xref: /openbmc/linux/drivers/dma/imx-dma.c (revision 3b64b188)
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 			return -EBUSY;
479 
480 		imxdma->slots_2d[slot].xsr = d->x;
481 		imxdma->slots_2d[slot].ysr = d->y;
482 		imxdma->slots_2d[slot].wsr = d->w;
483 		imxdma->slots_2d[slot].count++;
484 
485 		imxdmac->slot_2d = slot;
486 		imxdmac->enabled_2d = true;
487 		spin_unlock_irqrestore(&imxdma->lock, flags);
488 
489 		if (slot == IMX_DMA_2D_SLOT_A) {
490 			d->config_mem &= ~CCR_MSEL_B;
491 			d->config_port &= ~CCR_MSEL_B;
492 			imx_dmav1_writel(imxdma, d->x, DMA_XSRA);
493 			imx_dmav1_writel(imxdma, d->y, DMA_YSRA);
494 			imx_dmav1_writel(imxdma, d->w, DMA_WSRA);
495 		} else {
496 			d->config_mem |= CCR_MSEL_B;
497 			d->config_port |= CCR_MSEL_B;
498 			imx_dmav1_writel(imxdma, d->x, DMA_XSRB);
499 			imx_dmav1_writel(imxdma, d->y, DMA_YSRB);
500 			imx_dmav1_writel(imxdma, d->w, DMA_WSRB);
501 		}
502 		/*
503 		 * We fall-through here intentionally, since a 2D transfer is
504 		 * similar to MEMCPY just adding the 2D slot configuration.
505 		 */
506 	case IMXDMA_DESC_MEMCPY:
507 		imx_dmav1_writel(imxdma, d->src, DMA_SAR(imxdmac->channel));
508 		imx_dmav1_writel(imxdma, d->dest, DMA_DAR(imxdmac->channel));
509 		imx_dmav1_writel(imxdma, d->config_mem | (d->config_port << 2),
510 			 DMA_CCR(imxdmac->channel));
511 
512 		imx_dmav1_writel(imxdma, d->len, DMA_CNTR(imxdmac->channel));
513 
514 		dev_dbg(imxdma->dev, "%s channel: %d dest=0x%08x src=0x%08x "
515 			"dma_length=%d\n", __func__, imxdmac->channel,
516 			d->dest, d->src, d->len);
517 
518 		break;
519 	/* Cyclic transfer is the same as slave_sg with special sg configuration. */
520 	case IMXDMA_DESC_CYCLIC:
521 	case IMXDMA_DESC_SLAVE_SG:
522 		if (d->direction == DMA_DEV_TO_MEM) {
523 			imx_dmav1_writel(imxdma, imxdmac->per_address,
524 					 DMA_SAR(imxdmac->channel));
525 			imx_dmav1_writel(imxdma, imxdmac->ccr_from_device,
526 					 DMA_CCR(imxdmac->channel));
527 
528 			dev_dbg(imxdma->dev, "%s channel: %d sg=%p sgcount=%d "
529 				"total length=%d dev_addr=0x%08x (dev2mem)\n",
530 				__func__, imxdmac->channel, d->sg, d->sgcount,
531 				d->len, imxdmac->per_address);
532 		} else if (d->direction == DMA_MEM_TO_DEV) {
533 			imx_dmav1_writel(imxdma, imxdmac->per_address,
534 					 DMA_DAR(imxdmac->channel));
535 			imx_dmav1_writel(imxdma, imxdmac->ccr_to_device,
536 					 DMA_CCR(imxdmac->channel));
537 
538 			dev_dbg(imxdma->dev, "%s channel: %d sg=%p sgcount=%d "
539 				"total length=%d dev_addr=0x%08x (mem2dev)\n",
540 				__func__, imxdmac->channel, d->sg, d->sgcount,
541 				d->len, imxdmac->per_address);
542 		} else {
543 			dev_err(imxdma->dev, "%s channel: %d bad dma mode\n",
544 				__func__, imxdmac->channel);
545 			return -EINVAL;
546 		}
547 
548 		imxdma_sg_next(d);
549 
550 		break;
551 	default:
552 		return -EINVAL;
553 	}
554 	imxdma_enable_hw(d);
555 	return 0;
556 }
557 
558 static void imxdma_tasklet(unsigned long data)
559 {
560 	struct imxdma_channel *imxdmac = (void *)data;
561 	struct imxdma_engine *imxdma = imxdmac->imxdma;
562 	struct imxdma_desc *desc;
563 
564 	spin_lock(&imxdma->lock);
565 
566 	if (list_empty(&imxdmac->ld_active)) {
567 		/* Someone might have called terminate all */
568 		goto out;
569 	}
570 	desc = list_first_entry(&imxdmac->ld_active, struct imxdma_desc, node);
571 
572 	if (desc->desc.callback)
573 		desc->desc.callback(desc->desc.callback_param);
574 
575 	/* If we are dealing with a cyclic descriptor, keep it on ld_active
576 	 * and dont mark the descriptor as complete.
