xref: /openbmc/linux/drivers/dma/qcom/hidma_ll.c (revision b830f94f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Qualcomm Technologies HIDMA DMA engine low level code
4  *
5  * Copyright (c) 2015-2016, The Linux Foundation. All rights reserved.
6  */
7 
8 #include <linux/dmaengine.h>
9 #include <linux/slab.h>
10 #include <linux/interrupt.h>
11 #include <linux/mm.h>
12 #include <linux/highmem.h>
13 #include <linux/dma-mapping.h>
14 #include <linux/delay.h>
15 #include <linux/atomic.h>
16 #include <linux/iopoll.h>
17 #include <linux/kfifo.h>
18 #include <linux/bitops.h>
19 
20 #include "hidma.h"
21 
22 #define HIDMA_EVRE_SIZE			16	/* each EVRE is 16 bytes */
23 
24 #define HIDMA_TRCA_CTRLSTS_REG			0x000
25 #define HIDMA_TRCA_RING_LOW_REG		0x008
26 #define HIDMA_TRCA_RING_HIGH_REG		0x00C
27 #define HIDMA_TRCA_RING_LEN_REG		0x010
28 #define HIDMA_TRCA_DOORBELL_REG		0x400
29 
30 #define HIDMA_EVCA_CTRLSTS_REG			0x000
31 #define HIDMA_EVCA_INTCTRL_REG			0x004
32 #define HIDMA_EVCA_RING_LOW_REG		0x008
33 #define HIDMA_EVCA_RING_HIGH_REG		0x00C
34 #define HIDMA_EVCA_RING_LEN_REG		0x010
35 #define HIDMA_EVCA_WRITE_PTR_REG		0x020
36 #define HIDMA_EVCA_DOORBELL_REG		0x400
37 
38 #define HIDMA_EVCA_IRQ_STAT_REG		0x100
39 #define HIDMA_EVCA_IRQ_CLR_REG			0x108
40 #define HIDMA_EVCA_IRQ_EN_REG			0x110
41 
42 #define HIDMA_EVRE_CFG_IDX			0
43 
44 #define HIDMA_EVRE_ERRINFO_BIT_POS		24
45 #define HIDMA_EVRE_CODE_BIT_POS		28
46 
47 #define HIDMA_EVRE_ERRINFO_MASK		GENMASK(3, 0)
48 #define HIDMA_EVRE_CODE_MASK			GENMASK(3, 0)
49 
50 #define HIDMA_CH_CONTROL_MASK			GENMASK(7, 0)
51 #define HIDMA_CH_STATE_MASK			GENMASK(7, 0)
52 #define HIDMA_CH_STATE_BIT_POS			0x8
53 
54 #define HIDMA_IRQ_EV_CH_EOB_IRQ_BIT_POS	0
55 #define HIDMA_IRQ_EV_CH_WR_RESP_BIT_POS	1
56 #define HIDMA_IRQ_TR_CH_TRE_RD_RSP_ER_BIT_POS	9
57 #define HIDMA_IRQ_TR_CH_DATA_RD_ER_BIT_POS	10
58 #define HIDMA_IRQ_TR_CH_DATA_WR_ER_BIT_POS	11
59 #define HIDMA_IRQ_TR_CH_INVALID_TRE_BIT_POS	14
60 
61 #define ENABLE_IRQS (BIT(HIDMA_IRQ_EV_CH_EOB_IRQ_BIT_POS)	| \
62 		     BIT(HIDMA_IRQ_EV_CH_WR_RESP_BIT_POS)	| \
63 		     BIT(HIDMA_IRQ_TR_CH_TRE_RD_RSP_ER_BIT_POS)	| \
64 		     BIT(HIDMA_IRQ_TR_CH_DATA_RD_ER_BIT_POS)	| \
65 		     BIT(HIDMA_IRQ_TR_CH_DATA_WR_ER_BIT_POS)	| \
66 		     BIT(HIDMA_IRQ_TR_CH_INVALID_TRE_BIT_POS))
67 
68 #define HIDMA_INCREMENT_ITERATOR(iter, size, ring_size)	\
69 do {								\
70 	iter += size;						\
71 	if (iter >= ring_size)					\
72 		iter -= ring_size;				\
73 } while (0)
74 
75 #define HIDMA_CH_STATE(val)	\
76 	((val >> HIDMA_CH_STATE_BIT_POS) & HIDMA_CH_STATE_MASK)
77 
78 #define HIDMA_ERR_INT_MASK				\
79 	(BIT(HIDMA_IRQ_TR_CH_INVALID_TRE_BIT_POS)   |	\
80 	 BIT(HIDMA_IRQ_TR_CH_TRE_RD_RSP_ER_BIT_POS) |	\
81 	 BIT(HIDMA_IRQ_EV_CH_WR_RESP_BIT_POS)	    |	\
82 	 BIT(HIDMA_IRQ_TR_CH_DATA_RD_ER_BIT_POS)    |	\
83 	 BIT(HIDMA_IRQ_TR_CH_DATA_WR_ER_BIT_POS))
84 
85 enum ch_command {
86 	HIDMA_CH_DISABLE = 0,
87 	HIDMA_CH_ENABLE = 1,
88 	HIDMA_CH_SUSPEND = 2,
89 	HIDMA_CH_RESET = 9,
90 };
91 
92 enum ch_state {
93 	HIDMA_CH_DISABLED = 0,
94 	HIDMA_CH_ENABLED = 1,
