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_SPECIAL_SETTINGS_NO_LIM	BIT(0)
 276#define TRF7970A_RX_SPECIAL_SETTINGS_AGCR	BIT(1)
 277#define TRF7970A_RX_SPECIAL_SETTINGS_GD_0DB	(0x0 << 2)
 278#define TRF7970A_RX_SPECIAL_SETTINGS_GD_5DB	(0x1 << 2)
 279#define TRF7970A_RX_SPECIAL_SETTINGS_GD_10DB	(0x2 << 2)
 280#define TRF7970A_RX_SPECIAL_SETTINGS_GD_15DB	(0x3 << 2)
 281#define TRF7970A_RX_SPECIAL_SETTINGS_HBT	BIT(4)
 282#define TRF7970A_RX_SPECIAL_SETTINGS_M848	BIT(5)
 283#define TRF7970A_RX_SPECIAL_SETTINGS_C424	BIT(6)
 284#define TRF7970A_RX_SPECIAL_SETTINGS_C212	BIT(7)
 285
 286#define TRF7970A_REG_IO_CTRL_VRS(v)		((v) & 0x07)
 287#define TRF7970A_REG_IO_CTRL_IO_LOW		BIT(5)
 288#define TRF7970A_REG_IO_CTRL_EN_EXT_PA		BIT(6)
 289#define TRF7970A_REG_IO_CTRL_AUTO_REG		BIT(7)
 290
 291/* IRQ Status Register Bits */
 292#define TRF7970A_IRQ_STATUS_NORESP		BIT(0)	/* ISO15693 only */
 293#define TRF7970A_IRQ_STATUS_NFC_COL_ERROR	BIT(0)
 294#define TRF7970A_IRQ_STATUS_COL			BIT(1)
 295#define TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR	BIT(2)
 296#define TRF7970A_IRQ_STATUS_NFC_RF		BIT(2)
 297#define TRF7970A_IRQ_STATUS_PARITY_ERROR	BIT(3)
 298#define TRF7970A_IRQ_STATUS_NFC_SDD		BIT(3)
 299#define TRF7970A_IRQ_STATUS_CRC_ERROR		BIT(4)
 300#define TRF7970A_IRQ_STATUS_NFC_PROTO_ERROR	BIT(4)
 301#define TRF7970A_IRQ_STATUS_FIFO		BIT(5)
 302#define TRF7970A_IRQ_STATUS_SRX			BIT(6)
 303#define TRF7970A_IRQ_STATUS_TX			BIT(7)
 304
 305#define TRF7970A_IRQ_STATUS_ERROR				\
 306		(TRF7970A_IRQ_STATUS_COL |			\
 307		 TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR |	\
 308		 TRF7970A_IRQ_STATUS_PARITY_ERROR |		\
 309		 TRF7970A_IRQ_STATUS_CRC_ERROR)
 310
 311#define TRF7970A_RSSI_OSC_STATUS_RSSI_MASK	(BIT(2) | BIT(1) | BIT(0))
 312#define TRF7970A_RSSI_OSC_STATUS_RSSI_X_MASK	(BIT(5) | BIT(4) | BIT(3))
 313#define TRF7970A_RSSI_OSC_STATUS_RSSI_OSC_OK	BIT(6)
 314
 315#define TRF7970A_SPECIAL_FCN_REG1_COL_7_6		BIT(0)
 316#define TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL		BIT(1)
 317#define TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX		BIT(2)
 318#define TRF7970A_SPECIAL_FCN_REG1_SP_DIR_MODE		BIT(3)
 319#define TRF7970A_SPECIAL_FCN_REG1_NEXT_SLOT_37US	BIT(4)
 320#define TRF7970A_SPECIAL_FCN_REG1_PAR43			BIT(5)
 321
 322#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_124	(0x0 << 2)
 323#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_120	(0x1 << 2)
 324#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_112	(0x2 << 2)
 325#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96	(0x3 << 2)
 326#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_4	0x0
 327#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_8	0x1
 328#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_16	0x2
 329#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32	0x3
 330
 331#define TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(v)	((v) & 0x07)
 332#define TRF7970A_NFC_LOW_FIELD_LEVEL_CLEX_DIS	BIT(7)
 333
 334#define TRF7970A_NFC_TARGET_LEVEL_RFDET(v)	((v) & 0x07)
 335#define TRF7970A_NFC_TARGET_LEVEL_HI_RF		BIT(3)
 336#define TRF7970A_NFC_TARGET_LEVEL_SDD_EN	BIT(5)
 337#define TRF7970A_NFC_TARGET_LEVEL_LD_S_4BYTES	(0x0 << 6)
 338#define TRF7970A_NFC_TARGET_LEVEL_LD_S_7BYTES	(0x1 << 6)
 339#define TRF7970A_NFC_TARGET_LEVEL_LD_S_10BYTES	(0x2 << 6)
 340
 341#define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106		BIT(0)
 342#define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212		BIT(1)
 343#define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424		(BIT(0) | BIT(1))
 344#define TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B	BIT(2)
 345#define TRF79070A_NFC_TARGET_PROTOCOL_PAS_106		BIT(3)
 346#define TRF79070A_NFC_TARGET_PROTOCOL_FELICA		BIT(4)
 347#define TRF79070A_NFC_TARGET_PROTOCOL_RF_L		BIT(6)
 348#define TRF79070A_NFC_TARGET_PROTOCOL_RF_H		BIT(7)
 349
 350#define TRF79070A_NFC_TARGET_PROTOCOL_106A		\
 351	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
 352	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
 353	  TRF79070A_NFC_TARGET_PROTOCOL_PAS_106 |	\
 354	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
 355
 356#define TRF79070A_NFC_TARGET_PROTOCOL_106B		\
 357	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
 358	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
 359	  TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B |	\
 360	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
 361
 362#define TRF79070A_NFC_TARGET_PROTOCOL_212F		\
 363	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
 364	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
 365	  TRF79070A_NFC_TARGET_PROTOCOL_FELICA |	\
 366	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212)
 367
 368#define TRF79070A_NFC_TARGET_PROTOCOL_424F		\
 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_424)
 373
 374#define TRF7970A_FIFO_STATUS_OVERFLOW		BIT(7)
 375
 376/* NFC (ISO/IEC 14443A) Type 2 Tag commands */
 377#define NFC_T2T_CMD_READ			0x30
 378
 379/* ISO 15693 commands codes */
 380#define ISO15693_CMD_INVENTORY			0x01
 381#define ISO15693_CMD_READ_SINGLE_BLOCK		0x20
 382#define ISO15693_CMD_WRITE_SINGLE_BLOCK		0x21
 383#define ISO15693_CMD_LOCK_BLOCK			0x22
 384#define ISO15693_CMD_READ_MULTIPLE_BLOCK	0x23
 385#define ISO15693_CMD_WRITE_MULTIPLE_BLOCK	0x24
 386#define ISO15693_CMD_SELECT			0x25
 387#define ISO15693_CMD_RESET_TO_READY		0x26
 388#define ISO15693_CMD_WRITE_AFI			0x27
 389#define ISO15693_CMD_LOCK_AFI			0x28
 390#define ISO15693_CMD_WRITE_DSFID		0x29
 391#define ISO15693_CMD_LOCK_DSFID			0x2a
 392#define ISO15693_CMD_GET_SYSTEM_INFO		0x2b
 393#define ISO15693_CMD_GET_MULTIPLE_BLOCK_SECURITY_STATUS	0x2c
 394
 395/* ISO 15693 request and response flags */
 396#define ISO15693_REQ_FLAG_SUB_CARRIER		BIT(0)
 397#define ISO15693_REQ_FLAG_DATA_RATE		BIT(1)
 398#define ISO15693_REQ_FLAG_INVENTORY		BIT(2)
 399#define ISO15693_REQ_FLAG_PROTOCOL_EXT		BIT(3)
 400#define ISO15693_REQ_FLAG_SELECT		BIT(4)
 401#define ISO15693_REQ_FLAG_AFI			BIT(4)
 402#define ISO15693_REQ_FLAG_ADDRESS		BIT(5)
 403#define ISO15693_REQ_FLAG_NB_SLOTS		BIT(5)
 404#define ISO15693_REQ_FLAG_OPTION		BIT(6)
 405
 406#define ISO15693_REQ_FLAG_SPEED_MASK \
 407		(ISO15693_REQ_FLAG_SUB_CARRIER | ISO15693_REQ_FLAG_DATA_RATE)
 408
 409enum trf7970a_state {
 410	TRF7970A_ST_PWR_OFF,
 411	TRF7970A_ST_RF_OFF,
 412	TRF7970A_ST_IDLE,
 413	TRF7970A_ST_IDLE_RX_BLOCKED,
 414	TRF7970A_ST_WAIT_FOR_TX_FIFO,
 415	TRF7970A_ST_WAIT_FOR_RX_DATA,
 416	TRF7970A_ST_WAIT_FOR_RX_DATA_CONT,
 417	TRF7970A_ST_WAIT_TO_ISSUE_EOF,
 418	TRF7970A_ST_LISTENING,
 419	TRF7970A_ST_LISTENING_MD,
 420	TRF7970A_ST_MAX
 421};
 422
 423struct trf7970a {
 424	enum trf7970a_state		state;
 425	struct device			*dev;
 426	struct spi_device		*spi;
 427	struct regulator		*vin_regulator;
 428	struct regulator		*vddio_regulator;
 429	struct nfc_digital_dev		*ddev;
 430	u32				quirks;
 431	bool				is_initiator;
 432	bool				aborting;
 433	struct sk_buff			*tx_skb;
 434	struct sk_buff			*rx_skb;
 435	nfc_digital_cmd_complete_t	cb;
 436	void				*cb_arg;
 437	u8				chip_status_ctrl;
 438	u8				iso_ctrl;
 439	u8				iso_ctrl_tech;
 440	u8				modulator_sys_clk_ctrl;
 441	u8				special_fcn_reg1;
 442	u8				io_ctrl;
 443	unsigned int			guard_time;
 444	int				technology;
 445	int				framing;
 446	u8				md_rf_tech;
 447	u8				tx_cmd;
 448	bool				issue_eof;
 449	struct gpio_desc		*en_gpiod;
 450	struct gpio_desc		*en2_gpiod;
