xref: /openbmc/linux/drivers/dma/pxa_dma.c (revision 6189f1b0)
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/dma/pxa-dma.h>
25 
26 #include "dmaengine.h"
27 #include "virt-dma.h"
28 
29 #define DCSR(n)		(0x0000 + ((n) << 2))
30 #define DALGN(n)	0x00a0
31 #define DINT		0x00f0
32 #define DDADR(n)	(0x0200 + ((n) << 4))
33 #define DSADR(n)	(0x0204 + ((n) << 4))
34 #define DTADR(n)	(0x0208 + ((n) << 4))
35 #define DCMD(n)		(0x020c + ((n) << 4))
36 
37 #define PXA_DCSR_RUN		BIT(31)	/* Run Bit (read / write) */
38 #define PXA_DCSR_NODESC		BIT(30)	/* No-Descriptor Fetch (read / write) */
39 #define PXA_DCSR_STOPIRQEN	BIT(29)	/* Stop Interrupt Enable (R/W) */
40 #define PXA_DCSR_REQPEND	BIT(8)	/* Request Pending (read-only) */
41 #define PXA_DCSR_STOPSTATE	BIT(3)	/* Stop State (read-only) */
42 #define PXA_DCSR_ENDINTR	BIT(2)	/* End Interrupt (read / write) */
43 #define PXA_DCSR_STARTINTR	BIT(1)	/* Start Interrupt (read / write) */
44 #define PXA_DCSR_BUSERR		BIT(0)	/* Bus Error Interrupt (read / write) */
45 
46 #define PXA_DCSR_EORIRQEN	BIT(28)	/* End of Receive IRQ Enable (R/W) */
47 #define PXA_DCSR_EORJMPEN	BIT(27)	/* Jump to next descriptor on EOR */
48 #define PXA_DCSR_EORSTOPEN	BIT(26)	/* STOP on an EOR */
49 #define PXA_DCSR_SETCMPST	BIT(25)	/* Set Descriptor Compare Status */
50 #define PXA_DCSR_CLRCMPST	BIT(24)	/* Clear Descriptor Compare Status */
51 #define PXA_DCSR_CMPST		BIT(10)	/* The Descriptor Compare Status */
52 #define PXA_DCSR_EORINTR	BIT(9)	/* The end of Receive */
53 
54 #define DRCMR_MAPVLD	BIT(7)	/* Map Valid (read / write) */
55 #define DRCMR_CHLNUM	0x1f	/* mask for Channel Number (read / write) */
56 
57 #define DDADR_DESCADDR	0xfffffff0	/* Address of next descriptor (mask) */
58 #define DDADR_STOP	BIT(0)	/* Stop (read / write) */
59 
60 #define PXA_DCMD_INCSRCADDR	BIT(31)	/* Source Address Increment Setting. */
61 #define PXA_DCMD_INCTRGADDR	BIT(30)	/* Target Address Increment Setting. */
62 #define PXA_DCMD_FLOWSRC	BIT(29)	/* Flow Control by the source. */
63 #define PXA_DCMD_FLOWTRG	BIT(28)	/* Flow Control by the target. */
64 #define PXA_DCMD_STARTIRQEN	BIT(22)	/* Start Interrupt Enable */
65 #define PXA_DCMD_ENDIRQEN	BIT(21)	/* End Interrupt Enable */
66 #define PXA_DCMD_ENDIAN		BIT(18)	/* Device Endian-ness. */
67 #define PXA_DCMD_BURST8		(1 << 16)	/* 8 byte burst */
68 #define PXA_DCMD_BURST16	(2 << 16)	/* 16 byte burst */
69 #define PXA_DCMD_BURST32	(3 << 16)	/* 32 byte burst */
70 #define PXA_DCMD_WIDTH1		(1 << 14)	/* 1 byte width */
71 #define PXA_DCMD_WIDTH2		(2 << 14)	/* 2 byte width (HalfWord) */
72 #define PXA_DCMD_WIDTH4		(3 << 14)	/* 4 byte width (Word) */
73 #define PXA_DCMD_LENGTH		0x01fff		/* length mask (max = 8K - 1) */
74 
75 #define PDMA_ALIGNMENT		3
76 #define PDMA_MAX_DESC_BYTES	(PXA_DCMD_LENGTH & ~((1 << PDMA_ALIGNMENT) - 1))
77 
78 struct pxad_desc_hw {
79 	u32 ddadr;	/* Points to the next descriptor + flags */
80 	u32 dsadr;	/* DSADR value for the current transfer */
81 	u32 dtadr;	/* DTADR value for the current transfer */
82 	u32 dcmd;	/* DCMD value for the current transfer */
83 } __aligned(16);
84 
85 struct pxad_desc_sw {
86 	struct virt_dma_desc	vd;		/* Virtual descriptor */
87 	int			nb_desc;	/* Number of hw. descriptors */
88 	size_t			len;		/* Number of bytes xfered */
89 	dma_addr_t		first;		/* First descriptor's addr */
90 
91 	/* At least one descriptor has an src/dst address not multiple of 8 */
92 	bool			misaligned;
93 	bool			cyclic;
94 	struct dma_pool		*desc_pool;	/* Channel's used allocator */
95 
96 	struct pxad_desc_hw	*hw_desc[];	/* DMA coherent descriptors */
97 };
98 
99 struct pxad_phy {
100 	int			idx;
101 	void __iomem		*base;
102 	struct pxad_chan	*vchan;
103 };
104 
105 struct pxad_chan {
106 	struct virt_dma_chan	vc;		/* Virtual channel */
107 	u32			drcmr;		/* Requestor of the channel */
108 	enum pxad_chan_prio	prio;		/* Required priority of phy */
109 	/*
110 	 * At least one desc_sw in submitted or issued transfers on this channel
111 	 * has one address such as: addr % 8 != 0. This implies the DALGN
112 	 * setting on the phy.
