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/consumer.h>
  24 #include <linux/of.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.  There is a bug with the current
  39  * version of the trf7970a that requires that EN2 remain low no matter
  40  * what.  If it goes high, it will generate an RF field even when in
  41  * passive target mode.  TI has indicated that the chip will work okay
  42  * when EN2 is left low.  The 'en2-rf-quirk' device tree property
  43  * indicates that trf7970a currently being used has the erratum and
  44  * that EN2 must be kept low.
  45  *
  46  * Timeouts are implemented using the delayed workqueue kernel facility.
  47  * Timeouts are required so things don't hang when there is no response
  48  * from the trf7970a (or tag).  Using this mechanism creates a race with
  49  * interrupts, however.  That is, an interrupt and a timeout could occur
  50  * closely enough together that one is blocked by the mutex while the other
  51  * executes.  When the timeout handler executes first and blocks the
  52  * interrupt handler, it will eventually set the state to IDLE so the
  53  * interrupt handler will check the state and exit with no harm done.
  54  * When the interrupt handler executes first and blocks the timeout handler,
  55  * the cancel_delayed_work() call will know that it didn't cancel the
  56  * work item (i.e., timeout) and will return zero.  That return code is
  57  * used by the timer handler to indicate that it should ignore the timeout
  58  * once its unblocked.
  59  *
  60  * Aborting an active command isn't as simple as it seems because the only
  61  * way to abort a command that's already been sent to the tag is so turn
  62  * off power to the tag.  If we do that, though, we'd have to go through
  63  * the entire anticollision procedure again but the digital layer doesn't
  64  * support that.  So, if an abort is received before trf7970a_send_cmd()
  65  * has sent the command to the tag, it simply returns -ECANCELED.  If the
  66  * command has already been sent to the tag, then the driver continues
  67  * normally and recieves the response data (or error) but just before
  68  * sending the data upstream, it frees the rx_skb and sends -ECANCELED
  69  * upstream instead.  If the command failed, that error will be sent
  70  * upstream.
  71  *
  72  * When recieving data from a tag and the interrupt status register has
  73  * only the SRX bit set, it means that all of the data has been received
  74  * (once what's in the fifo has been read).  However, depending on timing
  75  * an interrupt status with only the SRX bit set may not be recived.  In
  76  * those cases, the timeout mechanism is used to wait 20 ms in case more
  77  * data arrives.  After 20 ms, it is assumed that all of the data has been
  78  * received and the accumulated rx data is sent upstream.  The
  79  * 'TRF7970A_ST_WAIT_FOR_RX_DATA_CONT' state is used for this purpose
  80  * (i.e., it indicates that some data has been received but we're not sure
  81  * if there is more coming so a timeout in this state means all data has
  82  * been received and there isn't an error).  The delay is 20 ms since delays
  83  * of ~16 ms have been observed during testing.
  84  *
  85  * When transmitting a frame larger than the FIFO size (127 bytes), the
  86  * driver will wait 20 ms for the FIFO to drain past the low-watermark
  87  * and generate an interrupt.  The low-watermark set to 32 bytes so the
  88  * interrupt should fire after 127 - 32 = 95 bytes have been sent.  At
  89  * the lowest possible bit rate (6.62 kbps for 15693), it will take up
  90  * to ~14.35 ms so 20 ms is used for the timeout.
  91  *
  92  * Type 2 write and sector select commands respond with a 4-bit ACK or NACK.
  93  * Having only 4 bits in the FIFO won't normally generate an interrupt so
  94  * driver enables the '4_bit_RX' bit of the Special Functions register 1
  95  * to cause an interrupt in that case.  Leaving that bit for a read command
  96  * messes up the data returned so it is only enabled when the framing is
  97  * 'NFC_DIGITAL_FRAMING_NFCA_T2T' and the command is not a read command.
  98  * Unfortunately, that means that the driver has to peek into tx frames
  99  * when the framing is 'NFC_DIGITAL_FRAMING_NFCA_T2T'.  This is done by
 100  * the trf7970a_per_cmd_config() routine.
 101  *
 102  * ISO/IEC 15693 frames specify whether to use single or double sub-carrier
 103  * frequencies and whether to use low or high data rates in the flags byte
 104  * of the frame.  This means that the driver has to peek at all 15693 frames
 105  * to determine what speed to set the communication to.  In addition, write
 106  * and lock commands use the OPTION flag to indicate that an EOF must be
 107  * sent to the tag before it will send its response.  So the driver has to
 108  * examine all frames for that reason too.
 109  *
 110  * It is unclear how long to wait before sending the EOF.  According to the
 111  * Note under Table 1-1 in section 1.6 of
 112  * http://www.ti.com/lit/ug/scbu011/scbu011.pdf, that wait should be at least
 113  * 10 ms for TI Tag-it HF-I tags; however testing has shown that is not long
 114  * enough so 20 ms is used.  So the timer is set to 40 ms - 20 ms to drain
 115  * up to 127 bytes in the FIFO at the lowest bit rate plus another 20 ms to
 116  * ensure the wait is long enough before sending the EOF.  This seems to work
 117  * reliably.
 118  */
 119
 120 #define TRF7970A_SUPPORTED_PROTOCOLS \
 121                 (NFC_PROTO_MIFARE_MASK | NFC_PROTO_ISO14443_MASK |      \
 122                  NFC_PROTO_ISO14443_B_MASK | NFC_PROTO_FELICA_MASK | \
 123                  NFC_PROTO_ISO15693_MASK | NFC_PROTO_NFC_DEP_MASK)
 124
 125 #define TRF7970A_AUTOSUSPEND_DELAY              30000   /* 30 seconds */
 126 #define TRF7970A_13MHZ_CLOCK_FREQUENCY          13560000
 127 #define TRF7970A_27MHZ_CLOCK_FREQUENCY          27120000
 128
 129 #define TRF7970A_RX_SKB_ALLOC_SIZE              256
 130
 131 #define TRF7970A_FIFO_SIZE                      127
 132
 133 /* TX length is 3 nibbles long ==> 4KB - 1 bytes max */
 134 #define TRF7970A_TX_MAX                         (4096 - 1)
 135
 136 #define TRF7970A_WAIT_FOR_TX_IRQ                20
 137 #define TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT       20
 138 #define TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT    20
 139 #define TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF     40
 140
 141 /* Guard times for various RF technologies (in us) */
 142 #define TRF7970A_GUARD_TIME_NFCA                5000
 143 #define TRF7970A_GUARD_TIME_NFCB                5000
 144 #define TRF7970A_GUARD_TIME_NFCF                20000
 145 #define TRF7970A_GUARD_TIME_15693               1000
 146
 147 /* Quirks */
 148 /* Erratum: When reading IRQ Status register on trf7970a, we must issue a
 149  * read continuous command for IRQ Status and Collision Position registers.
 150  */
 151 #define TRF7970A_QUIRK_IRQ_STATUS_READ          BIT(0)
 152 #define TRF7970A_QUIRK_EN2_MUST_STAY_LOW        BIT(1)
 153
 154 /* Direct commands */
 155 #define TRF7970A_CMD_IDLE                       0x00
 156 #define TRF7970A_CMD_SOFT_INIT                  0x03
 157 #define TRF7970A_CMD_RF_COLLISION               0x04
 158 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_N    0x05
 159 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_0    0x06
 160 #define TRF7970A_CMD_FIFO_RESET                 0x0f
 161 #define TRF7970A_CMD_TRANSMIT_NO_CRC            0x10
 162 #define TRF7970A_CMD_TRANSMIT                   0x11
 163 #define TRF7970A_CMD_DELAY_TRANSMIT_NO_CRC      0x12
 164 #define TRF7970A_CMD_DELAY_TRANSMIT             0x13
 165 #define TRF7970A_CMD_EOF                        0x14
 166 #define TRF7970A_CMD_CLOSE_SLOT                 0x15
 167 #define TRF7970A_CMD_BLOCK_RX                   0x16
 168 #define TRF7970A_CMD_ENABLE_RX                  0x17
 169 #define TRF7970A_CMD_TEST_INT_RF                0x18
 170 #define TRF7970A_CMD_TEST_EXT_RF                0x19
 171 #define TRF7970A_CMD_RX_GAIN_ADJUST             0x1a
 172
 173 /* Bits determining whether its a direct command or register R/W,
 174  * whether to use a continuous SPI transaction or not, and the actual
 175  * direct cmd opcode or regster address.
