xref: /linux/drivers/dma/imx-dma.c (revision cf02820041668b14cbfa0fbd2bab45ac79bd6174)
1 /*
2  * drivers/dma/imx-dma.c
3  *
4  * This file contains a driver for the Freescale i.MX DMA engine
5  * found on i.MX1/21/27
6  *
7  * Copyright 2010 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
8  * Copyright 2012 Javier Martin, Vista Silicon <javier.martin@vista-silicon.com>
9  *
10  * The code contained herein is licensed under the GNU General Public
11  * License. You may obtain a copy of the GNU General Public License
12  * Version 2 or later at the following locations:
13  *
14  * http://www.opensource.org/licenses/gpl-license.html
15  * http://www.gnu.org/copyleft/gpl.html
16  */
17 #include <linux/init.h>
18 #include <linux/types.h>
19 #include <linux/mm.h>
20 #include <linux/interrupt.h>
21 #include <linux/spinlock.h>
22 #include <linux/device.h>
23 #include <linux/dma-mapping.h>
24 #include <linux/slab.h>
25 #include <linux/platform_device.h>
26 #include <linux/clk.h>
27 #include <linux/dmaengine.h>
28 #include <linux/module.h>
29 
30 #include <asm/irq.h>
31 #include <linux/platform_data/dma-imx.h>
32 #include <mach/hardware.h>
33 
34 #include "dmaengine.h"
35 #define IMXDMA_MAX_CHAN_DESCRIPTORS	16
36 #define IMX_DMA_CHANNELS  16
37 
38 #define IMX_DMA_2D_SLOTS	2
39 #define IMX_DMA_2D_SLOT_A	0
40 #define IMX_DMA_2D_SLOT_B	1
41 
42 #define IMX_DMA_LENGTH_LOOP	((unsigned int)-1)
43 #define IMX_DMA_MEMSIZE_32	(0 << 4)
44 #define IMX_DMA_MEMSIZE_8	(1 << 4)
45 #define IMX_DMA_MEMSIZE_16	(2 << 4)
46 #define IMX_DMA_TYPE_LINEAR	(0 << 10)
47 #define IMX_DMA_TYPE_2D		(1 << 10)
48 #define IMX_DMA_TYPE_FIFO	(2 << 10)
49 
50 #define IMX_DMA_ERR_BURST     (1 << 0)
51 #define IMX_DMA_ERR_REQUEST   (1 << 1)
52 #define IMX_DMA_ERR_TRANSFER  (1 << 2)
53 #define IMX_DMA_ERR_BUFFER    (1 << 3)
54 #define IMX_DMA_ERR_TIMEOUT   (1 << 4)
55 
56 #define DMA_DCR     0x00		/* Control Register */
57 #define DMA_DISR    0x04		/* Interrupt status Register */
58 #define DMA_DIMR    0x08		/* Interrupt mask Register */
59 #define DMA_DBTOSR  0x0c		/* Burst timeout status Register */
60 #define DMA_DRTOSR  0x10		/* Request timeout Register */
61 #define DMA_DSESR   0x14		/* Transfer Error Status Register */
62 #define DMA_DBOSR   0x18		/* Buffer overflow status Register */
63 #define DMA_DBTOCR  0x1c		/* Burst timeout control Register */
64 #define DMA_WSRA    0x40		/* W-Size Register A */
65 #define DMA_XSRA    0x44		/* X-Size Register A */
66 #define DMA_YSRA    0x48		/* Y-Size Register A */
67 #define DMA_WSRB    0x4c		/* W-Size Register B */
68 #define DMA_XSRB    0x50		/* X-Size Register B */
69 #define DMA_YSRB    0x54		/* Y-Size Register B */
70 #define DMA_SAR(x)  (0x80 + ((x) << 6))	/* Source Address Registers */
71 #define DMA_DAR(x)  (0x84 + ((x) << 6))	/* Destination Address Registers */
72 #define DMA_CNTR(x) (0x88 + ((x) << 6))	/* Count Registers */
73 #define DMA_CCR(x)  (0x8c + ((x) << 6))	/* Control Registers */
74 #define DMA_RSSR(x) (0x90 + ((x) << 6))	/* Request source select Registers */
75 #define DMA_BLR(x)  (0x94 + ((x) << 6))	/* Burst length Registers */
76 #define DMA_RTOR(x) (0x98 + ((x) << 6))	/* Request timeout Registers */
77 #define DMA_BUCR(x) (0x98 + ((x) << 6))	/* Bus Utilization Registers */
78 #define DMA_CCNR(x) (0x9C + ((x) << 6))	/* Channel counter Registers */
79 
80 #define DCR_DRST           (1<<1)
81 #define DCR_DEN            (1<<0)
82 #define DBTOCR_EN          (1<<15)
83 #define DBTOCR_CNT(x)      ((x) & 0x7fff)
84 #define CNTR_CNT(x)        ((x) & 0xffffff)
85 #define CCR_ACRPT          (1<<14)
86 #define CCR_DMOD_LINEAR    (0x0 << 12)
87 #define CCR_DMOD_2D        (0x1 << 12)
88 #define CCR_DMOD_FIFO      (0x2 << 12)
89 #define CCR_DMOD_EOBFIFO   (0x3 << 12)
90 #define CCR_SMOD_LINEAR    (0x0 << 10)
91 #define CCR_SMOD_2D        (0x1 << 10)
92 #define CCR_SMOD_FIFO      (0x2 << 10)
93 #define CCR_SMOD_EOBFIFO   (0x3 << 10)
94 #define CCR_MDIR_DEC       (1<<9)
95 #define CCR_MSEL_B         (1<<8)
96 #define CCR_DSIZ_32        (0x0 << 6)
97 #define CCR_DSIZ_8         (0x1 << 6)
98 #define CCR_DSIZ_16        (0x2 << 6)
99 #define CCR_SSIZ_32        (0x0 << 4)
100 #define CCR_SSIZ_8         (0x1 << 4)
101 #define CCR_SSIZ_16        (0x2 << 4)
102 #define CCR_REN            (1<<3)
103 #define CCR_RPT            (1<<2)
104 #define CCR_FRC            (1<<1)
105 #define CCR_CEN            (1<<0)
106 #define RTOR_EN            (1<<15)
107 #define RTOR_CLK           (1<<14)
108 #define RTOR_PSC           (1<<13)
109 
110 enum  imxdma_prep_type {
111 	IMXDMA_DESC_MEMCPY,
112 	IMXDMA_DESC_INTERLEAVED,
113 	IMXDMA_DESC_SLAVE_SG,
114 	IMXDMA_DESC_CYCLIC,
115 };
116 
117 struct imx_dma_2d_config {
118 	u16		xsr;
