[src/trunk]: src/usr.sbin/i2cscan i2cscan: support scans using only 1 byte reads

[tcort <tcort%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/c6ec3bb2b324
branches:  trunk
changeset: 787871:c6ec3bb2b324
user:      tcort <tcort%NetBSD.org@localhost>
date:      Wed Jul 10 15:18:54 2013 +0000

description:
i2cscan: support scans using only 1 byte reads

Add the '-r' option to scan using only 1 byte reads. This enhances
usability on i2c controllers, such as the am335x and dm37xx, that
don't support quick writes (0 byte writes). The default behaviour
remains unchanged.

Review and OK by jmcneill@

diffstat:

 usr.sbin/i2cscan/i2cscan.8 |  13 +++++++++--
 usr.sbin/i2cscan/i2cscan.c |  50 ++++++++++++++++++++++++++++++++++-----------
 2 files changed, 48 insertions(+), 15 deletions(-)

diffs (142 lines):

diff -r e5ea585900d5 -r c6ec3bb2b324 usr.sbin/i2cscan/i2cscan.8
--- a/usr.sbin/i2cscan/i2cscan.8        Wed Jul 10 15:10:56 2013 +0000
+++ b/usr.sbin/i2cscan/i2cscan.8        Wed Jul 10 15:18:54 2013 +0000
@@ -1,6 +1,6 @@
-.\"    $NetBSD: i2cscan.8,v 1.2 2012/02/04 18:25:53 pgoyette Exp $
+.\"    $NetBSD: i2cscan.8,v 1.3 2013/07/10 15:18:54 tcort Exp $
 .\"
-.\" Copyright (c) 2011 The NetBSD Foundation, Inc.
+.\" Copyright (c) 2011, 2013 The NetBSD Foundation, Inc.
 .\" All rights reserved.
 .\"
 .\" This code is derived from software contributed to The NetBSD Foundation
@@ -27,7 +27,7 @@
 .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 .\" POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd October 6, 2011
+.Dd July 10, 2013
 .Dt I2CSCAN 8
 .Os
 .Sh NAME
@@ -35,6 +35,7 @@
 .Nd scan an IIC bus for devices
 .Sh SYNOPSIS
 .Nm
+.Op Fl r
 .Ar i2cdev
 .Sh DESCRIPTION
 The
@@ -45,6 +46,12 @@
 .Ar i2cdev
 to determine which addresses respond.
 .Pp
+Available options:
+.Bl -tag -width Ds
+.It Fl r
+scan using 1 byte reads instead of quick writes.
+.El
+.Pp
 .Em WARNING !
 Using this utility can access some devices in such a
 manner as to leave them in an unstable or unusable state.
diff -r e5ea585900d5 -r c6ec3bb2b324 usr.sbin/i2cscan/i2cscan.c
--- a/usr.sbin/i2cscan/i2cscan.c        Wed Jul 10 15:10:56 2013 +0000
+++ b/usr.sbin/i2cscan/i2cscan.c        Wed Jul 10 15:18:54 2013 +0000
@@ -1,7 +1,7 @@
-/* $NetBSD: i2cscan.c,v 1.3 2011/11/01 22:30:32 pgoyette Exp $ */
+/* $NetBSD: i2cscan.c,v 1.4 2013/07/10 15:18:54 tcort Exp $ */
 
 /*-
- * Copyright (c) 2011 The NetBSD Foundation, Inc.
+ * Copyright (c) 2011, 2013 The NetBSD Foundation, Inc.
  * All rights reserved.
  *
  * This code is derived from software contributed to The NetBSD Foundation
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: i2cscan.c,v 1.3 2011/11/01 22:30:32 pgoyette Exp $");
+__RCSID("$NetBSD: i2cscan.c,v 1.4 2013/07/10 15:18:54 tcort Exp $");
 
 #include <sys/types.h>
 #include <sys/ioctl.h>
@@ -44,10 +44,13 @@
 
 #include <dev/i2c/i2c_io.h>
 
+#define MODE_DEFAULT 0
+#define MODE_READ 1
+
 __dead static void
-usage(const char *pn)
+usage(void)
 {
-       fprintf(stderr, "usage: %s <i2cdev>\n", pn);
+       fprintf(stderr, "usage: %s [-r] <i2cdev>\n", getprogname());
        exit(EXIT_FAILURE);
 }
 
@@ -87,7 +90,7 @@
 }
 
 static void
-do_i2c_scan(const char *dname, int fd)
+do_i2c_scan(const char *dname, int fd, int mode)
 {
        int error;
        int found = 0;
@@ -133,7 +136,8 @@
                printf("\r%s: scanning 0x%02x", dname, addr);
                fflush(stdout);
                if ((addr & 0xf8) == 0x30 ||
-                   (addr & 0xf0) == 0x50)
+                   (addr & 0xf0) == 0x50 ||
+                   mode == MODE_READ)
                        error = iic_smbus_receive_byte(fd, addr, &val, 0);
                else
                        error = iic_smbus_quick_write(fd, addr, 0);
@@ -153,15 +157,37 @@
 main(int argc, char *argv[])
 {
        int fd;
+       int ch, rflag;
+       int mode;
 
-       if (argc != 2)
-               usage(argv[0]);
+       setprogname(*argv);
+
+       rflag = 0;
 
-       fd = open(argv[1], O_RDWR);
+       while ((ch = getopt(argc, argv, "r")) != -1)
+               switch (ch) {
+               case 'r':
+                       rflag = 1;
+                       break;
+               default:
+                       break;
+               }
+       argv += optind;
+       argc -= optind;
+
+       if (rflag)
+               mode = MODE_READ;
+       else
+               mode = MODE_DEFAULT;
+
+       if (*argv == NULL)
+               usage();
+
+       fd = open(*argv, O_RDWR);
        if (fd == -1)
-               err(EXIT_FAILURE, "couldn't open %s", argv[1]);
+               err(EXIT_FAILURE, "couldn't open %s", *argv);
 
-       do_i2c_scan(argv[1], fd);
+       do_i2c_scan(*argv, fd, mode);
 
        close(fd);