 176  */
 177 #define TRF7970A_CMD_BIT_CTRL                   BIT(7)
 178 #define TRF7970A_CMD_BIT_RW                     BIT(6)
 179 #define TRF7970A_CMD_BIT_CONTINUOUS             BIT(5)
 180 #define TRF7970A_CMD_BIT_OPCODE(opcode)         ((opcode) & 0x1f)
 181
 182 /* Registers addresses */
 183 #define TRF7970A_CHIP_STATUS_CTRL               0x00
 184 #define TRF7970A_ISO_CTRL                       0x01
 185 #define TRF7970A_ISO14443B_TX_OPTIONS           0x02
 186 #define TRF7970A_ISO14443A_HIGH_BITRATE_OPTIONS 0x03
 187 #define TRF7970A_TX_TIMER_SETTING_H_BYTE        0x04
 188 #define TRF7970A_TX_TIMER_SETTING_L_BYTE        0x05
 189 #define TRF7970A_TX_PULSE_LENGTH_CTRL           0x06
 190 #define TRF7970A_RX_NO_RESPONSE_WAIT            0x07
 191 #define TRF7970A_RX_WAIT_TIME                   0x08
 192 #define TRF7970A_MODULATOR_SYS_CLK_CTRL         0x09
 193 #define TRF7970A_RX_SPECIAL_SETTINGS            0x0a
 194 #define TRF7970A_REG_IO_CTRL                    0x0b
 195 #define TRF7970A_IRQ_STATUS                     0x0c
 196 #define TRF7970A_COLLISION_IRQ_MASK             0x0d
 197 #define TRF7970A_COLLISION_POSITION             0x0e
 198 #define TRF7970A_RSSI_OSC_STATUS                0x0f
 199 #define TRF7970A_SPECIAL_FCN_REG1               0x10
 200 #define TRF7970A_SPECIAL_FCN_REG2               0x11
 201 #define TRF7970A_RAM1                           0x12
 202 #define TRF7970A_RAM2                           0x13
 203 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS      0x14
 204 #define TRF7970A_NFC_LOW_FIELD_LEVEL            0x16
 205 #define TRF7970A_NFCID1                         0x17
 206 #define TRF7970A_NFC_TARGET_LEVEL               0x18
 207 #define TRF79070A_NFC_TARGET_PROTOCOL           0x19
 208 #define TRF7970A_TEST_REGISTER1                 0x1a
 209 #define TRF7970A_TEST_REGISTER2                 0x1b
 210 #define TRF7970A_FIFO_STATUS                    0x1c
 211 #define TRF7970A_TX_LENGTH_BYTE1                0x1d
 212 #define TRF7970A_TX_LENGTH_BYTE2                0x1e
 213 #define TRF7970A_FIFO_IO_REGISTER               0x1f
 214
 215 /* Chip Status Control Register Bits */
 216 #define TRF7970A_CHIP_STATUS_VRS5_3             BIT(0)
 217 #define TRF7970A_CHIP_STATUS_REC_ON             BIT(1)
 218 #define TRF7970A_CHIP_STATUS_AGC_ON             BIT(2)
 219 #define TRF7970A_CHIP_STATUS_PM_ON              BIT(3)
 220 #define TRF7970A_CHIP_STATUS_RF_PWR             BIT(4)
 221 #define TRF7970A_CHIP_STATUS_RF_ON              BIT(5)
 222 #define TRF7970A_CHIP_STATUS_DIRECT             BIT(6)
 223 #define TRF7970A_CHIP_STATUS_STBY               BIT(7)
 224
 225 /* ISO Control Register Bits */
 226 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_662    0x00
 227 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_662  0x01
 228 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648   0x02
 229 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_2648 0x03
 230 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a   0x04
 231 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_667  0x05
 232 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669   0x06
 233 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_2669 0x07
 234 #define TRF7970A_ISO_CTRL_14443A_106            0x08
 235 #define TRF7970A_ISO_CTRL_14443A_212            0x09
 236 #define TRF7970A_ISO_CTRL_14443A_424            0x0a
 237 #define TRF7970A_ISO_CTRL_14443A_848            0x0b
 238 #define TRF7970A_ISO_CTRL_14443B_106            0x0c
 239 #define TRF7970A_ISO_CTRL_14443B_212            0x0d
 240 #define TRF7970A_ISO_CTRL_14443B_424            0x0e
 241 #define TRF7970A_ISO_CTRL_14443B_848            0x0f
 242 #define TRF7970A_ISO_CTRL_FELICA_212            0x1a
 243 #define TRF7970A_ISO_CTRL_FELICA_424            0x1b
 244 #define TRF7970A_ISO_CTRL_NFC_NFCA_106          0x01
 245 #define TRF7970A_ISO_CTRL_NFC_NFCF_212          0x02
 246 #define TRF7970A_ISO_CTRL_NFC_NFCF_424          0x03
 247 #define TRF7970A_ISO_CTRL_NFC_CE_14443A         0x00
 248 #define TRF7970A_ISO_CTRL_NFC_CE_14443B         0x01
 249 #define TRF7970A_ISO_CTRL_NFC_CE                BIT(2)
 250 #define TRF7970A_ISO_CTRL_NFC_ACTIVE            BIT(3)
 251 #define TRF7970A_ISO_CTRL_NFC_INITIATOR         BIT(4)
 252 #define TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE       BIT(5)
 253 #define TRF7970A_ISO_CTRL_RFID                  BIT(5)
 254 #define TRF7970A_ISO_CTRL_DIR_MODE              BIT(6)
 255 #define TRF7970A_ISO_CTRL_RX_CRC_N              BIT(7)  /* true == No CRC */
 256
 257 #define TRF7970A_ISO_CTRL_RFID_SPEED_MASK       0x1f
 258
 259 /* Modulator and SYS_CLK Control Register Bits */
 260 #define TRF7970A_MODULATOR_DEPTH(n)             ((n) & 0x7)
 261 #define TRF7970A_MODULATOR_DEPTH_ASK10          (TRF7970A_MODULATOR_DEPTH(0))
 262 #define TRF7970A_MODULATOR_DEPTH_OOK            (TRF7970A_MODULATOR_DEPTH(1))
 263 #define TRF7970A_MODULATOR_DEPTH_ASK7           (TRF7970A_MODULATOR_DEPTH(2))
 264 #define TRF7970A_MODULATOR_DEPTH_ASK8_5         (TRF7970A_MODULATOR_DEPTH(3))
 265 #define TRF7970A_MODULATOR_DEPTH_ASK13          (TRF7970A_MODULATOR_DEPTH(4))
 266 #define TRF7970A_MODULATOR_DEPTH_ASK16          (TRF7970A_MODULATOR_DEPTH(5))
 267 #define TRF7970A_MODULATOR_DEPTH_ASK22          (TRF7970A_MODULATOR_DEPTH(6))
 268 #define TRF7970A_MODULATOR_DEPTH_ASK30          (TRF7970A_MODULATOR_DEPTH(7))
 269 #define TRF7970A_MODULATOR_EN_ANA               BIT(3)
 270 #define TRF7970A_MODULATOR_CLK(n)               (((n) & 0x3) << 4)
 271 #define TRF7970A_MODULATOR_CLK_DISABLED         (TRF7970A_MODULATOR_CLK(0))
 272 #define TRF7970A_MODULATOR_CLK_3_6              (TRF7970A_MODULATOR_CLK(1))
 273 #define TRF7970A_MODULATOR_CLK_6_13             (TRF7970A_MODULATOR_CLK(2))
 274 #define TRF7970A_MODULATOR_CLK_13_27            (TRF7970A_MODULATOR_CLK(3))
 275 #define TRF7970A_MODULATOR_EN_OOK               BIT(6)
 276 #define TRF7970A_MODULATOR_27MHZ                BIT(7)
 277
 278 #define TRF7970A_RX_SPECIAL_SETTINGS_NO_LIM     BIT(0)
 279 #define TRF7970A_RX_SPECIAL_SETTINGS_AGCR       BIT(1)
 280 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_0DB     (0x0 << 2)
 281 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_5DB     (0x1 << 2)
 282 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_10DB    (0x2 << 2)
 283 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_15DB    (0x3 << 2)
 284 #define TRF7970A_RX_SPECIAL_SETTINGS_HBT        BIT(4)
 285 #define TRF7970A_RX_SPECIAL_SETTINGS_M848       BIT(5)
 286 #define TRF7970A_RX_SPECIAL_SETTINGS_C424       BIT(6)
 287 #define TRF7970A_RX_SPECIAL_SETTINGS_C212       BIT(7)
 288
 289 #define TRF7970A_REG_IO_CTRL_VRS(v)             ((v) & 0x07)
 290 #define TRF7970A_REG_IO_CTRL_IO_LOW             BIT(5)
 291 #define TRF7970A_REG_IO_CTRL_EN_EXT_PA          BIT(6)
 292 #define TRF7970A_REG_IO_CTRL_AUTO_REG           BIT(7)
 293
 294 /* IRQ Status Register Bits */
 295 #define TRF7970A_IRQ_STATUS_NORESP              BIT(0)  /* ISO15693 only */
 296 #define TRF7970A_IRQ_STATUS_NFC_COL_ERROR       BIT(0)
 297 #define TRF7970A_IRQ_STATUS_COL                 BIT(1)
 298 #define TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR   BIT(2)
 299 #define TRF7970A_IRQ_STATUS_NFC_RF              BIT(2)
 300 #define TRF7970A_IRQ_STATUS_PARITY_ERROR        BIT(3)
 301 #define TRF7970A_IRQ_STATUS_NFC_SDD             BIT(3)
 302 #define TRF7970A_IRQ_STATUS_CRC_ERROR           BIT(4)
 303 #define TRF7970A_IRQ_STATUS_NFC_PROTO_ERROR     BIT(4)
 304 #define TRF7970A_IRQ_STATUS_FIFO                BIT(5)
 305 #define TRF7970A_IRQ_STATUS_SRX                 BIT(6)
 306 #define TRF7970A_IRQ_STATUS_TX                  BIT(7)
 307
 308 #define TRF7970A_IRQ_STATUS_ERROR                               \
 309                 (TRF7970A_IRQ_STATUS_COL |                      \
 310                  TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR |        \
 311                  TRF7970A_IRQ_STATUS_PARITY_ERROR |             \
 312                  TRF7970A_IRQ_STATUS_CRC_ERROR)
 313
 314 #define TRF7970A_RSSI_OSC_STATUS_RSSI_MASK      (BIT(2) | BIT(1) | BIT(0))
 315 #define TRF7970A_RSSI_OSC_STATUS_RSSI_X_MASK    (BIT(5) | BIT(4) | BIT(3))
 316 #define TRF7970A_RSSI_OSC_STATUS_RSSI_OSC_OK    BIT(6)
 317
 318 #define TRF7970A_SPECIAL_FCN_REG1_COL_7_6               BIT(0)
 319 #define TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL           BIT(1)
 320 #define TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX              BIT(2)
 321 #define TRF7970A_SPECIAL_FCN_REG1_SP_DIR_MODE           BIT(3)
 322 #define TRF7970A_SPECIAL_FCN_REG1_NEXT_SLOT_37US        BIT(4)
 323 #define TRF7970A_SPECIAL_FCN_REG1_PAR43                 BIT(5)
 324
 325 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_124      (0x0 << 2)
 326 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_120      (0x1 << 2)
 327 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_112      (0x2 << 2)
 328 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96       (0x3 << 2)
 329 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_4        0x0
 330 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_8        0x1
 331 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_16       0x2
 332 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32       0x3
 333
 334 #define TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(v)   ((v) & 0x07)
 335 #define TRF7970A_NFC_LOW_FIELD_LEVEL_CLEX_DIS   BIT(7)
 336
 337 #define TRF7970A_NFC_TARGET_LEVEL_RFDET(v)      ((v) & 0x07)
 338 #define TRF7970A_NFC_TARGET_LEVEL_HI_RF         BIT(3)
 339 #define TRF7970A_NFC_TARGET_LEVEL_SDD_EN        BIT(5)
 340 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_4BYTES   (0x0 << 6)
 341 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_7BYTES   (0x1 << 6)
 342 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_10BYTES  (0x2 << 6)
 343
 344 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106         BIT(0)
 345 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212         BIT(1)
 346 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424         (BIT(0) | BIT(1))
 347 #define TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B        BIT(2)
 348 #define TRF79070A_NFC_TARGET_PROTOCOL_PAS_106           BIT(3)
 349 #define TRF79070A_NFC_TARGET_PROTOCOL_FELICA            BIT(4)
 350 #define TRF79070A_NFC_TARGET_PROTOCOL_RF_L              BIT(6)
 351 #define TRF79070A_NFC_TARGET_PROTOCOL_RF_H              BIT(7)
 352
 353 #define TRF79070A_NFC_TARGET_PROTOCOL_106A              \
 354          (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |          \
 355           TRF79070A_NFC_TARGET_PROTOCOL_RF_L |          \
 356           TRF79070A_NFC_TARGET_PROTOCOL_PAS_106 |       \
 357           TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
 358
 359 #define TRF79070A_NFC_TARGET_PROTOCOL_106B              \
 360          (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |          \
 361           TRF79070A_NFC_TARGET_PROTOCOL_RF_L |          \
 362           TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B |    \
 363           TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
 364
 365 #define TRF79070A_NFC_TARGET_PROTOCOL_212F              \
 366          (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |          \
 367           TRF79070A_NFC_TARGET_PROTOCOL_RF_L |          \
 368           TRF79070A_NFC_TARGET_PROTOCOL_FELICA |        \
