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path: root/drivers/spi/spi-dln2.c
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-rw-r--r--drivers/spi/spi-dln2.c881
1 files changed, 881 insertions, 0 deletions
diff --git a/drivers/spi/spi-dln2.c b/drivers/spi/spi-dln2.c
new file mode 100644
index 000000000000..3b7d91d94fea
--- /dev/null
+++ b/drivers/spi/spi-dln2.c
@@ -0,0 +1,881 @@
1/*
2 * Driver for the Diolan DLN-2 USB-SPI adapter
3 *
4 * Copyright (c) 2014 Intel Corporation
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation, version 2.
9 */
10
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/platform_device.h>
14#include <linux/mfd/dln2.h>
15#include <linux/spi/spi.h>
16#include <linux/pm_runtime.h>
17#include <asm/unaligned.h>
18
19#define DLN2_SPI_MODULE_ID 0x02
20#define DLN2_SPI_CMD(cmd) DLN2_CMD(cmd, DLN2_SPI_MODULE_ID)
21
22/* SPI commands */
23#define DLN2_SPI_GET_PORT_COUNT DLN2_SPI_CMD(0x00)
24#define DLN2_SPI_ENABLE DLN2_SPI_CMD(0x11)
25#define DLN2_SPI_DISABLE DLN2_SPI_CMD(0x12)
26#define DLN2_SPI_IS_ENABLED DLN2_SPI_CMD(0x13)
27#define DLN2_SPI_SET_MODE DLN2_SPI_CMD(0x14)
28#define DLN2_SPI_GET_MODE DLN2_SPI_CMD(0x15)
29#define DLN2_SPI_SET_FRAME_SIZE DLN2_SPI_CMD(0x16)
30#define DLN2_SPI_GET_FRAME_SIZE DLN2_SPI_CMD(0x17)
31#define DLN2_SPI_SET_FREQUENCY DLN2_SPI_CMD(0x18)
32#define DLN2_SPI_GET_FREQUENCY DLN2_SPI_CMD(0x19)
33#define DLN2_SPI_READ_WRITE DLN2_SPI_CMD(0x1A)
34#define DLN2_SPI_READ DLN2_SPI_CMD(0x1B)
35#define DLN2_SPI_WRITE DLN2_SPI_CMD(0x1C)
36#define DLN2_SPI_SET_DELAY_BETWEEN_SS DLN2_SPI_CMD(0x20)
37#define DLN2_SPI_GET_DELAY_BETWEEN_SS DLN2_SPI_CMD(0x21)
38#define DLN2_SPI_SET_DELAY_AFTER_SS DLN2_SPI_CMD(0x22)
39#define DLN2_SPI_GET_DELAY_AFTER_SS DLN2_SPI_CMD(0x23)
40#define DLN2_SPI_SET_DELAY_BETWEEN_FRAMES DLN2_SPI_CMD(0x24)
41#define DLN2_SPI_GET_DELAY_BETWEEN_FRAMES DLN2_SPI_CMD(0x25)
42#define DLN2_SPI_SET_SS DLN2_SPI_CMD(0x26)
43#define DLN2_SPI_GET_SS DLN2_SPI_CMD(0x27)
44#define DLN2_SPI_RELEASE_SS DLN2_SPI_CMD(0x28)
45#define DLN2_SPI_SS_VARIABLE_ENABLE DLN2_SPI_CMD(0x2B)
46#define DLN2_SPI_SS_VARIABLE_DISABLE DLN2_SPI_CMD(0x2C)
47#define DLN2_SPI_SS_VARIABLE_IS_ENABLED DLN2_SPI_CMD(0x2D)
48#define DLN2_SPI_SS_AAT_ENABLE DLN2_SPI_CMD(0x2E)
49#define DLN2_SPI_SS_AAT_DISABLE DLN2_SPI_CMD(0x2F)
50#define DLN2_SPI_SS_AAT_IS_ENABLED DLN2_SPI_CMD(0x30)
51#define DLN2_SPI_SS_BETWEEN_FRAMES_ENABLE DLN2_SPI_CMD(0x31)
52#define DLN2_SPI_SS_BETWEEN_FRAMES_DISABLE DLN2_SPI_CMD(0x32)
53#define DLN2_SPI_SS_BETWEEN_FRAMES_IS_ENABLED DLN2_SPI_CMD(0x33)
