linux/drivers/w1/w1.h

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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
w1: add 1-wire (w1) reset and resume command API support The first patch adds generic functionnality to w1_io for Resume Command [A5h] lots of slaves support. I found it useful for multi-commands/reset workflows with the same slave on a multi-slave bus. This DS2408 w1 slave driver is not complete for all the features of the chip, but its sufficient if you use it as a simple IO expander. Enjoy! The ds1wm had Kconfig dependencies towards ARM && HAVE_CLK. I took them out since I was using the ds1wm on an x86_64 platform (ds1wm in a FPGA through pcie) and found them irrelevant. The clock freq/divisors at the top of ds1wm.c did not have the MSB set to 1. This bit is CLK_EN which turns the whole prescaler and dividers on. The driver never mentionned this bit either, so I just included this bit right in the table entries. I also took the liberty to add a couple of entries to the table. The spec doesn't explicitely mentions these possibilities but the description and examination of the core shows the prescalers & dividers can be used for more than the table explicitely shows. The table I enlarged still doesn't cover all possibilities, but it's a good start. I also made a few tweaks to a couple of the read and write algorithms which made sense while I had my head very deep in the ds1wm documentation. We stressed it a lot with 10+ slaves on the bus, many ds2408, ds2431 and ds2433 at the same time doing extensive interaction. It proved quite stable in our production environment. This patch: Add generic functionnality to w1_io for Resume Command [A5h] lots of slaves support. Signed-off-by: Jean-François Dagenais <dagenaisj@sonatest.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Cc: Szabolcs Gyurko <szabolcs.gyurko@tlt.hu> Cc: Matt Reimer <mreimer@vpop.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-26 23:26:01 +00:00
#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 *);
W1: feature, enable hardware strong pullup Add a strong pullup option to the w1 system. This supplies extra power for parasite powered devices. There is a w1_master_pullup sysfs entry and enable_pullup module parameter to enable or disable the strong pullup. The one wire bus requires at a minimum one wire and ground. The common wire is used for sending and receiving data as well as supplying power to devices that are parasite powered of which temperature sensors can be one example. The bus must be idle and left high while a temperature conversion is in progress, in addition the normal pullup resister on larger networks or even higher temperatures might not supply enough power. The pullup resister can't provide too much pullup current, because devices need to pull the bus down to write a value. This enables the strong pullup for supported hardware, which can supply more current when requested. Unsupported hardware will just delay with the bus high. The hardware USB 2490 one wire bus master has a bit on some commands which will enable the strong pullup as soon as the command finishes executing. To use strong pullup, call the new w1_next_pullup function to register the duration. The next write command will call set_pullup before sending the data, and reset the duration to zero once it returns. Switched from simple_strtol to strict_strtol. Signed-off-by: David Fries <david@fries.net> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 05:04:42 +00:00
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;
W1: feature, enable hardware strong pullup Add a strong pullup option to the w1 system. This supplies extra power for parasite powered devices. There is a w1_master_pullup sysfs entry and enable_pullup module parameter to enable or disable the strong pullup. The one wire bus requires at a minimum one wire and ground. The common wire is used for sending and receiving data as well as supplying power to devices that are parasite powered of which temperature sensors can be one example. The bus must be idle and left high while a temperature conversion is in progress, in addition the normal pullup resister on larger networks or even higher temperatures might not supply enough power. The pullup resister can't provide too much pullup current, because devices need to pull the bus down to write a value. This enables the strong pullup for supported hardware, which can supply more current when requested. Unsupported hardware will just delay with the bus high. The hardware USB 2490 one wire bus master has a bit on some commands which will enable the strong pullup as soon as the command finishes executing. To use strong pullup, call the new w1_next_pullup function to register the duration. The next write command will call set_pullup before sending the data, and reset the duration to zero once it returns. Switched from simple_strtol to strict_strtol. Signed-off-by: David Fries <david@fries.net> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 05:04:42 +00:00
/** 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;
