drivers/media/cec/cec-pin.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright 2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
   4  */
   5
   6 #include <linux/delay.h>
   7 #include <linux/slab.h>
   8 #include <linux/sched/types.h>
   9
  10 #include <media/cec-pin.h>
  11 #include "cec-pin-priv.h"
  12
  13 /* All timings are in microseconds */
  14
  15 /* start bit timings */
  16 #define CEC_TIM_START_BIT_LOW           3700
  17 #define CEC_TIM_START_BIT_LOW_MIN       3500
  18 #define CEC_TIM_START_BIT_LOW_MAX       3900
  19 #define CEC_TIM_START_BIT_TOTAL         4500
  20 #define CEC_TIM_START_BIT_TOTAL_MIN     4300
  21 #define CEC_TIM_START_BIT_TOTAL_MAX     4700
  22
  23 /* data bit timings */
  24 #define CEC_TIM_DATA_BIT_0_LOW          1500
  25 #define CEC_TIM_DATA_BIT_0_LOW_MIN      1300
  26 #define CEC_TIM_DATA_BIT_0_LOW_MAX      1700
  27 #define CEC_TIM_DATA_BIT_1_LOW          600
  28 #define CEC_TIM_DATA_BIT_1_LOW_MIN      400
  29 #define CEC_TIM_DATA_BIT_1_LOW_MAX      800
  30 #define CEC_TIM_DATA_BIT_TOTAL          2400
  31 #define CEC_TIM_DATA_BIT_TOTAL_MIN      2050
  32 #define CEC_TIM_DATA_BIT_TOTAL_MAX      2750
  33 /* earliest safe time to sample the bit state */
  34 #define CEC_TIM_DATA_BIT_SAMPLE         850
  35 /* earliest time the bit is back to 1 (T7 + 50) */
  36 #define CEC_TIM_DATA_BIT_HIGH           1750
  37
  38 /* when idle, sample once per millisecond */
  39 #define CEC_TIM_IDLE_SAMPLE             1000
  40 /* when processing the start bit, sample twice per millisecond */
  41 #define CEC_TIM_START_BIT_SAMPLE        500
  42 /* when polling for a state change, sample once every 50 microseconds */
  43 #define CEC_TIM_SAMPLE                  50
  44
  45 #define CEC_TIM_LOW_DRIVE_ERROR         (1.5 * CEC_TIM_DATA_BIT_TOTAL)
  46
  47 /*
  48  * Total data bit time that is too short/long for a valid bit,
  49  * used for error injection.
  50  */
  51 #define CEC_TIM_DATA_BIT_TOTAL_SHORT    1800
  52 #define CEC_TIM_DATA_BIT_TOTAL_LONG     2900
  53
  54 /*
  55  * Total start bit time that is too short/long for a valid bit,
  56  * used for error injection.
  57  */
  58 #define CEC_TIM_START_BIT_TOTAL_SHORT   4100
  59 #define CEC_TIM_START_BIT_TOTAL_LONG    5000
  60
  61 /* Data bits are 0-7, EOM is bit 8 and ACK is bit 9 */
  62 #define EOM_BIT                         8
  63 #define ACK_BIT                         9
  64
  65 struct cec_state {
  66         const char * const name;
  67         unsigned int usecs;
  68 };
  69
  70 static const struct cec_state states[CEC_PIN_STATES] = {
  71         { "Off",                   0 },
  72         { "Idle",                  CEC_TIM_IDLE_SAMPLE },
  73         { "Tx Wait",               CEC_TIM_SAMPLE },
  74         { "Tx Wait for High",      CEC_TIM_IDLE_SAMPLE },
  75         { "Tx Start Bit Low",      CEC_TIM_START_BIT_LOW },
  76         { "Tx Start Bit High",     CEC_TIM_START_BIT_TOTAL - CEC_TIM_START_BIT_LOW },
  77         { "Tx Start Bit High Short", CEC_TIM_START_BIT_TOTAL_SHORT - CEC_TIM_START_BIT_LOW },
  78         { "Tx Start Bit High Long", CEC_TIM_START_BIT_TOTAL_LONG - CEC_TIM_START_BIT_LOW },
  79         { "Tx Start Bit Low Custom", 0 },
  80         { "Tx Start Bit High Custom", 0 },
  81         { "Tx Data 0 Low",         CEC_TIM_DATA_BIT_0_LOW },
  82         { "Tx Data 0 High",        CEC_TIM_DATA_BIT_TOTAL - CEC_TIM_DATA_BIT_0_LOW },
  83         { "Tx Data 0 High Short",  CEC_TIM_DATA_BIT_TOTAL_SHORT - CEC_TIM_DATA_BIT_0_LOW },
  84         { "Tx Data 0 High Long",   CEC_TIM_DATA_BIT_TOTAL_LONG - CEC_TIM_DATA_BIT_0_LOW },
  85         { "Tx Data 1 Low",         CEC_TIM_DATA_BIT_1_LOW },
  86         { "Tx Data 1 High",        CEC_TIM_DATA_BIT_TOTAL - CEC_TIM_DATA_BIT_1_LOW },
  87         { "Tx Data 1 High Short",  CEC_TIM_DATA_BIT_TOTAL_SHORT - CEC_TIM_DATA_BIT_1_LOW },
  88         { "Tx Data 1 High Long",   CEC_TIM_DATA_BIT_TOTAL_LONG - CEC_TIM_DATA_BIT_1_LOW },
  89         { "Tx Data 1 High Pre Sample", CEC_TIM_DATA_BIT_SAMPLE - CEC_TIM_DATA_BIT_1_LOW },
  90         { "Tx Data 1 High Post Sample", CEC_TIM_DATA_BIT_TOTAL - CEC_TIM_DATA_BIT_SAMPLE },
  91         { "Tx Data 1 High Post Sample Short", CEC_TIM_DATA_BIT_TOTAL_SHORT - CEC_TIM_DATA_BIT_SAMPLE },
  92         { "Tx Data 1 High Post Sample Long", CEC_TIM_DATA_BIT_TOTAL_LONG - CEC_TIM_DATA_BIT_SAMPLE },
  93         { "Tx Data Bit Low Custom", 0 },
  94         { "Tx Data Bit High Custom", 0 },
  95         { "Tx Pulse Low Custom",   0 },
  96         { "Tx Pulse High Custom",  0 },
  97         { "Tx Low Drive",          CEC_TIM_LOW_DRIVE_ERROR },
  98         { "Rx Start Bit Low",      CEC_TIM_SAMPLE },
  99         { "Rx Start Bit High",     CEC_TIM_SAMPLE },
 100         { "Rx Data Sample",        CEC_TIM_DATA_BIT_SAMPLE },
 101         { "Rx Data Post Sample",   CEC_TIM_DATA_BIT_HIGH - CEC_TIM_DATA_BIT_SAMPLE },
 102         { "Rx Data Wait for Low",  CEC_TIM_SAMPLE },
 103         { "Rx Ack Low",            CEC_TIM_DATA_BIT_0_LOW },
 104         { "Rx Ack Low Post",       CEC_TIM_DATA_BIT_HIGH - CEC_TIM_DATA_BIT_0_LOW },
 105         { "Rx Ack High Post",      CEC_TIM_DATA_BIT_HIGH },
 106         { "Rx Ack Finish",         CEC_TIM_DATA_BIT_TOTAL_MIN - CEC_TIM_DATA_BIT_HIGH },
 107         { "Rx Low Drive",          CEC_TIM_LOW_DRIVE_ERROR },
 108         { "Rx Irq",                0 },
 109 };
 110
 111 static void cec_pin_update(struct cec_pin *pin, bool v, bool force)
 112 {
 113         if (!force && v == pin->adap->cec_pin_is_high)
 114                 return;
 115
 116         pin->adap->cec_pin_is_high = v;
 117         if (atomic_read(&pin->work_pin_num_events) < CEC_NUM_PIN_EVENTS) {
 118                 u8 ev = v;
 119
 120                 if (pin->work_pin_events_dropped) {
 121                         pin->work_pin_events_dropped = false;
 122                         ev |= CEC_PIN_EVENT_FL_DROPPED;
 123                 }
 124                 pin->work_pin_events[pin->work_pin_events_wr] = ev;
 125                 pin->work_pin_ts[pin->work_pin_events_wr] = ktime_get();
 126                 pin->work_pin_events_wr =
 127                         (pin->work_pin_events_wr + 1) % CEC_NUM_PIN_EVENTS;
 128                 atomic_inc(&pin->work_pin_num_events);
 129         } else {
 130                 pin->work_pin_events_dropped = true;
 131                 pin->work_pin_events_dropped_cnt++;
