xref: /openbmc/linux/drivers/dma/pxa_dma.c (revision 03638e62)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2015 Robert Jarzmik <robert.jarzmik@free.fr>
4  */
5 
6 #include <linux/err.h>
7 #include <linux/module.h>
8 #include <linux/init.h>
9 #include <linux/types.h>
10 #include <linux/interrupt.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/slab.h>
13 #include <linux/dmaengine.h>
14 #include <linux/platform_device.h>
15 #include <linux/device.h>
16 #include <linux/platform_data/mmp_dma.h>
17 #include <linux/dmapool.h>
18 #include <linux/of_device.h>
19 #include <linux/of_dma.h>
20 #include <linux/of.h>
21 #include <linux/wait.h>
22 #include <linux/dma/pxa-dma.h>
23 
24 #include "dmaengine.h"
25 #include "virt-dma.h"
26 
27 #define DCSR(n)		(0x0000 + ((n) << 2))
28 #define DALGN(n)	0x00a0
29 #define DINT		0x00f0
30 #define DDADR(n)	(0x0200 + ((n) << 4))
31 #define DSADR(n)	(0x0204 + ((n) << 4))
32 #define DTADR(n)	(0x0208 + ((n) << 4))
33 #define DCMD(n)		(0x020c + ((n) << 4))
34 
35 #define PXA_DCSR_RUN		BIT(31)	/* Run Bit (read / write) */
36 #define PXA_DCSR_NODESC		BIT(30)	/* No-Descriptor Fetch (read / write) */
37 #define PXA_DCSR_STOPIRQEN	BIT(29)	/* Stop Interrupt Enable (R/W) */
38 #define PXA_DCSR_REQPEND	BIT(8)	/* Request Pending (read-only) */
39 #define PXA_DCSR_STOPSTATE	BIT(3)	/* Stop State (read-only) */
40 #define PXA_DCSR_ENDINTR	BIT(2)	/* End Interrupt (read / write) */
41 #define PXA_DCSR_STARTINTR	BIT(1)	/* Start Interrupt (read / write) */
42 #define PXA_DCSR_BUSERR		BIT(0)	/* Bus Error Interrupt (read / write) */
43 
44 #define PXA_DCSR_EORIRQEN	BIT(28)	/* End of Receive IRQ Enable (R/W) */
45 #define PXA_DCSR_EORJMPEN	BIT(27)	/* Jump to next descriptor on EOR */
46 #define PXA_DCSR_EORSTOPEN	BIT(26)	/* STOP on an EOR */
47 #define PXA_DCSR_SETCMPST	BIT(25)	/* Set Descriptor Compare Status */
48 #define PXA_DCSR_CLRCMPST	BIT(24)	/* Clear Descriptor Compare Status */
49 #define PXA_DCSR_CMPST		BIT(10)	/* The Descriptor Compare Status */
50 #define PXA_DCSR_EORINTR	BIT(9)	/* The end of Receive */
51 
52 #define DRCMR_MAPVLD	BIT(7)	/* Map Valid (read / write) */
53 #define DRCMR_CHLNUM	0x1f	/* mask for Channel Number (read / write) */
54 
55 #define DDADR_DESCADDR	0xfffffff0	/* Address of next descriptor (mask) */
56 #define DDADR_STOP	BIT(0)	/* Stop (read / write) */
57 
58 #define PXA_DCMD_INCSRCADDR	BIT(31)	/* Source Address Increment Setting. */
59 #define PXA_DCMD_INCTRGADDR	BIT(30)	/* Target Address Increment Setting. */
60 #define PXA_DCMD_FLOWSRC	BIT(29)	/* Flow Control by the source. */
61 #define PXA_DCMD_FLOWTRG	BIT(28)	/* Flow Control by the target. */
62 #define PXA_DCMD_STARTIRQEN	BIT(22)	/* Start Interrupt Enable */
63 #define PXA_DCMD_ENDIRQEN	BIT(21)	/* End Interrupt Enable */
64 #define PXA_DCMD_ENDIAN		BIT(18)	/* Device Endian-ness. */
65 #define PXA_DCMD_BURST8		(1 << 16)	/* 8 byte burst */
66 #define PXA_DCMD_BURST16	(2 << 16)	/* 16 byte burst */
67 #define PXA_DCMD_BURST32	(3 << 16)	/* 32 byte burst */
68 #define PXA_DCMD_WIDTH1		(1 << 14)	/* 1 byte width */
69 #define PXA_DCMD_WIDTH2		(2 << 14)	/* 2 byte width (HalfWord) */
70 #define PXA_DCMD_WIDTH4		(3 << 14)	/* 4 byte width (Word) */
71 #define PXA_DCMD_LENGTH		0x01fff		/* length mask (max = 8K - 1) */
72 
73 #define PDMA_ALIGNMENT		3
74 #define PDMA_MAX_DESC_BYTES	(PXA_DCMD_LENGTH & ~((1 << PDMA_ALIGNMENT) - 1))
75 
76 struct pxad_desc_hw {
77 	u32 ddadr;	/* Points to the next descriptor + flags */
78 	u32 dsadr;	/* DSADR value for the current transfer */
79 	u32 dtadr;	/* DTADR value for the current transfer */
80 	u32 dcmd;	/* DCMD value for the current transfer */
81 } __aligned(16);
82 
83 struct pxad_desc_sw {
84 	struct virt_dma_desc	vd;		/* Virtual descriptor */
85 	int			nb_desc;	/* Number of hw. descriptors */
86 	size_t			len;		/* Number of bytes xfered */
87 	dma_addr_t		first;		/* First descriptor's addr */
88 
89 	/* At least one descriptor has an src/dst address not multiple of 8 */
90 	bool			misaligned;
91 	bool			cyclic;
92 	struct dma_pool		*desc_pool;	/* Channel's used allocator */
93 
94 	struct pxad_desc_hw	*hw_desc[];	/* DMA coherent descriptors */
95 };
96 
97 struct pxad_phy {
98 	int			idx;
99 	void __iomem		*base;
100 	struct pxad_chan	*vchan;
101 };
102 
103 struct pxad_chan {
104 	struct virt_dma_chan	vc;		/* Virtual channel */
105 	u32			drcmr;		/* Requestor of the channel */
106 	enum pxad_chan_prio	prio;		/* Required priority of phy */
107 	/*
108 	 * At least one desc_sw in submitted or issued transfers on this channel
109 	 * has one address such as: addr % 8 != 0. This implies the DALGN
110 	 * setting on the phy.
