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   1/*
   2 *   This file is provided under a GPLv2 license.  When using or
   3 *   redistributing this file, you may do so under that license.
   4 *
   5 *   GPL LICENSE SUMMARY
   6 *
   7 *   Copyright (C) 2016 T-Platforms. All Rights Reserved.
   8 *
   9 *   This program is free software; you can redistribute it and/or modify it
  10 *   under the terms and conditions of the GNU General Public License,
  11 *   version 2, as published by the Free Software Foundation.
  12 *
  13 *   This program is distributed in the hope that it will be useful, but WITHOUT
  14 *   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 *   FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  16 *   more details.
  17 *
  18 *   You should have received a copy of the GNU General Public License along
  19 *   with this program; if not, it can be found <http://www.gnu.org/licenses/>.
  20 *
  21 *   The full GNU General Public License is included in this distribution in
  22 *   the file called "COPYING".
  23 *
  24 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  25 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  26 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  27 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  28 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  29 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  30 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  31 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  32 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  33 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  34 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35 *
  36 * IDT PCIe-switch NTB Linux driver
  37 *
  38 * Contact Information:
  39 * Serge Semin <fancer.lancer@gmail.com>, <Sergey.Semin@t-platforms.ru>
  40 */
  41/*
  42 *           NOTE of the IDT 89HPESx SMBus-slave interface driver
  43 *    This driver primarily is developed to have an access to EEPROM device of
  44 * IDT PCIe-switches. IDT provides a simple SMBus interface to perform IO-
  45 * operations from/to EEPROM, which is located at private (so called Master)
  46 * SMBus of switches. Using that interface this the driver creates a simple
  47 * binary sysfs-file in the device directory:
  48 * /sys/bus/i2c/devices/<bus>-<devaddr>/eeprom
  49 * In case if read-only flag is specified in the dts-node of device desription,
  50 * User-space applications won't be able to write to the EEPROM sysfs-node.
  51 *    Additionally IDT 89HPESx SMBus interface has an ability to write/read
  52 * data of device CSRs. This driver exposes debugf-file to perform simple IO
  53 * operations using that ability for just basic debug purpose. Particularly
  54 * next file is created in the specific debugfs-directory:
  55 * /sys/kernel/debug/idt_csr/
  56 * Format of the debugfs-node is:
  57 * $ cat /sys/kernel/debug/idt_csr/<bus>-<devaddr>/<devname>;
  58 * <CSR address>:<CSR value>
  59 * So reading the content of the file gives current CSR address and it value.
  60 * If User-space application wishes to change current CSR address,
  61 * it can just write a proper value to the sysfs-file:
  62 * $ echo "<CSR address>" > /sys/kernel/debug/idt_csr/<bus>-<devaddr>/<devname>
  63 * If it wants to change the CSR value as well, the format of the write
  64 * operation is:
  65 * $ echo "<CSR address>:<CSR value>" > \
  66 *        /sys/kernel/debug/idt_csr/<bus>-<devaddr>/<devname>;
  67 * CSR address and value can be any of hexadecimal, decimal or octal format.
  68 */
  69
  70#include <linux/kernel.h>
  71#include <linux/init.h>
  72#include <linux/module.h>
  73#include <linux/types.h>
  74#include <linux/sizes.h>
  75#include <linux/slab.h>
  76#include <linux/mutex.h>
  77#include <linux/sysfs.h>
  78#include <linux/debugfs.h>
  79#include <linux/mod_devicetable.h>
  80#include <linux/property.h>
  81#include <linux/i2c.h>
  82#include <linux/pci_ids.h>
  83#include <linux/delay.h>
  84
  85#define IDT_NAME		"89hpesx"
  86#define IDT_89HPESX_DESC	"IDT 89HPESx SMBus-slave interface driver"
  87#define IDT_89HPESX_VER		"1.0"
  88
  89MODULE_DESCRIPTION(IDT_89HPESX_DESC);
  90MODULE_VERSION(IDT_89HPESX_VER);
  91MODULE_LICENSE("GPL v2");
  92MODULE_AUTHOR("T-platforms");
  93
  94/*
  95 * csr_dbgdir - CSR read/write operations Debugfs directory
  96 */
  97static struct dentry *csr_dbgdir;
  98
  99/*
 100 * struct idt_89hpesx_dev - IDT 89HPESx device data structure
 101 * @eesize:	Size of EEPROM in bytes (calculated from "idt,eecompatible")
 102 * @eero:	EEPROM Read-only flag
 103 * @eeaddr:	EEPROM custom address
 104 *
 105 * @inieecmd:	Initial cmd value for EEPROM read/write operations
 106 * @inicsrcmd:	Initial cmd value for CSR read/write operations
 107 * @iniccode:	Initialial command code value for IO-operations
 108 *
 109 * @csr:	CSR address to perform read operation
 110 *
 111 * @smb_write:	SMBus write method
 112 * @smb_read:	SMBus read method
 113 * @smb_mtx:	SMBus mutex
 114 *
 115 * @client:	i2c client used to perform IO operations
 116 *
 117 * @ee_file:	EEPROM read/write sysfs-file
 118 */
 119struct idt_smb_seq;
 120struct idt_89hpesx_dev {
 121	u32 eesize;
 122	bool eero;
 123	u8 eeaddr;
 124
 125	u8 inieecmd;
 126	u8 inicsrcmd;
 127	u8 iniccode;
 128
 129	u16 csr;
 130
 131	int (*smb_write)(struct idt_89hpesx_dev *, const struct idt_smb_seq *);
 132	int (*smb_read)(struct idt_89hpesx_dev *, struct idt_smb_seq *);
 133	struct mutex smb_mtx;
 134
 135	struct i2c_client *client;
 136
 137	struct bin_attribute *ee_file;
 138	struct dentry *csr_dir;
 139};
 140
 141/*
 142 * struct idt_smb_seq - sequence of data to be read/written from/to IDT 89HPESx
 143 * @ccode:	SMBus command code
 144 * @bytecnt:	Byte count of operation
 145 * @data:	Data to by written
 146 */
 147struct idt_smb_seq {
 148	u8 ccode;
 149	u8 bytecnt;
 150	u8 *data;
 151};
 152
 153/*
 154 * struct idt_eeprom_seq - sequence of data to be read/written from/to EEPROM
 155 * @cmd:	Transaction CMD
 156 * @eeaddr:	EEPROM custom address
 157 * @memaddr:	Internal memory address of EEPROM
 158 * @data:	Data to be written at the memory address
 159 */
 160struct idt_eeprom_seq {
 161	u8 cmd;
 162	u8 eeaddr;
 163	u16 memaddr;
 164	u8 data;
 165} __packed;
 166
 167/*
 168 * struct idt_csr_seq - sequence of data to be read/written from/to CSR
 169 * @cmd:	Transaction CMD
 170 * @csraddr:	Internal IDT device CSR address
 171 * @data:	Data to be read/written from/to the CSR address
 172 */
 173struct idt_csr_seq {
 174	u8 cmd;
 175	u16 csraddr;
 176	u32 data;
 177} __packed;
 178
 179/*
 180 * SMBus command code macros
 181 * @CCODE_END:		Indicates the end of transaction
