From 9c15daf7606d9a8ae58736963c8130cf7f4333ea Mon Sep 17 00:00:00 2001
From: Martin Mares <mj@ucw.cz>
Date: Tue, 26 Jun 2018 16:07:55 +0200
Subject: [PATCH] Request/reply protocol

---
 Inc/app.h    | 11 ++++++++---
 Src/main.c   | 17 ++++++-----------
 Src/usbdev.c | 23 +++++++++--------------
 host/test.c  |  6 ++----
 4 files changed, 25 insertions(+), 32 deletions(-)

diff --git a/Inc/app.h b/Inc/app.h
index d975287..1fb9965 100644
--- a/Inc/app.h
+++ b/Inc/app.h
@@ -1,10 +1,15 @@
 // main.c
 
-extern byte rx_display[8];
-extern volatile byte rx_display_ready;
-
 // display.c
 
 void display_init(void);
 void display_counter(uint cnt);
 void display_buffer(byte *buf);
+
+// usbdev.c
+
+extern byte rx_packet[64];
+extern byte tx_packet[64];
+extern volatile byte rx_packet_state, tx_packet_state;
+
+void tx_packet_send(void);
diff --git a/Src/main.c b/Src/main.c
index bb225b2..e77264b 100644
--- a/Src/main.c
+++ b/Src/main.c
@@ -73,8 +73,6 @@ static void MX_TIM4_Init(void);
 /* USER CODE END PFP */
 
 /* USER CODE BEGIN 0 */
-byte rx_display[8];
-volatile byte rx_display_ready;
 
 /* USER CODE END 0 */
 
@@ -143,17 +141,14 @@ int main(void)
   /* USER CODE BEGIN WHILE */
   while (1)
   {
-    __disable_irq();
-    if (rx_display_ready)
+    if (rx_packet_state == 1 && !tx_packet_state)
       {
-	byte rx[8];
-	rx_display_ready = 0;
-	memcpy(rx, rx_display, 8);
-	__enable_irq();
-	display_buffer(rx);
+	display_buffer(rx_packet);
+	tx_packet_state = 1;
+	usb_ep_send(&usb, 0x82, tx_packet, 8);
+	rx_packet_state = 0;
+	usb_ep_receive(&usb, 0x01, rx_packet, 64);
       }
-    else
-      __enable_irq();
 
     // debug_printf("Counter = %d\n", cnt);
     // display_counter(cnt);
diff --git a/Src/usbdev.c b/Src/usbdev.c
index 9713bc8..4834592 100644
--- a/Src/usbdev.c
+++ b/Src/usbdev.c
@@ -91,8 +91,9 @@ static const byte desc_languages[] = {
 
 /*** Callbacks ***/
 
-static byte usb_rx_buf[64];
-static byte usb_tx_buf[64];
+byte rx_packet[64];
+byte tx_packet[64];
+volatile byte rx_packet_state, tx_packet_state;
 
 void usb_dev_reset(struct usb *usb)
 {
@@ -110,7 +111,7 @@ void usb_dev_configure(struct usb *usb)
 {
   usb_ep_open(usb, 0x01, USB_EP_TYPE_BULK, 64);
   usb_ep_open(usb, 0x82, USB_EP_TYPE_BULK, 64);
-  usb_ep_receive(usb, 0x01, usb_rx_buf, 64);
+  usb_ep_receive(usb, 0x01, rx_packet, 64);
 }
 
 void usb_dev_unconfigure(struct usb *usb)
@@ -136,21 +137,15 @@ void usb_dev_recv_done(struct usb *usb, byte epnum)
 {
   if (epnum == 0x01)
     {
-      // usb_tx_buf[0]++;
-      // usb_ep_send(usb, 0x82, usb_tx_buf, 33);
-
       u32 len = usb_ep_received_size(usb, 0x01);
-      if (len >= 8)
-	{
-	  memcpy(rx_display, usb_rx_buf, 8);
-	  rx_display_ready = 1;
-	}
-
-      usb_ep_receive(usb, 0x01, usb_rx_buf, 64);
+      if (len >= 8 && !rx_packet_state)
+	rx_packet_state = 1;
+      else
+	usb_ep_receive(usb, 0x01, rx_packet, 64);
     }
 }
 
 void usb_dev_send_done(struct usb *usb, byte epnum)
 {
-  // usb_ep_receive(usb, 0x01, usb_rx_buf, 64);
+  tx_packet_state = 0;
 }
diff --git a/host/test.c b/host/test.c
index 07b804e..ce91851 100644
--- a/host/test.c
+++ b/host/test.c
@@ -81,16 +81,14 @@ int main(void)
 	}
       printf("Transferred %d bytes\n", transferred);
 
-#if 0
-      unsigned char resp[1000];
+      unsigned char resp[64];
       int received;
-      if (err = libusb_bulk_transfer(devh, 0x82, resp, 1000, &received, 2000))
+      if (err = libusb_bulk_transfer(devh, 0x82, resp, 64, &received, 2000))
 	{
 	  fprintf(stderr, "Receive failed: error %d\n", err);
 	  exit(1);
 	}
       printf("Received %d bytes [%02x]\n", received, resp[0]);
-#endif
 
       sleep(1);
     }
-- 
2.39.2