xref: /linux/drivers/mailbox/imx-mailbox.c (revision 906fd46a65383cd639e5eec72a047efc33045d86)
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	20
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 
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 	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 
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 
229 	switch (cp->type) {
230 	case IMX_MU_TYPE_TX:
231 		imx_mu_write(priv, *arg, priv->dcfg->xTR + cp->idx * 4);
232 		imx_mu_xcr_rmw(priv, IMX_MU_TCR, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx), 0);
233 		break;
234 	case IMX_MU_TYPE_TXDB:
235 		imx_mu_xcr_rmw(priv, IMX_MU_GCR, IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx), 0);
236 		queue_work(system_bh_wq, &cp->txdb_work);
237 		break;
238 	case IMX_MU_TYPE_TXDB_V2:
239 		imx_mu_xcr_rmw(priv, IMX_MU_GCR, IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx), 0);
240 		break;
241 	default:
242 		dev_warn_ratelimited(priv->dev, "Send data on wrong channel type: %d\n", cp->type);
243 		return -EINVAL;
244 	}
245 
246 	return 0;
247 }
248 
249 static int imx_mu_generic_rx(struct imx_mu_priv *priv,
250 			     struct imx_mu_con_priv *cp)
251 {
252 	u32 dat;
253 
254 	dat = imx_mu_read(priv, priv->dcfg->xRR + (cp->idx) * 4);
255 	mbox_chan_received_data(cp->chan, (void *)&dat);
256 
257 	return 0;
258 }
259 
260 static int imx_mu_generic_rxdb(struct imx_mu_priv *priv,
261 			       struct imx_mu_con_priv *cp)
262 {
263 	imx_mu_write(priv, IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx),
264 		     priv->dcfg->xSR[IMX_MU_GSR]);
265 	mbox_chan_received_data(cp->chan, NULL);
266 
267 	return 0;
268 }
269 
270 static int imx_mu_specific_tx(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp, void *data)
271 {
272 	u32 *arg = data;
273 	u32 num_tr = priv->num_tr;
274 	int i, ret;
275 	u32 xsr;
276 	u32 size, max_size;
277 
278 	if (priv->dcfg->type & IMX_MU_V2_S4) {
279 		size = ((struct imx_s4_rpc_msg_max *)data)->hdr.size;
280 		max_size = sizeof(struct imx_s4_rpc_msg_max);
281 	} else {
282 		size = ((struct imx_sc_rpc_msg_max *)data)->hdr.size;
283 		max_size = sizeof(struct imx_sc_rpc_msg_max);
284 	}
285 
286 	switch (cp->type) {
287 	case IMX_MU_TYPE_TX:
288 		/*
289 		 * msg->hdr.size specifies the number of u32 words while
290 		 * sizeof yields bytes.
291 		 */
292 
293 		if (size > max_size / 4) {
294 			/*
295 			 * The real message size can be different to
296 			 * struct imx_sc_rpc_msg_max/imx_s4_rpc_msg_max size
297 			 */
298 			dev_err(priv->dev, "Maximal message size (%u bytes) exceeded on TX; got: %i bytes\n", max_size, size << 2);
299 			return -EINVAL;
300 		}
301 
302 		for (i = 0; i < num_tr && i < size; i++)
303 			imx_mu_write(priv, *arg++, priv->dcfg->xTR + (i % num_tr) * 4);
304 		for (; i < size; i++) {
305 			ret = readl_poll_timeout(priv->base + priv->dcfg->xSR[IMX_MU_TSR],
306 						 xsr,
307 						 xsr & IMX_MU_xSR_TEn(priv->dcfg->type, i % num_tr),
308 						 0, 5 * USEC_PER_SEC);
309 			if (ret) {
310 				dev_err(priv->dev, "Send data index: %d timeout\n", i);
311 				return ret;
312 			}
313 			imx_mu_write(priv, *arg++, priv->dcfg->xTR + (i % num_tr) * 4);
314 		}
315 
316 		imx_mu_xcr_rmw(priv, IMX_MU_TCR, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx), 0);
317 		break;
318 	default:
319 		dev_warn_ratelimited(priv->dev, "Send data on wrong channel type: %d\n", cp->type);
