xref: /linux/drivers/dma/amba-pl08x.c (revision c0e297dc61f8d4453e07afbea1fa8d0e67cd4a34)
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  * The full GNU General Public License is in this distribution in the file
19  * called COPYING.
20  *
21  * Documentation: ARM DDI 0196G == PL080
22  * Documentation: ARM DDI 0218E == PL081
23  * Documentation: S3C6410 User's Manual == PL080S
24  *
25  * PL080 & PL081 both have 16 sets of DMA signals that can be routed to any
26  * channel.
27  *
28  * The PL080 has 8 channels available for simultaneous use, and the PL081
29  * has only two channels. So on these DMA controllers the number of channels
30  * and the number of incoming DMA signals are two totally different things.
31  * It is usually not possible to theoretically handle all physical signals,
32  * so a multiplexing scheme with possible denial of use is necessary.
33  *
34  * The PL080 has a dual bus master, PL081 has a single master.
35  *
36  * PL080S is a version modified by Samsung and used in S3C64xx SoCs.
37  * It differs in following aspects:
38  * - CH_CONFIG register at different offset,
39  * - separate CH_CONTROL2 register for transfer size,
40  * - bigger maximum transfer size,
41  * - 8-word aligned LLI, instead of 4-word, due to extra CCTL2 word,
42  * - no support for peripheral flow control.
43  *
44  * Memory to peripheral transfer may be visualized as
45  *	Get data from memory to DMAC
46  *	Until no data left
47  *		On burst request from peripheral
48  *			Destination burst from DMAC to peripheral
49  *			Clear burst request
50  *	Raise terminal count interrupt
51  *
52  * For peripherals with a FIFO:
53  * Source      burst size == half the depth of the peripheral FIFO
54  * Destination burst size == the depth of the peripheral FIFO
55  *
56  * (Bursts are irrelevant for mem to mem transfers - there are no burst
57  * signals, the DMA controller will simply facilitate its AHB master.)
58  *
59  * ASSUMES default (little) endianness for DMA transfers
60  *
61  * The PL08x has two flow control settings:
62  *  - DMAC flow control: the transfer size defines the number of transfers
63  *    which occur for the current LLI entry, and the DMAC raises TC at the
64  *    end of every LLI entry.  Observed behaviour shows the DMAC listening
65  *    to both the BREQ and SREQ signals (contrary to documented),
66  *    transferring data if either is active.  The LBREQ and LSREQ signals
67  *    are ignored.
68  *
69  *  - Peripheral flow control: the transfer size is ignored (and should be
70  *    zero).  The data is transferred from the current LLI entry, until
71  *    after the final transfer signalled by LBREQ or LSREQ.  The DMAC
72  *    will then move to the next LLI entry. Unsupported by PL080S.
73  */
74 #include <linux/amba/bus.h>
75 #include <linux/amba/pl08x.h>
76 #include <linux/debugfs.h>
77 #include <linux/delay.h>
78 #include <linux/device.h>
79 #include <linux/dmaengine.h>
80 #include <linux/dmapool.h>
81 #include <linux/dma-mapping.h>
82 #include <linux/export.h>
83 #include <linux/init.h>
84 #include <linux/interrupt.h>
85 #include <linux/module.h>
86 #include <linux/pm_runtime.h>
87 #include <linux/seq_file.h>
88 #include <linux/slab.h>
89 #include <linux/amba/pl080.h>
90 
91 #include "dmaengine.h"
92 #include "virt-dma.h"
93 
94 #define DRIVER_NAME	"pl08xdmac"
95 
96 #define PL80X_DMA_BUSWIDTHS \
97 	BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) | \
98 	BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
99 	BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
100 	BIT(DMA_SLAVE_BUSWIDTH_4_BYTES)
101 
102 static struct amba_driver pl08x_amba_driver;
103 struct pl08x_driver_data;
104 
105 /**
106  * struct vendor_data - vendor-specific config parameters for PL08x derivatives
107  * @channels: the number of channels available in this variant
108  * @dualmaster: whether this version supports dual AHB masters or not.
109  * @nomadik: whether the channels have Nomadik security extension bits
110  *	that need to be checked for permission before use and some registers are
111  *	missing
112  * @pl080s: whether this version is a PL080S, which has separate register and
113  *	LLI word for transfer size.
114  */
115 struct vendor_data {
116 	u8 config_offset;
117 	u8 channels;
118 	bool dualmaster;
119 	bool nomadik;
120 	bool pl080s;
121 	u32 max_transfer_size;
122 };
123 
124 /**
125  * struct pl08x_bus_data - information of source or destination
126  * busses for a transfer
127  * @addr: current address
128  * @maxwidth: the maximum width of a transfer on this bus
129  * @buswidth: the width of this bus in bytes: 1, 2 or 4
130  */
131 struct pl08x_bus_data {
132 	dma_addr_t addr;
133 	u8 maxwidth;
134 	u8 buswidth;
135 };
136 
137 #define IS_BUS_ALIGNED(bus) IS_ALIGNED((bus)->addr, (bus)->buswidth)
138 
139 /**
140  * struct pl08x_phy_chan - holder for the physical channels
141  * @id: physical index to this channel
142  * @lock: a lock to use when altering an instance of this struct
143  * @serving: the virtual channel currently being served by this physical
144  * channel
145  * @locked: channel unavailable for the system, e.g. dedicated to secure
146  * world
147  */
148 struct pl08x_phy_chan {
149 	unsigned int id;
150 	void __iomem *base;
151 	void __iomem *reg_config;
152 	spinlock_t lock;
153 	struct pl08x_dma_chan *serving;
154 	bool locked;
155 };
156 
157 /**
158  * struct pl08x_sg - structure containing data per sg
159  * @src_addr: src address of sg
160  * @dst_addr: dst address of sg
161  * @len: transfer len in bytes
162  * @node: node for txd's dsg_list
163  */
164 struct pl08x_sg {
165 	dma_addr_t src_addr;
166 	dma_addr_t dst_addr;
167 	size_t len;
168 	struct list_head node;
169 };
170 
171 /**
172  * struct pl08x_txd - wrapper for struct dma_async_tx_descriptor
173  * @vd: virtual DMA descriptor
174  * @dsg_list: list of children sg's
175  * @llis_bus: DMA memory address (physical) start for the LLIs
176  * @llis_va: virtual memory address start for the LLIs
177  * @cctl: control reg values for current txd
178  * @ccfg: config reg values for current txd
179  * @done: this marks completed descriptors, which should not have their
180  *   mux released.
181  * @cyclic: indicate cyclic transfers
182  */
183 struct pl08x_txd {
184 	struct virt_dma_desc vd;
185 	struct list_head dsg_list;
186 	dma_addr_t llis_bus;
187 	u32 *llis_va;
188 	/* Default cctl value for LLIs */
189 	u32 cctl;
190 	/*
191 	 * Settings to be put into the physical channel when we
192 	 * trigger this txd.  Other registers are in llis_va[0].
193 	 */
194 	u32 ccfg;
195 	bool done;
196 	bool cyclic;
197 };
198 
199 /**
200  * struct pl08x_dma_chan_state - holds the PL08x specific virtual channel
201  * states
202  * @PL08X_CHAN_IDLE: the channel is idle
203  * @PL08X_CHAN_RUNNING: the channel has allocated a physical transport
204  * channel and is running a transfer on it
205  * @PL08X_CHAN_PAUSED: the channel has allocated a physical transport
206  * channel, but the transfer is currently paused
207  * @PL08X_CHAN_WAITING: the channel is waiting for a physical transport
208  * channel to become available (only pertains to memcpy channels)
209  */
210 enum pl08x_dma_chan_state {
211 	PL08X_CHAN_IDLE,
212 	PL08X_CHAN_RUNNING,
213 	PL08X_CHAN_PAUSED,
214 	PL08X_CHAN_WAITING,
215 };
216 
217 /**
218  * struct pl08x_dma_chan - this structure wraps a DMA ENGINE channel
219  * @vc: wrappped virtual channel
220  * @phychan: the physical channel utilized by this channel, if there is one
221  * @name: name of channel
222  * @cd: channel platform data
223  * @runtime_addr: address for RX/TX according to the runtime config
224  * @at: active transaction on this channel
225  * @lock: a lock for this channel data
226  * @host: a pointer to the host (internal use)
227  * @state: whether the channel is idle, paused, running etc
228  * @slave: whether this channel is a device (slave) or for memcpy
229  * @signal: the physical DMA request signal which this channel is using
230  * @mux_use: count of descriptors using this DMA request signal setting
231  */
232 struct pl08x_dma_chan {
233 	struct virt_dma_chan vc;
234 	struct pl08x_phy_chan *phychan;
235 	const char *name;
236 	const struct pl08x_channel_data *cd;
237 	struct dma_slave_config cfg;
238 	struct pl08x_txd *at;
239 	struct pl08x_driver_data *host;
240 	enum pl08x_dma_chan_state state;
241 	bool slave;
242 	int signal;
243 	unsigned mux_use;
244 };
245 
246 /**
247  * struct pl08x_driver_data - the local state holder for the PL08x
248  * @slave: slave engine for this instance
249  * @memcpy: memcpy engine for this instance
250  * @base: virtual memory base (remapped) for the PL08x
251  * @adev: the corresponding AMBA (PrimeCell) bus entry
252  * @vd: vendor data for this PL08x variant
253  * @pd: platform data passed in from the platform/machine
254  * @phy_chans: array of data for the physical channels
255  * @pool: a pool for the LLI descriptors
256  * @lli_buses: bitmask to or in to LLI pointer selecting AHB port for LLI
257  * fetches
258  * @mem_buses: set to indicate memory transfers on AHB2.
259  * @lock: a spinlock for this struct
260  */
261 struct pl08x_driver_data {
262 	struct dma_device slave;
263 	struct dma_device memcpy;
264 	void __iomem *base;
265 	struct amba_device *adev;
266 	const struct vendor_data *vd;
267 	struct pl08x_platform_data *pd;
268 	struct pl08x_phy_chan *phy_chans;
269 	struct dma_pool *pool;
270 	u8 lli_buses;
271 	u8 mem_buses;
272 	u8 lli_words;
273 };
274 
275 /*
276  * PL08X specific defines
277  */
278 
279 /* The order of words in an LLI. */
280 #define PL080_LLI_SRC		0
281 #define PL080_LLI_DST		1
282 #define PL080_LLI_LLI		2
283 #define PL080_LLI_CCTL		3
284 #define PL080S_LLI_CCTL2	4
285 
286 /* Total words in an LLI. */
287 #define PL080_LLI_WORDS		4
288 #define PL080S_LLI_WORDS	8
289 
290 /*
291  * Number of LLIs in each LLI buffer allocated for one transfer
292  * (maximum times we call dma_pool_alloc on this pool without freeing)
293  */
294 #define MAX_NUM_TSFR_LLIS	512
295 #define PL08X_ALIGN		8
296 
297 static inline struct pl08x_dma_chan *to_pl08x_chan(struct dma_chan *chan)
298 {
299 	return container_of(chan, struct pl08x_dma_chan, vc.chan);
300 }
301 
302 static inline struct pl08x_txd *to_pl08x_txd(struct dma_async_tx_descriptor *tx)
303 {
304 	return container_of(tx, struct pl08x_txd, vd.tx);
305 }
306 
307 /*
308  * Mux handling.
309  *
310  * This gives us the DMA request input to the PL08x primecell which the
311  * peripheral described by the channel data will be routed to, possibly
312  * via a board/SoC specific external MUX.  One important point to note
313  * here is that this does not depend on the physical channel.
