xref: /linux/drivers/dma/imx-dma.c (revision 5e3992fe72748ed3892be876f09d4d990548b7af)
1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // drivers/dma/imx-dma.c
4 //
5 // This file contains a driver for the Freescale i.MX DMA engine
6 // found on i.MX1/21/27
7 //
8 // Copyright 2010 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
9 // Copyright 2012 Javier Martin, Vista Silicon <javier.martin@vista-silicon.com>
10 
11 #include <linux/err.h>
12 #include <linux/init.h>
13 #include <linux/types.h>
14 #include <linux/mm.h>
15 #include <linux/interrupt.h>
16 #include <linux/spinlock.h>
17 #include <linux/device.h>
18 #include <linux/dma-mapping.h>
19 #include <linux/slab.h>
20 #include <linux/platform_device.h>
21 #include <linux/clk.h>
22 #include <linux/dmaengine.h>
23 #include <linux/module.h>
24 #include <linux/of_device.h>
25 #include <linux/of_dma.h>
26 
27 #include <asm/irq.h>
28 #include <linux/dma/imx-dma.h>
29 
30 #include "dmaengine.h"
31 #define IMXDMA_MAX_CHAN_DESCRIPTORS	16
32 #define IMX_DMA_CHANNELS  16
33 
34 #define IMX_DMA_2D_SLOTS	2
35 #define IMX_DMA_2D_SLOT_A	0
36 #define IMX_DMA_2D_SLOT_B	1
37 
38 #define IMX_DMA_LENGTH_LOOP	((unsigned int)-1)
39 #define IMX_DMA_MEMSIZE_32	(0 << 4)
40 #define IMX_DMA_MEMSIZE_8	(1 << 4)
41 #define IMX_DMA_MEMSIZE_16	(2 << 4)
42 #define IMX_DMA_TYPE_LINEAR	(0 << 10)
43 #define IMX_DMA_TYPE_2D		(1 << 10)
44 #define IMX_DMA_TYPE_FIFO	(2 << 10)
45 
46 #define IMX_DMA_ERR_BURST     (1 << 0)
47 #define IMX_DMA_ERR_REQUEST   (1 << 1)
48 #define IMX_DMA_ERR_TRANSFER  (1 << 2)
49 #define IMX_DMA_ERR_BUFFER    (1 << 3)
50 #define IMX_DMA_ERR_TIMEOUT   (1 << 4)
51 
52 #define DMA_DCR     0x00		/* Control Register */
53 #define DMA_DISR    0x04		/* Interrupt status Register */
54 #define DMA_DIMR    0x08		/* Interrupt mask Register */
55 #define DMA_DBTOSR  0x0c		/* Burst timeout status Register */
56 #define DMA_DRTOSR  0x10		/* Request timeout Register */
57 #define DMA_DSESR   0x14		/* Transfer Error Status Register */
58 #define DMA_DBOSR   0x18		/* Buffer overflow status Register */
59 #define DMA_DBTOCR  0x1c		/* Burst timeout control Register */
60 #define DMA_WSRA    0x40		/* W-Size Register A */
61 #define DMA_XSRA    0x44		/* X-Size Register A */
62 #define DMA_YSRA    0x48		/* Y-Size Register A */
63 #define DMA_WSRB    0x4c		/* W-Size Register B */
64 #define DMA_XSRB    0x50		/* X-Size Register B */
65 #define DMA_YSRB    0x54		/* Y-Size Register B */
66 #define DMA_SAR(x)  (0x80 + ((x) << 6))	/* Source Address Registers */
67 #define DMA_DAR(x)  (0x84 + ((x) << 6))	/* Destination Address Registers */
68 #define DMA_CNTR(x) (0x88 + ((x) << 6))	/* Count Registers */
69 #define DMA_CCR(x)  (0x8c + ((x) << 6))	/* Control Registers */
70 #define DMA_RSSR(x) (0x90 + ((x) << 6))	/* Request source select Registers */
71 #define DMA_BLR(x)  (0x94 + ((x) << 6))	/* Burst length Registers */
72 #define DMA_RTOR(x) (0x98 + ((x) << 6))	/* Request timeout Registers */
73 #define DMA_BUCR(x) (0x98 + ((x) << 6))	/* Bus Utilization Registers */
74 #define DMA_CCNR(x) (0x9C + ((x) << 6))	/* Channel counter Registers */
75 
76 #define DCR_DRST           (1<<1)
77 #define DCR_DEN            (1<<0)
78 #define DBTOCR_EN          (1<<15)
79 #define DBTOCR_CNT(x)      ((x) & 0x7fff)
80 #define CNTR_CNT(x)        ((x) & 0xffffff)
81 #define CCR_ACRPT          (1<<14)
82 #define CCR_DMOD_LINEAR    (0x0 << 12)
83 #define CCR_DMOD_2D        (0x1 << 12)
84 #define CCR_DMOD_FIFO      (0x2 << 12)
85 #define CCR_DMOD_EOBFIFO   (0x3 << 12)
86 #define CCR_SMOD_LINEAR    (0x0 << 10)
87 #define CCR_SMOD_2D        (0x1 << 10)
88 #define CCR_SMOD_FIFO      (0x2 << 10)
89 #define CCR_SMOD_EOBFIFO   (0x3 << 10)
90 #define CCR_MDIR_DEC       (1<<9)
91 #define CCR_MSEL_B         (1<<8)
92 #define CCR_DSIZ_32        (0x0 << 6)
93 #define CCR_DSIZ_8         (0x1 << 6)
94 #define CCR_DSIZ_16        (0x2 << 6)
95 #define CCR_SSIZ_32        (0x0 << 4)
96 #define CCR_SSIZ_8         (0x1 << 4)
97 #define CCR_SSIZ_16        (0x2 << 4)
98 #define CCR_REN            (1<<3)
99 #define CCR_RPT            (1<<2)
100 #define CCR_FRC            (1<<1)
101 #define CCR_CEN            (1<<0)
102 #define RTOR_EN            (1<<15)
103 #define RTOR_CLK           (1<<14)
104 #define RTOR_PSC           (1<<13)
105 
106 enum  imxdma_prep_type {
107 	IMXDMA_DESC_MEMCPY,
108 	IMXDMA_DESC_INTERLEAVED,
109 	IMXDMA_DESC_SLAVE_SG,
110 	IMXDMA_DESC_CYCLIC,
111 };
112 
113 struct imx_dma_2d_config {
114 	u16		xsr;
115 	u16		ysr;
116 	u16		wsr;
117 	int		count;
118 };
119 
120 struct imxdma_desc {
121 	struct list_head		node;
122 	struct dma_async_tx_descriptor	desc;
123 	enum dma_status			status;
124 	dma_addr_t			src;
125 	dma_addr_t			dest;
126 	size_t				len;
127 	enum dma_transfer_direction	direction;
128 	enum imxdma_prep_type		type;
129 	/* For memcpy and interleaved */
130 	unsigned int			config_port;
131 	unsigned int			config_mem;
