xref: /linux/drivers/dma/pxa_dma.c (revision fd639726bf15fca8ee1a00dce8e0096d0ad9bd18)
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/wait.h>
25 #include <linux/dma/pxa-dma.h>
26 
27 #include "dmaengine.h"
28 #include "virt-dma.h"
29 
30 #define DCSR(n)		(0x0000 + ((n) << 2))
31 #define DALGN(n)	0x00a0
32 #define DINT		0x00f0
33 #define DDADR(n)	(0x0200 + ((n) << 4))
34 #define DSADR(n)	(0x0204 + ((n) << 4))
35 #define DTADR(n)	(0x0208 + ((n) << 4))
36 #define DCMD(n)		(0x020c + ((n) << 4))
37 
38 #define PXA_DCSR_RUN		BIT(31)	/* Run Bit (read / write) */
39 #define PXA_DCSR_NODESC		BIT(30)	/* No-Descriptor Fetch (read / write) */
40 #define PXA_DCSR_STOPIRQEN	BIT(29)	/* Stop Interrupt Enable (R/W) */
41 #define PXA_DCSR_REQPEND	BIT(8)	/* Request Pending (read-only) */
42 #define PXA_DCSR_STOPSTATE	BIT(3)	/* Stop State (read-only) */
43 #define PXA_DCSR_ENDINTR	BIT(2)	/* End Interrupt (read / write) */
44 #define PXA_DCSR_STARTINTR	BIT(1)	/* Start Interrupt (read / write) */
45 #define PXA_DCSR_BUSERR		BIT(0)	/* Bus Error Interrupt (read / write) */
46 
47 #define PXA_DCSR_EORIRQEN	BIT(28)	/* End of Receive IRQ Enable (R/W) */
48 #define PXA_DCSR_EORJMPEN	BIT(27)	/* Jump to next descriptor on EOR */
49 #define PXA_DCSR_EORSTOPEN	BIT(26)	/* STOP on an EOR */
50 #define PXA_DCSR_SETCMPST	BIT(25)	/* Set Descriptor Compare Status */
51 #define PXA_DCSR_CLRCMPST	BIT(24)	/* Clear Descriptor Compare Status */
52 #define PXA_DCSR_CMPST		BIT(10)	/* The Descriptor Compare Status */
53 #define PXA_DCSR_EORINTR	BIT(9)	/* The end of Receive */
54 
55 #define DRCMR_MAPVLD	BIT(7)	/* Map Valid (read / write) */
56 #define DRCMR_CHLNUM	0x1f	/* mask for Channel Number (read / write) */
57 
58 #define DDADR_DESCADDR	0xfffffff0	/* Address of next descriptor (mask) */
59 #define DDADR_STOP	BIT(0)	/* Stop (read / write) */
60 
61 #define PXA_DCMD_INCSRCADDR	BIT(31)	/* Source Address Increment Setting. */
62 #define PXA_DCMD_INCTRGADDR	BIT(30)	/* Target Address Increment Setting. */
63 #define PXA_DCMD_FLOWSRC	BIT(29)	/* Flow Control by the source. */
64 #define PXA_DCMD_FLOWTRG	BIT(28)	/* Flow Control by the target. */
65 #define PXA_DCMD_STARTIRQEN	BIT(22)	/* Start Interrupt Enable */
66 #define PXA_DCMD_ENDIRQEN	BIT(21)	/* End Interrupt Enable */
67 #define PXA_DCMD_ENDIAN		BIT(18)	/* Device Endian-ness. */
68 #define PXA_DCMD_BURST8		(1 << 16)	/* 8 byte burst */
69 #define PXA_DCMD_BURST16	(2 << 16)	/* 16 byte burst */
70 #define PXA_DCMD_BURST32	(3 << 16)	/* 32 byte burst */
71 #define PXA_DCMD_WIDTH1		(1 << 14)	/* 1 byte width */
72 #define PXA_DCMD_WIDTH2		(2 << 14)	/* 2 byte width (HalfWord) */
73 #define PXA_DCMD_WIDTH4		(3 << 14)	/* 4 byte width (Word) */
74 #define PXA_DCMD_LENGTH		0x01fff		/* length mask (max = 8K - 1) */
75 
76 #define PDMA_ALIGNMENT		3
77 #define PDMA_MAX_DESC_BYTES	(PXA_DCMD_LENGTH & ~((1 << PDMA_ALIGNMENT) - 1))
78 
79 struct pxad_desc_hw {
80 	u32 ddadr;	/* Points to the next descriptor + flags */
81 	u32 dsadr;	/* DSADR value for the current transfer */
82 	u32 dtadr;	/* DTADR value for the current transfer */
83 	u32 dcmd;	/* DCMD value for the current transfer */
84 } __aligned(16);
85 
86 struct pxad_desc_sw {
87 	struct virt_dma_desc	vd;		/* Virtual descriptor */
88 	int			nb_desc;	/* Number of hw. descriptors */
89 	size_t			len;		/* Number of bytes xfered */
90 	dma_addr_t		first;		/* First descriptor's addr */
91 
92 	/* At least one descriptor has an src/dst address not multiple of 8 */
93 	bool			misaligned;
94 	bool			cyclic;
95 	struct dma_pool		*desc_pool;	/* Channel's used allocator */
96 
97 	struct pxad_desc_hw	*hw_desc[];	/* DMA coherent descriptors */
98 };
99 
100 struct pxad_phy {
101 	int			idx;
102 	void __iomem		*base;
103 	struct pxad_chan	*vchan;
104 };
105 
106 struct pxad_chan {
107 	struct virt_dma_chan	vc;		/* Virtual channel */
108 	u32			drcmr;		/* Requestor of the channel */
109 	enum pxad_chan_prio	prio;		/* Required priority of phy */
110 	/*
111 	 * At least one desc_sw in submitted or issued transfers on this channel
112 	 * has one address such as: addr % 8 != 0. This implies the DALGN
113 	 * setting on the phy.
