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->data.swap16 && !spi_mem_controller_is_capable(ctlr, swap16))
176			return false;
177
178		if (op->cmd.nbytes != 2)
179			return false;
180	} else {
181		if (op->cmd.nbytes != 1)
182			return false;
183	}
184
185	if (op->data.ecc) {
186		if (!spi_mem_controller_is_capable(ctlr, ecc))
187			return false;
188	}
189
190	return spi_mem_check_buswidth(mem, op);
191}
192EXPORT_SYMBOL_GPL(spi_mem_default_supports_op);
193
194static bool spi_mem_buswidth_is_valid(u8 buswidth)
195{
196	if (hweight8(buswidth) > 1 || buswidth > SPI_MEM_MAX_BUSWIDTH)
197		return false;
198
199	return true;
200}
201
202static int spi_mem_check_op(const struct spi_mem_op *op)
203{
204	if (!op->cmd.buswidth || !op->cmd.nbytes)
205		return -EINVAL;
206
207	if ((op->addr.nbytes && !op->addr.buswidth) ||
208	    (op->dummy.nbytes && !op->dummy.buswidth) ||
209	    (op->data.nbytes && !op->data.buswidth))
210		return -EINVAL;
211
212	if (!spi_mem_buswidth_is_valid(op->cmd.buswidth) ||
213	    !spi_mem_buswidth_is_valid(op->addr.buswidth) ||
214	    !spi_mem_buswidth_is_valid(op->dummy.buswidth) ||
215	    !spi_mem_buswidth_is_valid(op->data.buswidth))
216		return -EINVAL;
217
218	/* Buffers must be DMA-able. */
219	if (WARN_ON_ONCE(op->data.dir == SPI_MEM_DATA_IN &&
220			 object_is_on_stack(op->data.buf.in)))
221		return -EINVAL;
222
223	if (WARN_ON_ONCE(op->data.dir == SPI_MEM_DATA_OUT &&
224			 object_is_on_stack(op->data.buf.out)))
225		return -EINVAL;
226
227	return 0;
228}
229
230static bool spi_mem_internal_supports_op(struct spi_mem *mem,
231					 const struct spi_mem_op *op)
232{
233	struct spi_controller *ctlr = mem->spi->controller;
234
235	if (ctlr->mem_ops && ctlr->mem_ops->supports_op)
236		return ctlr->mem_ops->supports_op(mem, op);
237
238	return spi_mem_default_supports_op(mem, op);
239}
240
241/**
242 * spi_mem_supports_op() - Check if a memory device and the controller it is
243 *			   connected to support a specific memory operation
244 * @mem: the SPI memory
245 * @op: the memory operation to check
246 *
247 * Some controllers are only supporting Single or Dual IOs, others might only
248 * support specific opcodes, or it can even be that the controller and device
249 * both support Quad IOs but the hardware prevents you from using it because
250 * only 2 IO lines are connected.
251 *
252 * This function checks whether a specific operation is supported.
253 *
254 * Return: true if @op is supported, false otherwise.
255 */
256bool spi_mem_supports_op(struct spi_mem *mem, const struct spi_mem_op *op)
257{
258	if (spi_mem_check_op(op))
259		return false;
260
261	return spi_mem_internal_supports_op(mem, op);
262}
263EXPORT_SYMBOL_GPL(spi_mem_supports_op);
264
265static int spi_mem_access_start(struct spi_mem *mem)
266{
267	struct spi_controller *ctlr = mem->spi->controller;
268
269	/*
270	 * Flush the message queue before executing our SPI memory
271	 * operation to prevent preemption of regular SPI transfers.
