New 1-Wire bus implementation. 1-Wire controller is abstracted, though

only gpiobus configured via FDT is supported. Bus enumeration is
supported. Devices are created for each device found. 1-Wire
temperature controllers are supported, but other drivers could be
written. Temperatures are polled and reported via a sysctl.  Errors
are reported via sysctl counters. Mis-wired bus detection is included
for more trouble shooting. See ow(4), owc(4) and ow_temp(4) for
details of what's supported and known issues.

This has been tested on Raspberry Pi-B, Pi2 and Beagle Bone Black
with up to 7 devices.

Differential Revision: https://reviews.freebsd.org/D2956
Relnotes: yes
MFC after: 2 weeks
Reviewed by: loos@ (with many insightful comments)

1 files changed, 54 insertions, 0 deletions

diff --git a/sys/dev/ow/owll.h b/sys/dev/ow/owll.h
new file mode 100644
index 000000000000..ba2572a0b66e
--- /dev/null
+++ b/sys/dev/ow/owll.h
@@ -0,0 +1,54 @@
+/*-
+ * Copyright (c) 2015 M. Warner Losh <imp@freebsd.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice unmodified, this list of conditions, and the following
+ *    disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef DEV_OW_OWLL_H
+#define DEV_OW_OWLL_H 1
+
+/*
+ * Generalized parameters for the mode of operation in the bus. All units
+ * are in nanoseconds, and assume that all timings are < 4s.
+ * See owll_if.m for timings, and refer to AN937 for details.
+ */
+struct ow_timing 
+{
+	uint32_t	t_slot;		/* Slot time */
+	uint32_t	t_low0;		/* Time low for a 0 bit. */
+	uint32_t	t_low1;		/* Time low for a 1 bit. */
+	uint32_t	t_lowr;		/* Time slave holds line down per bit */
+	uint32_t	t_release;	/* Time after t_rdv to float high */
+	uint32_t	t_rec;		/* After sample before M low */
+	uint32_t	t_rdv;		/* Time to poll the bit after M low */
+	uint32_t	t_rstl;		/* Time M low on reset */
+	uint32_t	t_rsth;		/* Time M high on reset */
+	uint32_t	t_pdl;		/* Time S low on reset */
+	uint32_t	t_pdh;		/* Time R high after M low on reset */
+};
+
+#include "owll_if.h"
+
+#endif /* DEV_OW_OWLL_H */