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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *   Copyright (C) 2016 T-Platforms. All Rights Reserved.
   4 *
   5 * IDT PCIe-switch NTB Linux driver
   6 *
   7 * Contact Information:
   8 * Serge Semin <fancer.lancer@gmail.com>, <Sergey.Semin@t-platforms.ru>
   9 */
  10/*
  11 *           NOTE of the IDT 89HPESx SMBus-slave interface driver
  12 *    This driver primarily is developed to have an access to EEPROM device of
  13 * IDT PCIe-switches. IDT provides a simple SMBus interface to perform IO-
  14 * operations from/to EEPROM, which is located at private (so called Master)
  15 * SMBus of switches. Using that interface this the driver creates a simple
  16 * binary sysfs-file in the device directory:
  17 * /sys/bus/i2c/devices/<bus>-<devaddr>/eeprom
  18 * In case if read-only flag is specified in the dts-node of device desription,
  19 * User-space applications won't be able to write to the EEPROM sysfs-node.
  20 *    Additionally IDT 89HPESx SMBus interface has an ability to write/read
  21 * data of device CSRs. This driver exposes debugf-file to perform simple IO
  22 * operations using that ability for just basic debug purpose. Particularly
  23 * next file is created in the specific debugfs-directory:
  24 * /sys/kernel/debug/idt_csr/
  25 * Format of the debugfs-node is:
  26 * $ cat /sys/kernel/debug/idt_csr/<bus>-<devaddr>/<devname>;
  27 * <CSR address>:<CSR value>
  28 * So reading the content of the file gives current CSR address and it value.
  29 * If User-space application wishes to change current CSR address,
  30 * it can just write a proper value to the sysfs-file:
  31 * $ echo "<CSR address>" > /sys/kernel/debug/idt_csr/<bus>-<devaddr>/<devname>
  32 * If it wants to change the CSR value as well, the format of the write
  33 * operation is:
  34 * $ echo "<CSR address>:<CSR value>" > \
  35 *        /sys/kernel/debug/idt_csr/<bus>-<devaddr>/<devname>;
  36 * CSR address and value can be any of hexadecimal, decimal or octal format.
  37 */
  38
  39#include <linux/kernel.h>
  40#include <linux/init.h>
  41#include <linux/module.h>
  42#include <linux/types.h>
  43#include <linux/sizes.h>
  44#include <linux/slab.h>
  45#include <linux/mutex.h>
  46#include <linux/sysfs.h>
  47#include <linux/debugfs.h>
  48#include <linux/mod_devicetable.h>
  49#include <linux/property.h>
  50#include <linux/i2c.h>
  51#include <linux/pci_ids.h>
  52#include <linux/delay.h>
  53
  54#define IDT_NAME		"89hpesx"
  55#define IDT_89HPESX_DESC	"IDT 89HPESx SMBus-slave interface driver"
  56#define IDT_89HPESX_VER		"1.0"
  57
  58MODULE_DESCRIPTION(IDT_89HPESX_DESC);
  59MODULE_VERSION(IDT_89HPESX_VER);
  60MODULE_LICENSE("GPL v2");
  61MODULE_AUTHOR("T-platforms");
  62
  63/*
  64 * csr_dbgdir - CSR read/write operations Debugfs directory
  65 */
  66static struct dentry *csr_dbgdir;
  67
  68/*
  69 * struct idt_89hpesx_dev - IDT 89HPESx device data structure
  70 * @eesize:	Size of EEPROM in bytes (calculated from "idt,eecompatible")
  71 * @eero:	EEPROM Read-only flag
  72 * @eeaddr:	EEPROM custom address
  73 *
  74 * @inieecmd:	Initial cmd value for EEPROM read/write operations
  75 * @inicsrcmd:	Initial cmd value for CSR read/write operations
  76 * @iniccode:	Initialial command code value for IO-operations
  77 *
  78 * @csr:	CSR address to perform read operation
  79 *
  80 * @smb_write:	SMBus write method
  81 * @smb_read:	SMBus read method
  82 * @smb_mtx:	SMBus mutex
  83 *
  84 * @client:	i2c client used to perform IO operations
  85 *
  86 * @ee_file:	EEPROM read/write sysfs-file
  87 */
  88struct idt_smb_seq;
  89struct idt_89hpesx_dev {
  90	u32 eesize;
  91	bool eero;
  92	u8 eeaddr;
  93
  94	u8 inieecmd;
  95	u8 inicsrcmd;
  96	u8 iniccode;
  97
  98	u16 csr;
  99
 100	int (*smb_write)(struct idt_89hpesx_dev *, const struct idt_smb_seq *);
 101	int (*smb_read)(struct idt_89hpesx_dev *, struct idt_smb_seq *);
 102	struct mutex smb_mtx;
 103
 104	struct i2c_client *client;
 105
 106	struct bin_attribute *ee_file;
 107	struct dentry *csr_dir;
 108};
 109
 110/*
 111 * struct idt_smb_seq - sequence of data to be read/written from/to IDT 89HPESx
 112 * @ccode:	SMBus command code
 113 * @bytecnt:	Byte count of operation
 114 * @data:	Data to by written
 115 */
 116struct idt_smb_seq {
 117	u8 ccode;
 118	u8 bytecnt;
 119	u8 *data;
 120};
 121
 122/*
 123 * struct idt_eeprom_seq - sequence of data to be read/written from/to EEPROM
 124 * @cmd:	Transaction CMD
 125 * @eeaddr:	EEPROM custom address
 126 * @memaddr:	Internal memory address of EEPROM
 127 * @data:	Data to be written at the memory address
 128 */
 129struct idt_eeprom_seq {
 130	u8 cmd;
 131	u8 eeaddr;
 132	u16 memaddr;
 133	u8 data;
 134} __packed;
 135
 136/*
 137 * struct idt_csr_seq - sequence of data to be read/written from/to CSR
 138 * @cmd:	Transaction CMD
 139 * @csraddr:	Internal IDT device CSR address
 140 * @data:	Data to be read/written from/to the CSR address
 141 */
 142struct idt_csr_seq {
 143	u8 cmd;
 144	u16 csraddr;
 145	u32 data;
 146} __packed;
 147
 148/*
 149 * SMBus command code macros
 150 * @CCODE_END:		Indicates the end of transaction
 151 * @CCODE_START:	Indicates the start of transaction
 152 * @CCODE_CSR:		CSR read/write transaction
 153 * @CCODE_EEPROM:	EEPROM read/write transaction
 154 * @CCODE_BYTE:		Supplied data has BYTE length
 155 * @CCODE_WORD:		Supplied data has WORD length
 156 * @CCODE_BLOCK:	Supplied data has variable length passed in bytecnt
 157 *			byte right following CCODE byte
 158 */
 159#define CCODE_END	((u8)0x01)
 160#define CCODE_START	((u8)0x02)
 161#define CCODE_CSR	((u8)0x00)
 162#define CCODE_EEPROM	((u8)0x04)
 163#define CCODE_BYTE	((u8)0x00)
 164#define CCODE_WORD	((u8)0x20)
 165#define CCODE_BLOCK	((u8)0x40)
 166#define CCODE_PEC	((u8)0x80)
 167
 168/*
 169 * EEPROM command macros
 170 * @EEPROM_OP_WRITE:	EEPROM write operation
 171 * @EEPROM_OP_READ:	EEPROM read operation
 172 * @EEPROM_USA:		Use specified address of EEPROM
 173 * @EEPROM_NAERR:	EEPROM device is not ready to respond
 174 * @EEPROM_LAERR:	EEPROM arbitration loss error
 175 * @EEPROM_MSS:		EEPROM misplace start & stop bits error
 176 * @EEPROM_WR_CNT:	Bytes count to perform write operation
 177 * @EEPROM_WRRD_CNT:	Bytes count to write before reading
 178 * @EEPROM_RD_CNT:	Bytes count to perform read operation
