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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2018 Exceet Electronics GmbH
4 * Copyright (C) 2018 Bootlin
5 *
6 * Author: Boris Brezillon <boris.brezillon@bootlin.com>
7 */
8#include <linux/dmaengine.h>
9#include <linux/pm_runtime.h>
10#include <linux/spi/spi.h>
11#include <linux/spi/spi-mem.h>
12
13#include "internals.h"
14
15#define SPI_MEM_MAX_BUSWIDTH 8
16
17/**
18 * spi_controller_dma_map_mem_op_data() - DMA-map the buffer attached to a
19 * memory operation
20 * @ctlr: the SPI controller requesting this dma_map()
21 * @op: the memory operation containing the buffer to map
22 * @sgt: a pointer to a non-initialized sg_table that will be filled by this
23 * function
24 *
25 * Some controllers might want to do DMA on the data buffer embedded in @op.
26 * This helper prepares everything for you and provides a ready-to-use
27 * sg_table. This function is not intended to be called from spi drivers.
28 * Only SPI controller drivers should use it.
29 * Note that the caller must ensure the memory region pointed by
30 * op->data.buf.{in,out} is DMA-able before calling this function.
31 *
32 * Return: 0 in case of success, a negative error code otherwise.
33 */
34int spi_controller_dma_map_mem_op_data(struct spi_controller *ctlr,
35 const struct spi_mem_op *op,
36 struct sg_table *sgt)
37{
38 struct device *dmadev;
39
40 if (!op->data.nbytes)
41 return -EINVAL;
42
43 if (op->data.dir == SPI_MEM_DATA_OUT && ctlr->dma_tx)
44 dmadev = ctlr->dma_tx->device->dev;
45 else if (op->data.dir == SPI_MEM_DATA_IN && ctlr->dma_rx)
46 dmadev = ctlr->dma_rx->device->dev;
47 else
48 dmadev = ctlr->dev.parent;
49
50 if (!dmadev)
51 return -EINVAL;
52
53 return spi_map_buf(ctlr, dmadev, sgt, op->data.buf.in, op->data.nbytes,
54 op->data.dir == SPI_MEM_DATA_IN ?
55 DMA_FROM_DEVICE : DMA_TO_DEVICE);
56}
57EXPORT_SYMBOL_GPL(spi_controller_dma_map_mem_op_data);
58
59/**
60 * spi_controller_dma_unmap_mem_op_data() - DMA-unmap the buffer attached to a
61 * memory operation
62 * @ctlr: the SPI controller requesting this dma_unmap()
63 * @op: the memory operation containing the buffer to unmap
64 * @sgt: a pointer to an sg_table previously initialized by
65 * spi_controller_dma_map_mem_op_data()
66 *
67 * Some controllers might want to do DMA on the data buffer embedded in @op.
68 * This helper prepares things so that the CPU can access the
69 * op->data.buf.{in,out} buffer again.
70 *
71 * This function is not intended to be called from SPI drivers. Only SPI
72 * controller drivers should use it.
73 *
74 * This function should be called after the DMA operation has finished and is
75 * only valid if the previous spi_controller_dma_map_mem_op_data() call
76 * returned 0.
77 *
78 * Return: 0 in case of success, a negative error code otherwise.
79 */
80void spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr,
81 const struct spi_mem_op *op,
82 struct sg_table *sgt)
83{
84 struct device *dmadev;
85
86 if (!op->data.nbytes)
87 return;
88
89 if (op->data.dir == SPI_MEM_DATA_OUT && ctlr->dma_tx)
90 dmadev = ctlr->dma_tx->device->dev;
91 else if (op->data.dir == SPI_MEM_DATA_IN && ctlr->dma_rx)
92 dmadev = ctlr->dma_rx->device->dev;
93 else
94 dmadev = ctlr->dev.parent;
95
96 spi_unmap_buf(ctlr, dmadev, sgt,
97 op->data.dir == SPI_MEM_DATA_IN ?
98 DMA_FROM_DEVICE : DMA_TO_DEVICE);
99}
100EXPORT_SYMBOL_GPL(spi_controller_dma_unmap_mem_op_data);
101
102static int spi_check_buswidth_req(struct spi_mem *mem, u8 buswidth, bool tx)
103{
104 u32 mode = mem->spi->mode;
105
106 switch (buswidth) {
107 case 1:
108 return 0;
109
110 case 2:
111 if ((tx &&
112 (mode & (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL))) ||
113 (!tx &&
114 (mode & (SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL))))
115 return 0;
116
117 break;
118
119 case 4:
120 if ((tx && (mode & (SPI_TX_QUAD | SPI_TX_OCTAL))) ||
121 (!tx && (mode & (SPI_RX_QUAD | SPI_RX_OCTAL))))
122 return 0;
123
124 break;
125
126 case 8:
127 if ((tx && (mode & SPI_TX_OCTAL)) ||
128 (!tx && (mode & SPI_RX_OCTAL)))
129 return 0;
130
131 break;
132
133 default:
134 break;
135 }
136
137 return -ENOTSUPP;
138}
139
140bool spi_mem_default_supports_op(struct spi_mem *mem,
141 const struct spi_mem_op *op)
142{
143 if (spi_check_buswidth_req(mem, op->cmd.buswidth, true))
144 return false;
145
146 if (op->addr.nbytes &&
147 spi_check_buswidth_req(mem, op->addr.buswidth, true))
148 return false;
149
150 if (op->dummy.nbytes &&
151 spi_check_buswidth_req(mem, op->dummy.buswidth, true))
152 return false;
153
154 if (op->data.dir != SPI_MEM_NO_DATA &&
155 spi_check_buswidth_req(mem, op->data.buswidth,
156 op->data.dir == SPI_MEM_DATA_OUT))
157 return false;
158
159 if (op->cmd.dtr || op->addr.dtr || op->dummy.dtr || op->data.dtr)
160 return false;
161
162 if (op->cmd.nbytes != 1)
163 return false;
164
165 return true;
166}
167EXPORT_SYMBOL_GPL(spi_mem_default_supports_op);
168
169static bool spi_mem_buswidth_is_valid(u8 buswidth)
170{
171 if (hweight8(buswidth) > 1 || buswidth > SPI_MEM_MAX_BUSWIDTH)
172 return false;
173
174 return true;
175}
176
177static int spi_mem_check_op(const struct spi_mem_op *op)
178{
179 if (!op->cmd.buswidth || !op->cmd.nbytes)
180 return -EINVAL;
181
182 if ((op->addr.nbytes && !op->addr.buswidth) ||
183 (op->dummy.nbytes && !op->dummy.buswidth) ||
184 (op->data.nbytes && !op->data.buswidth))
185 return -EINVAL;
186
187 if (!spi_mem_buswidth_is_valid(op->cmd.buswidth) ||
188 !spi_mem_buswidth_is_valid(op->addr.buswidth) ||
189 !spi_mem_buswidth_is_valid(op->dummy.buswidth) ||
190 !spi_mem_buswidth_is_valid(op->data.buswidth))
191 return -EINVAL;
192
193 return 0;
194}
195
196static bool spi_mem_internal_supports_op(struct spi_mem *mem,
197 const struct spi_mem_op *op)
198{
199 struct spi_controller *ctlr = mem->spi->controller;
200
201 if (ctlr->mem_ops && ctlr->mem_ops->supports_op)
202 return ctlr->mem_ops->supports_op(mem, op);
203
204 return spi_mem_default_supports_op(mem, op);
205}
206
207/**
208 * spi_mem_supports_op() - Check if a memory device and the controller it is
209 * connected to support a specific memory operation
210 * @mem: the SPI memory
211 * @op: the memory operation to check
212 *
213 * Some controllers are only supporting Single or Dual IOs, others might only
214 * support specific opcodes, or it can even be that the controller and device
215 * both support Quad IOs but the hardware prevents you from using it because
216 * only 2 IO lines are connected.
217 *
218 * This function checks whether a specific operation is supported.
219 *
220 * Return: true if @op is supported, false otherwise.
