trf7970a.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * TI TRF7970a RFID/NFC Transceiver Driver
   4 *
   5 * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
   6 *
   7 * Author: Erick Macias <emacias@ti.com>
   8 * Author: Felipe Balbi <balbi@ti.com>
   9 * Author: Mark A. Greer <mgreer@animalcreek.com>
  10 */
  11
  12#include <linux/module.h>
  13#include <linux/device.h>
  14#include <linux/netdevice.h>
  15#include <linux/interrupt.h>
  16#include <linux/pm_runtime.h>
  17#include <linux/nfc.h>
  18#include <linux/skbuff.h>
  19#include <linux/delay.h>
  20#include <linux/gpio/consumer.h>
  21#include <linux/of.h>
  22#include <linux/spi/spi.h>
  23#include <linux/regulator/consumer.h>
  24
  25#include <net/nfc/nfc.h>
  26#include <net/nfc/digital.h>
  27
  28/* There are 3 ways the host can communicate with the trf7970a:
  29 * parallel mode, SPI with Slave Select (SS) mode, and SPI without
  30 * SS mode.  The driver only supports the two SPI modes.
  31 *
  32 * The trf7970a is very timing sensitive and the VIN, EN2, and EN
  33 * pins must asserted in that order and with specific delays in between.
  34 * The delays used in the driver were provided by TI and have been
  35 * confirmed to work with this driver.  There is a bug with the current
  36 * version of the trf7970a that requires that EN2 remain low no matter
  37 * what.  If it goes high, it will generate an RF field even when in
  38 * passive target mode.  TI has indicated that the chip will work okay
  39 * when EN2 is left low.  The 'en2-rf-quirk' device tree property
  40 * indicates that trf7970a currently being used has the erratum and
  41 * that EN2 must be kept low.
  42 *
  43 * Timeouts are implemented using the delayed workqueue kernel facility.
  44 * Timeouts are required so things don't hang when there is no response
  45 * from the trf7970a (or tag).  Using this mechanism creates a race with
  46 * interrupts, however.  That is, an interrupt and a timeout could occur
  47 * closely enough together that one is blocked by the mutex while the other
  48 * executes.  When the timeout handler executes first and blocks the
  49 * interrupt handler, it will eventually set the state to IDLE so the
  50 * interrupt handler will check the state and exit with no harm done.
  51 * When the interrupt handler executes first and blocks the timeout handler,
  52 * the cancel_delayed_work() call will know that it didn't cancel the
  53 * work item (i.e., timeout) and will return zero.  That return code is
  54 * used by the timer handler to indicate that it should ignore the timeout
  55 * once its unblocked.
  56 *
  57 * Aborting an active command isn't as simple as it seems because the only
  58 * way to abort a command that's already been sent to the tag is so turn
  59 * off power to the tag.  If we do that, though, we'd have to go through
  60 * the entire anticollision procedure again but the digital layer doesn't
  61 * support that.  So, if an abort is received before trf7970a_send_cmd()
  62 * has sent the command to the tag, it simply returns -ECANCELED.  If the
  63 * command has already been sent to the tag, then the driver continues
  64 * normally and recieves the response data (or error) but just before
  65 * sending the data upstream, it frees the rx_skb and sends -ECANCELED
  66 * upstream instead.  If the command failed, that error will be sent
  67 * upstream.
  68 *
  69 * When recieving data from a tag and the interrupt status register has
  70 * only the SRX bit set, it means that all of the data has been received
  71 * (once what's in the fifo has been read).  However, depending on timing
  72 * an interrupt status with only the SRX bit set may not be recived.  In
  73 * those cases, the timeout mechanism is used to wait 20 ms in case more
  74 * data arrives.  After 20 ms, it is assumed that all of the data has been
  75 * received and the accumulated rx data is sent upstream.  The
  76 * 'TRF7970A_ST_WAIT_FOR_RX_DATA_CONT' state is used for this purpose
  77 * (i.e., it indicates that some data has been received but we're not sure
  78 * if there is more coming so a timeout in this state means all data has
  79 * been received and there isn't an error).  The delay is 20 ms since delays
  80 * of ~16 ms have been observed during testing.
  81 *
  82 * When transmitting a frame larger than the FIFO size (127 bytes), the
  83 * driver will wait 20 ms for the FIFO to drain past the low-watermark
  84 * and generate an interrupt.  The low-watermark set to 32 bytes so the
  85 * interrupt should fire after 127 - 32 = 95 bytes have been sent.  At
  86 * the lowest possible bit rate (6.62 kbps for 15693), it will take up
  87 * to ~14.35 ms so 20 ms is used for the timeout.
  88 *
  89 * Type 2 write and sector select commands respond with a 4-bit ACK or NACK.
  90 * Having only 4 bits in the FIFO won't normally generate an interrupt so
  91 * driver enables the '4_bit_RX' bit of the Special Functions register 1
  92 * to cause an interrupt in that case.  Leaving that bit for a read command
  93 * messes up the data returned so it is only enabled when the framing is
  94 * 'NFC_DIGITAL_FRAMING_NFCA_T2T' and the command is not a read command.
  95 * Unfortunately, that means that the driver has to peek into tx frames
  96 * when the framing is 'NFC_DIGITAL_FRAMING_NFCA_T2T'.  This is done by
  97 * the trf7970a_per_cmd_config() routine.
  98 *
  99 * ISO/IEC 15693 frames specify whether to use single or double sub-carrier
 100 * frequencies and whether to use low or high data rates in the flags byte
 101 * of the frame.  This means that the driver has to peek at all 15693 frames
 102 * to determine what speed to set the communication to.  In addition, write
 103 * and lock commands use the OPTION flag to indicate that an EOF must be
 104 * sent to the tag before it will send its response.  So the driver has to
 105 * examine all frames for that reason too.
 106 *
 107 * It is unclear how long to wait before sending the EOF.  According to the
 108 * Note under Table 1-1 in section 1.6 of
 109 * http://www.ti.com/lit/ug/scbu011/scbu011.pdf, that wait should be at least
 110 * 10 ms for TI Tag-it HF-I tags; however testing has shown that is not long
 111 * enough so 20 ms is used.  So the timer is set to 40 ms - 20 ms to drain
 112 * up to 127 bytes in the FIFO at the lowest bit rate plus another 20 ms to
 113 * ensure the wait is long enough before sending the EOF.  This seems to work
 114 * reliably.
 115 */
 116
 117#define TRF7970A_SUPPORTED_PROTOCOLS \
 118		(NFC_PROTO_MIFARE_MASK | NFC_PROTO_ISO14443_MASK |	\
 119		 NFC_PROTO_ISO14443_B_MASK | NFC_PROTO_FELICA_MASK | \
 120		 NFC_PROTO_ISO15693_MASK | NFC_PROTO_NFC_DEP_MASK)
 121
 122#define TRF7970A_AUTOSUSPEND_DELAY		30000	/* 30 seconds */
 123#define TRF7970A_13MHZ_CLOCK_FREQUENCY		13560000
 124#define TRF7970A_27MHZ_CLOCK_FREQUENCY		27120000
 125
 126#define TRF7970A_RX_SKB_ALLOC_SIZE		256
 127
 128#define TRF7970A_FIFO_SIZE			127
 129
 130/* TX length is 3 nibbles long ==> 4KB - 1 bytes max */
 131#define TRF7970A_TX_MAX				(4096 - 1)
 132
 133#define TRF7970A_WAIT_FOR_TX_IRQ		20
 134#define TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT	20
 135#define TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT	20
 136#define TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF	40
 137
 138/* Guard times for various RF technologies (in us) */
 139#define TRF7970A_GUARD_TIME_NFCA		5000
 140#define TRF7970A_GUARD_TIME_NFCB		5000
 141#define TRF7970A_GUARD_TIME_NFCF		20000
 142#define TRF7970A_GUARD_TIME_15693		1000
 143
 144/* Quirks */
 145/* Erratum: When reading IRQ Status register on trf7970a, we must issue a
 146 * read continuous command for IRQ Status and Collision Position registers.
 147 */
 148#define TRF7970A_QUIRK_IRQ_STATUS_READ		BIT(0)
 149#define TRF7970A_QUIRK_EN2_MUST_STAY_LOW	BIT(1)
 150
 151/* Direct commands */
 152#define TRF7970A_CMD_IDLE			0x00
 153#define TRF7970A_CMD_SOFT_INIT			0x03
 154#define TRF7970A_CMD_RF_COLLISION		0x04
 155#define TRF7970A_CMD_RF_COLLISION_RESPONSE_N	0x05
 156#define TRF7970A_CMD_RF_COLLISION_RESPONSE_0	0x06
 157#define TRF7970A_CMD_FIFO_RESET			0x0f
 158#define TRF7970A_CMD_TRANSMIT_NO_CRC		0x10
 159#define TRF7970A_CMD_TRANSMIT			0x11
 160#define TRF7970A_CMD_DELAY_TRANSMIT_NO_CRC	0x12
 161#define TRF7970A_CMD_DELAY_TRANSMIT		0x13
 162#define TRF7970A_CMD_EOF			0x14
 163#define TRF7970A_CMD_CLOSE_SLOT			0x15
 164#define TRF7970A_CMD_BLOCK_RX			0x16
 165#define TRF7970A_CMD_ENABLE_RX			0x17
 166#define TRF7970A_CMD_TEST_INT_RF		0x18
 167#define TRF7970A_CMD_TEST_EXT_RF		0x19
 168#define TRF7970A_CMD_RX_GAIN_ADJUST		0x1a
 169
 170/* Bits determining whether its a direct command or register R/W,
 171 * whether to use a continuous SPI transaction or not, and the actual
 172 * direct cmd opcode or register address.
