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path: root/drivers/nfc/trf7970a.c
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* NFC: trf7970a: Unlock mutex before exiting _trf7970a_tg_listen()Mark A. Greer2014-09-23
| | | | | | | | | | 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: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Unlock mutex before exiting trf7970a_irq()Mark A. Greer2014-09-23
| | | | | | | | | | 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: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Remove unnecessary local variable initializationMark A. Greer2014-09-23
| | | | | | | | There is no need to initialize the 'ret' variable in trf7970a_resume(). Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Remove useless local variableMark A. Greer2014-09-23
| | | | | | | | | | 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: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Add Target Mode Detection SupportMark A. Greer2014-09-07
| | | | | | | | | | 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: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Add Target Mode SupportMark A. Greer2014-09-07
| | | | | | | | | | | | | | | 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: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Handle timeout values of zeroMark A. Greer2014-09-07
| | | | | | | | | | | | | | | | 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: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Cancel timer when error encounteredMark A. Greer2014-09-07
| | | | | | | | | | | | 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: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Don't turn on RF if there is already an RF fieldMark A. Greer2014-09-07
| | | | | | | | | | | | 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: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: trf7970a_init() turns off the RF transmitterMark A. Greer2014-09-07
| | | | | | | | | | 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: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Don't turn off RF if its already offMark A. Greer2014-09-07
| | | | | | | | Don't try to turn off of RF transmitter is its already off. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Add '_in_' to initiator routinesMark A. Greer2014-09-07
| | | | | | | | | 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: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Delay after initializationMark A. Greer2014-09-07
| | | | | | | | | 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: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Add System Suspend/Resume supportMark A. Greer2014-09-07
| | | | | | | | | 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: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Create startup and shutdown routinesMark A. Greer2014-09-07
| | | | | | | | | | 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: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Don't assume CONFIG_PM_RUNTIME is enabledMark A. Greer2014-09-07
| | | | | | | | | | | | | | | | | | 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: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Rename TRF7970A_ST_OFF to TRF7970A_ST_RF_OFFMark A. Greer2014-09-07
| | | | | | | | | 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: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Return error code when turning on RF failsMark A. Greer2014-09-07
| | | | | | | | | | | 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: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Ensure no more RX data before completing receiveMark A. Greer2014-09-07
| | | | | | | | | | | | | | | | | | 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: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Reread FIFO Status Register when draining FIFOMark A. Greer2014-09-07
| | | | | | | | | | | | | | 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: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Handle low-watermark IRQ when transmittingMark A. Greer2014-09-07
| | | | | | | | | | | | | | | | | | Commit 4dd836e46c3d ("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: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Only fill FIFO if there is spaceMark A. Greer2014-09-07
| | | | | | | | | | | | 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: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Prefix TX data when refilling FIFOMark A. Greer2014-09-07
| | | | | | | | | | | | | | | | | | | | | | | | | | When refilling the FIFO with more TX data (using a new SPI transaction), the driver must prefix the TX data with a write to the FIFO I/O Register. This tells the trf7970a that the following data is destined for the FIFO so it can be transmitted. To accomplish this, the driver cannot simply push the prefix data just before the next set of TX data that is to be transmitted because that will overwrite part of the TX data provided by the digital layer. Instead, separate the prefix data and the TX data when calling trf7970a_transmit(). trf7970a_transmit() can then send the prefix and TX data from different memory locations with one spi_sync() operation. This also means that the driver doesn't require any skb "tx_headroom" as provided by the digital layer (see nfc_digital_allocate_device() and digital_skb_alloc()). Also ensure that the prefix is of type 'u8' and not 'char'. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Remove unnecessary FIFO reset & RSSI readMark A. Greer2014-09-07