111 	 */
112 	bool			misaligned;
113 	struct dma_slave_config	cfg;		/* Runtime config */
114 
115 	/* protected by vc->lock */
116 	struct pxad_phy		*phy;
117 	struct dma_pool		*desc_pool;	/* Descriptors pool */
118 	dma_cookie_t		bus_error;
119 
120 	wait_queue_head_t	wq_state;
121 };
122 
123 struct pxad_device {
124 	struct dma_device		slave;
125 	int				nr_chans;
126 	int				nr_requestors;
127 	void __iomem			*base;
128 	struct pxad_phy			*phys;
129 	spinlock_t			phy_lock;	/* Phy association */
130 #ifdef CONFIG_DEBUG_FS
131 	struct dentry			*dbgfs_root;
132 	struct dentry			*dbgfs_state;
133 	struct dentry			**dbgfs_chan;
134 #endif
135 };
136 
137 #define tx_to_pxad_desc(tx)					\
138 	container_of(tx, struct pxad_desc_sw, async_tx)
139 #define to_pxad_chan(dchan)					\
140 	container_of(dchan, struct pxad_chan, vc.chan)
141 #define to_pxad_dev(dmadev)					\
142 	container_of(dmadev, struct pxad_device, slave)
143 #define to_pxad_sw_desc(_vd)				\
144 	container_of((_vd), struct pxad_desc_sw, vd)
145 
146 #define _phy_readl_relaxed(phy, _reg)					\
147 	readl_relaxed((phy)->base + _reg((phy)->idx))
148 #define phy_readl_relaxed(phy, _reg)					\
149 	({								\
150 		u32 _v;							\
151 		_v = readl_relaxed((phy)->base + _reg((phy)->idx));	\
152 		dev_vdbg(&phy->vchan->vc.chan.dev->device,		\
153 			 "%s(): readl(%s): 0x%08x\n", __func__, #_reg,	\
154 			  _v);						\
155 		_v;							\
156 	})
157 #define phy_writel(phy, val, _reg)					\
158 	do {								\
159 		writel((val), (phy)->base + _reg((phy)->idx));		\
160 		dev_vdbg(&phy->vchan->vc.chan.dev->device,		\
161 			 "%s(): writel(0x%08x, %s)\n",			\
162 			 __func__, (u32)(val), #_reg);			\
163 	} while (0)
164 #define phy_writel_relaxed(phy, val, _reg)				\
165 	do {								\
166 		writel_relaxed((val), (phy)->base + _reg((phy)->idx));	\
167 		dev_vdbg(&phy->vchan->vc.chan.dev->device,		\
168 			 "%s(): writel_relaxed(0x%08x, %s)\n",		\
169 			 __func__, (u32)(val), #_reg);			\
170 	} while (0)
171 
172 static unsigned int pxad_drcmr(unsigned int line)
173 {
174 	if (line < 64)
175 		return 0x100 + line * 4;
176 	return 0x1000 + line * 4;
177 }
178 
179 static bool pxad_filter_fn(struct dma_chan *chan, void *param);
180 
181 /*
182  * Debug fs
183  */
184 #ifdef CONFIG_DEBUG_FS
185 #include <linux/debugfs.h>
186 #include <linux/uaccess.h>
187 #include <linux/seq_file.h>
188 
189 static int requester_chan_show(struct seq_file *s, void *p)
190 {
191 	struct pxad_phy *phy = s->private;
192 	int i;
193 	u32 drcmr;
194 
195 	seq_printf(s, "DMA channel %d requester :\n", phy->idx);
196 	for (i = 0; i < 70; i++) {
197 		drcmr = readl_relaxed(phy->base + pxad_drcmr(i));
198 		if ((drcmr & DRCMR_CHLNUM) == phy->idx)
199 			seq_printf(s, "\tRequester %d (MAPVLD=%d)\n", i,
200 				   !!(drcmr & DRCMR_MAPVLD));
201 	}
202 	return 0;
203 }
204 
205 static inline int dbg_burst_from_dcmd(u32 dcmd)
206 {
207 	int burst = (dcmd >> 16) & 0x3;
208 
209 	return burst ? 4 << burst : 0;
210 }
211 
212 static int is_phys_valid(unsigned long addr)
213 {
214 	return pfn_valid(__phys_to_pfn(addr));
215 }
216 
217 #define PXA_DCSR_STR(flag) (dcsr & PXA_DCSR_##flag ? #flag" " : "")
218 #define PXA_DCMD_STR(flag) (dcmd & PXA_DCMD_##flag ? #flag" " : "")
219 
220 static int descriptors_show(struct seq_file *s, void *p)
221 {
222 	struct pxad_phy *phy = s->private;
223 	int i, max_show = 20, burst, width;
224 	u32 dcmd;
225 	unsigned long phys_desc, ddadr;
226 	struct pxad_desc_hw *desc;
227 
228 	phys_desc = ddadr = _phy_readl_relaxed(phy, DDADR);
229 
230 	seq_printf(s, "DMA channel %d descriptors :\n", phy->idx);
231 	seq_printf(s, "[%03d] First descriptor unknown\n", 0);
232 	for (i = 1; i < max_show && is_phys_valid(phys_desc); i++) {
233 		desc = phys_to_virt(phys_desc);
234 		dcmd = desc->dcmd;
235 		burst = dbg_burst_from_dcmd(dcmd);
236 		width = (1 << ((dcmd >> 14) & 0x3)) >> 1;
237 
238 		seq_printf(s, "[%03d] Desc at %08lx(virt %p)\n",
239 			   i, phys_desc, desc);
240 		seq_printf(s, "\tDDADR = %08x\n", desc->ddadr);
241 		seq_printf(s, "\tDSADR = %08x\n", desc->dsadr);
242 		seq_printf(s, "\tDTADR = %08x\n", desc->dtadr);
243 		seq_printf(s, "\tDCMD  = %08x (%s%s%s%s%s%s%sburst=%d width=%d len=%d)\n",
244 			   dcmd,
245 			   PXA_DCMD_STR(INCSRCADDR), PXA_DCMD_STR(INCTRGADDR),
246 			   PXA_DCMD_STR(FLOWSRC), PXA_DCMD_STR(FLOWTRG),
247 			   PXA_DCMD_STR(STARTIRQEN), PXA_DCMD_STR(ENDIRQEN),
248 			   PXA_DCMD_STR(ENDIAN), burst, width,
249 			   dcmd & PXA_DCMD_LENGTH);
250 		phys_desc = desc->ddadr;
251 	}
252 	if (i == max_show)
253 		seq_printf(s, "[%03d] Desc at %08lx ... max display reached\n",
254 			   i, phys_desc);
255 	else
256 		seq_printf(s, "[%03d] Desc at %08lx is %s\n",
257 			   i, phys_desc, phys_desc == DDADR_STOP ?
258 			   "DDADR_STOP" : "invalid");
259 
260 	return 0;
261 }
262 
263 static int chan_state_show(struct seq_file *s, void *p)
264 {
265 	struct pxad_phy *phy = s->private;
266 	u32 dcsr, dcmd;
267 	int burst, width;
268 	static const char * const str_prio[] = {
269 		"high", "normal", "low", "invalid"
270 	};
271 
272 	dcsr = _phy_readl_relaxed(phy, DCSR);
273 	dcmd = _phy_readl_relaxed(phy, DCMD);
274 	burst = dbg_burst_from_dcmd(dcmd);
275 	width = (1 << ((dcmd >> 14) & 0x3)) >> 1;
276 
277 	seq_printf(s, "DMA channel %d\n", phy->idx);
278 	seq_printf(s, "\tPriority : %s\n",
279 			  str_prio[(phy->idx & 0xf) / 4]);
280 	seq_printf(s, "\tUnaligned transfer bit: %s\n",
281 			  _phy_readl_relaxed(phy, DALGN) & BIT(phy->idx) ?
