shithub: util

Download patch

ref: 64d934dd3248b39915c703630a07396885604a36
parent: db1281e257bbe741e3e678b7e5c63c301d4b1696
author: glenda <glenda>
date: Wed Oct 1 21:50:26 EDT 2025 

lsm303dlhc i²c chip


--- /dev/null
+++ b/lsm303dlhc.c
@@ -1,0 +1,243 @@
+#include <u.h>
+#include <libc.h>
+#include <fcall.h>
+#include <thread.h>
+#include <9p.h>
+
+#define DATA "%s/i2c.%x.data"
+#define CTL "%s/i2c.%x.ctl"
+
+char *i2cdir = "/dev/i2c1";
+
+enum {
+	AccelAddr=	0x19,
+		CtrlReg1=		0x20,
+		CtrlReg2=		0x21,
+		CtrlReg3=		0x22,
+		CtrlReg4=		0x23,
+		CtrlReg5=		0x24,
+		CtrlReg6=		0x25,
+		FifoCtrlReg=	0x2E,
+		StatusReg=		0x27,
+		Int1Cfg=		0x30,
+		Int2Cfg=		0x34,
+			AccelXHigh=		0x29,
+			AccelXLow=		0x28,
+			AccelYHigh=		0x2B,
+			AccelYLow=		0x2A,
+			AccelZHigh=		0x2D,
+			AccelZLow=		0x2C,
+	MagnetAddr=	0x1e,
+		CraReg=		0x00,
+		CrbReg=		0x01,
+		MrReg=		0x02,
+		IraReg=		0x0A,
+		IrbReg=		0x0B,
+		IrcReg=		0x0C,
+			MagnetXHigh=	0x03,
+			MagnetXLow=		0x04,
+			MagnetYHigh=	0x05,
+			MagnetYLow=		0x06,
+			MagnetZHigh=	0x07,
+			MagnetZLow=		0x08,
+			TempHigh=		0x31,
+			TempLow=		0x32,
+	Ok=		0x00,
+	Err=	0xFF,
+};
+
+void
+ewrite(char *fname, char *buf, int n)
+{
+	int fd;
+
+	fd = open(fname, OWRITE);
+	if (fd == -1)
+		sysfatal("open: %r");
+
+	if (write(fd, buf, n) != n)
+		sysfatal("write: %r");
+
+	close(fd);
+}
+
+void
+eread(char *fname, char *reg, int r, char *buf, int n)
+{
+	int fd;
+
+	fd = open(fname, ORDWR);
+	if (fd == -1)
+		sysfatal("open: %r");
+
+	if (write(fd, reg, r) != r)
+		sysfatal("write: %r");
+
+	if (read(fd, buf, n) != n)
+		sysfatal("read: %r");
+
+	close(fd);
+}
+
+void
+fsread(Req *r)
+{
+	char *data;
+	char reg[1];
+	char out[1];
+	short x, y, z;
+
+	switch ((intptr)(r->fid->file->aux)) {
+	case 1:
+		data = smprint(DATA, i2cdir, AccelAddr);
+		if (data == nil)
+			sysfatal("smprint: %r");
+
+		reg[0] = AccelXHigh;
+		eread(data, reg, 1, out, 1);
+		x = out[0] << 8;
+		reg[0] = AccelXLow;
+		eread(data, reg, 1, out, 1);
+		x |= out[0];
+
+		reg[0] = AccelYHigh;
+		eread(data, reg, 1, out, 1);
+		y = out[0] << 8;
+		reg[0] = AccelYLow;
+		eread(data, reg, 1, out, 1);
+		y |= out[0];
+
+		reg[0] = AccelZHigh;
+		eread(data, reg, 1, out, 1);
+		z = out[0] << 8;
+		reg[0] = AccelZLow;
+		eread(data, reg, 1, out, 1);
+		z |= out[0];
+
+		free(data);
+
+		data = smprint("%11d %11d %11d\n", x, y, z);
+		if (data == nil)
+			sysfatal("smprint: %r");
+
+		readstr(r, data);
+		respond(r, nil);
+
+		free(data);
+		break;
+	case 2:
+		data = smprint(DATA, i2cdir, MagnetAddr);
+		if (data == nil)
+			sysfatal("smprint: %r");
+
+		reg[0] = MagnetXHigh;
+		eread(data, reg, 1, out, 1);
+		x = out[0] << 8;
+		reg[0] = MagnetXLow;
+		eread(data, reg, 1, out, 1);
+		x |= out[0];
+
+		reg[0] = MagnetYHigh;
+		eread(data, reg, 1, out, 1);
+		y = out[0] << 8;
+		reg[0] = MagnetYLow;
+		eread(data, reg, 1, out, 1);
+		y |= out[0];
+
+		reg[0] = MagnetZHigh;
+		eread(data, reg, 1, out, 1);
+		z = out[0] << 8;
+		reg[0] = MagnetZLow;
+		eread(data, reg, 1, out, 1);
+		z |= out[0];
+
+		free(data);
+
+		data = smprint("%11d %11d %11d\n", x, y, z);
+		if (data == nil)
+			sysfatal("smprint: %r");
+
+		readstr(r, data);
+		respond(r, nil);
+
+		free(data);
+		break;
+	default:
+		respond(r, "error");
+		break;
+	}
+}
+
+Srv fs = {
+.read	= fsread,
+};
+
+void
+init(void)
+{
+	char *data;
+	char buf[2];
+
+	data = smprint(DATA, i2cdir, AccelAddr);
+	if (data == nil)
+		sysfatal("smprint: %r");
+
+	buf[0] = CtrlReg1;
+	buf[1] = 0x27;
+	ewrite(data, buf, 2);
+
+	buf[0] = CtrlReg4;
+	buf[1] = 0x40;
+	ewrite(data, buf, 2);
+
+	buf[0] = CtrlReg5;
+	buf[1] = 0x40;
+	ewrite(data, buf, 2);
+
+	buf[0] = FifoCtrlReg;
+	buf[1] = 0x80;
+	ewrite(data, buf, 2);
+
+	free(data);
+
+	data = smprint(DATA, i2cdir, MagnetAddr);
+	if (data == nil)
+		sysfatal("smprint: %r");
+
+	buf[0] = CraReg;
+	buf[1] = 0x9C;
+	ewrite(data, buf, 2);
+
+	buf[0] = CrbReg;
+	buf[1] = 0x20;
+	ewrite(data, buf, 2);
+
+	buf[0] = MrReg;
+	buf[1] = 0x00;
+	ewrite(data, buf, 2);
+
+	buf[0] = IraReg;
+	buf[1] = 0x48;
+	ewrite(data, buf, 2);
+
+	buf[0] = IrbReg;
+	buf[1] = 0x34;
+	ewrite(data, buf, 2);
+
+	buf[0] = IrcReg;
+	buf[1] = 0x33;
+	ewrite(data, buf, 2);
+
+	free(data);
+}
+
+void
+main()
+{
+	init();
+
+	fs.tree = alloctree("lsm303dlhc", "lsm303dlhc", DMDIR|0555, nil);
+	createfile(fs.tree->root, "accel", "lsm303dlhc", 0444, (void*)1);
+	createfile(fs.tree->root, "compass", "lsm303dlhc", 0444, (void*)2);
+	postmountsrv(&fs, "lsm303dlhc", "/dev", MBEFORE);
+}
-- 
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