 179 * @EEPROM_DEF_SIZE:	Fall back size of EEPROM
 180 * @EEPROM_DEF_ADDR:	Defatul EEPROM address
 181 * @EEPROM_TOUT:	Timeout before retry read operation if eeprom is busy
 182 */
 183#define EEPROM_OP_WRITE	((u8)0x00)
 184#define EEPROM_OP_READ	((u8)0x01)
 185#define EEPROM_USA	((u8)0x02)
 186#define EEPROM_NAERR	((u8)0x08)
 187#define EEPROM_LAERR    ((u8)0x10)
 188#define EEPROM_MSS	((u8)0x20)
 189#define EEPROM_WR_CNT	((u8)5)
 190#define EEPROM_WRRD_CNT	((u8)4)
 191#define EEPROM_RD_CNT	((u8)5)
 192#define EEPROM_DEF_SIZE	((u16)4096)
 193#define EEPROM_DEF_ADDR	((u8)0x50)
 194#define EEPROM_TOUT	(100)
 195
 196/*
 197 * CSR command macros
 198 * @CSR_DWE:		Enable all four bytes of the operation
 199 * @CSR_OP_WRITE:	CSR write operation
 200 * @CSR_OP_READ:	CSR read operation
 201 * @CSR_RERR:		Read operation error
 202 * @CSR_WERR:		Write operation error
 203 * @CSR_WR_CNT:		Bytes count to perform write operation
 204 * @CSR_WRRD_CNT:	Bytes count to write before reading
 205 * @CSR_RD_CNT:		Bytes count to perform read operation
 206 * @CSR_MAX:		Maximum CSR address
 207 * @CSR_DEF:		Default CSR address
 208 * @CSR_REAL_ADDR:	CSR real unshifted address
 209 */
 210#define CSR_DWE			((u8)0x0F)
 211#define CSR_OP_WRITE		((u8)0x00)
 212#define CSR_OP_READ		((u8)0x10)
 213#define CSR_RERR		((u8)0x40)
 214#define CSR_WERR		((u8)0x80)
 215#define CSR_WR_CNT		((u8)7)
 216#define CSR_WRRD_CNT		((u8)3)
 217#define CSR_RD_CNT		((u8)7)
 218#define CSR_MAX			((u32)0x3FFFF)
 219#define CSR_DEF			((u16)0x0000)
 220#define CSR_REAL_ADDR(val)	((unsigned int)val << 2)
 221
 222/*
 223 * IDT 89HPESx basic register
 224 * @IDT_VIDDID_CSR:	PCIe VID and DID of IDT 89HPESx
 225 * @IDT_VID_MASK:	Mask of VID
 226 */
 227#define IDT_VIDDID_CSR	((u32)0x0000)
 228#define IDT_VID_MASK	((u32)0xFFFF)
 229
 230/*
 231 * IDT 89HPESx can send NACK when new command is sent before previous one
 232 * fininshed execution. In this case driver retries operation
 233 * certain times.
 234 * @RETRY_CNT:		Number of retries before giving up and fail
 235 * @idt_smb_safe:	Generate a retry loop on corresponding SMBus method
 236 */
 237#define RETRY_CNT (128)
 238#define idt_smb_safe(ops, args...) ({ \
 239	int __retry = RETRY_CNT; \
 240	s32 __sts; \
 241	do { \
 242		__sts = i2c_smbus_ ## ops ## _data(args); \
 243	} while (__retry-- && __sts < 0); \
 244	__sts; \
 245})
 246
 247/*===========================================================================
 248 *                         i2c bus level IO-operations
 249 *===========================================================================
 250 */
 251
 252/*
 253 * idt_smb_write_byte() - SMBus write method when I2C_SMBUS_BYTE_DATA operation
 254 *                        is only available
 255 * @pdev:	Pointer to the driver data
 256 * @seq:	Sequence of data to be written
 257 */
 258static int idt_smb_write_byte(struct idt_89hpesx_dev *pdev,
 259			      const struct idt_smb_seq *seq)
 260{
 261	s32 sts;
 262	u8 ccode;
 263	int idx;
 264
 265	/* Loop over the supplied data sending byte one-by-one */
 266	for (idx = 0; idx < seq->bytecnt; idx++) {
 267		/* Collect the command code byte */
 268		ccode = seq->ccode | CCODE_BYTE;
 269		if (idx == 0)
 270			ccode |= CCODE_START;
 271		if (idx == seq->bytecnt - 1)
 272			ccode |= CCODE_END;
 273
 274		/* Send data to the device */
 275		sts = idt_smb_safe(write_byte, pdev->client, ccode,
 276			seq->data[idx]);
 277		if (sts != 0)
 278			return (int)sts;
 279	}
 280
 281	return 0;
 282}
 283
 284/*
 285 * idt_smb_read_byte() - SMBus read method when I2C_SMBUS_BYTE_DATA operation
 286 *                        is only available
 287 * @pdev:	Pointer to the driver data
 288 * @seq:	Buffer to read data to
 289 */
 290static int idt_smb_read_byte(struct idt_89hpesx_dev *pdev,
 291			     struct idt_smb_seq *seq)
 292{
 293	s32 sts;
 294	u8 ccode;
 295	int idx;
 296
 297	/* Loop over the supplied buffer receiving byte one-by-one */
 298	for (idx = 0; idx < seq->bytecnt; idx++) {
 299		/* Collect the command code byte */
 300		ccode = seq->ccode | CCODE_BYTE;
 301		if (idx == 0)
 302			ccode |= CCODE_START;
 303		if (idx == seq->bytecnt - 1)
 304			ccode |= CCODE_END;
 305
 306		/* Read data from the device */
 307		sts = idt_smb_safe(read_byte, pdev->client, ccode);
 308		if (sts < 0)
 309			return (int)sts;
 310
 311		seq->data[idx] = (u8)sts;
 312	}
 313
 314	return 0;
 315}
 316
 317/*
 318 * idt_smb_write_word() - SMBus write method when I2C_SMBUS_BYTE_DATA and
 319 *                        I2C_FUNC_SMBUS_WORD_DATA operations are available
 320 * @pdev:	Pointer to the driver data
 321 * @seq:	Sequence of data to be written
 322 */
 323static int idt_smb_write_word(struct idt_89hpesx_dev *pdev,
 324			      const struct idt_smb_seq *seq)
 325{
 326	s32 sts;
 327	u8 ccode;
 328	int idx, evencnt;
 329
 330	/* Calculate the even count of data to send */
 331	evencnt = seq->bytecnt - (seq->bytecnt % 2);
 332
 333	/* Loop over the supplied data sending two bytes at a time */
 334	for (idx = 0; idx < evencnt; idx += 2) {
 335		/* Collect the command code byte */
 336		ccode = seq->ccode | CCODE_WORD;
 337		if (idx == 0)
 338			ccode |= CCODE_START;
 339		if (idx == evencnt - 2)
 340			ccode |= CCODE_END;
 341
 342		/* Send word data to the device */
 343		sts = idt_smb_safe(write_word, pdev->client, ccode,
 344			*(u16 *)&seq->data[idx]);
 345		if (sts != 0)
 346			return (int)sts;
 347	}
 348
 349	/* If there is odd number of bytes then send just one last byte */
 350	if (seq->bytecnt != evencnt) {
 351		/* Collect the command code byte */
 352		ccode = seq->ccode | CCODE_BYTE | CCODE_END;
 353		if (idx == 0)
 354			ccode |= CCODE_START;
 355
 356		/* Send byte data to the device */
 357		sts = idt_smb_safe(write_byte, pdev->client, ccode,
 358			seq->data[idx]);
 359		if (sts != 0)
 360			return (int)sts;
 361	}
 362
 363	return 0;
 364}
 365
 366/*
 367 * idt_smb_read_word() - SMBus read method when I2C_SMBUS_BYTE_DATA and
 368 *                       I2C_FUNC_SMBUS_WORD_DATA operations are available
 369 * @pdev:	Pointer to the driver data
 370 * @seq:	Buffer to read data to
 371 */
 372static int idt_smb_read_word(struct idt_89hpesx_dev *pdev,
 373			     struct idt_smb_seq *seq)
 374{
 375	s32 sts;
 376	u8 ccode;
 377	int idx, evencnt;
 378
 379	/* Calculate the even count of data to send */
