xref: /linux/drivers/mailbox/imx-mailbox.c (revision e7d759f31ca295d589f7420719c311870bb3166f)
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/clk.h>
8 #include <linux/firmware/imx/ipc.h>
9 #include <linux/firmware/imx/s4.h>
10 #include <linux/interrupt.h>
11 #include <linux/io.h>
12 #include <linux/iopoll.h>
13 #include <linux/jiffies.h>
14 #include <linux/kernel.h>
15 #include <linux/mailbox_controller.h>
16 #include <linux/module.h>
17 #include <linux/of.h>
18 #include <linux/platform_device.h>
19 #include <linux/pm_runtime.h>
20 #include <linux/suspend.h>
21 #include <linux/slab.h>
22 
23 #include "mailbox.h"
24 
25 #define IMX_MU_CHANS		24
26 /* TX0/RX0/RXDB[0-3] */
27 #define IMX_MU_SCU_CHANS	6
28 /* TX0/RX0 */
29 #define IMX_MU_S4_CHANS		2
30 #define IMX_MU_CHAN_NAME_SIZE	20
31 
32 #define IMX_MU_NUM_RR		4
33 
34 #define IMX_MU_SECO_TX_TOUT (msecs_to_jiffies(3000))
35 #define IMX_MU_SECO_RX_TOUT (msecs_to_jiffies(3000))
36 
37 /* Please not change TX & RX */
38 enum imx_mu_chan_type {
39 	IMX_MU_TYPE_TX		= 0, /* Tx */
40 	IMX_MU_TYPE_RX		= 1, /* Rx */
41 	IMX_MU_TYPE_TXDB	= 2, /* Tx doorbell */
42 	IMX_MU_TYPE_RXDB	= 3, /* Rx doorbell */
43 	IMX_MU_TYPE_RST		= 4, /* Reset */
44 	IMX_MU_TYPE_TXDB_V2	= 5, /* Tx doorbell with S/W ACK */
45 };
46 
47 enum imx_mu_xcr {
48 	IMX_MU_CR,
49 	IMX_MU_GIER,
50 	IMX_MU_GCR,
51 	IMX_MU_TCR,
52 	IMX_MU_RCR,
53 	IMX_MU_xCR_MAX,
54 };
55 
56 enum imx_mu_xsr {
57 	IMX_MU_SR,
58 	IMX_MU_GSR,
59 	IMX_MU_TSR,
60 	IMX_MU_RSR,
61 	IMX_MU_xSR_MAX,
62 };
63 
64 struct imx_sc_rpc_msg_max {
65 	struct imx_sc_rpc_msg hdr;
66 	u32 data[30];
67 };
68 
69 struct imx_s4_rpc_msg_max {
70 	struct imx_s4_rpc_msg hdr;
71 	u32 data[254];
72 };
73 
74 struct imx_mu_con_priv {
75 	unsigned int		idx;
76 	char			irq_desc[IMX_MU_CHAN_NAME_SIZE];
77 	enum imx_mu_chan_type	type;
78 	struct mbox_chan	*chan;
79 	struct tasklet_struct	txdb_tasklet;
80 };
81 
82 struct imx_mu_priv {
83 	struct device		*dev;
84 	void __iomem		*base;
85 	void			*msg;
86 	spinlock_t		xcr_lock; /* control register lock */
87 
88 	struct mbox_controller	mbox;
89 	struct mbox_chan	mbox_chans[IMX_MU_CHANS];
90 
91 	struct imx_mu_con_priv  con_priv[IMX_MU_CHANS];
92 	const struct imx_mu_dcfg	*dcfg;
93 	struct clk		*clk;
94 	int			irq[IMX_MU_CHANS];
95 	bool			suspend;
96 
97 	u32 xcr[IMX_MU_xCR_MAX];
98 
99 	bool			side_b;
100 };
101 
102 enum imx_mu_type {
103 	IMX_MU_V1,
104 	IMX_MU_V2 = BIT(1),
105 	IMX_MU_V2_S4 = BIT(15),
106 	IMX_MU_V2_IRQ = BIT(16),
107 };
108 
109 struct imx_mu_dcfg {
110 	int (*tx)(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp, void *data);
111 	int (*rx)(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp);
112 	int (*rxdb)(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp);
113 	void (*init)(struct imx_mu_priv *priv);
114 	enum imx_mu_type type;
115 	u32	xTR;		/* Transmit Register0 */
116 	u32	xRR;		/* Receive Register0 */
117 	u32	xSR[IMX_MU_xSR_MAX];	/* Status Registers */
118 	u32	xCR[IMX_MU_xCR_MAX];	/* Control Registers */
119 };
120 
121 #define IMX_MU_xSR_GIPn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(28 + (3 - (x))))
122 #define IMX_MU_xSR_RFn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(24 + (3 - (x))))
123 #define IMX_MU_xSR_TEn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(20 + (3 - (x))))
124 
125 /* General Purpose Interrupt Enable */
126 #define IMX_MU_xCR_GIEn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(28 + (3 - (x))))
127 /* Receive Interrupt Enable */
128 #define IMX_MU_xCR_RIEn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(24 + (3 - (x))))
129 /* Transmit Interrupt Enable */
130 #define IMX_MU_xCR_TIEn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(20 + (3 - (x))))
131 /* General Purpose Interrupt Request */
132 #define IMX_MU_xCR_GIRn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(16 + (3 - (x))))
133 /* MU reset */
134 #define IMX_MU_xCR_RST(type)	(type & IMX_MU_V2 ? BIT(0) : BIT(5))
135 #define IMX_MU_xSR_RST(type)	(type & IMX_MU_V2 ? BIT(0) : BIT(7))
136 
137 
138 static struct imx_mu_priv *to_imx_mu_priv(struct mbox_controller *mbox)
139 {
140 	return container_of(mbox, struct imx_mu_priv, mbox);
141 }
142 
143 static void imx_mu_write(struct imx_mu_priv *priv, u32 val, u32 offs)
