aboutsummaryrefslogtreecommitdiffstats
path: root/arch/powerpc/sysdev/qe_lib/qe.c
blob: 818e763f826509b78efdcd2ca216e395b8a52c43 (plain) (blame)
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
/*
 * Copyright (C) 2006-2010 Freescale Semicondutor, Inc. All rights reserved.
 *
 * Authors: 	Shlomi Gridish <gridish@freescale.com>
 * 		Li Yang <leoli@freescale.com>
 * Based on cpm2_common.c from Dan Malek (dmalek@jlc.net)
 *
 * Description:
 * General Purpose functions for the global management of the
 * QUICC Engine (QE).
 *
 * 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;  either version 2 of the  License, or (at your
 * option) any later version.
 */
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/bootmem.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/crc32.h>
#include <linux/mod_devicetable.h>
#include <linux/of_platform.h>
#include <asm/irq.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/immap_qe.h>
#include <asm/qe.h>
#include <asm/prom.h>
#include <asm/rheap.h>

static void qe_snums_init(void);
static int qe_sdma_init(void);

static DEFINE_SPINLOCK(qe_lock);
DEFINE_SPINLOCK(cmxgcr_lock);
EXPORT_SYMBOL(cmxgcr_lock);

/* QE snum state */
enum qe_snum_state {
	QE_SNUM_STATE_USED,
	QE_SNUM_STATE_FREE
};

/* QE snum */
struct qe_snum {
	u8 num;
	enum qe_snum_state state;
};

/* We allocate this here because it is used almost exclusively for
 * the communication processor devices.
 */
struct qe_immap __iomem *qe_immr;
EXPORT_SYMBOL(qe_immr);

static struct qe_snum snums[QE_NUM_OF_SNUM];	/* Dynamically allocated SNUMs */
static unsigned int qe_num_of_snum;

static phys_addr_t qebase = -1;

phys_addr_t get_qe_base(void)
{
	struct device_node *qe;
	int size;
	const u32 *prop;

	if (qebase != -1)
		return qebase;

	qe = of_find_compatible_node(NULL, NULL, "fsl,qe");
	if (!qe) {
		qe = of_find_node_by_type(NULL, "qe");
		if (!qe)
			return qebase;
	}

	prop = of_get_property(qe, "reg", &size);
	if (prop && size >= sizeof(*prop))
		qebase = of_translate_address(qe, prop);
	of_node_put(qe);

	return qebase;
}

EXPORT_SYMBOL(get_qe_base);

void qe_reset(void)
{
	if (qe_immr == NULL)
		qe_immr = ioremap(get_qe_base(), QE_IMMAP_SIZE);

	qe_snums_init();

	qe_issue_cmd(QE_RESET, QE_CR_SUBBLOCK_INVALID,
		     QE_CR_PROTOCOL_UNSPECIFIED, 0);

	/* Reclaim the MURAM memory for our use. */
	qe_muram_init();

	if (qe_sdma_init())
		panic("sdma init failed!");
}

int qe_issue_cmd(u32 cmd, u32 device, u8 mcn_protocol, u32 cmd_input)
{
	unsigned long flags;
	u8 mcn_shift = 0, dev_shift = 0;
	u32 ret;

	spin_lock_irqsave(&qe_lock, flags);
	if (cmd == QE_RESET) {
		out_be32(&qe_immr->cp.cecr, (u32) (cmd | QE_CR_FLG));
	} else {
		if (cmd == QE_ASSIGN_PAGE) {
			/* Here device is the SNUM, not sub-block */
			dev_shift = QE_CR_SNUM_SHIFT;
		} else if (cmd == QE_ASSIGN_RISC) {
			/* Here device is the SNUM, and mcnProtocol is
			 * e_QeCmdRiscAssignment value */
			dev_shift = QE_CR_SNUM_SHIFT;
			mcn_shift = QE_CR_MCN_RISC_ASSIGN_SHIFT;
		} else {
			if (device == QE_CR_SUBBLOCK_USB)
				mcn_shift = QE_CR_MCN_USB_SHIFT;
			else
				mcn_shift = QE_CR_MCN_NORMAL_SHIFT;
		}

		out_be32(&qe_immr->cp.cecdr, cmd_input);
		out_be32(&qe_immr->cp.cecr,
			 (cmd | QE_CR_FLG | ((u32) device << dev_shift) | (u32)
			  mcn_protocol << mcn_shift));
	}