 173 */
 174#define TRF7970A_CMD_BIT_CTRL			BIT(7)
 175#define TRF7970A_CMD_BIT_RW			BIT(6)
 176#define TRF7970A_CMD_BIT_CONTINUOUS		BIT(5)
 177#define TRF7970A_CMD_BIT_OPCODE(opcode)		((opcode) & 0x1f)
 178
 179/* Registers addresses */
 180#define TRF7970A_CHIP_STATUS_CTRL		0x00
 181#define TRF7970A_ISO_CTRL			0x01
 182#define TRF7970A_ISO14443B_TX_OPTIONS		0x02
 183#define TRF7970A_ISO14443A_HIGH_BITRATE_OPTIONS	0x03
 184#define TRF7970A_TX_TIMER_SETTING_H_BYTE	0x04
 185#define TRF7970A_TX_TIMER_SETTING_L_BYTE	0x05
 186#define TRF7970A_TX_PULSE_LENGTH_CTRL		0x06
 187#define TRF7970A_RX_NO_RESPONSE_WAIT		0x07
 188#define TRF7970A_RX_WAIT_TIME			0x08
 189#define TRF7970A_MODULATOR_SYS_CLK_CTRL		0x09
 190#define TRF7970A_RX_SPECIAL_SETTINGS		0x0a
 191#define TRF7970A_REG_IO_CTRL			0x0b
 192#define TRF7970A_IRQ_STATUS			0x0c
 193#define TRF7970A_COLLISION_IRQ_MASK		0x0d
 194#define TRF7970A_COLLISION_POSITION		0x0e
 195#define TRF7970A_RSSI_OSC_STATUS		0x0f
 196#define TRF7970A_SPECIAL_FCN_REG1		0x10
 197#define TRF7970A_SPECIAL_FCN_REG2		0x11
 198#define TRF7970A_RAM1				0x12
 199#define TRF7970A_RAM2				0x13
 200#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS	0x14
 201#define TRF7970A_NFC_LOW_FIELD_LEVEL		0x16
 202#define TRF7970A_NFCID1				0x17
 203#define TRF7970A_NFC_TARGET_LEVEL		0x18
 204#define TRF79070A_NFC_TARGET_PROTOCOL		0x19
 205#define TRF7970A_TEST_REGISTER1			0x1a
 206#define TRF7970A_TEST_REGISTER2			0x1b
 207#define TRF7970A_FIFO_STATUS			0x1c
 208#define TRF7970A_TX_LENGTH_BYTE1		0x1d
 209#define TRF7970A_TX_LENGTH_BYTE2		0x1e
 210#define TRF7970A_FIFO_IO_REGISTER		0x1f
 211
 212/* Chip Status Control Register Bits */
 213#define TRF7970A_CHIP_STATUS_VRS5_3		BIT(0)
 214#define TRF7970A_CHIP_STATUS_REC_ON		BIT(1)
 215#define TRF7970A_CHIP_STATUS_AGC_ON		BIT(2)
 216#define TRF7970A_CHIP_STATUS_PM_ON		BIT(3)
 217#define TRF7970A_CHIP_STATUS_RF_PWR		BIT(4)
 218#define TRF7970A_CHIP_STATUS_RF_ON		BIT(5)
 219#define TRF7970A_CHIP_STATUS_DIRECT		BIT(6)
 220#define TRF7970A_CHIP_STATUS_STBY		BIT(7)
 221
 222/* ISO Control Register Bits */
 223#define TRF7970A_ISO_CTRL_15693_SGL_1OF4_662	0x00
 224#define TRF7970A_ISO_CTRL_15693_SGL_1OF256_662	0x01
 225#define TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648	0x02
 226#define TRF7970A_ISO_CTRL_15693_SGL_1OF256_2648	0x03
 227#define TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a	0x04
 228#define TRF7970A_ISO_CTRL_15693_DBL_1OF256_667	0x05
 229#define TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669	0x06
 230#define TRF7970A_ISO_CTRL_15693_DBL_1OF256_2669	0x07
 231#define TRF7970A_ISO_CTRL_14443A_106		0x08
 232#define TRF7970A_ISO_CTRL_14443A_212		0x09
 233#define TRF7970A_ISO_CTRL_14443A_424		0x0a
 234#define TRF7970A_ISO_CTRL_14443A_848		0x0b
 235#define TRF7970A_ISO_CTRL_14443B_106		0x0c
 236#define TRF7970A_ISO_CTRL_14443B_212		0x0d
 237#define TRF7970A_ISO_CTRL_14443B_424		0x0e
 238#define TRF7970A_ISO_CTRL_14443B_848		0x0f
 239#define TRF7970A_ISO_CTRL_FELICA_212		0x1a
 240#define TRF7970A_ISO_CTRL_FELICA_424		0x1b
 241#define TRF7970A_ISO_CTRL_NFC_NFCA_106		0x01
 242#define TRF7970A_ISO_CTRL_NFC_NFCF_212		0x02
 243#define TRF7970A_ISO_CTRL_NFC_NFCF_424		0x03
 244#define TRF7970A_ISO_CTRL_NFC_CE_14443A		0x00
 245#define TRF7970A_ISO_CTRL_NFC_CE_14443B		0x01
 246#define TRF7970A_ISO_CTRL_NFC_CE		BIT(2)
 247#define TRF7970A_ISO_CTRL_NFC_ACTIVE		BIT(3)
 248#define TRF7970A_ISO_CTRL_NFC_INITIATOR		BIT(4)
 249#define TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE	BIT(5)
 250#define TRF7970A_ISO_CTRL_RFID			BIT(5)
 251#define TRF7970A_ISO_CTRL_DIR_MODE		BIT(6)
 252#define TRF7970A_ISO_CTRL_RX_CRC_N		BIT(7)	/* true == No CRC */
 253
 254#define TRF7970A_ISO_CTRL_RFID_SPEED_MASK	0x1f
 255
 256/* Modulator and SYS_CLK Control Register Bits */
 257#define TRF7970A_MODULATOR_DEPTH(n)		((n) & 0x7)
 258#define TRF7970A_MODULATOR_DEPTH_ASK10		(TRF7970A_MODULATOR_DEPTH(0))
 259#define TRF7970A_MODULATOR_DEPTH_OOK		(TRF7970A_MODULATOR_DEPTH(1))
 260#define TRF7970A_MODULATOR_DEPTH_ASK7		(TRF7970A_MODULATOR_DEPTH(2))
 261#define TRF7970A_MODULATOR_DEPTH_ASK8_5		(TRF7970A_MODULATOR_DEPTH(3))
 262#define TRF7970A_MODULATOR_DEPTH_ASK13		(TRF7970A_MODULATOR_DEPTH(4))
 263#define TRF7970A_MODULATOR_DEPTH_ASK16		(TRF7970A_MODULATOR_DEPTH(5))
 264#define TRF7970A_MODULATOR_DEPTH_ASK22		(TRF7970A_MODULATOR_DEPTH(6))
 265#define TRF7970A_MODULATOR_DEPTH_ASK30		(TRF7970A_MODULATOR_DEPTH(7))
 266#define TRF7970A_MODULATOR_EN_ANA		BIT(3)
 267#define TRF7970A_MODULATOR_CLK(n)		(((n) & 0x3) << 4)
 268#define TRF7970A_MODULATOR_CLK_DISABLED		(TRF7970A_MODULATOR_CLK(0))
 269#define TRF7970A_MODULATOR_CLK_3_6		(TRF7970A_MODULATOR_CLK(1))
 270#define TRF7970A_MODULATOR_CLK_6_13		(TRF7970A_MODULATOR_CLK(2))
 271#define TRF7970A_MODULATOR_CLK_13_27		(TRF7970A_MODULATOR_CLK(3))
 272#define TRF7970A_MODULATOR_EN_OOK		BIT(6)
 273#define TRF7970A_MODULATOR_27MHZ		BIT(7)
 274
 275#define TRF7970A_RX_GAIN_REDUCTION_MAX_DB	15
 276#define TRF7970A_RX_GAIN_REDUCTION_DB_PER_LSB	5
 277#define TRF7970A_RX_SPECIAL_SETTINGS_NO_LIM	BIT(0)
 278#define TRF7970A_RX_SPECIAL_SETTINGS_AGCR	BIT(1)
 279#define TRF7970A_RX_SPECIAL_SETTINGS_GD_SHIFT	2
 280#define TRF7970A_RX_SPECIAL_SETTINGS_GD_MAX	(0x3)
 281#define TRF7970A_RX_SPECIAL_SETTINGS_GD_MASK	(TRF7970A_RX_SPECIAL_SETTINGS_GD_MAX << \
 282							TRF7970A_RX_SPECIAL_SETTINGS_GD_SHIFT)
 283#define TRF7970A_RX_SPECIAL_SETTINGS_GD_0DB	(0x0 << TRF7970A_RX_SPECIAL_SETTINGS_GD_SHIFT)
 284#define TRF7970A_RX_SPECIAL_SETTINGS_GD_5DB	(0x1 << TRF7970A_RX_SPECIAL_SETTINGS_GD_SHIFT)
 285#define TRF7970A_RX_SPECIAL_SETTINGS_GD_10DB	(0x2 << TRF7970A_RX_SPECIAL_SETTINGS_GD_SHIFT)
 286#define TRF7970A_RX_SPECIAL_SETTINGS_GD_15DB	(0x3 << TRF7970A_RX_SPECIAL_SETTINGS_GD_SHIFT)
 287#define TRF7970A_RX_SPECIAL_SETTINGS_HBT	BIT(4)
 288#define TRF7970A_RX_SPECIAL_SETTINGS_M848	BIT(5)
 289#define TRF7970A_RX_SPECIAL_SETTINGS_C424	BIT(6)
 290#define TRF7970A_RX_SPECIAL_SETTINGS_C212	BIT(7)
 291
 292#define TRF7970A_REG_IO_CTRL_VRS(v)		((v) & 0x07)
 293#define TRF7970A_REG_IO_CTRL_IO_LOW		BIT(5)
 294#define TRF7970A_REG_IO_CTRL_EN_EXT_PA		BIT(6)
 295#define TRF7970A_REG_IO_CTRL_AUTO_REG		BIT(7)
 296
 297/* IRQ Status Register Bits */
 298#define TRF7970A_IRQ_STATUS_NORESP		BIT(0)	/* ISO15693 only */
 299#define TRF7970A_IRQ_STATUS_NFC_COL_ERROR	BIT(0)
 300#define TRF7970A_IRQ_STATUS_COL			BIT(1)
 301#define TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR	BIT(2)
 302#define TRF7970A_IRQ_STATUS_NFC_RF		BIT(2)
 303#define TRF7970A_IRQ_STATUS_PARITY_ERROR	BIT(3)
 304#define TRF7970A_IRQ_STATUS_NFC_SDD		BIT(3)
 305#define TRF7970A_IRQ_STATUS_CRC_ERROR		BIT(4)
 306#define TRF7970A_IRQ_STATUS_NFC_PROTO_ERROR	BIT(4)
 307#define TRF7970A_IRQ_STATUS_FIFO		BIT(5)
 308#define TRF7970A_IRQ_STATUS_SRX			BIT(6)
 309#define TRF7970A_IRQ_STATUS_TX			BIT(7)
 310
 311#define TRF7970A_IRQ_STATUS_ERROR				\
 312		(TRF7970A_IRQ_STATUS_COL |			\
 313		 TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR |	\
 314		 TRF7970A_IRQ_STATUS_PARITY_ERROR |		\
 315		 TRF7970A_IRQ_STATUS_CRC_ERROR)
 316
 317#define TRF7970A_RSSI_OSC_STATUS_RSSI_MASK	(BIT(2) | BIT(1) | BIT(0))
 318#define TRF7970A_RSSI_OSC_STATUS_RSSI_X_MASK	(BIT(5) | BIT(4) | BIT(3))
 319#define TRF7970A_RSSI_OSC_STATUS_RSSI_OSC_OK	BIT(6)
 320
 321#define TRF7970A_SPECIAL_FCN_REG1_COL_7_6		BIT(0)
 322#define TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL		BIT(1)
 323#define TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX		BIT(2)
 324#define TRF7970A_SPECIAL_FCN_REG1_SP_DIR_MODE		BIT(3)
 325#define TRF7970A_SPECIAL_FCN_REG1_NEXT_SLOT_37US	BIT(4)
 326#define TRF7970A_SPECIAL_FCN_REG1_PAR43			BIT(5)
 327
 328#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_124	(0x0 << 2)
 329#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_120	(0x1 << 2)
 330#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_112	(0x2 << 2)
 331#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96	(0x3 << 2)
 332#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_4	0x0
 333#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_8	0x1
 334#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_16	0x2
 335#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32	0x3
 336
