st21nfca has 1 physical SWP line and can support up to 2 secure elements
(UICC & eSE) thanks to an external switch managed with a gpio.

The platform integrator needs to specify thanks to 2 initialization
properties, uicc-present and ese-present, if it is suppose to have uicc
and/or ese. Of course if the platform does not have an external switch,
only one kind of secure element can be supported. Those parameters are
under platform integrator responsibilities.

During initialization, the white_list will be set according to those
parameters.

The discovery_se function will assume a secure element is physically
present according to uicc-present and ese-present values and will add it
to the secure element list. On ese activation, the atr is retrieved to
calculate a command exchange timeout based on the first atr(TB) value.

The se_io will allow to transfer data over SWP. 2 kind of events may appear
after a data is sent over:
- ST21NFCA_EVT_TRANSMIT_DATA when receiving an apdu answer
- ST21NFCA_EVT_WTX_REQUEST when the secure element needs more time than
expected to compute a command. If this timeout expired, a first recovery
tentative consist to send a simple software reset proprietary command.
If this tentative still fail, a second recovery tentative consist to send
a hardware reset proprietary command.
This function is only relevant for eSE like secure element.

This patch also change the way a pipe is referenced. There can be
different pipe connected to the same gate with different host destination
(ex: CONNECTIVITY). In order to keep host information every pipe are
reference with a tuple (gate, host). In order to reduce changes, we are
keeping unchanged the way a gate is addressed on the Terminal Host.
However, this is working because we consider the apdu reader gate is only
present on the eSE slot also the connectivity gate cannot give a reliable
value; it will give the latest stored pipe value.
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

In the previous makefile 2 modules were generated for CONFIG_NFC_ST21NFCA
(st21nfca.ko and st21nfca_dep.ko). Merge both of them into st21nfca_hci.ko
and fix a potential depmod dependency cycle, similar to the one we saw
on st21nfcb:

depmod: WARNING: found 6 modules in dependency cycles!
depmod: WARNING:
/lib/modules/3.17.0-rc3-00002-g7505ceaf/kernel/drivers/nfc/st21nfcb/st21nfcb.ko
in dependency cycle!
depmod: WARNING:
/lib/modules/3.17.0-rc3-00002-g7505ceaf/kernel/drivers/nfc/st21nfcb/ndlc.ko
in dependency cycle!
depmod: WARNING:
/lib/modules/3.17.0-rc3-00002-g7505ceaf/kernel/net/rfkill/rfkill.ko in
dependency cycle!
depmod: WARNING:
/lib/modules/3.17.0-rc3-00002-g7505ceaf/kernel/net/nfc/nfc.ko in
dependency cycle!
depmod: WARNING:
/lib/modules/3.17.0-rc3-00002-g7505ceaf/kernel/net/nfc/nci/nci.ko in
dependency cycle!
depmod: WARNING:
/lib/modules/3.17.0-rc3-00002-g7505ceaf/kernel/lib/crc-ccitt.ko in
dependency cycle!
./scripts/depmod.sh: line 57: 23387 Segmentation fault      (core
dumped) "$DEPMOD" "$@" "$KERNELRELEASE" $SYMBOL_PREFIX
make: *** [_modinst_post] Error 139
Reported-by: Daniel Wagner <wagi@monom.org>
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Support for Initiator and Target mode with ISO18092 commands support:
- ATR_REQ/ATR_RES
- PSL_REQ/PSL_RES
- DEP_REQ/DEP_RES

Work based on net/nfc/digital_dep.c.
st21nfca is using:
- Gate reader F for P2P in initiator mode.
- Gate card F for P2P in target mode.

Felica tag and p2p are differentiated with NFCID2.
When starting with 01FE it is acting in p2p mode.

On complete_target_discovered on ST21NFCA_RF_READER_F_GATE
supported_protocols is set to NFC_PROTO_NFC_DEP_MASK
for P2P.

Tested against: Nexus S, Galaxy S2, Galaxy S3, Galaxy S3 Mini,
Nexus 4 & Nexus 5.
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Add driver for STMicroelectronics ST21NFCA NFC controller.
ST21NFCA is using HCI protocol, shdlc as LLC layer & I2C as
communication protocol.

Adding support for Reader/Writer mode with Tag type 1/2/3/4 A & B.
It is using proprietary gate 15 for ISO14443-3 such as type 1 &
type 2 tags. It is using proprietary gate 14 for type F tags.
ST21NFCA_DEVICE_MGNT_GATE gives access to proprietary CLF configuration.
Standard gate for ISO14443-4 A (13) & B (11) are also used.

ST21NFCA specific mecanism:

One particular point to notice for the data handling is that frame
does not contain any length value. Therefore the i2c part of this driver
is managing the reception with a read length sequence until the end of
frame (0x7e) is reached.

In order to avoid conflict between sof & eof a mecanism
called byte stuffing concist of an escape byte (0x7d) insertion before
special byte (0x7e, 0x7d). The special byte is then xored with 0x20.

In this driver, When data are available in the CLF, the interrupt
gpio is driven to active state and triggered an interrupt.
Once the i2c_master_recv start, the interrupt gpio is driven to idle
state until its complete. If the frame is incomplete or data are still
available, interrupts will be triggered again.
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>