577 	 * Only in non-cyclic cases it would be marked as complete
578 	 */
579 	if (imxdma_chan_is_doing_cyclic(imxdmac))
580 		goto out;
581 	else
582 		dma_cookie_complete(&desc->desc);
583 
584 	/* Free 2D slot if it was an interleaved transfer */
585 	if (imxdmac->enabled_2d) {
586 		imxdma->slots_2d[imxdmac->slot_2d].count--;
587 		imxdmac->enabled_2d = false;
588 	}
589 
590 	list_move_tail(imxdmac->ld_active.next, &imxdmac->ld_free);
591 
592 	if (!list_empty(&imxdmac->ld_queue)) {
593 		desc = list_first_entry(&imxdmac->ld_queue, struct imxdma_desc,
594 					node);
595 		list_move_tail(imxdmac->ld_queue.next, &imxdmac->ld_active);
596 		if (imxdma_xfer_desc(desc) < 0)
597 			dev_warn(imxdma->dev, "%s: channel: %d couldn't xfer desc\n",
598 				 __func__, imxdmac->channel);
599 	}
600 out:
601 	spin_unlock(&imxdma->lock);
602 }
603 
604 static int imxdma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
605 		unsigned long arg)
606 {
607 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
608 	struct dma_slave_config *dmaengine_cfg = (void *)arg;
609 	struct imxdma_engine *imxdma = imxdmac->imxdma;
610 	unsigned long flags;
611 	unsigned int mode = 0;
612 
613 	switch (cmd) {
614 	case DMA_TERMINATE_ALL:
615 		imxdma_disable_hw(imxdmac);
616 
617 		spin_lock_irqsave(&imxdma->lock, flags);
618 		list_splice_tail_init(&imxdmac->ld_active, &imxdmac->ld_free);
619 		list_splice_tail_init(&imxdmac->ld_queue, &imxdmac->ld_free);
620 		spin_unlock_irqrestore(&imxdma->lock, flags);
621 		return 0;
622 	case DMA_SLAVE_CONFIG:
623 		if (dmaengine_cfg->direction == DMA_DEV_TO_MEM) {
624 			imxdmac->per_address = dmaengine_cfg->src_addr;
625 			imxdmac->watermark_level = dmaengine_cfg->src_maxburst;
626 			imxdmac->word_size = dmaengine_cfg->src_addr_width;
627 		} else {
628 			imxdmac->per_address = dmaengine_cfg->dst_addr;
629 			imxdmac->watermark_level = dmaengine_cfg->dst_maxburst;
630 			imxdmac->word_size = dmaengine_cfg->dst_addr_width;
631 		}
632 
633 		switch (imxdmac->word_size) {
634 		case DMA_SLAVE_BUSWIDTH_1_BYTE:
635 			mode = IMX_DMA_MEMSIZE_8;
636 			break;
637 		case DMA_SLAVE_BUSWIDTH_2_BYTES:
638 			mode = IMX_DMA_MEMSIZE_16;
639 			break;
640 		default:
641 		case DMA_SLAVE_BUSWIDTH_4_BYTES:
642 			mode = IMX_DMA_MEMSIZE_32;
643 			break;
644 		}
645 
646 		imxdmac->hw_chaining = 1;
647 		if (!imxdma_hw_chain(imxdmac))
648 			return -EINVAL;
649 		imxdmac->ccr_from_device = (mode | IMX_DMA_TYPE_FIFO) |
650 			((IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR) << 2) |
651 			CCR_REN;
652 		imxdmac->ccr_to_device =
653 			(IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR) |
654 			((mode | IMX_DMA_TYPE_FIFO) << 2) | CCR_REN;
655 		imx_dmav1_writel(imxdma, imxdmac->dma_request,
656 				 DMA_RSSR(imxdmac->channel));
657 
658 		/* Set burst length */
659 		imx_dmav1_writel(imxdma, imxdmac->watermark_level *
660 				imxdmac->word_size, DMA_BLR(imxdmac->channel));
661 
662 		return 0;
663 	default:
664 		return -ENOSYS;
665 	}
666 
667 	return -EINVAL;
668 }
669 
670 static enum dma_status imxdma_tx_status(struct dma_chan *chan,
