This patch fix a previous patch introduce by commit	0a91e8ac

It is actually fixing a double free mistake in all st21nfca_tm_* function.
We decide to return directly in case of successful execution because skb
got already freed. In st21nfca_tm_recv_dep_req it got freed by nfc_tm_data_received.
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

scripts/checkpatch.pl -f drivers/nfc/st21nfca.c is throwing the following:
WARNING: else is not generally useful after a break or return
#866: FILE: drivers/nfc/st21nfca/st21nfca.c:866:
+			return 0;
+		} else {
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Align every macros on the same column.
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Clean up st21nfca.h macros and move the one only used in st21nfca.c.
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

If dev_num >= ST21NFCA_NUM_DEVICES, the driver was returning an incorrect
success return code.

Once dev_num is set, it was not stated as busy.
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Fixing scripts/checkpatch.pl warning "Missing a blank line after declarations" in:
- st21nfca.c:
	- check_presence after fwi variable declaration.
	- get_frame_size after len variable declaration.
	- st21nfca_hci_i2c_repack after "i, j, r, size" variable declaration.

- st21nfca_dep.c st21nfca_tx_work after skb pointer declaration.
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Fixing "sparse: cast to restricted __be32" message when building with
make C=1 CF=-D__CHECK_ENDIAN__
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: NSamuel 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: NChristophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Send DM_DISCONNECT command to disconnect Terminal Host from the HCI network.

- The persistent states of the terminal host pipes, including registry values,
are not modifies. Therefore, there is no NVRAM update to disconnect the
terminal host.
- The terminal host RF card gates are disabled which means that there will be no event
related to card RF gates until communication has been restored.
- The terminal host RF reader request is reset so the RF reader polling for terminal
host is disabled.

To restore the communication, the terminal host can send any HCI command or event.
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Add support for ISO/IEC 15693 RF technology and Type 5 tags.
ISO15963 is using proprietary gate 12.
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

In case anybody uses previous patchset with the CLF, add a check to make sure
missing pipe are created.
st21nfca returns its pipe list in the creation order (most recent latest).
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Remove unneeded includes from i2c.c
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Fix "warning: array subscript is above array bounds" in load_session
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Fixing "sparse: cast to restricted __be16" message when building with
make C=1 CF=-D__CHECK_ENDIAN__
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

This implementation rely on the ST21NFCA_DEVICE_MGNT_GATE and
ST21NFCA_DM_GETINFO proprietary gates commands.

First we are retrieving a pipe list available on the CLF with the
ST21NFCA_DM_GETINFO_PIPE_LIST parameter. A gate<->pipe table match
is done with ST21NFCA_DM_GETINFO_PIPE_INFO for each pipe.
If the pipe is created and open, we fill st21nfca_gates table.
If the pipe is create but closed or is not created we keep the gate
with NFC_HCI_INVALID_PIPE.
Signed-off-by: NChristophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: NSamuel 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: NChristophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>