221 */
222bool spi_mem_supports_op(struct spi_mem *mem, const struct spi_mem_op *op)
223{
224 if (spi_mem_check_op(op))
225 return false;
226
227 return spi_mem_internal_supports_op(mem, op);
228}
229EXPORT_SYMBOL_GPL(spi_mem_supports_op);
230
231static int spi_mem_access_start(struct spi_mem *mem)
232{
233 struct spi_controller *ctlr = mem->spi->controller;
234
235 /*
236 * Flush the message queue before executing our SPI memory
237 * operation to prevent preemption of regular SPI transfers.
238 */
239 spi_flush_queue(ctlr);
240
241 if (ctlr->auto_runtime_pm) {
242 int ret;
243
244 ret = pm_runtime_get_sync(ctlr->dev.parent);
245 if (ret < 0) {
246 dev_err(&ctlr->dev, "Failed to power device: %d\n",
247 ret);
248 return ret;
249 }
250 }
251
252 mutex_lock(&ctlr->bus_lock_mutex);
253 mutex_lock(&ctlr->io_mutex);
254
255 return 0;
256}
257
258static void spi_mem_access_end(struct spi_mem *mem)
259{
260 struct spi_controller *ctlr = mem->spi->controller;
261
262 mutex_unlock(&ctlr->io_mutex);
263 mutex_unlock(&ctlr->bus_lock_mutex);
264
265 if (ctlr->auto_runtime_pm)
266 pm_runtime_put(ctlr->dev.parent);
267}
268
269/**
270 * spi_mem_exec_op() - Execute a memory operation
271 * @mem: the SPI memory
272 * @op: the memory operation to execute
273 *
274 * Executes a memory operation.
275 *
276 * This function first checks that @op is supported and then tries to execute
277 * it.
278 *
279 * Return: 0 in case of success, a negative error code otherwise.
280 */
281int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
282{
283 unsigned int tmpbufsize, xferpos = 0, totalxferlen = 0;
284 struct spi_controller *ctlr = mem->spi->controller;
285 struct spi_transfer xfers[4] = { };
286 struct spi_message msg;
287 u8 *tmpbuf;
288 int ret;
289
290 ret = spi_mem_check_op(op);
291 if (ret)
292 return ret;
293
294 if (!spi_mem_internal_supports_op(mem, op))
295 return -ENOTSUPP;
296
297 if (ctlr->mem_ops && !mem->spi->cs_gpiod) {
298 ret = spi_mem_access_start(mem);
299 if (ret)
300 return ret;
301
302 ret = ctlr->mem_ops->exec_op(mem, op);
303
304 spi_mem_access_end(mem);
305
306 /*
307 * Some controllers only optimize specific paths (typically the
308 * read path) and expect the core to use the regular SPI
309 * interface in other cases.
310 */
311 if (!ret || ret != -ENOTSUPP)
312 return ret;
313 }
314
315 tmpbufsize = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes;
316
317 /*
318 * Allocate a buffer to transmit the CMD, ADDR cycles with kmalloc() so
319 * we're guaranteed that this buffer is DMA-able, as required by the
320 * SPI layer.
321 */
322 tmpbuf = kzalloc(tmpbufsize, GFP_KERNEL | GFP_DMA);
323 if (!tmpbuf)
324 return -ENOMEM;
325
326 spi_message_init(&msg);
327
328 tmpbuf[0] = op->cmd.opcode;
329 xfers[xferpos].tx_buf = tmpbuf;
330 xfers[xferpos].len = op->cmd.nbytes;
331 xfers[xferpos].tx_nbits = op->cmd.buswidth;
332 spi_message_add_tail(&xfers[xferpos], &msg);
333 xferpos++;
334 totalxferlen++;
335
336 if (op->addr.nbytes) {
337 int i;
338
339 for (i = 0; i < op->addr.nbytes; i++)
340 tmpbuf[i + 1] = op->addr.val >>
341 (8 * (op->addr.nbytes - i - 1));
342
343 xfers[xferpos].tx_buf = tmpbuf + 1;
344 xfers[xferpos].len = op->addr.nbytes;
345 xfers[xferpos].tx_nbits = op->addr.buswidth;
346 spi_message_add_tail(&xfers[xferpos], &msg);
347 xferpos++;
348 totalxferlen += op->addr.nbytes;
349 }
350
351 if (op->dummy.nbytes) {
352 memset(tmpbuf + op->addr.nbytes + 1, 0xff, op->dummy.nbytes);
353 xfers[xferpos].tx_buf = tmpbuf + op->addr.nbytes + 1;
354 xfers[xferpos].len = op->dummy.nbytes;
355 xfers[xferpos].tx_nbits = op->dummy.buswidth;
356 spi_message_add_tail(&xfers[xferpos], &msg);
357 xferpos++;
358 totalxferlen += op->dummy.nbytes;
359 }
360
361 if (op->data.nbytes) {
362 if (op->data.dir == SPI_MEM_DATA_IN) {
363 xfers[xferpos].rx_buf = op->data.buf.in;
364 xfers[xferpos].rx_nbits = op->data.buswidth;
365 } else {
366 xfers[xferpos].tx_buf = op->data.buf.out;
367 xfers[xferpos].tx_nbits = op->data.buswidth;
368 }
369
370 xfers[xferpos].len = op->data.nbytes;
371 spi_message_add_tail(&xfers[xferpos], &msg);
372 xferpos++;
373 totalxferlen += op->data.nbytes;
374 }
375
376 ret = spi_sync(mem->spi, &msg);
377
378 kfree(tmpbuf);
379
380 if (ret)
381 return ret;
382
383 if (msg.actual_length != totalxferlen)
384 return -EIO;
385
386 return 0;
387}
388EXPORT_SYMBOL_GPL(spi_mem_exec_op);
389
390/**
391 * spi_mem_get_name() - Return the SPI mem device name to be used by the
392 * upper layer if necessary
393 * @mem: the SPI memory
394 *
395 * This function allows SPI mem users to retrieve the SPI mem device name.
396 * It is useful if the upper layer needs to expose a custom name for
397 * compatibility reasons.
398 *
399 * Return: a string containing the name of the memory device to be used
400 * by the SPI mem user
401 */
402const char *spi_mem_get_name(struct spi_mem *mem)
403{
404 return mem->name;
405}
406EXPORT_SYMBOL_GPL(spi_mem_get_name);
407
408/**
409 * spi_mem_adjust_op_size() - Adjust the data size of a SPI mem operation to
410 * match controller limitations
411 * @mem: the SPI memory
412 * @op: the operation to adjust
413 *
414 * Some controllers have FIFO limitations and must split a data transfer
415 * operation into multiple ones, others require a specific alignment for
416 * optimized accesses. This function allows SPI mem drivers to split a single
417 * operation into multiple sub-operations when required.
418 *
419 * Return: a negative error code if the controller can't properly adjust @op,
420 * 0 otherwise. Note that @op->data.nbytes will be updated if @op
421 * can't be handled in a single step.