320 		return -EINVAL;
321 	}
322 
323 	return 0;
324 }
325 
326 static int imx_mu_specific_rx(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp)
327 {
328 	u32 *data;
329 	int i, ret;
330 	u32 xsr;
331 	u32 size, max_size;
332 	u32 num_rr = priv->num_rr;
333 
334 	data = (u32 *)priv->msg;
335 
336 	imx_mu_xcr_rmw(priv, IMX_MU_RCR, 0, IMX_MU_xCR_RIEn(priv->dcfg->type, 0));
337 	*data++ = imx_mu_read(priv, priv->dcfg->xRR);
338 
339 	if (priv->dcfg->type & IMX_MU_V2_S4) {
340 		size = ((struct imx_s4_rpc_msg_max *)priv->msg)->hdr.size;
341 		max_size = sizeof(struct imx_s4_rpc_msg_max);
342 	} else {
343 		size = ((struct imx_sc_rpc_msg_max *)priv->msg)->hdr.size;
344 		max_size = sizeof(struct imx_sc_rpc_msg_max);
345 	}
346 
347 	if (size > max_size / 4) {
348 		dev_err(priv->dev, "Maximal message size (%u bytes) exceeded on RX; got: %i bytes\n", max_size, size << 2);
349 		return -EINVAL;
350 	}
351 
352 	for (i = 1; i < size; i++) {
353 		ret = readl_poll_timeout(priv->base + priv->dcfg->xSR[IMX_MU_RSR], xsr,
354 					 xsr & IMX_MU_xSR_RFn(priv->dcfg->type, i % num_rr), 0,
355 					 5 * USEC_PER_SEC);
356 		if (ret) {
357 			dev_err(priv->dev, "timeout read idx %d\n", i);
358 			return ret;
359 		}
360 		*data++ = imx_mu_read(priv, priv->dcfg->xRR + (i % num_rr) * 4);
361 	}
362 
363 	imx_mu_xcr_rmw(priv, IMX_MU_RCR, IMX_MU_xCR_RIEn(priv->dcfg->type, 0), 0);
364 	mbox_chan_received_data(cp->chan, (void *)priv->msg);
365 
366 	return 0;
367 }
368 
369 static int imx_mu_seco_tx(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp,
370 			  void *data)
371 {
372 	struct imx_sc_rpc_msg_max *msg = data;
373 	u32 *arg = data;
374 	u32 byte_size;
375 	int err;
376 	int i;
377 
378 	dev_dbg(priv->dev, "Sending message\n");
379 
380 	switch (cp->type) {
381 	case IMX_MU_TYPE_TXDB:
382 		byte_size = msg->hdr.size * sizeof(u32);
383 		if (byte_size > sizeof(*msg)) {
384 			/*
385 			 * The real message size can be different to
386 			 * struct imx_sc_rpc_msg_max size
387 			 */
388 			dev_err(priv->dev,
389 				"Exceed max msg size (%zu) on TX, got: %i\n",
390 				sizeof(*msg), byte_size);
391 			return -EINVAL;
392 		}
393 
394 		print_hex_dump_debug("from client ", DUMP_PREFIX_OFFSET, 4, 4,
395 				     data, byte_size, false);
396 
397 		/* Send first word */
398 		dev_dbg(priv->dev, "Sending header\n");
399 		imx_mu_write(priv, *arg++, priv->dcfg->xTR);
400 
401 		/* Send signaling */
402 		dev_dbg(priv->dev, "Sending signaling\n");
403 		imx_mu_xcr_rmw(priv, IMX_MU_GCR,
404 			       IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx), 0);
405 
406 		/* Send words to fill the mailbox */
407 		for (i = 1; i < 4 && i < msg->hdr.size; i++) {
408 			dev_dbg(priv->dev, "Sending word %d\n", i);
409 			imx_mu_write(priv, *arg++,
410 				     priv->dcfg->xTR + (i % 4) * 4);
411 		}
412 
413 		/* Send rest of message waiting for remote read */
414 		for (; i < msg->hdr.size; i++) {
415 			dev_dbg(priv->dev, "Sending word %d\n", i);
416 			err = imx_mu_tx_waiting_write(priv, *arg++, i);
417 			if (err) {
418 				dev_err(priv->dev, "Timeout tx %d\n", i);
419 				return err;
420 			}
421 		}
422 
423 		/* Simulate hack for mbox framework */
424 		queue_work(system_bh_wq, &cp->txdb_work);
425 
426 		break;
427 	default:
428 		dev_warn_ratelimited(priv->dev,
429 				     "Send data on wrong channel type: %d\n",
430 				     cp->type);
