drivers/nfc/trf7970a.c

   1 /*
   2  * TI TRF7970a RFID/NFC Transceiver Driver
   3  *
   4  * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
   5  *
   6  * Author: Erick Macias <emacias@ti.com>
   7  * Author: Felipe Balbi <balbi@ti.com>
   8  * Author: Mark A. Greer <mgreer@animalcreek.com>
   9  *
  10  * This program is free software: you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2  of
  12  * the License as published by the Free Software Foundation.
  13  */
  14
  15 #include <linux/module.h>
  16 #include <linux/device.h>
  17 #include <linux/netdevice.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/pm_runtime.h>
  20 #include <linux/nfc.h>
  21 #include <linux/skbuff.h>
  22 #include <linux/delay.h>
  23 #include <linux/gpio.h>
  24 #include <linux/of.h>
  25 #include <linux/of_gpio.h>
  26 #include <linux/spi/spi.h>
  27 #include <linux/regulator/consumer.h>
  28
  29 #include <net/nfc/nfc.h>
  30 #include <net/nfc/digital.h>
  31
  32 /* There are 3 ways the host can communicate with the trf7970a:
  33  * parallel mode, SPI with Slave Select (SS) mode, and SPI without
  34  * SS mode.  The driver only supports the two SPI modes.
  35  *
  36  * The trf7970a is very timing sensitive and the VIN, EN2, and EN
  37  * pins must asserted in that order and with specific delays in between.
  38  * The delays used in the driver were provided by TI and have been
  39  * confirmed to work with this driver.  There is a bug with the current
  40  * version of the trf7970a that requires that EN2 remain low no matter
  41  * what.  If it goes high, it will generate an RF field even when in
  42  * passive target mode.  TI has indicated that the chip will work okay
  43  * when EN2 is left low.  The 'en2-rf-quirk' device tree property
  44  * indicates that trf7970a currently being used has the erratum and
  45  * that EN2 must be kept low.
  46  *
  47  * Timeouts are implemented using the delayed workqueue kernel facility.
  48  * Timeouts are required so things don't hang when there is no response
  49  * from the trf7970a (or tag).  Using this mechanism creates a race with
  50  * interrupts, however.  That is, an interrupt and a timeout could occur
  51  * closely enough together that one is blocked by the mutex while the other
  52  * executes.  When the timeout handler executes first and blocks the
  53  * interrupt handler, it will eventually set the state to IDLE so the
  54  * interrupt handler will check the state and exit with no harm done.
  55  * When the interrupt handler executes first and blocks the timeout handler,
  56  * the cancel_delayed_work() call will know that it didn't cancel the
  57  * work item (i.e., timeout) and will return zero.  That return code is
  58  * used by the timer handler to indicate that it should ignore the timeout
  59  * once its unblocked.
  60  *
  61  * Aborting an active command isn't as simple as it seems because the only
  62  * way to abort a command that's already been sent to the tag is so turn
  63  * off power to the tag.  If we do that, though, we'd have to go through
  64  * the entire anticollision procedure again but the digital layer doesn't
  65  * support that.  So, if an abort is received before trf7970a_send_cmd()
  66  * has sent the command to the tag, it simply returns -ECANCELED.  If the
  67  * command has already been sent to the tag, then the driver continues
  68  * normally and recieves the response data (or error) but just before
  69  * sending the data upstream, it frees the rx_skb and sends -ECANCELED
  70  * upstream instead.  If the command failed, that error will be sent
  71  * upstream.
  72  *
  73  * When recieving data from a tag and the interrupt status register has
  74  * only the SRX bit set, it means that all of the data has been received
  75  * (once what's in the fifo has been read).  However, depending on timing
  76  * an interrupt status with only the SRX bit set may not be recived.  In
  77  * those cases, the timeout mechanism is used to wait 20 ms in case more
  78  * data arrives.  After 20 ms, it is assumed that all of the data has been
  79  * received and the accumulated rx data is sent upstream.  The
  80  * 'TRF7970A_ST_WAIT_FOR_RX_DATA_CONT' state is used for this purpose
  81  * (i.e., it indicates that some data has been received but we're not sure
  82  * if there is more coming so a timeout in this state means all data has
  83  * been received and there isn't an error).  The delay is 20 ms since delays
  84  * of ~16 ms have been observed during testing.
  85  *
  86  * When transmitting a frame larger than the FIFO size (127 bytes), the
  87  * driver will wait 20 ms for the FIFO to drain past the low-watermark
  88  * and generate an interrupt.  The low-watermark set to 32 bytes so the
  89  * interrupt should fire after 127 - 32 = 95 bytes have been sent.  At
  90  * the lowest possible bit rate (6.62 kbps for 15693), it will take up
  91  * to ~14.35 ms so 20 ms is used for the timeout.
  92  *
  93  * Type 2 write and sector select commands respond with a 4-bit ACK or NACK.
  94  * Having only 4 bits in the FIFO won't normally generate an interrupt so
  95  * driver enables the '4_bit_RX' bit of the Special Functions register 1
  96  * to cause an interrupt in that case.  Leaving that bit for a read command
  97  * messes up the data returned so it is only enabled when the framing is
  98  * 'NFC_DIGITAL_FRAMING_NFCA_T2T' and the command is not a read command.
  99  * Unfortunately, that means that the driver has to peek into tx frames
 100  * when the framing is 'NFC_DIGITAL_FRAMING_NFCA_T2T'.  This is done by
 101  * the trf7970a_per_cmd_config() routine.
 102  *
 103  * ISO/IEC 15693 frames specify whether to use single or double sub-carrier
 104  * frequencies and whether to use low or high data rates in the flags byte
 105  * of the frame.  This means that the driver has to peek at all 15693 frames
 106  * to determine what speed to set the communication to.  In addition, write
 107  * and lock commands use the OPTION flag to indicate that an EOF must be
 108  * sent to the tag before it will send its response.  So the driver has to
 109  * examine all frames for that reason too.
 110  *
 111  * It is unclear how long to wait before sending the EOF.  According to the
 112  * Note under Table 1-1 in section 1.6 of
 113  * http://www.ti.com/lit/ug/scbu011/scbu011.pdf, that wait should be at least
 114  * 10 ms for TI Tag-it HF-I tags; however testing has shown that is not long
 115  * enough so 20 ms is used.  So the timer is set to 40 ms - 20 ms to drain
 116  * up to 127 bytes in the FIFO at the lowest bit rate plus another 20 ms to
 117  * ensure the wait is long enough before sending the EOF.  This seems to work
 118  * reliably.
 119  */
 120
 121 #define TRF7970A_SUPPORTED_PROTOCOLS \
 122                 (NFC_PROTO_MIFARE_MASK | NFC_PROTO_ISO14443_MASK |      \
 123                  NFC_PROTO_ISO14443_B_MASK | NFC_PROTO_FELICA_MASK | \
 124                  NFC_PROTO_ISO15693_MASK | NFC_PROTO_NFC_DEP_MASK)
 125
 126 #define TRF7970A_AUTOSUSPEND_DELAY              30000 /* 30 seconds */
 127 #define TRF7970A_13MHZ_CLOCK_FREQUENCY          13560000
 128 #define TRF7970A_27MHZ_CLOCK_FREQUENCY          27120000
 129
 130
 131 #define TRF7970A_RX_SKB_ALLOC_SIZE              256
 132
 133 #define TRF7970A_FIFO_SIZE                      127
 134
 135 /* TX length is 3 nibbles long ==> 4KB - 1 bytes max */
 136 #define TRF7970A_TX_MAX                         (4096 - 1)
 137
 138 #define TRF7970A_WAIT_FOR_TX_IRQ                20
 139 #define TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT       20
 140 #define TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT    20
 141 #define TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF     40
 142
 143 /* Guard times for various RF technologies (in us) */
 144 #define TRF7970A_GUARD_TIME_NFCA                5000
 145 #define TRF7970A_GUARD_TIME_NFCB                5000
 146 #define TRF7970A_GUARD_TIME_NFCF                20000
 147 #define TRF7970A_GUARD_TIME_15693               1000
 148
 149 /* Quirks */
 150 /* Erratum: When reading IRQ Status register on trf7970a, we must issue a
 151  * read continuous command for IRQ Status and Collision Position registers.
 152  */
 153 #define TRF7970A_QUIRK_IRQ_STATUS_READ          BIT(0)
 154 #define TRF7970A_QUIRK_EN2_MUST_STAY_LOW        BIT(1)
 155 #define TRF7970A_QUIRK_T5T_RMB_EXTRA_BYTE       BIT(2)
 156
 157 /* Direct commands */
 158 #define TRF7970A_CMD_IDLE                       0x00
 159 #define TRF7970A_CMD_SOFT_INIT                  0x03
 160 #define TRF7970A_CMD_RF_COLLISION               0x04
 161 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_N    0x05
 162 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_0    0x06
 163 #define TRF7970A_CMD_FIFO_RESET                 0x0f
 164 #define TRF7970A_CMD_TRANSMIT_NO_CRC            0x10
 165 #define TRF7970A_CMD_TRANSMIT                   0x11
 166 #define TRF7970A_CMD_DELAY_TRANSMIT_NO_CRC      0x12
 167 #define TRF7970A_CMD_DELAY_TRANSMIT             0x13
 168 #define TRF7970A_CMD_EOF                        0x14
 169 #define TRF7970A_CMD_CLOSE_SLOT                 0x15
 170 #define TRF7970A_CMD_BLOCK_RX                   0x16
 171 #define TRF7970A_CMD_ENABLE_RX                  0x17
 172 #define TRF7970A_CMD_TEST_INT_RF                0x18
 173 #define TRF7970A_CMD_TEST_EXT_RF                0x19
 174 #define TRF7970A_CMD_RX_GAIN_ADJUST             0x1a
 175
 176 /* Bits determining whether its a direct command or register R/W,
 177  * whether to use a continuous SPI transaction or not, and the actual
 178  * direct cmd opcode or regster address.
