xref: /linux/drivers/soc/qcom/qcom_aoss.c (revision b8e85e6f3a09fc56b0ff574887798962ef8a8f80)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2019, Linaro Ltd
4  */
5 #include <linux/clk-provider.h>
6 #include <linux/interrupt.h>
7 #include <linux/io.h>
8 #include <linux/mailbox_client.h>
9 #include <linux/module.h>
10 #include <linux/of_platform.h>
11 #include <linux/platform_device.h>
12 #include <linux/thermal.h>
13 #include <linux/slab.h>
14 #include <linux/soc/qcom/qcom_aoss.h>
15 
16 #define QMP_DESC_MAGIC			0x0
17 #define QMP_DESC_VERSION		0x4
18 #define QMP_DESC_FEATURES		0x8
19 
20 /* AOP-side offsets */
21 #define QMP_DESC_UCORE_LINK_STATE	0xc
22 #define QMP_DESC_UCORE_LINK_STATE_ACK	0x10
23 #define QMP_DESC_UCORE_CH_STATE		0x14
24 #define QMP_DESC_UCORE_CH_STATE_ACK	0x18
25 #define QMP_DESC_UCORE_MBOX_SIZE	0x1c
26 #define QMP_DESC_UCORE_MBOX_OFFSET	0x20
27 
28 /* Linux-side offsets */
29 #define QMP_DESC_MCORE_LINK_STATE	0x24
30 #define QMP_DESC_MCORE_LINK_STATE_ACK	0x28
31 #define QMP_DESC_MCORE_CH_STATE		0x2c
32 #define QMP_DESC_MCORE_CH_STATE_ACK	0x30
33 #define QMP_DESC_MCORE_MBOX_SIZE	0x34
34 #define QMP_DESC_MCORE_MBOX_OFFSET	0x38
35 
36 #define QMP_STATE_UP			GENMASK(15, 0)
37 #define QMP_STATE_DOWN			GENMASK(31, 16)
38 
39 #define QMP_MAGIC			0x4d41494c /* mail */
40 #define QMP_VERSION			1
41 
42 /* 64 bytes is enough to store the requests and provides padding to 4 bytes */
43 #define QMP_MSG_LEN			64
44 
45 #define QMP_NUM_COOLING_RESOURCES	2
46 
47 static bool qmp_cdev_max_state = 1;
48 
49 struct qmp_cooling_device {
50 	struct thermal_cooling_device *cdev;
51 	struct qmp *qmp;
52 	char *name;
53 	bool state;
54 };
55 
56 /**
57  * struct qmp - driver state for QMP implementation
58  * @msgram: iomem referencing the message RAM used for communication
59  * @dev: reference to QMP device
60  * @mbox_client: mailbox client used to ring the doorbell on transmit
61  * @mbox_chan: mailbox channel used to ring the doorbell on transmit
62  * @offset: offset within @msgram where messages should be written
63  * @size: maximum size of the messages to be transmitted
64  * @event: wait_queue for synchronization with the IRQ
65  * @tx_lock: provides synchronization between multiple callers of qmp_send()
66  * @qdss_clk: QDSS clock hw struct
67  * @cooling_devs: thermal cooling devices
68  */
69 struct qmp {
70 	void __iomem *msgram;
71 	struct device *dev;
72 
73 	struct mbox_client mbox_client;
74 	struct mbox_chan *mbox_chan;
75 
76 	size_t offset;
77 	size_t size;
78 
79 	wait_queue_head_t event;
80 
81 	struct mutex tx_lock;
82 
83 	struct clk_hw qdss_clk;
84 	struct qmp_cooling_device *cooling_devs;
85 };
86 
87 static void qmp_kick(struct qmp *qmp)
88 {
89 	mbox_send_message(qmp->mbox_chan, NULL);
90 	mbox_client_txdone(qmp->mbox_chan, 0);
91 }
92 
93 static bool qmp_magic_valid(struct qmp *qmp)
94 {
95 	return readl(qmp->msgram + QMP_DESC_MAGIC) == QMP_MAGIC;
96 }
97 
98 static bool qmp_link_acked(struct qmp *qmp)
99 {
100 	return readl(qmp->msgram + QMP_DESC_MCORE_LINK_STATE_ACK) == QMP_STATE_UP;
101 }
102 
103 static bool qmp_mcore_channel_acked(struct qmp *qmp)
