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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (c) 2012-2020, The Linux Foundation. All rights reserved.4 */5 6#include <linux/delay.h>7#include <linux/phy/phy.h>8#include <drm/drm_print.h>9 10#include "dp_reg.h"11#include "dp_aux.h"12 13enum msm_dp_aux_err {14 DP_AUX_ERR_NONE,15 DP_AUX_ERR_ADDR,16 DP_AUX_ERR_TOUT,17 DP_AUX_ERR_NACK,18 DP_AUX_ERR_DEFER,19 DP_AUX_ERR_NACK_DEFER,20 DP_AUX_ERR_PHY,21};22 23struct dp_aux_private {24 struct device *dev;25 struct dp_catalog *catalog;26 27 struct phy *phy;28 29 struct mutex mutex;30 struct completion comp;31 32 enum msm_dp_aux_err aux_error_num;33 u32 retry_cnt;34 bool cmd_busy;35 bool native;36 bool read;37 bool no_send_addr;38 bool no_send_stop;39 bool initted;40 bool is_edp;41 bool enable_xfers;42 u32 offset;43 u32 segment;44 45 struct drm_dp_aux dp_aux;46};47 48#define MAX_AUX_RETRIES 549 50static ssize_t dp_aux_write(struct dp_aux_private *aux,51 struct drm_dp_aux_msg *msg)52{53 u8 data[4];54 u32 reg;55 ssize_t len;56 u8 *msgdata = msg->buffer;57 int const AUX_CMD_FIFO_LEN = 128;58 int i = 0;59 60 if (aux->read)61 len = 0;62 else63 len = msg->size;64 65 /*66 * cmd fifo only has depth of 144 bytes67 * limit buf length to 128 bytes here68 */69 if (len > AUX_CMD_FIFO_LEN - 4) {70 DRM_ERROR("buf size greater than allowed size of 128 bytes\n");71 return -EINVAL;72 }73 74 /* Pack cmd and write to HW */75 data[0] = (msg->address >> 16) & 0xf; /* addr[19:16] */76 if (aux->read)77 data[0] |= BIT(4); /* R/W */78 79 data[1] = msg->address >> 8; /* addr[15:8] */80 data[2] = msg->address; /* addr[7:0] */81 data[3] = msg->size - 1; /* len[7:0] */82 83 for (i = 0; i < len + 4; i++) {84 reg = (i < 4) ? data[i] : msgdata[i - 4];85 reg <<= DP_AUX_DATA_OFFSET;86 reg &= DP_AUX_DATA_MASK;87 reg |= DP_AUX_DATA_WRITE;88 /* index = 0, write */89 if (i == 0)90 reg |= DP_AUX_DATA_INDEX_WRITE;91 dp_catalog_aux_write_data(aux->catalog, reg);92 }93 94 dp_catalog_aux_clear_trans(aux->catalog, false);95 dp_catalog_aux_clear_hw_interrupts(aux->catalog);96 97 reg = 0; /* Transaction number == 1 */98 if (!aux->native) { /* i2c */99 reg |= DP_AUX_TRANS_CTRL_I2C;100 101 if (aux->no_send_addr)102 reg |= DP_AUX_TRANS_CTRL_NO_SEND_ADDR;103 104 if (aux->no_send_stop)105 reg |= DP_AUX_TRANS_CTRL_NO_SEND_STOP;106 }107 108 reg |= DP_AUX_TRANS_CTRL_GO;109 dp_catalog_aux_write_trans(aux->catalog, reg);110 111 return len;112}113 114static ssize_t dp_aux_cmd_fifo_tx(struct dp_aux_private *aux,115 struct drm_dp_aux_msg *msg)116{117 ssize_t ret;118 unsigned long time_left;119 120 reinit_completion(&aux->comp);121 122 ret = dp_aux_write(aux, msg);123 if (ret < 0)124 return ret;125 126 time_left = wait_for_completion_timeout(&aux->comp,127 msecs_to_jiffies(250));128 if (!time_left)129 return -ETIMEDOUT;130 131 return ret;132}133 134static ssize_t dp_aux_cmd_fifo_rx(struct dp_aux_private *aux,135 struct drm_dp_aux_msg *msg)136{137 u32 data;138 u8 *dp;139 u32 i, actual_i;140 u32 len = msg->size;141 142 dp_catalog_aux_clear_trans(aux->catalog, true);143 144 data = DP_AUX_DATA_INDEX_WRITE; /* INDEX_WRITE */145 data |= DP_AUX_DATA_READ; /* read */146 147 dp_catalog_aux_write_data(aux->catalog, data);148 149 dp = msg->buffer;150 151 /* discard first byte */152 data = dp_catalog_aux_read_data(aux->catalog);153 154 for (i = 0; i < len; i++) {155 data = dp_catalog_aux_read_data(aux->catalog);156 *dp++ = (u8)((data >> DP_AUX_DATA_OFFSET) & 0xff);157 158 actual_i = (data >> DP_AUX_DATA_INDEX_OFFSET) & 0xFF;159 if (i != actual_i)160 break;161 }162 163 return i;164}165 166static void dp_aux_update_offset_and_segment(struct