132 	/* For interleaved transfers */
133 	unsigned int			x;
134 	unsigned int			y;
135 	unsigned int			w;
136 	/* For slave sg and cyclic */
137 	struct scatterlist		*sg;
138 	unsigned int			sgcount;
139 };
140 
141 struct imxdma_channel {
142 	int				hw_chaining;
143 	struct timer_list		watchdog;
144 	struct imxdma_engine		*imxdma;
145 	unsigned int			channel;
146 
147 	struct tasklet_struct		dma_tasklet;
148 	struct list_head		ld_free;
149 	struct list_head		ld_queue;
150 	struct list_head		ld_active;
151 	int				descs_allocated;
152 	enum dma_slave_buswidth		word_size;
153 	dma_addr_t			per_address;
154 	u32				watermark_level;
155 	struct dma_chan			chan;
156 	struct dma_async_tx_descriptor	desc;
157 	enum dma_status			status;
158 	int				dma_request;
159 	struct scatterlist		*sg_list;
160 	u32				ccr_from_device;
161 	u32				ccr_to_device;
162 	bool				enabled_2d;
163 	int				slot_2d;
164 	unsigned int			irq;
165 	struct dma_slave_config		config;
166 };
167 
168 enum imx_dma_type {
169 	IMX1_DMA,
170 	IMX21_DMA,
171 	IMX27_DMA,
172 };
173 
174 struct imxdma_engine {
175 	struct device			*dev;
176 	struct dma_device		dma_device;
177 	void __iomem			*base;
178 	struct clk			*dma_ahb;
179 	struct clk			*dma_ipg;
180 	spinlock_t			lock;
181 	struct imx_dma_2d_config	slots_2d[IMX_DMA_2D_SLOTS];
182 	struct imxdma_channel		channel[IMX_DMA_CHANNELS];
183 	enum imx_dma_type		devtype;
184 	unsigned int			irq;
185 	unsigned int			irq_err;
186 
187 };
188 
189 struct imxdma_filter_data {
190 	struct imxdma_engine	*imxdma;
191 	int			 request;
192 };
193 
194 static const struct of_device_id imx_dma_of_dev_id[] = {
195 	{
196 		.compatible = "fsl,imx1-dma", .data = (const void *)IMX1_DMA,
197 	}, {
198 		.compatible = "fsl,imx21-dma", .data = (const void *)IMX21_DMA,
199 	}, {
200 		.compatible = "fsl,imx27-dma", .data = (const void *)IMX27_DMA,
201 	}, {
202 		/* sentinel */
203 	}
204 };
205 MODULE_DEVICE_TABLE(of, imx_dma_of_dev_id);
206 
207 static inline int is_imx1_dma(struct imxdma_engine *imxdma)
208 {
209 	return imxdma->devtype == IMX1_DMA;
210 }
211 
212 static inline int is_imx27_dma(struct imxdma_engine *imxdma)
213 {
214 	return imxdma->devtype == IMX27_DMA;
215 }
216 
217 static struct imxdma_channel *to_imxdma_chan(struct dma_chan *chan)
218 {
219 	return container_of(chan, struct imxdma_channel, chan);
220 }
221 
222 static inline bool imxdma_chan_is_doing_cyclic(struct imxdma_channel *imxdmac)
223 {
224 	struct imxdma_desc *desc;
225 
226 	if (!list_empty(&imxdmac->ld_active)) {
227 		desc = list_first_entry(&imxdmac->ld_active, struct imxdma_desc,
228 					node);
229 		if (desc->type == IMXDMA_DESC_CYCLIC)
230 			return true;
231 	}
232 	return false;
233 }
234 
235 
236 
237 static void imx_dmav1_writel(struct imxdma_engine *imxdma, unsigned val,
238 			     unsigned offset)
239 {
240 	__raw_writel(val, imxdma->base + offset);
241 }
242 
243 static unsigned imx_dmav1_readl(struct imxdma_engine *imxdma, unsigned offset)
244 {
245 	return __raw_readl(imxdma->base + offset);
246 }
247 
248 static int imxdma_hw_chain(struct imxdma_channel *imxdmac)
249 {
250 	struct imxdma_engine *imxdma = imxdmac->imxdma;
251 
252 	if (is_imx27_dma(imxdma))
253 		return imxdmac->hw_chaining;
254 	else
255 		return 0;
256 }
257 
258 /*
259  * imxdma_sg_next - prepare next chunk for scatter-gather DMA emulation
260  */
261 static inline void imxdma_sg_next(struct imxdma_desc *d)
262 {
263 	struct imxdma_channel *imxdmac = to_imxdma_chan(d->desc.chan);
264 	struct imxdma_engine *imxdma = imxdmac->imxdma;
265 	struct scatterlist *sg = d->sg;
266 	size_t now;
267 
268 	now = min_t(size_t, d->len, sg_dma_len(sg));
269 	if (d->len != IMX_DMA_LENGTH_LOOP)
270 		d->len -= now;
271 
272 	if (d->direction == DMA_DEV_TO_MEM)
273 		imx_dmav1_writel(imxdma, sg->dma_address,
274 				 DMA_DAR(imxdmac->channel));
275 	else
276 		imx_dmav1_writel(imxdma, sg->dma_address,
277 				 DMA_SAR(imxdmac->channel));
278 
279 	imx_dmav1_writel(imxdma, now, DMA_CNTR(imxdmac->channel));
280 
281 	dev_dbg(imxdma->dev, " %s channel: %d dst 0x%08x, src 0x%08x, "
282 		"size 0x%08x\n", __func__, imxdmac->channel,
283 		 imx_dmav1_readl(imxdma, DMA_DAR(imxdmac->channel)),
284 		 imx_dmav1_readl(imxdma, DMA_SAR(imxdmac->channel)),
285 		 imx_dmav1_readl(imxdma, DMA_CNTR(imxdmac->channel)));
286 }
287 
288 static void imxdma_enable_hw(struct imxdma_desc *d)
289 {
290 	struct imxdma_channel *imxdmac = to_imxdma_chan(d->desc.chan);
291 	struct imxdma_engine *imxdma = imxdmac->imxdma;
292 	int channel = imxdmac->channel;
293 	unsigned long flags;
294 
295 	dev_dbg(imxdma->dev, "%s channel %d\n", __func__, channel);
296 
297 	local_irq_save(flags);
298 
299 	imx_dmav1_writel(imxdma, 1 << channel, DMA_DISR);
300 	imx_dmav1_writel(imxdma, imx_dmav1_readl(imxdma, DMA_DIMR) &
301 			 ~(1 << channel), DMA_DIMR);
302 	imx_dmav1_writel(imxdma, imx_dmav1_readl(imxdma, DMA_CCR(channel)) |
