summaryrefslogtreecommitdiff
path: root/drivers/i2c/busses/i2c-pnx.c
blob: f448505d54682779fd8269415512512424a25d34 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
/*
 * Provides I2C support for Philips PNX010x/PNX4008 boards.
 *
 * Authors: Dennis Kovalev <dkovalev@ru.mvista.com>
 *	    Vitaly Wool <vwool@ru.mvista.com>
 *
 * 2004-2006 (c) MontaVista Software, Inc. This file is licensed under
 * the terms of the GNU General Public License version 2. This program
 * is licensed "as is" without any warranty of any kind, whether express
 * or implied.
 */

#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/completion.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/slab.h>
#include <linux/of.h>

#define I2C_PNX_TIMEOUT_DEFAULT		10 /* msec */
#define I2C_PNX_SPEED_KHZ_DEFAULT	100
#define I2C_PNX_REGION_SIZE		0x100

struct i2c_pnx_mif {
	int			ret;		/* Return value */
	int			mode;		/* Interface mode */
	struct completion	complete;	/* I/O completion */
	u8 *			buf;		/* Data buffer */
	int			len;		/* Length of data buffer */
	int			order;		/* RX Bytes to order via TX */
};

struct i2c_pnx_algo_data {
	void __iomem		*ioaddr;
	struct i2c_pnx_mif	mif;
	int			last;
	struct clk		*clk;
	struct i2c_adapter	adapter;
	int			irq;
	u32			timeout;
};

enum {
	mstatus_tdi = 0x00000001,
	mstatus_afi = 0x00000002,
	mstatus_nai = 0x00000004,
	mstatus_drmi = 0x00000008,
	mstatus_active = 0x00000020,
	mstatus_scl = 0x00000040,
	mstatus_sda = 0x00000080,
	mstatus_rff = 0x00000100,
	mstatus_rfe = 0x00000200,
	mstatus_tff = 0x00000400,
	mstatus_tfe = 0x00000800,
};

enum {
	mcntrl_tdie = 0x00000001,
	mcntrl_afie = 0x00000002,
	mcntrl_naie = 0x00000004,
	mcntrl_drmie = 0x00000008,
	mcntrl_drsie = 0x00000010,
	mcntrl_rffie = 0x00000020,
	mcntrl_daie = 0x00000040,
	mcntrl_tffie = 0x00000080,
	mcntrl_reset = 0x00000100,
	mcntrl_cdbmode = 0x00000400,
};

enum {
	rw_bit = 1 << 0,
	start_bit = 1 << 8,
	stop_bit = 1 << 9,
};

#define I2C_REG_RX(a)	((a)->ioaddr)		/* Rx FIFO reg (RO) */
#define I2C_REG_TX(a)	((a)->ioaddr)		/* Tx FIFO reg (WO) */
#define I2C_REG_STS(a)	((a)->ioaddr + 0x04)	/* Status reg (RO) */
#define I2C_REG_CTL(a)	((a)->ioaddr + 0x08)	/* Ctl reg */
#define I2C_REG_CKL(a)	((a)->ioaddr + 0x0c)	/* Clock divider low */
#define I2C_REG_CKH(a)	((a)->ioaddr + 0x10)	/* Clock divider high */
#define I2C_REG_ADR(a)	((a)->ioaddr + 0x14)	/* I2C address */
#define I2C_REG_RFL(a)	((a)->ioaddr + 0x18)	/* Rx FIFO level (RO) */
#define I2C_REG_TFL(a)	((a)->ioaddr + 0x1c)	/* Tx FIFO level (RO) */
#define I2C_REG_RXB(a)	((a)->ioaddr + 0x20)	/* Num of bytes Rx-ed (RO) */
#define I2C_REG_TXB(a)	((a)->ioaddr + 0x24)	/* Num of bytes Tx-ed (RO) */
#define I2C_REG_TXS(a)	((a)->ioaddr + 0x28)	/* Tx slave FIFO (RO) */
#define I2C_REG_STFL(a)	((a)->ioaddr + 0x2c)	/* Tx slave FIFO level (RO) */

