20060303

1 files changed, 75 insertions, 0 deletions

diff --git a/os/manga/gpio.c b/os/manga/gpio.c
new file mode 100644
index 00000000..c6d0179d
--- /dev/null
+++ b/os/manga/gpio.c
@@ -0,0 +1,75 @@
+#include	"u.h"
+#include 	"mem.h"
+#include	"../port/lib.h"
+#include 	"dat.h"
+#include	"fns.h"
+#include	"io.h"
+
+static ulong gpioreserved;
+static Lock gpiolock;
+
+void
+gpioreserve(int n)
+{
+	ulong mask;
+
+	mask = 1<<n;
+	ilock(&gpiolock);
+	if(gpioreserved & mask)
+		panic("gpioreserve: duplicate use of GPIO %d", n);
+	gpioreserved |= mask;
+	iunlock(&gpiolock);
+}
+
+/*
+ * set direction and alternative function bits in the GPIO control register,
+ * following the configuration bits in cfg.
+ */
+void
+gpioconfig(int n, ulong cfg)
+{
+	GpioReg *g;
+
+	ilock(&gpiolock);
+	g = GPIOREG;
+	if(cfg & Gpio_out)
+		g->iopm |= 1<<n;
+	else
+		g->iopm &= ~(1<<n);
+	iunlock(&gpiolock);
+}
+
+ulong
+gpioget(int n)
+{
+	return GPIOREG->iopd & (1<<n);
+}
+
+void
+gpioset(int n, int v)
+{
+	GpioReg *g;
+	ulong mask;
+
+	mask = 1<<n;
+	ilock(&gpiolock);
+	g = GPIOREG;
+	if(v)
+		g->iopd |= mask;
+	else
+		g->iopd &= ~mask;
+	iunlock(&gpiolock);
+}
+
+void
+gpiorelease(int n)
+{
+	ulong mask;
+
+	mask = 1<<n;
+	ilock(&gpiolock);
+	if((gpioreserved & mask) != mask)
+		panic("gpiorelease: unexpected release of GPIO %d", n);
+	gpioreserved &= ~mask;
+	iunlock(&gpiolock);
+}