dp_aux_private *aux,167 struct drm_dp_aux_msg *input_msg)168{169 u32 edid_address = 0x50;170 u32 segment_address = 0x30;171 bool i2c_read = input_msg->request &172 (DP_AUX_I2C_READ & DP_AUX_NATIVE_READ);173 u8 *data;174 175 if (aux->native || i2c_read || ((input_msg->address != edid_address) &&176 (input_msg->address != segment_address)))177 return;178 179 180 data = input_msg->buffer;181 if (input_msg->address == segment_address)182 aux->segment = *data;183 else184 aux->offset = *data;185}186 187/**188 * dp_aux_transfer_helper() - helper function for EDID read transactions189 *190 * @aux: DP AUX private structure191 * @input_msg: input message from DRM upstream APIs192 * @send_seg: send the segment to sink193 *194 * return: void195 *196 * This helper function is used to fix EDID reads for non-compliant197 * sinks that do not handle the i2c middle-of-transaction flag correctly.198 */199static void dp_aux_transfer_helper(struct dp_aux_private *aux,200 struct drm_dp_aux_msg *input_msg,201 bool send_seg)202{203 struct drm_dp_aux_msg helper_msg;204 u32 message_size = 0x10;205 u32 segment_address = 0x30;206 u32 const edid_block_length = 0x80;207 bool i2c_mot = input_msg->request & DP_AUX_I2C_MOT;208 bool i2c_read = input_msg->request &209 (DP_AUX_I2C_READ & DP_AUX_NATIVE_READ);210 211 if (!i2c_mot || !i2c_read || (input_msg->size == 0))212 return;213 214 /*215 * Sending the segment value and EDID offset will be performed216 * from the DRM upstream EDID driver for each block. Avoid217 * duplicate AUX transactions related to this while reading the218 * first 16 bytes of each block.219 */220 if (!(aux->offset % edid_block_length) || !send_seg)221 goto end;222 223 aux->read = false;224 aux->cmd_busy = true;225 aux->no_send_addr = true;226 aux->no_send_stop = true;227 228 /*229 * Send the segment address for every i2c read in which the230 * middle-of-tranaction flag is set. This is required to support EDID231 * reads of more than 2 blocks as the segment address is reset to 0232 * since we are overriding the middle-of-transaction flag for read233 * transactions.234 */235 236 if (aux->segment) {237 memset(&helper_msg, 0, sizeof(helper_msg));238 helper_msg.address = segment_address;239 helper_msg.buffer = &aux->segment;240 helper_msg.size = 1;241 dp_aux_cmd_fifo_tx(aux, &helper_msg);242 }243 244 /*245 * Send the offset address for every i2c read in which the246 * middle-of-transaction flag is set. This will ensure that the sink247 * will update its read pointer and return the correct portion of the248 * EDID buffer in the subsequent i2c read trasntion triggered in the249 * native AUX transfer function.250 */251 memset(&helper_msg, 0, sizeof(helper_msg));252 helper_msg.address = input_msg->address;253 helper_msg.buffer = &aux->offset;254 helper_msg.size = 1;255 dp_aux_cmd_fifo_tx(aux, &helper_msg);256 257end:258 aux->offset += message_size;259 if (aux->offset == 0x80 || aux->offset == 0x100)260 aux->segment = 0x0; /* reset segment at end of block */261}262 263/*264 * This function does the real job to process an AUX transaction.265 * It will call aux_reset() function to reset the AUX channel,266 * if the waiting is timeout.267 */268static ssize_t dp_aux_transfer(struct drm_dp_aux *dp_aux,269 struct drm_dp_aux_msg *msg)270{271 ssize_t ret;272 int const aux_cmd_native_max = 16;273 int const aux_cmd_i2c_max = 128;274 struct dp_aux_private *aux;275 276 aux = container_of(dp_aux, struct dp_aux_private, dp_aux);277 278 aux->native = msg->request & (DP_AUX_NATIVE_WRITE & DP_AUX_NATIVE_READ);279 280 /* Ignore address only message */281 if (msg->size == 0 || !msg->buffer) {282 