	/* wait for the QE_CR_FLG to clear */
	ret = spin_event_timeout((in_be32(&qe_immr->cp.cecr) & QE_CR_FLG) == 0,
			   100, 0);
	/* On timeout (e.g. failure), the expression will be false (ret == 0),
	   otherwise it will be true (ret == 1). */
	spin_unlock_irqrestore(&qe_lock, flags);

	return ret == 1;
}
EXPORT_SYMBOL(qe_issue_cmd);

/* Set a baud rate generator. This needs lots of work. There are
 * 16 BRGs, which can be connected to the QE channels or output
 * as clocks. The BRGs are in two different block of internal
 * memory mapped space.
 * The BRG clock is the QE clock divided by 2.
 * It was set up long ago during the initial boot phase and is
 * is given to us.
 * Baud rate clocks are zero-based in the driver code (as that maps
 * to port numbers). Documentation uses 1-based numbering.
 */
static unsigned int brg_clk = 0;

unsigned int qe_get_brg_clk(void)
{
	struct device_node *qe;
	int size;
	const u32 *prop;

	if (brg_clk)
		return brg_clk;

	qe = of_find_compatible_node(NULL, NULL, "fsl,qe");
	if (!qe) {
		qe = of_find_node_by_type(NULL, "qe");
		if (!qe)
			return brg_clk;
	}

	prop = of_get_property(qe, "brg-frequency", &size);
	if (prop && size == sizeof(*prop))
		brg_clk = *prop;

	of_node_put(qe);

	return brg_clk;
}
EXPORT_SYMBOL(qe_get_brg_clk);

/* Program the BRG to the given sampling rate and multiplier
 *
 * @brg: the BRG, QE_BRG1 - QE_BRG16
 * @rate: the desired sampling rate
 * @multiplier: corresponds to the value programmed in GUMR_L[RDCR] or
 * GUMR_L[TDCR].  E.g., if this BRG is the RX clock, and GUMR_L[RDCR]=01,
 * then 'multiplier' should be 8.
 */
int qe_setbrg(enum qe_clock brg, unsigned int rate, unsigned int multiplier)
{
	u32 divisor, tempval;
	u32 div16 = 0;

	if ((brg < QE_BRG1) || (brg > QE_BRG16))
		return -EINVAL;

	divisor = qe_get_brg_clk() / (rate * multiplier);

	if (divisor > QE_BRGC_DIVISOR_MAX + 1) {
		div16 = QE_BRGC_DIV16;
		divisor /= 16;
	}

	/* Errata QE_General4, which affects some MPC832x and MPC836x SOCs, says
	   that the BRG divisor must be even if you're not using divide-by-16
	   mode. */
	if (!div16 && (divisor & 1) && (divisor > 3))
		divisor++;

	tempval = ((divisor - 1) << QE_BRGC_DIVISOR_SHIFT) |
		QE_BRGC_ENABLE | div16;

	out_be32(&qe_immr->brg.brgc[brg - QE_BRG1], tempval);

	return 0;
}
EXPORT_SYMBOL(qe_setbrg);