static inline int wait_timeout(struct i2c_pnx_algo_data *data)
{
	long timeout = data->timeout;
	while (timeout > 0 &&
			(ioread32(I2C_REG_STS(data)) & mstatus_active)) {
		mdelay(1);
		timeout--;
	}
	return (timeout <= 0);
}

static inline int wait_reset(struct i2c_pnx_algo_data *data)
{
	long timeout = data->timeout;
	while (timeout > 0 &&
			(ioread32(I2C_REG_CTL(data)) & mcntrl_reset)) {
		mdelay(1);
		timeout--;
	}
	return (timeout <= 0);
}

/**
 * i2c_pnx_start - start a device
 * @slave_addr:		slave address
 * @alg_data:		pointer to local driver data structure
 *
 * Generate a START signal in the desired mode.
 */
static int i2c_pnx_start(unsigned char slave_addr,
	struct i2c_pnx_algo_data *alg_data)
{
	dev_dbg(&alg_data->adapter.dev, "%s(): addr 0x%x mode %d\n", __func__,
		slave_addr, alg_data->mif.mode);

	/* Check for 7 bit slave addresses only */
	if (slave_addr & ~0x7f) {
		dev_err(&alg_data->adapter.dev,
			"%s: Invalid slave address %x. Only 7-bit addresses are supported\n",
			alg_data->adapter.name, slave_addr);
		return -EINVAL;
	}

	/* First, make sure bus is idle */
	if (wait_timeout(alg_data)) {
		/* Somebody else is monopolizing the bus */
		dev_err(&alg_data->adapter.dev,
			"%s: Bus busy. Slave addr = %02x, cntrl = %x, stat = %x\n",
			alg_data->adapter.name, slave_addr,
			ioread32(I2C_REG_CTL(alg_data)),
			ioread32(I2C_REG_STS(alg_data)));
		return -EBUSY;
	} else if (ioread32(I2C_REG_STS(alg_data)) & mstatus_afi) {
		/* Sorry, we lost the bus */
		dev_err(&alg_data->adapter.dev,
		        "%s: Arbitration failure. Slave addr = %02x\n",
			alg_data->adapter.name, slave_addr);
		return -EIO;
	}

	/*
	 * OK, I2C is enabled and we have the bus.
	 * Clear the current TDI and AFI status flags.
	 */
	iowrite32(ioread32(I2C_REG_STS(alg_data)) | mstatus_tdi | mstatus_afi,
		  I2C_REG_STS(alg_data));

	dev_dbg(&alg_data->adapter.dev, "%s(): sending %#x\n", __func__,
		(slave_addr << 1) | start_bit | alg_data->mif.mode);

	/* Write the slave address, START bit and R/W bit */
	iowrite32((slave_addr << 1) | start_bit | alg_data->mif.mode,
		  I2C_REG_TX(alg_data));

	dev_dbg(&alg_data->adapter.dev, "%s(): exit\n", __func__);

	return 0;
}

/**
 * i2c_pnx_stop - stop a device
 * @alg_data:		pointer to local driver data structure
 *
 * Generate a STOP signal to terminate the master transaction.
 */
static void i2c_pnx_stop(struct i2c_pnx_algo_data *alg_data)
{
	/* Only 1 msec max timeout due to interrupt context */
	long timeout = 1000;

	dev_dbg(&alg_data->adapter.dev, "%s(): entering: stat = %04x.\n",
		__func__, ioread32(I2C_REG_STS(alg_data)));

	/* Write a STOP bit to TX FIFO */
	iowrite32(0xff | stop_bit, I2C_REG_TX(alg_data));

	/* Wait until the STOP is seen. */
	while (timeout > 0 &&
	       (ioread32(I2C_REG_STS(alg_data)) & mstatus_active)) {
		/* may be called from interrupt context */
		udelay(1);
		timeout--;
	}

	dev_dbg(&alg_data->adapter.dev, "%s(): exiting: stat = %04x.\n",
		__func__, ioread32(I2C_REG_STS(alg_data)));
}

