Output working now

char_dev.c

@@ -0,0 +1,74 @@
+
+static char device_buffer[1];
+static int major;
+static uint8_t buff_empty=1;
+static uint8_t buff_start;
+static uint8_t buff_end;
+
+
+static uint8_t buffer[BUFFER_SIZE];
+
+static uint8_t readBuffer(void){
+    uint8_t ret;    
+    if(buff_empty){
+        return 0;
+    }
+    ret=buffer[buff_end];
+    buff_end++;
+    if(buff_end==BUFFER_SIZE){
+        buff_end=0;
+    }
+    if(buff_end==buff_start){
+        buff_empty=1;
+    }
+    return ret;
+}
+
+static uint8_t writeToBuffer(uint8_t data){
+    if(buff_start==buff_end && !buff_empty){
+        /*overrun*/
+		printk("<1>%s: Buffer overrun!\n",MOD_NAME);
+		return 1;
+    }
+    buffer[buff_start]=data;
+    buff_start++;
+    if(buff_start==BUFFER_SIZE){
+        buff_start=0;
+    }
+    buff_empty=0;
+	return 0;
+}
+
+static ssize_t device_read(struct file *filp, char __user *buffer, size_t length, loff_t *offset){
+	uint8_t val;
+	if(!buff_empty){
+		val = readBuffer();
+		DEBUG_OUT("<1>%s: device_read invoked writing: mem[%x]=%02x\n",MOD_NAME,buffer,val);
+		if( copy_to_user(buffer,&val,1)<0 ){
+			printk("<1>%s: Device read error!\n",MOD_NAME);
+			return 0;
+		}
+		return 1;
+	}
+	return 0;
+}
+
+static ssize_t device_write(struct file *filp, const char __user *buff, size_t len, loff_t *off){
+	int ret;	
+	DEBUG_OUT("<1>%s: device_write invoked\n",MOD_NAME);
+	if(len!=1){
+		return -EINVAL;
+	}
+	ret = copy_from_user(device_buffer, buff, len);
+	if( ret<0 ){
+		printk("<1>%s: Device write error!\n",MOD_NAME);
+		return 0;
+	}
+	return len;
+}
+
+struct file_operations fops = {
+  read: device_read,
+  write: device_write,
+};
+

common.h

@@ -0,0 +1,8 @@
+
+#ifndef _COMMON_H
+#define _COMMON_H
+
+#define MOD_NAME "usb_gpio"
+enum pin_commands {CMD_IN, CMD_OUTH, CMD_OUTL, CMD_H, CMD_L, CMD_READ};
+
+#endif //_COMMON_H

ftdi_daemon.c

@@ -6,6 +6,8 @@ uint8_t USB_GPIO_DDR;
 uint8_t USB_GPIO_PORT;
 uint8_t USB_GPIO_PIN;
 
+FILE* fd;
+
 volatile uint8_t main_loop=1;
 
 static int vendor=0x0403, device=0x6001;
@@ -165,7 +167,7 @@ static int cmd_fsm(char c){
 				case CMD_READ:
 					ret = get_value((unsigned)pin);
 					DEBUG_OUT("Value of %d is %d\n", pin,ret);
-					fputc((char)ret,stdout);
+					fputc((char)ret,fd);
 					return 0;
 			}
 	}
@@ -174,14 +176,16 @@ static int cmd_fsm(char c){
 
 int main(void){
 	int ret=ftdi_chip_init();
+	fd=fopen("/dev/usb_gpio","rw");
 	if(ret!=0){
 		return ret;
 	}
 
 	for(;main_loop;){
-		//kernel will write commands to the stdin
-		ret = fgetc(stdin);
+		//kernel will write commands to the device file
+		ret = fgetc(fd);
 		if( ret!=EOF ){
+			DEBUG_OUT("read %02x\n",ret);
 			cmd_fsm(ret);
 		}else{
 			//main_loop=0;

ftdi_daemon.h

@@ -6,6 +6,7 @@
 #include <stdio.h>
 #include <stdint.h>
 #include <errno.h>
+#include <fcntl.h> 
 