95 	HIDMA_CH_RUNNING = 2,
96 	HIDMA_CH_SUSPENDED = 3,
97 	HIDMA_CH_STOPPED = 4,
98 };
99 
100 enum err_code {
101 	HIDMA_EVRE_STATUS_COMPLETE = 1,
102 	HIDMA_EVRE_STATUS_ERROR = 4,
103 };
104 
105 static int hidma_is_chan_enabled(int state)
106 {
107 	switch (state) {
108 	case HIDMA_CH_ENABLED:
109 	case HIDMA_CH_RUNNING:
110 		return true;
111 	default:
112 		return false;
113 	}
114 }
115 
116 void hidma_ll_free(struct hidma_lldev *lldev, u32 tre_ch)
117 {
118 	struct hidma_tre *tre;
119 
120 	if (tre_ch >= lldev->nr_tres) {
121 		dev_err(lldev->dev, "invalid TRE number in free:%d", tre_ch);
122 		return;
123 	}
124 
125 	tre = &lldev->trepool[tre_ch];
126 	if (atomic_read(&tre->allocated) != true) {
127 		dev_err(lldev->dev, "trying to free an unused TRE:%d", tre_ch);
128 		return;
129 	}
130 
131 	atomic_set(&tre->allocated, 0);
132 }
133 
134 int hidma_ll_request(struct hidma_lldev *lldev, u32 sig, const char *dev_name,
135 		     void (*callback)(void *data), void *data, u32 *tre_ch)
136 {
137 	unsigned int i;
138 	struct hidma_tre *tre;
139 	u32 *tre_local;
140 
141 	if (!tre_ch || !lldev)
142 		return -EINVAL;
143 
144 	/* need to have at least one empty spot in the queue */
145 	for (i = 0; i < lldev->nr_tres - 1; i++) {
146 		if (atomic_add_unless(&lldev->trepool[i].allocated, 1, 1))
147 			break;
148 	}
149 
150 	if (i == (lldev->nr_tres - 1))
151 		return -ENOMEM;
152 
153 	tre = &lldev->trepool[i];
154 	tre->dma_sig = sig;
155 	tre->dev_name = dev_name;
156 	tre->callback = callback;
157 	tre->data = data;
158 	tre->idx = i;
159 	tre->status = 0;
160 	tre->queued = 0;
161 	tre->err_code = 0;
162 	tre->err_info = 0;
163 	tre->lldev = lldev;
164 	tre_local = &tre->tre_local[0];
165 	tre_local[HIDMA_TRE_CFG_IDX] = (lldev->chidx & 0xFF) << 8;
166 	tre_local[HIDMA_TRE_CFG_IDX] |= BIT(16);	/* set IEOB */
167 	*tre_ch = i;
168 	if (callback)
169 		callback(data);
170 	return 0;
171 }
172 
173 /*
174  * Multiple TREs may be queued and waiting in the pending queue.
175  */
176 static void hidma_ll_tre_complete(unsigned long arg)
177 {
178 	struct hidma_lldev *lldev = (struct hidma_lldev *)arg;
179 	struct hidma_tre *tre;
180 
181 	while (kfifo_out(&lldev->handoff_fifo, &tre, 1)) {
182 		/* call the user if it has been read by the hardware */
183 		if (tre->callback)
184 			tre->callback(tre->data);
185 	}
186 }
187 
188 static int hidma_post_completed(struct hidma_lldev *lldev, u8 err_info,
189 				u8 err_code)
190 {
191 	struct hidma_tre *tre;
192 	unsigned long flags;
193 	u32 tre_iterator;
194 
195 	spin_lock_irqsave(&lldev->lock, flags);
196 
197 	tre_iterator = lldev->tre_processed_off;
198 	tre = lldev->pending_tre_list[tre_iterator / HIDMA_TRE_SIZE];
199 	if (!tre) {
200 		spin_unlock_irqrestore(&lldev->lock, flags);
201 		dev_warn(lldev->dev, "tre_index [%d] and tre out of sync\n",
202 			 tre_iterator / HIDMA_TRE_SIZE);
203 		return -EINVAL;
204 	}
205 	lldev->pending_tre_list[tre->tre_index] = NULL;
206 
207 	/*
208 	 * Keep track of pending TREs that SW is expecting to receive
209 	 * from HW. We got one now. Decrement our counter.