/**
 * i2c_pnx_master_xmit - transmit data to slave
 * @alg_data:		pointer to local driver data structure
 *
 * Sends one byte of data to the slave
 */
static int i2c_pnx_master_xmit(struct i2c_pnx_algo_data *alg_data)
{
	u32 val;

	dev_dbg(&alg_data->adapter.dev, "%s(): entering: stat = %04x.\n",
		__func__, ioread32(I2C_REG_STS(alg_data)));

	if (alg_data->mif.len > 0) {
		/* We still have something to talk about... */
		val = *alg_data->mif.buf++;

		if (alg_data->mif.len == 1)
			val |= stop_bit;

		alg_data->mif.len--;
		iowrite32(val, I2C_REG_TX(alg_data));

		dev_dbg(&alg_data->adapter.dev, "%s(): xmit %#x [%d]\n",
			__func__, val, alg_data->mif.len + 1);

		if (alg_data->mif.len == 0) {
			if (alg_data->last) {
				/* Wait until the STOP is seen. */
				if (wait_timeout(alg_data))
					dev_err(&alg_data->adapter.dev,
						"The bus is still active after timeout\n");
			}
			/* Disable master interrupts */
			iowrite32(ioread32(I2C_REG_CTL(alg_data)) &
				~(mcntrl_afie | mcntrl_naie | mcntrl_drmie),
				  I2C_REG_CTL(alg_data));

			dev_dbg(&alg_data->adapter.dev,
				"%s(): Waking up xfer routine.\n",
				__func__);

			complete(&alg_data->mif.complete);
		}
	} else if (alg_data->mif.len == 0) {
		/* zero-sized transfer */
		i2c_pnx_stop(alg_data);

		/* Disable master interrupts. */
		iowrite32(ioread32(I2C_REG_CTL(alg_data)) &
			~(mcntrl_afie | mcntrl_naie | mcntrl_drmie),
			  I2C_REG_CTL(alg_data));

		dev_dbg(&alg_data->adapter.dev,
			"%s(): Waking up xfer routine after zero-xfer.\n",
			__func__);

		complete(&alg_data->mif.complete);
	}

	dev_dbg(&alg_data->adapter.dev, "%s(): exiting: stat = %04x.\n",
		__func__, ioread32(I2C_REG_STS(alg_data)));

	return 0;
}

/**
 * i2c_pnx_master_rcv - receive data from slave
 * @alg_data:		pointer to local driver data structure
 *
 * Reads one byte data from the slave
 */
static int i2c_pnx_master_rcv(struct i2c_pnx_algo_data *alg_data)
{
	unsigned int val = 0;
	u32 ctl = 0;

	dev_dbg(&alg_data->adapter.dev, "%s(): entering: stat = %04x.\n",
		__func__, ioread32(I2C_REG_STS(alg_data)));

	/* Check, whether there is already data,
	 * or we didn't 'ask' for it yet.
	 */
	if (ioread32(I2C_REG_STS(alg_data)) & mstatus_rfe) {
		/* 'Asking' is done asynchronously, e.g. dummy TX of several
		 * bytes is done before the first actual RX arrives in FIFO.
		 * Therefore, ordered bytes (via TX) are counted separately.
		 */
		if (alg_data->mif.order) {
			dev_dbg(&alg_data->adapter.dev,
				"%s(): Write dummy data to fill Rx-fifo...\n",
				__func__);

			if (alg_data->mif.order == 1) {
				/* Last byte, do not acknowledge next rcv. */
				val |= stop_bit;

				/*
				 * Enable interrupt RFDAIE (data in Rx fifo),
				 * and disable DRMIE (need data for Tx)
				 */
				ctl = ioread32(I2C_REG_CTL(alg_data));
				ctl |= mcntrl_rffie | mcntrl_daie;
				ctl &= ~mcntrl_drmie;
				iowrite32(ctl, I2C_REG_CTL(alg_data));
			}