314  */
315 static int pl08x_request_mux(struct pl08x_dma_chan *plchan)
316 {
317 	const struct pl08x_platform_data *pd = plchan->host->pd;
318 	int ret;
319 
320 	if (plchan->mux_use++ == 0 && pd->get_xfer_signal) {
321 		ret = pd->get_xfer_signal(plchan->cd);
322 		if (ret < 0) {
323 			plchan->mux_use = 0;
324 			return ret;
325 		}
326 
327 		plchan->signal = ret;
328 	}
329 	return 0;
330 }
331 
332 static void pl08x_release_mux(struct pl08x_dma_chan *plchan)
333 {
334 	const struct pl08x_platform_data *pd = plchan->host->pd;
335 
336 	if (plchan->signal >= 0) {
337 		WARN_ON(plchan->mux_use == 0);
338 
339 		if (--plchan->mux_use == 0 && pd->put_xfer_signal) {
340 			pd->put_xfer_signal(plchan->cd, plchan->signal);
341 			plchan->signal = -1;
342 		}
343 	}
344 }
345 
346 /*
347  * Physical channel handling
348  */
349 
350 /* Whether a certain channel is busy or not */
351 static int pl08x_phy_channel_busy(struct pl08x_phy_chan *ch)
352 {
353 	unsigned int val;
354 
355 	val = readl(ch->reg_config);
356 	return val & PL080_CONFIG_ACTIVE;
357 }
358 
359 static void pl08x_write_lli(struct pl08x_driver_data *pl08x,
360 		struct pl08x_phy_chan *phychan, const u32 *lli, u32 ccfg)
361 {
362 	if (pl08x->vd->pl080s)
363 		dev_vdbg(&pl08x->adev->dev,
364 			"WRITE channel %d: csrc=0x%08x, cdst=0x%08x, "
365 			"clli=0x%08x, cctl=0x%08x, cctl2=0x%08x, ccfg=0x%08x\n",
366 			phychan->id, lli[PL080_LLI_SRC], lli[PL080_LLI_DST],
367 			lli[PL080_LLI_LLI], lli[PL080_LLI_CCTL],
368 			lli[PL080S_LLI_CCTL2], ccfg);
369 	else
370 		dev_vdbg(&pl08x->adev->dev,
371 			"WRITE channel %d: csrc=0x%08x, cdst=0x%08x, "
372 			"clli=0x%08x, cctl=0x%08x, ccfg=0x%08x\n",
373 			phychan->id, lli[PL080_LLI_SRC], lli[PL080_LLI_DST],
374 			lli[PL080_LLI_LLI], lli[PL080_LLI_CCTL], ccfg);
375 
376 	writel_relaxed(lli[PL080_LLI_SRC], phychan->base + PL080_CH_SRC_ADDR);
377 	writel_relaxed(lli[PL080_LLI_DST], phychan->base + PL080_CH_DST_ADDR);
378 	writel_relaxed(lli[PL080_LLI_LLI], phychan->base + PL080_CH_LLI);
379 	writel_relaxed(lli[PL080_LLI_CCTL], phychan->base + PL080_CH_CONTROL);
380 
381 	if (pl08x->vd->pl080s)
382 		writel_relaxed(lli[PL080S_LLI_CCTL2],
383 				phychan->base + PL080S_CH_CONTROL2);
384 
385 	writel(ccfg, phychan->reg_config);
386 }
387 
388 /*
389  * Set the initial DMA register values i.e. those for the first LLI
390  * The next LLI pointer and the configuration interrupt bit have
391  * been set when the LLIs were constructed.  Poke them into the hardware
392  * and start the transfer.
393  */
394 static void pl08x_start_next_txd(struct pl08x_dma_chan *plchan)
395 {
396 	struct pl08x_driver_data *pl08x = plchan->host;
397 	struct pl08x_phy_chan *phychan = plchan->phychan;
398 	struct virt_dma_desc *vd = vchan_next_desc(&plchan->vc);
399 	struct pl08x_txd *txd = to_pl08x_txd(&vd->tx);
400 	u32 val;
401 
402 	list_del(&txd->vd.node);
403 
404 	plchan->at = txd;
405 
406 	/* Wait for channel inactive */
407 	while (pl08x_phy_channel_busy(phychan))
408 		cpu_relax();
409 
410 	pl08x_write_lli(pl08x, phychan, &txd->llis_va[0], txd->ccfg);
411 
412 	/* Enable the DMA channel */
413 	/* Do not access config register until channel shows as disabled */
414 	while (readl(pl08x->base + PL080_EN_CHAN) & (1 << phychan->id))
415 		cpu_relax();
416 
417 	/* Do not access config register until channel shows as inactive */
418 	val = readl(phychan->reg_config);
419 	while ((val & PL080_CONFIG_ACTIVE) || (val & PL080_CONFIG_ENABLE))
420 		val = readl(phychan->reg_config);
421 
422 	writel(val | PL080_CONFIG_ENABLE, phychan->reg_config);
423 }
424 
425 /*
426  * Pause the channel by setting the HALT bit.
427  *
428  * For M->P transfers, pause the DMAC first and then stop the peripheral -
429  * the FIFO can only drain if the peripheral is still requesting data.
430  * (note: this can still timeout if the DMAC FIFO never drains of data.)
431  *
432  * For P->M transfers, disable the peripheral first to stop it filling
433  * the DMAC FIFO, and then pause the DMAC.
434  */
435 static void pl08x_pause_phy_chan(struct pl08x_phy_chan *ch)
436 {
437 	u32 val;
438 	int timeout;
439 
440 	/* Set the HALT bit and wait for the FIFO to drain */
441 	val = readl(ch->reg_config);
442 	val |= PL080_CONFIG_HALT;
443 	writel(val, ch->reg_config);
444 
445 	/* Wait for channel inactive */
446 	for (timeout = 1000; timeout; timeout--) {
447 		if (!pl08x_phy_channel_busy(ch))
448 			break;
449 		udelay(1);
450 	}
451 	if (pl08x_phy_channel_busy(ch))
452 		pr_err("pl08x: channel%u timeout waiting for pause\n", ch->id);
453 }
454 
455 static void pl08x_resume_phy_chan(struct pl08x_phy_chan *ch)
456 {
457 	u32 val;
458 
459 	/* Clear the HALT bit */
460 	val = readl(ch->reg_config);
461 	val &= ~PL080_CONFIG_HALT;
462 	writel(val, ch->reg_config);
463 }
464 
465 /*
466  * pl08x_terminate_phy_chan() stops the channel, clears the FIFO and
467  * clears any pending interrupt status.  This should not be used for
468  * an on-going transfer, but as a method of shutting down a channel
469  * (eg, when it's no longer used) or terminating a transfer.
470  */
471 static void pl08x_terminate_phy_chan(struct pl08x_driver_data *pl08x,
472 	struct pl08x_phy_chan *ch)
473 {
474 	u32 val = readl(ch->reg_config);
475 
476 	val &= ~(PL080_CONFIG_ENABLE | PL080_CONFIG_ERR_IRQ_MASK |
477 		 PL080_CONFIG_TC_IRQ_MASK);
478 
479 	writel(val, ch->reg_config);
480 
481 	writel(1 << ch->id, pl08x->base + PL080_ERR_CLEAR);
482 	writel(1 << ch->id, pl08x->base + PL080_TC_CLEAR);
483 }
484 
485 static inline u32 get_bytes_in_cctl(u32 cctl)
486 {
487 	/* The source width defines the number of bytes */
488 	u32 bytes = cctl & PL080_CONTROL_TRANSFER_SIZE_MASK;
489 
490 	cctl &= PL080_CONTROL_SWIDTH_MASK;
491 
492 	switch (cctl >> PL080_CONTROL_SWIDTH_SHIFT) {
493 	case PL080_WIDTH_8BIT:
494 		break;
495 	case PL080_WIDTH_16BIT:
496 		bytes *= 2;
497 		break;
498 	case PL080_WIDTH_32BIT:
499 		bytes *= 4;
500 		break;
501 	}
502 	return bytes;
503 }
504 
505 static inline u32 get_bytes_in_cctl_pl080s(u32 cctl, u32 cctl1)
506 {
507 	/* The source width defines the number of bytes */
508 	u32 bytes = cctl1 & PL080S_CONTROL_TRANSFER_SIZE_MASK;
509 
510 	cctl &= PL080_CONTROL_SWIDTH_MASK;
511 
512 	switch (cctl >> PL080_CONTROL_SWIDTH_SHIFT) {
513 	case PL080_WIDTH_8BIT:
514 		break;
515 	case PL080_WIDTH_16BIT:
516 		bytes *= 2;
517 		break;
518 	case PL080_WIDTH_32BIT:
519 		bytes *= 4;
520 		break;
521 	}
522 	return bytes;
523 }
524 
525 /* The channel should be paused when calling this */
526 static u32 pl08x_getbytes_chan(struct pl08x_dma_chan *plchan)
527 {
528 	struct pl08x_driver_data *pl08x = plchan->host;
529 	const u32 *llis_va, *llis_va_limit;
530 	struct pl08x_phy_chan *ch;
531 	dma_addr_t llis_bus;
532 	struct pl08x_txd *txd;
533 	u32 llis_max_words;
534 	size_t bytes;
535 	u32 clli;
536 
537 	ch = plchan->phychan;
538 	txd = plchan->at;
539 
540 	if (!ch || !txd)
541 		return 0;
542 
543 	/*
544 	 * Follow the LLIs to get the number of remaining
545 	 * bytes in the currently active transaction.
546 	 */
547 	clli = readl(ch->base + PL080_CH_LLI) & ~PL080_LLI_LM_AHB2;
548 
549 	/* First get the remaining bytes in the active transfer */
550 	if (pl08x->vd->pl080s)
551 		bytes = get_bytes_in_cctl_pl080s(
552 				readl(ch->base + PL080_CH_CONTROL),
553 				readl(ch->base + PL080S_CH_CONTROL2));
554 	else
555 		bytes = get_bytes_in_cctl(readl(ch->base + PL080_CH_CONTROL));
556 
557 	if (!clli)
558 		return bytes;
559 
560 	llis_va = txd->llis_va;
561 	llis_bus = txd->llis_bus;
562 
563 	llis_max_words = pl08x->lli_words * MAX_NUM_TSFR_LLIS;
564 	BUG_ON(clli < llis_bus || clli >= llis_bus +
565 						sizeof(u32) * llis_max_words);
566 
567 	/*
568 	 * Locate the next LLI - as this is an array,
569 	 * it's simple maths to find.
570 	 */
571 	llis_va += (clli - llis_bus) / sizeof(u32);
572 
573 	llis_va_limit = llis_va + llis_max_words;
574 
575 	for (; llis_va < llis_va_limit; llis_va += pl08x->lli_words) {
576 		if (pl08x->vd->pl080s)
577 			bytes += get_bytes_in_cctl_pl080s(
578 						llis_va[PL080_LLI_CCTL],
579 						llis_va[PL080S_LLI_CCTL2]);
580 		else
581 			bytes += get_bytes_in_cctl(llis_va[PL080_LLI_CCTL]);
582 
583 		/*
584 		 * A LLI pointer going backward terminates the LLI list
585 		 */
586 		if (llis_va[PL080_LLI_LLI] <= clli)
587 			break;
588 	}
589 
590 	return bytes;
591 }
592 
593 /*
594  * Allocate a physical channel for a virtual channel
595  *
596  * Try to locate a physical channel to be used for this transfer. If all
597  * are taken return NULL and the requester will have to cope by using
598  * some fallback PIO mode or retrying later.
