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/nfc.h>
  20 #include <linux/skbuff.h>
  21 #include <linux/delay.h>
  22 #include <linux/gpio.h>
  23 #include <linux/of.h>
  24 #include <linux/of_gpio.h>
  25 #include <linux/spi/spi.h>
  26 #include <linux/regulator/consumer.h>
  27
  28 #include <net/nfc/nfc.h>
  29 #include <net/nfc/digital.h>
  30
  31 /* There are 3 ways the host can communicate with the trf7970a:
  32  * parallel mode, SPI with Slave Select (SS) mode, and SPI without
  33  * SS mode.  The driver only supports the two SPI modes.
  34  *
  35  * The trf7970a is very timing sensitive and the VIN, EN2, and EN
  36  * pins must asserted in that order and with specific delays in between.
  37  * The delays used in the driver were provided by TI and have been
  38  * confirmed to work with this driver.
  39  *
  40  * Timeouts are implemented using the delayed workqueue kernel facility.
  41  * Timeouts are required so things don't hang when there is no response
  42  * from the trf7970a (or tag).  Using this mechanism creates a race with
  43  * interrupts, however.  That is, an interrupt and a timeout could occur
  44  * closely enough together that one is blocked by the mutex while the other
  45  * executes.  When the timeout handler executes first and blocks the
  46  * interrupt handler, it will eventually set the state to IDLE so the
  47  * interrupt handler will check the state and exit with no harm done.
  48  * When the interrupt handler executes first and blocks the timeout handler,
  49  * the cancel_delayed_work() call will know that it didn't cancel the
  50  * work item (i.e., timeout) and will return zero.  That return code is
  51  * used by the timer handler to indicate that it should ignore the timeout
  52  * once its unblocked.
  53  *
  54  * Aborting an active command isn't as simple as it seems because the only
  55  * way to abort a command that's already been sent to the tag is so turn
  56  * off power to the tag.  If we do that, though, we'd have to go through
  57  * the entire anticollision procedure again but the digital layer doesn't
  58  * support that.  So, if an abort is received before trf7970a_in_send_cmd()
  59  * has sent the command to the tag, it simply returns -ECANCELED.  If the
  60  * command has already been sent to the tag, then the driver continues
  61  * normally and recieves the response data (or error) but just before
  62  * sending the data upstream, it frees the rx_skb and sends -ECANCELED
  63  * upstream instead.  If the command failed, that error will be sent
  64  * upstream.
  65  *
  66  * When recieving data from a tag and the interrupt status register has
  67  * only the SRX bit set, it means that all of the data has been received
  68  * (once what's in the fifo has been read).  However, depending on timing
  69  * an interrupt status with only the SRX bit set may not be recived.  In
  70  * those cases, the timeout mechanism is used to wait 5 ms in case more
  71  * data arrives.  After 5 ms, it is assumed that all of the data has been
  72  * received and the accumulated rx data is sent upstream.  The
  73  * 'TRF7970A_ST_WAIT_FOR_RX_DATA_CONT' state is used for this purpose
  74  * (i.e., it indicates that some data has been received but we're not sure
  75  * if there is more coming so a timeout in this state means all data has
  76  * been received and there isn't an error).  The delay is 5 ms since delays
  77  * over 2 ms have been observed during testing (a little extra just in case).
  78  *
  79  * Type 2 write and sector select commands respond with a 4-bit ACK or NACK.
  80  * Having only 4 bits in the FIFO won't normally generate an interrupt so
  81  * driver enables the '4_bit_RX' bit of the Special Functions register 1
  82  * to cause an interrupt in that case.  Leaving that bit for a read command
  83  * messes up the data returned so it is only enabled when the framing is
  84  * 'NFC_DIGITAL_FRAMING_NFCA_T2T' and the command is not a read command.
  85  * Unfortunately, that means that the driver has to peek into tx frames
  86  * when the framing is 'NFC_DIGITAL_FRAMING_NFCA_T2T'.  This is done by
  87  * the trf7970a_per_cmd_config() routine.
  88  *
  89  * ISO/IEC 15693 frames specify whether to use single or double sub-carrier
  90  * frequencies and whether to use low or high data rates in the flags byte
  91  * of the frame.  This means that the driver has to peek at all 15693 frames
  92  * to determine what speed to set the communication to.  In addition, write
  93  * and lock commands use the OPTION flag to indicate that an EOF must be
  94  * sent to the tag before it will send its response.  So the driver has to
  95  * examine all frames for that reason too.
  96  *
  97  * It is unclear how long to wait before sending the EOF.  According to the
  98  * Note under Table 1-1 in section 1.6 of
  99  * http://www.ti.com/lit/ug/scbu011/scbu011.pdf, that wait should be at least
 100  * 10 ms for TI Tag-it HF-I tags; however testing has shown that is not long
 101  * enough.  For this reason, the driver waits 20 ms which seems to work
 102  * reliably.
 103  */
 104
 105 #define TRF7970A_SUPPORTED_PROTOCOLS \
 106                 (NFC_PROTO_MIFARE_MASK | NFC_PROTO_ISO14443_MASK |      \
 107                  NFC_PROTO_ISO15693_MASK)
 108
 109 /* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
 110  * on what the current framing is, the address of the TX length byte 1
 111  * register (0x1d), and the 2 byte length of the data to be transmitted.
 112  * That totals 5 bytes.
 113  */
 114 #define TRF7970A_TX_SKB_HEADROOM                5
 115
 116 #define TRF7970A_RX_SKB_ALLOC_SIZE              256
 117
 118 #define TRF7970A_FIFO_SIZE                      128
 119
 120 /* TX length is 3 nibbles long ==> 4KB - 1 bytes max */
 121 #define TRF7970A_TX_MAX                         (4096 - 1)
 122
 123 #define TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT       5
 124 #define TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT    3
 125 #define TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF     20
 126
 127 /* Quirks */
 128 /* Erratum: When reading IRQ Status register on trf7970a, we must issue a
 129  * read continuous command for IRQ Status and Collision Position registers.
 130  */
 131 #define TRF7970A_QUIRK_IRQ_STATUS_READ_ERRATA   BIT(0)
 132
 133 /* Direct commands */
 134 #define TRF7970A_CMD_IDLE                       0x00
 135 #define TRF7970A_CMD_SOFT_INIT                  0x03
 136 #define TRF7970A_CMD_RF_COLLISION               0x04
 137 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_N    0x05
 138 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_0    0x06
 139 #define TRF7970A_CMD_FIFO_RESET                 0x0f
 140 #define TRF7970A_CMD_TRANSMIT_NO_CRC            0x10
 141 #define TRF7970A_CMD_TRANSMIT                   0x11
 142 #define TRF7970A_CMD_DELAY_TRANSMIT_NO_CRC      0x12
 143 #define TRF7970A_CMD_DELAY_TRANSMIT             0x13
 144 #define TRF7970A_CMD_EOF                        0x14
 145 #define TRF7970A_CMD_CLOSE_SLOT                 0x15
 146 #define TRF7970A_CMD_BLOCK_RX                   0x16
 147 #define TRF7970A_CMD_ENABLE_RX                  0x17
 148 #define TRF7970A_CMD_TEST_EXT_RF                0x18
 149 #define TRF7970A_CMD_TEST_INT_RF                0x19
 150 #define TRF7970A_CMD_RX_GAIN_ADJUST             0x1a
 151
 152 /* Bits determining whether its a direct command or register R/W,
 153  * whether to use a continuous SPI transaction or not, and the actual
 154  * direct cmd opcode or regster address.
