xref: /linux/drivers/dma/amba-pl08x.c (revision e0bf6c5ca2d3281f231c5f0c9bf145e9513644de)
1 /*
2  * Copyright (c) 2006 ARM Ltd.
3  * Copyright (c) 2010 ST-Ericsson SA
4  *
5  * Author: Peter Pearse <peter.pearse@arm.com>
6  * Author: Linus Walleij <linus.walleij@stericsson.com>
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of the GNU General Public License as published by the Free
10  * Software Foundation; either version 2 of the License, or (at your option)
11  * any later version.
12  *
13  * This program is distributed in the hope that it will be useful, but WITHOUT
14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
16  * more details.
17  *
18  * You should have received a copy of the GNU General Public License along with
19  * this program; if not, write to the Free Software Foundation, Inc., 59
20  * Temple Place - Suite 330, Boston, MA  02111-1307, USA.
21  *
22  * The full GNU General Public License is in this distribution in the file
23  * called COPYING.
24  *
25  * Documentation: ARM DDI 0196G == PL080
26  * Documentation: ARM DDI 0218E == PL081
27  * Documentation: S3C6410 User's Manual == PL080S
28  *
29  * PL080 & PL081 both have 16 sets of DMA signals that can be routed to any
30  * channel.
31  *
32  * The PL080 has 8 channels available for simultaneous use, and the PL081
33  * has only two channels. So on these DMA controllers the number of channels
34  * and the number of incoming DMA signals are two totally different things.
35  * It is usually not possible to theoretically handle all physical signals,
36  * so a multiplexing scheme with possible denial of use is necessary.
37  *
38  * The PL080 has a dual bus master, PL081 has a single master.
39  *
40  * PL080S is a version modified by Samsung and used in S3C64xx SoCs.
41  * It differs in following aspects:
42  * - CH_CONFIG register at different offset,
43  * - separate CH_CONTROL2 register for transfer size,
44  * - bigger maximum transfer size,
45  * - 8-word aligned LLI, instead of 4-word, due to extra CCTL2 word,
46  * - no support for peripheral flow control.
47  *
48  * Memory to peripheral transfer may be visualized as
49  *	Get data from memory to DMAC
50  *	Until no data left
51  *		On burst request from peripheral
52  *			Destination burst from DMAC to peripheral
53  *			Clear burst request
54  *	Raise terminal count interrupt
55  *
56  * For peripherals with a FIFO:
57  * Source      burst size == half the depth of the peripheral FIFO
58  * Destination burst size == the depth of the peripheral FIFO
59  *
60  * (Bursts are irrelevant for mem to mem transfers - there are no burst
61  * signals, the DMA controller will simply facilitate its AHB master.)
62  *
63  * ASSUMES default (little) endianness for DMA transfers
64  *
65  * The PL08x has two flow control settings:
66  *  - DMAC flow control: the transfer size defines the number of transfers
67  *    which occur for the current LLI entry, and the DMAC raises TC at the
68  *    end of every LLI entry.  Observed behaviour shows the DMAC listening
69  *    to both the BREQ and SREQ signals (contrary to documented),
70  *    transferring data if either is active.  The LBREQ and LSREQ signals
71  *    are ignored.
72  *
73  *  - Peripheral flow control: the transfer size is ignored (and should be
74  *    zero).  The data is transferred from the current LLI entry, until
75  *    after the final transfer signalled by LBREQ or LSREQ.  The DMAC
76  *    will then move to the next LLI entry. Unsupported by PL080S.
77  */
78 #include <linux/amba/bus.h>
79 #include <linux/amba/pl08x.h>
80 #include <linux/debugfs.h>
81 #include <linux/delay.h>
82 #include <linux/device.h>
83 #include <linux/dmaengine.h>
84 #include <linux/dmapool.h>
85 #include <linux/dma-mapping.h>
86 #include <linux/export.h>
87 #include <linux/init.h>
88 #include <linux/interrupt.h>
89 #include <linux/module.h>
90 #include <linux/pm_runtime.h>
91 #include <linux/seq_file.h>
92 #include <linux/slab.h>
93 #include <linux/amba/pl080.h>
94 
95 #include "dmaengine.h"
96 #include "virt-dma.h"
97 
98 #define DRIVER_NAME	"pl08xdmac"
99 
100 #define PL80X_DMA_BUSWIDTHS \
101 	BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) | \
102 	BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
103 	BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
104 	BIT(DMA_SLAVE_BUSWIDTH_4_BYTES)
105 
106 static struct amba_driver pl08x_amba_driver;
107 struct pl08x_driver_data;
108 
109 /**
110  * struct vendor_data - vendor-specific config parameters for PL08x derivatives
111  * @channels: the number of channels available in this variant
112  * @dualmaster: whether this version supports dual AHB masters or not.
113  * @nomadik: whether the channels have Nomadik security extension bits
114  *	that need to be checked for permission before use and some registers are
115  *	missing
116  * @pl080s: whether this version is a PL080S, which has separate register and
117  *	LLI word for transfer size.
118  */
119 struct vendor_data {
120 	u8 config_offset;
121 	u8 channels;
122 	bool dualmaster;
123 	bool nomadik;
124 	bool pl080s;
125 	u32 max_transfer_size;
126 };
127 
128 /**
129  * struct pl08x_bus_data - information of source or destination
130  * busses for a transfer
131  * @addr: current address
132  * @maxwidth: the maximum width of a transfer on this bus
133  * @buswidth: the width of this bus in bytes: 1, 2 or 4
134  */
135 struct pl08x_bus_data {
136 	dma_addr_t addr;
137 	u8 maxwidth;
138 	u8 buswidth;
139 };
140 
141 #define IS_BUS_ALIGNED(bus) IS_ALIGNED((bus)->addr, (bus)->buswidth)
142 
143 /**
144  * struct pl08x_phy_chan - holder for the physical channels
145  * @id: physical index to this channel
146  * @lock: a lock to use when altering an instance of this struct
147  * @serving: the virtual channel currently being served by this physical
148  * channel
149  * @locked: channel unavailable for the system, e.g. dedicated to secure
150  * world
151  */
152 struct pl08x_phy_chan {
153 	unsigned int id;
154 	void __iomem *base;
155 	void __iomem *reg_config;
156 	spinlock_t lock;
157 	struct pl08x_dma_chan *serving;
158 	bool locked;
159 };
160 
161 /**
162  * struct pl08x_sg - structure containing data per sg
163  * @src_addr: src address of sg
164  * @dst_addr: dst address of sg
165  * @len: transfer len in bytes
166  * @node: node for txd's dsg_list
167  */
168 struct pl08x_sg {
169 	dma_addr_t src_addr;
170 	dma_addr_t dst_addr;
171 	size_t len;
172 	struct list_head node;
173 };
174 
175 /**
176  * struct pl08x_txd - wrapper for struct dma_async_tx_descriptor
177  * @vd: virtual DMA descriptor
178  * @dsg_list: list of children sg's
179  * @llis_bus: DMA memory address (physical) start for the LLIs
180  * @llis_va: virtual memory address start for the LLIs
181  * @cctl: control reg values for current txd
182  * @ccfg: config reg values for current txd
183  * @done: this marks completed descriptors, which should not have their
184  *   mux released.
185  * @cyclic: indicate cyclic transfers
186  */
187 struct pl08x_txd {
188 	struct virt_dma_desc vd;
189 	struct list_head dsg_list;
190 	dma_addr_t llis_bus;
191 	u32 *llis_va;
192 	/* Default cctl value for LLIs */
193 	u32 cctl;
194 	/*
195 	 * Settings to be put into the physical channel when we
196 	 * trigger this txd.  Other registers are in llis_va[0].
197 	 */
198 	u32 ccfg;
199 	bool done;
200 	bool cyclic;
201 };
202 
203 /**
204  * struct pl08x_dma_chan_state - holds the PL08x specific virtual channel
205  * states
206  * @PL08X_CHAN_IDLE: the channel is idle
207  * @PL08X_CHAN_RUNNING: the channel has allocated a physical transport
208  * channel and is running a transfer on it
209  * @PL08X_CHAN_PAUSED: the channel has allocated a physical transport
210  * channel, but the transfer is currently paused
211  * @PL08X_CHAN_WAITING: the channel is waiting for a physical transport
212  * channel to become available (only pertains to memcpy channels)
213  */
214 enum pl08x_dma_chan_state {
215 	PL08X_CHAN_IDLE,
216 	PL08X_CHAN_RUNNING,
217 	PL08X_CHAN_PAUSED,
218 	PL08X_CHAN_WAITING,
219 };
220 
221 /**
222  * struct pl08x_dma_chan - this structure wraps a DMA ENGINE channel
223  * @vc: wrappped virtual channel
224  * @phychan: the physical channel utilized by this channel, if there is one
225  * @name: name of channel
226  * @cd: channel platform data
227  * @runtime_addr: address for RX/TX according to the runtime config
228  * @at: active transaction on this channel
229  * @lock: a lock for this channel data
230  * @host: a pointer to the host (internal use)
231  * @state: whether the channel is idle, paused, running etc
232  * @slave: whether this channel is a device (slave) or for memcpy
233  * @signal: the physical DMA request signal which this channel is using
234  * @mux_use: count of descriptors using this DMA request signal setting
235  */
236 struct pl08x_dma_chan {
237 	struct virt_dma_chan vc;
238 	struct pl08x_phy_chan *phychan;
239 	const char *name;
240 	const struct pl08x_channel_data *cd;
241 	struct dma_slave_config cfg;
242 	struct pl08x_txd *at;
243 	struct pl08x_driver_data *host;
244 	enum pl08x_dma_chan_state state;
245 	bool slave;
246 	int signal;
247 	unsigned mux_use;
248 };
249 
250 /**
251  * struct pl08x_driver_data - the local state holder for the PL08x
252  * @slave: slave engine for this instance
253  * @memcpy: memcpy engine for this instance
254  * @base: virtual memory base (remapped) for the PL08x
255  * @adev: the corresponding AMBA (PrimeCell) bus entry
256  * @vd: vendor data for this PL08x variant
257  * @pd: platform data passed in from the platform/machine
258  * @phy_chans: array of data for the physical channels
259  * @pool: a pool for the LLI descriptors
260  * @lli_buses: bitmask to or in to LLI pointer selecting AHB port for LLI
261  * fetches
262  * @mem_buses: set to indicate memory transfers on AHB2.
263  * @lock: a spinlock for this struct
264  */
265 struct pl08x_driver_data {
266 	struct dma_device slave;
267 	struct dma_device memcpy;
268 	void __iomem *base;
269 	struct amba_device *adev;
270 	const struct vendor_data *vd;
271 	struct pl08x_platform_data *pd;
272 	struct pl08x_phy_chan *phy_chans;
273 	struct dma_pool *pool;
274 	u8 lli_buses;
275 	u8 mem_buses;
276 	u8 lli_words;
277 };
278 
279 /*
280  * PL08X specific defines
281  */
282 
283 /* The order of words in an LLI. */
284 #define PL080_LLI_SRC		0
285 #define PL080_LLI_DST		1
286 #define PL080_LLI_LLI		2
287 #define PL080_LLI_CCTL		3
288 #define PL080S_LLI_CCTL2	4
289 
290 /* Total words in an LLI. */
291 #define PL080_LLI_WORDS		4
292 #define PL080S_LLI_WORDS	8
293 
294 /*
295  * Number of LLIs in each LLI buffer allocated for one transfer
296  * (maximum times we call dma_pool_alloc on this pool without freeing)
297  */
298 #define MAX_NUM_TSFR_LLIS	512
299 #define PL08X_ALIGN		8
300 
301 static inline struct pl08x_dma_chan *to_pl08x_chan(struct dma_chan *chan)
302 {
303 	return container_of(chan, struct pl08x_dma_chan, vc.chan);
304 }
305 
306 static inline struct pl08x_txd *to_pl08x_txd(struct dma_async_tx_descriptor *tx)
307 {
308 	return container_of(tx, struct pl08x_txd, vd.tx);
309 }
310 
311 /*
312  * Mux handling.
