1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * OMAP mailbox driver
4 *
5 * Copyright (C) 2006-2009 Nokia Corporation. All rights reserved.
6 * Copyright (C) 2013-2021 Texas Instruments Incorporated - https://www.ti.com
7 *
8 * Contact: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
9 * Suman Anna <s-anna@ti.com>
10 */
11
12 #include <linux/interrupt.h>
13 #include <linux/spinlock.h>
14 #include <linux/mutex.h>
15 #include <linux/slab.h>
16 #include <linux/kfifo.h>
17 #include <linux/err.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/platform_device.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/mailbox_controller.h>
23 #include <linux/mailbox_client.h>
24
25 #include "mailbox.h"
26
27 #define MAILBOX_REVISION 0x000
28 #define MAILBOX_MESSAGE(m) (0x040 + 4 * (m))
29 #define MAILBOX_FIFOSTATUS(m) (0x080 + 4 * (m))
30 #define MAILBOX_MSGSTATUS(m) (0x0c0 + 4 * (m))
31
32 #define OMAP2_MAILBOX_IRQSTATUS(u) (0x100 + 8 * (u))
33 #define OMAP2_MAILBOX_IRQENABLE(u) (0x104 + 8 * (u))
34
35 #define OMAP4_MAILBOX_IRQSTATUS(u) (0x104 + 0x10 * (u))
36 #define OMAP4_MAILBOX_IRQENABLE(u) (0x108 + 0x10 * (u))
37 #define OMAP4_MAILBOX_IRQENABLE_CLR(u) (0x10c + 0x10 * (u))
38
39 #define MAILBOX_IRQSTATUS(type, u) (type ? OMAP4_MAILBOX_IRQSTATUS(u) : \
40 OMAP2_MAILBOX_IRQSTATUS(u))
41 #define MAILBOX_IRQENABLE(type, u) (type ? OMAP4_MAILBOX_IRQENABLE(u) : \
42 OMAP2_MAILBOX_IRQENABLE(u))
43 #define MAILBOX_IRQDISABLE(type, u) (type ? OMAP4_MAILBOX_IRQENABLE_CLR(u) \
44 : OMAP2_MAILBOX_IRQENABLE(u))
45
46 #define MAILBOX_IRQ_NEWMSG(m) (1 << (2 * (m)))
47 #define MAILBOX_IRQ_NOTFULL(m) (1 << (2 * (m) + 1))
48
49 /* Interrupt register configuration types */
50 #define MBOX_INTR_CFG_TYPE1 0
51 #define MBOX_INTR_CFG_TYPE2 1
52
53 typedef enum {
54 IRQ_TX = 1,
55 IRQ_RX = 2,
56 } omap_mbox_irq_t;
57
58 struct omap_mbox_fifo {
59 unsigned long msg;
60 unsigned long fifo_stat;
61 unsigned long msg_stat;
62 unsigned long irqenable;
63 unsigned long irqstatus;
64 unsigned long irqdisable;
65 u32 intr_bit;
66 };
67
68 struct omap_mbox_match_data {
69 u32 intr_type;
70 };
71
72 struct omap_mbox_device {
73 struct device *dev;
74 struct mutex cfg_lock;
75 void __iomem *mbox_base;
76 u32 *irq_ctx;
77 u32 num_users;
78 u32 num_fifos;
79 u32 intr_type;
80 };
81
82 struct omap_mbox {
83 const char *name;
84 int irq;
85 struct omap_mbox_device *parent;
86 struct omap_mbox_fifo tx_fifo;
87 struct omap_mbox_fifo rx_fifo;
88 u32 intr_type;
89 struct mbox_chan *chan;
90 bool send_no_irq;
91 };
92
93 static inline
mbox_read_reg(struct omap_mbox_device * mdev,size_t ofs)94 unsigned int mbox_read_reg(struct omap_mbox_device *mdev, size_t ofs)
95 {
96 return __raw_readl(mdev->mbox_base + ofs);
97 }
98
99 static inline
mbox_write_reg(struct omap_mbox_device * mdev,u32 val,size_t ofs)100 void mbox_write_reg(struct omap_mbox_device *mdev, u32 val, size_t ofs)
101 {
102 __raw_writel(val, mdev->mbox_base + ofs);
