xref: /linux/drivers/mailbox/imx-mailbox.c (revision e7ed343658792771cf1b868df061661b7bcc5cef)
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 #include "mailbox.h"
27 
28 #define IMX_MU_CHANS		24
29 /* TX0/RX0/RXDB[0-3] */
30 #define IMX_MU_SCU_CHANS	6
31 /* TX0/RX0 */
32 #define IMX_MU_S4_CHANS		2
33 #define IMX_MU_CHAN_NAME_SIZE	32
34 
35 #define IMX_MU_V2_PAR_OFF	0x4
36 #define IMX_MU_V2_TR_MASK	GENMASK(7, 0)
37 #define IMX_MU_V2_RR_MASK	GENMASK(15, 8)
38 
39 #define IMX_MU_SECO_TX_TOUT (msecs_to_jiffies(3000))
40 #define IMX_MU_SECO_RX_TOUT (msecs_to_jiffies(3000))
41 
42 /* Please not change TX & RX */
43 enum imx_mu_chan_type {
44 	IMX_MU_TYPE_TX		= 0, /* Tx */
45 	IMX_MU_TYPE_RX		= 1, /* Rx */
46 	IMX_MU_TYPE_TXDB	= 2, /* Tx doorbell */
47 	IMX_MU_TYPE_RXDB	= 3, /* Rx doorbell */
48 	IMX_MU_TYPE_RST		= 4, /* Reset */
49 	IMX_MU_TYPE_TXDB_V2	= 5, /* Tx doorbell with S/W ACK */
50 };
51 
52 enum imx_mu_xcr {
53 	IMX_MU_CR,
54 	IMX_MU_GIER,
55 	IMX_MU_GCR,
56 	IMX_MU_TCR,
57 	IMX_MU_RCR,
58 	IMX_MU_xCR_MAX,
59 };
60 
61 enum imx_mu_xsr {
62 	IMX_MU_SR,
63 	IMX_MU_GSR,
64 	IMX_MU_TSR,
65 	IMX_MU_RSR,
66 	IMX_MU_xSR_MAX,
67 };
68 
69 struct imx_sc_rpc_msg_max {
70 	struct imx_sc_rpc_msg hdr;
71 	u32 data[30];
72 };
73 
74 struct imx_s4_rpc_msg_max {
75 	struct imx_s4_rpc_msg hdr;
76 	u32 data[254];
77 };
78 
79 struct imx_mu_con_priv {
80 	unsigned int		idx;
81 	char			irq_desc[IMX_MU_CHAN_NAME_SIZE];
82 	enum imx_mu_chan_type	type;
83 	struct mbox_chan	*chan;
84 	struct work_struct 	txdb_work;
85 };
86 
87 struct imx_mu_priv {
88 	struct device		*dev;
89 	void __iomem		*base;
90 	void			*msg;
91 	spinlock_t		xcr_lock; /* control register lock */
92 
93 	struct mbox_controller	mbox;
94 	struct mbox_chan	mbox_chans[IMX_MU_CHANS];
95 
96 	struct imx_mu_con_priv  con_priv[IMX_MU_CHANS];
97 	const struct imx_mu_dcfg	*dcfg;
98 	struct clk		*clk;
99 	int			irq[IMX_MU_CHANS];
100 	bool			suspend;
101 	bool			side_b;
102 
103 	u32			xcr[IMX_MU_xCR_MAX];
104 	u32			num_tr;
105 	u32			num_rr;
106 };
107 
108 enum imx_mu_type {
109 	IMX_MU_V1,
110 	IMX_MU_V2 = BIT(1),
111 	IMX_MU_V2_S4 = BIT(15),
112 	IMX_MU_V2_IRQ = BIT(16),
113 };
114 
115 struct imx_mu_dcfg {
116 	int (*tx)(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp, void *data);
117 	int (*rx)(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp);
118 	int (*rxdb)(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp);
119 	int (*init)(struct imx_mu_priv *priv);
120 	enum imx_mu_type type;
121 	u32	xTR;		/* Transmit Register0 */
122 	u32	xRR;		/* Receive Register0 */
123 	u32	xSR[IMX_MU_xSR_MAX];	/* Status Registers */
124 	u32	xCR[IMX_MU_xCR_MAX];	/* Control Registers */
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 
to_imx_mu_priv(struct mbox_controller * mbox)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 
imx_mu_write(struct imx_mu_priv * priv,u32 val,u32 offs)149 static void imx_mu_write(struct imx_mu_priv *priv, u32 val, u32 offs)
150 {
151 	iowrite32(val, priv->base + offs);
152 }
153 
imx_mu_read(struct imx_mu_priv * priv,u32 offs)154 static u32 imx_mu_read(struct imx_mu_priv *priv, u32 offs)
155 {
156 	return ioread32(priv->base + offs);
157 }
158 
imx_mu_tx_waiting_write(struct imx_mu_priv * priv,u32 val,u32 idx)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 
imx_mu_rx_waiting_read(struct imx_mu_priv * priv,u32 * val,u32 idx)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 
imx_mu_xcr_rmw(struct imx_mu_priv * priv,enum imx_mu_xcr type,u32 set,u32 clr)208 static u32 imx_mu_xcr_rmw(struct imx_mu_priv *priv, enum imx_mu_xcr type, u32 set, u32 clr)
209 {
210 	unsigned long flags;
211 	u32 val;
212 
213 	spin_lock_irqsave(&priv->xcr_lock, flags);
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 	spin_unlock_irqrestore(&priv->xcr_lock, flags);
219 
220 	return val;
221 }
222 
imx_mu_generic_tx(struct imx_mu_priv * priv,struct imx_mu_con_priv * cp,void * data)223 static int imx_mu_generic_tx(struct imx_mu_priv *priv,
224 			     struct imx_mu_con_priv *cp,
225 			     void *data)
226 {
227 	u32 *arg = data;
