aboutsummaryrefslogblamecommitdiffstats
path: root/drivers/edac/ppc4xx_edac.c
blob: 0de7d8770891e5421a52f7a8732b66e09dd13423 (plain) (tree)
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


















































































































                                                                       
                                                





































































                                                                               
                                                            
                                                              













                                                                    
                                                    

                                                     




                                                    























































































































































































































































































































































































































































































































































































































































































                                                                                 
                                                            






                                                                    
                                                                     













































































































                                                                               
                                                   



                                                                 













                                                                         
                                               





                                                               
                                                       
 
                                                                 


















































































                                                                        
                                                                              



                                                        
                                                 
















































































































                                                                              






                                                                     
                                                                  



                             
                                                       



























































                                                                              
                                                                 





















































                                                                          
                                              




























































                                                                        
                                                             











                                                                 
                                                        










                                                                               
/*
 * Copyright (c) 2008 Nuovation System Designs, LLC
 *   Grant Erickson <gerickson@nuovations.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; version 2 of the
 * License.
 *
 */

#include <linux/edac.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/types.h>

#include <asm/dcr.h>

#include "edac_core.h"
#include "ppc4xx_edac.h"

/*
 * This file implements a driver for monitoring and handling events
 * associated with the IMB DDR2 ECC controller found in the AMCC/IBM
 * 405EX[r], 440SP, 440SPe, 460EX, 460GT and 460SX.
 *
 * As realized in the 405EX[r], this controller features:
 *
 *   - Support for registered- and non-registered DDR1 and DDR2 memory.
 *   - 32-bit or 16-bit memory interface with optional ECC.
 *
 *     o ECC support includes:
 *
 *       - 4-bit SEC/DED
 *       - Aligned-nibble error detect
 *       - Bypass mode
 *
 *   - Two (2) memory banks/ranks.
 *   - Up to 1 GiB per bank/rank in 32-bit mode and up to 512 MiB per
 *     bank/rank in 16-bit mode.
 *
 * As realized in the 440SP and 440SPe, this controller changes/adds:
 *
 *   - 64-bit or 32-bit memory interface with optional ECC.
 *
 *     o ECC support includes:
 *
 *       - 8-bit SEC/DED
 *       - Aligned-nibble error detect
 *       - Bypass mode
 *
 *   - Up to 4 GiB per bank/rank in 64-bit mode and up to 2 GiB
 *     per bank/rank in 32-bit mode.
 *
 * As realized in the 460EX and 460GT, this controller changes/adds:
 *
 *   - 64-bit or 32-bit memory interface with optional ECC.
 *
 *     o ECC support includes:
 *
 *       - 8-bit SEC/DED
 *       - Aligned-nibble error detect
 *       - Bypass mode
 *
 *   - Four (4) memory banks/ranks.
 *   - Up to 16 GiB per bank/rank in 64-bit mode and up to 8 GiB
 *     per bank/rank in 32-bit mode.
 *
 * At present, this driver has ONLY been tested against the controller
 * realization in the 405EX[r] on the AMCC Kilauea and Haleakala
 * boards (256 MiB w/o ECC memory soldered onto the board) and a
 * proprietary board based on those designs (128 MiB ECC memory, also
 * soldered onto the board).
 *
 * Dynamic feature detection and handling needs to be added for the
 * other realizations of this controller listed above.
 *
 * Eventually, this driver will likely be adapted to the above variant
 * realizations of this controller as well as broken apart to handle
 * the other known ECC-capable controllers prevalent in other 4xx
 * processors:
 *
 *   - IBM SDRAM (405GP, 405CR and 405EP) "ibm,sdram-4xx"
 *   - IBM DDR1 (440GP, 440GX, 440EP and 440GR) "ibm,sdram-4xx-ddr"
 *   - Denali DDR1/DDR2 (440EPX and 440GRX) "denali,sdram-4xx-ddr2"
 *
 * For this controller, unfortunately, correctable errors report
 * nothing more than the beat/cycle and byte/lane the correction
 * occurred on and the check bit group that covered the error.
 *
 * In contrast, uncorrectable errors also report the failing address,
 * the bus master and the transaction direction (i.e. read or write)
 *
 * Regardless of whether the error is a CE or a UE, we report the
 * following pieces of information in the driver-unique message to the
 * EDAC subsystem:
 *
 *   - Device tree path
 *   - Bank(s)
 *   - Check bit error group
 *   - Beat(s)/lane(s)
 */

/* Preprocessor Definitions */

#define EDAC_OPSTATE_INT_STR		"interrupt"
#define EDAC_OPSTATE_POLL_STR		"polled"
#define EDAC_OPSTATE_UNKNOWN_STR	"unknown"

#define PPC4XX_EDAC_MODULE_NAME		"ppc4xx_edac"
#define PPC4XX_EDAC_MODULE_REVISION	"v1.0.0"

#define PPC4XX_EDAC_MESSAGE_SIZE	256

/*
 * Kernel logging without an EDAC instance
 */
#define ppc4xx_edac_printk(level, fmt, arg...) \
	edac_printk(level, "PPC4xx MC", fmt, ##arg)

/*
 * Kernel logging with an EDAC instance
 */
#define ppc4xx_edac_mc_printk(level, mci, fmt, arg...) \
	edac_mc_chipset_printk(mci, level, "PPC4xx", fmt, ##arg)

/*
 * Macros to convert bank configuration size enumerations into MiB and
 * page values.
 */
#define SDRAM_MBCF_SZ_MiB_MIN		4
#define SDRAM_MBCF_SZ_TO_MiB(n)		(SDRAM_MBCF_SZ_MiB_MIN \
					 << (SDRAM_MBCF_SZ_DECODE(n)))
#define SDRAM_MBCF_SZ_TO_PAGES(n)	(SDRAM_MBCF_SZ_MiB_MIN \
					 << (20 - PAGE_SHIFT + \
					     SDRAM_MBCF_SZ_DECODE(n)))

/*
 * The ibm,sdram-4xx-ddr2 Device Control Registers (DCRs) are
 * indirectly acccessed and have a base and length defined by the
 * device tree. The base can be anything; however, we expect the
 * length to be precisely two registers, the first for the address
 * window and the second for the data window.
 */
#define SDRAM_DCR_RESOURCE_LEN		2
#define SDRAM_DCR_ADDR_OFFSET		0
#define SDRAM_DCR_DATA_OFFSET		1

