drivers/net/ethernet/amd/xgbe/xgbe-i2c.c

   1 /*
   2  * AMD 10Gb Ethernet driver
   3  *
   4  * This file is available to you under your choice of the following two
   5  * licenses:
   6  *
   7  * License 1: GPLv2
   8  *
   9  * Copyright (c) 2016 Advanced Micro Devices, Inc.
  10  *
  11  * This file is free software; you may copy, redistribute and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation, either version 2 of the License, or (at
  14  * your option) any later version.
  15  *
  16  * This file is distributed in the hope that it will be useful, but
  17  * WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  19  * General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  23  *
  24  * This file incorporates work covered by the following copyright and
  25  * permission notice:
  26  *     The Synopsys DWC ETHER XGMAC Software Driver and documentation
  27  *     (hereinafter "Software") is an unsupported proprietary work of Synopsys,
  28  *     Inc. unless otherwise expressly agreed to in writing between Synopsys
  29  *     and you.
  30  *
  31  *     The Software IS NOT an item of Licensed Software or Licensed Product
  32  *     under any End User Software License Agreement or Agreement for Licensed
  33  *     Product with Synopsys or any supplement thereto.  Permission is hereby
  34  *     granted, free of charge, to any person obtaining a copy of this software
  35  *     annotated with this license and the Software, to deal in the Software
  36  *     without restriction, including without limitation the rights to use,
  37  *     copy, modify, merge, publish, distribute, sublicense, and/or sell copies
  38  *     of the Software, and to permit persons to whom the Software is furnished
  39  *     to do so, subject to the following conditions:
  40  *
  41  *     The above copyright notice and this permission notice shall be included
  42  *     in all copies or substantial portions of the Software.
  43  *
  44  *     THIS SOFTWARE IS BEING DISTRIBUTED BY SYNOPSYS SOLELY ON AN "AS IS"
  45  *     BASIS AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  46  *     TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  47  *     PARTICULAR PURPOSE ARE HEREBY DISCLAIMED. IN NO EVENT SHALL SYNOPSYS
  48  *     BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  49  *     CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  50  *     SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  51  *     INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  52  *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  53  *     ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  54  *     THE POSSIBILITY OF SUCH DAMAGE.
  55  *
  56  *
  57  * License 2: Modified BSD
  58  *
  59  * Copyright (c) 2016 Advanced Micro Devices, Inc.
  60  * All rights reserved.
  61  *
  62  * Redistribution and use in source and binary forms, with or without
  63  * modification, are permitted provided that the following conditions are met:
  64  *     * Redistributions of source code must retain the above copyright
  65  *       notice, this list of conditions and the following disclaimer.
  66  *     * Redistributions in binary form must reproduce the above copyright
  67  *       notice, this list of conditions and the following disclaimer in the
  68  *       documentation and/or other materials provided with the distribution.
  69  *     * Neither the name of Advanced Micro Devices, Inc. nor the
  70  *       names of its contributors may be used to endorse or promote products
  71  *       derived from this software without specific prior written permission.
  72  *
  73  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  74  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  75  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  76  * ARE DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
  77  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  78  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  79  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  80  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  81  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  82  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  83  *
  84  * This file incorporates work covered by the following copyright and
  85  * permission notice:
  86  *     The Synopsys DWC ETHER XGMAC Software Driver and documentation
  87  *     (hereinafter "Software") is an unsupported proprietary work of Synopsys,
  88  *     Inc. unless otherwise expressly agreed to in writing between Synopsys
  89  *     and you.
  90  *
  91  *     The Software IS NOT an item of Licensed Software or Licensed Product
  92  *     under any End User Software License Agreement or Agreement for Licensed
  93  *     Product with Synopsys or any supplement thereto.  Permission is hereby
  94  *     granted, free of charge, to any person obtaining a copy of this software
  95  *     annotated with this license and the Software, to deal in the Software
  96  *     without restriction, including without limitation the rights to use,
  97  *     copy, modify, merge, publish, distribute, sublicense, and/or sell copies
  98  *     of the Software, and to permit persons to whom the Software is furnished
  99  *     to do so, subject to the following conditions:
 100  *
 101  *     The above copyright notice and this permission notice shall be included
 102  *     in all copies or substantial portions of the Software.