228 	u32 val;
229 	int ret;
230 
231 	switch (cp->type) {
232 	case IMX_MU_TYPE_TX:
233 		imx_mu_write(priv, *arg, priv->dcfg->xTR + cp->idx * 4);
234 		imx_mu_xcr_rmw(priv, IMX_MU_TCR, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx), 0);
235 		break;
236 	case IMX_MU_TYPE_TXDB:
237 		imx_mu_xcr_rmw(priv, IMX_MU_GCR, IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx), 0);
238 		queue_work(system_bh_wq, &cp->txdb_work);
239 		break;
240 	case IMX_MU_TYPE_TXDB_V2:
241 		imx_mu_write(priv, IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx),
242 			     priv->dcfg->xCR[IMX_MU_GCR]);
243 		ret = readl_poll_timeout(priv->base + priv->dcfg->xCR[IMX_MU_GCR], val,
244 					 !(val & IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx)),
245 					 0, 1000);
246 		if (ret)
247 			dev_warn_ratelimited(priv->dev, "channel type: %d failure\n", cp->type);
248 		break;
249 	default:
250 		dev_warn_ratelimited(priv->dev, "Send data on wrong channel type: %d\n", cp->type);
251 		return -EINVAL;
252 	}
253 
254 	return 0;
255 }
256 
imx_mu_generic_rx(struct imx_mu_priv * priv,struct imx_mu_con_priv * cp)257 static int imx_mu_generic_rx(struct imx_mu_priv *priv,
258 			     struct imx_mu_con_priv *cp)
259 {
260 	u32 dat;
261 
262 	dat = imx_mu_read(priv, priv->dcfg->xRR + (cp->idx) * 4);
263 	mbox_chan_received_data(cp->chan, (void *)&dat);
264 
265 	return 0;
266 }
267 
imx_mu_generic_rxdb(struct imx_mu_priv * priv,struct imx_mu_con_priv * cp)268 static int imx_mu_generic_rxdb(struct imx_mu_priv *priv,
269 			       struct imx_mu_con_priv *cp)
270 {
271 	imx_mu_write(priv, IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx),
272 		     priv->dcfg->xSR[IMX_MU_GSR]);
273 	mbox_chan_received_data(cp->chan, NULL);
274 
275 	return 0;
276 }
277 
imx_mu_specific_tx(struct imx_mu_priv * priv,struct imx_mu_con_priv * cp,void * data)278 static int imx_mu_specific_tx(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp, void *data)
279 {
280 	u32 *arg = data;
281 	u32 num_tr = priv->num_tr;
282 	int i, ret;
283 	u32 xsr;
284 	u32 size, max_size;
285 
286 	if (priv->dcfg->type & IMX_MU_V2_S4) {
287 		size = ((struct imx_s4_rpc_msg_max *)data)->hdr.size;
288 		max_size = sizeof(struct imx_s4_rpc_msg_max);
289 	} else {
290 		size = ((struct imx_sc_rpc_msg_max *)data)->hdr.size;
291 		max_size = sizeof(struct imx_sc_rpc_msg_max);
292 	}
293 
294 	switch (cp->type) {
295 	case IMX_MU_TYPE_TX:
296 		/*
297 		 * msg->hdr.size specifies the number of u32 words while
298 		 * sizeof yields bytes.
299 		 */
300 
301 		if (size > max_size / 4) {
302 			/*
303 			 * The real message size can be different to
304 			 * struct imx_sc_rpc_msg_max/imx_s4_rpc_msg_max size
305 			 */
306 			dev_err(priv->dev, "Maximal message size (%u bytes) exceeded on TX; got: %i bytes\n", max_size, size << 2);
307 			return -EINVAL;
308 		}
309 
310 		for (i = 0; i < num_tr && i < size; i++)
311 			imx_mu_write(priv, *arg++, priv->dcfg->xTR + (i % num_tr) * 4);
312 		for (; i < size; i++) {
313 			ret = readl_poll_timeout(priv->base + priv->dcfg->xSR[IMX_MU_TSR],
314 						 xsr,
315 						 xsr & IMX_MU_xSR_TEn(priv->dcfg->type, i % num_tr),
316 						 0, 5 * USEC_PER_SEC);
317 			if (ret) {
318 				dev_err(priv->dev, "Send data index: %d timeout\n", i);
319 				return ret;
320 			}
321 			imx_mu_write(priv, *arg++, priv->dcfg->xTR + (i % num_tr) * 4);
322 		}
323 
324 		imx_mu_xcr_rmw(priv, IMX_MU_TCR, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx), 0);
325 		break;
326 	default:
327 		dev_warn_ratelimited(priv->dev, "Send data on wrong channel type: %d\n", cp->type);
328 		return -EINVAL;
329 	}
330 
331 	return 0;
332 }
333 
imx_mu_specific_rx(struct imx_mu_priv * priv,struct imx_mu_con_priv * cp)334 static int imx_mu_specific_rx(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp)
335 {
336 	u32 *data;
337 	int i, ret;
338 	u32 xsr;
339 	u32 size, max_size;
340 	u32 num_rr = priv->num_rr;
341 
342 	data = (u32 *)priv->msg;
343 
344 	imx_mu_xcr_rmw(priv, IMX_MU_RCR, 0, IMX_MU_xCR_RIEn(priv->dcfg->type, 0));
