xref: /linux/drivers/dma/pxa_dma.c (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
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 static 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 requester_chan_show(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 descriptors_show(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 chan_state_show(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 state_show(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_SHOW_ATTRIBUTE(state);
321 DEFINE_SHOW_ATTRIBUTE(chan_state);
322 DEFINE_SHOW_ATTRIBUTE(descriptors);
323 DEFINE_SHOW_ATTRIBUTE(requester_chan);
324 
325 static struct dentry *pxad_dbg_alloc_chan(struct pxad_device *pdev,
326 					     int ch, struct dentry *chandir)
327 {
328 	char chan_name[11];
329 	struct dentry *chan, *chan_state = NULL, *chan_descr = NULL;
330 	struct dentry *chan_reqs = NULL;
331 	void *dt;
332 
333 	scnprintf(chan_name, sizeof(chan_name), "%d", ch);
334 	chan = debugfs_create_dir(chan_name, chandir);
335 	dt = (void *)&pdev->phys[ch];
336 
337 	if (chan)
338 		chan_state = debugfs_create_file("state", 0400, chan, dt,
339 						 &chan_state_fops);
340 	if (chan_state)
341 		chan_descr = debugfs_create_file("descriptors", 0400, chan, dt,
342 						 &descriptors_fops);
343 	if (chan_descr)
344 		chan_reqs = debugfs_create_file("requesters", 0400, chan, dt,
345 						&requester_chan_fops);
346 	if (!chan_reqs)
347 		goto err_state;
348 
349 	return chan;
350 
351 err_state:
352 	debugfs_remove_recursive(chan);
353 	return NULL;
354 }
355 
356 static void pxad_init_debugfs(struct pxad_device *pdev)
357 {
358 	int i;
359 	struct dentry *chandir;
360 
361 	pdev->dbgfs_root = debugfs_create_dir(dev_name(pdev->slave.dev), NULL);
362 	if (IS_ERR(pdev->dbgfs_root) || !pdev->dbgfs_root)
363 		goto err_root;
364 
365 	pdev->dbgfs_state = debugfs_create_file("state", 0400, pdev->dbgfs_root,
366 						pdev, &state_fops);
367 	if (!pdev->dbgfs_state)
368 		goto err_state;
369 
370 	pdev->dbgfs_chan =
371 		kmalloc_array(pdev->nr_chans, sizeof(*pdev->dbgfs_state),
372 			      GFP_KERNEL);
373 	if (!pdev->dbgfs_chan)
374 		goto err_alloc;
375 
376 	chandir = debugfs_create_dir("channels", pdev->dbgfs_root);
377 	if (!chandir)
378 		goto err_chandir;
379 
380 	for (i = 0; i < pdev->nr_chans; i++) {
381 		pdev->dbgfs_chan[i] = pxad_dbg_alloc_chan(pdev, i, chandir);
382 		if (!pdev->dbgfs_chan[i])
383 			goto err_chans;
384 	}
385 
386 	return;
387 err_chans:
388 err_chandir:
389 	kfree(pdev->dbgfs_chan);
390 err_alloc:
391 err_state:
392 	debugfs_remove_recursive(pdev->dbgfs_root);
393 err_root:
394 	pr_err("pxad: debugfs is not available\n");
395 }
396 
397 static void pxad_cleanup_debugfs(struct pxad_device *pdev)
398 {
399 	debugfs_remove_recursive(pdev->dbgfs_root);
400 }
401 #else
402 static inline void pxad_init_debugfs(struct pxad_device *pdev) {}
403 static inline void pxad_cleanup_debugfs(struct pxad_device *pdev) {}
404 #endif
405 
406 static struct pxad_phy *lookup_phy(struct pxad_chan *pchan)
407 {
408 	int prio, i;
409 	struct pxad_device *pdev = to_pxad_dev(pchan->vc.chan.device);
410 	struct pxad_phy *phy, *found = NULL;
411 	unsigned long flags;
412 
413 	/*
414 	 * dma channel priorities
415 	 * ch 0 - 3,  16 - 19  <--> (0)
416 	 * ch 4 - 7,  20 - 23  <--> (1)
417 	 * ch 8 - 11, 24 - 27  <--> (2)
418 	 * ch 12 - 15, 28 - 31  <--> (3)
419 	 */
420 
421 	spin_lock_irqsave(&pdev->phy_lock, flags);
422 	for (prio = pchan->prio; prio >= PXAD_PRIO_HIGHEST; prio--) {
423 		for (i = 0; i < pdev->nr_chans; i++) {
424 			if (prio != (i & 0xf) >> 2)
425 				continue;
426 			phy = &pdev->phys[i];
427 			if (!phy->vchan) {
428 				phy->vchan = pchan;
429 				found = phy;
430 				goto out_unlock;
431 			}
432 		}
433 	}
434 
435 out_unlock:
436 	spin_unlock_irqrestore(&pdev->phy_lock, flags);
437 	dev_dbg(&pchan->vc.chan.dev->device,
438 		"%s(): phy=%p(%d)\n", __func__, found,
439 		found ? found->idx : -1);
440 
441 	return found;
442 }
443 
444 static void pxad_free_phy(struct pxad_chan *chan)
445 {
446 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
447 	unsigned long flags;
448 	u32 reg;
449 
450 	dev_dbg(&chan->vc.chan.dev->device,
451 		"%s(): freeing\n", __func__);
452 	if (!chan->phy)
453 		return;
454 
455 	/* clear the channel mapping in DRCMR */
456 	if (chan->drcmr <= pdev->nr_requestors) {