 103  *
 104  *     THIS SOFTWARE IS BEING DISTRIBUTED BY SYNOPSYS SOLELY ON AN "AS IS"
 105  *     BASIS AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 106  *     TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 107  *     PARTICULAR PURPOSE ARE HEREBY DISCLAIMED. IN NO EVENT SHALL SYNOPSYS
 108  *     BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 109  *     CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 110  *     SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 111  *     INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 112  *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 113  *     ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 114  *     THE POSSIBILITY OF SUCH DAMAGE.
 115  */
 116
 117 #include <linux/module.h>
 118 #include <linux/interrupt.h>
 119 #include <linux/kmod.h>
 120 #include <linux/delay.h>
 121 #include <linux/completion.h>
 122 #include <linux/mutex.h>
 123
 124 #include "xgbe.h"
 125 #include "xgbe-common.h"
 126
 127 #define XGBE_ABORT_COUNT        500
 128 #define XGBE_DISABLE_COUNT      1000
 129
 130 #define XGBE_STD_SPEED          1
 131
 132 #define XGBE_INTR_RX_FULL       BIT(IC_RAW_INTR_STAT_RX_FULL_INDEX)
 133 #define XGBE_INTR_TX_EMPTY      BIT(IC_RAW_INTR_STAT_TX_EMPTY_INDEX)
 134 #define XGBE_INTR_TX_ABRT       BIT(IC_RAW_INTR_STAT_TX_ABRT_INDEX)
 135 #define XGBE_INTR_STOP_DET      BIT(IC_RAW_INTR_STAT_STOP_DET_INDEX)
 136 #define XGBE_DEFAULT_INT_MASK   (XGBE_INTR_RX_FULL  |   \
 137                                  XGBE_INTR_TX_EMPTY |   \
 138                                  XGBE_INTR_TX_ABRT  |   \
 139                                  XGBE_INTR_STOP_DET)
 140
 141 #define XGBE_I2C_READ           BIT(8)
 142 #define XGBE_I2C_STOP           BIT(9)
 143
 144 static int xgbe_i2c_abort(struct xgbe_prv_data *pdata)
 145 {
 146         unsigned int wait = XGBE_ABORT_COUNT;
 147
 148         /* Must be enabled to recognize the abort request */
 149         XI2C_IOWRITE_BITS(pdata, IC_ENABLE, EN, 1);
 150
 151         /* Issue the abort */
 152         XI2C_IOWRITE_BITS(pdata, IC_ENABLE, ABORT, 1);
 153
 154         while (wait--) {
 155                 if (!XI2C_IOREAD_BITS(pdata, IC_ENABLE, ABORT))
 156                         return 0;
 157
 158                 usleep_range(500, 600);
 159         }
 160
 161         return -EBUSY;
 162 }
 163
 164 static int xgbe_i2c_set_enable(struct xgbe_prv_data *pdata, bool enable)
 165 {
 166         unsigned int wait = XGBE_DISABLE_COUNT;
 167         unsigned int mode = enable ? 1 : 0;
 168
 169         while (wait--) {
 170                 XI2C_IOWRITE_BITS(pdata, IC_ENABLE, EN, mode);
 171                 if (XI2C_IOREAD_BITS(pdata, IC_ENABLE_STATUS, EN) == mode)
 172                         return 0;
 173
 174                 usleep_range(100, 110);
 175         }
 176
 177         return -EBUSY;
 178 }
 179
 180 static int xgbe_i2c_disable(struct xgbe_prv_data *pdata)
 181 {
 182         unsigned int ret;
 183
 184         ret = xgbe_i2c_set_enable(pdata, false);
 185         if (ret) {
 186                 /* Disable failed, try an abort */
 187                 ret = xgbe_i2c_abort(pdata);
 188                 if (ret)
 189                         return ret;
 190
 191                 /* Abort succeeded, try to disable again */
 192                 ret = xgbe_i2c_set_enable(pdata, false);
 193         }
 194
 195         return ret;
 196 }
 197
 198 static int xgbe_i2c_enable(struct xgbe_prv_data *pdata)
 199 {
 200         return xgbe_i2c_set_enable(pdata, true);
 201 }
 202
 203 static void xgbe_i2c_clear_all_interrupts(struct xgbe_prv_data *pdata)
 204 {
 205         XI2C_IOREAD(pdata, IC_CLR_INTR);
 206 }
 207