 369           TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212)
 370
 371 #define TRF79070A_NFC_TARGET_PROTOCOL_424F              \
 372          (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |          \
 373           TRF79070A_NFC_TARGET_PROTOCOL_RF_L |          \
 374           TRF79070A_NFC_TARGET_PROTOCOL_FELICA |        \
 375           TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424)
 376
 377 #define TRF7970A_FIFO_STATUS_OVERFLOW           BIT(7)
 378
 379 /* NFC (ISO/IEC 14443A) Type 2 Tag commands */
 380 #define NFC_T2T_CMD_READ                        0x30
 381
 382 /* ISO 15693 commands codes */
 383 #define ISO15693_CMD_INVENTORY                  0x01
 384 #define ISO15693_CMD_READ_SINGLE_BLOCK          0x20
 385 #define ISO15693_CMD_WRITE_SINGLE_BLOCK         0x21
 386 #define ISO15693_CMD_LOCK_BLOCK                 0x22
 387 #define ISO15693_CMD_READ_MULTIPLE_BLOCK        0x23
 388 #define ISO15693_CMD_WRITE_MULTIPLE_BLOCK       0x24
 389 #define ISO15693_CMD_SELECT                     0x25
 390 #define ISO15693_CMD_RESET_TO_READY             0x26
 391 #define ISO15693_CMD_WRITE_AFI                  0x27
 392 #define ISO15693_CMD_LOCK_AFI                   0x28
 393 #define ISO15693_CMD_WRITE_DSFID                0x29
 394 #define ISO15693_CMD_LOCK_DSFID                 0x2a
 395 #define ISO15693_CMD_GET_SYSTEM_INFO            0x2b
 396 #define ISO15693_CMD_GET_MULTIPLE_BLOCK_SECURITY_STATUS 0x2c
 397
 398 /* ISO 15693 request and response flags */
 399 #define ISO15693_REQ_FLAG_SUB_CARRIER           BIT(0)
 400 #define ISO15693_REQ_FLAG_DATA_RATE             BIT(1)
 401 #define ISO15693_REQ_FLAG_INVENTORY             BIT(2)
 402 #define ISO15693_REQ_FLAG_PROTOCOL_EXT          BIT(3)
 403 #define ISO15693_REQ_FLAG_SELECT                BIT(4)
 404 #define ISO15693_REQ_FLAG_AFI                   BIT(4)
 405 #define ISO15693_REQ_FLAG_ADDRESS               BIT(5)
 406 #define ISO15693_REQ_FLAG_NB_SLOTS              BIT(5)
 407 #define ISO15693_REQ_FLAG_OPTION                BIT(6)
 408
 409 #define ISO15693_REQ_FLAG_SPEED_MASK \
 410                 (ISO15693_REQ_FLAG_SUB_CARRIER | ISO15693_REQ_FLAG_DATA_RATE)
 411
 412 enum trf7970a_state {
 413         TRF7970A_ST_PWR_OFF,
 414         TRF7970A_ST_RF_OFF,
 415         TRF7970A_ST_IDLE,
 416         TRF7970A_ST_IDLE_RX_BLOCKED,
 417         TRF7970A_ST_WAIT_FOR_TX_FIFO,
 418         TRF7970A_ST_WAIT_FOR_RX_DATA,
 419         TRF7970A_ST_WAIT_FOR_RX_DATA_CONT,
 420         TRF7970A_ST_WAIT_TO_ISSUE_EOF,
 421         TRF7970A_ST_LISTENING,
 422         TRF7970A_ST_LISTENING_MD,
 423         TRF7970A_ST_MAX
 424 };
 425
 426 struct trf7970a {
 427         enum trf7970a_state             state;
 428         struct device                   *dev;
 429         struct spi_device               *spi;
 430         struct regulator                *regulator;
 431         struct nfc_digital_dev          *ddev;
 432         u32                             quirks;
 433         bool                            is_initiator;
 434         bool                            aborting;
 435         struct sk_buff                  *tx_skb;
 436         struct sk_buff                  *rx_skb;
 437         nfc_digital_cmd_complete_t      cb;
 438         void                            *cb_arg;
 439         u8                              chip_status_ctrl;
 440         u8                              iso_ctrl;
 441         u8                              iso_ctrl_tech;
 442         u8                              modulator_sys_clk_ctrl;
 443         u8                              special_fcn_reg1;
 444         u8                              io_ctrl;
 445         unsigned int                    guard_time;
 446         int                             technology;
 447         int                             framing;
 448         u8                              md_rf_tech;
 449         u8                              tx_cmd;
 450         bool                            issue_eof;
 451         struct gpio_desc                *en_gpiod;
 452         struct gpio_desc                *en2_gpiod;
 453         struct mutex                    lock;
 454         unsigned int                    timeout;
 455         bool                            ignore_timeout;
 456         struct delayed_work             timeout_work;
 457 };
 458
 459 static int trf7970a_cmd(struct trf7970a *trf, u8 opcode)
 460 {
 461         u8 cmd = TRF7970A_CMD_BIT_CTRL | TRF7970A_CMD_BIT_OPCODE(opcode);
 462         int ret;
 463
 464         dev_dbg(trf->dev, "cmd: 0x%x\n", cmd);
 465
 466         ret = spi_write(trf->spi, &cmd, 1);
 467         if (ret)
 468                 dev_err(trf->dev, "%s - cmd: 0x%x, ret: %d\n", __func__, cmd,
 469                         ret);
 470         return ret;
 471 }
 472
 473 static int trf7970a_read(struct trf7970a *trf, u8 reg, u8 *val)
 474 {
 475         u8 addr = TRF7970A_CMD_BIT_RW | reg;
 476         int ret;
 477
 478         ret = spi_write_then_read(trf->spi, &addr, 1, val, 1);
 479         if (ret)
 480                 dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
 481                         ret);
 482
 483         dev_dbg(trf->dev, "read(0x%x): 0x%x\n", addr, *val);
 484
 485         return ret;
 486 }
 487
 488 static int trf7970a_read_cont(struct trf7970a *trf, u8 reg, u8 *buf,
 489                               size_t len)
 490 {
 491         u8 addr = reg | TRF7970A_CMD_BIT_RW | TRF7970A_CMD_BIT_CONTINUOUS;
 492         struct spi_transfer t[2];
 493         struct spi_message m;
 494         int ret;
 495
 496         dev_dbg(trf->dev, "read_cont(0x%x, %zd)\n", addr, len);
 497
 498         spi_message_init(&m);
 499
 500         memset(&t, 0, sizeof(t));
 501
 502         t[0].tx_buf = &addr;
 503         t[0].len = sizeof(addr);
 504         spi_message_add_tail(&t[0], &m);
 505
 506         t[1].rx_buf = buf;
 507         t[1].len = len;
 508         spi_message_add_tail(&t[1], &m);
 509
 510         ret = spi_sync(trf->spi, &m);
 511         if (ret)
 512                 dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
 513                         ret);
 514         return ret;
 515 }
 516
 517 static int trf7970a_write(struct trf7970a *trf, u8 reg, u8 val)
 518 {
 519         u8 buf[2] = { reg, val };
 520         int ret;
 521
 522         dev_dbg(trf->dev, "write(0x%x): 0x%x\n", reg, val);
 523
 524         ret = spi_write(trf->spi, buf, 2);
 525         if (ret)
 526                 dev_err(trf->dev, "%s - write: 0x%x 0x%x, ret: %d\n", __func__,
 527                         buf[0], buf[1], ret);
 528
 529         return ret;
 530 }
 531
 532 static int trf7970a_read_irqstatus(struct trf7970a *trf, u8 *status)
 533 {
 534         int ret;
 535         u8 buf[2];
 536         u8 addr;
 537
 538         addr = TRF7970A_IRQ_STATUS | TRF7970A_CMD_BIT_RW;
 539
 540         if (trf->quirks & TRF7970A_QUIRK_IRQ_STATUS_READ) {
 541                 addr |= TRF7970A_CMD_BIT_CONTINUOUS;
 542                 ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
 543         } else {
 544                 ret = spi_write_then_read(trf->spi, &addr, 1, buf, 1);
 545         }
 546
 547         if (ret)
 548                 dev_err(trf->dev, "%s - irqstatus: Status read failed: %d\n",
 549                         __func__, ret);
 550         else
 551                 *status = buf[0];
 552
 553         return ret;
 554 }
 555
 556 static int trf7970a_read_target_proto(struct trf7970a *trf, u8 *target_proto)
 557 {
 558         int ret;
 559         u8 buf[2];
 560         u8 addr;
 561
 562         addr = TRF79070A_NFC_TARGET_PROTOCOL | TRF7970A_CMD_BIT_RW |
 563                TRF7970A_CMD_BIT_CONTINUOUS;
 564
 565         ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
 566         if (ret)
 567                 dev_err(trf->dev, "%s - target_proto: Read failed: %d\n",
 568                         __func__, ret);
 569         else
 570                 *target_proto = buf[0];
 571
 572         return ret;
 573 }
 574
 575 static int trf7970a_mode_detect(struct trf7970a *trf, u8 *rf_tech)
 576 {
 577         int ret;
 578         u8 target_proto, tech;
 579
 580         ret = trf7970a_read_target_proto(trf, &target_proto);
 581         if (ret)
 582                 return ret;
 583
 584         switch (target_proto) {
 585         case TRF79070A_NFC_TARGET_PROTOCOL_106A:
 586                 tech = NFC_DIGITAL_RF_TECH_106A;
 587                 break;
 588         case TRF79070A_NFC_TARGET_PROTOCOL_106B:
 589                 tech = NFC_DIGITAL_RF_TECH_106B;
 590                 break;
 591         case TRF79070A_NFC_TARGET_PROTOCOL_212F:
 592                 tech = NFC_DIGITAL_RF_TECH_212F;
 593                 break;
 594         case TRF79070A_NFC_TARGET_PROTOCOL_424F:
 595                 tech = NFC_DIGITAL_RF_TECH_424F;
 596                 break;
 597         default:
 598                 dev_dbg(trf->dev, "%s - mode_detect: target_proto: 0x%x\n",
 599                         __func__, target_proto);
 600                 return -EIO;
 601         }
 602
 603         *rf_tech = tech;
 604
 605         return ret;
 606 }
 607
 608 static void trf7970a_send_upstream(struct trf7970a *trf)
 609 {
 610         dev_kfree_skb_any(trf->tx_skb);
 611         trf->tx_skb = NULL;
 612
 613         if (trf->rx_skb && !IS_ERR(trf->rx_skb) && !trf->aborting)
 614                 print_hex_dump_debug("trf7970a rx data: ", DUMP_PREFIX_NONE,
 615                                      16, 1, trf->rx_skb->data, trf->rx_skb->len,
 616                                      false);
 617
 618         trf->state = TRF7970A_ST_IDLE;
 619
 620         if (trf->aborting) {
 621                 dev_dbg(trf->dev, "Abort process complete\n");
 622
 623                 if (!IS_ERR(trf->rx_skb)) {
 624                         kfree_skb(trf->rx_skb);
 625                         trf->rx_skb = ERR_PTR(-ECANCELED);
 626                 }
 627
 628                 trf->aborting = false;
 629         }
 630
 631         trf->cb(trf->ddev, trf->cb_arg, trf->rx_skb);
 632
 633         trf->rx_skb = NULL;
 634 }
 635
 636 static void trf7970a_send_err_upstream(struct trf7970a *trf, int errno)
 637 {
 638         dev_dbg(trf->dev, "Error - state: %d, errno: %d\n", trf->state, errno);
 639
 640         cancel_delayed_work(&trf->timeout_work);
 641
 642         kfree_skb(trf->rx_skb);
 643         trf->rx_skb = ERR_PTR(errno);
 644
 645         trf7970a_send_upstream(trf);
 646 }
 647
 648 static int trf7970a_transmit(struct trf7970a *trf, struct sk_buff *skb,
 649                              unsigned int len, u8 *prefix,
 650                              unsigned int prefix_len)
 651 {
 652         struct spi_transfer t[2];
 653         struct spi_message m;
 654         unsigned int timeout;
 655         int ret;
 656
 657         print_hex_dump_debug("trf7970a tx data: ", DUMP_PREFIX_NONE,
 658                              16, 1, skb->data, len, false);
 659
 660         spi_message_init(&m);
 661
 662         memset(&t, 0, sizeof(t));
 663
 664         t[0].tx_buf = prefix;
 665         t[0].len = prefix_len;
 666         spi_message_add_tail(&t[0], &m);
 667
 668         t[1].tx_buf = skb->data;
 669         t[1].len = len;
 670         spi_message_add_tail(&t[1], &m);
 671
 672         ret = spi_sync(trf->spi, &m);
 673         if (ret) {
 674                 dev_err(trf->dev, "%s - Can't send tx data: %d\n", __func__,
