xref: /kernel/linux/linux-5.10/drivers/dma/nbpfaxi.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2013-2014 Renesas Electronics Europe Ltd.
4 * Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
5 */
6
7#include <linux/bitmap.h>
8#include <linux/bitops.h>
9#include <linux/clk.h>
10#include <linux/dma-mapping.h>
11#include <linux/dmaengine.h>
12#include <linux/err.h>
13#include <linux/interrupt.h>
14#include <linux/io.h>
15#include <linux/log2.h>
16#include <linux/module.h>
17#include <linux/of.h>
18#include <linux/of_device.h>
19#include <linux/of_dma.h>
20#include <linux/platform_device.h>
21#include <linux/slab.h>
22
23#include <dt-bindings/dma/nbpfaxi.h>
24
25#include "dmaengine.h"
26
27#define NBPF_REG_CHAN_OFFSET	0
28#define NBPF_REG_CHAN_SIZE	0x40
29
30/* Channel Current Transaction Byte register */
31#define NBPF_CHAN_CUR_TR_BYTE	0x20
32
33/* Channel Status register */
34#define NBPF_CHAN_STAT	0x24
35#define NBPF_CHAN_STAT_EN	1
36#define NBPF_CHAN_STAT_TACT	4
37#define NBPF_CHAN_STAT_ERR	0x10
38#define NBPF_CHAN_STAT_END	0x20
39#define NBPF_CHAN_STAT_TC	0x40
40#define NBPF_CHAN_STAT_DER	0x400
41
42/* Channel Control register */
43#define NBPF_CHAN_CTRL	0x28
44#define NBPF_CHAN_CTRL_SETEN	1
45#define NBPF_CHAN_CTRL_CLREN	2
46#define NBPF_CHAN_CTRL_STG	4
47#define NBPF_CHAN_CTRL_SWRST	8
48#define NBPF_CHAN_CTRL_CLRRQ	0x10
49#define NBPF_CHAN_CTRL_CLREND	0x20
50#define NBPF_CHAN_CTRL_CLRTC	0x40
51#define NBPF_CHAN_CTRL_SETSUS	0x100
52#define NBPF_CHAN_CTRL_CLRSUS	0x200
53
54/* Channel Configuration register */
55#define NBPF_CHAN_CFG	0x2c
56#define NBPF_CHAN_CFG_SEL	7		/* terminal SELect: 0..7 */
57#define NBPF_CHAN_CFG_REQD	8		/* REQuest Direction: DMAREQ is 0: input, 1: output */
58#define NBPF_CHAN_CFG_LOEN	0x10		/* LOw ENable: low DMA request line is: 0: inactive, 1: active */
59#define NBPF_CHAN_CFG_HIEN	0x20		/* HIgh ENable: high DMA request line is: 0: inactive, 1: active */
60#define NBPF_CHAN_CFG_LVL	0x40		/* LeVeL: DMA request line is sensed as 0: edge, 1: level */
61#define NBPF_CHAN_CFG_AM	0x700		/* ACK Mode: 0: Pulse mode, 1: Level mode, b'1x: Bus Cycle */
62#define NBPF_CHAN_CFG_SDS	0xf000		/* Source Data Size: 0: 8 bits,... , 7: 1024 bits */
63#define NBPF_CHAN_CFG_DDS	0xf0000		/* Destination Data Size: as above */
64#define NBPF_CHAN_CFG_SAD	0x100000	/* Source ADdress counting: 0: increment, 1: fixed */
65#define NBPF_CHAN_CFG_DAD	0x200000	/* Destination ADdress counting: 0: increment, 1: fixed */
66#define NBPF_CHAN_CFG_TM	0x400000	/* Transfer Mode: 0: single, 1: block TM */
67#define NBPF_CHAN_CFG_DEM	0x1000000	/* DMAEND interrupt Mask */
68#define NBPF_CHAN_CFG_TCM	0x2000000	/* DMATCO interrupt Mask */
69#define NBPF_CHAN_CFG_SBE	0x8000000	/* Sweep Buffer Enable */
70#define NBPF_CHAN_CFG_RSEL	0x10000000	/* RM: Register Set sELect */
71#define NBPF_CHAN_CFG_RSW	0x20000000	/* RM: Register Select sWitch */
72#define NBPF_CHAN_CFG_REN	0x40000000	/* RM: Register Set Enable */
73#define NBPF_CHAN_CFG_DMS	0x80000000	/* 0: register mode (RM), 1: link mode (LM) */
74
75#define NBPF_CHAN_NXLA	0x38
76#define NBPF_CHAN_CRLA	0x3c
77
78/* Link Header field */
79#define NBPF_HEADER_LV	1
80#define NBPF_HEADER_LE	2
81#define NBPF_HEADER_WBD	4
82#define NBPF_HEADER_DIM	8
83
84#define NBPF_CTRL	0x300
85#define NBPF_CTRL_PR	1		/* 0: fixed priority, 1: round robin */
86#define NBPF_CTRL_LVINT	2		/* DMAEND and DMAERR signalling: 0: pulse, 1: level */
87
88#define NBPF_DSTAT_ER	0x314
89#define NBPF_DSTAT_END	0x318
90
91#define NBPF_DMA_BUSWIDTHS \
92	(BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) | \
93	 BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
94	 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
95	 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \
96	 BIT(DMA_SLAVE_BUSWIDTH_8_BYTES))
97
98struct nbpf_config {
99	int num_channels;
100	int buffer_size;
101};
102
103/*
104 * We've got 3 types of objects, used to describe DMA transfers:
105 * 1. high-level descriptor, containing a struct dma_async_tx_descriptor object
106 *	in it, used to communicate with the user
107 * 2. hardware DMA link descriptors, that we pass to DMAC for DMA transfer
108 *	queuing, these must be DMAable, using either the streaming DMA API or
109 *	allocated from coherent memory - one per SG segment
110 * 3. one per SG segment descriptors, used to manage HW link descriptors from
111 *	(2). They do not have to be DMAable. They can either be (a) allocated
112 *	together with link descriptors as mixed (DMA / CPU) objects, or (b)
113 *	separately. Even if allocated separately it would be best to link them
114 *	to link descriptors once during channel resource allocation and always
115 *	use them as a single object.
116 * Therefore for both cases (a) and (b) at run-time objects (2) and (3) shall be
117 * treated as a single SG segment descriptor.