113 	 */
114 	bool			misaligned;
115 	struct dma_slave_config	cfg;		/* Runtime config */
116 
117 	/* protected by vc->lock */
118 	struct pxad_phy		*phy;
119 	struct dma_pool		*desc_pool;	/* Descriptors pool */
120 };
121 
122 struct pxad_device {
123 	struct dma_device		slave;
124 	int				nr_chans;
125 	void __iomem			*base;
126 	struct pxad_phy			*phys;
127 	spinlock_t			phy_lock;	/* Phy association */
128 #ifdef CONFIG_DEBUG_FS
129 	struct dentry			*dbgfs_root;
130 	struct dentry			*dbgfs_state;
131 	struct dentry			**dbgfs_chan;
132 #endif
133 };
134 
135 #define tx_to_pxad_desc(tx)					\
136 	container_of(tx, struct pxad_desc_sw, async_tx)
137 #define to_pxad_chan(dchan)					\
138 	container_of(dchan, struct pxad_chan, vc.chan)
139 #define to_pxad_dev(dmadev)					\
140 	container_of(dmadev, struct pxad_device, slave)
141 #define to_pxad_sw_desc(_vd)				\
142 	container_of((_vd), struct pxad_desc_sw, vd)
143 
144 #define _phy_readl_relaxed(phy, _reg)					\
145 	readl_relaxed((phy)->base + _reg((phy)->idx))
146 #define phy_readl_relaxed(phy, _reg)					\
147 	({								\
148 		u32 _v;							\
149 		_v = readl_relaxed((phy)->base + _reg((phy)->idx));	\
150 		dev_vdbg(&phy->vchan->vc.chan.dev->device,		\
151 			 "%s(): readl(%s): 0x%08x\n", __func__, #_reg,	\
152 			  _v);						\
153 		_v;							\
154 	})
155 #define phy_writel(phy, val, _reg)					\
156 	do {								\
157 		writel((val), (phy)->base + _reg((phy)->idx));		\
158 		dev_vdbg(&phy->vchan->vc.chan.dev->device,		\
159 			 "%s(): writel(0x%08x, %s)\n",			\
160 			 __func__, (u32)(val), #_reg);			\
161 	} while (0)
162 #define phy_writel_relaxed(phy, val, _reg)				\
163 	do {								\
164 		writel_relaxed((val), (phy)->base + _reg((phy)->idx));	\
165 		dev_vdbg(&phy->vchan->vc.chan.dev->device,		\
166 			 "%s(): writel_relaxed(0x%08x, %s)\n",		\
167 			 __func__, (u32)(val), #_reg);			\
168 	} while (0)
169 
170 static unsigned int pxad_drcmr(unsigned int line)
171 {
172 	if (line < 64)
173 		return 0x100 + line * 4;
174 	return 0x1000 + line * 4;
175 }
176 
177 /*
178  * Debug fs
179  */
180 #ifdef CONFIG_DEBUG_FS
181 #include <linux/debugfs.h>
182 #include <linux/uaccess.h>
183 #include <linux/seq_file.h>
184 
185 static int dbg_show_requester_chan(struct seq_file *s, void *p)
186 {
187 	int pos = 0;
188 	struct pxad_phy *phy = s->private;
189 	int i;
190 	u32 drcmr;
191 
192 	pos += seq_printf(s, "DMA channel %d requester :\n", phy->idx);
193 	for (i = 0; i < 70; i++) {
194 		drcmr = readl_relaxed(phy->base + pxad_drcmr(i));
195 		if ((drcmr & DRCMR_CHLNUM) == phy->idx)
196 			pos += seq_printf(s, "\tRequester %d (MAPVLD=%d)\n", i,
197 					  !!(drcmr & DRCMR_MAPVLD));
198 	}
199 	return pos;
200 }
201 
202 static inline int dbg_burst_from_dcmd(u32 dcmd)
203 {
204 	int burst = (dcmd >> 16) & 0x3;
205 
206 	return burst ? 4 << burst : 0;
207 }
208 
209 static int is_phys_valid(unsigned long addr)
210 {
211 	return pfn_valid(__phys_to_pfn(addr));
212 }
213 
214 #define PXA_DCSR_STR(flag) (dcsr & PXA_DCSR_##flag ? #flag" " : "")
215 #define PXA_DCMD_STR(flag) (dcmd & PXA_DCMD_##flag ? #flag" " : "")
216 
217 static int dbg_show_descriptors(struct seq_file *s, void *p)
218 {
219 	struct pxad_phy *phy = s->private;
220 	int i, max_show = 20, burst, width;
221 	u32 dcmd;
222 	unsigned long phys_desc, ddadr;
223 	struct pxad_desc_hw *desc;
224 
225 	phys_desc = ddadr = _phy_readl_relaxed(phy, DDADR);
226 
227 	seq_printf(s, "DMA channel %d descriptors :\n", phy->idx);
228 	seq_printf(s, "[%03d] First descriptor unknown\n", 0);
229 	for (i = 1; i < max_show && is_phys_valid(phys_desc); i++) {
230 		desc = phys_to_virt(phys_desc);
231 		dcmd = desc->dcmd;
232 		burst = dbg_burst_from_dcmd(dcmd);
233 		width = (1 << ((dcmd >> 14) & 0x3)) >> 1;
234 
235 		seq_printf(s, "[%03d] Desc at %08lx(virt %p)\n",
236 			   i, phys_desc, desc);
237 		seq_printf(s, "\tDDADR = %08x\n", desc->ddadr);
238 		seq_printf(s, "\tDSADR = %08x\n", desc->dsadr);
239 		seq_printf(s, "\tDTADR = %08x\n", desc->dtadr);
240 		seq_printf(s, "\tDCMD  = %08x (%s%s%s%s%s%s%sburst=%d width=%d len=%d)\n",
241 			   dcmd,
242 			   PXA_DCMD_STR(INCSRCADDR), PXA_DCMD_STR(INCTRGADDR),
243 			   PXA_DCMD_STR(FLOWSRC), PXA_DCMD_STR(FLOWTRG),
244 			   PXA_DCMD_STR(STARTIRQEN), PXA_DCMD_STR(ENDIRQEN),
245 			   PXA_DCMD_STR(ENDIAN), burst, width,
246 			   dcmd & PXA_DCMD_LENGTH);
247 		phys_desc = desc->ddadr;
248 	}
249 	if (i == max_show)
250 		seq_printf(s, "[%03d] Desc at %08lx ... max display reached\n",
251 			   i, phys_desc);
252 	else
253 		seq_printf(s, "[%03d] Desc at %08lx is %s\n",
254 			   i, phys_desc, phys_desc == DDADR_STOP ?
255 			   "DDADR_STOP" : "invalid");
256 
257 	return 0;
258 }
259 
260 static int dbg_show_chan_state(struct seq_file *s, void *p)
261 {
262 	struct pxad_phy *phy = s->private;
263 	u32 dcsr, dcmd;
264 	int burst, width;
265 	static const char * const str_prio[] = {
266 		"high", "normal", "low", "invalid"
267 	};
268 
269 	dcsr = _phy_readl_relaxed(phy, DCSR);
270 	dcmd = _phy_readl_relaxed(phy, DCMD);
271 	burst = dbg_burst_from_dcmd(dcmd);
272 	width = (1 << ((dcmd >> 14) & 0x3)) >> 1;
273 
274 	seq_printf(s, "DMA channel %d\n", phy->idx);
275 	seq_printf(s, "\tPriority : %s\n",
276 			  str_prio[(phy->idx & 0xf) / 4]);
277 	seq_printf(s, "\tUnaligned transfer bit: %s\n",
278 			  _phy_readl_relaxed(phy, DALGN) & BIT(phy->idx) ?