103 }
104
105 /* Mailbox FIFO handle functions */
mbox_fifo_read(struct omap_mbox * mbox)106 static u32 mbox_fifo_read(struct omap_mbox *mbox)
107 {
108 struct omap_mbox_fifo *fifo = &mbox->rx_fifo;
109
110 return mbox_read_reg(mbox->parent, fifo->msg);
111 }
112
mbox_fifo_write(struct omap_mbox * mbox,u32 msg)113 static void mbox_fifo_write(struct omap_mbox *mbox, u32 msg)
114 {
115 struct omap_mbox_fifo *fifo = &mbox->tx_fifo;
116
117 mbox_write_reg(mbox->parent, msg, fifo->msg);
118 }
119
mbox_fifo_empty(struct omap_mbox * mbox)120 static int mbox_fifo_empty(struct omap_mbox *mbox)
121 {
122 struct omap_mbox_fifo *fifo = &mbox->rx_fifo;
123
124 return (mbox_read_reg(mbox->parent, fifo->msg_stat) == 0);
125 }
126
mbox_fifo_full(struct omap_mbox * mbox)127 static int mbox_fifo_full(struct omap_mbox *mbox)
128 {
129 struct omap_mbox_fifo *fifo = &mbox->tx_fifo;
130
131 return mbox_read_reg(mbox->parent, fifo->fifo_stat);
132 }
133
134 /* Mailbox IRQ handle functions */
ack_mbox_irq(struct omap_mbox * mbox,omap_mbox_irq_t irq)135 static void ack_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
136 {
137 struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
138 &mbox->tx_fifo : &mbox->rx_fifo;
139 u32 bit = fifo->intr_bit;
140 u32 irqstatus = fifo->irqstatus;
141
142 mbox_write_reg(mbox->parent, bit, irqstatus);
143
144 /* Flush posted write for irq status to avoid spurious interrupts */
145 mbox_read_reg(mbox->parent, irqstatus);
146 }
147
is_mbox_irq(struct omap_mbox * mbox,omap_mbox_irq_t irq)148 static int is_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
149 {
150 struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
151 &mbox->tx_fifo : &mbox->rx_fifo;
152 u32 bit = fifo->intr_bit;
153 u32 irqenable = fifo->irqenable;
154 u32 irqstatus = fifo->irqstatus;
155
156 u32 enable = mbox_read_reg(mbox->parent, irqenable);
157 u32 status = mbox_read_reg(mbox->parent, irqstatus);
158
159 return (int)(enable & status & bit);
160 }
161
omap_mbox_enable_irq(struct omap_mbox * mbox,omap_mbox_irq_t irq)162 static void omap_mbox_enable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
163 {
164 u32 l;
165 struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
166 &mbox->tx_fifo : &mbox->rx_fifo;
167 u32 bit = fifo->intr_bit;
168 u32 irqenable = fifo->irqenable;
169
170 l = mbox_read_reg(mbox->parent, irqenable);
171 l |= bit;
172 mbox_write_reg(mbox->parent, l, irqenable);
173 }
174
omap_mbox_disable_irq(struct omap_mbox * mbox,omap_mbox_irq_t irq)175 static void omap_mbox_disable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
176 {
177 struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
178 &mbox->tx_fifo : &mbox->rx_fifo;
179 u32 bit = fifo->intr_bit;
180 u32 irqdisable = fifo->irqdisable;
181
182 /*
183 * Read and update the interrupt configuration register for pre-OMAP4.
184 * OMAP4 and later SoCs have a dedicated interrupt disabling register.
