134 lines
4.7 KiB
C
134 lines
4.7 KiB
C
/* $NetBSD: ds.h,v 1.8 2006/02/16 20:17:16 perry Exp $ */
|
|
|
|
/*-
|
|
* Copyright (c) 1997 The NetBSD Foundation, Inc.
|
|
* All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to The NetBSD Foundation
|
|
* by Ignatios Souvatzis.
|
|
*
|
|
* 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. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by the NetBSD
|
|
* Foundation, Inc. and its contributors.
|
|
* 4. Neither the name of The NetBSD Foundation nor the names of its
|
|
* contributors may be used to endorse or promote products derived
|
|
* from this software without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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_2401 0x01 /* DS2401 Silicon Serial Number */
|
|
#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)(void *);
|
|
void (*ds_write_bit)(void *, int);
|
|
void (*ds_reset)(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 u_int8_t ds_read_byte(struct ds_handle *);
|
|
static void ds_write_byte(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 */
|