 155  */
 156 #define TRF7970A_CMD_BIT_CTRL                   BIT(7)
 157 #define TRF7970A_CMD_BIT_RW                     BIT(6)
 158 #define TRF7970A_CMD_BIT_CONTINUOUS             BIT(5)
 159 #define TRF7970A_CMD_BIT_OPCODE(opcode)         ((opcode) & 0x1f)
 160
 161 /* Registers addresses */
 162 #define TRF7970A_CHIP_STATUS_CTRL               0x00
 163 #define TRF7970A_ISO_CTRL                       0x01
 164 #define TRF7970A_ISO14443B_TX_OPTIONS           0x02
 165 #define TRF7970A_ISO14443A_HIGH_BITRATE_OPTIONS 0x03
 166 #define TRF7970A_TX_TIMER_SETTING_H_BYTE        0x04
 167 #define TRF7970A_TX_TIMER_SETTING_L_BYTE        0x05
 168 #define TRF7970A_TX_PULSE_LENGTH_CTRL           0x06
 169 #define TRF7970A_RX_NO_RESPONSE_WAIT            0x07
 170 #define TRF7970A_RX_WAIT_TIME                   0x08
 171 #define TRF7970A_MODULATOR_SYS_CLK_CTRL         0x09
 172 #define TRF7970A_RX_SPECIAL_SETTINGS            0x0a
 173 #define TRF7970A_REG_IO_CTRL                    0x0b
 174 #define TRF7970A_IRQ_STATUS                     0x0c
 175 #define TRF7970A_COLLISION_IRQ_MASK             0x0d
 176 #define TRF7970A_COLLISION_POSITION             0x0e
 177 #define TRF7970A_RSSI_OSC_STATUS                0x0f
 178 #define TRF7970A_SPECIAL_FCN_REG1               0x10
 179 #define TRF7970A_SPECIAL_FCN_REG2               0x11
 180 #define TRF7970A_RAM1                           0x12
 181 #define TRF7970A_RAM2                           0x13
 182 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS      0x14
 183 #define TRF7970A_NFC_LOW_FIELD_LEVEL            0x16
 184 #define TRF7970A_NFCID1                         0x17
 185 #define TRF7970A_NFC_TARGET_LEVEL               0x18
 186 #define TRF79070A_NFC_TARGET_PROTOCOL           0x19
 187 #define TRF7970A_TEST_REGISTER1                 0x1a
 188 #define TRF7970A_TEST_REGISTER2                 0x1b
 189 #define TRF7970A_FIFO_STATUS                    0x1c
 190 #define TRF7970A_TX_LENGTH_BYTE1                0x1d
 191 #define TRF7970A_TX_LENGTH_BYTE2                0x1e
 192 #define TRF7970A_FIFO_IO_REGISTER               0x1f
 193
 194 /* Chip Status Control Register Bits */
 195 #define TRF7970A_CHIP_STATUS_VRS5_3             BIT(0)
 196 #define TRF7970A_CHIP_STATUS_REC_ON             BIT(1)
 197 #define TRF7970A_CHIP_STATUS_AGC_ON             BIT(2)
 198 #define TRF7970A_CHIP_STATUS_PM_ON              BIT(3)
 199 #define TRF7970A_CHIP_STATUS_RF_PWR             BIT(4)
 200 #define TRF7970A_CHIP_STATUS_RF_ON              BIT(5)
 201 #define TRF7970A_CHIP_STATUS_DIRECT             BIT(6)
 202 #define TRF7970A_CHIP_STATUS_STBY               BIT(7)
 203
 204 /* ISO Control Register Bits */
 205 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_662    0x00
 206 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_662  0x01
 207 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648   0x02
 208 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_2648 0x03
 209 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a   0x04
 210 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_667  0x05
 211 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669   0x06
 212 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_2669 0x07
 213 #define TRF7970A_ISO_CTRL_14443A_106            0x08
 214 #define TRF7970A_ISO_CTRL_14443A_212            0x09
 215 #define TRF7970A_ISO_CTRL_14443A_424            0x0a
 216 #define TRF7970A_ISO_CTRL_14443A_848            0x0b
 217 #define TRF7970A_ISO_CTRL_14443B_106            0x0c
 218 #define TRF7970A_ISO_CTRL_14443B_212            0x0d
 219 #define TRF7970A_ISO_CTRL_14443B_424            0x0e
 220 #define TRF7970A_ISO_CTRL_14443B_848            0x0f
 221 #define TRF7970A_ISO_CTRL_FELICA_212            0x1a
 222 #define TRF7970A_ISO_CTRL_FELICA_424            0x1b
 223 #define TRF7970A_ISO_CTRL_RFID                  BIT(5)
 224 #define TRF7970A_ISO_CTRL_DIR_MODE              BIT(6)
 225 #define TRF7970A_ISO_CTRL_RX_CRC_N              BIT(7)  /* true == No CRC */
 226
 227 #define TRF7970A_ISO_CTRL_RFID_SPEED_MASK       0x1f
 228
 229 /* Modulator and SYS_CLK Control Register Bits */
 230 #define TRF7970A_MODULATOR_DEPTH(n)             ((n) & 0x7)
 231 #define TRF7970A_MODULATOR_DEPTH_ASK10          (TRF7970A_MODULATOR_DEPTH(0))
 232 #define TRF7970A_MODULATOR_DEPTH_OOK            (TRF7970A_MODULATOR_DEPTH(1))
 233 #define TRF7970A_MODULATOR_DEPTH_ASK7           (TRF7970A_MODULATOR_DEPTH(2))
 234 #define TRF7970A_MODULATOR_DEPTH_ASK8_5         (TRF7970A_MODULATOR_DEPTH(3))
 235 #define TRF7970A_MODULATOR_DEPTH_ASK13          (TRF7970A_MODULATOR_DEPTH(4))
 236 #define TRF7970A_MODULATOR_DEPTH_ASK16          (TRF7970A_MODULATOR_DEPTH(5))
 237 #define TRF7970A_MODULATOR_DEPTH_ASK22          (TRF7970A_MODULATOR_DEPTH(6))
 238 #define TRF7970A_MODULATOR_DEPTH_ASK30          (TRF7970A_MODULATOR_DEPTH(7))
 239 #define TRF7970A_MODULATOR_EN_ANA               BIT(3)
 240 #define TRF7970A_MODULATOR_CLK(n)               (((n) & 0x3) << 4)
 241 #define TRF7970A_MODULATOR_CLK_DISABLED         (TRF7970A_MODULATOR_CLK(0))
 242 #define TRF7970A_MODULATOR_CLK_3_6              (TRF7970A_MODULATOR_CLK(1))
 243 #define TRF7970A_MODULATOR_CLK_6_13             (TRF7970A_MODULATOR_CLK(2))
 244 #define TRF7970A_MODULATOR_CLK_13_27            (TRF7970A_MODULATOR_CLK(3))
 245 #define TRF7970A_MODULATOR_EN_OOK               BIT(6)
 246 #define TRF7970A_MODULATOR_27MHZ                BIT(7)
 247
 248 /* IRQ Status Register Bits */
 249 #define TRF7970A_IRQ_STATUS_NORESP              BIT(0) /* ISO15693 only */
 250 #define TRF7970A_IRQ_STATUS_COL                 BIT(1)
 251 #define TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR   BIT(2)
 252 #define TRF7970A_IRQ_STATUS_PARITY_ERROR        BIT(3)
 253 #define TRF7970A_IRQ_STATUS_CRC_ERROR           BIT(4)
 254 #define TRF7970A_IRQ_STATUS_FIFO                BIT(5)
 255 #define TRF7970A_IRQ_STATUS_SRX                 BIT(6)
 256 #define TRF7970A_IRQ_STATUS_TX                  BIT(7)
 257
 258 #define TRF7970A_IRQ_STATUS_ERROR                               \
 259                 (TRF7970A_IRQ_STATUS_COL |                      \
 260                  TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR |        \
 261                  TRF7970A_IRQ_STATUS_PARITY_ERROR |             \
 262                  TRF7970A_IRQ_STATUS_CRC_ERROR)
 263
 264 #define TRF7970A_SPECIAL_FCN_REG1_COL_7_6               BIT(0)
 265 #define TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL           BIT(1)
 266 #define TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX              BIT(2)
 267 #define TRF7970A_SPECIAL_FCN_REG1_SP_DIR_MODE           BIT(3)
 268 #define TRF7970A_SPECIAL_FCN_REG1_NEXT_SLOT_37US        BIT(4)
 269 #define TRF7970A_SPECIAL_FCN_REG1_PAR43                 BIT(5)
 270
 271 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_124      (0x0 << 2)
 272 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_120      (0x1 << 2)
