--- /dev/null
+/*
+ * TI TRF7970a RFID/NFC Transceiver Driver
+ *
+ * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
+ *
+ * Author: Erick Macias <emacias@ti.com>
+ * Author: Felipe Balbi <balbi@ti.com>
+ * Author: Mark A. Greer <mgreer@animalcreek.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 of
+ * the License as published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/netdevice.h>
+#include <linux/interrupt.h>
+#include <linux/pm_runtime.h>
+#include <linux/nfc.h>
+#include <linux/skbuff.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/spi/spi.h>
+#include <linux/regulator/consumer.h>
+
+#include <net/nfc/nfc.h>
+#include <net/nfc/digital.h>
+
+/* There are 3 ways the host can communicate with the trf7970a:
+ * parallel mode, SPI with Slave Select (SS) mode, and SPI without
+ * SS mode. The driver only supports the two SPI modes.
+ *
+ * The trf7970a is very timing sensitive and the VIN, EN2, and EN
+ * pins must asserted in that order and with specific delays in between.
+ * The delays used in the driver were provided by TI and have been
+ * confirmed to work with this driver. There is a bug with the current
+ * version of the trf7970a that requires that EN2 remain low no matter
+ * what. If it goes high, it will generate an RF field even when in
+ * passive target mode. TI has indicated that the chip will work okay
+ * when EN2 is left low. The 'en2-rf-quirk' device tree property
+ * indicates that trf7970a currently being used has the erratum and
+ * that EN2 must be kept low.
+ *
+ * Timeouts are implemented using the delayed workqueue kernel facility.
+ * Timeouts are required so things don't hang when there is no response
+ * from the trf7970a (or tag). Using this mechanism creates a race with
+ * interrupts, however. That is, an interrupt and a timeout could occur
+ * closely enough together that one is blocked by the mutex while the other
+ * executes. When the timeout handler executes first and blocks the
+ * interrupt handler, it will eventually set the state to IDLE so the
+ * interrupt handler will check the state and exit with no harm done.
+ * When the interrupt handler executes first and blocks the timeout handler,
+ * the cancel_delayed_work() call will know that it didn't cancel the
+ * work item (i.e., timeout) and will return zero. That return code is
+ * used by the timer handler to indicate that it should ignore the timeout
+ * once its unblocked.
+ *
+ * Aborting an active command isn't as simple as it seems because the only
+ * way to abort a command that's already been sent to the tag is so turn
+ * off power to the tag. If we do that, though, we'd have to go through
+ * the entire anticollision procedure again but the digital layer doesn't
+ * support that. So, if an abort is received before trf7970a_send_cmd()
+ * has sent the command to the tag, it simply returns -ECANCELED. If the
+ * command has already been sent to the tag, then the driver continues
+ * normally and recieves the response data (or error) but just before
+ * sending the data upstream, it frees the rx_skb and sends -ECANCELED
+ * upstream instead. If the command failed, that error will be sent
+ * upstream.
+ *
+ * When recieving data from a tag and the interrupt status register has
+ * only the SRX bit set, it means that all of the data has been received
+ * (once what's in the fifo has been read). However, depending on timing
+ * an interrupt status with only the SRX bit set may not be recived. In
+ * those cases, the timeout mechanism is used to wait 20 ms in case more
+ * data arrives. After 20 ms, it is assumed that all of the data has been
+ * received and the accumulated rx data is sent upstream. The
+ * 'TRF7970A_ST_WAIT_FOR_RX_DATA_CONT' state is used for this purpose
+ * (i.e., it indicates that some data has been received but we're not sure
+ * if there is more coming so a timeout in this state means all data has
+ * been received and there isn't an error). The delay is 20 ms since delays
+ * of ~16 ms have been observed during testing.
+ *
+ * When transmitting a frame larger than the FIFO size (127 bytes), the
+ * driver will wait 20 ms for the FIFO to drain past the low-watermark
+ * and generate an interrupt. The low-watermark set to 32 bytes so the
+ * interrupt should fire after 127 - 32 = 95 bytes have been sent. At
+ * the lowest possible bit rate (6.62 kbps for 15693), it will take up
+ * to ~14.35 ms so 20 ms is used for the timeout.
+ *
+ * Type 2 write and sector select commands respond with a 4-bit ACK or NACK.
+ * Having only 4 bits in the FIFO won't normally generate an interrupt so
+ * driver enables the '4_bit_RX' bit of the Special Functions register 1
+ * to cause an interrupt in that case. Leaving that bit for a read command
+ * messes up the data returned so it is only enabled when the framing is
+ * 'NFC_DIGITAL_FRAMING_NFCA_T2T' and the command is not a read command.
+ * Unfortunately, that means that the driver has to peek into tx frames
+ * when the framing is 'NFC_DIGITAL_FRAMING_NFCA_T2T'. This is done by
+ * the trf7970a_per_cmd_config() routine.
+ *
+ * ISO/IEC 15693 frames specify whether to use single or double sub-carrier
+ * frequencies and whether to use low or high data rates in the flags byte
+ * of the frame. This means that the driver has to peek at all 15693 frames
+ * to determine what speed to set the communication to. In addition, write
+ * and lock commands use the OPTION flag to indicate that an EOF must be
+ * sent to the tag before it will send its response. So the driver has to
+ * examine all frames for that reason too.
+ *
+ * It is unclear how long to wait before sending the EOF. According to the
+ * Note under Table 1-1 in section 1.6 of
+ * http://www.ti.com/lit/ug/scbu011/scbu011.pdf, that wait should be at least
+ * 10 ms for TI Tag-it HF-I tags; however testing has shown that is not long
+ * enough so 20 ms is used. So the timer is set to 40 ms - 20 ms to drain
+ * up to 127 bytes in the FIFO at the lowest bit rate plus another 20 ms to
+ * ensure the wait is long enough before sending the EOF. This seems to work
+ * reliably.
+ */
+
+#define TRF7970A_SUPPORTED_PROTOCOLS \
+ (NFC_PROTO_MIFARE_MASK | NFC_PROTO_ISO14443_MASK | \
+ NFC_PROTO_ISO14443_B_MASK | NFC_PROTO_FELICA_MASK | \
+ NFC_PROTO_ISO15693_MASK | NFC_PROTO_NFC_DEP_MASK)
+
+#define TRF7970A_AUTOSUSPEND_DELAY 30000 /* 30 seconds */
+
+#define TRF7970A_RX_SKB_ALLOC_SIZE 256
+
+#define TRF7970A_FIFO_SIZE 127
+
+/* TX length is 3 nibbles long ==> 4KB - 1 bytes max */
+#define TRF7970A_TX_MAX (4096 - 1)
+
+#define TRF7970A_WAIT_FOR_TX_IRQ 20
+#define TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT 20
+#define TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT 20
+#define TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF 40
+
+/* Guard times for various RF technologies (in us) */
+#define TRF7970A_GUARD_TIME_NFCA 5000
+#define TRF7970A_GUARD_TIME_NFCB 5000
+#define TRF7970A_GUARD_TIME_NFCF 20000
+#define TRF7970A_GUARD_TIME_15693 1000
+
+/* Quirks */
+/* Erratum: When reading IRQ Status register on trf7970a, we must issue a
+ * read continuous command for IRQ Status and Collision Position registers.
+ */
+#define TRF7970A_QUIRK_IRQ_STATUS_READ BIT(0)
+#define TRF7970A_QUIRK_EN2_MUST_STAY_LOW BIT(1)
+
+/* Direct commands */
+#define TRF7970A_CMD_IDLE 0x00
+#define TRF7970A_CMD_SOFT_INIT 0x03
+#define TRF7970A_CMD_RF_COLLISION 0x04
+#define TRF7970A_CMD_RF_COLLISION_RESPONSE_N 0x05
+#define TRF7970A_CMD_RF_COLLISION_RESPONSE_0 0x06
+#define TRF7970A_CMD_FIFO_RESET 0x0f
+#define TRF7970A_CMD_TRANSMIT_NO_CRC 0x10
+#define TRF7970A_CMD_TRANSMIT 0x11
+#define TRF7970A_CMD_DELAY_TRANSMIT_NO_CRC 0x12
+#define TRF7970A_CMD_DELAY_TRANSMIT 0x13
+#define TRF7970A_CMD_EOF 0x14
+#define TRF7970A_CMD_CLOSE_SLOT 0x15
+#define TRF7970A_CMD_BLOCK_RX 0x16
+#define TRF7970A_CMD_ENABLE_RX 0x17
+#define TRF7970A_CMD_TEST_INT_RF 0x18
+#define TRF7970A_CMD_TEST_EXT_RF 0x19
+#define TRF7970A_CMD_RX_GAIN_ADJUST 0x1a
+
+/* Bits determining whether its a direct command or register R/W,
+ * whether to use a continuous SPI transaction or not, and the actual
+ * direct cmd opcode or regster address.
