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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * TI TRF7970a RFID/NFC Transceiver Driver
  *
  * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
  *
  * Author: Erick Macias <emacias@ti.com>
  * Author: Felipe Balbi <balbi@ti.com>
  * Author: Mark A. Greer <mgreer@animalcreek.com>
  */
 
 #include <linux/module.h>
 #include <linux/device.h>
 #include <linux/netdevice.h>
 #include <linux/interrupt.h>
 #include <linux/pm_runtime.h>
 #include <linux/nfc.h>
 #include <linux/skbuff.h>
 #include <linux/delay.h>
 #include <linux/gpio/consumer.h>
 #include <linux/of.h>
 #include <linux/spi/spi.h>
 #include <linux/regulator/consumer.h>
 
 #include <net/nfc/nfc.h>
 #include <net/nfc/digital.h>
 
 /* There are 3 ways the host can communicate with the trf7970a:
  * parallel mode, SPI with Slave Select (SS) mode, and SPI without
  * SS mode.  The driver only supports the two SPI modes.
  *
  * The trf7970a is very timing sensitive and the VIN, EN2, and EN
  * pins must asserted in that order and with specific delays in between.
  * The delays used in the driver were provided by TI and have been
  * confirmed to work with this driver.  There is a bug with the current
  * version of the trf7970a that requires that EN2 remain low no matter
  * what.  If it goes high, it will generate an RF field even when in
  * passive target mode.  TI has indicated that the chip will work okay
  * when EN2 is left low.  The 'en2-rf-quirk' device tree property
  * indicates that trf7970a currently being used has the erratum and
  * that EN2 must be kept low.
  *
  * Timeouts are implemented using the delayed workqueue kernel facility.
  * Timeouts are required so things don't hang when there is no response
  * from the trf7970a (or tag).  Using this mechanism creates a race with
  * interrupts, however.  That is, an interrupt and a timeout could occur
  * closely enough together that one is blocked by the mutex while the other
  * executes.  When the timeout handler executes first and blocks the
  * interrupt handler, it will eventually set the state to IDLE so the
  * interrupt handler will check the state and exit with no harm done.
  * When the interrupt handler executes first and blocks the timeout handler,
  * the cancel_delayed_work() call will know that it didn't cancel the
  * work item (i.e., timeout) and will return zero.  That return code is
  * used by the timer handler to indicate that it should ignore the timeout
  * once its unblocked.
  *
  * Aborting an active command isn't as simple as it seems because the only
  * way to abort a command that's already been sent to the tag is so turn
  * off power to the tag.  If we do that, though, we'd have to go through
  * the entire anticollision procedure again but the digital layer doesn't
  * support that.  So, if an abort is received before trf7970a_send_cmd()
  * has sent the command to the tag, it simply returns -ECANCELED.  If the
  * command has already been sent to the tag, then the driver continues
  * normally and recieves the response data (or error) but just before
  * sending the data upstream, it frees the rx_skb and sends -ECANCELED
  * upstream instead.  If the command failed, that error will be sent
  * upstream.
  *
  * When recieving data from a tag and the interrupt status register has
  * only the SRX bit set, it means that all of the data has been received
  * (once what's in the fifo has been read).  However, depending on timing
  * an interrupt status with only the SRX bit set may not be recived.  In
  * those cases, the timeout mechanism is used to wait 20 ms in case more
  * data arrives.  After 20 ms, it is assumed that all of the data has been
  * received and the accumulated rx data is sent upstream.  The
  * 'TRF7970A_ST_WAIT_FOR_RX_DATA_CONT' state is used for this purpose
  * (i.e., it indicates that some data has been received but we're not sure
  * if there is more coming so a timeout in this state means all data has
  * been received and there isn't an error).  The delay is 20 ms since delays
  * of ~16 ms have been observed during testing.
  *
  * When transmitting a frame larger than the FIFO size (127 bytes), the
  * driver will wait 20 ms for the FIFO to drain past the low-watermark
  * and generate an interrupt.  The low-watermark set to 32 bytes so the
  * interrupt should fire after 127 - 32 = 95 bytes have been sent.  At
  * the lowest possible bit rate (6.62 kbps for 15693), it will take up
  * to ~14.35 ms so 20 ms is used for the timeout.
  *
  * Type 2 write and sector select commands respond with a 4-bit ACK or NACK.
  * Having only 4 bits in the FIFO won't normally generate an interrupt so
  * driver enables the '4_bit_RX' bit of the Special Functions register 1
  * to cause an interrupt in that case.  Leaving that bit for a read command
  * messes up the data returned so it is only enabled when the framing is
  * 'NFC_DIGITAL_FRAMING_NFCA_T2T' and the command is not a read command.
  * Unfortunately, that means that the driver has to peek into tx frames
  * when the framing is 'NFC_DIGITAL_FRAMING_NFCA_T2T'.  This is done by
  * the trf7970a_per_cmd_config() routine.
  *
  * ISO/IEC 15693 frames specify whether to use single or double sub-carrier
  * frequencies and whether to use low or high data rates in the flags byte
  * of the frame.  This means that the driver has to peek at all 15693 frames
  * to determine what speed to set the communication to.  In addition, write
  * and lock commands use the OPTION flag to indicate that an EOF must be
  * sent to the tag before it will send its response.  So the driver has to
  * examine all frames for that reason too.
  *
  * It is unclear how long to wait before sending the EOF.  According to the
  * Note under Table 1-1 in section 1.6 of
  * http://www.ti.com/lit/ug/scbu011/scbu011.pdf, that wait should be at least
  * 10 ms for TI Tag-it HF-I tags; however testing has shown that is not long
  * enough so 20 ms is used.  So the timer is set to 40 ms - 20 ms to drain
  * up to 127 bytes in the FIFO at the lowest bit rate plus another 20 ms to
  * ensure the wait is long enough before sending the EOF.  This seems to work
  * reliably.
  */
 
 #define TRF7970A_SUPPORTED_PROTOCOLS \
         (NFC_PROTO_MIFARE_MASK | NFC_PROTO_ISO14443_MASK |  \
          NFC_PROTO_ISO14443_B_MASK | NFC_PROTO_FELICA_MASK | \
          NFC_PROTO_ISO15693_MASK | NFC_PROTO_NFC_DEP_MASK)
 
 #define TRF7970A_AUTOSUSPEND_DELAY      30000   /* 30 seconds */
 #define TRF7970A_13MHZ_CLOCK_FREQUENCY      13560000
 #define TRF7970A_27MHZ_CLOCK_FREQUENCY      27120000
 
 #define TRF7970A_RX_SKB_ALLOC_SIZE      256
 
 #define TRF7970A_FIFO_SIZE          127
 
 /* TX length is 3 nibbles long ==> 4KB - 1 bytes max */
 #define TRF7970A_TX_MAX             (4096 - 1)
 
 #define TRF7970A_WAIT_FOR_TX_IRQ        20
 #define TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT   20
 #define TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT    20
 #define TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF 40
 
 /* Guard times for various RF technologies (in us) */
 #define TRF7970A_GUARD_TIME_NFCA        5000
 #define TRF7970A_GUARD_TIME_NFCB        5000
 #define TRF7970A_GUARD_TIME_NFCF        20000
 #define TRF7970A_GUARD_TIME_15693       1000
 
 /* Quirks */
 /* Erratum: When reading IRQ Status register on trf7970a, we must issue a
  * read continuous command for IRQ Status and Collision Position registers.
  */
 #define TRF7970A_QUIRK_IRQ_STATUS_READ      BIT(0)
 #define TRF7970A_QUIRK_EN2_MUST_STAY_LOW    BIT(1)
 
 /* Direct commands */
 #define TRF7970A_CMD_IDLE           0x00
 #define TRF7970A_CMD_SOFT_INIT          0x03
 #define TRF7970A_CMD_RF_COLLISION       0x04
 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_N    0x05
 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_0    0x06
 #define TRF7970A_CMD_FIFO_RESET         0x0f
 #define TRF7970A_CMD_TRANSMIT_NO_CRC        0x10
 #define TRF7970A_CMD_TRANSMIT           0x11
 #define TRF7970A_CMD_DELAY_TRANSMIT_NO_CRC  0x12
 #define TRF7970A_CMD_DELAY_TRANSMIT     0x13
 #define TRF7970A_CMD_EOF            0x14
 #define TRF7970A_CMD_CLOSE_SLOT         0x15
 #define TRF7970A_CMD_BLOCK_RX           0x16
 #define TRF7970A_CMD_ENABLE_RX          0x17
 #define TRF7970A_CMD_TEST_INT_RF        0x18
 #define TRF7970A_CMD_TEST_EXT_RF        0x19
 #define TRF7970A_CMD_RX_GAIN_ADJUST     0x1a
 
 /* Bits determining whether its a direct command or register R/W,
  * whether to use a continuous SPI transaction or not, and the actual
  * direct cmd opcode or register address.
  */
 #define TRF7970A_CMD_BIT_CTRL           BIT(7)
 #define TRF7970A_CMD_BIT_RW         BIT(6)
 #define TRF7970A_CMD_BIT_CONTINUOUS     BIT(5)
 #define TRF7970A_CMD_BIT_OPCODE(opcode)     ((opcode) & 0x1f)
 