345 	*data++ = imx_mu_read(priv, priv->dcfg->xRR);
346 
347 	if (priv->dcfg->type & IMX_MU_V2_S4) {
348 		size = ((struct imx_s4_rpc_msg_max *)priv->msg)->hdr.size;
349 		max_size = sizeof(struct imx_s4_rpc_msg_max);
350 	} else {
351 		size = ((struct imx_sc_rpc_msg_max *)priv->msg)->hdr.size;
352 		max_size = sizeof(struct imx_sc_rpc_msg_max);
353 	}
354 
355 	if (size > max_size / 4) {
356 		dev_err(priv->dev, "Maximal message size (%u bytes) exceeded on RX; got: %i bytes\n", max_size, size << 2);
357 		return -EINVAL;
358 	}
359 
360 	for (i = 1; i < size; i++) {
361 		ret = readl_poll_timeout(priv->base + priv->dcfg->xSR[IMX_MU_RSR], xsr,
362 					 xsr & IMX_MU_xSR_RFn(priv->dcfg->type, i % num_rr), 0,
363 					 5 * USEC_PER_SEC);
364 		if (ret) {
365 			dev_err(priv->dev, "timeout read idx %d\n", i);
366 			return ret;
367 		}
368 		*data++ = imx_mu_read(priv, priv->dcfg->xRR + (i % num_rr) * 4);
369 	}
370 
371 	imx_mu_xcr_rmw(priv, IMX_MU_RCR, IMX_MU_xCR_RIEn(priv->dcfg->type, 0), 0);
372 	mbox_chan_received_data(cp->chan, (void *)priv->msg);
373 
374 	return 0;
375 }
376 
imx_mu_seco_tx(struct imx_mu_priv * priv,struct imx_mu_con_priv * cp,void * data)377 static int imx_mu_seco_tx(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp,
378 			  void *data)
379 {
380 	struct imx_sc_rpc_msg_max *msg = data;
381 	u32 *arg = data;
382 	u32 byte_size;
383 	int err;
384 	int i;
385 
386 	dev_dbg(priv->dev, "Sending message\n");
387 
388 	switch (cp->type) {
389 	case IMX_MU_TYPE_TXDB:
390 		byte_size = msg->hdr.size * sizeof(u32);
391 		if (byte_size > sizeof(*msg)) {
392 			/*
393 			 * The real message size can be different to
394 			 * struct imx_sc_rpc_msg_max size
395 			 */
396 			dev_err(priv->dev,
397 				"Exceed max msg size (%zu) on TX, got: %i\n",
398 				sizeof(*msg), byte_size);
399 			return -EINVAL;
400 		}
401 
402 		print_hex_dump_debug("from client ", DUMP_PREFIX_OFFSET, 4, 4,
403 				     data, byte_size, false);
404 
405 		/* Send first word */
406 		dev_dbg(priv->dev, "Sending header\n");
407 		imx_mu_write(priv, *arg++, priv->dcfg->xTR);
408 
409 		/* Send signaling */
410 		dev_dbg(priv->dev, "Sending signaling\n");
411 		imx_mu_xcr_rmw(priv, IMX_MU_GCR,
412 			       IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx), 0);
413 
414 		/* Send words to fill the mailbox */
415 		for (i = 1; i < 4 && i < msg->hdr.size; i++) {
416 			dev_dbg(priv->dev, "Sending word %d\n", i);
417 			imx_mu_write(priv, *arg++,
418 				     priv->dcfg->xTR + (i % 4) * 4);
419 		}
420 
421 		/* Send rest of message waiting for remote read */
422 		for (; i < msg->hdr.size; i++) {
423 			dev_dbg(priv->dev, "Sending word %d\n", i);
424 			err = imx_mu_tx_waiting_write(priv, *arg++, i);
425 			if (err) {
426 				dev_err(priv->dev, "Timeout tx %d\n", i);
427 				return err;
428 			}
429 		}
430 
431 		/* Simulate hack for mbox framework */
432 		queue_work(system_bh_wq, &cp->txdb_work);
433 
434 		break;
435 	default:
436 		dev_warn_ratelimited(priv->dev,
437 				     "Send data on wrong channel type: %d\n",
438 				     cp->type);
439 		return -EINVAL;
440 	}
441 
442 	return 0;
443 }
444 
imx_mu_seco_rxdb(struct imx_mu_priv * priv,struct imx_mu_con_priv * cp)445 static int imx_mu_seco_rxdb(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp)
446 {
447 	struct imx_sc_rpc_msg_max msg;
448 	u32 *data = (u32 *)&msg;
449 	u32 byte_size;
450 	int err = 0;
451 	int i;
452 
453 	dev_dbg(priv->dev, "Receiving message\n");
454 
455 	/* Read header */
456 	dev_dbg(priv->dev, "Receiving header\n");
457 	*data++ = imx_mu_read(priv, priv->dcfg->xRR);
458 	byte_size = msg.hdr.size * sizeof(u32);
459 	if (byte_size > sizeof(msg)) {
460 		dev_err(priv->dev, "Exceed max msg size (%zu) on RX, got: %i\n",
461 			sizeof(msg), byte_size);
462 		err = -EINVAL;
463 		goto error;
464 	}
465 
466 	/* Read message waiting they are written */
467 	for (i = 1; i < msg.hdr.size; i++) {
468 		dev_dbg(priv->dev, "Receiving word %d\n", i);
469 		err = imx_mu_rx_waiting_read(priv, data++, i);
470 		if (err) {
