xref: /linux/drivers/dma/pxa_dma.c (revision f3b8788cde61b02f1e6c202f8fac4360e6adbafc)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2015 Robert Jarzmik <robert.jarzmik@free.fr>
4  */
5 
6 #include <linux/err.h>
7 #include <linux/module.h>
8 #include <linux/init.h>
9 #include <linux/types.h>
10 #include <linux/interrupt.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/slab.h>
13 #include <linux/dmaengine.h>
14 #include <linux/platform_device.h>
15 #include <linux/device.h>
16 #include <linux/platform_data/mmp_dma.h>
17 #include <linux/dmapool.h>
18 #include <linux/of.h>
19 #include <linux/of_dma.h>
20 #include <linux/wait.h>
21 #include <linux/dma/pxa-dma.h>
22 
23 #include "dmaengine.h"
24 #include "virt-dma.h"
25 
26 #define DCSR(n)		(0x0000 + ((n) << 2))
27 #define DALGN(n)	0x00a0
28 #define DINT		0x00f0
29 #define DDADR(n)	(0x0200 + ((n) << 4))
30 #define DSADR(n)	(0x0204 + ((n) << 4))
31 #define DTADR(n)	(0x0208 + ((n) << 4))
32 #define DCMD(n)		(0x020c + ((n) << 4))
33 
34 #define PXA_DCSR_RUN		BIT(31)	/* Run Bit (read / write) */
35 #define PXA_DCSR_NODESC		BIT(30)	/* No-Descriptor Fetch (read / write) */
36 #define PXA_DCSR_STOPIRQEN	BIT(29)	/* Stop Interrupt Enable (R/W) */
37 #define PXA_DCSR_REQPEND	BIT(8)	/* Request Pending (read-only) */
38 #define PXA_DCSR_STOPSTATE	BIT(3)	/* Stop State (read-only) */
39 #define PXA_DCSR_ENDINTR	BIT(2)	/* End Interrupt (read / write) */
40 #define PXA_DCSR_STARTINTR	BIT(1)	/* Start Interrupt (read / write) */
41 #define PXA_DCSR_BUSERR		BIT(0)	/* Bus Error Interrupt (read / write) */
42 
43 #define PXA_DCSR_EORIRQEN	BIT(28)	/* End of Receive IRQ Enable (R/W) */
44 #define PXA_DCSR_EORJMPEN	BIT(27)	/* Jump to next descriptor on EOR */
45 #define PXA_DCSR_EORSTOPEN	BIT(26)	/* STOP on an EOR */
46 #define PXA_DCSR_SETCMPST	BIT(25)	/* Set Descriptor Compare Status */
47 #define PXA_DCSR_CLRCMPST	BIT(24)	/* Clear Descriptor Compare Status */
48 #define PXA_DCSR_CMPST		BIT(10)	/* The Descriptor Compare Status */
49 #define PXA_DCSR_EORINTR	BIT(9)	/* The end of Receive */
50 
51 #define DRCMR_MAPVLD	BIT(7)	/* Map Valid (read / write) */
52 #define DRCMR_CHLNUM	0x1f	/* mask for Channel Number (read / write) */
53 
54 #define DDADR_DESCADDR	0xfffffff0	/* Address of next descriptor (mask) */
55 #define DDADR_STOP	BIT(0)	/* Stop (read / write) */
56 
57 #define PXA_DCMD_INCSRCADDR	BIT(31)	/* Source Address Increment Setting. */
58 #define PXA_DCMD_INCTRGADDR	BIT(30)	/* Target Address Increment Setting. */
59 #define PXA_DCMD_FLOWSRC	BIT(29)	/* Flow Control by the source. */
60 #define PXA_DCMD_FLOWTRG	BIT(28)	/* Flow Control by the target. */
61 #define PXA_DCMD_STARTIRQEN	BIT(22)	/* Start Interrupt Enable */
62 #define PXA_DCMD_ENDIRQEN	BIT(21)	/* End Interrupt Enable */
63 #define PXA_DCMD_ENDIAN		BIT(18)	/* Device Endian-ness. */
64 #define PXA_DCMD_BURST8		(1 << 16)	/* 8 byte burst */
65 #define PXA_DCMD_BURST16	(2 << 16)	/* 16 byte burst */
66 #define PXA_DCMD_BURST32	(3 << 16)	/* 32 byte burst */
67 #define PXA_DCMD_WIDTH1		(1 << 14)	/* 1 byte width */
68 #define PXA_DCMD_WIDTH2		(2 << 14)	/* 2 byte width (HalfWord) */
69 #define PXA_DCMD_WIDTH4		(3 << 14)	/* 4 byte width (Word) */
70 #define PXA_DCMD_LENGTH		0x01fff		/* length mask (max = 8K - 1) */
71 
72 #define PDMA_ALIGNMENT		3
73 #define PDMA_MAX_DESC_BYTES	(PXA_DCMD_LENGTH & ~((1 << PDMA_ALIGNMENT) - 1))
74 
75 struct pxad_desc_hw {
76 	u32 ddadr;	/* Points to the next descriptor + flags */
77 	u32 dsadr;	/* DSADR value for the current transfer */
78 	u32 dtadr;	/* DTADR value for the current transfer */
79 	u32 dcmd;	/* DCMD value for the current transfer */
80 } __aligned(16);
81 
82 struct pxad_desc_sw {
83 	struct virt_dma_desc	vd;		/* Virtual descriptor */
84 	int			nb_desc;	/* Number of hw. descriptors */
85 	size_t			len;		/* Number of bytes xfered */
86 	dma_addr_t		first;		/* First descriptor's addr */
87 
88 	/* At least one descriptor has an src/dst address not multiple of 8 */
89 	bool			misaligned;
90 	bool			cyclic;
91 	struct dma_pool		*desc_pool;	/* Channel's used allocator */
92 
93 	struct pxad_desc_hw	*hw_desc[] __counted_by(nb_desc);
94 						/* DMA coherent descriptors */
95 };
96 
97 struct pxad_phy {
98 	int			idx;
99 	void __iomem		*base;
100 	struct pxad_chan	*vchan;
101 };
102 
103 struct pxad_chan {
104 	struct virt_dma_chan	vc;		/* Virtual channel */
105 	u32			drcmr;		/* Requestor of the channel */
106 	enum pxad_chan_prio	prio;		/* Required priority of phy */
107 	/*
108 	 * At least one desc_sw in submitted or issued transfers on this channel
109 	 * has one address such as: addr % 8 != 0. This implies the DALGN
110 	 * setting on the phy.
