xref: /openbmc/linux/drivers/dma/mpc512x_dma.c (revision 79f08d9e)
1 /*
2  * Copyright (C) Freescale Semicondutor, Inc. 2007, 2008.
3  * Copyright (C) Semihalf 2009
4  * Copyright (C) Ilya Yanok, Emcraft Systems 2010
5  *
6  * Written by Piotr Ziecik <kosmo@semihalf.com>. Hardware description
7  * (defines, structures and comments) was taken from MPC5121 DMA driver
8  * written by Hongjun Chen <hong-jun.chen@freescale.com>.
9  *
10  * Approved as OSADL project by a majority of OSADL members and funded
11  * by OSADL membership fees in 2009;  for details see www.osadl.org.
12  *
13  * This program is free software; you can redistribute it and/or modify it
14  * under the terms of the GNU General Public License as published by the Free
15  * Software Foundation; either version 2 of the License, or (at your option)
16  * any later version.
17  *
18  * This program is distributed in the hope that it will be useful, but WITHOUT
19  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
20  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
21  * more details.
22  *
23  * You should have received a copy of the GNU General Public License along with
24  * this program; if not, write to the Free Software Foundation, Inc., 59
25  * Temple Place - Suite 330, Boston, MA  02111-1307, USA.
26  *
27  * The full GNU General Public License is included in this distribution in the
28  * file called COPYING.
29  */
30 
31 /*
32  * This is initial version of MPC5121 DMA driver. Only memory to memory
33  * transfers are supported (tested using dmatest module).
34  */
35 
36 #include <linux/module.h>
37 #include <linux/dmaengine.h>
38 #include <linux/dma-mapping.h>
39 #include <linux/interrupt.h>
40 #include <linux/io.h>
41 #include <linux/slab.h>
42 #include <linux/of_address.h>
43 #include <linux/of_device.h>
44 #include <linux/of_irq.h>
45 #include <linux/of_platform.h>
46 
47 #include <linux/random.h>
48 
49 #include "dmaengine.h"
50 
51 /* Number of DMA Transfer descriptors allocated per channel */
52 #define MPC_DMA_DESCRIPTORS	64
53 
54 /* Macro definitions */
55 #define MPC_DMA_CHANNELS	64
56 #define MPC_DMA_TCD_OFFSET	0x1000
57 
58 /* Arbitration mode of group and channel */
59 #define MPC_DMA_DMACR_EDCG	(1 << 31)
60 #define MPC_DMA_DMACR_ERGA	(1 << 3)
61 #define MPC_DMA_DMACR_ERCA	(1 << 2)
62 
63 /* Error codes */
64 #define MPC_DMA_DMAES_VLD	(1 << 31)
65 #define MPC_DMA_DMAES_GPE	(1 << 15)
66 #define MPC_DMA_DMAES_CPE	(1 << 14)
67 #define MPC_DMA_DMAES_ERRCHN(err) \
68 				(((err) >> 8) & 0x3f)
69 #define MPC_DMA_DMAES_SAE	(1 << 7)
70 #define MPC_DMA_DMAES_SOE	(1 << 6)
71 #define MPC_DMA_DMAES_DAE	(1 << 5)
72 #define MPC_DMA_DMAES_DOE	(1 << 4)
73 #define MPC_DMA_DMAES_NCE	(1 << 3)
74 #define MPC_DMA_DMAES_SGE	(1 << 2)
75 #define MPC_DMA_DMAES_SBE	(1 << 1)
76 #define MPC_DMA_DMAES_DBE	(1 << 0)
77 
78 #define MPC_DMA_DMAGPOR_SNOOP_ENABLE	(1 << 6)
79 
80 #define MPC_DMA_TSIZE_1		0x00
81 #define MPC_DMA_TSIZE_2		0x01
82 #define MPC_DMA_TSIZE_4		0x02
83 #define MPC_DMA_TSIZE_16	0x04
84 #define MPC_DMA_TSIZE_32	0x05
85 
86 /* MPC5121 DMA engine registers */
87 struct __attribute__ ((__packed__)) mpc_dma_regs {
88 	/* 0x00 */
89 	u32 dmacr;		/* DMA control register */
90 	u32 dmaes;		/* DMA error status */
91 	/* 0x08 */
92 	u32 dmaerqh;		/* DMA enable request high(channels 63~32) */
93 	u32 dmaerql;		/* DMA enable request low(channels 31~0) */