 132         }
 133         wake_up_interruptible(&pin->kthread_waitq);
 134 }
 135
 136 static bool cec_pin_read(struct cec_pin *pin)
 137 {
 138         bool v = pin->ops->read(pin->adap);
 139
 140         cec_pin_update(pin, v, false);
 141         return v;
 142 }
 143
 144 static void cec_pin_low(struct cec_pin *pin)
 145 {
 146         pin->ops->low(pin->adap);
 147         cec_pin_update(pin, false, false);
 148 }
 149
 150 static bool cec_pin_high(struct cec_pin *pin)
 151 {
 152         pin->ops->high(pin->adap);
 153         return cec_pin_read(pin);
 154 }
 155
 156 static bool rx_error_inj(struct cec_pin *pin, unsigned int mode_offset,
 157                          int arg_idx, u8 *arg)
 158 {
 159 #ifdef CONFIG_CEC_PIN_ERROR_INJ
 160         u16 cmd = cec_pin_rx_error_inj(pin);
 161         u64 e = pin->error_inj[cmd];
 162         unsigned int mode = (e >> mode_offset) & CEC_ERROR_INJ_MODE_MASK;
 163
 164         if (arg_idx >= 0) {
 165                 u8 pos = pin->error_inj_args[cmd][arg_idx];
 166
 167                 if (arg)
 168                         *arg = pos;
 169                 else if (pos != pin->rx_bit)
 170                         return false;
 171         }
 172
 173         switch (mode) {
 174         case CEC_ERROR_INJ_MODE_ONCE:
 175                 pin->error_inj[cmd] &=
 176                         ~(CEC_ERROR_INJ_MODE_MASK << mode_offset);
 177                 return true;
 178         case CEC_ERROR_INJ_MODE_ALWAYS:
 179                 return true;
 180         case CEC_ERROR_INJ_MODE_TOGGLE:
 181                 return pin->rx_toggle;
 182         default:
 183                 return false;
 184         }
 185 #else
 186         return false;
 187 #endif
 188 }
 189
 190 static bool rx_nack(struct cec_pin *pin)
 191 {
 192         return rx_error_inj(pin, CEC_ERROR_INJ_RX_NACK_OFFSET, -1, NULL);
 193 }
 194
 195 static bool rx_low_drive(struct cec_pin *pin)
 196 {
 197         return rx_error_inj(pin, CEC_ERROR_INJ_RX_LOW_DRIVE_OFFSET,
 198                             CEC_ERROR_INJ_RX_LOW_DRIVE_ARG_IDX, NULL);
 199 }
 200
 201 static bool rx_add_byte(struct cec_pin *pin)
 202 {
 203         return rx_error_inj(pin, CEC_ERROR_INJ_RX_ADD_BYTE_OFFSET, -1, NULL);
 204 }
 205
 206 static bool rx_remove_byte(struct cec_pin *pin)
 207 {
 208         return rx_error_inj(pin, CEC_ERROR_INJ_RX_REMOVE_BYTE_OFFSET, -1, NULL);
 209 }
 210
 211 static bool rx_arb_lost(struct cec_pin *pin, u8 *poll)
 212 {
 213         return pin->tx_msg.len == 0 &&
 214                 rx_error_inj(pin, CEC_ERROR_INJ_RX_ARB_LOST_OFFSET,
 215                              CEC_ERROR_INJ_RX_ARB_LOST_ARG_IDX, poll);
 216 }
 217
 218 static bool tx_error_inj(struct cec_pin *pin, unsigned int mode_offset,
 219                          int arg_idx, u8 *arg)
 220 {
 221 #ifdef CONFIG_CEC_PIN_ERROR_INJ
 222         u16 cmd = cec_pin_tx_error_inj(pin);
 223         u64 e = pin->error_inj[cmd];
 224         unsigned int mode = (e >> mode_offset) & CEC_ERROR_INJ_MODE_MASK;
 225
 226         if (arg_idx >= 0) {
 227                 u8 pos = pin->error_inj_args[cmd][arg_idx];
 228
 229                 if (arg)
 230                         *arg = pos;
 231                 else if (pos != pin->tx_bit)
 232                         return false;
 233         }
 234
 235         switch (mode) {
 236         case CEC_ERROR_INJ_MODE_ONCE:
 237                 pin->error_inj[cmd] &=
 238                         ~(CEC_ERROR_INJ_MODE_MASK << mode_offset);
 239                 return true;
 240         case CEC_ERROR_INJ_MODE_ALWAYS:
 241                 return true;
 242         case CEC_ERROR_INJ_MODE_TOGGLE:
 243                 return pin->tx_toggle;
 244         default:
 245                 return false;
 246         }
 247 #else
 248         return false;
 249 #endif
 250 }
 251
 252 static bool tx_no_eom(struct cec_pin *pin)
 253 {
 254         return tx_error_inj(pin, CEC_ERROR_INJ_TX_NO_EOM_OFFSET, -1, NULL);
 255 }
 256
 257 static bool tx_early_eom(struct cec_pin *pin)
 258 {
 259         return tx_error_inj(pin, CEC_ERROR_INJ_TX_EARLY_EOM_OFFSET, -1, NULL);
 260 }
 261
 262 static bool tx_short_bit(struct cec_pin *pin)
 263 {
 264         return tx_error_inj(pin, CEC_ERROR_INJ_TX_SHORT_BIT_OFFSET,
 265                             CEC_ERROR_INJ_TX_SHORT_BIT_ARG_IDX, NULL);
 266 }
 267
 268 static bool tx_long_bit(struct cec_pin *pin)
 269 {
 270         return tx_error_inj(pin, CEC_ERROR_INJ_TX_LONG_BIT_OFFSET,
 271                             CEC_ERROR_INJ_TX_LONG_BIT_ARG_IDX, NULL);
 272 }
 273
 274 static bool tx_custom_bit(struct cec_pin *pin)
 275 {
 276         return tx_error_inj(pin, CEC_ERROR_INJ_TX_CUSTOM_BIT_OFFSET,
 277                             CEC_ERROR_INJ_TX_CUSTOM_BIT_ARG_IDX, NULL);
 278 }
 279
 280 static bool tx_short_start(struct cec_pin *pin)
 281 {
 282         return tx_error_inj(pin, CEC_ERROR_INJ_TX_SHORT_START_OFFSET, -1, NULL);
 283 }
 284
 285 static bool tx_long_start(struct cec_pin *pin)
 286 {
 287         return tx_error_inj(pin, CEC_ERROR_INJ_TX_LONG_START_OFFSET, -1, NULL);
 288 }
 289
 290 static bool tx_custom_start(struct cec_pin *pin)
 291 {
 292         return tx_error_inj(pin, CEC_ERROR_INJ_TX_CUSTOM_START_OFFSET,
 293                             -1, NULL);
 294 }
 295
 296 static bool tx_last_bit(struct cec_pin *pin)
 297 {
 298         return tx_error_inj(pin, CEC_ERROR_INJ_TX_LAST_BIT_OFFSET,
 299                             CEC_ERROR_INJ_TX_LAST_BIT_ARG_IDX, NULL);
 300 }
 301
 302 static u8 tx_add_bytes(struct cec_pin *pin)
 303 {
 304         u8 bytes;
 305
 306         if (tx_error_inj(pin, CEC_ERROR_INJ_TX_ADD_BYTES_OFFSET,
 307                          CEC_ERROR_INJ_TX_ADD_BYTES_ARG_IDX, &bytes))
 308                 return bytes;
 309         return 0;
 310 }
 311
 312 static bool tx_remove_byte(struct cec_pin *pin)
 313 {
 314         return tx_error_inj(pin, CEC_ERROR_INJ_TX_REMOVE_BYTE_OFFSET, -1, NULL);
 315 }
 316
 317 static bool tx_low_drive(struct cec_pin *pin)
 318 {
 319         return tx_error_inj(pin, CEC_ERROR_INJ_TX_LOW_DRIVE_OFFSET,
 320                             CEC_ERROR_INJ_TX_LOW_DRIVE_ARG_IDX, NULL);
 321 }
 322
 323 static void cec_pin_to_idle(struct cec_pin *pin)
 324 {
 325         /*
 326          * Reset all status fields, release the bus and
 327          * go to idle state.
