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