HBM version 2.0 and above allows ME clients in the system to
register/unregister after the system is fully initialized.
Clients may be added or removed after enum_resp message was
received

1. To preserve backward compatibility the driver can opt-in to receive
client add messages by setting allow_add field in enum_req

2. A new client is added upon reception of MEI_HBM_ADD_CLIENT_REQ_CMD

3. A client is removed in a lazy manner when connection request
respond with MEI_HBMS_CLIENT_NOT_FOUND status
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

MEI bus was designed around nfc and was hard to extend.
Instead of the hard coded way of adding the devices on the mei bus
we scan the whole me client list and create a device for each
eligible me client (mei_cl_bus_rescan); currently we support
only clients with single connection and fixed address clients.
NFC radio name detection is run as a fixup routine

The patch replaces handling the device list based on struct me_cl
to device list based on me_cl_devices. The creating a connection
is pushed from the device creation time to device enablement.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove the dependency on struct ndev from the nfc device
name creation function so it is possible to use it
in a fixup routine
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Currently we support only clients with single connection
and fixed address clients so all other clients are blacklisted
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Blacklist nfc info client which is only used for retrieval
of the NFC radio version
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Split the device registration into allocation and device struct
initialization, device setup, and the final device registration.
This why it is possible to run fixups and quirks during the setup stage
on an initialized device. Each fixup routine effects do_match flag.
If the flag is set to false at the end the device won't be
registered on the bus.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Instead of holding the list of host clients (me_cl)
we want to keep the list me client devices (mei_cl_device)
This way we can create host to me client connection only when needed.
Add list head to mei_cl_device and cl_bus_lock
Add bus_added flag to the me client (mei_me_client) to track if
the appropriate mei_cl_device was already created and is_added
flag to mei_cl_device to track if it was already added to the device
list across the bus rescans
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add reference to the bus device (mei_device) for easier access.
To ensures that referencing cldev->bus is valid during cldev life time
we increase the bus ref counter on a client device creation and drop it
on the device release.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Instead of generating device id on the fly during probing we
find the matching id entry on the device id table.
Get bus the module reference counter so it cannot
be unloaded after the driver has bounded to the client
device
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

mei_cl_device_match now calls mei_cl_device_find that returns
the matching device id in the device id table.
We will utilize the mei_cl_device_find during probing
to locate the matching entry.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If event registeration has failed, the caller should know
about it.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Do not enable events implicitly in mei_cl_enable_device, it should be
done explicitly using mei_cl_register_event_cb so the events
are enabled only when needed.
The NFC drivers has been already using it that way so no need for
further changes just remove the code from mei_cl_enable_device.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Rename mei_cl_uevent to mei_cl_device_uevent to match
the naming convention of mei_cl_bus_type functions
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

To make the file more organize move mei client driver api
to the start of the file and add Kdoc.

There are no functional changes in this patch.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The bus-fixup.c will be a place for fixups and quirks
for all types of me client devices.
As for now it contians only the fixup for setting
the nfc device name on the me client bus.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In the mei bus layer there is use of different variables
of driver and device types with no clear naming convention.
There are generic struct device and struct driver,
then mei_cl_{device, driver}, and finally mei_device which
in this context serves as a bus device.

The patch sets following naming convention:

the variables of type struct device remains dev
the variables of type struct driver remains drv
the variables of type struct mei_cl_device are now cldev
the variables of type struct mei_cl_driver are now cldrv
the variables of type struct mei_device are now bus, in bus
layer context
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The mei_cl_write function is giving up on a write cb ownership after it
was sent or queued. The write cb is then freed in the completion
handler. Especially during blocking write mei_cl_write function waits
for the completion handler and then access the freed memory to fetch the
written size.  The quick fix is to store the buffer size prior to
sending, the size is not altered during the flow.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

chrdev_open() increases reference counter on cdev->owner. Instead of
assigning the owner to mei subsystem, the owner has to be set to the
underlaying HW module (mei_me or mei_txe), so once the device is opened
the HW module cannot be unloaded.

Cc: <stable@vger.kernel.org> #3.17+
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In function mei_nfc_host_exit mei_cl_remove_device cannot be called
under the device mutex as device removing flow invokes the device driver
remove handler that calls in turn to mei_cl_disable_device which
naturally acquires the device mutex.

Also remove mei_cl_bus_remove_devices which has the same issue, but is
never executed as currently the only device on the mei client bus is NFC
and a new device cannot be easily added till the bus revamp is
completed.

