Initial commit

app/app.c

+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/sysmacros.h>
+
+#define LED_MAJOR_NUMBER	504
+#define LED_MINOR_NUMBER	100
+#define LED_DEV_PATH_NAME	"/dev/uart_ioctl"
+
+#define IOCTL_MAGIC_NUMBER 'l'
+#define IOCTL_CMD_DIRECTION		_IOWR(IOCTL_MAGIC_NUMBER, 0, int)
+#define IOCTL_CMD_RECEIVE		_IOWR(IOCTL_MAGIC_NUMBER, 1, int)
+#define IOCTL_CMD_TRANSMIT		_IOWR(IOCTL_MAGIC_NUMBER, 2, int)
+
+int main(void)
+{
+	// dev_t led_ioctl;
+	int fd;
+	int txrx;
+	char buf[1024];
+		
+	// led_ioctl = makedev(LED_MAJOR_NUMBER, LED_MINOR_NUMBER);
+	// mknod(LED_DEV_PATH_NAME, S_IFCHR|0666, led_dev);
+	
+	fd = open(LED_DEV_PATH_NAME, O_RDWR);
+	
+	if(fd < 0){
+		printf("fail to open led\n");
+		return -1;
+	}
+	
+	printf("rx: 0, tx: 1. enter parameter: ");
+	scanf("%d", &txrx);
+	ioctl(fd, IOCTL_CMD_DIRECTION, &txrx);
+	
+	if(txrx == 0){
+		printf("now RPi keep reading..\n");
+		while(1){
+			ioctl(fd, IOCTL_CMD_RECEIVE, &buf);
+			printf("%1023s",buf);
+		}
+	}else if(txrx == 1){
+		printf("now RPi keep writing..\n");
+		while(1){
+			printf("Input string: ");
+			scanf("%1023s",buf);
+			ioctl(fd, IOCTL_CMD_TRANSMIT, &buf);
+		}
+	}else{
+		printf("invalid parameter. program shutdown\n");
+	}
+	
+	close(fd);
+	
+	return 0;
+}

dev/.dev.ko.cmd

+cmd_/home/pi/Workspace/project_6/dev/dev.ko := ld -r  -EL -T ./scripts/module-common.lds -T ./arch/arm/kernel/module.lds  --build-id  -o /home/pi/Workspace/project_6/dev/dev.ko /home/pi/Workspace/project_6/dev/dev.o /home/pi/Workspace/project_6/dev/dev.mod.o ;  true

dev/.tmp_versions/dev.mod

+/home/pi/Workspace/project_6/dev/dev.ko
+/home/pi/Workspace/project_6/dev/dev.o
+

dev/Makefile

+KERNEL_DIR = /lib/modules/4.19.66-v7+/build
+
+obj-m := dev.o
+
+PWD := $(shell pwd)
+
+all :
+	make -C $(KERNEL_DIR) M=$(PWD) modules
+	
+clean:
+	make -C $(KERNEL_DIR) M=$(PWD) clean