 179  */
 180 #define TRF7970A_CMD_BIT_CTRL                   BIT(7)
 181 #define TRF7970A_CMD_BIT_RW                     BIT(6)
 182 #define TRF7970A_CMD_BIT_CONTINUOUS             BIT(5)
 183 #define TRF7970A_CMD_BIT_OPCODE(opcode)         ((opcode) & 0x1f)
 184
 185 /* Registers addresses */
 186 #define TRF7970A_CHIP_STATUS_CTRL               0x00
 187 #define TRF7970A_ISO_CTRL                       0x01
 188 #define TRF7970A_ISO14443B_TX_OPTIONS           0x02
 189 #define TRF7970A_ISO14443A_HIGH_BITRATE_OPTIONS 0x03
 190 #define TRF7970A_TX_TIMER_SETTING_H_BYTE        0x04
 191 #define TRF7970A_TX_TIMER_SETTING_L_BYTE        0x05
 192 #define TRF7970A_TX_PULSE_LENGTH_CTRL           0x06
 193 #define TRF7970A_RX_NO_RESPONSE_WAIT            0x07
 194 #define TRF7970A_RX_WAIT_TIME                   0x08
 195 #define TRF7970A_MODULATOR_SYS_CLK_CTRL         0x09
 196 #define TRF7970A_RX_SPECIAL_SETTINGS            0x0a
 197 #define TRF7970A_REG_IO_CTRL                    0x0b
 198 #define TRF7970A_IRQ_STATUS                     0x0c
 199 #define TRF7970A_COLLISION_IRQ_MASK             0x0d
 200 #define TRF7970A_COLLISION_POSITION             0x0e
 201 #define TRF7970A_RSSI_OSC_STATUS                0x0f
 202 #define TRF7970A_SPECIAL_FCN_REG1               0x10
 203 #define TRF7970A_SPECIAL_FCN_REG2               0x11
 204 #define TRF7970A_RAM1                           0x12
 205 #define TRF7970A_RAM2                           0x13
 206 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS      0x14
 207 #define TRF7970A_NFC_LOW_FIELD_LEVEL            0x16
 208 #define TRF7970A_NFCID1                         0x17
 209 #define TRF7970A_NFC_TARGET_LEVEL               0x18
 210 #define TRF79070A_NFC_TARGET_PROTOCOL           0x19
 211 #define TRF7970A_TEST_REGISTER1                 0x1a
 212 #define TRF7970A_TEST_REGISTER2                 0x1b
 213 #define TRF7970A_FIFO_STATUS                    0x1c
 214 #define TRF7970A_TX_LENGTH_BYTE1                0x1d
 215 #define TRF7970A_TX_LENGTH_BYTE2                0x1e
 216 #define TRF7970A_FIFO_IO_REGISTER               0x1f
 217
 218 /* Chip Status Control Register Bits */
 219 #define TRF7970A_CHIP_STATUS_VRS5_3             BIT(0)
 220 #define TRF7970A_CHIP_STATUS_REC_ON             BIT(1)
 221 #define TRF7970A_CHIP_STATUS_AGC_ON             BIT(2)
 222 #define TRF7970A_CHIP_STATUS_PM_ON              BIT(3)
 223 #define TRF7970A_CHIP_STATUS_RF_PWR             BIT(4)
 224 #define TRF7970A_CHIP_STATUS_RF_ON              BIT(5)
 225 #define TRF7970A_CHIP_STATUS_DIRECT             BIT(6)
 226 #define TRF7970A_CHIP_STATUS_STBY               BIT(7)
 227
 228 /* ISO Control Register Bits */
 229 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_662    0x00
 230 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_662  0x01
 231 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648   0x02
 232 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_2648 0x03
 233 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a   0x04
 234 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_667  0x05
 235 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669   0x06
 236 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_2669 0x07
 237 #define TRF7970A_ISO_CTRL_14443A_106            0x08
 238 #define TRF7970A_ISO_CTRL_14443A_212            0x09
 239 #define TRF7970A_ISO_CTRL_14443A_424            0x0a
 240 #define TRF7970A_ISO_CTRL_14443A_848            0x0b
 241 #define TRF7970A_ISO_CTRL_14443B_106            0x0c
 242 #define TRF7970A_ISO_CTRL_14443B_212            0x0d
 243 #define TRF7970A_ISO_CTRL_14443B_424            0x0e
 244 #define TRF7970A_ISO_CTRL_14443B_848            0x0f
 245 #define TRF7970A_ISO_CTRL_FELICA_212            0x1a
 246 #define TRF7970A_ISO_CTRL_FELICA_424            0x1b
 247 #define TRF7970A_ISO_CTRL_NFC_NFCA_106          0x01
 248 #define TRF7970A_ISO_CTRL_NFC_NFCF_212          0x02
 249 #define TRF7970A_ISO_CTRL_NFC_NFCF_424          0x03
 250 #define TRF7970A_ISO_CTRL_NFC_CE_14443A         0x00
 251 #define TRF7970A_ISO_CTRL_NFC_CE_14443B         0x01
 252 #define TRF7970A_ISO_CTRL_NFC_CE                BIT(2)
 253 #define TRF7970A_ISO_CTRL_NFC_ACTIVE            BIT(3)
 254 #define TRF7970A_ISO_CTRL_NFC_INITIATOR         BIT(4)
 255 #define TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE       BIT(5)
 256 #define TRF7970A_ISO_CTRL_RFID                  BIT(5)
 257 #define TRF7970A_ISO_CTRL_DIR_MODE              BIT(6)
 258 #define TRF7970A_ISO_CTRL_RX_CRC_N              BIT(7)  /* true == No CRC */
 259
 260 #define TRF7970A_ISO_CTRL_RFID_SPEED_MASK       0x1f
 261
 262 /* Modulator and SYS_CLK Control Register Bits */
 263 #define TRF7970A_MODULATOR_DEPTH(n)             ((n) & 0x7)
 264 #define TRF7970A_MODULATOR_DEPTH_ASK10          (TRF7970A_MODULATOR_DEPTH(0))
 265 #define TRF7970A_MODULATOR_DEPTH_OOK            (TRF7970A_MODULATOR_DEPTH(1))
 266 #define TRF7970A_MODULATOR_DEPTH_ASK7           (TRF7970A_MODULATOR_DEPTH(2))
 267 #define TRF7970A_MODULATOR_DEPTH_ASK8_5         (TRF7970A_MODULATOR_DEPTH(3))
 268 #define TRF7970A_MODULATOR_DEPTH_ASK13          (TRF7970A_MODULATOR_DEPTH(4))
 269 #define TRF7970A_MODULATOR_DEPTH_ASK16          (TRF7970A_MODULATOR_DEPTH(5))
 270 #define TRF7970A_MODULATOR_DEPTH_ASK22          (TRF7970A_MODULATOR_DEPTH(6))
 271 #define TRF7970A_MODULATOR_DEPTH_ASK30          (TRF7970A_MODULATOR_DEPTH(7))
 272 #define TRF7970A_MODULATOR_EN_ANA               BIT(3)
 273 #define TRF7970A_MODULATOR_CLK(n)               (((n) & 0x3) << 4)
 274 #define TRF7970A_MODULATOR_CLK_DISABLED         (TRF7970A_MODULATOR_CLK(0))
 275 #define TRF7970A_MODULATOR_CLK_3_6              (TRF7970A_MODULATOR_CLK(1))
 276 #define TRF7970A_MODULATOR_CLK_6_13             (TRF7970A_MODULATOR_CLK(2))
 277 #define TRF7970A_MODULATOR_CLK_13_27            (TRF7970A_MODULATOR_CLK(3))
 278 #define TRF7970A_MODULATOR_EN_OOK               BIT(6)
 279 #define TRF7970A_MODULATOR_27MHZ                BIT(7)
 280
 281 #define TRF7970A_RX_SPECIAL_SETTINGS_NO_LIM     BIT(0)
 282 #define TRF7970A_RX_SPECIAL_SETTINGS_AGCR       BIT(1)
 283 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_0DB     (0x0 << 2)
 284 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_5DB     (0x1 << 2)
 285 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_10DB    (0x2 << 2)
 286 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_15DB    (0x3 << 2)
 287 #define TRF7970A_RX_SPECIAL_SETTINGS_HBT        BIT(4)
 288 #define TRF7970A_RX_SPECIAL_SETTINGS_M848       BIT(5)
 289 #define TRF7970A_RX_SPECIAL_SETTINGS_C424       BIT(6)
 290 #define TRF7970A_RX_SPECIAL_SETTINGS_C212       BIT(7)
 291
 292 #define TRF7970A_REG_IO_CTRL_VRS(v)             ((v) & 0x07)
 293 #define TRF7970A_REG_IO_CTRL_IO_LOW             BIT(5)
 294 #define TRF7970A_REG_IO_CTRL_EN_EXT_PA          BIT(6)
 295 #define TRF7970A_REG_IO_CTRL_AUTO_REG           BIT(7)
 296
 297 /* IRQ Status Register Bits */
 298 #define TRF7970A_IRQ_STATUS_NORESP              BIT(0) /* ISO15693 only */
 299 #define TRF7970A_IRQ_STATUS_NFC_COL_ERROR       BIT(0)
 300 #define TRF7970A_IRQ_STATUS_COL                 BIT(1)
 301 #define TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR   BIT(2)
 302 #define TRF7970A_IRQ_STATUS_NFC_RF              BIT(2)
 303 #define TRF7970A_IRQ_STATUS_PARITY_ERROR        BIT(3)
 304 #define TRF7970A_IRQ_STATUS_NFC_SDD             BIT(3)
 305 #define TRF7970A_IRQ_STATUS_CRC_ERROR           BIT(4)
 306 #define TRF7970A_IRQ_STATUS_NFC_PROTO_ERROR     BIT(4)
 307 #define TRF7970A_IRQ_STATUS_FIFO                BIT(5)
 308 #define TRF7970A_IRQ_STATUS_SRX                 BIT(6)
 309 #define TRF7970A_IRQ_STATUS_TX                  BIT(7)
 310
 311 #define TRF7970A_IRQ_STATUS_ERROR                               \
 312                 (TRF7970A_IRQ_STATUS_COL |                      \
 313                  TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR |        \
 314                  TRF7970A_IRQ_STATUS_PARITY_ERROR |             \
 315                  TRF7970A_IRQ_STATUS_CRC_ERROR)
 316
 317 #define TRF7970A_RSSI_OSC_STATUS_RSSI_MASK      (BIT(2) | BIT(1) | BIT(0))
 318 #define TRF7970A_RSSI_OSC_STATUS_RSSI_X_MASK    (BIT(5) | BIT(4) | BIT(3))
 319 #define TRF7970A_RSSI_OSC_STATUS_RSSI_OSC_OK    BIT(6)
 320
 321 #define TRF7970A_SPECIAL_FCN_REG1_COL_7_6               BIT(0)
 322 #define TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL           BIT(1)
 323 #define TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX              BIT(2)
 324 #define TRF7970A_SPECIAL_FCN_REG1_SP_DIR_MODE           BIT(3)
 325 #define TRF7970A_SPECIAL_FCN_REG1_NEXT_SLOT_37US        BIT(4)
 326 #define TRF7970A_SPECIAL_FCN_REG1_PAR43                 BIT(5)
 327
 328 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_124      (0x0 << 2)
 329 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_120      (0x1 << 2)
 330 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_112      (0x2 << 2)
 331 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96       (0x3 << 2)
 332 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_4        0x0
 333 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_8        0x1
 334 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_16       0x2
 335 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32       0x3
 336
 337 #define TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(v)   ((v) & 0x07)
 338 #define TRF7970A_NFC_LOW_FIELD_LEVEL_CLEX_DIS   BIT(7)
 339
 340 #define TRF7970A_NFC_TARGET_LEVEL_RFDET(v)      ((v) & 0x07)
 341 #define TRF7970A_NFC_TARGET_LEVEL_HI_RF         BIT(3)
 342 #define TRF7970A_NFC_TARGET_LEVEL_SDD_EN        BIT(5)
 343 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_4BYTES   (0x0 << 6)
 344 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_7BYTES   (0x1 << 6)
 345 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_10BYTES  (0x2 << 6)
 346
 347 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106         BIT(0)
 348 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212         BIT(1)
 349 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424         (BIT(0) | BIT(1))
 350 #define TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B        BIT(2)
 351 #define TRF79070A_NFC_TARGET_PROTOCOL_PAS_106           BIT(3)
 352 #define TRF79070A_NFC_TARGET_PROTOCOL_FELICA            BIT(4)
 353 #define TRF79070A_NFC_TARGET_PROTOCOL_RF_L              BIT(6)
 354 #define TRF79070A_NFC_TARGET_PROTOCOL_RF_H              BIT(7)
 355
 356 #define TRF79070A_NFC_TARGET_PROTOCOL_106A              \
 357          (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |          \
 358           TRF79070A_NFC_TARGET_PROTOCOL_RF_L |          \
 359           TRF79070A_NFC_TARGET_PROTOCOL_PAS_106 |       \
 360           TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
 361
 362 #define TRF79070A_NFC_TARGET_PROTOCOL_106B              \
 363          (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |          \
 364           TRF79070A_NFC_TARGET_PROTOCOL_RF_L |          \
 365           TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B |    \
 366           TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
 367
 368 #define TRF79070A_NFC_TARGET_PROTOCOL_212F              \
 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_212)
 373
 374 #define TRF79070A_NFC_TARGET_PROTOCOL_424F              \
 375          (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |          \