144 {
145 	iowrite32(val, priv->base + offs);
146 }
147 
148 static u32 imx_mu_read(struct imx_mu_priv *priv, u32 offs)
149 {
150 	return ioread32(priv->base + offs);
151 }
152 
153 static int imx_mu_tx_waiting_write(struct imx_mu_priv *priv, u32 val, u32 idx)
154 {
155 	u64 timeout_time = get_jiffies_64() + IMX_MU_SECO_TX_TOUT;
156 	u32 status;
157 	u32 can_write;
158 
159 	dev_dbg(priv->dev, "Trying to write %.8x to idx %d\n", val, idx);
160 
161 	do {
162 		status = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_TSR]);
163 		can_write = status & IMX_MU_xSR_TEn(priv->dcfg->type, idx % 4);
164 	} while (!can_write && time_is_after_jiffies64(timeout_time));
165 
166 	if (!can_write) {
167 		dev_err(priv->dev, "timeout trying to write %.8x at %d(%.8x)\n",
168 			val, idx, status);
169 		return -ETIME;
170 	}
171 
172 	imx_mu_write(priv, val, priv->dcfg->xTR + (idx % 4) * 4);
173 
174 	return 0;
175 }
176 
177 static int imx_mu_rx_waiting_read(struct imx_mu_priv *priv, u32 *val, u32 idx)
178 {
179 	u64 timeout_time = get_jiffies_64() + IMX_MU_SECO_RX_TOUT;
180 	u32 status;
181 	u32 can_read;
182 
183 	dev_dbg(priv->dev, "Trying to read from idx %d\n", idx);
184 
185 	do {
186 		status = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_RSR]);
187 		can_read = status & IMX_MU_xSR_RFn(priv->dcfg->type, idx % 4);
188 	} while (!can_read && time_is_after_jiffies64(timeout_time));
189 
190 	if (!can_read) {
191 		dev_err(priv->dev, "timeout trying to read idx %d (%.8x)\n",
192 			idx, status);
193 		return -ETIME;
194 	}
195 
196 	*val = imx_mu_read(priv, priv->dcfg->xRR + (idx % 4) * 4);
197 	dev_dbg(priv->dev, "Read %.8x\n", *val);
198 
199 	return 0;
200 }
201 
202 static u32 imx_mu_xcr_rmw(struct imx_mu_priv *priv, enum imx_mu_xcr type, u32 set, u32 clr)
203 {
204 	unsigned long flags;
205 	u32 val;
206 
207 	spin_lock_irqsave(&priv->xcr_lock, flags);
208 	val = imx_mu_read(priv, priv->dcfg->xCR[type]);
209 	val &= ~clr;
210 	val |= set;
211 	imx_mu_write(priv, val, priv->dcfg->xCR[type]);
212 	spin_unlock_irqrestore(&priv->xcr_lock, flags);
213 
214 	return val;
215 }
216 
217 static int imx_mu_generic_tx(struct imx_mu_priv *priv,
218 			     struct imx_mu_con_priv *cp,
219 			     void *data)
220 {
221 	u32 *arg = data;
222 
223 	switch (cp->type) {
224 	case IMX_MU_TYPE_TX:
225 		imx_mu_write(priv, *arg, priv->dcfg->xTR + cp->idx * 4);
226 		imx_mu_xcr_rmw(priv, IMX_MU_TCR, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx), 0);
227 		break;
228 	case IMX_MU_TYPE_TXDB:
229 		imx_mu_xcr_rmw(priv, IMX_MU_GCR, IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx), 0);
230 		tasklet_schedule(&cp->txdb_tasklet);
231 		break;
232 	case IMX_MU_TYPE_TXDB_V2:
233 		imx_mu_xcr_rmw(priv, IMX_MU_GCR, IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx), 0);
234 		break;
235 	default:
236 		dev_warn_ratelimited(priv->dev, "Send data on wrong channel type: %d\n", cp->type);
237 		return -EINVAL;
238 	}
239 
240 	return 0;
241 }
242 
243 static int imx_mu_generic_rx(struct imx_mu_priv *priv,
244 			     struct imx_mu_con_priv *cp)
245 {
246 	u32 dat;
247 
248 	dat = imx_mu_read(priv, priv->dcfg->xRR + (cp->idx) * 4);
249 	mbox_chan_received_data(cp->chan, (void *)&dat);
250 
251 	return 0;
252 }
253 
254 static int imx_mu_generic_rxdb(struct imx_mu_priv *priv,
255 			       struct imx_mu_con_priv *cp)
256 {
257 	imx_mu_write(priv, IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx),
258 		     priv->dcfg->xSR[IMX_MU_GSR]);
259 	mbox_chan_received_data(cp->chan, NULL);
260 
261 	return 0;
262 }
263 
264 static int imx_mu_specific_tx(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp, void *data)
265 {
266 	u32 *arg = data;
267 	int i, ret;
268 	u32 xsr;
269 	u32 size, max_size, num_tr;
270 
271 	if (priv->dcfg->type & IMX_MU_V2_S4) {
272 		size = ((struct imx_s4_rpc_msg_max *)data)->hdr.size;
273 		max_size = sizeof(struct imx_s4_rpc_msg_max);
274 		num_tr = 8;
275 	} else {
276 		size = ((struct imx_sc_rpc_msg_max *)data)->hdr.size;
277 		max_size = sizeof(struct imx_sc_rpc_msg_max);
278 		num_tr = 4;
279 	}
280 
281 	switch (cp->type) {
282 	case IMX_MU_TYPE_TX:
283 		/*
284 		 * msg->hdr.size specifies the number of u32 words while
285 		 * sizeof yields bytes.