431 		return -EINVAL;
432 	}
433 
434 	return 0;
435 }
436 
437 static int imx_mu_seco_rxdb(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp)
438 {
439 	struct imx_sc_rpc_msg_max msg;
440 	u32 *data = (u32 *)&msg;
441 	u32 byte_size;
442 	int err = 0;
443 	int i;
444 
445 	dev_dbg(priv->dev, "Receiving message\n");
446 
447 	/* Read header */
448 	dev_dbg(priv->dev, "Receiving header\n");
449 	*data++ = imx_mu_read(priv, priv->dcfg->xRR);
450 	byte_size = msg.hdr.size * sizeof(u32);
451 	if (byte_size > sizeof(msg)) {
452 		dev_err(priv->dev, "Exceed max msg size (%zu) on RX, got: %i\n",
453 			sizeof(msg), byte_size);
454 		err = -EINVAL;
455 		goto error;
456 	}
457 
458 	/* Read message waiting they are written */
459 	for (i = 1; i < msg.hdr.size; i++) {
460 		dev_dbg(priv->dev, "Receiving word %d\n", i);
461 		err = imx_mu_rx_waiting_read(priv, data++, i);
462 		if (err) {
463 			dev_err(priv->dev, "Timeout rx %d\n", i);
464 			goto error;
465 		}
466 	}
467 
468 	/* Clear GIP */
469 	imx_mu_write(priv, IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx),
470 		     priv->dcfg->xSR[IMX_MU_GSR]);
471 
472 	print_hex_dump_debug("to client ", DUMP_PREFIX_OFFSET, 4, 4,
473 			     &msg, byte_size, false);
474 
475 	/* send data to client */
476 	dev_dbg(priv->dev, "Sending message to client\n");
477 	mbox_chan_received_data(cp->chan, (void *)&msg);
478 
479 	goto exit;
480 
481 error:
482 	mbox_chan_received_data(cp->chan, ERR_PTR(err));
483 
484 exit:
485 	return err;
486 }
487 
488 static void imx_mu_txdb_work(struct work_struct *t)
489 {
490 	struct imx_mu_con_priv *cp = from_work(cp, t, txdb_work);
491 
492 	mbox_chan_txdone(cp->chan, 0);
493 }
494 
495 static irqreturn_t imx_mu_isr(int irq, void *p)
496 {
497 	struct mbox_chan *chan = p;
498 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
499 	struct imx_mu_con_priv *cp = chan->con_priv;
500 	u32 val, ctrl;
501 
502 	switch (cp->type) {
503 	case IMX_MU_TYPE_TX:
504 		ctrl = imx_mu_read(priv, priv->dcfg->xCR[IMX_MU_TCR]);
505 		val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_TSR]);
506 		val &= IMX_MU_xSR_TEn(priv->dcfg->type, cp->idx) &
507 			(ctrl & IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx));
508 		break;
509 	case IMX_MU_TYPE_RX:
510 		ctrl = imx_mu_read(priv, priv->dcfg->xCR[IMX_MU_RCR]);
511 		val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_RSR]);
512 		val &= IMX_MU_xSR_RFn(priv->dcfg->type, cp->idx) &
513 			(ctrl & IMX_MU_xCR_RIEn(priv->dcfg->type, cp->idx));
514 		break;
515 	case IMX_MU_TYPE_RXDB:
516 		ctrl = imx_mu_read(priv, priv->dcfg->xCR[IMX_MU_GIER]);
517 		val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_GSR]);
518 		val &= IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx) &
519 			(ctrl & IMX_MU_xCR_GIEn(priv->dcfg->type, cp->idx));
520 		break;
521 	case IMX_MU_TYPE_RST:
522 		return IRQ_NONE;
523 	default:
524 		dev_warn_ratelimited(priv->dev, "Unhandled channel type %d\n",
525 				     cp->type);
526 		return IRQ_NONE;
527 	}
528 
529 	if (!val)
530 		return IRQ_NONE;
531 
532 	if ((val == IMX_MU_xSR_TEn(priv->dcfg->type, cp->idx)) &&
533 	    (cp->type == IMX_MU_TYPE_TX)) {
534 		imx_mu_xcr_rmw(priv, IMX_MU_TCR, 0, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx));
535 		mbox_chan_txdone(chan, 0);
536 	} else if ((val == IMX_MU_xSR_RFn(priv->dcfg->type, cp->idx)) &&
537 		   (cp->type == IMX_MU_TYPE_RX)) {
