[PATCH 1/3] NFC: trf7970a: Add driver with ISO/IEC 14443 Type 2 Tag Support

Mark A. Greer
2014-01-31T22:17:28Z

Add a driver for the Texas Instruments TRF7970a RFID/NFC/15693
transceiver. The driver currently supports ISO/IEC 14443 Type 2
tags only (MIFARE Ultralight and Ultralight C but not Classic).

CC: Erick Macias <emacias@ti.com>
CC: Felipe Balbi <balbi@ti.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
---
drivers/nfc/Kconfig | 12 +
drivers/nfc/Makefile | 1 +
drivers/nfc/trf7970a.c | 1191 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 1204 insertions(+)
create mode 100644 drivers/nfc/trf7970a.c

diff --git a/drivers/nfc/Kconfig b/drivers/nfc/Kconfig
index fe20e1c..65d4ca1 100644
--- a/drivers/nfc/Kconfig
+++ b/drivers/nfc/Kconfig
@@ -26,6 +26,18 @@ config NFC_WILINK
Say Y here to compile support for Texas Instrument's NFC WiLink driver
into the kernel or say M to compile it as module.

+config NFC_TRF7970A
+ tristate "Texas Instruments TRF7970a NFC driver"
+ depends on SPI && NFC_DIGITAL
+ help
+ This option enables the NFC driver for Texas Instruments' TRF7970a
+ device. Such device supports 5 different protocols: ISO14443A,
+ ISO14443B, FeLiCa, ISO15693 and ISO18000-3.
+
+ Say Y here to compile support for TRF7970a into the kernel or
+ say M to compile it as a module. The module will be called
+ trf7970a.ko.
+
config NFC_MEI_PHY
tristate "MEI bus NFC device support"
depends on INTEL_MEI && NFC_HCI
diff --git a/drivers/nfc/Makefile b/drivers/nfc/Makefile
index 56ab822..ae42a3f 100644
--- a/drivers/nfc/Makefile
+++ b/drivers/nfc/Makefile
@@ -10,5 +10,6 @@ obj-$(CONFIG_NFC_MEI_PHY) += mei_phy.o
obj-$(CONFIG_NFC_SIM) += nfcsim.o
obj-$(CONFIG_NFC_PORT100) += port100.o
obj-$(CONFIG_NFC_MRVL) += nfcmrvl/
+obj-$(CONFIG_NFC_TRF7970A) += trf7970a.o

