linux/net/nfc/Kconfig

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# SPDX-License-Identifier: GPL-2.0-only
#
# NFC subsystem configuration
#
menuconfig NFC
depends on RFKILL || !RFKILL
tristate "NFC subsystem support"
default n
help
Say Y here if you want to build support for NFC (Near field
communication) devices.
To compile this support as a module, choose M here: the module will
be called nfc.
NFC: Digital Protocol stack implementation 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>
2013-09-19 23:55:25 +08:00
config NFC_DIGITAL
depends on NFC
NFC Digital: Add NFC-A technology support 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>
2013-09-19 23:55:27 +08:00
select CRC_CCITT
select CRC_ITU_T
NFC: Digital Protocol stack implementation 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>
2013-09-19 23:55:25 +08:00
tristate "NFC Digital Protocol stack support"
default n
help
Say Y if you want to build NFC digital protocol stack support.
This is needed by NFC chipsets whose firmware only implement
the NFC analog layer.
To compile this support as a module, choose M here: the module will
be called nfc_digital.
source "net/nfc/nci/Kconfig"
source "net/nfc/hci/Kconfig"
source "drivers/nfc/Kconfig"