 675                         ret);
 676                 return ret;
 677         }
 678
 679         skb_pull(skb, len);
 680
 681         if (skb->len > 0) {
 682                 trf->state = TRF7970A_ST_WAIT_FOR_TX_FIFO;
 683                 timeout = TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT;
 684         } else {
 685                 if (trf->issue_eof) {
 686                         trf->state = TRF7970A_ST_WAIT_TO_ISSUE_EOF;
 687                         timeout = TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF;
 688                 } else {
 689                         trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
 690
 691                         if (!trf->timeout)
 692                                 timeout = TRF7970A_WAIT_FOR_TX_IRQ;
 693                         else
 694                                 timeout = trf->timeout;
 695                 }
 696         }
 697
 698         dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n", timeout,
 699                 trf->state);
 700
 701         schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
 702
 703         return 0;
 704 }
 705
 706 static void trf7970a_fill_fifo(struct trf7970a *trf)
 707 {
 708         struct sk_buff *skb = trf->tx_skb;
 709         unsigned int len;
 710         int ret;
 711         u8 fifo_bytes;
 712         u8 prefix;
 713
 714         ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
 715         if (ret) {
 716                 trf7970a_send_err_upstream(trf, ret);
 717                 return;
 718         }
 719
 720         dev_dbg(trf->dev, "Filling FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
 721
 722         fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 723
 724         /* Calculate how much more data can be written to the fifo */
 725         len = TRF7970A_FIFO_SIZE - fifo_bytes;
 726         if (!len) {
 727                 schedule_delayed_work(&trf->timeout_work,
 728                         msecs_to_jiffies(TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT));
 729                 return;
 730         }
 731
 732         len = min(skb->len, len);
 733
 734         prefix = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_FIFO_IO_REGISTER;
 735
 736         ret = trf7970a_transmit(trf, skb, len, &prefix, sizeof(prefix));
 737         if (ret)
 738                 trf7970a_send_err_upstream(trf, ret);
 739 }
 740
 741 static void trf7970a_drain_fifo(struct trf7970a *trf, u8 status)
 742 {
 743         struct sk_buff *skb = trf->rx_skb;
 744         int ret;
 745         u8 fifo_bytes;
 746
 747         if (status & TRF7970A_IRQ_STATUS_ERROR) {
 748                 trf7970a_send_err_upstream(trf, -EIO);
 749                 return;
 750         }
 751
 752         ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
 753         if (ret) {
 754                 trf7970a_send_err_upstream(trf, ret);
 755                 return;
 756         }
 757
 758         dev_dbg(trf->dev, "Draining FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
 759
 760         fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 761
 762         if (!fifo_bytes)
 763                 goto no_rx_data;
 764
 765         if (fifo_bytes > skb_tailroom(skb)) {
 766                 skb = skb_copy_expand(skb, skb_headroom(skb),
 767                                       max_t(int, fifo_bytes,
 768                                             TRF7970A_RX_SKB_ALLOC_SIZE),
 769                                       GFP_KERNEL);
 770                 if (!skb) {
 771                         trf7970a_send_err_upstream(trf, -ENOMEM);
 772                         return;
 773                 }
 774
 775                 kfree_skb(trf->rx_skb);
 776                 trf->rx_skb = skb;
 777         }
 778
 779         ret = trf7970a_read_cont(trf, TRF7970A_FIFO_IO_REGISTER,
 780                                  skb_put(skb, fifo_bytes), fifo_bytes);
 781         if (ret) {
 782                 trf7970a_send_err_upstream(trf, ret);
 783                 return;
 784         }
 785
 786         /* If received Type 2 ACK/NACK, shift right 4 bits and pass up */
 787         if ((trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T) && (skb->len == 1) &&
 788             (trf->special_fcn_reg1 == TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX)) {
 789                 skb->data[0] >>= 4;
 790                 status = TRF7970A_IRQ_STATUS_SRX;
 791         } else {
 792                 trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA_CONT;
 793
 794                 ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
 795                 if (ret) {
 796                         trf7970a_send_err_upstream(trf, ret);
 797                         return;
 798                 }
 799
 800                 fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 801
 802                 /* If there are bytes in the FIFO, set status to '0' so
 803                  * the if stmt below doesn't fire and the driver will wait
 804                  * for the trf7970a to generate another RX interrupt.
 805                  */
 806                 if (fifo_bytes)
 807                         status = 0;
 808         }
 809
 810 no_rx_data:
 811         if (status == TRF7970A_IRQ_STATUS_SRX) {        /* Receive complete */
 812                 trf7970a_send_upstream(trf);
 813                 return;
 814         }
 815
 816         dev_dbg(trf->dev, "Setting timeout for %d ms\n",
 817                 TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT);
 818
 819         schedule_delayed_work(&trf->timeout_work,
 820                            msecs_to_jiffies(TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT));
 821 }
 822
 823 static irqreturn_t trf7970a_irq(int irq, void *dev_id)
 824 {
 825         struct trf7970a *trf = dev_id;
 826         int ret;
 827         u8 status, fifo_bytes, iso_ctrl;
 828
 829         mutex_lock(&trf->lock);
 830
 831         if (trf->state == TRF7970A_ST_RF_OFF) {
 832                 mutex_unlock(&trf->lock);
 833                 return IRQ_NONE;
 834         }
 835
 836         ret = trf7970a_read_irqstatus(trf, &status);
 837         if (ret) {
 838                 mutex_unlock(&trf->lock);
 839                 return IRQ_NONE;
 840         }
 841
 842         dev_dbg(trf->dev, "IRQ - state: %d, status: 0x%x\n", trf->state,
 843                 status);
 844
 845         if (!status) {
 846                 mutex_unlock(&trf->lock);
 847                 return IRQ_NONE;
 848         }
 849
 850         switch (trf->state) {
 851         case TRF7970A_ST_IDLE:
 852         case TRF7970A_ST_IDLE_RX_BLOCKED:
 853                 /* If initiator and getting interrupts caused by RF noise,
 854                  * turn off the receiver to avoid unnecessary interrupts.
 855                  * It will be turned back on in trf7970a_send_cmd() when
 856                  * the next command is issued.
 857                  */
 858                 if (trf->is_initiator && (status & TRF7970A_IRQ_STATUS_ERROR)) {
 859                         trf7970a_cmd(trf, TRF7970A_CMD_BLOCK_RX);
 860                         trf->state = TRF7970A_ST_IDLE_RX_BLOCKED;
 861                 }
 862
 863                 trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 864                 break;
 865         case TRF7970A_ST_WAIT_FOR_TX_FIFO:
 866                 if (status & TRF7970A_IRQ_STATUS_TX) {
 867                         trf->ignore_timeout =
 868                             !cancel_delayed_work(&trf->timeout_work);
 869                         trf7970a_fill_fifo(trf);
 870                 } else {
 871                         trf7970a_send_err_upstream(trf, -EIO);
 872                 }
 873                 break;
 874         case TRF7970A_ST_WAIT_FOR_RX_DATA:
 875         case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
 876                 if (status & TRF7970A_IRQ_STATUS_SRX) {
 877                         trf->ignore_timeout =
 878                             !cancel_delayed_work(&trf->timeout_work);
 879                         trf7970a_drain_fifo(trf, status);
 880                 } else if (status & TRF7970A_IRQ_STATUS_FIFO) {
 881                         ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS,
 882                                             &fifo_bytes);
 883
 884                         fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
 885
 886                         if (ret)
 887                                 trf7970a_send_err_upstream(trf, ret);
 888                         else if (!fifo_bytes)
 889                                 trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 890                 } else if ((status == TRF7970A_IRQ_STATUS_TX) ||
 891                            (!trf->is_initiator &&
 892                             (status == (TRF7970A_IRQ_STATUS_TX |
 893                                         TRF7970A_IRQ_STATUS_NFC_RF)))) {
 894                         trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 895
 896                         if (!trf->timeout) {
 897                                 trf->ignore_timeout =
 898                                     !cancel_delayed_work(&trf->timeout_work);
 899                                 trf->rx_skb = ERR_PTR(0);
 900                                 trf7970a_send_upstream(trf);
 901                                 break;
 902                         }
 903
 904                         if (trf->is_initiator)
 905                                 break;
 906
 907                         iso_ctrl = trf->iso_ctrl;
 908
 909                         switch (trf->framing) {
 910                         case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
 911                                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
 912                                 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
 913                                 trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
 914                                 break;
 915                         case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
 916                                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
 917                                 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
 918                                 trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
 919                                 break;
 920                         case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
 921                                 ret = trf7970a_write(trf,
 922                                          TRF7970A_SPECIAL_FCN_REG1,
 923                                          TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL);
 924                                 if (ret)
 925                                         goto err_unlock_exit;
 926
 927                                 trf->special_fcn_reg1 =
 928                                     TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL;
 929                                 break;
 930                         default:
 931                                 break;
 932                         }
 933
 934                         if (iso_ctrl != trf->iso_ctrl) {
 935                                 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
 936                                                      iso_ctrl);
