xref: /openbmc/linux/drivers/dma/tegra210-adma.c (revision 32981ea5)
1 /*
2  * ADMA driver for Nvidia's Tegra210 ADMA controller.
3  *
4  * Copyright (c) 2016, NVIDIA CORPORATION.  All rights reserved.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #include <linux/clk.h>
20 #include <linux/iopoll.h>
21 #include <linux/module.h>
22 #include <linux/of_device.h>
23 #include <linux/of_dma.h>
24 #include <linux/of_irq.h>
25 #include <linux/pm_clock.h>
26 #include <linux/pm_runtime.h>
27 #include <linux/slab.h>
28 
29 #include "virt-dma.h"
30 
31 #define ADMA_CH_CMD					0x00
32 #define ADMA_CH_STATUS					0x0c
33 #define ADMA_CH_STATUS_XFER_EN				BIT(0)
34 
35 #define ADMA_CH_INT_STATUS				0x10
36 #define ADMA_CH_INT_STATUS_XFER_DONE			BIT(0)
37 
38 #define ADMA_CH_INT_CLEAR				0x1c
39 #define ADMA_CH_CTRL					0x24
40 #define ADMA_CH_CTRL_TX_REQ(val)			(((val) & 0xf) << 28)
41 #define ADMA_CH_CTRL_TX_REQ_MAX				10
42 #define ADMA_CH_CTRL_RX_REQ(val)			(((val) & 0xf) << 24)
43 #define ADMA_CH_CTRL_RX_REQ_MAX				10
44 #define ADMA_CH_CTRL_DIR(val)				(((val) & 0xf) << 12)
45 #define ADMA_CH_CTRL_DIR_AHUB2MEM			2
46 #define ADMA_CH_CTRL_DIR_MEM2AHUB			4
47 #define ADMA_CH_CTRL_MODE_CONTINUOUS			(2 << 8)
48 #define ADMA_CH_CTRL_FLOWCTRL_EN			BIT(1)
49 
50 #define ADMA_CH_CONFIG					0x28
51 #define ADMA_CH_CONFIG_SRC_BUF(val)			(((val) & 0x7) << 28)
52 #define ADMA_CH_CONFIG_TRG_BUF(val)			(((val) & 0x7) << 24)
53 #define ADMA_CH_CONFIG_BURST_SIZE(val)			(((val) & 0x7) << 20)
54 #define ADMA_CH_CONFIG_BURST_16				5
55 #define ADMA_CH_CONFIG_WEIGHT_FOR_WRR(val)		((val) & 0xf)
56 #define ADMA_CH_CONFIG_MAX_BUFS				8
57 
58 #define ADMA_CH_FIFO_CTRL				0x2c
59 #define ADMA_CH_FIFO_CTRL_OVRFW_THRES(val)		(((val) & 0xf) << 24)
60 #define ADMA_CH_FIFO_CTRL_STARV_THRES(val)		(((val) & 0xf) << 16)
61 #define ADMA_CH_FIFO_CTRL_TX_SIZE(val)			(((val) & 0xf) << 8)
62 #define ADMA_CH_FIFO_CTRL_RX_SIZE(val)			((val) & 0xf)
63 
64 #define ADMA_CH_LOWER_SRC_ADDR				0x34
65 #define ADMA_CH_LOWER_TRG_ADDR				0x3c
66 #define ADMA_CH_TC					0x44
67 #define ADMA_CH_TC_COUNT_MASK				0x3ffffffc
68 
69 #define ADMA_CH_XFER_STATUS				0x54
70 #define ADMA_CH_XFER_STATUS_COUNT_MASK			0xffff
71 
72 #define ADMA_GLOBAL_CMD					0xc00
73 #define ADMA_GLOBAL_SOFT_RESET				0xc04
74 #define ADMA_GLOBAL_INT_CLEAR				0xc20
75 #define ADMA_GLOBAL_CTRL				0xc24
76 
77 #define ADMA_CH_REG_OFFSET(a)				(a * 0x80)
78 
79 #define ADMA_CH_FIFO_CTRL_DEFAULT	(ADMA_CH_FIFO_CTRL_OVRFW_THRES(1) | \
80 					 ADMA_CH_FIFO_CTRL_STARV_THRES(1) | \
81 					 ADMA_CH_FIFO_CTRL_TX_SIZE(3)     | \
82 					 ADMA_CH_FIFO_CTRL_RX_SIZE(3))
83 struct tegra_adma;
84 
85 /*
86  * struct tegra_adma_chip_data - Tegra chip specific data
87  * @nr_channels: Number of DMA channels available.
