drivers/net/ethernet/mellanox/mlxsw/i2c.c

   1 /*
   2  * drivers/net/ethernet/mellanox/mlxsw/i2c.c
   3  * Copyright (c) 2016 Mellanox Technologies. All rights reserved.
   4  * Copyright (c) 2016 Vadim Pasternak <vadimp@mellanox.com>
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. Neither the names of the copyright holders nor the names of its
  15  *    contributors may be used to endorse or promote products derived from
  16  *    this software without specific prior written permission.
  17  *
  18  * Alternatively, this software may be distributed under the terms of the
  19  * GNU General Public License ("GPL") version 2 as published by the Free
  20  * Software Foundation.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  23  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  26  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  32  * POSSIBILITY OF SUCH DAMAGE.
  33  */
  34
  35 #include <linux/err.h>
  36 #include <linux/i2c.h>
  37 #include <linux/init.h>
  38 #include <linux/jiffies.h>
  39 #include <linux/kernel.h>
  40 #include <linux/mutex.h>
  41 #include <linux/module.h>
  42 #include <linux/mod_devicetable.h>
  43 #include <linux/slab.h>
  44
  45 #include "cmd.h"
  46 #include "core.h"
  47 #include "i2c.h"
  48
  49 static const char mlxsw_i2c_driver_name[] = "mlxsw_i2c";
  50
  51 #define MLXSW_I2C_CIR2_BASE             0x72000
  52 #define MLXSW_I2C_CIR_STATUS_OFF        0x18
  53 #define MLXSW_I2C_CIR2_OFF_STATUS       (MLXSW_I2C_CIR2_BASE + \
  54                                          MLXSW_I2C_CIR_STATUS_OFF)
  55 #define MLXSW_I2C_OPMOD_SHIFT           12
  56 #define MLXSW_I2C_GO_BIT_SHIFT          23
  57 #define MLXSW_I2C_CIR_CTRL_STATUS_SHIFT 24
  58 #define MLXSW_I2C_GO_BIT                BIT(MLXSW_I2C_GO_BIT_SHIFT)
  59 #define MLXSW_I2C_GO_OPMODE             BIT(MLXSW_I2C_OPMOD_SHIFT)
  60 #define MLXSW_I2C_SET_IMM_CMD           (MLXSW_I2C_GO_OPMODE | \
  61                                          MLXSW_CMD_OPCODE_QUERY_FW)
  62 #define MLXSW_I2C_PUSH_IMM_CMD          (MLXSW_I2C_GO_BIT | \
  63                                          MLXSW_I2C_SET_IMM_CMD)
  64 #define MLXSW_I2C_SET_CMD               (MLXSW_CMD_OPCODE_ACCESS_REG)
  65 #define MLXSW_I2C_PUSH_CMD              (MLXSW_I2C_GO_BIT | MLXSW_I2C_SET_CMD)
  66 #define MLXSW_I2C_TLV_HDR_SIZE          0x10
  67 #define MLXSW_I2C_ADDR_WIDTH            4
  68 #define MLXSW_I2C_PUSH_CMD_SIZE         (MLXSW_I2C_ADDR_WIDTH + 4)
  69 #define MLXSW_I2C_READ_SEMA_SIZE        4
  70 #define MLXSW_I2C_PREP_SIZE             (MLXSW_I2C_ADDR_WIDTH + 28)
  71 #define MLXSW_I2C_MBOX_SIZE             20
  72 #define MLXSW_I2C_MBOX_OUT_PARAM_OFF    12
  73 #define MLXSW_I2C_MAX_BUFF_SIZE         32
  74 #define MLXSW_I2C_MBOX_OFFSET_BITS      20
  75 #define MLXSW_I2C_MBOX_SIZE_BITS        12
  76 #define MLXSW_I2C_ADDR_BUF_SIZE         4
  77 #define MLXSW_I2C_BLK_MAX               32
  78 #define MLXSW_I2C_RETRY                 5
  79 #define MLXSW_I2C_TIMEOUT_MSECS         5000
  80
  81 /**
  82  * struct mlxsw_i2c - device private data:
  83  * @cmd.mb_size_in: input mailbox size;
  84  * @cmd.mb_off_in: input mailbox offset in register space;
  85  * @cmd.mb_size_out: output mailbox size;
  86  * @cmd.mb_off_out: output mailbox offset in register space;
  87  * @cmd.lock: command execution lock;
  88  * @dev: I2C device;
  89  * @core: switch core pointer;
  90  * @bus_info: bus info block;
  91  */
  92 struct mlxsw_i2c {
  93         struct {
  94                 u32 mb_size_in;
  95                 u32 mb_off_in;
  96                 u32 mb_size_out;
  97                 u32 mb_off_out;
  98                 struct mutex lock;
  99         } cmd;
 100         struct device *dev;
 101         struct mlxsw_core *core;
 102         struct mlxsw_bus_info bus_info;
 103 };
 104
 105 #define MLXSW_I2C_READ_MSG(_client, _addr_buf, _buf, _len) {    \
 106         { .addr = (_client)->addr,                              \