 273 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_112      (0x2 << 2)
 274 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96       (0x3 << 2)
 275 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_4        0x0
 276 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_8        0x1
 277 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_16       0x2
 278 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32       0x3
 279
 280 #define TRF7970A_FIFO_STATUS_OVERFLOW           BIT(7)
 281
 282 /* NFC (ISO/IEC 14443A) Type 2 Tag commands */
 283 #define NFC_T2T_CMD_READ                        0x30
 284
 285 /* ISO 15693 commands codes */
 286 #define ISO15693_CMD_INVENTORY                  0x01
 287 #define ISO15693_CMD_READ_SINGLE_BLOCK          0x20
 288 #define ISO15693_CMD_WRITE_SINGLE_BLOCK         0x21
 289 #define ISO15693_CMD_LOCK_BLOCK                 0x22
 290 #define ISO15693_CMD_READ_MULTIPLE_BLOCK        0x23
 291 #define ISO15693_CMD_WRITE_MULTIPLE_BLOCK       0x24
 292 #define ISO15693_CMD_SELECT                     0x25
 293 #define ISO15693_CMD_RESET_TO_READY             0x26
 294 #define ISO15693_CMD_WRITE_AFI                  0x27
 295 #define ISO15693_CMD_LOCK_AFI                   0x28
 296 #define ISO15693_CMD_WRITE_DSFID                0x29
 297 #define ISO15693_CMD_LOCK_DSFID                 0x2a
 298 #define ISO15693_CMD_GET_SYSTEM_INFO            0x2b
 299 #define ISO15693_CMD_GET_MULTIPLE_BLOCK_SECURITY_STATUS 0x2c
 300
 301 /* ISO 15693 request and response flags */
 302 #define ISO15693_REQ_FLAG_SUB_CARRIER           BIT(0)
 303 #define ISO15693_REQ_FLAG_DATA_RATE             BIT(1)
 304 #define ISO15693_REQ_FLAG_INVENTORY             BIT(2)
 305 #define ISO15693_REQ_FLAG_PROTOCOL_EXT          BIT(3)
 306 #define ISO15693_REQ_FLAG_SELECT                BIT(4)
 307 #define ISO15693_REQ_FLAG_AFI                   BIT(4)
 308 #define ISO15693_REQ_FLAG_ADDRESS               BIT(5)
 309 #define ISO15693_REQ_FLAG_NB_SLOTS              BIT(5)
 310 #define ISO15693_REQ_FLAG_OPTION                BIT(6)
 311
 312 #define ISO15693_REQ_FLAG_SPEED_MASK \
 313                 (ISO15693_REQ_FLAG_SUB_CARRIER | ISO15693_REQ_FLAG_DATA_RATE)
 314
 315 enum trf7970a_state {
 316         TRF7970A_ST_OFF,
 317         TRF7970A_ST_IDLE,
 318         TRF7970A_ST_IDLE_RX_BLOCKED,
 319         TRF7970A_ST_WAIT_FOR_TX_FIFO,
 320         TRF7970A_ST_WAIT_FOR_RX_DATA,
 321         TRF7970A_ST_WAIT_FOR_RX_DATA_CONT,
 322         TRF7970A_ST_WAIT_TO_ISSUE_EOF,
 323         TRF7970A_ST_MAX
 324 };
 325
 326 struct trf7970a {
 327         enum trf7970a_state             state;
 328         struct device                   *dev;
 329         struct spi_device               *spi;
 330         struct regulator                *regulator;
 331         struct nfc_digital_dev          *ddev;
 332         u32                             quirks;
 333         bool                            powering_up;
 334         bool                            aborting;
 335         struct sk_buff                  *tx_skb;
 336         struct sk_buff                  *rx_skb;
 337         nfc_digital_cmd_complete_t      cb;
 338         void                            *cb_arg;
 339         u8                              iso_ctrl;
 340         u8                              special_fcn_reg1;
 341         int                             technology;
 342         int                             framing;
 343         u8                              tx_cmd;
 344         bool                            issue_eof;
 345         int                             en2_gpio;
 346         int                             en_gpio;
 347         struct mutex                    lock;
 348         unsigned int                    timeout;
 349         bool                            ignore_timeout;
 350         struct delayed_work             timeout_work;
 351 };
 352
 353
 354 static int trf7970a_cmd(struct trf7970a *trf, u8 opcode)
 355 {
 356         u8 cmd = TRF7970A_CMD_BIT_CTRL | TRF7970A_CMD_BIT_OPCODE(opcode);
 357         int ret;
 358
 359         dev_dbg(trf->dev, "cmd: 0x%x\n", cmd);
 360
 361         ret = spi_write(trf->spi, &cmd, 1);
 362         if (ret)
 363                 dev_err(trf->dev, "%s - cmd: 0x%x, ret: %d\n", __func__, cmd,
 364                                 ret);
 365         return ret;
 366 }
 367
 368 static int trf7970a_read(struct trf7970a *trf, u8 reg, u8 *val)
 369 {
 370         u8 addr = TRF7970A_CMD_BIT_RW | reg;
 371         int ret;
 372
 373         ret = spi_write_then_read(trf->spi, &addr, 1, val, 1);
 374         if (ret)
 375                 dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
 376                                 ret);
 377
 378         dev_dbg(trf->dev, "read(0x%x): 0x%x\n", addr, *val);
 379
 380         return ret;
 381 }
 382
 383 static int trf7970a_read_cont(struct trf7970a *trf, u8 reg,
 384                 u8 *buf, size_t len)
 385 {
 386         u8 addr = reg | TRF7970A_CMD_BIT_RW | TRF7970A_CMD_BIT_CONTINUOUS;
 387         int ret;
 388
 389         dev_dbg(trf->dev, "read_cont(0x%x, %zd)\n", addr, len);
 390
 391         ret = spi_write_then_read(trf->spi, &addr, 1, buf, len);
 392         if (ret)
 393                 dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
 394                                 ret);
 395         return ret;
 396 }
 397
 398 static int trf7970a_write(struct trf7970a *trf, u8 reg, u8 val)
 399 {
 400         u8 buf[2] = { reg, val };
 401         int ret;
 402
 403         dev_dbg(trf->dev, "write(0x%x): 0x%x\n", reg, val);
 404
 405         ret = spi_write(trf->spi, buf, 2);
 406         if (ret)
 407                 dev_err(trf->dev, "%s - write: 0x%x 0x%x, ret: %d\n", __func__,
 408                                 buf[0], buf[1], ret);
 409
 410         return ret;
 411 }
 412
 413 static int trf7970a_read_irqstatus(struct trf7970a *trf, u8 *status)
 414 {
 415         int ret;
 416         u8 buf[2];
 417         u8 addr;
 418
 419         addr = TRF7970A_IRQ_STATUS | TRF7970A_CMD_BIT_RW;
 420
 421         if (trf->quirks & TRF7970A_QUIRK_IRQ_STATUS_READ_ERRATA) {
 422                 addr |= TRF7970A_CMD_BIT_CONTINUOUS;
 423                 ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
 424         } else {
 425                 ret = spi_write_then_read(trf->spi, &addr, 1, buf, 1);
 426         }
 427
 428         if (ret)
 429                 dev_err(trf->dev, "%s - irqstatus: Status read failed: %d\n",
 430                                 __func__, ret);
 431         else
 432                 *status = buf[0];
 433
 434         return ret;
 435 }
 436
 437 static void trf7970a_send_upstream(struct trf7970a *trf)
 438 {
 439         u8 rssi;
 440
 441         dev_kfree_skb_any(trf->tx_skb);
 442         trf->tx_skb = NULL;
 443
 444         if (trf->rx_skb && !IS_ERR(trf->rx_skb) && !trf->aborting)
 445                 print_hex_dump_debug("trf7970a rx data: ", DUMP_PREFIX_NONE,
