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>
10 #include <linux/dmaengine.h>
11 #include <linux/pm_runtime.h>
12 #include "internals.h"
20 * spi_controller_dma_map_mem_op_data() - DMA-map the buffer attached to a
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
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.
34 * Return: 0 in case of success, a negative error code otherwise.
36 int spi_controller_dma_map_mem_op_data(struct spi_controller *ctlr,
37 const struct spi_mem_op *op,
40 struct device *dmadev;
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;
50 dmadev = ctlr->dev.parent;
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);
59 EXPORT_SYMBOL_GPL(spi_controller_dma_map_mem_op_data);
62 * spi_controller_dma_unmap_mem_op_data() - DMA-unmap the buffer attached to a
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()
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.
73 * This function is not intended to be called from SPI drivers. Only SPI
74 * controller drivers should use it.
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
80 * Return: 0 in case of success, a negative error code otherwise.
82 void spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr,
83 const struct spi_mem_op *op,
86 struct device *dmadev;
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;
96 dmadev = ctlr->dev.parent;
98 spi_unmap_buf(ctlr, dmadev, sgt,
99 op->data.dir == SPI_MEM_DATA_IN ?
100 DMA_FROM_DEVICE : DMA_TO_DEVICE);
102 EXPORT_SYMBOL_GPL(spi_controller_dma_unmap_mem_op_data);
103 #endif /* __UBOOT__ */
105 static int spi_check_buswidth_req(struct spi_slave *slave, u8 buswidth, bool tx)
107 u32 mode = slave->mode;
114 if ((tx && (mode & (SPI_TX_DUAL | SPI_TX_QUAD))) ||
115 (!tx && (mode & (SPI_RX_DUAL | SPI_RX_QUAD))))
121 if ((tx && (mode & SPI_TX_QUAD)) ||
122 (!tx && (mode & SPI_RX_QUAD)))
134 bool spi_mem_default_supports_op(struct spi_slave *slave,
135 const struct spi_mem_op *op)
137 if (spi_check_buswidth_req(slave, op->cmd.buswidth, true))
140 if (op->addr.nbytes &&
141 spi_check_buswidth_req(slave, op->addr.buswidth, true))
144 if (op->dummy.nbytes &&
145 spi_check_buswidth_req(slave, op->dummy.buswidth, true))
148 if (op->data.nbytes &&
149 spi_check_buswidth_req(slave, op->data.buswidth,
150 op->data.dir == SPI_MEM_DATA_OUT))
155 EXPORT_SYMBOL_GPL(spi_mem_default_supports_op);
158 * spi_mem_supports_op() - Check if a memory device and the controller it is
159 * connected to support a specific memory operation
160 * @slave: the SPI device
161 * @op: the memory operation to check
163 * Some controllers are only supporting Single or Dual IOs, others might only
164 * support specific opcodes, or it can even be that the controller and device
165 * both support Quad IOs but the hardware prevents you from using it because
166 * only 2 IO lines are connected.
168 * This function checks whether a specific operation is supported.
170 * Return: true if @op is supported, false otherwise.
172 bool spi_mem_supports_op(struct spi_slave *slave,
173 const struct spi_mem_op *op)
175 struct udevice *bus = slave->dev->parent;
176 struct dm_spi_ops *ops = spi_get_ops(bus);
178 if (ops->mem_ops && ops->mem_ops->supports_op)
179 return ops->mem_ops->supports_op(slave, op);
181 return spi_mem_default_supports_op(slave, op);
183 EXPORT_SYMBOL_GPL(spi_mem_supports_op);
186 * spi_mem_exec_op() - Execute a memory operation
187 * @slave: the SPI device
188 * @op: the memory operation to execute
190 * Executes a memory operation.
192 * This function first checks that @op is supported and then tries to execute
195 * Return: 0 in case of success, a negative error code otherwise.
197 int spi_mem_exec_op(struct spi_slave *slave, const struct spi_mem_op *op)
199 struct udevice *bus = slave->dev->parent;
200 struct dm_spi_ops *ops = spi_get_ops(bus);
201 unsigned int pos = 0;
202 const u8 *tx_buf = NULL;
210 if (!spi_mem_supports_op(slave, op))
213 ret = spi_claim_bus(slave);
217 if (ops->mem_ops && ops->mem_ops->exec_op) {
220 * Flush the message queue before executing our SPI memory
221 * operation to prevent preemption of regular SPI transfers.