94 	u32 dmaeeih;		/* DMA enable error interrupt high(ch63~32) */
95 	u32 dmaeeil;		/* DMA enable error interrupt low(ch31~0) */
96 	/* 0x18 */
97 	u8 dmaserq;		/* DMA set enable request */
98 	u8 dmacerq;		/* DMA clear enable request */
99 	u8 dmaseei;		/* DMA set enable error interrupt */
100 	u8 dmaceei;		/* DMA clear enable error interrupt */
101 	/* 0x1c */
102 	u8 dmacint;		/* DMA clear interrupt request */
103 	u8 dmacerr;		/* DMA clear error */
104 	u8 dmassrt;		/* DMA set start bit */
105 	u8 dmacdne;		/* DMA clear DONE status bit */
106 	/* 0x20 */
107 	u32 dmainth;		/* DMA interrupt request high(ch63~32) */
108 	u32 dmaintl;		/* DMA interrupt request low(ch31~0) */
109 	u32 dmaerrh;		/* DMA error high(ch63~32) */
110 	u32 dmaerrl;		/* DMA error low(ch31~0) */
111 	/* 0x30 */
112 	u32 dmahrsh;		/* DMA hw request status high(ch63~32) */
113 	u32 dmahrsl;		/* DMA hardware request status low(ch31~0) */
114 	union {
115 		u32 dmaihsa;	/* DMA interrupt high select AXE(ch63~32) */
116 		u32 dmagpor;	/* (General purpose register on MPC8308) */
117 	};
118 	u32 dmailsa;		/* DMA interrupt low select AXE(ch31~0) */
119 	/* 0x40 ~ 0xff */
120 	u32 reserve0[48];	/* Reserved */
121 	/* 0x100 */
122 	u8 dchpri[MPC_DMA_CHANNELS];
123 	/* DMA channels(0~63) priority */
124 };
125 
126 struct __attribute__ ((__packed__)) mpc_dma_tcd {
127 	/* 0x00 */
128 	u32 saddr;		/* Source address */
129 
130 	u32 smod:5;		/* Source address modulo */
131 	u32 ssize:3;		/* Source data transfer size */
132 	u32 dmod:5;		/* Destination address modulo */
133 	u32 dsize:3;		/* Destination data transfer size */
134 	u32 soff:16;		/* Signed source address offset */
135 
136 	/* 0x08 */
137 	u32 nbytes;		/* Inner "minor" byte count */
138 	u32 slast;		/* Last source address adjustment */
139 	u32 daddr;		/* Destination address */
140 
141 	/* 0x14 */
142 	u32 citer_elink:1;	/* Enable channel-to-channel linking on
143 				 * minor loop complete
144 				 */
145 	u32 citer_linkch:6;	/* Link channel for minor loop complete */
146 	u32 citer:9;		/* Current "major" iteration count */
147 	u32 doff:16;		/* Signed destination address offset */
148 
149 	/* 0x18 */
150 	u32 dlast_sga;		/* Last Destination address adjustment/scatter
151 				 * gather address
152 				 */
153 
154 	/* 0x1c */
155 	u32 biter_elink:1;	/* Enable channel-to-channel linking on major
156 				 * loop complete
157 				 */
158 	u32 biter_linkch:6;
159 	u32 biter:9;		/* Beginning "major" iteration count */
160 	u32 bwc:2;		/* Bandwidth control */
161 	u32 major_linkch:6;	/* Link channel number */
162 	u32 done:1;		/* Channel done */
163 	u32 active:1;		/* Channel active */
164 	u32 major_elink:1;	/* Enable channel-to-channel linking on major
165 				 * loop complete
166 				 */
167 	u32 e_sg:1;		/* Enable scatter/gather processing */
168 	u32 d_req:1;		/* Disable request */
169 	u32 int_half:1;		/* Enable an interrupt when major counter is
170 				 * half complete
171 				 */
172 	u32 int_maj:1;		/* Enable an interrupt when major iteration
173 				 * count completes
174 				 */
175 	u32 start:1;		/* Channel start */
176 };
177 
178 struct mpc_dma_desc {
179 	struct dma_async_tx_descriptor	desc;
180 	struct mpc_dma_tcd		*tcd;
181 	dma_addr_t			tcd_paddr;
182 	int				error;
183 	struct list_head		node;
184 };
185 
186 struct mpc_dma_chan {
187 	struct dma_chan			chan;
188 	struct list_head		free;
189 	struct list_head		prepared;