313  *
314  * This gives us the DMA request input to the PL08x primecell which the
315  * peripheral described by the channel data will be routed to, possibly
316  * via a board/SoC specific external MUX.  One important point to note
317  * here is that this does not depend on the physical channel.
318  */
319 static int pl08x_request_mux(struct pl08x_dma_chan *plchan)
320 {
321 	const struct pl08x_platform_data *pd = plchan->host->pd;
322 	int ret;
323 
324 	if (plchan->mux_use++ == 0 && pd->get_xfer_signal) {
325 		ret = pd->get_xfer_signal(plchan->cd);
326 		if (ret < 0) {
327 			plchan->mux_use = 0;
328 			return ret;
329 		}
330 
331 		plchan->signal = ret;
332 	}
333 	return 0;
334 }
335 
336 static void pl08x_release_mux(struct pl08x_dma_chan *plchan)
337 {
338 	const struct pl08x_platform_data *pd = plchan->host->pd;
339 
340 	if (plchan->signal >= 0) {
341 		WARN_ON(plchan->mux_use == 0);
342 
343 		if (--plchan->mux_use == 0 && pd->put_xfer_signal) {
344 			pd->put_xfer_signal(plchan->cd, plchan->signal);
345 			plchan->signal = -1;
346 		}
347 	}
348 }
349 
350 /*
351  * Physical channel handling
352  */
353 
354 /* Whether a certain channel is busy or not */
355 static int pl08x_phy_channel_busy(struct pl08x_phy_chan *ch)
356 {
357 	unsigned int val;
358 
359 	val = readl(ch->reg_config);
360 	return val & PL080_CONFIG_ACTIVE;
361 }
362 
363 static void pl08x_write_lli(struct pl08x_driver_data *pl08x,
364 		struct pl08x_phy_chan *phychan, const u32 *lli, u32 ccfg)
365 {
366 	if (pl08x->vd->pl080s)
367 		dev_vdbg(&pl08x->adev->dev,
368 			"WRITE channel %d: csrc=0x%08x, cdst=0x%08x, "
369 			"clli=0x%08x, cctl=0x%08x, cctl2=0x%08x, ccfg=0x%08x\n",
370 			phychan->id, lli[PL080_LLI_SRC], lli[PL080_LLI_DST],
371 			lli[PL080_LLI_LLI], lli[PL080_LLI_CCTL],
372 			lli[PL080S_LLI_CCTL2], ccfg);
373 	else
374 		dev_vdbg(&pl08x->adev->dev,
375 			"WRITE channel %d: csrc=0x%08x, cdst=0x%08x, "
376 			"clli=0x%08x, cctl=0x%08x, ccfg=0x%08x\n",
377 			phychan->id, lli[PL080_LLI_SRC], lli[PL080_LLI_DST],
378 			lli[PL080_LLI_LLI], lli[PL080_LLI_CCTL], ccfg);
379 
380 	writel_relaxed(lli[PL080_LLI_SRC], phychan->base + PL080_CH_SRC_ADDR);
381 	writel_relaxed(lli[PL080_LLI_DST], phychan->base + PL080_CH_DST_ADDR);
382 	writel_relaxed(lli[PL080_LLI_LLI], phychan->base + PL080_CH_LLI);
383 	writel_relaxed(lli[PL080_LLI_CCTL], phychan->base + PL080_CH_CONTROL);
384 
385 	if (pl08x->vd->pl080s)
386 		writel_relaxed(lli[PL080S_LLI_CCTL2],
387 				phychan->base + PL080S_CH_CONTROL2);
388 
389 	writel(ccfg, phychan->reg_config);
390 }
391 
392 /*
393  * Set the initial DMA register values i.e. those for the first LLI
394  * The next LLI pointer and the configuration interrupt bit have
395  * been set when the LLIs were constructed.  Poke them into the hardware
396  * and start the transfer.
397  */
398 static void pl08x_start_next_txd(struct pl08x_dma_chan *plchan)
399 {
400 	struct pl08x_driver_data *pl08x = plchan->host;
401 	struct pl08x_phy_chan *phychan = plchan->phychan;
402 	struct virt_dma_desc *vd = vchan_next_desc(&plchan->vc);
403 	struct pl08x_txd *txd = to_pl08x_txd(&vd->tx);
404 	u32 val;
405 
406 	list_del(&txd->vd.node);
407 
408 	plchan->at = txd;
409 
410 	/* Wait for channel inactive */
411 	while (pl08x_phy_channel_busy(phychan))
412 		cpu_relax();
413 
414 	pl08x_write_lli(pl08x, phychan, &txd->llis_va[0], txd->ccfg);
415 
416 	/* Enable the DMA channel */
417 	/* Do not access config register until channel shows as disabled */
418 	while (readl(pl08x->base + PL080_EN_CHAN) & (1 << phychan->id))
419 		cpu_relax();
420 
421 	/* Do not access config register until channel shows as inactive */
422 	val = readl(phychan->reg_config);
423 	while ((val & PL080_CONFIG_ACTIVE) || (val & PL080_CONFIG_ENABLE))
424 		val = readl(phychan->reg_config);
425 
426 	writel(val | PL080_CONFIG_ENABLE, phychan->reg_config);
427 }
428 
429 /*
430  * Pause the channel by setting the HALT bit.
431  *
432  * For M->P transfers, pause the DMAC first and then stop the peripheral -
433  * the FIFO can only drain if the peripheral is still requesting data.
434  * (note: this can still timeout if the DMAC FIFO never drains of data.)
435  *
436  * For P->M transfers, disable the peripheral first to stop it filling
437  * the DMAC FIFO, and then pause the DMAC.
438  */
439 static void pl08x_pause_phy_chan(struct pl08x_phy_chan *ch)
440 {
441 	u32 val;
442 	int timeout;
443 
444 	/* Set the HALT bit and wait for the FIFO to drain */
445 	val = readl(ch->reg_config);
446 	val |= PL080_CONFIG_HALT;
447 	writel(val, ch->reg_config);
448 
449 	/* Wait for channel inactive */
450 	for (timeout = 1000; timeout; timeout--) {
451 		if (!pl08x_phy_channel_busy(ch))
452 			break;
453 		udelay(1);
454 	}
455 	if (pl08x_phy_channel_busy(ch))
456 		pr_err("pl08x: channel%u timeout waiting for pause\n", ch->id);
457 }
458 
459 static void pl08x_resume_phy_chan(struct pl08x_phy_chan *ch)
460 {
461 	u32 val;
462 
463 	/* Clear the HALT bit */
464 	val = readl(ch->reg_config);
465 	val &= ~PL080_CONFIG_HALT;
466 	writel(val, ch->reg_config);
467 }
468 
469 /*
470  * pl08x_terminate_phy_chan() stops the channel, clears the FIFO and
471  * clears any pending interrupt status.  This should not be used for
472  * an on-going transfer, but as a method of shutting down a channel
473  * (eg, when it's no longer used) or terminating a transfer.
474  */
475 static void pl08x_terminate_phy_chan(struct pl08x_driver_data *pl08x,
476 	struct pl08x_phy_chan *ch)
477 {
478 	u32 val = readl(ch->reg_config);
479 
480 	val &= ~(PL080_CONFIG_ENABLE | PL080_CONFIG_ERR_IRQ_MASK |
481 	         PL080_CONFIG_TC_IRQ_MASK);
482 
483 	writel(val, ch->reg_config);
484 
485 	writel(1 << ch->id, pl08x->base + PL080_ERR_CLEAR);
486 	writel(1 << ch->id, pl08x->base + PL080_TC_CLEAR);
487 }
488 
489 static inline u32 get_bytes_in_cctl(u32 cctl)
490 {
491 	/* The source width defines the number of bytes */
492 	u32 bytes = cctl & PL080_CONTROL_TRANSFER_SIZE_MASK;
493 
494 	cctl &= PL080_CONTROL_SWIDTH_MASK;
495 
496 	switch (cctl >> PL080_CONTROL_SWIDTH_SHIFT) {
497 	case PL080_WIDTH_8BIT:
498 		break;
499 	case PL080_WIDTH_16BIT:
500 		bytes *= 2;
501 		break;
502 	case PL080_WIDTH_32BIT:
503 		bytes *= 4;
504 		break;
505 	}
506 	return bytes;
507 }
508 
509 static inline u32 get_bytes_in_cctl_pl080s(u32 cctl, u32 cctl1)
510 {
511 	/* The source width defines the number of bytes */
512 	u32 bytes = cctl1 & PL080S_CONTROL_TRANSFER_SIZE_MASK;
513 
514 	cctl &= PL080_CONTROL_SWIDTH_MASK;
515 
516 	switch (cctl >> PL080_CONTROL_SWIDTH_SHIFT) {
517 	case PL080_WIDTH_8BIT:
518 		break;
519 	case PL080_WIDTH_16BIT:
520 		bytes *= 2;
521 		break;
522 	case PL080_WIDTH_32BIT:
523 		bytes *= 4;
524 		break;
525 	}
526 	return bytes;
527 }
528 
529 /* The channel should be paused when calling this */
530 static u32 pl08x_getbytes_chan(struct pl08x_dma_chan *plchan)
531 {
532 	struct pl08x_driver_data *pl08x = plchan->host;
533 	const u32 *llis_va, *llis_va_limit;
534 	struct pl08x_phy_chan *ch;
535 	dma_addr_t llis_bus;
536 	struct pl08x_txd *txd;
537 	u32 llis_max_words;
538 	size_t bytes;
539 	u32 clli;
540 
541 	ch = plchan->phychan;
542 	txd = plchan->at;
543 
544 	if (!ch || !txd)
545 		return 0;
546 
547 	/*
548 	 * Follow the LLIs to get the number of remaining
549 	 * bytes in the currently active transaction.
550 	 */
551 	clli = readl(ch->base + PL080_CH_LLI) & ~PL080_LLI_LM_AHB2;
552 
553 	/* First get the remaining bytes in the active transfer */
554 	if (pl08x->vd->pl080s)
555 		bytes = get_bytes_in_cctl_pl080s(
556 				readl(ch->base + PL080_CH_CONTROL),
557 				readl(ch->base + PL080S_CH_CONTROL2));
558 	else
559 		bytes = get_bytes_in_cctl(readl(ch->base + PL080_CH_CONTROL));
560 
561 	if (!clli)
562 		return bytes;
563 
564 	llis_va = txd->llis_va;
565 	llis_bus = txd->llis_bus;
566 
567 	llis_max_words = pl08x->lli_words * MAX_NUM_TSFR_LLIS;
568 	BUG_ON(clli < llis_bus || clli >= llis_bus +
569 						sizeof(u32) * llis_max_words);
570 
571 	/*
572 	 * Locate the next LLI - as this is an array,
573 	 * it's simple maths to find.
574 	 */
575 	llis_va += (clli - llis_bus) / sizeof(u32);
576 
577 	llis_va_limit = llis_va + llis_max_words;
578 
579 	for (; llis_va < llis_va_limit; llis_va += pl08x->lli_words) {
580 		if (pl08x->vd->pl080s)
581 			bytes += get_bytes_in_cctl_pl080s(
582 						llis_va[PL080_LLI_CCTL],
583 						llis_va[PL080S_LLI_CCTL2]);
584 		else
585 			bytes += get_bytes_in_cctl(llis_va[PL080_LLI_CCTL]);
586 
587 		/*
588 		 * A LLI pointer going backward terminates the LLI list
589 		 */
590 		if (llis_va[PL080_LLI_LLI] <= clli)
591 			break;
592 	}
593 
594 	return bytes;
595 }
596 
597 /*
598  * Allocate a physical channel for a virtual channel
599  *
600  * Try to locate a physical channel to be used for this transfer. If all
601  * are taken return NULL and the requester will have to cope by using
602  * some fallback PIO mode or retrying later.
