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.
  40  *
  41  * Timeouts are implemented using the delayed workqueue kernel facility.
  42  * Timeouts are required so things don't hang when there is no response
  43  * from the trf7970a (or tag).  Using this mechanism creates a race with
  44  * interrupts, however.  That is, an interrupt and a timeout could occur
  45  * closely enough together that one is blocked by the mutex while the other
  46  * executes.  When the timeout handler executes first and blocks the
  47  * interrupt handler, it will eventually set the state to IDLE so the
  48  * interrupt handler will check the state and exit with no harm done.
  49  * When the interrupt handler executes first and blocks the timeout handler,
  50  * the cancel_delayed_work() call will know that it didn't cancel the
  51  * work item (i.e., timeout) and will return zero.  That return code is
  52  * used by the timer handler to indicate that it should ignore the timeout
  53  * once its unblocked.
  54  *
  55  * Aborting an active command isn't as simple as it seems because the only
  56  * way to abort a command that's already been sent to the tag is so turn
  57  * off power to the tag.  If we do that, though, we'd have to go through
  58  * the entire anticollision procedure again but the digital layer doesn't
  59  * support that.  So, if an abort is received before trf7970a_in_send_cmd()
  60  * has sent the command to the tag, it simply returns -ECANCELED.  If the
  61  * command has already been sent to the tag, then the driver continues
  62  * normally and recieves the response data (or error) but just before
  63  * sending the data upstream, it frees the rx_skb and sends -ECANCELED
  64  * upstream instead.  If the command failed, that error will be sent
  65  * upstream.
  66  *
  67  * When recieving data from a tag and the interrupt status register has
  68  * only the SRX bit set, it means that all of the data has been received
  69  * (once what's in the fifo has been read).  However, depending on timing
  70  * an interrupt status with only the SRX bit set may not be recived.  In
  71  * those cases, the timeout mechanism is used to wait 20 ms in case more
  72  * data arrives.  After 20 ms, it is assumed that all of the data has been
  73  * received and the accumulated rx data is sent upstream.  The
  74  * 'TRF7970A_ST_WAIT_FOR_RX_DATA_CONT' state is used for this purpose
  75  * (i.e., it indicates that some data has been received but we're not sure
  76  * if there is more coming so a timeout in this state means all data has
  77  * been received and there isn't an error).  The delay is 20 ms since delays
  78  * of ~16 ms have been observed during testing.
  79  *
  80  * Type 2 write and sector select commands respond with a 4-bit ACK or NACK.
  81  * Having only 4 bits in the FIFO won't normally generate an interrupt so
  82  * driver enables the '4_bit_RX' bit of the Special Functions register 1
  83  * to cause an interrupt in that case.  Leaving that bit for a read command
  84  * messes up the data returned so it is only enabled when the framing is
  85  * 'NFC_DIGITAL_FRAMING_NFCA_T2T' and the command is not a read command.
  86  * Unfortunately, that means that the driver has to peek into tx frames
  87  * when the framing is 'NFC_DIGITAL_FRAMING_NFCA_T2T'.  This is done by
  88  * the trf7970a_per_cmd_config() routine.
  89  *
  90  * ISO/IEC 15693 frames specify whether to use single or double sub-carrier
  91  * frequencies and whether to use low or high data rates in the flags byte
  92  * of the frame.  This means that the driver has to peek at all 15693 frames
  93  * to determine what speed to set the communication to.  In addition, write
  94  * and lock commands use the OPTION flag to indicate that an EOF must be
  95  * sent to the tag before it will send its response.  So the driver has to
  96  * examine all frames for that reason too.
  97  *
  98  * It is unclear how long to wait before sending the EOF.  According to the
  99  * Note under Table 1-1 in section 1.6 of
 100  * http://www.ti.com/lit/ug/scbu011/scbu011.pdf, that wait should be at least
 101  * 10 ms for TI Tag-it HF-I tags; however testing has shown that is not long
 102  * enough.  For this reason, the driver waits 20 ms which seems to work
 103  * reliably.
 104  */
 105
 106 #define TRF7970A_SUPPORTED_PROTOCOLS \
 107                 (NFC_PROTO_MIFARE_MASK | NFC_PROTO_ISO14443_MASK |      \
 108                  NFC_PROTO_ISO14443_B_MASK | NFC_PROTO_FELICA_MASK | \
 109                  NFC_PROTO_ISO15693_MASK)
 110
 111 #define TRF7970A_AUTOSUSPEND_DELAY              30000 /* 30 seconds */
 112
 113 /* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
 114  * on what the current framing is, the address of the TX length byte 1
 115  * register (0x1d), and the 2 byte length of the data to be transmitted.
 116  * That totals 5 bytes.
 117  */
 118 #define TRF7970A_TX_SKB_HEADROOM                5
 119
 120 #define TRF7970A_RX_SKB_ALLOC_SIZE              256
 121
 122 #define TRF7970A_FIFO_SIZE                      128
 123
 124 /* TX length is 3 nibbles long ==> 4KB - 1 bytes max */
 125 #define TRF7970A_TX_MAX                         (4096 - 1)
 126
 127 #define TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT       20
 128 #define TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT    3
 129 #define TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF     20
 130
 131 /* Quirks */
 132 /* Erratum: When reading IRQ Status register on trf7970a, we must issue a
 133  * read continuous command for IRQ Status and Collision Position registers.
 134  */
 135 #define TRF7970A_QUIRK_IRQ_STATUS_READ_ERRATA   BIT(0)
 136
 137 /* Direct commands */
 138 #define TRF7970A_CMD_IDLE                       0x00
 139 #define TRF7970A_CMD_SOFT_INIT                  0x03
 140 #define TRF7970A_CMD_RF_COLLISION               0x04
 141 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_N    0x05
 142 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_0    0x06
 143 #define TRF7970A_CMD_FIFO_RESET                 0x0f
 144 #define TRF7970A_CMD_TRANSMIT_NO_CRC            0x10
 145 #define TRF7970A_CMD_TRANSMIT                   0x11
 146 #define TRF7970A_CMD_DELAY_TRANSMIT_NO_CRC      0x12
 147 #define TRF7970A_CMD_DELAY_TRANSMIT             0x13
 148 #define TRF7970A_CMD_EOF                        0x14
 149 #define TRF7970A_CMD_CLOSE_SLOT                 0x15
 150 #define TRF7970A_CMD_BLOCK_RX                   0x16
 151 #define TRF7970A_CMD_ENABLE_RX                  0x17
 152 #define TRF7970A_CMD_TEST_EXT_RF                0x18
 153 #define TRF7970A_CMD_TEST_INT_RF                0x19
 154 #define TRF7970A_CMD_RX_GAIN_ADJUST             0x1a
 155
 156 /* Bits determining whether its a direct command or register R/W,
 157  * whether to use a continuous SPI transaction or not, and the actual
 158  * direct cmd opcode or regster address.