+ */
+#define TRF7970A_CMD_BIT_CTRL BIT(7)
+#define TRF7970A_CMD_BIT_RW BIT(6)
+#define TRF7970A_CMD_BIT_CONTINUOUS BIT(5)
+#define TRF7970A_CMD_BIT_OPCODE(opcode) ((opcode) & 0x1f)
+
+/* Registers addresses */
+#define TRF7970A_CHIP_STATUS_CTRL 0x00
+#define TRF7970A_ISO_CTRL 0x01
+#define TRF7970A_ISO14443B_TX_OPTIONS 0x02
+#define TRF7970A_ISO14443A_HIGH_BITRATE_OPTIONS 0x03
+#define TRF7970A_TX_TIMER_SETTING_H_BYTE 0x04
+#define TRF7970A_TX_TIMER_SETTING_L_BYTE 0x05
+#define TRF7970A_TX_PULSE_LENGTH_CTRL 0x06
+#define TRF7970A_RX_NO_RESPONSE_WAIT 0x07
+#define TRF7970A_RX_WAIT_TIME 0x08
+#define TRF7970A_MODULATOR_SYS_CLK_CTRL 0x09
+#define TRF7970A_RX_SPECIAL_SETTINGS 0x0a
+#define TRF7970A_REG_IO_CTRL 0x0b
+#define TRF7970A_IRQ_STATUS 0x0c
+#define TRF7970A_COLLISION_IRQ_MASK 0x0d
+#define TRF7970A_COLLISION_POSITION 0x0e
+#define TRF7970A_RSSI_OSC_STATUS 0x0f
+#define TRF7970A_SPECIAL_FCN_REG1 0x10
+#define TRF7970A_SPECIAL_FCN_REG2 0x11
+#define TRF7970A_RAM1 0x12
+#define TRF7970A_RAM2 0x13
+#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS 0x14
+#define TRF7970A_NFC_LOW_FIELD_LEVEL 0x16
+#define TRF7970A_NFCID1 0x17
+#define TRF7970A_NFC_TARGET_LEVEL 0x18
+#define TRF79070A_NFC_TARGET_PROTOCOL 0x19
+#define TRF7970A_TEST_REGISTER1 0x1a
+#define TRF7970A_TEST_REGISTER2 0x1b
+#define TRF7970A_FIFO_STATUS 0x1c
+#define TRF7970A_TX_LENGTH_BYTE1 0x1d
+#define TRF7970A_TX_LENGTH_BYTE2 0x1e
+#define TRF7970A_FIFO_IO_REGISTER 0x1f
+
+/* Chip Status Control Register Bits */
+#define TRF7970A_CHIP_STATUS_VRS5_3 BIT(0)
+#define TRF7970A_CHIP_STATUS_REC_ON BIT(1)
+#define TRF7970A_CHIP_STATUS_AGC_ON BIT(2)
+#define TRF7970A_CHIP_STATUS_PM_ON BIT(3)
+#define TRF7970A_CHIP_STATUS_RF_PWR BIT(4)
+#define TRF7970A_CHIP_STATUS_RF_ON BIT(5)
+#define TRF7970A_CHIP_STATUS_DIRECT BIT(6)
+#define TRF7970A_CHIP_STATUS_STBY BIT(7)
+
+/* ISO Control Register Bits */
+#define TRF7970A_ISO_CTRL_15693_SGL_1OF4_662 0x00
+#define TRF7970A_ISO_CTRL_15693_SGL_1OF256_662 0x01
+#define TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648 0x02
+#define TRF7970A_ISO_CTRL_15693_SGL_1OF256_2648 0x03
+#define TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a 0x04
+#define TRF7970A_ISO_CTRL_15693_DBL_1OF256_667 0x05
+#define TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669 0x06
+#define TRF7970A_ISO_CTRL_15693_DBL_1OF256_2669 0x07
+#define TRF7970A_ISO_CTRL_14443A_106 0x08
+#define TRF7970A_ISO_CTRL_14443A_212 0x09
+#define TRF7970A_ISO_CTRL_14443A_424 0x0a
+#define TRF7970A_ISO_CTRL_14443A_848 0x0b
+#define TRF7970A_ISO_CTRL_14443B_106 0x0c
+#define TRF7970A_ISO_CTRL_14443B_212 0x0d
+#define TRF7970A_ISO_CTRL_14443B_424 0x0e
+#define TRF7970A_ISO_CTRL_14443B_848 0x0f
+#define TRF7970A_ISO_CTRL_FELICA_212 0x1a
+#define TRF7970A_ISO_CTRL_FELICA_424 0x1b
+#define TRF7970A_ISO_CTRL_NFC_NFCA_106 0x01
+#define TRF7970A_ISO_CTRL_NFC_NFCF_212 0x02
+#define TRF7970A_ISO_CTRL_NFC_NFCF_424 0x03
+#define TRF7970A_ISO_CTRL_NFC_CE_14443A 0x00
+#define TRF7970A_ISO_CTRL_NFC_CE_14443B 0x01
+#define TRF7970A_ISO_CTRL_NFC_CE BIT(2)
+#define TRF7970A_ISO_CTRL_NFC_ACTIVE BIT(3)
+#define TRF7970A_ISO_CTRL_NFC_INITIATOR BIT(4)
+#define TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE BIT(5)
+#define TRF7970A_ISO_CTRL_RFID BIT(5)
+#define TRF7970A_ISO_CTRL_DIR_MODE BIT(6)
+#define TRF7970A_ISO_CTRL_RX_CRC_N BIT(7) /* true == No CRC */
+
+#define TRF7970A_ISO_CTRL_RFID_SPEED_MASK 0x1f
+
+/* Modulator and SYS_CLK Control Register Bits */
+#define TRF7970A_MODULATOR_DEPTH(n) ((n) & 0x7)
+#define TRF7970A_MODULATOR_DEPTH_ASK10 (TRF7970A_MODULATOR_DEPTH(0))
+#define TRF7970A_MODULATOR_DEPTH_OOK (TRF7970A_MODULATOR_DEPTH(1))
+#define TRF7970A_MODULATOR_DEPTH_ASK7 (TRF7970A_MODULATOR_DEPTH(2))
+#define TRF7970A_MODULATOR_DEPTH_ASK8_5 (TRF7970A_MODULATOR_DEPTH(3))
+#define TRF7970A_MODULATOR_DEPTH_ASK13 (TRF7970A_MODULATOR_DEPTH(4))
+#define TRF7970A_MODULATOR_DEPTH_ASK16 (TRF7970A_MODULATOR_DEPTH(5))
+#define TRF7970A_MODULATOR_DEPTH_ASK22 (TRF7970A_MODULATOR_DEPTH(6))
+#define TRF7970A_MODULATOR_DEPTH_ASK30 (TRF7970A_MODULATOR_DEPTH(7))
+#define TRF7970A_MODULATOR_EN_ANA BIT(3)
+#define TRF7970A_MODULATOR_CLK(n) (((n) & 0x3) << 4)
+#define TRF7970A_MODULATOR_CLK_DISABLED (TRF7970A_MODULATOR_CLK(0))
+#define TRF7970A_MODULATOR_CLK_3_6 (TRF7970A_MODULATOR_CLK(1))
+#define TRF7970A_MODULATOR_CLK_6_13 (TRF7970A_MODULATOR_CLK(2))
+#define TRF7970A_MODULATOR_CLK_13_27 (TRF7970A_MODULATOR_CLK(3))
+#define TRF7970A_MODULATOR_EN_OOK BIT(6)
+#define TRF7970A_MODULATOR_27MHZ BIT(7)
+
+#define TRF7970A_RX_SPECIAL_SETTINGS_NO_LIM BIT(0)
+#define TRF7970A_RX_SPECIAL_SETTINGS_AGCR BIT(1)
+#define TRF7970A_RX_SPECIAL_SETTINGS_GD_0DB (0x0 << 2)
+#define TRF7970A_RX_SPECIAL_SETTINGS_GD_5DB (0x1 << 2)
+#define TRF7970A_RX_SPECIAL_SETTINGS_GD_10DB (0x2 << 2)
+#define TRF7970A_RX_SPECIAL_SETTINGS_GD_15DB (0x3 << 2)
+#define TRF7970A_RX_SPECIAL_SETTINGS_HBT BIT(4)
+#define TRF7970A_RX_SPECIAL_SETTINGS_M848 BIT(5)
+#define TRF7970A_RX_SPECIAL_SETTINGS_C424 BIT(6)
+#define TRF7970A_RX_SPECIAL_SETTINGS_C212 BIT(7)
+
+#define TRF7970A_REG_IO_CTRL_VRS(v) ((v) & 0x07)
+#define TRF7970A_REG_IO_CTRL_IO_LOW BIT(5)
+#define TRF7970A_REG_IO_CTRL_EN_EXT_PA BIT(6)
+#define TRF7970A_REG_IO_CTRL_AUTO_REG BIT(7)
+
+/* IRQ Status Register Bits */
+#define TRF7970A_IRQ_STATUS_NORESP BIT(0) /* ISO15693 only */
+#define TRF7970A_IRQ_STATUS_NFC_COL_ERROR BIT(0)
+#define TRF7970A_IRQ_STATUS_COL BIT(1)
+#define TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR BIT(2)
+#define TRF7970A_IRQ_STATUS_NFC_RF BIT(2)
+#define TRF7970A_IRQ_STATUS_PARITY_ERROR BIT(3)
+#define TRF7970A_IRQ_STATUS_NFC_SDD BIT(3)
+#define TRF7970A_IRQ_STATUS_CRC_ERROR BIT(4)
+#define TRF7970A_IRQ_STATUS_NFC_PROTO_ERROR BIT(4)
+#define TRF7970A_IRQ_STATUS_FIFO BIT(5)
+#define TRF7970A_IRQ_STATUS_SRX BIT(6)
+#define TRF7970A_IRQ_STATUS_TX BIT(7)
+
+#define TRF7970A_IRQ_STATUS_ERROR \
+ (TRF7970A_IRQ_STATUS_COL | \
+ TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR | \
+ TRF7970A_IRQ_STATUS_PARITY_ERROR | \
+ TRF7970A_IRQ_STATUS_CRC_ERROR)
+
+#define TRF7970A_RSSI_OSC_STATUS_RSSI_MASK (BIT(2) | BIT(1) | BIT(0))
+#define TRF7970A_RSSI_OSC_STATUS_RSSI_X_MASK (BIT(5) | BIT(4) | BIT(3))
+#define TRF7970A_RSSI_OSC_STATUS_RSSI_OSC_OK BIT(6)
+
+#define TRF7970A_SPECIAL_FCN_REG1_COL_7_6 BIT(0)
+#define TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL BIT(1)
+#define TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX BIT(2)
+#define TRF7970A_SPECIAL_FCN_REG1_SP_DIR_MODE BIT(3)
+#define TRF7970A_SPECIAL_FCN_REG1_NEXT_SLOT_37US BIT(4)
+#define TRF7970A_SPECIAL_FCN_REG1_PAR43 BIT(5)
+
+#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_124 (0x0 << 2)
+#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_120 (0x1 << 2)
+#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_112 (0x2 << 2)
+#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 (0x3 << 2)
