1 // SPDX-License-Identifier: GPL-2.0-or-later
2 // Copyright (C) IBM Corporation 2020
3 
4 #include <linux/bitfield.h>
5 #include <linux/bits.h>
6 #include <linux/fsi.h>
7 #include <linux/jiffies.h>
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/of.h>
11 #include <linux/spi/spi.h>
12 
13 #define FSI_ENGID_SPI			0x23
14 #define FSI_MBOX_ROOT_CTRL_8		0x2860
15 #define  FSI_MBOX_ROOT_CTRL_8_SPI_MUX	 0xf0000000
16 
17 #define FSI2SPI_DATA0			0x00
18 #define FSI2SPI_DATA1			0x04
19 #define FSI2SPI_CMD			0x08
20 #define  FSI2SPI_CMD_WRITE		 BIT(31)
21 #define FSI2SPI_RESET			0x18
22 #define FSI2SPI_STATUS			0x1c
23 #define  FSI2SPI_STATUS_ANY_ERROR	 BIT(31)
24 #define FSI2SPI_IRQ			0x20
25 
26 #define SPI_FSI_BASE			0x70000
27 #define SPI_FSI_INIT_TIMEOUT_MS		1000
28 #define SPI_FSI_MAX_XFR_SIZE		2048
29 #define SPI_FSI_MAX_XFR_SIZE_RESTRICTED	8
30 
31 #define SPI_FSI_ERROR			0x0
32 #define SPI_FSI_COUNTER_CFG		0x1
33 #define  SPI_FSI_COUNTER_CFG_LOOPS(x)	 (((u64)(x) & 0xffULL) << 32)
34 #define  SPI_FSI_COUNTER_CFG_N2_RX	 BIT_ULL(8)
35 #define  SPI_FSI_COUNTER_CFG_N2_TX	 BIT_ULL(9)
36 #define  SPI_FSI_COUNTER_CFG_N2_IMPLICIT BIT_ULL(10)
37 #define  SPI_FSI_COUNTER_CFG_N2_RELOAD	 BIT_ULL(11)
38 #define SPI_FSI_CFG1			0x2
39 #define SPI_FSI_CLOCK_CFG		0x3
40 #define  SPI_FSI_CLOCK_CFG_MM_ENABLE	 BIT_ULL(32)
41 #define  SPI_FSI_CLOCK_CFG_ECC_DISABLE	 (BIT_ULL(35) | BIT_ULL(33))
42 #define  SPI_FSI_CLOCK_CFG_RESET1	 (BIT_ULL(36) | BIT_ULL(38))
43 #define  SPI_FSI_CLOCK_CFG_RESET2	 (BIT_ULL(37) | BIT_ULL(39))
44 #define  SPI_FSI_CLOCK_CFG_MODE		 (BIT_ULL(41) | BIT_ULL(42))
45 #define  SPI_FSI_CLOCK_CFG_SCK_RECV_DEL	 GENMASK_ULL(51, 44)
46 #define   SPI_FSI_CLOCK_CFG_SCK_NO_DEL	  BIT_ULL(51)
47 #define  SPI_FSI_CLOCK_CFG_SCK_DIV	 GENMASK_ULL(63, 52)
48 #define SPI_FSI_MMAP			0x4
49 #define SPI_FSI_DATA_TX			0x5
50 #define SPI_FSI_DATA_RX			0x6
51 #define SPI_FSI_SEQUENCE		0x7
52 #define  SPI_FSI_SEQUENCE_STOP		 0x00
53 #define  SPI_FSI_SEQUENCE_SEL_SLAVE(x)	 (0x10 | ((x) & 0xf))
54 #define  SPI_FSI_SEQUENCE_SHIFT_OUT(x)	 (0x30 | ((x) & 0xf))
55 #define  SPI_FSI_SEQUENCE_SHIFT_IN(x)	 (0x40 | ((x) & 0xf))
56 #define  SPI_FSI_SEQUENCE_COPY_DATA_TX	 0xc0
57 #define  SPI_FSI_SEQUENCE_BRANCH(x)	 (0xe0 | ((x) & 0xf))
58 #define SPI_FSI_STATUS			0x8
59 #define  SPI_FSI_STATUS_ERROR		 \
60 	(GENMASK_ULL(31, 21) | GENMASK_ULL(15, 12))
61 #define  SPI_FSI_STATUS_SEQ_STATE	 GENMASK_ULL(55, 48)
62 #define   SPI_FSI_STATUS_SEQ_STATE_IDLE	  BIT_ULL(48)
63 #define  SPI_FSI_STATUS_TDR_UNDERRUN	 BIT_ULL(57)
64 #define  SPI_FSI_STATUS_TDR_OVERRUN	 BIT_ULL(58)
65 #define  SPI_FSI_STATUS_TDR_FULL	 BIT_ULL(59)