457 		reg = pxad_drcmr(chan->drcmr);
458 		writel_relaxed(0, chan->phy->base + reg);
459 	}
460 
461 	spin_lock_irqsave(&pdev->phy_lock, flags);
462 	chan->phy->vchan = NULL;
463 	chan->phy = NULL;
464 	spin_unlock_irqrestore(&pdev->phy_lock, flags);
465 }
466 
467 static bool is_chan_running(struct pxad_chan *chan)
468 {
469 	u32 dcsr;
470 	struct pxad_phy *phy = chan->phy;
471 
472 	if (!phy)
473 		return false;
474 	dcsr = phy_readl_relaxed(phy, DCSR);
475 	return dcsr & PXA_DCSR_RUN;
476 }
477 
478 static bool is_running_chan_misaligned(struct pxad_chan *chan)
479 {
480 	u32 dalgn;
481 
482 	BUG_ON(!chan->phy);
483 	dalgn = phy_readl_relaxed(chan->phy, DALGN);
484 	return dalgn & (BIT(chan->phy->idx));
485 }
486 
487 static void phy_enable(struct pxad_phy *phy, bool misaligned)
488 {
489 	struct pxad_device *pdev;
490 	u32 reg, dalgn;
491 
492 	if (!phy->vchan)
493 		return;
494 
495 	dev_dbg(&phy->vchan->vc.chan.dev->device,
496 		"%s(); phy=%p(%d) misaligned=%d\n", __func__,
497 		phy, phy->idx, misaligned);
498 
499 	pdev = to_pxad_dev(phy->vchan->vc.chan.device);
500 	if (phy->vchan->drcmr <= pdev->nr_requestors) {
501 		reg = pxad_drcmr(phy->vchan->drcmr);
502 		writel_relaxed(DRCMR_MAPVLD | phy->idx, phy->base + reg);
503 	}
504 
505 	dalgn = phy_readl_relaxed(phy, DALGN);
506 	if (misaligned)
507 		dalgn |= BIT(phy->idx);
508 	else
509 		dalgn &= ~BIT(phy->idx);
510 	phy_writel_relaxed(phy, dalgn, DALGN);
511 
512 	phy_writel(phy, PXA_DCSR_STOPIRQEN | PXA_DCSR_ENDINTR |
513 		   PXA_DCSR_BUSERR | PXA_DCSR_RUN, DCSR);
514 }
515 
516 static void phy_disable(struct pxad_phy *phy)
517 {
518 	u32 dcsr;
519 
520 	if (!phy)
521 		return;
522 
523 	dcsr = phy_readl_relaxed(phy, DCSR);
524 	dev_dbg(&phy->vchan->vc.chan.dev->device,
525 		"%s(): phy=%p(%d)\n", __func__, phy, phy->idx);
526 	phy_writel(phy, dcsr & ~PXA_DCSR_RUN & ~PXA_DCSR_STOPIRQEN, DCSR);
527 }
528 
529 static void pxad_launch_chan(struct pxad_chan *chan,
530 				 struct pxad_desc_sw *desc)
531 {
532 	dev_dbg(&chan->vc.chan.dev->device,
533 		"%s(): desc=%p\n", __func__, desc);
534 	if (!chan->phy) {
535 		chan->phy = lookup_phy(chan);
536 		if (!chan->phy) {
537 			dev_dbg(&chan->vc.chan.dev->device,
538 				"%s(): no free dma channel\n", __func__);
539 			return;
540 		}
541 	}
542 	chan->bus_error = 0;
543 
544 	/*
545 	 * Program the descriptor's address into the DMA controller,
546 	 * then start the DMA transaction
547 	 */
548 	phy_writel(chan->phy, desc->first, DDADR);
549 	phy_enable(chan->phy, chan->misaligned);
550 	wake_up(&chan->wq_state);
551 }
552 
553 static void set_updater_desc(struct pxad_desc_sw *sw_desc,
554 			     unsigned long flags)
555 {
556 	struct pxad_desc_hw *updater =
557 		sw_desc->hw_desc[sw_desc->nb_desc - 1];
558 	dma_addr_t dma = sw_desc->hw_desc[sw_desc->nb_desc - 2]->ddadr;
559 
560 	updater->ddadr = DDADR_STOP;
561 	updater->dsadr = dma;
562 	updater->dtadr = dma + 8;
563 	updater->dcmd = PXA_DCMD_WIDTH4 | PXA_DCMD_BURST32 |
564 		(PXA_DCMD_LENGTH & sizeof(u32));
565 	if (flags & DMA_PREP_INTERRUPT)
566 		updater->dcmd |= PXA_DCMD_ENDIRQEN;
567 	if (sw_desc->cyclic)
568 		sw_desc->hw_desc[sw_desc->nb_desc - 2]->ddadr = sw_desc->first;
569 }
570 
571 static bool is_desc_completed(struct virt_dma_desc *vd)
572 {
573 	struct pxad_desc_sw *sw_desc = to_pxad_sw_desc(vd);
574 	struct pxad_desc_hw *updater =
575 		sw_desc->hw_desc[sw_desc->nb_desc - 1];
576 
577 	return updater->dtadr != (updater->dsadr + 8);
578 }
579 
580 static void pxad_desc_chain(struct virt_dma_desc *vd1,
581 				struct virt_dma_desc *vd2)
582 {
583 	struct pxad_desc_sw *desc1 = to_pxad_sw_desc(vd1);
584 	struct pxad_desc_sw *desc2 = to_pxad_sw_desc(vd2);
585 	dma_addr_t dma_to_chain;
586 
587 	dma_to_chain = desc2->first;
588 	desc1->hw_desc[desc1->nb_desc - 1]->ddadr = dma_to_chain;
589 }
590 
591 static bool pxad_try_hotchain(struct virt_dma_chan *vc,
592 				  struct virt_dma_desc *vd)
593 {
594 	struct virt_dma_desc *vd_last_issued = NULL;
595 	struct pxad_chan *chan = to_pxad_chan(&vc->chan);
596 
597 	/*
598 	 * Attempt to hot chain the tx if the phy is still running. This is
599 	 * considered successful only if either the channel is still running
600 	 * after the chaining, or if the chained transfer is completed after
601 	 * having been hot chained.
602 	 * A change of alignment is not allowed, and forbids hotchaining.