111 	 */
112 	bool			misaligned;
113 	struct dma_slave_config	cfg;		/* Runtime config */
114 
115 	/* protected by vc->lock */
116 	struct pxad_phy		*phy;
117 	struct dma_pool		*desc_pool;	/* Descriptors pool */
118 	dma_cookie_t		bus_error;
119 
120 	wait_queue_head_t	wq_state;
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_chan;
133 #endif
134 };
135 
136 #define tx_to_pxad_desc(tx)					\
137 	container_of(tx, struct pxad_desc_sw, async_tx)
138 #define to_pxad_chan(dchan)					\
139 	container_of(dchan, struct pxad_chan, vc.chan)
140 #define to_pxad_dev(dmadev)					\
141 	container_of(dmadev, struct pxad_device, slave)
142 #define to_pxad_sw_desc(_vd)				\
143 	container_of((_vd), struct pxad_desc_sw, vd)
144 
145 #define _phy_readl_relaxed(phy, _reg)					\
146 	readl_relaxed((phy)->base + _reg((phy)->idx))
147 #define phy_readl_relaxed(phy, _reg)					\
148 	({								\
149 		u32 _v;							\
150 		_v = readl_relaxed((phy)->base + _reg((phy)->idx));	\
151 		dev_vdbg(&phy->vchan->vc.chan.dev->device,		\
152 			 "%s(): readl(%s): 0x%08x\n", __func__, #_reg,	\
153 			  _v);						\
154 		_v;							\
155 	})
156 #define phy_writel(phy, val, _reg)					\
157 	do {								\
158 		writel((val), (phy)->base + _reg((phy)->idx));		\
159 		dev_vdbg(&phy->vchan->vc.chan.dev->device,		\
160 			 "%s(): writel(0x%08x, %s)\n",			\
161 			 __func__, (u32)(val), #_reg);			\
162 	} while (0)
163 #define phy_writel_relaxed(phy, val, _reg)				\
164 	do {								\
165 		writel_relaxed((val), (phy)->base + _reg((phy)->idx));	\
166 		dev_vdbg(&phy->vchan->vc.chan.dev->device,		\
167 			 "%s(): writel_relaxed(0x%08x, %s)\n",		\
168 			 __func__, (u32)(val), #_reg);			\
169 	} while (0)
170 
171 static unsigned int pxad_drcmr(unsigned int line)
172 {
173 	if (line < 64)
174 		return 0x100 + line * 4;
175 	return 0x1000 + line * 4;
176 }
177 
178 static bool pxad_filter_fn(struct dma_chan *chan, void *param);
179 
180 /*
181  * Debug fs
182  */
183 #ifdef CONFIG_DEBUG_FS
184 #include <linux/debugfs.h>
185 #include <linux/uaccess.h>
186 #include <linux/seq_file.h>
187 
188 static int requester_chan_show(struct seq_file *s, void *p)
189 {
190 	struct pxad_phy *phy = s->private;
191 	int i;
192 	u32 drcmr;
193 
194 	seq_printf(s, "DMA channel %d requester :\n", phy->idx);
195 	for (i = 0; i < 70; i++) {
196 		drcmr = readl_relaxed(phy->base + pxad_drcmr(i));
197 		if ((drcmr & DRCMR_CHLNUM) == phy->idx)
198 			seq_printf(s, "\tRequester %d (MAPVLD=%d)\n", i,
199 				   !!(drcmr & DRCMR_MAPVLD));
200 	}
201 	return 0;
202 }
203 
204 static inline int dbg_burst_from_dcmd(u32 dcmd)
205 {
206 	int burst = (dcmd >> 16) & 0x3;
207 
208 	return burst ? 4 << burst : 0;
209 }
210 
211 static int is_phys_valid(unsigned long addr)
212 {
213 	return pfn_valid(__phys_to_pfn(addr));
214 }
215 
216 #define PXA_DCSR_STR(flag) (dcsr & PXA_DCSR_##flag ? #flag" " : "")
217 #define PXA_DCMD_STR(flag) (dcmd & PXA_DCMD_##flag ? #flag" " : "")
218 
219 static int descriptors_show(struct seq_file *s, void *p)
220 {
221 	struct pxad_phy *phy = s->private;
222 	int i, max_show = 20, burst, width;
223 	u32 dcmd;
224 	unsigned long phys_desc, ddadr;
225 	struct pxad_desc_hw *desc;
226 
227 	phys_desc = ddadr = _phy_readl_relaxed(phy, DDADR);
228 
229 	seq_printf(s, "DMA channel %d descriptors :\n", phy->idx);
230 	seq_printf(s, "[%03d] First descriptor unknown\n", 0);
231 	for (i = 1; i < max_show && is_phys_valid(phys_desc); i++) {
232 		desc = phys_to_virt(phys_desc);
233 		dcmd = desc->dcmd;
234 		burst = dbg_burst_from_dcmd(dcmd);
235 		width = (1 << ((dcmd >> 14) & 0x3)) >> 1;
236 
237 		seq_printf(s, "[%03d] Desc at %08lx(virt %p)\n",
238 			   i, phys_desc, desc);
239 		seq_printf(s, "\tDDADR = %08x\n", desc->ddadr);
240 		seq_printf(s, "\tDSADR = %08x\n", desc->dsadr);
241 		seq_printf(s, "\tDTADR = %08x\n", desc->dtadr);
242 		seq_printf(s, "\tDCMD  = %08x (%s%s%s%s%s%s%sburst=%d width=%d len=%d)\n",
243 			   dcmd,
244 			   PXA_DCMD_STR(INCSRCADDR), PXA_DCMD_STR(INCTRGADDR),
245 			   PXA_DCMD_STR(FLOWSRC), PXA_DCMD_STR(FLOWTRG),
246 			   PXA_DCMD_STR(STARTIRQEN), PXA_DCMD_STR(ENDIRQEN),
247 			   PXA_DCMD_STR(ENDIAN), burst, width,
248 			   dcmd & PXA_DCMD_LENGTH);
249 		phys_desc = desc->ddadr;
250 	}
251 	if (i == max_show)
252 		seq_printf(s, "[%03d] Desc at %08lx ... max display reached\n",
253 			   i, phys_desc);
254 	else
255 		seq_printf(s, "[%03d] Desc at %08lx is %s\n",
256 			   i, phys_desc, phys_desc == DDADR_STOP ?
257 			   "DDADR_STOP" : "invalid");
258 
259 	return 0;
260 }
261 
262 static int chan_state_show(struct seq_file *s, void *p)
263 {
264 	struct pxad_phy *phy = s->private;
265 	u32 dcsr, dcmd;
266 	int burst, width;
267 	static const char * const str_prio[] = {
268 		"high", "normal", "low", "invalid"
269 	};
270 
271 	dcsr = _phy_readl_relaxed(phy, DCSR);
272 	dcmd = _phy_readl_relaxed(phy, DCMD);
273 	burst = dbg_burst_from_dcmd(dcmd);
274 	width = (1 << ((dcmd >> 14) & 0x3)) >> 1;
275 
276 	seq_printf(s, "DMA channel %d\n", phy->idx);
277 	seq_printf(s, "\tPriority : %s\n",
278 			  str_prio[(phy->idx & 0xf) / 4]);
279 	seq_printf(s, "\tUnaligned transfer bit: %s\n",
280 			  _phy_readl_relaxed(phy, DALGN) & BIT(phy->idx) ?
