1/*
2 * Copyright (C) 2013-2014 Renesas Electronics Europe Ltd.
3 * Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of version 2 of the GNU General Public License as
7 * published by the Free Software Foundation.
8 */
9
10#include <linux/bitmap.h>
11#include <linux/bitops.h>
12#include <linux/clk.h>
13#include <linux/dma-mapping.h>
14#include <linux/dmaengine.h>
15#include <linux/err.h>
16#include <linux/interrupt.h>
17#include <linux/io.h>
18#include <linux/log2.h>
19#include <linux/module.h>
20#include <linux/of.h>
21#include <linux/of_device.h>
22#include <linux/of_dma.h>
23#include <linux/platform_device.h>
24#include <linux/slab.h>
25
26#include <dt-bindings/dma/nbpfaxi.h>
27
28#include "dmaengine.h"
29
30#define NBPF_REG_CHAN_OFFSET	0
31#define NBPF_REG_CHAN_SIZE	0x40
32
33/* Channel Current Transaction Byte register */
34#define NBPF_CHAN_CUR_TR_BYTE	0x20
35
36/* Channel Status register */
37#define NBPF_CHAN_STAT	0x24
38#define NBPF_CHAN_STAT_EN	1
39#define NBPF_CHAN_STAT_TACT	4
40#define NBPF_CHAN_STAT_ERR	0x10
41#define NBPF_CHAN_STAT_END	0x20
42#define NBPF_CHAN_STAT_TC	0x40
43#define NBPF_CHAN_STAT_DER	0x400
44
45/* Channel Control register */
46#define NBPF_CHAN_CTRL	0x28
47#define NBPF_CHAN_CTRL_SETEN	1
48#define NBPF_CHAN_CTRL_CLREN	2
49#define NBPF_CHAN_CTRL_STG	4
50#define NBPF_CHAN_CTRL_SWRST	8
51#define NBPF_CHAN_CTRL_CLRRQ	0x10
52#define NBPF_CHAN_CTRL_CLREND	0x20
53#define NBPF_CHAN_CTRL_CLRTC	0x40
54#define NBPF_CHAN_CTRL_SETSUS	0x100
55#define NBPF_CHAN_CTRL_CLRSUS	0x200
56
57/* Channel Configuration register */
58#define NBPF_CHAN_CFG	0x2c
59#define NBPF_CHAN_CFG_SEL	7		/* terminal SELect: 0..7 */
60#define NBPF_CHAN_CFG_REQD	8		/* REQuest Direction: DMAREQ is 0: input, 1: output */
61#define NBPF_CHAN_CFG_LOEN	0x10		/* LOw ENable: low DMA request line is: 0: inactive, 1: active */
62#define NBPF_CHAN_CFG_HIEN	0x20		/* HIgh ENable: high DMA request line is: 0: inactive, 1: active */
63#define NBPF_CHAN_CFG_LVL	0x40		/* LeVeL: DMA request line is sensed as 0: edge, 1: level */
64#define NBPF_CHAN_CFG_AM	0x700		/* ACK Mode: 0: Pulse mode, 1: Level mode, b'1x: Bus Cycle */
65#define NBPF_CHAN_CFG_SDS	0xf000		/* Source Data Size: 0: 8 bits,... , 7: 1024 bits */
66#define NBPF_CHAN_CFG_DDS	0xf0000		/* Destination Data Size: as above */
67#define NBPF_CHAN_CFG_SAD	0x100000	/* Source ADdress counting: 0: increment, 1: fixed */
68#define NBPF_CHAN_CFG_DAD	0x200000	/* Destination ADdress counting: 0: increment, 1: fixed */
69#define NBPF_CHAN_CFG_TM	0x400000	/* Transfer Mode: 0: single, 1: block TM */
70#define NBPF_CHAN_CFG_DEM	0x1000000	/* DMAEND interrupt Mask */
71#define NBPF_CHAN_CFG_TCM	0x2000000	/* DMATCO interrupt Mask */
72#define NBPF_CHAN_CFG_SBE	0x8000000	/* Sweep Buffer Enable */
73#define NBPF_CHAN_CFG_RSEL	0x10000000	/* RM: Register Set sELect */
74#define NBPF_CHAN_CFG_RSW	0x20000000	/* RM: Register Select sWitch */
75#define NBPF_CHAN_CFG_REN	0x40000000	/* RM: Register Set Enable */
76#define NBPF_CHAN_CFG_DMS	0x80000000	/* 0: register mode (RM), 1: link mode (LM) */
77
78#define NBPF_CHAN_NXLA	0x38
79#define NBPF_CHAN_CRLA	0x3c
80
81/* Link Header field */
82#define NBPF_HEADER_LV	1
83#define NBPF_HEADER_LE	2
84#define NBPF_HEADER_WBD	4
85#define NBPF_HEADER_DIM	8
86
87#define NBPF_CTRL	0x300
88#define NBPF_CTRL_PR	1		/* 0: fixed priority, 1: round robin */
89#define NBPF_CTRL_LVINT	2		/* DMAEND and DMAERR signalling: 0: pulse, 1: level */
90
91#define NBPF_DSTAT_ER	0x314
92#define NBPF_DSTAT_END	0x318
93
94#define NBPF_DMA_BUSWIDTHS \
95	(BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) | \
96	 BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
97	 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
98	 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \
99	 BIT(DMA_SLAVE_BUSWIDTH_8_BYTES))
100
101struct nbpf_config {
102	int num_channels;
103	int buffer_size;
104};
105
106/*
107 * We've got 3 types of objects, used to describe DMA transfers:
108 * 1. high-level descriptor, containing a struct dma_async_tx_descriptor object
109 *	in it, used to communicate with the user
110 * 2. hardware DMA link descriptors, that we pass to DMAC for DMA transfer
111 *	queuing, these must be DMAable, using either the streaming DMA API or
112 *	allocated from coherent memory - one per SG segment
113 * 3. one per SG segment descriptors, used to manage HW link descriptors from
114 *	(2). They do not have to be DMAable. They can either be (a) allocated
115 *	together with link descriptors as mixed (DMA / CPU) objects, or (b)
116 *	separately. Even if allocated separately it would be best to link them
117 *	to link descriptors once during channel resource allocation and always
118 *	use them as a single object.
119 * Therefore for both cases (a) and (b) at run-time objects (2) and (3) shall be
120 * treated as a single SG segment descriptor.
