Fix USB CDC receive code (#299)

ZigEmbeddedGroup · Nov 30, 2024 · 50e684d · 50e684d
1 parent b1fd122
commit 50e684d
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Showing 3 changed files with 23 additions and 14 deletions.
diff --git a/core/src/core/usb.zig b/core/src/core/usb.zig
@@ -96,12 +96,12 @@ pub fn Usb(comptime f: anytype) type {
                 const data_chunk = S.buffer_reader.try_peek(64);
 
                 if (data_chunk.len > 0) {
-                    f.usb_start_tx(Endpoint.EP0_IN_IDX, data_chunk);
+                    f.usb_start_tx(Endpoint.EP0_IN_ADDR, data_chunk);
                 }
             }
 
             fn send_cmd_ack() void {
-                f.usb_start_tx(Endpoint.EP0_IN_IDX, &.{});
+                f.usb_start_tx(Endpoint.EP0_IN_ADDR, &.{});
             }
         };
 
@@ -441,12 +441,12 @@ pub fn Usb(comptime f: anytype) type {
                                 const next_data_chunk = buffer_reader.try_peek(64);
                                 if (next_data_chunk.len > 0) {
                                     f.usb_start_tx(
-                                         Endpoint.EP0_IN_IDX,
+                                         Endpoint.EP0_IN_ADDR,
                                          next_data_chunk,
                                      );
                                 } else {
                                     f.usb_start_rx(
-                                        Endpoint.EP0_OUT_IDX,
+                                        Endpoint.EP0_OUT_ADDR,
                                         0,
                                     );
 
@@ -461,7 +461,7 @@ pub fn Usb(comptime f: anytype) type {
                                 // OUT) a zero-byte DATA packet, so, set that
                                 // up:
                                 f.usb_start_rx(
-                                    Endpoint.EP0_OUT_IDX,
+                                    Endpoint.EP0_OUT_ADDR,
                                     0,
                                 );
 
@@ -477,6 +477,9 @@ pub fn Usb(comptime f: anytype) type {
                             if (driver != null) {
                                 driver.?.transfer(epb.endpoint_address, epb.buffer);
                             }
+                            if (Endpoint.dir_from_address(epb.endpoint_address) == .Out) {
+                                f.endpoint_reset_rx(epb.endpoint_address);
+                            }
                         },
                     }
                 }

diff --git a/core/src/core/usb/types.zig b/core/src/core/usb/types.zig
@@ -95,9 +95,6 @@ pub const Endpoint = struct {
         return if (addr & Dir.DIR_IN_MASK != 0) Dir.In else Dir.Out;
     }
 
-    pub const EP0_OUT_IDX = 0;
-    pub const EP0_IN_IDX = 1;
-
     pub const EP0_IN_ADDR: u8 = to_address(0, .In);
     pub const EP0_OUT_ADDR: u8 = to_address(0, .Out);
 };

diff --git a/port/raspberrypi/rp2xxx/src/hal/usb.zig b/port/raspberrypi/rp2xxx/src/hal/usb.zig
@@ -21,9 +21,6 @@ const resets = @import("resets.zig");
 
 pub const RP2XXX_MAX_ENDPOINTS_COUNT = 16;
 
-pub const EP0_OUT_IDX = 0;
-pub const EP0_IN_IDX = 1;
-
 pub const UsbConfig = struct {
     // Comptime defined supported max endpoints number, can be reduced to save RAM space
     max_endpoints_count: u8 = RP2XXX_MAX_ENDPOINTS_COUNT,
@@ -65,6 +62,7 @@ const HardwareEndpoint = struct {
     endpoint_control_index: usize,
     buffer_control_index: usize,
     data_buffer_index: usize,
+    awaiting_rx: bool,
 };
 
 // +++++++++++++++++++++++++++++++++++++++++++++++++
@@ -346,6 +344,9 @@ pub fn F(comptime config: UsbConfig) type {
 
             const ep = hardware_endpoint_get_by_address(ep_addr);
 
+            if (ep.awaiting_rx)
+                return;
+
             // Check which DATA0/1 PID this endpoint is expecting next.
             const np: u1 = if (ep.next_pid_1) 1 else 0;
             // Configure the OUT:
@@ -358,6 +359,12 @@ pub fn F(comptime config: UsbConfig) type {
 
             // Flip the DATA0/1 PID for the next receive
             ep.next_pid_1 = !ep.next_pid_1;
+            ep.awaiting_rx = true;
+        }
+
+        pub fn endpoint_reset_rx(ep_addr: u8) void {
+            const ep = hardware_endpoint_get_by_address(ep_addr);
+            ep.awaiting_rx = false;
         }
 
         /// Check which interrupt flags are set
@@ -414,7 +421,7 @@ pub fn F(comptime config: UsbConfig) type {
         }
 
         pub fn reset_ep0() void {
-            var ep = hardware_endpoint_get_by_address(Endpoint.EP0_IN_IDX);
+            var ep = hardware_endpoint_get_by_address(Endpoint.EP0_IN_ADDR);
             ep.next_pid_1 = true;
         }
 
@@ -443,14 +450,16 @@ pub fn F(comptime config: UsbConfig) type {
             ep.max_packet_size = max_packet_size;
             ep.transfer_type = transfer_type;
             ep.next_pid_1 = false;
+            ep.awaiting_rx = false;
 
             ep.buffer_control_index = 2 * ep_num + ep_dir.as_number_reversed();
-            // TODO - some other way to deal with it
-            ep.data_buffer_index = 2 * ep_num + ep_dir.as_number();
 
             if (ep_num == 0) {
+                ep.data_buffer_index = 0;
                 ep.endpoint_control_index = 0;
             } else {
+                // TODO - some other way to deal with it
+                ep.data_buffer_index = 2 * ep_num + ep_dir.as_number();
                 ep.endpoint_control_index = 2*ep_num - ep_dir.as_number();
                 endpoint_alloc(ep, transfer_type);
             }