190 	struct list_head		queued;
191 	struct list_head		active;
192 	struct list_head		completed;
193 	struct mpc_dma_tcd		*tcd;
194 	dma_addr_t			tcd_paddr;
195 
196 	/* Lock for this structure */
197 	spinlock_t			lock;
198 };
199 
200 struct mpc_dma {
201 	struct dma_device		dma;
202 	struct tasklet_struct		tasklet;
203 	struct mpc_dma_chan		channels[MPC_DMA_CHANNELS];
204 	struct mpc_dma_regs __iomem	*regs;
205 	struct mpc_dma_tcd __iomem	*tcd;
206 	int				irq;
207 	int				irq2;
208 	uint				error_status;
209 	int				is_mpc8308;
210 
211 	/* Lock for error_status field in this structure */
212 	spinlock_t			error_status_lock;
213 };
214 
215 #define DRV_NAME	"mpc512x_dma"
216 
217 /* Convert struct dma_chan to struct mpc_dma_chan */
218 static inline struct mpc_dma_chan *dma_chan_to_mpc_dma_chan(struct dma_chan *c)
219 {
220 	return container_of(c, struct mpc_dma_chan, chan);
221 }
222 
223 /* Convert struct dma_chan to struct mpc_dma */
224 static inline struct mpc_dma *dma_chan_to_mpc_dma(struct dma_chan *c)
225 {
226 	struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(c);
227 	return container_of(mchan, struct mpc_dma, channels[c->chan_id]);
228 }
229 
230 /*
231  * Execute all queued DMA descriptors.
232  *
233  * Following requirements must be met while calling mpc_dma_execute():
234  * 	a) mchan->lock is acquired,
235  * 	b) mchan->active list is empty,
236  * 	c) mchan->queued list contains at least one entry.
237  */
238 static void mpc_dma_execute(struct mpc_dma_chan *mchan)
239 {
240 	struct mpc_dma *mdma = dma_chan_to_mpc_dma(&mchan->chan);
241 	struct mpc_dma_desc *first = NULL;
242 	struct mpc_dma_desc *prev = NULL;
243 	struct mpc_dma_desc *mdesc;
244 	int cid = mchan->chan.chan_id;
245 
246 	/* Move all queued descriptors to active list */
247 	list_splice_tail_init(&mchan->queued, &mchan->active);
248 
249 	/* Chain descriptors into one transaction */
250 	list_for_each_entry(mdesc, &mchan->active, node) {
251 		if (!first)
252 			first = mdesc;
253 
254 		if (!prev) {
255 			prev = mdesc;
256 			continue;
257 		}
258 
259 		prev->tcd->dlast_sga = mdesc->tcd_paddr;
260 		prev->tcd->e_sg = 1;
261 		mdesc->tcd->start = 1;
262 
263 		prev = mdesc;
264 	}
265 
266 	prev->tcd->int_maj = 1;
267 
268 	/* Send first descriptor in chain into hardware */
269 	memcpy_toio(&mdma->tcd[cid], first->tcd, sizeof(struct mpc_dma_tcd));
270 
271 	if (first != prev)
272 		mdma->tcd[cid].e_sg = 1;
273 	out_8(&mdma->regs->dmassrt, cid);
274 }
275 
276 /* Handle interrupt on one half of DMA controller (32 channels) */
277 static void mpc_dma_irq_process(struct mpc_dma *mdma, u32 is, u32 es, int off)
278 {
279 	struct mpc_dma_chan *mchan;
280 	struct mpc_dma_desc *mdesc;
281 	u32 status = is | es;
282 	int ch;
283 
284 	while ((ch = fls(status) - 1) >= 0) {
285 		status &= ~(1 << ch);
286 		mchan = &mdma->channels[ch + off];
287 
288 		spin_lock(&mchan->lock);
289 
290 		out_8(&mdma->regs->dmacint, ch + off);
291 		out_8(&mdma->regs->dmacerr, ch + off);
292 
293 		/* Check error status */
294 		if (es & (1 << ch))
295 			list_for_each_entry(mdesc, &mchan->active, node)
296 				mdesc->error = -EIO;
297 
298 		/* Execute queued descriptors */
299 		list_splice_tail_init(&mchan->active, &mchan->completed);
300 		if (!list_empty(&mchan->queued))
301 			mpc_dma_execute(mchan);
302 
303 		spin_unlock(&mchan->lock);
304 	}
305 }
306 
