xref: /openbmc/linux/drivers/dma/pxa_dma.c (revision 6d99a79c)
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 bool pxad_filter_fn(struct dma_chan *chan, void *param);
183 
184 /*
185  * Debug fs
186  */
187 #ifdef CONFIG_DEBUG_FS
188 #include <linux/debugfs.h>
189 #include <linux/uaccess.h>
190 #include <linux/seq_file.h>
191 
192 static int dbg_show_requester_chan(struct seq_file *s, void *p)
193 {
194 	struct pxad_phy *phy = s->private;
195 	int i;
196 	u32 drcmr;
197 
198 	seq_printf(s, "DMA channel %d requester :\n", phy->idx);
199 	for (i = 0; i < 70; i++) {
200 		drcmr = readl_relaxed(phy->base + pxad_drcmr(i));
201 		if ((drcmr & DRCMR_CHLNUM) == phy->idx)
202 			seq_printf(s, "\tRequester %d (MAPVLD=%d)\n", i,
203 				   !!(drcmr & DRCMR_MAPVLD));
204 	}
205 	return 0;
206 }
207 
208 static inline int dbg_burst_from_dcmd(u32 dcmd)
209 {
210 	int burst = (dcmd >> 16) & 0x3;
211 
212 	return burst ? 4 << burst : 0;
213 }
214 
215 static int is_phys_valid(unsigned long addr)
216 {
217 	return pfn_valid(__phys_to_pfn(addr));
218 }
219 
220 #define PXA_DCSR_STR(flag) (dcsr & PXA_DCSR_##flag ? #flag" " : "")
221 #define PXA_DCMD_STR(flag) (dcmd & PXA_DCMD_##flag ? #flag" " : "")
222 
223 static int dbg_show_descriptors(struct seq_file *s, void *p)
224 {
225 	struct pxad_phy *phy = s->private;
226 	int i, max_show = 20, burst, width;
227 	u32 dcmd;
228 	unsigned long phys_desc, ddadr;
229 	struct pxad_desc_hw *desc;
230 
231 	phys_desc = ddadr = _phy_readl_relaxed(phy, DDADR);
232 
233 	seq_printf(s, "DMA channel %d descriptors :\n", phy->idx);
234 	seq_printf(s, "[%03d] First descriptor unknown\n", 0);
235 	for (i = 1; i < max_show && is_phys_valid(phys_desc); i++) {
236 		desc = phys_to_virt(phys_desc);
237 		dcmd = desc->dcmd;
238 		burst = dbg_burst_from_dcmd(dcmd);
239 		width = (1 << ((dcmd >> 14) & 0x3)) >> 1;
240 
241 		seq_printf(s, "[%03d] Desc at %08lx(virt %p)\n",
242 			   i, phys_desc, desc);
243 		seq_printf(s, "\tDDADR = %08x\n", desc->ddadr);
244 		seq_printf(s, "\tDSADR = %08x\n", desc->dsadr);
245 		seq_printf(s, "\tDTADR = %08x\n", desc->dtadr);
246 		seq_printf(s, "\tDCMD  = %08x (%s%s%s%s%s%s%sburst=%d width=%d len=%d)\n",
247 			   dcmd,
248 			   PXA_DCMD_STR(INCSRCADDR), PXA_DCMD_STR(INCTRGADDR),
249 			   PXA_DCMD_STR(FLOWSRC), PXA_DCMD_STR(FLOWTRG),
250 			   PXA_DCMD_STR(STARTIRQEN), PXA_DCMD_STR(ENDIRQEN),
251 			   PXA_DCMD_STR(ENDIAN), burst, width,
252 			   dcmd & PXA_DCMD_LENGTH);
253 		phys_desc = desc->ddadr;
254 	}
255 	if (i == max_show)
256 		seq_printf(s, "[%03d] Desc at %08lx ... max display reached\n",
257 			   i, phys_desc);
258 	else
259 		seq_printf(s, "[%03d] Desc at %08lx is %s\n",
260 			   i, phys_desc, phys_desc == DDADR_STOP ?
261 			   "DDADR_STOP" : "invalid");
262 
263 	return 0;
264 }
265 
266 static int dbg_show_chan_state(struct seq_file *s, void *p)
267 {
268 	struct pxad_phy *phy = s->private;
269 	u32 dcsr, dcmd;
270 	int burst, width;
271 	static const char * const str_prio[] = {
272 		"high", "normal", "low", "invalid"
273 	};
274 
275 	dcsr = _phy_readl_relaxed(phy, DCSR);
276 	dcmd = _phy_readl_relaxed(phy, DCMD);
277 	burst = dbg_burst_from_dcmd(dcmd);
278 	width = (1 << ((dcmd >> 14) & 0x3)) >> 1;
279 
280 	seq_printf(s, "DMA channel %d\n", phy->idx);
281 	seq_printf(s, "\tPriority : %s\n",
282 			  str_prio[(phy->idx & 0xf) / 4]);
283 	seq_printf(s, "\tUnaligned transfer bit: %s\n",
284 			  _phy_readl_relaxed(phy, DALGN) & BIT(phy->idx) ?
285 			  "yes" : "no");
286 	seq_printf(s, "\tDCSR  = %08x (%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s)\n",
287 		   dcsr, PXA_DCSR_STR(RUN), PXA_DCSR_STR(NODESC),
288 		   PXA_DCSR_STR(STOPIRQEN), PXA_DCSR_STR(EORIRQEN),
289 		   PXA_DCSR_STR(EORJMPEN), PXA_DCSR_STR(EORSTOPEN),
290 		   PXA_DCSR_STR(SETCMPST), PXA_DCSR_STR(CLRCMPST),
291 		   PXA_DCSR_STR(CMPST), PXA_DCSR_STR(EORINTR),
292 		   PXA_DCSR_STR(REQPEND), PXA_DCSR_STR(STOPSTATE),
293 		   PXA_DCSR_STR(ENDINTR), PXA_DCSR_STR(STARTINTR),
294 		   PXA_DCSR_STR(BUSERR));
295 
296 	seq_printf(s, "\tDCMD  = %08x (%s%s%s%s%s%s%sburst=%d width=%d len=%d)\n",
297 		   dcmd,
298 		   PXA_DCMD_STR(INCSRCADDR), PXA_DCMD_STR(INCTRGADDR),
299 		   PXA_DCMD_STR(FLOWSRC), PXA_DCMD_STR(FLOWTRG),
300 		   PXA_DCMD_STR(STARTIRQEN), PXA_DCMD_STR(ENDIRQEN),
301 		   PXA_DCMD_STR(ENDIAN), burst, width, dcmd & PXA_DCMD_LENGTH);
302 	seq_printf(s, "\tDSADR = %08x\n", _phy_readl_relaxed(phy, DSADR));
303 	seq_printf(s, "\tDTADR = %08x\n", _phy_readl_relaxed(phy, DTADR));
304 	seq_printf(s, "\tDDADR = %08x\n", _phy_readl_relaxed(phy, DDADR));
305 
306 	return 0;
307 }
308 
309 static int dbg_show_state(struct seq_file *s, void *p)
310 {
311 	struct pxad_device *pdev = s->private;
312 
313 	/* basic device status */
314 	seq_puts(s, "DMA engine status\n");
315 	seq_printf(s, "\tChannel number: %d\n", pdev->nr_chans);
316 
317 	return 0;
318 }
319 
320 #define DBGFS_FUNC_DECL(name) \
321 static int dbg_open_##name(struct inode *inode, struct file *file) \
322 { \
323 	return single_open(file, dbg_show_##name, inode->i_private); \
324 } \
