1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 2 /* Copyright (c) 2016-2018 Mellanox Technologies. All rights reserved */ 3 4 #include <linux/err.h> 5 #include <linux/i2c.h> 6 #include <linux/init.h> 7 #include <linux/jiffies.h> 8 #include <linux/kernel.h> 9 #include <linux/mutex.h> 10 #include <linux/module.h> 11 #include <linux/mod_devicetable.h> 12 #include <linux/slab.h> 13 14 #include "cmd.h" 15 #include "core.h" 16 #include "i2c.h" 17 #include "resources.h" 18 19 #define MLXSW_I2C_CIR2_BASE 0x72000 20 #define MLXSW_I2C_CIR_STATUS_OFF 0x18 21 #define MLXSW_I2C_CIR2_OFF_STATUS (MLXSW_I2C_CIR2_BASE + \ 22 MLXSW_I2C_CIR_STATUS_OFF) 23 #define MLXSW_I2C_OPMOD_SHIFT 12 24 #define MLXSW_I2C_EVENT_BIT_SHIFT 22 25 #define MLXSW_I2C_GO_BIT_SHIFT 23 26 #define MLXSW_I2C_CIR_CTRL_STATUS_SHIFT 24 27 #define MLXSW_I2C_EVENT_BIT BIT(MLXSW_I2C_EVENT_BIT_SHIFT) 28 #define MLXSW_I2C_GO_BIT BIT(MLXSW_I2C_GO_BIT_SHIFT) 29 #define MLXSW_I2C_GO_OPMODE BIT(MLXSW_I2C_OPMOD_SHIFT) 30 #define MLXSW_I2C_SET_IMM_CMD (MLXSW_I2C_GO_OPMODE | \ 31 MLXSW_CMD_OPCODE_QUERY_FW) 32 #define MLXSW_I2C_PUSH_IMM_CMD (MLXSW_I2C_GO_BIT | \ 33 MLXSW_I2C_SET_IMM_CMD) 34 #define MLXSW_I2C_SET_CMD (MLXSW_CMD_OPCODE_ACCESS_REG) 35 #define MLXSW_I2C_PUSH_CMD (MLXSW_I2C_GO_BIT | MLXSW_I2C_SET_CMD) 36 #define MLXSW_I2C_TLV_HDR_SIZE 0x10 37 #define MLXSW_I2C_ADDR_WIDTH 4 38 #define MLXSW_I2C_PUSH_CMD_SIZE (MLXSW_I2C_ADDR_WIDTH + 4) 39 #define MLXSW_I2C_SET_EVENT_CMD (MLXSW_I2C_EVENT_BIT) 40 #define MLXSW_I2C_PUSH_EVENT_CMD (MLXSW_I2C_GO_BIT | \ 41 MLXSW_I2C_SET_EVENT_CMD) 42 #define MLXSW_I2C_READ_SEMA_SIZE 4 43 #define MLXSW_I2C_PREP_SIZE (MLXSW_I2C_ADDR_WIDTH + 28) 44 #define MLXSW_I2C_MBOX_SIZE 20 45 #define MLXSW_I2C_MBOX_OUT_PARAM_OFF 12 46 #define MLXSW_I2C_MBOX_OFFSET_BITS 20 47 #define MLXSW_I2C_MBOX_SIZE_BITS 12 48 #define MLXSW_I2C_ADDR_BUF_SIZE 4 49 #define MLXSW_I2C_BLK_DEF 32 50 #define MLXSW_I2C_RETRY 5 51 #define MLXSW_I2C_TIMEOUT_MSECS 5000 52 #define MLXSW_I2C_MAX_DATA_SIZE 256 53 54 /** 55 * struct mlxsw_i2c - device private data: 56 * @cmd.mb_size_in: input mailbox size; 57 * @cmd.mb_off_in: input mailbox offset in register space; 58 * @cmd.mb_size_out: output mailbox size; 59 * @cmd.mb_off_out: output mailbox offset in register space; 60 * @cmd.lock: command execution lock; 61 * @dev: I2C device; 62 * @core: switch core pointer; 63 * @bus_info: bus info block; 64 * @block_size: maximum block size allowed to pass to under layer; 65 */ 66 struct mlxsw_i2c { 67 struct { 68 u32 mb_size_in; 69 u32 mb_off_in; 70 u32 mb_size_out; 71 u32 mb_off_out; 72 struct mutex lock; 73 } cmd; 74 struct device *dev; 75 struct mlxsw_core *core; 76 struct mlxsw_bus_info bus_info; 77 u16 block_size; 78 }; 79 80 #define MLXSW_I2C_READ_MSG(_client, _addr_buf, _buf, _len) { \ 81 { .addr = (_client)->addr, \ 82 .buf = (_addr_buf), \ 83 .len = MLXSW_I2C_ADDR_BUF_SIZE, \ 84 .flags = 0 }, \ 85 { .addr = (_client)->addr, \ 