xref: /linux/drivers/mailbox/imx-mailbox.c (revision b1992c3772e69a6fd0e3fc81cd4d2820c8b6eca0)
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 
25 #include "mailbox.h"
26 
27 #define IMX_MU_CHANS		24
28 /* TX0/RX0/RXDB[0-3] */
29 #define IMX_MU_SCU_CHANS	6
30 /* TX0/RX0 */
31 #define IMX_MU_S4_CHANS		2
32 #define IMX_MU_CHAN_NAME_SIZE	20
33 
34 #define IMX_MU_V2_PAR_OFF	0x4
35 #define IMX_MU_V2_TR_MASK	GENMASK(7, 0)
36 #define IMX_MU_V2_RR_MASK	GENMASK(15, 8)
37 
38 #define IMX_MU_SECO_TX_TOUT (msecs_to_jiffies(3000))
39 #define IMX_MU_SECO_RX_TOUT (msecs_to_jiffies(3000))
40 
41 /* Please not change TX & RX */
42 enum imx_mu_chan_type {
43 	IMX_MU_TYPE_TX		= 0, /* Tx */
44 	IMX_MU_TYPE_RX		= 1, /* Rx */
45 	IMX_MU_TYPE_TXDB	= 2, /* Tx doorbell */
46 	IMX_MU_TYPE_RXDB	= 3, /* Rx doorbell */
47 	IMX_MU_TYPE_RST		= 4, /* Reset */
48 	IMX_MU_TYPE_TXDB_V2	= 5, /* Tx doorbell with S/W ACK */
49 };
50 
51 enum imx_mu_xcr {
52 	IMX_MU_CR,
53 	IMX_MU_GIER,
54 	IMX_MU_GCR,
55 	IMX_MU_TCR,
56 	IMX_MU_RCR,
57 	IMX_MU_xCR_MAX,
58 };
59 
60 enum imx_mu_xsr {
61 	IMX_MU_SR,
62 	IMX_MU_GSR,
63 	IMX_MU_TSR,
64 	IMX_MU_RSR,
65 	IMX_MU_xSR_MAX,
66 };
67 
68 struct imx_sc_rpc_msg_max {
69 	struct imx_sc_rpc_msg hdr;
70 	u32 data[30];
71 };
72 
73 struct imx_s4_rpc_msg_max {
74 	struct imx_s4_rpc_msg hdr;
75 	u32 data[254];
76 };
77 
78 struct imx_mu_con_priv {
79 	unsigned int		idx;
80 	char			irq_desc[IMX_MU_CHAN_NAME_SIZE];
81 	enum imx_mu_chan_type	type;
82 	struct mbox_chan	*chan;
83 	struct tasklet_struct	txdb_tasklet;
84 };
85 
86 struct imx_mu_priv {
87 	struct device		*dev;
88 	void __iomem		*base;
89 	void			*msg;
90 	spinlock_t		xcr_lock; /* control register lock */
91 
92 	struct mbox_controller	mbox;
93 	struct mbox_chan	mbox_chans[IMX_MU_CHANS];
94 
95 	struct imx_mu_con_priv  con_priv[IMX_MU_CHANS];
96 	const struct imx_mu_dcfg	*dcfg;
97 	struct clk		*clk;
98 	int			irq[IMX_MU_CHANS];
99 	bool			suspend;
100 	bool			side_b;
101 
102 	u32			xcr[IMX_MU_xCR_MAX];
103 	u32			num_tr;
104 	u32			num_rr;
105 };
106 
107 enum imx_mu_type {
108 	IMX_MU_V1,
109 	IMX_MU_V2 = BIT(1),
110 	IMX_MU_V2_S4 = BIT(15),
111 	IMX_MU_V2_IRQ = BIT(16),
112 };
113 
114 struct imx_mu_dcfg {
115 	int (*tx)(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp, void *data);
116 	int (*rx)(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp);
117 	int (*rxdb)(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp);
118 	int (*init)(struct imx_mu_priv *priv);
119 	enum imx_mu_type type;
120 	u32	xTR;		/* Transmit Register0 */
121 	u32	xRR;		/* Receive Register0 */
122 	u32	xSR[IMX_MU_xSR_MAX];	/* Status Registers */
123 	u32	xCR[IMX_MU_xCR_MAX];	/* Control Registers */
124 };
125 
