r)/build/ M=$(PWD) modules
+
+# obj-m+=mymodule.o
+
+# all:
+# 	make -C $(BUILD_KERNEL) M=$(PWD) modules
+# clean:	
+# 	make -C $(BUILD_KERNEL) M=$(PWD) clean

06-TimeManagement/dmesg_timer.log

@@ -0,0 +1,86 @@
+>>>>>>>>>>>>> cmd
+~/projects/training/linux/task_06$ insmod my_time.ko
+~/projects/training/linux/task_06$ cat /sys/class/myTime/info 
+Now: 2018-11-18 17-08-47
+Time in sec from previous read:: 27
+Last read time (absolute): 2018-11-18 17-08-20
+~/projects/training/linux/task_06$ cat /sys/class/myTime/info 
+Now: 2018-11-18 17-08-53
+Time in sec from previous read:: 5
+Last read time (absolute): 2018-11-18 17-08-48
+~/projects/training/linux/task_06$ echo 1 > /sys/class/myTime/set 
+~/projects/training/linux/task_06$ echo 1 > /sys/class/myTime/info
+bash: echo: помилка запису: Помилка введення-виведення
+~/projects/training/linux/task_06$ echo 1.25 > /sys/class/myTime/set 
+~/projects/training/linux/task_06$ dmesg
+~/projects/training/linux/task_06$ echo 6.25 > /sys/class/myTime/set 
+~/projects/training/linux/task_06$ echo "asdfg" > /sys/class/myTime/set 
+~/projects/training/linux/task_06$ echo 2000 > /sys/class/myTime/set 
+~/projects/training/linux/task_06$ rmmod my_time 
+~/projects/training/linux/task_06$ dmesg > dmesg_timer.log 
+>>>>>>>>>>>> dmesg
+[16049.777041] my_time: loaded
+[16055.021400] my_time: call my_timer_callback, delay: 5000 [ms]
+[16060.136940] my_time: call my_timer_callback, delay: 5000 [ms]
+[16065.252663] my_time: call my_timer_callback, delay: 5000 [ms]
+[16070.368201] my_time: call my_timer_callback, delay: 5000 [ms]
+[16075.483406] my_time: call my_timer_callback, delay: 5000 [ms]
+[16077.372713] my_time: call my_show
+[16077.372716] my_time: call my_show 
+[16080.598918] my_time: call my_timer_callback, delay: 5000 [ms]
+[16083.145935] my_time: call my_show
+[16083.145938] my_time: call my_show 
+[16085.715049] my_time: call my_timer_callback, delay: 5000 [ms]
+[16090.839449] my_time: call my_timer_callback, delay: 5000 [ms]
+[16095.945524] my_time: call my_timer_callback, delay: 5000 [ms]
+[16101.061111] my_time: call my_timer_callback, delay: 5000 [ms]
+[16106.176742] my_time: call my_timer_callback, delay: 5000 [ms]
+[16111.292365] my_time: call my_timer_callback, delay: 5000 [ms]
+[16116.407726] my_time: call my_timer_callback, delay: 5000 [ms]
+[16121.523508] my_time: call my_timer_callback, delay: 5000 [ms]
+[16126.639240] my_time: call my_timer_callback, delay: 5000 [ms]
+[16131.754892] my_time: call my_timer_callback, delay: 5000 [ms]
+[16134.670267] my_time: call my_store
+[16134.670271] my_time: call my_store, invalid value of the delay: 1
+[16134.670273] my_time: call my_store, using default: 5000
+[16139.683559] my_time: call my_timer_callback, delay: 5000 [ms]
+[16144.799318] my_time: call my_timer_callback, delay: 5000 [ms]
+[16149.914480] my_time: call my_timer_callback, delay: 5000 [ms]
+[16155.030519] my_time: call my_timer_callback, delay: 5000 [ms]
+[16160.146208] my_time: call my_timer_callback, delay: 5000 [ms]
+[16165.261137] my_time: call my_timer_callback, delay: 5000 [ms]
+[16170.376691] my_time: call my_timer_callback, delay: 5000 [ms]
+[16170.747261] my_time: call my_store
+[16170.747265] my_time: call my_store, invalid value of the delay: 1
+[16170.747267] my_time: call my_store, using default: 5000
+[16175.748901] my_time: call my_timer_callback, delay: 5000 [ms]
+[16180.863551] my_time: call my_timer_callback, delay: 5000 [ms]
+[16185.979096] my_time: call my_timer_callback, delay: 5000 [ms]
+[16187.781406] my_time: call my_store
+[16187.781410] my_time: call my_store, invalid value of the delay: 6
+[16187.781412] my_time: call my_store, using default: 5000
+[16192.885044] my_time: call my_timer_callback, delay: 5000 [ms]
+[16198.001295] my_time: call my_timer_callback, delay: 5000 [ms]
+[16203.116160] my_time: call my_timer_callback, delay: 5000 [ms]
+[16206.525201] my_time: call my_store
+[16206.525204] my_time: call my_store, can't read delay value!
