xref: /openbmc/linux/drivers/dma/pxa_dma.c (revision 78700c0a)
1 /*
2  * Copyright 2015 Robert Jarzmik <robert.jarzmik@free.fr>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8 
9 #include <linux/err.h>
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/types.h>
13 #include <linux/interrupt.h>
14 #include <linux/dma-mapping.h>
15 #include <linux/slab.h>
16 #include <linux/dmaengine.h>
17 #include <linux/platform_device.h>
18 #include <linux/device.h>
19 #include <linux/platform_data/mmp_dma.h>
20 #include <linux/dmapool.h>
21 #include <linux/of_device.h>
22 #include <linux/of_dma.h>
23 #include <linux/of.h>
24 #include <linux/dma/pxa-dma.h>
25 
26 #include "dmaengine.h"
27 #include "virt-dma.h"
28 
29 #define DCSR(n)		(0x0000 + ((n) << 2))
30 #define DALGN(n)	0x00a0
31 #define DINT		0x00f0
32 #define DDADR(n)	(0x0200 + ((n) << 4))
33 #define DSADR(n)	(0x0204 + ((n) << 4))
34 #define DTADR(n)	(0x0208 + ((n) << 4))
35 #define DCMD(n)		(0x020c + ((n) << 4))
36 
37 #define PXA_DCSR_RUN		BIT(31)	/* Run Bit (read / write) */
38 #define PXA_DCSR_NODESC		BIT(30)	/* No-Descriptor Fetch (read / write) */
39 #define PXA_DCSR_STOPIRQEN	BIT(29)	/* Stop Interrupt Enable (R/W) */
40 #define PXA_DCSR_REQPEND	BIT(8)	/* Request Pending (read-only) */
41 #define PXA_DCSR_STOPSTATE	BIT(3)	/* Stop State (read-only) */
42 #define PXA_DCSR_ENDINTR	BIT(2)	/* End Interrupt (read / write) */
43 #define PXA_DCSR_STARTINTR	BIT(1)	/* Start Interrupt (read / write) */
44 #define PXA_DCSR_BUSERR		BIT(0)	/* Bus Error Interrupt (read / write) */
45 
46 #define PXA_DCSR_EORIRQEN	BIT(28)	/* End of Receive IRQ Enable (R/W) */
47 #define PXA_DCSR_EORJMPEN	BIT(27)	/* Jump to next descriptor on EOR */
48 #define PXA_DCSR_EORSTOPEN	BIT(26)	/* STOP on an EOR */
49 #define PXA_DCSR_SETCMPST	BIT(25)	/* Set Descriptor Compare Status */
50 #define PXA_DCSR_CLRCMPST	BIT(24)	/* Clear Descriptor Compare Status */
51 #define PXA_DCSR_CMPST		BIT(10)	/* The Descriptor Compare Status */
52 #define PXA_DCSR_EORINTR	BIT(9)	/* The end of Receive */
53 
54 #define DRCMR_MAPVLD	BIT(7)	/* Map Valid (read / write) */
55 #define DRCMR_CHLNUM	0x1f	/* mask for Channel Number (read / write) */
56 
57 #define DDADR_DESCADDR	0xfffffff0	/* Address of next descriptor (mask) */
58 #define DDADR_STOP	BIT(0)	/* Stop (read / write) */
59 
60 #define PXA_DCMD_INCSRCADDR	BIT(31)	/* Source Address Increment Setting. */
61 #define PXA_DCMD_INCTRGADDR	BIT(30)	/* Target Address Increment Setting. */
62 #define PXA_DCMD_FLOWSRC	BIT(29)	/* Flow Control by the source. */
63 #define PXA_DCMD_FLOWTRG	BIT(28)	/* Flow Control by the target. */
64 #define PXA_DCMD_STARTIRQEN	BIT(22)	/* Start Interrupt Enable */
65 #define PXA_DCMD_ENDIRQEN	BIT(21)	/* End Interrupt Enable */
66 #define PXA_DCMD_ENDIAN		BIT(18)	/* Device Endian-ness. */
67 #define PXA_DCMD_BURST8		(1 << 16)	/* 8 byte burst */
68 #define PXA_DCMD_BURST16	(2 << 16)	/* 16 byte burst */
69 #define PXA_DCMD_BURST32	(3 << 16)	/* 32 byte burst */
70 #define PXA_DCMD_WIDTH1		(1 << 14)	/* 1 byte width */
71 #define PXA_DCMD_WIDTH2		(2 << 14)	/* 2 byte width (HalfWord) */
72 #define PXA_DCMD_WIDTH4		(3 << 14)	/* 4 byte width (Word) */
73 #define PXA_DCMD_LENGTH		0x01fff		/* length mask (max = 8K - 1) */
74 
75 #define PDMA_ALIGNMENT		3
76 #define PDMA_MAX_DESC_BYTES	(PXA_DCMD_LENGTH & ~((1 << PDMA_ALIGNMENT) - 1))
77 
78 struct pxad_desc_hw {
79 	u32 ddadr;	/* Points to the next descriptor + flags */
80 	u32 dsadr;	/* DSADR value for the current transfer */
81 	u32 dtadr;	/* DTADR value for the current transfer */
82 	u32 dcmd;	/* DCMD value for the current transfer */
83 } __aligned(16);
84 
85 struct pxad_desc_sw {
86 	struct virt_dma_desc	vd;		/* Virtual descriptor */
87 	int			nb_desc;	/* Number of hw. descriptors */
88 	size_t			len;		/* Number of bytes xfered */
89 	dma_addr_t		first;		/* First descriptor's addr */
90 
91 	/* At least one descriptor has an src/dst address not multiple of 8 */
92 	bool			misaligned;
93 	bool			cyclic;
94 	struct dma_pool		*desc_pool;	/* Channel's used allocator */
95 
96 	struct pxad_desc_hw	*hw_desc[];	/* DMA coherent descriptors */
97 };
98 
99 struct pxad_phy {
100 	int			idx;
101 	void __iomem		*base;
102 	struct pxad_chan	*vchan;
103 };
104 
105 struct pxad_chan {
106 	struct virt_dma_chan	vc;		/* Virtual channel */
107 	u32			drcmr;		/* Requestor of the channel */
108 	enum pxad_chan_prio	prio;		/* Required priority of phy */
109 	/*
110 	 * At least one desc_sw in submitted or issued transfers on this channel
111 	 * has one address such as: addr % 8 != 0. This implies the DALGN
112 	 * setting on the phy.