126 #define IMX_MU_xSR_GIPn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(28 + (3 - (x))))
127 #define IMX_MU_xSR_RFn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(24 + (3 - (x))))
128 #define IMX_MU_xSR_TEn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(20 + (3 - (x))))
129 
130 /* General Purpose Interrupt Enable */
131 #define IMX_MU_xCR_GIEn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(28 + (3 - (x))))
132 /* Receive Interrupt Enable */
133 #define IMX_MU_xCR_RIEn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(24 + (3 - (x))))
134 /* Transmit Interrupt Enable */
135 #define IMX_MU_xCR_TIEn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(20 + (3 - (x))))
136 /* General Purpose Interrupt Request */
137 #define IMX_MU_xCR_GIRn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(16 + (3 - (x))))
138 /* MU reset */
139 #define IMX_MU_xCR_RST(type)	(type & IMX_MU_V2 ? BIT(0) : BIT(5))
140 #define IMX_MU_xSR_RST(type)	(type & IMX_MU_V2 ? BIT(0) : BIT(7))
141 
142 
143 static struct imx_mu_priv *to_imx_mu_priv(struct mbox_controller *mbox)
144 {
145 	return container_of(mbox, struct imx_mu_priv, mbox);
146 }
147 
148 static void imx_mu_write(struct imx_mu_priv *priv, u32 val, u32 offs)
149 {
150 	iowrite32(val, priv->base + offs);
151 }
152 
153 static u32 imx_mu_read(struct imx_mu_priv *priv, u32 offs)
154 {
155 	return ioread32(priv->base + offs);
156 }
157 
158 static int imx_mu_tx_waiting_write(struct imx_mu_priv *priv, u32 val, u32 idx)
159 {
160 	u64 timeout_time = get_jiffies_64() + IMX_MU_SECO_TX_TOUT;
161 	u32 status;
162 	u32 can_write;
163 
164 	dev_dbg(priv->dev, "Trying to write %.8x to idx %d\n", val, idx);
165 
166 	do {
167 		status = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_TSR]);
168 		can_write = status & IMX_MU_xSR_TEn(priv->dcfg->type, idx % 4);
169 	} while (!can_write && time_is_after_jiffies64(timeout_time));
170 
171 	if (!can_write) {
172 		dev_err(priv->dev, "timeout trying to write %.8x at %d(%.8x)\n",
173 			val, idx, status);
174 		return -ETIME;
175 	}
176 
177 	imx_mu_write(priv, val, priv->dcfg->xTR + (idx % 4) * 4);
178 
179 	return 0;
180 }
181 
182 static int imx_mu_rx_waiting_read(struct imx_mu_priv *priv, u32 *val, u32 idx)
183 {
184 	u64 timeout_time = get_jiffies_64() + IMX_MU_SECO_RX_TOUT;
185 	u32 status;
186 	u32 can_read;
187 
188 	dev_dbg(priv->dev, "Trying to read from idx %d\n", idx);
189 
190 	do {
191 		status = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_RSR]);
192 		can_read = status & IMX_MU_xSR_RFn(priv->dcfg->type, idx % 4);
193 	} while (!can_read && time_is_after_jiffies64(timeout_time));
194 
195 	if (!can_read) {
196 		dev_err(priv->dev, "timeout trying to read idx %d (%.8x)\n",
197 			idx, status);
