1/*
2 *   This file is provided under a GPLv2 license.  When using or
3 *   redistributing this file, you may do so under that license.
4 *
5 *   GPL LICENSE SUMMARY
6 *
7 *   Copyright (C) 2016 T-Platforms. All Rights Reserved.
8 *
9 *   This program is free software; you can redistribute it and/or modify it
10 *   under the terms and conditions of the GNU General Public License,
11 *   version 2, as published by the Free Software Foundation.
12 *
13 *   This program is distributed in the hope that it will be useful, but WITHOUT
14 *   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 *   FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
16 *   more details.
17 *
18 *   You should have received a copy of the GNU General Public License along
19 *   with this program; if not, it can be found <http://www.gnu.org/licenses/>.
20 *
21 *   The full GNU General Public License is included in this distribution in
22 *   the file called "COPYING".
23 *
24 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
25 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
26 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
27 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
28 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
29 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
30 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
34 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 *
36 * IDT PCIe-switch NTB Linux driver
37 *
38 * Contact Information:
39 * Serge Semin <fancer.lancer@gmail.com>, <Sergey.Semin@t-platforms.ru>
40 */
41/*
42 *           NOTE of the IDT 89HPESx SMBus-slave interface driver
43 *    This driver primarily is developed to have an access to EEPROM device of
44 * IDT PCIe-switches. IDT provides a simple SMBus interface to perform IO-
45 * operations from/to EEPROM, which is located at private (so called Master)
46 * SMBus of switches. Using that interface this the driver creates a simple
47 * binary sysfs-file in the device directory:
48 * /sys/bus/i2c/devices/<bus>-<devaddr>/eeprom
49 * In case if read-only flag is specified in the dts-node of device desription,
50 * User-space applications won't be able to write to the EEPROM sysfs-node.
51 *    Additionally IDT 89HPESx SMBus interface has an ability to write/read
52 * data of device CSRs. This driver exposes debugf-file to perform simple IO
53 * operations using that ability for just basic debug purpose. Particularly
54 * next file is created in the specific debugfs-directory:
55 * /sys/kernel/debug/idt_csr/
56 * Format of the debugfs-node is:
57 * $ cat /sys/kernel/debug/idt_csr/<bus>-<devaddr>/<devname>;
58 * <CSR address>:<CSR value>
59 * So reading the content of the file gives current CSR address and it value.
60 * If User-space application wishes to change current CSR address,
61 * it can just write a proper value to the sysfs-file:
62 * $ echo "<CSR address>" > /sys/kernel/debug/idt_csr/<bus>-<devaddr>/<devname>
63 * If it wants to change the CSR value as well, the format of the write
64 * operation is:
65 * $ echo "<CSR address>:<CSR value>" > \
66 *        /sys/kernel/debug/idt_csr/<bus>-<devaddr>/<devname>;
67 * CSR address and value can be any of hexadecimal, decimal or octal format.
68 */
69
70#include <linux/kernel.h>
71#include <linux/init.h>
72#include <linux/module.h>
73#include <linux/types.h>
74#include <linux/sizes.h>
75#include <linux/slab.h>
76#include <linux/mutex.h>
77#include <linux/sysfs.h>
78#include <linux/debugfs.h>
79#include <linux/mod_devicetable.h>
80#include <linux/property.h>
81#include <linux/i2c.h>
82#include <linux/pci_ids.h>
83#include <linux/delay.h>
84
85#define IDT_NAME		"89hpesx"
86#define IDT_89HPESX_DESC	"IDT 89HPESx SMBus-slave interface driver"
87#define IDT_89HPESX_VER		"1.0"
88
89MODULE_DESCRIPTION(IDT_89HPESX_DESC);
90MODULE_VERSION(IDT_89HPESX_VER);
91MODULE_LICENSE("GPL v2");
92MODULE_AUTHOR("T-platforms");
93
94/*
95 * csr_dbgdir - CSR read/write operations Debugfs directory
96 */
97static struct dentry *csr_dbgdir;
98
99/*
100 * struct idt_89hpesx_dev - IDT 89HPESx device data structure
101 * @eesize:	Size of EEPROM in bytes (calculated from "idt,eecompatible")
102 * @eero:	EEPROM Read-only flag
103 * @eeaddr:	EEPROM custom address
104 *
105 * @inieecmd:	Initial cmd value for EEPROM read/write operations
106 * @inicsrcmd:	Initial cmd value for CSR read/write operations
107 * @iniccode:	Initialial command code value for IO-operations
108 *
109 * @csr:	CSR address to perform read operation
110 *
111 * @smb_write:	SMBus write method
112 * @smb_read:	SMBus read method
113 * @smb_mtx:	SMBus mutex
114 *
115 * @client:	i2c client used to perform IO operations
