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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * SPI-Engine SPI controller driver
4 * Copyright 2015 Analog Devices Inc.
5 * Author: Lars-Peter Clausen <lars@metafoo.de>
6 */
7
8#include <linux/clk.h>
9#include <linux/idr.h>
10#include <linux/interrupt.h>
11#include <linux/io.h>
12#include <linux/of.h>
13#include <linux/module.h>
14#include <linux/platform_device.h>
15#include <linux/spi/spi.h>
16#include <linux/timer.h>
17
18#define SPI_ENGINE_VERSION_MAJOR(x) ((x >> 16) & 0xff)
19#define SPI_ENGINE_VERSION_MINOR(x) ((x >> 8) & 0xff)
20#define SPI_ENGINE_VERSION_PATCH(x) (x & 0xff)
21
22#define SPI_ENGINE_REG_VERSION 0x00
23
24#define SPI_ENGINE_REG_RESET 0x40
25
26#define SPI_ENGINE_REG_INT_ENABLE 0x80
27#define SPI_ENGINE_REG_INT_PENDING 0x84
28#define SPI_ENGINE_REG_INT_SOURCE 0x88
29
30#define SPI_ENGINE_REG_SYNC_ID 0xc0
31
32#define SPI_ENGINE_REG_CMD_FIFO_ROOM 0xd0
33#define SPI_ENGINE_REG_SDO_FIFO_ROOM 0xd4
34#define SPI_ENGINE_REG_SDI_FIFO_LEVEL 0xd8
35
36#define SPI_ENGINE_REG_CMD_FIFO 0xe0
37#define SPI_ENGINE_REG_SDO_DATA_FIFO 0xe4
38#define SPI_ENGINE_REG_SDI_DATA_FIFO 0xe8
39#define SPI_ENGINE_REG_SDI_DATA_FIFO_PEEK 0xec
40
41#define SPI_ENGINE_INT_CMD_ALMOST_EMPTY BIT(0)
42#define SPI_ENGINE_INT_SDO_ALMOST_EMPTY BIT(1)
43#define SPI_ENGINE_INT_SDI_ALMOST_FULL BIT(2)
44#define SPI_ENGINE_INT_SYNC BIT(3)
45
46#define SPI_ENGINE_CONFIG_CPHA BIT(0)
47#define SPI_ENGINE_CONFIG_CPOL BIT(1)
48#define SPI_ENGINE_CONFIG_3WIRE BIT(2)
49
50#define SPI_ENGINE_INST_TRANSFER 0x0
51#define SPI_ENGINE_INST_ASSERT 0x1
52#define SPI_ENGINE_INST_WRITE 0x2
53#define SPI_ENGINE_INST_MISC 0x3
54
55#define SPI_ENGINE_CMD_REG_CLK_DIV 0x0
56#define SPI_ENGINE_CMD_REG_CONFIG 0x1
57#define SPI_ENGINE_CMD_REG_XFER_BITS 0x2
58
59#define SPI_ENGINE_MISC_SYNC 0x0
60#define SPI_ENGINE_MISC_SLEEP 0x1
61
62#define SPI_ENGINE_TRANSFER_WRITE 0x1
63#define SPI_ENGINE_TRANSFER_READ 0x2
64
65#define SPI_ENGINE_CMD(inst, arg1, arg2) \
66 (((inst) << 12) | ((arg1) << 8) | (arg2))
67
68#define SPI_ENGINE_CMD_TRANSFER(flags, n) \
69 SPI_ENGINE_CMD(SPI_ENGINE_INST_TRANSFER, (flags), (n))
70#define SPI_ENGINE_CMD_ASSERT(delay, cs) \
71 SPI_ENGINE_CMD(SPI_ENGINE_INST_ASSERT, (delay), (cs))
72#define SPI_ENGINE_CMD_WRITE(reg, val) \
73 SPI_ENGINE_CMD(SPI_ENGINE_INST_WRITE, (reg), (val))
74#define SPI_ENGINE_CMD_SLEEP(delay) \
75 SPI_ENGINE_CMD(SPI_ENGINE_INST_MISC, SPI_ENGINE_MISC_SLEEP, (delay))
76#define SPI_ENGINE_CMD_SYNC(id) \
77 SPI_ENGINE_CMD(SPI_ENGINE_INST_MISC, SPI_ENGINE_MISC_SYNC, (id))
78
79struct spi_engine_program {
80 unsigned int length;
81 uint16_t instructions[];
82};
83
84/**
85 * struct spi_engine_message_state - SPI engine per-message state
86 */
87struct spi_engine_message_state {
88 /** @p: Instructions for executing this message. */
89 struct spi_engine_program *p;
90 /** @cmd_length: Number of elements in cmd_buf array. */
91 unsigned cmd_length;
92 /** @cmd_buf: Array of commands not yet written to CMD FIFO. */
93 const uint16_t *cmd_buf;
94 /** @tx_xfer: Next xfer with tx_buf not yet fully written to TX FIFO. */
95 struct spi_transfer *tx_xfer;
96 /** @tx_length: Size of tx_buf in bytes. */
97 unsigned int tx_length;
98 /** @tx_buf: Bytes not yet written to TX FIFO. */
99 const uint8_t *tx_buf;
100 /** @rx_xfer: Next xfer with rx_buf not yet fully written to RX FIFO. */
101 struct spi_transfer *rx_xfer;
102 /** @rx_length: Size of tx_buf in bytes. */
103 unsigned int rx_length;
104 /** @rx_buf: Bytes not yet written to the RX FIFO. */
105 uint8_t *rx_buf;
106 /** @sync_id: ID to correlate SYNC interrupts with this message. */
107 u8 sync_id;
108};
109
110struct spi_engine {
111 struct clk *clk;
112 struct clk *ref_clk;
113
114 spinlock_t lock;
115
116 void __iomem *base;
117 struct ida sync_ida;
118 struct timer_list watchdog_timer;
119 struct spi_controller *controller;
120
121 unsigned int int_enable;
122};
123
124static void spi_engine_program_add_cmd(struct spi_engine_program *p,
125 bool dry, uint16_t cmd)
126{
127 if (!dry)
128 p->instructions[p->length] = cmd;
129 p->length++;
130}
131
132static unsigned int spi_engine_get_config(struct spi_device *spi)
133{
134 unsigned int config = 0;
135
136 if (spi->mode & SPI_CPOL)
137 config |= SPI_ENGINE_CONFIG_CPOL;
138 if (spi->mode & SPI_CPHA)
139 config |= SPI_ENGINE_CONFIG_CPHA;
140 if (spi->mode & SPI_3WIRE)
141 config |= SPI_ENGINE_CONFIG_3WIRE;
142
143 return config;
144}
145
146static void spi_engine_gen_xfer(struct spi_engine_program *p, bool dry,
147 struct spi_transfer *xfer)
148{
149 unsigned int len;
150
151 if (xfer->bits_per_word <= 8)
152 len = xfer->len;
153 else if (xfer->bits_per_word <= 16)
154 len = xfer->len / 2;
155 else
156 len = xfer->len / 4;
157
158 while (len) {
159 unsigned int n = min(len, 256U);
160 unsigned int flags = 0;
161
162 if (xfer->tx_buf)
163 flags |= SPI_ENGINE_TRANSFER_WRITE;
164 if (xfer->rx_buf)
165 flags |= SPI_ENGINE_TRANSFER_READ;
166
167 spi_engine_program_add_cmd(p, dry,
168 SPI_ENGINE_CMD_TRANSFER(flags, n - 1));
169 len -= n;
170 }
171}
172
173static void spi_engine_gen_sleep(struct spi_engine_program *p, bool dry,
174 int delay_ns, u32 sclk_hz)
175{
176 unsigned int t;
177
178 /* negative delay indicates error, e.g. from spi_delay_to_ns() */
179 if (delay_ns <= 0)
180 return;
181
182 /* rounding down since executing the instruction adds a couple of ticks delay */
183 t = DIV_ROUND_DOWN_ULL((u64)delay_ns * sclk_hz, NSEC_PER_SEC);
184 while (t) {
185 unsigned int n = min(t, 256U);
186
187 spi_engine_program_add_cmd(p, dry, SPI_ENGINE_CMD_SLEEP(n - 1));
188 t -= n;
189 }
190}
191
192static void spi_engine_gen_cs(struct spi_engine_program *p, bool dry,
193 struct spi_device *spi, bool assert)
194{
195 unsigned int mask = 0xff;
196
197 if (assert)
198 mask ^= BIT(spi_get_chipselect(spi, 0));
199
200 spi_engine_program_add_cmd(p, dry, SPI_ENGINE_CMD_ASSERT(0, mask));
201}
202
203/*
204 * Performs precompile steps on the message.
