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linux/drivers/nfc/trf7970a.c
Mark A. Greer 5fa3af352b NFC: trf7970a: Increase TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT to 20 ms 
After further testing periods of ~16 ms have been observed
between interrupts indicating that there is receive data in
the FIFO.  To accomodate that, increase the time the driver
waits before deciding there is no more data to receive to
20 ms.  The macro that represents that delay is
'TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT'.

Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2014-04-22 00:37:26 +02:00

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38 KiB
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/*
* TI TRF7970a RFID/NFC Transceiver Driver
*
* Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
*
* Author: Erick Macias <emacias@ti.com>
* Author: Felipe Balbi <balbi@ti.com>
* Author: Mark A. Greer <mgreer@animalcreek.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 of
* the License as published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/device.h>
#include <linux/netdevice.h>
#include <linux/interrupt.h>
#include <linux/nfc.h>
#include <linux/skbuff.h>
#include <linux/delay.h>
#include <linux/gpio.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/spi/spi.h>
#include <linux/regulator/consumer.h>
#include <net/nfc/nfc.h>
#include <net/nfc/digital.h>
/* There are 3 ways the host can communicate with the trf7970a:
* parallel mode, SPI with Slave Select (SS) mode, and SPI without
* SS mode. The driver only supports the two SPI modes.
*
* The trf7970a is very timing sensitive and the VIN, EN2, and EN
* pins must asserted in that order and with specific delays in between.
* The delays used in the driver were provided by TI and have been
* confirmed to work with this driver.
*
* 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_in_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.
*
* 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. For this reason, the driver waits 20 ms which seems to work
* reliably.
*/
#define TRF7970A_SUPPORTED_PROTOCOLS \
(NFC_PROTO_MIFARE_MASK | NFC_PROTO_ISO14443_MASK | \
NFC_PROTO_ISO15693_MASK)
/* 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.
*/
#define TRF7970A_TX_SKB_HEADROOM 5
#define TRF7970A_RX_SKB_ALLOC_SIZE 256
#define TRF7970A_FIFO_SIZE 128
/* TX length is 3 nibbles long ==> 4KB - 1 bytes max */
#define TRF7970A_TX_MAX (4096 - 1)
#define TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT 20
#define TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT 3
#define TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF 20
/* 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_ERRATA BIT(0)
/* 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_EXT_RF 0x18
#define TRF7970A_CMD_TEST_INT_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_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)
/* IRQ Status Register Bits */
#define TRF7970A_IRQ_STATUS_NORESP BIT(0) /* ISO15693 only */
#define TRF7970A_IRQ_STATUS_COL BIT(1)
#define TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR BIT(2)
#define TRF7970A_IRQ_STATUS_PARITY_ERROR BIT(3)
#define TRF7970A_IRQ_STATUS_CRC_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_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_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_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_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 powering_up;
bool aborting;
struct sk_buff *tx_skb;
struct sk_buff *rx_skb;
nfc_digital_cmd_complete_t cb;
void *cb_arg;
u8 iso_ctrl;
u8 special_fcn_reg1;
int technology;
int framing;
u8 tx_cmd;
bool issue_eof;
int en2_gpio;
int en_gpio;
struct mutex lock;
unsigned int timeout;
bool ignore_timeout;
struct delayed_work timeout_work;
};
static int trf7970a_cmd(struct trf7970a *trf, u8 opcode)
{
u8 cmd = TRF7970A_CMD_BIT_CTRL | TRF7970A_CMD_BIT_OPCODE(opcode);
int ret;
dev_dbg(trf->dev, "cmd: 0x%x\n", cmd);
ret = spi_write(trf->spi, &cmd, 1);
if (ret)
dev_err(trf->dev, "%s - cmd: 0x%x, ret: %d\n", __func__, cmd,
ret);
return ret;
}
static int trf7970a_read(struct trf7970a *trf, u8 reg, u8 *val)
{
u8 addr = TRF7970A_CMD_BIT_RW | reg;
int ret;
ret = spi_write_then_read(trf->spi, &addr, 1, val, 1);
if (ret)
dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
ret);
dev_dbg(trf->dev, "read(0x%x): 0x%x\n", addr, *val);
return ret;
}
static int trf7970a_read_cont(struct trf7970a *trf, u8 reg,
u8 *buf, size_t len)
{
u8 addr = reg | TRF7970A_CMD_BIT_RW | TRF7970A_CMD_BIT_CONTINUOUS;
int ret;
dev_dbg(trf->dev, "read_cont(0x%x, %zd)\n", addr, len);
ret = spi_write_then_read(trf->spi, &addr, 1, buf, len);
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_ERRATA) {
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 void trf7970a_send_upstream(struct trf7970a *trf)
{
u8 rssi;
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);
/* According to the manual it is "good form" to reset the fifo and
* read the RSSI levels & oscillator status register here. It doesn't
* explain why.
