1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Copyright (c) 2018 MediaTek Inc.
4 
5 #include <linux/bitops.h>
6 #include <linux/clk.h>
7 #include <linux/clk-provider.h>
8 #include <linux/dma-mapping.h>
9 #include <linux/errno.h>
10 #include <linux/interrupt.h>
11 #include <linux/io.h>
12 #include <linux/iopoll.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/platform_device.h>
16 #include <linux/mailbox_controller.h>
17 #include <linux/mailbox/mtk-cmdq-mailbox.h>
18 #include <linux/of_device.h>
19 
20 #define CMDQ_OP_CODE_MASK		(0xff << CMDQ_OP_CODE_SHIFT)
21 #define CMDQ_NUM_CMD(t)			(t->cmd_buf_size / CMDQ_INST_SIZE)
22 
23 #define CMDQ_CURR_IRQ_STATUS		0x10
24 #define CMDQ_SYNC_TOKEN_UPDATE		0x68
25 #define CMDQ_THR_SLOT_CYCLES		0x30
26 #define CMDQ_THR_BASE			0x100
27 #define CMDQ_THR_SIZE			0x80
28 #define CMDQ_THR_WARM_RESET		0x00
29 #define CMDQ_THR_ENABLE_TASK		0x04
30 #define CMDQ_THR_SUSPEND_TASK		0x08
31 #define CMDQ_THR_CURR_STATUS		0x0c
32 #define CMDQ_THR_IRQ_STATUS		0x10
33 #define CMDQ_THR_IRQ_ENABLE		0x14
34 #define CMDQ_THR_CURR_ADDR		0x20
35 #define CMDQ_THR_END_ADDR		0x24
36 #define CMDQ_THR_WAIT_TOKEN		0x30
37 #define CMDQ_THR_PRIORITY		0x40
38 
39 #define CMDQ_THR_ACTIVE_SLOT_CYCLES	0x3200
40 #define CMDQ_THR_ENABLED		0x1
41 #define CMDQ_THR_DISABLED		0x0
42 #define CMDQ_THR_SUSPEND		0x1
43 #define CMDQ_THR_RESUME			0x0
44 #define CMDQ_THR_STATUS_SUSPENDED	BIT(1)
45 #define CMDQ_THR_DO_WARM_RESET		BIT(0)
46 #define CMDQ_THR_IRQ_DONE		0x1
47 #define CMDQ_THR_IRQ_ERROR		0x12
48 #define CMDQ_THR_IRQ_EN			(CMDQ_THR_IRQ_ERROR | CMDQ_THR_IRQ_DONE)
49 #define CMDQ_THR_IS_WAITING		BIT(31)
50 
51 #define CMDQ_JUMP_BY_OFFSET		0x10000000
52 #define CMDQ_JUMP_BY_PA			0x10000001
53 
54 struct cmdq_thread {
55 	struct mbox_chan	*chan;
56 	void __iomem		*base;
57 	struct list_head	task_busy_list;
58 	u32			priority;
59 };
60 
61 struct cmdq_task {
62 	struct cmdq		*cmdq;
63 	struct list_head	list_entry;
64 	dma_addr_t		pa_base;
65 	struct cmdq_thread	*thread;
66 	struct cmdq_pkt		*pkt; /* the packet sent from mailbox client */
67 };
68 
69 struct cmdq {
70 	struct mbox_controller	mbox;
71 	void __iomem		*base;
72 	u32			irq;
73 	u32			thread_nr;
74 	u32			irq_mask;
75 	struct cmdq_thread	*thread;
76 	struct clk		*clock;
77 	bool			suspended;
78 };
79 
80 static int cmdq_thread_suspend(struct cmdq *cmdq, struct cmdq_thread *thread)
81 {
82 	u32 status;
83 
84 	writel(CMDQ_THR_SUSPEND, thread->base + CMDQ_THR_SUSPEND_TASK);
85 
86 	/* If already disabled, treat as suspended successful. */
87 	if (!(readl(thread->base + CMDQ_THR_ENABLE_TASK) & CMDQ_THR_ENABLED))
88 		return 0;
89 
90 	if (readl_poll_timeout_atomic(thread->base + CMDQ_THR_CURR_STATUS,
91 			status, status & CMDQ_THR_STATUS_SUSPENDED, 0, 10)) {
92 		dev_err(cmdq->mbox.dev, "suspend GCE thread 0x%x failed\n",