272	 */
273	spi_flush_queue(ctlr);
274
275	if (ctlr->auto_runtime_pm) {
276		int ret;
277
278		ret = pm_runtime_resume_and_get(ctlr->dev.parent);
279		if (ret < 0) {
280			dev_err(&ctlr->dev, "Failed to power device: %d\n",
281				ret);
282			return ret;
283		}
284	}
285
286	mutex_lock(&ctlr->bus_lock_mutex);
287	mutex_lock(&ctlr->io_mutex);
288
289	return 0;
290}
291
292static void spi_mem_access_end(struct spi_mem *mem)
293{
294	struct spi_controller *ctlr = mem->spi->controller;
295
296	mutex_unlock(&ctlr->io_mutex);
297	mutex_unlock(&ctlr->bus_lock_mutex);
298
299	if (ctlr->auto_runtime_pm)
300		pm_runtime_put(ctlr->dev.parent);
301}
302
303static void spi_mem_add_op_stats(struct spi_statistics __percpu *pcpu_stats,
304				 const struct spi_mem_op *op, int exec_op_ret)
305{
306	struct spi_statistics *stats;
307	u64 len, l2len;
308
309	get_cpu();
310	stats = this_cpu_ptr(pcpu_stats);
311	u64_stats_update_begin(&stats->syncp);
312
313	/*
314	 * We do not have the concept of messages or transfers. Let's consider
315	 * that one operation is equivalent to one message and one transfer.
316	 */
317	u64_stats_inc(&stats->messages);
318	u64_stats_inc(&stats->transfers);
319
320	/* Use the sum of all lengths as bytes count and histogram value. */
321	len = op->cmd.nbytes + op->addr.nbytes;
322	len += op->dummy.nbytes + op->data.nbytes;
323	u64_stats_add(&stats->bytes, len);
324	l2len = min(fls(len), SPI_STATISTICS_HISTO_SIZE) - 1;
325	u64_stats_inc(&stats->transfer_bytes_histo[l2len]);
326
327	/* Only account for data bytes as transferred bytes. */
328	if (op->data.nbytes && op->data.dir == SPI_MEM_DATA_OUT)
329		u64_stats_add(&stats->bytes_tx, op->data.nbytes);
330	if (op->data.nbytes && op->data.dir == SPI_MEM_DATA_IN)
331		u64_stats_add(&stats->bytes_rx, op->data.nbytes);
332
333	/*
334	 * A timeout is not an error, following the same behavior as
335	 * spi_transfer_one_message().
336	 */
337	if (exec_op_ret == -ETIMEDOUT)
338		u64_stats_inc(&stats->timedout);
339	else if (exec_op_ret)
340		u64_stats_inc(&stats->errors);
341
342	u64_stats_update_end(&stats->syncp);
343	put_cpu();
344}
345
346/**
347 * spi_mem_exec_op() - Execute a memory operation
348 * @mem: the SPI memory
349 * @op: the memory operation to execute
350 *
351 * Executes a memory operation.
352 *
353 * This function first checks that @op is supported and then tries to execute
354 * it.
355 *
356 * Return: 0 in case of success, a negative error code otherwise.
357 */
358int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
359{
360	unsigned int tmpbufsize, xferpos = 0, totalxferlen = 0;
361	struct spi_controller *ctlr = mem->spi->controller;
362	struct spi_transfer xfers[4] = { };
363	struct spi_message msg;
364	u8 *tmpbuf;
365	int ret;
366
367	ret = spi_mem_check_op(op);
368	if (ret)
369		return ret;
370
371	if (!spi_mem_internal_supports_op(mem, op))
372		return -EOPNOTSUPP;
373
374	if (ctlr->mem_ops && ctlr->mem_ops->exec_op && !spi_get_csgpiod(mem->spi, 0)) {
375		ret = spi_mem_access_start(mem);
376		if (ret)
377			return ret;
378
379		ret = ctlr->mem_ops->exec_op(mem, op);
380
381		spi_mem_access_end(mem);
382
383		/*
384		 * Some controllers only optimize specific paths (typically the
385		 * read path) and expect the core to use the regular SPI
386		 * interface in other cases.
387		 */
388		if (!ret || (ret != -ENOTSUPP && ret != -EOPNOTSUPP)) {
389			spi_mem_add_op_stats(ctlr->pcpu_statistics, op, ret);
390			spi_mem_add_op_stats(mem->spi->pcpu_statistics, op, ret);
391
392			return ret;
393		}
394	}
395
396	tmpbufsize = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes;
397
398	/*
399	 * Allocate a buffer to transmit the CMD, ADDR cycles with kmalloc() so
400	 * we're guaranteed that this buffer is DMA-able, as required by the
401	 * SPI layer.