281 			  "yes" : "no");
282 	seq_printf(s, "\tDCSR  = %08x (%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s)\n",
283 		   dcsr, PXA_DCSR_STR(RUN), PXA_DCSR_STR(NODESC),
284 		   PXA_DCSR_STR(STOPIRQEN), PXA_DCSR_STR(EORIRQEN),
285 		   PXA_DCSR_STR(EORJMPEN), PXA_DCSR_STR(EORSTOPEN),
286 		   PXA_DCSR_STR(SETCMPST), PXA_DCSR_STR(CLRCMPST),
287 		   PXA_DCSR_STR(CMPST), PXA_DCSR_STR(EORINTR),
288 		   PXA_DCSR_STR(REQPEND), PXA_DCSR_STR(STOPSTATE),
289 		   PXA_DCSR_STR(ENDINTR), PXA_DCSR_STR(STARTINTR),
290 		   PXA_DCSR_STR(BUSERR));
291 
292 	seq_printf(s, "\tDCMD  = %08x (%s%s%s%s%s%s%sburst=%d width=%d len=%d)\n",
293 		   dcmd,
294 		   PXA_DCMD_STR(INCSRCADDR), PXA_DCMD_STR(INCTRGADDR),
295 		   PXA_DCMD_STR(FLOWSRC), PXA_DCMD_STR(FLOWTRG),
296 		   PXA_DCMD_STR(STARTIRQEN), PXA_DCMD_STR(ENDIRQEN),
297 		   PXA_DCMD_STR(ENDIAN), burst, width, dcmd & PXA_DCMD_LENGTH);
298 	seq_printf(s, "\tDSADR = %08x\n", _phy_readl_relaxed(phy, DSADR));
299 	seq_printf(s, "\tDTADR = %08x\n", _phy_readl_relaxed(phy, DTADR));
300 	seq_printf(s, "\tDDADR = %08x\n", _phy_readl_relaxed(phy, DDADR));
301 
302 	return 0;
303 }
304 
305 static int state_show(struct seq_file *s, void *p)
306 {
307 	struct pxad_device *pdev = s->private;
308 
309 	/* basic device status */
310 	seq_puts(s, "DMA engine status\n");
311 	seq_printf(s, "\tChannel number: %d\n", pdev->nr_chans);
312 
313 	return 0;
314 }
315 
316 DEFINE_SHOW_ATTRIBUTE(state);
317 DEFINE_SHOW_ATTRIBUTE(chan_state);
318 DEFINE_SHOW_ATTRIBUTE(descriptors);
319 DEFINE_SHOW_ATTRIBUTE(requester_chan);
320 
321 static struct dentry *pxad_dbg_alloc_chan(struct pxad_device *pdev,
322 					     int ch, struct dentry *chandir)
323 {
324 	char chan_name[11];
325 	struct dentry *chan;
326 	void *dt;
327 
328 	scnprintf(chan_name, sizeof(chan_name), "%d", ch);
329 	chan = debugfs_create_dir(chan_name, chandir);
330 	dt = (void *)&pdev->phys[ch];
331 
332 	debugfs_create_file("state", 0400, chan, dt, &chan_state_fops);
333 	debugfs_create_file("descriptors", 0400, chan, dt, &descriptors_fops);
334 	debugfs_create_file("requesters", 0400, chan, dt, &requester_chan_fops);
335 
336 	return chan;
337 }
338 
339 static void pxad_init_debugfs(struct pxad_device *pdev)
340 {
341 	int i;
342 	struct dentry *chandir;
343 
344 	pdev->dbgfs_chan =
345 		kmalloc_array(pdev->nr_chans, sizeof(struct dentry *),
346 			      GFP_KERNEL);
347 	if (!pdev->dbgfs_chan)
348 		return;
349 
350 	pdev->dbgfs_root = debugfs_create_dir(dev_name(pdev->slave.dev), NULL);
351 
352 	debugfs_create_file("state", 0400, pdev->dbgfs_root, pdev, &state_fops);
353 
354 	chandir = debugfs_create_dir("channels", pdev->dbgfs_root);
355 
356 	for (i = 0; i < pdev->nr_chans; i++)
357 		pdev->dbgfs_chan[i] = pxad_dbg_alloc_chan(pdev, i, chandir);
358 }
359 
360 static void pxad_cleanup_debugfs(struct pxad_device *pdev)
361 {
362 	debugfs_remove_recursive(pdev->dbgfs_root);
363 }
364 #else
365 static inline void pxad_init_debugfs(struct pxad_device *pdev) {}
366 static inline void pxad_cleanup_debugfs(struct pxad_device *pdev) {}
367 #endif
368 
369 static struct pxad_phy *lookup_phy(struct pxad_chan *pchan)
370 {
371 	int prio, i;
372 	struct pxad_device *pdev = to_pxad_dev(pchan->vc.chan.device);
373 	struct pxad_phy *phy, *found = NULL;
374 	unsigned long flags;
375 
376 	/*
377 	 * dma channel priorities
378 	 * ch 0 - 3,  16 - 19  <--> (0)
379 	 * ch 4 - 7,  20 - 23  <--> (1)
380 	 * ch 8 - 11, 24 - 27  <--> (2)
381 	 * ch 12 - 15, 28 - 31  <--> (3)
382 	 */
383 
384 	spin_lock_irqsave(&pdev->phy_lock, flags);
385 	for (prio = pchan->prio; prio >= PXAD_PRIO_HIGHEST; prio--) {
386 		for (i = 0; i < pdev->nr_chans; i++) {
387 			if (prio != (i & 0xf) >> 2)
388 				continue;
389 			phy = &pdev->phys[i];
390 			if (!phy->vchan) {
391 				phy->vchan = pchan;
392 				found = phy;
393 				goto out_unlock;
394 			}
395 		}
396 	}
397 
398 out_unlock:
399 	spin_unlock_irqrestore(&pdev->phy_lock, flags);
400 	dev_dbg(&pchan->vc.chan.dev->device,
401 		"%s(): phy=%p(%d)\n", __func__, found,
402 		found ? found->idx : -1);
403 
404 	return found;
405 }
406 
407 static void pxad_free_phy(struct pxad_chan *chan)
408 {
409 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
410 	unsigned long flags;
411 	u32 reg;
412 
413 	dev_dbg(&chan->vc.chan.dev->device,
414 		"%s(): freeing\n", __func__);
415 	if (!chan->phy)
416 		return;
417 
418 	/* clear the channel mapping in DRCMR */
419 	if (chan->drcmr <= pdev->nr_requestors) {
420 		reg = pxad_drcmr(chan->drcmr);
421 		writel_relaxed(0, chan->phy->base + reg);
422 	}
423 
424 	spin_lock_irqsave(&pdev->phy_lock, flags);
425 	chan->phy->vchan = NULL;
426 	chan->phy = NULL;
427 	spin_unlock_irqrestore(&pdev->phy_lock, flags);
428 }
429 
430 static bool is_chan_running(struct pxad_chan *chan)
431 {
432 	u32 dcsr;
433 	struct pxad_phy *phy = chan->phy;
434 
435 	if (!phy)
436 		return false;
437 	dcsr = phy_readl_relaxed(phy, DCSR);
438 	return dcsr & PXA_DCSR_RUN;
439 }
440 
441 static bool is_running_chan_misaligned(struct pxad_chan *chan)
442 {
443 	u32 dalgn;
444 
445 	BUG_ON(!chan->phy);
446 	dalgn = phy_readl_relaxed(chan->phy, DALGN);
447 	return dalgn & (BIT(chan->phy->idx));
448 }
449 
450 static void phy_enable(struct pxad_phy *phy, bool misaligned)
451 {
452 	struct pxad_device *pdev;
453 	u32 reg, dalgn;
454 
455 	if (!phy->vchan)
456 		return;
457 
458 	dev_dbg(&phy->vchan->vc.chan.dev->device,
459 		"%s(); phy=%p(%d) misaligned=%d\n", __func__,
460 		phy, phy->idx, misaligned);
461 
462 	pdev = to_pxad_dev(phy->vchan->vc.chan.device);
463 	if (phy->vchan->drcmr <= pdev->nr_requestors) {
464 		reg = pxad_drcmr(phy->vchan->drcmr);
465 		writel_relaxed(DRCMR_MAPVLD | phy->idx, phy->base + reg);
466 	}
467 
468 	dalgn = phy_readl_relaxed(phy, DALGN);
469 	if (misaligned)
470 		dalgn |= BIT(phy->idx);
471 	else
472 		dalgn &= ~BIT(phy->idx);
473 	phy_writel_relaxed(phy, dalgn, DALGN);
474 
475 	phy_writel(phy, PXA_DCSR_STOPIRQEN | PXA_DCSR_ENDINTR |
476 		   PXA_DCSR_BUSERR | PXA_DCSR_RUN, DCSR);
477 }
478 
479 static void phy_disable(struct pxad_phy *phy)
480 {
481 	u32 dcsr;
482 
483 	if (!phy)
484 		return;
485 
486 	dcsr = phy_readl_relaxed(phy, DCSR);
487 	dev_dbg(&phy->vchan->vc.chan.dev->device,
488 		"%s(): phy=%p(%d)\n", __func__, phy, phy->idx);
489 	phy_writel(phy, dcsr & ~PXA_DCSR_RUN & ~PXA_DCSR_STOPIRQEN, DCSR);
490 }
491 
492 static void pxad_launch_chan(struct pxad_chan *chan,
493 				 struct pxad_desc_sw *desc)
494 {
495 	dev_dbg(&chan->vc.chan.dev->device,
496 		"%s(): desc=%p\n", __func__, desc);
497 	if (!chan->phy) {
498 		chan->phy = lookup_phy(chan);
499 		if (!chan->phy) {
500 			dev_dbg(&chan->vc.chan.dev->device,
501 				"%s(): no free dma channel\n", __func__);
502 			return;
503 		}
504 	}
505 	chan->bus_error = 0;
506 
507 	/*
508 	 * Program the descriptor's address into the DMA controller,
509 	 * then start the DMA transaction
510 	 */
511 	phy_writel(chan->phy, desc->first, DDADR);
512 	phy_enable(chan->phy, chan->misaligned);
513 	wake_up(&chan->wq_state);
514 }
515 
516 static void set_updater_desc(struct pxad_desc_sw *sw_desc,
517 			     unsigned long flags)
518 {
519 	struct pxad_desc_hw *updater =
520 		sw_desc->hw_desc[sw_desc->nb_desc - 1];
521 	dma_addr_t dma = sw_desc->hw_desc[sw_desc->nb_desc - 2]->ddadr;
522 
523 	updater->ddadr = DDADR_STOP;
524 	updater->dsadr = dma;
525 	updater->dtadr = dma + 8;
526 	updater->dcmd = PXA_DCMD_WIDTH4 | PXA_DCMD_BURST32 |
527 		(PXA_DCMD_LENGTH & sizeof(u32));
528 	if (flags & DMA_PREP_INTERRUPT)
529 		updater->dcmd |= PXA_DCMD_ENDIRQEN;
530 	if (sw_desc->cyclic)
531 		sw_desc->hw_desc[sw_desc->nb_desc - 2]->ddadr = sw_desc->first;
532 }
533 
534 static bool is_desc_completed(struct virt_dma_desc *vd)
535 {
536 	struct pxad_desc_sw *sw_desc = to_pxad_sw_desc(vd);
537 	struct pxad_desc_hw *updater =
538 		sw_desc->hw_desc[sw_desc->nb_desc - 1];
539 
540 	return updater->dtadr != (updater->dsadr + 8);
541 }
542 
543 static void pxad_desc_chain(struct virt_dma_desc *vd1,
544 				struct virt_dma_desc *vd2)
545 {
546 	struct pxad_desc_sw *desc1 = to_pxad_sw_desc(vd1);
547 	struct pxad_desc_sw *desc2 = to_pxad_sw_desc(vd2);
548 	dma_addr_t dma_to_chain;
549 
550 	dma_to_chain = desc2->first;
551 	desc1->hw_desc[desc1->nb_desc - 1]->ddadr = dma_to_chain;
552 }
553 
554 static bool pxad_try_hotchain(struct virt_dma_chan *vc,
555 				  struct virt_dma_desc *vd)
556 {
557 	struct virt_dma_desc *vd_last_issued = NULL;
558 	struct pxad_chan *chan = to_pxad_chan(&vc->chan);
559 
560 	/*
561 	 * Attempt to hot chain the tx if the phy is still running. This is
562 	 * considered successful only if either the channel is still running
563 	 * after the chaining, or if the chained transfer is completed after
564 	 * having been hot chained.