 937                                 if (ret)
 938                                         goto err_unlock_exit;
 939
 940                                 trf->iso_ctrl = iso_ctrl;
 941                         }
 942                 } else {
 943                         trf7970a_send_err_upstream(trf, -EIO);
 944                 }
 945                 break;
 946         case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
 947                 if (status != TRF7970A_IRQ_STATUS_TX)
 948                         trf7970a_send_err_upstream(trf, -EIO);
 949                 break;
 950         case TRF7970A_ST_LISTENING:
 951                 if (status & TRF7970A_IRQ_STATUS_SRX) {
 952                         trf->ignore_timeout =
 953                             !cancel_delayed_work(&trf->timeout_work);
 954                         trf7970a_drain_fifo(trf, status);
 955                 } else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
 956                         trf7970a_send_err_upstream(trf, -EIO);
 957                 }
 958                 break;
 959         case TRF7970A_ST_LISTENING_MD:
 960                 if (status & TRF7970A_IRQ_STATUS_SRX) {
 961                         trf->ignore_timeout =
 962                             !cancel_delayed_work(&trf->timeout_work);
 963
 964                         ret = trf7970a_mode_detect(trf, &trf->md_rf_tech);
 965                         if (ret) {
 966                                 trf7970a_send_err_upstream(trf, ret);
 967                         } else {
 968                                 trf->state = TRF7970A_ST_LISTENING;
 969                                 trf7970a_drain_fifo(trf, status);
 970                         }
 971                 } else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
 972                         trf7970a_send_err_upstream(trf, -EIO);
 973                 }
 974                 break;
 975         default:
 976                 dev_err(trf->dev, "%s - Driver in invalid state: %d\n",
 977                         __func__, trf->state);
 978         }
 979
 980 err_unlock_exit:
 981         mutex_unlock(&trf->lock);
 982         return IRQ_HANDLED;
 983 }
 984
 985 static void trf7970a_issue_eof(struct trf7970a *trf)
 986 {
 987         int ret;
 988
 989         dev_dbg(trf->dev, "Issuing EOF\n");
 990
 991         ret = trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
 992         if (ret)
 993                 trf7970a_send_err_upstream(trf, ret);
 994
 995         ret = trf7970a_cmd(trf, TRF7970A_CMD_EOF);
 996         if (ret)
 997                 trf7970a_send_err_upstream(trf, ret);
 998
 999         trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
1000
1001         dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n",
1002                 trf->timeout, trf->state);
1003
1004         schedule_delayed_work(&trf->timeout_work,
1005                               msecs_to_jiffies(trf->timeout));
1006 }
1007
1008 static void trf7970a_timeout_work_handler(struct work_struct *work)
1009 {
1010         struct trf7970a *trf = container_of(work, struct trf7970a,
1011                                             timeout_work.work);
1012
1013         dev_dbg(trf->dev, "Timeout - state: %d, ignore_timeout: %d\n",
1014                 trf->state, trf->ignore_timeout);
1015
1016         mutex_lock(&trf->lock);
1017
1018         if (trf->ignore_timeout)
1019                 trf->ignore_timeout = false;
1020         else if (trf->state == TRF7970A_ST_WAIT_FOR_RX_DATA_CONT)
1021                 trf7970a_drain_fifo(trf, TRF7970A_IRQ_STATUS_SRX);
1022         else if (trf->state == TRF7970A_ST_WAIT_TO_ISSUE_EOF)
1023                 trf7970a_issue_eof(trf);
1024         else
1025                 trf7970a_send_err_upstream(trf, -ETIMEDOUT);
1026
1027         mutex_unlock(&trf->lock);
1028 }
1029
1030 static int trf7970a_init(struct trf7970a *trf)
1031 {
1032         int ret;
1033
1034         dev_dbg(trf->dev, "Initializing device - state: %d\n", trf->state);
1035
1036         ret = trf7970a_cmd(trf, TRF7970A_CMD_SOFT_INIT);
1037         if (ret)
1038                 goto err_out;
1039
1040         ret = trf7970a_cmd(trf, TRF7970A_CMD_IDLE);
1041         if (ret)
1042                 goto err_out;
1043
1044         ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1045                              trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1046         if (ret)
1047                 goto err_out;
1048
1049         ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1050         if (ret)
1051                 goto err_out;
1052
1053         usleep_range(1000, 2000);
1054
1055         trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1056
1057         ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1058                              trf->modulator_sys_clk_ctrl);
1059         if (ret)
1060                 goto err_out;
1061
1062         ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS,
1063                              TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 |
1064                              TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32);
1065         if (ret)
1066                 goto err_out;
1067
1068         ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1, 0);
1069         if (ret)
1070                 goto err_out;
1071
1072         trf->special_fcn_reg1 = 0;
1073
1074         trf->iso_ctrl = 0xff;
1075         return 0;
1076
1077 err_out:
1078         dev_dbg(trf->dev, "Couldn't init device: %d\n", ret);
1079         return ret;
1080 }
1081
1082 static void trf7970a_switch_rf_off(struct trf7970a *trf)
1083 {
1084         if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1085             (trf->state == TRF7970A_ST_RF_OFF))
1086                 return;
1087
1088         dev_dbg(trf->dev, "Switching rf off\n");
1089
1090         trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1091
1092         trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, trf->chip_status_ctrl);
1093
1094         trf->aborting = false;
1095         trf->state = TRF7970A_ST_RF_OFF;
1096
1097         pm_runtime_mark_last_busy(trf->dev);
1098         pm_runtime_put_autosuspend(trf->dev);
1099 }
1100
1101 static int trf7970a_switch_rf_on(struct trf7970a *trf)
1102 {
1103         int ret;
1104
1105         dev_dbg(trf->dev, "Switching rf on\n");
1106
1107         pm_runtime_get_sync(trf->dev);
1108
1109         if (trf->state != TRF7970A_ST_RF_OFF) { /* Power on, RF off */
1110                 dev_err(trf->dev, "%s - Incorrect state: %d\n", __func__,
1111                         trf->state);
1112                 return -EINVAL;
1113         }
1114
1115         ret = trf7970a_init(trf);
1116         if (ret) {
1117                 dev_err(trf->dev, "%s - Can't initialize: %d\n", __func__, ret);
1118                 return ret;
1119         }
1120
1121         trf->state = TRF7970A_ST_IDLE;
1122
1123         return 0;
1124 }
1125
1126 static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on)
1127 {
1128         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1129         int ret = 0;
1130
1131         dev_dbg(trf->dev, "Switching RF - state: %d, on: %d\n", trf->state, on);
1132
1133         mutex_lock(&trf->lock);
1134
1135         if (on) {
1136                 switch (trf->state) {
1137                 case TRF7970A_ST_PWR_OFF:
1138                 case TRF7970A_ST_RF_OFF:
1139                         ret = trf7970a_switch_rf_on(trf);
1140                         break;
1141                 case TRF7970A_ST_IDLE:
1142                 case TRF7970A_ST_IDLE_RX_BLOCKED:
1143                         break;
1144                 default:
1145                         dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1146                                 __func__, trf->state, on);
1147                         trf7970a_switch_rf_off(trf);
1148                         ret = -EINVAL;
1149                 }
1150         } else {
1151                 switch (trf->state) {
1152                 case TRF7970A_ST_PWR_OFF:
1153                 case TRF7970A_ST_RF_OFF:
1154                         break;
1155                 default:
1156                         dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1157                                 __func__, trf->state, on);
1158                         ret = -EINVAL;
1159                         /* FALLTHROUGH */
1160                 case TRF7970A_ST_IDLE:
1161                 case TRF7970A_ST_IDLE_RX_BLOCKED:
1162                 case TRF7970A_ST_WAIT_FOR_RX_DATA:
1163                 case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1164                         trf7970a_switch_rf_off(trf);
1165                 }
1166         }
1167
1168         mutex_unlock(&trf->lock);
1169         return ret;
1170 }
1171
1172 static int trf7970a_in_config_rf_tech(struct trf7970a *trf, int tech)
1173 {
1174         int ret = 0;
1175
1176         dev_dbg(trf->dev, "rf technology: %d\n", tech);
1177
1178         switch (tech) {
1179         case NFC_DIGITAL_RF_TECH_106A:
1180                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443A_106;
1181                 trf->modulator_sys_clk_ctrl =
1182                     (trf->modulator_sys_clk_ctrl & 0xf8) |
1183                     TRF7970A_MODULATOR_DEPTH_OOK;
1184                 trf->guard_time = TRF7970A_GUARD_TIME_NFCA;
1185                 break;
1186         case NFC_DIGITAL_RF_TECH_106B:
1187                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443B_106;
1188                 trf->modulator_sys_clk_ctrl =
1189                     (trf->modulator_sys_clk_ctrl & 0xf8) |
1190                     TRF7970A_MODULATOR_DEPTH_ASK10;
1191                 trf->guard_time = TRF7970A_GUARD_TIME_NFCB;
1192                 break;
1193         case NFC_DIGITAL_RF_TECH_212F:
1194                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_212;
1195                 trf->modulator_sys_clk_ctrl =
1196                     (trf->modulator_sys_clk_ctrl & 0xf8) |
1197                     TRF7970A_MODULATOR_DEPTH_ASK10;
1198                 trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1199                 break;
1200         case NFC_DIGITAL_RF_TECH_424F:
1201                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_424;
1202                 trf->modulator_sys_clk_ctrl =
1203                     (trf->modulator_sys_clk_ctrl & 0xf8) |
1204                     TRF7970A_MODULATOR_DEPTH_ASK10;
1205                 trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1206                 break;
1207         case NFC_DIGITAL_RF_TECH_ISO15693:
1208                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1209                 trf->modulator_sys_clk_ctrl =
1210                     (trf->modulator_sys_clk_ctrl & 0xf8) |
1211                     TRF7970A_MODULATOR_DEPTH_OOK;
1212                 trf->guard_time = TRF7970A_GUARD_TIME_15693;
1213                 break;
1214         default:
1215                 dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1216                 return -EINVAL;
1217         }
1218
1219         trf->technology = tech;
1220
1221         /* If in initiator mode and not changing the RF tech due to a
1222          * PSL sequence (indicated by 'trf->iso_ctrl == 0xff' from
1223          * trf7970a_init()), clear the NFC Target Detection Level register
1224          * due to erratum.
