xref: /linux/drivers/mailbox/imx-mailbox.c (revision 23d66dbab84e8518943563df2ced14aaab28b77a)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2018 Pengutronix, Oleksij Rempel <o.rempel@pengutronix.de>
4  * Copyright 2022 NXP, Peng Fan <peng.fan@nxp.com>
5  */
6 
7 #include <linux/bitfield.h>
8 #include <linux/clk.h>
9 #include <linux/firmware/imx/ipc.h>
10 #include <linux/firmware/imx/s4.h>
11 #include <linux/interrupt.h>
12 #include <linux/io.h>
13 #include <linux/iopoll.h>
14 #include <linux/jiffies.h>
15 #include <linux/kernel.h>
16 #include <linux/mailbox_controller.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/of_platform.h>
20 #include <linux/platform_device.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/suspend.h>
23 #include <linux/slab.h>
24 #include <linux/workqueue.h>
25 
26 #define IMX_MU_CHANS		24
27 /* TX0/RX0/RXDB[0-3] */
28 #define IMX_MU_SCU_CHANS	6
29 /* TX0/RX0 */
30 #define IMX_MU_S4_CHANS		2
31 #define IMX_MU_CHAN_NAME_SIZE	32
32 
33 #define IMX_MU_V2_PAR_OFF	0x4
34 #define IMX_MU_V2_TR_MASK	GENMASK(7, 0)
35 #define IMX_MU_V2_RR_MASK	GENMASK(15, 8)
36 
37 #define IMX_MU_SECO_TX_TOUT (msecs_to_jiffies(3000))
38 #define IMX_MU_SECO_RX_TOUT (msecs_to_jiffies(3000))
39 
40 /* Please not change TX & RX */
41 enum imx_mu_chan_type {
42 	IMX_MU_TYPE_TX		= 0, /* Tx */
43 	IMX_MU_TYPE_RX		= 1, /* Rx */
44 	IMX_MU_TYPE_TXDB	= 2, /* Tx doorbell */
45 	IMX_MU_TYPE_RXDB	= 3, /* Rx doorbell */
46 	IMX_MU_TYPE_RST		= 4, /* Reset */
47 	IMX_MU_TYPE_TXDB_V2	= 5, /* Tx doorbell with S/W ACK */
48 };
49 
50 enum imx_mu_xcr {
51 	IMX_MU_CR,
52 	IMX_MU_GIER,
53 	IMX_MU_GCR,
54 	IMX_MU_TCR,
55 	IMX_MU_RCR,
56 	IMX_MU_xCR_MAX,
57 };
58 
59 enum imx_mu_xsr {
60 	IMX_MU_SR,
61 	IMX_MU_GSR,
62 	IMX_MU_TSR,
63 	IMX_MU_RSR,
64 	IMX_MU_xSR_MAX,
65 };
66 
67 struct imx_sc_rpc_msg_max {
68 	struct imx_sc_rpc_msg hdr;
69 	u32 data[30];
70 };
71 
72 struct imx_s4_rpc_msg_max {
73 	struct imx_s4_rpc_msg hdr;
74 	u32 data[254];
75 };
76 
77 struct imx_mu_con_priv {
78 	unsigned int		idx;
79 	char			irq_desc[IMX_MU_CHAN_NAME_SIZE];
80 	enum imx_mu_chan_type	type;
81 	struct mbox_chan	*chan;
82 	struct work_struct 	txdb_work;
83 	bool			shutdown;
84 };
85 
86 struct imx_mu_priv {
87 	struct device		*dev;
88 	void __iomem		*base;
89 	void			*msg;
90 	raw_spinlock_t		xcr_lock; /* control register lock */
91 
92 	struct mbox_controller	mbox;
93 	struct mbox_chan	mbox_chans[IMX_MU_CHANS];
94 
95 	struct imx_mu_con_priv  con_priv[IMX_MU_CHANS];
96 	const struct imx_mu_dcfg	*dcfg;
97 	struct clk		*clk;
98 	int			irq[IMX_MU_CHANS];
99 	bool			suspend;
100 	bool			side_b;
101 
102 	u32			xcr[IMX_MU_xCR_MAX];
103 	u32			num_tr;
104 	u32			num_rr;
105 };
106 
107 enum imx_mu_type {
108 	IMX_MU_V1,
109 	IMX_MU_V2 = BIT(1),
110 	IMX_MU_V2_S4 = BIT(15),
111 	IMX_MU_V2_IRQ = BIT(16),
112 };
113 
114 struct imx_mu_dcfg {
115 	int (*tx)(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp, void *data);
116 	int (*rx)(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp);
117 	int (*rxdb)(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp);
118 	int (*init)(struct imx_mu_priv *priv);
119 	enum imx_mu_type type;
120 	u32	xTR;		/* Transmit Register0 */
121 	u32	xRR;		/* Receive Register0 */
122 	u32	xSR[IMX_MU_xSR_MAX];	/* Status Registers */
123 	u32	xCR[IMX_MU_xCR_MAX];	/* Control Registers */
124 	bool	skip_suspend_flag;
125 };
126 
127 #define IMX_MU_xSR_GIPn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(28 + (3 - (x))))
128 #define IMX_MU_xSR_RFn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(24 + (3 - (x))))
129 #define IMX_MU_xSR_TEn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(20 + (3 - (x))))
130 
131 /* General Purpose Interrupt Enable */
132 #define IMX_MU_xCR_GIEn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(28 + (3 - (x))))
133 /* Receive Interrupt Enable */
134 #define IMX_MU_xCR_RIEn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(24 + (3 - (x))))
135 /* Transmit Interrupt Enable */
136 #define IMX_MU_xCR_TIEn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(20 + (3 - (x))))
137 /* General Purpose Interrupt Request */
138 #define IMX_MU_xCR_GIRn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(16 + (3 - (x))))
139 /* MU reset */
140 #define IMX_MU_xCR_RST(type)	(type & IMX_MU_V2 ? BIT(0) : BIT(5))
141 #define IMX_MU_xSR_RST(type)	(type & IMX_MU_V2 ? BIT(0) : BIT(7))
142 
143 
144 static struct imx_mu_priv *to_imx_mu_priv(struct mbox_controller *mbox)
145 {
146 	return container_of(mbox, struct imx_mu_priv, mbox);
147 }
148 
149 static void imx_mu_write(struct imx_mu_priv *priv, u32 val, u32 offs)
150 {
151 	iowrite32(val, priv->base + offs);
152 }
153 
154 static u32 imx_mu_read(struct imx_mu_priv *priv, u32 offs)
155 {
156 	return ioread32(priv->base + offs);
157 }
158 
159 static int imx_mu_tx_waiting_write(struct imx_mu_priv *priv, u32 val, u32 idx)
160 {
161 	u64 timeout_time = get_jiffies_64() + IMX_MU_SECO_TX_TOUT;
162 	u32 status;
163 	u32 can_write;
164 
165 	dev_dbg(priv->dev, "Trying to write %.8x to idx %d\n", val, idx);