599  */
600 static struct pl08x_phy_chan *
601 pl08x_get_phy_channel(struct pl08x_driver_data *pl08x,
602 		      struct pl08x_dma_chan *virt_chan)
603 {
604 	struct pl08x_phy_chan *ch = NULL;
605 	unsigned long flags;
606 	int i;
607 
608 	for (i = 0; i < pl08x->vd->channels; i++) {
609 		ch = &pl08x->phy_chans[i];
610 
611 		spin_lock_irqsave(&ch->lock, flags);
612 
613 		if (!ch->locked && !ch->serving) {
614 			ch->serving = virt_chan;
615 			spin_unlock_irqrestore(&ch->lock, flags);
616 			break;
617 		}
618 
619 		spin_unlock_irqrestore(&ch->lock, flags);
620 	}
621 
622 	if (i == pl08x->vd->channels) {
623 		/* No physical channel available, cope with it */
624 		return NULL;
625 	}
626 
627 	return ch;
628 }
629 
630 /* Mark the physical channel as free.  Note, this write is atomic. */
631 static inline void pl08x_put_phy_channel(struct pl08x_driver_data *pl08x,
632 					 struct pl08x_phy_chan *ch)
633 {
634 	ch->serving = NULL;
635 }
636 
637 /*
638  * Try to allocate a physical channel.  When successful, assign it to
639  * this virtual channel, and initiate the next descriptor.  The
640  * virtual channel lock must be held at this point.
641  */
642 static void pl08x_phy_alloc_and_start(struct pl08x_dma_chan *plchan)
643 {
644 	struct pl08x_driver_data *pl08x = plchan->host;
645 	struct pl08x_phy_chan *ch;
646 
647 	ch = pl08x_get_phy_channel(pl08x, plchan);
648 	if (!ch) {
649 		dev_dbg(&pl08x->adev->dev, "no physical channel available for xfer on %s\n", plchan->name);
650 		plchan->state = PL08X_CHAN_WAITING;
651 		return;
652 	}
653 
654 	dev_dbg(&pl08x->adev->dev, "allocated physical channel %d for xfer on %s\n",
655 		ch->id, plchan->name);
656 
657 	plchan->phychan = ch;
658 	plchan->state = PL08X_CHAN_RUNNING;
659 	pl08x_start_next_txd(plchan);
660 }
661 
662 static void pl08x_phy_reassign_start(struct pl08x_phy_chan *ch,
663 	struct pl08x_dma_chan *plchan)
664 {
665 	struct pl08x_driver_data *pl08x = plchan->host;
666 
667 	dev_dbg(&pl08x->adev->dev, "reassigned physical channel %d for xfer on %s\n",
668 		ch->id, plchan->name);
669 
670 	/*
671 	 * We do this without taking the lock; we're really only concerned
672 	 * about whether this pointer is NULL or not, and we're guaranteed
673 	 * that this will only be called when it _already_ is non-NULL.
674 	 */
675 	ch->serving = plchan;
676 	plchan->phychan = ch;
677 	plchan->state = PL08X_CHAN_RUNNING;
678 	pl08x_start_next_txd(plchan);
679 }
680 
681 /*
682  * Free a physical DMA channel, potentially reallocating it to another
683  * virtual channel if we have any pending.
684  */
685 static void pl08x_phy_free(struct pl08x_dma_chan *plchan)
686 {
687 	struct pl08x_driver_data *pl08x = plchan->host;
688 	struct pl08x_dma_chan *p, *next;
689 
690  retry:
691 	next = NULL;
692 
693 	/* Find a waiting virtual channel for the next transfer. */
694 	list_for_each_entry(p, &pl08x->memcpy.channels, vc.chan.device_node)
695 		if (p->state == PL08X_CHAN_WAITING) {
696 			next = p;
697 			break;
698 		}
699 
700 	if (!next) {
701 		list_for_each_entry(p, &pl08x->slave.channels, vc.chan.device_node)
702 			if (p->state == PL08X_CHAN_WAITING) {
703 				next = p;
704 				break;
705 			}
706 	}
707 
708 	/* Ensure that the physical channel is stopped */
709 	pl08x_terminate_phy_chan(pl08x, plchan->phychan);
710 
711 	if (next) {
712 		bool success;
713 
714 		/*
715 		 * Eww.  We know this isn't going to deadlock
716 		 * but lockdep probably doesn't.
717 		 */
718 		spin_lock(&next->vc.lock);
719 		/* Re-check the state now that we have the lock */
720 		success = next->state == PL08X_CHAN_WAITING;
721 		if (success)
722 			pl08x_phy_reassign_start(plchan->phychan, next);
723 		spin_unlock(&next->vc.lock);
724 
725 		/* If the state changed, try to find another channel */
726 		if (!success)
727 			goto retry;
728 	} else {
729 		/* No more jobs, so free up the physical channel */
730 		pl08x_put_phy_channel(pl08x, plchan->phychan);
731 	}
732 
733 	plchan->phychan = NULL;
734 	plchan->state = PL08X_CHAN_IDLE;
735 }
736 
737 /*
738  * LLI handling
739  */
740 
741 static inline unsigned int pl08x_get_bytes_for_cctl(unsigned int coded)
742 {
743 	switch (coded) {
744 	case PL080_WIDTH_8BIT:
745 		return 1;
746 	case PL080_WIDTH_16BIT:
747 		return 2;
748 	case PL080_WIDTH_32BIT:
749 		return 4;
750 	default:
751 		break;
752 	}
753 	BUG();
754 	return 0;
755 }
756 
757 static inline u32 pl08x_cctl_bits(u32 cctl, u8 srcwidth, u8 dstwidth,
758 				  size_t tsize)
759 {
760 	u32 retbits = cctl;
761 
762 	/* Remove all src, dst and transfer size bits */
763 	retbits &= ~PL080_CONTROL_DWIDTH_MASK;
764 	retbits &= ~PL080_CONTROL_SWIDTH_MASK;
765 	retbits &= ~PL080_CONTROL_TRANSFER_SIZE_MASK;
766 
767 	/* Then set the bits according to the parameters */
768 	switch (srcwidth) {
769 	case 1:
770 		retbits |= PL080_WIDTH_8BIT << PL080_CONTROL_SWIDTH_SHIFT;
771 		break;
772 	case 2:
773 		retbits |= PL080_WIDTH_16BIT << PL080_CONTROL_SWIDTH_SHIFT;
774 		break;
775 	case 4:
776 		retbits |= PL080_WIDTH_32BIT << PL080_CONTROL_SWIDTH_SHIFT;
777 		break;
778 	default:
779 		BUG();
780 		break;
781 	}
782 
783 	switch (dstwidth) {
784 	case 1:
785 		retbits |= PL080_WIDTH_8BIT << PL080_CONTROL_DWIDTH_SHIFT;
786 		break;
787 	case 2:
788 		retbits |= PL080_WIDTH_16BIT << PL080_CONTROL_DWIDTH_SHIFT;
789 		break;
790 	case 4:
791 		retbits |= PL080_WIDTH_32BIT << PL080_CONTROL_DWIDTH_SHIFT;
792 		break;
793 	default:
794 		BUG();
795 		break;
796 	}
797 
798 	tsize &= PL080_CONTROL_TRANSFER_SIZE_MASK;
799 	retbits |= tsize << PL080_CONTROL_TRANSFER_SIZE_SHIFT;
800 	return retbits;
801 }
802 
803 struct pl08x_lli_build_data {
804 	struct pl08x_txd *txd;
805 	struct pl08x_bus_data srcbus;
806 	struct pl08x_bus_data dstbus;
807 	size_t remainder;
808 	u32 lli_bus;
809 };
810 
811 /*
812  * Autoselect a master bus to use for the transfer. Slave will be the chosen as
813  * victim in case src & dest are not similarly aligned. i.e. If after aligning
814  * masters address with width requirements of transfer (by sending few byte by
815  * byte data), slave is still not aligned, then its width will be reduced to
816  * BYTE.
817  * - prefers the destination bus if both available
818  * - prefers bus with fixed address (i.e. peripheral)
819  */
820 static void pl08x_choose_master_bus(struct pl08x_lli_build_data *bd,
821 	struct pl08x_bus_data **mbus, struct pl08x_bus_data **sbus, u32 cctl)
822 {
823 	if (!(cctl & PL080_CONTROL_DST_INCR)) {
824 		*mbus = &bd->dstbus;
825 		*sbus = &bd->srcbus;
826 	} else if (!(cctl & PL080_CONTROL_SRC_INCR)) {
827 		*mbus = &bd->srcbus;
828 		*sbus = &bd->dstbus;
829 	} else {
830 		if (bd->dstbus.buswidth >= bd->srcbus.buswidth) {
831 			*mbus = &bd->dstbus;
832 			*sbus = &bd->srcbus;
833 		} else {
834 			*mbus = &bd->srcbus;
835 			*sbus = &bd->dstbus;
836 		}
837 	}
838 }
839 
840 /*
841  * Fills in one LLI for a certain transfer descriptor and advance the counter
842  */
843 static void pl08x_fill_lli_for_desc(struct pl08x_driver_data *pl08x,
844 				    struct pl08x_lli_build_data *bd,
845 				    int num_llis, int len, u32 cctl, u32 cctl2)
846 {
847 	u32 offset = num_llis * pl08x->lli_words;
848 	u32 *llis_va = bd->txd->llis_va + offset;
849 	dma_addr_t llis_bus = bd->txd->llis_bus;
850 
851 	BUG_ON(num_llis >= MAX_NUM_TSFR_LLIS);
852 
853 	/* Advance the offset to next LLI. */
854 	offset += pl08x->lli_words;
855 
856 	llis_va[PL080_LLI_SRC] = bd->srcbus.addr;
857 	llis_va[PL080_LLI_DST] = bd->dstbus.addr;
858 	llis_va[PL080_LLI_LLI] = (llis_bus + sizeof(u32) * offset);
859 	llis_va[PL080_LLI_LLI] |= bd->lli_bus;
860 	llis_va[PL080_LLI_CCTL] = cctl;
861 	if (pl08x->vd->pl080s)
862 		llis_va[PL080S_LLI_CCTL2] = cctl2;
863 
864 	if (cctl & PL080_CONTROL_SRC_INCR)
865 		bd->srcbus.addr += len;
866 	if (cctl & PL080_CONTROL_DST_INCR)
867 		bd->dstbus.addr += len;
868 
869 	BUG_ON(bd->remainder < len);
870 
871 	bd->remainder -= len;
872 }
873 
874 static inline void prep_byte_width_lli(struct pl08x_driver_data *pl08x,
875 			struct pl08x_lli_build_data *bd, u32 *cctl, u32 len,
876 			int num_llis, size_t *total_bytes)
877 {
878 	*cctl = pl08x_cctl_bits(*cctl, 1, 1, len);
879 	pl08x_fill_lli_for_desc(pl08x, bd, num_llis, len, *cctl, len);
880 	(*total_bytes) += len;
881 }
882 
883 #ifdef VERBOSE_DEBUG
884 static void pl08x_dump_lli(struct pl08x_driver_data *pl08x,
885 			   const u32 *llis_va, int num_llis)
886 {
887 	int i;
888 
889 	if (pl08x->vd->pl080s) {
890 		dev_vdbg(&pl08x->adev->dev,
891 			"%-3s %-9s  %-10s %-10s %-10s %-10s %s\n",
892 			"lli", "", "csrc", "cdst", "clli", "cctl", "cctl2");
893 		for (i = 0; i < num_llis; i++) {
894 			dev_vdbg(&pl08x->adev->dev,
895 				"%3d @%p: 0x%08x 0x%08x 0x%08x 0x%08x 0x%08x\n",
896 				i, llis_va, llis_va[PL080_LLI_SRC],
897 				llis_va[PL080_LLI_DST], llis_va[PL080_LLI_LLI],
898 				llis_va[PL080_LLI_CCTL],
899 				llis_va[PL080S_LLI_CCTL2]);
900 			llis_va += pl08x->lli_words;
901 		}
902 	} else {
903 		dev_vdbg(&pl08x->adev->dev,
904 			"%-3s %-9s  %-10s %-10s %-10s %s\n",
905 			"lli", "", "csrc", "cdst", "clli", "cctl");
906 		for (i = 0; i < num_llis; i++) {
907 			dev_vdbg(&pl08x->adev->dev,
908 				"%3d @%p: 0x%08x 0x%08x 0x%08x 0x%08x\n",
909 				i, llis_va, llis_va[PL080_LLI_SRC],
910 				llis_va[PL080_LLI_DST], llis_va[PL080_LLI_LLI],
911 				llis_va[PL080_LLI_CCTL]);
912 			llis_va += pl08x->lli_words;
913 		}
914 	}
915 }
916 #else
917 static inline void pl08x_dump_lli(struct pl08x_driver_data *pl08x,