54#define DLN2_SPI_SET_CPHA DLN2_SPI_CMD(0x34)
55#define DLN2_SPI_GET_CPHA DLN2_SPI_CMD(0x35)
56#define DLN2_SPI_SET_CPOL DLN2_SPI_CMD(0x36)
57#define DLN2_SPI_GET_CPOL DLN2_SPI_CMD(0x37)
58#define DLN2_SPI_SS_MULTI_ENABLE DLN2_SPI_CMD(0x38)
59#define DLN2_SPI_SS_MULTI_DISABLE DLN2_SPI_CMD(0x39)
60#define DLN2_SPI_SS_MULTI_IS_ENABLED DLN2_SPI_CMD(0x3A)
61#define DLN2_SPI_GET_SUPPORTED_MODES DLN2_SPI_CMD(0x40)
62#define DLN2_SPI_GET_SUPPORTED_CPHA_VALUES DLN2_SPI_CMD(0x41)
63#define DLN2_SPI_GET_SUPPORTED_CPOL_VALUES DLN2_SPI_CMD(0x42)
64#define DLN2_SPI_GET_SUPPORTED_FRAME_SIZES DLN2_SPI_CMD(0x43)
65#define DLN2_SPI_GET_SS_COUNT DLN2_SPI_CMD(0x44)
66#define DLN2_SPI_GET_MIN_FREQUENCY DLN2_SPI_CMD(0x45)
67#define DLN2_SPI_GET_MAX_FREQUENCY DLN2_SPI_CMD(0x46)
68#define DLN2_SPI_GET_MIN_DELAY_BETWEEN_SS DLN2_SPI_CMD(0x47)
69#define DLN2_SPI_GET_MAX_DELAY_BETWEEN_SS DLN2_SPI_CMD(0x48)
70#define DLN2_SPI_GET_MIN_DELAY_AFTER_SS DLN2_SPI_CMD(0x49)
71#define DLN2_SPI_GET_MAX_DELAY_AFTER_SS DLN2_SPI_CMD(0x4A)
72#define DLN2_SPI_GET_MIN_DELAY_BETWEEN_FRAMES DLN2_SPI_CMD(0x4B)
73#define DLN2_SPI_GET_MAX_DELAY_BETWEEN_FRAMES DLN2_SPI_CMD(0x4C)
74
75#define DLN2_SPI_MAX_XFER_SIZE 256
76#define DLN2_SPI_BUF_SIZE (DLN2_SPI_MAX_XFER_SIZE + 16)
77#define DLN2_SPI_ATTR_LEAVE_SS_LOW BIT(0)
78#define DLN2_TRANSFERS_WAIT_COMPLETE 1
79#define DLN2_TRANSFERS_CANCEL 0
80#define DLN2_RPM_AUTOSUSPEND_TIMEOUT 2000
81
82struct dln2_spi {
83 struct platform_device *pdev;
84 struct spi_master *master;
85 u8 port;
86
87 /*
88 * This buffer will be used mainly for read/write operations. Since
89 * they're quite large, we cannot use the stack. Protection is not
90 * needed because all SPI communication is serialized by the SPI core.
91 */
92 void *buf;
93
94 u8 bpw;
95 u32 speed;
96 u16 mode;
97 u8 cs;
98};
99
100/*
101 * Enable/Disable SPI module. The disable command will wait for transfers to
102 * complete first.
103 */
104static int dln2_spi_enable(struct dln2_spi *dln2, bool enable)
105{
106 u16 cmd;
107 struct {
108 u8 port;
109 u8 wait_for_completion;
110 } tx;
111 unsigned len = sizeof(tx);
112
113 tx.port = dln2->port;
114
115 if (enable) {
116 cmd = DLN2_SPI_ENABLE;
117 len -= sizeof(tx.wait_for_completion);
118 } else {
119 tx.wait_for_completion = DLN2_TRANSFERS_WAIT_COMPLETE;
120 cmd = DLN2_SPI_DISABLE;
121 }
122
123 return dln2_transfer_tx(dln2->pdev, cmd, &tx, len);
124}
125
126/*
127 * Select/unselect multiple CS lines. The selected lines will be automatically
128 * toggled LOW/HIGH by the board firmware during transfers, provided they're
129 * enabled first.