 337#define TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(v)	((v) & 0x07)
 338#define TRF7970A_NFC_LOW_FIELD_LEVEL_CLEX_DIS	BIT(7)
 339
 340#define TRF7970A_NFC_TARGET_LEVEL_RFDET(v)	((v) & 0x07)
 341#define TRF7970A_NFC_TARGET_LEVEL_HI_RF		BIT(3)
 342#define TRF7970A_NFC_TARGET_LEVEL_SDD_EN	BIT(5)
 343#define TRF7970A_NFC_TARGET_LEVEL_LD_S_4BYTES	(0x0 << 6)
 344#define TRF7970A_NFC_TARGET_LEVEL_LD_S_7BYTES	(0x1 << 6)
 345#define TRF7970A_NFC_TARGET_LEVEL_LD_S_10BYTES	(0x2 << 6)
 346
 347#define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106		BIT(0)
 348#define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212		BIT(1)
 349#define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424		(BIT(0) | BIT(1))
 350#define TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B	BIT(2)
 351#define TRF79070A_NFC_TARGET_PROTOCOL_PAS_106		BIT(3)
 352#define TRF79070A_NFC_TARGET_PROTOCOL_FELICA		BIT(4)
 353#define TRF79070A_NFC_TARGET_PROTOCOL_RF_L		BIT(6)
 354#define TRF79070A_NFC_TARGET_PROTOCOL_RF_H		BIT(7)
 355
 356#define TRF79070A_NFC_TARGET_PROTOCOL_106A		\
 357	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
 358	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
 359	  TRF79070A_NFC_TARGET_PROTOCOL_PAS_106 |	\
 360	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
 361
 362#define TRF79070A_NFC_TARGET_PROTOCOL_106B		\
 363	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
 364	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
 365	  TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B |	\
 366	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
 367
 368#define TRF79070A_NFC_TARGET_PROTOCOL_212F		\
 369	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
 370	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
 371	  TRF79070A_NFC_TARGET_PROTOCOL_FELICA |	\
 372	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212)
 373
 374#define TRF79070A_NFC_TARGET_PROTOCOL_424F		\
 375	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
 376	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
 377	  TRF79070A_NFC_TARGET_PROTOCOL_FELICA |	\
 378	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424)
 379
 380#define TRF7970A_FIFO_STATUS_OVERFLOW		BIT(7)
 381
 382/* NFC (ISO/IEC 14443A) Type 2 Tag commands */
 383#define NFC_T2T_CMD_READ			0x30
 384
 385/* ISO 15693 commands codes */
 386#define ISO15693_CMD_INVENTORY			0x01
 387#define ISO15693_CMD_READ_SINGLE_BLOCK		0x20
 388#define ISO15693_CMD_WRITE_SINGLE_BLOCK		0x21
 389#define ISO15693_CMD_LOCK_BLOCK			0x22
 390#define ISO15693_CMD_READ_MULTIPLE_BLOCK	0x23
 391#define ISO15693_CMD_WRITE_MULTIPLE_BLOCK	0x24
 392#define ISO15693_CMD_SELECT			0x25
 393#define ISO15693_CMD_RESET_TO_READY		0x26
 394#define ISO15693_CMD_WRITE_AFI			0x27
 395#define ISO15693_CMD_LOCK_AFI			0x28
 396#define ISO15693_CMD_WRITE_DSFID		0x29
 397#define ISO15693_CMD_LOCK_DSFID			0x2a
 398#define ISO15693_CMD_GET_SYSTEM_INFO		0x2b
 399#define ISO15693_CMD_GET_MULTIPLE_BLOCK_SECURITY_STATUS	0x2c
 400
 401/* ISO 15693 request and response flags */
 402#define ISO15693_REQ_FLAG_SUB_CARRIER		BIT(0)
 403#define ISO15693_REQ_FLAG_DATA_RATE		BIT(1)
 404#define ISO15693_REQ_FLAG_INVENTORY		BIT(2)
 405#define ISO15693_REQ_FLAG_PROTOCOL_EXT		BIT(3)
 406#define ISO15693_REQ_FLAG_SELECT		BIT(4)
 407#define ISO15693_REQ_FLAG_AFI			BIT(4)
 408#define ISO15693_REQ_FLAG_ADDRESS		BIT(5)
 409#define ISO15693_REQ_FLAG_NB_SLOTS		BIT(5)
 410#define ISO15693_REQ_FLAG_OPTION		BIT(6)
 411
 412#define ISO15693_REQ_FLAG_SPEED_MASK \
 413		(ISO15693_REQ_FLAG_SUB_CARRIER | ISO15693_REQ_FLAG_DATA_RATE)
 414
 415enum trf7970a_state {
 416	TRF7970A_ST_PWR_OFF,
 417	TRF7970A_ST_RF_OFF,
 418	TRF7970A_ST_IDLE,
 419	TRF7970A_ST_IDLE_RX_BLOCKED,
 420	TRF7970A_ST_WAIT_FOR_TX_FIFO,
 421	TRF7970A_ST_WAIT_FOR_RX_DATA,
 422	TRF7970A_ST_WAIT_FOR_RX_DATA_CONT,
 423	TRF7970A_ST_WAIT_TO_ISSUE_EOF,
 424	TRF7970A_ST_LISTENING,
 425	TRF7970A_ST_LISTENING_MD,
 426	TRF7970A_ST_MAX
 427};
 428
 429struct trf7970a {
 430	enum trf7970a_state		state;
 431	struct device			*dev;
 432	struct spi_device		*spi;
 433	struct regulator		*vin_regulator;
 434	struct regulator		*vddio_regulator;
 435	struct nfc_digital_dev		*ddev;
 436	u32				quirks;
 437	bool				is_initiator;
 438	bool				aborting;
 439	struct sk_buff			*tx_skb;
 440	struct sk_buff			*rx_skb;
 441	nfc_digital_cmd_complete_t	cb;
 442	void				*cb_arg;
 443	u8				chip_status_ctrl;
 444	u8				iso_ctrl;
 445	u8				iso_ctrl_tech;
 446	u8				modulator_sys_clk_ctrl;
 447	u8				special_fcn_reg1;
 448	u8				io_ctrl;
 449	unsigned int			guard_time;
 450	int				technology;
 451	int				framing;
 452	u8				md_rf_tech;
 453	u8				tx_cmd;
 454	bool				issue_eof;
 455	struct gpio_desc		*en_gpiod;
 456	struct gpio_desc		*en2_gpiod;
 457	struct mutex			lock;
 458	unsigned int			timeout;
 459	bool				ignore_timeout;
 460	struct delayed_work		timeout_work;
 461	u8				rx_gain_reduction;
 462	bool			custom_rx_gain_reduction;
 463};
 464
 465static int trf7970a_cmd(struct trf7970a *trf, u8 opcode)
 466{
 467	u8 cmd = TRF7970A_CMD_BIT_CTRL | TRF7970A_CMD_BIT_OPCODE(opcode);
 468	int ret;
 469
 470	dev_dbg(trf->dev, "cmd: 0x%x\n", cmd);
 471
 472	ret = spi_write(trf->spi, &cmd, 1);
 473	if (ret)
 474		dev_err(trf->dev, "%s - cmd: 0x%x, ret: %d\n", __func__, cmd,
 475			ret);
 476	return ret;
 477}
 478
 479static int trf7970a_read(struct trf7970a *trf, u8 reg, u8 *val)
 480{
 481	u8 addr = TRF7970A_CMD_BIT_RW | reg;
 482	int ret;
 483
 484	ret = spi_write_then_read(trf->spi, &addr, 1, val, 1);
 485	if (ret)
 486		dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
 487			ret);
 488
 489	dev_dbg(trf->dev, "read(0x%x): 0x%x\n", addr, *val);
 490
 491	return ret;
 492}
 493
 494static int trf7970a_read_cont(struct trf7970a *trf, u8 reg, u8 *buf,
 495			      size_t len)
 496{
 497	u8 addr = reg | TRF7970A_CMD_BIT_RW | TRF7970A_CMD_BIT_CONTINUOUS;
 498	struct spi_transfer t[2];
 499	struct spi_message m;
 500	int ret;
 501
 502	dev_dbg(trf->dev, "read_cont(0x%x, %zd)\n", addr, len);
 503
 504	spi_message_init(&m);
 505
 506	memset(&t, 0, sizeof(t));
 507
 508	t[0].tx_buf = &addr;
 509	t[0].len = sizeof(addr);
 510	spi_message_add_tail(&t[0], &m);
 511
 512	t[1].rx_buf = buf;
 513	t[1].len = len;
 514	spi_message_add_tail(&t[1], &m);
 515
 516	ret = spi_sync(trf->spi, &m);
 517	if (ret)
 518		dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
 519			ret);
 520	return ret;
 521}
 522
 523static int trf7970a_write(struct trf7970a *trf, u8 reg, u8 val)
 524{
 525	u8 buf[2] = { reg, val };
 526	int ret;
 527
 528	dev_dbg(trf->dev, "write(0x%x): 0x%x\n", reg, val);
 529
 530	ret = spi_write(trf->spi, buf, 2);
 531	if (ret)
 532		dev_err(trf->dev, "%s - write: 0x%x 0x%x, ret: %d\n", __func__,
 533			buf[0], buf[1], ret);
 534
 535	return ret;
 536}
 537
 538static int trf7970a_read_irqstatus(struct trf7970a *trf, u8 *status)
 539{
 540	int ret;
 541	u8 buf[2];
 542	u8 addr;
 543
 544	addr = TRF7970A_IRQ_STATUS | TRF7970A_CMD_BIT_RW;
 545
 546	if (trf->quirks & TRF7970A_QUIRK_IRQ_STATUS_READ) {
 547		addr |= TRF7970A_CMD_BIT_CONTINUOUS;
 548		ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
 549	} else {
 550		ret = spi_write_then_read(trf->spi, &addr, 1, buf, 1);
 551	}
 552
 553	if (ret)
 554		dev_err(trf->dev, "%s - irqstatus: Status read failed: %d\n",
 555			__func__, ret);
 556	else
 557		*status = buf[0];
 558
 559	return ret;
 560}
 561
 562static int trf7970a_update_rx_gain_reduction(struct trf7970a *trf)
 563{
 564	int ret = 0;
 565	u8 reg;
 566
 567	if (!trf->custom_rx_gain_reduction)
 568		return 0;
 569
 570	ret = trf7970a_read(trf, TRF7970A_RX_SPECIAL_SETTINGS, &reg);
 571	if (ret)
 572		return ret;
 573	reg &= ~(TRF7970A_RX_SPECIAL_SETTINGS_GD_MASK);
 574	reg |= trf->rx_gain_reduction;
 575
 576	ret = trf7970a_write(trf, TRF7970A_RX_SPECIAL_SETTINGS, reg);
 577
 578	return ret;
 579}
 580
 581static int trf7970a_update_iso_ctrl_register(struct trf7970a *trf, u8 iso_ctrl)
 582{
 583	int ret;
 584
 585	ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
 586	if (ret)
 587		return ret;
 588	/*
 589	 * Every time the ISO_CTRL register is written, the RX special setting register is reset by
 590	 * the chip. When a custom gain reguduction is required, it should be rewritten now.