+#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_4 0x0
+#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_8 0x1
+#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_16 0x2
+#define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32 0x3
+
+#define TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(v) ((v) & 0x07)
+#define TRF7970A_NFC_LOW_FIELD_LEVEL_CLEX_DIS BIT(7)
+
+#define TRF7970A_NFC_TARGET_LEVEL_RFDET(v) ((v) & 0x07)
+#define TRF7970A_NFC_TARGET_LEVEL_HI_RF BIT(3)
+#define TRF7970A_NFC_TARGET_LEVEL_SDD_EN BIT(3)
+#define TRF7970A_NFC_TARGET_LEVEL_LD_S_4BYTES (0x0 << 6)
+#define TRF7970A_NFC_TARGET_LEVEL_LD_S_7BYTES (0x1 << 6)
+#define TRF7970A_NFC_TARGET_LEVEL_LD_S_10BYTES (0x2 << 6)
+
+#define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106 BIT(0)
+#define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212 BIT(1)
+#define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424 (BIT(0) | BIT(1))
+#define TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B BIT(2)
+#define TRF79070A_NFC_TARGET_PROTOCOL_PAS_106 BIT(3)
+#define TRF79070A_NFC_TARGET_PROTOCOL_FELICA BIT(4)
+#define TRF79070A_NFC_TARGET_PROTOCOL_RF_L BIT(6)
+#define TRF79070A_NFC_TARGET_PROTOCOL_RF_H BIT(7)
+
+#define TRF79070A_NFC_TARGET_PROTOCOL_106A \
+ (TRF79070A_NFC_TARGET_PROTOCOL_RF_H | \
+ TRF79070A_NFC_TARGET_PROTOCOL_RF_L | \
+ TRF79070A_NFC_TARGET_PROTOCOL_PAS_106 | \
+ TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
+
+#define TRF79070A_NFC_TARGET_PROTOCOL_106B \
+ (TRF79070A_NFC_TARGET_PROTOCOL_RF_H | \
+ TRF79070A_NFC_TARGET_PROTOCOL_RF_L | \
+ TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B | \
+ TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
+
+#define TRF79070A_NFC_TARGET_PROTOCOL_212F \
+ (TRF79070A_NFC_TARGET_PROTOCOL_RF_H | \
+ TRF79070A_NFC_TARGET_PROTOCOL_RF_L | \
+ TRF79070A_NFC_TARGET_PROTOCOL_FELICA | \
+ TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212)
+
+#define TRF79070A_NFC_TARGET_PROTOCOL_424F \
+ (TRF79070A_NFC_TARGET_PROTOCOL_RF_H | \
+ TRF79070A_NFC_TARGET_PROTOCOL_RF_L | \
+ TRF79070A_NFC_TARGET_PROTOCOL_FELICA | \
+ TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424)
+
+#define TRF7970A_FIFO_STATUS_OVERFLOW BIT(7)
+
+/* NFC (ISO/IEC 14443A) Type 2 Tag commands */
+#define NFC_T2T_CMD_READ 0x30
+
+/* ISO 15693 commands codes */
+#define ISO15693_CMD_INVENTORY 0x01
+#define ISO15693_CMD_READ_SINGLE_BLOCK 0x20
+#define ISO15693_CMD_WRITE_SINGLE_BLOCK 0x21
+#define ISO15693_CMD_LOCK_BLOCK 0x22
+#define ISO15693_CMD_READ_MULTIPLE_BLOCK 0x23
+#define ISO15693_CMD_WRITE_MULTIPLE_BLOCK 0x24
+#define ISO15693_CMD_SELECT 0x25
+#define ISO15693_CMD_RESET_TO_READY 0x26
+#define ISO15693_CMD_WRITE_AFI 0x27
+#define ISO15693_CMD_LOCK_AFI 0x28
+#define ISO15693_CMD_WRITE_DSFID 0x29
+#define ISO15693_CMD_LOCK_DSFID 0x2a
+#define ISO15693_CMD_GET_SYSTEM_INFO 0x2b
+#define ISO15693_CMD_GET_MULTIPLE_BLOCK_SECURITY_STATUS 0x2c
+
+/* ISO 15693 request and response flags */
+#define ISO15693_REQ_FLAG_SUB_CARRIER BIT(0)
+#define ISO15693_REQ_FLAG_DATA_RATE BIT(1)
+#define ISO15693_REQ_FLAG_INVENTORY BIT(2)
+#define ISO15693_REQ_FLAG_PROTOCOL_EXT BIT(3)
+#define ISO15693_REQ_FLAG_SELECT BIT(4)
+#define ISO15693_REQ_FLAG_AFI BIT(4)
+#define ISO15693_REQ_FLAG_ADDRESS BIT(5)
+#define ISO15693_REQ_FLAG_NB_SLOTS BIT(5)
+#define ISO15693_REQ_FLAG_OPTION BIT(6)
+
+#define ISO15693_REQ_FLAG_SPEED_MASK \
+ (ISO15693_REQ_FLAG_SUB_CARRIER | ISO15693_REQ_FLAG_DATA_RATE)
+
+enum trf7970a_state {
+ TRF7970A_ST_PWR_OFF,
+ TRF7970A_ST_RF_OFF,
+ TRF7970A_ST_IDLE,
+ TRF7970A_ST_IDLE_RX_BLOCKED,
+ TRF7970A_ST_WAIT_FOR_TX_FIFO,
+ TRF7970A_ST_WAIT_FOR_RX_DATA,
+ TRF7970A_ST_WAIT_FOR_RX_DATA_CONT,
+ TRF7970A_ST_WAIT_TO_ISSUE_EOF,
+ TRF7970A_ST_LISTENING,
+ TRF7970A_ST_LISTENING_MD,
+ TRF7970A_ST_MAX
+};
+
+struct trf7970a {
+ enum trf7970a_state state;
+ struct device *dev;
+ struct spi_device *spi;
+ struct regulator *regulator;
+ struct nfc_digital_dev *ddev;
+ u32 quirks;
+ bool is_initiator;
+ bool aborting;
+ struct sk_buff *tx_skb;
+ struct sk_buff *rx_skb;
+ nfc_digital_cmd_complete_t cb;
+ void *cb_arg;
+ u8 chip_status_ctrl;
+ u8 iso_ctrl;
+ u8 iso_ctrl_tech;
+ u8 modulator_sys_clk_ctrl;
+ u8 special_fcn_reg1;
+ unsigned int guard_time;
+ int technology;
+ int framing;
+ u8 md_rf_tech;
+ u8 tx_cmd;
+ bool issue_eof;
+ int en2_gpio;
+ int en_gpio;
+ struct mutex lock;
+ unsigned int timeout;
+ bool ignore_timeout;
+ struct delayed_work timeout_work;
+};
+
+
+static int trf7970a_cmd(struct trf7970a *trf, u8 opcode)
+{
+ u8 cmd = TRF7970A_CMD_BIT_CTRL | TRF7970A_CMD_BIT_OPCODE(opcode);
+ int ret;
+
+ dev_dbg(trf->dev, "cmd: 0x%x\n", cmd);
+
+ ret = spi_write(trf->spi, &cmd, 1);
+ if (ret)
+ dev_err(trf->dev, "%s - cmd: 0x%x, ret: %d\n", __func__, cmd,
+ ret);
+ return ret;
+}
+
+static int trf7970a_read(struct trf7970a *trf, u8 reg, u8 *val)
+{
+ u8 addr = TRF7970A_CMD_BIT_RW | reg;
+ int ret;
+
+ ret = spi_write_then_read(trf->spi, &addr, 1, val, 1);
+ if (ret)
+ dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
+ ret);
+
+ dev_dbg(trf->dev, "read(0x%x): 0x%x\n", addr, *val);
+
+ return ret;
+}
+
+static int trf7970a_read_cont(struct trf7970a *trf, u8 reg, u8 *buf, size_t len)
+{
+ u8 addr = reg | TRF7970A_CMD_BIT_RW | TRF7970A_CMD_BIT_CONTINUOUS;
+ struct spi_transfer t[2];
+ struct spi_message m;
+ int ret;
+
+ dev_dbg(trf->dev, "read_cont(0x%x, %zd)\n", addr, len);
+
+ spi_message_init(&m);
+
+ memset(&t, 0, sizeof(t));
+
+ t[0].tx_buf = &addr;
+ t[0].len = sizeof(addr);
+ spi_message_add_tail(&t[0], &m);
+
+ t[1].rx_buf = buf;
+ t[1].len = len;
+ spi_message_add_tail(&t[1], &m);
+
+ ret = spi_sync(trf->spi, &m);
+ if (ret)
+ dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
+ ret);
+ return ret;
+}
+
+static int trf7970a_write(struct trf7970a *trf, u8 reg, u8 val)
+{
+ u8 buf[2] = { reg, val };
+ int ret;
+
+ dev_dbg(trf->dev, "write(0x%x): 0x%x\n", reg, val);
+
+ ret = spi_write(trf->spi, buf, 2);
+ if (ret)
+ dev_err(trf->dev, "%s - write: 0x%x 0x%x, ret: %d\n", __func__,
+ buf[0], buf[1], ret);
+
+ return ret;
+}
+
+static int trf7970a_read_irqstatus(struct trf7970a *trf, u8 *status)
+{
+ int ret;
+ u8 buf[2];
+ u8 addr;
+
+ addr = TRF7970A_IRQ_STATUS | TRF7970A_CMD_BIT_RW;
+
+ if (trf->quirks & TRF7970A_QUIRK_IRQ_STATUS_READ) {
+ addr |= TRF7970A_CMD_BIT_CONTINUOUS;
+ ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
+ } else {
+ ret = spi_write_then_read(trf->spi, &addr, 1, buf, 1);
+ }
+
+ if (ret)
+ dev_err(trf->dev, "%s - irqstatus: Status read failed: %d\n",
+ __func__, ret);
+ else
+ *status = buf[0];
+
+ return ret;
+}
+
+static int trf7970a_read_target_proto(struct trf7970a *trf, u8 *target_proto)
+{
+ int ret;
+ u8 buf[2];
+ u8 addr;
+
+ addr = TRF79070A_NFC_TARGET_PROTOCOL | TRF7970A_CMD_BIT_RW |
+ TRF7970A_CMD_BIT_CONTINUOUS;
+
+ ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
+ if (ret)
+ dev_err(trf->dev, "%s - target_proto: Read failed: %d\n",
