1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright (C) 2018 Exceet Electronics GmbH
4 * Copyright (C) 2018 Bootlin
6 * Author: Boris Brezillon <boris.brezillon@bootlin.com>
8 #include <linux/dmaengine.h>
9 #include <linux/pm_runtime.h>
10 #include <linux/spi/spi.h>
11 #include <linux/spi/spi-mem.h>
13 #include "internals.h"
15 #define SPI_MEM_MAX_BUSWIDTH 8
18 * spi_controller_dma_map_mem_op_data() - DMA-map the buffer attached to a
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
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.
32 * Return: 0 in case of success, a negative error code otherwise.
34 int spi_controller_dma_map_mem_op_data(struct spi_controller *ctlr,
35 const struct spi_mem_op *op,
38 struct device *dmadev;
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;
48 dmadev = ctlr->dev.parent;
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);
57 EXPORT_SYMBOL_GPL(spi_controller_dma_map_mem_op_data);
60 * spi_controller_dma_unmap_mem_op_data() - DMA-unmap the buffer attached to a
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()
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.
71 * This function is not intended to be called from SPI drivers. Only SPI
72 * controller drivers should use it.
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
78 * Return: 0 in case of success, a negative error code otherwise.
80 void spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr,
81 const struct spi_mem_op *op,
84 struct device *dmadev;
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;
94 dmadev = ctlr->dev.parent;
96 spi_unmap_buf(ctlr, dmadev, sgt,
97 op->data.dir == SPI_MEM_DATA_IN ?
98 DMA_FROM_DEVICE : DMA_TO_DEVICE);
100 EXPORT_SYMBOL_GPL(spi_controller_dma_unmap_mem_op_data);
102 static int spi_check_buswidth_req(struct spi_mem *mem, u8 buswidth, bool tx)
104 u32 mode = mem->spi->mode;
111 if ((tx && (mode & (SPI_TX_DUAL | SPI_TX_QUAD))) ||
112 (!tx && (mode & (SPI_RX_DUAL | SPI_RX_QUAD))))
118 if ((tx && (mode & SPI_TX_QUAD)) ||
119 (!tx && (mode & SPI_RX_QUAD)))
125 if ((tx && (mode & SPI_TX_OCTAL)) ||
126 (!tx && (mode & SPI_RX_OCTAL)))
138 static bool spi_mem_default_supports_op(struct spi_mem *mem,
139 const struct spi_mem_op *op)
141 if (spi_check_buswidth_req(mem, op->cmd.buswidth, true))
144 if (op->addr.nbytes &&
145 spi_check_buswidth_req(mem, op->addr.buswidth, true))
148 if (op->dummy.nbytes &&
149 spi_check_buswidth_req(mem, op->dummy.buswidth, true))
152 if (op->data.dir != SPI_MEM_NO_DATA &&
153 spi_check_buswidth_req(mem, op->data.buswidth,
154 op->data.dir == SPI_MEM_DATA_OUT))
159 EXPORT_SYMBOL_GPL(spi_mem_default_supports_op);
161 static bool spi_mem_buswidth_is_valid(u8 buswidth)
163 if (hweight8(buswidth) > 1 || buswidth > SPI_MEM_MAX_BUSWIDTH)
169 static int spi_mem_check_op(const struct spi_mem_op *op)
171 if (!op->cmd.buswidth)
174 if ((op->addr.nbytes && !op->addr.buswidth) ||
175 (op->dummy.nbytes && !op->dummy.buswidth) ||
176 (op->data.nbytes && !op->data.buswidth))
179 if (!spi_mem_buswidth_is_valid(op->cmd.buswidth) ||
180 !spi_mem_buswidth_is_valid(op->addr.buswidth) ||
181 !spi_mem_buswidth_is_valid(op->dummy.buswidth) ||
182 !spi_mem_buswidth_is_valid(op->data.buswidth))
188 static bool spi_mem_internal_supports_op(struct spi_mem *mem,
189 const struct spi_mem_op *op)
191 struct spi_controller *ctlr = mem->spi->controller;
193 if (ctlr->mem_ops && ctlr->mem_ops->supports_op)
194 return ctlr->mem_ops->supports_op(mem, op);
196 return spi_mem_default_supports_op(mem, op);
200 * spi_mem_supports_op() - Check if a memory device and the controller it is
201 * connected to support a specific memory operation
202 * @mem: the SPI memory
203 * @op: the memory operation to check
205 * Some controllers are only supporting Single or Dual IOs, others might only
206 * support specific opcodes, or it can even be that the controller and device
207 * both support Quad IOs but the hardware prevents you from using it because
208 * only 2 IO lines are connected.