565 	 * A change of alignment is not allowed, and forbids hotchaining.
566 	 */
567 	if (is_chan_running(chan)) {
568 		BUG_ON(list_empty(&vc->desc_issued));
569 
570 		if (!is_running_chan_misaligned(chan) &&
571 		    to_pxad_sw_desc(vd)->misaligned)
572 			return false;
573 
574 		vd_last_issued = list_entry(vc->desc_issued.prev,
575 					    struct virt_dma_desc, node);
576 		pxad_desc_chain(vd_last_issued, vd);
577 		if (is_chan_running(chan) || is_desc_completed(vd))
578 			return true;
579 	}
580 
581 	return false;
582 }
583 
584 static unsigned int clear_chan_irq(struct pxad_phy *phy)
585 {
586 	u32 dcsr;
587 	u32 dint = readl(phy->base + DINT);
588 
589 	if (!(dint & BIT(phy->idx)))
590 		return PXA_DCSR_RUN;
591 
592 	/* clear irq */
593 	dcsr = phy_readl_relaxed(phy, DCSR);
594 	phy_writel(phy, dcsr, DCSR);
595 	if ((dcsr & PXA_DCSR_BUSERR) && (phy->vchan))
596 		dev_warn(&phy->vchan->vc.chan.dev->device,
597 			 "%s(chan=%p): PXA_DCSR_BUSERR\n",
598 			 __func__, &phy->vchan);
599 
600 	return dcsr & ~PXA_DCSR_RUN;
601 }
602 
603 static irqreturn_t pxad_chan_handler(int irq, void *dev_id)
604 {
605 	struct pxad_phy *phy = dev_id;
606 	struct pxad_chan *chan = phy->vchan;
607 	struct virt_dma_desc *vd, *tmp;
608 	unsigned int dcsr;
609 	bool vd_completed;
610 	dma_cookie_t last_started = 0;
611 
612 	BUG_ON(!chan);
613 
614 	dcsr = clear_chan_irq(phy);
615 	if (dcsr & PXA_DCSR_RUN)
616 		return IRQ_NONE;
617 
618 	spin_lock(&chan->vc.lock);
619 	list_for_each_entry_safe(vd, tmp, &chan->vc.desc_issued, node) {
620 		vd_completed = is_desc_completed(vd);
621 		dev_dbg(&chan->vc.chan.dev->device,
622 			"%s(): checking txd %p[%x]: completed=%d dcsr=0x%x\n",
623 			__func__, vd, vd->tx.cookie, vd_completed,
624 			dcsr);
625 		last_started = vd->tx.cookie;
626 		if (to_pxad_sw_desc(vd)->cyclic) {
627 			vchan_cyclic_callback(vd);
628 			break;
629 		}
630 		if (vd_completed) {
631 			list_del(&vd->node);
632 			vchan_cookie_complete(vd);
633 		} else {
634 			break;
635 		}
636 	}
637 
638 	if (dcsr & PXA_DCSR_BUSERR) {
639 		chan->bus_error = last_started;
640 		phy_disable(phy);
641 	}
642 
643 	if (!chan->bus_error && dcsr & PXA_DCSR_STOPSTATE) {
644 		dev_dbg(&chan->vc.chan.dev->device,
645 		"%s(): channel stopped, submitted_empty=%d issued_empty=%d",
646 			__func__,
647 			list_empty(&chan->vc.desc_submitted),
648 			list_empty(&chan->vc.desc_issued));
649 		phy_writel_relaxed(phy, dcsr & ~PXA_DCSR_STOPIRQEN, DCSR);
650 
651 		if (list_empty(&chan->vc.desc_issued)) {
652 			chan->misaligned =
653 				!list_empty(&chan->vc.desc_submitted);
654 		} else {
655 			vd = list_first_entry(&chan->vc.desc_issued,
656 					      struct virt_dma_desc, node);
657 			pxad_launch_chan(chan, to_pxad_sw_desc(vd));
658 		}
659 	}
660 	spin_unlock(&chan->vc.lock);
661 	wake_up(&chan->wq_state);
662 
663 	return IRQ_HANDLED;
664 }
665 
666 static irqreturn_t pxad_int_handler(int irq, void *dev_id)
667 {
668 	struct pxad_device *pdev = dev_id;
669 	struct pxad_phy *phy;
670 	u32 dint = readl(pdev->base + DINT);
671 	int i, ret = IRQ_NONE;
672 
673 	while (dint) {
674 		i = __ffs(dint);
675 		dint &= (dint - 1);
676 		phy = &pdev->phys[i];
677 		if (pxad_chan_handler(irq, phy) == IRQ_HANDLED)
678 			ret = IRQ_HANDLED;
679 	}
680 
681 	return ret;
682 }
683 
684 static int pxad_alloc_chan_resources(struct dma_chan *dchan)
685 {
686 	struct pxad_chan *chan = to_pxad_chan(dchan);
687 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
688 
689 	if (chan->desc_pool)
690 		return 1;
691 
692 	chan->desc_pool = dma_pool_create(dma_chan_name(dchan),
693 					  pdev->slave.dev,
694 					  sizeof(struct pxad_desc_hw),
695 					  __alignof__(struct pxad_desc_hw),
696 					  0);
697 	if (!chan->desc_pool) {
698 		dev_err(&chan->vc.chan.dev->device,
699 			"%s(): unable to allocate descriptor pool\n",
700 			__func__);
701 		return -ENOMEM;
702 	}
703 
704 	return 1;
705 }
706 
707 static void pxad_free_chan_resources(struct dma_chan *dchan)
708 {
709 	struct pxad_chan *chan = to_pxad_chan(dchan);
710 
711 	vchan_free_chan_resources(&chan->vc);
712 	dma_pool_destroy(chan->desc_pool);
713 	chan->desc_pool = NULL;
714 
715 	chan->drcmr = U32_MAX;
716 	chan->prio = PXAD_PRIO_LOWEST;
717 }
718 
719 static void pxad_free_desc(struct virt_dma_desc *vd)
720 {
721 	int i;
722 	dma_addr_t dma;
723 	struct pxad_desc_sw *sw_desc = to_pxad_sw_desc(vd);
724 
725 	for (i = sw_desc->nb_desc - 1; i >= 0; i--) {
726 		if (i > 0)
727 			dma = sw_desc->hw_desc[i - 1]->ddadr;
728 		else
729 			dma = sw_desc->first;
730 		dma_pool_free(sw_desc->desc_pool,
731 			      sw_desc->hw_desc[i], dma);
732 	}
733 	sw_desc->nb_desc = 0;
734 	kfree(sw_desc);
735 }
736 
737 static struct pxad_desc_sw *
738 pxad_alloc_desc(struct pxad_chan *chan, unsigned int nb_hw_desc)
739 {
740 	struct pxad_desc_sw *sw_desc;
741 	dma_addr_t dma;
742 	void *desc;
743 	int i;
744 
745 	sw_desc = kzalloc(struct_size(sw_desc, hw_desc, nb_hw_desc),
746 			  GFP_NOWAIT);
747 	if (!sw_desc)
748 		return NULL;
749 	sw_desc->desc_pool = chan->desc_pool;
750 
751 	for (i = 0; i < nb_hw_desc; i++) {
752 		desc = dma_pool_alloc(sw_desc->desc_pool, GFP_NOWAIT, &dma);
753 		if (!desc) {
754 			dev_err(&chan->vc.chan.dev->device,
755 				"%s(): Couldn't allocate the %dth hw_desc from dma_pool %p\n",
756 				__func__, i, sw_desc->desc_pool);
757 			goto err;
758 		}
759 
760 		sw_desc->nb_desc++;
761 		sw_desc->hw_desc[i] = desc;
762 
763 		if (i == 0)
764 			sw_desc->first = dma;
765 		else
766 			sw_desc->hw_desc[i - 1]->ddadr = dma;
767 	}
768 
769 	return sw_desc;
770 err:
771 	pxad_free_desc(&sw_desc->vd);
772 	return NULL;
773 }
774 
