summaryrefslogtreecommitdiff
path: root/drivers/spi/spi-mem.c
blob: d344701aebb93fe319dd06c1676ea4bab281f633 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2018 Exceet Electronics GmbH
 * Copyright (C) 2018 Bootlin
 *
 * Author: Boris Brezillon <boris.brezillon@bootlin.com>
 */

#ifndef __UBOOT__
#include <log.h>
#include <dm/devres.h>
#include <linux/dmaengine.h>
#include <linux/pm_runtime.h>
#include "internals.h"
#else
#include <dm/device_compat.h>
#include <spi.h>
#include <spi-mem.h>
#endif

#ifndef __UBOOT__
/**
 * spi_controller_dma_map_mem_op_data() - DMA-map the buffer attached to a
 *					  memory operation
 * @ctlr: the SPI controller requesting this dma_map()
 * @op: the memory operation containing the buffer to map
 * @sgt: a pointer to a non-initialized sg_table that will be filled by this
 *	 function
 *
 * Some controllers might want to do DMA on the data buffer embedded in @op.
 * This helper prepares everything for you and provides a ready-to-use
 * sg_table. This function is not intended to be called from spi drivers.
 * Only SPI controller drivers should use it.
 * Note that the caller must ensure the memory region pointed by
 * op->data.buf.{in,out} is DMA-able before calling this function.
 *
 * Return: 0 in case of success, a negative error code otherwise.
 */
int spi_controller_dma_map_mem_op_data(struct spi_controller *ctlr,
				       const struct spi_mem_op *op,
				       struct sg_table *sgt)
{
	struct device *dmadev;

	if (!op->data.nbytes)
		return -EINVAL;

	if (op->data.dir == SPI_MEM_DATA_OUT && ctlr->dma_tx)
		dmadev = ctlr->dma_tx->device->dev;
	else if (op->data.dir == SPI_MEM_DATA_IN && ctlr->dma_rx)
		dmadev = ctlr->dma_rx->device->dev;
	else
		dmadev = ctlr->dev.parent;

	if (!dmadev)
		return -EINVAL;

	return spi_map_buf(ctlr, dmadev, sgt, op->data.buf.in, op->data.nbytes,
			   op->data.dir == SPI_MEM_DATA_IN ?
			   DMA_FROM_DEVICE : DMA_TO_DEVICE);
}
EXPORT_SYMBOL_GPL(spi_controller_dma_map_mem_op_data);

/**
 * spi_controller_dma_unmap_mem_op_data() - DMA-unmap the buffer attached to a
 *					    memory operation
 * @ctlr: the SPI controller requesting this dma_unmap()
 * @op: the memory operation containing the buffer to unmap
 * @sgt: a pointer to an sg_table previously initialized by
 *	 spi_controller_dma_map_mem_op_data()
 *
 * Some controllers might want to do DMA on the data buffer embedded in @op.
 * This helper prepares things so that the CPU can access the
 * op->data.buf.{in,out} buffer again.
 *
 * This function is not intended to be called from SPI drivers. Only SPI
 * controller drivers should use it.
 *
 * This function should be called after the DMA operation has finished and is
 * only valid if the previous spi_controller_dma_map_mem_op_data() call
 * returned 0.
 *
 * Return: 0 in case of success, a negative error code otherwise.
 */
void spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr,
					  const struct spi_mem_op *op,
					  struct sg_table *sgt)
{
	struct device *dmadev;

	if (!op->data.nbytes)
		return;

	if (op->data.dir == SPI_MEM_DATA_OUT && ctlr->dma_tx)
		dmadev = ctlr->dma_tx->device->dev;
	else if (op->data.dir == SPI_MEM_DATA_IN && ctlr->dma_rx)
		dmadev = ctlr->dma_rx->device->dev;
	else
		dmadev = ctlr->dev.parent;

	spi_unmap_buf(ctlr, dmadev, sgt,
		      op->data.dir == SPI_MEM_DATA_IN ?
		      DMA_FROM_DEVICE : DMA_TO_DEVICE);
}
EXPORT_SYMBOL_GPL(spi_controller_dma_unmap_mem_op_data);
#endif /* __UBOOT__ */

static int spi_check_buswidth_req(struct spi_slave *slave, u8 buswidth, bool tx)
{
	u32 mode = slave->mode;

	switch (buswidth) {
	case 1:
		return 0;

	case 2:
		if ((tx && (mode & (SPI_TX_DUAL | SPI_TX_QUAD))) ||
		    (!tx && (mode & (SPI_RX_DUAL | SPI_RX_QUAD))))
			return 0;