210 * This function checks whether a specific operation is supported.
212 * Return: true if @op is supported, false otherwise.
214 bool spi_mem_supports_op(struct spi_mem *mem, const struct spi_mem_op *op)
216 if (spi_mem_check_op(op))
219 return spi_mem_internal_supports_op(mem, op);
221 EXPORT_SYMBOL_GPL(spi_mem_supports_op);
223 static int spi_mem_access_start(struct spi_mem *mem)
225 struct spi_controller *ctlr = mem->spi->controller;
228 * Flush the message queue before executing our SPI memory
229 * operation to prevent preemption of regular SPI transfers.
231 spi_flush_queue(ctlr);
233 if (ctlr->auto_runtime_pm) {
236 ret = pm_runtime_get_sync(ctlr->dev.parent);
238 dev_err(&ctlr->dev, "Failed to power device: %d\n",
244 mutex_lock(&ctlr->bus_lock_mutex);
245 mutex_lock(&ctlr->io_mutex);
250 static void spi_mem_access_end(struct spi_mem *mem)
252 struct spi_controller *ctlr = mem->spi->controller;
254 mutex_unlock(&ctlr->io_mutex);
255 mutex_unlock(&ctlr->bus_lock_mutex);
257 if (ctlr->auto_runtime_pm)
258 pm_runtime_put(ctlr->dev.parent);
262 * spi_mem_exec_op() - Execute a memory operation
263 * @mem: the SPI memory
264 * @op: the memory operation to execute
266 * Executes a memory operation.
268 * This function first checks that @op is supported and then tries to execute
271 * Return: 0 in case of success, a negative error code otherwise.
273 int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
275 unsigned int tmpbufsize, xferpos = 0, totalxferlen = 0;
276 struct spi_controller *ctlr = mem->spi->controller;
277 struct spi_transfer xfers[4] = { };
278 struct spi_message msg;
282 ret = spi_mem_check_op(op);
286 if (!spi_mem_internal_supports_op(mem, op))
290 ret = spi_mem_access_start(mem);
294 ret = ctlr->mem_ops->exec_op(mem, op);
296 spi_mem_access_end(mem);
299 * Some controllers only optimize specific paths (typically the
300 * read path) and expect the core to use the regular SPI
301 * interface in other cases.
303 if (!ret || ret != -ENOTSUPP)
307 tmpbufsize = sizeof(op->cmd.opcode) + op->addr.nbytes +
311 * Allocate a buffer to transmit the CMD, ADDR cycles with kmalloc() so
312 * we're guaranteed that this buffer is DMA-able, as required by the
315 tmpbuf = kzalloc(tmpbufsize, GFP_KERNEL | GFP_DMA);
319 spi_message_init(&msg);
321 tmpbuf[0] = op->cmd.opcode;
322 xfers[xferpos].tx_buf = tmpbuf;
323 xfers[xferpos].len = sizeof(op->cmd.opcode);
324 xfers[xferpos].tx_nbits = op->cmd.buswidth;
325 spi_message_add_tail(&xfers[xferpos], &msg);
329 if (op->addr.nbytes) {
332 for (i = 0; i < op->addr.nbytes; i++)
333 tmpbuf[i + 1] = op->addr.val >>
334 (8 * (op->addr.nbytes - i - 1));
336 xfers[xferpos].tx_buf = tmpbuf + 1;
337 xfers[xferpos].len = op->addr.nbytes;
338 xfers[xferpos].tx_nbits = op->addr.buswidth;
339 spi_message_add_tail(&xfers[xferpos], &msg);
341 totalxferlen += op->addr.nbytes;
344 if (op->dummy.nbytes) {
345 memset(tmpbuf + op->addr.nbytes + 1, 0xff, op->dummy.nbytes);
346 xfers[xferpos].tx_buf = tmpbuf + op->addr.nbytes + 1;
347 xfers[xferpos].len = op->dummy.nbytes;
348 xfers[xferpos].tx_nbits = op->dummy.buswidth;
349 spi_message_add_tail(&xfers[xferpos], &msg);
351 totalxferlen += op->dummy.nbytes;
354 if (op->data.nbytes) {
355 if (op->data.dir == SPI_MEM_DATA_IN) {
356 xfers[xferpos].rx_buf = op->data.buf.in;
357 xfers[xferpos].rx_nbits = op->data.buswidth;
359 xfers[xferpos].tx_buf = op->data.buf.out;
360 xfers[xferpos].tx_nbits = op->data.buswidth;
363 xfers[xferpos].len = op->data.nbytes;
364 spi_message_add_tail(&xfers[xferpos], &msg);
366 totalxferlen += op->data.nbytes;
369 ret = spi_sync(mem->spi, &msg);
376 if (msg.actual_length != totalxferlen)
381 EXPORT_SYMBOL_GPL(spi_mem_exec_op);
384 * spi_mem_get_name() - Return the SPI mem device name to be used by the
385 * upper layer if necessary
386 * @mem: the SPI memory
388 * This function allows SPI mem users to retrieve the SPI mem device name.