198 		return -ETIME;
199 	}
200 
201 	*val = imx_mu_read(priv, priv->dcfg->xRR + (idx % 4) * 4);
202 	dev_dbg(priv->dev, "Read %.8x\n", *val);
203 
204 	return 0;
205 }
206 
207 static u32 imx_mu_xcr_rmw(struct imx_mu_priv *priv, enum imx_mu_xcr type, u32 set, u32 clr)
208 {
209 	unsigned long flags;
210 	u32 val;
211 
212 	spin_lock_irqsave(&priv->xcr_lock, flags);
213 	val = imx_mu_read(priv, priv->dcfg->xCR[type]);
214 	val &= ~clr;
215 	val |= set;
216 	imx_mu_write(priv, val, priv->dcfg->xCR[type]);
217 	spin_unlock_irqrestore(&priv->xcr_lock, flags);
218 
219 	return val;
220 }
221 
222 static int imx_mu_generic_tx(struct imx_mu_priv *priv,
223 			     struct imx_mu_con_priv *cp,
224 			     void *data)
225 {
226 	u32 *arg = data;
227 
228 	switch (cp->type) {
229 	case IMX_MU_TYPE_TX:
230 		imx_mu_write(priv, *arg, priv->dcfg->xTR + cp->idx * 4);
231 		imx_mu_xcr_rmw(priv, IMX_MU_TCR, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx), 0);
232 		break;
233 	case IMX_MU_TYPE_TXDB:
234 		imx_mu_xcr_rmw(priv, IMX_MU_GCR, IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx), 0);
235 		tasklet_schedule(&cp->txdb_tasklet);
236 		break;
237 	case IMX_MU_TYPE_TXDB_V2:
238 		imx_mu_xcr_rmw(priv, IMX_MU_GCR, IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx), 0);
239 		break;
240 	default:
241 		dev_warn_ratelimited(priv->dev, "Send data on wrong channel type: %d\n", cp->type);
242 		return -EINVAL;
243 	}
244 
245 	return 0;
246 }
247 
248 static int imx_mu_generic_rx(struct imx_mu_priv *priv,
249 			     struct imx_mu_con_priv *cp)
250 {
251 	u32 dat;
252 
253 	dat = imx_mu_read(priv, priv->dcfg->xRR + (cp->idx) * 4);
254 	mbox_chan_received_data(cp->chan, (void *)&dat);
255 
256 	return 0;
257 }
258 
259 static int imx_mu_generic_rxdb(struct imx_mu_priv *priv,
260 			       struct imx_mu_con_priv *cp)
261 {
262 	imx_mu_write(priv, IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx),
263 		     priv->dcfg->xSR[IMX_MU_GSR]);
264 	mbox_chan_received_data(cp->chan, NULL);
265 
266 	return 0;
267 }
268 
269 static int imx_mu_specific_tx(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp, void *data)
270 {
271 	u32 *arg = data;
272 	u32 num_tr = priv->num_tr;
273 	int i, ret;
274 	u32 xsr;
275 	u32 size, max_size;
276 
277 	if (priv->dcfg->type & IMX_MU_V2_S4) {
278 		size = ((struct imx_s4_rpc_msg_max *)data)->hdr.size;
279 		max_size = sizeof(struct imx_s4_rpc_msg_max);
280 	} else {
281 		size = ((struct imx_sc_rpc_msg_max *)data)->hdr.size;
282 		max_size = sizeof(struct imx_sc_rpc_msg_max);
283 	}
284 
285 	switch (cp->type) {
286 	case IMX_MU_TYPE_TX:
287 		/*
288 		 * msg->hdr.size specifies the number of u32 words while
289 		 * sizeof yields bytes.
