xref: /linux/drivers/dma/pxa_dma.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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 };
121 
122 struct pxad_device {
123 	struct dma_device		slave;
124 	int				nr_chans;
125 	void __iomem			*base;
126 	struct pxad_phy			*phys;
127 	spinlock_t			phy_lock;	/* Phy association */
128 #ifdef CONFIG_DEBUG_FS
129 	struct dentry			*dbgfs_root;
130 	struct dentry			*dbgfs_state;
131 	struct dentry			**dbgfs_chan;
132 #endif
133 };
134 
135 #define tx_to_pxad_desc(tx)					\
136 	container_of(tx, struct pxad_desc_sw, async_tx)
137 #define to_pxad_chan(dchan)					\
138 	container_of(dchan, struct pxad_chan, vc.chan)
139 #define to_pxad_dev(dmadev)					\
140 	container_of(dmadev, struct pxad_device, slave)
141 #define to_pxad_sw_desc(_vd)				\
142 	container_of((_vd), struct pxad_desc_sw, vd)
143 
144 #define _phy_readl_relaxed(phy, _reg)					\
145 	readl_relaxed((phy)->base + _reg((phy)->idx))
146 #define phy_readl_relaxed(phy, _reg)					\
147 	({								\
148 		u32 _v;							\
149 		_v = readl_relaxed((phy)->base + _reg((phy)->idx));	\
150 		dev_vdbg(&phy->vchan->vc.chan.dev->device,		\
151 			 "%s(): readl(%s): 0x%08x\n", __func__, #_reg,	\
152 			  _v);						\
153 		_v;							\
154 	})
155 #define phy_writel(phy, val, _reg)					\
156 	do {								\
157 		writel((val), (phy)->base + _reg((phy)->idx));		\
158 		dev_vdbg(&phy->vchan->vc.chan.dev->device,		\
159 			 "%s(): writel(0x%08x, %s)\n",			\
160 			 __func__, (u32)(val), #_reg);			\
161 	} while (0)
162 #define phy_writel_relaxed(phy, val, _reg)				\
163 	do {								\
164 		writel_relaxed((val), (phy)->base + _reg((phy)->idx));	\
165 		dev_vdbg(&phy->vchan->vc.chan.dev->device,		\
166 			 "%s(): writel_relaxed(0x%08x, %s)\n",		\
167 			 __func__, (u32)(val), #_reg);			\
168 	} while (0)
169 
170 static unsigned int pxad_drcmr(unsigned int line)
171 {
172 	if (line < 64)
173 		return 0x100 + line * 4;
174 	return 0x1000 + line * 4;
175 }
176 
177 /*
178  * Debug fs
179  */
180 #ifdef CONFIG_DEBUG_FS
181 #include <linux/debugfs.h>
182 #include <linux/uaccess.h>
183 #include <linux/seq_file.h>
184 
185 static int dbg_show_requester_chan(struct seq_file *s, void *p)
186 {
187 	struct pxad_phy *phy = s->private;
188 	int i;
189 	u32 drcmr;
190 
191 	seq_printf(s, "DMA channel %d requester :\n", phy->idx);
192 	for (i = 0; i < 70; i++) {
193 		drcmr = readl_relaxed(phy->base + pxad_drcmr(i));
194 		if ((drcmr & DRCMR_CHLNUM) == phy->idx)
195 			seq_printf(s, "\tRequester %d (MAPVLD=%d)\n", i,
196 				   !!(drcmr & DRCMR_MAPVLD));
197 	}
198 	return 0;
199 }
200 
201 static inline int dbg_burst_from_dcmd(u32 dcmd)
202 {
203 	int burst = (dcmd >> 16) & 0x3;
204 
205 	return burst ? 4 << burst : 0;
206 }
207 
208 static int is_phys_valid(unsigned long addr)
209 {
210 	return pfn_valid(__phys_to_pfn(addr));
211 }
212 
213 #define PXA_DCSR_STR(flag) (dcsr & PXA_DCSR_##flag ? #flag" " : "")
214 #define PXA_DCMD_STR(flag) (dcmd & PXA_DCMD_##flag ? #flag" " : "")
215 
216 static int dbg_show_descriptors(struct seq_file *s, void *p)
217 {
218 	struct pxad_phy *phy = s->private;
219 	int i, max_show = 20, burst, width;
220 	u32 dcmd;
221 	unsigned long phys_desc, ddadr;
222 	struct pxad_desc_hw *desc;
223 
224 	phys_desc = ddadr = _phy_readl_relaxed(phy, DDADR);
225 
226 	seq_printf(s, "DMA channel %d descriptors :\n", phy->idx);
227 	seq_printf(s, "[%03d] First descriptor unknown\n", 0);
228 	for (i = 1; i < max_show && is_phys_valid(phys_desc); i++) {
229 		desc = phys_to_virt(phys_desc);
230 		dcmd = desc->dcmd;
231 		burst = dbg_burst_from_dcmd(dcmd);
232 		width = (1 << ((dcmd >> 14) & 0x3)) >> 1;
233 
234 		seq_printf(s, "[%03d] Desc at %08lx(virt %p)\n",
235 			   i, phys_desc, desc);
236 		seq_printf(s, "\tDDADR = %08x\n", desc->ddadr);
237 		seq_printf(s, "\tDSADR = %08x\n", desc->dsadr);
238 		seq_printf(s, "\tDTADR = %08x\n", desc->dtadr);
239 		seq_printf(s, "\tDCMD  = %08x (%s%s%s%s%s%s%sburst=%d width=%d len=%d)\n",
240 			   dcmd,
241 			   PXA_DCMD_STR(INCSRCADDR), PXA_DCMD_STR(INCTRGADDR),
242 			   PXA_DCMD_STR(FLOWSRC), PXA_DCMD_STR(FLOWTRG),
243 			   PXA_DCMD_STR(STARTIRQEN), PXA_DCMD_STR(ENDIRQEN),
244 			   PXA_DCMD_STR(ENDIAN), burst, width,
245 			   dcmd & PXA_DCMD_LENGTH);
246 		phys_desc = desc->ddadr;
247 	}
248 	if (i == max_show)
249 		seq_printf(s, "[%03d] Desc at %08lx ... max display reached\n",
250 			   i, phys_desc);
251 	else
252 		seq_printf(s, "[%03d] Desc at %08lx is %s\n",
253 			   i, phys_desc, phys_desc == DDADR_STOP ?
254 			   "DDADR_STOP" : "invalid");
255 
256 	return 0;
257 }
258 
259 static int dbg_show_chan_state(struct seq_file *s, void *p)
260 {
261 	struct pxad_phy *phy = s->private;
262 	u32 dcsr, dcmd;
263 	int burst, width;
264 	static const char * const str_prio[] = {
265 		"high", "normal", "low", "invalid"
266 	};
267 
268 	dcsr = _phy_readl_relaxed(phy, DCSR);
269 	dcmd = _phy_readl_relaxed(phy, DCMD);
270 	burst = dbg_burst_from_dcmd(dcmd);
271 	width = (1 << ((dcmd >> 14) & 0x3)) >> 1;
272 
273 	seq_printf(s, "DMA channel %d\n", phy->idx);
274 	seq_printf(s, "\tPriority : %s\n",
275 			  str_prio[(phy->idx & 0xf) / 4]);
276 	seq_printf(s, "\tUnaligned transfer bit: %s\n",
277 			  _phy_readl_relaxed(phy, DALGN) & BIT(phy->idx) ?