 /* Registers addresses */
 #define TRF7970A_CHIP_STATUS_CTRL       0x00
 #define TRF7970A_ISO_CTRL           0x01
 #define TRF7970A_ISO14443B_TX_OPTIONS       0x02
 #define TRF7970A_ISO14443A_HIGH_BITRATE_OPTIONS 0x03
 #define TRF7970A_TX_TIMER_SETTING_H_BYTE    0x04
 #define TRF7970A_TX_TIMER_SETTING_L_BYTE    0x05
 #define TRF7970A_TX_PULSE_LENGTH_CTRL       0x06
 #define TRF7970A_RX_NO_RESPONSE_WAIT        0x07
 #define TRF7970A_RX_WAIT_TIME           0x08
 #define TRF7970A_MODULATOR_SYS_CLK_CTRL     0x09
 #define TRF7970A_RX_SPECIAL_SETTINGS        0x0a
 #define TRF7970A_REG_IO_CTRL            0x0b
 #define TRF7970A_IRQ_STATUS         0x0c
 #define TRF7970A_COLLISION_IRQ_MASK     0x0d
 #define TRF7970A_COLLISION_POSITION     0x0e
 #define TRF7970A_RSSI_OSC_STATUS        0x0f
 #define TRF7970A_SPECIAL_FCN_REG1       0x10
 #define TRF7970A_SPECIAL_FCN_REG2       0x11
 #define TRF7970A_RAM1               0x12
 #define TRF7970A_RAM2               0x13
 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS  0x14
 #define TRF7970A_NFC_LOW_FIELD_LEVEL        0x16
 #define TRF7970A_NFCID1             0x17
 #define TRF7970A_NFC_TARGET_LEVEL       0x18
 #define TRF79070A_NFC_TARGET_PROTOCOL       0x19
 #define TRF7970A_TEST_REGISTER1         0x1a
 #define TRF7970A_TEST_REGISTER2         0x1b
 #define TRF7970A_FIFO_STATUS            0x1c
 #define TRF7970A_TX_LENGTH_BYTE1        0x1d
 #define TRF7970A_TX_LENGTH_BYTE2        0x1e
 #define TRF7970A_FIFO_IO_REGISTER       0x1f
 
 /* Chip Status Control Register Bits */
 #define TRF7970A_CHIP_STATUS_VRS5_3     BIT(0)
 #define TRF7970A_CHIP_STATUS_REC_ON     BIT(1)
 #define TRF7970A_CHIP_STATUS_AGC_ON     BIT(2)
 #define TRF7970A_CHIP_STATUS_PM_ON      BIT(3)
 #define TRF7970A_CHIP_STATUS_RF_PWR     BIT(4)
 #define TRF7970A_CHIP_STATUS_RF_ON      BIT(5)
 #define TRF7970A_CHIP_STATUS_DIRECT     BIT(6)
 #define TRF7970A_CHIP_STATUS_STBY       BIT(7)
 
 /* ISO Control Register Bits */
 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_662    0x00
 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_662  0x01
 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648   0x02
 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_2648 0x03
 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a   0x04
 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_667  0x05
 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669   0x06
 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_2669 0x07
 #define TRF7970A_ISO_CTRL_14443A_106        0x08
 #define TRF7970A_ISO_CTRL_14443A_212        0x09
 #define TRF7970A_ISO_CTRL_14443A_424        0x0a
 #define TRF7970A_ISO_CTRL_14443A_848        0x0b
 #define TRF7970A_ISO_CTRL_14443B_106        0x0c
 #define TRF7970A_ISO_CTRL_14443B_212        0x0d
 #define TRF7970A_ISO_CTRL_14443B_424        0x0e
 #define TRF7970A_ISO_CTRL_14443B_848        0x0f
 #define TRF7970A_ISO_CTRL_FELICA_212        0x1a
 #define TRF7970A_ISO_CTRL_FELICA_424        0x1b
 #define TRF7970A_ISO_CTRL_NFC_NFCA_106      0x01
 #define TRF7970A_ISO_CTRL_NFC_NFCF_212      0x02
 #define TRF7970A_ISO_CTRL_NFC_NFCF_424      0x03
 #define TRF7970A_ISO_CTRL_NFC_CE_14443A     0x00
 #define TRF7970A_ISO_CTRL_NFC_CE_14443B     0x01
 #define TRF7970A_ISO_CTRL_NFC_CE        BIT(2)
 #define TRF7970A_ISO_CTRL_NFC_ACTIVE        BIT(3)
 #define TRF7970A_ISO_CTRL_NFC_INITIATOR     BIT(4)
 #define TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE   BIT(5)
 #define TRF7970A_ISO_CTRL_RFID          BIT(5)
 #define TRF7970A_ISO_CTRL_DIR_MODE      BIT(6)
 #define TRF7970A_ISO_CTRL_RX_CRC_N      BIT(7)  /* true == No CRC */
 
 #define TRF7970A_ISO_CTRL_RFID_SPEED_MASK   0x1f
 
 /* Modulator and SYS_CLK Control Register Bits */
 #define TRF7970A_MODULATOR_DEPTH(n)     ((n) & 0x7)
 #define TRF7970A_MODULATOR_DEPTH_ASK10      (TRF7970A_MODULATOR_DEPTH(0))
 #define TRF7970A_MODULATOR_DEPTH_OOK        (TRF7970A_MODULATOR_DEPTH(1))
 #define TRF7970A_MODULATOR_DEPTH_ASK7       (TRF7970A_MODULATOR_DEPTH(2))
 #define TRF7970A_MODULATOR_DEPTH_ASK8_5     (TRF7970A_MODULATOR_DEPTH(3))
 #define TRF7970A_MODULATOR_DEPTH_ASK13      (TRF7970A_MODULATOR_DEPTH(4))
 #define TRF7970A_MODULATOR_DEPTH_ASK16      (TRF7970A_MODULATOR_DEPTH(5))
 #define TRF7970A_MODULATOR_DEPTH_ASK22      (TRF7970A_MODULATOR_DEPTH(6))
 #define TRF7970A_MODULATOR_DEPTH_ASK30      (TRF7970A_MODULATOR_DEPTH(7))
 #define TRF7970A_MODULATOR_EN_ANA       BIT(3)
 #define TRF7970A_MODULATOR_CLK(n)       (((n) & 0x3) << 4)
 #define TRF7970A_MODULATOR_CLK_DISABLED     (TRF7970A_MODULATOR_CLK(0))
 #define TRF7970A_MODULATOR_CLK_3_6      (TRF7970A_MODULATOR_CLK(1))
 #define TRF7970A_MODULATOR_CLK_6_13     (TRF7970A_MODULATOR_CLK(2))
 #define TRF7970A_MODULATOR_CLK_13_27        (TRF7970A_MODULATOR_CLK(3))
 #define TRF7970A_MODULATOR_EN_OOK       BIT(6)
 #define TRF7970A_MODULATOR_27MHZ        BIT(7)
 
 #define TRF7970A_RX_SPECIAL_SETTINGS_NO_LIM BIT(0)
 #define TRF7970A_RX_SPECIAL_SETTINGS_AGCR   BIT(1)
 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_0DB (0x0 << 2)
 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_5DB (0x1 << 2)
 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_10DB    (0x2 << 2)
 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_15DB    (0x3 << 2)
 #define TRF7970A_RX_SPECIAL_SETTINGS_HBT    BIT(4)
 #define TRF7970A_RX_SPECIAL_SETTINGS_M848   BIT(5)
 #define TRF7970A_RX_SPECIAL_SETTINGS_C424   BIT(6)
 #define TRF7970A_RX_SPECIAL_SETTINGS_C212   BIT(7)
 
 #define TRF7970A_REG_IO_CTRL_VRS(v)     ((v) & 0x07)
 #define TRF7970A_REG_IO_CTRL_IO_LOW     BIT(5)
 #define TRF7970A_REG_IO_CTRL_EN_EXT_PA      BIT(6)
 #define TRF7970A_REG_IO_CTRL_AUTO_REG       BIT(7)
 
 /* IRQ Status Register Bits */
 #define TRF7970A_IRQ_STATUS_NORESP      BIT(0)  /* ISO15693 only */
 #define TRF7970A_IRQ_STATUS_NFC_COL_ERROR   BIT(0)
 #define TRF7970A_IRQ_STATUS_COL         BIT(1)
 #define TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR   BIT(2)
 #define TRF7970A_IRQ_STATUS_NFC_RF      BIT(2)
 #define TRF7970A_IRQ_STATUS_PARITY_ERROR    BIT(3)
 #define TRF7970A_IRQ_STATUS_NFC_SDD     BIT(3)
 #define TRF7970A_IRQ_STATUS_CRC_ERROR       BIT(4)
 #define TRF7970A_IRQ_STATUS_NFC_PROTO_ERROR BIT(4)
 #define TRF7970A_IRQ_STATUS_FIFO        BIT(5)
 #define TRF7970A_IRQ_STATUS_SRX         BIT(6)
 #define TRF7970A_IRQ_STATUS_TX          BIT(7)
 
 #define TRF7970A_IRQ_STATUS_ERROR               \
         (TRF7970A_IRQ_STATUS_COL |          \
          TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR |    \
          TRF7970A_IRQ_STATUS_PARITY_ERROR |     \
          TRF7970A_IRQ_STATUS_CRC_ERROR)
 
 #define TRF7970A_RSSI_OSC_STATUS_RSSI_MASK  (BIT(2) | BIT(1) | BIT(0))
 #define TRF7970A_RSSI_OSC_STATUS_RSSI_X_MASK    (BIT(5) | BIT(4) | BIT(3))
 #define TRF7970A_RSSI_OSC_STATUS_RSSI_OSC_OK    BIT(6)
 
 #define TRF7970A_SPECIAL_FCN_REG1_COL_7_6       BIT(0)
 #define TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL       BIT(1)
 #define TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX      BIT(2)
 #define TRF7970A_SPECIAL_FCN_REG1_SP_DIR_MODE       BIT(3)
 #define TRF7970A_SPECIAL_FCN_REG1_NEXT_SLOT_37US    BIT(4)
 #define TRF7970A_SPECIAL_FCN_REG1_PAR43         BIT(5)
 
 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_124  (0x0 << 2)
 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_120  (0x1 << 2)
 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_112  (0x2 << 2)
 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96   (0x3 << 2)
 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_4    0x0
 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_8    0x1
 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_16   0x2
 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32   0x3
 
 #define TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(v)   ((v) & 0x07)
 #define TRF7970A_NFC_LOW_FIELD_LEVEL_CLEX_DIS   BIT(7)
 
 #define TRF7970A_NFC_TARGET_LEVEL_RFDET(v)  ((v) & 0x07)
 #define TRF7970A_NFC_TARGET_LEVEL_HI_RF     BIT(3)
 #define TRF7970A_NFC_TARGET_LEVEL_SDD_EN    BIT(5)
 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_4BYTES   (0x0 << 6)
 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_7BYTES   (0x1 << 6)
 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_10BYTES  (0x2 << 6)
 