114 	 */
115 	bool			misaligned;
116 	struct dma_slave_config	cfg;		/* Runtime config */
117 
118 	/* protected by vc->lock */
119 	struct pxad_phy		*phy;
120 	struct dma_pool		*desc_pool;	/* Descriptors pool */
121 	dma_cookie_t		bus_error;
122 
123 	wait_queue_head_t	wq_state;
124 };
125 
126 struct pxad_device {
127 	struct dma_device		slave;
128 	int				nr_chans;
129 	int				nr_requestors;
130 	void __iomem			*base;
131 	struct pxad_phy			*phys;
132 	spinlock_t			phy_lock;	/* Phy association */
133 #ifdef CONFIG_DEBUG_FS
134 	struct dentry			*dbgfs_root;
135 	struct dentry			*dbgfs_state;
136 	struct dentry			**dbgfs_chan;
137 #endif
138 };
139 
140 #define tx_to_pxad_desc(tx)					\
141 	container_of(tx, struct pxad_desc_sw, async_tx)
142 #define to_pxad_chan(dchan)					\
143 	container_of(dchan, struct pxad_chan, vc.chan)
144 #define to_pxad_dev(dmadev)					\
145 	container_of(dmadev, struct pxad_device, slave)
146 #define to_pxad_sw_desc(_vd)				\
147 	container_of((_vd), struct pxad_desc_sw, vd)
148 
149 #define _phy_readl_relaxed(phy, _reg)					\
150 	readl_relaxed((phy)->base + _reg((phy)->idx))
151 #define phy_readl_relaxed(phy, _reg)					\
152 	({								\
153 		u32 _v;							\
154 		_v = readl_relaxed((phy)->base + _reg((phy)->idx));	\
155 		dev_vdbg(&phy->vchan->vc.chan.dev->device,		\
156 			 "%s(): readl(%s): 0x%08x\n", __func__, #_reg,	\
157 			  _v);						\
158 		_v;							\
159 	})
160 #define phy_writel(phy, val, _reg)					\
161 	do {								\
162 		writel((val), (phy)->base + _reg((phy)->idx));		\
163 		dev_vdbg(&phy->vchan->vc.chan.dev->device,		\
164 			 "%s(): writel(0x%08x, %s)\n",			\
165 			 __func__, (u32)(val), #_reg);			\
166 	} while (0)
167 #define phy_writel_relaxed(phy, val, _reg)				\
168 	do {								\
169 		writel_relaxed((val), (phy)->base + _reg((phy)->idx));	\
170 		dev_vdbg(&phy->vchan->vc.chan.dev->device,		\
171 			 "%s(): writel_relaxed(0x%08x, %s)\n",		\
172 			 __func__, (u32)(val), #_reg);			\
173 	} while (0)
174 
175 static unsigned int pxad_drcmr(unsigned int line)
176 {
177 	if (line < 64)
178 		return 0x100 + line * 4;
179 	return 0x1000 + line * 4;
180 }
181 
182 /*
183  * Debug fs
184  */
185 #ifdef CONFIG_DEBUG_FS
186 #include <linux/debugfs.h>
187 #include <linux/uaccess.h>
188 #include <linux/seq_file.h>
189 
190 static int dbg_show_requester_chan(struct seq_file *s, void *p)
191 {
192 	struct pxad_phy *phy = s->private;
193 	int i;
194 	u32 drcmr;
195 
196 	seq_printf(s, "DMA channel %d requester :\n", phy->idx);
197 	for (i = 0; i < 70; i++) {
198 		drcmr = readl_relaxed(phy->base + pxad_drcmr(i));
199 		if ((drcmr & DRCMR_CHLNUM) == phy->idx)
200 			seq_printf(s, "\tRequester %d (MAPVLD=%d)\n", i,
201 				   !!(drcmr & DRCMR_MAPVLD));
202 	}
203 	return 0;
204 }
205 
206 static inline int dbg_burst_from_dcmd(u32 dcmd)
207 {
208 	int burst = (dcmd >> 16) & 0x3;
209 
210 	return burst ? 4 << burst : 0;
211 }
212 
213 static int is_phys_valid(unsigned long addr)
214 {
215 	return pfn_valid(__phys_to_pfn(addr));
216 }
217 
218 #define PXA_DCSR_STR(flag) (dcsr & PXA_DCSR_##flag ? #flag" " : "")
219 #define PXA_DCMD_STR(flag) (dcmd & PXA_DCMD_##flag ? #flag" " : "")
220 
221 static int dbg_show_descriptors(struct seq_file *s, void *p)
222 {
223 	struct pxad_phy *phy = s->private;
224 	int i, max_show = 20, burst, width;
225 	u32 dcmd;
226 	unsigned long phys_desc, ddadr;
227 	struct pxad_desc_hw *desc;
228 
229 	phys_desc = ddadr = _phy_readl_relaxed(phy, DDADR);
230 
231 	seq_printf(s, "DMA channel %d descriptors :\n", phy->idx);
232 	seq_printf(s, "[%03d] First descriptor unknown\n", 0);
233 	for (i = 1; i < max_show && is_phys_valid(phys_desc); i++) {
234 		desc = phys_to_virt(phys_desc);
235 		dcmd = desc->dcmd;
236 		burst = dbg_burst_from_dcmd(dcmd);
237 		width = (1 << ((dcmd >> 14) & 0x3)) >> 1;
238 
239 		seq_printf(s, "[%03d] Desc at %08lx(virt %p)\n",
240 			   i, phys_desc, desc);
241 		seq_printf(s, "\tDDADR = %08x\n", desc->ddadr);
242 		seq_printf(s, "\tDSADR = %08x\n", desc->dsadr);
243 		seq_printf(s, "\tDTADR = %08x\n", desc->dtadr);
244 		seq_printf(s, "\tDCMD  = %08x (%s%s%s%s%s%s%sburst=%d width=%d len=%d)\n",
245 			   dcmd,
246 			   PXA_DCMD_STR(INCSRCADDR), PXA_DCMD_STR(INCTRGADDR),
247 			   PXA_DCMD_STR(FLOWSRC), PXA_DCMD_STR(FLOWTRG),
248 			   PXA_DCMD_STR(STARTIRQEN), PXA_DCMD_STR(ENDIRQEN),
249 			   PXA_DCMD_STR(ENDIAN), burst, width,
250 			   dcmd & PXA_DCMD_LENGTH);
251 		phys_desc = desc->ddadr;
252 	}
253 	if (i == max_show)
254 		seq_printf(s, "[%03d] Desc at %08lx ... max display reached\n",
255 			   i, phys_desc);
256 	else
257 		seq_printf(s, "[%03d] Desc at %08lx is %s\n",
258 			   i, phys_desc, phys_desc == DDADR_STOP ?
259 			   "DDADR_STOP" : "invalid");
260 
261 	return 0;
262 }
263 
264 static int dbg_show_chan_state(struct seq_file *s, void *p)
265 {
266 	struct pxad_phy *phy = s->private;
267 	u32 dcsr, dcmd;
268 	int burst, width;
269 	static const char * const str_prio[] = {
270 		"high", "normal", "low", "invalid"
271 	};
272 
273 	dcsr = _phy_readl_relaxed(phy, DCSR);
274 	dcmd = _phy_readl_relaxed(phy, DCMD);
275 	burst = dbg_burst_from_dcmd(dcmd);
276 	width = (1 << ((dcmd >> 14) & 0x3)) >> 1;
277 
278 	seq_printf(s, "DMA channel %d\n", phy->idx);
279 	seq_printf(s, "\tPriority : %s\n",
280 			  str_prio[(phy->idx & 0xf) / 4]);
281 	seq_printf(s, "\tUnaligned transfer bit: %s\n",
282 			  _phy_readl_relaxed(phy, DALGN) & BIT(phy->idx) ?
283 			  "yes" : "no");
284 	seq_printf(s, "\tDCSR  = %08x (%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s)\n",
285 		   dcsr, PXA_DCSR_STR(RUN), PXA_DCSR_STR(NODESC),
286 		   PXA_DCSR_STR(STOPIRQEN), PXA_DCSR_STR(EORIRQEN),
287 		   PXA_DCSR_STR(EORJMPEN), PXA_DCSR_STR(EORSTOPEN),
288 		   PXA_DCSR_STR(SETCMPST), PXA_DCSR_STR(CLRCMPST),
289 		   PXA_DCSR_STR(CMPST), PXA_DCSR_STR(EORINTR),
290 		   PXA_DCSR_STR(REQPEND), PXA_DCSR_STR(STOPSTATE),
291 		   PXA_DCSR_STR(ENDINTR), PXA_DCSR_STR(STARTINTR),
292 		   PXA_DCSR_STR(BUSERR));
293 
294 	seq_printf(s, "\tDCMD  = %08x (%s%s%s%s%s%s%sburst=%d width=%d len=%d)\n",
295 		   dcmd,
296 		   PXA_DCMD_STR(INCSRCADDR), PXA_DCMD_STR(INCTRGADDR),
297 		   PXA_DCMD_STR(FLOWSRC), PXA_DCMD_STR(FLOWTRG),
298 		   PXA_DCMD_STR(STARTIRQEN), PXA_DCMD_STR(ENDIRQEN),
299 		   PXA_DCMD_STR(ENDIAN), burst, width, dcmd & PXA_DCMD_LENGTH);
300 	seq_printf(s, "\tDSADR = %08x\n", _phy_readl_relaxed(phy, DSADR));
301 	seq_printf(s, "\tDTADR = %08x\n", _phy_readl_relaxed(phy, DTADR));