 159  */
 160 #define TRF7970A_CMD_BIT_CTRL                   BIT(7)
 161 #define TRF7970A_CMD_BIT_RW                     BIT(6)
 162 #define TRF7970A_CMD_BIT_CONTINUOUS             BIT(5)
 163 #define TRF7970A_CMD_BIT_OPCODE(opcode)         ((opcode) & 0x1f)
 164
 165 /* Registers addresses */
 166 #define TRF7970A_CHIP_STATUS_CTRL               0x00
 167 #define TRF7970A_ISO_CTRL                       0x01
 168 #define TRF7970A_ISO14443B_TX_OPTIONS           0x02
 169 #define TRF7970A_ISO14443A_HIGH_BITRATE_OPTIONS 0x03
 170 #define TRF7970A_TX_TIMER_SETTING_H_BYTE        0x04
 171 #define TRF7970A_TX_TIMER_SETTING_L_BYTE        0x05
 172 #define TRF7970A_TX_PULSE_LENGTH_CTRL           0x06
 173 #define TRF7970A_RX_NO_RESPONSE_WAIT            0x07
 174 #define TRF7970A_RX_WAIT_TIME                   0x08
 175 #define TRF7970A_MODULATOR_SYS_CLK_CTRL         0x09
 176 #define TRF7970A_RX_SPECIAL_SETTINGS            0x0a
 177 #define TRF7970A_REG_IO_CTRL                    0x0b
 178 #define TRF7970A_IRQ_STATUS                     0x0c
 179 #define TRF7970A_COLLISION_IRQ_MASK             0x0d
 180 #define TRF7970A_COLLISION_POSITION             0x0e
 181 #define TRF7970A_RSSI_OSC_STATUS                0x0f
 182 #define TRF7970A_SPECIAL_FCN_REG1               0x10
 183 #define TRF7970A_SPECIAL_FCN_REG2               0x11
 184 #define TRF7970A_RAM1                           0x12
 185 #define TRF7970A_RAM2                           0x13
 186 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS      0x14
 187 #define TRF7970A_NFC_LOW_FIELD_LEVEL            0x16
 188 #define TRF7970A_NFCID1                         0x17
 189 #define TRF7970A_NFC_TARGET_LEVEL               0x18
 190 #define TRF79070A_NFC_TARGET_PROTOCOL           0x19
 191 #define TRF7970A_TEST_REGISTER1                 0x1a
 192 #define TRF7970A_TEST_REGISTER2                 0x1b
 193 #define TRF7970A_FIFO_STATUS                    0x1c
 194 #define TRF7970A_TX_LENGTH_BYTE1                0x1d
 195 #define TRF7970A_TX_LENGTH_BYTE2                0x1e
 196 #define TRF7970A_FIFO_IO_REGISTER               0x1f
 197
 198 /* Chip Status Control Register Bits */
 199 #define TRF7970A_CHIP_STATUS_VRS5_3             BIT(0)
 200 #define TRF7970A_CHIP_STATUS_REC_ON             BIT(1)
 201 #define TRF7970A_CHIP_STATUS_AGC_ON             BIT(2)
 202 #define TRF7970A_CHIP_STATUS_PM_ON              BIT(3)
 203 #define TRF7970A_CHIP_STATUS_RF_PWR             BIT(4)
 204 #define TRF7970A_CHIP_STATUS_RF_ON              BIT(5)
 205 #define TRF7970A_CHIP_STATUS_DIRECT             BIT(6)
 206 #define TRF7970A_CHIP_STATUS_STBY               BIT(7)
 207
 208 /* ISO Control Register Bits */
 209 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_662    0x00
 210 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_662  0x01
 211 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648   0x02
 212 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_2648 0x03
 213 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a   0x04
 214 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_667  0x05
 215 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669   0x06
 216 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_2669 0x07
 217 #define TRF7970A_ISO_CTRL_14443A_106            0x08
 218 #define TRF7970A_ISO_CTRL_14443A_212            0x09
 219 #define TRF7970A_ISO_CTRL_14443A_424            0x0a
 220 #define TRF7970A_ISO_CTRL_14443A_848            0x0b
 221 #define TRF7970A_ISO_CTRL_14443B_106            0x0c
 222 #define TRF7970A_ISO_CTRL_14443B_212            0x0d
 223 #define TRF7970A_ISO_CTRL_14443B_424            0x0e
 224 #define TRF7970A_ISO_CTRL_14443B_848            0x0f
 225 #define TRF7970A_ISO_CTRL_FELICA_212            0x1a
 226 #define TRF7970A_ISO_CTRL_FELICA_424            0x1b
 227 #define TRF7970A_ISO_CTRL_RFID                  BIT(5)
 228 #define TRF7970A_ISO_CTRL_DIR_MODE              BIT(6)
 229 #define TRF7970A_ISO_CTRL_RX_CRC_N              BIT(7)  /* true == No CRC */
 230
 231 #define TRF7970A_ISO_CTRL_RFID_SPEED_MASK       0x1f
 232
 233 /* Modulator and SYS_CLK Control Register Bits */
 234 #define TRF7970A_MODULATOR_DEPTH(n)             ((n) & 0x7)
 235 #define TRF7970A_MODULATOR_DEPTH_ASK10          (TRF7970A_MODULATOR_DEPTH(0))
 236 #define TRF7970A_MODULATOR_DEPTH_OOK            (TRF7970A_MODULATOR_DEPTH(1))
 237 #define TRF7970A_MODULATOR_DEPTH_ASK7           (TRF7970A_MODULATOR_DEPTH(2))
 238 #define TRF7970A_MODULATOR_DEPTH_ASK8_5         (TRF7970A_MODULATOR_DEPTH(3))
 239 #define TRF7970A_MODULATOR_DEPTH_ASK13          (TRF7970A_MODULATOR_DEPTH(4))
 240 #define TRF7970A_MODULATOR_DEPTH_ASK16          (TRF7970A_MODULATOR_DEPTH(5))
 241 #define TRF7970A_MODULATOR_DEPTH_ASK22          (TRF7970A_MODULATOR_DEPTH(6))
 242 #define TRF7970A_MODULATOR_DEPTH_ASK30          (TRF7970A_MODULATOR_DEPTH(7))
 243 #define TRF7970A_MODULATOR_EN_ANA               BIT(3)
 244 #define TRF7970A_MODULATOR_CLK(n)               (((n) & 0x3) << 4)
 245 #define TRF7970A_MODULATOR_CLK_DISABLED         (TRF7970A_MODULATOR_CLK(0))
 246 #define TRF7970A_MODULATOR_CLK_3_6              (TRF7970A_MODULATOR_CLK(1))
 247 #define TRF7970A_MODULATOR_CLK_6_13             (TRF7970A_MODULATOR_CLK(2))
 248 #define TRF7970A_MODULATOR_CLK_13_27            (TRF7970A_MODULATOR_CLK(3))
 249 #define TRF7970A_MODULATOR_EN_OOK               BIT(6)
 250 #define TRF7970A_MODULATOR_27MHZ                BIT(7)
 251
 252 /* IRQ Status Register Bits */
 253 #define TRF7970A_IRQ_STATUS_NORESP              BIT(0) /* ISO15693 only */
 254 #define TRF7970A_IRQ_STATUS_COL                 BIT(1)
 255 #define TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR   BIT(2)
 256 #define TRF7970A_IRQ_STATUS_PARITY_ERROR        BIT(3)
 257 #define TRF7970A_IRQ_STATUS_CRC_ERROR           BIT(4)
 258 #define TRF7970A_IRQ_STATUS_FIFO                BIT(5)
 259 #define TRF7970A_IRQ_STATUS_SRX                 BIT(6)
 260 #define TRF7970A_IRQ_STATUS_TX                  BIT(7)
 261
 262 #define TRF7970A_IRQ_STATUS_ERROR                               \
 263                 (TRF7970A_IRQ_STATUS_COL |                      \
 264                  TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR |        \
 265                  TRF7970A_IRQ_STATUS_PARITY_ERROR |             \
 266                  TRF7970A_IRQ_STATUS_CRC_ERROR)
 267
 268 #define TRF7970A_SPECIAL_FCN_REG1_COL_7_6               BIT(0)
 269 #define TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL           BIT(1)
 270 #define TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX              BIT(2)
 271 #define TRF7970A_SPECIAL_FCN_REG1_SP_DIR_MODE           BIT(3)
 272 #define TRF7970A_SPECIAL_FCN_REG1_NEXT_SLOT_37US        BIT(4)
 273 #define TRF7970A_SPECIAL_FCN_REG1_PAR43                 BIT(5)
 274
 275 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_124      (0x0 << 2)
 276 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_120      (0x1 << 2)
 277 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_112      (0x2 << 2)
 278 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96       (0x3 << 2)
 279 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_4        0x0