 446                                 16, 1, trf->rx_skb->data, trf->rx_skb->len,
 447                                 false);
 448
 449         /* According to the manual it is "good form" to reset the fifo and
 450          * read the RSSI levels & oscillator status register here.  It doesn't
 451          * explain why.
 452          */
 453         trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 454         trf7970a_read(trf, TRF7970A_RSSI_OSC_STATUS, &rssi);
 455
 456         trf->state = TRF7970A_ST_IDLE;
 457
 458         if (trf->aborting) {
 459                 dev_dbg(trf->dev, "Abort process complete\n");
 460
 461                 if (!IS_ERR(trf->rx_skb)) {
 462                         kfree_skb(trf->rx_skb);
 463                         trf->rx_skb = ERR_PTR(-ECANCELED);
 464                 }
 465
 466                 trf->aborting = false;
 467         }
 468
 469         trf->cb(trf->ddev, trf->cb_arg, trf->rx_skb);
 470
 471         trf->rx_skb = NULL;
 472 }
 473
 474 static void trf7970a_send_err_upstream(struct trf7970a *trf, int errno)
 475 {
 476         dev_dbg(trf->dev, "Error - state: %d, errno: %d\n", trf->state, errno);
 477
 478         kfree_skb(trf->rx_skb);
 479         trf->rx_skb = ERR_PTR(errno);
 480
 481         trf7970a_send_upstream(trf);
 482 }
 483
 484 static int trf7970a_transmit(struct trf7970a *trf, struct sk_buff *skb,
 485                 unsigned int len)
 486 {
 487         unsigned int timeout;
 488         int ret;
 489
 490         print_hex_dump_debug("trf7970a tx data: ", DUMP_PREFIX_NONE,
 491                         16, 1, skb->data, len, false);
 492
 493         ret = spi_write(trf->spi, skb->data, len);
 494         if (ret) {
 495                 dev_err(trf->dev, "%s - Can't send tx data: %d\n", __func__,
 496                                 ret);
 497                 return ret;
 498         }
 499
 500         skb_pull(skb, len);
 501
 502         if (skb->len > 0) {
 503                 trf->state = TRF7970A_ST_WAIT_FOR_TX_FIFO;
 504                 timeout = TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT;
 505         } else {
 506                 if (trf->issue_eof) {
 507                         trf->state = TRF7970A_ST_WAIT_TO_ISSUE_EOF;
 508                         timeout = TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF;
 509                 } else {
 510                         trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
 511                         timeout = trf->timeout;
 512                 }
 513         }
 514
 515         dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n", timeout,
 516                         trf->state);
 517
 518         schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
 519
 520         return 0;
 521 }
 522
 523 static void trf7970a_fill_fifo(struct trf7970a *trf)
 524 {
 525         struct sk_buff *skb = trf->tx_skb;
 526         unsigned int len;
 527         int ret;
 528         u8 fifo_bytes;
 529
 530         ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
 531         if (ret) {
 532                 trf7970a_send_err_upstream(trf, ret);
 533                 return;
 534         }
 535
 536         dev_dbg(trf->dev, "Filling FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
 537
 538         if (fifo_bytes & TRF7970A_FIFO_STATUS_OVERFLOW) {
 539                 dev_err(trf->dev, "%s - fifo overflow: 0x%x\n", __func__,
 540                                 fifo_bytes);
 541                 trf7970a_send_err_upstream(trf, -EIO);
 542                 return;
 543         }
 544
 545         /* Calculate how much more data can be written to the fifo */
 546         len = TRF7970A_FIFO_SIZE - fifo_bytes;
 547         len = min(skb->len, len);
 548
 549         ret = trf7970a_transmit(trf, skb, len);
 550         if (ret)
 551                 trf7970a_send_err_upstream(trf, ret);
 552 }
 553
 554 static void trf7970a_drain_fifo(struct trf7970a *trf, u8 status)
 555 {
 556         struct sk_buff *skb = trf->rx_skb;
 557         int ret;
 558         u8 fifo_bytes;
 559
 560         if (status & TRF7970A_IRQ_STATUS_ERROR) {
 561                 trf7970a_send_err_upstream(trf, -EIO);
 562                 return;
 563         }
 564
 565         ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
 566         if (ret) {
 567                 trf7970a_send_err_upstream(trf, ret);
 568                 return;
 569         }
 570
 571         dev_dbg(trf->dev, "Draining FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
 572
 573         if (!fifo_bytes)
 574                 goto no_rx_data;
 575
 576         if (fifo_bytes & TRF7970A_FIFO_STATUS_OVERFLOW) {
 577                 dev_err(trf->dev, "%s - fifo overflow: 0x%x\n", __func__,
 578                                 fifo_bytes);
 579                 trf7970a_send_err_upstream(trf, -EIO);
 580                 return;
 581         }
 582
 583         if (fifo_bytes > skb_tailroom(skb)) {
 584                 skb = skb_copy_expand(skb, skb_headroom(skb),
 585                                 max_t(int, fifo_bytes,
 586                                         TRF7970A_RX_SKB_ALLOC_SIZE),
 587                                 GFP_KERNEL);
 588                 if (!skb) {
 589                         trf7970a_send_err_upstream(trf, -ENOMEM);
 590                         return;
 591                 }
 592
 593                 kfree_skb(trf->rx_skb);
 594                 trf->rx_skb = skb;
 595         }
 596
 597         ret = trf7970a_read_cont(trf, TRF7970A_FIFO_IO_REGISTER,
 598                         skb_put(skb, fifo_bytes), fifo_bytes);
 599         if (ret) {
 600                 trf7970a_send_err_upstream(trf, ret);
 601                 return;
 602         }
 603
 604         /* If received Type 2 ACK/NACK, shift right 4 bits and pass up */
 605         if ((trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T) && (skb->len == 1) &&
 606                         (trf->special_fcn_reg1 ==
 607                                  TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX)) {
 608                 skb->data[0] >>= 4;
 609                 status = TRF7970A_IRQ_STATUS_SRX;
 610         } else {
 611                 trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA_CONT;
 612         }
 613
 614 no_rx_data:
 615         if (status == TRF7970A_IRQ_STATUS_SRX) { /* Receive complete */
 616                 trf7970a_send_upstream(trf);
 617                 return;
 618         }
 619
 620         dev_dbg(trf->dev, "Setting timeout for %d ms\n",
 621                         TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT);
 622
 623         schedule_delayed_work(&trf->timeout_work,
 624                         msecs_to_jiffies(TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT));
 625 }
 626
 627 static irqreturn_t trf7970a_irq(int irq, void *dev_id)
 628 {
 629         struct trf7970a *trf = dev_id;
 630         int ret;
 631         u8 status;
 632