 380	evencnt = seq->bytecnt - (seq->bytecnt % 2);
 381
 382	/* Loop over the supplied data reading two bytes at a time */
 383	for (idx = 0; idx < evencnt; idx += 2) {
 384		/* Collect the command code byte */
 385		ccode = seq->ccode | CCODE_WORD;
 386		if (idx == 0)
 387			ccode |= CCODE_START;
 388		if (idx == evencnt - 2)
 389			ccode |= CCODE_END;
 390
 391		/* Read word data from the device */
 392		sts = idt_smb_safe(read_word, pdev->client, ccode);
 393		if (sts < 0)
 394			return (int)sts;
 395
 396		*(u16 *)&seq->data[idx] = (u16)sts;
 397	}
 398
 399	/* If there is odd number of bytes then receive just one last byte */
 400	if (seq->bytecnt != evencnt) {
 401		/* Collect the command code byte */
 402		ccode = seq->ccode | CCODE_BYTE | CCODE_END;
 403		if (idx == 0)
 404			ccode |= CCODE_START;
 405
 406		/* Read last data byte from the device */
 407		sts = idt_smb_safe(read_byte, pdev->client, ccode);
 408		if (sts < 0)
 409			return (int)sts;
 410
 411		seq->data[idx] = (u8)sts;
 412	}
 413
 414	return 0;
 415}
 416
 417/*
 418 * idt_smb_write_block() - SMBus write method when I2C_SMBUS_BLOCK_DATA
 419 *                         operation is available
 420 * @pdev:	Pointer to the driver data
 421 * @seq:	Sequence of data to be written
 422 */
 423static int idt_smb_write_block(struct idt_89hpesx_dev *pdev,
 424			       const struct idt_smb_seq *seq)
 425{
 426	u8 ccode;
 427
 428	/* Return error if too much data passed to send */
 429	if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX)
 430		return -EINVAL;
 431
 432	/* Collect the command code byte */
 433	ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END;
 434
 435	/* Send block of data to the device */
 436	return idt_smb_safe(write_block, pdev->client, ccode, seq->bytecnt,
 437		seq->data);
 438}
 439
 440/*
 441 * idt_smb_read_block() - SMBus read method when I2C_SMBUS_BLOCK_DATA
 442 *                        operation is available
 443 * @pdev:	Pointer to the driver data
 444 * @seq:	Buffer to read data to
 445 */
 446static int idt_smb_read_block(struct idt_89hpesx_dev *pdev,
 447			      struct idt_smb_seq *seq)
 448{
 449	s32 sts;
 450	u8 ccode;
 451
 452	/* Return error if too much data passed to send */
 453	if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX)
 454		return -EINVAL;
 455
 456	/* Collect the command code byte */
 457	ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END;
 458
 459	/* Read block of data from the device */
 460	sts = idt_smb_safe(read_block, pdev->client, ccode, seq->data);
 461	if (sts != seq->bytecnt)
 462		return (sts < 0 ? sts : -ENODATA);
 463
 464	return 0;
 465}
 466
 467/*
 468 * idt_smb_write_i2c_block() - SMBus write method when I2C_SMBUS_I2C_BLOCK_DATA
 469 *                             operation is available
 470 * @pdev:	Pointer to the driver data
 471 * @seq:	Sequence of data to be written
 472 *
 473 * NOTE It's usual SMBus write block operation, except the actual data length is
 474 * sent as first byte of data
 475 */
 476static int idt_smb_write_i2c_block(struct idt_89hpesx_dev *pdev,
 477				   const struct idt_smb_seq *seq)
 478{
 479	u8 ccode, buf[I2C_SMBUS_BLOCK_MAX + 1];
 480
 481	/* Return error if too much data passed to send */
 482	if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX)
 483		return -EINVAL;
 484
 485	/* Collect the data to send. Length byte must be added prior the data */
 486	buf[0] = seq->bytecnt;
 487	memcpy(&buf[1], seq->data, seq->bytecnt);
 488
 489	/* Collect the command code byte */
 490	ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END;
 491
 492	/* Send length and block of data to the device */
 493	return idt_smb_safe(write_i2c_block, pdev->client, ccode,
 494		seq->bytecnt + 1, buf);
 495}
 496
 497/*
 498 * idt_smb_read_i2c_block() - SMBus read method when I2C_SMBUS_I2C_BLOCK_DATA
 499 *                            operation is available
 500 * @pdev:	Pointer to the driver data
 501 * @seq:	Buffer to read data to
 502 *
 503 * NOTE It's usual SMBus read block operation, except the actual data length is
 504 * retrieved as first byte of data
 505 */
 506static int idt_smb_read_i2c_block(struct idt_89hpesx_dev *pdev,
 507				  struct idt_smb_seq *seq)
 508{
 509	u8 ccode, buf[I2C_SMBUS_BLOCK_MAX + 1];
 510	s32 sts;
 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 command code byte */
 517	ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END;
 518
 519	/* Read length and block of data from the device */
 520	sts = idt_smb_safe(read_i2c_block, pdev->client, ccode,
 521		seq->bytecnt + 1, buf);
 522	if (sts != seq->bytecnt + 1)
 523		return (sts < 0 ? sts : -ENODATA);
 524	if (buf[0] != seq->bytecnt)
 525		return -ENODATA;
 526
 527	/* Copy retrieved data to the output data buffer */
 528	memcpy(seq->data, &buf[1], seq->bytecnt);
 529
 530	return 0;
 531}
 532
 533/*===========================================================================
 534 *                          EEPROM IO-operations
 535 *===========================================================================
 536 */
 537
 538/*
 539 * idt_eeprom_read_byte() - read just one byte from EEPROM
 540 * @pdev:	Pointer to the driver data
 541 * @memaddr:	Start EEPROM memory address
 542 * @data:	Data to be written to EEPROM
 543 */
 544static int idt_eeprom_read_byte(struct idt_89hpesx_dev *pdev, u16 memaddr,
 545				u8 *data)
 546{
 547	struct device *dev = &pdev->client->dev;
 548	struct idt_eeprom_seq eeseq;
 549	struct idt_smb_seq smbseq;
 550	int ret, retry;
 551
 552	/* Initialize SMBus sequence fields */
 553	smbseq.ccode = pdev->iniccode | CCODE_EEPROM;
 554	smbseq.data = (u8 *)&eeseq;
 555
 556	/*
 557	 * Sometimes EEPROM may respond with NACK if it's busy with previous
 558	 * operation, so we need to perform a few attempts of read cycle
 559	 */
 560	retry = RETRY_CNT;
 561	do {
 562		/* Send EEPROM memory address to read data from */
 563		smbseq.bytecnt = EEPROM_WRRD_CNT;
 564		eeseq.cmd = pdev->inieecmd | EEPROM_OP_READ;
 565		eeseq.eeaddr = pdev->eeaddr;
 566		eeseq.memaddr = cpu_to_le16(memaddr);
 567		ret = pdev->smb_write(pdev, &smbseq);
 568		if (ret != 0) {
 569			dev_err(dev, "Failed to init eeprom addr 0x%02x",
 570				memaddr);
 571			break;
 572		}
 573
 574		/* Perform read operation */
 575		smbseq.bytecnt = EEPROM_RD_CNT;
 576		ret = pdev->smb_read(pdev, &smbseq);