166 
167 	do {
168 		status = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_TSR]);
169 		can_write = status & IMX_MU_xSR_TEn(priv->dcfg->type, idx % 4);
170 	} while (!can_write && time_is_after_jiffies64(timeout_time));
171 
172 	if (!can_write) {
173 		dev_err(priv->dev, "timeout trying to write %.8x at %d(%.8x)\n",
174 			val, idx, status);
175 		return -ETIME;
176 	}
177 
178 	imx_mu_write(priv, val, priv->dcfg->xTR + (idx % 4) * 4);
179 
180 	return 0;
181 }
182 
183 static int imx_mu_rx_waiting_read(struct imx_mu_priv *priv, u32 *val, u32 idx)
184 {
185 	u64 timeout_time = get_jiffies_64() + IMX_MU_SECO_RX_TOUT;
186 	u32 status;
187 	u32 can_read;
188 
189 	dev_dbg(priv->dev, "Trying to read from idx %d\n", idx);
190 
191 	do {
192 		status = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_RSR]);
193 		can_read = status & IMX_MU_xSR_RFn(priv->dcfg->type, idx % 4);
194 	} while (!can_read && time_is_after_jiffies64(timeout_time));
195 
196 	if (!can_read) {
197 		dev_err(priv->dev, "timeout trying to read idx %d (%.8x)\n",
198 			idx, status);
199 		return -ETIME;
200 	}
201 
202 	*val = imx_mu_read(priv, priv->dcfg->xRR + (idx % 4) * 4);
203 	dev_dbg(priv->dev, "Read %.8x\n", *val);
204 
205 	return 0;
206 }
207 
208 static u32 imx_mu_xcr_rmw(struct imx_mu_priv *priv, enum imx_mu_xcr type, u32 set, u32 clr)
209 {
210 	u32 val;
211 
212 	guard(raw_spinlock_irqsave)(&priv->xcr_lock);
213 
214 	val = imx_mu_read(priv, priv->dcfg->xCR[type]);
215 	val &= ~clr;
216 	val |= set;
217 	imx_mu_write(priv, val, priv->dcfg->xCR[type]);
218 
219 	return val;
220 }
221 
222 static void imx_mu_xcr_clr_shut(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp,
223 				enum imx_mu_xcr type, u32 clr)
224 {
225 	u32 val;
226 
227 	guard(raw_spinlock_irqsave)(&priv->xcr_lock);
228 	cp->shutdown = true;
229 
230 	val = imx_mu_read(priv, priv->dcfg->xCR[type]);
231 	val &= ~clr;
232 	imx_mu_write(priv, val, priv->dcfg->xCR[type]);
233 }
234 
235 static void imx_mu_xcr_set_act(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp,
236 			       enum imx_mu_xcr type, u32 set)
237 {
238 	u32 val;
239 
240 	guard(raw_spinlock_irqsave)(&priv->xcr_lock);
241 	if (!cp->shutdown) {
242 		val = imx_mu_read(priv, priv->dcfg->xCR[type]);
243 		val |= set;
244 		imx_mu_write(priv, val, priv->dcfg->xCR[type]);
245 	}
246 }
247 
248 static int imx_mu_generic_tx(struct imx_mu_priv *priv,
249 			     struct imx_mu_con_priv *cp,
250 			     void *data)
251 {
252 	u32 *arg = data;
253 	u32 val;
254 	int ret, count;
255 
256 	ret = 0;
257 	switch (cp->type) {
258 	case IMX_MU_TYPE_TX:
259 		imx_mu_write(priv, *arg, priv->dcfg->xTR + cp->idx * 4);
260 		imx_mu_xcr_rmw(priv, IMX_MU_TCR, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx), 0);
261 		break;
262 	case IMX_MU_TYPE_TXDB:
263 		imx_mu_xcr_rmw(priv, IMX_MU_GCR, IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx), 0);
264 		queue_work(system_bh_wq, &cp->txdb_work);
265 		break;
266 	case IMX_MU_TYPE_TXDB_V2:
267 		imx_mu_write(priv, IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx),
268 			     priv->dcfg->xCR[IMX_MU_GCR]);
269 		ret = -ETIMEDOUT;
270 		count = 0;
271 		while (ret && (count < 10)) {
272 			ret =
273 			readl_poll_timeout(priv->base + priv->dcfg->xCR[IMX_MU_GCR], val,
274 					   !(val & IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx)),
275 					   0, 10000);
276 
277 			if (ret) {
278 				dev_warn_ratelimited(priv->dev,
279 						     "channel type: %d timeout, %d times, retry\n",
280 						     cp->type, ++count);
281 			}
282 		}
283 		break;
284 	default:
285 		dev_warn_ratelimited(priv->dev, "Send data on wrong channel type: %d\n", cp->type);
286 		return -EINVAL;
287 	}
288 
289 	return ret;
290 }
291 
292 static int imx_mu_generic_rx(struct imx_mu_priv *priv,
293 			     struct imx_mu_con_priv *cp)
294 {
295 	u32 dat;
296 
297 	dat = imx_mu_read(priv, priv->dcfg->xRR + (cp->idx) * 4);
298 	mbox_chan_received_data(cp->chan, (void *)&dat);
299 
300 	return 0;
301 }
302 
303 static int imx_mu_generic_rxdb(struct imx_mu_priv *priv,
304 			       struct imx_mu_con_priv *cp)
305 {
306 	imx_mu_write(priv, IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx),
307 		     priv->dcfg->xSR[IMX_MU_GSR]);
308 	mbox_chan_received_data(cp->chan, NULL);
309 
310 	return 0;
311 }
312 
313 static int imx_mu_specific_tx(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp, void *data)
314 {
315 	u32 *arg = data;
316 	u32 num_tr = priv->num_tr;
317 	int i, ret;
318 	u32 xsr;
319 	u32 size, max_size;
320 
321 	if (priv->dcfg->type & IMX_MU_V2_S4) {
322 		size = ((struct imx_s4_rpc_msg_max *)data)->hdr.size;
323 		max_size = sizeof(struct imx_s4_rpc_msg_max);
324 	} else {
325 		size = ((struct imx_sc_rpc_msg_max *)data)->hdr.size;
326 		max_size = sizeof(struct imx_sc_rpc_msg_max);
327 	}
328 
329 	switch (cp->type) {
330 	case IMX_MU_TYPE_TX:
331 		/*
332 		 * msg->hdr.size specifies the number of u32 words while
333 		 * sizeof yields bytes.