130 *
131 * Ex: cs_mask = 0x03 -> CS0 & CS1 will be selected and the next WR/RD operation
132 * will toggle the lines LOW/HIGH automatically.
133 */
134static int dln2_spi_cs_set(struct dln2_spi *dln2, u8 cs_mask)
135{
136 struct {
137 u8 port;
138 u8 cs;
139 } tx;
140
141 tx.port = dln2->port;
142
143 /*
144 * According to Diolan docs, "a slave device can be selected by changing
145 * the corresponding bit value to 0". The rest must be set to 1. Hence
146 * the bitwise NOT in front.
147 */
148 tx.cs = ~cs_mask;
149
150 return dln2_transfer_tx(dln2->pdev, DLN2_SPI_SET_SS, &tx, sizeof(tx));
151}
152
153/*
154 * Select one CS line. The other lines will be un-selected.
155 */
156static int dln2_spi_cs_set_one(struct dln2_spi *dln2, u8 cs)
157{
158 return dln2_spi_cs_set(dln2, BIT(cs));
159}
160
161/*
162 * Enable/disable CS lines for usage. The module has to be disabled first.
163 */
164static int dln2_spi_cs_enable(struct dln2_spi *dln2, u8 cs_mask, bool enable)
165{
166 struct {
167 u8 port;
168 u8 cs;
169 } tx;
170 u16 cmd;
171
172 tx.port = dln2->port;
173 tx.cs = cs_mask;
174 cmd = enable ? DLN2_SPI_SS_MULTI_ENABLE : DLN2_SPI_SS_MULTI_DISABLE;
175
176 return dln2_transfer_tx(dln2->pdev, cmd, &tx, sizeof(tx));
177}
178
179static int dln2_spi_cs_enable_all(struct dln2_spi *dln2, bool enable)
180{
181 u8 cs_mask = GENMASK(dln2->master->num_chipselect - 1, 0);
182
183 return dln2_spi_cs_enable(dln2, cs_mask, enable);
184}
185
186static int dln2_spi_get_cs_num(struct dln2_spi *dln2, u16 *cs_num)
187{
188 int ret;
189 struct {
190 u8 port;
191 } tx;
192 struct {
193 __le16 cs_count;
194 } rx;
195 unsigned rx_len = sizeof(rx);
196
197 tx.port = dln2->port;
198 ret = dln2_transfer(dln2->pdev, DLN2_SPI_GET_SS_COUNT, &tx, sizeof(tx),
199 &rx, &rx_len);
200 if (ret < 0)
201 return ret;
202 if (rx_len < sizeof(rx))
203 return -EPROTO;
204
205 *cs_num = le16_to_cpu(rx.cs_count);
206
207 dev_dbg(&dln2->pdev->dev, "cs_num = %d\n", *cs_num);
208
209 return 0;
210}
211
212static int dln2_spi_get_speed(struct dln2_spi *dln2, u16 cmd, u32 *freq)
213{
214 int ret;
215 struct {
216 u8 port;
217 } tx;
218 struct {
219 __le32 speed;
220 } rx;
221 unsigned rx_len = sizeof(rx);
222
223 tx.port = dln2->port;
224
225 ret = dln2_transfer(dln2->pdev, cmd, &tx, sizeof(tx), &rx, &rx_len);
226 if (ret < 0)
227 return ret;
228 if (rx_len < sizeof(rx))
229 return -EPROTO;
230
231 *freq = le32_to_cpu(rx.speed);
232
233 return 0;
234}
235
236/*
237 * Get bus min/max frequencies.
238 */
239static int dln2_spi_get_speed_range(struct dln2_spi *dln2, u32 *fmin, u32 *fmax)
240{
241 int ret;
242
243 ret = dln2_spi_get_speed(dln2, DLN2_SPI_GET_MIN_FREQUENCY, fmin);
244 if (ret < 0)
245 return ret;
246
247 ret = dln2_spi_get_speed(dln2, DLN2_SPI_GET_MAX_FREQUENCY, fmax);
248 if (ret < 0)
249 return ret;
250
251 dev_dbg(&dln2->pdev->dev, "freq_min = %d, freq_max = %d\n",
252 *fmin, *fmax);
253
254 return 0;
255}
256
257/*
258 * Set the bus speed. The module will automatically round down to the closest
259 * available frequency and returns it. The module has to be disabled first.
