lst.c

#include "./keyboard.h"

// pointer to the first elem in linked list
t_key	*first = NULL;

void	add_tail(unsigned char scancode)
{
	t_key	*idx = first;
	t_key	*new_node = NULL;

	// create new node
	new_node = (t_key *)kcalloc(1, sizeof(t_key), GFP_KERNEL);
	if (new_node == NULL) {
		pr_info("Malloc failure\n");
 		return ;
	}

	// init all field
	new_node->key = scancode & KBD_SCANCODE_MASK;
	new_node->state = scancode & KBD_STATUS_MASK ? 0 : 1;
	strcpy(new_node->name, key_name[new_node->key]);
	getnstimeofday(&(new_node->time));
	new_node->next = NULL;

	// chain list
	if (idx == NULL) {
		first = new_node;
	} else {
		while (idx->next != NULL) {
			idx = idx->next;
		}
		idx->next = new_node;
	}
}

void	free_lst(void)
{
	t_key	*idx = first;
	t_key	*tmp = idx;

	while (idx != NULL) {
		tmp = idx;
		idx = idx->next;
		kfree(tmp);
		tmp = NULL;
	}
}