 376           TRF79070A_NFC_TARGET_PROTOCOL_RF_L |          \
 377           TRF79070A_NFC_TARGET_PROTOCOL_FELICA |        \
 378           TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424)
 379
 380 #define TRF7970A_FIFO_STATUS_OVERFLOW           BIT(7)
 381
 382 /* NFC (ISO/IEC 14443A) Type 2 Tag commands */
 383 #define NFC_T2T_CMD_READ                        0x30
 384
 385 /* ISO 15693 commands codes */
 386 #define ISO15693_CMD_INVENTORY                  0x01
 387 #define ISO15693_CMD_READ_SINGLE_BLOCK          0x20
 388 #define ISO15693_CMD_WRITE_SINGLE_BLOCK         0x21
 389 #define ISO15693_CMD_LOCK_BLOCK                 0x22
 390 #define ISO15693_CMD_READ_MULTIPLE_BLOCK        0x23
 391 #define ISO15693_CMD_WRITE_MULTIPLE_BLOCK       0x24
 392 #define ISO15693_CMD_SELECT                     0x25
 393 #define ISO15693_CMD_RESET_TO_READY             0x26
 394 #define ISO15693_CMD_WRITE_AFI                  0x27
 395 #define ISO15693_CMD_LOCK_AFI                   0x28
 396 #define ISO15693_CMD_WRITE_DSFID                0x29
 397 #define ISO15693_CMD_LOCK_DSFID                 0x2a
 398 #define ISO15693_CMD_GET_SYSTEM_INFO            0x2b
 399 #define ISO15693_CMD_GET_MULTIPLE_BLOCK_SECURITY_STATUS 0x2c
 400
 401 /* ISO 15693 request and response flags */
 402 #define ISO15693_REQ_FLAG_SUB_CARRIER           BIT(0)
 403 #define ISO15693_REQ_FLAG_DATA_RATE             BIT(1)
 404 #define ISO15693_REQ_FLAG_INVENTORY             BIT(2)
 405 #define ISO15693_REQ_FLAG_PROTOCOL_EXT          BIT(3)
 406 #define ISO15693_REQ_FLAG_SELECT                BIT(4)
 407 #define ISO15693_REQ_FLAG_AFI                   BIT(4)
 408 #define ISO15693_REQ_FLAG_ADDRESS               BIT(5)
 409 #define ISO15693_REQ_FLAG_NB_SLOTS              BIT(5)
 410 #define ISO15693_REQ_FLAG_OPTION                BIT(6)
 411
 412 #define ISO15693_REQ_FLAG_SPEED_MASK \
 413                 (ISO15693_REQ_FLAG_SUB_CARRIER | ISO15693_REQ_FLAG_DATA_RATE)
 414
 415 enum trf7970a_state {
 416         TRF7970A_ST_PWR_OFF,
 417         TRF7970A_ST_RF_OFF,
 418         TRF7970A_ST_IDLE,
 419         TRF7970A_ST_IDLE_RX_BLOCKED,
 420         TRF7970A_ST_WAIT_FOR_TX_FIFO,
 421         TRF7970A_ST_WAIT_FOR_RX_DATA,
 422         TRF7970A_ST_WAIT_FOR_RX_DATA_CONT,
 423         TRF7970A_ST_WAIT_TO_ISSUE_EOF,
 424         TRF7970A_ST_LISTENING,
 425         TRF7970A_ST_LISTENING_MD,
 426         TRF7970A_ST_MAX
 427 };
 428
 429 struct trf7970a {
 430         enum trf7970a_state             state;
 431         struct device                   *dev;
 432         struct spi_device               *spi;
 433         struct regulator                *regulator;
 434         struct nfc_digital_dev          *ddev;
 435         u32                             quirks;
 436         bool                            is_initiator;
 437         bool                            aborting;
 438         struct sk_buff                  *tx_skb;
 439         struct sk_buff                  *rx_skb;
 440         nfc_digital_cmd_complete_t      cb;
 441         void                            *cb_arg;
 442         u8                              chip_status_ctrl;
 443         u8                              iso_ctrl;
 444         u8                              iso_ctrl_tech;
 445         u8                              modulator_sys_clk_ctrl;
 446         u8                              special_fcn_reg1;
 447         u8                              io_ctrl;
 448         unsigned int                    guard_time;
 449         int                             technology;
 450         int                             framing;
 451         u8                              md_rf_tech;
 452         u8                              tx_cmd;
 453         bool                            issue_eof;
 454         bool                            adjust_resp_len;
 455         int                             en2_gpio;
 456         int                             en_gpio;
 457         struct mutex                    lock;
 458         unsigned int                    timeout;
 459         bool                            ignore_timeout;
 460         struct delayed_work             timeout_work;
 461 };
 462
 463
 464 static int trf7970a_cmd(struct trf7970a *trf, u8 opcode)
 465 {
 466         u8 cmd = TRF7970A_CMD_BIT_CTRL | TRF7970A_CMD_BIT_OPCODE(opcode);
 467         int ret;
 468
 469         dev_dbg(trf->dev, "cmd: 0x%x\n", cmd);
 470
 471         ret = spi_write(trf->spi, &cmd, 1);
 472         if (ret)
 473                 dev_err(trf->dev, "%s - cmd: 0x%x, ret: %d\n", __func__, cmd,
 474                                 ret);
 475         return ret;
 476 }
 477
 478 static int trf7970a_read(struct trf7970a *trf, u8 reg, u8 *val)
 479 {
 480         u8 addr = TRF7970A_CMD_BIT_RW | reg;
 481         int ret;
 482
 483         ret = spi_write_then_read(trf->spi, &addr, 1, val, 1);
 484         if (ret)
 485                 dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
 486                                 ret);
 487
 488         dev_dbg(trf->dev, "read(0x%x): 0x%x\n", addr, *val);
 489
 490         return ret;
 491 }
 492
 493 static int trf7970a_read_cont(struct trf7970a *trf, u8 reg, u8 *buf, size_t len)
 494 {
 495         u8 addr = reg | TRF7970A_CMD_BIT_RW | TRF7970A_CMD_BIT_CONTINUOUS;
 496         struct spi_transfer t[2];
 497         struct spi_message m;
 498         int ret;
 499
 500         dev_dbg(trf->dev, "read_cont(0x%x, %zd)\n", addr, len);
 501
 502         spi_message_init(&m);
 503
 504         memset(&t, 0, sizeof(t));
 505
 506         t[0].tx_buf = &addr;
 507         t[0].len = sizeof(addr);
 508         spi_message_add_tail(&t[0], &m);
 509
 510         t[1].rx_buf = buf;
 511         t[1].len = len;
 512         spi_message_add_tail(&t[1], &m);
 513
 514         ret = spi_sync(trf->spi, &m);
 515         if (ret)
 516                 dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
 517                                 ret);
 518         return ret;
 519 }
 520
 521 static int trf7970a_write(struct trf7970a *trf, u8 reg, u8 val)
 522 {
 523         u8 buf[2] = { reg, val };
 524         int ret;
 525
 526         dev_dbg(trf->dev, "write(0x%x): 0x%x\n", reg, val);
 527
 528         ret = spi_write(trf->spi, buf, 2);
 529         if (ret)
 530                 dev_err(trf->dev, "%s - write: 0x%x 0x%x, ret: %d\n", __func__,
 531                                 buf[0], buf[1], ret);
 532
 533         return ret;
 534 }
 535
 536 static int trf7970a_read_irqstatus(struct trf7970a *trf, u8 *status)
 537 {
 538         int ret;
 539         u8 buf[2];
 540         u8 addr;
 541
 542         addr = TRF7970A_IRQ_STATUS | TRF7970A_CMD_BIT_RW;
 543
 544         if (trf->quirks & TRF7970A_QUIRK_IRQ_STATUS_READ) {
 545                 addr |= TRF7970A_CMD_BIT_CONTINUOUS;
 546                 ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
 547         } else {
 548                 ret = spi_write_then_read(trf->spi, &addr, 1, buf, 1);
 549         }
 550
 551         if (ret)
 552                 dev_err(trf->dev, "%s - irqstatus: Status read failed: %d\n",
 553                                 __func__, ret);
 554         else
 555                 *status = buf[0];
 556
 557         return ret;
 558 }
 559
 560 static int trf7970a_read_target_proto(struct trf7970a *trf, u8 *target_proto)
 561 {
 562         int ret;
 563         u8 buf[2];
 564         u8 addr;
 565
 566         addr = TRF79070A_NFC_TARGET_PROTOCOL | TRF7970A_CMD_BIT_RW |
 567                 TRF7970A_CMD_BIT_CONTINUOUS;
 568
 569         ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
 570         if (ret)
 571                 dev_err(trf->dev, "%s - target_proto: Read failed: %d\n",
 572                                 __func__, ret);
 573         else
 574                 *target_proto = buf[0];
 575
 576         return ret;
 577 }
 578
 579 static int trf7970a_mode_detect(struct trf7970a *trf, u8 *rf_tech)
 580 {
 581         int ret;
 582         u8 target_proto, tech;
 583
 584         ret = trf7970a_read_target_proto(trf, &target_proto);
 585         if (ret)
 586                 return ret;
 587
 588         switch (target_proto) {
 589         case TRF79070A_NFC_TARGET_PROTOCOL_106A:
 590                 tech = NFC_DIGITAL_RF_TECH_106A;
 591                 break;
 592         case TRF79070A_NFC_TARGET_PROTOCOL_106B:
 593                 tech = NFC_DIGITAL_RF_TECH_106B;
 594                 break;
 595         case TRF79070A_NFC_TARGET_PROTOCOL_212F:
 596                 tech = NFC_DIGITAL_RF_TECH_212F;
 597                 break;
 598         case TRF79070A_NFC_TARGET_PROTOCOL_424F:
 599                 tech = NFC_DIGITAL_RF_TECH_424F;
 600                 break;
 601         default:
 602                 dev_dbg(trf->dev, "%s - mode_detect: target_proto: 0x%x\n",
 603                                 __func__, target_proto);
 604                 return -EIO;
 605         }
 606
 607         *rf_tech = tech;
 608
 609         return ret;
 610 }
 611
 612 static void trf7970a_send_upstream(struct trf7970a *trf)
 613 {
 614         dev_kfree_skb_any(trf->tx_skb);
 615         trf->tx_skb = NULL;
 616
 617         if (trf->rx_skb && !IS_ERR(trf->rx_skb) && !trf->aborting)
 618                 print_hex_dump_debug("trf7970a rx data: ", DUMP_PREFIX_NONE,
 619                                 16, 1, trf->rx_skb->data, trf->rx_skb->len,
 620                                 false);
 621
 622         trf->state = TRF7970A_ST_IDLE;
 623
 624         if (trf->aborting) {
 625                 dev_dbg(trf->dev, "Abort process complete\n");
 626
 627                 if (!IS_ERR(trf->rx_skb)) {
 628                         kfree_skb(trf->rx_skb);
 629                         trf->rx_skb = ERR_PTR(-ECANCELED);
 630                 }
 631
 632                 trf->aborting = false;
 633         }
 634
 635         if (trf->adjust_resp_len) {
 636                 if (trf->rx_skb)
 637                         skb_trim(trf->rx_skb, trf->rx_skb->len - 1);
 638
 639                 trf->adjust_resp_len = false;
 640         }
 641
 642         trf->cb(trf->ddev, trf->cb_arg, trf->rx_skb);
 643
 644         trf->rx_skb = NULL;
 645 }
 646
 647 static void trf7970a_send_err_upstream(struct trf7970a *trf, int errno)
 648 {
 649         dev_dbg(trf->dev, "Error - state: %d, errno: %d\n", trf->state, errno);
 650
 651         cancel_delayed_work(&trf->timeout_work);
 652
 653         kfree_skb(trf->rx_skb);
 654         trf->rx_skb = ERR_PTR(errno);
 655
 656         trf7970a_send_upstream(trf);
 657 }
 658
 659 static int trf7970a_transmit(struct trf7970a *trf, struct sk_buff *skb,
 660                 unsigned int len, u8 *prefix, unsigned int prefix_len)
 661 {
 662         struct spi_transfer t[2];
 663         struct spi_message m;
 664         unsigned int timeout;
 665         int ret;
 666
 667         print_hex_dump_debug("trf7970a tx data: ", DUMP_PREFIX_NONE,
 668                         16, 1, skb->data, len, false);
 669
 670         spi_message_init(&m);
 671
 672         memset(&t, 0, sizeof(t));
 673
 674         t[0].tx_buf = prefix;
 675         t[0].len = prefix_len;
 676         spi_message_add_tail(&t[0], &m);
 677
 678         t[1].tx_buf = skb->data;
 679         t[1].len = len;
 680         spi_message_add_tail(&t[1], &m);
 681
 682         ret = spi_sync(trf->spi, &m);
 683         if (ret) {
 684                 dev_err(trf->dev, "%s - Can't send tx data: %d\n", __func__,