422 */
423int spi_mem_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
424{
425 struct spi_controller *ctlr = mem->spi->controller;
426 size_t len;
427
428 if (ctlr->mem_ops && ctlr->mem_ops->adjust_op_size)
429 return ctlr->mem_ops->adjust_op_size(mem, op);
430
431 if (!ctlr->mem_ops || !ctlr->mem_ops->exec_op) {
432 len = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes;
433
434 if (len > spi_max_transfer_size(mem->spi))
435 return -EINVAL;
436
437 op->data.nbytes = min3((size_t)op->data.nbytes,
438 spi_max_transfer_size(mem->spi),
439 spi_max_message_size(mem->spi) -
440 len);
441 if (!op->data.nbytes)
442 return -EINVAL;
443 }
444
445 return 0;
446}
447EXPORT_SYMBOL_GPL(spi_mem_adjust_op_size);
448
449static ssize_t spi_mem_no_dirmap_read(struct spi_mem_dirmap_desc *desc,
450 u64 offs, size_t len, void *buf)
451{
452 struct spi_mem_op op = desc->info.op_tmpl;
453 int ret;
454
455 op.addr.val = desc->info.offset + offs;
456 op.data.buf.in = buf;
457 op.data.nbytes = len;
458 ret = spi_mem_adjust_op_size(desc->mem, &op);
459 if (ret)
460 return ret;
461
462 ret = spi_mem_exec_op(desc->mem, &op);
463 if (ret)
464 return ret;
465
466 return op.data.nbytes;
467}
468
469static ssize_t spi_mem_no_dirmap_write(struct spi_mem_dirmap_desc *desc,
470 u64 offs, size_t len, const void *buf)
471{
472 struct spi_mem_op op = desc->info.op_tmpl;
473 int ret;
474
475 op.addr.val = desc->info.offset + offs;
476 op.data.buf.out = buf;
477 op.data.nbytes = len;
478 ret = spi_mem_adjust_op_size(desc->mem, &op);
479 if (ret)
480 return ret;
481
482 ret = spi_mem_exec_op(desc->mem, &op);
483 if (ret)
484 return ret;
485
486 return op.data.nbytes;
487}
488
489/**
490 * spi_mem_dirmap_create() - Create a direct mapping descriptor
491 * @mem: SPI mem device this direct mapping should be created for
492 * @info: direct mapping information
493 *
494 * This function is creating a direct mapping descriptor which can then be used
495 * to access the memory using spi_mem_dirmap_read() or spi_mem_dirmap_write().
496 * If the SPI controller driver does not support direct mapping, this function
497 * falls back to an implementation using spi_mem_exec_op(), so that the caller
498 * doesn't have to bother implementing a fallback on his own.
499 *
500 * Return: a valid pointer in case of success, and ERR_PTR() otherwise.
501 */
502struct spi_mem_dirmap_desc *
503spi_mem_dirmap_create(struct spi_mem *mem,
504 const struct spi_mem_dirmap_info *info)
505{
506 struct spi_controller *ctlr = mem->spi->controller;
507 struct spi_mem_dirmap_desc *desc;
508 int ret = -ENOTSUPP;
509
510 /* Make sure the number of address cycles is between 1 and 8 bytes. */
511 if (!info->op_tmpl.addr.nbytes || info->op_tmpl.addr.nbytes > 8)
512 return ERR_PTR(-EINVAL);
513
514 /* data.dir should either be SPI_MEM_DATA_IN or SPI_MEM_DATA_OUT. */
515 if (info->op_tmpl.data.dir == SPI_MEM_NO_DATA)
516 return ERR_PTR(-EINVAL);
517
518 desc = kzalloc(sizeof(*desc), GFP_KERNEL);
519 if (!desc)
520 return ERR_PTR(-ENOMEM);
521
522 desc->mem = mem;
523 desc->info = *info;
524 if (ctlr->mem_ops && ctlr->mem_ops->dirmap_create)
525 ret = ctlr->mem_ops->dirmap_create(desc);
526
527 if (ret) {
528 desc->nodirmap = true;
529 if (!spi_mem_supports_op(desc->mem, &desc->info.op_tmpl))
530 ret = -ENOTSUPP;
531 else
532 ret = 0;
533 }
534
535 if (ret) {
536 kfree(desc);
537 return ERR_PTR(ret);
538 }
539
540 return desc;
541}
542EXPORT_SYMBOL_GPL(spi_mem_dirmap_create);
543
544/**
545 * spi_mem_dirmap_destroy() - Destroy a direct mapping descriptor
546 * @desc: the direct mapping descriptor to destroy
547 *
548 * This function destroys a direct mapping descriptor previously created by
549 * spi_mem_dirmap_create().
550 */
551void spi_mem_dirmap_destroy(struct spi_mem_dirmap_desc *desc)
552{
553 struct spi_controller *ctlr = desc->mem->spi->controller;
554
555 if (!desc->nodirmap && ctlr->mem_ops && ctlr->mem_ops->dirmap_destroy)
556 ctlr->mem_ops->dirmap_destroy(desc);
557
558 kfree(desc);
559}
560EXPORT_SYMBOL_GPL(spi_mem_dirmap_destroy);
561
562static void devm_spi_mem_dirmap_release(struct device *dev, void *res)
563{
564 struct spi_mem_dirmap_desc *desc = *(struct spi_mem_dirmap_desc **)res;
565
566 spi_mem_dirmap_destroy(desc);
567}
568
569/**
570 * devm_spi_mem_dirmap_create() - Create a direct mapping descriptor and attach
571 * it to a device
572 * @dev: device the dirmap desc will be attached to
573 * @mem: SPI mem device this direct mapping should be created for
574 * @info: direct mapping information
575 *
576 * devm_ variant of the spi_mem_dirmap_create() function. See
577 * spi_mem_dirmap_create() for more details.
578 *
579 * Return: a valid pointer in case of success, and ERR_PTR() otherwise.
580 */
581struct spi_mem_dirmap_desc *
582devm_spi_mem_dirmap_create(struct device *dev, struct spi_mem *mem,
583 const struct spi_mem_dirmap_info *info)
584{
585 struct spi_mem_dirmap_desc **ptr, *desc;
586
587 ptr = devres_alloc(devm_spi_mem_dirmap_release, sizeof(*ptr),
588 GFP_KERNEL);
589 if (!ptr)
590 return ERR_PTR(-ENOMEM);
591
592 desc = spi_mem_dirmap_create(mem, info);
593 if (IS_ERR(desc)) {
594 devres_free(ptr);
595 } else {
596 *ptr = desc;
597 devres_add(dev, ptr);
598 }
599
600 return desc;
601}
602EXPORT_SYMBOL_GPL(devm_spi_mem_dirmap_create);
603
604static int devm_spi_mem_dirmap_match(struct device *dev, void *res, void *data)
605{
606 struct spi_mem_dirmap_desc **ptr = res;
607
608 if (WARN_ON(!ptr || !*ptr))
609 return 0;
610
611 return *ptr == data;
612}
613
614/**
615 * devm_spi_mem_dirmap_destroy() - Destroy a direct mapping descriptor attached
616 * to a device
617 * @dev: device the dirmap desc is attached to
618 * @desc: the direct mapping descriptor to destroy
619 *
620 * devm_ variant of the spi_mem_dirmap_destroy() function. See
621 * spi_mem_dirmap_destroy() for more details.
622 */
623void devm_spi_mem_dirmap_destroy(struct device *dev,
624 struct spi_mem_dirmap_desc *desc)
625{
626 devres_release(dev, devm_spi_mem_dirmap_release,
627 devm_spi_mem_dirmap_match, desc);
628}
629EXPORT_SYMBOL_GPL(devm_spi_mem_dirmap_destroy);
630
631/**
632 * spi_mem_dirmap_read() - Read data through a direct mapping
633 * @desc: direct mapping descriptor
634 * @offs: offset to start reading from. Note that this is not an absolute
635 * offset, but the offset within the direct mapping which already has
636 * its own offset
637 * @len: length in bytes
638 * @buf: destination buffer. This buffer must be DMA-able
639 *
640 * This function reads data from a memory device using a direct mapping
641 * previously instantiated with spi_mem_dirmap_create().
642 *
643 * Return: the amount of data read from the memory device or a negative error
644 * code. Note that the returned size might be smaller than @len, and the caller
645 * is responsible for calling spi_mem_dirmap_read() again when that happens.