/*
 * Device tree interrupt indices
 */
#define INTMAP_ECCDED_INDEX		0	/* Double-bit Error Detect */
#define INTMAP_ECCSEC_INDEX		1	/* Single-bit Error Correct */

/* Type Definitions */

/*
 * PPC4xx SDRAM memory controller private instance data
 */
struct ppc4xx_edac_pdata {
	dcr_host_t dcr_host;	/* Indirect DCR address/data window mapping */
	struct {
		int sec;	/* Single-bit correctable error IRQ assigned */
		int ded;	/* Double-bit detectable error IRQ assigned */
	} irqs;
};

/*
 * Various status data gathered and manipulated when checking and
 * reporting ECC status.
 */
struct ppc4xx_ecc_status {
	u32 ecces;
	u32 besr;
	u32 bearh;
	u32 bearl;
	u32 wmirq;
};

/* Function Prototypes */

static int ppc4xx_edac_probe(struct platform_device *device)
static int ppc4xx_edac_remove(struct platform_device *device);

/* Global Variables */

/*
 * Device tree node type and compatible tuples this driver can match
 * on.
 */
static struct of_device_id ppc4xx_edac_match[] = {
	{
		.compatible	= "ibm,sdram-4xx-ddr2"
	},
	{ }
};

static struct platform_driver ppc4xx_edac_driver = {
	.probe			= ppc4xx_edac_probe,
	.remove			= ppc4xx_edac_remove,
	.driver = {
		.owner = THIS_MODULE,
		.name = PPC4XX_EDAC_MODULE_NAME
		.of_match_table = ppc4xx_edac_match,
	},
};

/*
 * TODO: The row and channel parameters likely need to be dynamically
 * set based on the aforementioned variant controller realizations.
 */
static const unsigned ppc4xx_edac_nr_csrows = 2;
static const unsigned ppc4xx_edac_nr_chans = 1;

/*
 * Strings associated with PLB master IDs capable of being posted in
 * SDRAM_BESR or SDRAM_WMIRQ on uncorrectable ECC errors.
 */
static const char * const ppc4xx_plb_masters[9] = {
	[SDRAM_PLB_M0ID_ICU]	= "ICU",
	[SDRAM_PLB_M0ID_PCIE0]	= "PCI-E 0",
	[SDRAM_PLB_M0ID_PCIE1]	= "PCI-E 1",
	[SDRAM_PLB_M0ID_DMA]	= "DMA",
	[SDRAM_PLB_M0ID_DCU]	= "DCU",
	[SDRAM_PLB_M0ID_OPB]	= "OPB",
	[SDRAM_PLB_M0ID_MAL]	= "MAL",
	[SDRAM_PLB_M0ID_SEC]	= "SEC",
	[SDRAM_PLB_M0ID_AHB]	= "AHB"
};

/**
 * mfsdram - read and return controller register data
 * @dcr_host: A pointer to the DCR mapping.
 * @idcr_n: The indirect DCR register to read.
 *
 * This routine reads and returns the data associated with the
 * controller's specified indirect DCR register.
 *
 * Returns the read data.
 */
static inline u32
mfsdram(const dcr_host_t *dcr_host, unsigned int idcr_n)
{
	return __mfdcri(dcr_host->base + SDRAM_DCR_ADDR_OFFSET,
			dcr_host->base + SDRAM_DCR_DATA_OFFSET,
			idcr_n);
}

/**
 * mtsdram - write controller register data
 * @dcr_host: A pointer to the DCR mapping.
 * @idcr_n: The indirect DCR register to write.
 * @value: The data to write.
 *
 * This routine writes the provided data to the controller's specified
 * indirect DCR register.
 */
static inline void
mtsdram(const dcr_host_t *dcr_host, unsigned int idcr_n, u32 value)
{
	return __mtdcri(dcr_host->base + SDRAM_DCR_ADDR_OFFSET,
			dcr_host->base + SDRAM_DCR_DATA_OFFSET,
			idcr_n,
			value);
}

/**
 * ppc4xx_edac_check_bank_error - check a bank for an ECC bank error
 * @status: A pointer to the ECC status structure to check for an
 *          ECC bank error.
 * @bank: The bank to check for an ECC error.
 *
 * This routine determines whether the specified bank has an ECC
 * error.
 *
 * Returns true if the specified bank has an ECC error; otherwise,
 * false.
 */
static bool
ppc4xx_edac_check_bank_error(const struct ppc4xx_ecc_status *status,
			     unsigned int bank)
{
	switch (bank) {
	case 0:
		return status->ecces & SDRAM_ECCES_BK0ER;
	case 1:
		return status->ecces & SDRAM_ECCES_BK1ER;
	default:
		return false;
	}
}

/**
 * ppc4xx_edac_generate_bank_message - generate interpretted bank status message
 * @mci: A pointer to the EDAC memory controller instance associated
 *       with the bank message being generated.
 * @status: A pointer to the ECC status structure to generate the
 *          message from.
 * @buffer: A pointer to the buffer in which to generate the
 *          message.
 * @size: The size, in bytes, of space available in buffer.
 *
 * This routine generates to the provided buffer the portion of the
 * driver-unique report message associated with the ECCESS[BKNER]
 * field of the specified ECC status.
 *
 * Returns the number of characters generated on success; otherwise, <
 * 0 on error.
 */
static int
ppc4xx_edac_generate_bank_message(const struct mem_ctl_info *mci,
				  const struct ppc4xx_ecc_status *status,
				  char *buffer,
				  size_t size)
{
	int n, total = 0;
	unsigned int row, rows;

	n = snprintf(buffer, size, "%s: Banks: ", mci->dev_name);

	if (n < 0 || n >= size)
		goto fail;

	buffer += n;
	size -= n;
	total += n;

	for (rows = 0, row = 0; row < mci->nr_csrows; row++) {
		if (ppc4xx_edac_check_bank_error(status, row)) {
			n = snprintf(buffer, size, "%s%u",
					(rows++ ? ", " : ""), row);

			if (n < 0 || n >= size)
				goto fail;