185 */
186 if (!mbox->intr_type)
187 bit = mbox_read_reg(mbox->parent, irqdisable) & ~bit;
188
189 mbox_write_reg(mbox->parent, bit, irqdisable);
190 }
191
192 /*
193 * Mailbox interrupt handler
194 */
__mbox_tx_interrupt(struct omap_mbox * mbox)195 static void __mbox_tx_interrupt(struct omap_mbox *mbox)
196 {
197 omap_mbox_disable_irq(mbox, IRQ_TX);
198 ack_mbox_irq(mbox, IRQ_TX);
199 mbox_chan_txdone(mbox->chan, 0);
200 }
201
__mbox_rx_interrupt(struct omap_mbox * mbox)202 static void __mbox_rx_interrupt(struct omap_mbox *mbox)
203 {
204 u32 msg;
205
206 while (!mbox_fifo_empty(mbox)) {
207 msg = mbox_fifo_read(mbox);
208 mbox_chan_received_data(mbox->chan, (void *)(uintptr_t)msg);
209 }
210
211 /* clear IRQ source. */
212 ack_mbox_irq(mbox, IRQ_RX);
213 }
214
mbox_interrupt(int irq,void * p)215 static irqreturn_t mbox_interrupt(int irq, void *p)
216 {
217 struct omap_mbox *mbox = p;
218
219 if (is_mbox_irq(mbox, IRQ_TX))
220 __mbox_tx_interrupt(mbox);
221
222 if (is_mbox_irq(mbox, IRQ_RX))
223 __mbox_rx_interrupt(mbox);
224
225 return IRQ_HANDLED;
226 }
227
omap_mbox_startup(struct omap_mbox * mbox)228 static int omap_mbox_startup(struct omap_mbox *mbox)
229 {
230 int ret = 0;
231
232 ret = request_threaded_irq(mbox->irq, NULL, mbox_interrupt,
233 IRQF_SHARED | IRQF_ONESHOT, mbox->name,
234 mbox);
235 if (unlikely(ret)) {
236 pr_err("failed to register mailbox interrupt:%d\n", ret);
237 return ret;
238 }
239
240 if (mbox->send_no_irq)
241 mbox->chan->txdone_method = TXDONE_BY_ACK;
242
243 omap_mbox_enable_irq(mbox, IRQ_RX);
244
245 return 0;
246 }
247
omap_mbox_fini(struct omap_mbox * mbox)248 static void omap_mbox_fini(struct omap_mbox *mbox)
249 {
250 omap_mbox_disable_irq(mbox, IRQ_RX);
251 free_irq(mbox->irq, mbox);
252 }
253
omap_mbox_chan_startup(struct mbox_chan * chan)254 static int omap_mbox_chan_startup(struct mbox_chan *chan)
255 {
256 struct omap_mbox *mbox = chan->con_priv;
257 struct omap_mbox_device *mdev = mbox->parent;
258 int ret = 0;
259
260 mutex_lock(&mdev->cfg_lock);
261 pm_runtime_get_sync(mdev->dev);
262 ret = omap_mbox_startup(mbox);
263 if (ret)
264 pm_runtime_put_sync(mdev->dev);
265 mutex_unlock(&mdev->cfg_lock);
266 return ret;
267 }
268
omap_mbox_chan_shutdown(struct mbox_chan * chan)269 static void omap_mbox_chan_shutdown(struct mbox_chan *chan)
270 {
271 struct omap_mbox *mbox = chan->con_priv;
272 struct omap_mbox_device *mdev = mbox->parent;
273
274 mutex_lock(&mdev->cfg_lock);
275 omap_mbox_fini(mbox);
276 pm_runtime_put_sync(mdev->dev);
277 mutex_unlock(&mdev->cfg_lock);
278 }
279
omap_mbox_chan_send_noirq(struct omap_mbox * mbox,u32 msg)280 static int omap_mbox_chan_send_noirq(struct omap_mbox *mbox, u32 msg)
281 {
282 if (mbox_fifo_full(mbox))
283 return -EBUSY;
284
285 omap_mbox_enable_irq(mbox, IRQ_RX);
286 mbox_fifo_write(mbox, msg);
287 omap_mbox_disable_irq(mbox, IRQ_RX);
288
289 /* we must read and ack the interrupt directly from here */
290 mbox_fifo_read(mbox);
291 ack_mbox_irq(mbox, IRQ_RX);
292
293 return 0;
