Fix racy hotplug handling by serialising all processing of hot-plug and
unplug requests using a single-threaded dedicated workqueue.

This fixes a reported crash during enumeration when processing multiple
events.

The current svc implementation does not handle concurrency at all (e.g.
no interface list lock or refcounting) so we need to use the big hammer
for now.

Note that we will eventually want to process events for different
interfaces in parallel, but that we'd still need a workqueue in order
not to starve other svc requests (e.g. for timesync).
Reported-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Defer processing also of hot-unplug events.

This is a step towards serialising hot-plug and unplug event processing.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Clean up and generalise deferred request handling by simply storing a
reference-counted pointer to the operation itself in the work context.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Pass the svc rather than its connection to the interface remove helper.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Rename the hotplug request message, and clarify that the message size
has already been verified by the primary handler.

Also add a debug message that includes the interface id.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Clean up hotplug/unplug request handlers somewhat.

Also add a debug message to both handlers that includes the interface id.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

The es2 chip doesn't have VID/PID programmed into the hardware and we
need to hack that up to distinguish different modules and their firmware
packages.

This fetches VID/PID (over firmware protocol) for es2 chip only, when
VID/PID already sent during hotplug are 0.

Since only the bootrom contains a firmware protocol cport, this only
affects bootrom's working and not nuttx.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Update the example sysfs-tree layout under Documentation due renamed
interface and bundle attributes.

The interface and bundle "id" attributes have been renamed
"interface_id" and "bundle_id" respectively to make them self
describing. For consistency reasons the bundle class attribute is
renamed as "bundle_class".

.
├── greybus1
│   ├── 1-2
│   │   ├── 1-2.1
│   │   │   ├── bundle_class
│   │   │   ├── bundle_id
│   │   │   └── state
│   │   ├── 1-2.2
│   │   │   ├── bundle_class
│   │   │   ├── bundle_id
│   │   │   └── state
│   │   ├── interface_id
│   │   ├── product_id
│   │   ├── unique_id
│   │   └── vendor_id
│   ├── 1-4
│   │   ├── 1-4.2
│   │   │   ├── bundle_class
│   │   │   ├── bundle_id
│   │   │   ├── gpbridge0
│   │   │   │   ├── gpio
│   │   │   │   │   └── gpiochip490
│   │   │   │   └── i2c-4
│   │   │   └── state
│   │   ├── interface_id
│   │   ├── product_id
│   │   ├── unique_id
│   │   └── vendor_id
│   └── 1-svc
│       ├── ap_intf_id
│       ├── eject
│       ├── endo_id
│       └── unique_id
└── greybus2
    ├── 2-3
    │   ├── 2-3.1
    │   │   ├── bundle_class
    │   │   ├── bundle_id
    │   │   └── state
    │   ├── interface_id
    │   ├── product_id
    │   ├── unique_id
    │   └── vendor_id
    └── 2-svc
        ├── ap_intf_id
        ├── eject
        ├── endo_id
        └── unique_id
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Drop the control bundle and ignore control descriptors when parsing
manifests.

Every interface has a control connection with a well defined remote
CPort 0 and there's no longer any need to create a bundle for it.

As the control connection is setup and enabled before parsing the
manifest, ignore any legacy descriptors for control cports and bundles
in a manifest.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Add helper function to release cport-descriptors with a given bundle id.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Remove conditional enabling of connections when binding protocols that
served no purpose as a connection either has no bundle or it has an
interface with a valid device id.

Also remove the now unused GB_PROTOCOL_NO_BUNDLE protocol flag.

This is an intermediate step in moving the protocol binding to
connection_init, but is also needed as the control bundle is going away.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

The control bundle is going away so update the code.

Also remove defensive WARN_ON which would not just warn if our
implementation is broken, but also leak further memory unnecessarily.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

The svc connection helper functions should not assume that all dynamic
connections will have a bundle.

This is needed as the control bundle is going away.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Remove the now unused endo and module code.

Note that the never-implemented serial and version attributes of the
endo can be implemented as svc attributes if needed.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Replace reference to "endo0" and generate the raw-latency filename based
on the host-device bus id instead.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Use dev_err and friends with the svc device for messages.
Clean up error messages.
Demote a few warnings to warning level.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Create the svc connection when registering the host-device and
remove the current svc connection hacks that "upgraded" the svc
connection once the endo id and ap interface id was known.