286 		 */
287 
288 		if (size > max_size / 4) {
289 			/*
290 			 * The real message size can be different to
291 			 * struct imx_sc_rpc_msg_max/imx_s4_rpc_msg_max size
292 			 */
293 			dev_err(priv->dev, "Maximal message size (%u bytes) exceeded on TX; got: %i bytes\n", max_size, size << 2);
294 			return -EINVAL;
295 		}
296 
297 		for (i = 0; i < num_tr && i < size; i++)
298 			imx_mu_write(priv, *arg++, priv->dcfg->xTR + (i % num_tr) * 4);
299 		for (; i < size; i++) {
300 			ret = readl_poll_timeout(priv->base + priv->dcfg->xSR[IMX_MU_TSR],
301 						 xsr,
302 						 xsr & IMX_MU_xSR_TEn(priv->dcfg->type, i % num_tr),
303 						 0, 5 * USEC_PER_SEC);
304 			if (ret) {
305 				dev_err(priv->dev, "Send data index: %d timeout\n", i);
306 				return ret;
307 			}
308 			imx_mu_write(priv, *arg++, priv->dcfg->xTR + (i % num_tr) * 4);
309 		}
310 
311 		imx_mu_xcr_rmw(priv, IMX_MU_TCR, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx), 0);
312 		break;
313 	default:
314 		dev_warn_ratelimited(priv->dev, "Send data on wrong channel type: %d\n", cp->type);
315 		return -EINVAL;
316 	}
317 
318 	return 0;
319 }
320 
321 static int imx_mu_specific_rx(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp)
322 {
323 	u32 *data;
324 	int i, ret;
325 	u32 xsr;
326 	u32 size, max_size;
327 
328 	data = (u32 *)priv->msg;
329 
330 	imx_mu_xcr_rmw(priv, IMX_MU_RCR, 0, IMX_MU_xCR_RIEn(priv->dcfg->type, 0));
331 	*data++ = imx_mu_read(priv, priv->dcfg->xRR);
332 
333 	if (priv->dcfg->type & IMX_MU_V2_S4) {
334 		size = ((struct imx_s4_rpc_msg_max *)priv->msg)->hdr.size;
335 		max_size = sizeof(struct imx_s4_rpc_msg_max);
336 	} else {
337 		size = ((struct imx_sc_rpc_msg_max *)priv->msg)->hdr.size;
338 		max_size = sizeof(struct imx_sc_rpc_msg_max);
339 	}
340 
341 	if (size > max_size / 4) {
342 		dev_err(priv->dev, "Maximal message size (%u bytes) exceeded on RX; got: %i bytes\n", max_size, size << 2);
343 		return -EINVAL;
344 	}
345 
346 	for (i = 1; i < size; i++) {
347 		ret = readl_poll_timeout(priv->base + priv->dcfg->xSR[IMX_MU_RSR], xsr,
348 					 xsr & IMX_MU_xSR_RFn(priv->dcfg->type, i % 4), 0,
349 					 5 * USEC_PER_SEC);
350 		if (ret) {
351 			dev_err(priv->dev, "timeout read idx %d\n", i);
352 			return ret;
353 		}
354 		*data++ = imx_mu_read(priv, priv->dcfg->xRR + (i % 4) * 4);
355 	}
356 
357 	imx_mu_xcr_rmw(priv, IMX_MU_RCR, IMX_MU_xCR_RIEn(priv->dcfg->type, 0), 0);
358 	mbox_chan_received_data(cp->chan, (void *)priv->msg);
359 
360 	return 0;
361 }
362 
363 static int imx_mu_seco_tx(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp,
364 			  void *data)
365 {
366 	struct imx_sc_rpc_msg_max *msg = data;
367 	u32 *arg = data;
368 	u32 byte_size;
369 	int err;
370 	int i;
371 
372 	dev_dbg(priv->dev, "Sending message\n");
373 
374 	switch (cp->type) {
375 	case IMX_MU_TYPE_TXDB:
376 		byte_size = msg->hdr.size * sizeof(u32);
377 		if (byte_size > sizeof(*msg)) {
378 			/*
379 			 * The real message size can be different to
380 			 * struct imx_sc_rpc_msg_max size
381 			 */
382 			dev_err(priv->dev,
383 				"Exceed max msg size (%zu) on TX, got: %i\n",
384 				sizeof(*msg), byte_size);
385 			return -EINVAL;
386 		}
387 
388 		print_hex_dump_debug("from client ", DUMP_PREFIX_OFFSET, 4, 4,
389 				     data, byte_size, false);
390 
391 		/* Send first word */
392 		dev_dbg(priv->dev, "Sending header\n");
393 		imx_mu_write(priv, *arg++, priv->dcfg->xTR);
394 
395 		/* Send signaling */
396 		dev_dbg(priv->dev, "Sending signaling\n");
397 		imx_mu_xcr_rmw(priv, IMX_MU_GCR,
398 			       IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx), 0);
399 
400 		/* Send words to fill the mailbox */
401 		for (i = 1; i < 4 && i < msg->hdr.size; i++) {
402 			dev_dbg(priv->dev, "Sending word %d\n", i);
403 			imx_mu_write(priv, *arg++,
404 				     priv->dcfg->xTR + (i % 4) * 4);
405 		}
406 
407 		/* Send rest of message waiting for remote read */
408 		for (; i < msg->hdr.size; i++) {