+ __func__, ret);
+ else
+ *target_proto = buf[0];
+
+ return ret;
+}
+
+static int trf7970a_mode_detect(struct trf7970a *trf, u8 *rf_tech)
+{
+ int ret;
+ u8 target_proto, tech;
+
+ ret = trf7970a_read_target_proto(trf, &target_proto);
+ if (ret)
+ return ret;
+
+ switch (target_proto) {
+ case TRF79070A_NFC_TARGET_PROTOCOL_106A:
+ tech = NFC_DIGITAL_RF_TECH_106A;
+ break;
+ case TRF79070A_NFC_TARGET_PROTOCOL_106B:
+ tech = NFC_DIGITAL_RF_TECH_106B;
+ break;
+ case TRF79070A_NFC_TARGET_PROTOCOL_212F:
+ tech = NFC_DIGITAL_RF_TECH_212F;
+ break;
+ case TRF79070A_NFC_TARGET_PROTOCOL_424F:
+ tech = NFC_DIGITAL_RF_TECH_424F;
+ break;
+ default:
+ dev_dbg(trf->dev, "%s - mode_detect: target_proto: 0x%x\n",
+ __func__, target_proto);
+ return -EIO;
+ }
+
+ *rf_tech = tech;
+
+ return ret;
+}
+
+static void trf7970a_send_upstream(struct trf7970a *trf)
+{
+ dev_kfree_skb_any(trf->tx_skb);
+ trf->tx_skb = NULL;
+
+ if (trf->rx_skb && !IS_ERR(trf->rx_skb) && !trf->aborting)
+ print_hex_dump_debug("trf7970a rx data: ", DUMP_PREFIX_NONE,
+ 16, 1, trf->rx_skb->data, trf->rx_skb->len,
+ false);
+
+ trf->state = TRF7970A_ST_IDLE;
+
+ if (trf->aborting) {
+ dev_dbg(trf->dev, "Abort process complete\n");
+
+ if (!IS_ERR(trf->rx_skb)) {
+ kfree_skb(trf->rx_skb);
+ trf->rx_skb = ERR_PTR(-ECANCELED);
+ }
+
+ trf->aborting = false;
+ }
+
+ trf->cb(trf->ddev, trf->cb_arg, trf->rx_skb);
+
+ trf->rx_skb = NULL;
+}
+
+static void trf7970a_send_err_upstream(struct trf7970a *trf, int errno)
+{
+ dev_dbg(trf->dev, "Error - state: %d, errno: %d\n", trf->state, errno);
+
+ cancel_delayed_work(&trf->timeout_work);
+
+ kfree_skb(trf->rx_skb);
+ trf->rx_skb = ERR_PTR(errno);
+
+ trf7970a_send_upstream(trf);
+}
+
+static int trf7970a_transmit(struct trf7970a *trf, struct sk_buff *skb,
+ unsigned int len, u8 *prefix, unsigned int prefix_len)
+{
+ struct spi_transfer t[2];
+ struct spi_message m;
+ unsigned int timeout;
+ int ret;
+
+ print_hex_dump_debug("trf7970a tx data: ", DUMP_PREFIX_NONE,
+ 16, 1, skb->data, len, false);
+
+ spi_message_init(&m);
+
+ memset(&t, 0, sizeof(t));
+
+ t[0].tx_buf = prefix;
+ t[0].len = prefix_len;
+ spi_message_add_tail(&t[0], &m);
+
+ t[1].tx_buf = skb->data;
+ t[1].len = len;
+ spi_message_add_tail(&t[1], &m);
+
+ ret = spi_sync(trf->spi, &m);
+ if (ret) {
+ dev_err(trf->dev, "%s - Can't send tx data: %d\n", __func__,
+ ret);
+ return ret;
+ }
+
+ skb_pull(skb, len);
+
+ if (skb->len > 0) {
+ trf->state = TRF7970A_ST_WAIT_FOR_TX_FIFO;
+ timeout = TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT;
+ } else {
+ if (trf->issue_eof) {
+ trf->state = TRF7970A_ST_WAIT_TO_ISSUE_EOF;
+ timeout = TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF;
+ } else {
+ trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
+
+ if (!trf->timeout)
+ timeout = TRF7970A_WAIT_FOR_TX_IRQ;
+ else
+ timeout = trf->timeout;
+ }
+ }
+
+ dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n", timeout,
+ trf->state);
+
+ schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
+
+ return 0;
+}
+
+static void trf7970a_fill_fifo(struct trf7970a *trf)
+{
+ struct sk_buff *skb = trf->tx_skb;
+ unsigned int len;
+ int ret;
+ u8 fifo_bytes;
+ u8 prefix;
+
+ ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
+ if (ret) {
+ trf7970a_send_err_upstream(trf, ret);
+ return;
+ }
+
+ dev_dbg(trf->dev, "Filling FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
+
+ fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
+
+ /* Calculate how much more data can be written to the fifo */
+ len = TRF7970A_FIFO_SIZE - fifo_bytes;
+ if (!len) {
+ schedule_delayed_work(&trf->timeout_work,
+ msecs_to_jiffies(TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT));
+ return;
+ }
+
+ len = min(skb->len, len);
+
+ prefix = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_FIFO_IO_REGISTER;
+
+ ret = trf7970a_transmit(trf, skb, len, &prefix, sizeof(prefix));
+ if (ret)
+ trf7970a_send_err_upstream(trf, ret);
+}
+
+static void trf7970a_drain_fifo(struct trf7970a *trf, u8 status)
+{
+ struct sk_buff *skb = trf->rx_skb;
+ int ret;
+ u8 fifo_bytes;
+
+ if (status & TRF7970A_IRQ_STATUS_ERROR) {
+ trf7970a_send_err_upstream(trf, -EIO);
+ return;
+ }
+
+ ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
+ if (ret) {
+ trf7970a_send_err_upstream(trf, ret);
+ return;
+ }
+
+ dev_dbg(trf->dev, "Draining FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
+
+ fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
+
+ if (!fifo_bytes)
+ goto no_rx_data;
+
+ if (fifo_bytes > skb_tailroom(skb)) {
+ skb = skb_copy_expand(skb, skb_headroom(skb),
+ max_t(int, fifo_bytes,
+ TRF7970A_RX_SKB_ALLOC_SIZE),
+ GFP_KERNEL);
+ if (!skb) {
+ trf7970a_send_err_upstream(trf, -ENOMEM);
+ return;
+ }
+
+ kfree_skb(trf->rx_skb);
+ trf->rx_skb = skb;
+ }
+
+ ret = trf7970a_read_cont(trf, TRF7970A_FIFO_IO_REGISTER,
+ skb_put(skb, fifo_bytes), fifo_bytes);
+ if (ret) {
+ trf7970a_send_err_upstream(trf, ret);
+ return;
+ }
+
+ /* If received Type 2 ACK/NACK, shift right 4 bits and pass up */
+ if ((trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T) && (skb->len == 1) &&
+ (trf->special_fcn_reg1 ==
+ TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX)) {
+ skb->data[0] >>= 4;
+ status = TRF7970A_IRQ_STATUS_SRX;
+ } else {
+ trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA_CONT;
+
+ ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
+ if (ret) {
+ trf7970a_send_err_upstream(trf, ret);
+ return;
+ }
+
+ fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
+
+ /* If there are bytes in the FIFO, set status to '0' so
+ * the if stmt below doesn't fire and the driver will wait
+ * for the trf7970a to generate another RX interrupt.
+ */
+ if (fifo_bytes)
+ status = 0;
+ }
+
+no_rx_data:
+ if (status == TRF7970A_IRQ_STATUS_SRX) { /* Receive complete */
+ trf7970a_send_upstream(trf);
+ return;
+ }
+
+ dev_dbg(trf->dev, "Setting timeout for %d ms\n",
+ TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT);
+
+ schedule_delayed_work(&trf->timeout_work,
+ msecs_to_jiffies(TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT));
+}
+
+static irqreturn_t trf7970a_irq(int irq, void *dev_id)
+{
+ struct trf7970a *trf = dev_id;
+ int ret;
+ u8 status, fifo_bytes, iso_ctrl;
+
+ mutex_lock(&trf->lock);
+
+ if (trf->state == TRF7970A_ST_RF_OFF) {
+ mutex_unlock(&trf->lock);
+ return IRQ_NONE;
+ }
+
+ ret = trf7970a_read_irqstatus(trf, &status);
+ if (ret) {
+ mutex_unlock(&trf->lock);
+ return IRQ_NONE;
+ }
+
+ dev_dbg(trf->dev, "IRQ - state: %d, status: 0x%x\n", trf->state,
+ status);
+
+ if (!status) {
+ mutex_unlock(&trf->lock);
+ return IRQ_NONE;
+ }
+
+ switch (trf->state) {
+ case TRF7970A_ST_IDLE:
+ case TRF7970A_ST_IDLE_RX_BLOCKED:
+ /* If initiator and getting interrupts caused by RF noise,
+ * turn off the receiver to avoid unnecessary interrupts.
+ * It will be turned back on in trf7970a_send_cmd() when
+ * the next command is issued.