			/*
			 * Now we'll 'ask' for data:
			 * For each byte we want to receive, we must
			 * write a (dummy) byte to the Tx-FIFO.
			 */
			iowrite32(val, I2C_REG_TX(alg_data));
			alg_data->mif.order--;
		}
		return 0;
	}

	/* Handle data. */
	if (alg_data->mif.len > 0) {
		val = ioread32(I2C_REG_RX(alg_data));
		*alg_data->mif.buf++ = (u8) (val & 0xff);
		dev_dbg(&alg_data->adapter.dev, "%s(): rcv 0x%x [%d]\n",
			__func__, val, alg_data->mif.len);

		alg_data->mif.len--;
		if (alg_data->mif.len == 0) {
			if (alg_data->last)
				/* Wait until the STOP is seen. */
				if (wait_timeout(alg_data))
					dev_err(&alg_data->adapter.dev,
						"The bus is still active after timeout\n");

			/* Disable master interrupts */
			ctl = ioread32(I2C_REG_CTL(alg_data));
			ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie |
				 mcntrl_drmie | mcntrl_daie);
			iowrite32(ctl, I2C_REG_CTL(alg_data));

			complete(&alg_data->mif.complete);
		}
	}

	dev_dbg(&alg_data->adapter.dev, "%s(): exiting: stat = %04x.\n",
		__func__, ioread32(I2C_REG_STS(alg_data)));

	return 0;
}

static irqreturn_t i2c_pnx_interrupt(int irq, void *dev_id)
{
	struct i2c_pnx_algo_data *alg_data = dev_id;
	u32 stat, ctl;

	dev_dbg(&alg_data->adapter.dev,
		"%s(): mstat = %x mctrl = %x, mode = %d\n",
		__func__,
		ioread32(I2C_REG_STS(alg_data)),
		ioread32(I2C_REG_CTL(alg_data)),
		alg_data->mif.mode);
	stat = ioread32(I2C_REG_STS(alg_data));

	/* let's see what kind of event this is */
	if (stat & mstatus_afi) {
		/* We lost arbitration in the midst of a transfer */
		alg_data->mif.ret = -EIO;

		/* Disable master interrupts. */
		ctl = ioread32(I2C_REG_CTL(alg_data));
		ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie |
			 mcntrl_drmie);
		iowrite32(ctl, I2C_REG_CTL(alg_data));

		complete(&alg_data->mif.complete);
	} else if (stat & mstatus_nai) {
		/* Slave did not acknowledge, generate a STOP */
		dev_dbg(&alg_data->adapter.dev,
			"%s(): Slave did not acknowledge, generating a STOP.\n",
			__func__);
		i2c_pnx_stop(alg_data);

		/* Disable master interrupts. */
		ctl = ioread32(I2C_REG_CTL(alg_data));
		ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie |
			 mcntrl_drmie);
		iowrite32(ctl, I2C_REG_CTL(alg_data));

		/* Our return value. */
		alg_data->mif.ret = -EIO;

		complete(&alg_data->mif.complete);
	} else {
		/*
		 * Two options:
		 * - Master Tx needs data.
		 * - There is data in the Rx-fifo
		 * The latter is only the case if we have requested for data,
		 * via a dummy write. (See 'i2c_pnx_master_rcv'.)
		 * We therefore check, as a sanity check, whether that interrupt
		 * has been enabled.
		 */
		if ((stat & mstatus_drmi) || !(stat & mstatus_rfe)) {
			if (alg_data->mif.mode == I2C_SMBUS_WRITE) {
				i2c_pnx_master_xmit(alg_data);
			} else if (alg_data->mif.mode == I2C_SMBUS_READ) {
				i2c_pnx_master_rcv(alg_data);
			}
		}
	}