 182 * @CCODE_START:	Indicates the start of transaction
 183 * @CCODE_CSR:		CSR read/write transaction
 184 * @CCODE_EEPROM:	EEPROM read/write transaction
 185 * @CCODE_BYTE:		Supplied data has BYTE length
 186 * @CCODE_WORD:		Supplied data has WORD length
 187 * @CCODE_BLOCK:	Supplied data has variable length passed in bytecnt
 188 *			byte right following CCODE byte
 189 */
 190#define CCODE_END	((u8)0x01)
 191#define CCODE_START	((u8)0x02)
 192#define CCODE_CSR	((u8)0x00)
 193#define CCODE_EEPROM	((u8)0x04)
 194#define CCODE_BYTE	((u8)0x00)
 195#define CCODE_WORD	((u8)0x20)
 196#define CCODE_BLOCK	((u8)0x40)
 197#define CCODE_PEC	((u8)0x80)
 198
 199/*
 200 * EEPROM command macros
 201 * @EEPROM_OP_WRITE:	EEPROM write operation
 202 * @EEPROM_OP_READ:	EEPROM read operation
 203 * @EEPROM_USA:		Use specified address of EEPROM
 204 * @EEPROM_NAERR:	EEPROM device is not ready to respond
 205 * @EEPROM_LAERR:	EEPROM arbitration loss error
 206 * @EEPROM_MSS:		EEPROM misplace start & stop bits error
 207 * @EEPROM_WR_CNT:	Bytes count to perform write operation
 208 * @EEPROM_WRRD_CNT:	Bytes count to write before reading
 209 * @EEPROM_RD_CNT:	Bytes count to perform read operation
 210 * @EEPROM_DEF_SIZE:	Fall back size of EEPROM
 211 * @EEPROM_DEF_ADDR:	Defatul EEPROM address
 212 * @EEPROM_TOUT:	Timeout before retry read operation if eeprom is busy
 213 */
 214#define EEPROM_OP_WRITE	((u8)0x00)
 215#define EEPROM_OP_READ	((u8)0x01)
 216#define EEPROM_USA	((u8)0x02)
 217#define EEPROM_NAERR	((u8)0x08)
 218#define EEPROM_LAERR    ((u8)0x10)
 219#define EEPROM_MSS	((u8)0x20)
 220#define EEPROM_WR_CNT	((u8)5)
 221#define EEPROM_WRRD_CNT	((u8)4)
 222#define EEPROM_RD_CNT	((u8)5)
 223#define EEPROM_DEF_SIZE	((u16)4096)
 224#define EEPROM_DEF_ADDR	((u8)0x50)
 225#define EEPROM_TOUT	(100)
 226
 227/*
 228 * CSR command macros
 229 * @CSR_DWE:		Enable all four bytes of the operation
 230 * @CSR_OP_WRITE:	CSR write operation
 231 * @CSR_OP_READ:	CSR read operation
 232 * @CSR_RERR:		Read operation error
 233 * @CSR_WERR:		Write operation error
 234 * @CSR_WR_CNT:		Bytes count to perform write operation
 235 * @CSR_WRRD_CNT:	Bytes count to write before reading
 236 * @CSR_RD_CNT:		Bytes count to perform read operation
 237 * @CSR_MAX:		Maximum CSR address
 238 * @CSR_DEF:		Default CSR address
 239 * @CSR_REAL_ADDR:	CSR real unshifted address
 240 */
 241#define CSR_DWE			((u8)0x0F)
 242#define CSR_OP_WRITE		((u8)0x00)
 243#define CSR_OP_READ		((u8)0x10)
 244#define CSR_RERR		((u8)0x40)
 245#define CSR_WERR		((u8)0x80)
 246#define CSR_WR_CNT		((u8)7)
 247#define CSR_WRRD_CNT		((u8)3)
 248#define CSR_RD_CNT		((u8)7)
 249#define CSR_MAX			((u32)0x3FFFF)
 250#define CSR_DEF			((u16)0x0000)
 251#define CSR_REAL_ADDR(val)	((unsigned int)val << 2)
 252
 253/*
 254 * IDT 89HPESx basic register
 255 * @IDT_VIDDID_CSR:	PCIe VID and DID of IDT 89HPESx
 256 * @IDT_VID_MASK:	Mask of VID
 257 */
 258#define IDT_VIDDID_CSR	((u32)0x0000)
 259#define IDT_VID_MASK	((u32)0xFFFF)
 260
 261/*
 262 * IDT 89HPESx can send NACK when new command is sent before previous one
 263 * fininshed execution. In this case driver retries operation
 264 * certain times.
 265 * @RETRY_CNT:		Number of retries before giving up and fail
 266 * @idt_smb_safe:	Generate a retry loop on corresponding SMBus method
 267 */
 268#define RETRY_CNT (128)
 269#define idt_smb_safe(ops, args...) ({ \
 270	int __retry = RETRY_CNT; \
 271	s32 __sts; \
 272	do { \
 273		__sts = i2c_smbus_ ## ops ## _data(args); \
 274	} while (__retry-- && __sts < 0); \
 275	__sts; \
 276})
 277
 278/*===========================================================================
 279 *                         i2c bus level IO-operations
 280 *===========================================================================
 281 */
 282
 283/*
 284 * idt_smb_write_byte() - SMBus write method when I2C_SMBUS_BYTE_DATA operation
 285 *                        is only available
 286 * @pdev:	Pointer to the driver data
 287 * @seq:	Sequence of data to be written
 288 */
 289static int idt_smb_write_byte(struct idt_89hpesx_dev *pdev,
 290			      const struct idt_smb_seq *seq)
 291{
 292	s32 sts;
 293	u8 ccode;
 294	int idx;
 295
 296	/* Loop over the supplied data sending byte one-by-one */
 297	for (idx = 0; idx < seq->bytecnt; idx++) {
 298		/* Collect the command code byte */
 299		ccode = seq->ccode | CCODE_BYTE;
 300		if (idx == 0)
 301			ccode |= CCODE_START;
 302		if (idx == seq->bytecnt - 1)
 303			ccode |= CCODE_END;
 304
 305		/* Send data to the device */
 306		sts = idt_smb_safe(write_byte, pdev->client, ccode,
 307			seq->data[idx]);
 308		if (sts != 0)
 309			return (int)sts;
 310	}
 311
 312	return 0;
 313}
 314
 315/*
 316 * idt_smb_read_byte() - SMBus read method when I2C_SMBUS_BYTE_DATA operation
 317 *                        is only available
 318 * @pdev:	Pointer to the driver data
 319 * @seq:	Buffer to read data to
 320 */
 321static int idt_smb_read_byte(struct idt_89hpesx_dev *pdev,
 322			     struct idt_smb_seq *seq)
 323{
 324	s32 sts;
 325	u8 ccode;
 326	int idx;
 327
 328	/* Loop over the supplied buffer receiving byte one-by-one */
 329	for (idx = 0; idx < seq->bytecnt; idx++) {
 330		/* Collect the command code byte */
 331		ccode = seq->ccode | CCODE_BYTE;
 332		if (idx == 0)
 333			ccode |= CCODE_START;
 334		if (idx == seq->bytecnt - 1)
 335			ccode |= CCODE_END;
 336
 337		/* Read data from the device */
 338		sts = idt_smb_safe(read_byte, pdev->client, ccode);
 339		if (sts < 0)
 340			return (int)sts;
 341
 342		seq->data[idx] = (u8)sts;
 343	}
 344
 345	return 0;
 346}
 347
 348/*
 349 * idt_smb_write_word() - SMBus write method when I2C_SMBUS_BYTE_DATA and
 350 *                        I2C_FUNC_SMBUS_WORD_DATA operations are available
 351 * @pdev:	Pointer to the driver data
 352 * @seq:	Sequence of data to be written
 353 */
 354static int idt_smb_write_word(struct idt_89hpesx_dev *pdev,
 355			      const struct idt_smb_seq *seq)
 356{
 357	s32 sts;
 358	u8 ccode;
 359	int idx, evencnt;
 360
 361	/* Calculate the even count of data to send */
 362	evencnt = seq->bytecnt - (seq->bytecnt % 2);
 363
 364	/* Loop over the supplied data sending two bytes at a time */
 365	for (idx = 0; idx < evencnt; idx += 2) {
 366		/* Collect the command code byte */
 367		ccode = seq->ccode | CCODE_WORD;
 368		if (idx == 0)
 369			ccode |= CCODE_START;
 370		if (idx == evencnt - 2)
 371			ccode |= CCODE_END;
 372
 373		/* Send word data to the device */
 374		sts = idt_smb_safe(write_word, pdev->client, ccode,
 375			*(u16 *)&seq->data[idx]);
 376		if (sts != 0)
 377			return (int)sts;
 378	}
 379
 380	/* If there is odd number of bytes then send just one last byte */
 381	if (seq->bytecnt != evencnt) {