302 	seq_printf(s, "\tDDADR = %08x\n", _phy_readl_relaxed(phy, DDADR));
303 
304 	return 0;
305 }
306 
307 static int dbg_show_state(struct seq_file *s, void *p)
308 {
309 	struct pxad_device *pdev = s->private;
310 
311 	/* basic device status */
312 	seq_puts(s, "DMA engine status\n");
313 	seq_printf(s, "\tChannel number: %d\n", pdev->nr_chans);
314 
315 	return 0;
316 }
317 
318 #define DBGFS_FUNC_DECL(name) \
319 static int dbg_open_##name(struct inode *inode, struct file *file) \
320 { \
321 	return single_open(file, dbg_show_##name, inode->i_private); \
322 } \
323 static const struct file_operations dbg_fops_##name = { \
324 	.open		= dbg_open_##name, \
325 	.llseek		= seq_lseek, \
326 	.read		= seq_read, \
327 	.release	= single_release, \
328 }
329 
330 DBGFS_FUNC_DECL(state);
331 DBGFS_FUNC_DECL(chan_state);
332 DBGFS_FUNC_DECL(descriptors);
333 DBGFS_FUNC_DECL(requester_chan);
334 
335 static struct dentry *pxad_dbg_alloc_chan(struct pxad_device *pdev,
336 					     int ch, struct dentry *chandir)
337 {
338 	char chan_name[11];
339 	struct dentry *chan, *chan_state = NULL, *chan_descr = NULL;
340 	struct dentry *chan_reqs = NULL;
341 	void *dt;
342 
343 	scnprintf(chan_name, sizeof(chan_name), "%d", ch);
344 	chan = debugfs_create_dir(chan_name, chandir);
345 	dt = (void *)&pdev->phys[ch];
346 
347 	if (chan)
348 		chan_state = debugfs_create_file("state", 0400, chan, dt,
349 						 &dbg_fops_chan_state);
350 	if (chan_state)
351 		chan_descr = debugfs_create_file("descriptors", 0400, chan, dt,
352 						 &dbg_fops_descriptors);
353 	if (chan_descr)
354 		chan_reqs = debugfs_create_file("requesters", 0400, chan, dt,
355 						&dbg_fops_requester_chan);
356 	if (!chan_reqs)
357 		goto err_state;
358 
359 	return chan;
360 
361 err_state:
362 	debugfs_remove_recursive(chan);
363 	return NULL;
364 }
365 
366 static void pxad_init_debugfs(struct pxad_device *pdev)
367 {
368 	int i;
369 	struct dentry *chandir;
370 
371 	pdev->dbgfs_root = debugfs_create_dir(dev_name(pdev->slave.dev), NULL);
372 	if (IS_ERR(pdev->dbgfs_root) || !pdev->dbgfs_root)
373 		goto err_root;
374 
375 	pdev->dbgfs_state = debugfs_create_file("state", 0400, pdev->dbgfs_root,
376 						pdev, &dbg_fops_state);
377 	if (!pdev->dbgfs_state)
378 		goto err_state;
379 
380 	pdev->dbgfs_chan =
381 		kmalloc_array(pdev->nr_chans, sizeof(*pdev->dbgfs_state),
382 			      GFP_KERNEL);
383 	if (!pdev->dbgfs_chan)
384 		goto err_alloc;
385 
386 	chandir = debugfs_create_dir("channels", pdev->dbgfs_root);
387 	if (!chandir)
388 		goto err_chandir;
389 
390 	for (i = 0; i < pdev->nr_chans; i++) {
391 		pdev->dbgfs_chan[i] = pxad_dbg_alloc_chan(pdev, i, chandir);
392 		if (!pdev->dbgfs_chan[i])
393 			goto err_chans;
394 	}
395 
396 	return;
397 err_chans:
398 err_chandir:
399 	kfree(pdev->dbgfs_chan);
400 err_alloc:
401 err_state:
402 	debugfs_remove_recursive(pdev->dbgfs_root);
403 err_root:
404 	pr_err("pxad: debugfs is not available\n");
405 }
406 
407 static void pxad_cleanup_debugfs(struct pxad_device *pdev)
408 {
409 	debugfs_remove_recursive(pdev->dbgfs_root);
410 }
411 #else
412 static inline void pxad_init_debugfs(struct pxad_device *pdev) {}
413 static inline void pxad_cleanup_debugfs(struct pxad_device *pdev) {}
414 #endif
415 
416 static struct pxad_phy *lookup_phy(struct pxad_chan *pchan)
417 {
418 	int prio, i;
419 	struct pxad_device *pdev = to_pxad_dev(pchan->vc.chan.device);
420 	struct pxad_phy *phy, *found = NULL;
421 	unsigned long flags;
422 
423 	/*
424 	 * dma channel priorities
425 	 * ch 0 - 3,  16 - 19  <--> (0)
426 	 * ch 4 - 7,  20 - 23  <--> (1)
427 	 * ch 8 - 11, 24 - 27  <--> (2)
428 	 * ch 12 - 15, 28 - 31  <--> (3)
429 	 */
430 
431 	spin_lock_irqsave(&pdev->phy_lock, flags);
432 	for (prio = pchan->prio; prio >= PXAD_PRIO_HIGHEST; prio--) {
433 		for (i = 0; i < pdev->nr_chans; i++) {
434 			if (prio != (i & 0xf) >> 2)
435 				continue;
436 			phy = &pdev->phys[i];
437 			if (!phy->vchan) {
438 				phy->vchan = pchan;
439 				found = phy;
440 				goto out_unlock;
441 			}
442 		}
443 	}
444 
445 out_unlock:
446 	spin_unlock_irqrestore(&pdev->phy_lock, flags);
447 	dev_dbg(&pchan->vc.chan.dev->device,
448 		"%s(): phy=%p(%d)\n", __func__, found,
449 		found ? found->idx : -1);
450 
451 	return found;
452 }
453 
454 static void pxad_free_phy(struct pxad_chan *chan)
455 {
456 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
457 	unsigned long flags;
458 	u32 reg;
459 
460 	dev_dbg(&chan->vc.chan.dev->device,
461 		"%s(): freeing\n", __func__);
462 	if (!chan->phy)
463 		return;
464 
465 	/* clear the channel mapping in DRCMR */
466 	if (chan->drcmr <= pdev->nr_requestors) {
467 		reg = pxad_drcmr(chan->drcmr);
468 		writel_relaxed(0, chan->phy->base + reg);
469 	}
470 
471 	spin_lock_irqsave(&pdev->phy_lock, flags);
472 	chan->phy->vchan = NULL;
473 	chan->phy = NULL;
474 	spin_unlock_irqrestore(&pdev->phy_lock, flags);
475 }
476 
477 static bool is_chan_running(struct pxad_chan *chan)
478 {
479 	u32 dcsr;
480 	struct pxad_phy *phy = chan->phy;
481 
482 	if (!phy)
483 		return false;
484 	dcsr = phy_readl_relaxed(phy, DCSR);
485 	return dcsr & PXA_DCSR_RUN;
486 }
487 
488 static bool is_running_chan_misaligned(struct pxad_chan *chan)
489 {
490 	u32 dalgn;
491 
492 	BUG_ON(!chan->phy);
493 	dalgn = phy_readl_relaxed(chan->phy, DALGN);
494 	return dalgn & (BIT(chan->phy->idx));
495 }
496 
497 static void phy_enable(struct pxad_phy *phy, bool misaligned)
498 {
499 	struct pxad_device *pdev;
500 	u32 reg, dalgn;
501 
502 	if (!phy->vchan)
503 		return;
504 
505 	dev_dbg(&phy->vchan->vc.chan.dev->device,
506 		"%s(); phy=%p(%d) misaligned=%d\n", __func__,
507 		phy, phy->idx, misaligned);
508 
509 	pdev = to_pxad_dev(phy->vchan->vc.chan.device);
510 	if (phy->vchan->drcmr <= pdev->nr_requestors) {
511 		reg = pxad_drcmr(phy->vchan->drcmr);
512 		writel_relaxed(DRCMR_MAPVLD | phy->idx, phy->base + reg);
513 	}
514 
515 	dalgn = phy_readl_relaxed(phy, DALGN);
516 	if (misaligned)
517 		dalgn |= BIT(phy->idx);
518 	else
519 		dalgn &= ~BIT(phy->idx);
520 	phy_writel_relaxed(phy, dalgn, DALGN);
521 
522 	phy_writel(phy, PXA_DCSR_STOPIRQEN | PXA_DCSR_ENDINTR |
523 		   PXA_DCSR_BUSERR | PXA_DCSR_RUN, DCSR);
524 }
525 
526 static void phy_disable(struct pxad_phy *phy)
527 {
528 	u32 dcsr;
529 
530 	if (!phy)
531 		return;
532 
533 	dcsr = phy_readl_relaxed(phy, DCSR);
534 	dev_dbg(&phy->vchan->vc.chan.dev->device,
535 		"%s(): phy=%p(%d)\n", __func__, phy, phy->idx);
536 	phy_writel(phy, dcsr & ~PXA_DCSR_RUN & ~PXA_DCSR_STOPIRQEN, DCSR);