205 *
206 * The SPI core does most of the message/transfer validation and filling in
207 * fields for us via __spi_validate(). This fixes up anything remaining not
208 * done there.
209 *
210 * NB: This is separate from spi_engine_compile_message() because the latter
211 * is called twice and would otherwise result in double-evaluation.
212 */
213static void spi_engine_precompile_message(struct spi_message *msg)
214{
215 unsigned int clk_div, max_hz = msg->spi->controller->max_speed_hz;
216 struct spi_transfer *xfer;
217
218 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
219 clk_div = DIV_ROUND_UP(max_hz, xfer->speed_hz);
220 xfer->effective_speed_hz = max_hz / min(clk_div, 256U);
221 }
222}
223
224static void spi_engine_compile_message(struct spi_message *msg, bool dry,
225 struct spi_engine_program *p)
226{
227 struct spi_device *spi = msg->spi;
228 struct spi_controller *host = spi->controller;
229 struct spi_transfer *xfer;
230 int clk_div, new_clk_div;
231 bool keep_cs = false;
232 u8 bits_per_word = 0;
233
234 clk_div = 1;
235
236 spi_engine_program_add_cmd(p, dry,
237 SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_CONFIG,
238 spi_engine_get_config(spi)));
239
240 xfer = list_first_entry(&msg->transfers, struct spi_transfer, transfer_list);
241 spi_engine_gen_cs(p, dry, spi, !xfer->cs_off);
242
243 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
244 new_clk_div = host->max_speed_hz / xfer->effective_speed_hz;
245 if (new_clk_div != clk_div) {
246 clk_div = new_clk_div;
247 /* actual divider used is register value + 1 */
248 spi_engine_program_add_cmd(p, dry,
249 SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_CLK_DIV,
250 clk_div - 1));
251 }
252
253 if (bits_per_word != xfer->bits_per_word) {
254 bits_per_word = xfer->bits_per_word;
255 spi_engine_program_add_cmd(p, dry,
256 SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_XFER_BITS,
257 bits_per_word));
258 }
259
260 spi_engine_gen_xfer(p, dry, xfer);
261 spi_engine_gen_sleep(p, dry, spi_delay_to_ns(&xfer->delay, xfer),
262 xfer->effective_speed_hz);
263
264 if (xfer->cs_change) {
265 if (list_is_last(&xfer->transfer_list, &msg->transfers)) {
266 keep_cs = true;
267 } else {
268 if (!xfer->cs_off)
269 spi_engine_gen_cs(p, dry, spi, false);
270
271 spi_engine_gen_sleep(p, dry, spi_delay_to_ns(
272 &xfer->cs_change_delay, xfer),
273 xfer->effective_speed_hz);
274
275 if (!list_next_entry(xfer, transfer_list)->cs_off)
276 spi_engine_gen_cs(p, dry, spi, true);
277 }
278 } else if (!list_is_last(&xfer->transfer_list, &msg->transfers) &&
279 xfer->cs_off != list_next_entry(xfer, transfer_list)->cs_off) {
280 spi_engine_gen_cs(p, dry, spi, xfer->cs_off);
281 }
282 }
283
284 if (!keep_cs)
285 spi_engine_gen_cs(p, dry, spi, false);
286
287 /*
288 * Restore clockdiv to default so that future gen_sleep commands don't
289 * have to be aware of the current register state.