603  */
604 static struct pl08x_phy_chan *
605 pl08x_get_phy_channel(struct pl08x_driver_data *pl08x,
606 		      struct pl08x_dma_chan *virt_chan)
607 {
608 	struct pl08x_phy_chan *ch = NULL;
609 	unsigned long flags;
610 	int i;
611 
612 	for (i = 0; i < pl08x->vd->channels; i++) {
613 		ch = &pl08x->phy_chans[i];
614 
615 		spin_lock_irqsave(&ch->lock, flags);
616 
617 		if (!ch->locked && !ch->serving) {
618 			ch->serving = virt_chan;
619 			spin_unlock_irqrestore(&ch->lock, flags);
620 			break;
621 		}
622 
623 		spin_unlock_irqrestore(&ch->lock, flags);
624 	}
625 
626 	if (i == pl08x->vd->channels) {
627 		/* No physical channel available, cope with it */
628 		return NULL;
629 	}
630 
631 	return ch;
632 }
633 
634 /* Mark the physical channel as free.  Note, this write is atomic. */
635 static inline void pl08x_put_phy_channel(struct pl08x_driver_data *pl08x,
636 					 struct pl08x_phy_chan *ch)
637 {
638 	ch->serving = NULL;
639 }
640 
641 /*
642  * Try to allocate a physical channel.  When successful, assign it to
643  * this virtual channel, and initiate the next descriptor.  The
644  * virtual channel lock must be held at this point.
645  */
646 static void pl08x_phy_alloc_and_start(struct pl08x_dma_chan *plchan)
647 {
648 	struct pl08x_driver_data *pl08x = plchan->host;
649 	struct pl08x_phy_chan *ch;
650 
651 	ch = pl08x_get_phy_channel(pl08x, plchan);
652 	if (!ch) {
653 		dev_dbg(&pl08x->adev->dev, "no physical channel available for xfer on %s\n", plchan->name);
654 		plchan->state = PL08X_CHAN_WAITING;
655 		return;
656 	}
657 
658 	dev_dbg(&pl08x->adev->dev, "allocated physical channel %d for xfer on %s\n",
659 		ch->id, plchan->name);
660 
661 	plchan->phychan = ch;
662 	plchan->state = PL08X_CHAN_RUNNING;
663 	pl08x_start_next_txd(plchan);
664 }
665 
666 static void pl08x_phy_reassign_start(struct pl08x_phy_chan *ch,
667 	struct pl08x_dma_chan *plchan)
668 {
669 	struct pl08x_driver_data *pl08x = plchan->host;
670 
671 	dev_dbg(&pl08x->adev->dev, "reassigned physical channel %d for xfer on %s\n",
672 		ch->id, plchan->name);
673 
674 	/*
675 	 * We do this without taking the lock; we're really only concerned
676 	 * about whether this pointer is NULL or not, and we're guaranteed
677 	 * that this will only be called when it _already_ is non-NULL.
678 	 */
679 	ch->serving = plchan;
680 	plchan->phychan = ch;
681 	plchan->state = PL08X_CHAN_RUNNING;
682 	pl08x_start_next_txd(plchan);
683 }
684 
685 /*
686  * Free a physical DMA channel, potentially reallocating it to another
687  * virtual channel if we have any pending.
688  */
689 static void pl08x_phy_free(struct pl08x_dma_chan *plchan)
690 {
691 	struct pl08x_driver_data *pl08x = plchan->host;
692 	struct pl08x_dma_chan *p, *next;
693 
694  retry:
695 	next = NULL;
696 
697 	/* Find a waiting virtual channel for the next transfer. */
698 	list_for_each_entry(p, &pl08x->memcpy.channels, vc.chan.device_node)
699 		if (p->state == PL08X_CHAN_WAITING) {
700 			next = p;
701 			break;
702 		}
703 
704 	if (!next) {
705 		list_for_each_entry(p, &pl08x->slave.channels, vc.chan.device_node)
706 			if (p->state == PL08X_CHAN_WAITING) {
707 				next = p;
708 				break;
709 			}
710 	}
711 
712 	/* Ensure that the physical channel is stopped */
713 	pl08x_terminate_phy_chan(pl08x, plchan->phychan);
714 
715 	if (next) {
716 		bool success;
717 
718 		/*
719 		 * Eww.  We know this isn't going to deadlock
720 		 * but lockdep probably doesn't.
721 		 */
722 		spin_lock(&next->vc.lock);
723 		/* Re-check the state now that we have the lock */
724 		success = next->state == PL08X_CHAN_WAITING;
725 		if (success)
726 			pl08x_phy_reassign_start(plchan->phychan, next);
727 		spin_unlock(&next->vc.lock);
728 
729 		/* If the state changed, try to find another channel */
730 		if (!success)
731 			goto retry;
732 	} else {
733 		/* No more jobs, so free up the physical channel */
734 		pl08x_put_phy_channel(pl08x, plchan->phychan);
735 	}
736 
737 	plchan->phychan = NULL;
738 	plchan->state = PL08X_CHAN_IDLE;
739 }
740 
741 /*
742  * LLI handling
743  */
744 
745 static inline unsigned int pl08x_get_bytes_for_cctl(unsigned int coded)
746 {
747 	switch (coded) {
748 	case PL080_WIDTH_8BIT:
749 		return 1;
750 	case PL080_WIDTH_16BIT:
751 		return 2;
752 	case PL080_WIDTH_32BIT:
753 		return 4;
754 	default:
755 		break;
756 	}
757 	BUG();
758 	return 0;
759 }
760 
761 static inline u32 pl08x_cctl_bits(u32 cctl, u8 srcwidth, u8 dstwidth,
762 				  size_t tsize)
763 {
764 	u32 retbits = cctl;
765 
766 	/* Remove all src, dst and transfer size bits */
767 	retbits &= ~PL080_CONTROL_DWIDTH_MASK;
768 	retbits &= ~PL080_CONTROL_SWIDTH_MASK;
769 	retbits &= ~PL080_CONTROL_TRANSFER_SIZE_MASK;
770 
771 	/* Then set the bits according to the parameters */
772 	switch (srcwidth) {
773 	case 1:
774 		retbits |= PL080_WIDTH_8BIT << PL080_CONTROL_SWIDTH_SHIFT;
775 		break;
776 	case 2:
777 		retbits |= PL080_WIDTH_16BIT << PL080_CONTROL_SWIDTH_SHIFT;
778 		break;
779 	case 4:
780 		retbits |= PL080_WIDTH_32BIT << PL080_CONTROL_SWIDTH_SHIFT;
781 		break;
782 	default:
783 		BUG();
784 		break;
785 	}
786 
787 	switch (dstwidth) {
788 	case 1:
789 		retbits |= PL080_WIDTH_8BIT << PL080_CONTROL_DWIDTH_SHIFT;
790 		break;
791 	case 2:
792 		retbits |= PL080_WIDTH_16BIT << PL080_CONTROL_DWIDTH_SHIFT;
793 		break;
794 	case 4:
795 		retbits |= PL080_WIDTH_32BIT << PL080_CONTROL_DWIDTH_SHIFT;
796 		break;
797 	default:
798 		BUG();
799 		break;
800 	}
801 
802 	tsize &= PL080_CONTROL_TRANSFER_SIZE_MASK;
803 	retbits |= tsize << PL080_CONTROL_TRANSFER_SIZE_SHIFT;
804 	return retbits;
805 }
806 
807 struct pl08x_lli_build_data {
808 	struct pl08x_txd *txd;
809 	struct pl08x_bus_data srcbus;
810 	struct pl08x_bus_data dstbus;
811 	size_t remainder;
812 	u32 lli_bus;
813 };
814 
815 /*
816  * Autoselect a master bus to use for the transfer. Slave will be the chosen as
817  * victim in case src & dest are not similarly aligned. i.e. If after aligning
818  * masters address with width requirements of transfer (by sending few byte by
819  * byte data), slave is still not aligned, then its width will be reduced to
820  * BYTE.
821  * - prefers the destination bus if both available
822  * - prefers bus with fixed address (i.e. peripheral)
823  */
824 static void pl08x_choose_master_bus(struct pl08x_lli_build_data *bd,
825 	struct pl08x_bus_data **mbus, struct pl08x_bus_data **sbus, u32 cctl)
826 {
827 	if (!(cctl & PL080_CONTROL_DST_INCR)) {
828 		*mbus = &bd->dstbus;
829 		*sbus = &bd->srcbus;
830 	} else if (!(cctl & PL080_CONTROL_SRC_INCR)) {
831 		*mbus = &bd->srcbus;
832 		*sbus = &bd->dstbus;
833 	} else {
834 		if (bd->dstbus.buswidth >= bd->srcbus.buswidth) {
835 			*mbus = &bd->dstbus;
836 			*sbus = &bd->srcbus;
837 		} else {
838 			*mbus = &bd->srcbus;
839 			*sbus = &bd->dstbus;
840 		}
841 	}
842 }
843 
844 /*
845  * Fills in one LLI for a certain transfer descriptor and advance the counter
846  */
847 static void pl08x_fill_lli_for_desc(struct pl08x_driver_data *pl08x,
848 				    struct pl08x_lli_build_data *bd,
849 				    int num_llis, int len, u32 cctl, u32 cctl2)
850 {
851 	u32 offset = num_llis * pl08x->lli_words;
852 	u32 *llis_va = bd->txd->llis_va + offset;
853 	dma_addr_t llis_bus = bd->txd->llis_bus;
854 
855 	BUG_ON(num_llis >= MAX_NUM_TSFR_LLIS);
856 
857 	/* Advance the offset to next LLI. */
858 	offset += pl08x->lli_words;
859 
860 	llis_va[PL080_LLI_SRC] = bd->srcbus.addr;
861 	llis_va[PL080_LLI_DST] = bd->dstbus.addr;
862 	llis_va[PL080_LLI_LLI] = (llis_bus + sizeof(u32) * offset);
863 	llis_va[PL080_LLI_LLI] |= bd->lli_bus;
864 	llis_va[PL080_LLI_CCTL] = cctl;
865 	if (pl08x->vd->pl080s)
866 		llis_va[PL080S_LLI_CCTL2] = cctl2;
867 
868 	if (cctl & PL080_CONTROL_SRC_INCR)
869 		bd->srcbus.addr += len;
870 	if (cctl & PL080_CONTROL_DST_INCR)
871 		bd->dstbus.addr += len;
872 
873 	BUG_ON(bd->remainder < len);
874 
875 	bd->remainder -= len;
876 }
877 
878 static inline void prep_byte_width_lli(struct pl08x_driver_data *pl08x,
879 			struct pl08x_lli_build_data *bd, u32 *cctl, u32 len,
880 			int num_llis, size_t *total_bytes)
881 {
882 	*cctl = pl08x_cctl_bits(*cctl, 1, 1, len);
883 	pl08x_fill_lli_for_desc(pl08x, bd, num_llis, len, *cctl, len);
884 	(*total_bytes) += len;
885 }
886 
887 #ifdef VERBOSE_DEBUG
888 static void pl08x_dump_lli(struct pl08x_driver_data *pl08x,
889 			   const u32 *llis_va, int num_llis)
890 {
891 	int i;
892 
893 	if (pl08x->vd->pl080s) {
894 		dev_vdbg(&pl08x->adev->dev,
895 			"%-3s %-9s  %-10s %-10s %-10s %-10s %s\n",
896 			"lli", "", "csrc", "cdst", "clli", "cctl", "cctl2");
897 		for (i = 0; i < num_llis; i++) {
898 			dev_vdbg(&pl08x->adev->dev,
899 				"%3d @%p: 0x%08x 0x%08x 0x%08x 0x%08x 0x%08x\n",
900 				i, llis_va, llis_va[PL080_LLI_SRC],
901 				llis_va[PL080_LLI_DST], llis_va[PL080_LLI_LLI],
902 				llis_va[PL080_LLI_CCTL],
903 				llis_va[PL080S_LLI_CCTL2]);
904 			llis_va += pl08x->lli_words;
905 		}
906 	} else {
907 		dev_vdbg(&pl08x->adev->dev,
908 			"%-3s %-9s  %-10s %-10s %-10s %s\n",
909 			"lli", "", "csrc", "cdst", "clli", "cctl");
910 		for (i = 0; i < num_llis; i++) {
911 			dev_vdbg(&pl08x->adev->dev,
912 				"%3d @%p: 0x%08x 0x%08x 0x%08x 0x%08x\n",
913 				i, llis_va, llis_va[PL080_LLI_SRC],
914 				llis_va[PL080_LLI_DST], llis_va[PL080_LLI_LLI],
915 				llis_va[PL080_LLI_CCTL]);
916 			llis_va += pl08x->lli_words;
917 		}
918 	}
919 }
920 #else
921 static inline void pl08x_dump_lli(struct pl08x_driver_data *pl08x,
