summaryrefslogtreecommitdiff
path: root/drivers/mailbox/zynqmp-ipi-mailbox.c
blob: 7fa533e80dd97edb18b191ba0aec582586e701ae (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
// SPDX-License-Identifier: GPL-2.0
/*
 * Xilinx Inter Processor Interrupt(IPI) Mailbox Driver
 *
 * Copyright (C) 2018 Xilinx, Inc.
 */

#include <linux/arm-smccc.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mailbox_controller.h>
#include <linux/mailbox/zynqmp-ipi-message.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>

/* IPI agent ID any */
#define IPI_ID_ANY 0xFFUL

/* indicate if ZynqMP IPI mailbox driver uses SMC calls or HVC calls */
#define USE_SMC 0
#define USE_HVC 1

/* Default IPI SMC function IDs */
#define SMC_IPI_MAILBOX_OPEN		0x82001000U
#define SMC_IPI_MAILBOX_RELEASE		0x82001001U
#define SMC_IPI_MAILBOX_STATUS_ENQUIRY	0x82001002U
#define SMC_IPI_MAILBOX_NOTIFY		0x82001003U
#define SMC_IPI_MAILBOX_ACK		0x82001004U
#define SMC_IPI_MAILBOX_ENABLE_IRQ	0x82001005U
#define SMC_IPI_MAILBOX_DISABLE_IRQ	0x82001006U

/* IPI SMC Macros */
#define IPI_SMC_ENQUIRY_DIRQ_MASK	0x00000001UL /* Flag to indicate if
						      * notification interrupt
						      * to be disabled.
						      */
#define IPI_SMC_ACK_EIRQ_MASK		0x00000001UL /* Flag to indicate if
						      * notification interrupt
						      * to be enabled.
						      */

/* IPI mailbox status */
#define IPI_MB_STATUS_IDLE		0
#define IPI_MB_STATUS_SEND_PENDING	1
#define IPI_MB_STATUS_RECV_PENDING	2

#define IPI_MB_CHNL_TX	0 /* IPI mailbox TX channel */
#define IPI_MB_CHNL_RX	1 /* IPI mailbox RX channel */

/**
 * struct zynqmp_ipi_mchan - Description of a Xilinx ZynqMP IPI mailbox channel
 * @is_opened: indicate if the IPI channel is opened
 * @req_buf: local to remote request buffer start address
 * @resp_buf: local to remote response buffer start address
 * @req_buf_size: request buffer size
 * @resp_buf_size: response buffer size
 * @rx_buf: receive buffer to pass received message to client
 * @chan_type: channel type
 */
struct zynqmp_ipi_mchan {
	int is_opened;
	void __iomem *req_buf;
	void __iomem *resp_buf;
	void *rx_buf;
	size_t req_buf_size;
	size_t resp_buf_size;
	unsigned int chan_type;
};

/**
 * struct zynqmp_ipi_mbox - Description of a ZynqMP IPI mailbox
 *                          platform data.
 * @pdata:		  pointer to the IPI private data
 * @dev:                  device pointer corresponding to the Xilinx ZynqMP
 *                        IPI mailbox
 * @remote_id:            remote IPI agent ID
 * @mbox:                 mailbox Controller
 * @mchans:               array for channels, tx channel and rx channel.
 * @irq:                  IPI agent interrupt ID
 */
struct zynqmp_ipi_mbox {
	struct zynqmp_ipi_pdata *pdata;
	struct device dev;
	u32 remote_id;
	struct mbox_controller mbox;
	struct zynqmp_ipi_mchan mchans[2];
};

/**
 * struct zynqmp_ipi_pdata - Description of z ZynqMP IPI agent platform data.
 *
 * @dev:                  device pointer corresponding to the Xilinx ZynqMP
 *                        IPI agent
 * @irq:                  IPI agent interrupt ID
 * @method:               IPI SMC or HVC is going to be used
 * @local_id:             local IPI agent ID
 * @num_mboxes:           number of mailboxes of this IPI agent
 * @ipi_mboxes:           IPI mailboxes of this IPI agent
 */
struct zynqmp_ipi_pdata {
	struct device *dev;
	int irq;
	unsigned int method;
	u32 local_id;
	int num_mboxes;
	struct zynqmp_ipi_mbox ipi_mboxes[] __counted_by(num_mboxes);
};