93 			(u32)(thread->base - cmdq->base));
94 		return -EFAULT;
95 	}
96 
97 	return 0;
98 }
99 
100 static void cmdq_thread_resume(struct cmdq_thread *thread)
101 {
102 	writel(CMDQ_THR_RESUME, thread->base + CMDQ_THR_SUSPEND_TASK);
103 }
104 
105 static void cmdq_init(struct cmdq *cmdq)
106 {
107 	int i;
108 
109 	WARN_ON(clk_enable(cmdq->clock) < 0);
110 	writel(CMDQ_THR_ACTIVE_SLOT_CYCLES, cmdq->base + CMDQ_THR_SLOT_CYCLES);
111 	for (i = 0; i <= CMDQ_MAX_EVENT; i++)
112 		writel(i, cmdq->base + CMDQ_SYNC_TOKEN_UPDATE);
113 	clk_disable(cmdq->clock);
114 }
115 
116 static int cmdq_thread_reset(struct cmdq *cmdq, struct cmdq_thread *thread)
117 {
118 	u32 warm_reset;
119 
120 	writel(CMDQ_THR_DO_WARM_RESET, thread->base + CMDQ_THR_WARM_RESET);
121 	if (readl_poll_timeout_atomic(thread->base + CMDQ_THR_WARM_RESET,
122 			warm_reset, !(warm_reset & CMDQ_THR_DO_WARM_RESET),
123 			0, 10)) {
124 		dev_err(cmdq->mbox.dev, "reset GCE thread 0x%x failed\n",
125 			(u32)(thread->base - cmdq->base));
126 		return -EFAULT;
127 	}
128 
129 	return 0;
130 }
131 
132 static void cmdq_thread_disable(struct cmdq *cmdq, struct cmdq_thread *thread)
133 {
134 	cmdq_thread_reset(cmdq, thread);
135 	writel(CMDQ_THR_DISABLED, thread->base + CMDQ_THR_ENABLE_TASK);
136 }
137 
138 /* notify GCE to re-fetch commands by setting GCE thread PC */
139 static void cmdq_thread_invalidate_fetched_data(struct cmdq_thread *thread)
140 {
141 	writel(readl(thread->base + CMDQ_THR_CURR_ADDR),
142 	       thread->base + CMDQ_THR_CURR_ADDR);
143 }
144 
145 static void cmdq_task_insert_into_thread(struct cmdq_task *task)
146 {
147 	struct device *dev = task->cmdq->mbox.dev;
148 	struct cmdq_thread *thread = task->thread;
149 	struct cmdq_task *prev_task = list_last_entry(
150 			&thread->task_busy_list, typeof(*task), list_entry);
151 	u64 *prev_task_base = prev_task->pkt->va_base;
152 
153 	/* let previous task jump to this task */
154 	dma_sync_single_for_cpu(dev, prev_task->pa_base,
155 				prev_task->pkt->cmd_buf_size, DMA_TO_DEVICE);
156 	prev_task_base[CMDQ_NUM_CMD(prev_task->pkt) - 1] =
157 		(u64)CMDQ_JUMP_BY_PA << 32 | task->pa_base;
158 	dma_sync_single_for_device(dev, prev_task->pa_base,
159 				   prev_task->pkt->cmd_buf_size, DMA_TO_DEVICE);
160 
161 	cmdq_thread_invalidate_fetched_data(thread);
162 }
163 
164 static bool cmdq_thread_is_in_wfe(struct cmdq_thread *thread)
165 {
166 	return readl(thread->base + CMDQ_THR_WAIT_TOKEN) & CMDQ_THR_IS_WAITING;
167 }
168 
169 static void cmdq_task_exec_done(struct cmdq_task *task, enum cmdq_cb_status sta)
170 {
171 	struct cmdq_task_cb *cb = &task->pkt->async_cb;
172 	struct cmdq_cb_data data;
173 
174 	WARN_ON(cb->cb == (cmdq_async_flush_cb)NULL);
175 	data.sta = sta;
176 	data.data = cb->data;
177 	cb->cb(data);
178 