+ */
+ if (trf->is_initiator && (status & TRF7970A_IRQ_STATUS_ERROR)) {
+ trf7970a_cmd(trf, TRF7970A_CMD_BLOCK_RX);
+ trf->state = TRF7970A_ST_IDLE_RX_BLOCKED;
+ }
+
+ trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
+ break;
+ case TRF7970A_ST_WAIT_FOR_TX_FIFO:
+ if (status & TRF7970A_IRQ_STATUS_TX) {
+ trf->ignore_timeout =
+ !cancel_delayed_work(&trf->timeout_work);
+ trf7970a_fill_fifo(trf);
+ } else {
+ trf7970a_send_err_upstream(trf, -EIO);
+ }
+ break;
+ case TRF7970A_ST_WAIT_FOR_RX_DATA:
+ case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
+ if (status & TRF7970A_IRQ_STATUS_SRX) {
+ trf->ignore_timeout =
+ !cancel_delayed_work(&trf->timeout_work);
+ trf7970a_drain_fifo(trf, status);
+ } else if (status & TRF7970A_IRQ_STATUS_FIFO) {
+ ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS,
+ &fifo_bytes);
+
+ fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
+
+ if (ret)
+ trf7970a_send_err_upstream(trf, ret);
+ else if (!fifo_bytes)
+ trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
+ } else if ((status == TRF7970A_IRQ_STATUS_TX) ||
+ (!trf->is_initiator &&
+ (status == (TRF7970A_IRQ_STATUS_TX |
+ TRF7970A_IRQ_STATUS_NFC_RF)))) {
+ trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
+
+ if (!trf->timeout) {
+ trf->ignore_timeout = !cancel_delayed_work(
+ &trf->timeout_work);
+ trf->rx_skb = ERR_PTR(0);
+ trf7970a_send_upstream(trf);
+ break;
+ }
+
+ if (trf->is_initiator)
+ break;
+
+ iso_ctrl = trf->iso_ctrl;
+
+ switch (trf->framing) {
+ case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
+ trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
+ iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
+ trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
+ break;
+ case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
+ trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
+ iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
+ trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
+ break;
+ case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
+ ret = trf7970a_write(trf,
+ TRF7970A_SPECIAL_FCN_REG1,
+ TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL);
+ if (ret)
+ goto err_unlock_exit;
+
+ trf->special_fcn_reg1 =
+ TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL;
+ break;
+ default:
+ break;
+ }
+
+ if (iso_ctrl != trf->iso_ctrl) {
+ ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
+ iso_ctrl);
+ if (ret)
+ goto err_unlock_exit;
+
+ trf->iso_ctrl = iso_ctrl;
+ }
+ } else {
+ trf7970a_send_err_upstream(trf, -EIO);
+ }
+ break;
+ case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
+ if (status != TRF7970A_IRQ_STATUS_TX)
+ trf7970a_send_err_upstream(trf, -EIO);
+ break;
+ case TRF7970A_ST_LISTENING:
+ if (status & TRF7970A_IRQ_STATUS_SRX) {
+ trf->ignore_timeout =
+ !cancel_delayed_work(&trf->timeout_work);
+ trf7970a_drain_fifo(trf, status);
+ } else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
+ trf7970a_send_err_upstream(trf, -EIO);
+ }
+ break;
+ case TRF7970A_ST_LISTENING_MD:
+ if (status & TRF7970A_IRQ_STATUS_SRX) {
+ trf->ignore_timeout =
+ !cancel_delayed_work(&trf->timeout_work);
+
+ ret = trf7970a_mode_detect(trf, &trf->md_rf_tech);
+ if (ret) {
+ trf7970a_send_err_upstream(trf, ret);
+ } else {
+ trf->state = TRF7970A_ST_LISTENING;
+ trf7970a_drain_fifo(trf, status);
+ }
+ } else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
+ trf7970a_send_err_upstream(trf, -EIO);
+ }
+ break;
+ default:
+ dev_err(trf->dev, "%s - Driver in invalid state: %d\n",
+ __func__, trf->state);
+ }
+
+err_unlock_exit:
+ mutex_unlock(&trf->lock);
+ return IRQ_HANDLED;
+}
+
+static void trf7970a_issue_eof(struct trf7970a *trf)
+{
+ int ret;
+
+ dev_dbg(trf->dev, "Issuing EOF\n");
+
+ ret = trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
+ if (ret)
+ trf7970a_send_err_upstream(trf, ret);
+
+ ret = trf7970a_cmd(trf, TRF7970A_CMD_EOF);
+ if (ret)
+ trf7970a_send_err_upstream(trf, ret);
+
+ trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
+
+ dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n",
+ trf->timeout, trf->state);
+
+ schedule_delayed_work(&trf->timeout_work,
+ msecs_to_jiffies(trf->timeout));
+}
+
+static void trf7970a_timeout_work_handler(struct work_struct *work)
+{
+ struct trf7970a *trf = container_of(work, struct trf7970a,
+ timeout_work.work);
+
+ dev_dbg(trf->dev, "Timeout - state: %d, ignore_timeout: %d\n",
+ trf->state, trf->ignore_timeout);
+
+ mutex_lock(&trf->lock);
+
+ if (trf->ignore_timeout)
+ trf->ignore_timeout = false;
+ else if (trf->state == TRF7970A_ST_WAIT_FOR_RX_DATA_CONT)
+ trf7970a_drain_fifo(trf, TRF7970A_IRQ_STATUS_SRX);
+ else if (trf->state == TRF7970A_ST_WAIT_TO_ISSUE_EOF)
+ trf7970a_issue_eof(trf);
+ else
+ trf7970a_send_err_upstream(trf, -ETIMEDOUT);
+
+ mutex_unlock(&trf->lock);
+}
+
+static int trf7970a_init(struct trf7970a *trf)
+{
+ int ret;
+
+ dev_dbg(trf->dev, "Initializing device - state: %d\n", trf->state);
+
+ ret = trf7970a_cmd(trf, TRF7970A_CMD_SOFT_INIT);
+ if (ret)
+ goto err_out;
+
+ ret = trf7970a_cmd(trf, TRF7970A_CMD_IDLE);
+ if (ret)
+ goto err_out;
+
+ usleep_range(1000, 2000);
+
+ trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
+
+ ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL, 0);
+ if (ret)
+ goto err_out;
+
+ trf->modulator_sys_clk_ctrl = 0;
+
+ ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS,
+ TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 |
+ TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32);
+ if (ret)
+ goto err_out;
+
+ ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1, 0);
+ if (ret)
+ goto err_out;
+
+ trf->special_fcn_reg1 = 0;
+
+ trf->iso_ctrl = 0xff;
+ return 0;
+
+err_out:
+ dev_dbg(trf->dev, "Couldn't init device: %d\n", ret);
+ return ret;
+}
+
+static void trf7970a_switch_rf_off(struct trf7970a *trf)
+{
+ if ((trf->state == TRF7970A_ST_PWR_OFF) ||
+ (trf->state == TRF7970A_ST_RF_OFF))
+ return;
+
+ dev_dbg(trf->dev, "Switching rf off\n");
+
+ trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
+
+ trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, trf->chip_status_ctrl);
+
+ trf->aborting = false;
+ trf->state = TRF7970A_ST_RF_OFF;
+
+ pm_runtime_mark_last_busy(trf->dev);
+ pm_runtime_put_autosuspend(trf->dev);
+}
+
+static int trf7970a_switch_rf_on(struct trf7970a *trf)
+{
+ int ret;
+
+ dev_dbg(trf->dev, "Switching rf on\n");
+
+ pm_runtime_get_sync(trf->dev);
+
+ if (trf->state != TRF7970A_ST_RF_OFF) { /* Power on, RF off */
+ dev_err(trf->dev, "%s - Incorrect state: %d\n", __func__,
+ trf->state);
+ return -EINVAL;
+ }
+
+ ret = trf7970a_init(trf);
+ if (ret) {
+ dev_err(trf->dev, "%s - Can't initialize: %d\n", __func__, ret);
+ return ret;
+ }
+
+ trf->state = TRF7970A_ST_IDLE;
+
+ return 0;
+}
+
+static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on)
+{
+ struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
+ int ret = 0;
+
+ dev_dbg(trf->dev, "Switching RF - state: %d, on: %d\n", trf->state, on);
+
+ mutex_lock(&trf->lock);
+
+ if (on) {
+ switch (trf->state) {
+ case TRF7970A_ST_PWR_OFF:
+ case TRF7970A_ST_RF_OFF:
+ ret = trf7970a_switch_rf_on(trf);
+ break;
+ case TRF7970A_ST_IDLE:
+ case TRF7970A_ST_IDLE_RX_BLOCKED:
+ break;
+ default:
+ dev_err(trf->dev, "%s - Invalid request: %d %d\n",
+ __func__, trf->state, on);
+ trf7970a_switch_rf_off(trf);
+ ret = -EINVAL;
+ }
+ } else {
+ switch (trf->state) {
+ case TRF7970A_ST_PWR_OFF:
+ case TRF7970A_ST_RF_OFF:
+ break;
+ default:
+ dev_err(trf->dev, "%s - Invalid request: %d %d\n",
+ __func__, trf->state, on);
+ ret = -EINVAL;
+ /* FALLTHROUGH */
+ case TRF7970A_ST_IDLE:
+ case TRF7970A_ST_IDLE_RX_BLOCKED:
+ case TRF7970A_ST_WAIT_FOR_RX_DATA:
+ case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
+ trf7970a_switch_rf_off(trf);
+ }
+ }
+
+ mutex_unlock(&trf->lock);
+ return ret;
+}
+
+static int trf7970a_in_config_rf_tech(struct trf7970a *trf, int tech)
+{
+ int ret = 0;
+
+ dev_dbg(trf->dev, "rf technology: %d\n", tech);
+
+ switch (tech) {
+ case NFC_DIGITAL_RF_TECH_106A:
+ trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443A_106;
+ trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_OOK;
+ trf->guard_time = TRF7970A_GUARD_TIME_NFCA;
+ break;
+ case NFC_DIGITAL_RF_TECH_106B:
+ trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443B_106;
+ trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10;
+ trf->guard_time = TRF7970A_GUARD_TIME_NFCB;
+ break;
+ case NFC_DIGITAL_RF_TECH_212F:
+ trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_212;
+ trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10;
+ trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
+ break;
+ case NFC_DIGITAL_RF_TECH_424F:
+ trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_424;
+ trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10;
+ trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
+ break;
+ case NFC_DIGITAL_RF_TECH_ISO15693:
+ trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
+ trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_OOK;
+ trf->guard_time = TRF7970A_GUARD_TIME_15693;
+ break;
+ default:
+ dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
+ return -EINVAL;
+ }
+
+ trf->technology = tech;
+
+ /* If in initiator mode and not changing the RF tech due to a
+ * PSL sequence (indicated by 'trf->iso_ctrl == 0xff' from
+ * trf7970a_init()), clear the NFC Target Detection Level register
+ * due to erratum.