119 	u16		ysr;
120 	u16		wsr;
121 	int		count;
122 };
123 
124 struct imxdma_desc {
125 	struct list_head		node;
126 	struct dma_async_tx_descriptor	desc;
127 	enum dma_status			status;
128 	dma_addr_t			src;
129 	dma_addr_t			dest;
130 	size_t				len;
131 	enum dma_transfer_direction	direction;
132 	enum imxdma_prep_type		type;
133 	/* For memcpy and interleaved */
134 	unsigned int			config_port;
135 	unsigned int			config_mem;
136 	/* For interleaved transfers */
137 	unsigned int			x;
138 	unsigned int			y;
139 	unsigned int			w;
140 	/* For slave sg and cyclic */
141 	struct scatterlist		*sg;
142 	unsigned int			sgcount;
143 };
144 
145 struct imxdma_channel {
146 	int				hw_chaining;
147 	struct timer_list		watchdog;
148 	struct imxdma_engine		*imxdma;
149 	unsigned int			channel;
150 
151 	struct tasklet_struct		dma_tasklet;
152 	struct list_head		ld_free;
153 	struct list_head		ld_queue;
154 	struct list_head		ld_active;
155 	int				descs_allocated;
156 	enum dma_slave_buswidth		word_size;
157 	dma_addr_t			per_address;
158 	u32				watermark_level;
159 	struct dma_chan			chan;
160 	struct dma_async_tx_descriptor	desc;
161 	enum dma_status			status;
162 	int				dma_request;
163 	struct scatterlist		*sg_list;
164 	u32				ccr_from_device;
165 	u32				ccr_to_device;
166 	bool				enabled_2d;
167 	int				slot_2d;
168 };
169 
170 struct imxdma_engine {
171 	struct device			*dev;
172 	struct device_dma_parameters	dma_parms;
173 	struct dma_device		dma_device;
174 	void __iomem			*base;
175 	struct clk			*dma_ahb;
176 	struct clk			*dma_ipg;
177 	spinlock_t			lock;
178 	struct imx_dma_2d_config	slots_2d[IMX_DMA_2D_SLOTS];
179 	struct imxdma_channel		channel[IMX_DMA_CHANNELS];
180 };
181 
182 static struct imxdma_channel *to_imxdma_chan(struct dma_chan *chan)
183 {
184 	return container_of(chan, struct imxdma_channel, chan);
185 }
186 
187 static inline bool imxdma_chan_is_doing_cyclic(struct imxdma_channel *imxdmac)
188 {
189 	struct imxdma_desc *desc;
190 
191 	if (!list_empty(&imxdmac->ld_active)) {
192 		desc = list_first_entry(&imxdmac->ld_active, struct imxdma_desc,
193 					node);
194 		if (desc->type == IMXDMA_DESC_CYCLIC)
195 			return true;
196 	}
197 	return false;
198 }
199 
200 
201 
202 static void imx_dmav1_writel(struct imxdma_engine *imxdma, unsigned val,
203 			     unsigned offset)
204 {
205 	__raw_writel(val, imxdma->base + offset);
206 }
207 
208 static unsigned imx_dmav1_readl(struct imxdma_engine *imxdma, unsigned offset)
209 {
210 	return __raw_readl(imxdma->base + offset);
211 }
212 
213 static int imxdma_hw_chain(struct imxdma_channel *imxdmac)
214 {
215 	if (cpu_is_mx27())
216 		return imxdmac->hw_chaining;
217 	else
218 		return 0;
219 }
220 
221 /*
222  * imxdma_sg_next - prepare next chunk for scatter-gather DMA emulation
223  */
224 static inline int imxdma_sg_next(struct imxdma_desc *d)
225 {
226 	struct imxdma_channel *imxdmac = to_imxdma_chan(d->desc.chan);
227 	struct imxdma_engine *imxdma = imxdmac->imxdma;
228 	struct scatterlist *sg = d->sg;
229 	unsigned long now;
230 
231 	now = min(d->len, sg_dma_len(sg));
232 	if (d->len != IMX_DMA_LENGTH_LOOP)
233 		d->len -= now;
234 
235 	if (d->direction == DMA_DEV_TO_MEM)
236 		imx_dmav1_writel(imxdma, sg->dma_address,
237 				 DMA_DAR(imxdmac->channel));
238 	else
239 		imx_dmav1_writel(imxdma, sg->dma_address,
240 				 DMA_SAR(imxdmac->channel));
241 
242 	imx_dmav1_writel(imxdma, now, DMA_CNTR(imxdmac->channel));
243 
244 	dev_dbg(imxdma->dev, " %s channel: %d dst 0x%08x, src 0x%08x, "
245 		"size 0x%08x\n", __func__, imxdmac->channel,
246 		 imx_dmav1_readl(imxdma, DMA_DAR(imxdmac->channel)),
247 		 imx_dmav1_readl(imxdma, DMA_SAR(imxdmac->channel)),
248 		 imx_dmav1_readl(imxdma, DMA_CNTR(imxdmac->channel)));
249 
250 	return now;
251 }
252 
253 static void imxdma_enable_hw(struct imxdma_desc *d)
254 {
255 	struct imxdma_channel *imxdmac = to_imxdma_chan(d->desc.chan);
256 	struct imxdma_engine *imxdma = imxdmac->imxdma;
257 	int channel = imxdmac->channel;
258 	unsigned long flags;
259 
260 	dev_dbg(imxdma->dev, "%s channel %d\n", __func__, channel);
261 
262 	local_irq_save(flags);
263 
264 	imx_dmav1_writel(imxdma, 1 << channel, DMA_DISR);
265 	imx_dmav1_writel(imxdma, imx_dmav1_readl(imxdma, DMA_DIMR) &
266 			 ~(1 << channel), DMA_DIMR);
267 	imx_dmav1_writel(imxdma, imx_dmav1_readl(imxdma, DMA_CCR(channel)) |
268 			 CCR_CEN | CCR_ACRPT, DMA_CCR(channel));
269 
270 	if ((cpu_is_mx21() || cpu_is_mx27()) &&
271 			d->sg && imxdma_hw_chain(imxdmac)) {
272 		d->sg = sg_next(d->sg);
273 		if (d->sg) {
274 			u32 tmp;
275 			imxdma_sg_next(d);
276 			tmp = imx_dmav1_readl(imxdma, DMA_CCR(channel));
277 			imx_dmav1_writel(imxdma, tmp | CCR_RPT | CCR_ACRPT,