88  */
89 struct tegra_adma_chip_data {
90 	int nr_channels;
91 };
92 
93 /*
94  * struct tegra_adma_chan_regs - Tegra ADMA channel registers
95  */
96 struct tegra_adma_chan_regs {
97 	unsigned int ctrl;
98 	unsigned int config;
99 	unsigned int src_addr;
100 	unsigned int trg_addr;
101 	unsigned int fifo_ctrl;
102 	unsigned int tc;
103 };
104 
105 /*
106  * struct tegra_adma_desc - Tegra ADMA descriptor to manage transfer requests.
107  */
108 struct tegra_adma_desc {
109 	struct virt_dma_desc		vd;
110 	struct tegra_adma_chan_regs	ch_regs;
111 	size_t				buf_len;
112 	size_t				period_len;
113 	size_t				num_periods;
114 };
115 
116 /*
117  * struct tegra_adma_chan - Tegra ADMA channel information
118  */
119 struct tegra_adma_chan {
120 	struct virt_dma_chan		vc;
121 	struct tegra_adma_desc		*desc;
122 	struct tegra_adma		*tdma;
123 	int				irq;
124 	void __iomem			*chan_addr;
125 
126 	/* Slave channel configuration info */
127 	struct dma_slave_config		sconfig;
128 	enum dma_transfer_direction	sreq_dir;
129 	unsigned int			sreq_index;
130 	bool				sreq_reserved;
131 
132 	/* Transfer count and position info */
133 	unsigned int			tx_buf_count;
134 	unsigned int			tx_buf_pos;
135 };
136 
137 /*
138  * struct tegra_adma - Tegra ADMA controller information
139  */
140 struct tegra_adma {
141 	struct dma_device		dma_dev;
142 	struct device			*dev;
143 	void __iomem			*base_addr;
144 	unsigned int			nr_channels;
145 	unsigned long			rx_requests_reserved;
146 	unsigned long			tx_requests_reserved;
147 
148 	/* Used to store global command register state when suspending */
149 	unsigned int			global_cmd;
150 
151 	/* Last member of the structure */
152 	struct tegra_adma_chan		channels[0];
153 };
154 
155 static inline void tdma_write(struct tegra_adma *tdma, u32 reg, u32 val)
156 {
157 	writel(val, tdma->base_addr + reg);
158 }
159 
160 static inline u32 tdma_read(struct tegra_adma *tdma, u32 reg)
161 {
162 	return readl(tdma->base_addr + reg);
163 }
164 
165 static inline void tdma_ch_write(struct tegra_adma_chan *tdc, u32 reg, u32 val)
166 {
167 	writel(val, tdc->chan_addr + reg);
168 }
169 
170 static inline u32 tdma_ch_read(struct tegra_adma_chan *tdc, u32 reg)
171 {
172 	return readl(tdc->chan_addr + reg);
173 }
174 
175 static inline struct tegra_adma_chan *to_tegra_adma_chan(struct dma_chan *dc)
176 {
177 	return container_of(dc, struct tegra_adma_chan, vc.chan);
178 }
179 
180 static inline struct tegra_adma_desc *to_tegra_adma_desc(
181 		struct dma_async_tx_descriptor *td)
182 {
183 	return container_of(td, struct tegra_adma_desc, vd.tx);
184 }
185 
186 static inline struct device *tdc2dev(struct tegra_adma_chan *tdc)
187 {
188 	return tdc->tdma->dev;
189 }
190 
191 static void tegra_adma_desc_free(struct virt_dma_desc *vd)
192 {
193 	kfree(container_of(vd, struct tegra_adma_desc, vd));
194 }
195 
196 static int tegra_adma_slave_config(struct dma_chan *dc,
197 				   struct dma_slave_config *sconfig)
198 {
199 	struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