 328          */
 329         pin->rx_bit = pin->tx_bit = 0;
 330         pin->rx_msg.len = 0;
 331         memset(pin->rx_msg.msg, 0, sizeof(pin->rx_msg.msg));
 332         pin->ts = ns_to_ktime(0);
 333         pin->tx_generated_poll = false;
 334         pin->tx_post_eom = false;
 335         if (pin->state >= CEC_ST_TX_WAIT &&
 336             pin->state <= CEC_ST_TX_LOW_DRIVE)
 337                 pin->tx_toggle ^= 1;
 338         if (pin->state >= CEC_ST_RX_START_BIT_LOW &&
 339             pin->state <= CEC_ST_RX_LOW_DRIVE)
 340                 pin->rx_toggle ^= 1;
 341         pin->state = CEC_ST_IDLE;
 342 }
 343
 344 /*
 345  * Handle Transmit-related states
 346  *
 347  * Basic state changes when transmitting:
 348  *
 349  * Idle -> Tx Wait (waiting for the end of signal free time) ->
 350  *      Tx Start Bit Low -> Tx Start Bit High ->
 351  *
 352  *   Regular data bits + EOM:
 353  *      Tx Data 0 Low -> Tx Data 0 High ->
 354  *   or:
 355  *      Tx Data 1 Low -> Tx Data 1 High ->
 356  *
 357  *   First 4 data bits or Ack bit:
 358  *      Tx Data 0 Low -> Tx Data 0 High ->
 359  *   or:
 360  *      Tx Data 1 Low -> Tx Data 1 High -> Tx Data 1 Pre Sample ->
 361  *              Tx Data 1 Post Sample ->
 362  *
 363  *   After the last Ack go to Idle.
 364  *
 365  * If it detects a Low Drive condition then:
 366  *      Tx Wait For High -> Idle
 367  *
 368  * If it loses arbitration, then it switches to state Rx Data Post Sample.
 369  */
 370 static void cec_pin_tx_states(struct cec_pin *pin, ktime_t ts)
 371 {
 372         bool v;
 373         bool is_ack_bit, ack;
 374
 375         switch (pin->state) {
 376         case CEC_ST_TX_WAIT_FOR_HIGH:
 377                 if (cec_pin_read(pin))
 378                         cec_pin_to_idle(pin);
 379                 break;
 380
 381         case CEC_ST_TX_START_BIT_LOW:
 382                 if (tx_short_start(pin)) {
 383                         /*
 384                          * Error Injection: send an invalid (too short)
 385                          * start pulse.
 386                          */
 387                         pin->state = CEC_ST_TX_START_BIT_HIGH_SHORT;
 388                 } else if (tx_long_start(pin)) {
 389                         /*
 390                          * Error Injection: send an invalid (too long)
 391                          * start pulse.
 392                          */
 393                         pin->state = CEC_ST_TX_START_BIT_HIGH_LONG;
 394                 } else {
 395                         pin->state = CEC_ST_TX_START_BIT_HIGH;
 396                 }
 397                 /* Generate start bit */
 398                 cec_pin_high(pin);
 399                 break;
 400
 401         case CEC_ST_TX_START_BIT_LOW_CUSTOM:
 402                 pin->state = CEC_ST_TX_START_BIT_HIGH_CUSTOM;
 403                 /* Generate start bit */
 404                 cec_pin_high(pin);
 405                 break;
 406
 407         case CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE:
 408         case CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE_SHORT:
 409         case CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE_LONG:
 410                 if (pin->tx_nacked) {
 411                         cec_pin_to_idle(pin);
 412                         pin->tx_msg.len = 0;
 413                         if (pin->tx_generated_poll)
 414                                 break;
 415                         pin->work_tx_ts = ts;
 416                         pin->work_tx_status = CEC_TX_STATUS_NACK;
 417                         wake_up_interruptible(&pin->kthread_waitq);
 418                         break;
 419                 }
 420                 /* fall through */
 421         case CEC_ST_TX_DATA_BIT_0_HIGH:
 422         case CEC_ST_TX_DATA_BIT_0_HIGH_SHORT:
 423         case CEC_ST_TX_DATA_BIT_0_HIGH_LONG:
 424         case CEC_ST_TX_DATA_BIT_1_HIGH:
 425         case CEC_ST_TX_DATA_BIT_1_HIGH_SHORT:
 426         case CEC_ST_TX_DATA_BIT_1_HIGH_LONG:
 427                 /*
 428                  * If the read value is 1, then all is OK, otherwise we have a
 429                  * low drive condition.
 430                  *
 431                  * Special case: when we generate a poll message due to an
 432                  * Arbitration Lost error injection, then ignore this since
 433                  * the pin can actually be low in that case.
 434                  */
 435                 if (!cec_pin_read(pin) && !pin->tx_generated_poll) {
 436                         /*
 437                          * It's 0, so someone detected an error and pulled the
 438                          * line low for 1.5 times the nominal bit period.
 439                          */
 440                         pin->tx_msg.len = 0;
 441                         pin->state = CEC_ST_TX_WAIT_FOR_HIGH;
 442                         pin->work_tx_ts = ts;
 443                         pin->work_tx_status = CEC_TX_STATUS_LOW_DRIVE;
 444                         pin->tx_low_drive_cnt++;
 445                         wake_up_interruptible(&pin->kthread_waitq);
 446                         break;
 447                 }
 448                 /* fall through */
 449         case CEC_ST_TX_DATA_BIT_HIGH_CUSTOM:
 450                 if (tx_last_bit(pin)) {
 451                         /* Error Injection: just stop sending after this bit */
 452                         cec_pin_to_idle(pin);
 453                         pin->tx_msg.len = 0;
 454                         if (pin->tx_generated_poll)
 455                                 break;
 456                         pin->work_tx_ts = ts;
 457                         pin->work_tx_status = CEC_TX_STATUS_OK;
 458                         wake_up_interruptible(&pin->kthread_waitq);
 459                         break;
 460                 }
 461                 pin->tx_bit++;
 462                 /* fall through */
 463         case CEC_ST_TX_START_BIT_HIGH:
 464         case CEC_ST_TX_START_BIT_HIGH_SHORT:
 465         case CEC_ST_TX_START_BIT_HIGH_LONG:
 466         case CEC_ST_TX_START_BIT_HIGH_CUSTOM:
 467                 if (tx_low_drive(pin)) {
 468                         /* Error injection: go to low drive */
 469                         cec_pin_low(pin);
 470                         pin->state = CEC_ST_TX_LOW_DRIVE;
 471                         pin->tx_msg.len = 0;
 472                         if (pin->tx_generated_poll)
 473                                 break;
 474                         pin->work_tx_ts = ts;
 475                         pin->work_tx_status = CEC_TX_STATUS_LOW_DRIVE;
 476                         pin->tx_low_drive_cnt++;
 477                         wake_up_interruptible(&pin->kthread_waitq);
 478                         break;
 479                 }
 480                 if (pin->tx_bit / 10 >= pin->tx_msg.len + pin->tx_extra_bytes) {
 481                         cec_pin_to_idle(pin);
 482                         pin->tx_msg.len = 0;
 483                         if (pin->tx_generated_poll)
 484                                 break;
 485                         pin->work_tx_ts = ts;
 486                         pin->work_tx_status = CEC_TX_STATUS_OK;
 487                         wake_up_interruptible(&pin->kthread_waitq);
 488                         break;
 489                 }
 490
 491                 switch (pin->tx_bit % 10) {
 492                 default: {
 493                         /*
 494                          * In the CEC_ERROR_INJ_TX_ADD_BYTES case we transmit
 495                          * extra bytes, so pin->tx_bit / 10 can become >= 16.