116 *
117 * @ee_file:	EEPROM read/write sysfs-file
118 */
119struct idt_smb_seq;
120struct idt_89hpesx_dev {
121	u32 eesize;
122	bool eero;
123	u8 eeaddr;
124
125	u8 inieecmd;
126	u8 inicsrcmd;
127	u8 iniccode;
128
129	u16 csr;
130
131	int (*smb_write)(struct idt_89hpesx_dev *, const struct idt_smb_seq *);
132	int (*smb_read)(struct idt_89hpesx_dev *, struct idt_smb_seq *);
133	struct mutex smb_mtx;
134
135	struct i2c_client *client;
136
137	struct bin_attribute *ee_file;
138	struct dentry *csr_dir;
139};
140
141/*
142 * struct idt_smb_seq - sequence of data to be read/written from/to IDT 89HPESx
143 * @ccode:	SMBus command code
144 * @bytecnt:	Byte count of operation
145 * @data:	Data to by written
146 */
147struct idt_smb_seq {
148	u8 ccode;
149	u8 bytecnt;
150	u8 *data;
151};
152
153/*
154 * struct idt_eeprom_seq - sequence of data to be read/written from/to EEPROM
155 * @cmd:	Transaction CMD
156 * @eeaddr:	EEPROM custom address
157 * @memaddr:	Internal memory address of EEPROM
158 * @data:	Data to be written at the memory address
159 */
160struct idt_eeprom_seq {
161	u8 cmd;
162	u8 eeaddr;
163	u16 memaddr;
164	u8 data;
165} __packed;
166
167/*
168 * struct idt_csr_seq - sequence of data to be read/written from/to CSR
169 * @cmd:	Transaction CMD
170 * @csraddr:	Internal IDT device CSR address
171 * @data:	Data to be read/written from/to the CSR address
172 */
173struct idt_csr_seq {
174	u8 cmd;
175	u16 csraddr;
176	u32 data;
177} __packed;
178
179/*
180 * SMBus command code macros
181 * @CCODE_END:		Indicates the end of transaction
182 * @CCODE_START:	Indicates the start of transaction
183 * @CCODE_CSR:		CSR read/write transaction
184 * @CCODE_EEPROM:	EEPROM read/write transaction
185 * @CCODE_BYTE:		Supplied data has BYTE length
186 * @CCODE_WORD:		Supplied data has WORD length
187 * @CCODE_BLOCK:	Supplied data has variable length passed in bytecnt
188 *			byte right following CCODE byte
189 */
190#define CCODE_END	((u8)0x01)
191#define CCODE_START	((u8)0x02)
192#define CCODE_CSR	((u8)0x00)
193#define CCODE_EEPROM	((u8)0x04)
194#define CCODE_BYTE	((u8)0x00)
195#define CCODE_WORD	((u8)0x20)
196#define CCODE_BLOCK	((u8)0x40)
197#define CCODE_PEC	((u8)0x80)
198
199/*
200 * EEPROM command macros
201 * @EEPROM_OP_WRITE:	EEPROM write operation
202 * @EEPROM_OP_READ:	EEPROM read operation
203 * @EEPROM_USA:		Use specified address of EEPROM
204 * @EEPROM_NAERR:	EEPROM device is not ready to respond
205 * @EEPROM_LAERR:	EEPROM arbitration loss error
206 * @EEPROM_MSS:		EEPROM misplace start & stop bits error
207 * @EEPROM_WR_CNT:	Bytes count to perform write operation
208 * @EEPROM_WRRD_CNT:	Bytes count to write before reading
209 * @EEPROM_RD_CNT:	Bytes count to perform read operation
210 * @EEPROM_DEF_SIZE:	Fall back size of EEPROM
211 * @EEPROM_DEF_ADDR:	Defatul EEPROM address
212 * @EEPROM_TOUT:	Timeout before retry read operation if eeprom is busy
213 */
214#define EEPROM_OP_WRITE	((u8)0x00)
215#define EEPROM_OP_READ	((u8)0x01)
216#define EEPROM_USA	((u8)0x02)
217#define EEPROM_NAERR	((u8)0x08)
218#define EEPROM_LAERR    ((u8)0x10)
219#define EEPROM_MSS	((u8)0x20)
220#define EEPROM_WR_CNT	((u8)5)
221#define EEPROM_WRRD_CNT	((u8)4)
222#define EEPROM_RD_CNT	((u8)5)
223#define EEPROM_DEF_SIZE	((u16)4096)
224#define EEPROM_DEF_ADDR	((u8)0x50)
225#define EEPROM_TOUT	(100)
226
227/*
228 * CSR command macros
229 * @CSR_DWE:		Enable all four bytes of the operation
230 * @CSR_OP_WRITE:	CSR write operation
231 * @CSR_OP_READ:	CSR read operation
232 * @CSR_RERR:		Read operation error
233 * @CSR_WERR:		Write operation error
234 * @CSR_WR_CNT:		Bytes count to perform write operation
235 * @CSR_WRRD_CNT:	Bytes count to write before reading
236 * @CSR_RD_CNT:		Bytes count to perform read operation
237 * @CSR_MAX:		Maximum CSR address
238 * @CSR_DEF:		Default CSR address
239 * @CSR_REAL_ADDR:	CSR real unshifted address
240 */
241#define CSR_DWE			((u8)0x0F)
242#define CSR_OP_WRITE		((u8)0x00)
243#define CSR_OP_READ		((u8)0x10)
244#define CSR_RERR		((u8)0x40)
245#define CSR_WERR		((u8)0x80)
246#define CSR_WR_CNT		((u8)7)
247#define CSR_WRRD_CNT		((u8)3)
248#define CSR_RD_CNT		((u8)7)
249#define CSR_MAX			((u32)0x3FFFF)
250#define CSR_DEF			((u16)0x0000)
251#define CSR_REAL_ADDR(val)	((unsigned int)val << 2)
252
253/*
254 * IDT 89HPESx basic register
255 * @IDT_VIDDID_CSR:	PCIe VID and DID of IDT 89HPESx
256 * @IDT_VID_MASK:	Mask of VID
257 */
258#define IDT_VIDDID_CSR	((u32)0x0000)
259#define IDT_VID_MASK	((u32)0xFFFF)
260
261/*
262 * IDT 89HPESx can send NACK when new command is sent before previous one
263 * fininshed execution. In this case driver retries operation
264 * certain times.
