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