671 					    dma_cookie_t cookie,
672 					    struct dma_tx_state *txstate)
673 {
674 	return dma_cookie_status(chan, cookie, txstate);
675 }
676 
677 static dma_cookie_t imxdma_tx_submit(struct dma_async_tx_descriptor *tx)
678 {
679 	struct imxdma_channel *imxdmac = to_imxdma_chan(tx->chan);
680 	struct imxdma_engine *imxdma = imxdmac->imxdma;
681 	dma_cookie_t cookie;
682 	unsigned long flags;
683 
684 	spin_lock_irqsave(&imxdma->lock, flags);
685 	list_move_tail(imxdmac->ld_free.next, &imxdmac->ld_queue);
686 	cookie = dma_cookie_assign(tx);
687 	spin_unlock_irqrestore(&imxdma->lock, flags);
688 
689 	return cookie;
690 }
691 
692 static int imxdma_alloc_chan_resources(struct dma_chan *chan)
693 {
694 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
695 	struct imx_dma_data *data = chan->private;
696 
697 	if (data != NULL)
698 		imxdmac->dma_request = data->dma_request;
699 
700 	while (imxdmac->descs_allocated < IMXDMA_MAX_CHAN_DESCRIPTORS) {
701 		struct imxdma_desc *desc;
702 
703 		desc = kzalloc(sizeof(*desc), GFP_KERNEL);
704 		if (!desc)
705 			break;
706 		__memzero(&desc->desc, sizeof(struct dma_async_tx_descriptor));
707 		dma_async_tx_descriptor_init(&desc->desc, chan);
708 		desc->desc.tx_submit = imxdma_tx_submit;
709 		/* txd.flags will be overwritten in prep funcs */
710 		desc->desc.flags = DMA_CTRL_ACK;
711 		desc->status = DMA_SUCCESS;
712 
713 		list_add_tail(&desc->node, &imxdmac->ld_free);
714 		imxdmac->descs_allocated++;
715 	}
716 
717 	if (!imxdmac->descs_allocated)
718 		return -ENOMEM;
719 
720 	return imxdmac->descs_allocated;
721 }
722 
723 static void imxdma_free_chan_resources(struct dma_chan *chan)
724 {
725 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
726 	struct imxdma_engine *imxdma = imxdmac->imxdma;
727 	struct imxdma_desc *desc, *_desc;
728 	unsigned long flags;
729 
730 	spin_lock_irqsave(&imxdma->lock, flags);
731 
732 	imxdma_disable_hw(imxdmac);
733 	list_splice_tail_init(&imxdmac->ld_active, &imxdmac->ld_free);
734 	list_splice_tail_init(&imxdmac->ld_queue, &imxdmac->ld_free);
735 
736 	spin_unlock_irqrestore(&imxdma->lock, flags);
737 
738 	list_for_each_entry_safe(desc, _desc, &imxdmac->ld_free, node) {
739 		kfree(desc);
740 		imxdmac->descs_allocated--;
741 	}
742 	INIT_LIST_HEAD(&imxdmac->ld_free);
743 
744 	if (imxdmac->sg_list) {
745 		kfree(imxdmac->sg_list);
746 		imxdmac->sg_list = NULL;
747 	}
748 }
749 
750 static struct dma_async_tx_descriptor *imxdma_prep_slave_sg(
751 		struct dma_chan *chan, struct scatterlist *sgl,
752 		unsigned int sg_len, enum dma_transfer_direction direction,
753 		unsigned long flags, void *context)
754 {
755 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
756 	struct scatterlist *sg;
757 	int i, dma_length = 0;
758 	struct imxdma_desc *desc;
759 
760 	if (list_empty(&imxdmac->ld_free) ||
761 	    imxdma_chan_is_doing_cyclic(imxdmac))
762 		return NULL;
763 
764 	desc = list_first_entry(&imxdmac->ld_free, struct imxdma_desc, node);
765 
766 	for_each_sg(sgl, sg, sg_len, i) {
767 		dma_length += sg_dma_len(sg);
768 	}