 280 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_8        0x1
 281 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_16       0x2
 282 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32       0x3
 283
 284 #define TRF7970A_FIFO_STATUS_OVERFLOW           BIT(7)
 285
 286 /* NFC (ISO/IEC 14443A) Type 2 Tag commands */
 287 #define NFC_T2T_CMD_READ                        0x30
 288
 289 /* ISO 15693 commands codes */
 290 #define ISO15693_CMD_INVENTORY                  0x01
 291 #define ISO15693_CMD_READ_SINGLE_BLOCK          0x20
 292 #define ISO15693_CMD_WRITE_SINGLE_BLOCK         0x21
 293 #define ISO15693_CMD_LOCK_BLOCK                 0x22
 294 #define ISO15693_CMD_READ_MULTIPLE_BLOCK        0x23
 295 #define ISO15693_CMD_WRITE_MULTIPLE_BLOCK       0x24
 296 #define ISO15693_CMD_SELECT                     0x25
 297 #define ISO15693_CMD_RESET_TO_READY             0x26
 298 #define ISO15693_CMD_WRITE_AFI                  0x27
 299 #define ISO15693_CMD_LOCK_AFI                   0x28
 300 #define ISO15693_CMD_WRITE_DSFID                0x29
 301 #define ISO15693_CMD_LOCK_DSFID                 0x2a
 302 #define ISO15693_CMD_GET_SYSTEM_INFO            0x2b
 303 #define ISO15693_CMD_GET_MULTIPLE_BLOCK_SECURITY_STATUS 0x2c
 304
 305 /* ISO 15693 request and response flags */
 306 #define ISO15693_REQ_FLAG_SUB_CARRIER           BIT(0)
 307 #define ISO15693_REQ_FLAG_DATA_RATE             BIT(1)
 308 #define ISO15693_REQ_FLAG_INVENTORY             BIT(2)
 309 #define ISO15693_REQ_FLAG_PROTOCOL_EXT          BIT(3)
 310 #define ISO15693_REQ_FLAG_SELECT                BIT(4)
 311 #define ISO15693_REQ_FLAG_AFI                   BIT(4)
 312 #define ISO15693_REQ_FLAG_ADDRESS               BIT(5)
 313 #define ISO15693_REQ_FLAG_NB_SLOTS              BIT(5)
 314 #define ISO15693_REQ_FLAG_OPTION                BIT(6)
 315
 316 #define ISO15693_REQ_FLAG_SPEED_MASK \
 317                 (ISO15693_REQ_FLAG_SUB_CARRIER | ISO15693_REQ_FLAG_DATA_RATE)
 318
 319 enum trf7970a_state {
 320         TRF7970A_ST_OFF,
 321         TRF7970A_ST_IDLE,
 322         TRF7970A_ST_IDLE_RX_BLOCKED,
 323         TRF7970A_ST_WAIT_FOR_TX_FIFO,
 324         TRF7970A_ST_WAIT_FOR_RX_DATA,
 325         TRF7970A_ST_WAIT_FOR_RX_DATA_CONT,
 326         TRF7970A_ST_WAIT_TO_ISSUE_EOF,
 327         TRF7970A_ST_MAX
 328 };
 329
 330 struct trf7970a {
 331         enum trf7970a_state             state;
 332         struct device                   *dev;
 333         struct spi_device               *spi;
 334         struct regulator                *regulator;
 335         struct nfc_digital_dev          *ddev;
 336         u32                             quirks;
 337         bool                            aborting;
 338         struct sk_buff                  *tx_skb;
 339         struct sk_buff                  *rx_skb;
 340         nfc_digital_cmd_complete_t      cb;
 341         void                            *cb_arg;
 342         u8                              chip_status_ctrl;
 343         u8                              iso_ctrl;
 344         u8                              iso_ctrl_tech;
 345         u8                              modulator_sys_clk_ctrl;
 346         u8                              special_fcn_reg1;
 347         int                             technology;
 348         int                             framing;
 349         u8                              tx_cmd;
 350         bool                            issue_eof;
 351         int                             en2_gpio;
 352         int                             en_gpio;
 353         struct mutex                    lock;
 354         unsigned int                    timeout;
 355         bool                            ignore_timeout;
 356         struct delayed_work             timeout_work;
 357 };
 358
 359
 360 static int trf7970a_cmd(struct trf7970a *trf, u8 opcode)
 361 {
 362         u8 cmd = TRF7970A_CMD_BIT_CTRL | TRF7970A_CMD_BIT_OPCODE(opcode);
 363         int ret;
 364
 365         dev_dbg(trf->dev, "cmd: 0x%x\n", cmd);
 366
 367         ret = spi_write(trf->spi, &cmd, 1);
 368         if (ret)
 369                 dev_err(trf->dev, "%s - cmd: 0x%x, ret: %d\n", __func__, cmd,
 370                                 ret);
 371         return ret;
 372 }
 373
 374 static int trf7970a_read(struct trf7970a *trf, u8 reg, u8 *val)
 375 {
 376         u8 addr = TRF7970A_CMD_BIT_RW | reg;
 377         int ret;
 378
 379         ret = spi_write_then_read(trf->spi, &addr, 1, val, 1);
 380         if (ret)
 381                 dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
 382                                 ret);
 383
 384         dev_dbg(trf->dev, "read(0x%x): 0x%x\n", addr, *val);
 385
 386         return ret;
 387 }
 388
 389 static int trf7970a_read_cont(struct trf7970a *trf, u8 reg,
 390                 u8 *buf, size_t len)
 391 {
 392         u8 addr = reg | TRF7970A_CMD_BIT_RW | TRF7970A_CMD_BIT_CONTINUOUS;
 393         int ret;
 394
 395         dev_dbg(trf->dev, "read_cont(0x%x, %zd)\n", addr, len);
 396
 397         ret = spi_write_then_read(trf->spi, &addr, 1, buf, len);
 398         if (ret)
 399                 dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
 400                                 ret);
 401         return ret;
 402 }
 403
 404 static int trf7970a_write(struct trf7970a *trf, u8 reg, u8 val)
 405 {
 406         u8 buf[2] = { reg, val };
 407         int ret;
 408
 409         dev_dbg(trf->dev, "write(0x%x): 0x%x\n", reg, val);
 410
 411         ret = spi_write(trf->spi, buf, 2);
 412         if (ret)
 413                 dev_err(trf->dev, "%s - write: 0x%x 0x%x, ret: %d\n", __func__,
 414                                 buf[0], buf[1], ret);
 415
 416         return ret;
 417 }
 418
 419 static int trf7970a_read_irqstatus(struct trf7970a *trf, u8 *status)
 420 {
 421         int ret;
 422         u8 buf[2];
 423         u8 addr;
 424
 425         addr = TRF7970A_IRQ_STATUS | TRF7970A_CMD_BIT_RW;
 426
 427         if (trf->quirks & TRF7970A_QUIRK_IRQ_STATUS_READ_ERRATA) {
 428                 addr |= TRF7970A_CMD_BIT_CONTINUOUS;
 429                 ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
 430         } else {
 431                 ret = spi_write_then_read(trf->spi, &addr, 1, buf, 1);
 432         }
 433
 434         if (ret)
 435                 dev_err(trf->dev, "%s - irqstatus: Status read failed: %d\n",
 436                                 __func__, ret);
 437         else
 438                 *status = buf[0];
 439
 440         return ret;
 441 }
 442
 443 static void trf7970a_send_upstream(struct trf7970a *trf)
 444 {
 445         u8 rssi;
 446
 447         dev_kfree_skb_any(trf->tx_skb);
 448         trf->tx_skb = NULL;
 449
 450         if (trf->rx_skb && !IS_ERR(trf->rx_skb) && !trf->aborting)
 451                 print_hex_dump_debug("trf7970a rx data: ", DUMP_PREFIX_NONE,
 452                                 16, 1, trf->rx_skb->data, trf->rx_skb->len,
 453                                 false);
 454
 455         /* According to the manual it is "good form" to reset the fifo and
 456          * read the RSSI levels & oscillator status register here.  It doesn't
 457          * explain why.