113 	 */
114 	bool			misaligned;
115 	struct dma_slave_config	cfg;		/* Runtime config */
116 
117 	/* protected by vc->lock */
118 	struct pxad_phy		*phy;
119 	struct dma_pool		*desc_pool;	/* Descriptors pool */
120 	dma_cookie_t		bus_error;
121 };
122 
123 struct pxad_device {
124 	struct dma_device		slave;
125 	int				nr_chans;
126 	int				nr_requestors;
127 	void __iomem			*base;
128 	struct pxad_phy			*phys;
129 	spinlock_t			phy_lock;	/* Phy association */
130 #ifdef CONFIG_DEBUG_FS
131 	struct dentry			*dbgfs_root;
132 	struct dentry			*dbgfs_state;
133 	struct dentry			**dbgfs_chan;
134 #endif
135 };
136 
137 #define tx_to_pxad_desc(tx)					\
138 	container_of(tx, struct pxad_desc_sw, async_tx)
139 #define to_pxad_chan(dchan)					\
140 	container_of(dchan, struct pxad_chan, vc.chan)
141 #define to_pxad_dev(dmadev)					\
142 	container_of(dmadev, struct pxad_device, slave)
143 #define to_pxad_sw_desc(_vd)				\
144 	container_of((_vd), struct pxad_desc_sw, vd)
145 
146 #define _phy_readl_relaxed(phy, _reg)					\
147 	readl_relaxed((phy)->base + _reg((phy)->idx))
148 #define phy_readl_relaxed(phy, _reg)					\
149 	({								\
150 		u32 _v;							\
151 		_v = readl_relaxed((phy)->base + _reg((phy)->idx));	\
152 		dev_vdbg(&phy->vchan->vc.chan.dev->device,		\
153 			 "%s(): readl(%s): 0x%08x\n", __func__, #_reg,	\
154 			  _v);						\
155 		_v;							\
156 	})
157 #define phy_writel(phy, val, _reg)					\
158 	do {								\
159 		writel((val), (phy)->base + _reg((phy)->idx));		\
160 		dev_vdbg(&phy->vchan->vc.chan.dev->device,		\
161 			 "%s(): writel(0x%08x, %s)\n",			\
162 			 __func__, (u32)(val), #_reg);			\
163 	} while (0)
164 #define phy_writel_relaxed(phy, val, _reg)				\
165 	do {								\
166 		writel_relaxed((val), (phy)->base + _reg((phy)->idx));	\
167 		dev_vdbg(&phy->vchan->vc.chan.dev->device,		\
168 			 "%s(): writel_relaxed(0x%08x, %s)\n",		\
169 			 __func__, (u32)(val), #_reg);			\
170 	} while (0)
171 
172 static unsigned int pxad_drcmr(unsigned int line)
173 {
174 	if (line < 64)
175 		return 0x100 + line * 4;
176 	return 0x1000 + line * 4;
177 }
178 
179 /*
180  * Debug fs
181  */
182 #ifdef CONFIG_DEBUG_FS
183 #include <linux/debugfs.h>
184 #include <linux/uaccess.h>
185 #include <linux/seq_file.h>
186 
187 static int dbg_show_requester_chan(struct seq_file *s, void *p)
188 {
189 	struct pxad_phy *phy = s->private;
190 	int i;
191 	u32 drcmr;
192 
193 	seq_printf(s, "DMA channel %d requester :\n", phy->idx);
194 	for (i = 0; i < 70; i++) {
195 		drcmr = readl_relaxed(phy->base + pxad_drcmr(i));
196 		if ((drcmr & DRCMR_CHLNUM) == phy->idx)
197 			seq_printf(s, "\tRequester %d (MAPVLD=%d)\n", i,
198 				   !!(drcmr & DRCMR_MAPVLD));
199 	}
200 	return 0;
201 }
202 
203 static inline int dbg_burst_from_dcmd(u32 dcmd)
204 {
205 	int burst = (dcmd >> 16) & 0x3;
206 
207 	return burst ? 4 << burst : 0;
208 }
209 
210 static int is_phys_valid(unsigned long addr)
211 {
212 	return pfn_valid(__phys_to_pfn(addr));
213 }
214 
215 #define PXA_DCSR_STR(flag) (dcsr & PXA_DCSR_##flag ? #flag" " : "")
216 #define PXA_DCMD_STR(flag) (dcmd & PXA_DCMD_##flag ? #flag" " : "")
217 
218 static int dbg_show_descriptors(struct seq_file *s, void *p)
219 {
220 	struct pxad_phy *phy = s->private;
221 	int i, max_show = 20, burst, width;
222 	u32 dcmd;
223 	unsigned long phys_desc, ddadr;
224 	struct pxad_desc_hw *desc;
225 
226 	phys_desc = ddadr = _phy_readl_relaxed(phy, DDADR);
227 
228 	seq_printf(s, "DMA channel %d descriptors :\n", phy->idx);
229 	seq_printf(s, "[%03d] First descriptor unknown\n", 0);
230 	for (i = 1; i < max_show && is_phys_valid(phys_desc); i++) {
231 		desc = phys_to_virt(phys_desc);
232 		dcmd = desc->dcmd;
233 		burst = dbg_burst_from_dcmd(dcmd);
234 		width = (1 << ((dcmd >> 14) & 0x3)) >> 1;
235 
236 		seq_printf(s, "[%03d] Desc at %08lx(virt %p)\n",
237 			   i, phys_desc, desc);
238 		seq_printf(s, "\tDDADR = %08x\n", desc->ddadr);
239 		seq_printf(s, "\tDSADR = %08x\n", desc->dsadr);
240 		seq_printf(s, "\tDTADR = %08x\n", desc->dtadr);
241 		seq_printf(s, "\tDCMD  = %08x (%s%s%s%s%s%s%sburst=%d width=%d len=%d)\n",
242 			   dcmd,
243 			   PXA_DCMD_STR(INCSRCADDR), PXA_DCMD_STR(INCTRGADDR),
244 			   PXA_DCMD_STR(FLOWSRC), PXA_DCMD_STR(FLOWTRG),
245 			   PXA_DCMD_STR(STARTIRQEN), PXA_DCMD_STR(ENDIRQEN),
246 			   PXA_DCMD_STR(ENDIAN), burst, width,
247 			   dcmd & PXA_DCMD_LENGTH);
248 		phys_desc = desc->ddadr;
249 	}
250 	if (i == max_show)
251 		seq_printf(s, "[%03d] Desc at %08lx ... max display reached\n",
252 			   i, phys_desc);
253 	else
254 		seq_printf(s, "[%03d] Desc at %08lx is %s\n",
255 			   i, phys_desc, phys_desc == DDADR_STOP ?
256 			   "DDADR_STOP" : "invalid");
257 
258 	return 0;
259 }
260 
261 static int dbg_show_chan_state(struct seq_file *s, void *p)
262 {
263 	struct pxad_phy *phy = s->private;
264 	u32 dcsr, dcmd;
265 	int burst, width;
266 	static const char * const str_prio[] = {
267 		"high", "normal", "low", "invalid"
268 	};
269 
270 	dcsr = _phy_readl_relaxed(phy, DCSR);
271 	dcmd = _phy_readl_relaxed(phy, DCMD);
272 	burst = dbg_burst_from_dcmd(dcmd);
273 	width = (1 << ((dcmd >> 14) & 0x3)) >> 1;
274 
275 	seq_printf(s, "DMA channel %d\n", phy->idx);
276 	seq_printf(s, "\tPriority : %s\n",
277 			  str_prio[(phy->idx & 0xf) / 4]);
278 	seq_printf(s, "\tUnaligned transfer bit: %s\n",
279 			  _phy_readl_relaxed(phy, DALGN) & BIT(phy->idx) ?
280 			  "yes" : "no");
281 	seq_printf(s, "\tDCSR  = %08x (%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s)\n",
282 		   dcsr, PXA_DCSR_STR(RUN), PXA_DCSR_STR(NODESC),
283 		   PXA_DCSR_STR(STOPIRQEN), PXA_DCSR_STR(EORIRQEN),
284 		   PXA_DCSR_STR(EORJMPEN), PXA_DCSR_STR(EORSTOPEN),
285 		   PXA_DCSR_STR(SETCMPST), PXA_DCSR_STR(CLRCMPST),
286 		   PXA_DCSR_STR(CMPST), PXA_DCSR_STR(EORINTR),
287 		   PXA_DCSR_STR(REQPEND), PXA_DCSR_STR(STOPSTATE),
288 		   PXA_DCSR_STR(ENDINTR), PXA_DCSR_STR(STARTINTR),
289 		   PXA_DCSR_STR(BUSERR));
290 
291 	seq_printf(s, "\tDCMD  = %08x (%s%s%s%s%s%s%sburst=%d width=%d len=%d)\n",
292 		   dcmd,
293 		   PXA_DCMD_STR(INCSRCADDR), PXA_DCMD_STR(INCTRGADDR),
294 		   PXA_DCMD_STR(FLOWSRC), PXA_DCMD_STR(FLOWTRG),
295 		   PXA_DCMD_STR(STARTIRQEN), PXA_DCMD_STR(ENDIRQEN),
296 		   PXA_DCMD_STR(ENDIAN), burst, width, dcmd & PXA_DCMD_LENGTH);
297 	seq_printf(s, "\tDSADR = %08x\n", _phy_readl_relaxed(phy, DSADR));
298 	seq_printf(s, "\tDTADR = %08x\n", _phy_readl_relaxed(phy, DTADR));
299 	seq_printf(s, "\tDDADR = %08x\n", _phy_readl_relaxed(phy, DDADR));
300 
301 	return 0;
302 }
303 
304 static int dbg_show_state(struct seq_file *s, void *p)
305 {
306 	struct pxad_device *pdev = s->private;