290 */
291 if (clk_div != 1)
292 spi_engine_program_add_cmd(p, dry,
293 SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_CLK_DIV, 0));
294}
295
296static void spi_engine_xfer_next(struct spi_message *msg,
297 struct spi_transfer **_xfer)
298{
299 struct spi_transfer *xfer = *_xfer;
300
301 if (!xfer) {
302 xfer = list_first_entry(&msg->transfers,
303 struct spi_transfer, transfer_list);
304 } else if (list_is_last(&xfer->transfer_list, &msg->transfers)) {
305 xfer = NULL;
306 } else {
307 xfer = list_next_entry(xfer, transfer_list);
308 }
309
310 *_xfer = xfer;
311}
312
313static void spi_engine_tx_next(struct spi_message *msg)
314{
315 struct spi_engine_message_state *st = msg->state;
316 struct spi_transfer *xfer = st->tx_xfer;
317
318 do {
319 spi_engine_xfer_next(msg, &xfer);
320 } while (xfer && !xfer->tx_buf);
321
322 st->tx_xfer = xfer;
323 if (xfer) {
324 st->tx_length = xfer->len;
325 st->tx_buf = xfer->tx_buf;
326 } else {
327 st->tx_buf = NULL;
328 }
329}
330
331static void spi_engine_rx_next(struct spi_message *msg)
332{
333 struct spi_engine_message_state *st = msg->state;
334 struct spi_transfer *xfer = st->rx_xfer;
335
336 do {
337 spi_engine_xfer_next(msg, &xfer);
338 } while (xfer && !xfer->rx_buf);
339
340 st->rx_xfer = xfer;
341 if (xfer) {
342 st->rx_length = xfer->len;
343 st->rx_buf = xfer->rx_buf;
344 } else {
345 st->rx_buf = NULL;
346 }
347}
348
349static bool spi_engine_write_cmd_fifo(struct spi_engine *spi_engine,
350 struct spi_message *msg)
351{
352 void __iomem *addr = spi_engine->base + SPI_ENGINE_REG_CMD_FIFO;
353 struct spi_engine_message_state *st = msg->state;
354 unsigned int n, m, i;
355 const uint16_t *buf;
356
357 n = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_CMD_FIFO_ROOM);
358 while (n && st->cmd_length) {
359 m = min(n, st->cmd_length);
360 buf = st->cmd_buf;
361 for (i = 0; i < m; i++)
362 writel_relaxed(buf[i], addr);
363 st->cmd_buf += m;
364 st->cmd_length -= m;
365 n -= m;
366 }
367
368 return st->cmd_length != 0;
369}
370
371static bool spi_engine_write_tx_fifo(struct spi_engine *spi_engine,
372 struct spi_message *msg)
373{
374 void __iomem *addr = spi_engine->base + SPI_ENGINE_REG_SDO_DATA_FIFO;
375 struct spi_engine_message_state *st = msg->state;
376 unsigned int n, m, i;
377
378 n = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_SDO_FIFO_ROOM);
379 while (n && st->tx_length) {
380 if (st->tx_xfer->bits_per_word <= 8) {
381 const u8 *buf = st->tx_buf;
382
383 m = min(n, st->tx_length);
384 for (i = 0; i < m; i++)
385 writel_relaxed(buf[i], addr);
386 st->tx_buf += m;
387 st->tx_length -= m;
388 } else if (st->tx_xfer->bits_per_word <= 16) {
389 const u16 *buf = (const u16 *)st->tx_buf;
390
391 m = min(n, st->tx_length / 2);
392 for (i = 0; i < m; i++)
393 writel_relaxed(buf[i], addr);
394 st->tx_buf += m * 2;
395 st->tx_length -= m * 2;
396 } else {
397 const u32 *buf = (const u32 *)st->tx_buf;
398
399 m = min(n, st->tx_length / 4);
400 for (i = 0; i < m; i++)
401 writel_relaxed(buf[i], addr);
402 st->tx_buf += m * 4;
403 st->tx_length -= m * 4;
404 }
405 n -= m;
406 if (st->tx_length == 0)
407 spi_engine_tx_next(msg);
408 }
409
410 return st->tx_length != 0;
411}
412
413static bool spi_engine_read_rx_fifo(struct spi_engine *spi_engine,
414 struct spi_message *msg)
415{
416 void __iomem *addr = spi_engine->base + SPI_ENGINE_REG_SDI_DATA_FIFO;
417 struct spi_engine_message_state *st = msg->state;
418 unsigned int n, m, i;
419
420 n = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_SDI_FIFO_LEVEL);
421 while (n && st->rx_length) {
422 if (st->rx_xfer->bits_per_word <= 8) {
423 u8 *buf = st->rx_buf;
424
425 m = min(n, st->rx_length);
426 for (i = 0; i < m; i++)
427 buf[i] = readl_relaxed(addr);
428 st->rx_buf += m;
429 st->rx_length -= m;
430 } else if (st->rx_xfer->bits_per_word <= 16) {
431 u16 *buf = (u16 *)st->rx_buf;
432
433 m = min(n, st->rx_length / 2);
434 for (i = 0; i < m; i++)
435 buf[i] = readl_relaxed(addr);
436 st->rx_buf += m * 2;
437 st->rx_length -= m * 2;
438 } else {
439 u32 *buf = (u32 *)st->rx_buf;
440
441 m = min(n, st->rx_length / 4);
442 for (i = 0; i < m; i++)
443 buf[i] = readl_relaxed(addr);
444 st->rx_buf += m * 4;
445 st->rx_length -= m * 4;
446 }
447 n -= m;
448 if (st->rx_length == 0)
449 spi_engine_rx_next(msg);
450 }
451
452 return st->rx_length != 0;
453}
454
455static irqreturn_t spi_engine_irq(int irq, void *devid)
456{
457 struct spi_controller *host = devid;
458 struct spi_message *msg = host->cur_msg;
459 struct spi_engine *spi_engine = spi_controller_get_devdata(host);
460 unsigned int disable_int = 0;
461 unsigned int pending;
462 int completed_id = -1;
463
464 pending = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
465
466 if (pending & SPI_ENGINE_INT_SYNC) {
467 writel_relaxed(SPI_ENGINE_INT_SYNC,
468 spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
469 completed_id = readl_relaxed(
470 spi_engine->base + SPI_ENGINE_REG_SYNC_ID);
471 }
472
473 spin_lock(&spi_engine->lock);
474
475 if (pending & SPI_ENGINE_INT_CMD_ALMOST_EMPTY) {
476 if (!spi_engine_write_cmd_fifo(spi_engine, msg))
477 disable_int |= SPI_ENGINE_INT_CMD_ALMOST_EMPTY;
478 }
479
480 if (pending & SPI_ENGINE_INT_SDO_ALMOST_EMPTY) {
481 if (!spi_engine_write_tx_fifo(spi_engine, msg))
482 disable_int |= SPI_ENGINE_INT_SDO_ALMOST_EMPTY;
483 }
484
485 if (pending & (SPI_ENGINE_INT_SDI_ALMOST_FULL | SPI_ENGINE_INT_SYNC)) {
486 if (!spi_engine_read_rx_fifo(spi_engine, msg))
487 disable_int |= SPI_ENGINE_INT_SDI_ALMOST_FULL;
488 }
489
490 if (pending & SPI_ENGINE_INT_SYNC && msg) {
491 struct spi_engine_message_state *st = msg->state;
492
493 if (completed_id == st->sync_id) {
494 if (timer_delete_sync(&spi_engine->watchdog_timer)) {
495 msg->status = 0;
496 msg->actual_length = msg->frame_length;
497 spi_finalize_current_message(host);
498 }
499 disable_int |= SPI_ENGINE_INT_SYNC;
500 }
501 }
502
503 if (disable_int) {
504 spi_engine->int_enable &= ~disable_int;
505 writel_relaxed(spi_engine->int_enable,
506 spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);
507 }
508
509 spin_unlock(&spi_engine->lock);
510
511 return IRQ_HANDLED;
512}
513
514static int spi_engine_prepare_message(struct spi_controller *host,
515 struct spi_message *msg)
516{
517 struct spi_engine_program p_dry, *p;