dev/dev.c

+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+
+#include <asm/mach/map.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+
+#define UART_MAJOR_NUMBER	504
+#define UART_DEV_NAME		"uart_ioctl"
+
+#define GPIO_BASE_ADDR 0x3F200000
+#define GPFSEL1 0x04
+#define USRT_BASE_ADDR 0x3F201000
+#define UART_DR 0x00
+#define UART_FR 0x18
+#define UART_CR	0x30
+#define UART_LCRH 0X2C
+
+#define IOCTL_MAGIC_NUMBER 'l'
+#define IOCTL_CMD_DIRECTION		_IOWR(IOCTL_MAGIC_NUMBER, 0, int)
+#define IOCTL_CMD_RECEIVE			_IOWR(IOCTL_MAGIC_NUMBER, 1, int)
+#define IOCTL_CMD_TRANSMIT			_IOWR(IOCTL_MAGIC_NUMBER, 2, int)
+
+static void __iomem *gpio_base;
+static void __iomem *usrt_base;
+volatile unsigned int *gpsel1;
+volatile unsigned int *uart_dr;
+volatile unsigned int *uart_fr;
+volatile unsigned int *uart_cr;
+volatile unsigned int *uart_lcrh;
+
+int uart_open(struct inode *inode, struct file *filp){
+	printk(KERN_ALERT "UART driver open!!\n");
+	
+	gpio_base = ioremap(GPIO_BASE_ADDR, 0x60);
+	usrt_base = ioremap(USRT_BASE_ADDR, 0x60);
+	gpsel1 = (volatile unsigned int *)(gpio_base + GPFSEL1);
+	uart_dr = (volatile unsigned int *)(usrt_base + UART_DR);
+	uart_fr = (volatile unsigned int *)(usrt_base + UART_FR);
+	uart_cr = (volatile unsigned int *)(usrt_base + UART_CR); // 185PAGE
+	uart_lcrh = (volatile unsigned int *)(usrt_base + UART_LCRH);
+	
+	
+	
+	return 0;
+}
+
+int uart_release(struct inode *inode, struct file *filp){
+	printk(KERN_ALERT "UART driver closed!!\n");
+	iounmap((void *)gpio_base);
+	return 0;
+}
+
+long uart_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+	unsigned int txff, rxfe;
+	int kbuf=-1;
+	int i=0;
+	char cbuf[1024];
+	int writelen = 0;
+	char singlechar = '\0';
+	
+	switch (cmd){
+		case IOCTL_CMD_DIRECTION:
+			copy_from_user(&kbuf,(const void*)arg, 4);
+			*gpsel1 |= (1<<14); // gpio14 takes alt0 TXD0
+			*gpsel1 |= (1<<17); // gpio15 takes alt0 RXD0
+			if(kbuf==0){
+				// input
+				*uart_cr &= ~(1<<0); // disable uart.
+				*uart_lcrh &= ~(1<<4); // FEN <- 0.
+				*uart_cr &= ~(1<<8); // TXE <- 0
+				*uart_cr |= (1<<9); // RXE <- 1
+				*uart_lcrh |= (1<<4); // FEN <- 1.
+				*uart_cr |= (1<<0); // enable uart.
+			} else if(kbuf==1){
+				// output
+				*uart_cr &= ~(1<<0); // disable uart.
+				*uart_lcrh &= ~(1<<4); // FEN <- 0.
+				*uart_cr &= ~(1<<9); // RXE <- 0
+				*uart_cr |= (1<<8); // TXE <- 1
+				*uart_lcrh |= (1<<4); // FEN <- 1.
+				*uart_cr |= (1<<0); // enable uart.
+			} else{
+				// error.
+				printk(KERN_ALERT "ERR in DIRECTION: invalid operand\n");
+			}
+			break;
+		
+		case IOCTL_CMD_RECEIVE:
+			printk(KERN_ALERT "receive called\n");
+			/*
+			rxfe = 0;
+			while(!rxfe){
+				rxfe = (*uart_fr>>4); // read RXFE
+			} // now rx is not empty
+			*/
+			i=0;
+			//while(!rxfe){
+				cbuf[i] = (char) (*uart_dr); // read DATA
+				i++;
+				//if(i>1022) break;
+				//rxfe = (*uart_fr>>4); // read RXFE
+			//}
+			cbuf[i]='\n';
+			copy_to_user((const void*)arg, cbuf, 1024);
+			break;
+			
+		case IOCTL_CMD_TRANSMIT:
+			printk(KERN_ALERT "transmit called\n");
+			copy_from_user(&cbuf,(const void*)arg, 1024);
+			writelen = strlen(cbuf);
+			for(i=0; i<writelen; i++){
+				singlechar = cbuf[i];
+				/* 
+				txff = 1;
+				while(txff){
+					txff = (*uart_fr>>5); // read TXFF
+				} // now tx fifo is not full
+				* */
+				*uart_dr |= (int) singlechar; // write DATA
+			}
+			break;
+
+	}
+	return 0;
+}
+
+static struct file_operations uart_fops = {
+	.owner = THIS_MODULE,
+	.open = uart_open,
+	.release = uart_release,
+	.unlocked_ioctl = uart_ioctl
+};
+
+int __init uart_init(void){
+	if(register_chrdev(UART_MAJOR_NUMBER, UART_DEV_NAME, &uart_fops) < 0 )
+		printk(KERN_ALERT "UART driver initialization failed\n");
+	else
+		printk(KERN_ALERT "UART driver initialization successful\n");
+	
+	return 0;
+}
+
+void __exit uart_exit(void){
+	unregister_chrdev(UART_MAJOR_NUMBER, UART_DEV_NAME);
+	printk(KERN_ALERT "UART driver exit done\n");
+}
+
+module_init(uart_init);
+module_exit(uart_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Haeram");
+MODULE_DESCRIPTION("des");

dev/dev.mod.c

+#include <linux/build-salt.h>
+#include <linux/module.h>
+#include <linux/vermagic.h>
+#include <linux/compiler.h>
+
+BUILD_SALT;
+
+MODULE_INFO(vermagic, VERMAGIC_STRING);
+MODULE_INFO(name, KBUILD_MODNAME);
+
+__visible struct module __this_module
+__attribute__((section(".gnu.linkonce.this_module"))) = {
+	.name = KBUILD_MODNAME,
+	.init = init_module,
+#ifdef CONFIG_MODULE_UNLOAD
+	.exit = cleanup_module,
+#endif
+	.arch = MODULE_ARCH_INIT,
+};
+
+#ifdef CONFIG_RETPOLINE
+MODULE_INFO(retpoline, "Y");
+#endif
+
+static const struct modversion_info ____versions[]
+__used
+__attribute__((section("__versions"))) = {
+	{ 0xf230cadf, "module_layout" },
+	{ 0x6bc3fbc0, "__unregister_chrdev" },
+	{ 0xe549e5f5, "__register_chrdev" },
+	{ 0xf4fa543b, "arm_copy_to_user" },
+	{ 0x97255bdf, "strlen" },
+	{ 0xdb7305a1, "__stack_chk_fail" },
+	{ 0x5f754e5a, "memset" },
+	{ 0x28cc25db, "arm_copy_from_user" },
+	{ 0x8f678b07, "__stack_chk_guard" },
+	{ 0xedc03953, "iounmap" },
+	{ 0x2e5810c6, "__aeabi_unwind_cpp_pr1" },
+	{ 0xe97c4103, "ioremap" },
+	{ 0x7c32d0f0, "printk" },
+	{ 0xb1ad28e0, "__gnu_mcount_nc" },
+};
+
+static const char __module_depends[]
+__used
+__attribute__((section(".modinfo"))) =
+"depends=";
+
+
+MODULE_INFO(srcversion, "B707601F40932A4E255B12B");

dev/modules.order

+kernel//home/pi/Workspace/project_6/dev/dev.ko

dev/project_6.sh

+sudo rmmod dev.ko
+sudo rm -rf /dev/uart_ioctl
+
+make clean
+make
+sudo insmod dev.ko
+sudo mknod -m 666 /dev/uart_ioctl c 504 100