static struct device_driver zynqmp_ipi_mbox_driver = {
	.owner = THIS_MODULE,
	.name = "zynqmp-ipi-mbox",
};

static void zynqmp_ipi_fw_call(struct zynqmp_ipi_mbox *ipi_mbox,
			       unsigned long a0, unsigned long a3,
			       struct arm_smccc_res *res)
{
	struct zynqmp_ipi_pdata *pdata = ipi_mbox->pdata;
	unsigned long a1, a2;

	a1 = pdata->local_id;
	a2 = ipi_mbox->remote_id;
	if (pdata->method == USE_SMC)
		arm_smccc_smc(a0, a1, a2, a3, 0, 0, 0, 0, res);
	else
		arm_smccc_hvc(a0, a1, a2, a3, 0, 0, 0, 0, res);
}

/**
 * zynqmp_ipi_interrupt - Interrupt handler for IPI notification
 *
 * @irq:  Interrupt number
 * @data: ZynqMP IPI mailbox platform data.
 *
 * Return: -EINVAL if there is no instance
 * IRQ_NONE if the interrupt is not ours.
 * IRQ_HANDLED if the rx interrupt was successfully handled.
 */
static irqreturn_t zynqmp_ipi_interrupt(int irq, void *data)
{
	struct zynqmp_ipi_pdata *pdata = data;
	struct mbox_chan *chan;
	struct zynqmp_ipi_mbox *ipi_mbox;
	struct zynqmp_ipi_mchan *mchan;
	struct zynqmp_ipi_message *msg;
	u64 arg0, arg3;
	struct arm_smccc_res res;
	int ret, i, status = IRQ_NONE;

	(void)irq;
	arg0 = SMC_IPI_MAILBOX_STATUS_ENQUIRY;
	arg3 = IPI_SMC_ENQUIRY_DIRQ_MASK;
	for (i = 0; i < pdata->num_mboxes; i++) {
		ipi_mbox = &pdata->ipi_mboxes[i];
		mchan = &ipi_mbox->mchans[IPI_MB_CHNL_RX];
		chan = &ipi_mbox->mbox.chans[IPI_MB_CHNL_RX];
		zynqmp_ipi_fw_call(ipi_mbox, arg0, arg3, &res);
		ret = (int)(res.a0 & 0xFFFFFFFF);
		if (ret > 0 && ret & IPI_MB_STATUS_RECV_PENDING) {
			if (mchan->is_opened) {
				msg = mchan->rx_buf;
				msg->len = mchan->req_buf_size;
				memcpy_fromio(msg->data, mchan->req_buf,
					      msg->len);
				mbox_chan_received_data(chan, (void *)msg);
				status = IRQ_HANDLED;
			}
		}
	}
	return status;
}

/**
 * zynqmp_ipi_peek_data - Peek to see if there are any rx messages.
 *
 * @chan: Channel Pointer
 *
 * Return: 'true' if there is pending rx data, 'false' if there is none.
 */
static bool zynqmp_ipi_peek_data(struct mbox_chan *chan)
{
	struct device *dev = chan->mbox->dev;
	struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
	struct zynqmp_ipi_mchan *mchan = chan->con_priv;
	int ret;
	u64 arg0;
	struct arm_smccc_res res;

	if (WARN_ON(!ipi_mbox)) {
		dev_err(dev, "no platform drv data??\n");
		return false;
	}

	arg0 = SMC_IPI_MAILBOX_STATUS_ENQUIRY;
	zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
	ret = (int)(res.a0 & 0xFFFFFFFF);

	if (mchan->chan_type == IPI_MB_CHNL_TX) {
		/* TX channel, check if the message has been acked
		 * by the remote, if yes, response is available.
		 */
		if (ret < 0 || ret & IPI_MB_STATUS_SEND_PENDING)
			return false;
		else
			return true;
	} else if (ret > 0 && ret & IPI_MB_STATUS_RECV_PENDING) {
		/* RX channel, check if there is message arrived. */
		return true;
	}
	return false;
}

