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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
300/**
301 * spi_mem_exec_op() - Execute a memory operation
302 * @mem: the SPI memory
303 * @op: the memory operation to execute
304 *
305 * Executes a memory operation.
306 *
307 * This function first checks that @op is supported and then tries to execute
308 * it.
309 *
310 * Return: 0 in case of success, a negative error code otherwise.
311 */
312int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
313{
314 unsigned int tmpbufsize, xferpos = 0, totalxferlen = 0;
315 struct spi_controller *ctlr = mem->spi->controller;
316 struct spi_transfer xfers[4] = { };
317 struct spi_message msg;
318 u8 *tmpbuf;
319 int ret;
320
321 ret = spi_mem_check_op(op);
322 if (ret)
323 return ret;
324
325 if (!spi_mem_internal_supports_op(mem, op))
326 return -EOPNOTSUPP;
327
328 if (ctlr->mem_ops && ctlr->mem_ops->exec_op && !spi_get_csgpiod(mem->spi, 0)) {
329 ret = spi_mem_access_start(mem);
330 if (ret)
331 return ret;
332
333 ret = ctlr->mem_ops->exec_op(mem, op);
334
335 spi_mem_access_end(mem);
336
337 /*
338 * Some controllers only optimize specific paths (typically the
339 * read path) and expect the core to use the regular SPI
340 * interface in other cases.
341 */
342 if (!ret || ret != -ENOTSUPP || ret != -EOPNOTSUPP)
343 return ret;
344 }
345
346 tmpbufsize = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes;
347
348 /*
349 * Allocate a buffer to transmit the CMD, ADDR cycles with kmalloc() so
350 * we're guaranteed that this buffer is DMA-able, as required by the
351 * SPI layer.
352 */
353 tmpbuf = kzalloc(tmpbufsize, GFP_KERNEL | GFP_DMA);
354 if (!tmpbuf)
355 return -ENOMEM;
356
357 spi_message_init(&msg);
358
359 tmpbuf[0] = op->cmd.opcode;
360 xfers[xferpos].tx_buf = tmpbuf;
361 xfers[xferpos].len = op->cmd.nbytes;
362 xfers[xferpos].tx_nbits = op->cmd.buswidth;
363 spi_message_add_tail(&xfers[xferpos], &msg);
364 xferpos++;
365 totalxferlen++;
366
367 if (op->addr.nbytes) {
368 int i;
369
370 for (i = 0; i < op->addr.nbytes; i++)
371 tmpbuf[i + 1] = op->addr.val >>
372 (8 * (op->addr.nbytes - i - 1));
373
374 xfers[xferpos].tx_buf = tmpbuf + 1;
375 xfers[xferpos].len = op->addr.nbytes;
376 xfers[xferpos].tx_nbits = op->addr.buswidth;
377 spi_message_add_tail(&xfers[xferpos], &msg);
378 xferpos++;
379 totalxferlen += op->addr.nbytes;
380 }
381
382 if (op->dummy.nbytes) {
383 memset(tmpbuf + op->addr.nbytes + 1, 0xff, op->dummy.nbytes);
384 xfers[xferpos].tx_buf = tmpbuf + op->addr.nbytes + 1;
385 xfers[xferpos].len = op->dummy.nbytes;
386 xfers[xferpos].tx_nbits = op->dummy.buswidth;
387 xfers[xferpos].dummy_data = 1;
388 spi_message_add_tail(&xfers[xferpos], &msg);
389 xferpos++;
390 totalxferlen += op->dummy.nbytes;
391 }
392
393 if (op->data.nbytes) {
394 if (op->data.dir == SPI_MEM_DATA_IN) {
395 xfers[xferpos].rx_buf = op->data.buf.in;
396 xfers[xferpos].rx_nbits = op->data.buswidth;
397 } else {
398 xfers[xferpos].tx_buf = op->data.buf.out;
399 xfers[xferpos].tx_nbits = op->data.buswidth;
400 }
401
402 xfers[xferpos].len = op->data.nbytes;
403 spi_message_add_tail(&xfers[xferpos], &msg);
404 xferpos++;
405 totalxferlen += op->data.nbytes;
406 }
407
408 ret = spi_sync(mem->spi, &msg);
409
410 kfree(tmpbuf);
411
412 if (ret)
413 return ret;
414
415 if (msg.actual_length != totalxferlen)
416 return -EIO;
417
418 return 0;
419}
420EXPORT_SYMBOL_GPL(spi_mem_exec_op);
421
422/**
423 * spi_mem_get_name() - Return the SPI mem device name to be used by the
424 * upper layer if necessary
425 * @mem: the SPI memory
426 *
427 * This function allows SPI mem users to retrieve the SPI mem device name.