646 */
647ssize_t spi_mem_dirmap_read(struct spi_mem_dirmap_desc *desc,
648 u64 offs, size_t len, void *buf)
649{
650 struct spi_controller *ctlr = desc->mem->spi->controller;
651 ssize_t ret;
652
653 if (desc->info.op_tmpl.data.dir != SPI_MEM_DATA_IN)
654 return -EINVAL;
655
656 if (!len)
657 return 0;
658
659 if (desc->nodirmap) {
660 ret = spi_mem_no_dirmap_read(desc, offs, len, buf);
661 } else if (ctlr->mem_ops && ctlr->mem_ops->dirmap_read) {
662 ret = spi_mem_access_start(desc->mem);
663 if (ret)
664 return ret;
665
666 ret = ctlr->mem_ops->dirmap_read(desc, offs, len, buf);
667
668 spi_mem_access_end(desc->mem);
669 } else {
670 ret = -ENOTSUPP;
671 }
672
673 return ret;
674}
675EXPORT_SYMBOL_GPL(spi_mem_dirmap_read);
676
677/**
678 * spi_mem_dirmap_write() - Write data through a direct mapping
679 * @desc: direct mapping descriptor
680 * @offs: offset to start writing from. Note that this is not an absolute
681 * offset, but the offset within the direct mapping which already has
682 * its own offset
683 * @len: length in bytes
684 * @buf: source buffer. This buffer must be DMA-able
685 *
686 * This function writes data to a memory device using a direct mapping
687 * previously instantiated with spi_mem_dirmap_create().
688 *
689 * Return: the amount of data written to the memory device or a negative error
690 * code. Note that the returned size might be smaller than @len, and the caller
691 * is responsible for calling spi_mem_dirmap_write() again when that happens.
692 */
693ssize_t spi_mem_dirmap_write(struct spi_mem_dirmap_desc *desc,
694 u64 offs, size_t len, const void *buf)
695{
696 struct spi_controller *ctlr = desc->mem->spi->controller;
697 ssize_t ret;
698
699 if (desc->info.op_tmpl.data.dir != SPI_MEM_DATA_OUT)
700 return -EINVAL;
701
702 if (!len)
703 return 0;
704
705 if (desc->nodirmap) {
706 ret = spi_mem_no_dirmap_write(desc, offs, len, buf);
707 } else if (ctlr->mem_ops && ctlr->mem_ops->dirmap_write) {
708 ret = spi_mem_access_start(desc->mem);
709 if (ret)
710 return ret;
711
712 ret = ctlr->mem_ops->dirmap_write(desc, offs, len, buf);
713
714 spi_mem_access_end(desc->mem);
715 } else {
716 ret = -ENOTSUPP;
717 }
718
719 return ret;
720}
721EXPORT_SYMBOL_GPL(spi_mem_dirmap_write);
722
723static inline struct spi_mem_driver *to_spi_mem_drv(struct device_driver *drv)
724{
725 return container_of(drv, struct spi_mem_driver, spidrv.driver);
726}
727
728static int spi_mem_probe(struct spi_device *spi)
729{
730 struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
731 struct spi_controller *ctlr = spi->controller;
732 struct spi_mem *mem;
733
734 mem = devm_kzalloc(&spi->dev, sizeof(*mem), GFP_KERNEL);
735 if (!mem)
736 return -ENOMEM;
737
738 mem->spi = spi;
739
740 if (ctlr->mem_ops && ctlr->mem_ops->get_name)
741 mem->name = ctlr->mem_ops->get_name(mem);
742 else
743 mem->name = dev_name(&spi->dev);
744
745 if (IS_ERR_OR_NULL(mem->name))
746 return PTR_ERR(mem->name);
747
748 spi_set_drvdata(spi, mem);
749
750 return memdrv->probe(mem);
751}
752
753static int spi_mem_remove(struct spi_device *spi)
754{
755 struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
756 struct spi_mem *mem = spi_get_drvdata(spi);
757
758 if (memdrv->remove)
759 return memdrv->remove(mem);
760
761 return 0;
762}
763
764static void spi_mem_shutdown(struct spi_device *spi)
765{
766 struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
767 struct spi_mem *mem = spi_get_drvdata(spi);
768
769 if (memdrv->shutdown)
770 memdrv->shutdown(mem);
771}
772
773/**
774 * spi_mem_driver_register_with_owner() - Register a SPI memory driver
775 * @memdrv: the SPI memory driver to register
776 * @owner: the owner of this driver
777 *
778 * Registers a SPI memory driver.
779 *
780 * Return: 0 in case of success, a negative error core otherwise.
781 */
782
783int spi_mem_driver_register_with_owner(struct spi_mem_driver *memdrv,
784 struct module *owner)
785{
786 memdrv->spidrv.probe = spi_mem_probe;
787 memdrv->spidrv.remove = spi_mem_remove;
788 memdrv->spidrv.shutdown = spi_mem_shutdown;
789
790 return __spi_register_driver(owner, &memdrv->spidrv);
791}
792EXPORT_SYMBOL_GPL(spi_mem_driver_register_with_owner);
793
794/**
795 * spi_mem_driver_unregister_with_owner() - Unregister a SPI memory driver
796 * @memdrv: the SPI memory driver to unregister
797 *
798 * Unregisters a SPI memory driver.
799 */
800void spi_mem_driver_unregister(struct spi_mem_driver *memdrv)
801{
802 spi_unregister_driver(&memdrv->spidrv);
803}
804EXPORT_SYMBOL_GPL(spi_mem_driver_unregister);
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2018 Exceet Electronics GmbH
4 * Copyright (C) 2018 Bootlin
5 *
6 * Author: Boris Brezillon <boris.brezillon@bootlin.com>
7 */
8#include <linux/dmaengine.h>
9#include <linux/iopoll.h>
10#include <linux/pm_runtime.h>
11#include <linux/spi/spi.h>
12#include <linux/spi/spi-mem.h>
13#include <linux/sched/task_stack.h>
14
15#include "internals.h"
16
17#define SPI_MEM_MAX_BUSWIDTH 8
18
19/**
20 * spi_controller_dma_map_mem_op_data() - DMA-map the buffer attached to a
21 * memory operation
22 * @ctlr: the SPI controller requesting this dma_map()
23 * @op: the memory operation containing the buffer to map
24 * @sgt: a pointer to a non-initialized sg_table that will be filled by this
25 * function
26 *
27 * Some controllers might want to do DMA on the data buffer embedded in @op.
28 * This helper prepares everything for you and provides a ready-to-use
29 * sg_table. This function is not intended to be called from spi drivers.
30 * Only SPI controller drivers should use it.
31 * Note that the caller must ensure the memory region pointed by
32 * op->data.buf.{in,out} is DMA-able before calling this function.
33 *
34 * Return: 0 in case of success, a negative error code otherwise.
35 */
36int spi_controller_dma_map_mem_op_data(struct spi_controller *ctlr,
37 const struct spi_mem_op *op,
38 struct sg_table *sgt)
39{
40 struct device *dmadev;
41
42 if (!op->data.nbytes)
43 return -EINVAL;
44
45 if (op->data.dir == SPI_MEM_DATA_OUT && ctlr->dma_tx)
46 dmadev = ctlr->dma_tx->device->dev;
47 else if (op->data.dir == SPI_MEM_DATA_IN && ctlr->dma_rx)
48 dmadev = ctlr->dma_rx->device->dev;
49 else
50 dmadev = ctlr->dev.parent;
51
52 if (!dmadev)
53 return -EINVAL;
54
55 return spi_map_buf(ctlr, dmadev, sgt, op->data.buf.in, op->data.nbytes,
56 op->data.dir == SPI_MEM_DATA_IN ?
57 DMA_FROM_DEVICE : DMA_TO_DEVICE);
58}
59EXPORT_SYMBOL_GPL(spi_controller_dma_map_mem_op_data);
60
61/**
62 * spi_controller_dma_unmap_mem_op_data() - DMA-unmap the buffer attached to a
63 * memory operation
64 * @ctlr: the SPI controller requesting this dma_unmap()
65 * @op: the memory operation containing the buffer to unmap
66 * @sgt: a pointer to an sg_table previously initialized by
67 * spi_controller_dma_map_mem_op_data()
68 *
69 * Some controllers might want to do DMA on the data buffer embedded in @op.
70 * This helper prepares things so that the CPU can access the
71 * op->data.buf.{in,out} buffer again.
72 *
73 * This function is not intended to be called from SPI drivers. Only SPI
74 * controller drivers should use it.