 591	 */
 592	ret = trf7970a_update_rx_gain_reduction(trf);
 593
 594	return ret;
 595}
 596
 597static int trf7970a_read_target_proto(struct trf7970a *trf, u8 *target_proto)
 598{
 599	int ret;
 600	u8 buf[2];
 601	u8 addr;
 602
 603	addr = TRF79070A_NFC_TARGET_PROTOCOL | TRF7970A_CMD_BIT_RW |
 604	       TRF7970A_CMD_BIT_CONTINUOUS;
 605
 606	ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
 607	if (ret)
 608		dev_err(trf->dev, "%s - target_proto: Read failed: %d\n",
 609			__func__, ret);
 610	else
 611		*target_proto = buf[0];
 612
 613	return ret;
 614}
 615
 616static int trf7970a_mode_detect(struct trf7970a *trf, u8 *rf_tech)
 617{
 618	int ret;
 619	u8 target_proto, tech;
 620
 621	ret = trf7970a_read_target_proto(trf, &target_proto);
 622	if (ret)
 623		return ret;
 624
 625	switch (target_proto) {
 626	case TRF79070A_NFC_TARGET_PROTOCOL_106A:
 627		tech = NFC_DIGITAL_RF_TECH_106A;
 628		break;
 629	case TRF79070A_NFC_TARGET_PROTOCOL_106B:
 630		tech = NFC_DIGITAL_RF_TECH_106B;
 631		break;
 632	case TRF79070A_NFC_TARGET_PROTOCOL_212F:
 633		tech = NFC_DIGITAL_RF_TECH_212F;
 634		break;
 635	case TRF79070A_NFC_TARGET_PROTOCOL_424F:
 636		tech = NFC_DIGITAL_RF_TECH_424F;
 637		break;
 638	default:
 639		dev_dbg(trf->dev, "%s - mode_detect: target_proto: 0x%x\n",
 640			__func__, target_proto);
 641		return -EIO;
 642	}
 643
 644	*rf_tech = tech;
 645
 646	return ret;
 647}
 648
 649static void trf7970a_send_upstream(struct trf7970a *trf)
 650{
 651	dev_kfree_skb_any(trf->tx_skb);
 652	trf->tx_skb = NULL;
 653
 654	if (trf->rx_skb && !IS_ERR(trf->rx_skb) && !trf->aborting)
 655		print_hex_dump_debug("trf7970a rx data: ", DUMP_PREFIX_NONE,
 656				     16, 1, trf->rx_skb->data, trf->rx_skb->len,
 657				     false);
 658
 659	trf->state = TRF7970A_ST_IDLE;
 660
 661	if (trf->aborting) {
 662		dev_dbg(trf->dev, "Abort process complete\n");
 663
 664		if (!IS_ERR(trf->rx_skb)) {
 665			kfree_skb(trf->rx_skb);
 666			trf->rx_skb = ERR_PTR(-ECANCELED);
 667		}
 668
 669		trf->aborting = false;
 670	}
 671
 672	trf->cb(trf->ddev, trf->cb_arg, trf->rx_skb);
 673
 674	trf->rx_skb = NULL;
 675}
 676
 677static void trf7970a_send_err_upstream(struct trf7970a *trf, int errno)
 678{
 679	dev_dbg(trf->dev, "Error - state: %d, errno: %d\n", trf->state, errno);
 680
 681	cancel_delayed_work(&trf->timeout_work);
 682
 683	kfree_skb(trf->rx_skb);
 684	trf->rx_skb = ERR_PTR(errno);
 685
 686	trf7970a_send_upstream(trf);
 687}
 688
 689static int trf7970a_transmit(struct trf7970a *trf, struct sk_buff *skb,
 690			     unsigned int len, const u8 *prefix,
 691			     unsigned int prefix_len)
 692{
 693	struct spi_transfer t[2];
 694	struct spi_message m;
 695	unsigned int timeout;
 696	int ret;
 697
 698	print_hex_dump_debug("trf7970a tx data: ", DUMP_PREFIX_NONE,
 699			     16, 1, skb->data, len, false);
 700
 701	spi_message_init(&m);
 702
 703	memset(&t, 0, sizeof(t));
 704
 705	t[0].tx_buf = prefix;
 706	t[0].len = prefix_len;
 707	spi_message_add_tail(&t[0], &m);
 708
 709	t[1].tx_buf = skb->data;
 710	t[1].len = len;
 711	spi_message_add_tail(&t[1], &m);
 712
 713	ret = spi_sync(trf->spi, &m);
 714	if (ret) {
 715		dev_err(trf->dev, "%s - Can't send tx data: %d\n", __func__,
 716			ret);
 717		return ret;
 718	}
 719
 720	skb_pull(skb, len);
 721
 722	if (skb->len > 0) {
 723		trf->state = TRF7970A_ST_WAIT_FOR_TX_FIFO;
 724		timeout = TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT;
 725	} else {
 726		if (trf->issue_eof) {
 727			trf->state = TRF7970A_ST_WAIT_TO_ISSUE_EOF;
 728			timeout = TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF;
 729		} else {
 730			trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
 731
 732			if (!trf->timeout)
 733				timeout = TRF7970A_WAIT_FOR_TX_IRQ;
 734			else
 735				timeout = trf->timeout;
 736		}
 737	}
 738
 739	dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n", timeout,
 740		trf->state);
 741
 742	schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
 743
 744	return 0;
 745}
 746
 747static void trf7970a_fill_fifo(struct trf7970a *trf)
 748{
 749	struct sk_buff *skb = trf->tx_skb;
 750	unsigned int len;
 751	int ret;
 752	u8 fifo_bytes;
 753	u8 prefix;
 754
 755	ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
 756	if (ret) {
 757		trf7970a_send_err_upstream(trf, ret);
 758		return;
 759	}
 760
 761	dev_dbg(trf->dev, "Filling FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
 762
 763	fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 764
 765	/* Calculate how much more data can be written to the fifo */
 766	len = TRF7970A_FIFO_SIZE - fifo_bytes;
 767	if (!len) {
 768		schedule_delayed_work(&trf->timeout_work,
 769			msecs_to_jiffies(TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT));
 770		return;
 771	}
 772
 773	len = min(skb->len, len);
 774
 775	prefix = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_FIFO_IO_REGISTER;
 776
 777	ret = trf7970a_transmit(trf, skb, len, &prefix, sizeof(prefix));
 778	if (ret)
 779		trf7970a_send_err_upstream(trf, ret);
 780}
 781
 782static void trf7970a_drain_fifo(struct trf7970a *trf, u8 status)
 783{
 784	struct sk_buff *skb = trf->rx_skb;
 785	int ret;
 786	u8 fifo_bytes;
 787
 788	if (status & TRF7970A_IRQ_STATUS_ERROR) {
 789		trf7970a_send_err_upstream(trf, -EIO);
 790		return;
 791	}
 792
 793	ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
 794	if (ret) {
 795		trf7970a_send_err_upstream(trf, ret);
 796		return;
 797	}
 798
 799	dev_dbg(trf->dev, "Draining FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
 800
 801	fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 802
 803	if (!fifo_bytes)
 804		goto no_rx_data;
 805
 806	if (fifo_bytes > skb_tailroom(skb)) {
 807		skb = skb_copy_expand(skb, skb_headroom(skb),
 808				      max_t(int, fifo_bytes,
 809					    TRF7970A_RX_SKB_ALLOC_SIZE),
 810				      GFP_KERNEL);
 811		if (!skb) {
 812			trf7970a_send_err_upstream(trf, -ENOMEM);
 813			return;
 814		}
 815
 816		kfree_skb(trf->rx_skb);
 817		trf->rx_skb = skb;
 818	}
 819
 820	ret = trf7970a_read_cont(trf, TRF7970A_FIFO_IO_REGISTER,
 821				 skb_put(skb, fifo_bytes), fifo_bytes);
 822	if (ret) {
 823		trf7970a_send_err_upstream(trf, ret);
 824		return;
 825	}
 826
 827	/* If received Type 2 ACK/NACK, shift right 4 bits and pass up */
 828	if ((trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T) && (skb->len == 1) &&
 829	    (trf->special_fcn_reg1 == TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX)) {
 830		skb->data[0] >>= 4;
 831		status = TRF7970A_IRQ_STATUS_SRX;
 832	} else {
 833		trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA_CONT;
 834
 835		ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
 836		if (ret) {
 837			trf7970a_send_err_upstream(trf, ret);
 838			return;
 839		}
 840
 841		fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 842
 843		/* If there are bytes in the FIFO, set status to '0' so
 844		 * the if stmt below doesn't fire and the driver will wait
 845		 * for the trf7970a to generate another RX interrupt.
 846		 */
 847		if (fifo_bytes)
 848			status = 0;
 849	}
 850
 851no_rx_data:
 852	if (status == TRF7970A_IRQ_STATUS_SRX) {	/* Receive complete */
 853		trf7970a_send_upstream(trf);
 854		return;
 855	}
 856
 857	dev_dbg(trf->dev, "Setting timeout for %d ms\n",
 858		TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT);
 859
 860	schedule_delayed_work(&trf->timeout_work,
 861			   msecs_to_jiffies(TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT));
 862}
 863
 864static irqreturn_t trf7970a_irq(int irq, void *dev_id)
 865{
 866	struct trf7970a *trf = dev_id;
 867	int ret;
 868	u8 status, fifo_bytes, iso_ctrl;
 869
 870	mutex_lock(&trf->lock);
 871
 872	if (trf->state == TRF7970A_ST_RF_OFF) {
 873		mutex_unlock(&trf->lock);
 874		return IRQ_NONE;
 875	}
 876
 877	ret = trf7970a_read_irqstatus(trf, &status);
 878	if (ret) {
 879		mutex_unlock(&trf->lock);
 880		return IRQ_NONE;
 881	}
 882
 883	dev_dbg(trf->dev, "IRQ - state: %d, status: 0x%x\n", trf->state,
 884		status);
 885
 886	if (!status) {
 887		mutex_unlock(&trf->lock);
 888		return IRQ_NONE;
 889	}
 890
 891	switch (trf->state) {
 892	case TRF7970A_ST_IDLE:
 893	case TRF7970A_ST_IDLE_RX_BLOCKED:
 894		/* If initiator and getting interrupts caused by RF noise,
 895		 * turn off the receiver to avoid unnecessary interrupts.
 896		 * It will be turned back on in trf7970a_send_cmd() when
 897		 * the next command is issued.
