From cf2b86deaa15f9d8ebf420a2e2f48b5922ffaf68 Mon Sep 17 00:00:00 2001
From: Lephe <sebastien.michelland@protonmail.com>
Date: Sat, 28 Jan 2023 13:09:15 +0100
Subject: [PATCH] usb: update module details with register analysis experiments

Unknown writable bits and host-only registers were found.
---
 include/gint/mpu/usb.h | 53 +++++++++++++++++++++++++++++++++++-------
 src/usb/usb.c          | 20 +++++++++++++++-
 2 files changed, 63 insertions(+), 10 deletions(-)

diff --git a/include/gint/mpu/usb.h b/include/gint/mpu/usb.h
index 5cbf5bc..c4206a4 100644
--- a/include/gint/mpu/usb.h
+++ b/include/gint/mpu/usb.h
@@ -28,12 +28,16 @@ typedef volatile struct
 
 	/* CPU Bus Wait Setting Register */
 	word_union(BUSWAIT,
-		uint16_t	:12;
+		uint16_t	:8;
+		uint16_t _1	:1;	/* Unknown role; can be set */
+		uint16_t	:1;
+		uint16_t _2	:1;	/* Unknown role; can be set */
+		uint16_t	:1;
 		uint16_t BWAIT	:4;	/* Bus Wait */
 	);
 
 	/* System Configuration Status Register */
-	word_union(SYSSTS,
+	const word_union(SYSSTS,
 		uint16_t	:14;
 		uint16_t LNST	:2;	/* Line Status */
 	);
@@ -41,7 +45,9 @@ typedef volatile struct
 
 	/* Device State Control Register */
 	word_union(DVSTCTR,
-		uint16_t	:7;
+		uint16_t _1	:1;	/* Unknown role; can be set */
+		uint16_t	:2;
+		uint16_t _2	:4;	/* Unknown role; can be set */
 		uint16_t WKUP	:1;	/* Wakeup Output */
 		uint16_t RWUPE	:1;	/* Wakeup Detection Enable */
 		uint16_t USBRT	:1;	/* USB Reset Output */
@@ -92,8 +98,9 @@ typedef volatile struct
 		uint16_t DREQE	:1;	/* DMA Transfert Request Enable */
 		uint16_t MBW	:2;	/* Access Bits Width */
 		uint16_t	:1;
-		uint16_t BIGEND	:1;	/* Endiant Control */
-		uint16_t	:4;
+		uint16_t BIGEND	:1;	/* Endian Control */
+		uint16_t _1	:1;	/* Unknown role; can be set */
+		uint16_t	:3;
 		uint16_t CURPIPE:4;	/* Port Access Pipe Specification */
 	);
 	word_union(D0FIFOCTR,
@@ -111,7 +118,8 @@ typedef volatile struct
 		uint16_t MBW	:2;	/* Access Bits Width */
 		uint16_t	:1;
 		uint16_t BIGEND	:1;	/* Endian Control */
-		uint16_t	:4;
+		uint16_t _1	:1;	/* Unknown role; can be set */
+		uint16_t	:3;
 		uint16_t CURPIPE:4;	/* Port Access Pipe Specification */
 	);
 	word_union(D1FIFOCTR,
@@ -134,7 +142,19 @@ typedef volatile struct
 		uint16_t BRDYE	:1;	/* Buffer Ready */
 		uint16_t	:8;
 	);
-	pad(4);
+	word_union(INTENB1,
+		uint16_t _1	:1;	/* Unknown role; can be set */
+		uint16_t BCHGE	:1;	/* Bus Change */
+		uint16_t	:1;
+		uint16_t DTCHE	:1;	/* Disconnection Detection */
+		uint16_t ATTCHE	:1;	/* Connection Detection */
+		uint16_t	:4;
+		uint16_t EOFERRE:1;	/* EOF Error Detection */
+		uint16_t SIGNE	:1;	/* Setup Transaction Error */
+		uint16_t SACKE	:1;	/* Setup Transaction Normal Response */
+		uint16_t	:4;
+	);
+	pad(2);
 
 	/* BRDY Interrupt Enable Register */
 	uint16_t BRDYENB;
@@ -150,7 +170,10 @@ typedef volatile struct
 		uint16_t	:1;
 		uint16_t BRDYM	:1;	/* BRDY Status Clear Timing */
 		uint16_t enable	:1; 	/* SHOULD BE SET TO 1 MANUALLY */
-		uint16_t	:5;
+		uint16_t	:1;
+		uint16_t _1	:1;	/* Unknown role; can be set */
+		uint16_t _2	:1;	/* Unknown role; can be set */
+		uint16_t	:2;
 	);
 	pad(2);
 
@@ -217,7 +240,10 @@ typedef volatile struct
 
 	/* DCP Configuration Register */
 	word_union(DCPCFG,
-		uint16_t	:11;
+		uint16_t	:7;
+		uint16_t _1	:1;	/* Unknown role; can be set */
+		uint16_t _2	:1;	/* Unknown role; can be set */
+		uint16_t	:2;
 		uint16_t DIR	:1;	/* Transfer Direction */
 		uint16_t	:4;
 	);
@@ -357,6 +383,15 @@ typedef volatile struct
 	pad(0x1e);
 
 	uint16_t REG_C2;
+	pad(12);
+
+	word_union(DEVADD[11],
+		uint16_t	:1;
+		uint16_t UPPHUB	:4;	/* Address of target's hub */
+		uint16_t HUBPORT:3;	/* Hub port where target connects */
+		uint16_t USBSPD	:2;	/* Transfer speed / Target present */
+		uint16_t	:6;
+	);
 
 } GPACKED(4) sh7305_usb_t;
 
diff --git a/src/usb/usb.c b/src/usb/usb.c
index 405ab04..c0b1699 100644
--- a/src/usb/usb.c
+++ b/src/usb/usb.c
@@ -141,9 +141,27 @@ int usb_open(usb_interface_t const **interfaces, gint_call_t callback)
 	if(!hpowered()) hpoweron();
 	hpoweron_write();
 
-	*(uint16_t volatile *)0xa4d800c2 = 0x0020;
+	USB.REG_C2 = 0x0020;
+
+	// TODO: Configuration sequence
+	// - DPRPU = 0     (disconnect if previously a function)
+	// - DPRD = 0      (required for setting DCFM)
+	// - DCFM = 0/1    (select host/function)
+	// - USBE = 0      (clears registers based on DCFM)
+	// Then for function:
+	// - HSE = 1       (use high-speed)
+	// - USBE = 1
+	// - ...
+	// - DPRPU = 1     (notify host of connection)
+	// - Read LNST
+	// And for host:
+	// - HSE = 0       (allow slow devices)
+	// - USBE = 1
+	// - DRPD = 1      (host setting)
+	// - Read LNST
 
 	/* Turn on the module now that SCKE=1 */
+	// TODO: Set to 0 now, set to 1 after enabling DPRPU/DPRD
 	USB.SYSCFG.USBE = 1;
 	USB.SYSCFG.HSE = 1;