 107           .buf = (_addr_buf),                                   \
 108           .len = MLXSW_I2C_ADDR_BUF_SIZE,                       \
 109           .flags = 0 },                                         \
 110         { .addr = (_client)->addr,                              \
 111           .buf = (_buf),                                        \
 112           .len = (_len),                                        \
 113           .flags = I2C_M_RD } }
 114
 115 #define MLXSW_I2C_WRITE_MSG(_client, _buf, _len)                \
 116         { .addr = (_client)->addr,                              \
 117           .buf = (u8 *)(_buf),                                  \
 118           .len = (_len),                                        \
 119           .flags = 0 }
 120
 121 /* Routine converts in and out mail boxes offset and size. */
 122 static inline void
 123 mlxsw_i2c_convert_mbox(struct mlxsw_i2c *mlxsw_i2c, u8 *buf)
 124 {
 125         u32 tmp;
 126
 127         /* Local in/out mailboxes: 20 bits for offset, 12 for size */
 128         tmp = be32_to_cpup((__be32 *) buf);
 129         mlxsw_i2c->cmd.mb_off_in = tmp &
 130                                    GENMASK(MLXSW_I2C_MBOX_OFFSET_BITS - 1, 0);
 131         mlxsw_i2c->cmd.mb_size_in = (tmp & GENMASK(31,
 132                                         MLXSW_I2C_MBOX_OFFSET_BITS)) >>
 133                                         MLXSW_I2C_MBOX_OFFSET_BITS;
 134
 135         tmp = be32_to_cpup((__be32 *) (buf + MLXSW_I2C_ADDR_WIDTH));
 136         mlxsw_i2c->cmd.mb_off_out = tmp &
 137                                     GENMASK(MLXSW_I2C_MBOX_OFFSET_BITS - 1, 0);
 138         mlxsw_i2c->cmd.mb_size_out = (tmp & GENMASK(31,
 139                                         MLXSW_I2C_MBOX_OFFSET_BITS)) >>
 140                                         MLXSW_I2C_MBOX_OFFSET_BITS;
 141 }
 142
 143 /* Routine obtains register size from mail box buffer. */
 144 static inline int mlxsw_i2c_get_reg_size(u8 *in_mbox)
 145 {
 146         u16  tmp = be16_to_cpup((__be16 *) (in_mbox + MLXSW_I2C_TLV_HDR_SIZE));
 147
 148         return (tmp & 0x7ff) * 4 + MLXSW_I2C_TLV_HDR_SIZE;
 149 }
 150
 151 /* Routine sets I2C device internal offset in the transaction buffer. */
 152 static inline void mlxsw_i2c_set_slave_addr(u8 *buf, u32 off)
 153 {
 154         __be32 *val = (__be32 *) buf;
 155
 156         *val = htonl(off);
 157 }
 158
 159 /* Routine waits until go bit is cleared. */
 160 static int mlxsw_i2c_wait_go_bit(struct i2c_client *client,
 161                                  struct mlxsw_i2c *mlxsw_i2c, u8 *p_status)
 162 {
 163         u8 addr_buf[MLXSW_I2C_ADDR_BUF_SIZE];
 164         u8 buf[MLXSW_I2C_READ_SEMA_SIZE];
 165         int len = MLXSW_I2C_READ_SEMA_SIZE;
 166         struct i2c_msg read_sema[] =
 167                 MLXSW_I2C_READ_MSG(client, addr_buf, buf, len);
 168         bool wait_done = false;
 169         unsigned long end;
 170         int i = 0, err;
 171
 172         mlxsw_i2c_set_slave_addr(addr_buf, MLXSW_I2C_CIR2_OFF_STATUS);
 173
 174         end = jiffies + msecs_to_jiffies(MLXSW_I2C_TIMEOUT_MSECS);
 175         do {
 176                 u32 ctrl;
 177
 178                 err = i2c_transfer(client->adapter, read_sema,
 179                                    ARRAY_SIZE(read_sema));
 180
 181                 ctrl = be32_to_cpu(*(__be32 *) buf);
 182                 if (err == ARRAY_SIZE(read_sema)) {
 183                         if (!(ctrl & MLXSW_I2C_GO_BIT)) {
 184                                 wait_done = true;
 185                                 *p_status = ctrl >>
 186                                             MLXSW_I2C_CIR_CTRL_STATUS_SHIFT;
 187                                 break;
 188                         }
 189                 }
 190                 cond_resched();
 191         } while ((time_before(jiffies, end)) || (i++ < MLXSW_I2C_RETRY));
 192
 193         if (wait_done) {
 194                 if (*p_status)
 195                         err = -EIO;