325 static const struct file_operations dbg_fops_##name = { \
326 	.open		= dbg_open_##name, \
327 	.llseek		= seq_lseek, \
328 	.read		= seq_read, \
329 	.release	= single_release, \
330 }
331 
332 DBGFS_FUNC_DECL(state);
333 DBGFS_FUNC_DECL(chan_state);
334 DBGFS_FUNC_DECL(descriptors);
335 DBGFS_FUNC_DECL(requester_chan);
336 
337 static struct dentry *pxad_dbg_alloc_chan(struct pxad_device *pdev,
338 					     int ch, struct dentry *chandir)
339 {
340 	char chan_name[11];
341 	struct dentry *chan, *chan_state = NULL, *chan_descr = NULL;
342 	struct dentry *chan_reqs = NULL;
343 	void *dt;
344 
345 	scnprintf(chan_name, sizeof(chan_name), "%d", ch);
346 	chan = debugfs_create_dir(chan_name, chandir);
347 	dt = (void *)&pdev->phys[ch];
348 
349 	if (chan)
350 		chan_state = debugfs_create_file("state", 0400, chan, dt,
351 						 &dbg_fops_chan_state);
352 	if (chan_state)
353 		chan_descr = debugfs_create_file("descriptors", 0400, chan, dt,
354 						 &dbg_fops_descriptors);
355 	if (chan_descr)
356 		chan_reqs = debugfs_create_file("requesters", 0400, chan, dt,
357 						&dbg_fops_requester_chan);
358 	if (!chan_reqs)
359 		goto err_state;
360 
361 	return chan;
362 
363 err_state:
364 	debugfs_remove_recursive(chan);
365 	return NULL;
366 }
367 
368 static void pxad_init_debugfs(struct pxad_device *pdev)
369 {
370 	int i;
371 	struct dentry *chandir;
372 
373 	pdev->dbgfs_root = debugfs_create_dir(dev_name(pdev->slave.dev), NULL);
374 	if (IS_ERR(pdev->dbgfs_root) || !pdev->dbgfs_root)
375 		goto err_root;
376 
377 	pdev->dbgfs_state = debugfs_create_file("state", 0400, pdev->dbgfs_root,
378 						pdev, &dbg_fops_state);
379 	if (!pdev->dbgfs_state)
380 		goto err_state;
381 
382 	pdev->dbgfs_chan =
383 		kmalloc_array(pdev->nr_chans, sizeof(*pdev->dbgfs_state),
384 			      GFP_KERNEL);
385 	if (!pdev->dbgfs_chan)
386 		goto err_alloc;
387 
388 	chandir = debugfs_create_dir("channels", pdev->dbgfs_root);
389 	if (!chandir)
390 		goto err_chandir;
391 
392 	for (i = 0; i < pdev->nr_chans; i++) {
393 		pdev->dbgfs_chan[i] = pxad_dbg_alloc_chan(pdev, i, chandir);
394 		if (!pdev->dbgfs_chan[i])
395 			goto err_chans;
396 	}
397 
398 	return;
399 err_chans:
400 err_chandir:
401 	kfree(pdev->dbgfs_chan);
402 err_alloc:
403 err_state:
404 	debugfs_remove_recursive(pdev->dbgfs_root);
405 err_root:
406 	pr_err("pxad: debugfs is not available\n");
407 }
408 
409 static void pxad_cleanup_debugfs(struct pxad_device *pdev)
410 {
411 	debugfs_remove_recursive(pdev->dbgfs_root);
412 }
413 #else
414 static inline void pxad_init_debugfs(struct pxad_device *pdev) {}
415 static inline void pxad_cleanup_debugfs(struct pxad_device *pdev) {}
416 #endif
417 
418 static struct pxad_phy *lookup_phy(struct pxad_chan *pchan)
419 {
420 	int prio, i;
421 	struct pxad_device *pdev = to_pxad_dev(pchan->vc.chan.device);
422 	struct pxad_phy *phy, *found = NULL;
423 	unsigned long flags;
424 
425 	/*
426 	 * dma channel priorities
427 	 * ch 0 - 3,  16 - 19  <--> (0)
428 	 * ch 4 - 7,  20 - 23  <--> (1)
429 	 * ch 8 - 11, 24 - 27  <--> (2)
430 	 * ch 12 - 15, 28 - 31  <--> (3)
431 	 */
432 
433 	spin_lock_irqsave(&pdev->phy_lock, flags);
434 	for (prio = pchan->prio; prio >= PXAD_PRIO_HIGHEST; prio--) {
435 		for (i = 0; i < pdev->nr_chans; i++) {
436 			if (prio != (i & 0xf) >> 2)
437 				continue;
438 			phy = &pdev->phys[i];
439 			if (!phy->vchan) {
440 				phy->vchan = pchan;
441 				found = phy;
442 				goto out_unlock;
443 			}
444 		}
445 	}
446 
447 out_unlock:
448 	spin_unlock_irqrestore(&pdev->phy_lock, flags);
449 	dev_dbg(&pchan->vc.chan.dev->device,
450 		"%s(): phy=%p(%d)\n", __func__, found,
451 		found ? found->idx : -1);
452 
453 	return found;
454 }
455 
456 static void pxad_free_phy(struct pxad_chan *chan)
457 {
458 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
459 	unsigned long flags;
460 	u32 reg;
461 
462 	dev_dbg(&chan->vc.chan.dev->device,
463 		"%s(): freeing\n", __func__);
464 	if (!chan->phy)
465 		return;
466 
467 	/* clear the channel mapping in DRCMR */
468 	if (chan->drcmr <= pdev->nr_requestors) {
469 		reg = pxad_drcmr(chan->drcmr);
470 		writel_relaxed(0, chan->phy->base + reg);
471 	}
472 
473 	spin_lock_irqsave(&pdev->phy_lock, flags);
474 	chan->phy->vchan = NULL;
475 	chan->phy = NULL;
476 	spin_unlock_irqrestore(&pdev->phy_lock, flags);
477 }
478 
479 static bool is_chan_running(struct pxad_chan *chan)
480 {
481 	u32 dcsr;
482 	struct pxad_phy *phy = chan->phy;
483 
484 	if (!phy)
485 		return false;
486 	dcsr = phy_readl_relaxed(phy, DCSR);
487 	return dcsr & PXA_DCSR_RUN;
488 }
489 
490 static bool is_running_chan_misaligned(struct pxad_chan *chan)
491 {
492 	u32 dalgn;
493 
494 	BUG_ON(!chan->phy);
495 	dalgn = phy_readl_relaxed(chan->phy, DALGN);
496 	return dalgn & (BIT(chan->phy->idx));
497 }
498 
499 static void phy_enable(struct pxad_phy *phy, bool misaligned)
500 {
501 	struct pxad_device *pdev;
502 	u32 reg, dalgn;
503 
504 	if (!phy->vchan)
505 		return;
506 
507 	dev_dbg(&phy->vchan->vc.chan.dev->device,
508 		"%s(); phy=%p(%d) misaligned=%d\n", __func__,
509 		phy, phy->idx, misaligned);
510 
511 	pdev = to_pxad_dev(phy->vchan->vc.chan.device);