200 
201 	memcpy(&tdc->sconfig, sconfig, sizeof(*sconfig));
202 
203 	return 0;
204 }
205 
206 static int tegra_adma_init(struct tegra_adma *tdma)
207 {
208 	u32 status;
209 	int ret;
210 
211 	/* Clear any interrupts */
212 	tdma_write(tdma, ADMA_GLOBAL_INT_CLEAR, 0x1);
213 
214 	/* Assert soft reset */
215 	tdma_write(tdma, ADMA_GLOBAL_SOFT_RESET, 0x1);
216 
217 	/* Wait for reset to clear */
218 	ret = readx_poll_timeout(readl,
219 				 tdma->base_addr + ADMA_GLOBAL_SOFT_RESET,
220 				 status, status == 0, 20, 10000);
221 	if (ret)
222 		return ret;
223 
224 	/* Enable global ADMA registers */
225 	tdma_write(tdma, ADMA_GLOBAL_CMD, 1);
226 
227 	return 0;
228 }
229 
230 static int tegra_adma_request_alloc(struct tegra_adma_chan *tdc,
231 				    enum dma_transfer_direction direction)
232 {
233 	struct tegra_adma *tdma = tdc->tdma;
234 	unsigned int sreq_index = tdc->sreq_index;
235 
236 	if (tdc->sreq_reserved)
237 		return tdc->sreq_dir == direction ? 0 : -EINVAL;
238 
239 	switch (direction) {
240 	case DMA_MEM_TO_DEV:
241 		if (sreq_index > ADMA_CH_CTRL_TX_REQ_MAX) {
242 			dev_err(tdma->dev, "invalid DMA request\n");
243 			return -EINVAL;
244 		}
245 
246 		if (test_and_set_bit(sreq_index, &tdma->tx_requests_reserved)) {
247 			dev_err(tdma->dev, "DMA request reserved\n");
248 			return -EINVAL;
249 		}
250 		break;
251 
252 	case DMA_DEV_TO_MEM:
253 		if (sreq_index > ADMA_CH_CTRL_RX_REQ_MAX) {
254 			dev_err(tdma->dev, "invalid DMA request\n");
255 			return -EINVAL;
256 		}
257 
258 		if (test_and_set_bit(sreq_index, &tdma->rx_requests_reserved)) {
259 			dev_err(tdma->dev, "DMA request reserved\n");
260 			return -EINVAL;
261 		}
262 		break;
263 
264 	default:
265 		dev_WARN(tdma->dev, "channel %s has invalid transfer type\n",
266 			 dma_chan_name(&tdc->vc.chan));
267 		return -EINVAL;
268 	}
269 
270 	tdc->sreq_dir = direction;
271 	tdc->sreq_reserved = true;
272 
273 	return 0;
274 }
275 
276 static void tegra_adma_request_free(struct tegra_adma_chan *tdc)
277 {
278 	struct tegra_adma *tdma = tdc->tdma;
279 
280 	if (!tdc->sreq_reserved)
281 		return;
282 
283 	switch (tdc->sreq_dir) {
284 	case DMA_MEM_TO_DEV:
285 		clear_bit(tdc->sreq_index, &tdma->tx_requests_reserved);
286 		break;
287 
288 	case DMA_DEV_TO_MEM:
289 		clear_bit(tdc->sreq_index, &tdma->rx_requests_reserved);
290 		break;
291 
292 	default:
293 		dev_WARN(tdma->dev, "channel %s has invalid transfer type\n",
294 			 dma_chan_name(&tdc->vc.chan));
295 		return;
296 	}
297 
298 	tdc->sreq_reserved = false;
299 }
300 
301 static u32 tegra_adma_irq_status(struct tegra_adma_chan *tdc)
302 {
303 	u32 status = tdma_ch_read(tdc, ADMA_CH_INT_STATUS);
304 
305 	return status & ADMA_CH_INT_STATUS_XFER_DONE;
306 }
307 
308 static u32 tegra_adma_irq_clear(struct tegra_adma_chan *tdc)
309 {
310 	u32 status = tegra_adma_irq_status(tdc);
311 
312 	if (status)
313 		tdma_ch_write(tdc, ADMA_CH_INT_CLEAR, status);
314 
315 	return status;
316 }
317 
318 static void tegra_adma_stop(struct tegra_adma_chan *tdc)