 208 static void xgbe_i2c_disable_interrupts(struct xgbe_prv_data *pdata)
 209 {
 210         XI2C_IOWRITE(pdata, IC_INTR_MASK, 0);
 211 }
 212
 213 static void xgbe_i2c_enable_interrupts(struct xgbe_prv_data *pdata)
 214 {
 215         XI2C_IOWRITE(pdata, IC_INTR_MASK, XGBE_DEFAULT_INT_MASK);
 216 }
 217
 218 static void xgbe_i2c_write(struct xgbe_prv_data *pdata)
 219 {
 220         struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
 221         unsigned int tx_slots;
 222         unsigned int cmd;
 223
 224         /* Configured to never receive Rx overflows, so fill up Tx fifo */
 225         tx_slots = pdata->i2c.tx_fifo_size - XI2C_IOREAD(pdata, IC_TXFLR);
 226         while (tx_slots && state->tx_len) {
 227                 if (state->op->cmd == XGBE_I2C_CMD_READ)
 228                         cmd = XGBE_I2C_READ;
 229                 else
 230                         cmd = *state->tx_buf++;
 231
 232                 if (state->tx_len == 1)
 233                         XI2C_SET_BITS(cmd, IC_DATA_CMD, STOP, 1);
 234
 235                 XI2C_IOWRITE(pdata, IC_DATA_CMD, cmd);
 236
 237                 tx_slots--;
 238                 state->tx_len--;
 239         }
 240
 241         /* No more Tx operations, so ignore TX_EMPTY and return */
 242         if (!state->tx_len)
 243                 XI2C_IOWRITE_BITS(pdata, IC_INTR_MASK, TX_EMPTY, 0);
 244 }
 245
 246 static void xgbe_i2c_read(struct xgbe_prv_data *pdata)
 247 {
 248         struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
 249         unsigned int rx_slots;
 250
 251         /* Anything to be read? */
 252         if (state->op->cmd != XGBE_I2C_CMD_READ)
 253                 return;
 254
 255         rx_slots = XI2C_IOREAD(pdata, IC_RXFLR);
 256         while (rx_slots && state->rx_len) {
 257                 *state->rx_buf++ = XI2C_IOREAD(pdata, IC_DATA_CMD);
 258                 state->rx_len--;
 259                 rx_slots--;
 260         }
 261 }
 262
 263 static void xgbe_i2c_clear_isr_interrupts(struct xgbe_prv_data *pdata,
 264                                           unsigned int isr)
 265 {
 266         struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
 267
 268         if (isr & XGBE_INTR_TX_ABRT) {
 269                 state->tx_abort_source = XI2C_IOREAD(pdata, IC_TX_ABRT_SOURCE);
 270                 XI2C_IOREAD(pdata, IC_CLR_TX_ABRT);
 271         }
 272
 273         if (isr & XGBE_INTR_STOP_DET)
 274                 XI2C_IOREAD(pdata, IC_CLR_STOP_DET);
 275 }
 276
 277 static void xgbe_i2c_isr_task(unsigned long data)
 278 {
 279         struct xgbe_prv_data *pdata = (struct xgbe_prv_data *)data;
 280         struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
 281         unsigned int isr;
 282
 283         isr = XI2C_IOREAD(pdata, IC_RAW_INTR_STAT);
 284         if (!isr)
 285                 goto reissue_check;
 286
 287         netif_dbg(pdata, intr, pdata->netdev,
 288                   "I2C interrupt received: status=%#010x\n", isr);
 289
 290         xgbe_i2c_clear_isr_interrupts(pdata, isr);
 291
 292         if (isr & XGBE_INTR_TX_ABRT) {
 293                 netif_dbg(pdata, link, pdata->netdev,
 294                           "I2C TX_ABRT received (%#010x) for target %#04x\n",
 295                           state->tx_abort_source, state->op->target);
 296
 297                 xgbe_i2c_disable_interrupts(pdata);
 298
 299                 state->ret = -EIO;
 300                 goto out;
 301         }
 302
 303         /* Check for data in the Rx fifo */
 304         xgbe_i2c_read(pdata);
 305
 306         /* Fill up the Tx fifo next */
 307         xgbe_i2c_write(pdata);
 308
 309 out:
 310         /* Complete on an error or STOP condition */