402	 */
403	tmpbuf = kzalloc(tmpbufsize, GFP_KERNEL | GFP_DMA);
404	if (!tmpbuf)
405		return -ENOMEM;
406
407	spi_message_init(&msg);
408
409	tmpbuf[0] = op->cmd.opcode;
410	xfers[xferpos].tx_buf = tmpbuf;
411	xfers[xferpos].len = op->cmd.nbytes;
412	xfers[xferpos].tx_nbits = op->cmd.buswidth;
413	spi_message_add_tail(&xfers[xferpos], &msg);
414	xferpos++;
415	totalxferlen++;
416
417	if (op->addr.nbytes) {
418		int i;
419
420		for (i = 0; i < op->addr.nbytes; i++)
421			tmpbuf[i + 1] = op->addr.val >>
422					(8 * (op->addr.nbytes - i - 1));
423
424		xfers[xferpos].tx_buf = tmpbuf + 1;
425		xfers[xferpos].len = op->addr.nbytes;
426		xfers[xferpos].tx_nbits = op->addr.buswidth;
427		spi_message_add_tail(&xfers[xferpos], &msg);
428		xferpos++;
429		totalxferlen += op->addr.nbytes;
430	}
431
432	if (op->dummy.nbytes) {
433		memset(tmpbuf + op->addr.nbytes + 1, 0xff, op->dummy.nbytes);
434		xfers[xferpos].tx_buf = tmpbuf + op->addr.nbytes + 1;
435		xfers[xferpos].len = op->dummy.nbytes;
436		xfers[xferpos].tx_nbits = op->dummy.buswidth;
437		xfers[xferpos].dummy_data = 1;
438		spi_message_add_tail(&xfers[xferpos], &msg);
439		xferpos++;
440		totalxferlen += op->dummy.nbytes;
441	}
442
443	if (op->data.nbytes) {
444		if (op->data.dir == SPI_MEM_DATA_IN) {
445			xfers[xferpos].rx_buf = op->data.buf.in;
446			xfers[xferpos].rx_nbits = op->data.buswidth;
447		} else {
448			xfers[xferpos].tx_buf = op->data.buf.out;
449			xfers[xferpos].tx_nbits = op->data.buswidth;
450		}
451
452		xfers[xferpos].len = op->data.nbytes;
453		spi_message_add_tail(&xfers[xferpos], &msg);
454		xferpos++;
455		totalxferlen += op->data.nbytes;
456	}
457
458	ret = spi_sync(mem->spi, &msg);
459
460	kfree(tmpbuf);
461
462	if (ret)
463		return ret;
464
465	if (msg.actual_length != totalxferlen)
466		return -EIO;
467
468	return 0;
469}
470EXPORT_SYMBOL_GPL(spi_mem_exec_op);
471
472/**
473 * spi_mem_get_name() - Return the SPI mem device name to be used by the
474 *			upper layer if necessary
475 * @mem: the SPI memory
476 *
477 * This function allows SPI mem users to retrieve the SPI mem device name.
478 * It is useful if the upper layer needs to expose a custom name for
479 * compatibility reasons.
480 *
481 * Return: a string containing the name of the memory device to be used
482 *	   by the SPI mem user
483 */
484const char *spi_mem_get_name(struct spi_mem *mem)
485{
486	return mem->name;
487}
488EXPORT_SYMBOL_GPL(spi_mem_get_name);
489
490/**
491 * spi_mem_adjust_op_size() - Adjust the data size of a SPI mem operation to
492 *			      match controller limitations
493 * @mem: the SPI memory
494 * @op: the operation to adjust
495 *
496 * Some controllers have FIFO limitations and must split a data transfer
497 * operation into multiple ones, others require a specific alignment for
498 * optimized accesses. This function allows SPI mem drivers to split a single
499 * operation into multiple sub-operations when required.
500 *
501 * Return: a negative error code if the controller can't properly adjust @op,
502 *	   0 otherwise. Note that @op->data.nbytes will be updated if @op
503 *	   can't be handled in a single step.