518 struct spi_engine *spi_engine = spi_controller_get_devdata(host);
519 struct spi_engine_message_state *st;
520 size_t size;
521 int ret;
522
523 st = kzalloc(sizeof(*st), GFP_KERNEL);
524 if (!st)
525 return -ENOMEM;
526
527 spi_engine_precompile_message(msg);
528
529 p_dry.length = 0;
530 spi_engine_compile_message(msg, true, &p_dry);
531
532 size = sizeof(*p->instructions) * (p_dry.length + 1);
533 p = kzalloc(sizeof(*p) + size, GFP_KERNEL);
534 if (!p) {
535 kfree(st);
536 return -ENOMEM;
537 }
538
539 ret = ida_alloc_range(&spi_engine->sync_ida, 0, U8_MAX, GFP_KERNEL);
540 if (ret < 0) {
541 kfree(p);
542 kfree(st);
543 return ret;
544 }
545
546 st->sync_id = ret;
547
548 spi_engine_compile_message(msg, false, p);
549
550 spi_engine_program_add_cmd(p, false, SPI_ENGINE_CMD_SYNC(st->sync_id));
551
552 st->p = p;
553 st->cmd_buf = p->instructions;
554 st->cmd_length = p->length;
555 msg->state = st;
556
557 return 0;
558}
559
560static int spi_engine_unprepare_message(struct spi_controller *host,
561 struct spi_message *msg)
562{
563 struct spi_engine *spi_engine = spi_controller_get_devdata(host);
564 struct spi_engine_message_state *st = msg->state;
565
566 ida_free(&spi_engine->sync_ida, st->sync_id);
567 kfree(st->p);
568 kfree(st);
569
570 return 0;
571}
572
573static int spi_engine_transfer_one_message(struct spi_controller *host,
574 struct spi_message *msg)
575{
576 struct spi_engine *spi_engine = spi_controller_get_devdata(host);
577 struct spi_engine_message_state *st = msg->state;
578 unsigned int int_enable = 0;
579 unsigned long flags;
580
581 mod_timer(&spi_engine->watchdog_timer, jiffies + msecs_to_jiffies(5000));
582
583 spin_lock_irqsave(&spi_engine->lock, flags);
584
585 if (spi_engine_write_cmd_fifo(spi_engine, msg))
586 int_enable |= SPI_ENGINE_INT_CMD_ALMOST_EMPTY;
587
588 spi_engine_tx_next(msg);
589 if (spi_engine_write_tx_fifo(spi_engine, msg))
590 int_enable |= SPI_ENGINE_INT_SDO_ALMOST_EMPTY;
591
592 spi_engine_rx_next(msg);
593 if (st->rx_length != 0)
594 int_enable |= SPI_ENGINE_INT_SDI_ALMOST_FULL;
595
596 int_enable |= SPI_ENGINE_INT_SYNC;
597
598 writel_relaxed(int_enable,
599 spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);
600 spi_engine->int_enable = int_enable;
601 spin_unlock_irqrestore(&spi_engine->lock, flags);
602
603 return 0;
604}
605
606static void spi_engine_timeout(struct timer_list *timer)
607{
608 struct spi_engine *spi_engine = from_timer(spi_engine, timer, watchdog_timer);
609 struct spi_controller *host = spi_engine->controller;
610
611 if (WARN_ON(!host->cur_msg))
612 return;
613
614 dev_err(&host->dev,
615 "Timeout occurred while waiting for transfer to complete. Hardware is probably broken.\n");
616 host->cur_msg->status = -ETIMEDOUT;
617 spi_finalize_current_message(host);
618}
619
620static void spi_engine_release_hw(void *p)
621{
622 struct spi_engine *spi_engine = p;
623
624 writel_relaxed(0xff, spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
625 writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);
626 writel_relaxed(0x01, spi_engine->base + SPI_ENGINE_REG_RESET);
627}
628
629static int spi_engine_probe(struct platform_device *pdev)
630{
631 struct spi_engine *spi_engine;
632 struct spi_controller *host;
633 unsigned int version;
634 int irq;
635 int ret;
636
637 irq = platform_get_irq(pdev, 0);
638 if (irq < 0)
639 return irq;
640
641 host = devm_spi_alloc_host(&pdev->dev, sizeof(*spi_engine));
642 if (!host)
643 return -ENOMEM;
644
645 spi_engine = spi_controller_get_devdata(host);
646
647 spin_lock_init(&spi_engine->lock);
648 ida_init(&spi_engine->sync_ida);
649 timer_setup(&spi_engine->watchdog_timer, spi_engine_timeout, TIMER_IRQSAFE);
650 spi_engine->controller = host;
651
652 spi_engine->clk = devm_clk_get_enabled(&pdev->dev, "s_axi_aclk");
653 if (IS_ERR(spi_engine->clk))
654 return PTR_ERR(spi_engine->clk);
655
656 spi_engine->ref_clk = devm_clk_get_enabled(&pdev->dev, "spi_clk");
657 if (IS_ERR(spi_engine->ref_clk))
658 return PTR_ERR(spi_engine->ref_clk);
659
660 spi_engine->base = devm_platform_ioremap_resource(pdev, 0);
661 if (IS_ERR(spi_engine->base))
662 return PTR_ERR(spi_engine->base);
663
664 version = readl(spi_engine->base + SPI_ENGINE_REG_VERSION);
665 if (SPI_ENGINE_VERSION_MAJOR(version) != 1) {
666 dev_err(&pdev->dev, "Unsupported peripheral version %u.%u.%c\n",
667 SPI_ENGINE_VERSION_MAJOR(version),
668 SPI_ENGINE_VERSION_MINOR(version),
669 SPI_ENGINE_VERSION_PATCH(version));
670 return -ENODEV;
671 }
672
673 writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_RESET);
674 writel_relaxed(0xff, spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
675 writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);
676
677 ret = devm_add_action_or_reset(&pdev->dev, spi_engine_release_hw,
678 spi_engine);
679 if (ret)
680 return ret;
681
682 ret = devm_request_irq(&pdev->dev, irq, spi_engine_irq, 0, pdev->name,
683 host);
684 if (ret)
685 return ret;
686
687 host->dev.of_node = pdev->dev.of_node;
688 host->mode_bits = SPI_CPOL | SPI_CPHA | SPI_3WIRE;
689 host->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);
690 host->max_speed_hz = clk_get_rate(spi_engine->ref_clk) / 2;
691 host->transfer_one_message = spi_engine_transfer_one_message;
692 host->prepare_message = spi_engine_prepare_message;
693 host->unprepare_message = spi_engine_unprepare_message;
694 host->num_chipselect = 8;
695
696 if (host->max_speed_hz == 0)
697 return dev_err_probe(&pdev->dev, -EINVAL, "spi_clk rate is 0");
698
699 ret = devm_spi_register_controller(&pdev->dev, host);
700 if (ret)
701 return ret;
702
703 platform_set_drvdata(pdev, host);
704
705 return 0;
706}
707
708static const struct of_device_id spi_engine_match_table[] = {
709 { .compatible = "adi,axi-spi-engine-1.00.a" },
710 { },
711};
712MODULE_DEVICE_TABLE(of, spi_engine_match_table);
713
714static struct platform_driver spi_engine_driver = {
715 .probe = spi_engine_probe,
716 .driver = {
717 .name = "spi-engine",
718 .of_match_table = spi_engine_match_table,
719 },
720};
721module_platform_driver(spi_engine_driver);
722
723MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
724MODULE_DESCRIPTION("Analog Devices SPI engine peripheral driver");
725MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * SPI-Engine SPI controller driver
4 * Copyright 2015 Analog Devices Inc.
