usb.h, usb.c: Cleanups

Remove wIstr. This cleans up the control flow. wIstr is still declared
in usb_lib/usb_regs.h, but it's unused throughout the code base.

Remove bIntPackSOF.  Only written, never read.

Signed-off-by: Marti Bolivar <mbolivar@leaflabs.com>

2 files changed, 18 insertions, 22 deletions

diff --git a/libmaple/usb/usb.c b/libmaple/usb/usb.c
index 6a22cdf..ec189d6 100644
--- a/libmaple/usb/usb.c
+++ b/libmaple/usb/usb.c
@@ -49,7 +49,6 @@ static void dispatch_ctr_lp(void);
  * usb_lib/ globals
  */
 
-volatile uint16 wIstr = 0;      /* most recently read value of wIstr */
 uint16 SaveTState;              /* caches TX status for later use */
 uint16 SaveRState;              /* caches RX status for later use */
 
@@ -57,8 +56,6 @@ uint16 SaveRState;              /* caches RX status for later use */
  * Other state
  */
 
-volatile uint32 bIntPackSOF = 0;
-
 struct {
   volatile RESUME_STATE eState;
   volatile uint8 bESOFcnt;
@@ -168,38 +165,38 @@ void usbResume(RESUME_STATE eResumeSetVal) {
 
 #define SUSPEND_ENABLED 1
 void __irq_usb_lp_can_rx0(void) {
-  wIstr = USB_BASE->ISTR;
+  uint16 istr = USB_BASE->ISTR;
 
   /* Use USB_ISR_MSK to only include code for bits we care about. */
 
 #if (USB_ISR_MSK & USB_ISTR_RESET)
-  if (wIstr & USB_ISTR_RESET & USBLIB->irq_mask) {
+  if (istr & USB_ISTR_RESET & USBLIB->irq_mask) {
     USB_BASE->ISTR = ~USB_ISTR_RESET;
     pProperty->Reset();
   }
 #endif
 
 #if (USB_ISR_MSK & USB_ISTR_PMAOVR)
-  if (wIstr & ISTR_PMAOVR & USBLIB->irq_mask) {
+  if (istr & ISTR_PMAOVR & USBLIB->irq_mask) {
     USB_BASE->ISTR = ~USB_ISTR_PMAOVR;
   }
 #endif
 
 #if (USB_ISR_MSK & USB_ISTR_ERR)
-  if (wIstr & USB_ISTR_ERR & USBLIB->irq_mask) {
+  if (istr & USB_ISTR_ERR & USBLIB->irq_mask) {
     USB_BASE->ISTR = ~USB_ISTR_ERR;
   }
 #endif
 
 #if (USB_ISR_MSK & USB_ISTR_WKUP)
-  if (wIstr & USB_ISTR_WKUP & USBLIB->irq_mask) {
+  if (istr & USB_ISTR_WKUP & USBLIB->irq_mask) {
     USB_BASE->ISTR = ~USB_ISTR_WKUP;
     usbResume(RESUME_EXTERNAL);
   }
 #endif
 
 #if (USB_ISR_MSK & USB_ISTR_SUSP)
-  if (wIstr & USB_ISTR_SUSP & USBLIB->irq_mask) {
+  if (istr & USB_ISTR_SUSP & USBLIB->irq_mask) {
     /* check if SUSPEND is possible */
     if (SUSPEND_ENABLED) {
         usbSuspend();
@@ -213,14 +210,13 @@ void __irq_usb_lp_can_rx0(void) {
 #endif
 
 #if (USB_ISR_MSK & USB_ISTR_SOF)
-  if (wIstr & USB_ISTR_SOF & USBLIB->irq_mask) {
+  if (istr & USB_ISTR_SOF & USBLIB->irq_mask) {
     USB_BASE->ISTR = ~USB_ISTR_SOF;
-    bIntPackSOF++;
   }
 #endif
 