118 */
119
120struct nbpf_link_reg {
121	u32	header;
122	u32	src_addr;
123	u32	dst_addr;
124	u32	transaction_size;
125	u32	config;
126	u32	interval;
127	u32	extension;
128	u32	next;
129} __packed;
130
131struct nbpf_device;
132struct nbpf_channel;
133struct nbpf_desc;
134
135struct nbpf_link_desc {
136	struct nbpf_link_reg *hwdesc;
137	dma_addr_t hwdesc_dma_addr;
138	struct nbpf_desc *desc;
139	struct list_head node;
140};
141
142/**
143 * struct nbpf_desc - DMA transfer descriptor
144 * @async_tx:	dmaengine object
145 * @user_wait:	waiting for a user ack
146 * @length:	total transfer length
147 * @chan:	associated DMAC channel
148 * @sg:		list of hardware descriptors, represented by struct nbpf_link_desc
149 * @node:	member in channel descriptor lists
150 */
151struct nbpf_desc {
152	struct dma_async_tx_descriptor async_tx;
153	bool user_wait;
154	size_t length;
155	struct nbpf_channel *chan;
156	struct list_head sg;
157	struct list_head node;
158};
159
160/* Take a wild guess: allocate 4 segments per descriptor */
161#define NBPF_SEGMENTS_PER_DESC 4
162#define NBPF_DESCS_PER_PAGE ((PAGE_SIZE - sizeof(struct list_head)) /	\
163	(sizeof(struct nbpf_desc) +					\
164	 NBPF_SEGMENTS_PER_DESC *					\
165	 (sizeof(struct nbpf_link_desc) + sizeof(struct nbpf_link_reg))))
166#define NBPF_SEGMENTS_PER_PAGE (NBPF_SEGMENTS_PER_DESC * NBPF_DESCS_PER_PAGE)
167
168struct nbpf_desc_page {
169	struct list_head node;
170	struct nbpf_desc desc[NBPF_DESCS_PER_PAGE];
171	struct nbpf_link_desc ldesc[NBPF_SEGMENTS_PER_PAGE];
172	struct nbpf_link_reg hwdesc[NBPF_SEGMENTS_PER_PAGE];
173};
174
175/**
176 * struct nbpf_channel - one DMAC channel
177 * @dma_chan:	standard dmaengine channel object
178 * @tasklet:	channel specific tasklet used for callbacks
179 * @base:	register address base
180 * @nbpf:	DMAC
181 * @name:	IRQ name
182 * @irq:	IRQ number
183 * @slave_src_addr:	source address for slave DMA
184 * @slave_src_width:	source slave data size in bytes
185 * @slave_src_burst:	maximum source slave burst size in bytes
186 * @slave_dst_addr:	destination address for slave DMA
187 * @slave_dst_width:	destination slave data size in bytes
188 * @slave_dst_burst:	maximum destination slave burst size in bytes
189 * @terminal:	DMA terminal, assigned to this channel
190 * @dmarq_cfg:	DMA request line configuration - high / low, edge / level for NBPF_CHAN_CFG
191 * @flags:	configuration flags from DT
192 * @lock:	protect descriptor lists
193 * @free_links:	list of free link descriptors
194 * @free:	list of free descriptors
195 * @queued:	list of queued descriptors
196 * @active:	list of descriptors, scheduled for processing
197 * @done:	list of completed descriptors, waiting post-processing
198 * @desc_page:	list of additionally allocated descriptor pages - if any
199 * @running:	linked descriptor of running transaction
200 * @paused:	are translations on this channel paused?
201 */
202struct nbpf_channel {
203	struct dma_chan dma_chan;
204	struct tasklet_struct tasklet;
205	void __iomem *base;
206	struct nbpf_device *nbpf;
207	char name[16];
208	int irq;
209	dma_addr_t slave_src_addr;
210	size_t slave_src_width;
211	size_t slave_src_burst;
212	dma_addr_t slave_dst_addr;
213	size_t slave_dst_width;
214	size_t slave_dst_burst;
215	unsigned int terminal;
216	u32 dmarq_cfg;
217	unsigned long flags;
218	spinlock_t lock;
219	struct list_head free_links;
220	struct list_head free;
221	struct list_head queued;
222	struct list_head active;
223	struct list_head done;
224	struct list_head desc_page;
225	struct nbpf_desc *running;
226	bool paused;
227};
228
229struct nbpf_device {
230	struct dma_device dma_dev;
231	void __iomem *base;
232	u32 max_burst_mem_read;
233	u32 max_burst_mem_write;
234	struct clk *clk;
235	const struct nbpf_config *config;
236	unsigned int eirq;
237	struct nbpf_channel chan[];
238};
239
240enum nbpf_model {
241	NBPF1B4,
242	NBPF1B8,
243	NBPF1B16,
244	NBPF4B4,
245	NBPF4B8,
246	NBPF4B16,
247	NBPF8B4,
248	NBPF8B8,
249	NBPF8B16,
250};
251
252static struct nbpf_config nbpf_cfg[] = {
253	[NBPF1B4] = {
254		.num_channels = 1,
255		.buffer_size = 4,
256	},
257	[NBPF1B8] = {
258		.num_channels = 1,
259		.buffer_size = 8,
260	},
261	[NBPF1B16] = {
262		.num_channels = 1,
263		.buffer_size = 16,
264	},
265	[NBPF4B4] = {
266		.num_channels = 4,
267		.buffer_size = 4,
268	},
269	[NBPF4B8] = {
270		.num_channels = 4,
271		.buffer_size = 8,
272	},
273	[NBPF4B16] = {
274		.num_channels = 4,
275		.buffer_size = 16,
276	},
277	[NBPF8B4] = {
278		.num_channels = 8,
279		.buffer_size = 4,
280	},
281	[NBPF8B8] = {
282		.num_channels = 8,
283		.buffer_size = 8,
284	},
285	[NBPF8B16] = {
286		.num_channels = 8,
287		.buffer_size = 16,
288	},
289};
290
291#define nbpf_to_chan(d) container_of(d, struct nbpf_channel, dma_chan)
292
293/*
294 * dmaengine drivers seem to have a lot in common and instead of sharing more
295 * code, they reimplement those common algorithms independently. In this driver
296 * we try to separate the hardware-specific part from the (largely) generic
297 * part. This improves code readability and makes it possible in the future to
298 * reuse the generic code in form of a helper library. That generic code should
299 * be suitable for various DMA controllers, using transfer descriptors in RAM
300 * and pushing one SG list at a time to the DMA controller.
301 */
302
303/*		Hardware-specific part		*/
304
305static inline u32 nbpf_chan_read(struct nbpf_channel *chan,
306				 unsigned int offset)
307{
308	u32 data = ioread32(chan->base + offset);
309	dev_dbg(chan->dma_chan.device->dev, "%s(0x%p + 0x%x) = 0x%x\n",
310		__func__, chan->base, offset, data);
311	return data;
312}
313
314static inline void nbpf_chan_write(struct nbpf_channel *chan,
315				   unsigned int offset, u32 data)
316{
317	iowrite32(data, chan->base + offset);
318	dev_dbg(chan->dma_chan.device->dev, "%s(0x%p + 0x%x) = 0x%x\n",
319		__func__, chan->base, offset, data);
320}
321
322static inline u32 nbpf_read(struct nbpf_device *nbpf,
323			    unsigned int offset)
324{
325	u32 data = ioread32(nbpf->base + offset);
326	dev_dbg(nbpf->dma_dev.dev, "%s(0x%p + 0x%x) = 0x%x\n",
327		__func__, nbpf->base, offset, data);
328	return data;
329}
330
331static inline void nbpf_write(struct nbpf_device *nbpf,
332			      unsigned int offset, u32 data)
333{
334	iowrite32(data, nbpf->base + offset);
335	dev_dbg(nbpf->dma_dev.dev, "%s(0x%p + 0x%x) = 0x%x\n",
336		__func__, nbpf->base, offset, data);
337}
338
339static void nbpf_chan_halt(struct nbpf_channel *chan)
340{
341	nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_CLREN);
342}
343
344static bool nbpf_status_get(struct nbpf_channel *chan)
345{
346	u32 status = nbpf_read(chan->nbpf, NBPF_DSTAT_END);
347
348	return status & BIT(chan - chan->nbpf->chan);
349}
350
351static void nbpf_status_ack(struct nbpf_channel *chan)
352{
353	nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_CLREND);
354}
355
356static u32 nbpf_error_get(struct nbpf_device *nbpf)
357{
358	return nbpf_read(nbpf, NBPF_DSTAT_ER);
359}
360
361static struct nbpf_channel *nbpf_error_get_channel(struct nbpf_device *nbpf, u32 error)
362{
363	return nbpf->chan + __ffs(error);
364}
365
366static void nbpf_error_clear(struct nbpf_channel *chan)
367{
368	u32 status;
369	int i;
370
371	/* Stop the channel, make sure DMA has been aborted */
372	nbpf_chan_halt(chan);
373
374	for (i = 1000; i; i--) {
375		status = nbpf_chan_read(chan, NBPF_CHAN_STAT);
376		if (!(status & NBPF_CHAN_STAT_TACT))
377			break;
378		cpu_relax();
379	}
380
381	if (!i)
382		dev_err(chan->dma_chan.device->dev,
383			"%s(): abort timeout, channel status 0x%x\n", __func__, status);
384
385	nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_SWRST);
386}
387
388static int nbpf_start(struct nbpf_desc *desc)
389{
390	struct nbpf_channel *chan = desc->chan;
391	struct nbpf_link_desc *ldesc = list_first_entry(&desc->sg, struct nbpf_link_desc, node);
392
393	nbpf_chan_write(chan, NBPF_CHAN_NXLA, (u32)ldesc->hwdesc_dma_addr);
394	nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_SETEN | NBPF_CHAN_CTRL_CLRSUS);
395	chan->paused = false;
396
397	/* Software trigger MEMCPY - only MEMCPY uses the block mode */
398	if (ldesc->hwdesc->config & NBPF_CHAN_CFG_TM)
399		nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_STG);
400
401	dev_dbg(chan->nbpf->dma_dev.dev, "%s(): next 0x%x, cur 0x%x\n", __func__,
402		nbpf_chan_read(chan, NBPF_CHAN_NXLA), nbpf_chan_read(chan, NBPF_CHAN_CRLA));
403
404	return 0;
405}
406
407static void nbpf_chan_prepare(struct nbpf_channel *chan)
408{
409	chan->dmarq_cfg = (chan->flags & NBPF_SLAVE_RQ_HIGH ? NBPF_CHAN_CFG_HIEN : 0) |
410		(chan->flags & NBPF_SLAVE_RQ_LOW ? NBPF_CHAN_CFG_LOEN : 0) |
411		(chan->flags & NBPF_SLAVE_RQ_LEVEL ?
