f522d23961
Special file in each w1 slave device's directory called "rw" is created each time new slave and no appropriate w1 family is registered. "rw" file supports read and write operations, which allows to perform almost any kind of operations. Each logical operation is a transaction in nature, which can contain several (two or one) low-level operations. Let's see how one can read EEPROM context: 1. one must write control buffer, i.e. buffer containing command byte and two byte address. At this step bus is reset and appropriate device is selected using either W1_SKIP_ROM or W1_MATCH_ROM command. Then provided control buffer is being written to the wire. 2. reading. This will issue reading eeprom response. It is possible that between 1. and 2. w1 master thread will reset bus for searching and slave device will be even removed, but in this case 0xff will be read, since no device was selected. Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
218 lines
4.9 KiB
C
218 lines
4.9 KiB
C
/*
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* w1.h
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*
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* Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
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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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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 <net/sock.h>
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#include <asm/semaphore.h>
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#include "w1_family.h"
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#define W1_MAXNAMELEN 32
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#define W1_SLAVE_DATA_SIZE 128
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#define W1_SEARCH 0xF0
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#define W1_CONDITIONAL_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_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_SLAVE_ACTIVE 0
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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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u8 rom[9];
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u32 flags;
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int ttl;
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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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struct completion released;
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};
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typedef void (* w1_slave_found_callback)(void *, u64);
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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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struct w1_bus_master
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{
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/** the first parameter in all the functions below */
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void *data;
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/**
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* Sample the line level
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* @return the level read (0 or 1)
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*/
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u8 (*read_bit)(void *);
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/** Sets the line level */
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void (*write_bit)(void *, u8);
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/**
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* touch_bit is the lowest-level function for devices that really
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* support the 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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u8 (*touch_bit)(void *, u8);
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/**
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* 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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u8 (*read_byte)(void *);
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/**
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* Writes a byte. Same as 8 touch_bit(x) calls.
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*/
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void (*write_byte)(void *, u8);
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/**
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* 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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u8 (*read_block)(void *, u8 *, int);
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/** Same as a series of write_byte() calls */
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void (*write_block)(void *, const u8 *, int);
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/**
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* 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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u8 (*triplet)(void *, u8);
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/**
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* 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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u8 (*reset_bus)(void *);
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/** Really nice hardware can handles the ROM searches */
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void (*search)(void *, w1_slave_found_callback);
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};
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#define W1_MASTER_NEED_EXIT 0
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#define W1_MASTER_NEED_RECONNECT 1
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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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struct list_head slist;
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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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atomic_t refcnt;
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void *priv;
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int priv_size;
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long flags;
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struct task_struct *thread;
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struct semaphore 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, groups;
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struct sock *nls;
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};
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int w1_create_master_attributes(struct w1_master *);
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void w1_search(struct w1_master *dev, w1_slave_found_callback cb);
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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 int w1_max_slave_count;
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extern int w1_max_slave_ttl;
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extern spinlock_t w1_mlock;
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extern struct list_head w1_masters;
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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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int w1_process(void *data);
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void w1_reconnect_slaves(struct w1_family *f);
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#endif /* __KERNEL__ */
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#endif /* __W1_H */
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