 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106     BIT(0)
 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212     BIT(1)
 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424     (BIT(0) | BIT(1))
 #define TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B    BIT(2)
 #define TRF79070A_NFC_TARGET_PROTOCOL_PAS_106       BIT(3)
 #define TRF79070A_NFC_TARGET_PROTOCOL_FELICA        BIT(4)
 #define TRF79070A_NFC_TARGET_PROTOCOL_RF_L      BIT(6)
 #define TRF79070A_NFC_TARGET_PROTOCOL_RF_H      BIT(7)
 
 #define TRF79070A_NFC_TARGET_PROTOCOL_106A      \
      (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |      \
       TRF79070A_NFC_TARGET_PROTOCOL_RF_L |      \
       TRF79070A_NFC_TARGET_PROTOCOL_PAS_106 |   \
       TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
 
 #define TRF79070A_NFC_TARGET_PROTOCOL_106B      \
      (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |      \
       TRF79070A_NFC_TARGET_PROTOCOL_RF_L |      \
       TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B |    \
       TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
 
 #define TRF79070A_NFC_TARGET_PROTOCOL_212F      \
      (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |      \
       TRF79070A_NFC_TARGET_PROTOCOL_RF_L |      \
       TRF79070A_NFC_TARGET_PROTOCOL_FELICA |    \
       TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212)
 
 #define TRF79070A_NFC_TARGET_PROTOCOL_424F      \
      (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |      \
       TRF79070A_NFC_TARGET_PROTOCOL_RF_L |      \
       TRF79070A_NFC_TARGET_PROTOCOL_FELICA |    \
       TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424)
 
 #define TRF7970A_FIFO_STATUS_OVERFLOW       BIT(7)
 
 /* NFC (ISO/IEC 14443A) Type 2 Tag commands */
 #define NFC_T2T_CMD_READ            0x30
 
 /* ISO 15693 commands codes */
 #define ISO15693_CMD_INVENTORY          0x01
 #define ISO15693_CMD_READ_SINGLE_BLOCK      0x20
 #define ISO15693_CMD_WRITE_SINGLE_BLOCK     0x21
 #define ISO15693_CMD_LOCK_BLOCK         0x22
 #define ISO15693_CMD_READ_MULTIPLE_BLOCK    0x23
 #define ISO15693_CMD_WRITE_MULTIPLE_BLOCK   0x24
 #define ISO15693_CMD_SELECT         0x25
 #define ISO15693_CMD_RESET_TO_READY     0x26
 #define ISO15693_CMD_WRITE_AFI          0x27
 #define ISO15693_CMD_LOCK_AFI           0x28
 #define ISO15693_CMD_WRITE_DSFID        0x29
 #define ISO15693_CMD_LOCK_DSFID         0x2a
 #define ISO15693_CMD_GET_SYSTEM_INFO        0x2b
 #define ISO15693_CMD_GET_MULTIPLE_BLOCK_SECURITY_STATUS 0x2c
 
 /* ISO 15693 request and response flags */
 #define ISO15693_REQ_FLAG_SUB_CARRIER       BIT(0)
 #define ISO15693_REQ_FLAG_DATA_RATE     BIT(1)
 #define ISO15693_REQ_FLAG_INVENTORY     BIT(2)
 #define ISO15693_REQ_FLAG_PROTOCOL_EXT      BIT(3)
 #define ISO15693_REQ_FLAG_SELECT        BIT(4)
 #define ISO15693_REQ_FLAG_AFI           BIT(4)
 #define ISO15693_REQ_FLAG_ADDRESS       BIT(5)
 #define ISO15693_REQ_FLAG_NB_SLOTS      BIT(5)
 #define ISO15693_REQ_FLAG_OPTION        BIT(6)
 
 #define ISO15693_REQ_FLAG_SPEED_MASK \
         (ISO15693_REQ_FLAG_SUB_CARRIER | ISO15693_REQ_FLAG_DATA_RATE)
 
 enum trf7970a_state {
     TRF7970A_ST_PWR_OFF,
     TRF7970A_ST_RF_OFF,
     TRF7970A_ST_IDLE,
     TRF7970A_ST_IDLE_RX_BLOCKED,
     TRF7970A_ST_WAIT_FOR_TX_FIFO,
     TRF7970A_ST_WAIT_FOR_RX_DATA,
     TRF7970A_ST_WAIT_FOR_RX_DATA_CONT,
     TRF7970A_ST_WAIT_TO_ISSUE_EOF,
     TRF7970A_ST_LISTENING,
     TRF7970A_ST_LISTENING_MD,
     TRF7970A_ST_MAX
 };
 
 struct trf7970a {
     enum trf7970a_state     state;
     struct device           *dev;
     struct spi_device       *spi;
     struct regulator        *regulator;
     struct nfc_digital_dev      *ddev;
     u32             quirks;
     bool                is_initiator;
     bool                aborting;
     struct sk_buff          *tx_skb;
     struct sk_buff          *rx_skb;
     nfc_digital_cmd_complete_t  cb;
     void                *cb_arg;
     u8              chip_status_ctrl;
     u8              iso_ctrl;
     u8              iso_ctrl_tech;
     u8              modulator_sys_clk_ctrl;
     u8              special_fcn_reg1;
     u8              io_ctrl;
     unsigned int            guard_time;
     int             technology;
     int             framing;
     u8              md_rf_tech;
     u8              tx_cmd;
     bool                issue_eof;
     struct gpio_desc        *en_gpiod;
     struct gpio_desc        *en2_gpiod;
     struct mutex            lock;
     unsigned int            timeout;
     bool                ignore_timeout;
     struct delayed_work     timeout_work;
 };
 
 static int trf7970a_cmd(struct trf7970a *trf, u8 opcode)
 {
     u8 cmd = TRF7970A_CMD_BIT_CTRL | TRF7970A_CMD_BIT_OPCODE(opcode);
     int ret;
 
     dev_dbg(trf->dev, "cmd: 0x%x\n", cmd);
 
     ret = spi_write(trf->spi, &cmd, 1);
     if (ret)
         dev_err(trf->dev, "%s - cmd: 0x%x, ret: %d\n", __func__, cmd,
             ret);
     return ret;
 }
 
 static int trf7970a_read(struct trf7970a *trf, u8 reg, u8 *val)
 {
     u8 addr = TRF7970A_CMD_BIT_RW | reg;
     int ret;
 
     ret = spi_write_then_read(trf->spi, &addr, 1, val, 1);
     if (ret)
         dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
             ret);
 
     dev_dbg(trf->dev, "read(0x%x): 0x%x\n", addr, *val);
 
     return ret;
 }
 
 static int trf7970a_read_cont(struct trf7970a *trf, u8 reg, u8 *buf,
                   size_t len)
 {
     u8 addr = reg | TRF7970A_CMD_BIT_RW | TRF7970A_CMD_BIT_CONTINUOUS;
     struct spi_transfer t[2];
     struct spi_message m;
     int ret;
 
     dev_dbg(trf->dev, "read_cont(0x%x, %zd)\n", addr, len);
 
     spi_message_init(&m);
 
     memset(&t, 0, sizeof(t));
 
     t[0].tx_buf = &addr;
     t[0].len = sizeof(addr);
     spi_message_add_tail(&t[0], &m);
 
     t[1].rx_buf = buf;
     t[1].len = len;
     spi_message_add_tail(&t[1], &m);
 
     ret = spi_sync(trf->spi, &m);
     if (ret)
         dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
             ret);
     return ret;
 }
 
 static int trf7970a_write(struct trf7970a *trf, u8 reg, u8 val)
 {
     u8 buf[2] = { reg, val };
     int ret;
 
     dev_dbg(trf->dev, "write(0x%x): 0x%x\n", reg, val);
 
     ret = spi_write(trf->spi, buf, 2);
     if (ret)
         dev_err(trf->dev, "%s - write: 0x%x 0x%x, ret: %d\n", __func__,
             buf[0], buf[1], ret);
 
     return ret;
 }
 
 static int trf7970a_read_irqstatus(struct trf7970a *trf, u8 *status)
 {
     int ret;
     u8 buf[2];
     u8 addr;
 
     addr = TRF7970A_IRQ_STATUS | TRF7970A_CMD_BIT_RW;
 
     if (trf->quirks & TRF7970A_QUIRK_IRQ_STATUS_READ) {
         addr |= TRF7970A_CMD_BIT_CONTINUOUS;
         ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
     } else {
         ret = spi_write_then_read(trf->spi, &addr, 1, buf, 1);
     }
 
     if (ret)
         dev_err(trf->dev, "%s - irqstatus: Status read failed: %d\n",
             __func__, ret);
     else
         *status = buf[0];
 
     return ret;
 }
 
 static int trf7970a_read_target_proto(struct trf7970a *trf, u8 *target_proto)
 {
     int ret;
     u8 buf[2];
     u8 addr;
 
     addr = TRF79070A_NFC_TARGET_PROTOCOL | TRF7970A_CMD_BIT_RW |
            TRF7970A_CMD_BIT_CONTINUOUS;
 
     ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
     if (ret)
         dev_err(trf->dev, "%s - target_proto: Read failed: %d\n",
             __func__, ret);
     else
         *target_proto = buf[0];
 
     return ret;
 }
 
 static int trf7970a_mode_detect(struct trf7970a *trf, u8 *rf_tech)
 {
     int ret;
     u8 target_proto, tech;
 
     ret = trf7970a_read_target_proto(trf, &target_proto);
     if (ret)
         return ret;
 
     switch (target_proto) {
     case TRF79070A_NFC_TARGET_PROTOCOL_106A:
         tech = NFC_DIGITAL_RF_TECH_106A;
         break;
     case TRF79070A_NFC_TARGET_PROTOCOL_106B:
         tech = NFC_DIGITAL_RF_TECH_106B;
         break;
     case TRF79070A_NFC_TARGET_PROTOCOL_212F:
         tech = NFC_DIGITAL_RF_TECH_212F;
         break;
     case TRF79070A_NFC_TARGET_PROTOCOL_424F:
         tech = NFC_DIGITAL_RF_TECH_424F;
         break;
     default:
         dev_dbg(trf->dev, "%s - mode_detect: target_proto: 0x%x\n",
             __func__, target_proto);
         return -EIO;
     }
 