412		 NBPF_CHAN_CFG_LVL | (NBPF_CHAN_CFG_AM & 0x200) : 0) |
413		chan->terminal;
414}
415
416static void nbpf_chan_prepare_default(struct nbpf_channel *chan)
417{
418	/* Don't output DMAACK */
419	chan->dmarq_cfg = NBPF_CHAN_CFG_AM & 0x400;
420	chan->terminal = 0;
421	chan->flags = 0;
422}
423
424static void nbpf_chan_configure(struct nbpf_channel *chan)
425{
426	/*
427	 * We assume, that only the link mode and DMA request line configuration
428	 * have to be set in the configuration register manually. Dynamic
429	 * per-transfer configuration will be loaded from transfer descriptors.
430	 */
431	nbpf_chan_write(chan, NBPF_CHAN_CFG, NBPF_CHAN_CFG_DMS | chan->dmarq_cfg);
432}
433
434static u32 nbpf_xfer_ds(struct nbpf_device *nbpf, size_t size,
435			enum dma_transfer_direction direction)
436{
437	int max_burst = nbpf->config->buffer_size * 8;
438
439	if (nbpf->max_burst_mem_read || nbpf->max_burst_mem_write) {
440		switch (direction) {
441		case DMA_MEM_TO_MEM:
442			max_burst = min_not_zero(nbpf->max_burst_mem_read,
443						 nbpf->max_burst_mem_write);
444			break;
445		case DMA_MEM_TO_DEV:
446			if (nbpf->max_burst_mem_read)
447				max_burst = nbpf->max_burst_mem_read;
448			break;
449		case DMA_DEV_TO_MEM:
450			if (nbpf->max_burst_mem_write)
451				max_burst = nbpf->max_burst_mem_write;
452			break;
453		case DMA_DEV_TO_DEV:
454		default:
455			break;
456		}
457	}
458
459	/* Maximum supported bursts depend on the buffer size */
460	return min_t(int, __ffs(size), ilog2(max_burst));
461}
462
463static size_t nbpf_xfer_size(struct nbpf_device *nbpf,
464			     enum dma_slave_buswidth width, u32 burst)
465{
466	size_t size;
467
468	if (!burst)
469		burst = 1;
470
471	switch (width) {
472	case DMA_SLAVE_BUSWIDTH_8_BYTES:
473		size = 8 * burst;
474		break;
475
476	case DMA_SLAVE_BUSWIDTH_4_BYTES:
477		size = 4 * burst;
478		break;
479
480	case DMA_SLAVE_BUSWIDTH_2_BYTES:
481		size = 2 * burst;
482		break;
483
484	default:
485		pr_warn("%s(): invalid bus width %u\n", __func__, width);
486		fallthrough;
487	case DMA_SLAVE_BUSWIDTH_1_BYTE:
488		size = burst;
489	}
490
491	return nbpf_xfer_ds(nbpf, size, DMA_TRANS_NONE);
492}
493
494/*
495 * We need a way to recognise slaves, whose data is sent "raw" over the bus,
496 * i.e. it isn't known in advance how many bytes will be received. Therefore
497 * the slave driver has to provide a "large enough" buffer and either read the
498 * buffer, when it is full, or detect, that some data has arrived, then wait for
499 * a timeout, if no more data arrives - receive what's already there. We want to
500 * handle such slaves in a special way to allow an optimised mode for other
501 * users, for whom the amount of data is known in advance. So far there's no way
502 * to recognise such slaves. We use a data-width check to distinguish between
503 * the SD host and the PL011 UART.
504 */
505
506static int nbpf_prep_one(struct nbpf_link_desc *ldesc,
507			 enum dma_transfer_direction direction,
508			 dma_addr_t src, dma_addr_t dst, size_t size, bool last)
509{
510	struct nbpf_link_reg *hwdesc = ldesc->hwdesc;
511	struct nbpf_desc *desc = ldesc->desc;
512	struct nbpf_channel *chan = desc->chan;
513	struct device *dev = chan->dma_chan.device->dev;
514	size_t mem_xfer, slave_xfer;
515	bool can_burst;
516
517	hwdesc->header = NBPF_HEADER_WBD | NBPF_HEADER_LV |
518		(last ? NBPF_HEADER_LE : 0);
519
520	hwdesc->src_addr = src;
521	hwdesc->dst_addr = dst;
522	hwdesc->transaction_size = size;
523
524	/*
525	 * set config: SAD, DAD, DDS, SDS, etc.
526	 * Note on transfer sizes: the DMAC can perform unaligned DMA transfers,
527	 * but it is important to have transaction size a multiple of both
528	 * receiver and transmitter transfer sizes. It is also possible to use
529	 * different RAM and device transfer sizes, and it does work well with
530	 * some devices, e.g. with V08R07S01E SD host controllers, which can use
531	 * 128 byte transfers. But this doesn't work with other devices,
532	 * especially when the transaction size is unknown. This is the case,
533	 * e.g. with serial drivers like amba-pl011.c. For reception it sets up
534	 * the transaction size of 4K and if fewer bytes are received, it
535	 * pauses DMA and reads out data received via DMA as well as those left
536	 * in the Rx FIFO. For this to work with the RAM side using burst
537	 * transfers we enable the SBE bit and terminate the transfer in our
538	 * .device_pause handler.
539	 */
540	mem_xfer = nbpf_xfer_ds(chan->nbpf, size, direction);
541
542	switch (direction) {
543	case DMA_DEV_TO_MEM:
544		can_burst = chan->slave_src_width >= 3;
545		slave_xfer = min(mem_xfer, can_burst ?
546				 chan->slave_src_burst : chan->slave_src_width);
547		/*
548		 * Is the slave narrower than 64 bits, i.e. isn't using the full
549		 * bus width and cannot use bursts?