922 				  const u32 *llis_va, int num_llis) {}
923 #endif
924 
925 /*
926  * This fills in the table of LLIs for the transfer descriptor
927  * Note that we assume we never have to change the burst sizes
928  * Return 0 for error
929  */
930 static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
931 			      struct pl08x_txd *txd)
932 {
933 	struct pl08x_bus_data *mbus, *sbus;
934 	struct pl08x_lli_build_data bd;
935 	int num_llis = 0;
936 	u32 cctl, early_bytes = 0;
937 	size_t max_bytes_per_lli, total_bytes;
938 	u32 *llis_va, *last_lli;
939 	struct pl08x_sg *dsg;
940 
941 	txd->llis_va = dma_pool_alloc(pl08x->pool, GFP_NOWAIT, &txd->llis_bus);
942 	if (!txd->llis_va) {
943 		dev_err(&pl08x->adev->dev, "%s no memory for llis\n", __func__);
944 		return 0;
945 	}
946 
947 	bd.txd = txd;
948 	bd.lli_bus = (pl08x->lli_buses & PL08X_AHB2) ? PL080_LLI_LM_AHB2 : 0;
949 	cctl = txd->cctl;
950 
951 	/* Find maximum width of the source bus */
952 	bd.srcbus.maxwidth =
953 		pl08x_get_bytes_for_cctl((cctl & PL080_CONTROL_SWIDTH_MASK) >>
954 				       PL080_CONTROL_SWIDTH_SHIFT);
955 
956 	/* Find maximum width of the destination bus */
957 	bd.dstbus.maxwidth =
958 		pl08x_get_bytes_for_cctl((cctl & PL080_CONTROL_DWIDTH_MASK) >>
959 				       PL080_CONTROL_DWIDTH_SHIFT);
960 
961 	list_for_each_entry(dsg, &txd->dsg_list, node) {
962 		total_bytes = 0;
963 		cctl = txd->cctl;
964 
965 		bd.srcbus.addr = dsg->src_addr;
966 		bd.dstbus.addr = dsg->dst_addr;
967 		bd.remainder = dsg->len;
968 		bd.srcbus.buswidth = bd.srcbus.maxwidth;
969 		bd.dstbus.buswidth = bd.dstbus.maxwidth;
970 
971 		pl08x_choose_master_bus(&bd, &mbus, &sbus, cctl);
972 
973 		dev_vdbg(&pl08x->adev->dev,
974 			"src=0x%08llx%s/%u dst=0x%08llx%s/%u len=%zu\n",
975 			(u64)bd.srcbus.addr,
976 			cctl & PL080_CONTROL_SRC_INCR ? "+" : "",
977 			bd.srcbus.buswidth,
978 			(u64)bd.dstbus.addr,
979 			cctl & PL080_CONTROL_DST_INCR ? "+" : "",
980 			bd.dstbus.buswidth,
981 			bd.remainder);
982 		dev_vdbg(&pl08x->adev->dev, "mbus=%s sbus=%s\n",
983 			mbus == &bd.srcbus ? "src" : "dst",
984 			sbus == &bd.srcbus ? "src" : "dst");
985 
986 		/*
987 		 * Zero length is only allowed if all these requirements are
988 		 * met:
989 		 * - flow controller is peripheral.
990 		 * - src.addr is aligned to src.width
991 		 * - dst.addr is aligned to dst.width
992 		 *
993 		 * sg_len == 1 should be true, as there can be two cases here:
994 		 *
995 		 * - Memory addresses are contiguous and are not scattered.
996 		 *   Here, Only one sg will be passed by user driver, with
997 		 *   memory address and zero length. We pass this to controller
998 		 *   and after the transfer it will receive the last burst
999 		 *   request from peripheral and so transfer finishes.
1000 		 *
1001 		 * - Memory addresses are scattered and are not contiguous.
1002 		 *   Here, Obviously as DMA controller doesn't know when a lli's
1003 		 *   transfer gets over, it can't load next lli. So in this
1004 		 *   case, there has to be an assumption that only one lli is
1005 		 *   supported. Thus, we can't have scattered addresses.
1006 		 */
1007 		if (!bd.remainder) {
1008 			u32 fc = (txd->ccfg & PL080_CONFIG_FLOW_CONTROL_MASK) >>
1009 				PL080_CONFIG_FLOW_CONTROL_SHIFT;
1010 			if (!((fc >= PL080_FLOW_SRC2DST_DST) &&
1011 					(fc <= PL080_FLOW_SRC2DST_SRC))) {
1012 				dev_err(&pl08x->adev->dev, "%s sg len can't be zero",
1013 					__func__);
1014 				return 0;
1015 			}
1016 
1017 			if (!IS_BUS_ALIGNED(&bd.srcbus) ||
1018 				!IS_BUS_ALIGNED(&bd.dstbus)) {
1019 				dev_err(&pl08x->adev->dev,
1020 					"%s src & dst address must be aligned to src"
1021 					" & dst width if peripheral is flow controller",
1022 					__func__);
1023 				return 0;
1024 			}
1025 
1026 			cctl = pl08x_cctl_bits(cctl, bd.srcbus.buswidth,
1027 					bd.dstbus.buswidth, 0);
1028 			pl08x_fill_lli_for_desc(pl08x, &bd, num_llis++,
1029 					0, cctl, 0);
1030 			break;
1031 		}
1032 
1033 		/*
1034 		 * Send byte by byte for following cases
1035 		 * - Less than a bus width available
1036 		 * - until master bus is aligned
1037 		 */
1038 		if (bd.remainder < mbus->buswidth)
1039 			early_bytes = bd.remainder;
1040 		else if (!IS_BUS_ALIGNED(mbus)) {
1041 			early_bytes = mbus->buswidth -
1042 				(mbus->addr & (mbus->buswidth - 1));
1043 			if ((bd.remainder - early_bytes) < mbus->buswidth)
1044 				early_bytes = bd.remainder;
1045 		}
1046 
1047 		if (early_bytes) {
1048 			dev_vdbg(&pl08x->adev->dev,
1049 				"%s byte width LLIs (remain 0x%08zx)\n",
1050 				__func__, bd.remainder);
1051 			prep_byte_width_lli(pl08x, &bd, &cctl, early_bytes,
1052 				num_llis++, &total_bytes);
1053 		}
1054 
1055 		if (bd.remainder) {
1056 			/*
1057 			 * Master now aligned
1058 			 * - if slave is not then we must set its width down
1059 			 */
1060 			if (!IS_BUS_ALIGNED(sbus)) {
1061 				dev_dbg(&pl08x->adev->dev,
1062 					"%s set down bus width to one byte\n",
1063 					__func__);
1064 
1065 				sbus->buswidth = 1;
1066 			}
1067 
1068 			/*
1069 			 * Bytes transferred = tsize * src width, not
1070 			 * MIN(buswidths)
1071 			 */
1072 			max_bytes_per_lli = bd.srcbus.buswidth *
1073 						pl08x->vd->max_transfer_size;
1074 			dev_vdbg(&pl08x->adev->dev,
1075 				"%s max bytes per lli = %zu\n",
1076 				__func__, max_bytes_per_lli);
1077 
1078 			/*
1079 			 * Make largest possible LLIs until less than one bus
1080 			 * width left
1081 			 */
1082 			while (bd.remainder > (mbus->buswidth - 1)) {
1083 				size_t lli_len, tsize, width;
1084 
1085 				/*
1086 				 * If enough left try to send max possible,
1087 				 * otherwise try to send the remainder
1088 				 */
1089 				lli_len = min(bd.remainder, max_bytes_per_lli);
1090 
1091 				/*
1092 				 * Check against maximum bus alignment:
1093 				 * Calculate actual transfer size in relation to
1094 				 * bus width an get a maximum remainder of the
1095 				 * highest bus width - 1
1096 				 */
1097 				width = max(mbus->buswidth, sbus->buswidth);
1098 				lli_len = (lli_len / width) * width;
1099 				tsize = lli_len / bd.srcbus.buswidth;
1100 
1101 				dev_vdbg(&pl08x->adev->dev,
1102 					"%s fill lli with single lli chunk of "
1103 					"size 0x%08zx (remainder 0x%08zx)\n",
1104 					__func__, lli_len, bd.remainder);
1105 
1106 				cctl = pl08x_cctl_bits(cctl, bd.srcbus.buswidth,
1107 					bd.dstbus.buswidth, tsize);
1108 				pl08x_fill_lli_for_desc(pl08x, &bd, num_llis++,
1109 						lli_len, cctl, tsize);
1110 				total_bytes += lli_len;
1111 			}
1112 
1113 			/*
1114 			 * Send any odd bytes
1115 			 */
1116 			if (bd.remainder) {
1117 				dev_vdbg(&pl08x->adev->dev,
1118 					"%s align with boundary, send odd bytes (remain %zu)\n",
1119 					__func__, bd.remainder);
1120 				prep_byte_width_lli(pl08x, &bd, &cctl,
1121 					bd.remainder, num_llis++, &total_bytes);
1122 			}
1123 		}
1124 
1125 		if (total_bytes != dsg->len) {
1126 			dev_err(&pl08x->adev->dev,
1127 				"%s size of encoded lli:s don't match total txd, transferred 0x%08zx from size 0x%08zx\n",
1128 				__func__, total_bytes, dsg->len);
1129 			return 0;
1130 		}
1131 
1132 		if (num_llis >= MAX_NUM_TSFR_LLIS) {
1133 			dev_err(&pl08x->adev->dev,
1134 				"%s need to increase MAX_NUM_TSFR_LLIS from 0x%08x\n",
1135 				__func__, MAX_NUM_TSFR_LLIS);
1136 			return 0;
1137 		}
1138 	}
1139 
1140 	llis_va = txd->llis_va;
1141 	last_lli = llis_va + (num_llis - 1) * pl08x->lli_words;
1142 
1143 	if (txd->cyclic) {
1144 		/* Link back to the first LLI. */
1145 		last_lli[PL080_LLI_LLI] = txd->llis_bus | bd.lli_bus;
1146 	} else {
1147 		/* The final LLI terminates the LLI. */
1148 		last_lli[PL080_LLI_LLI] = 0;
1149 		/* The final LLI element shall also fire an interrupt. */
1150 		last_lli[PL080_LLI_CCTL] |= PL080_CONTROL_TC_IRQ_EN;
1151 	}
1152 
1153 	pl08x_dump_lli(pl08x, llis_va, num_llis);
1154 
1155 	return num_llis;
1156 }
1157 
1158 static void pl08x_free_txd(struct pl08x_driver_data *pl08x,
1159 			   struct pl08x_txd *txd)
1160 {
1161 	struct pl08x_sg *dsg, *_dsg;
1162 
1163 	if (txd->llis_va)
1164 		dma_pool_free(pl08x->pool, txd->llis_va, txd->llis_bus);
1165 
1166 	list_for_each_entry_safe(dsg, _dsg, &txd->dsg_list, node) {
1167 		list_del(&dsg->node);
1168 		kfree(dsg);
1169 	}
1170 
1171 	kfree(txd);
1172 }
1173 
1174 static void pl08x_desc_free(struct virt_dma_desc *vd)
1175 {
1176 	struct pl08x_txd *txd = to_pl08x_txd(&vd->tx);
1177 	struct pl08x_dma_chan *plchan = to_pl08x_chan(vd->tx.chan);
1178 
1179 	dma_descriptor_unmap(&vd->tx);
1180 	if (!txd->done)
1181 		pl08x_release_mux(plchan);
1182 
1183 	pl08x_free_txd(plchan->host, txd);
1184 }
1185 
1186 static void pl08x_free_txd_list(struct pl08x_driver_data *pl08x,
1187 				struct pl08x_dma_chan *plchan)
1188 {
1189 	LIST_HEAD(head);
1190 
1191 	vchan_get_all_descriptors(&plchan->vc, &head);
1192 	vchan_dma_desc_free_list(&plchan->vc, &head);
1193 }
1194 
1195 /*
1196  * The DMA ENGINE API
1197  */
1198 static int pl08x_alloc_chan_resources(struct dma_chan *chan)
1199 {
1200 	return 0;
1201 }
1202 
1203 static void pl08x_free_chan_resources(struct dma_chan *chan)
1204 {
1205 	/* Ensure all queued descriptors are freed */
1206 	vchan_free_chan_resources(to_virt_chan(chan));
1207 }
1208 
1209 static struct dma_async_tx_descriptor *pl08x_prep_dma_interrupt(
1210 		struct dma_chan *chan, unsigned long flags)
1211 {
1212 	struct dma_async_tx_descriptor *retval = NULL;
1213 
1214 	return retval;
1215 }
1216 
1217 /*
1218  * Code accessing dma_async_is_complete() in a tight loop may give problems.