	/* Clear TDI and AFI bits */
	stat = ioread32(I2C_REG_STS(alg_data));
	iowrite32(stat | mstatus_tdi | mstatus_afi, I2C_REG_STS(alg_data));

	dev_dbg(&alg_data->adapter.dev,
		"%s(): exiting, stat = %x ctrl = %x.\n",
		 __func__, ioread32(I2C_REG_STS(alg_data)),
		 ioread32(I2C_REG_CTL(alg_data)));

	return IRQ_HANDLED;
}

static void i2c_pnx_timeout(struct i2c_pnx_algo_data *alg_data)
{
	u32 ctl;

	dev_err(&alg_data->adapter.dev,
		"Master timed out. stat = %04x, cntrl = %04x. Resetting master...\n",
		ioread32(I2C_REG_STS(alg_data)),
		ioread32(I2C_REG_CTL(alg_data)));

	/* Reset master and disable interrupts */
	ctl = ioread32(I2C_REG_CTL(alg_data));
	ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie | mcntrl_drmie);
	iowrite32(ctl, I2C_REG_CTL(alg_data));

	ctl |= mcntrl_reset;
	iowrite32(ctl, I2C_REG_CTL(alg_data));
	wait_reset(alg_data);
	alg_data->mif.ret = -EIO;
}

static inline void bus_reset_if_active(struct i2c_pnx_algo_data *alg_data)
{
	u32 stat;

	if ((stat = ioread32(I2C_REG_STS(alg_data))) & mstatus_active) {
		dev_err(&alg_data->adapter.dev,
			"%s: Bus is still active after xfer. Reset it...\n",
			alg_data->adapter.name);
		iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
			  I2C_REG_CTL(alg_data));
		wait_reset(alg_data);
	} else if (!(stat & mstatus_rfe) || !(stat & mstatus_tfe)) {
		/* If there is data in the fifo's after transfer,
		 * flush fifo's by reset.
		 */
		iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
			  I2C_REG_CTL(alg_data));
		wait_reset(alg_data);
	} else if (stat & mstatus_nai) {
		iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
			  I2C_REG_CTL(alg_data));
		wait_reset(alg_data);
	}
}

/**
 * i2c_pnx_xfer - generic transfer entry point
 * @adap:		pointer to I2C adapter structure
 * @msgs:		array of messages
 * @num:		number of messages
 *
 * Initiates the transfer
 */
static int
i2c_pnx_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
{
	struct i2c_msg *pmsg;
	int rc = 0, completed = 0, i;
	struct i2c_pnx_algo_data *alg_data = adap->algo_data;
	unsigned long time_left;
	u32 stat;

	dev_dbg(&alg_data->adapter.dev,
		"%s(): entering: %d messages, stat = %04x.\n",
		__func__, num, ioread32(I2C_REG_STS(alg_data)));

	bus_reset_if_active(alg_data);

	/* Process transactions in a loop. */
	for (i = 0; rc >= 0 && i < num; i++) {
		u8 addr;

		pmsg = &msgs[i];
		addr = pmsg->addr;

		if (pmsg->flags & I2C_M_TEN) {
			dev_err(&alg_data->adapter.dev,
				"%s: 10 bits addr not supported!\n",
				alg_data->adapter.name);
			rc = -EINVAL;
			break;
		}

		alg_data->mif.buf = pmsg->buf;
		alg_data->mif.len = pmsg->len;
		alg_data->mif.order = pmsg->len;
		alg_data->mif.mode = (pmsg->flags & I2C_M_RD) ?
			I2C_SMBUS_READ : I2C_SMBUS_WRITE;
		alg_data->mif.ret = 0;
		alg_data->last = (i == num - 1);

		dev_dbg(&alg_data->adapter.dev, "%s(): mode %d, %d bytes\n",
			__func__, alg_data->mif.mode, alg_data->mif.len);


		/* initialize the completion var */
		init_completion(&alg_data->mif.complete);

		/* Enable master interrupt */
		iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_afie |
				mcntrl_naie | mcntrl_drmie,
			  I2C_REG_CTL(alg_data));