 577		if (ret != 0) {
 578			dev_err(dev, "Failed to read eeprom data 0x%02x",
 579				memaddr);
 580			break;
 581		}
 582
 583		/* Restart read operation if the device is busy */
 584		if (retry && (eeseq.cmd & EEPROM_NAERR)) {
 585			dev_dbg(dev, "EEPROM busy, retry reading after %d ms",
 586				EEPROM_TOUT);
 587			msleep(EEPROM_TOUT);
 588			continue;
 589		}
 590
 591		/* Check whether IDT successfully read data from EEPROM */
 592		if (eeseq.cmd & (EEPROM_NAERR | EEPROM_LAERR | EEPROM_MSS)) {
 593			dev_err(dev,
 594				"Communication with eeprom failed, cmd 0x%hhx",
 595				eeseq.cmd);
 596			ret = -EREMOTEIO;
 597			break;
 598		}
 599
 600		/* Save retrieved data and exit the loop */
 601		*data = eeseq.data;
 602		break;
 603	} while (retry--);
 604
 605	/* Return the status of operation */
 606	return ret;
 607}
 608
 609/*
 610 * idt_eeprom_write() - EEPROM write operation
 611 * @pdev:	Pointer to the driver data
 612 * @memaddr:	Start EEPROM memory address
 613 * @len:	Length of data to be written
 614 * @data:	Data to be written to EEPROM
 615 */
 616static int idt_eeprom_write(struct idt_89hpesx_dev *pdev, u16 memaddr, u16 len,
 617			    const u8 *data)
 618{
 619	struct device *dev = &pdev->client->dev;
 620	struct idt_eeprom_seq eeseq;
 621	struct idt_smb_seq smbseq;
 622	int ret;
 623	u16 idx;
 624
 625	/* Initialize SMBus sequence fields */
 626	smbseq.ccode = pdev->iniccode | CCODE_EEPROM;
 627	smbseq.data = (u8 *)&eeseq;
 628
 629	/* Send data byte-by-byte, checking if it is successfully written */
 630	for (idx = 0; idx < len; idx++, memaddr++) {
 631		/* Lock IDT SMBus device */
 632		mutex_lock(&pdev->smb_mtx);
 633
 634		/* Perform write operation */
 635		smbseq.bytecnt = EEPROM_WR_CNT;
 636		eeseq.cmd = pdev->inieecmd | EEPROM_OP_WRITE;
 637		eeseq.eeaddr = pdev->eeaddr;
 638		eeseq.memaddr = cpu_to_le16(memaddr);
 639		eeseq.data = data[idx];
 640		ret = pdev->smb_write(pdev, &smbseq);
 641		if (ret != 0) {
 642			dev_err(dev,
 643				"Failed to write 0x%04hx:0x%02hhx to eeprom",
 644				memaddr, data[idx]);
 645			goto err_mutex_unlock;
 646		}
 647
 648		/*
 649		 * Check whether the data is successfully written by reading
 650		 * from the same EEPROM memory address.
 651		 */
 652		eeseq.data = ~data[idx];
 653		ret = idt_eeprom_read_byte(pdev, memaddr, &eeseq.data);
 654		if (ret != 0)
 655			goto err_mutex_unlock;
 656
 657		/* Check whether the read byte is the same as written one */
 658		if (eeseq.data != data[idx]) {
 659			dev_err(dev, "Values don't match 0x%02hhx != 0x%02hhx",
 660				eeseq.data, data[idx]);
 661			ret = -EREMOTEIO;
 662			goto err_mutex_unlock;
 663		}
 664
 665		/* Unlock IDT SMBus device */
 666err_mutex_unlock:
 667		mutex_unlock(&pdev->smb_mtx);
 668		if (ret != 0)
 669			return ret;
 670	}
 671
 672	return 0;
 673}
 674
 675/*
 676 * idt_eeprom_read() - EEPROM read operation
 677 * @pdev:	Pointer to the driver data
 678 * @memaddr:	Start EEPROM memory address
 679 * @len:	Length of data to read
 680 * @buf:	Buffer to read data to
 681 */
 682static int idt_eeprom_read(struct idt_89hpesx_dev *pdev, u16 memaddr, u16 len,
 683			   u8 *buf)
 684{
 685	int ret;
 686	u16 idx;
 687
 688	/* Read data byte-by-byte, retrying if it wasn't successful */
 689	for (idx = 0; idx < len; idx++, memaddr++) {
 690		/* Lock IDT SMBus device */
 691		mutex_lock(&pdev->smb_mtx);
 692
 693		/* Just read the byte to the buffer */
 694		ret = idt_eeprom_read_byte(pdev, memaddr, &buf[idx]);
 695
 696		/* Unlock IDT SMBus device */
 697		mutex_unlock(&pdev->smb_mtx);
 698
 699		/* Return error if read operation failed */
 700		if (ret != 0)
 701			return ret;
 702	}
 703
 704	return 0;
 705}
 706
 707/*===========================================================================
 708 *                          CSR IO-operations
 709 *===========================================================================
 710 */
 711
 712/*
 713 * idt_csr_write() - CSR write operation
 714 * @pdev:	Pointer to the driver data
 715 * @csraddr:	CSR address (with no two LS bits)
 716 * @data:	Data to be written to CSR
 717 */
 718static int idt_csr_write(struct idt_89hpesx_dev *pdev, u16 csraddr,
 719			 const u32 data)
 720{
 721	struct device *dev = &pdev->client->dev;
 722	struct idt_csr_seq csrseq;
 723	struct idt_smb_seq smbseq;
 724	int ret;
 725
 726	/* Initialize SMBus sequence fields */
 727	smbseq.ccode = pdev->iniccode | CCODE_CSR;
 728	smbseq.data = (u8 *)&csrseq;
 729
 730	/* Lock IDT SMBus device */
 731	mutex_lock(&pdev->smb_mtx);
 732
 733	/* Perform write operation */
 734	smbseq.bytecnt = CSR_WR_CNT;
 735	csrseq.cmd = pdev->inicsrcmd | CSR_OP_WRITE;
 736	csrseq.csraddr = cpu_to_le16(csraddr);
 737	csrseq.data = cpu_to_le32(data);
 738	ret = pdev->smb_write(pdev, &smbseq);
 739	if (ret != 0) {
 740		dev_err(dev, "Failed to write 0x%04x: 0x%04x to csr",
 741			CSR_REAL_ADDR(csraddr), data);
 742		goto err_mutex_unlock;
 743	}
 744
 745	/* Send CSR address to read data from */
 746	smbseq.bytecnt = CSR_WRRD_CNT;
 747	csrseq.cmd = pdev->inicsrcmd | CSR_OP_READ;
 748	ret = pdev->smb_write(pdev, &smbseq);
 749	if (ret != 0) {
 750		dev_err(dev, "Failed to init csr address 0x%04x",
 751			CSR_REAL_ADDR(csraddr));
 752		goto err_mutex_unlock;
 753	}
 754
 755	/* Perform read operation */
 756	smbseq.bytecnt = CSR_RD_CNT;
 757	ret = pdev->smb_read(pdev, &smbseq);
 758	if (ret != 0) {
 759		dev_err(dev, "Failed to read csr 0x%04x",
 760			CSR_REAL_ADDR(csraddr));
 761		goto err_mutex_unlock;
 762	}
 763
 764	/* Check whether IDT successfully retrieved CSR data */
 765	if (csrseq.cmd & (CSR_RERR | CSR_WERR)) {
 766		dev_err(dev, "IDT failed to perform CSR r/w");
 767		ret = -EREMOTEIO;
 768		goto err_mutex_unlock;
 769	}
 770
 771	/* Unlock IDT SMBus device */
 772err_mutex_unlock:
 773	mutex_unlock(&pdev->smb_mtx);
 774
 775	return ret;
 776}
 777
 778/*
 779 * idt_csr_read() - CSR read operation
 780 * @pdev:	Pointer to the driver data
 781 * @csraddr:	CSR address (with no two LS bits)
 782 * @data:	Data to be written to CSR
 783 */
 784static int idt_csr_read(struct idt_89hpesx_dev *pdev, u16 csraddr, u32 *data)
 785{
 786	struct device *dev = &pdev->client->dev;
 787	struct idt_csr_seq csrseq;
 788	struct idt_smb_seq smbseq;
 789	int ret;
 790
 791	/* Initialize SMBus sequence fields */
