altos/lpc: Double buffer USB data transfers

[fw/altos] / src / lpc / ao_usb_lpc.c

diff --git a/src/lpc/ao_usb_lpc.c b/src/lpc/ao_usb_lpc.c
index 78fbac3985ea848e3a519c2c977562c193ab3774..0dfaece480dc0f60f0b2bcb245b1e3578395ccc2 100644 (file)
--- a/src/lpc/ao_usb_lpc.c
+++ b/src/lpc/ao_usb_lpc.c
@@ -80,14 +80,12 @@ static uint8_t      *ao_usb_ep0_setup_buffer;
 static uint8_t *ao_usb_ep0_rx_buffer;
 
 /* Pointer to bulk data tx/rx buffers in USB memory */
-static uint8_t *ao_usb_in_tx_buffer;
-static uint8_t *ao_usb_out_rx_buffer;
-
-/* Our data buffers */
-static uint8_t ao_usb_tx_buffer[AO_USB_IN_SIZE];
+static uint8_t *ao_usb_in_tx_buffer[2];
+static uint8_t ao_usb_in_tx_cur;
 static uint8_t ao_usb_tx_count;
 
-static uint8_t ao_usb_rx_buffer[AO_USB_OUT_SIZE];
+static uint8_t *ao_usb_out_rx_buffer[2];
+static uint8_t ao_usb_out_rx_cur;
 static uint8_t ao_usb_rx_count, ao_usb_rx_pos;
 
 extern struct lpc_usb_endpoint lpc_usb_endpoint;
@@ -294,18 +292,24 @@ ao_usb_disable_ep(vuint32_t *ep)
 }
 
 static void
-ao_usb_enable_epn(uint8_t n, uint16_t out_bytes, uint8_t **out_addr, uint16_t in_bytes, uint8_t **in_addr)
+ao_usb_enable_epn(uint8_t n,
+                 uint16_t out_bytes, uint8_t *out_addrs[2],
+                 uint16_t in_bytes, uint8_t *in_addrs[2])
 {
        uint8_t *addr;
 
-       addr = ao_usb_enable_ep(ao_usb_epn_out(n, 0), out_bytes, out_bytes);
-       if (out_addr)
-               *out_addr = addr;
+       addr = ao_usb_enable_ep(ao_usb_epn_out(n, 0), out_bytes * 2, out_bytes);
+       if (out_addrs) {
+               out_addrs[0] = addr;
+               out_addrs[1] = addr + out_bytes;
+       }
        ao_usb_disable_ep(ao_usb_epn_out(n, 1));
 
-       addr = ao_usb_enable_ep(ao_usb_epn_in(n, 0), in_bytes, 0);
-       if (in_addr)
-               *in_addr = addr;
+       addr = ao_usb_enable_ep(ao_usb_epn_in(n, 0), in_bytes * 2, 0);
+       if (in_addrs) {
+               in_addrs[0] = addr;
+               in_addrs[1] = addr + in_bytes;
+       }
        ao_usb_disable_ep(ao_usb_epn_in(n, 1));
 }
 
@@ -362,12 +366,18 @@ ao_usb_set_configuration(void)
 
        /* Set up the INT end point */
        ao_usb_enable_epn(AO_USB_INT_EP, 0, NULL, 0, NULL);
-       
+
        /* Set up the OUT end point */
-       ao_usb_enable_epn(AO_USB_OUT_EP, AO_USB_OUT_SIZE, &ao_usb_out_rx_buffer, 0, NULL);
+       ao_usb_enable_epn(AO_USB_OUT_EP, AO_USB_OUT_SIZE, ao_usb_out_rx_buffer, 0, NULL);
+
+       /* Set the current RX pointer to the *other* buffer so that when buffer 0 gets
+        * data, we'll switch to it and pull bytes from there
+        */
+       ao_usb_out_rx_cur = 1;
 
        /* Set up the IN end point */
-       ao_usb_enable_epn(AO_USB_IN_EP, 0, NULL, AO_USB_IN_SIZE, &ao_usb_in_tx_buffer);
+       ao_usb_enable_epn(AO_USB_IN_EP, 0, NULL, AO_USB_IN_SIZE, ao_usb_in_tx_buffer);
+       ao_usb_in_tx_cur = 0;
 
        ao_usb_running = 1;
 }
@@ -716,8 +726,8 @@ _ao_usb_in_send(void)
        ao_usb_in_pending = 1;
        if (ao_usb_tx_count != AO_USB_IN_SIZE)
                ao_usb_in_flushed = 1;
-       memcpy(ao_usb_in_tx_buffer, ao_usb_tx_buffer, ao_usb_tx_count);
-       ao_usb_set_ep(ao_usb_epn_in(AO_USB_IN_EP, 0), ao_usb_in_tx_buffer, ao_usb_tx_count);
+       ao_usb_set_ep(ao_usb_epn_in(AO_USB_IN_EP, 0), ao_usb_in_tx_buffer[ao_usb_in_tx_cur], ao_usb_tx_count);
+       ao_usb_in_tx_cur = 1 - ao_usb_in_tx_cur;
        ao_usb_tx_count = 0;
        _tx_dbg0("in_send end");
 }
@@ -771,7 +781,7 @@ ao_usb_putchar(char c)
        _ao_usb_in_wait();
 
        ao_usb_in_flushed = 0;
-       ao_usb_tx_buffer[ao_usb_tx_count++] = (uint8_t) c;
+       ao_usb_in_tx_buffer[ao_usb_in_tx_cur][ao_usb_tx_count++] = (uint8_t) c;
 
        /* Send the packet when full */
        if (ao_usb_tx_count == AO_USB_IN_SIZE) {
@@ -792,13 +802,12 @@ _ao_usb_out_recv(void)
 
        _rx_dbg1("out_recv count", ao_usb_rx_count);
        debug ("recv %d\n", ao_usb_rx_count);
-       debug_data("Fill OUT len %d:", ao_usb_rx_count);
-       memcpy(ao_usb_rx_buffer, ao_usb_out_rx_buffer, ao_usb_rx_count);
-       debug_data("\n");
+       debug_data("Fill OUT len %d\n", ao_usb_rx_count);
        ao_usb_rx_pos = 0;
+       ao_usb_out_rx_cur = 1 - ao_usb_out_rx_cur;
 
        /* ACK the packet */
-       ao_usb_set_epn_out(AO_USB_OUT_EP, ao_usb_out_rx_buffer, AO_USB_OUT_SIZE);
+       ao_usb_set_epn_out(AO_USB_OUT_EP, ao_usb_out_rx_buffer[1-ao_usb_out_rx_cur], AO_USB_OUT_SIZE);
 }
 
 int
@@ -823,7 +832,7 @@ _ao_usb_pollchar(void)
        }
 
        /* Pull a character out of the fifo */
-       c = ao_usb_rx_buffer[ao_usb_rx_pos++];
+       c = ao_usb_out_rx_buffer[ao_usb_out_rx_cur][ao_usb_rx_pos++];
        return c;
 }