5 * Author: Lars-Peter Clausen <lars@metafoo.de>
6 */
7
8#include <linux/clk.h>
9#include <linux/completion.h>
10#include <linux/fpga/adi-axi-common.h>
11#include <linux/interrupt.h>
12#include <linux/io.h>
13#include <linux/of.h>
14#include <linux/module.h>
15#include <linux/overflow.h>
16#include <linux/platform_device.h>
17#include <linux/spi/spi.h>
18
19#define SPI_ENGINE_REG_RESET 0x40
20
21#define SPI_ENGINE_REG_INT_ENABLE 0x80
22#define SPI_ENGINE_REG_INT_PENDING 0x84
23#define SPI_ENGINE_REG_INT_SOURCE 0x88
24
25#define SPI_ENGINE_REG_SYNC_ID 0xc0
26
27#define SPI_ENGINE_REG_CMD_FIFO_ROOM 0xd0
28#define SPI_ENGINE_REG_SDO_FIFO_ROOM 0xd4
29#define SPI_ENGINE_REG_SDI_FIFO_LEVEL 0xd8
30
31#define SPI_ENGINE_REG_CMD_FIFO 0xe0
32#define SPI_ENGINE_REG_SDO_DATA_FIFO 0xe4
33#define SPI_ENGINE_REG_SDI_DATA_FIFO 0xe8
34#define SPI_ENGINE_REG_SDI_DATA_FIFO_PEEK 0xec
35
36#define SPI_ENGINE_INT_CMD_ALMOST_EMPTY BIT(0)
37#define SPI_ENGINE_INT_SDO_ALMOST_EMPTY BIT(1)
38#define SPI_ENGINE_INT_SDI_ALMOST_FULL BIT(2)
39#define SPI_ENGINE_INT_SYNC BIT(3)
40
41#define SPI_ENGINE_CONFIG_CPHA BIT(0)
42#define SPI_ENGINE_CONFIG_CPOL BIT(1)
43#define SPI_ENGINE_CONFIG_3WIRE BIT(2)
44
45#define SPI_ENGINE_INST_TRANSFER 0x0
46#define SPI_ENGINE_INST_ASSERT 0x1
47#define SPI_ENGINE_INST_WRITE 0x2
48#define SPI_ENGINE_INST_MISC 0x3
49
50#define SPI_ENGINE_CMD_REG_CLK_DIV 0x0
51#define SPI_ENGINE_CMD_REG_CONFIG 0x1
52#define SPI_ENGINE_CMD_REG_XFER_BITS 0x2
53
54#define SPI_ENGINE_MISC_SYNC 0x0
55#define SPI_ENGINE_MISC_SLEEP 0x1
56
57#define SPI_ENGINE_TRANSFER_WRITE 0x1
58#define SPI_ENGINE_TRANSFER_READ 0x2
59
60/* Arbitrary sync ID for use by host->cur_msg */
61#define AXI_SPI_ENGINE_CUR_MSG_SYNC_ID 0x1
62
63#define SPI_ENGINE_CMD(inst, arg1, arg2) \
64 (((inst) << 12) | ((arg1) << 8) | (arg2))
65
66#define SPI_ENGINE_CMD_TRANSFER(flags, n) \
67 SPI_ENGINE_CMD(SPI_ENGINE_INST_TRANSFER, (flags), (n))
68#define SPI_ENGINE_CMD_ASSERT(delay, cs) \
69 SPI_ENGINE_CMD(SPI_ENGINE_INST_ASSERT, (delay), (cs))
70#define SPI_ENGINE_CMD_WRITE(reg, val) \
71 SPI_ENGINE_CMD(SPI_ENGINE_INST_WRITE, (reg), (val))
72#define SPI_ENGINE_CMD_SLEEP(delay) \
73 SPI_ENGINE_CMD(SPI_ENGINE_INST_MISC, SPI_ENGINE_MISC_SLEEP, (delay))
74#define SPI_ENGINE_CMD_SYNC(id) \
75 SPI_ENGINE_CMD(SPI_ENGINE_INST_MISC, SPI_ENGINE_MISC_SYNC, (id))
76
77struct spi_engine_program {
78 unsigned int length;
79 uint16_t instructions[] __counted_by(length);
80};
81
82/**
83 * struct spi_engine_message_state - SPI engine per-message state
84 */
85struct spi_engine_message_state {
86 /** @cmd_length: Number of elements in cmd_buf array. */
87 unsigned cmd_length;
88 /** @cmd_buf: Array of commands not yet written to CMD FIFO. */
89 const uint16_t *cmd_buf;
90 /** @tx_xfer: Next xfer with tx_buf not yet fully written to TX FIFO. */
91 struct spi_transfer *tx_xfer;
92 /** @tx_length: Size of tx_buf in bytes. */
93 unsigned int tx_length;
94 /** @tx_buf: Bytes not yet written to TX FIFO. */
95 const uint8_t *tx_buf;
96 /** @rx_xfer: Next xfer with rx_buf not yet fully written to RX FIFO. */
97 struct spi_transfer *rx_xfer;
98 /** @rx_length: Size of tx_buf in bytes. */
99 unsigned int rx_length;
100 /** @rx_buf: Bytes not yet written to the RX FIFO. */
101 uint8_t *rx_buf;
102};
103
104struct spi_engine {
105 struct clk *clk;
106 struct clk *ref_clk;
107
108 spinlock_t lock;
109
110 void __iomem *base;
111 struct spi_engine_message_state msg_state;
112 struct completion msg_complete;
113 unsigned int int_enable;
114};
115
116static void spi_engine_program_add_cmd(struct spi_engine_program *p,
117 bool dry, uint16_t cmd)
118{
119 p->length++;
120
121 if (!dry)
122 p->instructions[p->length - 1] = cmd;
123}
124
125static unsigned int spi_engine_get_config(struct spi_device *spi)
126{
127 unsigned int config = 0;
128
129 if (spi->mode & SPI_CPOL)
130 config |= SPI_ENGINE_CONFIG_CPOL;
131 if (spi->mode & SPI_CPHA)
132 config |= SPI_ENGINE_CONFIG_CPHA;
133 if (spi->mode & SPI_3WIRE)
134 config |= SPI_ENGINE_CONFIG_3WIRE;
135
136 return config;
137}
138
139static void spi_engine_gen_xfer(struct spi_engine_program *p, bool dry,
140 struct spi_transfer *xfer)
141{
142 unsigned int len;
143
144 if (xfer->bits_per_word <= 8)
145 len = xfer->len;