303 			 CCR_CEN | CCR_ACRPT, DMA_CCR(channel));
304 
305 	if (!is_imx1_dma(imxdma) &&
306 			d->sg && imxdma_hw_chain(imxdmac)) {
307 		d->sg = sg_next(d->sg);
308 		if (d->sg) {
309 			u32 tmp;
310 			imxdma_sg_next(d);
311 			tmp = imx_dmav1_readl(imxdma, DMA_CCR(channel));
312 			imx_dmav1_writel(imxdma, tmp | CCR_RPT | CCR_ACRPT,
313 					 DMA_CCR(channel));
314 		}
315 	}
316 
317 	local_irq_restore(flags);
318 }
319 
320 static void imxdma_disable_hw(struct imxdma_channel *imxdmac)
321 {
322 	struct imxdma_engine *imxdma = imxdmac->imxdma;
323 	int channel = imxdmac->channel;
324 	unsigned long flags;
325 
326 	dev_dbg(imxdma->dev, "%s channel %d\n", __func__, channel);
327 
328 	if (imxdma_hw_chain(imxdmac))
329 		del_timer(&imxdmac->watchdog);
330 
331 	local_irq_save(flags);
332 	imx_dmav1_writel(imxdma, imx_dmav1_readl(imxdma, DMA_DIMR) |
333 			 (1 << channel), DMA_DIMR);
334 	imx_dmav1_writel(imxdma, imx_dmav1_readl(imxdma, DMA_CCR(channel)) &
335 			 ~CCR_CEN, DMA_CCR(channel));
336 	imx_dmav1_writel(imxdma, 1 << channel, DMA_DISR);
337 	local_irq_restore(flags);
338 }
339 
340 static void imxdma_watchdog(struct timer_list *t)
341 {
342 	struct imxdma_channel *imxdmac = from_timer(imxdmac, t, watchdog);
343 	struct imxdma_engine *imxdma = imxdmac->imxdma;
344 	int channel = imxdmac->channel;
345 
346 	imx_dmav1_writel(imxdma, 0, DMA_CCR(channel));
347 
348 	/* Tasklet watchdog error handler */
349 	tasklet_schedule(&imxdmac->dma_tasklet);
350 	dev_dbg(imxdma->dev, "channel %d: watchdog timeout!\n",
351 		imxdmac->channel);
352 }
353 
354 static irqreturn_t imxdma_err_handler(int irq, void *dev_id)
355 {
356 	struct imxdma_engine *imxdma = dev_id;
357 	unsigned int err_mask;
358 	int i, disr;
359 	int errcode;
360 
361 	disr = imx_dmav1_readl(imxdma, DMA_DISR);
362 
363 	err_mask = imx_dmav1_readl(imxdma, DMA_DBTOSR) |
364 		   imx_dmav1_readl(imxdma, DMA_DRTOSR) |
365 		   imx_dmav1_readl(imxdma, DMA_DSESR)  |
366 		   imx_dmav1_readl(imxdma, DMA_DBOSR);
367 
368 	if (!err_mask)
369 		return IRQ_HANDLED;
370 
371 	imx_dmav1_writel(imxdma, disr & err_mask, DMA_DISR);
372 
373 	for (i = 0; i < IMX_DMA_CHANNELS; i++) {
374 		if (!(err_mask & (1 << i)))
375 			continue;
376 		errcode = 0;
377 
378 		if (imx_dmav1_readl(imxdma, DMA_DBTOSR) & (1 << i)) {
379 			imx_dmav1_writel(imxdma, 1 << i, DMA_DBTOSR);
380 			errcode |= IMX_DMA_ERR_BURST;
381 		}
382 		if (imx_dmav1_readl(imxdma, DMA_DRTOSR) & (1 << i)) {
383 			imx_dmav1_writel(imxdma, 1 << i, DMA_DRTOSR);
384 			errcode |= IMX_DMA_ERR_REQUEST;
385 		}
386 		if (imx_dmav1_readl(imxdma, DMA_DSESR) & (1 << i)) {
387 			imx_dmav1_writel(imxdma, 1 << i, DMA_DSESR);
388 			errcode |= IMX_DMA_ERR_TRANSFER;
389 		}
390 		if (imx_dmav1_readl(imxdma, DMA_DBOSR) & (1 << i)) {
391 			imx_dmav1_writel(imxdma, 1 << i, DMA_DBOSR);
392 			errcode |= IMX_DMA_ERR_BUFFER;
393 		}
394 		/* Tasklet error handler */
395 		tasklet_schedule(&imxdma->channel[i].dma_tasklet);
396 
397 		dev_warn(imxdma->dev,
398 			 "DMA timeout on channel %d -%s%s%s%s\n", i,
399 			 errcode & IMX_DMA_ERR_BURST ?    " burst" : "",
400 			 errcode & IMX_DMA_ERR_REQUEST ?  " request" : "",
401 			 errcode & IMX_DMA_ERR_TRANSFER ? " transfer" : "",
402 			 errcode & IMX_DMA_ERR_BUFFER ?   " buffer" : "");
403 	}
404 	return IRQ_HANDLED;
405 }
406 
407 static void dma_irq_handle_channel(struct imxdma_channel *imxdmac)
408 {
409 	struct imxdma_engine *imxdma = imxdmac->imxdma;
410 	int chno = imxdmac->channel;
411 	struct imxdma_desc *desc;
412 	unsigned long flags;
413 
414 	spin_lock_irqsave(&imxdma->lock, flags);
415 	if (list_empty(&imxdmac->ld_active)) {
416 		spin_unlock_irqrestore(&imxdma->lock, flags);
417 		goto out;
418 	}
419 
420 	desc = list_first_entry(&imxdmac->ld_active,
421 				struct imxdma_desc,
422 				node);
423 	spin_unlock_irqrestore(&imxdma->lock, flags);
424 
425 	if (desc->sg) {
426 		u32 tmp;
427 		desc->sg = sg_next(desc->sg);
428 
429 		if (desc->sg) {
430 			imxdma_sg_next(desc);
431 
432 			tmp = imx_dmav1_readl(imxdma, DMA_CCR(chno));
433 
434 			if (imxdma_hw_chain(imxdmac)) {
435 				/* FIXME: The timeout should probably be
436 				 * configurable
437 				 */
438 				mod_timer(&imxdmac->watchdog,
439 					jiffies + msecs_to_jiffies(500));
440 
441 				tmp |= CCR_CEN | CCR_RPT | CCR_ACRPT;
442 				imx_dmav1_writel(imxdma, tmp, DMA_CCR(chno));
443 			} else {
444 				imx_dmav1_writel(imxdma, tmp & ~CCR_CEN,
445 						 DMA_CCR(chno));
446 				tmp |= CCR_CEN;
447 			}
448 
449 			imx_dmav1_writel(imxdma, tmp, DMA_CCR(chno));
450 
451 			if (imxdma_chan_is_doing_cyclic(imxdmac))
452 				/* Tasklet progression */
453 				tasklet_schedule(&imxdmac->dma_tasklet);
454 
455 			return;
456 		}
457 
458 		if (imxdma_hw_chain(imxdmac)) {
459 			del_timer(&imxdmac->watchdog);
460 			return;
461 		}
462 	}
463 
464 out:
465 	imx_dmav1_writel(imxdma, 0, DMA_CCR(chno));