86 .buf = (_buf), \ 87 .len = (_len), \ 88 .flags = I2C_M_RD } } 89 90 #define MLXSW_I2C_WRITE_MSG(_client, _buf, _len) \ 91 { .addr = (_client)->addr, \ 92 .buf = (u8 *)(_buf), \ 93 .len = (_len), \ 94 .flags = 0 } 95 96 /* Routine converts in and out mail boxes offset and size. */ 97 static inline void 98 mlxsw_i2c_convert_mbox(struct mlxsw_i2c *mlxsw_i2c, u8 *buf) 99 { 100 u32 tmp; 101 102 /* Local in/out mailboxes: 20 bits for offset, 12 for size */ 103 tmp = be32_to_cpup((__be32 *) buf); 104 mlxsw_i2c->cmd.mb_off_in = tmp & 105 GENMASK(MLXSW_I2C_MBOX_OFFSET_BITS - 1, 0); 106 mlxsw_i2c->cmd.mb_size_in = (tmp & GENMASK(31, 107 MLXSW_I2C_MBOX_OFFSET_BITS)) >> 108 MLXSW_I2C_MBOX_OFFSET_BITS; 109 110 tmp = be32_to_cpup((__be32 *) (buf + MLXSW_I2C_ADDR_WIDTH)); 111 mlxsw_i2c->cmd.mb_off_out = tmp & 112 GENMASK(MLXSW_I2C_MBOX_OFFSET_BITS - 1, 0); 113 mlxsw_i2c->cmd.mb_size_out = (tmp & GENMASK(31, 114 MLXSW_I2C_MBOX_OFFSET_BITS)) >> 115 MLXSW_I2C_MBOX_OFFSET_BITS; 116 } 117 118 /* Routine obtains register size from mail box buffer. */ 119 static inline int mlxsw_i2c_get_reg_size(u8 *in_mbox) 120 { 121 u16 tmp = be16_to_cpup((__be16 *) (in_mbox + MLXSW_I2C_TLV_HDR_SIZE)); 122 123 return (tmp & 0x7ff) * 4 + MLXSW_I2C_TLV_HDR_SIZE; 124 } 125 126 /* Routine sets I2C device internal offset in the transaction buffer. */ 127 static inline void mlxsw_i2c_set_slave_addr(u8 *buf, u32 off) 128 { 129 __be32 *val = (__be32 *) buf; 130 131 *val = htonl(off); 132 } 133 134 /* Routine waits until go bit is cleared. */ 135 static int mlxsw_i2c_wait_go_bit(struct i2c_client *client, 136 struct mlxsw_i2c *mlxsw_i2c, u8 *p_status) 137 { 138 u8 addr_buf[MLXSW_I2C_ADDR_BUF_SIZE]; 139 u8 buf[MLXSW_I2C_READ_SEMA_SIZE]; 140 int len = MLXSW_I2C_READ_SEMA_SIZE; 141 struct i2c_msg read_sema[] = 142 MLXSW_I2C_READ_MSG(client, addr_buf, buf, len); 143 bool wait_done = false; 144 unsigned long end; 145 int i = 0, err; 146 147 mlxsw_i2c_set_slave_addr(addr_buf, MLXSW_I2C_CIR2_OFF_STATUS); 148 149 end = jiffies + msecs_to_jiffies(MLXSW_I2C_TIMEOUT_MSECS); 150 do { 151 u32 ctrl; 152 153 err = i2c_transfer(client->adapter, read_sema, 154 ARRAY_SIZE(read_sema)); 155 156 ctrl = be32_to_cpu(*(__be32 *) buf); 157 if (err == ARRAY_SIZE(read_sema)) { 158 if (!(ctrl & MLXSW_I2C_GO_BIT)) { 159 wait_done = true; 160 *p_status = ctrl >> 161 MLXSW_I2C_CIR_CTRL_STATUS_SHIFT; 162 break; 163 } 164 } 165 cond_resched(); 166 } while ((time_before(jiffies, end)) || (i++ < MLXSW_I2C_RETRY)); 167 168 if (wait_done) { 169 if (*p_status) 170 err = -EIO; 171 } else { 172 return -ETIMEDOUT; 173 } 174 175 return err > 0 ? 