319 {
320 	unsigned int status;
321 
322 	/* Disable ADMA */
323 	tdma_ch_write(tdc, ADMA_CH_CMD, 0);
324 
325 	/* Clear interrupt status */
326 	tegra_adma_irq_clear(tdc);
327 
328 	if (readx_poll_timeout_atomic(readl, tdc->chan_addr + ADMA_CH_STATUS,
329 			status, !(status & ADMA_CH_STATUS_XFER_EN),
330 			20, 10000)) {
331 		dev_err(tdc2dev(tdc), "unable to stop DMA channel\n");
332 		return;
333 	}
334 
335 	kfree(tdc->desc);
336 	tdc->desc = NULL;
337 }
338 
339 static void tegra_adma_start(struct tegra_adma_chan *tdc)
340 {
341 	struct virt_dma_desc *vd = vchan_next_desc(&tdc->vc);
342 	struct tegra_adma_chan_regs *ch_regs;
343 	struct tegra_adma_desc *desc;
344 
345 	if (!vd)
346 		return;
347 
348 	list_del(&vd->node);
349 
350 	desc = to_tegra_adma_desc(&vd->tx);
351 
352 	if (!desc) {
353 		dev_warn(tdc2dev(tdc), "unable to start DMA, no descriptor\n");
354 		return;
355 	}
356 
357 	ch_regs = &desc->ch_regs;
358 
359 	tdc->tx_buf_pos = 0;
360 	tdc->tx_buf_count = 0;
361 	tdma_ch_write(tdc, ADMA_CH_TC, ch_regs->tc);
362 	tdma_ch_write(tdc, ADMA_CH_CTRL, ch_regs->ctrl);
363 	tdma_ch_write(tdc, ADMA_CH_LOWER_SRC_ADDR, ch_regs->src_addr);
364 	tdma_ch_write(tdc, ADMA_CH_LOWER_TRG_ADDR, ch_regs->trg_addr);
365 	tdma_ch_write(tdc, ADMA_CH_FIFO_CTRL, ch_regs->fifo_ctrl);
366 	tdma_ch_write(tdc, ADMA_CH_CONFIG, ch_regs->config);
367 
368 	/* Start ADMA */
369 	tdma_ch_write(tdc, ADMA_CH_CMD, 1);
370 
371 	tdc->desc = desc;
372 }
373 
374 static unsigned int tegra_adma_get_residue(struct tegra_adma_chan *tdc)
375 {
376 	struct tegra_adma_desc *desc = tdc->desc;
377 	unsigned int max = ADMA_CH_XFER_STATUS_COUNT_MASK + 1;
378 	unsigned int pos = tdma_ch_read(tdc, ADMA_CH_XFER_STATUS);
379 	unsigned int periods_remaining;
380 
381 	/*
382 	 * Handle wrap around of buffer count register
383 	 */
384 	if (pos < tdc->tx_buf_pos)
385 		tdc->tx_buf_count += pos + (max - tdc->tx_buf_pos);
386 	else
387 		tdc->tx_buf_count += pos - tdc->tx_buf_pos;
388 
389 	periods_remaining = tdc->tx_buf_count % desc->num_periods;
390 	tdc->tx_buf_pos = pos;
391 
392 	return desc->buf_len - (periods_remaining * desc->period_len);
393 }
394 
395 static irqreturn_t tegra_adma_isr(int irq, void *dev_id)
396 {
397 	struct tegra_adma_chan *tdc = dev_id;
398 	unsigned long status;
399 	unsigned long flags;
400 
401 	spin_lock_irqsave(&tdc->vc.lock, flags);
402 
403 	status = tegra_adma_irq_clear(tdc);
404 	if (status == 0 || !tdc->desc) {
405 		spin_unlock_irqrestore(&tdc->vc.lock, flags);
406 		return IRQ_NONE;
407 	}
408 
409 	vchan_cyclic_callback(&tdc->desc->vd);
410 
411 	spin_unlock_irqrestore(&tdc->vc.lock, flags);
412 
413 	return IRQ_HANDLED;
414 }
415 
416 static void tegra_adma_issue_pending(struct dma_chan *dc)
417 {
418 	struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
419 	unsigned long flags;
420 
421 	spin_lock_irqsave(&tdc->vc.lock, flags);
422 
423 	if (vchan_issue_pending(&tdc->vc)) {
424 		if (!tdc->desc)
425 			tegra_adma_start(tdc);
426 	}