278 					 DMA_CCR(channel));
279 		}
280 	}
281 
282 	local_irq_restore(flags);
283 }
284 
285 static void imxdma_disable_hw(struct imxdma_channel *imxdmac)
286 {
287 	struct imxdma_engine *imxdma = imxdmac->imxdma;
288 	int channel = imxdmac->channel;
289 	unsigned long flags;
290 
291 	dev_dbg(imxdma->dev, "%s channel %d\n", __func__, channel);
292 
293 	if (imxdma_hw_chain(imxdmac))
294 		del_timer(&imxdmac->watchdog);
295 
296 	local_irq_save(flags);
297 	imx_dmav1_writel(imxdma, imx_dmav1_readl(imxdma, DMA_DIMR) |
298 			 (1 << channel), DMA_DIMR);
299 	imx_dmav1_writel(imxdma, imx_dmav1_readl(imxdma, DMA_CCR(channel)) &
300 			 ~CCR_CEN, DMA_CCR(channel));
301 	imx_dmav1_writel(imxdma, 1 << channel, DMA_DISR);
302 	local_irq_restore(flags);
303 }
304 
305 static void imxdma_watchdog(unsigned long data)
306 {
307 	struct imxdma_channel *imxdmac = (struct imxdma_channel *)data;
308 	struct imxdma_engine *imxdma = imxdmac->imxdma;
309 	int channel = imxdmac->channel;
310 
311 	imx_dmav1_writel(imxdma, 0, DMA_CCR(channel));
312 
313 	/* Tasklet watchdog error handler */
314 	tasklet_schedule(&imxdmac->dma_tasklet);
315 	dev_dbg(imxdma->dev, "channel %d: watchdog timeout!\n",
316 		imxdmac->channel);
317 }
318 
319 static irqreturn_t imxdma_err_handler(int irq, void *dev_id)
320 {
321 	struct imxdma_engine *imxdma = dev_id;
322 	unsigned int err_mask;
323 	int i, disr;
324 	int errcode;
325 
326 	disr = imx_dmav1_readl(imxdma, DMA_DISR);
327 
328 	err_mask = imx_dmav1_readl(imxdma, DMA_DBTOSR) |
329 		   imx_dmav1_readl(imxdma, DMA_DRTOSR) |
330 		   imx_dmav1_readl(imxdma, DMA_DSESR)  |
331 		   imx_dmav1_readl(imxdma, DMA_DBOSR);
332 
333 	if (!err_mask)
334 		return IRQ_HANDLED;
335 
336 	imx_dmav1_writel(imxdma, disr & err_mask, DMA_DISR);
337 
338 	for (i = 0; i < IMX_DMA_CHANNELS; i++) {
339 		if (!(err_mask & (1 << i)))
340 			continue;
341 		errcode = 0;
342 
343 		if (imx_dmav1_readl(imxdma, DMA_DBTOSR) & (1 << i)) {
344 			imx_dmav1_writel(imxdma, 1 << i, DMA_DBTOSR);
345 			errcode |= IMX_DMA_ERR_BURST;
346 		}
347 		if (imx_dmav1_readl(imxdma, DMA_DRTOSR) & (1 << i)) {
348 			imx_dmav1_writel(imxdma, 1 << i, DMA_DRTOSR);
349 			errcode |= IMX_DMA_ERR_REQUEST;
350 		}
351 		if (imx_dmav1_readl(imxdma, DMA_DSESR) & (1 << i)) {
352 			imx_dmav1_writel(imxdma, 1 << i, DMA_DSESR);
353 			errcode |= IMX_DMA_ERR_TRANSFER;
354 		}
355 		if (imx_dmav1_readl(imxdma, DMA_DBOSR) & (1 << i)) {
356 			imx_dmav1_writel(imxdma, 1 << i, DMA_DBOSR);
357 			errcode |= IMX_DMA_ERR_BUFFER;
358 		}
359 		/* Tasklet error handler */
360 		tasklet_schedule(&imxdma->channel[i].dma_tasklet);
361 
362 		printk(KERN_WARNING
363 		       "DMA timeout on channel %d -%s%s%s%s\n", i,
364 		       errcode & IMX_DMA_ERR_BURST ?    " burst" : "",
365 		       errcode & IMX_DMA_ERR_REQUEST ?  " request" : "",
366 		       errcode & IMX_DMA_ERR_TRANSFER ? " transfer" : "",
367 		       errcode & IMX_DMA_ERR_BUFFER ?   " buffer" : "");
368 	}
369 	return IRQ_HANDLED;
370 }
371 
372 static void dma_irq_handle_channel(struct imxdma_channel *imxdmac)
373 {
374 	struct imxdma_engine *imxdma = imxdmac->imxdma;
375 	int chno = imxdmac->channel;
376 	struct imxdma_desc *desc;
377 
378 	spin_lock(&imxdma->lock);
379 	if (list_empty(&imxdmac->ld_active)) {
380 		spin_unlock(&imxdma->lock);
381 		goto out;
382 	}
383 
384 	desc = list_first_entry(&imxdmac->ld_active,
385 				struct imxdma_desc,
386 				node);
387 	spin_unlock(&imxdma->lock);
388 
389 	if (desc->sg) {
390 		u32 tmp;
391 		desc->sg = sg_next(desc->sg);
392 
393 		if (desc->sg) {
394 			imxdma_sg_next(desc);
395 
396 			tmp = imx_dmav1_readl(imxdma, DMA_CCR(chno));
397 
398 			if (imxdma_hw_chain(imxdmac)) {
399 				/* FIXME: The timeout should probably be
400 				 * configurable
401 				 */
402 				mod_timer(&imxdmac->watchdog,
403 					jiffies + msecs_to_jiffies(500));
404 
405 				tmp |= CCR_CEN | CCR_RPT | CCR_ACRPT;
406 				imx_dmav1_writel(imxdma, tmp, DMA_CCR(chno));
407 			} else {
408 				imx_dmav1_writel(imxdma, tmp & ~CCR_CEN,
409 						 DMA_CCR(chno));
410 				tmp |= CCR_CEN;
411 			}
412 
413 			imx_dmav1_writel(imxdma, tmp, DMA_CCR(chno));
414 
415 			if (imxdma_chan_is_doing_cyclic(imxdmac))
416 				/* Tasklet progression */
417 				tasklet_schedule(&imxdmac->dma_tasklet);
418 
419 			return;
420 		}
421 
422 		if (imxdma_hw_chain(imxdmac)) {
423 			del_timer(&imxdmac->watchdog);
424 			return;
425 		}
426 	}
427 
428 out:
429 	imx_dmav1_writel(imxdma, 0, DMA_CCR(chno));
430 	/* Tasklet irq */
431 	tasklet_schedule(&imxdmac->dma_tasklet);
432 }
433 
434 static irqreturn_t dma_irq_handler(int irq, void *dev_id)
435 {
436 	struct imxdma_engine *imxdma = dev_id;