512 	if (phy->vchan->drcmr <= pdev->nr_requestors) {
513 		reg = pxad_drcmr(phy->vchan->drcmr);
514 		writel_relaxed(DRCMR_MAPVLD | phy->idx, phy->base + reg);
515 	}
516 
517 	dalgn = phy_readl_relaxed(phy, DALGN);
518 	if (misaligned)
519 		dalgn |= BIT(phy->idx);
520 	else
521 		dalgn &= ~BIT(phy->idx);
522 	phy_writel_relaxed(phy, dalgn, DALGN);
523 
524 	phy_writel(phy, PXA_DCSR_STOPIRQEN | PXA_DCSR_ENDINTR |
525 		   PXA_DCSR_BUSERR | PXA_DCSR_RUN, DCSR);
526 }
527 
528 static void phy_disable(struct pxad_phy *phy)
529 {
530 	u32 dcsr;
531 
532 	if (!phy)
533 		return;
534 
535 	dcsr = phy_readl_relaxed(phy, DCSR);
536 	dev_dbg(&phy->vchan->vc.chan.dev->device,
537 		"%s(): phy=%p(%d)\n", __func__, phy, phy->idx);
538 	phy_writel(phy, dcsr & ~PXA_DCSR_RUN & ~PXA_DCSR_STOPIRQEN, DCSR);
539 }
540 
541 static void pxad_launch_chan(struct pxad_chan *chan,
542 				 struct pxad_desc_sw *desc)
543 {
544 	dev_dbg(&chan->vc.chan.dev->device,
545 		"%s(): desc=%p\n", __func__, desc);
546 	if (!chan->phy) {
547 		chan->phy = lookup_phy(chan);
548 		if (!chan->phy) {
549 			dev_dbg(&chan->vc.chan.dev->device,
550 				"%s(): no free dma channel\n", __func__);
551 			return;
552 		}
553 	}
554 	chan->bus_error = 0;
555 
556 	/*
557 	 * Program the descriptor's address into the DMA controller,
558 	 * then start the DMA transaction
559 	 */
560 	phy_writel(chan->phy, desc->first, DDADR);
561 	phy_enable(chan->phy, chan->misaligned);
562 	wake_up(&chan->wq_state);
563 }
564 
565 static void set_updater_desc(struct pxad_desc_sw *sw_desc,
566 			     unsigned long flags)
567 {
568 	struct pxad_desc_hw *updater =
569 		sw_desc->hw_desc[sw_desc->nb_desc - 1];
570 	dma_addr_t dma = sw_desc->hw_desc[sw_desc->nb_desc - 2]->ddadr;
571 
572 	updater->ddadr = DDADR_STOP;
573 	updater->dsadr = dma;
574 	updater->dtadr = dma + 8;
575 	updater->dcmd = PXA_DCMD_WIDTH4 | PXA_DCMD_BURST32 |
576 		(PXA_DCMD_LENGTH & sizeof(u32));
577 	if (flags & DMA_PREP_INTERRUPT)
578 		updater->dcmd |= PXA_DCMD_ENDIRQEN;
579 	if (sw_desc->cyclic)
580 		sw_desc->hw_desc[sw_desc->nb_desc - 2]->ddadr = sw_desc->first;
581 }
582 
583 static bool is_desc_completed(struct virt_dma_desc *vd)
584 {
585 	struct pxad_desc_sw *sw_desc = to_pxad_sw_desc(vd);
586 	struct pxad_desc_hw *updater =
587 		sw_desc->hw_desc[sw_desc->nb_desc - 1];
588 
589 	return updater->dtadr != (updater->dsadr + 8);
590 }
591 
592 static void pxad_desc_chain(struct virt_dma_desc *vd1,
593 				struct virt_dma_desc *vd2)
594 {
595 	struct pxad_desc_sw *desc1 = to_pxad_sw_desc(vd1);
596 	struct pxad_desc_sw *desc2 = to_pxad_sw_desc(vd2);
597 	dma_addr_t dma_to_chain;
598 
599 	dma_to_chain = desc2->first;
600 	desc1->hw_desc[desc1->nb_desc - 1]->ddadr = dma_to_chain;
601 }
602 
603 static bool pxad_try_hotchain(struct virt_dma_chan *vc,
604 				  struct virt_dma_desc *vd)
605 {
606 	struct virt_dma_desc *vd_last_issued = NULL;
607 	struct pxad_chan *chan = to_pxad_chan(&vc->chan);
608 
609 	/*
610 	 * Attempt to hot chain the tx if the phy is still running. This is
611 	 * considered successful only if either the channel is still running
612 	 * after the chaining, or if the chained transfer is completed after
613 	 * having been hot chained.
614 	 * A change of alignment is not allowed, and forbids hotchaining.
615 	 */
616 	if (is_chan_running(chan)) {
617 		BUG_ON(list_empty(&vc->desc_issued));
618 
619 		if (!is_running_chan_misaligned(chan) &&
620 		    to_pxad_sw_desc(vd)->misaligned)
621 			return false;
622 
623 		vd_last_issued = list_entry(vc->desc_issued.prev,
624 					    struct virt_dma_desc, node);
625 		pxad_desc_chain(vd_last_issued, vd);
626 		if (is_chan_running(chan) || is_desc_completed(vd))
627 			return true;
628 	}
629 
630 	return false;
631 }
632 
633 static unsigned int clear_chan_irq(struct pxad_phy *phy)
634 {
635 	u32 dcsr;
636 	u32 dint = readl(phy->base + DINT);
637 
638 	if (!(dint & BIT(phy->idx)))
639 		return PXA_DCSR_RUN;
640 
641 	/* clear irq */
642 	dcsr = phy_readl_relaxed(phy, DCSR);
643 	phy_writel(phy, dcsr, DCSR);
644 	if ((dcsr & PXA_DCSR_BUSERR) && (phy->vchan))
645 		dev_warn(&phy->vchan->vc.chan.dev->device,
646 			 "%s(chan=%p): PXA_DCSR_BUSERR\n",
647 			 __func__, &phy->vchan);
648 
649 	return dcsr & ~PXA_DCSR_RUN;
650 }
651 
652 static irqreturn_t pxad_chan_handler(int irq, void *dev_id)
653 {
654 	struct pxad_phy *phy = dev_id;
655 	struct pxad_chan *chan = phy->vchan;
656 	struct virt_dma_desc *vd, *tmp;
657 	unsigned int dcsr;
658 	unsigned long flags;
659 	bool vd_completed;
660 	dma_cookie_t last_started = 0;
661 
662 	BUG_ON(!chan);
663 
664 	dcsr = clear_chan_irq(phy);
665 	if (dcsr & PXA_DCSR_RUN)
666 		return IRQ_NONE;
667 
668 	spin_lock_irqsave(&chan->vc.lock, flags);
669 	list_for_each_entry_safe(vd, tmp, &chan->vc.desc_issued, node) {
670 		vd_completed = is_desc_completed(vd);
671 		dev_dbg(&chan->vc.chan.dev->device,
672 			"%s(): checking txd %p[%x]: completed=%d dcsr=0x%x\n",
673 			__func__, vd, vd->tx.cookie, vd_completed,
674 			dcsr);
675 		last_started = vd->tx.cookie;
676 		if (to_pxad_sw_desc(vd)->cyclic) {