334 		 */
335 
336 		if (size > max_size / 4) {
337 			/*
338 			 * The real message size can be different to
339 			 * struct imx_sc_rpc_msg_max/imx_s4_rpc_msg_max size
340 			 */
341 			dev_err(priv->dev, "Maximal message size (%u bytes) exceeded on TX; got: %i bytes\n", max_size, size << 2);
342 			return -EINVAL;
343 		}
344 
345 		for (i = 0; i < num_tr && i < size; i++)
346 			imx_mu_write(priv, *arg++, priv->dcfg->xTR + (i % num_tr) * 4);
347 		for (; i < size; i++) {
348 			ret = readl_poll_timeout(priv->base + priv->dcfg->xSR[IMX_MU_TSR],
349 						 xsr,
350 						 xsr & IMX_MU_xSR_TEn(priv->dcfg->type, i % num_tr),
351 						 0, 5 * USEC_PER_SEC);
352 			if (ret) {
353 				dev_err(priv->dev, "Send data index: %d timeout\n", i);
354 				return ret;
355 			}
356 			imx_mu_write(priv, *arg++, priv->dcfg->xTR + (i % num_tr) * 4);
357 		}
358 
359 		imx_mu_xcr_rmw(priv, IMX_MU_TCR, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx), 0);
360 		break;
361 	default:
362 		dev_warn_ratelimited(priv->dev, "Send data on wrong channel type: %d\n", cp->type);
363 		return -EINVAL;
364 	}
365 
366 	return 0;
367 }
368 
369 static int imx_mu_specific_rx(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp)
370 {
371 	u32 *data;
372 	int i, ret;
373 	u32 xsr;
374 	u32 size, max_size;
375 	u32 num_rr = priv->num_rr;
376 
377 	data = (u32 *)priv->msg;
378 
379 	*data++ = imx_mu_read(priv, priv->dcfg->xRR);
380 
381 	if (priv->dcfg->type & IMX_MU_V2_S4) {
382 		size = ((struct imx_s4_rpc_msg_max *)priv->msg)->hdr.size;
383 		max_size = sizeof(struct imx_s4_rpc_msg_max);
384 	} else {
385 		size = ((struct imx_sc_rpc_msg_max *)priv->msg)->hdr.size;
386 		max_size = sizeof(struct imx_sc_rpc_msg_max);
387 	}
388 
389 	if (size > max_size / 4) {
390 		dev_err(priv->dev, "Maximal message size (%u bytes) exceeded on RX; got: %i bytes\n", max_size, size << 2);
391 		return -EINVAL;
392 	}
393 
394 	for (i = 1; i < size; i++) {
395 		ret = readl_poll_timeout(priv->base + priv->dcfg->xSR[IMX_MU_RSR], xsr,
396 					 xsr & IMX_MU_xSR_RFn(priv->dcfg->type, i % num_rr), 0,
397 					 5 * USEC_PER_SEC);
398 		if (ret) {
399 			dev_err(priv->dev, "timeout read idx %d\n", i);
400 			return ret;
401 		}
402 		*data++ = imx_mu_read(priv, priv->dcfg->xRR + (i % num_rr) * 4);
403 	}
404 
405 	mbox_chan_received_data(cp->chan, (void *)priv->msg);
406 
407 	return 0;
408 }
409 
410 static int imx_mu_seco_tx(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp,
411 			  void *data)
412 {
413 	struct imx_sc_rpc_msg_max *msg = data;
414 	u32 *arg = data;
415 	u32 byte_size;
416 	int err;
417 	int i;
418 
419 	dev_dbg(priv->dev, "Sending message\n");
420 
421 	switch (cp->type) {
422 	case IMX_MU_TYPE_TXDB:
423 		byte_size = msg->hdr.size * sizeof(u32);
424 		if (byte_size > sizeof(*msg)) {
425 			/*
426 			 * The real message size can be different to
427 			 * struct imx_sc_rpc_msg_max size
428 			 */
429 			dev_err(priv->dev,
430 				"Exceed max msg size (%zu) on TX, got: %i\n",
431 				sizeof(*msg), byte_size);
432 			return -EINVAL;
433 		}
434 
435 		print_hex_dump_debug("from client ", DUMP_PREFIX_OFFSET, 4, 4,
436 				     data, byte_size, false);
437 
438 		/* Send first word */
439 		dev_dbg(priv->dev, "Sending header\n");
440 		imx_mu_write(priv, *arg++, priv->dcfg->xTR);
441 
442 		/* Send signaling */
443 		dev_dbg(priv->dev, "Sending signaling\n");
444 		imx_mu_xcr_rmw(priv, IMX_MU_GCR,
445 			       IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx), 0);
446 
447 		/* Send words to fill the mailbox */
448 		for (i = 1; i < 4 && i < msg->hdr.size; i++) {
449 			dev_dbg(priv->dev, "Sending word %d\n", i);
450 			imx_mu_write(priv, *arg++,
451 				     priv->dcfg->xTR + (i % 4) * 4);
452 		}
453 
454 		/* Send rest of message waiting for remote read */
455 		for (; i < msg->hdr.size; i++) {
456 			dev_dbg(priv->dev, "Sending word %d\n", i);
457 			err = imx_mu_tx_waiting_write(priv, *arg++, i);
458 			if (err) {
459 				dev_err(priv->dev, "Timeout tx %d\n", i);
460 				return err;
461 			}
462 		}
463 
464 		/* Simulate hack for mbox framework */
465 		queue_work(system_bh_wq, &cp->txdb_work);
466 
467 		break;
468 	default:
469 		dev_warn_ratelimited(priv->dev,
470 				     "Send data on wrong channel type: %d\n",
471 				     cp->type);
472 		return -EINVAL;