279 			  "yes" : "no");
280 	seq_printf(s, "\tDCSR  = %08x (%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s)\n",
281 		   dcsr, PXA_DCSR_STR(RUN), PXA_DCSR_STR(NODESC),
282 		   PXA_DCSR_STR(STOPIRQEN), PXA_DCSR_STR(EORIRQEN),
283 		   PXA_DCSR_STR(EORJMPEN), PXA_DCSR_STR(EORSTOPEN),
284 		   PXA_DCSR_STR(SETCMPST), PXA_DCSR_STR(CLRCMPST),
285 		   PXA_DCSR_STR(CMPST), PXA_DCSR_STR(EORINTR),
286 		   PXA_DCSR_STR(REQPEND), PXA_DCSR_STR(STOPSTATE),
287 		   PXA_DCSR_STR(ENDINTR), PXA_DCSR_STR(STARTINTR),
288 		   PXA_DCSR_STR(BUSERR));
289 
290 	seq_printf(s, "\tDCMD  = %08x (%s%s%s%s%s%s%sburst=%d width=%d len=%d)\n",
291 		   dcmd,
292 		   PXA_DCMD_STR(INCSRCADDR), PXA_DCMD_STR(INCTRGADDR),
293 		   PXA_DCMD_STR(FLOWSRC), PXA_DCMD_STR(FLOWTRG),
294 		   PXA_DCMD_STR(STARTIRQEN), PXA_DCMD_STR(ENDIRQEN),
295 		   PXA_DCMD_STR(ENDIAN), burst, width, dcmd & PXA_DCMD_LENGTH);
296 	seq_printf(s, "\tDSADR = %08x\n", _phy_readl_relaxed(phy, DSADR));
297 	seq_printf(s, "\tDTADR = %08x\n", _phy_readl_relaxed(phy, DTADR));
298 	seq_printf(s, "\tDDADR = %08x\n", _phy_readl_relaxed(phy, DDADR));
299 
300 	return 0;
301 }
302 
303 static int dbg_show_state(struct seq_file *s, void *p)
304 {
305 	struct pxad_device *pdev = s->private;
306 
307 	/* basic device status */
308 	seq_puts(s, "DMA engine status\n");
309 	seq_printf(s, "\tChannel number: %d\n", pdev->nr_chans);
310 
311 	return 0;
312 }
313 
314 #define DBGFS_FUNC_DECL(name) \
315 static int dbg_open_##name(struct inode *inode, struct file *file) \
316 { \
317 	return single_open(file, dbg_show_##name, inode->i_private); \
318 } \
319 static const struct file_operations dbg_fops_##name = { \
320 	.owner		= THIS_MODULE, \
321 	.open		= dbg_open_##name, \
322 	.llseek		= seq_lseek, \
323 	.read		= seq_read, \
324 	.release	= single_release, \
325 }
326 
327 DBGFS_FUNC_DECL(state);
328 DBGFS_FUNC_DECL(chan_state);
329 DBGFS_FUNC_DECL(descriptors);
330 DBGFS_FUNC_DECL(requester_chan);
331 
332 static struct dentry *pxad_dbg_alloc_chan(struct pxad_device *pdev,
333 					     int ch, struct dentry *chandir)
334 {
335 	char chan_name[11];
336 	struct dentry *chan, *chan_state = NULL, *chan_descr = NULL;
337 	struct dentry *chan_reqs = NULL;
338 	void *dt;
339 
340 	scnprintf(chan_name, sizeof(chan_name), "%d", ch);
341 	chan = debugfs_create_dir(chan_name, chandir);
342 	dt = (void *)&pdev->phys[ch];
343 
344 	if (chan)
345 		chan_state = debugfs_create_file("state", 0400, chan, dt,
346 						 &dbg_fops_chan_state);
347 	if (chan_state)
348 		chan_descr = debugfs_create_file("descriptors", 0400, chan, dt,
349 						 &dbg_fops_descriptors);
350 	if (chan_descr)
351 		chan_reqs = debugfs_create_file("requesters", 0400, chan, dt,
352 						&dbg_fops_requester_chan);
353 	if (!chan_reqs)
354 		goto err_state;
355 
356 	return chan;
357 
358 err_state:
359 	debugfs_remove_recursive(chan);
360 	return NULL;
361 }
362 
363 static void pxad_init_debugfs(struct pxad_device *pdev)
364 {
365 	int i;
366 	struct dentry *chandir;
367 
368 	pdev->dbgfs_root = debugfs_create_dir(dev_name(pdev->slave.dev), NULL);
369 	if (IS_ERR(pdev->dbgfs_root) || !pdev->dbgfs_root)
370 		goto err_root;
371 
372 	pdev->dbgfs_state = debugfs_create_file("state", 0400, pdev->dbgfs_root,
373 						pdev, &dbg_fops_state);
374 	if (!pdev->dbgfs_state)
375 		goto err_state;
376 
377 	pdev->dbgfs_chan =
378 		kmalloc_array(pdev->nr_chans, sizeof(*pdev->dbgfs_state),
379 			      GFP_KERNEL);
380 	if (!pdev->dbgfs_chan)
381 		goto err_alloc;
382 
383 	chandir = debugfs_create_dir("channels", pdev->dbgfs_root);
384 	if (!chandir)
385 		goto err_chandir;
386 
387 	for (i = 0; i < pdev->nr_chans; i++) {
388 		pdev->dbgfs_chan[i] = pxad_dbg_alloc_chan(pdev, i, chandir);
389 		if (!pdev->dbgfs_chan[i])
390 			goto err_chans;
391 	}
392 
393 	return;
394 err_chans:
395 err_chandir:
396 	kfree(pdev->dbgfs_chan);
397 err_alloc:
398 err_state:
399 	debugfs_remove_recursive(pdev->dbgfs_root);
400 err_root:
401 	pr_err("pxad: debugfs is not available\n");
402 }
403 
404 static void pxad_cleanup_debugfs(struct pxad_device *pdev)
405 {
406 	debugfs_remove_recursive(pdev->dbgfs_root);
407 }
408 #else
409 static inline void pxad_init_debugfs(struct pxad_device *pdev) {}
410 static inline void pxad_cleanup_debugfs(struct pxad_device *pdev) {}
411 #endif
412 
413 /*
414  * In the transition phase where legacy pxa handling is done at the same time as
415  * mmp_dma, the DMA physical channel split between the 2 DMA providers is done
416  * through legacy_reserved. Legacy code reserves DMA channels by settings
417  * corresponding bits in legacy_reserved.
418  */
419 static u32 legacy_reserved;
420 static u32 legacy_unavailable;
421 
422 static struct pxad_phy *lookup_phy(struct pxad_chan *pchan)
423 {
424 	int prio, i;
425 	struct pxad_device *pdev = to_pxad_dev(pchan->vc.chan.device);
426 	struct pxad_phy *phy, *found = NULL;
427 	unsigned long flags;
428 
429 	/*
430 	 * dma channel priorities
431 	 * ch 0 - 3,  16 - 19  <--> (0)
432 	 * ch 4 - 7,  20 - 23  <--> (1)
433 	 * ch 8 - 11, 24 - 27  <--> (2)
434 	 * ch 12 - 15, 28 - 31  <--> (3)
435 	 */
436 
437 	spin_lock_irqsave(&pdev->phy_lock, flags);
438 	for (prio = pchan->prio; prio >= PXAD_PRIO_HIGHEST; prio--) {
439 		for (i = 0; i < pdev->nr_chans; i++) {
440 			if (prio != (i & 0xf) >> 2)
441 				continue;
442 			if ((i < 32) && (legacy_reserved & BIT(i)))
443 				continue;
444 			phy = &pdev->phys[i];
445 			if (!phy->vchan) {
446 				phy->vchan = pchan;
447 				found = phy;
448 				if (i < 32)
449 					legacy_unavailable |= BIT(i);
450 				goto out_unlock;
451 			}
452 		}
453 	}
454 
455 out_unlock:
456 	spin_unlock_irqrestore(&pdev->phy_lock, flags);
457 	dev_dbg(&pchan->vc.chan.dev->device,
458 		"%s(): phy=%p(%d)\n", __func__, found,
459 		found ? found->idx : -1);
460 
461 	return found;
462 }
463 
464 static void pxad_free_phy(struct pxad_chan *chan)
465 {
466 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
467 	unsigned long flags;
468 	u32 reg;
469 	int i;
470 
471 	dev_dbg(&chan->vc.chan.dev->device,
472 		"%s(): freeing\n", __func__);
473 	if (!chan->phy)
474 		return;
475 
476 	/* clear the channel mapping in DRCMR */
477 	reg = pxad_drcmr(chan->drcmr);
478 	writel_relaxed(0, chan->phy->base + reg);
479 
480 	spin_lock_irqsave(&pdev->phy_lock, flags);
481 	for (i = 0; i < 32; i++)
482 		if (chan->phy == &pdev->phys[i])
483 			legacy_unavailable &= ~BIT(i);
484 	chan->phy->vchan = NULL;
485 	chan->phy = NULL;
486 	spin_unlock_irqrestore(&pdev->phy_lock, flags);