210 	 */
211 	if (atomic_dec_return(&lldev->pending_tre_count) < 0) {
212 		dev_warn(lldev->dev, "tre count mismatch on completion");
213 		atomic_set(&lldev->pending_tre_count, 0);
214 	}
215 
216 	HIDMA_INCREMENT_ITERATOR(tre_iterator, HIDMA_TRE_SIZE,
217 				 lldev->tre_ring_size);
218 	lldev->tre_processed_off = tre_iterator;
219 	spin_unlock_irqrestore(&lldev->lock, flags);
220 
221 	tre->err_info = err_info;
222 	tre->err_code = err_code;
223 	tre->queued = 0;
224 
225 	kfifo_put(&lldev->handoff_fifo, tre);
226 	tasklet_schedule(&lldev->task);
227 
228 	return 0;
229 }
230 
231 /*
232  * Called to handle the interrupt for the channel.
233  * Return a positive number if TRE or EVRE were consumed on this run.
234  * Return a positive number if there are pending TREs or EVREs.
235  * Return 0 if there is nothing to consume or no pending TREs/EVREs found.
236  */
237 static int hidma_handle_tre_completion(struct hidma_lldev *lldev)
238 {
239 	u32 evre_ring_size = lldev->evre_ring_size;
240 	u32 err_info, err_code, evre_write_off;
241 	u32 evre_iterator;
242 	u32 num_completed = 0;
243 
244 	evre_write_off = readl_relaxed(lldev->evca + HIDMA_EVCA_WRITE_PTR_REG);
245 	evre_iterator = lldev->evre_processed_off;
246 
247 	if ((evre_write_off > evre_ring_size) ||
248 	    (evre_write_off % HIDMA_EVRE_SIZE)) {
249 		dev_err(lldev->dev, "HW reports invalid EVRE write offset\n");
250 		return 0;
251 	}
252 
253 	/*
254 	 * By the time control reaches here the number of EVREs and TREs
255 	 * may not match. Only consume the ones that hardware told us.
256 	 */
257 	while ((evre_iterator != evre_write_off)) {
258 		u32 *current_evre = lldev->evre_ring + evre_iterator;
259 		u32 cfg;
260 
261 		cfg = current_evre[HIDMA_EVRE_CFG_IDX];
262 		err_info = cfg >> HIDMA_EVRE_ERRINFO_BIT_POS;
263 		err_info &= HIDMA_EVRE_ERRINFO_MASK;
264 		err_code =
265 		    (cfg >> HIDMA_EVRE_CODE_BIT_POS) & HIDMA_EVRE_CODE_MASK;
266 
267 		if (hidma_post_completed(lldev, err_info, err_code))
268 			break;
269 
270 		HIDMA_INCREMENT_ITERATOR(evre_iterator, HIDMA_EVRE_SIZE,
271 					 evre_ring_size);
272 
273 		/*
274 		 * Read the new event descriptor written by the HW.
275 		 * As we are processing the delivered events, other events
276 		 * get queued to the SW for processing.
277 		 */
278 		evre_write_off =
279 		    readl_relaxed(lldev->evca + HIDMA_EVCA_WRITE_PTR_REG);
280 		num_completed++;
281 
282 		/*
283 		 * An error interrupt might have arrived while we are processing
284 		 * the completed interrupt.
285 		 */
286 		if (!hidma_ll_isenabled(lldev))
287 			break;
288 	}
289 
290 	if (num_completed) {
291 		u32 evre_read_off = (lldev->evre_processed_off +
292 				     HIDMA_EVRE_SIZE * num_completed);
293 		evre_read_off = evre_read_off % evre_ring_size;
294 		writel(evre_read_off, lldev->evca + HIDMA_EVCA_DOORBELL_REG);
295 
296 		/* record the last processed tre offset */
297 		lldev->evre_processed_off = evre_read_off;
298 	}
299 
300 	return num_completed;
301 }
302 
303 void hidma_cleanup_pending_tre(struct hidma_lldev *lldev, u8 err_info,
304 			       u8 err_code)
305 {
306 	while (atomic_read(&lldev->pending_tre_count)) {
307 		if (hidma_post_completed(lldev, err_info, err_code))
308 			break;
309 	}
310 }
311 
312 static int hidma_ll_reset(struct hidma_lldev *lldev)
313 {
314 	u32 val;
315 	int ret;
316 
317 	val = readl(lldev->trca + HIDMA_TRCA_CTRLSTS_REG);
318 	val &= ~(HIDMA_CH_CONTROL_MASK << 16);
319 	val |= HIDMA_CH_RESET << 16;
320 	writel(val, lldev->trca + HIDMA_TRCA_CTRLSTS_REG);
321 
322 	/*
323 	 * Delay 10ms after reset to allow DMA logic to quiesce.
