Now that genl_ops are no longer modified in place when
registering, they can be made const. This patch was done
mostly with spatch:
@@
identifier ops;
@@
+const
struct genl_ops ops[] = {
...
};
(except the struct thing in net/openvswitch/datapath.c)
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
se_io_cb can be declared static. This fixes the following sparse
warning:
net/nfc/netlink.c:1287:6: warning: symbol 'se_io_cb' was not declared.
Should it be static?
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
The NFC Forum NCI specification defines both a hardware and software
protocol when using a SPI physical transport to connect an NFC NCI
Chipset. The hardware requirement is that, after having raised the chip
select line, the SPI driver must wait for an INT line from the NFC
chipset to raise before it sends the data. The chip select must be
raised first though, because this is the signal that the NFC chipset
will detect to wake up and then raise its INT line. If the INT line
doesn't raise in a timely fashion, the SPI driver should abort
operation.
When data is transferred from Device host (DH) to NFC Controller (NFCC),
the signaling sequence is the following:
Data Transfer from DH to NFCC
• 1-Master asserts SPI_CSN
• 2-Slave asserts SPI_INT
• 3-Master sends NCI-over-SPI protocol header and payload data
• 4-Slave deasserts SPI_INT
• 5-Master deasserts SPI_CSN
When data must be transferred from NFCC to DH, things are a little bit
different.
Data Transfer from NFCC to DH
• 1-Slave asserts SPI_INT -> NFC chipset irq handler called -> process
reading from SPI
• 2-Master asserts SPI_CSN
• 3-Master send 2-octet NCI-over-SPI protocol header
• 4-Slave sends 2-octet NCI-over-SPI protocol payload length
• 5-Slave sends NCI-over-SPI protocol payload
• 6-Master deasserts SPI_CSN
In this case, SPI driver should function normally as it does today. Note
that the INT line can and will be lowered anytime between beginning of
step 3 and end of step 5. A low INT is therefore valid after chip select
has been raised.
This would be easily implemented in a single driver. Unfortunately, we
don't write the SPI driver and I had to imagine some workaround trick to
get the SPI and NFC drivers to work in a synchronized fashion. The trick
is the following:
- send an empty spi message: this will raise the chip select line, and
send nothing. We expect the /CS line will stay arisen because we asked
for it in the spi_transfer cs_change field
- wait for a completion, that will be completed by the NFC driver IRQ
handler when it knows we are in the process of sending data (NFC spec
says that we use SPI in a half duplex mode, so we are either sending or
receiving).
- when completed, proceed with the normal data send.
This has been tested and verified to work very consistently on a Nexus
10 (spi-s3c64xx driver). It may not work the same with other spi
drivers.
The previously defined nci_spi_ops{} whose intended purpose were to
address this problem are not used anymore and therefore totally removed.
The nci_spi_send() takes a new optional write_handshake_completion
completion pointer. If non NULL, the nci spi layer will run the above
trick when sending data to the NFC Chip. If NULL, the data is sent
normally all at once and it is then the NFC driver responsibility to
know what it's doing.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Previously, nci_spi_recv_frame() would directly transmit incoming frames
to the NCI Core. However, it turns out that some NFC NCI Chips will add
additional proprietary headers that must be handled/removed before NCI
Core gets a chance to handle the frame. With this modification, the chip
phy or driver are now responsible to transmit incoming frames to NCI
Core after proper treatment, and NCI SPI becomes a driver helper instead
of sitting between the NFC driver and NCI Core.
As a general rule in NFC, *_recv_frame() APIs are used to deliver an
incoming frame to an upper layer. To better suit the actual purpose of
nci_spi_recv_frame(), and go along with its nci_spi_send()
counterpart, the function is renamed to nci_spi_read()
The skb is returned as the function result
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Using ARM compiler, and without zero-ing spi_transfer, spi-s3c64xx
driver would issue abnormal errors due to bpw field value being set to
unexpected value. This structure MUST be set to all zeros except for
those field specifically used.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Implementation of the NFC_CMD_SE_IO command for sending ISO7816 APDUs to
NFC embedded secure elements. The reply is forwarded to user space
through NFC_CMD_SE_IO as well.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This was triggered by the following sparse warning:
net/nfc/digital_technology.c:272:20: sparse: cast to restricted __be16
The SENS_RES response must be treated as __le16 with the first byte
received as LSB and the second one as MSB. This is the way neard
handles it in the sens_res field of the nfc_target structure which is
treated as u16 in cpu endianness. So le16_to_cpu() is used on the
received SENS_RES instead of memcpy'ing it.
