From b6b473a6a1fde7e7154dc2f1a2abaa395d526f62 Mon Sep 17 00:00:00 2001
From: gdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4>
Date: Mon, 13 Aug 2012 10:14:45 +0000
Subject: Performance improvements to the STM32 OTG driver.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@4562 35acf78f-673a-0410-8e92-d51de3d6d3f4
---
 os/hal/include/serial_usb.h            |  4 +-
 os/hal/platforms/STM32/OTGv1/usb_lld.c | 67 +++++++++++++++++++++-------------
 os/hal/platforms/STM32/OTGv1/usb_lld.h |  6 +++
 3 files changed, 49 insertions(+), 28 deletions(-)

(limited to 'os/hal')

diff --git a/os/hal/include/serial_usb.h b/os/hal/include/serial_usb.h
index 4ad65d76d..104375391 100644
--- a/os/hal/include/serial_usb.h
+++ b/os/hal/include/serial_usb.h
@@ -47,11 +47,11 @@
  * @brief   Serial over USB buffers size.
  * @details Configuration parameter, the buffer size must be a multiple of
  *          the USB data endpoint maximum packet size.
- * @note    The default is 64 bytes for both the transmission and receive
+ * @note    The default is 256 bytes for both the transmission and receive
  *          buffers.
  */
 #if !defined(SERIAL_USB_BUFFERS_SIZE) || defined(__DOXYGEN__)
-#define SERIAL_USB_BUFFERS_SIZE     64
+#define SERIAL_USB_BUFFERS_SIZE     256
 #endif
 /** @} */
 
diff --git a/os/hal/platforms/STM32/OTGv1/usb_lld.c b/os/hal/platforms/STM32/OTGv1/usb_lld.c
index b4238a8a0..78fc45a71 100644
--- a/os/hal/platforms/STM32/OTGv1/usb_lld.c
+++ b/os/hal/platforms/STM32/OTGv1/usb_lld.c
@@ -85,6 +85,7 @@ static const USBEndpointConfig ep0config = {
   0x40,
   &ep0_state.in,
   &ep0_state.out,
+  1,
   ep0setup_buffer
 };
 
@@ -448,31 +449,43 @@ static void otg_rxfifo_handler(USBDriver *usbp) {
  * @notapi
  */
 static void otg_txfifo_handler(USBDriver *usbp, usbep_t ep) {
-  uint32_t n;
-
-  /* Number of bytes remaining in current transaction.*/
-  n = usbp->epc[ep]->in_state->txsize - usbp->epc[ep]->in_state->txcnt;
-  if (n > usbp->epc[ep]->in_maxsize)
-    n = usbp->epc[ep]->in_maxsize;
-
-  if (usbp->epc[ep]->in_state->txqueued) {
-    /* Queue associated.*/
-    otg_fifo_write_from_queue(ep,
-                              usbp->epc[ep]->in_state->mode.queue.txqueue,
-                              n);
-  }
-  else {
-    /* Linear buffer associated.*/
-    otg_fifo_write_from_buffer(ep,
-                               usbp->epc[ep]->in_state->mode.linear.txbuf,
-                               n);
-    usbp->epc[ep]->in_state->mode.linear.txbuf += n;
-  }
-  usbp->epc[ep]->in_state->txcnt += n;
 
-  /* Interrupt disabled on transaction end.*/
-  if (usbp->epc[ep]->in_state->txcnt >= usbp->epc[ep]->in_state->txsize)
-    OTG->DIEPEMPMSK &= ~DIEPEMPMSK_INEPTXFEM(ep);
+  /* The TXFIFO is filled until there is space and data to be transmitted.*/
+  while (TRUE) {
+    uint32_t n;
+
+    /* Number of bytes remaining in current transaction.*/
+    n = usbp->epc[ep]->in_state->txsize - usbp->epc[ep]->in_state->txcnt;
+    if (n > usbp->epc[ep]->in_maxsize)
+      n = usbp->epc[ep]->in_maxsize;
+
+    /* Checks if in the TXFIFO there is enough space to accommodate the
+       next packet.*/
+    if (((OTG->ie[ep].DTXFSTS & DTXFSTS_INEPTFSAV_MASK) * 4) < n)
+      return;
+
+    /* Handles the two cases: linear buffer or queue.*/
+    if (usbp->epc[ep]->in_state->txqueued) {
+      /* Queue associated.*/
+      otg_fifo_write_from_queue(ep,
+                                usbp->epc[ep]->in_state->mode.queue.txqueue,
+                                n);
+    }
+    else {
+      /* Linear buffer associated.*/
+      otg_fifo_write_from_buffer(ep,
+                                 usbp->epc[ep]->in_state->mode.linear.txbuf,
+                                 n);
+      usbp->epc[ep]->in_state->mode.linear.txbuf += n;
+    }
+    usbp->epc[ep]->in_state->txcnt += n;
+
+    /* Interrupt disabled on transaction end.*/
+    if (usbp->epc[ep]->in_state->txcnt >= usbp->epc[ep]->in_state->txsize) {
+      OTG->DIEPEMPMSK &= ~DIEPEMPMSK_INEPTXFEM(ep);
+      return;
+    }
+  }
 }
 
 /**
@@ -650,8 +663,8 @@ void usb_lld_start(USBDriver *usbp) {
        - Full Speed 1.1 PHY.*/
     OTG->GUSBCFG = GUSBCFG_FDMOD | GUSBCFG_TRDT(TRDT_VALUE) | GUSBCFG_PHYSEL;
 
-    /* Interrupt on TXFIFOs empty.*/
-    OTG->GAHBCFG = GAHBCFG_PTXFELVL | GAHBCFG_TXFELVL;
+    /* Interrupts on TXFIFOs half empty.*/
+    OTG->GAHBCFG = 0;
 
     /* 48MHz 1.1 PHY.*/
     OTG->DCFG = 0x02200000 |  DCFG_PFIVL(0) | DCFG_DSPD_FS11;
@@ -806,6 +819,8 @@ void usb_lld_init_endpoint(USBDriver *usbp, usbep_t ep) {
   if (usbp->epc[ep]->in_cb != NULL) {
     /* FIFO allocation for the IN endpoint.*/
     fsize = usbp->epc[ep]->in_maxsize / 4;
+    if (usbp->epc[ep]->in_multiplier > 1)
+      fsize *= usbp->epc[ep]->in_multiplier;
     OTG->DIEPTXF[ep - 1] = DIEPTXF_INEPTXFD(fsize) |
                            DIEPTXF_INEPTXSA(otg_ram_alloc(usbp, fsize));
     otg_txfifo_flush(ep);
diff --git a/os/hal/platforms/STM32/OTGv1/usb_lld.h b/os/hal/platforms/STM32/OTGv1/usb_lld.h
index 8b2903982..30e96c71b 100644
--- a/os/hal/platforms/STM32/OTGv1/usb_lld.h
+++ b/os/hal/platforms/STM32/OTGv1/usb_lld.h
@@ -231,6 +231,12 @@ typedef struct {
    */
   USBOutEndpointState           *out_state;
   /* End of the mandatory fields.*/
+  /**
+   * @brief   Determines the space allocated for the TXFIFO as multiples of
+   *          the packet size (@p in_maxsize). Note that zero is interpreted
+   *          as one for simplicity and robustness.
+   */
+  uint16_t                      in_multiplier;
   /**
    * @brief   Pointer to a buffer for setup packets.
    * @details Setup packets require a dedicated 8-bytes buffer, set this
-- 
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