		/* Put start-code and slave-address on the bus. */
		rc = i2c_pnx_start(addr, alg_data);
		if (rc < 0)
			break;

		/* Wait for completion */
		time_left = wait_for_completion_timeout(&alg_data->mif.complete,
							alg_data->timeout);
		if (time_left == 0)
			i2c_pnx_timeout(alg_data);

		if (!(rc = alg_data->mif.ret))
			completed++;
		dev_dbg(&alg_data->adapter.dev,
			"%s(): Complete, return code = %d.\n",
			__func__, rc);

		/* Clear TDI and AFI bits in case they are set. */
		if ((stat = ioread32(I2C_REG_STS(alg_data))) & mstatus_tdi) {
			dev_dbg(&alg_data->adapter.dev,
				"%s: TDI still set... clearing now.\n",
				alg_data->adapter.name);
			iowrite32(stat, I2C_REG_STS(alg_data));
		}
		if ((stat = ioread32(I2C_REG_STS(alg_data))) & mstatus_afi) {
			dev_dbg(&alg_data->adapter.dev,
				"%s: AFI still set... clearing now.\n",
				alg_data->adapter.name);
			iowrite32(stat, I2C_REG_STS(alg_data));
		}
	}

	bus_reset_if_active(alg_data);

	/* Cleanup to be sure... */
	alg_data->mif.buf = NULL;
	alg_data->mif.len = 0;
	alg_data->mif.order = 0;

	dev_dbg(&alg_data->adapter.dev, "%s(): exiting, stat = %x\n",
		__func__, ioread32(I2C_REG_STS(alg_data)));

	if (completed != num)
		return ((rc < 0) ? rc : -EREMOTEIO);

	return num;
}

static u32 i2c_pnx_func(struct i2c_adapter *adapter)
{
	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}

static const struct i2c_algorithm pnx_algorithm = {
	.master_xfer = i2c_pnx_xfer,
	.functionality = i2c_pnx_func,
};

static int i2c_pnx_controller_suspend(struct device *dev)
{
	struct i2c_pnx_algo_data *alg_data = dev_get_drvdata(dev);

	clk_disable_unprepare(alg_data->clk);

	return 0;
}

static int i2c_pnx_controller_resume(struct device *dev)
{
	struct i2c_pnx_algo_data *alg_data = dev_get_drvdata(dev);

	return clk_prepare_enable(alg_data->clk);
}

static DEFINE_SIMPLE_DEV_PM_OPS(i2c_pnx_pm,
				i2c_pnx_controller_suspend,
				i2c_pnx_controller_resume);

static int i2c_pnx_probe(struct platform_device *pdev)
{
	unsigned long tmp;
	int ret = 0;
	struct i2c_pnx_algo_data *alg_data;
	unsigned long freq;
	struct resource *res;
	u32 speed = I2C_PNX_SPEED_KHZ_DEFAULT * 1000;

	alg_data = devm_kzalloc(&pdev->dev, sizeof(*alg_data), GFP_KERNEL);
	if (!alg_data)
		return -ENOMEM;

	platform_set_drvdata(pdev, alg_data);

	alg_data->adapter.dev.parent = &pdev->dev;
	alg_data->adapter.algo = &pnx_algorithm;
	alg_data->adapter.algo_data = alg_data;
	alg_data->adapter.nr = pdev->id;

	alg_data->timeout = msecs_to_jiffies(I2C_PNX_TIMEOUT_DEFAULT);
	if (alg_data->timeout <= 1)
		alg_data->timeout = 2;

#ifdef CONFIG_OF
	alg_data->adapter.dev.of_node = of_node_get(pdev->dev.of_node);
	if (pdev->dev.of_node) {
		of_property_read_u32(pdev->dev.of_node, "clock-frequency",
				     &speed);
		/*
		 * At this point, it is planned to add an OF timeout property.
		 * As soon as there is a consensus about how to call and handle
		 * this, sth. like the following can be put here:
		 *
		 * of_property_read_u32(pdev->dev.of_node, "timeout",
		 *                      &alg_data->timeout);
		 */
	}
#endif
	alg_data->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(alg_data->clk))
		return PTR_ERR(alg_data->clk);

	snprintf(alg_data->adapter.name, sizeof(alg_data->adapter.name),
		 "%s", pdev->name);