 496                          * Generate bit values for those extra bytes instead
 497                          * of reading them from the transmit buffer.
 498                          */
 499                         unsigned int idx = (pin->tx_bit / 10);
 500                         u8 val = idx;
 501
 502                         if (idx < pin->tx_msg.len)
 503                                 val = pin->tx_msg.msg[idx];
 504                         v = val & (1 << (7 - (pin->tx_bit % 10)));
 505
 506                         pin->state = v ? CEC_ST_TX_DATA_BIT_1_LOW :
 507                                          CEC_ST_TX_DATA_BIT_0_LOW;
 508                         break;
 509                 }
 510                 case EOM_BIT: {
 511                         unsigned int tot_len = pin->tx_msg.len +
 512                                                pin->tx_extra_bytes;
 513                         unsigned int tx_byte_idx = pin->tx_bit / 10;
 514
 515                         v = !pin->tx_post_eom && tx_byte_idx == tot_len - 1;
 516                         if (tot_len > 1 && tx_byte_idx == tot_len - 2 &&
 517                             tx_early_eom(pin)) {
 518                                 /* Error injection: set EOM one byte early */
 519                                 v = true;
 520                                 pin->tx_post_eom = true;
 521                         } else if (v && tx_no_eom(pin)) {
 522                                 /* Error injection: no EOM */
 523                                 v = false;
 524                         }
 525                         pin->state = v ? CEC_ST_TX_DATA_BIT_1_LOW :
 526                                          CEC_ST_TX_DATA_BIT_0_LOW;
 527                         break;
 528                 }
 529                 case ACK_BIT:
 530                         pin->state = CEC_ST_TX_DATA_BIT_1_LOW;
 531                         break;
 532                 }
 533                 if (tx_custom_bit(pin))
 534                         pin->state = CEC_ST_TX_DATA_BIT_LOW_CUSTOM;
 535                 cec_pin_low(pin);
 536                 break;
 537
 538         case CEC_ST_TX_DATA_BIT_0_LOW:
 539         case CEC_ST_TX_DATA_BIT_1_LOW:
 540                 v = pin->state == CEC_ST_TX_DATA_BIT_1_LOW;
 541                 is_ack_bit = pin->tx_bit % 10 == ACK_BIT;
 542                 if (v && (pin->tx_bit < 4 || is_ack_bit)) {
 543                         pin->state = CEC_ST_TX_DATA_BIT_1_HIGH_PRE_SAMPLE;
 544                 } else if (!is_ack_bit && tx_short_bit(pin)) {
 545                         /* Error Injection: send an invalid (too short) bit */
 546                         pin->state = v ? CEC_ST_TX_DATA_BIT_1_HIGH_SHORT :
 547                                          CEC_ST_TX_DATA_BIT_0_HIGH_SHORT;
 548                 } else if (!is_ack_bit && tx_long_bit(pin)) {
 549                         /* Error Injection: send an invalid (too long) bit */
 550                         pin->state = v ? CEC_ST_TX_DATA_BIT_1_HIGH_LONG :
 551                                          CEC_ST_TX_DATA_BIT_0_HIGH_LONG;
 552                 } else {
 553                         pin->state = v ? CEC_ST_TX_DATA_BIT_1_HIGH :
 554                                          CEC_ST_TX_DATA_BIT_0_HIGH;
 555                 }
 556                 cec_pin_high(pin);
 557                 break;
 558
 559         case CEC_ST_TX_DATA_BIT_LOW_CUSTOM:
 560                 pin->state = CEC_ST_TX_DATA_BIT_HIGH_CUSTOM;
 561                 cec_pin_high(pin);
 562                 break;
 563
 564         case CEC_ST_TX_DATA_BIT_1_HIGH_PRE_SAMPLE:
 565                 /* Read the CEC value at the sample time */
 566                 v = cec_pin_read(pin);
 567                 is_ack_bit = pin->tx_bit % 10 == ACK_BIT;
 568                 /*
 569                  * If v == 0 and we're within the first 4 bits
 570                  * of the initiator, then someone else started
 571                  * transmitting and we lost the arbitration
 572                  * (i.e. the logical address of the other
 573                  * transmitter has more leading 0 bits in the
 574                  * initiator).
 575                  */
 576                 if (!v && !is_ack_bit && !pin->tx_generated_poll) {
 577                         pin->tx_msg.len = 0;
 578                         pin->work_tx_ts = ts;
 579                         pin->work_tx_status = CEC_TX_STATUS_ARB_LOST;
 580                         wake_up_interruptible(&pin->kthread_waitq);
 581                         pin->rx_bit = pin->tx_bit;
 582                         pin->tx_bit = 0;
 583                         memset(pin->rx_msg.msg, 0, sizeof(pin->rx_msg.msg));
 584                         pin->rx_msg.msg[0] = pin->tx_msg.msg[0];
 585                         pin->rx_msg.msg[0] &= (0xff << (8 - pin->rx_bit));
 586                         pin->rx_msg.len = 0;
 587                         pin->ts = ktime_sub_us(ts, CEC_TIM_DATA_BIT_SAMPLE);
 588                         pin->state = CEC_ST_RX_DATA_POST_SAMPLE;
 589                         pin->rx_bit++;
 590                         break;
 591                 }
 592                 pin->state = CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE;
 593                 if (!is_ack_bit && tx_short_bit(pin)) {
 594                         /* Error Injection: send an invalid (too short) bit */
 595                         pin->state = CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE_SHORT;
 596                 } else if (!is_ack_bit && tx_long_bit(pin)) {
 597                         /* Error Injection: send an invalid (too long) bit */
 598                         pin->state = CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE_LONG;
 599                 }
 600                 if (!is_ack_bit)
 601                         break;
 602                 /* Was the message ACKed? */
 603                 ack = cec_msg_is_broadcast(&pin->tx_msg) ? v : !v;
 604                 if (!ack && !pin->tx_ignore_nack_until_eom &&
 605                     pin->tx_bit / 10 < pin->tx_msg.len && !pin->tx_post_eom) {
 606                         /*
 607                          * Note: the CEC spec is ambiguous regarding
 608                          * what action to take when a NACK appears
 609                          * before the last byte of the payload was
 610                          * transmitted: either stop transmitting
 611                          * immediately, or wait until the last byte
 612                          * was transmitted.
 613                          *
 614                          * Most CEC implementations appear to stop
 615                          * immediately, and that's what we do here
 616                          * as well.