     *rf_tech = tech;
 
     return ret;
 }
 
 static void trf7970a_send_upstream(struct trf7970a *trf)
 {
     dev_kfree_skb_any(trf->tx_skb);
     trf->tx_skb = NULL;
 
     if (trf->rx_skb && !IS_ERR(trf->rx_skb) && !trf->aborting)
         print_hex_dump_debug("trf7970a rx data: ", DUMP_PREFIX_NONE,
                      16, 1, trf->rx_skb->data, trf->rx_skb->len,
                      false);
 
     trf->state = TRF7970A_ST_IDLE;
 
     if (trf->aborting) {
         dev_dbg(trf->dev, "Abort process complete\n");
 
         if (!IS_ERR(trf->rx_skb)) {
             kfree_skb(trf->rx_skb);
             trf->rx_skb = ERR_PTR(-ECANCELED);
         }
 
         trf->aborting = false;
     }
 
     trf->cb(trf->ddev, trf->cb_arg, trf->rx_skb);
 
     trf->rx_skb = NULL;
 }
 
 static void trf7970a_send_err_upstream(struct trf7970a *trf, int errno)
 {
     dev_dbg(trf->dev, "Error - state: %d, errno: %d\n", trf->state, errno);
 
     cancel_delayed_work(&trf->timeout_work);
 
     kfree_skb(trf->rx_skb);
     trf->rx_skb = ERR_PTR(errno);
 
     trf7970a_send_upstream(trf);
 }
 
 static int trf7970a_transmit(struct trf7970a *trf, struct sk_buff *skb,
                  unsigned int len, const u8 *prefix,
                  unsigned int prefix_len)
 {
     struct spi_transfer t[2];
     struct spi_message m;
     unsigned int timeout;
     int ret;
 
     print_hex_dump_debug("trf7970a tx data: ", DUMP_PREFIX_NONE,
                  16, 1, skb->data, len, false);
 
     spi_message_init(&m);
 
     memset(&t, 0, sizeof(t));
 
     t[0].tx_buf = prefix;
     t[0].len = prefix_len;
     spi_message_add_tail(&t[0], &m);
 
     t[1].tx_buf = skb->data;
     t[1].len = len;
     spi_message_add_tail(&t[1], &m);
 
     ret = spi_sync(trf->spi, &m);
     if (ret) {
         dev_err(trf->dev, "%s - Can't send tx data: %d\n", __func__,
             ret);
         return ret;
     }
 
     skb_pull(skb, len);
 
     if (skb->len > 0) {
         trf->state = TRF7970A_ST_WAIT_FOR_TX_FIFO;
         timeout = TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT;
     } else {
         if (trf->issue_eof) {
             trf->state = TRF7970A_ST_WAIT_TO_ISSUE_EOF;
             timeout = TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF;
         } else {
             trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
 
             if (!trf->timeout)
                 timeout = TRF7970A_WAIT_FOR_TX_IRQ;
             else
                 timeout = trf->timeout;
         }
     }
 
     dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n", timeout,
         trf->state);
 
     schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
 
     return 0;
 }
 
 static void trf7970a_fill_fifo(struct trf7970a *trf)
 {
     struct sk_buff *skb = trf->tx_skb;
     unsigned int len;
     int ret;
     u8 fifo_bytes;
     u8 prefix;
 
     ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
     if (ret) {
         trf7970a_send_err_upstream(trf, ret);
         return;
     }
 
     dev_dbg(trf->dev, "Filling FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
 
     fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 
     /* Calculate how much more data can be written to the fifo */
     len = TRF7970A_FIFO_SIZE - fifo_bytes;
     if (!len) {
         schedule_delayed_work(&trf->timeout_work,
             msecs_to_jiffies(TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT));
         return;
     }
 
     len = min(skb->len, len);
 
     prefix = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_FIFO_IO_REGISTER;
 
     ret = trf7970a_transmit(trf, skb, len, &prefix, sizeof(prefix));
     if (ret)
         trf7970a_send_err_upstream(trf, ret);
 }
 
 static void trf7970a_drain_fifo(struct trf7970a *trf, u8 status)
 {
     struct sk_buff *skb = trf->rx_skb;
     int ret;
     u8 fifo_bytes;
 
     if (status & TRF7970A_IRQ_STATUS_ERROR) {
         trf7970a_send_err_upstream(trf, -EIO);
         return;
     }
 
     ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
     if (ret) {
         trf7970a_send_err_upstream(trf, ret);
         return;
     }
 
     dev_dbg(trf->dev, "Draining FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
 
     fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 
     if (!fifo_bytes)
         goto no_rx_data;
 
     if (fifo_bytes > skb_tailroom(skb)) {
         skb = skb_copy_expand(skb, skb_headroom(skb),
                       max_t(int, fifo_bytes,
                         TRF7970A_RX_SKB_ALLOC_SIZE),
                       GFP_KERNEL);
         if (!skb) {
             trf7970a_send_err_upstream(trf, -ENOMEM);
             return;
         }
 
         kfree_skb(trf->rx_skb);
         trf->rx_skb = skb;
     }
 
     ret = trf7970a_read_cont(trf, TRF7970A_FIFO_IO_REGISTER,
                  skb_put(skb, fifo_bytes), fifo_bytes);
     if (ret) {
         trf7970a_send_err_upstream(trf, ret);
         return;
     }
 
     /* If received Type 2 ACK/NACK, shift right 4 bits and pass up */
     if ((trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T) && (skb->len == 1) &&
         (trf->special_fcn_reg1 == TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX)) {
         skb->data[0] >>= 4;
         status = TRF7970A_IRQ_STATUS_SRX;
     } else {
         trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA_CONT;
 
         ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
         if (ret) {
             trf7970a_send_err_upstream(trf, ret);
             return;
         }
 
         fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 
         /* If there are bytes in the FIFO, set status to '0' so
          * the if stmt below doesn't fire and the driver will wait
          * for the trf7970a to generate another RX interrupt.
          */
         if (fifo_bytes)
             status = 0;
     }
 
 no_rx_data:
     if (status == TRF7970A_IRQ_STATUS_SRX) {    /* Receive complete */
         trf7970a_send_upstream(trf);
         return;
     }
 
     dev_dbg(trf->dev, "Setting timeout for %d ms\n",
         TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT);
 
     schedule_delayed_work(&trf->timeout_work,
                msecs_to_jiffies(TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT));
 }
 
 static irqreturn_t trf7970a_irq(int irq, void *dev_id)
 {
     struct trf7970a *trf = dev_id;
     int ret;
     u8 status, fifo_bytes, iso_ctrl;
 
     mutex_lock(&trf->lock);
 
     if (trf->state == TRF7970A_ST_RF_OFF) {
         mutex_unlock(&trf->lock);
         return IRQ_NONE;
     }
 
     ret = trf7970a_read_irqstatus(trf, &status);
     if (ret) {
         mutex_unlock(&trf->lock);
         return IRQ_NONE;
     }
 
     dev_dbg(trf->dev, "IRQ - state: %d, status: 0x%x\n", trf->state,
         status);
 
     if (!status) {
         mutex_unlock(&trf->lock);
         return IRQ_NONE;
     }
 
     switch (trf->state) {
     case TRF7970A_ST_IDLE:
     case TRF7970A_ST_IDLE_RX_BLOCKED:
         /* If initiator and getting interrupts caused by RF noise,
          * turn off the receiver to avoid unnecessary interrupts.
          * It will be turned back on in trf7970a_send_cmd() when
          * the next command is issued.
          */
         if (trf->is_initiator && (status & TRF7970A_IRQ_STATUS_ERROR)) {
             trf7970a_cmd(trf, TRF7970A_CMD_BLOCK_RX);
             trf->state = TRF7970A_ST_IDLE_RX_BLOCKED;
         }
 
         trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
         break;
     case TRF7970A_ST_WAIT_FOR_TX_FIFO:
         if (status & TRF7970A_IRQ_STATUS_TX) {
             trf->ignore_timeout =
                 !cancel_delayed_work(&trf->timeout_work);
             trf7970a_fill_fifo(trf);
         } else {
             trf7970a_send_err_upstream(trf, -EIO);
         }
         break;
     case TRF7970A_ST_WAIT_FOR_RX_DATA:
     case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
         if (status & TRF7970A_IRQ_STATUS_SRX) {
             trf->ignore_timeout =
                 !cancel_delayed_work(&trf->timeout_work);
             trf7970a_drain_fifo(trf, status);
         } else if (status & TRF7970A_IRQ_STATUS_FIFO) {
             ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS,
                         &fifo_bytes);
 
             fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 
             if (ret)
                 trf7970a_send_err_upstream(trf, ret);
             else if (!fifo_bytes)
                 trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
         } else if ((status == TRF7970A_IRQ_STATUS_TX) ||
                (!trf->is_initiator &&
                 (status == (TRF7970A_IRQ_STATUS_TX |
                     TRF7970A_IRQ_STATUS_NFC_RF)))) {
             trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 
             if (!trf->timeout) {
                 trf->ignore_timeout =
                     !cancel_delayed_work(&trf->timeout_work);
                 trf->rx_skb = ERR_PTR(0);
                 trf7970a_send_upstream(trf);
                 break;
             }
 
             if (trf->is_initiator)
                 break;
 
             iso_ctrl = trf->iso_ctrl;
 
             switch (trf->framing) {
             case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
                 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
                 trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
                 break;
             case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
                 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
                 trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
                 break;
             case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
                 ret = trf7970a_write(trf,
                      TRF7970A_SPECIAL_FCN_REG1,
                      TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL);
                 if (ret)
                     goto err_unlock_exit;
 
                 trf->special_fcn_reg1 =
                     TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL;
                 break;
             default:
                 break;
             }
 
             if (iso_ctrl != trf->iso_ctrl) {
                 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
                              iso_ctrl);
                 if (ret)
                     goto err_unlock_exit;
 