538 		priv->dcfg->rx(priv, cp);
539 	} else if ((val == IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx)) &&
540 		   (cp->type == IMX_MU_TYPE_RXDB)) {
541 		priv->dcfg->rxdb(priv, cp);
542 	} else {
543 		dev_warn_ratelimited(priv->dev, "Not handled interrupt\n");
544 		return IRQ_NONE;
545 	}
546 
547 	if (priv->suspend)
548 		pm_system_wakeup();
549 
550 	return IRQ_HANDLED;
551 }
552 
553 static int imx_mu_send_data(struct mbox_chan *chan, void *data)
554 {
555 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
556 	struct imx_mu_con_priv *cp = chan->con_priv;
557 
558 	return priv->dcfg->tx(priv, cp, data);
559 }
560 
561 static int imx_mu_startup(struct mbox_chan *chan)
562 {
563 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
564 	struct imx_mu_con_priv *cp = chan->con_priv;
565 	unsigned long irq_flag = 0;
566 	int ret;
567 
568 	pm_runtime_get_sync(priv->dev);
569 	if (cp->type == IMX_MU_TYPE_TXDB_V2)
570 		return 0;
571 
572 	if (cp->type == IMX_MU_TYPE_TXDB) {
573 		/* Tx doorbell don't have ACK support */
574 		INIT_WORK(&cp->txdb_work, imx_mu_txdb_work);
575 		return 0;
576 	}
577 
578 	/* IPC MU should be with IRQF_NO_SUSPEND set */
579 	if (!priv->dev->pm_domain)
580 		irq_flag |= IRQF_NO_SUSPEND;
581 
582 	if (!(priv->dcfg->type & IMX_MU_V2_IRQ))
583 		irq_flag |= IRQF_SHARED;
584 
585 	ret = request_irq(priv->irq[cp->type], imx_mu_isr, irq_flag, cp->irq_desc, chan);
586 	if (ret) {
587 		dev_err(priv->dev, "Unable to acquire IRQ %d\n", priv->irq[cp->type]);
588 		return ret;
589 	}
590 
591 	switch (cp->type) {
592 	case IMX_MU_TYPE_RX:
593 		imx_mu_xcr_rmw(priv, IMX_MU_RCR, IMX_MU_xCR_RIEn(priv->dcfg->type, cp->idx), 0);
594 		break;
595 	case IMX_MU_TYPE_RXDB:
596 		imx_mu_xcr_rmw(priv, IMX_MU_GIER, IMX_MU_xCR_GIEn(priv->dcfg->type, cp->idx), 0);
597 		break;
598 	default:
599 		break;
600 	}
601 
602 	return 0;
603 }
604 
605 static void imx_mu_shutdown(struct mbox_chan *chan)
606 {
607 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
608 	struct imx_mu_con_priv *cp = chan->con_priv;
609 	int ret;
610 	u32 sr;
611 
612 	if (cp->type == IMX_MU_TYPE_TXDB_V2) {
613 		pm_runtime_put_sync(priv->dev);
614 		return;
615 	}
616 
617 	if (cp->type == IMX_MU_TYPE_TXDB) {
618 		cancel_work_sync(&cp->txdb_work);
619 		pm_runtime_put_sync(priv->dev);
620 		return;
621 	}
622 
623 	switch (cp->type) {
624 	case IMX_MU_TYPE_TX:
625 		imx_mu_xcr_rmw(priv, IMX_MU_TCR, 0, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx));
626 		break;
627 	case IMX_MU_TYPE_RX:
628 		imx_mu_xcr_rmw(priv, IMX_MU_RCR, 0, IMX_MU_xCR_RIEn(priv->dcfg->type, cp->idx));
629 		break;
630 	case IMX_MU_TYPE_RXDB:
631 		imx_mu_xcr_rmw(priv, IMX_MU_GIER, 0, IMX_MU_xCR_GIEn(priv->dcfg->type, cp->idx));
632 		break;
633 	case IMX_MU_TYPE_RST:
634 		imx_mu_xcr_rmw(priv, IMX_MU_CR, IMX_MU_xCR_RST(priv->dcfg->type), 0);
635 		ret = readl_poll_timeout(priv->base + priv->dcfg->xSR[IMX_MU_SR], sr,
636 					 !(sr & IMX_MU_xSR_RST(priv->dcfg->type)), 1, 5);
637 		if (ret)
638 			dev_warn(priv->dev, "RST channel timeout\n");
639 		break;
640 	default:
641 		break;
642 	}
643 
644 	free_irq(priv->irq[cp->type], chan);
645 	pm_runtime_put_sync(priv->dev);
646 }
647 
648 static const struct mbox_chan_ops imx_mu_ops = {
649 	.send_data = imx_mu_send_data,
650 	.startup = imx_mu_startup,
651 	.shutdown = imx_mu_shutdown,
652 };
653 
