drivers/nfc/trf7970a.c

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