290 		 */
291 
292 		if (size > max_size / 4) {
293 			/*
294 			 * The real message size can be different to
295 			 * struct imx_sc_rpc_msg_max/imx_s4_rpc_msg_max size
296 			 */
297 			dev_err(priv->dev, "Maximal message size (%u bytes) exceeded on TX; got: %i bytes\n", max_size, size << 2);
298 			return -EINVAL;
299 		}
300 
301 		for (i = 0; i < num_tr && i < size; i++)
302 			imx_mu_write(priv, *arg++, priv->dcfg->xTR + (i % num_tr) * 4);
303 		for (; i < size; i++) {
304 			ret = readl_poll_timeout(priv->base + priv->dcfg->xSR[IMX_MU_TSR],
305 						 xsr,
306 						 xsr & IMX_MU_xSR_TEn(priv->dcfg->type, i % num_tr),
307 						 0, 5 * USEC_PER_SEC);
308 			if (ret) {
309 				dev_err(priv->dev, "Send data index: %d timeout\n", i);
310 				return ret;
311 			}
312 			imx_mu_write(priv, *arg++, priv->dcfg->xTR + (i % num_tr) * 4);
313 		}
314 
315 		imx_mu_xcr_rmw(priv, IMX_MU_TCR, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx), 0);
316 		break;
317 	default:
318 		dev_warn_ratelimited(priv->dev, "Send data on wrong channel type: %d\n", cp->type);
319 		return -EINVAL;
320 	}
321 
322 	return 0;
323 }
324 
325 static int imx_mu_specific_rx(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp)
326 {
327 	u32 *data;
328 	int i, ret;
329 	u32 xsr;
330 	u32 size, max_size;
331 	u32 num_rr = priv->num_rr;
332 
333 	data = (u32 *)priv->msg;
334 
335 	imx_mu_xcr_rmw(priv, IMX_MU_RCR, 0, IMX_MU_xCR_RIEn(priv->dcfg->type, 0));
336 	*data++ = imx_mu_read(priv, priv->dcfg->xRR);
337 
338 	if (priv->dcfg->type & IMX_MU_V2_S4) {
339 		size = ((struct imx_s4_rpc_msg_max *)priv->msg)->hdr.size;
340 		max_size = sizeof(struct imx_s4_rpc_msg_max);
341 	} else {
342 		size = ((struct imx_sc_rpc_msg_max *)priv->msg)->hdr.size;
343 		max_size = sizeof(struct imx_sc_rpc_msg_max);
344 	}
345 
346 	if (size > max_size / 4) {
347 		dev_err(priv->dev, "Maximal message size (%u bytes) exceeded on RX; got: %i bytes\n", max_size, size << 2);
348 		return -EINVAL;
349 	}
350 
351 	for (i = 1; i < size; i++) {
352 		ret = readl_poll_timeout(priv->base + priv->dcfg->xSR[IMX_MU_RSR], xsr,
353 					 xsr & IMX_MU_xSR_RFn(priv->dcfg->type, i % num_rr), 0,
354 					 5 * USEC_PER_SEC);
355 		if (ret) {
356 			dev_err(priv->dev, "timeout read idx %d\n", i);
357 			return ret;
358 		}
359 		*data++ = imx_mu_read(priv, priv->dcfg->xRR + (i % num_rr) * 4);
360 	}
361 
362 	imx_mu_xcr_rmw(priv, IMX_MU_RCR, IMX_MU_xCR_RIEn(priv->dcfg->type, 0), 0);
363 	mbox_chan_received_data(cp->chan, (void *)priv->msg);
364 
365 	return 0;
366 }
367 
368 static int imx_mu_seco_tx(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp,
369 			  void *data)
370 {
371 	struct imx_sc_rpc_msg_max *msg = data;
372 	u32 *arg = data;
373 	u32 byte_size;
374 	int err;
375 	int i;
376 
377 	dev_dbg(priv->dev, "Sending message\n");
378 
379 	switch (cp->type) {
380 	case IMX_MU_TYPE_TXDB:
381 		byte_size = msg->hdr.size * sizeof(u32);
382 		if (byte_size > sizeof(*msg)) {
383 			/*
384 			 * The real message size can be different to
