1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2012-2020, The Linux Foundation. All rights reserved. 4 */ 5 6 #include <linux/delay.h> 7 #include <drm/drm_print.h> 8 9 #include "dp_reg.h" 10 #include "dp_aux.h" 11 12 enum msm_dp_aux_err { 13 DP_AUX_ERR_NONE, 14 DP_AUX_ERR_ADDR, 15 DP_AUX_ERR_TOUT, 16 DP_AUX_ERR_NACK, 17 DP_AUX_ERR_DEFER, 18 DP_AUX_ERR_NACK_DEFER, 19 DP_AUX_ERR_PHY, 20 }; 21 22 struct dp_aux_private { 23 struct device *dev; 24 struct dp_catalog *catalog; 25 26 struct mutex mutex; 27 struct completion comp; 28 29 enum msm_dp_aux_err aux_error_num; 30 u32 retry_cnt; 31 bool cmd_busy; 32 bool native; 33 bool read; 34 bool no_send_addr; 35 bool no_send_stop; 36 bool initted; 37 bool is_edp; 38 u32 offset; 39 u32 segment; 40 41 struct drm_dp_aux dp_aux; 42 }; 43 44 #define MAX_AUX_RETRIES 5 45 46 static ssize_t dp_aux_write(struct dp_aux_private *aux, 47 struct drm_dp_aux_msg *msg) 48 { 49 u8 data[4]; 50 u32 reg; 51 ssize_t len; 52 u8 *msgdata = msg->buffer; 53 int const AUX_CMD_FIFO_LEN = 128; 54 int i = 0; 55 56 if (aux->read) 57 len = 0; 58 else 59 len = msg->size; 60 61 /* 62 * cmd fifo only has depth of 144 bytes 63 * limit buf length to 128 bytes here 64 */ 65 if (len > AUX_CMD_FIFO_LEN - 4) { 66 DRM_ERROR("buf size greater than allowed size of 128 bytes\n"); 67 return -EINVAL; 68 } 69 70 /* Pack cmd and write to HW */ 71 data[0] = (msg->address >> 16) & 0xf; /* addr[19:16] */ 72 if (aux->read) 73 data[0] |= BIT(4); /* R/W */ 74 75 data[1] = msg->address >> 8; /* addr[15:8] */ 76 data[2] = msg->address; /* addr[7:0] */ 77 data[3] = msg->size - 1; /* len[7:0] */ 78 79 for (i = 0; i < len + 4; i++) { 80 reg = (i < 4) ? data[i] : msgdata[i - 4]; 81 reg <<= DP_AUX_DATA_OFFSET; 82 reg &= DP_AUX_DATA_MASK; 83 reg |= DP_AUX_DATA_WRITE; 84 /* index = 0, write */ 85 if (i == 0) 86 reg |= DP_AUX_DATA_INDEX_WRITE; 87 aux->catalog->aux_data = reg; 88 dp_catalog_aux_write_data(aux->catalog); 89 } 90 91 dp_catalog_aux_clear_trans(aux->catalog, false); 92 dp_catalog_aux_clear_hw_interrupts(aux->catalog); 93 94 reg = 0; /* Transaction number == 1 */ 95 if (!aux->native) { /* i2c */ 96 reg |= DP_AUX_TRANS_CTRL_I2C; 97 98 if (aux->no_send_addr) 99 reg |= DP_AUX_TRANS_CTRL_NO_SEND_ADDR; 100 101 if (aux->no_send_stop) 102 reg |= DP_AUX_TRANS_CTRL_NO_SEND_STOP; 103 } 104 105 reg |= DP_AUX_TRANS_CTRL_GO; 106 aux->catalog->aux_data = reg; 107 dp_catalog_aux_write_trans(aux->catalog); 108 109 return len; 110 } 111 112 static ssize_t dp_aux_cmd_fifo_tx(struct dp_aux_private *aux, 113 struct drm_dp_aux_msg *msg) 114 { 115 ssize_t ret; 116 unsigned long time_left; 117 118 reinit_completion(&aux->comp); 119 120 ret = dp_aux_write(aux, msg); 121 if (ret < 0) 122 return ret; 123 124 time_left = wait_for_completion_timeout(&aux->comp, 125 msecs_to_jiffies(250)); 126 if (!time_left) 127 return -ETIMEDOUT; 128 129 return ret; 130 } 131 132 static ssize_t dp_aux_cmd_fifo_rx(struct dp_aux_private *aux, 133 struct drm_dp_aux_msg *msg) 134 { 135 u32 data; 136 u8 *dp; 137 u32 i, actual_i; 138 u32 len = msg->size; 139 140 dp_catalog_aux_clear_trans(aux->catalog, true); 141 142 data = DP_AUX_DATA_INDEX_WRITE; /* INDEX_WRITE */ 143 data |= DP_AUX_DATA_READ; /* read */ 144 145 aux->catalog->aux_data = data; 146 dp_catalog_aux_write_data(aux->catalog); 147 148 dp = msg->buffer; 149 150 /* discard first byte */ 151 data = dp_catalog_aux_read_data(aux->catalog); 152 153 for (i = 0; i < len; i++) { 154 data = dp_catalog_aux_read_data(aux->catalog); 155 *dp++ = (u8)((data >> DP_AUX_DATA_OFFSET) & 0xff); 156 157 actual_i = (data >> DP_AUX_DATA_INDEX_OFFSET) & 0xFF; 158 if (i != actual_i) 159 break; 160 } 161 162 return i; 163 } 164 165 static void dp_aux_native_handler(struct dp_aux_private *aux, u32 isr) 166 { 167 if (isr & DP_INTR_AUX_I2C_DONE) 168 aux->aux_error_num = DP_AUX_ERR_NONE; 169 else if (isr & DP_INTR_WRONG_ADDR) 170 aux->aux_error_num = DP_AUX_ERR_ADDR; 171 else if (isr & DP_INTR_TIMEOUT) 172 aux->aux_error_num = DP_AUX_ERR_TOUT; 173 if (isr & DP_INTR_NACK_DEFER) 174 aux->aux_error_num = DP_AUX_ERR_NACK; 175 if (isr & DP_INTR_AUX_ERROR) { 176 aux->aux_error_num = DP_AUX_ERR_PHY; 177 dp_catalog_aux_clear_hw_interrupts(aux->catalog); 178 } 179 } 180 181 static void dp_aux_i2c_handler(struct dp_aux_private *aux, u32 isr) 182 { 183 if (isr & DP_INTR_AUX_I2C_DONE) { 184 if (isr & (DP_INTR_I2C_NACK | DP_INTR_I2C_DEFER)) 185 aux->aux_error_num = DP_AUX_ERR_NACK; 186 else 187 aux->aux_error_num = DP_AUX_ERR_NONE; 188 } else { 189 if (isr & DP_INTR_WRONG_ADDR) 190 aux->aux_error_num = DP_AUX_ERR_ADDR; 191 else if (isr & DP_INTR_TIMEOUT) 192 aux->aux_error_num = DP_AUX_ERR_TOUT; 193 if (isr & DP_INTR_NACK_DEFER) 194 aux->aux_error_num = DP_AUX_ERR_NACK_DEFER; 195 if (isr & DP_INTR_I2C_NACK) 196 aux->aux_error_num = DP_AUX_ERR_NACK; 197 if (isr & DP_INTR_I2C_DEFER) 198 aux->aux_error_num = DP_AUX_ERR_DEFER; 199 if (isr & DP_INTR_AUX_ERROR) { 200 aux->aux_error_num = DP_AUX_ERR_PHY; 201 dp_catalog_aux_clear_hw_interrupts(aux->catalog); 202 } 203 } 204 } 205 206 static void dp_aux_update_offset_and_segment(struct dp_aux_private *aux, 207 struct drm_dp_aux_msg *input_msg) 208 { 209 u32 edid_address = 0x50; 210 u32 segment_address = 0x30; 211 bool i2c_read = input_msg->request & 212 (DP_AUX_I2C_READ & DP_AUX_NATIVE_READ); 213 u8 *data; 214 215 if (aux->native || i2c_read || ((input_msg->address != edid_address) && 216 (input_msg->address != segment_address))) 217 return; 218 219 220 data = input_msg->buffer; 221 if (input_msg->address == segment_address) 222 aux->segment = *data; 223 else 224 aux->offset = *data; 225 } 226 227 /** 228 * dp_aux_transfer_helper() - helper function for EDID read transactions 229 * 230 * @aux: DP AUX private structure 231 * @input_msg: input message from DRM upstream APIs 232 * @send_seg: send the segment to sink 233 * 234 * return: void 235 * 236 * This helper function is used to fix EDID reads for non-compliant 237 * sinks that do not handle the i2c middle-of-transaction flag correctly. 