+ */
+ if (trf->iso_ctrl == 0xff)
+ ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
+
+ return ret;
+}
+
+static int trf7970a_is_rf_field(struct trf7970a *trf, bool *is_rf_field)
+{
+ int ret;
+ u8 rssi;
+
+ ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
+ trf->chip_status_ctrl | TRF7970A_CHIP_STATUS_REC_ON);
+ if (ret)
+ return ret;
+
+ ret = trf7970a_cmd(trf, TRF7970A_CMD_TEST_EXT_RF);
+ if (ret)
+ return ret;
+
+ usleep_range(50, 60);
+
+ ret = trf7970a_read(trf, TRF7970A_RSSI_OSC_STATUS, &rssi);
+ if (ret)
+ return ret;
+
+ ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
+ trf->chip_status_ctrl);
+ if (ret)
+ return ret;
+
+ if (rssi & TRF7970A_RSSI_OSC_STATUS_RSSI_MASK)
+ *is_rf_field = true;
+ else
+ *is_rf_field = false;
+
+ return 0;
+}
+
+static int trf7970a_in_config_framing(struct trf7970a *trf, int framing)
+{
+ u8 iso_ctrl = trf->iso_ctrl_tech;
+ bool is_rf_field = false;
+ int ret;
+
+ dev_dbg(trf->dev, "framing: %d\n", framing);
+
+ switch (framing) {
+ case NFC_DIGITAL_FRAMING_NFCA_SHORT:
+ case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
+ trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
+ iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
+ break;
+ case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
+ case NFC_DIGITAL_FRAMING_NFCA_T4T:
+ case NFC_DIGITAL_FRAMING_NFCB:
+ case NFC_DIGITAL_FRAMING_NFCB_T4T:
+ case NFC_DIGITAL_FRAMING_NFCF:
+ case NFC_DIGITAL_FRAMING_NFCF_T3T:
+ case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY:
+ case NFC_DIGITAL_FRAMING_ISO15693_T5T:
+ case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
+ case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
+ trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
+ iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
+ break;
+ case NFC_DIGITAL_FRAMING_NFCA_T2T:
+ trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
+ iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
+ break;
+ default:
+ dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
+ return -EINVAL;
+ }
+
+ trf->framing = framing;
+
+ if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
+ ret = trf7970a_is_rf_field(trf, &is_rf_field);
+ if (ret)
+ return ret;
+
+ if (is_rf_field)
+ return -EBUSY;
+ }
+
+ if (iso_ctrl != trf->iso_ctrl) {
+ ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
+ if (ret)
+ return ret;
+
+ trf->iso_ctrl = iso_ctrl;
+
+ ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
+ trf->modulator_sys_clk_ctrl);
+ if (ret)
+ return ret;
+ }
+
+ if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
+ ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
+ trf->chip_status_ctrl |
+ TRF7970A_CHIP_STATUS_RF_ON);
+ if (ret)
+ return ret;
+
+ trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
+
+ usleep_range(trf->guard_time, trf->guard_time + 1000);
+ }
+
+ return 0;
+}
+
+static int trf7970a_in_configure_hw(struct nfc_digital_dev *ddev, int type,
+ int param)
+{
+ struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
+ int ret;
+
+ dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
+
+ mutex_lock(&trf->lock);
+
+ trf->is_initiator = true;
+
+ if ((trf->state == TRF7970A_ST_PWR_OFF) ||
+ (trf->state == TRF7970A_ST_RF_OFF)) {
+ ret = trf7970a_switch_rf_on(trf);
+ if (ret)
+ goto err_unlock;
+ }
+
+ switch (type) {
+ case NFC_DIGITAL_CONFIG_RF_TECH:
+ ret = trf7970a_in_config_rf_tech(trf, param);
+ break;
+ case NFC_DIGITAL_CONFIG_FRAMING:
+ ret = trf7970a_in_config_framing(trf, param);
+ break;
+ default:
+ dev_dbg(trf->dev, "Unknown type: %d\n", type);
+ ret = -EINVAL;
+ }
+
+err_unlock:
+ mutex_unlock(&trf->lock);
+ return ret;
+}
+
+static int trf7970a_is_iso15693_write_or_lock(u8 cmd)
+{
+ switch (cmd) {
+ case ISO15693_CMD_WRITE_SINGLE_BLOCK:
+ case ISO15693_CMD_LOCK_BLOCK:
+ case ISO15693_CMD_WRITE_MULTIPLE_BLOCK:
+ case ISO15693_CMD_WRITE_AFI:
+ case ISO15693_CMD_LOCK_AFI:
+ case ISO15693_CMD_WRITE_DSFID:
+ case ISO15693_CMD_LOCK_DSFID:
+ return 1;
+ break;
+ default:
+ return 0;
+ }
+}
+
+static int trf7970a_per_cmd_config(struct trf7970a *trf, struct sk_buff *skb)
+{
+ u8 *req = skb->data;
+ u8 special_fcn_reg1, iso_ctrl;
+ int ret;
+
+ trf->issue_eof = false;
+
+ /* When issuing Type 2 read command, make sure the '4_bit_RX' bit in
+ * special functions register 1 is cleared; otherwise, its a write or
+ * sector select command and '4_bit_RX' must be set.
+ *
+ * When issuing an ISO 15693 command, inspect the flags byte to see
+ * what speed to use. Also, remember if the OPTION flag is set on
+ * a Type 5 write or lock command so the driver will know that it
+ * has to send an EOF in order to get a response.
+ */
+ if ((trf->technology == NFC_DIGITAL_RF_TECH_106A) &&
+ (trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T)) {
+ if (req[0] == NFC_T2T_CMD_READ)
+ special_fcn_reg1 = 0;
+ else
+ special_fcn_reg1 = TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX;
+
+ if (special_fcn_reg1 != trf->special_fcn_reg1) {
+ ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1,
+ special_fcn_reg1);
+ if (ret)
+ return ret;
+
+ trf->special_fcn_reg1 = special_fcn_reg1;
+ }
+ } else if (trf->technology == NFC_DIGITAL_RF_TECH_ISO15693) {
+ iso_ctrl = trf->iso_ctrl & ~TRF7970A_ISO_CTRL_RFID_SPEED_MASK;
+
+ switch (req[0] & ISO15693_REQ_FLAG_SPEED_MASK) {
+ case 0x00:
+ iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_662;
+ break;
+ case ISO15693_REQ_FLAG_SUB_CARRIER:
+ iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a;
+ break;
+ case ISO15693_REQ_FLAG_DATA_RATE:
+ iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
+ break;
+ case (ISO15693_REQ_FLAG_SUB_CARRIER |
+ ISO15693_REQ_FLAG_DATA_RATE):
+ iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669;
+ break;
+ }
+
+ if (iso_ctrl != trf->iso_ctrl) {
+ ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
+ if (ret)
+ return ret;
+
+ trf->iso_ctrl = iso_ctrl;
+ }
+
+ if ((trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) &&
+ trf7970a_is_iso15693_write_or_lock(req[1]) &&
+ (req[0] & ISO15693_REQ_FLAG_OPTION))
+ trf->issue_eof = true;
+ }
+
+ return 0;
+}
+
+static int trf7970a_send_cmd(struct nfc_digital_dev *ddev,
+ struct sk_buff *skb, u16 timeout,
+ nfc_digital_cmd_complete_t cb, void *arg)
+{
+ struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
+ u8 prefix[5];
+ unsigned int len;
+ int ret;
+ u8 status;
+
+ dev_dbg(trf->dev, "New request - state: %d, timeout: %d ms, len: %d\n",
+ trf->state, timeout, skb->len);
+
+ if (skb->len > TRF7970A_TX_MAX)
+ return -EINVAL;
+
+ mutex_lock(&trf->lock);
+
+ if ((trf->state != TRF7970A_ST_IDLE) &&
+ (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
+ dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
+ trf->state);
+ ret = -EIO;
+ goto out_err;
+ }
+
+ if (trf->aborting) {
+ dev_dbg(trf->dev, "Abort process complete\n");
+ trf->aborting = false;
+ ret = -ECANCELED;
+ goto out_err;
+ }
+
+ if (timeout) {
+ trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
+ GFP_KERNEL);
+ if (!trf->rx_skb) {
+ dev_dbg(trf->dev, "Can't alloc rx_skb\n");
+ ret = -ENOMEM;
+ goto out_err;
+ }
+ }
+
+ if (trf->state == TRF7970A_ST_IDLE_RX_BLOCKED) {
+ ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
+ if (ret)
+ goto out_err;
+
+ trf->state = TRF7970A_ST_IDLE;
+ }
+
+ if (trf->is_initiator) {
+ ret = trf7970a_per_cmd_config(trf, skb);
+ if (ret)
+ goto out_err;
+ }
+
+ trf->ddev = ddev;
+ trf->tx_skb = skb;
+ trf->cb = cb;
+ trf->cb_arg = arg;
+ trf->timeout = timeout;
+ trf->ignore_timeout = false;
+
+ len = skb->len;
+
+ /* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
+ * on what the current framing is, the address of the TX length byte 1
+ * register (0x1d), and the 2 byte length of the data to be transmitted.
+ * That totals 5 bytes.
+ */
+ prefix[0] = TRF7970A_CMD_BIT_CTRL |
+ TRF7970A_CMD_BIT_OPCODE(TRF7970A_CMD_FIFO_RESET);
+ prefix[1] = TRF7970A_CMD_BIT_CTRL |
+ TRF7970A_CMD_BIT_OPCODE(trf->tx_cmd);
+ prefix[2] = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_TX_LENGTH_BYTE1;
+
+ if (trf->framing == NFC_DIGITAL_FRAMING_NFCA_SHORT) {
+ prefix[3] = 0x00;
+ prefix[4] = 0x0f; /* 7 bits */
+ } else {
+ prefix[3] = (len & 0xf00) >> 4;
+ prefix[3] |= ((len & 0xf0) >> 4);
+ prefix[4] = ((len & 0x0f) << 4);
+ }
+
+ len = min_t(int, skb->len, TRF7970A_FIFO_SIZE);
+
+ /* Clear possible spurious interrupt */
+ ret = trf7970a_read_irqstatus(trf, &status);
+ if (ret)
+ goto out_err;
+
+ ret = trf7970a_transmit(trf, skb, len, prefix, sizeof(prefix));
+ if (ret) {
+ kfree_skb(trf->rx_skb);
+ trf->rx_skb = NULL;
+ }
+
+out_err:
+ mutex_unlock(&trf->lock);
+ return ret;
+}
+
+static int trf7970a_tg_config_rf_tech(struct trf7970a *trf, int tech)
+{
+ int ret = 0;
+
+ dev_dbg(trf->dev, "rf technology: %d\n", tech);
+
+ switch (tech) {
+ case NFC_DIGITAL_RF_TECH_106A:
+ trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
+ TRF7970A_ISO_CTRL_NFC_CE |
+ TRF7970A_ISO_CTRL_NFC_CE_14443A;
+ trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_OOK;
+ break;
+ case NFC_DIGITAL_RF_TECH_212F:
+ trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
+ TRF7970A_ISO_CTRL_NFC_NFCF_212;
+ trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10;
+ break;
+ case NFC_DIGITAL_RF_TECH_424F:
+ trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
+ TRF7970A_ISO_CTRL_NFC_NFCF_424;
+ trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10;
+ break;
+ default:
+ dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
+ return -EINVAL;
+ }
+
+ trf->technology = tech;
+
+ /* Normally we write the ISO_CTRL register in
+ * trf7970a_tg_config_framing() because the framing can change
+ * the value written. However, when sending a PSL RES,
+ * digital_tg_send_psl_res_complete() doesn't call
+ * trf7970a_tg_config_framing() so we must write the register
+ * here.