1225          */
1226         if (trf->iso_ctrl == 0xff)
1227                 ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1228
1229         return ret;
1230 }
1231
1232 static int trf7970a_is_rf_field(struct trf7970a *trf, bool *is_rf_field)
1233 {
1234         int ret;
1235         u8 rssi;
1236
1237         ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1238                              trf->chip_status_ctrl |
1239                              TRF7970A_CHIP_STATUS_REC_ON);
1240         if (ret)
1241                 return ret;
1242
1243         ret = trf7970a_cmd(trf, TRF7970A_CMD_TEST_EXT_RF);
1244         if (ret)
1245                 return ret;
1246
1247         usleep_range(50, 60);
1248
1249         ret = trf7970a_read(trf, TRF7970A_RSSI_OSC_STATUS, &rssi);
1250         if (ret)
1251                 return ret;
1252
1253         ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1254                              trf->chip_status_ctrl);
1255         if (ret)
1256                 return ret;
1257
1258         if (rssi & TRF7970A_RSSI_OSC_STATUS_RSSI_MASK)
1259                 *is_rf_field = true;
1260         else
1261                 *is_rf_field = false;
1262
1263         return 0;
1264 }
1265
1266 static int trf7970a_in_config_framing(struct trf7970a *trf, int framing)
1267 {
1268         u8 iso_ctrl = trf->iso_ctrl_tech;
1269         bool is_rf_field = false;
1270         int ret;
1271
1272         dev_dbg(trf->dev, "framing: %d\n", framing);
1273
1274         switch (framing) {
1275         case NFC_DIGITAL_FRAMING_NFCA_SHORT:
1276         case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1277                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1278                 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1279                 break;
1280         case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1281         case NFC_DIGITAL_FRAMING_NFCA_T4T:
1282         case NFC_DIGITAL_FRAMING_NFCB:
1283         case NFC_DIGITAL_FRAMING_NFCB_T4T:
1284         case NFC_DIGITAL_FRAMING_NFCF:
1285         case NFC_DIGITAL_FRAMING_NFCF_T3T:
1286         case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY:
1287         case NFC_DIGITAL_FRAMING_ISO15693_T5T:
1288         case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1289         case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1290                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1291                 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1292                 break;
1293         case NFC_DIGITAL_FRAMING_NFCA_T2T:
1294                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1295                 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1296                 break;
1297         default:
1298                 dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1299                 return -EINVAL;
1300         }
1301
1302         trf->framing = framing;
1303
1304         if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1305                 ret = trf7970a_is_rf_field(trf, &is_rf_field);
1306                 if (ret)
1307                         return ret;
1308
1309                 if (is_rf_field)
1310                         return -EBUSY;
1311         }
1312
1313         if (iso_ctrl != trf->iso_ctrl) {
1314                 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1315                 if (ret)
1316                         return ret;
1317
1318                 trf->iso_ctrl = iso_ctrl;
1319
1320                 ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1321                                      trf->modulator_sys_clk_ctrl);
1322                 if (ret)
1323                         return ret;
1324         }
1325
1326         if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1327                 ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1328                                      trf->chip_status_ctrl |
1329                                      TRF7970A_CHIP_STATUS_RF_ON);
1330                 if (ret)
1331                         return ret;
1332
1333                 trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1334
1335                 usleep_range(trf->guard_time, trf->guard_time + 1000);
1336         }
1337
1338         return 0;
1339 }
1340
1341 static int trf7970a_in_configure_hw(struct nfc_digital_dev *ddev, int type,
1342                                     int param)
1343 {
1344         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1345         int ret;
1346
1347         dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1348
1349         mutex_lock(&trf->lock);
1350
1351         trf->is_initiator = true;
1352
1353         if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1354             (trf->state == TRF7970A_ST_RF_OFF)) {
1355                 ret = trf7970a_switch_rf_on(trf);
1356                 if (ret)
1357                         goto err_unlock;
1358         }
1359
1360         switch (type) {
1361         case NFC_DIGITAL_CONFIG_RF_TECH:
1362                 ret = trf7970a_in_config_rf_tech(trf, param);
1363                 break;
1364         case NFC_DIGITAL_CONFIG_FRAMING:
1365                 ret = trf7970a_in_config_framing(trf, param);
1366                 break;
1367         default:
1368                 dev_dbg(trf->dev, "Unknown type: %d\n", type);
1369                 ret = -EINVAL;
1370         }
1371
1372 err_unlock:
1373         mutex_unlock(&trf->lock);
1374         return ret;
1375 }
1376
1377 static int trf7970a_is_iso15693_write_or_lock(u8 cmd)
1378 {
1379         switch (cmd) {
1380         case ISO15693_CMD_WRITE_SINGLE_BLOCK:
1381         case ISO15693_CMD_LOCK_BLOCK:
1382         case ISO15693_CMD_WRITE_MULTIPLE_BLOCK:
1383         case ISO15693_CMD_WRITE_AFI:
1384         case ISO15693_CMD_LOCK_AFI:
1385         case ISO15693_CMD_WRITE_DSFID:
1386         case ISO15693_CMD_LOCK_DSFID:
1387                 return 1;
1388                 break;
1389         default:
1390                 return 0;
1391         }
1392 }
1393
1394 static int trf7970a_per_cmd_config(struct trf7970a *trf, struct sk_buff *skb)
1395 {
1396         u8 *req = skb->data;
1397         u8 special_fcn_reg1, iso_ctrl;
1398         int ret;
1399
1400         trf->issue_eof = false;
1401
1402         /* When issuing Type 2 read command, make sure the '4_bit_RX' bit in
1403          * special functions register 1 is cleared; otherwise, its a write or
1404          * sector select command and '4_bit_RX' must be set.
1405          *
1406          * When issuing an ISO 15693 command, inspect the flags byte to see
1407          * what speed to use.  Also, remember if the OPTION flag is set on
1408          * a Type 5 write or lock command so the driver will know that it
1409          * has to send an EOF in order to get a response.
1410          */
1411         if ((trf->technology == NFC_DIGITAL_RF_TECH_106A) &&
1412             (trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T)) {
1413                 if (req[0] == NFC_T2T_CMD_READ)
1414                         special_fcn_reg1 = 0;
1415                 else
1416                         special_fcn_reg1 = TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX;
1417
1418                 if (special_fcn_reg1 != trf->special_fcn_reg1) {
1419                         ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1,
1420                                              special_fcn_reg1);
1421                         if (ret)
1422                                 return ret;
1423
1424                         trf->special_fcn_reg1 = special_fcn_reg1;
1425                 }
1426         } else if (trf->technology == NFC_DIGITAL_RF_TECH_ISO15693) {
1427                 iso_ctrl = trf->iso_ctrl & ~TRF7970A_ISO_CTRL_RFID_SPEED_MASK;
1428
1429                 switch (req[0] & ISO15693_REQ_FLAG_SPEED_MASK) {
1430                 case 0x00:
1431                         iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_662;
1432                         break;
1433                 case ISO15693_REQ_FLAG_SUB_CARRIER:
1434                         iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a;
1435                         break;
1436                 case ISO15693_REQ_FLAG_DATA_RATE:
1437                         iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1438                         break;
1439                 case (ISO15693_REQ_FLAG_SUB_CARRIER |
1440                       ISO15693_REQ_FLAG_DATA_RATE):
1441                         iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669;
1442                         break;
1443                 }
1444
1445                 if (iso_ctrl != trf->iso_ctrl) {
1446                         ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1447                         if (ret)
1448                                 return ret;
1449
1450                         trf->iso_ctrl = iso_ctrl;
1451                 }
1452
1453                 if ((trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) &&
1454                     trf7970a_is_iso15693_write_or_lock(req[1]) &&
1455                     (req[0] & ISO15693_REQ_FLAG_OPTION))
1456                         trf->issue_eof = true;
1457         }
1458
1459         return 0;
1460 }
1461
1462 static int trf7970a_send_cmd(struct nfc_digital_dev *ddev,
1463                              struct sk_buff *skb, u16 timeout,
1464                              nfc_digital_cmd_complete_t cb, void *arg)
1465 {
1466         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1467         u8 prefix[5];
1468         unsigned int len;
1469         int ret;
1470         u8 status;
1471
1472         dev_dbg(trf->dev, "New request - state: %d, timeout: %d ms, len: %d\n",
1473                 trf->state, timeout, skb->len);
1474
1475         if (skb->len > TRF7970A_TX_MAX)
1476                 return -EINVAL;
1477
1478         mutex_lock(&trf->lock);
1479
1480         if ((trf->state != TRF7970A_ST_IDLE) &&
1481             (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1482                 dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1483                         trf->state);
1484                 ret = -EIO;
1485                 goto out_err;
1486         }
1487
1488         if (trf->aborting) {
1489                 dev_dbg(trf->dev, "Abort process complete\n");
1490                 trf->aborting = false;
1491                 ret = -ECANCELED;
1492                 goto out_err;
1493         }
1494
1495         if (timeout) {
1496                 trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1497                                                  GFP_KERNEL);
1498                 if (!trf->rx_skb) {
1499                         dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1500                         ret = -ENOMEM;
1501                         goto out_err;
1502                 }
1503         }
1504
1505         if (trf->state == TRF7970A_ST_IDLE_RX_BLOCKED) {
1506                 ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1507                 if (ret)
1508                         goto out_err;
1509
1510                 trf->state = TRF7970A_ST_IDLE;
1511         }
1512
1513         if (trf->is_initiator) {
1514                 ret = trf7970a_per_cmd_config(trf, skb);
1515                 if (ret)
1516                         goto out_err;
1517         }
1518
1519         trf->ddev = ddev;
1520         trf->tx_skb = skb;
1521         trf->cb = cb;
1522         trf->cb_arg = arg;
1523         trf->timeout = timeout;
1524         trf->ignore_timeout = false;
1525
1526         len = skb->len;
1527
1528         /* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
1529          * on what the current framing is, the address of the TX length byte 1
1530          * register (0x1d), and the 2 byte length of the data to be transmitted.
1531          * That totals 5 bytes.
1532          */
1533         prefix[0] = TRF7970A_CMD_BIT_CTRL |
1534             TRF7970A_CMD_BIT_OPCODE(TRF7970A_CMD_FIFO_RESET);
1535         prefix[1] = TRF7970A_CMD_BIT_CTRL |
1536             TRF7970A_CMD_BIT_OPCODE(trf->tx_cmd);
1537         prefix[2] = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_TX_LENGTH_BYTE1;
1538
1539         if (trf->framing == NFC_DIGITAL_FRAMING_NFCA_SHORT) {
1540                 prefix[3] = 0x00;
1541                 prefix[4] = 0x0f;       /* 7 bits */
1542         } else {
1543                 prefix[3] = (len & 0xf00) >> 4;
1544                 prefix[3] |= ((len & 0xf0) >> 4);
1545                 prefix[4] = ((len & 0x0f) << 4);
1546         }
1547
1548         len = min_t(int, skb->len, TRF7970A_FIFO_SIZE);
1549
1550         /* Clear possible spurious interrupt */
1551         ret = trf7970a_read_irqstatus(trf, &status);
1552         if (ret)
1553                 goto out_err;
1554
1555         ret = trf7970a_transmit(trf, skb, len, prefix, sizeof(prefix));
1556         if (ret) {
1557                 kfree_skb(trf->rx_skb);
1558                 trf->rx_skb = NULL;
1559         }
1560
1561 out_err:
1562         mutex_unlock(&trf->lock);
1563         return ret;
1564 }
1565
1566 static int trf7970a_tg_config_rf_tech(struct trf7970a *trf, int tech)
1567 {
1568         int ret = 0;
1569
1570         dev_dbg(trf->dev, "rf technology: %d\n", tech);
1571
1572         switch (tech) {
1573         case NFC_DIGITAL_RF_TECH_106A:
1574                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1575                     TRF7970A_ISO_CTRL_NFC_CE | TRF7970A_ISO_CTRL_NFC_CE_14443A;
1576                 trf->modulator_sys_clk_ctrl =
1577                     (trf->modulator_sys_clk_ctrl & 0xf8) |
1578                     TRF7970A_MODULATOR_DEPTH_OOK;
1579                 break;
1580         case NFC_DIGITAL_RF_TECH_212F:
1581                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1582                     TRF7970A_ISO_CTRL_NFC_NFCF_212;
1583                 trf->modulator_sys_clk_ctrl =
1584                     (trf->modulator_sys_clk_ctrl & 0xf8) |
1585                     TRF7970A_MODULATOR_DEPTH_ASK10;
1586                 break;
1587         case NFC_DIGITAL_RF_TECH_424F:
1588                 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1589                     TRF7970A_ISO_CTRL_NFC_NFCF_424;
1590                 trf->modulator_sys_clk_ctrl =
1591                     (trf->modulator_sys_clk_ctrl & 0xf8) |
1592                     TRF7970A_MODULATOR_DEPTH_ASK10;
1593                 break;
1594         default:
1595                 dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1596                 return -EINVAL;
1597         }
1598
1599         trf->technology = tech;
1600
1601         /* Normally we write the ISO_CTRL register in
1602          * trf7970a_tg_config_framing() because the framing can change
1603          * the value written.  However, when sending a PSL RES,
1604          * digital_tg_send_psl_res_complete() doesn't call
1605          * trf7970a_tg_config_framing() so we must write the register
1606          * here.
1607          */
1608         if ((trf->framing == NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED) &&
1609             (trf->iso_ctrl_tech != trf->iso_ctrl)) {
1610                 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
1611                                      trf->iso_ctrl_tech);
1612
1613                 trf->iso_ctrl = trf->iso_ctrl_tech;
1614         }
1615
1616         return ret;
1617 }
1618
1619 /* Since this is a target routine, several of the framing calls are
1620  * made between receiving the request and sending the response so they
1621  * should take effect until after the response is sent.  This is accomplished
1622  * by skipping the ISO_CTRL register write here and doing it in the interrupt
1623  * handler.
