drivers/nfc/trf7970a.c

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This source file includes following definitions.
trf7970a_cmd
trf7970a_read
trf7970a_read_cont
trf7970a_write
trf7970a_read_irqstatus
trf7970a_read_target_proto
trf7970a_mode_detect
trf7970a_send_upstream
trf7970a_send_err_upstream
trf7970a_transmit
trf7970a_fill_fifo
trf7970a_drain_fifo
trf7970a_irq
trf7970a_issue_eof
trf7970a_timeout_work_handler
trf7970a_init
trf7970a_switch_rf_off
trf7970a_switch_rf_on
trf7970a_switch_rf
trf7970a_in_config_rf_tech
trf7970a_is_rf_field
trf7970a_in_config_framing
trf7970a_in_configure_hw
trf7970a_is_iso15693_write_or_lock
trf7970a_per_cmd_config
trf7970a_send_cmd
trf7970a_tg_config_rf_tech
trf7970a_tg_config_framing
trf7970a_tg_configure_hw
_trf7970a_tg_listen
trf7970a_tg_listen
trf7970a_tg_listen_md
trf7970a_tg_get_rf_tech
trf7970a_abort_cmd
trf7970a_power_up
trf7970a_power_down
trf7970a_startup
trf7970a_shutdown
trf7970a_get_autosuspend_delay
trf7970a_probe
trf7970a_remove
trf7970a_suspend
trf7970a_resume
trf7970a_pm_runtime_suspend
trf7970a_pm_runtime_resume
   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * TI TRF7970a RFID/NFC Transceiver Driver
   4  *
   5  * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
   6  *
   7  * Author: Erick Macias <emacias@ti.com>
   8  * Author: Felipe Balbi <balbi@ti.com>
   9  * Author: Mark A. Greer <mgreer@animalcreek.com>
  10  */
  11 
  12 #include <linux/module.h>
  13 #include <linux/device.h>
  14 #include <linux/netdevice.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/pm_runtime.h>
  17 #include <linux/nfc.h>
  18 #include <linux/skbuff.h>
  19 #include <linux/delay.h>
  20 #include <linux/gpio/consumer.h>
  21 #include <linux/of.h>
  22 #include <linux/spi/spi.h>
  23 #include <linux/regulator/consumer.h>
  24 
  25 #include <net/nfc/nfc.h>
  26 #include <net/nfc/digital.h>
  27 
  28 /* There are 3 ways the host can communicate with the trf7970a:
  29  * parallel mode, SPI with Slave Select (SS) mode, and SPI without
  30  * SS mode.  The driver only supports the two SPI modes.
  31  *
  32  * The trf7970a is very timing sensitive and the VIN, EN2, and EN
  33  * pins must asserted in that order and with specific delays in between.
  34  * The delays used in the driver were provided by TI and have been
  35  * confirmed to work with this driver.  There is a bug with the current
  36  * version of the trf7970a that requires that EN2 remain low no matter
  37  * what.  If it goes high, it will generate an RF field even when in
  38  * passive target mode.  TI has indicated that the chip will work okay
  39  * when EN2 is left low.  The 'en2-rf-quirk' device tree property
  40  * indicates that trf7970a currently being used has the erratum and
  41  * that EN2 must be kept low.
  42  *
  43  * Timeouts are implemented using the delayed workqueue kernel facility.
  44  * Timeouts are required so things don't hang when there is no response
  45  * from the trf7970a (or tag).  Using this mechanism creates a race with
  46  * interrupts, however.  That is, an interrupt and a timeout could occur
  47  * closely enough together that one is blocked by the mutex while the other
  48  * executes.  When the timeout handler executes first and blocks the
  49  * interrupt handler, it will eventually set the state to IDLE so the
  50  * interrupt handler will check the state and exit with no harm done.
  51  * When the interrupt handler executes first and blocks the timeout handler,
  52  * the cancel_delayed_work() call will know that it didn't cancel the
  53  * work item (i.e., timeout) and will return zero.  That return code is
  54  * used by the timer handler to indicate that it should ignore the timeout
  55  * once its unblocked.
  56  *
  57  * Aborting an active command isn't as simple as it seems because the only
  58  * way to abort a command that's already been sent to the tag is so turn
  59  * off power to the tag.  If we do that, though, we'd have to go through
  60  * the entire anticollision procedure again but the digital layer doesn't
  61  * support that.  So, if an abort is received before trf7970a_send_cmd()
  62  * has sent the command to the tag, it simply returns -ECANCELED.  If the
  63  * command has already been sent to the tag, then the driver continues
  64  * normally and recieves the response data (or error) but just before
  65  * sending the data upstream, it frees the rx_skb and sends -ECANCELED
  66  * upstream instead.  If the command failed, that error will be sent
  67  * upstream.
  68  *
  69  * When recieving data from a tag and the interrupt status register has
  70  * only the SRX bit set, it means that all of the data has been received
  71  * (once what's in the fifo has been read).  However, depending on timing
  72  * an interrupt status with only the SRX bit set may not be recived.  In
  73  * those cases, the timeout mechanism is used to wait 20 ms in case more
  74  * data arrives.  After 20 ms, it is assumed that all of the data has been
  75  * received and the accumulated rx data is sent upstream.  The
  76  * 'TRF7970A_ST_WAIT_FOR_RX_DATA_CONT' state is used for this purpose
  77  * (i.e., it indicates that some data has been received but we're not sure
  78  * if there is more coming so a timeout in this state means all data has
  79  * been received and there isn't an error).  The delay is 20 ms since delays
  80  * of ~16 ms have been observed during testing.
  81  *
  82  * When transmitting a frame larger than the FIFO size (127 bytes), the
  83  * driver will wait 20 ms for the FIFO to drain past the low-watermark
  84  * and generate an interrupt.  The low-watermark set to 32 bytes so the
  85  * interrupt should fire after 127 - 32 = 95 bytes have been sent.  At
  86  * the lowest possible bit rate (6.62 kbps for 15693), it will take up
  87  * to ~14.35 ms so 20 ms is used for the timeout.
  88  *
  89  * Type 2 write and sector select commands respond with a 4-bit ACK or NACK.
  90  * Having only 4 bits in the FIFO won't normally generate an interrupt so
  91  * driver enables the '4_bit_RX' bit of the Special Functions register 1
  92  * to cause an interrupt in that case.  Leaving that bit for a read command
  93  * messes up the data returned so it is only enabled when the framing is
  94  * 'NFC_DIGITAL_FRAMING_NFCA_T2T' and the command is not a read command.
  95  * Unfortunately, that means that the driver has to peek into tx frames
  96  * when the framing is 'NFC_DIGITAL_FRAMING_NFCA_T2T'.  This is done by
  97  * the trf7970a_per_cmd_config() routine.
  98  *
  99  * ISO/IEC 15693 frames specify whether to use single or double sub-carrier
 100  * frequencies and whether to use low or high data rates in the flags byte
 101  * of the frame.  This means that the driver has to peek at all 15693 frames
 102  * to determine what speed to set the communication to.  In addition, write
 103  * and lock commands use the OPTION flag to indicate that an EOF must be
 104  * sent to the tag before it will send its response.  So the driver has to
 105  * examine all frames for that reason too.
 106  *
 107  * It is unclear how long to wait before sending the EOF.  According to the
 108  * Note under Table 1-1 in section 1.6 of
 109  * http://www.ti.com/lit/ug/scbu011/scbu011.pdf, that wait should be at least
 110  * 10 ms for TI Tag-it HF-I tags; however testing has shown that is not long
 111  * enough so 20 ms is used.  So the timer is set to 40 ms - 20 ms to drain
 112  * up to 127 bytes in the FIFO at the lowest bit rate plus another 20 ms to
 113  * ensure the wait is long enough before sending the EOF.  This seems to work
 114  * reliably.
 115  */
 116 
 117 #define TRF7970A_SUPPORTED_PROTOCOLS \
 118                 (NFC_PROTO_MIFARE_MASK | NFC_PROTO_ISO14443_MASK |      \
 119                  NFC_PROTO_ISO14443_B_MASK | NFC_PROTO_FELICA_MASK | \
 120                  NFC_PROTO_ISO15693_MASK | NFC_PROTO_NFC_DEP_MASK)
 121 
 122 #define TRF7970A_AUTOSUSPEND_DELAY              30000   /* 30 seconds */
 123 #define TRF7970A_13MHZ_CLOCK_FREQUENCY          13560000
 124 #define TRF7970A_27MHZ_CLOCK_FREQUENCY          27120000
 125 
 126 #define TRF7970A_RX_SKB_ALLOC_SIZE              256
 127 
 128 #define TRF7970A_FIFO_SIZE                      127
 129 
 130 /* TX length is 3 nibbles long ==> 4KB - 1 bytes max */
 131 #define TRF7970A_TX_MAX                         (4096 - 1)
 132 
 133 #define TRF7970A_WAIT_FOR_TX_IRQ                20
 134 #define TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT       20
 135 #define TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT    20
 136 #define TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF     40
 137 
 138 /* Guard times for various RF technologies (in us) */
 139 #define TRF7970A_GUARD_TIME_NFCA                5000
 140 #define TRF7970A_GUARD_TIME_NFCB                5000
 141 #define TRF7970A_GUARD_TIME_NFCF                20000
 142 #define TRF7970A_GUARD_TIME_15693               1000
 143 
 144 /* Quirks */
 145 /* Erratum: When reading IRQ Status register on trf7970a, we must issue a
 146  * read continuous command for IRQ Status and Collision Position registers.
 147  */
 148 #define TRF7970A_QUIRK_IRQ_STATUS_READ          BIT(0)
 149 #define TRF7970A_QUIRK_EN2_MUST_STAY_LOW        BIT(1)
 150 
 151 /* Direct commands */
 152 #define TRF7970A_CMD_IDLE                       0x00
 153 #define TRF7970A_CMD_SOFT_INIT                  0x03
 154 #define TRF7970A_CMD_RF_COLLISION               0x04
 155 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_N    0x05
 156 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_0    0x06
 157 #define TRF7970A_CMD_FIFO_RESET                 0x0f
 158 #define TRF7970A_CMD_TRANSMIT_NO_CRC            0x10
 159 #define TRF7970A_CMD_TRANSMIT                   0x11
 160 #define TRF7970A_CMD_DELAY_TRANSMIT_NO_CRC      0x12
 161 #define TRF7970A_CMD_DELAY_TRANSMIT             0x13
 162 #define TRF7970A_CMD_EOF                        0x14
 163 #define TRF7970A_CMD_CLOSE_SLOT                 0x15
 164 #define TRF7970A_CMD_BLOCK_RX                   0x16
 165 #define TRF7970A_CMD_ENABLE_RX                  0x17
 166 #define TRF7970A_CMD_TEST_INT_RF                0x18
 167 #define TRF7970A_CMD_TEST_EXT_RF                0x19
 168 #define TRF7970A_CMD_RX_GAIN_ADJUST             0x1a
 169 
 170 /* Bits determining whether its a direct command or register R/W,
 171  * whether to use a continuous SPI transaction or not, and the actual
 172  * direct cmd opcode or regster address.
