summaryrefslogtreecommitdiff
path: root/drivers/memstick/host/r592.c
blob: 9718661c1fb600d5433bfe202013dbfaae79a717 (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
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
/*
 * Copyright (C) 2010 - Maxim Levitsky
 * driver for Ricoh memstick readers
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/freezer.h>
#include <linux/jiffies.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/pci_ids.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/kthread.h>
#include <linux/sched.h>
#include <linux/highmem.h>
#include <asm/byteorder.h>
#include <linux/swab.h>
#include "r592.h"

static bool r592_enable_dma = 1;
static int debug;

static const char *tpc_names[] = {
	"MS_TPC_READ_MG_STATUS",
	"MS_TPC_READ_LONG_DATA",
	"MS_TPC_READ_SHORT_DATA",
	"MS_TPC_READ_REG",
	"MS_TPC_READ_QUAD_DATA",
	"INVALID",
	"MS_TPC_GET_INT",
	"MS_TPC_SET_RW_REG_ADRS",
	"MS_TPC_EX_SET_CMD",
	"MS_TPC_WRITE_QUAD_DATA",
	"MS_TPC_WRITE_REG",
	"MS_TPC_WRITE_SHORT_DATA",
	"MS_TPC_WRITE_LONG_DATA",
	"MS_TPC_SET_CMD",
};

/**
 * memstick_debug_get_tpc_name - debug helper that returns string for
 * a TPC number
 */
const char *memstick_debug_get_tpc_name(int tpc)
{
	return tpc_names[tpc-1];
}
EXPORT_SYMBOL(memstick_debug_get_tpc_name);


/* Read a register*/
static inline u32 r592_read_reg(struct r592_device *dev, int address)
{
	u32 value = readl(dev->mmio + address);
	dbg_reg("reg #%02d == 0x%08x", address, value);
	return value;
}

/* Write a register */
static inline void r592_write_reg(struct r592_device *dev,
							int address, u32 value)
{
	dbg_reg("reg #%02d <- 0x%08x", address, value);
	writel(value, dev->mmio + address);
}

/* Reads a big endian DWORD register */
static inline u32 r592_read_reg_raw_be(struct r592_device *dev, int address)
{
	u32 value = __raw_readl(dev->mmio + address);
	dbg_reg("reg #%02d == 0x%08x", address, value);
	return be32_to_cpu(value);
}

/* Writes a big endian DWORD register */
static inline void r592_write_reg_raw_be(struct r592_device *dev,
							int address, u32 value)
{
	dbg_reg("reg #%02d <- 0x%08x", address, value);
	__raw_writel(cpu_to_be32(value), dev->mmio + address);
}

/* Set specific bits in a register (little endian) */
static inline void r592_set_reg_mask(struct r592_device *dev,
							int address, u32 mask)
{
	u32 reg = readl(dev->mmio + address);
	dbg_reg("reg #%02d |= 0x%08x (old =0x%08x)", address, mask, reg);
	writel(reg | mask , dev->mmio + address);
}

/* Clear specific bits in a register (little endian) */
static inline void r592_clear_reg_mask(struct r592_device *dev,
						int address, u32 mask)
{
	u32 reg = readl(dev->mmio + address);
	dbg_reg("reg #%02d &= 0x%08x (old = 0x%08x, mask = 0x%08x)",
						address, ~mask, reg, mask);
	writel(reg & ~mask, dev->mmio + address);
}


/* Wait for status bits while checking for errors */
static int r592_wait_status(struct r592_device *dev, u32 mask, u32 wanted_mask)
{
	unsigned long timeout = jiffies + msecs_to_jiffies(1000);
	u32 reg = r592_read_reg(dev, R592_STATUS);

	if ((reg & mask) == wanted_mask)
		return 0;

	while (time_before(jiffies, timeout)) {

		reg = r592_read_reg(dev, R592_STATUS);

		if ((reg & mask) == wanted_mask)
			return 0;

		if (reg & (R592_STATUS_SEND_ERR | R592_STATUS_RECV_ERR))
			return -EIO;

		cpu_relax();
	}
	return -ETIME;
}


/* Enable/disable device */
static int r592_enable_device(struct r592_device *dev, bool enable)
{
	dbg("%sabling the device", enable ? "en" : "dis");

	if (enable) {

		/* Power up the card */
		r592_write_reg(dev, R592_POWER, R592_POWER_0 | R592_POWER_1);