                 trf->iso_ctrl = iso_ctrl;
             }
         } else {
             trf7970a_send_err_upstream(trf, -EIO);
         }
         break;
     case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
         if (status != TRF7970A_IRQ_STATUS_TX)
             trf7970a_send_err_upstream(trf, -EIO);
         break;
     case TRF7970A_ST_LISTENING:
         if (status & TRF7970A_IRQ_STATUS_SRX) {
             trf->ignore_timeout =
                 !cancel_delayed_work(&trf->timeout_work);
             trf7970a_drain_fifo(trf, status);
         } else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
             trf7970a_send_err_upstream(trf, -EIO);
         }
         break;
     case TRF7970A_ST_LISTENING_MD:
         if (status & TRF7970A_IRQ_STATUS_SRX) {
             trf->ignore_timeout =
                 !cancel_delayed_work(&trf->timeout_work);
 
             ret = trf7970a_mode_detect(trf, &trf->md_rf_tech);
             if (ret) {
                 trf7970a_send_err_upstream(trf, ret);
             } else {
                 trf->state = TRF7970A_ST_LISTENING;
                 trf7970a_drain_fifo(trf, status);
             }
         } else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
             trf7970a_send_err_upstream(trf, -EIO);
         }
         break;
     default:
         dev_err(trf->dev, "%s - Driver in invalid state: %d\n",
             __func__, trf->state);
     }
 
 err_unlock_exit:
     mutex_unlock(&trf->lock);
     return IRQ_HANDLED;
 }
 
 static void trf7970a_issue_eof(struct trf7970a *trf)
 {
     int ret;
 
     dev_dbg(trf->dev, "Issuing EOF\n");
 
     ret = trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
     if (ret)
         trf7970a_send_err_upstream(trf, ret);
 
     ret = trf7970a_cmd(trf, TRF7970A_CMD_EOF);
     if (ret)
         trf7970a_send_err_upstream(trf, ret);
 
     trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
 
     dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n",
         trf->timeout, trf->state);
 
     schedule_delayed_work(&trf->timeout_work,
                   msecs_to_jiffies(trf->timeout));
 }
 
 static void trf7970a_timeout_work_handler(struct work_struct *work)
 {
     struct trf7970a *trf = container_of(work, struct trf7970a,
                         timeout_work.work);
 
     dev_dbg(trf->dev, "Timeout - state: %d, ignore_timeout: %d\n",
         trf->state, trf->ignore_timeout);
 
     mutex_lock(&trf->lock);
 
     if (trf->ignore_timeout)
         trf->ignore_timeout = false;
     else if (trf->state == TRF7970A_ST_WAIT_FOR_RX_DATA_CONT)
         trf7970a_drain_fifo(trf, TRF7970A_IRQ_STATUS_SRX);
     else if (trf->state == TRF7970A_ST_WAIT_TO_ISSUE_EOF)
         trf7970a_issue_eof(trf);
     else
         trf7970a_send_err_upstream(trf, -ETIMEDOUT);
 
     mutex_unlock(&trf->lock);
 }
 
 static int trf7970a_init(struct trf7970a *trf)
 {
     int ret;
 
     dev_dbg(trf->dev, "Initializing device - state: %d\n", trf->state);
 
     ret = trf7970a_cmd(trf, TRF7970A_CMD_SOFT_INIT);
     if (ret)
         goto err_out;
 
     ret = trf7970a_cmd(trf, TRF7970A_CMD_IDLE);
     if (ret)
         goto err_out;
 
     ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
                  trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
     if (ret)
         goto err_out;
 
     ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
     if (ret)
         goto err_out;
 
     usleep_range(1000, 2000);
 
     trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
 
     ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
                  trf->modulator_sys_clk_ctrl);
     if (ret)
         goto err_out;
 
     ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS,
                  TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 |
                  TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32);
     if (ret)
         goto err_out;
 
     ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1, 0);
     if (ret)
         goto err_out;
 
     trf->special_fcn_reg1 = 0;
 
     trf->iso_ctrl = 0xff;
     return 0;
 
 err_out:
     dev_dbg(trf->dev, "Couldn't init device: %d\n", ret);
     return ret;
 }
 
 static void trf7970a_switch_rf_off(struct trf7970a *trf)
 {
     if ((trf->state == TRF7970A_ST_PWR_OFF) ||
         (trf->state == TRF7970A_ST_RF_OFF))
         return;
 
     dev_dbg(trf->dev, "Switching rf off\n");
 
     trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
 
     trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, trf->chip_status_ctrl);
 
     trf->aborting = false;
     trf->state = TRF7970A_ST_RF_OFF;
 
     pm_runtime_mark_last_busy(trf->dev);
     pm_runtime_put_autosuspend(trf->dev);
 }
 
 static int trf7970a_switch_rf_on(struct trf7970a *trf)
 {
     int ret;
 
     dev_dbg(trf->dev, "Switching rf on\n");
 
     pm_runtime_get_sync(trf->dev);
 
     if (trf->state != TRF7970A_ST_RF_OFF) { /* Power on, RF off */
         dev_err(trf->dev, "%s - Incorrect state: %d\n", __func__,
             trf->state);
         return -EINVAL;
     }
 
     ret = trf7970a_init(trf);
     if (ret) {
         dev_err(trf->dev, "%s - Can't initialize: %d\n", __func__, ret);
         return ret;
     }
 
     trf->state = TRF7970A_ST_IDLE;
 
     return 0;
 }
 
 static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on)
 {
     struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
     int ret = 0;
 
     dev_dbg(trf->dev, "Switching RF - state: %d, on: %d\n", trf->state, on);
 
     mutex_lock(&trf->lock);
 
     if (on) {
         switch (trf->state) {
         case TRF7970A_ST_PWR_OFF:
         case TRF7970A_ST_RF_OFF:
             ret = trf7970a_switch_rf_on(trf);
             break;
         case TRF7970A_ST_IDLE:
         case TRF7970A_ST_IDLE_RX_BLOCKED:
             break;
         default:
             dev_err(trf->dev, "%s - Invalid request: %d %d\n",
                 __func__, trf->state, on);
             trf7970a_switch_rf_off(trf);
             ret = -EINVAL;
         }
     } else {
         switch (trf->state) {
         case TRF7970A_ST_PWR_OFF:
         case TRF7970A_ST_RF_OFF:
             break;
         default:
             dev_err(trf->dev, "%s - Invalid request: %d %d\n",
                 __func__, trf->state, on);
             ret = -EINVAL;
             fallthrough;
         case TRF7970A_ST_IDLE:
         case TRF7970A_ST_IDLE_RX_BLOCKED:
         case TRF7970A_ST_WAIT_FOR_RX_DATA:
         case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
             trf7970a_switch_rf_off(trf);
         }
     }
 
     mutex_unlock(&trf->lock);
     return ret;
 }
 
 static int trf7970a_in_config_rf_tech(struct trf7970a *trf, int tech)
 {
     int ret = 0;
 
     dev_dbg(trf->dev, "rf technology: %d\n", tech);
 
     switch (tech) {
     case NFC_DIGITAL_RF_TECH_106A:
         trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443A_106;
         trf->modulator_sys_clk_ctrl =
             (trf->modulator_sys_clk_ctrl & 0xf8) |
             TRF7970A_MODULATOR_DEPTH_OOK;
         trf->guard_time = TRF7970A_GUARD_TIME_NFCA;
         break;
     case NFC_DIGITAL_RF_TECH_106B:
         trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443B_106;
         trf->modulator_sys_clk_ctrl =
             (trf->modulator_sys_clk_ctrl & 0xf8) |
             TRF7970A_MODULATOR_DEPTH_ASK10;
         trf->guard_time = TRF7970A_GUARD_TIME_NFCB;
         break;
     case NFC_DIGITAL_RF_TECH_212F:
         trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_212;
         trf->modulator_sys_clk_ctrl =
             (trf->modulator_sys_clk_ctrl & 0xf8) |
             TRF7970A_MODULATOR_DEPTH_ASK10;
         trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
         break;
     case NFC_DIGITAL_RF_TECH_424F:
         trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_424;
         trf->modulator_sys_clk_ctrl =
             (trf->modulator_sys_clk_ctrl & 0xf8) |
             TRF7970A_MODULATOR_DEPTH_ASK10;
         trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
         break;
     case NFC_DIGITAL_RF_TECH_ISO15693:
         trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
         trf->modulator_sys_clk_ctrl =
             (trf->modulator_sys_clk_ctrl & 0xf8) |
             TRF7970A_MODULATOR_DEPTH_OOK;
         trf->guard_time = TRF7970A_GUARD_TIME_15693;
         break;
     default:
         dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
         return -EINVAL;
     }
 
     trf->technology = tech;
 
     /* If in initiator mode and not changing the RF tech due to a
      * PSL sequence (indicated by 'trf->iso_ctrl == 0xff' from
      * trf7970a_init()), clear the NFC Target Detection Level register
      * due to erratum.
      */
     if (trf->iso_ctrl == 0xff)
         ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
 
     return ret;
 }
 
 static int trf7970a_is_rf_field(struct trf7970a *trf, bool *is_rf_field)
 {
     int ret;
     u8 rssi;
 
     ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
                  trf->chip_status_ctrl |
                  TRF7970A_CHIP_STATUS_REC_ON);
     if (ret)
         return ret;
 
     ret = trf7970a_cmd(trf, TRF7970A_CMD_TEST_EXT_RF);
     if (ret)
         return ret;
 
     usleep_range(50, 60);
 
     ret = trf7970a_read(trf, TRF7970A_RSSI_OSC_STATUS, &rssi);
     if (ret)
         return ret;
 
     ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
                  trf->chip_status_ctrl);
     if (ret)
         return ret;
 
     if (rssi & TRF7970A_RSSI_OSC_STATUS_RSSI_MASK)
         *is_rf_field = true;
     else
         *is_rf_field = false;
 
     return 0;
 }
 
 static int trf7970a_in_config_framing(struct trf7970a *trf, int framing)
 {
     u8 iso_ctrl = trf->iso_ctrl_tech;
     bool is_rf_field = false;
     int ret;
 
     dev_dbg(trf->dev, "framing: %d\n", framing);
 
     switch (framing) {
     case NFC_DIGITAL_FRAMING_NFCA_SHORT:
     case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
         trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
         iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
         break;
     case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
     case NFC_DIGITAL_FRAMING_NFCA_T4T:
     case NFC_DIGITAL_FRAMING_NFCB:
     case NFC_DIGITAL_FRAMING_NFCB_T4T:
     case NFC_DIGITAL_FRAMING_NFCF:
     case NFC_DIGITAL_FRAMING_NFCF_T3T:
     case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY:
     case NFC_DIGITAL_FRAMING_ISO15693_T5T:
     case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
     case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
         trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
         iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
         break;
     case NFC_DIGITAL_FRAMING_NFCA_T2T:
         trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
         iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
         break;
     default:
         dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
         return -EINVAL;
     }
 
     trf->framing = framing;
 
     if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
         ret = trf7970a_is_rf_field(trf, &is_rf_field);
         if (ret)
             return ret;
 
         if (is_rf_field)
             return -EBUSY;
     }
 
     if (iso_ctrl != trf->iso_ctrl) {
         ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
         if (ret)
             return ret;
 
         trf->iso_ctrl = iso_ctrl;
 
         ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
                      trf->modulator_sys_clk_ctrl);
         if (ret)
             return ret;
     }
 
     if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
         ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
                      trf->chip_status_ctrl |
                      TRF7970A_CHIP_STATUS_RF_ON);
         if (ret)
             return ret;
 
         trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
 
         usleep_range(trf->guard_time, trf->guard_time + 1000);
     }
 
     return 0;
 }
 
 static int trf7970a_in_configure_hw(struct nfc_digital_dev *ddev, int type,
                     int param)
 {
     struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
     int ret;
 
     dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
 
     mutex_lock(&trf->lock);
 
     trf->is_initiator = true;
 
     if ((trf->state == TRF7970A_ST_PWR_OFF) ||
         (trf->state == TRF7970A_ST_RF_OFF)) {
         ret = trf7970a_switch_rf_on(trf);
         if (ret)
             goto err_unlock;
     }
 
     switch (type) {
     case NFC_DIGITAL_CONFIG_RF_TECH:
         ret = trf7970a_in_config_rf_tech(trf, param);
         break;
     case NFC_DIGITAL_CONFIG_FRAMING:
         ret = trf7970a_in_config_framing(trf, param);
         break;
     default:
         dev_dbg(trf->dev, "Unknown type: %d\n", type);
         ret = -EINVAL;
     }
 
 err_unlock:
     mutex_unlock(&trf->lock);
     return ret;
 }
 
 static int trf7970a_is_iso15693_write_or_lock(u8 cmd)
 {
     switch (cmd) {
     case ISO15693_CMD_WRITE_SINGLE_BLOCK:
     case ISO15693_CMD_LOCK_BLOCK:
     case ISO15693_CMD_WRITE_MULTIPLE_BLOCK:
     case ISO15693_CMD_WRITE_AFI:
     case ISO15693_CMD_LOCK_AFI:
     case ISO15693_CMD_WRITE_DSFID:
     case ISO15693_CMD_LOCK_DSFID:
         return 1;
     default:
         return 0;
     }
 }
 
 static int trf7970a_per_cmd_config(struct trf7970a *trf,
                    const struct sk_buff *skb)
 {
     const u8 *req = skb->data;
     u8 special_fcn_reg1, iso_ctrl;
     int ret;
 
     trf->issue_eof = false;
 
     /* When issuing Type 2 read command, make sure the '4_bit_RX' bit in
      * special functions register 1 is cleared; otherwise, its a write or
      * sector select command and '4_bit_RX' must be set.
      *
      * When issuing an ISO 15693 command, inspect the flags byte to see
      * what speed to use.  Also, remember if the OPTION flag is set on
      * a Type 5 write or lock command so the driver will know that it
      * has to send an EOF in order to get a response.
      */
     if ((trf->technology == NFC_DIGITAL_RF_TECH_106A) &&
         (trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T)) {
         if (req[0] == NFC_T2T_CMD_READ)
             special_fcn_reg1 = 0;
         else
             special_fcn_reg1 = TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX;
 
         if (special_fcn_reg1 != trf->special_fcn_reg1) {
             ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1,
                          special_fcn_reg1);
             if (ret)
                 return ret;
 
             trf->special_fcn_reg1 = special_fcn_reg1;
         }
     } else if (trf->technology == NFC_DIGITAL_RF_TECH_ISO15693) {
         iso_ctrl = trf->iso_ctrl & ~TRF7970A_ISO_CTRL_RFID_SPEED_MASK;
 
         switch (req[0] & ISO15693_REQ_FLAG_SPEED_MASK) {
         case 0x00:
             iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_662;
             break;
         case ISO15693_REQ_FLAG_SUB_CARRIER:
             iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a;
             break;
         case ISO15693_REQ_FLAG_DATA_RATE:
             iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
             break;
         case (ISO15693_REQ_FLAG_SUB_CARRIER |
               ISO15693_REQ_FLAG_DATA_RATE):
             iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669;
             break;
         }
 
         if (iso_ctrl != trf->iso_ctrl) {
             ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
             if (ret)
                 return ret;
 
             trf->iso_ctrl = iso_ctrl;
         }
 
         if ((trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) &&
             trf7970a_is_iso15693_write_or_lock(req[1]) &&
             (req[0] & ISO15693_REQ_FLAG_OPTION))
             trf->issue_eof = true;
     }
 
     return 0;
 }
 
 static int trf7970a_send_cmd(struct nfc_digital_dev *ddev,
                  struct sk_buff *skb, u16 timeout,
                  nfc_digital_cmd_complete_t cb, void *arg)
 {
     struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
     u8 prefix[5];
     unsigned int len;
     int ret;
     u8 status;
 
     dev_dbg(trf->dev, "New request - state: %d, timeout: %d ms, len: %d\n",
         trf->state, timeout, skb->len);
 
     if (skb->len > TRF7970A_TX_MAX)
         return -EINVAL;
 
     mutex_lock(&trf->lock);
 
     if ((trf->state != TRF7970A_ST_IDLE) &&
         (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
         dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
             trf->state);
         ret = -EIO;
         goto out_err;
     }
 
     if (trf->aborting) {
         dev_dbg(trf->dev, "Abort process complete\n");
         trf->aborting = false;
         ret = -ECANCELED;
         goto out_err;
     }
 
     if (timeout) {
         trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
                          GFP_KERNEL);
         if (!trf->rx_skb) {
             dev_dbg(trf->dev, "Can't alloc rx_skb\n");
             ret = -ENOMEM;
             goto out_err;
         }
     }
 
     if (trf->state == TRF7970A_ST_IDLE_RX_BLOCKED) {
         ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
         if (ret)
             goto out_err;
 
         trf->state = TRF7970A_ST_IDLE;
     }
 
     if (trf->is_initiator) {
         ret = trf7970a_per_cmd_config(trf, skb);
         if (ret)
             goto out_err;
     }
 
     trf->ddev = ddev;
     trf->tx_skb = skb;
     trf->cb = cb;
     trf->cb_arg = arg;
     trf->timeout = timeout;
     trf->ignore_timeout = false;
 
     len = skb->len;
 
     /* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
      * on what the current framing is, the address of the TX length byte 1
      * register (0x1d), and the 2 byte length of the data to be transmitted.
      * That totals 5 bytes.
      */
     prefix[0] = TRF7970A_CMD_BIT_CTRL |
         TRF7970A_CMD_BIT_OPCODE(TRF7970A_CMD_FIFO_RESET);
     prefix[1] = TRF7970A_CMD_BIT_CTRL |
         TRF7970A_CMD_BIT_OPCODE(trf->tx_cmd);
     prefix[2] = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_TX_LENGTH_BYTE1;
 
     if (trf->framing == NFC_DIGITAL_FRAMING_NFCA_SHORT) {
         prefix[3] = 0x00;
         prefix[4] = 0x0f;   /* 7 bits */
     } else {
         prefix[3] = (len & 0xf00) >> 4;
         prefix[3] |= ((len & 0xf0) >> 4);
         prefix[4] = ((len & 0x0f) << 4);
     }
 
     len = min_t(int, skb->len, TRF7970A_FIFO_SIZE);
 
     /* Clear possible spurious interrupt */
     ret = trf7970a_read_irqstatus(trf, &status);
     if (ret)
         goto out_err;
 
     ret = trf7970a_transmit(trf, skb, len, prefix, sizeof(prefix));
     if (ret) {
         kfree_skb(trf->rx_skb);
         trf->rx_skb = NULL;
     }
 
 out_err:
     mutex_unlock(&trf->lock);
     return ret;
 }
 
 static int trf7970a_tg_config_rf_tech(struct trf7970a *trf, int tech)
 {
     int ret = 0;
 
     dev_dbg(trf->dev, "rf technology: %d\n", tech);
 
     switch (tech) {
     case NFC_DIGITAL_RF_TECH_106A:
         trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
             TRF7970A_ISO_CTRL_NFC_CE | TRF7970A_ISO_CTRL_NFC_CE_14443A;
         trf->modulator_sys_clk_ctrl =
             (trf->modulator_sys_clk_ctrl & 0xf8) |
             TRF7970A_MODULATOR_DEPTH_OOK;
         break;
     case NFC_DIGITAL_RF_TECH_212F:
         trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
             TRF7970A_ISO_CTRL_NFC_NFCF_212;
         trf->modulator_sys_clk_ctrl =
             (trf->modulator_sys_clk_ctrl & 0xf8) |
             TRF7970A_MODULATOR_DEPTH_ASK10;
         break;
     case NFC_DIGITAL_RF_TECH_424F:
         trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
             TRF7970A_ISO_CTRL_NFC_NFCF_424;
         trf->modulator_sys_clk_ctrl =
             (trf->modulator_sys_clk_ctrl & 0xf8) |
             TRF7970A_MODULATOR_DEPTH_ASK10;
         break;
     default:
         dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
         return -EINVAL;
     }
 
     trf->technology = tech;
 