 898		 */
 899		if (trf->is_initiator && (status & TRF7970A_IRQ_STATUS_ERROR)) {
 900			trf7970a_cmd(trf, TRF7970A_CMD_BLOCK_RX);
 901			trf->state = TRF7970A_ST_IDLE_RX_BLOCKED;
 902		}
 903
 904		trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 905		break;
 906	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
 907		if (status & TRF7970A_IRQ_STATUS_TX) {
 908			trf->ignore_timeout =
 909			    !cancel_delayed_work(&trf->timeout_work);
 910			trf7970a_fill_fifo(trf);
 911		} else {
 912			trf7970a_send_err_upstream(trf, -EIO);
 913		}
 914		break;
 915	case TRF7970A_ST_WAIT_FOR_RX_DATA:
 916	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
 917		if (status & TRF7970A_IRQ_STATUS_SRX) {
 918			trf->ignore_timeout =
 919			    !cancel_delayed_work(&trf->timeout_work);
 920			trf7970a_drain_fifo(trf, status);
 921		} else if (status & TRF7970A_IRQ_STATUS_FIFO) {
 922			ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS,
 923					    &fifo_bytes);
 924
 925			fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 926
 927			if (ret)
 928				trf7970a_send_err_upstream(trf, ret);
 929			else if (!fifo_bytes)
 930				trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 931		} else if ((status == TRF7970A_IRQ_STATUS_TX) ||
 932			   (!trf->is_initiator &&
 933			    (status == (TRF7970A_IRQ_STATUS_TX |
 934					TRF7970A_IRQ_STATUS_NFC_RF)))) {
 935			trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 936
 937			if (!trf->timeout) {
 938				trf->ignore_timeout =
 939				    !cancel_delayed_work(&trf->timeout_work);
 940				trf->rx_skb = ERR_PTR(0);
 941				trf7970a_send_upstream(trf);
 942				break;
 943			}
 944
 945			if (trf->is_initiator)
 946				break;
 947
 948			iso_ctrl = trf->iso_ctrl;
 949
 950			switch (trf->framing) {
 951			case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
 952				trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
 953				iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
 954				trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
 955				break;
 956			case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
 957				trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
 958				iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
 959				trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
 960				break;
 961			case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
 962				ret = trf7970a_write(trf,
 963					 TRF7970A_SPECIAL_FCN_REG1,
 964					 TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL);
 965				if (ret)
 966					goto err_unlock_exit;
 967
 968				trf->special_fcn_reg1 =
 969				    TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL;
 970				break;
 971			default:
 972				break;
 973			}
 974
 975			if (iso_ctrl != trf->iso_ctrl) {
 976				ret = trf7970a_update_iso_ctrl_register(trf, iso_ctrl);
 977				if (ret)
 978					goto err_unlock_exit;
 979
 980				trf->iso_ctrl = iso_ctrl;
 981			}
 982		} else {
 983			trf7970a_send_err_upstream(trf, -EIO);
 984		}
 985		break;
 986	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
 987		if (status != TRF7970A_IRQ_STATUS_TX)
 988			trf7970a_send_err_upstream(trf, -EIO);
 989		break;
 990	case TRF7970A_ST_LISTENING:
 991		if (status & TRF7970A_IRQ_STATUS_SRX) {
 992			trf->ignore_timeout =
 993			    !cancel_delayed_work(&trf->timeout_work);
 994			trf7970a_drain_fifo(trf, status);
 995		} else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
 996			trf7970a_send_err_upstream(trf, -EIO);
 997		}
 998		break;
 999	case TRF7970A_ST_LISTENING_MD:
1000		if (status & TRF7970A_IRQ_STATUS_SRX) {
1001			trf->ignore_timeout =
1002			    !cancel_delayed_work(&trf->timeout_work);
1003
1004			ret = trf7970a_mode_detect(trf, &trf->md_rf_tech);
1005			if (ret) {
1006				trf7970a_send_err_upstream(trf, ret);
1007			} else {
1008				trf->state = TRF7970A_ST_LISTENING;
1009				trf7970a_drain_fifo(trf, status);
1010			}
1011		} else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
1012			trf7970a_send_err_upstream(trf, -EIO);
1013		}
1014		break;
1015	default:
1016		dev_err(trf->dev, "%s - Driver in invalid state: %d\n",
1017			__func__, trf->state);
1018	}
1019
1020err_unlock_exit:
1021	mutex_unlock(&trf->lock);
1022	return IRQ_HANDLED;
1023}
1024
1025static void trf7970a_issue_eof(struct trf7970a *trf)
1026{
1027	int ret;
1028
1029	dev_dbg(trf->dev, "Issuing EOF\n");
1030
1031	ret = trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
1032	if (ret)
1033		trf7970a_send_err_upstream(trf, ret);
1034
1035	ret = trf7970a_cmd(trf, TRF7970A_CMD_EOF);
1036	if (ret)
1037		trf7970a_send_err_upstream(trf, ret);
1038
1039	trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
1040
1041	dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n",
1042		trf->timeout, trf->state);
1043
1044	schedule_delayed_work(&trf->timeout_work,
1045			      msecs_to_jiffies(trf->timeout));
1046}
1047
1048static void trf7970a_timeout_work_handler(struct work_struct *work)
1049{
1050	struct trf7970a *trf = container_of(work, struct trf7970a,
1051					    timeout_work.work);
1052
1053	dev_dbg(trf->dev, "Timeout - state: %d, ignore_timeout: %d\n",
1054		trf->state, trf->ignore_timeout);
1055
1056	mutex_lock(&trf->lock);
1057
1058	if (trf->ignore_timeout)
1059		trf->ignore_timeout = false;
1060	else if (trf->state == TRF7970A_ST_WAIT_FOR_RX_DATA_CONT)
1061		trf7970a_drain_fifo(trf, TRF7970A_IRQ_STATUS_SRX);
1062	else if (trf->state == TRF7970A_ST_WAIT_TO_ISSUE_EOF)
1063		trf7970a_issue_eof(trf);
1064	else
1065		trf7970a_send_err_upstream(trf, -ETIMEDOUT);
1066
1067	mutex_unlock(&trf->lock);
1068}
1069
1070static int trf7970a_init(struct trf7970a *trf)
1071{
1072	int ret;
1073
1074	dev_dbg(trf->dev, "Initializing device - state: %d\n", trf->state);
1075
1076	ret = trf7970a_cmd(trf, TRF7970A_CMD_SOFT_INIT);
1077	if (ret)
1078		goto err_out;
1079
1080	/* Set the gain reduction after soft init */
1081	ret = trf7970a_update_rx_gain_reduction(trf);
1082	if (ret)
1083		goto err_out;
1084
1085	ret = trf7970a_cmd(trf, TRF7970A_CMD_IDLE);
1086	if (ret)
1087		goto err_out;
1088
1089	ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1090			     trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1091	if (ret)
1092		goto err_out;
1093
1094	ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1095	if (ret)
1096		goto err_out;
1097
1098	usleep_range(1000, 2000);
1099
1100	trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1101
1102	ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1103			     trf->modulator_sys_clk_ctrl);
1104	if (ret)
1105		goto err_out;
1106
1107	ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS,
1108			     TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 |
1109			     TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32);
1110	if (ret)
1111		goto err_out;
1112
1113	ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1, 0);
1114	if (ret)
1115		goto err_out;
1116
1117	trf->special_fcn_reg1 = 0;
1118
1119	trf->iso_ctrl = 0xff;
1120	return 0;
1121
1122err_out:
1123	dev_dbg(trf->dev, "Couldn't init device: %d\n", ret);
1124	return ret;
1125}
1126
1127static void trf7970a_switch_rf_off(struct trf7970a *trf)
1128{
1129	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1130	    (trf->state == TRF7970A_ST_RF_OFF))
1131		return;
1132
1133	dev_dbg(trf->dev, "Switching rf off\n");
1134
1135	trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1136
1137	trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, trf->chip_status_ctrl);
1138
1139	trf->aborting = false;
1140	trf->state = TRF7970A_ST_RF_OFF;
1141
1142	pm_runtime_mark_last_busy(trf->dev);
1143	pm_runtime_put_autosuspend(trf->dev);
1144}
1145
1146static int trf7970a_switch_rf_on(struct trf7970a *trf)
1147{
1148	int ret;
1149
1150	dev_dbg(trf->dev, "Switching rf on\n");
1151
1152	pm_runtime_get_sync(trf->dev);
1153
1154	if (trf->state != TRF7970A_ST_RF_OFF) {	/* Power on, RF off */
1155		dev_err(trf->dev, "%s - Incorrect state: %d\n", __func__,
1156			trf->state);
1157		return -EINVAL;
1158	}
1159
1160	ret = trf7970a_init(trf);
1161	if (ret) {
1162		dev_err(trf->dev, "%s - Can't initialize: %d\n", __func__, ret);
1163		return ret;
1164	}
1165
1166	trf->state = TRF7970A_ST_IDLE;
1167
1168	return 0;
1169}
1170
1171static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on)
1172{
1173	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1174	int ret = 0;
1175
1176	dev_dbg(trf->dev, "Switching RF - state: %d, on: %d\n", trf->state, on);
1177
1178	mutex_lock(&trf->lock);
1179
1180	if (on) {
1181		switch (trf->state) {
1182		case TRF7970A_ST_PWR_OFF:
1183		case TRF7970A_ST_RF_OFF:
1184			ret = trf7970a_switch_rf_on(trf);
1185			break;
1186		case TRF7970A_ST_IDLE:
1187		case TRF7970A_ST_IDLE_RX_BLOCKED:
1188			break;
1189		default:
1190			dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1191				__func__, trf->state, on);
1192			trf7970a_switch_rf_off(trf);
1193			ret = -EINVAL;
1194		}
1195	} else {
1196		switch (trf->state) {
1197		case TRF7970A_ST_PWR_OFF:
1198		case TRF7970A_ST_RF_OFF:
1199			break;
1200		default:
1201			dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1202				__func__, trf->state, on);
1203			ret = -EINVAL;
1204			fallthrough;
1205		case TRF7970A_ST_IDLE:
1206		case TRF7970A_ST_IDLE_RX_BLOCKED:
1207		case TRF7970A_ST_WAIT_FOR_RX_DATA:
1208		case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1209			trf7970a_switch_rf_off(trf);
1210		}
1211	}
1212
1213	mutex_unlock(&trf->lock);
1214	return ret;
1215}
1216
1217static int trf7970a_in_config_rf_tech(struct trf7970a *trf, int tech)
1218{
1219	int ret = 0;
1220
1221	dev_dbg(trf->dev, "rf technology: %d\n", tech);
1222
1223	switch (tech) {
1224	case NFC_DIGITAL_RF_TECH_106A:
1225		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443A_106;
1226		trf->modulator_sys_clk_ctrl =
1227		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1228		    TRF7970A_MODULATOR_DEPTH_OOK;
1229		trf->guard_time = TRF7970A_GUARD_TIME_NFCA;
1230		break;
1231	case NFC_DIGITAL_RF_TECH_106B:
1232		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443B_106;
1233		trf->modulator_sys_clk_ctrl =
1234		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1235		    TRF7970A_MODULATOR_DEPTH_ASK10;
1236		trf->guard_time = TRF7970A_GUARD_TIME_NFCB;
1237		break;
1238	case NFC_DIGITAL_RF_TECH_212F:
1239		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_212;
1240		trf->modulator_sys_clk_ctrl =
1241		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1242		    TRF7970A_MODULATOR_DEPTH_ASK10;
1243		trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1244		break;
1245	case NFC_DIGITAL_RF_TECH_424F:
1246		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_424;
1247		trf->modulator_sys_clk_ctrl =
1248		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1249		    TRF7970A_MODULATOR_DEPTH_ASK10;
1250		trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1251		break;
1252	case NFC_DIGITAL_RF_TECH_ISO15693:
1253		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1254		trf->modulator_sys_clk_ctrl =
1255		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1256		    TRF7970A_MODULATOR_DEPTH_OOK;
1257		trf->guard_time = TRF7970A_GUARD_TIME_15693;
1258		break;
1259	default:
1260		dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1261		return -EINVAL;
1262	}
1263
1264	trf->technology = tech;
1265
1266	/* If in initiator mode and not changing the RF tech due to a
1267	 * PSL sequence (indicated by 'trf->iso_ctrl == 0xff' from
1268	 * trf7970a_init()), clear the NFC Target Detection Level register
1269	 * due to erratum.