437 	int i, disr;
438 
439 	if (cpu_is_mx21() || cpu_is_mx27())
440 		imxdma_err_handler(irq, dev_id);
441 
442 	disr = imx_dmav1_readl(imxdma, DMA_DISR);
443 
444 	dev_dbg(imxdma->dev, "%s called, disr=0x%08x\n", __func__, disr);
445 
446 	imx_dmav1_writel(imxdma, disr, DMA_DISR);
447 	for (i = 0; i < IMX_DMA_CHANNELS; i++) {
448 		if (disr & (1 << i))
449 			dma_irq_handle_channel(&imxdma->channel[i]);
450 	}
451 
452 	return IRQ_HANDLED;
453 }
454 
455 static int imxdma_xfer_desc(struct imxdma_desc *d)
456 {
457 	struct imxdma_channel *imxdmac = to_imxdma_chan(d->desc.chan);
458 	struct imxdma_engine *imxdma = imxdmac->imxdma;
459 	unsigned long flags;
460 	int slot = -1;
461 	int i;
462 
463 	/* Configure and enable */
464 	switch (d->type) {
465 	case IMXDMA_DESC_INTERLEAVED:
466 		/* Try to get a free 2D slot */
467 		spin_lock_irqsave(&imxdma->lock, flags);
468 		for (i = 0; i < IMX_DMA_2D_SLOTS; i++) {
469 			if ((imxdma->slots_2d[i].count > 0) &&
470 			((imxdma->slots_2d[i].xsr != d->x) ||
471 			(imxdma->slots_2d[i].ysr != d->y) ||
472 			(imxdma->slots_2d[i].wsr != d->w)))
473 				continue;
474 			slot = i;
475 			break;
476 		}
477 		if (slot < 0) {
478 			spin_unlock_irqrestore(&imxdma->lock, flags);
479 			return -EBUSY;
480 		}
481 
482 		imxdma->slots_2d[slot].xsr = d->x;
483 		imxdma->slots_2d[slot].ysr = d->y;
484 		imxdma->slots_2d[slot].wsr = d->w;
485 		imxdma->slots_2d[slot].count++;
486 
487 		imxdmac->slot_2d = slot;
488 		imxdmac->enabled_2d = true;
489 		spin_unlock_irqrestore(&imxdma->lock, flags);
490 
491 		if (slot == IMX_DMA_2D_SLOT_A) {
492 			d->config_mem &= ~CCR_MSEL_B;
493 			d->config_port &= ~CCR_MSEL_B;
494 			imx_dmav1_writel(imxdma, d->x, DMA_XSRA);
495 			imx_dmav1_writel(imxdma, d->y, DMA_YSRA);
496 			imx_dmav1_writel(imxdma, d->w, DMA_WSRA);
497 		} else {
498 			d->config_mem |= CCR_MSEL_B;
499 			d->config_port |= CCR_MSEL_B;
500 			imx_dmav1_writel(imxdma, d->x, DMA_XSRB);
501 			imx_dmav1_writel(imxdma, d->y, DMA_YSRB);
502 			imx_dmav1_writel(imxdma, d->w, DMA_WSRB);
503 		}
504 		/*
505 		 * We fall-through here intentionally, since a 2D transfer is
506 		 * similar to MEMCPY just adding the 2D slot configuration.
507 		 */
508 	case IMXDMA_DESC_MEMCPY:
509 		imx_dmav1_writel(imxdma, d->src, DMA_SAR(imxdmac->channel));
510 		imx_dmav1_writel(imxdma, d->dest, DMA_DAR(imxdmac->channel));
511 		imx_dmav1_writel(imxdma, d->config_mem | (d->config_port << 2),
512 			 DMA_CCR(imxdmac->channel));
513 
514 		imx_dmav1_writel(imxdma, d->len, DMA_CNTR(imxdmac->channel));
515 
516 		dev_dbg(imxdma->dev, "%s channel: %d dest=0x%08x src=0x%08x "
517 			"dma_length=%d\n", __func__, imxdmac->channel,
518 			d->dest, d->src, d->len);
519 
520 		break;
521 	/* Cyclic transfer is the same as slave_sg with special sg configuration. */
522 	case IMXDMA_DESC_CYCLIC:
523 	case IMXDMA_DESC_SLAVE_SG:
524 		if (d->direction == DMA_DEV_TO_MEM) {
525 			imx_dmav1_writel(imxdma, imxdmac->per_address,
526 					 DMA_SAR(imxdmac->channel));
527 			imx_dmav1_writel(imxdma, imxdmac->ccr_from_device,
528 					 DMA_CCR(imxdmac->channel));
529 
530 			dev_dbg(imxdma->dev, "%s channel: %d sg=%p sgcount=%d "
531 				"total length=%d dev_addr=0x%08x (dev2mem)\n",
532 				__func__, imxdmac->channel, d->sg, d->sgcount,
533 				d->len, imxdmac->per_address);
534 		} else if (d->direction == DMA_MEM_TO_DEV) {
535 			imx_dmav1_writel(imxdma, imxdmac->per_address,
536 					 DMA_DAR(imxdmac->channel));
537 			imx_dmav1_writel(imxdma, imxdmac->ccr_to_device,
538 					 DMA_CCR(imxdmac->channel));
539 
540 			dev_dbg(imxdma->dev, "%s channel: %d sg=%p sgcount=%d "
541 				"total length=%d dev_addr=0x%08x (mem2dev)\n",
542 				__func__, imxdmac->channel, d->sg, d->sgcount,
543 				d->len, imxdmac->per_address);
544 		} else {
545 			dev_err(imxdma->dev, "%s channel: %d bad dma mode\n",
546 				__func__, imxdmac->channel);
547 			return -EINVAL;
548 		}
549 
550 		imxdma_sg_next(d);
551 
552 		break;
553 	default:
554 		return -EINVAL;
555 	}
556 	imxdma_enable_hw(d);
557 	return 0;
558 }
559 
560 static void imxdma_tasklet(unsigned long data)
561 {
562 	struct imxdma_channel *imxdmac = (void *)data;
563 	struct imxdma_engine *imxdma = imxdmac->imxdma;
564 	struct imxdma_desc *desc;
565 
566 	spin_lock(&imxdma->lock);
567 
568 	if (list_empty(&imxdmac->ld_active)) {
569 		/* Someone might have called terminate all */
570 		goto out;
571 	}
572 	desc = list_first_entry(&imxdmac->ld_active, struct imxdma_desc, node);
573 
574 	if (desc->desc.callback)
575 		desc->desc.callback(desc->desc.callback_param);
576 
577 	/* If we are dealing with a cyclic descriptor, keep it on ld_active
578 	 * and dont mark the descriptor as complete.