 451	struct mutex			lock;
 452	unsigned int			timeout;
 453	bool				ignore_timeout;
 454	struct delayed_work		timeout_work;
 455};
 456
 457static int trf7970a_cmd(struct trf7970a *trf, u8 opcode)
 458{
 459	u8 cmd = TRF7970A_CMD_BIT_CTRL | TRF7970A_CMD_BIT_OPCODE(opcode);
 460	int ret;
 461
 462	dev_dbg(trf->dev, "cmd: 0x%x\n", cmd);
 463
 464	ret = spi_write(trf->spi, &cmd, 1);
 465	if (ret)
 466		dev_err(trf->dev, "%s - cmd: 0x%x, ret: %d\n", __func__, cmd,
 467			ret);
 468	return ret;
 469}
 470
 471static int trf7970a_read(struct trf7970a *trf, u8 reg, u8 *val)
 472{
 473	u8 addr = TRF7970A_CMD_BIT_RW | reg;
 474	int ret;
 475
 476	ret = spi_write_then_read(trf->spi, &addr, 1, val, 1);
 477	if (ret)
 478		dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
 479			ret);
 480
 481	dev_dbg(trf->dev, "read(0x%x): 0x%x\n", addr, *val);
 482
 483	return ret;
 484}
 485
 486static int trf7970a_read_cont(struct trf7970a *trf, u8 reg, u8 *buf,
 487			      size_t len)
 488{
 489	u8 addr = reg | TRF7970A_CMD_BIT_RW | TRF7970A_CMD_BIT_CONTINUOUS;
 490	struct spi_transfer t[2];
 491	struct spi_message m;
 492	int ret;
 493
 494	dev_dbg(trf->dev, "read_cont(0x%x, %zd)\n", addr, len);
 495
 496	spi_message_init(&m);
 497
 498	memset(&t, 0, sizeof(t));
 499
 500	t[0].tx_buf = &addr;
 501	t[0].len = sizeof(addr);
 502	spi_message_add_tail(&t[0], &m);
 503
 504	t[1].rx_buf = buf;
 505	t[1].len = len;
 506	spi_message_add_tail(&t[1], &m);
 507
 508	ret = spi_sync(trf->spi, &m);
 509	if (ret)
 510		dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
 511			ret);
 512	return ret;
 513}
 514
 515static int trf7970a_write(struct trf7970a *trf, u8 reg, u8 val)
 516{
 517	u8 buf[2] = { reg, val };
 518	int ret;
 519
 520	dev_dbg(trf->dev, "write(0x%x): 0x%x\n", reg, val);
 521
 522	ret = spi_write(trf->spi, buf, 2);
 523	if (ret)
 524		dev_err(trf->dev, "%s - write: 0x%x 0x%x, ret: %d\n", __func__,
 525			buf[0], buf[1], ret);
 526
 527	return ret;
 528}
 529
 530static int trf7970a_read_irqstatus(struct trf7970a *trf, u8 *status)
 531{
 532	int ret;
 533	u8 buf[2];
 534	u8 addr;
 535
 536	addr = TRF7970A_IRQ_STATUS | TRF7970A_CMD_BIT_RW;
 537
 538	if (trf->quirks & TRF7970A_QUIRK_IRQ_STATUS_READ) {
 539		addr |= TRF7970A_CMD_BIT_CONTINUOUS;
 540		ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
 541	} else {
 542		ret = spi_write_then_read(trf->spi, &addr, 1, buf, 1);
 543	}
 544
 545	if (ret)
 546		dev_err(trf->dev, "%s - irqstatus: Status read failed: %d\n",
 547			__func__, ret);
 548	else
 549		*status = buf[0];
 550
 551	return ret;
 552}
 553
 554static int trf7970a_read_target_proto(struct trf7970a *trf, u8 *target_proto)
 555{
 556	int ret;
 557	u8 buf[2];
 558	u8 addr;
 559
 560	addr = TRF79070A_NFC_TARGET_PROTOCOL | TRF7970A_CMD_BIT_RW |
 561	       TRF7970A_CMD_BIT_CONTINUOUS;
 562
 563	ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
 564	if (ret)
 565		dev_err(trf->dev, "%s - target_proto: Read failed: %d\n",
 566			__func__, ret);
 567	else
 568		*target_proto = buf[0];
 569
 570	return ret;
 571}
 572
 573static int trf7970a_mode_detect(struct trf7970a *trf, u8 *rf_tech)
 574{
 575	int ret;
 576	u8 target_proto, tech;
 577
 578	ret = trf7970a_read_target_proto(trf, &target_proto);
 579	if (ret)
 580		return ret;
 581
 582	switch (target_proto) {
 583	case TRF79070A_NFC_TARGET_PROTOCOL_106A:
 584		tech = NFC_DIGITAL_RF_TECH_106A;
 585		break;
 586	case TRF79070A_NFC_TARGET_PROTOCOL_106B:
 587		tech = NFC_DIGITAL_RF_TECH_106B;
 588		break;
 589	case TRF79070A_NFC_TARGET_PROTOCOL_212F:
 590		tech = NFC_DIGITAL_RF_TECH_212F;
 591		break;
 592	case TRF79070A_NFC_TARGET_PROTOCOL_424F:
 593		tech = NFC_DIGITAL_RF_TECH_424F;
 594		break;
 595	default:
 596		dev_dbg(trf->dev, "%s - mode_detect: target_proto: 0x%x\n",
 597			__func__, target_proto);
 598		return -EIO;
 599	}
 600
 601	*rf_tech = tech;
 602
 603	return ret;
 604}
 605
 606static void trf7970a_send_upstream(struct trf7970a *trf)
 607{
 608	dev_kfree_skb_any(trf->tx_skb);
 609	trf->tx_skb = NULL;
 610
 611	if (trf->rx_skb && !IS_ERR(trf->rx_skb) && !trf->aborting)
 612		print_hex_dump_debug("trf7970a rx data: ", DUMP_PREFIX_NONE,
 613				     16, 1, trf->rx_skb->data, trf->rx_skb->len,
 614				     false);
 615
 616	trf->state = TRF7970A_ST_IDLE;
 617
 618	if (trf->aborting) {
 619		dev_dbg(trf->dev, "Abort process complete\n");
 620
 621		if (!IS_ERR(trf->rx_skb)) {
 622			kfree_skb(trf->rx_skb);
 623			trf->rx_skb = ERR_PTR(-ECANCELED);
 624		}
 625
 626		trf->aborting = false;
 627	}
 628
 629	trf->cb(trf->ddev, trf->cb_arg, trf->rx_skb);
 630
 631	trf->rx_skb = NULL;
 632}
 633
 634static void trf7970a_send_err_upstream(struct trf7970a *trf, int errno)
 635{
 636	dev_dbg(trf->dev, "Error - state: %d, errno: %d\n", trf->state, errno);
 637
 638	cancel_delayed_work(&trf->timeout_work);
 639
 640	kfree_skb(trf->rx_skb);
 641	trf->rx_skb = ERR_PTR(errno);
 642
 643	trf7970a_send_upstream(trf);
 644}
 645
 646static int trf7970a_transmit(struct trf7970a *trf, struct sk_buff *skb,
 647			     unsigned int len, const u8 *prefix,
 648			     unsigned int prefix_len)
 649{
 650	struct spi_transfer t[2];
 651	struct spi_message m;
 652	unsigned int timeout;
 653	int ret;
 654
 655	print_hex_dump_debug("trf7970a tx data: ", DUMP_PREFIX_NONE,
 656			     16, 1, skb->data, len, false);
 657
 658	spi_message_init(&m);
 659
 660	memset(&t, 0, sizeof(t));
 661
 662	t[0].tx_buf = prefix;
 663	t[0].len = prefix_len;
 664	spi_message_add_tail(&t[0], &m);
 665
 666	t[1].tx_buf = skb->data;
 667	t[1].len = len;
 668	spi_message_add_tail(&t[1], &m);
 669
 670	ret = spi_sync(trf->spi, &m);
 671	if (ret) {
 672		dev_err(trf->dev, "%s - Can't send tx data: %d\n", __func__,
 673			ret);
 674		return ret;
 675	}
 676
 677	skb_pull(skb, len);
 678
 679	if (skb->len > 0) {
 680		trf->state = TRF7970A_ST_WAIT_FOR_TX_FIFO;
 681		timeout = TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT;
 682	} else {
 683		if (trf->issue_eof) {
 684			trf->state = TRF7970A_ST_WAIT_TO_ISSUE_EOF;
 685			timeout = TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF;
 686		} else {
 687			trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
 688
 689			if (!trf->timeout)
 690				timeout = TRF7970A_WAIT_FOR_TX_IRQ;
 691			else
 692				timeout = trf->timeout;
 693		}
 694	}
 695
 696	dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n", timeout,
 697		trf->state);
 698
 699	schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
 700
 701	return 0;
 702}
 703
 704static void trf7970a_fill_fifo(struct trf7970a *trf)
 705{
 706	struct sk_buff *skb = trf->tx_skb;
 707	unsigned int len;
 708	int ret;
 709	u8 fifo_bytes;
 710	u8 prefix;
 711
 712	ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
 713	if (ret) {
 714		trf7970a_send_err_upstream(trf, ret);
 715		return;
 716	}
 717
 718	dev_dbg(trf->dev, "Filling FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
 719
 720	fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 721
 722	/* Calculate how much more data can be written to the fifo */
 723	len = TRF7970A_FIFO_SIZE - fifo_bytes;
 724	if (!len) {
 725		schedule_delayed_work(&trf->timeout_work,
 726			msecs_to_jiffies(TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT));
 727		return;
 728	}
 729
 730	len = min(skb->len, len);
 731
 732	prefix = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_FIFO_IO_REGISTER;
 733
 734	ret = trf7970a_transmit(trf, skb, len, &prefix, sizeof(prefix));