677 			vchan_cyclic_callback(vd);
678 			break;
679 		}
680 		if (vd_completed) {
681 			list_del(&vd->node);
682 			vchan_cookie_complete(vd);
683 		} else {
684 			break;
685 		}
686 	}
687 
688 	if (dcsr & PXA_DCSR_BUSERR) {
689 		chan->bus_error = last_started;
690 		phy_disable(phy);
691 	}
692 
693 	if (!chan->bus_error && dcsr & PXA_DCSR_STOPSTATE) {
694 		dev_dbg(&chan->vc.chan.dev->device,
695 		"%s(): channel stopped, submitted_empty=%d issued_empty=%d",
696 			__func__,
697 			list_empty(&chan->vc.desc_submitted),
698 			list_empty(&chan->vc.desc_issued));
699 		phy_writel_relaxed(phy, dcsr & ~PXA_DCSR_STOPIRQEN, DCSR);
700 
701 		if (list_empty(&chan->vc.desc_issued)) {
702 			chan->misaligned =
703 				!list_empty(&chan->vc.desc_submitted);
704 		} else {
705 			vd = list_first_entry(&chan->vc.desc_issued,
706 					      struct virt_dma_desc, node);
707 			pxad_launch_chan(chan, to_pxad_sw_desc(vd));
708 		}
709 	}
710 	spin_unlock_irqrestore(&chan->vc.lock, flags);
711 	wake_up(&chan->wq_state);
712 
713 	return IRQ_HANDLED;
714 }
715 
716 static irqreturn_t pxad_int_handler(int irq, void *dev_id)
717 {
718 	struct pxad_device *pdev = dev_id;
719 	struct pxad_phy *phy;
720 	u32 dint = readl(pdev->base + DINT);
721 	int i, ret = IRQ_NONE;
722 
723 	while (dint) {
724 		i = __ffs(dint);
725 		dint &= (dint - 1);
726 		phy = &pdev->phys[i];
727 		if (pxad_chan_handler(irq, phy) == IRQ_HANDLED)
728 			ret = IRQ_HANDLED;
729 	}
730 
731 	return ret;
732 }
733 
734 static int pxad_alloc_chan_resources(struct dma_chan *dchan)
735 {
736 	struct pxad_chan *chan = to_pxad_chan(dchan);
737 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
738 
739 	if (chan->desc_pool)
740 		return 1;
741 
742 	chan->desc_pool = dma_pool_create(dma_chan_name(dchan),
743 					  pdev->slave.dev,
744 					  sizeof(struct pxad_desc_hw),
745 					  __alignof__(struct pxad_desc_hw),
746 					  0);
747 	if (!chan->desc_pool) {
748 		dev_err(&chan->vc.chan.dev->device,
749 			"%s(): unable to allocate descriptor pool\n",
750 			__func__);
751 		return -ENOMEM;
752 	}
753 
754 	return 1;
755 }
756 
757 static void pxad_free_chan_resources(struct dma_chan *dchan)
758 {
759 	struct pxad_chan *chan = to_pxad_chan(dchan);
760 
761 	vchan_free_chan_resources(&chan->vc);
762 	dma_pool_destroy(chan->desc_pool);
763 	chan->desc_pool = NULL;
764 
765 	chan->drcmr = U32_MAX;
766 	chan->prio = PXAD_PRIO_LOWEST;
767 }
768 
769 static void pxad_free_desc(struct virt_dma_desc *vd)
770 {
771 	int i;
772 	dma_addr_t dma;
773 	struct pxad_desc_sw *sw_desc = to_pxad_sw_desc(vd);
774 
775 	BUG_ON(sw_desc->nb_desc == 0);
776 	for (i = sw_desc->nb_desc - 1; i >= 0; i--) {
777 		if (i > 0)
778 			dma = sw_desc->hw_desc[i - 1]->ddadr;
779 		else
780 			dma = sw_desc->first;
781 		dma_pool_free(sw_desc->desc_pool,
782 			      sw_desc->hw_desc[i], dma);
783 	}
784 	sw_desc->nb_desc = 0;
785 	kfree(sw_desc);
786 }
787 
788 static struct pxad_desc_sw *
789 pxad_alloc_desc(struct pxad_chan *chan, unsigned int nb_hw_desc)
790 {
791 	struct pxad_desc_sw *sw_desc;
792 	dma_addr_t dma;
793 	int i;
794 
795 	sw_desc = kzalloc(sizeof(*sw_desc) +
796 			  nb_hw_desc * sizeof(struct pxad_desc_hw *),
797 			  GFP_NOWAIT);
798 	if (!sw_desc)
799 		return NULL;
800 	sw_desc->desc_pool = chan->desc_pool;
801 
802 	for (i = 0; i < nb_hw_desc; i++) {
803 		sw_desc->hw_desc[i] = dma_pool_alloc(sw_desc->desc_pool,
804 						     GFP_NOWAIT, &dma);
805 		if (!sw_desc->hw_desc[i]) {
806 			dev_err(&chan->vc.chan.dev->device,
807 				"%s(): Couldn't allocate the %dth hw_desc from dma_pool %p\n",
808 				__func__, i, sw_desc->desc_pool);
809 			goto err;
810 		}
811 
812 		if (i == 0)
813 			sw_desc->first = dma;
814 		else
815 			sw_desc->hw_desc[i - 1]->ddadr = dma;
816 		sw_desc->nb_desc++;
817 	}
818 
819 	return sw_desc;
820 err:
821 	pxad_free_desc(&sw_desc->vd);
822 	return NULL;
823 }
824 
825 static dma_cookie_t pxad_tx_submit(struct dma_async_tx_descriptor *tx)
826 {
827 	struct virt_dma_chan *vc = to_virt_chan(tx->chan);
828 	struct pxad_chan *chan = to_pxad_chan(&vc->chan);
829 	struct virt_dma_desc *vd_chained = NULL,
830 		*vd = container_of(tx, struct virt_dma_desc, tx);
831 	dma_cookie_t cookie;
832 	unsigned long flags;
833 
834 	set_updater_desc(to_pxad_sw_desc(vd), tx->flags);
835 
836 	spin_lock_irqsave(&vc->lock, flags);
837 	cookie = dma_cookie_assign(tx);
838 
839 	if (list_empty(&vc->desc_submitted) && pxad_try_hotchain(vc, vd)) {
840 		list_move_tail(&vd->node, &vc->desc_issued);
841 		dev_dbg(&chan->vc.chan.dev->device,
842 			"%s(): txd %p[%x]: submitted (hot linked)\n",
843 			__func__, vd, cookie);
844 		goto out;
845 	}
846 
847 	/*
848 	 * Fallback to placing the tx in the submitted queue
849 	 */
850 	if (!list_empty(&vc->desc_submitted)) {
851 		vd_chained = list_entry(vc->desc_submitted.prev,
852 					struct virt_dma_desc, node);
853 		/*
854 		 * Only chain the descriptors if no new misalignment is
855 		 * introduced. If a new misalignment is chained, let the channel
856 		 * stop, and be relaunched in misalign mode from the irq
857 		 * handler.