+ */
+ if ((trf->framing == NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED) &&
+ (trf->iso_ctrl_tech != trf->iso_ctrl)) {
+ ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
+ trf->iso_ctrl_tech);
+
+ trf->iso_ctrl = trf->iso_ctrl_tech;
+ }
+
+ return ret;
+}
+
+/* Since this is a target routine, several of the framing calls are
+ * made between receiving the request and sending the response so they
+ * should take effect until after the response is sent. This is accomplished
+ * by skipping the ISO_CTRL register write here and doing it in the interrupt
+ * handler.
+ */
+static int trf7970a_tg_config_framing(struct trf7970a *trf, int framing)
+{
+ u8 iso_ctrl = trf->iso_ctrl_tech;
+ int ret;
+
+ dev_dbg(trf->dev, "framing: %d\n", framing);
+
+ switch (framing) {
+ case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
+ trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
+ iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
+ break;
+ case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
+ case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
+ case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
+ /* These ones are applied in the interrupt handler */
+ iso_ctrl = trf->iso_ctrl; /* Don't write to ISO_CTRL yet */
+ break;
+ case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
+ trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
+ iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
+ break;
+ case NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED:
+ trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
+ iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
+ break;
+ default:
+ dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
+ return -EINVAL;
+ }
+
+ trf->framing = framing;
+
+ if (iso_ctrl != trf->iso_ctrl) {
+ ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
+ if (ret)
+ return ret;
+
+ trf->iso_ctrl = iso_ctrl;
+
+ ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
+ trf->modulator_sys_clk_ctrl);
+ if (ret)
+ return ret;
+ }
+
+ if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
+ ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
+ trf->chip_status_ctrl |
+ TRF7970A_CHIP_STATUS_RF_ON);
+ if (ret)
+ return ret;
+
+ trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
+ }
+
+ return 0;
+}
+
+static int trf7970a_tg_configure_hw(struct nfc_digital_dev *ddev, int type,
+ int param)
+{
+ struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
+ int ret;
+
+ dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
+
+ mutex_lock(&trf->lock);
+
+ trf->is_initiator = false;
+
+ if ((trf->state == TRF7970A_ST_PWR_OFF) ||
+ (trf->state == TRF7970A_ST_RF_OFF)) {
+ ret = trf7970a_switch_rf_on(trf);
+ if (ret)
+ goto err_unlock;
+ }
+
+ switch (type) {
+ case NFC_DIGITAL_CONFIG_RF_TECH:
+ ret = trf7970a_tg_config_rf_tech(trf, param);
+ break;
+ case NFC_DIGITAL_CONFIG_FRAMING:
+ ret = trf7970a_tg_config_framing(trf, param);
+ break;
+ default:
+ dev_dbg(trf->dev, "Unknown type: %d\n", type);
+ ret = -EINVAL;
+ }
+
+err_unlock:
+ mutex_unlock(&trf->lock);
+ return ret;
+}
+
+static int _trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
+ nfc_digital_cmd_complete_t cb, void *arg, bool mode_detect)
+{
+ struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
+ int ret;
+
+ mutex_lock(&trf->lock);
+
+ if ((trf->state != TRF7970A_ST_IDLE) &&
+ (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
+ dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
+ trf->state);
+ ret = -EIO;
+ goto out_err;
+ }
+
+ if (trf->aborting) {
+ dev_dbg(trf->dev, "Abort process complete\n");
+ trf->aborting = false;
+ ret = -ECANCELED;
+ goto out_err;
+ }
+
+ trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
+ GFP_KERNEL);
+ if (!trf->rx_skb) {
+ dev_dbg(trf->dev, "Can't alloc rx_skb\n");
+ ret = -ENOMEM;
+ goto out_err;
+ }
+
+ ret = trf7970a_write(trf, TRF7970A_RX_SPECIAL_SETTINGS,
+ TRF7970A_RX_SPECIAL_SETTINGS_HBT |
+ TRF7970A_RX_SPECIAL_SETTINGS_M848 |
+ TRF7970A_RX_SPECIAL_SETTINGS_C424 |
+ TRF7970A_RX_SPECIAL_SETTINGS_C212);
+ if (ret)
+ goto out_err;
+
+ ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
+ TRF7970A_REG_IO_CTRL_VRS(0x1));
+ if (ret)
+ goto out_err;
+
+ ret = trf7970a_write(trf, TRF7970A_NFC_LOW_FIELD_LEVEL,
+ TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(0x3));
+ if (ret)
+ goto out_err;
+
+ ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL,
+ TRF7970A_NFC_TARGET_LEVEL_RFDET(0x7));
+ if (ret)
+ goto out_err;
+
+ trf->ddev = ddev;
+ trf->cb = cb;
+ trf->cb_arg = arg;
+ trf->timeout = timeout;
+ trf->ignore_timeout = false;
+
+ ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
+ if (ret)
+ goto out_err;
+
+ trf->state = mode_detect ? TRF7970A_ST_LISTENING_MD :
+ TRF7970A_ST_LISTENING;
+
+ schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
+
+out_err:
+ mutex_unlock(&trf->lock);
+ return ret;
+}
+
+static int trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
+ nfc_digital_cmd_complete_t cb, void *arg)
+{
+ struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
+
+ dev_dbg(trf->dev, "Listen - state: %d, timeout: %d ms\n",
+ trf->state, timeout);
+
+ return _trf7970a_tg_listen(ddev, timeout, cb, arg, false);
+}
+
+static int trf7970a_tg_listen_md(struct nfc_digital_dev *ddev,
+ u16 timeout, nfc_digital_cmd_complete_t cb, void *arg)
+{
+ struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
+ int ret;
+
+ dev_dbg(trf->dev, "Listen MD - state: %d, timeout: %d ms\n",
+ trf->state, timeout);
+
+ ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
+ NFC_DIGITAL_RF_TECH_106A);
+ if (ret)
+ return ret;
+
+ ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
+ NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
+ if (ret)
+ return ret;
+
+ return _trf7970a_tg_listen(ddev, timeout, cb, arg, true);
+}
+
+static int trf7970a_tg_get_rf_tech(struct nfc_digital_dev *ddev, u8 *rf_tech)
+{
+ struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
+
+ dev_dbg(trf->dev, "Get RF Tech - state: %d, rf_tech: %d\n",
+ trf->state, trf->md_rf_tech);
+
+ *rf_tech = trf->md_rf_tech;
+
+ return 0;
+}
+
+static void trf7970a_abort_cmd(struct nfc_digital_dev *ddev)
+{
+ struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
+
+ dev_dbg(trf->dev, "Abort process initiated\n");
+
+ mutex_lock(&trf->lock);
+
+ switch (trf->state) {
+ case TRF7970A_ST_WAIT_FOR_TX_FIFO:
+ case TRF7970A_ST_WAIT_FOR_RX_DATA:
+ case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
+ case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
+ trf->aborting = true;
+ break;
+ case TRF7970A_ST_LISTENING:
+ trf->ignore_timeout = !cancel_delayed_work(&trf->timeout_work);
+ trf7970a_send_err_upstream(trf, -ECANCELED);
+ dev_dbg(trf->dev, "Abort process complete\n");
+ break;
+ default:
+ break;
+ }
+
+ mutex_unlock(&trf->lock);
+}
+
+static struct nfc_digital_ops trf7970a_nfc_ops = {
+ .in_configure_hw = trf7970a_in_configure_hw,
+ .in_send_cmd = trf7970a_send_cmd,
+ .tg_configure_hw = trf7970a_tg_configure_hw,
+ .tg_send_cmd = trf7970a_send_cmd,
+ .tg_listen = trf7970a_tg_listen,
+ .tg_listen_md = trf7970a_tg_listen_md,
+ .tg_get_rf_tech = trf7970a_tg_get_rf_tech,
+ .switch_rf = trf7970a_switch_rf,
+ .abort_cmd = trf7970a_abort_cmd,
+};
+
+static int trf7970a_power_up(struct trf7970a *trf)
+{
+ int ret;
+
+ dev_dbg(trf->dev, "Powering up - state: %d\n", trf->state);
+
+ if (trf->state != TRF7970A_ST_PWR_OFF)
+ return 0;
+
+ ret = regulator_enable(trf->regulator);
+ if (ret) {
+ dev_err(trf->dev, "%s - Can't enable VIN: %d\n", __func__, ret);
+ return ret;
+ }
+
+ usleep_range(5000, 6000);
+
+ if (!(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW)) {
+ gpio_set_value(trf->en2_gpio, 1);
+ usleep_range(1000, 2000);
+ }
+
+ gpio_set_value(trf->en_gpio, 1);
+
+ usleep_range(20000, 21000);
+
+ trf->state = TRF7970A_ST_RF_OFF;
+
+ return 0;
+}
+
+static int trf7970a_power_down(struct trf7970a *trf)
+{