769 
770 	switch (imxdmac->word_size) {
771 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
772 		if (sg_dma_len(sgl) & 3 || sgl->dma_address & 3)
773 			return NULL;
774 		break;
775 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
776 		if (sg_dma_len(sgl) & 1 || sgl->dma_address & 1)
777 			return NULL;
778 		break;
779 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
780 		break;
781 	default:
782 		return NULL;
783 	}
784 
785 	desc->type = IMXDMA_DESC_SLAVE_SG;
786 	desc->sg = sgl;
787 	desc->sgcount = sg_len;
788 	desc->len = dma_length;
789 	desc->direction = direction;
790 	if (direction == DMA_DEV_TO_MEM) {
791 		desc->src = imxdmac->per_address;
792 	} else {
793 		desc->dest = imxdmac->per_address;
794 	}
795 	desc->desc.callback = NULL;
796 	desc->desc.callback_param = NULL;
797 
798 	return &desc->desc;
799 }
800 
801 static struct dma_async_tx_descriptor *imxdma_prep_dma_cyclic(
802 		struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
803 		size_t period_len, enum dma_transfer_direction direction,
804 		void *context)
805 {
806 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
807 	struct imxdma_engine *imxdma = imxdmac->imxdma;
808 	struct imxdma_desc *desc;
809 	int i;
810 	unsigned int periods = buf_len / period_len;
811 
812 	dev_dbg(imxdma->dev, "%s channel: %d buf_len=%d period_len=%d\n",
813 			__func__, imxdmac->channel, buf_len, period_len);
814 
815 	if (list_empty(&imxdmac->ld_free) ||
816 	    imxdma_chan_is_doing_cyclic(imxdmac))
817 		return NULL;
818 
819 	desc = list_first_entry(&imxdmac->ld_free, struct imxdma_desc, node);
820 
821 	if (imxdmac->sg_list)
822 		kfree(imxdmac->sg_list);
823 
824 	imxdmac->sg_list = kcalloc(periods + 1,
825 			sizeof(struct scatterlist), GFP_KERNEL);
826 	if (!imxdmac->sg_list)
827 		return NULL;
828 
829 	sg_init_table(imxdmac->sg_list, periods);
830 
831 	for (i = 0; i < periods; i++) {
832 		imxdmac->sg_list[i].page_link = 0;
833 		imxdmac->sg_list[i].offset = 0;
834 		imxdmac->sg_list[i].dma_address = dma_addr;
835 		sg_dma_len(&imxdmac->sg_list[i]) = period_len;
836 		dma_addr += period_len;
837 	}
838 
839 	/* close the loop */
840 	imxdmac->sg_list[periods].offset = 0;
841 	sg_dma_len(&imxdmac->sg_list[periods]) = 0;
842 	imxdmac->sg_list[periods].page_link =
843 		((unsigned long)imxdmac->sg_list | 0x01) & ~0x02;
844 
845 	desc->type = IMXDMA_DESC_CYCLIC;
846 	desc->sg = imxdmac->sg_list;
847 	desc->sgcount = periods;
848 	desc->len = IMX_DMA_LENGTH_LOOP;
849 	desc->direction = direction;
850 	if (direction == DMA_DEV_TO_MEM) {
851 		desc->src = imxdmac->per_address;
852 	} else {
853 		desc->dest = imxdmac->per_address;
854 	}
855 	desc->desc.callback = NULL;
856 	desc->desc.callback_param = NULL;
857 
858 	return &desc->desc;
859 }
860 
861 static struct dma_async_tx_descriptor *imxdma_prep_dma_memcpy(
862 	struct dma_chan *chan, dma_addr_t dest,
863 	dma_addr_t src, size_t len, unsigned long flags)
864 {
865 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
866 	struct imxdma_engine *imxdma = imxdmac->imxdma;
867 	struct imxdma_desc *desc;
