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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 * @csr_file:	CSR read/write debugfs-node
 119 */
 120struct idt_smb_seq;
 121struct idt_89hpesx_dev {
 122	u32 eesize;
 123	bool eero;
 124	u8 eeaddr;
 125
 126	u8 inieecmd;
 127	u8 inicsrcmd;
 128	u8 iniccode;
 129
 130	u16 csr;
 131
 132	int (*smb_write)(struct idt_89hpesx_dev *, const struct idt_smb_seq *);
 133	int (*smb_read)(struct idt_89hpesx_dev *, struct idt_smb_seq *);
 134	struct mutex smb_mtx;
 135
 136	struct i2c_client *client;
 137
 138	struct bin_attribute *ee_file;
 139	struct dentry *csr_dir;
 140	struct dentry *csr_file;
 141};
 142
 143/*
 144 * struct idt_smb_seq - sequence of data to be read/written from/to IDT 89HPESx
 145 * @ccode:	SMBus command code
 146 * @bytecnt:	Byte count of operation
 147 * @data:	Data to by written
 148 */
 149struct idt_smb_seq {
 150	u8 ccode;
 151	u8 bytecnt;
 152	u8 *data;
 153};
 154
 155/*
 156 * struct idt_eeprom_seq - sequence of data to be read/written from/to EEPROM
 157 * @cmd:	Transaction CMD
 158 * @eeaddr:	EEPROM custom address
 159 * @memaddr:	Internal memory address of EEPROM
 160 * @data:	Data to be written at the memory address
 161 */
 162struct idt_eeprom_seq {
 163	u8 cmd;
 164	u8 eeaddr;
 165	u16 memaddr;
 166	u8 data;
 167} __packed;
 168
 169/*
 170 * struct idt_csr_seq - sequence of data to be read/written from/to CSR
 171 * @cmd:	Transaction CMD
 172 * @csraddr:	Internal IDT device CSR address
 173 * @data:	Data to be read/written from/to the CSR address
 174 */
 175struct idt_csr_seq {
 176	u8 cmd;
 177	u16 csraddr;
 178	u32 data;
 179} __packed;
 180
 181/*
 182 * SMBus command code macros
 183 * @CCODE_END:		Indicates the end of transaction
 184 * @CCODE_START:	Indicates the start of transaction
 185 * @CCODE_CSR:		CSR read/write transaction
 186 * @CCODE_EEPROM:	EEPROM read/write transaction
 187 * @CCODE_BYTE:		Supplied data has BYTE length
 188 * @CCODE_WORD:		Supplied data has WORD length
 189 * @CCODE_BLOCK:	Supplied data has variable length passed in bytecnt
 190 *			byte right following CCODE byte
 191 */
 192#define CCODE_END	((u8)0x01)
 193#define CCODE_START	((u8)0x02)
 194#define CCODE_CSR	((u8)0x00)
 195#define CCODE_EEPROM	((u8)0x04)
 196#define CCODE_BYTE	((u8)0x00)
 197#define CCODE_WORD	((u8)0x20)
 198#define CCODE_BLOCK	((u8)0x40)
 199#define CCODE_PEC	((u8)0x80)
 200
 201/*
 202 * EEPROM command macros
 203 * @EEPROM_OP_WRITE:	EEPROM write operation
 204 * @EEPROM_OP_READ:	EEPROM read operation
 205 * @EEPROM_USA:		Use specified address of EEPROM
 206 * @EEPROM_NAERR:	EEPROM device is not ready to respond
 207 * @EEPROM_LAERR:	EEPROM arbitration loss error
 208 * @EEPROM_MSS:		EEPROM misplace start & stop bits error
 209 * @EEPROM_WR_CNT:	Bytes count to perform write operation
 210 * @EEPROM_WRRD_CNT:	Bytes count to write before reading
 211 * @EEPROM_RD_CNT:	Bytes count to perform read operation
 212 * @EEPROM_DEF_SIZE:	Fall back size of EEPROM
 213 * @EEPROM_DEF_ADDR:	Defatul EEPROM address
 214 * @EEPROM_TOUT:	Timeout before retry read operation if eeprom is busy
 215 */
 216#define EEPROM_OP_WRITE	((u8)0x00)
 217#define EEPROM_OP_READ	((u8)0x01)
 218#define EEPROM_USA	((u8)0x02)
 219#define EEPROM_NAERR	((u8)0x08)
 220#define EEPROM_LAERR    ((u8)0x10)
 221#define EEPROM_MSS	((u8)0x20)
 222#define EEPROM_WR_CNT	((u8)5)
 223#define EEPROM_WRRD_CNT	((u8)4)
 224#define EEPROM_RD_CNT	((u8)5)
 225#define EEPROM_DEF_SIZE	((u16)4096)
 226#define EEPROM_DEF_ADDR	((u8)0x50)
 227#define EEPROM_TOUT	(100)
 228
 229/*
 230 * CSR command macros
 231 * @CSR_DWE:		Enable all four bytes of the operation
 232 * @CSR_OP_WRITE:	CSR write operation
 233 * @CSR_OP_READ:	CSR read operation
 234 * @CSR_RERR:		Read operation error
 235 * @CSR_WERR:		Write operation error
 236 * @CSR_WR_CNT:		Bytes count to perform write operation
 237 * @CSR_WRRD_CNT:	Bytes count to write before reading
 238 * @CSR_RD_CNT:		Bytes count to perform read operation
 239 * @CSR_MAX:		Maximum CSR address
 240 * @CSR_DEF:		Default CSR address
 241 * @CSR_REAL_ADDR:	CSR real unshifted address
 242 */
 243#define CSR_DWE			((u8)0x0F)
 244#define CSR_OP_WRITE		((u8)0x00)
 245#define CSR_OP_READ		((u8)0x10)
 246#define CSR_RERR		((u8)0x40)
 247#define CSR_WERR		((u8)0x80)
 248#define CSR_WR_CNT		((u8)7)
 249#define CSR_WRRD_CNT		((u8)3)
 250#define CSR_RD_CNT		((u8)7)
 251#define CSR_MAX			((u32)0x3FFFF)
 252#define CSR_DEF			((u16)0x0000)
 253#define CSR_REAL_ADDR(val)	((unsigned int)val << 2)
 254
 255/*
 256 * IDT 89HPESx basic register
 257 * @IDT_VIDDID_CSR:	PCIe VID and DID of IDT 89HPESx
 258 * @IDT_VID_MASK:	Mask of VID
 259 */
 260#define IDT_VIDDID_CSR	((u32)0x0000)
 261#define IDT_VID_MASK	((u32)0xFFFF)
 262
 263/*
 264 * IDT 89HPESx can send NACK when new command is sent before previous one
 265 * fininshed execution. In this case driver retries operation
 266 * certain times.