775 static dma_cookie_t pxad_tx_submit(struct dma_async_tx_descriptor *tx)
776 {
777 	struct virt_dma_chan *vc = to_virt_chan(tx->chan);
778 	struct pxad_chan *chan = to_pxad_chan(&vc->chan);
779 	struct virt_dma_desc *vd_chained = NULL,
780 		*vd = container_of(tx, struct virt_dma_desc, tx);
781 	dma_cookie_t cookie;
782 	unsigned long flags;
783 
784 	set_updater_desc(to_pxad_sw_desc(vd), tx->flags);
785 
786 	spin_lock_irqsave(&vc->lock, flags);
787 	cookie = dma_cookie_assign(tx);
788 
789 	if (list_empty(&vc->desc_submitted) && pxad_try_hotchain(vc, vd)) {
790 		list_move_tail(&vd->node, &vc->desc_issued);
791 		dev_dbg(&chan->vc.chan.dev->device,
792 			"%s(): txd %p[%x]: submitted (hot linked)\n",
793 			__func__, vd, cookie);
794 		goto out;
795 	}
796 
797 	/*
798 	 * Fallback to placing the tx in the submitted queue
799 	 */
800 	if (!list_empty(&vc->desc_submitted)) {
801 		vd_chained = list_entry(vc->desc_submitted.prev,
802 					struct virt_dma_desc, node);
803 		/*
804 		 * Only chain the descriptors if no new misalignment is
805 		 * introduced. If a new misalignment is chained, let the channel
806 		 * stop, and be relaunched in misalign mode from the irq
807 		 * handler.
808 		 */
809 		if (chan->misaligned || !to_pxad_sw_desc(vd)->misaligned)
810 			pxad_desc_chain(vd_chained, vd);
811 		else
812 			vd_chained = NULL;
813 	}
814 	dev_dbg(&chan->vc.chan.dev->device,
815 		"%s(): txd %p[%x]: submitted (%s linked)\n",
816 		__func__, vd, cookie, vd_chained ? "cold" : "not");
817 	list_move_tail(&vd->node, &vc->desc_submitted);
818 	chan->misaligned |= to_pxad_sw_desc(vd)->misaligned;
819 
820 out:
821 	spin_unlock_irqrestore(&vc->lock, flags);
822 	return cookie;
823 }
824 
825 static void pxad_issue_pending(struct dma_chan *dchan)
826 {
827 	struct pxad_chan *chan = to_pxad_chan(dchan);
828 	struct virt_dma_desc *vd_first;
829 	unsigned long flags;
830 
831 	spin_lock_irqsave(&chan->vc.lock, flags);
832 	if (list_empty(&chan->vc.desc_submitted))
833 		goto out;
834 
835 	vd_first = list_first_entry(&chan->vc.desc_submitted,
836 				    struct virt_dma_desc, node);
837 	dev_dbg(&chan->vc.chan.dev->device,
838 		"%s(): txd %p[%x]", __func__, vd_first, vd_first->tx.cookie);
839 
840 	vchan_issue_pending(&chan->vc);
841 	if (!pxad_try_hotchain(&chan->vc, vd_first))
842 		pxad_launch_chan(chan, to_pxad_sw_desc(vd_first));
843 out:
844 	spin_unlock_irqrestore(&chan->vc.lock, flags);
845 }
846 
847 static inline struct dma_async_tx_descriptor *
848 pxad_tx_prep(struct virt_dma_chan *vc, struct virt_dma_desc *vd,
849 		 unsigned long tx_flags)
850 {
851 	struct dma_async_tx_descriptor *tx;
852 	struct pxad_chan *chan = container_of(vc, struct pxad_chan, vc);
853 
854 	INIT_LIST_HEAD(&vd->node);
855 	tx = vchan_tx_prep(vc, vd, tx_flags);
856 	tx->tx_submit = pxad_tx_submit;
857 	dev_dbg(&chan->vc.chan.dev->device,
858 		"%s(): vc=%p txd=%p[%x] flags=0x%lx\n", __func__,
859 		vc, vd, vd->tx.cookie,
860 		tx_flags);
861 
862 	return tx;
863 }
864 
865 static void pxad_get_config(struct pxad_chan *chan,
866 			    enum dma_transfer_direction dir,
867 			    u32 *dcmd, u32 *dev_src, u32 *dev_dst)
868 {
869 	u32 maxburst = 0, dev_addr = 0;
870 	enum dma_slave_buswidth width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
871 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
872 
873 	*dcmd = 0;
874 	if (dir == DMA_DEV_TO_MEM) {
875 		maxburst = chan->cfg.src_maxburst;
876 		width = chan->cfg.src_addr_width;
877 		dev_addr = chan->cfg.src_addr;
878 		*dev_src = dev_addr;
879 		*dcmd |= PXA_DCMD_INCTRGADDR;
880 		if (chan->drcmr <= pdev->nr_requestors)
881 			*dcmd |= PXA_DCMD_FLOWSRC;
882 	}
883 	if (dir == DMA_MEM_TO_DEV) {
884 		maxburst = chan->cfg.dst_maxburst;
885 		width = chan->cfg.dst_addr_width;
886 		dev_addr = chan->cfg.dst_addr;
887 		*dev_dst = dev_addr;
888 		*dcmd |= PXA_DCMD_INCSRCADDR;
889 		if (chan->drcmr <= pdev->nr_requestors)
890 			*dcmd |= PXA_DCMD_FLOWTRG;
891 	}
892 	if (dir == DMA_MEM_TO_MEM)
893 		*dcmd |= PXA_DCMD_BURST32 | PXA_DCMD_INCTRGADDR |
894 			PXA_DCMD_INCSRCADDR;
895 
896 	dev_dbg(&chan->vc.chan.dev->device,
897 		"%s(): dev_addr=0x%x maxburst=%d width=%d  dir=%d\n",
898 		__func__, dev_addr, maxburst, width, dir);
899 
900 	if (width == DMA_SLAVE_BUSWIDTH_1_BYTE)
901 		*dcmd |= PXA_DCMD_WIDTH1;
902 	else if (width == DMA_SLAVE_BUSWIDTH_2_BYTES)
903 		*dcmd |= PXA_DCMD_WIDTH2;
904 	else if (width == DMA_SLAVE_BUSWIDTH_4_BYTES)
905 		*dcmd |= PXA_DCMD_WIDTH4;
906 
907 	if (maxburst == 8)
908 		*dcmd |= PXA_DCMD_BURST8;
909 	else if (maxburst == 16)
910 		*dcmd |= PXA_DCMD_BURST16;
911 	else if (maxburst == 32)
912 		*dcmd |= PXA_DCMD_BURST32;
913 }
914 
915 static struct dma_async_tx_descriptor *
916 pxad_prep_memcpy(struct dma_chan *dchan,
917 		 dma_addr_t dma_dst, dma_addr_t dma_src,
918 		 size_t len, unsigned long flags)
919 {
920 	struct pxad_chan *chan = to_pxad_chan(dchan);
921 	struct pxad_desc_sw *sw_desc;
922 	struct pxad_desc_hw *hw_desc;
923 	u32 dcmd;
924 	unsigned int i, nb_desc = 0;
925 	size_t copy;
926 
927 	if (!dchan || !len)
928 		return NULL;
929 
930 	dev_dbg(&chan->vc.chan.dev->device,
931 		"%s(): dma_dst=0x%lx dma_src=0x%lx len=%zu flags=%lx\n",
932 		__func__, (unsigned long)dma_dst, (unsigned long)dma_src,
933 		len, flags);
934 	pxad_get_config(chan, DMA_MEM_TO_MEM, &dcmd, NULL, NULL);
935 
936 	nb_desc = DIV_ROUND_UP(len, PDMA_MAX_DESC_BYTES);
937 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
938 	if (!sw_desc)
939 		return NULL;
940 	sw_desc->len = len;
941 
942 	if (!IS_ALIGNED(dma_src, 1 << PDMA_ALIGNMENT) ||
943 	    !IS_ALIGNED(dma_dst, 1 << PDMA_ALIGNMENT))
944 		sw_desc->misaligned = true;
945 
946 	i = 0;
947 	do {