/**
 * zynqmp_ipi_last_tx_done - See if the last tx message is sent
 *
 * @chan: Channel pointer
 *
 * Return: 'true' is no pending tx data, 'false' if there are any.
 */
static bool zynqmp_ipi_last_tx_done(struct mbox_chan *chan)
{
	struct device *dev = chan->mbox->dev;
	struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
	struct zynqmp_ipi_mchan *mchan = chan->con_priv;
	int ret;
	u64 arg0;
	struct arm_smccc_res res;

	if (WARN_ON(!ipi_mbox)) {
		dev_err(dev, "no platform drv data??\n");
		return false;
	}

	if (mchan->chan_type == IPI_MB_CHNL_TX) {
		/* We only need to check if the message been taken
		 * by the remote in the TX channel
		 */
		arg0 = SMC_IPI_MAILBOX_STATUS_ENQUIRY;
		zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
		/* Check the SMC call status, a0 of the result */
		ret = (int)(res.a0 & 0xFFFFFFFF);
		if (ret < 0 || ret & IPI_MB_STATUS_SEND_PENDING)
			return false;
		return true;
	}
	/* Always true for the response message in RX channel */
	return true;
}

/**
 * zynqmp_ipi_send_data - Send data
 *
 * @chan: Channel Pointer
 * @data: Message Pointer
 *
 * Return: 0 if all goes good, else appropriate error messages.
 */
static int zynqmp_ipi_send_data(struct mbox_chan *chan, void *data)
{
	struct device *dev = chan->mbox->dev;
	struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
	struct zynqmp_ipi_mchan *mchan = chan->con_priv;
	struct zynqmp_ipi_message *msg = data;
	u64 arg0;
	struct arm_smccc_res res;

	if (WARN_ON(!ipi_mbox)) {
		dev_err(dev, "no platform drv data??\n");
		return -EINVAL;
	}

	if (mchan->chan_type == IPI_MB_CHNL_TX) {
		/* Send request message */
		if (msg && msg->len > mchan->req_buf_size) {
			dev_err(dev, "channel %d message length %u > max %lu\n",
				mchan->chan_type, (unsigned int)msg->len,
				mchan->req_buf_size);
			return -EINVAL;
		}
		if (msg && msg->len)
			memcpy_toio(mchan->req_buf, msg->data, msg->len);
		/* Kick IPI mailbox to send message */
		arg0 = SMC_IPI_MAILBOX_NOTIFY;
		zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
	} else {
		/* Send response message */
		if (msg && msg->len > mchan->resp_buf_size) {
			dev_err(dev, "channel %d message length %u > max %lu\n",
				mchan->chan_type, (unsigned int)msg->len,
				mchan->resp_buf_size);
			return -EINVAL;
		}
		if (msg && msg->len)
			memcpy_toio(mchan->resp_buf, msg->data, msg->len);
		arg0 = SMC_IPI_MAILBOX_ACK;
		zynqmp_ipi_fw_call(ipi_mbox, arg0, IPI_SMC_ACK_EIRQ_MASK,
				   &res);
	}
	return 0;
}

/**
 * zynqmp_ipi_startup - Startup the IPI channel
 *
 * @chan: Channel pointer
 *
 * Return: 0 if all goes good, else return corresponding error message
 */
static int zynqmp_ipi_startup(struct mbox_chan *chan)
{
	struct device *dev = chan->mbox->dev;
	struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
	struct zynqmp_ipi_mchan *mchan = chan->con_priv;
	u64 arg0;
	struct arm_smccc_res res;
	int ret = 0;
	unsigned int nchan_type;

	if (mchan->is_opened)
		return 0;

	/* If no channel has been opened, open the IPI mailbox */
	nchan_type = (mchan->chan_type + 1) % 2;
	if (!ipi_mbox->mchans[nchan_type].is_opened) {
		arg0 = SMC_IPI_MAILBOX_OPEN;
		zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
		/* Check the SMC call status, a0 of the result */
		ret = (int)(res.a0 & 0xFFFFFFFF);
		if (ret < 0) {
			dev_err(dev, "SMC to open the IPI channel failed.\n");
			return ret;
		}
		ret = 0;
	}