389 * It is useful if the upper layer needs to expose a custom name for
390 * compatibility reasons.
392 * Return: a string containing the name of the memory device to be used
393 * by the SPI mem user
395 const char *spi_mem_get_name(struct spi_mem *mem)
399 EXPORT_SYMBOL_GPL(spi_mem_get_name);
402 * spi_mem_adjust_op_size() - Adjust the data size of a SPI mem operation to
403 * match controller limitations
404 * @mem: the SPI memory
405 * @op: the operation to adjust
407 * Some controllers have FIFO limitations and must split a data transfer
408 * operation into multiple ones, others require a specific alignment for
409 * optimized accesses. This function allows SPI mem drivers to split a single
410 * operation into multiple sub-operations when required.
412 * Return: a negative error code if the controller can't properly adjust @op,
413 * 0 otherwise. Note that @op->data.nbytes will be updated if @op
414 * can't be handled in a single step.
416 int spi_mem_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
418 struct spi_controller *ctlr = mem->spi->controller;
421 len = sizeof(op->cmd.opcode) + op->addr.nbytes + op->dummy.nbytes;
423 if (ctlr->mem_ops && ctlr->mem_ops->adjust_op_size)
424 return ctlr->mem_ops->adjust_op_size(mem, op);
426 if (!ctlr->mem_ops || !ctlr->mem_ops->exec_op) {
427 if (len > spi_max_transfer_size(mem->spi))
430 op->data.nbytes = min3((size_t)op->data.nbytes,
431 spi_max_transfer_size(mem->spi),
432 spi_max_message_size(mem->spi) -
434 if (!op->data.nbytes)
440 EXPORT_SYMBOL_GPL(spi_mem_adjust_op_size);
442 static ssize_t spi_mem_no_dirmap_read(struct spi_mem_dirmap_desc *desc,
443 u64 offs, size_t len, void *buf)
445 struct spi_mem_op op = desc->info.op_tmpl;
448 op.addr.val = desc->info.offset + offs;
449 op.data.buf.in = buf;
450 op.data.nbytes = len;
451 ret = spi_mem_adjust_op_size(desc->mem, &op);
455 ret = spi_mem_exec_op(desc->mem, &op);
459 return op.data.nbytes;
462 static ssize_t spi_mem_no_dirmap_write(struct spi_mem_dirmap_desc *desc,
463 u64 offs, size_t len, const void *buf)
465 struct spi_mem_op op = desc->info.op_tmpl;
468 op.addr.val = desc->info.offset + offs;
469 op.data.buf.out = buf;
470 op.data.nbytes = len;
471 ret = spi_mem_adjust_op_size(desc->mem, &op);
475 ret = spi_mem_exec_op(desc->mem, &op);
479 return op.data.nbytes;
483 * spi_mem_dirmap_create() - Create a direct mapping descriptor
484 * @mem: SPI mem device this direct mapping should be created for
485 * @info: direct mapping information
487 * This function is creating a direct mapping descriptor which can then be used
488 * to access the memory using spi_mem_dirmap_read() or spi_mem_dirmap_write().
489 * If the SPI controller driver does not support direct mapping, this function
490 * fallback to an implementation using spi_mem_exec_op(), so that the caller
491 * doesn't have to bother implementing a fallback on his own.
493 * Return: a valid pointer in case of success, and ERR_PTR() otherwise.