324 	 * Do a polled read up to 1ms and 10ms maximum.
325 	 */
326 	ret = readl_poll_timeout(lldev->trca + HIDMA_TRCA_CTRLSTS_REG, val,
327 				 HIDMA_CH_STATE(val) == HIDMA_CH_DISABLED,
328 				 1000, 10000);
329 	if (ret) {
330 		dev_err(lldev->dev, "transfer channel did not reset\n");
331 		return ret;
332 	}
333 
334 	val = readl(lldev->evca + HIDMA_EVCA_CTRLSTS_REG);
335 	val &= ~(HIDMA_CH_CONTROL_MASK << 16);
336 	val |= HIDMA_CH_RESET << 16;
337 	writel(val, lldev->evca + HIDMA_EVCA_CTRLSTS_REG);
338 
339 	/*
340 	 * Delay 10ms after reset to allow DMA logic to quiesce.
341 	 * Do a polled read up to 1ms and 10ms maximum.
342 	 */
343 	ret = readl_poll_timeout(lldev->evca + HIDMA_EVCA_CTRLSTS_REG, val,
344 				 HIDMA_CH_STATE(val) == HIDMA_CH_DISABLED,
345 				 1000, 10000);
346 	if (ret)
347 		return ret;
348 
349 	lldev->trch_state = HIDMA_CH_DISABLED;
350 	lldev->evch_state = HIDMA_CH_DISABLED;
351 	return 0;
352 }
353 
354 /*
355  * The interrupt handler for HIDMA will try to consume as many pending
356  * EVRE from the event queue as possible. Each EVRE has an associated
357  * TRE that holds the user interface parameters. EVRE reports the
358  * result of the transaction. Hardware guarantees ordering between EVREs
359  * and TREs. We use last processed offset to figure out which TRE is
360  * associated with which EVRE. If two TREs are consumed by HW, the EVREs
361  * are in order in the event ring.
362  *
363  * This handler will do a one pass for consuming EVREs. Other EVREs may
364  * be delivered while we are working. It will try to consume incoming
365  * EVREs one more time and return.
366  *
367  * For unprocessed EVREs, hardware will trigger another interrupt until
368  * all the interrupt bits are cleared.
369  *
370  * Hardware guarantees that by the time interrupt is observed, all data
371  * transactions in flight are delivered to their respective places and
372  * are visible to the CPU.
373  *
374  * On demand paging for IOMMU is only supported for PCIe via PRI
375  * (Page Request Interface) not for HIDMA. All other hardware instances
376  * including HIDMA work on pinned DMA addresses.
377  *
378  * HIDMA is not aware of IOMMU presence since it follows the DMA API. All
379  * IOMMU latency will be built into the data movement time. By the time
380  * interrupt happens, IOMMU lookups + data movement has already taken place.
381  *
382  * While the first read in a typical PCI endpoint ISR flushes all outstanding
383  * requests traditionally to the destination, this concept does not apply
384  * here for this HW.
385  */
386 static void hidma_ll_int_handler_internal(struct hidma_lldev *lldev, int cause)
387 {
388 	unsigned long irqflags;
389 
390 	if (cause & HIDMA_ERR_INT_MASK) {
391 		dev_err(lldev->dev, "error 0x%x, disabling...\n",
392 				cause);
393 
394 		/* Clear out pending interrupts */
395 		writel(cause, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
396 
397 		/* No further submissions. */
398 		hidma_ll_disable(lldev);
399 
400 		/* Driver completes the txn and intimates the client.*/
401 		hidma_cleanup_pending_tre(lldev, 0xFF,
402 					  HIDMA_EVRE_STATUS_ERROR);
403 
404 		return;
405 	}
406 
407 	spin_lock_irqsave(&lldev->lock, irqflags);
408 	writel_relaxed(cause, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
409 	spin_unlock_irqrestore(&lldev->lock, irqflags);
410 
411 	/*
412 	 * Fine tuned for this HW...
413 	 *
414 	 * This ISR has been designed for this particular hardware. Relaxed
415 	 * read and write accessors are used for performance reasons due to
416 	 * interrupt delivery guarantees. Do not copy this code blindly and
417 	 * expect that to work.