265 * @RETRY_CNT:		Number of retries before giving up and fail
266 * @idt_smb_safe:	Generate a retry loop on corresponding SMBus method
267 */
268#define RETRY_CNT (128)
269#define idt_smb_safe(ops, args...) ({ \
270	int __retry = RETRY_CNT; \
271	s32 __sts; \
272	do { \
273		__sts = i2c_smbus_ ## ops ## _data(args); \
274	} while (__retry-- && __sts < 0); \
275	__sts; \
276})
277
278/*===========================================================================
279 *                         i2c bus level IO-operations
280 *===========================================================================
281 */
282
283/*
284 * idt_smb_write_byte() - SMBus write method when I2C_SMBUS_BYTE_DATA operation
285 *                        is only available
286 * @pdev:	Pointer to the driver data
287 * @seq:	Sequence of data to be written
288 */
289static int idt_smb_write_byte(struct idt_89hpesx_dev *pdev,
290			      const struct idt_smb_seq *seq)
291{
292	s32 sts;
293	u8 ccode;
294	int idx;
295
296	/* Loop over the supplied data sending byte one-by-one */
297	for (idx = 0; idx < seq->bytecnt; idx++) {
298		/* Collect the command code byte */
299		ccode = seq->ccode | CCODE_BYTE;
300		if (idx == 0)
301			ccode |= CCODE_START;
302		if (idx == seq->bytecnt - 1)
303			ccode |= CCODE_END;
304
305		/* Send data to the device */
306		sts = idt_smb_safe(write_byte, pdev->client, ccode,
307			seq->data[idx]);
308		if (sts != 0)
309			return (int)sts;
310	}
311
312	return 0;
313}
314
315/*
316 * idt_smb_read_byte() - SMBus read method when I2C_SMBUS_BYTE_DATA operation
317 *                        is only available
318 * @pdev:	Pointer to the driver data
319 * @seq:	Buffer to read data to
320 */
321static int idt_smb_read_byte(struct idt_89hpesx_dev *pdev,
322			     struct idt_smb_seq *seq)
323{
324	s32 sts;
325	u8 ccode;
326	int idx;
327
328	/* Loop over the supplied buffer receiving byte one-by-one */
329	for (idx = 0; idx < seq->bytecnt; idx++) {
330		/* Collect the command code byte */
331		ccode = seq->ccode | CCODE_BYTE;
332		if (idx == 0)
333			ccode |= CCODE_START;
334		if (idx == seq->bytecnt - 1)
335			ccode |= CCODE_END;
336
337		/* Read data from the device */
338		sts = idt_smb_safe(read_byte, pdev->client, ccode);
339		if (sts < 0)
340			return (int)sts;
341
342		seq->data[idx] = (u8)sts;
343	}
344
345	return 0;
346}
347
348/*
349 * idt_smb_write_word() - SMBus write method when I2C_SMBUS_BYTE_DATA and
350 *                        I2C_FUNC_SMBUS_WORD_DATA operations are available
351 * @pdev:	Pointer to the driver data
352 * @seq:	Sequence of data to be written
353 */
354static int idt_smb_write_word(struct idt_89hpesx_dev *pdev,
355			      const struct idt_smb_seq *seq)
356{
357	s32 sts;
358	u8 ccode;
359	int idx, evencnt;
360
361	/* Calculate the even count of data to send */
362	evencnt = seq->bytecnt - (seq->bytecnt % 2);
363
364	/* Loop over the supplied data sending two bytes at a time */
365	for (idx = 0; idx < evencnt; idx += 2) {
366		/* Collect the command code byte */
367		ccode = seq->ccode | CCODE_WORD;
368		if (idx == 0)
369			ccode |= CCODE_START;
370		if (idx == evencnt - 2)
371			ccode |= CCODE_END;
372
373		/* Send word data to the device */
374		sts = idt_smb_safe(write_word, pdev->client, ccode,
375			*(u16 *)&seq->data[idx]);
376		if (sts != 0)
377			return (int)sts;
378	}
379
380	/* If there is odd number of bytes then send just one last byte */
381	if (seq->bytecnt != evencnt) {
382		/* Collect the command code byte */
383		ccode = seq->ccode | CCODE_BYTE | CCODE_END;
384		if (idx == 0)
385			ccode |= CCODE_START;
386
387		/* Send byte data to the device */
388		sts = idt_smb_safe(write_byte, pdev->client, ccode,
389			seq->data[idx]);
390		if (sts != 0)
391			return (int)sts;
392	}
393
394	return 0;
395}
396
397/*
398 * idt_smb_read_word() - SMBus read method when I2C_SMBUS_BYTE_DATA and
399 *                       I2C_FUNC_SMBUS_WORD_DATA operations are available
400 * @pdev:	Pointer to the driver data
401 * @seq:	Buffer to read data to