918 				  const u32 *llis_va, int num_llis) {}
919 #endif
920 
921 /*
922  * This fills in the table of LLIs for the transfer descriptor
923  * Note that we assume we never have to change the burst sizes
924  * Return 0 for error
925  */
926 static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
927 			      struct pl08x_txd *txd)
928 {
929 	struct pl08x_bus_data *mbus, *sbus;
930 	struct pl08x_lli_build_data bd;
931 	int num_llis = 0;
932 	u32 cctl, early_bytes = 0;
933 	size_t max_bytes_per_lli, total_bytes;
934 	u32 *llis_va, *last_lli;
935 	struct pl08x_sg *dsg;
936 
937 	txd->llis_va = dma_pool_alloc(pl08x->pool, GFP_NOWAIT, &txd->llis_bus);
938 	if (!txd->llis_va) {
939 		dev_err(&pl08x->adev->dev, "%s no memory for llis\n", __func__);
940 		return 0;
941 	}
942 
943 	bd.txd = txd;
944 	bd.lli_bus = (pl08x->lli_buses & PL08X_AHB2) ? PL080_LLI_LM_AHB2 : 0;
945 	cctl = txd->cctl;
946 
947 	/* Find maximum width of the source bus */
948 	bd.srcbus.maxwidth =
949 		pl08x_get_bytes_for_cctl((cctl & PL080_CONTROL_SWIDTH_MASK) >>
950 				       PL080_CONTROL_SWIDTH_SHIFT);
951 
952 	/* Find maximum width of the destination bus */
953 	bd.dstbus.maxwidth =
954 		pl08x_get_bytes_for_cctl((cctl & PL080_CONTROL_DWIDTH_MASK) >>
955 				       PL080_CONTROL_DWIDTH_SHIFT);
956 
957 	list_for_each_entry(dsg, &txd->dsg_list, node) {
958 		total_bytes = 0;
959 		cctl = txd->cctl;
960 
961 		bd.srcbus.addr = dsg->src_addr;
962 		bd.dstbus.addr = dsg->dst_addr;
963 		bd.remainder = dsg->len;
964 		bd.srcbus.buswidth = bd.srcbus.maxwidth;
965 		bd.dstbus.buswidth = bd.dstbus.maxwidth;
966 
967 		pl08x_choose_master_bus(&bd, &mbus, &sbus, cctl);
968 
969 		dev_vdbg(&pl08x->adev->dev,
970 			"src=0x%08llx%s/%u dst=0x%08llx%s/%u len=%zu\n",
971 			(u64)bd.srcbus.addr,
972 			cctl & PL080_CONTROL_SRC_INCR ? "+" : "",
973 			bd.srcbus.buswidth,
974 			(u64)bd.dstbus.addr,
975 			cctl & PL080_CONTROL_DST_INCR ? "+" : "",
976 			bd.dstbus.buswidth,
977 			bd.remainder);
978 		dev_vdbg(&pl08x->adev->dev, "mbus=%s sbus=%s\n",
979 			mbus == &bd.srcbus ? "src" : "dst",
980 			sbus == &bd.srcbus ? "src" : "dst");
981 
982 		/*
983 		 * Zero length is only allowed if all these requirements are
984 		 * met:
985 		 * - flow controller is peripheral.
986 		 * - src.addr is aligned to src.width
987 		 * - dst.addr is aligned to dst.width
988 		 *
989 		 * sg_len == 1 should be true, as there can be two cases here:
990 		 *
991 		 * - Memory addresses are contiguous and are not scattered.
992 		 *   Here, Only one sg will be passed by user driver, with
993 		 *   memory address and zero length. We pass this to controller
994 		 *   and after the transfer it will receive the last burst
995 		 *   request from peripheral and so transfer finishes.
996 		 *
997 		 * - Memory addresses are scattered and are not contiguous.
998 		 *   Here, Obviously as DMA controller doesn't know when a lli's
999 		 *   transfer gets over, it can't load next lli. So in this
1000 		 *   case, there has to be an assumption that only one lli is
1001 		 *   supported. Thus, we can't have scattered addresses.
1002 		 */
1003 		if (!bd.remainder) {
1004 			u32 fc = (txd->ccfg & PL080_CONFIG_FLOW_CONTROL_MASK) >>
1005 				PL080_CONFIG_FLOW_CONTROL_SHIFT;
1006 			if (!((fc >= PL080_FLOW_SRC2DST_DST) &&
1007 					(fc <= PL080_FLOW_SRC2DST_SRC))) {
1008 				dev_err(&pl08x->adev->dev, "%s sg len can't be zero",
1009 					__func__);
1010 				return 0;
1011 			}
1012 
1013 			if (!IS_BUS_ALIGNED(&bd.srcbus) ||
1014 				!IS_BUS_ALIGNED(&bd.dstbus)) {
1015 				dev_err(&pl08x->adev->dev,
1016 					"%s src & dst address must be aligned to src"
1017 					" & dst width if peripheral is flow controller",
1018 					__func__);
1019 				return 0;
1020 			}
1021 
1022 			cctl = pl08x_cctl_bits(cctl, bd.srcbus.buswidth,
1023 					bd.dstbus.buswidth, 0);
1024 			pl08x_fill_lli_for_desc(pl08x, &bd, num_llis++,
1025 					0, cctl, 0);
1026 			break;
1027 		}
1028 
1029 		/*
1030 		 * Send byte by byte for following cases
1031 		 * - Less than a bus width available
1032 		 * - until master bus is aligned
1033 		 */
1034 		if (bd.remainder < mbus->buswidth)
1035 			early_bytes = bd.remainder;
1036 		else if (!IS_BUS_ALIGNED(mbus)) {
1037 			early_bytes = mbus->buswidth -
1038 				(mbus->addr & (mbus->buswidth - 1));
1039 			if ((bd.remainder - early_bytes) < mbus->buswidth)
1040 				early_bytes = bd.remainder;
1041 		}
1042 
1043 		if (early_bytes) {
1044 			dev_vdbg(&pl08x->adev->dev,
1045 				"%s byte width LLIs (remain 0x%08zx)\n",
1046 				__func__, bd.remainder);
1047 			prep_byte_width_lli(pl08x, &bd, &cctl, early_bytes,
1048 				num_llis++, &total_bytes);
1049 		}
1050 
1051 		if (bd.remainder) {
1052 			/*
1053 			 * Master now aligned
1054 			 * - if slave is not then we must set its width down
1055 			 */
1056 			if (!IS_BUS_ALIGNED(sbus)) {
1057 				dev_dbg(&pl08x->adev->dev,
1058 					"%s set down bus width to one byte\n",
1059 					__func__);
1060 
1061 				sbus->buswidth = 1;
1062 			}
1063 
1064 			/*
1065 			 * Bytes transferred = tsize * src width, not
1066 			 * MIN(buswidths)
1067 			 */
1068 			max_bytes_per_lli = bd.srcbus.buswidth *
1069 						pl08x->vd->max_transfer_size;
1070 			dev_vdbg(&pl08x->adev->dev,
1071 				"%s max bytes per lli = %zu\n",
1072 				__func__, max_bytes_per_lli);
1073 
1074 			/*
1075 			 * Make largest possible LLIs until less than one bus
1076 			 * width left
1077 			 */
1078 			while (bd.remainder > (mbus->buswidth - 1)) {
1079 				size_t lli_len, tsize, width;
1080 
1081 				/*
1082 				 * If enough left try to send max possible,
1083 				 * otherwise try to send the remainder
1084 				 */
1085 				lli_len = min(bd.remainder, max_bytes_per_lli);
1086 
1087 				/*
1088 				 * Check against maximum bus alignment:
1089 				 * Calculate actual transfer size in relation to
1090 				 * bus width an get a maximum remainder of the
1091 				 * highest bus width - 1
1092 				 */
1093 				width = max(mbus->buswidth, sbus->buswidth);
1094 				lli_len = (lli_len / width) * width;
1095 				tsize = lli_len / bd.srcbus.buswidth;
1096 
1097 				dev_vdbg(&pl08x->adev->dev,
1098 					"%s fill lli with single lli chunk of "
1099 					"size 0x%08zx (remainder 0x%08zx)\n",
1100 					__func__, lli_len, bd.remainder);
1101 
1102 				cctl = pl08x_cctl_bits(cctl, bd.srcbus.buswidth,
1103 					bd.dstbus.buswidth, tsize);
1104 				pl08x_fill_lli_for_desc(pl08x, &bd, num_llis++,
1105 						lli_len, cctl, tsize);
1106 				total_bytes += lli_len;
1107 			}
1108 
1109 			/*
1110 			 * Send any odd bytes
1111 			 */
1112 			if (bd.remainder) {
1113 				dev_vdbg(&pl08x->adev->dev,
1114 					"%s align with boundary, send odd bytes (remain %zu)\n",
1115 					__func__, bd.remainder);
1116 				prep_byte_width_lli(pl08x, &bd, &cctl,
1117 					bd.remainder, num_llis++, &total_bytes);
1118 			}
1119 		}
1120 
1121 		if (total_bytes != dsg->len) {
1122 			dev_err(&pl08x->adev->dev,
1123 				"%s size of encoded lli:s don't match total txd, transferred 0x%08zx from size 0x%08zx\n",
1124 				__func__, total_bytes, dsg->len);
1125 			return 0;
1126 		}
1127 
1128 		if (num_llis >= MAX_NUM_TSFR_LLIS) {
1129 			dev_err(&pl08x->adev->dev,
1130 				"%s need to increase MAX_NUM_TSFR_LLIS from 0x%08x\n",
1131 				__func__, MAX_NUM_TSFR_LLIS);
1132 			return 0;
1133 		}
1134 	}
1135 
1136 	llis_va = txd->llis_va;
1137 	last_lli = llis_va + (num_llis - 1) * pl08x->lli_words;
1138 
1139 	if (txd->cyclic) {
1140 		/* Link back to the first LLI. */
1141 		last_lli[PL080_LLI_LLI] = txd->llis_bus | bd.lli_bus;
1142 	} else {
1143 		/* The final LLI terminates the LLI. */
1144 		last_lli[PL080_LLI_LLI] = 0;
1145 		/* The final LLI element shall also fire an interrupt. */
1146 		last_lli[PL080_LLI_CCTL] |= PL080_CONTROL_TC_IRQ_EN;
1147 	}
1148 
1149 	pl08x_dump_lli(pl08x, llis_va, num_llis);
1150 
1151 	return num_llis;
1152 }
1153 
1154 static void pl08x_free_txd(struct pl08x_driver_data *pl08x,
1155 			   struct pl08x_txd *txd)
1156 {
1157 	struct pl08x_sg *dsg, *_dsg;
1158 
1159 	if (txd->llis_va)
1160 		dma_pool_free(pl08x->pool, txd->llis_va, txd->llis_bus);
1161 
1162 	list_for_each_entry_safe(dsg, _dsg, &txd->dsg_list, node) {
1163 		list_del(&dsg->node);
1164 		kfree(dsg);
1165 	}
1166 
1167 	kfree(txd);
1168 }
1169 
1170 static void pl08x_desc_free(struct virt_dma_desc *vd)
1171 {
1172 	struct pl08x_txd *txd = to_pl08x_txd(&vd->tx);
1173 	struct pl08x_dma_chan *plchan = to_pl08x_chan(vd->tx.chan);
1174 
1175 	dma_descriptor_unmap(&vd->tx);
1176 	if (!txd->done)
1177 		pl08x_release_mux(plchan);
1178 
1179 	pl08x_free_txd(plchan->host, txd);
1180 }
1181 
1182 static void pl08x_free_txd_list(struct pl08x_driver_data *pl08x,
1183 				struct pl08x_dma_chan *plchan)
1184 {
1185 	LIST_HEAD(head);
1186 
1187 	vchan_get_all_descriptors(&plchan->vc, &head);
1188 	vchan_dma_desc_free_list(&plchan->vc, &head);
1189 }
1190 
1191 /*
1192  * The DMA ENGINE API
1193  */
1194 static void pl08x_free_chan_resources(struct dma_chan *chan)
1195 {
1196 	/* Ensure all queued descriptors are freed */
1197 	vchan_free_chan_resources(to_virt_chan(chan));
1198 }
1199 
1200 static struct dma_async_tx_descriptor *pl08x_prep_dma_interrupt(
1201 		struct dma_chan *chan, unsigned long flags)
1202 {
1203 	struct dma_async_tx_descriptor *retval = NULL;
1204 
1205 	return retval;
1206 }
1207 
1208 /*
1209  * Code accessing dma_async_is_complete() in a tight loop may give problems.