 382		/* Collect the command code byte */
 383		ccode = seq->ccode | CCODE_BYTE | CCODE_END;
 384		if (idx == 0)
 385			ccode |= CCODE_START;
 386
 387		/* Send byte data to the device */
 388		sts = idt_smb_safe(write_byte, pdev->client, ccode,
 389			seq->data[idx]);
 390		if (sts != 0)
 391			return (int)sts;
 392	}
 393
 394	return 0;
 395}
 396
 397/*
 398 * idt_smb_read_word() - SMBus read method when I2C_SMBUS_BYTE_DATA and
 399 *                       I2C_FUNC_SMBUS_WORD_DATA operations are available
 400 * @pdev:	Pointer to the driver data
 401 * @seq:	Buffer to read data to
 402 */
 403static int idt_smb_read_word(struct idt_89hpesx_dev *pdev,
 404			     struct idt_smb_seq *seq)
 405{
 406	s32 sts;
 407	u8 ccode;
 408	int idx, evencnt;
 409
 410	/* Calculate the even count of data to send */
 411	evencnt = seq->bytecnt - (seq->bytecnt % 2);
 412
 413	/* Loop over the supplied data reading two bytes at a time */
 414	for (idx = 0; idx < evencnt; idx += 2) {
 415		/* Collect the command code byte */
 416		ccode = seq->ccode | CCODE_WORD;
 417		if (idx == 0)
 418			ccode |= CCODE_START;
 419		if (idx == evencnt - 2)
 420			ccode |= CCODE_END;
 421
 422		/* Read word data from the device */
 423		sts = idt_smb_safe(read_word, pdev->client, ccode);
 424		if (sts < 0)
 425			return (int)sts;
 426
 427		*(u16 *)&seq->data[idx] = (u16)sts;
 428	}
 429
 430	/* If there is odd number of bytes then receive just one last byte */
 431	if (seq->bytecnt != evencnt) {
 432		/* Collect the command code byte */
 433		ccode = seq->ccode | CCODE_BYTE | CCODE_END;
 434		if (idx == 0)
 435			ccode |= CCODE_START;
 436
 437		/* Read last data byte from the device */
 438		sts = idt_smb_safe(read_byte, pdev->client, ccode);
 439		if (sts < 0)
 440			return (int)sts;
 441
 442		seq->data[idx] = (u8)sts;
 443	}
 444
 445	return 0;
 446}
 447
 448/*
 449 * idt_smb_write_block() - SMBus write method when I2C_SMBUS_BLOCK_DATA
 450 *                         operation is available
 451 * @pdev:	Pointer to the driver data
 452 * @seq:	Sequence of data to be written
 453 */
 454static int idt_smb_write_block(struct idt_89hpesx_dev *pdev,
 455			       const struct idt_smb_seq *seq)
 456{
 457	u8 ccode;
 458
 459	/* Return error if too much data passed to send */
 460	if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX)
 461		return -EINVAL;
 462
 463	/* Collect the command code byte */
 464	ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END;
 465
 466	/* Send block of data to the device */
 467	return idt_smb_safe(write_block, pdev->client, ccode, seq->bytecnt,
 468		seq->data);
 469}
 470
 471/*
 472 * idt_smb_read_block() - SMBus read method when I2C_SMBUS_BLOCK_DATA
 473 *                        operation is available
 474 * @pdev:	Pointer to the driver data
 475 * @seq:	Buffer to read data to
 476 */
 477static int idt_smb_read_block(struct idt_89hpesx_dev *pdev,
 478			      struct idt_smb_seq *seq)
 479{
 480	s32 sts;
 481	u8 ccode;
 482
 483	/* Return error if too much data passed to send */
 484	if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX)
 485		return -EINVAL;
 486
 487	/* Collect the command code byte */
 488	ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END;
 489
 490	/* Read block of data from the device */
 491	sts = idt_smb_safe(read_block, pdev->client, ccode, seq->data);
 492	if (sts != seq->bytecnt)
 493		return (sts < 0 ? sts : -ENODATA);
 494
 495	return 0;
 496}
 497
 498/*
 499 * idt_smb_write_i2c_block() - SMBus write method when I2C_SMBUS_I2C_BLOCK_DATA
 500 *                             operation is available
 501 * @pdev:	Pointer to the driver data
 502 * @seq:	Sequence of data to be written
 503 *
 504 * NOTE It's usual SMBus write block operation, except the actual data length is
 505 * sent as first byte of data
 506 */
 507static int idt_smb_write_i2c_block(struct idt_89hpesx_dev *pdev,
 508				   const struct idt_smb_seq *seq)
 509{
 510	u8 ccode, buf[I2C_SMBUS_BLOCK_MAX + 1];
 511
 512	/* Return error if too much data passed to send */
 513	if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX)
 514		return -EINVAL;
 515
 516	/* Collect the data to send. Length byte must be added prior the data */
 517	buf[0] = seq->bytecnt;
 518	memcpy(&buf[1], seq->data, seq->bytecnt);
 519
 520	/* Collect the command code byte */
 521	ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END;
 522
 523	/* Send length and block of data to the device */
 524	return idt_smb_safe(write_i2c_block, pdev->client, ccode,
 525		seq->bytecnt + 1, buf);
 526}
 527
 528/*
 529 * idt_smb_read_i2c_block() - SMBus read method when I2C_SMBUS_I2C_BLOCK_DATA
 530 *                            operation is available
 531 * @pdev:	Pointer to the driver data
 532 * @seq:	Buffer to read data to
 533 *
 534 * NOTE It's usual SMBus read block operation, except the actual data length is
 535 * retrieved as first byte of data
 536 */
 537static int idt_smb_read_i2c_block(struct idt_89hpesx_dev *pdev,
 538				  struct idt_smb_seq *seq)
 539{
 540	u8 ccode, buf[I2C_SMBUS_BLOCK_MAX + 1];
 541	s32 sts;
 542
 543	/* Return error if too much data passed to send */
 544	if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX)
 545		return -EINVAL;
 546
 547	/* Collect the command code byte */
 548	ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END;
 549
 550	/* Read length and block of data from the device */
 551	sts = idt_smb_safe(read_i2c_block, pdev->client, ccode,
 552		seq->bytecnt + 1, buf);
 553	if (sts != seq->bytecnt + 1)
 554		return (sts < 0 ? sts : -ENODATA);
 555	if (buf[0] != seq->bytecnt)
 556		return -ENODATA;
 557
 558	/* Copy retrieved data to the output data buffer */
 559	memcpy(seq->data, &buf[1], seq->bytecnt);
 560
 561	return 0;
 562}
 563
 564/*===========================================================================
 565 *                          EEPROM IO-operations
 566 *===========================================================================
 567 */
 568
 569/*
 570 * idt_eeprom_read_byte() - read just one byte from EEPROM
 571 * @pdev:	Pointer to the driver data
 572 * @memaddr:	Start EEPROM memory address
 573 * @data:	Data to be written to EEPROM
 574 */
 575static int idt_eeprom_read_byte(struct idt_89hpesx_dev *pdev, u16 memaddr,
 576				u8 *data)
 577{
 578	struct device *dev = &pdev->client->dev;
 579	struct idt_eeprom_seq eeseq;
 580	struct idt_smb_seq smbseq;
 581	int ret, retry;
 582
 583	/* Initialize SMBus sequence fields */
 584	smbseq.ccode = pdev->iniccode | CCODE_EEPROM;
 585	smbseq.data = (u8 *)&eeseq;
 586
 587	/*
 588	 * Sometimes EEPROM may respond with NACK if it's busy with previous
 589	 * operation, so we need to perform a few attempts of read cycle
 590	 */
 591	retry = RETRY_CNT;
 592	do {