550		 */
551		if (mem_xfer > chan->slave_src_burst && !can_burst)
552			mem_xfer = chan->slave_src_burst;
553		/* Device-to-RAM DMA is unreliable without REQD set */
554		hwdesc->config = NBPF_CHAN_CFG_SAD | (NBPF_CHAN_CFG_DDS & (mem_xfer << 16)) |
555			(NBPF_CHAN_CFG_SDS & (slave_xfer << 12)) | NBPF_CHAN_CFG_REQD |
556			NBPF_CHAN_CFG_SBE;
557		break;
558
559	case DMA_MEM_TO_DEV:
560		slave_xfer = min(mem_xfer, chan->slave_dst_width >= 3 ?
561				 chan->slave_dst_burst : chan->slave_dst_width);
562		hwdesc->config = NBPF_CHAN_CFG_DAD | (NBPF_CHAN_CFG_SDS & (mem_xfer << 12)) |
563			(NBPF_CHAN_CFG_DDS & (slave_xfer << 16)) | NBPF_CHAN_CFG_REQD;
564		break;
565
566	case DMA_MEM_TO_MEM:
567		hwdesc->config = NBPF_CHAN_CFG_TCM | NBPF_CHAN_CFG_TM |
568			(NBPF_CHAN_CFG_SDS & (mem_xfer << 12)) |
569			(NBPF_CHAN_CFG_DDS & (mem_xfer << 16));
570		break;
571
572	default:
573		return -EINVAL;
574	}
575
576	hwdesc->config |= chan->dmarq_cfg | (last ? 0 : NBPF_CHAN_CFG_DEM) |
577		NBPF_CHAN_CFG_DMS;
578
579	dev_dbg(dev, "%s(): desc @ %pad: hdr 0x%x, cfg 0x%x, %zu @ %pad -> %pad\n",
580		__func__, &ldesc->hwdesc_dma_addr, hwdesc->header,
581		hwdesc->config, size, &src, &dst);
582
583	dma_sync_single_for_device(dev, ldesc->hwdesc_dma_addr, sizeof(*hwdesc),
584				   DMA_TO_DEVICE);
585
586	return 0;
587}
588
589static size_t nbpf_bytes_left(struct nbpf_channel *chan)
590{
591	return nbpf_chan_read(chan, NBPF_CHAN_CUR_TR_BYTE);
592}
593
594static void nbpf_configure(struct nbpf_device *nbpf)
595{
596	nbpf_write(nbpf, NBPF_CTRL, NBPF_CTRL_LVINT);
597}
598
599/*		Generic part			*/
600
601/* DMA ENGINE functions */
602static void nbpf_issue_pending(struct dma_chan *dchan)
603{
604	struct nbpf_channel *chan = nbpf_to_chan(dchan);
605	unsigned long flags;
606
607	dev_dbg(dchan->device->dev, "Entry %s()\n", __func__);
608
609	spin_lock_irqsave(&chan->lock, flags);
610	if (list_empty(&chan->queued))
611		goto unlock;
612
613	list_splice_tail_init(&chan->queued, &chan->active);
614
615	if (!chan->running) {
616		struct nbpf_desc *desc = list_first_entry(&chan->active,
617						struct nbpf_desc, node);
618		if (!nbpf_start(desc))
619			chan->running = desc;
620	}
621
622unlock:
623	spin_unlock_irqrestore(&chan->lock, flags);
624}
625
626static enum dma_status nbpf_tx_status(struct dma_chan *dchan,
627		dma_cookie_t cookie, struct dma_tx_state *state)
628{
629	struct nbpf_channel *chan = nbpf_to_chan(dchan);
630	enum dma_status status = dma_cookie_status(dchan, cookie, state);
631
632	if (state) {
633		dma_cookie_t running;
634		unsigned long flags;
635
636		spin_lock_irqsave(&chan->lock, flags);
637		running = chan->running ? chan->running->async_tx.cookie : -EINVAL;
638
639		if (cookie == running) {
640			state->residue = nbpf_bytes_left(chan);
641			dev_dbg(dchan->device->dev, "%s(): residue %u\n", __func__,
642				state->residue);
643		} else if (status == DMA_IN_PROGRESS) {
644			struct nbpf_desc *desc;
645			bool found = false;
646
647			list_for_each_entry(desc, &chan->active, node)
648				if (desc->async_tx.cookie == cookie) {
649					found = true;
650					break;
651				}
652
653			if (!found)
654				list_for_each_entry(desc, &chan->queued, node)
655					if (desc->async_tx.cookie == cookie) {
656						found = true;
657						break;
658
659					}
660
661			state->residue = found ? desc->length : 0;
662		}
663
664		spin_unlock_irqrestore(&chan->lock, flags);
665	}
666
667	if (chan->paused)
668		status = DMA_PAUSED;
669
670	return status;
671}
672
673static dma_cookie_t nbpf_tx_submit(struct dma_async_tx_descriptor *tx)
674{
675	struct nbpf_desc *desc = container_of(tx, struct nbpf_desc, async_tx);
676	struct nbpf_channel *chan = desc->chan;
677	unsigned long flags;
678	dma_cookie_t cookie;
679
680	spin_lock_irqsave(&chan->lock, flags);
681	cookie = dma_cookie_assign(tx);
682	list_add_tail(&desc->node, &chan->queued);
683	spin_unlock_irqrestore(&chan->lock, flags);
684
685	dev_dbg(chan->dma_chan.device->dev, "Entry %s(%d)\n", __func__, cookie);
686
687	return cookie;
688}
689
690static int nbpf_desc_page_alloc(struct nbpf_channel *chan)
691{
692	struct dma_chan *dchan = &chan->dma_chan;
693	struct nbpf_desc_page *dpage = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
694	struct nbpf_link_desc *ldesc;
695	struct nbpf_link_reg *hwdesc;
696	struct nbpf_desc *desc;
697	LIST_HEAD(head);
698	LIST_HEAD(lhead);
699	int i;
700	struct device *dev = dchan->device->dev;
701
702	if (!dpage)
703		return -ENOMEM;
704
705	dev_dbg(dev, "%s(): alloc %lu descriptors, %lu segments, total alloc %zu\n",
706		__func__, NBPF_DESCS_PER_PAGE, NBPF_SEGMENTS_PER_PAGE, sizeof(*dpage));
707
708	for (i = 0, ldesc = dpage->ldesc, hwdesc = dpage->hwdesc;
709	     i < ARRAY_SIZE(dpage->ldesc);
710	     i++, ldesc++, hwdesc++) {
711		ldesc->hwdesc = hwdesc;
712		list_add_tail(&ldesc->node, &lhead);
713		ldesc->hwdesc_dma_addr = dma_map_single(dchan->device->dev,
714					hwdesc, sizeof(*hwdesc), DMA_TO_DEVICE);
715
716		dev_dbg(dev, "%s(): mapped 0x%p to %pad\n", __func__,
717			hwdesc, &ldesc->hwdesc_dma_addr);
718	}
719
720	for (i = 0, desc = dpage->desc;
721	     i < ARRAY_SIZE(dpage->desc);
722	     i++, desc++) {
723		dma_async_tx_descriptor_init(&desc->async_tx, dchan);
724		desc->async_tx.tx_submit = nbpf_tx_submit;
725		desc->chan = chan;
726		INIT_LIST_HEAD(&desc->sg);
727		list_add_tail(&desc->node, &head);
728	}
729
730	/*
731	 * This function cannot be called from interrupt context, so, no need to
732	 * save flags
733	 */
734	spin_lock_irq(&chan->lock);
735	list_splice_tail(&lhead, &chan->free_links);
736	list_splice_tail(&head, &chan->free);
737	list_add(&dpage->node, &chan->desc_page);
738	spin_unlock_irq(&chan->lock);
739
740	return ARRAY_SIZE(dpage->desc);
741}
742
743static void nbpf_desc_put(struct nbpf_desc *desc)
744{
745	struct nbpf_channel *chan = desc->chan;
746	struct nbpf_link_desc *ldesc, *tmp;
747	unsigned long flags;
748
749	spin_lock_irqsave(&chan->lock, flags);
750	list_for_each_entry_safe(ldesc, tmp, &desc->sg, node)
751		list_move(&ldesc->node, &chan->free_links);
752
753	list_add(&desc->node, &chan->free);
754	spin_unlock_irqrestore(&chan->lock, flags);
755}
756
757static void nbpf_scan_acked(struct nbpf_channel *chan)
758{
759	struct nbpf_desc *desc, *tmp;
760	unsigned long flags;
761	LIST_HEAD(head);
762
763	spin_lock_irqsave(&chan->lock, flags);
764	list_for_each_entry_safe(desc, tmp, &chan->done, node)
765		if (async_tx_test_ack(&desc->async_tx) && desc->user_wait) {
766			list_move(&desc->node, &head);
767			desc->user_wait = false;
768		}
769	spin_unlock_irqrestore(&chan->lock, flags);
770
771	list_for_each_entry_safe(desc, tmp, &head, node) {
772		list_del(&desc->node);
773		nbpf_desc_put(desc);
774	}
775}
776
777/*
778 * We have to allocate descriptors with the channel lock dropped. This means,
779 * before we re-acquire the lock buffers can be taken already, so we have to
780 * re-check after re-acquiring the lock and possibly retry, if buffers are gone
781 * again.