	/* If it is RX channel, enable the IPI notification interrupt */
	if (mchan->chan_type == IPI_MB_CHNL_RX) {
		arg0 = SMC_IPI_MAILBOX_ENABLE_IRQ;
		zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
	}
	mchan->is_opened = 1;

	return ret;
}

/**
 * zynqmp_ipi_shutdown - Shutdown the IPI channel
 *
 * @chan: Channel pointer
 */
static void zynqmp_ipi_shutdown(struct mbox_chan *chan)
{
	struct device *dev = chan->mbox->dev;
	struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
	struct zynqmp_ipi_mchan *mchan = chan->con_priv;
	u64 arg0;
	struct arm_smccc_res res;
	unsigned int chan_type;

	if (!mchan->is_opened)
		return;

	/* If it is RX channel, disable notification interrupt */
	chan_type = mchan->chan_type;
	if (chan_type == IPI_MB_CHNL_RX) {
		arg0 = SMC_IPI_MAILBOX_DISABLE_IRQ;
		zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
	}
	/* Release IPI mailbox if no other channel is opened */
	chan_type = (chan_type + 1) % 2;
	if (!ipi_mbox->mchans[chan_type].is_opened) {
		arg0 = SMC_IPI_MAILBOX_RELEASE;
		zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
	}

	mchan->is_opened = 0;
}

/* ZynqMP IPI mailbox operations */
static const struct mbox_chan_ops zynqmp_ipi_chan_ops = {
	.startup = zynqmp_ipi_startup,
	.shutdown = zynqmp_ipi_shutdown,
	.peek_data = zynqmp_ipi_peek_data,
	.last_tx_done = zynqmp_ipi_last_tx_done,
	.send_data = zynqmp_ipi_send_data,
};

/**
 * zynqmp_ipi_of_xlate - Translate of phandle to IPI mailbox channel
 *
 * @mbox: mailbox controller pointer
 * @p:    phandle pointer
 *
 * Return: Mailbox channel, else return error pointer.
 */
static struct mbox_chan *zynqmp_ipi_of_xlate(struct mbox_controller *mbox,
					     const struct of_phandle_args *p)
{
	struct mbox_chan *chan;
	struct device *dev = mbox->dev;
	unsigned int chan_type;

	/* Only supports TX and RX channels */
	chan_type = p->args[0];
	if (chan_type != IPI_MB_CHNL_TX && chan_type != IPI_MB_CHNL_RX) {
		dev_err(dev, "req chnl failure: invalid chnl type %u.\n",
			chan_type);
		return ERR_PTR(-EINVAL);
	}
	chan = &mbox->chans[chan_type];
	return chan;
}

static const struct of_device_id zynqmp_ipi_of_match[] = {
	{ .compatible = "xlnx,zynqmp-ipi-mailbox" },
	{},
};
MODULE_DEVICE_TABLE(of, zynqmp_ipi_of_match);

/**
 * zynqmp_ipi_mbox_get_buf_res - Get buffer resource from the IPI dev node
 *
 * @node: IPI mbox device child node
 * @name: name of the IPI buffer
 * @res: pointer to where the resource information will be stored.
 *
 * Return: 0 for success, negative value for failure
 */
static int zynqmp_ipi_mbox_get_buf_res(struct device_node *node,
				       const char *name,
				       struct resource *res)
{
	int ret, index;

	index = of_property_match_string(node, "reg-names", name);
	if (index >= 0) {
		ret = of_address_to_resource(node, index, res);
		if (ret < 0)
			return -EINVAL;
		return 0;
	}
	return -ENODEV;
}

/**
 * zynqmp_ipi_mbox_dev_release() - release the existence of a ipi mbox dev
 *
 * @dev: the ipi mailbox device
 *
 * This is to avoid the no device release() function kernel warning.
 *
 */
static void zynqmp_ipi_mbox_dev_release(struct device *dev)
{
	(void)dev;
}

/**
 * zynqmp_ipi_mbox_probe - probe IPI mailbox resource from device node
 *
 * @ipi_mbox: pointer to IPI mailbox private data structure
 * @node: IPI mailbox device node
 *
 * Return: 0 for success, negative value for failure
 */
static int zynqmp_ipi_mbox_probe(struct zynqmp_ipi_mbox *ipi_mbox,
				 struct device_node *node)
{
	struct zynqmp_ipi_mchan *mchan;
	struct mbox_chan *chans;
	struct mbox_controller *mbox;
	struct resource res;
	struct device *dev, *mdev;
	const char *name;
	int ret;