385 			 * struct imx_sc_rpc_msg_max size
386 			 */
387 			dev_err(priv->dev,
388 				"Exceed max msg size (%zu) on TX, got: %i\n",
389 				sizeof(*msg), byte_size);
390 			return -EINVAL;
391 		}
392 
393 		print_hex_dump_debug("from client ", DUMP_PREFIX_OFFSET, 4, 4,
394 				     data, byte_size, false);
395 
396 		/* Send first word */
397 		dev_dbg(priv->dev, "Sending header\n");
398 		imx_mu_write(priv, *arg++, priv->dcfg->xTR);
399 
400 		/* Send signaling */
401 		dev_dbg(priv->dev, "Sending signaling\n");
402 		imx_mu_xcr_rmw(priv, IMX_MU_GCR,
403 			       IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx), 0);
404 
405 		/* Send words to fill the mailbox */
406 		for (i = 1; i < 4 && i < msg->hdr.size; i++) {
407 			dev_dbg(priv->dev, "Sending word %d\n", i);
408 			imx_mu_write(priv, *arg++,
409 				     priv->dcfg->xTR + (i % 4) * 4);
410 		}
411 
412 		/* Send rest of message waiting for remote read */
413 		for (; i < msg->hdr.size; i++) {
414 			dev_dbg(priv->dev, "Sending word %d\n", i);
415 			err = imx_mu_tx_waiting_write(priv, *arg++, i);
416 			if (err) {
417 				dev_err(priv->dev, "Timeout tx %d\n", i);
418 				return err;
419 			}
420 		}
421 
422 		/* Simulate hack for mbox framework */
423 		tasklet_schedule(&cp->txdb_tasklet);
424 
425 		break;
426 	default:
427 		dev_warn_ratelimited(priv->dev,
428 				     "Send data on wrong channel type: %d\n",
429 				     cp->type);
430 		return -EINVAL;
431 	}
432 
433 	return 0;
434 }
435 
436 static int imx_mu_seco_rxdb(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp)
437 {
438 	struct imx_sc_rpc_msg_max msg;
439 	u32 *data = (u32 *)&msg;
440 	u32 byte_size;
441 	int err = 0;
442 	int i;
443 
444 	dev_dbg(priv->dev, "Receiving message\n");
445 
446 	/* Read header */
447 	dev_dbg(priv->dev, "Receiving header\n");
448 	*data++ = imx_mu_read(priv, priv->dcfg->xRR);
449 	byte_size = msg.hdr.size * sizeof(u32);
450 	if (byte_size > sizeof(msg)) {
451 		dev_err(priv->dev, "Exceed max msg size (%zu) on RX, got: %i\n",
452 			sizeof(msg), byte_size);
453 		err = -EINVAL;
454 		goto error;
455 	}
456 
457 	/* Read message waiting they are written */
458 	for (i = 1; i < msg.hdr.size; i++) {
459 		dev_dbg(priv->dev, "Receiving word %d\n", i);
460 		err = imx_mu_rx_waiting_read(priv, data++, i);
461 		if (err) {
462 			dev_err(priv->dev, "Timeout rx %d\n", i);
463 			goto error;
464 		}
465 	}
466 
467 	/* Clear GIP */
468 	imx_mu_write(priv, IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx),
469 		     priv->dcfg->xSR[IMX_MU_GSR]);
470 
471 	print_hex_dump_debug("to client ", DUMP_PREFIX_OFFSET, 4, 4,
472 			     &msg, byte_size, false);
473 
474 	/* send data to client */
475 	dev_dbg(priv->dev, "Sending message to client\n");
476 	mbox_chan_received_data(cp->chan, (void *)&msg);
477 
478 	goto exit;
479 
480 error:
481 	mbox_chan_received_data(cp->chan, ERR_PTR(err));
482 
483 exit:
484 	return err;
485 }
486 
487 static void imx_mu_txdb_tasklet(unsigned long data)
488 {
489 	struct imx_mu_con_priv *cp = (struct imx_mu_con_priv *)data;
490 