603 	 */
604 	if (is_chan_running(chan)) {
605 		BUG_ON(list_empty(&vc->desc_issued));
606 
607 		if (!is_running_chan_misaligned(chan) &&
608 		    to_pxad_sw_desc(vd)->misaligned)
609 			return false;
610 
611 		vd_last_issued = list_entry(vc->desc_issued.prev,
612 					    struct virt_dma_desc, node);
613 		pxad_desc_chain(vd_last_issued, vd);
614 		if (is_chan_running(chan) || is_desc_completed(vd))
615 			return true;
616 	}
617 
618 	return false;
619 }
620 
621 static unsigned int clear_chan_irq(struct pxad_phy *phy)
622 {
623 	u32 dcsr;
624 	u32 dint = readl(phy->base + DINT);
625 
626 	if (!(dint & BIT(phy->idx)))
627 		return PXA_DCSR_RUN;
628 
629 	/* clear irq */
630 	dcsr = phy_readl_relaxed(phy, DCSR);
631 	phy_writel(phy, dcsr, DCSR);
632 	if ((dcsr & PXA_DCSR_BUSERR) && (phy->vchan))
633 		dev_warn(&phy->vchan->vc.chan.dev->device,
634 			 "%s(chan=%p): PXA_DCSR_BUSERR\n",
635 			 __func__, &phy->vchan);
636 
637 	return dcsr & ~PXA_DCSR_RUN;
638 }
639 
640 static irqreturn_t pxad_chan_handler(int irq, void *dev_id)
641 {
642 	struct pxad_phy *phy = dev_id;
643 	struct pxad_chan *chan = phy->vchan;
644 	struct virt_dma_desc *vd, *tmp;
645 	unsigned int dcsr;
646 	unsigned long flags;
647 	bool vd_completed;
648 	dma_cookie_t last_started = 0;
649 
650 	BUG_ON(!chan);
651 
652 	dcsr = clear_chan_irq(phy);
653 	if (dcsr & PXA_DCSR_RUN)
654 		return IRQ_NONE;
655 
656 	spin_lock_irqsave(&chan->vc.lock, flags);
657 	list_for_each_entry_safe(vd, tmp, &chan->vc.desc_issued, node) {
658 		vd_completed = is_desc_completed(vd);
659 		dev_dbg(&chan->vc.chan.dev->device,
660 			"%s(): checking txd %p[%x]: completed=%d dcsr=0x%x\n",
661 			__func__, vd, vd->tx.cookie, vd_completed,
662 			dcsr);
663 		last_started = vd->tx.cookie;
664 		if (to_pxad_sw_desc(vd)->cyclic) {
665 			vchan_cyclic_callback(vd);
666 			break;
667 		}
668 		if (vd_completed) {
669 			list_del(&vd->node);
670 			vchan_cookie_complete(vd);
671 		} else {
672 			break;
673 		}
674 	}
675 
676 	if (dcsr & PXA_DCSR_BUSERR) {
677 		chan->bus_error = last_started;
678 		phy_disable(phy);
679 	}
680 
681 	if (!chan->bus_error && dcsr & PXA_DCSR_STOPSTATE) {
682 		dev_dbg(&chan->vc.chan.dev->device,
683 		"%s(): channel stopped, submitted_empty=%d issued_empty=%d",
684 			__func__,
685 			list_empty(&chan->vc.desc_submitted),
686 			list_empty(&chan->vc.desc_issued));
687 		phy_writel_relaxed(phy, dcsr & ~PXA_DCSR_STOPIRQEN, DCSR);
688 
689 		if (list_empty(&chan->vc.desc_issued)) {
690 			chan->misaligned =
691 				!list_empty(&chan->vc.desc_submitted);
692 		} else {
693 			vd = list_first_entry(&chan->vc.desc_issued,
694 					      struct virt_dma_desc, node);
695 			pxad_launch_chan(chan, to_pxad_sw_desc(vd));
696 		}
697 	}
698 	spin_unlock_irqrestore(&chan->vc.lock, flags);
699 	wake_up(&chan->wq_state);
700 
701 	return IRQ_HANDLED;
702 }
703 
704 static irqreturn_t pxad_int_handler(int irq, void *dev_id)
705 {
706 	struct pxad_device *pdev = dev_id;
707 	struct pxad_phy *phy;
708 	u32 dint = readl(pdev->base + DINT);
709 	int i, ret = IRQ_NONE;
710 
711 	while (dint) {
712 		i = __ffs(dint);
713 		dint &= (dint - 1);
714 		phy = &pdev->phys[i];
715 		if (pxad_chan_handler(irq, phy) == IRQ_HANDLED)
716 			ret = IRQ_HANDLED;
717 	}
718 
719 	return ret;
720 }
721 
722 static int pxad_alloc_chan_resources(struct dma_chan *dchan)
723 {
724 	struct pxad_chan *chan = to_pxad_chan(dchan);
725 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
726 
727 	if (chan->desc_pool)
728 		return 1;
729 
730 	chan->desc_pool = dma_pool_create(dma_chan_name(dchan),
731 					  pdev->slave.dev,
732 					  sizeof(struct pxad_desc_hw),
733 					  __alignof__(struct pxad_desc_hw),
734 					  0);
735 	if (!chan->desc_pool) {
736 		dev_err(&chan->vc.chan.dev->device,
737 			"%s(): unable to allocate descriptor pool\n",
738 			__func__);
739 		return -ENOMEM;
740 	}
741 
742 	return 1;
743 }
744 
745 static void pxad_free_chan_resources(struct dma_chan *dchan)
746 {
747 	struct pxad_chan *chan = to_pxad_chan(dchan);
748 
749 	vchan_free_chan_resources(&chan->vc);
750 	dma_pool_destroy(chan->desc_pool);
751 	chan->desc_pool = NULL;
752 
753 	chan->drcmr = U32_MAX;
754 	chan->prio = PXAD_PRIO_LOWEST;
755 }
756 
757 static void pxad_free_desc(struct virt_dma_desc *vd)
758 {
759 	int i;
760 	dma_addr_t dma;
761 	struct pxad_desc_sw *sw_desc = to_pxad_sw_desc(vd);
762 
763 	BUG_ON(sw_desc->nb_desc == 0);
764 	for (i = sw_desc->nb_desc - 1; i >= 0; i--) {
765 		if (i > 0)
766 			dma = sw_desc->hw_desc[i - 1]->ddadr;
767 		else
768 			dma = sw_desc->first;
769 		dma_pool_free(sw_desc->desc_pool,
770 			      sw_desc->hw_desc[i], dma);
771 	}
772 	sw_desc->nb_desc = 0;
773 	kfree(sw_desc);
774 }
775 
776 static struct pxad_desc_sw *
777 pxad_alloc_desc(struct pxad_chan *chan, unsigned int nb_hw_desc)
778 {
779 	struct pxad_desc_sw *sw_desc;
780 	dma_addr_t dma;
781 	int i;
782 
783 	sw_desc = kzalloc(sizeof(*sw_desc) +
784 			  nb_hw_desc * sizeof(struct pxad_desc_hw *),
785 			  GFP_NOWAIT);
786 	if (!sw_desc)
787 		return NULL;
788 	sw_desc->desc_pool = chan->desc_pool;
789 
790 	for (i = 0; i < nb_hw_desc; i++) {
791 		sw_desc->hw_desc[i] = dma_pool_alloc(sw_desc->desc_pool,
792 						     GFP_NOWAIT, &dma);