	dev = ipi_mbox->pdata->dev;
	/* Initialize dev for IPI mailbox */
	ipi_mbox->dev.parent = dev;
	ipi_mbox->dev.release = NULL;
	ipi_mbox->dev.of_node = node;
	dev_set_name(&ipi_mbox->dev, "%s", of_node_full_name(node));
	dev_set_drvdata(&ipi_mbox->dev, ipi_mbox);
	ipi_mbox->dev.release = zynqmp_ipi_mbox_dev_release;
	ipi_mbox->dev.driver = &zynqmp_ipi_mbox_driver;
	ret = device_register(&ipi_mbox->dev);
	if (ret) {
		dev_err(dev, "Failed to register ipi mbox dev.\n");
		put_device(&ipi_mbox->dev);
		return ret;
	}
	mdev = &ipi_mbox->dev;

	mchan = &ipi_mbox->mchans[IPI_MB_CHNL_TX];
	name = "local_request_region";
	ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res);
	if (!ret) {
		mchan->req_buf_size = resource_size(&res);
		mchan->req_buf = devm_ioremap(mdev, res.start,
					      mchan->req_buf_size);
		if (!mchan->req_buf) {
			dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
			return -ENOMEM;
		}
	} else if (ret != -ENODEV) {
		dev_err(mdev, "Unmatched resource %s, %d.\n", name, ret);
		return ret;
	}

	name = "remote_response_region";
	ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res);
	if (!ret) {
		mchan->resp_buf_size = resource_size(&res);
		mchan->resp_buf = devm_ioremap(mdev, res.start,
					       mchan->resp_buf_size);
		if (!mchan->resp_buf) {
			dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
			return -ENOMEM;
		}
	} else if (ret != -ENODEV) {
		dev_err(mdev, "Unmatched resource %s.\n", name);
		return ret;
	}
	mchan->rx_buf = devm_kzalloc(mdev,
				     mchan->resp_buf_size +
				     sizeof(struct zynqmp_ipi_message),
				     GFP_KERNEL);
	if (!mchan->rx_buf)
		return -ENOMEM;

	mchan = &ipi_mbox->mchans[IPI_MB_CHNL_RX];
	name = "remote_request_region";
	ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res);
	if (!ret) {
		mchan->req_buf_size = resource_size(&res);
		mchan->req_buf = devm_ioremap(mdev, res.start,
					      mchan->req_buf_size);
		if (!mchan->req_buf) {
			dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
			return -ENOMEM;
		}
	} else if (ret != -ENODEV) {
		dev_err(mdev, "Unmatched resource %s.\n", name);
		return ret;
	}

	name = "local_response_region";
	ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res);
	if (!ret) {
		mchan->resp_buf_size = resource_size(&res);
		mchan->resp_buf = devm_ioremap(mdev, res.start,
					       mchan->resp_buf_size);
		if (!mchan->resp_buf) {
			dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
			return -ENOMEM;
		}
	} else if (ret != -ENODEV) {
		dev_err(mdev, "Unmatched resource %s.\n", name);
		return ret;
	}
	mchan->rx_buf = devm_kzalloc(mdev,
				     mchan->resp_buf_size +
				     sizeof(struct zynqmp_ipi_message),
				     GFP_KERNEL);
	if (!mchan->rx_buf)
		return -ENOMEM;

	/* Get the IPI remote agent ID */
	ret = of_property_read_u32(node, "xlnx,ipi-id", &ipi_mbox->remote_id);
	if (ret < 0) {
		dev_err(dev, "No IPI remote ID is specified.\n");
		return ret;
	}

	mbox = &ipi_mbox->mbox;
	mbox->dev = mdev;
	mbox->ops = &zynqmp_ipi_chan_ops;
	mbox->num_chans = 2;
	mbox->txdone_irq = false;
	mbox->txdone_poll = true;
	mbox->txpoll_period = 5;
	mbox->of_xlate = zynqmp_ipi_of_xlate;
	chans = devm_kzalloc(mdev, 2 * sizeof(*chans), GFP_KERNEL);
	if (!chans)
		return -ENOMEM;
	mbox->chans = chans;
	chans[IPI_MB_CHNL_TX].con_priv = &ipi_mbox->mchans[IPI_MB_CHNL_TX];
	chans[IPI_MB_CHNL_RX].con_priv = &ipi_mbox->mchans[IPI_MB_CHNL_RX];
	ipi_mbox->mchans[IPI_MB_CHNL_TX].chan_type = IPI_MB_CHNL_TX;
	ipi_mbox->mchans[IPI_MB_CHNL_RX].chan_type = IPI_MB_CHNL_RX;
	ret = devm_mbox_controller_register(mdev, mbox);
	if (ret)
		dev_err(mdev,
			"Failed to register mbox_controller(%d)\n", ret);
	else
		dev_info(mdev,
			 "Registered ZynqMP IPI mbox with TX/RX channels.\n");
	return ret;
}