+[16211.557390] my_time: call my_timer_callback, delay: 5000 [ms]
+[16216.672922] my_time: call my_timer_callback, delay: 5000 [ms]
+[16221.788650] my_time: call my_timer_callback, delay: 5000 [ms]
+[16226.903444] my_time: call my_timer_callback, delay: 5000 [ms]
+[16232.019826] my_time: call my_timer_callback, delay: 5000 [ms]
+[16237.135404] my_time: call my_timer_callback, delay: 5000 [ms]
+[16242.250068] my_time: call my_timer_callback, delay: 5000 [ms]
+[16247.365837] my_time: call my_timer_callback, delay: 5000 [ms]
+[16252.481467] my_time: call my_timer_callback, delay: 5000 [ms]
+[16257.597082] my_time: call my_timer_callback, delay: 5000 [ms]
+[16262.712189] my_time: call my_timer_callback, delay: 5000 [ms]
+[16265.054779] my_time: call my_store
+[16267.060387] my_time: call my_timer_callback, delay: 2000 [ms]
+[16269.075265] my_time: call my_timer_callback, delay: 2000 [ms]
+[16271.089700] my_time: call my_timer_callback, delay: 2000 [ms]
+[16273.104114] my_time: call my_timer_callback, delay: 2000 [ms]
+[16275.117559] my_time: call my_timer_callback, delay: 2000 [ms]
+[16277.131978] my_time: call my_timer_callback, delay: 2000 [ms]
+[16279.145903] my_time: call my_timer_callback, delay: 2000 [ms]
+[16280.351788] my_time: removed

06-TimeManagement/my_time.c

@@ -0,0 +1,170 @@
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/ctype.h>
+#include <linux/string.h>
+#include <linux/jiffies.h>
+#include <linux/time.h>
+#include <linux/timer.h>
+
+#define DEFAULT_DELAY_IN_MS 5000
+#define MIN_DELAY_IN_MS 100
+
+static unsigned long jiffies_stamp;
+static unsigned long jiffies_now;
+static unsigned long delta_in_ms;
+static struct timespec epoch_now;
+static struct timer_list my_timer;
+
+
+static void mod_my_timer(void)
+{
+	mod_timer(&my_timer, jiffies + msecs_to_jiffies(delta_in_ms));
+}
+
+static void my_timer_callback(unsigned long data)
+{
+	pr_info("my_time: call %s, delay: %lu [ms]\n", __func__, delta_in_ms);
+	mod_my_timer();
+}
+
+static ssize_t my_show(struct class *class, struct class_attribute *attr,
+						char *buf)
+{
+	struct tm last_read;
+
+	pr_info("my_time: call %s", __func__);
+
+	jiffies_now = jiffies;
+
+	if (time_before(jiffies_stamp, jiffies_now)) {
+		getnstimeofday(&epoch_now);
+		time_to_tm(epoch_now.tv_sec, 0,  &last_read);
+		pr_info("my_time: call %s ", __func__);
+		sprintf(buf, "Now: %04ld-%02d-%02d %02d-%02d-%02d\n",
+			1900 + last_read.tm_year, 1 + last_read.tm_mon, last_read.tm_mday,
+			last_read.tm_hour, last_read.tm_min, last_read.tm_sec);
+		sprintf(buf + strlen(buf), "Time in sec from previous read:: %lu\n",
+				(jiffies_now - jiffies_stamp) / HZ);
+		time_to_tm(epoch_now.tv_sec - (jiffies_now - jiffies_stamp) / HZ, 0,