1210  * If slaves are relying on interrupts to signal completion this function
1211  * must not be called with interrupts disabled.
1212  */
1213 static enum dma_status pl08x_dma_tx_status(struct dma_chan *chan,
1214 		dma_cookie_t cookie, struct dma_tx_state *txstate)
1215 {
1216 	struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
1217 	struct virt_dma_desc *vd;
1218 	unsigned long flags;
1219 	enum dma_status ret;
1220 	size_t bytes = 0;
1221 
1222 	ret = dma_cookie_status(chan, cookie, txstate);
1223 	if (ret == DMA_COMPLETE)
1224 		return ret;
1225 
1226 	/*
1227 	 * There's no point calculating the residue if there's
1228 	 * no txstate to store the value.
1229 	 */
1230 	if (!txstate) {
1231 		if (plchan->state == PL08X_CHAN_PAUSED)
1232 			ret = DMA_PAUSED;
1233 		return ret;
1234 	}
1235 
1236 	spin_lock_irqsave(&plchan->vc.lock, flags);
1237 	ret = dma_cookie_status(chan, cookie, txstate);
1238 	if (ret != DMA_COMPLETE) {
1239 		vd = vchan_find_desc(&plchan->vc, cookie);
1240 		if (vd) {
1241 			/* On the issued list, so hasn't been processed yet */
1242 			struct pl08x_txd *txd = to_pl08x_txd(&vd->tx);
1243 			struct pl08x_sg *dsg;
1244 
1245 			list_for_each_entry(dsg, &txd->dsg_list, node)
1246 				bytes += dsg->len;
1247 		} else {
1248 			bytes = pl08x_getbytes_chan(plchan);
1249 		}
1250 	}
1251 	spin_unlock_irqrestore(&plchan->vc.lock, flags);
1252 
1253 	/*
1254 	 * This cookie not complete yet
1255 	 * Get number of bytes left in the active transactions and queue
1256 	 */
1257 	dma_set_residue(txstate, bytes);
1258 
1259 	if (plchan->state == PL08X_CHAN_PAUSED && ret == DMA_IN_PROGRESS)
1260 		ret = DMA_PAUSED;
1261 
1262 	/* Whether waiting or running, we're in progress */
1263 	return ret;
1264 }
1265 
1266 /* PrimeCell DMA extension */
1267 struct burst_table {
1268 	u32 burstwords;
1269 	u32 reg;
1270 };
1271 
1272 static const struct burst_table burst_sizes[] = {
1273 	{
1274 		.burstwords = 256,
1275 		.reg = PL080_BSIZE_256,
1276 	},
1277 	{
1278 		.burstwords = 128,
1279 		.reg = PL080_BSIZE_128,
1280 	},
1281 	{
1282 		.burstwords = 64,
1283 		.reg = PL080_BSIZE_64,
1284 	},
1285 	{
1286 		.burstwords = 32,
1287 		.reg = PL080_BSIZE_32,
1288 	},
1289 	{
1290 		.burstwords = 16,
1291 		.reg = PL080_BSIZE_16,
1292 	},
1293 	{
1294 		.burstwords = 8,
1295 		.reg = PL080_BSIZE_8,
1296 	},
1297 	{
1298 		.burstwords = 4,
1299 		.reg = PL080_BSIZE_4,
1300 	},
1301 	{
1302 		.burstwords = 0,
1303 		.reg = PL080_BSIZE_1,
1304 	},
1305 };
1306 
1307 /*
1308  * Given the source and destination available bus masks, select which
1309  * will be routed to each port.  We try to have source and destination
1310  * on separate ports, but always respect the allowable settings.
1311  */
1312 static u32 pl08x_select_bus(u8 src, u8 dst)
1313 {
1314 	u32 cctl = 0;
1315 
1316 	if (!(dst & PL08X_AHB1) || ((dst & PL08X_AHB2) && (src & PL08X_AHB1)))
1317 		cctl |= PL080_CONTROL_DST_AHB2;
1318 	if (!(src & PL08X_AHB1) || ((src & PL08X_AHB2) && !(dst & PL08X_AHB2)))
1319 		cctl |= PL080_CONTROL_SRC_AHB2;
1320 
1321 	return cctl;
1322 }
1323 
1324 static u32 pl08x_cctl(u32 cctl)
1325 {
1326 	cctl &= ~(PL080_CONTROL_SRC_AHB2 | PL080_CONTROL_DST_AHB2 |
1327 		  PL080_CONTROL_SRC_INCR | PL080_CONTROL_DST_INCR |
1328 		  PL080_CONTROL_PROT_MASK);
1329 
1330 	/* Access the cell in privileged mode, non-bufferable, non-cacheable */
1331 	return cctl | PL080_CONTROL_PROT_SYS;
1332 }
1333 
1334 static u32 pl08x_width(enum dma_slave_buswidth width)
1335 {
1336 	switch (width) {
1337 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
1338 		return PL080_WIDTH_8BIT;
1339 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
1340 		return PL080_WIDTH_16BIT;
1341 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
1342 		return PL080_WIDTH_32BIT;
1343 	default:
1344 		return ~0;
1345 	}
1346 }
1347 
1348 static u32 pl08x_burst(u32 maxburst)
1349 {
1350 	int i;
1351 
1352 	for (i = 0; i < ARRAY_SIZE(burst_sizes); i++)
1353 		if (burst_sizes[i].burstwords <= maxburst)
1354 			break;
1355 
1356 	return burst_sizes[i].reg;
1357 }
1358 
1359 static u32 pl08x_get_cctl(struct pl08x_dma_chan *plchan,
1360 	enum dma_slave_buswidth addr_width, u32 maxburst)
1361 {
1362 	u32 width, burst, cctl = 0;
1363 
1364 	width = pl08x_width(addr_width);
1365 	if (width == ~0)
1366 		return ~0;
1367 
1368 	cctl |= width << PL080_CONTROL_SWIDTH_SHIFT;
1369 	cctl |= width << PL080_CONTROL_DWIDTH_SHIFT;
1370 
1371 	/*
1372 	 * If this channel will only request single transfers, set this
1373 	 * down to ONE element.  Also select one element if no maxburst
1374 	 * is specified.
1375 	 */
1376 	if (plchan->cd->single)
1377 		maxburst = 1;
1378 
1379 	burst = pl08x_burst(maxburst);
1380 	cctl |= burst << PL080_CONTROL_SB_SIZE_SHIFT;
1381 	cctl |= burst << PL080_CONTROL_DB_SIZE_SHIFT;
1382 
1383 	return pl08x_cctl(cctl);
1384 }
1385 
1386 /*
1387  * Slave transactions callback to the slave device to allow
1388  * synchronization of slave DMA signals with the DMAC enable
1389  */
1390 static void pl08x_issue_pending(struct dma_chan *chan)
1391 {
1392 	struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
1393 	unsigned long flags;
1394 
1395 	spin_lock_irqsave(&plchan->vc.lock, flags);
1396 	if (vchan_issue_pending(&plchan->vc)) {
1397 		if (!plchan->phychan && plchan->state != PL08X_CHAN_WAITING)
1398 			pl08x_phy_alloc_and_start(plchan);
1399 	}
1400 	spin_unlock_irqrestore(&plchan->vc.lock, flags);
1401 }
1402 
1403 static struct pl08x_txd *pl08x_get_txd(struct pl08x_dma_chan *plchan)
1404 {
1405 	struct pl08x_txd *txd = kzalloc(sizeof(*txd), GFP_NOWAIT);
1406 
1407 	if (txd) {
1408 		INIT_LIST_HEAD(&txd->dsg_list);
1409 
1410 		/* Always enable error and terminal interrupts */
1411 		txd->ccfg = PL080_CONFIG_ERR_IRQ_MASK |
1412 			    PL080_CONFIG_TC_IRQ_MASK;
1413 	}
1414 	return txd;
1415 }
1416 
1417 /*
1418  * Initialize a descriptor to be used by memcpy submit
1419  */
1420 static struct dma_async_tx_descriptor *pl08x_prep_dma_memcpy(
1421 		struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
1422 		size_t len, unsigned long flags)
1423 {
1424 	struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
1425 	struct pl08x_driver_data *pl08x = plchan->host;
1426 	struct pl08x_txd *txd;
1427 	struct pl08x_sg *dsg;
1428 	int ret;
1429 
1430 	txd = pl08x_get_txd(plchan);
1431 	if (!txd) {
1432 		dev_err(&pl08x->adev->dev,
1433 			"%s no memory for descriptor\n", __func__);
1434 		return NULL;
1435 	}
1436 
1437 	dsg = kzalloc(sizeof(struct pl08x_sg), GFP_NOWAIT);
1438 	if (!dsg) {
1439 		pl08x_free_txd(pl08x, txd);
1440 		dev_err(&pl08x->adev->dev, "%s no memory for pl080 sg\n",
1441 				__func__);
1442 		return NULL;
1443 	}
1444 	list_add_tail(&dsg->node, &txd->dsg_list);
1445 
1446 	dsg->src_addr = src;
1447 	dsg->dst_addr = dest;
1448 	dsg->len = len;
1449 
1450 	/* Set platform data for m2m */
1451 	txd->ccfg |= PL080_FLOW_MEM2MEM << PL080_CONFIG_FLOW_CONTROL_SHIFT;
1452 	txd->cctl = pl08x->pd->memcpy_channel.cctl_memcpy &
1453 			~(PL080_CONTROL_DST_AHB2 | PL080_CONTROL_SRC_AHB2);
1454 
1455 	/* Both to be incremented or the code will break */
1456 	txd->cctl |= PL080_CONTROL_SRC_INCR | PL080_CONTROL_DST_INCR;
1457 
1458 	if (pl08x->vd->dualmaster)
1459 		txd->cctl |= pl08x_select_bus(pl08x->mem_buses,
1460 					      pl08x->mem_buses);
1461 
1462 	ret = pl08x_fill_llis_for_desc(plchan->host, txd);
1463 	if (!ret) {
1464 		pl08x_free_txd(pl08x, txd);
1465 		return NULL;
1466 	}
1467 
1468 	return vchan_tx_prep(&plchan->vc, &txd->vd, flags);
1469 }
1470 
1471 static struct pl08x_txd *pl08x_init_txd(
1472 		struct dma_chan *chan,
1473 		enum dma_transfer_direction direction,
1474 		dma_addr_t *slave_addr)
1475 {
1476 	struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
1477 	struct pl08x_driver_data *pl08x = plchan->host;
1478 	struct pl08x_txd *txd;
1479 	enum dma_slave_buswidth addr_width;
1480 	int ret, tmp;
1481 	u8 src_buses, dst_buses;
1482 	u32 maxburst, cctl;
1483 
1484 	txd = pl08x_get_txd(plchan);
1485 	if (!txd) {
1486 		dev_err(&pl08x->adev->dev, "%s no txd\n", __func__);
1487 		return NULL;
1488 	}
1489 
1490 	/*
1491 	 * Set up addresses, the PrimeCell configured address
1492 	 * will take precedence since this may configure the
1493 	 * channel target address dynamically at runtime.