     /* Normally we write the ISO_CTRL register in
      * trf7970a_tg_config_framing() because the framing can change
      * the value written.  However, when sending a PSL RES,
      * digital_tg_send_psl_res_complete() doesn't call
      * trf7970a_tg_config_framing() so we must write the register
      * here.
      */
     if ((trf->framing == NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED) &&
         (trf->iso_ctrl_tech != trf->iso_ctrl)) {
         ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
                      trf->iso_ctrl_tech);
 
         trf->iso_ctrl = trf->iso_ctrl_tech;
     }
 
     return ret;
 }
 
 /* Since this is a target routine, several of the framing calls are
  * made between receiving the request and sending the response so they
  * should take effect until after the response is sent.  This is accomplished
  * by skipping the ISO_CTRL register write here and doing it in the interrupt
  * handler.
  */
 static int trf7970a_tg_config_framing(struct trf7970a *trf, int framing)
 {
     u8 iso_ctrl = trf->iso_ctrl_tech;
     int ret;
 
     dev_dbg(trf->dev, "framing: %d\n", framing);
 
     switch (framing) {
     case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
         trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
         iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
         break;
     case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
     case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
     case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
         /* These ones are applied in the interrupt handler */
         iso_ctrl = trf->iso_ctrl; /* Don't write to ISO_CTRL yet */
         break;
     case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
         trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
         iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
         break;
     case NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED:
         trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
         iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
         break;
     default:
         dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
         return -EINVAL;
     }
 
     trf->framing = framing;
 
     if (iso_ctrl != trf->iso_ctrl) {
         ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
         if (ret)
             return ret;
 
         trf->iso_ctrl = iso_ctrl;
 
         ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
                      trf->modulator_sys_clk_ctrl);
         if (ret)
             return ret;
     }
 
     if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
         ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
                      trf->chip_status_ctrl |
                      TRF7970A_CHIP_STATUS_RF_ON);
         if (ret)
             return ret;
 
         trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
     }
 
     return 0;
 }
 
 static int trf7970a_tg_configure_hw(struct nfc_digital_dev *ddev, int type,
                     int param)
 {
     struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
     int ret;
 
     dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
 
     mutex_lock(&trf->lock);
 
     trf->is_initiator = false;
 
     if ((trf->state == TRF7970A_ST_PWR_OFF) ||
         (trf->state == TRF7970A_ST_RF_OFF)) {
         ret = trf7970a_switch_rf_on(trf);
         if (ret)
             goto err_unlock;
     }
 
     switch (type) {
     case NFC_DIGITAL_CONFIG_RF_TECH:
         ret = trf7970a_tg_config_rf_tech(trf, param);
         break;
     case NFC_DIGITAL_CONFIG_FRAMING:
         ret = trf7970a_tg_config_framing(trf, param);
         break;
     default:
         dev_dbg(trf->dev, "Unknown type: %d\n", type);
         ret = -EINVAL;
     }
 
 err_unlock:
     mutex_unlock(&trf->lock);
     return ret;
 }
 
 static int _trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
                    nfc_digital_cmd_complete_t cb, void *arg,
                    bool mode_detect)
 {
     struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
     int ret;
 
     mutex_lock(&trf->lock);
 
     if ((trf->state != TRF7970A_ST_IDLE) &&
         (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
         dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
             trf->state);
         ret = -EIO;
         goto out_err;
     }
 
     if (trf->aborting) {
         dev_dbg(trf->dev, "Abort process complete\n");
         trf->aborting = false;
         ret = -ECANCELED;
         goto out_err;
     }
 
     trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
                      GFP_KERNEL);
     if (!trf->rx_skb) {
         dev_dbg(trf->dev, "Can't alloc rx_skb\n");
         ret = -ENOMEM;
         goto out_err;
     }
 
     ret = trf7970a_write(trf, TRF7970A_RX_SPECIAL_SETTINGS,
                  TRF7970A_RX_SPECIAL_SETTINGS_HBT |
                  TRF7970A_RX_SPECIAL_SETTINGS_M848 |
                  TRF7970A_RX_SPECIAL_SETTINGS_C424 |
                  TRF7970A_RX_SPECIAL_SETTINGS_C212);
     if (ret)
         goto out_err;
 
     ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
                  trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
     if (ret)
         goto out_err;
 
     ret = trf7970a_write(trf, TRF7970A_NFC_LOW_FIELD_LEVEL,
                  TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(0x3));
     if (ret)
         goto out_err;
 
     ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL,
                  TRF7970A_NFC_TARGET_LEVEL_RFDET(0x7));
     if (ret)
         goto out_err;
 
     trf->ddev = ddev;
     trf->cb = cb;
     trf->cb_arg = arg;
     trf->timeout = timeout;
     trf->ignore_timeout = false;
 
     ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
     if (ret)
         goto out_err;
 
     trf->state = mode_detect ? TRF7970A_ST_LISTENING_MD :
                    TRF7970A_ST_LISTENING;
 
     schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
 
 out_err:
     mutex_unlock(&trf->lock);
     return ret;
 }
 
 static int trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
                   nfc_digital_cmd_complete_t cb, void *arg)
 {
     const struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
 
     dev_dbg(trf->dev, "Listen - state: %d, timeout: %d ms\n",
         trf->state, timeout);
 
     return _trf7970a_tg_listen(ddev, timeout, cb, arg, false);
 }
 
 static int trf7970a_tg_listen_md(struct nfc_digital_dev *ddev,
                  u16 timeout, nfc_digital_cmd_complete_t cb,
                  void *arg)
 {
     const struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
     int ret;
 
     dev_dbg(trf->dev, "Listen MD - state: %d, timeout: %d ms\n",
         trf->state, timeout);
 
     ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
                        NFC_DIGITAL_RF_TECH_106A);
     if (ret)
         return ret;
 
     ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
                        NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
     if (ret)
         return ret;
 
     return _trf7970a_tg_listen(ddev, timeout, cb, arg, true);
 }
 
 static int trf7970a_tg_get_rf_tech(struct nfc_digital_dev *ddev, u8 *rf_tech)
 {
     const struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
 
     dev_dbg(trf->dev, "Get RF Tech - state: %d, rf_tech: %d\n",
         trf->state, trf->md_rf_tech);
 
     *rf_tech = trf->md_rf_tech;
 
     return 0;
 }
 
 static void trf7970a_abort_cmd(struct nfc_digital_dev *ddev)
 {
     struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
 
     dev_dbg(trf->dev, "Abort process initiated\n");
 
     mutex_lock(&trf->lock);
 
     switch (trf->state) {
     case TRF7970A_ST_WAIT_FOR_TX_FIFO:
     case TRF7970A_ST_WAIT_FOR_RX_DATA:
     case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
     case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
         trf->aborting = true;
         break;
     case TRF7970A_ST_LISTENING:
         trf->ignore_timeout = !cancel_delayed_work(&trf->timeout_work);
         trf7970a_send_err_upstream(trf, -ECANCELED);
         dev_dbg(trf->dev, "Abort process complete\n");
         break;
     default:
         break;
     }
 
     mutex_unlock(&trf->lock);
 }
 
 static const struct nfc_digital_ops trf7970a_nfc_ops = {
     .in_configure_hw    = trf7970a_in_configure_hw,
     .in_send_cmd        = trf7970a_send_cmd,
     .tg_configure_hw    = trf7970a_tg_configure_hw,
     .tg_send_cmd        = trf7970a_send_cmd,
     .tg_listen      = trf7970a_tg_listen,
     .tg_listen_md       = trf7970a_tg_listen_md,
     .tg_get_rf_tech     = trf7970a_tg_get_rf_tech,
     .switch_rf      = trf7970a_switch_rf,
     .abort_cmd      = trf7970a_abort_cmd,
 };
 
 static int trf7970a_power_up(struct trf7970a *trf)
 {
     int ret;
 
     dev_dbg(trf->dev, "Powering up - state: %d\n", trf->state);
 
     if (trf->state != TRF7970A_ST_PWR_OFF)
         return 0;
 
     ret = regulator_enable(trf->regulator);
     if (ret) {
         dev_err(trf->dev, "%s - Can't enable VIN: %d\n", __func__, ret);
         return ret;
     }
 
     usleep_range(5000, 6000);
 
     if (trf->en2_gpiod &&
         !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW)) {
         gpiod_set_value_cansleep(trf->en2_gpiod, 1);
         usleep_range(1000, 2000);
     }
 
     gpiod_set_value_cansleep(trf->en_gpiod, 1);
 
     usleep_range(20000, 21000);
 
     trf->state = TRF7970A_ST_RF_OFF;
 
     return 0;
 }
 
 static int trf7970a_power_down(struct trf7970a *trf)
 {
     int ret;
 
     dev_dbg(trf->dev, "Powering down - state: %d\n", trf->state);
 
     if (trf->state == TRF7970A_ST_PWR_OFF)
         return 0;
 
     if (trf->state != TRF7970A_ST_RF_OFF) {
         dev_dbg(trf->dev, "Can't power down - not RF_OFF state (%d)\n",
             trf->state);
         return -EBUSY;
     }
 
     gpiod_set_value_cansleep(trf->en_gpiod, 0);
 
     if (trf->en2_gpiod && !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW))
         gpiod_set_value_cansleep(trf->en2_gpiod, 0);
 
     ret = regulator_disable(trf->regulator);
     if (ret)
         dev_err(trf->dev, "%s - Can't disable VIN: %d\n", __func__,
             ret);
 
     trf->state = TRF7970A_ST_PWR_OFF;
 
     return ret;
 }
 
 static int trf7970a_startup(struct trf7970a *trf)
 {
     int ret;
 
     ret = trf7970a_power_up(trf);
     if (ret)
         return ret;
 
     pm_runtime_set_active(trf->dev);
     pm_runtime_enable(trf->dev);
     pm_runtime_mark_last_busy(trf->dev);
 