msg->reply = aux->native ?283 DP_AUX_NATIVE_REPLY_ACK : DP_AUX_I2C_REPLY_ACK;284 return msg->size;285 }286 287 /* msg sanity check */288 if ((aux->native && msg->size > aux_cmd_native_max) ||289 msg->size > aux_cmd_i2c_max) {290 DRM_ERROR("%s: invalid msg: size(%zu), request(%x)\n",291 __func__, msg->size, msg->request);292 return -EINVAL;293 }294 295 ret = pm_runtime_resume_and_get(dp_aux->dev);296 if (ret)297 return ret;298 299 mutex_lock(&aux->mutex);300 if (!aux->initted) {301 ret = -EIO;302 goto exit;303 }304 305 /*306 * If we're using DP and an external display isn't connected then the307 * transfer won't succeed. Return right away. If we don't do this we308 * can end up with long timeouts if someone tries to access the DP AUX309 * character device when no DP device is connected.310 */311 if (!aux->is_edp && !aux->enable_xfers) {312 ret = -ENXIO;313 goto exit;314 }315 316 dp_aux_update_offset_and_segment(aux, msg);317 dp_aux_transfer_helper(aux, msg, true);318 319 aux->read = msg->request & (DP_AUX_I2C_READ & DP_AUX_NATIVE_READ);320 aux->cmd_busy = true;321 322 if (aux->read) {323 aux->no_send_addr = true;324 aux->no_send_stop = false;325 } else {326 aux->no_send_addr = true;327 aux->no_send_stop = true;328 }329 330 ret = dp_aux_cmd_fifo_tx(aux, msg);331 if (ret < 0) {332 if (aux->native) {333 aux->retry_cnt++;334 if (!(aux->retry_cnt % MAX_AUX_RETRIES))335 phy_calibrate(aux->phy);336 }337 /* reset aux if link is in connected state */338 if (dp_catalog_link_is_connected(aux->catalog))339 dp_catalog_aux_reset(aux->catalog);340 } else {341 aux->retry_cnt = 0;342 switch (aux->aux_error_num) {343 case DP_AUX_ERR_NONE:344 if (aux->read)345 ret = dp_aux_cmd_fifo_rx(aux, msg);346 msg->reply = aux->native ? DP_AUX_NATIVE_REPLY_ACK : DP_AUX_I2C_REPLY_ACK;347 break;348 case DP_AUX_ERR_DEFER:349 msg->reply = aux->native ? DP_AUX_NATIVE_REPLY_DEFER : DP_AUX_I2C_REPLY_DEFER;350 break;351 case DP_AUX_ERR_PHY:352 case DP_AUX_ERR_ADDR:353 case DP_AUX_ERR_NACK:354 case DP_AUX_ERR_NACK_DEFER:355 msg->reply = aux->native ? DP_AUX_NATIVE_REPLY_NACK : DP_AUX_I2C_REPLY_NACK;356 break;357 case DP_AUX_ERR_TOUT:358 ret = -ETIMEDOUT;359 break;360 }361 }362 363 aux->cmd_busy = false;364 365exit:366 mutex_unlock(&aux->mutex);367 pm_runtime_put_sync(dp_aux->dev);368 369 return ret;370}371 372irqreturn_t dp_aux_isr(struct drm_dp_aux *dp_aux)373{374 u32 isr;375 struct dp_aux_private *aux;376 377 if (!dp_aux) {378 DRM_ERROR("invalid input\n");379 return IRQ_NONE;380 }381 382 aux = container_of(dp_aux, struct dp_aux_private, dp_aux);383 384 isr = dp_catalog_aux_get_irq(aux->catalog);385 386 /* no interrupts pending, return immediately */387 if (!isr)388 return IRQ_NONE;389 390 if (!aux->cmd_busy) {391 DRM_ERROR("Unexpected DP AUX IRQ %#010x when not busy\n", isr);392 return IRQ_NONE;393 }394 395 /*396 * The logic below assumes only one error bit is set (other than "done"397 * which can apparently be set at the same time as some of the other398 * bits). Warn if more than one get set so we know we need to improve399 * the logic.400 */401 if (hweight32(isr & ~DP_INTR_AUX_XFER_DONE) > 1)402 DRM_WARN("Some DP AUX interrupts unhandled: %#010x\n", isr);403 404 if (isr & DP_INTR_AUX_ERROR) {405 aux->aux_error_num = DP_AUX_ERR_PHY;406 dp_catalog_aux_clear_hw_interrupts(aux->catalog);407 } else if (isr & DP_INTR_NACK_DEFER) {408 aux->aux_error_num = DP_AUX_ERR_NACK_DEFER;409 } else if (isr & DP_INTR_WRONG_ADDR) {410 aux->aux_error_num = DP_AUX_ERR_ADDR;411 } else if (isr & DP_INTR_TIMEOUT) {412 aux->aux_error_num = DP_AUX_ERR_TOUT;413 } else if (!aux->native && (isr & DP_INTR_I2C_NACK)) {414 aux->aux_error_num = DP_AUX_ERR_NACK;415 } else if (!aux->native && (isr & DP_INTR_I2C_DEFER)) {416 if (isr & DP_INTR_AUX_XFER_DONE)417 aux->aux_error_num = DP_AUX_ERR_NACK;418 else419 aux->aux_error_num = DP_AUX_ERR_DEFER;420 } else if (isr & DP_INTR_AUX_XFER_DONE) {421 aux->aux_error_num = DP_AUX_ERR_NONE;422 } else {423 DRM_WARN("Unexpected interrupt: %#010x\n", isr);424 return IRQ_NONE;425 }426 427 complete(&aux->comp);428 429 return IRQ_HANDLED;430}431 432void dp_aux_enable_xfers(struct drm_dp_aux *dp_aux, bool enabled)433{434 struct dp_aux_private *aux;435 436 aux = container_of(dp_aux, struct dp_aux_private, dp_aux);437 aux->enable_xfers = enabled;438}439 440void dp_aux_reconfig(struct drm_dp_aux *dp_aux)441{442 struct dp_aux_private *aux;443 444 aux = container_of(dp_aux, struct dp_aux_private, dp_aux);445 446 phy_calibrate(aux->phy);447 dp_catalog_aux_reset(aux->catalog);448}449 450void dp_aux_init(struct drm_dp_aux *dp_aux)451{452 struct dp_aux_private *aux;453 454 if (!dp_aux) {455 DRM_ERROR("invalid input\n");456 return;457 }458 459 aux = container_of(dp_aux, struct dp_aux_private, dp_aux);460 461 mutex_lock(&aux->mutex);462 463 dp_catalog_aux_enable(aux->catalog, true);464 aux->retry_cnt = 0;465 aux->initted = true;466 467 mutex_unlock(&aux->mutex);468}469 470void dp_aux_deinit(struct drm_dp_aux *dp_aux)471{472 struct dp_aux_private *aux;473 474 aux = container_of(dp_aux, struct dp_aux_private, dp_aux);475 476 mutex_lock(&aux->mutex);477 478 aux->initted = false;479 dp_catalog_aux_enable(aux->catalog, false);480 481 mutex_unlock(&aux->mutex);482}483 484int dp_aux_register(struct drm_dp_aux *dp_aux)485{486 int ret;487 488 if (!dp_aux) {489 DRM_ERROR("invalid input\n");490 return -EINVAL;491 }492 493 ret = drm_dp_aux_register(dp_aux);494 if (ret) {495 DRM_ERROR("%s: failed to register drm aux: %d\n", __func__,496 ret);497 return ret;498 }499 500 return 0;501}502 503void dp_aux_unregister(struct drm_dp_aux *dp_aux)504{505 drm_dp_aux_unregister(dp_aux);506}507 508static int dp_wait_hpd_asserted(struct drm_dp_aux *dp_aux,509 unsigned long wait_us)510{511 int ret;512 struct dp_aux_private *aux;513 514 aux = container_of(dp_aux, struct dp_aux_private, dp_aux);515 516 ret = pm_runtime_resume_and_get(aux->dev);517 if (ret)518 return ret;519 520 ret = dp_catalog_aux_wait_for_hpd_connect_state(aux->catalog, wait_us);521 pm_runtime_put_sync(aux->dev);522 523 return ret;524}525 526struct drm_dp_aux *dp_aux_get(struct device *dev, struct dp_catalog *catalog,527 struct phy *phy,528 bool is_edp)529{530 struct dp_aux_private *aux;531 532 if (!catalog) {533 DRM_ERROR("invalid input\n");534 return ERR_PTR(-ENODEV);535 }536 537 aux = devm_kzalloc(dev, sizeof(*aux), GFP_KERNEL);538 if (!aux)539 return ERR_PTR(-ENOMEM);540 541 init_completion(&aux->comp);542 aux->cmd_busy = false;543 aux->is_edp = is_edp;544 mutex_init(&aux->mutex);545 546 aux->dev = dev;547 aux->catalog = catalog;548 aux->phy = phy;549 aux->retry_cnt = 0;550 551 /*552 * Use the drm_dp_aux_init() to use the aux adapter553 * before registering AUX with the DRM device so that554 * msm eDP panel can be detected by generic_dep_panel_probe().555 */556 aux->dp_aux.name = "dpu_dp_aux";557 aux->dp_aux.dev = dev;558 aux->dp_aux.transfer = dp_aux_transfer;559 aux->dp_aux.wait_hpd_asserted = dp_wait_hpd_asserted;560 drm_dp_aux_init(&aux->dp_aux);561 562 return &aux->dp_aux;563}564 565void dp_aux_put(struct drm_dp_aux *dp_aux)566{567 struct dp_aux_private *aux;568 569 if (!dp_aux)570 return;571 572 aux = container_of(dp_aux, struct dp_aux_private, dp_aux);573 574 mutex_destroy(&aux->mutex);575 576 devm_kfree(aux->dev, aux);577}578