473 	}
474 
475 	return 0;
476 }
477 
478 static int imx_mu_seco_rxdb(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp)
479 {
480 	struct imx_sc_rpc_msg_max msg;
481 	u32 *data = (u32 *)&msg;
482 	u32 byte_size;
483 	int err = 0;
484 	int i;
485 
486 	dev_dbg(priv->dev, "Receiving message\n");
487 
488 	/* Read header */
489 	dev_dbg(priv->dev, "Receiving header\n");
490 	*data++ = imx_mu_read(priv, priv->dcfg->xRR);
491 	byte_size = msg.hdr.size * sizeof(u32);
492 	if (byte_size > sizeof(msg)) {
493 		dev_err(priv->dev, "Exceed max msg size (%zu) on RX, got: %i\n",
494 			sizeof(msg), byte_size);
495 		err = -EINVAL;
496 		goto error;
497 	}
498 
499 	/* Read message waiting they are written */
500 	for (i = 1; i < msg.hdr.size; i++) {
501 		dev_dbg(priv->dev, "Receiving word %d\n", i);
502 		err = imx_mu_rx_waiting_read(priv, data++, i);
503 		if (err) {
504 			dev_err(priv->dev, "Timeout rx %d\n", i);
505 			goto error;
506 		}
507 	}
508 
509 	/* Clear GIP */
510 	imx_mu_write(priv, IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx),
511 		     priv->dcfg->xSR[IMX_MU_GSR]);
512 
513 	print_hex_dump_debug("to client ", DUMP_PREFIX_OFFSET, 4, 4,
514 			     &msg, byte_size, false);
515 
516 	/* send data to client */
517 	dev_dbg(priv->dev, "Sending message to client\n");
518 	mbox_chan_received_data(cp->chan, (void *)&msg);
519 
520 	goto exit;
521 
522 error:
523 	mbox_chan_received_data(cp->chan, ERR_PTR(err));
524 
525 exit:
526 	return err;
527 }
528 
529 static void imx_mu_txdb_work(struct work_struct *t)
530 {
531 	struct imx_mu_con_priv *cp = from_work(cp, t, txdb_work);
532 
533 	mbox_chan_txdone(cp->chan, 0);
534 }
535 
536 static irqreturn_t imx_mu_isr_th(int irq, void *p)
537 {
538 	struct mbox_chan *chan = p;
539 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
540 	struct imx_mu_con_priv *cp = chan->con_priv;
541 
542 	switch (cp->type) {
543 	case IMX_MU_TYPE_TX:
544 		mbox_chan_txdone(chan, 0);
545 		break;
546 
547 	case IMX_MU_TYPE_RX:
548 		if (!priv->dcfg->rx(priv, cp))
549 			imx_mu_xcr_set_act(priv, cp, IMX_MU_RCR, IMX_MU_xCR_RIEn(priv->dcfg->type, cp->idx));
550 		break;
551 
552 	case IMX_MU_TYPE_RXDB:
553 		if (!priv->dcfg->rxdb(priv, cp))
554 			imx_mu_xcr_set_act(priv, cp, IMX_MU_GIER, IMX_MU_xCR_GIEn(priv->dcfg->type, cp->idx));
555 		break;
556 
557 	default:
558 		dev_warn_ratelimited(priv->dev, "Unhandled channel type %d\n",
559 				     cp->type);
560 		return IRQ_NONE;
561 	}
562 	return IRQ_HANDLED;
563 }
564 
565 static irqreturn_t imx_mu_isr(int irq, void *p)
566 {
567 	struct mbox_chan *chan = p;
568 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
569 	struct imx_mu_con_priv *cp = chan->con_priv;
570 	irqreturn_t ret = IRQ_HANDLED;
571 	u32 val, ctrl;
572 
573 	switch (cp->type) {
574 	case IMX_MU_TYPE_TX:
575 		ctrl = imx_mu_read(priv, priv->dcfg->xCR[IMX_MU_TCR]);
576 		val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_TSR]);
577 		val &= IMX_MU_xSR_TEn(priv->dcfg->type, cp->idx) &
578 			(ctrl & IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx));
579 		break;
580 	case IMX_MU_TYPE_RX:
581 		ctrl = imx_mu_read(priv, priv->dcfg->xCR[IMX_MU_RCR]);
582 		val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_RSR]);
583 		val &= IMX_MU_xSR_RFn(priv->dcfg->type, cp->idx) &
584 			(ctrl & IMX_MU_xCR_RIEn(priv->dcfg->type, cp->idx));
585 		break;
586 	case IMX_MU_TYPE_RXDB:
587 		ctrl = imx_mu_read(priv, priv->dcfg->xCR[IMX_MU_GIER]);
588 		val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_GSR]);
589 		val &= IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx) &
590 			(ctrl & IMX_MU_xCR_GIEn(priv->dcfg->type, cp->idx));
591 		break;
592 	case IMX_MU_TYPE_RST:
593 		return IRQ_NONE;
594 	default:
595 		dev_warn_ratelimited(priv->dev, "Unhandled channel type %d\n",
596 				     cp->type);
597 		return IRQ_NONE;
598 	}
599 
600 	if (!val)
601 		return IRQ_NONE;
602 
603 	if ((val == IMX_MU_xSR_TEn(priv->dcfg->type, cp->idx)) &&
604 	    (cp->type == IMX_MU_TYPE_TX)) {
605 		imx_mu_xcr_rmw(priv, IMX_MU_TCR, 0, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx));
606 		ret = IRQ_WAKE_THREAD;
607 	} else if ((val == IMX_MU_xSR_RFn(priv->dcfg->type, cp->idx)) &&
608 		   (cp->type == IMX_MU_TYPE_RX)) {
609 		imx_mu_xcr_rmw(priv, IMX_MU_RCR, 0, IMX_MU_xCR_RIEn(priv->dcfg->type, cp->idx));