282 			  "yes" : "no");
283 	seq_printf(s, "\tDCSR  = %08x (%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s)\n",
284 		   dcsr, PXA_DCSR_STR(RUN), PXA_DCSR_STR(NODESC),
285 		   PXA_DCSR_STR(STOPIRQEN), PXA_DCSR_STR(EORIRQEN),
286 		   PXA_DCSR_STR(EORJMPEN), PXA_DCSR_STR(EORSTOPEN),
287 		   PXA_DCSR_STR(SETCMPST), PXA_DCSR_STR(CLRCMPST),
288 		   PXA_DCSR_STR(CMPST), PXA_DCSR_STR(EORINTR),
289 		   PXA_DCSR_STR(REQPEND), PXA_DCSR_STR(STOPSTATE),
290 		   PXA_DCSR_STR(ENDINTR), PXA_DCSR_STR(STARTINTR),
291 		   PXA_DCSR_STR(BUSERR));
292 
293 	seq_printf(s, "\tDCMD  = %08x (%s%s%s%s%s%s%sburst=%d width=%d len=%d)\n",
294 		   dcmd,
295 		   PXA_DCMD_STR(INCSRCADDR), PXA_DCMD_STR(INCTRGADDR),
296 		   PXA_DCMD_STR(FLOWSRC), PXA_DCMD_STR(FLOWTRG),
297 		   PXA_DCMD_STR(STARTIRQEN), PXA_DCMD_STR(ENDIRQEN),
298 		   PXA_DCMD_STR(ENDIAN), burst, width, dcmd & PXA_DCMD_LENGTH);
299 	seq_printf(s, "\tDSADR = %08x\n", _phy_readl_relaxed(phy, DSADR));
300 	seq_printf(s, "\tDTADR = %08x\n", _phy_readl_relaxed(phy, DTADR));
301 	seq_printf(s, "\tDDADR = %08x\n", _phy_readl_relaxed(phy, DDADR));
302 
303 	return 0;
304 }
305 
306 static int state_show(struct seq_file *s, void *p)
307 {
308 	struct pxad_device *pdev = s->private;
309 
310 	/* basic device status */
311 	seq_puts(s, "DMA engine status\n");
312 	seq_printf(s, "\tChannel number: %d\n", pdev->nr_chans);
313 
314 	return 0;
315 }
316 
317 DEFINE_SHOW_ATTRIBUTE(state);
318 DEFINE_SHOW_ATTRIBUTE(chan_state);
319 DEFINE_SHOW_ATTRIBUTE(descriptors);
320 DEFINE_SHOW_ATTRIBUTE(requester_chan);
321 
322 static struct dentry *pxad_dbg_alloc_chan(struct pxad_device *pdev,
323 					     int ch, struct dentry *chandir)
324 {
325 	char chan_name[11];
326 	struct dentry *chan, *chan_state = NULL, *chan_descr = NULL;
327 	struct dentry *chan_reqs = NULL;
328 	void *dt;
329 
330 	scnprintf(chan_name, sizeof(chan_name), "%d", ch);
331 	chan = debugfs_create_dir(chan_name, chandir);
332 	dt = (void *)&pdev->phys[ch];
333 
334 	if (chan)
335 		chan_state = debugfs_create_file("state", 0400, chan, dt,
336 						 &chan_state_fops);
337 	if (chan_state)
338 		chan_descr = debugfs_create_file("descriptors", 0400, chan, dt,
339 						 &descriptors_fops);
340 	if (chan_descr)
341 		chan_reqs = debugfs_create_file("requesters", 0400, chan, dt,
342 						&requester_chan_fops);
343 	if (!chan_reqs)
344 		goto err_state;
345 
346 	return chan;
347 
348 err_state:
349 	debugfs_remove_recursive(chan);
350 	return NULL;
351 }
352 
353 static void pxad_init_debugfs(struct pxad_device *pdev)
354 {
355 	int i;
356 	struct dentry *chandir;
357 
358 	pdev->dbgfs_root = debugfs_create_dir(dev_name(pdev->slave.dev), NULL);
359 	if (IS_ERR(pdev->dbgfs_root) || !pdev->dbgfs_root)
360 		goto err_root;
361 
362 	pdev->dbgfs_state = debugfs_create_file("state", 0400, pdev->dbgfs_root,
363 						pdev, &state_fops);
364 	if (!pdev->dbgfs_state)
365 		goto err_state;
366 
367 	pdev->dbgfs_chan =
368 		kmalloc_array(pdev->nr_chans, sizeof(*pdev->dbgfs_state),
369 			      GFP_KERNEL);
370 	if (!pdev->dbgfs_chan)
371 		goto err_alloc;
372 
373 	chandir = debugfs_create_dir("channels", pdev->dbgfs_root);
374 	if (!chandir)
375 		goto err_chandir;
376 
377 	for (i = 0; i < pdev->nr_chans; i++) {
378 		pdev->dbgfs_chan[i] = pxad_dbg_alloc_chan(pdev, i, chandir);
379 		if (!pdev->dbgfs_chan[i])
380 			goto err_chans;
381 	}
382 
383 	return;
384 err_chans:
385 err_chandir:
386 	kfree(pdev->dbgfs_chan);
387 err_alloc:
388 err_state:
389 	debugfs_remove_recursive(pdev->dbgfs_root);
390 err_root:
391 	pr_err("pxad: debugfs is not available\n");
392 }
393 
394 static void pxad_cleanup_debugfs(struct pxad_device *pdev)
395 {
396 	debugfs_remove_recursive(pdev->dbgfs_root);
397 }
398 #else
399 static inline void pxad_init_debugfs(struct pxad_device *pdev) {}
400 static inline void pxad_cleanup_debugfs(struct pxad_device *pdev) {}
401 #endif
402 
403 static struct pxad_phy *lookup_phy(struct pxad_chan *pchan)
404 {
405 	int prio, i;
406 	struct pxad_device *pdev = to_pxad_dev(pchan->vc.chan.device);
407 	struct pxad_phy *phy, *found = NULL;
408 	unsigned long flags;
409 
410 	/*
411 	 * dma channel priorities
412 	 * ch 0 - 3,  16 - 19  <--> (0)
413 	 * ch 4 - 7,  20 - 23  <--> (1)
414 	 * ch 8 - 11, 24 - 27  <--> (2)
415 	 * ch 12 - 15, 28 - 31  <--> (3)
416 	 */
417 
418 	spin_lock_irqsave(&pdev->phy_lock, flags);
419 	for (prio = pchan->prio; prio >= PXAD_PRIO_HIGHEST; prio--) {
420 		for (i = 0; i < pdev->nr_chans; i++) {
421 			if (prio != (i & 0xf) >> 2)
422 				continue;
423 			phy = &pdev->phys[i];
424 			if (!phy->vchan) {
425 				phy->vchan = pchan;
426 				found = phy;
427 				goto out_unlock;
428 			}
429 		}
430 	}
431 
432 out_unlock:
433 	spin_unlock_irqrestore(&pdev->phy_lock, flags);
434 	dev_dbg(&pchan->vc.chan.dev->device,
435 		"%s(): phy=%p(%d)\n", __func__, found,
436 		found ? found->idx : -1);
437 
438 	return found;
439 }
440 
441 static void pxad_free_phy(struct pxad_chan *chan)
442 {
443 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
444 	unsigned long flags;
445 	u32 reg;
446 
447 	dev_dbg(&chan->vc.chan.dev->device,
448 		"%s(): freeing\n", __func__);
449 	if (!chan->phy)
450 		return;
451 
452 	/* clear the channel mapping in DRCMR */
453 	if (chan->drcmr <= pdev->nr_requestors) {
454 		reg = pxad_drcmr(chan->drcmr);
455 		writel_relaxed(0, chan->phy->base + reg);
456 	}
457 
458 	spin_lock_irqsave(&pdev->phy_lock, flags);
459 	chan->phy->vchan = NULL;
460 	chan->phy = NULL;
461 	spin_unlock_irqrestore(&pdev->phy_lock, flags);
462 }
463 
464 static bool is_chan_running(struct pxad_chan *chan)
465 {
466 	u32 dcsr;
467 	struct pxad_phy *phy = chan->phy;
468 
469 	if (!phy)
470 		return false;
471 	dcsr = phy_readl_relaxed(phy, DCSR);
472 	return dcsr & PXA_DCSR_RUN;
473 }
474 
475 static bool is_running_chan_misaligned(struct pxad_chan *chan)
476 {
477 	u32 dalgn;
478 
479 	BUG_ON(!chan->phy);
480 	dalgn = phy_readl_relaxed(chan->phy, DALGN);
481 	return dalgn & (BIT(chan->phy->idx));
482 }
483 
484 static void phy_enable(struct pxad_phy *phy, bool misaligned)
485 {
486 	struct pxad_device *pdev;
487 	u32 reg, dalgn;
488 
489 	if (!phy->vchan)
490 		return;
491 
492 	dev_dbg(&phy->vchan->vc.chan.dev->device,
493 		"%s(); phy=%p(%d) misaligned=%d\n", __func__,
494 		phy, phy->idx, misaligned);
495 
496 	pdev = to_pxad_dev(phy->vchan->vc.chan.device);
497 	if (phy->vchan->drcmr <= pdev->nr_requestors) {
498 		reg = pxad_drcmr(phy->vchan->drcmr);
499 		writel_relaxed(DRCMR_MAPVLD | phy->idx, phy->base + reg);
500 	}
501 
502 	dalgn = phy_readl_relaxed(phy, DALGN);
503 	if (misaligned)
504 		dalgn |= BIT(phy->idx);
505 	else
506 		dalgn &= ~BIT(phy->idx);
507 	phy_writel_relaxed(phy, dalgn, DALGN);