		/* Perform a reset */
		r592_set_reg_mask(dev, R592_IO, R592_IO_RESET);

		msleep(100);
	} else
		/* Power down the card */
		r592_write_reg(dev, R592_POWER, 0);

	return 0;
}

/* Set serial/parallel mode */
static int r592_set_mode(struct r592_device *dev, bool parallel_mode)
{
	if (!parallel_mode) {
		dbg("switching to serial mode");

		/* Set serial mode */
		r592_write_reg(dev, R592_IO_MODE, R592_IO_MODE_SERIAL);

		r592_clear_reg_mask(dev, R592_POWER, R592_POWER_20);

	} else {
		dbg("switching to parallel mode");

		/* This setting should be set _before_ switch TPC */
		r592_set_reg_mask(dev, R592_POWER, R592_POWER_20);

		r592_clear_reg_mask(dev, R592_IO,
			R592_IO_SERIAL1 | R592_IO_SERIAL2);

		/* Set the parallel mode now */
		r592_write_reg(dev, R592_IO_MODE, R592_IO_MODE_PARALLEL);
	}

	dev->parallel_mode = parallel_mode;
	return 0;
}

/* Perform a controller reset without powering down the card */
static void r592_host_reset(struct r592_device *dev)
{
	r592_set_reg_mask(dev, R592_IO, R592_IO_RESET);
	msleep(100);
	r592_set_mode(dev, dev->parallel_mode);
}

/* Disable all hardware interrupts */
static void r592_clear_interrupts(struct r592_device *dev)
{
	/* Disable & ACK all interrupts */
	r592_clear_reg_mask(dev, R592_REG_MSC, IRQ_ALL_ACK_MASK);
	r592_clear_reg_mask(dev, R592_REG_MSC, IRQ_ALL_EN_MASK);
}

/* Tests if there is an CRC error */
static int r592_test_io_error(struct r592_device *dev)
{
	if (!(r592_read_reg(dev, R592_STATUS) &
		(R592_STATUS_SEND_ERR | R592_STATUS_RECV_ERR)))
		return 0;

	return -EIO;
}

/* Ensure that FIFO is ready for use */
static int r592_test_fifo_empty(struct r592_device *dev)
{
	if (r592_read_reg(dev, R592_REG_MSC) & R592_REG_MSC_FIFO_EMPTY)
		return 0;

	dbg("FIFO not ready, trying to reset the device");
	r592_host_reset(dev);

	if (r592_read_reg(dev, R592_REG_MSC) & R592_REG_MSC_FIFO_EMPTY)
		return 0;

	message("FIFO still not ready, giving up");
	return -EIO;
}

/* Activates the DMA transfer from to FIFO */
static void r592_start_dma(struct r592_device *dev, bool is_write)
{
	unsigned long flags;
	u32 reg;
	spin_lock_irqsave(&dev->irq_lock, flags);

	/* Ack interrupts (just in case) + enable them */
	r592_clear_reg_mask(dev, R592_REG_MSC, DMA_IRQ_ACK_MASK);
	r592_set_reg_mask(dev, R592_REG_MSC, DMA_IRQ_EN_MASK);

	/* Set DMA address */
	r592_write_reg(dev, R592_FIFO_DMA, sg_dma_address(&dev->req->sg));

	/* Enable the DMA */
	reg = r592_read_reg(dev, R592_FIFO_DMA_SETTINGS);
	reg |= R592_FIFO_DMA_SETTINGS_EN;

	if (!is_write)
		reg |= R592_FIFO_DMA_SETTINGS_DIR;
	else
		reg &= ~R592_FIFO_DMA_SETTINGS_DIR;
	r592_write_reg(dev, R592_FIFO_DMA_SETTINGS, reg);

	spin_unlock_irqrestore(&dev->irq_lock, flags);
}

/* Cleanups DMA related settings */
static void r592_stop_dma(struct r592_device *dev, int error)
{
	r592_clear_reg_mask(dev, R592_FIFO_DMA_SETTINGS,
		R592_FIFO_DMA_SETTINGS_EN);