 617                          */
 618                         pin->tx_nacked = true;
 619                 }
 620                 break;
 621
 622         case CEC_ST_TX_PULSE_LOW_CUSTOM:
 623                 cec_pin_high(pin);
 624                 pin->state = CEC_ST_TX_PULSE_HIGH_CUSTOM;
 625                 break;
 626
 627         case CEC_ST_TX_PULSE_HIGH_CUSTOM:
 628                 cec_pin_to_idle(pin);
 629                 break;
 630
 631         default:
 632                 break;
 633         }
 634 }
 635
 636 /*
 637  * Handle Receive-related states
 638  *
 639  * Basic state changes when receiving:
 640  *
 641  *      Rx Start Bit Low -> Rx Start Bit High ->
 642  *   Regular data bits + EOM:
 643  *      Rx Data Sample -> Rx Data Post Sample -> Rx Data High ->
 644  *   Ack bit 0:
 645  *      Rx Ack Low -> Rx Ack Low Post -> Rx Data High ->
 646  *   Ack bit 1:
 647  *      Rx Ack High Post -> Rx Data High ->
 648  *   Ack bit 0 && EOM:
 649  *      Rx Ack Low -> Rx Ack Low Post -> Rx Ack Finish -> Idle
 650  */
 651 static void cec_pin_rx_states(struct cec_pin *pin, ktime_t ts)
 652 {
 653         s32 delta;
 654         bool v;
 655         bool ack;
 656         bool bcast, for_us;
 657         u8 dest;
 658         u8 poll;
 659
 660         switch (pin->state) {
 661         /* Receive states */
 662         case CEC_ST_RX_START_BIT_LOW:
 663                 v = cec_pin_read(pin);
 664                 if (!v)
 665                         break;
 666                 pin->state = CEC_ST_RX_START_BIT_HIGH;
 667                 delta = ktime_us_delta(ts, pin->ts);
 668                 /* Start bit low is too short, go back to idle */
 669                 if (delta < CEC_TIM_START_BIT_LOW_MIN - CEC_TIM_IDLE_SAMPLE) {
 670                         if (!pin->rx_start_bit_low_too_short_cnt++) {
 671                                 pin->rx_start_bit_low_too_short_ts = ktime_to_ns(pin->ts);
 672                                 pin->rx_start_bit_low_too_short_delta = delta;
 673                         }
 674                         cec_pin_to_idle(pin);
 675                         break;
 676                 }
 677                 if (rx_arb_lost(pin, &poll)) {
 678                         cec_msg_init(&pin->tx_msg, poll >> 4, poll & 0xf);
 679                         pin->tx_generated_poll = true;
 680                         pin->tx_extra_bytes = 0;
 681                         pin->state = CEC_ST_TX_START_BIT_HIGH;
 682                         pin->ts = ts;
 683                 }
 684                 break;
 685
 686         case CEC_ST_RX_START_BIT_HIGH:
 687                 v = cec_pin_read(pin);
 688                 delta = ktime_us_delta(ts, pin->ts);
 689                 /*
 690                  * Unfortunately the spec does not specify when to give up
 691                  * and go to idle. We just pick TOTAL_LONG.
 692                  */
 693                 if (v && delta > CEC_TIM_START_BIT_TOTAL_LONG) {
 694                         pin->rx_start_bit_too_long_cnt++;
 695                         cec_pin_to_idle(pin);
 696                         break;
 697                 }
 698                 if (v)
 699                         break;
 700                 /* Start bit is too short, go back to idle */
 701                 if (delta < CEC_TIM_START_BIT_TOTAL_MIN - CEC_TIM_IDLE_SAMPLE) {
 702                         if (!pin->rx_start_bit_too_short_cnt++) {
 703                                 pin->rx_start_bit_too_short_ts = ktime_to_ns(pin->ts);
 704                                 pin->rx_start_bit_too_short_delta = delta;
 705                         }
 706                         cec_pin_to_idle(pin);
 707                         break;
 708                 }
 709                 if (rx_low_drive(pin)) {
 710                         /* Error injection: go to low drive */
 711                         cec_pin_low(pin);
 712                         pin->state = CEC_ST_RX_LOW_DRIVE;
 713                         pin->rx_low_drive_cnt++;
 714                         break;
 715                 }
 716                 pin->state = CEC_ST_RX_DATA_SAMPLE;
 717                 pin->ts = ts;
 718                 pin->rx_eom = false;
 719                 break;
 720
 721         case CEC_ST_RX_DATA_SAMPLE:
 722                 v = cec_pin_read(pin);
 723                 pin->state = CEC_ST_RX_DATA_POST_SAMPLE;
 724                 switch (pin->rx_bit % 10) {
 725                 default:
 726                         if (pin->rx_bit / 10 < CEC_MAX_MSG_SIZE)
 727                                 pin->rx_msg.msg[pin->rx_bit / 10] |=
 728                                         v << (7 - (pin->rx_bit % 10));
 729                         break;
 730                 case EOM_BIT:
 731                         pin->rx_eom = v;
 732                         pin->rx_msg.len = pin->rx_bit / 10 + 1;
 733                         break;
 734                 case ACK_BIT:
 735                         break;
 736                 }
 737                 pin->rx_bit++;
 738                 break;
 739
 740         case CEC_ST_RX_DATA_POST_SAMPLE:
 741                 pin->state = CEC_ST_RX_DATA_WAIT_FOR_LOW;
 742                 break;
 743
 744         case CEC_ST_RX_DATA_WAIT_FOR_LOW:
 745                 v = cec_pin_read(pin);
 746                 delta = ktime_us_delta(ts, pin->ts);
 747                 /*
 748                  * Unfortunately the spec does not specify when to give up
 749                  * and go to idle. We just pick TOTAL_LONG.
 750                  */
 751                 if (v && delta > CEC_TIM_DATA_BIT_TOTAL_LONG) {
 752                         pin->rx_data_bit_too_long_cnt++;
 753                         cec_pin_to_idle(pin);
 754                         break;
 755                 }
 756                 if (v)
 757                         break;
 758
 759                 if (rx_low_drive(pin)) {
 760                         /* Error injection: go to low drive */
 761                         cec_pin_low(pin);
 762                         pin->state = CEC_ST_RX_LOW_DRIVE;
 763                         pin->rx_low_drive_cnt++;
 764                         break;
 765                 }
 766
 767                 /*
 768                  * Go to low drive state when the total bit time is
 769                  * too short.
 770                  */
 771                 if (delta < CEC_TIM_DATA_BIT_TOTAL_MIN) {
 772                         if (!pin->rx_data_bit_too_short_cnt++) {
 773                                 pin->rx_data_bit_too_short_ts = ktime_to_ns(pin->ts);
 774                                 pin->rx_data_bit_too_short_delta = delta;
 775                         }
 776                         cec_pin_low(pin);
 777                         pin->state = CEC_ST_RX_LOW_DRIVE;
 778                         pin->rx_low_drive_cnt++;
 779                         break;
 780                 }
 781                 pin->ts = ts;
 782                 if (pin->rx_bit % 10 != 9) {
 783                         pin->state = CEC_ST_RX_DATA_SAMPLE;
 784                         break;
 785                 }
 786
 787                 dest = cec_msg_destination(&pin->rx_msg);
 788                 bcast = dest == CEC_LOG_ADDR_BROADCAST;
 789                 /* for_us == broadcast or directed to us */
 790                 for_us = bcast || (pin->la_mask & (1 << dest));
 791                 /* ACK bit value */
 792                 ack = bcast ? 1 : !for_us;
 793
 794                 if (for_us && rx_nack(pin)) {
 795                         /* Error injection: toggle the ACK bit */
 796                         ack = !ack;
 797                 }
 798
 799                 if (ack) {
 800                         /* No need to write to the bus, just wait */
 801                         pin->state = CEC_ST_RX_ACK_HIGH_POST;
 802                         break;
 803                 }
 804                 cec_pin_low(pin);
 805                 pin->state = CEC_ST_RX_ACK_LOW;
 806                 break;
 807
 808         case CEC_ST_RX_ACK_LOW:
 809                 cec_pin_high(pin);
 810                 pin->state = CEC_ST_RX_ACK_LOW_POST;
 811                 break;
 812
 813         case CEC_ST_RX_ACK_LOW_POST:
 814         case CEC_ST_RX_ACK_HIGH_POST:
 815                 v = cec_pin_read(pin);
 816                 if (v && pin->rx_eom) {
 817                         pin->work_rx_msg = pin->rx_msg;
 818                         pin->work_rx_msg.rx_ts = ktime_to_ns(ts);
 819                         wake_up_interruptible(&pin->kthread_waitq);
 820                         pin->ts = ts;
 821                         pin->state = CEC_ST_RX_ACK_FINISH;
 822                         break;
 823                 }
 824                 pin->rx_bit++;
 825                 pin->state = CEC_ST_RX_DATA_WAIT_FOR_LOW;
 826                 break;
 827
 828         case CEC_ST_RX_ACK_FINISH:
 829                 cec_pin_to_idle(pin);
 830                 break;
 831
 832         default:
 833                 break;
 834         }
 835 }
 836
 837 /*
 838  * Main timer function
 839  *
 840  */
 841 static enum hrtimer_restart cec_pin_timer(struct hrtimer *timer)
 842 {
 843         struct cec_pin *pin = container_of(timer, struct cec_pin, timer);
 844         struct cec_adapter *adap = pin->adap;
 845         ktime_t ts;
 846         s32 delta;
 847         u32 usecs;
 848
 849         ts = ktime_get();
 850         if (ktime_to_ns(pin->timer_ts)) {
 851                 delta = ktime_us_delta(ts, pin->timer_ts);
 852                 pin->timer_cnt++;
 853                 if (delta > 100 && pin->state != CEC_ST_IDLE) {
 854                         /* Keep track of timer overruns */
 855                         pin->timer_sum_overrun += delta;
 856                         pin->timer_100ms_overruns++;
 857                         if (delta > 300)
 858                                 pin->timer_300ms_overruns++;
 859                         if (delta > pin->timer_max_overrun)
 860                                 pin->timer_max_overrun = delta;
 861                 }
 862         }
 863         if (adap->monitor_pin_cnt)
 864                 cec_pin_read(pin);
 865
 866         if (pin->wait_usecs) {
 867                 /*
 868                  * If we are monitoring the pin, then we have to
 869                  * sample at regular intervals.