 267 * @RETRY_CNT:		Number of retries before giving up and fail
 268 * @idt_smb_safe:	Generate a retry loop on corresponding SMBus method
 269 */
 270#define RETRY_CNT (128)
 271#define idt_smb_safe(ops, args...) ({ \
 272	int __retry = RETRY_CNT; \
 273	s32 __sts; \
 274	do { \
 275		__sts = i2c_smbus_ ## ops ## _data(args); \
 276	} while (__retry-- && __sts < 0); \
 277	__sts; \
 278})
 279
 280/*===========================================================================
 281 *                         i2c bus level IO-operations
 282 *===========================================================================
 283 */
 284
 285/*
 286 * idt_smb_write_byte() - SMBus write method when I2C_SMBUS_BYTE_DATA operation
 287 *                        is only available
 288 * @pdev:	Pointer to the driver data
 289 * @seq:	Sequence of data to be written
 290 */
 291static int idt_smb_write_byte(struct idt_89hpesx_dev *pdev,
 292			      const struct idt_smb_seq *seq)
 293{
 294	s32 sts;
 295	u8 ccode;
 296	int idx;
 297
 298	/* Loop over the supplied data sending byte one-by-one */
 299	for (idx = 0; idx < seq->bytecnt; idx++) {
 300		/* Collect the command code byte */
 301		ccode = seq->ccode | CCODE_BYTE;
 302		if (idx == 0)
 303			ccode |= CCODE_START;
 304		if (idx == seq->bytecnt - 1)
 305			ccode |= CCODE_END;
 306
 307		/* Send data to the device */
 308		sts = idt_smb_safe(write_byte, pdev->client, ccode,
 309			seq->data[idx]);
 310		if (sts != 0)
 311			return (int)sts;
 312	}
 313
 314	return 0;
 315}
 316
 317/*
 318 * idt_smb_read_byte() - SMBus read method when I2C_SMBUS_BYTE_DATA operation
 319 *                        is only available
 320 * @pdev:	Pointer to the driver data
 321 * @seq:	Buffer to read data to
 322 */
 323static int idt_smb_read_byte(struct idt_89hpesx_dev *pdev,
 324			     struct idt_smb_seq *seq)
 325{
 326	s32 sts;
 327	u8 ccode;
 328	int idx;
 329
 330	/* Loop over the supplied buffer receiving byte one-by-one */
 331	for (idx = 0; idx < seq->bytecnt; idx++) {
 332		/* Collect the command code byte */
 333		ccode = seq->ccode | CCODE_BYTE;
 334		if (idx == 0)
 335			ccode |= CCODE_START;
 336		if (idx == seq->bytecnt - 1)
 337			ccode |= CCODE_END;
 338
 339		/* Read data from the device */
 340		sts = idt_smb_safe(read_byte, pdev->client, ccode);
 341		if (sts < 0)
 342			return (int)sts;
 343
 344		seq->data[idx] = (u8)sts;
 345	}
 346
 347	return 0;
 348}
 349
 350/*
 351 * idt_smb_write_word() - SMBus write method when I2C_SMBUS_BYTE_DATA and
 352 *                        I2C_FUNC_SMBUS_WORD_DATA operations are available
 353 * @pdev:	Pointer to the driver data
 354 * @seq:	Sequence of data to be written
 355 */
 356static int idt_smb_write_word(struct idt_89hpesx_dev *pdev,
 357			      const struct idt_smb_seq *seq)
 358{
 359	s32 sts;
 360	u8 ccode;
 361	int idx, evencnt;
 362
 363	/* Calculate the even count of data to send */
 364	evencnt = seq->bytecnt - (seq->bytecnt % 2);
 365
 366	/* Loop over the supplied data sending two bytes at a time */
 367	for (idx = 0; idx < evencnt; idx += 2) {
 368		/* Collect the command code byte */
 369		ccode = seq->ccode | CCODE_WORD;
 370		if (idx == 0)
 371			ccode |= CCODE_START;
 372		if (idx == evencnt - 2)
 373			ccode |= CCODE_END;
 374
 375		/* Send word data to the device */
 376		sts = idt_smb_safe(write_word, pdev->client, ccode,
 377			*(u16 *)&seq->data[idx]);
 378		if (sts != 0)
 379			return (int)sts;
 380	}
 381
 382	/* If there is odd number of bytes then send just one last byte */
 383	if (seq->bytecnt != evencnt) {
 384		/* Collect the command code byte */
 385		ccode = seq->ccode | CCODE_BYTE | CCODE_END;
 386		if (idx == 0)
 387			ccode |= CCODE_START;
 388
 389		/* Send byte data to the device */
 390		sts = idt_smb_safe(write_byte, pdev->client, ccode,
 391			seq->data[idx]);
 392		if (sts != 0)
 393			return (int)sts;
 394	}
 395
 396	return 0;
 397}
 398
 399/*
 400 * idt_smb_read_word() - SMBus read method when I2C_SMBUS_BYTE_DATA and
 401 *                       I2C_FUNC_SMBUS_WORD_DATA operations are available
 402 * @pdev:	Pointer to the driver data
 403 * @seq:	Buffer to read data to
 404 */
 405static int idt_smb_read_word(struct idt_89hpesx_dev *pdev,
 406			     struct idt_smb_seq *seq)
 407{
 408	s32 sts;
 409	u8 ccode;
 410	int idx, evencnt;
 411
 412	/* Calculate the even count of data to send */
 413	evencnt = seq->bytecnt - (seq->bytecnt % 2);
 414
 415	/* Loop over the supplied data reading two bytes at a time */
 416	for (idx = 0; idx < evencnt; idx += 2) {
 417		/* Collect the command code byte */
 418		ccode = seq->ccode | CCODE_WORD;
 419		if (idx == 0)
 420			ccode |= CCODE_START;
 421		if (idx == evencnt - 2)
 422			ccode |= CCODE_END;
 423
 424		/* Read word data from the device */
 425		sts = idt_smb_safe(read_word, pdev->client, ccode);
 426		if (sts < 0)
 427			return (int)sts;
 428
 429		*(u16 *)&seq->data[idx] = (u16)sts;
 430	}
 431
 432	/* If there is odd number of bytes then receive just one last byte */
 433	if (seq->bytecnt != evencnt) {
 434		/* Collect the command code byte */
 435		ccode = seq->ccode | CCODE_BYTE | CCODE_END;
 436		if (idx == 0)
 437			ccode |= CCODE_START;
 438
 439		/* Read last data byte from the device */
 440		sts = idt_smb_safe(read_byte, pdev->client, ccode);
 441		if (sts < 0)
 442			return (int)sts;
 443
 444		seq->data[idx] = (u8)sts;
 445	}
 446
 447	return 0;
 448}
 449
 450/*
 451 * idt_smb_write_block() - SMBus write method when I2C_SMBUS_BLOCK_DATA
 452 *                         operation is available
 453 * @pdev:	Pointer to the driver data
 454 * @seq:	Sequence of data to be written
 455 */
 456static int idt_smb_write_block(struct idt_89hpesx_dev *pdev,
 457			       const struct idt_smb_seq *seq)
 458{
 459	u8 ccode;
 460
 461	/* Return error if too much data passed to send */
 462	if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX)
 463		return -EINVAL;
 464
 465	/* Collect the command code byte */
 466	ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END;
 467
 468	/* Send block of data to the device */
 469	return idt_smb_safe(write_block, pdev->client, ccode, seq->bytecnt,
 470		seq->data);
 471}
 472
 473/*
 474 * idt_smb_read_block() - SMBus read method when I2C_SMBUS_BLOCK_DATA
 475 *                        operation is available
 476 * @pdev:	Pointer to the driver data
 477 * @seq:	Buffer to read data to
 478 */
 479static int idt_smb_read_block(struct idt_89hpesx_dev *pdev,
 480			      struct idt_smb_seq *seq)
 481{
 482	s32 sts;
 483	u8 ccode;