307 
308 	/* basic device status */
309 	seq_puts(s, "DMA engine status\n");
310 	seq_printf(s, "\tChannel number: %d\n", pdev->nr_chans);
311 
312 	return 0;
313 }
314 
315 #define DBGFS_FUNC_DECL(name) \
316 static int dbg_open_##name(struct inode *inode, struct file *file) \
317 { \
318 	return single_open(file, dbg_show_##name, inode->i_private); \
319 } \
320 static const struct file_operations dbg_fops_##name = { \
321 	.owner		= THIS_MODULE, \
322 	.open		= dbg_open_##name, \
323 	.llseek		= seq_lseek, \
324 	.read		= seq_read, \
325 	.release	= single_release, \
326 }
327 
328 DBGFS_FUNC_DECL(state);
329 DBGFS_FUNC_DECL(chan_state);
330 DBGFS_FUNC_DECL(descriptors);
331 DBGFS_FUNC_DECL(requester_chan);
332 
333 static struct dentry *pxad_dbg_alloc_chan(struct pxad_device *pdev,
334 					     int ch, struct dentry *chandir)
335 {
336 	char chan_name[11];
337 	struct dentry *chan, *chan_state = NULL, *chan_descr = NULL;
338 	struct dentry *chan_reqs = NULL;
339 	void *dt;
340 
341 	scnprintf(chan_name, sizeof(chan_name), "%d", ch);
342 	chan = debugfs_create_dir(chan_name, chandir);
343 	dt = (void *)&pdev->phys[ch];
344 
345 	if (chan)
346 		chan_state = debugfs_create_file("state", 0400, chan, dt,
347 						 &dbg_fops_chan_state);
348 	if (chan_state)
349 		chan_descr = debugfs_create_file("descriptors", 0400, chan, dt,
350 						 &dbg_fops_descriptors);
351 	if (chan_descr)
352 		chan_reqs = debugfs_create_file("requesters", 0400, chan, dt,
353 						&dbg_fops_requester_chan);
354 	if (!chan_reqs)
355 		goto err_state;
356 
357 	return chan;
358 
359 err_state:
360 	debugfs_remove_recursive(chan);
361 	return NULL;
362 }
363 
364 static void pxad_init_debugfs(struct pxad_device *pdev)
365 {
366 	int i;
367 	struct dentry *chandir;
368 
369 	pdev->dbgfs_root = debugfs_create_dir(dev_name(pdev->slave.dev), NULL);
370 	if (IS_ERR(pdev->dbgfs_root) || !pdev->dbgfs_root)
371 		goto err_root;
372 
373 	pdev->dbgfs_state = debugfs_create_file("state", 0400, pdev->dbgfs_root,
374 						pdev, &dbg_fops_state);
375 	if (!pdev->dbgfs_state)
376 		goto err_state;
377 
378 	pdev->dbgfs_chan =
379 		kmalloc_array(pdev->nr_chans, sizeof(*pdev->dbgfs_state),
380 			      GFP_KERNEL);
381 	if (!pdev->dbgfs_chan)
382 		goto err_alloc;
383 
384 	chandir = debugfs_create_dir("channels", pdev->dbgfs_root);
385 	if (!chandir)
386 		goto err_chandir;
387 
388 	for (i = 0; i < pdev->nr_chans; i++) {
389 		pdev->dbgfs_chan[i] = pxad_dbg_alloc_chan(pdev, i, chandir);
390 		if (!pdev->dbgfs_chan[i])
391 			goto err_chans;
392 	}
393 
394 	return;
395 err_chans:
396 err_chandir:
397 	kfree(pdev->dbgfs_chan);
398 err_alloc:
399 err_state:
400 	debugfs_remove_recursive(pdev->dbgfs_root);
401 err_root:
402 	pr_err("pxad: debugfs is not available\n");
403 }
404 
405 static void pxad_cleanup_debugfs(struct pxad_device *pdev)
406 {
407 	debugfs_remove_recursive(pdev->dbgfs_root);
408 }
409 #else
410 static inline void pxad_init_debugfs(struct pxad_device *pdev) {}
411 static inline void pxad_cleanup_debugfs(struct pxad_device *pdev) {}
412 #endif
413 
414 /*
415  * In the transition phase where legacy pxa handling is done at the same time as
416  * mmp_dma, the DMA physical channel split between the 2 DMA providers is done
417  * through legacy_reserved. Legacy code reserves DMA channels by settings
418  * corresponding bits in legacy_reserved.
419  */
420 static u32 legacy_reserved;
421 static u32 legacy_unavailable;
422 
423 static struct pxad_phy *lookup_phy(struct pxad_chan *pchan)
424 {
425 	int prio, i;
426 	struct pxad_device *pdev = to_pxad_dev(pchan->vc.chan.device);
427 	struct pxad_phy *phy, *found = NULL;
428 	unsigned long flags;
429 
430 	/*
431 	 * dma channel priorities
432 	 * ch 0 - 3,  16 - 19  <--> (0)
433 	 * ch 4 - 7,  20 - 23  <--> (1)
434 	 * ch 8 - 11, 24 - 27  <--> (2)
435 	 * ch 12 - 15, 28 - 31  <--> (3)
436 	 */
437 
438 	spin_lock_irqsave(&pdev->phy_lock, flags);
439 	for (prio = pchan->prio; prio >= PXAD_PRIO_HIGHEST; prio--) {
440 		for (i = 0; i < pdev->nr_chans; i++) {
441 			if (prio != (i & 0xf) >> 2)
442 				continue;
443 			if ((i < 32) && (legacy_reserved & BIT(i)))
444 				continue;
445 			phy = &pdev->phys[i];
446 			if (!phy->vchan) {
447 				phy->vchan = pchan;
448 				found = phy;
449 				if (i < 32)
450 					legacy_unavailable |= BIT(i);
451 				goto out_unlock;
452 			}
453 		}
454 	}
455 
456 out_unlock:
457 	spin_unlock_irqrestore(&pdev->phy_lock, flags);
458 	dev_dbg(&pchan->vc.chan.dev->device,
459 		"%s(): phy=%p(%d)\n", __func__, found,
460 		found ? found->idx : -1);
461 
462 	return found;
463 }
464 
465 static void pxad_free_phy(struct pxad_chan *chan)
466 {
467 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
468 	unsigned long flags;
469 	u32 reg;
470 	int i;
471 
472 	dev_dbg(&chan->vc.chan.dev->device,
473 		"%s(): freeing\n", __func__);
474 	if (!chan->phy)
475 		return;
476 
477 	/* clear the channel mapping in DRCMR */
478 	if (chan->drcmr <= pdev->nr_requestors) {
479 		reg = pxad_drcmr(chan->drcmr);
480 		writel_relaxed(0, chan->phy->base + reg);
481 	}
482 
483 	spin_lock_irqsave(&pdev->phy_lock, flags);
484 	for (i = 0; i < 32; i++)
485 		if (chan->phy == &pdev->phys[i])
486 			legacy_unavailable &= ~BIT(i);
487 	chan->phy->vchan = NULL;
488 	chan->phy = NULL;
489 	spin_unlock_irqrestore(&pdev->phy_lock, flags);
490 }
491 
492 static bool is_chan_running(struct pxad_chan *chan)
493 {
494 	u32 dcsr;
495 	struct pxad_phy *phy = chan->phy;
496 
497 	if (!phy)
498 		return false;
499 	dcsr = phy_readl_relaxed(phy, DCSR);
500 	return dcsr & PXA_DCSR_RUN;
501 }
502 
503 static bool is_running_chan_misaligned(struct pxad_chan *chan)
504 {
505 	u32 dalgn;
506 
507 	BUG_ON(!chan->phy);
508 	dalgn = phy_readl_relaxed(chan->phy, DALGN);
509 	return dalgn & (BIT(chan->phy->idx));
510 }
511 
512 static void phy_enable(struct pxad_phy *phy, bool misaligned)
513 {
514 	struct pxad_device *pdev;
515 	u32 reg, dalgn;
516 
517 	if (!phy->vchan)
518 		return;
519 
520 	dev_dbg(&phy->vchan->vc.chan.dev->device,
521 		"%s(); phy=%p(%d) misaligned=%d\n", __func__,
522 		phy, phy->idx, misaligned);
523 
524 	pdev = to_pxad_dev(phy->vchan->vc.chan.device);
525 	if (phy->vchan->drcmr <= pdev->nr_requestors) {
526 		reg = pxad_drcmr(phy->vchan->drcmr);
527 		writel_relaxed(DRCMR_MAPVLD | phy->idx, phy->base + reg);
528 	}
529 
530 	dalgn = phy_readl_relaxed(phy, DALGN);
531 	if (misaligned)
532 		dalgn |= BIT(phy->idx);
533 	else
534 		dalgn &= ~BIT(phy->idx);
535 	phy_writel_relaxed(phy, dalgn, DALGN);
536 
537 	phy_writel(phy, PXA_DCSR_STOPIRQEN | PXA_DCSR_ENDINTR |