 735	if (ret)
 736		trf7970a_send_err_upstream(trf, ret);
 737}
 738
 739static void trf7970a_drain_fifo(struct trf7970a *trf, u8 status)
 740{
 741	struct sk_buff *skb = trf->rx_skb;
 742	int ret;
 743	u8 fifo_bytes;
 744
 745	if (status & TRF7970A_IRQ_STATUS_ERROR) {
 746		trf7970a_send_err_upstream(trf, -EIO);
 747		return;
 748	}
 749
 750	ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
 751	if (ret) {
 752		trf7970a_send_err_upstream(trf, ret);
 753		return;
 754	}
 755
 756	dev_dbg(trf->dev, "Draining FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
 757
 758	fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 759
 760	if (!fifo_bytes)
 761		goto no_rx_data;
 762
 763	if (fifo_bytes > skb_tailroom(skb)) {
 764		skb = skb_copy_expand(skb, skb_headroom(skb),
 765				      max_t(int, fifo_bytes,
 766					    TRF7970A_RX_SKB_ALLOC_SIZE),
 767				      GFP_KERNEL);
 768		if (!skb) {
 769			trf7970a_send_err_upstream(trf, -ENOMEM);
 770			return;
 771		}
 772
 773		kfree_skb(trf->rx_skb);
 774		trf->rx_skb = skb;
 775	}
 776
 777	ret = trf7970a_read_cont(trf, TRF7970A_FIFO_IO_REGISTER,
 778				 skb_put(skb, fifo_bytes), fifo_bytes);
 779	if (ret) {
 780		trf7970a_send_err_upstream(trf, ret);
 781		return;
 782	}
 783
 784	/* If received Type 2 ACK/NACK, shift right 4 bits and pass up */
 785	if ((trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T) && (skb->len == 1) &&
 786	    (trf->special_fcn_reg1 == TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX)) {
 787		skb->data[0] >>= 4;
 788		status = TRF7970A_IRQ_STATUS_SRX;
 789	} else {
 790		trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA_CONT;
 791
 792		ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
 793		if (ret) {
 794			trf7970a_send_err_upstream(trf, ret);
 795			return;
 796		}
 797
 798		fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 799
 800		/* If there are bytes in the FIFO, set status to '0' so
 801		 * the if stmt below doesn't fire and the driver will wait
 802		 * for the trf7970a to generate another RX interrupt.
 803		 */
 804		if (fifo_bytes)
 805			status = 0;
 806	}
 807
 808no_rx_data:
 809	if (status == TRF7970A_IRQ_STATUS_SRX) {	/* Receive complete */
 810		trf7970a_send_upstream(trf);
 811		return;
 812	}
 813
 814	dev_dbg(trf->dev, "Setting timeout for %d ms\n",
 815		TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT);
 816
 817	schedule_delayed_work(&trf->timeout_work,
 818			   msecs_to_jiffies(TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT));
 819}
 820
 821static irqreturn_t trf7970a_irq(int irq, void *dev_id)
 822{
 823	struct trf7970a *trf = dev_id;
 824	int ret;
 825	u8 status, fifo_bytes, iso_ctrl;
 826
 827	mutex_lock(&trf->lock);
 828
 829	if (trf->state == TRF7970A_ST_RF_OFF) {
 830		mutex_unlock(&trf->lock);
 831		return IRQ_NONE;
 832	}
 833
 834	ret = trf7970a_read_irqstatus(trf, &status);
 835	if (ret) {
 836		mutex_unlock(&trf->lock);
 837		return IRQ_NONE;
 838	}
 839
 840	dev_dbg(trf->dev, "IRQ - state: %d, status: 0x%x\n", trf->state,
 841		status);
 842
 843	if (!status) {
 844		mutex_unlock(&trf->lock);
 845		return IRQ_NONE;
 846	}
 847
 848	switch (trf->state) {
 849	case TRF7970A_ST_IDLE:
 850	case TRF7970A_ST_IDLE_RX_BLOCKED:
 851		/* If initiator and getting interrupts caused by RF noise,
 852		 * turn off the receiver to avoid unnecessary interrupts.
 853		 * It will be turned back on in trf7970a_send_cmd() when
 854		 * the next command is issued.
 855		 */
 856		if (trf->is_initiator && (status & TRF7970A_IRQ_STATUS_ERROR)) {
 857			trf7970a_cmd(trf, TRF7970A_CMD_BLOCK_RX);
 858			trf->state = TRF7970A_ST_IDLE_RX_BLOCKED;
 859		}
 860
 861		trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 862		break;
 863	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
 864		if (status & TRF7970A_IRQ_STATUS_TX) {
 865			trf->ignore_timeout =
 866			    !cancel_delayed_work(&trf->timeout_work);
 867			trf7970a_fill_fifo(trf);
 868		} else {
 869			trf7970a_send_err_upstream(trf, -EIO);
 870		}
 871		break;
 872	case TRF7970A_ST_WAIT_FOR_RX_DATA:
 873	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
 874		if (status & TRF7970A_IRQ_STATUS_SRX) {
 875			trf->ignore_timeout =
 876			    !cancel_delayed_work(&trf->timeout_work);
 877			trf7970a_drain_fifo(trf, status);
 878		} else if (status & TRF7970A_IRQ_STATUS_FIFO) {
 879			ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS,
 880					    &fifo_bytes);
 881
 882			fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 883
 884			if (ret)
 885				trf7970a_send_err_upstream(trf, ret);
 886			else if (!fifo_bytes)
 887				trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 888		} else if ((status == TRF7970A_IRQ_STATUS_TX) ||
 889			   (!trf->is_initiator &&
 890			    (status == (TRF7970A_IRQ_STATUS_TX |
 891					TRF7970A_IRQ_STATUS_NFC_RF)))) {
 892			trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 893
 894			if (!trf->timeout) {
 895				trf->ignore_timeout =
 896				    !cancel_delayed_work(&trf->timeout_work);
 897				trf->rx_skb = ERR_PTR(0);
 898				trf7970a_send_upstream(trf);
 899				break;
 900			}
 901
 902			if (trf->is_initiator)
 903				break;
 904
 905			iso_ctrl = trf->iso_ctrl;
 906
 907			switch (trf->framing) {
 908			case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
 909				trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
 910				iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
 911				trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
 912				break;
 913			case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
 914				trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
 915				iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
 916				trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
 917				break;
 918			case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
 919				ret = trf7970a_write(trf,
 920					 TRF7970A_SPECIAL_FCN_REG1,
 921					 TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL);
 922				if (ret)
 923					goto err_unlock_exit;
 924
 925				trf->special_fcn_reg1 =
 926				    TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL;
 927				break;
 928			default:
 929				break;
 930			}
 931
 932			if (iso_ctrl != trf->iso_ctrl) {
 933				ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
 934						     iso_ctrl);
 935				if (ret)
 936					goto err_unlock_exit;
 937
 938				trf->iso_ctrl = iso_ctrl;
 939			}
 940		} else {
 941			trf7970a_send_err_upstream(trf, -EIO);
 942		}
 943		break;
 944	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
 945		if (status != TRF7970A_IRQ_STATUS_TX)
 946			trf7970a_send_err_upstream(trf, -EIO);
 947		break;
 948	case TRF7970A_ST_LISTENING:
 949		if (status & TRF7970A_IRQ_STATUS_SRX) {
 950			trf->ignore_timeout =
 951			    !cancel_delayed_work(&trf->timeout_work);
 952			trf7970a_drain_fifo(trf, status);
 953		} else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
 954			trf7970a_send_err_upstream(trf, -EIO);
 955		}
 956		break;
 957	case TRF7970A_ST_LISTENING_MD:
 958		if (status & TRF7970A_IRQ_STATUS_SRX) {
 959			trf->ignore_timeout =
 960			    !cancel_delayed_work(&trf->timeout_work);
 961
 962			ret = trf7970a_mode_detect(trf, &trf->md_rf_tech);
 963			if (ret) {
 964				trf7970a_send_err_upstream(trf, ret);
 965			} else {
 966				trf->state = TRF7970A_ST_LISTENING;
 967				trf7970a_drain_fifo(trf, status);
 968			}
 969		} else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