 173  */
 174 #define TRF7970A_CMD_BIT_CTRL                   BIT(7)
 175 #define TRF7970A_CMD_BIT_RW                     BIT(6)
 176 #define TRF7970A_CMD_BIT_CONTINUOUS             BIT(5)
 177 #define TRF7970A_CMD_BIT_OPCODE(opcode)         ((opcode) & 0x1f)
 178 
 179 /* Registers addresses */
 180 #define TRF7970A_CHIP_STATUS_CTRL               0x00
 181 #define TRF7970A_ISO_CTRL                       0x01
 182 #define TRF7970A_ISO14443B_TX_OPTIONS           0x02
 183 #define TRF7970A_ISO14443A_HIGH_BITRATE_OPTIONS 0x03
 184 #define TRF7970A_TX_TIMER_SETTING_H_BYTE        0x04
 185 #define TRF7970A_TX_TIMER_SETTING_L_BYTE        0x05
 186 #define TRF7970A_TX_PULSE_LENGTH_CTRL           0x06
 187 #define TRF7970A_RX_NO_RESPONSE_WAIT            0x07
 188 #define TRF7970A_RX_WAIT_TIME                   0x08
 189 #define TRF7970A_MODULATOR_SYS_CLK_CTRL         0x09
 190 #define TRF7970A_RX_SPECIAL_SETTINGS            0x0a
 191 #define TRF7970A_REG_IO_CTRL                    0x0b
 192 #define TRF7970A_IRQ_STATUS                     0x0c
 193 #define TRF7970A_COLLISION_IRQ_MASK             0x0d
 194 #define TRF7970A_COLLISION_POSITION             0x0e
 195 #define TRF7970A_RSSI_OSC_STATUS                0x0f
 196 #define TRF7970A_SPECIAL_FCN_REG1               0x10
 197 #define TRF7970A_SPECIAL_FCN_REG2               0x11
 198 #define TRF7970A_RAM1                           0x12
 199 #define TRF7970A_RAM2                           0x13
 200 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS      0x14
 201 #define TRF7970A_NFC_LOW_FIELD_LEVEL            0x16
 202 #define TRF7970A_NFCID1                         0x17
 203 #define TRF7970A_NFC_TARGET_LEVEL               0x18
 204 #define TRF79070A_NFC_TARGET_PROTOCOL           0x19
 205 #define TRF7970A_TEST_REGISTER1                 0x1a
 206 #define TRF7970A_TEST_REGISTER2                 0x1b
 207 #define TRF7970A_FIFO_STATUS                    0x1c
 208 #define TRF7970A_TX_LENGTH_BYTE1                0x1d
 209 #define TRF7970A_TX_LENGTH_BYTE2                0x1e
 210 #define TRF7970A_FIFO_IO_REGISTER               0x1f
 211 
 212 /* Chip Status Control Register Bits */
 213 #define TRF7970A_CHIP_STATUS_VRS5_3             BIT(0)
 214 #define TRF7970A_CHIP_STATUS_REC_ON             BIT(1)
 215 #define TRF7970A_CHIP_STATUS_AGC_ON             BIT(2)
 216 #define TRF7970A_CHIP_STATUS_PM_ON              BIT(3)
 217 #define TRF7970A_CHIP_STATUS_RF_PWR             BIT(4)
 218 #define TRF7970A_CHIP_STATUS_RF_ON              BIT(5)
 219 #define TRF7970A_CHIP_STATUS_DIRECT             BIT(6)
 220 #define TRF7970A_CHIP_STATUS_STBY               BIT(7)
 221 
 222 /* ISO Control Register Bits */
 223 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_662    0x00
 224 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_662  0x01
 225 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648   0x02
 226 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_2648 0x03
 227 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a   0x04
 228 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_667  0x05
 229 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669   0x06
 230 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_2669 0x07
 231 #define TRF7970A_ISO_CTRL_14443A_106            0x08
 232 #define TRF7970A_ISO_CTRL_14443A_212            0x09
 233 #define TRF7970A_ISO_CTRL_14443A_424            0x0a
 234 #define TRF7970A_ISO_CTRL_14443A_848            0x0b
 235 #define TRF7970A_ISO_CTRL_14443B_106            0x0c
 236 #define TRF7970A_ISO_CTRL_14443B_212            0x0d
 237 #define TRF7970A_ISO_CTRL_14443B_424            0x0e
 238 #define TRF7970A_ISO_CTRL_14443B_848            0x0f
 239 #define TRF7970A_ISO_CTRL_FELICA_212            0x1a
 240 #define TRF7970A_ISO_CTRL_FELICA_424            0x1b
 241 #define TRF7970A_ISO_CTRL_NFC_NFCA_106          0x01
 242 #define TRF7970A_ISO_CTRL_NFC_NFCF_212          0x02
 243 #define TRF7970A_ISO_CTRL_NFC_NFCF_424          0x03
 244 #define TRF7970A_ISO_CTRL_NFC_CE_14443A         0x00
 245 #define TRF7970A_ISO_CTRL_NFC_CE_14443B         0x01
 246 #define TRF7970A_ISO_CTRL_NFC_CE                BIT(2)
 247 #define TRF7970A_ISO_CTRL_NFC_ACTIVE            BIT(3)
 248 #define TRF7970A_ISO_CTRL_NFC_INITIATOR         BIT(4)
 249 #define TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE       BIT(5)
 250 #define TRF7970A_ISO_CTRL_RFID                  BIT(5)
 251 #define TRF7970A_ISO_CTRL_DIR_MODE              BIT(6)
 252 #define TRF7970A_ISO_CTRL_RX_CRC_N              BIT(7)  /* true == No CRC */
 253 
 254 #define TRF7970A_ISO_CTRL_RFID_SPEED_MASK       0x1f
 255 
 256 /* Modulator and SYS_CLK Control Register Bits */
 257 #define TRF7970A_MODULATOR_DEPTH(n)             ((n) & 0x7)
 258 #define TRF7970A_MODULATOR_DEPTH_ASK10          (TRF7970A_MODULATOR_DEPTH(0))
 259 #define TRF7970A_MODULATOR_DEPTH_OOK            (TRF7970A_MODULATOR_DEPTH(1))
 260 #define TRF7970A_MODULATOR_DEPTH_ASK7           (TRF7970A_MODULATOR_DEPTH(2))
 261 #define TRF7970A_MODULATOR_DEPTH_ASK8_5         (TRF7970A_MODULATOR_DEPTH(3))
 262 #define TRF7970A_MODULATOR_DEPTH_ASK13          (TRF7970A_MODULATOR_DEPTH(4))
 263 #define TRF7970A_MODULATOR_DEPTH_ASK16          (TRF7970A_MODULATOR_DEPTH(5))
 264 #define TRF7970A_MODULATOR_DEPTH_ASK22          (TRF7970A_MODULATOR_DEPTH(6))
 265 #define TRF7970A_MODULATOR_DEPTH_ASK30          (TRF7970A_MODULATOR_DEPTH(7))
 266 #define TRF7970A_MODULATOR_EN_ANA               BIT(3)
 267 #define TRF7970A_MODULATOR_CLK(n)               (((n) & 0x3) << 4)
 268 #define TRF7970A_MODULATOR_CLK_DISABLED         (TRF7970A_MODULATOR_CLK(0))
 269 #define TRF7970A_MODULATOR_CLK_3_6              (TRF7970A_MODULATOR_CLK(1))
 270 #define TRF7970A_MODULATOR_CLK_6_13             (TRF7970A_MODULATOR_CLK(2))
 271 #define TRF7970A_MODULATOR_CLK_13_27            (TRF7970A_MODULATOR_CLK(3))
 272 #define TRF7970A_MODULATOR_EN_OOK               BIT(6)
 273 #define TRF7970A_MODULATOR_27MHZ                BIT(7)
 274 
 275 #define TRF7970A_RX_SPECIAL_SETTINGS_NO_LIM     BIT(0)
 276 #define TRF7970A_RX_SPECIAL_SETTINGS_AGCR       BIT(1)
 277 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_0DB     (0x0 << 2)
 278 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_5DB     (0x1 << 2)
 279 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_10DB    (0x2 << 2)
 280 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_15DB    (0x3 << 2)
 281 #define TRF7970A_RX_SPECIAL_SETTINGS_HBT        BIT(4)
 282 #define TRF7970A_RX_SPECIAL_SETTINGS_M848       BIT(5)
 283 #define TRF7970A_RX_SPECIAL_SETTINGS_C424       BIT(6)
 284 #define TRF7970A_RX_SPECIAL_SETTINGS_C212       BIT(7)
 285 
 286 #define TRF7970A_REG_IO_CTRL_VRS(v)             ((v) & 0x07)
 287 #define TRF7970A_REG_IO_CTRL_IO_LOW             BIT(5)
 288 #define TRF7970A_REG_IO_CTRL_EN_EXT_PA          BIT(6)
 289 #define TRF7970A_REG_IO_CTRL_AUTO_REG           BIT(7)
 290 
 291 /* IRQ Status Register Bits */
 292 #define TRF7970A_IRQ_STATUS_NORESP              BIT(0)  /* ISO15693 only */
 293 #define TRF7970A_IRQ_STATUS_NFC_COL_ERROR       BIT(0)
 294 #define TRF7970A_IRQ_STATUS_COL                 BIT(1)
 295 #define TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR   BIT(2)
 296 #define TRF7970A_IRQ_STATUS_NFC_RF              BIT(2)
 297 #define TRF7970A_IRQ_STATUS_PARITY_ERROR        BIT(3)
 298 #define TRF7970A_IRQ_STATUS_NFC_SDD             BIT(3)
 299 #define TRF7970A_IRQ_STATUS_CRC_ERROR           BIT(4)
 300 #define TRF7970A_IRQ_STATUS_NFC_PROTO_ERROR     BIT(4)
 301 #define TRF7970A_IRQ_STATUS_FIFO                BIT(5)
 302 #define TRF7970A_IRQ_STATUS_SRX                 BIT(6)
 303 #define TRF7970A_IRQ_STATUS_TX                  BIT(7)
 304 
 305 #define TRF7970A_IRQ_STATUS_ERROR                               \
 306                 (TRF7970A_IRQ_STATUS_COL |                      \
 307                  TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR |        \
 308                  TRF7970A_IRQ_STATUS_PARITY_ERROR |             \
 309                  TRF7970A_IRQ_STATUS_CRC_ERROR)
 310 
 311 #define TRF7970A_RSSI_OSC_STATUS_RSSI_MASK      (BIT(2) | BIT(1) | BIT(0))
 312 #define TRF7970A_RSSI_OSC_STATUS_RSSI_X_MASK    (BIT(5) | BIT(4) | BIT(3))
 313 #define TRF7970A_RSSI_OSC_STATUS_RSSI_OSC_OK    BIT(6)
 314 
 315 #define TRF7970A_SPECIAL_FCN_REG1_COL_7_6               BIT(0)
 316 #define TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL           BIT(1)
 317 #define TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX              BIT(2)
 318 #define TRF7970A_SPECIAL_FCN_REG1_SP_DIR_MODE           BIT(3)
 319 #define TRF7970A_SPECIAL_FCN_REG1_NEXT_SLOT_37US        BIT(4)
 320 #define TRF7970A_SPECIAL_FCN_REG1_PAR43                 BIT(5)
 321 
 322 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_124      (0x0 << 2)
 323 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_120      (0x1 << 2)
 324 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_112      (0x2 << 2)
 325 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96       (0x3 << 2)
 326 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_4        0x0
 327 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_8        0x1
 328 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_16       0x2
 329 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32       0x3
 330 
 331 #define TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(v)   ((v) & 0x07)
 332 #define TRF7970A_NFC_LOW_FIELD_LEVEL_CLEX_DIS   BIT(7)
 333 
 334 #define TRF7970A_NFC_TARGET_LEVEL_RFDET(v)      ((v) & 0x07)
 335 #define TRF7970A_NFC_TARGET_LEVEL_HI_RF         BIT(3)
 336 #define TRF7970A_NFC_TARGET_LEVEL_SDD_EN        BIT(5)
 337 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_4BYTES   (0x0 << 6)
 338 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_7BYTES   (0x1 << 6)
 339 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_10BYTES  (0x2 << 6)
 340 
 341 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106         BIT(0)