 870                  */
 871                 if (pin->wait_usecs > 150) {
 872                         pin->wait_usecs -= 100;
 873                         pin->timer_ts = ktime_add_us(ts, 100);
 874                         hrtimer_forward_now(timer, ns_to_ktime(100000));
 875                         return HRTIMER_RESTART;
 876                 }
 877                 if (pin->wait_usecs > 100) {
 878                         pin->wait_usecs /= 2;
 879                         pin->timer_ts = ktime_add_us(ts, pin->wait_usecs);
 880                         hrtimer_forward_now(timer,
 881                                         ns_to_ktime(pin->wait_usecs * 1000));
 882                         return HRTIMER_RESTART;
 883                 }
 884                 pin->timer_ts = ktime_add_us(ts, pin->wait_usecs);
 885                 hrtimer_forward_now(timer,
 886                                     ns_to_ktime(pin->wait_usecs * 1000));
 887                 pin->wait_usecs = 0;
 888                 return HRTIMER_RESTART;
 889         }
 890
 891         switch (pin->state) {
 892         /* Transmit states */
 893         case CEC_ST_TX_WAIT_FOR_HIGH:
 894         case CEC_ST_TX_START_BIT_LOW:
 895         case CEC_ST_TX_START_BIT_HIGH:
 896         case CEC_ST_TX_START_BIT_HIGH_SHORT:
 897         case CEC_ST_TX_START_BIT_HIGH_LONG:
 898         case CEC_ST_TX_START_BIT_LOW_CUSTOM:
 899         case CEC_ST_TX_START_BIT_HIGH_CUSTOM:
 900         case CEC_ST_TX_DATA_BIT_0_LOW:
 901         case CEC_ST_TX_DATA_BIT_0_HIGH:
 902         case CEC_ST_TX_DATA_BIT_0_HIGH_SHORT:
 903         case CEC_ST_TX_DATA_BIT_0_HIGH_LONG:
 904         case CEC_ST_TX_DATA_BIT_1_LOW:
 905         case CEC_ST_TX_DATA_BIT_1_HIGH:
 906         case CEC_ST_TX_DATA_BIT_1_HIGH_SHORT:
 907         case CEC_ST_TX_DATA_BIT_1_HIGH_LONG:
 908         case CEC_ST_TX_DATA_BIT_1_HIGH_PRE_SAMPLE:
 909         case CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE:
 910         case CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE_SHORT:
 911         case CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE_LONG:
 912         case CEC_ST_TX_DATA_BIT_LOW_CUSTOM:
 913         case CEC_ST_TX_DATA_BIT_HIGH_CUSTOM:
 914         case CEC_ST_TX_PULSE_LOW_CUSTOM:
 915         case CEC_ST_TX_PULSE_HIGH_CUSTOM:
 916                 cec_pin_tx_states(pin, ts);
 917                 break;
 918
 919         /* Receive states */
 920         case CEC_ST_RX_START_BIT_LOW:
 921         case CEC_ST_RX_START_BIT_HIGH:
 922         case CEC_ST_RX_DATA_SAMPLE:
 923         case CEC_ST_RX_DATA_POST_SAMPLE:
 924         case CEC_ST_RX_DATA_WAIT_FOR_LOW:
 925         case CEC_ST_RX_ACK_LOW:
 926         case CEC_ST_RX_ACK_LOW_POST:
 927         case CEC_ST_RX_ACK_HIGH_POST:
 928         case CEC_ST_RX_ACK_FINISH:
 929                 cec_pin_rx_states(pin, ts);
 930                 break;
 931
 932         case CEC_ST_IDLE:
 933         case CEC_ST_TX_WAIT:
 934                 if (!cec_pin_high(pin)) {
 935                         /* Start bit, switch to receive state */
 936                         pin->ts = ts;
 937                         pin->state = CEC_ST_RX_START_BIT_LOW;
 938                         /*
 939                          * If a transmit is pending, then that transmit should
 940                          * use a signal free time of no more than
 941                          * CEC_SIGNAL_FREE_TIME_NEW_INITIATOR since it will
 942                          * have a new initiator due to the receive that is now
 943                          * starting.
 944                          */
 945                         if (pin->tx_msg.len && pin->tx_signal_free_time >
 946                             CEC_SIGNAL_FREE_TIME_NEW_INITIATOR)
 947                                 pin->tx_signal_free_time =
 948                                         CEC_SIGNAL_FREE_TIME_NEW_INITIATOR;
 949                         break;
 950                 }
 951                 if (ktime_to_ns(pin->ts) == 0)
 952                         pin->ts = ts;
 953                 if (pin->tx_msg.len) {
 954                         /*
 955                          * Check if the bus has been free for long enough
 956                          * so we can kick off the pending transmit.