 970			trf7970a_send_err_upstream(trf, -EIO);
 971		}
 972		break;
 973	default:
 974		dev_err(trf->dev, "%s - Driver in invalid state: %d\n",
 975			__func__, trf->state);
 976	}
 977
 978err_unlock_exit:
 979	mutex_unlock(&trf->lock);
 980	return IRQ_HANDLED;
 981}
 982
 983static void trf7970a_issue_eof(struct trf7970a *trf)
 984{
 985	int ret;
 986
 987	dev_dbg(trf->dev, "Issuing EOF\n");
 988
 989	ret = trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 990	if (ret)
 991		trf7970a_send_err_upstream(trf, ret);
 992
 993	ret = trf7970a_cmd(trf, TRF7970A_CMD_EOF);
 994	if (ret)
 995		trf7970a_send_err_upstream(trf, ret);
 996
 997	trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
 998
 999	dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n",
1000		trf->timeout, trf->state);
1001
1002	schedule_delayed_work(&trf->timeout_work,
1003			      msecs_to_jiffies(trf->timeout));
1004}
1005
1006static void trf7970a_timeout_work_handler(struct work_struct *work)
1007{
1008	struct trf7970a *trf = container_of(work, struct trf7970a,
1009					    timeout_work.work);
1010
1011	dev_dbg(trf->dev, "Timeout - state: %d, ignore_timeout: %d\n",
1012		trf->state, trf->ignore_timeout);
1013
1014	mutex_lock(&trf->lock);
1015
1016	if (trf->ignore_timeout)
1017		trf->ignore_timeout = false;
1018	else if (trf->state == TRF7970A_ST_WAIT_FOR_RX_DATA_CONT)
1019		trf7970a_drain_fifo(trf, TRF7970A_IRQ_STATUS_SRX);
1020	else if (trf->state == TRF7970A_ST_WAIT_TO_ISSUE_EOF)
1021		trf7970a_issue_eof(trf);
1022	else
1023		trf7970a_send_err_upstream(trf, -ETIMEDOUT);
1024
1025	mutex_unlock(&trf->lock);
1026}
1027
1028static int trf7970a_init(struct trf7970a *trf)
1029{
1030	int ret;
1031
1032	dev_dbg(trf->dev, "Initializing device - state: %d\n", trf->state);
1033
1034	ret = trf7970a_cmd(trf, TRF7970A_CMD_SOFT_INIT);
1035	if (ret)
1036		goto err_out;
1037
1038	ret = trf7970a_cmd(trf, TRF7970A_CMD_IDLE);
1039	if (ret)
1040		goto err_out;
1041
1042	ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1043			     trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1044	if (ret)
1045		goto err_out;
1046
1047	ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1048	if (ret)
1049		goto err_out;
1050
1051	usleep_range(1000, 2000);
1052
1053	trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1054
1055	ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1056			     trf->modulator_sys_clk_ctrl);
1057	if (ret)
1058		goto err_out;
1059
1060	ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS,
1061			     TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 |
1062			     TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32);
1063	if (ret)
1064		goto err_out;
1065
1066	ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1, 0);
1067	if (ret)
1068		goto err_out;
1069
1070	trf->special_fcn_reg1 = 0;
1071
1072	trf->iso_ctrl = 0xff;
1073	return 0;
1074
1075err_out:
1076	dev_dbg(trf->dev, "Couldn't init device: %d\n", ret);
1077	return ret;
1078}
1079
1080static void trf7970a_switch_rf_off(struct trf7970a *trf)
1081{
1082	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1083	    (trf->state == TRF7970A_ST_RF_OFF))
1084		return;
1085
1086	dev_dbg(trf->dev, "Switching rf off\n");
1087
1088	trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1089
1090	trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, trf->chip_status_ctrl);
1091
1092	trf->aborting = false;
1093	trf->state = TRF7970A_ST_RF_OFF;
1094
1095	pm_runtime_mark_last_busy(trf->dev);
1096	pm_runtime_put_autosuspend(trf->dev);
1097}
1098
1099static int trf7970a_switch_rf_on(struct trf7970a *trf)
1100{
1101	int ret;
1102
1103	dev_dbg(trf->dev, "Switching rf on\n");
1104
1105	pm_runtime_get_sync(trf->dev);
1106
1107	if (trf->state != TRF7970A_ST_RF_OFF) {	/* Power on, RF off */
1108		dev_err(trf->dev, "%s - Incorrect state: %d\n", __func__,
1109			trf->state);
1110		return -EINVAL;
1111	}
1112
1113	ret = trf7970a_init(trf);
1114	if (ret) {
1115		dev_err(trf->dev, "%s - Can't initialize: %d\n", __func__, ret);
1116		return ret;
1117	}
1118
1119	trf->state = TRF7970A_ST_IDLE;
1120
1121	return 0;
1122}
1123
1124static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on)
1125{
1126	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1127	int ret = 0;
1128
1129	dev_dbg(trf->dev, "Switching RF - state: %d, on: %d\n", trf->state, on);
1130
1131	mutex_lock(&trf->lock);
1132
1133	if (on) {
1134		switch (trf->state) {
1135		case TRF7970A_ST_PWR_OFF:
1136		case TRF7970A_ST_RF_OFF:
1137			ret = trf7970a_switch_rf_on(trf);
1138			break;
1139		case TRF7970A_ST_IDLE:
1140		case TRF7970A_ST_IDLE_RX_BLOCKED:
1141			break;
1142		default:
1143			dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1144				__func__, trf->state, on);
1145			trf7970a_switch_rf_off(trf);
1146			ret = -EINVAL;
1147		}
1148	} else {
1149		switch (trf->state) {
1150		case TRF7970A_ST_PWR_OFF:
1151		case TRF7970A_ST_RF_OFF:
1152			break;
1153		default:
1154			dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1155				__func__, trf->state, on);
1156			ret = -EINVAL;
1157			fallthrough;
1158		case TRF7970A_ST_IDLE:
1159		case TRF7970A_ST_IDLE_RX_BLOCKED:
1160		case TRF7970A_ST_WAIT_FOR_RX_DATA:
1161		case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1162			trf7970a_switch_rf_off(trf);
1163		}
1164	}
1165
1166	mutex_unlock(&trf->lock);
1167	return ret;
1168}
1169
1170static int trf7970a_in_config_rf_tech(struct trf7970a *trf, int tech)
1171{
1172	int ret = 0;
1173
1174	dev_dbg(trf->dev, "rf technology: %d\n", tech);
1175
1176	switch (tech) {
1177	case NFC_DIGITAL_RF_TECH_106A:
1178		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443A_106;
1179		trf->modulator_sys_clk_ctrl =
1180		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1181		    TRF7970A_MODULATOR_DEPTH_OOK;
1182		trf->guard_time = TRF7970A_GUARD_TIME_NFCA;
1183		break;
1184	case NFC_DIGITAL_RF_TECH_106B:
1185		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443B_106;
1186		trf->modulator_sys_clk_ctrl =
1187		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1188		    TRF7970A_MODULATOR_DEPTH_ASK10;
1189		trf->guard_time = TRF7970A_GUARD_TIME_NFCB;
1190		break;
1191	case NFC_DIGITAL_RF_TECH_212F:
1192		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_212;
1193		trf->modulator_sys_clk_ctrl =
1194		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1195		    TRF7970A_MODULATOR_DEPTH_ASK10;
1196		trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1197		break;
1198	case NFC_DIGITAL_RF_TECH_424F:
1199		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_424;
1200		trf->modulator_sys_clk_ctrl =
1201		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1202		    TRF7970A_MODULATOR_DEPTH_ASK10;
1203		trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1204		break;
1205	case NFC_DIGITAL_RF_TECH_ISO15693:
1206		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1207		trf->modulator_sys_clk_ctrl =
1208		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1209		    TRF7970A_MODULATOR_DEPTH_OOK;
1210		trf->guard_time = TRF7970A_GUARD_TIME_15693;
1211		break;
1212	default:
1213		dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1214		return -EINVAL;
1215	}
1216
1217	trf->technology = tech;
1218
1219	/* If in initiator mode and not changing the RF tech due to a
1220	 * PSL sequence (indicated by 'trf->iso_ctrl == 0xff' from
1221	 * trf7970a_init()), clear the NFC Target Detection Level register
1222	 * due to erratum.