491 	mbox_chan_txdone(cp->chan, 0);
492 }
493 
494 static irqreturn_t imx_mu_isr(int irq, void *p)
495 {
496 	struct mbox_chan *chan = p;
497 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
498 	struct imx_mu_con_priv *cp = chan->con_priv;
499 	u32 val, ctrl;
500 
501 	switch (cp->type) {
502 	case IMX_MU_TYPE_TX:
503 		ctrl = imx_mu_read(priv, priv->dcfg->xCR[IMX_MU_TCR]);
504 		val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_TSR]);
505 		val &= IMX_MU_xSR_TEn(priv->dcfg->type, cp->idx) &
506 			(ctrl & IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx));
507 		break;
508 	case IMX_MU_TYPE_RX:
509 		ctrl = imx_mu_read(priv, priv->dcfg->xCR[IMX_MU_RCR]);
510 		val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_RSR]);
511 		val &= IMX_MU_xSR_RFn(priv->dcfg->type, cp->idx) &
512 			(ctrl & IMX_MU_xCR_RIEn(priv->dcfg->type, cp->idx));
513 		break;
514 	case IMX_MU_TYPE_RXDB:
515 		ctrl = imx_mu_read(priv, priv->dcfg->xCR[IMX_MU_GIER]);
516 		val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_GSR]);
517 		val &= IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx) &
518 			(ctrl & IMX_MU_xCR_GIEn(priv->dcfg->type, cp->idx));
519 		break;
520 	case IMX_MU_TYPE_RST:
521 		return IRQ_NONE;
522 	default:
523 		dev_warn_ratelimited(priv->dev, "Unhandled channel type %d\n",
524 				     cp->type);
525 		return IRQ_NONE;
526 	}
527 
528 	if (!val)
529 		return IRQ_NONE;
530 
531 	if ((val == IMX_MU_xSR_TEn(priv->dcfg->type, cp->idx)) &&
532 	    (cp->type == IMX_MU_TYPE_TX)) {
533 		imx_mu_xcr_rmw(priv, IMX_MU_TCR, 0, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx));
534 		mbox_chan_txdone(chan, 0);
535 	} else if ((val == IMX_MU_xSR_RFn(priv->dcfg->type, cp->idx)) &&
536 		   (cp->type == IMX_MU_TYPE_RX)) {
537 		priv->dcfg->rx(priv, cp);
538 	} else if ((val == IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx)) &&
539 		   (cp->type == IMX_MU_TYPE_RXDB)) {
540 		priv->dcfg->rxdb(priv, cp);
541 	} else {
542 		dev_warn_ratelimited(priv->dev, "Not handled interrupt\n");
543 		return IRQ_NONE;
544 	}
545 
546 	if (priv->suspend)
547 		pm_system_wakeup();
548 
549 	return IRQ_HANDLED;
550 }
551 
552 static int imx_mu_send_data(struct mbox_chan *chan, void *data)
553 {
554 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
555 	struct imx_mu_con_priv *cp = chan->con_priv;
556 
557 	return priv->dcfg->tx(priv, cp, data);
558 }
559 
560 static int imx_mu_startup(struct mbox_chan *chan)
561 {
562 	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
563 	struct imx_mu_con_priv *cp = chan->con_priv;
564 	unsigned long irq_flag = 0;
565 	int ret;
566 
567 	pm_runtime_get_sync(priv->dev);
568 	if (cp->type == IMX_MU_TYPE_TXDB_V2)
569 		return 0;
570 
571 	if (cp->type == IMX_MU_TYPE_TXDB) {
572 		/* Tx doorbell don't have ACK support */
573 		tasklet_init(&cp->txdb_tasklet, imx_mu_txdb_tasklet,
574 			     (unsigned long)cp);
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 		tasklet_kill(&cp->txdb_tasklet);
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