SENS_RES test macros have also been fixed accordingly.
Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
In the rawsock data exchange callback, the sk_buff is not freed
on error.
Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Fixes sparse hint:
net/nfc/digital_technology.c:640:5: sparse: symbol 'digital_tg_send_sensf_res'
was not declared. Should it be static?
Cc: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
We do not add the newline to the pr_fmt macro, in order to give more
flexibility to the caller and to keep the logging style consistent with
the rest of the NFC and kernel code.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
They can be replaced by the standard pr_err and pr_debug one after
defining the right pr_fmt macro.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Storing the spi device was forgotten in the original implementation,
which would pretty obviously cause some kind of serious crash when
actually trying to send something through that device.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This adds support for NFC-DEP target mode for NFC-A and NFC-F
technologies.
If the driver provides it, the stack uses an automatic mode for
technology detection and automatic anti-collision. Otherwise the stack
tries to use non-automatic synchronization and listens for SENS_REQ and
SENSF_REQ commands.
The detection, activation, and data exchange procedures work exactly
the same way as in initiator mode, as described in the previous
commits, except that the digital stack waits for commands and sends
responses back to the peer device.
Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This adds support for NFC-DEP protocol in initiator mode for NFC-A and
NFC-F technologies.
When a target is detected, the process flow is as follow:
For NFC-A technology:
1 - The digital stack receives a SEL_RES as the reply of the SEL_REQ
command.
2 - If b7 of SEL_RES is set, the peer device is configure for NFC-DEP
protocol. NFC core is notified through nfc_targets_found().
Execution continues at step 4.
3 - Otherwise, it's a tag and the NFC core is notified. Detection
ends.
4 - The digital stacks sends an ATR_REQ command containing a randomly
generated NFCID3 and the general bytes obtained from the LLCP layer
of NFC core.
For NFC-F technology:
1 - The digital stack receives a SENSF_RES as the reply of the
SENSF_REQ command.
2 - If B1 and B2 of NFCID2 are 0x01 and 0xFE respectively, the peer
device is configured for NFC-DEP protocol. NFC core is notified
through nfc_targets_found(). Execution continues at step 4.
3 - Otherwise it's a type 3 tag. NFC core is notified. Detection
ends.
4 - The digital stacks sends an ATR_REQ command containing the NFC-F
NFCID2 as NFCID3 and the general bytes obtained from the LLCP layer
of NFC core.
For both technologies:
5 - The digital stacks receives the ATR_RES response containing the
NFCID3 and the general bytes of the peer device.
6 - The digital stack notifies NFC core that the DEP link is up through
nfc_dep_link_up().
7 - The NFC core performs data exchange through tm_transceive().
8 - The digital stack sends a DEP_REQ command containing an I PDU with
the data from NFC core.
9 - The digital stack receives a DEP_RES command
10 - If the DEP_RES response contains a supervisor PDU with timeout
extension request (RTOX) the digital stack sends a DEP_REQ
command containing a supervisor PDU acknowledging the RTOX
request. The execution continues at step 9.
11 - If the DEP_RES response contains an I PDU, the response data is
passed back to NFC core through the response callback. The
execution continues at step 8.
Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This adds polling support for NFC-F technology at 212 kbits/s and 424
kbits/s. A user space application like neard can send type 3 tag
commands through the NFC core.
Process flow for NFC-F detection is as follow:
1 - The digital stack sends the SENSF_REQ command to the NFC device.
2 - A peer device replies with a SENSF_RES response.
3 - The digital stack notifies the NFC core of the presence of a
target in the operation field and passes the target NFCID2.
This also adds support for CRC calculation of type CRC-F. The CRC
calculation is handled by the digital stack if the NFC device doesn't
support it.
Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This adds support for NFC-A technology at 106 kbits/s. The stack can
detect tags of type 1 and 2. There is no support for collision
detection. Tags can be read and written by using a user space
application or a daemon like neard.
The flow of polling operations for NFC-A detection is as follow:
1 - The digital stack sends the SENS_REQ command to the NFC device.
2 - The NFC device receives a SENS_RES response from a peer device and
passes it to the digital stack.
3 - If the SENS_RES response identifies a type 1 tag, detection ends.
NFC core is notified through nfc_targets_found().
4 - Otherwise, the digital stack sets the cascade level of NFCID1 to
CL1 and sends the SDD_REQ command.
5 - The digital stack selects SEL_CMD and SEL_PAR according to the
cascade level and sends the SDD_REQ command.
4 - The digital stack receives a SDD_RES response for the cascade level
passed in the SDD_REQ command.
5 - The digital stack analyses (part of) NFCID1 and verify BCC.
6 - The digital stack sends the SEL_REQ command with the NFCID1
received in the SDD_RES.
6 - The peer device replies with a SEL_RES response
7 - Detection ends if NFCID1 is complete. NFC core notified of new
target by nfc_targets_found().
8 - If NFCID1 is not complete, the cascade level is incremented (up
to and including CL3) and the execution continues at step 5 to
get the remaining bytes of NFCID1.
Once target detection is done, type 1 and 2 tag commands must be
handled by a user space application (i.e neard) through the NFC core.
Responses for type 1 tag are returned directly to user space via NFC
core.
Responses of type 2 commands are handled differently. The digital stack
doesn't analyse the type of commands sent through im_transceive() and
must differentiate valid responses from error ones.
The response process flow is as follow:
1 - If the response length is 16 bytes, it is a valid response of a
READ command. the packet is returned to the NFC core through the
callback passed to im_transceive(). Processing stops.
2 - If the response is 1 byte long and is a ACK byte (0x0A), it is a
valid response of a WRITE command for example. First packet byte
is set to 0 for no-error and passed back to the NFC core.
Processing stops.
3 - Any other response is treated as an error and -EIO error code is
returned to the NFC core through the response callback.
Moreover, since the driver can't differentiate success response from a
NACK response, the digital stack has to handle CRC calculation.
Thus, this patch also adds support for CRC calculation. If the driver
doesn't handle it, the digital stack will calculate CRC and will add it
to sent frames. CRC will also be checked and removed from received
frames. Pointers to the correct CRC calculation functions are stored in
the digital stack device structure when a target is detected. This
avoids the need to check the current target type for every call to
im_transceive() and for every response received from a peer device.
Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This implements the mechanism used to send commands to the driver in
initiator mode through in_send_cmd().
Commands are serialized and sent to the driver by using a work item
on the system workqueue. Responses are handled asynchronously by
another work item. Once the digital stack receives the response through
the command_complete callback, the next command is sent to the driver.
This also implements the polling mechanism. It's handled by a work item
cycling on all supported protocols. The start poll command for a given
protocol is sent to the driver using the mechanism described above.
The process continues until a peer is discovered or stop_poll is
called. This patch implements the poll function for NFC-A that sends a
SENS_REQ command and waits for the SENS_RES response.
Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This is the initial commit of the NFC Digital Protocol stack
implementation.
It offers an interface for devices that don't have an embedded NFC
Digital protocol stack. The driver instantiates the digital stack by
calling nfc_digital_allocate_device(). Within the nfc_digital_ops
structure, the driver specifies a set of function pointers for driver
operations. These functions must be implemented by the driver and are:
in_configure_hw:
Hardware configuration for RF technology and communication framing in
initiator mode. This is a synchronous function.
in_send_cmd:
Initiator mode data exchange using RF technology and framing previously
set with in_configure_hw. The peer response is returned through
callback cb. If an io error occurs or the peer didn't reply within the
specified timeout (ms), the error code is passed back through the resp
pointer. This is an asynchronous function.
tg_configure_hw:
Hardware configuration for RF technology and communication framing in
target mode. This is a synchronous function.
tg_send_cmd:
Target mode data exchange using RF technology and framing previously
set with tg_configure_hw. The peer next command is returned through
callback cb. If an io error occurs or the peer didn't reply within the
specified timeout (ms), the error code is passed back through the resp
pointer. This is an asynchronous function.
tg_listen:
Put the device in listen mode waiting for data from the peer device.