104 {
105 	return readl(qmp->msgram + QMP_DESC_MCORE_CH_STATE_ACK) == QMP_STATE_UP;
106 }
107 
108 static bool qmp_ucore_channel_up(struct qmp *qmp)
109 {
110 	return readl(qmp->msgram + QMP_DESC_UCORE_CH_STATE) == QMP_STATE_UP;
111 }
112 
113 static int qmp_open(struct qmp *qmp)
114 {
115 	int ret;
116 	u32 val;
117 
118 	if (!qmp_magic_valid(qmp)) {
119 		dev_err(qmp->dev, "QMP magic doesn't match\n");
120 		return -EINVAL;
121 	}
122 
123 	val = readl(qmp->msgram + QMP_DESC_VERSION);
124 	if (val != QMP_VERSION) {
125 		dev_err(qmp->dev, "unsupported QMP version %d\n", val);
126 		return -EINVAL;
127 	}
128 
129 	qmp->offset = readl(qmp->msgram + QMP_DESC_MCORE_MBOX_OFFSET);
130 	qmp->size = readl(qmp->msgram + QMP_DESC_MCORE_MBOX_SIZE);
131 	if (!qmp->size) {
132 		dev_err(qmp->dev, "invalid mailbox size\n");
133 		return -EINVAL;
134 	}
135 
136 	/* Ack remote core's link state */
137 	val = readl(qmp->msgram + QMP_DESC_UCORE_LINK_STATE);
138 	writel(val, qmp->msgram + QMP_DESC_UCORE_LINK_STATE_ACK);
139 
140 	/* Set local core's link state to up */
141 	writel(QMP_STATE_UP, qmp->msgram + QMP_DESC_MCORE_LINK_STATE);
142 
143 	qmp_kick(qmp);
144 
145 	ret = wait_event_timeout(qmp->event, qmp_link_acked(qmp), HZ);
146 	if (!ret) {
147 		dev_err(qmp->dev, "ucore didn't ack link\n");
148 		goto timeout_close_link;
149 	}
150 
151 	writel(QMP_STATE_UP, qmp->msgram + QMP_DESC_MCORE_CH_STATE);
152 
153 	qmp_kick(qmp);
154 
155 	ret = wait_event_timeout(qmp->event, qmp_ucore_channel_up(qmp), HZ);
156 	if (!ret) {
157 		dev_err(qmp->dev, "ucore didn't open channel\n");
158 		goto timeout_close_channel;
159 	}
160 
161 	/* Ack remote core's channel state */
162 	writel(QMP_STATE_UP, qmp->msgram + QMP_DESC_UCORE_CH_STATE_ACK);
163 
164 	qmp_kick(qmp);
165 
166 	ret = wait_event_timeout(qmp->event, qmp_mcore_channel_acked(qmp), HZ);
167 	if (!ret) {
168 		dev_err(qmp->dev, "ucore didn't ack channel\n");
169 		goto timeout_close_channel;
170 	}
171 
172 	return 0;
173 
174 timeout_close_channel:
175 	writel(QMP_STATE_DOWN, qmp->msgram + QMP_DESC_MCORE_CH_STATE);
176 
177 timeout_close_link:
178 	writel(QMP_STATE_DOWN, qmp->msgram + QMP_DESC_MCORE_LINK_STATE);
179 	qmp_kick(qmp);
180 
181 	return -ETIMEDOUT;
182 }
183 
184 static void qmp_close(struct qmp *qmp)
185 {
186 	writel(QMP_STATE_DOWN, qmp->msgram + QMP_DESC_MCORE_CH_STATE);
187 	writel(QMP_STATE_DOWN, qmp->msgram + QMP_DESC_MCORE_LINK_STATE);
188 	qmp_kick(qmp);
189 }
190 
191 static irqreturn_t qmp_intr(int irq, void *data)
192 {
193 	struct qmp *qmp = data;
194 
195 	wake_up_all(&qmp->event);
196 
197 	return IRQ_HANDLED;
198 }
199 
200 static bool qmp_message_empty(struct qmp *qmp)
201 {
202 	return readl(qmp->msgram + qmp->offset) == 0;
203 }
204 
205 /**
206  * qmp_send() - send a message to the AOSS
207  * @qmp: qmp context
208  * @fmt: format string for message to be sent
209  * @...: arguments for the format string
210  *
211  * Transmit message to AOSS and wait for the AOSS to acknowledge the message.
212  * data must not be longer than the mailbox size. Access is synchronized by
213  * this implementation.