			buffer += n;
			size -= n;
			total += n;
		}
	}

	n = snprintf(buffer, size, "%s; ", rows ? "" : "None");

	if (n < 0 || n >= size)
		goto fail;

	buffer += n;
	size -= n;
	total += n;

 fail:
	return total;
}

/**
 * ppc4xx_edac_generate_checkbit_message - generate interpretted checkbit message
 * @mci: A pointer to the EDAC memory controller instance associated
 *       with the checkbit message being generated.
 * @status: A pointer to the ECC status structure to generate the
 *          message from.
 * @buffer: A pointer to the buffer in which to generate the
 *          message.
 * @size: The size, in bytes, of space available in buffer.
 *
 * This routine generates to the provided buffer the portion of the
 * driver-unique report message associated with the ECCESS[CKBER]
 * field of the specified ECC status.
 *
 * Returns the number of characters generated on success; otherwise, <
 * 0 on error.
 */
static int
ppc4xx_edac_generate_checkbit_message(const struct mem_ctl_info *mci,
				      const struct ppc4xx_ecc_status *status,
				      char *buffer,
				      size_t size)
{
	const struct ppc4xx_edac_pdata *pdata = mci->pvt_info;
	const char *ckber = NULL;

	switch (status->ecces & SDRAM_ECCES_CKBER_MASK) {
	case SDRAM_ECCES_CKBER_NONE:
		ckber = "None";
		break;
	case SDRAM_ECCES_CKBER_32_ECC_0_3:
		ckber = "ECC0:3";
		break;
	case SDRAM_ECCES_CKBER_32_ECC_4_8:
		switch (mfsdram(&pdata->dcr_host, SDRAM_MCOPT1) &
			SDRAM_MCOPT1_WDTH_MASK) {
		case SDRAM_MCOPT1_WDTH_16:
			ckber = "ECC0:3";
			break;
		case SDRAM_MCOPT1_WDTH_32:
			ckber = "ECC4:8";
			break;
		default:
			ckber = "Unknown";
			break;
		}
		break;
	case SDRAM_ECCES_CKBER_32_ECC_0_8:
		ckber = "ECC0:8";
		break;
	default:
		ckber = "Unknown";
		break;
	}

	return snprintf(buffer, size, "Checkbit Error: %s", ckber);
}

/**
 * ppc4xx_edac_generate_lane_message - generate interpretted byte lane message
 * @mci: A pointer to the EDAC memory controller instance associated
 *       with the byte lane message being generated.
 * @status: A pointer to the ECC status structure to generate the
 *          message from.
 * @buffer: A pointer to the buffer in which to generate the
 *          message.
 * @size: The size, in bytes, of space available in buffer.
 *
 * This routine generates to the provided buffer the portion of the
 * driver-unique report message associated with the ECCESS[BNCE]
 * field of the specified ECC status.
 *
 * Returns the number of characters generated on success; otherwise, <
 * 0 on error.
 */
static int
ppc4xx_edac_generate_lane_message(const struct mem_ctl_info *mci,
				  const struct ppc4xx_ecc_status *status,
				  char *buffer,
				  size_t size)
{
	int n, total = 0;
	unsigned int lane, lanes;
	const unsigned int first_lane = 0;
	const unsigned int lane_count = 16;

	n = snprintf(buffer, size, "; Byte Lane Errors: ");

	if (n < 0 || n >= size)
		goto fail;

	buffer += n;
	size -= n;
	total += n;

	for (lanes = 0, lane = first_lane; lane < lane_count; lane++) {
		if ((status->ecces & SDRAM_ECCES_BNCE_ENCODE(lane)) != 0) {
			n = snprintf(buffer, size,
				     "%s%u",
				     (lanes++ ? ", " : ""), lane);

			if (n < 0 || n >= size)
				goto fail;

			buffer += n;
			size -= n;
			total += n;
		}
	}

	n = snprintf(buffer, size, "%s; ", lanes ? "" : "None");

	if (n < 0 || n >= size)
		goto fail;

	buffer += n;
	size -= n;
	total += n;

 fail:
	return total;
}

/**
 * ppc4xx_edac_generate_ecc_message - generate interpretted ECC status message
 * @mci: A pointer to the EDAC memory controller instance associated
 *       with the ECCES message being generated.
 * @status: A pointer to the ECC status structure to generate the
 *          message from.
 * @buffer: A pointer to the buffer in which to generate the
 *          message.
 * @size: The size, in bytes, of space available in buffer.
 *
 * This routine generates to the provided buffer the portion of the
 * driver-unique report message associated with the ECCESS register of
 * the specified ECC status.
 *
 * Returns the number of characters generated on success; otherwise, <
 * 0 on error.
 */
static int
ppc4xx_edac_generate_ecc_message(const struct mem_ctl_info *mci,
				 const struct ppc4xx_ecc_status *status,
				 char *buffer,
				 size_t size)
{
	int n, total = 0;

	n = ppc4xx_edac_generate_bank_message(mci, status, buffer, size);

	if (n < 0 || n >= size)
		goto fail;

	buffer += n;
	size -= n;
	total += n;

	n = ppc4xx_edac_generate_checkbit_message(mci, status, buffer, size);

	if (n < 0 || n >= size)
		goto fail;

	buffer += n;
	size -= n;
	total += n;

	n = ppc4xx_edac_generate_lane_message(mci, status, buffer, size);

	if (n < 0 || n >= size)
		goto fail;

	buffer += n;
	size -= n;
	total += n;

 fail:
	return total;
}

/**
 * ppc4xx_edac_generate_plb_message - generate interpretted PLB status message
 * @mci: A pointer to the EDAC memory controller instance associated
 *       with the PLB message being generated.
 * @status: A pointer to the ECC status structure to generate the
 *          message from.
 * @buffer: A pointer to the buffer in which to generate the
 *          message.
 * @size: The size, in bytes, of space available in buffer.
 *
 * This routine generates to the provided buffer the portion of the
 * driver-unique report message associated with the PLB-related BESR
 * and/or WMIRQ registers of the specified ECC status.
 *
 * Returns the number of characters generated on success; otherwise, <
 * 0 on error.
 */
static int
ppc4xx_edac_generate_plb_message(const struct mem_ctl_info *mci,
				 const struct ppc4xx_ecc_status *status,
				 char *buffer,
				 size_t size)
{
	unsigned int master;
	bool read;