179 	list_del(&task->list_entry);
180 }
181 
182 static void cmdq_task_handle_error(struct cmdq_task *task)
183 {
184 	struct cmdq_thread *thread = task->thread;
185 	struct cmdq_task *next_task;
186 
187 	dev_err(task->cmdq->mbox.dev, "task 0x%p error\n", task);
188 	WARN_ON(cmdq_thread_suspend(task->cmdq, thread) < 0);
189 	next_task = list_first_entry_or_null(&thread->task_busy_list,
190 			struct cmdq_task, list_entry);
191 	if (next_task)
192 		writel(next_task->pa_base, thread->base + CMDQ_THR_CURR_ADDR);
193 	cmdq_thread_resume(thread);
194 }
195 
196 static void cmdq_thread_irq_handler(struct cmdq *cmdq,
197 				    struct cmdq_thread *thread)
198 {
199 	struct cmdq_task *task, *tmp, *curr_task = NULL;
200 	u32 curr_pa, irq_flag, task_end_pa;
201 	bool err;
202 
203 	irq_flag = readl(thread->base + CMDQ_THR_IRQ_STATUS);
204 	writel(~irq_flag, thread->base + CMDQ_THR_IRQ_STATUS);
205 
206 	/*
207 	 * When ISR call this function, another CPU core could run
208 	 * "release task" right before we acquire the spin lock, and thus
209 	 * reset / disable this GCE thread, so we need to check the enable
210 	 * bit of this GCE thread.
211 	 */
212 	if (!(readl(thread->base + CMDQ_THR_ENABLE_TASK) & CMDQ_THR_ENABLED))
213 		return;
214 
215 	if (irq_flag & CMDQ_THR_IRQ_ERROR)
216 		err = true;
217 	else if (irq_flag & CMDQ_THR_IRQ_DONE)
218 		err = false;
219 	else
220 		return;
221 
222 	curr_pa = readl(thread->base + CMDQ_THR_CURR_ADDR);
223 
224 	list_for_each_entry_safe(task, tmp, &thread->task_busy_list,
225 				 list_entry) {
226 		task_end_pa = task->pa_base + task->pkt->cmd_buf_size;
227 		if (curr_pa >= task->pa_base && curr_pa < task_end_pa)
228 			curr_task = task;
229 
230 		if (!curr_task || curr_pa == task_end_pa - CMDQ_INST_SIZE) {
231 			cmdq_task_exec_done(task, CMDQ_CB_NORMAL);
232 			kfree(task);
233 		} else if (err) {
234 			cmdq_task_exec_done(task, CMDQ_CB_ERROR);
235 			cmdq_task_handle_error(curr_task);
236 			kfree(task);
237 		}
238 
239 		if (curr_task)
240 			break;
241 	}
242 
243 	if (list_empty(&thread->task_busy_list)) {
244 		cmdq_thread_disable(cmdq, thread);
245 		clk_disable(cmdq->clock);
246 	}
247 }
248 
249 static irqreturn_t cmdq_irq_handler(int irq, void *dev)
250 {
251 	struct cmdq *cmdq = dev;
252 	unsigned long irq_status, flags = 0L;
253 	int bit;
254 
255 	irq_status = readl(cmdq->base + CMDQ_CURR_IRQ_STATUS) & cmdq->irq_mask;
256 	if (!(irq_status ^ cmdq->irq_mask))
257 		return IRQ_NONE;
258 
259 	for_each_clear_bit(bit, &irq_status, cmdq->thread_nr) {
260 		struct cmdq_thread *thread = &cmdq->thread[bit];
261 
262 		spin_lock_irqsave(&thread->chan->lock, flags);
263 		cmdq_thread_irq_handler(cmdq, thread);
264 		spin_unlock_irqrestore(&thread->chan->lock, flags);
265 	}
266 
267 	return IRQ_HANDLED;
268 }
269 
270 static int cmdq_suspend(struct device *dev)