75 *
76 * This function should be called after the DMA operation has finished and is
77 * only valid if the previous spi_controller_dma_map_mem_op_data() call
78 * returned 0.
79 *
80 * Return: 0 in case of success, a negative error code otherwise.
81 */
82void spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr,
83 const struct spi_mem_op *op,
84 struct sg_table *sgt)
85{
86 struct device *dmadev;
87
88 if (!op->data.nbytes)
89 return;
90
91 if (op->data.dir == SPI_MEM_DATA_OUT && ctlr->dma_tx)
92 dmadev = ctlr->dma_tx->device->dev;
93 else if (op->data.dir == SPI_MEM_DATA_IN && ctlr->dma_rx)
94 dmadev = ctlr->dma_rx->device->dev;
95 else
96 dmadev = ctlr->dev.parent;
97
98 spi_unmap_buf(ctlr, dmadev, sgt,
99 op->data.dir == SPI_MEM_DATA_IN ?
100 DMA_FROM_DEVICE : DMA_TO_DEVICE);
101}
102EXPORT_SYMBOL_GPL(spi_controller_dma_unmap_mem_op_data);
103
104static int spi_check_buswidth_req(struct spi_mem *mem, u8 buswidth, bool tx)
105{
106 u32 mode = mem->spi->mode;
107
108 switch (buswidth) {
109 case 1:
110 return 0;
111
112 case 2:
113 if ((tx &&
114 (mode & (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL))) ||
115 (!tx &&
116 (mode & (SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL))))
117 return 0;
118
119 break;
120
121 case 4:
122 if ((tx && (mode & (SPI_TX_QUAD | SPI_TX_OCTAL))) ||
123 (!tx && (mode & (SPI_RX_QUAD | SPI_RX_OCTAL))))
124 return 0;
125
126 break;
127
128 case 8:
129 if ((tx && (mode & SPI_TX_OCTAL)) ||
130 (!tx && (mode & SPI_RX_OCTAL)))
131 return 0;
132
133 break;
134
135 default:
136 break;
137 }
138
139 return -ENOTSUPP;
140}
141
142static bool spi_mem_check_buswidth(struct spi_mem *mem,
143 const struct spi_mem_op *op)
144{
145 if (spi_check_buswidth_req(mem, op->cmd.buswidth, true))
146 return false;
147
148 if (op->addr.nbytes &&
149 spi_check_buswidth_req(mem, op->addr.buswidth, true))
150 return false;
151
152 if (op->dummy.nbytes &&
153 spi_check_buswidth_req(mem, op->dummy.buswidth, true))
154 return false;
155
156 if (op->data.dir != SPI_MEM_NO_DATA &&
157 spi_check_buswidth_req(mem, op->data.buswidth,
158 op->data.dir == SPI_MEM_DATA_OUT))
159 return false;
160
161 return true;
162}
163
164bool spi_mem_default_supports_op(struct spi_mem *mem,
165 const struct spi_mem_op *op)
166{
167 struct spi_controller *ctlr = mem->spi->controller;
168 bool op_is_dtr =
169 op->cmd.dtr || op->addr.dtr || op->dummy.dtr || op->data.dtr;
170
171 if (op_is_dtr) {
172 if (!spi_mem_controller_is_capable(ctlr, dtr))
173 return false;
174
175 if (op->cmd.nbytes != 2)
176 return false;
177 } else {
178 if (op->cmd.nbytes != 1)
179 return false;
180 }
181
182 if (op->data.ecc) {
183 if (!spi_mem_controller_is_capable(ctlr, ecc))
184 return false;
185 }
186
187 return spi_mem_check_buswidth(mem, op);
188}
189EXPORT_SYMBOL_GPL(spi_mem_default_supports_op);
190
191static bool spi_mem_buswidth_is_valid(u8 buswidth)
192{
193 if (hweight8(buswidth) > 1 || buswidth > SPI_MEM_MAX_BUSWIDTH)
194 return false;
195
196 return true;
197}
198
199static int spi_mem_check_op(const struct spi_mem_op *op)
200{
201 if (!op->cmd.buswidth || !op->cmd.nbytes)
202 return -EINVAL;
203
204 if ((op->addr.nbytes && !op->addr.buswidth) ||
205 (op->dummy.nbytes && !op->dummy.buswidth) ||
206 (op->data.nbytes && !op->data.buswidth))
207 return -EINVAL;
208
209 if (!spi_mem_buswidth_is_valid(op->cmd.buswidth) ||
210 !spi_mem_buswidth_is_valid(op->addr.buswidth) ||
211 !spi_mem_buswidth_is_valid(op->dummy.buswidth) ||
212 !spi_mem_buswidth_is_valid(op->data.buswidth))
213 return -EINVAL;
214
215 /* Buffers must be DMA-able. */
216 if (WARN_ON_ONCE(op->data.dir == SPI_MEM_DATA_IN &&
217 object_is_on_stack(op->data.buf.in)))
218 return -EINVAL;
219
220 if (WARN_ON_ONCE(op->data.dir == SPI_MEM_DATA_OUT &&
221 object_is_on_stack(op->data.buf.out)))
222 return -EINVAL;
223
224 return 0;
225}
226
227static bool spi_mem_internal_supports_op(struct spi_mem *mem,
228 const struct spi_mem_op *op)
229{
230 struct spi_controller *ctlr = mem->spi->controller;
231
232 if (ctlr->mem_ops && ctlr->mem_ops->supports_op)
233 return ctlr->mem_ops->supports_op(mem, op);
234
235 return spi_mem_default_supports_op(mem, op);
236}
237
238/**
239 * spi_mem_supports_op() - Check if a memory device and the controller it is
240 * connected to support a specific memory operation
241 * @mem: the SPI memory
242 * @op: the memory operation to check
243 *
244 * Some controllers are only supporting Single or Dual IOs, others might only
245 * support specific opcodes, or it can even be that the controller and device
246 * both support Quad IOs but the hardware prevents you from using it because
247 * only 2 IO lines are connected.
248 *
249 * This function checks whether a specific operation is supported.
250 *
251 * Return: true if @op is supported, false otherwise.
252 */
253bool spi_mem_supports_op(struct spi_mem *mem, const struct spi_mem_op *op)
254{
255 if (spi_mem_check_op(op))
256 return false;
257
258 return spi_mem_internal_supports_op(mem, op);
259}
260EXPORT_SYMBOL_GPL(spi_mem_supports_op);
261
262static int spi_mem_access_start(struct spi_mem *mem)
263{
264 struct spi_controller *ctlr = mem->spi->controller;
265
266 /*
267 * Flush the message queue before executing our SPI memory
268 * operation to prevent preemption of regular SPI transfers.
269 */
270 spi_flush_queue(ctlr);
271
272 if (ctlr->auto_runtime_pm) {
273 int ret;
274
275 ret = pm_runtime_resume_and_get(ctlr->dev.parent);
276 if (ret < 0) {
277 dev_err(&ctlr->dev, "Failed to power device: %d\n",
278 ret);
279 return ret;
280 }
281 }
282
283 mutex_lock(&ctlr->bus_lock_mutex);
284 mutex_lock(&ctlr->io_mutex);
285
286 return 0;
287}
288
289static void spi_mem_access_end(struct spi_mem *mem)
290{
291 struct spi_controller *ctlr = mem->spi->controller;
292
293 mutex_unlock(&ctlr->io_mutex);
294 mutex_unlock(&ctlr->bus_lock_mutex);
295
296 if (ctlr->auto_runtime_pm)
297 pm_runtime_put(ctlr->dev.parent);
298}
299
300static void spi_mem_add_op_stats(struct spi_statistics __percpu *pcpu_stats,
301 const struct spi_mem_op *op, int exec_op_ret)
302{
303 struct spi_statistics *stats;
304 u64 len, l2len;
305
306 get_cpu();
307 stats = this_cpu_ptr(pcpu_stats);
308 u64_stats_update_begin(&stats->syncp);
309
310 /*
311 * We do not have the concept of messages or transfers. Let's consider
312 * that one operation is equivalent to one message and one transfer.