948 		hw_desc = sw_desc->hw_desc[i++];
949 		copy = min_t(size_t, len, PDMA_MAX_DESC_BYTES);
950 		hw_desc->dcmd = dcmd | (PXA_DCMD_LENGTH & copy);
951 		hw_desc->dsadr = dma_src;
952 		hw_desc->dtadr = dma_dst;
953 		len -= copy;
954 		dma_src += copy;
955 		dma_dst += copy;
956 	} while (len);
957 	set_updater_desc(sw_desc, flags);
958 
959 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
960 }
961 
962 static struct dma_async_tx_descriptor *
963 pxad_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
964 		   unsigned int sg_len, enum dma_transfer_direction dir,
965 		   unsigned long flags, void *context)
966 {
967 	struct pxad_chan *chan = to_pxad_chan(dchan);
968 	struct pxad_desc_sw *sw_desc;
969 	size_t len, avail;
970 	struct scatterlist *sg;
971 	dma_addr_t dma;
972 	u32 dcmd, dsadr = 0, dtadr = 0;
973 	unsigned int nb_desc = 0, i, j = 0;
974 
975 	if ((sgl == NULL) || (sg_len == 0))
976 		return NULL;
977 
978 	pxad_get_config(chan, dir, &dcmd, &dsadr, &dtadr);
979 	dev_dbg(&chan->vc.chan.dev->device,
980 		"%s(): dir=%d flags=%lx\n", __func__, dir, flags);
981 
982 	for_each_sg(sgl, sg, sg_len, i)
983 		nb_desc += DIV_ROUND_UP(sg_dma_len(sg), PDMA_MAX_DESC_BYTES);
984 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
985 	if (!sw_desc)
986 		return NULL;
987 
988 	for_each_sg(sgl, sg, sg_len, i) {
989 		dma = sg_dma_address(sg);
990 		avail = sg_dma_len(sg);
991 		sw_desc->len += avail;
992 
993 		do {
994 			len = min_t(size_t, avail, PDMA_MAX_DESC_BYTES);
995 			if (dma & 0x7)
996 				sw_desc->misaligned = true;
997 
998 			sw_desc->hw_desc[j]->dcmd =
999 				dcmd | (PXA_DCMD_LENGTH & len);
1000 			sw_desc->hw_desc[j]->dsadr = dsadr ? dsadr : dma;
1001 			sw_desc->hw_desc[j++]->dtadr = dtadr ? dtadr : dma;
1002 
1003 			dma += len;
1004 			avail -= len;
1005 		} while (avail);
1006 	}
1007 	set_updater_desc(sw_desc, flags);
1008 
1009 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
1010 }
1011 
1012 static struct dma_async_tx_descriptor *
1013 pxad_prep_dma_cyclic(struct dma_chan *dchan,
1014 		     dma_addr_t buf_addr, size_t len, size_t period_len,
1015 		     enum dma_transfer_direction dir, unsigned long flags)
1016 {
1017 	struct pxad_chan *chan = to_pxad_chan(dchan);
1018 	struct pxad_desc_sw *sw_desc;
1019 	struct pxad_desc_hw **phw_desc;
1020 	dma_addr_t dma;
1021 	u32 dcmd, dsadr = 0, dtadr = 0;
1022 	unsigned int nb_desc = 0;
1023 
1024 	if (!dchan || !len || !period_len)
1025 		return NULL;
1026 	if ((dir != DMA_DEV_TO_MEM) && (dir != DMA_MEM_TO_DEV)) {
1027 		dev_err(&chan->vc.chan.dev->device,
1028 			"Unsupported direction for cyclic DMA\n");
1029 		return NULL;
1030 	}
1031 	/* the buffer length must be a multiple of period_len */
1032 	if (len % period_len != 0 || period_len > PDMA_MAX_DESC_BYTES ||
1033 	    !IS_ALIGNED(period_len, 1 << PDMA_ALIGNMENT))
1034 		return NULL;
1035 
1036 	pxad_get_config(chan, dir, &dcmd, &dsadr, &dtadr);
1037 	dcmd |= PXA_DCMD_ENDIRQEN | (PXA_DCMD_LENGTH & period_len);
1038 	dev_dbg(&chan->vc.chan.dev->device,
1039 		"%s(): buf_addr=0x%lx len=%zu period=%zu dir=%d flags=%lx\n",
1040 		__func__, (unsigned long)buf_addr, len, period_len, dir, flags);
1041 
1042 	nb_desc = DIV_ROUND_UP(period_len, PDMA_MAX_DESC_BYTES);
1043 	nb_desc *= DIV_ROUND_UP(len, period_len);
1044 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
1045 	if (!sw_desc)
1046 		return NULL;
1047 	sw_desc->cyclic = true;
1048 	sw_desc->len = len;
1049 
1050 	phw_desc = sw_desc->hw_desc;
1051 	dma = buf_addr;
1052 	do {
1053 		phw_desc[0]->dsadr = dsadr ? dsadr : dma;
1054 		phw_desc[0]->dtadr = dtadr ? dtadr : dma;
1055 		phw_desc[0]->dcmd = dcmd;
1056 		phw_desc++;
1057 		dma += period_len;
1058 		len -= period_len;
1059 	} while (len);
1060 	set_updater_desc(sw_desc, flags);
1061 
1062 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
1063 }
1064 
1065 static int pxad_config(struct dma_chan *dchan,
1066 		       struct dma_slave_config *cfg)
1067 {
1068 	struct pxad_chan *chan = to_pxad_chan(dchan);
1069 
1070 	if (!dchan)
1071 		return -EINVAL;
1072 
1073 	chan->cfg = *cfg;
1074 	return 0;
1075 }
1076 
1077 static int pxad_terminate_all(struct dma_chan *dchan)
1078 {
1079 	struct pxad_chan *chan = to_pxad_chan(dchan);
1080 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
1081 	struct virt_dma_desc *vd = NULL;
1082 	unsigned long flags;
1083 	struct pxad_phy *phy;
1084 	LIST_HEAD(head);
1085 
1086 	dev_dbg(&chan->vc.chan.dev->device,
1087 		"%s(): vchan %p: terminate all\n", __func__, &chan->vc);
1088 
1089 	spin_lock_irqsave(&chan->vc.lock, flags);
1090 	vchan_get_all_descriptors(&chan->vc, &head);
1091 
1092 	list_for_each_entry(vd, &head, node) {
1093 		dev_dbg(&chan->vc.chan.dev->device,
1094 			"%s(): cancelling txd %p[%x] (completed=%d)", __func__,
1095 			vd, vd->tx.cookie, is_desc_completed(vd));
1096 	}
1097 
1098 	phy = chan->phy;
1099 	if (phy) {
1100 		phy_disable(chan->phy);
1101 		pxad_free_phy(chan);
1102 		chan->phy = NULL;
1103 		spin_lock(&pdev->phy_lock);
1104 		phy->vchan = NULL;
1105 		spin_unlock(&pdev->phy_lock);
1106 	}
1107 	spin_unlock_irqrestore(&chan->vc.lock, flags);
1108 	vchan_dma_desc_free_list(&chan->vc, &head);
1109 
1110 	return 0;
1111 }
1112 
1113 static unsigned int pxad_residue(struct pxad_chan *chan,
1114 				 dma_cookie_t cookie)
1115 {
1116 	struct virt_dma_desc *vd = NULL;
1117 	struct pxad_desc_sw *sw_desc = NULL;
1118 	struct pxad_desc_hw *hw_desc = NULL;
1119 	u32 curr, start, len, end, residue = 0;
1120 	unsigned long flags;
1121 	bool passed = false;
1122 	int i;
1123 
1124 	/*
1125 	 * If the channel does not have a phy pointer anymore, it has already
1126 	 * been completed. Therefore, its residue is 0.