 957                          */
 958                         delta = ktime_us_delta(ts, pin->ts);
 959                         if (delta / CEC_TIM_DATA_BIT_TOTAL >
 960                             pin->tx_signal_free_time) {
 961                                 pin->tx_nacked = false;
 962                                 if (tx_custom_start(pin))
 963                                         pin->state = CEC_ST_TX_START_BIT_LOW_CUSTOM;
 964                                 else
 965                                         pin->state = CEC_ST_TX_START_BIT_LOW;
 966                                 /* Generate start bit */
 967                                 cec_pin_low(pin);
 968                                 break;
 969                         }
 970                         if (delta / CEC_TIM_DATA_BIT_TOTAL >
 971                             pin->tx_signal_free_time - 1)
 972                                 pin->state = CEC_ST_TX_WAIT;
 973                         break;
 974                 }
 975                 if (pin->tx_custom_pulse && pin->state == CEC_ST_IDLE) {
 976                         pin->tx_custom_pulse = false;
 977                         /* Generate custom pulse */
 978                         cec_pin_low(pin);
 979                         pin->state = CEC_ST_TX_PULSE_LOW_CUSTOM;
 980                         break;
 981                 }
 982                 if (pin->state != CEC_ST_IDLE || pin->ops->enable_irq == NULL ||
 983                     pin->enable_irq_failed || adap->is_configuring ||
 984                     adap->is_configured || adap->monitor_all_cnt)
 985                         break;
 986                 /* Switch to interrupt mode */
 987                 atomic_set(&pin->work_irq_change, CEC_PIN_IRQ_ENABLE);
 988                 pin->state = CEC_ST_RX_IRQ;
 989                 wake_up_interruptible(&pin->kthread_waitq);
 990                 return HRTIMER_NORESTART;
 991
 992         case CEC_ST_TX_LOW_DRIVE:
 993         case CEC_ST_RX_LOW_DRIVE:
 994                 cec_pin_high(pin);
 995                 cec_pin_to_idle(pin);
 996                 break;
 997
 998         default:
 999                 break;
1000         }
1001
1002         switch (pin->state) {
1003         case CEC_ST_TX_START_BIT_LOW_CUSTOM:
1004         case CEC_ST_TX_DATA_BIT_LOW_CUSTOM:
1005         case CEC_ST_TX_PULSE_LOW_CUSTOM:
1006                 usecs = pin->tx_custom_low_usecs;
1007                 break;
1008         case CEC_ST_TX_START_BIT_HIGH_CUSTOM:
1009         case CEC_ST_TX_DATA_BIT_HIGH_CUSTOM:
1010         case CEC_ST_TX_PULSE_HIGH_CUSTOM:
1011                 usecs = pin->tx_custom_high_usecs;
1012                 break;
1013         default:
1014                 usecs = states[pin->state].usecs;
1015                 break;
1016         }
1017
1018         if (!adap->monitor_pin_cnt || usecs <= 150) {
1019                 pin->wait_usecs = 0;
1020                 pin->timer_ts = ktime_add_us(ts, usecs);
1021                 hrtimer_forward_now(timer,
1022                                 ns_to_ktime(usecs * 1000));
1023                 return HRTIMER_RESTART;
1024         }
1025         pin->wait_usecs = usecs - 100;
1026         pin->timer_ts = ktime_add_us(ts, 100);
1027         hrtimer_forward_now(timer, ns_to_ktime(100000));
1028         return HRTIMER_RESTART;
1029 }
1030
1031 static int cec_pin_thread_func(void *_adap)
1032 {
1033         struct cec_adapter *adap = _adap;
1034         struct cec_pin *pin = adap->pin;
1035
1036         for (;;) {
1037                 wait_event_interruptible(pin->kthread_waitq,
1038                         kthread_should_stop() ||
1039                         pin->work_rx_msg.len ||
1040                         pin->work_tx_status ||
1041                         atomic_read(&pin->work_irq_change) ||
1042                         atomic_read(&pin->work_pin_num_events));
1043
1044                 if (pin->work_rx_msg.len) {
1045                         struct cec_msg *msg = &pin->work_rx_msg;
1046
1047                         if (msg->len > 1 && msg->len < CEC_MAX_MSG_SIZE &&
1048                             rx_add_byte(pin)) {
1049                                 /* Error injection: add byte to the message */
1050                                 msg->msg[msg->len++] = 0x55;
1051                         }
1052                         if (msg->len > 2 && rx_remove_byte(pin)) {
1053                                 /* Error injection: remove byte from message */
1054                                 msg->len--;
1055                         }
1056                         if (msg->len > CEC_MAX_MSG_SIZE)
1057                                 msg->len = CEC_MAX_MSG_SIZE;
1058                         cec_received_msg_ts(adap, msg,
1059                                 ns_to_ktime(pin->work_rx_msg.rx_ts));
1060                         msg->len = 0;
1061                 }
1062                 if (pin->work_tx_status) {
1063                         unsigned int tx_status = pin->work_tx_status;
1064
1065                         pin->work_tx_status = 0;
1066                         cec_transmit_attempt_done_ts(adap, tx_status,
1067                                                      pin->work_tx_ts);
1068                 }
1069
1070                 while (atomic_read(&pin->work_pin_num_events)) {
1071                         unsigned int idx = pin->work_pin_events_rd;
1072                         u8 v = pin->work_pin_events[idx];
1073
1074                         cec_queue_pin_cec_event(adap,
1075                                                 v & CEC_PIN_EVENT_FL_IS_HIGH,
1076                                                 v & CEC_PIN_EVENT_FL_DROPPED,
1077                                                 pin->work_pin_ts[idx]);
1078                         pin->work_pin_events_rd = (idx + 1) % CEC_NUM_PIN_EVENTS;
1079                         atomic_dec(&pin->work_pin_num_events);
1080                 }
1081
1082                 switch (atomic_xchg(&pin->work_irq_change,
1083                                     CEC_PIN_IRQ_UNCHANGED)) {
1084                 case CEC_PIN_IRQ_DISABLE:
1085                         pin->ops->disable_irq(adap);
1086                         cec_pin_high(pin);
1087                         cec_pin_to_idle(pin);
1088                         hrtimer_start(&pin->timer, ns_to_ktime(0),
1089                                       HRTIMER_MODE_REL);
1090                         break;
1091                 case CEC_PIN_IRQ_ENABLE:
1092                         pin->enable_irq_failed = !pin->ops->enable_irq(adap);
1093                         if (pin->enable_irq_failed) {
1094                                 cec_pin_to_idle(pin);
1095                                 hrtimer_start(&pin->timer, ns_to_ktime(0),
1096                                               HRTIMER_MODE_REL);
1097                         }
1098                         break;
1099                 default:
1100                         break;
1101                 }
1102
1103                 if (kthread_should_stop())
1104                         break;
1105         }
1106         return 0;
1107 }
1108
1109 static int cec_pin_adap_enable(struct cec_adapter *adap, bool enable)
1110 {
1111         struct cec_pin *pin = adap->pin;
1112
1113         pin->enabled = enable;
1114         if (enable) {
1115                 atomic_set(&pin->work_pin_num_events, 0);
1116                 pin->work_pin_events_rd = pin->work_pin_events_wr = 0;
1117                 pin->work_pin_events_dropped = false;
1118                 cec_pin_read(pin);
1119                 cec_pin_to_idle(pin);
1120                 pin->tx_msg.len = 0;
1121                 pin->timer_ts = ns_to_ktime(0);
1122                 atomic_set(&pin->work_irq_change, CEC_PIN_IRQ_UNCHANGED);
1123                 pin->kthread = kthread_run(cec_pin_thread_func, adap,
1124                                            "cec-pin");
1125                 if (IS_ERR(pin->kthread)) {
1126                         pr_err("cec-pin: kernel_thread() failed\n");
1127                         return PTR_ERR(pin->kthread);
1128                 }
1129                 hrtimer_start(&pin->timer, ns_to_ktime(0),
1130                               HRTIMER_MODE_REL);
1131         } else {
1132                 if (pin->ops->disable_irq)
1133                         pin->ops->disable_irq(adap);
1134                 hrtimer_cancel(&pin->timer);
1135                 kthread_stop(pin->kthread);
1136                 cec_pin_read(pin);
1137                 cec_pin_to_idle(pin);
1138                 pin->state = CEC_ST_OFF;
1139         }
1140         return 0;
1141 }
1142
1143 static int cec_pin_adap_log_addr(struct cec_adapter *adap, u8 log_addr)
1144 {
1145         struct cec_pin *pin = adap->pin;
1146
1147         if (log_addr == CEC_LOG_ADDR_INVALID)
1148                 pin->la_mask = 0;
1149         else
1150                 pin->la_mask |= (1 << log_addr);
1151         return 0;
1152 }
1153
1154 void cec_pin_start_timer(struct cec_pin *pin)
1155 {
1156         if (pin->state != CEC_ST_RX_IRQ)
1157                 return;
1158
1159         atomic_set(&pin->work_irq_change, CEC_PIN_IRQ_UNCHANGED);
1160         pin->ops->disable_irq(pin->adap);
1161         cec_pin_high(pin);
1162         cec_pin_to_idle(pin);
1163         hrtimer_start(&pin->timer, ns_to_ktime(0), HRTIMER_MODE_REL);
1164 }
1165
1166 static int cec_pin_adap_transmit(struct cec_adapter *adap, u8 attempts,
1167                                       u32 signal_free_time, struct cec_msg *msg)
1168 {
1169         struct cec_pin *pin = adap->pin;
1170
1171         /*
1172          * If a receive is in progress, then this transmit should use
1173          * a signal free time of max CEC_SIGNAL_FREE_TIME_NEW_INITIATOR
1174          * since when it starts transmitting it will have a new initiator.