487 }
488 
489 static bool is_chan_running(struct pxad_chan *chan)
490 {
491 	u32 dcsr;
492 	struct pxad_phy *phy = chan->phy;
493 
494 	if (!phy)
495 		return false;
496 	dcsr = phy_readl_relaxed(phy, DCSR);
497 	return dcsr & PXA_DCSR_RUN;
498 }
499 
500 static bool is_running_chan_misaligned(struct pxad_chan *chan)
501 {
502 	u32 dalgn;
503 
504 	BUG_ON(!chan->phy);
505 	dalgn = phy_readl_relaxed(chan->phy, DALGN);
506 	return dalgn & (BIT(chan->phy->idx));
507 }
508 
509 static void phy_enable(struct pxad_phy *phy, bool misaligned)
510 {
511 	u32 reg, dalgn;
512 
513 	if (!phy->vchan)
514 		return;
515 
516 	dev_dbg(&phy->vchan->vc.chan.dev->device,
517 		"%s(); phy=%p(%d) misaligned=%d\n", __func__,
518 		phy, phy->idx, misaligned);
519 
520 	reg = pxad_drcmr(phy->vchan->drcmr);
521 	writel_relaxed(DRCMR_MAPVLD | phy->idx, phy->base + reg);
522 
523 	dalgn = phy_readl_relaxed(phy, DALGN);
524 	if (misaligned)
525 		dalgn |= BIT(phy->idx);
526 	else
527 		dalgn &= ~BIT(phy->idx);
528 	phy_writel_relaxed(phy, dalgn, DALGN);
529 
530 	phy_writel(phy, PXA_DCSR_STOPIRQEN | PXA_DCSR_ENDINTR |
531 		   PXA_DCSR_BUSERR | PXA_DCSR_RUN, DCSR);
532 }
533 
534 static void phy_disable(struct pxad_phy *phy)
535 {
536 	u32 dcsr;
537 
538 	if (!phy)
539 		return;
540 
541 	dcsr = phy_readl_relaxed(phy, DCSR);
542 	dev_dbg(&phy->vchan->vc.chan.dev->device,
543 		"%s(): phy=%p(%d)\n", __func__, phy, phy->idx);
544 	phy_writel(phy, dcsr & ~PXA_DCSR_RUN & ~PXA_DCSR_STOPIRQEN, DCSR);
545 }
546 
547 static void pxad_launch_chan(struct pxad_chan *chan,
548 				 struct pxad_desc_sw *desc)
549 {
550 	dev_dbg(&chan->vc.chan.dev->device,
551 		"%s(): desc=%p\n", __func__, desc);
552 	if (!chan->phy) {
553 		chan->phy = lookup_phy(chan);
554 		if (!chan->phy) {
555 			dev_dbg(&chan->vc.chan.dev->device,
556 				"%s(): no free dma channel\n", __func__);
557 			return;
558 		}
559 	}
560 
561 	/*
562 	 * Program the descriptor's address into the DMA controller,
563 	 * then start the DMA transaction
564 	 */
565 	phy_writel(chan->phy, desc->first, DDADR);
566 	phy_enable(chan->phy, chan->misaligned);
567 }
568 
569 static void set_updater_desc(struct pxad_desc_sw *sw_desc,
570 			     unsigned long flags)
571 {
572 	struct pxad_desc_hw *updater =
573 		sw_desc->hw_desc[sw_desc->nb_desc - 1];
574 	dma_addr_t dma = sw_desc->hw_desc[sw_desc->nb_desc - 2]->ddadr;
575 
576 	updater->ddadr = DDADR_STOP;
577 	updater->dsadr = dma;
578 	updater->dtadr = dma + 8;
579 	updater->dcmd = PXA_DCMD_WIDTH4 | PXA_DCMD_BURST32 |
580 		(PXA_DCMD_LENGTH & sizeof(u32));
581 	if (flags & DMA_PREP_INTERRUPT)
582 		updater->dcmd |= PXA_DCMD_ENDIRQEN;
583 }
584 
585 static bool is_desc_completed(struct virt_dma_desc *vd)
586 {
587 	struct pxad_desc_sw *sw_desc = to_pxad_sw_desc(vd);
588 	struct pxad_desc_hw *updater =
589 		sw_desc->hw_desc[sw_desc->nb_desc - 1];
590 
591 	return updater->dtadr != (updater->dsadr + 8);
592 }
593 
594 static void pxad_desc_chain(struct virt_dma_desc *vd1,
595 				struct virt_dma_desc *vd2)
596 {
597 	struct pxad_desc_sw *desc1 = to_pxad_sw_desc(vd1);
598 	struct pxad_desc_sw *desc2 = to_pxad_sw_desc(vd2);
599 	dma_addr_t dma_to_chain;
600 
601 	dma_to_chain = desc2->first;
602 	desc1->hw_desc[desc1->nb_desc - 1]->ddadr = dma_to_chain;
603 }
604 
605 static bool pxad_try_hotchain(struct virt_dma_chan *vc,
606 				  struct virt_dma_desc *vd)
607 {
608 	struct virt_dma_desc *vd_last_issued = NULL;
609 	struct pxad_chan *chan = to_pxad_chan(&vc->chan);
610 
611 	/*
612 	 * Attempt to hot chain the tx if the phy is still running. This is
613 	 * considered successful only if either the channel is still running
614 	 * after the chaining, or if the chained transfer is completed after
615 	 * having been hot chained.
616 	 * A change of alignment is not allowed, and forbids hotchaining.
617 	 */
618 	if (is_chan_running(chan)) {
619 		BUG_ON(list_empty(&vc->desc_issued));
620 
621 		if (!is_running_chan_misaligned(chan) &&
622 		    to_pxad_sw_desc(vd)->misaligned)
623 			return false;
624 
625 		vd_last_issued = list_entry(vc->desc_issued.prev,
626 					    struct virt_dma_desc, node);
627 		pxad_desc_chain(vd_last_issued, vd);
628 		if (is_chan_running(chan) || is_desc_completed(vd_last_issued))
629 			return true;
630 	}
631 
632 	return false;
633 }
634 
635 static unsigned int clear_chan_irq(struct pxad_phy *phy)
636 {
637 	u32 dcsr;
638 	u32 dint = readl(phy->base + DINT);
639 
640 	if (!(dint & BIT(phy->idx)))
641 		return PXA_DCSR_RUN;
642 
643 	/* clear irq */
644 	dcsr = phy_readl_relaxed(phy, DCSR);
645 	phy_writel(phy, dcsr, DCSR);
646 	if ((dcsr & PXA_DCSR_BUSERR) && (phy->vchan))
647 		dev_warn(&phy->vchan->vc.chan.dev->device,
648 			 "%s(chan=%p): PXA_DCSR_BUSERR\n",
649 			 __func__, &phy->vchan);
650 
651 	return dcsr & ~PXA_DCSR_RUN;
652 }
653 
654 static irqreturn_t pxad_chan_handler(int irq, void *dev_id)
655 {
656 	struct pxad_phy *phy = dev_id;
657 	struct pxad_chan *chan = phy->vchan;
658 	struct virt_dma_desc *vd, *tmp;
659 	unsigned int dcsr;
660 	unsigned long flags;
661 
662 	BUG_ON(!chan);
663 
664 	dcsr = clear_chan_irq(phy);
665 	if (dcsr & PXA_DCSR_RUN)
666 		return IRQ_NONE;
667 
668 	spin_lock_irqsave(&chan->vc.lock, flags);
669 	list_for_each_entry_safe(vd, tmp, &chan->vc.desc_issued, node) {
670 		dev_dbg(&chan->vc.chan.dev->device,
671 			"%s(): checking txd %p[%x]: completed=%d\n",
672 			__func__, vd, vd->tx.cookie, is_desc_completed(vd));
673 		if (is_desc_completed(vd)) {
674 			list_del(&vd->node);
675 			vchan_cookie_complete(vd);
676 		} else {
677 			break;
678 		}
679 	}
680 
681 	if (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 
700 	return IRQ_HANDLED;
701 }
702 
703 static irqreturn_t pxad_int_handler(int irq, void *dev_id)
704 {
705 	struct pxad_device *pdev = dev_id;
706 	struct pxad_phy *phy;
707 	u32 dint = readl(pdev->base + DINT);
708 	int i, ret = IRQ_NONE;
709 
710 	while (dint) {
711 		i = __ffs(dint);
712 		dint &= (dint - 1);
713 		phy = &pdev->phys[i];
714 		if ((i < 32) && (legacy_reserved & BIT(i)))
715 			continue;
716 		if (pxad_chan_handler(irq, phy) == IRQ_HANDLED)
717 			ret = IRQ_HANDLED;
718 	}
719 
720 	return ret;
721 }
722 
723 static int pxad_alloc_chan_resources(struct dma_chan *dchan)
724 {
725 	struct pxad_chan *chan = to_pxad_chan(dchan);
726 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
727 
728 	if (chan->desc_pool)
729 		return 1;
730 
731 	chan->desc_pool = dma_pool_create(dma_chan_name(dchan),
732 					  pdev->slave.dev,