 458          */
 459         trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 460         trf7970a_read(trf, TRF7970A_RSSI_OSC_STATUS, &rssi);
 461
 462         trf->state = TRF7970A_ST_IDLE;
 463
 464         if (trf->aborting) {
 465                 dev_dbg(trf->dev, "Abort process complete\n");
 466
 467                 if (!IS_ERR(trf->rx_skb)) {
 468                         kfree_skb(trf->rx_skb);
 469                         trf->rx_skb = ERR_PTR(-ECANCELED);
 470                 }
 471
 472                 trf->aborting = false;
 473         }
 474
 475         trf->cb(trf->ddev, trf->cb_arg, trf->rx_skb);
 476
 477         trf->rx_skb = NULL;
 478 }
 479
 480 static void trf7970a_send_err_upstream(struct trf7970a *trf, int errno)
 481 {
 482         dev_dbg(trf->dev, "Error - state: %d, errno: %d\n", trf->state, errno);
 483
 484         kfree_skb(trf->rx_skb);
 485         trf->rx_skb = ERR_PTR(errno);
 486
 487         trf7970a_send_upstream(trf);
 488 }
 489
 490 static int trf7970a_transmit(struct trf7970a *trf, struct sk_buff *skb,
 491                 unsigned int len)
 492 {
 493         unsigned int timeout;
 494         int ret;
 495
 496         print_hex_dump_debug("trf7970a tx data: ", DUMP_PREFIX_NONE,
 497                         16, 1, skb->data, len, false);
 498
 499         ret = spi_write(trf->spi, skb->data, len);
 500         if (ret) {
 501                 dev_err(trf->dev, "%s - Can't send tx data: %d\n", __func__,
 502                                 ret);
 503                 return ret;
 504         }
 505
 506         skb_pull(skb, len);
 507
 508         if (skb->len > 0) {
 509                 trf->state = TRF7970A_ST_WAIT_FOR_TX_FIFO;
 510                 timeout = TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT;
 511         } else {
 512                 if (trf->issue_eof) {
 513                         trf->state = TRF7970A_ST_WAIT_TO_ISSUE_EOF;
 514                         timeout = TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF;
 515                 } else {
 516                         trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
 517                         timeout = trf->timeout;
 518                 }
 519         }
 520
 521         dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n", timeout,
 522                         trf->state);
 523
 524         schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
 525
 526         return 0;
 527 }
 528
 529 static void trf7970a_fill_fifo(struct trf7970a *trf)
 530 {
 531         struct sk_buff *skb = trf->tx_skb;
 532         unsigned int len;
 533         int ret;
 534         u8 fifo_bytes;
 535
 536         ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
 537         if (ret) {
 538                 trf7970a_send_err_upstream(trf, ret);
 539                 return;
 540         }
 541
 542         dev_dbg(trf->dev, "Filling FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
 543
 544         if (fifo_bytes & TRF7970A_FIFO_STATUS_OVERFLOW) {
 545                 dev_err(trf->dev, "%s - fifo overflow: 0x%x\n", __func__,
 546                                 fifo_bytes);
 547                 trf7970a_send_err_upstream(trf, -EIO);
 548                 return;
 549         }
 550
 551         /* Calculate how much more data can be written to the fifo */
 552         len = TRF7970A_FIFO_SIZE - fifo_bytes;
 553         len = min(skb->len, len);
 554
 555         ret = trf7970a_transmit(trf, skb, len);
 556         if (ret)
 557                 trf7970a_send_err_upstream(trf, ret);
 558 }
 559
 560 static void trf7970a_drain_fifo(struct trf7970a *trf, u8 status)
 561 {
 562         struct sk_buff *skb = trf->rx_skb;
 563         int ret;
 564         u8 fifo_bytes;
 565
 566         if (status & TRF7970A_IRQ_STATUS_ERROR) {
 567                 trf7970a_send_err_upstream(trf, -EIO);
 568                 return;
 569         }
 570
 571         ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
 572         if (ret) {
 573                 trf7970a_send_err_upstream(trf, ret);
 574                 return;
 575         }
 576
 577         dev_dbg(trf->dev, "Draining FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
 578
 579         if (!fifo_bytes)
 580                 goto no_rx_data;
 581
 582         if (fifo_bytes & TRF7970A_FIFO_STATUS_OVERFLOW) {
 583                 dev_err(trf->dev, "%s - fifo overflow: 0x%x\n", __func__,
 584                                 fifo_bytes);
 585                 trf7970a_send_err_upstream(trf, -EIO);
 586                 return;
 587         }
 588
 589         if (fifo_bytes > skb_tailroom(skb)) {
 590                 skb = skb_copy_expand(skb, skb_headroom(skb),
 591                                 max_t(int, fifo_bytes,
 592                                         TRF7970A_RX_SKB_ALLOC_SIZE),
 593                                 GFP_KERNEL);
 594                 if (!skb) {
 595                         trf7970a_send_err_upstream(trf, -ENOMEM);
 596                         return;
 597                 }
 598
 599                 kfree_skb(trf->rx_skb);
 600                 trf->rx_skb = skb;
 601         }
 602
 603         ret = trf7970a_read_cont(trf, TRF7970A_FIFO_IO_REGISTER,
 604                         skb_put(skb, fifo_bytes), fifo_bytes);
 605         if (ret) {
 606                 trf7970a_send_err_upstream(trf, ret);
 607                 return;
 608         }
 609
 610         /* If received Type 2 ACK/NACK, shift right 4 bits and pass up */
 611         if ((trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T) && (skb->len == 1) &&
 612                         (trf->special_fcn_reg1 ==
 613                                  TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX)) {
 614                 skb->data[0] >>= 4;
 615                 status = TRF7970A_IRQ_STATUS_SRX;
 616         } else {
 617                 trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA_CONT;
 618         }
 619
 620 no_rx_data:
 621         if (status == TRF7970A_IRQ_STATUS_SRX) { /* Receive complete */
 622                 trf7970a_send_upstream(trf);
 623                 return;
 624         }
 625
 626         dev_dbg(trf->dev, "Setting timeout for %d ms\n",
 627                         TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT);
 628
 629         schedule_delayed_work(&trf->timeout_work,
 630                         msecs_to_jiffies(TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT));
 631 }
 632
 633 static irqreturn_t trf7970a_irq(int irq, void *dev_id)
 634 {
 635         struct trf7970a *trf = dev_id;
 636         int ret;
 637         u8 status;
 638
 639         mutex_lock(&trf->lock);
 640
 641         if (trf->state == TRF7970A_ST_OFF) {
 642                 mutex_unlock(&trf->lock);
 643                 return IRQ_NONE;
 644         }
 645
 646         ret = trf7970a_read_irqstatus(trf, &status);
 647         if (ret) {
 648                 mutex_unlock(&trf->lock);
 649                 return IRQ_NONE;
 650         }
 651
 652         dev_dbg(trf->dev, "IRQ - state: %d, status: 0x%x\n", trf->state,
 653                         status);
 654
 655         if (!status) {
 656                 mutex_unlock(&trf->lock);
 657                 return IRQ_NONE;
 658         }
 659
 660         switch (trf->state) {
 661         case TRF7970A_ST_IDLE:
 662         case TRF7970A_ST_IDLE_RX_BLOCKED:
 663                 /* If getting interrupts caused by RF noise, turn off the
 664                  * receiver to avoid unnecessary interrupts.  It will be
 665                  * turned back on in trf7970a_in_send_cmd() when the next
 666                  * command is issued.
