diff options
Diffstat (limited to 'drivers/nfc/trf7970a.c')
| -rw-r--r-- | drivers/nfc/trf7970a.c | 2270 |
1 files changed, 2270 insertions, 0 deletions
diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c new file mode 100644 index 000000000..c70f62fe3 --- /dev/null +++ b/drivers/nfc/trf7970a.c @@ -0,0 +1,2270 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * TI TRF7970a RFID/NFC Transceiver Driver + * + * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com + * + * Author: Erick Macias <emacias@ti.com> + * Author: Felipe Balbi <balbi@ti.com> + * Author: Mark A. Greer <mgreer@animalcreek.com> + */ + +#include <linux/module.h> +#include <linux/device.h> +#include <linux/netdevice.h> +#include <linux/interrupt.h> +#include <linux/pm_runtime.h> +#include <linux/nfc.h> +#include <linux/skbuff.h> +#include <linux/delay.h> +#include <linux/gpio/consumer.h> +#include <linux/of.h> +#include <linux/spi/spi.h> +#include <linux/regulator/consumer.h> + +#include <net/nfc/nfc.h> +#include <net/nfc/digital.h> + +/* There are 3 ways the host can communicate with the trf7970a: + * parallel mode, SPI with Slave Select (SS) mode, and SPI without + * SS mode. The driver only supports the two SPI modes. + * + * The trf7970a is very timing sensitive and the VIN, EN2, and EN + * pins must asserted in that order and with specific delays in between. + * The delays used in the driver were provided by TI and have been + * confirmed to work with this driver. There is a bug with the current + * version of the trf7970a that requires that EN2 remain low no matter + * what. If it goes high, it will generate an RF field even when in + * passive target mode. TI has indicated that the chip will work okay + * when EN2 is left low. The 'en2-rf-quirk' device tree property + * indicates that trf7970a currently being used has the erratum and + * that EN2 must be kept low. + * + * Timeouts are implemented using the delayed workqueue kernel facility. + * Timeouts are required so things don't hang when there is no response + * from the trf7970a (or tag). Using this mechanism creates a race with + * interrupts, however. That is, an interrupt and a timeout could occur + * closely enough together that one is blocked by the mutex while the other + * executes. When the timeout handler executes first and blocks the + * interrupt handler, it will eventually set the state to IDLE so the + * interrupt handler will check the state and exit with no harm done. + * When the interrupt handler executes first and blocks the timeout handler, + * the cancel_delayed_work() call will know that it didn't cancel the + * work item (i.e., timeout) and will return zero. That return code is + * used by the timer handler to indicate that it should ignore the timeout + * once its unblocked. + * + * Aborting an active command isn't as simple as it seems because the only + * way to abort a command that's already been sent to the tag is so turn + * off power to the tag. If we do that, though, we'd have to go through + * the entire anticollision procedure again but the digital layer doesn't + * support that. So, if an abort is received before trf7970a_send_cmd() + * has sent the command to the tag, it simply returns -ECANCELED. If the + * command has already been sent to the tag, then the driver continues + * normally and recieves the response data (or error) but just before + * sending the data upstream, it frees the rx_skb and sends -ECANCELED + * upstream instead. If the command failed, that error will be sent + * upstream. + * + * When recieving data from a tag and the interrupt status register has + * only the SRX bit set, it means that all of the data has been received + * (once what's in the fifo has been read). However, depending on timing + * an interrupt status with only the SRX bit set may not be recived. In + * those cases, the timeout mechanism is used to wait 20 ms in case more + * data arrives. After 20 ms, it is assumed that all of the data has been + * received and the accumulated rx data is sent upstream. The + * 'TRF7970A_ST_WAIT_FOR_RX_DATA_CONT' state is used for this purpose + * (i.e., it indicates that some data has been received but we're not sure + * if there is more coming so a timeout in this state means all data has + * been received and there isn't an error). The delay is 20 ms since delays + * of ~16 ms have been observed during testing. + * + * When transmitting a frame larger than the FIFO size (127 bytes), the + * driver will wait 20 ms for the FIFO to drain past the low-watermark + * and generate an interrupt. The low-watermark set to 32 bytes so the + * interrupt should fire after 127 - 32 = 95 bytes have been sent. At + * the lowest possible bit rate (6.62 kbps for 15693), it will take up + * to ~14.35 ms so 20 ms is used for the timeout. + * + * Type 2 write and sector select commands respond with a 4-bit ACK or NACK. + * Having only 4 bits in the FIFO won't normally generate an interrupt so + * driver enables the '4_bit_RX' bit of the Special Functions register 1 + * to cause an interrupt in that case. Leaving that bit for a read command + * messes up the data returned so it is only enabled when the framing is + * 'NFC_DIGITAL_FRAMING_NFCA_T2T' and the command is not a read command. + * Unfortunately, that means that the driver has to peek into tx frames + * when the framing is 'NFC_DIGITAL_FRAMING_NFCA_T2T'. This is done by + * the trf7970a_per_cmd_config() routine. + * + * ISO/IEC 15693 frames specify whether to use single or double sub-carrier + * frequencies and whether to use low or high data rates in the flags byte + * of the frame. This means that the driver has to peek at all 15693 frames + * to determine what speed to set the communication to. In addition, write + * and lock commands use the OPTION flag to indicate that an EOF must be + * sent to the tag before it will send its response. So the driver has to + * examine all frames for that reason too. + * + * It is unclear how long to wait before sending the EOF. According to the + * Note under Table 1-1 in section 1.6 of + * http://www.ti.com/lit/ug/scbu011/scbu011.pdf, that wait should be at least + * 10 ms for TI Tag-it HF-I tags; however testing