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
98 struct 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
120 struct 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
131 struct nbpf_device;
132 struct nbpf_channel;
133 struct nbpf_desc;
134
135 struct 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 */
151 struct 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
168 struct 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 */
202 struct 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
229 struct 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
240 enum nbpf_model {
241 NBPF1B4,
242 NBPF1B8,
243 NBPF1B16,
244 NBPF4B4,
245 NBPF4B8,
246 NBPF4B16,
247 NBPF8B4,
248 NBPF8B8,
249 NBPF8B16,
250 };
251
252 static 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
nbpf_chan_read(struct nbpf_channel * chan,unsigned int offset)305 static 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
nbpf_chan_write(struct nbpf_channel * chan,unsigned int offset,u32 data)314 static 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
nbpf_read(struct nbpf_device * nbpf,unsigned int offset)322 static 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
nbpf_write(struct nbpf_device * nbpf,unsigned int offset,u32 data)331 static 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
nbpf_chan_halt(struct nbpf_channel * chan)339 static void nbpf_chan_halt(struct nbpf_channel *chan)
340 {
341 nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_CLREN);
342 }
343
nbpf_status_get(struct nbpf_channel * chan)344 static 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
nbpf_status_ack(struct nbpf_channel * chan)351 static void nbpf_status_ack(struct nbpf_channel *chan)
352 {
353 nbpf_chan_write(chan, NBPF_CHAN_CTRL, NBPF_CHAN_CTRL_CLREND);
354 }
355
nbpf_error_get(struct nbpf_device * nbpf)356 static u32 nbpf_error_get(struct nbpf_device *nbpf)
357 {
358 return nbpf_read(nbpf, NBPF_DSTAT_ER);
359 }
360
nbpf_error_get_channel(struct nbpf_device * nbpf,u32 error)361 static struct nbpf_channel *nbpf_error_get_channel(struct nbpf_device *nbpf, u32 error)
362 {
363 return nbpf->chan + __ffs(error);
364 }
365
nbpf_error_clear(struct nbpf_channel * chan)366 static 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
nbpf_start(struct nbpf_desc * desc)388 static 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
nbpf_chan_prepare(struct nbpf_channel * chan)407 static 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
nbpf_chan_prepare_default(struct nbpf_channel * chan)416 static 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
nbpf_chan_configure(struct nbpf_channel * chan)424 static 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
nbpf_xfer_ds(struct nbpf_device * nbpf,size_t size,enum dma_transfer_direction direction)434 static 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
nbpf_xfer_size(struct nbpf_device * nbpf,enum dma_slave_buswidth width,u32 burst)463 static 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
nbpf_prep_one(struct nbpf_link_desc * ldesc,enum dma_transfer_direction direction,dma_addr_t src,dma_addr_t dst,size_t size,bool last)506 static 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
nbpf_bytes_left(struct nbpf_channel * chan)589 static size_t nbpf_bytes_left(struct nbpf_channel *chan)
590 {
591 return nbpf_chan_read(chan, NBPF_CHAN_CUR_TR_BYTE);
592 }
593
nbpf_configure(struct nbpf_device * nbpf)594 static 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 */
nbpf_issue_pending(struct dma_chan * dchan)602 static 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
622 unlock:
623 spin_unlock_irqrestore(&chan->lock, flags);
624 }
625
nbpf_tx_status(struct dma_chan * dchan,dma_cookie_t cookie,struct dma_tx_state * state)626 static 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
nbpf_tx_submit(struct dma_async_tx_descriptor * tx)673 static 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
nbpf_desc_page_alloc(struct nbpf_channel * chan)690 static 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
nbpf_desc_put(struct nbpf_desc * desc)743 static 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
nbpf_scan_acked(struct nbpf_channel * chan)757 static 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 */
nbpf_desc_get(struct nbpf_channel * chan,size_t len)783 static 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
nbpf_chan_idle(struct nbpf_channel * chan)840 static 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
nbpf_pause(struct dma_chan * dchan)864 static 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
nbpf_terminate_all(struct dma_chan * dchan)878 static 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
nbpf_config(struct dma_chan * dchan,struct dma_slave_config * config)891 static 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
nbpf_prep_sg(struct nbpf_channel * chan,struct scatterlist * src_sg,struct scatterlist * dst_sg,size_t len,enum dma_transfer_direction direction,unsigned long flags)920 static 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
nbpf_prep_memcpy(struct dma_chan * dchan,dma_addr_t dst,dma_addr_t src,size_t len,unsigned long flags)989 static 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
nbpf_prep_slave_sg(struct dma_chan * dchan,struct scatterlist * sgl,unsigned int sg_len,enum dma_transfer_direction direction,unsigned long flags,void * context)1013 static 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
nbpf_alloc_chan_resources(struct dma_chan * dchan)1040 static 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
nbpf_free_chan_resources(struct dma_chan * dchan)1063 static 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
nbpf_of_xlate(struct of_phandle_args * dma_spec,struct of_dma * ofdma)1088 static 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
nbpf_chan_tasklet(struct tasklet_struct * t)1116 static 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
nbpf_chan_irq(int irq,void * dev)1180 static 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
1215 unlock:
1216 spin_unlock(&chan->lock);
1217
1218 if (bh)
1219 tasklet_schedule(&chan->tasklet);
1220
1221 return ret;
1222 }
1223
nbpf_err_irq(int irq,void * dev)1224 static 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
nbpf_chan_probe(struct nbpf_device * nbpf,int n)1245 static 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
1277 static 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 };
1289 MODULE_DEVICE_TABLE(of, nbpf_match);
1290
nbpf_probe(struct platform_device * pdev)1291 static 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
1454 e_dma_dev_unreg:
1455 dma_async_device_unregister(dma_dev);
1456 e_clk_off:
1457 clk_disable_unprepare(nbpf->clk);
1458
1459 return ret;
1460 }
1461
nbpf_remove(struct platform_device * pdev)1462 static 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
1484 static 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 };
1496 MODULE_DEVICE_TABLE(platform, nbpf_ids);
1497
1498 #ifdef CONFIG_PM
nbpf_runtime_suspend(struct device * dev)1499 static 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
nbpf_runtime_resume(struct device * dev)1506 static 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
1513 static const struct dev_pm_ops nbpf_pm_ops = {
1514 SET_RUNTIME_PM_OPS(nbpf_runtime_suspend, nbpf_runtime_resume, NULL)
1515 };
1516
1517 static 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
1528 module_platform_driver(nbpf_driver);
1529
1530 MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>");
1531 MODULE_DESCRIPTION("dmaengine driver for NBPFAXI64* DMACs");
1532 MODULE_LICENSE("GPL v2");
1533