 #include "common.h"
 

gpio_callbacks.c

@@ -1,20 +1,49 @@
 
 static int get_value(struct gpio_chip *gc, unsigned offset){
+	int ret;
+
 	DEBUG_OUT("<1>%s: GET_VALUE of pin%d ",MOD_NAME,offset);
-	return 0;
+
+	ret=writeToBuffer(offset);
+	ret|=writeToBuffer(CMD_READ);
+
+	return -ret;
 }
 
 static void set_value(struct gpio_chip *chip, unsigned offset, int value){
 	DEBUG_OUT("<1>%s: SET_VALUE of pin%d to %d",MOD_NAME,offset,value);
+
+	writeToBuffer(offset);
+	if(value){
+		writeToBuffer(CMD_H);
+	}else{
+		writeToBuffer(CMD_L);
+	}
 }
 
 static int set_in(struct gpio_chip *chip, unsigned offset){
+	int ret=0;
+
 	DEBUG_OUT("<1>%s: SET_INPUT of pin%d ",MOD_NAME,offset);
-	return 0;
+
+	ret=writeToBuffer(offset);
+	ret|=writeToBuffer(CMD_IN);
+
+	return -ret;
 }
 
 static int set_out(struct gpio_chip *chip, unsigned offset, int value){
+	int ret;
+
 	DEBUG_OUT("<1>%s: SET_OUTPUT of pin%d to %d",MOD_NAME,offset,value);
-	return 0;
+
+	ret=writeToBuffer(offset);
+	if(value){
+		ret|=writeToBuffer(CMD_OUTH);
+	}else{
+		ret|=writeToBuffer(CMD_OUTL);
+	}
+
+	return -ret;
 }
 

usb_gpio.c

@@ -3,12 +3,14 @@
 static struct gpio_chip ft232_chip;
 static struct subprocess_info *sub_info;
 
+#include "char_dev.c"
 #include "gpio_callbacks.c"
 
 static void usb_gpio_exit(void) {
 	if( gpiochip_remove(&ft232_chip)<0 ){
 		printk("<1>%s: Couldn't free GPIO-pins!\n",MOD_NAME);
 	}
+	unregister_chrdev(major, MOD_NAME);
 	printk("<1>%s: Bye!\n",MOD_NAME);
 }
 
@@ -23,6 +25,14 @@ static int usb_gpio_init(void) {
 
 	printk("<1>%s: Loading... \n",MOD_NAME);
 	
+	major = register_chrdev(0, MOD_NAME, &fops);
+	if(major<0){
+		printk("<1>%s: Can't register character device!\n",MOD_NAME);
+	}
+	printk("<1>%s: Assigned device major #%d minor #0!\n",MOD_NAME,major);
+	printk("<1>%s: Create device file with: \"mknod /dev/usb_gpio c %d 0\"\n",MOD_NAME,major);
+
+	//GPIO registration
 	ft232_chip.label = MOD_NAME;
 
 	//Callback functions
@@ -44,15 +54,18 @@ static int usb_gpio_init(void) {
 	if (ret){
 		printk("<1>%s: Can't register chip!\n",MOD_NAME);
 	}
-	
-	//Call the user space handler
-	sub_info = call_usermodehelper_setup( argv[0], argv, envp, GFP_ATOMIC );
-  	if (sub_info == NULL){
-		return -ENOMEM;
-	}
+	return ret;
+    //Call the user space handler
+    /*sub_info = call_usermodehelper_setup( argv[0], argv, envp, GFP_ATOMIC );
+    if (sub_info == NULL){
+	    return -ENOMEM;
+    }
 
-	// the helper will run in the background until the module decides to kill it
-	return call_usermodehelper_exec( sub_info, UMH_NO_WAIT );
+    // the helper will run in the background until the module decides to kill it
+    ret=call_usermodehelper_exec( sub_info, UMH_NO_WAIT );
+	if(ret<0){
+		printk("<1>%s: Couldn't run userspace helper process (%s)!\n",MOD_NAME,);
+	}*/
 }
 
 module_init(usb_gpio_init);

usb_gpio.h

@@ -11,10 +11,14 @@
 #include <linux/kmod.h>
 #include <linux/msg.h>
 
+#include <linux/fs.h>
+#include <asm/uaccess.h>
+
 #include "usb_gpio_util.h"
 #include "common.h"
 
 #define NUM_OF_GPIO 8
+#define BUFFER_SIZE 1024
 
 #ifndef CONFIG_GENERIC_GPIO
 #error This module needs generic gpio support (CONFIG_GENERIC_GPIO)