 484
 485	/* Return error if too much data passed to send */
 486	if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX)
 487		return -EINVAL;
 488
 489	/* Collect the command code byte */
 490	ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END;
 491
 492	/* Read block of data from the device */
 493	sts = idt_smb_safe(read_block, pdev->client, ccode, seq->data);
 494	if (sts != seq->bytecnt)
 495		return (sts < 0 ? sts : -ENODATA);
 496
 497	return 0;
 498}
 499
 500/*
 501 * idt_smb_write_i2c_block() - SMBus write method when I2C_SMBUS_I2C_BLOCK_DATA
 502 *                             operation is available
 503 * @pdev:	Pointer to the driver data
 504 * @seq:	Sequence of data to be written
 505 *
 506 * NOTE It's usual SMBus write block operation, except the actual data length is
 507 * sent as first byte of data
 508 */
 509static int idt_smb_write_i2c_block(struct idt_89hpesx_dev *pdev,
 510				   const struct idt_smb_seq *seq)
 511{
 512	u8 ccode, buf[I2C_SMBUS_BLOCK_MAX + 1];
 513
 514	/* Return error if too much data passed to send */
 515	if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX)
 516		return -EINVAL;
 517
 518	/* Collect the data to send. Length byte must be added prior the data */
 519	buf[0] = seq->bytecnt;
 520	memcpy(&buf[1], seq->data, seq->bytecnt);
 521
 522	/* Collect the command code byte */
 523	ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END;
 524
 525	/* Send length and block of data to the device */
 526	return idt_smb_safe(write_i2c_block, pdev->client, ccode,
 527		seq->bytecnt + 1, buf);
 528}
 529
 530/*
 531 * idt_smb_read_i2c_block() - SMBus read method when I2C_SMBUS_I2C_BLOCK_DATA
 532 *                            operation is available
 533 * @pdev:	Pointer to the driver data
 534 * @seq:	Buffer to read data to
 535 *
 536 * NOTE It's usual SMBus read block operation, except the actual data length is
 537 * retrieved as first byte of data
 538 */
 539static int idt_smb_read_i2c_block(struct idt_89hpesx_dev *pdev,
 540				  struct idt_smb_seq *seq)
 541{
 542	u8 ccode, buf[I2C_SMBUS_BLOCK_MAX + 1];
 543	s32 sts;
 544
 545	/* Return error if too much data passed to send */
 546	if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX)
 547		return -EINVAL;
 548
 549	/* Collect the command code byte */
 550	ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END;
 551
 552	/* Read length and block of data from the device */
 553	sts = idt_smb_safe(read_i2c_block, pdev->client, ccode,
 554		seq->bytecnt + 1, buf);
 555	if (sts != seq->bytecnt + 1)
 556		return (sts < 0 ? sts : -ENODATA);
 557	if (buf[0] != seq->bytecnt)
 558		return -ENODATA;
 559
 560	/* Copy retrieved data to the output data buffer */
 561	memcpy(seq->data, &buf[1], seq->bytecnt);
 562
 563	return 0;
 564}
 565
 566/*===========================================================================
 567 *                          EEPROM IO-operations
 568 *===========================================================================
 569 */
 570
 571/*
 572 * idt_eeprom_read_byte() - read just one byte from EEPROM
 573 * @pdev:	Pointer to the driver data
 574 * @memaddr:	Start EEPROM memory address
 575 * @data:	Data to be written to EEPROM
 576 */
 577static int idt_eeprom_read_byte(struct idt_89hpesx_dev *pdev, u16 memaddr,
 578				u8 *data)
 579{
 580	struct device *dev = &pdev->client->dev;
 581	struct idt_eeprom_seq eeseq;
 582	struct idt_smb_seq smbseq;
 583	int ret, retry;
 584
 585	/* Initialize SMBus sequence fields */
 586	smbseq.ccode = pdev->iniccode | CCODE_EEPROM;
 587	smbseq.data = (u8 *)&eeseq;
 588
 589	/*
 590	 * Sometimes EEPROM may respond with NACK if it's busy with previous
 591	 * operation, so we need to perform a few attempts of read cycle
 592	 */
 593	retry = RETRY_CNT;
 594	do {
 595		/* Send EEPROM memory address to read data from */
 596		smbseq.bytecnt = EEPROM_WRRD_CNT;
 597		eeseq.cmd = pdev->inieecmd | EEPROM_OP_READ;
 598		eeseq.eeaddr = pdev->eeaddr;
 599		eeseq.memaddr = cpu_to_le16(memaddr);
 600		ret = pdev->smb_write(pdev, &smbseq);
 601		if (ret != 0) {
 602			dev_err(dev, "Failed to init eeprom addr 0x%02hhx",
 603				memaddr);
 604			break;
 605		}
 606
 607		/* Perform read operation */
 608		smbseq.bytecnt = EEPROM_RD_CNT;
 609		ret = pdev->smb_read(pdev, &smbseq);
 610		if (ret != 0) {
 611			dev_err(dev, "Failed to read eeprom data 0x%02hhx",
 612				memaddr);
 613			break;
 614		}
 615
 616		/* Restart read operation if the device is busy */
 617		if (retry && (eeseq.cmd & EEPROM_NAERR)) {
 618			dev_dbg(dev, "EEPROM busy, retry reading after %d ms",
 619				EEPROM_TOUT);
 620			msleep(EEPROM_TOUT);
 621			continue;
 622		}
 623
 624		/* Check whether IDT successfully read data from EEPROM */
 625		if (eeseq.cmd & (EEPROM_NAERR | EEPROM_LAERR | EEPROM_MSS)) {
 626			dev_err(dev,
 627				"Communication with eeprom failed, cmd 0x%hhx",
 628				eeseq.cmd);
 629			ret = -EREMOTEIO;
 630			break;
 631		}
 632
 633		/* Save retrieved data and exit the loop */
 634		*data = eeseq.data;
 635		break;
 636	} while (retry--);
 637
 638	/* Return the status of operation */
 639	return ret;
 640}
 641
 642/*
 643 * idt_eeprom_write() - EEPROM write operation
 644 * @pdev:	Pointer to the driver data
 645 * @memaddr:	Start EEPROM memory address
 646 * @len:	Length of data to be written
 647 * @data:	Data to be written to EEPROM
 648 */
 649static int idt_eeprom_write(struct idt_89hpesx_dev *pdev, u16 memaddr, u16 len,
 650			    const u8 *data)
 651{
 652	struct device *dev = &pdev->client->dev;
 653	struct idt_eeprom_seq eeseq;
 654	struct idt_smb_seq smbseq;
 655	int ret;
 656	u16 idx;
 657
 658	/* Initialize SMBus sequence fields */
 659	smbseq.ccode = pdev->iniccode | CCODE_EEPROM;
 660	smbseq.data = (u8 *)&eeseq;
 661
 662	/* Send data byte-by-byte, checking if it is successfully written */
 663	for (idx = 0; idx < len; idx++, memaddr++) {
 664		/* Lock IDT SMBus device */
 665		mutex_lock(&pdev->smb_mtx);
 666
 667		/* Perform write operation */
 668		smbseq.bytecnt = EEPROM_WR_CNT;
 669		eeseq.cmd = pdev->inieecmd | EEPROM_OP_WRITE;
 670		eeseq.eeaddr = pdev->eeaddr;
 671		eeseq.memaddr = cpu_to_le16(memaddr);
 672		eeseq.data = data[idx];
 673		ret = pdev->smb_write(pdev, &smbseq);
 674		if (ret != 0) {
 675			dev_err(dev,
 676				"Failed to write 0x%04hx:0x%02hhx to eeprom",
 677				memaddr, data[idx]);
 678			goto err_mutex_unlock;
 679		}
 680
 681		/*
 682		 * Check whether the data is successfully written by reading
 683		 * from the same EEPROM memory address.