579 	 * Only in non-cyclic cases it would be marked as complete
580 	 */
581 	if (imxdma_chan_is_doing_cyclic(imxdmac))
582 		goto out;
583 	else
584 		dma_cookie_complete(&desc->desc);
585 
586 	/* Free 2D slot if it was an interleaved transfer */
587 	if (imxdmac->enabled_2d) {
588 		imxdma->slots_2d[imxdmac->slot_2d].count--;
589 		imxdmac->enabled_2d = false;
590 	}
591 
592 	list_move_tail(imxdmac->ld_active.next, &imxdmac->ld_free);
593 
594 	if (!list_empty(&imxdmac->ld_queue)) {
595 		desc = list_first_entry(&imxdmac->ld_queue, struct imxdma_desc,
596 					node);
597 		list_move_tail(imxdmac->ld_queue.next, &imxdmac->ld_active);
598 		if (imxdma_xfer_desc(desc) < 0)
599 			dev_warn(imxdma->dev, "%s: channel: %d couldn't xfer desc\n",
600 				 __func__, imxdmac->channel);
601 	}
602 out:
603 	spin_unlock(&imxdma->lock);
604 }
605 
606 static int imxdma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
607 		unsigned long arg)
608 {
609 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
610 	struct dma_slave_config *dmaengine_cfg = (void *)arg;
611 	struct imxdma_engine *imxdma = imxdmac->imxdma;
612 	unsigned long flags;
613 	unsigned int mode = 0;
614 
615 	switch (cmd) {
616 	case DMA_TERMINATE_ALL:
617 		imxdma_disable_hw(imxdmac);
618 
619 		spin_lock_irqsave(&imxdma->lock, flags);
620 		list_splice_tail_init(&imxdmac->ld_active, &imxdmac->ld_free);
621 		list_splice_tail_init(&imxdmac->ld_queue, &imxdmac->ld_free);
622 		spin_unlock_irqrestore(&imxdma->lock, flags);
623 		return 0;
624 	case DMA_SLAVE_CONFIG:
625 		if (dmaengine_cfg->direction == DMA_DEV_TO_MEM) {
626 			imxdmac->per_address = dmaengine_cfg->src_addr;
627 			imxdmac->watermark_level = dmaengine_cfg->src_maxburst;
628 			imxdmac->word_size = dmaengine_cfg->src_addr_width;
629 		} else {
630 			imxdmac->per_address = dmaengine_cfg->dst_addr;
631 			imxdmac->watermark_level = dmaengine_cfg->dst_maxburst;
632 			imxdmac->word_size = dmaengine_cfg->dst_addr_width;
633 		}
634 
635 		switch (imxdmac->word_size) {
636 		case DMA_SLAVE_BUSWIDTH_1_BYTE:
637 			mode = IMX_DMA_MEMSIZE_8;
638 			break;
639 		case DMA_SLAVE_BUSWIDTH_2_BYTES:
640 			mode = IMX_DMA_MEMSIZE_16;
641 			break;
642 		default:
643 		case DMA_SLAVE_BUSWIDTH_4_BYTES:
644 			mode = IMX_DMA_MEMSIZE_32;
645 			break;
646 		}
647 
648 		imxdmac->hw_chaining = 1;
649 		if (!imxdma_hw_chain(imxdmac))
650 			return -EINVAL;
651 		imxdmac->ccr_from_device = (mode | IMX_DMA_TYPE_FIFO) |
652 			((IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR) << 2) |
653 			CCR_REN;
654 		imxdmac->ccr_to_device =
655 			(IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR) |
656 			((mode | IMX_DMA_TYPE_FIFO) << 2) | CCR_REN;
657 		imx_dmav1_writel(imxdma, imxdmac->dma_request,
658 				 DMA_RSSR(imxdmac->channel));
659 
660 		/* Set burst length */
661 		imx_dmav1_writel(imxdma, imxdmac->watermark_level *
662 				imxdmac->word_size, DMA_BLR(imxdmac->channel));
663 
664 		return 0;
665 	default:
666 		return -ENOSYS;
667 	}
668 
669 	return -EINVAL;
670 }
671 
672 static enum dma_status imxdma_tx_status(struct dma_chan *chan,
673 					    dma_cookie_t cookie,
674 					    struct dma_tx_state *txstate)
675 {
676 	return dma_cookie_status(chan, cookie, txstate);
677 }
678 
679 static dma_cookie_t imxdma_tx_submit(struct dma_async_tx_descriptor *tx)
680 {
681 	struct imxdma_channel *imxdmac = to_imxdma_chan(tx->chan);
682 	struct imxdma_engine *imxdma = imxdmac->imxdma;
683 	dma_cookie_t cookie;
684 	unsigned long flags;
685 
686 	spin_lock_irqsave(&imxdma->lock, flags);
687 	list_move_tail(imxdmac->ld_free.next, &imxdmac->ld_queue);
688 	cookie = dma_cookie_assign(tx);
689 	spin_unlock_irqrestore(&imxdma->lock, flags);
690 
691 	return cookie;
692 }
693 
694 static int imxdma_alloc_chan_resources(struct dma_chan *chan)
695 {
696 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
697 	struct imx_dma_data *data = chan->private;
698 
699 	if (data != NULL)
700 		imxdmac->dma_request = data->dma_request;
701 
702 	while (imxdmac->descs_allocated < IMXDMA_MAX_CHAN_DESCRIPTORS) {
703 		struct imxdma_desc *desc;
704 
705 		desc = kzalloc(sizeof(*desc), GFP_KERNEL);
706 		if (!desc)
707 			break;
708 		__memzero(&desc->desc, sizeof(struct dma_async_tx_descriptor));
709 		dma_async_tx_descriptor_init(&desc->desc, chan);
710 		desc->desc.tx_submit = imxdma_tx_submit;
711 		/* txd.flags will be overwritten in prep funcs */
712 		desc->desc.flags = DMA_CTRL_ACK;
713 		desc->status = DMA_SUCCESS;
714 
715 		list_add_tail(&desc->node, &imxdmac->ld_free);
716 		imxdmac->descs_allocated++;
717 	}
718 
719 	if (!imxdmac->descs_allocated)
720 		return -ENOMEM;