	if ((status->besr & SDRAM_BESR_MASK) == 0)
		return 0;

	if ((status->besr & SDRAM_BESR_M0ET_MASK) == SDRAM_BESR_M0ET_NONE)
		return 0;

	read = ((status->besr & SDRAM_BESR_M0RW_MASK) == SDRAM_BESR_M0RW_READ);

	master = SDRAM_BESR_M0ID_DECODE(status->besr);

	return snprintf(buffer, size,
			"%s error w/ PLB master %u \"%s\"; ",
			(read ? "Read" : "Write"),
			master,
			(((master >= SDRAM_PLB_M0ID_FIRST) &&
			  (master <= SDRAM_PLB_M0ID_LAST)) ?
			 ppc4xx_plb_masters[master] : "UNKNOWN"));
}

/**
 * ppc4xx_edac_generate_message - generate interpretted status message
 * @mci: A pointer to the EDAC memory controller instance associated
 *       with the driver-unique message being generated.
 * @status: A pointer to the ECC status structure to generate the
 *          message from.
 * @buffer: A pointer to the buffer in which to generate the
 *          message.
 * @size: The size, in bytes, of space available in buffer.
 *
 * This routine generates to the provided buffer the driver-unique
 * EDAC report message from the specified ECC status.
 */
static void
ppc4xx_edac_generate_message(const struct mem_ctl_info *mci,
			     const struct ppc4xx_ecc_status *status,
			     char *buffer,
			     size_t size)
{
	int n;

	if (buffer == NULL || size == 0)
		return;

	n = ppc4xx_edac_generate_ecc_message(mci, status, buffer, size);

	if (n < 0 || n >= size)
		return;

	buffer += n;
	size -= n;

	ppc4xx_edac_generate_plb_message(mci, status, buffer, size);
}

#ifdef DEBUG
/**
 * ppc4xx_ecc_dump_status - dump controller ECC status registers
 * @mci: A pointer to the EDAC memory controller instance
 *       associated with the status being dumped.
 * @status: A pointer to the ECC status structure to generate the
 *          dump from.
 *
 * This routine dumps to the kernel log buffer the raw and
 * interpretted specified ECC status.
 */
static void
ppc4xx_ecc_dump_status(const struct mem_ctl_info *mci,
		       const struct ppc4xx_ecc_status *status)
{
	char message[PPC4XX_EDAC_MESSAGE_SIZE];

	ppc4xx_edac_generate_message(mci, status, message, sizeof(message));

	ppc4xx_edac_mc_printk(KERN_INFO, mci,
			      "\n"
			      "\tECCES: 0x%08x\n"
			      "\tWMIRQ: 0x%08x\n"
			      "\tBESR:  0x%08x\n"
			      "\tBEAR:  0x%08x%08x\n"
			      "\t%s\n",
			      status->ecces,
			      status->wmirq,
			      status->besr,
			      status->bearh,
			      status->bearl,
			      message);
}
#endif /* DEBUG */

/**
 * ppc4xx_ecc_get_status - get controller ECC status
 * @mci: A pointer to the EDAC memory controller instance
 *       associated with the status being retrieved.
 * @status: A pointer to the ECC status structure to populate the
 *          ECC status with.
 *
 * This routine reads and masks, as appropriate, all the relevant
 * status registers that deal with ibm,sdram-4xx-ddr2 ECC errors.
 * While we read all of them, for correctable errors, we only expect
 * to deal with ECCES. For uncorrectable errors, we expect to deal
 * with all of them.
 */
static void
ppc4xx_ecc_get_status(const struct mem_ctl_info *mci,
		      struct ppc4xx_ecc_status *status)
{
	const struct ppc4xx_edac_pdata *pdata = mci->pvt_info;
	const dcr_host_t *dcr_host = &pdata->dcr_host;

	status->ecces = mfsdram(dcr_host, SDRAM_ECCES) & SDRAM_ECCES_MASK;
	status->wmirq = mfsdram(dcr_host, SDRAM_WMIRQ) & SDRAM_WMIRQ_MASK;
	status->besr  = mfsdram(dcr_host, SDRAM_BESR)  & SDRAM_BESR_MASK;
	status->bearl = mfsdram(dcr_host, SDRAM_BEARL);
	status->bearh = mfsdram(dcr_host, SDRAM_BEARH);
}

/**
 * ppc4xx_ecc_clear_status - clear controller ECC status
 * @mci: A pointer to the EDAC memory controller instance
 *       associated with the status being cleared.
 * @status: A pointer to the ECC status structure containing the
 *          values to write to clear the ECC status.
 *
 * This routine clears--by writing the masked (as appropriate) status
 * values back to--the status registers that deal with
 * ibm,sdram-4xx-ddr2 ECC errors.
 */
static void
ppc4xx_ecc_clear_status(const struct mem_ctl_info *mci,
			const struct ppc4xx_ecc_status *status)
{
	const struct ppc4xx_edac_pdata *pdata = mci->pvt_info;
	const dcr_host_t *dcr_host = &pdata->dcr_host;

	mtsdram(dcr_host, SDRAM_ECCES,	status->ecces & SDRAM_ECCES_MASK);
	mtsdram(dcr_host, SDRAM_WMIRQ,	status->wmirq & SDRAM_WMIRQ_MASK);
	mtsdram(dcr_host, SDRAM_BESR,	status->besr & SDRAM_BESR_MASK);
	mtsdram(dcr_host, SDRAM_BEARL,	0);
	mtsdram(dcr_host, SDRAM_BEARH,	0);
}

/**
 * ppc4xx_edac_handle_ce - handle controller correctable ECC error (CE)
 * @mci: A pointer to the EDAC memory controller instance
 *       associated with the correctable error being handled and reported.
 * @status: A pointer to the ECC status structure associated with
 *          the correctable error being handled and reported.
 *
 * This routine handles an ibm,sdram-4xx-ddr2 controller ECC
 * correctable error. Per the aforementioned discussion, there's not
 * enough status available to use the full EDAC correctable error
 * interface, so we just pass driver-unique message to the "no info"
 * interface.
 */
static void
ppc4xx_edac_handle_ce(struct mem_ctl_info *mci,
		      const struct ppc4xx_ecc_status *status)
{
	int row;
	char message[PPC4XX_EDAC_MESSAGE_SIZE];

	ppc4xx_edac_generate_message(mci, status, message, sizeof(message));

	for (row = 0; row < mci->nr_csrows; row++)
		if (ppc4xx_edac_check_bank_error(status, row))
			edac_mc_handle_ce_no_info(mci, message);
}