537 }
538 
539 static void pxad_launch_chan(struct pxad_chan *chan,
540 				 struct pxad_desc_sw *desc)
541 {
542 	dev_dbg(&chan->vc.chan.dev->device,
543 		"%s(): desc=%p\n", __func__, desc);
544 	if (!chan->phy) {
545 		chan->phy = lookup_phy(chan);
546 		if (!chan->phy) {
547 			dev_dbg(&chan->vc.chan.dev->device,
548 				"%s(): no free dma channel\n", __func__);
549 			return;
550 		}
551 	}
552 	chan->bus_error = 0;
553 
554 	/*
555 	 * Program the descriptor's address into the DMA controller,
556 	 * then start the DMA transaction
557 	 */
558 	phy_writel(chan->phy, desc->first, DDADR);
559 	phy_enable(chan->phy, chan->misaligned);
560 	wake_up(&chan->wq_state);
561 }
562 
563 static void set_updater_desc(struct pxad_desc_sw *sw_desc,
564 			     unsigned long flags)
565 {
566 	struct pxad_desc_hw *updater =
567 		sw_desc->hw_desc[sw_desc->nb_desc - 1];
568 	dma_addr_t dma = sw_desc->hw_desc[sw_desc->nb_desc - 2]->ddadr;
569 
570 	updater->ddadr = DDADR_STOP;
571 	updater->dsadr = dma;
572 	updater->dtadr = dma + 8;
573 	updater->dcmd = PXA_DCMD_WIDTH4 | PXA_DCMD_BURST32 |
574 		(PXA_DCMD_LENGTH & sizeof(u32));
575 	if (flags & DMA_PREP_INTERRUPT)
576 		updater->dcmd |= PXA_DCMD_ENDIRQEN;
577 	if (sw_desc->cyclic)
578 		sw_desc->hw_desc[sw_desc->nb_desc - 2]->ddadr = sw_desc->first;
579 }
580 
581 static bool is_desc_completed(struct virt_dma_desc *vd)
582 {
583 	struct pxad_desc_sw *sw_desc = to_pxad_sw_desc(vd);
584 	struct pxad_desc_hw *updater =
585 		sw_desc->hw_desc[sw_desc->nb_desc - 1];
586 
587 	return updater->dtadr != (updater->dsadr + 8);
588 }
589 
590 static void pxad_desc_chain(struct virt_dma_desc *vd1,
591 				struct virt_dma_desc *vd2)
592 {
593 	struct pxad_desc_sw *desc1 = to_pxad_sw_desc(vd1);
594 	struct pxad_desc_sw *desc2 = to_pxad_sw_desc(vd2);
595 	dma_addr_t dma_to_chain;
596 
597 	dma_to_chain = desc2->first;
598 	desc1->hw_desc[desc1->nb_desc - 1]->ddadr = dma_to_chain;
599 }
600 
601 static bool pxad_try_hotchain(struct virt_dma_chan *vc,
602 				  struct virt_dma_desc *vd)
603 {
604 	struct virt_dma_desc *vd_last_issued = NULL;
605 	struct pxad_chan *chan = to_pxad_chan(&vc->chan);
606 
607 	/*
608 	 * Attempt to hot chain the tx if the phy is still running. This is
609 	 * considered successful only if either the channel is still running
610 	 * after the chaining, or if the chained transfer is completed after
611 	 * having been hot chained.
612 	 * A change of alignment is not allowed, and forbids hotchaining.
613 	 */
614 	if (is_chan_running(chan)) {
615 		BUG_ON(list_empty(&vc->desc_issued));
616 
617 		if (!is_running_chan_misaligned(chan) &&
618 		    to_pxad_sw_desc(vd)->misaligned)
619 			return false;
620 
621 		vd_last_issued = list_entry(vc->desc_issued.prev,
622 					    struct virt_dma_desc, node);
623 		pxad_desc_chain(vd_last_issued, vd);
624 		if (is_chan_running(chan) || is_desc_completed(vd))
625 			return true;
626 	}
627 
628 	return false;
629 }
630 
631 static unsigned int clear_chan_irq(struct pxad_phy *phy)
632 {
633 	u32 dcsr;
634 	u32 dint = readl(phy->base + DINT);
635 
636 	if (!(dint & BIT(phy->idx)))
637 		return PXA_DCSR_RUN;
638 
639 	/* clear irq */
640 	dcsr = phy_readl_relaxed(phy, DCSR);
641 	phy_writel(phy, dcsr, DCSR);
642 	if ((dcsr & PXA_DCSR_BUSERR) && (phy->vchan))
643 		dev_warn(&phy->vchan->vc.chan.dev->device,
644 			 "%s(chan=%p): PXA_DCSR_BUSERR\n",
645 			 __func__, &phy->vchan);
646 
647 	return dcsr & ~PXA_DCSR_RUN;
648 }
649 
650 static irqreturn_t pxad_chan_handler(int irq, void *dev_id)
651 {
652 	struct pxad_phy *phy = dev_id;
653 	struct pxad_chan *chan = phy->vchan;
654 	struct virt_dma_desc *vd, *tmp;
655 	unsigned int dcsr;
656 	unsigned long flags;
657 	bool vd_completed;
658 	dma_cookie_t last_started = 0;
659 
660 	BUG_ON(!chan);
661 
662 	dcsr = clear_chan_irq(phy);
663 	if (dcsr & PXA_DCSR_RUN)
664 		return IRQ_NONE;
665 
666 	spin_lock_irqsave(&chan->vc.lock, flags);
667 	list_for_each_entry_safe(vd, tmp, &chan->vc.desc_issued, node) {
668 		vd_completed = is_desc_completed(vd);
669 		dev_dbg(&chan->vc.chan.dev->device,
670 			"%s(): checking txd %p[%x]: completed=%d dcsr=0x%x\n",
671 			__func__, vd, vd->tx.cookie, vd_completed,
672 			dcsr);
673 		last_started = vd->tx.cookie;
674 		if (to_pxad_sw_desc(vd)->cyclic) {
675 			vchan_cyclic_callback(vd);
676 			break;
677 		}
678 		if (vd_completed) {
679 			list_del(&vd->node);
680 			vchan_cookie_complete(vd);
681 		} else {
682 			break;
683 		}
684 	}
685 
686 	if (dcsr & PXA_DCSR_BUSERR) {
687 		chan->bus_error = last_started;
688 		phy_disable(phy);
689 	}
690 
691 	if (!chan->bus_error && dcsr & PXA_DCSR_STOPSTATE) {
692 		dev_dbg(&chan->vc.chan.dev->device,
693 		"%s(): channel stopped, submitted_empty=%d issued_empty=%d",
694 			__func__,
695 			list_empty(&chan->vc.desc_submitted),
696 			list_empty(&chan->vc.desc_issued));
697 		phy_writel_relaxed(phy, dcsr & ~PXA_DCSR_STOPIRQEN, DCSR);
698 
699 		if (list_empty(&chan->vc.desc_issued)) {
700 			chan->misaligned =
701 				!list_empty(&chan->vc.desc_submitted);
702 		} else {
703 			vd = list_first_entry(&chan->vc.desc_issued,
704 					      struct virt_dma_desc, node);
705 			pxad_launch_chan(chan, to_pxad_sw_desc(vd));
706 		}
707 	}
708 	spin_unlock_irqrestore(&chan->vc.lock, flags);
709 	wake_up(&chan->wq_state);
710 
711 	return IRQ_HANDLED;
712 }
713 
714 static irqreturn_t pxad_int_handler(int irq, void *dev_id)
715 {
716 	struct pxad_device *pdev = dev_id;
717 	struct pxad_phy *phy;
718 	u32 dint = readl(pdev->base + DINT);
719 	int i, ret = IRQ_NONE;
720 
721 	while (dint) {
722 		i = __ffs(dint);
723 		dint &= (dint - 1);
724 		phy = &pdev->phys[i];
725 		if (pxad_chan_handler(irq, phy) == IRQ_HANDLED)
726 			ret = IRQ_HANDLED;
727 	}
728 
729 	return ret;
730 }
731 
732 static int pxad_alloc_chan_resources(struct dma_chan *dchan)
733 {
734 	struct pxad_chan *chan = to_pxad_chan(dchan);
735 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
736 
737 	if (chan->desc_pool)
738 		return 1;
739 
740 	chan->desc_pool = dma_pool_create(dma_chan_name(dchan),
741 					  pdev->slave.dev,
742 					  sizeof(struct pxad_desc_hw),
743 					  __alignof__(struct pxad_desc_hw),
744 					  0);
745 	if (!chan->desc_pool) {
746 		dev_err(&chan->vc.chan.dev->device,
747 			"%s(): unable to allocate descriptor pool\n",
748 			__func__);
749 		return -ENOMEM;
750 	}
751 
752 	return 1;
753 }
754 
755 static void pxad_free_chan_resources(struct dma_chan *dchan)