504 */
505int spi_mem_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
506{
507	struct spi_controller *ctlr = mem->spi->controller;
508	size_t len;
509
510	if (ctlr->mem_ops && ctlr->mem_ops->adjust_op_size)
511		return ctlr->mem_ops->adjust_op_size(mem, op);
512
513	if (!ctlr->mem_ops || !ctlr->mem_ops->exec_op) {
514		len = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes;
515
516		if (len > spi_max_transfer_size(mem->spi))
517			return -EINVAL;
518
519		op->data.nbytes = min3((size_t)op->data.nbytes,
520				       spi_max_transfer_size(mem->spi),
521				       spi_max_message_size(mem->spi) -
522				       len);
523		if (!op->data.nbytes)
524			return -EINVAL;
525	}
526
527	return 0;
528}
529EXPORT_SYMBOL_GPL(spi_mem_adjust_op_size);
530
531static ssize_t spi_mem_no_dirmap_read(struct spi_mem_dirmap_desc *desc,
532				      u64 offs, size_t len, void *buf)
533{
534	struct spi_mem_op op = desc->info.op_tmpl;
535	int ret;
536
537	op.addr.val = desc->info.offset + offs;
538	op.data.buf.in = buf;
539	op.data.nbytes = len;
540	ret = spi_mem_adjust_op_size(desc->mem, &op);
541	if (ret)
542		return ret;
543
544	ret = spi_mem_exec_op(desc->mem, &op);
545	if (ret)
546		return ret;
547
548	return op.data.nbytes;
549}
550
551static ssize_t spi_mem_no_dirmap_write(struct spi_mem_dirmap_desc *desc,
552				       u64 offs, size_t len, const void *buf)
553{
554	struct spi_mem_op op = desc->info.op_tmpl;
555	int ret;
556
557	op.addr.val = desc->info.offset + offs;
558	op.data.buf.out = buf;
559	op.data.nbytes = len;
560	ret = spi_mem_adjust_op_size(desc->mem, &op);
561	if (ret)
562		return ret;
563
564	ret = spi_mem_exec_op(desc->mem, &op);
565	if (ret)
566		return ret;
567
568	return op.data.nbytes;
569}
570
571/**
572 * spi_mem_dirmap_create() - Create a direct mapping descriptor
573 * @mem: SPI mem device this direct mapping should be created for
574 * @info: direct mapping information
575 *
576 * This function is creating a direct mapping descriptor which can then be used
577 * to access the memory using spi_mem_dirmap_read() or spi_mem_dirmap_write().
578 * If the SPI controller driver does not support direct mapping, this function
579 * falls back to an implementation using spi_mem_exec_op(), so that the caller
580 * doesn't have to bother implementing a fallback on his own.
581 *
582 * Return: a valid pointer in case of success, and ERR_PTR() otherwise.
583 */
584struct spi_mem_dirmap_desc *
585spi_mem_dirmap_create(struct spi_mem *mem,
586		      const struct spi_mem_dirmap_info *info)
587{
588	struct spi_controller *ctlr = mem->spi->controller;
589	struct spi_mem_dirmap_desc *desc;
590	int ret = -ENOTSUPP;
591
592	/* Make sure the number of address cycles is between 1 and 8 bytes. */
593	if (!info->op_tmpl.addr.nbytes || info->op_tmpl.addr.nbytes > 8)
594		return ERR_PTR(-EINVAL);
595
596	/* data.dir should either be SPI_MEM_DATA_IN or SPI_MEM_DATA_OUT. */
597	if (info->op_tmpl.data.dir == SPI_MEM_NO_DATA)
598		return ERR_PTR(-EINVAL);
599
600	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
601	if (!desc)
602		return ERR_PTR(-ENOMEM);
603
604	desc->mem = mem;
605	desc->info = *info;
606	if (ctlr->mem_ops && ctlr->mem_ops->dirmap_create)
607		ret = ctlr->mem_ops->dirmap_create(desc);
608
609	if (ret) {
610		desc->nodirmap = true;
611		if (!spi_mem_supports_op(desc->mem, &desc->info.op_tmpl))
612			ret = -EOPNOTSUPP;
613		else
614			ret = 0;
615	}
616
617	if (ret) {
618		kfree(desc);
619		return ERR_PTR(ret);
620	}
621
622	return desc;
623}
624EXPORT_SYMBOL_GPL(spi_mem_dirmap_create);
625
626/**
627 * spi_mem_dirmap_destroy() - Destroy a direct mapping descriptor
628 * @desc: the direct mapping descriptor to destroy
629 *
630 * This function destroys a direct mapping descriptor previously created by
631 * spi_mem_dirmap_create().