278 			  "yes" : "no");
279 	seq_printf(s, "\tDCSR  = %08x (%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s)\n",
280 		   dcsr, PXA_DCSR_STR(RUN), PXA_DCSR_STR(NODESC),
281 		   PXA_DCSR_STR(STOPIRQEN), PXA_DCSR_STR(EORIRQEN),
282 		   PXA_DCSR_STR(EORJMPEN), PXA_DCSR_STR(EORSTOPEN),
283 		   PXA_DCSR_STR(SETCMPST), PXA_DCSR_STR(CLRCMPST),
284 		   PXA_DCSR_STR(CMPST), PXA_DCSR_STR(EORINTR),
285 		   PXA_DCSR_STR(REQPEND), PXA_DCSR_STR(STOPSTATE),
286 		   PXA_DCSR_STR(ENDINTR), PXA_DCSR_STR(STARTINTR),
287 		   PXA_DCSR_STR(BUSERR));
288 
289 	seq_printf(s, "\tDCMD  = %08x (%s%s%s%s%s%s%sburst=%d width=%d len=%d)\n",
290 		   dcmd,
291 		   PXA_DCMD_STR(INCSRCADDR), PXA_DCMD_STR(INCTRGADDR),
292 		   PXA_DCMD_STR(FLOWSRC), PXA_DCMD_STR(FLOWTRG),
293 		   PXA_DCMD_STR(STARTIRQEN), PXA_DCMD_STR(ENDIRQEN),
294 		   PXA_DCMD_STR(ENDIAN), burst, width, dcmd & PXA_DCMD_LENGTH);
295 	seq_printf(s, "\tDSADR = %08x\n", _phy_readl_relaxed(phy, DSADR));
296 	seq_printf(s, "\tDTADR = %08x\n", _phy_readl_relaxed(phy, DTADR));
297 	seq_printf(s, "\tDDADR = %08x\n", _phy_readl_relaxed(phy, DDADR));
298 
299 	return 0;
300 }
301 
302 static int dbg_show_state(struct seq_file *s, void *p)
303 {
304 	struct pxad_device *pdev = s->private;
305 
306 	/* basic device status */
307 	seq_puts(s, "DMA engine status\n");
308 	seq_printf(s, "\tChannel number: %d\n", pdev->nr_chans);
309 
310 	return 0;
311 }
312 
313 #define DBGFS_FUNC_DECL(name) \
314 static int dbg_open_##name(struct inode *inode, struct file *file) \
315 { \
316 	return single_open(file, dbg_show_##name, inode->i_private); \
317 } \
318 static const struct file_operations dbg_fops_##name = { \
319 	.owner		= THIS_MODULE, \
320 	.open		= dbg_open_##name, \
321 	.llseek		= seq_lseek, \
322 	.read		= seq_read, \
323 	.release	= single_release, \
324 }
325 
326 DBGFS_FUNC_DECL(state);
327 DBGFS_FUNC_DECL(chan_state);
328 DBGFS_FUNC_DECL(descriptors);
329 DBGFS_FUNC_DECL(requester_chan);
330 
331 static struct dentry *pxad_dbg_alloc_chan(struct pxad_device *pdev,
332 					     int ch, struct dentry *chandir)
333 {
334 	char chan_name[11];
335 	struct dentry *chan, *chan_state = NULL, *chan_descr = NULL;
336 	struct dentry *chan_reqs = NULL;
337 	void *dt;
338 
339 	scnprintf(chan_name, sizeof(chan_name), "%d", ch);
340 	chan = debugfs_create_dir(chan_name, chandir);
341 	dt = (void *)&pdev->phys[ch];
342 
343 	if (chan)
344 		chan_state = debugfs_create_file("state", 0400, chan, dt,
345 						 &dbg_fops_chan_state);
346 	if (chan_state)
347 		chan_descr = debugfs_create_file("descriptors", 0400, chan, dt,
348 						 &dbg_fops_descriptors);
349 	if (chan_descr)
350 		chan_reqs = debugfs_create_file("requesters", 0400, chan, dt,
351 						&dbg_fops_requester_chan);
352 	if (!chan_reqs)
353 		goto err_state;
354 
355 	return chan;
356 
357 err_state:
358 	debugfs_remove_recursive(chan);
359 	return NULL;
360 }
361 
362 static void pxad_init_debugfs(struct pxad_device *pdev)
363 {
364 	int i;
365 	struct dentry *chandir;
366 
367 	pdev->dbgfs_root = debugfs_create_dir(dev_name(pdev->slave.dev), NULL);
368 	if (IS_ERR(pdev->dbgfs_root) || !pdev->dbgfs_root)
369 		goto err_root;
370 
371 	pdev->dbgfs_state = debugfs_create_file("state", 0400, pdev->dbgfs_root,
372 						pdev, &dbg_fops_state);
373 	if (!pdev->dbgfs_state)
374 		goto err_state;
375 
376 	pdev->dbgfs_chan =
377 		kmalloc_array(pdev->nr_chans, sizeof(*pdev->dbgfs_state),
378 			      GFP_KERNEL);
379 	if (!pdev->dbgfs_chan)
380 		goto err_alloc;
381 
382 	chandir = debugfs_create_dir("channels", pdev->dbgfs_root);
383 	if (!chandir)
384 		goto err_chandir;
385 
386 	for (i = 0; i < pdev->nr_chans; i++) {
387 		pdev->dbgfs_chan[i] = pxad_dbg_alloc_chan(pdev, i, chandir);
388 		if (!pdev->dbgfs_chan[i])
389 			goto err_chans;
390 	}
391 
392 	return;
393 err_chans:
394 err_chandir:
395 	kfree(pdev->dbgfs_chan);
396 err_alloc:
397 err_state:
398 	debugfs_remove_recursive(pdev->dbgfs_root);
399 err_root:
400 	pr_err("pxad: debugfs is not available\n");
401 }
402 
403 static void pxad_cleanup_debugfs(struct pxad_device *pdev)
404 {
405 	debugfs_remove_recursive(pdev->dbgfs_root);
406 }
407 #else
408 static inline void pxad_init_debugfs(struct pxad_device *pdev) {}
409 static inline void pxad_cleanup_debugfs(struct pxad_device *pdev) {}
410 #endif
411 
412 /*
413  * In the transition phase where legacy pxa handling is done at the same time as
414  * mmp_dma, the DMA physical channel split between the 2 DMA providers is done
415  * through legacy_reserved. Legacy code reserves DMA channels by settings
416  * corresponding bits in legacy_reserved.