 684		 */
 685		eeseq.data = ~data[idx];
 686		ret = idt_eeprom_read_byte(pdev, memaddr, &eeseq.data);
 687		if (ret != 0)
 688			goto err_mutex_unlock;
 689
 690		/* Check whether the read byte is the same as written one */
 691		if (eeseq.data != data[idx]) {
 692			dev_err(dev, "Values don't match 0x%02hhx != 0x%02hhx",
 693				eeseq.data, data[idx]);
 694			ret = -EREMOTEIO;
 695			goto err_mutex_unlock;
 696		}
 697
 698		/* Unlock IDT SMBus device */
 699err_mutex_unlock:
 700		mutex_unlock(&pdev->smb_mtx);
 701		if (ret != 0)
 702			return ret;
 703	}
 704
 705	return 0;
 706}
 707
 708/*
 709 * idt_eeprom_read() - EEPROM read operation
 710 * @pdev:	Pointer to the driver data
 711 * @memaddr:	Start EEPROM memory address
 712 * @len:	Length of data to read
 713 * @buf:	Buffer to read data to
 714 */
 715static int idt_eeprom_read(struct idt_89hpesx_dev *pdev, u16 memaddr, u16 len,
 716			   u8 *buf)
 717{
 718	int ret;
 719	u16 idx;
 720
 721	/* Read data byte-by-byte, retrying if it wasn't successful */
 722	for (idx = 0; idx < len; idx++, memaddr++) {
 723		/* Lock IDT SMBus device */
 724		mutex_lock(&pdev->smb_mtx);
 725
 726		/* Just read the byte to the buffer */
 727		ret = idt_eeprom_read_byte(pdev, memaddr, &buf[idx]);
 728
 729		/* Unlock IDT SMBus device */
 730		mutex_unlock(&pdev->smb_mtx);
 731
 732		/* Return error if read operation failed */
 733		if (ret != 0)
 734			return ret;
 735	}
 736
 737	return 0;
 738}
 739
 740/*===========================================================================
 741 *                          CSR IO-operations
 742 *===========================================================================
 743 */
 744
 745/*
 746 * idt_csr_write() - CSR write operation
 747 * @pdev:	Pointer to the driver data
 748 * @csraddr:	CSR address (with no two LS bits)
 749 * @data:	Data to be written to CSR
 750 */
 751static int idt_csr_write(struct idt_89hpesx_dev *pdev, u16 csraddr,
 752			 const u32 data)
 753{
 754	struct device *dev = &pdev->client->dev;
 755	struct idt_csr_seq csrseq;
 756	struct idt_smb_seq smbseq;
 757	int ret;
 758
 759	/* Initialize SMBus sequence fields */
 760	smbseq.ccode = pdev->iniccode | CCODE_CSR;
 761	smbseq.data = (u8 *)&csrseq;
 762
 763	/* Lock IDT SMBus device */
 764	mutex_lock(&pdev->smb_mtx);
 765
 766	/* Perform write operation */
 767	smbseq.bytecnt = CSR_WR_CNT;
 768	csrseq.cmd = pdev->inicsrcmd | CSR_OP_WRITE;
 769	csrseq.csraddr = cpu_to_le16(csraddr);
 770	csrseq.data = cpu_to_le32(data);
 771	ret = pdev->smb_write(pdev, &smbseq);
 772	if (ret != 0) {
 773		dev_err(dev, "Failed to write 0x%04x: 0x%04x to csr",
 774			CSR_REAL_ADDR(csraddr), data);
 775		goto err_mutex_unlock;
 776	}
 777
 778	/* Send CSR address to read data from */
 779	smbseq.bytecnt = CSR_WRRD_CNT;
 780	csrseq.cmd = pdev->inicsrcmd | CSR_OP_READ;
 781	ret = pdev->smb_write(pdev, &smbseq);
 782	if (ret != 0) {
 783		dev_err(dev, "Failed to init csr address 0x%04x",
 784			CSR_REAL_ADDR(csraddr));
 785		goto err_mutex_unlock;
 786	}
 787
 788	/* Perform read operation */
 789	smbseq.bytecnt = CSR_RD_CNT;
 790	ret = pdev->smb_read(pdev, &smbseq);
 791	if (ret != 0) {
 792		dev_err(dev, "Failed to read csr 0x%04x",
 793			CSR_REAL_ADDR(csraddr));
 794		goto err_mutex_unlock;
 795	}
 796
 797	/* Check whether IDT successfully retrieved CSR data */
 798	if (csrseq.cmd & (CSR_RERR | CSR_WERR)) {
 799		dev_err(dev, "IDT failed to perform CSR r/w");
 800		ret = -EREMOTEIO;
 801		goto err_mutex_unlock;
 802	}
 803
 804	/* Unlock IDT SMBus device */
 805err_mutex_unlock:
 806	mutex_unlock(&pdev->smb_mtx);
 807
 808	return ret;
 809}
 810
 811/*
 812 * idt_csr_read() - CSR read operation
 813 * @pdev:	Pointer to the driver data
 814 * @csraddr:	CSR address (with no two LS bits)
 815 * @data:	Data to be written to CSR
 816 */
 817static int idt_csr_read(struct idt_89hpesx_dev *pdev, u16 csraddr, u32 *data)
 818{
 819	struct device *dev = &pdev->client->dev;
 820	struct idt_csr_seq csrseq;
 821	struct idt_smb_seq smbseq;
 822	int ret;
 823
 824	/* Initialize SMBus sequence fields */
 825	smbseq.ccode = pdev->iniccode | CCODE_CSR;
 826	smbseq.data = (u8 *)&csrseq;
 827
 828	/* Lock IDT SMBus device */
 829	mutex_lock(&pdev->smb_mtx);
 830
 831	/* Send CSR register address before reading it */
 832	smbseq.bytecnt = CSR_WRRD_CNT;
 833	csrseq.cmd = pdev->inicsrcmd | CSR_OP_READ;
 834	csrseq.csraddr = cpu_to_le16(csraddr);
 835	ret = pdev->smb_write(pdev, &smbseq);
 836	if (ret != 0) {
 837		dev_err(dev, "Failed to init csr address 0x%04x",
 838			CSR_REAL_ADDR(csraddr));
 839		goto err_mutex_unlock;
 840	}
 841
 842	/* Perform read operation */
 843	smbseq.bytecnt = CSR_RD_CNT;
 844	ret = pdev->smb_read(pdev, &smbseq);
 845	if (ret != 0) {
 846		dev_err(dev, "Failed to read csr 0x%04hx",
 847			CSR_REAL_ADDR(csraddr));
 848		goto err_mutex_unlock;
 849	}
 850
 851	/* Check whether IDT successfully retrieved CSR data */
 852	if (csrseq.cmd & (CSR_RERR | CSR_WERR)) {
 853		dev_err(dev, "IDT failed to perform CSR r/w");
 854		ret = -EREMOTEIO;
 855		goto err_mutex_unlock;
 856	}
 857
 858	/* Save data retrieved from IDT */
 859	*data = le32_to_cpu(csrseq.data);
 860
 861	/* Unlock IDT SMBus device */
 862err_mutex_unlock:
 863	mutex_unlock(&pdev->smb_mtx);
 864
 865	return ret;
 866}
 867
 868/*===========================================================================
 869 *                          Sysfs/debugfs-nodes IO-operations
 870 *===========================================================================
 871 */
 872
 873/*
 874 * eeprom_write() - EEPROM sysfs-node write callback
 875 * @filep:	Pointer to the file system node
 876 * @kobj:	Pointer to the kernel object related to the sysfs-node
 877 * @attr:	Attributes of the file
 878 * @buf:	Buffer to write data to
 879 * @off:	Offset at which data should be written to
 880 * @count:	Number of bytes to write
 881 */
 882static ssize_t eeprom_write(struct file *filp, struct kobject *kobj,
 883			    struct bin_attribute *attr,
 884			    char *buf, loff_t off, size_t count)
 885{
 886	struct idt_89hpesx_dev *pdev;
 887	int ret;
 888
 889	/* Retrieve driver data */
 890	pdev = dev_get_drvdata(kobj_to_dev(kobj));
 891
 892	/* Perform EEPROM write operation */
 893	ret = idt_eeprom_write(pdev, (u16)off, (u16)count, (u8 *)buf);
 894	return (ret != 0 ? ret : count);
 895}
 896
 897/*
 898 * eeprom_read() - EEPROM sysfs-node read callback
 899 * @filep:	Pointer to the file system node
 900 * @kobj:	Pointer to the kernel object related to the sysfs-node
 901 * @attr:	Attributes of the file
 902 * @buf:	Buffer to write data to
 903 * @off:	Offset at which data should be written to
 904 * @count:	Number of bytes to write
 905 */
 906static ssize_t eeprom_read(struct file *filp, struct kobject *kobj,
 907			   struct bin_attribute *attr,
 908			   char *buf, loff_t off, size_t count)
 909{
 910	struct idt_89hpesx_dev *pdev;
 911	int ret;
 912
 913	/* Retrieve driver data */
 914	pdev = dev_get_drvdata(kobj_to_dev(kobj));
 915
 916	/* Perform EEPROM read operation */
 917	ret = idt_eeprom_read(pdev, (u16)off, (u16)count, (u8 *)buf);
 918	return (ret != 0 ? ret : count);
 919}
 920
 921/*
 922 * idt_dbgfs_csr_write() - CSR debugfs-node write callback
 923 * @filep:	Pointer to the file system file descriptor
 924 * @buf:	Buffer to read data from
 925 * @count:	Size of the buffer
 926 * @offp:	Offset within the file
 927 *
 928 * It accepts either "0x<reg addr>:0x<value>" for saving register address
 929 * and writing value to specified DWORD register or "0x<reg addr>" for
 930 * just saving register address in order to perform next read operation.