 593		/* Send EEPROM memory address to read data from */
 594		smbseq.bytecnt = EEPROM_WRRD_CNT;
 595		eeseq.cmd = pdev->inieecmd | EEPROM_OP_READ;
 596		eeseq.eeaddr = pdev->eeaddr;
 597		eeseq.memaddr = cpu_to_le16(memaddr);
 598		ret = pdev->smb_write(pdev, &smbseq);
 599		if (ret != 0) {
 600			dev_err(dev, "Failed to init eeprom addr 0x%02hhx",
 601				memaddr);
 602			break;
 603		}
 604
 605		/* Perform read operation */
 606		smbseq.bytecnt = EEPROM_RD_CNT;
 607		ret = pdev->smb_read(pdev, &smbseq);
 608		if (ret != 0) {
 609			dev_err(dev, "Failed to read eeprom data 0x%02hhx",
 610				memaddr);
 611			break;
 612		}
 613
 614		/* Restart read operation if the device is busy */
 615		if (retry && (eeseq.cmd & EEPROM_NAERR)) {
 616			dev_dbg(dev, "EEPROM busy, retry reading after %d ms",
 617				EEPROM_TOUT);
 618			msleep(EEPROM_TOUT);
 619			continue;
 620		}
 621
 622		/* Check whether IDT successfully read data from EEPROM */
 623		if (eeseq.cmd & (EEPROM_NAERR | EEPROM_LAERR | EEPROM_MSS)) {
 624			dev_err(dev,
 625				"Communication with eeprom failed, cmd 0x%hhx",
 626				eeseq.cmd);
 627			ret = -EREMOTEIO;
 628			break;
 629		}
 630
 631		/* Save retrieved data and exit the loop */
 632		*data = eeseq.data;
 633		break;
 634	} while (retry--);
 635
 636	/* Return the status of operation */
 637	return ret;
 638}
 639
 640/*
 641 * idt_eeprom_write() - EEPROM write operation
 642 * @pdev:	Pointer to the driver data
 643 * @memaddr:	Start EEPROM memory address
 644 * @len:	Length of data to be written
 645 * @data:	Data to be written to EEPROM
 646 */
 647static int idt_eeprom_write(struct idt_89hpesx_dev *pdev, u16 memaddr, u16 len,
 648			    const u8 *data)
 649{
 650	struct device *dev = &pdev->client->dev;
 651	struct idt_eeprom_seq eeseq;
 652	struct idt_smb_seq smbseq;
 653	int ret;
 654	u16 idx;
 655
 656	/* Initialize SMBus sequence fields */
 657	smbseq.ccode = pdev->iniccode | CCODE_EEPROM;
 658	smbseq.data = (u8 *)&eeseq;
 659
 660	/* Send data byte-by-byte, checking if it is successfully written */
 661	for (idx = 0; idx < len; idx++, memaddr++) {
 662		/* Lock IDT SMBus device */
 663		mutex_lock(&pdev->smb_mtx);
 664
 665		/* Perform write operation */
 666		smbseq.bytecnt = EEPROM_WR_CNT;
 667		eeseq.cmd = pdev->inieecmd | EEPROM_OP_WRITE;
 668		eeseq.eeaddr = pdev->eeaddr;
 669		eeseq.memaddr = cpu_to_le16(memaddr);
 670		eeseq.data = data[idx];
 671		ret = pdev->smb_write(pdev, &smbseq);
 672		if (ret != 0) {
 673			dev_err(dev,
 674				"Failed to write 0x%04hx:0x%02hhx to eeprom",
 675				memaddr, data[idx]);
 676			goto err_mutex_unlock;
 677		}
 678
 679		/*
 680		 * Check whether the data is successfully written by reading
 681		 * from the same EEPROM memory address.
 682		 */
 683		eeseq.data = ~data[idx];
 684		ret = idt_eeprom_read_byte(pdev, memaddr, &eeseq.data);
 685		if (ret != 0)
 686			goto err_mutex_unlock;
 687
 688		/* Check whether the read byte is the same as written one */
 689		if (eeseq.data != data[idx]) {
 690			dev_err(dev, "Values don't match 0x%02hhx != 0x%02hhx",
 691				eeseq.data, data[idx]);
 692			ret = -EREMOTEIO;
 693			goto err_mutex_unlock;
 694		}
 695
 696		/* Unlock IDT SMBus device */
 697err_mutex_unlock:
 698		mutex_unlock(&pdev->smb_mtx);
 699		if (ret != 0)
 700			return ret;
 701	}
 702
 703	return 0;
 704}
 705
 706/*
 707 * idt_eeprom_read() - EEPROM read operation
 708 * @pdev:	Pointer to the driver data
 709 * @memaddr:	Start EEPROM memory address
 710 * @len:	Length of data to read
 711 * @buf:	Buffer to read data to
 712 */
 713static int idt_eeprom_read(struct idt_89hpesx_dev *pdev, u16 memaddr, u16 len,
 714			   u8 *buf)
 715{
 716	int ret;
 717	u16 idx;
 718
 719	/* Read data byte-by-byte, retrying if it wasn't successful */
 720	for (idx = 0; idx < len; idx++, memaddr++) {
 721		/* Lock IDT SMBus device */
 722		mutex_lock(&pdev->smb_mtx);
 723
 724		/* Just read the byte to the buffer */
 725		ret = idt_eeprom_read_byte(pdev, memaddr, &buf[idx]);
 726
 727		/* Unlock IDT SMBus device */
 728		mutex_unlock(&pdev->smb_mtx);
 729
 730		/* Return error if read operation failed */
 731		if (ret != 0)
 732			return ret;
 733	}
 734
 735	return 0;
 736}
 737
 738/*===========================================================================
 739 *                          CSR IO-operations
 740 *===========================================================================
 741 */
 742
 743/*
 744 * idt_csr_write() - CSR write operation
 745 * @pdev:	Pointer to the driver data
 746 * @csraddr:	CSR address (with no two LS bits)
 747 * @data:	Data to be written to CSR
 748 */
 749static int idt_csr_write(struct idt_89hpesx_dev *pdev, u16 csraddr,
 750			 const u32 data)
 751{
 752	struct device *dev = &pdev->client->dev;
 753	struct idt_csr_seq csrseq;
 754	struct idt_smb_seq smbseq;
 755	int ret;
 756
 757	/* Initialize SMBus sequence fields */
 758	smbseq.ccode = pdev->iniccode | CCODE_CSR;
 759	smbseq.data = (u8 *)&csrseq;
 760
 761	/* Lock IDT SMBus device */
 762	mutex_lock(&pdev->smb_mtx);
 763
 764	/* Perform write operation */
 765	smbseq.bytecnt = CSR_WR_CNT;
 766	csrseq.cmd = pdev->inicsrcmd | CSR_OP_WRITE;
 767	csrseq.csraddr = cpu_to_le16(csraddr);
 768	csrseq.data = cpu_to_le32(data);
 769	ret = pdev->smb_write(pdev, &smbseq);
 770	if (ret != 0) {
 771		dev_err(dev, "Failed to write 0x%04x: 0x%04x to csr",
 772			CSR_REAL_ADDR(csraddr), data);
 773		goto err_mutex_unlock;
 774	}
 775
 776	/* Send CSR address to read data from */
 777	smbseq.bytecnt = CSR_WRRD_CNT;
 778	csrseq.cmd = pdev->inicsrcmd | CSR_OP_READ;
 779	ret = pdev->smb_write(pdev, &smbseq);
 780	if (ret != 0) {
 781		dev_err(dev, "Failed to init csr address 0x%04x",
 782			CSR_REAL_ADDR(csraddr));
 783		goto err_mutex_unlock;
 784	}
 785
 786	/* Perform read operation */
 787	smbseq.bytecnt = CSR_RD_CNT;
 788	ret = pdev->smb_read(pdev, &smbseq);
 789	if (ret != 0) {
 790		dev_err(dev, "Failed to read csr 0x%04x",
 791			CSR_REAL_ADDR(csraddr));
 792		goto err_mutex_unlock;
 793	}
 794
 795	/* Check whether IDT successfully retrieved CSR data */
 796	if (csrseq.cmd & (CSR_RERR | CSR_WERR)) {
 797		dev_err(dev, "IDT failed to perform CSR r/w");
 798		ret = -EREMOTEIO;
 799		goto err_mutex_unlock;
 800	}
 801
 802	/* Unlock IDT SMBus device */
 803err_mutex_unlock:
 804	mutex_unlock(&pdev->smb_mtx);
 805
 806	return ret;
 807}
 808
 809/*
 810 * idt_csr_read() - CSR read operation
 811 * @pdev:	Pointer to the driver data
 812 * @csraddr:	CSR address (with no two LS bits)
 813 * @data:	Data to be written to CSR
 814 */
 815static int idt_csr_read(struct idt_89hpesx_dev *pdev, u16 csraddr, u32 *data)
 816{
 817	struct device *dev = &pdev->client->dev;
 818	struct idt_csr_seq csrseq;