417  */
418 static u32 legacy_reserved;
419 static u32 legacy_unavailable;
420 
421 static struct pxad_phy *lookup_phy(struct pxad_chan *pchan)
422 {
423 	int prio, i;
424 	struct pxad_device *pdev = to_pxad_dev(pchan->vc.chan.device);
425 	struct pxad_phy *phy, *found = NULL;
426 	unsigned long flags;
427 
428 	/*
429 	 * dma channel priorities
430 	 * ch 0 - 3,  16 - 19  <--> (0)
431 	 * ch 4 - 7,  20 - 23  <--> (1)
432 	 * ch 8 - 11, 24 - 27  <--> (2)
433 	 * ch 12 - 15, 28 - 31  <--> (3)
434 	 */
435 
436 	spin_lock_irqsave(&pdev->phy_lock, flags);
437 	for (prio = pchan->prio; prio >= PXAD_PRIO_HIGHEST; prio--) {
438 		for (i = 0; i < pdev->nr_chans; i++) {
439 			if (prio != (i & 0xf) >> 2)
440 				continue;
441 			if ((i < 32) && (legacy_reserved & BIT(i)))
442 				continue;
443 			phy = &pdev->phys[i];
444 			if (!phy->vchan) {
445 				phy->vchan = pchan;
446 				found = phy;
447 				if (i < 32)
448 					legacy_unavailable |= BIT(i);
449 				goto out_unlock;
450 			}
451 		}
452 	}
453 
454 out_unlock:
455 	spin_unlock_irqrestore(&pdev->phy_lock, flags);
456 	dev_dbg(&pchan->vc.chan.dev->device,
457 		"%s(): phy=%p(%d)\n", __func__, found,
458 		found ? found->idx : -1);
459 
460 	return found;
461 }
462 
463 static void pxad_free_phy(struct pxad_chan *chan)
464 {
465 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
466 	unsigned long flags;
467 	u32 reg;
468 	int i;
469 
470 	dev_dbg(&chan->vc.chan.dev->device,
471 		"%s(): freeing\n", __func__);
472 	if (!chan->phy)
473 		return;
474 
475 	/* clear the channel mapping in DRCMR */
476 	if (chan->drcmr <= DRCMR_CHLNUM) {
477 		reg = pxad_drcmr(chan->drcmr);
478 		writel_relaxed(0, chan->phy->base + reg);
479 	}
480 
481 	spin_lock_irqsave(&pdev->phy_lock, flags);
482 	for (i = 0; i < 32; i++)
483 		if (chan->phy == &pdev->phys[i])
484 			legacy_unavailable &= ~BIT(i);
485 	chan->phy->vchan = NULL;
486 	chan->phy = NULL;
487 	spin_unlock_irqrestore(&pdev->phy_lock, flags);
488 }
489 
490 static bool is_chan_running(struct pxad_chan *chan)
491 {
492 	u32 dcsr;
493 	struct pxad_phy *phy = chan->phy;
494 
495 	if (!phy)
496 		return false;
497 	dcsr = phy_readl_relaxed(phy, DCSR);
498 	return dcsr & PXA_DCSR_RUN;
499 }
500 
501 static bool is_running_chan_misaligned(struct pxad_chan *chan)
502 {
503 	u32 dalgn;
504 
505 	BUG_ON(!chan->phy);
506 	dalgn = phy_readl_relaxed(chan->phy, DALGN);
507 	return dalgn & (BIT(chan->phy->idx));
508 }
509 
510 static void phy_enable(struct pxad_phy *phy, bool misaligned)
511 {
512 	u32 reg, dalgn;
513 
514 	if (!phy->vchan)
515 		return;
516 
517 	dev_dbg(&phy->vchan->vc.chan.dev->device,
518 		"%s(); phy=%p(%d) misaligned=%d\n", __func__,
519 		phy, phy->idx, misaligned);
520 
521 	if (phy->vchan->drcmr <= DRCMR_CHLNUM) {
522 		reg = pxad_drcmr(phy->vchan->drcmr);
523 		writel_relaxed(DRCMR_MAPVLD | phy->idx, phy->base + reg);
524 	}
525 
526 	dalgn = phy_readl_relaxed(phy, DALGN);
527 	if (misaligned)
528 		dalgn |= BIT(phy->idx);
529 	else
530 		dalgn &= ~BIT(phy->idx);
531 	phy_writel_relaxed(phy, dalgn, DALGN);
532 
533 	phy_writel(phy, PXA_DCSR_STOPIRQEN | PXA_DCSR_ENDINTR |
534 		   PXA_DCSR_BUSERR | PXA_DCSR_RUN, DCSR);
535 }
536 
537 static void phy_disable(struct pxad_phy *phy)
538 {
539 	u32 dcsr;
540 
541 	if (!phy)
542 		return;
543 
544 	dcsr = phy_readl_relaxed(phy, DCSR);
545 	dev_dbg(&phy->vchan->vc.chan.dev->device,
546 		"%s(): phy=%p(%d)\n", __func__, phy, phy->idx);
547 	phy_writel(phy, dcsr & ~PXA_DCSR_RUN & ~PXA_DCSR_STOPIRQEN, DCSR);
548 }
549 
550 static void pxad_launch_chan(struct pxad_chan *chan,
551 				 struct pxad_desc_sw *desc)
552 {
553 	dev_dbg(&chan->vc.chan.dev->device,
554 		"%s(): desc=%p\n", __func__, desc);
555 	if (!chan->phy) {
556 		chan->phy = lookup_phy(chan);
557 		if (!chan->phy) {
558 			dev_dbg(&chan->vc.chan.dev->device,
559 				"%s(): no free dma channel\n", __func__);
560 			return;
561 		}
562 	}
563 
564 	/*
565 	 * Program the descriptor's address into the DMA controller,
566 	 * then start the DMA transaction
567 	 */
568 	phy_writel(chan->phy, desc->first, DDADR);
569 	phy_enable(chan->phy, chan->misaligned);
570 }
571 
572 static void set_updater_desc(struct pxad_desc_sw *sw_desc,
573 			     unsigned long flags)
574 {
575 	struct pxad_desc_hw *updater =
576 		sw_desc->hw_desc[sw_desc->nb_desc - 1];
577 	dma_addr_t dma = sw_desc->hw_desc[sw_desc->nb_desc - 2]->ddadr;
578 
579 	updater->ddadr = DDADR_STOP;
580 	updater->dsadr = dma;
581 	updater->dtadr = dma + 8;
582 	updater->dcmd = PXA_DCMD_WIDTH4 | PXA_DCMD_BURST32 |
583 		(PXA_DCMD_LENGTH & sizeof(u32));
584 	if (flags & DMA_PREP_INTERRUPT)
585 		updater->dcmd |= PXA_DCMD_ENDIRQEN;
586 }
587 
588 static bool is_desc_completed(struct virt_dma_desc *vd)
589 {
590 	struct pxad_desc_sw *sw_desc = to_pxad_sw_desc(vd);
591 	struct pxad_desc_hw *updater =
592 		sw_desc->hw_desc[sw_desc->nb_desc - 1];
593 
594 	return updater->dtadr != (updater->dsadr + 8);
595 }
596 
597 static void pxad_desc_chain(struct virt_dma_desc *vd1,
598 				struct virt_dma_desc *vd2)
599 {
600 	struct pxad_desc_sw *desc1 = to_pxad_sw_desc(vd1);
601 	struct pxad_desc_sw *desc2 = to_pxad_sw_desc(vd2);
602 	dma_addr_t dma_to_chain;
603 
604 	dma_to_chain = desc2->first;
605 	desc1->hw_desc[desc1->nb_desc - 1]->ddadr = dma_to_chain;
606 }
607 
608 static bool pxad_try_hotchain(struct virt_dma_chan *vc,
609 				  struct virt_dma_desc *vd)
610 {
611 	struct virt_dma_desc *vd_last_issued = NULL;
612 	struct pxad_chan *chan = to_pxad_chan(&vc->chan);
613 
614 	/*
615 	 * Attempt to hot chain the tx if the phy is still running. This is
616 	 * considered successful only if either the channel is still running
617 	 * after the chaining, or if the chained transfer is completed after
618 	 * having been hot chained.
619 	 * A change of alignment is not allowed, and forbids hotchaining.