 792	smbseq.ccode = pdev->iniccode | CCODE_CSR;
 793	smbseq.data = (u8 *)&csrseq;
 794
 795	/* Lock IDT SMBus device */
 796	mutex_lock(&pdev->smb_mtx);
 797
 798	/* Send CSR register address before reading it */
 799	smbseq.bytecnt = CSR_WRRD_CNT;
 800	csrseq.cmd = pdev->inicsrcmd | CSR_OP_READ;
 801	csrseq.csraddr = cpu_to_le16(csraddr);
 802	ret = pdev->smb_write(pdev, &smbseq);
 803	if (ret != 0) {
 804		dev_err(dev, "Failed to init csr address 0x%04x",
 805			CSR_REAL_ADDR(csraddr));
 806		goto err_mutex_unlock;
 807	}
 808
 809	/* Perform read operation */
 810	smbseq.bytecnt = CSR_RD_CNT;
 811	ret = pdev->smb_read(pdev, &smbseq);
 812	if (ret != 0) {
 813		dev_err(dev, "Failed to read csr 0x%04x",
 814			CSR_REAL_ADDR(csraddr));
 815		goto err_mutex_unlock;
 816	}
 817
 818	/* Check whether IDT successfully retrieved CSR data */
 819	if (csrseq.cmd & (CSR_RERR | CSR_WERR)) {
 820		dev_err(dev, "IDT failed to perform CSR r/w");
 821		ret = -EREMOTEIO;
 822		goto err_mutex_unlock;
 823	}
 824
 825	/* Save data retrieved from IDT */
 826	*data = le32_to_cpu(csrseq.data);
 827
 828	/* Unlock IDT SMBus device */
 829err_mutex_unlock:
 830	mutex_unlock(&pdev->smb_mtx);
 831
 832	return ret;
 833}
 834
 835/*===========================================================================
 836 *                          Sysfs/debugfs-nodes IO-operations
 837 *===========================================================================
 838 */
 839
 840/*
 841 * eeprom_write() - EEPROM sysfs-node write callback
 842 * @filep:	Pointer to the file system node
 843 * @kobj:	Pointer to the kernel object related to the sysfs-node
 844 * @attr:	Attributes of the file
 845 * @buf:	Buffer to write data to
 846 * @off:	Offset at which data should be written to
 847 * @count:	Number of bytes to write
 848 */
 849static ssize_t eeprom_write(struct file *filp, struct kobject *kobj,
 850			    struct bin_attribute *attr,
 851			    char *buf, loff_t off, size_t count)
 852{
 853	struct idt_89hpesx_dev *pdev;
 854	int ret;
 855
 856	/* Retrieve driver data */
 857	pdev = dev_get_drvdata(kobj_to_dev(kobj));
 858
 859	/* Perform EEPROM write operation */
 860	ret = idt_eeprom_write(pdev, (u16)off, (u16)count, (u8 *)buf);
 861	return (ret != 0 ? ret : count);
 862}
 863
 864/*
 865 * eeprom_read() - EEPROM sysfs-node read callback
 866 * @filep:	Pointer to the file system node
 867 * @kobj:	Pointer to the kernel object related to the sysfs-node
 868 * @attr:	Attributes of the file
 869 * @buf:	Buffer to write data to
 870 * @off:	Offset at which data should be written to
 871 * @count:	Number of bytes to write
 872 */
 873static ssize_t eeprom_read(struct file *filp, struct kobject *kobj,
 874			   struct bin_attribute *attr,
 875			   char *buf, loff_t off, size_t count)
 876{
 877	struct idt_89hpesx_dev *pdev;
 878	int ret;
 879
 880	/* Retrieve driver data */
 881	pdev = dev_get_drvdata(kobj_to_dev(kobj));
 882
 883	/* Perform EEPROM read operation */
 884	ret = idt_eeprom_read(pdev, (u16)off, (u16)count, (u8 *)buf);
 885	return (ret != 0 ? ret : count);
 886}
 887
 888/*
 889 * idt_dbgfs_csr_write() - CSR debugfs-node write callback
 890 * @filep:	Pointer to the file system file descriptor
 891 * @buf:	Buffer to read data from
 892 * @count:	Size of the buffer
 893 * @offp:	Offset within the file
 894 *
 895 * It accepts either "0x<reg addr>:0x<value>" for saving register address
 896 * and writing value to specified DWORD register or "0x<reg addr>" for
 897 * just saving register address in order to perform next read operation.
 898 *
 899 * WARNING No spaces are allowed. Incoming string must be strictly formated as:
 900 * "<reg addr>:<value>". Register address must be aligned within 4 bytes
 901 * (one DWORD).
 902 */
 903static ssize_t idt_dbgfs_csr_write(struct file *filep, const char __user *ubuf,
 904				   size_t count, loff_t *offp)
 905{
 906	struct idt_89hpesx_dev *pdev = filep->private_data;
 907	char *colon_ch, *csraddr_str, *csrval_str;
 908	int ret;
 909	u32 csraddr, csrval;
 910	char *buf;
 911
 912	if (*offp)
 913		return 0;
 914
 915	/* Copy data from User-space */
 916	buf = memdup_user_nul(ubuf, count);
 917	if (IS_ERR(buf))
 918		return PTR_ERR(buf);
 919
 920	/* Find position of colon in the buffer */
 921	colon_ch = strnchr(buf, count, ':');
 922
 923	/*
 924	 * If there is colon passed then new CSR value should be parsed as
 925	 * well, so allocate buffer for CSR address substring.
 926	 * If no colon is found, then string must have just one number with
 927	 * no new CSR value
 928	 */
 929	if (colon_ch != NULL) {
 930		/* Copy the register address to the substring buffer */
 931		csraddr_str = kmemdup_nul(buf, colon_ch - buf, GFP_KERNEL);
 932		if (csraddr_str == NULL) {
 933			ret = -ENOMEM;
 934			goto free_buf;
 935		}
 936		/* Register value must follow the colon */
 937		csrval_str = colon_ch + 1;
 938	} else /* if (str_colon == NULL) */ {
 939		csraddr_str = (char *)buf; /* Just to shut warning up */
 940		csrval_str = NULL;
 941	}
 942
 943	/* Convert CSR address to u32 value */
 944	ret = kstrtou32(csraddr_str, 0, &csraddr);
 945	if (ret != 0)
 946		goto free_csraddr_str;
 947
 948	/* Check whether passed register address is valid */
 949	if (csraddr > CSR_MAX || !IS_ALIGNED(csraddr, SZ_4)) {
 950		ret = -EINVAL;
 951		goto free_csraddr_str;
 952	}
 953
 954	/* Shift register address to the right so to have u16 address */
 955	pdev->csr = (csraddr >> 2);
 956
 957	/* Parse new CSR value and send it to IDT, if colon has been found */
 958	if (colon_ch != NULL) {
 959		ret = kstrtou32(csrval_str, 0, &csrval);
 960		if (ret != 0)
 961			goto free_csraddr_str;
 962
 963		ret = idt_csr_write(pdev, pdev->csr, csrval);
 964		if (ret != 0)
 965			goto free_csraddr_str;
 966	}
 967
 968	/* Free memory only if colon has been found */
 969free_csraddr_str:
 970	if (colon_ch != NULL)
 971		kfree(csraddr_str);
 972
 973	/* Free buffer allocated for data retrieved from User-space */
 974free_buf:
 975	kfree(buf);
 976
 977	return (ret != 0 ? ret : count);
 978}
 979
 980/*
 981 * idt_dbgfs_csr_read() - CSR debugfs-node read callback
 982 * @filep:	Pointer to the file system file descriptor
 983 * @buf:	Buffer to write data to
 984 * @count:	Size of the buffer
 985 * @offp:	Offset within the file
 986 *
 987 * It just prints the pair "0x<reg addr>:0x<value>" to passed buffer.