409 			dev_dbg(priv->dev, "Sending word %d\n", i);
410 			err = imx_mu_tx_waiting_write(priv, *arg++, i);
411 			if (err) {
412 				dev_err(priv->dev, "Timeout tx %d\n", i);
413 				return err;
414 			}
415 		}
416 
417 		/* Simulate hack for mbox framework */
418 		tasklet_schedule(&cp->txdb_tasklet);
419 
420 		break;
421 	default:
422 		dev_warn_ratelimited(priv->dev,
423 				     "Send data on wrong channel type: %d\n",
424 				     cp->type);
425 		return -EINVAL;
426 	}
427 
428 	return 0;
429 }
430 
431 static int imx_mu_seco_rxdb(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp)
432 {
433 	struct imx_sc_rpc_msg_max msg;
434 	u32 *data = (u32 *)&msg;
435 	u32 byte_size;
436 	int err = 0;
437 	int i;
438 
439 	dev_dbg(priv->dev, "Receiving message\n");
440 
441 	/* Read header */
442 	dev_dbg(priv->dev, "Receiving header\n");
443 	*data++ = imx_mu_read(priv, priv->dcfg->xRR);
444 	byte_size = msg.hdr.size * sizeof(u32);
445 	if (byte_size > sizeof(msg)) {
446 		dev_err(priv->dev, "Exceed max msg size (%zu) on RX, got: %i\n",
447 			sizeof(msg), byte_size);
448 		err = -EINVAL;
449 		goto error;
450 	}
451 
452 	/* Read message waiting they are written */
453 	for (i = 1; i < msg.hdr.size; i++) {
454 		dev_dbg(priv->dev, "Receiving word %d\n", i);
455 		err = imx_mu_rx_waiting_read(priv, data++, i);
456 		if (err) {
457 			dev_err(priv->dev, "Timeout rx %d\n", i);
458 			goto error;
459 		}
460 	}
461 
462 	/* Clear GIP */
463 	imx_mu_write(priv, IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx),
464 		     priv->dcfg->xSR[IMX_MU_GSR]);
465 
466 	print_hex_dump_debug("to client ", DUMP_PREFIX_OFFSET, 4, 4,
467 			     &msg, byte_size, false);
468 
469 	/* send data to client */
470 	dev_dbg(priv->dev, "Sending message to client\n");
471 	mbox_chan_received_data(cp->chan, (void *)&msg);
472 
473 	goto exit;
474 
475 error:
476 	mbox_chan_received_data(cp->chan, ERR_PTR(err));
477 
478 exit:
479 	return err;
480 }
481 
482 static void imx_mu_txdb_tasklet(unsigned long data)
483 {
484 	struct imx_mu_con_priv *cp = (struct imx_mu_con_priv *)data;
485 
486 	mbox_chan_txdone(cp->chan, 0);
487 }
488 
489 static irqreturn_t imx_mu_isr(int irq, void *p)
490 {
491 	struct mbox_chan *chan = p;
492 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
493 	struct imx_mu_con_priv *cp = chan->con_priv;
494 	u32 val, ctrl;
495 
496 	switch (cp->type) {
497 	case IMX_MU_TYPE_TX:
498 		ctrl = imx_mu_read(priv, priv->dcfg->xCR[IMX_MU_TCR]);
499 		val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_TSR]);
500 		val &= IMX_MU_xSR_TEn(priv->dcfg->type, cp->idx) &
501 			(ctrl & IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx));
502 		break;
503 	case IMX_MU_TYPE_RX:
504 		ctrl = imx_mu_read(priv, priv->dcfg->xCR[IMX_MU_RCR]);
505 		val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_RSR]);
506 		val &= IMX_MU_xSR_RFn(priv->dcfg->type, cp->idx) &
507 			(ctrl & IMX_MU_xCR_RIEn(priv->dcfg->type, cp->idx));
508 		break;
509 	case IMX_MU_TYPE_RXDB:
510 		ctrl = imx_mu_read(priv, priv->dcfg->xCR[IMX_MU_GIER]);
511 		val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_GSR]);
512 		val &= IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx) &
513 			(ctrl & IMX_MU_xCR_GIEn(priv->dcfg->type, cp->idx));
514 		break;
515 	case IMX_MU_TYPE_RST:
516 		return IRQ_NONE;
517 	default:
518 		dev_warn_ratelimited(priv->dev, "Unhandled channel type %d\n",
519 				     cp->type);
520 		return IRQ_NONE;
521 	}
522 
523 	if (!val)
524 		return IRQ_NONE;
525 
526 	if ((val == IMX_MU_xSR_TEn(priv->dcfg->type, cp->idx)) &&
527 	    (cp->type == IMX_MU_TYPE_TX)) {
528 		imx_mu_xcr_rmw(priv, IMX_MU_TCR, 0, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx));
529 		mbox_chan_txdone(chan, 0);
530 	} else if ((val == IMX_MU_xSR_RFn(priv->dcfg->type, cp->idx)) &&
531 		   (cp->type == IMX_MU_TYPE_RX)) {
532 		priv->dcfg->rx(priv, cp);
533 	} else if ((val == IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx)) &&