0 : err; 176 } 177 178 /* Routine posts a command to ASIC through mail box. */ 179 static int mlxsw_i2c_write_cmd(struct i2c_client *client, 180 struct mlxsw_i2c *mlxsw_i2c, 181 int immediate) 182 { 183 __be32 push_cmd_buf[MLXSW_I2C_PUSH_CMD_SIZE / 4] = { 184 0, cpu_to_be32(MLXSW_I2C_PUSH_IMM_CMD) 185 }; 186 __be32 prep_cmd_buf[MLXSW_I2C_PREP_SIZE / 4] = { 187 0, 0, 0, 0, 0, 0, 188 cpu_to_be32(client->adapter->nr & 0xffff), 189 cpu_to_be32(MLXSW_I2C_SET_IMM_CMD) 190 }; 191 struct i2c_msg push_cmd = 192 MLXSW_I2C_WRITE_MSG(client, push_cmd_buf, 193 MLXSW_I2C_PUSH_CMD_SIZE); 194 struct i2c_msg prep_cmd = 195 MLXSW_I2C_WRITE_MSG(client, prep_cmd_buf, MLXSW_I2C_PREP_SIZE); 196 int err; 197 198 if (!immediate) { 199 push_cmd_buf[1] = cpu_to_be32(MLXSW_I2C_PUSH_CMD); 200 prep_cmd_buf[7] = cpu_to_be32(MLXSW_I2C_SET_CMD); 201 } 202 mlxsw_i2c_set_slave_addr((u8 *)prep_cmd_buf, 203 MLXSW_I2C_CIR2_BASE); 204 mlxsw_i2c_set_slave_addr((u8 *)push_cmd_buf, 205 MLXSW_I2C_CIR2_OFF_STATUS); 206 207 /* Prepare Command Interface Register for transaction */ 208 err = i2c_transfer(client->adapter, &prep_cmd, 1); 209 if (err < 0) 210 return err; 211 else if (err != 1) 212 return -EIO; 213 214 /* Write out Command Interface Register GO bit to push transaction */ 215 err = i2c_transfer(client->adapter, &push_cmd, 1); 216 if (err < 0) 217 return err; 218 else if (err != 1) 219 return -EIO; 220 221 return 0; 222 } 223 224 /* Routine posts initialization command to ASIC through mail box. */ 225 static int 226 mlxsw_i2c_write_init_cmd(struct i2c_client *client, 227 struct mlxsw_i2c *mlxsw_i2c, u16 opcode, u32 in_mod) 228 { 229 __be32 push_cmd_buf[MLXSW_I2C_PUSH_CMD_SIZE / 4] = { 230 0, cpu_to_be32(MLXSW_I2C_PUSH_EVENT_CMD) 231 }; 232 __be32 prep_cmd_buf[MLXSW_I2C_PREP_SIZE / 4] = { 233 0, 0, 0, 0, 0, 0, 234 cpu_to_be32(client->adapter->nr & 0xffff), 235 cpu_to_be32(MLXSW_I2C_SET_EVENT_CMD) 236 }; 237 struct i2c_msg push_cmd = 238 MLXSW_I2C_WRITE_MSG(client, push_cmd_buf, 239 MLXSW_I2C_PUSH_CMD_SIZE); 240 struct i2c_msg prep_cmd = 241 MLXSW_I2C_WRITE_MSG(client, prep_cmd_buf, MLXSW_I2C_PREP_SIZE); 242 u8 status; 243 int err; 244 245 push_cmd_buf[1] = cpu_to_be32(MLXSW_I2C_PUSH_EVENT_CMD | opcode); 246 prep_cmd_buf[3] = cpu_to_be32(in_mod); 247 prep_cmd_buf[7] = cpu_to_be32(MLXSW_I2C_GO_BIT | opcode); 248 mlxsw_i2c_set_slave_addr((u8 *)prep_cmd_buf, 249 MLXSW_I2C_CIR2_BASE); 250 mlxsw_i2c_set_slave_addr((u8 *)push_cmd_buf, 251 MLXSW_I2C_CIR2_OFF_STATUS); 252 253 /* Prepare Command Interface Register for transaction */ 254 err = i2c_transfer(client->adapter, &prep_cmd, 1); 255 if (err < 0) 256 return err; 257 else if (err != 1) 258 return -EIO; 259 260 /* Write out Command Interface Register GO bit to push transaction */ 261 err = i2c_transfer(client->adapter, &push_cmd, 1); 262 if (err < 0) 263 return err; 264 else if (err != 1) 265 return -EIO; 266 267 /* Wait until go bit is cleared. */ 268 err = mlxsw_i2c_wait_go_bit(client, mlxsw_i2c, &status); 269 if (err) { 270 dev_err(&client->dev, "HW semaphore is not released"); 271 return err; 272 } 273 274 /* Validate transaction completion status. */ 275 if (status) { 276 dev_err(&client->dev, "Bad transaction completion status %x\n", 277 status); 278 