721 
722 	return imxdmac->descs_allocated;
723 }
724 
725 static void imxdma_free_chan_resources(struct dma_chan *chan)
726 {
727 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
728 	struct imxdma_engine *imxdma = imxdmac->imxdma;
729 	struct imxdma_desc *desc, *_desc;
730 	unsigned long flags;
731 
732 	spin_lock_irqsave(&imxdma->lock, flags);
733 
734 	imxdma_disable_hw(imxdmac);
735 	list_splice_tail_init(&imxdmac->ld_active, &imxdmac->ld_free);
736 	list_splice_tail_init(&imxdmac->ld_queue, &imxdmac->ld_free);
737 
738 	spin_unlock_irqrestore(&imxdma->lock, flags);
739 
740 	list_for_each_entry_safe(desc, _desc, &imxdmac->ld_free, node) {
741 		kfree(desc);
742 		imxdmac->descs_allocated--;
743 	}
744 	INIT_LIST_HEAD(&imxdmac->ld_free);
745 
746 	if (imxdmac->sg_list) {
747 		kfree(imxdmac->sg_list);
748 		imxdmac->sg_list = NULL;
749 	}
750 }
751 
752 static struct dma_async_tx_descriptor *imxdma_prep_slave_sg(
753 		struct dma_chan *chan, struct scatterlist *sgl,
754 		unsigned int sg_len, enum dma_transfer_direction direction,
755 		unsigned long flags, void *context)
756 {
757 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
758 	struct scatterlist *sg;
759 	int i, dma_length = 0;
760 	struct imxdma_desc *desc;
761 
762 	if (list_empty(&imxdmac->ld_free) ||
763 	    imxdma_chan_is_doing_cyclic(imxdmac))
764 		return NULL;
765 
766 	desc = list_first_entry(&imxdmac->ld_free, struct imxdma_desc, node);
767 
768 	for_each_sg(sgl, sg, sg_len, i) {
769 		dma_length += sg_dma_len(sg);
770 	}
771 
772 	switch (imxdmac->word_size) {
773 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
774 		if (sg_dma_len(sgl) & 3 || sgl->dma_address & 3)
775 			return NULL;
776 		break;
777 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
778 		if (sg_dma_len(sgl) & 1 || sgl->dma_address & 1)
779 			return NULL;
780 		break;
781 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
782 		break;
783 	default:
784 		return NULL;
785 	}
786 
787 	desc->type = IMXDMA_DESC_SLAVE_SG;
788 	desc->sg = sgl;
789 	desc->sgcount = sg_len;
790 	desc->len = dma_length;
791 	desc->direction = direction;
792 	if (direction == DMA_DEV_TO_MEM) {
793 		desc->src = imxdmac->per_address;
794 	} else {
795 		desc->dest = imxdmac->per_address;
796 	}
797 	desc->desc.callback = NULL;
798 	desc->desc.callback_param = NULL;
799 
800 	return &desc->desc;
801 }
802 
803 static struct dma_async_tx_descriptor *imxdma_prep_dma_cyclic(
804 		struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
805 		size_t period_len, enum dma_transfer_direction direction,
806 		unsigned long flags, void *context)
807 {
808 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
809 	struct imxdma_engine *imxdma = imxdmac->imxdma;
810 	struct imxdma_desc *desc;
811 	int i;
812 	unsigned int periods = buf_len / period_len;
813 
814 	dev_dbg(imxdma->dev, "%s channel: %d buf_len=%d period_len=%d\n",
815 			__func__, imxdmac->channel, buf_len, period_len);
816 
817 	if (list_empty(&imxdmac->ld_free) ||
818 	    imxdma_chan_is_doing_cyclic(imxdmac))
819 		return NULL;
820 
821 	desc = list_first_entry(&imxdmac->ld_free, struct imxdma_desc, node);
822 
823 	if (imxdmac->sg_list)
824 		kfree(imxdmac->sg_list);
825 
826 	imxdmac->sg_list = kcalloc(periods + 1,
827 			sizeof(struct scatterlist), GFP_KERNEL);
828 	if (!imxdmac->sg_list)
829 		return NULL;
830 
831 	sg_init_table(imxdmac->sg_list, periods);
832 
833 	for (i = 0; i < periods; i++) {
834 		imxdmac->sg_list[i].page_link = 0;
835 		imxdmac->sg_list[i].offset = 0;
836 		imxdmac->sg_list[i].dma_address = dma_addr;
837 		sg_dma_len(&imxdmac->sg_list[i]) = period_len;
838 		dma_addr += period_len;
839 	}
840 
841 	/* close the loop */
842 	imxdmac->sg_list[periods].offset = 0;
843 	sg_dma_len(&imxdmac->sg_list[periods]) = 0;
844 	imxdmac->sg_list[periods].page_link =
845 		((unsigned long)imxdmac->sg_list | 0x01) & ~0x02;
846 
847 	desc->type = IMXDMA_DESC_CYCLIC;
848 	desc->sg = imxdmac->sg_list;
849 	desc->sgcount = periods;
850 	desc->len = IMX_DMA_LENGTH_LOOP;
851 	desc->direction = direction;
852 	if (direction == DMA_DEV_TO_MEM) {
853 		desc->src = imxdmac->per_address;
854 	} else {
855 		desc->dest = imxdmac->per_address;
856 	}
857 	desc->desc.callback = NULL;
858 	desc->desc.callback_param = NULL;
859 
860 	return &desc->desc;
861 }
862 
863 static struct dma_async_tx_descriptor *imxdma_prep_dma_memcpy(
864 	struct dma_chan *chan, dma_addr_t dest,
865 	dma_addr_t src, size_t len, unsigned long flags)
866 {
867 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
868 	struct imxdma_engine *imxdma = imxdmac->imxdma;
869 	struct imxdma_desc *desc;