121 */
122
123struct nbpf_link_reg {
124	u32	header;
125	u32	src_addr;
126	u32	dst_addr;
127	u32	transaction_size;
128	u32	config;
129	u32	interval;
130	u32	extension;
131	u32	next;
132} __packed;
133
134struct nbpf_device;
135struct nbpf_channel;
136struct nbpf_desc;
137
138struct nbpf_link_desc {
139	struct nbpf_link_reg *hwdesc;
140	dma_addr_t hwdesc_dma_addr;
141	struct nbpf_desc *desc;
142	struct list_head node;
143};
144
145/**
146 * struct nbpf_desc - DMA transfer descriptor
147 * @async_tx:	dmaengine object
148 * @user_wait:	waiting for a user ack
149 * @length:	total transfer length
150 * @sg:		list of hardware descriptors, represented by struct nbpf_link_desc
151 * @node:	member in channel descriptor lists
152 */
153struct nbpf_desc {
154	struct dma_async_tx_descriptor async_tx;
155	bool user_wait;
156	size_t length;
157	struct nbpf_channel *chan;
158	struct list_head sg;
159	struct list_head node;
160};
161
162/* Take a wild guess: allocate 4 segments per descriptor */
163#define NBPF_SEGMENTS_PER_DESC 4
164#define NBPF_DESCS_PER_PAGE ((PAGE_SIZE - sizeof(struct list_head)) /	\
165	(sizeof(struct nbpf_desc) +					\
166	 NBPF_SEGMENTS_PER_DESC *					\
167	 (sizeof(struct nbpf_link_desc) + sizeof(struct nbpf_link_reg))))
168#define NBPF_SEGMENTS_PER_PAGE (NBPF_SEGMENTS_PER_DESC * NBPF_DESCS_PER_PAGE)
169
170struct nbpf_desc_page {
171	struct list_head node;
172	struct nbpf_desc desc[NBPF_DESCS_PER_PAGE];
173	struct nbpf_link_desc ldesc[NBPF_SEGMENTS_PER_PAGE];
174	struct nbpf_link_reg hwdesc[NBPF_SEGMENTS_PER_PAGE];
175};
176
177/**
178 * struct nbpf_channel - one DMAC channel
179 * @dma_chan:	standard dmaengine channel object
180 * @base:	register address base
181 * @nbpf:	DMAC
182 * @name:	IRQ name
183 * @irq:	IRQ number
184 * @slave_addr:	address for slave DMA
185 * @slave_width:slave data size in bytes
186 * @slave_burst:maximum slave burst size in bytes
187 * @terminal:	DMA terminal, assigned to this channel
188 * @dmarq_cfg:	DMA request line configuration - high / low, edge / level for NBPF_CHAN_CFG
189 * @flags:	configuration flags from DT
190 * @lock:	protect descriptor lists
191 * @free_links:	list of free link descriptors
192 * @free:	list of free descriptors
193 * @queued:	list of queued descriptors
194 * @active:	list of descriptors, scheduled for processing
195 * @done:	list of completed descriptors, waiting post-processing
196 * @desc_page:	list of additionally allocated descriptor pages - if any
197 */
198struct nbpf_channel {
199	struct dma_chan dma_chan;
200	struct tasklet_struct tasklet;
201	void __iomem *base;
202	struct nbpf_device *nbpf;
203	char name[16];
204	int irq;
205	dma_addr_t slave_src_addr;
206	size_t slave_src_width;
207	size_t slave_src_burst;
208	dma_addr_t slave_dst_addr;
209	size_t slave_dst_width;
210	size_t slave_dst_burst;
211	unsigned int terminal;
212	u32 dmarq_cfg;
213	unsigned long flags;
214	spinlock_t lock;
215	struct list_head free_links;
216	struct list_head free;
217	struct list_head queued;
218	struct list_head active;
219	struct list_head done;
220	struct list_head desc_page;
221	struct nbpf_desc *running;
222	bool paused;
223};
224
225struct nbpf_device {
226	struct dma_device dma_dev;
227	void __iomem *base;
228	struct clk *clk;
229	const struct nbpf_config *config;
230	struct nbpf_channel chan[];
231};
232
233enum nbpf_model {
234	NBPF1B4,
235	NBPF1B8,
236	NBPF1B16,
237	NBPF4B4,
238	NBPF4B8,
239	NBPF4B16,
240	NBPF8B4,
241	NBPF8B8,
242	NBPF8B16,
243};
244
245static struct nbpf_config nbpf_cfg[] = {
246	[NBPF1B4] = {
247		.num_channels = 1,
248		.buffer_size = 4,
249	},
250	[NBPF1B8] = {
251		.num_channels = 1,
252		.buffer_size = 8,
253	},
254	[NBPF1B16] = {
255		.num_channels = 1,
256		.buffer_size = 16,
257	},
258	[NBPF4B4] = {
259		.num_channels = 4,
260		.buffer_size = 4,
261	},
262	[NBPF4B8] = {
263		.num_channels = 4,
264		.buffer_size = 8,
265	},
266	[NBPF4B16] = {
267		.num_channels = 4,
268		.buffer_size = 16,
269	},
270	[NBPF8B4] = {
271		.num_channels = 8,
272		.buffer_size = 4,
273	},
274	[NBPF8B8] = {
275		.num_channels = 8,
276		.buffer_size = 8,
277	},
278	[NBPF8B16] = {
279		.num_channels = 8,
280		.buffer_size = 16,
281	},
282};
283
284#define nbpf_to_chan(d) container_of(d, struct nbpf_channel, dma_chan)
285
286/*
287 * dmaengine drivers seem to have a lot in common and instead of sharing more
288 * code, they reimplement those common algorithms independently. In this driver
289 * we try to separate the hardware-specific part from the (largely) generic
290 * part. This improves code readability and makes it possible in the future to
291 * reuse the generic code in form of a helper library. That generic code should
292 * be suitable for various DMA controllers, using transfer descriptors in RAM
293 * and pushing one SG list at a time to the DMA controller.
294 */
295
296/*		Hardware-specific part		*/
297
298static inline u32 nbpf_chan_read(struct nbpf_channel *chan,
299				 unsigned int offset)
300{
301	u32 data = ioread32(chan->base + offset);
302	dev_dbg(chan->dma_chan.device->dev, "%s(0x%p + 0x%x) = 0x%x\n",
303		__func__, chan->base, offset, data);
304	return data;
305}
306
307static inline void nbpf_chan_write(struct nbpf_channel *chan,
308				   unsigned int offset, u32 data)
309{
310	iowrite32(data, chan->base + offset);
311	dev_dbg(chan->dma_chan.device->dev, "%s(0x%p + 0x%x) = 0x%x\n",
312		__func__, chan->base, offset, data);
313}
314
315static inline u32 nbpf_read(struct nbpf_device *nbpf,
316			    unsigned int offset)
317{
318	u32 data = ioread32(nbpf->base + offset);
319	dev_dbg(nbpf->dma_dev.dev, "%s(0x%p + 0x%x) = 0x%x\n",
320		__func__, nbpf->base, offset, data);
321	return data;
322}
323
324static inline void nbpf_write(struct nbpf_device *nbpf,
325			      unsigned int offset, u32 data)
326{
327	iowrite32(data, nbpf->base + offset);
328	dev_dbg(nbpf->dma_dev.dev, "%s(0x%p + 0x%x) = 0x%x\n",
329		__func__, nbpf->base, offset, data);
330}
331
332static void nbpf_chan_halt(struct nbpf_channel *chan)
333{
334	nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_CLREN);
335}
336
337static bool nbpf_status_get(struct nbpf_channel *chan)
338{
339	u32 status = nbpf_read(chan->nbpf, NBPF_DSTAT_END);
340
341	return status & BIT(chan - chan->nbpf->chan);
342}
343
344static void nbpf_status_ack(struct nbpf_channel *chan)
345{
346	nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_CLREND);
347}
348
349static u32 nbpf_error_get(struct nbpf_device *nbpf)
350{
351	return nbpf_read(nbpf, NBPF_DSTAT_ER);
352}
353
354static struct nbpf_channel *nbpf_error_get_channel(struct nbpf_device *nbpf, u32 error)
355{
356	return nbpf->chan + __ffs(error);
357}
358
359static void nbpf_error_clear(struct nbpf_channel *chan)
360{
361	u32 status;
362	int i;
363
364	/* Stop the channel, make sure DMA has been aborted */
365	nbpf_chan_halt(chan);
366
367	for (i = 1000; i; i--) {
368		status = nbpf_chan_read(chan, NBPF_CHAN_STAT);
369		if (!(status & NBPF_CHAN_STAT_TACT))
370			break;
371		cpu_relax();
372	}
373
374	if (!i)
375		dev_err(chan->dma_chan.device->dev,
376			"%s(): abort timeout, channel status 0x%x\n", __func__, status);
377
378	nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_SWRST);
379}
380
381static int nbpf_start(struct nbpf_desc *desc)
382{
383	struct nbpf_channel *chan = desc->chan;
384	struct nbpf_link_desc *ldesc = list_first_entry(&desc->sg, struct nbpf_link_desc, node);
385
386	nbpf_chan_write(chan, NBPF_CHAN_NXLA, (u32)ldesc->hwdesc_dma_addr);
387	nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_SETEN | NBPF_CHAN_CTRL_CLRSUS);
388	chan->paused = false;
389
390	/* Software trigger MEMCPY - only MEMCPY uses the block mode */
391	if (ldesc->hwdesc->config & NBPF_CHAN_CFG_TM)
392		nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_STG);
393
394	dev_dbg(chan->nbpf->dma_dev.dev, "%s(): next 0x%x, cur 0x%x\n", __func__,
395		nbpf_chan_read(chan, NBPF_CHAN_NXLA), nbpf_chan_read(chan, NBPF_CHAN_CRLA));
396
397	return 0;
398}
399
400static void nbpf_chan_prepare(struct nbpf_channel *chan)
401{
402	chan->dmarq_cfg = (chan->flags & NBPF_SLAVE_RQ_HIGH ? NBPF_CHAN_CFG_HIEN : 0) |
403		(chan->flags & NBPF_SLAVE_RQ_LOW ? NBPF_CHAN_CFG_LOEN : 0) |
404		(chan->flags & NBPF_SLAVE_RQ_LEVEL ?