858 		 */
859 		if (chan->misaligned || !to_pxad_sw_desc(vd)->misaligned)
860 			pxad_desc_chain(vd_chained, vd);
861 		else
862 			vd_chained = NULL;
863 	}
864 	dev_dbg(&chan->vc.chan.dev->device,
865 		"%s(): txd %p[%x]: submitted (%s linked)\n",
866 		__func__, vd, cookie, vd_chained ? "cold" : "not");
867 	list_move_tail(&vd->node, &vc->desc_submitted);
868 	chan->misaligned |= to_pxad_sw_desc(vd)->misaligned;
869 
870 out:
871 	spin_unlock_irqrestore(&vc->lock, flags);
872 	return cookie;
873 }
874 
875 static void pxad_issue_pending(struct dma_chan *dchan)
876 {
877 	struct pxad_chan *chan = to_pxad_chan(dchan);
878 	struct virt_dma_desc *vd_first;
879 	unsigned long flags;
880 
881 	spin_lock_irqsave(&chan->vc.lock, flags);
882 	if (list_empty(&chan->vc.desc_submitted))
883 		goto out;
884 
885 	vd_first = list_first_entry(&chan->vc.desc_submitted,
886 				    struct virt_dma_desc, node);
887 	dev_dbg(&chan->vc.chan.dev->device,
888 		"%s(): txd %p[%x]", __func__, vd_first, vd_first->tx.cookie);
889 
890 	vchan_issue_pending(&chan->vc);
891 	if (!pxad_try_hotchain(&chan->vc, vd_first))
892 		pxad_launch_chan(chan, to_pxad_sw_desc(vd_first));
893 out:
894 	spin_unlock_irqrestore(&chan->vc.lock, flags);
895 }
896 
897 static inline struct dma_async_tx_descriptor *
898 pxad_tx_prep(struct virt_dma_chan *vc, struct virt_dma_desc *vd,
899 		 unsigned long tx_flags)
900 {
901 	struct dma_async_tx_descriptor *tx;
902 	struct pxad_chan *chan = container_of(vc, struct pxad_chan, vc);
903 
904 	INIT_LIST_HEAD(&vd->node);
905 	tx = vchan_tx_prep(vc, vd, tx_flags);
906 	tx->tx_submit = pxad_tx_submit;
907 	dev_dbg(&chan->vc.chan.dev->device,
908 		"%s(): vc=%p txd=%p[%x] flags=0x%lx\n", __func__,
909 		vc, vd, vd->tx.cookie,
910 		tx_flags);
911 
912 	return tx;
913 }
914 
915 static void pxad_get_config(struct pxad_chan *chan,
916 			    enum dma_transfer_direction dir,
917 			    u32 *dcmd, u32 *dev_src, u32 *dev_dst)
918 {
919 	u32 maxburst = 0, dev_addr = 0;
920 	enum dma_slave_buswidth width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
921 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
922 
923 	*dcmd = 0;
924 	if (dir == DMA_DEV_TO_MEM) {
925 		maxburst = chan->cfg.src_maxburst;
926 		width = chan->cfg.src_addr_width;
927 		dev_addr = chan->cfg.src_addr;
928 		*dev_src = dev_addr;
929 		*dcmd |= PXA_DCMD_INCTRGADDR;
930 		if (chan->drcmr <= pdev->nr_requestors)
931 			*dcmd |= PXA_DCMD_FLOWSRC;
932 	}
933 	if (dir == DMA_MEM_TO_DEV) {
934 		maxburst = chan->cfg.dst_maxburst;
935 		width = chan->cfg.dst_addr_width;
936 		dev_addr = chan->cfg.dst_addr;
937 		*dev_dst = dev_addr;
938 		*dcmd |= PXA_DCMD_INCSRCADDR;
939 		if (chan->drcmr <= pdev->nr_requestors)
940 			*dcmd |= PXA_DCMD_FLOWTRG;
941 	}
942 	if (dir == DMA_MEM_TO_MEM)
943 		*dcmd |= PXA_DCMD_BURST32 | PXA_DCMD_INCTRGADDR |
944 			PXA_DCMD_INCSRCADDR;
945 
946 	dev_dbg(&chan->vc.chan.dev->device,
947 		"%s(): dev_addr=0x%x maxburst=%d width=%d  dir=%d\n",
948 		__func__, dev_addr, maxburst, width, dir);
949 
950 	if (width == DMA_SLAVE_BUSWIDTH_1_BYTE)
951 		*dcmd |= PXA_DCMD_WIDTH1;
952 	else if (width == DMA_SLAVE_BUSWIDTH_2_BYTES)
953 		*dcmd |= PXA_DCMD_WIDTH2;
954 	else if (width == DMA_SLAVE_BUSWIDTH_4_BYTES)
955 		*dcmd |= PXA_DCMD_WIDTH4;
956 
957 	if (maxburst == 8)
958 		*dcmd |= PXA_DCMD_BURST8;
959 	else if (maxburst == 16)
960 		*dcmd |= PXA_DCMD_BURST16;
961 	else if (maxburst == 32)
962 		*dcmd |= PXA_DCMD_BURST32;
963 
964 	/* FIXME: drivers should be ported over to use the filter
965 	 * function. Once that's done, the following two lines can
966 	 * be removed.