793 		if (!sw_desc->hw_desc[i]) {
794 			dev_err(&chan->vc.chan.dev->device,
795 				"%s(): Couldn't allocate the %dth hw_desc from dma_pool %p\n",
796 				__func__, i, sw_desc->desc_pool);
797 			goto err;
798 		}
799 
800 		if (i == 0)
801 			sw_desc->first = dma;
802 		else
803 			sw_desc->hw_desc[i - 1]->ddadr = dma;
804 		sw_desc->nb_desc++;
805 	}
806 
807 	return sw_desc;
808 err:
809 	pxad_free_desc(&sw_desc->vd);
810 	return NULL;
811 }
812 
813 static dma_cookie_t pxad_tx_submit(struct dma_async_tx_descriptor *tx)
814 {
815 	struct virt_dma_chan *vc = to_virt_chan(tx->chan);
816 	struct pxad_chan *chan = to_pxad_chan(&vc->chan);
817 	struct virt_dma_desc *vd_chained = NULL,
818 		*vd = container_of(tx, struct virt_dma_desc, tx);
819 	dma_cookie_t cookie;
820 	unsigned long flags;
821 
822 	set_updater_desc(to_pxad_sw_desc(vd), tx->flags);
823 
824 	spin_lock_irqsave(&vc->lock, flags);
825 	cookie = dma_cookie_assign(tx);
826 
827 	if (list_empty(&vc->desc_submitted) && pxad_try_hotchain(vc, vd)) {
828 		list_move_tail(&vd->node, &vc->desc_issued);
829 		dev_dbg(&chan->vc.chan.dev->device,
830 			"%s(): txd %p[%x]: submitted (hot linked)\n",
831 			__func__, vd, cookie);
832 		goto out;
833 	}
834 
835 	/*
836 	 * Fallback to placing the tx in the submitted queue
837 	 */
838 	if (!list_empty(&vc->desc_submitted)) {
839 		vd_chained = list_entry(vc->desc_submitted.prev,
840 					struct virt_dma_desc, node);
841 		/*
842 		 * Only chain the descriptors if no new misalignment is
843 		 * introduced. If a new misalignment is chained, let the channel
844 		 * stop, and be relaunched in misalign mode from the irq
845 		 * handler.
846 		 */
847 		if (chan->misaligned || !to_pxad_sw_desc(vd)->misaligned)
848 			pxad_desc_chain(vd_chained, vd);
849 		else
850 			vd_chained = NULL;
851 	}
852 	dev_dbg(&chan->vc.chan.dev->device,
853 		"%s(): txd %p[%x]: submitted (%s linked)\n",
854 		__func__, vd, cookie, vd_chained ? "cold" : "not");
855 	list_move_tail(&vd->node, &vc->desc_submitted);
856 	chan->misaligned |= to_pxad_sw_desc(vd)->misaligned;
857 
858 out:
859 	spin_unlock_irqrestore(&vc->lock, flags);
860 	return cookie;
861 }
862 
863 static void pxad_issue_pending(struct dma_chan *dchan)
864 {
865 	struct pxad_chan *chan = to_pxad_chan(dchan);
866 	struct virt_dma_desc *vd_first;
867 	unsigned long flags;
868 
869 	spin_lock_irqsave(&chan->vc.lock, flags);
870 	if (list_empty(&chan->vc.desc_submitted))
871 		goto out;
872 
873 	vd_first = list_first_entry(&chan->vc.desc_submitted,
874 				    struct virt_dma_desc, node);
875 	dev_dbg(&chan->vc.chan.dev->device,
876 		"%s(): txd %p[%x]", __func__, vd_first, vd_first->tx.cookie);
877 
878 	vchan_issue_pending(&chan->vc);
879 	if (!pxad_try_hotchain(&chan->vc, vd_first))
880 		pxad_launch_chan(chan, to_pxad_sw_desc(vd_first));
881 out:
882 	spin_unlock_irqrestore(&chan->vc.lock, flags);
883 }
884 
885 static inline struct dma_async_tx_descriptor *
886 pxad_tx_prep(struct virt_dma_chan *vc, struct virt_dma_desc *vd,
887 		 unsigned long tx_flags)
888 {
889 	struct dma_async_tx_descriptor *tx;
890 	struct pxad_chan *chan = container_of(vc, struct pxad_chan, vc);
891 
892 	INIT_LIST_HEAD(&vd->node);
893 	tx = vchan_tx_prep(vc, vd, tx_flags);
894 	tx->tx_submit = pxad_tx_submit;
895 	dev_dbg(&chan->vc.chan.dev->device,
896 		"%s(): vc=%p txd=%p[%x] flags=0x%lx\n", __func__,
897 		vc, vd, vd->tx.cookie,
898 		tx_flags);
899 
900 	return tx;
901 }
902 
903 static void pxad_get_config(struct pxad_chan *chan,
904 			    enum dma_transfer_direction dir,
905 			    u32 *dcmd, u32 *dev_src, u32 *dev_dst)
906 {
907 	u32 maxburst = 0, dev_addr = 0;
908 	enum dma_slave_buswidth width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
909 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
910 
911 	*dcmd = 0;
912 	if (dir == DMA_DEV_TO_MEM) {
913 		maxburst = chan->cfg.src_maxburst;
914 		width = chan->cfg.src_addr_width;
915 		dev_addr = chan->cfg.src_addr;
916 		*dev_src = dev_addr;
917 		*dcmd |= PXA_DCMD_INCTRGADDR;
918 		if (chan->drcmr <= pdev->nr_requestors)
919 			*dcmd |= PXA_DCMD_FLOWSRC;
920 	}
921 	if (dir == DMA_MEM_TO_DEV) {
922 		maxburst = chan->cfg.dst_maxburst;
923 		width = chan->cfg.dst_addr_width;
924 		dev_addr = chan->cfg.dst_addr;
925 		*dev_dst = dev_addr;
926 		*dcmd |= PXA_DCMD_INCSRCADDR;
927 		if (chan->drcmr <= pdev->nr_requestors)
928 			*dcmd |= PXA_DCMD_FLOWTRG;
929 	}
930 	if (dir == DMA_MEM_TO_MEM)
931 		*dcmd |= PXA_DCMD_BURST32 | PXA_DCMD_INCTRGADDR |
932 			PXA_DCMD_INCSRCADDR;
933 
934 	dev_dbg(&chan->vc.chan.dev->device,
935 		"%s(): dev_addr=0x%x maxburst=%d width=%d  dir=%d\n",
936 		__func__, dev_addr, maxburst, width, dir);
937 
938 	if (width == DMA_SLAVE_BUSWIDTH_1_BYTE)
939 		*dcmd |= PXA_DCMD_WIDTH1;
940 	else if (width == DMA_SLAVE_BUSWIDTH_2_BYTES)
941 		*dcmd |= PXA_DCMD_WIDTH2;
942 	else if (width == DMA_SLAVE_BUSWIDTH_4_BYTES)
943 		*dcmd |= PXA_DCMD_WIDTH4;
944 
945 	if (maxburst == 8)
946 		*dcmd |= PXA_DCMD_BURST8;
947 	else if (maxburst == 16)
948 		*dcmd |= PXA_DCMD_BURST16;
949 	else if (maxburst == 32)
950 		*dcmd |= PXA_DCMD_BURST32;
951 
952 	/* FIXME: drivers should be ported over to use the filter
953 	 * function. Once that's done, the following two lines can
954 	 * be removed.