471 			dev_err(priv->dev, "Timeout rx %d\n", i);
472 			goto error;
473 		}
474 	}
475 
476 	/* Clear GIP */
477 	imx_mu_write(priv, IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx),
478 		     priv->dcfg->xSR[IMX_MU_GSR]);
479 
480 	print_hex_dump_debug("to client ", DUMP_PREFIX_OFFSET, 4, 4,
481 			     &msg, byte_size, false);
482 
483 	/* send data to client */
484 	dev_dbg(priv->dev, "Sending message to client\n");
485 	mbox_chan_received_data(cp->chan, (void *)&msg);
486 
487 	goto exit;
488 
489 error:
490 	mbox_chan_received_data(cp->chan, ERR_PTR(err));
491 
492 exit:
493 	return err;
494 }
495 
imx_mu_txdb_work(struct work_struct * t)496 static void imx_mu_txdb_work(struct work_struct *t)
497 {
498 	struct imx_mu_con_priv *cp = from_work(cp, t, txdb_work);
499 
500 	mbox_chan_txdone(cp->chan, 0);
501 }
502 
imx_mu_isr(int irq,void * p)503 static irqreturn_t imx_mu_isr(int irq, void *p)
504 {
505 	struct mbox_chan *chan = p;
506 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
507 	struct imx_mu_con_priv *cp = chan->con_priv;
508 	u32 val, ctrl;
509 
510 	switch (cp->type) {
511 	case IMX_MU_TYPE_TX:
512 		ctrl = imx_mu_read(priv, priv->dcfg->xCR[IMX_MU_TCR]);
513 		val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_TSR]);
514 		val &= IMX_MU_xSR_TEn(priv->dcfg->type, cp->idx) &
515 			(ctrl & IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx));
516 		break;
517 	case IMX_MU_TYPE_RX:
518 		ctrl = imx_mu_read(priv, priv->dcfg->xCR[IMX_MU_RCR]);
519 		val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_RSR]);
520 		val &= IMX_MU_xSR_RFn(priv->dcfg->type, cp->idx) &
521 			(ctrl & IMX_MU_xCR_RIEn(priv->dcfg->type, cp->idx));
522 		break;
523 	case IMX_MU_TYPE_RXDB:
524 		ctrl = imx_mu_read(priv, priv->dcfg->xCR[IMX_MU_GIER]);
525 		val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_GSR]);
526 		val &= IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx) &
527 			(ctrl & IMX_MU_xCR_GIEn(priv->dcfg->type, cp->idx));
528 		break;
529 	case IMX_MU_TYPE_RST:
530 		return IRQ_NONE;
531 	default:
532 		dev_warn_ratelimited(priv->dev, "Unhandled channel type %d\n",
533 				     cp->type);
534 		return IRQ_NONE;
535 	}
536 
537 	if (!val)
538 		return IRQ_NONE;
539 
540 	if ((val == IMX_MU_xSR_TEn(priv->dcfg->type, cp->idx)) &&
541 	    (cp->type == IMX_MU_TYPE_TX)) {
542 		imx_mu_xcr_rmw(priv, IMX_MU_TCR, 0, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx));
543 		mbox_chan_txdone(chan, 0);
544 	} else if ((val == IMX_MU_xSR_RFn(priv->dcfg->type, cp->idx)) &&
545 		   (cp->type == IMX_MU_TYPE_RX)) {
546 		priv->dcfg->rx(priv, cp);
547 	} else if ((val == IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx)) &&
548 		   (cp->type == IMX_MU_TYPE_RXDB)) {
549 		priv->dcfg->rxdb(priv, cp);
550 	} else {
551 		dev_warn_ratelimited(priv->dev, "Not handled interrupt\n");
552 		return IRQ_NONE;
553 	}
554 
555 	if (priv->suspend)
556 		pm_system_wakeup();
557 
558 	return IRQ_HANDLED;
559 }
560 
imx_mu_send_data(struct mbox_chan * chan,void * data)561 static int imx_mu_send_data(struct mbox_chan *chan, void *data)
562 {
563 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
564 	struct imx_mu_con_priv *cp = chan->con_priv;
565 
566 	return priv->dcfg->tx(priv, cp, data);
567 }
568 
imx_mu_startup(struct mbox_chan * chan)569 static int imx_mu_startup(struct mbox_chan *chan)
570 {
571 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
572 	struct imx_mu_con_priv *cp = chan->con_priv;
573 	unsigned long irq_flag = 0;
574 	int ret;
575 
576 	pm_runtime_get_sync(priv->dev);
577 	if (cp->type == IMX_MU_TYPE_TXDB_V2)
578 		return 0;
579 
580 	if (cp->type == IMX_MU_TYPE_TXDB) {
581 		/* Tx doorbell don't have ACK support */
582 		INIT_WORK(&cp->txdb_work, imx_mu_txdb_work);
583 		return 0;
584 	}
585 
586 	/* IPC MU should be with IRQF_NO_SUSPEND set */
587 	if (!priv->dev->pm_domain)
588 		irq_flag |= IRQF_NO_SUSPEND;
589 
590 	if (!(priv->dcfg->type & IMX_MU_V2_IRQ))
591 		irq_flag |= IRQF_SHARED;
592 
593 	ret = request_irq(priv->irq[cp->type], imx_mu_isr, irq_flag, cp->irq_desc, chan);