1270	 */
1271	if (trf->iso_ctrl == 0xff)
1272		ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1273
1274	return ret;
1275}
1276
1277static int trf7970a_is_rf_field(struct trf7970a *trf, bool *is_rf_field)
1278{
1279	int ret;
1280	u8 rssi;
1281
1282	ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1283			     trf->chip_status_ctrl |
1284			     TRF7970A_CHIP_STATUS_REC_ON);
1285	if (ret)
1286		return ret;
1287
1288	ret = trf7970a_cmd(trf, TRF7970A_CMD_TEST_EXT_RF);
1289	if (ret)
1290		return ret;
1291
1292	usleep_range(50, 60);
1293
1294	ret = trf7970a_read(trf, TRF7970A_RSSI_OSC_STATUS, &rssi);
1295	if (ret)
1296		return ret;
1297
1298	ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1299			     trf->chip_status_ctrl);
1300	if (ret)
1301		return ret;
1302
1303	if (rssi & TRF7970A_RSSI_OSC_STATUS_RSSI_MASK)
1304		*is_rf_field = true;
1305	else
1306		*is_rf_field = false;
1307
1308	return 0;
1309}
1310
1311static int trf7970a_in_config_framing(struct trf7970a *trf, int framing)
1312{
1313	u8 iso_ctrl = trf->iso_ctrl_tech;
1314	bool is_rf_field = false;
1315	int ret;
1316
1317	dev_dbg(trf->dev, "framing: %d\n", framing);
1318
1319	switch (framing) {
1320	case NFC_DIGITAL_FRAMING_NFCA_SHORT:
1321	case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1322		trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1323		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1324		break;
1325	case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1326	case NFC_DIGITAL_FRAMING_NFCA_T4T:
1327	case NFC_DIGITAL_FRAMING_NFCB:
1328	case NFC_DIGITAL_FRAMING_NFCB_T4T:
1329	case NFC_DIGITAL_FRAMING_NFCF:
1330	case NFC_DIGITAL_FRAMING_NFCF_T3T:
1331	case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY:
1332	case NFC_DIGITAL_FRAMING_ISO15693_T5T:
1333	case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1334	case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1335		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1336		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1337		break;
1338	case NFC_DIGITAL_FRAMING_NFCA_T2T:
1339		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1340		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1341		break;
1342	default:
1343		dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1344		return -EINVAL;
1345	}
1346
1347	trf->framing = framing;
1348
1349	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1350		ret = trf7970a_is_rf_field(trf, &is_rf_field);
1351		if (ret)
1352			return ret;
1353
1354		if (is_rf_field)
1355			return -EBUSY;
1356	}
1357
1358	if (iso_ctrl != trf->iso_ctrl) {
1359		ret = trf7970a_update_iso_ctrl_register(trf, iso_ctrl);
1360		if (ret)
1361			return ret;
1362
1363		trf->iso_ctrl = iso_ctrl;
1364
1365		ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1366				     trf->modulator_sys_clk_ctrl);
1367		if (ret)
1368			return ret;
1369	}
1370
1371	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1372		ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1373				     trf->chip_status_ctrl |
1374				     TRF7970A_CHIP_STATUS_RF_ON);
1375		if (ret)
1376			return ret;
1377
1378		trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1379
1380		usleep_range(trf->guard_time, trf->guard_time + 1000);
1381	}
1382
1383	return 0;
1384}
1385
1386static int trf7970a_in_configure_hw(struct nfc_digital_dev *ddev, int type,
1387				    int param)
1388{
1389	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1390	int ret;
1391
1392	dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1393
1394	mutex_lock(&trf->lock);
1395
1396	trf->is_initiator = true;
1397
1398	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1399	    (trf->state == TRF7970A_ST_RF_OFF)) {
1400		ret = trf7970a_switch_rf_on(trf);
1401		if (ret)
1402			goto err_unlock;
1403	}
1404
1405	switch (type) {
1406	case NFC_DIGITAL_CONFIG_RF_TECH:
1407		ret = trf7970a_in_config_rf_tech(trf, param);
1408		break;
1409	case NFC_DIGITAL_CONFIG_FRAMING:
1410		ret = trf7970a_in_config_framing(trf, param);
1411		break;
1412	default:
1413		dev_dbg(trf->dev, "Unknown type: %d\n", type);
1414		ret = -EINVAL;
1415	}
1416
1417err_unlock:
1418	mutex_unlock(&trf->lock);
1419	return ret;
1420}
1421
1422static int trf7970a_is_iso15693_write_or_lock(u8 cmd)
1423{
1424	switch (cmd) {
1425	case ISO15693_CMD_WRITE_SINGLE_BLOCK:
1426	case ISO15693_CMD_LOCK_BLOCK:
1427	case ISO15693_CMD_WRITE_MULTIPLE_BLOCK:
1428	case ISO15693_CMD_WRITE_AFI:
1429	case ISO15693_CMD_LOCK_AFI:
1430	case ISO15693_CMD_WRITE_DSFID:
1431	case ISO15693_CMD_LOCK_DSFID:
1432		return 1;
1433	default:
1434		return 0;
1435	}
1436}
1437
1438static int trf7970a_per_cmd_config(struct trf7970a *trf,
1439				   const struct sk_buff *skb)
1440{
1441	const u8 *req = skb->data;
1442	u8 special_fcn_reg1, iso_ctrl;
1443	int ret;
1444
1445	trf->issue_eof = false;
1446
1447	/* When issuing Type 2 read command, make sure the '4_bit_RX' bit in
1448	 * special functions register 1 is cleared; otherwise, its a write or
1449	 * sector select command and '4_bit_RX' must be set.
1450	 *
1451	 * When issuing an ISO 15693 command, inspect the flags byte to see
1452	 * what speed to use.  Also, remember if the OPTION flag is set on
1453	 * a Type 5 write or lock command so the driver will know that it
1454	 * has to send an EOF in order to get a response.
1455	 */
1456	if ((trf->technology == NFC_DIGITAL_RF_TECH_106A) &&
1457	    (trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T)) {
1458		if (req[0] == NFC_T2T_CMD_READ)
1459			special_fcn_reg1 = 0;
1460		else
1461			special_fcn_reg1 = TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX;
1462
1463		if (special_fcn_reg1 != trf->special_fcn_reg1) {
1464			ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1,
1465					     special_fcn_reg1);
1466			if (ret)
1467				return ret;
1468
1469			trf->special_fcn_reg1 = special_fcn_reg1;
1470		}
1471	} else if (trf->technology == NFC_DIGITAL_RF_TECH_ISO15693) {
1472		iso_ctrl = trf->iso_ctrl & ~TRF7970A_ISO_CTRL_RFID_SPEED_MASK;
1473
1474		switch (req[0] & ISO15693_REQ_FLAG_SPEED_MASK) {
1475		case 0x00:
1476			iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_662;
1477			break;
1478		case ISO15693_REQ_FLAG_SUB_CARRIER:
1479			iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a;
1480			break;
1481		case ISO15693_REQ_FLAG_DATA_RATE:
1482			iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1483			break;
1484		case (ISO15693_REQ_FLAG_SUB_CARRIER |
1485		      ISO15693_REQ_FLAG_DATA_RATE):
1486			iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669;
1487			break;
1488		}
1489
1490		if (iso_ctrl != trf->iso_ctrl) {
1491			ret = trf7970a_update_iso_ctrl_register(trf, iso_ctrl);
1492			if (ret)
1493				return ret;
1494
1495			trf->iso_ctrl = iso_ctrl;
1496		}
1497
1498		if ((trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) &&
1499		    trf7970a_is_iso15693_write_or_lock(req[1]) &&
1500		    (req[0] & ISO15693_REQ_FLAG_OPTION))
1501			trf->issue_eof = true;
1502	}
1503
1504	return 0;
1505}
1506
1507static int trf7970a_send_cmd(struct nfc_digital_dev *ddev,
1508			     struct sk_buff *skb, u16 timeout,
1509			     nfc_digital_cmd_complete_t cb, void *arg)
1510{
1511	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1512	u8 prefix[5];
1513	unsigned int len;
1514	int ret;
1515	u8 status;
1516
1517	dev_dbg(trf->dev, "New request - state: %d, timeout: %d ms, len: %d\n",
1518		trf->state, timeout, skb->len);
1519
1520	if (skb->len > TRF7970A_TX_MAX)
1521		return -EINVAL;
1522
1523	mutex_lock(&trf->lock);
1524
1525	if ((trf->state != TRF7970A_ST_IDLE) &&
1526	    (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1527		dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1528			trf->state);
1529		ret = -EIO;
1530		goto out_err;
1531	}
1532
1533	if (trf->aborting) {
1534		dev_dbg(trf->dev, "Abort process complete\n");
1535		trf->aborting = false;
1536		ret = -ECANCELED;
1537		goto out_err;
1538	}
1539
1540	if (timeout) {
1541		trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1542						 GFP_KERNEL);
1543		if (!trf->rx_skb) {
1544			dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1545			ret = -ENOMEM;
1546			goto out_err;
1547		}
1548	}
1549
1550	if (trf->state == TRF7970A_ST_IDLE_RX_BLOCKED) {
1551		ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1552		if (ret)
1553			goto out_err;
1554
1555		trf->state = TRF7970A_ST_IDLE;
1556	}
1557
1558	if (trf->is_initiator) {
1559		ret = trf7970a_per_cmd_config(trf, skb);
1560		if (ret)
1561			goto out_err;
1562	}
1563
1564	trf->ddev = ddev;
1565	trf->tx_skb = skb;
1566	trf->cb = cb;
1567	trf->cb_arg = arg;
1568	trf->timeout = timeout;
1569	trf->ignore_timeout = false;
1570
1571	len = skb->len;
1572
1573	/* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
1574	 * on what the current framing is, the address of the TX length byte 1
1575	 * register (0x1d), and the 2 byte length of the data to be transmitted.
1576	 * That totals 5 bytes.
1577	 */
1578	prefix[0] = TRF7970A_CMD_BIT_CTRL |
1579	    TRF7970A_CMD_BIT_OPCODE(TRF7970A_CMD_FIFO_RESET);
1580	prefix[1] = TRF7970A_CMD_BIT_CTRL |
1581	    TRF7970A_CMD_BIT_OPCODE(trf->tx_cmd);
1582	prefix[2] = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_TX_LENGTH_BYTE1;
1583
1584	if (trf->framing == NFC_DIGITAL_FRAMING_NFCA_SHORT) {
1585		prefix[3] = 0x00;
1586		prefix[4] = 0x0f;	/* 7 bits */
1587	} else {
1588		prefix[3] = (len & 0xf00) >> 4;
1589		prefix[3] |= ((len & 0xf0) >> 4);
1590		prefix[4] = ((len & 0x0f) << 4);
1591	}
1592
1593	len = min_t(int, skb->len, TRF7970A_FIFO_SIZE);
1594
1595	/* Clear possible spurious interrupt */
1596	ret = trf7970a_read_irqstatus(trf, &status);
1597	if (ret)
1598		goto out_err;
1599
1600	ret = trf7970a_transmit(trf, skb, len, prefix, sizeof(prefix));
1601	if (ret) {
1602		kfree_skb(trf->rx_skb);
1603		trf->rx_skb = NULL;
1604	}
1605
1606out_err:
1607	mutex_unlock(&trf->lock);
1608	return ret;
1609}
1610
1611static int trf7970a_tg_config_rf_tech(struct trf7970a *trf, int tech)
1612{
1613	int ret = 0;
1614
1615	dev_dbg(trf->dev, "rf technology: %d\n", tech);
1616
1617	switch (tech) {
1618	case NFC_DIGITAL_RF_TECH_106A:
1619		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1620		    TRF7970A_ISO_CTRL_NFC_CE | TRF7970A_ISO_CTRL_NFC_CE_14443A;
1621		trf->modulator_sys_clk_ctrl =
1622		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1623		    TRF7970A_MODULATOR_DEPTH_OOK;
1624		break;
1625	case NFC_DIGITAL_RF_TECH_212F:
1626		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1627		    TRF7970A_ISO_CTRL_NFC_NFCF_212;
1628		trf->modulator_sys_clk_ctrl =
1629		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1630		    TRF7970A_MODULATOR_DEPTH_ASK10;
1631		break;
1632	case NFC_DIGITAL_RF_TECH_424F:
1633		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1634		    TRF7970A_ISO_CTRL_NFC_NFCF_424;
1635		trf->modulator_sys_clk_ctrl =
1636		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1637		    TRF7970A_MODULATOR_DEPTH_ASK10;
1638		break;
1639	default:
1640		dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1641		return -EINVAL;
1642	}
1643
1644	trf->technology = tech;
1645
1646	/* Normally we write the ISO_CTRL register in
1647	 * trf7970a_tg_config_framing() because the framing can change
1648	 * the value written.  However, when sending a PSL RES,
1649	 * digital_tg_send_psl_res_complete() doesn't call
1650	 * trf7970a_tg_config_framing() so we must write the register
1651	 * here.
1652	 */
1653	if ((trf->framing == NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED) &&
1654	    (trf->iso_ctrl_tech != trf->iso_ctrl)) {
1655		ret = trf7970a_update_iso_ctrl_register(trf, trf->iso_ctrl_tech);
1656
1657		trf->iso_ctrl = trf->iso_ctrl_tech;
1658	}
1659
1660	return ret;
1661}
1662
1663/* Since this is a target routine, several of the framing calls are
1664 * made between receiving the request and sending the response so they
1665 * should take effect until after the response is sent.  This is accomplished
1666 * by skipping the ISO_CTRL register write here and doing it in the interrupt
1667 * handler.