 342 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212         BIT(1)
 343 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424         (BIT(0) | BIT(1))
 344 #define TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B        BIT(2)
 345 #define TRF79070A_NFC_TARGET_PROTOCOL_PAS_106           BIT(3)
 346 #define TRF79070A_NFC_TARGET_PROTOCOL_FELICA            BIT(4)
 347 #define TRF79070A_NFC_TARGET_PROTOCOL_RF_L              BIT(6)
 348 #define TRF79070A_NFC_TARGET_PROTOCOL_RF_H              BIT(7)
 349 
 350 #define TRF79070A_NFC_TARGET_PROTOCOL_106A              \
 351          (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |          \
 352           TRF79070A_NFC_TARGET_PROTOCOL_RF_L |          \
 353           TRF79070A_NFC_TARGET_PROTOCOL_PAS_106 |       \
 354           TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
 355 
 356 #define TRF79070A_NFC_TARGET_PROTOCOL_106B              \
 357          (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |          \
 358           TRF79070A_NFC_TARGET_PROTOCOL_RF_L |          \
 359           TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B |    \
 360           TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
 361 
 362 #define TRF79070A_NFC_TARGET_PROTOCOL_212F              \
 363          (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |          \
 364           TRF79070A_NFC_TARGET_PROTOCOL_RF_L |          \
 365           TRF79070A_NFC_TARGET_PROTOCOL_FELICA |        \
 366           TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212)
 367 
 368 #define TRF79070A_NFC_TARGET_PROTOCOL_424F              \
 369          (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |          \
 370           TRF79070A_NFC_TARGET_PROTOCOL_RF_L |          \
 371           TRF79070A_NFC_TARGET_PROTOCOL_FELICA |        \
 372           TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424)
 373 
 374 #define TRF7970A_FIFO_STATUS_OVERFLOW           BIT(7)
 375 
 376 /* NFC (ISO/IEC 14443A) Type 2 Tag commands */
 377 #define NFC_T2T_CMD_READ                        0x30
 378 
 379 /* ISO 15693 commands codes */
 380 #define ISO15693_CMD_INVENTORY                  0x01
 381 #define ISO15693_CMD_READ_SINGLE_BLOCK          0x20
 382 #define ISO15693_CMD_WRITE_SINGLE_BLOCK         0x21
 383 #define ISO15693_CMD_LOCK_BLOCK                 0x22
 384 #define ISO15693_CMD_READ_MULTIPLE_BLOCK        0x23
 385 #define ISO15693_CMD_WRITE_MULTIPLE_BLOCK       0x24
 386 #define ISO15693_CMD_SELECT                     0x25
 387 #define ISO15693_CMD_RESET_TO_READY             0x26
 388 #define ISO15693_CMD_WRITE_AFI                  0x27
 389 #define ISO15693_CMD_LOCK_AFI                   0x28
 390 #define ISO15693_CMD_WRITE_DSFID                0x29
 391 #define ISO15693_CMD_LOCK_DSFID                 0x2a
 392 #define ISO15693_CMD_GET_SYSTEM_INFO            0x2b
 393 #define ISO15693_CMD_GET_MULTIPLE_BLOCK_SECURITY_STATUS 0x2c
 394 
 395 /* ISO 15693 request and response flags */
 396 #define ISO15693_REQ_FLAG_SUB_CARRIER           BIT(0)
 397 #define ISO15693_REQ_FLAG_DATA_RATE             BIT(1)
 398 #define ISO15693_REQ_FLAG_INVENTORY             BIT(2)
 399 #define ISO15693_REQ_FLAG_PROTOCOL_EXT          BIT(3)
 400 #define ISO15693_REQ_FLAG_SELECT                BIT(4)
 401 #define ISO15693_REQ_FLAG_AFI                   BIT(4)
 402 #define ISO15693_REQ_FLAG_ADDRESS               BIT(5)
 403 #define ISO15693_REQ_FLAG_NB_SLOTS              BIT(5)
 404 #define ISO15693_REQ_FLAG_OPTION                BIT(6)
 405 
 406 #define ISO15693_REQ_FLAG_SPEED_MASK \
 407                 (ISO15693_REQ_FLAG_SUB_CARRIER | ISO15693_REQ_FLAG_DATA_RATE)
 408 
 409 enum trf7970a_state {
 410         TRF7970A_ST_PWR_OFF,
 411         TRF7970A_ST_RF_OFF,
 412         TRF7970A_ST_IDLE,
 413         TRF7970A_ST_IDLE_RX_BLOCKED,
 414         TRF7970A_ST_WAIT_FOR_TX_FIFO,
 415         TRF7970A_ST_WAIT_FOR_RX_DATA,
 416         TRF7970A_ST_WAIT_FOR_RX_DATA_CONT,
 417         TRF7970A_ST_WAIT_TO_ISSUE_EOF,
 418         TRF7970A_ST_LISTENING,
 419         TRF7970A_ST_LISTENING_MD,
 420         TRF7970A_ST_MAX
 421 };
 422 
 423 struct trf7970a {
 424         enum trf7970a_state             state;
 425         struct device                   *dev;
 426         struct spi_device               *spi;
 427         struct regulator                *regulator;
 428         struct nfc_digital_dev          *ddev;
 429         u32                             quirks;
 430         bool                            is_initiator;
 431         bool                            aborting;
 432         struct sk_buff                  *tx_skb;
 433         struct sk_buff                  *rx_skb;
 434         nfc_digital_cmd_complete_t      cb;
 435         void                            *cb_arg;
 436         u8                              chip_status_ctrl;
 437         u8                              iso_ctrl;
 438         u8                              iso_ctrl_tech;
 439         u8                              modulator_sys_clk_ctrl;
 440         u8                              special_fcn_reg1;
 441         u8                              io_ctrl;
 442         unsigned int                    guard_time;
 443         int                             technology;
 444         int                             framing;
 445         u8                              md_rf_tech;
 446         u8                              tx_cmd;
 447         bool                            issue_eof;
 448         struct gpio_desc                *en_gpiod;
 449         struct gpio_desc                *en2_gpiod;
 450         struct mutex                    lock;
 451         unsigned int                    timeout;
 452         bool                            ignore_timeout;
 453         struct delayed_work             timeout_work;
 454 };
 455 
 456 static int trf7970a_cmd(struct trf7970a *trf, u8 opcode)
 457 {
 458         u8 cmd = TRF7970A_CMD_BIT_CTRL | TRF7970A_CMD_BIT_OPCODE(opcode);
 459         int ret;
 460 
 461         dev_dbg(trf->dev, "cmd: 0x%x\n", cmd);
 462 
 463         ret = spi_write(trf->spi, &cmd, 1);
 464         if (ret)
 465                 dev_err(trf->dev, "%s - cmd: 0x%x, ret: %d\n", __func__, cmd,
 466                         ret);
 467         return ret;
 468 }
 469 
 470 static int trf7970a_read(struct trf7970a *trf, u8 reg, u8 *val)
 471 {
 472         u8 addr = TRF7970A_CMD_BIT_RW | reg;
 473         int ret;
 474 
 475         ret = spi_write_then_read(trf->spi, &addr, 1, val, 1);
 476         if (ret)
 477                 dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
 478                         ret);
 479 
 480         dev_dbg(trf->dev, "read(0x%x): 0x%x\n", addr, *val);
 481 
 482         return ret;
 483 }
 484 
 485 static int trf7970a_read_cont(struct trf7970a *trf, u8 reg, u8 *buf,
 486                               size_t len)
 487 {
 488         u8 addr = reg | TRF7970A_CMD_BIT_RW | TRF7970A_CMD_BIT_CONTINUOUS;
 489         struct spi_transfer t[2];
 490         struct spi_message m;
 491         int ret;
 492 
 493         dev_dbg(trf->dev, "read_cont(0x%x, %zd)\n", addr, len);
 494 
 495         spi_message_init(&m);
 496 
 497         memset(&t, 0, sizeof(t));
 498 
 499         t[0].tx_buf = &addr;
 500         t[0].len = sizeof(addr);
 501         spi_message_add_tail(&t[0], &m);
 502 
 503         t[1].rx_buf = buf;
 504         t[1].len = len;
 505         spi_message_add_tail(&t[1], &m);
 506 
 507         ret = spi_sync(trf->spi, &m);
 508         if (ret)
 509                 dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
 510                         ret);
 511         return ret;
 512 }
 513 
 514 static int trf7970a_write(struct trf7970a *trf, u8 reg, u8 val)
 515 {
 516         u8 buf[2] = { reg, val };
 517         int ret;
 518 
 519         dev_dbg(trf->dev, "write(0x%x): 0x%x\n", reg, val);
 520 
 521         ret = spi_write(trf->spi, buf, 2);
 522         if (ret)
 523                 dev_err(trf->dev, "%s - write: 0x%x 0x%x, ret: %d\n", __func__,
 524                         buf[0], buf[1], ret);
 525 
 526         return ret;
 527 }
 528 
 529 static int trf7970a_read_irqstatus(struct trf7970a *trf, u8 *status)
 530 {
 531         int ret;
 532         u8 buf[2];
 533         u8 addr;
 534 
 535         addr = TRF7970A_IRQ_STATUS | TRF7970A_CMD_BIT_RW;
 536 
 537         if (trf->quirks & TRF7970A_QUIRK_IRQ_STATUS_READ) {
 538                 addr |= TRF7970A_CMD_BIT_CONTINUOUS;
 539                 ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
 540         } else {
 541                 ret = spi_write_then_read(trf->spi, &addr, 1, buf, 1);
 542         }
 543 
 544         if (ret)
 545                 dev_err(trf->dev, "%s - irqstatus: Status read failed: %d\n",
 546                         __func__, ret);
 547         else
 548                 *status = buf[0];
 549 
 550         return ret;
 551 }
 552 
 553 static int trf7970a_read_target_proto(struct trf7970a *trf, u8 *target_proto)
 554 {
 555         int ret;
 556         u8 buf[2];
 557         u8 addr;
 558 
 559         addr = TRF79070A_NFC_TARGET_PROTOCOL | TRF7970A_CMD_BIT_RW |
 560                TRF7970A_CMD_BIT_CONTINUOUS;
 561 
 562         ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
 563         if (ret)
 564                 dev_err(trf->dev, "%s - target_proto: Read failed: %d\n",
 565                         __func__, ret);
 566         else
 567                 *target_proto = buf[0];
 568 
 569         return ret;
 570 }
 571 
 572 static int trf7970a_mode_detect(struct trf7970a *trf, u8 *rf_tech)
 573 {
 574         int ret;
 575         u8 target_proto, tech;
 576 
 577         ret = trf7970a_read_target_proto(trf, &target_proto);
 578         if (ret)
 579                 return ret;
 580 
 581         switch (target_proto) {
 582         case TRF79070A_NFC_TARGET_PROTOCOL_106A:
 583                 tech = NFC_DIGITAL_RF_TECH_106A;
 584                 break;