782 */
783static struct nbpf_desc *nbpf_desc_get(struct nbpf_channel *chan, size_t len)
784{
785	struct nbpf_desc *desc = NULL;
786	struct nbpf_link_desc *ldesc, *prev = NULL;
787
788	nbpf_scan_acked(chan);
789
790	spin_lock_irq(&chan->lock);
791
792	do {
793		int i = 0, ret;
794
795		if (list_empty(&chan->free)) {
796			/* No more free descriptors */
797			spin_unlock_irq(&chan->lock);
798			ret = nbpf_desc_page_alloc(chan);
799			if (ret < 0)
800				return NULL;
801			spin_lock_irq(&chan->lock);
802			continue;
803		}
804		desc = list_first_entry(&chan->free, struct nbpf_desc, node);
805		list_del(&desc->node);
806
807		do {
808			if (list_empty(&chan->free_links)) {
809				/* No more free link descriptors */
810				spin_unlock_irq(&chan->lock);
811				ret = nbpf_desc_page_alloc(chan);
812				if (ret < 0) {
813					nbpf_desc_put(desc);
814					return NULL;
815				}
816				spin_lock_irq(&chan->lock);
817				continue;
818			}
819
820			ldesc = list_first_entry(&chan->free_links,
821						 struct nbpf_link_desc, node);
822			ldesc->desc = desc;
823			if (prev)
824				prev->hwdesc->next = (u32)ldesc->hwdesc_dma_addr;
825
826			prev = ldesc;
827			list_move_tail(&ldesc->node, &desc->sg);
828
829			i++;
830		} while (i < len);
831	} while (!desc);
832
833	prev->hwdesc->next = 0;
834
835	spin_unlock_irq(&chan->lock);
836
837	return desc;
838}
839
840static void nbpf_chan_idle(struct nbpf_channel *chan)
841{
842	struct nbpf_desc *desc, *tmp;
843	unsigned long flags;
844	LIST_HEAD(head);
845
846	spin_lock_irqsave(&chan->lock, flags);
847
848	list_splice_init(&chan->done, &head);
849	list_splice_init(&chan->active, &head);
850	list_splice_init(&chan->queued, &head);
851
852	chan->running = NULL;
853
854	spin_unlock_irqrestore(&chan->lock, flags);
855
856	list_for_each_entry_safe(desc, tmp, &head, node) {
857		dev_dbg(chan->nbpf->dma_dev.dev, "%s(): force-free desc %p cookie %d\n",
858			__func__, desc, desc->async_tx.cookie);
859		list_del(&desc->node);
860		nbpf_desc_put(desc);
861	}
862}
863
864static int nbpf_pause(struct dma_chan *dchan)
865{
866	struct nbpf_channel *chan = nbpf_to_chan(dchan);
867
868	dev_dbg(dchan->device->dev, "Entry %s\n", __func__);
869
870	chan->paused = true;
871	nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_SETSUS);
872	/* See comment in nbpf_prep_one() */
873	nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_CLREN);
874
875	return 0;
876}
877
878static int nbpf_terminate_all(struct dma_chan *dchan)
879{
880	struct nbpf_channel *chan = nbpf_to_chan(dchan);
881
882	dev_dbg(dchan->device->dev, "Entry %s\n", __func__);
883	dev_dbg(dchan->device->dev, "Terminating\n");
884
885	nbpf_chan_halt(chan);
886	nbpf_chan_idle(chan);
887
888	return 0;
889}
890
891static int nbpf_config(struct dma_chan *dchan,
892		       struct dma_slave_config *config)
893{
894	struct nbpf_channel *chan = nbpf_to_chan(dchan);
895
896	dev_dbg(dchan->device->dev, "Entry %s\n", __func__);
897
898	/*
899	 * We could check config->slave_id to match chan->terminal here,
900	 * but with DT they would be coming from the same source, so
901	 * such a check would be superflous
902	 */
903
904	chan->slave_dst_addr = config->dst_addr;
905	chan->slave_dst_width = nbpf_xfer_size(chan->nbpf,
906					       config->dst_addr_width, 1);
907	chan->slave_dst_burst = nbpf_xfer_size(chan->nbpf,
908					       config->dst_addr_width,
909					       config->dst_maxburst);
910	chan->slave_src_addr = config->src_addr;
911	chan->slave_src_width = nbpf_xfer_size(chan->nbpf,
912					       config->src_addr_width, 1);
913	chan->slave_src_burst = nbpf_xfer_size(chan->nbpf,
914					       config->src_addr_width,
915					       config->src_maxburst);
916
917	return 0;
918}
919
920static struct dma_async_tx_descriptor *nbpf_prep_sg(struct nbpf_channel *chan,
921		struct scatterlist *src_sg, struct scatterlist *dst_sg,
922		size_t len, enum dma_transfer_direction direction,
923		unsigned long flags)
924{
925	struct nbpf_link_desc *ldesc;
926	struct scatterlist *mem_sg;
927	struct nbpf_desc *desc;
928	bool inc_src, inc_dst;
929	size_t data_len = 0;
930	int i = 0;
931
932	switch (direction) {
933	case DMA_DEV_TO_MEM:
934		mem_sg = dst_sg;
935		inc_src = false;
936		inc_dst = true;
937		break;
938
939	case DMA_MEM_TO_DEV:
940		mem_sg = src_sg;
941		inc_src = true;
942		inc_dst = false;
943		break;
944
945	default:
946	case DMA_MEM_TO_MEM:
947		mem_sg = src_sg;
948		inc_src = true;
949		inc_dst = true;
950	}
951
952	desc = nbpf_desc_get(chan, len);
953	if (!desc)
954		return NULL;
955
956	desc->async_tx.flags = flags;
957	desc->async_tx.cookie = -EBUSY;
958	desc->user_wait = false;
959
960	/*
961	 * This is a private descriptor list, and we own the descriptor. No need
962	 * to lock.