620 	 */
621 	if (is_chan_running(chan)) {
622 		BUG_ON(list_empty(&vc->desc_issued));
623 
624 		if (!is_running_chan_misaligned(chan) &&
625 		    to_pxad_sw_desc(vd)->misaligned)
626 			return false;
627 
628 		vd_last_issued = list_entry(vc->desc_issued.prev,
629 					    struct virt_dma_desc, node);
630 		pxad_desc_chain(vd_last_issued, vd);
631 		if (is_chan_running(chan) || is_desc_completed(vd_last_issued))
632 			return true;
633 	}
634 
635 	return false;
636 }
637 
638 static unsigned int clear_chan_irq(struct pxad_phy *phy)
639 {
640 	u32 dcsr;
641 	u32 dint = readl(phy->base + DINT);
642 
643 	if (!(dint & BIT(phy->idx)))
644 		return PXA_DCSR_RUN;
645 
646 	/* clear irq */
647 	dcsr = phy_readl_relaxed(phy, DCSR);
648 	phy_writel(phy, dcsr, DCSR);
649 	if ((dcsr & PXA_DCSR_BUSERR) && (phy->vchan))
650 		dev_warn(&phy->vchan->vc.chan.dev->device,
651 			 "%s(chan=%p): PXA_DCSR_BUSERR\n",
652 			 __func__, &phy->vchan);
653 
654 	return dcsr & ~PXA_DCSR_RUN;
655 }
656 
657 static irqreturn_t pxad_chan_handler(int irq, void *dev_id)
658 {
659 	struct pxad_phy *phy = dev_id;
660 	struct pxad_chan *chan = phy->vchan;
661 	struct virt_dma_desc *vd, *tmp;
662 	unsigned int dcsr;
663 	unsigned long flags;
664 
665 	BUG_ON(!chan);
666 
667 	dcsr = clear_chan_irq(phy);
668 	if (dcsr & PXA_DCSR_RUN)
669 		return IRQ_NONE;
670 
671 	spin_lock_irqsave(&chan->vc.lock, flags);
672 	list_for_each_entry_safe(vd, tmp, &chan->vc.desc_issued, node) {
673 		dev_dbg(&chan->vc.chan.dev->device,
674 			"%s(): checking txd %p[%x]: completed=%d\n",
675 			__func__, vd, vd->tx.cookie, is_desc_completed(vd));
676 		if (is_desc_completed(vd)) {
677 			list_del(&vd->node);
678 			vchan_cookie_complete(vd);
679 		} else {
680 			break;
681 		}
682 	}
683 
684 	if (dcsr & PXA_DCSR_STOPSTATE) {
685 		dev_dbg(&chan->vc.chan.dev->device,
686 		"%s(): channel stopped, submitted_empty=%d issued_empty=%d",
687 			__func__,
688 			list_empty(&chan->vc.desc_submitted),
689 			list_empty(&chan->vc.desc_issued));
690 		phy_writel_relaxed(phy, dcsr & ~PXA_DCSR_STOPIRQEN, DCSR);
691 
692 		if (list_empty(&chan->vc.desc_issued)) {
693 			chan->misaligned =
694 				!list_empty(&chan->vc.desc_submitted);
695 		} else {
696 			vd = list_first_entry(&chan->vc.desc_issued,
697 					      struct virt_dma_desc, node);
698 			pxad_launch_chan(chan, to_pxad_sw_desc(vd));
699 		}
700 	}
701 	spin_unlock_irqrestore(&chan->vc.lock, flags);
702 
703 	return IRQ_HANDLED;
704 }
705 
706 static irqreturn_t pxad_int_handler(int irq, void *dev_id)
707 {
708 	struct pxad_device *pdev = dev_id;
709 	struct pxad_phy *phy;
710 	u32 dint = readl(pdev->base + DINT);
711 	int i, ret = IRQ_NONE;
712 
713 	while (dint) {
714 		i = __ffs(dint);
715 		dint &= (dint - 1);
716 		phy = &pdev->phys[i];
717 		if ((i < 32) && (legacy_reserved & BIT(i)))
718 			continue;
719 		if (pxad_chan_handler(irq, phy) == IRQ_HANDLED)
720 			ret = IRQ_HANDLED;
721 	}
722 
723 	return ret;
724 }
725 
726 static int pxad_alloc_chan_resources(struct dma_chan *dchan)
727 {
728 	struct pxad_chan *chan = to_pxad_chan(dchan);
729 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
730 
731 	if (chan->desc_pool)
732 		return 1;
733 
734 	chan->desc_pool = dma_pool_create(dma_chan_name(dchan),
735 					  pdev->slave.dev,
736 					  sizeof(struct pxad_desc_hw),
737 					  __alignof__(struct pxad_desc_hw),
738 					  0);
739 	if (!chan->desc_pool) {
740 		dev_err(&chan->vc.chan.dev->device,
741 			"%s(): unable to allocate descriptor pool\n",
742 			__func__);
743 		return -ENOMEM;
744 	}
745 
746 	return 1;
747 }
748 
749 static void pxad_free_chan_resources(struct dma_chan *dchan)
750 {
751 	struct pxad_chan *chan = to_pxad_chan(dchan);
752 
753 	vchan_free_chan_resources(&chan->vc);
754 	dma_pool_destroy(chan->desc_pool);
755 	chan->desc_pool = NULL;
756 
757 }
758 
759 static void pxad_free_desc(struct virt_dma_desc *vd)
760 {
761 	int i;
762 	dma_addr_t dma;
763 	struct pxad_desc_sw *sw_desc = to_pxad_sw_desc(vd);
764 
765 	BUG_ON(sw_desc->nb_desc == 0);
766 	for (i = sw_desc->nb_desc - 1; i >= 0; i--) {
767 		if (i > 0)
768 			dma = sw_desc->hw_desc[i - 1]->ddadr;
769 		else
770 			dma = sw_desc->first;
771 		dma_pool_free(sw_desc->desc_pool,
772 			      sw_desc->hw_desc[i], dma);
773 	}
774 	sw_desc->nb_desc = 0;
775 	kfree(sw_desc);
776 }
777 
778 static struct pxad_desc_sw *
779 pxad_alloc_desc(struct pxad_chan *chan, unsigned int nb_hw_desc)
780 {
781 	struct pxad_desc_sw *sw_desc;
782 	dma_addr_t dma;
783 	int i;
784 
785 	sw_desc = kzalloc(sizeof(*sw_desc) +
786 			  nb_hw_desc * sizeof(struct pxad_desc_hw *),
787 			  GFP_NOWAIT);
788 	if (!sw_desc)
789 		return NULL;
790 	sw_desc->desc_pool = chan->desc_pool;
791 
792 	for (i = 0; i < nb_hw_desc; i++) {
793 		sw_desc->hw_desc[i] = dma_pool_alloc(sw_desc->desc_pool,
794 						     GFP_NOWAIT, &dma);
795 		if (!sw_desc->hw_desc[i]) {
796 			dev_err(&chan->vc.chan.dev->device,
797 				"%s(): Couldn't allocate the %dth hw_desc from dma_pool %p\n",
798 				__func__, i, sw_desc->desc_pool);
799 			goto err;
800 		}
801 
802 		if (i == 0)
803 			sw_desc->first = dma;
804 		else
805 			sw_desc->hw_desc[i - 1]->ddadr = dma;
806 		sw_desc->nb_desc++;
807 	}
808 
809 	return sw_desc;
810 err:
811 	pxad_free_desc(&sw_desc->vd);
812 	return NULL;
813 }
814 
815 static dma_cookie_t pxad_tx_submit(struct dma_async_tx_descriptor *tx)
816 {
817 	struct virt_dma_chan *vc = to_virt_chan(tx->chan);
818 	struct pxad_chan *chan = to_pxad_chan(&vc->chan);
819 	struct virt_dma_desc *vd_chained = NULL,
820 		*vd = container_of(tx, struct virt_dma_desc, tx);
821 	dma_cookie_t cookie;
822 	unsigned long flags;
823 
824 	set_updater_desc(to_pxad_sw_desc(vd), tx->flags);
825 
826 	spin_lock_irqsave(&vc->lock, flags);
827 	cookie = dma_cookie_assign(tx);
828 
829 	if (list_empty(&vc->desc_submitted) && pxad_try_hotchain(vc, vd)) {
830 		list_move_tail(&vd->node, &vc->desc_issued);
831 		dev_dbg(&chan->vc.chan.dev->device,
832 			"%s(): txd %p[%x]: submitted (hot linked)\n",
833 			__func__, vd, cookie);
834 		goto out;
835 	}
836 
837 	/*
838 	 * Fallback to placing the tx in the submitted queue
839 	 */
840 	if (!list_empty(&vc->desc_submitted)) {
841 		vd_chained = list_entry(vc->desc_submitted.prev,
842 					struct virt_dma_desc, node);
843 		/*
844 		 * Only chain the descriptors if no new misalignment is
845 		 * introduced. If a new misalignment is chained, let the channel
846 		 * stop, and be relaunched in misalign mode from the irq
847 		 * handler.