| | | | | | | | | It is no longer necessary to reset the FIFO and read the 'RSSI Levels and Oscillator Status Register' so remove that code. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Clear possible spurious interrupt before transmittingMark A. Greer2014-09-07
| | | | | | | | | | The trf7970a occasionally generates spurious interrupts which can confuse the driver. To help alleviate this, clear any interrupts by reading the 'IRQ Status Register' before starting a new transaction. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Recalculate driver timeout valuesMark A. Greer2014-09-07
| | | | | | | | | | | | | | | | | | | | | | | Some of the timeout values used in the driver are not long enough to handle worst-case scenarios so they need to be recalculated. The time to wait for the FIFO to drain past the low-watermark is now 20 ms because it can take around 14.35 ms to send 95 bytes (127 bytes in full FIFO minus 32 bytes where the low-watermark interrupt will fire). 95 bytes will take around 14.35 ms at 6.62 kbps (the lowest supported bit rate used by ISO/IEC 15693) so 20 ms should be a safe value. The time to wait before issuing an EOF to complete an ISO/IEC 15693 write or lock command is 40 ms-- 20 ms to drain the FIFO and another 20 ms to ensure the wait is long enough before sending an EOF. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Add RF technology specific guard timesMark A. Greer2014-09-07
| | | | | | | | | | | | | | When turning on the RF field, the driver must wait an RF-technology-specific amount of time (known as the guard time) before modulating the field. Currently, the driver waits 5 ms but that is too short for NFCF and too long for ISO/IEC 15693. Fix this by determining the guard time when the RF technology is set and delaying that amount of time when turning on the RF field. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Initialize when enabling RFMark A. Greer2014-09-07
| | | | | | | | | | | Currently, the trf7970a is reset & initialized only when the pm_runtime resume hook is called. Instead, initialize it every time the RF is enabled to ensure that the trf7970a is quiesced and in a known state before being set up for another RF technology. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Disable SYS_CLK OutputMark A. Greer2014-09-07
| | | | | | | | | | | Currently, support for providing the external SYS_CLK signal on pin 27 is not supported so turn it off by writing to the 'Modulator and SYS_CLK Control' register immediately after reset. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Remove unnecessary sleepMark A. Greer2014-09-07
| | | | | | | | There is no need to sleep for 1-2 ms before transmitting a new command. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: FIFO Size is really 127 bytesMark A. Greer2014-09-07
| | | | | | | | | Despite what the manual says, the FIFO size on the trf7970a is really 127 bytes so make the code respect that. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Ignore Overflow bit in FIFO Status RegisterMark A. Greer2014-09-07
| | | | | | | | The Overflow bit in the 'FIFO Status Register' has proven to be untrustworthy so ignore it. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Use spi_sync() instead of spi_write_then_read()Mark A. Greer2014-09-07
| | | | | | | | To more efficiently handle long continuous reads, use spi_sync() instead of spi_write_then_read(). Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Call spi_setup() to configure SPI communicationMark A. Greer2014-09-07
| | | | | | | | | Call spi_setup() to configure SPI communication with the trf7970a. This will ensure that the correct SPI parameters are used. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Remove trf7970a_tg_listen_mdaa()Mark A. Greer2014-09-07
| | | | | | | | | Currently, the digital layer 'tg_listen_mdaa' hook is not used and it isn't necessary to have a stub routine so remove it. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Remove incorrect of_node_put() callMark A. Greer2014-09-07
| | | | | | | | | of_property_read_u32() does not take a reference to the specified OF node so don't call of_node_put() in trf7970a_get_autosuspend_delay(). Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Make gpio labels more readableMark A. Greer2014-08-31
| | | | | | | | | Make the labels for the two gpio enable lines more user friendly by prefixing them with the driver name. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Add quirk to keep EN2 lowMark A. Greer2014-08-31
