Commit Graph

61 Commits

Author SHA1 Message Date
Mark A. Greer
ebcc5a0d08 NFC: trf7970a: Set correct Vin voltage in Chip Status Control register
Currently, the trf7970a driver assumes that the Vin voltage is 5V when
it writes to the 'Chip Status Control' register. That may not be correct
so use the regulator facility to get the Vin voltage and set the VRS5_3
bit correctly when writing to that register.

Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2014-04-22 00:37:27 +02:00
Mark A. Greer
12e9ade309 NFC: trf7970a: Allow different Modulator and SYS_CLK Control register values
Currently the driver writes the same value to the 'Modulator and SYS_CLK
Control' register no matter what RF technology is being used. That works
for now but new RF technologies (e.g., ISO/IEC 14443-B) will require
different values to be written to that register. To support this, add a
member to the trf7970a structure which is set by the RF technology handling
code and used by the framing code when it writes to that register.

Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2014-04-22 00:37:27 +02:00
Mark A. Greer
a0822a7e3b NFC: trf7970a: Set 'Modulator and SYS_CLK Control' after 'ISO Control'
Writing to the 'ISO Control' register may cause the contents of the
'Modulator and SYS_CLK Control' register to change so be sure to write
to 'Modulator and SYS_CLK Control' after writing to 'ISO Control'.

Note that writing to the 'Modulator and SYS_CLK Control' register
shouldn't be necessary at all according to the trf790a manual but testing
shows that it is necessary.

Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2014-04-22 00:37:27 +02:00
Mark A. Greer
49d19cc794 NFC: trf7970a: Only write 'ISO Control' when its changing
The current code always writes to the 'ISO Control' register when the
RF framing is set.  That's not necessary since the register's value
doesn't always change. Instead, only write to it when its value is
actually being changed.

Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2014-04-22 00:37:27 +02:00
Mark A. Greer
4dd836e46c NFC: trf7970a: Reset FIFO when 'End of TX' Interrupt Occurs
Sometimes after sending a frame there is tx data leftover in the FIFO
which the driver will think is part of the receive frame. That data can
be cleared when an 'End of TX' interrupt is received by issuing the
'FIFO Reset' command.

Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2014-04-22 00:37:27 +02:00
Mark A. Greer
b887eb09d3 NFC: trf7970a: Clear 'NFC Target Detection Level' register
Due to a trf7970a erratum, the 'NFC Target Detection Level' register
(0x18) must be cleared after power-up.

Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2014-04-22 00:37:27 +02:00
Mark A. Greer
5876bc75e2 NFC: trf7970a: Only abort a command if one is active
Only initiate the abort command process when there is an active command.
If the abort process were started and there wasn't an active command
then the next command issued by the digital layer would be incorrectly
aborted.

Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2014-04-22 00:37:26 +02:00
Mark A. Greer
5fa3af352b NFC: trf7970a: Increase TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT to 20 ms
After further testing periods of ~16 ms have been observed
between interrupts indicating that there is receive data in
the FIFO.  To accomodate that, increase the time the driver
waits before deciding there is no more data to receive to
20 ms.  The macro that represents that delay is
'TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT'.

Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2014-04-22 00:37:26 +02:00
Mark A. Greer
9d9304b321 NFC: trf7970a: Add ISO/IEC 15693 and Type 5 tag Support
Add support for ISO/IEC 15693 RF technology and Type 5 tags.
Note that Type 5 tags used to be referred to as Type V tags.

CC: Erick Macias <emacias@ti.com>
CC: Felipe Balbi <balbi@ti.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2014-03-11 00:47:09 +01:00
Mark A. Greer
8006289108 NFC: trf7970a: Add support for Type 4A Tags
Add support for Type 4A Tags which includes
supporting the underlying ISO/IEC 14443-A
protocol.

Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2014-03-11 00:47:08 +01:00
Mark A. Greer
165063f1da NFC: trf7970a: Add driver with ISO/IEC 14443 Type 2 Tag Support
Add a driver for the Texas Instruments TRF7970a RFID/NFC/15693
transceiver.  The driver currently supports ISO/IEC 14443 Type 2
tags only (MIFARE Ultralight and Ultralight C but not Classic).

CC: Erick Macias <emacias@ti.com>
CC: Felipe Balbi <balbi@ti.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2014-03-11 00:46:55 +01:00