963	 */
964	list_for_each_entry(ldesc, &desc->sg, node) {
965		int ret = nbpf_prep_one(ldesc, direction,
966					sg_dma_address(src_sg),
967					sg_dma_address(dst_sg),
968					sg_dma_len(mem_sg),
969					i == len - 1);
970		if (ret < 0) {
971			nbpf_desc_put(desc);
972			return NULL;
973		}
974		data_len += sg_dma_len(mem_sg);
975		if (inc_src)
976			src_sg = sg_next(src_sg);
977		if (inc_dst)
978			dst_sg = sg_next(dst_sg);
979		mem_sg = direction == DMA_DEV_TO_MEM ? dst_sg : src_sg;
980		i++;
981	}
982
983	desc->length = data_len;
984
985	/* The user has to return the descriptor to us ASAP via .tx_submit() */
986	return &desc->async_tx;
987}
988
989static struct dma_async_tx_descriptor *nbpf_prep_memcpy(
990	struct dma_chan *dchan, dma_addr_t dst, dma_addr_t src,
991	size_t len, unsigned long flags)
992{
993	struct nbpf_channel *chan = nbpf_to_chan(dchan);
994	struct scatterlist dst_sg;
995	struct scatterlist src_sg;
996
997	sg_init_table(&dst_sg, 1);
998	sg_init_table(&src_sg, 1);
999
1000	sg_dma_address(&dst_sg) = dst;
1001	sg_dma_address(&src_sg) = src;
1002
1003	sg_dma_len(&dst_sg) = len;
1004	sg_dma_len(&src_sg) = len;
1005
1006	dev_dbg(dchan->device->dev, "%s(): %zu @ %pad -> %pad\n",
1007		__func__, len, &src, &dst);
1008
1009	return nbpf_prep_sg(chan, &src_sg, &dst_sg, 1,
1010			    DMA_MEM_TO_MEM, flags);
1011}
1012
1013static struct dma_async_tx_descriptor *nbpf_prep_slave_sg(
1014	struct dma_chan *dchan, struct scatterlist *sgl, unsigned int sg_len,
1015	enum dma_transfer_direction direction, unsigned long flags, void *context)
1016{
1017	struct nbpf_channel *chan = nbpf_to_chan(dchan);
1018	struct scatterlist slave_sg;
1019
1020	dev_dbg(dchan->device->dev, "Entry %s()\n", __func__);
1021
1022	sg_init_table(&slave_sg, 1);
1023
1024	switch (direction) {
1025	case DMA_MEM_TO_DEV:
1026		sg_dma_address(&slave_sg) = chan->slave_dst_addr;
1027		return nbpf_prep_sg(chan, sgl, &slave_sg, sg_len,
1028				    direction, flags);
1029
1030	case DMA_DEV_TO_MEM:
1031		sg_dma_address(&slave_sg) = chan->slave_src_addr;
1032		return nbpf_prep_sg(chan, &slave_sg, sgl, sg_len,
1033				    direction, flags);
1034
1035	default:
1036		return NULL;
1037	}
1038}
1039
1040static int nbpf_alloc_chan_resources(struct dma_chan *dchan)
1041{
1042	struct nbpf_channel *chan = nbpf_to_chan(dchan);
1043	int ret;
1044
1045	INIT_LIST_HEAD(&chan->free);
1046	INIT_LIST_HEAD(&chan->free_links);
1047	INIT_LIST_HEAD(&chan->queued);
1048	INIT_LIST_HEAD(&chan->active);
1049	INIT_LIST_HEAD(&chan->done);
1050
1051	ret = nbpf_desc_page_alloc(chan);
1052	if (ret < 0)
1053		return ret;
1054
1055	dev_dbg(dchan->device->dev, "Entry %s(): terminal %u\n", __func__,
1056		chan->terminal);
1057
1058	nbpf_chan_configure(chan);
1059
1060	return ret;
1061}
1062
1063static void nbpf_free_chan_resources(struct dma_chan *dchan)
1064{
1065	struct nbpf_channel *chan = nbpf_to_chan(dchan);
1066	struct nbpf_desc_page *dpage, *tmp;
1067
1068	dev_dbg(dchan->device->dev, "Entry %s()\n", __func__);
1069
1070	nbpf_chan_halt(chan);
1071	nbpf_chan_idle(chan);
1072	/* Clean up for if a channel is re-used for MEMCPY after slave DMA */
1073	nbpf_chan_prepare_default(chan);
1074
1075	list_for_each_entry_safe(dpage, tmp, &chan->desc_page, node) {
1076		struct nbpf_link_desc *ldesc;
1077		int i;
1078		list_del(&dpage->node);
1079		for (i = 0, ldesc = dpage->ldesc;
1080		     i < ARRAY_SIZE(dpage->ldesc);
1081		     i++, ldesc++)
1082			dma_unmap_single(dchan->device->dev, ldesc->hwdesc_dma_addr,
1083					 sizeof(*ldesc->hwdesc), DMA_TO_DEVICE);
1084		free_page((unsigned long)dpage);
1085	}
1086}
1087
1088static struct dma_chan *nbpf_of_xlate(struct of_phandle_args *dma_spec,
1089				      struct of_dma *ofdma)
1090{
1091	struct nbpf_device *nbpf = ofdma->of_dma_data;
1092	struct dma_chan *dchan;
1093	struct nbpf_channel *chan;
1094
1095	if (dma_spec->args_count != 2)
1096		return NULL;
1097
1098	dchan = dma_get_any_slave_channel(&nbpf->dma_dev);
1099	if (!dchan)
1100		return NULL;
1101
1102	dev_dbg(dchan->device->dev, "Entry %s(%pOFn)\n", __func__,
1103		dma_spec->np);
1104
1105	chan = nbpf_to_chan(dchan);
1106
1107	chan->terminal = dma_spec->args[0];
1108	chan->flags = dma_spec->args[1];
1109
1110	nbpf_chan_prepare(chan);
1111	nbpf_chan_configure(chan);
1112
1113	return dchan;
1114}
1115
1116static void nbpf_chan_tasklet(struct tasklet_struct *t)
1117{
1118	struct nbpf_channel *chan = from_tasklet(chan, t, tasklet);
1119	struct nbpf_desc *desc, *tmp;
1120	struct dmaengine_desc_callback cb;
1121
1122	while (!list_empty(&chan->done)) {
1123		bool found = false, must_put, recycling = false;
1124
1125		spin_lock_irq(&chan->lock);
1126
1127		list_for_each_entry_safe(desc, tmp, &chan->done, node) {
1128			if (!desc->user_wait) {
1129				/* Newly completed descriptor, have to process */
1130				found = true;
1131				break;
1132			} else if (async_tx_test_ack(&desc->async_tx)) {
1133				/*
1134				 * This descriptor was waiting for a user ACK,
1135				 * it can be recycled now.