418 	 *
419 	 * Try to consume as many EVREs as possible.
420 	 */
421 	hidma_handle_tre_completion(lldev);
422 }
423 
424 irqreturn_t hidma_ll_inthandler(int chirq, void *arg)
425 {
426 	struct hidma_lldev *lldev = arg;
427 	u32 status;
428 	u32 enable;
429 	u32 cause;
430 
431 	status = readl_relaxed(lldev->evca + HIDMA_EVCA_IRQ_STAT_REG);
432 	enable = readl_relaxed(lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
433 	cause = status & enable;
434 
435 	while (cause) {
436 		hidma_ll_int_handler_internal(lldev, cause);
437 
438 		/*
439 		 * Another interrupt might have arrived while we are
440 		 * processing this one. Read the new cause.
441 		 */
442 		status = readl_relaxed(lldev->evca + HIDMA_EVCA_IRQ_STAT_REG);
443 		enable = readl_relaxed(lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
444 		cause = status & enable;
445 	}
446 
447 	return IRQ_HANDLED;
448 }
449 
450 irqreturn_t hidma_ll_inthandler_msi(int chirq, void *arg, int cause)
451 {
452 	struct hidma_lldev *lldev = arg;
453 
454 	hidma_ll_int_handler_internal(lldev, cause);
455 	return IRQ_HANDLED;
456 }
457 
458 int hidma_ll_enable(struct hidma_lldev *lldev)
459 {
460 	u32 val;
461 	int ret;
462 
463 	val = readl(lldev->evca + HIDMA_EVCA_CTRLSTS_REG);
464 	val &= ~(HIDMA_CH_CONTROL_MASK << 16);
465 	val |= HIDMA_CH_ENABLE << 16;
466 	writel(val, lldev->evca + HIDMA_EVCA_CTRLSTS_REG);
467 
468 	ret = readl_poll_timeout(lldev->evca + HIDMA_EVCA_CTRLSTS_REG, val,
469 				 hidma_is_chan_enabled(HIDMA_CH_STATE(val)),
470 				 1000, 10000);
471 	if (ret) {
472 		dev_err(lldev->dev, "event channel did not get enabled\n");
473 		return ret;
474 	}
475 
476 	val = readl(lldev->trca + HIDMA_TRCA_CTRLSTS_REG);
477 	val &= ~(HIDMA_CH_CONTROL_MASK << 16);
478 	val |= HIDMA_CH_ENABLE << 16;
479 	writel(val, lldev->trca + HIDMA_TRCA_CTRLSTS_REG);
480 
481 	ret = readl_poll_timeout(lldev->trca + HIDMA_TRCA_CTRLSTS_REG, val,
482 				 hidma_is_chan_enabled(HIDMA_CH_STATE(val)),
483 				 1000, 10000);
484 	if (ret) {
485 		dev_err(lldev->dev, "transfer channel did not get enabled\n");
486 		return ret;
487 	}
488 
489 	lldev->trch_state = HIDMA_CH_ENABLED;
490 	lldev->evch_state = HIDMA_CH_ENABLED;
491 
492 	/* enable irqs */
493 	writel(ENABLE_IRQS, lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
494 
495 	return 0;
496 }
497 
498 void hidma_ll_start(struct hidma_lldev *lldev)
499 {
500 	unsigned long irqflags;
501 
502 	spin_lock_irqsave(&lldev->lock, irqflags);
503 	writel(lldev->tre_write_offset, lldev->trca + HIDMA_TRCA_DOORBELL_REG);
504 	spin_unlock_irqrestore(&lldev->lock, irqflags);
505 }
506 
507 bool hidma_ll_isenabled(struct hidma_lldev *lldev)
508 {
509 	u32 val;
510 
511 	val = readl(lldev->trca + HIDMA_TRCA_CTRLSTS_REG);
512 	lldev->trch_state = HIDMA_CH_STATE(val);
513 	val = readl(lldev->evca + HIDMA_EVCA_CTRLSTS_REG);
514 	lldev->evch_state = HIDMA_CH_STATE(val);
515 
516 	/* both channels have to be enabled before calling this function */
517 	if (hidma_is_chan_enabled(lldev->trch_state) &&
518 	    hidma_is_chan_enabled(lldev->evch_state))
519 		return true;
520 
521 	return false;
522 }
523 
524 void hidma_ll_queue_request(struct hidma_lldev *lldev, u32 tre_ch)
525 {
526 	struct hidma_tre *tre;
527 	unsigned long flags;
528 
529 	tre = &lldev->trepool[tre_ch];
530 
531 	/* copy the TRE into its location in the TRE ring */
532 	spin_lock_irqsave(&lldev->lock, flags);
533 	tre->tre_index = lldev->tre_write_offset / HIDMA_TRE_SIZE;
534 	lldev->pending_tre_list[tre->tre_index] = tre;
535 	memcpy(lldev->tre_ring + lldev->tre_write_offset,
536 			&tre->tre_local[0], HIDMA_TRE_SIZE);
537 	tre->err_code = 0;
538 	tre->err_info = 0;
539 	tre->queued = 1;
540 	atomic_inc(&lldev->pending_tre_count);
541 	lldev->tre_write_offset = (lldev->tre_write_offset + HIDMA_TRE_SIZE)
542 					% lldev->tre_ring_size;
543 	spin_unlock_irqrestore(&lldev->lock, flags);
544 }
545 
546 /*
547  * Note that even though we stop this channel if there is a pending transaction
548  * in flight it will complete and follow the callback. This request will
549  * prevent further requests to be made.