	/* This is only a precation */
	r592_write_reg(dev, R592_FIFO_DMA,
			dev->dummy_dma_page_physical_address);

	r592_clear_reg_mask(dev, R592_REG_MSC, DMA_IRQ_EN_MASK);
	r592_clear_reg_mask(dev, R592_REG_MSC, DMA_IRQ_ACK_MASK);
	dev->dma_error = error;
}

/* Test if hardware supports DMA */
static void r592_check_dma(struct r592_device *dev)
{
	dev->dma_capable = r592_enable_dma &&
		(r592_read_reg(dev, R592_FIFO_DMA_SETTINGS) &
			R592_FIFO_DMA_SETTINGS_CAP);
}

/* Transfers fifo contents in/out using DMA */
static int r592_transfer_fifo_dma(struct r592_device *dev)
{
	int len, sg_count;
	bool is_write;

	if (!dev->dma_capable || !dev->req->long_data)
		return -EINVAL;

	len = dev->req->sg.length;
	is_write = dev->req->data_dir == WRITE;

	if (len != R592_LFIFO_SIZE)
		return -EINVAL;

	dbg_verbose("doing dma transfer");

	dev->dma_error = 0;
	INIT_COMPLETION(dev->dma_done);

	/* TODO: hidden assumption about nenth beeing always 1 */
	sg_count = dma_map_sg(&dev->pci_dev->dev, &dev->req->sg, 1, is_write ?
		PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);

	if (sg_count != 1 ||
			(sg_dma_len(&dev->req->sg) < dev->req->sg.length)) {
		message("problem in dma_map_sg");
		return -EIO;
	}

	r592_start_dma(dev, is_write);

	/* Wait for DMA completion */
	if (!wait_for_completion_timeout(
			&dev->dma_done, msecs_to_jiffies(1000))) {
		message("DMA timeout");
		r592_stop_dma(dev, -ETIMEDOUT);
	}

	dma_unmap_sg(&dev->pci_dev->dev, &dev->req->sg, 1, is_write ?
		PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);


	return dev->dma_error;
}

/*
 * Writes the FIFO in 4 byte chunks.
 * If length isn't 4 byte aligned, rest of the data if put to a fifo
 * to be written later
 * Use r592_flush_fifo_write to flush that fifo when writing for the
 * last time
 */
static void r592_write_fifo_pio(struct r592_device *dev,
					unsigned char *buffer, int len)
{
	/* flush spill from former write */
	if (!kfifo_is_empty(&dev->pio_fifo)) {

		u8 tmp[4] = {0};
		int copy_len = kfifo_in(&dev->pio_fifo, buffer, len);

		if (!kfifo_is_full(&dev->pio_fifo))
			return;
		len -= copy_len;
		buffer += copy_len;

		copy_len = kfifo_out(&dev->pio_fifo, tmp, 4);
		WARN_ON(copy_len != 4);
		r592_write_reg_raw_be(dev, R592_FIFO_PIO, *(u32 *)tmp);
	}

	WARN_ON(!kfifo_is_empty(&dev->pio_fifo));

	/* write full dwords */
	while (len >= 4) {
		r592_write_reg_raw_be(dev, R592_FIFO_PIO, *(u32 *)buffer);
		buffer += 4;
		len -= 4;
	}

	/* put remaining bytes to the spill */
	if (len)
		kfifo_in(&dev->pio_fifo, buffer, len);
}

/* Flushes the temporary FIFO used to make aligned DWORD writes */
static void r592_flush_fifo_write(struct r592_device *dev)
{
	u8 buffer[4] = { 0 };
	int len;

	if (kfifo_is_empty(&dev->pio_fifo))
		return;

	len = kfifo_out(&dev->pio_fifo, buffer, 4);
	r592_write_reg_raw_be(dev, R592_FIFO_PIO, *(u32 *)buffer);
}