1223	 */
1224	if (trf->iso_ctrl == 0xff)
1225		ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1226
1227	return ret;
1228}
1229
1230static int trf7970a_is_rf_field(struct trf7970a *trf, bool *is_rf_field)
1231{
1232	int ret;
1233	u8 rssi;
1234
1235	ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1236			     trf->chip_status_ctrl |
1237			     TRF7970A_CHIP_STATUS_REC_ON);
1238	if (ret)
1239		return ret;
1240
1241	ret = trf7970a_cmd(trf, TRF7970A_CMD_TEST_EXT_RF);
1242	if (ret)
1243		return ret;
1244
1245	usleep_range(50, 60);
1246
1247	ret = trf7970a_read(trf, TRF7970A_RSSI_OSC_STATUS, &rssi);
1248	if (ret)
1249		return ret;
1250
1251	ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1252			     trf->chip_status_ctrl);
1253	if (ret)
1254		return ret;
1255
1256	if (rssi & TRF7970A_RSSI_OSC_STATUS_RSSI_MASK)
1257		*is_rf_field = true;
1258	else
1259		*is_rf_field = false;
1260
1261	return 0;
1262}
1263
1264static int trf7970a_in_config_framing(struct trf7970a *trf, int framing)
1265{
1266	u8 iso_ctrl = trf->iso_ctrl_tech;
1267	bool is_rf_field = false;
1268	int ret;
1269
1270	dev_dbg(trf->dev, "framing: %d\n", framing);
1271
1272	switch (framing) {
1273	case NFC_DIGITAL_FRAMING_NFCA_SHORT:
1274	case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1275		trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1276		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1277		break;
1278	case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1279	case NFC_DIGITAL_FRAMING_NFCA_T4T:
1280	case NFC_DIGITAL_FRAMING_NFCB:
1281	case NFC_DIGITAL_FRAMING_NFCB_T4T:
1282	case NFC_DIGITAL_FRAMING_NFCF:
1283	case NFC_DIGITAL_FRAMING_NFCF_T3T:
1284	case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY:
1285	case NFC_DIGITAL_FRAMING_ISO15693_T5T:
1286	case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1287	case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1288		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1289		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1290		break;
1291	case NFC_DIGITAL_FRAMING_NFCA_T2T:
1292		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1293		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1294		break;
1295	default:
1296		dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1297		return -EINVAL;
1298	}
1299
1300	trf->framing = framing;
1301
1302	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1303		ret = trf7970a_is_rf_field(trf, &is_rf_field);
1304		if (ret)
1305			return ret;
1306
1307		if (is_rf_field)
1308			return -EBUSY;
1309	}
1310
1311	if (iso_ctrl != trf->iso_ctrl) {
1312		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1313		if (ret)
1314			return ret;
1315
1316		trf->iso_ctrl = iso_ctrl;
1317
1318		ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1319				     trf->modulator_sys_clk_ctrl);
1320		if (ret)
1321			return ret;
1322	}
1323
1324	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1325		ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1326				     trf->chip_status_ctrl |
1327				     TRF7970A_CHIP_STATUS_RF_ON);
1328		if (ret)
1329			return ret;
1330
1331		trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1332
1333		usleep_range(trf->guard_time, trf->guard_time + 1000);
1334	}
1335
1336	return 0;
1337}
1338
1339static int trf7970a_in_configure_hw(struct nfc_digital_dev *ddev, int type,
1340				    int param)
1341{
1342	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1343	int ret;
1344
1345	dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1346
1347	mutex_lock(&trf->lock);
1348
1349	trf->is_initiator = true;
1350
1351	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1352	    (trf->state == TRF7970A_ST_RF_OFF)) {
1353		ret = trf7970a_switch_rf_on(trf);
1354		if (ret)
1355			goto err_unlock;
1356	}
1357
1358	switch (type) {
1359	case NFC_DIGITAL_CONFIG_RF_TECH:
1360		ret = trf7970a_in_config_rf_tech(trf, param);
1361		break;
1362	case NFC_DIGITAL_CONFIG_FRAMING:
1363		ret = trf7970a_in_config_framing(trf, param);
1364		break;
1365	default:
1366		dev_dbg(trf->dev, "Unknown type: %d\n", type);
1367		ret = -EINVAL;
1368	}
1369
1370err_unlock:
1371	mutex_unlock(&trf->lock);
1372	return ret;
1373}
1374
1375static int trf7970a_is_iso15693_write_or_lock(u8 cmd)
1376{
1377	switch (cmd) {
1378	case ISO15693_CMD_WRITE_SINGLE_BLOCK:
1379	case ISO15693_CMD_LOCK_BLOCK:
1380	case ISO15693_CMD_WRITE_MULTIPLE_BLOCK:
1381	case ISO15693_CMD_WRITE_AFI:
1382	case ISO15693_CMD_LOCK_AFI:
1383	case ISO15693_CMD_WRITE_DSFID:
1384	case ISO15693_CMD_LOCK_DSFID:
1385		return 1;
1386	default:
1387		return 0;
1388	}
1389}
1390
1391static int trf7970a_per_cmd_config(struct trf7970a *trf,
1392				   const struct sk_buff *skb)
1393{
1394	const u8 *req = skb->data;
1395	u8 special_fcn_reg1, iso_ctrl;
1396	int ret;
1397
1398	trf->issue_eof = false;
1399
1400	/* When issuing Type 2 read command, make sure the '4_bit_RX' bit in
1401	 * special functions register 1 is cleared; otherwise, its a write or
1402	 * sector select command and '4_bit_RX' must be set.
1403	 *
1404	 * When issuing an ISO 15693 command, inspect the flags byte to see
1405	 * what speed to use.  Also, remember if the OPTION flag is set on
1406	 * a Type 5 write or lock command so the driver will know that it
1407	 * has to send an EOF in order to get a response.
1408	 */
1409	if ((trf->technology == NFC_DIGITAL_RF_TECH_106A) &&
1410	    (trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T)) {
1411		if (req[0] == NFC_T2T_CMD_READ)
1412			special_fcn_reg1 = 0;
1413		else
1414			special_fcn_reg1 = TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX;
1415
1416		if (special_fcn_reg1 != trf->special_fcn_reg1) {
1417			ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1,
1418					     special_fcn_reg1);
1419			if (ret)
1420				return ret;
1421
1422			trf->special_fcn_reg1 = special_fcn_reg1;
1423		}
1424	} else if (trf->technology == NFC_DIGITAL_RF_TECH_ISO15693) {
1425		iso_ctrl = trf->iso_ctrl & ~TRF7970A_ISO_CTRL_RFID_SPEED_MASK;
1426
1427		switch (req[0] & ISO15693_REQ_FLAG_SPEED_MASK) {
1428		case 0x00:
1429			iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_662;
1430			break;
1431		case ISO15693_REQ_FLAG_SUB_CARRIER:
1432			iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a;
1433			break;
1434		case ISO15693_REQ_FLAG_DATA_RATE:
1435			iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1436			break;
1437		case (ISO15693_REQ_FLAG_SUB_CARRIER |
1438		      ISO15693_REQ_FLAG_DATA_RATE):
1439			iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669;
1440			break;
1441		}
1442
1443		if (iso_ctrl != trf->iso_ctrl) {
1444			ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1445			if (ret)
1446				return ret;
1447
1448			trf->iso_ctrl = iso_ctrl;
1449		}
1450
1451		if ((trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) &&
1452		    trf7970a_is_iso15693_write_or_lock(req[1]) &&
1453		    (req[0] & ISO15693_REQ_FLAG_OPTION))
1454			trf->issue_eof = true;
1455	}
1456
1457	return 0;
1458}
1459
1460static int trf7970a_send_cmd(struct nfc_digital_dev *ddev,
1461			     struct sk_buff *skb, u16 timeout,
1462			     nfc_digital_cmd_complete_t cb, void *arg)
1463{
1464	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1465	u8 prefix[5];
1466	unsigned int len;
1467	int ret;
1468	u8 status;
1469
1470	dev_dbg(trf->dev, "New request - state: %d, timeout: %d ms, len: %d\n",
1471		trf->state, timeout, skb->len);
1472
1473	if (skb->len > TRF7970A_TX_MAX)
1474		return -EINVAL;
1475
1476	mutex_lock(&trf->lock);
1477
1478	if ((trf->state != TRF7970A_ST_IDLE) &&
1479	    (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1480		dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1481			trf->state);
1482		ret = -EIO;
1483		goto out_err;
1484	}
1485
1486	if (trf->aborting) {
1487		dev_dbg(trf->dev, "Abort process complete\n");
1488		trf->aborting = false;
1489		ret = -ECANCELED;
1490		goto out_err;
1491	}
1492
1493	if (timeout) {
1494		trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1495						 GFP_KERNEL);
1496		if (!trf->rx_skb) {
1497			dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1498			ret = -ENOMEM;
1499			goto out_err;
1500		}
1501	}
1502
1503	if (trf->state == TRF7970A_ST_IDLE_RX_BLOCKED) {
1504		ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1505		if (ret)
1506			goto out_err;
1507
1508		trf->state = TRF7970A_ST_IDLE;
1509	}
1510
1511	if (trf->is_initiator) {
1512		ret = trf7970a_per_cmd_config(trf, skb);
1513		if (ret)
1514			goto out_err;
1515	}
1516
1517	trf->ddev = ddev;
1518	trf->tx_skb = skb;
1519	trf->cb = cb;
1520	trf->cb_arg = arg;
1521	trf->timeout = timeout;
1522	trf->ignore_timeout = false;
1523
1524	len = skb->len;
1525
1526	/* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
1527	 * on what the current framing is, the address of the TX length byte 1
1528	 * register (0x1d), and the 2 byte length of the data to be transmitted.
