Linux Audio

Check our new training course

Linux kernel drivers training

Mar 31-Apr 9, 2025, special US time zones
Register
Loading...
Note: File does not exist in v3.5.6.
  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
 47static bool qmp_cdev_max_state = 1;
 48
 49struct 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 */
 69struct 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
 87static 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
 93static bool qmp_magic_valid(struct qmp *qmp)
 94{
 95	return readl(qmp->msgram + QMP_DESC_MAGIC) == QMP_MAGIC;
 96}
 97
 98static bool qmp_link_acked(struct qmp *qmp)
 99{
100	return readl(qmp->msgram + QMP_DESC_MCORE_LINK_STATE_ACK) == QMP_STATE_UP;
101}
102
103static 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
108static bool qmp_ucore_channel_up(struct qmp *qmp)
109{
110	return readl(qmp->msgram + QMP_DESC_UCORE_CH_STATE) == QMP_STATE_UP;
111}
112
113static 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
174timeout_close_channel:
175	writel(QMP_STATE_DOWN, qmp->msgram + QMP_DESC_MCORE_CH_STATE);
176
177timeout_close_link:
178	writel(QMP_STATE_DOWN, qmp->msgram + QMP_DESC_MCORE_LINK_STATE);
179	qmp_kick(qmp);
180
181	return -ETIMEDOUT;
182}
183
184static 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
191static 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
200static 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 * @data: message to be sent
209 * @len: length of the message
210 *
211 * Transmit @data to AOSS and wait for the AOSS to acknowledge the message.
212 * @len must be a multiple of 4 and not longer than the mailbox size. Access is
213 * synchronized by this implementation.
214 *
215 * Return: 0 on success, negative errno on failure
216 */
217int qmp_send(struct qmp *qmp, const void *data, size_t len)
218{
219	long time_left;
220	int ret;
221
222	if (WARN_ON(IS_ERR_OR_NULL(qmp) || !data))
223		return -EINVAL;
224
225	if (WARN_ON(len + sizeof(u32) > qmp->size))
226		return -EINVAL;
227
228	if (WARN_ON(len % sizeof(u32)))
229		return -EINVAL;
230
231	mutex_lock(&qmp->tx_lock);
232
233	/* The message RAM only implements 32-bit accesses */
234	__iowrite32_copy(qmp->msgram + qmp->offset + sizeof(u32),
235			 data, len / sizeof(u32));
236	writel(len, qmp->msgram + qmp->offset);
237
238	/* Read back len to confirm data written in message RAM */
239	readl(qmp->msgram + qmp->offset);
240	qmp_kick(qmp);
241
242	time_left = wait_event_interruptible_timeout(qmp->event,
243						     qmp_message_empty(qmp), HZ);
244	if (!time_left) {
245		dev_err(qmp->dev, "ucore did not ack channel\n");
246		ret = -ETIMEDOUT;
247
248		/* Clear message from buffer */
249		writel(0, qmp->msgram + qmp->offset);
250	} else {
251		ret = 0;
252	}
253
254	mutex_unlock(&qmp->tx_lock);
255
256	return ret;
257}
258EXPORT_SYMBOL(qmp_send);
259
260static int qmp_qdss_clk_prepare(struct clk_hw *hw)
261{
262	static const char buf[QMP_MSG_LEN] = "{class: clock, res: qdss, val: 1}";
263	struct qmp *qmp = container_of(hw, struct qmp, qdss_clk);
264
265	return qmp_send(qmp, buf, sizeof(buf));
266}
267
268static void qmp_qdss_clk_unprepare(struct clk_hw *hw)
269{
270	static const char buf[QMP_MSG_LEN] = "{class: clock, res: qdss, val: 0}";
271	struct qmp *qmp = container_of(hw, struct qmp, qdss_clk);
272
273	qmp_send(qmp, buf, sizeof(buf));
274}
275
276static const struct clk_ops qmp_qdss_clk_ops = {
277	.prepare = qmp_qdss_clk_prepare,
278	.unprepare = qmp_qdss_clk_unprepare,
279};
280
281static int qmp_qdss_clk_add(struct qmp *qmp)
282{
283	static const struct clk_init_data qdss_init = {