 988 */
 989#define CSRBUF_SIZE	((size_t)32)
 990static ssize_t idt_dbgfs_csr_read(struct file *filep, char __user *ubuf,
 991				  size_t count, loff_t *offp)
 992{
 993	struct idt_89hpesx_dev *pdev = filep->private_data;
 994	u32 csraddr, csrval;
 995	char buf[CSRBUF_SIZE];
 996	int ret, size;
 997
 998	/* Perform CSR read operation */
 999	ret = idt_csr_read(pdev, pdev->csr, &csrval);
1000	if (ret != 0)
1001		return ret;
1002
1003	/* Shift register address to the left so to have real address */
1004	csraddr = ((u32)pdev->csr << 2);
1005
1006	/* Print the "0x<reg addr>:0x<value>" to buffer */
1007	size = snprintf(buf, CSRBUF_SIZE, "0x%05x:0x%08x\n",
1008		(unsigned int)csraddr, (unsigned int)csrval);
1009
1010	/* Copy data to User-space */
1011	return simple_read_from_buffer(ubuf, count, offp, buf, size);
1012}
1013
1014/*
1015 * eeprom_attribute - EEPROM sysfs-node attributes
1016 *
1017 * NOTE Size will be changed in compliance with OF node. EEPROM attribute will
1018 * be read-only as well if the corresponding flag is specified in OF node.
1019 */
1020static BIN_ATTR_RW(eeprom, EEPROM_DEF_SIZE);
1021
1022/*
1023 * csr_dbgfs_ops - CSR debugfs-node read/write operations
1024 */
1025static const struct file_operations csr_dbgfs_ops = {
1026	.owner = THIS_MODULE,
1027	.open = simple_open,
1028	.write = idt_dbgfs_csr_write,
1029	.read = idt_dbgfs_csr_read
1030};
1031
1032/*===========================================================================
1033 *                       Driver init/deinit methods
1034 *===========================================================================
1035 */
1036
1037/*
1038 * idt_set_defval() - disable EEPROM access by default
1039 * @pdev:	Pointer to the driver data
1040 */
1041static void idt_set_defval(struct idt_89hpesx_dev *pdev)
1042{
1043	/* If OF info is missing then use next values */
1044	pdev->eesize = 0;
1045	pdev->eero = true;
1046	pdev->inieecmd = 0;
1047	pdev->eeaddr = 0;
1048}
1049
1050static const struct i2c_device_id ee_ids[];
1051
1052/*
1053 * idt_ee_match_id() - check whether the node belongs to compatible EEPROMs
1054 */
1055static const struct i2c_device_id *idt_ee_match_id(struct fwnode_handle *fwnode)
1056{
1057	const struct i2c_device_id *id = ee_ids;
1058	const char *compatible, *p;
1059	char devname[I2C_NAME_SIZE];
1060	int ret;
1061
1062	ret = fwnode_property_read_string(fwnode, "compatible", &compatible);
1063	if (ret)
1064		return NULL;
1065
1066	p = strchr(compatible, ',');
1067	strscpy(devname, p ? p + 1 : compatible, sizeof(devname));
1068	/* Search through the device name */
1069	while (id->name[0]) {
1070		if (strcmp(devname, id->name) == 0)
1071			return id;
1072		id++;
1073	}
1074	return NULL;
1075}
1076
1077/*
1078 * idt_get_fw_data() - get IDT i2c-device parameters from device tree
1079 * @pdev:	Pointer to the driver data
1080 */
1081static void idt_get_fw_data(struct idt_89hpesx_dev *pdev)
1082{
1083	struct device *dev = &pdev->client->dev;
1084	struct fwnode_handle *fwnode;
1085	const struct i2c_device_id *ee_id = NULL;
1086	u32 eeprom_addr;
1087	int ret;
1088
1089	device_for_each_child_node(dev, fwnode) {
1090		ee_id = idt_ee_match_id(fwnode);
1091		if (ee_id)
1092			break;
1093
1094		dev_warn(dev, "Skip unsupported EEPROM device %pfw\n", fwnode);
1095	}
1096
1097	/* If there is no fwnode EEPROM device, then set zero size */
1098	if (!ee_id) {
1099		dev_warn(dev, "No fwnode, EEPROM access disabled");
1100		idt_set_defval(pdev);
1101		return;
1102	}
1103
1104	/* Retrieve EEPROM size */
1105	pdev->eesize = (u32)ee_id->driver_data;
1106
1107	/* Get custom EEPROM address from 'reg' attribute */
1108	ret = fwnode_property_read_u32(fwnode, "reg", &eeprom_addr);
1109	if (ret || (eeprom_addr == 0)) {
1110		dev_warn(dev, "No EEPROM reg found, use default address 0x%x",
1111			 EEPROM_DEF_ADDR);
1112		pdev->inieecmd = 0;
1113		pdev->eeaddr = EEPROM_DEF_ADDR << 1;
1114	} else {
1115		pdev->inieecmd = EEPROM_USA;
1116		pdev->eeaddr = eeprom_addr << 1;
1117	}
1118
1119	/* Check EEPROM 'read-only' flag */
1120	if (fwnode_property_read_bool(fwnode, "read-only"))
1121		pdev->eero = true;
1122	else /* if (!fwnode_property_read_bool(node, "read-only")) */
1123		pdev->eero = false;
1124
1125	fwnode_handle_put(fwnode);
1126	dev_info(dev, "EEPROM of %d bytes found by 0x%x",
1127		pdev->eesize, pdev->eeaddr);
1128}
1129
1130/*
1131 * idt_create_pdev() - create and init data structure of the driver
1132 * @client:	i2c client of IDT PCIe-switch device
1133 */
1134static struct idt_89hpesx_dev *idt_create_pdev(struct i2c_client *client)
1135{
1136	struct idt_89hpesx_dev *pdev;
1137
1138	/* Allocate memory for driver data */
1139	pdev = devm_kmalloc(&client->dev, sizeof(struct idt_89hpesx_dev),
1140		GFP_KERNEL);
1141	if (pdev == NULL)
1142		return ERR_PTR(-ENOMEM);
1143
1144	/* Initialize basic fields of the data */
1145	pdev->client = client;
1146	i2c_set_clientdata(client, pdev);
1147
1148	/* Read firmware nodes information */
1149	idt_get_fw_data(pdev);
1150
1151	/* Initialize basic CSR CMD field - use full DWORD-sized r/w ops */
1152	pdev->inicsrcmd = CSR_DWE;
1153	pdev->csr = CSR_DEF;
1154
1155	/* Enable Packet Error Checking if it's supported by adapter */
1156	if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_PEC)) {
1157		pdev->iniccode = CCODE_PEC;
1158		client->flags |= I2C_CLIENT_PEC;
1159	} else /* PEC is unsupported */ {
1160		pdev->iniccode = 0;
1161	}
1162
1163	return pdev;
1164}
1165
1166/*
1167 * idt_free_pdev() - free data structure of the driver
1168 * @pdev:	Pointer to the driver data
1169 */
1170static void idt_free_pdev(struct idt_89hpesx_dev *pdev)
1171{
1172	/* Clear driver data from device private field */
1173	i2c_set_clientdata(pdev->client, NULL);
1174}
1175
1176/*
1177 * idt_set_smbus_ops() - set supported SMBus operations
1178 * @pdev:	Pointer to the driver data
1179 * Return status of smbus check operations
1180 */
1181static int idt_set_smbus_ops(struct idt_89hpesx_dev *pdev)
1182{
1183	struct i2c_adapter *adapter = pdev->client->adapter;
1184	struct device *dev = &pdev->client->dev;
1185
1186	/* Check i2c adapter read functionality */