1494 	 */
1495 	if (direction == DMA_MEM_TO_DEV) {
1496 		cctl = PL080_CONTROL_SRC_INCR;
1497 		*slave_addr = plchan->cfg.dst_addr;
1498 		addr_width = plchan->cfg.dst_addr_width;
1499 		maxburst = plchan->cfg.dst_maxburst;
1500 		src_buses = pl08x->mem_buses;
1501 		dst_buses = plchan->cd->periph_buses;
1502 	} else if (direction == DMA_DEV_TO_MEM) {
1503 		cctl = PL080_CONTROL_DST_INCR;
1504 		*slave_addr = plchan->cfg.src_addr;
1505 		addr_width = plchan->cfg.src_addr_width;
1506 		maxburst = plchan->cfg.src_maxburst;
1507 		src_buses = plchan->cd->periph_buses;
1508 		dst_buses = pl08x->mem_buses;
1509 	} else {
1510 		pl08x_free_txd(pl08x, txd);
1511 		dev_err(&pl08x->adev->dev,
1512 			"%s direction unsupported\n", __func__);
1513 		return NULL;
1514 	}
1515 
1516 	cctl |= pl08x_get_cctl(plchan, addr_width, maxburst);
1517 	if (cctl == ~0) {
1518 		pl08x_free_txd(pl08x, txd);
1519 		dev_err(&pl08x->adev->dev,
1520 			"DMA slave configuration botched?\n");
1521 		return NULL;
1522 	}
1523 
1524 	txd->cctl = cctl | pl08x_select_bus(src_buses, dst_buses);
1525 
1526 	if (plchan->cfg.device_fc)
1527 		tmp = (direction == DMA_MEM_TO_DEV) ? PL080_FLOW_MEM2PER_PER :
1528 			PL080_FLOW_PER2MEM_PER;
1529 	else
1530 		tmp = (direction == DMA_MEM_TO_DEV) ? PL080_FLOW_MEM2PER :
1531 			PL080_FLOW_PER2MEM;
1532 
1533 	txd->ccfg |= tmp << PL080_CONFIG_FLOW_CONTROL_SHIFT;
1534 
1535 	ret = pl08x_request_mux(plchan);
1536 	if (ret < 0) {
1537 		pl08x_free_txd(pl08x, txd);
1538 		dev_dbg(&pl08x->adev->dev,
1539 			"unable to mux for transfer on %s due to platform restrictions\n",
1540 			plchan->name);
1541 		return NULL;
1542 	}
1543 
1544 	dev_dbg(&pl08x->adev->dev, "allocated DMA request signal %d for xfer on %s\n",
1545 		 plchan->signal, plchan->name);
1546 
1547 	/* Assign the flow control signal to this channel */
1548 	if (direction == DMA_MEM_TO_DEV)
1549 		txd->ccfg |= plchan->signal << PL080_CONFIG_DST_SEL_SHIFT;
1550 	else
1551 		txd->ccfg |= plchan->signal << PL080_CONFIG_SRC_SEL_SHIFT;
1552 
1553 	return txd;
1554 }
1555 
1556 static int pl08x_tx_add_sg(struct pl08x_txd *txd,
1557 			   enum dma_transfer_direction direction,
1558 			   dma_addr_t slave_addr,
1559 			   dma_addr_t buf_addr,
1560 			   unsigned int len)
1561 {
1562 	struct pl08x_sg *dsg;
1563 
1564 	dsg = kzalloc(sizeof(struct pl08x_sg), GFP_NOWAIT);
1565 	if (!dsg)
1566 		return -ENOMEM;
1567 
1568 	list_add_tail(&dsg->node, &txd->dsg_list);
1569 
1570 	dsg->len = len;
1571 	if (direction == DMA_MEM_TO_DEV) {
1572 		dsg->src_addr = buf_addr;
1573 		dsg->dst_addr = slave_addr;
1574 	} else {
1575 		dsg->src_addr = slave_addr;
1576 		dsg->dst_addr = buf_addr;
1577 	}
1578 
1579 	return 0;
1580 }
1581 
1582 static struct dma_async_tx_descriptor *pl08x_prep_slave_sg(
1583 		struct dma_chan *chan, struct scatterlist *sgl,
1584 		unsigned int sg_len, enum dma_transfer_direction direction,
1585 		unsigned long flags, void *context)
1586 {
1587 	struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
1588 	struct pl08x_driver_data *pl08x = plchan->host;
1589 	struct pl08x_txd *txd;
1590 	struct scatterlist *sg;
1591 	int ret, tmp;
1592 	dma_addr_t slave_addr;
1593 
1594 	dev_dbg(&pl08x->adev->dev, "%s prepare transaction of %d bytes from %s\n",
1595 			__func__, sg_dma_len(sgl), plchan->name);
1596 
1597 	txd = pl08x_init_txd(chan, direction, &slave_addr);
1598 	if (!txd)
1599 		return NULL;
1600 
1601 	for_each_sg(sgl, sg, sg_len, tmp) {
1602 		ret = pl08x_tx_add_sg(txd, direction, slave_addr,
1603 				      sg_dma_address(sg),
1604 				      sg_dma_len(sg));
1605 		if (ret) {
1606 			pl08x_release_mux(plchan);
1607 			pl08x_free_txd(pl08x, txd);
1608 			dev_err(&pl08x->adev->dev, "%s no mem for pl080 sg\n",
1609 					__func__);
1610 			return NULL;
1611 		}
1612 	}
1613 
1614 	ret = pl08x_fill_llis_for_desc(plchan->host, txd);
1615 	if (!ret) {
1616 		pl08x_release_mux(plchan);
1617 		pl08x_free_txd(pl08x, txd);
1618 		return NULL;
1619 	}
1620 
1621 	return vchan_tx_prep(&plchan->vc, &txd->vd, flags);
1622 }
1623 
1624 static struct dma_async_tx_descriptor *pl08x_prep_dma_cyclic(
1625 		struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
1626 		size_t period_len, enum dma_transfer_direction direction,
1627 		unsigned long flags)
1628 {
1629 	struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
1630 	struct pl08x_driver_data *pl08x = plchan->host;
1631 	struct pl08x_txd *txd;
1632 	int ret, tmp;
1633 	dma_addr_t slave_addr;
1634 
1635 	dev_dbg(&pl08x->adev->dev,
1636 		"%s prepare cyclic transaction of %zd/%zd bytes %s %s\n",
1637 		__func__, period_len, buf_len,
1638 		direction == DMA_MEM_TO_DEV ? "to" : "from",
1639 		plchan->name);
1640 
1641 	txd = pl08x_init_txd(chan, direction, &slave_addr);
1642 	if (!txd)
1643 		return NULL;
1644 
1645 	txd->cyclic = true;
1646 	txd->cctl |= PL080_CONTROL_TC_IRQ_EN;
1647 	for (tmp = 0; tmp < buf_len; tmp += period_len) {
1648 		ret = pl08x_tx_add_sg(txd, direction, slave_addr,
1649 				      buf_addr + tmp, period_len);
1650 		if (ret) {
1651 			pl08x_release_mux(plchan);
1652 			pl08x_free_txd(pl08x, txd);
1653 			return NULL;
1654 		}
1655 	}
1656 
1657 	ret = pl08x_fill_llis_for_desc(plchan->host, txd);
1658 	if (!ret) {
1659 		pl08x_release_mux(plchan);
1660 		pl08x_free_txd(pl08x, txd);
1661 		return NULL;
1662 	}
1663 
1664 	return vchan_tx_prep(&plchan->vc, &txd->vd, flags);
1665 }
1666 
1667 static int pl08x_config(struct dma_chan *chan,
1668 			struct dma_slave_config *config)
1669 {
1670 	struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
1671 	struct pl08x_driver_data *pl08x = plchan->host;
1672 
1673 	if (!plchan->slave)
1674 		return -EINVAL;
1675 
1676 	/* Reject definitely invalid configurations */
1677 	if (config->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES ||
1678 	    config->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
1679 		return -EINVAL;
1680 
1681 	if (config->device_fc && pl08x->vd->pl080s) {
1682 		dev_err(&pl08x->adev->dev,
1683 			"%s: PL080S does not support peripheral flow control\n",
1684 			__func__);
1685 		return -EINVAL;
1686 	}
1687 
1688 	plchan->cfg = *config;
1689 
1690 	return 0;
1691 }
1692 
1693 static int pl08x_terminate_all(struct dma_chan *chan)
1694 {
1695 	struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
1696 	struct pl08x_driver_data *pl08x = plchan->host;
1697 	unsigned long flags;
1698 
1699 	spin_lock_irqsave(&plchan->vc.lock, flags);
1700 	if (!plchan->phychan && !plchan->at) {
1701 		spin_unlock_irqrestore(&plchan->vc.lock, flags);
1702 		return 0;
1703 	}
1704 
1705 	plchan->state = PL08X_CHAN_IDLE;
1706 
1707 	if (plchan->phychan) {
1708 		/*
1709 		 * Mark physical channel as free and free any slave
1710 		 * signal
1711 		 */
1712 		pl08x_phy_free(plchan);
1713 	}
1714 	/* Dequeue jobs and free LLIs */
1715 	if (plchan->at) {
1716 		pl08x_desc_free(&plchan->at->vd);
1717 		plchan->at = NULL;
1718 	}
1719 	/* Dequeue jobs not yet fired as well */
1720 	pl08x_free_txd_list(pl08x, plchan);
1721 
1722 	spin_unlock_irqrestore(&plchan->vc.lock, flags);
1723 
1724 	return 0;
1725 }
1726 
1727 static int pl08x_pause(struct dma_chan *chan)
1728 {
1729 	struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
1730 	unsigned long flags;
1731 
1732 	/*
1733 	 * Anything succeeds on channels with no physical allocation and
1734 	 * no queued transfers.
1735 	 */
1736 	spin_lock_irqsave(&plchan->vc.lock, flags);
1737 	if (!plchan->phychan && !plchan->at) {
1738 		spin_unlock_irqrestore(&plchan->vc.lock, flags);
1739 		return 0;
1740 	}
1741 
1742 	pl08x_pause_phy_chan(plchan->phychan);
1743 	plchan->state = PL08X_CHAN_PAUSED;
1744 
1745 	spin_unlock_irqrestore(&plchan->vc.lock, flags);
1746 
1747 	return 0;
1748 }
1749 
1750 static int pl08x_resume(struct dma_chan *chan)
1751 {
1752 	struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
1753 	unsigned long flags;
1754 
1755 	/*
1756 	 * Anything succeeds on channels with no physical allocation and
1757 	 * no queued transfers.