534 		   (cp->type == IMX_MU_TYPE_RXDB)) {
535 		priv->dcfg->rxdb(priv, cp);
536 	} else {
537 		dev_warn_ratelimited(priv->dev, "Not handled interrupt\n");
538 		return IRQ_NONE;
539 	}
540 
541 	if (priv->suspend)
542 		pm_system_wakeup();
543 
544 	return IRQ_HANDLED;
545 }
546 
547 static int imx_mu_send_data(struct mbox_chan *chan, void *data)
548 {
549 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
550 	struct imx_mu_con_priv *cp = chan->con_priv;
551 
552 	return priv->dcfg->tx(priv, cp, data);
553 }
554 
555 static int imx_mu_startup(struct mbox_chan *chan)
556 {
557 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
558 	struct imx_mu_con_priv *cp = chan->con_priv;
559 	unsigned long irq_flag = 0;
560 	int ret;
561 
562 	pm_runtime_get_sync(priv->dev);
563 	if (cp->type == IMX_MU_TYPE_TXDB_V2)
564 		return 0;
565 
566 	if (cp->type == IMX_MU_TYPE_TXDB) {
567 		/* Tx doorbell don't have ACK support */
568 		tasklet_init(&cp->txdb_tasklet, imx_mu_txdb_tasklet,
569 			     (unsigned long)cp);
570 		return 0;
571 	}
572 
573 	/* IPC MU should be with IRQF_NO_SUSPEND set */
574 	if (!priv->dev->pm_domain)
575 		irq_flag |= IRQF_NO_SUSPEND;
576 
577 	if (!(priv->dcfg->type & IMX_MU_V2_IRQ))
578 		irq_flag |= IRQF_SHARED;
579 
580 	ret = request_irq(priv->irq[cp->type], imx_mu_isr, irq_flag, cp->irq_desc, chan);
581 	if (ret) {
582 		dev_err(priv->dev, "Unable to acquire IRQ %d\n", priv->irq[cp->type]);
583 		return ret;
584 	}
585 
586 	switch (cp->type) {
587 	case IMX_MU_TYPE_RX:
588 		imx_mu_xcr_rmw(priv, IMX_MU_RCR, IMX_MU_xCR_RIEn(priv->dcfg->type, cp->idx), 0);
589 		break;
590 	case IMX_MU_TYPE_RXDB:
591 		imx_mu_xcr_rmw(priv, IMX_MU_GIER, IMX_MU_xCR_GIEn(priv->dcfg->type, cp->idx), 0);
592 		break;
593 	default:
594 		break;
595 	}
596 
597 	return 0;
598 }
599 
600 static void imx_mu_shutdown(struct mbox_chan *chan)
601 {
602 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
603 	struct imx_mu_con_priv *cp = chan->con_priv;
604 	int ret;
605 	u32 sr;
606 
607 	if (cp->type == IMX_MU_TYPE_TXDB_V2) {
608 		pm_runtime_put_sync(priv->dev);
609 		return;
610 	}
611 
612 	if (cp->type == IMX_MU_TYPE_TXDB) {
613 		tasklet_kill(&cp->txdb_tasklet);
614 		pm_runtime_put_sync(priv->dev);
615 		return;
616 	}
617 
618 	switch (cp->type) {
619 	case IMX_MU_TYPE_TX:
620 		imx_mu_xcr_rmw(priv, IMX_MU_TCR, 0, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx));
621 		break;
622 	case IMX_MU_TYPE_RX:
623 		imx_mu_xcr_rmw(priv, IMX_MU_RCR, 0, IMX_MU_xCR_RIEn(priv->dcfg->type, cp->idx));
624 		break;
625 	case IMX_MU_TYPE_RXDB:
626 		imx_mu_xcr_rmw(priv, IMX_MU_GIER, 0, IMX_MU_xCR_GIEn(priv->dcfg->type, cp->idx));
627 		break;
628 	case IMX_MU_TYPE_RST:
629 		imx_mu_xcr_rmw(priv, IMX_MU_CR, IMX_MU_xCR_RST(priv->dcfg->type), 0);
630 		ret = readl_poll_timeout(priv->base + priv->dcfg->xSR[IMX_MU_SR], sr,
631 					 !(sr & IMX_MU_xSR_RST(priv->dcfg->type)), 1, 5);
632 		if (ret)
633 			dev_warn(priv->dev, "RST channel timeout\n");
634 		break;
635 	default:
636 		break;
637 	}
638 
639 	free_irq(priv->irq[cp->type], chan);
640 	pm_runtime_put_sync(priv->dev);
641 }
642 
643 static const struct mbox_chan_ops imx_mu_ops = {
644 	.send_data = imx_mu_send_data,
645 	.startup = imx_mu_startup,
646 	.shutdown = imx_mu_shutdown,
647 };
648 
649 static struct mbox_chan *imx_mu_specific_xlate(struct mbox_controller *mbox,
650 					       const struct of_phandle_args *sp)
651 {
652 	u32 type, idx, chan;
653 
654 	if (sp->args_count != 2) {
655 		dev_err(mbox->dev, "Invalid argument count %d\n", sp->args_count);
656 		return ERR_PTR(-EINVAL);
657 	}
658 
659 	type = sp->args[0]; /* channel type */
660 	idx = sp->args[1]; /* index */
661 
662 	switch (type) {
663 	case IMX_MU_TYPE_TX:
664 	case IMX_MU_TYPE_RX:
665 		if (idx != 0)
666 			dev_err(mbox->dev, "Invalid chan idx: %d\n", idx);
667 		chan = type;
668 		break;
669 	case IMX_MU_TYPE_RXDB:
670 		chan = 2 + idx;
671 		break;
672 	default:
