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