146 else if (xfer->bits_per_word <= 16)
147 len = xfer->len / 2;
148 else
149 len = xfer->len / 4;
150
151 while (len) {
152 unsigned int n = min(len, 256U);
153 unsigned int flags = 0;
154
155 if (xfer->tx_buf)
156 flags |= SPI_ENGINE_TRANSFER_WRITE;
157 if (xfer->rx_buf)
158 flags |= SPI_ENGINE_TRANSFER_READ;
159
160 spi_engine_program_add_cmd(p, dry,
161 SPI_ENGINE_CMD_TRANSFER(flags, n - 1));
162 len -= n;
163 }
164}
165
166static void spi_engine_gen_sleep(struct spi_engine_program *p, bool dry,
167 int delay_ns, u32 sclk_hz)
168{
169 unsigned int t;
170
171 /* negative delay indicates error, e.g. from spi_delay_to_ns() */
172 if (delay_ns <= 0)
173 return;
174
175 /* rounding down since executing the instruction adds a couple of ticks delay */
176 t = DIV_ROUND_DOWN_ULL((u64)delay_ns * sclk_hz, NSEC_PER_SEC);
177 while (t) {
178 unsigned int n = min(t, 256U);
179
180 spi_engine_program_add_cmd(p, dry, SPI_ENGINE_CMD_SLEEP(n - 1));
181 t -= n;
182 }
183}
184
185static void spi_engine_gen_cs(struct spi_engine_program *p, bool dry,
186 struct spi_device *spi, bool assert)
187{
188 unsigned int mask = 0xff;
189
190 if (assert)
191 mask ^= BIT(spi_get_chipselect(spi, 0));
192
193 spi_engine_program_add_cmd(p, dry, SPI_ENGINE_CMD_ASSERT(0, mask));
194}
195
196/*
197 * Performs precompile steps on the message.
198 *
199 * The SPI core does most of the message/transfer validation and filling in
200 * fields for us via __spi_validate(). This fixes up anything remaining not
201 * done there.
202 *
203 * NB: This is separate from spi_engine_compile_message() because the latter
204 * is called twice and would otherwise result in double-evaluation.
205 */
206static void spi_engine_precompile_message(struct spi_message *msg)
207{
208 unsigned int clk_div, max_hz = msg->spi->controller->max_speed_hz;
209 struct spi_transfer *xfer;
210
211 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
212 clk_div = DIV_ROUND_UP(max_hz, xfer->speed_hz);
213 xfer->effective_speed_hz = max_hz / min(clk_div, 256U);
214 }
215}
216
217static void spi_engine_compile_message(struct spi_message *msg, bool dry,
218 struct spi_engine_program *p)
219{
220 struct spi_device *spi = msg->spi;
221 struct spi_controller *host = spi->controller;
222 struct spi_transfer *xfer;
223 int clk_div, new_clk_div;
224 bool keep_cs = false;
225 u8 bits_per_word = 0;
226
227 clk_div = 1;
228
229 spi_engine_program_add_cmd(p, dry,
230 SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_CONFIG,
231 spi_engine_get_config(spi)));
232
233 xfer = list_first_entry(&msg->transfers, struct spi_transfer, transfer_list);
234 spi_engine_gen_cs(p, dry, spi, !xfer->cs_off);
235
236 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
237 new_clk_div = host->max_speed_hz / xfer->effective_speed_hz;
238 if (new_clk_div != clk_div) {
239 clk_div = new_clk_div;
240 /* actual divider used is register value + 1 */
241 spi_engine_program_add_cmd(p, dry,
242 SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_CLK_DIV,
243 clk_div - 1));
244 }
245
246 if (bits_per_word != xfer->bits_per_word) {
247 bits_per_word = xfer->bits_per_word;
248 spi_engine_program_add_cmd(p, dry,
249 SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_XFER_BITS,
250 bits_per_word));
251 }
252
253 spi_engine_gen_xfer(p, dry, xfer);
254 spi_engine_gen_sleep(p, dry, spi_delay_to_ns(&xfer->delay, xfer),
255 xfer->effective_speed_hz);
256
257 if (xfer->cs_change) {
258 if (list_is_last(&xfer->transfer_list, &msg->transfers)) {
259 keep_cs = true;
260 } else {
261 if (!xfer->cs_off)
262 spi_engine_gen_cs(p, dry, spi, false);
263
264 spi_engine_gen_sleep(p, dry, spi_delay_to_ns(
265 &xfer->cs_change_delay, xfer),
266 xfer->effective_speed_hz);
267
268 if (!list_next_entry(xfer, transfer_list)->cs_off)
269 spi_engine_gen_cs(p, dry, spi, true);
270 }
271 } else if (!list_is_last(&xfer->transfer_list, &msg->transfers) &&
272 xfer->cs_off != list_next_entry(xfer, transfer_list)->cs_off) {
273 spi_engine_gen_cs(p, dry, spi, xfer->cs_off);
274 }
275 }
276
277 if (!keep_cs)
278 spi_engine_gen_cs(p, dry, spi, false);
279
280 /*
281 * Restore clockdiv to default so that future gen_sleep commands don't
282 * have to be aware of the current register state.