has shown that is not long + * enough so 20 ms is used. So the timer is set to 40 ms - 20 ms to drain + * up to 127 bytes in the FIFO at the lowest bit rate plus another 20 ms to + * ensure the wait is long enough before sending the EOF. This seems to work + * reliably. + */ + +#define TRF7970A_SUPPORTED_PROTOCOLS \ + (NFC_PROTO_MIFARE_MASK | NFC_PROTO_ISO14443_MASK | \ + NFC_PROTO_ISO14443_B_MASK | NFC_PROTO_FELICA_MASK | \ + NFC_PROTO_ISO15693_MASK | NFC_PROTO_NFC_DEP_MASK) + +#define TRF7970A_AUTOSUSPEND_DELAY 30000 /* 30 seconds */ +#define TRF7970A_13MHZ_CLOCK_FREQUENCY 13560000 +#define TRF7970A_27MHZ_CLOCK_FREQUENCY 27120000 + +#define TRF7970A_RX_SKB_ALLOC_SIZE 256 + +#define TRF7970A_FIFO_SIZE 127 + +/* TX length is 3 nibbles long ==> 4KB - 1 bytes max */ +#define TRF7970A_TX_MAX (4096 - 1) + +#define TRF7970A_WAIT_FOR_TX_IRQ 20 +#define TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT 20 +#define TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT 20 +#define TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF 40 + +/* Guard times for various RF technologies (in us) */ +#define TRF7970A_GUARD_TIME_NFCA 5000 +#define TRF7970A_GUARD_TIME_NFCB 5000 +#define TRF7970A_GUARD_TIME_NFCF 20000 +#define TRF7970A_GUARD_TIME_15693 1000 + +/* Quirks */ +/* Erratum: When reading IRQ Status register on trf7970a, we must issue a + * read continuous command for IRQ Status and Collision Position registers. + */ +#define TRF7970A_QUIRK_IRQ_STATUS_READ BIT(0) +#define TRF7970A_QUIRK_EN2_MUST_STAY_LOW BIT(1) + +/* Direct commands */ +#define TRF7970A_CMD_IDLE 0x00 +#define TRF7970A_CMD_SOFT_INIT 0x03 +#define TRF7970A_CMD_RF_COLLISION 0x04 +#define TRF7970A_CMD_RF_COLLISION_RESPONSE_N 0x05 +#define TRF7970A_CMD_RF_COLLISION_RESPONSE_0 0x06 +#define TRF7970A_CMD_FIFO_RESET 0x0f +#define TRF7970A_CMD_TRANSMIT_NO_CRC 0x10 +#define TRF7970A_CMD_TRANSMIT 0x11 +#define TRF7970A_CMD_DELAY_TRANSMIT_NO_CRC 0x12 +#define TRF7970A_CMD_DELAY_TRANSMIT 0x13 +#define TRF7970A_CMD_EOF 0x14 +#define TRF7970A_CMD_CLOSE_SLOT 0x15 +#define TRF7970A_CMD_BLOCK_RX 0x16 +#define TRF7970A_CMD_ENABLE_RX 0x17 +#define TRF7970A_CMD_TEST_INT_RF 0x18 +#define TRF7970A_CMD_TEST_EXT_RF 0x19 +#define TRF7970A_CMD_RX_GAIN_ADJUST 0x1a + +/* Bits determining whether its a direct command or register R/W, + * whether to use a continuous SPI transaction or not, and the actual + * direct cmd opcode or 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(5) +#define TRF7970A_NFC_TARGET_LEVEL_LD_S_4BYTES (0x0 << 6) +#define TRF7970A_NFC_TARGET_LEVEL_LD_S_7BYTES (0x1 << 6) +#define TRF7970A_NFC_TARGET_LEVEL_LD_S_10BYTES (0x2 << 6) + +#define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106 BIT(0) +#define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212 BIT(1) +#define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424 (BIT(0) | BIT(1)) +#define TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B BIT(2) +#define TRF79070A_NFC_TARGET_PROTOCOL_PAS_106 BIT(3) +#define TRF79070A_NFC_TARGET_PROTOCOL_FELICA BIT(4) +#define TRF79070A_NFC_TARGET_PROTOCOL_RF_L BIT(6) +#define TRF79070A_NFC_TARGET_PROTOCOL_RF_H BIT(7) + +#define TRF79070A_NFC_TARGET_PROTOCOL_106A \ + (TRF79070A_NFC_TARGET_PROTOCOL_RF_H | \ + TRF79070A_NFC_TARGET_PROTOCOL_RF_L | \ + TRF79070A_NFC_TARGET_PROTOCOL_PAS_106 | \ + TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106) + +#define TRF79070A_NFC_TARGET_PROTOCOL_106B \ + (TRF79070A_NFC_TARGET_PROTOCOL_RF_H | \ + TRF79070A_NFC_TARGET_PROTOCOL_RF_L | \ + TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B | \ + TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106) + +#define TRF79070A_NFC_TARGET_PROTOCOL_212F \ + (TRF79070A_NFC_TARGET_PROTOCOL_RF_H | \ + TRF79070A_NFC_TARGET_PROTOCOL_RF_L | \ + TRF79070A_NFC_TARGET_PROTOCOL_FELICA | \ + TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212) + +#define TRF79070A_NFC_TARGET_PROTOCOL_424F \ + (TRF79070A_NFC_TARGET_PROTOCOL_RF_H | \ + TRF79070A_NFC_TARGET_PROTOCOL_RF_L | \ + TRF79070A_NFC_TARGET_PROTOCOL_FELICA | \ + TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424) + +#define TRF7970A_FIFO_STATUS_OVERFLOW BIT(7) + +/* NFC (ISO/IEC 14443A) Type 2 Tag commands */ +#define NFC_T2T_CMD_READ 0x30 + +/* ISO 15693 commands codes */ +#define ISO15693_CMD_INVENTORY 0x01 +#define ISO15693_CMD_READ_SINGLE_BLOCK 0x20 +#define ISO15693_CMD_WRITE_SINGLE_BLOCK 0x21 +#define ISO15693_CMD_LOCK_BLOCK 0x22 +#define ISO15693_CMD_READ_MULTIPLE_BLOCK 0x23 +#define ISO15693_CMD_WRITE_MULTIPLE_BLOCK 0x24 +#define ISO15693_CMD_SELECT 0x25 +#define ISO15693_CMD_RESET_TO_READY 0x26 +#define ISO15693_CMD_WRITE_AFI 0x27 +#define ISO15693_CMD_LOCK_AFI 0x28 +#define ISO15693_CMD_WRITE_DSFID 0x29 +#define ISO15693_CMD_LOCK_DSFID 0x2a +#define ISO15693_CMD_GET_SYSTEM_INFO 0x2b +#define ISO15693_CMD_GET_MULTIPLE_BLOCK_SECURITY_STATUS 0x2c + +/* ISO 15693 request and response flags */ +#define ISO15693_REQ_FLAG_SUB_CARRIER BIT(0) +#define ISO15693_REQ_FLAG_DATA_RATE BIT(1) +#define ISO15693_REQ_FLAG_INVENTORY BIT(2) +#define ISO15693_REQ_FLAG_PROTOCOL_EXT BIT(3) +#define ISO15693_REQ_FLAG_SELECT BIT(4) +#define ISO15693_REQ_FLAG_AFI BIT(4) +#define ISO15693_REQ_FLAG_ADDRESS BIT(5) +#define ISO15693_REQ_FLAG_NB_SLOTS BIT(5) +#define ISO15693_REQ_FLAG_OPTION BIT(6) + +#define ISO15693_REQ_FLAG_SPEED_MASK \ + (ISO15693_REQ_FLAG_SUB_CARRIER | ISO15693_REQ_FLAG_DATA_RATE) + +enum trf7970a_state { + TRF7970A_ST_PWR_OFF, + TRF7970A_ST_RF_OFF, + TRF7970A_ST_IDLE, + TRF7970A_ST_IDLE_RX_BLOCKED, + TRF7970A_ST_WAIT_FOR_TX_FIFO, + TRF7970A_ST_WAIT_FOR_RX_DATA, + TRF7970A_ST_WAIT_FOR_RX_DATA_CONT, + TRF7970A_ST_WAIT_TO_ISSUE_EOF, + TRF7970A_ST_LISTENING, + TRF7970A_ST_LISTENING_MD, + TRF7970A_ST_MAX +}; + +struct trf7970a { + enum trf7970a_state state; + struct device *dev; + struct spi_device *spi; + struct regulator *regulator; + struct nfc_digital_dev *ddev; + u32 quirks; + bool is_initiator; + bool aborting; + struct sk_buff *tx_skb; + struct sk_buff *rx_skb; + nfc_digital_cmd_complete_t cb; + void *cb_arg; + u8 chip_status_ctrl; + u8 iso_ctrl; + u8 iso_ctrl_tech; + u8 modulator_sys_clk_ctrl; + u8 special_fcn_reg1; + u8 io_ctrl; + unsigned int guard_time; + int