405		 NBPF_CHAN_CFG_LVL | (NBPF_CHAN_CFG_AM & 0x200) : 0) |
406		chan->terminal;
407}
408
409static void nbpf_chan_prepare_default(struct nbpf_channel *chan)
410{
411	/* Don't output DMAACK */
412	chan->dmarq_cfg = NBPF_CHAN_CFG_AM & 0x400;
413	chan->terminal = 0;
414	chan->flags = 0;
415}
416
417static void nbpf_chan_configure(struct nbpf_channel *chan)
418{
419	/*
420	 * We assume, that only the link mode and DMA request line configuration
421	 * have to be set in the configuration register manually. Dynamic
422	 * per-transfer configuration will be loaded from transfer descriptors.
423	 */
424	nbpf_chan_write(chan, NBPF_CHAN_CFG, NBPF_CHAN_CFG_DMS | chan->dmarq_cfg);
425}
426
427static u32 nbpf_xfer_ds(struct nbpf_device *nbpf, size_t size)
428{
429	/* Maximum supported bursts depend on the buffer size */
430	return min_t(int, __ffs(size), ilog2(nbpf->config->buffer_size * 8));
431}
432
433static size_t nbpf_xfer_size(struct nbpf_device *nbpf,
434			     enum dma_slave_buswidth width, u32 burst)
435{
436	size_t size;
437
438	if (!burst)
439		burst = 1;
440
441	switch (width) {
442	case DMA_SLAVE_BUSWIDTH_8_BYTES:
443		size = 8 * burst;
444		break;
445
446	case DMA_SLAVE_BUSWIDTH_4_BYTES:
447		size = 4 * burst;
448		break;
449
450	case DMA_SLAVE_BUSWIDTH_2_BYTES:
451		size = 2 * burst;
452		break;
453
454	default:
455		pr_warn("%s(): invalid bus width %u\n", __func__, width);
456	case DMA_SLAVE_BUSWIDTH_1_BYTE:
457		size = burst;
458	}
459
460	return nbpf_xfer_ds(nbpf, size);
461}
462
463/*
464 * We need a way to recognise slaves, whose data is sent "raw" over the bus,
465 * i.e. it isn't known in advance how many bytes will be received. Therefore
466 * the slave driver has to provide a "large enough" buffer and either read the
467 * buffer, when it is full, or detect, that some data has arrived, then wait for
468 * a timeout, if no more data arrives - receive what's already there. We want to
469 * handle such slaves in a special way to allow an optimised mode for other
470 * users, for whom the amount of data is known in advance. So far there's no way
471 * to recognise such slaves. We use a data-width check to distinguish between
472 * the SD host and the PL011 UART.
473 */
474
475static int nbpf_prep_one(struct nbpf_link_desc *ldesc,
476			 enum dma_transfer_direction direction,
477			 dma_addr_t src, dma_addr_t dst, size_t size, bool last)
478{
479	struct nbpf_link_reg *hwdesc = ldesc->hwdesc;
480	struct nbpf_desc *desc = ldesc->desc;
481	struct nbpf_channel *chan = desc->chan;
482	struct device *dev = chan->dma_chan.device->dev;
483	size_t mem_xfer, slave_xfer;
484	bool can_burst;
485
486	hwdesc->header = NBPF_HEADER_WBD | NBPF_HEADER_LV |
487		(last ? NBPF_HEADER_LE : 0);
488
489	hwdesc->src_addr = src;
490	hwdesc->dst_addr = dst;
491	hwdesc->transaction_size = size;
492
493	/*
494	 * set config: SAD, DAD, DDS, SDS, etc.
495	 * Note on transfer sizes: the DMAC can perform unaligned DMA transfers,
496	 * but it is important to have transaction size a multiple of both
497	 * receiver and transmitter transfer sizes. It is also possible to use
498	 * different RAM and device transfer sizes, and it does work well with
499	 * some devices, e.g. with V08R07S01E SD host controllers, which can use
500	 * 128 byte transfers. But this doesn't work with other devices,
501	 * especially when the transaction size is unknown. This is the case,
502	 * e.g. with serial drivers like amba-pl011.c. For reception it sets up
503	 * the transaction size of 4K and if fewer bytes are received, it
504	 * pauses DMA and reads out data received via DMA as well as those left
505	 * in the Rx FIFO. For this to work with the RAM side using burst
506	 * transfers we enable the SBE bit and terminate the transfer in our
507	 * .device_pause handler.
508	 */
509	mem_xfer = nbpf_xfer_ds(chan->nbpf, size);
510
511	switch (direction) {
512	case DMA_DEV_TO_MEM:
513		can_burst = chan->slave_src_width >= 3;
514		slave_xfer = min(mem_xfer, can_burst ?
515				 chan->slave_src_burst : chan->slave_src_width);
516		/*
517		 * Is the slave narrower than 64 bits, i.e. isn't using the full
518		 * bus width and cannot use bursts?
519		 */
520		if (mem_xfer > chan->slave_src_burst && !can_burst)
521			mem_xfer = chan->slave_src_burst;
522		/* Device-to-RAM DMA is unreliable without REQD set */
523		hwdesc->config = NBPF_CHAN_CFG_SAD | (NBPF_CHAN_CFG_DDS & (mem_xfer << 16)) |
524			(NBPF_CHAN_CFG_SDS & (slave_xfer << 12)) | NBPF_CHAN_CFG_REQD |
525			NBPF_CHAN_CFG_SBE;
526		break;
527
528	case DMA_MEM_TO_DEV:
529		slave_xfer = min(mem_xfer, chan->slave_dst_width >= 3 ?
