usb: Clean up some globals with new struct usblib_dev.

Add struct usblib_dev (and USBLIB, a pointer to the singleton) to
usb.h.  USBLIB contains the global state which is used by
functionality imported from usb_lib/.

Consolidating global state into USBLIB will make it easier to remove
later.

Initial fields in struct usblib_dev are endpoint interrupt callbacks,
a mask for what to handle in the low-priority USB interrupt, and
device state.  These replace pEpInt_IN, pEpInt_OUT; wInterrupt_Mask;
and bDeviceState, respectively from usb_lib/, so remove their
declarations from usb_lib_globals.h accordingly.  Also remove unused
SaveState declaration from usblib_globals.h. Move bDeviceState into
'state' field in usblib_dev.  Device state type changes from
DEVICE_STATE to usb_dev_state, volatile gets dropped, and enumerators
get a 'USB_' prefix, but it's otherwise the same.

usb_lib/ expects pInformation to point to   Device_Info,
                 pUser_Standard_Requests -> User_Standard_Requests, and
                 pProperty               -> Device_Property.

Alter usb_init_usblib() to reflect these assumptions.  Reorganize
usb_lib_globals.h to make these assumptions more apparent to the
reader.

Modify usb_init_usblib() to take endpoint callbacks as arguments;
update its caller in usb_cdcacm.c.

usb_lib/ defines pInformation, pProperty, and pUser_Standard_Requests
itself (in usb_init.c), but we have our own definitions (in usb.c).
Remove the duplicates from usb.c.  Also remove EPindex and Device_Info
definitions from usb.c. Unused, and anyways already defined in
usb_lib/usb_init.c.

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

4 files changed, 94 insertions, 79 deletions

diff --git a/libmaple/usb/usb.c b/libmaple/usb/usb.c
index 0206bb8..6a22cdf 100644
--- a/libmaple/usb/usb.c
+++ b/libmaple/usb/usb.c
@@ -49,21 +49,14 @@ static void dispatch_ctr_lp(void);
  * usb_lib/ globals
  */
 
-volatile uint16 wIstr = 0;
-uint8 EPindex;                  /* current endpoint */
-DEVICE_INFO *pInformation;
-DEVICE_PROP *pProperty;
+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 */
-uint16 wInterrupt_Mask;
-DEVICE_INFO Device_Info;
-USER_STANDARD_REQUESTS *pUser_Standard_Requests;
 
 /*
  * Other state
  */
 
-volatile uint32 bDeviceState = UNCONNECTED;
 volatile uint32 bIntPackSOF = 0;
 
 struct {
@@ -71,18 +64,31 @@ struct {
   volatile uint8 bESOFcnt;
 } ResumeS;
 
+static usblib_dev usblib = {
+    .irq_mask = USB_ISR_MSK,
+    .state = USB_UNCONNECTED,
+};
+usblib_dev *USBLIB = &usblib;
+
 /*
  * Routines
  */
 
-void usb_init_usblib(DEVICE_PROP *device, USER_STANDARD_REQUESTS *user) {
+void usb_init_usblib(void (**ep_int_in)(void), void (**ep_int_out)(void)) {
     rcc_clk_enable(RCC_USB);
 
+    USBLIB->ep_int_in = ep_int_in;
+    USBLIB->ep_int_out = ep_int_out;
+
+    /* usb_lib/ declares both and then assumes that pFoo points to Foo
+     * (even though the names don't always match), which is stupid for
+     * all of the obvious reasons, but whatever.  Here we are. */
     pInformation = &Device_Info;
+    pProperty = &Device_Property;
+    pUser_Standard_Requests = &User_Standard_Requests;
+
     pInformation->ControlState = 2; /* FIXME [0.0.12] use
                                        CONTROL_STATE enumerator */
-    pProperty = device;
-    pUser_Standard_Requests = user;
     pProperty->Init();
 }
 
@@ -97,7 +103,7 @@ void usbSuspend(void) {
   cntr |= USB_CNTR_LP_MODE;
   USB_BASE->CNTR = cntr;
 
-  bDeviceState = SUSPENDED;
+  USBLIB->state = USB_SUSPENDED;
 }
 
 void usbResumeInit(void) {
@@ -167,33 +173,33 @@ void __irq_usb_lp_can_rx0(void) {
   /* 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 & wInterrupt_Mask) {
+  if (wIstr & 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 & wInterrupt_Mask) {
+  if (wIstr & ISTR_PMAOVR & USBLIB->irq_mask) {
     USB_BASE->ISTR = ~USB_ISTR_PMAOVR;
   }
 #endif
 
 #if (USB_ISR_MSK & USB_ISTR_ERR)
-  if (wIstr & USB_ISTR_ERR & wInterrupt_Mask) {
+  if (wIstr & 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 & wInterrupt_Mask) {
+  if (wIstr & 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 & wInterrupt_Mask) {
+  if (wIstr & USB_ISTR_SUSP & USBLIB->irq_mask) {
     /* check if SUSPEND is possible */
     if (SUSPEND_ENABLED) {
         usbSuspend();
@@ -207,14 +213,14 @@ void __irq_usb_lp_can_rx0(void) {
 #endif
 