508 
509 	phy_writel(phy, PXA_DCSR_STOPIRQEN | PXA_DCSR_ENDINTR |
510 		   PXA_DCSR_BUSERR | PXA_DCSR_RUN, DCSR);
511 }
512 
513 static void phy_disable(struct pxad_phy *phy)
514 {
515 	u32 dcsr;
516 
517 	if (!phy)
518 		return;
519 
520 	dcsr = phy_readl_relaxed(phy, DCSR);
521 	dev_dbg(&phy->vchan->vc.chan.dev->device,
522 		"%s(): phy=%p(%d)\n", __func__, phy, phy->idx);
523 	phy_writel(phy, dcsr & ~PXA_DCSR_RUN & ~PXA_DCSR_STOPIRQEN, DCSR);
524 }
525 
526 static void pxad_launch_chan(struct pxad_chan *chan,
527 				 struct pxad_desc_sw *desc)
528 {
529 	dev_dbg(&chan->vc.chan.dev->device,
530 		"%s(): desc=%p\n", __func__, desc);
531 	if (!chan->phy) {
532 		chan->phy = lookup_phy(chan);
533 		if (!chan->phy) {
534 			dev_dbg(&chan->vc.chan.dev->device,
535 				"%s(): no free dma channel\n", __func__);
536 			return;
537 		}
538 	}
539 	chan->bus_error = 0;
540 
541 	/*
542 	 * Program the descriptor's address into the DMA controller,
543 	 * then start the DMA transaction
544 	 */
545 	phy_writel(chan->phy, desc->first, DDADR);
546 	phy_enable(chan->phy, chan->misaligned);
547 	wake_up(&chan->wq_state);
548 }
549 
550 static void set_updater_desc(struct pxad_desc_sw *sw_desc,
551 			     unsigned long flags)
552 {
553 	struct pxad_desc_hw *updater =
554 		sw_desc->hw_desc[sw_desc->nb_desc - 1];
555 	dma_addr_t dma = sw_desc->hw_desc[sw_desc->nb_desc - 2]->ddadr;
556 
557 	updater->ddadr = DDADR_STOP;
558 	updater->dsadr = dma;
559 	updater->dtadr = dma + 8;
560 	updater->dcmd = PXA_DCMD_WIDTH4 | PXA_DCMD_BURST32 |
561 		(PXA_DCMD_LENGTH & sizeof(u32));
562 	if (flags & DMA_PREP_INTERRUPT)
563 		updater->dcmd |= PXA_DCMD_ENDIRQEN;
564 	if (sw_desc->cyclic)
565 		sw_desc->hw_desc[sw_desc->nb_desc - 2]->ddadr = sw_desc->first;
566 }
567 
568 static bool is_desc_completed(struct virt_dma_desc *vd)
569 {
570 	struct pxad_desc_sw *sw_desc = to_pxad_sw_desc(vd);
571 	struct pxad_desc_hw *updater =
572 		sw_desc->hw_desc[sw_desc->nb_desc - 1];
573 
574 	return updater->dtadr != (updater->dsadr + 8);
575 }
576 
577 static void pxad_desc_chain(struct virt_dma_desc *vd1,
578 				struct virt_dma_desc *vd2)
579 {
580 	struct pxad_desc_sw *desc1 = to_pxad_sw_desc(vd1);
581 	struct pxad_desc_sw *desc2 = to_pxad_sw_desc(vd2);
582 	dma_addr_t dma_to_chain;
583 
584 	dma_to_chain = desc2->first;
585 	desc1->hw_desc[desc1->nb_desc - 1]->ddadr = dma_to_chain;
586 }
587 
588 static bool pxad_try_hotchain(struct virt_dma_chan *vc,
589 				  struct virt_dma_desc *vd)
590 {
591 	struct virt_dma_desc *vd_last_issued = NULL;
592 	struct pxad_chan *chan = to_pxad_chan(&vc->chan);
593 
594 	/*
595 	 * Attempt to hot chain the tx if the phy is still running. This is
596 	 * considered successful only if either the channel is still running
597 	 * after the chaining, or if the chained transfer is completed after
598 	 * having been hot chained.
599 	 * A change of alignment is not allowed, and forbids hotchaining.
600 	 */
601 	if (is_chan_running(chan)) {
602 		BUG_ON(list_empty(&vc->desc_issued));
603 
604 		if (!is_running_chan_misaligned(chan) &&
605 		    to_pxad_sw_desc(vd)->misaligned)
606 			return false;
607 
608 		vd_last_issued = list_entry(vc->desc_issued.prev,
609 					    struct virt_dma_desc, node);
610 		pxad_desc_chain(vd_last_issued, vd);
611 		if (is_chan_running(chan) || is_desc_completed(vd))
612 			return true;
613 	}
614 
615 	return false;
616 }
617 
618 static unsigned int clear_chan_irq(struct pxad_phy *phy)
619 {
620 	u32 dcsr;
621 	u32 dint = readl(phy->base + DINT);
622 
623 	if (!(dint & BIT(phy->idx)))
624 		return PXA_DCSR_RUN;
625 
626 	/* clear irq */
627 	dcsr = phy_readl_relaxed(phy, DCSR);
628 	phy_writel(phy, dcsr, DCSR);
629 	if ((dcsr & PXA_DCSR_BUSERR) && (phy->vchan))
630 		dev_warn(&phy->vchan->vc.chan.dev->device,
631 			 "%s(chan=%p): PXA_DCSR_BUSERR\n",
632 			 __func__, &phy->vchan);
633 
634 	return dcsr & ~PXA_DCSR_RUN;
635 }
636 
637 static irqreturn_t pxad_chan_handler(int irq, void *dev_id)
638 {
639 	struct pxad_phy *phy = dev_id;
640 	struct pxad_chan *chan = phy->vchan;
641 	struct virt_dma_desc *vd, *tmp;
642 	unsigned int dcsr;
643 	unsigned long flags;
644 	bool vd_completed;
645 	dma_cookie_t last_started = 0;
646 
647 	BUG_ON(!chan);
648 
649 	dcsr = clear_chan_irq(phy);
650 	if (dcsr & PXA_DCSR_RUN)
651 		return IRQ_NONE;
652 
653 	spin_lock_irqsave(&chan->vc.lock, flags);
654 	list_for_each_entry_safe(vd, tmp, &chan->vc.desc_issued, node) {
655 		vd_completed = is_desc_completed(vd);
656 		dev_dbg(&chan->vc.chan.dev->device,
657 			"%s(): checking txd %p[%x]: completed=%d dcsr=0x%x\n",
658 			__func__, vd, vd->tx.cookie, vd_completed,
659 			dcsr);
660 		last_started = vd->tx.cookie;
661 		if (to_pxad_sw_desc(vd)->cyclic) {
662 			vchan_cyclic_callback(vd);
663 			break;
664 		}
665 		if (vd_completed) {
666 			list_del(&vd->node);
667 			vchan_cookie_complete(vd);
668 		} else {
669 			break;
670 		}
671 	}
672 
673 	if (dcsr & PXA_DCSR_BUSERR) {
674 		chan->bus_error = last_started;
675 		phy_disable(phy);
676 	}
677 
678 	if (!chan->bus_error && dcsr & PXA_DCSR_STOPSTATE) {
679 		dev_dbg(&chan->vc.chan.dev->device,
680 		"%s(): channel stopped, submitted_empty=%d issued_empty=%d",
681 			__func__,
682 			list_empty(&chan->vc.desc_submitted),
683 			list_empty(&chan->vc.desc_issued));
684 		phy_writel_relaxed(phy, dcsr & ~PXA_DCSR_STOPIRQEN, DCSR);
685 
686 		if (list_empty(&chan->vc.desc_issued)) {
687 			chan->misaligned =
688 				!list_empty(&chan->vc.desc_submitted);
689 		} else {
690 			vd = list_first_entry(&chan->vc.desc_issued,
691 					      struct virt_dma_desc, node);
692 			pxad_launch_chan(chan, to_pxad_sw_desc(vd));
693 		}
694 	}
695 	spin_unlock_irqrestore(&chan->vc.lock, flags);
696 	wake_up(&chan->wq_state);
697 
698 	return IRQ_HANDLED;
699 }
700 
701 static irqreturn_t pxad_int_handler(int irq, void *dev_id)
702 {
703 	struct pxad_device *pdev = dev_id;
704 	struct pxad_phy *phy;
705 	u32 dint = readl(pdev->base + DINT);
706 	int i, ret = IRQ_NONE;
707 
708 	while (dint) {
709 		i = __ffs(dint);
710 		dint &= (dint - 1);
711 		phy = &pdev->phys[i];
712 		if (pxad_chan_handler(irq, phy) == IRQ_HANDLED)
713 			ret = IRQ_HANDLED;
714 	}
715 
716 	return ret;
717 }
718 
719 static int pxad_alloc_chan_resources(struct dma_chan *dchan)
720 {
721 	struct pxad_chan *chan = to_pxad_chan(dchan);
722 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
723 
724 	if (chan->desc_pool)
725 		return 1;
726 
727 	chan->desc_pool = dma_pool_create(dma_chan_name(dchan),
728 					  pdev->slave.dev,
729 					  sizeof(struct pxad_desc_hw),
730 					  __alignof__(struct pxad_desc_hw),
731 					  0);
732 	if (!chan->desc_pool) {
733 		dev_err(&chan->vc.chan.dev->device,