 585         case TRF79070A_NFC_TARGET_PROTOCOL_106B:
 586                 tech = NFC_DIGITAL_RF_TECH_106B;
 587                 break;
 588         case TRF79070A_NFC_TARGET_PROTOCOL_212F:
 589                 tech = NFC_DIGITAL_RF_TECH_212F;
 590                 break;
 591         case TRF79070A_NFC_TARGET_PROTOCOL_424F:
 592                 tech = NFC_DIGITAL_RF_TECH_424F;
 593                 break;
 594         default:
 595                 dev_dbg(trf->dev, "%s - mode_detect: target_proto: 0x%x\n",
 596                         __func__, target_proto);
 597                 return -EIO;
 598         }
 599 
 600         *rf_tech = tech;
 601 
 602         return ret;
 603 }
 604 
 605 static void trf7970a_send_upstream(struct trf7970a *trf)
 606 {
 607         dev_kfree_skb_any(trf->tx_skb);
 608         trf->tx_skb = NULL;
 609 
 610         if (trf->rx_skb && !IS_ERR(trf->rx_skb) && !trf->aborting)
 611                 print_hex_dump_debug("trf7970a rx data: ", DUMP_PREFIX_NONE,
 612                                      16, 1, trf->rx_skb->data, trf->rx_skb->len,
 613                                      false);
 614 
 615         trf->state = TRF7970A_ST_IDLE;
 616 
 617         if (trf->aborting) {
 618                 dev_dbg(trf->dev, "Abort process complete\n");
 619 
 620                 if (!IS_ERR(trf->rx_skb)) {
 621                         kfree_skb(trf->rx_skb);
 622                         trf->rx_skb = ERR_PTR(-ECANCELED);
 623                 }
 624 
 625                 trf->aborting = false;
 626         }
 627 
 628         trf->cb(trf->ddev, trf->cb_arg, trf->rx_skb);
 629 
 630         trf->rx_skb = NULL;
 631 }
 632 
 633 static void trf7970a_send_err_upstream(struct trf7970a *trf, int errno)
 634 {
 635         dev_dbg(trf->dev, "Error - state: %d, errno: %d\n", trf->state, errno);
 636 
 637         cancel_delayed_work(&trf->timeout_work);
 638 
 639         kfree_skb(trf->rx_skb);
 640         trf->rx_skb = ERR_PTR(errno);
 641 
 642         trf7970a_send_upstream(trf);
 643 }
 644 
 645 static int trf7970a_transmit(struct trf7970a *trf, struct sk_buff *skb,
 646                              unsigned int len, u8 *prefix,
 647                              unsigned int prefix_len)
 648 {
 649         struct spi_transfer t[2];
 650         struct spi_message m;
 651         unsigned int timeout;
 652         int ret;
 653 
 654         print_hex_dump_debug("trf7970a tx data: ", DUMP_PREFIX_NONE,
 655                              16, 1, skb->data, len, false);
 656 
 657         spi_message_init(&m);
 658 
 659         memset(&t, 0, sizeof(t));
 660 
 661         t[0].tx_buf = prefix;
 662         t[0].len = prefix_len;
 663         spi_message_add_tail(&t[0], &m);
 664 
 665         t[1].tx_buf = skb->data;
 666         t[1].len = len;
 667         spi_message_add_tail(&t[1], &m);
 668 
 669         ret = spi_sync(trf->spi, &m);
 670         if (ret) {
 671                 dev_err(trf->dev, "%s - Can't send tx data: %d\n", __func__,
 672                         ret);
 673                 return ret;
 674         }
 675 
 676         skb_pull(skb, len);
 677 
 678         if (skb->len > 0) {
 679                 trf->state = TRF7970A_ST_WAIT_FOR_TX_FIFO;
 680                 timeout = TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT;
 681         } else {
 682                 if (trf->issue_eof) {
 683                         trf->state = TRF7970A_ST_WAIT_TO_ISSUE_EOF;
 684                         timeout = TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF;
 685                 } else {
 686                         trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
 687 
 688                         if (!trf->timeout)
 689                                 timeout = TRF7970A_WAIT_FOR_TX_IRQ;
 690                         else
 691                                 timeout = trf->timeout;
 692                 }
 693         }
 694 
 695         dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n", timeout,
 696                 trf->state);
 697 
 698         schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
 699 
 700         return 0;
 701 }
 702 
 703 static void trf7970a_fill_fifo(struct trf7970a *trf)
 704 {
 705         struct sk_buff *skb = trf->tx_skb;
 706         unsigned int len;
 707         int ret;
 708         u8 fifo_bytes;
 709         u8 prefix;
 710 
 711         ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
 712         if (ret) {
 713                 trf7970a_send_err_upstream(trf, ret);
 714                 return;
 715         }
 716 
 717         dev_dbg(trf->dev, "Filling FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
 718 
 719         fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 720 
 721         /* Calculate how much more data can be written to the fifo */
 722         len = TRF7970A_FIFO_SIZE - fifo_bytes;
 723         if (!len) {
 724                 schedule_delayed_work(&trf->timeout_work,
 725                         msecs_to_jiffies(TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT));
 726                 return;
 727         }
 728 
 729         len = min(skb->len, len);
 730 
 731         prefix = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_FIFO_IO_REGISTER;
 732 
 733         ret = trf7970a_transmit(trf, skb, len, &prefix, sizeof(prefix));
 734         if (ret)
 735                 trf7970a_send_err_upstream(trf, ret);
 736 }
 737 
 738 static void trf7970a_drain_fifo(struct trf7970a *trf, u8 status)
 739 {
 740         struct sk_buff *skb = trf->rx_skb;
 741         int ret;
 742         u8 fifo_bytes;
 743 
 744         if (status & TRF7970A_IRQ_STATUS_ERROR) {
 745                 trf7970a_send_err_upstream(trf, -EIO);
 746                 return;
 747         }
 748 
 749         ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
 750         if (ret) {
 751                 trf7970a_send_err_upstream(trf, ret);
 752                 return;
 753         }
 754 
 755         dev_dbg(trf->dev, "Draining FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
 756 
 757         fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 758 
 759         if (!fifo_bytes)
 760                 goto no_rx_data;
 761 
 762         if (fifo_bytes > skb_tailroom(skb)) {
 763                 skb = skb_copy_expand(skb, skb_headroom(skb),
 764                                       max_t(int, fifo_bytes,
 765                                             TRF7970A_RX_SKB_ALLOC_SIZE),
 766                                       GFP_KERNEL);
 767                 if (!skb) {
 768                         trf7970a_send_err_upstream(trf, -ENOMEM);
 769                         return;
 770                 }
 771 
 772                 kfree_skb(trf->rx_skb);
 773                 trf->rx_skb = skb;
 774         }
 775 
 776         ret = trf7970a_read_cont(trf, TRF7970A_FIFO_IO_REGISTER,
 777                                  skb_put(skb, fifo_bytes), fifo_bytes);
 778         if (ret) {
 779                 trf7970a_send_err_upstream(trf, ret);
 780                 return;
 781         }
 782 
 783         /* If received Type 2 ACK/NACK, shift right 4 bits and pass up */
 784         if ((trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T) && (skb->len == 1) &&
 785             (trf->special_fcn_reg1 == TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX)) {
 786                 skb->data[0] >>= 4;
 787                 status = TRF7970A_IRQ_STATUS_SRX;
 788         } else {
 789                 trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA_CONT;
 790 
 791                 ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
 792                 if (ret) {
 793                         trf7970a_send_err_upstream(trf, ret);
 794                         return;
 795                 }
 796 
 797                 fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 798 
 799                 /* If there are bytes in the FIFO, set status to '0' so
 800                  * the if stmt below doesn't fire and the driver will wait
 801                  * for the trf7970a to generate another RX interrupt.
 802                  */
 803                 if (fifo_bytes)
 804                         status = 0;
 805         }
 806 
 807 no_rx_data:
 808         if (status == TRF7970A_IRQ_STATUS_SRX) {        /* Receive complete */
 809                 trf7970a_send_upstream(trf);
 810                 return;
 811         }
 812 
 813         dev_dbg(trf->dev, "Setting timeout for %d ms\n",
 814                 TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT);
 815 
 816         schedule_delayed_work(&trf->timeout_work,
 817                            msecs_to_jiffies(TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT));
 818 }
 819 
 820 static irqreturn_t trf7970a_irq(int irq, void *dev_id)
 821 {
 822         struct trf7970a *trf = dev_id;
 823         int ret;
 824         u8 status, fifo_bytes, iso_ctrl;
 825 
 826         mutex_lock(&trf->lock);
 827 
 828         if (trf->state == TRF7970A_ST_RF_OFF) {
 829                 mutex_unlock(&trf->lock);
 830                 return IRQ_NONE;
 831         }
 832 
 833         ret = trf7970a_read_irqstatus(trf, &status);
 834         if (ret) {
 835                 mutex_unlock(&trf->lock);
 836                 return IRQ_NONE;
 837         }
 838 
 839         dev_dbg(trf->dev, "IRQ - state: %d, status: 0x%x\n", trf->state,
 840                 status);
 841 
 842         if (!status) {
 843                 mutex_unlock(&trf->lock);
 844                 return IRQ_NONE;
 845         }
 846 
 847         switch (trf->state) {
 848         case TRF7970A_ST_IDLE:
 849         case TRF7970A_ST_IDLE_RX_BLOCKED:
 850                 /* If initiator and getting interrupts caused by RF noise,
 851                  * turn off the receiver to avoid unnecessary interrupts.
 852                  * It will be turned back on in trf7970a_send_cmd() when
 853                  * the next command is issued.