733 					  sizeof(struct pxad_desc_hw),
734 					  __alignof__(struct pxad_desc_hw),
735 					  0);
736 	if (!chan->desc_pool) {
737 		dev_err(&chan->vc.chan.dev->device,
738 			"%s(): unable to allocate descriptor pool\n",
739 			__func__);
740 		return -ENOMEM;
741 	}
742 
743 	return 1;
744 }
745 
746 static void pxad_free_chan_resources(struct dma_chan *dchan)
747 {
748 	struct pxad_chan *chan = to_pxad_chan(dchan);
749 
750 	vchan_free_chan_resources(&chan->vc);
751 	dma_pool_destroy(chan->desc_pool);
752 	chan->desc_pool = NULL;
753 
754 }
755 
756 static void pxad_free_desc(struct virt_dma_desc *vd)
757 {
758 	int i;
759 	dma_addr_t dma;
760 	struct pxad_desc_sw *sw_desc = to_pxad_sw_desc(vd);
761 
762 	BUG_ON(sw_desc->nb_desc == 0);
763 	for (i = sw_desc->nb_desc - 1; i >= 0; i--) {
764 		if (i > 0)
765 			dma = sw_desc->hw_desc[i - 1]->ddadr;
766 		else
767 			dma = sw_desc->first;
768 		dma_pool_free(sw_desc->desc_pool,
769 			      sw_desc->hw_desc[i], dma);
770 	}
771 	sw_desc->nb_desc = 0;
772 	kfree(sw_desc);
773 }
774 
775 static struct pxad_desc_sw *
776 pxad_alloc_desc(struct pxad_chan *chan, unsigned int nb_hw_desc)
777 {
778 	struct pxad_desc_sw *sw_desc;
779 	dma_addr_t dma;
780 	int i;
781 
782 	sw_desc = kzalloc(sizeof(*sw_desc) +
783 			  nb_hw_desc * sizeof(struct pxad_desc_hw *),
784 			  GFP_NOWAIT);
785 	if (!sw_desc)
786 		return NULL;
787 	sw_desc->desc_pool = chan->desc_pool;
788 
789 	for (i = 0; i < nb_hw_desc; i++) {
790 		sw_desc->hw_desc[i] = dma_pool_alloc(sw_desc->desc_pool,
791 						     GFP_NOWAIT, &dma);
792 		if (!sw_desc->hw_desc[i]) {
793 			dev_err(&chan->vc.chan.dev->device,
794 				"%s(): Couldn't allocate the %dth hw_desc from dma_pool %p\n",
795 				__func__, i, sw_desc->desc_pool);
796 			goto err;
797 		}
798 
799 		if (i == 0)
800 			sw_desc->first = dma;
801 		else
802 			sw_desc->hw_desc[i - 1]->ddadr = dma;
803 		sw_desc->nb_desc++;
804 	}
805 
806 	return sw_desc;
807 err:
808 	pxad_free_desc(&sw_desc->vd);
809 	return NULL;
810 }
811 
812 static dma_cookie_t pxad_tx_submit(struct dma_async_tx_descriptor *tx)
813 {
814 	struct virt_dma_chan *vc = to_virt_chan(tx->chan);
815 	struct pxad_chan *chan = to_pxad_chan(&vc->chan);
816 	struct virt_dma_desc *vd_chained = NULL,
817 		*vd = container_of(tx, struct virt_dma_desc, tx);
818 	dma_cookie_t cookie;
819 	unsigned long flags;
820 
821 	set_updater_desc(to_pxad_sw_desc(vd), tx->flags);
822 
823 	spin_lock_irqsave(&vc->lock, flags);
824 	cookie = dma_cookie_assign(tx);
825 
826 	if (list_empty(&vc->desc_submitted) && pxad_try_hotchain(vc, vd)) {
827 		list_move_tail(&vd->node, &vc->desc_issued);
828 		dev_dbg(&chan->vc.chan.dev->device,
829 			"%s(): txd %p[%x]: submitted (hot linked)\n",
830 			__func__, vd, cookie);
831 		goto out;
832 	}
833 
834 	/*
835 	 * Fallback to placing the tx in the submitted queue
836 	 */
837 	if (!list_empty(&vc->desc_submitted)) {
838 		vd_chained = list_entry(vc->desc_submitted.prev,
839 					struct virt_dma_desc, node);
840 		/*
841 		 * Only chain the descriptors if no new misalignment is
842 		 * introduced. If a new misalignment is chained, let the channel
843 		 * stop, and be relaunched in misalign mode from the irq
844 		 * handler.
845 		 */
846 		if (chan->misaligned || !to_pxad_sw_desc(vd)->misaligned)
847 			pxad_desc_chain(vd_chained, vd);
848 		else
849 			vd_chained = NULL;
850 	}
851 	dev_dbg(&chan->vc.chan.dev->device,
852 		"%s(): txd %p[%x]: submitted (%s linked)\n",
853 		__func__, vd, cookie, vd_chained ? "cold" : "not");
854 	list_move_tail(&vd->node, &vc->desc_submitted);
855 	chan->misaligned |= to_pxad_sw_desc(vd)->misaligned;
856 
857 out:
858 	spin_unlock_irqrestore(&vc->lock, flags);
859 	return cookie;
860 }
861 
862 static void pxad_issue_pending(struct dma_chan *dchan)
863 {
864 	struct pxad_chan *chan = to_pxad_chan(dchan);
865 	struct virt_dma_desc *vd_first;
866 	unsigned long flags;
867 
868 	spin_lock_irqsave(&chan->vc.lock, flags);
869 	if (list_empty(&chan->vc.desc_submitted))
870 		goto out;
871 
872 	vd_first = list_first_entry(&chan->vc.desc_submitted,
873 				    struct virt_dma_desc, node);
874 	dev_dbg(&chan->vc.chan.dev->device,
875 		"%s(): txd %p[%x]", __func__, vd_first, vd_first->tx.cookie);
876 
877 	vchan_issue_pending(&chan->vc);
878 	if (!pxad_try_hotchain(&chan->vc, vd_first))
879 		pxad_launch_chan(chan, to_pxad_sw_desc(vd_first));
880 out:
881 	spin_unlock_irqrestore(&chan->vc.lock, flags);
882 }
883 
884 static inline struct dma_async_tx_descriptor *
885 pxad_tx_prep(struct virt_dma_chan *vc, struct virt_dma_desc *vd,
886 		 unsigned long tx_flags)
887 {
888 	struct dma_async_tx_descriptor *tx;
889 	struct pxad_chan *chan = container_of(vc, struct pxad_chan, vc);
890 
891 	tx = vchan_tx_prep(vc, vd, tx_flags);
892 	tx->tx_submit = pxad_tx_submit;
893 	dev_dbg(&chan->vc.chan.dev->device,
894 		"%s(): vc=%p txd=%p[%x] flags=0x%lx\n", __func__,
895 		vc, vd, vd->tx.cookie,
896 		tx_flags);
897 
898 	return tx;
899 }
900 
901 static void pxad_get_config(struct pxad_chan *chan,
902 			    enum dma_transfer_direction dir,
903 			    u32 *dcmd, u32 *dev_src, u32 *dev_dst)
904 {
905 	u32 maxburst = 0, dev_addr = 0;
906 	enum dma_slave_buswidth width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
907 
908 	*dcmd = 0;
909 	if (chan->cfg.direction == 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 | PXA_DCMD_FLOWSRC;
915 	}
916 	if (chan->cfg.direction == DMA_MEM_TO_DEV) {
917 		maxburst = chan->cfg.dst_maxburst;
918 		width = chan->cfg.dst_addr_width;
919 		dev_addr = chan->cfg.dst_addr;
920 		*dev_dst = dev_addr;
921 		*dcmd |= PXA_DCMD_INCSRCADDR | PXA_DCMD_FLOWTRG;
922 	}
923 	if (chan->cfg.direction == DMA_MEM_TO_MEM)
924 		*dcmd |= PXA_DCMD_BURST32 | PXA_DCMD_INCTRGADDR |
925 			PXA_DCMD_INCSRCADDR;
926 
927 	dev_dbg(&chan->vc.chan.dev->device,
928 		"%s(): dev_addr=0x%x maxburst=%d width=%d  dir=%d\n",
929 		__func__, dev_addr, maxburst, width, dir);
930 
931 	if (width == DMA_SLAVE_BUSWIDTH_1_BYTE)
932 		*dcmd |= PXA_DCMD_WIDTH1;
933 	else if (width == DMA_SLAVE_BUSWIDTH_2_BYTES)
934 		*dcmd |= PXA_DCMD_WIDTH2;
935 	else if (width == DMA_SLAVE_BUSWIDTH_4_BYTES)
936 		*dcmd |= PXA_DCMD_WIDTH4;
937 
938 	if (maxburst == 8)
939 		*dcmd |= PXA_DCMD_BURST8;
940 	else if (maxburst == 16)
941 		*dcmd |= PXA_DCMD_BURST16;
942 	else if (maxburst == 32)
943 		*dcmd |= PXA_DCMD_BURST32;
944 
945 	/* FIXME: drivers should be ported over to use the filter
946 	 * function. Once that's done, the following two lines can
947 	 * be removed.