1136				 */
1137				list_del(&desc->node);
1138				spin_unlock_irq(&chan->lock);
1139				nbpf_desc_put(desc);
1140				recycling = true;
1141				break;
1142			}
1143		}
1144
1145		if (recycling)
1146			continue;
1147
1148		if (!found) {
1149			/* This can happen if TERMINATE_ALL has been called */
1150			spin_unlock_irq(&chan->lock);
1151			break;
1152		}
1153
1154		dma_cookie_complete(&desc->async_tx);
1155
1156		/*
1157		 * With released lock we cannot dereference desc, maybe it's
1158		 * still on the "done" list
1159		 */
1160		if (async_tx_test_ack(&desc->async_tx)) {
1161			list_del(&desc->node);
1162			must_put = true;
1163		} else {
1164			desc->user_wait = true;
1165			must_put = false;
1166		}
1167
1168		dmaengine_desc_get_callback(&desc->async_tx, &cb);
1169
1170		/* ack and callback completed descriptor */
1171		spin_unlock_irq(&chan->lock);
1172
1173		dmaengine_desc_callback_invoke(&cb, NULL);
1174
1175		if (must_put)
1176			nbpf_desc_put(desc);
1177	}
1178}
1179
1180static irqreturn_t nbpf_chan_irq(int irq, void *dev)
1181{
1182	struct nbpf_channel *chan = dev;
1183	bool done = nbpf_status_get(chan);
1184	struct nbpf_desc *desc;
1185	irqreturn_t ret;
1186	bool bh = false;
1187
1188	if (!done)
1189		return IRQ_NONE;
1190
1191	nbpf_status_ack(chan);
1192
1193	dev_dbg(&chan->dma_chan.dev->device, "%s()\n", __func__);
1194
1195	spin_lock(&chan->lock);
1196	desc = chan->running;
1197	if (WARN_ON(!desc)) {
1198		ret = IRQ_NONE;
1199		goto unlock;
1200	} else {
1201		ret = IRQ_HANDLED;
1202		bh = true;
1203	}
1204
1205	list_move_tail(&desc->node, &chan->done);
1206	chan->running = NULL;
1207
1208	if (!list_empty(&chan->active)) {
1209		desc = list_first_entry(&chan->active,
1210					struct nbpf_desc, node);
1211		if (!nbpf_start(desc))
1212			chan->running = desc;
1213	}
1214
1215unlock:
1216	spin_unlock(&chan->lock);
1217
1218	if (bh)
1219		tasklet_schedule(&chan->tasklet);
1220
1221	return ret;
1222}
1223
1224static irqreturn_t nbpf_err_irq(int irq, void *dev)
1225{
1226	struct nbpf_device *nbpf = dev;
1227	u32 error = nbpf_error_get(nbpf);
1228
1229	dev_warn(nbpf->dma_dev.dev, "DMA error IRQ %u\n", irq);
1230
1231	if (!error)
1232		return IRQ_NONE;
1233
1234	do {
1235		struct nbpf_channel *chan = nbpf_error_get_channel(nbpf, error);
1236		/* On error: abort all queued transfers, no callback */
1237		nbpf_error_clear(chan);
1238		nbpf_chan_idle(chan);
1239		error = nbpf_error_get(nbpf);
1240	} while (error);
1241
1242	return IRQ_HANDLED;
1243}
1244
1245static int nbpf_chan_probe(struct nbpf_device *nbpf, int n)
1246{
1247	struct dma_device *dma_dev = &nbpf->dma_dev;
1248	struct nbpf_channel *chan = nbpf->chan + n;
1249	int ret;
1250
1251	chan->nbpf = nbpf;
1252	chan->base = nbpf->base + NBPF_REG_CHAN_OFFSET + NBPF_REG_CHAN_SIZE * n;
1253	INIT_LIST_HEAD(&chan->desc_page);
1254	spin_lock_init(&chan->lock);
1255	chan->dma_chan.device = dma_dev;
1256	dma_cookie_init(&chan->dma_chan);
1257	nbpf_chan_prepare_default(chan);
1258
1259	dev_dbg(dma_dev->dev, "%s(): channel %d: -> %p\n", __func__, n, chan->base);
1260
1261	snprintf(chan->name, sizeof(chan->name), "nbpf %d", n);
1262
1263	tasklet_setup(&chan->tasklet, nbpf_chan_tasklet);
1264	ret = devm_request_irq(dma_dev->dev, chan->irq,
1265			nbpf_chan_irq, IRQF_SHARED,
1266			chan->name, chan);
1267	if (ret < 0)
1268		return ret;
1269
1270	/* Add the channel to DMA device channel list */
1271	list_add_tail(&chan->dma_chan.device_node,
1272		      &dma_dev->channels);
1273
1274	return 0;
1275}
1276
1277static const struct of_device_id nbpf_match[] = {
1278	{.compatible = "renesas,nbpfaxi64dmac1b4",	.data = &nbpf_cfg[NBPF1B4]},
1279	{.compatible = "renesas,nbpfaxi64dmac1b8",	.data = &nbpf_cfg[NBPF1B8]},
1280	{.compatible = "renesas,nbpfaxi64dmac1b16",	.data = &nbpf_cfg[NBPF1B16]},
1281	{.compatible = "renesas,nbpfaxi64dmac4b4",	.data = &nbpf_cfg[NBPF4B4]},
1282	{.compatible = "renesas,nbpfaxi64dmac4b8",	.data = &nbpf_cfg[NBPF4B8]},
1283	{.compatible = "renesas,nbpfaxi64dmac4b16",	.data = &nbpf_cfg[NBPF4B16]},
1284	{.compatible = "renesas,nbpfaxi64dmac8b4",	.data = &nbpf_cfg[NBPF8B4]},
1285	{.compatible = "renesas,nbpfaxi64dmac8b8",	.data = &nbpf_cfg[NBPF8B8]},
1286	{.compatible = "renesas,nbpfaxi64dmac8b16",	.data = &nbpf_cfg[NBPF8B16]},
1287	{}
1288};
1289MODULE_DEVICE_TABLE(of, nbpf_match);
1290
1291static int nbpf_probe(struct platform_device *pdev)
1292{
1293	struct device *dev = &pdev->dev;
1294	struct device_node *np = dev->of_node;
1295	struct nbpf_device *nbpf;
1296	struct dma_device *dma_dev;
1297	struct resource *iomem, *irq_res;
1298	const struct nbpf_config *cfg;
1299	int num_channels;
1300	int ret, irq, eirq, i;
1301	int irqbuf[9] /* maximum 8 channels + error IRQ */;
1302	unsigned int irqs = 0;
1303
1304	BUILD_BUG_ON(sizeof(struct nbpf_desc_page) > PAGE_SIZE);
1305
1306	/* DT only */
1307	if (!np)
1308		return -ENODEV;
1309
1310	cfg = of_device_get_match_data(dev);
1311	num_channels = cfg->num_channels;
1312
1313	nbpf = devm_kzalloc(dev, struct_size(nbpf, chan, num_channels),
1314			    GFP_KERNEL);
1315	if (!nbpf)
1316		return -ENOMEM;
1317
1318	dma_dev = &nbpf->dma_dev;
1319	dma_dev->dev = dev;
1320
1321	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1322	nbpf->base = devm_ioremap_resource(dev, iomem);
1323	if (IS_ERR(nbpf->base))
1324		return PTR_ERR(nbpf->base);
1325
1326	nbpf->clk = devm_clk_get(dev, NULL);
1327	if (IS_ERR(nbpf->clk))
1328		return PTR_ERR(nbpf->clk);
1329
1330	of_property_read_u32(np, "max-burst-mem-read",
1331			     &nbpf->max_burst_mem_read);
1332	of_property_read_u32(np, "max-burst-mem-write",
1333			     &nbpf->max_burst_mem_write);
1334
1335	nbpf->config = cfg;
1336
1337	for (i = 0; irqs < ARRAY_SIZE(irqbuf); i++) {