654 static struct mbox_chan *imx_mu_specific_xlate(struct mbox_controller *mbox,
655 					       const struct of_phandle_args *sp)
656 {
657 	u32 type, idx, chan;
658 
659 	if (sp->args_count != 2) {
660 		dev_err(mbox->dev, "Invalid argument count %d\n", sp->args_count);
661 		return ERR_PTR(-EINVAL);
662 	}
663 
664 	type = sp->args[0]; /* channel type */
665 	idx = sp->args[1]; /* index */
666 
667 	switch (type) {
668 	case IMX_MU_TYPE_TX:
669 	case IMX_MU_TYPE_RX:
670 		if (idx != 0)
671 			dev_err(mbox->dev, "Invalid chan idx: %d\n", idx);
672 		chan = type;
673 		break;
674 	case IMX_MU_TYPE_RXDB:
675 		chan = 2 + idx;
676 		break;
677 	default:
678 		dev_err(mbox->dev, "Invalid chan type: %d\n", type);
679 		return ERR_PTR(-EINVAL);
680 	}
681 
682 	if (chan >= mbox->num_chans) {
683 		dev_err(mbox->dev, "Not supported channel number: %d. (type: %d, idx: %d)\n", chan, type, idx);
684 		return ERR_PTR(-EINVAL);
685 	}
686 
687 	return &mbox->chans[chan];
688 }
689 
690 static struct mbox_chan * imx_mu_xlate(struct mbox_controller *mbox,
691 				       const struct of_phandle_args *sp)
692 {
693 	struct mbox_chan *p_chan;
694 	u32 type, idx, chan;
695 
696 	if (sp->args_count != 2) {
697 		dev_err(mbox->dev, "Invalid argument count %d\n", sp->args_count);
698 		return ERR_PTR(-EINVAL);
699 	}
700 
701 	type = sp->args[0]; /* channel type */
702 	idx = sp->args[1]; /* index */
703 
704 	/* RST only supports 1 channel */
705 	if ((type == IMX_MU_TYPE_RST) && idx) {
706 		dev_err(mbox->dev, "Invalid RST channel %d\n", idx);
707 		return ERR_PTR(-EINVAL);
708 	}
709 
710 	chan = type * 4 + idx;
711 	if (chan >= mbox->num_chans) {
712 		dev_err(mbox->dev, "Not supported channel number: %d. (type: %d, idx: %d)\n", chan, type, idx);
713 		return ERR_PTR(-EINVAL);
714 	}
715 
716 	p_chan = &mbox->chans[chan];
717 
718 	if (type == IMX_MU_TYPE_TXDB_V2)
719 		p_chan->txdone_method = TXDONE_BY_ACK;
720 
721 	return p_chan;
722 }
723 
724 static struct mbox_chan *imx_mu_seco_xlate(struct mbox_controller *mbox,
725 					   const struct of_phandle_args *sp)
726 {
727 	u32 type;
728 
729 	if (sp->args_count < 1) {
730 		dev_err(mbox->dev, "Invalid argument count %d\n", sp->args_count);
731 		return ERR_PTR(-EINVAL);
732 	}
733 
734 	type = sp->args[0]; /* channel type */
735 
736 	/* Only supports TXDB and RXDB */
737 	if (type == IMX_MU_TYPE_TX || type == IMX_MU_TYPE_RX) {
738 		dev_err(mbox->dev, "Invalid type: %d\n", type);
739 		return ERR_PTR(-EINVAL);
740 	}
741 
742 	return imx_mu_xlate(mbox, sp);
743 }
744 
745 static void imx_mu_get_tr_rr(struct imx_mu_priv *priv)
746 {
747 	u32 val;
748 
749 	if (priv->dcfg->type & IMX_MU_V2) {
750 		val = imx_mu_read(priv, IMX_MU_V2_PAR_OFF);
751 		priv->num_tr = FIELD_GET(IMX_MU_V2_TR_MASK, val);
752 		priv->num_rr = FIELD_GET(IMX_MU_V2_RR_MASK, val);
753 	} else {
754 		priv->num_tr = 4;
755 		priv->num_rr = 4;
756 	}
757 }
758 
759 static int imx_mu_init_generic(struct imx_mu_priv *priv)
760 {
761 	unsigned int i;
762 	unsigned int val;
763 
764 	if (priv->num_rr > 4 || priv->num_tr > 4) {
765 		WARN_ONCE(true, "%s not support TR/RR larger than 4\n", __func__);
766 		return -EOPNOTSUPP;
767 	}
768 
769 	for (i = 0; i < IMX_MU_CHANS; i++) {
770 		struct imx_mu_con_priv *cp = &priv->con_priv[i];
771 
772 		cp->idx = i % 4;
773 		cp->type = i >> 2;
774 		cp->chan = &priv->mbox_chans[i];
775 		priv->mbox_chans[i].con_priv = cp;