return -EIO; 279 } 280 281 return 0; 282 } 283 284 /* Routine obtains mail box offsets from ASIC register space. */ 285 static int mlxsw_i2c_get_mbox(struct i2c_client *client, 286 struct mlxsw_i2c *mlxsw_i2c) 287 { 288 u8 addr_buf[MLXSW_I2C_ADDR_BUF_SIZE]; 289 u8 buf[MLXSW_I2C_MBOX_SIZE]; 290 struct i2c_msg mbox_cmd[] = 291 MLXSW_I2C_READ_MSG(client, addr_buf, buf, MLXSW_I2C_MBOX_SIZE); 292 int err; 293 294 /* Read mail boxes offsets. */ 295 mlxsw_i2c_set_slave_addr(addr_buf, MLXSW_I2C_CIR2_BASE); 296 err = i2c_transfer(client->adapter, mbox_cmd, 2); 297 if (err != 2) { 298 dev_err(&client->dev, "Could not obtain mail boxes\n"); 299 if (!err) 300 return -EIO; 301 else 302 return err; 303 } 304 305 /* Convert mail boxes. */ 306 mlxsw_i2c_convert_mbox(mlxsw_i2c, &buf[MLXSW_I2C_MBOX_OUT_PARAM_OFF]); 307 308 return err; 309 } 310 311 /* Routine sends I2C write transaction to ASIC device. */ 312 static int 313 mlxsw_i2c_write(struct device *dev, size_t in_mbox_size, u8 *in_mbox, int num, 314 u8 *p_status) 315 { 316 struct i2c_client *client = to_i2c_client(dev); 317 struct mlxsw_i2c *mlxsw_i2c = i2c_get_clientdata(client); 318 unsigned long timeout = msecs_to_jiffies(MLXSW_I2C_TIMEOUT_MSECS); 319 int off = mlxsw_i2c->cmd.mb_off_in, chunk_size, i, j; 320 unsigned long end; 321 u8 *tran_buf; 322 struct i2c_msg write_tran = 323 MLXSW_I2C_WRITE_MSG(client, NULL, MLXSW_I2C_PUSH_CMD_SIZE); 324 int err; 325 326 tran_buf = kmalloc(mlxsw_i2c->block_size + MLXSW_I2C_ADDR_BUF_SIZE, 327 GFP_KERNEL); 328 if (!tran_buf) 329 return -ENOMEM; 330 331 write_tran.buf = tran_buf; 332 for (i = 0; i < num; i++) { 333 chunk_size = (in_mbox_size > mlxsw_i2c->block_size) ? 334 mlxsw_i2c->block_size : in_mbox_size; 335 write_tran.len = MLXSW_I2C_ADDR_WIDTH + chunk_size; 336 mlxsw_i2c_set_slave_addr(tran_buf, off); 337 memcpy(&tran_buf[MLXSW_I2C_ADDR_BUF_SIZE], in_mbox + 338 mlxsw_i2c->block_size * i, chunk_size); 339 340 j = 0; 341 end = jiffies + timeout; 342 do { 343 err = i2c_transfer(client->adapter, &write_tran, 1); 344 if (err == 1) 345 break; 346 347 cond_resched(); 348 } while ((time_before(jiffies, end)) || 349 (j++ < MLXSW_I2C_RETRY)); 350 351 if (err != 1) { 352 if (!err) { 353 err = -EIO; 354 goto mlxsw_i2c_write_exit; 355 } 356 } 357 358 off += chunk_size; 359 in_mbox_size -= chunk_size; 360 } 361 362 /* Prepare and write out Command Interface Register for transaction. */ 363 err = mlxsw_i2c_write_cmd(client, mlxsw_i2c, 0); 364 if (err) { 365 dev_err(&client->dev, "Could not start transaction"); 366 err = -EIO; 367 goto mlxsw_i2c_write_exit; 368 } 369 370 /* Wait until go bit is cleared. */ 371 err = mlxsw_i2c_wait_go_bit(client, mlxsw_i2c, p_status); 372 if (err) { 373 dev_err(&client->dev, "HW semaphore is not released"); 374 goto mlxsw_i2c_write_exit; 375 } 376 377 /* Validate transaction completion status. */ 378 if (*p_status) { 379 dev_err(&client->dev, "Bad transaction completion