313 */
314 u64_stats_inc(&stats->messages);
315 u64_stats_inc(&stats->transfers);
316
317 /* Use the sum of all lengths as bytes count and histogram value. */
318 len = op->cmd.nbytes + op->addr.nbytes;
319 len += op->dummy.nbytes + op->data.nbytes;
320 u64_stats_add(&stats->bytes, len);
321 l2len = min(fls(len), SPI_STATISTICS_HISTO_SIZE) - 1;
322 u64_stats_inc(&stats->transfer_bytes_histo[l2len]);
323
324 /* Only account for data bytes as transferred bytes. */
325 if (op->data.nbytes && op->data.dir == SPI_MEM_DATA_OUT)
326 u64_stats_add(&stats->bytes_tx, op->data.nbytes);
327 if (op->data.nbytes && op->data.dir == SPI_MEM_DATA_IN)
328 u64_stats_add(&stats->bytes_rx, op->data.nbytes);
329
330 /*
331 * A timeout is not an error, following the same behavior as
332 * spi_transfer_one_message().
333 */
334 if (exec_op_ret == -ETIMEDOUT)
335 u64_stats_inc(&stats->timedout);
336 else if (exec_op_ret)
337 u64_stats_inc(&stats->errors);
338
339 u64_stats_update_end(&stats->syncp);
340 put_cpu();
341}
342
343/**
344 * spi_mem_exec_op() - Execute a memory operation
345 * @mem: the SPI memory
346 * @op: the memory operation to execute
347 *
348 * Executes a memory operation.
349 *
350 * This function first checks that @op is supported and then tries to execute
351 * it.
352 *
353 * Return: 0 in case of success, a negative error code otherwise.
354 */
355int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
356{
357 unsigned int tmpbufsize, xferpos = 0, totalxferlen = 0;
358 struct spi_controller *ctlr = mem->spi->controller;
359 struct spi_transfer xfers[4] = { };
360 struct spi_message msg;
361 u8 *tmpbuf;
362 int ret;
363
364 ret = spi_mem_check_op(op);
365 if (ret)
366 return ret;
367
368 if (!spi_mem_internal_supports_op(mem, op))
369 return -EOPNOTSUPP;
370
371 if (ctlr->mem_ops && ctlr->mem_ops->exec_op && !spi_get_csgpiod(mem->spi, 0)) {
372 ret = spi_mem_access_start(mem);
373 if (ret)
374 return ret;
375
376 ret = ctlr->mem_ops->exec_op(mem, op);
377
378 spi_mem_access_end(mem);
379
380 /*
381 * Some controllers only optimize specific paths (typically the
382 * read path) and expect the core to use the regular SPI
383 * interface in other cases.
384 */
385 if (!ret || (ret != -ENOTSUPP && ret != -EOPNOTSUPP)) {
386 spi_mem_add_op_stats(ctlr->pcpu_statistics, op, ret);
387 spi_mem_add_op_stats(mem->spi->pcpu_statistics, op, ret);
388
389 return ret;
390 }
391 }
392
393 tmpbufsize = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes;
394
395 /*
396 * Allocate a buffer to transmit the CMD, ADDR cycles with kmalloc() so
397 * we're guaranteed that this buffer is DMA-able, as required by the
398 * SPI layer.
399 */
400 tmpbuf = kzalloc(tmpbufsize, GFP_KERNEL | GFP_DMA);
401 if (!tmpbuf)
402 return -ENOMEM;
403
404 spi_message_init(&msg);
405
406 tmpbuf[0] = op->cmd.opcode;
407 xfers[xferpos].tx_buf = tmpbuf;
408 xfers[xferpos].len = op->cmd.nbytes;
409 xfers[xferpos].tx_nbits = op->cmd.buswidth;
410 spi_message_add_tail(&xfers[xferpos], &msg);
411 xferpos++;
412 totalxferlen++;
413
414 if (op->addr.nbytes) {
415 int i;
416
417 for (i = 0; i < op->addr.nbytes; i++)
418 tmpbuf[i + 1] = op->addr.val >>
419 (8 * (op->addr.nbytes - i - 1));
420
421 xfers[xferpos].tx_buf = tmpbuf + 1;
422 xfers[xferpos].len = op->addr.nbytes;
423 xfers[xferpos].tx_nbits = op->addr.buswidth;
424 spi_message_add_tail(&xfers[xferpos], &msg);
425 xferpos++;
426 totalxferlen += op->addr.nbytes;
427 }
428
429 if (op->dummy.nbytes) {
430 memset(tmpbuf + op->addr.nbytes + 1, 0xff, op->dummy.nbytes);
431 xfers[xferpos].tx_buf = tmpbuf + op->addr.nbytes + 1;
432 xfers[xferpos].len = op->dummy.nbytes;
433 xfers[xferpos].tx_nbits = op->dummy.buswidth;
434 xfers[xferpos].dummy_data = 1;
435 spi_message_add_tail(&xfers[xferpos], &msg);
436 xferpos++;
437 totalxferlen += op->dummy.nbytes;
438 }
439
440 if (op->data.nbytes) {
441 if (op->data.dir == SPI_MEM_DATA_IN) {
442 xfers[xferpos].rx_buf = op->data.buf.in;
443 xfers[xferpos].rx_nbits = op->data.buswidth;
444 } else {
445 xfers[xferpos].tx_buf = op->data.buf.out;
446 xfers[xferpos].tx_nbits = op->data.buswidth;
447 }
448
449 xfers[xferpos].len = op->data.nbytes;
450 spi_message_add_tail(&xfers[xferpos], &msg);
451 xferpos++;
452 totalxferlen += op->data.nbytes;
453 }
454
455 ret = spi_sync(mem->spi, &msg);
456
457 kfree(tmpbuf);
458
459 if (ret)
460 return ret;
461
462 if (msg.actual_length != totalxferlen)
463 return -EIO;
464
465 return 0;
466}
467EXPORT_SYMBOL_GPL(spi_mem_exec_op);
468
469/**
470 * spi_mem_get_name() - Return the SPI mem device name to be used by the
471 * upper layer if necessary
472 * @mem: the SPI memory
473 *
474 * This function allows SPI mem users to retrieve the SPI mem device name.
475 * It is useful if the upper layer needs to expose a custom name for
476 * compatibility reasons.
477 *
478 * Return: a string containing the name of the memory device to be used
479 * by the SPI mem user
480 */
481const char *spi_mem_get_name(struct spi_mem *mem)
482{
483 return mem->name;
484}
485EXPORT_SYMBOL_GPL(spi_mem_get_name);
486
487/**
488 * spi_mem_adjust_op_size() - Adjust the data size of a SPI mem operation to
489 * match controller limitations
490 * @mem: the SPI memory
491 * @op: the operation to adjust
492 *
493 * Some controllers have FIFO limitations and must split a data transfer
494 * operation into multiple ones, others require a specific alignment for
495 * optimized accesses. This function allows SPI mem drivers to split a single
496 * operation into multiple sub-operations when required.
497 *
498 * Return: a negative error code if the controller can't properly adjust @op,
499 * 0 otherwise. Note that @op->data.nbytes will be updated if @op
500 * can't be handled in a single step.