1175          */
1176         if (pin->state != CEC_ST_IDLE &&
1177             signal_free_time > CEC_SIGNAL_FREE_TIME_NEW_INITIATOR)
1178                 signal_free_time = CEC_SIGNAL_FREE_TIME_NEW_INITIATOR;
1179
1180         pin->tx_signal_free_time = signal_free_time;
1181         pin->tx_extra_bytes = 0;
1182         pin->tx_msg = *msg;
1183         if (msg->len > 1) {
1184                 /* Error injection: add byte to the message */
1185                 pin->tx_extra_bytes = tx_add_bytes(pin);
1186         }
1187         if (msg->len > 2 && tx_remove_byte(pin)) {
1188                 /* Error injection: remove byte from the message */
1189                 pin->tx_msg.len--;
1190         }
1191         pin->work_tx_status = 0;
1192         pin->tx_bit = 0;
1193         cec_pin_start_timer(pin);
1194         return 0;
1195 }
1196
1197 static void cec_pin_adap_status(struct cec_adapter *adap,
1198                                        struct seq_file *file)
1199 {
1200         struct cec_pin *pin = adap->pin;
1201
1202         seq_printf(file, "state: %s\n", states[pin->state].name);
1203         seq_printf(file, "tx_bit: %d\n", pin->tx_bit);
1204         seq_printf(file, "rx_bit: %d\n", pin->rx_bit);
1205         seq_printf(file, "cec pin: %d\n", pin->ops->read(adap));
1206         seq_printf(file, "cec pin events dropped: %u\n",
1207                    pin->work_pin_events_dropped_cnt);
1208         seq_printf(file, "irq failed: %d\n", pin->enable_irq_failed);
1209         if (pin->timer_100ms_overruns) {
1210                 seq_printf(file, "timer overruns > 100ms: %u of %u\n",
1211                            pin->timer_100ms_overruns, pin->timer_cnt);
1212                 seq_printf(file, "timer overruns > 300ms: %u of %u\n",
1213                            pin->timer_300ms_overruns, pin->timer_cnt);
1214                 seq_printf(file, "max timer overrun: %u usecs\n",
1215                            pin->timer_max_overrun);
1216                 seq_printf(file, "avg timer overrun: %u usecs\n",
1217                            pin->timer_sum_overrun / pin->timer_100ms_overruns);
1218         }
1219         if (pin->rx_start_bit_low_too_short_cnt)
1220                 seq_printf(file,
1221                            "rx start bit low too short: %u (delta %u, ts %llu)\n",
1222                            pin->rx_start_bit_low_too_short_cnt,
1223                            pin->rx_start_bit_low_too_short_delta,
1224                            pin->rx_start_bit_low_too_short_ts);
1225         if (pin->rx_start_bit_too_short_cnt)
1226                 seq_printf(file,
1227                            "rx start bit too short: %u (delta %u, ts %llu)\n",
1228                            pin->rx_start_bit_too_short_cnt,
1229                            pin->rx_start_bit_too_short_delta,
1230                            pin->rx_start_bit_too_short_ts);
1231         if (pin->rx_start_bit_too_long_cnt)
1232                 seq_printf(file, "rx start bit too long: %u\n",
1233                            pin->rx_start_bit_too_long_cnt);
1234         if (pin->rx_data_bit_too_short_cnt)
1235                 seq_printf(file,
1236                            "rx data bit too short: %u (delta %u, ts %llu)\n",
1237                            pin->rx_data_bit_too_short_cnt,
1238                            pin->rx_data_bit_too_short_delta,
1239                            pin->rx_data_bit_too_short_ts);
1240         if (pin->rx_data_bit_too_long_cnt)
1241                 seq_printf(file, "rx data bit too long: %u\n",
1242                            pin->rx_data_bit_too_long_cnt);
1243         seq_printf(file, "rx initiated low drive: %u\n", pin->rx_low_drive_cnt);
1244         seq_printf(file, "tx detected low drive: %u\n", pin->tx_low_drive_cnt);
1245         pin->work_pin_events_dropped_cnt = 0;
1246         pin->timer_cnt = 0;
1247         pin->timer_100ms_overruns = 0;
1248         pin->timer_300ms_overruns = 0;
1249         pin->timer_max_overrun = 0;
1250         pin->timer_sum_overrun = 0;
1251         pin->rx_start_bit_low_too_short_cnt = 0;
1252         pin->rx_start_bit_too_short_cnt = 0;
1253         pin->rx_start_bit_too_long_cnt = 0;
1254         pin->rx_data_bit_too_short_cnt = 0;
1255         pin->rx_data_bit_too_long_cnt = 0;
1256         pin->rx_low_drive_cnt = 0;
1257         pin->tx_low_drive_cnt = 0;
1258         if (pin->ops->status)
1259                 pin->ops->status(adap, file);
1260 }
1261
1262 static int cec_pin_adap_monitor_all_enable(struct cec_adapter *adap,
1263                                                   bool enable)
1264 {
1265         struct cec_pin *pin = adap->pin;
1266
1267         pin->monitor_all = enable;
1268         return 0;
1269 }
1270
1271 static void cec_pin_adap_free(struct cec_adapter *adap)
1272 {
1273         struct cec_pin *pin = adap->pin;
1274
1275         if (pin->ops->free)
1276                 pin->ops->free(adap);
1277         adap->pin = NULL;
1278         kfree(pin);
1279 }
1280
1281 void cec_pin_changed(struct cec_adapter *adap, bool value)
1282 {
1283         struct cec_pin *pin = adap->pin;
1284
1285         cec_pin_update(pin, value, false);
1286         if (!value && (adap->is_configuring || adap->is_configured ||
1287                        adap->monitor_all_cnt))
1288                 atomic_set(&pin->work_irq_change, CEC_PIN_IRQ_DISABLE);
1289 }
1290 EXPORT_SYMBOL_GPL(cec_pin_changed);
1291
1292 static const struct cec_adap_ops cec_pin_adap_ops = {
1293         .adap_enable = cec_pin_adap_enable,
1294         .adap_monitor_all_enable = cec_pin_adap_monitor_all_enable,
1295         .adap_log_addr = cec_pin_adap_log_addr,
1296         .adap_transmit = cec_pin_adap_transmit,
1297         .adap_status = cec_pin_adap_status,
1298         .adap_free = cec_pin_adap_free,
1299 #ifdef CONFIG_CEC_PIN_ERROR_INJ
1300         .error_inj_parse_line = cec_pin_error_inj_parse_line,
1301         .error_inj_show = cec_pin_error_inj_show,
1302 #endif
1303 };
1304
1305 struct cec_adapter *cec_pin_allocate_adapter(const struct cec_pin_ops *pin_ops,
1306                                         void *priv, const char *name, u32 caps)
1307 {
1308         struct cec_adapter *adap;
1309         struct cec_pin *pin = kzalloc(sizeof(*pin), GFP_KERNEL);
1310
1311         if (pin == NULL)
1312                 return ERR_PTR(-ENOMEM);
1313         pin->ops = pin_ops;
1314         hrtimer_init(&pin->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1315         pin->timer.function = cec_pin_timer;
1316         init_waitqueue_head(&pin->kthread_waitq);
1317         pin->tx_custom_low_usecs = CEC_TIM_CUSTOM_DEFAULT;
1318         pin->tx_custom_high_usecs = CEC_TIM_CUSTOM_DEFAULT;
1319
1320         adap = cec_allocate_adapter(&cec_pin_adap_ops, priv, name,
1321                             caps | CEC_CAP_MONITOR_ALL | CEC_CAP_MONITOR_PIN,
1322                             CEC_MAX_LOG_ADDRS);
1323
1324         if (IS_ERR(adap)) {
1325                 kfree(pin);
1326                 return adap;
1327         }
1328
1329         adap->pin = pin;
1330         pin->adap = adap;
1331         cec_pin_update(pin, cec_pin_high(pin), true);
1332         return adap;
1333 }
1334 EXPORT_SYMBOL_GPL(cec_pin_allocate_adapter);