955 	 */
956 	if (chan->cfg.slave_id)
957 		chan->drcmr = chan->cfg.slave_id;
958 }
959 
960 static struct dma_async_tx_descriptor *
961 pxad_prep_memcpy(struct dma_chan *dchan,
962 		 dma_addr_t dma_dst, dma_addr_t dma_src,
963 		 size_t len, unsigned long flags)
964 {
965 	struct pxad_chan *chan = to_pxad_chan(dchan);
966 	struct pxad_desc_sw *sw_desc;
967 	struct pxad_desc_hw *hw_desc;
968 	u32 dcmd;
969 	unsigned int i, nb_desc = 0;
970 	size_t copy;
971 
972 	if (!dchan || !len)
973 		return NULL;
974 
975 	dev_dbg(&chan->vc.chan.dev->device,
976 		"%s(): dma_dst=0x%lx dma_src=0x%lx len=%zu flags=%lx\n",
977 		__func__, (unsigned long)dma_dst, (unsigned long)dma_src,
978 		len, flags);
979 	pxad_get_config(chan, DMA_MEM_TO_MEM, &dcmd, NULL, NULL);
980 
981 	nb_desc = DIV_ROUND_UP(len, PDMA_MAX_DESC_BYTES);
982 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
983 	if (!sw_desc)
984 		return NULL;
985 	sw_desc->len = len;
986 
987 	if (!IS_ALIGNED(dma_src, 1 << PDMA_ALIGNMENT) ||
988 	    !IS_ALIGNED(dma_dst, 1 << PDMA_ALIGNMENT))
989 		sw_desc->misaligned = true;
990 
991 	i = 0;
992 	do {
993 		hw_desc = sw_desc->hw_desc[i++];
994 		copy = min_t(size_t, len, PDMA_MAX_DESC_BYTES);
995 		hw_desc->dcmd = dcmd | (PXA_DCMD_LENGTH & copy);
996 		hw_desc->dsadr = dma_src;
997 		hw_desc->dtadr = dma_dst;
998 		len -= copy;
999 		dma_src += copy;
1000 		dma_dst += copy;
1001 	} while (len);
1002 	set_updater_desc(sw_desc, flags);
1003 
1004 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
1005 }
1006 
1007 static struct dma_async_tx_descriptor *
1008 pxad_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
1009 		   unsigned int sg_len, enum dma_transfer_direction dir,
1010 		   unsigned long flags, void *context)
1011 {
1012 	struct pxad_chan *chan = to_pxad_chan(dchan);
1013 	struct pxad_desc_sw *sw_desc;
1014 	size_t len, avail;
1015 	struct scatterlist *sg;
1016 	dma_addr_t dma;
1017 	u32 dcmd, dsadr = 0, dtadr = 0;
1018 	unsigned int nb_desc = 0, i, j = 0;
1019 
1020 	if ((sgl == NULL) || (sg_len == 0))
1021 		return NULL;
1022 
1023 	pxad_get_config(chan, dir, &dcmd, &dsadr, &dtadr);
1024 	dev_dbg(&chan->vc.chan.dev->device,
1025 		"%s(): dir=%d flags=%lx\n", __func__, dir, flags);
1026 
1027 	for_each_sg(sgl, sg, sg_len, i)
1028 		nb_desc += DIV_ROUND_UP(sg_dma_len(sg), PDMA_MAX_DESC_BYTES);
1029 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
1030 	if (!sw_desc)
1031 		return NULL;
1032 
1033 	for_each_sg(sgl, sg, sg_len, i) {
1034 		dma = sg_dma_address(sg);
1035 		avail = sg_dma_len(sg);
1036 		sw_desc->len += avail;
1037 
1038 		do {
1039 			len = min_t(size_t, avail, PDMA_MAX_DESC_BYTES);
1040 			if (dma & 0x7)
1041 				sw_desc->misaligned = true;
1042 
1043 			sw_desc->hw_desc[j]->dcmd =
1044 				dcmd | (PXA_DCMD_LENGTH & len);
1045 			sw_desc->hw_desc[j]->dsadr = dsadr ? dsadr : dma;
1046 			sw_desc->hw_desc[j++]->dtadr = dtadr ? dtadr : dma;
1047 
1048 			dma += len;
1049 			avail -= len;
1050 		} while (avail);
1051 	}
1052 	set_updater_desc(sw_desc, flags);
1053 
1054 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
1055 }
1056 
1057 static struct dma_async_tx_descriptor *
1058 pxad_prep_dma_cyclic(struct dma_chan *dchan,
1059 		     dma_addr_t buf_addr, size_t len, size_t period_len,
1060 		     enum dma_transfer_direction dir, unsigned long flags)
1061 {
1062 	struct pxad_chan *chan = to_pxad_chan(dchan);
1063 	struct pxad_desc_sw *sw_desc;
1064 	struct pxad_desc_hw **phw_desc;
1065 	dma_addr_t dma;
1066 	u32 dcmd, dsadr = 0, dtadr = 0;
1067 	unsigned int nb_desc = 0;
1068 
1069 	if (!dchan || !len || !period_len)
1070 		return NULL;
1071 	if ((dir != DMA_DEV_TO_MEM) && (dir != DMA_MEM_TO_DEV)) {
1072 		dev_err(&chan->vc.chan.dev->device,
1073 			"Unsupported direction for cyclic DMA\n");
1074 		return NULL;
1075 	}
1076 	/* the buffer length must be a multiple of period_len */
1077 	if (len % period_len != 0 || period_len > PDMA_MAX_DESC_BYTES ||
1078 	    !IS_ALIGNED(period_len, 1 << PDMA_ALIGNMENT))
1079 		return NULL;
1080 
1081 	pxad_get_config(chan, dir, &dcmd, &dsadr, &dtadr);
1082 	dcmd |= PXA_DCMD_ENDIRQEN | (PXA_DCMD_LENGTH & period_len);