 931 *
 932 * WARNING No spaces are allowed. Incoming string must be strictly formated as:
 933 * "<reg addr>:<value>". Register address must be aligned within 4 bytes
 934 * (one DWORD).
 935 */
 936static ssize_t idt_dbgfs_csr_write(struct file *filep, const char __user *ubuf,
 937				   size_t count, loff_t *offp)
 938{
 939	struct idt_89hpesx_dev *pdev = filep->private_data;
 940	char *colon_ch, *csraddr_str, *csrval_str;
 941	int ret, csraddr_len, csrval_len;
 942	u32 csraddr, csrval;
 943	char *buf;
 944
 945	/* Copy data from User-space */
 946	buf = kmalloc(count + 1, GFP_KERNEL);
 947	if (!buf)
 948		return -ENOMEM;
 949
 950	ret = simple_write_to_buffer(buf, count, offp, ubuf, count);
 951	if (ret < 0)
 952		goto free_buf;
 953	buf[count] = 0;
 954
 955	/* Find position of colon in the buffer */
 956	colon_ch = strnchr(buf, count, ':');
 957
 958	/*
 959	 * If there is colon passed then new CSR value should be parsed as
 960	 * well, so allocate buffer for CSR address substring.
 961	 * If no colon is found, then string must have just one number with
 962	 * no new CSR value
 963	 */
 964	if (colon_ch != NULL) {
 965		csraddr_len = colon_ch - buf;
 966		csraddr_str =
 967			kmalloc(sizeof(char)*(csraddr_len + 1), GFP_KERNEL);
 968		if (csraddr_str == NULL) {
 969			ret = -ENOMEM;
 970			goto free_buf;
 971		}
 972		/* Copy the register address to the substring buffer */
 973		strncpy(csraddr_str, buf, csraddr_len);
 974		csraddr_str[csraddr_len] = '\0';
 975		/* Register value must follow the colon */
 976		csrval_str = colon_ch + 1;
 977		csrval_len = strnlen(csrval_str, count - csraddr_len);
 978	} else /* if (str_colon == NULL) */ {
 979		csraddr_str = (char *)buf; /* Just to shut warning up */
 980		csraddr_len = strnlen(csraddr_str, count);
 981		csrval_str = NULL;
 982		csrval_len = 0;
 983	}
 984
 985	/* Convert CSR address to u32 value */
 986	ret = kstrtou32(csraddr_str, 0, &csraddr);
 987	if (ret != 0)
 988		goto free_csraddr_str;
 989
 990	/* Check whether passed register address is valid */
 991	if (csraddr > CSR_MAX || !IS_ALIGNED(csraddr, SZ_4)) {
 992		ret = -EINVAL;
 993		goto free_csraddr_str;
 994	}
 995
 996	/* Shift register address to the right so to have u16 address */
 997	pdev->csr = (csraddr >> 2);
 998
 999	/* Parse new CSR value and send it to IDT, if colon has been found */
1000	if (colon_ch != NULL) {
1001		ret = kstrtou32(csrval_str, 0, &csrval);
1002		if (ret != 0)
1003			goto free_csraddr_str;
1004
1005		ret = idt_csr_write(pdev, pdev->csr, csrval);
1006		if (ret != 0)
1007			goto free_csraddr_str;
1008	}
1009
1010	/* Free memory only if colon has been found */
1011free_csraddr_str:
1012	if (colon_ch != NULL)
1013		kfree(csraddr_str);
1014
1015	/* Free buffer allocated for data retrieved from User-space */
1016free_buf:
1017	kfree(buf);
1018
1019	return (ret != 0 ? ret : count);
1020}
1021
1022/*
1023 * idt_dbgfs_csr_read() - CSR debugfs-node read callback
1024 * @filep:	Pointer to the file system file descriptor
1025 * @buf:	Buffer to write data to
1026 * @count:	Size of the buffer
1027 * @offp:	Offset within the file
1028 *
1029 * It just prints the pair "0x<reg addr>:0x<value>" to passed buffer.
1030 */
1031#define CSRBUF_SIZE	((size_t)32)
1032static ssize_t idt_dbgfs_csr_read(struct file *filep, char __user *ubuf,
1033				  size_t count, loff_t *offp)
1034{
1035	struct idt_89hpesx_dev *pdev = filep->private_data;
1036	u32 csraddr, csrval;
1037	char buf[CSRBUF_SIZE];
1038	int ret, size;
1039
1040	/* Perform CSR read operation */
1041	ret = idt_csr_read(pdev, pdev->csr, &csrval);
1042	if (ret != 0)
1043		return ret;
1044
1045	/* Shift register address to the left so to have real address */
1046	csraddr = ((u32)pdev->csr << 2);
1047
1048	/* Print the "0x<reg addr>:0x<value>" to buffer */
1049	size = snprintf(buf, CSRBUF_SIZE, "0x%05x:0x%08x\n",
1050		(unsigned int)csraddr, (unsigned int)csrval);
1051
1052	/* Copy data to User-space */
1053	return simple_read_from_buffer(ubuf, count, offp, buf, size);
1054}
1055
1056/*
1057 * eeprom_attribute - EEPROM sysfs-node attributes
1058 *
1059 * NOTE Size will be changed in compliance with OF node. EEPROM attribute will
1060 * be read-only as well if the corresponding flag is specified in OF node.