466 	/* Tasklet irq */
467 	tasklet_schedule(&imxdmac->dma_tasklet);
468 }
469 
470 static irqreturn_t dma_irq_handler(int irq, void *dev_id)
471 {
472 	struct imxdma_engine *imxdma = dev_id;
473 	int i, disr;
474 
475 	if (!is_imx1_dma(imxdma))
476 		imxdma_err_handler(irq, dev_id);
477 
478 	disr = imx_dmav1_readl(imxdma, DMA_DISR);
479 
480 	dev_dbg(imxdma->dev, "%s called, disr=0x%08x\n", __func__, disr);
481 
482 	imx_dmav1_writel(imxdma, disr, DMA_DISR);
483 	for (i = 0; i < IMX_DMA_CHANNELS; i++) {
484 		if (disr & (1 << i))
485 			dma_irq_handle_channel(&imxdma->channel[i]);
486 	}
487 
488 	return IRQ_HANDLED;
489 }
490 
491 static int imxdma_xfer_desc(struct imxdma_desc *d)
492 {
493 	struct imxdma_channel *imxdmac = to_imxdma_chan(d->desc.chan);
494 	struct imxdma_engine *imxdma = imxdmac->imxdma;
495 	int slot = -1;
496 	int i;
497 
498 	/* Configure and enable */
499 	switch (d->type) {
500 	case IMXDMA_DESC_INTERLEAVED:
501 		/* Try to get a free 2D slot */
502 		for (i = 0; i < IMX_DMA_2D_SLOTS; i++) {
503 			if ((imxdma->slots_2d[i].count > 0) &&
504 			((imxdma->slots_2d[i].xsr != d->x) ||
505 			(imxdma->slots_2d[i].ysr != d->y) ||
506 			(imxdma->slots_2d[i].wsr != d->w)))
507 				continue;
508 			slot = i;
509 			break;
510 		}
511 		if (slot < 0)
512 			return -EBUSY;
513 
514 		imxdma->slots_2d[slot].xsr = d->x;
515 		imxdma->slots_2d[slot].ysr = d->y;
516 		imxdma->slots_2d[slot].wsr = d->w;
517 		imxdma->slots_2d[slot].count++;
518 
519 		imxdmac->slot_2d = slot;
520 		imxdmac->enabled_2d = true;
521 
522 		if (slot == IMX_DMA_2D_SLOT_A) {
523 			d->config_mem &= ~CCR_MSEL_B;
524 			d->config_port &= ~CCR_MSEL_B;
525 			imx_dmav1_writel(imxdma, d->x, DMA_XSRA);
526 			imx_dmav1_writel(imxdma, d->y, DMA_YSRA);
527 			imx_dmav1_writel(imxdma, d->w, DMA_WSRA);
528 		} else {
529 			d->config_mem |= CCR_MSEL_B;
530 			d->config_port |= CCR_MSEL_B;
531 			imx_dmav1_writel(imxdma, d->x, DMA_XSRB);
532 			imx_dmav1_writel(imxdma, d->y, DMA_YSRB);
533 			imx_dmav1_writel(imxdma, d->w, DMA_WSRB);
534 		}
535 		/*
536 		 * We fall-through here intentionally, since a 2D transfer is
537 		 * similar to MEMCPY just adding the 2D slot configuration.
538 		 */
539 		fallthrough;
540 	case IMXDMA_DESC_MEMCPY:
541 		imx_dmav1_writel(imxdma, d->src, DMA_SAR(imxdmac->channel));
542 		imx_dmav1_writel(imxdma, d->dest, DMA_DAR(imxdmac->channel));
543 		imx_dmav1_writel(imxdma, d->config_mem | (d->config_port << 2),
544 			 DMA_CCR(imxdmac->channel));
545 
546 		imx_dmav1_writel(imxdma, d->len, DMA_CNTR(imxdmac->channel));
547 
548 		dev_dbg(imxdma->dev,
549 			"%s channel: %d dest=0x%08llx src=0x%08llx dma_length=%zu\n",
550 			__func__, imxdmac->channel,
551 			(unsigned long long)d->dest,
552 			(unsigned long long)d->src, d->len);
553 
554 		break;
555 	/* Cyclic transfer is the same as slave_sg with special sg configuration. */
556 	case IMXDMA_DESC_CYCLIC:
557 	case IMXDMA_DESC_SLAVE_SG:
558 		if (d->direction == DMA_DEV_TO_MEM) {
559 			imx_dmav1_writel(imxdma, imxdmac->per_address,
560 					 DMA_SAR(imxdmac->channel));
561 			imx_dmav1_writel(imxdma, imxdmac->ccr_from_device,
562 					 DMA_CCR(imxdmac->channel));
563 
564 			dev_dbg(imxdma->dev,
565 				"%s channel: %d sg=%p sgcount=%d total length=%zu dev_addr=0x%08llx (dev2mem)\n",
566 				__func__, imxdmac->channel,
567 				d->sg, d->sgcount, d->len,
568 				(unsigned long long)imxdmac->per_address);
569 		} else if (d->direction == DMA_MEM_TO_DEV) {
570 			imx_dmav1_writel(imxdma, imxdmac->per_address,
571 					 DMA_DAR(imxdmac->channel));
572 			imx_dmav1_writel(imxdma, imxdmac->ccr_to_device,
573 					 DMA_CCR(imxdmac->channel));
574 
575 			dev_dbg(imxdma->dev,
576 				"%s channel: %d sg=%p sgcount=%d total length=%zu dev_addr=0x%08llx (mem2dev)\n",
577 				__func__, imxdmac->channel,
578 				d->sg, d->sgcount, d->len,
579 				(unsigned long long)imxdmac->per_address);
580 		} else {
581 			dev_err(imxdma->dev, "%s channel: %d bad dma mode\n",
582 				__func__, imxdmac->channel);
583 			return -EINVAL;
584 		}
585 
586 		imxdma_sg_next(d);
587 
588 		break;
589 	default:
590 		return -EINVAL;
591 	}
592 	imxdma_enable_hw(d);
593 	return 0;
594 }
595 
596 static void imxdma_tasklet(struct tasklet_struct *t)
597 {
598 	struct imxdma_channel *imxdmac = from_tasklet(imxdmac, t, dma_tasklet);
599 	struct imxdma_engine *imxdma = imxdmac->imxdma;
600 	struct imxdma_desc *desc, *next_desc;
601 	unsigned long flags;
602 
603 	spin_lock_irqsave(&imxdma->lock, flags);
604 
605 	if (list_empty(&imxdmac->ld_active)) {
606 		/* Someone might have called terminate all */
607 		spin_unlock_irqrestore(&imxdma->lock, flags);
608 		return;
609 	}
610 	desc = list_first_entry(&imxdmac->ld_active, struct imxdma_desc, node);
611 
612 	/* If we are dealing with a cyclic descriptor, keep it on ld_active
613 	 * and dont mark the descriptor as complete.