223 spi_flush_queue(ctlr);
225 if (ctlr->auto_runtime_pm) {
226 ret = pm_runtime_get_sync(ctlr->dev.parent);
229 "Failed to power device: %d\n",
235 mutex_lock(&ctlr->bus_lock_mutex);
236 mutex_lock(&ctlr->io_mutex);
238 ret = ops->mem_ops->exec_op(slave, op);
241 mutex_unlock(&ctlr->io_mutex);
242 mutex_unlock(&ctlr->bus_lock_mutex);
244 if (ctlr->auto_runtime_pm)
245 pm_runtime_put(ctlr->dev.parent);
249 * Some controllers only optimize specific paths (typically the
250 * read path) and expect the core to use the regular SPI
251 * interface in other cases.
253 if (!ret || ret != -ENOTSUPP) {
254 spi_release_bus(slave);
260 tmpbufsize = sizeof(op->cmd.opcode) + op->addr.nbytes +
264 * Allocate a buffer to transmit the CMD, ADDR cycles with kmalloc() so
265 * we're guaranteed that this buffer is DMA-able, as required by the
268 tmpbuf = kzalloc(tmpbufsize, GFP_KERNEL | GFP_DMA);
272 spi_message_init(&msg);
274 tmpbuf[0] = op->cmd.opcode;
275 xfers[xferpos].tx_buf = tmpbuf;
276 xfers[xferpos].len = sizeof(op->cmd.opcode);
277 xfers[xferpos].tx_nbits = op->cmd.buswidth;
278 spi_message_add_tail(&xfers[xferpos], &msg);
282 if (op->addr.nbytes) {
285 for (i = 0; i < op->addr.nbytes; i++)
286 tmpbuf[i + 1] = op->addr.val >>
287 (8 * (op->addr.nbytes - i - 1));
289 xfers[xferpos].tx_buf = tmpbuf + 1;
290 xfers[xferpos].len = op->addr.nbytes;
291 xfers[xferpos].tx_nbits = op->addr.buswidth;
292 spi_message_add_tail(&xfers[xferpos], &msg);
294 totalxferlen += op->addr.nbytes;
297 if (op->dummy.nbytes) {
298 memset(tmpbuf + op->addr.nbytes + 1, 0xff, op->dummy.nbytes);
299 xfers[xferpos].tx_buf = tmpbuf + op->addr.nbytes + 1;
300 xfers[xferpos].len = op->dummy.nbytes;
301 xfers[xferpos].tx_nbits = op->dummy.buswidth;
302 spi_message_add_tail(&xfers[xferpos], &msg);
304 totalxferlen += op->dummy.nbytes;
307 if (op->data.nbytes) {
308 if (op->data.dir == SPI_MEM_DATA_IN) {
309 xfers[xferpos].rx_buf = op->data.buf.in;
310 xfers[xferpos].rx_nbits = op->data.buswidth;
312 xfers[xferpos].tx_buf = op->data.buf.out;
313 xfers[xferpos].tx_nbits = op->data.buswidth;
316 xfers[xferpos].len = op->data.nbytes;
317 spi_message_add_tail(&xfers[xferpos], &msg);
319 totalxferlen += op->data.nbytes;
322 ret = spi_sync(slave, &msg);
329 if (msg.actual_length != totalxferlen)
333 if (op->data.nbytes) {
334 if (op->data.dir == SPI_MEM_DATA_IN)
335 rx_buf = op->data.buf.in;
337 tx_buf = op->data.buf.out;
340 op_len = sizeof(op->cmd.opcode) + op->addr.nbytes + op->dummy.nbytes;
341 op_buf = calloc(1, op_len);
343 op_buf[pos++] = op->cmd.opcode;
345 if (op->addr.nbytes) {
346 for (i = 0; i < op->addr.nbytes; i++)
347 op_buf[pos + i] = op->addr.val >>
348 (8 * (op->addr.nbytes - i - 1));
350 pos += op->addr.nbytes;
353 if (op->dummy.nbytes)
354 memset(op_buf + pos, 0xff, op->dummy.nbytes);
356 /* 1st transfer: opcode + address + dummy cycles */
357 flag = SPI_XFER_BEGIN;
358 /* Make sure to set END bit if no tx or rx data messages follow */
359 if (!tx_buf && !rx_buf)
360 flag |= SPI_XFER_END;
362 ret = spi_xfer(slave, op_len * 8, op_buf, NULL, flag);
366 /* 2nd transfer: rx or tx data path */
367 if (tx_buf || rx_buf) {
368 ret = spi_xfer(slave, op->data.nbytes * 8, tx_buf,
369 rx_buf, SPI_XFER_END);
374 spi_release_bus(slave);
376 for (i = 0; i < pos; i++)
377 debug("%02x ", op_buf[i]);
379 tx_buf || rx_buf ? op->data.nbytes : 0,
380 tx_buf || rx_buf ? (tx_buf ? "out" : "in") : "-");
381 for (i = 0; i < op->data.nbytes; i++)
382 debug("%02x ", tx_buf ? tx_buf[i] : rx_buf[i]);
383 debug("[ret %d]\n", ret);
389 #endif /* __UBOOT__ */
393 EXPORT_SYMBOL_GPL(spi_mem_exec_op);
396 * spi_mem_adjust_op_size() - Adjust the data size of a SPI mem operation to
397 * match controller limitations
398 * @slave: the SPI device
399 * @op: the operation to adjust
401 * Some controllers have FIFO limitations and must split a data transfer
402 * operation into multiple ones, others require a specific alignment for
403 * optimized accesses. This function allows SPI mem drivers to split a single
404 * operation into multiple sub-operations when required.