734 			"%s(): unable to allocate descriptor pool\n",
735 			__func__);
736 		return -ENOMEM;
737 	}
738 
739 	return 1;
740 }
741 
742 static void pxad_free_chan_resources(struct dma_chan *dchan)
743 {
744 	struct pxad_chan *chan = to_pxad_chan(dchan);
745 
746 	vchan_free_chan_resources(&chan->vc);
747 	dma_pool_destroy(chan->desc_pool);
748 	chan->desc_pool = NULL;
749 
750 	chan->drcmr = U32_MAX;
751 	chan->prio = PXAD_PRIO_LOWEST;
752 }
753 
754 static void pxad_free_desc(struct virt_dma_desc *vd)
755 {
756 	int i;
757 	dma_addr_t dma;
758 	struct pxad_desc_sw *sw_desc = to_pxad_sw_desc(vd);
759 
760 	BUG_ON(sw_desc->nb_desc == 0);
761 	for (i = sw_desc->nb_desc - 1; i >= 0; i--) {
762 		if (i > 0)
763 			dma = sw_desc->hw_desc[i - 1]->ddadr;
764 		else
765 			dma = sw_desc->first;
766 		dma_pool_free(sw_desc->desc_pool,
767 			      sw_desc->hw_desc[i], dma);
768 	}
769 	sw_desc->nb_desc = 0;
770 	kfree(sw_desc);
771 }
772 
773 static struct pxad_desc_sw *
774 pxad_alloc_desc(struct pxad_chan *chan, unsigned int nb_hw_desc)
775 {
776 	struct pxad_desc_sw *sw_desc;
777 	dma_addr_t dma;
778 	int i;
779 
780 	sw_desc = kzalloc(sizeof(*sw_desc) +
781 			  nb_hw_desc * sizeof(struct pxad_desc_hw *),
782 			  GFP_NOWAIT);
783 	if (!sw_desc)
784 		return NULL;
785 	sw_desc->desc_pool = chan->desc_pool;
786 
787 	for (i = 0; i < nb_hw_desc; i++) {
788 		sw_desc->hw_desc[i] = dma_pool_alloc(sw_desc->desc_pool,
789 						     GFP_NOWAIT, &dma);
790 		if (!sw_desc->hw_desc[i]) {
791 			dev_err(&chan->vc.chan.dev->device,
792 				"%s(): Couldn't allocate the %dth hw_desc from dma_pool %p\n",
793 				__func__, i, sw_desc->desc_pool);
794 			goto err;
795 		}
796 
797 		if (i == 0)
798 			sw_desc->first = dma;
799 		else
800 			sw_desc->hw_desc[i - 1]->ddadr = dma;
801 		sw_desc->nb_desc++;
802 	}
803 
804 	return sw_desc;
805 err:
806 	pxad_free_desc(&sw_desc->vd);
807 	return NULL;
808 }
809 
810 static dma_cookie_t pxad_tx_submit(struct dma_async_tx_descriptor *tx)
811 {
812 	struct virt_dma_chan *vc = to_virt_chan(tx->chan);
813 	struct pxad_chan *chan = to_pxad_chan(&vc->chan);
814 	struct virt_dma_desc *vd_chained = NULL,
815 		*vd = container_of(tx, struct virt_dma_desc, tx);
816 	dma_cookie_t cookie;
817 	unsigned long flags;
818 
819 	set_updater_desc(to_pxad_sw_desc(vd), tx->flags);
820 
821 	spin_lock_irqsave(&vc->lock, flags);
822 	cookie = dma_cookie_assign(tx);
823 
824 	if (list_empty(&vc->desc_submitted) && pxad_try_hotchain(vc, vd)) {
825 		list_move_tail(&vd->node, &vc->desc_issued);
826 		dev_dbg(&chan->vc.chan.dev->device,
827 			"%s(): txd %p[%x]: submitted (hot linked)\n",
828 			__func__, vd, cookie);
829 		goto out;
830 	}
831 
832 	/*
833 	 * Fallback to placing the tx in the submitted queue
834 	 */
835 	if (!list_empty(&vc->desc_submitted)) {
836 		vd_chained = list_entry(vc->desc_submitted.prev,
837 					struct virt_dma_desc, node);
838 		/*
839 		 * Only chain the descriptors if no new misalignment is
840 		 * introduced. If a new misalignment is chained, let the channel
841 		 * stop, and be relaunched in misalign mode from the irq
842 		 * handler.
843 		 */
844 		if (chan->misaligned || !to_pxad_sw_desc(vd)->misaligned)
845 			pxad_desc_chain(vd_chained, vd);
846 		else
847 			vd_chained = NULL;
848 	}
849 	dev_dbg(&chan->vc.chan.dev->device,
850 		"%s(): txd %p[%x]: submitted (%s linked)\n",
851 		__func__, vd, cookie, vd_chained ? "cold" : "not");
852 	list_move_tail(&vd->node, &vc->desc_submitted);
853 	chan->misaligned |= to_pxad_sw_desc(vd)->misaligned;
854 
855 out:
856 	spin_unlock_irqrestore(&vc->lock, flags);
857 	return cookie;
858 }
859 
860 static void pxad_issue_pending(struct dma_chan *dchan)
861 {
862 	struct pxad_chan *chan = to_pxad_chan(dchan);
863 	struct virt_dma_desc *vd_first;
864 	unsigned long flags;
865 
866 	spin_lock_irqsave(&chan->vc.lock, flags);
867 	if (list_empty(&chan->vc.desc_submitted))
868 		goto out;
869 
870 	vd_first = list_first_entry(&chan->vc.desc_submitted,
871 				    struct virt_dma_desc, node);
872 	dev_dbg(&chan->vc.chan.dev->device,
873 		"%s(): txd %p[%x]", __func__, vd_first, vd_first->tx.cookie);
874 
875 	vchan_issue_pending(&chan->vc);
876 	if (!pxad_try_hotchain(&chan->vc, vd_first))
877 		pxad_launch_chan(chan, to_pxad_sw_desc(vd_first));
878 out:
879 	spin_unlock_irqrestore(&chan->vc.lock, flags);
880 }
881 
882 static inline struct dma_async_tx_descriptor *
883 pxad_tx_prep(struct virt_dma_chan *vc, struct virt_dma_desc *vd,
884 		 unsigned long tx_flags)
885 {
886 	struct dma_async_tx_descriptor *tx;
887 	struct pxad_chan *chan = container_of(vc, struct pxad_chan, vc);
888 
889 	INIT_LIST_HEAD(&vd->node);
890 	tx = vchan_tx_prep(vc, vd, tx_flags);
891 	tx->tx_submit = pxad_tx_submit;
892 	dev_dbg(&chan->vc.chan.dev->device,
893 		"%s(): vc=%p txd=%p[%x] flags=0x%lx\n", __func__,
894 		vc, vd, vd->tx.cookie,
895 		tx_flags);
896 
897 	return tx;
898 }
899 
900 static void pxad_get_config(struct pxad_chan *chan,
901 			    enum dma_transfer_direction dir,
902 			    u32 *dcmd, u32 *dev_src, u32 *dev_dst)
903 {
904 	u32 maxburst = 0, dev_addr = 0;
905 	enum dma_slave_buswidth width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
906 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
907 
908 	*dcmd = 0;
909 	if (dir == DMA_DEV_TO_MEM) {
910 		maxburst = chan->cfg.src_maxburst;
911 		width = chan->cfg.src_addr_width;
912 		dev_addr = chan->cfg.src_addr;
913 		*dev_src = dev_addr;
914 		*dcmd |= PXA_DCMD_INCTRGADDR;
915 		if (chan->drcmr <= pdev->nr_requestors)
916 			*dcmd |= PXA_DCMD_FLOWSRC;
917 	}
918 	if (dir == DMA_MEM_TO_DEV) {
919 		maxburst = chan->cfg.dst_maxburst;
920 		width = chan->cfg.dst_addr_width;
921 		dev_addr = chan->cfg.dst_addr;
922 		*dev_dst = dev_addr;
923 		*dcmd |= PXA_DCMD_INCSRCADDR;
924 		if (chan->drcmr <= pdev->nr_requestors)
925 			*dcmd |= PXA_DCMD_FLOWTRG;
926 	}
927 	if (dir == DMA_MEM_TO_MEM)
928 		*dcmd |= PXA_DCMD_BURST32 | PXA_DCMD_INCTRGADDR |
929 			PXA_DCMD_INCSRCADDR;
930 
931 	dev_dbg(&chan->vc.chan.dev->device,
932 		"%s(): dev_addr=0x%x maxburst=%d width=%d  dir=%d\n",
933 		__func__, dev_addr, maxburst, width, dir);
934 
935 	if (width == DMA_SLAVE_BUSWIDTH_1_BYTE)
936 		*dcmd |= PXA_DCMD_WIDTH1;
937 	else if (width == DMA_SLAVE_BUSWIDTH_2_BYTES)
938 		*dcmd |= PXA_DCMD_WIDTH2;
939 	else if (width == DMA_SLAVE_BUSWIDTH_4_BYTES)
940 		*dcmd |= PXA_DCMD_WIDTH4;
941 
942 	if (maxburst == 8)
943 		*dcmd |= PXA_DCMD_BURST8;
944 	else if (maxburst == 16)
945 		*dcmd |= PXA_DCMD_BURST16;
946 	else if (maxburst == 32)
947 		*dcmd |= PXA_DCMD_BURST32;
948 
949 	/* FIXME: drivers should be ported over to use the filter
950 	 * function. Once that's done, the following two lines can
951 	 * be removed.