428 * It is useful if the upper layer needs to expose a custom name for
429 * compatibility reasons.
430 *
431 * Return: a string containing the name of the memory device to be used
432 * by the SPI mem user
433 */
434const char *spi_mem_get_name(struct spi_mem *mem)
435{
436 return mem->name;
437}
438EXPORT_SYMBOL_GPL(spi_mem_get_name);
439
440/**
441 * spi_mem_adjust_op_size() - Adjust the data size of a SPI mem operation to
442 * match controller limitations
443 * @mem: the SPI memory
444 * @op: the operation to adjust
445 *
446 * Some controllers have FIFO limitations and must split a data transfer
447 * operation into multiple ones, others require a specific alignment for
448 * optimized accesses. This function allows SPI mem drivers to split a single
449 * operation into multiple sub-operations when required.
450 *
451 * Return: a negative error code if the controller can't properly adjust @op,
452 * 0 otherwise. Note that @op->data.nbytes will be updated if @op
453 * can't be handled in a single step.
454 */
455int spi_mem_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
456{
457 struct spi_controller *ctlr = mem->spi->controller;
458 size_t len;
459
460 if (ctlr->mem_ops && ctlr->mem_ops->adjust_op_size)
461 return ctlr->mem_ops->adjust_op_size(mem, op);
462
463 if (!ctlr->mem_ops || !ctlr->mem_ops->exec_op) {
464 len = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes;
465
466 if (len > spi_max_transfer_size(mem->spi))
467 return -EINVAL;
468
469 op->data.nbytes = min3((size_t)op->data.nbytes,
470 spi_max_transfer_size(mem->spi),
471 spi_max_message_size(mem->spi) -
472 len);
473 if (!op->data.nbytes)
474 return -EINVAL;
475 }
476
477 return 0;
478}
479EXPORT_SYMBOL_GPL(spi_mem_adjust_op_size);
480
481static ssize_t spi_mem_no_dirmap_read(struct spi_mem_dirmap_desc *desc,
482 u64 offs, size_t len, void *buf)
483{
484 struct spi_mem_op op = desc->info.op_tmpl;
485 int ret;
486
487 op.addr.val = desc->info.offset + offs;
488 op.data.buf.in = buf;
489 op.data.nbytes = len;
490 ret = spi_mem_adjust_op_size(desc->mem, &op);
491 if (ret)
492 return ret;
493
494 ret = spi_mem_exec_op(desc->mem, &op);
495 if (ret)
496 return ret;
497
498 return op.data.nbytes;
499}
500
501static ssize_t spi_mem_no_dirmap_write(struct spi_mem_dirmap_desc *desc,
502 u64 offs, size_t len, const void *buf)
503{
504 struct spi_mem_op op = desc->info.op_tmpl;
505 int ret;
506
507 op.addr.val = desc->info.offset + offs;
508 op.data.buf.out = buf;
509 op.data.nbytes = len;
510 ret = spi_mem_adjust_op_size(desc->mem, &op);
511 if (ret)
512 return ret;
513
514 ret = spi_mem_exec_op(desc->mem, &op);
515 if (ret)
516 return ret;
517
518 return op.data.nbytes;
519}
520
521/**
522 * spi_mem_dirmap_create() - Create a direct mapping descriptor
523 * @mem: SPI mem device this direct mapping should be created for
524 * @info: direct mapping information
525 *
526 * This function is creating a direct mapping descriptor which can then be used
527 * to access the memory using spi_mem_dirmap_read() or spi_mem_dirmap_write().
528 * If the SPI controller driver does not support direct mapping, this function
529 * falls back to an implementation using spi_mem_exec_op(), so that the caller
530 * doesn't have to bother implementing a fallback on his own.
531 *
532 * Return: a valid pointer in case of success, and ERR_PTR() otherwise.
