Clean up coding style issues according to scripts/Lindent.
Some scripts/Lindent changes were reverted when it appeared
to make the code less readable or when it made the line run
over 80 characters.
Signed-off-by: NMark Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

The trf7970a driver uses the deprecated integer-based GPIO consumer
interface so convert it to use the new descriptor-based GPIO
consumer interface.
Signed-off-by: NMark Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

The 'vin-voltage-override' DT property is used by the trf7970a
driver to override the voltage presented to the driver by the
regulator subsystem.  This is unnecessary as properly specifying
the regulator chain via DT properties will accomplish the same
thing.  Therefore, remove support for 'vin-voltage-override'.
Signed-off-by: NMark Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

The last entry in the trf7970a_of_match[] table must be an empty
entry to demarcate the end of the table.  Currently, there is a
comment indicating this but it is obvious so remove the comment.
Signed-off-by: NMark Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

The quirk indicated by the 'en2-rf-quirk' device tree property
is only relevant when there is a GPIO connected to the EN2 pin
of the trf7970a. This means we should only check for 'en2-rf-quirk'
when EN2 is specified in the 'ti,enable-gpios' property of the
device tree.
Signed-off-by: NMark Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

As of commit ce69b95c ("NFC: Make EN2 pin optional in the
TRF7970A driver"), only the GPIO for the 'EN' enable pin needs
to be specified in the device tree so update the comments that
says both 'EN' and 'EN2' must be specified.
Signed-off-by: NMark Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

When the trf7970a part has the bug related to 'en2-rf-quirk',
the GPIO connected to the EN2 pin will not be asserted by the
driver when powering up so it shouldn't be de-asserted when
powering down.
Signed-off-by: NMark Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

The TRF7970A has configuration options for supporting hardware designs
with 1.8 Volt or 3.3 Volt IO.   This commit adds a device tree option,
using a fixed regulator binding, for setting the io voltage to match
the hardware configuration. If no option is supplied it defaults to
3.3 volt configuration.
Acked-by: NRob Herring <robh@kernel.org>
Acked-by: NMark Greer <mgreer@animalcreek.com>
Signed-off-by: NGeoff Lansberry <geoff@kuvee.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

The TRF7970A has configuration options to support hardware designs
which use a 27.12MHz clock. This commit adds a device tree option
'clock-frequency' to support configuring the this chip for default
13.56MHz clock or the optional 27.12MHz clock.
Acked-by: NRob Herring <robh@kernel.org>
Acked-by: NMark Greer <mgreer@animalcreek.com>
Signed-off-by: NGeoff Lansberry <geoff@kuvee.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Make the EN2 pin optional. This is useful for boards,
which have this pin fix wired, for example to ground.
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGuan Ben <ben.guan@cn.bosch.com>
Signed-off-by: NMark Jonas <mark.jonas@de.bosch.com>
Signed-off-by: NHeiko Schocher <hs@denx.de>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Signed-off-by: NGeoff Lansberry <geoff@kuvee.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Use to_spi_device() instead of open-coding it.
Signed-off-by: NGeliang Tang <geliangtang@163.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

An spi_driver does not need to set an owner, it will be populated by the
driver core.
Signed-off-by: NAndrew F. Davis <afd@ti.com>
Acked-by: NJonathan Cameron <jic23@kernel.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

The Documentation/devicetree/bindings/net/nfc/trf7970a.txt DT binding doc
lists "ti,trf7970a" as a compatible string but the corresponding driver
does not have an OF match table. Add the table to the driver so the SPI
core can do an OF style match.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Although it should be unnecessary, add a NULL pointer check
to trf7970a_send_upstream() to eliminate a smatch warning.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NMark Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

The SDD_EN bit in the NFC Target Detection Level Register
is bit 5 not bit 3 so change the TRF7970A_NFC_TARGET_LEVEL_SDD_EN
macro accordingly.
Reported-by: NRaymond Lei <Raymond.Lei@ecolab.com>
Signed-off-by: NMark Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

The current versions of the trf7970a has an erratum where it returns
an extra byte in the response to 'Read Multiple Block' (RMB) commands.
This command is issued to Type 5 tags (i.e., ISO/IEC 15693 tags) by
the neard daemon.

To handle this, define a new Device Tree property,
't5t-rmb-extra-byte-quirk', which indicates that the associated
trf7970a device has this erratum.  The trf7970a device driver
will then ensure that the response length to RMB commands is
reduced by one byte (for devices with the erratum).
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

After commit b2b49ccb (PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is
selected) PM_RUNTIME is always set if PM is set, so #ifdef blocks
depending on CONFIG_PM_RUNTIME may now be changed to depend on
CONFIG_PM.