952 	 */
953 	if (chan->cfg.slave_id)
954 		chan->drcmr = chan->cfg.slave_id;
955 }
956 
957 static struct dma_async_tx_descriptor *
958 pxad_prep_memcpy(struct dma_chan *dchan,
959 		 dma_addr_t dma_dst, dma_addr_t dma_src,
960 		 size_t len, unsigned long flags)
961 {
962 	struct pxad_chan *chan = to_pxad_chan(dchan);
963 	struct pxad_desc_sw *sw_desc;
964 	struct pxad_desc_hw *hw_desc;
965 	u32 dcmd;
966 	unsigned int i, nb_desc = 0;
967 	size_t copy;
968 
969 	if (!dchan || !len)
970 		return NULL;
971 
972 	dev_dbg(&chan->vc.chan.dev->device,
973 		"%s(): dma_dst=0x%lx dma_src=0x%lx len=%zu flags=%lx\n",
974 		__func__, (unsigned long)dma_dst, (unsigned long)dma_src,
975 		len, flags);
976 	pxad_get_config(chan, DMA_MEM_TO_MEM, &dcmd, NULL, NULL);
977 
978 	nb_desc = DIV_ROUND_UP(len, PDMA_MAX_DESC_BYTES);
979 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
980 	if (!sw_desc)
981 		return NULL;
982 	sw_desc->len = len;
983 
984 	if (!IS_ALIGNED(dma_src, 1 << PDMA_ALIGNMENT) ||
985 	    !IS_ALIGNED(dma_dst, 1 << PDMA_ALIGNMENT))
986 		sw_desc->misaligned = true;
987 
988 	i = 0;
989 	do {
990 		hw_desc = sw_desc->hw_desc[i++];
991 		copy = min_t(size_t, len, PDMA_MAX_DESC_BYTES);
992 		hw_desc->dcmd = dcmd | (PXA_DCMD_LENGTH & copy);
993 		hw_desc->dsadr = dma_src;
994 		hw_desc->dtadr = dma_dst;
995 		len -= copy;
996 		dma_src += copy;
997 		dma_dst += copy;
998 	} while (len);
999 	set_updater_desc(sw_desc, flags);
1000 
1001 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
1002 }
1003 
1004 static struct dma_async_tx_descriptor *
1005 pxad_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
1006 		   unsigned int sg_len, enum dma_transfer_direction dir,
1007 		   unsigned long flags, void *context)
1008 {
1009 	struct pxad_chan *chan = to_pxad_chan(dchan);
1010 	struct pxad_desc_sw *sw_desc;
1011 	size_t len, avail;
1012 	struct scatterlist *sg;
1013 	dma_addr_t dma;
1014 	u32 dcmd, dsadr = 0, dtadr = 0;
1015 	unsigned int nb_desc = 0, i, j = 0;
1016 
1017 	if ((sgl == NULL) || (sg_len == 0))
1018 		return NULL;
1019 
1020 	pxad_get_config(chan, dir, &dcmd, &dsadr, &dtadr);
1021 	dev_dbg(&chan->vc.chan.dev->device,
1022 		"%s(): dir=%d flags=%lx\n", __func__, dir, flags);
1023 
1024 	for_each_sg(sgl, sg, sg_len, i)
1025 		nb_desc += DIV_ROUND_UP(sg_dma_len(sg), PDMA_MAX_DESC_BYTES);
1026 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
1027 	if (!sw_desc)
1028 		return NULL;
1029 
1030 	for_each_sg(sgl, sg, sg_len, i) {
1031 		dma = sg_dma_address(sg);
1032 		avail = sg_dma_len(sg);
1033 		sw_desc->len += avail;
1034 
1035 		do {
1036 			len = min_t(size_t, avail, PDMA_MAX_DESC_BYTES);
1037 			if (dma & 0x7)
1038 				sw_desc->misaligned = true;
1039 
1040 			sw_desc->hw_desc[j]->dcmd =
1041 				dcmd | (PXA_DCMD_LENGTH & len);
1042 			sw_desc->hw_desc[j]->dsadr = dsadr ? dsadr : dma;
1043 			sw_desc->hw_desc[j++]->dtadr = dtadr ? dtadr : dma;
1044 
1045 			dma += len;
1046 			avail -= len;
1047 		} while (avail);
1048 	}
1049 	set_updater_desc(sw_desc, flags);
1050 
1051 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
1052 }
1053 
1054 static struct dma_async_tx_descriptor *
1055 pxad_prep_dma_cyclic(struct dma_chan *dchan,
1056 		     dma_addr_t buf_addr, size_t len, size_t period_len,
1057 		     enum dma_transfer_direction dir, unsigned long flags)
1058 {
1059 	struct pxad_chan *chan = to_pxad_chan(dchan);
1060 	struct pxad_desc_sw *sw_desc;
1061 	struct pxad_desc_hw **phw_desc;
1062 	dma_addr_t dma;
1063 	u32 dcmd, dsadr = 0, dtadr = 0;
1064 	unsigned int nb_desc = 0;
1065 
1066 	if (!dchan || !len || !period_len)
1067 		return NULL;
1068 	if ((dir != DMA_DEV_TO_MEM) && (dir != DMA_MEM_TO_DEV)) {
1069 		dev_err(&chan->vc.chan.dev->device,
1070 			"Unsupported direction for cyclic DMA\n");
1071 		return NULL;
1072 	}
1073 	/* the buffer length must be a multiple of period_len */
1074 	if (len % period_len != 0 || period_len > PDMA_MAX_DESC_BYTES ||
1075 	    !IS_ALIGNED(period_len, 1 << PDMA_ALIGNMENT))
1076 		return NULL;
1077 
1078 	pxad_get_config(chan, dir, &dcmd, &dsadr, &dtadr);
1079 	dcmd |= PXA_DCMD_ENDIRQEN | (PXA_DCMD_LENGTH & period_len);
1080 	dev_dbg(&chan->vc.chan.dev->device,
1081 		"%s(): buf_addr=0x%lx len=%zu period=%zu dir=%d flags=%lx\n",
1082 		__func__, (unsigned long)buf_addr, len, period_len, dir, flags);
1083 
1084 	nb_desc = DIV_ROUND_UP(period_len, PDMA_MAX_DESC_BYTES);
1085 	nb_desc *= DIV_ROUND_UP(len, period_len);
1086 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
1087 	if (!sw_desc)
1088 		return NULL;
1089 	sw_desc->cyclic = true;
1090 	sw_desc->len = len;
1091 
1092 	phw_desc = sw_desc->hw_desc;
1093 	dma = buf_addr;
1094 	do {
1095 		phw_desc[0]->dsadr = dsadr ? dsadr : dma;
1096 		phw_desc[0]->dtadr = dtadr ? dtadr : dma;
1097 		phw_desc[0]->dcmd = dcmd;
1098 		phw_desc++;
1099 		dma += period_len;
1100 		len -= period_len;
1101 	} while (len);
1102 	set_updater_desc(sw_desc, flags);
1103 
1104 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
1105 }
1106 
1107 static int pxad_config(struct dma_chan *dchan,
1108 		       struct dma_slave_config *cfg)
1109 {
1110 	struct pxad_chan *chan = to_pxad_chan(dchan);
1111 
1112 	if (!dchan)
1113 		return -EINVAL;
1114 
1115 	chan->cfg = *cfg;
1116 	return 0;
1117 }
1118 
1119 static int pxad_terminate_all(struct dma_chan *dchan)
1120 {
1121 	struct pxad_chan *chan = to_pxad_chan(dchan);
1122 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
1123 	struct virt_dma_desc *vd = NULL;
1124 	unsigned long flags;
1125 	struct pxad_phy *phy;
1126 	LIST_HEAD(head);
1127 
1128 	dev_dbg(&chan->vc.chan.dev->device,
1129 		"%s(): vchan %p: terminate all\n", __func__, &chan->vc);
1130 
1131 	spin_lock_irqsave(&chan->vc.lock, flags);
1132 	vchan_get_all_descriptors(&chan->vc, &head);
1133 
1134 	list_for_each_entry(vd, &head, node) {
1135 		dev_dbg(&chan->vc.chan.dev->device,
1136 			"%s(): cancelling txd %p[%x] (completed=%d)", __func__,
1137 			vd, vd->tx.cookie, is_desc_completed(vd));
1138 	}
1139 
1140 	phy = chan->phy;
1141 	if (phy) {
1142 		phy_disable(chan->phy);
1143 		pxad_free_phy(chan);
1144 		chan->phy = NULL;
1145 		spin_lock(&pdev->phy_lock);
1146 		phy->vchan = NULL;
1147 		spin_unlock(&pdev->phy_lock);
1148 	}
1149 	spin_unlock_irqrestore(&chan->vc.lock, flags);
1150 	vchan_dma_desc_free_list(&chan->vc, &head);
1151 
1152 	return 0;
1153 }
1154 
1155 static unsigned int pxad_residue(struct pxad_chan *chan,
1156 				 dma_cookie_t cookie)
1157 {
1158 	struct virt_dma_desc *vd = NULL;
1159 	struct pxad_desc_sw *sw_desc = NULL;
1160 	struct pxad_desc_hw *hw_desc = NULL;
1161 	u32 curr, start, len, end, residue = 0;
1162 	unsigned long flags;
1163 	bool passed = false;
1164 	int i;
1165 
1166 	/*
1167 	 * If the channel does not have a phy pointer anymore, it has already
1168 	 * been completed. Therefore, its residue is 0.