550  */
551 int hidma_ll_disable(struct hidma_lldev *lldev)
552 {
553 	u32 val;
554 	int ret;
555 
556 	/* The channel needs to be in working state */
557 	if (!hidma_ll_isenabled(lldev))
558 		return 0;
559 
560 	val = readl(lldev->trca + HIDMA_TRCA_CTRLSTS_REG);
561 	val &= ~(HIDMA_CH_CONTROL_MASK << 16);
562 	val |= HIDMA_CH_SUSPEND << 16;
563 	writel(val, lldev->trca + HIDMA_TRCA_CTRLSTS_REG);
564 
565 	/*
566 	 * Start the wait right after the suspend is confirmed.
567 	 * Do a polled read up to 1ms and 10ms maximum.
568 	 */
569 	ret = readl_poll_timeout(lldev->trca + HIDMA_TRCA_CTRLSTS_REG, val,
570 				 HIDMA_CH_STATE(val) == HIDMA_CH_SUSPENDED,
571 				 1000, 10000);
572 	if (ret)
573 		return ret;
574 
575 	val = readl(lldev->evca + HIDMA_EVCA_CTRLSTS_REG);
576 	val &= ~(HIDMA_CH_CONTROL_MASK << 16);
577 	val |= HIDMA_CH_SUSPEND << 16;
578 	writel(val, lldev->evca + HIDMA_EVCA_CTRLSTS_REG);
579 
580 	/*
581 	 * Start the wait right after the suspend is confirmed
582 	 * Delay up to 10ms after reset to allow DMA logic to quiesce.
583 	 */
584 	ret = readl_poll_timeout(lldev->evca + HIDMA_EVCA_CTRLSTS_REG, val,
585 				 HIDMA_CH_STATE(val) == HIDMA_CH_SUSPENDED,
586 				 1000, 10000);
587 	if (ret)
588 		return ret;
589 
590 	lldev->trch_state = HIDMA_CH_SUSPENDED;
591 	lldev->evch_state = HIDMA_CH_SUSPENDED;
592 
593 	/* disable interrupts */
594 	writel(0, lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
595 	return 0;
596 }
597 
598 void hidma_ll_set_transfer_params(struct hidma_lldev *lldev, u32 tre_ch,
599 				  dma_addr_t src, dma_addr_t dest, u32 len,
600 				  u32 flags, u32 txntype)
601 {
602 	struct hidma_tre *tre;
603 	u32 *tre_local;
604 
605 	if (tre_ch >= lldev->nr_tres) {
606 		dev_err(lldev->dev, "invalid TRE number in transfer params:%d",
607 			tre_ch);
608 		return;
609 	}
610 
611 	tre = &lldev->trepool[tre_ch];
612 	if (atomic_read(&tre->allocated) != true) {
613 		dev_err(lldev->dev, "trying to set params on an unused TRE:%d",
614 			tre_ch);
615 		return;
616 	}
617 
618 	tre_local = &tre->tre_local[0];
619 	tre_local[HIDMA_TRE_CFG_IDX] &= ~GENMASK(7, 0);
620 	tre_local[HIDMA_TRE_CFG_IDX] |= txntype;
621 	tre_local[HIDMA_TRE_LEN_IDX] = len;
622 	tre_local[HIDMA_TRE_SRC_LOW_IDX] = lower_32_bits(src);
623 	tre_local[HIDMA_TRE_SRC_HI_IDX] = upper_32_bits(src);
624 	tre_local[HIDMA_TRE_DEST_LOW_IDX] = lower_32_bits(dest);
625 	tre_local[HIDMA_TRE_DEST_HI_IDX] = upper_32_bits(dest);
626 	tre->int_flags = flags;
627 }
628 
629 /*
630  * Called during initialization and after an error condition
631  * to restore hardware state.