	/* Register I/O resource */
	alg_data->ioaddr = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
	if (IS_ERR(alg_data->ioaddr))
		return PTR_ERR(alg_data->ioaddr);

	ret = clk_prepare_enable(alg_data->clk);
	if (ret)
		return ret;

	freq = clk_get_rate(alg_data->clk);

	/*
	 * Clock Divisor High This value is the number of system clocks
	 * the serial clock (SCL) will be high.
	 * For example, if the system clock period is 50 ns and the maximum
	 * desired serial period is 10000 ns (100 kHz), then CLKHI would be
	 * set to 0.5*(f_sys/f_i2c)-2=0.5*(20e6/100e3)-2=98. The actual value
	 * programmed into CLKHI will vary from this slightly due to
	 * variations in the output pad's rise and fall times as well as
	 * the deglitching filter length.
	 */

	tmp = (freq / speed) / 2 - 2;
	if (tmp > 0x3FF)
		tmp = 0x3FF;
	iowrite32(tmp, I2C_REG_CKH(alg_data));
	iowrite32(tmp, I2C_REG_CKL(alg_data));

	iowrite32(mcntrl_reset, I2C_REG_CTL(alg_data));
	if (wait_reset(alg_data)) {
		ret = -ENODEV;
		goto out_clock;
	}
	init_completion(&alg_data->mif.complete);

	alg_data->irq = platform_get_irq(pdev, 0);
	if (alg_data->irq < 0) {
		ret = alg_data->irq;
		goto out_clock;
	}
	ret = devm_request_irq(&pdev->dev, alg_data->irq, i2c_pnx_interrupt,
			       0, pdev->name, alg_data);
	if (ret)
		goto out_clock;

	/* Register this adapter with the I2C subsystem */
	ret = i2c_add_numbered_adapter(&alg_data->adapter);
	if (ret < 0)
		goto out_clock;

	dev_dbg(&pdev->dev, "%s: Master at %pap, irq %d.\n",
		alg_data->adapter.name, &res->start, alg_data->irq);

	return 0;

out_clock:
	clk_disable_unprepare(alg_data->clk);
	return ret;
}

static void i2c_pnx_remove(struct platform_device *pdev)
{
	struct i2c_pnx_algo_data *alg_data = platform_get_drvdata(pdev);

	i2c_del_adapter(&alg_data->adapter);
	clk_disable_unprepare(alg_data->clk);
}

#ifdef CONFIG_OF
static const struct of_device_id i2c_pnx_of_match[] = {
	{ .compatible = "nxp,pnx-i2c" },
	{ },
};
MODULE_DEVICE_TABLE(of, i2c_pnx_of_match);
#endif

static struct platform_driver i2c_pnx_driver = {
	.driver = {
		.name = "pnx-i2c",
		.of_match_table = of_match_ptr(i2c_pnx_of_match),
		.pm = pm_sleep_ptr(&i2c_pnx_pm),
	},
	.probe = i2c_pnx_probe,
	.remove_new = i2c_pnx_remove,
};

static int __init i2c_adap_pnx_init(void)
{
	return platform_driver_register(&i2c_pnx_driver);
}

static void __exit i2c_adap_pnx_exit(void)
{
	platform_driver_unregister(&i2c_pnx_driver);
}

MODULE_AUTHOR("Vitaly Wool");
MODULE_AUTHOR("Dennis Kovalev <source@mvista.com>");
MODULE_DESCRIPTION("I2C driver for Philips IP3204-based I2C busses");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:pnx-i2c");

/* We need to make sure I2C is initialized before USB */
subsys_initcall(i2c_adap_pnx_init);
module_exit(i2c_adap_pnx_exit);