1061 */
1062static BIN_ATTR_RW(eeprom, EEPROM_DEF_SIZE);
1063
1064/*
1065 * csr_dbgfs_ops - CSR debugfs-node read/write operations
1066 */
1067static const struct file_operations csr_dbgfs_ops = {
1068	.owner = THIS_MODULE,
1069	.open = simple_open,
1070	.write = idt_dbgfs_csr_write,
1071	.read = idt_dbgfs_csr_read
1072};
1073
1074/*===========================================================================
1075 *                       Driver init/deinit methods
1076 *===========================================================================
1077 */
1078
1079/*
1080 * idt_set_defval() - disable EEPROM access by default
1081 * @pdev:	Pointer to the driver data
1082 */
1083static void idt_set_defval(struct idt_89hpesx_dev *pdev)
1084{
1085	/* If OF info is missing then use next values */
1086	pdev->eesize = 0;
1087	pdev->eero = true;
1088	pdev->inieecmd = 0;
1089	pdev->eeaddr = 0;
1090}
1091
1092static const struct i2c_device_id ee_ids[];
1093
1094/*
1095 * idt_ee_match_id() - check whether the node belongs to compatible EEPROMs
1096 */
1097static const struct i2c_device_id *idt_ee_match_id(struct fwnode_handle *fwnode)
1098{
1099	const struct i2c_device_id *id = ee_ids;
1100	const char *compatible, *p;
1101	char devname[I2C_NAME_SIZE];
1102	int ret;
1103
1104	ret = fwnode_property_read_string(fwnode, "compatible", &compatible);
1105	if (ret)
1106		return NULL;
1107
1108	p = strchr(compatible, ',');
1109	strlcpy(devname, p ? p + 1 : compatible, sizeof(devname));
1110	/* Search through the device name */
1111	while (id->name[0]) {
1112		if (strcmp(devname, id->name) == 0)
1113			return id;
1114		id++;
1115	}
1116	return NULL;
1117}
1118
1119/*
1120 * idt_get_fw_data() - get IDT i2c-device parameters from device tree
1121 * @pdev:	Pointer to the driver data
1122 */
1123static void idt_get_fw_data(struct idt_89hpesx_dev *pdev)
1124{
1125	struct device *dev = &pdev->client->dev;
1126	struct fwnode_handle *fwnode;
1127	const struct i2c_device_id *ee_id = NULL;
1128	u32 eeprom_addr;
1129	int ret;
1130
1131	device_for_each_child_node(dev, fwnode) {
1132		ee_id = idt_ee_match_id(fwnode);
1133		if (IS_ERR_OR_NULL(ee_id)) {
1134			dev_warn(dev, "Skip unsupported EEPROM device");
1135			continue;
1136		} else
1137			break;
1138	}
1139
1140	/* If there is no fwnode EEPROM device, then set zero size */
1141	if (!ee_id) {
1142		dev_warn(dev, "No fwnode, EEPROM access disabled");
1143		idt_set_defval(pdev);
1144		return;
1145	}
1146
1147	/* Retrieve EEPROM size */
1148	pdev->eesize = (u32)ee_id->driver_data;
1149
1150	/* Get custom EEPROM address from 'reg' attribute */
1151	ret = fwnode_property_read_u32(fwnode, "reg", &eeprom_addr);
1152	if (ret || (eeprom_addr == 0)) {
1153		dev_warn(dev, "No EEPROM reg found, use default address 0x%x",
1154			 EEPROM_DEF_ADDR);
1155		pdev->inieecmd = 0;
1156		pdev->eeaddr = EEPROM_DEF_ADDR << 1;
1157	} else {
1158		pdev->inieecmd = EEPROM_USA;
1159		pdev->eeaddr = eeprom_addr << 1;
1160	}
1161
1162	/* Check EEPROM 'read-only' flag */
1163	if (fwnode_property_read_bool(fwnode, "read-only"))
1164		pdev->eero = true;
1165	else /* if (!fwnode_property_read_bool(node, "read-only")) */
1166		pdev->eero = false;
1167
1168	dev_info(dev, "EEPROM of %d bytes found by 0x%x",
1169		pdev->eesize, pdev->eeaddr);
1170}
1171
1172/*
1173 * idt_create_pdev() - create and init data structure of the driver
1174 * @client:	i2c client of IDT PCIe-switch device
1175 */
1176static struct idt_89hpesx_dev *idt_create_pdev(struct i2c_client *client)
1177{
1178	struct idt_89hpesx_dev *pdev;
1179
1180	/* Allocate memory for driver data */
1181	pdev = devm_kmalloc(&client->dev, sizeof(struct idt_89hpesx_dev),
1182		GFP_KERNEL);
1183	if (pdev == NULL)
1184		return ERR_PTR(-ENOMEM);
1185
1186	/* Initialize basic fields of the data */
1187	pdev->client = client;
1188	i2c_set_clientdata(client, pdev);
1189
1190	/* Read firmware nodes information */
1191	idt_get_fw_data(pdev);
1192
1193	/* Initialize basic CSR CMD field - use full DWORD-sized r/w ops */
1194	pdev->inicsrcmd = CSR_DWE;
1195	pdev->csr = CSR_DEF;
1196
1197	/* Enable Packet Error Checking if it's supported by adapter */
1198	if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_PEC)) {
1199		pdev->iniccode = CCODE_PEC;
1200		client->flags |= I2C_CLIENT_PEC;
1201	} else /* PEC is unsupported */ {
1202		pdev->iniccode = 0;
1203	}
1204
1205	return pdev;
1206}
1207
1208/*
1209 * idt_free_pdev() - free data structure of the driver
1210 * @pdev:	Pointer to the driver data
1211 */
1212static void idt_free_pdev(struct idt_89hpesx_dev *pdev)
1213{
1214	/* Clear driver data from device private field */
1215	i2c_set_clientdata(pdev->client, NULL);
1216}
1217
1218/*
1219 * idt_set_smbus_ops() - set supported SMBus operations
1220 * @pdev:	Pointer to the driver data
1221 * Return status of smbus check operations
1222 */
1223static int idt_set_smbus_ops(struct idt_89hpesx_dev *pdev)
1224{
1225	struct i2c_adapter *adapter = pdev->client->adapter;
1226	struct device *dev = &pdev->client->dev;
1227
1228	/* Check i2c adapter read functionality */
1229	if (i2c_check_functionality(adapter,
1230				    I2C_FUNC_SMBUS_READ_BLOCK_DATA)) {
1231		pdev->smb_read = idt_smb_read_block;
1232		dev_dbg(dev, "SMBus block-read op chosen");
1233	} else if (i2c_check_functionality(adapter,
1234					   I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
1235		pdev->smb_read = idt_smb_read_i2c_block;
1236		dev_dbg(dev, "SMBus i2c-block-read op chosen");
1237	} else if (i2c_check_functionality(adapter,
1238					   I2C_FUNC_SMBUS_READ_WORD_DATA) &&
1239		   i2c_check_functionality(adapter,
1240					   I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
1241		pdev->smb_read = idt_smb_read_word;
1242		dev_warn(dev, "Use slow word/byte SMBus read ops");