1529	 * That totals 5 bytes.
1530	 */
1531	prefix[0] = TRF7970A_CMD_BIT_CTRL |
1532	    TRF7970A_CMD_BIT_OPCODE(TRF7970A_CMD_FIFO_RESET);
1533	prefix[1] = TRF7970A_CMD_BIT_CTRL |
1534	    TRF7970A_CMD_BIT_OPCODE(trf->tx_cmd);
1535	prefix[2] = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_TX_LENGTH_BYTE1;
1536
1537	if (trf->framing == NFC_DIGITAL_FRAMING_NFCA_SHORT) {
1538		prefix[3] = 0x00;
1539		prefix[4] = 0x0f;	/* 7 bits */
1540	} else {
1541		prefix[3] = (len & 0xf00) >> 4;
1542		prefix[3] |= ((len & 0xf0) >> 4);
1543		prefix[4] = ((len & 0x0f) << 4);
1544	}
1545
1546	len = min_t(int, skb->len, TRF7970A_FIFO_SIZE);
1547
1548	/* Clear possible spurious interrupt */
1549	ret = trf7970a_read_irqstatus(trf, &status);
1550	if (ret)
1551		goto out_err;
1552
1553	ret = trf7970a_transmit(trf, skb, len, prefix, sizeof(prefix));
1554	if (ret) {
1555		kfree_skb(trf->rx_skb);
1556		trf->rx_skb = NULL;
1557	}
1558
1559out_err:
1560	mutex_unlock(&trf->lock);
1561	return ret;
1562}
1563
1564static int trf7970a_tg_config_rf_tech(struct trf7970a *trf, int tech)
1565{
1566	int ret = 0;
1567
1568	dev_dbg(trf->dev, "rf technology: %d\n", tech);
1569
1570	switch (tech) {
1571	case NFC_DIGITAL_RF_TECH_106A:
1572		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1573		    TRF7970A_ISO_CTRL_NFC_CE | TRF7970A_ISO_CTRL_NFC_CE_14443A;
1574		trf->modulator_sys_clk_ctrl =
1575		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1576		    TRF7970A_MODULATOR_DEPTH_OOK;
1577		break;
1578	case NFC_DIGITAL_RF_TECH_212F:
1579		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1580		    TRF7970A_ISO_CTRL_NFC_NFCF_212;
1581		trf->modulator_sys_clk_ctrl =
1582		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1583		    TRF7970A_MODULATOR_DEPTH_ASK10;
1584		break;
1585	case NFC_DIGITAL_RF_TECH_424F:
1586		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1587		    TRF7970A_ISO_CTRL_NFC_NFCF_424;
1588		trf->modulator_sys_clk_ctrl =
1589		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1590		    TRF7970A_MODULATOR_DEPTH_ASK10;
1591		break;
1592	default:
1593		dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1594		return -EINVAL;
1595	}
1596
1597	trf->technology = tech;
1598
1599	/* Normally we write the ISO_CTRL register in
1600	 * trf7970a_tg_config_framing() because the framing can change
1601	 * the value written.  However, when sending a PSL RES,
1602	 * digital_tg_send_psl_res_complete() doesn't call
1603	 * trf7970a_tg_config_framing() so we must write the register
1604	 * here.
1605	 */
1606	if ((trf->framing == NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED) &&
1607	    (trf->iso_ctrl_tech != trf->iso_ctrl)) {
1608		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
1609				     trf->iso_ctrl_tech);
1610
1611		trf->iso_ctrl = trf->iso_ctrl_tech;
1612	}
1613
1614	return ret;
1615}
1616
1617/* Since this is a target routine, several of the framing calls are
1618 * made between receiving the request and sending the response so they
1619 * should take effect until after the response is sent.  This is accomplished
1620 * by skipping the ISO_CTRL register write here and doing it in the interrupt
1621 * handler.
1622 */
1623static int trf7970a_tg_config_framing(struct trf7970a *trf, int framing)
1624{
1625	u8 iso_ctrl = trf->iso_ctrl_tech;
1626	int ret;
1627
1628	dev_dbg(trf->dev, "framing: %d\n", framing);
1629
1630	switch (framing) {
1631	case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1632		trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1633		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1634		break;
1635	case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1636	case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1637	case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
1638		/* These ones are applied in the interrupt handler */
1639		iso_ctrl = trf->iso_ctrl; /* Don't write to ISO_CTRL yet */
1640		break;
1641	case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1642		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1643		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1644		break;
1645	case NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED:
1646		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1647		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1648		break;
1649	default:
1650		dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1651		return -EINVAL;
1652	}
1653
1654	trf->framing = framing;
1655
1656	if (iso_ctrl != trf->iso_ctrl) {
1657		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1658		if (ret)
1659			return ret;
1660
1661		trf->iso_ctrl = iso_ctrl;
1662
1663		ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1664				     trf->modulator_sys_clk_ctrl);
1665		if (ret)
1666			return ret;
1667	}
1668
1669	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1670		ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1671				     trf->chip_status_ctrl |
1672				     TRF7970A_CHIP_STATUS_RF_ON);
1673		if (ret)
1674			return ret;
1675
1676		trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1677	}
1678
1679	return 0;
1680}
1681
1682static int trf7970a_tg_configure_hw(struct nfc_digital_dev *ddev, int type,
1683				    int param)
1684{
1685	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1686	int ret;
1687
1688	dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1689
1690	mutex_lock(&trf->lock);
1691
1692	trf->is_initiator = false;
1693
1694	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1695	    (trf->state == TRF7970A_ST_RF_OFF)) {
1696		ret = trf7970a_switch_rf_on(trf);
1697		if (ret)
1698			goto err_unlock;
1699	}
1700
1701	switch (type) {
1702	case NFC_DIGITAL_CONFIG_RF_TECH:
1703		ret = trf7970a_tg_config_rf_tech(trf, param);
1704		break;
1705	case NFC_DIGITAL_CONFIG_FRAMING:
1706		ret = trf7970a_tg_config_framing(trf, param);
1707		break;
1708	default:
1709		dev_dbg(trf->dev, "Unknown type: %d\n", type);
1710		ret = -EINVAL;
1711	}
1712
1713err_unlock:
1714	mutex_unlock(&trf->lock);
1715	return ret;
1716}
1717
1718static int _trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1719			       nfc_digital_cmd_complete_t cb, void *arg,
1720			       bool mode_detect)
1721{
1722	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1723	int ret;
1724
1725	mutex_lock(&trf->lock);
1726
1727	if ((trf->state != TRF7970A_ST_IDLE) &&
1728	    (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1729		dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1730			trf->state);
1731		ret = -EIO;
1732		goto out_err;
1733	}
1734
1735	if (trf->aborting) {
1736		dev_dbg(trf->dev, "Abort process complete\n");
1737		trf->aborting = false;
1738		ret = -ECANCELED;
1739		goto out_err;
1740	}
1741
1742	trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1743					 GFP_KERNEL);
1744	if (!trf->rx_skb) {
1745		dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1746		ret = -ENOMEM;
1747		goto out_err;
1748	}
1749
1750	ret = trf7970a_write(trf, TRF7970A_RX_SPECIAL_SETTINGS,
1751			     TRF7970A_RX_SPECIAL_SETTINGS_HBT |
1752			     TRF7970A_RX_SPECIAL_SETTINGS_M848 |
1753			     TRF7970A_RX_SPECIAL_SETTINGS_C424 |
1754			     TRF7970A_RX_SPECIAL_SETTINGS_C212);
1755	if (ret)
1756		goto out_err;
1757