1187	if (i2c_check_functionality(adapter,
1188				    I2C_FUNC_SMBUS_READ_BLOCK_DATA)) {
1189		pdev->smb_read = idt_smb_read_block;
1190		dev_dbg(dev, "SMBus block-read op chosen");
1191	} else if (i2c_check_functionality(adapter,
1192					   I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
1193		pdev->smb_read = idt_smb_read_i2c_block;
1194		dev_dbg(dev, "SMBus i2c-block-read op chosen");
1195	} else if (i2c_check_functionality(adapter,
1196					   I2C_FUNC_SMBUS_READ_WORD_DATA) &&
1197		   i2c_check_functionality(adapter,
1198					   I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
1199		pdev->smb_read = idt_smb_read_word;
1200		dev_warn(dev, "Use slow word/byte SMBus read ops");
1201	} else if (i2c_check_functionality(adapter,
1202					   I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
1203		pdev->smb_read = idt_smb_read_byte;
1204		dev_warn(dev, "Use slow byte SMBus read op");
1205	} else /* no supported smbus read operations */ {
1206		dev_err(dev, "No supported SMBus read op");
1207		return -EPFNOSUPPORT;
1208	}
1209
1210	/* Check i2c adapter write functionality */
1211	if (i2c_check_functionality(adapter,
1212				    I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)) {
1213		pdev->smb_write = idt_smb_write_block;
1214		dev_dbg(dev, "SMBus block-write op chosen");
1215	} else if (i2c_check_functionality(adapter,
1216					   I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)) {
1217		pdev->smb_write = idt_smb_write_i2c_block;
1218		dev_dbg(dev, "SMBus i2c-block-write op chosen");
1219	} else if (i2c_check_functionality(adapter,
1220					   I2C_FUNC_SMBUS_WRITE_WORD_DATA) &&
1221		   i2c_check_functionality(adapter,
1222					   I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) {
1223		pdev->smb_write = idt_smb_write_word;
1224		dev_warn(dev, "Use slow word/byte SMBus write op");
1225	} else if (i2c_check_functionality(adapter,
1226					   I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) {
1227		pdev->smb_write = idt_smb_write_byte;
1228		dev_warn(dev, "Use slow byte SMBus write op");
1229	} else /* no supported smbus write operations */ {
1230		dev_err(dev, "No supported SMBus write op");
1231		return -EPFNOSUPPORT;
1232	}
1233
1234	/* Initialize IDT SMBus slave interface mutex */
1235	mutex_init(&pdev->smb_mtx);
1236
1237	return 0;
1238}
1239
1240/*
1241 * idt_check_dev() - check whether it's really IDT 89HPESx device
1242 * @pdev:	Pointer to the driver data
1243 * Return status of i2c adapter check operation
1244 */
1245static int idt_check_dev(struct idt_89hpesx_dev *pdev)
1246{
1247	struct device *dev = &pdev->client->dev;
1248	u32 viddid;
1249	int ret;
1250
1251	/* Read VID and DID directly from IDT memory space */
1252	ret = idt_csr_read(pdev, IDT_VIDDID_CSR, &viddid);
1253	if (ret != 0) {
1254		dev_err(dev, "Failed to read VID/DID");
1255		return ret;
1256	}
1257
1258	/* Check whether it's IDT device */
1259	if ((viddid & IDT_VID_MASK) != PCI_VENDOR_ID_IDT) {
1260		dev_err(dev, "Got unsupported VID/DID: 0x%08x", viddid);
1261		return -ENODEV;
1262	}
1263
1264	dev_info(dev, "Found IDT 89HPES device VID:0x%04x, DID:0x%04x",
1265		(viddid & IDT_VID_MASK), (viddid >> 16));
1266
1267	return 0;
1268}
1269
1270/*
1271 * idt_create_sysfs_files() - create sysfs attribute files
1272 * @pdev:	Pointer to the driver data
1273 * Return status of operation
1274 */
1275static int idt_create_sysfs_files(struct idt_89hpesx_dev *pdev)
1276{
1277	struct device *dev = &pdev->client->dev;
1278	int ret;
1279
1280	/* Don't do anything if EEPROM isn't accessible */
1281	if (pdev->eesize == 0) {
1282		dev_dbg(dev, "Skip creating sysfs-files");
1283		return 0;
1284	}
1285
1286	/*
1287	 * Allocate memory for attribute file and copy the declared EEPROM attr
1288	 * structure to change some of fields
1289	 */
1290	pdev->ee_file = devm_kmemdup(dev, &bin_attr_eeprom,
1291				     sizeof(*pdev->ee_file), GFP_KERNEL);
1292	if (!pdev->ee_file)
1293		return -ENOMEM;
1294
1295	/* In case of read-only EEPROM get rid of write ability */
1296	if (pdev->eero) {
1297		pdev->ee_file->attr.mode &= ~0200;
1298		pdev->ee_file->write = NULL;
1299	}
1300	/* Create EEPROM sysfs file */
1301	pdev->ee_file->size = pdev->eesize;
1302	ret = sysfs_create_bin_file(&dev->kobj, pdev->ee_file);
1303	if (ret != 0) {
1304		dev_err(dev, "Failed to create EEPROM sysfs-node");
1305		return ret;
1306	}
1307
1308	return 0;
1309}
1310
1311/*
1312 * idt_remove_sysfs_files() - remove sysfs attribute files
1313 * @pdev:	Pointer to the driver data
1314 */
1315static void idt_remove_sysfs_files(struct idt_89hpesx_dev *pdev)
1316{
1317	struct device *dev = &pdev->client->dev;
1318
1319	/* Don't do anything if EEPROM wasn't accessible */
1320	if (pdev->eesize == 0)
1321		return;
1322
1323	/* Remove EEPROM sysfs file */
1324	sysfs_remove_bin_file(&dev->kobj, pdev->ee_file);
1325}
1326
1327/*
1328 * idt_create_dbgfs_files() - create debugfs files
1329 * @pdev:	Pointer to the driver data
1330 */
1331#define CSRNAME_LEN	((size_t)32)
1332static void idt_create_dbgfs_files(struct idt_89hpesx_dev *pdev)
1333{
1334	struct i2c_client *cli = pdev->client;
1335	char fname[CSRNAME_LEN];
1336
1337	/* Create Debugfs directory for CSR file */
1338	snprintf(fname, CSRNAME_LEN, "%d-%04hx", cli->adapter->nr, cli->addr);
1339	pdev->csr_dir = debugfs_create_dir(fname, csr_dbgdir);
1340
1341	/* Create Debugfs file for CSR read/write operations */
1342	debugfs_create_file(cli->name, 0600, pdev->csr_dir, pdev,
1343			    &csr_dbgfs_ops);
1344}
1345
1346/*
1347 * idt_remove_dbgfs_files() - remove debugfs files
1348 * @pdev:	Pointer to the driver data
1349 */
1350static void idt_remove_dbgfs_files(struct idt_89hpesx_dev *pdev)
1351{
1352	/* Remove CSR directory and it sysfs-node */
1353	debugfs_remove_recursive(pdev->csr_dir);
1354}
1355
1356/*
1357 * idt_probe() - IDT 89HPESx driver probe() callback method
1358 */
1359static int idt_probe(struct i2c_client *client)
1360{
1361	struct idt_89hpesx_dev *pdev;
1362	int ret;
1363
1364	/* Create driver data */
1365	pdev = idt_create_pdev(client);
1366	if (IS_ERR(pdev))
1367		return PTR_ERR(pdev);
1368