260 */
261static int dln2_spi_set_speed(struct dln2_spi *dln2, u32 speed)
262{
263 int ret;
264 struct {
265 u8 port;
266 __le32 speed;
267 } __packed tx;
268 struct {
269 __le32 speed;
270 } rx;
271 int rx_len = sizeof(rx);
272
273 tx.port = dln2->port;
274 tx.speed = cpu_to_le32(speed);
275
276 ret = dln2_transfer(dln2->pdev, DLN2_SPI_SET_FREQUENCY, &tx, sizeof(tx),
277 &rx, &rx_len);
278 if (ret < 0)
279 return ret;
280 if (rx_len < sizeof(rx))
281 return -EPROTO;
282
283 return 0;
284}
285
286/*
287 * Change CPOL & CPHA. The module has to be disabled first.
288 */
289static int dln2_spi_set_mode(struct dln2_spi *dln2, u8 mode)
290{
291 struct {
292 u8 port;
293 u8 mode;
294 } tx;
295
296 tx.port = dln2->port;
297 tx.mode = mode;
298
299 return dln2_transfer_tx(dln2->pdev, DLN2_SPI_SET_MODE, &tx, sizeof(tx));
300}
301
302/*
303 * Change frame size. The module has to be disabled first.
304 */
305static int dln2_spi_set_bpw(struct dln2_spi *dln2, u8 bpw)
306{
307 struct {
308 u8 port;
309 u8 bpw;
310 } tx;
311
312 tx.port = dln2->port;
313 tx.bpw = bpw;
314
315 return dln2_transfer_tx(dln2->pdev, DLN2_SPI_SET_FRAME_SIZE,
316 &tx, sizeof(tx));
317}
318
319static int dln2_spi_get_supported_frame_sizes(struct dln2_spi *dln2,
320 u32 *bpw_mask)
321{
322 int ret;
323 struct {
324 u8 port;
325 } tx;
326 struct {
327 u8 count;
328 u8 frame_sizes[36];
329 } *rx = dln2->buf;
330 unsigned rx_len = sizeof(*rx);
331 int i;
332
333 tx.port = dln2->port;
334
335 ret = dln2_transfer(dln2->pdev, DLN2_SPI_GET_SUPPORTED_FRAME_SIZES,
336 &tx, sizeof(tx), rx, &rx_len);
337 if (ret < 0)
338 return ret;
339 if (rx_len < sizeof(*rx))
340 return -EPROTO;
341 if (rx->count > ARRAY_SIZE(rx->frame_sizes))
342 return -EPROTO;
343
344 *bpw_mask = 0;
345 for (i = 0; i < rx->count; i++)
346 *bpw_mask |= BIT(rx->frame_sizes[i] - 1);
347
348 dev_dbg(&dln2->pdev->dev, "bpw_mask = 0x%X\n", *bpw_mask);
349
350 return 0;
351}
352
353/*
354 * Copy the data to DLN2 buffer and change the byte order to LE, requested by
355 * DLN2 module. SPI core makes sure that the data length is a multiple of word
356 * size.
357 */
358static int dln2_spi_copy_to_buf(u8 *dln2_buf, const u8 *src, u16 len, u8 bpw)
359{
360#ifdef __LITTLE_ENDIAN
361 memcpy(dln2_buf, src, len);
362#else
363 if (bpw <= 8) {
364 memcpy(dln2_buf, src, len);
365 } else if (bpw <= 16) {
366 __le16 *d = (__le16 *)dln2_buf;
367 u16 *s = (u16 *)src;
368
369 len = len / 2;
370 while (len--)
371 *d++ = cpu_to_le16p(s++);
372 } else {
373 __le32 *d = (__le32 *)dln2_buf;
374 u32 *s = (u32 *)src;
375
376 len = len / 4;
377 while (len--)
378 *d++ = cpu_to_le32p(s++);
379 }
380#endif
381
382 return 0;
383}
384
385/*
386 * Copy the data from DLN2 buffer and convert to CPU byte order since the DLN2
387 * buffer is LE ordered. SPI core makes sure that the data length is a multiple
388 * of word size. The RX dln2_buf is 2 byte aligned so, for BE, we have to make
389 * sure we avoid unaligned accesses for 32 bit case.