610 		ret = IRQ_WAKE_THREAD;
611 	} else if ((val == IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx)) &&
612 		   (cp->type == IMX_MU_TYPE_RXDB)) {
613 		imx_mu_xcr_rmw(priv, IMX_MU_GIER, 0, IMX_MU_xCR_GIEn(priv->dcfg->type, cp->idx));
614 		ret = IRQ_WAKE_THREAD;
615 	} else {
616 		dev_warn_ratelimited(priv->dev, "Not handled interrupt\n");
617 		return IRQ_NONE;
618 	}
619 
620 	if (priv->suspend)
621 		pm_system_wakeup();
622 
623 	return ret;
624 }
625 
626 static int imx_mu_send_data(struct mbox_chan *chan, void *data)
627 {
628 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
629 	struct imx_mu_con_priv *cp = chan->con_priv;
630 
631 	return priv->dcfg->tx(priv, cp, data);
632 }
633 
634 static int imx_mu_startup(struct mbox_chan *chan)
635 {
636 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
637 	struct imx_mu_con_priv *cp = chan->con_priv;
638 	unsigned long irq_flag = IRQF_NO_THREAD;
639 	int ret;
640 
641 	pm_runtime_get_sync(priv->dev);
642 	if (cp->type == IMX_MU_TYPE_TXDB_V2)
643 		return 0;
644 
645 	if (cp->type == IMX_MU_TYPE_TXDB) {
646 		/* Tx doorbell don't have ACK support */
647 		INIT_WORK(&cp->txdb_work, imx_mu_txdb_work);
648 		return 0;
649 	}
650 
651 	/* IPC MU should be with IRQF_NO_SUSPEND set */
652 	if (!priv->dev->pm_domain)
653 		irq_flag |= IRQF_NO_SUSPEND;
654 
655 	if (!(priv->dcfg->type & IMX_MU_V2_IRQ))
656 		irq_flag |= IRQF_SHARED;
657 
658 	ret = request_threaded_irq(priv->irq[cp->type], imx_mu_isr, imx_mu_isr_th,
659 				   irq_flag, cp->irq_desc, chan);
660 	if (ret) {
661 		dev_err(priv->dev, "Unable to acquire IRQ %d\n", priv->irq[cp->type]);
662 		return ret;
663 	}
664 
665 	cp->shutdown = false;
666 	switch (cp->type) {
667 	case IMX_MU_TYPE_RX:
668 		imx_mu_xcr_rmw(priv, IMX_MU_RCR, IMX_MU_xCR_RIEn(priv->dcfg->type, cp->idx), 0);
669 		break;
670 	case IMX_MU_TYPE_RXDB:
671 		imx_mu_xcr_rmw(priv, IMX_MU_GIER, IMX_MU_xCR_GIEn(priv->dcfg->type, cp->idx), 0);
672 		break;
673 	default:
674 		break;
675 	}
676 
677 	return 0;
678 }
679 
680 static void imx_mu_shutdown(struct mbox_chan *chan)
681 {
682 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
683 	struct imx_mu_con_priv *cp = chan->con_priv;
684 	int ret;
685 	u32 sr;
686 
687 	if (cp->type == IMX_MU_TYPE_TXDB_V2) {
688 		pm_runtime_put_sync(priv->dev);
689 		return;
690 	}
691 
692 	if (cp->type == IMX_MU_TYPE_TXDB) {
693 		cancel_work_sync(&cp->txdb_work);
694 		pm_runtime_put_sync(priv->dev);
695 		return;
696 	}
697 
698 	switch (cp->type) {
699 	case IMX_MU_TYPE_TX:
700 		imx_mu_xcr_clr_shut(priv, cp, IMX_MU_TCR, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx));
701 		break;
702 	case IMX_MU_TYPE_RX:
703 		imx_mu_xcr_clr_shut(priv, cp, IMX_MU_RCR, IMX_MU_xCR_RIEn(priv->dcfg->type, cp->idx));
704 		break;
705 	case IMX_MU_TYPE_RXDB:
706 		imx_mu_xcr_clr_shut(priv, cp, IMX_MU_GIER, IMX_MU_xCR_GIEn(priv->dcfg->type, cp->idx));
707 		break;
708 	case IMX_MU_TYPE_RST:
709 		imx_mu_xcr_rmw(priv, IMX_MU_CR, IMX_MU_xCR_RST(priv->dcfg->type), 0);
710 		ret = readl_poll_timeout(priv->base + priv->dcfg->xSR[IMX_MU_SR], sr,
711 					 !(sr & IMX_MU_xSR_RST(priv->dcfg->type)), 1, 5);
712 		if (ret)
713 			dev_warn(priv->dev, "RST channel timeout\n");
714 		break;
715 	default:
716 		break;
717 	}
718 
719 	free_irq(priv->irq[cp->type], chan);
720 	pm_runtime_put_sync(priv->dev);
721 }
722 
723 static const struct mbox_chan_ops imx_mu_ops = {
724 	.send_data = imx_mu_send_data,
725 	.startup = imx_mu_startup,
726 	.shutdown = imx_mu_shutdown,
727 };
728 
729 static struct mbox_chan *imx_mu_specific_xlate(struct mbox_controller *mbox,
730 					       const struct of_phandle_args *sp)
731 {
732 	u32 type, idx, chan;
733 
734 	if (sp->args_count != 2) {
735 		dev_err(mbox->dev, "Invalid argument count %d\n", sp->args_count);
736 		return ERR_PTR(-EINVAL);
737 	}
738 
739 	type = sp->args[0]; /* channel type */
740 	idx = sp->args[1]; /* index */
741 
742 	switch (type) {
743 	case IMX_MU_TYPE_TX:
744 	case IMX_MU_TYPE_RX:
745 		if (idx != 0)
746 			dev_err(mbox->dev, "Invalid chan idx: %d\n", idx);
747 		chan = type;
748 		break;
749 	case IMX_MU_TYPE_RXDB:
750 		chan = 2 + idx;
751 		break;
752 	default:
753 		dev_err(mbox->dev, "Invalid chan type: %d\n", type);
754 		return ERR_PTR(-EINVAL);
755 	}
756 