427 
428 	spin_unlock_irqrestore(&tdc->vc.lock, flags);
429 }
430 
431 static int tegra_adma_terminate_all(struct dma_chan *dc)
432 {
433 	struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
434 	unsigned long flags;
435 	LIST_HEAD(head);
436 
437 	spin_lock_irqsave(&tdc->vc.lock, flags);
438 
439 	if (tdc->desc)
440 		tegra_adma_stop(tdc);
441 
442 	tegra_adma_request_free(tdc);
443 	vchan_get_all_descriptors(&tdc->vc, &head);
444 	spin_unlock_irqrestore(&tdc->vc.lock, flags);
445 	vchan_dma_desc_free_list(&tdc->vc, &head);
446 
447 	return 0;
448 }
449 
450 static enum dma_status tegra_adma_tx_status(struct dma_chan *dc,
451 					    dma_cookie_t cookie,
452 					    struct dma_tx_state *txstate)
453 {
454 	struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
455 	struct tegra_adma_desc *desc;
456 	struct virt_dma_desc *vd;
457 	enum dma_status ret;
458 	unsigned long flags;
459 	unsigned int residual;
460 
461 	ret = dma_cookie_status(dc, cookie, txstate);
462 	if (ret == DMA_COMPLETE || !txstate)
463 		return ret;
464 
465 	spin_lock_irqsave(&tdc->vc.lock, flags);
466 
467 	vd = vchan_find_desc(&tdc->vc, cookie);
468 	if (vd) {
469 		desc = to_tegra_adma_desc(&vd->tx);
470 		residual = desc->ch_regs.tc;
471 	} else if (tdc->desc && tdc->desc->vd.tx.cookie == cookie) {
472 		residual = tegra_adma_get_residue(tdc);
473 	} else {
474 		residual = 0;
475 	}
476 
477 	spin_unlock_irqrestore(&tdc->vc.lock, flags);
478 
479 	dma_set_residue(txstate, residual);
480 
481 	return ret;
482 }
483 
484 static int tegra_adma_set_xfer_params(struct tegra_adma_chan *tdc,
485 				      struct tegra_adma_desc *desc,
486 				      dma_addr_t buf_addr,
487 				      enum dma_transfer_direction direction)
488 {
489 	struct tegra_adma_chan_regs *ch_regs = &desc->ch_regs;
490 	unsigned int burst_size, adma_dir;
491 
492 	if (desc->num_periods > ADMA_CH_CONFIG_MAX_BUFS)
493 		return -EINVAL;
494 
495 	switch (direction) {
496 	case DMA_MEM_TO_DEV:
497 		adma_dir = ADMA_CH_CTRL_DIR_MEM2AHUB;
498 		burst_size = fls(tdc->sconfig.dst_maxburst);
499 		ch_regs->config = ADMA_CH_CONFIG_SRC_BUF(desc->num_periods - 1);
500 		ch_regs->ctrl = ADMA_CH_CTRL_TX_REQ(tdc->sreq_index);
501 		ch_regs->src_addr = buf_addr;
502 		break;
503 
504 	case DMA_DEV_TO_MEM:
505 		adma_dir = ADMA_CH_CTRL_DIR_AHUB2MEM;
506 		burst_size = fls(tdc->sconfig.src_maxburst);
507 		ch_regs->config = ADMA_CH_CONFIG_TRG_BUF(desc->num_periods - 1);
508 		ch_regs->ctrl = ADMA_CH_CTRL_RX_REQ(tdc->sreq_index);
509 		ch_regs->trg_addr = buf_addr;
510 		break;
511 
512 	default:
513 		dev_err(tdc2dev(tdc), "DMA direction is not supported\n");
514 		return -EINVAL;
515 	}
516 
517 	if (!burst_size || burst_size > ADMA_CH_CONFIG_BURST_16)
518 		burst_size = ADMA_CH_CONFIG_BURST_16;
519 
520 	ch_regs->ctrl |= ADMA_CH_CTRL_DIR(adma_dir) |
521 			 ADMA_CH_CTRL_MODE_CONTINUOUS |
522 			 ADMA_CH_CTRL_FLOWCTRL_EN;
523 	ch_regs->config |= ADMA_CH_CONFIG_BURST_SIZE(burst_size);
524 	ch_regs->config |= ADMA_CH_CONFIG_WEIGHT_FOR_WRR(1);