 633         mutex_lock(&trf->lock);
 634
 635         if (trf->state == TRF7970A_ST_OFF) {
 636                 mutex_unlock(&trf->lock);
 637                 return IRQ_NONE;
 638         }
 639
 640         ret = trf7970a_read_irqstatus(trf, &status);
 641         if (ret) {
 642                 mutex_unlock(&trf->lock);
 643                 return IRQ_NONE;
 644         }
 645
 646         dev_dbg(trf->dev, "IRQ - state: %d, status: 0x%x\n", trf->state,
 647                         status);
 648
 649         if (!status) {
 650                 mutex_unlock(&trf->lock);
 651                 return IRQ_NONE;
 652         }
 653
 654         switch (trf->state) {
 655         case TRF7970A_ST_IDLE:
 656         case TRF7970A_ST_IDLE_RX_BLOCKED:
 657                 /* If getting interrupts caused by RF noise, turn off the
 658                  * receiver to avoid unnecessary interrupts.  It will be
 659                  * turned back on in trf7970a_in_send_cmd() when the next
 660                  * command is issued.
 661                  */
 662                 if (status & TRF7970A_IRQ_STATUS_ERROR) {
 663                         trf7970a_cmd(trf, TRF7970A_CMD_BLOCK_RX);
 664                         trf->state = TRF7970A_ST_IDLE_RX_BLOCKED;
 665                 }
 666
 667                 trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 668                 break;
 669         case TRF7970A_ST_WAIT_FOR_TX_FIFO:
 670                 if (status & TRF7970A_IRQ_STATUS_TX) {
 671                         trf->ignore_timeout =
 672                                 !cancel_delayed_work(&trf->timeout_work);
 673                         trf7970a_fill_fifo(trf);
 674                 } else {
 675                         trf7970a_send_err_upstream(trf, -EIO);
 676                 }
 677                 break;
 678         case TRF7970A_ST_WAIT_FOR_RX_DATA:
 679         case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
 680                 if (status & TRF7970A_IRQ_STATUS_SRX) {
 681                         trf->ignore_timeout =
 682                                 !cancel_delayed_work(&trf->timeout_work);
 683                         trf7970a_drain_fifo(trf, status);
 684                 } else if (!(status & TRF7970A_IRQ_STATUS_TX)) {
 685                         trf7970a_send_err_upstream(trf, -EIO);
 686                 }
 687                 break;
 688         case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
 689                 if (status != TRF7970A_IRQ_STATUS_TX)
 690                         trf7970a_send_err_upstream(trf, -EIO);
 691                 break;
 692         default:
 693                 dev_err(trf->dev, "%s - Driver in invalid state: %d\n",
 694                                 __func__, trf->state);
 695         }
 696
 697         mutex_unlock(&trf->lock);
 698         return IRQ_HANDLED;
 699 }
 700
 701 static void trf7970a_issue_eof(struct trf7970a *trf)
 702 {
 703         int ret;
 704
 705         dev_dbg(trf->dev, "Issuing EOF\n");
 706
 707         ret = trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 708         if (ret)
 709                 trf7970a_send_err_upstream(trf, ret);
 710
 711         ret = trf7970a_cmd(trf, TRF7970A_CMD_EOF);
 712         if (ret)
 713                 trf7970a_send_err_upstream(trf, ret);
 714
 715         trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
 716
 717         dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n",
 718                         trf->timeout, trf->state);
 719
 720         schedule_delayed_work(&trf->timeout_work,
 721                         msecs_to_jiffies(trf->timeout));
 722 }
 723
 724 static void trf7970a_timeout_work_handler(struct work_struct *work)
 725 {
 726         struct trf7970a *trf = container_of(work, struct trf7970a,
 727                         timeout_work.work);
 728
 729         dev_dbg(trf->dev, "Timeout - state: %d, ignore_timeout: %d\n",
 730                         trf->state, trf->ignore_timeout);
 731
 732         mutex_lock(&trf->lock);
 733
 734         if (trf->ignore_timeout)
 735                 trf->ignore_timeout = false;
 736         else if (trf->state == TRF7970A_ST_WAIT_FOR_RX_DATA_CONT)
 737                 trf7970a_send_upstream(trf); /* No more rx data so send up */
 738         else if (trf->state == TRF7970A_ST_WAIT_TO_ISSUE_EOF)
 739                 trf7970a_issue_eof(trf);
 740         else
 741                 trf7970a_send_err_upstream(trf, -ETIMEDOUT);
 742
 743         mutex_unlock(&trf->lock);
 744 }
 745
 746 static int trf7970a_init(struct trf7970a *trf)
 747 {
 748         int ret;
 749
 750         dev_dbg(trf->dev, "Initializing device - state: %d\n", trf->state);
 751
 752         ret = trf7970a_cmd(trf, TRF7970A_CMD_SOFT_INIT);
 753         if (ret)
 754                 goto err_out;
 755
 756         ret = trf7970a_cmd(trf, TRF7970A_CMD_IDLE);
 757         if (ret)
 758                 goto err_out;
 759
 760         ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
 761                         TRF7970A_MODULATOR_DEPTH_OOK);
 762         if (ret)
 763                 goto err_out;
 764
 765         ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS,
 766                         TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 |
 767                         TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32);
 768         if (ret)
 769                 goto err_out;
 770
 771         ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1, 0);
 772         if (ret)
 773                 goto err_out;
 774
 775         trf->special_fcn_reg1 = 0;
 776
 777         ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
 778                         TRF7970A_CHIP_STATUS_RF_ON |
 779                                 TRF7970A_CHIP_STATUS_VRS5_3);
 780         if (ret)
 781                 goto err_out;
 782
 783         return 0;
 784
 785 err_out:
 786         dev_dbg(trf->dev, "Couldn't init device: %d\n", ret);
 787         return ret;
 788 }
 789
 790 static void trf7970a_switch_rf_off(struct trf7970a *trf)
 791 {
 792         dev_dbg(trf->dev, "Switching rf off\n");
 793
 794         gpio_set_value(trf->en_gpio, 0);
 795         gpio_set_value(trf->en2_gpio, 0);
 796
 797         trf->aborting = false;
 798         trf->state = TRF7970A_ST_OFF;
 799 }
 800
 801 static int trf7970a_switch_rf_on(struct trf7970a *trf)
 802 {
 803         unsigned long delay;
 804         int ret;
 805
 806         dev_dbg(trf->dev, "Switching rf on\n");
 807
 808         if (trf->powering_up)
 809                 usleep_range(5000, 6000);
 810
 811         gpio_set_value(trf->en2_gpio, 1);
 812         usleep_range(1000, 2000);
 813         gpio_set_value(trf->en_gpio, 1);
 814
 815         /* The delay between enabling the trf7970a and issuing the first
 816          * command is significantly longer the very first time after powering
 817          * up.  Make sure the longer delay is only done the first time.