757 	if (chan >= mbox->num_chans) {
758 		dev_err(mbox->dev, "Not supported channel number: %d. (type: %d, idx: %d)\n", chan, type, idx);
759 		return ERR_PTR(-EINVAL);
760 	}
761 
762 	return &mbox->chans[chan];
763 }
764 
765 static struct mbox_chan * imx_mu_xlate(struct mbox_controller *mbox,
766 				       const struct of_phandle_args *sp)
767 {
768 	struct mbox_chan *p_chan;
769 	u32 type, idx, chan;
770 
771 	if (sp->args_count != 2) {
772 		dev_err(mbox->dev, "Invalid argument count %d\n", sp->args_count);
773 		return ERR_PTR(-EINVAL);
774 	}
775 
776 	type = sp->args[0]; /* channel type */
777 	idx = sp->args[1]; /* index */
778 
779 	/* RST only supports 1 channel */
780 	if ((type == IMX_MU_TYPE_RST) && idx) {
781 		dev_err(mbox->dev, "Invalid RST channel %d\n", idx);
782 		return ERR_PTR(-EINVAL);
783 	}
784 
785 	chan = type * 4 + idx;
786 	if (chan >= mbox->num_chans) {
787 		dev_err(mbox->dev, "Not supported channel number: %d. (type: %d, idx: %d)\n", chan, type, idx);
788 		return ERR_PTR(-EINVAL);
789 	}
790 
791 	p_chan = &mbox->chans[chan];
792 
793 	if (type == IMX_MU_TYPE_TXDB_V2)
794 		p_chan->txdone_method = MBOX_TXDONE_BY_ACK;
795 
796 	return p_chan;
797 }
798 
799 static struct mbox_chan *imx_mu_seco_xlate(struct mbox_controller *mbox,
800 					   const struct of_phandle_args *sp)
801 {
802 	u32 type;
803 
804 	if (sp->args_count < 1) {
805 		dev_err(mbox->dev, "Invalid argument count %d\n", sp->args_count);
806 		return ERR_PTR(-EINVAL);
807 	}
808 
809 	type = sp->args[0]; /* channel type */
810 
811 	/* Only supports TXDB and RXDB */
812 	if (type == IMX_MU_TYPE_TX || type == IMX_MU_TYPE_RX) {
813 		dev_err(mbox->dev, "Invalid type: %d\n", type);
814 		return ERR_PTR(-EINVAL);
815 	}
816 
817 	return imx_mu_xlate(mbox, sp);
818 }
819 
820 static void imx_mu_get_tr_rr(struct imx_mu_priv *priv)
821 {
822 	u32 val;
823 
824 	if (priv->dcfg->type & IMX_MU_V2) {
825 		val = imx_mu_read(priv, IMX_MU_V2_PAR_OFF);
826 		priv->num_tr = FIELD_GET(IMX_MU_V2_TR_MASK, val);
827 		priv->num_rr = FIELD_GET(IMX_MU_V2_RR_MASK, val);
828 	} else {
829 		priv->num_tr = 4;
830 		priv->num_rr = 4;
831 	}
832 }
833 
834 static int imx_mu_init_generic(struct imx_mu_priv *priv)
835 {
836 	unsigned int i;
837 	unsigned int val;
838 
839 	if (priv->num_rr > 4 || priv->num_tr > 4) {
840 		WARN_ONCE(true, "%s not support TR/RR larger than 4\n", __func__);
841 		return -EOPNOTSUPP;
842 	}
843 
844 	for (i = 0; i < IMX_MU_CHANS; i++) {
845 		struct imx_mu_con_priv *cp = &priv->con_priv[i];
846 
847 		cp->idx = i % 4;
848 		cp->type = i >> 2;
849 		cp->chan = &priv->mbox_chans[i];
850 		priv->mbox_chans[i].con_priv = cp;
851 		snprintf(cp->irq_desc, sizeof(cp->irq_desc),
852 			 "%s[%i-%u]", dev_name(priv->dev), cp->type, cp->idx);
853 	}
854 
855 	priv->mbox.num_chans = IMX_MU_CHANS;
856 	priv->mbox.of_xlate = imx_mu_xlate;
857 
858 	if (priv->side_b)
859 		return 0;
860 
861 	/* Set default MU configuration */
862 	for (i = 0; i < IMX_MU_xCR_MAX; i++)
863 		imx_mu_write(priv, 0, priv->dcfg->xCR[i]);
864 
865 	/* Clear any pending GIP */
866 	val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_GSR]);
867 	imx_mu_write(priv, val, priv->dcfg->xSR[IMX_MU_GSR]);
868 
869 	/* Clear any pending RSR */
870 	for (i = 0; i < priv->num_rr; i++)
871 		imx_mu_read(priv, priv->dcfg->xRR + i * 4);
872 
873 	return 0;
874 }
875 
876 static int imx_mu_init_specific(struct imx_mu_priv *priv)
877 {
878 	unsigned int i;
879 	int num_chans = priv->dcfg->type & IMX_MU_V2_S4 ? IMX_MU_S4_CHANS : IMX_MU_SCU_CHANS;
880 
881 	for (i = 0; i < num_chans; i++) {
882 		struct imx_mu_con_priv *cp = &priv->con_priv[i];
883 
884 		cp->idx = i < 2 ? 0 : i - 2;
885 		cp->type = i < 2 ? i : IMX_MU_TYPE_RXDB;
886 		cp->chan = &priv->mbox_chans[i];
887 		priv->mbox_chans[i].con_priv = cp;
888 		snprintf(cp->irq_desc, sizeof(cp->irq_desc),
889 			 "%s[%i-%u]", dev_name(priv->dev), cp->type, cp->idx);
890 	}
891 
892 	priv->mbox.num_chans = num_chans;
893 	priv->mbox.of_xlate = imx_mu_specific_xlate;
894 
895 	/* Set default MU configuration */
896 	for (i = 0; i < IMX_MU_xCR_MAX; i++)
897 		imx_mu_write(priv, 0, priv->dcfg->xCR[i]);
898 
899 	return 0;
900 }
901 
902 static int imx_mu_init_seco(struct imx_mu_priv *priv)
903 {
904 	int ret;
905 
906 	ret = imx_mu_init_generic(priv);