848 		 */
849 		if (chan->misaligned || !to_pxad_sw_desc(vd)->misaligned)
850 			pxad_desc_chain(vd_chained, vd);
851 		else
852 			vd_chained = NULL;
853 	}
854 	dev_dbg(&chan->vc.chan.dev->device,
855 		"%s(): txd %p[%x]: submitted (%s linked)\n",
856 		__func__, vd, cookie, vd_chained ? "cold" : "not");
857 	list_move_tail(&vd->node, &vc->desc_submitted);
858 	chan->misaligned |= to_pxad_sw_desc(vd)->misaligned;
859 
860 out:
861 	spin_unlock_irqrestore(&vc->lock, flags);
862 	return cookie;
863 }
864 
865 static void pxad_issue_pending(struct dma_chan *dchan)
866 {
867 	struct pxad_chan *chan = to_pxad_chan(dchan);
868 	struct virt_dma_desc *vd_first;
869 	unsigned long flags;
870 
871 	spin_lock_irqsave(&chan->vc.lock, flags);
872 	if (list_empty(&chan->vc.desc_submitted))
873 		goto out;
874 
875 	vd_first = list_first_entry(&chan->vc.desc_submitted,
876 				    struct virt_dma_desc, node);
877 	dev_dbg(&chan->vc.chan.dev->device,
878 		"%s(): txd %p[%x]", __func__, vd_first, vd_first->tx.cookie);
879 
880 	vchan_issue_pending(&chan->vc);
881 	if (!pxad_try_hotchain(&chan->vc, vd_first))
882 		pxad_launch_chan(chan, to_pxad_sw_desc(vd_first));
883 out:
884 	spin_unlock_irqrestore(&chan->vc.lock, flags);
885 }
886 
887 static inline struct dma_async_tx_descriptor *
888 pxad_tx_prep(struct virt_dma_chan *vc, struct virt_dma_desc *vd,
889 		 unsigned long tx_flags)
890 {
891 	struct dma_async_tx_descriptor *tx;
892 	struct pxad_chan *chan = container_of(vc, struct pxad_chan, vc);
893 
894 	INIT_LIST_HEAD(&vd->node);
895 	tx = vchan_tx_prep(vc, vd, tx_flags);
896 	tx->tx_submit = pxad_tx_submit;
897 	dev_dbg(&chan->vc.chan.dev->device,
898 		"%s(): vc=%p txd=%p[%x] flags=0x%lx\n", __func__,
899 		vc, vd, vd->tx.cookie,
900 		tx_flags);
901 
902 	return tx;
903 }
904 
905 static void pxad_get_config(struct pxad_chan *chan,
906 			    enum dma_transfer_direction dir,
907 			    u32 *dcmd, u32 *dev_src, u32 *dev_dst)
908 {
909 	u32 maxburst = 0, dev_addr = 0;
910 	enum dma_slave_buswidth width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
911 
912 	*dcmd = 0;
913 	if (dir == DMA_DEV_TO_MEM) {
914 		maxburst = chan->cfg.src_maxburst;
915 		width = chan->cfg.src_addr_width;
916 		dev_addr = chan->cfg.src_addr;
917 		*dev_src = dev_addr;
918 		*dcmd |= PXA_DCMD_INCTRGADDR;
919 		if (chan->drcmr <= DRCMR_CHLNUM)
920 			*dcmd |= PXA_DCMD_FLOWSRC;
921 	}
922 	if (dir == DMA_MEM_TO_DEV) {
923 		maxburst = chan->cfg.dst_maxburst;
924 		width = chan->cfg.dst_addr_width;
925 		dev_addr = chan->cfg.dst_addr;
926 		*dev_dst = dev_addr;
927 		*dcmd |= PXA_DCMD_INCSRCADDR;
928 		if (chan->drcmr <= DRCMR_CHLNUM)
929 			*dcmd |= PXA_DCMD_FLOWTRG;
930 	}
931 	if (dir == DMA_MEM_TO_MEM)
932 		*dcmd |= PXA_DCMD_BURST32 | PXA_DCMD_INCTRGADDR |
933 			PXA_DCMD_INCSRCADDR;
934 
935 	dev_dbg(&chan->vc.chan.dev->device,
936 		"%s(): dev_addr=0x%x maxburst=%d width=%d  dir=%d\n",
937 		__func__, dev_addr, maxburst, width, dir);
938 
939 	if (width == DMA_SLAVE_BUSWIDTH_1_BYTE)
940 		*dcmd |= PXA_DCMD_WIDTH1;
941 	else if (width == DMA_SLAVE_BUSWIDTH_2_BYTES)
942 		*dcmd |= PXA_DCMD_WIDTH2;
943 	else if (width == DMA_SLAVE_BUSWIDTH_4_BYTES)
944 		*dcmd |= PXA_DCMD_WIDTH4;
945 
946 	if (maxburst == 8)
947 		*dcmd |= PXA_DCMD_BURST8;
948 	else if (maxburst == 16)
949 		*dcmd |= PXA_DCMD_BURST16;
950 	else if (maxburst == 32)
951 		*dcmd |= PXA_DCMD_BURST32;
952 
953 	/* FIXME: drivers should be ported over to use the filter
954 	 * function. Once that's done, the following two lines can
955 	 * be removed.