594 	if (ret) {
595 		dev_err(priv->dev, "Unable to acquire IRQ %d\n", priv->irq[cp->type]);
596 		return ret;
597 	}
598 
599 	switch (cp->type) {
600 	case IMX_MU_TYPE_RX:
601 		imx_mu_xcr_rmw(priv, IMX_MU_RCR, IMX_MU_xCR_RIEn(priv->dcfg->type, cp->idx), 0);
602 		break;
603 	case IMX_MU_TYPE_RXDB:
604 		imx_mu_xcr_rmw(priv, IMX_MU_GIER, IMX_MU_xCR_GIEn(priv->dcfg->type, cp->idx), 0);
605 		break;
606 	default:
607 		break;
608 	}
609 
610 	return 0;
611 }
612 
imx_mu_shutdown(struct mbox_chan * chan)613 static void imx_mu_shutdown(struct mbox_chan *chan)
614 {
615 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
616 	struct imx_mu_con_priv *cp = chan->con_priv;
617 	int ret;
618 	u32 sr;
619 
620 	if (cp->type == IMX_MU_TYPE_TXDB_V2) {
621 		pm_runtime_put_sync(priv->dev);
622 		return;
623 	}
624 
625 	if (cp->type == IMX_MU_TYPE_TXDB) {
626 		cancel_work_sync(&cp->txdb_work);
627 		pm_runtime_put_sync(priv->dev);
628 		return;
629 	}
630 
631 	switch (cp->type) {
632 	case IMX_MU_TYPE_TX:
633 		imx_mu_xcr_rmw(priv, IMX_MU_TCR, 0, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx));
634 		break;
635 	case IMX_MU_TYPE_RX:
636 		imx_mu_xcr_rmw(priv, IMX_MU_RCR, 0, IMX_MU_xCR_RIEn(priv->dcfg->type, cp->idx));
637 		break;
638 	case IMX_MU_TYPE_RXDB:
639 		imx_mu_xcr_rmw(priv, IMX_MU_GIER, 0, IMX_MU_xCR_GIEn(priv->dcfg->type, cp->idx));
640 		break;
641 	case IMX_MU_TYPE_RST:
642 		imx_mu_xcr_rmw(priv, IMX_MU_CR, IMX_MU_xCR_RST(priv->dcfg->type), 0);
643 		ret = readl_poll_timeout(priv->base + priv->dcfg->xSR[IMX_MU_SR], sr,
644 					 !(sr & IMX_MU_xSR_RST(priv->dcfg->type)), 1, 5);
645 		if (ret)
646 			dev_warn(priv->dev, "RST channel timeout\n");
647 		break;
648 	default:
649 		break;
650 	}
651 
652 	free_irq(priv->irq[cp->type], chan);
653 	pm_runtime_put_sync(priv->dev);
654 }
655 
656 static const struct mbox_chan_ops imx_mu_ops = {
657 	.send_data = imx_mu_send_data,
658 	.startup = imx_mu_startup,
659 	.shutdown = imx_mu_shutdown,
660 };
661 
imx_mu_specific_xlate(struct mbox_controller * mbox,const struct of_phandle_args * sp)662 static struct mbox_chan *imx_mu_specific_xlate(struct mbox_controller *mbox,
663 					       const struct of_phandle_args *sp)
664 {
665 	u32 type, idx, chan;
666 
667 	if (sp->args_count != 2) {
668 		dev_err(mbox->dev, "Invalid argument count %d\n", sp->args_count);
669 		return ERR_PTR(-EINVAL);
670 	}
671 
672 	type = sp->args[0]; /* channel type */
673 	idx = sp->args[1]; /* index */
674 
675 	switch (type) {
676 	case IMX_MU_TYPE_TX:
677 	case IMX_MU_TYPE_RX:
678 		if (idx != 0)
679 			dev_err(mbox->dev, "Invalid chan idx: %d\n", idx);
680 		chan = type;
681 		break;
682 	case IMX_MU_TYPE_RXDB:
683 		chan = 2 + idx;
684 		break;
685 	default:
686 		dev_err(mbox->dev, "Invalid chan type: %d\n", type);
687 		return ERR_PTR(-EINVAL);
688 	}
689 
690 	if (chan >= mbox->num_chans) {
691 		dev_err(mbox->dev, "Not supported channel number: %d. (type: %d, idx: %d)\n", chan, type, idx);
692 		return ERR_PTR(-EINVAL);
693 	}
694 
695 	return &mbox->chans[chan];
696 }
697 
imx_mu_xlate(struct mbox_controller * mbox,const struct of_phandle_args * sp)698 static struct mbox_chan * imx_mu_xlate(struct mbox_controller *mbox,
699 				       const struct of_phandle_args *sp)
700 {
701 	struct mbox_chan *p_chan;
702 	u32 type, idx, chan;
703 
704 	if (sp->args_count != 2) {
705 		dev_err(mbox->dev, "Invalid argument count %d\n", sp->args_count);
706 		return ERR_PTR(-EINVAL);
707 	}
708 
709 	type = sp->args[0]; /* channel type */
710 	idx = sp->args[1]; /* index */
711 
712 	/* RST only supports 1 channel */
713 	if ((type == IMX_MU_TYPE_RST) && idx) {
714 		dev_err(mbox->dev, "Invalid RST channel %d\n", idx);
715 		return ERR_PTR(-EINVAL);
716 	}
717 
718 	chan = type * 4 + idx;
719 	if (chan >= mbox->num_chans) {
720 		dev_err(mbox->dev, "Not supported channel number: %d. (type: %d, idx: %d)\n", chan, type, idx);
721 		return ERR_PTR(-EINVAL);
722 	}
723 
724 	p_chan = &mbox->chans[chan];
725 
726 	if (type == IMX_MU_TYPE_TXDB_V2)