		break;

	case 4:
		if ((tx && (mode & SPI_TX_QUAD)) ||
		    (!tx && (mode & SPI_RX_QUAD)))
			return 0;

		break;
	case 8:
		if ((tx && (mode & SPI_TX_OCTAL)) ||
		    (!tx && (mode & SPI_RX_OCTAL)))
			return 0;

		break;

	default:
		break;
	}

	return -ENOTSUPP;
}

bool spi_mem_default_supports_op(struct spi_slave *slave,
				 const struct spi_mem_op *op)
{
	if (spi_check_buswidth_req(slave, op->cmd.buswidth, true))
		return false;

	if (op->addr.nbytes &&
	    spi_check_buswidth_req(slave, op->addr.buswidth, true))
		return false;

	if (op->dummy.nbytes &&
	    spi_check_buswidth_req(slave, op->dummy.buswidth, true))
		return false;

	if (op->data.dir != SPI_MEM_NO_DATA &&
	    spi_check_buswidth_req(slave, op->data.buswidth,
				   op->data.dir == SPI_MEM_DATA_OUT))
		return false;

	return true;
}
EXPORT_SYMBOL_GPL(spi_mem_default_supports_op);

/**
 * spi_mem_supports_op() - Check if a memory device and the controller it is
 *			   connected to support a specific memory operation
 * @slave: the SPI device
 * @op: the memory operation to check
 *
 * Some controllers are only supporting Single or Dual IOs, others might only
 * support specific opcodes, or it can even be that the controller and device
 * both support Quad IOs but the hardware prevents you from using it because
 * only 2 IO lines are connected.
 *
 * This function checks whether a specific operation is supported.
 *
 * Return: true if @op is supported, false otherwise.
 */
bool spi_mem_supports_op(struct spi_slave *slave,
			 const struct spi_mem_op *op)
{
	struct udevice *bus = slave->dev->parent;
	struct dm_spi_ops *ops = spi_get_ops(bus);

	if (ops->mem_ops && ops->mem_ops->supports_op)
		return ops->mem_ops->supports_op(slave, op);

	return spi_mem_default_supports_op(slave, op);
}
EXPORT_SYMBOL_GPL(spi_mem_supports_op);

/**
 * spi_mem_exec_op() - Execute a memory operation
 * @slave: the SPI device
 * @op: the memory operation to execute
 *
 * Executes a memory operation.
 *
 * This function first checks that @op is supported and then tries to execute
 * it.
 *
 * Return: 0 in case of success, a negative error code otherwise.
 */
int spi_mem_exec_op(struct spi_slave *slave, const struct spi_mem_op *op)
{
	struct udevice *bus = slave->dev->parent;
	struct dm_spi_ops *ops = spi_get_ops(bus);
	unsigned int pos = 0;
	const u8 *tx_buf = NULL;
	u8 *rx_buf = NULL;
	int op_len;
	u32 flag;
	int ret;
	int i;

	if (!spi_mem_supports_op(slave, op))
		return -ENOTSUPP;

	ret = spi_claim_bus(slave);
	if (ret < 0)
		return ret;

	if (ops->mem_ops && ops->mem_ops->exec_op) {
#ifndef __UBOOT__
		/*
		 * Flush the message queue before executing our SPI memory
		 * operation to prevent preemption of regular SPI transfers.
		 */
		spi_flush_queue(ctlr);

		if (ctlr->auto_runtime_pm) {
			ret = pm_runtime_get_sync(ctlr->dev.parent);
			if (ret < 0) {
				dev_err(&ctlr->dev,
					"Failed to power device: %d\n",
					ret);
				return ret;
			}
		}

		mutex_lock(&ctlr->bus_lock_mutex);
		mutex_lock(&ctlr->io_mutex);
#endif
		ret = ops->mem_ops->exec_op(slave, op);

#ifndef __UBOOT__
		mutex_unlock(&ctlr->io_mutex);
		mutex_unlock(&ctlr->bus_lock_mutex);

		if (ctlr->auto_runtime_pm)
			pm_runtime_put(ctlr->dev.parent);
#endif

		/*
		 * Some controllers only optimize specific paths (typically the
		 * read path) and expect the core to use the regular SPI
		 * interface in other cases.
		 */
		if (!ret || ret != -ENOTSUPP) {
			spi_release_bus(slave);
			return ret;
		}
	}

#ifndef __UBOOT__
	tmpbufsize = sizeof(op->cmd.opcode) + op->addr.nbytes +
		     op->dummy.nbytes;