 196         } else {
 197                 return -ETIMEDOUT;
 198         }
 199
 200         return err > 0 ? 0 : err;
 201 }
 202
 203 /* Routine posts a command to ASIC though mail box. */
 204 static int mlxsw_i2c_write_cmd(struct i2c_client *client,
 205                                struct mlxsw_i2c *mlxsw_i2c,
 206                                int immediate)
 207 {
 208         __be32 push_cmd_buf[MLXSW_I2C_PUSH_CMD_SIZE / 4] = {
 209                 0, cpu_to_be32(MLXSW_I2C_PUSH_IMM_CMD)
 210         };
 211         __be32 prep_cmd_buf[MLXSW_I2C_PREP_SIZE / 4] = {
 212                 0, 0, 0, 0, 0, 0,
 213                 cpu_to_be32(client->adapter->nr & 0xffff),
 214                 cpu_to_be32(MLXSW_I2C_SET_IMM_CMD)
 215         };
 216         struct i2c_msg push_cmd =
 217                 MLXSW_I2C_WRITE_MSG(client, push_cmd_buf,
 218                                     MLXSW_I2C_PUSH_CMD_SIZE);
 219         struct i2c_msg prep_cmd =
 220                 MLXSW_I2C_WRITE_MSG(client, prep_cmd_buf, MLXSW_I2C_PREP_SIZE);
 221         int err;
 222
 223         if (!immediate) {
 224                 push_cmd_buf[1] = cpu_to_be32(MLXSW_I2C_PUSH_CMD);
 225                 prep_cmd_buf[7] = cpu_to_be32(MLXSW_I2C_SET_CMD);
 226         }
 227         mlxsw_i2c_set_slave_addr((u8 *)prep_cmd_buf,
 228                                  MLXSW_I2C_CIR2_BASE);
 229         mlxsw_i2c_set_slave_addr((u8 *)push_cmd_buf,
 230                                  MLXSW_I2C_CIR2_OFF_STATUS);
 231
 232         /* Prepare Command Interface Register for transaction */
 233         err = i2c_transfer(client->adapter, &prep_cmd, 1);
 234         if (err < 0)
 235                 return err;
 236         else if (err != 1)
 237                 return -EIO;
 238
 239         /* Write out Command Interface Register GO bit to push transaction */
 240         err = i2c_transfer(client->adapter, &push_cmd, 1);
 241         if (err < 0)
 242                 return err;
 243         else if (err != 1)
 244                 return -EIO;
 245
 246         return 0;
 247 }
 248
 249 /* Routine obtains mail box offsets from ASIC register space. */
 250 static int mlxsw_i2c_get_mbox(struct i2c_client *client,
 251                               struct mlxsw_i2c *mlxsw_i2c)
 252 {
 253         u8 addr_buf[MLXSW_I2C_ADDR_BUF_SIZE];
 254         u8 buf[MLXSW_I2C_MBOX_SIZE];
 255         struct i2c_msg mbox_cmd[] =
 256                 MLXSW_I2C_READ_MSG(client, addr_buf, buf, MLXSW_I2C_MBOX_SIZE);
 257         int err;
 258
 259         /* Read mail boxes offsets. */
 260         mlxsw_i2c_set_slave_addr(addr_buf, MLXSW_I2C_CIR2_BASE);
 261         err = i2c_transfer(client->adapter, mbox_cmd, 2);
 262         if (err != 2) {
 263                 dev_err(&client->dev, "Could not obtain mail boxes\n");
 264                 if (!err)
 265                         return -EIO;
 266                 else
 267                         return err;
 268         }
 269
 270         /* Convert mail boxes. */
 271         mlxsw_i2c_convert_mbox(mlxsw_i2c, &buf[MLXSW_I2C_MBOX_OUT_PARAM_OFF]);
 272
 273         return err;
 274 }
 275
 276 /* Routine sends I2C write transaction to ASIC device. */
 277 static int
 278 mlxsw_i2c_write(struct device *dev, size_t in_mbox_size, u8 *in_mbox, int num,
 279                 u8 *p_status)
 280 {
 281         struct i2c_client *client = to_i2c_client(dev);
 282         struct mlxsw_i2c *mlxsw_i2c = i2c_get_clientdata(client);
 283         unsigned long timeout = msecs_to_jiffies(MLXSW_I2C_TIMEOUT_MSECS);
 284         u8 tran_buf[MLXSW_I2C_MAX_BUFF_SIZE + MLXSW_I2C_ADDR_BUF_SIZE];
 285         int off = mlxsw_i2c->cmd.mb_off_in, chunk_size, i, j;
 286         unsigned long end;
 287         struct i2c_msg write_tran =
 288                 MLXSW_I2C_WRITE_MSG(client, tran_buf, MLXSW_I2C_PUSH_CMD_SIZE);
 289         int err;
 290
 291         for (i = 0; i < num; i++) {
 292                 chunk_size = (in_mbox_size > MLXSW_I2C_BLK_MAX) ?