 818          */
 819         if (trf->powering_up) {
 820                 delay = 20000;
 821                 trf->powering_up = false;
 822         } else {
 823                 delay = 5000;
 824         }
 825
 826         usleep_range(delay, delay + 1000);
 827
 828         ret = trf7970a_init(trf);
 829         if (ret)
 830                 trf7970a_switch_rf_off(trf);
 831         else
 832                 trf->state = TRF7970A_ST_IDLE;
 833
 834         return ret;
 835 }
 836
 837 static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on)
 838 {
 839         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
 840         int ret = 0;
 841
 842         dev_dbg(trf->dev, "Switching RF - state: %d, on: %d\n", trf->state, on);
 843
 844         mutex_lock(&trf->lock);
 845
 846         if (on) {
 847                 switch (trf->state) {
 848                 case TRF7970A_ST_OFF:
 849                         ret = trf7970a_switch_rf_on(trf);
 850                         break;
 851                 case TRF7970A_ST_IDLE:
 852                 case TRF7970A_ST_IDLE_RX_BLOCKED:
 853                         break;
 854                 default:
 855                         dev_err(trf->dev, "%s - Invalid request: %d %d\n",
 856                                         __func__, trf->state, on);
 857                         trf7970a_switch_rf_off(trf);
 858                 }
 859         } else {
 860                 switch (trf->state) {
 861                 case TRF7970A_ST_OFF:
 862                         break;
 863                 default:
 864                         dev_err(trf->dev, "%s - Invalid request: %d %d\n",
 865                                         __func__, trf->state, on);
 866                         /* FALLTHROUGH */
 867                 case TRF7970A_ST_IDLE:
 868                 case TRF7970A_ST_IDLE_RX_BLOCKED:
 869                         trf7970a_switch_rf_off(trf);
 870                 }
 871         }
 872
 873         mutex_unlock(&trf->lock);
 874         return ret;
 875 }
 876
 877 static int trf7970a_config_rf_tech(struct trf7970a *trf, int tech)
 878 {
 879         int ret = 0;
 880
 881         dev_dbg(trf->dev, "rf technology: %d\n", tech);
 882
 883         switch (tech) {
 884         case NFC_DIGITAL_RF_TECH_106A:
 885                 trf->iso_ctrl = TRF7970A_ISO_CTRL_14443A_106;
 886                 break;
 887         case NFC_DIGITAL_RF_TECH_ISO15693:
 888                 trf->iso_ctrl = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
 889                 break;
 890         default:
 891                 dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
 892                 return -EINVAL;
 893         }
 894
 895         trf->technology = tech;
 896
 897         return ret;
 898 }
 899
 900 static int trf7970a_config_framing(struct trf7970a *trf, int framing)
 901 {
 902         dev_dbg(trf->dev, "framing: %d\n", framing);
 903
 904         switch (framing) {
 905         case NFC_DIGITAL_FRAMING_NFCA_SHORT:
 906         case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
 907                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
 908                 trf->iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
 909                 break;
 910         case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
 911         case NFC_DIGITAL_FRAMING_NFCA_T4T:
 912         case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY:
 913         case NFC_DIGITAL_FRAMING_ISO15693_T5T:
 914                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
 915                 trf->iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
 916                 break;
 917         case NFC_DIGITAL_FRAMING_NFCA_T2T:
 918                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
 919                 trf->iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
 920                 break;
 921         default:
 922                 dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
 923                 return -EINVAL;
 924         }
 925
 926         trf->framing = framing;
 927
 928         return trf7970a_write(trf, TRF7970A_ISO_CTRL, trf->iso_ctrl);
 929 }
 930
 931 static int trf7970a_in_configure_hw(struct nfc_digital_dev *ddev, int type,
 932                 int param)
 933 {
 934         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
 935         int ret = 0;
 936
 937         dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
 938
 939         mutex_lock(&trf->lock);
 940
 941         if (trf->state == TRF7970A_ST_OFF) {
 942                 ret = trf7970a_switch_rf_on(trf);
 943                 if (ret)
 944                         goto err_out;
 945         }
 946
 947         switch (type) {
 948         case NFC_DIGITAL_CONFIG_RF_TECH:
 949                 ret = trf7970a_config_rf_tech(trf, param);
 950                 break;
 951         case NFC_DIGITAL_CONFIG_FRAMING:
 952                 ret = trf7970a_config_framing(trf, param);
 953                 break;
 954         default:
 955                 dev_dbg(trf->dev, "Unknown type: %d\n", type);
 956                 ret = -EINVAL;
 957         }
 958
 959 err_out:
 960         mutex_unlock(&trf->lock);
 961         return ret;
 962 }
 963
 964 static int trf7970a_is_iso15693_write_or_lock(u8 cmd)
 965 {
 966         switch (cmd) {
 967         case ISO15693_CMD_WRITE_SINGLE_BLOCK:
 968         case ISO15693_CMD_LOCK_BLOCK:
 969         case ISO15693_CMD_WRITE_MULTIPLE_BLOCK:
 970         case ISO15693_CMD_WRITE_AFI:
 971         case ISO15693_CMD_LOCK_AFI:
 972         case ISO15693_CMD_WRITE_DSFID:
 973         case ISO15693_CMD_LOCK_DSFID:
 974                 return 1;
 975                 break;
 976         default:
 977                 return 0;
 978         }
 979 }
 980
 981 static int trf7970a_per_cmd_config(struct trf7970a *trf, struct sk_buff *skb)
 982 {
 983         u8 *req = skb->data;
 984         u8 special_fcn_reg1, iso_ctrl;
 985         int ret;
 986
 987         trf->issue_eof = false;
 988
 989         /* When issuing Type 2 read command, make sure the '4_bit_RX' bit in
 990          * special functions register 1 is cleared; otherwise, its a write or
 991          * sector select command and '4_bit_RX' must be set.