1169 	 */
1170 	if (!chan->phy)
1171 		return 0;
1172 
1173 	spin_lock_irqsave(&chan->vc.lock, flags);
1174 
1175 	vd = vchan_find_desc(&chan->vc, cookie);
1176 	if (!vd)
1177 		goto out;
1178 
1179 	sw_desc = to_pxad_sw_desc(vd);
1180 	if (sw_desc->hw_desc[0]->dcmd & PXA_DCMD_INCSRCADDR)
1181 		curr = phy_readl_relaxed(chan->phy, DSADR);
1182 	else
1183 		curr = phy_readl_relaxed(chan->phy, DTADR);
1184 
1185 	/*
1186 	 * curr has to be actually read before checking descriptor
1187 	 * completion, so that a curr inside a status updater
1188 	 * descriptor implies the following test returns true, and
1189 	 * preventing reordering of curr load and the test.
1190 	 */
1191 	rmb();
1192 	if (is_desc_completed(vd))
1193 		goto out;
1194 
1195 	for (i = 0; i < sw_desc->nb_desc - 1; i++) {
1196 		hw_desc = sw_desc->hw_desc[i];
1197 		if (sw_desc->hw_desc[0]->dcmd & PXA_DCMD_INCSRCADDR)
1198 			start = hw_desc->dsadr;
1199 		else
1200 			start = hw_desc->dtadr;
1201 		len = hw_desc->dcmd & PXA_DCMD_LENGTH;
1202 		end = start + len;
1203 
1204 		/*
1205 		 * 'passed' will be latched once we found the descriptor
1206 		 * which lies inside the boundaries of the curr
1207 		 * pointer. All descriptors that occur in the list
1208 		 * _after_ we found that partially handled descriptor
1209 		 * are still to be processed and are hence added to the
1210 		 * residual bytes counter.
1211 		 */
1212 
1213 		if (passed) {
1214 			residue += len;
1215 		} else if (curr >= start && curr <= end) {
1216 			residue += end - curr;
1217 			passed = true;
1218 		}
1219 	}
1220 	if (!passed)
1221 		residue = sw_desc->len;
1222 
1223 out:
1224 	spin_unlock_irqrestore(&chan->vc.lock, flags);
1225 	dev_dbg(&chan->vc.chan.dev->device,
1226 		"%s(): txd %p[%x] sw_desc=%p: %d\n",
1227 		__func__, vd, cookie, sw_desc, residue);
1228 	return residue;
1229 }
1230 
1231 static enum dma_status pxad_tx_status(struct dma_chan *dchan,
1232 				      dma_cookie_t cookie,
1233 				      struct dma_tx_state *txstate)
1234 {
1235 	struct pxad_chan *chan = to_pxad_chan(dchan);
1236 	enum dma_status ret;
1237 
1238 	if (cookie == chan->bus_error)
1239 		return DMA_ERROR;
1240 
1241 	ret = dma_cookie_status(dchan, cookie, txstate);
1242 	if (likely(txstate && (ret != DMA_ERROR)))
1243 		dma_set_residue(txstate, pxad_residue(chan, cookie));
1244 
1245 	return ret;
1246 }
1247 
1248 static void pxad_synchronize(struct dma_chan *dchan)
1249 {
1250 	struct pxad_chan *chan = to_pxad_chan(dchan);
1251 
1252 	wait_event(chan->wq_state, !is_chan_running(chan));
1253 	vchan_synchronize(&chan->vc);
1254 }
1255 
1256 static void pxad_free_channels(struct dma_device *dmadev)
1257 {
1258 	struct pxad_chan *c, *cn;
1259 
1260 	list_for_each_entry_safe(c, cn, &dmadev->channels,
1261 				 vc.chan.device_node) {
1262 		list_del(&c->vc.chan.device_node);
1263 		tasklet_kill(&c->vc.task);
1264 	}
1265 }
1266 
1267 static int pxad_remove(struct platform_device *op)
1268 {
1269 	struct pxad_device *pdev = platform_get_drvdata(op);
1270 
1271 	pxad_cleanup_debugfs(pdev);
1272 	pxad_free_channels(&pdev->slave);
1273 	return 0;
1274 }
1275 
1276 static int pxad_init_phys(struct platform_device *op,
1277 			  struct pxad_device *pdev,
1278 			  unsigned int nb_phy_chans)
1279 {
1280 	int irq0, irq, nr_irq = 0, i, ret;
1281 	struct pxad_phy *phy;
1282 
1283 	irq0 = platform_get_irq(op, 0);
1284 	if (irq0 < 0)
1285 		return irq0;
1286 
1287 	pdev->phys = devm_kcalloc(&op->dev, nb_phy_chans,
1288 				  sizeof(pdev->phys[0]), GFP_KERNEL);
1289 	if (!pdev->phys)
1290 		return -ENOMEM;
1291 
1292 	for (i = 0; i < nb_phy_chans; i++)
1293 		if (platform_get_irq(op, i) > 0)
1294 			nr_irq++;
1295 
1296 	for (i = 0; i < nb_phy_chans; i++) {
1297 		phy = &pdev->phys[i];
1298 		phy->base = pdev->base;
1299 		phy->idx = i;
1300 		irq = platform_get_irq(op, i);
1301 		if ((nr_irq > 1) && (irq > 0))
1302 			ret = devm_request_irq(&op->dev, irq,
1303 					       pxad_chan_handler,
1304 					       IRQF_SHARED, "pxa-dma", phy);
1305 		if ((nr_irq == 1) && (i == 0))
1306 			ret = devm_request_irq(&op->dev, irq0,
1307 					       pxad_int_handler,
1308 					       IRQF_SHARED, "pxa-dma", pdev);
1309 		if (ret) {
1310 			dev_err(pdev->slave.dev,
1311 				"%s(): can't request irq %d:%d\n", __func__,
1312 				irq, ret);
1313 			return ret;
1314 		}
1315 	}
1316 
1317 	return 0;
1318 }
1319 
1320 static const struct of_device_id pxad_dt_ids[] = {
1321 	{ .compatible = "marvell,pdma-1.0", },
1322 	{}
1323 };
1324 MODULE_DEVICE_TABLE(of, pxad_dt_ids);
1325 
1326 static struct dma_chan *pxad_dma_xlate(struct of_phandle_args *dma_spec,
1327 					   struct of_dma *ofdma)
1328 {
1329 	struct pxad_device *d = ofdma->of_dma_data;
1330 	struct dma_chan *chan;
1331 
1332 	chan = dma_get_any_slave_channel(&d->slave);
1333 	if (!chan)
1334 		return NULL;
1335 
1336 	to_pxad_chan(chan)->drcmr = dma_spec->args[0];
1337 	to_pxad_chan(chan)->prio = dma_spec->args[1];
1338 
1339 	return chan;
1340 }
1341 
1342 static int pxad_init_dmadev(struct platform_device *op,
1343 			    struct pxad_device *pdev,
1344 			    unsigned int nr_phy_chans,
1345 			    unsigned int nr_requestors)
1346 {
1347 	int ret;
1348 	unsigned int i;
1349 	struct pxad_chan *c;
1350 
1351 	pdev->nr_chans = nr_phy_chans;