967 	 */
968 	if (chan->cfg.slave_id)
969 		chan->drcmr = chan->cfg.slave_id;
970 }
971 
972 static struct dma_async_tx_descriptor *
973 pxad_prep_memcpy(struct dma_chan *dchan,
974 		 dma_addr_t dma_dst, dma_addr_t dma_src,
975 		 size_t len, unsigned long flags)
976 {
977 	struct pxad_chan *chan = to_pxad_chan(dchan);
978 	struct pxad_desc_sw *sw_desc;
979 	struct pxad_desc_hw *hw_desc;
980 	u32 dcmd;
981 	unsigned int i, nb_desc = 0;
982 	size_t copy;
983 
984 	if (!dchan || !len)
985 		return NULL;
986 
987 	dev_dbg(&chan->vc.chan.dev->device,
988 		"%s(): dma_dst=0x%lx dma_src=0x%lx len=%zu flags=%lx\n",
989 		__func__, (unsigned long)dma_dst, (unsigned long)dma_src,
990 		len, flags);
991 	pxad_get_config(chan, DMA_MEM_TO_MEM, &dcmd, NULL, NULL);
992 
993 	nb_desc = DIV_ROUND_UP(len, PDMA_MAX_DESC_BYTES);
994 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
995 	if (!sw_desc)
996 		return NULL;
997 	sw_desc->len = len;
998 
999 	if (!IS_ALIGNED(dma_src, 1 << PDMA_ALIGNMENT) ||
1000 	    !IS_ALIGNED(dma_dst, 1 << PDMA_ALIGNMENT))
1001 		sw_desc->misaligned = true;
1002 
1003 	i = 0;
1004 	do {
1005 		hw_desc = sw_desc->hw_desc[i++];
1006 		copy = min_t(size_t, len, PDMA_MAX_DESC_BYTES);
1007 		hw_desc->dcmd = dcmd | (PXA_DCMD_LENGTH & copy);
1008 		hw_desc->dsadr = dma_src;
1009 		hw_desc->dtadr = dma_dst;
1010 		len -= copy;
1011 		dma_src += copy;
1012 		dma_dst += copy;
1013 	} while (len);
1014 	set_updater_desc(sw_desc, flags);
1015 
1016 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
1017 }
1018 
1019 static struct dma_async_tx_descriptor *
1020 pxad_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
1021 		   unsigned int sg_len, enum dma_transfer_direction dir,
1022 		   unsigned long flags, void *context)
1023 {
1024 	struct pxad_chan *chan = to_pxad_chan(dchan);
1025 	struct pxad_desc_sw *sw_desc;
1026 	size_t len, avail;
1027 	struct scatterlist *sg;
1028 	dma_addr_t dma;
1029 	u32 dcmd, dsadr = 0, dtadr = 0;
1030 	unsigned int nb_desc = 0, i, j = 0;
1031 
1032 	if ((sgl == NULL) || (sg_len == 0))
1033 		return NULL;
1034 
1035 	pxad_get_config(chan, dir, &dcmd, &dsadr, &dtadr);
1036 	dev_dbg(&chan->vc.chan.dev->device,
1037 		"%s(): dir=%d flags=%lx\n", __func__, dir, flags);
1038 
1039 	for_each_sg(sgl, sg, sg_len, i)
1040 		nb_desc += DIV_ROUND_UP(sg_dma_len(sg), PDMA_MAX_DESC_BYTES);
1041 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
1042 	if (!sw_desc)
1043 		return NULL;
1044 
1045 	for_each_sg(sgl, sg, sg_len, i) {
1046 		dma = sg_dma_address(sg);
1047 		avail = sg_dma_len(sg);
1048 		sw_desc->len += avail;
1049 
1050 		do {
1051 			len = min_t(size_t, avail, PDMA_MAX_DESC_BYTES);
1052 			if (dma & 0x7)
1053 				sw_desc->misaligned = true;
1054 
1055 			sw_desc->hw_desc[j]->dcmd =
1056 				dcmd | (PXA_DCMD_LENGTH & len);
1057 			sw_desc->hw_desc[j]->dsadr = dsadr ? dsadr : dma;
1058 			sw_desc->hw_desc[j++]->dtadr = dtadr ? dtadr : dma;
1059 
1060 			dma += len;
1061 			avail -= len;
1062 		} while (avail);
1063 	}
1064 	set_updater_desc(sw_desc, flags);
1065 
1066 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
1067 }
1068 
1069 static struct dma_async_tx_descriptor *
1070 pxad_prep_dma_cyclic(struct dma_chan *dchan,
1071 		     dma_addr_t buf_addr, size_t len, size_t period_len,
1072 		     enum dma_transfer_direction dir, unsigned long flags)
1073 {
1074 	struct pxad_chan *chan = to_pxad_chan(dchan);
1075 	struct pxad_desc_sw *sw_desc;
1076 	struct pxad_desc_hw **phw_desc;
1077 	dma_addr_t dma;
1078 	u32 dcmd, dsadr = 0, dtadr = 0;
1079 	unsigned int nb_desc = 0;
1080 
1081 	if (!dchan || !len || !period_len)
1082 		return NULL;
1083 	if ((dir != DMA_DEV_TO_MEM) && (dir != DMA_MEM_TO_DEV)) {
1084 		dev_err(&chan->vc.chan.dev->device,
1085 			"Unsupported direction for cyclic DMA\n");
1086 		return NULL;
1087 	}
1088 	/* the buffer length must be a multiple of period_len */
1089 	if (len % period_len != 0 || period_len > PDMA_MAX_DESC_BYTES ||
1090 	    !IS_ALIGNED(period_len, 1 << PDMA_ALIGNMENT))
1091 		return NULL;
1092 
1093 	pxad_get_config(chan, dir, &dcmd, &dsadr, &dtadr);
1094 	dcmd |= PXA_DCMD_ENDIRQEN | (PXA_DCMD_LENGTH & period_len);
1095 	dev_dbg(&chan->vc.chan.dev->device,
1096 		"%s(): buf_addr=0x%lx len=%zu period=%zu dir=%d flags=%lx\n",
1097 		__func__, (unsigned long)buf_addr, len, period_len, dir, flags);
1098 
1099 	nb_desc = DIV_ROUND_UP(period_len, PDMA_MAX_DESC_BYTES);
1100 	nb_desc *= DIV_ROUND_UP(len, period_len);
1101 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
1102 	if (!sw_desc)
1103 		return NULL;
1104 	sw_desc->cyclic = true;
1105 	sw_desc->len = len;
1106 
1107 	phw_desc = sw_desc->hw_desc;
1108 	dma = buf_addr;
1109 	do {
1110 		phw_desc[0]->dsadr = dsadr ? dsadr : dma;
1111 		phw_desc[0]->dtadr = dtadr ? dtadr : dma;
1112 		phw_desc[0]->dcmd = dcmd;
1113 		phw_desc++;
1114 		dma += period_len;
1115 		len -= period_len;
1116 	} while (len);
1117 	set_updater_desc(sw_desc, flags);
1118 
1119 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
1120 }
1121 
1122 static int pxad_config(struct dma_chan *dchan,
1123 		       struct dma_slave_config *cfg)
1124 {
1125 	struct pxad_chan *chan = to_pxad_chan(dchan);
1126 
1127 	if (!dchan)
1128 		return -EINVAL;
1129 
1130 	chan->cfg = *cfg;
1131 	return 0;
1132 }
1133 
1134 static int pxad_terminate_all(struct dma_chan *dchan)
1135 {
1136 	struct pxad_chan *chan = to_pxad_chan(dchan);
1137 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
1138 	struct virt_dma_desc *vd = NULL;
1139 	unsigned long flags;
1140 	struct pxad_phy *phy;
1141 	LIST_HEAD(head);
1142 
1143 	dev_dbg(&chan->vc.chan.dev->device,
1144 		"%s(): vchan %p: terminate all\n", __func__, &chan->vc);
1145 
1146 	spin_lock_irqsave(&chan->vc.lock, flags);
1147 	vchan_get_all_descriptors(&chan->vc, &head);
1148 
1149 	list_for_each_entry(vd, &head, node) {
1150 		dev_dbg(&chan->vc.chan.dev->device,
1151 			"%s(): cancelling txd %p[%x] (completed=%d)", __func__,
1152 			vd, vd->tx.cookie, is_desc_completed(vd));
1153 	}
1154 
1155 	phy = chan->phy;
1156 	if (phy) {
1157 		phy_disable(chan->phy);
1158 		pxad_free_phy(chan);
1159 		chan->phy = NULL;
1160 		spin_lock(&pdev->phy_lock);
1161 		phy->vchan = NULL;
1162 		spin_unlock(&pdev->phy_lock);
1163 	}
1164 	spin_unlock_irqrestore(&chan->vc.lock, flags);
1165 	vchan_dma_desc_free_list(&chan->vc, &head);
1166 
1167 	return 0;
1168 }
1169 
1170 static unsigned int pxad_residue(struct pxad_chan *chan,
1171 				 dma_cookie_t cookie)
1172 {
1173 	struct virt_dma_desc *vd = NULL;
1174 	struct pxad_desc_sw *sw_desc = NULL;
1175 	struct pxad_desc_hw *hw_desc = NULL;
1176 	u32 curr, start, len, end, residue = 0;
1177 	unsigned long flags;
1178 	bool passed = false;
1179 	int i;
1180 
1181 	/*
1182 	 * If the channel does not have a phy pointer anymore, it has already
1183 	 * been completed. Therefore, its residue is 0.