390 */
391static int dln2_spi_copy_from_buf(u8 *dest, const u8 *dln2_buf, u16 len, u8 bpw)
392{
393#ifdef __LITTLE_ENDIAN
394 memcpy(dest, dln2_buf, len);
395#else
396 if (bpw <= 8) {
397 memcpy(dest, dln2_buf, len);
398 } else if (bpw <= 16) {
399 u16 *d = (u16 *)dest;
400 __le16 *s = (__le16 *)dln2_buf;
401
402 len = len / 2;
403 while (len--)
404 *d++ = le16_to_cpup(s++);
405 } else {
406 u32 *d = (u32 *)dest;
407 __le32 *s = (__le32 *)dln2_buf;
408
409 len = len / 4;
410 while (len--)
411 *d++ = get_unaligned_le32(s++);
412 }
413#endif
414
415 return 0;
416}
417
418/*
419 * Perform one write operation.
420 */
421static int dln2_spi_write_one(struct dln2_spi *dln2, const u8 *data,
422 u16 data_len, u8 attr)
423{
424 struct {
425 u8 port;
426 __le16 size;
427 u8 attr;
428 u8 buf[DLN2_SPI_MAX_XFER_SIZE];
429 } __packed *tx = dln2->buf;
430 unsigned tx_len;
431
432 BUILD_BUG_ON(sizeof(*tx) > DLN2_SPI_BUF_SIZE);
433
434 if (data_len > DLN2_SPI_MAX_XFER_SIZE)
435 return -EINVAL;
436
437 tx->port = dln2->port;
438 tx->size = cpu_to_le16(data_len);
439 tx->attr = attr;
440
441 dln2_spi_copy_to_buf(tx->buf, data, data_len, dln2->bpw);
442
443 tx_len = sizeof(*tx) + data_len - DLN2_SPI_MAX_XFER_SIZE;
444 return dln2_transfer_tx(dln2->pdev, DLN2_SPI_WRITE, tx, tx_len);
445}
446
447/*
448 * Perform one read operation.
449 */
450static int dln2_spi_read_one(struct dln2_spi *dln2, u8 *data,
451 u16 data_len, u8 attr)
452{
453 int ret;
454 struct {
455 u8 port;
456 __le16 size;
457 u8 attr;
458 } __packed tx;
459 struct {
460 __le16 size;
461 u8 buf[DLN2_SPI_MAX_XFER_SIZE];
462 } __packed *rx = dln2->buf;
463 unsigned rx_len = sizeof(*rx);
464
465 BUILD_BUG_ON(sizeof(*rx) > DLN2_SPI_BUF_SIZE);
466
467 if (data_len > DLN2_SPI_MAX_XFER_SIZE)
468 return -EINVAL;
469
470 tx.port = dln2->port;
471 tx.size = cpu_to_le16(data_len);
472 tx.attr = attr;
473
474 ret = dln2_transfer(dln2->pdev, DLN2_SPI_READ, &tx, sizeof(tx),
475 rx, &rx_len);
476 if (ret < 0)
477 return ret;
478 if (rx_len < sizeof(rx->size) + data_len)
479 return -EPROTO;
480 if (le16_to_cpu(rx->size) != data_len)
481 return -EPROTO;
482
483 dln2_spi_copy_from_buf(data, rx->buf, data_len, dln2->bpw);
484
485 return 0;
486}
487
488/*
489 * Perform one write & read operation.
490 */
491static int dln2_spi_read_write_one(struct dln2_spi *dln2, const u8 *tx_data,
492 u8 *rx_data, u16 data_len, u8 attr)
493{
494 int ret;
495 struct {
496 u8 port;
497 __le16 size;
498 u8 attr;
499 u8 buf[DLN2_SPI_MAX_XFER_SIZE];
500 } __packed *tx;
501 struct {
502 __le16 size;
503 u8 buf[DLN2_SPI_MAX_XFER_SIZE];
504 } __packed *rx;
505 unsigned tx_len, rx_len;
506
507 BUILD_BUG_ON(sizeof(*tx) > DLN2_SPI_BUF_SIZE ||
508 sizeof(*rx) > DLN2_SPI_BUF_SIZE);
509
510 if (data_len > DLN2_SPI_MAX_XFER_SIZE)
511 return -EINVAL;
512
513 /*
514 * Since this is a pseudo full-duplex communication, we're perfectly
515 * safe to use the same buffer for both tx and rx. When DLN2 sends the
516 * response back, with the rx data, we don't need the tx buffer anymore.