632 */
633void spi_mem_dirmap_destroy(struct spi_mem_dirmap_desc *desc)
634{
635	struct spi_controller *ctlr = desc->mem->spi->controller;
636
637	if (!desc->nodirmap && ctlr->mem_ops && ctlr->mem_ops->dirmap_destroy)
638		ctlr->mem_ops->dirmap_destroy(desc);
639
640	kfree(desc);
641}
642EXPORT_SYMBOL_GPL(spi_mem_dirmap_destroy);
643
644static void devm_spi_mem_dirmap_release(struct device *dev, void *res)
645{
646	struct spi_mem_dirmap_desc *desc = *(struct spi_mem_dirmap_desc **)res;
647
648	spi_mem_dirmap_destroy(desc);
649}
650
651/**
652 * devm_spi_mem_dirmap_create() - Create a direct mapping descriptor and attach
653 *				  it to a device
654 * @dev: device the dirmap desc will be attached to
655 * @mem: SPI mem device this direct mapping should be created for
656 * @info: direct mapping information
657 *
658 * devm_ variant of the spi_mem_dirmap_create() function. See
659 * spi_mem_dirmap_create() for more details.
660 *
661 * Return: a valid pointer in case of success, and ERR_PTR() otherwise.
662 */
663struct spi_mem_dirmap_desc *
664devm_spi_mem_dirmap_create(struct device *dev, struct spi_mem *mem,
665			   const struct spi_mem_dirmap_info *info)
666{
667	struct spi_mem_dirmap_desc **ptr, *desc;
668
669	ptr = devres_alloc(devm_spi_mem_dirmap_release, sizeof(*ptr),
670			   GFP_KERNEL);
671	if (!ptr)
672		return ERR_PTR(-ENOMEM);
673
674	desc = spi_mem_dirmap_create(mem, info);
675	if (IS_ERR(desc)) {
676		devres_free(ptr);
677	} else {
678		*ptr = desc;
679		devres_add(dev, ptr);
680	}
681
682	return desc;
683}
684EXPORT_SYMBOL_GPL(devm_spi_mem_dirmap_create);
685
686static int devm_spi_mem_dirmap_match(struct device *dev, void *res, void *data)
687{
688	struct spi_mem_dirmap_desc **ptr = res;
689
690	if (WARN_ON(!ptr || !*ptr))
691		return 0;
692
693	return *ptr == data;
694}
695
696/**
697 * devm_spi_mem_dirmap_destroy() - Destroy a direct mapping descriptor attached
698 *				   to a device
699 * @dev: device the dirmap desc is attached to
700 * @desc: the direct mapping descriptor to destroy
701 *
702 * devm_ variant of the spi_mem_dirmap_destroy() function. See
703 * spi_mem_dirmap_destroy() for more details.
704 */
705void devm_spi_mem_dirmap_destroy(struct device *dev,
706				 struct spi_mem_dirmap_desc *desc)
707{
708	devres_release(dev, devm_spi_mem_dirmap_release,
709		       devm_spi_mem_dirmap_match, desc);
710}
711EXPORT_SYMBOL_GPL(devm_spi_mem_dirmap_destroy);
712
713/**
714 * spi_mem_dirmap_read() - Read data through a direct mapping
715 * @desc: direct mapping descriptor
716 * @offs: offset to start reading from. Note that this is not an absolute
717 *	  offset, but the offset within the direct mapping which already has
718 *	  its own offset
719 * @len: length in bytes
720 * @buf: destination buffer. This buffer must be DMA-able
721 *
722 * This function reads data from a memory device using a direct mapping
723 * previously instantiated with spi_mem_dirmap_create().
724 *
725 * Return: the amount of data read from the memory device or a negative error
726 * code. Note that the returned size might be smaller than @len, and the caller
727 * is responsible for calling spi_mem_dirmap_read() again when that happens.