1184 	 */
1185 	if (!chan->phy)
1186 		return 0;
1187 
1188 	spin_lock_irqsave(&chan->vc.lock, flags);
1189 
1190 	vd = vchan_find_desc(&chan->vc, cookie);
1191 	if (!vd)
1192 		goto out;
1193 
1194 	sw_desc = to_pxad_sw_desc(vd);
1195 	if (sw_desc->hw_desc[0]->dcmd & PXA_DCMD_INCSRCADDR)
1196 		curr = phy_readl_relaxed(chan->phy, DSADR);
1197 	else
1198 		curr = phy_readl_relaxed(chan->phy, DTADR);
1199 
1200 	/*
1201 	 * curr has to be actually read before checking descriptor
1202 	 * completion, so that a curr inside a status updater
1203 	 * descriptor implies the following test returns true, and
1204 	 * preventing reordering of curr load and the test.
1205 	 */
1206 	rmb();
1207 	if (is_desc_completed(vd))
1208 		goto out;
1209 
1210 	for (i = 0; i < sw_desc->nb_desc - 1; i++) {
1211 		hw_desc = sw_desc->hw_desc[i];
1212 		if (sw_desc->hw_desc[0]->dcmd & PXA_DCMD_INCSRCADDR)
1213 			start = hw_desc->dsadr;
1214 		else
1215 			start = hw_desc->dtadr;
1216 		len = hw_desc->dcmd & PXA_DCMD_LENGTH;
1217 		end = start + len;
1218 
1219 		/*
1220 		 * 'passed' will be latched once we found the descriptor
1221 		 * which lies inside the boundaries of the curr
1222 		 * pointer. All descriptors that occur in the list
1223 		 * _after_ we found that partially handled descriptor
1224 		 * are still to be processed and are hence added to the
1225 		 * residual bytes counter.
1226 		 */
1227 
1228 		if (passed) {
1229 			residue += len;
1230 		} else if (curr >= start && curr <= end) {
1231 			residue += end - curr;
1232 			passed = true;
1233 		}
1234 	}
1235 	if (!passed)
1236 		residue = sw_desc->len;
1237 
1238 out:
1239 	spin_unlock_irqrestore(&chan->vc.lock, flags);
1240 	dev_dbg(&chan->vc.chan.dev->device,
1241 		"%s(): txd %p[%x] sw_desc=%p: %d\n",
1242 		__func__, vd, cookie, sw_desc, residue);
1243 	return residue;
1244 }
1245 
1246 static enum dma_status pxad_tx_status(struct dma_chan *dchan,
1247 				      dma_cookie_t cookie,
1248 				      struct dma_tx_state *txstate)
1249 {
1250 	struct pxad_chan *chan = to_pxad_chan(dchan);
1251 	enum dma_status ret;
1252 
1253 	if (cookie == chan->bus_error)
1254 		return DMA_ERROR;
1255 
1256 	ret = dma_cookie_status(dchan, cookie, txstate);
1257 	if (likely(txstate && (ret != DMA_ERROR)))
1258 		dma_set_residue(txstate, pxad_residue(chan, cookie));
1259 
1260 	return ret;
1261 }
1262 
1263 static void pxad_synchronize(struct dma_chan *dchan)
1264 {
1265 	struct pxad_chan *chan = to_pxad_chan(dchan);
1266 
1267 	wait_event(chan->wq_state, !is_chan_running(chan));
1268 	vchan_synchronize(&chan->vc);
1269 }
1270 
1271 static void pxad_free_channels(struct dma_device *dmadev)
1272 {
1273 	struct pxad_chan *c, *cn;
1274 
1275 	list_for_each_entry_safe(c, cn, &dmadev->channels,
1276 				 vc.chan.device_node) {
1277 		list_del(&c->vc.chan.device_node);
1278 		tasklet_kill(&c->vc.task);
1279 	}
1280 }
1281 
1282 static int pxad_remove(struct platform_device *op)
1283 {
1284 	struct pxad_device *pdev = platform_get_drvdata(op);
1285 
1286 	pxad_cleanup_debugfs(pdev);
1287 	pxad_free_channels(&pdev->slave);
1288 	return 0;
1289 }
1290 
1291 static int pxad_init_phys(struct platform_device *op,
1292 			  struct pxad_device *pdev,
1293 			  unsigned int nb_phy_chans)
1294 {
1295 	int irq0, irq, nr_irq = 0, i, ret;
1296 	struct pxad_phy *phy;
1297 
1298 	irq0 = platform_get_irq(op, 0);
1299 	if (irq0 < 0)
1300 		return irq0;
1301 
1302 	pdev->phys = devm_kcalloc(&op->dev, nb_phy_chans,
1303 				  sizeof(pdev->phys[0]), GFP_KERNEL);
1304 	if (!pdev->phys)
1305 		return -ENOMEM;
1306 
1307 	for (i = 0; i < nb_phy_chans; i++)
1308 		if (platform_get_irq(op, i) > 0)
1309 			nr_irq++;
1310 
1311 	for (i = 0; i < nb_phy_chans; i++) {
1312 		phy = &pdev->phys[i];
1313 		phy->base = pdev->base;
1314 		phy->idx = i;
1315 		irq = platform_get_irq(op, i);
1316 		if ((nr_irq > 1) && (irq > 0))
1317 			ret = devm_request_irq(&op->dev, irq,
1318 					       pxad_chan_handler,
1319 					       IRQF_SHARED, "pxa-dma", phy);
1320 		if ((nr_irq == 1) && (i == 0))
1321 			ret = devm_request_irq(&op->dev, irq0,
1322 					       pxad_int_handler,
1323 					       IRQF_SHARED, "pxa-dma", pdev);
1324 		if (ret) {
1325 			dev_err(pdev->slave.dev,
1326 				"%s(): can't request irq %d:%d\n", __func__,
1327 				irq, ret);
1328 			return ret;
1329 		}
1330 	}
1331 
1332 	return 0;
1333 }
1334 
1335 static const struct of_device_id pxad_dt_ids[] = {
1336 	{ .compatible = "marvell,pdma-1.0", },
1337 	{}
1338 };
1339 MODULE_DEVICE_TABLE(of, pxad_dt_ids);
1340 
1341 static struct dma_chan *pxad_dma_xlate(struct of_phandle_args *dma_spec,
1342 					   struct of_dma *ofdma)
1343 {
1344 	struct pxad_device *d = ofdma->of_dma_data;
1345 	struct dma_chan *chan;
1346 
1347 	chan = dma_get_any_slave_channel(&d->slave);
1348 	if (!chan)
1349 		return NULL;
1350 
1351 	to_pxad_chan(chan)->drcmr = dma_spec->args[0];
1352 	to_pxad_chan(chan)->prio = dma_spec->args[1];
1353 
1354 	return chan;
1355 }
1356 
1357 static int pxad_init_dmadev(struct platform_device *op,
1358 			    struct pxad_device *pdev,
1359 			    unsigned int nr_phy_chans,
1360 			    unsigned int nr_requestors)
1361 {
1362 	int ret;
1363 	unsigned int i;
1364 	struct pxad_chan *c;
1365 
1366 	pdev->nr_chans = nr_phy_chans;
1367 	pdev->nr_requestors = nr_requestors;