756 {
757 	struct pxad_chan *chan = to_pxad_chan(dchan);
758 
759 	vchan_free_chan_resources(&chan->vc);
760 	dma_pool_destroy(chan->desc_pool);
761 	chan->desc_pool = NULL;
762 
763 }
764 
765 static void pxad_free_desc(struct virt_dma_desc *vd)
766 {
767 	int i;
768 	dma_addr_t dma;
769 	struct pxad_desc_sw *sw_desc = to_pxad_sw_desc(vd);
770 
771 	BUG_ON(sw_desc->nb_desc == 0);
772 	for (i = sw_desc->nb_desc - 1; i >= 0; i--) {
773 		if (i > 0)
774 			dma = sw_desc->hw_desc[i - 1]->ddadr;
775 		else
776 			dma = sw_desc->first;
777 		dma_pool_free(sw_desc->desc_pool,
778 			      sw_desc->hw_desc[i], dma);
779 	}
780 	sw_desc->nb_desc = 0;
781 	kfree(sw_desc);
782 }
783 
784 static struct pxad_desc_sw *
785 pxad_alloc_desc(struct pxad_chan *chan, unsigned int nb_hw_desc)
786 {
787 	struct pxad_desc_sw *sw_desc;
788 	dma_addr_t dma;
789 	int i;
790 
791 	sw_desc = kzalloc(sizeof(*sw_desc) +
792 			  nb_hw_desc * sizeof(struct pxad_desc_hw *),
793 			  GFP_NOWAIT);
794 	if (!sw_desc)
795 		return NULL;
796 	sw_desc->desc_pool = chan->desc_pool;
797 
798 	for (i = 0; i < nb_hw_desc; i++) {
799 		sw_desc->hw_desc[i] = dma_pool_alloc(sw_desc->desc_pool,
800 						     GFP_NOWAIT, &dma);
801 		if (!sw_desc->hw_desc[i]) {
802 			dev_err(&chan->vc.chan.dev->device,
803 				"%s(): Couldn't allocate the %dth hw_desc from dma_pool %p\n",
804 				__func__, i, sw_desc->desc_pool);
805 			goto err;
806 		}
807 
808 		if (i == 0)
809 			sw_desc->first = dma;
810 		else
811 			sw_desc->hw_desc[i - 1]->ddadr = dma;
812 		sw_desc->nb_desc++;
813 	}
814 
815 	return sw_desc;
816 err:
817 	pxad_free_desc(&sw_desc->vd);
818 	return NULL;
819 }
820 
821 static dma_cookie_t pxad_tx_submit(struct dma_async_tx_descriptor *tx)
822 {
823 	struct virt_dma_chan *vc = to_virt_chan(tx->chan);
824 	struct pxad_chan *chan = to_pxad_chan(&vc->chan);
825 	struct virt_dma_desc *vd_chained = NULL,
826 		*vd = container_of(tx, struct virt_dma_desc, tx);
827 	dma_cookie_t cookie;
828 	unsigned long flags;
829 
830 	set_updater_desc(to_pxad_sw_desc(vd), tx->flags);
831 
832 	spin_lock_irqsave(&vc->lock, flags);
833 	cookie = dma_cookie_assign(tx);
834 
835 	if (list_empty(&vc->desc_submitted) && pxad_try_hotchain(vc, vd)) {
836 		list_move_tail(&vd->node, &vc->desc_issued);
837 		dev_dbg(&chan->vc.chan.dev->device,
838 			"%s(): txd %p[%x]: submitted (hot linked)\n",
839 			__func__, vd, cookie);
840 		goto out;
841 	}
842 
843 	/*
844 	 * Fallback to placing the tx in the submitted queue
845 	 */
846 	if (!list_empty(&vc->desc_submitted)) {
847 		vd_chained = list_entry(vc->desc_submitted.prev,
848 					struct virt_dma_desc, node);
849 		/*
850 		 * Only chain the descriptors if no new misalignment is
851 		 * introduced. If a new misalignment is chained, let the channel
852 		 * stop, and be relaunched in misalign mode from the irq
853 		 * handler.
854 		 */
855 		if (chan->misaligned || !to_pxad_sw_desc(vd)->misaligned)
856 			pxad_desc_chain(vd_chained, vd);
857 		else
858 			vd_chained = NULL;
859 	}
860 	dev_dbg(&chan->vc.chan.dev->device,
861 		"%s(): txd %p[%x]: submitted (%s linked)\n",
862 		__func__, vd, cookie, vd_chained ? "cold" : "not");
863 	list_move_tail(&vd->node, &vc->desc_submitted);
864 	chan->misaligned |= to_pxad_sw_desc(vd)->misaligned;
865 
866 out:
867 	spin_unlock_irqrestore(&vc->lock, flags);
868 	return cookie;
869 }
870 
871 static void pxad_issue_pending(struct dma_chan *dchan)
872 {
873 	struct pxad_chan *chan = to_pxad_chan(dchan);
874 	struct virt_dma_desc *vd_first;
875 	unsigned long flags;
876 
877 	spin_lock_irqsave(&chan->vc.lock, flags);
878 	if (list_empty(&chan->vc.desc_submitted))
879 		goto out;
880 
881 	vd_first = list_first_entry(&chan->vc.desc_submitted,
882 				    struct virt_dma_desc, node);
883 	dev_dbg(&chan->vc.chan.dev->device,
884 		"%s(): txd %p[%x]", __func__, vd_first, vd_first->tx.cookie);
885 
886 	vchan_issue_pending(&chan->vc);
887 	if (!pxad_try_hotchain(&chan->vc, vd_first))
888 		pxad_launch_chan(chan, to_pxad_sw_desc(vd_first));
889 out:
890 	spin_unlock_irqrestore(&chan->vc.lock, flags);
891 }
892 
893 static inline struct dma_async_tx_descriptor *
894 pxad_tx_prep(struct virt_dma_chan *vc, struct virt_dma_desc *vd,
895 		 unsigned long tx_flags)
896 {
897 	struct dma_async_tx_descriptor *tx;
898 	struct pxad_chan *chan = container_of(vc, struct pxad_chan, vc);
899 
900 	INIT_LIST_HEAD(&vd->node);
901 	tx = vchan_tx_prep(vc, vd, tx_flags);
902 	tx->tx_submit = pxad_tx_submit;
903 	dev_dbg(&chan->vc.chan.dev->device,
904 		"%s(): vc=%p txd=%p[%x] flags=0x%lx\n", __func__,
905 		vc, vd, vd->tx.cookie,
906 		tx_flags);
907 
908 	return tx;
909 }
910 
911 static void pxad_get_config(struct pxad_chan *chan,
912 			    enum dma_transfer_direction dir,
913 			    u32 *dcmd, u32 *dev_src, u32 *dev_dst)
914 {
915 	u32 maxburst = 0, dev_addr = 0;
916 	enum dma_slave_buswidth width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
917 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
918 
919 	*dcmd = 0;
920 	if (dir == DMA_DEV_TO_MEM) {
921 		maxburst = chan->cfg.src_maxburst;
922 		width = chan->cfg.src_addr_width;
923 		dev_addr = chan->cfg.src_addr;
924 		*dev_src = dev_addr;
925 		*dcmd |= PXA_DCMD_INCTRGADDR;
926 		if (chan->drcmr <= pdev->nr_requestors)
927 			*dcmd |= PXA_DCMD_FLOWSRC;
928 	}
929 	if (dir == DMA_MEM_TO_DEV) {
930 		maxburst = chan->cfg.dst_maxburst;
931 		width = chan->cfg.dst_addr_width;
932 		dev_addr = chan->cfg.dst_addr;
933 		*dev_dst = dev_addr;
934 		*dcmd |= PXA_DCMD_INCSRCADDR;
935 		if (chan->drcmr <= pdev->nr_requestors)
936 			*dcmd |= PXA_DCMD_FLOWTRG;
937 	}
938 	if (dir == DMA_MEM_TO_MEM)
939 		*dcmd |= PXA_DCMD_BURST32 | PXA_DCMD_INCTRGADDR |
940 			PXA_DCMD_INCSRCADDR;
941 
942 	dev_dbg(&chan->vc.chan.dev->device,
943 		"%s(): dev_addr=0x%x maxburst=%d width=%d  dir=%d\n",
944 		__func__, dev_addr, maxburst, width, dir);
945 
946 	if (width == DMA_SLAVE_BUSWIDTH_1_BYTE)
947 		*dcmd |= PXA_DCMD_WIDTH1;
948 	else if (width == DMA_SLAVE_BUSWIDTH_2_BYTES)
949 		*dcmd |= PXA_DCMD_WIDTH2;
950 	else if (width == DMA_SLAVE_BUSWIDTH_4_BYTES)
951 		*dcmd |= PXA_DCMD_WIDTH4;
952 
953 	if (maxburst == 8)
954 		*dcmd |= PXA_DCMD_BURST8;
955 	else if (maxburst == 16)
956 		*dcmd |= PXA_DCMD_BURST16;
957 	else if (maxburst == 32)
958 		*dcmd |= PXA_DCMD_BURST32;
959 
960 	/* FIXME: drivers should be ported over to use the filter
961 	 * function. Once that's done, the following two lines can
962 	 * be removed.