776 		snprintf(cp->irq_desc, sizeof(cp->irq_desc),
777 			 "imx_mu_chan[%i-%i]", cp->type, cp->idx);
778 	}
779 
780 	priv->mbox.num_chans = IMX_MU_CHANS;
781 	priv->mbox.of_xlate = imx_mu_xlate;
782 
783 	if (priv->side_b)
784 		return 0;
785 
786 	/* Set default MU configuration */
787 	for (i = 0; i < IMX_MU_xCR_MAX; i++)
788 		imx_mu_write(priv, 0, priv->dcfg->xCR[i]);
789 
790 	/* Clear any pending GIP */
791 	val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_GSR]);
792 	imx_mu_write(priv, val, priv->dcfg->xSR[IMX_MU_GSR]);
793 
794 	/* Clear any pending RSR */
795 	for (i = 0; i < priv->num_rr; i++)
796 		imx_mu_read(priv, priv->dcfg->xRR + i * 4);
797 
798 	return 0;
799 }
800 
801 static int imx_mu_init_specific(struct imx_mu_priv *priv)
802 {
803 	unsigned int i;
804 	int num_chans = priv->dcfg->type & IMX_MU_V2_S4 ? IMX_MU_S4_CHANS : IMX_MU_SCU_CHANS;
805 
806 	for (i = 0; i < num_chans; i++) {
807 		struct imx_mu_con_priv *cp = &priv->con_priv[i];
808 
809 		cp->idx = i < 2 ? 0 : i - 2;
810 		cp->type = i < 2 ? i : IMX_MU_TYPE_RXDB;
811 		cp->chan = &priv->mbox_chans[i];
812 		priv->mbox_chans[i].con_priv = cp;
813 		snprintf(cp->irq_desc, sizeof(cp->irq_desc),
814 			 "imx_mu_chan[%i-%i]", cp->type, cp->idx);
815 	}
816 
817 	priv->mbox.num_chans = num_chans;
818 	priv->mbox.of_xlate = imx_mu_specific_xlate;
819 
820 	/* Set default MU configuration */
821 	for (i = 0; i < IMX_MU_xCR_MAX; i++)
822 		imx_mu_write(priv, 0, priv->dcfg->xCR[i]);
823 
824 	return 0;
825 }
826 
827 static int imx_mu_init_seco(struct imx_mu_priv *priv)
828 {
829 	int ret;
830 
831 	ret = imx_mu_init_generic(priv);
832 	if (ret)
833 		return ret;
834 	priv->mbox.of_xlate = imx_mu_seco_xlate;
835 
836 	return 0;
837 }
838 
839 static int imx_mu_probe(struct platform_device *pdev)
840 {
841 	struct device *dev = &pdev->dev;
842 	struct device_node *np = dev->of_node;
843 	struct imx_mu_priv *priv;
844 	const struct imx_mu_dcfg *dcfg;
845 	int i, ret;
846 	u32 size;
847 
848 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
849 	if (!priv)
850 		return -ENOMEM;
851 
852 	priv->dev = dev;
853 
854 	priv->base = devm_platform_ioremap_resource(pdev, 0);
855 	if (IS_ERR(priv->base))
856 		return PTR_ERR(priv->base);
857 
858 	dcfg = of_device_get_match_data(dev);
859 	if (!dcfg)
860 		return -EINVAL;
861 	priv->dcfg = dcfg;
862 	if (priv->dcfg->type & IMX_MU_V2_IRQ) {
863 		priv->irq[IMX_MU_TYPE_TX] = platform_get_irq_byname(pdev, "tx");
864 		if (priv->irq[IMX_MU_TYPE_TX] < 0)
865 			return priv->irq[IMX_MU_TYPE_TX];
866 		priv->irq[IMX_MU_TYPE_RX] = platform_get_irq_byname(pdev, "rx");
867 		if (priv->irq[IMX_MU_TYPE_RX] < 0)
868 			return priv->irq[IMX_MU_TYPE_RX];
869 	} else {
870 		ret = platform_get_irq(pdev, 0);
871 		if (ret < 0)
872 			return ret;
873 
874 		for (i = 0; i < IMX_MU_CHANS; i++)
875 			priv->irq[i] = ret;
876 	}
877 
878 	if (priv->dcfg->type & IMX_MU_V2_S4)
879 		size = sizeof(struct imx_s4_rpc_msg_max);
880 	else
881 		size = sizeof(struct imx_sc_rpc_msg_max);
882 
883 	priv->msg = devm_kzalloc(dev, size, GFP_KERNEL);
884 	if (!priv->msg)
885 		return -ENOMEM;
886 
887 	priv->clk = devm_clk_get(dev, NULL);
888 	if (IS_ERR(priv->clk)) {
889 		if (PTR_ERR(priv->clk) != -ENOENT)
890 			return PTR_ERR(priv->clk);
891 
892 		priv->clk = NULL;
893 	}
894 
895 	ret = clk_prepare_enable(priv->clk);
896 	if (ret) {
897 		dev_err(dev, "Failed to enable clock\n");