/* Convert a string to a QE clock source enum
 *
 * This function takes a string, typically from a property in the device
 * tree, and returns the corresponding "enum qe_clock" value.
*/
enum qe_clock qe_clock_source(const char *source)
{
	unsigned int i;

	if (strcasecmp(source, "none") == 0)
		return QE_CLK_NONE;

	if (strncasecmp(source, "brg", 3) == 0) {
		i = simple_strtoul(source + 3, NULL, 10);
		if ((i >= 1) && (i <= 16))
			return (QE_BRG1 - 1) + i;
		else
			return QE_CLK_DUMMY;
	}

	if (strncasecmp(source, "clk", 3) == 0) {
		i = simple_strtoul(source + 3, NULL, 10);
		if ((i >= 1) && (i <= 24))
			return (QE_CLK1 - 1) + i;
		else
			return QE_CLK_DUMMY;
	}

	return QE_CLK_DUMMY;
}
EXPORT_SYMBOL(qe_clock_source);

/* Initialize SNUMs (thread serial numbers) according to
 * QE Module Control chapter, SNUM table
 */
static void qe_snums_init(void)
{
	int i;
	static const u8 snum_init_76[] = {
		0x04, 0x05, 0x0C, 0x0D, 0x14, 0x15, 0x1C, 0x1D,
		0x24, 0x25, 0x2C, 0x2D, 0x34, 0x35, 0x88, 0x89,
		0x98, 0x99, 0xA8, 0xA9, 0xB8, 0xB9, 0xC8, 0xC9,
		0xD8, 0xD9, 0xE8, 0xE9, 0x44, 0x45, 0x4C, 0x4D,
		0x54, 0x55, 0x5C, 0x5D, 0x64, 0x65, 0x6C, 0x6D,
		0x74, 0x75, 0x7C, 0x7D, 0x84, 0x85, 0x8C, 0x8D,
		0x94, 0x95, 0x9C, 0x9D, 0xA4, 0xA5, 0xAC, 0xAD,
		0xB4, 0xB5, 0xBC, 0xBD, 0xC4, 0xC5, 0xCC, 0xCD,
		0xD4, 0xD5, 0xDC, 0xDD, 0xE4, 0xE5, 0xEC, 0xED,
		0xF4, 0xF5, 0xFC, 0xFD,
	};
	static const u8 snum_init_46[] = {
		0x04, 0x05, 0x0C, 0x0D, 0x14, 0x15, 0x1C, 0x1D,
		0x24, 0x25, 0x2C, 0x2D, 0x34, 0x35, 0x88, 0x89,
		0x98, 0x99, 0xA8, 0xA9, 0xB8, 0xB9, 0xC8, 0xC9,
		0xD8, 0xD9, 0xE8, 0xE9, 0x08, 0x09, 0x18, 0x19,
		0x28, 0x29, 0x38, 0x39, 0x48, 0x49, 0x58, 0x59,
		0x68, 0x69, 0x78, 0x79, 0x80, 0x81,
	};
	static const u8 *snum_init;

	qe_num_of_snum = qe_get_num_of_snums();

	if (qe_num_of_snum == 76)
		snum_init = snum_init_76;
	else
		snum_init = snum_init_46;

	for (i = 0; i < qe_num_of_snum; i++) {
		snums[i].num = snum_init[i];
		snums[i].state = QE_SNUM_STATE_FREE;
	}
}

int qe_get_snum(void)
{
	unsigned long flags;
	int snum = -EBUSY;
	int i;

	spin_lock_irqsave(&qe_lock, flags);
	for (i = 0; i < qe_num_of_snum; i++) {
		if (snums[i].state == QE_SNUM_STATE_FREE) {
			snums[i].state = QE_SNUM_STATE_USED;
			snum = snums[i].num;
			break;
		}
	}
	spin_unlock_irqrestore(&qe_lock, flags);

	return snum;
}
EXPORT_SYMBOL(qe_get_snum);

void qe_put_snum(u8 snum)
{
	int i;

	for (i = 0; i < qe_num_of_snum; i++) {
		if (snums[i].num == snum) {
			snums[i].state = QE_SNUM_STATE_FREE;
			break;
		}
	}
}
EXPORT_SYMBOL(qe_put_snum);

static int qe_sdma_init(void)
{
	struct sdma __iomem *sdma = &qe_immr->sdma;
	static unsigned long sdma_buf_offset = (unsigned long)-ENOMEM;

	if (!sdma)
		return -ENODEV;