907 	if (ret)
908 		return ret;
909 	priv->mbox.of_xlate = imx_mu_seco_xlate;
910 
911 	return 0;
912 }
913 
914 static int imx_mu_probe(struct platform_device *pdev)
915 {
916 	struct device *dev = &pdev->dev;
917 	struct device_node *np = dev->of_node;
918 	struct imx_mu_priv *priv;
919 	const struct imx_mu_dcfg *dcfg;
920 	int i, ret;
921 	u32 size;
922 
923 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
924 	if (!priv)
925 		return -ENOMEM;
926 
927 	priv->dev = dev;
928 
929 	priv->base = devm_platform_ioremap_resource(pdev, 0);
930 	if (IS_ERR(priv->base))
931 		return PTR_ERR(priv->base);
932 
933 	dcfg = of_device_get_match_data(dev);
934 	if (!dcfg)
935 		return -EINVAL;
936 	priv->dcfg = dcfg;
937 	if (priv->dcfg->type & IMX_MU_V2_IRQ) {
938 		priv->irq[IMX_MU_TYPE_TX] = platform_get_irq_byname(pdev, "tx");
939 		if (priv->irq[IMX_MU_TYPE_TX] < 0)
940 			return priv->irq[IMX_MU_TYPE_TX];
941 		priv->irq[IMX_MU_TYPE_RX] = platform_get_irq_byname(pdev, "rx");
942 		if (priv->irq[IMX_MU_TYPE_RX] < 0)
943 			return priv->irq[IMX_MU_TYPE_RX];
944 	} else {
945 		ret = platform_get_irq(pdev, 0);
946 		if (ret < 0)
947 			return ret;
948 
949 		for (i = 0; i < IMX_MU_CHANS; i++)
950 			priv->irq[i] = ret;
951 	}
952 
953 	if (priv->dcfg->type & IMX_MU_V2_S4)
954 		size = sizeof(struct imx_s4_rpc_msg_max);
955 	else
956 		size = sizeof(struct imx_sc_rpc_msg_max);
957 
958 	priv->msg = devm_kzalloc(dev, size, GFP_KERNEL);
959 	if (!priv->msg)
960 		return -ENOMEM;
961 
962 	priv->clk = devm_clk_get(dev, NULL);
963 	if (IS_ERR(priv->clk)) {
964 		if (PTR_ERR(priv->clk) != -ENOENT)
965 			return PTR_ERR(priv->clk);
966 
967 		priv->clk = NULL;
968 	}
969 
970 	ret = clk_prepare_enable(priv->clk);
971 	if (ret) {
972 		dev_err(dev, "Failed to enable clock\n");
973 		return ret;
974 	}
975 
976 	imx_mu_get_tr_rr(priv);
977 
978 	priv->side_b = of_property_read_bool(np, "fsl,mu-side-b");
979 
980 	ret = priv->dcfg->init(priv);
981 	if (ret) {
982 		dev_err(dev, "Failed to init MU\n");
983 		goto disable_clk;
984 	}
985 
986 	raw_spin_lock_init(&priv->xcr_lock);
987 
988 	priv->mbox.dev = dev;
989 	priv->mbox.ops = &imx_mu_ops;
990 	priv->mbox.chans = priv->mbox_chans;
991 	priv->mbox.txdone_irq = true;
992 
993 	platform_set_drvdata(pdev, priv);
994 
995 	ret = devm_pm_runtime_enable(dev);
996 	if (ret < 0)
997 		goto disable_clk;
998 
999 	ret = pm_runtime_resume_and_get(dev);
1000 	if (ret < 0)
1001 		goto disable_clk;
1002 
1003 	ret = pm_runtime_put_sync(dev);
1004 	if (ret < 0)
1005 		goto disable_clk;
1006 
1007 	clk_disable_unprepare(priv->clk);
1008 
1009 	ret = devm_mbox_controller_register(dev, &priv->mbox);
1010 	if (ret)
1011 		goto err_out;
1012 
1013 	devm_of_platform_populate(dev);
1014 
1015 	return 0;
1016 
1017 disable_clk:
1018 	clk_disable_unprepare(priv->clk);
1019 err_out:
1020 	return ret;
1021 }
1022 
1023 static void imx_mu_remove(struct platform_device *pdev)
1024 {
1025 }
1026 
1027 static const struct imx_mu_dcfg imx_mu_cfg_imx6sx = {
1028 	.tx	= imx_mu_generic_tx,
1029 	.rx	= imx_mu_generic_rx,
1030 	.rxdb	= imx_mu_generic_rxdb,
1031 	.init	= imx_mu_init_generic,
1032 	.xTR	= 0x0,
1033 	.xRR	= 0x10,
1034 	.xSR	= {0x20, 0x20, 0x20, 0x20},
1035 	.xCR	= {0x24, 0x24, 0x24, 0x24, 0x24},
1036 };
1037 
1038 static const struct imx_mu_dcfg imx_mu_cfg_imx7ulp = {
1039 	.tx	= imx_mu_generic_tx,
1040 	.rx	= imx_mu_generic_rx,
1041 	.rxdb	= imx_mu_generic_rxdb,
1042 	.init	= imx_mu_init_generic,
1043 	.xTR	= 0x20,
1044 	.xRR	= 0x40,
1045 	.xSR	= {0x60, 0x60, 0x60, 0x60},
1046 	.xCR	= {0x64, 0x64, 0x64, 0x64, 0x64},
1047 	.skip_suspend_flag = true,
1048 };
1049 
1050 static const struct imx_mu_dcfg imx_mu_cfg_imx8ulp = {
1051 	.tx	= imx_mu_generic_tx,
1052 	.rx	= imx_mu_generic_rx,
1053 	.rxdb	= imx_mu_generic_rxdb,
1054 	.init	= imx_mu_init_generic,
1055 	.type	= IMX_MU_V2,
1056 	.xTR	= 0x200,
1057 	.xRR	= 0x280,
1058 	.xSR	= {0xC, 0x118, 0x124, 0x12C},
1059 	.xCR	= {0x8, 0x110, 0x114, 0x120, 0x128},
1060 };
1061 
1062 static const struct imx_mu_dcfg imx_mu_cfg_imx8ulp_s4 = {
1063 	.tx	= imx_mu_specific_tx,
1064 	.rx	= imx_mu_specific_rx,
1065 	.init	= imx_mu_init_specific,
1066 	.type	= IMX_MU_V2 | IMX_MU_V2_S4,
1067 	.xTR	= 0x200,
1068 	.xRR	= 0x280,
1069 	.xSR	= {0xC, 0x118, 0x124, 0x12C},
1070 	.xCR	= {0x8, 0x110, 0x114, 0x120, 0x128},