898 		return ret;
899 	}
900 
901 	imx_mu_get_tr_rr(priv);
902 
903 	priv->side_b = of_property_read_bool(np, "fsl,mu-side-b");
904 
905 	ret = priv->dcfg->init(priv);
906 	if (ret) {
907 		dev_err(dev, "Failed to init MU\n");
908 		goto disable_clk;
909 	}
910 
911 	spin_lock_init(&priv->xcr_lock);
912 
913 	priv->mbox.dev = dev;
914 	priv->mbox.ops = &imx_mu_ops;
915 	priv->mbox.chans = priv->mbox_chans;
916 	priv->mbox.txdone_irq = true;
917 
918 	platform_set_drvdata(pdev, priv);
919 
920 	ret = devm_mbox_controller_register(dev, &priv->mbox);
921 	if (ret)
922 		goto disable_clk;
923 
924 	of_platform_populate(dev->of_node, NULL, NULL, dev);
925 
926 	pm_runtime_enable(dev);
927 
928 	ret = pm_runtime_resume_and_get(dev);
929 	if (ret < 0)
930 		goto disable_runtime_pm;
931 
932 	ret = pm_runtime_put_sync(dev);
933 	if (ret < 0)
934 		goto disable_runtime_pm;
935 
936 	clk_disable_unprepare(priv->clk);
937 
938 	return 0;
939 
940 disable_runtime_pm:
941 	pm_runtime_disable(dev);
942 disable_clk:
943 	clk_disable_unprepare(priv->clk);
944 	return ret;
945 }
946 
947 static void imx_mu_remove(struct platform_device *pdev)
948 {
949 	struct imx_mu_priv *priv = platform_get_drvdata(pdev);
950 
951 	pm_runtime_disable(priv->dev);
952 }
953 
954 static const struct imx_mu_dcfg imx_mu_cfg_imx6sx = {
955 	.tx	= imx_mu_generic_tx,
956 	.rx	= imx_mu_generic_rx,
957 	.rxdb	= imx_mu_generic_rxdb,
958 	.init	= imx_mu_init_generic,
959 	.xTR	= 0x0,
960 	.xRR	= 0x10,
961 	.xSR	= {0x20, 0x20, 0x20, 0x20},
962 	.xCR	= {0x24, 0x24, 0x24, 0x24, 0x24},
963 };
964 
965 static const struct imx_mu_dcfg imx_mu_cfg_imx7ulp = {
966 	.tx	= imx_mu_generic_tx,
967 	.rx	= imx_mu_generic_rx,
968 	.rxdb	= imx_mu_generic_rxdb,
969 	.init	= imx_mu_init_generic,
970 	.xTR	= 0x20,
971 	.xRR	= 0x40,
972 	.xSR	= {0x60, 0x60, 0x60, 0x60},
973 	.xCR	= {0x64, 0x64, 0x64, 0x64, 0x64},
974 };
975 
976 static const struct imx_mu_dcfg imx_mu_cfg_imx8ulp = {
977 	.tx	= imx_mu_generic_tx,
978 	.rx	= imx_mu_generic_rx,
979 	.rxdb	= imx_mu_generic_rxdb,
980 	.init	= imx_mu_init_generic,
981 	.type	= IMX_MU_V2,
982 	.xTR	= 0x200,
983 	.xRR	= 0x280,
984 	.xSR	= {0xC, 0x118, 0x124, 0x12C},
985 	.xCR	= {0x8, 0x110, 0x114, 0x120, 0x128},
986 };
987 
988 static const struct imx_mu_dcfg imx_mu_cfg_imx8ulp_s4 = {
989 	.tx	= imx_mu_specific_tx,
990 	.rx	= imx_mu_specific_rx,
991 	.init	= imx_mu_init_specific,
992 	.type	= IMX_MU_V2 | IMX_MU_V2_S4,
993 	.xTR	= 0x200,
994 	.xRR	= 0x280,
995 	.xSR	= {0xC, 0x118, 0x124, 0x12C},
996 	.xCR	= {0x8, 0x110, 0x114, 0x120, 0x128},
997 };
998 
999 static const struct imx_mu_dcfg imx_mu_cfg_imx93_s4 = {
1000 	.tx	= imx_mu_specific_tx,
1001 	.rx	= imx_mu_specific_rx,
1002 	.init	= imx_mu_init_specific,
1003 	.type	= IMX_MU_V2 | IMX_MU_V2_S4 | IMX_MU_V2_IRQ,
1004 	.xTR	= 0x200,
1005 	.xRR	= 0x280,
1006 	.xSR	= {0xC, 0x118, 0x124, 0x12C},
1007 	.xCR	= {0x8, 0x110, 0x114, 0x120, 0x128},
1008 };
1009 
1010 static const struct imx_mu_dcfg imx_mu_cfg_imx8_scu = {
1011 	.tx	= imx_mu_specific_tx,
1012 	.rx	= imx_mu_specific_rx,
1013 	.init	= imx_mu_init_specific,
1014 	.rxdb	= imx_mu_generic_rxdb,
1015 	.xTR	= 0x0,
1016 	.xRR	= 0x10,
1017 	.xSR	= {0x20, 0x20, 0x20, 0x20},
1018 	.xCR	= {0x24, 0x24, 0x24, 0x24, 0x24},
1019 };
1020 
1021 static const struct imx_mu_dcfg imx_mu_cfg_imx8_seco = {
1022 	.tx	= imx_mu_seco_tx,
1023 	.rx	= imx_mu_generic_rx,