1758	ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1759			     trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1760	if (ret)
1761		goto out_err;
1762
1763	ret = trf7970a_write(trf, TRF7970A_NFC_LOW_FIELD_LEVEL,
1764			     TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(0x3));
1765	if (ret)
1766		goto out_err;
1767
1768	ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL,
1769			     TRF7970A_NFC_TARGET_LEVEL_RFDET(0x7));
1770	if (ret)
1771		goto out_err;
1772
1773	trf->ddev = ddev;
1774	trf->cb = cb;
1775	trf->cb_arg = arg;
1776	trf->timeout = timeout;
1777	trf->ignore_timeout = false;
1778
1779	ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1780	if (ret)
1781		goto out_err;
1782
1783	trf->state = mode_detect ? TRF7970A_ST_LISTENING_MD :
1784				   TRF7970A_ST_LISTENING;
1785
1786	schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
1787
1788out_err:
1789	mutex_unlock(&trf->lock);
1790	return ret;
1791}
1792
1793static int trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1794			      nfc_digital_cmd_complete_t cb, void *arg)
1795{
1796	const struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1797
1798	dev_dbg(trf->dev, "Listen - state: %d, timeout: %d ms\n",
1799		trf->state, timeout);
1800
1801	return _trf7970a_tg_listen(ddev, timeout, cb, arg, false);
1802}
1803
1804static int trf7970a_tg_listen_md(struct nfc_digital_dev *ddev,
1805				 u16 timeout, nfc_digital_cmd_complete_t cb,
1806				 void *arg)
1807{
1808	const struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1809	int ret;
1810
1811	dev_dbg(trf->dev, "Listen MD - state: %d, timeout: %d ms\n",
1812		trf->state, timeout);
1813
1814	ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
1815				       NFC_DIGITAL_RF_TECH_106A);
1816	if (ret)
1817		return ret;
1818
1819	ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1820				       NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
1821	if (ret)
1822		return ret;
1823
1824	return _trf7970a_tg_listen(ddev, timeout, cb, arg, true);
1825}
1826
1827static int trf7970a_tg_get_rf_tech(struct nfc_digital_dev *ddev, u8 *rf_tech)
1828{
1829	const struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1830
1831	dev_dbg(trf->dev, "Get RF Tech - state: %d, rf_tech: %d\n",
1832		trf->state, trf->md_rf_tech);
1833
1834	*rf_tech = trf->md_rf_tech;
1835
1836	return 0;
1837}
1838
1839static void trf7970a_abort_cmd(struct nfc_digital_dev *ddev)
1840{
1841	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1842
1843	dev_dbg(trf->dev, "Abort process initiated\n");
1844
1845	mutex_lock(&trf->lock);
1846
1847	switch (trf->state) {
1848	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1849	case TRF7970A_ST_WAIT_FOR_RX_DATA:
1850	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1851	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1852		trf->aborting = true;
1853		break;
1854	case TRF7970A_ST_LISTENING:
1855		trf->ignore_timeout = !cancel_delayed_work(&trf->timeout_work);
1856		trf7970a_send_err_upstream(trf, -ECANCELED);
1857		dev_dbg(trf->dev, "Abort process complete\n");
1858		break;
1859	default:
1860		break;
1861	}
1862
1863	mutex_unlock(&trf->lock);
1864}
1865
1866static const struct nfc_digital_ops trf7970a_nfc_ops = {
1867	.in_configure_hw	= trf7970a_in_configure_hw,
1868	.in_send_cmd		= trf7970a_send_cmd,
1869	.tg_configure_hw	= trf7970a_tg_configure_hw,
1870	.tg_send_cmd		= trf7970a_send_cmd,
1871	.tg_listen		= trf7970a_tg_listen,
1872	.tg_listen_md		= trf7970a_tg_listen_md,
1873	.tg_get_rf_tech		= trf7970a_tg_get_rf_tech,
1874	.switch_rf		= trf7970a_switch_rf,
1875	.abort_cmd		= trf7970a_abort_cmd,
1876};
1877
1878static int trf7970a_power_up(struct trf7970a *trf)
1879{
1880	int ret;
1881
1882	dev_dbg(trf->dev, "Powering up - state: %d\n", trf->state);
1883
1884	if (trf->state != TRF7970A_ST_PWR_OFF)
1885		return 0;
1886
1887	ret = regulator_enable(trf->vin_regulator);
1888	if (ret) {
1889		dev_err(trf->dev, "%s - Can't enable VIN: %d\n", __func__, ret);
1890		return ret;
1891	}
1892
1893	usleep_range(5000, 6000);
1894
1895	if (trf->en2_gpiod &&
1896	    !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW)) {
1897		gpiod_set_value_cansleep(trf->en2_gpiod, 1);
1898		usleep_range(1000, 2000);
1899	}
1900
1901	gpiod_set_value_cansleep(trf->en_gpiod, 1);
1902
1903	usleep_range(20000, 21000);
1904
1905	trf->state = TRF7970A_ST_RF_OFF;
1906
1907	return 0;
1908}
1909
1910static int trf7970a_power_down(struct trf7970a *trf)
1911{
1912	int ret;
1913
1914	dev_dbg(trf->dev, "Powering down - state: %d\n", trf->state);
1915
1916	if (trf->state == TRF7970A_ST_PWR_OFF)
1917		return 0;
1918
1919	if (trf->state != TRF7970A_ST_RF_OFF) {
1920		dev_dbg(trf->dev, "Can't power down - not RF_OFF state (%d)\n",
1921			trf->state);
1922		return -EBUSY;
1923	}
1924
1925	gpiod_set_value_cansleep(trf->en_gpiod, 0);
1926
1927	if (trf->en2_gpiod && !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW))
1928		gpiod_set_value_cansleep(trf->en2_gpiod, 0);
1929
1930	ret = regulator_disable(trf->vin_regulator);
1931	if (ret)
1932		dev_err(trf->dev, "%s - Can't disable VIN: %d\n", __func__,
1933			ret);
1934
1935	trf->state = TRF7970A_ST_PWR_OFF;
1936
1937	return ret;
1938}
1939
1940static int trf7970a_startup(struct trf7970a *trf)
1941{
1942	int ret;
1943
1944	ret = trf7970a_power_up(trf);
1945	if (ret)
1946		return ret;
1947
1948	pm_runtime_set_active(trf->dev);
1949	pm_runtime_enable(trf->dev);
1950	pm_runtime_mark_last_busy(trf->dev);
1951
1952	return 0;
1953}
1954
1955static void trf7970a_shutdown(struct trf7970a *trf)
1956{
1957	switch (trf->state) {
1958	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1959	case TRF7970A_ST_WAIT_FOR_RX_DATA:
1960	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1961	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1962	case TRF7970A_ST_LISTENING:
1963		trf7970a_send_err_upstream(trf, -ECANCELED);
1964		fallthrough;
1965	case TRF7970A_ST_IDLE:
1966	case TRF7970A_ST_IDLE_RX_BLOCKED:
1967		trf7970a_switch_rf_off(trf);
1968		break;
1969	default:
1970		break;
1971	}
1972
1973	pm_runtime_disable(trf->dev);
1974	pm_runtime_set_suspended(trf->dev);
1975
1976	trf7970a_power_down(trf);
1977}
1978
1979static int trf7970a_get_autosuspend_delay(const struct device_node *np)
1980{
1981	int autosuspend_delay, ret;
1982
1983	ret = of_property_read_u32(np, "autosuspend-delay", &autosuspend_delay);
1984	if (ret)
1985		autosuspend_delay = TRF7970A_AUTOSUSPEND_DELAY;
1986
1987	return autosuspend_delay;
1988}
1989
1990static int trf7970a_probe(struct spi_device *spi)
1991{
1992	const struct device_node *np = spi->dev.of_node;
1993	struct trf7970a *trf;
1994	int uvolts, autosuspend_delay, ret;
1995	u32 clk_freq = TRF7970A_13MHZ_CLOCK_FREQUENCY;
1996
1997	if (!np) {
1998		dev_err(&spi->dev, "No Device Tree entry\n");
1999		return -EINVAL;
2000	}
2001
2002	trf = devm_kzalloc(&spi->dev, sizeof(*trf), GFP_KERNEL);
2003	if (!trf)
2004		return -ENOMEM;
2005
2006	trf->state = TRF7970A_ST_PWR_OFF;
2007	trf->dev = &spi->dev;
2008	trf->spi = spi;
2009
2010	spi->mode = SPI_MODE_1;
2011	spi->bits_per_word = 8;
2012
2013	ret = spi_setup(spi);
2014	if (ret < 0) {
2015		dev_err(trf->dev, "Can't set up SPI Communication\n");
2016		return ret;
2017	}