963 	 */
964 	if (chan->cfg.slave_id)
965 		chan->drcmr = chan->cfg.slave_id;
966 }
967 
968 static struct dma_async_tx_descriptor *
969 pxad_prep_memcpy(struct dma_chan *dchan,
970 		 dma_addr_t dma_dst, dma_addr_t dma_src,
971 		 size_t len, unsigned long flags)
972 {
973 	struct pxad_chan *chan = to_pxad_chan(dchan);
974 	struct pxad_desc_sw *sw_desc;
975 	struct pxad_desc_hw *hw_desc;
976 	u32 dcmd;
977 	unsigned int i, nb_desc = 0;
978 	size_t copy;
979 
980 	if (!dchan || !len)
981 		return NULL;
982 
983 	dev_dbg(&chan->vc.chan.dev->device,
984 		"%s(): dma_dst=0x%lx dma_src=0x%lx len=%zu flags=%lx\n",
985 		__func__, (unsigned long)dma_dst, (unsigned long)dma_src,
986 		len, flags);
987 	pxad_get_config(chan, DMA_MEM_TO_MEM, &dcmd, NULL, NULL);
988 
989 	nb_desc = DIV_ROUND_UP(len, PDMA_MAX_DESC_BYTES);
990 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
991 	if (!sw_desc)
992 		return NULL;
993 	sw_desc->len = len;
994 
995 	if (!IS_ALIGNED(dma_src, 1 << PDMA_ALIGNMENT) ||
996 	    !IS_ALIGNED(dma_dst, 1 << PDMA_ALIGNMENT))
997 		sw_desc->misaligned = true;
998 
999 	i = 0;
1000 	do {
1001 		hw_desc = sw_desc->hw_desc[i++];
1002 		copy = min_t(size_t, len, PDMA_MAX_DESC_BYTES);
1003 		hw_desc->dcmd = dcmd | (PXA_DCMD_LENGTH & copy);
1004 		hw_desc->dsadr = dma_src;
1005 		hw_desc->dtadr = dma_dst;
1006 		len -= copy;
1007 		dma_src += copy;
1008 		dma_dst += copy;
1009 	} while (len);
1010 	set_updater_desc(sw_desc, flags);
1011 
1012 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
1013 }
1014 
1015 static struct dma_async_tx_descriptor *
1016 pxad_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
1017 		   unsigned int sg_len, enum dma_transfer_direction dir,
1018 		   unsigned long flags, void *context)
1019 {
1020 	struct pxad_chan *chan = to_pxad_chan(dchan);
1021 	struct pxad_desc_sw *sw_desc;
1022 	size_t len, avail;
1023 	struct scatterlist *sg;
1024 	dma_addr_t dma;
1025 	u32 dcmd, dsadr = 0, dtadr = 0;
1026 	unsigned int nb_desc = 0, i, j = 0;
1027 
1028 	if ((sgl == NULL) || (sg_len == 0))
1029 		return NULL;
1030 
1031 	pxad_get_config(chan, dir, &dcmd, &dsadr, &dtadr);
1032 	dev_dbg(&chan->vc.chan.dev->device,
1033 		"%s(): dir=%d flags=%lx\n", __func__, dir, flags);
1034 
1035 	for_each_sg(sgl, sg, sg_len, i)
1036 		nb_desc += DIV_ROUND_UP(sg_dma_len(sg), PDMA_MAX_DESC_BYTES);
1037 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
1038 	if (!sw_desc)
1039 		return NULL;
1040 
1041 	for_each_sg(sgl, sg, sg_len, i) {
1042 		dma = sg_dma_address(sg);
1043 		avail = sg_dma_len(sg);
1044 		sw_desc->len += avail;
1045 
1046 		do {
1047 			len = min_t(size_t, avail, PDMA_MAX_DESC_BYTES);
1048 			if (dma & 0x7)
1049 				sw_desc->misaligned = true;
1050 
1051 			sw_desc->hw_desc[j]->dcmd =
1052 				dcmd | (PXA_DCMD_LENGTH & len);
1053 			sw_desc->hw_desc[j]->dsadr = dsadr ? dsadr : dma;
1054 			sw_desc->hw_desc[j++]->dtadr = dtadr ? dtadr : dma;
1055 
1056 			dma += len;
1057 			avail -= len;
1058 		} while (avail);
1059 	}
1060 	set_updater_desc(sw_desc, flags);
1061 
1062 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
1063 }
1064 
1065 static struct dma_async_tx_descriptor *
1066 pxad_prep_dma_cyclic(struct dma_chan *dchan,
1067 		     dma_addr_t buf_addr, size_t len, size_t period_len,
1068 		     enum dma_transfer_direction dir, unsigned long flags)
1069 {
1070 	struct pxad_chan *chan = to_pxad_chan(dchan);
1071 	struct pxad_desc_sw *sw_desc;
1072 	struct pxad_desc_hw **phw_desc;
1073 	dma_addr_t dma;
1074 	u32 dcmd, dsadr = 0, dtadr = 0;
1075 	unsigned int nb_desc = 0;
1076 
1077 	if (!dchan || !len || !period_len)
1078 		return NULL;
1079 	if ((dir != DMA_DEV_TO_MEM) && (dir != DMA_MEM_TO_DEV)) {
1080 		dev_err(&chan->vc.chan.dev->device,
1081 			"Unsupported direction for cyclic DMA\n");
1082 		return NULL;
1083 	}
1084 	/* the buffer length must be a multiple of period_len */
1085 	if (len % period_len != 0 || period_len > PDMA_MAX_DESC_BYTES ||
1086 	    !IS_ALIGNED(period_len, 1 << PDMA_ALIGNMENT))
1087 		return NULL;
1088 
1089 	pxad_get_config(chan, dir, &dcmd, &dsadr, &dtadr);
1090 	dcmd |= PXA_DCMD_ENDIRQEN | (PXA_DCMD_LENGTH & period_len);
1091 	dev_dbg(&chan->vc.chan.dev->device,
1092 		"%s(): buf_addr=0x%lx len=%zu period=%zu dir=%d flags=%lx\n",
1093 		__func__, (unsigned long)buf_addr, len, period_len, dir, flags);
1094 
1095 	nb_desc = DIV_ROUND_UP(period_len, PDMA_MAX_DESC_BYTES);
1096 	nb_desc *= DIV_ROUND_UP(len, period_len);
1097 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
1098 	if (!sw_desc)
1099 		return NULL;
1100 	sw_desc->cyclic = true;
1101 	sw_desc->len = len;
1102 
1103 	phw_desc = sw_desc->hw_desc;
1104 	dma = buf_addr;
1105 	do {
1106 		phw_desc[0]->dsadr = dsadr ? dsadr : dma;
1107 		phw_desc[0]->dtadr = dtadr ? dtadr : dma;
1108 		phw_desc[0]->dcmd = dcmd;
1109 		phw_desc++;
1110 		dma += period_len;
1111 		len -= period_len;
1112 	} while (len);
1113 	set_updater_desc(sw_desc, flags);
1114 
1115 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
1116 }
1117 
1118 static int pxad_config(struct dma_chan *dchan,
1119 		       struct dma_slave_config *cfg)
1120 {
1121 	struct pxad_chan *chan = to_pxad_chan(dchan);
1122 
1123 	if (!dchan)
1124 		return -EINVAL;
1125 
1126 	chan->cfg = *cfg;
1127 	return 0;
1128 }
1129 
1130 static int pxad_terminate_all(struct dma_chan *dchan)
1131 {
1132 	struct pxad_chan *chan = to_pxad_chan(dchan);
1133 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
1134 	struct virt_dma_desc *vd = NULL;
1135 	unsigned long flags;
1136 	struct pxad_phy *phy;
1137 	LIST_HEAD(head);
1138 
1139 	dev_dbg(&chan->vc.chan.dev->device,
1140 		"%s(): vchan %p: terminate all\n", __func__, &chan->vc);
1141 