 #if (USB_ISR_MSK & USB_ISTR_SOF)
-  if (wIstr & USB_ISTR_SOF & wInterrupt_Mask) {
+  if (wIstr & 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 & wInterrupt_Mask) {
+  if (wIstr & 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 */
@@ -226,7 +232,7 @@ void __irq_usb_lp_can_rx0(void) {
    */
 
 #if (USB_ISR_MSK & USB_ISTR_CTR)
-  if (wIstr & USB_ISTR_CTR & wInterrupt_Mask) {
+  if (wIstr & USB_ISTR_CTR & USBLIB->irq_mask) {
     dispatch_ctr_lp();
   }
 #endif
@@ -239,11 +245,11 @@ void usbWaitReset(void) {
 }
 
 uint8 usbIsConfigured() {
-  return (bDeviceState == CONFIGURED);
+  return USBLIB->state == USB_CONFIGURED;
 }
 
 uint8 usbIsConnected() {
-  return (bDeviceState != UNCONNECTED);
+  return USBLIB->state != USB_UNCONNECTED;
 }
 
 /*
@@ -349,11 +355,11 @@ static inline void dispatch_endpt(uint8 ep) {
      * TODO try to find out if neither being set is possible. */
     if (epr & USB_EP_CTR_RX) {
         usb_clear_ctr_rx(ep);
-        (pEpInt_OUT[ep - 1])();
+        (USBLIB->ep_int_out[ep - 1])();
     }
     if (epr & USB_EP_CTR_TX) {
         usb_clear_ctr_tx(ep);
-        (pEpInt_IN[ep - 1])();
+        (USBLIB->ep_int_in[ep - 1])();
     }
 }
 
diff --git a/libmaple/usb/usb.h b/libmaple/usb/usb.h
index 8ab40f0..b073156 100644
--- a/libmaple/usb/usb.h
+++ b/libmaple/usb/usb.h
@@ -39,6 +39,25 @@ extern "C" {
 #define USB_ISR_MSK 0xBF00
 #endif
 
+typedef enum usb_dev_state {
+    USB_UNCONNECTED,
+    USB_ATTACHED,
+    USB_POWERED,
+    USB_SUSPENDED,
+    USB_ADDRESSED,
+    USB_CONFIGURED
+} usb_dev_state;
+
+/* Encapsulates global state formerly handled by usb_lib/
+ * functionality */
+typedef struct usblib_dev {
+    uint32 irq_mask;
+    void (**ep_int_in)(void);
+    void (**ep_int_out)(void);
+    usb_dev_state state;
+} usblib_dev;
+
+extern usblib_dev *USBLIB;
 
 /*
  * Convenience routines, etc.
@@ -55,21 +74,7 @@ typedef enum {
     RESUME_ESOF
 } RESUME_STATE;
 
-typedef enum {
-    UNCONNECTED,
-    ATTACHED,
-    POWERED,
-    SUSPENDED,
-    ADDRESSED,
-    CONFIGURED
-} DEVICE_STATE;
-
-extern volatile uint32 bDeviceState;
-
-struct _DEVICE_PROP;
-struct _USER_STANDARD_REQUESTS;
-void usb_init_usblib(struct _DEVICE_PROP*,
-                     struct _USER_STANDARD_REQUESTS*);
+void usb_init_usblib(void (**ep_int_in)(void), void (**ep_int_out)(void));
 
 void usbSuspend(void);
 void usbResumeInit(void);
diff --git a/libmaple/usb/usb_cdcacm.c b/libmaple/usb/usb_cdcacm.c
index bf73c68..46d56bb 100644
--- a/libmaple/usb/usb_cdcacm.c
+++ b/libmaple/usb/usb_cdcacm.c
@@ -118,6 +118,11 @@ typedef enum {
   DTR_LOW
 } RESET_STATE;
 
+/* Some forward-declared callbacks */
+void vcomDataTxCb(void);
+void vcomDataRxCb(void);
+void vcomManagementCb(void);
+
 const USB_Descriptor_Device usbVcomDescriptor_Device = {
     .bLength            = sizeof(USB_Descriptor_Device),
     .bDescriptorType    = USB_DESCRIPTOR_TYPE_DEVICE,
@@ -302,6 +307,24 @@ volatile uint32 newBytes = 0;
 RESET_STATE reset_state = DTR_UNSET;
 uint8       line_dtr_rts = 0;
 
+static void (*ep_int_in[7])(void) =
+    {vcomDataTxCb,
+     vcomManagementCb,
+     NOP_Process,
+     NOP_Process,
+     NOP_Process,
+     NOP_Process,
+     NOP_Process};
+
+static void (*ep_int_out[7])(void) =
+    {NOP_Process,
+     NOP_Process,
+     vcomDataRxCb,
+     NOP_Process,
+     NOP_Process,
+     NOP_Process,
+     NOP_Process};
+
 /*
  * VCOM callbacks
  */
@@ -388,11 +411,11 @@ void vcomSetLineState(void) {
 RESULT usbPowerOn(void) {
     USB_BASE->CNTR = USB_CNTR_FRES;
 