238 */ 239 static void dp_aux_transfer_helper(struct dp_aux_private *aux, 240 struct drm_dp_aux_msg *input_msg, 241 bool send_seg) 242 { 243 struct drm_dp_aux_msg helper_msg; 244 u32 message_size = 0x10; 245 u32 segment_address = 0x30; 246 u32 const edid_block_length = 0x80; 247 bool i2c_mot = input_msg->request & DP_AUX_I2C_MOT; 248 bool i2c_read = input_msg->request & 249 (DP_AUX_I2C_READ & DP_AUX_NATIVE_READ); 250 251 if (!i2c_mot || !i2c_read || (input_msg->size == 0)) 252 return; 253 254 /* 255 * Sending the segment value and EDID offset will be performed 256 * from the DRM upstream EDID driver for each block. Avoid 257 * duplicate AUX transactions related to this while reading the 258 * first 16 bytes of each block. 259 */ 260 if (!(aux->offset % edid_block_length) || !send_seg) 261 goto end; 262 263 aux->read = false; 264 aux->cmd_busy = true; 265 aux->no_send_addr = true; 266 aux->no_send_stop = true; 267 268 /* 269 * Send the segment address for every i2c read in which the 270 * middle-of-tranaction flag is set. This is required to support EDID 271 * reads of more than 2 blocks as the segment address is reset to 0 272 * since we are overriding the middle-of-transaction flag for read 273 * transactions. 274 */ 275 276 if (aux->segment) { 277 memset(&helper_msg, 0, sizeof(helper_msg)); 278 helper_msg.address = segment_address; 279 helper_msg.buffer = &aux->segment; 280 helper_msg.size = 1; 281 dp_aux_cmd_fifo_tx(aux, &helper_msg); 282 } 283 284 /* 285 * Send the offset address for every i2c read in which the 286 * middle-of-transaction flag is set. This will ensure that the sink 287 * will update its read pointer and return the correct portion of the 288 * EDID buffer in the subsequent i2c read trasntion triggered in the 289 * native AUX transfer function. 290 */ 291 memset(&helper_msg, 0, sizeof(helper_msg)); 292 helper_msg.address = input_msg->address; 293 helper_msg.buffer = &aux->offset; 294 helper_msg.size = 1; 295 dp_aux_cmd_fifo_tx(aux, &helper_msg); 296 297 end: 298 aux->offset += message_size; 299 if (aux->offset == 0x80 || aux->offset == 0x100) 300 aux->segment = 0x0; /* reset segment at end of block */ 301 } 302 303 /* 304 * This function does the real job to process an AUX transaction. 305 * It will call aux_reset() function to reset the AUX channel, 306 * if the waiting is timeout. 307 */ 308 static ssize_t dp_aux_transfer(struct drm_dp_aux *dp_aux, 309 struct drm_dp_aux_msg *msg) 310 { 311 ssize_t ret; 312 int const aux_cmd_native_max = 16; 313 int const aux_cmd_i2c_max = 128; 314 struct dp_aux_private *aux; 315 316 aux = container_of(dp_aux, struct dp_aux_private, dp_aux); 317 318 aux->native = msg->request & (DP_AUX_NATIVE_WRITE & DP_AUX_NATIVE_READ); 319 320 /* Ignore address only message */ 321 if (msg->size == 0 || !msg->buffer) { 322 msg->reply = aux->native ? 