307 /* Interrupt handler */
308 static irqreturn_t mpc_dma_irq(int irq, void *data)
309 {
310 	struct mpc_dma *mdma = data;
311 	uint es;
312 
313 	/* Save error status register */
314 	es = in_be32(&mdma->regs->dmaes);
315 	spin_lock(&mdma->error_status_lock);
316 	if ((es & MPC_DMA_DMAES_VLD) && mdma->error_status == 0)
317 		mdma->error_status = es;
318 	spin_unlock(&mdma->error_status_lock);
319 
320 	/* Handle interrupt on each channel */
321 	if (mdma->dma.chancnt > 32) {
322 		mpc_dma_irq_process(mdma, in_be32(&mdma->regs->dmainth),
323 					in_be32(&mdma->regs->dmaerrh), 32);
324 	}
325 	mpc_dma_irq_process(mdma, in_be32(&mdma->regs->dmaintl),
326 					in_be32(&mdma->regs->dmaerrl), 0);
327 
328 	/* Schedule tasklet */
329 	tasklet_schedule(&mdma->tasklet);
330 
331 	return IRQ_HANDLED;
332 }
333 
334 /* process completed descriptors */
335 static void mpc_dma_process_completed(struct mpc_dma *mdma)
336 {
337 	dma_cookie_t last_cookie = 0;
338 	struct mpc_dma_chan *mchan;
339 	struct mpc_dma_desc *mdesc;
340 	struct dma_async_tx_descriptor *desc;
341 	unsigned long flags;
342 	LIST_HEAD(list);
343 	int i;
344 
345 	for (i = 0; i < mdma->dma.chancnt; i++) {
346 		mchan = &mdma->channels[i];
347 
348 		/* Get all completed descriptors */
349 		spin_lock_irqsave(&mchan->lock, flags);
350 		if (!list_empty(&mchan->completed))
351 			list_splice_tail_init(&mchan->completed, &list);
352 		spin_unlock_irqrestore(&mchan->lock, flags);
353 
354 		if (list_empty(&list))
355 			continue;
356 
357 		/* Execute callbacks and run dependencies */
358 		list_for_each_entry(mdesc, &list, node) {
359 			desc = &mdesc->desc;
360 
361 			if (desc->callback)
362 				desc->callback(desc->callback_param);
363 
364 			last_cookie = desc->cookie;
365 			dma_run_dependencies(desc);
366 		}
367 
368 		/* Free descriptors */
369 		spin_lock_irqsave(&mchan->lock, flags);
370 		list_splice_tail_init(&list, &mchan->free);
371 		mchan->chan.completed_cookie = last_cookie;
372 		spin_unlock_irqrestore(&mchan->lock, flags);
373 	}
374 }
375 
376 /* DMA Tasklet */
377 static void mpc_dma_tasklet(unsigned long data)
378 {
379 	struct mpc_dma *mdma = (void *)data;
380 	unsigned long flags;
381 	uint es;
382 
383 	spin_lock_irqsave(&mdma->error_status_lock, flags);
384 	es = mdma->error_status;
385 	mdma->error_status = 0;
386 	spin_unlock_irqrestore(&mdma->error_status_lock, flags);
387 
388 	/* Print nice error report */
389 	if (es) {
390 		dev_err(mdma->dma.dev,
391 			"Hardware reported following error(s) on channel %u:\n",
392 						      MPC_DMA_DMAES_ERRCHN(es));
393 
394 		if (es & MPC_DMA_DMAES_GPE)
395 			dev_err(mdma->dma.dev, "- Group Priority Error\n");
396 		if (es & MPC_DMA_DMAES_CPE)
397 			dev_err(mdma->dma.dev, "- Channel Priority Error\n");
398 		if (es & MPC_DMA_DMAES_SAE)
399 			dev_err(mdma->dma.dev, "- Source Address Error\n");
400 		if (es & MPC_DMA_DMAES_SOE)
401 			dev_err(mdma->dma.dev, "- Source Offset"
402 						" Configuration Error\n");
403 		if (es & MPC_DMA_DMAES_DAE)
404 			dev_err(mdma->dma.dev, "- Destination Address"
405 								" Error\n");
406 		if (es & MPC_DMA_DMAES_DOE)
407 			dev_err(mdma->dma.dev, "- Destination Offset"
408 						" Configuration Error\n");
409 		if (es & MPC_DMA_DMAES_NCE)
410 			dev_err(mdma->dma.dev, "- NBytes/Citter"
411 						" Configuration Error\n");
412 		if (es & MPC_DMA_DMAES_SGE)
413 			dev_err(mdma->dma.dev, "- Scatter/Gather"