 854                  */
 855                 if (trf->is_initiator && (status & TRF7970A_IRQ_STATUS_ERROR)) {
 856                         trf7970a_cmd(trf, TRF7970A_CMD_BLOCK_RX);
 857                         trf->state = TRF7970A_ST_IDLE_RX_BLOCKED;
 858                 }
 859 
 860                 trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 861                 break;
 862         case TRF7970A_ST_WAIT_FOR_TX_FIFO:
 863                 if (status & TRF7970A_IRQ_STATUS_TX) {
 864                         trf->ignore_timeout =
 865                             !cancel_delayed_work(&trf->timeout_work);
 866                         trf7970a_fill_fifo(trf);
 867                 } else {
 868                         trf7970a_send_err_upstream(trf, -EIO);
 869                 }
 870                 break;
 871         case TRF7970A_ST_WAIT_FOR_RX_DATA:
 872         case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
 873                 if (status & TRF7970A_IRQ_STATUS_SRX) {
 874                         trf->ignore_timeout =
 875                             !cancel_delayed_work(&trf->timeout_work);
 876                         trf7970a_drain_fifo(trf, status);
 877                 } else if (status & TRF7970A_IRQ_STATUS_FIFO) {
 878                         ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS,
 879                                             &fifo_bytes);
 880 
 881                         fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 882 
 883                         if (ret)
 884                                 trf7970a_send_err_upstream(trf, ret);
 885                         else if (!fifo_bytes)
 886                                 trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 887                 } else if ((status == TRF7970A_IRQ_STATUS_TX) ||
 888                            (!trf->is_initiator &&
 889                             (status == (TRF7970A_IRQ_STATUS_TX |
 890                                         TRF7970A_IRQ_STATUS_NFC_RF)))) {
 891                         trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 892 
 893                         if (!trf->timeout) {
 894                                 trf->ignore_timeout =
 895                                     !cancel_delayed_work(&trf->timeout_work);
 896                                 trf->rx_skb = ERR_PTR(0);
 897                                 trf7970a_send_upstream(trf);
 898                                 break;
 899                         }
 900 
 901                         if (trf->is_initiator)
 902                                 break;
 903 
 904                         iso_ctrl = trf->iso_ctrl;
 905 
 906                         switch (trf->framing) {
 907                         case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
 908                                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
 909                                 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
 910                                 trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
 911                                 break;
 912                         case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
 913                                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
 914                                 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
 915                                 trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
 916                                 break;
 917                         case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
 918                                 ret = trf7970a_write(trf,
 919                                          TRF7970A_SPECIAL_FCN_REG1,
 920                                          TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL);
 921                                 if (ret)
 922                                         goto err_unlock_exit;
 923 
 924                                 trf->special_fcn_reg1 =
 925                                     TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL;
 926                                 break;
 927                         default:
 928                                 break;
 929                         }
 930 
 931                         if (iso_ctrl != trf->iso_ctrl) {
 932                                 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
 933                                                      iso_ctrl);
 934                                 if (ret)
 935                                         goto err_unlock_exit;
 936 
 937                                 trf->iso_ctrl = iso_ctrl;
 938                         }
 939                 } else {
 940                         trf7970a_send_err_upstream(trf, -EIO);
 941                 }
 942                 break;
 943         case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
 944                 if (status != TRF7970A_IRQ_STATUS_TX)
 945                         trf7970a_send_err_upstream(trf, -EIO);
 946                 break;
 947         case TRF7970A_ST_LISTENING:
 948                 if (status & TRF7970A_IRQ_STATUS_SRX) {
 949                         trf->ignore_timeout =
 950                             !cancel_delayed_work(&trf->timeout_work);
 951                         trf7970a_drain_fifo(trf, status);
 952                 } else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
 953                         trf7970a_send_err_upstream(trf, -EIO);
 954                 }
 955                 break;
 956         case TRF7970A_ST_LISTENING_MD:
 957                 if (status & TRF7970A_IRQ_STATUS_SRX) {
 958                         trf->ignore_timeout =
 959                             !cancel_delayed_work(&trf->timeout_work);
 960 
 961                         ret = trf7970a_mode_detect(trf, &trf->md_rf_tech);
 962                         if (ret) {
 963                                 trf7970a_send_err_upstream(trf, ret);
 964                         } else {
 965                                 trf->state = TRF7970A_ST_LISTENING;
 966                                 trf7970a_drain_fifo(trf, status);
 967                         }
 968                 } else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
 969                         trf7970a_send_err_upstream(trf, -EIO);
 970                 }
 971                 break;
 972         default:
 973                 dev_err(trf->dev, "%s - Driver in invalid state: %d\n",
 974                         __func__, trf->state);
 975         }
 976 
 977 err_unlock_exit:
 978         mutex_unlock(&trf->lock);
 979         return IRQ_HANDLED;
 980 }
 981 
 982 static void trf7970a_issue_eof(struct trf7970a *trf)
 983 {
 984         int ret;
 985 
 986         dev_dbg(trf->dev, "Issuing EOF\n");
 987 
 988         ret = trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 989         if (ret)
 990                 trf7970a_send_err_upstream(trf, ret);
 991 
 992         ret = trf7970a_cmd(trf, TRF7970A_CMD_EOF);
 993         if (ret)
 994                 trf7970a_send_err_upstream(trf, ret);
 995 
 996         trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
 997 
 998         dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n",
 999                 trf->timeout, trf->state);
1000 
1001         schedule_delayed_work(&trf->timeout_work,
1002                               msecs_to_jiffies(trf->timeout));
1003 }
1004 
1005 static void trf7970a_timeout_work_handler(struct work_struct *work)
1006 {
1007         struct trf7970a *trf = container_of(work, struct trf7970a,
1008                                             timeout_work.work);
1009 
1010         dev_dbg(trf->dev, "Timeout - state: %d, ignore_timeout: %d\n",
1011                 trf->state, trf->ignore_timeout);
1012 
1013         mutex_lock(&trf->lock);
1014 
1015         if (trf->ignore_timeout)
1016                 trf->ignore_timeout = false;
1017         else if (trf->state == TRF7970A_ST_WAIT_FOR_RX_DATA_CONT)
1018                 trf7970a_drain_fifo(trf, TRF7970A_IRQ_STATUS_SRX);
1019         else if (trf->state == TRF7970A_ST_WAIT_TO_ISSUE_EOF)
1020                 trf7970a_issue_eof(trf);
1021         else
1022                 trf7970a_send_err_upstream(trf, -ETIMEDOUT);
1023 
1024         mutex_unlock(&trf->lock);
1025 }
1026 
1027 static int trf7970a_init(struct trf7970a *trf)
1028 {
1029         int ret;
1030 
1031         dev_dbg(trf->dev, "Initializing device - state: %d\n", trf->state);
1032 
1033         ret = trf7970a_cmd(trf, TRF7970A_CMD_SOFT_INIT);
1034         if (ret)
1035                 goto err_out;
1036 
1037         ret = trf7970a_cmd(trf, TRF7970A_CMD_IDLE);
1038         if (ret)
1039                 goto err_out;
1040 
1041         ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1042                              trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1043         if (ret)
1044                 goto err_out;
1045 
1046         ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1047         if (ret)
1048                 goto err_out;
1049 
1050         usleep_range(1000, 2000);
1051 
1052         trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1053 
1054         ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1055                              trf->modulator_sys_clk_ctrl);
1056         if (ret)
1057                 goto err_out;
1058 
1059         ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS,
1060                              TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 |
1061                              TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32);
1062         if (ret)
1063                 goto err_out;
1064 
1065         ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1, 0);
1066         if (ret)
1067                 goto err_out;
1068 
1069         trf->special_fcn_reg1 = 0;
1070 
1071         trf->iso_ctrl = 0xff;
1072         return 0;
1073 
1074 err_out:
1075         dev_dbg(trf->dev, "Couldn't init device: %d\n", ret);
1076         return ret;
1077 }
1078 
1079 static void trf7970a_switch_rf_off(struct trf7970a *trf)
1080 {
1081         if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1082             (trf->state == TRF7970A_ST_RF_OFF))
1083                 return;
1084 
1085         dev_dbg(trf->dev, "Switching rf off\n");
1086 
1087         trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1088 
1089         trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, trf->chip_status_ctrl);
1090 
1091         trf->aborting = false;
1092         trf->state = TRF7970A_ST_RF_OFF;
1093 
1094         pm_runtime_mark_last_busy(trf->dev);
1095         pm_runtime_put_autosuspend(trf->dev);
1096 }
1097 
1098 static int trf7970a_switch_rf_on(struct trf7970a *trf)
1099 {
1100         int ret;
1101 
1102         dev_dbg(trf->dev, "Switching rf on\n");
1103 
1104         pm_runtime_get_sync(trf->dev);
1105 
1106         if (trf->state != TRF7970A_ST_RF_OFF) { /* Power on, RF off */
1107                 dev_err(trf->dev, "%s - Incorrect state: %d\n", __func__,
1108                         trf->state);
1109                 return -EINVAL;
1110         }
1111 
1112         ret = trf7970a_init(trf);
1113         if (ret) {
1114                 dev_err(trf->dev, "%s - Can't initialize: %d\n", __func__, ret);
1115                 return ret;
1116         }
1117 
1118         trf->state = TRF7970A_ST_IDLE;
1119 
1120         return 0;
1121 }
1122 
1123 static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on)
1124 {
1125         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1126         int ret = 0;
1127 
1128         dev_dbg(trf->dev, "Switching RF - state: %d, on: %d\n", trf->state, on);
1129 
1130         mutex_lock(&trf->lock);
1131 
1132         if (on) {
1133                 switch (trf->state) {
1134                 case TRF7970A_ST_PWR_OFF:
1135                 case TRF7970A_ST_RF_OFF:
1136                         ret = trf7970a_switch_rf_on(trf);
1137                         break;
1138                 case TRF7970A_ST_IDLE:
1139                 case TRF7970A_ST_IDLE_RX_BLOCKED:
1140                         break;
1141                 default:
1142                         dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1143                                 __func__, trf->state, on);
1144                         trf7970a_switch_rf_off(trf);
1145                         ret = -EINVAL;
1146                 }
1147         } else {
1148                 switch (trf->state) {
1149                 case TRF7970A_ST_PWR_OFF:
1150                 case TRF7970A_ST_RF_OFF:
1151                         break;
1152                 default:
1153                         dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1154                                 __func__, trf->state, on);
1155                         ret = -EINVAL;
1156                         /* FALLTHROUGH */
1157                 case TRF7970A_ST_IDLE:
1158                 case TRF7970A_ST_IDLE_RX_BLOCKED:
1159                 case TRF7970A_ST_WAIT_FOR_RX_DATA:
1160                 case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1161                         trf7970a_switch_rf_off(trf);
1162                 }
1163         }
1164 
1165         mutex_unlock(&trf->lock);
1166         return ret;
1167 }
1168 
1169 static int trf7970a_in_config_rf_tech(struct trf7970a *trf, int tech)
1170 {
1171         int ret = 0;
1172 
1173         dev_dbg(trf->dev, "rf technology: %d\n", tech);
1174 
1175         switch (tech) {
1176         case NFC_DIGITAL_RF_TECH_106A:
1177                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443A_106;
1178                 trf->modulator_sys_clk_ctrl =
1179                     (trf->modulator_sys_clk_ctrl & 0xf8) |
1180                     TRF7970A_MODULATOR_DEPTH_OOK;
1181                 trf->guard_time = TRF7970A_GUARD_TIME_NFCA;
1182                 break;
1183         case NFC_DIGITAL_RF_TECH_106B:
1184                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443B_106;
1185                 trf->modulator_sys_clk_ctrl =
1186                     (trf->modulator_sys_clk_ctrl & 0xf8) |
1187                     TRF7970A_MODULATOR_DEPTH_ASK10;
1188                 trf->guard_time = TRF7970A_GUARD_TIME_NFCB;
1189                 break;
1190         case NFC_DIGITAL_RF_TECH_212F:
1191                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_212;
1192                 trf->modulator_sys_clk_ctrl =
1193                     (trf->modulator_sys_clk_ctrl & 0xf8) |
1194                     TRF7970A_MODULATOR_DEPTH_ASK10;
1195                 trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1196                 break;
1197         case NFC_DIGITAL_RF_TECH_424F:
1198                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_424;
1199                 trf->modulator_sys_clk_ctrl =
1200                     (trf->modulator_sys_clk_ctrl & 0xf8) |
1201                     TRF7970A_MODULATOR_DEPTH_ASK10;
1202                 trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1203                 break;
1204         case NFC_DIGITAL_RF_TECH_ISO15693:
1205                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1206                 trf->modulator_sys_clk_ctrl =
1207                     (trf->modulator_sys_clk_ctrl & 0xf8) |
1208                     TRF7970A_MODULATOR_DEPTH_OOK;
1209                 trf->guard_time = TRF7970A_GUARD_TIME_15693;
1210                 break;
1211         default:
1212                 dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1213                 return -EINVAL;
1214         }
1215 
1216         trf->technology = tech;
1217 
1218         /* If in initiator mode and not changing the RF tech due to a
1219          * PSL sequence (indicated by 'trf->iso_ctrl == 0xff' from
1220          * trf7970a_init()), clear the NFC Target Detection Level register
1221          * due to erratum.