525 	ch_regs->fifo_ctrl = ADMA_CH_FIFO_CTRL_DEFAULT;
526 	ch_regs->tc = desc->period_len & ADMA_CH_TC_COUNT_MASK;
527 
528 	return tegra_adma_request_alloc(tdc, direction);
529 }
530 
531 static struct dma_async_tx_descriptor *tegra_adma_prep_dma_cyclic(
532 	struct dma_chan *dc, dma_addr_t buf_addr, size_t buf_len,
533 	size_t period_len, enum dma_transfer_direction direction,
534 	unsigned long flags)
535 {
536 	struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
537 	struct tegra_adma_desc *desc = NULL;
538 
539 	if (!buf_len || !period_len || period_len > ADMA_CH_TC_COUNT_MASK) {
540 		dev_err(tdc2dev(tdc), "invalid buffer/period len\n");
541 		return NULL;
542 	}
543 
544 	if (buf_len % period_len) {
545 		dev_err(tdc2dev(tdc), "buf_len not a multiple of period_len\n");
546 		return NULL;
547 	}
548 
549 	if (!IS_ALIGNED(buf_addr, 4)) {
550 		dev_err(tdc2dev(tdc), "invalid buffer alignment\n");
551 		return NULL;
552 	}
553 
554 	desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
555 	if (!desc)
556 		return NULL;
557 
558 	desc->buf_len = buf_len;
559 	desc->period_len = period_len;
560 	desc->num_periods = buf_len / period_len;
561 
562 	if (tegra_adma_set_xfer_params(tdc, desc, buf_addr, direction)) {
563 		kfree(desc);
564 		return NULL;
565 	}
566 
567 	return vchan_tx_prep(&tdc->vc, &desc->vd, flags);
568 }
569 
570 static int tegra_adma_alloc_chan_resources(struct dma_chan *dc)
571 {
572 	struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
573 	int ret;
574 
575 	ret = request_irq(tdc->irq, tegra_adma_isr, 0, dma_chan_name(dc), tdc);
576 	if (ret) {
577 		dev_err(tdc2dev(tdc), "failed to get interrupt for %s\n",
578 			dma_chan_name(dc));
579 		return ret;
580 	}
581 
582 	ret = pm_runtime_get_sync(tdc2dev(tdc));
583 	if (ret < 0) {
584 		free_irq(tdc->irq, tdc);
585 		return ret;
586 	}
587 
588 	dma_cookie_init(&tdc->vc.chan);
589 
590 	return 0;
591 }
592 
593 static void tegra_adma_free_chan_resources(struct dma_chan *dc)
594 {
595 	struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
596 
597 	tegra_adma_terminate_all(dc);
598 	vchan_free_chan_resources(&tdc->vc);
599 	tasklet_kill(&tdc->vc.task);
600 	free_irq(tdc->irq, tdc);
601 	pm_runtime_put(tdc2dev(tdc));
602 
603 	tdc->sreq_index = 0;
604 	tdc->sreq_dir = DMA_TRANS_NONE;
605 }
606 
607 static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec,
608 					   struct of_dma *ofdma)
609 {
610 	struct tegra_adma *tdma = ofdma->of_dma_data;
611 	struct tegra_adma_chan *tdc;
612 	struct dma_chan *chan;
613 	unsigned int sreq_index;
614 
615 	if (dma_spec->args_count != 1)
616 		return NULL;
617 
618 	sreq_index = dma_spec->args[0];
619 
620 	if (sreq_index == 0) {
621 		dev_err(tdma->dev, "DMA request must not be 0\n");
622 		return NULL;
623 	}
624 
625 	chan = dma_get_any_slave_channel(&tdma->dma_dev);
626 	if (!chan)
627 		return NULL;
628 
629 	tdc = to_tegra_adma_chan(chan);
630 	tdc->sreq_index = sreq_index;
631 
632 	return chan;
633 }
634 