1219  * If slaves are relying on interrupts to signal completion this function
1220  * must not be called with interrupts disabled.
1221  */
1222 static enum dma_status pl08x_dma_tx_status(struct dma_chan *chan,
1223 		dma_cookie_t cookie, struct dma_tx_state *txstate)
1224 {
1225 	struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
1226 	struct virt_dma_desc *vd;
1227 	unsigned long flags;
1228 	enum dma_status ret;
1229 	size_t bytes = 0;
1230 
1231 	ret = dma_cookie_status(chan, cookie, txstate);
1232 	if (ret == DMA_COMPLETE)
1233 		return ret;
1234 
1235 	/*
1236 	 * There's no point calculating the residue if there's
1237 	 * no txstate to store the value.
1238 	 */
1239 	if (!txstate) {
1240 		if (plchan->state == PL08X_CHAN_PAUSED)
1241 			ret = DMA_PAUSED;
1242 		return ret;
1243 	}
1244 
1245 	spin_lock_irqsave(&plchan->vc.lock, flags);
1246 	ret = dma_cookie_status(chan, cookie, txstate);
1247 	if (ret != DMA_COMPLETE) {
1248 		vd = vchan_find_desc(&plchan->vc, cookie);
1249 		if (vd) {
1250 			/* On the issued list, so hasn't been processed yet */
1251 			struct pl08x_txd *txd = to_pl08x_txd(&vd->tx);
1252 			struct pl08x_sg *dsg;
1253 
1254 			list_for_each_entry(dsg, &txd->dsg_list, node)
1255 				bytes += dsg->len;
1256 		} else {
1257 			bytes = pl08x_getbytes_chan(plchan);
1258 		}
1259 	}
1260 	spin_unlock_irqrestore(&plchan->vc.lock, flags);
1261 
1262 	/*
1263 	 * This cookie not complete yet
1264 	 * Get number of bytes left in the active transactions and queue
1265 	 */
1266 	dma_set_residue(txstate, bytes);
1267 
1268 	if (plchan->state == PL08X_CHAN_PAUSED && ret == DMA_IN_PROGRESS)
1269 		ret = DMA_PAUSED;
1270 
1271 	/* Whether waiting or running, we're in progress */
1272 	return ret;
1273 }
1274 
1275 /* PrimeCell DMA extension */
1276 struct burst_table {
1277 	u32 burstwords;
1278 	u32 reg;
1279 };
1280 
1281 static const struct burst_table burst_sizes[] = {
1282 	{
1283 		.burstwords = 256,
1284 		.reg = PL080_BSIZE_256,
1285 	},
1286 	{
1287 		.burstwords = 128,
1288 		.reg = PL080_BSIZE_128,
1289 	},
1290 	{
1291 		.burstwords = 64,
1292 		.reg = PL080_BSIZE_64,
1293 	},
1294 	{
1295 		.burstwords = 32,
1296 		.reg = PL080_BSIZE_32,
1297 	},
1298 	{
1299 		.burstwords = 16,
1300 		.reg = PL080_BSIZE_16,
1301 	},
1302 	{
1303 		.burstwords = 8,
1304 		.reg = PL080_BSIZE_8,
1305 	},
1306 	{
1307 		.burstwords = 4,
1308 		.reg = PL080_BSIZE_4,
1309 	},
1310 	{
1311 		.burstwords = 0,
1312 		.reg = PL080_BSIZE_1,
1313 	},
1314 };
1315 
1316 /*
1317  * Given the source and destination available bus masks, select which
1318  * will be routed to each port.  We try to have source and destination
1319  * on separate ports, but always respect the allowable settings.
1320  */
1321 static u32 pl08x_select_bus(u8 src, u8 dst)
1322 {
1323 	u32 cctl = 0;
1324 
1325 	if (!(dst & PL08X_AHB1) || ((dst & PL08X_AHB2) && (src & PL08X_AHB1)))
1326 		cctl |= PL080_CONTROL_DST_AHB2;
1327 	if (!(src & PL08X_AHB1) || ((src & PL08X_AHB2) && !(dst & PL08X_AHB2)))
1328 		cctl |= PL080_CONTROL_SRC_AHB2;
1329 
1330 	return cctl;
1331 }
1332 
1333 static u32 pl08x_cctl(u32 cctl)
1334 {
1335 	cctl &= ~(PL080_CONTROL_SRC_AHB2 | PL080_CONTROL_DST_AHB2 |
1336 		  PL080_CONTROL_SRC_INCR | PL080_CONTROL_DST_INCR |
1337 		  PL080_CONTROL_PROT_MASK);
1338 
1339 	/* Access the cell in privileged mode, non-bufferable, non-cacheable */
1340 	return cctl | PL080_CONTROL_PROT_SYS;
1341 }
1342 
1343 static u32 pl08x_width(enum dma_slave_buswidth width)
1344 {
1345 	switch (width) {
1346 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
1347 		return PL080_WIDTH_8BIT;
1348 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
1349 		return PL080_WIDTH_16BIT;
1350 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
1351 		return PL080_WIDTH_32BIT;
1352 	default:
1353 		return ~0;
1354 	}
1355 }
1356 
1357 static u32 pl08x_burst(u32 maxburst)
1358 {
1359 	int i;
1360 
1361 	for (i = 0; i < ARRAY_SIZE(burst_sizes); i++)
1362 		if (burst_sizes[i].burstwords <= maxburst)
1363 			break;
1364 
1365 	return burst_sizes[i].reg;
1366 }
1367 
1368 static u32 pl08x_get_cctl(struct pl08x_dma_chan *plchan,
1369 	enum dma_slave_buswidth addr_width, u32 maxburst)
1370 {
1371 	u32 width, burst, cctl = 0;
1372 
1373 	width = pl08x_width(addr_width);
1374 	if (width == ~0)
1375 		return ~0;
1376 
1377 	cctl |= width << PL080_CONTROL_SWIDTH_SHIFT;
1378 	cctl |= width << PL080_CONTROL_DWIDTH_SHIFT;
1379 
1380 	/*
1381 	 * If this channel will only request single transfers, set this
1382 	 * down to ONE element.  Also select one element if no maxburst
1383 	 * is specified.
1384 	 */
1385 	if (plchan->cd->single)
1386 		maxburst = 1;
1387 
1388 	burst = pl08x_burst(maxburst);
1389 	cctl |= burst << PL080_CONTROL_SB_SIZE_SHIFT;
1390 	cctl |= burst << PL080_CONTROL_DB_SIZE_SHIFT;
1391 
1392 	return pl08x_cctl(cctl);
1393 }
1394 
1395 /*
1396  * Slave transactions callback to the slave device to allow
1397  * synchronization of slave DMA signals with the DMAC enable
1398  */
1399 static void pl08x_issue_pending(struct dma_chan *chan)
1400 {
1401 	struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
1402 	unsigned long flags;
1403 
1404 	spin_lock_irqsave(&plchan->vc.lock, flags);
1405 	if (vchan_issue_pending(&plchan->vc)) {
1406 		if (!plchan->phychan && plchan->state != PL08X_CHAN_WAITING)
1407 			pl08x_phy_alloc_and_start(plchan);
1408 	}
1409 	spin_unlock_irqrestore(&plchan->vc.lock, flags);
1410 }
1411 
1412 static struct pl08x_txd *pl08x_get_txd(struct pl08x_dma_chan *plchan)
1413 {
1414 	struct pl08x_txd *txd = kzalloc(sizeof(*txd), GFP_NOWAIT);
1415 
1416 	if (txd) {
1417 		INIT_LIST_HEAD(&txd->dsg_list);
1418 
1419 		/* Always enable error and terminal interrupts */
1420 		txd->ccfg = PL080_CONFIG_ERR_IRQ_MASK |
1421 			    PL080_CONFIG_TC_IRQ_MASK;
1422 	}
1423 	return txd;
1424 }
1425 
1426 /*
1427  * Initialize a descriptor to be used by memcpy submit
1428  */
1429 static struct dma_async_tx_descriptor *pl08x_prep_dma_memcpy(
1430 		struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
1431 		size_t len, unsigned long flags)
1432 {
1433 	struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
1434 	struct pl08x_driver_data *pl08x = plchan->host;
1435 	struct pl08x_txd *txd;
1436 	struct pl08x_sg *dsg;
1437 	int ret;
1438 
1439 	txd = pl08x_get_txd(plchan);
1440 	if (!txd) {
1441 		dev_err(&pl08x->adev->dev,
1442 			"%s no memory for descriptor\n", __func__);
1443 		return NULL;
1444 	}
1445 
1446 	dsg = kzalloc(sizeof(struct pl08x_sg), GFP_NOWAIT);
1447 	if (!dsg) {
1448 		pl08x_free_txd(pl08x, txd);
1449 		dev_err(&pl08x->adev->dev, "%s no memory for pl080 sg\n",
1450 				__func__);
1451 		return NULL;
1452 	}
1453 	list_add_tail(&dsg->node, &txd->dsg_list);
1454 
1455 	dsg->src_addr = src;
1456 	dsg->dst_addr = dest;
1457 	dsg->len = len;
1458 
1459 	/* Set platform data for m2m */
1460 	txd->ccfg |= PL080_FLOW_MEM2MEM << PL080_CONFIG_FLOW_CONTROL_SHIFT;
1461 	txd->cctl = pl08x->pd->memcpy_channel.cctl_memcpy &
1462 			~(PL080_CONTROL_DST_AHB2 | PL080_CONTROL_SRC_AHB2);
1463 
1464 	/* Both to be incremented or the code will break */
1465 	txd->cctl |= PL080_CONTROL_SRC_INCR | PL080_CONTROL_DST_INCR;
1466 
1467 	if (pl08x->vd->dualmaster)
1468 		txd->cctl |= pl08x_select_bus(pl08x->mem_buses,
1469 					      pl08x->mem_buses);
1470 
1471 	ret = pl08x_fill_llis_for_desc(plchan->host, txd);
1472 	if (!ret) {
1473 		pl08x_free_txd(pl08x, txd);
1474 		return NULL;
1475 	}
1476 
1477 	return vchan_tx_prep(&plchan->vc, &txd->vd, flags);
1478 }
1479 
1480 static struct pl08x_txd *pl08x_init_txd(
1481 		struct dma_chan *chan,
1482 		enum dma_transfer_direction direction,
1483 		dma_addr_t *slave_addr)
1484 {
1485 	struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
1486 	struct pl08x_driver_data *pl08x = plchan->host;
1487 	struct pl08x_txd *txd;
1488 	enum dma_slave_buswidth addr_width;
1489 	int ret, tmp;
1490 	u8 src_buses, dst_buses;
1491 	u32 maxburst, cctl;
1492 
1493 	txd = pl08x_get_txd(plchan);
1494 	if (!txd) {
1495 		dev_err(&pl08x->adev->dev, "%s no txd\n", __func__);
1496 		return NULL;
1497 	}
1498 
1499 	/*
1500 	 * Set up addresses, the PrimeCell configured address
1501 	 * will take precedence since this may configure the
1502 	 * channel target address dynamically at runtime.