1352 	pdev->nr_requestors = nr_requestors;
1353 	INIT_LIST_HEAD(&pdev->slave.channels);
1354 	pdev->slave.device_alloc_chan_resources = pxad_alloc_chan_resources;
1355 	pdev->slave.device_free_chan_resources = pxad_free_chan_resources;
1356 	pdev->slave.device_tx_status = pxad_tx_status;
1357 	pdev->slave.device_issue_pending = pxad_issue_pending;
1358 	pdev->slave.device_config = pxad_config;
1359 	pdev->slave.device_synchronize = pxad_synchronize;
1360 	pdev->slave.device_terminate_all = pxad_terminate_all;
1361 
1362 	if (op->dev.coherent_dma_mask)
1363 		dma_set_mask(&op->dev, op->dev.coherent_dma_mask);
1364 	else
1365 		dma_set_mask(&op->dev, DMA_BIT_MASK(32));
1366 
1367 	ret = pxad_init_phys(op, pdev, nr_phy_chans);
1368 	if (ret)
1369 		return ret;
1370 
1371 	for (i = 0; i < nr_phy_chans; i++) {
1372 		c = devm_kzalloc(&op->dev, sizeof(*c), GFP_KERNEL);
1373 		if (!c)
1374 			return -ENOMEM;
1375 
1376 		c->drcmr = U32_MAX;
1377 		c->prio = PXAD_PRIO_LOWEST;
1378 		c->vc.desc_free = pxad_free_desc;
1379 		vchan_init(&c->vc, &pdev->slave);
1380 		init_waitqueue_head(&c->wq_state);
1381 	}
1382 
1383 	return dmaenginem_async_device_register(&pdev->slave);
1384 }
1385 
1386 static int pxad_probe(struct platform_device *op)
1387 {
1388 	struct pxad_device *pdev;
1389 	const struct of_device_id *of_id;
1390 	const struct dma_slave_map *slave_map = NULL;
1391 	struct mmp_dma_platdata *pdata = dev_get_platdata(&op->dev);
1392 	struct resource *iores;
1393 	int ret, dma_channels = 0, nb_requestors = 0, slave_map_cnt = 0;
1394 	const enum dma_slave_buswidth widths =
1395 		DMA_SLAVE_BUSWIDTH_1_BYTE   | DMA_SLAVE_BUSWIDTH_2_BYTES |
1396 		DMA_SLAVE_BUSWIDTH_4_BYTES;
1397 
1398 	pdev = devm_kzalloc(&op->dev, sizeof(*pdev), GFP_KERNEL);
1399 	if (!pdev)
1400 		return -ENOMEM;
1401 
1402 	spin_lock_init(&pdev->phy_lock);
1403 
1404 	iores = platform_get_resource(op, IORESOURCE_MEM, 0);
1405 	pdev->base = devm_ioremap_resource(&op->dev, iores);
1406 	if (IS_ERR(pdev->base))
1407 		return PTR_ERR(pdev->base);
1408 
1409 	of_id = of_match_device(pxad_dt_ids, &op->dev);
1410 	if (of_id) {
1411 		of_property_read_u32(op->dev.of_node, "#dma-channels",
1412 				     &dma_channels);
1413 		ret = of_property_read_u32(op->dev.of_node, "#dma-requests",
1414 					   &nb_requestors);
1415 		if (ret) {
1416 			dev_warn(pdev->slave.dev,
1417 				 "#dma-requests set to default 32 as missing in OF: %d",
1418 				 ret);
1419 			nb_requestors = 32;
1420 		}
1421 	} else if (pdata && pdata->dma_channels) {
1422 		dma_channels = pdata->dma_channels;
1423 		nb_requestors = pdata->nb_requestors;
1424 		slave_map = pdata->slave_map;
1425 		slave_map_cnt = pdata->slave_map_cnt;
1426 	} else {
1427 		dma_channels = 32;	/* default 32 channel */
1428 	}
1429 
1430 	dma_cap_set(DMA_SLAVE, pdev->slave.cap_mask);
1431 	dma_cap_set(DMA_MEMCPY, pdev->slave.cap_mask);
1432 	dma_cap_set(DMA_CYCLIC, pdev->slave.cap_mask);
1433 	dma_cap_set(DMA_PRIVATE, pdev->slave.cap_mask);
1434 	pdev->slave.device_prep_dma_memcpy = pxad_prep_memcpy;
1435 	pdev->slave.device_prep_slave_sg = pxad_prep_slave_sg;
1436 	pdev->slave.device_prep_dma_cyclic = pxad_prep_dma_cyclic;
1437 	pdev->slave.filter.map = slave_map;
1438 	pdev->slave.filter.mapcnt = slave_map_cnt;
1439 	pdev->slave.filter.fn = pxad_filter_fn;
1440 
1441 	pdev->slave.copy_align = PDMA_ALIGNMENT;
1442 	pdev->slave.src_addr_widths = widths;
1443 	pdev->slave.dst_addr_widths = widths;
1444 	pdev->slave.directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
1445 	pdev->slave.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
1446 	pdev->slave.descriptor_reuse = true;
1447 
1448 	pdev->slave.dev = &op->dev;
1449 	ret = pxad_init_dmadev(op, pdev, dma_channels, nb_requestors);
1450 	if (ret) {
1451 		dev_err(pdev->slave.dev, "unable to register\n");
1452 		return ret;
1453 	}
1454 
1455 	if (op->dev.of_node) {
1456 		/* Device-tree DMA controller registration */
1457 		ret = of_dma_controller_register(op->dev.of_node,
1458 						 pxad_dma_xlate, pdev);
1459 		if (ret < 0) {
1460 			dev_err(pdev->slave.dev,
1461 				"of_dma_controller_register failed\n");
1462 			return ret;
1463 		}
1464 	}
1465 
1466 	platform_set_drvdata(op, pdev);
1467 	pxad_init_debugfs(pdev);
1468 	dev_info(pdev->slave.dev, "initialized %d channels on %d requestors\n",
1469 		 dma_channels, nb_requestors);
1470 	return 0;
1471 }
1472 
1473 static const struct platform_device_id pxad_id_table[] = {
1474 	{ "pxa-dma", },
1475 	{ },
1476 };
1477 
1478 static struct platform_driver pxad_driver = {
1479 	.driver		= {
1480 		.name	= "pxa-dma",
1481 		.of_match_table = pxad_dt_ids,
1482 	},
1483 	.id_table	= pxad_id_table,
1484 	.probe		= pxad_probe,
1485 	.remove		= pxad_remove,
1486 };
1487 
1488 static bool pxad_filter_fn(struct dma_chan *chan, void *param)
1489 {
1490 	struct pxad_chan *c = to_pxad_chan(chan);
1491 	struct pxad_param *p = param;
1492 
1493 	if (chan->device->dev->driver != &pxad_driver.driver)
1494 		return false;
1495 
1496 	c->drcmr = p->drcmr;
1497 	c->prio = p->prio;
1498 
1499 	return true;
1500 }
1501 
1502 module_platform_driver(pxad_driver);
1503 
1504 MODULE_DESCRIPTION("Marvell PXA Peripheral DMA Driver");
1505 MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");
1506 MODULE_LICENSE("GPL v2");
1507