/*
 * Read a fifo in 4 bytes chunks.
 * If input doesn't fit the buffer, it places bytes of last dword in spill
 * buffer, so that they don't get lost on last read, just throw these away.
 */
static void r592_read_fifo_pio(struct r592_device *dev,
						unsigned char *buffer, int len)
{
	u8 tmp[4];

	/* Read from last spill */
	if (!kfifo_is_empty(&dev->pio_fifo)) {
		int bytes_copied =
			kfifo_out(&dev->pio_fifo, buffer, min(4, len));
		buffer += bytes_copied;
		len -= bytes_copied;

		if (!kfifo_is_empty(&dev->pio_fifo))
			return;
	}

	/* Reads dwords from FIFO */
	while (len >= 4) {
		*(u32 *)buffer = r592_read_reg_raw_be(dev, R592_FIFO_PIO);
		buffer += 4;
		len -= 4;
	}

	if (len) {
		*(u32 *)tmp = r592_read_reg_raw_be(dev, R592_FIFO_PIO);
		kfifo_in(&dev->pio_fifo, tmp, 4);
		len -= kfifo_out(&dev->pio_fifo, buffer, len);
	}

	WARN_ON(len);
	return;
}

/* Transfers actual data using PIO. */
static int r592_transfer_fifo_pio(struct r592_device *dev)
{
	unsigned long flags;

	bool is_write = dev->req->tpc >= MS_TPC_SET_RW_REG_ADRS;
	struct sg_mapping_iter miter;

	kfifo_reset(&dev->pio_fifo);

	if (!dev->req->long_data) {
		if (is_write) {
			r592_write_fifo_pio(dev, dev->req->data,
							dev->req->data_len);
			r592_flush_fifo_write(dev);
		} else
			r592_read_fifo_pio(dev, dev->req->data,
							dev->req->data_len);
		return 0;
	}

	local_irq_save(flags);
	sg_miter_start(&miter, &dev->req->sg, 1, SG_MITER_ATOMIC |
		(is_write ? SG_MITER_FROM_SG : SG_MITER_TO_SG));

	/* Do the transfer fifo<->memory*/
	while (sg_miter_next(&miter))
		if (is_write)
			r592_write_fifo_pio(dev, miter.addr, miter.length);
		else
			r592_read_fifo_pio(dev, miter.addr, miter.length);


	/* Write last few non aligned bytes*/
	if (is_write)
		r592_flush_fifo_write(dev);

	sg_miter_stop(&miter);
	local_irq_restore(flags);
	return 0;
}

/* Executes one TPC (data is read/written from small or large fifo) */
static void r592_execute_tpc(struct r592_device *dev)
{
	bool is_write;
	int len, error;
	u32 status, reg;

	if (!dev->req) {
		message("BUG: tpc execution without request!");
		return;
	}

	is_write = dev->req->tpc >= MS_TPC_SET_RW_REG_ADRS;
	len = dev->req->long_data ?
		dev->req->sg.length : dev->req->data_len;

	/* Ensure that FIFO can hold the input data */
	if (len > R592_LFIFO_SIZE) {
		message("IO: hardware doesn't support TPCs longer that 512");
		error = -ENOSYS;
		goto out;
	}

	if (!(r592_read_reg(dev, R592_REG_MSC) & R592_REG_MSC_PRSNT)) {
		dbg("IO: refusing to send TPC because card is absent");
		error = -ENODEV;
		goto out;
	}

	dbg("IO: executing %s LEN=%d",
			memstick_debug_get_tpc_name(dev->req->tpc), len);

	/* Set IO direction */
	if (is_write)
		r592_set_reg_mask(dev, R592_IO, R592_IO_DIRECTION);
	else
		r592_clear_reg_mask(dev, R592_IO, R592_IO_DIRECTION);


	error = r592_test_fifo_empty(dev);
	if (error)
		goto out;

	/* Transfer write data */
	if (is_write) {
		error = r592_transfer_fifo_dma(dev);
		if (error == -EINVAL)
			error = r592_transfer_fifo_pio(dev);
	}

	if (error)
		goto out;