406 * Return: a negative error code if the controller can't properly adjust @op,
407 * 0 otherwise. Note that @op->data.nbytes will be updated if @op
408 * can't be handled in a single step.
410 int spi_mem_adjust_op_size(struct spi_slave *slave, struct spi_mem_op *op)
412 struct udevice *bus = slave->dev->parent;
413 struct dm_spi_ops *ops = spi_get_ops(bus);
415 if (ops->mem_ops && ops->mem_ops->adjust_op_size)
416 return ops->mem_ops->adjust_op_size(slave, op);
418 if (!ops->mem_ops || !ops->mem_ops->exec_op) {
421 len = sizeof(op->cmd.opcode) + op->addr.nbytes +
423 if (slave->max_write_size && len > slave->max_write_size)
426 if (op->data.dir == SPI_MEM_DATA_IN && slave->max_read_size)
427 op->data.nbytes = min(op->data.nbytes,
428 slave->max_read_size);
429 else if (slave->max_write_size)
430 op->data.nbytes = min(op->data.nbytes,
431 slave->max_write_size - len);
433 if (!op->data.nbytes)
439 EXPORT_SYMBOL_GPL(spi_mem_adjust_op_size);
442 static inline struct spi_mem_driver *to_spi_mem_drv(struct device_driver *drv)
444 return container_of(drv, struct spi_mem_driver, spidrv.driver);
447 static int spi_mem_probe(struct spi_device *spi)
449 struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
452 mem = devm_kzalloc(&spi->dev, sizeof(*mem), GFP_KERNEL);
457 spi_set_drvdata(spi, mem);
459 return memdrv->probe(mem);
462 static int spi_mem_remove(struct spi_device *spi)
464 struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
465 struct spi_mem *mem = spi_get_drvdata(spi);
468 return memdrv->remove(mem);
473 static void spi_mem_shutdown(struct spi_device *spi)
475 struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
476 struct spi_mem *mem = spi_get_drvdata(spi);
478 if (memdrv->shutdown)
479 memdrv->shutdown(mem);
483 * spi_mem_driver_register_with_owner() - Register a SPI memory driver
484 * @memdrv: the SPI memory driver to register
485 * @owner: the owner of this driver
487 * Registers a SPI memory driver.
489 * Return: 0 in case of success, a negative error core otherwise.
492 int spi_mem_driver_register_with_owner(struct spi_mem_driver *memdrv,
493 struct module *owner)
495 memdrv->spidrv.probe = spi_mem_probe;
496 memdrv->spidrv.remove = spi_mem_remove;
497 memdrv->spidrv.shutdown = spi_mem_shutdown;
499 return __spi_register_driver(owner, &memdrv->spidrv);
501 EXPORT_SYMBOL_GPL(spi_mem_driver_register_with_owner);
504 * spi_mem_driver_unregister_with_owner() - Unregister a SPI memory driver
505 * @memdrv: the SPI memory driver to unregister
507 * Unregisters a SPI memory driver.
509 void spi_mem_driver_unregister(struct spi_mem_driver *memdrv)
511 spi_unregister_driver(&memdrv->spidrv);
513 EXPORT_SYMBOL_GPL(spi_mem_driver_unregister);
514 #endif /* __UBOOT__ */