948 	 */
949 	if (chan->cfg.slave_id)
950 		chan->drcmr = chan->cfg.slave_id;
951 }
952 
953 static struct dma_async_tx_descriptor *
954 pxad_prep_memcpy(struct dma_chan *dchan,
955 		 dma_addr_t dma_dst, dma_addr_t dma_src,
956 		 size_t len, unsigned long flags)
957 {
958 	struct pxad_chan *chan = to_pxad_chan(dchan);
959 	struct pxad_desc_sw *sw_desc;
960 	struct pxad_desc_hw *hw_desc;
961 	u32 dcmd;
962 	unsigned int i, nb_desc = 0;
963 	size_t copy;
964 
965 	if (!dchan || !len)
966 		return NULL;
967 
968 	dev_dbg(&chan->vc.chan.dev->device,
969 		"%s(): dma_dst=0x%lx dma_src=0x%lx len=%zu flags=%lx\n",
970 		__func__, (unsigned long)dma_dst, (unsigned long)dma_src,
971 		len, flags);
972 	pxad_get_config(chan, DMA_MEM_TO_MEM, &dcmd, NULL, NULL);
973 
974 	nb_desc = DIV_ROUND_UP(len, PDMA_MAX_DESC_BYTES);
975 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
976 	if (!sw_desc)
977 		return NULL;
978 	sw_desc->len = len;
979 
980 	if (!IS_ALIGNED(dma_src, 1 << PDMA_ALIGNMENT) ||
981 	    !IS_ALIGNED(dma_dst, 1 << PDMA_ALIGNMENT))
982 		sw_desc->misaligned = true;
983 
984 	i = 0;
985 	do {
986 		hw_desc = sw_desc->hw_desc[i++];
987 		copy = min_t(size_t, len, PDMA_MAX_DESC_BYTES);
988 		hw_desc->dcmd = dcmd | (PXA_DCMD_LENGTH & copy);
989 		hw_desc->dsadr = dma_src;
990 		hw_desc->dtadr = dma_dst;
991 		len -= copy;
992 		dma_src += copy;
993 		dma_dst += copy;
994 	} while (len);
995 	set_updater_desc(sw_desc, flags);
996 
997 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
998 }
999 
1000 static struct dma_async_tx_descriptor *
1001 pxad_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
1002 		   unsigned int sg_len, enum dma_transfer_direction dir,
1003 		   unsigned long flags, void *context)
1004 {
1005 	struct pxad_chan *chan = to_pxad_chan(dchan);
1006 	struct pxad_desc_sw *sw_desc;
1007 	size_t len, avail;
1008 	struct scatterlist *sg;
1009 	dma_addr_t dma;
1010 	u32 dcmd, dsadr = 0, dtadr = 0;
1011 	unsigned int nb_desc = 0, i, j = 0;
1012 
1013 	if ((sgl == NULL) || (sg_len == 0))
1014 		return NULL;
1015 
1016 	pxad_get_config(chan, dir, &dcmd, &dsadr, &dtadr);
1017 	dev_dbg(&chan->vc.chan.dev->device,
1018 		"%s(): dir=%d flags=%lx\n", __func__, dir, flags);
1019 
1020 	for_each_sg(sgl, sg, sg_len, i)
1021 		nb_desc += DIV_ROUND_UP(sg_dma_len(sg), PDMA_MAX_DESC_BYTES);
1022 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
1023 	if (!sw_desc)
1024 		return NULL;
1025 
1026 	for_each_sg(sgl, sg, sg_len, i) {
1027 		dma = sg_dma_address(sg);
1028 		avail = sg_dma_len(sg);
1029 		sw_desc->len += avail;
1030 
1031 		do {
1032 			len = min_t(size_t, avail, PDMA_MAX_DESC_BYTES);
1033 			if (dma & 0x7)
1034 				sw_desc->misaligned = true;
1035 
1036 			sw_desc->hw_desc[j]->dcmd =
1037 				dcmd | (PXA_DCMD_LENGTH & len);
1038 			sw_desc->hw_desc[j]->dsadr = dsadr ? dsadr : dma;
1039 			sw_desc->hw_desc[j++]->dtadr = dtadr ? dtadr : dma;
1040 
1041 			dma += len;
1042 			avail -= len;
1043 		} while (avail);
1044 	}
1045 	set_updater_desc(sw_desc, flags);
1046 
1047 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
1048 }
1049 
1050 static struct dma_async_tx_descriptor *
1051 pxad_prep_dma_cyclic(struct dma_chan *dchan,
1052 		     dma_addr_t buf_addr, size_t len, size_t period_len,
1053 		     enum dma_transfer_direction dir, unsigned long flags)
1054 {
1055 	struct pxad_chan *chan = to_pxad_chan(dchan);
1056 	struct pxad_desc_sw *sw_desc;
1057 	struct pxad_desc_hw **phw_desc;
1058 	dma_addr_t dma;
1059 	u32 dcmd, dsadr = 0, dtadr = 0;
1060 	unsigned int nb_desc = 0;
1061 
1062 	if (!dchan || !len || !period_len)
1063 		return NULL;
1064 	if ((dir != DMA_DEV_TO_MEM) && (dir != DMA_MEM_TO_DEV)) {
1065 		dev_err(&chan->vc.chan.dev->device,
1066 			"Unsupported direction for cyclic DMA\n");
1067 		return NULL;
1068 	}
1069 	/* the buffer length must be a multiple of period_len */
1070 	if (len % period_len != 0 || period_len > PDMA_MAX_DESC_BYTES ||
1071 	    !IS_ALIGNED(period_len, 1 << PDMA_ALIGNMENT))
1072 		return NULL;
1073 
1074 	pxad_get_config(chan, dir, &dcmd, &dsadr, &dtadr);
1075 	dcmd |= PXA_DCMD_ENDIRQEN | (PXA_DCMD_LENGTH | period_len);
1076 	dev_dbg(&chan->vc.chan.dev->device,
1077 		"%s(): buf_addr=0x%lx len=%zu period=%zu dir=%d flags=%lx\n",
1078 		__func__, (unsigned long)buf_addr, len, period_len, dir, flags);
1079 
1080 	nb_desc = DIV_ROUND_UP(period_len, PDMA_MAX_DESC_BYTES);
1081 	nb_desc *= DIV_ROUND_UP(len, period_len);
1082 	sw_desc = pxad_alloc_desc(chan, nb_desc + 1);
1083 	if (!sw_desc)
1084 		return NULL;
1085 	sw_desc->cyclic = true;
1086 	sw_desc->len = len;
1087 
1088 	phw_desc = sw_desc->hw_desc;
1089 	dma = buf_addr;
1090 	do {
1091 		phw_desc[0]->dsadr = dsadr ? dsadr : dma;
1092 		phw_desc[0]->dtadr = dtadr ? dtadr : dma;
1093 		phw_desc[0]->dcmd = dcmd;
1094 		phw_desc++;
1095 		dma += period_len;
1096 		len -= period_len;
1097 	} while (len);
1098 	set_updater_desc(sw_desc, flags);
1099 
1100 	return pxad_tx_prep(&chan->vc, &sw_desc->vd, flags);
1101 }
1102 
1103 static int pxad_config(struct dma_chan *dchan,
1104 		       struct dma_slave_config *cfg)
1105 {
1106 	struct pxad_chan *chan = to_pxad_chan(dchan);
1107 
1108 	if (!dchan)
1109 		return -EINVAL;
1110 
1111 	chan->cfg = *cfg;
1112 	return 0;
1113 }
1114 
1115 static int pxad_terminate_all(struct dma_chan *dchan)
1116 {
1117 	struct pxad_chan *chan = to_pxad_chan(dchan);