673 		dev_err(mbox->dev, "Invalid chan type: %d\n", type);
674 		return ERR_PTR(-EINVAL);
675 	}
676 
677 	if (chan >= mbox->num_chans) {
678 		dev_err(mbox->dev, "Not supported channel number: %d. (type: %d, idx: %d)\n", chan, type, idx);
679 		return ERR_PTR(-EINVAL);
680 	}
681 
682 	return &mbox->chans[chan];
683 }
684 
685 static struct mbox_chan * imx_mu_xlate(struct mbox_controller *mbox,
686 				       const struct of_phandle_args *sp)
687 {
688 	struct mbox_chan *p_chan;
689 	u32 type, idx, chan;
690 
691 	if (sp->args_count != 2) {
692 		dev_err(mbox->dev, "Invalid argument count %d\n", sp->args_count);
693 		return ERR_PTR(-EINVAL);
694 	}
695 
696 	type = sp->args[0]; /* channel type */
697 	idx = sp->args[1]; /* index */
698 
699 	/* RST only supports 1 channel */
700 	if ((type == IMX_MU_TYPE_RST) && idx) {
701 		dev_err(mbox->dev, "Invalid RST channel %d\n", idx);
702 		return ERR_PTR(-EINVAL);
703 	}
704 
705 	chan = type * 4 + idx;
706 	if (chan >= mbox->num_chans) {
707 		dev_err(mbox->dev, "Not supported channel number: %d. (type: %d, idx: %d)\n", chan, type, idx);
708 		return ERR_PTR(-EINVAL);
709 	}
710 
711 	p_chan = &mbox->chans[chan];
712 
713 	if (type == IMX_MU_TYPE_TXDB_V2)
714 		p_chan->txdone_method = TXDONE_BY_ACK;
715 
716 	return p_chan;
717 }
718 
719 static struct mbox_chan *imx_mu_seco_xlate(struct mbox_controller *mbox,
720 					   const struct of_phandle_args *sp)
721 {
722 	u32 type;
723 
724 	if (sp->args_count < 1) {
725 		dev_err(mbox->dev, "Invalid argument count %d\n", sp->args_count);
726 		return ERR_PTR(-EINVAL);
727 	}
728 
729 	type = sp->args[0]; /* channel type */
730 
731 	/* Only supports TXDB and RXDB */
732 	if (type == IMX_MU_TYPE_TX || type == IMX_MU_TYPE_RX) {
733 		dev_err(mbox->dev, "Invalid type: %d\n", type);
734 		return ERR_PTR(-EINVAL);
735 	}
736 
737 	return imx_mu_xlate(mbox, sp);
738 }
739 
740 static void imx_mu_init_generic(struct imx_mu_priv *priv)
741 {
742 	unsigned int i;
743 	unsigned int val;
744 
745 	for (i = 0; i < IMX_MU_CHANS; i++) {
746 		struct imx_mu_con_priv *cp = &priv->con_priv[i];
747 
748 		cp->idx = i % 4;
749 		cp->type = i >> 2;
750 		cp->chan = &priv->mbox_chans[i];
751 		priv->mbox_chans[i].con_priv = cp;
752 		snprintf(cp->irq_desc, sizeof(cp->irq_desc),
753 			 "imx_mu_chan[%i-%i]", cp->type, cp->idx);
754 	}
755 
756 	priv->mbox.num_chans = IMX_MU_CHANS;
757 	priv->mbox.of_xlate = imx_mu_xlate;
758 
759 	if (priv->side_b)
760 		return;
761 
762 	/* Set default MU configuration */
763 	for (i = 0; i < IMX_MU_xCR_MAX; i++)
764 		imx_mu_write(priv, 0, priv->dcfg->xCR[i]);
765 
766 	/* Clear any pending GIP */
767 	val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_GSR]);
768 	imx_mu_write(priv, val, priv->dcfg->xSR[IMX_MU_GSR]);
769 
770 	/* Clear any pending RSR */
771 	for (i = 0; i < IMX_MU_NUM_RR; i++)
772 		imx_mu_read(priv, priv->dcfg->xRR + (i % 4) * 4);
773 }
774 
775 static void imx_mu_init_specific(struct imx_mu_priv *priv)
776 {
777 	unsigned int i;
778 	int num_chans = priv->dcfg->type & IMX_MU_V2_S4 ? IMX_MU_S4_CHANS : IMX_MU_SCU_CHANS;
779 
780 	for (i = 0; i < num_chans; i++) {
781 		struct imx_mu_con_priv *cp = &priv->con_priv[i];
782 
783 		cp->idx = i < 2 ? 0 : i - 2;
784 		cp->type = i < 2 ? i : IMX_MU_TYPE_RXDB;
785 		cp->chan = &priv->mbox_chans[i];
786 		priv->mbox_chans[i].con_priv = cp;
787 		snprintf(cp->irq_desc, sizeof(cp->irq_desc),
788 			 "imx_mu_chan[%i-%i]", cp->type, cp->idx);
789 	}
790 
791 	priv->mbox.num_chans = num_chans;
792 	priv->mbox.of_xlate = imx_mu_specific_xlate;
793 
794 	/* Set default MU configuration */
795 	for (i = 0; i < IMX_MU_xCR_MAX; i++)
796 		imx_mu_write(priv, 0, priv->dcfg->xCR[i]);
797 }
798 
799 static void imx_mu_init_seco(struct imx_mu_priv *priv)
800 {
801 	imx_mu_init_generic(priv);
802 	priv->mbox.of_xlate = imx_mu_seco_xlate;
803 }
804 
805 static int imx_mu_probe(struct platform_device *pdev)
806 {
807 	struct device *dev = &pdev->dev;