538 		   PXA_DCSR_BUSERR | PXA_DCSR_RUN, DCSR);
539 }
540 
541 static void phy_disable(struct pxad_phy *phy)
542 {
543 	u32 dcsr;
544 
545 	if (!phy)
546 		return;
547 
548 	dcsr = phy_readl_relaxed(phy, DCSR);
549 	dev_dbg(&phy->vchan->vc.chan.dev->device,
550 		"%s(): phy=%p(%d)\n", __func__, phy, phy->idx);
551 	phy_writel(phy, dcsr & ~PXA_DCSR_RUN & ~PXA_DCSR_STOPIRQEN, DCSR);
552 }
553 
554 static void pxad_launch_chan(struct pxad_chan *chan,
555 				 struct pxad_desc_sw *desc)
556 {
557 	dev_dbg(&chan->vc.chan.dev->device,
558 		"%s(): desc=%p\n", __func__, desc);
559 	if (!chan->phy) {
560 		chan->phy = lookup_phy(chan);
561 		if (!chan->phy) {
562 			dev_dbg(&chan->vc.chan.dev->device,
563 				"%s(): no free dma channel\n", __func__);
564 			return;
565 		}
566 	}
567 	chan->bus_error = 0;
568 
569 	/*
570 	 * Program the descriptor's address into the DMA controller,
571 	 * then start the DMA transaction
572 	 */
573 	phy_writel(chan->phy, desc->first, DDADR);
574 	phy_enable(chan->phy, chan->misaligned);
575 }
576 
577 static void set_updater_desc(struct pxad_desc_sw *sw_desc,
578 			     unsigned long flags)
579 {
580 	struct pxad_desc_hw *updater =
581 		sw_desc->hw_desc[sw_desc->nb_desc - 1];
582 	dma_addr_t dma = sw_desc->hw_desc[sw_desc->nb_desc - 2]->ddadr;
583 
584 	updater->ddadr = DDADR_STOP;
585 	updater->dsadr = dma;
586 	updater->dtadr = dma + 8;
587 	updater->dcmd = PXA_DCMD_WIDTH4 | PXA_DCMD_BURST32 |
588 		(PXA_DCMD_LENGTH & sizeof(u32));
589 	if (flags & DMA_PREP_INTERRUPT)
590 		updater->dcmd |= PXA_DCMD_ENDIRQEN;
591 	if (sw_desc->cyclic)
592 		sw_desc->hw_desc[sw_desc->nb_desc - 2]->ddadr = sw_desc->first;
593 }
594 
595 static bool is_desc_completed(struct virt_dma_desc *vd)
596 {
597 	struct pxad_desc_sw *sw_desc = to_pxad_sw_desc(vd);
598 	struct pxad_desc_hw *updater =
599 		sw_desc->hw_desc[sw_desc->nb_desc - 1];
600 
601 	return updater->dtadr != (updater->dsadr + 8);
602 }
603 
604 static void pxad_desc_chain(struct virt_dma_desc *vd1,
605 				struct virt_dma_desc *vd2)
606 {
607 	struct pxad_desc_sw *desc1 = to_pxad_sw_desc(vd1);
608 	struct pxad_desc_sw *desc2 = to_pxad_sw_desc(vd2);
609 	dma_addr_t dma_to_chain;
610 
611 	dma_to_chain = desc2->first;
612 	desc1->hw_desc[desc1->nb_desc - 1]->ddadr = dma_to_chain;
613 }
614 
615 static bool pxad_try_hotchain(struct virt_dma_chan *vc,
616 				  struct virt_dma_desc *vd)
617 {
618 	struct virt_dma_desc *vd_last_issued = NULL;
619 	struct pxad_chan *chan = to_pxad_chan(&vc->chan);
620 
621 	/*
622 	 * Attempt to hot chain the tx if the phy is still running. This is
623 	 * considered successful only if either the channel is still running
624 	 * after the chaining, or if the chained transfer is completed after
625 	 * having been hot chained.
626 	 * A change of alignment is not allowed, and forbids hotchaining.
627 	 */
628 	if (is_chan_running(chan)) {
629 		BUG_ON(list_empty(&vc->desc_issued));
630 
631 		if (!is_running_chan_misaligned(chan) &&
632 		    to_pxad_sw_desc(vd)->misaligned)
633 			return false;
634 
635 		vd_last_issued = list_entry(vc->desc_issued.prev,
636 					    struct virt_dma_desc, node);
637 		pxad_desc_chain(vd_last_issued, vd);
638 		if (is_chan_running(chan) || is_desc_completed(vd_last_issued))
639 			return true;
640 	}
641 
642 	return false;
643 }
644 
645 static unsigned int clear_chan_irq(struct pxad_phy *phy)
646 {
647 	u32 dcsr;
648 	u32 dint = readl(phy->base + DINT);
649 
650 	if (!(dint & BIT(phy->idx)))
651 		return PXA_DCSR_RUN;
652 
653 	/* clear irq */
654 	dcsr = phy_readl_relaxed(phy, DCSR);
655 	phy_writel(phy, dcsr, DCSR);
656 	if ((dcsr & PXA_DCSR_BUSERR) && (phy->vchan))
657 		dev_warn(&phy->vchan->vc.chan.dev->device,
658 			 "%s(chan=%p): PXA_DCSR_BUSERR\n",
659 			 __func__, &phy->vchan);
660 
661 	return dcsr & ~PXA_DCSR_RUN;
662 }
663 
664 static irqreturn_t pxad_chan_handler(int irq, void *dev_id)
665 {
666 	struct pxad_phy *phy = dev_id;
667 	struct pxad_chan *chan = phy->vchan;
668 	struct virt_dma_desc *vd, *tmp;
669 	unsigned int dcsr;
670 	unsigned long flags;
671 	dma_cookie_t last_started = 0;
672 
673 	BUG_ON(!chan);
674 
675 	dcsr = clear_chan_irq(phy);
676 	if (dcsr & PXA_DCSR_RUN)
677 		return IRQ_NONE;
678 
679 	spin_lock_irqsave(&chan->vc.lock, flags);
680 	list_for_each_entry_safe(vd, tmp, &chan->vc.desc_issued, node) {
681 		dev_dbg(&chan->vc.chan.dev->device,
682 			"%s(): checking txd %p[%x]: completed=%d\n",
683 			__func__, vd, vd->tx.cookie, is_desc_completed(vd));
684 		last_started = vd->tx.cookie;
685 		if (to_pxad_sw_desc(vd)->cyclic) {
686 			vchan_cyclic_callback(vd);
687 			break;
688 		}
689 		if (is_desc_completed(vd)) {
690 			list_del(&vd->node);
691 			vchan_cookie_complete(vd);
692 		} else {
693 			break;
694 		}
695 	}
696 
697 	if (dcsr & PXA_DCSR_BUSERR) {
698 		chan->bus_error = last_started;
699 		phy_disable(phy);
700 	}
701 
702 	if (!chan->bus_error && dcsr & PXA_DCSR_STOPSTATE) {
703 		dev_dbg(&chan->vc.chan.dev->device,
704 		"%s(): channel stopped, submitted_empty=%d issued_empty=%d",
705 			__func__,
706 			list_empty(&chan->vc.desc_submitted),
707 			list_empty(&chan->vc.desc_issued));
708 		phy_writel_relaxed(phy, dcsr & ~PXA_DCSR_STOPIRQEN, DCSR);
709 
710 		if (list_empty(&chan->vc.desc_issued)) {
711 			chan->misaligned =
712 				!list_empty(&chan->vc.desc_submitted);
713 		} else {
714 			vd = list_first_entry(&chan->vc.desc_issued,
715 					      struct virt_dma_desc, node);
716 			pxad_launch_chan(chan, to_pxad_sw_desc(vd));
717 		}
718 	}
719 	spin_unlock_irqrestore(&chan->vc.lock, flags);
720 
721 	return IRQ_HANDLED;
722 }
723 
724 static irqreturn_t pxad_int_handler(int irq, void *dev_id)
725 {
726 	struct pxad_device *pdev = dev_id;
727 	struct pxad_phy *phy;
728 	u32 dint = readl(pdev->base + DINT);
729 	int i, ret = IRQ_NONE;
730 
731 	while (dint) {
732 		i = __ffs(dint);
733 		dint &= (dint - 1);
734 		phy = &pdev->phys[i];
735 		if ((i < 32) && (legacy_reserved & BIT(i)))
736 			continue;
737 		if (pxad_chan_handler(irq, phy) == IRQ_HANDLED)
738 			ret = IRQ_HANDLED;
739 	}
740 
741 	return ret;
742 }
743 
744 static int pxad_alloc_chan_resources(struct dma_chan *dchan)
745 {
746 	struct pxad_chan *chan = to_pxad_chan(dchan);
747 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
748 
749 	if (chan->desc_pool)
750 		return 1;
751 
752 	chan->desc_pool = dma_pool_create(dma_chan_name(dchan),
753 					  pdev->slave.dev,
754 					  sizeof(struct pxad_desc_hw),
755 					  __alignof__(struct pxad_desc_hw),
756 					  0);
757 	if (!chan->desc_pool) {
758 		dev_err(&chan->vc.chan.dev->device,
759 			"%s(): unable to allocate descriptor pool\n",