414 						" Configuration Error\n");
415 		if (es & MPC_DMA_DMAES_SBE)
416 			dev_err(mdma->dma.dev, "- Source Bus Error\n");
417 		if (es & MPC_DMA_DMAES_DBE)
418 			dev_err(mdma->dma.dev, "- Destination Bus Error\n");
419 	}
420 
421 	mpc_dma_process_completed(mdma);
422 }
423 
424 /* Submit descriptor to hardware */
425 static dma_cookie_t mpc_dma_tx_submit(struct dma_async_tx_descriptor *txd)
426 {
427 	struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(txd->chan);
428 	struct mpc_dma_desc *mdesc;
429 	unsigned long flags;
430 	dma_cookie_t cookie;
431 
432 	mdesc = container_of(txd, struct mpc_dma_desc, desc);
433 
434 	spin_lock_irqsave(&mchan->lock, flags);
435 
436 	/* Move descriptor to queue */
437 	list_move_tail(&mdesc->node, &mchan->queued);
438 
439 	/* If channel is idle, execute all queued descriptors */
440 	if (list_empty(&mchan->active))
441 		mpc_dma_execute(mchan);
442 
443 	/* Update cookie */
444 	cookie = dma_cookie_assign(txd);
445 	spin_unlock_irqrestore(&mchan->lock, flags);
446 
447 	return cookie;
448 }
449 
450 /* Alloc channel resources */
451 static int mpc_dma_alloc_chan_resources(struct dma_chan *chan)
452 {
453 	struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan);
454 	struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
455 	struct mpc_dma_desc *mdesc;
456 	struct mpc_dma_tcd *tcd;
457 	dma_addr_t tcd_paddr;
458 	unsigned long flags;
459 	LIST_HEAD(descs);
460 	int i;
461 
462 	/* Alloc DMA memory for Transfer Control Descriptors */
463 	tcd = dma_alloc_coherent(mdma->dma.dev,
464 			MPC_DMA_DESCRIPTORS * sizeof(struct mpc_dma_tcd),
465 							&tcd_paddr, GFP_KERNEL);
466 	if (!tcd)
467 		return -ENOMEM;
468 
469 	/* Alloc descriptors for this channel */
470 	for (i = 0; i < MPC_DMA_DESCRIPTORS; i++) {
471 		mdesc = kzalloc(sizeof(struct mpc_dma_desc), GFP_KERNEL);
472 		if (!mdesc) {
473 			dev_notice(mdma->dma.dev, "Memory allocation error. "
474 					"Allocated only %u descriptors\n", i);
475 			break;
476 		}
477 
478 		dma_async_tx_descriptor_init(&mdesc->desc, chan);
479 		mdesc->desc.flags = DMA_CTRL_ACK;
480 		mdesc->desc.tx_submit = mpc_dma_tx_submit;
481 
482 		mdesc->tcd = &tcd[i];
483 		mdesc->tcd_paddr = tcd_paddr + (i * sizeof(struct mpc_dma_tcd));
484 
485 		list_add_tail(&mdesc->node, &descs);
486 	}
487 
488 	/* Return error only if no descriptors were allocated */
489 	if (i == 0) {
490 		dma_free_coherent(mdma->dma.dev,
491 			MPC_DMA_DESCRIPTORS * sizeof(struct mpc_dma_tcd),
492 								tcd, tcd_paddr);
493 		return -ENOMEM;
494 	}
495 
496 	spin_lock_irqsave(&mchan->lock, flags);
497 	mchan->tcd = tcd;
498 	mchan->tcd_paddr = tcd_paddr;
499 	list_splice_tail_init(&descs, &mchan->free);
500 	spin_unlock_irqrestore(&mchan->lock, flags);
501 
502 	/* Enable Error Interrupt */
503 	out_8(&mdma->regs->dmaseei, chan->chan_id);
504 
505 	return 0;
506 }
507 
508 /* Free channel resources */
509 static void mpc_dma_free_chan_resources(struct dma_chan *chan)
510 {
511 	struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan);
512 	struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
513 	struct mpc_dma_desc *mdesc, *tmp;
514 	struct mpc_dma_tcd *tcd;
515 	dma_addr_t tcd_paddr;
516 	unsigned long flags;
517 	LIST_HEAD(descs);
518 
519 	spin_lock_irqsave(&mchan->lock, flags);
520 
521 	/* Channel must be idle */
522 	BUG_ON(!list_empty(&mchan->prepared));