868 
869 	dev_dbg(imxdma->dev, "%s channel: %d src=0x%x dst=0x%x len=%d\n",
870 			__func__, imxdmac->channel, src, dest, len);
871 
872 	if (list_empty(&imxdmac->ld_free) ||
873 	    imxdma_chan_is_doing_cyclic(imxdmac))
874 		return NULL;
875 
876 	desc = list_first_entry(&imxdmac->ld_free, struct imxdma_desc, node);
877 
878 	desc->type = IMXDMA_DESC_MEMCPY;
879 	desc->src = src;
880 	desc->dest = dest;
881 	desc->len = len;
882 	desc->direction = DMA_MEM_TO_MEM;
883 	desc->config_port = IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR;
884 	desc->config_mem = IMX_DMA_MEMSIZE_32 | IMX_DMA_TYPE_LINEAR;
885 	desc->desc.callback = NULL;
886 	desc->desc.callback_param = NULL;
887 
888 	return &desc->desc;
889 }
890 
891 static struct dma_async_tx_descriptor *imxdma_prep_dma_interleaved(
892 	struct dma_chan *chan, struct dma_interleaved_template *xt,
893 	unsigned long flags)
894 {
895 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
896 	struct imxdma_engine *imxdma = imxdmac->imxdma;
897 	struct imxdma_desc *desc;
898 
899 	dev_dbg(imxdma->dev, "%s channel: %d src_start=0x%x dst_start=0x%x\n"
900 		"   src_sgl=%s dst_sgl=%s numf=%d frame_size=%d\n", __func__,
901 		imxdmac->channel, xt->src_start, xt->dst_start,
902 		xt->src_sgl ? "true" : "false", xt->dst_sgl ? "true" : "false",
903 		xt->numf, xt->frame_size);
904 
905 	if (list_empty(&imxdmac->ld_free) ||
906 	    imxdma_chan_is_doing_cyclic(imxdmac))
907 		return NULL;
908 
909 	if (xt->frame_size != 1 || xt->numf <= 0 || xt->dir != DMA_MEM_TO_MEM)
910 		return NULL;
911 
912 	desc = list_first_entry(&imxdmac->ld_free, struct imxdma_desc, node);
913 
914 	desc->type = IMXDMA_DESC_INTERLEAVED;
915 	desc->src = xt->src_start;
916 	desc->dest = xt->dst_start;
917 	desc->x = xt->sgl[0].size;
918 	desc->y = xt->numf;
919 	desc->w = xt->sgl[0].icg + desc->x;
920 	desc->len = desc->x * desc->y;
921 	desc->direction = DMA_MEM_TO_MEM;
922 	desc->config_port = IMX_DMA_MEMSIZE_32;
923 	desc->config_mem = IMX_DMA_MEMSIZE_32;
924 	if (xt->src_sgl)
925 		desc->config_mem |= IMX_DMA_TYPE_2D;
926 	if (xt->dst_sgl)
927 		desc->config_port |= IMX_DMA_TYPE_2D;
928 	desc->desc.callback = NULL;
929 	desc->desc.callback_param = NULL;
930 
931 	return &desc->desc;
932 }
933 
934 static void imxdma_issue_pending(struct dma_chan *chan)
935 {
936 	struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
937 	struct imxdma_engine *imxdma = imxdmac->imxdma;
938 	struct imxdma_desc *desc;
939 	unsigned long flags;
940 
941 	spin_lock_irqsave(&imxdma->lock, flags);
942 	if (list_empty(&imxdmac->ld_active) &&
943 	    !list_empty(&imxdmac->ld_queue)) {
944 		desc = list_first_entry(&imxdmac->ld_queue,
945 					struct imxdma_desc, node);
946 
947 		if (imxdma_xfer_desc(desc) < 0) {
948 			dev_warn(imxdma->dev,
949 				 "%s: channel: %d couldn't issue DMA xfer\n",
950 				 __func__, imxdmac->channel);
951 		} else {
952 			list_move_tail(imxdmac->ld_queue.next,
953 				       &imxdmac->ld_active);
954 		}
955 	}
956 	spin_unlock_irqrestore(&imxdma->lock, flags);
957 }
958 