	/* Trigger the TPC */
	reg = (len << R592_TPC_EXEC_LEN_SHIFT) |
		(dev->req->tpc << R592_TPC_EXEC_TPC_SHIFT) |
			R592_TPC_EXEC_BIG_FIFO;

	r592_write_reg(dev, R592_TPC_EXEC, reg);

	/* Wait for TPC completion */
	status = R592_STATUS_RDY;
	if (dev->req->need_card_int)
		status |= R592_STATUS_CED;

	error = r592_wait_status(dev, status, status);
	if (error) {
		message("card didn't respond");
		goto out;
	}

	/* Test IO errors */
	error = r592_test_io_error(dev);
	if (error) {
		dbg("IO error");
		goto out;
	}

	/* Read data from FIFO */
	if (!is_write) {
		error = r592_transfer_fifo_dma(dev);
		if (error == -EINVAL)
			error = r592_transfer_fifo_pio(dev);
	}

	/* read INT reg. This can be shortened with shifts, but that way
		its more readable */
	if (dev->parallel_mode && dev->req->need_card_int) {

		dev->req->int_reg = 0;
		status = r592_read_reg(dev, R592_STATUS);

		if (status & R592_STATUS_P_CMDNACK)
			dev->req->int_reg |= MEMSTICK_INT_CMDNAK;
		if (status & R592_STATUS_P_BREQ)
			dev->req->int_reg |= MEMSTICK_INT_BREQ;
		if (status & R592_STATUS_P_INTERR)
			dev->req->int_reg |= MEMSTICK_INT_ERR;
		if (status & R592_STATUS_P_CED)
			dev->req->int_reg |= MEMSTICK_INT_CED;
	}

	if (error)
		dbg("FIFO read error");
out:
	dev->req->error = error;
	r592_clear_reg_mask(dev, R592_REG_MSC, R592_REG_MSC_LED);
	return;
}

/* Main request processing thread */
static int r592_process_thread(void *data)
{
	int error;
	struct r592_device *dev = (struct r592_device *)data;
	unsigned long flags;

	while (!kthread_should_stop()) {
		spin_lock_irqsave(&dev->io_thread_lock, flags);
		set_current_state(TASK_INTERRUPTIBLE);
		error = memstick_next_req(dev->host, &dev->req);
		spin_unlock_irqrestore(&dev->io_thread_lock, flags);

		if (error) {
			if (error == -ENXIO || error == -EAGAIN) {
				dbg_verbose("IO: done IO, sleeping");
			} else {
				dbg("IO: unknown error from "
					"memstick_next_req %d", error);
			}

			if (kthread_should_stop())
				set_current_state(TASK_RUNNING);

			schedule();
		} else {
			set_current_state(TASK_RUNNING);
			r592_execute_tpc(dev);
		}
	}
	return 0;
}

/* Reprogram chip to detect change in card state */
/* eg, if card is detected, arm it to detect removal, and vice versa */
static void r592_update_card_detect(struct r592_device *dev)
{
	u32 reg = r592_read_reg(dev, R592_REG_MSC);
	bool card_detected = reg & R592_REG_MSC_PRSNT;

	dbg("update card detect. card state: %s", card_detected ?
		"present" : "absent");

	reg &= ~((R592_REG_MSC_IRQ_REMOVE | R592_REG_MSC_IRQ_INSERT) << 16);

	if (card_detected)
		reg |= (R592_REG_MSC_IRQ_REMOVE << 16);
	else
		reg |= (R592_REG_MSC_IRQ_INSERT << 16);

	r592_write_reg(dev, R592_REG_MSC, reg);
}

/* Timer routine that fires 1 second after last card detection event, */
static void r592_detect_timer(long unsigned int data)
{
	struct r592_device *dev = (struct r592_device *)data;
	r592_update_card_detect(dev);
	memstick_detect_change(dev->host);
}

/* Interrupt handler */
static irqreturn_t r592_irq(int irq, void *data)
{
	struct r592_device *dev = (struct r592_device *)data;
	irqreturn_t ret = IRQ_NONE;
	u32 reg;
	u16 irq_enable, irq_status;
	unsigned long flags;
	int error;

	spin_lock_irqsave(&dev->irq_lock, flags);

	reg = r592_read_reg(dev, R592_REG_MSC);
	irq_enable = reg >> 16;
	irq_status = reg & 0xFFFF;