 311         if (state->ret || XI2C_GET_BITS(isr, IC_RAW_INTR_STAT, STOP_DET))
 312                 complete(&pdata->i2c_complete);
 313
 314 reissue_check:
 315         /* Reissue interrupt if status is not clear */
 316         if (pdata->vdata->irq_reissue_support)
 317                 XP_IOWRITE(pdata, XP_INT_REISSUE_EN, 1 << 2);
 318 }
 319
 320 static irqreturn_t xgbe_i2c_isr(int irq, void *data)
 321 {
 322         struct xgbe_prv_data *pdata = (struct xgbe_prv_data *)data;
 323
 324         if (pdata->isr_as_tasklet)
 325                 tasklet_schedule(&pdata->tasklet_i2c);
 326         else
 327                 xgbe_i2c_isr_task((unsigned long)pdata);
 328
 329         return IRQ_HANDLED;
 330 }
 331
 332 static void xgbe_i2c_set_mode(struct xgbe_prv_data *pdata)
 333 {
 334         unsigned int reg;
 335
 336         reg = XI2C_IOREAD(pdata, IC_CON);
 337         XI2C_SET_BITS(reg, IC_CON, MASTER_MODE, 1);
 338         XI2C_SET_BITS(reg, IC_CON, SLAVE_DISABLE, 1);
 339         XI2C_SET_BITS(reg, IC_CON, RESTART_EN, 1);
 340         XI2C_SET_BITS(reg, IC_CON, SPEED, XGBE_STD_SPEED);
 341         XI2C_SET_BITS(reg, IC_CON, RX_FIFO_FULL_HOLD, 1);
 342         XI2C_IOWRITE(pdata, IC_CON, reg);
 343 }
 344
 345 static void xgbe_i2c_get_features(struct xgbe_prv_data *pdata)
 346 {
 347         struct xgbe_i2c *i2c = &pdata->i2c;
 348         unsigned int reg;
 349
 350         reg = XI2C_IOREAD(pdata, IC_COMP_PARAM_1);
 351         i2c->max_speed_mode = XI2C_GET_BITS(reg, IC_COMP_PARAM_1,
 352                                             MAX_SPEED_MODE);
 353         i2c->rx_fifo_size = XI2C_GET_BITS(reg, IC_COMP_PARAM_1,
 354                                           RX_BUFFER_DEPTH);
 355         i2c->tx_fifo_size = XI2C_GET_BITS(reg, IC_COMP_PARAM_1,
 356                                           TX_BUFFER_DEPTH);
 357
 358         if (netif_msg_probe(pdata))
 359                 dev_dbg(pdata->dev, "I2C features: %s=%u, %s=%u, %s=%u\n",
 360                         "MAX_SPEED_MODE", i2c->max_speed_mode,
 361                         "RX_BUFFER_DEPTH", i2c->rx_fifo_size,
 362                         "TX_BUFFER_DEPTH", i2c->tx_fifo_size);
 363 }
 364
 365 static void xgbe_i2c_set_target(struct xgbe_prv_data *pdata, unsigned int addr)
 366 {
 367         XI2C_IOWRITE(pdata, IC_TAR, addr);
 368 }
 369
 370 static irqreturn_t xgbe_i2c_combined_isr(struct xgbe_prv_data *pdata)
 371 {
 372         xgbe_i2c_isr_task((unsigned long)pdata);
 373
 374         return IRQ_HANDLED;
 375 }
 376
 377 static int xgbe_i2c_xfer(struct xgbe_prv_data *pdata, struct xgbe_i2c_op *op)
 378 {
 379         struct xgbe_i2c_op_state *state = &pdata->i2c.op_state;
 380         int ret;
 381
 382         mutex_lock(&pdata->i2c_mutex);
 383
 384         reinit_completion(&pdata->i2c_complete);
 385
 386         ret = xgbe_i2c_disable(pdata);
 387         if (ret) {
 388                 netdev_err(pdata->netdev, "failed to disable i2c master\n");
 389                 goto unlock;
 390         }
 391
 392         xgbe_i2c_set_target(pdata, op->target);
 393
 394         memset(state, 0, sizeof(*state));
 395         state->op = op;
 396         state->tx_len = op->len;
 397         state->tx_buf = op->buf;
 398         state->rx_len = op->len;
 399         state->rx_buf = op->buf;
 400
 401         xgbe_i2c_clear_all_interrupts(pdata);
 402         ret = xgbe_i2c_enable(pdata);
 403         if (ret) {
 404                 netdev_err(pdata->netdev, "failed to enable i2c master\n");
 405                 goto unlock;
 406         }
 407
 408         /* Enabling the interrupts will cause the TX FIFO empty interrupt to
 409          * fire and begin to process the command via the ISR.