Note that the old implementation was partly based on a misunderstanding
as it was the remote interface id, rather than the local AP interface id,
that used to define a connection (but we also needed the endo_id).

The remote interface is no longer needed as static connections, such as
the svc connection, are now simply defined by the host-device and host
cport id.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Use host-device device and connection name for log messages, as not all
connections have a bundle.

Note that the "initial" svc connection has never had a bundle.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Use the host-device device and connection name for error messages, as
the operation code can not assume that a connection has a bundle.

Note that the "initial" svc connection has never had a bundle.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Use host-device device and connection name for log messages rather than
assume that all connections have a bundle (e.g. not true for static
connections).

Note that the "initial" svc connection has never had a bundle.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Add a name field to connections that can be used in log messages.

A connection always belongs to a host-device (bus) and can be uniquely
identified by its host-device cport id, but include remote interface and
cport id nonetheless on the following format:

	<hd_cport_id>/<intf_id>:<cport_id>

The remote interface and cport id will be zero for static connections.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Add helper to determine whether a connection is static, and remove the
protocol flag GB_PROTOCOL_SKIP_SVC_CONNECTION.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Make sure that the interface lookup helper can handle static,
bundle-less connections without oopsing when creating further
connections.

Note that the initial svc-connection has always been bundle-less, but
did not trigger an oops as a bundle was created for it before further
connections were created.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Clean up the connection-creation interface by clearly separating our two
types of connections: static and dynamic.

Add two convenience functions for creating static and dynamic connections.

A static connection is a pre-setup connection that is defined by a host
device and a host-device cport id. Specifically, the remote interface or
cport id need not be known. The SVC connection is a static connection.

A dynamic connection is defined by a host device and a remote interface
and cport id. This is our normal connections where the host-device cport
is (generally) allocated dynamically.

Note that the new generic interface is marked static, but can be
exported later to allow dynamic connections to be created also from
fixed host-device cports (e.g. for CSI).

Also note that a connection of either type is uniquely identified by its
host-device and host-device cport id once created.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Kill gb_create_bundle_connection, which was only used to create the
control bundle and connection, and replace it with a specialised static
helper.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Move endo_id and AP interface id to the svc device.

The endo abstraction is about to be removed, and these attributes are
arguable attributes of the svc anyway.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Register the svc device upon reception of the HELLO request.

The SVC HELLO request contains the endo id and AP interface id, which
will be exposed from the svc device rather than the endo.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Make sure to initialise the svc device fully before adding it to the
host device.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Make the svc object a child device of the host-device device and use
driver core to manage its lifetime.

The svc device name is "<bus_id>-svc", where bus_id is the dynamically
assigned id of the host device.

Note that there is exactly one svc-device per host device (bus).
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Rename bundle devices so that the new device names become
"<bus_id>-<intf_id>.<bundle_id>", where bus_id is the dynamically
allocated host-device bus id and intf_id the svc-allocated interface
id.

Using a period (.) rather than a colon (:) makes dev-messages easier to
read as as those already add a colon after the device name, for example:

	greybus 1-4.15: failed to connect cport: -22
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Make interfaces child devices of host devices.

The new interface device name is "<bus_id>-<intf_id>", where bus_id is
the dynamically allocated bus id for the host device and intf_id is the
svc-allocated interface id.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

The parent parameter was only used for debug messages and to name the
connection workqueue. Use the host-device device for this instead.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Make the host device a proper device in the kernel device model.

Host devices will be our new greybus-bus root devices.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Add a bundle_id attribute for the interface-unique id of a bundle that
user space can use for matching.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Use hexadecimal notation for class-attribute value.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Rename the bundle class-attribute "bundle_class" for consistency reasons
and to make it self documenting.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Add interface_id attribute that user space needs to identify an
interface.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

The interface device_id attribute is an implementation detail that does
not need to be exported to user space.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Rename vendor and product attributes vendor_id and product_id.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Update the ABI documentation to match the new device model.

Note that the SVC unique_id and version attributes are not yet
implemented.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>