760 			__func__);
761 		return -ENOMEM;
762 	}
763 
764 	return 1;
765 }
766 
767 static void pxad_free_chan_resources(struct dma_chan *dchan)
768 {
769 	struct pxad_chan *chan = to_pxad_chan(dchan);
770 
771 	vchan_free_chan_resources(&chan->vc);
772 	dma_pool_destroy(chan->desc_pool);
773 	chan->desc_pool = NULL;
774 
775 }
776 
777 static void pxad_free_desc(struct virt_dma_desc *vd)
778 {
779 	int i;
780 	dma_addr_t dma;
781 	struct pxad_desc_sw *sw_desc = to_pxad_sw_desc(vd);
782 
783 	BUG_ON(sw_desc->nb_desc == 0);
784 	for (i = sw_desc->nb_desc - 1; i >= 0; i--) {
785 		if (i > 0)
786 			dma = sw_desc->hw_desc[i - 1]->ddadr;
787 		else
788 			dma = sw_desc->first;
789 		dma_pool_free(sw_desc->desc_pool,
790 			      sw_desc->hw_desc[i], dma);
791 	}
792 	sw_desc->nb_desc = 0;
793 	kfree(sw_desc);
794 }
795 
796 static struct pxad_desc_sw *
797 pxad_alloc_desc(struct pxad_chan *chan, unsigned int nb_hw_desc)
798 {
799 	struct pxad_desc_sw *sw_desc;
800 	dma_addr_t dma;
801 	int i;
802 
803 	sw_desc = kzalloc(sizeof(*sw_desc) +
804 			  nb_hw_desc * sizeof(struct pxad_desc_hw *),
805 			  GFP_NOWAIT);
806 	if (!sw_desc)
807 		return NULL;
808 	sw_desc->desc_pool = chan->desc_pool;
809 
810 	for (i = 0; i < nb_hw_desc; i++) {
811 		sw_desc->hw_desc[i] = dma_pool_alloc(sw_desc->desc_pool,
812 						     GFP_NOWAIT, &dma);
813 		if (!sw_desc->hw_desc[i]) {
814 			dev_err(&chan->vc.chan.dev->device,
815 				"%s(): Couldn't allocate the %dth hw_desc from dma_pool %p\n",
816 				__func__, i, sw_desc->desc_pool);
817 			goto err;
818 		}
819 
820 		if (i == 0)
821 			sw_desc->first = dma;
822 		else
823 			sw_desc->hw_desc[i - 1]->ddadr = dma;
824 		sw_desc->nb_desc++;
825 	}
826 
827 	return sw_desc;
828 err:
829 	pxad_free_desc(&sw_desc->vd);
830 	return NULL;
831 }
832 
833 static dma_cookie_t pxad_tx_submit(struct dma_async_tx_descriptor *tx)
834 {
835 	struct virt_dma_chan *vc = to_virt_chan(tx->chan);
836 	struct pxad_chan *chan = to_pxad_chan(&vc->chan);
837 	struct virt_dma_desc *vd_chained = NULL,
838 		*vd = container_of(tx, struct virt_dma_desc, tx);
839 	dma_cookie_t cookie;
840 	unsigned long flags;
841 
842 	set_updater_desc(to_pxad_sw_desc(vd), tx->flags);
843 
844 	spin_lock_irqsave(&vc->lock, flags);
845 	cookie = dma_cookie_assign(tx);
846 
847 	if (list_empty(&vc->desc_submitted) && pxad_try_hotchain(vc, vd)) {
848 		list_move_tail(&vd->node, &vc->desc_issued);
849 		dev_dbg(&chan->vc.chan.dev->device,
850 			"%s(): txd %p[%x]: submitted (hot linked)\n",
851 			__func__, vd, cookie);
852 		goto out;
853 	}
854 
855 	/*
856 	 * Fallback to placing the tx in the submitted queue
857 	 */
858 	if (!list_empty(&vc->desc_submitted)) {
859 		vd_chained = list_entry(vc->desc_submitted.prev,
860 					struct virt_dma_desc, node);
861 		/*
862 		 * Only chain the descriptors if no new misalignment is
863 		 * introduced. If a new misalignment is chained, let the channel
864 		 * stop, and be relaunched in misalign mode from the irq
865 		 * handler.
866 		 */
867 		if (chan->misaligned || !to_pxad_sw_desc(vd)->misaligned)
868 			pxad_desc_chain(vd_chained, vd);
869 		else
870 			vd_chained = NULL;
871 	}
872 	dev_dbg(&chan->vc.chan.dev->device,
873 		"%s(): txd %p[%x]: submitted (%s linked)\n",
874 		__func__, vd, cookie, vd_chained ? "cold" : "not");
875 	list_move_tail(&vd->node, &vc->desc_submitted);
876 	chan->misaligned |= to_pxad_sw_desc(vd)->misaligned;
877 
878 out:
879 	spin_unlock_irqrestore(&vc->lock, flags);
880 	return cookie;
881 }
882 
883 static void pxad_issue_pending(struct dma_chan *dchan)
884 {
885 	struct pxad_chan *chan = to_pxad_chan(dchan);
886 	struct virt_dma_desc *vd_first;
887 	unsigned long flags;
888 
889 	spin_lock_irqsave(&chan->vc.lock, flags);
890 	if (list_empty(&chan->vc.desc_submitted))
891 		goto out;
892 
893 	vd_first = list_first_entry(&chan->vc.desc_submitted,
894 				    struct virt_dma_desc, node);
895 	dev_dbg(&chan->vc.chan.dev->device,
896 		"%s(): txd %p[%x]", __func__, vd_first, vd_first->tx.cookie);
897 
898 	vchan_issue_pending(&chan->vc);
899 	if (!pxad_try_hotchain(&chan->vc, vd_first))
900 		pxad_launch_chan(chan, to_pxad_sw_desc(vd_first));
901 out:
902 	spin_unlock_irqrestore(&chan->vc.lock, flags);
903 }
904 
905 static inline struct dma_async_tx_descriptor *
906 pxad_tx_prep(struct virt_dma_chan *vc, struct virt_dma_desc *vd,
907 		 unsigned long tx_flags)
908 {
909 	struct dma_async_tx_descriptor *tx;
910 	struct pxad_chan *chan = container_of(vc, struct pxad_chan, vc);
911 
912 	INIT_LIST_HEAD(&vd->node);
913 	tx = vchan_tx_prep(vc, vd, tx_flags);
914 	tx->tx_submit = pxad_tx_submit;
915 	dev_dbg(&chan->vc.chan.dev->device,
916 		"%s(): vc=%p txd=%p[%x] flags=0x%lx\n", __func__,
917 		vc, vd, vd->tx.cookie,
918 		tx_flags);
919 
920 	return tx;
921 }
922 
923 static void pxad_get_config(struct pxad_chan *chan,
924 			    enum dma_transfer_direction dir,
925 			    u32 *dcmd, u32 *dev_src, u32 *dev_dst)
926 {
927 	u32 maxburst = 0, dev_addr = 0;
928 	enum dma_slave_buswidth width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
929 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
930 
931 	*dcmd = 0;
932 	if (dir == DMA_DEV_TO_MEM) {
933 		maxburst = chan->cfg.src_maxburst;
934 		width = chan->cfg.src_addr_width;
935 		dev_addr = chan->cfg.src_addr;
936 		*dev_src = dev_addr;
937 		*dcmd |= PXA_DCMD_INCTRGADDR;
938 		if (chan->drcmr <= pdev->nr_requestors)
939 			*dcmd |= PXA_DCMD_FLOWSRC;
940 	}
941 	if (dir == DMA_MEM_TO_DEV) {
942 		maxburst = chan->cfg.dst_maxburst;
943 		width = chan->cfg.dst_addr_width;
944 		dev_addr = chan->cfg.dst_addr;
945 		*dev_dst = dev_addr;
946 		*dcmd |= PXA_DCMD_INCSRCADDR;
947 		if (chan->drcmr <= pdev->nr_requestors)
948 			*dcmd |= PXA_DCMD_FLOWTRG;
949 	}
950 	if (dir == DMA_MEM_TO_MEM)
951 		*dcmd |= PXA_DCMD_BURST32 | PXA_DCMD_INCTRGADDR |
952 			PXA_DCMD_INCSRCADDR;
953 
954 	dev_dbg(&chan->vc.chan.dev->device,
955 		"%s(): dev_addr=0x%x maxburst=%d width=%d  dir=%d\n",
956 		__func__, dev_addr, maxburst, width, dir);
957 
958 	if (width == DMA_SLAVE_BUSWIDTH_1_BYTE)
959 		*dcmd |= PXA_DCMD_WIDTH1;
960 	else if (width == DMA_SLAVE_BUSWIDTH_2_BYTES)
961 		*dcmd |= PXA_DCMD_WIDTH2;
962 	else if (width == DMA_SLAVE_BUSWIDTH_4_BYTES)
963 		*dcmd |= PXA_DCMD_WIDTH4;
964 
965 	if (maxburst == 8)
966 		*dcmd |= PXA_DCMD_BURST8;
967 	else if (maxburst == 16)
968 		*dcmd |= PXA_DCMD_BURST16;
969 	else if (maxburst == 32)
970 		*dcmd |= PXA_DCMD_BURST32;
971 
972 	/* FIXME: drivers should be ported over to use the filter
973 	 * function. Once that's done, the following two lines can
974 	 * be removed.