530				 chan->slave_dst_burst : chan->slave_dst_width);
531		hwdesc->config = NBPF_CHAN_CFG_DAD | (NBPF_CHAN_CFG_SDS & (mem_xfer << 12)) |
532			(NBPF_CHAN_CFG_DDS & (slave_xfer << 16)) | NBPF_CHAN_CFG_REQD;
533		break;
534
535	case DMA_MEM_TO_MEM:
536		hwdesc->config = NBPF_CHAN_CFG_TCM | NBPF_CHAN_CFG_TM |
537			(NBPF_CHAN_CFG_SDS & (mem_xfer << 12)) |
538			(NBPF_CHAN_CFG_DDS & (mem_xfer << 16));
539		break;
540
541	default:
542		return -EINVAL;
543	}
544
545	hwdesc->config |= chan->dmarq_cfg | (last ? 0 : NBPF_CHAN_CFG_DEM) |
546		NBPF_CHAN_CFG_DMS;
547
548	dev_dbg(dev, "%s(): desc @ %pad: hdr 0x%x, cfg 0x%x, %zu @ %pad -> %pad\n",
549		__func__, &ldesc->hwdesc_dma_addr, hwdesc->header,
550		hwdesc->config, size, &src, &dst);
551
552	dma_sync_single_for_device(dev, ldesc->hwdesc_dma_addr, sizeof(*hwdesc),
553				   DMA_TO_DEVICE);
554
555	return 0;
556}
557
558static size_t nbpf_bytes_left(struct nbpf_channel *chan)
559{
560	return nbpf_chan_read(chan, NBPF_CHAN_CUR_TR_BYTE);
561}
562
563static void nbpf_configure(struct nbpf_device *nbpf)
564{
565	nbpf_write(nbpf, NBPF_CTRL, NBPF_CTRL_LVINT);
566}
567
568/*		Generic part			*/
569
570/* DMA ENGINE functions */
571static void nbpf_issue_pending(struct dma_chan *dchan)
572{
573	struct nbpf_channel *chan = nbpf_to_chan(dchan);
574	unsigned long flags;
575
576	dev_dbg(dchan->device->dev, "Entry %s()\n", __func__);
577
578	spin_lock_irqsave(&chan->lock, flags);
579	if (list_empty(&chan->queued))
580		goto unlock;
581
582	list_splice_tail_init(&chan->queued, &chan->active);
583
584	if (!chan->running) {
585		struct nbpf_desc *desc = list_first_entry(&chan->active,
586						struct nbpf_desc, node);
587		if (!nbpf_start(desc))
588			chan->running = desc;
589	}
590
591unlock:
592	spin_unlock_irqrestore(&chan->lock, flags);
593}
594
595static enum dma_status nbpf_tx_status(struct dma_chan *dchan,
596		dma_cookie_t cookie, struct dma_tx_state *state)
597{
598	struct nbpf_channel *chan = nbpf_to_chan(dchan);
599	enum dma_status status = dma_cookie_status(dchan, cookie, state);
600
601	if (state) {
602		dma_cookie_t running;
603		unsigned long flags;
604
605		spin_lock_irqsave(&chan->lock, flags);
606		running = chan->running ? chan->running->async_tx.cookie : -EINVAL;
607
608		if (cookie == running) {
609			state->residue = nbpf_bytes_left(chan);
610			dev_dbg(dchan->device->dev, "%s(): residue %u\n", __func__,
611				state->residue);
612		} else if (status == DMA_IN_PROGRESS) {
613			struct nbpf_desc *desc;
614			bool found = false;
615
616			list_for_each_entry(desc, &chan->active, node)
617				if (desc->async_tx.cookie == cookie) {
618					found = true;
619					break;
620				}
621
622			if (!found)
623				list_for_each_entry(desc, &chan->queued, node)
624					if (desc->async_tx.cookie == cookie) {
625						found = true;
626						break;
627
628					}
629
630			state->residue = found ? desc->length : 0;
631		}
632
633		spin_unlock_irqrestore(&chan->lock, flags);
634	}
635
636	if (chan->paused)
637		status = DMA_PAUSED;
638
639	return status;
640}
641
642static dma_cookie_t nbpf_tx_submit(struct dma_async_tx_descriptor *tx)
643{
644	struct nbpf_desc *desc = container_of(tx, struct nbpf_desc, async_tx);
645	struct nbpf_channel *chan = desc->chan;
646	unsigned long flags;
647	dma_cookie_t cookie;
648
649	spin_lock_irqsave(&chan->lock, flags);
650	cookie = dma_cookie_assign(tx);
651	list_add_tail(&desc->node, &chan->queued);
652	spin_unlock_irqrestore(&chan->lock, flags);
653
654	dev_dbg(chan->dma_chan.device->dev, "Entry %s(%d)\n", __func__, cookie);
655
656	return cookie;
657}
658
659static int nbpf_desc_page_alloc(struct nbpf_channel *chan)
660{
661	struct dma_chan *dchan = &chan->dma_chan;
662	struct nbpf_desc_page *dpage = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
663	struct nbpf_link_desc *ldesc;
664	struct nbpf_link_reg *hwdesc;
665	struct nbpf_desc *desc;
666	LIST_HEAD(head);
667	LIST_HEAD(lhead);
668	int i;
669	struct device *dev = dchan->device->dev;
670
671	if (!dpage)
672		return -ENOMEM;
673
674	dev_dbg(dev, "%s(): alloc %lu descriptors, %lu segments, total alloc %zu\n",
675		__func__, NBPF_DESCS_PER_PAGE, NBPF_SEGMENTS_PER_PAGE, sizeof(*dpage));
676
677	for (i = 0, ldesc = dpage->ldesc, hwdesc = dpage->hwdesc;
678	     i < ARRAY_SIZE(dpage->ldesc);
679	     i++, ldesc++, hwdesc++) {
680		ldesc->hwdesc = hwdesc;
681		list_add_tail(&ldesc->node, &lhead);
682		ldesc->hwdesc_dma_addr = dma_map_single(dchan->device->dev,
683					hwdesc, sizeof(*hwdesc), DMA_TO_DEVICE);
684
685		dev_dbg(dev, "%s(): mapped 0x%p to %pad\n", __func__,
686			hwdesc, &ldesc->hwdesc_dma_addr);
687	}
688
689	for (i = 0, desc = dpage->desc;
690	     i < ARRAY_SIZE(dpage->desc);
691	     i++, desc++) {
692		dma_async_tx_descriptor_init(&desc->async_tx, dchan);
693		desc->async_tx.tx_submit = nbpf_tx_submit;
694		desc->chan = chan;
695		INIT_LIST_HEAD(&desc->sg);
696		list_add_tail(&desc->node, &head);
697	}
698
699	/*
700	 * This function cannot be called from interrupt context, so, no need to
701	 * save flags
702	 */
703	spin_lock_irq(&chan->lock);
704	list_splice_tail(&lhead, &chan->free_links);
705	list_splice_tail(&head, &chan->free);
706	list_add(&dpage->node, &chan->desc_page);
707	spin_unlock_irq(&chan->lock);
708
709	return ARRAY_SIZE(dpage->desc);
710}
711
712static void nbpf_desc_put(struct nbpf_desc *desc)
713{
714	struct nbpf_channel *chan = desc->chan;
715	struct nbpf_link_desc *ldesc, *tmp;
716	unsigned long flags;
717
718	spin_lock_irqsave(&chan->lock, flags);
719	list_for_each_entry_safe(ldesc, tmp, &desc->sg, node)
720		list_move(&ldesc->node, &chan->free_links);
721
722	list_add(&desc->node, &chan->free);
723	spin_unlock_irqrestore(&chan->lock, flags);
724}
725
726static void nbpf_scan_acked(struct nbpf_channel *chan)
727{
728	struct nbpf_desc *desc, *tmp;
729	unsigned long flags;
730	LIST_HEAD(head);
731
732	spin_lock_irqsave(&chan->lock, flags);
733	list_for_each_entry_safe(desc, tmp, &chan->done, node)
734		if (async_tx_test_ack(&desc->async_tx) && desc->user_wait) {
735			list_move(&desc->node, &head);
736			desc->user_wait = false;
737		}
738	spin_unlock_irqrestore(&chan->lock, flags);
739
740	list_for_each_entry_safe(desc, tmp, &head, node) {
741		list_del(&desc->node);
742		nbpf_desc_put(desc);
743	}
744}
745
746/*
747 * We have to allocate descriptors with the channel lock dropped. This means,
748 * before we re-acquire the lock buffers can be taken already, so we have to
749 * re-check after re-acquiring the lock and possibly retry, if buffers are gone
750 * again.
