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0a19f129d7
Since many temperature sensors come "preconfigured" with a lower precision, people are stuck at that precision when running on a kernel based device (unlike the Dallas 1Wire library for e.g. Arduino, which supports writing the configuration/scratchpad). This patch adds write support for the scratchpad/precision registers via w1_slave sysfs. Signed-off-by: Ben Sen <0.x29a.0@gmail.com> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
344 lines
10 KiB
C
344 lines
10 KiB
C
/*
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* w1.h
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*
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* Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
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*
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#ifndef __W1_H
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#define __W1_H
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/**
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* struct w1_reg_num - broken out slave device id
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*
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* @family: identifies the type of device
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* @id: along with family is the unique device id
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* @crc: checksum of the other bytes
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*/
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struct w1_reg_num
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{
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#if defined(__LITTLE_ENDIAN_BITFIELD)
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__u64 family:8,
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id:48,
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crc:8;
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#elif defined(__BIG_ENDIAN_BITFIELD)
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__u64 crc:8,
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id:48,
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family:8;
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#else
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#error "Please fix <asm/byteorder.h>"
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#endif
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};
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#ifdef __KERNEL__
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#include <linux/completion.h>
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#include <linux/device.h>
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#include <linux/mutex.h>
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#include "w1_family.h"
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#define W1_MAXNAMELEN 32
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#define W1_SEARCH 0xF0
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#define W1_ALARM_SEARCH 0xEC
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#define W1_CONVERT_TEMP 0x44
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#define W1_SKIP_ROM 0xCC
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#define W1_COPY_SCRATCHPAD 0x48
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#define W1_WRITE_SCRATCHPAD 0x4E
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#define W1_READ_SCRATCHPAD 0xBE
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#define W1_READ_ROM 0x33
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#define W1_READ_PSUPPLY 0xB4
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#define W1_MATCH_ROM 0x55
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#define W1_RESUME_CMD 0xA5
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#define W1_SLAVE_ACTIVE 0
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#define W1_SLAVE_DETACH 1
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/**
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* struct w1_slave - holds a single slave device on the bus
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*
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* @owner: Points to the one wire "wire" kernel module.
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* @name: Device id is ascii.
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* @w1_slave_entry: data for the linked list
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* @reg_num: the slave id in binary
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* @refcnt: reference count, delete when 0
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* @flags: bit flags for W1_SLAVE_ACTIVE W1_SLAVE_DETACH
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* @ttl: decrement per search this slave isn't found, deatch at 0
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* @master: bus which this slave is on
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* @family: module for device family type
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* @family_data: pointer for use by the family module
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* @dev: kernel device identifier
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*
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*/
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struct w1_slave
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{
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struct module *owner;
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unsigned char name[W1_MAXNAMELEN];
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struct list_head w1_slave_entry;
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struct w1_reg_num reg_num;
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atomic_t refcnt;
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int ttl;
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unsigned long flags;
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struct w1_master *master;
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struct w1_family *family;
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void *family_data;
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struct device dev;
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};
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typedef void (*w1_slave_found_callback)(struct w1_master *, u64);
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/**
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* struct w1_bus_master - operations available on a bus master
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*
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* @data: the first parameter in all the functions below
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*
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* @read_bit: Sample the line level @return the level read (0 or 1)
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*
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* @write_bit: Sets the line level
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*
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* @touch_bit: the lowest-level function for devices that really support the
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* 1-wire protocol.
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* touch_bit(0) = write-0 cycle
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* touch_bit(1) = write-1 / read cycle
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* @return the bit read (0 or 1)
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*
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* @read_byte: Reads a bytes. Same as 8 touch_bit(1) calls.
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* @return the byte read
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*
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* @write_byte: Writes a byte. Same as 8 touch_bit(x) calls.
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*
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* @read_block: Same as a series of read_byte() calls
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* @return the number of bytes read
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*
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* @write_block: Same as a series of write_byte() calls
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*
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* @triplet: Combines two reads and a smart write for ROM searches
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* @return bit0=Id bit1=comp_id bit2=dir_taken
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*
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* @reset_bus: long write-0 with a read for the presence pulse detection
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* @return -1=Error, 0=Device present, 1=No device present
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*
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* @set_pullup: Put out a strong pull-up pulse of the specified duration.
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* @return -1=Error, 0=completed
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*
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* @search: Really nice hardware can handles the different types of ROM search
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* w1_master* is passed to the slave found callback.
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* u8 is search_type, W1_SEARCH or W1_ALARM_SEARCH
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*
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* Note: read_bit and write_bit are very low level functions and should only
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* be used with hardware that doesn't really support 1-wire operations,
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* like a parallel/serial port.
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* Either define read_bit and write_bit OR define, at minimum, touch_bit and
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* reset_bus.