517 */
518 tx = dln2->buf;
519 rx = dln2->buf;
520
521 tx->port = dln2->port;
522 tx->size = cpu_to_le16(data_len);
523 tx->attr = attr;
524
525 dln2_spi_copy_to_buf(tx->buf, tx_data, data_len, dln2->bpw);
526
527 tx_len = sizeof(*tx) + data_len - DLN2_SPI_MAX_XFER_SIZE;
528 rx_len = sizeof(*rx);
529
530 ret = dln2_transfer(dln2->pdev, DLN2_SPI_READ_WRITE, tx, tx_len,
531 rx, &rx_len);
532 if (ret < 0)
533 return ret;
534 if (rx_len < sizeof(rx->size) + data_len)
535 return -EPROTO;
536 if (le16_to_cpu(rx->size) != data_len)
537 return -EPROTO;
538
539 dln2_spi_copy_from_buf(rx_data, rx->buf, data_len, dln2->bpw);
540
541 return 0;
542}
543
544/*
545 * Read/Write wrapper. It will automatically split an operation into multiple
546 * single ones due to device buffer constraints.
547 */
548static int dln2_spi_rdwr(struct dln2_spi *dln2, const u8 *tx_data,
549 u8 *rx_data, u16 data_len, u8 attr) {
550 int ret;
551 u16 len;
552 u8 temp_attr;
553 u16 remaining = data_len;
554 u16 offset;
555
556 do {
557 if (remaining > DLN2_SPI_MAX_XFER_SIZE) {
558 len = DLN2_SPI_MAX_XFER_SIZE;
559 temp_attr = DLN2_SPI_ATTR_LEAVE_SS_LOW;
560 } else {
561 len = remaining;
562 temp_attr = attr;
563 }
564
565 offset = data_len - remaining;
566
567 if (tx_data && rx_data) {
568 ret = dln2_spi_read_write_one(dln2,
569 tx_data + offset,
570 rx_data + offset,
571 len, temp_attr);
572 } else if (tx_data) {
573 ret = dln2_spi_write_one(dln2,
574 tx_data + offset,
575 len, temp_attr);
576 } else if (rx_data) {
577 ret = dln2_spi_read_one(dln2,
578 rx_data + offset,
579 len, temp_attr);
580 } else {
581 return -EINVAL;
582 }
583
584 if (ret < 0)
585 return ret;
586
587 remaining -= len;
588 } while (remaining);
589
590 return 0;
591}
592
593static int dln2_spi_prepare_message(struct spi_master *master,
594 struct spi_message *message)
595{
596 int ret;
597 struct dln2_spi *dln2 = spi_master_get_devdata(master);
598 struct spi_device *spi = message->spi;
599
600 if (dln2->cs != spi->chip_select) {
601 ret = dln2_spi_cs_set_one(dln2, spi->chip_select);
602 if (ret < 0)
603 return ret;
604
605 dln2->cs = spi->chip_select;
606 }
607
608 return 0;
609}
610
611static int dln2_spi_transfer_setup(struct dln2_spi *dln2, u32 speed,
612 u8 bpw, u8 mode)
613{
614 int ret;
615 bool bus_setup_change;
616
617 bus_setup_change = dln2->speed != speed || dln2->mode != mode ||
618 dln2->bpw != bpw;
619
620 if (!bus_setup_change)
621 return 0;
622
623 ret = dln2_spi_enable(dln2, false);
624 if (ret < 0)
625 return ret;
626
627 if (dln2->speed != speed) {
628 ret = dln2_spi_set_speed(dln2, speed);
629 if (ret < 0)
630 return ret;
631
632 dln2->speed = speed;
633 }
634
635 if (dln2->mode != mode) {
636 ret = dln2_spi_set_mode(dln2, mode & 0x3);
637 if (ret < 0)
638 return ret;
639
640 dln2->mode = mode;
641 }
642
643 if (dln2->bpw != bpw) {
644 ret = dln2_spi_set_bpw(dln2, bpw);
645 if (ret < 0)
646 return ret;
647
648 dln2->bpw = bpw;
649 }
650
651 return dln2_spi_enable(dln2, true);
652}
653
654static int dln2_spi_transfer_one(struct spi_master *master,
655 struct spi_device *spi,