/**
 * ppc4xx_edac_handle_ue - handle controller uncorrectable ECC error (UE)
 * @mci: A pointer to the EDAC memory controller instance
 *       associated with the uncorrectable error being handled and
 *       reported.
 * @status: A pointer to the ECC status structure associated with
 *          the uncorrectable error being handled and reported.
 *
 * This routine handles an ibm,sdram-4xx-ddr2 controller ECC
 * uncorrectable error.
 */
static void
ppc4xx_edac_handle_ue(struct mem_ctl_info *mci,
		      const struct ppc4xx_ecc_status *status)
{
	const u64 bear = ((u64)status->bearh << 32 | status->bearl);
	const unsigned long page = bear >> PAGE_SHIFT;
	const unsigned long offset = bear & ~PAGE_MASK;
	int row;
	char message[PPC4XX_EDAC_MESSAGE_SIZE];

	ppc4xx_edac_generate_message(mci, status, message, sizeof(message));

	for (row = 0; row < mci->nr_csrows; row++)
		if (ppc4xx_edac_check_bank_error(status, row))
			edac_mc_handle_ue(mci, page, offset, row, message);
}

/**
 * ppc4xx_edac_check - check controller for ECC errors
 * @mci: A pointer to the EDAC memory controller instance
 *       associated with the ibm,sdram-4xx-ddr2 controller being
 *       checked.
 *
 * This routine is used to check and post ECC errors and is called by
 * both the EDAC polling thread and this driver's CE and UE interrupt
 * handler.
 */
static void
ppc4xx_edac_check(struct mem_ctl_info *mci)
{
#ifdef DEBUG
	static unsigned int count;
#endif
	struct ppc4xx_ecc_status status;

	ppc4xx_ecc_get_status(mci, &status);

#ifdef DEBUG
	if (count++ % 30 == 0)
		ppc4xx_ecc_dump_status(mci, &status);
#endif

	if (status.ecces & SDRAM_ECCES_UE)
		ppc4xx_edac_handle_ue(mci, &status);

	if (status.ecces & SDRAM_ECCES_CE)
		ppc4xx_edac_handle_ce(mci, &status);

	ppc4xx_ecc_clear_status(mci, &status);
}

/**
 * ppc4xx_edac_isr - SEC (CE) and DED (UE) interrupt service routine
 * @irq:    The virtual interrupt number being serviced.
 * @dev_id: A pointer to the EDAC memory controller instance
 *          associated with the interrupt being handled.
 *
 * This routine implements the interrupt handler for both correctable
 * (CE) and uncorrectable (UE) ECC errors for the ibm,sdram-4xx-ddr2
 * controller. It simply calls through to the same routine used during
 * polling to check, report and clear the ECC status.
 *
 * Unconditionally returns IRQ_HANDLED.
 */
static irqreturn_t
ppc4xx_edac_isr(int irq, void *dev_id)
{
	struct mem_ctl_info *mci = dev_id;

	ppc4xx_edac_check(mci);

	return IRQ_HANDLED;
}

/**
 * ppc4xx_edac_get_dtype - return the controller memory width
 * @mcopt1: The 32-bit Memory Controller Option 1 register value
 *          currently set for the controller, from which the width
 *          is derived.
 *
 * This routine returns the EDAC device type width appropriate for the
 * current controller configuration.
 *
 * TODO: This needs to be conditioned dynamically through feature
 * flags or some such when other controller variants are supported as
 * the 405EX[r] is 16-/32-bit and the others are 32-/64-bit with the
 * 16- and 64-bit field definition/value/enumeration (b1) overloaded
 * among them.
 *
 * Returns a device type width enumeration.
 */
static enum dev_type __devinit
ppc4xx_edac_get_dtype(u32 mcopt1)
{
	switch (mcopt1 & SDRAM_MCOPT1_WDTH_MASK) {
	case SDRAM_MCOPT1_WDTH_16:
		return DEV_X2;
	case SDRAM_MCOPT1_WDTH_32:
		return DEV_X4;
	default:
		return DEV_UNKNOWN;
	}
}

/**
 * ppc4xx_edac_get_mtype - return controller memory type
 * @mcopt1: The 32-bit Memory Controller Option 1 register value
 *          currently set for the controller, from which the memory type
 *          is derived.
 *
 * This routine returns the EDAC memory type appropriate for the
 * current controller configuration.
 *
 * Returns a memory type enumeration.
 */
static enum mem_type __devinit
ppc4xx_edac_get_mtype(u32 mcopt1)
{
	bool rden = ((mcopt1 & SDRAM_MCOPT1_RDEN_MASK) == SDRAM_MCOPT1_RDEN);

	switch (mcopt1 & SDRAM_MCOPT1_DDR_TYPE_MASK) {
	case SDRAM_MCOPT1_DDR2_TYPE:
		return rden ? MEM_RDDR2 : MEM_DDR2;
	case SDRAM_MCOPT1_DDR1_TYPE:
		return rden ? MEM_RDDR : MEM_DDR;
	default:
		return MEM_UNKNOWN;
	}
}

/**
 * ppc4xx_edac_init_csrows - initialize driver instance rows
 * @mci: A pointer to the EDAC memory controller instance
 *       associated with the ibm,sdram-4xx-ddr2 controller for which
 *       the csrows (i.e. banks/ranks) are being initialized.
 * @mcopt1: The 32-bit Memory Controller Option 1 register value
 *          currently set for the controller, from which bank width
 *          and memory typ information is derived.
 *
 * This routine initializes the virtual "chip select rows" associated
 * with the EDAC memory controller instance. An ibm,sdram-4xx-ddr2
 * controller bank/rank is mapped to a row.
 *
 * Returns 0 if OK; otherwise, -EINVAL if the memory bank size
 * configuration cannot be determined.
 */
static int __devinit
ppc4xx_edac_init_csrows(struct mem_ctl_info *mci, u32 mcopt1)
{
	const struct ppc4xx_edac_pdata *pdata = mci->pvt_info;
	int status = 0;
	enum mem_type mtype;
	enum dev_type dtype;
	enum edac_type edac_mode;
	int row;
	u32 mbxcf, size;
	static u32 ppc4xx_last_page;