956 	 */
957 	if (chan->cfg.slave_id)
958 		chan->drcmr = chan->cfg.slave_id;
959 }
960 
961 static struct dma_async_tx_descriptor *
962 pxad_prep_memcpy(struct dma_chan *dchan,
963 		 dma_addr_t dma_dst, dma_addr_t dma_src,
964 		 size_t len, unsigned long flags)
965 {
966 	struct pxad_chan *chan = to_pxad_chan(dchan);
967 	struct pxad_desc_sw *sw_desc;
968 	struct pxad_desc_hw *hw_desc;
969 	u32 dcmd;
970 	unsigned int i, nb_desc = 0;
971 	size_t copy;
972 
973 	if (!dchan || !len)
974 		return NULL;
975 
976 	dev_dbg(&chan->vc.chan.dev->device,
977 		"%s(): dma_dst=0x%lx dma_src=0x%lx len=%zu flags=%lx\n",
978 		__func__, (unsigned long)dma_dst, (unsigned long)dma_src,
979 		len, flags);
980 	pxad_get_config(chan, DMA_MEM_TO_MEM, &dcmd, NULL, NULL);
981 
982 	nb_desc = DIV_ROUND_UP(len, PDMA_MAX_DESC_BYTES);
983 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
984 	if (!sw_desc)
985 		return NULL;
986 	sw_desc->len = len;
987 
988 	if (!IS_ALIGNED(dma_src, 1 << PDMA_ALIGNMENT) ||
989 	    !IS_ALIGNED(dma_dst, 1 << PDMA_ALIGNMENT))
990 		sw_desc->misaligned = true;
991 
992 	i = 0;
993 	do {
994 		hw_desc = sw_desc->hw_desc[i++];
995 		copy = min_t(size_t, len, PDMA_MAX_DESC_BYTES);
996 		hw_desc->dcmd = dcmd | (PXA_DCMD_LENGTH & copy);
997 		hw_desc->dsadr = dma_src;
998 		hw_desc->dtadr = dma_dst;
999 		len -= copy;
1000 		dma_src += copy;
1001 		dma_dst += copy;
1002 	} while (len);
1003 	set_updater_desc(sw_desc, flags);
1004 
1005 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
1006 }
1007 
1008 static struct dma_async_tx_descriptor *
1009 pxad_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
1010 		   unsigned int sg_len, enum dma_transfer_direction dir,
1011 		   unsigned long flags, void *context)
1012 {
1013 	struct pxad_chan *chan = to_pxad_chan(dchan);
1014 	struct pxad_desc_sw *sw_desc;
1015 	size_t len, avail;
1016 	struct scatterlist *sg;
1017 	dma_addr_t dma;
1018 	u32 dcmd, dsadr = 0, dtadr = 0;
1019 	unsigned int nb_desc = 0, i, j = 0;
1020 
1021 	if ((sgl == NULL) || (sg_len == 0))
1022 		return NULL;
1023 
1024 	pxad_get_config(chan, dir, &dcmd, &dsadr, &dtadr);
1025 	dev_dbg(&chan->vc.chan.dev->device,
1026 		"%s(): dir=%d flags=%lx\n", __func__, dir, flags);
1027 
1028 	for_each_sg(sgl, sg, sg_len, i)
1029 		nb_desc += DIV_ROUND_UP(sg_dma_len(sg), PDMA_MAX_DESC_BYTES);
1030 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
1031 	if (!sw_desc)
1032 		return NULL;
1033 
1034 	for_each_sg(sgl, sg, sg_len, i) {
1035 		dma = sg_dma_address(sg);
1036 		avail = sg_dma_len(sg);
1037 		sw_desc->len += avail;
1038 
1039 		do {
1040 			len = min_t(size_t, avail, PDMA_MAX_DESC_BYTES);
1041 			if (dma & 0x7)
1042 				sw_desc->misaligned = true;
1043 
1044 			sw_desc->hw_desc[j]->dcmd =
1045 				dcmd | (PXA_DCMD_LENGTH & len);
1046 			sw_desc->hw_desc[j]->dsadr = dsadr ? dsadr : dma;
1047 			sw_desc->hw_desc[j++]->dtadr = dtadr ? dtadr : dma;
1048 
1049 			dma += len;
1050 			avail -= len;
1051 		} while (avail);
1052 	}
1053 	set_updater_desc(sw_desc, flags);
1054 
1055 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
1056 }
1057 
1058 static struct dma_async_tx_descriptor *
1059 pxad_prep_dma_cyclic(struct dma_chan *dchan,
1060 		     dma_addr_t buf_addr, size_t len, size_t period_len,
1061 		     enum dma_transfer_direction dir, unsigned long flags)
1062 {
1063 	struct pxad_chan *chan = to_pxad_chan(dchan);
1064 	struct pxad_desc_sw *sw_desc;
1065 	struct pxad_desc_hw **phw_desc;
1066 	dma_addr_t dma;
1067 	u32 dcmd, dsadr = 0, dtadr = 0;
1068 	unsigned int nb_desc = 0;
1069 
1070 	if (!dchan || !len || !period_len)
1071 		return NULL;
1072 	if ((dir != DMA_DEV_TO_MEM) && (dir != DMA_MEM_TO_DEV)) {
1073 		dev_err(&chan->vc.chan.dev->device,
1074 			"Unsupported direction for cyclic DMA\n");
1075 		return NULL;
1076 	}
1077 	/* the buffer length must be a multiple of period_len */
1078 	if (len % period_len != 0 || period_len > PDMA_MAX_DESC_BYTES ||
1079 	    !IS_ALIGNED(period_len, 1 << PDMA_ALIGNMENT))
1080 		return NULL;
1081 
1082 	pxad_get_config(chan, dir, &dcmd, &dsadr, &dtadr);
1083 	dcmd |= PXA_DCMD_ENDIRQEN | (PXA_DCMD_LENGTH | period_len);
1084 	dev_dbg(&chan->vc.chan.dev->device,
1085 		"%s(): buf_addr=0x%lx len=%zu period=%zu dir=%d flags=%lx\n",
1086 		__func__, (unsigned long)buf_addr, len, period_len, dir, flags);
1087 
1088 	nb_desc = DIV_ROUND_UP(period_len, PDMA_MAX_DESC_BYTES);
1089 	nb_desc *= DIV_ROUND_UP(len, period_len);
1090 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
1091 	if (!sw_desc)
1092 		return NULL;
1093 	sw_desc->cyclic = true;
1094 	sw_desc->len = len;
1095 
1096 	phw_desc = sw_desc->hw_desc;
1097 	dma = buf_addr;
1098 	do {
1099 		phw_desc[0]->dsadr = dsadr ? dsadr : dma;
1100 		phw_desc[0]->dtadr = dtadr ? dtadr : dma;
1101 		phw_desc[0]->dcmd = dcmd;
1102 		phw_desc++;
1103 		dma += period_len;
1104 		len -= period_len;
1105 	} while (len);
1106 	set_updater_desc(sw_desc, flags);
1107 
1108 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
1109 }
1110 
1111 static int pxad_config(struct dma_chan *dchan,
1112 		       struct dma_slave_config *cfg)
1113 {
1114 	struct pxad_chan *chan = to_pxad_chan(dchan);
1115 
1116 	if (!dchan)
1117 		return -EINVAL;
1118 
1119 	chan->cfg = *cfg;
1120 	return 0;
1121 }
1122 
1123 static int pxad_terminate_all(struct dma_chan *dchan)
1124 {
1125 	struct pxad_chan *chan = to_pxad_chan(dchan);
1126 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
1127 	struct virt_dma_desc *vd = NULL;
1128 	unsigned long flags;
1129 	struct pxad_phy *phy;
1130 	LIST_HEAD(head);
1131 
1132 	dev_dbg(&chan->vc.chan.dev->device,
1133 		"%s(): vchan %p: terminate all\n", __func__, &chan->vc);
1134 
1135 	spin_lock_irqsave(&chan->vc.lock, flags);
1136 	vchan_get_all_descriptors(&chan->vc, &head);
1137 
1138 	list_for_each_entry(vd, &head, node) {
1139 		dev_dbg(&chan->vc.chan.dev->device,
1140 			"%s(): cancelling txd %p[%x] (completed=%d)", __func__,
1141 			vd, vd->tx.cookie, is_desc_completed(vd));
1142 	}
1143 
1144 	phy = chan->phy;
1145 	if (phy) {
1146 		phy_disable(chan->phy);
1147 		pxad_free_phy(chan);
1148 		chan->phy = NULL;
1149 		spin_lock(&pdev->phy_lock);
1150 		phy->vchan = NULL;
1151 		spin_unlock(&pdev->phy_lock);
1152 	}
1153 	spin_unlock_irqrestore(&chan->vc.lock, flags);
1154 	vchan_dma_desc_free_list(&chan->vc, &head);
1155 
1156 	return 0;
1157 }
1158 
1159 static unsigned int pxad_residue(struct pxad_chan *chan,
1160 				 dma_cookie_t cookie)
1161 {
1162 	struct virt_dma_desc *vd = NULL;
1163 	struct pxad_desc_sw *sw_desc = NULL;
1164 	struct pxad_desc_hw *hw_desc = NULL;
1165 	u32 curr, start, len, end, residue = 0;
1166 	unsigned long flags;
1167 	bool passed = false;
1168 	int i;
1169 
1170 	/*
1171 	 * If the channel does not have a phy pointer anymore, it has already
1172 	 * been completed. Therefore, its residue is 0.