1668 */
1669static int trf7970a_tg_config_framing(struct trf7970a *trf, int framing)
1670{
1671	u8 iso_ctrl = trf->iso_ctrl_tech;
1672	int ret;
1673
1674	dev_dbg(trf->dev, "framing: %d\n", framing);
1675
1676	switch (framing) {
1677	case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1678		trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1679		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1680		break;
1681	case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1682	case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1683	case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
1684		/* These ones are applied in the interrupt handler */
1685		iso_ctrl = trf->iso_ctrl; /* Don't write to ISO_CTRL yet */
1686		break;
1687	case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1688		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1689		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1690		break;
1691	case NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED:
1692		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1693		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1694		break;
1695	default:
1696		dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1697		return -EINVAL;
1698	}
1699
1700	trf->framing = framing;
1701
1702	if (iso_ctrl != trf->iso_ctrl) {
1703		ret = trf7970a_update_iso_ctrl_register(trf, iso_ctrl);
1704		if (ret)
1705			return ret;
1706
1707		trf->iso_ctrl = iso_ctrl;
1708
1709		ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1710				     trf->modulator_sys_clk_ctrl);
1711		if (ret)
1712			return ret;
1713	}
1714
1715	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1716		ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1717				     trf->chip_status_ctrl |
1718				     TRF7970A_CHIP_STATUS_RF_ON);
1719		if (ret)
1720			return ret;
1721
1722		trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1723	}
1724
1725	return 0;
1726}
1727
1728static int trf7970a_tg_configure_hw(struct nfc_digital_dev *ddev, int type,
1729				    int param)
1730{
1731	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1732	int ret;
1733
1734	dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1735
1736	mutex_lock(&trf->lock);
1737
1738	trf->is_initiator = false;
1739
1740	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1741	    (trf->state == TRF7970A_ST_RF_OFF)) {
1742		ret = trf7970a_switch_rf_on(trf);
1743		if (ret)
1744			goto err_unlock;
1745	}
1746
1747	switch (type) {
1748	case NFC_DIGITAL_CONFIG_RF_TECH:
1749		ret = trf7970a_tg_config_rf_tech(trf, param);
1750		break;
1751	case NFC_DIGITAL_CONFIG_FRAMING:
1752		ret = trf7970a_tg_config_framing(trf, param);
1753		break;
1754	default:
1755		dev_dbg(trf->dev, "Unknown type: %d\n", type);
1756		ret = -EINVAL;
1757	}
1758
1759err_unlock:
1760	mutex_unlock(&trf->lock);
1761	return ret;
1762}
1763
1764static int _trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1765			       nfc_digital_cmd_complete_t cb, void *arg,
1766			       bool mode_detect)
1767{
1768	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1769	int ret;
1770
1771	mutex_lock(&trf->lock);
1772
1773	if ((trf->state != TRF7970A_ST_IDLE) &&
1774	    (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1775		dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1776			trf->state);
1777		ret = -EIO;
1778		goto out_err;
1779	}
1780
1781	if (trf->aborting) {
1782		dev_dbg(trf->dev, "Abort process complete\n");
1783		trf->aborting = false;
1784		ret = -ECANCELED;
1785		goto out_err;
1786	}
1787
1788	trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1789					 GFP_KERNEL);
1790	if (!trf->rx_skb) {
1791		dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1792		ret = -ENOMEM;
1793		goto out_err;
1794	}
1795
1796	ret = trf7970a_write(trf, TRF7970A_RX_SPECIAL_SETTINGS,
1797			     TRF7970A_RX_SPECIAL_SETTINGS_HBT |
1798			     TRF7970A_RX_SPECIAL_SETTINGS_M848 |
1799			     TRF7970A_RX_SPECIAL_SETTINGS_C424 |
1800			     TRF7970A_RX_SPECIAL_SETTINGS_C212);
1801	if (ret)
1802		goto out_err;
1803
1804	ret = trf7970a_update_rx_gain_reduction(trf);
1805	if (ret)
1806		goto out_err;
1807
1808	ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1809			     trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1810	if (ret)
1811		goto out_err;
1812
1813	ret = trf7970a_write(trf, TRF7970A_NFC_LOW_FIELD_LEVEL,
1814			     TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(0x3));
1815	if (ret)
1816		goto out_err;
1817
1818	ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL,
1819			     TRF7970A_NFC_TARGET_LEVEL_RFDET(0x7));
1820	if (ret)
1821		goto out_err;
1822
1823	trf->ddev = ddev;
1824	trf->cb = cb;
1825	trf->cb_arg = arg;
1826	trf->timeout = timeout;
1827	trf->ignore_timeout = false;
1828
1829	ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1830	if (ret)
1831		goto out_err;
1832
1833	trf->state = mode_detect ? TRF7970A_ST_LISTENING_MD :
1834				   TRF7970A_ST_LISTENING;
1835
1836	schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
1837
1838out_err:
1839	mutex_unlock(&trf->lock);
1840	return ret;
1841}
1842
1843static int trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1844			      nfc_digital_cmd_complete_t cb, void *arg)
1845{
1846	const struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1847
1848	dev_dbg(trf->dev, "Listen - state: %d, timeout: %d ms\n",
1849		trf->state, timeout);
1850
1851	return _trf7970a_tg_listen(ddev, timeout, cb, arg, false);
1852}
1853
1854static int trf7970a_tg_listen_md(struct nfc_digital_dev *ddev,
1855				 u16 timeout, nfc_digital_cmd_complete_t cb,
1856				 void *arg)
1857{
1858	const struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1859	int ret;
1860
1861	dev_dbg(trf->dev, "Listen MD - state: %d, timeout: %d ms\n",
1862		trf->state, timeout);
1863
1864	ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
1865				       NFC_DIGITAL_RF_TECH_106A);
1866	if (ret)
1867		return ret;
1868
1869	ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1870				       NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
1871	if (ret)
1872		return ret;
1873
1874	return _trf7970a_tg_listen(ddev, timeout, cb, arg, true);
1875}
1876
1877static int trf7970a_tg_get_rf_tech(struct nfc_digital_dev *ddev, u8 *rf_tech)
1878{
1879	const struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1880
1881	dev_dbg(trf->dev, "Get RF Tech - state: %d, rf_tech: %d\n",
1882		trf->state, trf->md_rf_tech);
1883
1884	*rf_tech = trf->md_rf_tech;
1885
1886	return 0;
1887}
1888
1889static void trf7970a_abort_cmd(struct nfc_digital_dev *ddev)
1890{
1891	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1892
1893	dev_dbg(trf->dev, "Abort process initiated\n");
1894
1895	mutex_lock(&trf->lock);
1896
1897	switch (trf->state) {
1898	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1899	case TRF7970A_ST_WAIT_FOR_RX_DATA:
1900	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1901	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1902		trf->aborting = true;
1903		break;
1904	case TRF7970A_ST_LISTENING:
1905		trf->ignore_timeout = !cancel_delayed_work(&trf->timeout_work);
1906		trf7970a_send_err_upstream(trf, -ECANCELED);
1907		dev_dbg(trf->dev, "Abort process complete\n");
1908		break;
1909	default:
1910		break;
1911	}
1912
1913	mutex_unlock(&trf->lock);
1914}
1915
1916static const struct nfc_digital_ops trf7970a_nfc_ops = {
1917	.in_configure_hw	= trf7970a_in_configure_hw,
1918	.in_send_cmd		= trf7970a_send_cmd,
1919	.tg_configure_hw	= trf7970a_tg_configure_hw,
1920	.tg_send_cmd		= trf7970a_send_cmd,
1921	.tg_listen		= trf7970a_tg_listen,
1922	.tg_listen_md		= trf7970a_tg_listen_md,
1923	.tg_get_rf_tech		= trf7970a_tg_get_rf_tech,
1924	.switch_rf		= trf7970a_switch_rf,
1925	.abort_cmd		= trf7970a_abort_cmd,
1926};
1927
1928static int trf7970a_power_up(struct trf7970a *trf)
1929{
1930	int ret;
1931
1932	dev_dbg(trf->dev, "Powering up - state: %d\n", trf->state);
1933
1934	if (trf->state != TRF7970A_ST_PWR_OFF)
1935		return 0;
1936
1937	ret = regulator_enable(trf->vin_regulator);
1938	if (ret) {
1939		dev_err(trf->dev, "%s - Can't enable VIN: %d\n", __func__, ret);
1940		return ret;
1941	}
1942
1943	usleep_range(5000, 6000);
1944
1945	if (trf->en2_gpiod &&
1946	    !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW)) {
1947		gpiod_set_value_cansleep(trf->en2_gpiod, 1);
1948		usleep_range(1000, 2000);
1949	}
1950
1951	gpiod_set_value_cansleep(trf->en_gpiod, 1);
1952
1953	usleep_range(20000, 21000);
1954
1955	trf->state = TRF7970A_ST_RF_OFF;
1956
1957	return 0;
1958}
1959
1960static int trf7970a_power_down(struct trf7970a *trf)
1961{
1962	int ret;
1963
1964	dev_dbg(trf->dev, "Powering down - state: %d\n", trf->state);
1965
1966	if (trf->state == TRF7970A_ST_PWR_OFF)
1967		return 0;
1968
1969	if (trf->state != TRF7970A_ST_RF_OFF) {
1970		dev_dbg(trf->dev, "Can't power down - not RF_OFF state (%d)\n",
1971			trf->state);
1972		return -EBUSY;
1973	}
1974
1975	gpiod_set_value_cansleep(trf->en_gpiod, 0);
1976
1977	if (trf->en2_gpiod && !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW))
1978		gpiod_set_value_cansleep(trf->en2_gpiod, 0);
1979
1980	ret = regulator_disable(trf->vin_regulator);
1981	if (ret)
1982		dev_err(trf->dev, "%s - Can't disable VIN: %d\n", __func__,
1983			ret);
1984
1985	trf->state = TRF7970A_ST_PWR_OFF;
1986
1987	return ret;
1988}
1989
1990static int trf7970a_startup(struct trf7970a *trf)
1991{
1992	int ret;
1993
1994	ret = trf7970a_power_up(trf);
1995	if (ret)
1996		return ret;
1997
1998	ret = trf7970a_update_rx_gain_reduction(trf);
1999	if (ret)
2000		return ret;
2001
2002	pm_runtime_set_active(trf->dev);
2003	pm_runtime_enable(trf->dev);
2004	pm_runtime_mark_last_busy(trf->dev);
2005