402 */
403static int idt_smb_read_word(struct idt_89hpesx_dev *pdev,
404			     struct idt_smb_seq *seq)
405{
406	s32 sts;
407	u8 ccode;
408	int idx, evencnt;
409
410	/* Calculate the even count of data to send */
411	evencnt = seq->bytecnt - (seq->bytecnt % 2);
412
413	/* Loop over the supplied data reading two bytes at a time */
414	for (idx = 0; idx < evencnt; idx += 2) {
415		/* Collect the command code byte */
416		ccode = seq->ccode | CCODE_WORD;
417		if (idx == 0)
418			ccode |= CCODE_START;
419		if (idx == evencnt - 2)
420			ccode |= CCODE_END;
421
422		/* Read word data from the device */
423		sts = idt_smb_safe(read_word, pdev->client, ccode);
424		if (sts < 0)
425			return (int)sts;
426
427		*(u16 *)&seq->data[idx] = (u16)sts;
428	}
429
430	/* If there is odd number of bytes then receive just one last byte */
431	if (seq->bytecnt != evencnt) {
432		/* Collect the command code byte */
433		ccode = seq->ccode | CCODE_BYTE | CCODE_END;
434		if (idx == 0)
435			ccode |= CCODE_START;
436
437		/* Read last data byte from the device */
438		sts = idt_smb_safe(read_byte, pdev->client, ccode);
439		if (sts < 0)
440			return (int)sts;
441
442		seq->data[idx] = (u8)sts;
443	}
444
445	return 0;
446}
447
448/*
449 * idt_smb_write_block() - SMBus write method when I2C_SMBUS_BLOCK_DATA
450 *                         operation is available
451 * @pdev:	Pointer to the driver data
452 * @seq:	Sequence of data to be written
453 */
454static int idt_smb_write_block(struct idt_89hpesx_dev *pdev,
455			       const struct idt_smb_seq *seq)
456{
457	u8 ccode;
458
459	/* Return error if too much data passed to send */
460	if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX)
461		return -EINVAL;
462
463	/* Collect the command code byte */
464	ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END;
465
466	/* Send block of data to the device */
467	return idt_smb_safe(write_block, pdev->client, ccode, seq->bytecnt,
468		seq->data);
469}
470
471/*
472 * idt_smb_read_block() - SMBus read method when I2C_SMBUS_BLOCK_DATA
473 *                        operation is available
474 * @pdev:	Pointer to the driver data
475 * @seq:	Buffer to read data to
476 */
477static int idt_smb_read_block(struct idt_89hpesx_dev *pdev,
478			      struct idt_smb_seq *seq)
479{
480	s32 sts;
481	u8 ccode;
482
483	/* Return error if too much data passed to send */
484	if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX)
485		return -EINVAL;
486
487	/* Collect the command code byte */
488	ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END;
489
490	/* Read block of data from the device */
491	sts = idt_smb_safe(read_block, pdev->client, ccode, seq->data);
492	if (sts != seq->bytecnt)
493		return (sts < 0 ? sts : -ENODATA);
494
495	return 0;
496}
497
498/*
499 * idt_smb_write_i2c_block() - SMBus write method when I2C_SMBUS_I2C_BLOCK_DATA
500 *                             operation is available
501 * @pdev:	Pointer to the driver data
502 * @seq:	Sequence of data to be written
503 *
504 * NOTE It's usual SMBus write block operation, except the actual data length is
505 * sent as first byte of data
506 */
507static int idt_smb_write_i2c_block(struct idt_89hpesx_dev *pdev,
508				   const struct idt_smb_seq *seq)
509{
510	u8 ccode, buf[I2C_SMBUS_BLOCK_MAX + 1];
511
512	/* Return error if too much data passed to send */
513	if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX)
514		return -EINVAL;
515
516	/* Collect the data to send. Length byte must be added prior the data */
517	buf[0] = seq->bytecnt;
518	memcpy(&buf[1], seq->data, seq->bytecnt);
519
520	/* Collect the command code byte */
521	ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END;
522
523	/* Send length and block of data to the device */
524	return idt_smb_safe(write_i2c_block, pdev->client, ccode,
525		seq->bytecnt + 1, buf);
526}
527
528/*
529 * idt_smb_read_i2c_block() - SMBus read method when I2C_SMBUS_I2C_BLOCK_DATA
530 *                            operation is available
531 * @pdev:	Pointer to the driver data