 685                                 ret);
 686                 return ret;
 687         }
 688
 689         skb_pull(skb, len);
 690
 691         if (skb->len > 0) {
 692                 trf->state = TRF7970A_ST_WAIT_FOR_TX_FIFO;
 693                 timeout = TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT;
 694         } else {
 695                 if (trf->issue_eof) {
 696                         trf->state = TRF7970A_ST_WAIT_TO_ISSUE_EOF;
 697                         timeout = TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF;
 698                 } else {
 699                         trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
 700
 701                         if (!trf->timeout)
 702                                 timeout = TRF7970A_WAIT_FOR_TX_IRQ;
 703                         else
 704                                 timeout = trf->timeout;
 705                 }
 706         }
 707
 708         dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n", timeout,
 709                         trf->state);
 710
 711         schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
 712
 713         return 0;
 714 }
 715
 716 static void trf7970a_fill_fifo(struct trf7970a *trf)
 717 {
 718         struct sk_buff *skb = trf->tx_skb;
 719         unsigned int len;
 720         int ret;
 721         u8 fifo_bytes;
 722         u8 prefix;
 723
 724         ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
 725         if (ret) {
 726                 trf7970a_send_err_upstream(trf, ret);
 727                 return;
 728         }
 729
 730         dev_dbg(trf->dev, "Filling FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
 731
 732         fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 733
 734         /* Calculate how much more data can be written to the fifo */
 735         len = TRF7970A_FIFO_SIZE - fifo_bytes;
 736         if (!len) {
 737                 schedule_delayed_work(&trf->timeout_work,
 738                         msecs_to_jiffies(TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT));
 739                 return;
 740         }
 741
 742         len = min(skb->len, len);
 743
 744         prefix = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_FIFO_IO_REGISTER;
 745
 746         ret = trf7970a_transmit(trf, skb, len, &prefix, sizeof(prefix));
 747         if (ret)
 748                 trf7970a_send_err_upstream(trf, ret);
 749 }
 750
 751 static void trf7970a_drain_fifo(struct trf7970a *trf, u8 status)
 752 {
 753         struct sk_buff *skb = trf->rx_skb;
 754         int ret;
 755         u8 fifo_bytes;
 756
 757         if (status & TRF7970A_IRQ_STATUS_ERROR) {
 758                 trf7970a_send_err_upstream(trf, -EIO);
 759                 return;
 760         }
 761
 762         ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
 763         if (ret) {
 764                 trf7970a_send_err_upstream(trf, ret);
 765                 return;
 766         }
 767
 768         dev_dbg(trf->dev, "Draining FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
 769
 770         fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 771
 772         if (!fifo_bytes)
 773                 goto no_rx_data;
 774
 775         if (fifo_bytes > skb_tailroom(skb)) {
 776                 skb = skb_copy_expand(skb, skb_headroom(skb),
 777                                 max_t(int, fifo_bytes,
 778                                         TRF7970A_RX_SKB_ALLOC_SIZE),
 779                                 GFP_KERNEL);
 780                 if (!skb) {
 781                         trf7970a_send_err_upstream(trf, -ENOMEM);
 782                         return;
 783                 }
 784
 785                 kfree_skb(trf->rx_skb);
 786                 trf->rx_skb = skb;
 787         }
 788
 789         ret = trf7970a_read_cont(trf, TRF7970A_FIFO_IO_REGISTER,
 790                         skb_put(skb, fifo_bytes), fifo_bytes);
 791         if (ret) {
 792                 trf7970a_send_err_upstream(trf, ret);
 793                 return;
 794         }
 795
 796         /* If received Type 2 ACK/NACK, shift right 4 bits and pass up */
 797         if ((trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T) && (skb->len == 1) &&
 798                         (trf->special_fcn_reg1 ==
 799                                  TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX)) {
 800                 skb->data[0] >>= 4;
 801                 status = TRF7970A_IRQ_STATUS_SRX;
 802         } else {
 803                 trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA_CONT;
 804
 805                 ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
 806                 if (ret) {
 807                         trf7970a_send_err_upstream(trf, ret);
 808                         return;
 809                 }
 810
 811                 fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 812
 813                 /* If there are bytes in the FIFO, set status to '0' so
 814                  * the if stmt below doesn't fire and the driver will wait
 815                  * for the trf7970a to generate another RX interrupt.
 816                  */
 817                 if (fifo_bytes)
 818                         status = 0;
 819         }
 820
 821 no_rx_data:
 822         if (status == TRF7970A_IRQ_STATUS_SRX) { /* Receive complete */
 823                 trf7970a_send_upstream(trf);
 824                 return;
 825         }
 826
 827         dev_dbg(trf->dev, "Setting timeout for %d ms\n",
 828                         TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT);
 829
 830         schedule_delayed_work(&trf->timeout_work,
 831                         msecs_to_jiffies(TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT));
 832 }
 833
 834 static irqreturn_t trf7970a_irq(int irq, void *dev_id)
 835 {
 836         struct trf7970a *trf = dev_id;
 837         int ret;
 838         u8 status, fifo_bytes, iso_ctrl;
 839
 840         mutex_lock(&trf->lock);
 841
 842         if (trf->state == TRF7970A_ST_RF_OFF) {
 843                 mutex_unlock(&trf->lock);
 844                 return IRQ_NONE;
 845         }
 846
 847         ret = trf7970a_read_irqstatus(trf, &status);
 848         if (ret) {
 849                 mutex_unlock(&trf->lock);
 850                 return IRQ_NONE;
 851         }
 852
 853         dev_dbg(trf->dev, "IRQ - state: %d, status: 0x%x\n", trf->state,
 854                         status);
 855
 856         if (!status) {
 857                 mutex_unlock(&trf->lock);
 858                 return IRQ_NONE;
 859         }
 860
 861         switch (trf->state) {
 862         case TRF7970A_ST_IDLE:
 863         case TRF7970A_ST_IDLE_RX_BLOCKED:
 864                 /* If initiator and getting interrupts caused by RF noise,
 865                  * turn off the receiver to avoid unnecessary interrupts.
 866                  * It will be turned back on in trf7970a_send_cmd() when
 867                  * the next command is issued.
 868                  */
 869                 if (trf->is_initiator && (status & TRF7970A_IRQ_STATUS_ERROR)) {
 870                         trf7970a_cmd(trf, TRF7970A_CMD_BLOCK_RX);
 871                         trf->state = TRF7970A_ST_IDLE_RX_BLOCKED;
 872                 }
 873
 874                 trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 875                 break;
 876         case TRF7970A_ST_WAIT_FOR_TX_FIFO:
 877                 if (status & TRF7970A_IRQ_STATUS_TX) {
 878                         trf->ignore_timeout =
 879                                 !cancel_delayed_work(&trf->timeout_work);
 880                         trf7970a_fill_fifo(trf);
 881                 } else {
 882                         trf7970a_send_err_upstream(trf, -EIO);
 883                 }
 884                 break;
 885         case TRF7970A_ST_WAIT_FOR_RX_DATA:
 886         case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
 887                 if (status & TRF7970A_IRQ_STATUS_SRX) {
 888                         trf->ignore_timeout =
 889                                 !cancel_delayed_work(&trf->timeout_work);
 890                         trf7970a_drain_fifo(trf, status);
 891                 } else if (status & TRF7970A_IRQ_STATUS_FIFO) {
 892                         ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS,
 893                                         &fifo_bytes);
 894
 895                         fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 896
 897                         if (ret)
 898                                 trf7970a_send_err_upstream(trf, ret);
 899                         else if (!fifo_bytes)
 900                                 trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 901                 } else if ((status == TRF7970A_IRQ_STATUS_TX) ||
 902                                 (!trf->is_initiator &&
 903                                  (status == (TRF7970A_IRQ_STATUS_TX |
 904                                              TRF7970A_IRQ_STATUS_NFC_RF)))) {
 905                         trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 906
 907                         if (!trf->timeout) {
 908                                 trf->ignore_timeout = !cancel_delayed_work(
 909                                                 &trf->timeout_work);
 910                                 trf->rx_skb = ERR_PTR(0);
 911                                 trf7970a_send_upstream(trf);
 912                                 break;
 913                         }
 914
 915                         if (trf->is_initiator)
 916                                 break;
 917
 918                         iso_ctrl = trf->iso_ctrl;
 919
 920                         switch (trf->framing) {
 921                         case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
 922                                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
 923                                 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
 924                                 trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
 925                                 break;
 926                         case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
 927                                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
 928                                 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
 929                                 trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
 930                                 break;
 931                         case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
 932                                 ret = trf7970a_write(trf,
 933                                         TRF7970A_SPECIAL_FCN_REG1,
 934                                         TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL);
 935                                 if (ret)
 936                                         goto err_unlock_exit;
 937
 938                                 trf->special_fcn_reg1 =
 939                                         TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL;
 940                                 break;
 941                         default:
 942                                 break;
 943                         }
 944
 945                         if (iso_ctrl != trf->iso_ctrl) {