1142 	spin_lock_irqsave(&chan->vc.lock, flags);
1143 	vchan_get_all_descriptors(&chan->vc, &head);
1144 
1145 	list_for_each_entry(vd, &head, node) {
1146 		dev_dbg(&chan->vc.chan.dev->device,
1147 			"%s(): cancelling txd %p[%x] (completed=%d)", __func__,
1148 			vd, vd->tx.cookie, is_desc_completed(vd));
1149 	}
1150 
1151 	phy = chan->phy;
1152 	if (phy) {
1153 		phy_disable(chan->phy);
1154 		pxad_free_phy(chan);
1155 		chan->phy = NULL;
1156 		spin_lock(&pdev->phy_lock);
1157 		phy->vchan = NULL;
1158 		spin_unlock(&pdev->phy_lock);
1159 	}
1160 	spin_unlock_irqrestore(&chan->vc.lock, flags);
1161 	vchan_dma_desc_free_list(&chan->vc, &head);
1162 
1163 	return 0;
1164 }
1165 
1166 static unsigned int pxad_residue(struct pxad_chan *chan,
1167 				 dma_cookie_t cookie)
1168 {
1169 	struct virt_dma_desc *vd = NULL;
1170 	struct pxad_desc_sw *sw_desc = NULL;
1171 	struct pxad_desc_hw *hw_desc = NULL;
1172 	u32 curr, start, len, end, residue = 0;
1173 	unsigned long flags;
1174 	bool passed = false;
1175 	int i;
1176 
1177 	/*
1178 	 * If the channel does not have a phy pointer anymore, it has already
1179 	 * been completed. Therefore, its residue is 0.
1180 	 */
1181 	if (!chan->phy)
1182 		return 0;
1183 
1184 	spin_lock_irqsave(&chan->vc.lock, flags);
1185 
1186 	vd = vchan_find_desc(&chan->vc, cookie);
1187 	if (!vd)
1188 		goto out;
1189 
1190 	sw_desc = to_pxad_sw_desc(vd);
1191 	if (sw_desc->hw_desc[0]->dcmd & PXA_DCMD_INCSRCADDR)
1192 		curr = phy_readl_relaxed(chan->phy, DSADR);
1193 	else
1194 		curr = phy_readl_relaxed(chan->phy, DTADR);
1195 
1196 	/*
1197 	 * curr has to be actually read before checking descriptor
1198 	 * completion, so that a curr inside a status updater
1199 	 * descriptor implies the following test returns true, and
1200 	 * preventing reordering of curr load and the test.
1201 	 */
1202 	rmb();
1203 	if (is_desc_completed(vd))
1204 		goto out;
1205 
1206 	for (i = 0; i < sw_desc->nb_desc - 1; i++) {
1207 		hw_desc = sw_desc->hw_desc[i];
1208 		if (sw_desc->hw_desc[0]->dcmd & PXA_DCMD_INCSRCADDR)
1209 			start = hw_desc->dsadr;
1210 		else
1211 			start = hw_desc->dtadr;
1212 		len = hw_desc->dcmd & PXA_DCMD_LENGTH;
1213 		end = start + len;
1214 
1215 		/*
1216 		 * 'passed' will be latched once we found the descriptor
1217 		 * which lies inside the boundaries of the curr
1218 		 * pointer. All descriptors that occur in the list
1219 		 * _after_ we found that partially handled descriptor
1220 		 * are still to be processed and are hence added to the
1221 		 * residual bytes counter.
1222 		 */
1223 
1224 		if (passed) {
1225 			residue += len;
1226 		} else if (curr >= start && curr <= end) {
1227 			residue += end - curr;
1228 			passed = true;
1229 		}
1230 	}
1231 	if (!passed)
1232 		residue = sw_desc->len;
1233 
1234 out:
1235 	spin_unlock_irqrestore(&chan->vc.lock, flags);
1236 	dev_dbg(&chan->vc.chan.dev->device,
1237 		"%s(): txd %p[%x] sw_desc=%p: %d\n",
1238 		__func__, vd, cookie, sw_desc, residue);
1239 	return residue;
1240 }
1241 
1242 static enum dma_status pxad_tx_status(struct dma_chan *dchan,
1243 				      dma_cookie_t cookie,
1244 				      struct dma_tx_state *txstate)
1245 {
1246 	struct pxad_chan *chan = to_pxad_chan(dchan);
1247 	enum dma_status ret;
1248 
1249 	if (cookie == chan->bus_error)
1250 		return DMA_ERROR;
1251 
1252 	ret = dma_cookie_status(dchan, cookie, txstate);
1253 	if (likely(txstate && (ret != DMA_ERROR)))
1254 		dma_set_residue(txstate, pxad_residue(chan, cookie));
1255 
1256 	return ret;
1257 }
1258 
1259 static void pxad_synchronize(struct dma_chan *dchan)
1260 {
1261 	struct pxad_chan *chan = to_pxad_chan(dchan);
1262 
1263 	wait_event(chan->wq_state, !is_chan_running(chan));
1264 	vchan_synchronize(&chan->vc);
1265 }
1266 
1267 static void pxad_free_channels(struct dma_device *dmadev)
1268 {
1269 	struct pxad_chan *c, *cn;
1270 
1271 	list_for_each_entry_safe(c, cn, &dmadev->channels,
1272 				 vc.chan.device_node) {
1273 		list_del(&c->vc.chan.device_node);
1274 		tasklet_kill(&c->vc.task);
1275 	}
1276 }
1277 
1278 static int pxad_remove(struct platform_device *op)
1279 {
1280 	struct pxad_device *pdev = platform_get_drvdata(op);
1281 
1282 	pxad_cleanup_debugfs(pdev);
1283 	pxad_free_channels(&pdev->slave);
1284 	dma_async_device_unregister(&pdev->slave);
1285 	return 0;
1286 }
1287 
1288 static int pxad_init_phys(struct platform_device *op,
1289 			  struct pxad_device *pdev,
1290 			  unsigned int nb_phy_chans)
1291 {
1292 	int irq0, irq, nr_irq = 0, i, ret;
1293 	struct pxad_phy *phy;
1294 
1295 	irq0 = platform_get_irq(op, 0);
1296 	if (irq0 < 0)
1297 		return irq0;
1298 
1299 	pdev->phys = devm_kcalloc(&op->dev, nb_phy_chans,
1300 				  sizeof(pdev->phys[0]), GFP_KERNEL);
1301 	if (!pdev->phys)
1302 		return -ENOMEM;
1303 
1304 	for (i = 0; i < nb_phy_chans; i++)
1305 		if (platform_get_irq(op, i) > 0)
1306 			nr_irq++;
1307 
1308 	for (i = 0; i < nb_phy_chans; i++) {
1309 		phy = &pdev->phys[i];
1310 		phy->base = pdev->base;
1311 		phy->idx = i;
1312 		irq = platform_get_irq(op, i);
1313 		if ((nr_irq > 1) && (irq > 0))
1314 			ret = devm_request_irq(&op->dev, irq,
1315 					       pxad_chan_handler,
1316 					       IRQF_SHARED, "pxa-dma", phy);
1317 		if ((nr_irq == 1) && (i == 0))
1318 			ret = devm_request_irq(&op->dev, irq0,
1319 					       pxad_int_handler,
1320 					       IRQF_SHARED, "pxa-dma", pdev);
1321 		if (ret) {
1322 			dev_err(pdev->slave.dev,
1323 				"%s(): can't request irq %d:%d\n", __func__,
1324 				irq, ret);
1325 			return ret;
1326 		}
1327 	}
1328 
1329 	return 0;
1330 }
1331 
1332 static const struct of_device_id pxad_dt_ids[] = {
1333 	{ .compatible = "marvell,pdma-1.0", },
1334 	{}
1335 };
1336 MODULE_DEVICE_TABLE(of, pxad_dt_ids);
