simplify USB protocol

3 files changed, 30 insertions, 78 deletions

diff --git a/commandline/i2c-util.c b/commandline/i2c-util.c
index f8aa18d..772aae7 100644
--- a/commandline/i2c-util.c
+++ b/commandline/i2c-util.c
@@ -32,12 +32,14 @@ obtained from http://libusb.sourceforge.net/.
 
 #define PSCMD_ECHO  0
 #define PSCMD_GET   1
-#define PSCMD_ON    2
-#define PSCMD_OFF   3
+#define PSCMD_SET    2
 /* These are the vendor specific SETUP commands implemented by our USB device */
 
-char bit_sda = 6;
-char bit_scl = 7;
+unsigned char bit_sda = 6;
+unsigned char bit_scl = 7;
+
+unsigned char val_sda = 1;
+unsigned char val_scl = 1;
 
 usb_dev_handle *handle = NULL;
 
@@ -179,8 +181,8 @@ unsigned char get_status()
 				     USB_ENDPOINT_IN, PSCMD_GET, 0, 0, (char *)buffer,
 				     sizeof(buffer), 5000);
 
-	if (nBytes < 2) {
-		fprintf(stderr, "ERR: read status: got %d bytes, expected 2\n",
+	if (nBytes < 1) {
+		fprintf(stderr, "ERR: read status: got %d bytes, expected 1\n",
 				nBytes);
 		exit(1);
 	}
@@ -240,9 +242,11 @@ void set_sda(char value)
 	// discarded
 	unsigned char buffer[8];
 
+	val_sda = value;
+
 	usb_control_msg(handle,
 			USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_ENDPOINT_IN,
-			(value ? PSCMD_ON : PSCMD_OFF), 0, bit_sda,
+			PSCMD_SET, 0, (val_sda << bit_sda) | (val_scl << bit_scl),
 			(char *)buffer, sizeof(buffer), 5000);
 }
 
@@ -251,9 +255,11 @@ void set_scl(char value)
 	// discarded
 	unsigned char buffer[8];
 
+	val_scl = value;
+
 	usb_control_msg(handle,
 			USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_ENDPOINT_IN,
-			(value ? PSCMD_ON : PSCMD_OFF), 0, bit_scl,
+			PSCMD_SET, 0, (val_sda << bit_sda) | (val_scl << bit_scl),
 			(char *)buffer, sizeof(buffer), 5000);
 }
 
@@ -333,10 +339,10 @@ void i2c_init()
 {
 	usb_init();
 	if (usbOpenDevice
-	    (&handle, USBDEV_SHARED_VENDOR, "www.obdev.at",
-	     USBDEV_SHARED_PRODUCT, "PowerSwitch") != 0) {
+	    (&handle, USBDEV_SHARED_VENDOR, "finalrewind.org",
+	     USBDEV_SHARED_PRODUCT, "VUSB-I2C") != 0) {
 		fprintf(stderr,
-			"Could not find USB device \"PowerSwitch\" with vid=0x%x pid=0x%x\n",
+			"Could not find USB device \"VUSB-I2C\" with vid=0x%x pid=0x%x\n",
 			USBDEV_SHARED_VENDOR, USBDEV_SHARED_PRODUCT);
 		exit(1);
 	}
diff --git a/firmware/main.c b/firmware/main.c
index c6694d2..5a863e9 100644
--- a/firmware/main.c
+++ b/firmware/main.c
@@ -31,80 +31,24 @@ Application examples:
 
 #ifndef TEST_DRIVER_SIZE    /* define this to check out size of pure driver */
 
-static uchar    actionTimers[8];
-static uchar    permstatus = 255;
-
-/* This is the AT90S2313 version of the routine. Change for others. */
-static void outputByte(uchar b)
-{
-	DDRB  = ~b;
-}
-
-static uchar    computeTemporaryChanges(void)
-{
-	return 0;
-}
-
-static void computeOutputStatus(void)
-{
-    outputByte(permstatus);
-}
-
-/* We poll for the timer interrupt instead of declaring an interrupt handler
- * with global interrupts enabled. This saves recursion depth. Our timer does
- * not need high precision and does not run at a high rate anyway.
- */
-static void timerInterrupt(void)
-{
-static uchar    prescaler;
-uchar           i;
-
-    if(!prescaler--){
-        prescaler = 8;  /* rate = 12M / 1024 * 256 * 9 */
-        for(i=0;i<8;i++){
-            if(actionTimers[i])
-                actionTimers[i]--;
-        }
-        computeOutputStatus();
-    }
-}
-
 USB_PUBLIC uchar usbFunctionSetup(uchar data[8])
 {
 usbRequest_t    *rq = (void *)data;
-uchar           status = permstatus;
 static uchar    replyBuf[2];
 