523 	BUG_ON(!list_empty(&mchan->queued));
524 	BUG_ON(!list_empty(&mchan->active));
525 	BUG_ON(!list_empty(&mchan->completed));
526 
527 	/* Move data */
528 	list_splice_tail_init(&mchan->free, &descs);
529 	tcd = mchan->tcd;
530 	tcd_paddr = mchan->tcd_paddr;
531 
532 	spin_unlock_irqrestore(&mchan->lock, flags);
533 
534 	/* Free DMA memory used by descriptors */
535 	dma_free_coherent(mdma->dma.dev,
536 			MPC_DMA_DESCRIPTORS * sizeof(struct mpc_dma_tcd),
537 								tcd, tcd_paddr);
538 
539 	/* Free descriptors */
540 	list_for_each_entry_safe(mdesc, tmp, &descs, node)
541 		kfree(mdesc);
542 
543 	/* Disable Error Interrupt */
544 	out_8(&mdma->regs->dmaceei, chan->chan_id);
545 }
546 
547 /* Send all pending descriptor to hardware */
548 static void mpc_dma_issue_pending(struct dma_chan *chan)
549 {
550 	/*
551 	 * We are posting descriptors to the hardware as soon as
552 	 * they are ready, so this function does nothing.
553 	 */
554 }
555 
556 /* Check request completion status */
557 static enum dma_status
558 mpc_dma_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
559 	       struct dma_tx_state *txstate)
560 {
561 	return dma_cookie_status(chan, cookie, txstate);
562 }
563 
564 /* Prepare descriptor for memory to memory copy */
565 static struct dma_async_tx_descriptor *
566 mpc_dma_prep_memcpy(struct dma_chan *chan, dma_addr_t dst, dma_addr_t src,
567 					size_t len, unsigned long flags)
568 {
569 	struct mpc_dma *mdma = dma_chan_to_mpc_dma(chan);
570 	struct mpc_dma_chan *mchan = dma_chan_to_mpc_dma_chan(chan);
571 	struct mpc_dma_desc *mdesc = NULL;
572 	struct mpc_dma_tcd *tcd;
573 	unsigned long iflags;
574 
575 	/* Get free descriptor */
576 	spin_lock_irqsave(&mchan->lock, iflags);
577 	if (!list_empty(&mchan->free)) {
578 		mdesc = list_first_entry(&mchan->free, struct mpc_dma_desc,
579 									node);
580 		list_del(&mdesc->node);
581 	}
582 	spin_unlock_irqrestore(&mchan->lock, iflags);
583 
584 	if (!mdesc) {
585 		/* try to free completed descriptors */
586 		mpc_dma_process_completed(mdma);
587 		return NULL;
588 	}
589 
590 	mdesc->error = 0;
591 	tcd = mdesc->tcd;
592 
593 	/* Prepare Transfer Control Descriptor for this transaction */
594 	memset(tcd, 0, sizeof(struct mpc_dma_tcd));
595 
596 	if (IS_ALIGNED(src | dst | len, 32)) {
597 		tcd->ssize = MPC_DMA_TSIZE_32;
598 		tcd->dsize = MPC_DMA_TSIZE_32;
599 		tcd->soff = 32;
600 		tcd->doff = 32;
601 	} else if (!mdma->is_mpc8308 && IS_ALIGNED(src | dst | len, 16)) {
602 		/* MPC8308 doesn't support 16 byte transfers */
603 		tcd->ssize = MPC_DMA_TSIZE_16;
604 		tcd->dsize = MPC_DMA_TSIZE_16;
605 		tcd->soff = 16;
606 		tcd->doff = 16;
607 	} else if (IS_ALIGNED(src | dst | len, 4)) {
608 		tcd->ssize = MPC_DMA_TSIZE_4;
609 		tcd->dsize = MPC_DMA_TSIZE_4;
610 		tcd->soff = 4;
611 		tcd->doff = 4;
612 	} else if (IS_ALIGNED(src | dst | len, 2)) {
613 		tcd->ssize = MPC_DMA_TSIZE_2;
614 		tcd->dsize = MPC_DMA_TSIZE_2;
615 		tcd->soff = 2;
616 		tcd->doff = 2;
617 	} else {
618 		tcd->ssize = MPC_DMA_TSIZE_1;
619 		tcd->dsize = MPC_DMA_TSIZE_1;
620 		tcd->soff = 1;
621 		tcd->doff = 1;
622 	}
623 
624 	tcd->saddr = src;
625 	tcd->daddr = dst;
626 	tcd->nbytes = len;
627 	tcd->biter = 1;
628 	tcd->citer = 1;
629 
630 	/* Place descriptor in prepared list */
631 	spin_lock_irqsave(&mchan->lock, iflags);
632 	list_add_tail(&mdesc->node, &mchan->prepared);