1337 
1338 static struct dma_chan *pxad_dma_xlate(struct of_phandle_args *dma_spec,
1339 					   struct of_dma *ofdma)
1340 {
1341 	struct pxad_device *d = ofdma->of_dma_data;
1342 	struct dma_chan *chan;
1343 
1344 	chan = dma_get_any_slave_channel(&d->slave);
1345 	if (!chan)
1346 		return NULL;
1347 
1348 	to_pxad_chan(chan)->drcmr = dma_spec->args[0];
1349 	to_pxad_chan(chan)->prio = dma_spec->args[1];
1350 
1351 	return chan;
1352 }
1353 
1354 static int pxad_init_dmadev(struct platform_device *op,
1355 			    struct pxad_device *pdev,
1356 			    unsigned int nr_phy_chans,
1357 			    unsigned int nr_requestors)
1358 {
1359 	int ret;
1360 	unsigned int i;
1361 	struct pxad_chan *c;
1362 
1363 	pdev->nr_chans = nr_phy_chans;
1364 	pdev->nr_requestors = nr_requestors;
1365 	INIT_LIST_HEAD(&pdev->slave.channels);
1366 	pdev->slave.device_alloc_chan_resources = pxad_alloc_chan_resources;
1367 	pdev->slave.device_free_chan_resources = pxad_free_chan_resources;
1368 	pdev->slave.device_tx_status = pxad_tx_status;
1369 	pdev->slave.device_issue_pending = pxad_issue_pending;
1370 	pdev->slave.device_config = pxad_config;
1371 	pdev->slave.device_synchronize = pxad_synchronize;
1372 	pdev->slave.device_terminate_all = pxad_terminate_all;
1373 
1374 	if (op->dev.coherent_dma_mask)
1375 		dma_set_mask(&op->dev, op->dev.coherent_dma_mask);
1376 	else
1377 		dma_set_mask(&op->dev, DMA_BIT_MASK(32));
1378 
1379 	ret = pxad_init_phys(op, pdev, nr_phy_chans);
1380 	if (ret)
1381 		return ret;
1382 
1383 	for (i = 0; i < nr_phy_chans; i++) {
1384 		c = devm_kzalloc(&op->dev, sizeof(*c), GFP_KERNEL);
1385 		if (!c)
1386 			return -ENOMEM;
1387 		c->vc.desc_free = pxad_free_desc;
1388 		vchan_init(&c->vc, &pdev->slave);
1389 		init_waitqueue_head(&c->wq_state);
1390 	}
1391 
1392 	return dma_async_device_register(&pdev->slave);
1393 }
1394 
1395 static int pxad_probe(struct platform_device *op)
1396 {
1397 	struct pxad_device *pdev;
1398 	const struct of_device_id *of_id;
1399 	struct mmp_dma_platdata *pdata = dev_get_platdata(&op->dev);
1400 	struct resource *iores;
1401 	int ret, dma_channels = 0, nb_requestors = 0;
1402 	const enum dma_slave_buswidth widths =
1403 		DMA_SLAVE_BUSWIDTH_1_BYTE   | DMA_SLAVE_BUSWIDTH_2_BYTES |
1404 		DMA_SLAVE_BUSWIDTH_4_BYTES;
1405 
1406 	pdev = devm_kzalloc(&op->dev, sizeof(*pdev), GFP_KERNEL);
1407 	if (!pdev)
1408 		return -ENOMEM;
1409 
1410 	spin_lock_init(&pdev->phy_lock);
1411 
1412 	iores = platform_get_resource(op, IORESOURCE_MEM, 0);
1413 	pdev->base = devm_ioremap_resource(&op->dev, iores);
1414 	if (IS_ERR(pdev->base))
1415 		return PTR_ERR(pdev->base);
1416 
1417 	of_id = of_match_device(pxad_dt_ids, &op->dev);
1418 	if (of_id) {
1419 		of_property_read_u32(op->dev.of_node, "#dma-channels",
1420 				     &dma_channels);
1421 		ret = of_property_read_u32(op->dev.of_node, "#dma-requests",
1422 					   &nb_requestors);
1423 		if (ret) {
1424 			dev_warn(pdev->slave.dev,
1425 				 "#dma-requests set to default 32 as missing in OF: %d",
1426 				 ret);
1427 			nb_requestors = 32;
1428 		};
1429 	} else if (pdata && pdata->dma_channels) {
1430 		dma_channels = pdata->dma_channels;
1431 		nb_requestors = pdata->nb_requestors;
1432 	} else {
1433 		dma_channels = 32;	/* default 32 channel */
1434 	}
1435 
1436 	dma_cap_set(DMA_SLAVE, pdev->slave.cap_mask);
1437 	dma_cap_set(DMA_MEMCPY, pdev->slave.cap_mask);
1438 	dma_cap_set(DMA_CYCLIC, pdev->slave.cap_mask);
1439 	dma_cap_set(DMA_PRIVATE, pdev->slave.cap_mask);
1440 	pdev->slave.device_prep_dma_memcpy = pxad_prep_memcpy;
1441 	pdev->slave.device_prep_slave_sg = pxad_prep_slave_sg;
1442 	pdev->slave.device_prep_dma_cyclic = pxad_prep_dma_cyclic;
1443 
1444 	pdev->slave.copy_align = PDMA_ALIGNMENT;
1445 	pdev->slave.src_addr_widths = widths;
1446 	pdev->slave.dst_addr_widths = widths;
1447 	pdev->slave.directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
1448 	pdev->slave.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
1449 	pdev->slave.descriptor_reuse = true;
1450 
1451 	pdev->slave.dev = &op->dev;
1452 	ret = pxad_init_dmadev(op, pdev, dma_channels, nb_requestors);
1453 	if (ret) {
1454 		dev_err(pdev->slave.dev, "unable to register\n");
1455 		return ret;
1456 	}
1457 
1458 	if (op->dev.of_node) {
1459 		/* Device-tree DMA controller registration */
1460 		ret = of_dma_controller_register(op->dev.of_node,
1461 						 pxad_dma_xlate, pdev);
1462 		if (ret < 0) {
1463 			dev_err(pdev->slave.dev,
1464 				"of_dma_controller_register failed\n");
1465 			return ret;
1466 		}
1467 	}
1468 
1469 	platform_set_drvdata(op, pdev);
1470 	pxad_init_debugfs(pdev);
1471 	dev_info(pdev->slave.dev, "initialized %d channels on %d requestors\n",
1472 		 dma_channels, nb_requestors);
1473 	return 0;
1474 }
1475 
1476 static const struct platform_device_id pxad_id_table[] = {
1477 	{ "pxa-dma", },
1478 	{ },
1479 };
1480 
1481 static struct platform_driver pxad_driver = {
1482 	.driver		= {
1483 		.name	= "pxa-dma",
1484 		.of_match_table = pxad_dt_ids,
1485 	},
1486 	.id_table	= pxad_id_table,
1487 	.probe		= pxad_probe,
1488 	.remove		= pxad_remove,
1489 };
1490 
1491 bool pxad_filter_fn(struct dma_chan *chan, void *param)
1492 {
1493 	struct pxad_chan *c = to_pxad_chan(chan);
1494 	struct pxad_param *p = param;
1495 
1496 	if (chan->device->dev->driver != &pxad_driver.driver)
1497 		return false;
1498 
1499 	c->drcmr = p->drcmr;
1500 	c->prio = p->prio;
1501 
1502 	return true;
1503 }
1504 EXPORT_SYMBOL_GPL(pxad_filter_fn);
1505 
1506 module_platform_driver(pxad_driver);
1507 
1508 MODULE_DESCRIPTION("Marvell PXA Peripheral DMA Driver");
1509 MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");
1510 MODULE_LICENSE("GPL v2");
1511