214  *
215  * Return: 0 on success, negative errno on failure
216  */
217 int qmp_send(struct qmp *qmp, const char *fmt, ...)
218 {
219 	char buf[QMP_MSG_LEN];
220 	long time_left;
221 	va_list args;
222 	int len;
223 	int ret;
224 
225 	if (WARN_ON(IS_ERR_OR_NULL(qmp) || !fmt))
226 		return -EINVAL;
227 
228 	memset(buf, 0, sizeof(buf));
229 	va_start(args, fmt);
230 	len = vsnprintf(buf, sizeof(buf), fmt, args);
231 	va_end(args);
232 
233 	if (WARN_ON(len >= sizeof(buf)))
234 		return -EINVAL;
235 
236 	mutex_lock(&qmp->tx_lock);
237 
238 	/* The message RAM only implements 32-bit accesses */
239 	__iowrite32_copy(qmp->msgram + qmp->offset + sizeof(u32),
240 			 buf, sizeof(buf) / sizeof(u32));
241 	writel(sizeof(buf), qmp->msgram + qmp->offset);
242 
243 	/* Read back length to confirm data written in message RAM */
244 	readl(qmp->msgram + qmp->offset);
245 	qmp_kick(qmp);
246 
247 	time_left = wait_event_interruptible_timeout(qmp->event,
248 						     qmp_message_empty(qmp), HZ);
249 	if (!time_left) {
250 		dev_err(qmp->dev, "ucore did not ack channel\n");
251 		ret = -ETIMEDOUT;
252 
253 		/* Clear message from buffer */
254 		writel(0, qmp->msgram + qmp->offset);
255 	} else {
256 		ret = 0;
257 	}
258 
259 	mutex_unlock(&qmp->tx_lock);
260 
261 	return ret;
262 }
263 EXPORT_SYMBOL_GPL(qmp_send);
264 
265 static int qmp_qdss_clk_prepare(struct clk_hw *hw)
266 {
267 	static const char *buf = "{class: clock, res: qdss, val: 1}";
268 	struct qmp *qmp = container_of(hw, struct qmp, qdss_clk);
269 
270 	return qmp_send(qmp, buf);
271 }
272 
273 static void qmp_qdss_clk_unprepare(struct clk_hw *hw)
274 {
275 	static const char *buf = "{class: clock, res: qdss, val: 0}";
276 	struct qmp *qmp = container_of(hw, struct qmp, qdss_clk);
277 
278 	qmp_send(qmp, buf);
279 }
280 
281 static const struct clk_ops qmp_qdss_clk_ops = {
282 	.prepare = qmp_qdss_clk_prepare,
283 	.unprepare = qmp_qdss_clk_unprepare,
284 };
285 
286 static int qmp_qdss_clk_add(struct qmp *qmp)
287 {
288 	static const struct clk_init_data qdss_init = {
289 		.ops = &qmp_qdss_clk_ops,
290 		.name = "qdss",
291 	};
292 	int ret;
293 
294 	qmp->qdss_clk.init = &qdss_init;
295 	ret = clk_hw_register(qmp->dev, &qmp->qdss_clk);
296 	if (ret < 0) {
297 		dev_err(qmp->dev, "failed to register qdss clock\n");
298 		return ret;
299 	}
300 
301 	ret = of_clk_add_hw_provider(qmp->dev->of_node, of_clk_hw_simple_get,
302 				     &qmp->qdss_clk);
303 	if (ret < 0) {
304 		dev_err(qmp->dev, "unable to register of clk hw provider\n");
305 		clk_hw_unregister(&qmp->qdss_clk);
306 	}
307 
308 	return ret;
309 }
310 
311 static void qmp_qdss_clk_remove(struct qmp *qmp)
312 {
313 	of_clk_del_provider(qmp->dev->of_node);
314 	clk_hw_unregister(&qmp->qdss_clk);
315 }
316 
317 static int qmp_cdev_get_max_state(struct thermal_cooling_device *cdev,
318 				  unsigned long *state)
319 {
320 	*state = qmp_cdev_max_state;
321 	return 0;
322 }
323 
324 static int qmp_cdev_get_cur_state(struct thermal_cooling_device *cdev,
325 				  unsigned long *state)
326 {
327 	struct qmp_cooling_device *qmp_cdev = cdev->devdata;
328 
329 	*state = qmp_cdev->state;
330 	return 0;