66 #define  SPI_FSI_STATUS_RDR_UNDERRUN	 BIT_ULL(61)
67 #define  SPI_FSI_STATUS_RDR_OVERRUN	 BIT_ULL(62)
68 #define  SPI_FSI_STATUS_RDR_FULL	 BIT_ULL(63)
69 #define  SPI_FSI_STATUS_ANY_ERROR	 \
70 	(SPI_FSI_STATUS_ERROR | \
71 	 SPI_FSI_STATUS_TDR_OVERRUN | SPI_FSI_STATUS_RDR_UNDERRUN | \
72 	 SPI_FSI_STATUS_RDR_OVERRUN)
73 #define SPI_FSI_PORT_CTRL		0x9
74 
75 struct fsi_spi {
76 	struct device *dev;	/* SPI controller device */
77 	struct fsi_device *fsi;	/* FSI2SPI CFAM engine device */
78 	u32 base;
79 	size_t max_xfr_size;
80 	bool restricted;
81 };
82 
83 struct fsi_spi_sequence {
84 	int bit;
85 	u64 data;
86 };
87 
fsi_spi_check_mux(struct fsi_device * fsi,struct device * dev)88 static int fsi_spi_check_mux(struct fsi_device *fsi, struct device *dev)
89 {
90 	int rc;
91 	u32 root_ctrl_8;
92 	__be32 root_ctrl_8_be;
93 
94 	rc = fsi_slave_read(fsi->slave, FSI_MBOX_ROOT_CTRL_8, &root_ctrl_8_be,
95 			    sizeof(root_ctrl_8_be));
96 	if (rc)
97 		return rc;
98 
99 	root_ctrl_8 = be32_to_cpu(root_ctrl_8_be);
100 	dev_dbg(dev, "Root control register 8: %08x\n", root_ctrl_8);
101 	if ((root_ctrl_8 & FSI_MBOX_ROOT_CTRL_8_SPI_MUX) ==
102 	     FSI_MBOX_ROOT_CTRL_8_SPI_MUX)
103 		return 0;
104 
105 	return -ENOLINK;
106 }
107 
fsi_spi_check_status(struct fsi_spi * ctx)108 static int fsi_spi_check_status(struct fsi_spi *ctx)
109 {
110 	int rc;
111 	u32 sts;
112 	__be32 sts_be;
113 
114 	rc = fsi_device_read(ctx->fsi, FSI2SPI_STATUS, &sts_be,
115 			     sizeof(sts_be));
116 	if (rc)
117 		return rc;
118 
119 	sts = be32_to_cpu(sts_be);
120 	if (sts & FSI2SPI_STATUS_ANY_ERROR) {
121 		dev_err(ctx->dev, "Error with FSI2SPI interface: %08x.\n", sts);
122 		return -EIO;
123 	}
124 
125 	return 0;
126 }
127 
fsi_spi_read_reg(struct fsi_spi * ctx,u32 offset,u64 * value)128 static int fsi_spi_read_reg(struct fsi_spi *ctx, u32 offset, u64 *value)
129 {
130 	int rc;
131 	__be32 cmd_be;
132 	__be32 data_be;
133 	u32 cmd = offset + ctx->base;
134 
135 	*value = 0ULL;
136 
137 	if (cmd & FSI2SPI_CMD_WRITE)
138 		return -EINVAL;
139 
140 	cmd_be = cpu_to_be32(cmd);
141 	rc = fsi_device_write(ctx->fsi, FSI2SPI_CMD, &cmd_be, sizeof(cmd_be));
142 	if (rc)
143 		return rc;
144 
145 	rc = fsi_spi_check_status(ctx);
146 	if (rc)
147 		return rc;
148 
149 	rc = fsi_device_read(ctx->fsi, FSI2SPI_DATA0, &data_be,
150 			     sizeof(data_be));
151 	if (rc)
152 		return rc;
153 
154 	*value |= (u64)be32_to_cpu(data_be) << 32;
155 
156 	rc = fsi_device_read(ctx->fsi, FSI2SPI_DATA1, &data_be,
157 			     sizeof(data_be));
158 	if (rc)
159 		return rc;
160 
161 	*value |= (u64)be32_to_cpu(data_be);