1503 	 */
1504 	if (direction == DMA_MEM_TO_DEV) {
1505 		cctl = PL080_CONTROL_SRC_INCR;
1506 		*slave_addr = plchan->cfg.dst_addr;
1507 		addr_width = plchan->cfg.dst_addr_width;
1508 		maxburst = plchan->cfg.dst_maxburst;
1509 		src_buses = pl08x->mem_buses;
1510 		dst_buses = plchan->cd->periph_buses;
1511 	} else if (direction == DMA_DEV_TO_MEM) {
1512 		cctl = PL080_CONTROL_DST_INCR;
1513 		*slave_addr = plchan->cfg.src_addr;
1514 		addr_width = plchan->cfg.src_addr_width;
1515 		maxburst = plchan->cfg.src_maxburst;
1516 		src_buses = plchan->cd->periph_buses;
1517 		dst_buses = pl08x->mem_buses;
1518 	} else {
1519 		pl08x_free_txd(pl08x, txd);
1520 		dev_err(&pl08x->adev->dev,
1521 			"%s direction unsupported\n", __func__);
1522 		return NULL;
1523 	}
1524 
1525 	cctl |= pl08x_get_cctl(plchan, addr_width, maxburst);
1526 	if (cctl == ~0) {
1527 		pl08x_free_txd(pl08x, txd);
1528 		dev_err(&pl08x->adev->dev,
1529 			"DMA slave configuration botched?\n");
1530 		return NULL;
1531 	}
1532 
1533 	txd->cctl = cctl | pl08x_select_bus(src_buses, dst_buses);
1534 
1535 	if (plchan->cfg.device_fc)
1536 		tmp = (direction == DMA_MEM_TO_DEV) ? PL080_FLOW_MEM2PER_PER :
1537 			PL080_FLOW_PER2MEM_PER;
1538 	else
1539 		tmp = (direction == DMA_MEM_TO_DEV) ? PL080_FLOW_MEM2PER :
1540 			PL080_FLOW_PER2MEM;
1541 
1542 	txd->ccfg |= tmp << PL080_CONFIG_FLOW_CONTROL_SHIFT;
1543 
1544 	ret = pl08x_request_mux(plchan);
1545 	if (ret < 0) {
1546 		pl08x_free_txd(pl08x, txd);
1547 		dev_dbg(&pl08x->adev->dev,
1548 			"unable to mux for transfer on %s due to platform restrictions\n",
1549 			plchan->name);
1550 		return NULL;
1551 	}
1552 
1553 	dev_dbg(&pl08x->adev->dev, "allocated DMA request signal %d for xfer on %s\n",
1554 		 plchan->signal, plchan->name);
1555 
1556 	/* Assign the flow control signal to this channel */
1557 	if (direction == DMA_MEM_TO_DEV)
1558 		txd->ccfg |= plchan->signal << PL080_CONFIG_DST_SEL_SHIFT;
1559 	else
1560 		txd->ccfg |= plchan->signal << PL080_CONFIG_SRC_SEL_SHIFT;
1561 
1562 	return txd;
1563 }
1564 
1565 static int pl08x_tx_add_sg(struct pl08x_txd *txd,
1566 			   enum dma_transfer_direction direction,
1567 			   dma_addr_t slave_addr,
1568 			   dma_addr_t buf_addr,
1569 			   unsigned int len)
1570 {
1571 	struct pl08x_sg *dsg;
1572 
1573 	dsg = kzalloc(sizeof(struct pl08x_sg), GFP_NOWAIT);
1574 	if (!dsg)
1575 		return -ENOMEM;
1576 
1577 	list_add_tail(&dsg->node, &txd->dsg_list);
1578 
1579 	dsg->len = len;
1580 	if (direction == DMA_MEM_TO_DEV) {
1581 		dsg->src_addr = buf_addr;
1582 		dsg->dst_addr = slave_addr;
1583 	} else {
1584 		dsg->src_addr = slave_addr;
1585 		dsg->dst_addr = buf_addr;
1586 	}
1587 
1588 	return 0;
1589 }
1590 
1591 static struct dma_async_tx_descriptor *pl08x_prep_slave_sg(
1592 		struct dma_chan *chan, struct scatterlist *sgl,
1593 		unsigned int sg_len, enum dma_transfer_direction direction,
1594 		unsigned long flags, void *context)
1595 {
1596 	struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
1597 	struct pl08x_driver_data *pl08x = plchan->host;
1598 	struct pl08x_txd *txd;
1599 	struct scatterlist *sg;
1600 	int ret, tmp;
1601 	dma_addr_t slave_addr;
1602 
1603 	dev_dbg(&pl08x->adev->dev, "%s prepare transaction of %d bytes from %s\n",
1604 			__func__, sg_dma_len(sgl), plchan->name);
1605 
1606 	txd = pl08x_init_txd(chan, direction, &slave_addr);
1607 	if (!txd)
1608 		return NULL;
1609 
1610 	for_each_sg(sgl, sg, sg_len, tmp) {
1611 		ret = pl08x_tx_add_sg(txd, direction, slave_addr,
1612 				      sg_dma_address(sg),
1613 				      sg_dma_len(sg));
1614 		if (ret) {
1615 			pl08x_release_mux(plchan);
1616 			pl08x_free_txd(pl08x, txd);
1617 			dev_err(&pl08x->adev->dev, "%s no mem for pl080 sg\n",
1618 					__func__);
1619 			return NULL;
1620 		}
1621 	}
1622 
1623 	ret = pl08x_fill_llis_for_desc(plchan->host, txd);
1624 	if (!ret) {
1625 		pl08x_release_mux(plchan);
1626 		pl08x_free_txd(pl08x, txd);
1627 		return NULL;
1628 	}
1629 
1630 	return vchan_tx_prep(&plchan->vc, &txd->vd, flags);
1631 }
1632 
1633 static struct dma_async_tx_descriptor *pl08x_prep_dma_cyclic(
1634 		struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
1635 		size_t period_len, enum dma_transfer_direction direction,
1636 		unsigned long flags)
1637 {
1638 	struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
1639 	struct pl08x_driver_data *pl08x = plchan->host;
1640 	struct pl08x_txd *txd;
1641 	int ret, tmp;
1642 	dma_addr_t slave_addr;
1643 
1644 	dev_dbg(&pl08x->adev->dev,
1645 		"%s prepare cyclic transaction of %zd/%zd bytes %s %s\n",
1646 		__func__, period_len, buf_len,
1647 		direction == DMA_MEM_TO_DEV ? "to" : "from",
1648 		plchan->name);
1649 
1650 	txd = pl08x_init_txd(chan, direction, &slave_addr);
1651 	if (!txd)
1652 		return NULL;
1653 
1654 	txd->cyclic = true;
1655 	txd->cctl |= PL080_CONTROL_TC_IRQ_EN;
1656 	for (tmp = 0; tmp < buf_len; tmp += period_len) {
1657 		ret = pl08x_tx_add_sg(txd, direction, slave_addr,
1658 				      buf_addr + tmp, period_len);
1659 		if (ret) {
1660 			pl08x_release_mux(plchan);
1661 			pl08x_free_txd(pl08x, txd);
1662 			return NULL;
1663 		}
1664 	}
1665 
1666 	ret = pl08x_fill_llis_for_desc(plchan->host, txd);
1667 	if (!ret) {
1668 		pl08x_release_mux(plchan);
1669 		pl08x_free_txd(pl08x, txd);
1670 		return NULL;
1671 	}
1672 
1673 	return vchan_tx_prep(&plchan->vc, &txd->vd, flags);
1674 }
1675 
1676 static int pl08x_config(struct dma_chan *chan,
1677 			struct dma_slave_config *config)
1678 {
1679 	struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
1680 	struct pl08x_driver_data *pl08x = plchan->host;
1681 
1682 	if (!plchan->slave)
1683 		return -EINVAL;
1684 
1685 	/* Reject definitely invalid configurations */
1686 	if (config->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES ||
1687 	    config->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
1688 		return -EINVAL;
1689 
1690 	if (config->device_fc && pl08x->vd->pl080s) {
1691 		dev_err(&pl08x->adev->dev,
1692 			"%s: PL080S does not support peripheral flow control\n",
1693 			__func__);
1694 		return -EINVAL;
1695 	}
1696 
1697 	plchan->cfg = *config;
1698 
1699 	return 0;
1700 }
1701 
1702 static int pl08x_terminate_all(struct dma_chan *chan)
1703 {
1704 	struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
1705 	struct pl08x_driver_data *pl08x = plchan->host;
1706 	unsigned long flags;
1707 
1708 	spin_lock_irqsave(&plchan->vc.lock, flags);
1709 	if (!plchan->phychan && !plchan->at) {
1710 		spin_unlock_irqrestore(&plchan->vc.lock, flags);
1711 		return 0;
1712 	}
1713 
1714 	plchan->state = PL08X_CHAN_IDLE;
1715 
1716 	if (plchan->phychan) {
1717 		/*
1718 		 * Mark physical channel as free and free any slave
1719 		 * signal
1720 		 */
1721 		pl08x_phy_free(plchan);
1722 	}
1723 	/* Dequeue jobs and free LLIs */
1724 	if (plchan->at) {
1725 		pl08x_desc_free(&plchan->at->vd);
1726 		plchan->at = NULL;
1727 	}
1728 	/* Dequeue jobs not yet fired as well */
1729 	pl08x_free_txd_list(pl08x, plchan);
1730 
1731 	spin_unlock_irqrestore(&plchan->vc.lock, flags);
1732 
1733 	return 0;
1734 }
1735 
1736 static int pl08x_pause(struct dma_chan *chan)
1737 {
1738 	struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
1739 	unsigned long flags;
1740 
1741 	/*
1742 	 * Anything succeeds on channels with no physical allocation and
1743 	 * no queued transfers.
1744 	 */
1745 	spin_lock_irqsave(&plchan->vc.lock, flags);
1746 	if (!plchan->phychan && !plchan->at) {
1747 		spin_unlock_irqrestore(&plchan->vc.lock, flags);
1748 		return 0;
1749 	}
1750 
1751 	pl08x_pause_phy_chan(plchan->phychan);
1752 	plchan->state = PL08X_CHAN_PAUSED;
1753 
1754 	spin_unlock_irqrestore(&plchan->vc.lock, flags);
1755 
1756 	return 0;
1757 }
1758 
1759 static int pl08x_resume(struct dma_chan *chan)
1760 {
1761 	struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
1762 	unsigned long flags;
1763 
1764 	/*
1765 	 * Anything succeeds on channels with no physical allocation and
1766 	 * no queued transfers.