271 {
272 	struct cmdq *cmdq = dev_get_drvdata(dev);
273 	struct cmdq_thread *thread;
274 	int i;
275 	bool task_running = false;
276 
277 	cmdq->suspended = true;
278 
279 	for (i = 0; i < cmdq->thread_nr; i++) {
280 		thread = &cmdq->thread[i];
281 		if (!list_empty(&thread->task_busy_list)) {
282 			task_running = true;
283 			break;
284 		}
285 	}
286 
287 	if (task_running)
288 		dev_warn(dev, "exist running task(s) in suspend\n");
289 
290 	clk_unprepare(cmdq->clock);
291 
292 	return 0;
293 }
294 
295 static int cmdq_resume(struct device *dev)
296 {
297 	struct cmdq *cmdq = dev_get_drvdata(dev);
298 
299 	WARN_ON(clk_prepare(cmdq->clock) < 0);
300 	cmdq->suspended = false;
301 	return 0;
302 }
303 
304 static int cmdq_remove(struct platform_device *pdev)
305 {
306 	struct cmdq *cmdq = platform_get_drvdata(pdev);
307 
308 	clk_unprepare(cmdq->clock);
309 
310 	return 0;
311 }
312 
313 static int cmdq_mbox_send_data(struct mbox_chan *chan, void *data)
314 {
315 	struct cmdq_pkt *pkt = (struct cmdq_pkt *)data;
316 	struct cmdq_thread *thread = (struct cmdq_thread *)chan->con_priv;
317 	struct cmdq *cmdq = dev_get_drvdata(chan->mbox->dev);
318 	struct cmdq_task *task;
319 	unsigned long curr_pa, end_pa;
320 
321 	/* Client should not flush new tasks if suspended. */
322 	WARN_ON(cmdq->suspended);
323 
324 	task = kzalloc(sizeof(*task), GFP_ATOMIC);
325 	if (!task)
326 		return -ENOMEM;
327 
328 	task->cmdq = cmdq;
329 	INIT_LIST_HEAD(&task->list_entry);
330 	task->pa_base = pkt->pa_base;
331 	task->thread = thread;
332 	task->pkt = pkt;
333 
334 	if (list_empty(&thread->task_busy_list)) {
335 		WARN_ON(clk_enable(cmdq->clock) < 0);
336 		WARN_ON(cmdq_thread_reset(cmdq, thread) < 0);
337 
338 		writel(task->pa_base, thread->base + CMDQ_THR_CURR_ADDR);
339 		writel(task->pa_base + pkt->cmd_buf_size,
340 		       thread->base + CMDQ_THR_END_ADDR);
341 		writel(thread->priority, thread->base + CMDQ_THR_PRIORITY);
342 		writel(CMDQ_THR_IRQ_EN, thread->base + CMDQ_THR_IRQ_ENABLE);
343 		writel(CMDQ_THR_ENABLED, thread->base + CMDQ_THR_ENABLE_TASK);
344 	} else {
345 		WARN_ON(cmdq_thread_suspend(cmdq, thread) < 0);
346 		curr_pa = readl(thread->base + CMDQ_THR_CURR_ADDR);
347 		end_pa = readl(thread->base + CMDQ_THR_END_ADDR);
348 		/* check boundary */
349 		if (curr_pa == end_pa - CMDQ_INST_SIZE ||
350 		    curr_pa == end_pa) {
351 			/* set to this task directly */
352 			writel(task->pa_base,
353 			       thread->base + CMDQ_THR_CURR_ADDR);
354 		} else {
355 			cmdq_task_insert_into_thread(task);
356 			smp_mb(); /* modify jump before enable thread */
357 		}
358 		writel(task->pa_base + pkt->cmd_buf_size,
359 		       thread->base + CMDQ_THR_END_ADDR);
360 		cmdq_thread_resume(thread);
361 	}
362 	list_move_tail(&task->list_entry, &thread->task_busy_list);