294 }
295
omap_mbox_chan_send(struct omap_mbox * mbox,u32 msg)296 static int omap_mbox_chan_send(struct omap_mbox *mbox, u32 msg)
297 {
298 if (mbox_fifo_full(mbox)) {
299 /* always enable the interrupt */
300 omap_mbox_enable_irq(mbox, IRQ_TX);
301 return -EBUSY;
302 }
303
304 mbox_fifo_write(mbox, msg);
305
306 /* always enable the interrupt */
307 omap_mbox_enable_irq(mbox, IRQ_TX);
308 return 0;
309 }
310
omap_mbox_chan_send_data(struct mbox_chan * chan,void * data)311 static int omap_mbox_chan_send_data(struct mbox_chan *chan, void *data)
312 {
313 struct omap_mbox *mbox = chan->con_priv;
314 int ret;
315 u32 msg = (u32)(uintptr_t)(data);
316
317 if (!mbox)
318 return -EINVAL;
319
320 if (mbox->send_no_irq)
321 ret = omap_mbox_chan_send_noirq(mbox, msg);
322 else
323 ret = omap_mbox_chan_send(mbox, msg);
324
325 return ret;
326 }
327
328 static const struct mbox_chan_ops omap_mbox_chan_ops = {
329 .startup = omap_mbox_chan_startup,
330 .send_data = omap_mbox_chan_send_data,
331 .shutdown = omap_mbox_chan_shutdown,
332 };
333
334 #ifdef CONFIG_PM_SLEEP
omap_mbox_suspend(struct device * dev)335 static int omap_mbox_suspend(struct device *dev)
336 {
337 struct omap_mbox_device *mdev = dev_get_drvdata(dev);
338 u32 usr, fifo, reg;
339
340 if (pm_runtime_status_suspended(dev))
341 return 0;
342
343 for (fifo = 0; fifo < mdev->num_fifos; fifo++) {
344 if (mbox_read_reg(mdev, MAILBOX_MSGSTATUS(fifo))) {
345 dev_err(mdev->dev, "fifo %d has unexpected unread messages\n",
346 fifo);
347 return -EBUSY;
348 }
349 }
350
351 for (usr = 0; usr < mdev->num_users; usr++) {
352 reg = MAILBOX_IRQENABLE(mdev->intr_type, usr);
353 mdev->irq_ctx[usr] = mbox_read_reg(mdev, reg);
354 }
355
356 return 0;
357 }
358
omap_mbox_resume(struct device * dev)359 static int omap_mbox_resume(struct device *dev)
360 {
361 struct omap_mbox_device *mdev = dev_get_drvdata(dev);
362 u32 usr, reg;
363
364 if (pm_runtime_status_suspended(dev))
365 return 0;
366
367 for (usr = 0; usr < mdev->num_users; usr++) {
368 reg = MAILBOX_IRQENABLE(mdev->intr_type, usr);
369 mbox_write_reg(mdev, mdev->irq_ctx[usr], reg);
370 }
371
372 return 0;
373 }
374 #endif
375
376 static const struct dev_pm_ops omap_mbox_pm_ops = {
377 SET_SYSTEM_SLEEP_PM_OPS(omap_mbox_suspend, omap_mbox_resume)
378 };
379
380 static const struct omap_mbox_match_data omap2_data = { MBOX_INTR_CFG_TYPE1 };
381 static const struct omap_mbox_match_data omap4_data = { MBOX_INTR_CFG_TYPE2 };
382
383 static const struct of_device_id omap_mailbox_of_match[] = {
384 {
385 .compatible = "ti,omap2-mailbox",
386 .data = &omap2_data,
387 },
388 {
389 .compatible = "ti,omap3-mailbox",
390 .data = &omap2_data,
391 },
392 {
393 .compatible = "ti,omap4-mailbox",
394 .data = &omap4_data,
395 },
396 {
397 .compatible = "ti,am654-mailbox",
398 .data = &omap4_data,
399 },
400 {
401 .compatible = "ti,am64-mailbox",
402 .data = &omap4_data,
403 },
404 {
405 /* end */
406 },
407 };
408 MODULE_DEVICE_TABLE(of, omap_mailbox_of_match);
409