614 	 * Only in non-cyclic cases it would be marked as complete
615 	 */
616 	if (imxdma_chan_is_doing_cyclic(imxdmac))
617 		goto out;
618 	else
619 		dma_cookie_complete(&desc->desc);
620 
621 	/* Free 2D slot if it was an interleaved transfer */
622 	if (imxdmac->enabled_2d) {
623 		imxdma->slots_2d[imxdmac->slot_2d].count--;
624 		imxdmac->enabled_2d = false;
625 	}
626 
627 	list_move_tail(imxdmac->ld_active.next, &imxdmac->ld_free);
628 
629 	if (!list_empty(&imxdmac->ld_queue)) {
630 		next_desc = list_first_entry(&imxdmac->ld_queue,
631 					     struct imxdma_desc, node);
632 		list_move_tail(imxdmac->ld_queue.next, &imxdmac->ld_active);
633 		if (imxdma_xfer_desc(next_desc) < 0)
634 			dev_warn(imxdma->dev, "%s: channel: %d couldn't xfer desc\n",
635 				 __func__, imxdmac->channel);
636 	}
637 out:
638 	spin_unlock_irqrestore(&imxdma->lock, flags);
639 
640 	dmaengine_desc_get_callback_invoke(&desc->desc, NULL);
641 }
642 
643 static int imxdma_terminate_all(struct dma_chan *chan)
644 {
645 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
646 	struct imxdma_engine *imxdma = imxdmac->imxdma;
647 	unsigned long flags;
648 
649 	imxdma_disable_hw(imxdmac);
650 
651 	spin_lock_irqsave(&imxdma->lock, flags);
652 	list_splice_tail_init(&imxdmac->ld_active, &imxdmac->ld_free);
653 	list_splice_tail_init(&imxdmac->ld_queue, &imxdmac->ld_free);
654 	spin_unlock_irqrestore(&imxdma->lock, flags);
655 	return 0;
656 }
657 
658 static int imxdma_config_write(struct dma_chan *chan,
659 			       struct dma_slave_config *dmaengine_cfg,
660 			       enum dma_transfer_direction direction)
661 {
662 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
663 	struct imxdma_engine *imxdma = imxdmac->imxdma;
664 	unsigned int mode = 0;
665 
666 	if (direction == DMA_DEV_TO_MEM) {
667 		imxdmac->per_address = dmaengine_cfg->src_addr;
668 		imxdmac->watermark_level = dmaengine_cfg->src_maxburst;
669 		imxdmac->word_size = dmaengine_cfg->src_addr_width;
670 	} else {
671 		imxdmac->per_address = dmaengine_cfg->dst_addr;
672 		imxdmac->watermark_level = dmaengine_cfg->dst_maxburst;
673 		imxdmac->word_size = dmaengine_cfg->dst_addr_width;
674 	}
675 
676 	switch (imxdmac->word_size) {
677 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
678 		mode = IMX_DMA_MEMSIZE_8;
679 		break;
680 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
681 		mode = IMX_DMA_MEMSIZE_16;
682 		break;
683 	default:
684 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
685 		mode = IMX_DMA_MEMSIZE_32;
686 		break;
687 	}
688 
689 	imxdmac->hw_chaining = 0;
690 
691 	imxdmac->ccr_from_device = (mode | IMX_DMA_TYPE_FIFO) |
692 		((IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR) << 2) |
693 		CCR_REN;
694 	imxdmac->ccr_to_device =
695 		(IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR) |
696 		((mode | IMX_DMA_TYPE_FIFO) << 2) | CCR_REN;
697 	imx_dmav1_writel(imxdma, imxdmac->dma_request,
698 			 DMA_RSSR(imxdmac->channel));
699 
700 	/* Set burst length */
701 	imx_dmav1_writel(imxdma, imxdmac->watermark_level *
702 			 imxdmac->word_size, DMA_BLR(imxdmac->channel));
703 
704 	return 0;
705 }
706 
707 static int imxdma_config(struct dma_chan *chan,
708 			 struct dma_slave_config *dmaengine_cfg)
709 {
710 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
711 
712 	memcpy(&imxdmac->config, dmaengine_cfg, sizeof(*dmaengine_cfg));
713 
714 	return 0;
715 }
716 
717 static enum dma_status imxdma_tx_status(struct dma_chan *chan,
718 					    dma_cookie_t cookie,
719 					    struct dma_tx_state *txstate)
720 {
721 	return dma_cookie_status(chan, cookie, txstate);
722 }
723 
724 static dma_cookie_t imxdma_tx_submit(struct dma_async_tx_descriptor *tx)
725 {
726 	struct imxdma_channel *imxdmac = to_imxdma_chan(tx->chan);
727 	struct imxdma_engine *imxdma = imxdmac->imxdma;
728 	dma_cookie_t cookie;
729 	unsigned long flags;
730 
731 	spin_lock_irqsave(&imxdma->lock, flags);
732 	list_move_tail(imxdmac->ld_free.next, &imxdmac->ld_queue);
733 	cookie = dma_cookie_assign(tx);
734 	spin_unlock_irqrestore(&imxdma->lock, flags);
735 
736 	return cookie;
737 }
738 
739 static int imxdma_alloc_chan_resources(struct dma_chan *chan)
740 {
741 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
742 	struct imx_dma_data *data = chan->private;
743 
744 	if (data != NULL)
745 		imxdmac->dma_request = data->dma_request;
746 
747 	while (imxdmac->descs_allocated < IMXDMA_MAX_CHAN_DESCRIPTORS) {
748 		struct imxdma_desc *desc;
749 
750 		desc = kzalloc(sizeof(*desc), GFP_KERNEL);
751 		if (!desc)
752 			break;
753 		dma_async_tx_descriptor_init(&desc->desc, chan);
754 		desc->desc.tx_submit = imxdma_tx_submit;
755 		/* txd.flags will be overwritten in prep funcs */
756 		desc->desc.flags = DMA_CTRL_ACK;
757 		desc->status = DMA_COMPLETE;
758 
759 		list_add_tail(&desc->node, &imxdmac->ld_free);
760 		imxdmac->descs_allocated++;
761 	}
762 
763 	if (!imxdmac->descs_allocated)
764 		return -ENOMEM;
765 
766 	return imxdmac->descs_allocated;
767 }
768 
769 static void imxdma_free_chan_resources(struct dma_chan *chan)
770 {
771 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