532 * @seq:	Buffer to read data to
533 *
534 * NOTE It's usual SMBus read block operation, except the actual data length is
535 * retrieved as first byte of data
536 */
537static int idt_smb_read_i2c_block(struct idt_89hpesx_dev *pdev,
538				  struct idt_smb_seq *seq)
539{
540	u8 ccode, buf[I2C_SMBUS_BLOCK_MAX + 1];
541	s32 sts;
542
543	/* Return error if too much data passed to send */
544	if (seq->bytecnt > I2C_SMBUS_BLOCK_MAX)
545		return -EINVAL;
546
547	/* Collect the command code byte */
548	ccode = seq->ccode | CCODE_BLOCK | CCODE_START | CCODE_END;
549
550	/* Read length and block of data from the device */
551	sts = idt_smb_safe(read_i2c_block, pdev->client, ccode,
552		seq->bytecnt + 1, buf);
553	if (sts != seq->bytecnt + 1)
554		return (sts < 0 ? sts : -ENODATA);
555	if (buf[0] != seq->bytecnt)
556		return -ENODATA;
557
558	/* Copy retrieved data to the output data buffer */
559	memcpy(seq->data, &buf[1], seq->bytecnt);
560
561	return 0;
562}
563
564/*===========================================================================
565 *                          EEPROM IO-operations
566 *===========================================================================
567 */
568
569/*
570 * idt_eeprom_read_byte() - read just one byte from EEPROM
571 * @pdev:	Pointer to the driver data
572 * @memaddr:	Start EEPROM memory address
573 * @data:	Data to be written to EEPROM
574 */
575static int idt_eeprom_read_byte(struct idt_89hpesx_dev *pdev, u16 memaddr,
576				u8 *data)
577{
578	struct device *dev = &pdev->client->dev;
579	struct idt_eeprom_seq eeseq;
580	struct idt_smb_seq smbseq;
581	int ret, retry;
582
583	/* Initialize SMBus sequence fields */
584	smbseq.ccode = pdev->iniccode | CCODE_EEPROM;
585	smbseq.data = (u8 *)&eeseq;
586
587	/*
588	 * Sometimes EEPROM may respond with NACK if it's busy with previous
589	 * operation, so we need to perform a few attempts of read cycle
590	 */
591	retry = RETRY_CNT;
592	do {
593		/* Send EEPROM memory address to read data from */
594		smbseq.bytecnt = EEPROM_WRRD_CNT;
595		eeseq.cmd = pdev->inieecmd | EEPROM_OP_READ;
596		eeseq.eeaddr = pdev->eeaddr;
597		eeseq.memaddr = cpu_to_le16(memaddr);
598		ret = pdev->smb_write(pdev, &smbseq);
599		if (ret != 0) {
600			dev_err(dev, "Failed to init eeprom addr 0x%02hhx",
601				memaddr);
602			break;
603		}
604
605		/* Perform read operation */
606		smbseq.bytecnt = EEPROM_RD_CNT;
607		ret = pdev->smb_read(pdev, &smbseq);
608		if (ret != 0) {
609			dev_err(dev, "Failed to read eeprom data 0x%02hhx",
610				memaddr);
611			break;
612		}
613
614		/* Restart read operation if the device is busy */
615		if (retry && (eeseq.cmd & EEPROM_NAERR)) {
616			dev_dbg(dev, "EEPROM busy, retry reading after %d ms",
617				EEPROM_TOUT);
618			msleep(EEPROM_TOUT);
619			continue;
620		}
621
622		/* Check whether IDT successfully read data from EEPROM */
623		if (eeseq.cmd & (EEPROM_NAERR | EEPROM_LAERR | EEPROM_MSS)) {
624			dev_err(dev,
625				"Communication with eeprom failed, cmd 0x%hhx",
626				eeseq.cmd);
627			ret = -EREMOTEIO;
628			break;
629		}
630
631		/* Save retrieved data and exit the loop */
632		*data = eeseq.data;
633		break;
634	} while (retry--);
635
636	/* Return the status of operation */
637	return ret;
638}
639
640/*
641 * idt_eeprom_write() - EEPROM write operation
642 * @pdev:	Pointer to the driver data
643 * @memaddr:	Start EEPROM memory address
644 * @len:	Length of data to be written
645 * @data:	Data to be written to EEPROM
646 */
647static int idt_eeprom_write(struct idt_89hpesx_dev *pdev, u16 memaddr, u16 len,
648			    const u8 *data)
649{
650	struct device *dev = &pdev->client->dev;
651	struct idt_eeprom_seq eeseq;
652	struct idt_smb_seq smbseq;
653	int ret;
654	u16 idx;
655
656	/* Initialize SMBus sequence fields */
657	smbseq.ccode = pdev->iniccode | CCODE_EEPROM;
658	smbseq.data = (u8 *)&eeseq;
659
660	/* Send data byte-by-byte, checking if it is successfully written */
661	for (idx = 0; idx < len; idx++, memaddr++) {