284		.ops = &qmp_qdss_clk_ops,
285		.name = "qdss",
286	};
287	int ret;
288
289	qmp->qdss_clk.init = &qdss_init;
290	ret = clk_hw_register(qmp->dev, &qmp->qdss_clk);
291	if (ret < 0) {
292		dev_err(qmp->dev, "failed to register qdss clock\n");
293		return ret;
294	}
295
296	ret = of_clk_add_hw_provider(qmp->dev->of_node, of_clk_hw_simple_get,
297				     &qmp->qdss_clk);
298	if (ret < 0) {
299		dev_err(qmp->dev, "unable to register of clk hw provider\n");
300		clk_hw_unregister(&qmp->qdss_clk);
301	}
302
303	return ret;
304}
305
306static void qmp_qdss_clk_remove(struct qmp *qmp)
307{
308	of_clk_del_provider(qmp->dev->of_node);
309	clk_hw_unregister(&qmp->qdss_clk);
310}
311
312static int qmp_cdev_get_max_state(struct thermal_cooling_device *cdev,
313				  unsigned long *state)
314{
315	*state = qmp_cdev_max_state;
316	return 0;
317}
318
319static int qmp_cdev_get_cur_state(struct thermal_cooling_device *cdev,
320				  unsigned long *state)
321{
322	struct qmp_cooling_device *qmp_cdev = cdev->devdata;
323
324	*state = qmp_cdev->state;
325	return 0;
326}
327
328static int qmp_cdev_set_cur_state(struct thermal_cooling_device *cdev,
329				  unsigned long state)
330{
331	struct qmp_cooling_device *qmp_cdev = cdev->devdata;
332	char buf[QMP_MSG_LEN] = {};
333	bool cdev_state;
334	int ret;
335
336	/* Normalize state */
337	cdev_state = !!state;
338
339	if (qmp_cdev->state == state)
340		return 0;
341
342	snprintf(buf, sizeof(buf),
343		 "{class: volt_flr, event:zero_temp, res:%s, value:%s}",
344			qmp_cdev->name,
345			cdev_state ? "on" : "off");
346
347	ret = qmp_send(qmp_cdev->qmp, buf, sizeof(buf));
348
349	if (!ret)
350		qmp_cdev->state = cdev_state;
351
352	return ret;
353}
354
355static const struct thermal_cooling_device_ops qmp_cooling_device_ops = {
356	.get_max_state = qmp_cdev_get_max_state,
357	.get_cur_state = qmp_cdev_get_cur_state,
358	.set_cur_state = qmp_cdev_set_cur_state,
359};
360
361static int qmp_cooling_device_add(struct qmp *qmp,
362				  struct qmp_cooling_device *qmp_cdev,
363				  struct device_node *node)
364{
365	char *cdev_name = (char *)node->name;
366
367	qmp_cdev->qmp = qmp;
368	qmp_cdev->state = !qmp_cdev_max_state;
369	qmp_cdev->name = cdev_name;
370	qmp_cdev->cdev = devm_thermal_of_cooling_device_register
371				(qmp->dev, node,
372				cdev_name,
373				qmp_cdev, &qmp_cooling_device_ops);
374
375	if (IS_ERR(qmp_cdev->cdev))
376		dev_err(qmp->dev, "unable to register %s cooling device\n",
377			cdev_name);
378
379	return PTR_ERR_OR_ZERO(qmp_cdev->cdev);
380}
381
382static int qmp_cooling_devices_register(struct qmp *qmp)
383{
384	struct device_node *np, *child;
385	int count = 0;
386	int ret;
387
388	np = qmp->dev->of_node;
389
390	qmp->cooling_devs = devm_kcalloc(qmp->dev, QMP_NUM_COOLING_RESOURCES,
391					 sizeof(*qmp->cooling_devs),
392					 GFP_KERNEL);
393
394	if (!qmp->cooling_devs)
395		return -ENOMEM;
396
397	for_each_available_child_of_node(np, child) {
398		if (!of_find_property(child, "#cooling-cells", NULL))
399			continue;
400		ret = qmp_cooling_device_add(qmp, &qmp->cooling_devs[count++],
401					     child);
402		if (ret) {
403			of_node_put(child);
404			goto unroll;
405		}
406	}
407
408	if (!count)
409		devm_kfree(qmp->dev, qmp->cooling_devs);
410
411	return 0;
412
413unroll:
414	while (--count >= 0)
415		thermal_cooling_device_unregister
416			(qmp->cooling_devs[count].cdev);
417	devm_kfree(qmp->dev, qmp->cooling_devs);
418
419	return ret;
420}
421
422static void qmp_cooling_devices_remove(struct qmp *qmp)
423{
424	int i;
425
426	for (i = 0; i < QMP_NUM_COOLING_RESOURCES; i++)
