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linux/drivers/w1/w1.h
David Fries 8a0427d192 w1: optional bundling of netlink kernel replies 
Applications can submit a set of commands in one packet to the kernel,
and in some cases it is required such as reading the temperature
sensor results.  This adds an option W1_CN_BUNDLE to the flags of
cn_msg to request the kernel to reply in one packet for efficiency.

The cn_msg flags now check for unknown flag values and return an error
if one is seen.  See "Proper handling of unknown flags in system
calls" http://lwn.net/Articles/588444/

This corrects the ack values returned as per the protocol standard,
namely the original ack for status messages and seq + 1 for all others
such as the data returned from a read.

Some of the common variable names have been standardized as follows.
struct cn_msg *cn
struct w1_netlink_msg *msg
struct w1_netlink_cmd *cmd
struct w1_master *dev

When an argument and a function scope variable would collide, add req_
to the argument.

Signed-off-by: David Fries <David@Fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27 13:56:21 -07:00

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