ccflags-$(CONFIG_NFC_DEBUG) := -DDEBUG
diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c
new file mode 100644
index 0000000..7b9cfec
--- /dev/null
+++ b/drivers/nfc/trf7970a.c
@@ -0,0 +1,1191 @@
+/*
+ * 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 <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.
+ * When the "ti,ss-gpio" device tree property is present, SPI with
+ * SS mode is used; otherwise, SPI without SS mode is used.
+ *
+ * The trf7970a is very timing sensitive and the SS (I/O_4), EN2,
+ * and EN pins must enabled 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.
+ *
+ * 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 3 ms in case more
+ * data arrives. After 3 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 3 ms since delays
+ * over 2 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.
+ */
+
+#define TRF7970A_SUPPORTED_PROTOCOLS NFC_PROTO_MIFARE_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 3
+#define TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT 3
+
+/* 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
+
+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_MAX
+};
+
+struct trf7970a {
+ enum trf7970a_state state;
+ struct device *dev;
+ struct spi_device *spi;
+ struct nfc_digital_dev *ddev;
+ u32 quirks;
+ bool initialized;
+ 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;
+ int ss_gpio;
+ 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, %d)\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_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->state = TRF7970A_ST_OFF;
+}
+
+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;
+
+ trf->state = TRF7970A_ST_IDLE;
+
+ return 0;
+
+err_out:
+ dev_dbg(trf->dev, "Couldn't init device: %d\n", ret);
+
+ trf7970a_switch_rf_off(trf);
+ return ret;
+}
+
+static int trf7970a_switch_rf_on(struct trf7970a *trf)
+{
+ unsigned long delay;
+
+ dev_dbg(trf->dev, "Switching rf on\n");
+
+ 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->initialized) {
+ delay = 20000;
+ trf->initialized = true;
+ } else {
+ delay = 5000;
+ }
+
+ usleep_range(delay, delay + 1000);
+
+ return trf7970a_init(trf);
+}
+
+static void _trf7970a_abort_cmd(struct trf7970a *trf)
+{
+ dev_dbg(trf->dev, "Aborting cmd - state: %d\n", trf->state);
+
+ if ((trf->state != TRF7970A_ST_IDLE) &&
+ (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED))
+ trf->ignore_timeout = !cancel_delayed_work(&trf->timeout_work);
+
+ trf7970a_init(trf);
+
+ dev_kfree_skb_any(trf->tx_skb);
+ trf->tx_skb = NULL;
+
+ kfree_skb(trf->rx_skb);
+ trf->rx_skb = NULL;
+
+ trf->state = TRF7970A_ST_IDLE; /* In case trf7970a_init() fails */
+}
+
+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))
+ 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->cb(trf->ddev, trf->cb_arg, trf->rx_skb);
+ trf->rx_skb = NULL;
+
+ trf->state = TRF7970A_ST_IDLE;
+}
+
+static void trf7970a_abort_and_send_err(struct trf7970a *trf, int errno)
+{
+ dev_dbg(trf->dev, "Error - state: %d, errno: %d\n", trf->state, errno);
+
+ _trf7970a_abort_cmd(trf);
+
+ 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 {
+ 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_abort_and_send_err(trf, ret);
+ return;
+ }
+
+ dev_dbg(trf->dev, "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_abort_and_send_err(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_abort_and_send_err(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_abort_and_send_err(trf, -EIO);
+ return;
+ }
+
+ ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
+ if (ret) {
+ trf7970a_abort_and_send_err(trf, ret);
+ return;
+ }
+
+ dev_dbg(trf->dev, "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_abort_and_send_err(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_abort_and_send_err(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_abort_and_send_err(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_abort_and_send_err(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_abort_and_send_err(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_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
+ trf7970a_abort_and_send_err(trf, -ETIMEDOUT);
+
+ mutex_unlock(&trf->lock);
+}
+
+/* ----------------------------------------------------------------- */
+
+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;
+ 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:
+ 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_per_cmd_config(struct trf7970a *trf, struct sk_buff *skb)
+{
+ u8 *req = skb->data;
+ u8 special_fcn_reg1;
+ int ret;
+
+ /* 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.
+ */
+ 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;
+ }
+ }
+
+ 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;
+ }
+
+ 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 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, "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 void trf7970a_abort_cmd(struct nfc_digital_dev *ddev)
+{
+ struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
+
+ mutex_lock(&trf->lock);
+ _trf7970a_abort_cmd(trf);
+ 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;
+ trf->initialized = false;
+
+ spi->mode = SPI_MODE_1;
+ spi->bits_per_word = 8;
+
+ /* Get the optional Slave Select GPIO used for SPI with SS mode */
+ trf->ss_gpio = of_get_named_gpio(np, "ti,ss-gpio", 0);
+ if (trf->ss_gpio >= 0) {
+ ret = devm_gpio_request_one(trf->dev, trf->ss_gpio,
+ GPIOF_DIR_OUT | GPIOF_INIT_LOW, "SS");
+ if (ret) {
+ dev_err(trf->dev, "Can't request SS GPIO: %d\n", ret);
+ return ret;
+ }
+ } else {
+ dev_info(trf->dev, "Using SPI without SS mode\n");
+ }
+
+ /* There are two enable pins - both must be present */
+ trf->en_gpio = of_get_named_gpio(np, "ti,enable-gpios", 0);
+ if (trf->en_gpio < 0) {
+ dev_err(trf->dev, "No EN GPIO property\n");
+ return ret;
+ }
+
+ 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 (trf->en2_gpio < 0) {
+ dev_err(trf->dev, "No EN2 GPIO property\n");
+ return ret;
+ }
+
+ 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;
+ }
+
+ usleep_range(2000, 3000);
+ if (trf->ss_gpio >= 0)
+ gpio_set_value(trf->ss_gpio, 1);
+ usleep_range(3000, 4000);
+
+ 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;
+ }
+
+ 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");
+ return -ENOMEM;
+ }
+
+ 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;
+ }
+
+ mutex_init(&trf->lock);
+ INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
+
+ return 0;
+
+err_free_ddev:
+ nfc_digital_free_device(trf->ddev);
+ return ret;
+}
+
+static int trf7970a_remove(struct spi_device *spi)
+{
+ struct trf7970a *trf = spi_get_drvdata(spi);
+
+ _trf7970a_abort_cmd(trf);
+ trf7970a_switch_rf_off(trf);
+
+ if (trf->ss_gpio >= 0)
+ gpio_set_value(trf->ss_gpio, 0);
+
+ mutex_destroy(&trf->lock);
+
+ nfc_digital_unregister_device(trf->ddev);
+ nfc_digital_free_device(trf->ddev);
+
+ 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");
--
1.8.3.4