	/* Establish the memory type and width */

	mtype = ppc4xx_edac_get_mtype(mcopt1);
	dtype = ppc4xx_edac_get_dtype(mcopt1);

	/* Establish EDAC mode */

	if (mci->edac_cap & EDAC_FLAG_SECDED)
		edac_mode = EDAC_SECDED;
	else if (mci->edac_cap & EDAC_FLAG_EC)
		edac_mode = EDAC_EC;
	else
		edac_mode = EDAC_NONE;

	/*
	 * Initialize each chip select row structure which correspond
	 * 1:1 with a controller bank/rank.
	 */

	for (row = 0; row < mci->nr_csrows; row++) {
		struct csrow_info *csi = &mci->csrows[row];

		/*
		 * Get the configuration settings for this
		 * row/bank/rank and skip disabled banks.
		 */

		mbxcf = mfsdram(&pdata->dcr_host, SDRAM_MBXCF(row));

		if ((mbxcf & SDRAM_MBCF_BE_MASK) != SDRAM_MBCF_BE_ENABLE)
			continue;

		/* Map the bank configuration size setting to pages. */

		size = mbxcf & SDRAM_MBCF_SZ_MASK;

		switch (size) {
		case SDRAM_MBCF_SZ_4MB:
		case SDRAM_MBCF_SZ_8MB:
		case SDRAM_MBCF_SZ_16MB:
		case SDRAM_MBCF_SZ_32MB:
		case SDRAM_MBCF_SZ_64MB:
		case SDRAM_MBCF_SZ_128MB:
		case SDRAM_MBCF_SZ_256MB:
		case SDRAM_MBCF_SZ_512MB:
		case SDRAM_MBCF_SZ_1GB:
		case SDRAM_MBCF_SZ_2GB:
		case SDRAM_MBCF_SZ_4GB:
		case SDRAM_MBCF_SZ_8GB:
			csi->nr_pages = SDRAM_MBCF_SZ_TO_PAGES(size);
			break;
		default:
			ppc4xx_edac_mc_printk(KERN_ERR, mci,
					      "Unrecognized memory bank %d "
					      "size 0x%08x\n",
					      row, SDRAM_MBCF_SZ_DECODE(size));
			status = -EINVAL;
			goto done;
		}

		csi->first_page = ppc4xx_last_page;
		csi->last_page	= csi->first_page + csi->nr_pages - 1;
		csi->page_mask	= 0;

		/*
		 * It's unclear exactly what grain should be set to
		 * here. The SDRAM_ECCES register allows resolution of
		 * an error down to a nibble which would potentially
		 * argue for a grain of '1' byte, even though we only
		 * know the associated address for uncorrectable
		 * errors. This value is not used at present for
		 * anything other than error reporting so getting it
		 * wrong should be of little consequence. Other
		 * possible values would be the PLB width (16), the
		 * page size (PAGE_SIZE) or the memory width (2 or 4).
		 */

		csi->grain	= 1;

		csi->mtype	= mtype;
		csi->dtype	= dtype;

		csi->edac_mode	= edac_mode;

		ppc4xx_last_page += csi->nr_pages;
	}

 done:
	return status;
}

/**
 * ppc4xx_edac_mc_init - initialize driver instance
 * @mci: A pointer to the EDAC memory controller instance being
 *       initialized.
 * @op: A pointer to the OpenFirmware device tree node associated
 *      with the controller this EDAC instance is bound to.
 * @dcr_host: A pointer to the DCR data containing the DCR mapping
 *            for this controller instance.
 * @mcopt1: The 32-bit Memory Controller Option 1 register value
 *          currently set for the controller, from which ECC capabilities
 *          and scrub mode are derived.
 *
 * This routine performs initialization of the EDAC memory controller
 * instance and related driver-private data associated with the
 * ibm,sdram-4xx-ddr2 memory controller the instance is bound to.
 *
 * Returns 0 if OK; otherwise, < 0 on error.
 */
static int __devinit
ppc4xx_edac_mc_init(struct mem_ctl_info *mci,
		    struct platform_device *op,
		    const dcr_host_t *dcr_host,
		    u32 mcopt1)
{
	int status = 0;
	const u32 memcheck = (mcopt1 & SDRAM_MCOPT1_MCHK_MASK);
	struct ppc4xx_edac_pdata *pdata = NULL;
	const struct device_node *np = op->dev.of_node;

	if (of_match_device(ppc4xx_edac_match, &op->dev) == NULL)
		return -EINVAL;

	/* Initial driver pointers and private data */

	mci->dev		= &op->dev;

	dev_set_drvdata(mci->dev, mci);

	pdata			= mci->pvt_info;

	pdata->dcr_host		= *dcr_host;
	pdata->irqs.sec		= NO_IRQ;
	pdata->irqs.ded		= NO_IRQ;

	/* Initialize controller capabilities and configuration */

	mci->mtype_cap		= (MEM_FLAG_DDR | MEM_FLAG_RDDR |
				   MEM_FLAG_DDR2 | MEM_FLAG_RDDR2);

	mci->edac_ctl_cap	= (EDAC_FLAG_NONE |
				   EDAC_FLAG_EC |
				   EDAC_FLAG_SECDED);

	mci->scrub_cap		= SCRUB_NONE;
	mci->scrub_mode		= SCRUB_NONE;

	/*
	 * Update the actual capabilites based on the MCOPT1[MCHK]
	 * settings. Scrubbing is only useful if reporting is enabled.
	 */

	switch (memcheck) {
	case SDRAM_MCOPT1_MCHK_CHK:
		mci->edac_cap	= EDAC_FLAG_EC;
		break;
	case SDRAM_MCOPT1_MCHK_CHK_REP:
		mci->edac_cap	= (EDAC_FLAG_EC | EDAC_FLAG_SECDED);
		mci->scrub_mode	= SCRUB_SW_SRC;
		break;
	default:
		mci->edac_cap	= EDAC_FLAG_NONE;
		break;
	}