772 	struct imxdma_engine *imxdma = imxdmac->imxdma;
773 	struct imxdma_desc *desc, *_desc;
774 	unsigned long flags;
775 
776 	spin_lock_irqsave(&imxdma->lock, flags);
777 
778 	imxdma_disable_hw(imxdmac);
779 	list_splice_tail_init(&imxdmac->ld_active, &imxdmac->ld_free);
780 	list_splice_tail_init(&imxdmac->ld_queue, &imxdmac->ld_free);
781 
782 	spin_unlock_irqrestore(&imxdma->lock, flags);
783 
784 	list_for_each_entry_safe(desc, _desc, &imxdmac->ld_free, node) {
785 		kfree(desc);
786 		imxdmac->descs_allocated--;
787 	}
788 	INIT_LIST_HEAD(&imxdmac->ld_free);
789 
790 	kfree(imxdmac->sg_list);
791 	imxdmac->sg_list = NULL;
792 }
793 
794 static struct dma_async_tx_descriptor *imxdma_prep_slave_sg(
795 		struct dma_chan *chan, struct scatterlist *sgl,
796 		unsigned int sg_len, enum dma_transfer_direction direction,
797 		unsigned long flags, void *context)
798 {
799 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
800 	struct scatterlist *sg;
801 	int i, dma_length = 0;
802 	struct imxdma_desc *desc;
803 
804 	if (list_empty(&imxdmac->ld_free) ||
805 	    imxdma_chan_is_doing_cyclic(imxdmac))
806 		return NULL;
807 
808 	desc = list_first_entry(&imxdmac->ld_free, struct imxdma_desc, node);
809 
810 	for_each_sg(sgl, sg, sg_len, i) {
811 		dma_length += sg_dma_len(sg);
812 	}
813 
814 	imxdma_config_write(chan, &imxdmac->config, direction);
815 
816 	switch (imxdmac->word_size) {
817 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
818 		if (sg_dma_len(sgl) & 3 || sgl->dma_address & 3)
819 			return NULL;
820 		break;
821 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
822 		if (sg_dma_len(sgl) & 1 || sgl->dma_address & 1)
823 			return NULL;
824 		break;
825 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
826 		break;
827 	default:
828 		return NULL;
829 	}
830 
831 	desc->type = IMXDMA_DESC_SLAVE_SG;
832 	desc->sg = sgl;
833 	desc->sgcount = sg_len;
834 	desc->len = dma_length;
835 	desc->direction = direction;
836 	if (direction == DMA_DEV_TO_MEM) {
837 		desc->src = imxdmac->per_address;
838 	} else {
839 		desc->dest = imxdmac->per_address;
840 	}
841 	desc->desc.callback = NULL;
842 	desc->desc.callback_param = NULL;
843 
844 	return &desc->desc;
845 }
846 
847 static struct dma_async_tx_descriptor *imxdma_prep_dma_cyclic(
848 		struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
849 		size_t period_len, enum dma_transfer_direction direction,
850 		unsigned long flags)
851 {
852 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
853 	struct imxdma_engine *imxdma = imxdmac->imxdma;
854 	struct imxdma_desc *desc;
855 	int i;
856 	unsigned int periods = buf_len / period_len;
857 
858 	dev_dbg(imxdma->dev, "%s channel: %d buf_len=%zu period_len=%zu\n",
859 			__func__, imxdmac->channel, buf_len, period_len);
860 
861 	if (list_empty(&imxdmac->ld_free) ||
862 	    imxdma_chan_is_doing_cyclic(imxdmac))
863 		return NULL;
864 
865 	desc = list_first_entry(&imxdmac->ld_free, struct imxdma_desc, node);
866 
867 	kfree(imxdmac->sg_list);
868 
869 	imxdmac->sg_list = kcalloc(periods + 1,
870 			sizeof(struct scatterlist), GFP_ATOMIC);
871 	if (!imxdmac->sg_list)
872 		return NULL;
873 
874 	sg_init_table(imxdmac->sg_list, periods);
875 
876 	for (i = 0; i < periods; i++) {
877 		sg_assign_page(&imxdmac->sg_list[i], NULL);
878 		imxdmac->sg_list[i].offset = 0;
879 		imxdmac->sg_list[i].dma_address = dma_addr;
880 		sg_dma_len(&imxdmac->sg_list[i]) = period_len;
881 		dma_addr += period_len;
882 	}
883 
884 	/* close the loop */
885 	sg_chain(imxdmac->sg_list, periods + 1, imxdmac->sg_list);
886 
887 	desc->type = IMXDMA_DESC_CYCLIC;
888 	desc->sg = imxdmac->sg_list;
889 	desc->sgcount = periods;
890 	desc->len = IMX_DMA_LENGTH_LOOP;
891 	desc->direction = direction;
892 	if (direction == DMA_DEV_TO_MEM) {
893 		desc->src = imxdmac->per_address;
894 	} else {
895 		desc->dest = imxdmac->per_address;
896 	}
897 	desc->desc.callback = NULL;
898 	desc->desc.callback_param = NULL;
899 
900 	imxdma_config_write(chan, &imxdmac->config, direction);
901 
902 	return &desc->desc;
903 }
904 
905 static struct dma_async_tx_descriptor *imxdma_prep_dma_memcpy(
906 	struct dma_chan *chan, dma_addr_t dest,
907 	dma_addr_t src, size_t len, unsigned long flags)
908 {
909 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
910 	struct imxdma_engine *imxdma = imxdmac->imxdma;
911 	struct imxdma_desc *desc;
912 
913 	dev_dbg(imxdma->dev, "%s channel: %d src=0x%llx dst=0x%llx len=%zu\n",
914 		__func__, imxdmac->channel, (unsigned long long)src,
915 		(unsigned long long)dest, len);
916 
917 	if (list_empty(&imxdmac->ld_free) ||
918 	    imxdma_chan_is_doing_cyclic(imxdmac))
919 		return NULL;
920 
921 	desc = list_first_entry(&imxdmac->ld_free, struct imxdma_desc, node);
922 
923 	desc->type = IMXDMA_DESC_MEMCPY;
924 	desc->src = src;
925 	desc->dest = dest;
926 	desc->len = len;
927 	desc->direction = DMA_MEM_TO_MEM;
928 	desc->config_port = IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR;
929 	desc->config_mem = IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR;
930 	desc->desc.callback = NULL;