 293                              MLXSW_I2C_BLK_MAX : in_mbox_size;
 294                 write_tran.len = MLXSW_I2C_ADDR_WIDTH + chunk_size;
 295                 mlxsw_i2c_set_slave_addr(tran_buf, off);
 296                 memcpy(&tran_buf[MLXSW_I2C_ADDR_BUF_SIZE], in_mbox +
 297                        chunk_size * i, chunk_size);
 298
 299                 j = 0;
 300                 end = jiffies + timeout;
 301                 do {
 302                         err = i2c_transfer(client->adapter, &write_tran, 1);
 303                         if (err == 1)
 304                                 break;
 305
 306                         cond_resched();
 307                 } while ((time_before(jiffies, end)) ||
 308                          (j++ < MLXSW_I2C_RETRY));
 309
 310                 if (err != 1) {
 311                         if (!err)
 312                                 err = -EIO;
 313                         return err;
 314                 }
 315
 316                 off += chunk_size;
 317                 in_mbox_size -= chunk_size;
 318         }
 319
 320         /* Prepare and write out Command Interface Register for transaction. */
 321         err = mlxsw_i2c_write_cmd(client, mlxsw_i2c, 0);
 322         if (err) {
 323                 dev_err(&client->dev, "Could not start transaction");
 324                 return -EIO;
 325         }
 326
 327         /* Wait until go bit is cleared. */
 328         err = mlxsw_i2c_wait_go_bit(client, mlxsw_i2c, p_status);
 329         if (err) {
 330                 dev_err(&client->dev, "HW semaphore is not released");
 331                 return err;
 332         }
 333
 334         /* Validate transaction completion status. */
 335         if (*p_status) {
 336                 dev_err(&client->dev, "Bad transaction completion status %x\n",
 337                         *p_status);
 338                 return -EIO;
 339         }
 340
 341         return 0;
 342 }
 343
 344 /* Routine executes I2C command. */
 345 static int
 346 mlxsw_i2c_cmd(struct device *dev, size_t in_mbox_size, u8 *in_mbox,
 347               size_t out_mbox_size, u8 *out_mbox, u8 *status)
 348 {
 349         struct i2c_client *client = to_i2c_client(dev);
 350         struct mlxsw_i2c *mlxsw_i2c = i2c_get_clientdata(client);
 351         unsigned long timeout = msecs_to_jiffies(MLXSW_I2C_TIMEOUT_MSECS);
 352         u8 tran_buf[MLXSW_I2C_ADDR_BUF_SIZE];
 353         int num, chunk_size, reg_size, i, j;
 354         int off = mlxsw_i2c->cmd.mb_off_out;
 355         unsigned long end;
 356         struct i2c_msg read_tran[] =
 357                 MLXSW_I2C_READ_MSG(client, tran_buf, NULL, 0);
 358         int err;
 359
 360         WARN_ON(in_mbox_size % sizeof(u32) || out_mbox_size % sizeof(u32));
 361
 362         reg_size = mlxsw_i2c_get_reg_size(in_mbox);
 363         num = reg_size / MLXSW_I2C_BLK_MAX;
 364         if (reg_size % MLXSW_I2C_BLK_MAX)
 365                 num++;
 366
 367         if (mutex_lock_interruptible(&mlxsw_i2c->cmd.lock) < 0) {
 368                 dev_err(&client->dev, "Could not acquire lock");
 369                 return -EINVAL;
 370         }
 371
 372         err = mlxsw_i2c_write(dev, reg_size, in_mbox, num, status);
 373         if (err)
 374                 goto cmd_fail;
 375
 376         /* No out mailbox is case of write transaction. */
 377         if (!out_mbox) {
 378                 mutex_unlock(&mlxsw_i2c->cmd.lock);
 379                 return 0;
 380         }
 381
 382         /* Send read transaction to get output mailbox content. */
 383         read_tran[1].buf = out_mbox;
 384         for (i = 0; i < num; i++) {
 385                 chunk_size = (reg_size > MLXSW_I2C_BLK_MAX) ?