1222          */
1223         if (trf->iso_ctrl == 0xff)
1224                 ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1225 
1226         return ret;
1227 }
1228 
1229 static int trf7970a_is_rf_field(struct trf7970a *trf, bool *is_rf_field)
1230 {
1231         int ret;
1232         u8 rssi;
1233 
1234         ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1235                              trf->chip_status_ctrl |
1236                              TRF7970A_CHIP_STATUS_REC_ON);
1237         if (ret)
1238                 return ret;
1239 
1240         ret = trf7970a_cmd(trf, TRF7970A_CMD_TEST_EXT_RF);
1241         if (ret)
1242                 return ret;
1243 
1244         usleep_range(50, 60);
1245 
1246         ret = trf7970a_read(trf, TRF7970A_RSSI_OSC_STATUS, &rssi);
1247         if (ret)
1248                 return ret;
1249 
1250         ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1251                              trf->chip_status_ctrl);
1252         if (ret)
1253                 return ret;
1254 
1255         if (rssi & TRF7970A_RSSI_OSC_STATUS_RSSI_MASK)
1256                 *is_rf_field = true;
1257         else
1258                 *is_rf_field = false;
1259 
1260         return 0;
1261 }
1262 
1263 static int trf7970a_in_config_framing(struct trf7970a *trf, int framing)
1264 {
1265         u8 iso_ctrl = trf->iso_ctrl_tech;
1266         bool is_rf_field = false;
1267         int ret;
1268 
1269         dev_dbg(trf->dev, "framing: %d\n", framing);
1270 
1271         switch (framing) {
1272         case NFC_DIGITAL_FRAMING_NFCA_SHORT:
1273         case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1274                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1275                 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1276                 break;
1277         case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1278         case NFC_DIGITAL_FRAMING_NFCA_T4T:
1279         case NFC_DIGITAL_FRAMING_NFCB:
1280         case NFC_DIGITAL_FRAMING_NFCB_T4T:
1281         case NFC_DIGITAL_FRAMING_NFCF:
1282         case NFC_DIGITAL_FRAMING_NFCF_T3T:
1283         case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY:
1284         case NFC_DIGITAL_FRAMING_ISO15693_T5T:
1285         case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1286         case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1287                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1288                 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1289                 break;
1290         case NFC_DIGITAL_FRAMING_NFCA_T2T:
1291                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1292                 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1293                 break;
1294         default:
1295                 dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1296                 return -EINVAL;
1297         }
1298 
1299         trf->framing = framing;
1300 
1301         if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1302                 ret = trf7970a_is_rf_field(trf, &is_rf_field);
1303                 if (ret)
1304                         return ret;
1305 
1306                 if (is_rf_field)
1307                         return -EBUSY;
1308         }
1309 
1310         if (iso_ctrl != trf->iso_ctrl) {
1311                 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1312                 if (ret)
1313                         return ret;
1314 
1315                 trf->iso_ctrl = iso_ctrl;
1316 
1317                 ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1318                                      trf->modulator_sys_clk_ctrl);
1319                 if (ret)
1320                         return ret;
1321         }
1322 
1323         if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1324                 ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1325                                      trf->chip_status_ctrl |
1326                                      TRF7970A_CHIP_STATUS_RF_ON);
1327                 if (ret)
1328                         return ret;
1329 
1330                 trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1331 
1332                 usleep_range(trf->guard_time, trf->guard_time + 1000);
1333         }
1334 
1335         return 0;
1336 }
1337 
1338 static int trf7970a_in_configure_hw(struct nfc_digital_dev *ddev, int type,
1339                                     int param)
1340 {
1341         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1342         int ret;
1343 
1344         dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1345 
1346         mutex_lock(&trf->lock);
1347 
1348         trf->is_initiator = true;
1349 
1350         if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1351             (trf->state == TRF7970A_ST_RF_OFF)) {
1352                 ret = trf7970a_switch_rf_on(trf);
1353                 if (ret)
1354                         goto err_unlock;
1355         }
1356 
1357         switch (type) {
1358         case NFC_DIGITAL_CONFIG_RF_TECH:
1359                 ret = trf7970a_in_config_rf_tech(trf, param);
1360                 break;
1361         case NFC_DIGITAL_CONFIG_FRAMING:
1362                 ret = trf7970a_in_config_framing(trf, param);
1363                 break;
1364         default:
1365                 dev_dbg(trf->dev, "Unknown type: %d\n", type);
1366                 ret = -EINVAL;
1367         }
1368 
1369 err_unlock:
1370         mutex_unlock(&trf->lock);
1371         return ret;
1372 }
1373 
1374 static int trf7970a_is_iso15693_write_or_lock(u8 cmd)
1375 {
1376         switch (cmd) {
1377         case ISO15693_CMD_WRITE_SINGLE_BLOCK:
1378         case ISO15693_CMD_LOCK_BLOCK:
1379         case ISO15693_CMD_WRITE_MULTIPLE_BLOCK:
1380         case ISO15693_CMD_WRITE_AFI:
1381         case ISO15693_CMD_LOCK_AFI:
1382         case ISO15693_CMD_WRITE_DSFID:
1383         case ISO15693_CMD_LOCK_DSFID:
1384                 return 1;
1385                 break;
1386         default:
1387                 return 0;
1388         }
1389 }
1390 
1391 static int trf7970a_per_cmd_config(struct trf7970a *trf, struct sk_buff *skb)
1392 {
1393         u8 *req = skb->data;
1394         u8 special_fcn_reg1, iso_ctrl;
1395         int ret;
1396 
1397         trf->issue_eof = false;
1398 
1399         /* When issuing Type 2 read command, make sure the '4_bit_RX' bit in
1400          * special functions register 1 is cleared; otherwise, its a write or
1401          * sector select command and '4_bit_RX' must be set.
1402          *
1403          * When issuing an ISO 15693 command, inspect the flags byte to see
1404          * what speed to use.  Also, remember if the OPTION flag is set on
1405          * a Type 5 write or lock command so the driver will know that it
1406          * has to send an EOF in order to get a response.
1407          */
1408         if ((trf->technology == NFC_DIGITAL_RF_TECH_106A) &&
1409             (trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T)) {
1410                 if (req[0] == NFC_T2T_CMD_READ)
1411                         special_fcn_reg1 = 0;
1412                 else
1413                         special_fcn_reg1 = TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX;
1414 
1415                 if (special_fcn_reg1 != trf->special_fcn_reg1) {
1416                         ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1,
1417                                              special_fcn_reg1);
1418                         if (ret)
1419                                 return ret;
1420 
1421                         trf->special_fcn_reg1 = special_fcn_reg1;
1422                 }
1423         } else if (trf->technology == NFC_DIGITAL_RF_TECH_ISO15693) {
1424                 iso_ctrl = trf->iso_ctrl & ~TRF7970A_ISO_CTRL_RFID_SPEED_MASK;
1425 
1426                 switch (req[0] & ISO15693_REQ_FLAG_SPEED_MASK) {
1427                 case 0x00:
1428                         iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_662;
1429                         break;
1430                 case ISO15693_REQ_FLAG_SUB_CARRIER:
1431                         iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a;
1432                         break;
1433                 case ISO15693_REQ_FLAG_DATA_RATE:
1434                         iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1435                         break;
1436                 case (ISO15693_REQ_FLAG_SUB_CARRIER |
1437                       ISO15693_REQ_FLAG_DATA_RATE):
1438                         iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669;
1439                         break;
1440                 }
1441 
1442                 if (iso_ctrl != trf->iso_ctrl) {
1443                         ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1444                         if (ret)
1445                                 return ret;
1446 
1447                         trf->iso_ctrl = iso_ctrl;
1448                 }
1449 
1450                 if ((trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) &&
1451                     trf7970a_is_iso15693_write_or_lock(req[1]) &&
1452                     (req[0] & ISO15693_REQ_FLAG_OPTION))
1453                         trf->issue_eof = true;
1454         }
1455 
1456         return 0;
1457 }
1458 
1459 static int trf7970a_send_cmd(struct nfc_digital_dev *ddev,
1460                              struct sk_buff *skb, u16 timeout,
1461                              nfc_digital_cmd_complete_t cb, void *arg)
1462 {
1463         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1464         u8 prefix[5];
1465         unsigned int len;
1466         int ret;
1467         u8 status;
1468 
1469         dev_dbg(trf->dev, "New request - state: %d, timeout: %d ms, len: %d\n",
1470                 trf->state, timeout, skb->len);
1471 
1472         if (skb->len > TRF7970A_TX_MAX)
1473                 return -EINVAL;
1474 
1475         mutex_lock(&trf->lock);
1476 
1477         if ((trf->state != TRF7970A_ST_IDLE) &&
1478             (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1479                 dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1480                         trf->state);
1481                 ret = -EIO;
1482                 goto out_err;
1483         }
1484 
1485         if (trf->aborting) {
1486                 dev_dbg(trf->dev, "Abort process complete\n");
1487                 trf->aborting = false;
1488                 ret = -ECANCELED;
1489                 goto out_err;
1490         }
1491 
1492         if (timeout) {
1493                 trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1494                                                  GFP_KERNEL);
1495                 if (!trf->rx_skb) {
1496                         dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1497                         ret = -ENOMEM;
1498                         goto out_err;
1499                 }
1500         }
1501 
1502         if (trf->state == TRF7970A_ST_IDLE_RX_BLOCKED) {
1503                 ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1504                 if (ret)
1505                         goto out_err;
1506 
1507                 trf->state = TRF7970A_ST_IDLE;
1508         }
1509 
1510         if (trf->is_initiator) {
1511                 ret = trf7970a_per_cmd_config(trf, skb);
1512                 if (ret)
1513                         goto out_err;
1514         }
1515 
1516         trf->ddev = ddev;
1517         trf->tx_skb = skb;
1518         trf->cb = cb;
1519         trf->cb_arg = arg;
1520         trf->timeout = timeout;
1521         trf->ignore_timeout = false;
1522 
1523         len = skb->len;
1524 
1525         /* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
1526          * on what the current framing is, the address of the TX length byte 1
1527          * register (0x1d), and the 2 byte length of the data to be transmitted.
1528          * That totals 5 bytes.
1529          */
1530         prefix[0] = TRF7970A_CMD_BIT_CTRL |
1531             TRF7970A_CMD_BIT_OPCODE(TRF7970A_CMD_FIFO_RESET);
1532         prefix[1] = TRF7970A_CMD_BIT_CTRL |
1533             TRF7970A_CMD_BIT_OPCODE(trf->tx_cmd);
1534         prefix[2] = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_TX_LENGTH_BYTE1;
1535 
1536         if (trf->framing == NFC_DIGITAL_FRAMING_NFCA_SHORT) {
1537                 prefix[3] = 0x00;
1538                 prefix[4] = 0x0f;       /* 7 bits */
1539         } else {
1540                 prefix[3] = (len & 0xf00) >> 4;
1541                 prefix[3] |= ((len & 0xf0) >> 4);
1542                 prefix[4] = ((len & 0x0f) << 4);
1543         }
1544 
1545         len = min_t(int, skb->len, TRF7970A_FIFO_SIZE);
1546 
1547         /* Clear possible spurious interrupt */
1548         ret = trf7970a_read_irqstatus(trf, &status);
1549         if (ret)
1550                 goto out_err;
1551 
1552         ret = trf7970a_transmit(trf, skb, len, prefix, sizeof(prefix));
1553         if (ret) {
1554                 kfree_skb(trf->rx_skb);
1555                 trf->rx_skb = NULL;
1556         }
1557 
1558 out_err:
1559         mutex_unlock(&trf->lock);
1560         return ret;
1561 }
1562 
1563 static int trf7970a_tg_config_rf_tech(struct trf7970a *trf, int tech)
1564 {
1565         int ret = 0;
1566 
1567         dev_dbg(trf->dev, "rf technology: %d\n", tech);
1568 
1569         switch (tech) {
1570         case NFC_DIGITAL_RF_TECH_106A:
1571                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1572                     TRF7970A_ISO_CTRL_NFC_CE | TRF7970A_ISO_CTRL_NFC_CE_14443A;
1573                 trf->modulator_sys_clk_ctrl =
1574                     (trf->modulator_sys_clk_ctrl & 0xf8) |
1575                     TRF7970A_MODULATOR_DEPTH_OOK;
1576                 break;
1577         case NFC_DIGITAL_RF_TECH_212F:
1578                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1579                     TRF7970A_ISO_CTRL_NFC_NFCF_212;
1580                 trf->modulator_sys_clk_ctrl =
1581                     (trf->modulator_sys_clk_ctrl & 0xf8) |
1582                     TRF7970A_MODULATOR_DEPTH_ASK10;
1583                 break;
1584         case NFC_DIGITAL_RF_TECH_424F:
1585                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1586                     TRF7970A_ISO_CTRL_NFC_NFCF_424;
1587                 trf->modulator_sys_clk_ctrl =
1588                     (trf->modulator_sys_clk_ctrl & 0xf8) |
1589                     TRF7970A_MODULATOR_DEPTH_ASK10;
1590                 break;
1591         default:
1592                 dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1593                 return -EINVAL;
1594         }
1595 
1596         trf->technology = tech;
1597 
1598         /* Normally we write the ISO_CTRL register in
1599          * trf7970a_tg_config_framing() because the framing can change
1600          * the value written.  However, when sending a PSL RES,
1601          * digital_tg_send_psl_res_complete() doesn't call
1602          * trf7970a_tg_config_framing() so we must write the register
1603          * here.