1243	} else if (i2c_check_functionality(adapter,
1244					   I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
1245		pdev->smb_read = idt_smb_read_byte;
1246		dev_warn(dev, "Use slow byte SMBus read op");
1247	} else /* no supported smbus read operations */ {
1248		dev_err(dev, "No supported SMBus read op");
1249		return -EPFNOSUPPORT;
1250	}
1251
1252	/* Check i2c adapter write functionality */
1253	if (i2c_check_functionality(adapter,
1254				    I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)) {
1255		pdev->smb_write = idt_smb_write_block;
1256		dev_dbg(dev, "SMBus block-write op chosen");
1257	} else if (i2c_check_functionality(adapter,
1258					   I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)) {
1259		pdev->smb_write = idt_smb_write_i2c_block;
1260		dev_dbg(dev, "SMBus i2c-block-write op chosen");
1261	} else if (i2c_check_functionality(adapter,
1262					   I2C_FUNC_SMBUS_WRITE_WORD_DATA) &&
1263		   i2c_check_functionality(adapter,
1264					   I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) {
1265		pdev->smb_write = idt_smb_write_word;
1266		dev_warn(dev, "Use slow word/byte SMBus write op");
1267	} else if (i2c_check_functionality(adapter,
1268					   I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) {
1269		pdev->smb_write = idt_smb_write_byte;
1270		dev_warn(dev, "Use slow byte SMBus write op");
1271	} else /* no supported smbus write operations */ {
1272		dev_err(dev, "No supported SMBus write op");
1273		return -EPFNOSUPPORT;
1274	}
1275
1276	/* Initialize IDT SMBus slave interface mutex */
1277	mutex_init(&pdev->smb_mtx);
1278
1279	return 0;
1280}
1281
1282/*
1283 * idt_check_dev() - check whether it's really IDT 89HPESx device
1284 * @pdev:	Pointer to the driver data
1285 * Return status of i2c adapter check operation
1286 */
1287static int idt_check_dev(struct idt_89hpesx_dev *pdev)
1288{
1289	struct device *dev = &pdev->client->dev;
1290	u32 viddid;
1291	int ret;
1292
1293	/* Read VID and DID directly from IDT memory space */
1294	ret = idt_csr_read(pdev, IDT_VIDDID_CSR, &viddid);
1295	if (ret != 0) {
1296		dev_err(dev, "Failed to read VID/DID");
1297		return ret;
1298	}
1299
1300	/* Check whether it's IDT device */
1301	if ((viddid & IDT_VID_MASK) != PCI_VENDOR_ID_IDT) {
1302		dev_err(dev, "Got unsupported VID/DID: 0x%08x", viddid);
1303		return -ENODEV;
1304	}
1305
1306	dev_info(dev, "Found IDT 89HPES device VID:0x%04x, DID:0x%04x",
1307		(viddid & IDT_VID_MASK), (viddid >> 16));
1308
1309	return 0;
1310}
1311
1312/*
1313 * idt_create_sysfs_files() - create sysfs attribute files
1314 * @pdev:	Pointer to the driver data
1315 * Return status of operation
1316 */
1317static int idt_create_sysfs_files(struct idt_89hpesx_dev *pdev)
1318{
1319	struct device *dev = &pdev->client->dev;
1320	int ret;
1321
1322	/* Don't do anything if EEPROM isn't accessible */
1323	if (pdev->eesize == 0) {
1324		dev_dbg(dev, "Skip creating sysfs-files");
1325		return 0;
1326	}
1327
1328	/* Allocate memory for attribute file */
1329	pdev->ee_file = devm_kmalloc(dev, sizeof(*pdev->ee_file), GFP_KERNEL);
1330	if (!pdev->ee_file)
1331		return -ENOMEM;
1332
1333	/* Copy the declared EEPROM attr structure to change some of fields */
1334	memcpy(pdev->ee_file, &bin_attr_eeprom, sizeof(*pdev->ee_file));
1335
1336	/* In case of read-only EEPROM get rid of write ability */
1337	if (pdev->eero) {
1338		pdev->ee_file->attr.mode &= ~0200;
1339		pdev->ee_file->write = NULL;
1340	}
1341	/* Create EEPROM sysfs file */
1342	pdev->ee_file->size = pdev->eesize;
1343	ret = sysfs_create_bin_file(&dev->kobj, pdev->ee_file);
1344	if (ret != 0) {
1345		dev_err(dev, "Failed to create EEPROM sysfs-node");
1346		return ret;
1347	}
1348
1349	return 0;
1350}
1351
1352/*
1353 * idt_remove_sysfs_files() - remove sysfs attribute files
1354 * @pdev:	Pointer to the driver data
1355 */
1356static void idt_remove_sysfs_files(struct idt_89hpesx_dev *pdev)
1357{
1358	struct device *dev = &pdev->client->dev;
1359
1360	/* Don't do anything if EEPROM wasn't accessible */
1361	if (pdev->eesize == 0)
1362		return;
1363
1364	/* Remove EEPROM sysfs file */
1365	sysfs_remove_bin_file(&dev->kobj, pdev->ee_file);
1366}
1367
1368/*
1369 * idt_create_dbgfs_files() - create debugfs files
1370 * @pdev:	Pointer to the driver data
1371 */
1372#define CSRNAME_LEN	((size_t)32)
1373static void idt_create_dbgfs_files(struct idt_89hpesx_dev *pdev)
1374{
1375	struct i2c_client *cli = pdev->client;
1376	char fname[CSRNAME_LEN];
1377
1378	/* Create Debugfs directory for CSR file */
1379	snprintf(fname, CSRNAME_LEN, "%d-%04hx", cli->adapter->nr, cli->addr);
1380	pdev->csr_dir = debugfs_create_dir(fname, csr_dbgdir);
1381
1382	/* Create Debugfs file for CSR read/write operations */
1383	pdev->csr_file = debugfs_create_file(cli->name, 0600,
1384		pdev->csr_dir, pdev, &csr_dbgfs_ops);
1385}
1386
1387/*
1388 * idt_remove_dbgfs_files() - remove debugfs files
1389 * @pdev:	Pointer to the driver data
1390 */
1391static void idt_remove_dbgfs_files(struct idt_89hpesx_dev *pdev)
1392{
1393	/* Remove CSR directory and it sysfs-node */
1394	debugfs_remove_recursive(pdev->csr_dir);
1395}
1396
1397/*
1398 * idt_probe() - IDT 89HPESx driver probe() callback method
1399 */
1400static int idt_probe(struct i2c_client *client, const struct i2c_device_id *id)
1401{
1402	struct idt_89hpesx_dev *pdev;
1403	int ret;
1404
1405	/* Create driver data */
1406	pdev = idt_create_pdev(client);
1407	if (IS_ERR(pdev))
1408		return PTR_ERR(pdev);
1409
1410	/* Set SMBus operations */
1411	ret = idt_set_smbus_ops(pdev);
1412	if (ret != 0)
1413		goto err_free_pdev;
1414
1415	/* Check whether it is truly IDT 89HPESx device */
1416	ret = idt_check_dev(pdev);
1417	if (ret != 0)
1418		goto err_free_pdev;
1419
1420	/* Create sysfs files */