status %x\n", 380 *p_status); 381 err = -EIO; 382 } 383 384 mlxsw_i2c_write_exit: 385 kfree(tran_buf); 386 return err; 387 } 388 389 /* Routine executes I2C command. */ 390 static int 391 mlxsw_i2c_cmd(struct device *dev, u16 opcode, u32 in_mod, size_t in_mbox_size, 392 u8 *in_mbox, size_t out_mbox_size, u8 *out_mbox, u8 *status) 393 { 394 struct i2c_client *client = to_i2c_client(dev); 395 struct mlxsw_i2c *mlxsw_i2c = i2c_get_clientdata(client); 396 unsigned long timeout = msecs_to_jiffies(MLXSW_I2C_TIMEOUT_MSECS); 397 u8 tran_buf[MLXSW_I2C_ADDR_BUF_SIZE]; 398 int num, chunk_size, reg_size, i, j; 399 int off = mlxsw_i2c->cmd.mb_off_out; 400 unsigned long end; 401 struct i2c_msg read_tran[] = 402 MLXSW_I2C_READ_MSG(client, tran_buf, NULL, 0); 403 int err; 404 405 WARN_ON(in_mbox_size % sizeof(u32) || out_mbox_size % sizeof(u32)); 406 407 if (in_mbox) { 408 reg_size = mlxsw_i2c_get_reg_size(in_mbox); 409 num = reg_size / mlxsw_i2c->block_size; 410 if (reg_size % mlxsw_i2c->block_size) 411 num++; 412 413 if (mutex_lock_interruptible(&mlxsw_i2c->cmd.lock) < 0) { 414 dev_err(&client->dev, "Could not acquire lock"); 415 return -EINVAL; 416 } 417 418 err = mlxsw_i2c_write(dev, reg_size, in_mbox, num, status); 419 if (err) 420 goto cmd_fail; 421 422 /* No out mailbox is case of write transaction. */ 423 if (!out_mbox) { 424 mutex_unlock(&mlxsw_i2c->cmd.lock); 425 return 0; 426 } 427 } else { 428 /* No input mailbox is case of initialization query command. */ 429 reg_size = MLXSW_I2C_MAX_DATA_SIZE; 430 num = reg_size / mlxsw_i2c->block_size; 431 432 if (mutex_lock_interruptible(&mlxsw_i2c->cmd.lock) < 0) { 433 dev_err(&client->dev, "Could not acquire lock"); 434 return -EINVAL; 435 } 436 437 err = mlxsw_i2c_write_init_cmd(client, mlxsw_i2c, opcode, 438 in_mod); 439 if (err) 440 goto cmd_fail; 441 } 442 443 /* Send read transaction to get output mailbox content. */ 444 read_tran[1].buf = out_mbox; 445 for (i = 0; i < num; i++) { 446 chunk_size = (reg_size > mlxsw_i2c->block_size) ? 447 mlxsw_i2c->block_size : reg_size; 448 read_tran[1].len = chunk_size; 449 mlxsw_i2c_set_slave_addr(tran_buf, off); 450 451 j = 0; 452 end = jiffies + timeout; 453 do { 454 err = i2c_transfer(client->adapter, read_tran, 455 ARRAY_SIZE(read_tran)); 456 if (err == ARRAY_SIZE(read_tran)) 457 break; 458 459 cond_resched(); 460 } while ((time_before(jiffies, end)) || 461 (j++ < MLXSW_I2C_RETRY)); 462 463 if (err != ARRAY_SIZE(read_tran)) { 464 if (!err) 465 err = -EIO; 466 467 goto cmd_fail; 468 } 469 470 off += chunk_size; 471 reg_size -= chunk_size; 472 read_tran[1].buf += chunk_size; 473 } 474 475 mutex_unlock(&mlxsw_i2c->cmd.lock); 476 477 return 0; 478 479 cmd_fail: 480 mutex_unlock(&mlxsw_i2c->cmd.lock); 481 return err; 482 } 483 484 static int mlxsw_i2c_cmd_exec(void *bus_priv, u16 opcode, u8 opcode_mod, 485 u32 in_mod, bool out_mbox_direct, 486 char *in_mbox, size_t in_mbox_size, 487 char *out_mbox, size_t out_mbox_size, 488 u8 *status) 489 { 490 struct mlxsw_i2c *mlxsw_i2c = bus_priv; 491 492 return mlxsw_i2c_cmd(mlxsw_i2c->dev, opcode, in_mod, in_mbox_size, 493 in_mbox, out_mbox_size, out_mbox, status); 494 } 495 496 static bool mlxsw_i2c_skb_transmit_busy(void *bus_priv, 497 const struct mlxsw_tx_info *tx_info) 498 { 499 return false; 500 } 501 502 static int mlxsw_i2c_skb_transmit(void *bus_priv, struct sk_buff *skb, 503 const struct mlxsw_tx_info *tx_info) 504 { 505 return 0; 506 } 507 508 static int 509 mlxsw_i2c_init(void *bus_priv, struct mlxsw_core *mlxsw_core, 510 const struct mlxsw_config_profile *profile, 511 struct mlxsw_res *res) 512 { 513 struct mlxsw_i2c *mlxsw_i2c = bus_priv; 514 char *mbox; 515 int err; 516 517 mlxsw_i2c->core = mlxsw_core; 518 519 mbox = mlxsw_cmd_mbox_alloc(); 520 if (!mbox) 521 return -ENOMEM; 522 523 err = mlxsw_cmd_query_fw(mlxsw_core, mbox); 524 if (err) 525 goto mbox_put; 526 527 mlxsw_i2c->bus_info.fw_rev.major = 528 mlxsw_cmd_mbox_query_fw_fw_rev_major_get(mbox); 529 mlxsw_i2c->bus_info.fw_rev.minor = 530 mlxsw_cmd_mbox_query_fw_fw_rev_minor_get(mbox); 531 mlxsw_i2c->bus_info.fw_rev.subminor = 532 mlxsw_cmd_mbox_query_fw_fw_rev_subminor_get(mbox); 533 534 err = mlxsw_core_resources_query(mlxsw_core, mbox, res); 535 536 mbox_put: 537 mlxsw_cmd_mbox_free(mbox); 538 return err; 539 } 540 541 static void mlxsw_i2c_fini(void *bus_priv) 542 { 543 struct mlxsw_i2c *mlxsw_i2c = bus_priv; 544 545 mlxsw_i2c->core = NULL; 546 } 547 548 static const struct mlxsw_bus mlxsw_i2c_bus = { 549 .kind = "i2c", 550 .init = mlxsw_i2c_init, 551 .fini = mlxsw_i2c_fini, 552 .skb_transmit_busy = mlxsw_i2c_skb_transmit_busy, 553 .skb_transmit = mlxsw_i2c_skb_transmit, 554 .cmd_exec = mlxsw_i2c_cmd_exec, 555 }; 556 557 static int mlxsw_i2c_probe(struct i2c_client *client, 558 const struct i2c_device_id *id) 559 { 560 const struct i2c_adapter_quirks *quirks = client->adapter->quirks; 561 struct mlxsw_i2c *mlxsw_i2c; 562 u8 status; 563 int err; 564 565 mlxsw_i2c = devm_kzalloc(&client->dev, sizeof(*mlxsw_i2c), GFP_KERNEL); 566 if (!mlxsw_i2c) 567 return -ENOMEM; 568 569 if (quirks) { 570 if ((quirks->max_read_len && 571 quirks->max_read_len < MLXSW_I2C_BLK_DEF) || 572 (quirks->max_write_len && 573 quirks->max_write_len < MLXSW_I2C_BLK_DEF)) { 574 dev_err(&client->dev, "Insufficient transaction buffer length\n"); 575 return -EOPNOTSUPP; 576 } 577 578 mlxsw_i2c->block_size = max_t(u16, MLXSW_I2C_BLK_DEF, 579 min_t(u16, quirks->max_read_len, 580 quirks->max_write_len)); 581 } else { 582 mlxsw_i2c->block_size = MLXSW_I2C_BLK_DEF; 583 } 584 585 i2c_set_clientdata(client, mlxsw_i2c); 586 mutex_init(&mlxsw_i2c->cmd.lock); 587 588 /* In order to use mailboxes through the i2c, special area is reserved 589 * on the i2c address space that can be used for input and output 590 * mailboxes. Such mailboxes are called local mailboxes. When using a 591 * local mailbox, software should specify 0 as the Input/Output 592 * parameters. The location of the Local Mailbox addresses on the i2c 593 * space can be retrieved through the QUERY_FW command. 