1368 	INIT_LIST_HEAD(&pdev->slave.channels);
1369 	pdev->slave.device_alloc_chan_resources = pxad_alloc_chan_resources;
1370 	pdev->slave.device_free_chan_resources = pxad_free_chan_resources;
1371 	pdev->slave.device_tx_status = pxad_tx_status;
1372 	pdev->slave.device_issue_pending = pxad_issue_pending;
1373 	pdev->slave.device_config = pxad_config;
1374 	pdev->slave.device_synchronize = pxad_synchronize;
1375 	pdev->slave.device_terminate_all = pxad_terminate_all;
1376 
1377 	if (op->dev.coherent_dma_mask)
1378 		dma_set_mask(&op->dev, op->dev.coherent_dma_mask);
1379 	else
1380 		dma_set_mask(&op->dev, DMA_BIT_MASK(32));
1381 
1382 	ret = pxad_init_phys(op, pdev, nr_phy_chans);
1383 	if (ret)
1384 		return ret;
1385 
1386 	for (i = 0; i < nr_phy_chans; i++) {
1387 		c = devm_kzalloc(&op->dev, sizeof(*c), GFP_KERNEL);
1388 		if (!c)
1389 			return -ENOMEM;
1390 
1391 		c->drcmr = U32_MAX;
1392 		c->prio = PXAD_PRIO_LOWEST;
1393 		c->vc.desc_free = pxad_free_desc;
1394 		vchan_init(&c->vc, &pdev->slave);
1395 		init_waitqueue_head(&c->wq_state);
1396 	}
1397 
1398 	return dmaenginem_async_device_register(&pdev->slave);
1399 }
1400 
1401 static int pxad_probe(struct platform_device *op)
1402 {
1403 	struct pxad_device *pdev;
1404 	const struct of_device_id *of_id;
1405 	const struct dma_slave_map *slave_map = NULL;
1406 	struct mmp_dma_platdata *pdata = dev_get_platdata(&op->dev);
1407 	struct resource *iores;
1408 	int ret, dma_channels = 0, nb_requestors = 0, slave_map_cnt = 0;
1409 	const enum dma_slave_buswidth widths =
1410 		DMA_SLAVE_BUSWIDTH_1_BYTE   | DMA_SLAVE_BUSWIDTH_2_BYTES |
1411 		DMA_SLAVE_BUSWIDTH_4_BYTES;
1412 
1413 	pdev = devm_kzalloc(&op->dev, sizeof(*pdev), GFP_KERNEL);
1414 	if (!pdev)
1415 		return -ENOMEM;
1416 
1417 	spin_lock_init(&pdev->phy_lock);
1418 
1419 	iores = platform_get_resource(op, IORESOURCE_MEM, 0);
1420 	pdev->base = devm_ioremap_resource(&op->dev, iores);
1421 	if (IS_ERR(pdev->base))
1422 		return PTR_ERR(pdev->base);
1423 
1424 	of_id = of_match_device(pxad_dt_ids, &op->dev);
1425 	if (of_id) {
1426 		of_property_read_u32(op->dev.of_node, "#dma-channels",
1427 				     &dma_channels);
1428 		ret = of_property_read_u32(op->dev.of_node, "#dma-requests",
1429 					   &nb_requestors);
1430 		if (ret) {
1431 			dev_warn(pdev->slave.dev,
1432 				 "#dma-requests set to default 32 as missing in OF: %d",
1433 				 ret);
1434 			nb_requestors = 32;
1435 		}
1436 	} else if (pdata && pdata->dma_channels) {
1437 		dma_channels = pdata->dma_channels;
1438 		nb_requestors = pdata->nb_requestors;
1439 		slave_map = pdata->slave_map;
1440 		slave_map_cnt = pdata->slave_map_cnt;
1441 	} else {
1442 		dma_channels = 32;	/* default 32 channel */
1443 	}
1444 
1445 	dma_cap_set(DMA_SLAVE, pdev->slave.cap_mask);
1446 	dma_cap_set(DMA_MEMCPY, pdev->slave.cap_mask);
1447 	dma_cap_set(DMA_CYCLIC, pdev->slave.cap_mask);
1448 	dma_cap_set(DMA_PRIVATE, pdev->slave.cap_mask);
1449 	pdev->slave.device_prep_dma_memcpy = pxad_prep_memcpy;
1450 	pdev->slave.device_prep_slave_sg = pxad_prep_slave_sg;
1451 	pdev->slave.device_prep_dma_cyclic = pxad_prep_dma_cyclic;
1452 	pdev->slave.filter.map = slave_map;
1453 	pdev->slave.filter.mapcnt = slave_map_cnt;
1454 	pdev->slave.filter.fn = pxad_filter_fn;
1455 
1456 	pdev->slave.copy_align = PDMA_ALIGNMENT;
1457 	pdev->slave.src_addr_widths = widths;
1458 	pdev->slave.dst_addr_widths = widths;
1459 	pdev->slave.directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
1460 	pdev->slave.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
1461 	pdev->slave.descriptor_reuse = true;
1462 
1463 	pdev->slave.dev = &op->dev;
1464 	ret = pxad_init_dmadev(op, pdev, dma_channels, nb_requestors);
1465 	if (ret) {
1466 		dev_err(pdev->slave.dev, "unable to register\n");
1467 		return ret;
1468 	}
1469 
1470 	if (op->dev.of_node) {
1471 		/* Device-tree DMA controller registration */
1472 		ret = of_dma_controller_register(op->dev.of_node,
1473 						 pxad_dma_xlate, pdev);
1474 		if (ret < 0) {
1475 			dev_err(pdev->slave.dev,
1476 				"of_dma_controller_register failed\n");
1477 			return ret;
1478 		}
1479 	}
1480 
1481 	platform_set_drvdata(op, pdev);
1482 	pxad_init_debugfs(pdev);
1483 	dev_info(pdev->slave.dev, "initialized %d channels on %d requestors\n",
1484 		 dma_channels, nb_requestors);
1485 	return 0;
1486 }
1487 
1488 static const struct platform_device_id pxad_id_table[] = {
1489 	{ "pxa-dma", },
1490 	{ },
1491 };
1492 
1493 static struct platform_driver pxad_driver = {
1494 	.driver		= {
1495 		.name	= "pxa-dma",
1496 		.of_match_table = pxad_dt_ids,
1497 	},
1498 	.id_table	= pxad_id_table,
1499 	.probe		= pxad_probe,
1500 	.remove		= pxad_remove,
1501 };
1502 
1503 bool pxad_filter_fn(struct dma_chan *chan, void *param)
1504 {
1505 	struct pxad_chan *c = to_pxad_chan(chan);
1506 	struct pxad_param *p = param;
1507 
1508 	if (chan->device->dev->driver != &pxad_driver.driver)
1509 		return false;
1510 
1511 	c->drcmr = p->drcmr;
1512 	c->prio = p->prio;
1513 
1514 	return true;
1515 }
1516 EXPORT_SYMBOL_GPL(pxad_filter_fn);
1517 
1518 module_platform_driver(pxad_driver);
1519 
1520 MODULE_DESCRIPTION("Marvell PXA Peripheral DMA Driver");
1521 MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");
1522 MODULE_LICENSE("GPL v2");
1523