533 */
534struct spi_mem_dirmap_desc *
535spi_mem_dirmap_create(struct spi_mem *mem,
536 const struct spi_mem_dirmap_info *info)
537{
538 struct spi_controller *ctlr = mem->spi->controller;
539 struct spi_mem_dirmap_desc *desc;
540 int ret = -ENOTSUPP;
541
542 /* Make sure the number of address cycles is between 1 and 8 bytes. */
543 if (!info->op_tmpl.addr.nbytes || info->op_tmpl.addr.nbytes > 8)
544 return ERR_PTR(-EINVAL);
545
546 /* data.dir should either be SPI_MEM_DATA_IN or SPI_MEM_DATA_OUT. */
547 if (info->op_tmpl.data.dir == SPI_MEM_NO_DATA)
548 return ERR_PTR(-EINVAL);
549
550 desc = kzalloc(sizeof(*desc), GFP_KERNEL);
551 if (!desc)
552 return ERR_PTR(-ENOMEM);
553
554 desc->mem = mem;
555 desc->info = *info;
556 if (ctlr->mem_ops && ctlr->mem_ops->dirmap_create)
557 ret = ctlr->mem_ops->dirmap_create(desc);
558
559 if (ret) {
560 desc->nodirmap = true;
561 if (!spi_mem_supports_op(desc->mem, &desc->info.op_tmpl))
562 ret = -EOPNOTSUPP;
563 else
564 ret = 0;
565 }
566
567 if (ret) {
568 kfree(desc);
569 return ERR_PTR(ret);
570 }
571
572 return desc;
573}
574EXPORT_SYMBOL_GPL(spi_mem_dirmap_create);
575
576/**
577 * spi_mem_dirmap_destroy() - Destroy a direct mapping descriptor
578 * @desc: the direct mapping descriptor to destroy
579 *
580 * This function destroys a direct mapping descriptor previously created by
581 * spi_mem_dirmap_create().
582 */
583void spi_mem_dirmap_destroy(struct spi_mem_dirmap_desc *desc)
584{
585 struct spi_controller *ctlr = desc->mem->spi->controller;
586
587 if (!desc->nodirmap && ctlr->mem_ops && ctlr->mem_ops->dirmap_destroy)
588 ctlr->mem_ops->dirmap_destroy(desc);
589
590 kfree(desc);
591}
592EXPORT_SYMBOL_GPL(spi_mem_dirmap_destroy);
593
594static void devm_spi_mem_dirmap_release(struct device *dev, void *res)
595{
596 struct spi_mem_dirmap_desc *desc = *(struct spi_mem_dirmap_desc **)res;
597
598 spi_mem_dirmap_destroy(desc);
599}
600
601/**
602 * devm_spi_mem_dirmap_create() - Create a direct mapping descriptor and attach
603 * it to a device
604 * @dev: device the dirmap desc will be attached to
605 * @mem: SPI mem device this direct mapping should be created for
606 * @info: direct mapping information
607 *
608 * devm_ variant of the spi_mem_dirmap_create() function. See
609 * spi_mem_dirmap_create() for more details.
610 *
611 * Return: a valid pointer in case of success, and ERR_PTR() otherwise.
612 */
613struct spi_mem_dirmap_desc *
614devm_spi_mem_dirmap_create(struct device *dev, struct spi_mem *mem,
615 const struct spi_mem_dirmap_info *info)
616{
617 struct spi_mem_dirmap_desc **ptr, *desc;
618
619 ptr = devres_alloc(devm_spi_mem_dirmap_release, sizeof(*ptr),
620 GFP_KERNEL);
621 if (!ptr)
622 return ERR_PTR(-ENOMEM);
623
624 desc = spi_mem_dirmap_create(mem, info);
625 if (IS_ERR(desc)) {
626 devres_free(ptr);
627 } else {
628 *ptr = desc;
629 devres_add(dev, ptr);
630 }
631
632 return desc;
633}
634EXPORT_SYMBOL_GPL(devm_spi_mem_dirmap_create);
635
636static int devm_spi_mem_dirmap_match(struct device *dev, void *res, void *data)
637{
638 struct spi_mem_dirmap_desc **ptr = res;
639
640 if (WARN_ON(!ptr || !*ptr))
641 return 0;
642
643 return *ptr == data;
644}
645
646/**
647 * devm_spi_mem_dirmap_destroy() - Destroy a direct mapping descriptor attached
648 * to a device
649 * @dev: device the dirmap desc is attached to
650 * @desc: the direct mapping descriptor to destroy
651 *
652 * devm_ variant of the spi_mem_dirmap_destroy() function. See
653 * spi_mem_dirmap_destroy() for more details.
654 */
655void devm_spi_mem_dirmap_destroy(struct device *dev,
656 struct spi_mem_dirmap_desc *desc)
657{
658 devres_release(dev, devm_spi_mem_dirmap_release,
659 devm_spi_mem_dirmap_match, desc);
660}
661EXPORT_SYMBOL_GPL(devm_spi_mem_dirmap_destroy);
662
663/**
664 * spi_mem_dirmap_read() - Read data through a direct mapping
665 * @desc: direct mapping descriptor
666 * @offs: offset to start reading from. Note that this is not an absolute
667 * offset, but the offset within the direct mapping which already has
668 * its own offset
669 * @len: length in bytes
670 * @buf: destination buffer. This buffer must be DMA-able
671 *
672 * This function reads data from a memory device using a direct mapping
673 * previously instantiated with spi_mem_dirmap_create().