This is an asynchronous function.
tg_listen_mdaa:
If supported, put the device in automatic listen mode with mode
detection and automatic anti-collision. In this mode, the device
automatically detects the RF technology and executes the
anti-collision detection using the command responses specified in
mdaa_params. The mdaa_params structure contains SENS_RES, NFCID1, and
SEL_RES for 106A RF tech. NFCID2 and system code (sc) for 212F and
424F. The driver returns the NFC-DEP ATR_REQ command through cb. The
digital stack deducts the RF tech by analyzing the SoD of the frame
containing the ATR_REQ command. This is an asynchronous function.
switch_rf:
Turns device radio on or off. The stack does not call explicitly
switch_rf to turn the radio on. A call to in|tg_configure_hw must turn
the device radio on.
abort_cmd:
Discard the last sent command.
Then the driver registers itself against the digital stack by using
nfc_digital_register_device() which in turn registers the digital stack
against the NFC core layer. The digital stack implements common NFC
operations like dev_up(), dev_down(), start_poll(), stop_poll(), etc.
This patch is only a skeleton and NFC operations are just stubs.
Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
As we can potentially get DEP up events without having sent a netlink
command, we need to set the active target properly from dep_link_is_up.
Spontaneous DEP up events can come from devices that detected an active
p2p target. In that case there is no need to call the netlink DEP up
command as the link is already up and running.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
NCI SPI layer should not manage the nci dev, this is the job of the nci
chipset driver. This layer should be limited to frame/deframe nci
packets, and optionnaly check integrity (crc) and manage the ack/nak
protocol.
The NCI SPI must not be mixed up with an NCI dev. spi_[dev|device] are
therefore renamed to a simple spi for more clarity.
The header and crc sizes are moved to nci.h so that drivers can use
them to reserve space in outgoing skbs.
nci_spi_send() is exported to be accessible by drivers.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
An hci dev is an hdev. An nci dev is an ndev. Calling an nci spi dev an
ndev is misleading since it's not the same thing. The nci dev contained
in the nci spi dev is also named inconsistently.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This will be needed by all NFC driver implementing the SE ops.
Signed-off-by: Arron Wang <arron.wang@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
The secure element state was not updated from the enable/disable ops,
leaving the SE state to disabled for ever.
Signed-off-by: Arron Wang <arron.wang@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Another typo from the initial commit where we check for the secure
element type field instead of its state when enabling or disabling it.
Signed-off-by: Arron Wang <arron.wang@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
There is a cut and paste bug so we enable a second time instead of
disabling.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Result is added as an NFC_ATTR_FIRMWARE_DOWNLOAD_STATUS attribute
containing the standard errno positive value of the completion result.
This event will be sent when the firmare download operation is done and
will contain the operation result.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This API must be called by NFC drivers, and its prototype was
incorrectly placed.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
In order to fetch the discovered secure elements from an NFC controller,
we need to send a netlink command that will dump the list of available
SEs from NFC.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This is a typo coming from the initial implementation. se_discover fails
when it returns something different than zero and we should only display
a warning in that case.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Loading a firmware into a target is typically called firmware
download, not firmware upload. So we rename the netlink API to
NFC_CMD_FW_DOWNLOAD in order to avoid any terminology confusion from
userspace.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
kbuild test robot found following error:
net/built-in.o: In function `nci_spi_send':
>> spi.c:(.text+0x19a76f): undefined reference to `crc_ccitt'
Add CRC_CCITT module to Kconfig to fix it
Reported-by: kbuild test robot.
Signed-off-by: Frederic Danis <frederic.danis@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
The WKS (Well Known Services) bitmask should be transmitted in big endian
order. Picky implementations will refuse to establish an LLCP link when the
WKS bit 0 is not set to 1. The vast majority of implementations out there
are not that picky though...