363 
364 	return 0;
365 }
366 
367 static int cmdq_mbox_startup(struct mbox_chan *chan)
368 {
369 	return 0;
370 }
371 
372 static void cmdq_mbox_shutdown(struct mbox_chan *chan)
373 {
374 }
375 
376 static int cmdq_mbox_flush(struct mbox_chan *chan, unsigned long timeout)
377 {
378 	struct cmdq_thread *thread = (struct cmdq_thread *)chan->con_priv;
379 	struct cmdq_task_cb *cb;
380 	struct cmdq_cb_data data;
381 	struct cmdq *cmdq = dev_get_drvdata(chan->mbox->dev);
382 	struct cmdq_task *task, *tmp;
383 	unsigned long flags;
384 	u32 enable;
385 
386 	spin_lock_irqsave(&thread->chan->lock, flags);
387 	if (list_empty(&thread->task_busy_list))
388 		goto out;
389 
390 	WARN_ON(cmdq_thread_suspend(cmdq, thread) < 0);
391 	if (!cmdq_thread_is_in_wfe(thread))
392 		goto wait;
393 
394 	list_for_each_entry_safe(task, tmp, &thread->task_busy_list,
395 				 list_entry) {
396 		cb = &task->pkt->async_cb;
397 		if (cb->cb) {
398 			data.sta = CMDQ_CB_ERROR;
399 			data.data = cb->data;
400 			cb->cb(data);
401 		}
402 		list_del(&task->list_entry);
403 		kfree(task);
404 	}
405 
406 	cmdq_thread_resume(thread);
407 	cmdq_thread_disable(cmdq, thread);
408 	clk_disable(cmdq->clock);
409 
410 out:
411 	spin_unlock_irqrestore(&thread->chan->lock, flags);
412 	return 0;
413 
414 wait:
415 	cmdq_thread_resume(thread);
416 	spin_unlock_irqrestore(&thread->chan->lock, flags);
417 	if (readl_poll_timeout_atomic(thread->base + CMDQ_THR_ENABLE_TASK,
418 				      enable, enable == 0, 1, timeout)) {
419 		dev_err(cmdq->mbox.dev, "Fail to wait GCE thread 0x%x done\n",
420 			(u32)(thread->base - cmdq->base));
421 
422 		return -EFAULT;
423 	}
424 	return 0;
425 }
426 
427 static const struct mbox_chan_ops cmdq_mbox_chan_ops = {
428 	.send_data = cmdq_mbox_send_data,
429 	.startup = cmdq_mbox_startup,
430 	.shutdown = cmdq_mbox_shutdown,
431 	.flush = cmdq_mbox_flush,
432 };
433 
434 static struct mbox_chan *cmdq_xlate(struct mbox_controller *mbox,
435 		const struct of_phandle_args *sp)
436 {
437 	int ind = sp->args[0];
438 	struct cmdq_thread *thread;
439 
440 	if (ind >= mbox->num_chans)
441 		return ERR_PTR(-EINVAL);
442 
443 	thread = (struct cmdq_thread *)mbox->chans[ind].con_priv;
444 	thread->priority = sp->args[1];
445 	thread->chan = &mbox->chans[ind];
446 
447 	return &mbox->chans[ind];
448 }
449 
450 static int cmdq_probe(struct platform_device *pdev)
451 {
452 	struct device *dev = &pdev->dev;
453 	struct resource *res;
454 	struct cmdq *cmdq;
455 	int err, i;
456 
457 	cmdq = devm_kzalloc(dev, sizeof(*cmdq), GFP_KERNEL);
458 	if (!cmdq)
459 		return -ENOMEM;
460 
461 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
462 	cmdq->base = devm_ioremap_resource(dev, res);
463 	if (IS_ERR(cmdq->base)) {
464 		dev_err(dev, "failed to ioremap gce\n");