162 	dev_dbg(ctx->dev, "Read %02x[%016llx].\n", offset, *value);
163 
164 	return 0;
165 }
166 
fsi_spi_write_reg(struct fsi_spi * ctx,u32 offset,u64 value)167 static int fsi_spi_write_reg(struct fsi_spi *ctx, u32 offset, u64 value)
168 {
169 	int rc;
170 	__be32 cmd_be;
171 	__be32 data_be;
172 	u32 cmd = offset + ctx->base;
173 
174 	if (cmd & FSI2SPI_CMD_WRITE)
175 		return -EINVAL;
176 
177 	dev_dbg(ctx->dev, "Write %02x[%016llx].\n", offset, value);
178 
179 	data_be = cpu_to_be32(upper_32_bits(value));
180 	rc = fsi_device_write(ctx->fsi, FSI2SPI_DATA0, &data_be,
181 			      sizeof(data_be));
182 	if (rc)
183 		return rc;
184 
185 	data_be = cpu_to_be32(lower_32_bits(value));
186 	rc = fsi_device_write(ctx->fsi, FSI2SPI_DATA1, &data_be,
187 			      sizeof(data_be));
188 	if (rc)
189 		return rc;
190 
191 	cmd_be = cpu_to_be32(cmd | FSI2SPI_CMD_WRITE);
192 	rc = fsi_device_write(ctx->fsi, FSI2SPI_CMD, &cmd_be, sizeof(cmd_be));
193 	if (rc)
194 		return rc;
195 
196 	return fsi_spi_check_status(ctx);
197 }
198 
fsi_spi_data_in(u64 in,u8 * rx,int len)199 static int fsi_spi_data_in(u64 in, u8 *rx, int len)
200 {
201 	int i;
202 	int num_bytes = min(len, 8);
203 
204 	for (i = 0; i < num_bytes; ++i)
205 		rx[i] = (u8)(in >> (8 * ((num_bytes - 1) - i)));
206 
207 	return num_bytes;
208 }
209 
fsi_spi_data_out(u64 * out,const u8 * tx,int len)210 static int fsi_spi_data_out(u64 *out, const u8 *tx, int len)
211 {
212 	int i;
213 	int num_bytes = min(len, 8);
214 	u8 *out_bytes = (u8 *)out;
215 
216 	/* Unused bytes of the tx data should be 0. */
217 	*out = 0ULL;
218 
219 	for (i = 0; i < num_bytes; ++i)
220 		out_bytes[8 - (i + 1)] = tx[i];
221 
222 	return num_bytes;
223 }
224 
fsi_spi_reset(struct fsi_spi * ctx)225 static int fsi_spi_reset(struct fsi_spi *ctx)
226 {
227 	int rc;
228 
229 	dev_dbg(ctx->dev, "Resetting SPI controller.\n");
230 
231 	rc = fsi_spi_write_reg(ctx, SPI_FSI_CLOCK_CFG,
232 			       SPI_FSI_CLOCK_CFG_RESET1);
233 	if (rc)
234 		return rc;
235 
236 	rc = fsi_spi_write_reg(ctx, SPI_FSI_CLOCK_CFG,
237 			       SPI_FSI_CLOCK_CFG_RESET2);
238 	if (rc)
239 		return rc;
240 
241 	return fsi_spi_write_reg(ctx, SPI_FSI_STATUS, 0ULL);
242 }
243 
fsi_spi_sequence_add(struct fsi_spi_sequence * seq,u8 val)244 static int fsi_spi_sequence_add(struct fsi_spi_sequence *seq, u8 val)
245 {
246 	/*
247 	 * Add the next byte of instruction to the 8-byte sequence register.
248 	 * Then decrement the counter so that the next instruction will go in
249 	 * the right place. Return the index of the slot we just filled in the
250 	 * sequence register.