	/*
	 * Allocate a buffer to transmit the CMD, ADDR cycles with kmalloc() so
	 * we're guaranteed that this buffer is DMA-able, as required by the
	 * SPI layer.
	 */
	tmpbuf = kzalloc(tmpbufsize, GFP_KERNEL | GFP_DMA);
	if (!tmpbuf)
		return -ENOMEM;

	spi_message_init(&msg);

	tmpbuf[0] = op->cmd.opcode;
	xfers[xferpos].tx_buf = tmpbuf;
	xfers[xferpos].len = sizeof(op->cmd.opcode);
	xfers[xferpos].tx_nbits = op->cmd.buswidth;
	spi_message_add_tail(&xfers[xferpos], &msg);
	xferpos++;
	totalxferlen++;

	if (op->addr.nbytes) {
		int i;

		for (i = 0; i < op->addr.nbytes; i++)
			tmpbuf[i + 1] = op->addr.val >>
					(8 * (op->addr.nbytes - i - 1));

		xfers[xferpos].tx_buf = tmpbuf + 1;
		xfers[xferpos].len = op->addr.nbytes;
		xfers[xferpos].tx_nbits = op->addr.buswidth;
		spi_message_add_tail(&xfers[xferpos], &msg);
		xferpos++;
		totalxferlen += op->addr.nbytes;
	}

	if (op->dummy.nbytes) {
		memset(tmpbuf + op->addr.nbytes + 1, 0xff, op->dummy.nbytes);
		xfers[xferpos].tx_buf = tmpbuf + op->addr.nbytes + 1;
		xfers[xferpos].len = op->dummy.nbytes;
		xfers[xferpos].tx_nbits = op->dummy.buswidth;
		spi_message_add_tail(&xfers[xferpos], &msg);
		xferpos++;
		totalxferlen += op->dummy.nbytes;
	}

	if (op->data.nbytes) {
		if (op->data.dir == SPI_MEM_DATA_IN) {
			xfers[xferpos].rx_buf = op->data.buf.in;
			xfers[xferpos].rx_nbits = op->data.buswidth;
		} else {
			xfers[xferpos].tx_buf = op->data.buf.out;
			xfers[xferpos].tx_nbits = op->data.buswidth;
		}

		xfers[xferpos].len = op->data.nbytes;
		spi_message_add_tail(&xfers[xferpos], &msg);
		xferpos++;
		totalxferlen += op->data.nbytes;
	}

	ret = spi_sync(slave, &msg);

	kfree(tmpbuf);

	if (ret)
		return ret;

	if (msg.actual_length != totalxferlen)
		return -EIO;
#else

	if (op->data.nbytes) {
		if (op->data.dir == SPI_MEM_DATA_IN)
			rx_buf = op->data.buf.in;
		else
			tx_buf = op->data.buf.out;
	}

	op_len = sizeof(op->cmd.opcode) + op->addr.nbytes + op->dummy.nbytes;

	/*
	 * Avoid using malloc() here so that we can use this code in SPL where
	 * simple malloc may be used. That implementation does not allow free()
	 * so repeated calls to this code can exhaust the space.
	 *
	 * The value of op_len is small, since it does not include the actual
	 * data being sent, only the op-code and address. In fact, it should be
	 * possible to just use a small fixed value here instead of op_len.
	 */
	u8 op_buf[op_len];

	op_buf[pos++] = op->cmd.opcode;

	if (op->addr.nbytes) {
		for (i = 0; i < op->addr.nbytes; i++)
			op_buf[pos + i] = op->addr.val >>
				(8 * (op->addr.nbytes - i - 1));

		pos += op->addr.nbytes;
	}

	if (op->dummy.nbytes)
		memset(op_buf + pos, 0xff, op->dummy.nbytes);

	/* 1st transfer: opcode + address + dummy cycles */
	flag = SPI_XFER_BEGIN;
	/* Make sure to set END bit if no tx or rx data messages follow */
	if (!tx_buf && !rx_buf)
		flag |= SPI_XFER_END;

	ret = spi_xfer(slave, op_len * 8, op_buf, NULL, flag);
	if (ret)
		return ret;