495 struct spi_mem_dirmap_desc *
496 spi_mem_dirmap_create(struct spi_mem *mem,
497 const struct spi_mem_dirmap_info *info)
499 struct spi_controller *ctlr = mem->spi->controller;
500 struct spi_mem_dirmap_desc *desc;
503 /* Make sure the number of address cycles is between 1 and 8 bytes. */
504 if (!info->op_tmpl.addr.nbytes || info->op_tmpl.addr.nbytes > 8)
505 return ERR_PTR(-EINVAL);
507 /* data.dir should either be SPI_MEM_DATA_IN or SPI_MEM_DATA_OUT. */
508 if (info->op_tmpl.data.dir == SPI_MEM_NO_DATA)
509 return ERR_PTR(-EINVAL);
511 desc = kzalloc(sizeof(*desc), GFP_KERNEL);
513 return ERR_PTR(-ENOMEM);
517 if (ctlr->mem_ops && ctlr->mem_ops->dirmap_create)
518 ret = ctlr->mem_ops->dirmap_create(desc);
521 desc->nodirmap = true;
522 if (!spi_mem_supports_op(desc->mem, &desc->info.op_tmpl))
535 EXPORT_SYMBOL_GPL(spi_mem_dirmap_create);
538 * spi_mem_dirmap_destroy() - Destroy a direct mapping descriptor
539 * @desc: the direct mapping descriptor to destroy
540 * @info: direct mapping information
542 * This function destroys a direct mapping descriptor previously created by
543 * spi_mem_dirmap_create().
545 void spi_mem_dirmap_destroy(struct spi_mem_dirmap_desc *desc)
547 struct spi_controller *ctlr = desc->mem->spi->controller;
549 if (!desc->nodirmap && ctlr->mem_ops && ctlr->mem_ops->dirmap_destroy)
550 ctlr->mem_ops->dirmap_destroy(desc);
552 EXPORT_SYMBOL_GPL(spi_mem_dirmap_destroy);
554 static void devm_spi_mem_dirmap_release(struct device *dev, void *res)
556 struct spi_mem_dirmap_desc *desc = *(struct spi_mem_dirmap_desc **)res;
558 spi_mem_dirmap_destroy(desc);
562 * devm_spi_mem_dirmap_create() - Create a direct mapping descriptor and attach
564 * @dev: device the dirmap desc will be attached to
565 * @mem: SPI mem device this direct mapping should be created for
566 * @info: direct mapping information
568 * devm_ variant of the spi_mem_dirmap_create() function. See
569 * spi_mem_dirmap_create() for more details.
571 * Return: a valid pointer in case of success, and ERR_PTR() otherwise.
573 struct spi_mem_dirmap_desc *
574 devm_spi_mem_dirmap_create(struct device *dev, struct spi_mem *mem,
575 const struct spi_mem_dirmap_info *info)
577 struct spi_mem_dirmap_desc **ptr, *desc;
579 ptr = devres_alloc(devm_spi_mem_dirmap_release, sizeof(*ptr),
582 return ERR_PTR(-ENOMEM);
584 desc = spi_mem_dirmap_create(mem, info);
589 devres_add(dev, ptr);
594 EXPORT_SYMBOL_GPL(devm_spi_mem_dirmap_create);
596 static int devm_spi_mem_dirmap_match(struct device *dev, void *res, void *data)
598 struct spi_mem_dirmap_desc **ptr = res;
600 if (WARN_ON(!ptr || !*ptr))
607 * devm_spi_mem_dirmap_destroy() - Destroy a direct mapping descriptor attached
609 * @dev: device the dirmap desc is attached to
610 * @desc: the direct mapping descriptor to destroy
612 * devm_ variant of the spi_mem_dirmap_destroy() function. See
613 * spi_mem_dirmap_destroy() for more details.
615 void devm_spi_mem_dirmap_destroy(struct device *dev,
616 struct spi_mem_dirmap_desc *desc)
618 devres_release(dev, devm_spi_mem_dirmap_release,
619 devm_spi_mem_dirmap_match, desc);
621 EXPORT_SYMBOL_GPL(devm_spi_mem_dirmap_destroy);
624 * spi_mem_dirmap_dirmap_read() - Read data through a direct mapping
625 * @desc: direct mapping descriptor
626 * @offs: offset to start reading from. Note that this is not an absolute
627 * offset, but the offset within the direct mapping which already has
629 * @len: length in bytes
630 * @buf: destination buffer. This buffer must be DMA-able
632 * This function reads data from a memory device using a direct mapping
633 * previously instantiated with spi_mem_dirmap_create().
635 * Return: the amount of data read from the memory device or a negative error
636 * code. Note that the returned size might be smaller than @len, and the caller
637 * is responsible for calling spi_mem_dirmap_read() again when that happens.
