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linux/drivers/nfc/trf7970a.c
Uwe Kleine-König a0386bba70
spi: make remove callback a void function 
The value returned by an spi driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Claudius Heine <ch@denx.de>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC
Acked-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Acked-by: Łukasz Stelmach <l.stelmach@samsung.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220123175201.34839-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>
2022-02-09 13:00:45 +00:00

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// 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 register 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, const 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,
const struct sk_buff *skb)
{
const 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)
{
const 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)
{
const 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)
{
const 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 const 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(const 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)
{
const 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 void 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);
}
#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);
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;
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;
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;
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");
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