1083 	dev_dbg(&chan->vc.chan.dev->device,
1084 		"%s(): buf_addr=0x%lx len=%zu period=%zu dir=%d flags=%lx\n",
1085 		__func__, (unsigned long)buf_addr, len, period_len, dir, flags);
1086 
1087 	nb_desc = DIV_ROUND_UP(period_len, PDMA_MAX_DESC_BYTES);
1088 	nb_desc *= DIV_ROUND_UP(len, period_len);
1089 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
1090 	if (!sw_desc)
1091 		return NULL;
1092 	sw_desc->cyclic = true;
1093 	sw_desc->len = len;
1094 
1095 	phw_desc = sw_desc->hw_desc;
1096 	dma = buf_addr;
1097 	do {
1098 		phw_desc[0]->dsadr = dsadr ? dsadr : dma;
1099 		phw_desc[0]->dtadr = dtadr ? dtadr : dma;
1100 		phw_desc[0]->dcmd = dcmd;
1101 		phw_desc++;
1102 		dma += period_len;
1103 		len -= period_len;
1104 	} while (len);
1105 	set_updater_desc(sw_desc, flags);
1106 
1107 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
1108 }
1109 
1110 static int pxad_config(struct dma_chan *dchan,
1111 		       struct dma_slave_config *cfg)
1112 {
1113 	struct pxad_chan *chan = to_pxad_chan(dchan);
1114 
1115 	if (!dchan)
1116 		return -EINVAL;
1117 
1118 	chan->cfg = *cfg;
1119 	return 0;
1120 }
1121 
1122 static int pxad_terminate_all(struct dma_chan *dchan)
1123 {
1124 	struct pxad_chan *chan = to_pxad_chan(dchan);
1125 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
1126 	struct virt_dma_desc *vd = NULL;
1127 	unsigned long flags;
1128 	struct pxad_phy *phy;
1129 	LIST_HEAD(head);
1130 
1131 	dev_dbg(&chan->vc.chan.dev->device,
1132 		"%s(): vchan %p: terminate all\n", __func__, &chan->vc);
1133 
1134 	spin_lock_irqsave(&chan->vc.lock, flags);
1135 	vchan_get_all_descriptors(&chan->vc, &head);
1136 
1137 	list_for_each_entry(vd, &head, node) {
1138 		dev_dbg(&chan->vc.chan.dev->device,
1139 			"%s(): cancelling txd %p[%x] (completed=%d)", __func__,
1140 			vd, vd->tx.cookie, is_desc_completed(vd));
1141 	}
1142 
1143 	phy = chan->phy;
1144 	if (phy) {
1145 		phy_disable(chan->phy);
1146 		pxad_free_phy(chan);
1147 		chan->phy = NULL;
1148 		spin_lock(&pdev->phy_lock);
1149 		phy->vchan = NULL;
1150 		spin_unlock(&pdev->phy_lock);
1151 	}
1152 	spin_unlock_irqrestore(&chan->vc.lock, flags);
1153 	vchan_dma_desc_free_list(&chan->vc, &head);
1154 
1155 	return 0;
1156 }
1157 
1158 static unsigned int pxad_residue(struct pxad_chan *chan,
1159 				 dma_cookie_t cookie)
1160 {
1161 	struct virt_dma_desc *vd = NULL;
1162 	struct pxad_desc_sw *sw_desc = NULL;
1163 	struct pxad_desc_hw *hw_desc = NULL;
1164 	u32 curr, start, len, end, residue = 0;
1165 	unsigned long flags;
1166 	bool passed = false;
1167 	int i;
1168 
1169 	/*
1170 	 * If the channel does not have a phy pointer anymore, it has already
1171 	 * been completed. Therefore, its residue is 0.
1172 	 */
1173 	if (!chan->phy)
1174 		return 0;
1175 
1176 	spin_lock_irqsave(&chan->vc.lock, flags);
1177 
1178 	vd = vchan_find_desc(&chan->vc, cookie);
1179 	if (!vd)
1180 		goto out;
1181 
1182 	sw_desc = to_pxad_sw_desc(vd);
1183 	if (sw_desc->hw_desc[0]->dcmd & PXA_DCMD_INCSRCADDR)
1184 		curr = phy_readl_relaxed(chan->phy, DSADR);
1185 	else
1186 		curr = phy_readl_relaxed(chan->phy, DTADR);
1187 
1188 	/*
1189 	 * curr has to be actually read before checking descriptor
1190 	 * completion, so that a curr inside a status updater
1191 	 * descriptor implies the following test returns true, and
1192 	 * preventing reordering of curr load and the test.
1193 	 */
1194 	rmb();
1195 	if (is_desc_completed(vd))
1196 		goto out;
1197 
1198 	for (i = 0; i < sw_desc->nb_desc - 1; i++) {
1199 		hw_desc = sw_desc->hw_desc[i];
1200 		if (sw_desc->hw_desc[0]->dcmd & PXA_DCMD_INCSRCADDR)
1201 			start = hw_desc->dsadr;
1202 		else
1203 			start = hw_desc->dtadr;
1204 		len = hw_desc->dcmd & PXA_DCMD_LENGTH;
1205 		end = start + len;
1206 
1207 		/*
1208 		 * 'passed' will be latched once we found the descriptor
1209 		 * which lies inside the boundaries of the curr
1210 		 * pointer. All descriptors that occur in the list
1211 		 * _after_ we found that partially handled descriptor
1212 		 * are still to be processed and are hence added to the
1213 		 * residual bytes counter.