251 	 */
252 	seq->data |= (u64)val << seq->bit;
253 	seq->bit -= 8;
254 
255 	return ((64 - seq->bit) / 8) - 2;
256 }
257 
fsi_spi_sequence_init(struct fsi_spi_sequence * seq)258 static void fsi_spi_sequence_init(struct fsi_spi_sequence *seq)
259 {
260 	seq->bit = 56;
261 	seq->data = 0ULL;
262 }
263 
fsi_spi_sequence_transfer(struct fsi_spi * ctx,struct fsi_spi_sequence * seq,struct spi_transfer * transfer)264 static int fsi_spi_sequence_transfer(struct fsi_spi *ctx,
265 				     struct fsi_spi_sequence *seq,
266 				     struct spi_transfer *transfer)
267 {
268 	int loops;
269 	int idx;
270 	int rc;
271 	u8 val = 0;
272 	u8 len = min(transfer->len, 8U);
273 	u8 rem = transfer->len % len;
274 
275 	loops = transfer->len / len;
276 
277 	if (transfer->tx_buf) {
278 		val = SPI_FSI_SEQUENCE_SHIFT_OUT(len);
279 		idx = fsi_spi_sequence_add(seq, val);
280 
281 		if (rem)
282 			rem = SPI_FSI_SEQUENCE_SHIFT_OUT(rem);
283 	} else if (transfer->rx_buf) {
284 		val = SPI_FSI_SEQUENCE_SHIFT_IN(len);
285 		idx = fsi_spi_sequence_add(seq, val);
286 
287 		if (rem)
288 			rem = SPI_FSI_SEQUENCE_SHIFT_IN(rem);
289 	} else {
290 		return -EINVAL;
291 	}
292 
293 	if (ctx->restricted && loops > 1) {
294 		dev_warn(ctx->dev,
295 			 "Transfer too large; no branches permitted.\n");
296 		return -EINVAL;
297 	}
298 
299 	if (loops > 1) {
300 		u64 cfg = SPI_FSI_COUNTER_CFG_LOOPS(loops - 1);
301 
302 		fsi_spi_sequence_add(seq, SPI_FSI_SEQUENCE_BRANCH(idx));
303 
304 		if (transfer->rx_buf)
305 			cfg |= SPI_FSI_COUNTER_CFG_N2_RX |
306 				SPI_FSI_COUNTER_CFG_N2_TX |
307 				SPI_FSI_COUNTER_CFG_N2_IMPLICIT |
308 				SPI_FSI_COUNTER_CFG_N2_RELOAD;
309 
310 		rc = fsi_spi_write_reg(ctx, SPI_FSI_COUNTER_CFG, cfg);
311 		if (rc)
312 			return rc;
313 	} else {
314 		fsi_spi_write_reg(ctx, SPI_FSI_COUNTER_CFG, 0ULL);
315 	}
316 
317 	if (rem)
318 		fsi_spi_sequence_add(seq, rem);
319 
320 	return 0;
321 }
322 
fsi_spi_transfer_data(struct fsi_spi * ctx,struct spi_transfer * transfer)323 static int fsi_spi_transfer_data(struct fsi_spi *ctx,
324 				 struct spi_transfer *transfer)
325 {
326 	int rc = 0;
327 	u64 status = 0ULL;
328 	u64 cfg = 0ULL;
329 
330 	if (transfer->tx_buf) {
331 		int nb;
332 		int sent = 0;
333 		u64 out = 0ULL;
334 		const u8 *tx = transfer->tx_buf;
335 
336 		while (transfer->len > sent) {
337 			nb = fsi_spi_data_out(&out, &tx[sent],
338 					      (int)transfer->len - sent);
339 
340 			rc = fsi_spi_write_reg(ctx, SPI_FSI_DATA_TX, out);
341 			if (rc)
342 				return rc;
343 
344 			do {
345 				rc = fsi_spi_read_reg(ctx, SPI_FSI_STATUS,
346 						      &status);
347 				if (rc)
348 					return rc;
349 
350 				if (status & SPI_FSI_STATUS_ANY_ERROR) {
351 					rc = fsi_spi_reset(ctx);
352 					if (rc)
353 						return rc;
354 
355 					return -EREMOTEIO;
356 				}
357 			} while (status & SPI_FSI_STATUS_TDR_FULL);
358 
359 			sent += nb;
360 		}
361 	} else if (transfer->rx_buf) {
362 		int recv = 0;
363 		u64 in = 0ULL;
364 		u8 *rx = transfer->rx_buf;
365 
