FreeBSD/Linux Kernel Cross Reference
sys/dev/ic/ds.h

     /*      $NetBSD: ds.h,v 1.4 2002/03/24 15:51:45 bjh21 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) __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 u_int8_t ds_read_byte __P((struct ds_handle *));
   static 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 */

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