633 	spin_unlock_irqrestore(&mchan->lock, iflags);
634 
635 	return &mdesc->desc;
636 }
637 
638 static int mpc_dma_probe(struct platform_device *op)
639 {
640 	struct device_node *dn = op->dev.of_node;
641 	struct device *dev = &op->dev;
642 	struct dma_device *dma;
643 	struct mpc_dma *mdma;
644 	struct mpc_dma_chan *mchan;
645 	struct resource res;
646 	ulong regs_start, regs_size;
647 	int retval, i;
648 
649 	mdma = devm_kzalloc(dev, sizeof(struct mpc_dma), GFP_KERNEL);
650 	if (!mdma) {
651 		dev_err(dev, "Memory exhausted!\n");
652 		return -ENOMEM;
653 	}
654 
655 	mdma->irq = irq_of_parse_and_map(dn, 0);
656 	if (mdma->irq == NO_IRQ) {
657 		dev_err(dev, "Error mapping IRQ!\n");
658 		return -EINVAL;
659 	}
660 
661 	if (of_device_is_compatible(dn, "fsl,mpc8308-dma")) {
662 		mdma->is_mpc8308 = 1;
663 		mdma->irq2 = irq_of_parse_and_map(dn, 1);
664 		if (mdma->irq2 == NO_IRQ) {
665 			dev_err(dev, "Error mapping IRQ!\n");
666 			return -EINVAL;
667 		}
668 	}
669 
670 	retval = of_address_to_resource(dn, 0, &res);
671 	if (retval) {
672 		dev_err(dev, "Error parsing memory region!\n");
673 		return retval;
674 	}
675 
676 	regs_start = res.start;
677 	regs_size = resource_size(&res);
678 
679 	if (!devm_request_mem_region(dev, regs_start, regs_size, DRV_NAME)) {
680 		dev_err(dev, "Error requesting memory region!\n");
681 		return -EBUSY;
682 	}
683 
684 	mdma->regs = devm_ioremap(dev, regs_start, regs_size);
685 	if (!mdma->regs) {
686 		dev_err(dev, "Error mapping memory region!\n");
687 		return -ENOMEM;
688 	}
689 
690 	mdma->tcd = (struct mpc_dma_tcd *)((u8 *)(mdma->regs)
691 							+ MPC_DMA_TCD_OFFSET);
692 
693 	retval = devm_request_irq(dev, mdma->irq, &mpc_dma_irq, 0, DRV_NAME,
694 									mdma);
695 	if (retval) {
696 		dev_err(dev, "Error requesting IRQ!\n");
697 		return -EINVAL;
698 	}
699 
700 	if (mdma->is_mpc8308) {
701 		retval = devm_request_irq(dev, mdma->irq2, &mpc_dma_irq, 0,
702 				DRV_NAME, mdma);
703 		if (retval) {
704 			dev_err(dev, "Error requesting IRQ2!\n");
705 			return -EINVAL;
706 		}
707 	}
708 
709 	spin_lock_init(&mdma->error_status_lock);
710 
711 	dma = &mdma->dma;
712 	dma->dev = dev;
713 	if (!mdma->is_mpc8308)
714 		dma->chancnt = MPC_DMA_CHANNELS;
715 	else
716 		dma->chancnt = 16; /* MPC8308 DMA has only 16 channels */
717 	dma->device_alloc_chan_resources = mpc_dma_alloc_chan_resources;
718 	dma->device_free_chan_resources = mpc_dma_free_chan_resources;
719 	dma->device_issue_pending = mpc_dma_issue_pending;
720 	dma->device_tx_status = mpc_dma_tx_status;
721 	dma->device_prep_dma_memcpy = mpc_dma_prep_memcpy;
722 
723 	INIT_LIST_HEAD(&dma->channels);
724 	dma_cap_set(DMA_MEMCPY, dma->cap_mask);
725 
726 	for (i = 0; i < dma->chancnt; i++) {
727 		mchan = &mdma->channels[i];
728 
729 		mchan->chan.device = dma;
730 		dma_cookie_init(&mchan->chan);
731 
732 		INIT_LIST_HEAD(&mchan->free);
733 		INIT_LIST_HEAD(&mchan->prepared);
734 		INIT_LIST_HEAD(&mchan->queued);
735 		INIT_LIST_HEAD(&mchan->active);
736 		INIT_LIST_HEAD(&mchan->completed);
737 
738 		spin_lock_init(&mchan->lock);
739 		list_add_tail(&mchan->chan.device_node, &dma->channels);
740 	}
741 
742 	tasklet_init(&mdma->tasklet, mpc_dma_tasklet, (unsigned long)mdma);
743 
744 	/*
745 	 * Configure DMA Engine:
746 	 * - Dynamic clock,
747 	 * - Round-robin group arbitration,
748 	 * - Round-robin channel arbitration.