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
In order to advertise our LLCP support properly and to follow the LLCP
specs requirements, we need to initialize the WKS (Well-Known Services)
bitfield to 1 as SAP 0 is the only mandatory supported service.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
When we receive a RNR, the remote is busy processing the last received
frame. We set a local flag for that, and we should send a SYMM when it
is set instead of sending any pending frame.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Without the new LLCP_CONNECTING state, non blocking sockets will be
woken up with a POLLHUP right after calling connect() because their
state is stuck at LLCP_CLOSED.
That prevents userspace from implementing any proper non blocking
socket based NFC p2p client.
Cc: stable@vger.kernel.org
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
In nfc_llcp_tx_work() the sk_buff is not freed when the llcp_sock
is null and the PDU is an I one.
Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This patch keeps the socket alive and therefore does not remove
it from the sockets list in the local until the DISC PDU has been
actually sent. Otherwise we would reply with DM PDUs before sending
the DISC one.
Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
nfc_llcp_send_disconnect() already exists but is not used.
nfc_llcp_disconnect() naming is not consistent with other PDU
sending functions.
This patch removes nfc_llcp_send_disconnect() and renames
nfc_llcp_disconnect()
Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Enabling or disabling an NFC accessible secure element through netlink
requires giving both an NFC controller and a secure element indexes.
Once enabled the secure element will handle card emulation once polling
starts.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Called via netlink, this API will enable or disable a specific secure
element. When a secure element is enabled, it will handle card emulation
and more generically ISO-DEP target mode, i.e. all target mode cases
except for p2p target mode.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
When an NFC driver or host controller stack discovers a secure element,
it will call nfc_add_se(). In order for userspace applications to use
these secure elements, a netlink event will then be sent with the SE
index and its type. With that information userspace applications can
decide wether or not to enable SEs, through their indexes.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This API will allow NFC drivers to add and remove the secure elements
they know about or detect. Typically this should be called (asynchronously
or not) from the driver or the host interface stack detect_se hook.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Secure elements need to be discovered after enabling the NFC controller.
This is typically done by the NCI core and the HCI drivers (HCI does not
specify how to discover SEs, it is left to the specific drivers).
Also, the SE enable/disable API explicitely takes a SE index as its
argument.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Supported secure elements are typically found during a discovery process
initiated when the NFC controller is up and running. For a given NFC
chipset there can be many configurations (embedded SE or not, with or
without a SIM card wired to the NFC controller SWP interface, etc...) and
thus driver code will never know before hand which SEs are available.
So we remove this field, it will be replaced by a real SE discovery
mechanism.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Before any operation, driver interruption is de-asserted to prevent
race condition between TX and RX.
Transaction starts by emitting "Direct read" and acknowledged mode
bytes. Then packet length is read allowing to allocate correct NCI
socket buffer. After that payload is retrieved.
A delay after the transaction can be added.
This delay is determined by the driver during nci_spi_allocate_device()
call and can be 0.
If acknowledged mode is set:
- CRC of header and payload is checked
- if frame reception fails (CRC error): NACK is sent
- if received frame has ACK or NACK flag: unblock nci_spi_send()
Payload is passed to NCI module.
At the end, driver interruption is re asserted.
Signed-off-by: Frederic Danis <frederic.danis@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Before any operation, driver interruption is de-asserted to prevent
race condition between TX and RX.
The NCI over SPI header is added in front of NCI packet.
If acknowledged mode is set, CRC-16-CCITT is added to the packet.
Then the packet is forwarded to SPI module to be sent.
A delay after the transaction is added.
This delay is determined by the driver during nci_spi_allocate_device()
call and can be 0.
After data has been sent, driver interruption is re-asserted.
If acknowledged mode is set, nci_spi_send will block until
acknowledgment is received.
Signed-off-by: Frederic Danis <frederic.danis@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
The NFC Forum defines a transport interface based on
Serial Peripheral Interface (SPI) for the NFC Controller
Interface (NCI).
This module implements the SPI transport of NCI, calling SPI module
directly to read/write data to NFC controller (NFCC).
NFCC driver should provide functions performing device open and close.
It should also provide functions asserting/de-asserting interruption
to prevent TX/RX race conditions.
NFCC driver can also fix a delay between transactions if needed by
the hardware.
Signed-off-by: Frederic Danis <frederic.danis@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>