1624  */
1625 static int trf7970a_tg_config_framing(struct trf7970a *trf, int framing)
1626 {
1627         u8 iso_ctrl = trf->iso_ctrl_tech;
1628         int ret;
1629
1630         dev_dbg(trf->dev, "framing: %d\n", framing);
1631
1632         switch (framing) {
1633         case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1634                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1635                 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1636                 break;
1637         case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1638         case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1639         case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
1640                 /* These ones are applied in the interrupt handler */
1641                 iso_ctrl = trf->iso_ctrl; /* Don't write to ISO_CTRL yet */
1642                 break;
1643         case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1644                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1645                 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1646                 break;
1647         case NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED:
1648                 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1649                 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1650                 break;
1651         default:
1652                 dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1653                 return -EINVAL;
1654         }
1655
1656         trf->framing = framing;
1657
1658         if (iso_ctrl != trf->iso_ctrl) {
1659                 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1660                 if (ret)
1661                         return ret;
1662
1663                 trf->iso_ctrl = iso_ctrl;
1664
1665                 ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1666                                      trf->modulator_sys_clk_ctrl);
1667                 if (ret)
1668                         return ret;
1669         }
1670
1671         if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1672                 ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1673                                      trf->chip_status_ctrl |
1674                                      TRF7970A_CHIP_STATUS_RF_ON);
1675                 if (ret)
1676                         return ret;
1677
1678                 trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1679         }
1680
1681         return 0;
1682 }
1683
1684 static int trf7970a_tg_configure_hw(struct nfc_digital_dev *ddev, int type,
1685                                     int param)
1686 {
1687         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1688         int ret;
1689
1690         dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1691
1692         mutex_lock(&trf->lock);
1693
1694         trf->is_initiator = false;
1695
1696         if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1697             (trf->state == TRF7970A_ST_RF_OFF)) {
1698                 ret = trf7970a_switch_rf_on(trf);
1699                 if (ret)
1700                         goto err_unlock;
1701         }
1702
1703         switch (type) {
1704         case NFC_DIGITAL_CONFIG_RF_TECH:
1705                 ret = trf7970a_tg_config_rf_tech(trf, param);
1706                 break;
1707         case NFC_DIGITAL_CONFIG_FRAMING:
1708                 ret = trf7970a_tg_config_framing(trf, param);
1709                 break;
1710         default:
1711                 dev_dbg(trf->dev, "Unknown type: %d\n", type);
1712                 ret = -EINVAL;
1713         }
1714
1715 err_unlock:
1716         mutex_unlock(&trf->lock);
1717         return ret;
1718 }
1719
1720 static int _trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1721                                nfc_digital_cmd_complete_t cb, void *arg,
1722                                bool mode_detect)
1723 {
1724         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1725         int ret;
1726
1727         mutex_lock(&trf->lock);
1728
1729         if ((trf->state != TRF7970A_ST_IDLE) &&
1730             (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1731                 dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1732                         trf->state);
1733                 ret = -EIO;
1734                 goto out_err;
1735         }
1736
1737         if (trf->aborting) {
1738                 dev_dbg(trf->dev, "Abort process complete\n");
1739                 trf->aborting = false;
1740                 ret = -ECANCELED;
1741                 goto out_err;
1742         }
1743
1744         trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1745                                          GFP_KERNEL);
1746         if (!trf->rx_skb) {
1747                 dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1748                 ret = -ENOMEM;
1749                 goto out_err;
1750         }
1751
1752         ret = trf7970a_write(trf, TRF7970A_RX_SPECIAL_SETTINGS,
1753                              TRF7970A_RX_SPECIAL_SETTINGS_HBT |
1754                              TRF7970A_RX_SPECIAL_SETTINGS_M848 |
1755                              TRF7970A_RX_SPECIAL_SETTINGS_C424 |
1756                              TRF7970A_RX_SPECIAL_SETTINGS_C212);
1757         if (ret)
1758                 goto out_err;
1759
1760         ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1761                              trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1762         if (ret)
1763                 goto out_err;
1764
1765         ret = trf7970a_write(trf, TRF7970A_NFC_LOW_FIELD_LEVEL,
1766                              TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(0x3));
1767         if (ret)
1768                 goto out_err;
1769
1770         ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL,
1771                              TRF7970A_NFC_TARGET_LEVEL_RFDET(0x7));
1772         if (ret)
1773                 goto out_err;
1774
1775         trf->ddev = ddev;
1776         trf->cb = cb;
1777         trf->cb_arg = arg;
1778         trf->timeout = timeout;
1779         trf->ignore_timeout = false;
1780
1781         ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1782         if (ret)
1783                 goto out_err;
1784
1785         trf->state = mode_detect ? TRF7970A_ST_LISTENING_MD :
1786                                    TRF7970A_ST_LISTENING;
1787
1788         schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
1789
1790 out_err:
1791         mutex_unlock(&trf->lock);
1792         return ret;
1793 }
1794
1795 static int trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1796                               nfc_digital_cmd_complete_t cb, void *arg)
1797 {
1798         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1799
1800         dev_dbg(trf->dev, "Listen - state: %d, timeout: %d ms\n",
1801                 trf->state, timeout);
1802
1803         return _trf7970a_tg_listen(ddev, timeout, cb, arg, false);
1804 }
1805
1806 static int trf7970a_tg_listen_md(struct nfc_digital_dev *ddev,
1807                                  u16 timeout, nfc_digital_cmd_complete_t cb,
1808                                  void *arg)
1809 {
1810         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1811         int ret;
1812
1813         dev_dbg(trf->dev, "Listen MD - state: %d, timeout: %d ms\n",
1814                 trf->state, timeout);
1815
1816         ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
1817                                        NFC_DIGITAL_RF_TECH_106A);
1818         if (ret)
1819                 return ret;
1820
1821         ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1822                                        NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
1823         if (ret)
1824                 return ret;
1825
1826         return _trf7970a_tg_listen(ddev, timeout, cb, arg, true);
1827 }
1828
1829 static int trf7970a_tg_get_rf_tech(struct nfc_digital_dev *ddev, u8 *rf_tech)
1830 {
1831         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1832
1833         dev_dbg(trf->dev, "Get RF Tech - state: %d, rf_tech: %d\n",
1834                 trf->state, trf->md_rf_tech);
1835
1836         *rf_tech = trf->md_rf_tech;
1837
1838         return 0;
1839 }
1840
1841 static void trf7970a_abort_cmd(struct nfc_digital_dev *ddev)
1842 {
1843         struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1844
1845         dev_dbg(trf->dev, "Abort process initiated\n");
1846
1847         mutex_lock(&trf->lock);
1848
1849         switch (trf->state) {
1850         case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1851         case TRF7970A_ST_WAIT_FOR_RX_DATA:
1852         case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1853         case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1854                 trf->aborting = true;
1855                 break;
1856         case TRF7970A_ST_LISTENING:
1857                 trf->ignore_timeout = !cancel_delayed_work(&trf->timeout_work);
1858                 trf7970a_send_err_upstream(trf, -ECANCELED);
1859                 dev_dbg(trf->dev, "Abort process complete\n");
1860                 break;
1861         default:
1862                 break;
1863         }
1864
1865         mutex_unlock(&trf->lock);
1866 }
1867
1868 static struct nfc_digital_ops trf7970a_nfc_ops = {
1869         .in_configure_hw        = trf7970a_in_configure_hw,
1870         .in_send_cmd            = trf7970a_send_cmd,
1871         .tg_configure_hw        = trf7970a_tg_configure_hw,
1872         .tg_send_cmd            = trf7970a_send_cmd,
1873         .tg_listen              = trf7970a_tg_listen,
1874         .tg_listen_md           = trf7970a_tg_listen_md,
1875         .tg_get_rf_tech         = trf7970a_tg_get_rf_tech,
1876         .switch_rf              = trf7970a_switch_rf,
1877         .abort_cmd              = trf7970a_abort_cmd,
1878 };
1879
1880 static int trf7970a_power_up(struct trf7970a *trf)
1881 {
1882         int ret;
1883
1884         dev_dbg(trf->dev, "Powering up - state: %d\n", trf->state);
1885
1886         if (trf->state != TRF7970A_ST_PWR_OFF)
1887                 return 0;
1888
1889         ret = regulator_enable(trf->regulator);
1890         if (ret) {
1891                 dev_err(trf->dev, "%s - Can't enable VIN: %d\n", __func__, ret);
1892                 return ret;
1893         }
1894
1895         usleep_range(5000, 6000);
1896
1897         if (trf->en2_gpiod &&
1898             !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW)) {
1899                 gpiod_set_value_cansleep(trf->en2_gpiod, 1);
1900                 usleep_range(1000, 2000);
1901         }
1902
1903         gpiod_set_value_cansleep(trf->en_gpiod, 1);
1904
1905         usleep_range(20000, 21000);
1906
1907         trf->state = TRF7970A_ST_RF_OFF;
1908
1909         return 0;
1910 }
1911
1912 static int trf7970a_power_down(struct trf7970a *trf)
1913 {
1914         int ret;
1915
1916         dev_dbg(trf->dev, "Powering down - state: %d\n", trf->state);
1917
1918         if (trf->state == TRF7970A_ST_PWR_OFF)
1919                 return 0;
1920
1921         if (trf->state != TRF7970A_ST_RF_OFF) {
1922                 dev_dbg(trf->dev, "Can't power down - not RF_OFF state (%d)\n",
1923                         trf->state);
1924                 return -EBUSY;
1925         }
1926
1927         gpiod_set_value_cansleep(trf->en_gpiod, 0);
1928
1929         if (trf->en2_gpiod && !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW))
1930                 gpiod_set_value_cansleep(trf->en2_gpiod, 0);
1931
1932         ret = regulator_disable(trf->regulator);
1933         if (ret)