 819	struct idt_smb_seq smbseq;
 820	int ret;
 821
 822	/* Initialize SMBus sequence fields */
 823	smbseq.ccode = pdev->iniccode | CCODE_CSR;
 824	smbseq.data = (u8 *)&csrseq;
 825
 826	/* Lock IDT SMBus device */
 827	mutex_lock(&pdev->smb_mtx);
 828
 829	/* Send CSR register address before reading it */
 830	smbseq.bytecnt = CSR_WRRD_CNT;
 831	csrseq.cmd = pdev->inicsrcmd | CSR_OP_READ;
 832	csrseq.csraddr = cpu_to_le16(csraddr);
 833	ret = pdev->smb_write(pdev, &smbseq);
 834	if (ret != 0) {
 835		dev_err(dev, "Failed to init csr address 0x%04x",
 836			CSR_REAL_ADDR(csraddr));
 837		goto err_mutex_unlock;
 838	}
 839
 840	/* Perform read operation */
 841	smbseq.bytecnt = CSR_RD_CNT;
 842	ret = pdev->smb_read(pdev, &smbseq);
 843	if (ret != 0) {
 844		dev_err(dev, "Failed to read csr 0x%04hx",
 845			CSR_REAL_ADDR(csraddr));
 846		goto err_mutex_unlock;
 847	}
 848
 849	/* Check whether IDT successfully retrieved CSR data */
 850	if (csrseq.cmd & (CSR_RERR | CSR_WERR)) {
 851		dev_err(dev, "IDT failed to perform CSR r/w");
 852		ret = -EREMOTEIO;
 853		goto err_mutex_unlock;
 854	}
 855
 856	/* Save data retrieved from IDT */
 857	*data = le32_to_cpu(csrseq.data);
 858
 859	/* Unlock IDT SMBus device */
 860err_mutex_unlock:
 861	mutex_unlock(&pdev->smb_mtx);
 862
 863	return ret;
 864}
 865
 866/*===========================================================================
 867 *                          Sysfs/debugfs-nodes IO-operations
 868 *===========================================================================
 869 */
 870
 871/*
 872 * eeprom_write() - EEPROM sysfs-node write callback
 873 * @filep:	Pointer to the file system node
 874 * @kobj:	Pointer to the kernel object related to the sysfs-node
 875 * @attr:	Attributes of the file
 876 * @buf:	Buffer to write data to
 877 * @off:	Offset at which data should be written to
 878 * @count:	Number of bytes to write
 879 */
 880static ssize_t eeprom_write(struct file *filp, struct kobject *kobj,
 881			    struct bin_attribute *attr,
 882			    char *buf, loff_t off, size_t count)
 883{
 884	struct idt_89hpesx_dev *pdev;
 885	int ret;
 886
 887	/* Retrieve driver data */
 888	pdev = dev_get_drvdata(kobj_to_dev(kobj));
 889
 890	/* Perform EEPROM write operation */
 891	ret = idt_eeprom_write(pdev, (u16)off, (u16)count, (u8 *)buf);
 892	return (ret != 0 ? ret : count);
 893}
 894
 895/*
 896 * eeprom_read() - EEPROM sysfs-node read callback
 897 * @filep:	Pointer to the file system node
 898 * @kobj:	Pointer to the kernel object related to the sysfs-node
 899 * @attr:	Attributes of the file
 900 * @buf:	Buffer to write data to
 901 * @off:	Offset at which data should be written to
 902 * @count:	Number of bytes to write
 903 */
 904static ssize_t eeprom_read(struct file *filp, struct kobject *kobj,
 905			   struct bin_attribute *attr,
 906			   char *buf, loff_t off, size_t count)
 907{
 908	struct idt_89hpesx_dev *pdev;
 909	int ret;
 910
 911	/* Retrieve driver data */
 912	pdev = dev_get_drvdata(kobj_to_dev(kobj));
 913
 914	/* Perform EEPROM read operation */
 915	ret = idt_eeprom_read(pdev, (u16)off, (u16)count, (u8 *)buf);
 916	return (ret != 0 ? ret : count);
 917}
 918
 919/*
 920 * idt_dbgfs_csr_write() - CSR debugfs-node write callback
 921 * @filep:	Pointer to the file system file descriptor
 922 * @buf:	Buffer to read data from
 923 * @count:	Size of the buffer
 924 * @offp:	Offset within the file
 925 *
 926 * It accepts either "0x<reg addr>:0x<value>" for saving register address
 927 * and writing value to specified DWORD register or "0x<reg addr>" for
 928 * just saving register address in order to perform next read operation.
 929 *
 930 * WARNING No spaces are allowed. Incoming string must be strictly formated as:
 931 * "<reg addr>:<value>". Register address must be aligned within 4 bytes
 932 * (one DWORD).
 933 */
 934static ssize_t idt_dbgfs_csr_write(struct file *filep, const char __user *ubuf,
 935				   size_t count, loff_t *offp)
 936{
 937	struct idt_89hpesx_dev *pdev = filep->private_data;
 938	char *colon_ch, *csraddr_str, *csrval_str;
 939	int ret, csraddr_len;
 940	u32 csraddr, csrval;
 941	char *buf;
 942
 943	/* Copy data from User-space */
 944	buf = kmalloc(count + 1, GFP_KERNEL);
 945	if (!buf)
 946		return -ENOMEM;
 947
 948	ret = simple_write_to_buffer(buf, count, offp, ubuf, count);
 949	if (ret < 0)
 950		goto free_buf;
 951	buf[count] = 0;
 952
 953	/* Find position of colon in the buffer */
 954	colon_ch = strnchr(buf, count, ':');
 955
 956	/*
 957	 * If there is colon passed then new CSR value should be parsed as
 958	 * well, so allocate buffer for CSR address substring.
 959	 * If no colon is found, then string must have just one number with
 960	 * no new CSR value
 961	 */
 962	if (colon_ch != NULL) {
 963		csraddr_len = colon_ch - buf;
 964		csraddr_str =
 965			kmalloc(csraddr_len + 1, GFP_KERNEL);
 966		if (csraddr_str == NULL) {
 967			ret = -ENOMEM;
 968			goto free_buf;
 969		}
 970		/* Copy the register address to the substring buffer */
 971		strncpy(csraddr_str, buf, csraddr_len);
 972		csraddr_str[csraddr_len] = '\0';
 973		/* Register value must follow the colon */
 974		csrval_str = colon_ch + 1;
 975	} else /* if (str_colon == NULL) */ {
 976		csraddr_str = (char *)buf; /* Just to shut warning up */
 977		csraddr_len = strnlen(csraddr_str, count);
 978		csrval_str = NULL;
 979	}
 980
 981	/* Convert CSR address to u32 value */
 982	ret = kstrtou32(csraddr_str, 0, &csraddr);
 983	if (ret != 0)
 984		goto free_csraddr_str;
 985
 986	/* Check whether passed register address is valid */
 987	if (csraddr > CSR_MAX || !IS_ALIGNED(csraddr, SZ_4)) {
 988		ret = -EINVAL;
 989		goto free_csraddr_str;
 990	}
 991
 992	/* Shift register address to the right so to have u16 address */
 993	pdev->csr = (csraddr >> 2);
 994
 995	/* Parse new CSR value and send it to IDT, if colon has been found */
 996	if (colon_ch != NULL) {
 997		ret = kstrtou32(csrval_str, 0, &csrval);
 998		if (ret != 0)
 999			goto free_csraddr_str;
1000
1001		ret = idt_csr_write(pdev, pdev->csr, csrval);
1002		if (ret != 0)
1003			goto free_csraddr_str;
1004	}
1005
1006	/* Free memory only if colon has been found */
1007free_csraddr_str:
1008	if (colon_ch != NULL)
1009		kfree(csraddr_str);
1010
1011	/* Free buffer allocated for data retrieved from User-space */
1012free_buf:
1013	kfree(buf);
1014
1015	return (ret != 0 ? ret : count);
1016}
1017
1018/*
1019 * idt_dbgfs_csr_read() - CSR debugfs-node read callback
1020 * @filep:	Pointer to the file system file descriptor
1021 * @buf:	Buffer to write data to
1022 * @count:	Size of the buffer
1023 * @offp:	Offset within the file
1024 *
1025 * It just prints the pair "0x<reg addr>:0x<value>" to passed buffer.