W1: split master mutex to avoid deadlocks. The 'mutex' in struct w1_master is use for two very different purposes. Firstly it protects various data structures such as the list of all slaves. Secondly it protects the w1 buss against concurrent accesses. This can lead to deadlocks when the ->probe code called while adding a slave needs to talk on the bus, as is the case for power_supply devices. ds2780 and ds2781 drivers contain a work around to track which process hold the lock simply to avoid this deadlock. bq27000 doesn't have that work around and so deadlocks. There are other possible deadlocks involving sysfs. When removing a device the sysfs s_active lock is held, so the lock that protects the slave list must take precedence over s_active. However when access power_supply attributes via sysfs, the s_active lock must take precedence over the lock that protects accesses to the bus. So to avoid deadlocks between w1 slaves and sysfs, these must be two separate locks. Making them separate means that the work around in ds2780 and ds2781 can be removed. So this patch: - adds a new mutex: "bus_mutex" which serialises access to the bus. - takes in mutex in w1_search and ds1wm_search while they access the bus for searching. The mutex is dropped before calling the callback which adds the slave. - changes all slaves to use bus_mutex instead of mutex to protect access to the bus - removes w1_ds2790_io_nolock and w1_ds2781_io_nolock, and the related code from drivers/power/ds278[01]_battery.c which calls them. Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-18 05:59:52 +00:00
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);
w1: add 1-wire (w1) reset and resume command API support The first patch adds generic functionnality to w1_io for Resume Command [A5h] lots of slaves support. I found it useful for multi-commands/reset workflows with the same slave on a multi-slave bus. This DS2408 w1 slave driver is not complete for all the features of the chip, but its sufficient if you use it as a simple IO expander. Enjoy! The ds1wm had Kconfig dependencies towards ARM && HAVE_CLK. I took them out since I was using the ds1wm on an x86_64 platform (ds1wm in a FPGA through pcie) and found them irrelevant. The clock freq/divisors at the top of ds1wm.c did not have the MSB set to 1. This bit is CLK_EN which turns the whole prescaler and dividers on. The driver never mentionned this bit either, so I just included this bit right in the table entries. I also took the liberty to add a couple of entries to the table. The spec doesn't explicitely mentions these possibilities but the description and examination of the core shows the prescalers & dividers can be used for more than the table explicitely shows. The table I enlarged still doesn't cover all possibilities, but it's a good start. I also made a few tweaks to a couple of the read and write algorithms which made sense while I had my head very deep in the ds1wm documentation. We stressed it a lot with 10+ slaves on the bus, many ds2408, ds2431 and ds2433 at the same time doing extensive interaction. It proved quite stable in our production environment. This patch: Add generic functionnality to w1_io for Resume Command [A5h] lots of slaves support. Signed-off-by: Jean-François Dagenais <dagenaisj@sonatest.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Cc: Szabolcs Gyurko <szabolcs.gyurko@tlt.hu> Cc: Matt Reimer <mreimer@vpop.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-26 23:26:01 +00:00
int w1_reset_resume_command(struct w1_master *);
W1: feature, enable hardware strong pullup Add a strong pullup option to the w1 system. This supplies extra power for parasite powered devices. There is a w1_master_pullup sysfs entry and enable_pullup module parameter to enable or disable the strong pullup. The one wire bus requires at a minimum one wire and ground. The common wire is used for sending and receiving data as well as supplying power to devices that are parasite powered of which temperature sensors can be one example. The bus must be idle and left high while a temperature conversion is in progress, in addition the normal pullup resister on larger networks or even higher temperatures might not supply enough power. The pullup resister can't provide too much pullup current, because devices need to pull the bus down to write a value. This enables the strong pullup for supported hardware, which can supply more current when requested. Unsupported hardware will just delay with the bus high. The hardware USB 2490 one wire bus master has a bit on some commands which will enable the strong pullup as soon as the command finishes executing. To use strong pullup, call the new w1_next_pullup function to register the duration. The next write command will call set_pullup before sending the data, and reset the duration to zero once it returns. Switched from simple_strtol to strict_strtol. Signed-off-by: David Fries <david@fries.net> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 05:04:42 +00:00
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 */