9os

commit 162747b94f638768178d38af33f1f609305dd581
parent e7a48f46c5b29472a2db41889bb4642f49045bf1
Author: Roberto Vargas <roberto.vargas@arm.com>
Date:   Thu, 28 Feb 2019 10:19:16 +0000

[dev] Add devwrite()

Only a few devs are going to support write, so it makes
sense to have a general function to disable writes. This
patch also makes the order of the parameters in bind()
more orthogonal with the driver prototype.

Change-Id: I675a7aa35408b5a4c9b01f1ed95c8706c696c46b

Diffstat:
M
drivers/dev.c
 | 
24
+++++++++++++++---------
M
drivers/dev.h
 | 
3
++-
M
drivers/devroot.c
 | 
10
++--------
M
drivers/devuart.c
 | 
1
+

4 files changed, 20 insertions(+), 18 deletions(-)
diff --git a/drivers/dev.c b/drivers/dev.c
@@ -334,6 +334,13 @@ write(int fd, void *buf, int n)
 }
 
 int
+devwrite(Chan *c, void *buf, int n)
+{
+	errno = EINVAL;
+	return -1;
+}
+
+int
 seek(int fd, long long off, int whence)
 {
 	Chan *c;
@@ -362,10 +369,16 @@ seek(int fd, long long off, int whence)
 }
 
 int
+devbind(Chan *new, Chan *where)
+{
+	errno = EINVAL;
+	return -1;
+}
+
+int
 bind(char *new, char *where)
 {
 	Chan *cw, *cn;
-	int (*fn)(Chan *, Chan *);
 
 	if ((cw = namec(where, O_READ)) == NULL)
 		goto err0;
@@ -378,15 +391,8 @@ bind(char *new, char *where)
 	if ((cn = namec(new, O_BIND)) == NULL)
 		goto err1;
 
-	fn = devtab[cw->type]->bind;
-	if (!fn) {
-		errno = EINVAL;
-		goto err2;
-	}
-
-	if ((*fn)(cw, cn) < 0)
+	if (devtab[cw->type]->bind(cn, cw) < 0)
 		goto err2;
-
 	chanclose(cw);
 
 	return 0;
diff --git a/drivers/dev.h b/drivers/dev.h
@@ -11,7 +11,6 @@ typedef struct chan Chan;
 typedef struct dirtab Dirtab;
 typedef int Devgen(Chan *, const Dirtab *, int, int, Dir *);
 typedef struct attr Attr;
-typedef struct uart Uart;
 
 struct dirtab {
 	char name[NAMELEN];
@@ -48,6 +47,8 @@ extern Chan *devclone(Chan *c, Chan *nc);
 extern Chan *devattach(int id, int dev);
 extern Chan *devclone(Chan *c, Chan *nc);
 extern void devlink(void);
+extern int devbind(Chan *new, Chan *where);
+extern int devwrite(Chan *c, void *buf, int n);
 extern void chanclose(Chan *c);
 extern int devgen(Chan *c,
                   const Dirtab *tab, int ntab,
diff --git a/drivers/devroot.c b/drivers/devroot.c
@@ -65,7 +65,7 @@ rootwalk(Chan *c, const char *name)
 }
 
 static int
-rootbind(Chan *cw, Chan *cn)
+rootbind(Chan *cn, Chan *cw)
 {
 	Qid qid;
 	Chan *mnt;
@@ -95,12 +95,6 @@ rootread(Chan *c, void *buf, int n)
 	return dirread(c, buf, n, NULL, 0, rootgen);
 }
 
-static int
-rootwrite(Chan *c, void *buf, int n)
-{
-	return -1;
-}
-
 const Dev rootdevtab = {
 	.id = '/',
 	.name = "root",
@@ -108,6 +102,6 @@ const Dev rootdevtab = {
 	.attach = rootattach,
 	.walk = rootwalk,
 	.read = rootread,
-	.write = rootwrite,
+	.write = devwrite,
 	.bind = rootbind,
 };
diff --git a/drivers/devuart.c b/drivers/devuart.c
@@ -289,4 +289,5 @@ const Dev uartdevtab = {
 	.clone = devclone,
 	.read = uartread,
 	.write = uartwrite,
+	.bind = devbind,
 };