	/* allocate 2 internal temporary buffers (512 bytes size each) for
	 * the SDMA */
	if (IS_ERR_VALUE(sdma_buf_offset)) {
		sdma_buf_offset = qe_muram_alloc(512 * 2, 4096);
		if (IS_ERR_VALUE(sdma_buf_offset))
			return -ENOMEM;
	}

	out_be32(&sdma->sdebcr, (u32) sdma_buf_offset & QE_SDEBCR_BA_MASK);
 	out_be32(&sdma->sdmr, (QE_SDMR_GLB_1_MSK |
 					(0x1 << QE_SDMR_CEN_SHIFT)));

	return 0;
}

/* The maximum number of RISCs we support */
#define MAX_QE_RISC     4

/* Firmware information stored here for qe_get_firmware_info() */
static struct qe_firmware_info qe_firmware_info;

/*
 * Set to 1 if QE firmware has been uploaded, and therefore
 * qe_firmware_info contains valid data.
 */
static int qe_firmware_uploaded;

/*
 * Upload a QE microcode
 *
 * This function is a worker function for qe_upload_firmware().  It does
 * the actual uploading of the microcode.
 */
static void qe_upload_microcode(const void *base,
	const struct qe_microcode *ucode)
{
	const __be32 *code = base + be32_to_cpu(ucode->code_offset);
	unsigned int i;

	if (ucode->major || ucode->minor || ucode->revision)
		printk(KERN_INFO "qe-firmware: "
			"uploading microcode '%s' version %u.%u.%u\n",
			ucode->id, ucode->major, ucode->minor, ucode->revision);
	else
		printk(KERN_INFO "qe-firmware: "
			"uploading microcode '%s'\n", ucode->id);

	/* Use auto-increment */
	out_be32(&qe_immr->iram.iadd, be32_to_cpu(ucode->iram_offset) |
		QE_IRAM_IADD_AIE | QE_IRAM_IADD_BADDR);

	for (i = 0; i < be32_to_cpu(ucode->count); i++)
		out_be32(&qe_immr->iram.idata, be32_to_cpu(code[i]));
}

/*
 * Upload a microcode to the I-RAM at a specific address.
 *
 * See Documentation/powerpc/qe_firmware.txt for information on QE microcode
 * uploading.
 *
 * Currently, only version 1 is supported, so the 'version' field must be
 * set to 1.
 *
 * The SOC model and revision are not validated, they are only displayed for
 * informational purposes.
 *
 * 'calc_size' is the calculated size, in bytes, of the firmware structure and
 * all of the microcode structures, minus the CRC.
 *
 * 'length' is the size that the structure says it is, including the CRC.
 */
int qe_upload_firmware(const struct qe_firmware *firmware)
{
	unsigned int i;
	unsigned int j;
	u32 crc;
	size_t calc_size = sizeof(struct qe_firmware);
	size_t length;
	const struct qe_header *hdr;

	if (!firmware) {
		printk(KERN_ERR "qe-firmware: invalid pointer\n");
		return -EINVAL;
	}

	hdr = &firmware->header;
	length = be32_to_cpu(hdr->length);

	/* Check the magic */
	if ((hdr->magic[0] != 'Q') || (hdr->magic[1] != 'E') ||
	    (hdr->magic[2] != 'F')) {
		printk(KERN_ERR "qe-firmware: not a microcode\n");
		return -EPERM;
	}

	/* Check the version */
	if (hdr->version != 1) {
		printk(KERN_ERR "qe-firmware: unsupported version\n");
		return -EPERM;
	}

	/* Validate some of the fields */
	if ((firmware->count < 1) || (firmware->count > MAX_QE_RISC)) {
		printk(KERN_ERR "qe-firmware: invalid data\n");
		return -EINVAL;
	}