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*
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*/
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struct w1_bus_master
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{
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void *data;
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u8 (*read_bit)(void *);
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void (*write_bit)(void *, u8);
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u8 (*touch_bit)(void *, u8);
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u8 (*read_byte)(void *);
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void (*write_byte)(void *, u8);
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u8 (*read_block)(void *, u8 *, int);
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void (*write_block)(void *, const u8 *, int);
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u8 (*triplet)(void *, u8);
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u8 (*reset_bus)(void *);
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u8 (*set_pullup)(void *, int);
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void (*search)(void *, struct w1_master *,
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u8, w1_slave_found_callback);
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};
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/**
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* enum w1_master_flags - bitfields used in w1_master.flags
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* @W1_ABORT_SEARCH: abort searching early on shutdown
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* @W1_WARN_MAX_COUNT: limit warning when the maximum count is reached
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*/
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enum w1_master_flags {
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W1_ABORT_SEARCH = 0,
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W1_WARN_MAX_COUNT = 1,
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};
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/**
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* struct w1_master - one per bus master
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* @w1_master_entry: master linked list
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* @owner: module owner
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* @name: dynamically allocate bus name
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* @list_mutex: protect slist and async_list
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* @slist: linked list of slaves
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* @async_list: linked list of netlink commands to execute
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* @max_slave_count: maximum number of slaves to search for at a time
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* @slave_count: current number of slaves known
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* @attempts: number of searches ran
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* @slave_ttl: number of searches before a slave is timed out
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* @initialized: prevent init/removal race conditions
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* @id: w1 bus number
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* @search_count: number of automatic searches to run, -1 unlimited
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* @search_id: allows continuing a search
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* @refcnt: reference count
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* @priv: private data storage
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* @enable_pullup: allows a strong pullup
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* @pullup_duration: time for the next strong pullup
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* @flags: one of w1_master_flags
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* @thread: thread for bus search and netlink commands
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* @mutex: protect most of w1_master
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* @bus_mutex: pretect concurrent bus access
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* @driver: sysfs driver
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* @dev: sysfs device
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* @bus_master: io operations available
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* @seq: sequence number used for netlink broadcasts
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*/
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struct w1_master
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{
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struct list_head w1_master_entry;
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struct module *owner;
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unsigned char name[W1_MAXNAMELEN];
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/* list_mutex protects just slist and async_list so slaves can be
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* searched for and async commands added while the master has
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* w1_master.mutex locked and is operating on the bus.
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* lock order w1_mlock, w1_master.mutex, w1_master.list_mutex
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*/
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struct mutex list_mutex;
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struct list_head slist;
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struct list_head async_list;
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int max_slave_count, slave_count;
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unsigned long attempts;
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int slave_ttl;
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int initialized;
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u32 id;
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int search_count;
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/* id to start searching on, to continue a search or 0 to restart */
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u64 search_id;
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atomic_t refcnt;
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void *priv;
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/** 5V strong pullup enabled flag, 1 enabled, zero disabled. */
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int enable_pullup;
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/** 5V strong pullup duration in milliseconds, zero disabled. */
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int pullup_duration;
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long flags;
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struct task_struct *thread;
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struct mutex mutex;
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struct mutex bus_mutex;
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struct device_driver *driver;
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struct device dev;
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struct w1_bus_master *bus_master;
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u32 seq;
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};
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/**
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* struct w1_async_cmd - execute callback from the w1_process kthread
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* @async_entry: link entry
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* @cb: callback function, must list_del and destroy this list before
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* returning
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*
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* When inserted into the w1_master async_list, w1_process will execute
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* the callback. Embed this into the structure with the command details.
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*/
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struct w1_async_cmd {
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struct list_head async_entry;
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void (*cb)(struct w1_master *dev, struct w1_async_cmd *async_cmd);
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};
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int w1_create_master_attributes(struct w1_master *);
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void w1_destroy_master_attributes(struct w1_master *master);
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void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb);
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void w1_search_devices(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb);
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/* call w1_unref_slave to release the reference counts w1_search_slave added */
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struct w1_slave *w1_search_slave(struct w1_reg_num *id);
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/* decrements the reference on sl->master and sl, and cleans up if zero
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* returns the reference count after it has been decremented */
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int w1_unref_slave(struct w1_slave *sl);
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void w1_slave_found(struct w1_master *dev, u64 rn);
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void w1_search_process_cb(struct w1_master *dev, u8 search_type,
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w1_slave_found_callback cb);
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struct w1_slave *w1_slave_search_device(struct w1_master *dev,
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struct w1_reg_num *rn);
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struct w1_master *w1_search_master_id(u32 id);
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/* Disconnect and reconnect devices in the given family. Used for finding
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* unclaimed devices after a family has been registered or releasing devices
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* after a family has been unregistered. Set attach to 1 when a new family
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* has just been registered, to 0 when it has been unregistered.
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*/
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void w1_reconnect_slaves(struct w1_family *f, int attach);
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int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn);
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/* 0 success, otherwise EBUSY */
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int w1_slave_detach(struct w1_slave *sl);
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u8 w1_triplet(struct w1_master *dev, int bdir);
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void w1_write_8(struct w1_master *, u8);
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u8 w1_read_8(struct w1_master *);
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int w1_reset_bus(struct w1_master *);
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u8 w1_calc_crc8(u8 *, int);
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void w1_write_block(struct w1_master *, const u8 *, int);
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void w1_touch_block(struct w1_master *, u8 *, int);
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u8 w1_read_block(struct w1_master *, u8 *, int);
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int w1_reset_select_slave(struct w1_slave *sl);
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int w1_reset_resume_command(struct w1_master *);
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void w1_next_pullup(struct w1_master *, int);
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static inline struct w1_slave* dev_to_w1_slave(struct device *dev)
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{
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return container_of(dev, struct w1_slave, dev);
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}
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static inline struct w1_slave* kobj_to_w1_slave(struct kobject *kobj)
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{
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return dev_to_w1_slave(container_of(kobj, struct device, kobj));
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}
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static inline struct w1_master* dev_to_w1_master(struct device *dev)
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{
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return container_of(dev, struct w1_master, dev);
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}
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extern struct device_driver w1_master_driver;
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extern struct device w1_master_device;
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extern int w1_max_slave_count;
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extern int w1_max_slave_ttl;
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extern struct list_head w1_masters;
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extern struct mutex w1_mlock;
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extern int w1_process_callbacks(struct w1_master *dev);
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extern int w1_process(void *);
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#endif /* __KERNEL__ */
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#endif /* __W1_H */
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