1767 	 */
1768 	spin_lock_irqsave(&plchan->vc.lock, flags);
1769 	if (!plchan->phychan && !plchan->at) {
1770 		spin_unlock_irqrestore(&plchan->vc.lock, flags);
1771 		return 0;
1772 	}
1773 
1774 	pl08x_resume_phy_chan(plchan->phychan);
1775 	plchan->state = PL08X_CHAN_RUNNING;
1776 
1777 	spin_unlock_irqrestore(&plchan->vc.lock, flags);
1778 
1779 	return 0;
1780 }
1781 
1782 bool pl08x_filter_id(struct dma_chan *chan, void *chan_id)
1783 {
1784 	struct pl08x_dma_chan *plchan;
1785 	char *name = chan_id;
1786 
1787 	/* Reject channels for devices not bound to this driver */
1788 	if (chan->device->dev->driver != &pl08x_amba_driver.drv)
1789 		return false;
1790 
1791 	plchan = to_pl08x_chan(chan);
1792 
1793 	/* Check that the channel is not taken! */
1794 	if (!strcmp(plchan->name, name))
1795 		return true;
1796 
1797 	return false;
1798 }
1799 EXPORT_SYMBOL_GPL(pl08x_filter_id);
1800 
1801 /*
1802  * Just check that the device is there and active
1803  * TODO: turn this bit on/off depending on the number of physical channels
1804  * actually used, if it is zero... well shut it off. That will save some
1805  * power. Cut the clock at the same time.
1806  */
1807 static void pl08x_ensure_on(struct pl08x_driver_data *pl08x)
1808 {
1809 	/* The Nomadik variant does not have the config register */
1810 	if (pl08x->vd->nomadik)
1811 		return;
1812 	writel(PL080_CONFIG_ENABLE, pl08x->base + PL080_CONFIG);
1813 }
1814 
1815 static irqreturn_t pl08x_irq(int irq, void *dev)
1816 {
1817 	struct pl08x_driver_data *pl08x = dev;
1818 	u32 mask = 0, err, tc, i;
1819 
1820 	/* check & clear - ERR & TC interrupts */
1821 	err = readl(pl08x->base + PL080_ERR_STATUS);
1822 	if (err) {
1823 		dev_err(&pl08x->adev->dev, "%s error interrupt, register value 0x%08x\n",
1824 			__func__, err);
1825 		writel(err, pl08x->base + PL080_ERR_CLEAR);
1826 	}
1827 	tc = readl(pl08x->base + PL080_TC_STATUS);
1828 	if (tc)
1829 		writel(tc, pl08x->base + PL080_TC_CLEAR);
1830 
1831 	if (!err && !tc)
1832 		return IRQ_NONE;
1833 
1834 	for (i = 0; i < pl08x->vd->channels; i++) {
1835 		if (((1 << i) & err) || ((1 << i) & tc)) {
1836 			/* Locate physical channel */
1837 			struct pl08x_phy_chan *phychan = &pl08x->phy_chans[i];
1838 			struct pl08x_dma_chan *plchan = phychan->serving;
1839 			struct pl08x_txd *tx;
1840 
1841 			if (!plchan) {
1842 				dev_err(&pl08x->adev->dev,
1843 					"%s Error TC interrupt on unused channel: 0x%08x\n",
1844 					__func__, i);
1845 				continue;
1846 			}
1847 
1848 			spin_lock(&plchan->vc.lock);
1849 			tx = plchan->at;
1850 			if (tx && tx->cyclic) {
1851 				vchan_cyclic_callback(&tx->vd);
1852 			} else if (tx) {
1853 				plchan->at = NULL;
1854 				/*
1855 				 * This descriptor is done, release its mux
1856 				 * reservation.
1857 				 */
1858 				pl08x_release_mux(plchan);
1859 				tx->done = true;
1860 				vchan_cookie_complete(&tx->vd);
1861 
1862 				/*
1863 				 * And start the next descriptor (if any),
1864 				 * otherwise free this channel.
1865 				 */
1866 				if (vchan_next_desc(&plchan->vc))
1867 					pl08x_start_next_txd(plchan);
1868 				else
1869 					pl08x_phy_free(plchan);
1870 			}
1871 			spin_unlock(&plchan->vc.lock);
1872 
1873 			mask |= (1 << i);
1874 		}
1875 	}
1876 
1877 	return mask ? IRQ_HANDLED : IRQ_NONE;
1878 }
1879 
1880 static void pl08x_dma_slave_init(struct pl08x_dma_chan *chan)
1881 {
1882 	chan->slave = true;
1883 	chan->name = chan->cd->bus_id;
1884 	chan->cfg.src_addr = chan->cd->addr;
1885 	chan->cfg.dst_addr = chan->cd->addr;
1886 }
1887 
1888 /*
1889  * Initialise the DMAC memcpy/slave channels.
1890  * Make a local wrapper to hold required data
1891  */
1892 static int pl08x_dma_init_virtual_channels(struct pl08x_driver_data *pl08x,
1893 		struct dma_device *dmadev, unsigned int channels, bool slave)
1894 {
1895 	struct pl08x_dma_chan *chan;
1896 	int i;
1897 
1898 	INIT_LIST_HEAD(&dmadev->channels);
1899 
1900 	/*
1901 	 * Register as many many memcpy as we have physical channels,
1902 	 * we won't always be able to use all but the code will have
1903 	 * to cope with that situation.
1904 	 */
1905 	for (i = 0; i < channels; i++) {
1906 		chan = kzalloc(sizeof(*chan), GFP_KERNEL);
1907 		if (!chan) {
1908 			dev_err(&pl08x->adev->dev,
1909 				"%s no memory for channel\n", __func__);
1910 			return -ENOMEM;
1911 		}
1912 
1913 		chan->host = pl08x;
1914 		chan->state = PL08X_CHAN_IDLE;
1915 		chan->signal = -1;
1916 
1917 		if (slave) {
1918 			chan->cd = &pl08x->pd->slave_channels[i];
1919 			pl08x_dma_slave_init(chan);
1920 		} else {
1921 			chan->cd = &pl08x->pd->memcpy_channel;
1922 			chan->name = kasprintf(GFP_KERNEL, "memcpy%d", i);
1923 			if (!chan->name) {
1924 				kfree(chan);
1925 				return -ENOMEM;
1926 			}
1927 		}
1928 		dev_dbg(&pl08x->adev->dev,
1929 			 "initialize virtual channel \"%s\"\n",
1930 			 chan->name);
1931 
1932 		chan->vc.desc_free = pl08x_desc_free;
1933 		vchan_init(&chan->vc, dmadev);
1934 	}
1935 	dev_info(&pl08x->adev->dev, "initialized %d virtual %s channels\n",
1936 		 i, slave ? "slave" : "memcpy");
1937 	return i;
1938 }
1939 
1940 static void pl08x_free_virtual_channels(struct dma_device *dmadev)
1941 {
1942 	struct pl08x_dma_chan *chan = NULL;
1943 	struct pl08x_dma_chan *next;
1944 
1945 	list_for_each_entry_safe(chan,
1946 				 next, &dmadev->channels, vc.chan.device_node) {
1947 		list_del(&chan->vc.chan.device_node);
1948 		kfree(chan);
1949 	}
1950 }
1951 
1952 #ifdef CONFIG_DEBUG_FS
1953 static const char *pl08x_state_str(enum pl08x_dma_chan_state state)
1954 {
1955 	switch (state) {
1956 	case PL08X_CHAN_IDLE:
1957 		return "idle";
1958 	case PL08X_CHAN_RUNNING:
1959 		return "running";
1960 	case PL08X_CHAN_PAUSED:
1961 		return "paused";
1962 	case PL08X_CHAN_WAITING:
1963 		return "waiting";
1964 	default:
1965 		break;
1966 	}
1967 	return "UNKNOWN STATE";
1968 }
1969 
1970 static int pl08x_debugfs_show(struct seq_file *s, void *data)
1971 {
1972 	struct pl08x_driver_data *pl08x = s->private;
1973 	struct pl08x_dma_chan *chan;
1974 	struct pl08x_phy_chan *ch;
1975 	unsigned long flags;
1976 	int i;
1977 
1978 	seq_printf(s, "PL08x physical channels:\n");
1979 	seq_printf(s, "CHANNEL:\tUSER:\n");
1980 	seq_printf(s, "--------\t-----\n");
1981 	for (i = 0; i < pl08x->vd->channels; i++) {
1982 		struct pl08x_dma_chan *virt_chan;
1983 
1984 		ch = &pl08x->phy_chans[i];
1985 
1986 		spin_lock_irqsave(&ch->lock, flags);
1987 		virt_chan = ch->serving;
1988 
1989 		seq_printf(s, "%d\t\t%s%s\n",
1990 			   ch->id,
1991 			   virt_chan ? virt_chan->name : "(none)",
1992 			   ch->locked ? " LOCKED" : "");
1993 
1994 		spin_unlock_irqrestore(&ch->lock, flags);
1995 	}
1996 
1997 	seq_printf(s, "\nPL08x virtual memcpy channels:\n");
1998 	seq_printf(s, "CHANNEL:\tSTATE:\n");
1999 	seq_printf(s, "--------\t------\n");
2000 	list_for_each_entry(chan, &pl08x->memcpy.channels, vc.chan.device_node) {
2001 		seq_printf(s, "%s\t\t%s\n", chan->name,
2002 			   pl08x_state_str(chan->state));
2003 	}
2004 
2005 	seq_printf(s, "\nPL08x virtual slave channels:\n");
2006 	seq_printf(s, "CHANNEL:\tSTATE:\n");
2007 	seq_printf(s, "--------\t------\n");
2008 	list_for_each_entry(chan, &pl08x->slave.channels, vc.chan.device_node) {
2009 		seq_printf(s, "%s\t\t%s\n", chan->name,
2010 			   pl08x_state_str(chan->state));
2011 	}
2012 
2013 	return 0;
2014 }
2015 
2016 static int pl08x_debugfs_open(struct inode *inode, struct file *file)
2017 {
2018 	return single_open(file, pl08x_debugfs_show, inode->i_private);
2019 }
2020 
2021 static const struct file_operations pl08x_debugfs_operations = {
2022 	.open		= pl08x_debugfs_open,
2023 	.read		= seq_read,
2024 	.llseek		= seq_lseek,
2025 	.release	= single_release,
2026 };
2027 
2028 static void init_pl08x_debugfs(struct pl08x_driver_data *pl08x)
2029 {
2030 	/* Expose a simple debugfs interface to view all clocks */
2031 	(void) debugfs_create_file(dev_name(&pl08x->adev->dev),
2032 			S_IFREG | S_IRUGO, NULL, pl08x,
2033 			&pl08x_debugfs_operations);
2034 }
2035 
2036 #else
2037 static inline void init_pl08x_debugfs(struct pl08x_driver_data *pl08x)
2038 {
2039 }
2040 #endif
2041 
2042 static int pl08x_probe(struct amba_device *adev, const struct amba_id *id)
2043 {
2044 	struct pl08x_driver_data *pl08x;
2045 	const struct vendor_data *vd = id->data;
2046 	u32 tsfr_size;
2047 	int ret = 0;
2048 	int i;
2049 
2050 	ret = amba_request_regions(adev, NULL);
2051 	if (ret)
2052 		return ret;
2053 
2054 	/* Ensure that we can do DMA */
2055 	ret = dma_set_mask_and_coherent(&adev->dev, DMA_BIT_MASK(32));
2056 	if (ret)
2057 		goto out_no_pl08x;
2058 
2059 	/* Create the driver state holder */
2060 	pl08x = kzalloc(sizeof(*pl08x), GFP_KERNEL);
2061 	if (!pl08x) {
2062 		ret = -ENOMEM;
2063 		goto out_no_pl08x;
2064 	}
2065 
2066 	/* Initialize memcpy engine */
2067 	dma_cap_set(DMA_MEMCPY, pl08x->memcpy.cap_mask);
2068 	pl08x->memcpy.dev = &adev->dev;
2069 	pl08x->memcpy.device_alloc_chan_resources = pl08x_alloc_chan_resources;