331 }
332 
333 static int qmp_cdev_set_cur_state(struct thermal_cooling_device *cdev,
334 				  unsigned long state)
335 {
336 	struct qmp_cooling_device *qmp_cdev = cdev->devdata;
337 	bool cdev_state;
338 	int ret;
339 
340 	/* Normalize state */
341 	cdev_state = !!state;
342 
343 	if (qmp_cdev->state == state)
344 		return 0;
345 
346 	ret = qmp_send(qmp_cdev->qmp, "{class: volt_flr, event:zero_temp, res:%s, value:%s}",
347 		       qmp_cdev->name, cdev_state ? "on" : "off");
348 	if (!ret)
349 		qmp_cdev->state = cdev_state;
350 
351 	return ret;
352 }
353 
354 static const struct thermal_cooling_device_ops qmp_cooling_device_ops = {
355 	.get_max_state = qmp_cdev_get_max_state,
356 	.get_cur_state = qmp_cdev_get_cur_state,
357 	.set_cur_state = qmp_cdev_set_cur_state,
358 };
359 
360 static int qmp_cooling_device_add(struct qmp *qmp,
361 				  struct qmp_cooling_device *qmp_cdev,
362 				  struct device_node *node)
363 {
364 	char *cdev_name = (char *)node->name;
365 
366 	qmp_cdev->qmp = qmp;
367 	qmp_cdev->state = !qmp_cdev_max_state;
368 	qmp_cdev->name = cdev_name;
369 	qmp_cdev->cdev = devm_thermal_of_cooling_device_register
370 				(qmp->dev, node,
371 				cdev_name,
372 				qmp_cdev, &qmp_cooling_device_ops);
373 
374 	if (IS_ERR(qmp_cdev->cdev))
375 		dev_err(qmp->dev, "unable to register %s cooling device\n",
376 			cdev_name);
377 
378 	return PTR_ERR_OR_ZERO(qmp_cdev->cdev);
379 }
380 
381 static int qmp_cooling_devices_register(struct qmp *qmp)
382 {
383 	struct device_node *np, *child;
384 	int count = 0;
385 	int ret;
386 
387 	np = qmp->dev->of_node;
388 
389 	qmp->cooling_devs = devm_kcalloc(qmp->dev, QMP_NUM_COOLING_RESOURCES,
390 					 sizeof(*qmp->cooling_devs),
391 					 GFP_KERNEL);
392 
393 	if (!qmp->cooling_devs)
394 		return -ENOMEM;
395 
396 	for_each_available_child_of_node(np, child) {
397 		if (!of_property_present(child, "#cooling-cells"))
398 			continue;
399 		ret = qmp_cooling_device_add(qmp, &qmp->cooling_devs[count++],
400 					     child);
401 		if (ret) {
402 			of_node_put(child);
403 			goto unroll;
404 		}
405 	}
406 
407 	if (!count)
408 		devm_kfree(qmp->dev, qmp->cooling_devs);
409 
410 	return 0;
411 
412 unroll:
413 	while (--count >= 0)
414 		thermal_cooling_device_unregister
415 			(qmp->cooling_devs[count].cdev);
416 	devm_kfree(qmp->dev, qmp->cooling_devs);
417 
418 	return ret;
419 }
420 
421 static void qmp_cooling_devices_remove(struct qmp *qmp)
422 {
423 	int i;
424 
425 	for (i = 0; i < QMP_NUM_COOLING_RESOURCES; i++)
426 		thermal_cooling_device_unregister(qmp->cooling_devs[i].cdev);
427 }
428 
429 /**
430  * qmp_get() - get a qmp handle from a device
431  * @dev: client device pointer
432  *
433  * Return: handle to qmp device on success, ERR_PTR() on failure
434  */
435 struct qmp *qmp_get(struct device *dev)
436 {
437 	struct platform_device *pdev;
438 	struct device_node *np;
439 	struct qmp *qmp;
440 
441 	if (!dev || !dev->of_node)
442 		return ERR_PTR(-EINVAL);
443 
444 	np = of_parse_phandle(dev->of_node, "qcom,qmp", 0);
445 	if (!np)
446 		return ERR_PTR(-ENODEV);
447 
448 	pdev = of_find_device_by_node(np);
449 	of_node_put(np);