366 		rc = fsi_spi_read_reg(ctx, SPI_FSI_COUNTER_CFG, &cfg);
367 		if (rc)
368 			return rc;
369 
370 		if (cfg & SPI_FSI_COUNTER_CFG_N2_IMPLICIT) {
371 			rc = fsi_spi_write_reg(ctx, SPI_FSI_DATA_TX, 0);
372 			if (rc)
373 				return rc;
374 		}
375 
376 		while (transfer->len > recv) {
377 			do {
378 				rc = fsi_spi_read_reg(ctx, SPI_FSI_STATUS,
379 						      &status);
380 				if (rc)
381 					return rc;
382 
383 				if (status & SPI_FSI_STATUS_ANY_ERROR) {
384 					rc = fsi_spi_reset(ctx);
385 					if (rc)
386 						return rc;
387 
388 					return -EREMOTEIO;
389 				}
390 			} while (!(status & SPI_FSI_STATUS_RDR_FULL));
391 
392 			rc = fsi_spi_read_reg(ctx, SPI_FSI_DATA_RX, &in);
393 			if (rc)
394 				return rc;
395 
396 			recv += fsi_spi_data_in(in, &rx[recv],
397 						(int)transfer->len - recv);
398 		}
399 	}
400 
401 	return 0;
402 }
403 
fsi_spi_transfer_init(struct fsi_spi * ctx)404 static int fsi_spi_transfer_init(struct fsi_spi *ctx)
405 {
406 	int rc;
407 	bool reset = false;
408 	unsigned long end;
409 	u64 seq_state;
410 	u64 clock_cfg = 0ULL;
411 	u64 status = 0ULL;
412 	u64 wanted_clock_cfg = SPI_FSI_CLOCK_CFG_ECC_DISABLE |
413 		SPI_FSI_CLOCK_CFG_SCK_NO_DEL |
414 		FIELD_PREP(SPI_FSI_CLOCK_CFG_SCK_DIV, 19);
415 
416 	end = jiffies + msecs_to_jiffies(SPI_FSI_INIT_TIMEOUT_MS);
417 	do {
418 		if (time_after(jiffies, end))
419 			return -ETIMEDOUT;
420 
421 		rc = fsi_spi_read_reg(ctx, SPI_FSI_STATUS, &status);
422 		if (rc)
423 			return rc;
424 
425 		seq_state = status & SPI_FSI_STATUS_SEQ_STATE;
426 
427 		if (status & (SPI_FSI_STATUS_ANY_ERROR |
428 			      SPI_FSI_STATUS_TDR_FULL |
429 			      SPI_FSI_STATUS_RDR_FULL)) {
430 			if (reset)
431 				return -EIO;
432 
433 			rc = fsi_spi_reset(ctx);
434 			if (rc)
435 				return rc;
436 
437 			reset = true;
438 			continue;
439 		}
440 	} while (seq_state && (seq_state != SPI_FSI_STATUS_SEQ_STATE_IDLE));
441 
442 	rc = fsi_spi_read_reg(ctx, SPI_FSI_CLOCK_CFG, &clock_cfg);
443 	if (rc)
444 		return rc;
445 
446 	if ((clock_cfg & (SPI_FSI_CLOCK_CFG_MM_ENABLE |
447 			  SPI_FSI_CLOCK_CFG_ECC_DISABLE |
448 			  SPI_FSI_CLOCK_CFG_MODE |
449 			  SPI_FSI_CLOCK_CFG_SCK_RECV_DEL |
450 			  SPI_FSI_CLOCK_CFG_SCK_DIV)) != wanted_clock_cfg)
451 		rc = fsi_spi_write_reg(ctx, SPI_FSI_CLOCK_CFG,
452 				       wanted_clock_cfg);
453 
454 	return rc;
455 }
456 
fsi_spi_transfer_one_message(struct spi_controller * ctlr,struct spi_message * mesg)457 static int fsi_spi_transfer_one_message(struct spi_controller *ctlr,
458 					struct spi_message *mesg)
459 {
460 	int rc;
461 	u8 seq_slave = SPI_FSI_SEQUENCE_SEL_SLAVE(mesg->spi->chip_select + 1);
462 	struct spi_transfer *transfer;
463 	struct fsi_spi *ctx = spi_controller_get_devdata(ctlr);
464 
465 	rc = fsi_spi_check_mux(ctx->fsi, ctx->dev);
466 	if (rc)
467 		goto error;
468 
469 	list_for_each_entry(transfer, &mesg->transfers, transfer_list) {
470 		struct fsi_spi_sequence seq;
471 		struct spi_transfer *next = NULL;
472 
473 		/* Sequencer must do shift out (tx) first. */
474 		if (!transfer->tx_buf ||