1127 	 */
1128 	if (!chan->phy)
1129 		return 0;
1130 
1131 	spin_lock_irqsave(&chan->vc.lock, flags);
1132 
1133 	vd = vchan_find_desc(&chan->vc, cookie);
1134 	if (!vd)
1135 		goto out;
1136 
1137 	sw_desc = to_pxad_sw_desc(vd);
1138 	if (sw_desc->hw_desc[0]->dcmd & PXA_DCMD_INCSRCADDR)
1139 		curr = phy_readl_relaxed(chan->phy, DSADR);
1140 	else
1141 		curr = phy_readl_relaxed(chan->phy, DTADR);
1142 
1143 	/*
1144 	 * curr has to be actually read before checking descriptor
1145 	 * completion, so that a curr inside a status updater
1146 	 * descriptor implies the following test returns true, and
1147 	 * preventing reordering of curr load and the test.
1148 	 */
1149 	rmb();
1150 	if (is_desc_completed(vd))
1151 		goto out;
1152 
1153 	for (i = 0; i < sw_desc->nb_desc - 1; i++) {
1154 		hw_desc = sw_desc->hw_desc[i];
1155 		if (sw_desc->hw_desc[0]->dcmd & PXA_DCMD_INCSRCADDR)
1156 			start = hw_desc->dsadr;
1157 		else
1158 			start = hw_desc->dtadr;
1159 		len = hw_desc->dcmd & PXA_DCMD_LENGTH;
1160 		end = start + len;
1161 
1162 		/*
1163 		 * 'passed' will be latched once we found the descriptor
1164 		 * which lies inside the boundaries of the curr
1165 		 * pointer. All descriptors that occur in the list
1166 		 * _after_ we found that partially handled descriptor
1167 		 * are still to be processed and are hence added to the
1168 		 * residual bytes counter.
1169 		 */
1170 
1171 		if (passed) {
1172 			residue += len;
1173 		} else if (curr >= start && curr <= end) {
1174 			residue += end - curr;
1175 			passed = true;
1176 		}
1177 	}
1178 	if (!passed)
1179 		residue = sw_desc->len;
1180 
1181 out:
1182 	spin_unlock_irqrestore(&chan->vc.lock, flags);
1183 	dev_dbg(&chan->vc.chan.dev->device,
1184 		"%s(): txd %p[%x] sw_desc=%p: %d\n",
1185 		__func__, vd, cookie, sw_desc, residue);
1186 	return residue;
1187 }
1188 
1189 static enum dma_status pxad_tx_status(struct dma_chan *dchan,
1190 				      dma_cookie_t cookie,
1191 				      struct dma_tx_state *txstate)
1192 {
1193 	struct pxad_chan *chan = to_pxad_chan(dchan);
1194 	enum dma_status ret;
1195 
1196 	if (cookie == chan->bus_error)
1197 		return DMA_ERROR;
1198 
1199 	ret = dma_cookie_status(dchan, cookie, txstate);
1200 	if (likely(txstate && (ret != DMA_ERROR)))
1201 		dma_set_residue(txstate, pxad_residue(chan, cookie));
1202 
1203 	return ret;
1204 }
1205 
1206 static void pxad_synchronize(struct dma_chan *dchan)
1207 {
1208 	struct pxad_chan *chan = to_pxad_chan(dchan);
1209 
1210 	wait_event(chan->wq_state, !is_chan_running(chan));
1211 	vchan_synchronize(&chan->vc);
1212 }
1213 
1214 static void pxad_free_channels(struct dma_device *dmadev)
1215 {
1216 	struct pxad_chan *c, *cn;
1217 
1218 	list_for_each_entry_safe(c, cn, &dmadev->channels,
1219 				 vc.chan.device_node) {
1220 		list_del(&c->vc.chan.device_node);
1221 		tasklet_kill(&c->vc.task);
1222 	}
1223 }
1224 
1225 static void pxad_remove(struct platform_device *op)
1226 {
1227 	struct pxad_device *pdev = platform_get_drvdata(op);
1228 
1229 	pxad_cleanup_debugfs(pdev);
1230 	pxad_free_channels(&pdev->slave);
1231 }
1232 
1233 static int pxad_init_phys(struct platform_device *op,
1234 			  struct pxad_device *pdev,
1235 			  unsigned int nb_phy_chans)
1236 {
1237 	int irq0, irq, nr_irq = 0, i, ret;
1238 	struct pxad_phy *phy;
1239 
1240 	irq0 = platform_get_irq(op, 0);
1241 	if (irq0 < 0)
1242 		return irq0;
1243 
1244 	pdev->phys = devm_kcalloc(&op->dev, nb_phy_chans,
1245 				  sizeof(pdev->phys[0]), GFP_KERNEL);
1246 	if (!pdev->phys)
1247 		return -ENOMEM;
1248 
1249 	for (i = 0; i < nb_phy_chans; i++)
1250 		if (platform_get_irq_optional(op, i) > 0)
1251 			nr_irq++;
1252 
1253 	for (i = 0; i < nb_phy_chans; i++) {
1254 		phy = &pdev->phys[i];
1255 		phy->base = pdev->base;
1256 		phy->idx = i;
1257 		irq = platform_get_irq_optional(op, i);
1258 		if ((nr_irq > 1) && (irq > 0))
1259 			ret = devm_request_irq(&op->dev, irq,
1260 					       pxad_chan_handler,
1261 					       IRQF_SHARED, "pxa-dma", phy);
1262 		if ((nr_irq == 1) && (i == 0))
1263 			ret = devm_request_irq(&op->dev, irq0,
1264 					       pxad_int_handler,
1265 					       IRQF_SHARED, "pxa-dma", pdev);
1266 		if (ret) {
1267 			dev_err(pdev->slave.dev,
1268 				"%s(): can't request irq %d:%d\n", __func__,
1269 				irq, ret);
1270 			return ret;
1271 		}
1272 	}
1273 
1274 	return 0;
1275 }
1276 
1277 static const struct of_device_id pxad_dt_ids[] = {
1278 	{ .compatible = "marvell,pdma-1.0", },
1279 	{}
1280 };
1281 MODULE_DEVICE_TABLE(of, pxad_dt_ids);
1282 
1283 static struct dma_chan *pxad_dma_xlate(struct of_phandle_args *dma_spec,
1284 					   struct of_dma *ofdma)
1285 {
1286 	struct pxad_device *d = ofdma->of_dma_data;
1287 	struct dma_chan *chan;
1288 
1289 	chan = dma_get_any_slave_channel(&d->slave);
1290 	if (!chan)
1291 		return NULL;
1292 
1293 	to_pxad_chan(chan)->drcmr = dma_spec->args[0];
1294 	to_pxad_chan(chan)->prio = dma_spec->args[1];
1295 
1296 	return chan;
1297 }
1298 
1299 static int pxad_init_dmadev(struct platform_device *op,
1300 			    struct pxad_device *pdev,
1301 			    unsigned int nr_phy_chans,
1302 			    unsigned int nr_requestors)
1303 {
1304 	int ret;
1305 	unsigned int i;
1306 	struct pxad_chan *c;
1307 
1308 	pdev->nr_chans = nr_phy_chans;
1309 	pdev->nr_requestors = nr_requestors;
1310 	INIT_LIST_HEAD(&pdev->slave.channels);