635 static int tegra_adma_runtime_suspend(struct device *dev)
636 {
637 	struct tegra_adma *tdma = dev_get_drvdata(dev);
638 
639 	tdma->global_cmd = tdma_read(tdma, ADMA_GLOBAL_CMD);
640 
641 	return pm_clk_suspend(dev);
642 }
643 
644 static int tegra_adma_runtime_resume(struct device *dev)
645 {
646 	struct tegra_adma *tdma = dev_get_drvdata(dev);
647 	int ret;
648 
649 	ret = pm_clk_resume(dev);
650 	if (ret)
651 		return ret;
652 
653 	tdma_write(tdma, ADMA_GLOBAL_CMD, tdma->global_cmd);
654 
655 	return 0;
656 }
657 
658 static const struct tegra_adma_chip_data tegra210_chip_data = {
659 	.nr_channels = 22,
660 };
661 
662 static const struct of_device_id tegra_adma_of_match[] = {
663 	{ .compatible = "nvidia,tegra210-adma", .data = &tegra210_chip_data },
664 	{ },
665 };
666 MODULE_DEVICE_TABLE(of, tegra_adma_of_match);
667 
668 static int tegra_adma_probe(struct platform_device *pdev)
669 {
670 	const struct tegra_adma_chip_data *cdata;
671 	struct tegra_adma *tdma;
672 	struct resource	*res;
673 	struct clk *clk;
674 	int ret, i;
675 
676 	cdata = of_device_get_match_data(&pdev->dev);
677 	if (!cdata) {
678 		dev_err(&pdev->dev, "device match data not found\n");
679 		return -ENODEV;
680 	}
681 
682 	tdma = devm_kzalloc(&pdev->dev, sizeof(*tdma) + cdata->nr_channels *
683 			    sizeof(struct tegra_adma_chan), GFP_KERNEL);
684 	if (!tdma)
685 		return -ENOMEM;
686 
687 	tdma->dev = &pdev->dev;
688 	tdma->nr_channels = cdata->nr_channels;
689 	platform_set_drvdata(pdev, tdma);
690 
691 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
692 	tdma->base_addr = devm_ioremap_resource(&pdev->dev, res);
693 	if (IS_ERR(tdma->base_addr))
694 		return PTR_ERR(tdma->base_addr);
695 
696 	ret = pm_clk_create(&pdev->dev);
697 	if (ret)
698 		return ret;
699 
700 	clk = clk_get(&pdev->dev, "d_audio");
701 	if (IS_ERR(clk)) {
702 		dev_err(&pdev->dev, "ADMA clock not found\n");
703 		ret = PTR_ERR(clk);
704 		goto clk_destroy;
705 	}
706 
707 	ret = pm_clk_add_clk(&pdev->dev, clk);
708 	if (ret) {
709 		clk_put(clk);
710 		goto clk_destroy;
711 	}
712 
713 	pm_runtime_enable(&pdev->dev);
714 
715 	ret = pm_runtime_get_sync(&pdev->dev);
716 	if (ret < 0)
717 		goto rpm_disable;
718 
719 	ret = tegra_adma_init(tdma);
720 	if (ret)
721 		goto rpm_put;
722 
723 	INIT_LIST_HEAD(&tdma->dma_dev.channels);
724 	for (i = 0; i < tdma->nr_channels; i++) {
725 		struct tegra_adma_chan *tdc = &tdma->channels[i];
726 
727 		tdc->chan_addr = tdma->base_addr + ADMA_CH_REG_OFFSET(i);
728 
729 		tdc->irq = of_irq_get(pdev->dev.of_node, i);
730 		if (tdc->irq < 0) {
731 			ret = tdc->irq;
732 			goto irq_dispose;
733 		}
734 
735 		vchan_init(&tdc->vc, &tdma->dma_dev);
736 		tdc->vc.desc_free = tegra_adma_desc_free;
737 		tdc->tdma = tdma;
738 	}
739 
740 	dma_cap_set(DMA_SLAVE, tdma->dma_dev.cap_mask);
741 	dma_cap_set(DMA_PRIVATE, tdma->dma_dev.cap_mask);
742 	dma_cap_set(DMA_CYCLIC, tdma->dma_dev.cap_mask);
743 
744 	tdma->dma_dev.dev = &pdev->dev;
745 	tdma->dma_dev.device_alloc_chan_resources =