 946                                 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
 947                                                 iso_ctrl);
 948                                 if (ret)
 949                                         goto err_unlock_exit;
 950
 951                                 trf->iso_ctrl = iso_ctrl;
 952                         }
 953                 } else {
 954                         trf7970a_send_err_upstream(trf, -EIO);
 955                 }
 956                 break;
 957         case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
 958                 if (status != TRF7970A_IRQ_STATUS_TX)
 959                         trf7970a_send_err_upstream(trf, -EIO);
 960                 break;
 961         case TRF7970A_ST_LISTENING:
 962                 if (status & TRF7970A_IRQ_STATUS_SRX) {
 963                         trf->ignore_timeout =
 964                                 !cancel_delayed_work(&trf->timeout_work);
 965                         trf7970a_drain_fifo(trf, status);
 966                 } else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
 967                         trf7970a_send_err_upstream(trf, -EIO);
 968                 }
 969                 break;
 970         case TRF7970A_ST_LISTENING_MD:
 971                 if (status & TRF7970A_IRQ_STATUS_SRX) {
 972                         trf->ignore_timeout =
 973                                 !cancel_delayed_work(&trf->timeout_work);
 974
 975                         ret = trf7970a_mode_detect(trf, &trf->md_rf_tech);
 976                         if (ret) {
 977                                 trf7970a_send_err_upstream(trf, ret);
 978                         } else {
 979                                 trf->state = TRF7970A_ST_LISTENING;
 980                                 trf7970a_drain_fifo(trf, status);
 981                         }
 982                 } else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
 983                         trf7970a_send_err_upstream(trf, -EIO);
 984                 }
 985                 break;
 986         default:
 987                 dev_err(trf->dev, "%s - Driver in invalid state: %d\n",
 988                                 __func__, trf->state);
 989         }
 990
 991 err_unlock_exit:
 992         mutex_unlock(&trf->lock);
 993         return IRQ_HANDLED;
 994 }
 995
 996 static void trf7970a_issue_eof(struct trf7970a *trf)
 997 {
 998         int ret;
 999
1000         dev_dbg(trf->dev, "Issuing EOF\n");
1001
1002         ret = trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
1003         if (ret)
1004                 trf7970a_send_err_upstream(trf, ret);
1005
1006         ret = trf7970a_cmd(trf, TRF7970A_CMD_EOF);
1007         if (ret)
1008                 trf7970a_send_err_upstream(trf, ret);
1009
1010         trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
1011
1012         dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n",
1013                         trf->timeout, trf->state);
1014
1015         schedule_delayed_work(&trf->timeout_work,
1016                         msecs_to_jiffies(trf->timeout));
1017 }
1018
1019 static void trf7970a_timeout_work_handler(struct work_struct *work)
1020 {
1021         struct trf7970a *trf = container_of(work, struct trf7970a,
1022                         timeout_work.work);
1023
1024         dev_dbg(trf->dev, "Timeout - state: %d, ignore_timeout: %d\n",
1025                         trf->state, trf->ignore_timeout);
1026
1027         mutex_lock(&trf->lock);
1028
1029         if (trf->ignore_timeout)
1030                 trf->ignore_timeout = false;
1031         else if (trf->state == TRF7970A_ST_WAIT_FOR_RX_DATA_CONT)
1032                 trf7970a_drain_fifo(trf, TRF7970A_IRQ_STATUS_SRX);
1033         else if (trf->state == TRF7970A_ST_WAIT_TO_ISSUE_EOF)
1034                 trf7970a_issue_eof(trf);
1035         else
1036                 trf7970a_send_err_upstream(trf, -ETIMEDOUT);
1037
1038         mutex_unlock(&trf->lock);
1039 }
1040
1041 static int trf7970a_init(struct trf7970a *trf)
1042 {
1043         int ret;
1044
1045         dev_dbg(trf->dev, "Initializing device - state: %d\n", trf->state);
1046
1047         ret = trf7970a_cmd(trf, TRF7970A_CMD_SOFT_INIT);
1048         if (ret)
1049                 goto err_out;
1050
1051         ret = trf7970a_cmd(trf, TRF7970A_CMD_IDLE);
1052         if (ret)
1053                 goto err_out;
1054
1055         ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1056                         trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1057         if (ret)
1058                 goto err_out;
1059
1060         ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1061         if (ret)
1062                 goto err_out;
1063
1064         usleep_range(1000, 2000);
1065
1066         trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1067
1068         ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1069                         trf->modulator_sys_clk_ctrl);
1070         if (ret)
1071                 goto err_out;
1072
1073         ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS,
1074                         TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 |
1075                         TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32);
1076         if (ret)
1077                 goto err_out;
1078
1079         ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1, 0);
1080         if (ret)
1081                 goto err_out;
1082
1083         trf->special_fcn_reg1 = 0;
1084
1085         trf->iso_ctrl = 0xff;
1086         return 0;
1087
1088 err_out:
1089         dev_dbg(trf->dev, "Couldn't init device: %d\n", ret);
1090         return ret;
1091 }
1092
1093 static void trf7970a_switch_rf_off(struct trf7970a *trf)
1094 {
1095         if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1096                         (trf->state == TRF7970A_ST_RF_OFF))
1097                 return;
1098
1099         dev_dbg(trf->dev, "Switching rf off\n");
1100
1101         trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1102
1103         trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, trf->chip_status_ctrl);
1104
1105         trf->aborting = false;
1106         trf->state = TRF7970A_ST_RF_OFF;
1107
1108         pm_runtime_mark_last_busy(trf->dev);
1109         pm_runtime_put_autosuspend(trf->dev);
1110 }
1111
1112 static int trf7970a_switch_rf_on(struct trf7970a *trf)
1113 {
1114         int ret;
1115
1116         dev_dbg(trf->dev, "Switching rf on\n");
1117
1118         pm_runtime_get_sync(trf->dev);
1119
1120         if (trf->state != TRF7970A_ST_RF_OFF) { /* Power on, RF off */
1121                 dev_err(trf->dev, "%s - Incorrect state: %d\n", __func__,
1122                                 trf->state);
1123                 return -EINVAL;
1124         }
1125
1126         ret = trf7970a_init(trf);
1127         if (ret) {
1128                 dev_err(trf->dev, "%s - Can't initialize: %d\n", __func__, ret);
1129                 return ret;
1130         }
1131
1132         trf->state = TRF7970A_ST_IDLE;
1133
1134         return 0;
1135 }
1136
1137 static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on)
1138 {
1139         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1140         int ret = 0;
1141
1142         dev_dbg(trf->dev, "Switching RF - state: %d, on: %d\n", trf->state, on);
1143
1144         mutex_lock(&trf->lock);
1145
1146         if (on) {
1147                 switch (trf->state) {
1148                 case TRF7970A_ST_PWR_OFF:
1149                 case TRF7970A_ST_RF_OFF:
1150                         ret = trf7970a_switch_rf_on(trf);
1151                         break;
1152                 case TRF7970A_ST_IDLE:
1153                 case TRF7970A_ST_IDLE_RX_BLOCKED:
1154                         break;
1155                 default:
1156                         dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1157                                         __func__, trf->state, on);
1158                         trf7970a_switch_rf_off(trf);
1159                         ret = -EINVAL;
1160                 }
1161         } else {
1162                 switch (trf->state) {
1163                 case TRF7970A_ST_PWR_OFF:
1164                 case TRF7970A_ST_RF_OFF:
1165                         break;
1166                 default:
1167                         dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1168                                         __func__, trf->state, on);
1169                         ret = -EINVAL;
1170                         /* FALLTHROUGH */
1171                 case TRF7970A_ST_IDLE:
1172                 case TRF7970A_ST_IDLE_RX_BLOCKED:
1173                 case TRF7970A_ST_WAIT_FOR_RX_DATA:
1174                 case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1175                         trf7970a_switch_rf_off(trf);
1176                 }
1177         }
1178
1179         mutex_unlock(&trf->lock);
1180         return ret;
1181 }
1182
1183 static int trf7970a_in_config_rf_tech(struct trf7970a *trf, int tech)
1184 {
1185         int ret = 0;
1186
1187         dev_dbg(trf->dev, "rf technology: %d\n", tech);
1188
1189         switch (tech) {
1190         case NFC_DIGITAL_RF_TECH_106A:
1191                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443A_106;
1192                 trf->modulator_sys_clk_ctrl =
1193                         (trf->modulator_sys_clk_ctrl & 0xf8) |
1194                         TRF7970A_MODULATOR_DEPTH_OOK;
1195                 trf->guard_time = TRF7970A_GUARD_TIME_NFCA;
1196                 break;
1197         case NFC_DIGITAL_RF_TECH_106B:
1198                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443B_106;
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_NFCB;
1203                 break;
1204         case NFC_DIGITAL_RF_TECH_212F:
1205                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_212;
1206                 trf->modulator_sys_clk_ctrl =
1207                         (trf->modulator_sys_clk_ctrl & 0xf8) |
1208                         TRF7970A_MODULATOR_DEPTH_ASK10;
1209                 trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1210                 break;
1211         case NFC_DIGITAL_RF_TECH_424F:
1212                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_424;
1213                 trf->modulator_sys_clk_ctrl =
1214                         (trf->modulator_sys_clk_ctrl & 0xf8) |
1215                         TRF7970A_MODULATOR_DEPTH_ASK10;
1216                 trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1217                 break;
1218         case NFC_DIGITAL_RF_TECH_ISO15693:
1219                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1220                 trf->modulator_sys_clk_ctrl =
1221                         (trf->modulator_sys_clk_ctrl & 0xf8) |
1222                         TRF7970A_MODULATOR_DEPTH_OOK;
1223                 trf->guard_time = TRF7970A_GUARD_TIME_15693;
1224                 break;
1225         default:
1226                 dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1227                 return -EINVAL;
1228         }
1229
1230         trf->technology = tech;
1231
1232         /* If in initiator mode and not changing the RF tech due to a
1233          * PSL sequence (indicated by 'trf->iso_ctrl == 0xff' from
1234          * trf7970a_init()), clear the NFC Target Detection Level register
1235          * due to erratum.