*/
trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
trf7970a_read(trf, TRF7970A_RSSI_OSC_STATUS, &rssi);
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);
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)
{
unsigned int timeout;
int ret;
print_hex_dump_debug("trf7970a tx data: ", DUMP_PREFIX_NONE,
16, 1, skb->data, len, false);
ret = spi_write(trf->spi, skb->data, len);
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;
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;
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);
if (fifo_bytes & TRF7970A_FIFO_STATUS_OVERFLOW) {
dev_err(trf->dev, "%s - fifo overflow: 0x%x\n", __func__,
fifo_bytes);
trf7970a_send_err_upstream(trf, -EIO);
return;
}
/* Calculate how much more data can be written to the fifo */
len = TRF7970A_FIFO_SIZE - fifo_bytes;
len = min(skb->len, len);
ret = trf7970a_transmit(trf, skb, len);
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);
if (!fifo_bytes)
goto no_rx_data;
if (fifo_bytes & TRF7970A_FIFO_STATUS_OVERFLOW) {
dev_err(trf->dev, "%s - fifo overflow: 0x%x\n", __func__,
fifo_bytes);
trf7970a_send_err_upstream(trf, -EIO);
return;
}
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;
}
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;
mutex_lock(&trf->lock);
if (trf->state == TRF7970A_ST_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 getting interrupts caused by RF noise, turn off the
* receiver to avoid unnecessary interrupts. It will be
* turned back on in trf7970a_in_send_cmd() when the next
* command is issued.
*/
if (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_TX)) {
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;
default:
dev_err(trf->dev, "%s - Driver in invalid state: %d\n",
__func__, trf->state);
}
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_send_upstream(trf); /* No more rx data so send up */
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_MODULATOR_SYS_CLK_CTRL,
TRF7970A_MODULATOR_DEPTH_OOK);
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;
ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
TRF7970A_CHIP_STATUS_RF_ON |
TRF7970A_CHIP_STATUS_VRS5_3);
if (ret)
goto err_out;
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)
{
dev_dbg(trf->dev, "Switching rf off\n");
gpio_set_value(trf->en_gpio, 0);
gpio_set_value(trf->en2_gpio, 0);
trf->aborting = false;
trf->state = TRF7970A_ST_OFF;
}
static int trf7970a_switch_rf_on(struct trf7970a *trf)
{
unsigned long delay;
int ret;
dev_dbg(trf->dev, "Switching rf on\n");
if (trf->powering_up)
usleep_range(5000, 6000);
gpio_set_value(trf->en2_gpio, 1);
usleep_range(1000, 2000);
gpio_set_value(trf->en_gpio, 1);
/* The delay between enabling the trf7970a and issuing the first
* command is significantly longer the very first time after powering
* up. Make sure the longer delay is only done the first time.