technology; + int framing; + u8 md_rf_tech; + u8 tx_cmd; + bool issue_eof; + struct gpio_desc *en_gpiod; + struct gpio_desc *en2_gpiod; + struct mutex lock; + unsigned int timeout; + bool ignore_timeout; + struct delayed_work timeout_work; +}; + +static int trf7970a_cmd(struct trf7970a *trf, u8 opcode) +{ + u8 cmd = TRF7970A_CMD_BIT_CTRL | TRF7970A_CMD_BIT_OPCODE(opcode); + int ret; + + dev_dbg(trf->dev, "cmd: 0x%x\n", cmd); + + ret = spi_write(trf->spi, &cmd, 1); + if (ret) + dev_err(trf->dev, "%s - cmd: 0x%x, ret: %d\n", __func__, cmd, + ret); + return ret; +} + +static int trf7970a_read(struct trf7970a *trf, u8 reg, u8 *val) +{ + u8 addr = TRF7970A_CMD_BIT_RW | reg; + int ret; + + ret = spi_write_then_read(trf->spi, &addr, 1, val, 1); + if (ret) + dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr, + ret); + + dev_dbg(trf->dev, "read(0x%x): 0x%x\n", addr, *val); + + return ret; +} + +static int trf7970a_read_cont(struct trf7970a *trf, u8 reg, u8 *buf, + size_t len) +{ + u8 addr = reg | TRF7970A_CMD_BIT_RW | TRF7970A_CMD_BIT_CONTINUOUS; + struct spi_transfer t[2]; + struct spi_message m; + int ret; + + dev_dbg(trf->dev, "read_cont(0x%x, %zd)\n", addr, len); + + spi_message_init(&m); + + memset(&t, 0, sizeof(t)); + + t[0].tx_buf = &addr; + t[0].len = sizeof(addr); + spi_message_add_tail(&t[0], &m); + + t[1].rx_buf = buf; + t[1].len = len; + spi_message_add_tail(&t[1], &m); + + ret = spi_sync(trf->spi, &m); + if (ret) + dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr, + ret); + return ret; +} + +static int trf7970a_write(struct trf7970a *trf, u8 reg, u8 val) +{ + u8 buf[2] = { reg, val }; + int ret; + + dev_dbg(trf->dev, "write(0x%x): 0x%x\n", reg, val); + + ret = spi_write(trf->spi, buf, 2); + if (ret) + dev_err(trf->dev, "%s - write: 0x%x 0x%x, ret: %d\n", __func__, + buf[0], buf[1], ret); + + return ret; +} + +static int trf7970a_read_irqstatus(struct trf7970a *trf, u8 *status) +{ + int ret; + u8 buf[2]; + u8 addr; + + addr = TRF7970A_IRQ_STATUS | TRF7970A_CMD_BIT_RW; + + if (trf->quirks & TRF7970A_QUIRK_IRQ_STATUS_READ) { + addr |= TRF7970A_CMD_BIT_CONTINUOUS; + ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2); + } else { + ret = spi_write_then_read(trf->spi, &addr, 1, buf, 1); + } + + if (ret) + dev_err(trf->dev, "%s - irqstatus: Status read failed: %d\n", + __func__, ret); + else + *status = buf[0]; + + return ret; +} + +static int trf7970a_read_target_proto(struct trf7970a *trf, u8 *target_proto) +{ + int ret; + u8 buf[2]; + u8 addr; + + addr = TRF79070A_NFC_TARGET_PROTOCOL | TRF7970A_CMD_BIT_RW | + TRF7970A_CMD_BIT_CONTINUOUS; + + ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2); + if (ret) + dev_err(trf->dev, "%s - target_proto: Read failed: %d\n", + __func__, ret); + else + *target_proto = buf[0]; + + return ret; +} + +static int trf7970a_mode_detect(struct trf7970a *trf, u8 *rf_tech) +{ + int ret; + u8 target_proto, tech; + + ret = trf7970a_read_target_proto(trf, &target_proto); + if (ret) + return ret; + + switch (target_proto) { + case TRF79070A_NFC_TARGET_PROTOCOL_106A: + tech = NFC_DIGITAL_RF_TECH_106A; + break; + case TRF79070A_NFC_TARGET_PROTOCOL_106B: + tech = NFC_DIGITAL_RF_TECH_106B; + break; + case TRF79070A_NFC_TARGET_PROTOCOL_212F: + tech = NFC_DIGITAL_RF_TECH_212F; + break; + case TRF79070A_NFC_TARGET_PROTOCOL_424F: + tech = NFC_DIGITAL_RF_TECH_424F; + break; + default: + dev_dbg(trf->dev, "%s - mode_detect: target_proto: 0x%x\n", + __func__, target_proto); + return -EIO; + } + + *rf_tech = tech; + + return ret; +} + +static void trf7970a_send_upstream(struct trf7970a *trf) +{ + dev_kfree_skb_any(trf->tx_skb); + trf->tx_skb = NULL; + + if (trf->rx_skb && !IS_ERR(trf->rx_skb) && !trf->aborting) + print_hex_dump_debug("trf7970a rx data: ", DUMP_PREFIX_NONE, + 16, 1, trf->rx_skb->data, trf->rx_skb->len, + false); + + trf->state = TRF7970A_ST_IDLE; + + if (trf->aborting) { + dev_dbg(trf->dev, "Abort process complete\n"); + + if (!IS_ERR(trf->rx_skb)) { + kfree_skb(trf->rx_skb); + trf->rx_skb = ERR_PTR(-ECANCELED); + } + + trf->aborting = false; + } + + trf->cb(trf->ddev, trf->cb_arg, trf->rx_skb); + + trf->rx_skb = NULL; +} + +static void trf7970a_send_err_upstream(struct trf7970a *trf, int errno) +{ + dev_dbg(trf->dev, "Error - state: %d, errno: %d\n", trf->state, errno); + + cancel_delayed_work(&trf->timeout_work); + + kfree_skb(trf->rx_skb); + trf->rx_skb = ERR_PTR(errno); + + trf7970a_send_upstream(trf); +} + +static int trf7970a_transmit(struct trf7970a *trf, struct sk_buff *skb, + unsigned int len, u8 *prefix, + unsigned int prefix_len) +{ + struct spi_transfer t[2]; + struct spi_message m; + unsigned int timeout; + int ret; + + print_hex_dump_debug("trf7970a tx data: ", DUMP_PREFIX_NONE, + 16, 1, skb->data, len, false); + + spi_message_init(&m); + + memset(&t, 0, sizeof(t)); + + t[0].tx_buf = prefix; + t[0].len = prefix_len; + spi_message_add_tail(&t[0], &m); + + t[1].tx_buf = skb->data; + t[1].len = len; + spi_message_add_tail(&t[1], &m); + + ret = spi_sync(trf->spi, &m); + if (ret) { + dev_err(trf->dev, "%s - Can't send tx data: %d\n", __func__, + ret); + return ret; + } + + skb_pull(skb, len); + + if (skb->len > 0) { + trf->state = TRF7970A_ST_WAIT_FOR_TX_FIFO; + timeout = TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT; + } else { + if (trf->issue_eof) { + trf->state = TRF7970A_ST_WAIT_TO_ISSUE_EOF; + timeout = TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF; + } else { + trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA; + + if (!trf->timeout) + timeout = TRF7970A_WAIT_FOR_TX_IRQ; + else + timeout = trf->timeout; + } + } + + dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n", timeout, + trf->state); + + schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout)); + + return 0; +} + +static void trf7970a_fill_fifo(struct trf7970a *trf) +{ + struct sk_buff *skb = trf->tx_skb; + unsigned int len; + int ret; + u8 fifo_bytes; + u8 prefix; + + ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes); + if (ret) { + trf7970a_send_err_upstream(trf, ret); + return; + } + + dev_dbg(trf->dev, "Filling FIFO - fifo_bytes: 0x%x\n", fifo_bytes); + + fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW; + + /* Calculate