From 055a10f826b3596ad5458be326bc2f84c7a50987 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Sat, 28 Apr 2001 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 2001-04-28

---
 bitsy/devuda1341.c | 37 ++++++++++++++-----------------------
 pc/devvga.c        | 12 +++++++-----
 pc/i8259.c         | 10 ----------
 pc/screen.h        |  1 +
 4 files changed, 22 insertions(+), 38 deletions(-)

diff --git a/bitsy/devuda1341.c b/bitsy/devuda1341.c
index fc3639ba64a239b265fff609ff26207282c003f0..717a8a090176f31c9b5b78f55fc3ff1add4d1389 100644
--- a/bitsy/devuda1341.c
+++ b/bitsy/devuda1341.c
@@ -44,13 +44,15 @@ static int debug = 0;
  * L3 setup and hold times (expressed in µs)
  */
 enum {
-	L3_DataSetupTime =	1,	/* 190 ns */
-	L3_DataHoldTime =		1,	/*  30 ns */
-	L3_ModeSetupTime =	1,	/* 190 ns */
-	L3_ModeHoldTime =	1,	/* 190 ns */
-	L3_ClockHighTime =	1,	/* 100 ns */
-	L3_ClockLowTime =		1,	/* 100 ns */
-	L3_HaltTime =			1,	/* 190 ns */
+	L3_AcquireTime =		1,
+	L3_ReleaseTime =		1,
+	L3_DataSetupTime =	(190+999)/1000,	/* 190 ns */
+	L3_DataHoldTime =		( 30+999)/1000,
+	L3_ModeSetupTime =	(190+999)/1000,
+	L3_ModeHoldTime =	(190+999)/1000,
+	L3_ClockHighTime =	(100+999)/1000,
+	L3_ClockLowTime =		(100+999)/1000,
+	L3_HaltTime =			(190+999)/1000,
 };
 
 /* UDA 1341 Registers */
@@ -199,9 +201,9 @@ static void	setreg(char *name, int val, int n);
 static void
 L3_acquirepins(void)
 {
-	gpioregs->set = (GPIO_L3_SCLK_o | GPIO_L3_SDA_io);
-	gpioregs->direction |=  (GPIO_L3_SCLK_o | GPIO_L3_SDA_io);
-	µdelay(2);
+	gpioregs->set = (GPIO_L3_MODE_o | GPIO_L3_SCLK_o | GPIO_L3_SDA_io);
+	gpioregs->direction |=  (GPIO_L3_MODE_o | GPIO_L3_SCLK_o | GPIO_L3_SDA_io);
+	µdelay(L3_AcquireTime);
 }
 
 /*
@@ -210,7 +212,8 @@ L3_acquirepins(void)
 static void
 L3_releasepins(void)
 {
-	gpioregs->direction &= ~(GPIO_L3_SCLK_o | GPIO_L3_SDA_io);
+	gpioregs->direction &= ~(GPIO_L3_MODE_o | GPIO_L3_SCLK_o | GPIO_L3_SDA_io);
+	µdelay(L3_ReleaseTime);
 }
 
 /*
@@ -220,8 +223,6 @@ static void
 L3_init(void)
 {
 	gpioregs->altfunc &= ~(GPIO_L3_SDA_io | GPIO_L3_SCLK_o | GPIO_L3_MODE_o);
-	gpioregs->set = GPIO_L3_MODE_o;
-	gpioregs->direction |= GPIO_L3_MODE_o;
 	L3_releasepins();
 }
 
@@ -276,8 +277,6 @@ L3_sendbyte(char data, int mode)
 {
 	int i;
 
-//suspect	L3_acquirepins();
-
 	switch(mode) {
 	case 0: /* Address mode */
 		gpioregs->clear = GPIO_L3_MODE_o;
@@ -296,14 +295,10 @@ L3_sendbyte(char data, int mode)
 	for (i = 0; i < 8; i++)
 		L3_sendbit(data >> i);
 
-	µdelay(L3_ModeHoldTime);
-
 	if (mode == 0)  /* Address mode */
 		gpioregs->set = GPIO_L3_MODE_o;
 
 	µdelay(L3_ModeHoldTime);
-
-//suspect		L3_releasepins();
 }
 
 /*
@@ -319,8 +314,6 @@ L3_getbyte(int mode)
 	char data = 0;
 	int i;
 
-//suspect		L3_acquirepins();
-
 	switch(mode) {
 	case 0: /* Address mode - never valid */
 		break;
@@ -340,8 +333,6 @@ L3_getbyte(int mode)
 
 	µdelay(L3_ModeHoldTime);
 
-	L3_releasepins();
-
 	return data;
 }
 
diff --git a/pc/devvga.c b/pc/devvga.c
index 2522a90637cde52310e19012141ea6163d76c0e7..bc95e2c7411584016ab3535e3cea7c9fae737d02 100644
--- a/pc/devvga.c
+++ b/pc/devvga.c
@@ -61,7 +61,6 @@ vgastat(Chan* c, char* dp)
 static Chan*
 vgaopen(Chan* c, int omode)
 {
-	pprint("vgaopen: pid %d, %d %p\n", up->pid, c->ref, c);
 	return devopen(c, omode, vgadir, nelem(vgadir), devgen);
 }
 
@@ -73,8 +72,8 @@ vgaclose(Chan*c)
 	pprint("vgaclose: pid %d, %d, %p\n", up->pid, c->ref, c);
 	scr = &vgascreen[0];
 	if (scr && scr->dev && scr->dev->ovlctl) {
-		static char *disable = "disable\n";
-		pprint("vgaclose: Calling ovlctl (%p) %p\n", scr->dev->ovlctl, disable);
+		static char disable[] = "disable\n"; 
+
 		scr->dev->ovlctl(scr, disable, strlen(disable));
 	}
 }
@@ -387,8 +386,11 @@ vgawrite(Chan* c, void* a, long n, vlong off)
 
 	case Qvgaovl:
 		scr = &vgascreen[0];
-		pprint("vgawrite: Qvgaovl %d (%s)\n", Qvgaovl, scr->dev->name);
-		return 0;
+		if (scr->dev->ovlwrite == nil) {
+			error(Enooverlay);
+			break;
+		}
+		return scr->dev->ovlwrite(scr, a, n, off);
 
 	case Qvgaovlctl:
 		scr = &vgascreen[0];
diff --git a/pc/i8259.c b/pc/i8259.c
index b161c3a0b3e6de3297da6dc23ef07238823bdefd..ca87f1d9fe976a56a5ab5673fa712ac7620b6411 100644
--- a/pc/i8259.c
+++ b/pc/i8259.c
@@ -164,13 +164,3 @@ i8259enable(Vctl* v)
 
 	return VectorPIC+irq;
 }
-
-void
-i8259dump(void)
-{
-	uchar aux0, aux1;
-
-	aux0 = inb(Int0aux);
-	aux1 = inb(Int1aux);
-	print("i8269: %ux %2.2ux %2.2ux\n", i8259mask, aux0, aux1);
-}
diff --git a/pc/screen.h b/pc/screen.h
index 64c175e015bb12e696bb266fb7eb8782de4e808a..5aea5675b16a6ba7e1db93469bae25912c717686 100644
--- a/pc/screen.h
+++ b/pc/screen.h
@@ -69,6 +69,7 @@ struct VGAdev {
 	void	(*drawinit)(VGAscr*);
 	int	(*fill)(VGAscr*, Rectangle, ulong);
 	int	(*ovlctl)(VGAscr*, void*, int);
+	int	(*ovlwrite)(VGAscr*, void*, int, vlong);
 };
 
 struct VGAcur {