 667                  */
 668                 if (status & TRF7970A_IRQ_STATUS_ERROR) {
 669                         trf7970a_cmd(trf, TRF7970A_CMD_BLOCK_RX);
 670                         trf->state = TRF7970A_ST_IDLE_RX_BLOCKED;
 671                 }
 672
 673                 trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 674                 break;
 675         case TRF7970A_ST_WAIT_FOR_TX_FIFO:
 676                 if (status & TRF7970A_IRQ_STATUS_TX) {
 677                         trf->ignore_timeout =
 678                                 !cancel_delayed_work(&trf->timeout_work);
 679                         trf7970a_fill_fifo(trf);
 680                 } else {
 681                         trf7970a_send_err_upstream(trf, -EIO);
 682                 }
 683                 break;
 684         case TRF7970A_ST_WAIT_FOR_RX_DATA:
 685         case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
 686                 if (status & TRF7970A_IRQ_STATUS_SRX) {
 687                         trf->ignore_timeout =
 688                                 !cancel_delayed_work(&trf->timeout_work);
 689                         trf7970a_drain_fifo(trf, status);
 690                 } else if (status == TRF7970A_IRQ_STATUS_TX) {
 691                         trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 692                 } else {
 693                         trf7970a_send_err_upstream(trf, -EIO);
 694                 }
 695                 break;
 696         case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
 697                 if (status != TRF7970A_IRQ_STATUS_TX)
 698                         trf7970a_send_err_upstream(trf, -EIO);
 699                 break;
 700         default:
 701                 dev_err(trf->dev, "%s - Driver in invalid state: %d\n",
 702                                 __func__, trf->state);
 703         }
 704
 705         mutex_unlock(&trf->lock);
 706         return IRQ_HANDLED;
 707 }
 708
 709 static void trf7970a_issue_eof(struct trf7970a *trf)
 710 {
 711         int ret;
 712
 713         dev_dbg(trf->dev, "Issuing EOF\n");
 714
 715         ret = trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 716         if (ret)
 717                 trf7970a_send_err_upstream(trf, ret);
 718
 719         ret = trf7970a_cmd(trf, TRF7970A_CMD_EOF);
 720         if (ret)
 721                 trf7970a_send_err_upstream(trf, ret);
 722
 723         trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
 724
 725         dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n",
 726                         trf->timeout, trf->state);
 727
 728         schedule_delayed_work(&trf->timeout_work,
 729                         msecs_to_jiffies(trf->timeout));
 730 }
 731
 732 static void trf7970a_timeout_work_handler(struct work_struct *work)
 733 {
 734         struct trf7970a *trf = container_of(work, struct trf7970a,
 735                         timeout_work.work);
 736
 737         dev_dbg(trf->dev, "Timeout - state: %d, ignore_timeout: %d\n",
 738                         trf->state, trf->ignore_timeout);
 739
 740         mutex_lock(&trf->lock);
 741
 742         if (trf->ignore_timeout)
 743                 trf->ignore_timeout = false;
 744         else if (trf->state == TRF7970A_ST_WAIT_FOR_RX_DATA_CONT)
 745                 trf7970a_send_upstream(trf); /* No more rx data so send up */
 746         else if (trf->state == TRF7970A_ST_WAIT_TO_ISSUE_EOF)
 747                 trf7970a_issue_eof(trf);
 748         else
 749                 trf7970a_send_err_upstream(trf, -ETIMEDOUT);
 750
 751         mutex_unlock(&trf->lock);
 752 }
 753
 754 static int trf7970a_init(struct trf7970a *trf)
 755 {
 756         int ret;
 757
 758         dev_dbg(trf->dev, "Initializing device - state: %d\n", trf->state);
 759
 760         ret = trf7970a_cmd(trf, TRF7970A_CMD_SOFT_INIT);
 761         if (ret)
 762                 goto err_out;
 763
 764         ret = trf7970a_cmd(trf, TRF7970A_CMD_IDLE);
 765         if (ret)
 766                 goto err_out;
 767
 768         /* Must clear NFC Target Detection Level reg due to erratum */
 769         ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
 770         if (ret)
 771                 goto err_out;
 772
 773         ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS,
 774                         TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 |
 775                         TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32);
 776         if (ret)
 777                 goto err_out;
 778
 779         ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1, 0);
 780         if (ret)
 781                 goto err_out;
 782
 783         trf->special_fcn_reg1 = 0;
 784
 785         trf->iso_ctrl = 0xff;
 786         return 0;
 787
 788 err_out:
 789         dev_dbg(trf->dev, "Couldn't init device: %d\n", ret);
 790         return ret;
 791 }
 792
 793 static void trf7970a_switch_rf_off(struct trf7970a *trf)
 794 {
 795         dev_dbg(trf->dev, "Switching rf off\n");
 796
 797         trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
 798
 799         trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, trf->chip_status_ctrl);
 800
 801         trf->aborting = false;
 802         trf->state = TRF7970A_ST_OFF;
 803
 804         pm_runtime_mark_last_busy(trf->dev);
 805         pm_runtime_put_autosuspend(trf->dev);
 806 }
 807
 808 static void trf7970a_switch_rf_on(struct trf7970a *trf)
 809 {
 810         dev_dbg(trf->dev, "Switching rf on\n");
 811
 812         pm_runtime_get_sync(trf->dev);
 813
 814         trf->state = TRF7970A_ST_IDLE;
 815 }
 816
 817 static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on)
 818 {
 819         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
 820
 821         dev_dbg(trf->dev, "Switching RF - state: %d, on: %d\n", trf->state, on);
 822
 823         mutex_lock(&trf->lock);
 824
 825         if (on) {
 826                 switch (trf->state) {
 827                 case TRF7970A_ST_OFF:
 828                         trf7970a_switch_rf_on(trf);
 829                         break;
 830                 case TRF7970A_ST_IDLE:
 831                 case TRF7970A_ST_IDLE_RX_BLOCKED:
 832                         break;
 833                 default:
 834                         dev_err(trf->dev, "%s - Invalid request: %d %d\n",
 835                                         __func__, trf->state, on);
 836                         trf7970a_switch_rf_off(trf);
 837                 }
 838         } else {
 839                 switch (trf->state) {
 840                 case TRF7970A_ST_OFF:
 841                         break;
 842                 default:
 843                         dev_err(trf->dev, "%s - Invalid request: %d %d\n",
 844                                         __func__, trf->state, on);
 845                         /* FALLTHROUGH */
 846                 case TRF7970A_ST_IDLE:
 847                 case TRF7970A_ST_IDLE_RX_BLOCKED:
 848                         trf7970a_switch_rf_off(trf);
 849                 }
 850         }
 851
 852         mutex_unlock(&trf->lock);
 853         return 0;
 854 }
 855
 856 static int trf7970a_config_rf_tech(struct trf7970a *trf, int tech)
 857 {
 858         int ret = 0;
 859
 860         dev_dbg(trf->dev, "rf technology: %d\n", tech);
 861
 862         switch (tech) {
 863         case NFC_DIGITAL_RF_TECH_106A:
 864                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443A_106;
 865                 trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_OOK;
 866                 break;
 867         case NFC_DIGITAL_RF_TECH_106B:
 868                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443B_106;
 869                 trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10;
 870                 break;
 871         case NFC_DIGITAL_RF_TECH_212F:
 872                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_212;
 873                 trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10;
 874                 break;
 875         case NFC_DIGITAL_RF_TECH_424F:
 876                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_424;
 877                 trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10;
 878                 break;
 879         case NFC_DIGITAL_RF_TECH_ISO15693:
 880                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
 881                 trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_OOK;
 882                 break;
 883         default:
 884                 dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
 885                 return -EINVAL;
 886         }
 887
 888         trf->technology = tech;
 889
 890         return ret;
 891 }
 892
 893 static int trf7970a_config_framing(struct trf7970a *trf, int framing)
 894 {
 895         u8 iso_ctrl = trf->iso_ctrl_tech;
 896         int ret;
 897
 898         dev_dbg(trf->dev, "framing: %d\n", framing);
 899
 900         switch (framing) {
 901         case NFC_DIGITAL_FRAMING_NFCA_SHORT:
 902         case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