501 */
502int spi_mem_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
503{
504 struct spi_controller *ctlr = mem->spi->controller;
505 size_t len;
506
507 if (ctlr->mem_ops && ctlr->mem_ops->adjust_op_size)
508 return ctlr->mem_ops->adjust_op_size(mem, op);
509
510 if (!ctlr->mem_ops || !ctlr->mem_ops->exec_op) {
511 len = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes;
512
513 if (len > spi_max_transfer_size(mem->spi))
514 return -EINVAL;
515
516 op->data.nbytes = min3((size_t)op->data.nbytes,
517 spi_max_transfer_size(mem->spi),
518 spi_max_message_size(mem->spi) -
519 len);
520 if (!op->data.nbytes)
521 return -EINVAL;
522 }
523
524 return 0;
525}
526EXPORT_SYMBOL_GPL(spi_mem_adjust_op_size);
527
528static ssize_t spi_mem_no_dirmap_read(struct spi_mem_dirmap_desc *desc,
529 u64 offs, size_t len, void *buf)
530{
531 struct spi_mem_op op = desc->info.op_tmpl;
532 int ret;
533
534 op.addr.val = desc->info.offset + offs;
535 op.data.buf.in = buf;
536 op.data.nbytes = len;
537 ret = spi_mem_adjust_op_size(desc->mem, &op);
538 if (ret)
539 return ret;
540
541 ret = spi_mem_exec_op(desc->mem, &op);
542 if (ret)
543 return ret;
544
545 return op.data.nbytes;
546}
547
548static ssize_t spi_mem_no_dirmap_write(struct spi_mem_dirmap_desc *desc,
549 u64 offs, size_t len, const void *buf)
550{
551 struct spi_mem_op op = desc->info.op_tmpl;
552 int ret;
553
554 op.addr.val = desc->info.offset + offs;
555 op.data.buf.out = buf;
556 op.data.nbytes = len;
557 ret = spi_mem_adjust_op_size(desc->mem, &op);
558 if (ret)
559 return ret;
560
561 ret = spi_mem_exec_op(desc->mem, &op);
562 if (ret)
563 return ret;
564
565 return op.data.nbytes;
566}
567
568/**
569 * spi_mem_dirmap_create() - Create a direct mapping descriptor
570 * @mem: SPI mem device this direct mapping should be created for
571 * @info: direct mapping information
572 *
573 * This function is creating a direct mapping descriptor which can then be used
574 * to access the memory using spi_mem_dirmap_read() or spi_mem_dirmap_write().
575 * If the SPI controller driver does not support direct mapping, this function
576 * falls back to an implementation using spi_mem_exec_op(), so that the caller
577 * doesn't have to bother implementing a fallback on his own.
578 *
579 * Return: a valid pointer in case of success, and ERR_PTR() otherwise.
580 */
581struct spi_mem_dirmap_desc *
582spi_mem_dirmap_create(struct spi_mem *mem,
583 const struct spi_mem_dirmap_info *info)
584{
585 struct spi_controller *ctlr = mem->spi->controller;
586 struct spi_mem_dirmap_desc *desc;
587 int ret = -ENOTSUPP;
588
589 /* Make sure the number of address cycles is between 1 and 8 bytes. */
590 if (!info->op_tmpl.addr.nbytes || info->op_tmpl.addr.nbytes > 8)
591 return ERR_PTR(-EINVAL);
592
593 /* data.dir should either be SPI_MEM_DATA_IN or SPI_MEM_DATA_OUT. */
594 if (info->op_tmpl.data.dir == SPI_MEM_NO_DATA)
595 return ERR_PTR(-EINVAL);
596
597 desc = kzalloc(sizeof(*desc), GFP_KERNEL);
598 if (!desc)
599 return ERR_PTR(-ENOMEM);
600
601 desc->mem = mem;
602 desc->info = *info;
603 if (ctlr->mem_ops && ctlr->mem_ops->dirmap_create)
604 ret = ctlr->mem_ops->dirmap_create(desc);
605
606 if (ret) {
607 desc->nodirmap = true;
608 if (!spi_mem_supports_op(desc->mem, &desc->info.op_tmpl))
609 ret = -EOPNOTSUPP;
610 else
611 ret = 0;
612 }
613
614 if (ret) {
615 kfree(desc);
616 return ERR_PTR(ret);
617 }
618
619 return desc;
620}
621EXPORT_SYMBOL_GPL(spi_mem_dirmap_create);
622
623/**
624 * spi_mem_dirmap_destroy() - Destroy a direct mapping descriptor
625 * @desc: the direct mapping descriptor to destroy
626 *
627 * This function destroys a direct mapping descriptor previously created by
628 * spi_mem_dirmap_create().
629 */
630void spi_mem_dirmap_destroy(struct spi_mem_dirmap_desc *desc)
631{
632 struct spi_controller *ctlr = desc->mem->spi->controller;
633
634 if (!desc->nodirmap && ctlr->mem_ops && ctlr->mem_ops->dirmap_destroy)
635 ctlr->mem_ops->dirmap_destroy(desc);
636
637 kfree(desc);
638}
639EXPORT_SYMBOL_GPL(spi_mem_dirmap_destroy);
640
641static void devm_spi_mem_dirmap_release(struct device *dev, void *res)
642{
643 struct spi_mem_dirmap_desc *desc = *(struct spi_mem_dirmap_desc **)res;
644
645 spi_mem_dirmap_destroy(desc);
646}
647
648/**
649 * devm_spi_mem_dirmap_create() - Create a direct mapping descriptor and attach
650 * it to a device
651 * @dev: device the dirmap desc will be attached to
652 * @mem: SPI mem device this direct mapping should be created for
653 * @info: direct mapping information
654 *
655 * devm_ variant of the spi_mem_dirmap_create() function. See
656 * spi_mem_dirmap_create() for more details.
657 *
658 * Return: a valid pointer in case of success, and ERR_PTR() otherwise.
659 */
660struct spi_mem_dirmap_desc *
661devm_spi_mem_dirmap_create(struct device *dev, struct spi_mem *mem,
662 const struct spi_mem_dirmap_info *info)
663{
664 struct spi_mem_dirmap_desc **ptr, *desc;
665
666 ptr = devres_alloc(devm_spi_mem_dirmap_release, sizeof(*ptr),
667 GFP_KERNEL);
668 if (!ptr)
669 return ERR_PTR(-ENOMEM);
670
671 desc = spi_mem_dirmap_create(mem, info);
672 if (IS_ERR(desc)) {
673 devres_free(ptr);
674 } else {
675 *ptr = desc;
676 devres_add(dev, ptr);
677 }
678
679 return desc;
680}
681EXPORT_SYMBOL_GPL(devm_spi_mem_dirmap_create);
682
683static int devm_spi_mem_dirmap_match(struct device *dev, void *res, void *data)
684{
685 struct spi_mem_dirmap_desc **ptr = res;
686
687 if (WARN_ON(!ptr || !*ptr))
688 return 0;
689
690 return *ptr == data;
691}
692
693/**
694 * devm_spi_mem_dirmap_destroy() - Destroy a direct mapping descriptor attached
695 * to a device
696 * @dev: device the dirmap desc is attached to
697 * @desc: the direct mapping descriptor to destroy
698 *
699 * devm_ variant of the spi_mem_dirmap_destroy() function. See
700 * spi_mem_dirmap_destroy() for more details.
701 */
702void devm_spi_mem_dirmap_destroy(struct device *dev,
703 struct spi_mem_dirmap_desc *desc)
704{
705 devres_release(dev, devm_spi_mem_dirmap_release,
706 devm_spi_mem_dirmap_match, desc);
707}
708EXPORT_SYMBOL_GPL(devm_spi_mem_dirmap_destroy);
709
710/**
711 * spi_mem_dirmap_read() - Read data through a direct mapping
712 * @desc: direct mapping descriptor
713 * @offs: offset to start reading from. Note that this is not an absolute
714 * offset, but the offset within the direct mapping which already has
715 * its own offset
716 * @len: length in bytes
717 * @buf: destination buffer. This buffer must be DMA-able
718 *
719 * This function reads data from a memory device using a direct mapping
720 * previously instantiated with spi_mem_dirmap_create().
721 *
722 * Return: the amount of data read from the memory device or a negative error
723 * code. Note that the returned size might be smaller than @len, and the caller
724 * is responsible for calling spi_mem_dirmap_read() again when that happens.