1173 	 */
1174 	if (!chan->phy)
1175 		return 0;
1176 
1177 	spin_lock_irqsave(&chan->vc.lock, flags);
1178 
1179 	vd = vchan_find_desc(&chan->vc, cookie);
1180 	if (!vd)
1181 		goto out;
1182 
1183 	sw_desc = to_pxad_sw_desc(vd);
1184 	if (sw_desc->hw_desc[0]->dcmd & PXA_DCMD_INCSRCADDR)
1185 		curr = phy_readl_relaxed(chan->phy, DSADR);
1186 	else
1187 		curr = phy_readl_relaxed(chan->phy, DTADR);
1188 
1189 	/*
1190 	 * curr has to be actually read before checking descriptor
1191 	 * completion, so that a curr inside a status updater
1192 	 * descriptor implies the following test returns true, and
1193 	 * preventing reordering of curr load and the test.
1194 	 */
1195 	rmb();
1196 	if (is_desc_completed(vd))
1197 		goto out;
1198 
1199 	for (i = 0; i < sw_desc->nb_desc - 1; i++) {
1200 		hw_desc = sw_desc->hw_desc[i];
1201 		if (sw_desc->hw_desc[0]->dcmd & PXA_DCMD_INCSRCADDR)
1202 			start = hw_desc->dsadr;
1203 		else
1204 			start = hw_desc->dtadr;
1205 		len = hw_desc->dcmd & PXA_DCMD_LENGTH;
1206 		end = start + len;
1207 
1208 		/*
1209 		 * 'passed' will be latched once we found the descriptor
1210 		 * which lies inside the boundaries of the curr
1211 		 * pointer. All descriptors that occur in the list
1212 		 * _after_ we found that partially handled descriptor
1213 		 * are still to be processed and are hence added to the
1214 		 * residual bytes counter.
1215 		 */
1216 
1217 		if (passed) {
1218 			residue += len;
1219 		} else if (curr >= start && curr <= end) {
1220 			residue += end - curr;
1221 			passed = true;
1222 		}
1223 	}
1224 	if (!passed)
1225 		residue = sw_desc->len;
1226 
1227 out:
1228 	spin_unlock_irqrestore(&chan->vc.lock, flags);
1229 	dev_dbg(&chan->vc.chan.dev->device,
1230 		"%s(): txd %p[%x] sw_desc=%p: %d\n",
1231 		__func__, vd, cookie, sw_desc, residue);
1232 	return residue;
1233 }
1234 
1235 static enum dma_status pxad_tx_status(struct dma_chan *dchan,
1236 				      dma_cookie_t cookie,
1237 				      struct dma_tx_state *txstate)
1238 {
1239 	struct pxad_chan *chan = to_pxad_chan(dchan);
1240 	enum dma_status ret;
1241 
1242 	ret = dma_cookie_status(dchan, cookie, txstate);
1243 	if (likely(txstate && (ret != DMA_ERROR)))
1244 		dma_set_residue(txstate, pxad_residue(chan, cookie));
1245 
1246 	return ret;
1247 }
1248 
1249 static void pxad_free_channels(struct dma_device *dmadev)
1250 {
1251 	struct pxad_chan *c, *cn;
1252 
1253 	list_for_each_entry_safe(c, cn, &dmadev->channels,
1254 				 vc.chan.device_node) {
1255 		list_del(&c->vc.chan.device_node);
1256 		tasklet_kill(&c->vc.task);
1257 	}
1258 }
1259 
1260 static int pxad_remove(struct platform_device *op)
1261 {
1262 	struct pxad_device *pdev = platform_get_drvdata(op);
1263 
1264 	pxad_cleanup_debugfs(pdev);
1265 	pxad_free_channels(&pdev->slave);
1266 	dma_async_device_unregister(&pdev->slave);
1267 	return 0;
1268 }
1269 
1270 static int pxad_init_phys(struct platform_device *op,
1271 			  struct pxad_device *pdev,
1272 			  unsigned int nb_phy_chans)
1273 {
1274 	int irq0, irq, nr_irq = 0, i, ret;
1275 	struct pxad_phy *phy;
1276 
1277 	irq0 = platform_get_irq(op, 0);
1278 	if (irq0 < 0)
1279 		return irq0;
1280 
1281 	pdev->phys = devm_kcalloc(&op->dev, nb_phy_chans,
1282 				  sizeof(pdev->phys[0]), GFP_KERNEL);
1283 	if (!pdev->phys)
1284 		return -ENOMEM;
1285 
1286 	for (i = 0; i < nb_phy_chans; i++)
1287 		if (platform_get_irq(op, i) > 0)
1288 			nr_irq++;
1289 
1290 	for (i = 0; i < nb_phy_chans; i++) {
1291 		phy = &pdev->phys[i];
1292 		phy->base = pdev->base;
1293 		phy->idx = i;
1294 		irq = platform_get_irq(op, i);
1295 		if ((nr_irq > 1) && (irq > 0))
1296 			ret = devm_request_irq(&op->dev, irq,
1297 					       pxad_chan_handler,
1298 					       IRQF_SHARED, "pxa-dma", phy);
1299 		if ((nr_irq == 1) && (i == 0))
1300 			ret = devm_request_irq(&op->dev, irq0,
1301 					       pxad_int_handler,
1302 					       IRQF_SHARED, "pxa-dma", pdev);
1303 		if (ret) {
1304 			dev_err(pdev->slave.dev,
1305 				"%s(): can't request irq %d:%d\n", __func__,
1306 				irq, ret);
1307 			return ret;
1308 		}
1309 	}
1310 
1311 	return 0;
1312 }
1313 
1314 static const struct of_device_id const pxad_dt_ids[] = {
1315 	{ .compatible = "marvell,pdma-1.0", },
1316 	{}
1317 };
1318 MODULE_DEVICE_TABLE(of, pxad_dt_ids);
1319 
1320 static struct dma_chan *pxad_dma_xlate(struct of_phandle_args *dma_spec,
1321 					   struct of_dma *ofdma)
1322 {
1323 	struct pxad_device *d = ofdma->of_dma_data;
1324 	struct dma_chan *chan;
1325 
1326 	chan = dma_get_any_slave_channel(&d->slave);
1327 	if (!chan)
1328 		return NULL;
1329 
1330 	to_pxad_chan(chan)->drcmr = dma_spec->args[0];
1331 	to_pxad_chan(chan)->prio = dma_spec->args[1];
1332 
1333 	return chan;
1334 }
1335 
1336 static int pxad_init_dmadev(struct platform_device *op,