931 	desc->desc.callback_param = NULL;
932 
933 	return &desc->desc;
934 }
935 
936 static struct dma_async_tx_descriptor *imxdma_prep_dma_interleaved(
937 	struct dma_chan *chan, struct dma_interleaved_template *xt,
938 	unsigned long flags)
939 {
940 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
941 	struct imxdma_engine *imxdma = imxdmac->imxdma;
942 	struct imxdma_desc *desc;
943 
944 	dev_dbg(imxdma->dev, "%s channel: %d src_start=0x%llx dst_start=0x%llx\n"
945 		"   src_sgl=%s dst_sgl=%s numf=%zu frame_size=%zu\n", __func__,
946 		imxdmac->channel, (unsigned long long)xt->src_start,
947 		(unsigned long long) xt->dst_start,
948 		xt->src_sgl ? "true" : "false", xt->dst_sgl ? "true" : "false",
949 		xt->numf, xt->frame_size);
950 
951 	if (list_empty(&imxdmac->ld_free) ||
952 	    imxdma_chan_is_doing_cyclic(imxdmac))
953 		return NULL;
954 
955 	if (xt->frame_size != 1 || xt->numf <= 0 || xt->dir != DMA_MEM_TO_MEM)
956 		return NULL;
957 
958 	desc = list_first_entry(&imxdmac->ld_free, struct imxdma_desc, node);
959 
960 	desc->type = IMXDMA_DESC_INTERLEAVED;
961 	desc->src = xt->src_start;
962 	desc->dest = xt->dst_start;
963 	desc->x = xt->sgl[0].size;
964 	desc->y = xt->numf;
965 	desc->w = xt->sgl[0].icg + desc->x;
966 	desc->len = desc->x * desc->y;
967 	desc->direction = DMA_MEM_TO_MEM;
968 	desc->config_port = IMX_DMA_MEMSIZE_32;
969 	desc->config_mem = IMX_DMA_MEMSIZE_32;
970 	if (xt->src_sgl)
971 		desc->config_mem |= IMX_DMA_TYPE_2D;
972 	if (xt->dst_sgl)
973 		desc->config_port |= IMX_DMA_TYPE_2D;
974 	desc->desc.callback = NULL;
975 	desc->desc.callback_param = NULL;
976 
977 	return &desc->desc;
978 }
979 
980 static void imxdma_issue_pending(struct dma_chan *chan)
981 {
982 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
983 	struct imxdma_engine *imxdma = imxdmac->imxdma;
984 	struct imxdma_desc *desc;
985 	unsigned long flags;
986 
987 	spin_lock_irqsave(&imxdma->lock, flags);
988 	if (list_empty(&imxdmac->ld_active) &&
989 	    !list_empty(&imxdmac->ld_queue)) {
990 		desc = list_first_entry(&imxdmac->ld_queue,
991 					struct imxdma_desc, node);
992 
993 		if (imxdma_xfer_desc(desc) < 0) {
994 			dev_warn(imxdma->dev,
995 				 "%s: channel: %d couldn't issue DMA xfer\n",
996 				 __func__, imxdmac->channel);
997 		} else {
998 			list_move_tail(imxdmac->ld_queue.next,
999 				       &imxdmac->ld_active);
1000 		}
1001 	}
1002 	spin_unlock_irqrestore(&imxdma->lock, flags);
1003 }
1004 
1005 static bool imxdma_filter_fn(struct dma_chan *chan, void *param)
1006 {
1007 	struct imxdma_filter_data *fdata = param;
1008 	struct imxdma_channel *imxdma_chan = to_imxdma_chan(chan);
1009 
1010 	if (chan->device->dev != fdata->imxdma->dev)
1011 		return false;
1012 
1013 	imxdma_chan->dma_request = fdata->request;
1014 	chan->private = NULL;
1015 
1016 	return true;
1017 }
1018 
1019 static struct dma_chan *imxdma_xlate(struct of_phandle_args *dma_spec,
1020 						struct of_dma *ofdma)
1021 {
1022 	int count = dma_spec->args_count;
1023 	struct imxdma_engine *imxdma = ofdma->of_dma_data;
1024 	struct imxdma_filter_data fdata = {
1025 		.imxdma = imxdma,
1026 	};
1027 
1028 	if (count != 1)
1029 		return NULL;
1030 
1031 	fdata.request = dma_spec->args[0];
1032 
1033 	return dma_request_channel(imxdma->dma_device.cap_mask,
1034 					imxdma_filter_fn, &fdata);
1035 }
1036 
1037 static int __init imxdma_probe(struct platform_device *pdev)
1038 {
1039 	struct imxdma_engine *imxdma;
1040 	int ret, i;
1041 	int irq, irq_err;
1042 
1043 	imxdma = devm_kzalloc(&pdev->dev, sizeof(*imxdma), GFP_KERNEL);
1044 	if (!imxdma)
1045 		return -ENOMEM;
1046 
1047 	imxdma->dev = &pdev->dev;
1048 	imxdma->devtype = (uintptr_t)of_device_get_match_data(&pdev->dev);
1049 
1050 	imxdma->base = devm_platform_ioremap_resource(pdev, 0);
1051 	if (IS_ERR(imxdma->base))
1052 		return PTR_ERR(imxdma->base);
1053 
1054 	irq = platform_get_irq(pdev, 0);
1055 	if (irq < 0)
1056 		return irq;
1057 
1058 	imxdma->dma_ipg = devm_clk_get(&pdev->dev, "ipg");
1059 	if (IS_ERR(imxdma->dma_ipg))
1060 		return PTR_ERR(imxdma->dma_ipg);
1061 
1062 	imxdma->dma_ahb = devm_clk_get(&pdev->dev, "ahb");
1063 	if (IS_ERR(imxdma->dma_ahb))
1064 		return PTR_ERR(imxdma->dma_ahb);
1065 
1066 	ret = clk_prepare_enable(imxdma->dma_ipg);
1067 	if (ret)
1068 		return ret;
1069 	ret = clk_prepare_enable(imxdma->dma_ahb);
1070 	if (ret)
1071 		goto disable_dma_ipg_clk;
1072 
1073 	/* reset DMA module */
1074 	imx_dmav1_writel(imxdma, DCR_DRST, DMA_DCR);
1075 
1076 	if (is_imx1_dma(imxdma)) {
1077 		ret = devm_request_irq(&pdev->dev, irq,
1078 				       dma_irq_handler, 0, "DMA", imxdma);
1079 		if (ret) {
1080 			dev_warn(imxdma->dev, "Can't register IRQ for DMA\n");
1081 			goto disable_dma_ahb_clk;
1082 		}
1083 		imxdma->irq = irq;
1084 
1085 		irq_err = platform_get_irq(pdev, 1);
1086 		if (irq_err < 0) {
1087 			ret = irq_err;
1088 			goto disable_dma_ahb_clk;
1089 		}
1090 
1091 		ret = devm_request_irq(&pdev->dev, irq_err,
1092 				       imxdma_err_handler, 0, "DMA", imxdma);
1093 		if (ret) {
1094 			dev_warn(imxdma->dev, "Can't register ERRIRQ for DMA\n");