662		/* Lock IDT SMBus device */
663		mutex_lock(&pdev->smb_mtx);
664
665		/* Perform write operation */
666		smbseq.bytecnt = EEPROM_WR_CNT;
667		eeseq.cmd = pdev->inieecmd | EEPROM_OP_WRITE;
668		eeseq.eeaddr = pdev->eeaddr;
669		eeseq.memaddr = cpu_to_le16(memaddr);
670		eeseq.data = data[idx];
671		ret = pdev->smb_write(pdev, &smbseq);
672		if (ret != 0) {
673			dev_err(dev,
674				"Failed to write 0x%04hx:0x%02hhx to eeprom",
675				memaddr, data[idx]);
676			goto err_mutex_unlock;
677		}
678
679		/*
680		 * Check whether the data is successfully written by reading
681		 * from the same EEPROM memory address.
682		 */
683		eeseq.data = ~data[idx];
684		ret = idt_eeprom_read_byte(pdev, memaddr, &eeseq.data);
685		if (ret != 0)
686			goto err_mutex_unlock;
687
688		/* Check whether the read byte is the same as written one */
689		if (eeseq.data != data[idx]) {
690			dev_err(dev, "Values don't match 0x%02hhx != 0x%02hhx",
691				eeseq.data, data[idx]);
692			ret = -EREMOTEIO;
693			goto err_mutex_unlock;
694		}
695
696		/* Unlock IDT SMBus device */
697err_mutex_unlock:
698		mutex_unlock(&pdev->smb_mtx);
699		if (ret != 0)
700			return ret;
701	}
702
703	return 0;
704}
705
706/*
707 * idt_eeprom_read() - EEPROM read operation
708 * @pdev:	Pointer to the driver data
709 * @memaddr:	Start EEPROM memory address
710 * @len:	Length of data to read
711 * @buf:	Buffer to read data to
712 */
713static int idt_eeprom_read(struct idt_89hpesx_dev *pdev, u16 memaddr, u16 len,
714			   u8 *buf)
715{
716	int ret;
717	u16 idx;
718
719	/* Read data byte-by-byte, retrying if it wasn't successful */
720	for (idx = 0; idx < len; idx++, memaddr++) {
721		/* Lock IDT SMBus device */
722		mutex_lock(&pdev->smb_mtx);
723
724		/* Just read the byte to the buffer */
725		ret = idt_eeprom_read_byte(pdev, memaddr, &buf[idx]);
726
727		/* Unlock IDT SMBus device */
728		mutex_unlock(&pdev->smb_mtx);
729
730		/* Return error if read operation failed */
731		if (ret != 0)
732			return ret;
733	}
734
735	return 0;
736}
737
738/*===========================================================================
739 *                          CSR IO-operations
740 *===========================================================================
741 */
742
743/*
744 * idt_csr_write() - CSR write operation
745 * @pdev:	Pointer to the driver data
746 * @csraddr:	CSR address (with no two LS bits)
747 * @data:	Data to be written to CSR
748 */
749static int idt_csr_write(struct idt_89hpesx_dev *pdev, u16 csraddr,
750			 const u32 data)
751{
752	struct device *dev = &pdev->client->dev;
753	struct idt_csr_seq csrseq;
754	struct idt_smb_seq smbseq;
755	int ret;
756
757	/* Initialize SMBus sequence fields */
758	smbseq.ccode = pdev->iniccode | CCODE_CSR;
759	smbseq.data = (u8 *)&csrseq;
760
761	/* Lock IDT SMBus device */
762	mutex_lock(&pdev->smb_mtx);
763
764	/* Perform write operation */
765	smbseq.bytecnt = CSR_WR_CNT;
766	csrseq.cmd = pdev->inicsrcmd | CSR_OP_WRITE;
767	csrseq.csraddr = cpu_to_le16(csraddr);
768	csrseq.data = cpu_to_le32(data);
769	ret = pdev->smb_write(pdev, &smbseq);
770	if (ret != 0) {
771		dev_err(dev, "Failed to write 0x%04x: 0x%04x to csr",
772			CSR_REAL_ADDR(csraddr), data);
773		goto err_mutex_unlock;
774	}
775
776	/* Send CSR address to read data from */
777	smbseq.bytecnt = CSR_WRRD_CNT;
778	csrseq.cmd = pdev->inicsrcmd | CSR_OP_READ;
779	ret = pdev->smb_write(pdev, &smbseq);
780	if (ret != 0) {
781		dev_err(dev, "Failed to init csr address 0x%04x",
782			CSR_REAL_ADDR(csraddr));
783		goto err_mutex_unlock;
784	}
785
786	/* Perform read operation */
787	smbseq.bytecnt = CSR_RD_CNT;
788	ret = pdev->smb_read(pdev, &smbseq);
789	if (ret != 0) {
790		dev_err(dev, "Failed to read csr 0x%04x",
791			CSR_REAL_ADDR(csraddr));
792		goto err_mutex_unlock;
793	}
794
795	/* Check whether IDT successfully retrieved CSR data */
796	if (csrseq.cmd & (CSR_RERR | CSR_WERR)) {
797		dev_err(dev, "IDT failed to perform CSR r/w");
798		ret = -EREMOTEIO;
799		goto err_mutex_unlock;
800	}
801