 386                              MLXSW_I2C_BLK_MAX : reg_size;
 387                 read_tran[1].len = chunk_size;
 388                 mlxsw_i2c_set_slave_addr(tran_buf, off);
 389
 390                 j = 0;
 391                 end = jiffies + timeout;
 392                 do {
 393                         err = i2c_transfer(client->adapter, read_tran,
 394                                            ARRAY_SIZE(read_tran));
 395                         if (err == ARRAY_SIZE(read_tran))
 396                                 break;
 397
 398                         cond_resched();
 399                 } while ((time_before(jiffies, end)) ||
 400                          (j++ < MLXSW_I2C_RETRY));
 401
 402                 if (err != ARRAY_SIZE(read_tran)) {
 403                         if (!err)
 404                                 err = -EIO;
 405
 406                         goto cmd_fail;
 407                 }
 408
 409                 off += chunk_size;
 410                 reg_size -= chunk_size;
 411                 read_tran[1].buf += chunk_size;
 412         }
 413
 414         mutex_unlock(&mlxsw_i2c->cmd.lock);
 415
 416         return 0;
 417
 418 cmd_fail:
 419         mutex_unlock(&mlxsw_i2c->cmd.lock);
 420         return err;
 421 }
 422
 423 static int mlxsw_i2c_cmd_exec(void *bus_priv, u16 opcode, u8 opcode_mod,
 424                               u32 in_mod, bool out_mbox_direct,
 425                               char *in_mbox, size_t in_mbox_size,
 426                               char *out_mbox, size_t out_mbox_size,
 427                               u8 *status)
 428 {
 429         struct mlxsw_i2c *mlxsw_i2c = bus_priv;
 430
 431         return mlxsw_i2c_cmd(mlxsw_i2c->dev, in_mbox_size, in_mbox,
 432                              out_mbox_size, out_mbox, status);
 433 }
 434
 435 static bool mlxsw_i2c_skb_transmit_busy(void *bus_priv,
 436                                         const struct mlxsw_tx_info *tx_info)
 437 {
 438         return false;
 439 }
 440
 441 static int mlxsw_i2c_skb_transmit(void *bus_priv, struct sk_buff *skb,
 442                                   const struct mlxsw_tx_info *tx_info)
 443 {
 444         return 0;
 445 }
 446
 447 static int
 448 mlxsw_i2c_init(void *bus_priv, struct mlxsw_core *mlxsw_core,
 449                const struct mlxsw_config_profile *profile,
 450                struct mlxsw_res *resources)
 451 {
 452         struct mlxsw_i2c *mlxsw_i2c = bus_priv;
 453
 454         mlxsw_i2c->core = mlxsw_core;
 455
 456         return 0;
 457 }
 458
 459 static void mlxsw_i2c_fini(void *bus_priv)
 460 {
 461         struct mlxsw_i2c *mlxsw_i2c = bus_priv;
 462
 463         mlxsw_i2c->core = NULL;
 464 }
 465
 466 static const struct mlxsw_bus mlxsw_i2c_bus = {
 467         .kind                   = "i2c",
 468         .init                   = mlxsw_i2c_init,
 469         .fini                   = mlxsw_i2c_fini,
 470         .skb_transmit_busy      = mlxsw_i2c_skb_transmit_busy,
 471         .skb_transmit           = mlxsw_i2c_skb_transmit,
 472         .cmd_exec               = mlxsw_i2c_cmd_exec,
 473 };
 474
 475 static int mlxsw_i2c_probe(struct i2c_client *client,
 476                            const struct i2c_device_id *id)
 477 {
 478         struct mlxsw_i2c *mlxsw_i2c;
 479         u8 status;
 480         int err;
 481
 482         mlxsw_i2c = devm_kzalloc(&client->dev, sizeof(*mlxsw_i2c), GFP_KERNEL);
 483         if (!mlxsw_i2c)
 484                 return -ENOMEM;
 485
 486         i2c_set_clientdata(client, mlxsw_i2c);
 487         mutex_init(&mlxsw_i2c->cmd.lock);
 488
 489         /* In order to use mailboxes through the i2c, special area is reserved
 490          * on the i2c address space that can be used for input and output
 491          * mailboxes. Such mailboxes are called local mailboxes. When using a
 492          * local mailbox, software should specify 0 as the Input/Output
 493          * parameters. The location of the Local Mailbox addresses on the i2c
 494          * space can be retrieved through the QUERY_FW command.