975 	 */
976 	if (chan->cfg.slave_id)
977 		chan->drcmr = chan->cfg.slave_id;
978 }
979 
980 static struct dma_async_tx_descriptor *
981 pxad_prep_memcpy(struct dma_chan *dchan,
982 		 dma_addr_t dma_dst, dma_addr_t dma_src,
983 		 size_t len, unsigned long flags)
984 {
985 	struct pxad_chan *chan = to_pxad_chan(dchan);
986 	struct pxad_desc_sw *sw_desc;
987 	struct pxad_desc_hw *hw_desc;
988 	u32 dcmd;
989 	unsigned int i, nb_desc = 0;
990 	size_t copy;
991 
992 	if (!dchan || !len)
993 		return NULL;
994 
995 	dev_dbg(&chan->vc.chan.dev->device,
996 		"%s(): dma_dst=0x%lx dma_src=0x%lx len=%zu flags=%lx\n",
997 		__func__, (unsigned long)dma_dst, (unsigned long)dma_src,
998 		len, flags);
999 	pxad_get_config(chan, DMA_MEM_TO_MEM, &dcmd, NULL, NULL);
1000 
1001 	nb_desc = DIV_ROUND_UP(len, PDMA_MAX_DESC_BYTES);
1002 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
1003 	if (!sw_desc)
1004 		return NULL;
1005 	sw_desc->len = len;
1006 
1007 	if (!IS_ALIGNED(dma_src, 1 << PDMA_ALIGNMENT) ||
1008 	    !IS_ALIGNED(dma_dst, 1 << PDMA_ALIGNMENT))
1009 		sw_desc->misaligned = true;
1010 
1011 	i = 0;
1012 	do {
1013 		hw_desc = sw_desc->hw_desc[i++];
1014 		copy = min_t(size_t, len, PDMA_MAX_DESC_BYTES);
1015 		hw_desc->dcmd = dcmd | (PXA_DCMD_LENGTH & copy);
1016 		hw_desc->dsadr = dma_src;
1017 		hw_desc->dtadr = dma_dst;
1018 		len -= copy;
1019 		dma_src += copy;
1020 		dma_dst += copy;
1021 	} while (len);
1022 	set_updater_desc(sw_desc, flags);
1023 
1024 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
1025 }
1026 
1027 static struct dma_async_tx_descriptor *
1028 pxad_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
1029 		   unsigned int sg_len, enum dma_transfer_direction dir,
1030 		   unsigned long flags, void *context)
1031 {
1032 	struct pxad_chan *chan = to_pxad_chan(dchan);
1033 	struct pxad_desc_sw *sw_desc;
1034 	size_t len, avail;
1035 	struct scatterlist *sg;
1036 	dma_addr_t dma;
1037 	u32 dcmd, dsadr = 0, dtadr = 0;
1038 	unsigned int nb_desc = 0, i, j = 0;
1039 
1040 	if ((sgl == NULL) || (sg_len == 0))
1041 		return NULL;
1042 
1043 	pxad_get_config(chan, dir, &dcmd, &dsadr, &dtadr);
1044 	dev_dbg(&chan->vc.chan.dev->device,
1045 		"%s(): dir=%d flags=%lx\n", __func__, dir, flags);
1046 
1047 	for_each_sg(sgl, sg, sg_len, i)
1048 		nb_desc += DIV_ROUND_UP(sg_dma_len(sg), PDMA_MAX_DESC_BYTES);
1049 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
1050 	if (!sw_desc)
1051 		return NULL;
1052 
1053 	for_each_sg(sgl, sg, sg_len, i) {
1054 		dma = sg_dma_address(sg);
1055 		avail = sg_dma_len(sg);
1056 		sw_desc->len += avail;
1057 
1058 		do {
1059 			len = min_t(size_t, avail, PDMA_MAX_DESC_BYTES);
1060 			if (dma & 0x7)
1061 				sw_desc->misaligned = true;
1062 
1063 			sw_desc->hw_desc[j]->dcmd =
1064 				dcmd | (PXA_DCMD_LENGTH & len);
1065 			sw_desc->hw_desc[j]->dsadr = dsadr ? dsadr : dma;
1066 			sw_desc->hw_desc[j++]->dtadr = dtadr ? dtadr : dma;
1067 
1068 			dma += len;
1069 			avail -= len;
1070 		} while (avail);
1071 	}
1072 	set_updater_desc(sw_desc, flags);
1073 
1074 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
1075 }
1076 
1077 static struct dma_async_tx_descriptor *
1078 pxad_prep_dma_cyclic(struct dma_chan *dchan,
1079 		     dma_addr_t buf_addr, size_t len, size_t period_len,
1080 		     enum dma_transfer_direction dir, unsigned long flags)
1081 {
1082 	struct pxad_chan *chan = to_pxad_chan(dchan);
1083 	struct pxad_desc_sw *sw_desc;
1084 	struct pxad_desc_hw **phw_desc;
1085 	dma_addr_t dma;
1086 	u32 dcmd, dsadr = 0, dtadr = 0;
1087 	unsigned int nb_desc = 0;
1088 
1089 	if (!dchan || !len || !period_len)
1090 		return NULL;
1091 	if ((dir != DMA_DEV_TO_MEM) && (dir != DMA_MEM_TO_DEV)) {
1092 		dev_err(&chan->vc.chan.dev->device,
1093 			"Unsupported direction for cyclic DMA\n");
1094 		return NULL;
1095 	}
1096 	/* the buffer length must be a multiple of period_len */
1097 	if (len % period_len != 0 || period_len > PDMA_MAX_DESC_BYTES ||
1098 	    !IS_ALIGNED(period_len, 1 << PDMA_ALIGNMENT))
1099 		return NULL;
1100 
1101 	pxad_get_config(chan, dir, &dcmd, &dsadr, &dtadr);
1102 	dcmd |= PXA_DCMD_ENDIRQEN | (PXA_DCMD_LENGTH & period_len);
1103 	dev_dbg(&chan->vc.chan.dev->device,
1104 		"%s(): buf_addr=0x%lx len=%zu period=%zu dir=%d flags=%lx\n",
1105 		__func__, (unsigned long)buf_addr, len, period_len, dir, flags);
1106 
1107 	nb_desc = DIV_ROUND_UP(period_len, PDMA_MAX_DESC_BYTES);
1108 	nb_desc *= DIV_ROUND_UP(len, period_len);
1109 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
1110 	if (!sw_desc)
1111 		return NULL;
1112 	sw_desc->cyclic = true;
1113 	sw_desc->len = len;
1114 
1115 	phw_desc = sw_desc->hw_desc;
1116 	dma = buf_addr;
1117 	do {
1118 		phw_desc[0]->dsadr = dsadr ? dsadr : dma;
1119 		phw_desc[0]->dtadr = dtadr ? dtadr : dma;
1120 		phw_desc[0]->dcmd = dcmd;
1121 		phw_desc++;
1122 		dma += period_len;
1123 		len -= period_len;
1124 	} while (len);
1125 	set_updater_desc(sw_desc, flags);
1126 
1127 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
1128 }
1129 
1130 static int pxad_config(struct dma_chan *dchan,
1131 		       struct dma_slave_config *cfg)
1132 {
1133 	struct pxad_chan *chan = to_pxad_chan(dchan);
1134 
1135 	if (!dchan)
1136 		return -EINVAL;
1137 
1138 	chan->cfg = *cfg;
1139 	return 0;
1140 }
1141 
1142 static int pxad_terminate_all(struct dma_chan *dchan)
1143 {
1144 	struct pxad_chan *chan = to_pxad_chan(dchan);
1145 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
1146 	struct virt_dma_desc *vd = NULL;
1147 	unsigned long flags;
1148 	struct pxad_phy *phy;
1149 	LIST_HEAD(head);
1150 
1151 	dev_dbg(&chan->vc.chan.dev->device,
1152 		"%s(): vchan %p: terminate all\n", __func__, &chan->vc);