802	/* Unlock IDT SMBus device */
803err_mutex_unlock:
804	mutex_unlock(&pdev->smb_mtx);
805
806	return ret;
807}
808
809/*
810 * idt_csr_read() - CSR read operation
811 * @pdev:	Pointer to the driver data
812 * @csraddr:	CSR address (with no two LS bits)
813 * @data:	Data to be written to CSR
814 */
815static int idt_csr_read(struct idt_89hpesx_dev *pdev, u16 csraddr, u32 *data)
816{
817	struct device *dev = &pdev->client->dev;
818	struct idt_csr_seq csrseq;
819	struct idt_smb_seq smbseq;
820	int ret;
821
822	/* Initialize SMBus sequence fields */
823	smbseq.ccode = pdev->iniccode | CCODE_CSR;
824	smbseq.data = (u8 *)&csrseq;
825
826	/* Lock IDT SMBus device */
827	mutex_lock(&pdev->smb_mtx);
828
829	/* Send CSR register address before reading it */
830	smbseq.bytecnt = CSR_WRRD_CNT;
831	csrseq.cmd = pdev->inicsrcmd | CSR_OP_READ;
832	csrseq.csraddr = cpu_to_le16(csraddr);
833	ret = pdev->smb_write(pdev, &smbseq);
834	if (ret != 0) {
835		dev_err(dev, "Failed to init csr address 0x%04x",
836			CSR_REAL_ADDR(csraddr));
837		goto err_mutex_unlock;
838	}
839
840	/* Perform read operation */
841	smbseq.bytecnt = CSR_RD_CNT;
842	ret = pdev->smb_read(pdev, &smbseq);
843	if (ret != 0) {
844		dev_err(dev, "Failed to read csr 0x%04hx",
845			CSR_REAL_ADDR(csraddr));
846		goto err_mutex_unlock;
847	}
848
849	/* Check whether IDT successfully retrieved CSR data */
850	if (csrseq.cmd & (CSR_RERR | CSR_WERR)) {
851		dev_err(dev, "IDT failed to perform CSR r/w");
852		ret = -EREMOTEIO;
853		goto err_mutex_unlock;
854	}
855
856	/* Save data retrieved from IDT */
857	*data = le32_to_cpu(csrseq.data);
858
859	/* Unlock IDT SMBus device */
860err_mutex_unlock:
861	mutex_unlock(&pdev->smb_mtx);
862
863	return ret;
864}
865
866/*===========================================================================
867 *                          Sysfs/debugfs-nodes IO-operations
868 *===========================================================================
869 */
870
871/*
872 * eeprom_write() - EEPROM sysfs-node write callback
873 * @filep:	Pointer to the file system node
874 * @kobj:	Pointer to the kernel object related to the sysfs-node
875 * @attr:	Attributes of the file
876 * @buf:	Buffer to write data to
877 * @off:	Offset at which data should be written to
878 * @count:	Number of bytes to write
879 */
880static ssize_t eeprom_write(struct file *filp, struct kobject *kobj,
881			    struct bin_attribute *attr,
882			    char *buf, loff_t off, size_t count)
883{
884	struct idt_89hpesx_dev *pdev;
885	int ret;
886
887	/* Retrieve driver data */
888	pdev = dev_get_drvdata(kobj_to_dev(kobj));
889
890	/* Perform EEPROM write operation */
891	ret = idt_eeprom_write(pdev, (u16)off, (u16)count, (u8 *)buf);
892	return (ret != 0 ? ret : count);
893}
894
895/*
896 * eeprom_read() - EEPROM sysfs-node read callback
897 * @filep:	Pointer to the file system node
898 * @kobj:	Pointer to the kernel object related to the sysfs-node
899 * @attr:	Attributes of the file
900 * @buf:	Buffer to write data to
901 * @off:	Offset at which data should be written to
902 * @count:	Number of bytes to write
903 */
904static ssize_t eeprom_read(struct file *filp, struct kobject *kobj,
905			   struct bin_attribute *attr,
906			   char *buf, loff_t off, size_t count)
907{
908	struct idt_89hpesx_dev *pdev;
909	int ret;
910
911	/* Retrieve driver data */
912	pdev = dev_get_drvdata(kobj_to_dev(kobj));
913
914	/* Perform EEPROM read operation */
915	ret = idt_eeprom_read(pdev, (u16)off, (u16)count, (u8 *)buf);
916	return (ret != 0 ? ret : count);
917}
918
919/*
920 * idt_dbgfs_csr_write() - CSR debugfs-node write callback
921 * @filep:	Pointer to the file system file descriptor
922 * @buf:	Buffer to read data from
923 * @count:	Size of the buffer
924 * @offp:	Offset within the file
925 *
926 * It accepts either "0x<reg addr>:0x<value>" for saving register address
927 * and writing value to specified DWORD register or "0x<reg addr>" for
928 * just saving register address in order to perform next read operation.