727 		p_chan->txdone_method = TXDONE_BY_ACK;
728 
729 	return p_chan;
730 }
731 
imx_mu_seco_xlate(struct mbox_controller * mbox,const struct of_phandle_args * sp)732 static struct mbox_chan *imx_mu_seco_xlate(struct mbox_controller *mbox,
733 					   const struct of_phandle_args *sp)
734 {
735 	u32 type;
736 
737 	if (sp->args_count < 1) {
738 		dev_err(mbox->dev, "Invalid argument count %d\n", sp->args_count);
739 		return ERR_PTR(-EINVAL);
740 	}
741 
742 	type = sp->args[0]; /* channel type */
743 
744 	/* Only supports TXDB and RXDB */
745 	if (type == IMX_MU_TYPE_TX || type == IMX_MU_TYPE_RX) {
746 		dev_err(mbox->dev, "Invalid type: %d\n", type);
747 		return ERR_PTR(-EINVAL);
748 	}
749 
750 	return imx_mu_xlate(mbox, sp);
751 }
752 
imx_mu_get_tr_rr(struct imx_mu_priv * priv)753 static void imx_mu_get_tr_rr(struct imx_mu_priv *priv)
754 {
755 	u32 val;
756 
757 	if (priv->dcfg->type & IMX_MU_V2) {
758 		val = imx_mu_read(priv, IMX_MU_V2_PAR_OFF);
759 		priv->num_tr = FIELD_GET(IMX_MU_V2_TR_MASK, val);
760 		priv->num_rr = FIELD_GET(IMX_MU_V2_RR_MASK, val);
761 	} else {
762 		priv->num_tr = 4;
763 		priv->num_rr = 4;
764 	}
765 }
766 
imx_mu_init_generic(struct imx_mu_priv * priv)767 static int imx_mu_init_generic(struct imx_mu_priv *priv)
768 {
769 	unsigned int i;
770 	unsigned int val;
771 
772 	if (priv->num_rr > 4 || priv->num_tr > 4) {
773 		WARN_ONCE(true, "%s not support TR/RR larger than 4\n", __func__);
774 		return -EOPNOTSUPP;
775 	}
776 
777 	for (i = 0; i < IMX_MU_CHANS; i++) {
778 		struct imx_mu_con_priv *cp = &priv->con_priv[i];
779 
780 		cp->idx = i % 4;
781 		cp->type = i >> 2;
782 		cp->chan = &priv->mbox_chans[i];
783 		priv->mbox_chans[i].con_priv = cp;
784 		snprintf(cp->irq_desc, sizeof(cp->irq_desc),
785 			 "%s[%i-%i]", dev_name(priv->dev), cp->type, cp->idx);
786 	}
787 
788 	priv->mbox.num_chans = IMX_MU_CHANS;
789 	priv->mbox.of_xlate = imx_mu_xlate;
790 
791 	if (priv->side_b)
792 		return 0;
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 	/* Clear any pending GIP */
799 	val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_GSR]);
800 	imx_mu_write(priv, val, priv->dcfg->xSR[IMX_MU_GSR]);
801 
802 	/* Clear any pending RSR */
803 	for (i = 0; i < priv->num_rr; i++)
804 		imx_mu_read(priv, priv->dcfg->xRR + i * 4);
805 
806 	return 0;
807 }
808 
imx_mu_init_specific(struct imx_mu_priv * priv)809 static int imx_mu_init_specific(struct imx_mu_priv *priv)
810 {
811 	unsigned int i;
812 	int num_chans = priv->dcfg->type & IMX_MU_V2_S4 ? IMX_MU_S4_CHANS : IMX_MU_SCU_CHANS;
813 
814 	for (i = 0; i < num_chans; i++) {
815 		struct imx_mu_con_priv *cp = &priv->con_priv[i];
816 
817 		cp->idx = i < 2 ? 0 : i - 2;
818 		cp->type = i < 2 ? i : IMX_MU_TYPE_RXDB;
819 		cp->chan = &priv->mbox_chans[i];
820 		priv->mbox_chans[i].con_priv = cp;
821 		snprintf(cp->irq_desc, sizeof(cp->irq_desc),
822 			 "%s[%i-%i]", dev_name(priv->dev), cp->type, cp->idx);
823 	}
824 
825 	priv->mbox.num_chans = num_chans;
826 	priv->mbox.of_xlate = imx_mu_specific_xlate;
827 
828 	/* Set default MU configuration */
829 	for (i = 0; i < IMX_MU_xCR_MAX; i++)
830 		imx_mu_write(priv, 0, priv->dcfg->xCR[i]);
831 
832 	return 0;
833 }
834 
imx_mu_init_seco(struct imx_mu_priv * priv)835 static int imx_mu_init_seco(struct imx_mu_priv *priv)
836 {
837 	int ret;
838 
839 	ret = imx_mu_init_generic(priv);
840 	if (ret)
841 		return ret;
842 	priv->mbox.of_xlate = imx_mu_seco_xlate;
843 
844 	return 0;
845 }
846 
imx_mu_probe(struct platform_device * pdev)847 static int imx_mu_probe(struct platform_device *pdev)
848 {
849 	struct device *dev = &pdev->dev;
850 	struct device_node *np = dev->of_node;
851 	struct imx_mu_priv *priv;
852 	const struct imx_mu_dcfg *dcfg;
853 	int i, ret;
854 	u32 size;
855 
856 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
857 	if (!priv)
858 		return -ENOMEM;
859 
860 	priv->dev = dev;
861 
862 	priv->base = devm_platform_ioremap_resource(pdev, 0);
863 	if (IS_ERR(priv->base))
864 		return PTR_ERR(priv->base);
865 
866 	dcfg = of_device_get_match_data(dev);
867 	if (!dcfg)