1604          */
1605         if ((trf->framing == NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED) &&
1606             (trf->iso_ctrl_tech != trf->iso_ctrl)) {
1607                 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
1608                                      trf->iso_ctrl_tech);
1609 
1610                 trf->iso_ctrl = trf->iso_ctrl_tech;
1611         }
1612 
1613         return ret;
1614 }
1615 
1616 /* Since this is a target routine, several of the framing calls are
1617  * made between receiving the request and sending the response so they
1618  * should take effect until after the response is sent.  This is accomplished
1619  * by skipping the ISO_CTRL register write here and doing it in the interrupt
1620  * handler.
1621  */
1622 static int trf7970a_tg_config_framing(struct trf7970a *trf, int framing)
1623 {
1624         u8 iso_ctrl = trf->iso_ctrl_tech;
1625         int ret;
1626 
1627         dev_dbg(trf->dev, "framing: %d\n", framing);
1628 
1629         switch (framing) {
1630         case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1631                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1632                 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1633                 break;
1634         case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1635         case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1636         case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
1637                 /* These ones are applied in the interrupt handler */
1638                 iso_ctrl = trf->iso_ctrl; /* Don't write to ISO_CTRL yet */
1639                 break;
1640         case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1641                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1642                 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1643                 break;
1644         case NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED:
1645                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1646                 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1647                 break;
1648         default:
1649                 dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1650                 return -EINVAL;
1651         }
1652 
1653         trf->framing = framing;
1654 
1655         if (iso_ctrl != trf->iso_ctrl) {
1656                 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1657                 if (ret)
1658                         return ret;
1659 
1660                 trf->iso_ctrl = iso_ctrl;
1661 
1662                 ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1663                                      trf->modulator_sys_clk_ctrl);
1664                 if (ret)
1665                         return ret;
1666         }
1667 
1668         if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1669                 ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1670                                      trf->chip_status_ctrl |
1671                                      TRF7970A_CHIP_STATUS_RF_ON);
1672                 if (ret)
1673                         return ret;
1674 
1675                 trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1676         }
1677 
1678         return 0;
1679 }
1680 
1681 static int trf7970a_tg_configure_hw(struct nfc_digital_dev *ddev, int type,
1682                                     int param)
1683 {
1684         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1685         int ret;
1686 
1687         dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1688 
1689         mutex_lock(&trf->lock);
1690 
1691         trf->is_initiator = false;
1692 
1693         if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1694             (trf->state == TRF7970A_ST_RF_OFF)) {
1695                 ret = trf7970a_switch_rf_on(trf);
1696                 if (ret)
1697                         goto err_unlock;
1698         }
1699 
1700         switch (type) {
1701         case NFC_DIGITAL_CONFIG_RF_TECH:
1702                 ret = trf7970a_tg_config_rf_tech(trf, param);
1703                 break;
1704         case NFC_DIGITAL_CONFIG_FRAMING:
1705                 ret = trf7970a_tg_config_framing(trf, param);
1706                 break;
1707         default:
1708                 dev_dbg(trf->dev, "Unknown type: %d\n", type);
1709                 ret = -EINVAL;
1710         }
1711 
1712 err_unlock:
1713         mutex_unlock(&trf->lock);
1714         return ret;
1715 }
1716 
1717 static int _trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1718                                nfc_digital_cmd_complete_t cb, void *arg,
1719                                bool mode_detect)
1720 {
1721         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1722         int ret;
1723 
1724         mutex_lock(&trf->lock);
1725 
1726         if ((trf->state != TRF7970A_ST_IDLE) &&
1727             (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1728                 dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1729                         trf->state);
1730                 ret = -EIO;
1731                 goto out_err;
1732         }
1733 
1734         if (trf->aborting) {
1735                 dev_dbg(trf->dev, "Abort process complete\n");
1736                 trf->aborting = false;
1737                 ret = -ECANCELED;
1738                 goto out_err;
1739         }
1740 
1741         trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1742                                          GFP_KERNEL);
1743         if (!trf->rx_skb) {
1744                 dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1745                 ret = -ENOMEM;
1746                 goto out_err;
1747         }
1748 
1749         ret = trf7970a_write(trf, TRF7970A_RX_SPECIAL_SETTINGS,
1750                              TRF7970A_RX_SPECIAL_SETTINGS_HBT |
1751                              TRF7970A_RX_SPECIAL_SETTINGS_M848 |
1752                              TRF7970A_RX_SPECIAL_SETTINGS_C424 |
1753                              TRF7970A_RX_SPECIAL_SETTINGS_C212);
1754         if (ret)
1755                 goto out_err;
1756 
1757         ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1758                              trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1759         if (ret)
1760                 goto out_err;
1761 
1762         ret = trf7970a_write(trf, TRF7970A_NFC_LOW_FIELD_LEVEL,
1763                              TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(0x3));
1764         if (ret)
1765                 goto out_err;
1766 
1767         ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL,
1768                              TRF7970A_NFC_TARGET_LEVEL_RFDET(0x7));
1769         if (ret)
1770                 goto out_err;
1771 
1772         trf->ddev = ddev;
1773         trf->cb = cb;
1774         trf->cb_arg = arg;
1775         trf->timeout = timeout;
1776         trf->ignore_timeout = false;
1777 
1778         ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1779         if (ret)
1780                 goto out_err;
1781 
1782         trf->state = mode_detect ? TRF7970A_ST_LISTENING_MD :
1783                                    TRF7970A_ST_LISTENING;
1784 
1785         schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
1786 
1787 out_err:
1788         mutex_unlock(&trf->lock);
1789         return ret;
1790 }
1791 
1792 static int trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1793                               nfc_digital_cmd_complete_t cb, void *arg)
1794 {
1795         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1796 
1797         dev_dbg(trf->dev, "Listen - state: %d, timeout: %d ms\n",
1798                 trf->state, timeout);
1799 
1800         return _trf7970a_tg_listen(ddev, timeout, cb, arg, false);
1801 }
1802 
1803 static int trf7970a_tg_listen_md(struct nfc_digital_dev *ddev,
1804                                  u16 timeout, nfc_digital_cmd_complete_t cb,
1805                                  void *arg)
1806 {
1807         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1808         int ret;
1809 
1810         dev_dbg(trf->dev, "Listen MD - state: %d, timeout: %d ms\n",
1811                 trf->state, timeout);
1812 
1813         ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
1814                                        NFC_DIGITAL_RF_TECH_106A);
1815         if (ret)
1816                 return ret;
1817 
1818         ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1819                                        NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
1820         if (ret)
1821                 return ret;
1822 
1823         return _trf7970a_tg_listen(ddev, timeout, cb, arg, true);
1824 }
1825 
1826 static int trf7970a_tg_get_rf_tech(struct nfc_digital_dev *ddev, u8 *rf_tech)
1827 {
1828         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1829 
1830         dev_dbg(trf->dev, "Get RF Tech - state: %d, rf_tech: %d\n",
1831                 trf->state, trf->md_rf_tech);
1832 
1833         *rf_tech = trf->md_rf_tech;
1834 
1835         return 0;
1836 }
1837 
1838 static void trf7970a_abort_cmd(struct nfc_digital_dev *ddev)
1839 {
1840         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1841 
1842         dev_dbg(trf->dev, "Abort process initiated\n");
1843 
1844         mutex_lock(&trf->lock);
1845 
1846         switch (trf->state) {
1847         case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1848         case TRF7970A_ST_WAIT_FOR_RX_DATA:
1849         case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1850         case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1851                 trf->aborting = true;
1852                 break;
1853         case TRF7970A_ST_LISTENING:
1854                 trf->ignore_timeout = !cancel_delayed_work(&trf->timeout_work);
1855                 trf7970a_send_err_upstream(trf, -ECANCELED);
1856                 dev_dbg(trf->dev, "Abort process complete\n");
1857                 break;
1858         default:
1859                 break;
1860         }
1861 
1862         mutex_unlock(&trf->lock);
1863 }
1864 
1865 static struct nfc_digital_ops trf7970a_nfc_ops = {
1866         .in_configure_hw        = trf7970a_in_configure_hw,
1867         .in_send_cmd            = trf7970a_send_cmd,
1868         .tg_configure_hw        = trf7970a_tg_configure_hw,
1869         .tg_send_cmd            = trf7970a_send_cmd,
1870         .tg_listen              = trf7970a_tg_listen,
1871         .tg_listen_md           = trf7970a_tg_listen_md,
1872         .tg_get_rf_tech         = trf7970a_tg_get_rf_tech,
1873         .switch_rf              = trf7970a_switch_rf,
1874         .abort_cmd              = trf7970a_abort_cmd,
1875 };
1876 
1877 static int trf7970a_power_up(struct trf7970a *trf)
1878 {
1879         int ret;
1880 
1881         dev_dbg(trf->dev, "Powering up - state: %d\n", trf->state);
1882 
1883         if (trf->state != TRF7970A_ST_PWR_OFF)
1884                 return 0;
1885 
1886         ret = regulator_enable(trf->regulator);
1887         if (ret) {
1888                 dev_err(trf->dev, "%s - Can't enable VIN: %d\n", __func__, ret);
1889                 return ret;
1890         }
1891 
1892         usleep_range(5000, 6000);
1893 
1894         if (trf->en2_gpiod &&
1895             !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW)) {
1896                 gpiod_set_value_cansleep(trf->en2_gpiod, 1);
1897                 usleep_range(1000, 2000);
1898         }
1899 
1900         gpiod_set_value_cansleep(trf->en_gpiod, 1);
1901 
1902         usleep_range(20000, 21000);
1903 
1904         trf->state = TRF7970A_ST_RF_OFF;
1905 
1906         return 0;
1907 }
1908 
1909 static int trf7970a_power_down(struct trf7970a *trf)
1910 {
1911         int ret;
1912 
1913         dev_dbg(trf->dev, "Powering down - state: %d\n", trf->state);
1914 
1915         if (trf->state == TRF7970A_ST_PWR_OFF)
1916                 return 0;
1917 
1918         if (trf->state != TRF7970A_ST_RF_OFF) {
1919                 dev_dbg(trf->dev, "Can't power down - not RF_OFF state (%d)\n",
1920                         trf->state);
1921                 return -EBUSY;
1922         }
1923 