1024 	.rxdb	= imx_mu_seco_rxdb,
1025 	.init	= imx_mu_init_seco,
1026 	.xTR	= 0x0,
1027 	.xRR	= 0x10,
1028 	.xSR	= {0x20, 0x20, 0x20, 0x20},
1029 	.xCR	= {0x24, 0x24, 0x24, 0x24, 0x24},
1030 };
1031 
1032 static const struct of_device_id imx_mu_dt_ids[] = {
1033 	{ .compatible = "fsl,imx7ulp-mu", .data = &imx_mu_cfg_imx7ulp },
1034 	{ .compatible = "fsl,imx6sx-mu", .data = &imx_mu_cfg_imx6sx },
1035 	{ .compatible = "fsl,imx8ulp-mu", .data = &imx_mu_cfg_imx8ulp },
1036 	{ .compatible = "fsl,imx8ulp-mu-s4", .data = &imx_mu_cfg_imx8ulp_s4 },
1037 	{ .compatible = "fsl,imx93-mu-s4", .data = &imx_mu_cfg_imx93_s4 },
1038 	{ .compatible = "fsl,imx95-mu", .data = &imx_mu_cfg_imx8ulp },
1039 	{ .compatible = "fsl,imx95-mu-ele", .data = &imx_mu_cfg_imx8ulp_s4 },
1040 	{ .compatible = "fsl,imx95-mu-v2x", .data = &imx_mu_cfg_imx8ulp_s4 },
1041 	{ .compatible = "fsl,imx8-mu-scu", .data = &imx_mu_cfg_imx8_scu },
1042 	{ .compatible = "fsl,imx8-mu-seco", .data = &imx_mu_cfg_imx8_seco },
1043 	{ },
1044 };
1045 MODULE_DEVICE_TABLE(of, imx_mu_dt_ids);
1046 
1047 static int __maybe_unused imx_mu_suspend_noirq(struct device *dev)
1048 {
1049 	struct imx_mu_priv *priv = dev_get_drvdata(dev);
1050 	int i;
1051 
1052 	if (!priv->clk) {
1053 		for (i = 0; i < IMX_MU_xCR_MAX; i++)
1054 			priv->xcr[i] = imx_mu_read(priv, priv->dcfg->xCR[i]);
1055 	}
1056 
1057 	priv->suspend = true;
1058 
1059 	return 0;
1060 }
1061 
1062 static int __maybe_unused imx_mu_resume_noirq(struct device *dev)
1063 {
1064 	struct imx_mu_priv *priv = dev_get_drvdata(dev);
1065 	int i;
1066 
1067 	/*
1068 	 * ONLY restore MU when context lost, the TIE could
1069 	 * be set during noirq resume as there is MU data
1070 	 * communication going on, and restore the saved
1071 	 * value will overwrite the TIE and cause MU data
1072 	 * send failed, may lead to system freeze. This issue
1073 	 * is observed by testing freeze mode suspend.
1074 	 */
1075 	if (!priv->clk && !imx_mu_read(priv, priv->dcfg->xCR[0])) {
1076 		for (i = 0; i < IMX_MU_xCR_MAX; i++)
1077 			imx_mu_write(priv, priv->xcr[i], priv->dcfg->xCR[i]);
1078 	}
1079 
1080 	priv->suspend = false;
1081 
1082 	return 0;
1083 }
1084 
1085 static int __maybe_unused imx_mu_runtime_suspend(struct device *dev)
1086 {
1087 	struct imx_mu_priv *priv = dev_get_drvdata(dev);
1088 
1089 	clk_disable_unprepare(priv->clk);
1090 
1091 	return 0;
1092 }
1093 
1094 static int __maybe_unused imx_mu_runtime_resume(struct device *dev)
1095 {
1096 	struct imx_mu_priv *priv = dev_get_drvdata(dev);
1097 	int ret;
1098 
1099 	ret = clk_prepare_enable(priv->clk);
1100 	if (ret)
1101 		dev_err(dev, "failed to enable clock\n");
1102 
1103 	return ret;
1104 }
1105 
1106 static const struct dev_pm_ops imx_mu_pm_ops = {
1107 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx_mu_suspend_noirq,
1108 				      imx_mu_resume_noirq)
1109 	SET_RUNTIME_PM_OPS(imx_mu_runtime_suspend,
1110 			   imx_mu_runtime_resume, NULL)
1111 };
1112 
1113 static struct platform_driver imx_mu_driver = {
1114 	.probe		= imx_mu_probe,
1115 	.remove_new	= imx_mu_remove,
1116 	.driver = {
1117 		.name	= "imx_mu",
1118 		.of_match_table = imx_mu_dt_ids,
1119 		.pm = &imx_mu_pm_ops,
1120 	},
1121 };
1122 module_platform_driver(imx_mu_driver);
1123 
1124 MODULE_AUTHOR("Oleksij Rempel <o.rempel@pengutronix.de>");
1125 MODULE_DESCRIPTION("Message Unit driver for i.MX");
1126 MODULE_LICENSE("GPL v2");
1127