728 */
729ssize_t spi_mem_dirmap_read(struct spi_mem_dirmap_desc *desc,
730			    u64 offs, size_t len, void *buf)
731{
732	struct spi_controller *ctlr = desc->mem->spi->controller;
733	ssize_t ret;
734
735	if (desc->info.op_tmpl.data.dir != SPI_MEM_DATA_IN)
736		return -EINVAL;
737
738	if (!len)
739		return 0;
740
741	if (desc->nodirmap) {
742		ret = spi_mem_no_dirmap_read(desc, offs, len, buf);
743	} else if (ctlr->mem_ops && ctlr->mem_ops->dirmap_read) {
744		ret = spi_mem_access_start(desc->mem);
745		if (ret)
746			return ret;
747
748		ret = ctlr->mem_ops->dirmap_read(desc, offs, len, buf);
749
750		spi_mem_access_end(desc->mem);
751	} else {
752		ret = -ENOTSUPP;
753	}
754
755	return ret;
756}
757EXPORT_SYMBOL_GPL(spi_mem_dirmap_read);
758
759/**
760 * spi_mem_dirmap_write() - Write data through a direct mapping
761 * @desc: direct mapping descriptor
762 * @offs: offset to start writing from. Note that this is not an absolute
763 *	  offset, but the offset within the direct mapping which already has
764 *	  its own offset
765 * @len: length in bytes
766 * @buf: source buffer. This buffer must be DMA-able
767 *
768 * This function writes data to a memory device using a direct mapping
769 * previously instantiated with spi_mem_dirmap_create().
770 *
771 * Return: the amount of data written to the memory device or a negative error
772 * code. Note that the returned size might be smaller than @len, and the caller
773 * is responsible for calling spi_mem_dirmap_write() again when that happens.
774 */
775ssize_t spi_mem_dirmap_write(struct spi_mem_dirmap_desc *desc,
776			     u64 offs, size_t len, const void *buf)
777{
778	struct spi_controller *ctlr = desc->mem->spi->controller;
779	ssize_t ret;
780
781	if (desc->info.op_tmpl.data.dir != SPI_MEM_DATA_OUT)
782		return -EINVAL;
783
784	if (!len)
785		return 0;
786
787	if (desc->nodirmap) {
788		ret = spi_mem_no_dirmap_write(desc, offs, len, buf);
789	} else if (ctlr->mem_ops && ctlr->mem_ops->dirmap_write) {
790		ret = spi_mem_access_start(desc->mem);
791		if (ret)
792			return ret;
793
794		ret = ctlr->mem_ops->dirmap_write(desc, offs, len, buf);
795
796		spi_mem_access_end(desc->mem);
797	} else {
798		ret = -ENOTSUPP;
799	}
800
801	return ret;
802}
803EXPORT_SYMBOL_GPL(spi_mem_dirmap_write);
804
805static inline struct spi_mem_driver *to_spi_mem_drv(struct device_driver *drv)
806{
807	return container_of(drv, struct spi_mem_driver, spidrv.driver);
808}
809
810static int spi_mem_read_status(struct spi_mem *mem,
811			       const struct spi_mem_op *op,
812			       u16 *status)
813{
814	const u8 *bytes = (u8 *)op->data.buf.in;
815	int ret;
816
817	ret = spi_mem_exec_op(mem, op);
818	if (ret)
819		return ret;
820
821	if (op->data.nbytes > 1)
822		*status = ((u16)bytes[0] << 8) | bytes[1];
823	else
824		*status = bytes[0];
825
826	return 0;
827}
828
829/**
830 * spi_mem_poll_status() - Poll memory device status
831 * @mem: SPI memory device
832 * @op: the memory operation to execute
833 * @mask: status bitmask to ckeck
834 * @match: (status & mask) expected value
835 * @initial_delay_us: delay in us before starting to poll
836 * @polling_delay_us: time to sleep between reads in us
837 * @timeout_ms: timeout in milliseconds
838 *
839 * This function polls a status register and returns when
840 * (status & mask) == match or when the timeout has expired.
841 *
842 * Return: 0 in case of success, -ETIMEDOUT in case of error,
843 *         -EOPNOTSUPP if not supported.