674 *
675 * Return: the amount of data read from the memory device or a negative error
676 * code. Note that the returned size might be smaller than @len, and the caller
677 * is responsible for calling spi_mem_dirmap_read() again when that happens.
678 */
679ssize_t spi_mem_dirmap_read(struct spi_mem_dirmap_desc *desc,
680 u64 offs, size_t len, void *buf)
681{
682 struct spi_controller *ctlr = desc->mem->spi->controller;
683 ssize_t ret;
684
685 if (desc->info.op_tmpl.data.dir != SPI_MEM_DATA_IN)
686 return -EINVAL;
687
688 if (!len)
689 return 0;
690
691 if (desc->nodirmap) {
692 ret = spi_mem_no_dirmap_read(desc, offs, len, buf);
693 } else if (ctlr->mem_ops && ctlr->mem_ops->dirmap_read) {
694 ret = spi_mem_access_start(desc->mem);
695 if (ret)
696 return ret;
697
698 ret = ctlr->mem_ops->dirmap_read(desc, offs, len, buf);
699
700 spi_mem_access_end(desc->mem);
701 } else {
702 ret = -ENOTSUPP;
703 }
704
705 return ret;
706}
707EXPORT_SYMBOL_GPL(spi_mem_dirmap_read);
708
709/**
710 * spi_mem_dirmap_write() - Write data through a direct mapping
711 * @desc: direct mapping descriptor
712 * @offs: offset to start writing from. Note that this is not an absolute
713 * offset, but the offset within the direct mapping which already has
714 * its own offset
715 * @len: length in bytes
716 * @buf: source buffer. This buffer must be DMA-able
717 *
718 * This function writes data to a memory device using a direct mapping
719 * previously instantiated with spi_mem_dirmap_create().
720 *
721 * Return: the amount of data written to the memory device or a negative error
722 * code. Note that the returned size might be smaller than @len, and the caller
723 * is responsible for calling spi_mem_dirmap_write() again when that happens.
724 */
725ssize_t spi_mem_dirmap_write(struct spi_mem_dirmap_desc *desc,
726 u64 offs, size_t len, const void *buf)
727{
728 struct spi_controller *ctlr = desc->mem->spi->controller;
729 ssize_t ret;
730
731 if (desc->info.op_tmpl.data.dir != SPI_MEM_DATA_OUT)
732 return -EINVAL;
733
734 if (!len)
735 return 0;
736
737 if (desc->nodirmap) {
738 ret = spi_mem_no_dirmap_write(desc, offs, len, buf);
739 } else if (ctlr->mem_ops && ctlr->mem_ops->dirmap_write) {
740 ret = spi_mem_access_start(desc->mem);
741 if (ret)
742 return ret;
743
744 ret = ctlr->mem_ops->dirmap_write(desc, offs, len, buf);
745
746 spi_mem_access_end(desc->mem);
747 } else {
748 ret = -ENOTSUPP;
749 }
750
751 return ret;
752}
753EXPORT_SYMBOL_GPL(spi_mem_dirmap_write);
754
755static inline struct spi_mem_driver *to_spi_mem_drv(struct device_driver *drv)
756{
757 return container_of(drv, struct spi_mem_driver, spidrv.driver);
758}
759
760static int spi_mem_read_status(struct spi_mem *mem,
761 const struct spi_mem_op *op,
762 u16 *status)
763{
764 const u8 *bytes = (u8 *)op->data.buf.in;
765 int ret;
766
767 ret = spi_mem_exec_op(mem, op);
768 if (ret)
769 return ret;
770
771 if (op->data.nbytes > 1)
772 *status = ((u16)bytes[0] << 8) | bytes[1];
773 else
774 *status = bytes[0];
775
776 return 0;
777}
778
779/**
780 * spi_mem_poll_status() - Poll memory device status
781 * @mem: SPI memory device
782 * @op: the memory operation to execute
783 * @mask: status bitmask to ckeck
784 * @match: (status & mask) expected value
785 * @initial_delay_us: delay in us before starting to poll
786 * @polling_delay_us: time to sleep between reads in us
787 * @timeout_ms: timeout in milliseconds
788 *
789 * This function polls a status register and returns when
790 * (status & mask) == match or when the timeout has expired.
