1 /* $NetBSD: ds.h,v 1.4 2002/03/24 15:51:45 bjh21 Exp $ */ 2 3 /*- 4 * Copyright (c) 1997 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Ignatios Souvatzis. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 /* 40 * Definitions for access to Dallas Semiconductor chips which attach to 41 * the same 1-wire bus as the DS2404 RTC. 42 */ 43 44 #ifndef DALLAS_SEMI_CHIPS_H 45 #define DALLAS_SEMI_CHIPS_H 46 47 /* Family codes (low byte of the ROM) */ 48 49 #define DS_FAMILY_2401 0x01 /* DS2401 Silicon Serial Number */ 50 #define DS_FAMILY_2404 0x04 /* DS2404 Econoram Time Chip */ 51 52 /* 53 * ROM access codes. These are only available from the 1-wire bus, and one 54 * of them MUST be used before a memory access code is called. If you want 55 * to detect which devices are on the bus, you have to issue the ROM search 56 * function (see data sheet). 57 * If only one device is on the BUS, and you don't want any ROM function, 58 * issue the SKIP function. 59 * READ ROM works only if only one device is on the bus. 60 */ 61 62 #define DS_ROM_MATCH 0x55 /* 55 8-bytes-of-ROM-to-select */ 63 #define DS_ROM_SEARCH 0xf0 /* see data sheet */ 64 #define DS_ROM_SKIP 0xCC /* don't do ROM function */ 65 #define DS_ROM_READ 0x33 /* 33 -> 8 bytes of ROM */ 66 67 /* 68 * Memory access codes. These are available from the 1- or 3-wire bus, and 69 * but you must use one of the ROM access codes first, if using the 1-wire 70 * bus. 71 * 72 * You can read from any starting address up to the end of the chip, or 73 * abort the read with a reset pulse. 74 * You first write 2-32 bytes beginning some address to the scratchpad. 75 * Starting address and final byte stream length are remembered by the 76 * chip. After reading data and address/length back from the scratchpad, 77 * and verifying the information, you can issue the copy scratchpad command 78 * to copy the written parts of the scratchpad to the corresponding parts 79 * of the implied (in the address) memory page. 80 */ 81 82 #define DS_MEM_WRITE_SCRATCH 0x0f /* 0F low-ads high-ads data ... */ 83 #define DS_MEM_READ_SCRATCH 0xaa /* AA -> low-ads high-ads end-ofs 84 * data ... */ 85 #define DS_MEM_COPY_SCRATCH 0x55 /* 55 low-ads high-ads end-ofs */ 86 #define DS_MEM_READ_MEMORY 0xf0 /* F0 low-ads high-ads -> data ...*/ 87 88 /* 89 * Hardware handle for access functions 90 */ 91 92 struct ds_handle { 93 int (*ds_read_bit) __P((void *)); 94 void (*ds_write_bit) __P((void *, int)); 95 void (*ds_reset) __P((void *)); 96 void *ds_hw_handle; 97 }; 98 99 /* 100 * Functions for access to Dallas Semiconductor chips which attach to 101 * the same 1-wire bus as the DS2404 RTC. 102 */ 103 104 static u_int8_t ds_read_byte __P((struct ds_handle *)); 105 static void ds_write_byte __P((struct ds_handle *, unsigned int)); 106 107 static inline u_int8_t 108 ds_read_byte(dsh) 109 struct ds_handle *dsh; 110 { 111 u_int8_t buf; 112 int i; 113 114 for (i=buf=0; i<8; ++i) 115 buf |= (dsh->ds_read_bit)(dsh->ds_hw_handle) << i; 116 117 return buf; 118 } 119 120 static inline void 121 ds_write_byte(dsh, b) 122 struct ds_handle *dsh; 123 unsigned int b; 124 { 125 int i; 126 127 for (i=0; i<8; ++i) { 128 (dsh->ds_write_bit)(dsh->ds_hw_handle, b & 1); 129 b >>= 1; 130 } 131 } 132 133 #endif /* DALLAS_SEMI_CHIPS_H */ 134