1118 	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
1119 	struct virt_dma_desc *vd = NULL;
1120 	unsigned long flags;
1121 	struct pxad_phy *phy;
1122 	LIST_HEAD(head);
1123 
1124 	dev_dbg(&chan->vc.chan.dev->device,
1125 		"%s(): vchan %p: terminate all\n", __func__, &chan->vc);
1126 
1127 	spin_lock_irqsave(&chan->vc.lock, flags);
1128 	vchan_get_all_descriptors(&chan->vc, &head);
1129 
1130 	list_for_each_entry(vd, &head, node) {
1131 		dev_dbg(&chan->vc.chan.dev->device,
1132 			"%s(): cancelling txd %p[%x] (completed=%d)", __func__,
1133 			vd, vd->tx.cookie, is_desc_completed(vd));
1134 	}
1135 
1136 	phy = chan->phy;
1137 	if (phy) {
1138 		phy_disable(chan->phy);
1139 		pxad_free_phy(chan);
1140 		chan->phy = NULL;
1141 		spin_lock(&pdev->phy_lock);
1142 		phy->vchan = NULL;
1143 		spin_unlock(&pdev->phy_lock);
1144 	}
1145 	spin_unlock_irqrestore(&chan->vc.lock, flags);
1146 	vchan_dma_desc_free_list(&chan->vc, &head);
1147 
1148 	return 0;
1149 }
1150 
1151 static unsigned int pxad_residue(struct pxad_chan *chan,
1152 				 dma_cookie_t cookie)
1153 {
1154 	struct virt_dma_desc *vd = NULL;
1155 	struct pxad_desc_sw *sw_desc = NULL;
1156 	struct pxad_desc_hw *hw_desc = NULL;
1157 	u32 curr, start, len, end, residue = 0;
1158 	unsigned long flags;
1159 	bool passed = false;
1160 	int i;
1161 
1162 	/*
1163 	 * If the channel does not have a phy pointer anymore, it has already
1164 	 * been completed. Therefore, its residue is 0.
1165 	 */
1166 	if (!chan->phy)
1167 		return 0;
1168 
1169 	spin_lock_irqsave(&chan->vc.lock, flags);
1170 
1171 	vd = vchan_find_desc(&chan->vc, cookie);
1172 	if (!vd)
1173 		goto out;
1174 
1175 	sw_desc = to_pxad_sw_desc(vd);
1176 	if (sw_desc->hw_desc[0]->dcmd & PXA_DCMD_INCSRCADDR)
1177 		curr = phy_readl_relaxed(chan->phy, DSADR);
1178 	else
1179 		curr = phy_readl_relaxed(chan->phy, DTADR);
1180 
1181 	for (i = 0; i < sw_desc->nb_desc - 1; i++) {
1182 		hw_desc = sw_desc->hw_desc[i];
1183 		if (sw_desc->hw_desc[0]->dcmd & PXA_DCMD_INCSRCADDR)
1184 			start = hw_desc->dsadr;
1185 		else
1186 			start = hw_desc->dtadr;
1187 		len = hw_desc->dcmd & PXA_DCMD_LENGTH;
1188 		end = start + len;
1189 
1190 		/*
1191 		 * 'passed' will be latched once we found the descriptor
1192 		 * which lies inside the boundaries of the curr
1193 		 * pointer. All descriptors that occur in the list
1194 		 * _after_ we found that partially handled descriptor
1195 		 * are still to be processed and are hence added to the
1196 		 * residual bytes counter.
1197 		 */
1198 
1199 		if (passed) {
1200 			residue += len;
1201 		} else if (curr >= start && curr <= end) {
1202 			residue += end - curr;
1203 			passed = true;
1204 		}
1205 	}
1206 	if (!passed)
1207 		residue = sw_desc->len;
1208 
1209 out:
1210 	spin_unlock_irqrestore(&chan->vc.lock, flags);
1211 	dev_dbg(&chan->vc.chan.dev->device,
1212 		"%s(): txd %p[%x] sw_desc=%p: %d\n",
1213 		__func__, vd, cookie, sw_desc, residue);
1214 	return residue;
1215 }
1216 
1217 static enum dma_status pxad_tx_status(struct dma_chan *dchan,
1218 				      dma_cookie_t cookie,
1219 				      struct dma_tx_state *txstate)
1220 {
1221 	struct pxad_chan *chan = to_pxad_chan(dchan);
1222 	enum dma_status ret;
1223 
1224 	ret = dma_cookie_status(dchan, cookie, txstate);
1225 	if (likely(txstate && (ret != DMA_ERROR)))
1226 		dma_set_residue(txstate, pxad_residue(chan, cookie));
1227 
1228 	return ret;
1229 }
1230 
1231 static void pxad_free_channels(struct dma_device *dmadev)
1232 {
1233 	struct pxad_chan *c, *cn;
1234 
1235 	list_for_each_entry_safe(c, cn, &dmadev->channels,
1236 				 vc.chan.device_node) {
1237 		list_del(&c->vc.chan.device_node);
1238 		tasklet_kill(&c->vc.task);
1239 	}
1240 }
1241 
1242 static int pxad_remove(struct platform_device *op)
1243 {
1244 	struct pxad_device *pdev = platform_get_drvdata(op);
1245 
1246 	pxad_cleanup_debugfs(pdev);
1247 	pxad_free_channels(&pdev->slave);
1248 	dma_async_device_unregister(&pdev->slave);
1249 	return 0;
1250 }
1251 
1252 static int pxad_init_phys(struct platform_device *op,
1253 			  struct pxad_device *pdev,
1254 			  unsigned int nb_phy_chans)
1255 {
1256 	int irq0, irq, nr_irq = 0, i, ret;
1257 	struct pxad_phy *phy;
1258 
1259 	irq0 = platform_get_irq(op, 0);
1260 	if (irq0 < 0)
1261 		return irq0;
1262 
1263 	pdev->phys = devm_kcalloc(&op->dev, nb_phy_chans,
1264 				  sizeof(pdev->phys[0]), GFP_KERNEL);
1265 	if (!pdev->phys)
1266 		return -ENOMEM;
1267 
1268 	for (i = 0; i < nb_phy_chans; i++)
1269 		if (platform_get_irq(op, i) > 0)
1270 			nr_irq++;
1271 
1272 	for (i = 0; i < nb_phy_chans; i++) {
1273 		phy = &pdev->phys[i];
1274 		phy->base = pdev->base;
1275 		phy->idx = i;
1276 		irq = platform_get_irq(op, i);
1277 		if ((nr_irq > 1) && (irq > 0))
1278 			ret = devm_request_irq(&op->dev, irq,
1279 					       pxad_chan_handler,
1280 					       IRQF_SHARED, "pxa-dma", phy);
1281 		if ((nr_irq == 1) && (i == 0))
1282 			ret = devm_request_irq(&op->dev, irq0,
1283 					       pxad_int_handler,
1284 					       IRQF_SHARED, "pxa-dma", pdev);
1285 		if (ret) {
1286 			dev_err(pdev->slave.dev,
1287 				"%s(): can't request irq %d:%d\n", __func__,
1288 				irq, ret);
1289 			return ret;
1290 		}
1291 	}
1292 
1293 	return 0;
1294 }
1295 
1296 static const struct of_device_id const pxad_dt_ids[] = {
1297 	{ .compatible = "marvell,pdma-1.0", },
1298 	{}
1299 };