465 		return PTR_ERR(cmdq->base);
466 	}
467 
468 	cmdq->irq = platform_get_irq(pdev, 0);
469 	if (!cmdq->irq) {
470 		dev_err(dev, "failed to get irq\n");
471 		return -EINVAL;
472 	}
473 
474 	cmdq->thread_nr = (u32)(unsigned long)of_device_get_match_data(dev);
475 	cmdq->irq_mask = GENMASK(cmdq->thread_nr - 1, 0);
476 	err = devm_request_irq(dev, cmdq->irq, cmdq_irq_handler, IRQF_SHARED,
477 			       "mtk_cmdq", cmdq);
478 	if (err < 0) {
479 		dev_err(dev, "failed to register ISR (%d)\n", err);
480 		return err;
481 	}
482 
483 	dev_dbg(dev, "cmdq device: addr:0x%p, va:0x%p, irq:%d\n",
484 		dev, cmdq->base, cmdq->irq);
485 
486 	cmdq->clock = devm_clk_get(dev, "gce");
487 	if (IS_ERR(cmdq->clock)) {
488 		dev_err(dev, "failed to get gce clk\n");
489 		return PTR_ERR(cmdq->clock);
490 	}
491 
492 	cmdq->mbox.dev = dev;
493 	cmdq->mbox.chans = devm_kcalloc(dev, cmdq->thread_nr,
494 					sizeof(*cmdq->mbox.chans), GFP_KERNEL);
495 	if (!cmdq->mbox.chans)
496 		return -ENOMEM;
497 
498 	cmdq->mbox.num_chans = cmdq->thread_nr;
499 	cmdq->mbox.ops = &cmdq_mbox_chan_ops;
500 	cmdq->mbox.of_xlate = cmdq_xlate;
501 
502 	/* make use of TXDONE_BY_ACK */
503 	cmdq->mbox.txdone_irq = false;
504 	cmdq->mbox.txdone_poll = false;
505 
506 	cmdq->thread = devm_kcalloc(dev, cmdq->thread_nr,
507 					sizeof(*cmdq->thread), GFP_KERNEL);
508 	if (!cmdq->thread)
509 		return -ENOMEM;
510 
511 	for (i = 0; i < cmdq->thread_nr; i++) {
512 		cmdq->thread[i].base = cmdq->base + CMDQ_THR_BASE +
513 				CMDQ_THR_SIZE * i;
514 		INIT_LIST_HEAD(&cmdq->thread[i].task_busy_list);
515 		cmdq->mbox.chans[i].con_priv = (void *)&cmdq->thread[i];
516 	}
517 
518 	err = devm_mbox_controller_register(dev, &cmdq->mbox);
519 	if (err < 0) {
520 		dev_err(dev, "failed to register mailbox: %d\n", err);
521 		return err;
522 	}
523 
524 	platform_set_drvdata(pdev, cmdq);
525 	WARN_ON(clk_prepare(cmdq->clock) < 0);
526 
527 	cmdq_init(cmdq);
528 
529 	return 0;
530 }
531 
532 static const struct dev_pm_ops cmdq_pm_ops = {
533 	.suspend = cmdq_suspend,
534 	.resume = cmdq_resume,
535 };
536 
537 static const struct of_device_id cmdq_of_ids[] = {
538 	{.compatible = "mediatek,mt8173-gce", .data = (void *)16},
539 	{.compatible = "mediatek,mt8183-gce", .data = (void *)24},
540 	{}
541 };
542 
543 static struct platform_driver cmdq_drv = {
544 	.probe = cmdq_probe,
545 	.remove = cmdq_remove,
546 	.driver = {
547 		.name = "mtk_cmdq",
548 		.pm = &cmdq_pm_ops,
549 		.of_match_table = cmdq_of_ids,
550 	}
551 };
552 
553 static int __init cmdq_drv_init(void)
554 {
555 	return platform_driver_register(&cmdq_drv);
556 }
557 
558 static void __exit cmdq_drv_exit(void)
559 {
560 	platform_driver_unregister(&cmdq_drv);
561 }
562 
563 subsys_initcall(cmdq_drv_init);
564 module_exit(cmdq_drv_exit);
565 
566 MODULE_LICENSE("GPL v2");
567