959 static int __init imxdma_probe(struct platform_device *pdev)
960 	{
961 	struct imxdma_engine *imxdma;
962 	int ret, i;
963 
964 
965 	imxdma = kzalloc(sizeof(*imxdma), GFP_KERNEL);
966 	if (!imxdma)
967 		return -ENOMEM;
968 
969 	if (cpu_is_mx1()) {
970 		imxdma->base = MX1_IO_ADDRESS(MX1_DMA_BASE_ADDR);
971 	} else if (cpu_is_mx21()) {
972 		imxdma->base = MX21_IO_ADDRESS(MX21_DMA_BASE_ADDR);
973 	} else if (cpu_is_mx27()) {
974 		imxdma->base = MX27_IO_ADDRESS(MX27_DMA_BASE_ADDR);
975 	} else {
976 		kfree(imxdma);
977 		return 0;
978 	}
979 
980 	imxdma->dma_ipg = devm_clk_get(&pdev->dev, "ipg");
981 	if (IS_ERR(imxdma->dma_ipg)) {
982 		ret = PTR_ERR(imxdma->dma_ipg);
983 		goto err_clk;
984 	}
985 
986 	imxdma->dma_ahb = devm_clk_get(&pdev->dev, "ahb");
987 	if (IS_ERR(imxdma->dma_ahb)) {
988 		ret = PTR_ERR(imxdma->dma_ahb);
989 		goto err_clk;
990 	}
991 
992 	clk_prepare_enable(imxdma->dma_ipg);
993 	clk_prepare_enable(imxdma->dma_ahb);
994 
995 	/* reset DMA module */
996 	imx_dmav1_writel(imxdma, DCR_DRST, DMA_DCR);
997 
998 	if (cpu_is_mx1()) {
999 		ret = request_irq(MX1_DMA_INT, dma_irq_handler, 0, "DMA", imxdma);
1000 		if (ret) {
1001 			dev_warn(imxdma->dev, "Can't register IRQ for DMA\n");
1002 			goto err_enable;
1003 		}
1004 
1005 		ret = request_irq(MX1_DMA_ERR, imxdma_err_handler, 0, "DMA", imxdma);
1006 		if (ret) {
1007 			dev_warn(imxdma->dev, "Can't register ERRIRQ for DMA\n");
1008 			free_irq(MX1_DMA_INT, NULL);
1009 			goto err_enable;
1010 		}
1011 	}
1012 
1013 	/* enable DMA module */
1014 	imx_dmav1_writel(imxdma, DCR_DEN, DMA_DCR);
1015 
1016 	/* clear all interrupts */
1017 	imx_dmav1_writel(imxdma, (1 << IMX_DMA_CHANNELS) - 1, DMA_DISR);
1018 
1019 	/* disable interrupts */
1020 	imx_dmav1_writel(imxdma, (1 << IMX_DMA_CHANNELS) - 1, DMA_DIMR);
1021 
1022 	INIT_LIST_HEAD(&imxdma->dma_device.channels);
1023 
1024 	dma_cap_set(DMA_SLAVE, imxdma->dma_device.cap_mask);
1025 	dma_cap_set(DMA_CYCLIC, imxdma->dma_device.cap_mask);
1026 	dma_cap_set(DMA_MEMCPY, imxdma->dma_device.cap_mask);
1027 	dma_cap_set(DMA_INTERLEAVE, imxdma->dma_device.cap_mask);
1028 
1029 	/* Initialize 2D global parameters */
1030 	for (i = 0; i < IMX_DMA_2D_SLOTS; i++)
1031 		imxdma->slots_2d[i].count = 0;
1032 
1033 	spin_lock_init(&imxdma->lock);
1034 
1035 	/* Initialize channel parameters */
1036 	for (i = 0; i < IMX_DMA_CHANNELS; i++) {
1037 		struct imxdma_channel *imxdmac = &imxdma->channel[i];
1038 
1039 		if (cpu_is_mx21() || cpu_is_mx27()) {
1040 			ret = request_irq(MX2x_INT_DMACH0 + i,
1041 					dma_irq_handler, 0, "DMA", imxdma);
1042 			if (ret) {
1043 				dev_warn(imxdma->dev, "Can't register IRQ %d "
1044 					 "for DMA channel %d\n",
1045 					 MX2x_INT_DMACH0 + i, i);
1046 				goto err_init;
1047 			}
1048 			init_timer(&imxdmac->watchdog);
1049 			imxdmac->watchdog.function = &imxdma_watchdog;
1050 			imxdmac->watchdog.data = (unsigned long)imxdmac;
1051 		}
1052 
1053 		imxdmac->imxdma = imxdma;
1054 
1055 		INIT_LIST_HEAD(&imxdmac->ld_queue);
1056 		INIT_LIST_HEAD(&imxdmac->ld_free);
1057 		INIT_LIST_HEAD(&imxdmac->ld_active);
1058 