+ int ret;
+
+ dev_dbg(trf->dev, "Powering down - state: %d\n", trf->state);
+
+ if (trf->state == TRF7970A_ST_PWR_OFF)
+ return 0;
+
+ if (trf->state != TRF7970A_ST_RF_OFF) {
+ dev_dbg(trf->dev, "Can't power down - not RF_OFF state (%d)\n",
+ trf->state);
+ return -EBUSY;
+ }
+
+ gpio_set_value(trf->en_gpio, 0);
+ gpio_set_value(trf->en2_gpio, 0);
+
+ ret = regulator_disable(trf->regulator);
+ if (ret)
+ dev_err(trf->dev, "%s - Can't disable VIN: %d\n", __func__,
+ ret);
+
+ trf->state = TRF7970A_ST_PWR_OFF;
+
+ return ret;
+}
+
+static int trf7970a_startup(struct trf7970a *trf)
+{
+ int ret;
+
+ ret = trf7970a_power_up(trf);
+ if (ret)
+ return ret;
+
+ pm_runtime_set_active(trf->dev);
+ pm_runtime_enable(trf->dev);
+ pm_runtime_mark_last_busy(trf->dev);
+
+ return 0;
+}
+
+static void trf7970a_shutdown(struct trf7970a *trf)
+{
+ switch (trf->state) {
+ case TRF7970A_ST_WAIT_FOR_TX_FIFO:
+ case TRF7970A_ST_WAIT_FOR_RX_DATA:
+ case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
+ case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
+ case TRF7970A_ST_LISTENING:
+ trf7970a_send_err_upstream(trf, -ECANCELED);
+ /* FALLTHROUGH */
+ case TRF7970A_ST_IDLE:
+ case TRF7970A_ST_IDLE_RX_BLOCKED:
+ trf7970a_switch_rf_off(trf);
+ break;
+ default:
+ break;
+ }
+
+ pm_runtime_disable(trf->dev);
+ pm_runtime_set_suspended(trf->dev);
+
+ trf7970a_power_down(trf);
+}
+
+static int trf7970a_get_autosuspend_delay(struct device_node *np)
+{
+ int autosuspend_delay, ret;
+
+ ret = of_property_read_u32(np, "autosuspend-delay", &autosuspend_delay);
+ if (ret)
+ autosuspend_delay = TRF7970A_AUTOSUSPEND_DELAY;
+
+ return autosuspend_delay;
+}
+
+static int trf7970a_get_vin_voltage_override(struct device_node *np,
+ u32 *vin_uvolts)
+{
+ return of_property_read_u32(np, "vin-voltage-override", vin_uvolts);
+}
+
+static int trf7970a_probe(struct spi_device *spi)
+{
+ struct device_node *np = spi->dev.of_node;
+ struct trf7970a *trf;
+ int uvolts, autosuspend_delay, ret;
+
+ if (!np) {
+ dev_err(&spi->dev, "No Device Tree entry\n");
+ return -EINVAL;
+ }
+
+ trf = devm_kzalloc(&spi->dev, sizeof(*trf), GFP_KERNEL);
+ if (!trf)
+ return -ENOMEM;
+
+ trf->state = TRF7970A_ST_PWR_OFF;
+ trf->dev = &spi->dev;
+ trf->spi = spi;
+
+ spi->mode = SPI_MODE_1;
+ spi->bits_per_word = 8;
+
+ ret = spi_setup(spi);
+ if (ret < 0) {
+ dev_err(trf->dev, "Can't set up SPI Communication\n");
+ return ret;
+ }
+
+ if (of_property_read_bool(np, "irq-status-read-quirk"))
+ trf->quirks |= TRF7970A_QUIRK_IRQ_STATUS_READ;
+
+ /* There are two enable pins - both must be present */
+ trf->en_gpio = of_get_named_gpio(np, "ti,enable-gpios", 0);
+ if (!gpio_is_valid(trf->en_gpio)) {
+ dev_err(trf->dev, "No EN GPIO property\n");
+ return trf->en_gpio;
+ }
+
+ ret = devm_gpio_request_one(trf->dev, trf->en_gpio,
+ GPIOF_DIR_OUT | GPIOF_INIT_LOW, "trf7970a EN");
+ if (ret) {
+ dev_err(trf->dev, "Can't request EN GPIO: %d\n", ret);
+ return ret;
+ }
+
+ trf->en2_gpio = of_get_named_gpio(np, "ti,enable-gpios", 1);
+ if (!gpio_is_valid(trf->en2_gpio)) {
+ dev_err(trf->dev, "No EN2 GPIO property\n");
+ return trf->en2_gpio;
+ }
+
+ ret = devm_gpio_request_one(trf->dev, trf->en2_gpio,
+ GPIOF_DIR_OUT | GPIOF_INIT_LOW, "trf7970a EN2");
+ if (ret) {
+ dev_err(trf->dev, "Can't request EN2 GPIO: %d\n", ret);
+ return ret;
+ }
+
+ if (of_property_read_bool(np, "en2-rf-quirk"))
+ trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;
+
+ ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL,
+ trf7970a_irq, IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+ "trf7970a", trf);
+ if (ret) {
+ dev_err(trf->dev, "Can't request IRQ#%d: %d\n", spi->irq, ret);
+ return ret;
+ }
+
+ mutex_init(&trf->lock);
+ INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
+
+ trf->regulator = devm_regulator_get(&spi->dev, "vin");
+ if (IS_ERR(trf->regulator)) {
+ ret = PTR_ERR(trf->regulator);
+ dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret);
+ goto err_destroy_lock;
+ }
+
+ ret = regulator_enable(trf->regulator);
+ if (ret) {
+ dev_err(trf->dev, "Can't enable VIN: %d\n", ret);
+ goto err_destroy_lock;
+ }
+
+ ret = trf7970a_get_vin_voltage_override(np, &uvolts);
+ if (ret)
+ uvolts = regulator_get_voltage(trf->regulator);
+
+ if (uvolts > 4000000)
+ trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;
+
+ trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,
+ TRF7970A_SUPPORTED_PROTOCOLS,
+ NFC_DIGITAL_DRV_CAPS_IN_CRC |
+ NFC_DIGITAL_DRV_CAPS_TG_CRC, 0, 0);
+ if (!trf->ddev) {
+ dev_err(trf->dev, "Can't allocate NFC digital device\n");
+ ret = -ENOMEM;
+ goto err_disable_regulator;
+ }
+
+ nfc_digital_set_parent_dev(trf->ddev, trf->dev);
+ nfc_digital_set_drvdata(trf->ddev, trf);
+ spi_set_drvdata(spi, trf);
+
+ autosuspend_delay = trf7970a_get_autosuspend_delay(np);
+
+ pm_runtime_set_autosuspend_delay(trf->dev, autosuspend_delay);
+ pm_runtime_use_autosuspend(trf->dev);
+
+ ret = trf7970a_startup(trf);
+ if (ret)
+ goto err_free_ddev;
+
+ ret = nfc_digital_register_device(trf->ddev);
+ if (ret) {
+ dev_err(trf->dev, "Can't register NFC digital device: %d\n",
+ ret);
+ goto err_shutdown;
+ }
+
+ return 0;
+
+err_shutdown:
+ trf7970a_shutdown(trf);
+err_free_ddev:
+ nfc_digital_free_device(trf->ddev);
+err_disable_regulator:
+ regulator_disable(trf->regulator);
+err_destroy_lock:
+ mutex_destroy(&trf->lock);
+ return ret;
+}
+
+static int trf7970a_remove(struct spi_device *spi)
+{
+ struct trf7970a *trf = spi_get_drvdata(spi);
+
+ mutex_lock(&trf->lock);
+
+ trf7970a_shutdown(trf);
+
+ mutex_unlock(&trf->lock);
+
+ nfc_digital_unregister_device(trf->ddev);
+ nfc_digital_free_device(trf->ddev);
+
+ regulator_disable(trf->regulator);
+
+ mutex_destroy(&trf->lock);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int trf7970a_suspend(struct device *dev)
+{
+ struct spi_device *spi = container_of(dev, struct spi_device, dev);
+ struct trf7970a *trf = spi_get_drvdata(spi);
+
+ dev_dbg(dev, "Suspend\n");
+
+ mutex_lock(&trf->lock);
+
+ trf7970a_shutdown(trf);
+
+ mutex_unlock(&trf->lock);
+
+ return 0;
+}
+
+static int trf7970a_resume(struct device *dev)
+{
+ struct spi_device *spi = container_of(dev, struct spi_device, dev);
+ struct trf7970a *trf = spi_get_drvdata(spi);
+ int ret;
+
+ dev_dbg(dev, "Resume\n");
+
+ mutex_lock(&trf->lock);
+
+ ret = trf7970a_startup(trf);
+
+ mutex_unlock(&trf->lock);
+
+ return ret;
+}
+#endif
+
+#ifdef CONFIG_PM
+static int trf7970a_pm_runtime_suspend(struct device *dev)
+{
+ struct spi_device *spi = container_of(dev, struct spi_device, dev);
+ struct trf7970a *trf = spi_get_drvdata(spi);
+ int ret;
+
+ dev_dbg(dev, "Runtime suspend\n");
+
+ mutex_lock(&trf->lock);
+
+ ret = trf7970a_power_down(trf);
+
+ mutex_unlock(&trf->lock);
+
+ return ret;
+}
+
+static int trf7970a_pm_runtime_resume(struct device *dev)
+{
+ struct spi_device *spi = container_of(dev, struct spi_device, dev);
+ struct trf7970a *trf = spi_get_drvdata(spi);
+ int ret;
+
+ dev_dbg(dev, "Runtime resume\n");
+
+ ret = trf7970a_power_up(trf);
+ if (!ret)
+ pm_runtime_mark_last_busy(dev);
+
+ return ret;
+}
+#endif
+
+static const struct dev_pm_ops trf7970a_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(trf7970a_suspend, trf7970a_resume)
+ SET_RUNTIME_PM_OPS(trf7970a_pm_runtime_suspend,
+ trf7970a_pm_runtime_resume, NULL)
+};
+
+static const struct spi_device_id trf7970a_id_table[] = {
+ { "trf7970a", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, trf7970a_id_table);
+
+static struct spi_driver trf7970a_spi_driver = {
+ .probe = trf7970a_probe,
+ .remove = trf7970a_remove,
+ .id_table = trf7970a_id_table,
+ .driver = {
+ .name = "trf7970a",
+ .owner = THIS_MODULE,
+ .pm = &trf7970a_pm_ops,
+ },
+};
+
+module_spi_driver(trf7970a_spi_driver);
+
+MODULE_AUTHOR("Mark A. Greer <mgreer@animalcreek.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("TI trf7970a RFID/NFC Transceiver Driver");
Code Review / kvmfornfv.git / blobdiff