From NetBSD: MI stuff for DS2404 RTC

1 files changed, 125 insertions, 0 deletions

diff --git a/sys/dev/ic/ds.h b/sys/dev/ic/ds.h
new file mode 100644
index 00000000000..39837fc2469
--- /dev/null
+++ b/sys/dev/ic/ds.h
@@ -0,0 +1,125 @@
+/*	$OpenBSD: ds.h,v 1.1 1997/09/13 14:16:19 niklas Exp $	*/
+/*	$NetBSD: ds.h,v 1.1 1997/07/06 22:22:01 is Exp $	*/
+
+/*-
+ * Copyright (c) 1997 Ignatios Souvatzis. 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, 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.
+ * 3. Neither the name of the author nor the names of contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
+ */
+
+/*
+ * Definitions for access to Dallas Semiconductor chips which attach to 
+ * the same 1-wire bus as the DS2404 RTC.
+ */
+
+#ifndef DALLAS_SEMI_CHIPS_H
+#define DALLAS_SEMI_CHIPS_H
+
+/* Family codes (low byte of the ROM) */
+
+#define DS_FAMILY_2404	0x04	/* DS2404 Econoram Time Chip */
+
+/*
+ * ROM access codes. These are only available from the 1-wire bus, and one
+ * of them MUST be used before a memory access code is called. If you want
+ * to detect which devices are on the bus, you have to issue the ROM search
+ * function (see data sheet).
+ * If only one device is on the BUS, and you don't want any ROM function,
+ * issue the SKIP function.
+ * READ ROM works only if only one device is on the bus.
+ */
+
+#define DS_ROM_MATCH		0x55	/* 55 8-bytes-of-ROM-to-select */
+#define DS_ROM_SEARCH		0xf0	/* see data sheet */
+#define DS_ROM_SKIP		0xCC	/* don't do ROM function */
+#define DS_ROM_READ		0x33	/* 33 -> 8 bytes of ROM */
+
+/*
+ * Memory access codes. These are available from the 1- or 3-wire bus, and
+ * but you must use one of the ROM access codes first, if using the 1-wire 
+ * bus.
+ *
+ * You can read from any starting address up to the end of the chip, or
+ * abort the read with a reset pulse.
+ * You first write 2-32 bytes beginning some address to the scratchpad.
+ * Starting address and final byte stream length are remembered by the 
+ * chip. After reading data and address/length back from the scratchpad,
+ * and verifying the information, you can issue the copy scratchpad command
+ * to copy the written parts of the scratchpad to the corresponding parts
+ * of the implied (in the address) memory page.
+ */
+
+#define DS_MEM_WRITE_SCRATCH	0x0f	/* 0F low-ads high-ads data ... */
+#define DS_MEM_READ_SCRATCH	0xaa	/* AA -> low-ads high-ads end-ofs 
+					 * data ... */
+#define DS_MEM_COPY_SCRATCH	0x55	/* 55 low-ads high-ads end-ofs */
+#define DS_MEM_READ_MEMORY	0xf0	/* F0 low-ads high-ads -> data ...*/
+
+/*
+ * Hardware handle for access functions
+ */
+
+struct ds_handle {
+	int (*ds_read_bit) __P((void *));
+	void (*ds_write_bit) __P((void *, int));
+	void (*ds_reset) __P((void *));
+	void *ds_hw_handle;
+};
+
+/*
+ * Functions for access to Dallas Semiconductor chips which attach to 
+ * the same 1-wire bus as the DS2404 RTC.
+ */
+
+static __inline u_int8_t ds_read_byte __P((struct ds_handle *));
+static __inline void ds_write_byte __P((struct ds_handle *, unsigned int));
+
+static __inline u_int8_t
+ds_read_byte(dsh)
+	struct ds_handle *dsh;
+{
+	u_int8_t buf;
+	int i;
+
+	for (i = buf = 0; i < 8; ++i)
+		buf |= (dsh->ds_read_bit)(dsh->ds_hw_handle) << i;
+
+	return buf;
+}
+
+static __inline void
+ds_write_byte(dsh, b)
+	struct ds_handle *dsh;
+	unsigned int b;
+{
+	int i;
+
+	for (i = 0; i < 8; ++i) {
+		(dsh->ds_write_bit)(dsh->ds_hw_handle, b & 1);
+		b >>= 1;
+	}
+}
+
+#endif /* DALLAS_SEMI_CHIPS_H */