323 DP_AUX_NATIVE_REPLY_ACK : DP_AUX_I2C_REPLY_ACK; 324 return msg->size; 325 } 326 327 /* msg sanity check */ 328 if ((aux->native && msg->size > aux_cmd_native_max) || 329 msg->size > aux_cmd_i2c_max) { 330 DRM_ERROR("%s: invalid msg: size(%zu), request(%x)\n", 331 __func__, msg->size, msg->request); 332 return -EINVAL; 333 } 334 335 mutex_lock(&aux->mutex); 336 if (!aux->initted) { 337 ret = -EIO; 338 goto exit; 339 } 340 341 /* 342 * For eDP it's important to give a reasonably long wait here for HPD 343 * to be asserted. This is because the panel driver may have _just_ 344 * turned on the panel and then tried to do an AUX transfer. The panel 345 * driver has no way of knowing when the panel is ready, so it's up 346 * to us to wait. For DP we never get into this situation so let's 347 * avoid ever doing the extra long wait for DP. 348 */ 349 if (aux->is_edp) { 350 ret = dp_catalog_aux_wait_for_hpd_connect_state(aux->catalog); 351 if (ret) { 352 DRM_DEBUG_DP("Panel not ready for aux transactions\n"); 353 goto exit; 354 } 355 } 356 357 dp_aux_update_offset_and_segment(aux, msg); 358 dp_aux_transfer_helper(aux, msg, true); 359 360 aux->read = msg->request & (DP_AUX_I2C_READ & DP_AUX_NATIVE_READ); 361 aux->cmd_busy = true; 362 363 if (aux->read) { 364 aux->no_send_addr = true; 365 aux->no_send_stop = false; 366 } else { 367 aux->no_send_addr = true; 368 aux->no_send_stop = true; 369 } 370 371 ret = dp_aux_cmd_fifo_tx(aux, msg); 372 if (ret < 0) { 373 if (aux->native) { 374 aux->retry_cnt++; 375 if (!(aux->retry_cnt % MAX_AUX_RETRIES)) 376 dp_catalog_aux_update_cfg(aux->catalog); 377 } 378 /* reset aux if link is in connected state */ 379 if (dp_catalog_link_is_connected(aux->catalog)) 380 dp_catalog_aux_reset(aux->catalog); 381 } else { 382 aux->retry_cnt = 0; 383 switch (aux->aux_error_num) { 384 case DP_AUX_ERR_NONE: 385 if (aux->read) 386 ret = dp_aux_cmd_fifo_rx(aux, msg); 387 msg->reply = aux->native ? DP_AUX_NATIVE_REPLY_ACK : DP_AUX_I2C_REPLY_ACK; 388 break; 389 case DP_AUX_ERR_DEFER: 390 msg->reply = aux->native ? DP_AUX_NATIVE_REPLY_DEFER : DP_AUX_I2C_REPLY_DEFER; 391 break; 392 case DP_AUX_ERR_PHY: 393 case DP_AUX_ERR_ADDR: 394 case DP_AUX_ERR_NACK: 395 case DP_AUX_ERR_NACK_DEFER: 396 msg->reply = aux->native ? DP_AUX_NATIVE_REPLY_NACK : DP_AUX_I2C_REPLY_NACK; 397 break; 398 case DP_AUX_ERR_TOUT: 399 ret = -ETIMEDOUT; 400 break; 401 } 402 } 403 404 aux->cmd_busy = false; 405 406 exit: 407 mutex_unlock(&aux->mutex); 408 409 return ret; 410 } 411 412 void dp_aux_isr(struct drm_dp_aux *dp_aux) 413 { 414 u32 isr; 415 struct dp_aux_private *aux; 416 417 if (!dp_aux) { 418 DRM_ERROR("invalid