1337 			    struct pxad_device *pdev,
1338 			    unsigned int nr_phy_chans)
1339 {
1340 	int ret;
1341 	unsigned int i;
1342 	struct pxad_chan *c;
1343 
1344 	pdev->nr_chans = nr_phy_chans;
1345 	INIT_LIST_HEAD(&pdev->slave.channels);
1346 	pdev->slave.device_alloc_chan_resources = pxad_alloc_chan_resources;
1347 	pdev->slave.device_free_chan_resources = pxad_free_chan_resources;
1348 	pdev->slave.device_tx_status = pxad_tx_status;
1349 	pdev->slave.device_issue_pending = pxad_issue_pending;
1350 	pdev->slave.device_config = pxad_config;
1351 	pdev->slave.device_terminate_all = pxad_terminate_all;
1352 
1353 	if (op->dev.coherent_dma_mask)
1354 		dma_set_mask(&op->dev, op->dev.coherent_dma_mask);
1355 	else
1356 		dma_set_mask(&op->dev, DMA_BIT_MASK(32));
1357 
1358 	ret = pxad_init_phys(op, pdev, nr_phy_chans);
1359 	if (ret)
1360 		return ret;
1361 
1362 	for (i = 0; i < nr_phy_chans; i++) {
1363 		c = devm_kzalloc(&op->dev, sizeof(*c), GFP_KERNEL);
1364 		if (!c)
1365 			return -ENOMEM;
1366 		c->vc.desc_free = pxad_free_desc;
1367 		vchan_init(&c->vc, &pdev->slave);
1368 	}
1369 
1370 	return dma_async_device_register(&pdev->slave);
1371 }
1372 
1373 static int pxad_probe(struct platform_device *op)
1374 {
1375 	struct pxad_device *pdev;
1376 	const struct of_device_id *of_id;
1377 	struct mmp_dma_platdata *pdata = dev_get_platdata(&op->dev);
1378 	struct resource *iores;
1379 	int ret, dma_channels = 0;
1380 	const enum dma_slave_buswidth widths =
1381 		DMA_SLAVE_BUSWIDTH_1_BYTE   | DMA_SLAVE_BUSWIDTH_2_BYTES |
1382 		DMA_SLAVE_BUSWIDTH_4_BYTES;
1383 
1384 	pdev = devm_kzalloc(&op->dev, sizeof(*pdev), GFP_KERNEL);
1385 	if (!pdev)
1386 		return -ENOMEM;
1387 
1388 	spin_lock_init(&pdev->phy_lock);
1389 
1390 	iores = platform_get_resource(op, IORESOURCE_MEM, 0);
1391 	pdev->base = devm_ioremap_resource(&op->dev, iores);
1392 	if (IS_ERR(pdev->base))
1393 		return PTR_ERR(pdev->base);
1394 
1395 	of_id = of_match_device(pxad_dt_ids, &op->dev);
1396 	if (of_id)
1397 		of_property_read_u32(op->dev.of_node, "#dma-channels",
1398 				     &dma_channels);
1399 	else if (pdata && pdata->dma_channels)
1400 		dma_channels = pdata->dma_channels;
1401 	else
1402 		dma_channels = 32;	/* default 32 channel */
1403 
1404 	dma_cap_set(DMA_SLAVE, pdev->slave.cap_mask);
1405 	dma_cap_set(DMA_MEMCPY, pdev->slave.cap_mask);
1406 	dma_cap_set(DMA_CYCLIC, pdev->slave.cap_mask);
1407 	dma_cap_set(DMA_PRIVATE, pdev->slave.cap_mask);
1408 	pdev->slave.device_prep_dma_memcpy = pxad_prep_memcpy;
1409 	pdev->slave.device_prep_slave_sg = pxad_prep_slave_sg;
1410 	pdev->slave.device_prep_dma_cyclic = pxad_prep_dma_cyclic;
1411 
1412 	pdev->slave.copy_align = PDMA_ALIGNMENT;
1413 	pdev->slave.src_addr_widths = widths;
1414 	pdev->slave.dst_addr_widths = widths;
1415 	pdev->slave.directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
1416 	pdev->slave.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
1417 
1418 	pdev->slave.dev = &op->dev;
1419 	ret = pxad_init_dmadev(op, pdev, dma_channels);
1420 	if (ret) {
1421 		dev_err(pdev->slave.dev, "unable to register\n");
1422 		return ret;
1423 	}
1424 
1425 	if (op->dev.of_node) {
1426 		/* Device-tree DMA controller registration */
1427 		ret = of_dma_controller_register(op->dev.of_node,
1428 						 pxad_dma_xlate, pdev);
1429 		if (ret < 0) {
1430 			dev_err(pdev->slave.dev,
1431 				"of_dma_controller_register failed\n");
1432 			return ret;
1433 		}
1434 	}
1435 
1436 	platform_set_drvdata(op, pdev);
1437 	pxad_init_debugfs(pdev);
1438 	dev_info(pdev->slave.dev, "initialized %d channels\n", dma_channels);
1439 	return 0;
1440 }
1441 
1442 static const struct platform_device_id pxad_id_table[] = {
1443 	{ "pxa-dma", },
1444 	{ },
1445 };
1446 
1447 static struct platform_driver pxad_driver = {
1448 	.driver		= {
1449 		.name	= "pxa-dma",
1450 		.of_match_table = pxad_dt_ids,
1451 	},
1452 	.id_table	= pxad_id_table,
1453 	.probe		= pxad_probe,
1454 	.remove		= pxad_remove,
1455 };
1456 
1457 bool pxad_filter_fn(struct dma_chan *chan, void *param)
1458 {
1459 	struct pxad_chan *c = to_pxad_chan(chan);
1460 	struct pxad_param *p = param;
1461 
1462 	if (chan->device->dev->driver != &pxad_driver.driver)
1463 		return false;
1464 
1465 	c->drcmr = p->drcmr;
1466 	c->prio = p->prio;
1467 
1468 	return true;
1469 }
1470 EXPORT_SYMBOL_GPL(pxad_filter_fn);
1471 
1472 int pxad_toggle_reserved_channel(int legacy_channel)
1473 {
1474 	if (legacy_unavailable & (BIT(legacy_channel)))
1475 		return -EBUSY;
1476 	legacy_reserved ^= BIT(legacy_channel);
1477 	return 0;
1478 }
1479 EXPORT_SYMBOL_GPL(pxad_toggle_reserved_channel);
1480 
1481 module_platform_driver(pxad_driver);
1482 
1483 MODULE_DESCRIPTION("Marvell PXA Peripheral DMA Driver");
1484 MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");
1485 MODULE_LICENSE("GPL v2");
1486