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.%c\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");
686