929 *
930 * WARNING No spaces are allowed. Incoming string must be strictly formated as:
931 * "<reg addr>:<value>". Register address must be aligned within 4 bytes
932 * (one DWORD).
933 */
934static ssize_t idt_dbgfs_csr_write(struct file *filep, const char __user *ubuf,
935				   size_t count, loff_t *offp)
936{
937	struct idt_89hpesx_dev *pdev = filep->private_data;
938	char *colon_ch, *csraddr_str, *csrval_str;
939	int ret, csraddr_len;
940	u32 csraddr, csrval;
941	char *buf;
942
943	if (*offp)
944		return 0;
945
946	/* Copy data from User-space */
947	buf = kmalloc(count + 1, GFP_KERNEL);
948	if (!buf)
949		return -ENOMEM;
950
951	if (copy_from_user(buf, ubuf, count)) {
952		ret = -EFAULT;
953		goto free_buf;
954	}
955	buf[count] = 0;
956
957	/* Find position of colon in the buffer */
958	colon_ch = strnchr(buf, count, ':');
959
960	/*
961	 * If there is colon passed then new CSR value should be parsed as
962	 * well, so allocate buffer for CSR address substring.
963	 * If no colon is found, then string must have just one number with
964	 * no new CSR value
965	 */
966	if (colon_ch != NULL) {
967		csraddr_len = colon_ch - buf;
968		csraddr_str =
969			kmalloc(csraddr_len + 1, GFP_KERNEL);
970		if (csraddr_str == NULL) {
971			ret = -ENOMEM;
972			goto free_buf;
973		}
974		/* Copy the register address to the substring buffer */
975		strncpy(csraddr_str, buf, csraddr_len);
976		csraddr_str[csraddr_len] = '\0';
977		/* Register value must follow the colon */
978		csrval_str = colon_ch + 1;
979	} else /* if (str_colon == NULL) */ {
980		csraddr_str = (char *)buf; /* Just to shut warning up */
981		csraddr_len = strnlen(csraddr_str, count);
982		csrval_str = NULL;
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 (ee_id)
1134			break;
1135
1136		dev_warn(dev, "Skip unsupported EEPROM device %pfw\n", fwnode);
1137	}
1138
1139	/* If there is no fwnode EEPROM device, then set zero size */
1140	if (!ee_id) {
1141		dev_warn(dev, "No fwnode, EEPROM access disabled");
1142		idt_set_defval(pdev);
1143		return;
1144	}
1145
1146	/* Retrieve EEPROM size */
1147	pdev->eesize = (u32)ee_id->driver_data;
1148
1149	/* Get custom EEPROM address from 'reg' attribute */
1150	ret = fwnode_property_read_u32(fwnode, "reg", &eeprom_addr);
1151	if (ret || (eeprom_addr == 0)) {
1152		dev_warn(dev, "No EEPROM reg found, use default address 0x%x",
1153			 EEPROM_DEF_ADDR);
1154		pdev->inieecmd = 0;
1155		pdev->eeaddr = EEPROM_DEF_ADDR << 1;
1156	} else {
1157		pdev->inieecmd = EEPROM_USA;
1158		pdev->eeaddr = eeprom_addr << 1;
1159	}
1160
1161	/* Check EEPROM 'read-only' flag */
1162	if (fwnode_property_read_bool(fwnode, "read-only"))
1163		pdev->eero = true;
1164	else /* if (!fwnode_property_read_bool(node, "read-only")) */
1165		pdev->eero = false;
1166
1167	fwnode_handle_put(fwnode);
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	debugfs_create_file(cli->name, 0600, pdev->csr_dir, pdev,
1384			    &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);
1623