	/* Initialize strings */

	mci->mod_name		= PPC4XX_EDAC_MODULE_NAME;
	mci->mod_ver		= PPC4XX_EDAC_MODULE_REVISION;
	mci->ctl_name		= match->compatible,
	mci->dev_name		= np->full_name;

	/* Initialize callbacks */

	mci->edac_check		= ppc4xx_edac_check;
	mci->ctl_page_to_phys	= NULL;

	/* Initialize chip select rows */

	status = ppc4xx_edac_init_csrows(mci, mcopt1);

	if (status)
		ppc4xx_edac_mc_printk(KERN_ERR, mci,
				      "Failed to initialize rows!\n");

	return status;
}

/**
 * ppc4xx_edac_register_irq - setup and register controller interrupts
 * @op: A pointer to the OpenFirmware device tree node associated
 *      with the controller this EDAC instance is bound to.
 * @mci: A pointer to the EDAC memory controller instance
 *       associated with the ibm,sdram-4xx-ddr2 controller for which
 *       interrupts are being registered.
 *
 * This routine parses the correctable (CE) and uncorrectable error (UE)
 * interrupts from the device tree node and maps and assigns them to
 * the associated EDAC memory controller instance.
 *
 * Returns 0 if OK; otherwise, -ENODEV if the interrupts could not be
 * mapped and assigned.
 */
static int __devinit
ppc4xx_edac_register_irq(struct platform_device *op, struct mem_ctl_info *mci)
{
	int status = 0;
	int ded_irq, sec_irq;
	struct ppc4xx_edac_pdata *pdata = mci->pvt_info;
	struct device_node *np = op->dev.of_node;

	ded_irq = irq_of_parse_and_map(np, INTMAP_ECCDED_INDEX);
	sec_irq = irq_of_parse_and_map(np, INTMAP_ECCSEC_INDEX);

	if (ded_irq == NO_IRQ || sec_irq == NO_IRQ) {
		ppc4xx_edac_mc_printk(KERN_ERR, mci,
				      "Unable to map interrupts.\n");
		status = -ENODEV;
		goto fail;
	}

	status = request_irq(ded_irq,
			     ppc4xx_edac_isr,
			     IRQF_DISABLED,
			     "[EDAC] MC ECCDED",
			     mci);

	if (status < 0) {
		ppc4xx_edac_mc_printk(KERN_ERR, mci,
				      "Unable to request irq %d for ECC DED",
				      ded_irq);
		status = -ENODEV;
		goto fail1;
	}

	status = request_irq(sec_irq,
			     ppc4xx_edac_isr,
			     IRQF_DISABLED,
			     "[EDAC] MC ECCSEC",
			     mci);

	if (status < 0) {
		ppc4xx_edac_mc_printk(KERN_ERR, mci,
				      "Unable to request irq %d for ECC SEC",
				      sec_irq);
		status = -ENODEV;
		goto fail2;
	}

	ppc4xx_edac_mc_printk(KERN_INFO, mci, "ECCDED irq is %d\n", ded_irq);
	ppc4xx_edac_mc_printk(KERN_INFO, mci, "ECCSEC irq is %d\n", sec_irq);

	pdata->irqs.ded = ded_irq;
	pdata->irqs.sec = sec_irq;

	return 0;

 fail2:
	free_irq(sec_irq, mci);

 fail1:
	free_irq(ded_irq, mci);

 fail:
	return status;
}

/**
 * ppc4xx_edac_map_dcrs - locate and map controller registers
 * @np: A pointer to the device tree node containing the DCR
 *      resources to map.
 * @dcr_host: A pointer to the DCR data to populate with the
 *            DCR mapping.
 *
 * This routine attempts to locate in the device tree and map the DCR
 * register resources associated with the controller's indirect DCR
 * address and data windows.
 *
 * Returns 0 if the DCRs were successfully mapped; otherwise, < 0 on
 * error.
 */
static int __devinit
ppc4xx_edac_map_dcrs(const struct device_node *np, dcr_host_t *dcr_host)
{
	unsigned int dcr_base, dcr_len;

	if (np == NULL || dcr_host == NULL)
		return -EINVAL;

	/* Get the DCR resource extent and sanity check the values. */

	dcr_base = dcr_resource_start(np, 0);
	dcr_len = dcr_resource_len(np, 0);

	if (dcr_base == 0 || dcr_len == 0) {
		ppc4xx_edac_printk(KERN_ERR,
				   "Failed to obtain DCR property.\n");
		return -ENODEV;
	}

	if (dcr_len != SDRAM_DCR_RESOURCE_LEN) {
		ppc4xx_edac_printk(KERN_ERR,
				   "Unexpected DCR length %d, expected %d.\n",
				   dcr_len, SDRAM_DCR_RESOURCE_LEN);
		return -ENODEV;
	}

	/*  Attempt to map the DCR extent. */

	*dcr_host = dcr_map(np, dcr_base, dcr_len);

	if (!DCR_MAP_OK(*dcr_host)) {
		ppc4xx_edac_printk(KERN_INFO, "Failed to map DCRs.\n");
		    return -ENODEV;
	}

	return 0;
}

/**
 * ppc4xx_edac_probe - check controller and bind driver
 * @op: A pointer to the OpenFirmware device tree node associated
 *      with the controller being probed for driver binding.
 *
 * This routine probes a specific ibm,sdram-4xx-ddr2 controller
 * instance for binding with the driver.
 *
 * Returns 0 if the controller instance was successfully bound to the
 * driver; otherwise, < 0 on error.
 */
static int __devinit ppc4xx_edac_probe(struct platform_device *op)
{
	int status = 0;
	u32 mcopt1, memcheck;
	dcr_host_t dcr_host;
	const struct device_node *np = op->dev.of_node;
	struct mem_ctl_info *mci = NULL;
	static int ppc4xx_edac_instance;