751 */
752static struct nbpf_desc *nbpf_desc_get(struct nbpf_channel *chan, size_t len)
753{
754	struct nbpf_desc *desc = NULL;
755	struct nbpf_link_desc *ldesc, *prev = NULL;
756
757	nbpf_scan_acked(chan);
758
759	spin_lock_irq(&chan->lock);
760
761	do {
762		int i = 0, ret;
763
764		if (list_empty(&chan->free)) {
765			/* No more free descriptors */
766			spin_unlock_irq(&chan->lock);
767			ret = nbpf_desc_page_alloc(chan);
768			if (ret < 0)
769				return NULL;
770			spin_lock_irq(&chan->lock);
771			continue;
772		}
773		desc = list_first_entry(&chan->free, struct nbpf_desc, node);
774		list_del(&desc->node);
775
776		do {
777			if (list_empty(&chan->free_links)) {
778				/* No more free link descriptors */
779				spin_unlock_irq(&chan->lock);
780				ret = nbpf_desc_page_alloc(chan);
781				if (ret < 0) {
782					nbpf_desc_put(desc);
783					return NULL;
784				}
785				spin_lock_irq(&chan->lock);
786				continue;
787			}
788
789			ldesc = list_first_entry(&chan->free_links,
790						 struct nbpf_link_desc, node);
791			ldesc->desc = desc;
792			if (prev)
793				prev->hwdesc->next = (u32)ldesc->hwdesc_dma_addr;
794
795			prev = ldesc;
796			list_move_tail(&ldesc->node, &desc->sg);
797
798			i++;
799		} while (i < len);
800	} while (!desc);
801
802	prev->hwdesc->next = 0;
803
804	spin_unlock_irq(&chan->lock);
805
806	return desc;
807}
808
809static void nbpf_chan_idle(struct nbpf_channel *chan)
810{
811	struct nbpf_desc *desc, *tmp;
812	unsigned long flags;
813	LIST_HEAD(head);
814
815	spin_lock_irqsave(&chan->lock, flags);
816
817	list_splice_init(&chan->done, &head);
818	list_splice_init(&chan->active, &head);
819	list_splice_init(&chan->queued, &head);
820
821	chan->running = NULL;
822
823	spin_unlock_irqrestore(&chan->lock, flags);
824
825	list_for_each_entry_safe(desc, tmp, &head, node) {
826		dev_dbg(chan->nbpf->dma_dev.dev, "%s(): force-free desc %p cookie %d\n",
827			__func__, desc, desc->async_tx.cookie);
828		list_del(&desc->node);
829		nbpf_desc_put(desc);
830	}
831}
832
833static int nbpf_pause(struct dma_chan *dchan)
834{
835	struct nbpf_channel *chan = nbpf_to_chan(dchan);
836
837	dev_dbg(dchan->device->dev, "Entry %s\n", __func__);
838
839	chan->paused = true;
840	nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_SETSUS);
841	/* See comment in nbpf_prep_one() */
842	nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_CLREN);
843
844	return 0;
845}
846
847static int nbpf_terminate_all(struct dma_chan *dchan)
848{
849	struct nbpf_channel *chan = nbpf_to_chan(dchan);
850
851	dev_dbg(dchan->device->dev, "Entry %s\n", __func__);
852	dev_dbg(dchan->device->dev, "Terminating\n");
853
854	nbpf_chan_halt(chan);
855	nbpf_chan_idle(chan);
856
857	return 0;
858}
859
860static int nbpf_config(struct dma_chan *dchan,
861		       struct dma_slave_config *config)
862{
863	struct nbpf_channel *chan = nbpf_to_chan(dchan);
864
865	dev_dbg(dchan->device->dev, "Entry %s\n", __func__);
866
867	/*
868	 * We could check config->slave_id to match chan->terminal here,
869	 * but with DT they would be coming from the same source, so
870	 * such a check would be superflous
871	 */
872
873	chan->slave_dst_addr = config->dst_addr;
874	chan->slave_dst_width = nbpf_xfer_size(chan->nbpf,
875					       config->dst_addr_width, 1);
876	chan->slave_dst_burst = nbpf_xfer_size(chan->nbpf,
877					       config->dst_addr_width,
878					       config->dst_maxburst);
879	chan->slave_src_addr = config->src_addr;
880	chan->slave_src_width = nbpf_xfer_size(chan->nbpf,
881					       config->src_addr_width, 1);
882	chan->slave_src_burst = nbpf_xfer_size(chan->nbpf,
883					       config->src_addr_width,
884					       config->src_maxburst);
885
886	return 0;
887}
888
889static struct dma_async_tx_descriptor *nbpf_prep_sg(struct nbpf_channel *chan,
890		struct scatterlist *src_sg, struct scatterlist *dst_sg,
891		size_t len, enum dma_transfer_direction direction,
892		unsigned long flags)
893{
894	struct nbpf_link_desc *ldesc;
895	struct scatterlist *mem_sg;
896	struct nbpf_desc *desc;
897	bool inc_src, inc_dst;
898	size_t data_len = 0;
899	int i = 0;
900
901	switch (direction) {
902	case DMA_DEV_TO_MEM:
903		mem_sg = dst_sg;
904		inc_src = false;
905		inc_dst = true;
906		break;
907
908	case DMA_MEM_TO_DEV:
909		mem_sg = src_sg;
910		inc_src = true;
911		inc_dst = false;
912		break;
913
914	default:
915	case DMA_MEM_TO_MEM:
916		mem_sg = src_sg;
917		inc_src = true;
918		inc_dst = true;
919	}
920
921	desc = nbpf_desc_get(chan, len);
922	if (!desc)
923		return NULL;
924
925	desc->async_tx.flags = flags;
926	desc->async_tx.cookie = -EBUSY;
927	desc->user_wait = false;
928
929	/*
930	 * This is a private descriptor list, and we own the descriptor. No need
931	 * to lock.