656 struct spi_transfer *xfer)
657{
658 struct dln2_spi *dln2 = spi_master_get_devdata(master);
659 int status;
660 u8 attr = 0;
661
662 status = dln2_spi_transfer_setup(dln2, xfer->speed_hz,
663 xfer->bits_per_word,
664 spi->mode);
665 if (status < 0) {
666 dev_err(&dln2->pdev->dev, "Cannot setup transfer\n");
667 return status;
668 }
669
670 if (!xfer->cs_change && !spi_transfer_is_last(master, xfer))
671 attr = DLN2_SPI_ATTR_LEAVE_SS_LOW;
672
673 status = dln2_spi_rdwr(dln2, xfer->tx_buf, xfer->rx_buf,
674 xfer->len, attr);
675 if (status < 0)
676 dev_err(&dln2->pdev->dev, "write/read failed!\n");
677
678 return status;
679}
680
681static int dln2_spi_probe(struct platform_device *pdev)
682{
683 struct spi_master *master;
684 struct dln2_spi *dln2;
685 struct dln2_platform_data *pdata = dev_get_platdata(&pdev->dev);
686 int ret;
687
688 master = spi_alloc_master(&pdev->dev, sizeof(*dln2));
689 if (!master)
690 return -ENOMEM;
691
692 platform_set_drvdata(pdev, master);
693
694 dln2 = spi_master_get_devdata(master);
695
696 dln2->buf = devm_kmalloc(&pdev->dev, DLN2_SPI_BUF_SIZE, GFP_KERNEL);
697 if (!dln2->buf) {
698 ret = -ENOMEM;
699 goto exit_free_master;
700 }
701
702 dln2->master = master;
703 dln2->pdev = pdev;
704 dln2->port = pdata->port;
705 /* cs/mode can never be 0xff, so the first transfer will set them */
706 dln2->cs = 0xff;
707 dln2->mode = 0xff;
708
709 /* disable SPI module before continuing with the setup */
710 ret = dln2_spi_enable(dln2, false);
711 if (ret < 0) {
712 dev_err(&pdev->dev, "Failed to disable SPI module\n");
713 goto exit_free_master;
714 }
715
716 ret = dln2_spi_get_cs_num(dln2, &master->num_chipselect);
717 if (ret < 0) {
718 dev_err(&pdev->dev, "Failed to get number of CS pins\n");
719 goto exit_free_master;
720 }
721
722 ret = dln2_spi_get_speed_range(dln2,
723 &master->min_speed_hz,
724 &master->max_speed_hz);
725 if (ret < 0) {
726 dev_err(&pdev->dev, "Failed to read bus min/max freqs\n");
727 goto exit_free_master;
728 }
729
730 ret = dln2_spi_get_supported_frame_sizes(dln2,
731 &master->bits_per_word_mask);
732 if (ret < 0) {
733 dev_err(&pdev->dev, "Failed to read supported frame sizes\n");
734 goto exit_free_master;
735 }
736
737 ret = dln2_spi_cs_enable_all(dln2, true);
738 if (ret < 0) {
739 dev_err(&pdev->dev, "Failed to enable CS pins\n");
740 goto exit_free_master;
741 }
742
743 master->bus_num = -1;
744 master->mode_bits = SPI_CPOL | SPI_CPHA;
745 master->prepare_message = dln2_spi_prepare_message;
746 master->transfer_one = dln2_spi_transfer_one;
747 master->auto_runtime_pm = true;
748
749 /* enable SPI module, we're good to go */
750 ret = dln2_spi_enable(dln2, true);
751 if (ret < 0) {
752 dev_err(&pdev->dev, "Failed to enable SPI module\n");
753 goto exit_free_master;
754 }
755
756 pm_runtime_set_autosuspend_delay(&pdev->dev,
757 DLN2_RPM_AUTOSUSPEND_TIMEOUT);
758 pm_runtime_use_autosuspend(&pdev->dev);
759 pm_runtime_set_active(&pdev->dev);
760 pm_runtime_enable(&pdev->dev);
761
762 ret = devm_spi_register_master(&pdev->dev, master);
763 if (ret < 0) {
764 dev_err(&pdev->dev, "Failed to register master\n");