 495          * For this purpose QUERY_FW is to be issued with opcode modifier equal
 496          * 0x01. For such command the output parameter is an immediate value.
 497          * Here QUERY_FW command is invoked for ASIC probing and for getting
 498          * local mailboxes addresses from immedate output parameters.
 499          */
 500
 501         /* Prepare and write out Command Interface Register for transaction */
 502         err = mlxsw_i2c_write_cmd(client, mlxsw_i2c, 1);
 503         if (err) {
 504                 dev_err(&client->dev, "Could not start transaction");
 505                 goto errout;
 506         }
 507
 508         /* Wait until go bit is cleared. */
 509         err = mlxsw_i2c_wait_go_bit(client, mlxsw_i2c, &status);
 510         if (err) {
 511                 dev_err(&client->dev, "HW semaphore is not released");
 512                 goto errout;
 513         }
 514
 515         /* Validate transaction completion status. */
 516         if (status) {
 517                 dev_err(&client->dev, "Bad transaction completion status %x\n",
 518                         status);
 519                 err = -EIO;
 520                 goto errout;
 521         }
 522
 523         /* Get mailbox offsets. */
 524         err = mlxsw_i2c_get_mbox(client, mlxsw_i2c);
 525         if (err < 0) {
 526                 dev_err(&client->dev, "Fail to get mailboxes\n");
 527                 goto errout;
 528         }
 529
 530         dev_info(&client->dev, "%s mb size=%x off=0x%08x out mb size=%x off=0x%08x\n",
 531                  id->name, mlxsw_i2c->cmd.mb_size_in,
 532                  mlxsw_i2c->cmd.mb_off_in, mlxsw_i2c->cmd.mb_size_out,
 533                  mlxsw_i2c->cmd.mb_off_out);
 534
 535         /* Register device bus. */
 536         mlxsw_i2c->bus_info.device_kind = id->name;
 537         mlxsw_i2c->bus_info.device_name = client->name;
 538         mlxsw_i2c->bus_info.dev = &client->dev;
 539         mlxsw_i2c->dev = &client->dev;
 540
 541         err = mlxsw_core_bus_device_register(&mlxsw_i2c->bus_info,
 542                                              &mlxsw_i2c_bus, mlxsw_i2c);
 543         if (err) {
 544                 dev_err(&client->dev, "Fail to register core bus\n");
 545                 return err;
 546         }
 547
 548         return 0;
 549
 550 errout:
 551         i2c_set_clientdata(client, NULL);
 552
 553         return err;
 554 }
 555
 556 static int mlxsw_i2c_remove(struct i2c_client *client)
 557 {
 558         struct mlxsw_i2c *mlxsw_i2c = i2c_get_clientdata(client);
 559
 560         mlxsw_core_bus_device_unregister(mlxsw_i2c->core);
 561         mutex_destroy(&mlxsw_i2c->cmd.lock);
 562
 563         return 0;
 564 }
 565
 566 int mlxsw_i2c_driver_register(struct i2c_driver *i2c_driver)
 567 {
 568         i2c_driver->probe = mlxsw_i2c_probe;
 569         i2c_driver->remove = mlxsw_i2c_remove;
 570         return i2c_add_driver(i2c_driver);
 571 }
 572 EXPORT_SYMBOL(mlxsw_i2c_driver_register);
 573
 574 void mlxsw_i2c_driver_unregister(struct i2c_driver *i2c_driver)
 575 {
 576         i2c_del_driver(i2c_driver);
 577 }
 578 EXPORT_SYMBOL(mlxsw_i2c_driver_unregister);
 579
 580 MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
 581 MODULE_DESCRIPTION("Mellanox switch I2C interface driver");
 582 MODULE_LICENSE("Dual BSD/GPL");