*/
if (trf->powering_up) {
delay = 20000;
trf->powering_up = false;
} else {
delay = 5000;
}
usleep_range(delay, delay + 1000);
ret = trf7970a_init(trf);
if (ret)
trf7970a_switch_rf_off(trf);
else
trf->state = TRF7970A_ST_IDLE;
return ret;
}
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_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);
}
} else {
switch (trf->state) {
case TRF7970A_ST_OFF:
break;
default:
dev_err(trf->dev, "%s - Invalid request: %d %d\n",
__func__, trf->state, on);
/* FALLTHROUGH */
case TRF7970A_ST_IDLE:
case TRF7970A_ST_IDLE_RX_BLOCKED:
trf7970a_switch_rf_off(trf);
}
}
mutex_unlock(&trf->lock);
return ret;
}
static int trf7970a_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 = TRF7970A_ISO_CTRL_14443A_106;
break;
case NFC_DIGITAL_RF_TECH_ISO15693:
trf->iso_ctrl = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
break;
default:
dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
return -EINVAL;
}
trf->technology = tech;
return ret;
}
static int trf7970a_config_framing(struct trf7970a *trf, int framing)
{
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;
trf->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_ISO15693_INVENTORY:
case NFC_DIGITAL_FRAMING_ISO15693_T5T:
trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
trf->iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
break;
case NFC_DIGITAL_FRAMING_NFCA_T2T:
trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
trf->iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
break;
default:
dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
return -EINVAL;
}
trf->framing = framing;
return trf7970a_write(trf, TRF7970A_ISO_CTRL, trf->iso_ctrl);
}
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 = 0;
dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
mutex_lock(&trf->lock);
if (trf->state == TRF7970A_ST_OFF) {
ret = trf7970a_switch_rf_on(trf);
if (ret)
goto err_out;
}
switch (type) {
case NFC_DIGITAL_CONFIG_RF_TECH:
ret = trf7970a_config_rf_tech(trf, param);
break;
case NFC_DIGITAL_CONFIG_FRAMING:
ret = trf7970a_config_framing(trf, param);
break;
default:
dev_dbg(trf->dev, "Unknown type: %d\n", type);
ret = -EINVAL;
}
err_out:
mutex_unlock(&trf->lock);
return ret;
}
static int trf7970a_is_iso15693_write_or_lock(u8 cmd)
{
switch (cmd) {
case ISO15693_CMD_WRITE_SINGLE_BLOCK:
case ISO15693_CMD_LOCK_BLOCK:
case ISO15693_CMD_WRITE_MULTIPLE_BLOCK:
case ISO15693_CMD_WRITE_AFI:
case ISO15693_CMD_LOCK_AFI:
case ISO15693_CMD_WRITE_DSFID:
case ISO15693_CMD_LOCK_DSFID:
return 1;
break;
default:
return 0;
}
}
static int trf7970a_per_cmd_config(struct trf7970a *trf, struct sk_buff *skb)
{
u8 *req = skb->data;
u8 special_fcn_reg1, iso_ctrl;
int ret;
trf->issue_eof = false;
/* When issuing Type 2 read command, make sure the '4_bit_RX' bit in
* special functions register 1 is cleared; otherwise, its a write or
* sector select command and '4_bit_RX' must be set.
*
* When issuing an ISO 15693 command, inspect the flags byte to see
* what speed to use. Also, remember if the OPTION flag is set on
* a Type 5 write or lock command so the driver will know that it
* has to send an EOF in order to get a response.
*/
if ((trf->technology == NFC_DIGITAL_RF_TECH_106A) &&
(trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T)) {
if (req[0] == NFC_T2T_CMD_READ)
special_fcn_reg1 = 0;
else
special_fcn_reg1 = TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX;
if (special_fcn_reg1 != trf->special_fcn_reg1) {
ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1,
special_fcn_reg1);
if (ret)
return ret;
trf->special_fcn_reg1 = special_fcn_reg1;
}
} else if (trf->technology == NFC_DIGITAL_RF_TECH_ISO15693) {
iso_ctrl = trf->iso_ctrl & ~TRF7970A_ISO_CTRL_RFID_SPEED_MASK;
switch (req[0] & ISO15693_REQ_FLAG_SPEED_MASK) {
case 0x00:
iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_662;
break;
case ISO15693_REQ_FLAG_SUB_CARRIER:
iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a;
break;
case ISO15693_REQ_FLAG_DATA_RATE:
iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
break;
case (ISO15693_REQ_FLAG_SUB_CARRIER |
ISO15693_REQ_FLAG_DATA_RATE):
iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669;
break;
}
if (iso_ctrl != trf->iso_ctrl) {
ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
if (ret)
return ret;
trf->iso_ctrl = iso_ctrl;
}
if ((trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) &&
trf7970a_is_iso15693_write_or_lock(req[1]) &&
(req[0] & ISO15693_REQ_FLAG_OPTION))
trf->issue_eof = true;
}
return 0;
}
static int trf7970a_in_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);
char *prefix;
unsigned int len;
int ret;
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;
}
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;
}
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;
prefix = skb_push(skb, TRF7970A_TX_SKB_HEADROOM);
/* 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.