932	 */
933	list_for_each_entry(ldesc, &desc->sg, node) {
934		int ret = nbpf_prep_one(ldesc, direction,
935					sg_dma_address(src_sg),
936					sg_dma_address(dst_sg),
937					sg_dma_len(mem_sg),
938					i == len - 1);
939		if (ret < 0) {
940			nbpf_desc_put(desc);
941			return NULL;
942		}
943		data_len += sg_dma_len(mem_sg);
944		if (inc_src)
945			src_sg = sg_next(src_sg);
946		if (inc_dst)
947			dst_sg = sg_next(dst_sg);
948		mem_sg = direction == DMA_DEV_TO_MEM ? dst_sg : src_sg;
949		i++;
950	}
951
952	desc->length = data_len;
953
954	/* The user has to return the descriptor to us ASAP via .tx_submit() */
955	return &desc->async_tx;
956}
957
958static struct dma_async_tx_descriptor *nbpf_prep_memcpy(
959	struct dma_chan *dchan, dma_addr_t dst, dma_addr_t src,
960	size_t len, unsigned long flags)
961{
962	struct nbpf_channel *chan = nbpf_to_chan(dchan);
963	struct scatterlist dst_sg;
964	struct scatterlist src_sg;
965
966	sg_init_table(&dst_sg, 1);
967	sg_init_table(&src_sg, 1);
968
969	sg_dma_address(&dst_sg) = dst;
970	sg_dma_address(&src_sg) = src;
971
972	sg_dma_len(&dst_sg) = len;
973	sg_dma_len(&src_sg) = len;
974
975	dev_dbg(dchan->device->dev, "%s(): %zu @ %pad -> %pad\n",
976		__func__, len, &src, &dst);
977
978	return nbpf_prep_sg(chan, &src_sg, &dst_sg, 1,
979			    DMA_MEM_TO_MEM, flags);
980}
981
982static struct dma_async_tx_descriptor *nbpf_prep_memcpy_sg(
983	struct dma_chan *dchan,
984	struct scatterlist *dst_sg, unsigned int dst_nents,
985	struct scatterlist *src_sg, unsigned int src_nents,
986	unsigned long flags)
987{
988	struct nbpf_channel *chan = nbpf_to_chan(dchan);
989
990	if (dst_nents != src_nents)
991		return NULL;
992
993	return nbpf_prep_sg(chan, src_sg, dst_sg, src_nents,
994			    DMA_MEM_TO_MEM, flags);
995}
996
997static struct dma_async_tx_descriptor *nbpf_prep_slave_sg(
998	struct dma_chan *dchan, struct scatterlist *sgl, unsigned int sg_len,
999	enum dma_transfer_direction direction, unsigned long flags, void *context)
1000{
1001	struct nbpf_channel *chan = nbpf_to_chan(dchan);
1002	struct scatterlist slave_sg;
1003
1004	dev_dbg(dchan->device->dev, "Entry %s()\n", __func__);
1005
1006	sg_init_table(&slave_sg, 1);
1007
1008	switch (direction) {
1009	case DMA_MEM_TO_DEV:
1010		sg_dma_address(&slave_sg) = chan->slave_dst_addr;
1011		return nbpf_prep_sg(chan, sgl, &slave_sg, sg_len,
1012				    direction, flags);
1013
1014	case DMA_DEV_TO_MEM:
1015		sg_dma_address(&slave_sg) = chan->slave_src_addr;
1016		return nbpf_prep_sg(chan, &slave_sg, sgl, sg_len,
1017				    direction, flags);
1018
1019	default:
1020		return NULL;
1021	}
1022}
1023
1024static int nbpf_alloc_chan_resources(struct dma_chan *dchan)
1025{
1026	struct nbpf_channel *chan = nbpf_to_chan(dchan);
1027	int ret;
1028
1029	INIT_LIST_HEAD(&chan->free);
1030	INIT_LIST_HEAD(&chan->free_links);
1031	INIT_LIST_HEAD(&chan->queued);
1032	INIT_LIST_HEAD(&chan->active);
1033	INIT_LIST_HEAD(&chan->done);
1034
1035	ret = nbpf_desc_page_alloc(chan);
1036	if (ret < 0)
1037		return ret;
1038
1039	dev_dbg(dchan->device->dev, "Entry %s(): terminal %u\n", __func__,
1040		chan->terminal);
1041
1042	nbpf_chan_configure(chan);
1043
1044	return ret;
1045}
1046
1047static void nbpf_free_chan_resources(struct dma_chan *dchan)
1048{
1049	struct nbpf_channel *chan = nbpf_to_chan(dchan);
1050	struct nbpf_desc_page *dpage, *tmp;
1051
1052	dev_dbg(dchan->device->dev, "Entry %s()\n", __func__);
1053
1054	nbpf_chan_halt(chan);
1055	nbpf_chan_idle(chan);
1056	/* Clean up for if a channel is re-used for MEMCPY after slave DMA */
1057	nbpf_chan_prepare_default(chan);
1058
1059	list_for_each_entry_safe(dpage, tmp, &chan->desc_page, node) {
1060		struct nbpf_link_desc *ldesc;
1061		int i;
1062		list_del(&dpage->node);
1063		for (i = 0, ldesc = dpage->ldesc;
1064		     i < ARRAY_SIZE(dpage->ldesc);
1065		     i++, ldesc++)
1066			dma_unmap_single(dchan->device->dev, ldesc->hwdesc_dma_addr,
1067					 sizeof(*ldesc->hwdesc), DMA_TO_DEVICE);
1068		free_page((unsigned long)dpage);
1069	}
1070}
1071
1072static struct dma_chan *nbpf_of_xlate(struct of_phandle_args *dma_spec,
1073				      struct of_dma *ofdma)
1074{
1075	struct nbpf_device *nbpf = ofdma->of_dma_data;
1076	struct dma_chan *dchan;
1077	struct nbpf_channel *chan;
1078
1079	if (dma_spec->args_count != 2)
1080		return NULL;
1081
1082	dchan = dma_get_any_slave_channel(&nbpf->dma_dev);
1083	if (!dchan)
1084		return NULL;
1085
1086	dev_dbg(dchan->device->dev, "Entry %s(%s)\n", __func__,
1087		dma_spec->np->name);
1088
1089	chan = nbpf_to_chan(dchan);
1090
1091	chan->terminal = dma_spec->args[0];
1092	chan->flags = dma_spec->args[1];
1093
1094	nbpf_chan_prepare(chan);
1095	nbpf_chan_configure(chan);
1096
1097	return dchan;
1098}
1099
1100static void nbpf_chan_tasklet(unsigned long data)
1101{
1102	struct nbpf_channel *chan = (struct nbpf_channel *)data;
1103	struct nbpf_desc *desc, *tmp;
1104	dma_async_tx_callback callback;
1105	void *param;
1106
1107	while (!list_empty(&chan->done)) {
1108		bool found = false, must_put, recycling = false;
1109
1110		spin_lock_irq(&chan->lock);
1111
1112		list_for_each_entry_safe(desc, tmp, &chan->done, node) {
1113			if (!desc->user_wait) {
1114				/* Newly completed descriptor, have to process */
1115				found = true;
1116				break;
1117			} else if (async_tx_test_ack(&desc->async_tx)) {
1118				/*
1119				 * This descriptor was waiting for a user ACK,
1120				 * it can be recycled now.