how much more data can be written to the fifo */ + len = TRF7970A_FIFO_SIZE - fifo_bytes; + if (!len) { + schedule_delayed_work(&trf->timeout_work, + msecs_to_jiffies(TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT)); + return; + } + + len = min(skb->len, len); + + prefix = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_FIFO_IO_REGISTER; + + ret = trf7970a_transmit(trf, skb, len, &prefix, sizeof(prefix)); + if (ret) + trf7970a_send_err_upstream(trf, ret); +} + +static void trf7970a_drain_fifo(struct trf7970a *trf, u8 status) +{ + struct sk_buff *skb = trf->rx_skb; + int ret; + u8 fifo_bytes; + + if (status & TRF7970A_IRQ_STATUS_ERROR) { + trf7970a_send_err_upstream(trf, -EIO); + return; + } + + ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes); + if (ret) { + trf7970a_send_err_upstream(trf, ret); + return; + } + + dev_dbg(trf->dev, "Draining FIFO - fifo_bytes: 0x%x\n", fifo_bytes); + + fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW; + + if (!fifo_bytes) + goto no_rx_data; + + if (fifo_bytes > skb_tailroom(skb)) { + skb = skb_copy_expand(skb, skb_headroom(skb), + max_t(int, fifo_bytes, + TRF7970A_RX_SKB_ALLOC_SIZE), + GFP_KERNEL); + if (!skb) { + trf7970a_send_err_upstream(trf, -ENOMEM); + return; + } + + kfree_skb(trf->rx_skb); + trf->rx_skb = skb; + } + + ret = trf7970a_read_cont(trf, TRF7970A_FIFO_IO_REGISTER, + skb_put(skb, fifo_bytes), fifo_bytes); + if (ret) { + trf7970a_send_err_upstream(trf, ret); + return; + } + + /* If received Type 2 ACK/NACK, shift right 4 bits and pass up */ + if ((trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T) && (skb->len == 1) && + (trf->special_fcn_reg1 == TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX)) { + skb->data[0] >>= 4; + status = TRF7970A_IRQ_STATUS_SRX; + } else { + trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA_CONT; + + ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes); + if (ret) { + trf7970a_send_err_upstream(trf, ret); + return; + } + + fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW; + + /* If there are bytes in the FIFO, set status to '0' so + * the if stmt below doesn't fire and the driver will wait + * for the trf7970a to generate another RX interrupt. + */ + if (fifo_bytes) + status = 0; + } + +no_rx_data: + if (status == TRF7970A_IRQ_STATUS_SRX) { /* Receive complete */ + trf7970a_send_upstream(trf); + return; + } + + dev_dbg(trf->dev, "Setting timeout for %d ms\n", + TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT); + + schedule_delayed_work(&trf->timeout_work, + msecs_to_jiffies(TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT)); +} + +static irqreturn_t trf7970a_irq(int irq, void *dev_id) +{ + struct trf7970a *trf = dev_id; + int ret; + u8 status, fifo_bytes, iso_ctrl; + + mutex_lock(&trf->lock); + + if (trf->state == TRF7970A_ST_RF_OFF) { + mutex_unlock(&trf->lock); + return IRQ_NONE; + } + + ret = trf7970a_read_irqstatus(trf, &status); + if (ret) { + mutex_unlock(&trf->lock); + return IRQ_NONE; + } + + dev_dbg(trf->dev, "IRQ - state: %d, status: 0x%x\n", trf->state, + status); + + if (!status) { + mutex_unlock(&trf->lock); + return IRQ_NONE; + } + + switch (trf->state) { + case TRF7970A_ST_IDLE: + case TRF7970A_ST_IDLE_RX_BLOCKED: + /* If initiator and getting interrupts caused by RF noise, + * turn off the receiver to avoid unnecessary interrupts. + * It will be turned back on in trf7970a_send_cmd() when + * the next command is issued. + */ + if (trf->is_initiator && (status & TRF7970A_IRQ_STATUS_ERROR)) { + trf7970a_cmd(trf, TRF7970A_CMD_BLOCK_RX); + trf->state = TRF7970A_ST_IDLE_RX_BLOCKED; + } + + trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET); + break; + case TRF7970A_ST_WAIT_FOR_TX_FIFO: + if (status & TRF7970A_IRQ_STATUS_TX) { + trf->ignore_timeout = + !cancel_delayed_work(&trf->timeout_work); + trf7970a_fill_fifo(trf); + } else { + trf7970a_send_err_upstream(trf, -EIO); + } + break; + case TRF7970A_ST_WAIT_FOR_RX_DATA: + case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT: + if (status & TRF7970A_IRQ_STATUS_SRX) { + trf->ignore_timeout = + !cancel_delayed_work(&trf->timeout_work); + trf7970a_drain_fifo(trf, status); + } else if (status & TRF7970A_IRQ_STATUS_FIFO) { + ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, + &fifo_bytes); + + fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW; + + if (ret) + trf7970a_send_err_upstream(trf, ret); + else if (!fifo_bytes) + trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET); + } else if ((status == TRF7970A_IRQ_STATUS_TX) || + (!trf->is_initiator && + (status == (TRF7970A_IRQ_STATUS_TX | + TRF7970A_IRQ_STATUS_NFC_RF)))) { + trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET); + + if (!trf->timeout) { + trf->ignore_timeout = + !cancel_delayed_work(&trf->timeout_work); + trf->rx_skb = ERR_PTR(0); + trf7970a_send_upstream(trf); + break; + } + + if (trf->is_initiator) + break; + + iso_ctrl = trf->iso_ctrl; + + switch (trf->framing) { + case NFC_DIGITAL_FRAMING_NFCA_STANDARD: + trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC; + iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N; + trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */ + break; + case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A: + trf->tx_cmd = TRF7970A_CMD_TRANSMIT; + iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N; + trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */ + break; + case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE: + ret = trf7970a_write(trf, + TRF7970A_SPECIAL_FCN_REG1, + TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL); + if (ret) + goto err_unlock_exit; + + trf->special_fcn_reg1 = + TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL; + break; + default: + break; + } + + if (iso_ctrl != trf->iso_ctrl) { + ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, + iso_ctrl); + if (ret) + goto err_unlock_exit; + + trf->iso_ctrl = iso_ctrl; + } + } else { + trf7970a_send_err_upstream(trf, -EIO); + } + break; + case TRF7970A_ST_WAIT_TO_ISSUE_EOF: + if (status != TRF7970A_IRQ_STATUS_TX) + trf7970a_send_err_upstream(trf, -EIO); + break; + case TRF7970A_ST_LISTENING: + if (status & TRF7970A_IRQ_STATUS_SRX) { + trf->ignore_timeout = + !cancel_delayed_work(&trf->timeout_work); + trf7970a_drain_fifo(trf, status); + } else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) { + trf7970a_send_err_upstream(trf, -EIO); + } + break; + case TRF7970A_ST_LISTENING_MD: + if (status & TRF7970A_IRQ_STATUS_SRX) { + trf->ignore_timeout = + !cancel_delayed_work(&trf->timeout_work); + + ret = trf7970a_mode_detect(trf, &trf->md_rf_tech); + if (ret) { + trf7970a_send_err_upstream(trf, ret); + } else { + trf->state = TRF7970A_ST_LISTENING; + trf7970a_drain_fifo(trf, status); + } + } else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) { + trf7970a_send_err_upstream(trf, -EIO); + } + break; + default: + dev_err(trf->dev, "%s - Driver in invalid state: %d\n", + __func__, trf->state); + } + +err_unlock_exit: + mutex_unlock(&trf->lock); + return IRQ_HANDLED; +} + +static void trf7970a_issue_eof(struct trf7970a *trf) +{ + int ret; + + dev_dbg(trf->dev, "Issuing EOF\n"); + + ret = trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET); + if (ret) + trf7970a_send_err_upstream(trf, ret); + + ret = trf7970a_cmd(trf, TRF7970A_CMD_EOF); + if (ret) + trf7970a_send_err_upstream(trf, ret); + + trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA; + + dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n", + trf->timeout, trf->state); + + schedule_delayed_work(&trf->timeout_work, + msecs_to_jiffies(trf->timeout)); +} + +static void trf7970a_timeout_work_handler(struct work_struct *work) +{ + struct trf7970a *trf = container_of(work, struct trf7970a, + timeout_work.work); + + dev_dbg(trf->dev, "Timeout - state: %d, ignore_timeout: %d\n", + trf->state, trf->ignore_timeout); + + mutex_lock(&trf->lock); + + if (trf->ignore_timeout) + trf->ignore_timeout = false; + else if (trf->state == TRF7970A_ST_WAIT_FOR_RX_DATA_CONT) + trf7970a_drain_fifo(trf, TRF7970A_IRQ_STATUS_SRX); + else if (trf->state == TRF7970A_ST_WAIT_TO_ISSUE_EOF) + trf7970a_issue_eof(trf); + else + trf7970a_send_err_upstream(trf, -ETIMEDOUT); + + mutex_unlock(&trf->lock); +} + +static int trf7970a_init(struct trf7970a *trf) +{ + int ret; + + dev_dbg(trf->dev, "Initializing device - state: %d\n", trf->state); + + ret = trf7970a_cmd(trf, TRF7970A_CMD_SOFT_INIT); + if (ret) + goto err_out; + + ret = trf7970a_cmd(trf, TRF7970A_CMD_IDLE); + if (ret) + goto err_out; + + ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL, + trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1)); + if (ret) + goto err_out; + + ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0); + if (ret) + goto err_out; + + usleep_range(1000, 2000); + + trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON; + + ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL, + trf->modulator_sys_clk_ctrl); + if (ret) + goto err_out; + + ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS, + TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 | + TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32); + if (ret) + goto err_out; + + ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1, 0); + if (ret) + goto err_out; + + trf->special_fcn_reg1 = 0; + + trf->iso_ctrl = 0xff; + return 0; + +err_out: + dev_dbg(trf->dev, "Couldn't init device: %d\n", ret); + return ret; +} + +static void trf7970a_switch_rf_off(struct trf7970a *trf) +{ + if ((trf->state == TRF7970A_ST_PWR_OFF) || + (trf->state == TRF7970A_ST_RF_OFF)) + return; + + dev_dbg(trf->dev, "Switching rf off\n"); + + trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON; + + trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, trf->chip_status_ctrl); + + trf->aborting = false; + trf->state = TRF7970A_ST_RF_OFF; + + pm_runtime_mark_last_busy(trf->dev); + pm_runtime_put_autosuspend(trf->dev); +} + +static int trf7970a_switch_rf_on(struct trf7970a *trf) +{ + int ret; + + dev_dbg(trf->dev, "Switching rf on\n"); + + pm_runtime_get_sync(trf->dev); + + if (trf->state != TRF7970A_ST_RF_OFF) { /* Power on, RF off */ + dev_err(trf->dev, "%s - Incorrect state: %d\n", __func__, + trf->state); + return -EINVAL; + } + + ret = trf7970a_init(trf); + if (ret) { + dev_err(trf->dev, "%s - Can't initialize: %d\n", __func__, ret); + return ret; + } + + trf->state = TRF7970A_ST_IDLE; + + return 0; +} + +static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on) +{ + struct trf7970a *trf = nfc_digital_get_drvdata(ddev); + int ret = 0; + + dev_dbg(trf->dev, "Switching RF - state: %d, on: %d\n", trf->state, on); + + mutex_lock(&trf->lock); + + if (on) { + switch (trf->state) { + case TRF7970A_ST_PWR_OFF: + case TRF7970A_ST_RF_OFF: + ret = trf7970a_switch_rf_on(trf); + break; + case TRF7970A_ST_IDLE: + case TRF7970A_ST_IDLE_RX_BLOCKED: + break; + default: + dev_err(trf->dev, "%s - Invalid request: %d %d\n", + __func__, trf->state, on); + trf7970a_switch_rf_off(trf); + ret = -EINVAL; + } + } else { + switch (trf->state) { + case TRF7970A_ST_PWR_OFF: + case TRF7970A_ST_RF_OFF: + break; + default: + dev_err(trf->dev, "%s - Invalid request: %d %d\n", + __func__, trf->state, on); + ret = -EINVAL; + fallthrough; + case TRF7970A_ST_IDLE: + case TRF7970A_ST_IDLE_RX_BLOCKED: + case TRF7970A_ST_WAIT_FOR_RX_DATA: + case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT: + trf7970a_switch_rf_off(trf); + } + } + + mutex_unlock(&trf->lock); + return ret; +} + +static int trf7970a_in_config_rf_tech(struct trf7970a *trf, int tech) +{ + int ret = 0; + + dev_dbg(trf->dev, "rf technology: %d\n", tech); + + switch (tech) { + case NFC_DIGITAL_RF_TECH_106A: + trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443A_106; + trf->modulator_sys_clk_ctrl = + (trf->modulator_sys_clk_ctrl & 0xf8) | + TRF7970A_MODULATOR_DEPTH_OOK; + trf->guard_time = TRF7970A_GUARD_TIME_NFCA; + break; + case NFC_DIGITAL_RF_TECH_106B: + trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443B_106; + trf->modulator_sys_clk_ctrl = + (trf->modulator_sys_clk_ctrl & 0xf8) | + TRF7970A_MODULATOR_DEPTH_ASK10; + trf->guard_time = TRF7970A_GUARD_TIME_NFCB; + break; + case NFC_DIGITAL_RF_TECH_212F: + trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_212; + trf->modulator_sys_clk_ctrl = + (trf->modulator_sys_clk_ctrl & 0xf8) | + TRF7970A_MODULATOR_DEPTH_ASK10; + trf->guard_time = TRF7970A_GUARD_TIME_NFCF; + break; + case NFC_DIGITAL_RF_TECH_424F: + trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_424; + trf->modulator_sys_clk_ctrl = + (trf->modulator_sys_clk_ctrl & 0xf8) | + TRF7970A_MODULATOR_DEPTH_ASK10; + trf->guard_time = TRF7970A_GUARD_TIME_NFCF; + break; + case NFC_DIGITAL_RF_TECH_ISO15693: + trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648; + trf->modulator_sys_clk_ctrl = + (trf->modulator_sys_clk_ctrl & 0xf8) | + TRF7970A_MODULATOR_DEPTH_OOK; + trf->guard_time = TRF7970A_GUARD_TIME_15693; + break; + default: + dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech); + return -EINVAL; + } + + trf->technology = tech; + + /* If in initiator mode and not changing the RF tech due to a + * PSL sequence (indicated by 'trf->iso_ctrl == 0xff' from + * trf7970a_init()), clear the NFC Target Detection Level register + * due to erratum. + */ + if (trf->iso_ctrl == 0xff) + ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0); + + return ret; +} + +static int trf7970a_is_rf_field(struct trf7970a *trf, bool *is_rf_field) +{ + int ret; + u8 rssi; + + ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, + trf->chip_status_ctrl | + TRF7970A_CHIP_STATUS_REC_ON); + if (ret) + return ret; + + ret = trf7970a_cmd(trf, TRF7970A_CMD_TEST_EXT_RF); + if (ret) + return ret; + + usleep_range(50, 60); + + ret = trf7970a_read(trf, TRF7970A_RSSI_OSC_STATUS, &rssi); + if (ret) + return ret; + + ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, + trf->chip_status_ctrl); + if (ret) + return ret; + + if (rssi & TRF7970A_RSSI_OSC_STATUS_RSSI_MASK) + *is_rf_field = true; + else + *is_rf_field = false; + + return 0; +} + +static int trf7970a_in_config_framing(struct trf7970a *trf, int framing) +{ + u8 iso_ctrl = trf->iso_ctrl_tech; + bool is_rf_field = false; + int ret; + + dev_dbg(trf->dev, "framing: %d\n", framing); + + switch (framing) { + case NFC_DIGITAL_FRAMING_NFCA_SHORT: + case NFC_DIGITAL_FRAMING_NFCA_STANDARD: + trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC; + iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N; + break; + case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A: + case NFC_DIGITAL_FRAMING_NFCA_T4T: + case NFC_DIGITAL_FRAMING_NFCB: + case NFC_DIGITAL_FRAMING_NFCB_T4T: + case NFC_DIGITAL_FRAMING_NFCF: + case NFC_DIGITAL_FRAMING_NFCF_T3T: + case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY: + case NFC_DIGITAL_FRAMING_ISO15693_T5T: + case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP: + case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP: + trf->tx_cmd = TRF7970A_CMD_TRANSMIT; + iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N; + break; + case NFC_DIGITAL_FRAMING_NFCA_T2T: + trf->tx_cmd = TRF7970A_CMD_TRANSMIT; + iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N; + break; + default: + dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing); + return -EINVAL; + } + + trf->framing = framing; + + if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) { + ret = trf7970a_is_rf_field(trf, &is_rf_field); + if (ret) + return ret; + + if (is_rf_field) + return -EBUSY; + } + + if (iso_ctrl != trf->iso_ctrl) { + ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl); + if (ret) + return ret; + + trf->iso_ctrl = iso_ctrl; + + ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL, + trf->modulator_sys_clk_ctrl); + if (ret) + return ret; + } + + if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) { + ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, + trf->chip_status_ctrl | + TRF7970A_CHIP_STATUS_RF_ON); + if (ret) + return ret; + + trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON; + + usleep_range(trf->guard_time, trf->guard_time + 1000); + } + + return 0; +} + +static int trf7970a_in_configure_hw(struct nfc_digital_dev *ddev, int type, + int param) +{ + struct trf7970a *trf = nfc_digital_get_drvdata(ddev); + int ret; + + dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param); + + mutex_lock(&trf->lock); + + trf->is_initiator = true; + + if ((trf->state == TRF7970A_ST_PWR_OFF) || + (trf->state == TRF7970A_ST_RF_OFF)) { + ret = trf7970a_switch_rf_on(trf); + if (ret) + goto err_unlock; + } + + switch (type) { + case NFC_DIGITAL_CONFIG_RF_TECH: + ret = trf7970a_in_config_rf_tech(trf, param); + break; + case NFC_DIGITAL_CONFIG_FRAMING: + ret = trf7970a_in_config_framing(trf, param); + break; + default: + dev_dbg(trf->dev, "Unknown type: %d\n", type); + ret = -EINVAL; + } + +err_unlock: + mutex_unlock(&trf->lock); + return ret; +} + +static int trf7970a_is_iso15693_write_or_lock(u8 cmd) +{ + switch (cmd) { + case ISO15693_CMD_WRITE_SINGLE_BLOCK: + case ISO15693_CMD_LOCK_BLOCK: + case ISO15693_CMD_WRITE_MULTIPLE_BLOCK: + case ISO15693_CMD_WRITE_AFI: + case ISO15693_CMD_LOCK_AFI: + case ISO15693_CMD_WRITE_DSFID: + case ISO15693_CMD_LOCK_DSFID: + return 1; + default: + return 0; + } +} + +static int trf7970a_per_cmd_config(struct trf7970a *trf, 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 = + (trf->modulator_sys_clk_ctrl & 0xf8) | + TRF7970A_MODULATOR_DEPTH_OOK; + break; + case NFC_DIGITAL_RF_TECH_212F: + trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE | + TRF7970A_ISO_CTRL_NFC_NFCF_212; + trf->modulator_sys_clk_ctrl = + (trf->modulator_sys_clk_ctrl & 0xf8) | + TRF7970A_MODULATOR_DEPTH_ASK10; + break; + case NFC_DIGITAL_RF_TECH_424F: + trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE | + TRF7970A_ISO_CTRL_NFC_NFCF_424; + trf->modulator_sys_clk_ctrl = + (trf->modulator_sys_clk_ctrl & 0xf8) | + TRF7970A_MODULATOR_DEPTH_ASK10; + break; + default: + dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech); + return -EINVAL; + } + + trf->technology = tech; + + /* Normally we write the ISO_CTRL register in + * trf7970a_tg_config_framing() because the framing can change + * the value written. However, when sending a PSL RES, + * digital_tg_send_psl_res_complete() doesn't call + * trf7970a_tg_config_framing() so we must write the register + * here. + */ + if ((trf->framing == NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED) && + (trf->iso_ctrl_tech != trf->iso_ctrl)) { + ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, + trf->iso_ctrl_tech); + + trf->iso_ctrl = trf->iso_ctrl_tech; + } + + return ret; +} + +/* Since this is a target routine, several of the framing calls are + * made between receiving the request and sending the response so they + * should take effect until after the response is sent. This is accomplished + * by skipping the ISO_CTRL register write here and doing it in the interrupt + * handler. + */ +static int trf7970a_tg_config_framing(struct trf7970a *trf, int framing) +{ + u8 iso_ctrl = trf->iso_ctrl_tech; + int ret; + + dev_dbg(trf->dev, "framing: %d\n", framing); + + switch (framing) { + case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP: + trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC; + iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N; + break; + case NFC_DIGITAL_FRAMING_NFCA_STANDARD: + case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A: + case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE: + /* These ones are applied in the interrupt handler */ + iso_ctrl = trf->iso_ctrl; /* Don't write to ISO_CTRL yet */ + break; + case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP: + trf->tx_cmd = TRF7970A_CMD_TRANSMIT; + iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N; + break; + case NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED: + trf->tx_cmd = TRF7970A_CMD_TRANSMIT; + iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N; + break; + default: + dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing); + return -EINVAL; + } + + trf->framing = framing; + + if (iso_ctrl != trf->iso_ctrl) { + ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl); + if (ret) + return ret; + + trf->iso_ctrl = iso_ctrl; + + ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL, + trf->modulator_sys_clk_ctrl); + if (ret) + return ret; + } + + if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) { + ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, + trf->chip_status_ctrl | + TRF7970A_CHIP_STATUS_RF_ON); + if (ret) + return ret; + + trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON; + } + + return 0; +} + +static int trf7970a_tg_configure_hw(struct nfc_digital_dev *ddev, int type, + int param) +{ + struct trf7970a *trf = nfc_digital_get_drvdata(ddev); + int ret; + + dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param); + + mutex_lock(&trf->lock); + + trf->is_initiator = false; + + if ((trf->state == TRF7970A_ST_PWR_OFF) || + (trf->state == TRF7970A_ST_RF_OFF)) { + ret = trf7970a_switch_rf_on(trf); + if (ret) + goto err_unlock; + } + + switch (type) { + case NFC_DIGITAL_CONFIG_RF_TECH: + ret = trf7970a_tg_config_rf_tech(trf, param); + break; + case NFC_DIGITAL_CONFIG_FRAMING: + ret = trf7970a_tg_config_framing(trf, param); + break; + default: + dev_dbg(trf->dev, "Unknown type: %d\n", type); + ret = -EINVAL; + } + +err_unlock: + mutex_unlock(&trf->lock); + return ret; +} + +static int _trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout, + nfc_digital_cmd_complete_t cb, void *arg, + bool mode_detect) +{ + struct trf7970a *trf = nfc_digital_get_drvdata(ddev); + int ret; + + mutex_lock(&trf->lock); + + if ((trf->state != TRF7970A_ST_IDLE) && + (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) { + dev_err(trf->dev, "%s - Bogus state: %d\n", __func__, + trf->state); + ret = -EIO; + goto out_err; + } + + if (trf->aborting) { + dev_dbg(trf->dev, "Abort process complete\n"); + trf->aborting = false; + ret = -ECANCELED; + goto out_err; + } + + trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE, + GFP_KERNEL); + if (!trf->rx_skb) { + dev_dbg(trf->dev, "Can't alloc rx_skb\n"); + ret = -ENOMEM; + goto out_err; + } + + ret = trf7970a_write(trf, TRF7970A_RX_SPECIAL_SETTINGS, + TRF7970A_RX_SPECIAL_SETTINGS_HBT | + TRF7970A_RX_SPECIAL_SETTINGS_M848 | + TRF7970A_RX_SPECIAL_SETTINGS_C424 | + TRF7970A_RX_SPECIAL_SETTINGS_C212); + if (ret) + goto out_err; + + ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL, + trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1)); + if (ret) + goto out_err; + + ret = trf7970a_write(trf, TRF7970A_NFC_LOW_FIELD_LEVEL, + TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(0x3)); + if (ret) + goto out_err; + + ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, + TRF7970A_NFC_TARGET_LEVEL_RFDET(0x7)); + if (ret) + goto out_err; + + trf->ddev = ddev; + trf->cb = cb; + trf->cb_arg = arg; + trf->timeout = timeout; + trf->ignore_timeout = false; + + ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX); + if (ret) + goto out_err; + + trf->state = mode_detect ? TRF7970A_ST_LISTENING_MD : + TRF7970A_ST_LISTENING; + + schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout)); + +out_err: + mutex_unlock(&trf->lock); + return ret; +} + +static int trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout, + nfc_digital_cmd_complete_t cb, void *arg) +{ + 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->en2_gpiod && + !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW)) { + gpiod_set_value_cansleep(trf->en2_gpiod, 1); + usleep_range(1000, 2000); + } + + gpiod_set_value_cansleep(trf->en_gpiod, 1); + + usleep_range(20000, 21000); + + trf->state = TRF7970A_ST_RF_OFF; + + return 0; +} + +static int trf7970a_power_down(struct trf7970a *trf) +{ + int ret; + + dev_dbg(trf->dev, "Powering down - state: %d\n", trf->state); + + if (trf->state == TRF7970A_ST_PWR_OFF) + return 0; + + if (trf->state != TRF7970A_ST_RF_OFF) { + dev_dbg(trf->dev, "Can't power down - not RF_OFF state (%d)\n", + trf->state); + return -EBUSY; + } + + gpiod_set_value_cansleep(trf->en_gpiod, 0); + + if (trf->en2_gpiod && !