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    Subject[W1] Updated documentation.
    Date

    Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net>
    ---
    Documentation/w1/w1.netlink | 34 +++++++++++++++++++++++++---------
    1 files changed, 25 insertions(+), 9 deletions(-)

    diff --git a/Documentation/w1/w1.netlink b/Documentation/w1/w1.netlink
    index 3640c7c..eae5c8b 100644
    --- a/Documentation/w1/w1.netlink
    +++ b/Documentation/w1/w1.netlink
    @@ -17,25 +17,27 @@ Protocol.
    [struct cn_msg] - connector header. It's length field is equal to size of the attached data.
    [struct w1_netlink_msg] - w1 netlink header.
    __u8 type - message type.
    + W1_LIST_MASTERS - list current bus master list
    W1_SLAVE_ADD/W1_SLAVE_REMOVE - slave add/remove events.
    W1_MASTER_ADD/W1_MASTER_REMOVE - master add/remove events.
    W1_MASTER_CMD - userspace command for bus master device (search/alarm search).
    W1_SLAVE_CMD - userspace command for slave device (read/write/ search/alarm search
    for bus master device where given slave device found).
    __u8 res - reserved
    - __u16 len - size of attached to this header data.
    + __u16 len - size of data attached to this header data.
    union {
    - __u8 id; - slave unique device id
    + __u8 id[8]; - slave unique device id
    struct w1_mst {
    __u32 id; - master's id.
    __u32 res; - reserved
    } mst;
    } id;

    -[strucrt w1_netlink_cmd] - command for gived master or slave device.
    +[struct w1_netlink_cmd] - command for given master or slave device.
    __u8 cmd - command opcode.
    W1_CMD_READ - read command.
    W1_CMD_WRITE - write command.
    + W1_CMD_TOUCH - touch command (write and sample data back to userspace).
    W1_CMD_SEARCH - search command.
    W1_CMD_ALARM_SEARCH - alarm search command.
    __u8 res - reserved
    @@ -44,7 +46,7 @@ Protocol.
    __u8 data[0] - data for this command.


    -Each connector message can include one or more w1_netlink_msg with zero of more attached w1_netlink_cmd messages.
    +Each connector message can include one or more w1_netlink_msg with zero or more attached w1_netlink_cmd messages.

    For event messages there are no w1_netlink_cmd embedded structures, only connector header
    and w1_netlink_msg strucutre with "len" field being zero and filled type (one of event types)
    @@ -59,11 +61,25 @@ cn_msg.len = sizeof(struct w1_netlink_msg) + sizeof(struct w1_netlink_cmd) + cmd
    w1_netlink_msg.len = sizeof(struct w1_netlink_cmd) + cmd->len;
    w1_netlink_cmd.len = cmd->len;

    +Replies to W1_LIST_MASTERS should send a message back to the userspace
    +which will contain list of all registered master ids in the following
    +format:
    +
    + cn_msg (CN_W1_IDX.CN_W1_VAL as id, len is equal to sizeof(struct
    + w1_netlink_msg) plus number of masters multipled by 4)
    + w1_netlink_msg (type: W1_LIST_MASTERS, len is equal to number of masters
    + multiplied by 4 (u32 size))
    + id0 ... idN
    +
    + Each message is at most 4k in size, so if number of master devices
    + exceeds this, it will be split into several messages, cn.seq will be
    + increased for each one.
    +

    Operation steps in w1 core when new command is received.
    =======================================================

    -When new message (w1_netlink_msg) is received w1 core detects if it is master of slave request,
    +When new message (w1_netlink_msg) is received w1 core detects if it is master or slave request,
    according to w1_netlink_msg.type field.
    Then master or slave device is searched for.
    When found, master device (requested or those one on where slave device is found) is locked.
    @@ -82,10 +98,10 @@ Connector [1] specific documentation.
    Each connector message includes two u32 fields as "address".
    w1 uses CN_W1_IDX and CN_W1_VAL defined in include/linux/connector.h header.
    Each message also includes sequence and acknowledge numbers.
    -Sequence number for event messages is appropriate bus master sequence number increased with
    +Sequence number for event messages is appropriate bus master sequence number increased with
    each event message sent "through" this master.
    Sequence number for userspace requests is set by userspace application.
    -Sequence number for reply is the same as was in request, and
    +Sequence number for reply is the same as was in request, and
    acknowledge number is set to seq+1.


    @@ -93,6 +109,6 @@ Additional documantion, source code examples.
    ============================================

    1. Documentation/connector
    -2. http://tservice.net.ru/~s0mbre/archive/w1
    -This archive includes userspace application w1d.c which
    +2. http://www.ioremap.net/archive/w1
    +This archive includes userspace application w1d.c which
    uses read/write/search commands for all master/slave devices found on the bus.
    --
    1.5.2.5


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