1214 		 */
1215 
1216 		if (passed) {
1217 			residue += len;
1218 		} else if (curr >= start && curr <= end) {
1219 			residue += end - curr;
1220 			passed = true;
1221 		}
1222 	}
1223 	if (!passed)
1224 		residue = sw_desc->len;
1225 
1226 out:
1227 	spin_unlock_irqrestore(&chan->vc.lock, flags);
1228 	dev_dbg(&chan->vc.chan.dev->device,
1229 		"%s(): txd %p[%x] sw_desc=%p: %d\n",
1230 		__func__, vd, cookie, sw_desc, residue);
1231 	return residue;
1232 }
1233 
1234 static enum dma_status pxad_tx_status(struct dma_chan *dchan,
1235 				      dma_cookie_t cookie,
1236 				      struct dma_tx_state *txstate)
1237 {
1238 	struct pxad_chan *chan = to_pxad_chan(dchan);
1239 	enum dma_status ret;
1240 
1241 	if (cookie == chan->bus_error)
1242 		return DMA_ERROR;
1243 
1244 	ret = dma_cookie_status(dchan, cookie, txstate);
1245 	if (likely(txstate && (ret != DMA_ERROR)))
1246 		dma_set_residue(txstate, pxad_residue(chan, cookie));
1247 
1248 	return ret;
1249 }
1250 
1251 static void pxad_synchronize(struct dma_chan *dchan)
1252 {
1253 	struct pxad_chan *chan = to_pxad_chan(dchan);
1254 
1255 	wait_event(chan->wq_state, !is_chan_running(chan));
1256 	vchan_synchronize(&chan->vc);
1257 }
1258 
1259 static void pxad_free_channels(struct dma_device *dmadev)
1260 {
1261 	struct pxad_chan *c, *cn;
1262 
1263 	list_for_each_entry_safe(c, cn, &dmadev->channels,
1264 				 vc.chan.device_node) {
1265 		list_del(&c->vc.chan.device_node);
1266 		tasklet_kill(&c->vc.task);
1267 	}
1268 }
1269 
1270 static int pxad_remove(struct platform_device *op)
1271 {
1272 	struct pxad_device *pdev = platform_get_drvdata(op);
1273 
1274 	pxad_cleanup_debugfs(pdev);
1275 	pxad_free_channels(&pdev->slave);
1276 	return 0;
1277 }
1278 
1279 static int pxad_init_phys(struct platform_device *op,
1280 			  struct pxad_device *pdev,
1281 			  unsigned int nb_phy_chans)
1282 {
1283 	int irq0, irq, nr_irq = 0, i, ret;
1284 	struct pxad_phy *phy;
1285 
1286 	irq0 = platform_get_irq(op, 0);
1287 	if (irq0 < 0)
1288 		return irq0;
1289 
1290 	pdev->phys = devm_kcalloc(&op->dev, nb_phy_chans,
1291 				  sizeof(pdev->phys[0]), GFP_KERNEL);
1292 	if (!pdev->phys)
1293 		return -ENOMEM;
1294 
1295 	for (i = 0; i < nb_phy_chans; i++)
1296 		if (platform_get_irq(op, i) > 0)
1297 			nr_irq++;
1298 
1299 	for (i = 0; i < nb_phy_chans; i++) {
1300 		phy = &pdev->phys[i];
1301 		phy->base = pdev->base;
1302 		phy->idx = i;
1303 		irq = platform_get_irq(op, i);
1304 		if ((nr_irq > 1) && (irq > 0))
1305 			ret = devm_request_irq(&op->dev, irq,
1306 					       pxad_chan_handler,
1307 					       IRQF_SHARED, "pxa-dma", phy);
1308 		if ((nr_irq == 1) && (i == 0))
1309 			ret = devm_request_irq(&op->dev, irq0,
1310 					       pxad_int_handler,
1311 					       IRQF_SHARED, "pxa-dma", pdev);
1312 		if (ret) {
1313 			dev_err(pdev->slave.dev,
1314 				"%s(): can't request irq %d:%d\n", __func__,
1315 				irq, ret);
1316 			return ret;
1317 		}
1318 	}
1319 
1320 	return 0;
1321 }
1322 
1323 static const struct of_device_id pxad_dt_ids[] = {
1324 	{ .compatible = "marvell,pdma-1.0", },
1325 	{}
1326 };
1327 MODULE_DEVICE_TABLE(of, pxad_dt_ids);
1328 
1329 static struct dma_chan *pxad_dma_xlate(struct of_phandle_args *dma_spec,
1330 					   struct of_dma *ofdma)
1331 {
1332 	struct pxad_device *d = ofdma->of_dma_data;
1333 	struct dma_chan *chan;
1334 
1335 	chan = dma_get_any_slave_channel(&d->slave);
1336 	if (!chan)
1337 		return NULL;
1338 
1339 	to_pxad_chan(chan)->drcmr = dma_spec->args[0];
1340 	to_pxad_chan(chan)->prio = dma_spec->args[1];
1341 
1342 	return chan;
1343 }
1344 
1345 static int pxad_init_dmadev(struct platform_device *op,
1346 			    struct pxad_device *pdev,
1347 			    unsigned int nr_phy_chans,
1348 			    unsigned int nr_requestors)
1349 {
1350 	int ret;
1351 	unsigned int i;
1352 	struct pxad_chan *c;
1353 
1354 	pdev->nr_chans = nr_phy_chans;
1355 	pdev->nr_requestors = nr_requestors;
1356 	INIT_LIST_HEAD(&pdev->slave.channels);
1357 	pdev->slave.device_alloc_chan_resources = pxad_alloc_chan_resources;
1358 	pdev->slave.device_free_chan_resources = pxad_free_chan_resources;
1359 	pdev->slave.device_tx_status = pxad_tx_status;
1360 	pdev->slave.device_issue_pending = pxad_issue_pending;
1361 	pdev->slave.device_config = pxad_config;
1362 	pdev->slave.device_synchronize = pxad_synchronize;
1363 	pdev->slave.device_terminate_all = pxad_terminate_all;
1364 
1365 	if (op->dev.coherent_dma_mask)
1366 		dma_set_mask(&op->dev, op->dev.coherent_dma_mask);
1367 	else
1368 		dma_set_mask(&op->dev, DMA_BIT_MASK(32));
1369 
1370 	ret = pxad_init_phys(op, pdev, nr_phy_chans);
