From 21ff5c1d5328255e1a727720705c77a438bb95aa Mon Sep 17 00:00:00 2001
From: redoste <redoste@redoste.xyz>
Date: Sat, 27 May 2023 18:52:05 +0200
Subject: [PATCH] usb: expose the context of the interrupted function on USB
 interrupt

---
 include/gint/usb.h |  8 ++++++++
 src/usb/usb.c      | 12 +++++++++---
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/include/gint/usb.h b/include/gint/usb.h
index 479d28d..e727bfe 100644
--- a/include/gint/usb.h
+++ b/include/gint/usb.h
@@ -517,6 +517,14 @@ uint16_t usb_dc_string(uint16_t const *literal, size_t len);
    This is mostly used by the driver to answer GET_DESCRIPTOR requests. */
 usb_dc_string_t *usb_dc_string_get(uint16_t id);
 
+//---
+// USB interrupts
+//---
+
+/* usb_interrupt_context: Context of the function interrupted by a USB interrupt
+   The pointer is set back to NULL when the interrupt is finished being handled. */
+extern gint_inth_callback_context_t* usb_interrupt_context;
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/usb/usb.c b/src/usb/usb.c
index 14adb76..3d065b0 100644
--- a/src/usb/usb.c
+++ b/src/usb/usb.c
@@ -12,7 +12,7 @@
 
 #define USB SH7305_USB
 
-static void usb_interrupt_handler(void);
+static void usb_interrupt_handler(gint_inth_callback_context_t* interrupt_context);
 
 /* Shorthand to clear a bit in INTSTS0 */
 #define INTSTS0_clear(field_name) {				\
@@ -213,7 +213,7 @@ int usb_open(usb_interface_t const **interfaces, gint_call_t callback)
 	USB.NRDYSTS = 0x0000;
 	USB.BEMPSTS = 0x0000;
 
-	intc_handler_function(0xa20, GINT_CALL(usb_interrupt_handler));
+	intc_handler_function(0xa20, GINT_CALL_FLAG(usb_interrupt_handler));
 	intc_priority(INTC_USB, 8);
 
 	/* Pull D+ up to 3.3V, notifying connection when possible. Read
@@ -251,8 +251,12 @@ void usb_close(void)
 // Userspace interrupt handler
 //---
 
-static void usb_interrupt_handler(void)
+gint_inth_callback_context_t* usb_interrupt_context;
+
+static void usb_interrupt_handler(gint_inth_callback_context_t* interrupt_context)
 {
+	usb_interrupt_context = interrupt_context;
+
 	GUNUSED static char const * const device_st[] = {
 		"powered", "default", "address", "configured",
 		"suspended-powered", "suspended-default", "suspended-address",
@@ -315,6 +319,8 @@ static void usb_interrupt_handler(void)
 
 	/* Restore PIPESEL which can have been used for transfers */
 	USB.PIPESEL.word = pipesel;
+
+	usb_interrupt_context = NULL;
 }
 
 //---