1071 };
1072 
1073 static const struct imx_mu_dcfg imx_mu_cfg_imx93_s4 = {
1074 	.tx	= imx_mu_specific_tx,
1075 	.rx	= imx_mu_specific_rx,
1076 	.init	= imx_mu_init_specific,
1077 	.type	= IMX_MU_V2 | IMX_MU_V2_S4 | IMX_MU_V2_IRQ,
1078 	.xTR	= 0x200,
1079 	.xRR	= 0x280,
1080 	.xSR	= {0xC, 0x118, 0x124, 0x12C},
1081 	.xCR	= {0x8, 0x110, 0x114, 0x120, 0x128},
1082 };
1083 
1084 static const struct imx_mu_dcfg imx_mu_cfg_imx8_scu = {
1085 	.tx	= imx_mu_specific_tx,
1086 	.rx	= imx_mu_specific_rx,
1087 	.init	= imx_mu_init_specific,
1088 	.rxdb	= imx_mu_generic_rxdb,
1089 	.xTR	= 0x0,
1090 	.xRR	= 0x10,
1091 	.xSR	= {0x20, 0x20, 0x20, 0x20},
1092 	.xCR	= {0x24, 0x24, 0x24, 0x24, 0x24},
1093 };
1094 
1095 static const struct imx_mu_dcfg imx_mu_cfg_imx8_seco = {
1096 	.tx	= imx_mu_seco_tx,
1097 	.rx	= imx_mu_generic_rx,
1098 	.rxdb	= imx_mu_seco_rxdb,
1099 	.init	= imx_mu_init_seco,
1100 	.xTR	= 0x0,
1101 	.xRR	= 0x10,
1102 	.xSR	= {0x20, 0x20, 0x20, 0x20},
1103 	.xCR	= {0x24, 0x24, 0x24, 0x24, 0x24},
1104 };
1105 
1106 static const struct of_device_id imx_mu_dt_ids[] = {
1107 	{ .compatible = "fsl,imx7ulp-mu", .data = &imx_mu_cfg_imx7ulp },
1108 	{ .compatible = "fsl,imx6sx-mu", .data = &imx_mu_cfg_imx6sx },
1109 	{ .compatible = "fsl,imx8ulp-mu", .data = &imx_mu_cfg_imx8ulp },
1110 	{ .compatible = "fsl,imx8ulp-mu-s4", .data = &imx_mu_cfg_imx8ulp_s4 },
1111 	{ .compatible = "fsl,imx93-mu-s4", .data = &imx_mu_cfg_imx93_s4 },
1112 	{ .compatible = "fsl,imx95-mu", .data = &imx_mu_cfg_imx8ulp },
1113 	{ .compatible = "fsl,imx95-mu-ele", .data = &imx_mu_cfg_imx8ulp_s4 },
1114 	{ .compatible = "fsl,imx95-mu-v2x", .data = &imx_mu_cfg_imx8ulp_s4 },
1115 	{ .compatible = "fsl,imx8-mu-scu", .data = &imx_mu_cfg_imx8_scu },
1116 	{ .compatible = "fsl,imx8-mu-seco", .data = &imx_mu_cfg_imx8_seco },
1117 	{ },
1118 };
1119 MODULE_DEVICE_TABLE(of, imx_mu_dt_ids);
1120 
1121 static int __maybe_unused imx_mu_suspend_noirq(struct device *dev)
1122 {
1123 	struct imx_mu_priv *priv = dev_get_drvdata(dev);
1124 	int i;
1125 
1126 	if (!priv->clk) {
1127 		for (i = 0; i < IMX_MU_xCR_MAX; i++)
1128 			priv->xcr[i] = imx_mu_read(priv, priv->dcfg->xCR[i]);
1129 	}
1130 
1131 	if (!priv->dcfg->skip_suspend_flag)
1132 		priv->suspend = true;
1133 
1134 	return 0;
1135 }
1136 
1137 static int __maybe_unused imx_mu_resume_noirq(struct device *dev)
1138 {
1139 	struct imx_mu_priv *priv = dev_get_drvdata(dev);
1140 	int i;
1141 
1142 	/*
1143 	 * ONLY restore MU when context lost, the TIE could
1144 	 * be set during noirq resume as there is MU data
1145 	 * communication going on, and restore the saved
1146 	 * value will overwrite the TIE and cause MU data
1147 	 * send failed, may lead to system freeze. This issue
1148 	 * is observed by testing freeze mode suspend.
1149 	 */
1150 	if (!priv->clk && !imx_mu_read(priv, priv->dcfg->xCR[0])) {
1151 		for (i = 0; i < IMX_MU_xCR_MAX; i++)
1152 			imx_mu_write(priv, priv->xcr[i], priv->dcfg->xCR[i]);
1153 	}
1154 
1155 	if (!priv->dcfg->skip_suspend_flag)
1156 		priv->suspend = false;
1157 
1158 	return 0;
1159 }
1160 
1161 static int __maybe_unused imx_mu_runtime_suspend(struct device *dev)
1162 {
1163 	struct imx_mu_priv *priv = dev_get_drvdata(dev);
1164 
1165 	clk_disable_unprepare(priv->clk);
1166 
1167 	return 0;
1168 }
1169 
1170 static int __maybe_unused imx_mu_runtime_resume(struct device *dev)
1171 {
1172 	struct imx_mu_priv *priv = dev_get_drvdata(dev);
1173 	int ret;
1174 
1175 	ret = clk_prepare_enable(priv->clk);
1176 	if (ret)
1177 		dev_err(dev, "failed to enable clock\n");
1178 
1179 	return ret;
1180 }
1181 
1182 static const struct dev_pm_ops imx_mu_pm_ops = {
1183 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx_mu_suspend_noirq,
1184 				      imx_mu_resume_noirq)
1185 	SET_RUNTIME_PM_OPS(imx_mu_runtime_suspend,
1186 			   imx_mu_runtime_resume, NULL)
1187 };
1188 
1189 static struct platform_driver imx_mu_driver = {
1190 	.probe		= imx_mu_probe,
1191 	.remove		= imx_mu_remove,
1192 	.driver = {
1193 		.name	= "imx_mu",
1194 		.of_match_table = imx_mu_dt_ids,
1195 		.pm = &imx_mu_pm_ops,
1196 	},
1197 };
1198 module_platform_driver(imx_mu_driver);
1199 
1200 MODULE_AUTHOR("Oleksij Rempel <o.rempel@pengutronix.de>");
1201 MODULE_DESCRIPTION("Message Unit driver for i.MX");
1202 MODULE_LICENSE("GPL v2");
1203