1338		irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
1339		if (!irq_res)
1340			break;
1341
1342		for (irq = irq_res->start; irq <= irq_res->end;
1343		     irq++, irqs++)
1344			irqbuf[irqs] = irq;
1345	}
1346
1347	/*
1348	 * 3 IRQ resource schemes are supported:
1349	 * 1. 1 shared IRQ for error and all channels
1350	 * 2. 2 IRQs: one for error and one shared for all channels
1351	 * 3. 1 IRQ for error and an own IRQ for each channel
1352	 */
1353	if (irqs != 1 && irqs != 2 && irqs != num_channels + 1)
1354		return -ENXIO;
1355
1356	if (irqs == 1) {
1357		eirq = irqbuf[0];
1358
1359		for (i = 0; i <= num_channels; i++)
1360			nbpf->chan[i].irq = irqbuf[0];
1361	} else {
1362		eirq = platform_get_irq_byname(pdev, "error");
1363		if (eirq < 0)
1364			return eirq;
1365
1366		if (irqs == num_channels + 1) {
1367			struct nbpf_channel *chan;
1368
1369			for (i = 0, chan = nbpf->chan; i <= num_channels;
1370			     i++, chan++) {
1371				/* Skip the error IRQ */
1372				if (irqbuf[i] == eirq)
1373					i++;
1374				chan->irq = irqbuf[i];
1375			}
1376
1377			if (chan != nbpf->chan + num_channels)
1378				return -EINVAL;
1379		} else {
1380			/* 2 IRQs and more than one channel */
1381			if (irqbuf[0] == eirq)
1382				irq = irqbuf[1];
1383			else
1384				irq = irqbuf[0];
1385
1386			for (i = 0; i <= num_channels; i++)
1387				nbpf->chan[i].irq = irq;
1388		}
1389	}
1390
1391	ret = devm_request_irq(dev, eirq, nbpf_err_irq,
1392			       IRQF_SHARED, "dma error", nbpf);
1393	if (ret < 0)
1394		return ret;
1395	nbpf->eirq = eirq;
1396
1397	INIT_LIST_HEAD(&dma_dev->channels);
1398
1399	/* Create DMA Channel */
1400	for (i = 0; i < num_channels; i++) {
1401		ret = nbpf_chan_probe(nbpf, i);
1402		if (ret < 0)
1403			return ret;
1404	}
1405
1406	dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
1407	dma_cap_set(DMA_SLAVE, dma_dev->cap_mask);
1408	dma_cap_set(DMA_PRIVATE, dma_dev->cap_mask);
1409
1410	/* Common and MEMCPY operations */
1411	dma_dev->device_alloc_chan_resources
1412		= nbpf_alloc_chan_resources;
1413	dma_dev->device_free_chan_resources = nbpf_free_chan_resources;
1414	dma_dev->device_prep_dma_memcpy = nbpf_prep_memcpy;
1415	dma_dev->device_tx_status = nbpf_tx_status;
1416	dma_dev->device_issue_pending = nbpf_issue_pending;
1417
1418	/*
1419	 * If we drop support for unaligned MEMCPY buffer addresses and / or
1420	 * lengths by setting
1421	 * dma_dev->copy_align = 4;
1422	 * then we can set transfer length to 4 bytes in nbpf_prep_one() for
1423	 * DMA_MEM_TO_MEM
1424	 */
1425
1426	/* Compulsory for DMA_SLAVE fields */
1427	dma_dev->device_prep_slave_sg = nbpf_prep_slave_sg;
1428	dma_dev->device_config = nbpf_config;
1429	dma_dev->device_pause = nbpf_pause;
1430	dma_dev->device_terminate_all = nbpf_terminate_all;
1431
1432	dma_dev->src_addr_widths = NBPF_DMA_BUSWIDTHS;
1433	dma_dev->dst_addr_widths = NBPF_DMA_BUSWIDTHS;
1434	dma_dev->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1435
1436	platform_set_drvdata(pdev, nbpf);
1437
1438	ret = clk_prepare_enable(nbpf->clk);
1439	if (ret < 0)
1440		return ret;
1441
1442	nbpf_configure(nbpf);
1443
1444	ret = dma_async_device_register(dma_dev);
1445	if (ret < 0)
1446		goto e_clk_off;
1447
1448	ret = of_dma_controller_register(np, nbpf_of_xlate, nbpf);
1449	if (ret < 0)
1450		goto e_dma_dev_unreg;
1451
1452	return 0;
1453
1454e_dma_dev_unreg:
1455	dma_async_device_unregister(dma_dev);
1456e_clk_off:
1457	clk_disable_unprepare(nbpf->clk);
1458
1459	return ret;
1460}
1461
1462static int nbpf_remove(struct platform_device *pdev)
1463{
1464	struct nbpf_device *nbpf = platform_get_drvdata(pdev);
1465	int i;
1466
1467	devm_free_irq(&pdev->dev, nbpf->eirq, nbpf);
1468
1469	for (i = 0; i < nbpf->config->num_channels; i++) {
1470		struct nbpf_channel *chan = nbpf->chan + i;
1471
1472		devm_free_irq(&pdev->dev, chan->irq, chan);
1473
1474		tasklet_kill(&chan->tasklet);
1475	}
1476
1477	of_dma_controller_free(pdev->dev.of_node);
1478	dma_async_device_unregister(&nbpf->dma_dev);
1479	clk_disable_unprepare(nbpf->clk);
1480
1481	return 0;
1482}
1483
1484static const struct platform_device_id nbpf_ids[] = {
1485	{"nbpfaxi64dmac1b4",	(kernel_ulong_t)&nbpf_cfg[NBPF1B4]},
1486	{"nbpfaxi64dmac1b8",	(kernel_ulong_t)&nbpf_cfg[NBPF1B8]},
1487	{"nbpfaxi64dmac1b16",	(kernel_ulong_t)&nbpf_cfg[NBPF1B16]},
1488	{"nbpfaxi64dmac4b4",	(kernel_ulong_t)&nbpf_cfg[NBPF4B4]},
1489	{"nbpfaxi64dmac4b8",	(kernel_ulong_t)&nbpf_cfg[NBPF4B8]},
1490	{"nbpfaxi64dmac4b16",	(kernel_ulong_t)&nbpf_cfg[NBPF4B16]},
1491	{"nbpfaxi64dmac8b4",	(kernel_ulong_t)&nbpf_cfg[NBPF8B4]},
1492	{"nbpfaxi64dmac8b8",	(kernel_ulong_t)&nbpf_cfg[NBPF8B8]},
1493	{"nbpfaxi64dmac8b16",	(kernel_ulong_t)&nbpf_cfg[NBPF8B16]},
1494	{},
1495};
1496MODULE_DEVICE_TABLE(platform, nbpf_ids);
1497
1498#ifdef CONFIG_PM
1499static int nbpf_runtime_suspend(struct device *dev)
1500{
1501	struct nbpf_device *nbpf = dev_get_drvdata(dev);
1502	clk_disable_unprepare(nbpf->clk);
1503	return 0;
1504}
1505
1506static int nbpf_runtime_resume(struct device *dev)
1507{
1508	struct nbpf_device *nbpf = dev_get_drvdata(dev);
1509	return clk_prepare_enable(nbpf->clk);
1510}
1511#endif
1512
1513static const struct dev_pm_ops nbpf_pm_ops = {
1514	SET_RUNTIME_PM_OPS(nbpf_runtime_suspend, nbpf_runtime_resume, NULL)
1515};
1516
1517static struct platform_driver nbpf_driver = {
1518	.driver = {
1519		.name = "dma-nbpf",
1520		.of_match_table = nbpf_match,
1521		.pm = &nbpf_pm_ops,
1522	},
1523	.id_table = nbpf_ids,
1524	.probe = nbpf_probe,
1525	.remove = nbpf_remove,
1526};
1527
1528module_platform_driver(nbpf_driver);
1529
1530MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>");
1531MODULE_DESCRIPTION("dmaengine driver for NBPFAXI64* DMACs");
1532MODULE_LICENSE("GPL v2");
1533