2006	return 0;
2007}
2008
2009static void trf7970a_shutdown(struct trf7970a *trf)
2010{
2011	switch (trf->state) {
2012	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
2013	case TRF7970A_ST_WAIT_FOR_RX_DATA:
2014	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
2015	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
2016	case TRF7970A_ST_LISTENING:
2017		trf7970a_send_err_upstream(trf, -ECANCELED);
2018		fallthrough;
2019	case TRF7970A_ST_IDLE:
2020	case TRF7970A_ST_IDLE_RX_BLOCKED:
2021		trf7970a_switch_rf_off(trf);
2022		break;
2023	default:
2024		break;
2025	}
2026
2027	pm_runtime_disable(trf->dev);
2028	pm_runtime_set_suspended(trf->dev);
2029
2030	trf7970a_power_down(trf);
2031}
2032
2033static int trf7970a_get_autosuspend_delay(const struct device_node *np)
2034{
2035	int autosuspend_delay, ret;
2036
2037	ret = of_property_read_u32(np, "autosuspend-delay", &autosuspend_delay);
2038	if (ret)
2039		autosuspend_delay = TRF7970A_AUTOSUSPEND_DELAY;
2040
2041	return autosuspend_delay;
2042}
2043
2044static int trf7970a_probe(struct spi_device *spi)
2045{
2046	const struct device_node *np = spi->dev.of_node;
2047	struct trf7970a *trf;
2048	int uvolts, autosuspend_delay, ret;
2049	u32 clk_freq = TRF7970A_13MHZ_CLOCK_FREQUENCY;
2050	u32 rx_gain_reduction_db;
2051
2052	if (!np) {
2053		dev_err(&spi->dev, "No Device Tree entry\n");
2054		return -EINVAL;
2055	}
2056
2057	trf = devm_kzalloc(&spi->dev, sizeof(*trf), GFP_KERNEL);
2058	if (!trf)
2059		return -ENOMEM;
2060
2061	trf->state = TRF7970A_ST_PWR_OFF;
2062	trf->dev = &spi->dev;
2063	trf->spi = spi;
2064
2065	spi->mode = SPI_MODE_1;
2066	spi->bits_per_word = 8;
2067
2068	ret = spi_setup(spi);
2069	if (ret < 0) {
2070		dev_err(trf->dev, "Can't set up SPI Communication\n");
2071		return ret;
2072	}
2073
2074	if (of_property_read_bool(np, "irq-status-read-quirk"))
2075		trf->quirks |= TRF7970A_QUIRK_IRQ_STATUS_READ;
2076
2077	/* There are two enable pins - only EN must be present in the DT */
2078	trf->en_gpiod = devm_gpiod_get_index(trf->dev, "ti,enable", 0,
2079					     GPIOD_OUT_LOW);
2080	if (IS_ERR(trf->en_gpiod)) {
2081		dev_err(trf->dev, "No EN GPIO property\n");
2082		return PTR_ERR(trf->en_gpiod);
2083	}
2084
2085	trf->en2_gpiod = devm_gpiod_get_index_optional(trf->dev, "ti,enable", 1,
2086						       GPIOD_OUT_LOW);
2087	if (!trf->en2_gpiod) {
2088		dev_info(trf->dev, "No EN2 GPIO property\n");
2089	} else if (IS_ERR(trf->en2_gpiod)) {
2090		dev_err(trf->dev, "Error getting EN2 GPIO property: %ld\n",
2091			PTR_ERR(trf->en2_gpiod));
2092		return PTR_ERR(trf->en2_gpiod);
2093	} else if (of_property_read_bool(np, "en2-rf-quirk")) {
2094		trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;
2095	}
2096
2097	of_property_read_u32(np, "clock-frequency", &clk_freq);
2098	if ((clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY) &&
2099	    (clk_freq != TRF7970A_13MHZ_CLOCK_FREQUENCY)) {
2100		dev_err(trf->dev,
2101			"clock-frequency (%u Hz) unsupported\n", clk_freq);
2102		return -EINVAL;
2103	}
2104
2105	if (clk_freq == TRF7970A_27MHZ_CLOCK_FREQUENCY) {
2106		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_27MHZ;
2107		dev_dbg(trf->dev, "trf7970a configured for 27MHz crystal\n");
2108	} else {
2109		trf->modulator_sys_clk_ctrl = 0;
2110	}
2111
2112	if (of_property_read_u32(np, "ti,rx-gain-reduction-db", &rx_gain_reduction_db) == 0) {
2113		if (rx_gain_reduction_db > TRF7970A_RX_GAIN_REDUCTION_MAX_DB) {
2114			dev_warn(trf->dev, "RX Gain reduction too high. Ignored\n");
2115		} else if ((rx_gain_reduction_db % TRF7970A_RX_GAIN_REDUCTION_DB_PER_LSB)) {
2116			dev_warn(trf->dev, "RX Gain must be set in 5 dB increments. Ignored\n");
2117		} else {
2118			dev_dbg(trf->dev, "RX gain set to -%udB\n", rx_gain_reduction_db);
2119			trf->rx_gain_reduction = ((rx_gain_reduction_db /
2120				TRF7970A_RX_GAIN_REDUCTION_DB_PER_LSB) <<
2121				TRF7970A_RX_SPECIAL_SETTINGS_GD_SHIFT);
2122			trf->custom_rx_gain_reduction = true;
2123		}
2124	}
2125
2126	ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL,
2127					trf7970a_irq,
2128					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
2129					"trf7970a", trf);
2130	if (ret) {
2131		dev_err(trf->dev, "Can't request IRQ#%d: %d\n", spi->irq, ret);
2132		return ret;
2133	}
2134
2135	mutex_init(&trf->lock);
2136	INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
2137
2138	trf->vin_regulator = devm_regulator_get(&spi->dev, "vin");
2139	if (IS_ERR(trf->vin_regulator)) {
2140		ret = PTR_ERR(trf->vin_regulator);
2141		dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret);
2142		goto err_destroy_lock;
2143	}
2144
2145	ret = regulator_enable(trf->vin_regulator);
2146	if (ret) {
2147		dev_err(trf->dev, "Can't enable VIN: %d\n", ret);
2148		goto err_destroy_lock;
2149	}
2150
2151	uvolts = regulator_get_voltage(trf->vin_regulator);
2152	if (uvolts > 4000000)
2153		trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;
2154
2155	trf->vddio_regulator = devm_regulator_get(&spi->dev, "vdd-io");
2156	if (IS_ERR(trf->vddio_regulator)) {
2157		ret = PTR_ERR(trf->vddio_regulator);
2158		dev_err(trf->dev, "Can't get VDD_IO regulator: %d\n", ret);
2159		goto err_disable_vin_regulator;
2160	}
2161
2162	ret = regulator_enable(trf->vddio_regulator);
2163	if (ret) {
2164		dev_err(trf->dev, "Can't enable VDD_IO: %d\n", ret);
2165		goto err_disable_vin_regulator;
2166	}
2167
2168	if (regulator_get_voltage(trf->vddio_regulator) == 1800000) {
2169		trf->io_ctrl = TRF7970A_REG_IO_CTRL_IO_LOW;
2170		dev_dbg(trf->dev, "trf7970a config vdd_io to 1.8V\n");
2171	}
2172
2173	trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,
2174						TRF7970A_SUPPORTED_PROTOCOLS,
2175						NFC_DIGITAL_DRV_CAPS_IN_CRC |
2176						NFC_DIGITAL_DRV_CAPS_TG_CRC, 0,
2177						0);
2178	if (!trf->ddev) {
2179		dev_err(trf->dev, "Can't allocate NFC digital device\n");
2180		ret = -ENOMEM;
2181		goto err_disable_vddio_regulator;
2182	}
2183
2184	nfc_digital_set_parent_dev(trf->ddev, trf->dev);
2185	nfc_digital_set_drvdata(trf->ddev, trf);
2186	spi_set_drvdata(spi, trf);
2187
2188	autosuspend_delay = trf7970a_get_autosuspend_delay(np);
2189
2190	pm_runtime_set_autosuspend_delay(trf->dev, autosuspend_delay);
2191	pm_runtime_use_autosuspend(trf->dev);
2192
2193	ret = trf7970a_startup(trf);
2194	if (ret)
2195		goto err_free_ddev;
2196
2197	ret = nfc_digital_register_device(trf->ddev);
2198	if (ret) {
2199		dev_err(trf->dev, "Can't register NFC digital device: %d\n",
2200			ret);
2201		goto err_shutdown;
2202	}
2203
2204	return 0;
2205
2206err_shutdown:
2207	trf7970a_shutdown(trf);
2208err_free_ddev:
2209	nfc_digital_free_device(trf->ddev);
2210err_disable_vddio_regulator:
2211	regulator_disable(trf->vddio_regulator);
2212err_disable_vin_regulator:
2213	regulator_disable(trf->vin_regulator);
2214err_destroy_lock:
2215	mutex_destroy(&trf->lock);
2216	return ret;
2217}
2218
2219static void trf7970a_remove(struct spi_device *spi)
2220{
2221	struct trf7970a *trf = spi_get_drvdata(spi);
2222
2223	mutex_lock(&trf->lock);
2224
2225	trf7970a_shutdown(trf);
2226
2227	mutex_unlock(&trf->lock);
2228
2229	nfc_digital_unregister_device(trf->ddev);
2230	nfc_digital_free_device(trf->ddev);
2231
2232	regulator_disable(trf->vddio_regulator);
2233	regulator_disable(trf->vin_regulator);
2234
2235	mutex_destroy(&trf->lock);
2236}
2237
2238#ifdef CONFIG_PM_SLEEP
2239static int trf7970a_suspend(struct device *dev)
2240{
2241	struct spi_device *spi = to_spi_device(dev);
2242	struct trf7970a *trf = spi_get_drvdata(spi);
2243
2244	mutex_lock(&trf->lock);
2245
2246	trf7970a_shutdown(trf);
2247
2248	mutex_unlock(&trf->lock);
2249
2250	return 0;
2251}
2252
2253static int trf7970a_resume(struct device *dev)
2254{
2255	struct spi_device *spi = to_spi_device(dev);
2256	struct trf7970a *trf = spi_get_drvdata(spi);
2257	int ret;
2258
2259	mutex_lock(&trf->lock);
2260
2261	ret = trf7970a_startup(trf);
2262
2263	mutex_unlock(&trf->lock);
2264
2265	return ret;
2266}
2267#endif
2268
2269#ifdef CONFIG_PM
2270static int trf7970a_pm_runtime_suspend(struct device *dev)
2271{
2272	struct spi_device *spi = to_spi_device(dev);
2273	struct trf7970a *trf = spi_get_drvdata(spi);
2274	int ret;
2275
2276	mutex_lock(&trf->lock);
2277
2278	ret = trf7970a_power_down(trf);
2279
2280	mutex_unlock(&trf->lock);
2281
2282	return ret;
2283}
2284
2285static int trf7970a_pm_runtime_resume(struct device *dev)
2286{
2287	struct spi_device *spi = to_spi_device(dev);
2288	struct trf7970a *trf = spi_get_drvdata(spi);
2289	int ret;
2290
2291	ret = trf7970a_power_up(trf);
2292	if (!ret)
2293		pm_runtime_mark_last_busy(dev);
2294
2295	return ret;
2296}
2297#endif
2298
2299static const struct dev_pm_ops trf7970a_pm_ops = {
2300	SET_SYSTEM_SLEEP_PM_OPS(trf7970a_suspend, trf7970a_resume)
2301	SET_RUNTIME_PM_OPS(trf7970a_pm_runtime_suspend,
2302			   trf7970a_pm_runtime_resume, NULL)
2303};
2304
2305static const struct of_device_id trf7970a_of_match[] __maybe_unused = {
2306	{.compatible = "ti,trf7970a",},
2307	{},
2308};
2309
2310MODULE_DEVICE_TABLE(of, trf7970a_of_match);
2311
2312static const struct spi_device_id trf7970a_id_table[] = {
2313	{"trf7970a", 0},
2314	{}
2315};
2316
2317MODULE_DEVICE_TABLE(spi, trf7970a_id_table);
2318
2319static struct spi_driver trf7970a_spi_driver = {
2320	.probe		= trf7970a_probe,
2321	.remove		= trf7970a_remove,
2322	.id_table	= trf7970a_id_table,
2323	.driver	= {
2324		.name		= "trf7970a",
2325		.of_match_table	= of_match_ptr(trf7970a_of_match),
2326		.pm		= &trf7970a_pm_ops,
2327	},
2328};
2329
2330module_spi_driver(trf7970a_spi_driver);
2331
2332MODULE_AUTHOR("Mark A. Greer <mgreer@animalcreek.com>");
2333MODULE_LICENSE("GPL v2");
2334MODULE_DESCRIPTION("TI trf7970a RFID/NFC Transceiver Driver");