2070 	pl08x->memcpy.device_free_chan_resources = pl08x_free_chan_resources;
2071 	pl08x->memcpy.device_prep_dma_memcpy = pl08x_prep_dma_memcpy;
2072 	pl08x->memcpy.device_prep_dma_interrupt = pl08x_prep_dma_interrupt;
2073 	pl08x->memcpy.device_tx_status = pl08x_dma_tx_status;
2074 	pl08x->memcpy.device_issue_pending = pl08x_issue_pending;
2075 	pl08x->memcpy.device_config = pl08x_config;
2076 	pl08x->memcpy.device_pause = pl08x_pause;
2077 	pl08x->memcpy.device_resume = pl08x_resume;
2078 	pl08x->memcpy.device_terminate_all = pl08x_terminate_all;
2079 	pl08x->memcpy.src_addr_widths = PL80X_DMA_BUSWIDTHS;
2080 	pl08x->memcpy.dst_addr_widths = PL80X_DMA_BUSWIDTHS;
2081 	pl08x->memcpy.directions = BIT(DMA_MEM_TO_MEM);
2082 	pl08x->memcpy.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
2083 
2084 	/* Initialize slave engine */
2085 	dma_cap_set(DMA_SLAVE, pl08x->slave.cap_mask);
2086 	dma_cap_set(DMA_CYCLIC, pl08x->slave.cap_mask);
2087 	pl08x->slave.dev = &adev->dev;
2088 	pl08x->slave.device_alloc_chan_resources = pl08x_alloc_chan_resources;
2089 	pl08x->slave.device_free_chan_resources = pl08x_free_chan_resources;
2090 	pl08x->slave.device_prep_dma_interrupt = pl08x_prep_dma_interrupt;
2091 	pl08x->slave.device_tx_status = pl08x_dma_tx_status;
2092 	pl08x->slave.device_issue_pending = pl08x_issue_pending;
2093 	pl08x->slave.device_prep_slave_sg = pl08x_prep_slave_sg;
2094 	pl08x->slave.device_prep_dma_cyclic = pl08x_prep_dma_cyclic;
2095 	pl08x->slave.device_config = pl08x_config;
2096 	pl08x->slave.device_pause = pl08x_pause;
2097 	pl08x->slave.device_resume = pl08x_resume;
2098 	pl08x->slave.device_terminate_all = pl08x_terminate_all;
2099 	pl08x->slave.src_addr_widths = PL80X_DMA_BUSWIDTHS;
2100 	pl08x->slave.dst_addr_widths = PL80X_DMA_BUSWIDTHS;
2101 	pl08x->slave.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
2102 	pl08x->slave.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
2103 
2104 	/* Get the platform data */
2105 	pl08x->pd = dev_get_platdata(&adev->dev);
2106 	if (!pl08x->pd) {
2107 		dev_err(&adev->dev, "no platform data supplied\n");
2108 		ret = -EINVAL;
2109 		goto out_no_platdata;
2110 	}
2111 
2112 	/* Assign useful pointers to the driver state */
2113 	pl08x->adev = adev;
2114 	pl08x->vd = vd;
2115 
2116 	/* By default, AHB1 only.  If dualmaster, from platform */
2117 	pl08x->lli_buses = PL08X_AHB1;
2118 	pl08x->mem_buses = PL08X_AHB1;
2119 	if (pl08x->vd->dualmaster) {
2120 		pl08x->lli_buses = pl08x->pd->lli_buses;
2121 		pl08x->mem_buses = pl08x->pd->mem_buses;
2122 	}
2123 
2124 	if (vd->pl080s)
2125 		pl08x->lli_words = PL080S_LLI_WORDS;
2126 	else
2127 		pl08x->lli_words = PL080_LLI_WORDS;
2128 	tsfr_size = MAX_NUM_TSFR_LLIS * pl08x->lli_words * sizeof(u32);
2129 
2130 	/* A DMA memory pool for LLIs, align on 1-byte boundary */
2131 	pl08x->pool = dma_pool_create(DRIVER_NAME, &pl08x->adev->dev,
2132 						tsfr_size, PL08X_ALIGN, 0);
2133 	if (!pl08x->pool) {
2134 		ret = -ENOMEM;
2135 		goto out_no_lli_pool;
2136 	}
2137 
2138 	pl08x->base = ioremap(adev->res.start, resource_size(&adev->res));
2139 	if (!pl08x->base) {
2140 		ret = -ENOMEM;
2141 		goto out_no_ioremap;
2142 	}
2143 
2144 	/* Turn on the PL08x */
2145 	pl08x_ensure_on(pl08x);
2146 
2147 	/* Attach the interrupt handler */
2148 	writel(0x000000FF, pl08x->base + PL080_ERR_CLEAR);
2149 	writel(0x000000FF, pl08x->base + PL080_TC_CLEAR);
2150 
2151 	ret = request_irq(adev->irq[0], pl08x_irq, 0, DRIVER_NAME, pl08x);
2152 	if (ret) {
2153 		dev_err(&adev->dev, "%s failed to request interrupt %d\n",
2154 			__func__, adev->irq[0]);
2155 		goto out_no_irq;
2156 	}
2157 
2158 	/* Initialize physical channels */
2159 	pl08x->phy_chans = kzalloc((vd->channels * sizeof(*pl08x->phy_chans)),
2160 			GFP_KERNEL);
2161 	if (!pl08x->phy_chans) {
2162 		dev_err(&adev->dev, "%s failed to allocate "
2163 			"physical channel holders\n",
2164 			__func__);
2165 		ret = -ENOMEM;
2166 		goto out_no_phychans;
2167 	}
2168 
2169 	for (i = 0; i < vd->channels; i++) {
2170 		struct pl08x_phy_chan *ch = &pl08x->phy_chans[i];
2171 
2172 		ch->id = i;
2173 		ch->base = pl08x->base + PL080_Cx_BASE(i);
2174 		ch->reg_config = ch->base + vd->config_offset;
2175 		spin_lock_init(&ch->lock);
2176 
2177 		/*
2178 		 * Nomadik variants can have channels that are locked
2179 		 * down for the secure world only. Lock up these channels
2180 		 * by perpetually serving a dummy virtual channel.
2181 		 */
2182 		if (vd->nomadik) {
2183 			u32 val;
2184 
2185 			val = readl(ch->reg_config);
2186 			if (val & (PL080N_CONFIG_ITPROT | PL080N_CONFIG_SECPROT)) {
2187 				dev_info(&adev->dev, "physical channel %d reserved for secure access only\n", i);
2188 				ch->locked = true;
2189 			}
2190 		}
2191 
2192 		dev_dbg(&adev->dev, "physical channel %d is %s\n",
2193 			i, pl08x_phy_channel_busy(ch) ? "BUSY" : "FREE");
2194 	}
2195 
2196 	/* Register as many memcpy channels as there are physical channels */
2197 	ret = pl08x_dma_init_virtual_channels(pl08x, &pl08x->memcpy,
2198 					      pl08x->vd->channels, false);
2199 	if (ret <= 0) {
2200 		dev_warn(&pl08x->adev->dev,
2201 			 "%s failed to enumerate memcpy channels - %d\n",
2202 			 __func__, ret);
2203 		goto out_no_memcpy;
2204 	}
2205 
2206 	/* Register slave channels */
2207 	ret = pl08x_dma_init_virtual_channels(pl08x, &pl08x->slave,
2208 			pl08x->pd->num_slave_channels, true);
2209 	if (ret < 0) {
2210 		dev_warn(&pl08x->adev->dev,
2211 			"%s failed to enumerate slave channels - %d\n",
2212 				__func__, ret);
2213 		goto out_no_slave;
2214 	}
2215 
2216 	ret = dma_async_device_register(&pl08x->memcpy);
2217 	if (ret) {
2218 		dev_warn(&pl08x->adev->dev,
2219 			"%s failed to register memcpy as an async device - %d\n",
2220 			__func__, ret);
2221 		goto out_no_memcpy_reg;
2222 	}
2223 
2224 	ret = dma_async_device_register(&pl08x->slave);
2225 	if (ret) {
2226 		dev_warn(&pl08x->adev->dev,
2227 			"%s failed to register slave as an async device - %d\n",
2228 			__func__, ret);
2229 		goto out_no_slave_reg;
2230 	}
2231 
2232 	amba_set_drvdata(adev, pl08x);
2233 	init_pl08x_debugfs(pl08x);
2234 	dev_info(&pl08x->adev->dev, "DMA: PL%03x%s rev%u at 0x%08llx irq %d\n",
2235 		 amba_part(adev), pl08x->vd->pl080s ? "s" : "", amba_rev(adev),
2236 		 (unsigned long long)adev->res.start, adev->irq[0]);
2237 
2238 	return 0;
2239 
2240 out_no_slave_reg:
2241 	dma_async_device_unregister(&pl08x->memcpy);
2242 out_no_memcpy_reg:
2243 	pl08x_free_virtual_channels(&pl08x->slave);
2244 out_no_slave:
2245 	pl08x_free_virtual_channels(&pl08x->memcpy);
2246 out_no_memcpy:
2247 	kfree(pl08x->phy_chans);
2248 out_no_phychans:
2249 	free_irq(adev->irq[0], pl08x);
2250 out_no_irq:
2251 	iounmap(pl08x->base);
2252 out_no_ioremap:
2253 	dma_pool_destroy(pl08x->pool);
2254 out_no_lli_pool:
2255 out_no_platdata:
2256 	kfree(pl08x);
2257 out_no_pl08x:
2258 	amba_release_regions(adev);
2259 	return ret;
2260 }
2261 
2262 /* PL080 has 8 channels and the PL080 have just 2 */
2263 static struct vendor_data vendor_pl080 = {
2264 	.config_offset = PL080_CH_CONFIG,
2265 	.channels = 8,
2266 	.dualmaster = true,
2267 	.max_transfer_size = PL080_CONTROL_TRANSFER_SIZE_MASK,
2268 };
2269 
2270 static struct vendor_data vendor_nomadik = {
2271 	.config_offset = PL080_CH_CONFIG,
2272 	.channels = 8,
2273 	.dualmaster = true,
2274 	.nomadik = true,
2275 	.max_transfer_size = PL080_CONTROL_TRANSFER_SIZE_MASK,
2276 };
2277 
2278 static struct vendor_data vendor_pl080s = {
2279 	.config_offset = PL080S_CH_CONFIG,
2280 	.channels = 8,
2281 	.pl080s = true,
2282 	.max_transfer_size = PL080S_CONTROL_TRANSFER_SIZE_MASK,
2283 };
2284 
2285 static struct vendor_data vendor_pl081 = {
2286 	.config_offset = PL080_CH_CONFIG,
2287 	.channels = 2,
2288 	.dualmaster = false,
2289 	.max_transfer_size = PL080_CONTROL_TRANSFER_SIZE_MASK,
2290 };
2291 
2292 static struct amba_id pl08x_ids[] = {
2293 	/* Samsung PL080S variant */
2294 	{
2295 		.id	= 0x0a141080,
2296 		.mask	= 0xffffffff,
2297 		.data	= &vendor_pl080s,
2298 	},
2299 	/* PL080 */
2300 	{
2301 		.id	= 0x00041080,
2302 		.mask	= 0x000fffff,
2303 		.data	= &vendor_pl080,
2304 	},
2305 	/* PL081 */
2306 	{
2307 		.id	= 0x00041081,
2308 		.mask	= 0x000fffff,
2309 		.data	= &vendor_pl081,
2310 	},
2311 	/* Nomadik 8815 PL080 variant */
2312 	{
2313 		.id	= 0x00280080,
2314 		.mask	= 0x00ffffff,
2315 		.data	= &vendor_nomadik,
2316 	},
2317 	{ 0, 0 },
2318 };
2319 
2320 MODULE_DEVICE_TABLE(amba, pl08x_ids);
2321 
2322 static struct amba_driver pl08x_amba_driver = {
2323 	.drv.name	= DRIVER_NAME,
2324 	.id_table	= pl08x_ids,
2325 	.probe		= pl08x_probe,
2326 };
2327 
2328 static int __init pl08x_init(void)
2329 {
2330 	int retval;
2331 	retval = amba_driver_register(&pl08x_amba_driver);
2332 	if (retval)
2333 		printk(KERN_WARNING DRIVER_NAME
2334 		       "failed to register as an AMBA device (%d)\n",
2335 		       retval);
2336 	return retval;
2337 }
2338 subsys_initcall(pl08x_init);
2339