1121				 */
1122				list_del(&desc->node);
1123				spin_unlock_irq(&chan->lock);
1124				nbpf_desc_put(desc);
1125				recycling = true;
1126				break;
1127			}
1128		}
1129
1130		if (recycling)
1131			continue;
1132
1133		if (!found) {
1134			/* This can happen if TERMINATE_ALL has been called */
1135			spin_unlock_irq(&chan->lock);
1136			break;
1137		}
1138
1139		dma_cookie_complete(&desc->async_tx);
1140
1141		/*
1142		 * With released lock we cannot dereference desc, maybe it's
1143		 * still on the "done" list
1144		 */
1145		if (async_tx_test_ack(&desc->async_tx)) {
1146			list_del(&desc->node);
1147			must_put = true;
1148		} else {
1149			desc->user_wait = true;
1150			must_put = false;
1151		}
1152
1153		callback = desc->async_tx.callback;
1154		param = desc->async_tx.callback_param;
1155
1156		/* ack and callback completed descriptor */
1157		spin_unlock_irq(&chan->lock);
1158
1159		if (callback)
1160			callback(param);
1161
1162		if (must_put)
1163			nbpf_desc_put(desc);
1164	}
1165}
1166
1167static irqreturn_t nbpf_chan_irq(int irq, void *dev)
1168{
1169	struct nbpf_channel *chan = dev;
1170	bool done = nbpf_status_get(chan);
1171	struct nbpf_desc *desc;
1172	irqreturn_t ret;
1173	bool bh = false;
1174
1175	if (!done)
1176		return IRQ_NONE;
1177
1178	nbpf_status_ack(chan);
1179
1180	dev_dbg(&chan->dma_chan.dev->device, "%s()\n", __func__);
1181
1182	spin_lock(&chan->lock);
1183	desc = chan->running;
1184	if (WARN_ON(!desc)) {
1185		ret = IRQ_NONE;
1186		goto unlock;
1187	} else {
1188		ret = IRQ_HANDLED;
1189		bh = true;
1190	}
1191
1192	list_move_tail(&desc->node, &chan->done);
1193	chan->running = NULL;
1194
1195	if (!list_empty(&chan->active)) {
1196		desc = list_first_entry(&chan->active,
1197					struct nbpf_desc, node);
1198		if (!nbpf_start(desc))
1199			chan->running = desc;
1200	}
1201
1202unlock:
1203	spin_unlock(&chan->lock);
1204
1205	if (bh)
1206		tasklet_schedule(&chan->tasklet);
1207
1208	return ret;
1209}
1210
1211static irqreturn_t nbpf_err_irq(int irq, void *dev)
1212{
1213	struct nbpf_device *nbpf = dev;
1214	u32 error = nbpf_error_get(nbpf);
1215
1216	dev_warn(nbpf->dma_dev.dev, "DMA error IRQ %u\n", irq);
1217
1218	if (!error)
1219		return IRQ_NONE;
1220
1221	do {
1222		struct nbpf_channel *chan = nbpf_error_get_channel(nbpf, error);
1223		/* On error: abort all queued transfers, no callback */
1224		nbpf_error_clear(chan);
1225		nbpf_chan_idle(chan);
1226		error = nbpf_error_get(nbpf);
1227	} while (error);
1228
1229	return IRQ_HANDLED;
1230}
1231
1232static int nbpf_chan_probe(struct nbpf_device *nbpf, int n)
1233{
1234	struct dma_device *dma_dev = &nbpf->dma_dev;
1235	struct nbpf_channel *chan = nbpf->chan + n;
1236	int ret;
1237
1238	chan->nbpf = nbpf;
1239	chan->base = nbpf->base + NBPF_REG_CHAN_OFFSET + NBPF_REG_CHAN_SIZE * n;
1240	INIT_LIST_HEAD(&chan->desc_page);
1241	spin_lock_init(&chan->lock);
1242	chan->dma_chan.device = dma_dev;
1243	dma_cookie_init(&chan->dma_chan);
1244	nbpf_chan_prepare_default(chan);
1245
1246	dev_dbg(dma_dev->dev, "%s(): channel %d: -> %p\n", __func__, n, chan->base);
1247
1248	snprintf(chan->name, sizeof(chan->name), "nbpf %d", n);
1249
1250	tasklet_init(&chan->tasklet, nbpf_chan_tasklet, (unsigned long)chan);
1251	ret = devm_request_irq(dma_dev->dev, chan->irq,
1252			nbpf_chan_irq, IRQF_SHARED,
1253			chan->name, chan);
1254	if (ret < 0)
1255		return ret;
1256
1257	/* Add the channel to DMA device channel list */
1258	list_add_tail(&chan->dma_chan.device_node,
1259		      &dma_dev->channels);
1260
1261	return 0;
1262}
1263
1264static const struct of_device_id nbpf_match[] = {
1265	{.compatible = "renesas,nbpfaxi64dmac1b4",	.data = &nbpf_cfg[NBPF1B4]},
1266	{.compatible = "renesas,nbpfaxi64dmac1b8",	.data = &nbpf_cfg[NBPF1B8]},
1267	{.compatible = "renesas,nbpfaxi64dmac1b16",	.data = &nbpf_cfg[NBPF1B16]},
1268	{.compatible = "renesas,nbpfaxi64dmac4b4",	.data = &nbpf_cfg[NBPF4B4]},
1269	{.compatible = "renesas,nbpfaxi64dmac4b8",	.data = &nbpf_cfg[NBPF4B8]},
1270	{.compatible = "renesas,nbpfaxi64dmac4b16",	.data = &nbpf_cfg[NBPF4B16]},
1271	{.compatible = "renesas,nbpfaxi64dmac8b4",	.data = &nbpf_cfg[NBPF8B4]},
1272	{.compatible = "renesas,nbpfaxi64dmac8b8",	.data = &nbpf_cfg[NBPF8B8]},
1273	{.compatible = "renesas,nbpfaxi64dmac8b16",	.data = &nbpf_cfg[NBPF8B16]},
1274	{}
1275};
1276MODULE_DEVICE_TABLE(of, nbpf_match);
1277
1278static int nbpf_probe(struct platform_device *pdev)
1279{
1280	struct device *dev = &pdev->dev;
1281	const struct of_device_id *of_id = of_match_device(nbpf_match, dev);
1282	struct device_node *np = dev->of_node;
1283	struct nbpf_device *nbpf;
1284	struct dma_device *dma_dev;
1285	struct resource *iomem, *irq_res;
1286	const struct nbpf_config *cfg;
1287	int num_channels;
1288	int ret, irq, eirq, i;
1289	int irqbuf[9] /* maximum 8 channels + error IRQ */;
1290	unsigned int irqs = 0;
1291
1292	BUILD_BUG_ON(sizeof(struct nbpf_desc_page) > PAGE_SIZE);
1293
1294	/* DT only */
1295	if (!np || !of_id || !of_id->data)
1296		return -ENODEV;
1297
1298	cfg = of_id->data;
1299	num_channels = cfg->num_channels;
1300
1301	nbpf = devm_kzalloc(dev, sizeof(*nbpf) + num_channels *
1302			    sizeof(nbpf->chan[0]), GFP_KERNEL);
1303	if (!nbpf) {
1304		dev_err(dev, "Memory allocation failed\n");
1305		return -ENOMEM;
1306	}
1307	dma_dev = &nbpf->dma_dev;
1308	dma_dev->dev = dev;
1309
1310	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1311	nbpf->base = devm_ioremap_resource(dev, iomem);
1312	if (IS_ERR(nbpf->base))
1313		return PTR_ERR(nbpf->base);
1314
1315	nbpf->clk = devm_clk_get(dev, NULL);
1316	if (IS_ERR(nbpf->clk))
1317		return PTR_ERR(nbpf->clk);
1318
1319	nbpf->config = cfg;