870 
871 	dev_dbg(imxdma->dev, "%s channel: %d src=0x%x dst=0x%x len=%d\n",
872 			__func__, imxdmac->channel, src, dest, len);
873 
874 	if (list_empty(&imxdmac->ld_free) ||
875 	    imxdma_chan_is_doing_cyclic(imxdmac))
876 		return NULL;
877 
878 	desc = list_first_entry(&imxdmac->ld_free, struct imxdma_desc, node);
879 
880 	desc->type = IMXDMA_DESC_MEMCPY;
881 	desc->src = src;
882 	desc->dest = dest;
883 	desc->len = len;
884 	desc->direction = DMA_MEM_TO_MEM;
885 	desc->config_port = IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR;
886 	desc->config_mem = IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR;
887 	desc->desc.callback = NULL;
888 	desc->desc.callback_param = NULL;
889 
890 	return &desc->desc;
891 }
892 
893 static struct dma_async_tx_descriptor *imxdma_prep_dma_interleaved(
894 	struct dma_chan *chan, struct dma_interleaved_template *xt,
895 	unsigned long flags)
896 {
897 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
898 	struct imxdma_engine *imxdma = imxdmac->imxdma;
899 	struct imxdma_desc *desc;
900 
901 	dev_dbg(imxdma->dev, "%s channel: %d src_start=0x%x dst_start=0x%x\n"
902 		"   src_sgl=%s dst_sgl=%s numf=%d frame_size=%d\n", __func__,
903 		imxdmac->channel, xt->src_start, xt->dst_start,
904 		xt->src_sgl ? "true" : "false", xt->dst_sgl ? "true" : "false",
905 		xt->numf, xt->frame_size);
906 
907 	if (list_empty(&imxdmac->ld_free) ||
908 	    imxdma_chan_is_doing_cyclic(imxdmac))
909 		return NULL;
910 
911 	if (xt->frame_size != 1 || xt->numf <= 0 || xt->dir != DMA_MEM_TO_MEM)
912 		return NULL;
913 
914 	desc = list_first_entry(&imxdmac->ld_free, struct imxdma_desc, node);
915 
916 	desc->type = IMXDMA_DESC_INTERLEAVED;
917 	desc->src = xt->src_start;
918 	desc->dest = xt->dst_start;
919 	desc->x = xt->sgl[0].size;
920 	desc->y = xt->numf;
921 	desc->w = xt->sgl[0].icg + desc->x;
922 	desc->len = desc->x * desc->y;
923 	desc->direction = DMA_MEM_TO_MEM;
924 	desc->config_port = IMX_DMA_MEMSIZE_32;
925 	desc->config_mem = IMX_DMA_MEMSIZE_32;
926 	if (xt->src_sgl)
927 		desc->config_mem |= IMX_DMA_TYPE_2D;
928 	if (xt->dst_sgl)
929 		desc->config_port |= IMX_DMA_TYPE_2D;
930 	desc->desc.callback = NULL;
931 	desc->desc.callback_param = NULL;
932 
933 	return &desc->desc;
934 }
935 
936 static void imxdma_issue_pending(struct dma_chan *chan)
937 {
938 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
939 	struct imxdma_engine *imxdma = imxdmac->imxdma;
940 	struct imxdma_desc *desc;
941 	unsigned long flags;
942 
943 	spin_lock_irqsave(&imxdma->lock, flags);
944 	if (list_empty(&imxdmac->ld_active) &&
945 	    !list_empty(&imxdmac->ld_queue)) {
946 		desc = list_first_entry(&imxdmac->ld_queue,
947 					struct imxdma_desc, node);
948 
949 		if (imxdma_xfer_desc(desc) < 0) {
950 			dev_warn(imxdma->dev,
951 				 "%s: channel: %d couldn't issue DMA xfer\n",
952 				 __func__, imxdmac->channel);
953 		} else {
954 			list_move_tail(imxdmac->ld_queue.next,
955 				       &imxdmac->ld_active);
956 		}
957 	}
958 	spin_unlock_irqrestore(&imxdma->lock, flags);
959 }
960 
961 static int __init imxdma_probe(struct platform_device *pdev)
962 	{
963 	struct imxdma_engine *imxdma;
964 	int ret, i;
965 
966 
967 	imxdma = kzalloc(sizeof(*imxdma), GFP_KERNEL);
968 	if (!imxdma)
969 		return -ENOMEM;
970 
971 	if (cpu_is_mx1()) {
972 		imxdma->base = MX1_IO_ADDRESS(MX1_DMA_BASE_ADDR);
973 	} else if (cpu_is_mx21()) {
974 		imxdma->base = MX21_IO_ADDRESS(MX21_DMA_BASE_ADDR);
975 	} else if (cpu_is_mx27()) {
976 		imxdma->base = MX27_IO_ADDRESS(MX27_DMA_BASE_ADDR);
977 	} else {
978 		kfree(imxdma);
979 		return 0;
980 	}
981 
982 	imxdma->dma_ipg = devm_clk_get(&pdev->dev, "ipg");
983 	if (IS_ERR(imxdma->dma_ipg)) {
984 		ret = PTR_ERR(imxdma->dma_ipg);
985 		goto err_clk;
986 	}
987 
988 	imxdma->dma_ahb = devm_clk_get(&pdev->dev, "ahb");
989 	if (IS_ERR(imxdma->dma_ahb)) {
990 		ret = PTR_ERR(imxdma->dma_ahb);
991 		goto err_clk;
992 	}
993 
994 	clk_prepare_enable(imxdma->dma_ipg);
995 	clk_prepare_enable(imxdma->dma_ahb);
996 
997 	/* reset DMA module */
998 	imx_dmav1_writel(imxdma, DCR_DRST, DMA_DCR);
999 
1000 	if (cpu_is_mx1()) {
1001 		ret = request_irq(MX1_DMA_INT, dma_irq_handler, 0, "DMA", imxdma);
1002 		if (ret) {
1003 			dev_warn(imxdma->dev, "Can't register IRQ for DMA\n");
1004 			goto err_enable;
1005 		}
1006 
1007 		ret = request_irq(MX1_DMA_ERR, imxdma_err_handler, 0, "DMA", imxdma);
1008 		if (ret) {
1009 			dev_warn(imxdma->dev, "Can't register ERRIRQ for DMA\n");
1010 			free_irq(MX1_DMA_INT, NULL);
1011 			goto err_enable;
1012 		}
1013 	}
1014 
1015 	/* enable DMA module */