Replace CONFIG_PM_RUNTIME with CONFIG_PM in drivers/nfc/trf7970a.c.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The recently added _trf7970a_tg_listen() routine
has some return paths that don't unlock the mutex
that is locked when the routine is entered.  Fix
this by always unlocking the mutex before returning.
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Recent changes to trf7970a_irq() added a couple return
paths that don't unlock the mutex that is locked when
the routine is entered.  Fix this by ensuring the mutex
is always unlocked before returning.
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

There is no need to initialize the 'ret' variable
in trf7970a_resume().
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

The trf7970a_suspend() routine always returns
zero so don't use a local return variable to
hold the return value.  This fixes up a smatch
warning.
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Add the ability to detect the mode (i.e., RF technology)
used by the initiator.  The RF technology that was
detected can be retrieved by calling the 'tg_get_rf_tech'
driver hook.
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Add target mode support to the trf7970a
NFC driver.  This effectively enables full
Peer-to-Peer support.

To handle changing framing between sending
a response frame and receiving the subsequent
request frame, most of the framing changes
take effect in the interrupt handler and not
in trf7970a_tg_config_framing().
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

The digital layer can try to send a command with a
timeout value of zero (e.g., digital_tg_send_psl_res().
The zero value is used as a flag to indicate that
the driver should not expect a response.  To handle
this, the driver sets an internal timer because it
should still get an interrupt with the TX bit set
in the IRQ Status Register.  When it gets that
interrupt, it returns a return value of '0'.
If it doesn't get the interrupt before timing out,
it returns ETIMEDOUT as usual.
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Some paths leave a timer still running when
trf7970a_send_err_upstream() is called.  This
can cause a timeout to occur in a subsequent
transaction making it fail.  Fix this by ensuring
there is no timer running before sending an error
upstream.
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Currently, the trf7970a driver blindly turns on its
RF field when configuring its framing.  This isn't
a good idea if there is already a device generating
an RF field.  Instead, check if there is already an
RF field present before turning on this device's RF
field and, if there is, return EBUSY.
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

When trf7970a_init() initializes the trf7970a it
implicitly turns off the RF transmitter.  Track
this by clearing the TRF7970A_CHIP_STATUS_RF_ON
bit in the cached trf->chip_status_ctrl.
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Don't try to turn off of RF transmitter is its
already off.
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Rename trf7970a_config_rf_tech() and trf7970a_config_framing()
to trf7970a_in_config_rf_tech() and trf7970a_in_config_framing(),
respectively to avoid confusion when target support is added.
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

The trf7970a should be given at least 1 ms to
completely initialize after the 'Software Init'
and 'Idle' commands have been issued.
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Add system suspend/resume support by gracefully
shutting things down when suspending and bringing
the device back to full power when resuming.
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Encapsulate the code to start up and gracefully
shutdown the driver and trf7970a device.  Doing
this makes adding system suspend/resume support
easier and the resulting code cleaner.
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

The current code assumes that CONFIG_PM_RUNTIME
is always defined so it won't power up the trf7970a
when it isn't enabled.  Fix this by moving the power
up/down code from the pm_runtime_resume/suspend
routines into their own routines and calling the
power up function from the probe routine.  This
ensures the device is powered up even when
CONFIG_PM_RUNTIME is not defined.

In order to not power on/off a device that is
already powered on/off, create a new state to
indicate that the power is off (TRF7970A_ST_PWR_OFF).
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Rename the 'TRF7970A_ST_OFF' state to 'TRF7970A_ST_RF_OFF'
to make it clear that this state means that the RF is
off and not the entire device.
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

trf7970a_switch_rf_on() is currently a void function
but turning on the RF could fail so it should return
a return code.  That return code should also be
propagated back to the entity that initiated the
action.
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Depending on the interrupt status value given by the
trf7970a, the driver may not know when a receive operation
is complete.  To handle this, the driver waits for a period
of time in case the trf7970a interrupts it again indicating
there are more RX data in the FIFO.  It is possible that the
timeout will occur when there are RX data in the FIFO but
before the trf7970a has generated an interrupt to tell the
driver about it.  Handle this by calling trf7970a_drain_fifo()
(instead of trf7970a_send_upstream() which just passes up the
data gathered to far) to check if there are more data in the
FIFO.  If so, gather that data into the receive buffer.  If
not, pass the data collected so far upstream as before.
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Receiving an interrupt whose Interrupt Status Register
value has only the SRX bit set is supposed to mean that
all of the data from the tag has been received.  That
turns out to not be true so we need to reread the FIFO
Status Register to tell if there are any new bytes in
the FIFO.  If there are, continue receiving them; if
there aren't, assume that the receive is complete and
pass the data up.
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Commit 4dd836e4 ("NFC: trf7970a: Reset FIFO when
'End of TX' Interrupt Occurs") fixes the issue that
it was meant to fix but adds the unfortunate side
effect of causing the driver to report an error
when the TX low-watermark level is passed during
transmits.  This can be fixed by checking whether
the IRQ status indicates that the low-watermark
has been passed when transmitting.  If it has been
passed and the FIFO is empty, then its safe to reset
the FIFO.  Otherwise, silently continue since another
TX interrupt will be generated and the FIFO will be
reset then.
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Handle the case where trf7970a_fill_fifo() is
called but there is no room in the FIFO for
more TX data.  When this happens, wait for
another interrupt indicating that there is
now space (and set a timer in case that
interrupt never occurs).
Signed-off-by: NMark A. Greer <mgreer@animalcreek.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>