 903                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
 904                 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
 905                 break;
 906         case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
 907         case NFC_DIGITAL_FRAMING_NFCA_T4T:
 908         case NFC_DIGITAL_FRAMING_NFCB:
 909         case NFC_DIGITAL_FRAMING_NFCB_T4T:
 910         case NFC_DIGITAL_FRAMING_NFCF:
 911         case NFC_DIGITAL_FRAMING_NFCF_T3T:
 912         case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY:
 913         case NFC_DIGITAL_FRAMING_ISO15693_T5T:
 914                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
 915                 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                 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         if (iso_ctrl != trf->iso_ctrl) {
 929                 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
 930                 if (ret)
 931                         return ret;
 932
 933                 trf->iso_ctrl = iso_ctrl;
 934
 935                 ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
 936                                 trf->modulator_sys_clk_ctrl);
 937                 if (ret)
 938                         return ret;
 939         }
 940
 941         if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
 942                 ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
 943                                 trf->chip_status_ctrl |
 944                                         TRF7970A_CHIP_STATUS_RF_ON);
 945                 if (ret)
 946                         return ret;
 947
 948                 trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
 949
 950                 usleep_range(5000, 6000);
 951         }
 952
 953         return 0;
 954 }
 955
 956 static int trf7970a_in_configure_hw(struct nfc_digital_dev *ddev, int type,
 957                 int param)
 958 {
 959         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
 960         int ret;
 961
 962         dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
 963
 964         mutex_lock(&trf->lock);
 965
 966         if (trf->state == TRF7970A_ST_OFF)
 967                 trf7970a_switch_rf_on(trf);
 968
 969         switch (type) {
 970         case NFC_DIGITAL_CONFIG_RF_TECH:
 971                 ret = trf7970a_config_rf_tech(trf, param);
 972                 break;
 973         case NFC_DIGITAL_CONFIG_FRAMING:
 974                 ret = trf7970a_config_framing(trf, param);
 975                 break;
 976         default:
 977                 dev_dbg(trf->dev, "Unknown type: %d\n", type);
 978                 ret = -EINVAL;
 979         }
 980
 981         mutex_unlock(&trf->lock);
 982         return ret;
 983 }
 984
 985 static int trf7970a_is_iso15693_write_or_lock(u8 cmd)
 986 {
 987         switch (cmd) {
 988         case ISO15693_CMD_WRITE_SINGLE_BLOCK:
 989         case ISO15693_CMD_LOCK_BLOCK:
 990         case ISO15693_CMD_WRITE_MULTIPLE_BLOCK:
 991         case ISO15693_CMD_WRITE_AFI:
 992         case ISO15693_CMD_LOCK_AFI:
 993         case ISO15693_CMD_WRITE_DSFID:
 994         case ISO15693_CMD_LOCK_DSFID:
 995                 return 1;
 996                 break;
 997         default:
 998                 return 0;
 999         }
1000 }
1001
1002 static int trf7970a_per_cmd_config(struct trf7970a *trf, struct sk_buff *skb)
1003 {
1004         u8 *req = skb->data;
1005         u8 special_fcn_reg1, iso_ctrl;
1006         int ret;
1007
1008         trf->issue_eof = false;
1009
1010         /* When issuing Type 2 read command, make sure the '4_bit_RX' bit in
1011          * special functions register 1 is cleared; otherwise, its a write or
1012          * sector select command and '4_bit_RX' must be set.
1013          *
1014          * When issuing an ISO 15693 command, inspect the flags byte to see
1015          * what speed to use.  Also, remember if the OPTION flag is set on
1016          * a Type 5 write or lock command so the driver will know that it
1017          * has to send an EOF in order to get a response.
1018          */
1019         if ((trf->technology == NFC_DIGITAL_RF_TECH_106A) &&
1020                         (trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T)) {
1021                 if (req[0] == NFC_T2T_CMD_READ)
1022                         special_fcn_reg1 = 0;
1023                 else
1024                         special_fcn_reg1 = TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX;
1025
1026                 if (special_fcn_reg1 != trf->special_fcn_reg1) {
1027                         ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1,
1028                                         special_fcn_reg1);
1029                         if (ret)
1030                                 return ret;
1031
1032                         trf->special_fcn_reg1 = special_fcn_reg1;
1033                 }
1034         } else if (trf->technology == NFC_DIGITAL_RF_TECH_ISO15693) {
1035                 iso_ctrl = trf->iso_ctrl & ~TRF7970A_ISO_CTRL_RFID_SPEED_MASK;
1036
1037                 switch (req[0] & ISO15693_REQ_FLAG_SPEED_MASK) {
1038                 case 0x00:
1039                         iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_662;
1040                         break;
1041                 case ISO15693_REQ_FLAG_SUB_CARRIER:
1042                         iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a;
1043                         break;
1044                 case ISO15693_REQ_FLAG_DATA_RATE:
1045                         iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1046                         break;
1047                 case (ISO15693_REQ_FLAG_SUB_CARRIER |
1048                                 ISO15693_REQ_FLAG_DATA_RATE):
1049                         iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669;
1050                         break;
1051                 }
1052
1053                 if (iso_ctrl != trf->iso_ctrl) {
1054                         ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1055                         if (ret)
1056                                 return ret;
1057
1058                         trf->iso_ctrl = iso_ctrl;
1059                 }
1060
1061                 if ((trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) &&
1062                                 trf7970a_is_iso15693_write_or_lock(req[1]) &&
1063                                 (req[0] & ISO15693_REQ_FLAG_OPTION))
1064                         trf->issue_eof = true;
1065         }
1066
1067         return 0;
1068 }
1069
1070 static int trf7970a_in_send_cmd(struct nfc_digital_dev *ddev,
1071                 struct sk_buff *skb, u16 timeout,
1072                 nfc_digital_cmd_complete_t cb, void *arg)
1073 {
1074         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1075         char *prefix;
1076         unsigned int len;
1077         int ret;
1078
1079         dev_dbg(trf->dev, "New request - state: %d, timeout: %d ms, len: %d\n",
1080                         trf->state, timeout, skb->len);
1081
1082         if (skb->len > TRF7970A_TX_MAX)
1083                 return -EINVAL;
1084
1085         mutex_lock(&trf->lock);
1086
1087         if ((trf->state != TRF7970A_ST_IDLE) &&
1088                         (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1089                 dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1090                                 trf->state);
1091                 ret = -EIO;
1092                 goto out_err;
1093         }
1094
1095         if (trf->aborting) {
1096                 dev_dbg(trf->dev, "Abort process complete\n");
1097                 trf->aborting = false;
1098                 ret = -ECANCELED;
1099                 goto out_err;
1100         }
1101
1102         trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1103                         GFP_KERNEL);
1104         if (!trf->rx_skb) {
1105                 dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1106                 ret = -ENOMEM;
1107                 goto out_err;
1108         }
1109
1110         if (trf->state == TRF7970A_ST_IDLE_RX_BLOCKED) {
1111                 ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1112                 if (ret)
1113                         goto out_err;
1114
1115                 trf->state = TRF7970A_ST_IDLE;
1116         }
1117
1118         ret = trf7970a_per_cmd_config(trf, skb);
1119         if (ret)
1120                 goto out_err;
1121
1122         trf->ddev = ddev;
1123         trf->tx_skb = skb;
1124         trf->cb = cb;
1125         trf->cb_arg = arg;
1126         trf->timeout = timeout;
1127         trf->ignore_timeout = false;
1128
1129         len = skb->len;
1130         prefix = skb_push(skb, TRF7970A_TX_SKB_HEADROOM);
1131
1132         /* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
1133          * on what the current framing is, the address of the TX length byte 1
1134          * register (0x1d), and the 2 byte length of the data to be transmitted.