283 */
284 if (clk_div != 1)
285 spi_engine_program_add_cmd(p, dry,
286 SPI_ENGINE_CMD_WRITE(SPI_ENGINE_CMD_REG_CLK_DIV, 0));
287}
288
289static void spi_engine_xfer_next(struct spi_message *msg,
290 struct spi_transfer **_xfer)
291{
292 struct spi_transfer *xfer = *_xfer;
293
294 if (!xfer) {
295 xfer = list_first_entry(&msg->transfers,
296 struct spi_transfer, transfer_list);
297 } else if (list_is_last(&xfer->transfer_list, &msg->transfers)) {
298 xfer = NULL;
299 } else {
300 xfer = list_next_entry(xfer, transfer_list);
301 }
302
303 *_xfer = xfer;
304}
305
306static void spi_engine_tx_next(struct spi_message *msg)
307{
308 struct spi_engine_message_state *st = msg->state;
309 struct spi_transfer *xfer = st->tx_xfer;
310
311 do {
312 spi_engine_xfer_next(msg, &xfer);
313 } while (xfer && !xfer->tx_buf);
314
315 st->tx_xfer = xfer;
316 if (xfer) {
317 st->tx_length = xfer->len;
318 st->tx_buf = xfer->tx_buf;
319 } else {
320 st->tx_buf = NULL;
321 }
322}
323
324static void spi_engine_rx_next(struct spi_message *msg)
325{
326 struct spi_engine_message_state *st = msg->state;
327 struct spi_transfer *xfer = st->rx_xfer;
328
329 do {
330 spi_engine_xfer_next(msg, &xfer);
331 } while (xfer && !xfer->rx_buf);
332
333 st->rx_xfer = xfer;
334 if (xfer) {
335 st->rx_length = xfer->len;
336 st->rx_buf = xfer->rx_buf;
337 } else {
338 st->rx_buf = NULL;
339 }
340}
341
342static bool spi_engine_write_cmd_fifo(struct spi_engine *spi_engine,
343 struct spi_message *msg)
344{
345 void __iomem *addr = spi_engine->base + SPI_ENGINE_REG_CMD_FIFO;
346 struct spi_engine_message_state *st = msg->state;
347 unsigned int n, m, i;
348 const uint16_t *buf;
349
350 n = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_CMD_FIFO_ROOM);
351 while (n && st->cmd_length) {
352 m = min(n, st->cmd_length);
353 buf = st->cmd_buf;
354 for (i = 0; i < m; i++)
355 writel_relaxed(buf[i], addr);
356 st->cmd_buf += m;
357 st->cmd_length -= m;
358 n -= m;
359 }
360
361 return st->cmd_length != 0;
362}
363
364static bool spi_engine_write_tx_fifo(struct spi_engine *spi_engine,
365 struct spi_message *msg)
366{
367 void __iomem *addr = spi_engine->base + SPI_ENGINE_REG_SDO_DATA_FIFO;
368 struct spi_engine_message_state *st = msg->state;
369 unsigned int n, m, i;
370
371 n = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_SDO_FIFO_ROOM);
372 while (n && st->tx_length) {
373 if (st->tx_xfer->bits_per_word <= 8) {
374 const u8 *buf = st->tx_buf;
375
376 m = min(n, st->tx_length);
377 for (i = 0; i < m; i++)
378 writel_relaxed(buf[i], addr);
379 st->tx_buf += m;
380 st->tx_length -= m;
381 } else if (st->tx_xfer->bits_per_word <= 16) {
382 const u16 *buf = (const u16 *)st->tx_buf;
383
384 m = min(n, st->tx_length / 2);
385 for (i = 0; i < m; i++)
386 writel_relaxed(buf[i], addr);
387 st->tx_buf += m * 2;
388 st->tx_length -= m * 2;
389 } else {
390 const u32 *buf = (const u32 *)st->tx_buf;
391
392 m = min(n, st->tx_length / 4);
393 for (i = 0; i < m; i++)
394 writel_relaxed(buf[i], addr);
395 st->tx_buf += m * 4;
396 st->tx_length -= m * 4;
397 }
398 n -= m;
399 if (st->tx_length == 0)
400 spi_engine_tx_next(msg);
401 }
402
403 return st->tx_length != 0;
404}
405
406static bool spi_engine_read_rx_fifo(struct spi_engine *spi_engine,
407 struct spi_message *msg)
408{
409 void __iomem *addr = spi_engine->base + SPI_ENGINE_REG_SDI_DATA_FIFO;
410 struct spi_engine_message_state *st = msg->state;
411 unsigned int n, m, i;
412
413 n = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_SDI_FIFO_LEVEL);
414 while (n && st->rx_length) {
415 if (st->rx_xfer->bits_per_word <= 8) {
416 u8 *buf = st->rx_buf;
417
418 m = min(n, st->rx_length);
419 for (i = 0; i < m; i++)
420 buf[i] = readl_relaxed(addr);
421 st->rx_buf += m;
422 st->rx_length -= m;
423 } else if (st->rx_xfer->bits_per_word <= 16) {
424 u16 *buf = (u16 *)st->rx_buf;
425
426 m = min(n, st->rx_length / 2);
427 for (i = 0; i < m; i++)
428 buf[i] = readl_relaxed(addr);
429 st->rx_buf += m * 2;
430 st->rx_length -= m * 2;
431 } else {
432 u32 *buf = (u32 *)st->rx_buf;
433
434 m = min(n, st->rx_length / 4);
435 for (i = 0; i < m; i++)
436 buf[i] = readl_relaxed(addr);
437 st->rx_buf += m * 4;
438 st->rx_length -= m * 4;
439 }
440 n -= m;
441 if (st->rx_length == 0)
442 spi_engine_rx_next(msg);
443 }
444
445 return st->rx_length != 0;
446}
447
448static irqreturn_t spi_engine_irq(int irq, void *devid)
449{
450 struct spi_controller *host = devid;
451 struct spi_message *msg = host->cur_msg;
452 struct spi_engine *spi_engine = spi_controller_get_devdata(host);
453 unsigned int disable_int = 0;
454 unsigned int pending;
455 int completed_id = -1;
456
457 pending = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
458
459 if (pending & SPI_ENGINE_INT_SYNC) {
460 writel_relaxed(SPI_ENGINE_INT_SYNC,
461 spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
462 completed_id = readl_relaxed(
463 spi_engine->base + SPI_ENGINE_REG_SYNC_ID);
464 }
465
466 spin_lock(&spi_engine->lock);
467
468 if (pending & SPI_ENGINE_INT_CMD_ALMOST_EMPTY) {
469 if (!spi_engine_write_cmd_fifo(spi_engine, msg))
470 disable_int |= SPI_ENGINE_INT_CMD_ALMOST_EMPTY;
471 }
472
473 if (pending & SPI_ENGINE_INT_SDO_ALMOST_EMPTY) {
474 if (!spi_engine_write_tx_fifo(spi_engine, msg))
475 disable_int |= SPI_ENGINE_INT_SDO_ALMOST_EMPTY;
476 }
477
478 if (pending & (SPI_ENGINE_INT_SDI_ALMOST_FULL | SPI_ENGINE_INT_SYNC)) {
479 if (!spi_engine_read_rx_fifo(spi_engine, msg))
480 disable_int |= SPI_ENGINE_INT_SDI_ALMOST_FULL;
481 }
482
483 if (pending & SPI_ENGINE_INT_SYNC && msg) {
484 if (completed_id == AXI_SPI_ENGINE_CUR_MSG_SYNC_ID) {
485 msg->status = 0;
486 msg->actual_length = msg->frame_length;
487 complete(&spi_engine->msg_complete);
488 disable_int |= SPI_ENGINE_INT_SYNC;
489 }
490 }
491
492 if (disable_int) {