     usbMsgPtr = replyBuf;
-    if(rq->bRequest == 0){  /* ECHO */
+    if(rq->bRequest == 0) {  /* ECHO */
         replyBuf[0] = rq->wValue.bytes[0];
         replyBuf[1] = rq->wValue.bytes[1];
         return 2;
     }
-    if(rq->bRequest == 1){  /* GET_STATUS -> result = 2 bytes */
+    if(rq->bRequest == 1) {  /* GET_STATUS -> result = 1 bytes */
         replyBuf[0] = PINB;
-        replyBuf[1] = computeTemporaryChanges();
-        return 2;
+        return 1;
     }
-    if(rq->bRequest == 2 || rq->bRequest == 3){ /* SWITCH_ON or SWITCH_OFF, index = bit number */
-        uchar bit = rq->wIndex.bytes[0] & 7;
-        uchar mask = 1 << bit;
-        uchar needChange, isOn = status & mask;
-        if(rq->bRequest == 2){  /* SWITCH_ON */
-            status |= mask;
-            needChange = !isOn;
-        }else{              /* SWITCH_OFF */
-            status &= ~mask;
-            needChange = isOn;
-        }
-        if(rq->wValue.bytes[0] == 0){   /* duration == 0 -> permanent switch */
-            actionTimers[bit] = 0;
-            permstatus = status;
-        }else if(needChange){   /* temporary switch: value = duration in 200ms units */
-            actionTimers[bit] = rq->wValue.bytes[0];
-        }
+    if(rq->bRequest == 2) { /* SET_STATUS. Payload byte is output. */
+        DDRB = ~(rq->wIndex.bytes[0]);
     }
-    computeOutputStatus();
     return 0;
 }
 
@@ -131,7 +75,6 @@ uchar   i;
  * that it should re-enumerate the device. Otherwise the host's and device's
  * concept of the device-ID would be out of sync.
  */
-    computeOutputStatus();  /* set output status before we do the delay */
     usbDeviceDisconnect();  /* enforce re-enumeration, do this while interrupts are disabled! */
     i = 0;
     while(--i){         /* fake USB disconnect for > 500 ms */
@@ -147,7 +90,10 @@ uchar   i;
         usbPoll();
         if(TIFR & (1 << TOV0)){
             TIFR |= 1 << TOV0;  /* clear pending flag */
-            timerInterrupt();
+            /*
+             * a periodic (low-frequency, low-accuracy) loop function can
+             * be placed here.
+             */
         }
     }
     return 0;
diff --git a/firmware/usbconfig.h b/firmware/usbconfig.h
index beaec6a..585d16d 100644
--- a/firmware/usbconfig.h
+++ b/firmware/usbconfig.h
@@ -141,8 +141,8 @@ the newest features and options.
 #define USB_CFG_DEVICE_VERSION  0x00, 0x01
 /* Version number of the device: Minor number first, then major number.
  */
-#define USB_CFG_VENDOR_NAME     'w', 'w', 'w', '.', 'o', 'b', 'd', 'e', 'v', '.', 'a', 't'
-#define USB_CFG_VENDOR_NAME_LEN 12
+#define USB_CFG_VENDOR_NAME     'f', 'i', 'n', 'a', 'l', 'r', 'e', 'w', 'i', 'n', 'd', '.', 'o', 'r', 'g'
+#define USB_CFG_VENDOR_NAME_LEN 15
 /* These two values define the vendor name returned by the USB device. The name
  * must be given as a list of characters under single quotes. The characters
  * are interpreted as Unicode (UTF-16) entities.
@@ -151,8 +151,8 @@ the newest features and options.
  * obdev's free shared VID/PID pair. See the file USBID-License.txt for
  * details.
  */
-#define USB_CFG_DEVICE_NAME     'P', 'o', 'w', 'e', 'r', 'S', 'w', 'i', 't', 'c', 'h'
-#define USB_CFG_DEVICE_NAME_LEN 11
+#define USB_CFG_DEVICE_NAME     'V', 'U', 'S', 'B', '-', 'I', '2', 'C'
+#define USB_CFG_DEVICE_NAME_LEN 8
 /* Same as above for the device name. If you don't want a device name, undefine
  * the macros. See the file USBID-License.txt before you assign a name.
  */