632  */
633 int hidma_ll_setup(struct hidma_lldev *lldev)
634 {
635 	int rc;
636 	u64 addr;
637 	u32 val;
638 	u32 nr_tres = lldev->nr_tres;
639 
640 	atomic_set(&lldev->pending_tre_count, 0);
641 	lldev->tre_processed_off = 0;
642 	lldev->evre_processed_off = 0;
643 	lldev->tre_write_offset = 0;
644 
645 	/* disable interrupts */
646 	writel(0, lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
647 
648 	/* clear all pending interrupts */
649 	val = readl(lldev->evca + HIDMA_EVCA_IRQ_STAT_REG);
650 	writel(val, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
651 
652 	rc = hidma_ll_reset(lldev);
653 	if (rc)
654 		return rc;
655 
656 	/*
657 	 * Clear all pending interrupts again.
658 	 * Otherwise, we observe reset complete interrupts.
659 	 */
660 	val = readl(lldev->evca + HIDMA_EVCA_IRQ_STAT_REG);
661 	writel(val, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
662 
663 	/* disable interrupts again after reset */
664 	writel(0, lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
665 
666 	addr = lldev->tre_dma;
667 	writel(lower_32_bits(addr), lldev->trca + HIDMA_TRCA_RING_LOW_REG);
668 	writel(upper_32_bits(addr), lldev->trca + HIDMA_TRCA_RING_HIGH_REG);
669 	writel(lldev->tre_ring_size, lldev->trca + HIDMA_TRCA_RING_LEN_REG);
670 
671 	addr = lldev->evre_dma;
672 	writel(lower_32_bits(addr), lldev->evca + HIDMA_EVCA_RING_LOW_REG);
673 	writel(upper_32_bits(addr), lldev->evca + HIDMA_EVCA_RING_HIGH_REG);
674 	writel(HIDMA_EVRE_SIZE * nr_tres,
675 			lldev->evca + HIDMA_EVCA_RING_LEN_REG);
676 
677 	/* configure interrupts */
678 	hidma_ll_setup_irq(lldev, lldev->msi_support);
679 
680 	rc = hidma_ll_enable(lldev);
681 	if (rc)
682 		return rc;
683 
684 	return rc;
685 }
686 
687 void hidma_ll_setup_irq(struct hidma_lldev *lldev, bool msi)
688 {
689 	u32 val;
690 
691 	lldev->msi_support = msi;
692 
693 	/* disable interrupts again after reset */
694 	writel(0, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
695 	writel(0, lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
696 
697 	/* support IRQ by default */
698 	val = readl(lldev->evca + HIDMA_EVCA_INTCTRL_REG);
699 	val &= ~0xF;
700 	if (!lldev->msi_support)
701 		val = val | 0x1;
702 	writel(val, lldev->evca + HIDMA_EVCA_INTCTRL_REG);
703 
704 	/* clear all pending interrupts and enable them */
705 	writel(ENABLE_IRQS, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
706 	writel(ENABLE_IRQS, lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
707 }
708 
709 struct hidma_lldev *hidma_ll_init(struct device *dev, u32 nr_tres,
710 				  void __iomem *trca, void __iomem *evca,
711 				  u8 chidx)
712 {
713 	u32 required_bytes;
714 	struct hidma_lldev *lldev;
715 	int rc;
716 	size_t sz;
717 
718 	if (!trca || !evca || !dev || !nr_tres)
719 		return NULL;
720 
721 	/* need at least four TREs */
722 	if (nr_tres < 4)
723 		return NULL;
724 
725 	/* need an extra space */
726 	nr_tres += 1;
727 
728 	lldev = devm_kzalloc(dev, sizeof(struct hidma_lldev), GFP_KERNEL);
729 	if (!lldev)
730 		return NULL;
731 
732 	lldev->evca = evca;
733 	lldev->trca = trca;
734 	lldev->dev = dev;
735 	sz = sizeof(struct hidma_tre);
736 	lldev->trepool = devm_kcalloc(lldev->dev, nr_tres, sz, GFP_KERNEL);
737 	if (!lldev->trepool)
738 		return NULL;
739 
740 	required_bytes = sizeof(lldev->pending_tre_list[0]);
741 	lldev->pending_tre_list = devm_kcalloc(dev, nr_tres, required_bytes,