450 	if (!pdev)
451 		return ERR_PTR(-EINVAL);
452 
453 	qmp = platform_get_drvdata(pdev);
454 
455 	if (!qmp) {
456 		put_device(&pdev->dev);
457 		return ERR_PTR(-EPROBE_DEFER);
458 	}
459 	return qmp;
460 }
461 EXPORT_SYMBOL_GPL(qmp_get);
462 
463 /**
464  * qmp_put() - release a qmp handle
465  * @qmp: qmp handle obtained from qmp_get()
466  */
467 void qmp_put(struct qmp *qmp)
468 {
469 	/*
470 	 * Match get_device() inside of_find_device_by_node() in
471 	 * qmp_get()
472 	 */
473 	if (!IS_ERR_OR_NULL(qmp))
474 		put_device(qmp->dev);
475 }
476 EXPORT_SYMBOL_GPL(qmp_put);
477 
478 static int qmp_probe(struct platform_device *pdev)
479 {
480 	struct qmp *qmp;
481 	int irq;
482 	int ret;
483 
484 	qmp = devm_kzalloc(&pdev->dev, sizeof(*qmp), GFP_KERNEL);
485 	if (!qmp)
486 		return -ENOMEM;
487 
488 	qmp->dev = &pdev->dev;
489 	init_waitqueue_head(&qmp->event);
490 	mutex_init(&qmp->tx_lock);
491 
492 	qmp->msgram = devm_platform_ioremap_resource(pdev, 0);
493 	if (IS_ERR(qmp->msgram))
494 		return PTR_ERR(qmp->msgram);
495 
496 	qmp->mbox_client.dev = &pdev->dev;
497 	qmp->mbox_client.knows_txdone = true;
498 	qmp->mbox_chan = mbox_request_channel(&qmp->mbox_client, 0);
499 	if (IS_ERR(qmp->mbox_chan)) {
500 		dev_err(&pdev->dev, "failed to acquire ipc mailbox\n");
501 		return PTR_ERR(qmp->mbox_chan);
502 	}
503 
504 	irq = platform_get_irq(pdev, 0);
505 	ret = devm_request_irq(&pdev->dev, irq, qmp_intr, 0,
506 			       "aoss-qmp", qmp);
507 	if (ret < 0) {
508 		dev_err(&pdev->dev, "failed to request interrupt\n");
509 		goto err_free_mbox;
510 	}
511 
512 	ret = qmp_open(qmp);
513 	if (ret < 0)
514 		goto err_free_mbox;
515 
516 	ret = qmp_qdss_clk_add(qmp);
517 	if (ret)
518 		goto err_close_qmp;
519 
520 	ret = qmp_cooling_devices_register(qmp);
521 	if (ret)
522 		dev_err(&pdev->dev, "failed to register aoss cooling devices\n");
523 
524 	platform_set_drvdata(pdev, qmp);
525 
526 	return 0;
527 
528 err_close_qmp:
529 	qmp_close(qmp);
530 err_free_mbox:
531 	mbox_free_channel(qmp->mbox_chan);
532 
533 	return ret;
534 }
535 
536 static void qmp_remove(struct platform_device *pdev)
537 {
538 	struct qmp *qmp = platform_get_drvdata(pdev);
539 
540 	qmp_qdss_clk_remove(qmp);
541 	qmp_cooling_devices_remove(qmp);
542 
543 	qmp_close(qmp);
544 	mbox_free_channel(qmp->mbox_chan);
545 }
546 
547 static const struct of_device_id qmp_dt_match[] = {
548 	{ .compatible = "qcom,sc7180-aoss-qmp", },
549 	{ .compatible = "qcom,sc7280-aoss-qmp", },
550 	{ .compatible = "qcom,sdm845-aoss-qmp", },
551 	{ .compatible = "qcom,sm8150-aoss-qmp", },
552 	{ .compatible = "qcom,sm8250-aoss-qmp", },
553 	{ .compatible = "qcom,sm8350-aoss-qmp", },
554 	{ .compatible = "qcom,aoss-qmp", },
555 	{}
556 };
557 MODULE_DEVICE_TABLE(of, qmp_dt_match);
558 
559 static struct platform_driver qmp_driver = {
560 	.driver = {
561 		.name		= "qcom_aoss_qmp",
562 		.of_match_table	= qmp_dt_match,
563 		.suppress_bind_attrs = true,
564 	},
565 	.probe = qmp_probe,
566 	.remove_new = qmp_remove,
567 };
568 module_platform_driver(qmp_driver);
569 
570 MODULE_DESCRIPTION("Qualcomm AOSS QMP driver");
571 MODULE_LICENSE("GPL v2");
572