1095 			goto disable_dma_ahb_clk;
1096 		}
1097 		imxdma->irq_err = irq_err;
1098 	}
1099 
1100 	/* enable DMA module */
1101 	imx_dmav1_writel(imxdma, DCR_DEN, DMA_DCR);
1102 
1103 	/* clear all interrupts */
1104 	imx_dmav1_writel(imxdma, (1 << IMX_DMA_CHANNELS) - 1, DMA_DISR);
1105 
1106 	/* disable interrupts */
1107 	imx_dmav1_writel(imxdma, (1 << IMX_DMA_CHANNELS) - 1, DMA_DIMR);
1108 
1109 	INIT_LIST_HEAD(&imxdma->dma_device.channels);
1110 
1111 	dma_cap_set(DMA_SLAVE, imxdma->dma_device.cap_mask);
1112 	dma_cap_set(DMA_CYCLIC, imxdma->dma_device.cap_mask);
1113 	dma_cap_set(DMA_MEMCPY, imxdma->dma_device.cap_mask);
1114 	dma_cap_set(DMA_INTERLEAVE, imxdma->dma_device.cap_mask);
1115 
1116 	/* Initialize 2D global parameters */
1117 	for (i = 0; i < IMX_DMA_2D_SLOTS; i++)
1118 		imxdma->slots_2d[i].count = 0;
1119 
1120 	spin_lock_init(&imxdma->lock);
1121 
1122 	/* Initialize channel parameters */
1123 	for (i = 0; i < IMX_DMA_CHANNELS; i++) {
1124 		struct imxdma_channel *imxdmac = &imxdma->channel[i];
1125 
1126 		if (!is_imx1_dma(imxdma)) {
1127 			ret = devm_request_irq(&pdev->dev, irq + i,
1128 					dma_irq_handler, 0, "DMA", imxdma);
1129 			if (ret) {
1130 				dev_warn(imxdma->dev, "Can't register IRQ %d "
1131 					 "for DMA channel %d\n",
1132 					 irq + i, i);
1133 				goto disable_dma_ahb_clk;
1134 			}
1135 
1136 			imxdmac->irq = irq + i;
1137 			timer_setup(&imxdmac->watchdog, imxdma_watchdog, 0);
1138 		}
1139 
1140 		imxdmac->imxdma = imxdma;
1141 
1142 		INIT_LIST_HEAD(&imxdmac->ld_queue);
1143 		INIT_LIST_HEAD(&imxdmac->ld_free);
1144 		INIT_LIST_HEAD(&imxdmac->ld_active);
1145 
1146 		tasklet_setup(&imxdmac->dma_tasklet, imxdma_tasklet);
1147 		imxdmac->chan.device = &imxdma->dma_device;
1148 		dma_cookie_init(&imxdmac->chan);
1149 		imxdmac->channel = i;
1150 
1151 		/* Add the channel to the DMAC list */
1152 		list_add_tail(&imxdmac->chan.device_node,
1153 			      &imxdma->dma_device.channels);
1154 	}
1155 
1156 	imxdma->dma_device.dev = &pdev->dev;
1157 
1158 	imxdma->dma_device.device_alloc_chan_resources = imxdma_alloc_chan_resources;
1159 	imxdma->dma_device.device_free_chan_resources = imxdma_free_chan_resources;
1160 	imxdma->dma_device.device_tx_status = imxdma_tx_status;
1161 	imxdma->dma_device.device_prep_slave_sg = imxdma_prep_slave_sg;
1162 	imxdma->dma_device.device_prep_dma_cyclic = imxdma_prep_dma_cyclic;
1163 	imxdma->dma_device.device_prep_dma_memcpy = imxdma_prep_dma_memcpy;
1164 	imxdma->dma_device.device_prep_interleaved_dma = imxdma_prep_dma_interleaved;
1165 	imxdma->dma_device.device_config = imxdma_config;
1166 	imxdma->dma_device.device_terminate_all = imxdma_terminate_all;
1167 	imxdma->dma_device.device_issue_pending = imxdma_issue_pending;
1168 
1169 	platform_set_drvdata(pdev, imxdma);
1170 
1171 	imxdma->dma_device.copy_align = DMAENGINE_ALIGN_4_BYTES;
1172 	dma_set_max_seg_size(imxdma->dma_device.dev, 0xffffff);
1173 
1174 	ret = dma_async_device_register(&imxdma->dma_device);
1175 	if (ret) {
1176 		dev_err(&pdev->dev, "unable to register\n");
1177 		goto disable_dma_ahb_clk;
1178 	}
1179 
1180 	if (pdev->dev.of_node) {
1181 		ret = of_dma_controller_register(pdev->dev.of_node,
1182 				imxdma_xlate, imxdma);
1183 		if (ret) {
1184 			dev_err(&pdev->dev, "unable to register of_dma_controller\n");
1185 			goto err_of_dma_controller;
1186 		}
1187 	}
1188 
1189 	return 0;
1190 
1191 err_of_dma_controller:
1192 	dma_async_device_unregister(&imxdma->dma_device);
1193 disable_dma_ahb_clk:
1194 	clk_disable_unprepare(imxdma->dma_ahb);
1195 disable_dma_ipg_clk:
1196 	clk_disable_unprepare(imxdma->dma_ipg);
1197 	return ret;
1198 }
1199 
1200 static void imxdma_free_irq(struct platform_device *pdev, struct imxdma_engine *imxdma)
1201 {
1202 	int i;
1203 
1204 	if (is_imx1_dma(imxdma)) {
1205 		disable_irq(imxdma->irq);
1206 		disable_irq(imxdma->irq_err);
1207 	}
1208 
1209 	for (i = 0; i < IMX_DMA_CHANNELS; i++) {
1210 		struct imxdma_channel *imxdmac = &imxdma->channel[i];
1211 
1212 		if (!is_imx1_dma(imxdma))
1213 			disable_irq(imxdmac->irq);
1214 
1215 		tasklet_kill(&imxdmac->dma_tasklet);
1216 	}
1217 }
1218 
1219 static int imxdma_remove(struct platform_device *pdev)
1220 {
1221 	struct imxdma_engine *imxdma = platform_get_drvdata(pdev);
1222 
1223 	imxdma_free_irq(pdev, imxdma);
1224 
1225         dma_async_device_unregister(&imxdma->dma_device);
1226 
1227 	if (pdev->dev.of_node)
1228 		of_dma_controller_free(pdev->dev.of_node);
1229 
1230 	clk_disable_unprepare(imxdma->dma_ipg);
1231 	clk_disable_unprepare(imxdma->dma_ahb);
1232 
1233         return 0;
1234 }
1235 
1236 static struct platform_driver imxdma_driver = {
1237 	.driver		= {
1238 		.name	= "imx-dma",
1239 		.of_match_table = imx_dma_of_dev_id,
1240 	},
1241 	.remove		= imxdma_remove,
1242 };
1243 
1244 static int __init imxdma_module_init(void)
1245 {
1246 	return platform_driver_probe(&imxdma_driver, imxdma_probe);
1247 }
1248 subsys_initcall(imxdma_module_init);
1249 
1250 MODULE_AUTHOR("Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>");
1251 MODULE_DESCRIPTION("i.MX dma driver");
1252 MODULE_LICENSE("GPL");
1253