868 		return -EINVAL;
869 	priv->dcfg = dcfg;
870 	if (priv->dcfg->type & IMX_MU_V2_IRQ) {
871 		priv->irq[IMX_MU_TYPE_TX] = platform_get_irq_byname(pdev, "tx");
872 		if (priv->irq[IMX_MU_TYPE_TX] < 0)
873 			return priv->irq[IMX_MU_TYPE_TX];
874 		priv->irq[IMX_MU_TYPE_RX] = platform_get_irq_byname(pdev, "rx");
875 		if (priv->irq[IMX_MU_TYPE_RX] < 0)
876 			return priv->irq[IMX_MU_TYPE_RX];
877 	} else {
878 		ret = platform_get_irq(pdev, 0);
879 		if (ret < 0)
880 			return ret;
881 
882 		for (i = 0; i < IMX_MU_CHANS; i++)
883 			priv->irq[i] = ret;
884 	}
885 
886 	if (priv->dcfg->type & IMX_MU_V2_S4)
887 		size = sizeof(struct imx_s4_rpc_msg_max);
888 	else
889 		size = sizeof(struct imx_sc_rpc_msg_max);
890 
891 	priv->msg = devm_kzalloc(dev, size, GFP_KERNEL);
892 	if (!priv->msg)
893 		return -ENOMEM;
894 
895 	priv->clk = devm_clk_get(dev, NULL);
896 	if (IS_ERR(priv->clk)) {
897 		if (PTR_ERR(priv->clk) != -ENOENT)
898 			return PTR_ERR(priv->clk);
899 
900 		priv->clk = NULL;
901 	}
902 
903 	ret = clk_prepare_enable(priv->clk);
904 	if (ret) {
905 		dev_err(dev, "Failed to enable clock\n");
906 		return ret;
907 	}
908 
909 	imx_mu_get_tr_rr(priv);
910 
911 	priv->side_b = of_property_read_bool(np, "fsl,mu-side-b");
912 
913 	ret = priv->dcfg->init(priv);
914 	if (ret) {
915 		dev_err(dev, "Failed to init MU\n");
916 		goto disable_clk;
917 	}
918 
919 	spin_lock_init(&priv->xcr_lock);
920 
921 	priv->mbox.dev = dev;
922 	priv->mbox.ops = &imx_mu_ops;
923 	priv->mbox.chans = priv->mbox_chans;
924 	priv->mbox.txdone_irq = true;
925 
926 	platform_set_drvdata(pdev, priv);
927 
928 	ret = devm_mbox_controller_register(dev, &priv->mbox);
929 	if (ret)
930 		goto disable_clk;
931 
932 	of_platform_populate(dev->of_node, NULL, NULL, dev);
933 
934 	pm_runtime_enable(dev);
935 
936 	ret = pm_runtime_resume_and_get(dev);
937 	if (ret < 0)
938 		goto disable_runtime_pm;
939 
940 	ret = pm_runtime_put_sync(dev);
941 	if (ret < 0)
942 		goto disable_runtime_pm;
943 
944 	clk_disable_unprepare(priv->clk);
945 
946 	return 0;
947 
948 disable_runtime_pm:
949 	pm_runtime_disable(dev);
950 disable_clk:
951 	clk_disable_unprepare(priv->clk);
952 	return ret;
953 }
954 
imx_mu_remove(struct platform_device * pdev)955 static void imx_mu_remove(struct platform_device *pdev)
956 {
957 	struct imx_mu_priv *priv = platform_get_drvdata(pdev);
958 
959 	pm_runtime_disable(priv->dev);
960 }
961 
962 static const struct imx_mu_dcfg imx_mu_cfg_imx6sx = {
963 	.tx	= imx_mu_generic_tx,
964 	.rx	= imx_mu_generic_rx,
965 	.rxdb	= imx_mu_generic_rxdb,
966 	.init	= imx_mu_init_generic,
967 	.xTR	= 0x0,
968 	.xRR	= 0x10,
969 	.xSR	= {0x20, 0x20, 0x20, 0x20},
970 	.xCR	= {0x24, 0x24, 0x24, 0x24, 0x24},
971 };
972 
973 static const struct imx_mu_dcfg imx_mu_cfg_imx7ulp = {
974 	.tx	= imx_mu_generic_tx,
975 	.rx	= imx_mu_generic_rx,
976 	.rxdb	= imx_mu_generic_rxdb,
977 	.init	= imx_mu_init_generic,
978 	.xTR	= 0x20,
979 	.xRR	= 0x40,
980 	.xSR	= {0x60, 0x60, 0x60, 0x60},
981 	.xCR	= {0x64, 0x64, 0x64, 0x64, 0x64},
982 };
983 
984 static const struct imx_mu_dcfg imx_mu_cfg_imx8ulp = {
985 	.tx	= imx_mu_generic_tx,
986 	.rx	= imx_mu_generic_rx,
987 	.rxdb	= imx_mu_generic_rxdb,
988 	.init	= imx_mu_init_generic,
989 	.type	= IMX_MU_V2,
990 	.xTR	= 0x200,
991 	.xRR	= 0x280,
992 	.xSR	= {0xC, 0x118, 0x124, 0x12C},
993 	.xCR	= {0x8, 0x110, 0x114, 0x120, 0x128},
994 };
995 
996 static const struct imx_mu_dcfg imx_mu_cfg_imx8ulp_s4 = {
997 	.tx	= imx_mu_specific_tx,
998 	.rx	= imx_mu_specific_rx,
999 	.init	= imx_mu_init_specific,
1000 	.type	= IMX_MU_V2 | IMX_MU_V2_S4,
1001 	.xTR	= 0x200,
1002 	.xRR	= 0x280,
1003 	.xSR	= {0xC, 0x118, 0x124, 0x12C},
1004 	.xCR	= {0x8, 0x110, 0x114, 0x120, 0x128},
1005 };
1006 
1007 static const struct imx_mu_dcfg imx_mu_cfg_imx93_s4 = {
1008 	.tx	= imx_mu_specific_tx,
1009 	.rx	= imx_mu_specific_rx,
1010 	.init	= imx_mu_init_specific,
1011 	.type	= IMX_MU_V2 | IMX_MU_V2_S4 | IMX_MU_V2_IRQ,
1012 	.xTR	= 0x200,
1013 	.xRR	= 0x280,
1014 	.xSR	= {0xC, 0x118, 0x124, 0x12C},
