From 74a4d8c26dd3c1e9febcb717cfd6cb6512991a7a Mon Sep 17 00:00:00 2001
From: "Charles.Forsyth" <devnull@localhost>
Date: Fri, 22 Dec 2006 21:39:35 +0000
Subject: 20060303

---
 os/port/devi2c.c | 227 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 227 insertions(+)
 create mode 100644 os/port/devi2c.c

(limited to 'os/port/devi2c.c')

diff --git a/os/port/devi2c.c b/os/port/devi2c.c
new file mode 100644
index 00000000..50512248
--- /dev/null
+++ b/os/port/devi2c.c
@@ -0,0 +1,227 @@
+/*
+ * i2c
+ *
+ * Copyright © 1998, 2003 Vita Nuova Limited.
+ */
+
+#include "u.h"
+#include "../port/lib.h"
+#include "mem.h"
+#include "dat.h"
+#include "fns.h"
+#include "io.h"
+#include "../port/error.h"
+
+typedef struct I2Cdir I2Cdir;
+
+enum{
+	Qdir,
+	Qdata,
+	Qctl,
+};
+
+static
+Dirtab i2ctab[]={
+	".",	{Qdir, 0, QTDIR},	0,	0555,
+	"i2cdata",		{Qdata, 0},	256,	0660,
+	"i2cctl",		{Qctl, 0},		0,	0660,
+};
+
+struct I2Cdir {
+	Ref;
+	I2Cdev;
+	Dirtab	tab[nelem(i2ctab)];
+};
+
+static void
+i2creset(void)
+{
+	i2csetup(0);
+}
+
+static Chan*
+i2cattach(char* spec)
+{
+	char *s;
+	ulong addr;
+	I2Cdir *d;
+	Chan *c;
+
+	addr = strtoul(spec, &s, 16);
+	if(*spec == 0 || *s || addr >= (1<<10))
+		error("invalid i2c address");
+	d = malloc(sizeof(I2Cdir));
+	if(d == nil)
+		error(Enomem);
+	d->ref = 1;
+	d->addr = addr;
+	d->salen = 0;
+	d->tenbit = addr >= 128;
+	memmove(d->tab, i2ctab, sizeof(d->tab));
+	sprint(d->tab[1].name, "i2c.%lux.data", addr);
+	sprint(d->tab[2].name, "i2c.%lux.ctl", addr);
+
+	c = devattach('J', spec);
+	c->aux = d;
+	return c;
+}
+
+static Walkqid*
+i2cwalk(Chan* c, Chan *nc, char **name, int nname)
+{
+	Walkqid *wq;
+	I2Cdir *d;
+
+	d = c->aux;
+	wq = devwalk(c, nc, name, nname, d->tab, nelem(d->tab), devgen);
+	if(wq != nil && wq->clone != nil && wq->clone != c)
+		incref(d);
+	return wq;
+}
+
+static int
+i2cstat(Chan* c, uchar *dp, int n)
+{
+	I2Cdir *d;
+
+	d = c->aux;
+	return devstat(c, dp, n, d->tab, nelem(d->tab), devgen);
+}
+
+static Chan*
+i2copen(Chan* c, int omode)
+{
+	I2Cdir *d;
+
+	d = c->aux;
+	return devopen(c, omode, d->tab, nelem(d->tab), devgen);
+}
+
+static void
+i2cclose(Chan *c)
+{
+	I2Cdir *d;
+
+	d = c->aux;
+	if(decref(d) == 0)
+		free(d);
+}
+
+static long
+i2cread(Chan *c, void *a, long n, vlong offset)
+{
+	I2Cdir *d;
+	char *s, *e;
+	ulong len;
+
+	d = c->aux;
+	switch((ulong)c->qid.path){
+	case Qdir:
+		return devdirread(c, a, n, d->tab, nelem(d->tab), devgen);
+	case Qdata:
+		len = d->tab[1].length;
+		if(offset+n >= len){
+			n = len - offset;
+			if(n <= 0)
+				return 0;
+		}
+		n = i2crecv(d, a, n, offset);
+		break;
+	case Qctl:
+		s = smalloc(READSTR);
+		if(waserror()){
+			free(s);
+			nexterror();
+		}
+		e = seprint(s, s+READSTR, "size %lud\n", (ulong)d->tab[1].length);
+		if(d->salen)
+			e = seprint(e, s+READSTR, "subaddress %d\n", d->salen);
+		if(d->tenbit)
+			seprint(e, s+READSTR, "a10\n");
+		n = readstr(offset, a, n, s);
+		poperror();
+		free(s);
+		return n;
+	default:
+		n=0;
+		break;
+	}
+	return n;
+}
+
+static long
+i2cwrite(Chan *c, void *a, long n, vlong offset)
+{
+	I2Cdir *d;
+	long len;
+	Cmdbuf *cb;
+
+	USED(offset);
+	switch((ulong)c->qid.path){
+	case Qdata:
+		d = c->aux;
+		len = d->tab[1].length;
+		if(offset+n >= len){
+			n = len - offset;
+			if(n <= 0)
+				return 0;
+		}
+		n = i2csend(d, a, n, offset);
+		break;
+	case Qctl:
+		cb = parsecmd(a, n);
+		if(waserror()){
+			free(cb);
+			nexterror();
+		}
+		if(cb->nf < 1)
+			error(Ebadctl);
+		d = c->aux;
+		if(strcmp(cb->f[0], "subaddress") == 0){
+			if(cb->nf > 1){
+				len = strtol(cb->f[1], nil, 0);
+				if(len <= 0)
+					len = 0;
+				if(len > 4)
+					cmderror(cb, "subaddress too long");
+			}else
+				len = 1;
+			d->salen = len;
+		}else if(cb->nf > 1 && strcmp(cb->f[0], "size") == 0){
+			len = strtol(cb->f[1], nil, 0);
+			if(len < 0)
+				cmderror(cb, "size is negative");
+			d->tab[1].length = len;
+		}else if(strcmp(cb->f[0], "a10") == 0)
+			d->tenbit = 1;
+		else
+			cmderror(cb, "unknown control request");
+		poperror();
+		free(cb);
+		break;
+	default:
+		error(Ebadusefd);
+	}
+	return n;
+}
+
+Dev i2cdevtab = {
+	'J',
+	"i2c",
+
+	i2creset,
+	devinit,
+	devshutdown,
+	i2cattach,
+	i2cwalk,
+	i2cstat,
+	i2copen,
+	devcreate,
+	i2cclose,
+	i2cread,
+	devbread,
+	i2cwrite,
+	devbwrite,
+	devremove,
+	devwstat,
+};
-- 
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