omap_mbox_of_xlate(struct mbox_controller * controller,const struct of_phandle_args * sp)410 static struct mbox_chan *omap_mbox_of_xlate(struct mbox_controller *controller,
411 const struct of_phandle_args *sp)
412 {
413 phandle phandle = sp->args[0];
414 struct device_node *node;
415 struct omap_mbox_device *mdev;
416 struct omap_mbox *mbox;
417 int i;
418
419 mdev = dev_get_drvdata(controller->dev);
420 if (WARN_ON(!mdev))
421 return ERR_PTR(-EINVAL);
422
423 node = of_find_node_by_phandle(phandle);
424 if (!node) {
425 pr_err("%s: could not find node phandle 0x%x\n",
426 __func__, phandle);
427 return ERR_PTR(-ENODEV);
428 }
429
430 for (i = 0; i < controller->num_chans; i++) {
431 mbox = controller->chans[i].con_priv;
432 if (!strcmp(mbox->name, node->name)) {
433 of_node_put(node);
434 return &controller->chans[i];
435 }
436 }
437
438 of_node_put(node);
439 return ERR_PTR(-ENOENT);
440 }
441
omap_mbox_probe(struct platform_device * pdev)442 static int omap_mbox_probe(struct platform_device *pdev)
443 {
444 int ret;
445 struct mbox_chan *chnls;
446 struct omap_mbox *mbox;
447 struct omap_mbox_device *mdev;
448 struct omap_mbox_fifo *fifo;
449 struct device_node *node = pdev->dev.of_node;
450 struct device_node *child;
451 const struct omap_mbox_match_data *match_data;
452 struct mbox_controller *controller;
453 u32 intr_type, info_count;
454 u32 num_users, num_fifos;
455 u32 tmp[3];
456 u32 l;
457 int i;
458
459 if (!node) {
460 pr_err("%s: only DT-based devices are supported\n", __func__);
461 return -ENODEV;
462 }
463
464 match_data = of_device_get_match_data(&pdev->dev);
465 if (!match_data)
466 return -ENODEV;
467 intr_type = match_data->intr_type;
468
469 if (of_property_read_u32(node, "ti,mbox-num-users", &num_users))
470 return -ENODEV;
471
472 if (of_property_read_u32(node, "ti,mbox-num-fifos", &num_fifos))
473 return -ENODEV;
474
475 info_count = of_get_available_child_count(node);
476 if (!info_count) {
477 dev_err(&pdev->dev, "no available mbox devices found\n");
478 return -ENODEV;
479 }
480
481 mdev = devm_kzalloc(&pdev->dev, sizeof(*mdev), GFP_KERNEL);
482 if (!mdev)
483 return -ENOMEM;
484
485 mdev->mbox_base = devm_platform_ioremap_resource(pdev, 0);
486 if (IS_ERR(mdev->mbox_base))
487 return PTR_ERR(mdev->mbox_base);
488
489 mdev->irq_ctx = devm_kcalloc(&pdev->dev, num_users, sizeof(u32),
490 GFP_KERNEL);
491 if (!mdev->irq_ctx)
492 return -ENOMEM;
493
494 chnls = devm_kcalloc(&pdev->dev, info_count + 1, sizeof(*chnls),
495 GFP_KERNEL);
496 if (!chnls)
497 return -ENOMEM;
498
499 child = NULL;
500 for (i = 0; i < info_count; i++) {
501 int tx_id, tx_irq, tx_usr;
502 int rx_id, rx_usr;
503
504 mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL);
505 if (!mbox)
506 return -ENOMEM;
507
508 child = of_get_next_available_child(node, child);
509 ret = of_property_read_u32_array(child, "ti,mbox-tx", tmp,
510 ARRAY_SIZE(tmp));
511 if (ret)
512 return ret;
513 tx_id = tmp[0];
514 tx_irq = tmp[1];
515 tx_usr = tmp[2];
516