 992          *
 993          * When issuing an ISO 15693 command, inspect the flags byte to see
 994          * what speed to use.  Also, remember if the OPTION flag is set on
 995          * a Type 5 write or lock command so the driver will know that it
 996          * has to send an EOF in order to get a response.
 997          */
 998         if ((trf->technology == NFC_DIGITAL_RF_TECH_106A) &&
 999                         (trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T)) {
1000                 if (req[0] == NFC_T2T_CMD_READ)
1001                         special_fcn_reg1 = 0;
1002                 else
1003                         special_fcn_reg1 = TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX;
1004
1005                 if (special_fcn_reg1 != trf->special_fcn_reg1) {
1006                         ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1,
1007                                         special_fcn_reg1);
1008                         if (ret)
1009                                 return ret;
1010
1011                         trf->special_fcn_reg1 = special_fcn_reg1;
1012                 }
1013         } else if (trf->technology == NFC_DIGITAL_RF_TECH_ISO15693) {
1014                 iso_ctrl = trf->iso_ctrl & ~TRF7970A_ISO_CTRL_RFID_SPEED_MASK;
1015
1016                 switch (req[0] & ISO15693_REQ_FLAG_SPEED_MASK) {
1017                 case 0x00:
1018                         iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_662;
1019                         break;
1020                 case ISO15693_REQ_FLAG_SUB_CARRIER:
1021                         iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a;
1022                         break;
1023                 case ISO15693_REQ_FLAG_DATA_RATE:
1024                         iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1025                         break;
1026                 case (ISO15693_REQ_FLAG_SUB_CARRIER |
1027                                 ISO15693_REQ_FLAG_DATA_RATE):
1028                         iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669;
1029                         break;
1030                 }
1031
1032                 if (iso_ctrl != trf->iso_ctrl) {
1033                         ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1034                         if (ret)
1035                                 return ret;
1036
1037                         trf->iso_ctrl = iso_ctrl;
1038                 }
1039
1040                 if ((trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) &&
1041                                 trf7970a_is_iso15693_write_or_lock(req[1]) &&
1042                                 (req[0] & ISO15693_REQ_FLAG_OPTION))
1043                         trf->issue_eof = true;
1044         }
1045
1046         return 0;
1047 }
1048
1049 static int trf7970a_in_send_cmd(struct nfc_digital_dev *ddev,
1050                 struct sk_buff *skb, u16 timeout,
1051                 nfc_digital_cmd_complete_t cb, void *arg)
1052 {
1053         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1054         char *prefix;
1055         unsigned int len;
1056         int ret;
1057
1058         dev_dbg(trf->dev, "New request - state: %d, timeout: %d ms, len: %d\n",
1059                         trf->state, timeout, skb->len);
1060
1061         if (skb->len > TRF7970A_TX_MAX)
1062                 return -EINVAL;
1063
1064         mutex_lock(&trf->lock);
1065
1066         if ((trf->state != TRF7970A_ST_IDLE) &&
1067                         (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1068                 dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1069                                 trf->state);
1070                 ret = -EIO;
1071                 goto out_err;
1072         }
1073
1074         if (trf->aborting) {
1075                 dev_dbg(trf->dev, "Abort process complete\n");
1076                 trf->aborting = false;
1077                 ret = -ECANCELED;
1078                 goto out_err;
1079         }
1080
1081         trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1082                         GFP_KERNEL);
1083         if (!trf->rx_skb) {
1084                 dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1085                 ret = -ENOMEM;
1086                 goto out_err;
1087         }
1088
1089         if (trf->state == TRF7970A_ST_IDLE_RX_BLOCKED) {
1090                 ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1091                 if (ret)
1092                         goto out_err;
1093
1094                 trf->state = TRF7970A_ST_IDLE;
1095         }
1096
1097         ret = trf7970a_per_cmd_config(trf, skb);
1098         if (ret)
1099                 goto out_err;
1100
1101         trf->ddev = ddev;
1102         trf->tx_skb = skb;
1103         trf->cb = cb;
1104         trf->cb_arg = arg;
1105         trf->timeout = timeout;
1106         trf->ignore_timeout = false;
1107
1108         len = skb->len;
1109         prefix = skb_push(skb, TRF7970A_TX_SKB_HEADROOM);
1110
1111         /* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
1112          * on what the current framing is, the address of the TX length byte 1
1113          * register (0x1d), and the 2 byte length of the data to be transmitted.
1114          */
1115         prefix[0] = TRF7970A_CMD_BIT_CTRL |
1116                         TRF7970A_CMD_BIT_OPCODE(TRF7970A_CMD_FIFO_RESET);
1117         prefix[1] = TRF7970A_CMD_BIT_CTRL |
1118                         TRF7970A_CMD_BIT_OPCODE(trf->tx_cmd);
1119         prefix[2] = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_TX_LENGTH_BYTE1;
1120
1121         if (trf->framing == NFC_DIGITAL_FRAMING_NFCA_SHORT) {
1122                 prefix[3] = 0x00;
1123                 prefix[4] = 0x0f; /* 7 bits */
1124         } else {
1125                 prefix[3] = (len & 0xf00) >> 4;
1126                 prefix[3] |= ((len & 0xf0) >> 4);
1127                 prefix[4] = ((len & 0x0f) << 4);
1128         }
1129
1130         len = min_t(int, skb->len, TRF7970A_FIFO_SIZE);
1131
1132         usleep_range(1000, 2000);
1133
1134         ret = trf7970a_transmit(trf, skb, len);
1135         if (ret) {
1136                 kfree_skb(trf->rx_skb);
1137                 trf->rx_skb = NULL;
1138         }
1139
1140 out_err:
1141         mutex_unlock(&trf->lock);
1142         return ret;
1143 }
1144
1145 static int trf7970a_tg_configure_hw(struct nfc_digital_dev *ddev,
1146                 int type, int param)
1147 {
1148         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1149
1150         dev_dbg(trf->dev, "Unsupported interface\n");
1151
1152         return -EINVAL;
1153 }
1154
1155 static int trf7970a_tg_send_cmd(struct nfc_digital_dev *ddev,
1156                 struct sk_buff *skb, u16 timeout,
1157                 nfc_digital_cmd_complete_t cb, void *arg)
1158 {
1159         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1160
1161         dev_dbg(trf->dev, "Unsupported interface\n");
1162
1163         return -EINVAL;
1164 }
1165
1166 static int trf7970a_tg_listen(struct nfc_digital_dev *ddev,
1167                 u16 timeout, nfc_digital_cmd_complete_t cb, void *arg)
1168 {
1169         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1170