	/* Validate the length and check if there's a CRC */
	calc_size += (firmware->count - 1) * sizeof(struct qe_microcode);

	for (i = 0; i < firmware->count; i++)
		/*
		 * For situations where the second RISC uses the same microcode
		 * as the first, the 'code_offset' and 'count' fields will be
		 * zero, so it's okay to add those.
		 */
		calc_size += sizeof(__be32) *
			be32_to_cpu(firmware->microcode[i].count);

	/* Validate the length */
	if (length != calc_size + sizeof(__be32)) {
		printk(KERN_ERR "qe-firmware: invalid length\n");
		return -EPERM;
	}

	/* Validate the CRC */
	crc = be32_to_cpu(*(__be32 *)((void *)firmware + calc_size));
	if (crc != crc32(0, firmware, calc_size)) {
		printk(KERN_ERR "qe-firmware: firmware CRC is invalid\n");
		return -EIO;
	}

	/*
	 * If the microcode calls for it, split the I-RAM.
	 */
	if (!firmware->split)
		setbits16(&qe_immr->cp.cercr, QE_CP_CERCR_CIR);

	if (firmware->soc.model)
		printk(KERN_INFO
			"qe-firmware: firmware '%s' for %u V%u.%u\n",
			firmware->id, be16_to_cpu(firmware->soc.model),
			firmware->soc.major, firmware->soc.minor);
	else
		printk(KERN_INFO "qe-firmware: firmware '%s'\n",
			firmware->id);

	/*
	 * The QE only supports one microcode per RISC, so clear out all the
	 * saved microcode information and put in the new.
	 */
	memset(&qe_firmware_info, 0, sizeof(qe_firmware_info));
	strcpy(qe_firmware_info.id, firmware->id);
	qe_firmware_info.extended_modes = firmware->extended_modes;
	memcpy(qe_firmware_info.vtraps, firmware->vtraps,
		sizeof(firmware->vtraps));

	/* Loop through each microcode. */
	for (i = 0; i < firmware->count; i++) {
		const struct qe_microcode *ucode = &firmware->microcode[i];

		/* Upload a microcode if it's present */
		if (ucode->code_offset)
			qe_upload_microcode(firmware, ucode);

		/* Program the traps for this processor */
		for (j = 0; j < 16; j++) {
			u32 trap = be32_to_cpu(ucode->traps[j]);

			if (trap)
				out_be32(&qe_immr->rsp[i].tibcr[j], trap);
		}

		/* Enable traps */
		out_be32(&qe_immr->rsp[i].eccr, be32_to_cpu(ucode->eccr));
	}

	qe_firmware_uploaded = 1;

	return 0;
}
EXPORT_SYMBOL(qe_upload_firmware);

/*
 * Get info on the currently-loaded firmware
 *
 * This function also checks the device tree to see if the boot loader has
 * uploaded a firmware already.
 */
struct qe_firmware_info *qe_get_firmware_info(void)
{
	static int initialized;
	struct property *prop;
	struct device_node *qe;
	struct device_node *fw = NULL;
	const char *sprop;
	unsigned int i;

	/*
	 * If we haven't checked yet, and a driver hasn't uploaded a firmware
	 * yet, then check the device tree for information.
	 */
	if (qe_firmware_uploaded)
		return &qe_firmware_info;

	if (initialized)
		return NULL;

	initialized = 1;

	/*
	 * Newer device trees have an "fsl,qe" compatible property for the QE
	 * node, but we still need to support older device trees.
	*/
	qe = of_find_compatible_node(NULL, NULL, "fsl,qe");
	if (!qe) {
		qe = of_find_node_by_type(NULL, "qe");
		if (!qe)
			return NULL;
	}

	/* Find the 'firmware' child node */
	for_each_child_of_node(qe, fw) {
		if (strcmp(fw->name, "firmware") == 0)
			break;
	}

	of_node_put(qe);