	/* Ack the interrupts */
	reg &= ~irq_status;
	r592_write_reg(dev, R592_REG_MSC, reg);

	/* Get the IRQ status minus bits that aren't enabled */
	irq_status &= (irq_enable);

	/* Due to limitation of memstick core, we don't look at bits that
		indicate that card was removed/inserted and/or present */
	if (irq_status & (R592_REG_MSC_IRQ_INSERT | R592_REG_MSC_IRQ_REMOVE)) {

		bool card_was_added = irq_status & R592_REG_MSC_IRQ_INSERT;
		ret = IRQ_HANDLED;

		message("IRQ: card %s", card_was_added ? "added" : "removed");

		mod_timer(&dev->detect_timer,
			jiffies + msecs_to_jiffies(card_was_added ? 500 : 50));
	}

	if (irq_status &
		(R592_REG_MSC_FIFO_DMA_DONE | R592_REG_MSC_FIFO_DMA_ERR)) {
		ret = IRQ_HANDLED;

		if (irq_status & R592_REG_MSC_FIFO_DMA_ERR) {
			message("IRQ: DMA error");
			error = -EIO;
		} else {
			dbg_verbose("IRQ: dma done");
			error = 0;
		}

		r592_stop_dma(dev, error);
		complete(&dev->dma_done);
	}

	spin_unlock_irqrestore(&dev->irq_lock, flags);
	return ret;
}

/* External inteface: set settings */
static int r592_set_param(struct memstick_host *host,
			enum memstick_param param, int value)
{
	struct r592_device *dev = memstick_priv(host);

	switch (param) {
	case MEMSTICK_POWER:
		switch (value) {
		case MEMSTICK_POWER_ON:
			return r592_enable_device(dev, true);
		case MEMSTICK_POWER_OFF:
			return r592_enable_device(dev, false);
		default:
			return -EINVAL;
		}
	case MEMSTICK_INTERFACE:
		switch (value) {
		case MEMSTICK_SERIAL:
			return r592_set_mode(dev, 0);
		case MEMSTICK_PAR4:
			return r592_set_mode(dev, 1);
		default:
			return -EINVAL;
		}
	default:
		return -EINVAL;
	}
}

/* External interface: submit requests */
static void r592_submit_req(struct memstick_host *host)
{
	struct r592_device *dev = memstick_priv(host);
	unsigned long flags;

	if (dev->req)
		return;

	spin_lock_irqsave(&dev->io_thread_lock, flags);
	if (wake_up_process(dev->io_thread))
		dbg_verbose("IO thread woken to process requests");
	spin_unlock_irqrestore(&dev->io_thread_lock, flags);
}

static const struct pci_device_id r592_pci_id_tbl[] = {

	{ PCI_VDEVICE(RICOH, 0x0592), },
	{ },
};

/* Main entry */
static int r592_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
	int error = -ENOMEM;
	struct memstick_host *host;
	struct r592_device *dev;

	/* Allocate memory */
	host = memstick_alloc_host(sizeof(struct r592_device), &pdev->dev);
	if (!host)
		goto error1;

	dev = memstick_priv(host);
	dev->host = host;
	dev->pci_dev = pdev;
	pci_set_drvdata(pdev, dev);

	/* pci initialization */
	error = pci_enable_device(pdev);
	if (error)
		goto error2;

	pci_set_master(pdev);
	error = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
	if (error)
		goto error3;

	error = pci_request_regions(pdev, DRV_NAME);
	if (error)
		goto error3;

	dev->mmio = pci_ioremap_bar(pdev, 0);
	if (!dev->mmio)
		goto error4;

	dev->irq = pdev->irq;
	spin_lock_init(&dev->irq_lock);
	spin_lock_init(&dev->io_thread_lock);
	init_completion(&dev->dma_done);
	INIT_KFIFO(dev->pio_fifo);
	setup_timer(&dev->detect_timer,
		r592_detect_timer, (long unsigned int)dev);