1236          */
1237         if (trf->iso_ctrl == 0xff)
1238                 ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1239
1240         return ret;
1241 }
1242
1243 static int trf7970a_is_rf_field(struct trf7970a *trf, bool *is_rf_field)
1244 {
1245         int ret;
1246         u8 rssi;
1247
1248         ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1249                         trf->chip_status_ctrl | TRF7970A_CHIP_STATUS_REC_ON);
1250         if (ret)
1251                 return ret;
1252
1253         ret = trf7970a_cmd(trf, TRF7970A_CMD_TEST_EXT_RF);
1254         if (ret)
1255                 return ret;
1256
1257         usleep_range(50, 60);
1258
1259         ret = trf7970a_read(trf, TRF7970A_RSSI_OSC_STATUS, &rssi);
1260         if (ret)
1261                 return ret;
1262
1263         ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1264                         trf->chip_status_ctrl);
1265         if (ret)
1266                 return ret;
1267
1268         if (rssi & TRF7970A_RSSI_OSC_STATUS_RSSI_MASK)
1269                 *is_rf_field = true;
1270         else
1271                 *is_rf_field = false;
1272
1273         return 0;
1274 }
1275
1276 static int trf7970a_in_config_framing(struct trf7970a *trf, int framing)
1277 {
1278         u8 iso_ctrl = trf->iso_ctrl_tech;
1279         bool is_rf_field = false;
1280         int ret;
1281
1282         dev_dbg(trf->dev, "framing: %d\n", framing);
1283
1284         switch (framing) {
1285         case NFC_DIGITAL_FRAMING_NFCA_SHORT:
1286         case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1287                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1288                 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1289                 break;
1290         case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1291         case NFC_DIGITAL_FRAMING_NFCA_T4T:
1292         case NFC_DIGITAL_FRAMING_NFCB:
1293         case NFC_DIGITAL_FRAMING_NFCB_T4T:
1294         case NFC_DIGITAL_FRAMING_NFCF:
1295         case NFC_DIGITAL_FRAMING_NFCF_T3T:
1296         case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY:
1297         case NFC_DIGITAL_FRAMING_ISO15693_T5T:
1298         case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1299         case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1300                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1301                 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1302                 break;
1303         case NFC_DIGITAL_FRAMING_NFCA_T2T:
1304                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1305                 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1306                 break;
1307         default:
1308                 dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1309                 return -EINVAL;
1310         }
1311
1312         trf->framing = framing;
1313
1314         if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1315                 ret = trf7970a_is_rf_field(trf, &is_rf_field);
1316                 if (ret)
1317                         return ret;
1318
1319                 if (is_rf_field)
1320                         return -EBUSY;
1321         }
1322
1323         if (iso_ctrl != trf->iso_ctrl) {
1324                 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1325                 if (ret)
1326                         return ret;
1327
1328                 trf->iso_ctrl = iso_ctrl;
1329
1330                 ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1331                                 trf->modulator_sys_clk_ctrl);
1332                 if (ret)
1333                         return ret;
1334         }
1335
1336         if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1337                 ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1338                                 trf->chip_status_ctrl |
1339                                         TRF7970A_CHIP_STATUS_RF_ON);
1340                 if (ret)
1341                         return ret;
1342
1343                 trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1344
1345                 usleep_range(trf->guard_time, trf->guard_time + 1000);
1346         }
1347
1348         return 0;
1349 }
1350
1351 static int trf7970a_in_configure_hw(struct nfc_digital_dev *ddev, int type,
1352                 int param)
1353 {
1354         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1355         int ret;
1356
1357         dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1358
1359         mutex_lock(&trf->lock);
1360
1361         trf->is_initiator = true;
1362
1363         if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1364                         (trf->state == TRF7970A_ST_RF_OFF)) {
1365                 ret = trf7970a_switch_rf_on(trf);
1366                 if (ret)
1367                         goto err_unlock;
1368         }
1369
1370         switch (type) {
1371         case NFC_DIGITAL_CONFIG_RF_TECH:
1372                 ret = trf7970a_in_config_rf_tech(trf, param);
1373                 break;
1374         case NFC_DIGITAL_CONFIG_FRAMING:
1375                 ret = trf7970a_in_config_framing(trf, param);
1376                 break;
1377         default:
1378                 dev_dbg(trf->dev, "Unknown type: %d\n", type);
1379                 ret = -EINVAL;
1380         }
1381
1382 err_unlock:
1383         mutex_unlock(&trf->lock);
1384         return ret;
1385 }
1386
1387 static int trf7970a_is_iso15693_write_or_lock(u8 cmd)
1388 {
1389         switch (cmd) {
1390         case ISO15693_CMD_WRITE_SINGLE_BLOCK:
1391         case ISO15693_CMD_LOCK_BLOCK:
1392         case ISO15693_CMD_WRITE_MULTIPLE_BLOCK:
1393         case ISO15693_CMD_WRITE_AFI:
1394         case ISO15693_CMD_LOCK_AFI:
1395         case ISO15693_CMD_WRITE_DSFID:
1396         case ISO15693_CMD_LOCK_DSFID:
1397                 return 1;
1398                 break;
1399         default:
1400                 return 0;
1401         }
1402 }
1403
1404 static int trf7970a_per_cmd_config(struct trf7970a *trf, struct sk_buff *skb)
1405 {
1406         u8 *req = skb->data;
1407         u8 special_fcn_reg1, iso_ctrl;
1408         int ret;
1409
1410         trf->issue_eof = false;
1411
1412         /* When issuing Type 2 read command, make sure the '4_bit_RX' bit in
1413          * special functions register 1 is cleared; otherwise, its a write or
1414          * sector select command and '4_bit_RX' must be set.
1415          *
1416          * When issuing an ISO 15693 command, inspect the flags byte to see
1417          * what speed to use.  Also, remember if the OPTION flag is set on
1418          * a Type 5 write or lock command so the driver will know that it
1419          * has to send an EOF in order to get a response.
1420          */
1421         if ((trf->technology == NFC_DIGITAL_RF_TECH_106A) &&
1422                         (trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T)) {
1423                 if (req[0] == NFC_T2T_CMD_READ)
1424                         special_fcn_reg1 = 0;
1425                 else
1426                         special_fcn_reg1 = TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX;
1427
1428                 if (special_fcn_reg1 != trf->special_fcn_reg1) {
1429                         ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1,
1430                                         special_fcn_reg1);
1431                         if (ret)
1432                                 return ret;
1433
1434                         trf->special_fcn_reg1 = special_fcn_reg1;
1435                 }
1436         } else if (trf->technology == NFC_DIGITAL_RF_TECH_ISO15693) {
1437                 iso_ctrl = trf->iso_ctrl & ~TRF7970A_ISO_CTRL_RFID_SPEED_MASK;
1438
1439                 switch (req[0] & ISO15693_REQ_FLAG_SPEED_MASK) {
1440                 case 0x00:
1441                         iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_662;
1442                         break;
1443                 case ISO15693_REQ_FLAG_SUB_CARRIER:
1444                         iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a;
1445                         break;
1446                 case ISO15693_REQ_FLAG_DATA_RATE:
1447                         iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1448                         break;
1449                 case (ISO15693_REQ_FLAG_SUB_CARRIER |
1450                                 ISO15693_REQ_FLAG_DATA_RATE):
1451                         iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669;
1452                         break;
1453                 }
1454
1455                 if (iso_ctrl != trf->iso_ctrl) {
1456                         ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1457                         if (ret)
1458                                 return ret;
1459
1460                         trf->iso_ctrl = iso_ctrl;
1461                 }
1462
1463                 if (trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) {
1464                         if (trf7970a_is_iso15693_write_or_lock(req[1]) &&
1465                                         (req[0] & ISO15693_REQ_FLAG_OPTION))
1466                                 trf->issue_eof = true;
1467                         else if ((trf->quirks &
1468                                         TRF7970A_QUIRK_T5T_RMB_EXTRA_BYTE) &&
1469                                  (req[1] == ISO15693_CMD_READ_MULTIPLE_BLOCK))
1470                                 trf->adjust_resp_len = true;
1471                 }
1472         }
1473
1474         return 0;
1475 }
1476
1477 static int trf7970a_send_cmd(struct nfc_digital_dev *ddev,
1478                 struct sk_buff *skb, u16 timeout,
1479                 nfc_digital_cmd_complete_t cb, void *arg)
1480 {
1481         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1482         u8 prefix[5];
1483         unsigned int len;
1484         int ret;
1485         u8 status;
1486
1487         dev_dbg(trf->dev, "New request - state: %d, timeout: %d ms, len: %d\n",
1488                         trf->state, timeout, skb->len);
1489
1490         if (skb->len > TRF7970A_TX_MAX)
1491                 return -EINVAL;
1492
1493         mutex_lock(&trf->lock);
1494
1495         if ((trf->state != TRF7970A_ST_IDLE) &&
1496                         (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1497                 dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1498                                 trf->state);
1499                 ret = -EIO;
1500                 goto out_err;
1501         }
1502
1503         if (trf->aborting) {
1504                 dev_dbg(trf->dev, "Abort process complete\n");
1505                 trf->aborting = false;
1506                 ret = -ECANCELED;
1507                 goto out_err;
1508         }
1509
1510         if (timeout) {
1511                 trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1512                                 GFP_KERNEL);
1513                 if (!trf->rx_skb) {
1514                         dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1515                         ret = -ENOMEM;
1516                         goto out_err;
1517                 }
1518         }
1519
1520         if (trf->state == TRF7970A_ST_IDLE_RX_BLOCKED) {
1521                 ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1522                 if (ret)
1523                         goto out_err;
1524
1525                 trf->state = TRF7970A_ST_IDLE;
1526         }
1527
1528         if (trf->is_initiator) {
1529                 ret = trf7970a_per_cmd_config(trf, skb);
1530                 if (ret)
1531                         goto out_err;
1532         }
1533
1534         trf->ddev = ddev;
1535         trf->tx_skb = skb;
1536         trf->cb = cb;
1537         trf->cb_arg = arg;
1538         trf->timeout = timeout;
1539         trf->ignore_timeout = false;
1540
1541         len = skb->len;
1542
1543         /* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
1544          * on what the current framing is, the address of the TX length byte 1
1545          * register (0x1d), and the 2 byte length of the data to be transmitted.
1546          * That totals 5 bytes.
1547          */
1548         prefix[0] = TRF7970A_CMD_BIT_CTRL |
1549                         TRF7970A_CMD_BIT_OPCODE(TRF7970A_CMD_FIFO_RESET);
1550         prefix[1] = TRF7970A_CMD_BIT_CTRL |
1551                         TRF7970A_CMD_BIT_OPCODE(trf->tx_cmd);
1552         prefix[2] = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_TX_LENGTH_BYTE1;
1553
1554         if (trf->framing == NFC_DIGITAL_FRAMING_NFCA_SHORT) {
1555                 prefix[3] = 0x00;
1556                 prefix[4] = 0x0f; /* 7 bits */
1557         } else {
1558                 prefix[3] = (len & 0xf00) >> 4;
1559                 prefix[3] |= ((len & 0xf0) >> 4);
1560                 prefix[4] = ((len & 0x0f) << 4);
1561         }
1562
1563         len = min_t(int, skb->len, TRF7970A_FIFO_SIZE);
1564
1565         /* Clear possible spurious interrupt */
1566         ret = trf7970a_read_irqstatus(trf, &status);
1567         if (ret)
1568                 goto out_err;
1569
1570         ret = trf7970a_transmit(trf, skb, len, prefix, sizeof(prefix));
1571         if (ret) {
1572                 kfree_skb(trf->rx_skb);
1573                 trf->rx_skb = NULL;
1574         }
1575
1576 out_err:
1577         mutex_unlock(&trf->lock);
1578         return ret;
1579 }
1580
1581 static int trf7970a_tg_config_rf_tech(struct trf7970a *trf, int tech)
1582 {
1583         int ret = 0;
1584
1585         dev_dbg(trf->dev, "rf technology: %d\n", tech);
1586
1587         switch (tech) {
1588         case NFC_DIGITAL_RF_TECH_106A:
1589                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1590                         TRF7970A_ISO_CTRL_NFC_CE |
1591                         TRF7970A_ISO_CTRL_NFC_CE_14443A;
1592                 trf->modulator_sys_clk_ctrl =
1593                         (trf->modulator_sys_clk_ctrl & 0xf8) |
1594                         TRF7970A_MODULATOR_DEPTH_OOK;
1595                 break;
1596         case NFC_DIGITAL_RF_TECH_212F:
1597                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1598                         TRF7970A_ISO_CTRL_NFC_NFCF_212;
1599                 trf->modulator_sys_clk_ctrl =
1600                         (trf->modulator_sys_clk_ctrl & 0xf8) |
1601                         TRF7970A_MODULATOR_DEPTH_ASK10;
1602                 break;
1603         case NFC_DIGITAL_RF_TECH_424F:
1604                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1605                         TRF7970A_ISO_CTRL_NFC_NFCF_424;
1606                 trf->modulator_sys_clk_ctrl =
1607                         (trf->modulator_sys_clk_ctrl & 0xf8) |
1608                         TRF7970A_MODULATOR_DEPTH_ASK10;
1609                 break;
1610         default:
1611                 dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1612                 return -EINVAL;
1613         }
1614
1615         trf->technology = tech;
1616
1617         /* Normally we write the ISO_CTRL register in
1618          * trf7970a_tg_config_framing() because the framing can change
1619          * the value written.  However, when sending a PSL RES,
1620          * digital_tg_send_psl_res_complete() doesn't call
1621          * trf7970a_tg_config_framing() so we must write the register
1622          * here.
1623          */
1624         if ((trf->framing == NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED) &&
1625                         (trf->iso_ctrl_tech != trf->iso_ctrl)) {
1626                 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
1627                                 trf->iso_ctrl_tech);
1628
1629                 trf->iso_ctrl = trf->iso_ctrl_tech;
1630         }
1631
1632         return ret;
1633 }
1634
1635 /* Since this is a target routine, several of the framing calls are
1636  * made between receiving the request and sending the response so they
1637  * should take effect until after the response is sent.  This is accomplished
1638  * by skipping the ISO_CTRL register write here and doing it in the interrupt
1639  * handler.