1026 */
1027#define CSRBUF_SIZE	((size_t)32)
1028static ssize_t idt_dbgfs_csr_read(struct file *filep, char __user *ubuf,
1029				  size_t count, loff_t *offp)
1030{
1031	struct idt_89hpesx_dev *pdev = filep->private_data;
1032	u32 csraddr, csrval;
1033	char buf[CSRBUF_SIZE];
1034	int ret, size;
1035
1036	/* Perform CSR read operation */
1037	ret = idt_csr_read(pdev, pdev->csr, &csrval);
1038	if (ret != 0)
1039		return ret;
1040
1041	/* Shift register address to the left so to have real address */
1042	csraddr = ((u32)pdev->csr << 2);
1043
1044	/* Print the "0x<reg addr>:0x<value>" to buffer */
1045	size = snprintf(buf, CSRBUF_SIZE, "0x%05x:0x%08x\n",
1046		(unsigned int)csraddr, (unsigned int)csrval);
1047
1048	/* Copy data to User-space */
1049	return simple_read_from_buffer(ubuf, count, offp, buf, size);
1050}
1051
1052/*
1053 * eeprom_attribute - EEPROM sysfs-node attributes
1054 *
1055 * NOTE Size will be changed in compliance with OF node. EEPROM attribute will
1056 * be read-only as well if the corresponding flag is specified in OF node.
1057 */
1058static BIN_ATTR_RW(eeprom, EEPROM_DEF_SIZE);
1059
1060/*
1061 * csr_dbgfs_ops - CSR debugfs-node read/write operations
1062 */
1063static const struct file_operations csr_dbgfs_ops = {
1064	.owner = THIS_MODULE,
1065	.open = simple_open,
1066	.write = idt_dbgfs_csr_write,
1067	.read = idt_dbgfs_csr_read
1068};
1069
1070/*===========================================================================
1071 *                       Driver init/deinit methods
1072 *===========================================================================
1073 */
1074
1075/*
1076 * idt_set_defval() - disable EEPROM access by default
1077 * @pdev:	Pointer to the driver data
1078 */
1079static void idt_set_defval(struct idt_89hpesx_dev *pdev)
1080{
1081	/* If OF info is missing then use next values */
1082	pdev->eesize = 0;
1083	pdev->eero = true;
1084	pdev->inieecmd = 0;
1085	pdev->eeaddr = 0;
1086}
1087
1088static const struct i2c_device_id ee_ids[];
1089
1090/*
1091 * idt_ee_match_id() - check whether the node belongs to compatible EEPROMs
1092 */
1093static const struct i2c_device_id *idt_ee_match_id(struct fwnode_handle *fwnode)
1094{
1095	const struct i2c_device_id *id = ee_ids;
1096	const char *compatible, *p;
1097	char devname[I2C_NAME_SIZE];
1098	int ret;
1099
1100	ret = fwnode_property_read_string(fwnode, "compatible", &compatible);
1101	if (ret)
1102		return NULL;
1103
1104	p = strchr(compatible, ',');
1105	strlcpy(devname, p ? p + 1 : compatible, sizeof(devname));
1106	/* Search through the device name */
1107	while (id->name[0]) {
1108		if (strcmp(devname, id->name) == 0)
1109			return id;
1110		id++;
1111	}
1112	return NULL;
1113}
1114
1115/*
1116 * idt_get_fw_data() - get IDT i2c-device parameters from device tree
1117 * @pdev:	Pointer to the driver data
1118 */
1119static void idt_get_fw_data(struct idt_89hpesx_dev *pdev)
1120{
1121	struct device *dev = &pdev->client->dev;
1122	struct fwnode_handle *fwnode;
1123	const struct i2c_device_id *ee_id = NULL;
1124	u32 eeprom_addr;
1125	int ret;
1126
1127	device_for_each_child_node(dev, fwnode) {
1128		ee_id = idt_ee_match_id(fwnode);
1129		if (!ee_id) {
1130			dev_warn(dev, "Skip unsupported EEPROM device");
1131			continue;
1132		} else
1133			break;
1134	}
1135
1136	/* If there is no fwnode EEPROM device, then set zero size */
1137	if (!ee_id) {
1138		dev_warn(dev, "No fwnode, EEPROM access disabled");
1139		idt_set_defval(pdev);
1140		return;
1141	}
1142
1143	/* Retrieve EEPROM size */
1144	pdev->eesize = (u32)ee_id->driver_data;
1145
1146	/* Get custom EEPROM address from 'reg' attribute */
1147	ret = fwnode_property_read_u32(fwnode, "reg", &eeprom_addr);
1148	if (ret || (eeprom_addr == 0)) {
1149		dev_warn(dev, "No EEPROM reg found, use default address 0x%x",
1150			 EEPROM_DEF_ADDR);
1151		pdev->inieecmd = 0;
1152		pdev->eeaddr = EEPROM_DEF_ADDR << 1;
1153	} else {
1154		pdev->inieecmd = EEPROM_USA;
1155		pdev->eeaddr = eeprom_addr << 1;
1156	}
1157
1158	/* Check EEPROM 'read-only' flag */
1159	if (fwnode_property_read_bool(fwnode, "read-only"))
1160		pdev->eero = true;
1161	else /* if (!fwnode_property_read_bool(node, "read-only")) */
1162		pdev->eero = false;
1163
1164	dev_info(dev, "EEPROM of %d bytes found by 0x%x",
1165		pdev->eesize, pdev->eeaddr);
1166}
1167
1168/*
1169 * idt_create_pdev() - create and init data structure of the driver
1170 * @client:	i2c client of IDT PCIe-switch device
1171 */
1172static struct idt_89hpesx_dev *idt_create_pdev(struct i2c_client *client)
1173{
1174	struct idt_89hpesx_dev *pdev;
1175
1176	/* Allocate memory for driver data */
1177	pdev = devm_kmalloc(&client->dev, sizeof(struct idt_89hpesx_dev),
1178		GFP_KERNEL);
1179	if (pdev == NULL)
1180		return ERR_PTR(-ENOMEM);
1181
1182	/* Initialize basic fields of the data */
1183	pdev->client = client;
1184	i2c_set_clientdata(client, pdev);
1185
1186	/* Read firmware nodes information */
1187	idt_get_fw_data(pdev);
1188
1189	/* Initialize basic CSR CMD field - use full DWORD-sized r/w ops */
1190	pdev->inicsrcmd = CSR_DWE;
1191	pdev->csr = CSR_DEF;
1192
1193	/* Enable Packet Error Checking if it's supported by adapter */
1194	if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_PEC)) {
1195		pdev->iniccode = CCODE_PEC;
1196		client->flags |= I2C_CLIENT_PEC;
1197	} else /* PEC is unsupported */ {
1198		pdev->iniccode = 0;
1199	}
1200
1201	return pdev;
1202}
1203
1204/*
1205 * idt_free_pdev() - free data structure of the driver
1206 * @pdev:	Pointer to the driver data
1207 */
1208static void idt_free_pdev(struct idt_89hpesx_dev *pdev)
1209{
1210	/* Clear driver data from device private field */
1211	i2c_set_clientdata(pdev->client, NULL);
1212}
1213
1214/*
1215 * idt_set_smbus_ops() - set supported SMBus operations
1216 * @pdev:	Pointer to the driver data
1217 * Return status of smbus check operations
1218 */
1219static int idt_set_smbus_ops(struct idt_89hpesx_dev *pdev)
1220{
1221	struct i2c_adapter *adapter = pdev->client->adapter;
1222	struct device *dev = &pdev->client->dev;
1223
1224	/* Check i2c adapter read functionality */