1369	/* Set SMBus operations */
1370	ret = idt_set_smbus_ops(pdev);
1371	if (ret != 0)
1372		goto err_free_pdev;
1373
1374	/* Check whether it is truly IDT 89HPESx device */
1375	ret = idt_check_dev(pdev);
1376	if (ret != 0)
1377		goto err_free_pdev;
1378
1379	/* Create sysfs files */
1380	ret = idt_create_sysfs_files(pdev);
1381	if (ret != 0)
1382		goto err_free_pdev;
1383
1384	/* Create debugfs files */
1385	idt_create_dbgfs_files(pdev);
1386
1387	return 0;
1388
1389err_free_pdev:
1390	idt_free_pdev(pdev);
1391
1392	return ret;
1393}
1394
1395/*
1396 * idt_remove() - IDT 89HPESx driver remove() callback method
1397 */
1398static void idt_remove(struct i2c_client *client)
1399{
1400	struct idt_89hpesx_dev *pdev = i2c_get_clientdata(client);
1401
1402	/* Remove debugfs files first */
1403	idt_remove_dbgfs_files(pdev);
1404
1405	/* Remove sysfs files */
1406	idt_remove_sysfs_files(pdev);
1407
1408	/* Discard driver data structure */
1409	idt_free_pdev(pdev);
1410}
1411
1412/*
1413 * ee_ids - array of supported EEPROMs
1414 */
1415static const struct i2c_device_id ee_ids[] = {
1416	{ "24c32",  4096},
1417	{ "24c64",  8192},
1418	{ "24c128", 16384},
1419	{ "24c256", 32768},
1420	{ "24c512", 65536},
1421	{}
1422};
1423MODULE_DEVICE_TABLE(i2c, ee_ids);
1424
1425/*
1426 * idt_ids - supported IDT 89HPESx devices
1427 */
1428static const struct i2c_device_id idt_ids[] = {
1429	{ "89hpes8nt2", 0 },
1430	{ "89hpes12nt3", 0 },
1431
1432	{ "89hpes24nt6ag2", 0 },
1433	{ "89hpes32nt8ag2", 0 },
1434	{ "89hpes32nt8bg2", 0 },
1435	{ "89hpes12nt12g2", 0 },
1436	{ "89hpes16nt16g2", 0 },
1437	{ "89hpes24nt24g2", 0 },
1438	{ "89hpes32nt24ag2", 0 },
1439	{ "89hpes32nt24bg2", 0 },
1440
1441	{ "89hpes12n3", 0 },
1442	{ "89hpes12n3a", 0 },
1443	{ "89hpes24n3", 0 },
1444	{ "89hpes24n3a", 0 },
1445
1446	{ "89hpes32h8", 0 },
1447	{ "89hpes32h8g2", 0 },
1448	{ "89hpes48h12", 0 },
1449	{ "89hpes48h12g2", 0 },
1450	{ "89hpes48h12ag2", 0 },
1451	{ "89hpes16h16", 0 },
1452	{ "89hpes22h16", 0 },
1453	{ "89hpes22h16g2", 0 },
1454	{ "89hpes34h16", 0 },
1455	{ "89hpes34h16g2", 0 },
1456	{ "89hpes64h16", 0 },
1457	{ "89hpes64h16g2", 0 },
1458	{ "89hpes64h16ag2", 0 },
1459
1460	/* { "89hpes3t3", 0 }, // No SMBus-slave iface */
1461	{ "89hpes12t3g2", 0 },
1462	{ "89hpes24t3g2", 0 },
1463	/* { "89hpes4t4", 0 }, // No SMBus-slave iface */
1464	{ "89hpes16t4", 0 },
1465	{ "89hpes4t4g2", 0 },
1466	{ "89hpes10t4g2", 0 },
1467	{ "89hpes16t4g2", 0 },
1468	{ "89hpes16t4ag2", 0 },
1469	{ "89hpes5t5", 0 },
1470	{ "89hpes6t5", 0 },
1471	{ "89hpes8t5", 0 },
1472	{ "89hpes8t5a", 0 },
1473	{ "89hpes24t6", 0 },
1474	{ "89hpes6t6g2", 0 },
1475	{ "89hpes24t6g2", 0 },
1476	{ "89hpes16t7", 0 },
1477	{ "89hpes32t8", 0 },
1478	{ "89hpes32t8g2", 0 },
1479	{ "89hpes48t12", 0 },
1480	{ "89hpes48t12g2", 0 },
1481	{ /* END OF LIST */ }
1482};
1483MODULE_DEVICE_TABLE(i2c, idt_ids);
1484
1485static const struct of_device_id idt_of_match[] = {
1486	{ .compatible = "idt,89hpes8nt2", },
1487	{ .compatible = "idt,89hpes12nt3", },
1488
1489	{ .compatible = "idt,89hpes24nt6ag2", },
1490	{ .compatible = "idt,89hpes32nt8ag2", },
1491	{ .compatible = "idt,89hpes32nt8bg2", },
1492	{ .compatible = "idt,89hpes12nt12g2", },
1493	{ .compatible = "idt,89hpes16nt16g2", },
1494	{ .compatible = "idt,89hpes24nt24g2", },
1495	{ .compatible = "idt,89hpes32nt24ag2", },
1496	{ .compatible = "idt,89hpes32nt24bg2", },
1497
1498	{ .compatible = "idt,89hpes12n3", },
1499	{ .compatible = "idt,89hpes12n3a", },
1500	{ .compatible = "idt,89hpes24n3", },
1501	{ .compatible = "idt,89hpes24n3a", },
1502
1503	{ .compatible = "idt,89hpes32h8", },
1504	{ .compatible = "idt,89hpes32h8g2", },
1505	{ .compatible = "idt,89hpes48h12", },
1506	{ .compatible = "idt,89hpes48h12g2", },
1507	{ .compatible = "idt,89hpes48h12ag2", },
1508	{ .compatible = "idt,89hpes16h16", },
1509	{ .compatible = "idt,89hpes22h16", },
1510	{ .compatible = "idt,89hpes22h16g2", },
1511	{ .compatible = "idt,89hpes34h16", },
1512	{ .compatible = "idt,89hpes34h16g2", },
1513	{ .compatible = "idt,89hpes64h16", },
1514	{ .compatible = "idt,89hpes64h16g2", },
1515	{ .compatible = "idt,89hpes64h16ag2", },
1516
1517	{ .compatible = "idt,89hpes12t3g2", },
1518	{ .compatible = "idt,89hpes24t3g2", },
1519
1520	{ .compatible = "idt,89hpes16t4", },
1521	{ .compatible = "idt,89hpes4t4g2", },
1522	{ .compatible = "idt,89hpes10t4g2", },
1523	{ .compatible = "idt,89hpes16t4g2", },
1524	{ .compatible = "idt,89hpes16t4ag2", },
1525	{ .compatible = "idt,89hpes5t5", },
1526	{ .compatible = "idt,89hpes6t5", },
1527	{ .compatible = "idt,89hpes8t5", },
1528	{ .compatible = "idt,89hpes8t5a", },
1529	{ .compatible = "idt,89hpes24t6", },
1530	{ .compatible = "idt,89hpes6t6g2", },
1531	{ .compatible = "idt,89hpes24t6g2", },
1532	{ .compatible = "idt,89hpes16t7", },
1533	{ .compatible = "idt,89hpes32t8", },
1534	{ .compatible = "idt,89hpes32t8g2", },
1535	{ .compatible = "idt,89hpes48t12", },
1536	{ .compatible = "idt,89hpes48t12g2", },
1537	{ },
1538};
1539MODULE_DEVICE_TABLE(of, idt_of_match);
1540
1541/*
1542 * idt_driver - IDT 89HPESx driver structure
1543 */
1544static struct i2c_driver idt_driver = {
1545	.driver = {
1546		.name = IDT_NAME,
1547		.of_match_table = idt_of_match,
1548	},
1549	.probe = idt_probe,
1550	.remove = idt_remove,
1551	.id_table = idt_ids,
1552};
1553
1554/*
1555 * idt_init() - IDT 89HPESx driver init() callback method
1556 */
1557static int __init idt_init(void)
1558{
1559	int ret;
1560
1561	/* Create Debugfs directory first */
1562	if (debugfs_initialized())
1563		csr_dbgdir = debugfs_create_dir("idt_csr", NULL);
1564
1565	/* Add new i2c-device driver */
1566	ret = i2c_add_driver(&idt_driver);
1567	if (ret) {
1568		debugfs_remove_recursive(csr_dbgdir);
1569		return ret;
1570	}
1571
1572	return 0;
1573}
1574module_init(idt_init);
1575
1576/*
1577 * idt_exit() - IDT 89HPESx driver exit() callback method
1578 */
1579static void __exit idt_exit(void)
1580{
1581	/* Discard debugfs directory and all files if any */
1582	debugfs_remove_recursive(csr_dbgdir);
1583
1584	/* Unregister i2c-device driver */
1585	i2c_del_driver(&idt_driver);
1586}
1587module_exit(idt_exit);