1758 	 */
1759 	spin_lock_irqsave(&plchan->vc.lock, flags);
1760 	if (!plchan->phychan && !plchan->at) {
1761 		spin_unlock_irqrestore(&plchan->vc.lock, flags);
1762 		return 0;
1763 	}
1764 
1765 	pl08x_resume_phy_chan(plchan->phychan);
1766 	plchan->state = PL08X_CHAN_RUNNING;
1767 
1768 	spin_unlock_irqrestore(&plchan->vc.lock, flags);
1769 
1770 	return 0;
1771 }
1772 
1773 bool pl08x_filter_id(struct dma_chan *chan, void *chan_id)
1774 {
1775 	struct pl08x_dma_chan *plchan;
1776 	char *name = chan_id;
1777 
1778 	/* Reject channels for devices not bound to this driver */
1779 	if (chan->device->dev->driver != &pl08x_amba_driver.drv)
1780 		return false;
1781 
1782 	plchan = to_pl08x_chan(chan);
1783 
1784 	/* Check that the channel is not taken! */
1785 	if (!strcmp(plchan->name, name))
1786 		return true;
1787 
1788 	return false;
1789 }
1790 EXPORT_SYMBOL_GPL(pl08x_filter_id);
1791 
1792 /*
1793  * Just check that the device is there and active
1794  * TODO: turn this bit on/off depending on the number of physical channels
1795  * actually used, if it is zero... well shut it off. That will save some
1796  * power. Cut the clock at the same time.
1797  */
1798 static void pl08x_ensure_on(struct pl08x_driver_data *pl08x)
1799 {
1800 	/* The Nomadik variant does not have the config register */
1801 	if (pl08x->vd->nomadik)
1802 		return;
1803 	writel(PL080_CONFIG_ENABLE, pl08x->base + PL080_CONFIG);
1804 }
1805 
1806 static irqreturn_t pl08x_irq(int irq, void *dev)
1807 {
1808 	struct pl08x_driver_data *pl08x = dev;
1809 	u32 mask = 0, err, tc, i;
1810 
1811 	/* check & clear - ERR & TC interrupts */
1812 	err = readl(pl08x->base + PL080_ERR_STATUS);
1813 	if (err) {
1814 		dev_err(&pl08x->adev->dev, "%s error interrupt, register value 0x%08x\n",
1815 			__func__, err);
1816 		writel(err, pl08x->base + PL080_ERR_CLEAR);
1817 	}
1818 	tc = readl(pl08x->base + PL080_TC_STATUS);
1819 	if (tc)
1820 		writel(tc, pl08x->base + PL080_TC_CLEAR);
1821 
1822 	if (!err && !tc)
1823 		return IRQ_NONE;
1824 
1825 	for (i = 0; i < pl08x->vd->channels; i++) {
1826 		if (((1 << i) & err) || ((1 << i) & tc)) {
1827 			/* Locate physical channel */
1828 			struct pl08x_phy_chan *phychan = &pl08x->phy_chans[i];
1829 			struct pl08x_dma_chan *plchan = phychan->serving;
1830 			struct pl08x_txd *tx;
1831 
1832 			if (!plchan) {
1833 				dev_err(&pl08x->adev->dev,
1834 					"%s Error TC interrupt on unused channel: 0x%08x\n",
1835 					__func__, i);
1836 				continue;
1837 			}
1838 
1839 			spin_lock(&plchan->vc.lock);
1840 			tx = plchan->at;
1841 			if (tx && tx->cyclic) {
1842 				vchan_cyclic_callback(&tx->vd);
1843 			} else if (tx) {
1844 				plchan->at = NULL;
1845 				/*
1846 				 * This descriptor is done, release its mux
1847 				 * reservation.
1848 				 */
1849 				pl08x_release_mux(plchan);
1850 				tx->done = true;
1851 				vchan_cookie_complete(&tx->vd);
1852 
1853 				/*
1854 				 * And start the next descriptor (if any),
1855 				 * otherwise free this channel.
1856 				 */
1857 				if (vchan_next_desc(&plchan->vc))
1858 					pl08x_start_next_txd(plchan);
1859 				else
1860 					pl08x_phy_free(plchan);
1861 			}
1862 			spin_unlock(&plchan->vc.lock);
1863 
1864 			mask |= (1 << i);
1865 		}
1866 	}
1867 
1868 	return mask ? IRQ_HANDLED : IRQ_NONE;
1869 }
1870 
1871 static void pl08x_dma_slave_init(struct pl08x_dma_chan *chan)
1872 {
1873 	chan->slave = true;
1874 	chan->name = chan->cd->bus_id;
1875 	chan->cfg.src_addr = chan->cd->addr;
1876 	chan->cfg.dst_addr = chan->cd->addr;
1877 }
1878 
1879 /*
1880  * Initialise the DMAC memcpy/slave channels.
1881  * Make a local wrapper to hold required data
1882  */
1883 static int pl08x_dma_init_virtual_channels(struct pl08x_driver_data *pl08x,
1884 		struct dma_device *dmadev, unsigned int channels, bool slave)
1885 {
1886 	struct pl08x_dma_chan *chan;
1887 	int i;
1888 
1889 	INIT_LIST_HEAD(&dmadev->channels);
1890 
1891 	/*
1892 	 * Register as many many memcpy as we have physical channels,
1893 	 * we won't always be able to use all but the code will have
1894 	 * to cope with that situation.
1895 	 */
1896 	for (i = 0; i < channels; i++) {
1897 		chan = kzalloc(sizeof(*chan), GFP_KERNEL);
1898 		if (!chan) {
1899 			dev_err(&pl08x->adev->dev,
1900 				"%s no memory for channel\n", __func__);
1901 			return -ENOMEM;
1902 		}
1903 
1904 		chan->host = pl08x;
1905 		chan->state = PL08X_CHAN_IDLE;
1906 		chan->signal = -1;
1907 
1908 		if (slave) {
1909 			chan->cd = &pl08x->pd->slave_channels[i];
1910 			pl08x_dma_slave_init(chan);
1911 		} else {
1912 			chan->cd = &pl08x->pd->memcpy_channel;
1913 			chan->name = kasprintf(GFP_KERNEL, "memcpy%d", i);
1914 			if (!chan->name) {
1915 				kfree(chan);
1916 				return -ENOMEM;
1917 			}
1918 		}
1919 		dev_dbg(&pl08x->adev->dev,
1920 			 "initialize virtual channel \"%s\"\n",
1921 			 chan->name);
1922 
1923 		chan->vc.desc_free = pl08x_desc_free;
1924 		vchan_init(&chan->vc, dmadev);
1925 	}
1926 	dev_info(&pl08x->adev->dev, "initialized %d virtual %s channels\n",
1927 		 i, slave ? "slave" : "memcpy");
1928 	return i;
1929 }
1930 
1931 static void pl08x_free_virtual_channels(struct dma_device *dmadev)
1932 {
1933 	struct pl08x_dma_chan *chan = NULL;
1934 	struct pl08x_dma_chan *next;
1935 
1936 	list_for_each_entry_safe(chan,
1937 				 next, &dmadev->channels, vc.chan.device_node) {
1938 		list_del(&chan->vc.chan.device_node);
1939 		kfree(chan);
1940 	}
1941 }
1942 
1943 #ifdef CONFIG_DEBUG_FS
1944 static const char *pl08x_state_str(enum pl08x_dma_chan_state state)
1945 {
1946 	switch (state) {
1947 	case PL08X_CHAN_IDLE:
1948 		return "idle";
1949 	case PL08X_CHAN_RUNNING:
1950 		return "running";
1951 	case PL08X_CHAN_PAUSED:
1952 		return "paused";
1953 	case PL08X_CHAN_WAITING:
1954 		return "waiting";
1955 	default:
1956 		break;
1957 	}
1958 	return "UNKNOWN STATE";
1959 }
1960 
1961 static int pl08x_debugfs_show(struct seq_file *s, void *data)
1962 {
1963 	struct pl08x_driver_data *pl08x = s->private;
1964 	struct pl08x_dma_chan *chan;
1965 	struct pl08x_phy_chan *ch;
1966 	unsigned long flags;
1967 	int i;
1968 
1969 	seq_printf(s, "PL08x physical channels:\n");
1970 	seq_printf(s, "CHANNEL:\tUSER:\n");
1971 	seq_printf(s, "--------\t-----\n");
1972 	for (i = 0; i < pl08x->vd->channels; i++) {
1973 		struct pl08x_dma_chan *virt_chan;
1974 
1975 		ch = &pl08x->phy_chans[i];
1976 
1977 		spin_lock_irqsave(&ch->lock, flags);
1978 		virt_chan = ch->serving;
1979 
1980 		seq_printf(s, "%d\t\t%s%s\n",
1981 			   ch->id,
1982 			   virt_chan ? virt_chan->name : "(none)",
1983 			   ch->locked ? " LOCKED" : "");
1984 
1985 		spin_unlock_irqrestore(&ch->lock, flags);
1986 	}
1987 
1988 	seq_printf(s, "\nPL08x virtual memcpy channels:\n");
1989 	seq_printf(s, "CHANNEL:\tSTATE:\n");
1990 	seq_printf(s, "--------\t------\n");
1991 	list_for_each_entry(chan, &pl08x->memcpy.channels, vc.chan.device_node) {
1992 		seq_printf(s, "%s\t\t%s\n", chan->name,
1993 			   pl08x_state_str(chan->state));
1994 	}
1995 
1996 	seq_printf(s, "\nPL08x virtual slave channels:\n");
1997 	seq_printf(s, "CHANNEL:\tSTATE:\n");
1998 	seq_printf(s, "--------\t------\n");
1999 	list_for_each_entry(chan, &pl08x->slave.channels, vc.chan.device_node) {
2000 		seq_printf(s, "%s\t\t%s\n", chan->name,
2001 			   pl08x_state_str(chan->state));
2002 	}
2003 
2004 	return 0;
2005 }
2006 
2007 static int pl08x_debugfs_open(struct inode *inode, struct file *file)
2008 {
2009 	return single_open(file, pl08x_debugfs_show, inode->i_private);
2010 }
2011 
2012 static const struct file_operations pl08x_debugfs_operations = {
2013 	.open		= pl08x_debugfs_open,
2014 	.read		= seq_read,
2015 	.llseek		= seq_lseek,
2016 	.release	= single_release,
2017 };
2018 
2019 static void init_pl08x_debugfs(struct pl08x_driver_data *pl08x)
2020 {
2021 	/* Expose a simple debugfs interface to view all clocks */
2022 	(void) debugfs_create_file(dev_name(&pl08x->adev->dev),
2023 			S_IFREG | S_IRUGO, NULL, pl08x,
2024 			&pl08x_debugfs_operations);
2025 }
2026 
2027 #else
2028 static inline void init_pl08x_debugfs(struct pl08x_driver_data *pl08x)
2029 {
2030 }
2031 #endif
2032 
2033 static int pl08x_probe(struct amba_device *adev, const struct amba_id *id)
2034 {
2035 	struct pl08x_driver_data *pl08x;
2036 	const struct vendor_data *vd = id->data;
2037 	u32 tsfr_size;
2038 	int ret = 0;
2039 	int i;
2040 
2041 	ret = amba_request_regions(adev, NULL);
2042 	if (ret)
2043 		return ret;
2044 
2045 	/* Ensure that we can do DMA */
2046 	ret = dma_set_mask_and_coherent(&adev->dev, DMA_BIT_MASK(32));
2047 	if (ret)
2048 		goto out_no_pl08x;
2049 
2050 	/* Create the driver state holder */
2051 	pl08x = kzalloc(sizeof(*pl08x), GFP_KERNEL);
2052 	if (!pl08x) {
2053 		ret = -ENOMEM;
2054 		goto out_no_pl08x;
2055 	}
2056 
2057 	/* Initialize memcpy engine */
2058 	dma_cap_set(DMA_MEMCPY, pl08x->memcpy.cap_mask);