517 ret = of_property_read_u32_array(child, "ti,mbox-rx", tmp,
518 ARRAY_SIZE(tmp));
519 if (ret)
520 return ret;
521 rx_id = tmp[0];
522 /* rx_irq = tmp[1]; */
523 rx_usr = tmp[2];
524
525 if (tx_id >= num_fifos || rx_id >= num_fifos ||
526 tx_usr >= num_users || rx_usr >= num_users)
527 return -EINVAL;
528
529 fifo = &mbox->tx_fifo;
530 fifo->msg = MAILBOX_MESSAGE(tx_id);
531 fifo->fifo_stat = MAILBOX_FIFOSTATUS(tx_id);
532 fifo->intr_bit = MAILBOX_IRQ_NOTFULL(tx_id);
533 fifo->irqenable = MAILBOX_IRQENABLE(intr_type, tx_usr);
534 fifo->irqstatus = MAILBOX_IRQSTATUS(intr_type, tx_usr);
535 fifo->irqdisable = MAILBOX_IRQDISABLE(intr_type, tx_usr);
536
537 fifo = &mbox->rx_fifo;
538 fifo->msg = MAILBOX_MESSAGE(rx_id);
539 fifo->msg_stat = MAILBOX_MSGSTATUS(rx_id);
540 fifo->intr_bit = MAILBOX_IRQ_NEWMSG(rx_id);
541 fifo->irqenable = MAILBOX_IRQENABLE(intr_type, rx_usr);
542 fifo->irqstatus = MAILBOX_IRQSTATUS(intr_type, rx_usr);
543 fifo->irqdisable = MAILBOX_IRQDISABLE(intr_type, rx_usr);
544
545 mbox->send_no_irq = of_property_read_bool(child, "ti,mbox-send-noirq");
546 mbox->intr_type = intr_type;
547
548 mbox->parent = mdev;
549 mbox->name = child->name;
550 mbox->irq = platform_get_irq(pdev, tx_irq);
551 if (mbox->irq < 0)
552 return mbox->irq;
553 mbox->chan = &chnls[i];
554 chnls[i].con_priv = mbox;
555 }
556
557 mutex_init(&mdev->cfg_lock);
558 mdev->dev = &pdev->dev;
559 mdev->num_users = num_users;
560 mdev->num_fifos = num_fifos;
561 mdev->intr_type = intr_type;
562
563 controller = devm_kzalloc(&pdev->dev, sizeof(*controller), GFP_KERNEL);
564 if (!controller)
565 return -ENOMEM;
566 /*
567 * OMAP/K3 Mailbox IP does not have a Tx-Done IRQ, but rather a Tx-Ready
568 * IRQ and is needed to run the Tx state machine
569 */
570 controller->txdone_irq = true;
571 controller->dev = mdev->dev;
572 controller->ops = &omap_mbox_chan_ops;
573 controller->chans = chnls;
574 controller->num_chans = info_count;
575 controller->of_xlate = omap_mbox_of_xlate;
576 ret = devm_mbox_controller_register(mdev->dev, controller);
577 if (ret)
578 return ret;
579
580 platform_set_drvdata(pdev, mdev);
581 devm_pm_runtime_enable(mdev->dev);
582
583 ret = pm_runtime_resume_and_get(mdev->dev);
584 if (ret < 0)
585 return ret;
586
587 /*
588 * just print the raw revision register, the format is not
589 * uniform across all SoCs
590 */
591 l = mbox_read_reg(mdev, MAILBOX_REVISION);
592 dev_info(mdev->dev, "omap mailbox rev 0x%x\n", l);
593
594 ret = pm_runtime_put_sync(mdev->dev);
595 if (ret < 0 && ret != -ENOSYS)
596 return ret;
597
598 return 0;
599 }
600
601 static struct platform_driver omap_mbox_driver = {
602 .probe = omap_mbox_probe,
603 .driver = {
604 .name = "omap-mailbox",
605 .pm = &omap_mbox_pm_ops,
606 .of_match_table = omap_mailbox_of_match,
607 },
608 };
609 module_platform_driver(omap_mbox_driver);
610
611 MODULE_LICENSE("GPL v2");
612 MODULE_DESCRIPTION("omap mailbox: interrupt driven messaging");
613 MODULE_AUTHOR("Toshihiro Kobayashi");
614 MODULE_AUTHOR("Hiroshi DOYU");
615