     return 0;
 }
 
 static void trf7970a_shutdown(struct trf7970a *trf)
 {
     switch (trf->state) {
     case TRF7970A_ST_WAIT_FOR_TX_FIFO:
     case TRF7970A_ST_WAIT_FOR_RX_DATA:
     case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
     case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
     case TRF7970A_ST_LISTENING:
         trf7970a_send_err_upstream(trf, -ECANCELED);
         fallthrough;
     case TRF7970A_ST_IDLE:
     case TRF7970A_ST_IDLE_RX_BLOCKED:
         trf7970a_switch_rf_off(trf);
         break;
     default:
         break;
     }
 
     pm_runtime_disable(trf->dev);
     pm_runtime_set_suspended(trf->dev);
 
     trf7970a_power_down(trf);
 }
 
 static int trf7970a_get_autosuspend_delay(const struct device_node *np)
 {
     int autosuspend_delay, ret;
 
     ret = of_property_read_u32(np, "autosuspend-delay", &autosuspend_delay);
     if (ret)
         autosuspend_delay = TRF7970A_AUTOSUSPEND_DELAY;
 
     return autosuspend_delay;
 }
 
 static int trf7970a_probe(struct spi_device *spi)
 {
     const struct device_node *np = spi->dev.of_node;
     struct trf7970a *trf;
     int uvolts, autosuspend_delay, ret;
     u32 clk_freq = TRF7970A_13MHZ_CLOCK_FREQUENCY;
 
     if (!np) {
         dev_err(&spi->dev, "No Device Tree entry\n");
         return -EINVAL;
     }
 
     trf = devm_kzalloc(&spi->dev, sizeof(*trf), GFP_KERNEL);
     if (!trf)
         return -ENOMEM;
 
     trf->state = TRF7970A_ST_PWR_OFF;
     trf->dev = &spi->dev;
     trf->spi = spi;
 
     spi->mode = SPI_MODE_1;
     spi->bits_per_word = 8;
 
     ret = spi_setup(spi);
     if (ret < 0) {
         dev_err(trf->dev, "Can't set up SPI Communication\n");
         return ret;
     }
 
     if (of_property_read_bool(np, "irq-status-read-quirk"))
         trf->quirks |= TRF7970A_QUIRK_IRQ_STATUS_READ;
 
     /* There are two enable pins - only EN must be present in the DT */
     trf->en_gpiod = devm_gpiod_get_index(trf->dev, "ti,enable", 0,
                          GPIOD_OUT_LOW);
     if (IS_ERR(trf->en_gpiod)) {
         dev_err(trf->dev, "No EN GPIO property\n");
         return PTR_ERR(trf->en_gpiod);
     }
 
     trf->en2_gpiod = devm_gpiod_get_index_optional(trf->dev, "ti,enable", 1,
                                GPIOD_OUT_LOW);
     if (!trf->en2_gpiod) {
         dev_info(trf->dev, "No EN2 GPIO property\n");
     } else if (IS_ERR(trf->en2_gpiod)) {
         dev_err(trf->dev, "Error getting EN2 GPIO property: %ld\n",
             PTR_ERR(trf->en2_gpiod));
         return PTR_ERR(trf->en2_gpiod);
     } else if (of_property_read_bool(np, "en2-rf-quirk")) {
         trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;
     }
 
     of_property_read_u32(np, "clock-frequency", &clk_freq);
     if ((clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY) &&
         (clk_freq != TRF7970A_13MHZ_CLOCK_FREQUENCY)) {
         dev_err(trf->dev,
             "clock-frequency (%u Hz) unsupported\n", clk_freq);
         return -EINVAL;
     }
 
     if (clk_freq == TRF7970A_27MHZ_CLOCK_FREQUENCY) {
         trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_27MHZ;
         dev_dbg(trf->dev, "trf7970a configured for 27MHz crystal\n");
     } else {
         trf->modulator_sys_clk_ctrl = 0;
     }
 
     ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL,
                     trf7970a_irq,
                     IRQF_TRIGGER_RISING | IRQF_ONESHOT,
                     "trf7970a", trf);
     if (ret) {
         dev_err(trf->dev, "Can't request IRQ#%d: %d\n", spi->irq, ret);
         return ret;
     }
 
     mutex_init(&trf->lock);
     INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
 
     trf->regulator = devm_regulator_get(&spi->dev, "vin");
     if (IS_ERR(trf->regulator)) {
         ret = PTR_ERR(trf->regulator);
         dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret);
         goto err_destroy_lock;
     }
 
     ret = regulator_enable(trf->regulator);
     if (ret) {
         dev_err(trf->dev, "Can't enable VIN: %d\n", ret);
         goto err_destroy_lock;
     }
 
     uvolts = regulator_get_voltage(trf->regulator);
     if (uvolts > 4000000)
         trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;
 
     trf->regulator = devm_regulator_get(&spi->dev, "vdd-io");
     if (IS_ERR(trf->regulator)) {
         ret = PTR_ERR(trf->regulator);
         dev_err(trf->dev, "Can't get VDD_IO regulator: %d\n", ret);
         goto err_destroy_lock;
     }
 
     ret = regulator_enable(trf->regulator);
     if (ret) {
         dev_err(trf->dev, "Can't enable VDD_IO: %d\n", ret);
         goto err_destroy_lock;
     }
 
     if (regulator_get_voltage(trf->regulator) == 1800000) {
         trf->io_ctrl = TRF7970A_REG_IO_CTRL_IO_LOW;
         dev_dbg(trf->dev, "trf7970a config vdd_io to 1.8V\n");
     }
 
     trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,
                         TRF7970A_SUPPORTED_PROTOCOLS,
                         NFC_DIGITAL_DRV_CAPS_IN_CRC |
                         NFC_DIGITAL_DRV_CAPS_TG_CRC, 0,
                         0);
     if (!trf->ddev) {
         dev_err(trf->dev, "Can't allocate NFC digital device\n");
         ret = -ENOMEM;
         goto err_disable_regulator;
     }
 
     nfc_digital_set_parent_dev(trf->ddev, trf->dev);
     nfc_digital_set_drvdata(trf->ddev, trf);
     spi_set_drvdata(spi, trf);
 
     autosuspend_delay = trf7970a_get_autosuspend_delay(np);
 
     pm_runtime_set_autosuspend_delay(trf->dev, autosuspend_delay);
     pm_runtime_use_autosuspend(trf->dev);
 
     ret = trf7970a_startup(trf);
     if (ret)
         goto err_free_ddev;
 
     ret = nfc_digital_register_device(trf->ddev);
     if (ret) {
         dev_err(trf->dev, "Can't register NFC digital device: %d\n",
             ret);
         goto err_shutdown;
     }
 
     return 0;
 
 err_shutdown:
     trf7970a_shutdown(trf);
 err_free_ddev:
     nfc_digital_free_device(trf->ddev);
 err_disable_regulator:
     regulator_disable(trf->regulator);
 err_destroy_lock:
     mutex_destroy(&trf->lock);
     return ret;
 }
 
 static void trf7970a_remove(struct spi_device *spi)
 {
     struct trf7970a *trf = spi_get_drvdata(spi);
 
     mutex_lock(&trf->lock);
 
     trf7970a_shutdown(trf);
 
     mutex_unlock(&trf->lock);
 
     nfc_digital_unregister_device(trf->ddev);
     nfc_digital_free_device(trf->ddev);
 
     regulator_disable(trf->regulator);
 
     mutex_destroy(&trf->lock);
 }
 
 #ifdef CONFIG_PM_SLEEP
 static int trf7970a_suspend(struct device *dev)
 {
     struct spi_device *spi = to_spi_device(dev);
     struct trf7970a *trf = spi_get_drvdata(spi);
 
     mutex_lock(&trf->lock);
 
     trf7970a_shutdown(trf);
 
     mutex_unlock(&trf->lock);
 
     return 0;
 }
 
 static int trf7970a_resume(struct device *dev)
 {
     struct spi_device *spi = to_spi_device(dev);
     struct trf7970a *trf = spi_get_drvdata(spi);
     int ret;
 
     mutex_lock(&trf->lock);
 
     ret = trf7970a_startup(trf);
 
     mutex_unlock(&trf->lock);
 
     return ret;
 }
 #endif
 
 #ifdef CONFIG_PM
 static int trf7970a_pm_runtime_suspend(struct device *dev)
 {
     struct spi_device *spi = to_spi_device(dev);
     struct trf7970a *trf = spi_get_drvdata(spi);
     int ret;
 
     mutex_lock(&trf->lock);
 
     ret = trf7970a_power_down(trf);
 
     mutex_unlock(&trf->lock);
 
     return ret;
 }
 
 static int trf7970a_pm_runtime_resume(struct device *dev)
 {
     struct spi_device *spi = to_spi_device(dev);
     struct trf7970a *trf = spi_get_drvdata(spi);
     int ret;
 
     ret = trf7970a_power_up(trf);
     if (!ret)
         pm_runtime_mark_last_busy(dev);
 
     return ret;
 }
 #endif
 
 static const struct dev_pm_ops trf7970a_pm_ops = {
     SET_SYSTEM_SLEEP_PM_OPS(trf7970a_suspend, trf7970a_resume)
     SET_RUNTIME_PM_OPS(trf7970a_pm_runtime_suspend,
                trf7970a_pm_runtime_resume, NULL)
 };
 
 static const struct of_device_id trf7970a_of_match[] = {
     {.compatible = "ti,trf7970a",},
     {},
 };
 
 MODULE_DEVICE_TABLE(of, trf7970a_of_match);
 
 static const struct spi_device_id trf7970a_id_table[] = {
     {"trf7970a", 0},
     {}
 };
 
 MODULE_DEVICE_TABLE(spi, trf7970a_id_table);
 
 static struct spi_driver trf7970a_spi_driver = {
     .probe      = trf7970a_probe,
     .remove     = trf7970a_remove,
     .id_table   = trf7970a_id_table,
     .driver = {
         .name       = "trf7970a",
         .of_match_table = of_match_ptr(trf7970a_of_match),
         .pm     = &trf7970a_pm_ops,
     },
 };
 
 module_spi_driver(trf7970a_spi_driver);
 
 MODULE_AUTHOR("Mark A. Greer <mgreer@animalcreek.com>");
 MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("TI trf7970a RFID/NFC Transceiver Driver");

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