808 	struct device_node *np = dev->of_node;
809 	struct imx_mu_priv *priv;
810 	const struct imx_mu_dcfg *dcfg;
811 	int i, ret;
812 	u32 size;
813 
814 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
815 	if (!priv)
816 		return -ENOMEM;
817 
818 	priv->dev = dev;
819 
820 	priv->base = devm_platform_ioremap_resource(pdev, 0);
821 	if (IS_ERR(priv->base))
822 		return PTR_ERR(priv->base);
823 
824 	dcfg = of_device_get_match_data(dev);
825 	if (!dcfg)
826 		return -EINVAL;
827 	priv->dcfg = dcfg;
828 	if (priv->dcfg->type & IMX_MU_V2_IRQ) {
829 		priv->irq[IMX_MU_TYPE_TX] = platform_get_irq_byname(pdev, "tx");
830 		if (priv->irq[IMX_MU_TYPE_TX] < 0)
831 			return priv->irq[IMX_MU_TYPE_TX];
832 		priv->irq[IMX_MU_TYPE_RX] = platform_get_irq_byname(pdev, "rx");
833 		if (priv->irq[IMX_MU_TYPE_RX] < 0)
834 			return priv->irq[IMX_MU_TYPE_RX];
835 	} else {
836 		ret = platform_get_irq(pdev, 0);
837 		if (ret < 0)
838 			return ret;
839 
840 		for (i = 0; i < IMX_MU_CHANS; i++)
841 			priv->irq[i] = ret;
842 	}
843 
844 	if (priv->dcfg->type & IMX_MU_V2_S4)
845 		size = sizeof(struct imx_s4_rpc_msg_max);
846 	else
847 		size = sizeof(struct imx_sc_rpc_msg_max);
848 
849 	priv->msg = devm_kzalloc(dev, size, GFP_KERNEL);
850 	if (!priv->msg)
851 		return -ENOMEM;
852 
853 	priv->clk = devm_clk_get(dev, NULL);
854 	if (IS_ERR(priv->clk)) {
855 		if (PTR_ERR(priv->clk) != -ENOENT)
856 			return PTR_ERR(priv->clk);
857 
858 		priv->clk = NULL;
859 	}
860 
861 	ret = clk_prepare_enable(priv->clk);
862 	if (ret) {
863 		dev_err(dev, "Failed to enable clock\n");
864 		return ret;
865 	}
866 
867 	priv->side_b = of_property_read_bool(np, "fsl,mu-side-b");
868 
869 	priv->dcfg->init(priv);
870 
871 	spin_lock_init(&priv->xcr_lock);
872 
873 	priv->mbox.dev = dev;
874 	priv->mbox.ops = &imx_mu_ops;
875 	priv->mbox.chans = priv->mbox_chans;
876 	priv->mbox.txdone_irq = true;
877 
878 	platform_set_drvdata(pdev, priv);
879 
880 	ret = devm_mbox_controller_register(dev, &priv->mbox);
881 	if (ret) {
882 		clk_disable_unprepare(priv->clk);
883 		return ret;
884 	}
885 
886 	pm_runtime_enable(dev);
887 
888 	ret = pm_runtime_resume_and_get(dev);
889 	if (ret < 0)
890 		goto disable_runtime_pm;
891 
892 	ret = pm_runtime_put_sync(dev);
893 	if (ret < 0)
894 		goto disable_runtime_pm;
895 
896 	clk_disable_unprepare(priv->clk);
897 
898 	return 0;
899 
900 disable_runtime_pm:
901 	pm_runtime_disable(dev);
902 	clk_disable_unprepare(priv->clk);
903 	return ret;
904 }
905 
906 static void imx_mu_remove(struct platform_device *pdev)
907 {
908 	struct imx_mu_priv *priv = platform_get_drvdata(pdev);
909 
910 	pm_runtime_disable(priv->dev);
911 }
912 
913 static const struct imx_mu_dcfg imx_mu_cfg_imx6sx = {
914 	.tx	= imx_mu_generic_tx,
915 	.rx	= imx_mu_generic_rx,
916 	.rxdb	= imx_mu_generic_rxdb,
917 	.init	= imx_mu_init_generic,
918 	.xTR	= 0x0,
919 	.xRR	= 0x10,
920 	.xSR	= {0x20, 0x20, 0x20, 0x20},
921 	.xCR	= {0x24, 0x24, 0x24, 0x24, 0x24},
922 };
923 
924 static const struct imx_mu_dcfg imx_mu_cfg_imx7ulp = {
925 	.tx	= imx_mu_generic_tx,
926 	.rx	= imx_mu_generic_rx,
927 	.rxdb	= imx_mu_generic_rxdb,
928 	.init	= imx_mu_init_generic,
929 	.xTR	= 0x20,
930 	.xRR	= 0x40,
931 	.xSR	= {0x60, 0x60, 0x60, 0x60},
932 	.xCR	= {0x64, 0x64, 0x64, 0x64, 0x64},
933 };
934 
935 static const struct imx_mu_dcfg imx_mu_cfg_imx8ulp = {
936 	.tx	= imx_mu_generic_tx,
937 	.rx	= imx_mu_generic_rx,
938 	.rxdb	= imx_mu_generic_rxdb,
939 	.init	= imx_mu_init_generic,
940 	.type	= IMX_MU_V2,
941 	.xTR	= 0x200,
942 	.xRR	= 0x280,
943 	.xSR	= {0xC, 0x118, 0x124, 0x12C},
944 	.xCR	= {0x8, 0x110, 0x114, 0x120, 0x128},
945 };
946 
947 static const struct imx_mu_dcfg imx_mu_cfg_imx8ulp_s4 = {
948 	.tx	= imx_mu_specific_tx,
949 	.rx	= imx_mu_specific_rx,
950 	.init	= imx_mu_init_specific,
951 	.type	= IMX_MU_V2 | IMX_MU_V2_S4,
952 	.xTR	= 0x200,
953 	.xRR	= 0x280,
954 	.xSR	= {0xC, 0x118, 0x124, 0x12C},
955 	.xCR	= {0x8, 0x110, 0x114, 0x120, 0x128},