765 goto exit_register;
766 }
767
768 return ret;
769
770exit_register:
771 pm_runtime_disable(&pdev->dev);
772 pm_runtime_set_suspended(&pdev->dev);
773
774 if (dln2_spi_enable(dln2, false) < 0)
775 dev_err(&pdev->dev, "Failed to disable SPI module\n");
776exit_free_master:
777 spi_master_put(master);
778
779 return ret;
780}
781
782static int dln2_spi_remove(struct platform_device *pdev)
783{
784 struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
785 struct dln2_spi *dln2 = spi_master_get_devdata(master);
786
787 pm_runtime_disable(&pdev->dev);
788
789 if (dln2_spi_enable(dln2, false) < 0)
790 dev_err(&pdev->dev, "Failed to disable SPI module\n");
791
792 return 0;
793}
794
795#ifdef CONFIG_PM_SLEEP
796static int dln2_spi_suspend(struct device *dev)
797{
798 int ret;
799 struct spi_master *master = dev_get_drvdata(dev);
800 struct dln2_spi *dln2 = spi_master_get_devdata(master);
801
802 ret = spi_master_suspend(master);
803 if (ret < 0)
804 return ret;
805
806 if (!pm_runtime_suspended(dev)) {
807 ret = dln2_spi_enable(dln2, false);
808 if (ret < 0)
809 return ret;
810 }
811
812 /*
813 * USB power may be cut off during sleep. Resetting the following
814 * parameters will force the board to be set up before first transfer.
815 */
816 dln2->cs = 0xff;
817 dln2->speed = 0;
818 dln2->bpw = 0;
819 dln2->mode = 0xff;
820
821 return 0;
822}
823
824static int dln2_spi_resume(struct device *dev)
825{
826 int ret;
827 struct spi_master *master = dev_get_drvdata(dev);
828 struct dln2_spi *dln2 = spi_master_get_devdata(master);
829
830 if (!pm_runtime_suspended(dev)) {
831 ret = dln2_spi_cs_enable_all(dln2, true);
832 if (ret < 0)
833 return ret;
834
835 ret = dln2_spi_enable(dln2, true);
836 if (ret < 0)
837 return ret;
838 }
839
840 return spi_master_resume(master);
841}
842#endif /* CONFIG_PM_SLEEP */
843
844#ifdef CONFIG_PM
845static int dln2_spi_runtime_suspend(struct device *dev)
846{
847 struct spi_master *master = dev_get_drvdata(dev);
848 struct dln2_spi *dln2 = spi_master_get_devdata(master);
849
850 return dln2_spi_enable(dln2, false);
851}
852
853static int dln2_spi_runtime_resume(struct device *dev)
854{
855 struct spi_master *master = dev_get_drvdata(dev);
856 struct dln2_spi *dln2 = spi_master_get_devdata(master);
857
858 return dln2_spi_enable(dln2, true);
859}
860#endif /* CONFIG_PM */
861
862static const struct dev_pm_ops dln2_spi_pm = {
863 SET_SYSTEM_SLEEP_PM_OPS(dln2_spi_suspend, dln2_spi_resume)
864 SET_RUNTIME_PM_OPS(dln2_spi_runtime_suspend,
865 dln2_spi_runtime_resume, NULL)
866};
867
868static struct platform_driver spi_dln2_driver = {
869 .driver = {
870 .name = "dln2-spi",
871 .pm = &dln2_spi_pm,
872 },
873 .probe = dln2_spi_probe,
874 .remove = dln2_spi_remove,
875};
876module_platform_driver(spi_dln2_driver);
877
878MODULE_DESCRIPTION("Driver for the Diolan DLN2 SPI master interface");
879MODULE_AUTHOR("Laurentiu Palcu <laurentiu.palcu@intel.com>");
880MODULE_LICENSE("GPL v2");
881MODULE_ALIAS("platform:dln2-spi");
generated by cgit v1.2.2 (git 2.25.0) at 2025-11-26 08:06:14 -0500