1225	if (i2c_check_functionality(adapter,
1226				    I2C_FUNC_SMBUS_READ_BLOCK_DATA)) {
1227		pdev->smb_read = idt_smb_read_block;
1228		dev_dbg(dev, "SMBus block-read op chosen");
1229	} else if (i2c_check_functionality(adapter,
1230					   I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
1231		pdev->smb_read = idt_smb_read_i2c_block;
1232		dev_dbg(dev, "SMBus i2c-block-read op chosen");
1233	} else if (i2c_check_functionality(adapter,
1234					   I2C_FUNC_SMBUS_READ_WORD_DATA) &&
1235		   i2c_check_functionality(adapter,
1236					   I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
1237		pdev->smb_read = idt_smb_read_word;
1238		dev_warn(dev, "Use slow word/byte SMBus read ops");
1239	} else if (i2c_check_functionality(adapter,
1240					   I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
1241		pdev->smb_read = idt_smb_read_byte;
1242		dev_warn(dev, "Use slow byte SMBus read op");
1243	} else /* no supported smbus read operations */ {
1244		dev_err(dev, "No supported SMBus read op");
1245		return -EPFNOSUPPORT;
1246	}
1247
1248	/* Check i2c adapter write functionality */
1249	if (i2c_check_functionality(adapter,
1250				    I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)) {
1251		pdev->smb_write = idt_smb_write_block;
1252		dev_dbg(dev, "SMBus block-write op chosen");
1253	} else if (i2c_check_functionality(adapter,
1254					   I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)) {
1255		pdev->smb_write = idt_smb_write_i2c_block;
1256		dev_dbg(dev, "SMBus i2c-block-write op chosen");
1257	} else if (i2c_check_functionality(adapter,
1258					   I2C_FUNC_SMBUS_WRITE_WORD_DATA) &&
1259		   i2c_check_functionality(adapter,
1260					   I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) {
1261		pdev->smb_write = idt_smb_write_word;
1262		dev_warn(dev, "Use slow word/byte SMBus write op");
1263	} else if (i2c_check_functionality(adapter,
1264					   I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) {
1265		pdev->smb_write = idt_smb_write_byte;
1266		dev_warn(dev, "Use slow byte SMBus write op");
1267	} else /* no supported smbus write operations */ {
1268		dev_err(dev, "No supported SMBus write op");
1269		return -EPFNOSUPPORT;
1270	}
1271
1272	/* Initialize IDT SMBus slave interface mutex */
1273	mutex_init(&pdev->smb_mtx);
1274
1275	return 0;
1276}
1277
1278/*
1279 * idt_check_dev() - check whether it's really IDT 89HPESx device
1280 * @pdev:	Pointer to the driver data
1281 * Return status of i2c adapter check operation
1282 */
1283static int idt_check_dev(struct idt_89hpesx_dev *pdev)
1284{
1285	struct device *dev = &pdev->client->dev;
1286	u32 viddid;
1287	int ret;
1288
1289	/* Read VID and DID directly from IDT memory space */
1290	ret = idt_csr_read(pdev, IDT_VIDDID_CSR, &viddid);
1291	if (ret != 0) {
1292		dev_err(dev, "Failed to read VID/DID");
1293		return ret;
1294	}
1295
1296	/* Check whether it's IDT device */
1297	if ((viddid & IDT_VID_MASK) != PCI_VENDOR_ID_IDT) {
1298		dev_err(dev, "Got unsupported VID/DID: 0x%08x", viddid);
1299		return -ENODEV;
1300	}
1301
1302	dev_info(dev, "Found IDT 89HPES device VID:0x%04x, DID:0x%04x",
1303		(viddid & IDT_VID_MASK), (viddid >> 16));
1304
1305	return 0;
1306}
1307
1308/*
1309 * idt_create_sysfs_files() - create sysfs attribute files
1310 * @pdev:	Pointer to the driver data
1311 * Return status of operation
1312 */
1313static int idt_create_sysfs_files(struct idt_89hpesx_dev *pdev)
1314{
1315	struct device *dev = &pdev->client->dev;
1316	int ret;
1317
1318	/* Don't do anything if EEPROM isn't accessible */
1319	if (pdev->eesize == 0) {
1320		dev_dbg(dev, "Skip creating sysfs-files");
1321		return 0;
1322	}
1323
1324	/* Allocate memory for attribute file */
1325	pdev->ee_file = devm_kmalloc(dev, sizeof(*pdev->ee_file), GFP_KERNEL);
1326	if (!pdev->ee_file)
1327		return -ENOMEM;
1328
1329	/* Copy the declared EEPROM attr structure to change some of fields */
1330	memcpy(pdev->ee_file, &bin_attr_eeprom, sizeof(*pdev->ee_file));
1331
1332	/* In case of read-only EEPROM get rid of write ability */
1333	if (pdev->eero) {
1334		pdev->ee_file->attr.mode &= ~0200;
1335		pdev->ee_file->write = NULL;
1336	}
1337	/* Create EEPROM sysfs file */
1338	pdev->ee_file->size = pdev->eesize;
1339	ret = sysfs_create_bin_file(&dev->kobj, pdev->ee_file);
1340	if (ret != 0) {
1341		dev_err(dev, "Failed to create EEPROM sysfs-node");
1342		return ret;
1343	}
1344
1345	return 0;
1346}
1347
1348/*
1349 * idt_remove_sysfs_files() - remove sysfs attribute files
1350 * @pdev:	Pointer to the driver data
1351 */
1352static void idt_remove_sysfs_files(struct idt_89hpesx_dev *pdev)
1353{
1354	struct device *dev = &pdev->client->dev;
1355
1356	/* Don't do anything if EEPROM wasn't accessible */
1357	if (pdev->eesize == 0)
1358		return;
1359
1360	/* Remove EEPROM sysfs file */
1361	sysfs_remove_bin_file(&dev->kobj, pdev->ee_file);
1362}
1363
1364/*
1365 * idt_create_dbgfs_files() - create debugfs files
1366 * @pdev:	Pointer to the driver data
1367 */
1368#define CSRNAME_LEN	((size_t)32)
1369static void idt_create_dbgfs_files(struct idt_89hpesx_dev *pdev)
1370{
1371	struct i2c_client *cli = pdev->client;
1372	char fname[CSRNAME_LEN];
1373
1374	/* Create Debugfs directory for CSR file */
1375	snprintf(fname, CSRNAME_LEN, "%d-%04hx", cli->adapter->nr, cli->addr);
1376	pdev->csr_dir = debugfs_create_dir(fname, csr_dbgdir);
1377
1378	/* Create Debugfs file for CSR read/write operations */
1379	debugfs_create_file(cli->name, 0600, pdev->csr_dir, pdev,
1380			    &csr_dbgfs_ops);
1381}
1382
1383/*
1384 * idt_remove_dbgfs_files() - remove debugfs files
1385 * @pdev:	Pointer to the driver data
1386 */
1387static void idt_remove_dbgfs_files(struct idt_89hpesx_dev *pdev)
1388{
1389	/* Remove CSR directory and it sysfs-node */
1390	debugfs_remove_recursive(pdev->csr_dir);
1391}
1392
1393/*
1394 * idt_probe() - IDT 89HPESx driver probe() callback method
1395 */
1396static int idt_probe(struct i2c_client *client, const struct i2c_device_id *id)
1397{
1398	struct idt_89hpesx_dev *pdev;
1399	int ret;
1400
1401	/* Create driver data */
1402	pdev = idt_create_pdev(client);