844 */
845int spi_mem_poll_status(struct spi_mem *mem,
846			const struct spi_mem_op *op,
847			u16 mask, u16 match,
848			unsigned long initial_delay_us,
849			unsigned long polling_delay_us,
850			u16 timeout_ms)
851{
852	struct spi_controller *ctlr = mem->spi->controller;
853	int ret = -EOPNOTSUPP;
854	int read_status_ret;
855	u16 status;
856
857	if (op->data.nbytes < 1 || op->data.nbytes > 2 ||
858	    op->data.dir != SPI_MEM_DATA_IN)
859		return -EINVAL;
860
861	if (ctlr->mem_ops && ctlr->mem_ops->poll_status && !spi_get_csgpiod(mem->spi, 0)) {
862		ret = spi_mem_access_start(mem);
863		if (ret)
864			return ret;
865
866		ret = ctlr->mem_ops->poll_status(mem, op, mask, match,
867						 initial_delay_us, polling_delay_us,
868						 timeout_ms);
869
870		spi_mem_access_end(mem);
871	}
872
873	if (ret == -EOPNOTSUPP) {
874		if (!spi_mem_supports_op(mem, op))
875			return ret;
876
877		if (initial_delay_us < 10)
878			udelay(initial_delay_us);
879		else
880			usleep_range((initial_delay_us >> 2) + 1,
881				     initial_delay_us);
882
883		ret = read_poll_timeout(spi_mem_read_status, read_status_ret,
884					(read_status_ret || ((status) & mask) == match),
885					polling_delay_us, timeout_ms * 1000, false, mem,
886					op, &status);
887		if (read_status_ret)
888			return read_status_ret;
889	}
890
891	return ret;
892}
893EXPORT_SYMBOL_GPL(spi_mem_poll_status);
894
895static int spi_mem_probe(struct spi_device *spi)
896{
897	struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
898	struct spi_controller *ctlr = spi->controller;
899	struct spi_mem *mem;
900
901	mem = devm_kzalloc(&spi->dev, sizeof(*mem), GFP_KERNEL);
902	if (!mem)
903		return -ENOMEM;
904
905	mem->spi = spi;
906
907	if (ctlr->mem_ops && ctlr->mem_ops->get_name)
908		mem->name = ctlr->mem_ops->get_name(mem);
909	else
910		mem->name = dev_name(&spi->dev);
911
912	if (IS_ERR_OR_NULL(mem->name))
913		return PTR_ERR_OR_ZERO(mem->name);
914
915	spi_set_drvdata(spi, mem);
916
917	return memdrv->probe(mem);
918}
919
920static void spi_mem_remove(struct spi_device *spi)
921{
922	struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
923	struct spi_mem *mem = spi_get_drvdata(spi);
924
925	if (memdrv->remove)
926		memdrv->remove(mem);
927}
928
929static void spi_mem_shutdown(struct spi_device *spi)
930{
931	struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
932	struct spi_mem *mem = spi_get_drvdata(spi);
933
934	if (memdrv->shutdown)
935		memdrv->shutdown(mem);
936}
937
938/**
939 * spi_mem_driver_register_with_owner() - Register a SPI memory driver
940 * @memdrv: the SPI memory driver to register
941 * @owner: the owner of this driver
942 *
943 * Registers a SPI memory driver.
944 *
945 * Return: 0 in case of success, a negative error core otherwise.
946 */
947
948int spi_mem_driver_register_with_owner(struct spi_mem_driver *memdrv,
949				       struct module *owner)
950{
951	memdrv->spidrv.probe = spi_mem_probe;
952	memdrv->spidrv.remove = spi_mem_remove;
953	memdrv->spidrv.shutdown = spi_mem_shutdown;
954
955	return __spi_register_driver(owner, &memdrv->spidrv);
956}
957EXPORT_SYMBOL_GPL(spi_mem_driver_register_with_owner);
958
959/**
960 * spi_mem_driver_unregister() - Unregister a SPI memory driver
961 * @memdrv: the SPI memory driver to unregister
962 *
963 * Unregisters a SPI memory driver.
964 */
965void spi_mem_driver_unregister(struct spi_mem_driver *memdrv)
966{
967	spi_unregister_driver(&memdrv->spidrv);
968}
969EXPORT_SYMBOL_GPL(spi_mem_driver_unregister);