1421	ret = idt_create_sysfs_files(pdev);
1422	if (ret != 0)
1423		goto err_free_pdev;
1424
1425	/* Create debugfs files */
1426	idt_create_dbgfs_files(pdev);
1427
1428	return 0;
1429
1430err_free_pdev:
1431	idt_free_pdev(pdev);
1432
1433	return ret;
1434}
1435
1436/*
1437 * idt_remove() - IDT 89HPESx driver remove() callback method
1438 */
1439static int idt_remove(struct i2c_client *client)
1440{
1441	struct idt_89hpesx_dev *pdev = i2c_get_clientdata(client);
1442
1443	/* Remove debugfs files first */
1444	idt_remove_dbgfs_files(pdev);
1445
1446	/* Remove sysfs files */
1447	idt_remove_sysfs_files(pdev);
1448
1449	/* Discard driver data structure */
1450	idt_free_pdev(pdev);
1451
1452	return 0;
1453}
1454
1455/*
1456 * ee_ids - array of supported EEPROMs
1457 */
1458static const struct i2c_device_id ee_ids[] = {
1459	{ "24c32",  4096},
1460	{ "24c64",  8192},
1461	{ "24c128", 16384},
1462	{ "24c256", 32768},
1463	{ "24c512", 65536},
1464	{}
1465};
1466MODULE_DEVICE_TABLE(i2c, ee_ids);
1467
1468/*
1469 * idt_ids - supported IDT 89HPESx devices
1470 */
1471static const struct i2c_device_id idt_ids[] = {
1472	{ "89hpes8nt2", 0 },
1473	{ "89hpes12nt3", 0 },
1474
1475	{ "89hpes24nt6ag2", 0 },
1476	{ "89hpes32nt8ag2", 0 },
1477	{ "89hpes32nt8bg2", 0 },
1478	{ "89hpes12nt12g2", 0 },
1479	{ "89hpes16nt16g2", 0 },
1480	{ "89hpes24nt24g2", 0 },
1481	{ "89hpes32nt24ag2", 0 },
1482	{ "89hpes32nt24bg2", 0 },
1483
1484	{ "89hpes12n3", 0 },
1485	{ "89hpes12n3a", 0 },
1486	{ "89hpes24n3", 0 },
1487	{ "89hpes24n3a", 0 },
1488
1489	{ "89hpes32h8", 0 },
1490	{ "89hpes32h8g2", 0 },
1491	{ "89hpes48h12", 0 },
1492	{ "89hpes48h12g2", 0 },
1493	{ "89hpes48h12ag2", 0 },
1494	{ "89hpes16h16", 0 },
1495	{ "89hpes22h16", 0 },
1496	{ "89hpes22h16g2", 0 },
1497	{ "89hpes34h16", 0 },
1498	{ "89hpes34h16g2", 0 },
1499	{ "89hpes64h16", 0 },
1500	{ "89hpes64h16g2", 0 },
1501	{ "89hpes64h16ag2", 0 },
1502
1503	/* { "89hpes3t3", 0 }, // No SMBus-slave iface */
1504	{ "89hpes12t3g2", 0 },
1505	{ "89hpes24t3g2", 0 },
1506	/* { "89hpes4t4", 0 }, // No SMBus-slave iface */
1507	{ "89hpes16t4", 0 },
1508	{ "89hpes4t4g2", 0 },
1509	{ "89hpes10t4g2", 0 },
1510	{ "89hpes16t4g2", 0 },
1511	{ "89hpes16t4ag2", 0 },
1512	{ "89hpes5t5", 0 },
1513	{ "89hpes6t5", 0 },
1514	{ "89hpes8t5", 0 },
1515	{ "89hpes8t5a", 0 },
1516	{ "89hpes24t6", 0 },
1517	{ "89hpes6t6g2", 0 },
1518	{ "89hpes24t6g2", 0 },
1519	{ "89hpes16t7", 0 },
1520	{ "89hpes32t8", 0 },
1521	{ "89hpes32t8g2", 0 },
1522	{ "89hpes48t12", 0 },
1523	{ "89hpes48t12g2", 0 },
1524	{ /* END OF LIST */ }
1525};
1526MODULE_DEVICE_TABLE(i2c, idt_ids);
1527
1528static const struct of_device_id idt_of_match[] = {
1529	{ .compatible = "idt,89hpes8nt2", },
1530	{ .compatible = "idt,89hpes12nt3", },
1531
1532	{ .compatible = "idt,89hpes24nt6ag2", },
1533	{ .compatible = "idt,89hpes32nt8ag2", },
1534	{ .compatible = "idt,89hpes32nt8bg2", },
1535	{ .compatible = "idt,89hpes12nt12g2", },
1536	{ .compatible = "idt,89hpes16nt16g2", },
1537	{ .compatible = "idt,89hpes24nt24g2", },
1538	{ .compatible = "idt,89hpes32nt24ag2", },
1539	{ .compatible = "idt,89hpes32nt24bg2", },
1540
1541	{ .compatible = "idt,89hpes12n3", },
1542	{ .compatible = "idt,89hpes12n3a", },
1543	{ .compatible = "idt,89hpes24n3", },
1544	{ .compatible = "idt,89hpes24n3a", },
1545
1546	{ .compatible = "idt,89hpes32h8", },
1547	{ .compatible = "idt,89hpes32h8g2", },
1548	{ .compatible = "idt,89hpes48h12", },
1549	{ .compatible = "idt,89hpes48h12g2", },
1550	{ .compatible = "idt,89hpes48h12ag2", },
1551	{ .compatible = "idt,89hpes16h16", },
1552	{ .compatible = "idt,89hpes22h16", },
1553	{ .compatible = "idt,89hpes22h16g2", },
1554	{ .compatible = "idt,89hpes34h16", },
1555	{ .compatible = "idt,89hpes34h16g2", },
1556	{ .compatible = "idt,89hpes64h16", },
1557	{ .compatible = "idt,89hpes64h16g2", },
1558	{ .compatible = "idt,89hpes64h16ag2", },
1559
1560	{ .compatible = "idt,89hpes12t3g2", },
1561	{ .compatible = "idt,89hpes24t3g2", },
1562
1563	{ .compatible = "idt,89hpes16t4", },
1564	{ .compatible = "idt,89hpes4t4g2", },
1565	{ .compatible = "idt,89hpes10t4g2", },
1566	{ .compatible = "idt,89hpes16t4g2", },
1567	{ .compatible = "idt,89hpes16t4ag2", },
1568	{ .compatible = "idt,89hpes5t5", },
1569	{ .compatible = "idt,89hpes6t5", },
1570	{ .compatible = "idt,89hpes8t5", },
1571	{ .compatible = "idt,89hpes8t5a", },
1572	{ .compatible = "idt,89hpes24t6", },
1573	{ .compatible = "idt,89hpes6t6g2", },
1574	{ .compatible = "idt,89hpes24t6g2", },
1575	{ .compatible = "idt,89hpes16t7", },
1576	{ .compatible = "idt,89hpes32t8", },
1577	{ .compatible = "idt,89hpes32t8g2", },
1578	{ .compatible = "idt,89hpes48t12", },
1579	{ .compatible = "idt,89hpes48t12g2", },
1580	{ },
1581};
1582MODULE_DEVICE_TABLE(of, idt_of_match);
1583
1584/*
1585 * idt_driver - IDT 89HPESx driver structure
1586 */
1587static struct i2c_driver idt_driver = {
1588	.driver = {
1589		.name = IDT_NAME,
1590		.of_match_table = idt_of_match,
1591	},
1592	.probe = idt_probe,
1593	.remove = idt_remove,
1594	.id_table = idt_ids,
1595};
1596
1597/*
1598 * idt_init() - IDT 89HPESx driver init() callback method
1599 */
1600static int __init idt_init(void)
1601{
1602	/* Create Debugfs directory first */
1603	if (debugfs_initialized())
1604		csr_dbgdir = debugfs_create_dir("idt_csr", NULL);
1605
1606	/* Add new i2c-device driver */
1607	return i2c_add_driver(&idt_driver);
1608}
1609module_init(idt_init);
1610
1611/*
1612 * idt_exit() - IDT 89HPESx driver exit() callback method
1613 */
1614static void __exit idt_exit(void)
1615{
1616	/* Discard debugfs directory and all files if any */
1617	debugfs_remove_recursive(csr_dbgdir);
1618
1619	/* Unregister i2c-device driver */
1620	i2c_del_driver(&idt_driver);
1621}
1622module_exit(idt_exit);