1320
1321	for (i = 0; irqs < ARRAY_SIZE(irqbuf); i++) {
1322		irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
1323		if (!irq_res)
1324			break;
1325
1326		for (irq = irq_res->start; irq <= irq_res->end;
1327		     irq++, irqs++)
1328			irqbuf[irqs] = irq;
1329	}
1330
1331	/*
1332	 * 3 IRQ resource schemes are supported:
1333	 * 1. 1 shared IRQ for error and all channels
1334	 * 2. 2 IRQs: one for error and one shared for all channels
1335	 * 3. 1 IRQ for error and an own IRQ for each channel
1336	 */
1337	if (irqs != 1 && irqs != 2 && irqs != num_channels + 1)
1338		return -ENXIO;
1339
1340	if (irqs == 1) {
1341		eirq = irqbuf[0];
1342
1343		for (i = 0; i <= num_channels; i++)
1344			nbpf->chan[i].irq = irqbuf[0];
1345	} else {
1346		eirq = platform_get_irq_byname(pdev, "error");
1347		if (eirq < 0)
1348			return eirq;
1349
1350		if (irqs == num_channels + 1) {
1351			struct nbpf_channel *chan;
1352
1353			for (i = 0, chan = nbpf->chan; i <= num_channels;
1354			     i++, chan++) {
1355				/* Skip the error IRQ */
1356				if (irqbuf[i] == eirq)
1357					i++;
1358				chan->irq = irqbuf[i];
1359			}
1360
1361			if (chan != nbpf->chan + num_channels)
1362				return -EINVAL;
1363		} else {
1364			/* 2 IRQs and more than one channel */
1365			if (irqbuf[0] == eirq)
1366				irq = irqbuf[1];
1367			else
1368				irq = irqbuf[0];
1369
1370			for (i = 0; i <= num_channels; i++)
1371				nbpf->chan[i].irq = irq;
1372		}
1373	}
1374
1375	ret = devm_request_irq(dev, eirq, nbpf_err_irq,
1376			       IRQF_SHARED, "dma error", nbpf);
1377	if (ret < 0)
1378		return ret;
1379
1380	INIT_LIST_HEAD(&dma_dev->channels);
1381
1382	/* Create DMA Channel */
1383	for (i = 0; i < num_channels; i++) {
1384		ret = nbpf_chan_probe(nbpf, i);
1385		if (ret < 0)
1386			return ret;
1387	}
1388
1389	dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
1390	dma_cap_set(DMA_SLAVE, dma_dev->cap_mask);
1391	dma_cap_set(DMA_PRIVATE, dma_dev->cap_mask);
1392	dma_cap_set(DMA_SG, dma_dev->cap_mask);
1393
1394	/* Common and MEMCPY operations */
1395	dma_dev->device_alloc_chan_resources
1396		= nbpf_alloc_chan_resources;
1397	dma_dev->device_free_chan_resources = nbpf_free_chan_resources;
1398	dma_dev->device_prep_dma_sg = nbpf_prep_memcpy_sg;
1399	dma_dev->device_prep_dma_memcpy = nbpf_prep_memcpy;
1400	dma_dev->device_tx_status = nbpf_tx_status;
1401	dma_dev->device_issue_pending = nbpf_issue_pending;
1402
1403	/*
1404	 * If we drop support for unaligned MEMCPY buffer addresses and / or
1405	 * lengths by setting
1406	 * dma_dev->copy_align = 4;
1407	 * then we can set transfer length to 4 bytes in nbpf_prep_one() for
1408	 * DMA_MEM_TO_MEM
1409	 */
1410
1411	/* Compulsory for DMA_SLAVE fields */
1412	dma_dev->device_prep_slave_sg = nbpf_prep_slave_sg;
1413	dma_dev->device_config = nbpf_config;
1414	dma_dev->device_pause = nbpf_pause;
1415	dma_dev->device_terminate_all = nbpf_terminate_all;
1416
1417	dma_dev->src_addr_widths = NBPF_DMA_BUSWIDTHS;
1418	dma_dev->dst_addr_widths = NBPF_DMA_BUSWIDTHS;
1419	dma_dev->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1420
1421	platform_set_drvdata(pdev, nbpf);
1422
1423	ret = clk_prepare_enable(nbpf->clk);
1424	if (ret < 0)
1425		return ret;
1426
1427	nbpf_configure(nbpf);
1428
1429	ret = dma_async_device_register(dma_dev);
1430	if (ret < 0)
1431		goto e_clk_off;
1432
1433	ret = of_dma_controller_register(np, nbpf_of_xlate, nbpf);
1434	if (ret < 0)
1435		goto e_dma_dev_unreg;
1436
1437	return 0;
1438
1439e_dma_dev_unreg:
1440	dma_async_device_unregister(dma_dev);
1441e_clk_off:
1442	clk_disable_unprepare(nbpf->clk);
1443
1444	return ret;
1445}
1446
1447static int nbpf_remove(struct platform_device *pdev)
1448{
1449	struct nbpf_device *nbpf = platform_get_drvdata(pdev);
1450
1451	of_dma_controller_free(pdev->dev.of_node);
1452	dma_async_device_unregister(&nbpf->dma_dev);
1453	clk_disable_unprepare(nbpf->clk);
1454
1455	return 0;
1456}
1457
1458static const struct platform_device_id nbpf_ids[] = {
1459	{"nbpfaxi64dmac1b4",	(kernel_ulong_t)&nbpf_cfg[NBPF1B4]},
1460	{"nbpfaxi64dmac1b8",	(kernel_ulong_t)&nbpf_cfg[NBPF1B8]},
1461	{"nbpfaxi64dmac1b16",	(kernel_ulong_t)&nbpf_cfg[NBPF1B16]},
1462	{"nbpfaxi64dmac4b4",	(kernel_ulong_t)&nbpf_cfg[NBPF4B4]},
1463	{"nbpfaxi64dmac4b8",	(kernel_ulong_t)&nbpf_cfg[NBPF4B8]},
1464	{"nbpfaxi64dmac4b16",	(kernel_ulong_t)&nbpf_cfg[NBPF4B16]},
1465	{"nbpfaxi64dmac8b4",	(kernel_ulong_t)&nbpf_cfg[NBPF8B4]},
1466	{"nbpfaxi64dmac8b8",	(kernel_ulong_t)&nbpf_cfg[NBPF8B8]},
1467	{"nbpfaxi64dmac8b16",	(kernel_ulong_t)&nbpf_cfg[NBPF8B16]},
1468	{},
1469};
1470MODULE_DEVICE_TABLE(platform, nbpf_ids);
1471
1472#ifdef CONFIG_PM
1473static int nbpf_runtime_suspend(struct device *dev)
1474{
1475	struct nbpf_device *nbpf = platform_get_drvdata(to_platform_device(dev));
1476	clk_disable_unprepare(nbpf->clk);
1477	return 0;
1478}
1479
1480static int nbpf_runtime_resume(struct device *dev)
1481{
1482	struct nbpf_device *nbpf = platform_get_drvdata(to_platform_device(dev));
1483	return clk_prepare_enable(nbpf->clk);
1484}
1485#endif
1486
1487static const struct dev_pm_ops nbpf_pm_ops = {
1488	SET_RUNTIME_PM_OPS(nbpf_runtime_suspend, nbpf_runtime_resume, NULL)
1489};
1490
1491static struct platform_driver nbpf_driver = {
1492	.driver = {
1493		.name = "dma-nbpf",
1494		.of_match_table = nbpf_match,
1495		.pm = &nbpf_pm_ops,
1496	},
1497	.id_table = nbpf_ids,
1498	.probe = nbpf_probe,
1499	.remove = nbpf_remove,
1500};
1501
1502module_platform_driver(nbpf_driver);
1503
1504MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>");
1505MODULE_DESCRIPTION("dmaengine driver for NBPFAXI64* DMACs");
1506MODULE_LICENSE("GPL v2");
1507