/**
 * zynqmp_ipi_free_mboxes - Free IPI mailboxes devices
 *
 * @pdata: IPI private data
 */
static void zynqmp_ipi_free_mboxes(struct zynqmp_ipi_pdata *pdata)
{
	struct zynqmp_ipi_mbox *ipi_mbox;
	int i;

	i = pdata->num_mboxes;
	for (; i >= 0; i--) {
		ipi_mbox = &pdata->ipi_mboxes[i];
		if (ipi_mbox->dev.parent) {
			mbox_controller_unregister(&ipi_mbox->mbox);
			if (device_is_registered(&ipi_mbox->dev))
				device_unregister(&ipi_mbox->dev);
		}
	}
}

static int zynqmp_ipi_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct device_node *nc, *np = pdev->dev.of_node;
	struct zynqmp_ipi_pdata *pdata;
	struct zynqmp_ipi_mbox *mbox;
	int num_mboxes, ret = -EINVAL;

	num_mboxes = of_get_available_child_count(np);
	if (num_mboxes == 0) {
		dev_err(dev, "mailbox nodes not available\n");
		return -EINVAL;
	}

	pdata = devm_kzalloc(dev, struct_size(pdata, ipi_mboxes, num_mboxes),
			     GFP_KERNEL);
	if (!pdata)
		return -ENOMEM;
	pdata->dev = dev;

	/* Get the IPI local agents ID */
	ret = of_property_read_u32(np, "xlnx,ipi-id", &pdata->local_id);
	if (ret < 0) {
		dev_err(dev, "No IPI local ID is specified.\n");
		return ret;
	}

	pdata->num_mboxes = num_mboxes;

	mbox = pdata->ipi_mboxes;
	for_each_available_child_of_node(np, nc) {
		mbox->pdata = pdata;
		ret = zynqmp_ipi_mbox_probe(mbox, nc);
		if (ret) {
			of_node_put(nc);
			dev_err(dev, "failed to probe subdev.\n");
			ret = -EINVAL;
			goto free_mbox_dev;
		}
		mbox++;
	}

	/* IPI IRQ */
	ret = platform_get_irq(pdev, 0);
	if (ret < 0)
		goto free_mbox_dev;

	pdata->irq = ret;
	ret = devm_request_irq(dev, pdata->irq, zynqmp_ipi_interrupt,
			       IRQF_SHARED, dev_name(dev), pdata);
	if (ret) {
		dev_err(dev, "IRQ %d is not requested successfully.\n",
			pdata->irq);
		goto free_mbox_dev;
	}

	platform_set_drvdata(pdev, pdata);
	return ret;

free_mbox_dev:
	zynqmp_ipi_free_mboxes(pdata);
	return ret;
}

static int zynqmp_ipi_remove(struct platform_device *pdev)
{
	struct zynqmp_ipi_pdata *pdata;

	pdata = platform_get_drvdata(pdev);
	zynqmp_ipi_free_mboxes(pdata);

	return 0;
}

static struct platform_driver zynqmp_ipi_driver = {
	.probe = zynqmp_ipi_probe,
	.remove = zynqmp_ipi_remove,
	.driver = {
		   .name = "zynqmp-ipi",
		   .of_match_table = of_match_ptr(zynqmp_ipi_of_match),
	},
};

static int __init zynqmp_ipi_init(void)
{
	return platform_driver_register(&zynqmp_ipi_driver);
}
subsys_initcall(zynqmp_ipi_init);

static void __exit zynqmp_ipi_exit(void)
{
	platform_driver_unregister(&zynqmp_ipi_driver);
}
module_exit(zynqmp_ipi_exit);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Xilinx ZynqMP IPI Mailbox driver");
MODULE_AUTHOR("Xilinx Inc.");