1171         dev_dbg(trf->dev, "Unsupported interface\n");
1172
1173         return -EINVAL;
1174 }
1175
1176 static int trf7970a_tg_listen_mdaa(struct nfc_digital_dev *ddev,
1177                 struct digital_tg_mdaa_params *mdaa_params,
1178                 u16 timeout, nfc_digital_cmd_complete_t cb, void *arg)
1179 {
1180         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1181
1182         dev_dbg(trf->dev, "Unsupported interface\n");
1183
1184         return -EINVAL;
1185 }
1186
1187 static void trf7970a_abort_cmd(struct nfc_digital_dev *ddev)
1188 {
1189         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1190
1191         dev_dbg(trf->dev, "Abort process initiated\n");
1192
1193         mutex_lock(&trf->lock);
1194         trf->aborting = true;
1195         mutex_unlock(&trf->lock);
1196 }
1197
1198 static struct nfc_digital_ops trf7970a_nfc_ops = {
1199         .in_configure_hw        = trf7970a_in_configure_hw,
1200         .in_send_cmd            = trf7970a_in_send_cmd,
1201         .tg_configure_hw        = trf7970a_tg_configure_hw,
1202         .tg_send_cmd            = trf7970a_tg_send_cmd,
1203         .tg_listen              = trf7970a_tg_listen,
1204         .tg_listen_mdaa         = trf7970a_tg_listen_mdaa,
1205         .switch_rf              = trf7970a_switch_rf,
1206         .abort_cmd              = trf7970a_abort_cmd,
1207 };
1208
1209 static int trf7970a_probe(struct spi_device *spi)
1210 {
1211         struct device_node *np = spi->dev.of_node;
1212         const struct spi_device_id *id = spi_get_device_id(spi);
1213         struct trf7970a *trf;
1214         int ret;
1215
1216         if (!np) {
1217                 dev_err(&spi->dev, "No Device Tree entry\n");
1218                 return -EINVAL;
1219         }
1220
1221         trf = devm_kzalloc(&spi->dev, sizeof(*trf), GFP_KERNEL);
1222         if (!trf)
1223                 return -ENOMEM;
1224
1225         trf->state = TRF7970A_ST_OFF;
1226         trf->dev = &spi->dev;
1227         trf->spi = spi;
1228         trf->quirks = id->driver_data;
1229
1230         spi->mode = SPI_MODE_1;
1231         spi->bits_per_word = 8;
1232
1233         /* There are two enable pins - both must be present */
1234         trf->en_gpio = of_get_named_gpio(np, "ti,enable-gpios", 0);
1235         if (!gpio_is_valid(trf->en_gpio)) {
1236                 dev_err(trf->dev, "No EN GPIO property\n");
1237                 return trf->en_gpio;
1238         }
1239
1240         ret = devm_gpio_request_one(trf->dev, trf->en_gpio,
1241                         GPIOF_DIR_OUT | GPIOF_INIT_LOW, "EN");
1242         if (ret) {
1243                 dev_err(trf->dev, "Can't request EN GPIO: %d\n", ret);
1244                 return ret;
1245         }
1246
1247         trf->en2_gpio = of_get_named_gpio(np, "ti,enable-gpios", 1);
1248         if (!gpio_is_valid(trf->en2_gpio)) {
1249                 dev_err(trf->dev, "No EN2 GPIO property\n");
1250                 return trf->en2_gpio;
1251         }
1252
1253         ret = devm_gpio_request_one(trf->dev, trf->en2_gpio,
1254                         GPIOF_DIR_OUT | GPIOF_INIT_LOW, "EN2");
1255         if (ret) {
1256                 dev_err(trf->dev, "Can't request EN2 GPIO: %d\n", ret);
1257                 return ret;
1258         }
1259
1260         ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL,
1261                         trf7970a_irq, IRQF_TRIGGER_RISING | IRQF_ONESHOT,
1262                         "trf7970a", trf);
1263         if (ret) {
1264                 dev_err(trf->dev, "Can't request IRQ#%d: %d\n", spi->irq, ret);
1265                 return ret;
1266         }
1267
1268         mutex_init(&trf->lock);
1269         INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
1270
1271         trf->regulator = devm_regulator_get(&spi->dev, "vin");
1272         if (IS_ERR(trf->regulator)) {
1273                 ret = PTR_ERR(trf->regulator);
1274                 dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret);
1275                 goto err_destroy_lock;
1276         }
1277
1278         ret = regulator_enable(trf->regulator);
1279         if (ret) {
1280                 dev_err(trf->dev, "Can't enable VIN: %d\n", ret);
1281                 goto err_destroy_lock;
1282         }
1283
1284         trf->powering_up = true;
1285
1286         trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,
1287                         TRF7970A_SUPPORTED_PROTOCOLS,
1288                         NFC_DIGITAL_DRV_CAPS_IN_CRC, TRF7970A_TX_SKB_HEADROOM,
1289                         0);
1290         if (!trf->ddev) {
1291                 dev_err(trf->dev, "Can't allocate NFC digital device\n");
1292                 ret = -ENOMEM;
1293                 goto err_disable_regulator;
1294         }
1295
1296         nfc_digital_set_parent_dev(trf->ddev, trf->dev);
1297         nfc_digital_set_drvdata(trf->ddev, trf);
1298         spi_set_drvdata(spi, trf);
1299
1300         ret = nfc_digital_register_device(trf->ddev);
1301         if (ret) {
1302                 dev_err(trf->dev, "Can't register NFC digital device: %d\n",
1303                                 ret);
1304                 goto err_free_ddev;
1305         }
1306
1307         return 0;
1308
1309 err_free_ddev:
1310         nfc_digital_free_device(trf->ddev);
1311 err_disable_regulator:
1312         regulator_disable(trf->regulator);
1313 err_destroy_lock:
1314         mutex_destroy(&trf->lock);
1315         return ret;
1316 }
1317
1318 static int trf7970a_remove(struct spi_device *spi)
1319 {
1320         struct trf7970a *trf = spi_get_drvdata(spi);
1321
1322         mutex_lock(&trf->lock);
1323
1324         trf7970a_switch_rf_off(trf);
1325         trf7970a_init(trf);
1326
1327         switch (trf->state) {
1328         case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1329         case TRF7970A_ST_WAIT_FOR_RX_DATA:
1330         case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1331         case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1332                 trf7970a_send_err_upstream(trf, -ECANCELED);
1333                 break;
1334         default:
1335                 break;
1336         }
1337
1338         mutex_unlock(&trf->lock);
1339
1340         nfc_digital_unregister_device(trf->ddev);
1341         nfc_digital_free_device(trf->ddev);
1342
1343         regulator_disable(trf->regulator);
1344
1345         mutex_destroy(&trf->lock);
1346
1347         return 0;
1348 }
1349
1350 static const struct spi_device_id trf7970a_id_table[] = {
1351         { "trf7970a", TRF7970A_QUIRK_IRQ_STATUS_READ_ERRATA },
1352         { }
1353 };
1354 MODULE_DEVICE_TABLE(spi, trf7970a_id_table);
1355
1356 static struct spi_driver trf7970a_spi_driver = {
1357         .probe          = trf7970a_probe,
1358         .remove         = trf7970a_remove,
1359         .id_table       = trf7970a_id_table,
1360         .driver         = {
1361                 .name   = "trf7970a",
1362                 .owner  = THIS_MODULE,
1363         },
1364 };
1365
1366 module_spi_driver(trf7970a_spi_driver);
1367
1368 MODULE_AUTHOR("Mark A. Greer <mgreer@animalcreek.com>");
1369 MODULE_LICENSE("GPL v2");
1370 MODULE_DESCRIPTION("TI trf7970a RFID/NFC Transceiver Driver");