493 spi_engine->int_enable &= ~disable_int;
494 writel_relaxed(spi_engine->int_enable,
495 spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);
496 }
497
498 spin_unlock(&spi_engine->lock);
499
500 return IRQ_HANDLED;
501}
502
503static int spi_engine_optimize_message(struct spi_message *msg)
504{
505 struct spi_engine_program p_dry, *p;
506
507 spi_engine_precompile_message(msg);
508
509 p_dry.length = 0;
510 spi_engine_compile_message(msg, true, &p_dry);
511
512 p = kzalloc(struct_size(p, instructions, p_dry.length + 1), GFP_KERNEL);
513 if (!p)
514 return -ENOMEM;
515
516 spi_engine_compile_message(msg, false, p);
517
518 spi_engine_program_add_cmd(p, false, SPI_ENGINE_CMD_SYNC(
519 AXI_SPI_ENGINE_CUR_MSG_SYNC_ID));
520
521 msg->opt_state = p;
522
523 return 0;
524}
525
526static int spi_engine_unoptimize_message(struct spi_message *msg)
527{
528 kfree(msg->opt_state);
529
530 return 0;
531}
532
533static int spi_engine_transfer_one_message(struct spi_controller *host,
534 struct spi_message *msg)
535{
536 struct spi_engine *spi_engine = spi_controller_get_devdata(host);
537 struct spi_engine_message_state *st = &spi_engine->msg_state;
538 struct spi_engine_program *p = msg->opt_state;
539 unsigned int int_enable = 0;
540 unsigned long flags;
541
542 /* reinitialize message state for this transfer */
543 memset(st, 0, sizeof(*st));
544 st->cmd_buf = p->instructions;
545 st->cmd_length = p->length;
546 msg->state = st;
547
548 reinit_completion(&spi_engine->msg_complete);
549
550 spin_lock_irqsave(&spi_engine->lock, flags);
551
552 if (spi_engine_write_cmd_fifo(spi_engine, msg))
553 int_enable |= SPI_ENGINE_INT_CMD_ALMOST_EMPTY;
554
555 spi_engine_tx_next(msg);
556 if (spi_engine_write_tx_fifo(spi_engine, msg))
557 int_enable |= SPI_ENGINE_INT_SDO_ALMOST_EMPTY;
558
559 spi_engine_rx_next(msg);
560 if (st->rx_length != 0)
561 int_enable |= SPI_ENGINE_INT_SDI_ALMOST_FULL;
562
563 int_enable |= SPI_ENGINE_INT_SYNC;
564
565 writel_relaxed(int_enable,
566 spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);
567 spi_engine->int_enable = int_enable;
568 spin_unlock_irqrestore(&spi_engine->lock, flags);
569
570 if (!wait_for_completion_timeout(&spi_engine->msg_complete,
571 msecs_to_jiffies(5000))) {
572 dev_err(&host->dev,
573 "Timeout occurred while waiting for transfer to complete. Hardware is probably broken.\n");
574 msg->status = -ETIMEDOUT;
575 }
576
577 spi_finalize_current_message(host);
578
579 return msg->status;
580}
581
582static void spi_engine_release_hw(void *p)
583{
584 struct spi_engine *spi_engine = p;
585
586 writel_relaxed(0xff, spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
587 writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);
588 writel_relaxed(0x01, spi_engine->base + SPI_ENGINE_REG_RESET);
589}
590
591static int spi_engine_probe(struct platform_device *pdev)
592{
593 struct spi_engine *spi_engine;
594 struct spi_controller *host;
595 unsigned int version;
596 int irq;
597 int ret;
598
599 irq = platform_get_irq(pdev, 0);
600 if (irq < 0)
601 return irq;
602
603 host = devm_spi_alloc_host(&pdev->dev, sizeof(*spi_engine));
604 if (!host)
605 return -ENOMEM;
606
607 spi_engine = spi_controller_get_devdata(host);
608
609 spin_lock_init(&spi_engine->lock);
610 init_completion(&spi_engine->msg_complete);
611
612 spi_engine->clk = devm_clk_get_enabled(&pdev->dev, "s_axi_aclk");
613 if (IS_ERR(spi_engine->clk))
614 return PTR_ERR(spi_engine->clk);
615
616 spi_engine->ref_clk = devm_clk_get_enabled(&pdev->dev, "spi_clk");
617 if (IS_ERR(spi_engine->ref_clk))
618 return PTR_ERR(spi_engine->ref_clk);
619
620 spi_engine->base = devm_platform_ioremap_resource(pdev, 0);
621 if (IS_ERR(spi_engine->base))
622 return PTR_ERR(spi_engine->base);
623
624 version = readl(spi_engine->base + ADI_AXI_REG_VERSION);
625 if (ADI_AXI_PCORE_VER_MAJOR(version) != 1) {
626 dev_err(&pdev->dev, "Unsupported peripheral version %u.%u.%u\n",
627 ADI_AXI_PCORE_VER_MAJOR(version),
628 ADI_AXI_PCORE_VER_MINOR(version),
629 ADI_AXI_PCORE_VER_PATCH(version));
630 return -ENODEV;
631 }
632
633 writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_RESET);
634 writel_relaxed(0xff, spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
635 writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);
636
637 ret = devm_add_action_or_reset(&pdev->dev, spi_engine_release_hw,
638 spi_engine);
639 if (ret)
640 return ret;
641
642 ret = devm_request_irq(&pdev->dev, irq, spi_engine_irq, 0, pdev->name,
643 host);
644 if (ret)
645 return ret;
646
647 host->dev.of_node = pdev->dev.of_node;
648 host->mode_bits = SPI_CPOL | SPI_CPHA | SPI_3WIRE;
649 host->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);
650 host->max_speed_hz = clk_get_rate(spi_engine->ref_clk) / 2;
651 host->transfer_one_message = spi_engine_transfer_one_message;
652 host->optimize_message = spi_engine_optimize_message;
653 host->unoptimize_message = spi_engine_unoptimize_message;
654 host->num_chipselect = 8;
655
656 if (host->max_speed_hz == 0)
657 return dev_err_probe(&pdev->dev, -EINVAL, "spi_clk rate is 0");
658
659 ret = devm_spi_register_controller(&pdev->dev, host);
660 if (ret)
661 return ret;
662
663 platform_set_drvdata(pdev, host);
664
665 return 0;
666}
667
668static const struct of_device_id spi_engine_match_table[] = {
669 { .compatible = "adi,axi-spi-engine-1.00.a" },
670 { },
671};
672MODULE_DEVICE_TABLE(of, spi_engine_match_table);
673
674static struct platform_driver spi_engine_driver = {
675 .probe = spi_engine_probe,
676 .driver = {
677 .name = "spi-engine",
678 .of_match_table = spi_engine_match_table,
679 },
680};
681module_platform_driver(spi_engine_driver);
682
683MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
684MODULE_DESCRIPTION("Analog Devices SPI engine peripheral driver");
685MODULE_LICENSE("GPL");