*/
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);
usleep_range(1000, 2000);
ret = trf7970a_transmit(trf, skb, len);
if (ret) {
kfree_skb(trf->rx_skb);
trf->rx_skb = NULL;
}
out_err:
mutex_unlock(&trf->lock);
return ret;
}
static int trf7970a_tg_configure_hw(struct nfc_digital_dev *ddev,
int type, int param)
{
struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
dev_dbg(trf->dev, "Unsupported interface\n");
return -EINVAL;
}
static int trf7970a_tg_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);
dev_dbg(trf->dev, "Unsupported interface\n");
return -EINVAL;
}
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, "Unsupported interface\n");
return -EINVAL;
}
static int trf7970a_tg_listen_mdaa(struct nfc_digital_dev *ddev,
struct digital_tg_mdaa_params *mdaa_params,
u16 timeout, nfc_digital_cmd_complete_t cb, void *arg)
{
struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
dev_dbg(trf->dev, "Unsupported interface\n");
return -EINVAL;
}
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);
trf->aborting = true;
mutex_unlock(&trf->lock);
}
static struct nfc_digital_ops trf7970a_nfc_ops = {
.in_configure_hw = trf7970a_in_configure_hw,
.in_send_cmd = trf7970a_in_send_cmd,
.tg_configure_hw = trf7970a_tg_configure_hw,
.tg_send_cmd = trf7970a_tg_send_cmd,
.tg_listen = trf7970a_tg_listen,
.tg_listen_mdaa = trf7970a_tg_listen_mdaa,
.switch_rf = trf7970a_switch_rf,
.abort_cmd = trf7970a_abort_cmd,
};
static int trf7970a_probe(struct spi_device *spi)
{
struct device_node *np = spi->dev.of_node;
const struct spi_device_id *id = spi_get_device_id(spi);
struct trf7970a *trf;
int ret;
if (!np) {
dev_err(&spi->dev, "No Device Tree entry\n");
return -EINVAL;
}
trf = devm_kzalloc(&spi->dev, sizeof(*trf), GFP_KERNEL);
if (!trf)
return -ENOMEM;
trf->state = TRF7970A_ST_OFF;
trf->dev = &spi->dev;
trf->spi = spi;
trf->quirks = id->driver_data;
spi->mode = SPI_MODE_1;
spi->bits_per_word = 8;
/* There are two enable pins - both must be present */
trf->en_gpio = of_get_named_gpio(np, "ti,enable-gpios", 0);
if (!gpio_is_valid(trf->en_gpio)) {
dev_err(trf->dev, "No EN GPIO property\n");
return trf->en_gpio;
}
ret = devm_gpio_request_one(trf->dev, trf->en_gpio,
GPIOF_DIR_OUT | GPIOF_INIT_LOW, "EN");
if (ret) {
dev_err(trf->dev, "Can't request EN GPIO: %d\n", ret);
return ret;
}
trf->en2_gpio = of_get_named_gpio(np, "ti,enable-gpios", 1);
if (!gpio_is_valid(trf->en2_gpio)) {
dev_err(trf->dev, "No EN2 GPIO property\n");
return trf->en2_gpio;
}
ret = devm_gpio_request_one(trf->dev, trf->en2_gpio,
GPIOF_DIR_OUT | GPIOF_INIT_LOW, "EN2");
if (ret) {
dev_err(trf->dev, "Can't request EN2 GPIO: %d\n", ret);
return ret;
}
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;
}
trf->powering_up = true;
trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,
TRF7970A_SUPPORTED_PROTOCOLS,
NFC_DIGITAL_DRV_CAPS_IN_CRC, TRF7970A_TX_SKB_HEADROOM,
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);
ret = nfc_digital_register_device(trf->ddev);
if (ret) {
dev_err(trf->dev, "Can't register NFC digital device: %d\n",
ret);
goto err_free_ddev;
}
return 0;
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_switch_rf_off(trf);
trf7970a_init(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:
trf7970a_send_err_upstream(trf, -ECANCELED);
break;
default:
break;
}
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;
}
static const struct spi_device_id trf7970a_id_table[] = {
{ "trf7970a", TRF7970A_QUIRK_IRQ_STATUS_READ_ERRATA },
{ }
};
MODULE_DEVICE_TABLE(spi, trf7970a_id_table);
static struct spi_driver trf7970a_spi_driver = {
.probe = trf7970a_probe,
.remove = trf7970a_remove,
.id_table = trf7970a_id_table,
.driver = {
.name = "trf7970a",
.owner = THIS_MODULE,
},
};
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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