This fixes regression caused by commit be9b720a ("mei_phy: move all
nfc logic from mei driver to nfc")

Prior to this change the nfc driver remove handler called to no-op
disable function while actual nfc device was disabled directly from the
mei driver.
Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix the hbm power gating state machine so it will wait till it receives
confirmation interrupt for the PG_ISOLATION_EXIT message.

In process of the suspend flow the devices first have to exit from the
power gating state (runtime pm resume).
If we do not handle the confirmation interrupt after sending
PG_ISOLATION_EXIT message, we may receive it already after the suspend
flow has changed the device state and interrupt will be interpreted as a
spurious event, consequently link reset will be invoked which will
prevent the device from completing the suspend flow

kernel: [6603] mei_reset:136: mei_me 0000:00:16.0: powering down: end of reset
kernel: [476] mei_me_irq_thread_handler:643: mei_me 0000:00:16.0: function called after ISR to handle the interrupt processing.
kernel: mei_me 0000:00:16.0: FW not ready: resetting

Cc: <stable@vger.kernel.org> #3.18+
Cc: Gabriele Mazzotta <gabriele.mzt@gmail.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=86241
Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=770397Tested-by: NGabriele Mazzotta <gabriele.mzt@gmail.com>
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The FW resets the flow control for single buffer clients when the last
host client disconnects, also the driver has to follow this policy and
zero the flow control counter in such case.

Cc: <stable@vger.kernel.org> #4.1
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

A previous commit, c93b76b3 ("mei: bus: report also uuid in module
alias") caused a build error as I missed applying a needed patch to add
some macros to uapi/linux/uuid.h.  Instead of those additional macros,
change the mei code to use the existing uuid structure directly.

Fixes: c93b76b3
Cc: Tomas Winkler <tomas.winkler@intel.com>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Cc: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

since we move all nfc hanling to the mei_phy module
we can kill mei_cl_ops

Cc: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

move nfc logic to mei_phy module, we prefer as much as
possible not to deal with a particualr client protocol
in the mei generic infrasutcutre

Cc: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Export name and uuid via sysfs and uevent

Cc: linux-api@vger.kernel.org
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In order to automate modules matching add device uuid
which is reported in client enumeration, keep also
the name that is needed in for nfc distinguishing radio vendor

Report mei:name:uuid

Cc: linux-api@vger.kernel.org
Cc: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The io callback is clear from write_waitling_list after
we receive interrupt from the hw to ack the write completion.
We need to wait for this interrupt deliver before we try
to enter low power state
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

On longer non-blocking write might not complete at the end of
autosuspend expiration, therefore we request autosuspend
again on the write completion.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Consume the write flow control on the first chunk of the write instead
of on the buffer completion.
We can safely assume that the consequent chunks have the flow control
granted.

This addresses two issues:

1. Blocks other callbacks from the same client riding on the client's
flow control and prevents interleaving of messages as FW cannot distinguish
between two messages from the same client.

2. Fixes single buffer flow control arbitration in a clean way, without
connection/disconnection book keeping
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add client info to debug prints in the read function to
ease on debugging efforts.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove spurious blank
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We can receive mtu with one call now, no need to store it.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This should be used for debug only.
The feaure is gated by "allow_fixed_address" control exposed in debugfs.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixed address is simplified FW client that doesn't require
connection and doesn't support flow control.
So it can be only one host client per fixed FW client.
Fixed client access is available only for drivers on mei bus,
connection from user-space is blocked.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For ME clients that use single receiving buffer
the driver tracks credentials on mei_me_clients structure
for all connections. The driver needs to book keep the shared
resource correctly and track the connections, particularly
the credit has to be cleaned when there is no active connection
to a particular me client. This solves issue when subsequent
connection will not get an ill impression that it can write.

We add active connection counter the particular ME client and
when the counter reach zero, we clear the credits.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Keep a pointer to associated me client in the host client object to
eliminate me client searches. Check if the me client is active in the
firmware by checking if its is linked on the me clients list
Add accessors for the me client properties from host client.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Simplify connect state machine by changing the logic around
Connection request in progress - only check if we have a callback in
relevant queue.
Extract common code into mei_cl_send_connect() function
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Split disconnected state into two parts first reception disconnect
response from the firmware and second actually setting of disconnected
state.  Book keeping data are needed for processing and after firmware
disconnected the client and are cleaned when setting the disconnected
state in mei_cl_set_disconneted() function.
Add mei_cl_send_disconnect to reduce code duplication.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>