input\n"); 419 return; 420 } 421 422 aux = container_of(dp_aux, struct dp_aux_private, dp_aux); 423 424 isr = dp_catalog_aux_get_irq(aux->catalog); 425 426 /* no interrupts pending, return immediately */ 427 if (!isr) 428 return; 429 430 if (!aux->cmd_busy) 431 return; 432 433 if (aux->native) 434 dp_aux_native_handler(aux, isr); 435 else 436 dp_aux_i2c_handler(aux, isr); 437 438 complete(&aux->comp); 439 } 440 441 void dp_aux_reconfig(struct drm_dp_aux *dp_aux) 442 { 443 struct dp_aux_private *aux; 444 445 aux = container_of(dp_aux, struct dp_aux_private, dp_aux); 446 447 dp_catalog_aux_update_cfg(aux->catalog); 448 dp_catalog_aux_reset(aux->catalog); 449 } 450 451 void dp_aux_init(struct drm_dp_aux *dp_aux) 452 { 453 struct dp_aux_private *aux; 454 455 if (!dp_aux) { 456 DRM_ERROR("invalid input\n"); 457 return; 458 } 459 460 aux = container_of(dp_aux, struct dp_aux_private, dp_aux); 461 462 mutex_lock(&aux->mutex); 463 464 dp_catalog_aux_enable(aux->catalog, true); 465 aux->retry_cnt = 0; 466 aux->initted = true; 467 468 mutex_unlock(&aux->mutex); 469 } 470 471 void dp_aux_deinit(struct drm_dp_aux *dp_aux) 472 { 473 struct dp_aux_private *aux; 474 475 aux = container_of(dp_aux, struct dp_aux_private, dp_aux); 476 477 mutex_lock(&aux->mutex); 478 479 aux->initted = false; 480 dp_catalog_aux_enable(aux->catalog, false); 481 482 mutex_unlock(&aux->mutex); 483 } 484 485 int dp_aux_register(struct drm_dp_aux *dp_aux) 486 { 487 struct dp_aux_private *aux; 488 int ret; 489 490 if (!dp_aux) { 491 DRM_ERROR("invalid input\n"); 492 return -EINVAL; 493 } 494 495 aux = container_of(dp_aux, struct dp_aux_private, dp_aux); 496 497 aux->dp_aux.name = "dpu_dp_aux"; 498 aux->dp_aux.dev = aux->dev; 499 aux->dp_aux.transfer = dp_aux_transfer; 500 ret = drm_dp_aux_register(&aux->dp_aux); 501 if (ret) { 502 DRM_ERROR("%s: failed to register drm aux: %d\n", __func__, 503 ret); 504 return ret; 505 } 506 507 return 0; 508 } 509 510 void dp_aux_unregister(struct drm_dp_aux *dp_aux) 511 { 512 drm_dp_aux_unregister(dp_aux); 513 } 514 515 struct drm_dp_aux *dp_aux_get(struct device *dev, struct dp_catalog *catalog, 516 bool is_edp) 517 { 518 struct dp_aux_private *aux; 519 520 if (!catalog) { 521 DRM_ERROR("invalid input\n"); 522 return ERR_PTR(-ENODEV); 523 } 524 525 aux = devm_kzalloc(dev, sizeof(*aux), GFP_KERNEL); 526 if (!aux) 527 return ERR_PTR(-ENOMEM); 528 529 init_completion(&aux->comp); 530 aux->cmd_busy = false; 531 aux->is_edp = is_edp; 532 mutex_init(&aux->mutex); 533 534 aux->dev = dev; 535 aux->catalog = catalog; 536 aux->retry_cnt = 0; 537 538 return &aux->dp_aux; 539 } 540 541 void dp_aux_put(struct drm_dp_aux *dp_aux) 542 { 543 struct dp_aux_private *aux; 544 545 if (!dp_aux) 546 return; 547 548 aux = container_of(dp_aux, struct dp_aux_private, dp_aux); 549 550 mutex_destroy(&aux->mutex); 551 552 devm_kfree(aux->dev, aux); 553 } 554