1153 
1154 	spin_lock_irqsave(&chan->vc.lock, flags);
1155 	vchan_get_all_descriptors(&chan->vc, &head);
1156 
1157 	list_for_each_entry(vd, &head, node) {
1158 		dev_dbg(&chan->vc.chan.dev->device,
1159 			"%s(): cancelling txd %p[%x] (completed=%d)", __func__,
1160 			vd, vd->tx.cookie, is_desc_completed(vd));
1161 	}
1162 
1163 	phy = chan->phy;
1164 	if (phy) {
1165 		phy_disable(chan->phy);
1166 		pxad_free_phy(chan);
1167 		chan->phy = NULL;
1168 		spin_lock(&pdev->phy_lock);
1169 		phy->vchan = NULL;
1170 		spin_unlock(&pdev->phy_lock);
1171 	}
1172 	spin_unlock_irqrestore(&chan->vc.lock, flags);
1173 	vchan_dma_desc_free_list(&chan->vc, &head);
1174 
1175 	return 0;
1176 }
1177 
1178 static unsigned int pxad_residue(struct pxad_chan *chan,
1179 				 dma_cookie_t cookie)
1180 {
1181 	struct virt_dma_desc *vd = NULL;
1182 	struct pxad_desc_sw *sw_desc = NULL;
1183 	struct pxad_desc_hw *hw_desc = NULL;
1184 	u32 curr, start, len, end, residue = 0;
1185 	unsigned long flags;
1186 	bool passed = false;
1187 	int i;
1188 
1189 	/*
1190 	 * If the channel does not have a phy pointer anymore, it has already
1191 	 * been completed. Therefore, its residue is 0.
1192 	 */
1193 	if (!chan->phy)
1194 		return 0;
1195 
1196 	spin_lock_irqsave(&chan->vc.lock, flags);
1197 
1198 	vd = vchan_find_desc(&chan->vc, cookie);
1199 	if (!vd)
1200 		goto out;
1201 
1202 	sw_desc = to_pxad_sw_desc(vd);
1203 	if (sw_desc->hw_desc[0]->dcmd & PXA_DCMD_INCSRCADDR)
1204 		curr = phy_readl_relaxed(chan->phy, DSADR);
1205 	else
1206 		curr = phy_readl_relaxed(chan->phy, DTADR);
1207 
1208 	/*
1209 	 * curr has to be actually read before checking descriptor
1210 	 * completion, so that a curr inside a status updater
1211 	 * descriptor implies the following test returns true, and
1212 	 * preventing reordering of curr load and the test.
1213 	 */
1214 	rmb();
1215 	if (is_desc_completed(vd))
1216 		goto out;
1217 
1218 	for (i = 0; i < sw_desc->nb_desc - 1; i++) {
1219 		hw_desc = sw_desc->hw_desc[i];
1220 		if (sw_desc->hw_desc[0]->dcmd & PXA_DCMD_INCSRCADDR)
1221 			start = hw_desc->dsadr;
1222 		else
1223 			start = hw_desc->dtadr;
1224 		len = hw_desc->dcmd & PXA_DCMD_LENGTH;
1225 		end = start + len;
1226 
1227 		/*
1228 		 * 'passed' will be latched once we found the descriptor
1229 		 * which lies inside the boundaries of the curr
1230 		 * pointer. All descriptors that occur in the list
1231 		 * _after_ we found that partially handled descriptor
1232 		 * are still to be processed and are hence added to the
1233 		 * residual bytes counter.
1234 		 */
1235 
1236 		if (passed) {
1237 			residue += len;
1238 		} else if (curr >= start && curr <= end) {
1239 			residue += end - curr;
1240 			passed = true;
1241 		}
1242 	}
1243 	if (!passed)
1244 		residue = sw_desc->len;
1245 
1246 out:
1247 	spin_unlock_irqrestore(&chan->vc.lock, flags);
1248 	dev_dbg(&chan->vc.chan.dev->device,
1249 		"%s(): txd %p[%x] sw_desc=%p: %d\n",
1250 		__func__, vd, cookie, sw_desc, residue);
1251 	return residue;
1252 }
1253 
1254 static enum dma_status pxad_tx_status(struct dma_chan *dchan,
1255 				      dma_cookie_t cookie,
1256 				      struct dma_tx_state *txstate)
1257 {
1258 	struct pxad_chan *chan = to_pxad_chan(dchan);
1259 	enum dma_status ret;
1260 
1261 	if (cookie == chan->bus_error)
1262 		return DMA_ERROR;
1263 
1264 	ret = dma_cookie_status(dchan, cookie, txstate);
1265 	if (likely(txstate && (ret != DMA_ERROR)))
1266 		dma_set_residue(txstate, pxad_residue(chan, cookie));
1267 
1268 	return ret;
1269 }
1270 
1271 static void pxad_free_channels(struct dma_device *dmadev)
1272 {
1273 	struct pxad_chan *c, *cn;
1274 
1275 	list_for_each_entry_safe(c, cn, &dmadev->channels,
1276 				 vc.chan.device_node) {
1277 		list_del(&c->vc.chan.device_node);
1278 		tasklet_kill(&c->vc.task);
1279 	}
1280 }
1281 
1282 static int pxad_remove(struct platform_device *op)
1283 {
1284 	struct pxad_device *pdev = platform_get_drvdata(op);
1285 
1286 	pxad_cleanup_debugfs(pdev);
1287 	pxad_free_channels(&pdev->slave);
1288 	dma_async_device_unregister(&pdev->slave);
1289 	return 0;
1290 }
1291 
1292 static int pxad_init_phys(struct platform_device *op,
1293 			  struct pxad_device *pdev,
1294 			  unsigned int nb_phy_chans)
1295 {
1296 	int irq0, irq, nr_irq = 0, i, ret;
1297 	struct pxad_phy *phy;
1298 
1299 	irq0 = platform_get_irq(op, 0);
1300 	if (irq0 < 0)
1301 		return irq0;
1302 
1303 	pdev->phys = devm_kcalloc(&op->dev, nb_phy_chans,
1304 				  sizeof(pdev->phys[0]), GFP_KERNEL);
1305 	if (!pdev->phys)
1306 		return -ENOMEM;
1307 
1308 	for (i = 0; i < nb_phy_chans; i++)
1309 		if (platform_get_irq(op, i) > 0)
1310 			nr_irq++;
1311 
1312 	for (i = 0; i < nb_phy_chans; i++) {
1313 		phy = &pdev->phys[i];
1314 		phy->base = pdev->base;
1315 		phy->idx = i;
1316 		irq = platform_get_irq(op, i);
1317 		if ((nr_irq > 1) && (irq > 0))
1318 			ret = devm_request_irq(&op->dev, irq,
1319 					       pxad_chan_handler,
1320 					       IRQF_SHARED, "pxa-dma", phy);
1321 		if ((nr_irq == 1) && (i == 0))
1322 			ret = devm_request_irq(&op->dev, irq0,
1323 					       pxad_int_handler,
1324 					       IRQF_SHARED, "pxa-dma", pdev);
1325 		if (ret) {
1326 			dev_err(pdev->slave.dev,
1327 				"%s(): can't request irq %d:%d\n", __func__,
1328 				irq, ret);
1329 			return ret;
1330 		}
1331 	}
1332 
1333 	return 0;
1334 }
1335 
1336 static const struct of_device_id pxad_dt_ids[] = {
1337 	{ .compatible = "marvell,pdma-1.0", },
1338 	{}
1339 };
1340 MODULE_DEVICE_TABLE(of, pxad_dt_ids);
1341 
1342 static struct dma_chan *pxad_dma_xlate(struct of_phandle_args *dma_spec,
1343 					   struct of_dma *ofdma)
1344 {
1345 	struct pxad_device *d = ofdma->of_dma_data;