-    wInterrupt_Mask = 0;
-    USB_BASE->CNTR = wInterrupt_Mask;
+    USBLIB->irq_mask = 0;
+    USB_BASE->CNTR = USBLIB->irq_mask;
     USB_BASE->ISTR = 0;
-    wInterrupt_Mask = USB_CNTR_RESETM | USB_CNTR_SUSPM | USB_CNTR_WKUPM;
-    USB_BASE->CNTR = wInterrupt_Mask;
+    USBLIB->irq_mask = USB_CNTR_RESETM | USB_CNTR_SUSPM | USB_CNTR_WKUPM;
+    USB_BASE->CNTR = USBLIB->irq_mask;
 
     return USB_SUCCESS;
 }
@@ -402,11 +425,11 @@ void usbInit(void) {
     usbPowerOn();
 
     USB_BASE->ISTR = 0;
-    wInterrupt_Mask = USB_ISR_MSK;
-    USB_BASE->CNTR = wInterrupt_Mask;
+    USBLIB->irq_mask = USB_ISR_MSK;
+    USB_BASE->CNTR = USBLIB->irq_mask;
 
     nvic_irq_enable(NVIC_USB_LP_CAN_RX0);
-    bDeviceState = UNCONNECTED;
+    USBLIB->state = USB_UNCONNECTED;
 }
 
 /* choose addresses to give endpoints the max 64 byte buffers */
@@ -450,7 +473,7 @@ void usbReset(void) {
     usb_set_ep_tx_stat(VCOM_TX_ENDP, USB_EP_STAT_TX_NAK);
     usb_set_ep_rx_stat(VCOM_TX_ENDP, USB_EP_STAT_RX_DISABLED);
 
-    bDeviceState = ATTACHED;
+    USBLIB->state = USB_ATTACHED;
     SetDeviceAddress(0);
 
     /* reset the rx fifo */
@@ -585,12 +608,12 @@ u8* usbGetStringDescriptor(u16 length) {
 /* internal callbacks to respond to standard requests */
 void usbSetConfiguration(void) {
     if (pInformation->Current_Configuration != 0) {
-        bDeviceState = CONFIGURED;
+        USBLIB->state = USB_CONFIGURED;
     }
 }
 
 void usbSetDeviceAddress(void) {
-    bDeviceState = ADDRESSED;
+    USBLIB->state = USB_ADDRESSED;
 }
 
 /*
@@ -628,24 +651,6 @@ USER_STANDARD_REQUESTS User_Standard_Requests =
      NOP_Process,
      usbSetDeviceAddress};
 
-void (*pEpInt_IN[7])(void) =
-    {vcomDataTxCb,
-     vcomManagementCb,
-     NOP_Process,
-     NOP_Process,
-     NOP_Process,
-     NOP_Process,
-     NOP_Process};
-
-void (*pEpInt_OUT[7])(void) =
-    {NOP_Process,
-     NOP_Process,
-     vcomDataRxCb,
-     NOP_Process,
-     NOP_Process,
-     NOP_Process,
-     NOP_Process};
-
 /*
  * CDC ACM routines
  */
@@ -656,7 +661,7 @@ void usb_cdcacm_enable(gpio_dev *disc_dev, uint8 disc_bit) {
     gpio_write_bit(disc_dev, disc_bit, 0); // presents us to the host
 
     /* initialize USB peripheral */
-    usb_init_usblib(&Device_Property, &User_Standard_Requests);
+    usb_init_usblib(ep_int_in, ep_int_out);
 }
 
 void usb_cdcacm_disable(gpio_dev *disc_dev, uint8 disc_bit) {
diff --git a/libmaple/usb/usb_lib_globals.h b/libmaple/usb/usb_lib_globals.h
index 854cb12..a494817 100644
--- a/libmaple/usb/usb_lib_globals.h
+++ b/libmaple/usb/usb_lib_globals.h
@@ -34,19 +34,18 @@
 extern "C" {
 #endif
 
-extern void (*pEpInt_IN[7])(void);
-extern void (*pEpInt_OUT[7])(void);
-extern DEVICE_PROP Device_Property;
-extern USER_STANDARD_REQUESTS User_Standard_Requests;
-extern DEVICE  Device_Table;
-extern DEVICE_INFO Device_Info;
+extern USER_STANDARD_REQUESTS  User_Standard_Requests;
+extern USER_STANDARD_REQUESTS *pUser_Standard_Requests;
+
+extern DEVICE_PROP  Device_Property;
+extern DEVICE_PROP *pProperty;
+
+extern DEVICE_INFO  Device_Info;
+extern DEVICE_INFO *pInformation;
+
+extern DEVICE Device_Table;
 extern u16 SaveRState;
 extern u16 SaveTState;
-extern DEVICE_INFO* pInformation;
-extern DEVICE_PROP* pProperty;
-extern USER_STANDARD_REQUESTS *pUser_Standard_Requests;
-extern u16 SaveState ;
-extern u16 wInterrupt_Mask;
 
 #ifdef __cplusplus
 }