1135          */
1136         prefix[0] = TRF7970A_CMD_BIT_CTRL |
1137                         TRF7970A_CMD_BIT_OPCODE(TRF7970A_CMD_FIFO_RESET);
1138         prefix[1] = TRF7970A_CMD_BIT_CTRL |
1139                         TRF7970A_CMD_BIT_OPCODE(trf->tx_cmd);
1140         prefix[2] = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_TX_LENGTH_BYTE1;
1141
1142         if (trf->framing == NFC_DIGITAL_FRAMING_NFCA_SHORT) {
1143                 prefix[3] = 0x00;
1144                 prefix[4] = 0x0f; /* 7 bits */
1145         } else {
1146                 prefix[3] = (len & 0xf00) >> 4;
1147                 prefix[3] |= ((len & 0xf0) >> 4);
1148                 prefix[4] = ((len & 0x0f) << 4);
1149         }
1150
1151         len = min_t(int, skb->len, TRF7970A_FIFO_SIZE);
1152
1153         usleep_range(1000, 2000);
1154
1155         ret = trf7970a_transmit(trf, skb, len);
1156         if (ret) {
1157                 kfree_skb(trf->rx_skb);
1158                 trf->rx_skb = NULL;
1159         }
1160
1161 out_err:
1162         mutex_unlock(&trf->lock);
1163         return ret;
1164 }
1165
1166 static int trf7970a_tg_configure_hw(struct nfc_digital_dev *ddev,
1167                 int type, int param)
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_send_cmd(struct nfc_digital_dev *ddev,
1177                 struct sk_buff *skb, u16 timeout,
1178                 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 int trf7970a_tg_listen(struct nfc_digital_dev *ddev,
1188                 u16 timeout, nfc_digital_cmd_complete_t cb, void *arg)
1189 {
1190         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1191
1192         dev_dbg(trf->dev, "Unsupported interface\n");
1193
1194         return -EINVAL;
1195 }
1196
1197 static int trf7970a_tg_listen_mdaa(struct nfc_digital_dev *ddev,
1198                 struct digital_tg_mdaa_params *mdaa_params,
1199                 u16 timeout, nfc_digital_cmd_complete_t cb, void *arg)
1200 {
1201         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1202
1203         dev_dbg(trf->dev, "Unsupported interface\n");
1204
1205         return -EINVAL;
1206 }
1207
1208 static void trf7970a_abort_cmd(struct nfc_digital_dev *ddev)
1209 {
1210         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1211
1212         dev_dbg(trf->dev, "Abort process initiated\n");
1213
1214         mutex_lock(&trf->lock);
1215
1216         switch (trf->state) {
1217         case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1218         case TRF7970A_ST_WAIT_FOR_RX_DATA:
1219         case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1220         case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1221                 trf->aborting = true;
1222                 break;
1223         default:
1224                 break;
1225         }
1226
1227         mutex_unlock(&trf->lock);
1228 }
1229
1230 static struct nfc_digital_ops trf7970a_nfc_ops = {
1231         .in_configure_hw        = trf7970a_in_configure_hw,
1232         .in_send_cmd            = trf7970a_in_send_cmd,
1233         .tg_configure_hw        = trf7970a_tg_configure_hw,
1234         .tg_send_cmd            = trf7970a_tg_send_cmd,
1235         .tg_listen              = trf7970a_tg_listen,
1236         .tg_listen_mdaa         = trf7970a_tg_listen_mdaa,
1237         .switch_rf              = trf7970a_switch_rf,
1238         .abort_cmd              = trf7970a_abort_cmd,
1239 };
1240
1241 static int trf7970a_get_autosuspend_delay(struct device_node *np)
1242 {
1243         int autosuspend_delay, ret;
1244
1245         ret = of_property_read_u32(np, "autosuspend-delay", &autosuspend_delay);
1246         if (ret)
1247                 autosuspend_delay = TRF7970A_AUTOSUSPEND_DELAY;
1248
1249         of_node_put(np);
1250
1251         return autosuspend_delay;
1252 }
1253
1254 static int trf7970a_probe(struct spi_device *spi)
1255 {
1256         struct device_node *np = spi->dev.of_node;
1257         const struct spi_device_id *id = spi_get_device_id(spi);
1258         struct trf7970a *trf;
1259         int uvolts, autosuspend_delay, ret;
1260
1261         if (!np) {
1262                 dev_err(&spi->dev, "No Device Tree entry\n");
1263                 return -EINVAL;
1264         }
1265
1266         trf = devm_kzalloc(&spi->dev, sizeof(*trf), GFP_KERNEL);
1267         if (!trf)
1268                 return -ENOMEM;
1269
1270         trf->state = TRF7970A_ST_OFF;
1271         trf->dev = &spi->dev;
1272         trf->spi = spi;
1273         trf->quirks = id->driver_data;
1274
1275         spi->mode = SPI_MODE_1;
1276         spi->bits_per_word = 8;
1277
1278         /* There are two enable pins - both must be present */
1279         trf->en_gpio = of_get_named_gpio(np, "ti,enable-gpios", 0);
1280         if (!gpio_is_valid(trf->en_gpio)) {
1281                 dev_err(trf->dev, "No EN GPIO property\n");
1282                 return trf->en_gpio;
1283         }
1284
1285         ret = devm_gpio_request_one(trf->dev, trf->en_gpio,
1286                         GPIOF_DIR_OUT | GPIOF_INIT_LOW, "EN");
1287         if (ret) {
1288                 dev_err(trf->dev, "Can't request EN GPIO: %d\n", ret);
1289                 return ret;
1290         }
1291
1292         trf->en2_gpio = of_get_named_gpio(np, "ti,enable-gpios", 1);
1293         if (!gpio_is_valid(trf->en2_gpio)) {
1294                 dev_err(trf->dev, "No EN2 GPIO property\n");
1295                 return trf->en2_gpio;
1296         }
1297
1298         ret = devm_gpio_request_one(trf->dev, trf->en2_gpio,
1299                         GPIOF_DIR_OUT | GPIOF_INIT_LOW, "EN2");
1300         if (ret) {
1301                 dev_err(trf->dev, "Can't request EN2 GPIO: %d\n", ret);
1302                 return ret;
1303         }
1304
1305         ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL,
1306                         trf7970a_irq, IRQF_TRIGGER_RISING | IRQF_ONESHOT,
1307                         "trf7970a", trf);
1308         if (ret) {
1309                 dev_err(trf->dev, "Can't request IRQ#%d: %d\n", spi->irq, ret);
1310                 return ret;
1311         }
1312
1313         mutex_init(&trf->lock);
1314         INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