1934                 dev_err(trf->dev, "%s - Can't disable VIN: %d\n", __func__,
1935                         ret);
1936
1937         trf->state = TRF7970A_ST_PWR_OFF;
1938
1939         return ret;
1940 }
1941
1942 static int trf7970a_startup(struct trf7970a *trf)
1943 {
1944         int ret;
1945
1946         ret = trf7970a_power_up(trf);
1947         if (ret)
1948                 return ret;
1949
1950         pm_runtime_set_active(trf->dev);
1951         pm_runtime_enable(trf->dev);
1952         pm_runtime_mark_last_busy(trf->dev);
1953
1954         return 0;
1955 }
1956
1957 static void trf7970a_shutdown(struct trf7970a *trf)
1958 {
1959         switch (trf->state) {
1960         case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1961         case TRF7970A_ST_WAIT_FOR_RX_DATA:
1962         case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1963         case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1964         case TRF7970A_ST_LISTENING:
1965                 trf7970a_send_err_upstream(trf, -ECANCELED);
1966                 /* FALLTHROUGH */
1967         case TRF7970A_ST_IDLE:
1968         case TRF7970A_ST_IDLE_RX_BLOCKED:
1969                 trf7970a_switch_rf_off(trf);
1970                 break;
1971         default:
1972                 break;
1973         }
1974
1975         pm_runtime_disable(trf->dev);
1976         pm_runtime_set_suspended(trf->dev);
1977
1978         trf7970a_power_down(trf);
1979 }
1980
1981 static int trf7970a_get_autosuspend_delay(struct device_node *np)
1982 {
1983         int autosuspend_delay, ret;
1984
1985         ret = of_property_read_u32(np, "autosuspend-delay", &autosuspend_delay);
1986         if (ret)
1987                 autosuspend_delay = TRF7970A_AUTOSUSPEND_DELAY;
1988
1989         return autosuspend_delay;
1990 }
1991
1992 static int trf7970a_probe(struct spi_device *spi)
1993 {
1994         struct device_node *np = spi->dev.of_node;
1995         struct trf7970a *trf;
1996         int uvolts, autosuspend_delay, ret;
1997         u32 clk_freq = TRF7970A_13MHZ_CLOCK_FREQUENCY;
1998
1999         if (!np) {
2000                 dev_err(&spi->dev, "No Device Tree entry\n");
2001                 return -EINVAL;
2002         }
2003
2004         trf = devm_kzalloc(&spi->dev, sizeof(*trf), GFP_KERNEL);
2005         if (!trf)
2006                 return -ENOMEM;
2007
2008         trf->state = TRF7970A_ST_PWR_OFF;
2009         trf->dev = &spi->dev;
2010         trf->spi = spi;
2011
2012         spi->mode = SPI_MODE_1;
2013         spi->bits_per_word = 8;
2014
2015         ret = spi_setup(spi);
2016         if (ret < 0) {
2017                 dev_err(trf->dev, "Can't set up SPI Communication\n");
2018                 return ret;
2019         }
2020
2021         if (of_property_read_bool(np, "irq-status-read-quirk"))
2022                 trf->quirks |= TRF7970A_QUIRK_IRQ_STATUS_READ;
2023
2024         /* There are two enable pins - only EN must be present in the DT */
2025         trf->en_gpiod = devm_gpiod_get_index(trf->dev, "ti,enable", 0,
2026                                              GPIOD_OUT_LOW);
2027         if (IS_ERR(trf->en_gpiod)) {
2028                 dev_err(trf->dev, "No EN GPIO property\n");
2029                 return PTR_ERR(trf->en_gpiod);
2030         }
2031
2032         trf->en2_gpiod = devm_gpiod_get_index_optional(trf->dev, "ti,enable", 1,
2033                                                        GPIOD_OUT_LOW);
2034         if (!trf->en2_gpiod) {
2035                 dev_info(trf->dev, "No EN2 GPIO property\n");
2036         } else if (IS_ERR(trf->en2_gpiod)) {
2037                 dev_err(trf->dev, "Error getting EN2 GPIO property: %ld\n",
2038                         PTR_ERR(trf->en2_gpiod));
2039                 return PTR_ERR(trf->en2_gpiod);
2040         } else if (of_property_read_bool(np, "en2-rf-quirk")) {
2041                 trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;
2042         }
2043
2044         of_property_read_u32(np, "clock-frequency", &clk_freq);
2045         if ((clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY) &&
2046             (clk_freq != TRF7970A_13MHZ_CLOCK_FREQUENCY)) {
2047                 dev_err(trf->dev,
2048                         "clock-frequency (%u Hz) unsupported\n", clk_freq);
2049                 return -EINVAL;
2050         }
2051
2052         if (clk_freq == TRF7970A_27MHZ_CLOCK_FREQUENCY) {
2053                 trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_27MHZ;
2054                 dev_dbg(trf->dev, "trf7970a configured for 27MHz crystal\n");
2055         } else {
2056                 trf->modulator_sys_clk_ctrl = 0;
2057         }
2058
2059         ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL,
2060                                         trf7970a_irq,
2061                                         IRQF_TRIGGER_RISING | IRQF_ONESHOT,
2062                                         "trf7970a", trf);
2063         if (ret) {
2064                 dev_err(trf->dev, "Can't request IRQ#%d: %d\n", spi->irq, ret);
2065                 return ret;
2066         }
2067
2068         mutex_init(&trf->lock);
2069         INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
2070
2071         trf->regulator = devm_regulator_get(&spi->dev, "vin");
2072         if (IS_ERR(trf->regulator)) {
2073                 ret = PTR_ERR(trf->regulator);
2074                 dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret);
2075                 goto err_destroy_lock;
2076         }
2077
2078         ret = regulator_enable(trf->regulator);
2079         if (ret) {
2080                 dev_err(trf->dev, "Can't enable VIN: %d\n", ret);
2081                 goto err_destroy_lock;
2082         }
2083
2084         uvolts = regulator_get_voltage(trf->regulator);
2085         if (uvolts > 4000000)
2086                 trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;
2087
2088         trf->regulator = devm_regulator_get(&spi->dev, "vdd-io");
2089         if (IS_ERR(trf->regulator)) {
2090                 ret = PTR_ERR(trf->regulator);
2091                 dev_err(trf->dev, "Can't get VDD_IO regulator: %d\n", ret);
2092                 goto err_destroy_lock;
2093         }
2094
2095         ret = regulator_enable(trf->regulator);
2096         if (ret) {
2097                 dev_err(trf->dev, "Can't enable VDD_IO: %d\n", ret);
2098                 goto err_destroy_lock;
2099         }
2100
2101         if (regulator_get_voltage(trf->regulator) == 1800000) {
2102                 trf->io_ctrl = TRF7970A_REG_IO_CTRL_IO_LOW;
2103                 dev_dbg(trf->dev, "trf7970a config vdd_io to 1.8V\n");
2104         }
2105
2106         trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,
2107                                                 TRF7970A_SUPPORTED_PROTOCOLS,
2108                                                 NFC_DIGITAL_DRV_CAPS_IN_CRC |
2109                                                 NFC_DIGITAL_DRV_CAPS_TG_CRC, 0,
2110                                                 0);
2111         if (!trf->ddev) {
2112                 dev_err(trf->dev, "Can't allocate NFC digital device\n");
2113                 ret = -ENOMEM;
2114                 goto err_disable_regulator;
2115         }
2116
2117         nfc_digital_set_parent_dev(trf->ddev, trf->dev);
2118         nfc_digital_set_drvdata(trf->ddev, trf);
2119         spi_set_drvdata(spi, trf);
2120
2121         autosuspend_delay = trf7970a_get_autosuspend_delay(np);
2122
2123         pm_runtime_set_autosuspend_delay(trf->dev, autosuspend_delay);
2124         pm_runtime_use_autosuspend(trf->dev);
2125
2126         ret = trf7970a_startup(trf);
2127         if (ret)
2128                 goto err_free_ddev;
2129
2130         ret = nfc_digital_register_device(trf->ddev);
2131         if (ret) {
2132                 dev_err(trf->dev, "Can't register NFC digital device: %d\n",
2133                         ret);
2134                 goto err_shutdown;
2135         }
2136
2137         return 0;
2138
2139 err_shutdown:
2140         trf7970a_shutdown(trf);
2141 err_free_ddev:
2142         nfc_digital_free_device(trf->ddev);
2143 err_disable_regulator:
2144         regulator_disable(trf->regulator);
2145 err_destroy_lock:
2146         mutex_destroy(&trf->lock);
2147         return ret;
2148 }
2149
2150 static int trf7970a_remove(struct spi_device *spi)
2151 {
2152         struct trf7970a *trf = spi_get_drvdata(spi);
2153
2154         mutex_lock(&trf->lock);
2155
2156         trf7970a_shutdown(trf);
2157
2158         mutex_unlock(&trf->lock);
2159
2160         nfc_digital_unregister_device(trf->ddev);
2161         nfc_digital_free_device(trf->ddev);
2162
2163         regulator_disable(trf->regulator);
2164
2165         mutex_destroy(&trf->lock);
2166
2167         return 0;
2168 }
2169
2170 #ifdef CONFIG_PM_SLEEP
2171 static int trf7970a_suspend(struct device *dev)
2172 {
2173         struct spi_device *spi = to_spi_device(dev);
2174         struct trf7970a *trf = spi_get_drvdata(spi);
2175
2176         dev_dbg(dev, "Suspend\n");
2177
2178         mutex_lock(&trf->lock);
2179
2180         trf7970a_shutdown(trf);
2181
2182         mutex_unlock(&trf->lock);
2183
2184         return 0;
2185 }
2186
2187 static int trf7970a_resume(struct device *dev)
2188 {
2189         struct spi_device *spi = to_spi_device(dev);
2190         struct trf7970a *trf = spi_get_drvdata(spi);
2191         int ret;
2192
2193         dev_dbg(dev, "Resume\n");
2194
2195         mutex_lock(&trf->lock);
2196
2197         ret = trf7970a_startup(trf);
2198
2199         mutex_unlock(&trf->lock);
2200
2201         return ret;
2202 }
2203 #endif
2204
2205 #ifdef CONFIG_PM
2206 static int trf7970a_pm_runtime_suspend(struct device *dev)
2207 {
2208         struct spi_device *spi = to_spi_device(dev);
2209         struct trf7970a *trf = spi_get_drvdata(spi);
2210         int ret;
2211
2212         dev_dbg(dev, "Runtime suspend\n");
2213
2214         mutex_lock(&trf->lock);
2215
2216         ret = trf7970a_power_down(trf);
2217
2218         mutex_unlock(&trf->lock);
2219
2220         return ret;
2221 }
2222
2223 static int trf7970a_pm_runtime_resume(struct device *dev)
2224 {
2225         struct spi_device *spi = to_spi_device(dev);
2226         struct trf7970a *trf = spi_get_drvdata(spi);
2227         int ret;
2228
2229         dev_dbg(dev, "Runtime resume\n");
2230
2231         ret = trf7970a_power_up(trf);
2232         if (!ret)
2233                 pm_runtime_mark_last_busy(dev);
2234
2235         return ret;
2236 }
2237 #endif
2238
2239 static const struct dev_pm_ops trf7970a_pm_ops = {
2240         SET_SYSTEM_SLEEP_PM_OPS(trf7970a_suspend, trf7970a_resume)
2241         SET_RUNTIME_PM_OPS(trf7970a_pm_runtime_suspend,
2242                            trf7970a_pm_runtime_resume, NULL)
2243 };
2244
2245 static const struct of_device_id trf7970a_of_match[] = {
2246         {.compatible = "ti,trf7970a",},
2247         {},
2248 };
2249
2250 MODULE_DEVICE_TABLE(of, trf7970a_of_match);
2251
2252 static const struct spi_device_id trf7970a_id_table[] = {
2253         {"trf7970a", 0},
2254         {}
2255 };
2256
2257 MODULE_DEVICE_TABLE(spi, trf7970a_id_table);
2258
2259 static struct spi_driver trf7970a_spi_driver = {
2260         .probe          = trf7970a_probe,
2261         .remove         = trf7970a_remove,
2262         .id_table       = trf7970a_id_table,
2263         .driver = {
2264                 .name           = "trf7970a",
2265                 .of_match_table = of_match_ptr(trf7970a_of_match),
2266                 .pm             = &trf7970a_pm_ops,
2267         },
2268 };
2269
2270 module_spi_driver(trf7970a_spi_driver);
2271
2272 MODULE_AUTHOR("Mark A. Greer <mgreer@animalcreek.com>");
2273 MODULE_LICENSE("GPL v2");
2274 MODULE_DESCRIPTION("TI trf7970a RFID/NFC Transceiver Driver");