1300 MODULE_DEVICE_TABLE(of, pxad_dt_ids);
1301 
1302 static struct dma_chan *pxad_dma_xlate(struct of_phandle_args *dma_spec,
1303 					   struct of_dma *ofdma)
1304 {
1305 	struct pxad_device *d = ofdma->of_dma_data;
1306 	struct dma_chan *chan;
1307 
1308 	chan = dma_get_any_slave_channel(&d->slave);
1309 	if (!chan)
1310 		return NULL;
1311 
1312 	to_pxad_chan(chan)->drcmr = dma_spec->args[0];
1313 	to_pxad_chan(chan)->prio = dma_spec->args[1];
1314 
1315 	return chan;
1316 }
1317 
1318 static int pxad_init_dmadev(struct platform_device *op,
1319 			    struct pxad_device *pdev,
1320 			    unsigned int nr_phy_chans)
1321 {
1322 	int ret;
1323 	unsigned int i;
1324 	struct pxad_chan *c;
1325 
1326 	pdev->nr_chans = nr_phy_chans;
1327 	INIT_LIST_HEAD(&pdev->slave.channels);
1328 	pdev->slave.device_alloc_chan_resources = pxad_alloc_chan_resources;
1329 	pdev->slave.device_free_chan_resources = pxad_free_chan_resources;
1330 	pdev->slave.device_tx_status = pxad_tx_status;
1331 	pdev->slave.device_issue_pending = pxad_issue_pending;
1332 	pdev->slave.device_config = pxad_config;
1333 	pdev->slave.device_terminate_all = pxad_terminate_all;
1334 
1335 	if (op->dev.coherent_dma_mask)
1336 		dma_set_mask(&op->dev, op->dev.coherent_dma_mask);
1337 	else
1338 		dma_set_mask(&op->dev, DMA_BIT_MASK(32));
1339 
1340 	ret = pxad_init_phys(op, pdev, nr_phy_chans);
1341 	if (ret)
1342 		return ret;
1343 
1344 	for (i = 0; i < nr_phy_chans; i++) {
1345 		c = devm_kzalloc(&op->dev, sizeof(*c), GFP_KERNEL);
1346 		if (!c)
1347 			return -ENOMEM;
1348 		c->vc.desc_free = pxad_free_desc;
1349 		vchan_init(&c->vc, &pdev->slave);
1350 	}
1351 
1352 	return dma_async_device_register(&pdev->slave);
1353 }
1354 
1355 static int pxad_probe(struct platform_device *op)
1356 {
1357 	struct pxad_device *pdev;
1358 	const struct of_device_id *of_id;
1359 	struct mmp_dma_platdata *pdata = dev_get_platdata(&op->dev);
1360 	struct resource *iores;
1361 	int ret, dma_channels = 0;
1362 	const enum dma_slave_buswidth widths =
1363 		DMA_SLAVE_BUSWIDTH_1_BYTE   | DMA_SLAVE_BUSWIDTH_2_BYTES |
1364 		DMA_SLAVE_BUSWIDTH_4_BYTES;
1365 
1366 	pdev = devm_kzalloc(&op->dev, sizeof(*pdev), GFP_KERNEL);
1367 	if (!pdev)
1368 		return -ENOMEM;
1369 
1370 	spin_lock_init(&pdev->phy_lock);
1371 
1372 	iores = platform_get_resource(op, IORESOURCE_MEM, 0);
1373 	pdev->base = devm_ioremap_resource(&op->dev, iores);
1374 	if (IS_ERR(pdev->base))
1375 		return PTR_ERR(pdev->base);
1376 
1377 	of_id = of_match_device(pxad_dt_ids, &op->dev);
1378 	if (of_id)
1379 		of_property_read_u32(op->dev.of_node, "#dma-channels",
1380 				     &dma_channels);
1381 	else if (pdata && pdata->dma_channels)
1382 		dma_channels = pdata->dma_channels;
1383 	else
1384 		dma_channels = 32;	/* default 32 channel */
1385 
1386 	dma_cap_set(DMA_SLAVE, pdev->slave.cap_mask);
1387 	dma_cap_set(DMA_MEMCPY, pdev->slave.cap_mask);
1388 	dma_cap_set(DMA_CYCLIC, pdev->slave.cap_mask);
1389 	dma_cap_set(DMA_PRIVATE, pdev->slave.cap_mask);
1390 	pdev->slave.device_prep_dma_memcpy = pxad_prep_memcpy;
1391 	pdev->slave.device_prep_slave_sg = pxad_prep_slave_sg;
1392 	pdev->slave.device_prep_dma_cyclic = pxad_prep_dma_cyclic;
1393 
1394 	pdev->slave.copy_align = PDMA_ALIGNMENT;
1395 	pdev->slave.src_addr_widths = widths;
1396 	pdev->slave.dst_addr_widths = widths;
1397 	pdev->slave.directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
1398 	pdev->slave.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
1399 
1400 	pdev->slave.dev = &op->dev;
1401 	ret = pxad_init_dmadev(op, pdev, dma_channels);
1402 	if (ret) {
1403 		dev_err(pdev->slave.dev, "unable to register\n");
1404 		return ret;
1405 	}
1406 
1407 	if (op->dev.of_node) {
1408 		/* Device-tree DMA controller registration */
1409 		ret = of_dma_controller_register(op->dev.of_node,
1410 						 pxad_dma_xlate, pdev);
1411 		if (ret < 0) {
1412 			dev_err(pdev->slave.dev,
1413 				"of_dma_controller_register failed\n");
1414 			return ret;
1415 		}
1416 	}
1417 
1418 	platform_set_drvdata(op, pdev);
1419 	pxad_init_debugfs(pdev);
1420 	dev_info(pdev->slave.dev, "initialized %d channels\n", dma_channels);
1421 	return 0;
1422 }
1423 
1424 static const struct platform_device_id pxad_id_table[] = {
1425 	{ "pxa-dma", },
1426 	{ },
1427 };
1428 
1429 static struct platform_driver pxad_driver = {
1430 	.driver		= {
1431 		.name	= "pxa-dma",
1432 		.of_match_table = pxad_dt_ids,
1433 	},
1434 	.id_table	= pxad_id_table,
1435 	.probe		= pxad_probe,
1436 	.remove		= pxad_remove,
1437 };
1438 
1439 bool pxad_filter_fn(struct dma_chan *chan, void *param)
1440 {
1441 	struct pxad_chan *c = to_pxad_chan(chan);
1442 	struct pxad_param *p = param;
1443 
1444 	if (chan->device->dev->driver != &pxad_driver.driver)
1445 		return false;
1446 
1447 	c->drcmr = p->drcmr;
1448 	c->prio = p->prio;
1449 
1450 	return true;
1451 }
1452 EXPORT_SYMBOL_GPL(pxad_filter_fn);
1453 
1454 int pxad_toggle_reserved_channel(int legacy_channel)
1455 {
1456 	if (legacy_unavailable & (BIT(legacy_channel)))
1457 		return -EBUSY;
1458 	legacy_reserved ^= BIT(legacy_channel);
1459 	return 0;
1460 }
1461 EXPORT_SYMBOL_GPL(pxad_toggle_reserved_channel);
1462 
1463 module_platform_driver(pxad_driver);
1464 
1465 MODULE_DESCRIPTION("Marvell PXA Peripheral DMA Driver");
1466 MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");
1467 MODULE_LICENSE("GPL v2");
1468