1315
1316         trf->regulator = devm_regulator_get(&spi->dev, "vin");
1317         if (IS_ERR(trf->regulator)) {
1318                 ret = PTR_ERR(trf->regulator);
1319                 dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret);
1320                 goto err_destroy_lock;
1321         }
1322
1323         ret = regulator_enable(trf->regulator);
1324         if (ret) {
1325                 dev_err(trf->dev, "Can't enable VIN: %d\n", ret);
1326                 goto err_destroy_lock;
1327         }
1328
1329         uvolts = regulator_get_voltage(trf->regulator);
1330
1331         if (uvolts > 4000000)
1332                 trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;
1333
1334         trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,
1335                         TRF7970A_SUPPORTED_PROTOCOLS,
1336                         NFC_DIGITAL_DRV_CAPS_IN_CRC, TRF7970A_TX_SKB_HEADROOM,
1337                         0);
1338         if (!trf->ddev) {
1339                 dev_err(trf->dev, "Can't allocate NFC digital device\n");
1340                 ret = -ENOMEM;
1341                 goto err_disable_regulator;
1342         }
1343
1344         nfc_digital_set_parent_dev(trf->ddev, trf->dev);
1345         nfc_digital_set_drvdata(trf->ddev, trf);
1346         spi_set_drvdata(spi, trf);
1347
1348         autosuspend_delay = trf7970a_get_autosuspend_delay(np);
1349
1350         pm_runtime_set_autosuspend_delay(trf->dev, autosuspend_delay);
1351         pm_runtime_use_autosuspend(trf->dev);
1352         pm_runtime_enable(trf->dev);
1353
1354         ret = nfc_digital_register_device(trf->ddev);
1355         if (ret) {
1356                 dev_err(trf->dev, "Can't register NFC digital device: %d\n",
1357                                 ret);
1358                 goto err_free_ddev;
1359         }
1360
1361         return 0;
1362
1363 err_free_ddev:
1364         pm_runtime_disable(trf->dev);
1365         nfc_digital_free_device(trf->ddev);
1366 err_disable_regulator:
1367         regulator_disable(trf->regulator);
1368 err_destroy_lock:
1369         mutex_destroy(&trf->lock);
1370         return ret;
1371 }
1372
1373 static int trf7970a_remove(struct spi_device *spi)
1374 {
1375         struct trf7970a *trf = spi_get_drvdata(spi);
1376
1377         mutex_lock(&trf->lock);
1378
1379         switch (trf->state) {
1380         case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1381         case TRF7970A_ST_WAIT_FOR_RX_DATA:
1382         case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1383         case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1384                 trf7970a_send_err_upstream(trf, -ECANCELED);
1385                 /* FALLTHROUGH */
1386         case TRF7970A_ST_IDLE:
1387         case TRF7970A_ST_IDLE_RX_BLOCKED:
1388                 pm_runtime_put_sync(trf->dev);
1389                 break;
1390         default:
1391                 break;
1392         }
1393
1394         mutex_unlock(&trf->lock);
1395
1396         pm_runtime_disable(trf->dev);
1397
1398         nfc_digital_unregister_device(trf->ddev);
1399         nfc_digital_free_device(trf->ddev);
1400
1401         regulator_disable(trf->regulator);
1402
1403         mutex_destroy(&trf->lock);
1404
1405         return 0;
1406 }
1407
1408 #ifdef CONFIG_PM_RUNTIME
1409 static int trf7970a_pm_runtime_suspend(struct device *dev)
1410 {
1411         struct spi_device *spi = container_of(dev, struct spi_device, dev);
1412         struct trf7970a *trf = spi_get_drvdata(spi);
1413         int ret;
1414
1415         dev_dbg(dev, "Runtime suspend\n");
1416
1417         if (trf->state != TRF7970A_ST_OFF) {
1418                 dev_dbg(dev, "Can't suspend - not in OFF state (%d)\n",
1419                                 trf->state);
1420                 return -EBUSY;
1421         }
1422
1423         gpio_set_value(trf->en_gpio, 0);
1424         gpio_set_value(trf->en2_gpio, 0);
1425
1426         ret = regulator_disable(trf->regulator);
1427         if (ret)
1428                 dev_err(dev, "%s - Can't disable VIN: %d\n", __func__, ret);
1429
1430         return ret;
1431 }
1432
1433 static int trf7970a_pm_runtime_resume(struct device *dev)
1434 {
1435         struct spi_device *spi = container_of(dev, struct spi_device, dev);
1436         struct trf7970a *trf = spi_get_drvdata(spi);
1437         int ret;
1438
1439         dev_dbg(dev, "Runtime resume\n");
1440
1441         ret = regulator_enable(trf->regulator);
1442         if (ret) {
1443                 dev_err(dev, "%s - Can't enable VIN: %d\n", __func__, ret);
1444                 return ret;
1445         }
1446
1447         usleep_range(5000, 6000);
1448
1449         gpio_set_value(trf->en2_gpio, 1);
1450         usleep_range(1000, 2000);
1451         gpio_set_value(trf->en_gpio, 1);
1452
1453         usleep_range(20000, 21000);
1454
1455         ret = trf7970a_init(trf);
1456         if (ret) {
1457                 dev_err(dev, "%s - Can't initialize: %d\n", __func__, ret);
1458                 return ret;
1459         }
1460
1461         pm_runtime_mark_last_busy(dev);
1462
1463         return 0;
1464 }
1465 #endif
1466
1467 static const struct dev_pm_ops trf7970a_pm_ops = {
1468         SET_RUNTIME_PM_OPS(trf7970a_pm_runtime_suspend,
1469                         trf7970a_pm_runtime_resume, NULL)
1470 };
1471
1472 static const struct spi_device_id trf7970a_id_table[] = {
1473         { "trf7970a", TRF7970A_QUIRK_IRQ_STATUS_READ_ERRATA },
1474         { }
1475 };
1476 MODULE_DEVICE_TABLE(spi, trf7970a_id_table);
1477
1478 static struct spi_driver trf7970a_spi_driver = {
1479         .probe          = trf7970a_probe,
1480         .remove         = trf7970a_remove,
1481         .id_table       = trf7970a_id_table,
1482         .driver         = {
1483                 .name   = "trf7970a",
1484                 .owner  = THIS_MODULE,
1485                 .pm     = &trf7970a_pm_ops,
1486         },
1487 };
1488
1489 module_spi_driver(trf7970a_spi_driver);
1490
1491 MODULE_AUTHOR("Mark A. Greer <mgreer@animalcreek.com>");
1492 MODULE_LICENSE("GPL v2");
1493 MODULE_DESCRIPTION("TI trf7970a RFID/NFC Transceiver Driver");