1371 	if (ret)
1372 		return ret;
1373 
1374 	for (i = 0; i < nr_phy_chans; i++) {
1375 		c = devm_kzalloc(&op->dev, sizeof(*c), GFP_KERNEL);
1376 		if (!c)
1377 			return -ENOMEM;
1378 
1379 		c->drcmr = U32_MAX;
1380 		c->prio = PXAD_PRIO_LOWEST;
1381 		c->vc.desc_free = pxad_free_desc;
1382 		vchan_init(&c->vc, &pdev->slave);
1383 		init_waitqueue_head(&c->wq_state);
1384 	}
1385 
1386 	return dmaenginem_async_device_register(&pdev->slave);
1387 }
1388 
1389 static int pxad_probe(struct platform_device *op)
1390 {
1391 	struct pxad_device *pdev;
1392 	const struct of_device_id *of_id;
1393 	const struct dma_slave_map *slave_map = NULL;
1394 	struct mmp_dma_platdata *pdata = dev_get_platdata(&op->dev);
1395 	struct resource *iores;
1396 	int ret, dma_channels = 0, nb_requestors = 0, slave_map_cnt = 0;
1397 	const enum dma_slave_buswidth widths =
1398 		DMA_SLAVE_BUSWIDTH_1_BYTE   | DMA_SLAVE_BUSWIDTH_2_BYTES |
1399 		DMA_SLAVE_BUSWIDTH_4_BYTES;
1400 
1401 	pdev = devm_kzalloc(&op->dev, sizeof(*pdev), GFP_KERNEL);
1402 	if (!pdev)
1403 		return -ENOMEM;
1404 
1405 	spin_lock_init(&pdev->phy_lock);
1406 
1407 	iores = platform_get_resource(op, IORESOURCE_MEM, 0);
1408 	pdev->base = devm_ioremap_resource(&op->dev, iores);
1409 	if (IS_ERR(pdev->base))
1410 		return PTR_ERR(pdev->base);
1411 
1412 	of_id = of_match_device(pxad_dt_ids, &op->dev);
1413 	if (of_id) {
1414 		of_property_read_u32(op->dev.of_node, "#dma-channels",
1415 				     &dma_channels);
1416 		ret = of_property_read_u32(op->dev.of_node, "#dma-requests",
1417 					   &nb_requestors);
1418 		if (ret) {
1419 			dev_warn(pdev->slave.dev,
1420 				 "#dma-requests set to default 32 as missing in OF: %d",
1421 				 ret);
1422 			nb_requestors = 32;
1423 		}
1424 	} else if (pdata && pdata->dma_channels) {
1425 		dma_channels = pdata->dma_channels;
1426 		nb_requestors = pdata->nb_requestors;
1427 		slave_map = pdata->slave_map;
1428 		slave_map_cnt = pdata->slave_map_cnt;
1429 	} else {
1430 		dma_channels = 32;	/* default 32 channel */
1431 	}
1432 
1433 	dma_cap_set(DMA_SLAVE, pdev->slave.cap_mask);
1434 	dma_cap_set(DMA_MEMCPY, pdev->slave.cap_mask);
1435 	dma_cap_set(DMA_CYCLIC, pdev->slave.cap_mask);
1436 	dma_cap_set(DMA_PRIVATE, pdev->slave.cap_mask);
1437 	pdev->slave.device_prep_dma_memcpy = pxad_prep_memcpy;
1438 	pdev->slave.device_prep_slave_sg = pxad_prep_slave_sg;
1439 	pdev->slave.device_prep_dma_cyclic = pxad_prep_dma_cyclic;
1440 	pdev->slave.filter.map = slave_map;
1441 	pdev->slave.filter.mapcnt = slave_map_cnt;
1442 	pdev->slave.filter.fn = pxad_filter_fn;
1443 
1444 	pdev->slave.copy_align = PDMA_ALIGNMENT;
1445 	pdev->slave.src_addr_widths = widths;
1446 	pdev->slave.dst_addr_widths = widths;
1447 	pdev->slave.directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
1448 	pdev->slave.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
1449 	pdev->slave.descriptor_reuse = true;
1450 
1451 	pdev->slave.dev = &op->dev;
1452 	ret = pxad_init_dmadev(op, pdev, dma_channels, nb_requestors);
1453 	if (ret) {
1454 		dev_err(pdev->slave.dev, "unable to register\n");
1455 		return ret;
1456 	}
1457 
1458 	if (op->dev.of_node) {
1459 		/* Device-tree DMA controller registration */
1460 		ret = of_dma_controller_register(op->dev.of_node,
1461 						 pxad_dma_xlate, pdev);
1462 		if (ret < 0) {
1463 			dev_err(pdev->slave.dev,
1464 				"of_dma_controller_register failed\n");
1465 			return ret;
1466 		}
1467 	}
1468 
1469 	platform_set_drvdata(op, pdev);
1470 	pxad_init_debugfs(pdev);
1471 	dev_info(pdev->slave.dev, "initialized %d channels on %d requestors\n",
1472 		 dma_channels, nb_requestors);
1473 	return 0;
1474 }
1475 
1476 static const struct platform_device_id pxad_id_table[] = {
1477 	{ "pxa-dma", },
1478 	{ },
1479 };
1480 
1481 static struct platform_driver pxad_driver = {
1482 	.driver		= {
1483 		.name	= "pxa-dma",
1484 		.of_match_table = pxad_dt_ids,
1485 	},
1486 	.id_table	= pxad_id_table,
1487 	.probe		= pxad_probe,
1488 	.remove		= pxad_remove,
1489 };
1490 
1491 static bool pxad_filter_fn(struct dma_chan *chan, void *param)
1492 {
1493 	struct pxad_chan *c = to_pxad_chan(chan);
1494 	struct pxad_param *p = param;
1495 
1496 	if (chan->device->dev->driver != &pxad_driver.driver)
1497 		return false;
1498 
1499 	c->drcmr = p->drcmr;
1500 	c->prio = p->prio;
1501 
1502 	return true;
1503 }
1504 
1505 module_platform_driver(pxad_driver);
1506 
1507 MODULE_DESCRIPTION("Marvell PXA Peripheral DMA Driver");
1508 MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");
1509 MODULE_LICENSE("GPL v2");
1510