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>
In order to send and receive ISO7816 APDUs to and from NFC embedded
secure elements, we define a specific netlink command.
On a typical SE use case, host applications will send very few APDUs
(Less than 10) per transaction. This is why we decided to go for a
simple netlink API. Defining another NFC socket protocol for such low
traffic would have been overengineered.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
SENS_RES has no specific endiannes attached to it, the kernel ABI is the
following one: Byte 2 (As described by the NFC Forum Digital spec) is
the u16 most significant byte.
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>
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>
struct nfc_phy_ops is not an HCI structure only, it can also be used by
NCI or direct NFC Core 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>
Use a more standard kernel style macro logging name.
Standardize the spacing of the "NFC: " prefix.
Add \n to uses, remove from macro.
Fix the defective uses that already had a \n.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Use the generic kernel function instead of a home-grown
one that does the same thing.
Add \n to uses not at the macro. Don't add \n where
the nfc_dev_dbg macro mistakenly had them already.
Signed-off-by: Joe Perches <joe@perches.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>
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>
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>
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>
When using NFC-F we should copy the NFCID2 buffer that we got from
SENSF_RES through the ATR_REQ NFCID3 buffer. Not doing so violates
NFC Forum digital requirement #189.
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>
This is a simple forward to the HCI driver. When driver is done with the
operation, it shall directly notify NFC Core by calling
nfc_fw_upload_done().
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
As several NFC chipsets can have their firmwares upgraded and
reflashed, this patchset adds a new netlink command to trigger
that the driver loads or flashes a new firmware. This will allows
userspace triggered firmware upgrade through netlink.
The firmware name or hint is passed as a parameter, and the driver
will eventually fetch the firmware binary through the request_firmware
API.
The cmd can only be executed when the nfc dev is not in use. Actual
firmware loading/flashing is an asynchronous operation. Result of the
operation shall send a new event up to user space through the nfc dev
multicast socket. During operation, the nfc dev is not openable and
thus not usable.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
skb->dev is used for carrying a net_device pointer and not
an nci_dev pointer.
Remove usage of skb-dev to carry nci_dev and replace it by parameter
in nci_recv_frame(), nci_send_frame() and driver send() functions.
NfcWilink driver is also updated to use those functions.
Signed-off-by: Frederic Danis <frederic.danis@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
All NFC devices will now get proper RFKILL support as long as they provide
some dev_up and dev_down hooks. Rfkilling an NFC device will bring it down
while it is left to userspace to bring it back up when being rfkill unblocked.
This is very similar to what Bluetooth does.
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Each NFC adapter can have several links to different secure elements and
that property needs to be exported by the drivers.
A secure element link can be enabled and disabled, and card emulation will
be handled by the currently active one. Otherwise card emulation will be
host implemented.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Some chips diverge from the HCI spec in their implementation of standard
features. This adds a new quirks parameter to
nfc_hci_allocate_device() to let the driver indicate its divergence.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
When an adapter is removed, it will unregister itself from hci and/or
nfc core. In order to do that safely, work tasks must first be canceled
and prevented to be scheduled again, before the hci or nfc device can be
destroyed.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
As a consequence the NFC device IDs won't be increasing all the time,
as IDR provides the first available ID.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
The driver now has all HCI stuff isolated in one file, and all the
hardware link specifics in another. Writing a pn544 driver on top of
another hardware link is now just a matter of adding a new file for that
new hardware specifics.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Set the local general bytes and default value for NFCIP1
Target/Initiator registries if the protocol is NFC-DEP
Signed-off-by: Arron Wang <arron.wang@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
xmit callback provided by a driver encapsulates upper layers
data and sends it to the hardware. So, HCI does not know the
exact amount of data being sent and thus can't handle partially
sent frames properly.
Therefore, the driver must return 0 for completely sent frame or
negative for failure.
Signed-off-by: Waldemar Rymarkiewicz <waldemar.rymarkiewicz@tieto.com>
Acked-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
The previous shdlc HCI driver and its header are removed from the tree.
PN544 now registers directly with HCI and passes the name of the llc it
requires (shdlc).
HCI instantiation now allocates the required llc instance. The llc is
started when the HCI device is brought up.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This is used by HCI drivers such as the one for the pn544 which require
communications between HCI and the chip to use shdlc.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This is a passthrough llc. It can be used by HCI drivers that don't
need link layer control. HCI will then write directly to the driver, and
driver will deliver incoming frames directly to HCI without any
processing.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
The LLC layer manages modules that control the link layer protocol (such
as shdlc) between HCI and an HCI driver. The driver must simply specify
the required llc when it registers with HCI.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This enables the completion callback to be called from a different
context, preventing a possible deadlock if the callback resulted in the
invocation of a nested call to the currently locked nfc_dev.
This is also more in line with the im_transceive nfc_ops for NFC Core or
NCI drivers which already behave asynchronously.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This method initiates execution of an HCI cmd. Result will be delivered
through an asynchronous callback.
Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
NFC is using a number of custom ordered workqueues w/ WQ_MEM_RECLAIM.
WQ_MEM_RECLAIM is unnecessary unless NFC is gonna be used as transport
for storage device, and all use cases match one work item to one
ordered workqueue - IOW, there's no actual ordering going on at all
and using system_nrt_wq gives the same behavior.
There's nothing to be gained by using custom workqueues. Use
system_nrt_wq instead and drop all the custom ones.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
During NFC-DEP target activation, store the remote
general bytes to be used later in dep_link_up.
When dep_link_up is called, activate the NFC-DEP target,
and forward the remote general bytes.
When dep_link_down is called, deactivate the target.
Signed-off-by: Ilan Elias <ilane@ti.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