742 					       GFP_KERNEL);
743 	if (!lldev->pending_tre_list)
744 		return NULL;
745 
746 	sz = (HIDMA_TRE_SIZE + 1) * nr_tres;
747 	lldev->tre_ring = dmam_alloc_coherent(dev, sz, &lldev->tre_dma,
748 					      GFP_KERNEL);
749 	if (!lldev->tre_ring)
750 		return NULL;
751 
752 	memset(lldev->tre_ring, 0, (HIDMA_TRE_SIZE + 1) * nr_tres);
753 	lldev->tre_ring_size = HIDMA_TRE_SIZE * nr_tres;
754 	lldev->nr_tres = nr_tres;
755 
756 	/* the TRE ring has to be TRE_SIZE aligned */
757 	if (!IS_ALIGNED(lldev->tre_dma, HIDMA_TRE_SIZE)) {
758 		u8 tre_ring_shift;
759 
760 		tre_ring_shift = lldev->tre_dma % HIDMA_TRE_SIZE;
761 		tre_ring_shift = HIDMA_TRE_SIZE - tre_ring_shift;
762 		lldev->tre_dma += tre_ring_shift;
763 		lldev->tre_ring += tre_ring_shift;
764 	}
765 
766 	sz = (HIDMA_EVRE_SIZE + 1) * nr_tres;
767 	lldev->evre_ring = dmam_alloc_coherent(dev, sz, &lldev->evre_dma,
768 					       GFP_KERNEL);
769 	if (!lldev->evre_ring)
770 		return NULL;
771 
772 	memset(lldev->evre_ring, 0, (HIDMA_EVRE_SIZE + 1) * nr_tres);
773 	lldev->evre_ring_size = HIDMA_EVRE_SIZE * nr_tres;
774 
775 	/* the EVRE ring has to be EVRE_SIZE aligned */
776 	if (!IS_ALIGNED(lldev->evre_dma, HIDMA_EVRE_SIZE)) {
777 		u8 evre_ring_shift;
778 
779 		evre_ring_shift = lldev->evre_dma % HIDMA_EVRE_SIZE;
780 		evre_ring_shift = HIDMA_EVRE_SIZE - evre_ring_shift;
781 		lldev->evre_dma += evre_ring_shift;
782 		lldev->evre_ring += evre_ring_shift;
783 	}
784 	lldev->nr_tres = nr_tres;
785 	lldev->chidx = chidx;
786 
787 	sz = nr_tres * sizeof(struct hidma_tre *);
788 	rc = kfifo_alloc(&lldev->handoff_fifo, sz, GFP_KERNEL);
789 	if (rc)
790 		return NULL;
791 
792 	rc = hidma_ll_setup(lldev);
793 	if (rc)
794 		return NULL;
795 
796 	spin_lock_init(&lldev->lock);
797 	tasklet_init(&lldev->task, hidma_ll_tre_complete, (unsigned long)lldev);
798 	lldev->initialized = 1;
799 	writel(ENABLE_IRQS, lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
800 	return lldev;
801 }
802 
803 int hidma_ll_uninit(struct hidma_lldev *lldev)
804 {
805 	u32 required_bytes;
806 	int rc = 0;
807 	u32 val;
808 
809 	if (!lldev)
810 		return -ENODEV;
811 
812 	if (!lldev->initialized)
813 		return 0;
814 
815 	lldev->initialized = 0;
816 
817 	required_bytes = sizeof(struct hidma_tre) * lldev->nr_tres;
818 	tasklet_kill(&lldev->task);
819 	memset(lldev->trepool, 0, required_bytes);
820 	lldev->trepool = NULL;
821 	atomic_set(&lldev->pending_tre_count, 0);
822 	lldev->tre_write_offset = 0;
823 
824 	rc = hidma_ll_reset(lldev);
825 
826 	/*
827 	 * Clear all pending interrupts again.
828 	 * Otherwise, we observe reset complete interrupts.
829 	 */
830 	val = readl(lldev->evca + HIDMA_EVCA_IRQ_STAT_REG);
831 	writel(val, lldev->evca + HIDMA_EVCA_IRQ_CLR_REG);
832 	writel(0, lldev->evca + HIDMA_EVCA_IRQ_EN_REG);
833 	return rc;
834 }
835 
836 enum dma_status hidma_ll_status(struct hidma_lldev *lldev, u32 tre_ch)
837 {
838 	enum dma_status ret = DMA_ERROR;
839 	struct hidma_tre *tre;
840 	unsigned long flags;
841 	u8 err_code;
842 
843 	spin_lock_irqsave(&lldev->lock, flags);
844 
845 	tre = &lldev->trepool[tre_ch];
846 	err_code = tre->err_code;
847 
848 	if (err_code & HIDMA_EVRE_STATUS_COMPLETE)
849 		ret = DMA_COMPLETE;
850 	else if (err_code & HIDMA_EVRE_STATUS_ERROR)
851 		ret = DMA_ERROR;
852 	else
853 		ret = DMA_IN_PROGRESS;
854 	spin_unlock_irqrestore(&lldev->lock, flags);
855 
856 	return ret;
857 }
858