725 */
726ssize_t spi_mem_dirmap_read(struct spi_mem_dirmap_desc *desc,
727 u64 offs, size_t len, void *buf)
728{
729 struct spi_controller *ctlr = desc->mem->spi->controller;
730 ssize_t ret;
731
732 if (desc->info.op_tmpl.data.dir != SPI_MEM_DATA_IN)
733 return -EINVAL;
734
735 if (!len)
736 return 0;
737
738 if (desc->nodirmap) {
739 ret = spi_mem_no_dirmap_read(desc, offs, len, buf);
740 } else if (ctlr->mem_ops && ctlr->mem_ops->dirmap_read) {
741 ret = spi_mem_access_start(desc->mem);
742 if (ret)
743 return ret;
744
745 ret = ctlr->mem_ops->dirmap_read(desc, offs, len, buf);
746
747 spi_mem_access_end(desc->mem);
748 } else {
749 ret = -ENOTSUPP;
750 }
751
752 return ret;
753}
754EXPORT_SYMBOL_GPL(spi_mem_dirmap_read);
755
756/**
757 * spi_mem_dirmap_write() - Write data through a direct mapping
758 * @desc: direct mapping descriptor
759 * @offs: offset to start writing from. Note that this is not an absolute
760 * offset, but the offset within the direct mapping which already has
761 * its own offset
762 * @len: length in bytes
763 * @buf: source buffer. This buffer must be DMA-able
764 *
765 * This function writes data to a memory device using a direct mapping
766 * previously instantiated with spi_mem_dirmap_create().
767 *
768 * Return: the amount of data written to the memory device or a negative error
769 * code. Note that the returned size might be smaller than @len, and the caller
770 * is responsible for calling spi_mem_dirmap_write() again when that happens.
771 */
772ssize_t spi_mem_dirmap_write(struct spi_mem_dirmap_desc *desc,
773 u64 offs, size_t len, const void *buf)
774{
775 struct spi_controller *ctlr = desc->mem->spi->controller;
776 ssize_t ret;
777
778 if (desc->info.op_tmpl.data.dir != SPI_MEM_DATA_OUT)
779 return -EINVAL;
780
781 if (!len)
782 return 0;
783
784 if (desc->nodirmap) {
785 ret = spi_mem_no_dirmap_write(desc, offs, len, buf);
786 } else if (ctlr->mem_ops && ctlr->mem_ops->dirmap_write) {
787 ret = spi_mem_access_start(desc->mem);
788 if (ret)
789 return ret;
790
791 ret = ctlr->mem_ops->dirmap_write(desc, offs, len, buf);
792
793 spi_mem_access_end(desc->mem);
794 } else {
795 ret = -ENOTSUPP;
796 }
797
798 return ret;
799}
800EXPORT_SYMBOL_GPL(spi_mem_dirmap_write);
801
802static inline struct spi_mem_driver *to_spi_mem_drv(struct device_driver *drv)
803{
804 return container_of(drv, struct spi_mem_driver, spidrv.driver);
805}
806
807static int spi_mem_read_status(struct spi_mem *mem,
808 const struct spi_mem_op *op,
809 u16 *status)
810{
811 const u8 *bytes = (u8 *)op->data.buf.in;
812 int ret;
813
814 ret = spi_mem_exec_op(mem, op);
815 if (ret)
816 return ret;
817
818 if (op->data.nbytes > 1)
819 *status = ((u16)bytes[0] << 8) | bytes[1];
820 else
821 *status = bytes[0];
822
823 return 0;
824}
825
826/**
827 * spi_mem_poll_status() - Poll memory device status
828 * @mem: SPI memory device
829 * @op: the memory operation to execute
830 * @mask: status bitmask to ckeck
831 * @match: (status & mask) expected value
832 * @initial_delay_us: delay in us before starting to poll
833 * @polling_delay_us: time to sleep between reads in us
834 * @timeout_ms: timeout in milliseconds
835 *
836 * This function polls a status register and returns when
837 * (status & mask) == match or when the timeout has expired.
838 *
839 * Return: 0 in case of success, -ETIMEDOUT in case of error,
840 * -EOPNOTSUPP if not supported.
841 */
842int spi_mem_poll_status(struct spi_mem *mem,
843 const struct spi_mem_op *op,
844 u16 mask, u16 match,
845 unsigned long initial_delay_us,
846 unsigned long polling_delay_us,
847 u16 timeout_ms)
848{
849 struct spi_controller *ctlr = mem->spi->controller;
850 int ret = -EOPNOTSUPP;
851 int read_status_ret;
852 u16 status;
853
854 if (op->data.nbytes < 1 || op->data.nbytes > 2 ||
855 op->data.dir != SPI_MEM_DATA_IN)
856 return -EINVAL;
857
858 if (ctlr->mem_ops && ctlr->mem_ops->poll_status && !spi_get_csgpiod(mem->spi, 0)) {
859 ret = spi_mem_access_start(mem);
860 if (ret)
861 return ret;
862
863 ret = ctlr->mem_ops->poll_status(mem, op, mask, match,
864 initial_delay_us, polling_delay_us,
865 timeout_ms);
866
867 spi_mem_access_end(mem);
868 }
869
870 if (ret == -EOPNOTSUPP) {
871 if (!spi_mem_supports_op(mem, op))
872 return ret;
873
874 if (initial_delay_us < 10)
875 udelay(initial_delay_us);
876 else
877 usleep_range((initial_delay_us >> 2) + 1,
878 initial_delay_us);
879
880 ret = read_poll_timeout(spi_mem_read_status, read_status_ret,
881 (read_status_ret || ((status) & mask) == match),
882 polling_delay_us, timeout_ms * 1000, false, mem,
883 op, &status);
884 if (read_status_ret)
885 return read_status_ret;
886 }
887
888 return ret;
889}
890EXPORT_SYMBOL_GPL(spi_mem_poll_status);
891
892static int spi_mem_probe(struct spi_device *spi)
893{
894 struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
895 struct spi_controller *ctlr = spi->controller;
896 struct spi_mem *mem;
897
898 mem = devm_kzalloc(&spi->dev, sizeof(*mem), GFP_KERNEL);
899 if (!mem)
900 return -ENOMEM;
901
902 mem->spi = spi;
903
904 if (ctlr->mem_ops && ctlr->mem_ops->get_name)
905 mem->name = ctlr->mem_ops->get_name(mem);
906 else
907 mem->name = dev_name(&spi->dev);
908
909 if (IS_ERR_OR_NULL(mem->name))
910 return PTR_ERR_OR_ZERO(mem->name);
911
912 spi_set_drvdata(spi, mem);
913
914 return memdrv->probe(mem);
915}
916
917static void spi_mem_remove(struct spi_device *spi)
918{
919 struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
920 struct spi_mem *mem = spi_get_drvdata(spi);
921
922 if (memdrv->remove)
923 memdrv->remove(mem);
924}
925
926static void spi_mem_shutdown(struct spi_device *spi)
927{
928 struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
929 struct spi_mem *mem = spi_get_drvdata(spi);
930
931 if (memdrv->shutdown)
932 memdrv->shutdown(mem);
933}
934
935/**
936 * spi_mem_driver_register_with_owner() - Register a SPI memory driver
937 * @memdrv: the SPI memory driver to register
938 * @owner: the owner of this driver
939 *
940 * Registers a SPI memory driver.
941 *
942 * Return: 0 in case of success, a negative error core otherwise.
943 */
944
945int spi_mem_driver_register_with_owner(struct spi_mem_driver *memdrv,
946 struct module *owner)
947{
948 memdrv->spidrv.probe = spi_mem_probe;
949 memdrv->spidrv.remove = spi_mem_remove;
950 memdrv->spidrv.shutdown = spi_mem_shutdown;
951
952 return __spi_register_driver(owner, &memdrv->spidrv);
953}
954EXPORT_SYMBOL_GPL(spi_mem_driver_register_with_owner);
955
956/**
957 * spi_mem_driver_unregister() - Unregister a SPI memory driver
958 * @memdrv: the SPI memory driver to unregister
959 *
960 * Unregisters a SPI memory driver.
961 */
962void spi_mem_driver_unregister(struct spi_mem_driver *memdrv)
963{
964 spi_unregister_driver(&memdrv->spidrv);
965}
966EXPORT_SYMBOL_GPL(spi_mem_driver_unregister);