1059 		tasklet_init(&imxdmac->dma_tasklet, imxdma_tasklet,
1060 			     (unsigned long)imxdmac);
1061 		imxdmac->chan.device = &imxdma->dma_device;
1062 		dma_cookie_init(&imxdmac->chan);
1063 		imxdmac->channel = i;
1064 
1065 		/* Add the channel to the DMAC list */
1066 		list_add_tail(&imxdmac->chan.device_node,
1067 			      &imxdma->dma_device.channels);
1068 	}
1069 
1070 	imxdma->dev = &pdev->dev;
1071 	imxdma->dma_device.dev = &pdev->dev;
1072 
1073 	imxdma->dma_device.device_alloc_chan_resources = imxdma_alloc_chan_resources;
1074 	imxdma->dma_device.device_free_chan_resources = imxdma_free_chan_resources;
1075 	imxdma->dma_device.device_tx_status = imxdma_tx_status;
1076 	imxdma->dma_device.device_prep_slave_sg = imxdma_prep_slave_sg;
1077 	imxdma->dma_device.device_prep_dma_cyclic = imxdma_prep_dma_cyclic;
1078 	imxdma->dma_device.device_prep_dma_memcpy = imxdma_prep_dma_memcpy;
1079 	imxdma->dma_device.device_prep_interleaved_dma = imxdma_prep_dma_interleaved;
1080 	imxdma->dma_device.device_control = imxdma_control;
1081 	imxdma->dma_device.device_issue_pending = imxdma_issue_pending;
1082 
1083 	platform_set_drvdata(pdev, imxdma);
1084 
1085 	imxdma->dma_device.copy_align = 2; /* 2^2 = 4 bytes alignment */
1086 	imxdma->dma_device.dev->dma_parms = &imxdma->dma_parms;
1087 	dma_set_max_seg_size(imxdma->dma_device.dev, 0xffffff);
1088 
1089 	ret = dma_async_device_register(&imxdma->dma_device);
1090 	if (ret) {
1091 		dev_err(&pdev->dev, "unable to register\n");
1092 		goto err_init;
1093 	}
1094 
1095 	return 0;
1096 
1097 err_init:
1098 
1099 	if (cpu_is_mx21() || cpu_is_mx27()) {
1100 		while (--i >= 0)
1101 			free_irq(MX2x_INT_DMACH0 + i, NULL);
1102 	} else if cpu_is_mx1() {
1103 		free_irq(MX1_DMA_INT, NULL);
1104 		free_irq(MX1_DMA_ERR, NULL);
1105 	}
1106 err_enable:
1107 	clk_disable_unprepare(imxdma->dma_ipg);
1108 	clk_disable_unprepare(imxdma->dma_ahb);
1109 err_clk:
1110 	kfree(imxdma);
1111 	return ret;
1112 }
1113 
1114 static int __exit imxdma_remove(struct platform_device *pdev)
1115 {
1116 	struct imxdma_engine *imxdma = platform_get_drvdata(pdev);
1117 	int i;
1118 
1119         dma_async_device_unregister(&imxdma->dma_device);
1120 
1121 	if (cpu_is_mx21() || cpu_is_mx27()) {
1122 		for (i = 0; i < IMX_DMA_CHANNELS; i++)
1123 			free_irq(MX2x_INT_DMACH0 + i, NULL);
1124 	} else if cpu_is_mx1() {
1125 		free_irq(MX1_DMA_INT, NULL);
1126 		free_irq(MX1_DMA_ERR, NULL);
1127 	}
1128 
1129 	clk_disable_unprepare(imxdma->dma_ipg);
1130 	clk_disable_unprepare(imxdma->dma_ahb);
1131 	kfree(imxdma);
1132 
1133         return 0;
1134 }
1135 
1136 static struct platform_driver imxdma_driver = {
1137 	.driver		= {
1138 		.name	= "imx-dma",
1139 	},
1140 	.remove		= __exit_p(imxdma_remove),
1141 };
1142 
1143 static int __init imxdma_module_init(void)
1144 {
1145 	return platform_driver_probe(&imxdma_driver, imxdma_probe);
1146 }
1147 subsys_initcall(imxdma_module_init);
1148 
1149 MODULE_AUTHOR("Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>");
1150 MODULE_DESCRIPTION("i.MX dma driver");
1151 MODULE_LICENSE("GPL");
1152