2018
2019	if (of_property_read_bool(np, "irq-status-read-quirk"))
2020		trf->quirks |= TRF7970A_QUIRK_IRQ_STATUS_READ;
2021
2022	/* There are two enable pins - only EN must be present in the DT */
2023	trf->en_gpiod = devm_gpiod_get_index(trf->dev, "ti,enable", 0,
2024					     GPIOD_OUT_LOW);
2025	if (IS_ERR(trf->en_gpiod)) {
2026		dev_err(trf->dev, "No EN GPIO property\n");
2027		return PTR_ERR(trf->en_gpiod);
2028	}
2029
2030	trf->en2_gpiod = devm_gpiod_get_index_optional(trf->dev, "ti,enable", 1,
2031						       GPIOD_OUT_LOW);
2032	if (!trf->en2_gpiod) {
2033		dev_info(trf->dev, "No EN2 GPIO property\n");
2034	} else if (IS_ERR(trf->en2_gpiod)) {
2035		dev_err(trf->dev, "Error getting EN2 GPIO property: %ld\n",
2036			PTR_ERR(trf->en2_gpiod));
2037		return PTR_ERR(trf->en2_gpiod);
2038	} else if (of_property_read_bool(np, "en2-rf-quirk")) {
2039		trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;
2040	}
2041
2042	of_property_read_u32(np, "clock-frequency", &clk_freq);
2043	if ((clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY) &&
2044	    (clk_freq != TRF7970A_13MHZ_CLOCK_FREQUENCY)) {
2045		dev_err(trf->dev,
2046			"clock-frequency (%u Hz) unsupported\n", clk_freq);
2047		return -EINVAL;
2048	}
2049
2050	if (clk_freq == TRF7970A_27MHZ_CLOCK_FREQUENCY) {
2051		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_27MHZ;
2052		dev_dbg(trf->dev, "trf7970a configured for 27MHz crystal\n");
2053	} else {
2054		trf->modulator_sys_clk_ctrl = 0;
2055	}
2056
2057	ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL,
2058					trf7970a_irq,
2059					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
2060					"trf7970a", trf);
2061	if (ret) {
2062		dev_err(trf->dev, "Can't request IRQ#%d: %d\n", spi->irq, ret);
2063		return ret;
2064	}
2065
2066	mutex_init(&trf->lock);
2067	INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
2068
2069	trf->vin_regulator = devm_regulator_get(&spi->dev, "vin");
2070	if (IS_ERR(trf->vin_regulator)) {
2071		ret = PTR_ERR(trf->vin_regulator);
2072		dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret);
2073		goto err_destroy_lock;
2074	}
2075
2076	ret = regulator_enable(trf->vin_regulator);
2077	if (ret) {
2078		dev_err(trf->dev, "Can't enable VIN: %d\n", ret);
2079		goto err_destroy_lock;
2080	}
2081
2082	uvolts = regulator_get_voltage(trf->vin_regulator);
2083	if (uvolts > 4000000)
2084		trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;
2085
2086	trf->vddio_regulator = devm_regulator_get(&spi->dev, "vdd-io");
2087	if (IS_ERR(trf->vddio_regulator)) {
2088		ret = PTR_ERR(trf->vddio_regulator);
2089		dev_err(trf->dev, "Can't get VDD_IO regulator: %d\n", ret);
2090		goto err_disable_vin_regulator;
2091	}
2092
2093	ret = regulator_enable(trf->vddio_regulator);
2094	if (ret) {
2095		dev_err(trf->dev, "Can't enable VDD_IO: %d\n", ret);
2096		goto err_disable_vin_regulator;
2097	}
2098
2099	if (regulator_get_voltage(trf->vddio_regulator) == 1800000) {
2100		trf->io_ctrl = TRF7970A_REG_IO_CTRL_IO_LOW;
2101		dev_dbg(trf->dev, "trf7970a config vdd_io to 1.8V\n");
2102	}
2103
2104	trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,
2105						TRF7970A_SUPPORTED_PROTOCOLS,
2106						NFC_DIGITAL_DRV_CAPS_IN_CRC |
2107						NFC_DIGITAL_DRV_CAPS_TG_CRC, 0,
2108						0);
2109	if (!trf->ddev) {
2110		dev_err(trf->dev, "Can't allocate NFC digital device\n");
2111		ret = -ENOMEM;
2112		goto err_disable_vddio_regulator;
2113	}
2114
2115	nfc_digital_set_parent_dev(trf->ddev, trf->dev);
2116	nfc_digital_set_drvdata(trf->ddev, trf);
2117	spi_set_drvdata(spi, trf);
2118
2119	autosuspend_delay = trf7970a_get_autosuspend_delay(np);
2120
2121	pm_runtime_set_autosuspend_delay(trf->dev, autosuspend_delay);
2122	pm_runtime_use_autosuspend(trf->dev);
2123
2124	ret = trf7970a_startup(trf);
2125	if (ret)
2126		goto err_free_ddev;
2127
2128	ret = nfc_digital_register_device(trf->ddev);
2129	if (ret) {
2130		dev_err(trf->dev, "Can't register NFC digital device: %d\n",
2131			ret);
2132		goto err_shutdown;
2133	}
2134
2135	return 0;
2136
2137err_shutdown:
2138	trf7970a_shutdown(trf);
2139err_free_ddev:
2140	nfc_digital_free_device(trf->ddev);
2141err_disable_vddio_regulator:
2142	regulator_disable(trf->vddio_regulator);
2143err_disable_vin_regulator:
2144	regulator_disable(trf->vin_regulator);
2145err_destroy_lock:
2146	mutex_destroy(&trf->lock);
2147	return ret;
2148}
2149
2150static void trf7970a_remove(struct spi_device *spi)
2151{
2152	struct trf7970a *trf = spi_get_drvdata(spi);
2153
2154	mutex_lock(&trf->lock);
2155
2156	trf7970a_shutdown(trf);
2157
2158	mutex_unlock(&trf->lock);
2159
2160	nfc_digital_unregister_device(trf->ddev);
2161	nfc_digital_free_device(trf->ddev);
2162
2163	regulator_disable(trf->vddio_regulator);
2164	regulator_disable(trf->vin_regulator);
2165
2166	mutex_destroy(&trf->lock);
2167}
2168
2169#ifdef CONFIG_PM_SLEEP
2170static int trf7970a_suspend(struct device *dev)
2171{
2172	struct spi_device *spi = to_spi_device(dev);
2173	struct trf7970a *trf = spi_get_drvdata(spi);
2174
2175	mutex_lock(&trf->lock);
2176
2177	trf7970a_shutdown(trf);
2178
2179	mutex_unlock(&trf->lock);
2180
2181	return 0;
2182}
2183
2184static int trf7970a_resume(struct device *dev)
2185{
2186	struct spi_device *spi = to_spi_device(dev);
2187	struct trf7970a *trf = spi_get_drvdata(spi);
2188	int ret;
2189
2190	mutex_lock(&trf->lock);
2191
2192	ret = trf7970a_startup(trf);
2193
2194	mutex_unlock(&trf->lock);
2195
2196	return ret;
2197}
2198#endif
2199
2200#ifdef CONFIG_PM
2201static int trf7970a_pm_runtime_suspend(struct device *dev)
2202{
2203	struct spi_device *spi = to_spi_device(dev);
2204	struct trf7970a *trf = spi_get_drvdata(spi);
2205	int ret;
2206
2207	mutex_lock(&trf->lock);
2208
2209	ret = trf7970a_power_down(trf);
2210
2211	mutex_unlock(&trf->lock);
2212
2213	return ret;
2214}
2215
2216static int trf7970a_pm_runtime_resume(struct device *dev)
2217{
2218	struct spi_device *spi = to_spi_device(dev);
2219	struct trf7970a *trf = spi_get_drvdata(spi);
2220	int ret;
2221
2222	ret = trf7970a_power_up(trf);
2223	if (!ret)
2224		pm_runtime_mark_last_busy(dev);
2225
2226	return ret;
2227}
2228#endif
2229
2230static const struct dev_pm_ops trf7970a_pm_ops = {
2231	SET_SYSTEM_SLEEP_PM_OPS(trf7970a_suspend, trf7970a_resume)
2232	SET_RUNTIME_PM_OPS(trf7970a_pm_runtime_suspend,
2233			   trf7970a_pm_runtime_resume, NULL)
2234};
2235
2236static const struct of_device_id trf7970a_of_match[] __maybe_unused = {
2237	{.compatible = "ti,trf7970a",},
2238	{},
2239};
2240
2241MODULE_DEVICE_TABLE(of, trf7970a_of_match);
2242
2243static const struct spi_device_id trf7970a_id_table[] = {
2244	{"trf7970a", 0},
2245	{}
2246};
2247
2248MODULE_DEVICE_TABLE(spi, trf7970a_id_table);
2249
2250static struct spi_driver trf7970a_spi_driver = {
2251	.probe		= trf7970a_probe,
2252	.remove		= trf7970a_remove,
2253	.id_table	= trf7970a_id_table,
2254	.driver	= {
2255		.name		= "trf7970a",
2256		.of_match_table	= of_match_ptr(trf7970a_of_match),
2257		.pm		= &trf7970a_pm_ops,
2258	},
2259};
2260
2261module_spi_driver(trf7970a_spi_driver);
2262
2263MODULE_AUTHOR("Mark A. Greer <mgreer@animalcreek.com>");
2264MODULE_LICENSE("GPL v2");
2265MODULE_DESCRIPTION("TI trf7970a RFID/NFC Transceiver Driver");