427		thermal_cooling_device_unregister(qmp->cooling_devs[i].cdev);
428}
429
430/**
431 * qmp_get() - get a qmp handle from a device
432 * @dev: client device pointer
433 *
434 * Return: handle to qmp device on success, ERR_PTR() on failure
435 */
436struct qmp *qmp_get(struct device *dev)
437{
438	struct platform_device *pdev;
439	struct device_node *np;
440	struct qmp *qmp;
441
442	if (!dev || !dev->of_node)
443		return ERR_PTR(-EINVAL);
444
445	np = of_parse_phandle(dev->of_node, "qcom,qmp", 0);
446	if (!np)
447		return ERR_PTR(-ENODEV);
448
449	pdev = of_find_device_by_node(np);
450	of_node_put(np);
451	if (!pdev)
452		return ERR_PTR(-EINVAL);
453
454	qmp = platform_get_drvdata(pdev);
455
456	if (!qmp) {
457		put_device(&pdev->dev);
458		return ERR_PTR(-EPROBE_DEFER);
459	}
460	return qmp;
461}
462EXPORT_SYMBOL(qmp_get);
463
464/**
465 * qmp_put() - release a qmp handle
466 * @qmp: qmp handle obtained from qmp_get()
467 */
468void qmp_put(struct qmp *qmp)
469{
470	/*
471	 * Match get_device() inside of_find_device_by_node() in
472	 * qmp_get()
473	 */
474	if (!IS_ERR_OR_NULL(qmp))
475		put_device(qmp->dev);
476}
477EXPORT_SYMBOL(qmp_put);
478
479static int qmp_probe(struct platform_device *pdev)
480{
481	struct qmp *qmp;
482	int irq;
483	int ret;
484
485	qmp = devm_kzalloc(&pdev->dev, sizeof(*qmp), GFP_KERNEL);
486	if (!qmp)
487		return -ENOMEM;
488
489	qmp->dev = &pdev->dev;
490	init_waitqueue_head(&qmp->event);
491	mutex_init(&qmp->tx_lock);
492
493	qmp->msgram = devm_platform_ioremap_resource(pdev, 0);
494	if (IS_ERR(qmp->msgram))
495		return PTR_ERR(qmp->msgram);
496
497	qmp->mbox_client.dev = &pdev->dev;
498	qmp->mbox_client.knows_txdone = true;
499	qmp->mbox_chan = mbox_request_channel(&qmp->mbox_client, 0);
500	if (IS_ERR(qmp->mbox_chan)) {
501		dev_err(&pdev->dev, "failed to acquire ipc mailbox\n");
502		return PTR_ERR(qmp->mbox_chan);
503	}
504
505	irq = platform_get_irq(pdev, 0);
506	ret = devm_request_irq(&pdev->dev, irq, qmp_intr, 0,
507			       "aoss-qmp", qmp);
508	if (ret < 0) {
509		dev_err(&pdev->dev, "failed to request interrupt\n");
510		goto err_free_mbox;
511	}
512
513	ret = qmp_open(qmp);
514	if (ret < 0)
515		goto err_free_mbox;
516
517	ret = qmp_qdss_clk_add(qmp);
518	if (ret)
519		goto err_close_qmp;
520
521	ret = qmp_cooling_devices_register(qmp);
522	if (ret)
523		dev_err(&pdev->dev, "failed to register aoss cooling devices\n");
524
525	platform_set_drvdata(pdev, qmp);
526
527	return 0;
528
529err_close_qmp:
530	qmp_close(qmp);
531err_free_mbox:
532	mbox_free_channel(qmp->mbox_chan);
533
534	return ret;
535}
536
537static int qmp_remove(struct platform_device *pdev)
538{
539	struct qmp *qmp = platform_get_drvdata(pdev);
540
541	qmp_qdss_clk_remove(qmp);
542	qmp_cooling_devices_remove(qmp);
543
544	qmp_close(qmp);
545	mbox_free_channel(qmp->mbox_chan);
546
547	return 0;
548}
549
550static const struct of_device_id qmp_dt_match[] = {
551	{ .compatible = "qcom,sc7180-aoss-qmp", },
552	{ .compatible = "qcom,sc7280-aoss-qmp", },
553	{ .compatible = "qcom,sdm845-aoss-qmp", },
554	{ .compatible = "qcom,sm8150-aoss-qmp", },
555	{ .compatible = "qcom,sm8250-aoss-qmp", },
556	{ .compatible = "qcom,sm8350-aoss-qmp", },
557	{ .compatible = "qcom,aoss-qmp", },
558	{}
559};
560MODULE_DEVICE_TABLE(of, qmp_dt_match);
561
562static struct platform_driver qmp_driver = {
563	.driver = {
564		.name		= "qcom_aoss_qmp",
565		.of_match_table	= qmp_dt_match,
566		.suppress_bind_attrs = true,
567	},
568	.probe = qmp_probe,
569	.remove	= qmp_remove,
570};
571module_platform_driver(qmp_driver);
572
573MODULE_DESCRIPTION("Qualcomm AOSS QMP driver");
574MODULE_LICENSE("GPL v2");