639 ssize_t spi_mem_dirmap_read(struct spi_mem_dirmap_desc *desc,
640 u64 offs, size_t len, void *buf)
642 struct spi_controller *ctlr = desc->mem->spi->controller;
645 if (desc->info.op_tmpl.data.dir != SPI_MEM_DATA_IN)
651 if (desc->nodirmap) {
652 ret = spi_mem_no_dirmap_read(desc, offs, len, buf);
653 } else if (ctlr->mem_ops && ctlr->mem_ops->dirmap_read) {
654 ret = spi_mem_access_start(desc->mem);
658 ret = ctlr->mem_ops->dirmap_read(desc, offs, len, buf);
660 spi_mem_access_end(desc->mem);
667 EXPORT_SYMBOL_GPL(spi_mem_dirmap_read);
670 * spi_mem_dirmap_dirmap_write() - Write data through a direct mapping
671 * @desc: direct mapping descriptor
672 * @offs: offset to start writing from. Note that this is not an absolute
673 * offset, but the offset within the direct mapping which already has
675 * @len: length in bytes
676 * @buf: source buffer. This buffer must be DMA-able
678 * This function writes data to a memory device using a direct mapping
679 * previously instantiated with spi_mem_dirmap_create().
681 * Return: the amount of data written to the memory device or a negative error
682 * code. Note that the returned size might be smaller than @len, and the caller
683 * is responsible for calling spi_mem_dirmap_write() again when that happens.
685 ssize_t spi_mem_dirmap_write(struct spi_mem_dirmap_desc *desc,
686 u64 offs, size_t len, const void *buf)
688 struct spi_controller *ctlr = desc->mem->spi->controller;
691 if (desc->info.op_tmpl.data.dir != SPI_MEM_DATA_OUT)
697 if (desc->nodirmap) {
698 ret = spi_mem_no_dirmap_write(desc, offs, len, buf);
699 } else if (ctlr->mem_ops && ctlr->mem_ops->dirmap_write) {
700 ret = spi_mem_access_start(desc->mem);
704 ret = ctlr->mem_ops->dirmap_write(desc, offs, len, buf);
706 spi_mem_access_end(desc->mem);
713 EXPORT_SYMBOL_GPL(spi_mem_dirmap_write);
715 static inline struct spi_mem_driver *to_spi_mem_drv(struct device_driver *drv)
717 return container_of(drv, struct spi_mem_driver, spidrv.driver);
720 static int spi_mem_probe(struct spi_device *spi)
722 struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
723 struct spi_controller *ctlr = spi->controller;
726 mem = devm_kzalloc(&spi->dev, sizeof(*mem), GFP_KERNEL);
732 if (ctlr->mem_ops && ctlr->mem_ops->get_name)
733 mem->name = ctlr->mem_ops->get_name(mem);
735 mem->name = dev_name(&spi->dev);
737 if (IS_ERR_OR_NULL(mem->name))
738 return PTR_ERR(mem->name);
740 spi_set_drvdata(spi, mem);
742 return memdrv->probe(mem);
745 static int spi_mem_remove(struct spi_device *spi)
747 struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
748 struct spi_mem *mem = spi_get_drvdata(spi);
751 return memdrv->remove(mem);
756 static void spi_mem_shutdown(struct spi_device *spi)
758 struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
759 struct spi_mem *mem = spi_get_drvdata(spi);
761 if (memdrv->shutdown)
762 memdrv->shutdown(mem);
766 * spi_mem_driver_register_with_owner() - Register a SPI memory driver
767 * @memdrv: the SPI memory driver to register
768 * @owner: the owner of this driver
770 * Registers a SPI memory driver.
772 * Return: 0 in case of success, a negative error core otherwise.
775 int spi_mem_driver_register_with_owner(struct spi_mem_driver *memdrv,
776 struct module *owner)
778 memdrv->spidrv.probe = spi_mem_probe;
779 memdrv->spidrv.remove = spi_mem_remove;
780 memdrv->spidrv.shutdown = spi_mem_shutdown;
782 return __spi_register_driver(owner, &memdrv->spidrv);
784 EXPORT_SYMBOL_GPL(spi_mem_driver_register_with_owner);
787 * spi_mem_driver_unregister_with_owner() - Unregister a SPI memory driver
788 * @memdrv: the SPI memory driver to unregister
790 * Unregisters a SPI memory driver.
792 void spi_mem_driver_unregister(struct spi_mem_driver *memdrv)
794 spi_unregister_driver(&memdrv->spidrv);
796 EXPORT_SYMBOL_GPL(spi_mem_driver_unregister);