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW)) + gpiod_set_value_cansleep(trf->en2_gpiod, 0); + + ret = regulator_disable(trf->regulator); + if (ret) + dev_err(trf->dev, "%s - Can't disable VIN: %d\n", __func__, + ret); + + trf->state = TRF7970A_ST_PWR_OFF; + + return ret; +} + +static int trf7970a_startup(struct trf7970a *trf) +{ + int ret; + + ret = trf7970a_power_up(trf); + if (ret) + return ret; + + pm_runtime_set_active(trf->dev); + pm_runtime_enable(trf->dev); + pm_runtime_mark_last_busy(trf->dev); + + return 0; +} + +static void trf7970a_shutdown(struct trf7970a *trf) +{ + switch (trf->state) { + case TRF7970A_ST_WAIT_FOR_TX_FIFO: + case TRF7970A_ST_WAIT_FOR_RX_DATA: + case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT: + case TRF7970A_ST_WAIT_TO_ISSUE_EOF: + case TRF7970A_ST_LISTENING: + trf7970a_send_err_upstream(trf, -ECANCELED); + fallthrough; + case TRF7970A_ST_IDLE: + case TRF7970A_ST_IDLE_RX_BLOCKED: + trf7970a_switch_rf_off(trf); + break; + default: + break; + } + + pm_runtime_disable(trf->dev); + pm_runtime_set_suspended(trf->dev); + + trf7970a_power_down(trf); +} + +static int trf7970a_get_autosuspend_delay(struct device_node *np) +{ + int autosuspend_delay, ret; + + ret = of_property_read_u32(np, "autosuspend-delay", &autosuspend_delay); + if (ret) + autosuspend_delay = TRF7970A_AUTOSUSPEND_DELAY; + + return autosuspend_delay; +} + +static int trf7970a_probe(struct spi_device *spi) +{ + struct device_node *np = spi->dev.of_node; + struct trf7970a *trf; + int uvolts, autosuspend_delay, ret; + u32 clk_freq = TRF7970A_13MHZ_CLOCK_FREQUENCY; + + if (!np) { + dev_err(&spi->dev, "No Device Tree entry\n"); + return -EINVAL; + } + + trf = devm_kzalloc(&spi->dev, sizeof(*trf), GFP_KERNEL); + if (!trf) + return -ENOMEM; + + trf->state = TRF7970A_ST_PWR_OFF; + trf->dev = &spi->dev; + trf->spi = spi; + + spi->mode = SPI_MODE_1; + spi->bits_per_word = 8; + + ret = spi_setup(spi); + if (ret < 0) { + dev_err(trf->dev, "Can't set up SPI Communication\n"); + return ret; + } + + if (of_property_read_bool(np, "irq-status-read-quirk")) + trf->quirks |= TRF7970A_QUIRK_IRQ_STATUS_READ; + + /* There are two enable pins - only EN must be present in the DT */ + trf->en_gpiod = devm_gpiod_get_index(trf->dev, "ti,enable", 0, + GPIOD_OUT_LOW); + if (IS_ERR(trf->en_gpiod)) { + dev_err(trf->dev, "No EN GPIO property\n"); + return PTR_ERR(trf->en_gpiod); + } + + trf->en2_gpiod = devm_gpiod_get_index_optional(trf->dev, "ti,enable", 1, + GPIOD_OUT_LOW); + if (!trf->en2_gpiod) { + dev_info(trf->dev, "No EN2 GPIO property\n"); + } else if (IS_ERR(trf->en2_gpiod)) { + dev_err(trf->dev, "Error getting EN2 GPIO property: %ld\n", + PTR_ERR(trf->en2_gpiod)); + return PTR_ERR(trf->en2_gpiod); + } else if (of_property_read_bool(np, "en2-rf-quirk")) { + trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW; + } + + of_property_read_u32(np, "clock-frequency", &clk_freq); + if ((clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY) && + (clk_freq != TRF7970A_13MHZ_CLOCK_FREQUENCY)) { + dev_err(trf->dev, + "clock-frequency (%u Hz) unsupported\n", clk_freq); + return -EINVAL; + } + + if (clk_freq == TRF7970A_27MHZ_CLOCK_FREQUENCY) { + trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_27MHZ; + dev_dbg(trf->dev, "trf7970a configured for 27MHz crystal\n"); + } else { + trf->modulator_sys_clk_ctrl = 0; + } + + ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL, + trf7970a_irq, + IRQF_TRIGGER_RISING | IRQF_ONESHOT, + "trf7970a", trf); + if (ret) { + dev_err(trf->dev, "Can't request IRQ#%d: %d\n", spi->irq, ret); + return ret; + } + + mutex_init(&trf->lock); + INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler); + + trf->regulator = devm_regulator_get(&spi->dev, "vin"); + if (IS_ERR(trf->regulator)) { + ret = PTR_ERR(trf->regulator); + dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret); + goto err_destroy_lock; + } + + ret = regulator_enable(trf->regulator); + if (ret) { + dev_err(trf->dev, "Can't enable VIN: %d\n", ret); + goto err_destroy_lock; + } + + uvolts = regulator_get_voltage(trf->regulator); + if (uvolts > 4000000) + trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3; + + trf->regulator = devm_regulator_get(&spi->dev, "vdd-io"); + if (IS_ERR(trf->regulator)) { + ret = PTR_ERR(trf->regulator); + dev_err(trf->dev, "Can't get VDD_IO regulator: %d\n", ret); + goto err_destroy_lock; + } + + ret = regulator_enable(trf->regulator); + if (ret) { + dev_err(trf->dev, "Can't enable VDD_IO: %d\n", ret); + goto err_destroy_lock; + } + + if (regulator_get_voltage(trf->regulator) == 1800000) { + trf->io_ctrl = TRF7970A_REG_IO_CTRL_IO_LOW; + dev_dbg(trf->dev, "trf7970a config vdd_io to 1.8V\n"); + } + + trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops, + TRF7970A_SUPPORTED_PROTOCOLS, + NFC_DIGITAL_DRV_CAPS_IN_CRC | + NFC_DIGITAL_DRV_CAPS_TG_CRC, 0, + 0); + if (!trf->ddev) { + dev_err(trf->dev, "Can't allocate NFC digital device\n"); + ret = -ENOMEM; + goto err_disable_regulator; + } + + nfc_digital_set_parent_dev(trf->ddev, trf->dev); + nfc_digital_set_drvdata(trf->ddev, trf); + spi_set_drvdata(spi, trf); + + autosuspend_delay = trf7970a_get_autosuspend_delay(np); + + pm_runtime_set_autosuspend_delay(trf->dev, autosuspend_delay); + pm_runtime_use_autosuspend(trf->dev); + + ret = trf7970a_startup(trf); + if (ret) + goto err_free_ddev; + + ret = nfc_digital_register_device(trf->ddev); + if (ret) { + dev_err(trf->dev, "Can't register NFC digital device: %d\n", + ret); + goto err_shutdown; + } + + return 0; + +err_shutdown: + trf7970a_shutdown(trf); +err_free_ddev: + nfc_digital_free_device(trf->ddev); +err_disable_regulator: + regulator_disable(trf->regulator); +err_destroy_lock: + mutex_destroy(&trf->lock); + return ret; +} + +static 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 = to_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 = to_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 = to_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 = to_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 of_device_id trf7970a_of_match[] = { + {.compatible = "ti,trf7970a",}, + {}, +}; + +MODULE_DEVICE_TABLE(of, trf7970a_of_match); + +static const struct spi_device_id trf7970a_id_table[] = { + {"trf7970a", 0}, + {} +}; + +MODULE_DEVICE_TABLE(spi, trf7970a_id_table); + +static struct spi_driver trf7970a_spi_driver = { + .probe = trf7970a_probe, + .remove = trf7970a_remove, + .id_table = trf7970a_id_table, + .driver = { + .name = "trf7970a", + .of_match_table = of_match_ptr(trf7970a_of_match), + .pm = &trf7970a_pm_ops, + }, +}; + +module_spi_driver(trf7970a_spi_driver); + +MODULE_AUTHOR("Mark A. Greer <mgreer@animalcreek.com>"); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("TI trf7970a RFID/NFC Transceiver Driver"); |