1640  */
1641 static int trf7970a_tg_config_framing(struct trf7970a *trf, int framing)
1642 {
1643         u8 iso_ctrl = trf->iso_ctrl_tech;
1644         int ret;
1645
1646         dev_dbg(trf->dev, "framing: %d\n", framing);
1647
1648         switch (framing) {
1649         case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1650                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1651                 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1652                 break;
1653         case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1654         case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1655         case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
1656                 /* These ones are applied in the interrupt handler */
1657                 iso_ctrl = trf->iso_ctrl; /* Don't write to ISO_CTRL yet */
1658                 break;
1659         case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1660                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1661                 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1662                 break;
1663         case NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED:
1664                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1665                 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1666                 break;
1667         default:
1668                 dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1669                 return -EINVAL;
1670         }
1671
1672         trf->framing = framing;
1673
1674         if (iso_ctrl != trf->iso_ctrl) {
1675                 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1676                 if (ret)
1677                         return ret;
1678
1679                 trf->iso_ctrl = iso_ctrl;
1680
1681                 ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1682                                 trf->modulator_sys_clk_ctrl);
1683                 if (ret)
1684                         return ret;
1685         }
1686
1687         if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1688                 ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1689                                 trf->chip_status_ctrl |
1690                                         TRF7970A_CHIP_STATUS_RF_ON);
1691                 if (ret)
1692                         return ret;
1693
1694                 trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1695         }
1696
1697         return 0;
1698 }
1699
1700 static int trf7970a_tg_configure_hw(struct nfc_digital_dev *ddev, int type,
1701                 int param)
1702 {
1703         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1704         int ret;
1705
1706         dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1707
1708         mutex_lock(&trf->lock);
1709
1710         trf->is_initiator = false;
1711
1712         if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1713                         (trf->state == TRF7970A_ST_RF_OFF)) {
1714                 ret = trf7970a_switch_rf_on(trf);
1715                 if (ret)
1716                         goto err_unlock;
1717         }
1718
1719         switch (type) {
1720         case NFC_DIGITAL_CONFIG_RF_TECH:
1721                 ret = trf7970a_tg_config_rf_tech(trf, param);
1722                 break;
1723         case NFC_DIGITAL_CONFIG_FRAMING:
1724                 ret = trf7970a_tg_config_framing(trf, param);
1725                 break;
1726         default:
1727                 dev_dbg(trf->dev, "Unknown type: %d\n", type);
1728                 ret = -EINVAL;
1729         }
1730
1731 err_unlock:
1732         mutex_unlock(&trf->lock);
1733         return ret;
1734 }
1735
1736 static int _trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1737                 nfc_digital_cmd_complete_t cb, void *arg, bool mode_detect)
1738 {
1739         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1740         int ret;
1741
1742         mutex_lock(&trf->lock);
1743
1744         if ((trf->state != TRF7970A_ST_IDLE) &&
1745                         (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1746                 dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1747                                 trf->state);
1748                 ret = -EIO;
1749                 goto out_err;
1750         }
1751
1752         if (trf->aborting) {
1753                 dev_dbg(trf->dev, "Abort process complete\n");
1754                 trf->aborting = false;
1755                 ret = -ECANCELED;
1756                 goto out_err;
1757         }
1758
1759         trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1760                         GFP_KERNEL);
1761         if (!trf->rx_skb) {
1762                 dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1763                 ret = -ENOMEM;
1764                 goto out_err;
1765         }
1766
1767         ret = trf7970a_write(trf, TRF7970A_RX_SPECIAL_SETTINGS,
1768                         TRF7970A_RX_SPECIAL_SETTINGS_HBT |
1769                         TRF7970A_RX_SPECIAL_SETTINGS_M848 |
1770                         TRF7970A_RX_SPECIAL_SETTINGS_C424 |
1771                         TRF7970A_RX_SPECIAL_SETTINGS_C212);
1772         if (ret)
1773                 goto out_err;
1774
1775         ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1776                         trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1777         if (ret)
1778                 goto out_err;
1779
1780         ret = trf7970a_write(trf, TRF7970A_NFC_LOW_FIELD_LEVEL,
1781                         TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(0x3));
1782         if (ret)
1783                 goto out_err;
1784
1785         ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL,
1786                         TRF7970A_NFC_TARGET_LEVEL_RFDET(0x7));
1787         if (ret)
1788                 goto out_err;
1789
1790         trf->ddev = ddev;
1791         trf->cb = cb;
1792         trf->cb_arg = arg;
1793         trf->timeout = timeout;
1794         trf->ignore_timeout = false;
1795
1796         ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1797         if (ret)
1798                 goto out_err;
1799
1800         trf->state = mode_detect ? TRF7970A_ST_LISTENING_MD :
1801                                    TRF7970A_ST_LISTENING;
1802
1803         schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
1804
1805 out_err:
1806         mutex_unlock(&trf->lock);
1807         return ret;
1808 }
1809
1810 static int trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1811                 nfc_digital_cmd_complete_t cb, void *arg)
1812 {
1813         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1814
1815         dev_dbg(trf->dev, "Listen - state: %d, timeout: %d ms\n",
1816                         trf->state, timeout);
1817
1818         return _trf7970a_tg_listen(ddev, timeout, cb, arg, false);
1819 }
1820
1821 static int trf7970a_tg_listen_md(struct nfc_digital_dev *ddev,
1822                 u16 timeout, nfc_digital_cmd_complete_t cb, void *arg)
1823 {
1824         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1825         int ret;
1826
1827         dev_dbg(trf->dev, "Listen MD - state: %d, timeout: %d ms\n",
1828                         trf->state, timeout);
1829
1830         ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
1831                         NFC_DIGITAL_RF_TECH_106A);
1832         if (ret)
1833                 return ret;
1834
1835         ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1836                         NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
1837         if (ret)
1838                 return ret;
1839
1840         return _trf7970a_tg_listen(ddev, timeout, cb, arg, true);
1841 }
1842
1843 static int trf7970a_tg_get_rf_tech(struct nfc_digital_dev *ddev, u8 *rf_tech)
1844 {
1845         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1846
1847         dev_dbg(trf->dev, "Get RF Tech - state: %d, rf_tech: %d\n",
1848                         trf->state, trf->md_rf_tech);
1849
1850         *rf_tech = trf->md_rf_tech;
1851
1852         return 0;
1853 }
1854
1855 static void trf7970a_abort_cmd(struct nfc_digital_dev *ddev)
1856 {
1857         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1858
1859         dev_dbg(trf->dev, "Abort process initiated\n");
1860
1861         mutex_lock(&trf->lock);
1862
1863         switch (trf->state) {
1864         case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1865         case TRF7970A_ST_WAIT_FOR_RX_DATA:
1866         case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1867         case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1868                 trf->aborting = true;
1869                 break;
1870         case TRF7970A_ST_LISTENING:
1871                 trf->ignore_timeout = !cancel_delayed_work(&trf->timeout_work);
1872                 trf7970a_send_err_upstream(trf, -ECANCELED);
1873                 dev_dbg(trf->dev, "Abort process complete\n");
1874                 break;
1875         default:
1876                 break;
1877         }
1878
1879         mutex_unlock(&trf->lock);
1880 }
1881
1882 static struct nfc_digital_ops trf7970a_nfc_ops = {
1883         .in_configure_hw        = trf7970a_in_configure_hw,
1884         .in_send_cmd            = trf7970a_send_cmd,
1885         .tg_configure_hw        = trf7970a_tg_configure_hw,
1886         .tg_send_cmd            = trf7970a_send_cmd,
1887         .tg_listen              = trf7970a_tg_listen,
1888         .tg_listen_md           = trf7970a_tg_listen_md,
1889         .tg_get_rf_tech         = trf7970a_tg_get_rf_tech,
1890         .switch_rf              = trf7970a_switch_rf,
1891         .abort_cmd              = trf7970a_abort_cmd,
1892 };
1893
1894 static int trf7970a_power_up(struct trf7970a *trf)
1895 {
1896         int ret;
1897
1898         dev_dbg(trf->dev, "Powering up - state: %d\n", trf->state);
1899
1900         if (trf->state != TRF7970A_ST_PWR_OFF)
1901                 return 0;
1902
1903         ret = regulator_enable(trf->regulator);
1904         if (ret) {
1905                 dev_err(trf->dev, "%s - Can't enable VIN: %d\n", __func__, ret);
1906                 return ret;
1907         }
1908
1909         usleep_range(5000, 6000);
1910
1911         if (!(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW)) {
1912                 if (gpio_is_valid(trf->en2_gpio)) {
1913                         gpio_set_value(trf->en2_gpio, 1);
1914                         usleep_range(1000, 2000);
1915                 }
1916         }
1917
1918         gpio_set_value(trf->en_gpio, 1);
1919
1920         usleep_range(20000, 21000);
1921
1922         trf->state = TRF7970A_ST_RF_OFF;
1923
1924         return 0;
1925 }
1926
1927 static int trf7970a_power_down(struct trf7970a *trf)
1928 {
1929         int ret;
1930
1931         dev_dbg(trf->dev, "Powering down - state: %d\n", trf->state);
1932
1933         if (trf->state == TRF7970A_ST_PWR_OFF)
1934                 return 0;
1935
1936         if (trf->state != TRF7970A_ST_RF_OFF) {
1937                 dev_dbg(trf->dev, "Can't power down - not RF_OFF state (%d)\n",
1938                                 trf->state);
1939                 return -EBUSY;
1940         }
1941
1942         gpio_set_value(trf->en_gpio, 0);
1943         if (gpio_is_valid(trf->en2_gpio))
1944                 gpio_set_value(trf->en2_gpio, 0);
1945
1946         ret = regulator_disable(trf->regulator);
1947         if (ret)
1948                 dev_err(trf->dev, "%s - Can't disable VIN: %d\n", __func__,
1949                                 ret);
1950
1951         trf->state = TRF7970A_ST_PWR_OFF;
1952
1953         return ret;
1954 }
1955
1956 static int trf7970a_startup(struct trf7970a *trf)