	/* Host initialization */
	host->caps = MEMSTICK_CAP_PAR4;
	host->request = r592_submit_req;
	host->set_param = r592_set_param;
	r592_check_dma(dev);

	dev->io_thread = kthread_run(r592_process_thread, dev, "r592_io");
	if (IS_ERR(dev->io_thread)) {
		error = PTR_ERR(dev->io_thread);
		goto error5;
	}

	/* This is just a precation, so don't fail */
	dev->dummy_dma_page = pci_alloc_consistent(pdev, PAGE_SIZE,
		&dev->dummy_dma_page_physical_address);
	r592_stop_dma(dev , 0);

	if (request_irq(dev->irq, &r592_irq, IRQF_SHARED,
			  DRV_NAME, dev))
		goto error6;

	r592_update_card_detect(dev);
	if (memstick_add_host(host))
		goto error7;

	message("driver successfully loaded");
	return 0;
error7:
	free_irq(dev->irq, dev);
error6:
	if (dev->dummy_dma_page)
		pci_free_consistent(pdev, PAGE_SIZE, dev->dummy_dma_page,
			dev->dummy_dma_page_physical_address);

	kthread_stop(dev->io_thread);
error5:
	iounmap(dev->mmio);
error4:
	pci_release_regions(pdev);
error3:
	pci_disable_device(pdev);
error2:
	memstick_free_host(host);
error1:
	return error;
}

static void r592_remove(struct pci_dev *pdev)
{
	int error = 0;
	struct r592_device *dev = pci_get_drvdata(pdev);

	/* Stop the processing thread.
	That ensures that we won't take any more requests */
	kthread_stop(dev->io_thread);

	r592_enable_device(dev, false);

	while (!error && dev->req) {
		dev->req->error = -ETIME;
		error = memstick_next_req(dev->host, &dev->req);
	}
	memstick_remove_host(dev->host);

	free_irq(dev->irq, dev);
	iounmap(dev->mmio);
	pci_release_regions(pdev);
	pci_disable_device(pdev);
	memstick_free_host(dev->host);

	if (dev->dummy_dma_page)
		pci_free_consistent(pdev, PAGE_SIZE, dev->dummy_dma_page,
			dev->dummy_dma_page_physical_address);
}

#ifdef CONFIG_PM_SLEEP
static int r592_suspend(struct device *core_dev)
{
	struct pci_dev *pdev = to_pci_dev(core_dev);
	struct r592_device *dev = pci_get_drvdata(pdev);

	r592_clear_interrupts(dev);
	memstick_suspend_host(dev->host);
	del_timer_sync(&dev->detect_timer);
	return 0;
}

static int r592_resume(struct device *core_dev)
{
	struct pci_dev *pdev = to_pci_dev(core_dev);
	struct r592_device *dev = pci_get_drvdata(pdev);

	r592_clear_interrupts(dev);
	r592_enable_device(dev, false);
	memstick_resume_host(dev->host);
	r592_update_card_detect(dev);
	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(r592_pm_ops, r592_suspend, r592_resume);

MODULE_DEVICE_TABLE(pci, r592_pci_id_tbl);

static struct pci_driver r852_pci_driver = {
	.name		= DRV_NAME,
	.id_table	= r592_pci_id_tbl,
	.probe		= r592_probe,
	.remove		= r592_remove,
	.driver.pm	= &r592_pm_ops,
};

static __init int r592_module_init(void)
{
	return pci_register_driver(&r852_pci_driver);
}

static void __exit r592_module_exit(void)
{
	pci_unregister_driver(&r852_pci_driver);
}

module_init(r592_module_init);
module_exit(r592_module_exit);

module_param_named(enable_dma, r592_enable_dma, bool, S_IRUGO);
MODULE_PARM_DESC(enable_dma, "Enable usage of the DMA (default)");
module_param(debug, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug level (0-3)");

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Maxim Levitsky <maximlevitsky@gmail.com>");
MODULE_DESCRIPTION("Ricoh R5C592 Memstick/Memstick PRO card reader driver");