	/*
	 * At this point, we only support the controller realized on
	 * the AMCC PPC 405EX[r]. Reject anything else.
	 */

	if (!of_device_is_compatible(np, "ibm,sdram-405ex") &&
	    !of_device_is_compatible(np, "ibm,sdram-405exr")) {
		ppc4xx_edac_printk(KERN_NOTICE,
				   "Only the PPC405EX[r] is supported.\n");
		return -ENODEV;
	}

	/*
	 * Next, get the DCR property and attempt to map it so that we
	 * can probe the controller.
	 */

	status = ppc4xx_edac_map_dcrs(np, &dcr_host);

	if (status)
		return status;

	/*
	 * First determine whether ECC is enabled at all. If not,
	 * there is no useful checking or monitoring that can be done
	 * for this controller.
	 */

	mcopt1 = mfsdram(&dcr_host, SDRAM_MCOPT1);
	memcheck = (mcopt1 & SDRAM_MCOPT1_MCHK_MASK);

	if (memcheck == SDRAM_MCOPT1_MCHK_NON) {
		ppc4xx_edac_printk(KERN_INFO, "%s: No ECC memory detected or "
				   "ECC is disabled.\n", np->full_name);
		status = -ENODEV;
		goto done;
	}

	/*
	 * At this point, we know ECC is enabled, allocate an EDAC
	 * controller instance and perform the appropriate
	 * initialization.
	 */

	mci = edac_mc_alloc(sizeof(struct ppc4xx_edac_pdata),
			    ppc4xx_edac_nr_csrows,
			    ppc4xx_edac_nr_chans,
			    ppc4xx_edac_instance);

	if (mci == NULL) {
		ppc4xx_edac_printk(KERN_ERR, "%s: "
				   "Failed to allocate EDAC MC instance!\n",
				   np->full_name);
		status = -ENOMEM;
		goto done;
	}

	status = ppc4xx_edac_mc_init(mci, op, &dcr_host, mcopt1);

	if (status) {
		ppc4xx_edac_mc_printk(KERN_ERR, mci,
				      "Failed to initialize instance!\n");
		goto fail;
	}

	/*
	 * We have a valid, initialized EDAC instance bound to the
	 * controller. Attempt to register it with the EDAC subsystem
	 * and, if necessary, register interrupts.
	 */

	if (edac_mc_add_mc(mci)) {
		ppc4xx_edac_mc_printk(KERN_ERR, mci,
				      "Failed to add instance!\n");
		status = -ENODEV;
		goto fail;
	}

	if (edac_op_state == EDAC_OPSTATE_INT) {
		status = ppc4xx_edac_register_irq(op, mci);

		if (status)
			goto fail1;
	}

	ppc4xx_edac_instance++;

	return 0;

 fail1:
	edac_mc_del_mc(mci->dev);

 fail:
	edac_mc_free(mci);

 done:
	return status;
}

/**
 * ppc4xx_edac_remove - unbind driver from controller
 * @op: A pointer to the OpenFirmware device tree node associated
 *      with the controller this EDAC instance is to be unbound/removed
 *      from.
 *
 * This routine unbinds the EDAC memory controller instance associated
 * with the specified ibm,sdram-4xx-ddr2 controller described by the
 * OpenFirmware device tree node passed as a parameter.
 *
 * Unconditionally returns 0.
 */
static int
ppc4xx_edac_remove(struct platform_device *op)
{
	struct mem_ctl_info *mci = dev_get_drvdata(&op->dev);
	struct ppc4xx_edac_pdata *pdata = mci->pvt_info;

	if (edac_op_state == EDAC_OPSTATE_INT) {
		free_irq(pdata->irqs.sec, mci);
		free_irq(pdata->irqs.ded, mci);
	}

	dcr_unmap(pdata->dcr_host, SDRAM_DCR_RESOURCE_LEN);

	edac_mc_del_mc(mci->dev);
	edac_mc_free(mci);

	return 0;
}

/**
 * ppc4xx_edac_opstate_init - initialize EDAC reporting method
 *
 * This routine ensures that the EDAC memory controller reporting
 * method is mapped to a sane value as the EDAC core defines the value
 * to EDAC_OPSTATE_INVAL by default. We don't call the global
 * opstate_init as that defaults to polling and we want interrupt as
 * the default.
 */
static inline void __init
ppc4xx_edac_opstate_init(void)
{
	switch (edac_op_state) {
	case EDAC_OPSTATE_POLL:
	case EDAC_OPSTATE_INT:
		break;
	default:
		edac_op_state = EDAC_OPSTATE_INT;
		break;
	}

	ppc4xx_edac_printk(KERN_INFO, "Reporting type: %s\n",
			   ((edac_op_state == EDAC_OPSTATE_POLL) ?
			    EDAC_OPSTATE_POLL_STR :
			    ((edac_op_state == EDAC_OPSTATE_INT) ?
			     EDAC_OPSTATE_INT_STR :
			     EDAC_OPSTATE_UNKNOWN_STR)));
}

/**
 * ppc4xx_edac_init - driver/module insertion entry point
 *
 * This routine is the driver/module insertion entry point. It
 * initializes the EDAC memory controller reporting state and
 * registers the driver as an OpenFirmware device tree platform
 * driver.
 */
static int __init
ppc4xx_edac_init(void)
{
	ppc4xx_edac_printk(KERN_INFO, PPC4XX_EDAC_MODULE_REVISION "\n");

	ppc4xx_edac_opstate_init();

	return platform_driver_register(&ppc4xx_edac_driver);
}

/**
 * ppc4xx_edac_exit - driver/module removal entry point
 *
 * This routine is the driver/module removal entry point. It
 * unregisters the driver as an OpenFirmware device tree platform
 * driver.
 */
static void __exit
ppc4xx_edac_exit(void)
{
	platform_driver_unregister(&ppc4xx_edac_driver);
}

module_init(ppc4xx_edac_init);
module_exit(ppc4xx_edac_exit);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Grant Erickson <gerickson@nuovations.com>");
MODULE_DESCRIPTION("EDAC MC Driver for the PPC4xx IBM DDR2 Memory Controller");
module_param(edac_op_state, int, 0444);
MODULE_PARM_DESC(edac_op_state, "EDAC Error Reporting State: "
		 "0=" EDAC_OPSTATE_POLL_STR ", 2=" EDAC_OPSTATE_INT_STR);