1957 {
1958         int ret;
1959
1960         ret = trf7970a_power_up(trf);
1961         if (ret)
1962                 return ret;
1963
1964         pm_runtime_set_active(trf->dev);
1965         pm_runtime_enable(trf->dev);
1966         pm_runtime_mark_last_busy(trf->dev);
1967
1968         return 0;
1969 }
1970
1971 static void trf7970a_shutdown(struct trf7970a *trf)
1972 {
1973         switch (trf->state) {
1974         case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1975         case TRF7970A_ST_WAIT_FOR_RX_DATA:
1976         case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1977         case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1978         case TRF7970A_ST_LISTENING:
1979                 trf7970a_send_err_upstream(trf, -ECANCELED);
1980                 /* FALLTHROUGH */
1981         case TRF7970A_ST_IDLE:
1982         case TRF7970A_ST_IDLE_RX_BLOCKED:
1983                 trf7970a_switch_rf_off(trf);
1984                 break;
1985         default:
1986                 break;
1987         }
1988
1989         pm_runtime_disable(trf->dev);
1990         pm_runtime_set_suspended(trf->dev);
1991
1992         trf7970a_power_down(trf);
1993 }
1994
1995 static int trf7970a_get_autosuspend_delay(struct device_node *np)
1996 {
1997         int autosuspend_delay, ret;
1998
1999         ret = of_property_read_u32(np, "autosuspend-delay", &autosuspend_delay);
2000         if (ret)
2001                 autosuspend_delay = TRF7970A_AUTOSUSPEND_DELAY;
2002
2003         return autosuspend_delay;
2004 }
2005
2006 static int trf7970a_get_vin_voltage_override(struct device_node *np,
2007                 u32 *vin_uvolts)
2008 {
2009         return of_property_read_u32(np, "vin-voltage-override", vin_uvolts);
2010 }
2011
2012 static int trf7970a_probe(struct spi_device *spi)
2013 {
2014         struct device_node *np = spi->dev.of_node;
2015         struct trf7970a *trf;
2016         int uvolts, autosuspend_delay, ret;
2017         u32 clk_freq = TRF7970A_13MHZ_CLOCK_FREQUENCY;
2018
2019         if (!np) {
2020                 dev_err(&spi->dev, "No Device Tree entry\n");
2021                 return -EINVAL;
2022         }
2023
2024         trf = devm_kzalloc(&spi->dev, sizeof(*trf), GFP_KERNEL);
2025         if (!trf)
2026                 return -ENOMEM;
2027
2028         trf->state = TRF7970A_ST_PWR_OFF;
2029         trf->dev = &spi->dev;
2030         trf->spi = spi;
2031
2032         spi->mode = SPI_MODE_1;
2033         spi->bits_per_word = 8;
2034
2035         ret = spi_setup(spi);
2036         if (ret < 0) {
2037                 dev_err(trf->dev, "Can't set up SPI Communication\n");
2038                 return ret;
2039         }
2040
2041         if (of_property_read_bool(np, "t5t-rmb-extra-byte-quirk"))
2042                 trf->quirks |= TRF7970A_QUIRK_T5T_RMB_EXTRA_BYTE;
2043
2044         if (of_property_read_bool(np, "irq-status-read-quirk"))
2045                 trf->quirks |= TRF7970A_QUIRK_IRQ_STATUS_READ;
2046
2047         /* There are two enable pins - both must be present */
2048         trf->en_gpio = of_get_named_gpio(np, "ti,enable-gpios", 0);
2049         if (!gpio_is_valid(trf->en_gpio)) {
2050                 dev_err(trf->dev, "No EN GPIO property\n");
2051                 return trf->en_gpio;
2052         }
2053
2054         ret = devm_gpio_request_one(trf->dev, trf->en_gpio,
2055                         GPIOF_DIR_OUT | GPIOF_INIT_LOW, "trf7970a EN");
2056         if (ret) {
2057                 dev_err(trf->dev, "Can't request EN GPIO: %d\n", ret);
2058                 return ret;
2059         }
2060
2061         trf->en2_gpio = of_get_named_gpio(np, "ti,enable-gpios", 1);
2062         if (!gpio_is_valid(trf->en2_gpio)) {
2063                 dev_info(trf->dev, "No EN2 GPIO property\n");
2064         } else {
2065                 ret = devm_gpio_request_one(trf->dev, trf->en2_gpio,
2066                                 GPIOF_DIR_OUT | GPIOF_INIT_LOW, "trf7970a EN2");
2067                 if (ret) {
2068                         dev_err(trf->dev, "Can't request EN2 GPIO: %d\n", ret);
2069                         return ret;
2070                 }
2071         }
2072
2073         of_property_read_u32(np, "clock-frequency", &clk_freq);
2074         if ((clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY) ||
2075                 (clk_freq != TRF7970A_13MHZ_CLOCK_FREQUENCY)) {
2076                 dev_err(trf->dev,
2077                         "clock-frequency (%u Hz) unsupported\n",
2078                         clk_freq);
2079                 return -EINVAL;
2080         }
2081
2082         if (of_property_read_bool(np, "en2-rf-quirk"))
2083                 trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;
2084
2085         ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL,
2086                         trf7970a_irq, IRQF_TRIGGER_RISING | IRQF_ONESHOT,
2087                         "trf7970a", trf);
2088         if (ret) {
2089                 dev_err(trf->dev, "Can't request IRQ#%d: %d\n", spi->irq, ret);
2090                 return ret;
2091         }
2092
2093         mutex_init(&trf->lock);
2094         INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
2095
2096         trf->regulator = devm_regulator_get(&spi->dev, "vin");
2097         if (IS_ERR(trf->regulator)) {
2098                 ret = PTR_ERR(trf->regulator);
2099                 dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret);
2100                 goto err_destroy_lock;
2101         }
2102
2103         ret = regulator_enable(trf->regulator);
2104         if (ret) {
2105                 dev_err(trf->dev, "Can't enable VIN: %d\n", ret);
2106                 goto err_destroy_lock;
2107         }
2108
2109         ret = trf7970a_get_vin_voltage_override(np, &uvolts);
2110         if (ret)
2111                 uvolts = regulator_get_voltage(trf->regulator);
2112
2113         if (uvolts > 4000000)
2114                 trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;
2115
2116         trf->regulator = devm_regulator_get(&spi->dev, "vdd-io");
2117         if (IS_ERR(trf->regulator)) {
2118                 ret = PTR_ERR(trf->regulator);
2119                 dev_err(trf->dev, "Can't get VDD_IO regulator: %d\n", ret);
2120                 goto err_destroy_lock;
2121         }
2122
2123         ret = regulator_enable(trf->regulator);
2124         if (ret) {
2125                 dev_err(trf->dev, "Can't enable VDD_IO: %d\n", ret);
2126                 goto err_destroy_lock;
2127         }
2128
2129         if (regulator_get_voltage(trf->regulator) == 1800000) {
2130                 trf->io_ctrl = TRF7970A_REG_IO_CTRL_IO_LOW;
2131                 dev_dbg(trf->dev, "trf7970a config vdd_io to 1.8V\n");
2132         }
2133
2134         trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,
2135                         TRF7970A_SUPPORTED_PROTOCOLS,
2136                         NFC_DIGITAL_DRV_CAPS_IN_CRC |
2137                                 NFC_DIGITAL_DRV_CAPS_TG_CRC, 0, 0);
2138         if (!trf->ddev) {
2139                 dev_err(trf->dev, "Can't allocate NFC digital device\n");
2140                 ret = -ENOMEM;
2141                 goto err_disable_regulator;
2142         }
2143
2144         nfc_digital_set_parent_dev(trf->ddev, trf->dev);
2145         nfc_digital_set_drvdata(trf->ddev, trf);
2146         spi_set_drvdata(spi, trf);
2147
2148         autosuspend_delay = trf7970a_get_autosuspend_delay(np);
2149
2150         pm_runtime_set_autosuspend_delay(trf->dev, autosuspend_delay);
2151         pm_runtime_use_autosuspend(trf->dev);
2152
2153         ret = trf7970a_startup(trf);
2154         if (ret)
2155                 goto err_free_ddev;
2156
2157         ret = nfc_digital_register_device(trf->ddev);
2158         if (ret) {
2159                 dev_err(trf->dev, "Can't register NFC digital device: %d\n",
2160                                 ret);
2161                 goto err_shutdown;
2162         }
2163
2164         return 0;
2165
2166 err_shutdown:
2167         trf7970a_shutdown(trf);
2168 err_free_ddev:
2169         nfc_digital_free_device(trf->ddev);
2170 err_disable_regulator:
2171         regulator_disable(trf->regulator);
2172 err_destroy_lock:
2173         mutex_destroy(&trf->lock);
2174         return ret;
2175 }
2176
2177 static int trf7970a_remove(struct spi_device *spi)
2178 {
2179         struct trf7970a *trf = spi_get_drvdata(spi);
2180
2181         mutex_lock(&trf->lock);
2182
2183         trf7970a_shutdown(trf);
2184
2185         mutex_unlock(&trf->lock);
2186
2187         nfc_digital_unregister_device(trf->ddev);
2188         nfc_digital_free_device(trf->ddev);
2189
2190         regulator_disable(trf->regulator);
2191
2192         mutex_destroy(&trf->lock);
2193
2194         return 0;
2195 }
2196
2197 #ifdef CONFIG_PM_SLEEP
2198 static int trf7970a_suspend(struct device *dev)
2199 {
2200         struct spi_device *spi = to_spi_device(dev);
2201         struct trf7970a *trf = spi_get_drvdata(spi);
2202
2203         dev_dbg(dev, "Suspend\n");
2204
2205         mutex_lock(&trf->lock);
2206
2207         trf7970a_shutdown(trf);
2208
2209         mutex_unlock(&trf->lock);
2210
2211         return 0;
2212 }
2213
2214 static int trf7970a_resume(struct device *dev)
2215 {
2216         struct spi_device *spi = to_spi_device(dev);
2217         struct trf7970a *trf = spi_get_drvdata(spi);
2218         int ret;
2219
2220         dev_dbg(dev, "Resume\n");
2221
2222         mutex_lock(&trf->lock);
2223
2224         ret = trf7970a_startup(trf);
2225
2226         mutex_unlock(&trf->lock);
2227
2228         return ret;
2229 }
2230 #endif
2231
2232 #ifdef CONFIG_PM
2233 static int trf7970a_pm_runtime_suspend(struct device *dev)
2234 {
2235         struct spi_device *spi = to_spi_device(dev);
2236         struct trf7970a *trf = spi_get_drvdata(spi);
2237         int ret;
2238
2239         dev_dbg(dev, "Runtime suspend\n");
2240
2241         mutex_lock(&trf->lock);
2242
2243         ret = trf7970a_power_down(trf);
2244
2245         mutex_unlock(&trf->lock);
2246
2247         return ret;
2248 }
2249
2250 static int trf7970a_pm_runtime_resume(struct device *dev)
2251 {
2252         struct spi_device *spi = to_spi_device(dev);
2253         struct trf7970a *trf = spi_get_drvdata(spi);
2254         int ret;
2255
2256         dev_dbg(dev, "Runtime resume\n");
2257
2258         ret = trf7970a_power_up(trf);
2259         if (!ret)
2260                 pm_runtime_mark_last_busy(dev);
2261
2262         return ret;
2263 }
2264 #endif
2265
2266 static const struct dev_pm_ops trf7970a_pm_ops = {
2267         SET_SYSTEM_SLEEP_PM_OPS(trf7970a_suspend, trf7970a_resume)
2268         SET_RUNTIME_PM_OPS(trf7970a_pm_runtime_suspend,
2269                         trf7970a_pm_runtime_resume, NULL)
2270 };
2271
2272 static const struct of_device_id trf7970a_of_match[] = {
2273         { .compatible = "ti,trf7970a", },
2274         { /* sentinel */ },
2275 };
2276 MODULE_DEVICE_TABLE(of, trf7970a_of_match);
2277
2278 static const struct spi_device_id trf7970a_id_table[] = {
2279         { "trf7970a", 0 },
2280         { }
2281 };
2282 MODULE_DEVICE_TABLE(spi, trf7970a_id_table);
2283
2284 static struct spi_driver trf7970a_spi_driver = {
2285         .probe          = trf7970a_probe,
2286         .remove         = trf7970a_remove,
2287         .id_table       = trf7970a_id_table,
2288         .driver         = {
2289                 .name   = "trf7970a",
2290                 .of_match_table = of_match_ptr(trf7970a_of_match),
2291                 .pm     = &trf7970a_pm_ops,
2292         },
2293 };
2294
2295 module_spi_driver(trf7970a_spi_driver);
2296
2297 MODULE_AUTHOR("Mark A. Greer <mgreer@animalcreek.com>");
2298 MODULE_LICENSE("GPL v2");
2299 MODULE_DESCRIPTION("TI trf7970a RFID/NFC Transceiver Driver");