956 };
957 
958 static const struct imx_mu_dcfg imx_mu_cfg_imx93_s4 = {
959 	.tx	= imx_mu_specific_tx,
960 	.rx	= imx_mu_specific_rx,
961 	.init	= imx_mu_init_specific,
962 	.type	= IMX_MU_V2 | IMX_MU_V2_S4 | IMX_MU_V2_IRQ,
963 	.xTR	= 0x200,
964 	.xRR	= 0x280,
965 	.xSR	= {0xC, 0x118, 0x124, 0x12C},
966 	.xCR	= {0x8, 0x110, 0x114, 0x120, 0x128},
967 };
968 
969 static const struct imx_mu_dcfg imx_mu_cfg_imx8_scu = {
970 	.tx	= imx_mu_specific_tx,
971 	.rx	= imx_mu_specific_rx,
972 	.init	= imx_mu_init_specific,
973 	.rxdb	= imx_mu_generic_rxdb,
974 	.xTR	= 0x0,
975 	.xRR	= 0x10,
976 	.xSR	= {0x20, 0x20, 0x20, 0x20},
977 	.xCR	= {0x24, 0x24, 0x24, 0x24, 0x24},
978 };
979 
980 static const struct imx_mu_dcfg imx_mu_cfg_imx8_seco = {
981 	.tx	= imx_mu_seco_tx,
982 	.rx	= imx_mu_generic_rx,
983 	.rxdb	= imx_mu_seco_rxdb,
984 	.init	= imx_mu_init_seco,
985 	.xTR	= 0x0,
986 	.xRR	= 0x10,
987 	.xSR	= {0x20, 0x20, 0x20, 0x20},
988 	.xCR	= {0x24, 0x24, 0x24, 0x24, 0x24},
989 };
990 
991 static const struct of_device_id imx_mu_dt_ids[] = {
992 	{ .compatible = "fsl,imx7ulp-mu", .data = &imx_mu_cfg_imx7ulp },
993 	{ .compatible = "fsl,imx6sx-mu", .data = &imx_mu_cfg_imx6sx },
994 	{ .compatible = "fsl,imx8ulp-mu", .data = &imx_mu_cfg_imx8ulp },
995 	{ .compatible = "fsl,imx8ulp-mu-s4", .data = &imx_mu_cfg_imx8ulp_s4 },
996 	{ .compatible = "fsl,imx93-mu-s4", .data = &imx_mu_cfg_imx93_s4 },
997 	{ .compatible = "fsl,imx8-mu-scu", .data = &imx_mu_cfg_imx8_scu },
998 	{ .compatible = "fsl,imx8-mu-seco", .data = &imx_mu_cfg_imx8_seco },
999 	{ },
1000 };
1001 MODULE_DEVICE_TABLE(of, imx_mu_dt_ids);
1002 
1003 static int __maybe_unused imx_mu_suspend_noirq(struct device *dev)
1004 {
1005 	struct imx_mu_priv *priv = dev_get_drvdata(dev);
1006 	int i;
1007 
1008 	if (!priv->clk) {
1009 		for (i = 0; i < IMX_MU_xCR_MAX; i++)
1010 			priv->xcr[i] = imx_mu_read(priv, priv->dcfg->xCR[i]);
1011 	}
1012 
1013 	priv->suspend = true;
1014 
1015 	return 0;
1016 }
1017 
1018 static int __maybe_unused imx_mu_resume_noirq(struct device *dev)
1019 {
1020 	struct imx_mu_priv *priv = dev_get_drvdata(dev);
1021 	int i;
1022 
1023 	/*
1024 	 * ONLY restore MU when context lost, the TIE could
1025 	 * be set during noirq resume as there is MU data
1026 	 * communication going on, and restore the saved
1027 	 * value will overwrite the TIE and cause MU data
1028 	 * send failed, may lead to system freeze. This issue
1029 	 * is observed by testing freeze mode suspend.
1030 	 */
1031 	if (!priv->clk && !imx_mu_read(priv, priv->dcfg->xCR[0])) {
1032 		for (i = 0; i < IMX_MU_xCR_MAX; i++)
1033 			imx_mu_write(priv, priv->xcr[i], priv->dcfg->xCR[i]);
1034 	}
1035 
1036 	priv->suspend = false;
1037 
1038 	return 0;
1039 }
1040 
1041 static int __maybe_unused imx_mu_runtime_suspend(struct device *dev)
1042 {
1043 	struct imx_mu_priv *priv = dev_get_drvdata(dev);
1044 
1045 	clk_disable_unprepare(priv->clk);
1046 
1047 	return 0;
1048 }
1049 
1050 static int __maybe_unused imx_mu_runtime_resume(struct device *dev)
1051 {
1052 	struct imx_mu_priv *priv = dev_get_drvdata(dev);
1053 	int ret;
1054 
1055 	ret = clk_prepare_enable(priv->clk);
1056 	if (ret)
1057 		dev_err(dev, "failed to enable clock\n");
1058 
1059 	return ret;
1060 }
1061 
1062 static const struct dev_pm_ops imx_mu_pm_ops = {
1063 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx_mu_suspend_noirq,
1064 				      imx_mu_resume_noirq)
1065 	SET_RUNTIME_PM_OPS(imx_mu_runtime_suspend,
1066 			   imx_mu_runtime_resume, NULL)
1067 };
1068 
1069 static struct platform_driver imx_mu_driver = {
1070 	.probe		= imx_mu_probe,
1071 	.remove_new	= imx_mu_remove,
1072 	.driver = {
1073 		.name	= "imx_mu",
1074 		.of_match_table = imx_mu_dt_ids,
1075 		.pm = &imx_mu_pm_ops,
1076 	},
1077 };
1078 module_platform_driver(imx_mu_driver);
1079 
1080 MODULE_AUTHOR("Oleksij Rempel <o.rempel@pengutronix.de>");
1081 MODULE_DESCRIPTION("Message Unit driver for i.MX");
1082 MODULE_LICENSE("GPL v2");
1083