| | | | | | | | | | | A bug has been discovered in the trf7970a where it will generate an RF field even in passive target mode when EN2 is asserted. To work around this, add support for the 'en2-rf-quirk' device tree property which indicates that EN2 must remain low. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Move IRQ Status Read quirk to device treeMark A. Greer2014-08-31
| | | | | | | | | | | | | | | | | | | | The quirk indicating whether the trf7970a has the "IRQ Status Read" erratum or not is currently implemented using the 'driver_data' member of the 'spi_device_id' structure. That requires the driver to be modified to turn the quirk off when a version of the trf7970a that doesn't have the erratum is being used. To fix that, create a new device tree property called 'irq-status-read-quirk' that indicates that the trf7970a being used has the erratum. While at it, rename 'TRF7970A_QUIRK_IRQ_STATUS_READ_ERRATA' to 'TRF7970A_QUIRK_IRQ_STATUS_READ' to make it less of an eyesore. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Add VIN voltage override supportMark A. Greer2014-08-31
| | | | | | | | | | | | | | | | | | | | | | The trf7970a driver uses the voltage from the power/regulator subsystem to determine what the voltage on the VIN pin is. Normally, this is the right thing to do but sometimes the board that the trf7970a is on may change the voltage. This is the case for the trf7970atb board from Texas Instruments where it boosts the VIN voltage from 3.3V to 5V (see http://www.ti.com/tool/trf7970atb). To handle this, add support for the 'vin-voltage-override' device tree property which overrides the voltage value given by the regulator subsystem. When the DT property is not present, the value from the regulator subsystem is used. The value of 'vin-voltage-override' is in uVolts. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Add support for Felica Type 3 tagsMark A. Greer2014-05-25
| | | | | | | | Add support for the Felica protocol and Type 3 tags. Both 212 and 424 kbps are supported. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Add support for the ISO/IEC 14443-B and Type 4B tagsMark A. Greer2014-04-21
| | | | | | | | | Now that the NFC digital layer has support for the ISO/IEC 14443-B protocol and type 4B tags, add the corresponding support to the trf7970a driver. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Add 'autosuspend-delay' DTS propertyMark A. Greer2014-04-21
| | | | | | | | | | The trf7970a driver currently uses a fixed autosuspend delay of 30 seconds. To enable users to customize the delay as they see fit, add support for the new 'autosuspend-delay' DTS property (part of the nfc node) which can override the default 30 seconds. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Don't return value from trf7970a_switch_rf_on()Mark A. Greer2014-04-21
| | | | | | | | trf7970a_switch_rf_on() no longer returns anything other than 0 so make it void and clean up the code that checks for errors when its called. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Add pm_runtime supportMark A. Greer2014-04-21
| | | | | | | | | | | | | | | | | Add pm_runtime support by moving the code that enables the trf7970a to the pm_runtime hook routines. The pm_runtime 'autosuspend' feature is used so that the device isn't disabled until at least 30 seconds have passed since trf7970a_switch_rf_off() was last called. The result is that when trf7970a_switch_rf_on() is called, the device will be enabled and initialized (if it isn't already). When trf7970a_switch_rf_off() is called, it will turn off the RF immediately but leave the device enabled for at least 30 seconds. If 30 seconds have passed and the pm_runtime facility decides to suspend the driver, the device will be disabled then. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Turn RF on after hardware is configuredMark A. Greer2014-04-21
| | | | | | | | | | The NFC digital layer calls the 'switch_rf' hook to turn the RF on before it configures the RF technology and framing. There is potential to confuse a tag doing it this way so don't enable the RF until the RF technology and initial framing have been configured. Signed-off-by: Mark A. Greer <mgreer@animalcreek.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
* NFC: trf7970a: Set correct Vin voltage in Chip Status Control registerMark A. Greer2014-04-21
| | | | | | | | | | 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>
* NFC: trf7970a: Allow different Modulator and SYS_CLK Control register valuesMark A. Greer2014-04-21
| | | | | | | | | | | | 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>
* NFC: trf7970a: Set 'Modulator and SYS_CLK Control' after 'ISO Control'Mark A. Greer2014-04-21
| | | | | | | | | | | | | 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>
* NFC: trf7970a: Only write 'ISO Control' when its changingMark A. Greer2014-04-21
| | | | | | | | | | 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>
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