1924         gpiod_set_value_cansleep(trf->en_gpiod, 0);
1925 
1926         if (trf->en2_gpiod && !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW))
1927                 gpiod_set_value_cansleep(trf->en2_gpiod, 0);
1928 
1929         ret = regulator_disable(trf->regulator);
1930         if (ret)
1931                 dev_err(trf->dev, "%s - Can't disable VIN: %d\n", __func__,
1932                         ret);
1933 
1934         trf->state = TRF7970A_ST_PWR_OFF;
1935 
1936         return ret;
1937 }
1938 
1939 static int trf7970a_startup(struct trf7970a *trf)
1940 {
1941         int ret;
1942 
1943         ret = trf7970a_power_up(trf);
1944         if (ret)
1945                 return ret;
1946 
1947         pm_runtime_set_active(trf->dev);
1948         pm_runtime_enable(trf->dev);
1949         pm_runtime_mark_last_busy(trf->dev);
1950 
1951         return 0;
1952 }
1953 
1954 static void trf7970a_shutdown(struct trf7970a *trf)
1955 {
1956         switch (trf->state) {
1957         case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1958         case TRF7970A_ST_WAIT_FOR_RX_DATA:
1959         case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1960         case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1961         case TRF7970A_ST_LISTENING:
1962                 trf7970a_send_err_upstream(trf, -ECANCELED);
1963                 /* FALLTHROUGH */
1964         case TRF7970A_ST_IDLE:
1965         case TRF7970A_ST_IDLE_RX_BLOCKED:
1966                 trf7970a_switch_rf_off(trf);
1967                 break;
1968         default:
1969                 break;
1970         }
1971 
1972         pm_runtime_disable(trf->dev);
1973         pm_runtime_set_suspended(trf->dev);
1974 
1975         trf7970a_power_down(trf);
1976 }
1977 
1978 static int trf7970a_get_autosuspend_delay(struct device_node *np)
1979 {
1980         int autosuspend_delay, ret;
1981 
1982         ret = of_property_read_u32(np, "autosuspend-delay", &autosuspend_delay);
1983         if (ret)
1984                 autosuspend_delay = TRF7970A_AUTOSUSPEND_DELAY;
1985 
1986         return autosuspend_delay;
1987 }
1988 
1989 static int trf7970a_probe(struct spi_device *spi)
1990 {
1991         struct device_node *np = spi->dev.of_node;
1992         struct trf7970a *trf;
1993         int uvolts, autosuspend_delay, ret;
1994         u32 clk_freq = TRF7970A_13MHZ_CLOCK_FREQUENCY;
1995 
1996         if (!np) {
1997                 dev_err(&spi->dev, "No Device Tree entry\n");
1998                 return -EINVAL;
1999         }
2000 
2001         trf = devm_kzalloc(&spi->dev, sizeof(*trf), GFP_KERNEL);
2002         if (!trf)
2003                 return -ENOMEM;
2004 
2005         trf->state = TRF7970A_ST_PWR_OFF;
2006         trf->dev = &spi->dev;
2007         trf->spi = spi;
2008 
2009         spi->mode = SPI_MODE_1;
2010         spi->bits_per_word = 8;
2011 
2012         ret = spi_setup(spi);
2013         if (ret < 0) {
2014                 dev_err(trf->dev, "Can't set up SPI Communication\n");
2015                 return ret;
2016         }
2017 
2018         if (of_property_read_bool(np, "irq-status-read-quirk"))
2019                 trf->quirks |= TRF7970A_QUIRK_IRQ_STATUS_READ;
2020 
2021         /* There are two enable pins - only EN must be present in the DT */
2022         trf->en_gpiod = devm_gpiod_get_index(trf->dev, "ti,enable", 0,
2023                                              GPIOD_OUT_LOW);
2024         if (IS_ERR(trf->en_gpiod)) {
2025                 dev_err(trf->dev, "No EN GPIO property\n");
2026                 return PTR_ERR(trf->en_gpiod);
2027         }
2028 
2029         trf->en2_gpiod = devm_gpiod_get_index_optional(trf->dev, "ti,enable", 1,
2030                                                        GPIOD_OUT_LOW);
2031         if (!trf->en2_gpiod) {
2032                 dev_info(trf->dev, "No EN2 GPIO property\n");
2033         } else if (IS_ERR(trf->en2_gpiod)) {
2034                 dev_err(trf->dev, "Error getting EN2 GPIO property: %ld\n",
2035                         PTR_ERR(trf->en2_gpiod));
2036                 return PTR_ERR(trf->en2_gpiod);
2037         } else if (of_property_read_bool(np, "en2-rf-quirk")) {
2038                 trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;
2039         }
2040 
2041         of_property_read_u32(np, "clock-frequency", &clk_freq);
2042         if ((clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY) &&
2043             (clk_freq != TRF7970A_13MHZ_CLOCK_FREQUENCY)) {
2044                 dev_err(trf->dev,
2045                         "clock-frequency (%u Hz) unsupported\n", clk_freq);
2046                 return -EINVAL;
2047         }
2048 
2049         if (clk_freq == TRF7970A_27MHZ_CLOCK_FREQUENCY) {
2050                 trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_27MHZ;
2051                 dev_dbg(trf->dev, "trf7970a configured for 27MHz crystal\n");
2052         } else {
2053                 trf->modulator_sys_clk_ctrl = 0;
2054         }
2055 
2056         ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL,
2057                                         trf7970a_irq,
2058                                         IRQF_TRIGGER_RISING | IRQF_ONESHOT,
2059                                         "trf7970a", trf);
2060         if (ret) {
2061                 dev_err(trf->dev, "Can't request IRQ#%d: %d\n", spi->irq, ret);
2062                 return ret;
2063         }
2064 
2065         mutex_init(&trf->lock);
2066         INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
2067 
2068         trf->regulator = devm_regulator_get(&spi->dev, "vin");
2069         if (IS_ERR(trf->regulator)) {
2070                 ret = PTR_ERR(trf->regulator);
2071                 dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret);
2072                 goto err_destroy_lock;
2073         }
2074 
2075         ret = regulator_enable(trf->regulator);
2076         if (ret) {
2077                 dev_err(trf->dev, "Can't enable VIN: %d\n", ret);
2078                 goto err_destroy_lock;
2079         }
2080 
2081         uvolts = regulator_get_voltage(trf->regulator);
2082         if (uvolts > 4000000)
2083                 trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;
2084 
2085         trf->regulator = devm_regulator_get(&spi->dev, "vdd-io");
2086         if (IS_ERR(trf->regulator)) {
2087                 ret = PTR_ERR(trf->regulator);
2088                 dev_err(trf->dev, "Can't get VDD_IO regulator: %d\n", ret);
2089                 goto err_destroy_lock;
2090         }
2091 
2092         ret = regulator_enable(trf->regulator);
2093         if (ret) {
2094                 dev_err(trf->dev, "Can't enable VDD_IO: %d\n", ret);
2095                 goto err_destroy_lock;
2096         }
2097 
2098         if (regulator_get_voltage(trf->regulator) == 1800000) {
2099                 trf->io_ctrl = TRF7970A_REG_IO_CTRL_IO_LOW;
2100                 dev_dbg(trf->dev, "trf7970a config vdd_io to 1.8V\n");
2101         }
2102 
2103         trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,
2104                                                 TRF7970A_SUPPORTED_PROTOCOLS,
2105                                                 NFC_DIGITAL_DRV_CAPS_IN_CRC |
2106                                                 NFC_DIGITAL_DRV_CAPS_TG_CRC, 0,
2107                                                 0);
2108         if (!trf->ddev) {
2109                 dev_err(trf->dev, "Can't allocate NFC digital device\n");
2110                 ret = -ENOMEM;
2111                 goto err_disable_regulator;
2112         }
2113 
2114         nfc_digital_set_parent_dev(trf->ddev, trf->dev);
2115         nfc_digital_set_drvdata(trf->ddev, trf);
2116         spi_set_drvdata(spi, trf);
2117 
2118         autosuspend_delay = trf7970a_get_autosuspend_delay(np);
2119 
2120         pm_runtime_set_autosuspend_delay(trf->dev, autosuspend_delay);
2121         pm_runtime_use_autosuspend(trf->dev);
2122 
2123         ret = trf7970a_startup(trf);
2124         if (ret)
2125                 goto err_free_ddev;
2126 
2127         ret = nfc_digital_register_device(trf->ddev);
2128         if (ret) {
2129                 dev_err(trf->dev, "Can't register NFC digital device: %d\n",
2130                         ret);
2131                 goto err_shutdown;
2132         }
2133 
2134         return 0;
2135 
2136 err_shutdown:
2137         trf7970a_shutdown(trf);
2138 err_free_ddev:
2139         nfc_digital_free_device(trf->ddev);
2140 err_disable_regulator:
2141         regulator_disable(trf->regulator);
2142 err_destroy_lock:
2143         mutex_destroy(&trf->lock);
2144         return ret;
2145 }
2146 
2147 static int trf7970a_remove(struct spi_device *spi)
2148 {
2149         struct trf7970a *trf = spi_get_drvdata(spi);
2150 
2151         mutex_lock(&trf->lock);
2152 
2153         trf7970a_shutdown(trf);
2154 
2155         mutex_unlock(&trf->lock);
2156 
2157         nfc_digital_unregister_device(trf->ddev);
2158         nfc_digital_free_device(trf->ddev);
2159 
2160         regulator_disable(trf->regulator);
2161 
2162         mutex_destroy(&trf->lock);
2163 
2164         return 0;
2165 }
2166 
2167 #ifdef CONFIG_PM_SLEEP
2168 static int trf7970a_suspend(struct device *dev)
2169 {
2170         struct spi_device *spi = to_spi_device(dev);
2171         struct trf7970a *trf = spi_get_drvdata(spi);
2172 
2173         dev_dbg(dev, "Suspend\n");
2174 
2175         mutex_lock(&trf->lock);
2176 
2177         trf7970a_shutdown(trf);
2178 
2179         mutex_unlock(&trf->lock);
2180 
2181         return 0;
2182 }
2183 
2184 static int trf7970a_resume(struct device *dev)
2185 {
2186         struct spi_device *spi = to_spi_device(dev);
2187         struct trf7970a *trf = spi_get_drvdata(spi);
2188         int ret;
2189 
2190         dev_dbg(dev, "Resume\n");
2191 
2192         mutex_lock(&trf->lock);
2193 
2194         ret = trf7970a_startup(trf);
2195 
2196         mutex_unlock(&trf->lock);
2197 
2198         return ret;
2199 }
2200 #endif
2201 
2202 #ifdef CONFIG_PM
2203 static int trf7970a_pm_runtime_suspend(struct device *dev)
2204 {
2205         struct spi_device *spi = to_spi_device(dev);
2206         struct trf7970a *trf = spi_get_drvdata(spi);
2207         int ret;
2208 
2209         dev_dbg(dev, "Runtime suspend\n");
2210 
2211         mutex_lock(&trf->lock);
2212 
2213         ret = trf7970a_power_down(trf);
2214 
2215         mutex_unlock(&trf->lock);
2216 
2217         return ret;
2218 }
2219 
2220 static int trf7970a_pm_runtime_resume(struct device *dev)
2221 {
2222         struct spi_device *spi = to_spi_device(dev);
2223         struct trf7970a *trf = spi_get_drvdata(spi);
2224         int ret;
2225 
2226         dev_dbg(dev, "Runtime resume\n");
2227 
2228         ret = trf7970a_power_up(trf);
2229         if (!ret)
2230                 pm_runtime_mark_last_busy(dev);
2231 
2232         return ret;
2233 }
2234 #endif
2235 
2236 static const struct dev_pm_ops trf7970a_pm_ops = {
2237         SET_SYSTEM_SLEEP_PM_OPS(trf7970a_suspend, trf7970a_resume)
2238         SET_RUNTIME_PM_OPS(trf7970a_pm_runtime_suspend,
2239                            trf7970a_pm_runtime_resume, NULL)
2240 };
2241 
2242 static const struct of_device_id trf7970a_of_match[] = {
2243         {.compatible = "ti,trf7970a",},
2244         {},
2245 };
2246 
2247 MODULE_DEVICE_TABLE(of, trf7970a_of_match);
2248 
2249 static const struct spi_device_id trf7970a_id_table[] = {
2250         {"trf7970a", 0},
2251         {}
2252 };
2253 
2254 MODULE_DEVICE_TABLE(spi, trf7970a_id_table);
2255 
2256 static struct spi_driver trf7970a_spi_driver = {
2257         .probe          = trf7970a_probe,
2258         .remove         = trf7970a_remove,
2259         .id_table       = trf7970a_id_table,
2260         .driver = {
2261                 .name           = "trf7970a",
2262                 .of_match_table = of_match_ptr(trf7970a_of_match),
2263                 .pm             = &trf7970a_pm_ops,
2264         },
2265 };
2266 
2267 module_spi_driver(trf7970a_spi_driver);
2268 
2269 MODULE_AUTHOR("Mark A. Greer <mgreer@animalcreek.com>");
2270 MODULE_LICENSE("GPL v2");
2271 MODULE_DESCRIPTION("TI trf7970a RFID/NFC Transceiver Driver");
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/nfc/trf7970a.c

DEFINITIONS