1403	if (IS_ERR(pdev))
1404		return PTR_ERR(pdev);
1405
1406	/* Set SMBus operations */
1407	ret = idt_set_smbus_ops(pdev);
1408	if (ret != 0)
1409		goto err_free_pdev;
1410
1411	/* Check whether it is truly IDT 89HPESx device */
1412	ret = idt_check_dev(pdev);
1413	if (ret != 0)
1414		goto err_free_pdev;
1415
1416	/* Create sysfs files */
1417	ret = idt_create_sysfs_files(pdev);
1418	if (ret != 0)
1419		goto err_free_pdev;
1420
1421	/* Create debugfs files */
1422	idt_create_dbgfs_files(pdev);
1423
1424	return 0;
1425
1426err_free_pdev:
1427	idt_free_pdev(pdev);
1428
1429	return ret;
1430}
1431
1432/*
1433 * idt_remove() - IDT 89HPESx driver remove() callback method
1434 */
1435static int idt_remove(struct i2c_client *client)
1436{
1437	struct idt_89hpesx_dev *pdev = i2c_get_clientdata(client);
1438
1439	/* Remove debugfs files first */
1440	idt_remove_dbgfs_files(pdev);
1441
1442	/* Remove sysfs files */
1443	idt_remove_sysfs_files(pdev);
1444
1445	/* Discard driver data structure */
1446	idt_free_pdev(pdev);
1447
1448	return 0;
1449}
1450
1451/*
1452 * ee_ids - array of supported EEPROMs
1453 */
1454static const struct i2c_device_id ee_ids[] = {
1455	{ "24c32",  4096},
1456	{ "24c64",  8192},
1457	{ "24c128", 16384},
1458	{ "24c256", 32768},
1459	{ "24c512", 65536},
1460	{}
1461};
1462MODULE_DEVICE_TABLE(i2c, ee_ids);
1463
1464/*
1465 * idt_ids - supported IDT 89HPESx devices
1466 */
1467static const struct i2c_device_id idt_ids[] = {
1468	{ "89hpes8nt2", 0 },
1469	{ "89hpes12nt3", 0 },
1470
1471	{ "89hpes24nt6ag2", 0 },
1472	{ "89hpes32nt8ag2", 0 },
1473	{ "89hpes32nt8bg2", 0 },
1474	{ "89hpes12nt12g2", 0 },
1475	{ "89hpes16nt16g2", 0 },
1476	{ "89hpes24nt24g2", 0 },
1477	{ "89hpes32nt24ag2", 0 },
1478	{ "89hpes32nt24bg2", 0 },
1479
1480	{ "89hpes12n3", 0 },
1481	{ "89hpes12n3a", 0 },
1482	{ "89hpes24n3", 0 },
1483	{ "89hpes24n3a", 0 },
1484
1485	{ "89hpes32h8", 0 },
1486	{ "89hpes32h8g2", 0 },
1487	{ "89hpes48h12", 0 },
1488	{ "89hpes48h12g2", 0 },
1489	{ "89hpes48h12ag2", 0 },
1490	{ "89hpes16h16", 0 },
1491	{ "89hpes22h16", 0 },
1492	{ "89hpes22h16g2", 0 },
1493	{ "89hpes34h16", 0 },
1494	{ "89hpes34h16g2", 0 },
1495	{ "89hpes64h16", 0 },
1496	{ "89hpes64h16g2", 0 },
1497	{ "89hpes64h16ag2", 0 },
1498
1499	/* { "89hpes3t3", 0 }, // No SMBus-slave iface */
1500	{ "89hpes12t3g2", 0 },
1501	{ "89hpes24t3g2", 0 },
1502	/* { "89hpes4t4", 0 }, // No SMBus-slave iface */
1503	{ "89hpes16t4", 0 },
1504	{ "89hpes4t4g2", 0 },
1505	{ "89hpes10t4g2", 0 },
1506	{ "89hpes16t4g2", 0 },
1507	{ "89hpes16t4ag2", 0 },
1508	{ "89hpes5t5", 0 },
1509	{ "89hpes6t5", 0 },
1510	{ "89hpes8t5", 0 },
1511	{ "89hpes8t5a", 0 },
1512	{ "89hpes24t6", 0 },
1513	{ "89hpes6t6g2", 0 },
1514	{ "89hpes24t6g2", 0 },
1515	{ "89hpes16t7", 0 },
1516	{ "89hpes32t8", 0 },
1517	{ "89hpes32t8g2", 0 },
1518	{ "89hpes48t12", 0 },
1519	{ "89hpes48t12g2", 0 },
1520	{ /* END OF LIST */ }
1521};
1522MODULE_DEVICE_TABLE(i2c, idt_ids);
1523
1524static const struct of_device_id idt_of_match[] = {
1525	{ .compatible = "idt,89hpes8nt2", },
1526	{ .compatible = "idt,89hpes12nt3", },
1527
1528	{ .compatible = "idt,89hpes24nt6ag2", },
1529	{ .compatible = "idt,89hpes32nt8ag2", },
1530	{ .compatible = "idt,89hpes32nt8bg2", },
1531	{ .compatible = "idt,89hpes12nt12g2", },
1532	{ .compatible = "idt,89hpes16nt16g2", },
1533	{ .compatible = "idt,89hpes24nt24g2", },
1534	{ .compatible = "idt,89hpes32nt24ag2", },
1535	{ .compatible = "idt,89hpes32nt24bg2", },
1536
1537	{ .compatible = "idt,89hpes12n3", },
1538	{ .compatible = "idt,89hpes12n3a", },
1539	{ .compatible = "idt,89hpes24n3", },
1540	{ .compatible = "idt,89hpes24n3a", },
1541
1542	{ .compatible = "idt,89hpes32h8", },
1543	{ .compatible = "idt,89hpes32h8g2", },
1544	{ .compatible = "idt,89hpes48h12", },
1545	{ .compatible = "idt,89hpes48h12g2", },
1546	{ .compatible = "idt,89hpes48h12ag2", },
1547	{ .compatible = "idt,89hpes16h16", },
1548	{ .compatible = "idt,89hpes22h16", },
1549	{ .compatible = "idt,89hpes22h16g2", },
1550	{ .compatible = "idt,89hpes34h16", },
1551	{ .compatible = "idt,89hpes34h16g2", },
1552	{ .compatible = "idt,89hpes64h16", },
1553	{ .compatible = "idt,89hpes64h16g2", },
1554	{ .compatible = "idt,89hpes64h16ag2", },
1555
1556	{ .compatible = "idt,89hpes12t3g2", },
1557	{ .compatible = "idt,89hpes24t3g2", },
1558
1559	{ .compatible = "idt,89hpes16t4", },
1560	{ .compatible = "idt,89hpes4t4g2", },
1561	{ .compatible = "idt,89hpes10t4g2", },
1562	{ .compatible = "idt,89hpes16t4g2", },
1563	{ .compatible = "idt,89hpes16t4ag2", },
1564	{ .compatible = "idt,89hpes5t5", },
1565	{ .compatible = "idt,89hpes6t5", },
1566	{ .compatible = "idt,89hpes8t5", },
1567	{ .compatible = "idt,89hpes8t5a", },
1568	{ .compatible = "idt,89hpes24t6", },
1569	{ .compatible = "idt,89hpes6t6g2", },
1570	{ .compatible = "idt,89hpes24t6g2", },
1571	{ .compatible = "idt,89hpes16t7", },
1572	{ .compatible = "idt,89hpes32t8", },
1573	{ .compatible = "idt,89hpes32t8g2", },
1574	{ .compatible = "idt,89hpes48t12", },
1575	{ .compatible = "idt,89hpes48t12g2", },
1576	{ },
1577};
1578MODULE_DEVICE_TABLE(of, idt_of_match);
1579
1580/*
1581 * idt_driver - IDT 89HPESx driver structure
1582 */
1583static struct i2c_driver idt_driver = {
1584	.driver = {
1585		.name = IDT_NAME,
1586		.of_match_table = idt_of_match,
1587	},
1588	.probe = idt_probe,
1589	.remove = idt_remove,
1590	.id_table = idt_ids,
1591};
1592
1593/*
1594 * idt_init() - IDT 89HPESx driver init() callback method
1595 */
1596static int __init idt_init(void)
1597{
1598	/* Create Debugfs directory first */
1599	if (debugfs_initialized())
1600		csr_dbgdir = debugfs_create_dir("idt_csr", NULL);
1601
1602	/* Add new i2c-device driver */
1603	return i2c_add_driver(&idt_driver);
1604}
1605module_init(idt_init);
1606
1607/*
1608 * idt_exit() - IDT 89HPESx driver exit() callback method
1609 */
1610static void __exit idt_exit(void)
1611{
1612	/* Discard debugfs directory and all files if any */
1613	debugfs_remove_recursive(csr_dbgdir);
1614
1615	/* Unregister i2c-device driver */
1616	i2c_del_driver(&idt_driver);
1617}
1618module_exit(idt_exit);