1015 	.xCR	= {0x8, 0x110, 0x114, 0x120, 0x128},
1016 };
1017 
1018 static const struct imx_mu_dcfg imx_mu_cfg_imx8_scu = {
1019 	.tx	= imx_mu_specific_tx,
1020 	.rx	= imx_mu_specific_rx,
1021 	.init	= imx_mu_init_specific,
1022 	.rxdb	= imx_mu_generic_rxdb,
1023 	.xTR	= 0x0,
1024 	.xRR	= 0x10,
1025 	.xSR	= {0x20, 0x20, 0x20, 0x20},
1026 	.xCR	= {0x24, 0x24, 0x24, 0x24, 0x24},
1027 };
1028 
1029 static const struct imx_mu_dcfg imx_mu_cfg_imx8_seco = {
1030 	.tx	= imx_mu_seco_tx,
1031 	.rx	= imx_mu_generic_rx,
1032 	.rxdb	= imx_mu_seco_rxdb,
1033 	.init	= imx_mu_init_seco,
1034 	.xTR	= 0x0,
1035 	.xRR	= 0x10,
1036 	.xSR	= {0x20, 0x20, 0x20, 0x20},
1037 	.xCR	= {0x24, 0x24, 0x24, 0x24, 0x24},
1038 };
1039 
1040 static const struct of_device_id imx_mu_dt_ids[] = {
1041 	{ .compatible = "fsl,imx7ulp-mu", .data = &imx_mu_cfg_imx7ulp },
1042 	{ .compatible = "fsl,imx6sx-mu", .data = &imx_mu_cfg_imx6sx },
1043 	{ .compatible = "fsl,imx8ulp-mu", .data = &imx_mu_cfg_imx8ulp },
1044 	{ .compatible = "fsl,imx8ulp-mu-s4", .data = &imx_mu_cfg_imx8ulp_s4 },
1045 	{ .compatible = "fsl,imx93-mu-s4", .data = &imx_mu_cfg_imx93_s4 },
1046 	{ .compatible = "fsl,imx95-mu", .data = &imx_mu_cfg_imx8ulp },
1047 	{ .compatible = "fsl,imx95-mu-ele", .data = &imx_mu_cfg_imx8ulp_s4 },
1048 	{ .compatible = "fsl,imx95-mu-v2x", .data = &imx_mu_cfg_imx8ulp_s4 },
1049 	{ .compatible = "fsl,imx8-mu-scu", .data = &imx_mu_cfg_imx8_scu },
1050 	{ .compatible = "fsl,imx8-mu-seco", .data = &imx_mu_cfg_imx8_seco },
1051 	{ },
1052 };
1053 MODULE_DEVICE_TABLE(of, imx_mu_dt_ids);
1054 
imx_mu_suspend_noirq(struct device * dev)1055 static int __maybe_unused imx_mu_suspend_noirq(struct device *dev)
1056 {
1057 	struct imx_mu_priv *priv = dev_get_drvdata(dev);
1058 	int i;
1059 
1060 	if (!priv->clk) {
1061 		for (i = 0; i < IMX_MU_xCR_MAX; i++)
1062 			priv->xcr[i] = imx_mu_read(priv, priv->dcfg->xCR[i]);
1063 	}
1064 
1065 	priv->suspend = true;
1066 
1067 	return 0;
1068 }
1069 
imx_mu_resume_noirq(struct device * dev)1070 static int __maybe_unused imx_mu_resume_noirq(struct device *dev)
1071 {
1072 	struct imx_mu_priv *priv = dev_get_drvdata(dev);
1073 	int i;
1074 
1075 	/*
1076 	 * ONLY restore MU when context lost, the TIE could
1077 	 * be set during noirq resume as there is MU data
1078 	 * communication going on, and restore the saved
1079 	 * value will overwrite the TIE and cause MU data
1080 	 * send failed, may lead to system freeze. This issue
1081 	 * is observed by testing freeze mode suspend.
1082 	 */
1083 	if (!priv->clk && !imx_mu_read(priv, priv->dcfg->xCR[0])) {
1084 		for (i = 0; i < IMX_MU_xCR_MAX; i++)
1085 			imx_mu_write(priv, priv->xcr[i], priv->dcfg->xCR[i]);
1086 	}
1087 
1088 	priv->suspend = false;
1089 
1090 	return 0;
1091 }
1092 
imx_mu_runtime_suspend(struct device * dev)1093 static int __maybe_unused imx_mu_runtime_suspend(struct device *dev)
1094 {
1095 	struct imx_mu_priv *priv = dev_get_drvdata(dev);
1096 
1097 	clk_disable_unprepare(priv->clk);
1098 
1099 	return 0;
1100 }
1101 
imx_mu_runtime_resume(struct device * dev)1102 static int __maybe_unused imx_mu_runtime_resume(struct device *dev)
1103 {
1104 	struct imx_mu_priv *priv = dev_get_drvdata(dev);
1105 	int ret;
1106 
1107 	ret = clk_prepare_enable(priv->clk);
1108 	if (ret)
1109 		dev_err(dev, "failed to enable clock\n");
1110 
1111 	return ret;
1112 }
1113 
1114 static const struct dev_pm_ops imx_mu_pm_ops = {
1115 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx_mu_suspend_noirq,
1116 				      imx_mu_resume_noirq)
1117 	SET_RUNTIME_PM_OPS(imx_mu_runtime_suspend,
1118 			   imx_mu_runtime_resume, NULL)
1119 };
1120 
1121 static struct platform_driver imx_mu_driver = {
1122 	.probe		= imx_mu_probe,
1123 	.remove_new	= imx_mu_remove,
1124 	.driver = {
1125 		.name	= "imx_mu",
1126 		.of_match_table = imx_mu_dt_ids,
1127 		.pm = &imx_mu_pm_ops,
1128 	},
1129 };
1130 module_platform_driver(imx_mu_driver);
1131 
1132 MODULE_AUTHOR("Oleksij Rempel <o.rempel@pengutronix.de>");
1133 MODULE_DESCRIPTION("Message Unit driver for i.MX");
1134 MODULE_LICENSE("GPL v2");
1135