1016 	imx_dmav1_writel(imxdma, DCR_DEN, DMA_DCR);
1017 
1018 	/* clear all interrupts */
1019 	imx_dmav1_writel(imxdma, (1 << IMX_DMA_CHANNELS) - 1, DMA_DISR);
1020 
1021 	/* disable interrupts */
1022 	imx_dmav1_writel(imxdma, (1 << IMX_DMA_CHANNELS) - 1, DMA_DIMR);
1023 
1024 	INIT_LIST_HEAD(&imxdma->dma_device.channels);
1025 
1026 	dma_cap_set(DMA_SLAVE, imxdma->dma_device.cap_mask);
1027 	dma_cap_set(DMA_CYCLIC, imxdma->dma_device.cap_mask);
1028 	dma_cap_set(DMA_MEMCPY, imxdma->dma_device.cap_mask);
1029 	dma_cap_set(DMA_INTERLEAVE, imxdma->dma_device.cap_mask);
1030 
1031 	/* Initialize 2D global parameters */
1032 	for (i = 0; i < IMX_DMA_2D_SLOTS; i++)
1033 		imxdma->slots_2d[i].count = 0;
1034 
1035 	spin_lock_init(&imxdma->lock);
1036 
1037 	/* Initialize channel parameters */
1038 	for (i = 0; i < IMX_DMA_CHANNELS; i++) {
1039 		struct imxdma_channel *imxdmac = &imxdma->channel[i];
1040 
1041 		if (cpu_is_mx21() || cpu_is_mx27()) {
1042 			ret = request_irq(MX2x_INT_DMACH0 + i,
1043 					dma_irq_handler, 0, "DMA", imxdma);
1044 			if (ret) {
1045 				dev_warn(imxdma->dev, "Can't register IRQ %d "
1046 					 "for DMA channel %d\n",
1047 					 MX2x_INT_DMACH0 + i, i);
1048 				goto err_init;
1049 			}
1050 			init_timer(&imxdmac->watchdog);
1051 			imxdmac->watchdog.function = &imxdma_watchdog;
1052 			imxdmac->watchdog.data = (unsigned long)imxdmac;
1053 		}
1054 
1055 		imxdmac->imxdma = imxdma;
1056 
1057 		INIT_LIST_HEAD(&imxdmac->ld_queue);
1058 		INIT_LIST_HEAD(&imxdmac->ld_free);
1059 		INIT_LIST_HEAD(&imxdmac->ld_active);
1060 
1061 		tasklet_init(&imxdmac->dma_tasklet, imxdma_tasklet,
1062 			     (unsigned long)imxdmac);
1063 		imxdmac->chan.device = &imxdma->dma_device;
1064 		dma_cookie_init(&imxdmac->chan);
1065 		imxdmac->channel = i;
1066 
1067 		/* Add the channel to the DMAC list */
1068 		list_add_tail(&imxdmac->chan.device_node,
1069 			      &imxdma->dma_device.channels);
1070 	}
1071 
1072 	imxdma->dev = &pdev->dev;
1073 	imxdma->dma_device.dev = &pdev->dev;
1074 
1075 	imxdma->dma_device.device_alloc_chan_resources = imxdma_alloc_chan_resources;
1076 	imxdma->dma_device.device_free_chan_resources = imxdma_free_chan_resources;
1077 	imxdma->dma_device.device_tx_status = imxdma_tx_status;
1078 	imxdma->dma_device.device_prep_slave_sg = imxdma_prep_slave_sg;
1079 	imxdma->dma_device.device_prep_dma_cyclic = imxdma_prep_dma_cyclic;
1080 	imxdma->dma_device.device_prep_dma_memcpy = imxdma_prep_dma_memcpy;
1081 	imxdma->dma_device.device_prep_interleaved_dma = imxdma_prep_dma_interleaved;
1082 	imxdma->dma_device.device_control = imxdma_control;
1083 	imxdma->dma_device.device_issue_pending = imxdma_issue_pending;
1084 
1085 	platform_set_drvdata(pdev, imxdma);
1086 
1087 	imxdma->dma_device.copy_align = 2; /* 2^2 = 4 bytes alignment */
1088 	imxdma->dma_device.dev->dma_parms = &imxdma->dma_parms;
1089 	dma_set_max_seg_size(imxdma->dma_device.dev, 0xffffff);
1090 
1091 	ret = dma_async_device_register(&imxdma->dma_device);
1092 	if (ret) {
1093 		dev_err(&pdev->dev, "unable to register\n");
1094 		goto err_init;
1095 	}
1096 
1097 	return 0;
1098 
1099 err_init:
1100 
1101 	if (cpu_is_mx21() || cpu_is_mx27()) {
1102 		while (--i >= 0)
1103 			free_irq(MX2x_INT_DMACH0 + i, NULL);
1104 	} else if cpu_is_mx1() {
1105 		free_irq(MX1_DMA_INT, NULL);
1106 		free_irq(MX1_DMA_ERR, NULL);
1107 	}
1108 err_enable:
1109 	clk_disable_unprepare(imxdma->dma_ipg);
1110 	clk_disable_unprepare(imxdma->dma_ahb);
1111 err_clk:
1112 	kfree(imxdma);
1113 	return ret;
1114 }
1115 
1116 static int __exit imxdma_remove(struct platform_device *pdev)
1117 {
1118 	struct imxdma_engine *imxdma = platform_get_drvdata(pdev);
1119 	int i;
1120 
1121         dma_async_device_unregister(&imxdma->dma_device);
1122 
1123 	if (cpu_is_mx21() || cpu_is_mx27()) {
1124 		for (i = 0; i < IMX_DMA_CHANNELS; i++)
1125 			free_irq(MX2x_INT_DMACH0 + i, NULL);
1126 	} else if cpu_is_mx1() {
1127 		free_irq(MX1_DMA_INT, NULL);
1128 		free_irq(MX1_DMA_ERR, NULL);
1129 	}
1130 
1131 	clk_disable_unprepare(imxdma->dma_ipg);
1132 	clk_disable_unprepare(imxdma->dma_ahb);
1133 	kfree(imxdma);
1134 
1135         return 0;
1136 }
1137 
1138 static struct platform_driver imxdma_driver = {
1139 	.driver		= {
1140 		.name	= "imx-dma",
1141 	},
1142 	.remove		= __exit_p(imxdma_remove),
1143 };
1144 
1145 static int __init imxdma_module_init(void)
1146 {
1147 	return platform_driver_probe(&imxdma_driver, imxdma_probe);
1148 }
1149 subsys_initcall(imxdma_module_init);
1150 
1151 MODULE_AUTHOR("Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>");
1152 MODULE_DESCRIPTION("i.MX dma driver");
1153 MODULE_LICENSE("GPL");
1154