1346 	struct dma_chan *chan;
1347 
1348 	chan = dma_get_any_slave_channel(&d->slave);
1349 	if (!chan)
1350 		return NULL;
1351 
1352 	to_pxad_chan(chan)->drcmr = dma_spec->args[0];
1353 	to_pxad_chan(chan)->prio = dma_spec->args[1];
1354 
1355 	return chan;
1356 }
1357 
1358 static int pxad_init_dmadev(struct platform_device *op,
1359 			    struct pxad_device *pdev,
1360 			    unsigned int nr_phy_chans,
1361 			    unsigned int nr_requestors)
1362 {
1363 	int ret;
1364 	unsigned int i;
1365 	struct pxad_chan *c;
1366 
1367 	pdev->nr_chans = nr_phy_chans;
1368 	pdev->nr_requestors = nr_requestors;
1369 	INIT_LIST_HEAD(&pdev->slave.channels);
1370 	pdev->slave.device_alloc_chan_resources = pxad_alloc_chan_resources;
1371 	pdev->slave.device_free_chan_resources = pxad_free_chan_resources;
1372 	pdev->slave.device_tx_status = pxad_tx_status;
1373 	pdev->slave.device_issue_pending = pxad_issue_pending;
1374 	pdev->slave.device_config = pxad_config;
1375 	pdev->slave.device_terminate_all = pxad_terminate_all;
1376 
1377 	if (op->dev.coherent_dma_mask)
1378 		dma_set_mask(&op->dev, op->dev.coherent_dma_mask);
1379 	else
1380 		dma_set_mask(&op->dev, DMA_BIT_MASK(32));
1381 
1382 	ret = pxad_init_phys(op, pdev, nr_phy_chans);
1383 	if (ret)
1384 		return ret;
1385 
1386 	for (i = 0; i < nr_phy_chans; i++) {
1387 		c = devm_kzalloc(&op->dev, sizeof(*c), GFP_KERNEL);
1388 		if (!c)
1389 			return -ENOMEM;
1390 		c->vc.desc_free = pxad_free_desc;
1391 		vchan_init(&c->vc, &pdev->slave);
1392 	}
1393 
1394 	return dma_async_device_register(&pdev->slave);
1395 }
1396 
1397 static int pxad_probe(struct platform_device *op)
1398 {
1399 	struct pxad_device *pdev;
1400 	const struct of_device_id *of_id;
1401 	struct mmp_dma_platdata *pdata = dev_get_platdata(&op->dev);
1402 	struct resource *iores;
1403 	int ret, dma_channels = 0, nb_requestors = 0;
1404 	const enum dma_slave_buswidth widths =
1405 		DMA_SLAVE_BUSWIDTH_1_BYTE   | DMA_SLAVE_BUSWIDTH_2_BYTES |
1406 		DMA_SLAVE_BUSWIDTH_4_BYTES;
1407 
1408 	pdev = devm_kzalloc(&op->dev, sizeof(*pdev), GFP_KERNEL);
1409 	if (!pdev)
1410 		return -ENOMEM;
1411 
1412 	spin_lock_init(&pdev->phy_lock);
1413 
1414 	iores = platform_get_resource(op, IORESOURCE_MEM, 0);
1415 	pdev->base = devm_ioremap_resource(&op->dev, iores);
1416 	if (IS_ERR(pdev->base))
1417 		return PTR_ERR(pdev->base);
1418 
1419 	of_id = of_match_device(pxad_dt_ids, &op->dev);
1420 	if (of_id) {
1421 		of_property_read_u32(op->dev.of_node, "#dma-channels",
1422 				     &dma_channels);
1423 		ret = of_property_read_u32(op->dev.of_node, "#dma-requests",
1424 					   &nb_requestors);
1425 		if (ret) {
1426 			dev_warn(pdev->slave.dev,
1427 				 "#dma-requests set to default 32 as missing in OF: %d",
1428 				 ret);
1429 			nb_requestors = 32;
1430 		};
1431 	} else if (pdata && pdata->dma_channels) {
1432 		dma_channels = pdata->dma_channels;
1433 		nb_requestors = pdata->nb_requestors;
1434 	} else {
1435 		dma_channels = 32;	/* default 32 channel */
1436 	}
1437 
1438 	dma_cap_set(DMA_SLAVE, pdev->slave.cap_mask);
1439 	dma_cap_set(DMA_MEMCPY, pdev->slave.cap_mask);
1440 	dma_cap_set(DMA_CYCLIC, pdev->slave.cap_mask);
1441 	dma_cap_set(DMA_PRIVATE, pdev->slave.cap_mask);
1442 	pdev->slave.device_prep_dma_memcpy = pxad_prep_memcpy;
1443 	pdev->slave.device_prep_slave_sg = pxad_prep_slave_sg;
1444 	pdev->slave.device_prep_dma_cyclic = pxad_prep_dma_cyclic;
1445 
1446 	pdev->slave.copy_align = PDMA_ALIGNMENT;
1447 	pdev->slave.src_addr_widths = widths;
1448 	pdev->slave.dst_addr_widths = widths;
1449 	pdev->slave.directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
1450 	pdev->slave.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
1451 	pdev->slave.descriptor_reuse = true;
1452 
1453 	pdev->slave.dev = &op->dev;
1454 	ret = pxad_init_dmadev(op, pdev, dma_channels, nb_requestors);
1455 	if (ret) {
1456 		dev_err(pdev->slave.dev, "unable to register\n");
1457 		return ret;
1458 	}
1459 
1460 	if (op->dev.of_node) {
1461 		/* Device-tree DMA controller registration */
1462 		ret = of_dma_controller_register(op->dev.of_node,
1463 						 pxad_dma_xlate, pdev);
1464 		if (ret < 0) {
1465 			dev_err(pdev->slave.dev,
1466 				"of_dma_controller_register failed\n");
1467 			return ret;
1468 		}
1469 	}
1470 
1471 	platform_set_drvdata(op, pdev);
1472 	pxad_init_debugfs(pdev);
1473 	dev_info(pdev->slave.dev, "initialized %d channels on %d requestors\n",
1474 		 dma_channels, nb_requestors);
1475 	return 0;
1476 }
1477 
1478 static const struct platform_device_id pxad_id_table[] = {
1479 	{ "pxa-dma", },
1480 	{ },
1481 };
1482 
1483 static struct platform_driver pxad_driver = {
1484 	.driver		= {
1485 		.name	= "pxa-dma",
1486 		.of_match_table = pxad_dt_ids,
1487 	},
1488 	.id_table	= pxad_id_table,
1489 	.probe		= pxad_probe,
1490 	.remove		= pxad_remove,
1491 };
1492 
1493 bool pxad_filter_fn(struct dma_chan *chan, void *param)
1494 {
1495 	struct pxad_chan *c = to_pxad_chan(chan);
1496 	struct pxad_param *p = param;
1497 
1498 	if (chan->device->dev->driver != &pxad_driver.driver)
1499 		return false;
1500 
1501 	c->drcmr = p->drcmr;
1502 	c->prio = p->prio;
1503 
1504 	return true;
1505 }
1506 EXPORT_SYMBOL_GPL(pxad_filter_fn);
1507 
1508 int pxad_toggle_reserved_channel(int legacy_channel)
1509 {
1510 	if (legacy_unavailable & (BIT(legacy_channel)))
1511 		return -EBUSY;
1512 	legacy_reserved ^= BIT(legacy_channel);
1513 	return 0;
1514 }
1515 EXPORT_SYMBOL_GPL(pxad_toggle_reserved_channel);
1516 
1517 module_platform_driver(pxad_driver);
1518 
1519 MODULE_DESCRIPTION("Marvell PXA Peripheral DMA Driver");
1520 MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");
1521 MODULE_LICENSE("GPL v2");
1522