 410          */
 411         xgbe_i2c_enable_interrupts(pdata);
 412
 413         if (!wait_for_completion_timeout(&pdata->i2c_complete, HZ)) {
 414                 netdev_err(pdata->netdev, "i2c operation timed out\n");
 415                 ret = -ETIMEDOUT;
 416                 goto disable;
 417         }
 418
 419         ret = state->ret;
 420         if (ret) {
 421                 if (state->tx_abort_source & IC_TX_ABRT_7B_ADDR_NOACK)
 422                         ret = -ENOTCONN;
 423                 else if (state->tx_abort_source & IC_TX_ABRT_ARB_LOST)
 424                         ret = -EAGAIN;
 425         }
 426
 427 disable:
 428         xgbe_i2c_disable_interrupts(pdata);
 429         xgbe_i2c_disable(pdata);
 430
 431 unlock:
 432         mutex_unlock(&pdata->i2c_mutex);
 433
 434         return ret;
 435 }
 436
 437 static void xgbe_i2c_stop(struct xgbe_prv_data *pdata)
 438 {
 439         if (!pdata->i2c.started)
 440                 return;
 441
 442         netif_dbg(pdata, link, pdata->netdev, "stopping I2C\n");
 443
 444         pdata->i2c.started = 0;
 445
 446         xgbe_i2c_disable_interrupts(pdata);
 447         xgbe_i2c_disable(pdata);
 448         xgbe_i2c_clear_all_interrupts(pdata);
 449
 450         if (pdata->dev_irq != pdata->i2c_irq)
 451                 devm_free_irq(pdata->dev, pdata->i2c_irq, pdata);
 452 }
 453
 454 static int xgbe_i2c_start(struct xgbe_prv_data *pdata)
 455 {
 456         int ret;
 457
 458         if (pdata->i2c.started)
 459                 return 0;
 460
 461         netif_dbg(pdata, link, pdata->netdev, "starting I2C\n");
 462
 463         /* If we have a separate I2C irq, enable it */
 464         if (pdata->dev_irq != pdata->i2c_irq) {
 465                 tasklet_init(&pdata->tasklet_i2c, xgbe_i2c_isr_task,
 466                              (unsigned long)pdata);
 467
 468                 ret = devm_request_irq(pdata->dev, pdata->i2c_irq,
 469                                        xgbe_i2c_isr, 0, pdata->i2c_name,
 470                                        pdata);
 471                 if (ret) {
 472                         netdev_err(pdata->netdev, "i2c irq request failed\n");
 473                         return ret;
 474                 }
 475         }
 476
 477         pdata->i2c.started = 1;
 478
 479         return 0;
 480 }
 481
 482 static int xgbe_i2c_init(struct xgbe_prv_data *pdata)
 483 {
 484         int ret;
 485
 486         xgbe_i2c_disable_interrupts(pdata);
 487
 488         ret = xgbe_i2c_disable(pdata);
 489         if (ret) {
 490                 dev_err(pdata->dev, "failed to disable i2c master\n");
 491                 return ret;
 492         }
 493
 494         xgbe_i2c_get_features(pdata);
 495
 496         xgbe_i2c_set_mode(pdata);
 497
 498         xgbe_i2c_clear_all_interrupts(pdata);
 499
 500         return 0;
 501 }
 502
 503 void xgbe_init_function_ptrs_i2c(struct xgbe_i2c_if *i2c_if)
 504 {
 505         i2c_if->i2c_init                = xgbe_i2c_init;
 506
 507         i2c_if->i2c_start               = xgbe_i2c_start;
 508         i2c_if->i2c_stop                = xgbe_i2c_stop;
 509
 510         i2c_if->i2c_xfer                = xgbe_i2c_xfer;
 511
 512         i2c_if->i2c_isr                 = xgbe_i2c_combined_isr;
 513 }