	/* Did we find the 'firmware' node? */
	if (!fw)
		return NULL;

	qe_firmware_uploaded = 1;

	/* Copy the data into qe_firmware_info*/
	sprop = of_get_property(fw, "id", NULL);
	if (sprop)
		strncpy(qe_firmware_info.id, sprop,
			sizeof(qe_firmware_info.id) - 1);

	prop = of_find_property(fw, "extended-modes", NULL);
	if (prop && (prop->length == sizeof(u64))) {
		const u64 *iprop = prop->value;

		qe_firmware_info.extended_modes = *iprop;
	}

	prop = of_find_property(fw, "virtual-traps", NULL);
	if (prop && (prop->length == 32)) {
		const u32 *iprop = prop->value;

		for (i = 0; i < ARRAY_SIZE(qe_firmware_info.vtraps); i++)
			qe_firmware_info.vtraps[i] = iprop[i];
	}

	of_node_put(fw);

	return &qe_firmware_info;
}
EXPORT_SYMBOL(qe_get_firmware_info);

unsigned int qe_get_num_of_risc(void)
{
	struct device_node *qe;
	int size;
	unsigned int num_of_risc = 0;
	const u32 *prop;

	qe = of_find_compatible_node(NULL, NULL, "fsl,qe");
	if (!qe) {
		/* Older devices trees did not have an "fsl,qe"
		 * compatible property, so we need to look for
		 * the QE node by name.
		 */
		qe = of_find_node_by_type(NULL, "qe");
		if (!qe)
			return num_of_risc;
	}

	prop = of_get_property(qe, "fsl,qe-num-riscs", &size);
	if (prop && size == sizeof(*prop))
		num_of_risc = *prop;

	of_node_put(qe);

	return num_of_risc;
}
EXPORT_SYMBOL(qe_get_num_of_risc);

unsigned int qe_get_num_of_snums(void)
{
	struct device_node *qe;
	int size;
	unsigned int num_of_snums;
	const u32 *prop;

	num_of_snums = 28; /* The default number of snum for threads is 28 */
	qe = of_find_compatible_node(NULL, NULL, "fsl,qe");
	if (!qe) {
		/* Older devices trees did not have an "fsl,qe"
		 * compatible property, so we need to look for
		 * the QE node by name.
		 */
		qe = of_find_node_by_type(NULL, "qe");
		if (!qe)
			return num_of_snums;
	}

	prop = of_get_property(qe, "fsl,qe-num-snums", &size);
	if (prop && size == sizeof(*prop)) {
		num_of_snums = *prop;
		if ((num_of_snums < 28) || (num_of_snums > QE_NUM_OF_SNUM)) {
			/* No QE ever has fewer than 28 SNUMs */
			pr_err("QE: number of snum is invalid\n");
			of_node_put(qe);
			return -EINVAL;
		}
	}

	of_node_put(qe);

	return num_of_snums;
}
EXPORT_SYMBOL(qe_get_num_of_snums);

#if defined(CONFIG_SUSPEND) && defined(CONFIG_PPC_85xx)
static int qe_resume(struct platform_device *ofdev)
{
	if (!qe_alive_during_sleep())
		qe_reset();
	return 0;
}

static int qe_probe(struct platform_device *ofdev)
{
	return 0;
}

static const struct of_device_id qe_ids[] = {
	{ .compatible = "fsl,qe", },
	{ },
};

static struct platform_driver qe_driver = {
	.driver = {
		.name = "fsl-qe",
		.owner = THIS_MODULE,
		.of_match_table = qe_ids,
	},
	.probe = qe_probe,
	.resume = qe_resume,
};

static int __init qe_drv_init(void)
{
	return platform_driver_register(&qe_driver);
}
device_initcall(qe_drv_init);
#endif /* defined(CONFIG_SUSPEND) && defined(CONFIG_PPC_85xx) */