+			&last_read);
+		sprintf(buf + strlen(buf),
+			"Last read time (absolute): %04ld-%02d-%02d %02d-%02d-%02d\n",
+			1900 + last_read.tm_year, 1 + last_read.tm_mon, last_read.tm_mday,
+			last_read.tm_hour, last_read.tm_min, last_read.tm_sec);
+		jiffies_stamp = jiffies_now;
+	} else {
+		sprintf(buf, "Overflow detected. Re-init now.");
+		jiffies_stamp = jiffies_now;
+	}
+	return strlen(buf);
+}
+
+static ssize_t my_store(struct class *class, struct class_attribute *attr,
+						const char *buf, size_t count)
+{
+	int ret_value;
+
+	pr_info("my_time: call %s", __func__);
+	ret_value = sscanf(buf, "%lu", &delta_in_ms);
+
+	if (ret_value != 1) {
+		pr_info("my_time: call %s, can't read delay value!\n", __func__);
+	}
+
+	if (delta_in_ms < MIN_DELAY_IN_MS) {
+		pr_info("my_time: call %s, invalid value of the delay: %lu\n",
+			__func__, delta_in_ms);
+		delta_in_ms = DEFAULT_DELAY_IN_MS;
+		pr_info("my_time: call %s, using default: %lu\n", __func__,
+			delta_in_ms);
+	}
+
+	mod_my_timer();
+	return count;
+}
+
+
+static ssize_t my_info(struct class *class, struct class_attribute *attr,
+						char *buf)
+{
+
+	pr_info("my_time: call %s", __func__);
+	sprintf(buf, "Time delay now is: %ld [ms]", delta_in_ms);
+	return strlen(buf);
+}
+
+
+struct class_attribute class_attr_tm = {
+	.attr = { .name = "info", .mode = 0666 },
+	.show	= my_show,
+};
+
+
+struct class_attribute class_attr_set = {
+	.attr = { .name = "set", .mode = 0666 },
+	.show	= my_info,
+	.store  = my_store
+};
+
+
+static struct class *attr_class;
+
+
+static int my_init(void)
+{
+	int ret;
+
+	jiffies_stamp = jiffies;
+
+	attr_class = class_create(THIS_MODULE, "myTime");
+
+	if (attr_class == NULL) {
+		pr_err("my_time: error creating sysfs class\n");
+		return -ENOMEM;
+	}
+
+	ret = class_create_file(attr_class, &class_attr_tm);
+	if (ret) {
+		pr_err("my_time: error creating sysfs class attribute\n");
+		class_destroy(attr_class);
+		return ret;
+	}
+
+
+	ret = class_create_file(attr_class, &class_attr_set);
+	if (ret) {
+		pr_err("my_time: error creating sysfs class attribute\n");
+		class_destroy(attr_class);
+		return ret;
+	}
+	delta_in_ms = DEFAULT_DELAY_IN_MS;
+	setup_timer(&my_timer, my_timer_callback, 0);
+	mod_my_timer();
+
+	pr_info("my_time: loaded\n");
+	return 0;
+}
+
+static void my_exit(void)
+{
+	del_timer(&my_timer);
+	class_remove_file(attr_class, &class_attr_tm);
+	class_remove_file(attr_class, &class_attr_set);
+
+	class_destroy(attr_class);
+
+	pr_info("my_time: removed\n");
+}
+
+module_init(my_init);
+module_exit(my_exit);
+
+MODULE_AUTHOR("Volodymyr Savchenko <[email protected]>");
+MODULE_DESCRIPTION("Linux kernel time example`");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("0.1");
+
+