2059 	pl08x->memcpy.dev = &adev->dev;
2060 	pl08x->memcpy.device_free_chan_resources = pl08x_free_chan_resources;
2061 	pl08x->memcpy.device_prep_dma_memcpy = pl08x_prep_dma_memcpy;
2062 	pl08x->memcpy.device_prep_dma_interrupt = pl08x_prep_dma_interrupt;
2063 	pl08x->memcpy.device_tx_status = pl08x_dma_tx_status;
2064 	pl08x->memcpy.device_issue_pending = pl08x_issue_pending;
2065 	pl08x->memcpy.device_config = pl08x_config;
2066 	pl08x->memcpy.device_pause = pl08x_pause;
2067 	pl08x->memcpy.device_resume = pl08x_resume;
2068 	pl08x->memcpy.device_terminate_all = pl08x_terminate_all;
2069 	pl08x->memcpy.src_addr_widths = PL80X_DMA_BUSWIDTHS;
2070 	pl08x->memcpy.dst_addr_widths = PL80X_DMA_BUSWIDTHS;
2071 	pl08x->memcpy.directions = BIT(DMA_MEM_TO_MEM);
2072 	pl08x->memcpy.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
2073 
2074 	/* Initialize slave engine */
2075 	dma_cap_set(DMA_SLAVE, pl08x->slave.cap_mask);
2076 	dma_cap_set(DMA_CYCLIC, pl08x->slave.cap_mask);
2077 	pl08x->slave.dev = &adev->dev;
2078 	pl08x->slave.device_free_chan_resources = pl08x_free_chan_resources;
2079 	pl08x->slave.device_prep_dma_interrupt = pl08x_prep_dma_interrupt;
2080 	pl08x->slave.device_tx_status = pl08x_dma_tx_status;
2081 	pl08x->slave.device_issue_pending = pl08x_issue_pending;
2082 	pl08x->slave.device_prep_slave_sg = pl08x_prep_slave_sg;
2083 	pl08x->slave.device_prep_dma_cyclic = pl08x_prep_dma_cyclic;
2084 	pl08x->slave.device_config = pl08x_config;
2085 	pl08x->slave.device_pause = pl08x_pause;
2086 	pl08x->slave.device_resume = pl08x_resume;
2087 	pl08x->slave.device_terminate_all = pl08x_terminate_all;
2088 	pl08x->slave.src_addr_widths = PL80X_DMA_BUSWIDTHS;
2089 	pl08x->slave.dst_addr_widths = PL80X_DMA_BUSWIDTHS;
2090 	pl08x->slave.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
2091 	pl08x->slave.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
2092 
2093 	/* Get the platform data */
2094 	pl08x->pd = dev_get_platdata(&adev->dev);
2095 	if (!pl08x->pd) {
2096 		dev_err(&adev->dev, "no platform data supplied\n");
2097 		ret = -EINVAL;
2098 		goto out_no_platdata;
2099 	}
2100 
2101 	/* Assign useful pointers to the driver state */
2102 	pl08x->adev = adev;
2103 	pl08x->vd = vd;
2104 
2105 	/* By default, AHB1 only.  If dualmaster, from platform */
2106 	pl08x->lli_buses = PL08X_AHB1;
2107 	pl08x->mem_buses = PL08X_AHB1;
2108 	if (pl08x->vd->dualmaster) {
2109 		pl08x->lli_buses = pl08x->pd->lli_buses;
2110 		pl08x->mem_buses = pl08x->pd->mem_buses;
2111 	}
2112 
2113 	if (vd->pl080s)
2114 		pl08x->lli_words = PL080S_LLI_WORDS;
2115 	else
2116 		pl08x->lli_words = PL080_LLI_WORDS;
2117 	tsfr_size = MAX_NUM_TSFR_LLIS * pl08x->lli_words * sizeof(u32);
2118 
2119 	/* A DMA memory pool for LLIs, align on 1-byte boundary */
2120 	pl08x->pool = dma_pool_create(DRIVER_NAME, &pl08x->adev->dev,
2121 						tsfr_size, PL08X_ALIGN, 0);
2122 	if (!pl08x->pool) {
2123 		ret = -ENOMEM;
2124 		goto out_no_lli_pool;
2125 	}
2126 
2127 	pl08x->base = ioremap(adev->res.start, resource_size(&adev->res));
2128 	if (!pl08x->base) {
2129 		ret = -ENOMEM;
2130 		goto out_no_ioremap;
2131 	}
2132 
2133 	/* Turn on the PL08x */
2134 	pl08x_ensure_on(pl08x);
2135 
2136 	/* Attach the interrupt handler */
2137 	writel(0x000000FF, pl08x->base + PL080_ERR_CLEAR);
2138 	writel(0x000000FF, pl08x->base + PL080_TC_CLEAR);
2139 
2140 	ret = request_irq(adev->irq[0], pl08x_irq, 0, DRIVER_NAME, pl08x);
2141 	if (ret) {
2142 		dev_err(&adev->dev, "%s failed to request interrupt %d\n",
2143 			__func__, adev->irq[0]);
2144 		goto out_no_irq;
2145 	}
2146 
2147 	/* Initialize physical channels */
2148 	pl08x->phy_chans = kzalloc((vd->channels * sizeof(*pl08x->phy_chans)),
2149 			GFP_KERNEL);
2150 	if (!pl08x->phy_chans) {
2151 		dev_err(&adev->dev, "%s failed to allocate "
2152 			"physical channel holders\n",
2153 			__func__);
2154 		ret = -ENOMEM;
2155 		goto out_no_phychans;
2156 	}
2157 
2158 	for (i = 0; i < vd->channels; i++) {
2159 		struct pl08x_phy_chan *ch = &pl08x->phy_chans[i];
2160 
2161 		ch->id = i;
2162 		ch->base = pl08x->base + PL080_Cx_BASE(i);
2163 		ch->reg_config = ch->base + vd->config_offset;
2164 		spin_lock_init(&ch->lock);
2165 
2166 		/*
2167 		 * Nomadik variants can have channels that are locked
2168 		 * down for the secure world only. Lock up these channels
2169 		 * by perpetually serving a dummy virtual channel.
2170 		 */
2171 		if (vd->nomadik) {
2172 			u32 val;
2173 
2174 			val = readl(ch->reg_config);
2175 			if (val & (PL080N_CONFIG_ITPROT | PL080N_CONFIG_SECPROT)) {
2176 				dev_info(&adev->dev, "physical channel %d reserved for secure access only\n", i);
2177 				ch->locked = true;
2178 			}
2179 		}
2180 
2181 		dev_dbg(&adev->dev, "physical channel %d is %s\n",
2182 			i, pl08x_phy_channel_busy(ch) ? "BUSY" : "FREE");
2183 	}
2184 
2185 	/* Register as many memcpy channels as there are physical channels */
2186 	ret = pl08x_dma_init_virtual_channels(pl08x, &pl08x->memcpy,
2187 					      pl08x->vd->channels, false);
2188 	if (ret <= 0) {
2189 		dev_warn(&pl08x->adev->dev,
2190 			 "%s failed to enumerate memcpy channels - %d\n",
2191 			 __func__, ret);
2192 		goto out_no_memcpy;
2193 	}
2194 
2195 	/* Register slave channels */
2196 	ret = pl08x_dma_init_virtual_channels(pl08x, &pl08x->slave,
2197 			pl08x->pd->num_slave_channels, true);
2198 	if (ret < 0) {
2199 		dev_warn(&pl08x->adev->dev,
2200 			"%s failed to enumerate slave channels - %d\n",
2201 				__func__, ret);
2202 		goto out_no_slave;
2203 	}
2204 
2205 	ret = dma_async_device_register(&pl08x->memcpy);
2206 	if (ret) {
2207 		dev_warn(&pl08x->adev->dev,
2208 			"%s failed to register memcpy as an async device - %d\n",
2209 			__func__, ret);
2210 		goto out_no_memcpy_reg;
2211 	}
2212 
2213 	ret = dma_async_device_register(&pl08x->slave);
2214 	if (ret) {
2215 		dev_warn(&pl08x->adev->dev,
2216 			"%s failed to register slave as an async device - %d\n",
2217 			__func__, ret);
2218 		goto out_no_slave_reg;
2219 	}
2220 
2221 	amba_set_drvdata(adev, pl08x);
2222 	init_pl08x_debugfs(pl08x);
2223 	dev_info(&pl08x->adev->dev, "DMA: PL%03x%s rev%u at 0x%08llx irq %d\n",
2224 		 amba_part(adev), pl08x->vd->pl080s ? "s" : "", amba_rev(adev),
2225 		 (unsigned long long)adev->res.start, adev->irq[0]);
2226 
2227 	return 0;
2228 
2229 out_no_slave_reg:
2230 	dma_async_device_unregister(&pl08x->memcpy);
2231 out_no_memcpy_reg:
2232 	pl08x_free_virtual_channels(&pl08x->slave);
2233 out_no_slave:
2234 	pl08x_free_virtual_channels(&pl08x->memcpy);
2235 out_no_memcpy:
2236 	kfree(pl08x->phy_chans);
2237 out_no_phychans:
2238 	free_irq(adev->irq[0], pl08x);
2239 out_no_irq:
2240 	iounmap(pl08x->base);
2241 out_no_ioremap:
2242 	dma_pool_destroy(pl08x->pool);
2243 out_no_lli_pool:
2244 out_no_platdata:
2245 	kfree(pl08x);
2246 out_no_pl08x:
2247 	amba_release_regions(adev);
2248 	return ret;
2249 }
2250 
2251 /* PL080 has 8 channels and the PL080 have just 2 */
2252 static struct vendor_data vendor_pl080 = {
2253 	.config_offset = PL080_CH_CONFIG,
2254 	.channels = 8,
2255 	.dualmaster = true,
2256 	.max_transfer_size = PL080_CONTROL_TRANSFER_SIZE_MASK,
2257 };
2258 
2259 static struct vendor_data vendor_nomadik = {
2260 	.config_offset = PL080_CH_CONFIG,
2261 	.channels = 8,
2262 	.dualmaster = true,
2263 	.nomadik = true,
2264 	.max_transfer_size = PL080_CONTROL_TRANSFER_SIZE_MASK,
2265 };
2266 
2267 static struct vendor_data vendor_pl080s = {
2268 	.config_offset = PL080S_CH_CONFIG,
2269 	.channels = 8,
2270 	.pl080s = true,
2271 	.max_transfer_size = PL080S_CONTROL_TRANSFER_SIZE_MASK,
2272 };
2273 
2274 static struct vendor_data vendor_pl081 = {
2275 	.config_offset = PL080_CH_CONFIG,
2276 	.channels = 2,
2277 	.dualmaster = false,
2278 	.max_transfer_size = PL080_CONTROL_TRANSFER_SIZE_MASK,
2279 };
2280 
2281 static struct amba_id pl08x_ids[] = {
2282 	/* Samsung PL080S variant */
2283 	{
2284 		.id	= 0x0a141080,
2285 		.mask	= 0xffffffff,
2286 		.data	= &vendor_pl080s,
2287 	},
2288 	/* PL080 */
2289 	{
2290 		.id	= 0x00041080,
2291 		.mask	= 0x000fffff,
2292 		.data	= &vendor_pl080,
2293 	},
2294 	/* PL081 */
2295 	{
2296 		.id	= 0x00041081,
2297 		.mask	= 0x000fffff,
2298 		.data	= &vendor_pl081,
2299 	},
2300 	/* Nomadik 8815 PL080 variant */
2301 	{
2302 		.id	= 0x00280080,
2303 		.mask	= 0x00ffffff,
2304 		.data	= &vendor_nomadik,
2305 	},
2306 	{ 0, 0 },
2307 };
2308 
2309 MODULE_DEVICE_TABLE(amba, pl08x_ids);
2310 
2311 static struct amba_driver pl08x_amba_driver = {
2312 	.drv.name	= DRIVER_NAME,
2313 	.id_table	= pl08x_ids,
2314 	.probe		= pl08x_probe,
2315 };
2316 
2317 static int __init pl08x_init(void)
2318 {
2319 	int retval;
2320 	retval = amba_driver_register(&pl08x_amba_driver);
2321 	if (retval)
2322 		printk(KERN_WARNING DRIVER_NAME
2323 		       "failed to register as an AMBA device (%d)\n",
2324 		       retval);
2325 	return retval;
2326 }
2327 subsys_initcall(pl08x_init);
2328