594 * For this purpose QUERY_FW is to be issued with opcode modifier equal 595 * 0x01. For such command the output parameter is an immediate value. 596 * Here QUERY_FW command is invoked for ASIC probing and for getting 597 * local mailboxes addresses from immedate output parameters. 598 */ 599 600 /* Prepare and write out Command Interface Register for transaction */ 601 err = mlxsw_i2c_write_cmd(client, mlxsw_i2c, 1); 602 if (err) { 603 dev_err(&client->dev, "Could not start transaction"); 604 goto errout; 605 } 606 607 /* Wait until go bit is cleared. */ 608 err = mlxsw_i2c_wait_go_bit(client, mlxsw_i2c, &status); 609 if (err) { 610 dev_err(&client->dev, "HW semaphore is not released"); 611 goto errout; 612 } 613 614 /* Validate transaction completion status. */ 615 if (status) { 616 dev_err(&client->dev, "Bad transaction completion status %x\n", 617 status); 618 err = -EIO; 619 goto errout; 620 } 621 622 /* Get mailbox offsets. */ 623 err = mlxsw_i2c_get_mbox(client, mlxsw_i2c); 624 if (err < 0) { 625 dev_err(&client->dev, "Fail to get mailboxes\n"); 626 goto errout; 627 } 628 629 dev_info(&client->dev, "%s mb size=%x off=0x%08x out mb size=%x off=0x%08x\n", 630 id->name, mlxsw_i2c->cmd.mb_size_in, 631 mlxsw_i2c->cmd.mb_off_in, mlxsw_i2c->cmd.mb_size_out, 632 mlxsw_i2c->cmd.mb_off_out); 633 634 /* Register device bus. */ 635 mlxsw_i2c->bus_info.device_kind = id->name; 636 mlxsw_i2c->bus_info.device_name = client->name; 637 mlxsw_i2c->bus_info.dev = &client->dev; 638 mlxsw_i2c->bus_info.low_frequency = true; 639 mlxsw_i2c->dev = &client->dev; 640 641 err = mlxsw_core_bus_device_register(&mlxsw_i2c->bus_info, 642 &mlxsw_i2c_bus, mlxsw_i2c, false, 643 NULL); 644 if (err) { 645 dev_err(&client->dev, "Fail to register core bus\n"); 646 return err; 647 } 648 649 return 0; 650 651 errout: 652 i2c_set_clientdata(client, NULL); 653 654 return err; 655 } 656 657 static int mlxsw_i2c_remove(struct i2c_client *client) 658 { 659 struct mlxsw_i2c *mlxsw_i2c = i2c_get_clientdata(client); 660 661 mlxsw_core_bus_device_unregister(mlxsw_i2c->core, false); 662 mutex_destroy(&mlxsw_i2c->cmd.lock); 663 664 return 0; 665 } 666 667 int mlxsw_i2c_driver_register(struct i2c_driver *i2c_driver) 668 { 669 i2c_driver->probe = mlxsw_i2c_probe; 670 i2c_driver->remove = mlxsw_i2c_remove; 671 return i2c_add_driver(i2c_driver); 672 } 673 EXPORT_SYMBOL(mlxsw_i2c_driver_register); 674 675 void mlxsw_i2c_driver_unregister(struct i2c_driver *i2c_driver) 676 { 677 i2c_del_driver(i2c_driver); 678 } 679 EXPORT_SYMBOL(mlxsw_i2c_driver_unregister); 680 681 MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>"); 682 MODULE_DESCRIPTION("Mellanox switch I2C interface driver"); 683 MODULE_LICENSE("Dual BSD/GPL"); 684