791 *
792 * Return: 0 in case of success, -ETIMEDOUT in case of error,
793 * -EOPNOTSUPP if not supported.
794 */
795int spi_mem_poll_status(struct spi_mem *mem,
796 const struct spi_mem_op *op,
797 u16 mask, u16 match,
798 unsigned long initial_delay_us,
799 unsigned long polling_delay_us,
800 u16 timeout_ms)
801{
802 struct spi_controller *ctlr = mem->spi->controller;
803 int ret = -EOPNOTSUPP;
804 int read_status_ret;
805 u16 status;
806
807 if (op->data.nbytes < 1 || op->data.nbytes > 2 ||
808 op->data.dir != SPI_MEM_DATA_IN)
809 return -EINVAL;
810
811 if (ctlr->mem_ops && ctlr->mem_ops->poll_status && !spi_get_csgpiod(mem->spi, 0)) {
812 ret = spi_mem_access_start(mem);
813 if (ret)
814 return ret;
815
816 ret = ctlr->mem_ops->poll_status(mem, op, mask, match,
817 initial_delay_us, polling_delay_us,
818 timeout_ms);
819
820 spi_mem_access_end(mem);
821 }
822
823 if (ret == -EOPNOTSUPP) {
824 if (!spi_mem_supports_op(mem, op))
825 return ret;
826
827 if (initial_delay_us < 10)
828 udelay(initial_delay_us);
829 else
830 usleep_range((initial_delay_us >> 2) + 1,
831 initial_delay_us);
832
833 ret = read_poll_timeout(spi_mem_read_status, read_status_ret,
834 (read_status_ret || ((status) & mask) == match),
835 polling_delay_us, timeout_ms * 1000, false, mem,
836 op, &status);
837 if (read_status_ret)
838 return read_status_ret;
839 }
840
841 return ret;
842}
843EXPORT_SYMBOL_GPL(spi_mem_poll_status);
844
845static int spi_mem_probe(struct spi_device *spi)
846{
847 struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
848 struct spi_controller *ctlr = spi->controller;
849 struct spi_mem *mem;
850
851 mem = devm_kzalloc(&spi->dev, sizeof(*mem), GFP_KERNEL);
852 if (!mem)
853 return -ENOMEM;
854
855 mem->spi = spi;
856
857 if (ctlr->mem_ops && ctlr->mem_ops->get_name)
858 mem->name = ctlr->mem_ops->get_name(mem);
859 else
860 mem->name = dev_name(&spi->dev);
861
862 if (IS_ERR_OR_NULL(mem->name))
863 return PTR_ERR_OR_ZERO(mem->name);
864
865 spi_set_drvdata(spi, mem);
866
867 return memdrv->probe(mem);
868}
869
870static void spi_mem_remove(struct spi_device *spi)
871{
872 struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
873 struct spi_mem *mem = spi_get_drvdata(spi);
874
875 if (memdrv->remove)
876 memdrv->remove(mem);
877}
878
879static void spi_mem_shutdown(struct spi_device *spi)
880{
881 struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
882 struct spi_mem *mem = spi_get_drvdata(spi);
883
884 if (memdrv->shutdown)
885 memdrv->shutdown(mem);
886}
887
888/**
889 * spi_mem_driver_register_with_owner() - Register a SPI memory driver
890 * @memdrv: the SPI memory driver to register
891 * @owner: the owner of this driver
892 *
893 * Registers a SPI memory driver.
894 *
895 * Return: 0 in case of success, a negative error core otherwise.
896 */
897
898int spi_mem_driver_register_with_owner(struct spi_mem_driver *memdrv,
899 struct module *owner)
900{
901 memdrv->spidrv.probe = spi_mem_probe;
902 memdrv->spidrv.remove = spi_mem_remove;
903 memdrv->spidrv.shutdown = spi_mem_shutdown;
904
905 return __spi_register_driver(owner, &memdrv->spidrv);
906}
907EXPORT_SYMBOL_GPL(spi_mem_driver_register_with_owner);
908
909/**
910 * spi_mem_driver_unregister() - Unregister a SPI memory driver
911 * @memdrv: the SPI memory driver to unregister
912 *
913 * Unregisters a SPI memory driver.
914 */
915void spi_mem_driver_unregister(struct spi_mem_driver *memdrv)
916{
917 spi_unregister_driver(&memdrv->spidrv);
918}
919EXPORT_SYMBOL_GPL(spi_mem_driver_unregister);