746 					tegra_adma_alloc_chan_resources;
747 	tdma->dma_dev.device_free_chan_resources =
748 					tegra_adma_free_chan_resources;
749 	tdma->dma_dev.device_issue_pending = tegra_adma_issue_pending;
750 	tdma->dma_dev.device_prep_dma_cyclic = tegra_adma_prep_dma_cyclic;
751 	tdma->dma_dev.device_config = tegra_adma_slave_config;
752 	tdma->dma_dev.device_tx_status = tegra_adma_tx_status;
753 	tdma->dma_dev.device_terminate_all = tegra_adma_terminate_all;
754 	tdma->dma_dev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
755 	tdma->dma_dev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
756 	tdma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
757 	tdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
758 
759 	ret = dma_async_device_register(&tdma->dma_dev);
760 	if (ret < 0) {
761 		dev_err(&pdev->dev, "ADMA registration failed: %d\n", ret);
762 		goto irq_dispose;
763 	}
764 
765 	ret = of_dma_controller_register(pdev->dev.of_node,
766 					 tegra_dma_of_xlate, tdma);
767 	if (ret < 0) {
768 		dev_err(&pdev->dev, "ADMA OF registration failed %d\n", ret);
769 		goto dma_remove;
770 	}
771 
772 	pm_runtime_put(&pdev->dev);
773 
774 	dev_info(&pdev->dev, "Tegra210 ADMA driver registered %d channels\n",
775 		 tdma->nr_channels);
776 
777 	return 0;
778 
779 dma_remove:
780 	dma_async_device_unregister(&tdma->dma_dev);
781 irq_dispose:
782 	while (--i >= 0)
783 		irq_dispose_mapping(tdma->channels[i].irq);
784 rpm_put:
785 	pm_runtime_put_sync(&pdev->dev);
786 rpm_disable:
787 	pm_runtime_disable(&pdev->dev);
788 clk_destroy:
789 	pm_clk_destroy(&pdev->dev);
790 
791 	return ret;
792 }
793 
794 static int tegra_adma_remove(struct platform_device *pdev)
795 {
796 	struct tegra_adma *tdma = platform_get_drvdata(pdev);
797 	int i;
798 
799 	dma_async_device_unregister(&tdma->dma_dev);
800 
801 	for (i = 0; i < tdma->nr_channels; ++i)
802 		irq_dispose_mapping(tdma->channels[i].irq);
803 
804 	pm_runtime_put_sync(&pdev->dev);
805 	pm_runtime_disable(&pdev->dev);
806 	pm_clk_destroy(&pdev->dev);
807 
808 	return 0;
809 }
810 
811 #ifdef CONFIG_PM_SLEEP
812 static int tegra_adma_pm_suspend(struct device *dev)
813 {
814 	return pm_runtime_suspended(dev) == false;
815 }
816 #endif
817 
818 static const struct dev_pm_ops tegra_adma_dev_pm_ops = {
819 	SET_RUNTIME_PM_OPS(tegra_adma_runtime_suspend,
820 			   tegra_adma_runtime_resume, NULL)
821 	SET_SYSTEM_SLEEP_PM_OPS(tegra_adma_pm_suspend, NULL)
822 };
823 
824 static struct platform_driver tegra_admac_driver = {
825 	.driver = {
826 		.name	= "tegra-adma",
827 		.pm	= &tegra_adma_dev_pm_ops,
828 		.of_match_table = tegra_adma_of_match,
829 	},
830 	.probe		= tegra_adma_probe,
831 	.remove		= tegra_adma_remove,
832 };
833 
834 module_platform_driver(tegra_admac_driver);
835 
836 MODULE_ALIAS("platform:tegra210-adma");
837 MODULE_DESCRIPTION("NVIDIA Tegra ADMA driver");
838 MODULE_AUTHOR("Dara Ramesh <dramesh@nvidia.com>");
839 MODULE_AUTHOR("Jon Hunter <jonathanh@nvidia.com>");
840 MODULE_LICENSE("GPL v2");
841