	/* 2nd transfer: rx or tx data path */
	if (tx_buf || rx_buf) {
		ret = spi_xfer(slave, op->data.nbytes * 8, tx_buf,
			       rx_buf, SPI_XFER_END);
		if (ret)
			return ret;
	}

	spi_release_bus(slave);

	for (i = 0; i < pos; i++)
		debug("%02x ", op_buf[i]);
	debug("| [%dB %s] ",
	      tx_buf || rx_buf ? op->data.nbytes : 0,
	      tx_buf || rx_buf ? (tx_buf ? "out" : "in") : "-");
	for (i = 0; i < op->data.nbytes; i++)
		debug("%02x ", tx_buf ? tx_buf[i] : rx_buf[i]);
	debug("[ret %d]\n", ret);

	if (ret < 0)
		return ret;
#endif /* __UBOOT__ */

	return 0;
}
EXPORT_SYMBOL_GPL(spi_mem_exec_op);

/**
 * spi_mem_adjust_op_size() - Adjust the data size of a SPI mem operation to
 *				 match controller limitations
 * @slave: the SPI device
 * @op: the operation to adjust
 *
 * Some controllers have FIFO limitations and must split a data transfer
 * operation into multiple ones, others require a specific alignment for
 * optimized accesses. This function allows SPI mem drivers to split a single
 * operation into multiple sub-operations when required.
 *
 * Return: a negative error code if the controller can't properly adjust @op,
 *	   0 otherwise. Note that @op->data.nbytes will be updated if @op
 *	   can't be handled in a single step.
 */
int spi_mem_adjust_op_size(struct spi_slave *slave, struct spi_mem_op *op)
{
	struct udevice *bus = slave->dev->parent;
	struct dm_spi_ops *ops = spi_get_ops(bus);

	if (ops->mem_ops && ops->mem_ops->adjust_op_size)
		return ops->mem_ops->adjust_op_size(slave, op);

	if (!ops->mem_ops || !ops->mem_ops->exec_op) {
		unsigned int len;

		len = sizeof(op->cmd.opcode) + op->addr.nbytes +
			op->dummy.nbytes;
		if (slave->max_write_size && len > slave->max_write_size)
			return -EINVAL;

		if (op->data.dir == SPI_MEM_DATA_IN) {
			if (slave->max_read_size)
				op->data.nbytes = min(op->data.nbytes,
					      slave->max_read_size);
		} else if (slave->max_write_size) {
			op->data.nbytes = min(op->data.nbytes,
					      slave->max_write_size - len);
		}

		if (!op->data.nbytes)
			return -EINVAL;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(spi_mem_adjust_op_size);

#ifndef __UBOOT__
static inline struct spi_mem_driver *to_spi_mem_drv(struct device_driver *drv)
{
	return container_of(drv, struct spi_mem_driver, spidrv.driver);
}

static int spi_mem_probe(struct spi_device *spi)
{
	struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
	struct spi_mem *mem;

	mem = devm_kzalloc(&spi->dev, sizeof(*mem), GFP_KERNEL);
	if (!mem)
		return -ENOMEM;

	mem->spi = spi;
	spi_set_drvdata(spi, mem);

	return memdrv->probe(mem);
}

static int spi_mem_remove(struct spi_device *spi)
{
	struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
	struct spi_mem *mem = spi_get_drvdata(spi);

	if (memdrv->remove)
		return memdrv->remove(mem);

	return 0;
}

static void spi_mem_shutdown(struct spi_device *spi)
{
	struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
	struct spi_mem *mem = spi_get_drvdata(spi);

	if (memdrv->shutdown)
		memdrv->shutdown(mem);
}

/**
 * spi_mem_driver_register_with_owner() - Register a SPI memory driver
 * @memdrv: the SPI memory driver to register
 * @owner: the owner of this driver
 *
 * Registers a SPI memory driver.
 *
 * Return: 0 in case of success, a negative error core otherwise.
 */

int spi_mem_driver_register_with_owner(struct spi_mem_driver *memdrv,
				       struct module *owner)
{
	memdrv->spidrv.probe = spi_mem_probe;
	memdrv->spidrv.remove = spi_mem_remove;
	memdrv->spidrv.shutdown = spi_mem_shutdown;

	return __spi_register_driver(owner, &memdrv->spidrv);
}
EXPORT_SYMBOL_GPL(spi_mem_driver_register_with_owner);

/**
 * spi_mem_driver_unregister_with_owner() - Unregister a SPI memory driver
 * @memdrv: the SPI memory driver to unregister
 *
 * Unregisters a SPI memory driver.
 */
void spi_mem_driver_unregister(struct spi_mem_driver *memdrv)
{
	spi_unregister_driver(&memdrv->spidrv);
}
EXPORT_SYMBOL_GPL(spi_mem_driver_unregister);
#endif /* __UBOOT__ */