1311 	pdev->slave.device_alloc_chan_resources = pxad_alloc_chan_resources;
1312 	pdev->slave.device_free_chan_resources = pxad_free_chan_resources;
1313 	pdev->slave.device_tx_status = pxad_tx_status;
1314 	pdev->slave.device_issue_pending = pxad_issue_pending;
1315 	pdev->slave.device_config = pxad_config;
1316 	pdev->slave.device_synchronize = pxad_synchronize;
1317 	pdev->slave.device_terminate_all = pxad_terminate_all;
1318 
1319 	if (op->dev.coherent_dma_mask)
1320 		dma_set_mask(&op->dev, op->dev.coherent_dma_mask);
1321 	else
1322 		dma_set_mask(&op->dev, DMA_BIT_MASK(32));
1323 
1324 	ret = pxad_init_phys(op, pdev, nr_phy_chans);
1325 	if (ret)
1326 		return ret;
1327 
1328 	for (i = 0; i < nr_phy_chans; i++) {
1329 		c = devm_kzalloc(&op->dev, sizeof(*c), GFP_KERNEL);
1330 		if (!c)
1331 			return -ENOMEM;
1332 
1333 		c->drcmr = U32_MAX;
1334 		c->prio = PXAD_PRIO_LOWEST;
1335 		c->vc.desc_free = pxad_free_desc;
1336 		vchan_init(&c->vc, &pdev->slave);
1337 		init_waitqueue_head(&c->wq_state);
1338 	}
1339 
1340 	return dmaenginem_async_device_register(&pdev->slave);
1341 }
1342 
1343 static int pxad_probe(struct platform_device *op)
1344 {
1345 	struct pxad_device *pdev;
1346 	const struct dma_slave_map *slave_map = NULL;
1347 	struct mmp_dma_platdata *pdata = dev_get_platdata(&op->dev);
1348 	int ret, dma_channels = 0, nb_requestors = 0, slave_map_cnt = 0;
1349 	const enum dma_slave_buswidth widths =
1350 		DMA_SLAVE_BUSWIDTH_1_BYTE   | DMA_SLAVE_BUSWIDTH_2_BYTES |
1351 		DMA_SLAVE_BUSWIDTH_4_BYTES;
1352 
1353 	pdev = devm_kzalloc(&op->dev, sizeof(*pdev), GFP_KERNEL);
1354 	if (!pdev)
1355 		return -ENOMEM;
1356 
1357 	spin_lock_init(&pdev->phy_lock);
1358 
1359 	pdev->base = devm_platform_ioremap_resource(op, 0);
1360 	if (IS_ERR(pdev->base))
1361 		return PTR_ERR(pdev->base);
1362 
1363 	if (op->dev.of_node) {
1364 		/* Parse new and deprecated dma-channels properties */
1365 		if (of_property_read_u32(op->dev.of_node, "dma-channels",
1366 					 &dma_channels))
1367 			of_property_read_u32(op->dev.of_node, "#dma-channels",
1368 					     &dma_channels);
1369 		/* Parse new and deprecated dma-requests properties */
1370 		ret = of_property_read_u32(op->dev.of_node, "dma-requests",
1371 					   &nb_requestors);
1372 		if (ret)
1373 			ret = of_property_read_u32(op->dev.of_node, "#dma-requests",
1374 						   &nb_requestors);
1375 		if (ret) {
1376 			dev_warn(pdev->slave.dev,
1377 				 "#dma-requests set to default 32 as missing in OF: %d",
1378 				 ret);
1379 			nb_requestors = 32;
1380 		}
1381 	} else if (pdata && pdata->dma_channels) {
1382 		dma_channels = pdata->dma_channels;
1383 		nb_requestors = pdata->nb_requestors;
1384 		slave_map = pdata->slave_map;
1385 		slave_map_cnt = pdata->slave_map_cnt;
1386 	} else {
1387 		dma_channels = 32;	/* default 32 channel */
1388 	}
1389 
1390 	dma_cap_set(DMA_SLAVE, pdev->slave.cap_mask);
1391 	dma_cap_set(DMA_MEMCPY, pdev->slave.cap_mask);
1392 	dma_cap_set(DMA_CYCLIC, pdev->slave.cap_mask);
1393 	dma_cap_set(DMA_PRIVATE, pdev->slave.cap_mask);
1394 	pdev->slave.device_prep_dma_memcpy = pxad_prep_memcpy;
1395 	pdev->slave.device_prep_slave_sg = pxad_prep_slave_sg;
1396 	pdev->slave.device_prep_dma_cyclic = pxad_prep_dma_cyclic;
1397 	pdev->slave.filter.map = slave_map;
1398 	pdev->slave.filter.mapcnt = slave_map_cnt;
1399 	pdev->slave.filter.fn = pxad_filter_fn;
1400 
1401 	pdev->slave.copy_align = PDMA_ALIGNMENT;
1402 	pdev->slave.src_addr_widths = widths;
1403 	pdev->slave.dst_addr_widths = widths;
1404 	pdev->slave.directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
1405 	pdev->slave.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
1406 	pdev->slave.descriptor_reuse = true;
1407 
1408 	pdev->slave.dev = &op->dev;
1409 	ret = pxad_init_dmadev(op, pdev, dma_channels, nb_requestors);
1410 	if (ret) {
1411 		dev_err(pdev->slave.dev, "unable to register\n");
1412 		return ret;
1413 	}
1414 
1415 	if (op->dev.of_node) {
1416 		/* Device-tree DMA controller registration */
1417 		ret = of_dma_controller_register(op->dev.of_node,
1418 						 pxad_dma_xlate, pdev);
1419 		if (ret < 0) {
1420 			dev_err(pdev->slave.dev,
1421 				"of_dma_controller_register failed\n");
1422 			return ret;
1423 		}
1424 	}
1425 
1426 	platform_set_drvdata(op, pdev);
1427 	pxad_init_debugfs(pdev);
1428 	dev_info(pdev->slave.dev, "initialized %d channels on %d requestors\n",
1429 		 dma_channels, nb_requestors);
1430 	return 0;
1431 }
1432 
1433 static const struct platform_device_id pxad_id_table[] = {
1434 	{ "pxa-dma", },
1435 	{ },
1436 };
1437 
1438 static struct platform_driver pxad_driver = {
1439 	.driver		= {
1440 		.name	= "pxa-dma",
1441 		.of_match_table = pxad_dt_ids,
1442 	},
1443 	.id_table	= pxad_id_table,
1444 	.probe		= pxad_probe,
1445 	.remove_new	= pxad_remove,
1446 };
1447 
1448 static bool pxad_filter_fn(struct dma_chan *chan, void *param)
1449 {
1450 	struct pxad_chan *c = to_pxad_chan(chan);
1451 	struct pxad_param *p = param;
1452 
1453 	if (chan->device->dev->driver != &pxad_driver.driver)
1454 		return false;
1455 
1456 	c->drcmr = p->drcmr;
1457 	c->prio = p->prio;
1458 
1459 	return true;
1460 }
1461 
1462 module_platform_driver(pxad_driver);
1463 
1464 MODULE_DESCRIPTION("Marvell PXA Peripheral DMA Driver");
1465 MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");
1466 MODULE_LICENSE("GPL v2");
1467