 #if (USB_ISR_MSK & USB_ISTR_ESOF)
-  if (wIstr & USB_ISTR_ESOF & USBLIB->irq_mask) {
+  if (istr & USB_ISTR_ESOF & USBLIB->irq_mask) {
     USB_BASE->ISTR = ~USB_ISTR_ESOF;
     /* resume handling timing is made with ESOFs */
     usbResume(RESUME_ESOF); /* request without change of the machine state */
@@ -232,7 +228,7 @@ void __irq_usb_lp_can_rx0(void) {
    */
 
 #if (USB_ISR_MSK & USB_ISTR_CTR)
-  if (wIstr & USB_ISTR_CTR & USBLIB->irq_mask) {
+  if (istr & USB_ISTR_CTR & USBLIB->irq_mask) {
     dispatch_ctr_lp();
   }
 #endif
@@ -256,7 +252,7 @@ uint8 usbIsConnected() {
  * Auxiliary routines
  */
 
-static inline uint8 dispatch_endpt_zero(void);
+static inline uint8 dispatch_endpt_zero(uint16 istr_dir);
 static inline void dispatch_endpt(uint8 ep);
 static inline void set_rx_tx_status0(uint16 rx, uint16 tx);
 
@@ -264,19 +260,20 @@ static void handle_setup0(void);
 static void handle_in0(void);
 static void handle_out0(void);
 
-static void dispatch_ctr_lp(void) {
-    while (((wIstr = USB_BASE->ISTR) & USB_ISTR_CTR) != 0) {
+static void dispatch_ctr_lp() {
+    uint16 istr;
+    while (((istr = USB_BASE->ISTR) & USB_ISTR_CTR) != 0) {
         /* TODO WTF, figure this out: RM0008 says CTR is read-only,
          * but ST's firmware claims it's clear-only, and emphasizes
          * the importance of clearing it in more than one place. */
         USB_BASE->ISTR = ~USB_ISTR_CTR;
-        uint8 ep_id = wIstr & USB_ISTR_EP_ID;
+        uint8 ep_id = istr & USB_ISTR_EP_ID;
         if (ep_id == 0) {
             /* TODO figure out why it's OK to break out of the loop
              * once we're done serving endpoint zero, but not okay if
              * there are multiple nonzero endpoint transfers to
              * handle. */
-            if (dispatch_endpt_zero())
+            if (dispatch_endpt_zero(istr & USB_ISTR_DIR))
                 return;
         } else {
             dispatch_endpt(ep_id);
@@ -288,7 +285,7 @@ static void dispatch_ctr_lp(void) {
  * code, and is ugly/confusing in its use of SaveRState/SaveTState.
  * Fixing this requires filling in handle_in0(), handle_setup0(),
  * handle_out0(). */
-static inline uint8 dispatch_endpt_zero(void) {
+static inline uint8 dispatch_endpt_zero(uint16 istr_dir) {
     uint32 epr = (uint16)USB_BASE->EP[0];
 
     if (!(epr & (USB_EP_CTR_TX | USB_EP_SETUP | USB_EP_CTR_RX))) {
@@ -304,7 +301,7 @@ static inline uint8 dispatch_endpt_zero(void) {
     /* Set actual RX/TX statuses to NAK while we're thinking */
     set_rx_tx_status0(USB_EP_STAT_RX_NAK, USB_EP_STAT_TX_NAK);
 
-    if ((wIstr & USB_ISTR_DIR) == 0) {
+    if (istr_dir == 0) {
         /* ST RM0008: "If DIR bit=0, CTR_TX bit is set in the USB_EPnR
          * register related to the interrupting endpoint.  The
          * interrupting transaction is of IN type (data transmitted by
diff --git a/libmaple/usb/usb.h b/libmaple/usb/usb.h
index b073156..107ea77 100644
--- a/libmaple/usb/usb.h
+++ b/libmaple/usb/usb.h
@@ -27,8 +27,7 @@
 #ifndef _USB_H_
 #define _USB_H_
 
-#include "libmaple.h"
-#include "gpio.h"
+#include "libmaple_types.h"
 
 #ifdef __cplusplus
 extern "C" {