749 	 */
750 	if (!mdma->is_mpc8308) {
751 		out_be32(&mdma->regs->dmacr, MPC_DMA_DMACR_EDCG |
752 					MPC_DMA_DMACR_ERGA | MPC_DMA_DMACR_ERCA);
753 
754 		/* Disable hardware DMA requests */
755 		out_be32(&mdma->regs->dmaerqh, 0);
756 		out_be32(&mdma->regs->dmaerql, 0);
757 
758 		/* Disable error interrupts */
759 		out_be32(&mdma->regs->dmaeeih, 0);
760 		out_be32(&mdma->regs->dmaeeil, 0);
761 
762 		/* Clear interrupts status */
763 		out_be32(&mdma->regs->dmainth, 0xFFFFFFFF);
764 		out_be32(&mdma->regs->dmaintl, 0xFFFFFFFF);
765 		out_be32(&mdma->regs->dmaerrh, 0xFFFFFFFF);
766 		out_be32(&mdma->regs->dmaerrl, 0xFFFFFFFF);
767 
768 		/* Route interrupts to IPIC */
769 		out_be32(&mdma->regs->dmaihsa, 0);
770 		out_be32(&mdma->regs->dmailsa, 0);
771 	} else {
772 		/* MPC8308 has 16 channels and lacks some registers */
773 		out_be32(&mdma->regs->dmacr, MPC_DMA_DMACR_ERCA);
774 
775 		/* enable snooping */
776 		out_be32(&mdma->regs->dmagpor, MPC_DMA_DMAGPOR_SNOOP_ENABLE);
777 		/* Disable error interrupts */
778 		out_be32(&mdma->regs->dmaeeil, 0);
779 
780 		/* Clear interrupts status */
781 		out_be32(&mdma->regs->dmaintl, 0xFFFF);
782 		out_be32(&mdma->regs->dmaerrl, 0xFFFF);
783 	}
784 
785 	/* Register DMA engine */
786 	dev_set_drvdata(dev, mdma);
787 	retval = dma_async_device_register(dma);
788 	if (retval) {
789 		devm_free_irq(dev, mdma->irq, mdma);
790 		irq_dispose_mapping(mdma->irq);
791 	}
792 
793 	return retval;
794 }
795 
796 static int mpc_dma_remove(struct platform_device *op)
797 {
798 	struct device *dev = &op->dev;
799 	struct mpc_dma *mdma = dev_get_drvdata(dev);
800 
801 	dma_async_device_unregister(&mdma->dma);
802 	devm_free_irq(dev, mdma->irq, mdma);
803 	irq_dispose_mapping(mdma->irq);
804 
805 	return 0;
806 }
807 
808 static struct of_device_id mpc_dma_match[] = {
809 	{ .compatible = "fsl,mpc5121-dma", },
810 	{},
811 };
812 
813 static struct platform_driver mpc_dma_driver = {
814 	.probe		= mpc_dma_probe,
815 	.remove		= mpc_dma_remove,
816 	.driver = {
817 		.name = DRV_NAME,
818 		.owner = THIS_MODULE,
819 		.of_match_table	= mpc_dma_match,
820 	},
821 };
822 
823 module_platform_driver(mpc_dma_driver);
824 
825 MODULE_LICENSE("GPL");
826 MODULE_AUTHOR("Piotr Ziecik <kosmo@semihalf.com>");
827