bcm: import changes for raspi2/3 from richard miller

1 files changed, 142 insertions, 0 deletions

diff --git a/sys/src/9/bcm/gpio.c b/sys/src/9/bcm/gpio.c
new file mode 100644
index 000000000..b970e96f6
--- /dev/null
+++ b/sys/src/9/bcm/gpio.c
@@ -0,0 +1,142 @@
+/*
+ * Raspberry Pi GPIO support
+ */
+
+#include "u.h"
+#include "../port/lib.h"
+#include "../port/error.h"
+#include "mem.h"
+#include "dat.h"
+#include "fns.h"
+#include "io.h"
+
+#define GPIOREGS	(VIRTIO+0x200000)
+
+/* GPIO regs */
+enum {
+	Fsel0	= 0x00>>2,
+		FuncMask= 0x7,
+	Set0	= 0x1c>>2,
+	Clr0	= 0x28>>2,
+	Lev0	= 0x34>>2,
+	Evds0	= 0x40>>2,
+	Redge0	= 0x4C>>2,
+	Fedge0	= 0x58>>2,
+	Hpin0	= 0x64>>2,
+	Lpin0	= 0x70>>2,
+	ARedge0	= 0x7C>>2,
+	AFedge0	= 0x88>2,
+	PUD	= 0x94>>2,
+		Off	= 0x0,
+		Pulldown= 0x1,
+		Pullup	= 0x2,
+	PUDclk0	= 0x98>>2,
+	PUDclk1	= 0x9c>>2,
+};
+
+void
+gpiosel(uint pin, int func)
+{	
+	u32int *gp, *fsel;
+	int off;
+
+	gp = (u32int*)GPIOREGS;
+	fsel = &gp[Fsel0 + pin/10];
+	off = (pin % 10) * 3;
+	*fsel = (*fsel & ~(FuncMask<<off)) | func<<off;
+}
+
+void
+gpiopull(uint pin, int func)
+{
+	u32int *gp, *reg;
+	u32int mask;
+
+	gp = (u32int*)GPIOREGS;
+	reg = &gp[PUDclk0 + pin/32];
+	mask = 1 << (pin % 32);
+	gp[PUD] = func;
+	microdelay(1);
+	*reg = mask;
+	microdelay(1);
+	*reg = 0;
+}
+
+void
+gpiopulloff(uint pin)
+{
+	gpiopull(pin, Off);
+}
+
+void
+gpiopullup(uint pin)
+{
+	gpiopull(pin, Pullup);
+}
+
+void
+gpiopulldown(uint pin)
+{
+	gpiopull(pin, Pulldown);
+}
+
+void
+gpioout(uint pin, int set)
+{
+	u32int *gp;
+	int v;
+
+	gp = (u32int*)GPIOREGS;
+	v = set? Set0 : Clr0;
+	gp[v + pin/32] = 1 << (pin % 32);
+}
+
+int
+gpioin(uint pin)
+{
+	u32int *gp;
+
+	gp = (u32int*)GPIOREGS;
+	return (gp[Lev0 + pin/32] & (1 << (pin % 32))) != 0;
+}
+
+void
+gpioselevent(uint pin, int falling, int enable)
+{
+	u32int *gp, *field;
+	int reg;
+
+	enable = enable != 0;
+	if(falling)
+		reg = Fedge0;
+	else
+		reg = Redge0;
+	gp = (u32int*)GPIOREGS;
+	field = &gp[reg + pin/32];
+	*field = (*field & ~(enable<<pin)) | (enable<<pin);
+}
+
+int
+gpiogetevent(uint pin)
+{
+	u32int *gp, *reg, val;
+
+	gp = (u32int*)GPIOREGS;
+	reg = &gp[Evds0 + pin/32];
+	val = *reg & (1 << (pin % 32));
+	*reg |= val;
+	return val != 0;
+}
+
+void
+gpiomeminit(void)
+{
+	Physseg seg;
+
+	memset(&seg, 0, sizeof seg);
+	seg.attr = SG_PHYSICAL;
+	seg.name = "gpio";
+	seg.pa = GPIOREGS;
+	seg.size = BY2PG;
+	addphysseg(&seg);
+}