475 		    transfer->len > (ctx->max_xfr_size + 8)) {
476 			rc = -EINVAL;
477 			goto error;
478 		}
479 
480 		dev_dbg(ctx->dev, "Start tx of %d bytes.\n", transfer->len);
481 
482 		rc = fsi_spi_transfer_init(ctx);
483 		if (rc < 0)
484 			goto error;
485 
486 		fsi_spi_sequence_init(&seq);
487 		fsi_spi_sequence_add(&seq, seq_slave);
488 
489 		rc = fsi_spi_sequence_transfer(ctx, &seq, transfer);
490 		if (rc)
491 			goto error;
492 
493 		if (!list_is_last(&transfer->transfer_list,
494 				  &mesg->transfers)) {
495 			next = list_next_entry(transfer, transfer_list);
496 
497 			/* Sequencer can only do shift in (rx) after tx. */
498 			if (next->rx_buf) {
499 				if (next->len > ctx->max_xfr_size) {
500 					rc = -EINVAL;
501 					goto error;
502 				}
503 
504 				dev_dbg(ctx->dev, "Sequence rx of %d bytes.\n",
505 					next->len);
506 
507 				rc = fsi_spi_sequence_transfer(ctx, &seq,
508 							       next);
509 				if (rc)
510 					goto error;
511 			} else {
512 				next = NULL;
513 			}
514 		}
515 
516 		fsi_spi_sequence_add(&seq, SPI_FSI_SEQUENCE_SEL_SLAVE(0));
517 
518 		rc = fsi_spi_write_reg(ctx, SPI_FSI_SEQUENCE, seq.data);
519 		if (rc)
520 			goto error;
521 
522 		rc = fsi_spi_transfer_data(ctx, transfer);
523 		if (rc)
524 			goto error;
525 
526 		if (next) {
527 			rc = fsi_spi_transfer_data(ctx, next);
528 			if (rc)
529 				goto error;
530 
531 			transfer = next;
532 		}
533 	}
534 
535 error:
536 	mesg->status = rc;
537 	spi_finalize_current_message(ctlr);
538 
539 	return rc;
540 }
541 
fsi_spi_max_transfer_size(struct spi_device * spi)542 static size_t fsi_spi_max_transfer_size(struct spi_device *spi)
543 {
544 	struct fsi_spi *ctx = spi_controller_get_devdata(spi->controller);
545 
546 	return ctx->max_xfr_size;
547 }
548 
fsi_spi_probe(struct device * dev)549 static int fsi_spi_probe(struct device *dev)
550 {
551 	int rc;
552 	struct device_node *np;
553 	int num_controllers_registered = 0;
554 	struct fsi_device *fsi = to_fsi_dev(dev);
555 
556 	rc = fsi_spi_check_mux(fsi, dev);
557 	if (rc)
558 		return -ENODEV;
559 
560 	for_each_available_child_of_node(dev->of_node, np) {
561 		u32 base;
562 		struct fsi_spi *ctx;
563 		struct spi_controller *ctlr;
564 
565 		if (of_property_read_u32(np, "reg", &base))
566 			continue;
567 
568 		ctlr = spi_alloc_master(dev, sizeof(*ctx));
569 		if (!ctlr) {
570 			of_node_put(np);
571 			break;
572 		}
573 
574 		ctlr->dev.of_node = np;
575 		ctlr->num_chipselect = of_get_available_child_count(np) ?: 1;
576 		ctlr->flags = SPI_CONTROLLER_HALF_DUPLEX;
577 		ctlr->max_transfer_size = fsi_spi_max_transfer_size;
578 		ctlr->transfer_one_message = fsi_spi_transfer_one_message;
579 
580 		ctx = spi_controller_get_devdata(ctlr);
581 		ctx->dev = &ctlr->dev;
582 		ctx->fsi = fsi;
583 		ctx->base = base + SPI_FSI_BASE;
584 
585 		if (of_device_is_compatible(np, "ibm,fsi2spi-restricted")) {
586 			ctx->restricted = true;
587 			ctx->max_xfr_size = SPI_FSI_MAX_XFR_SIZE_RESTRICTED;
588 		} else {
589 			ctx->restricted = false;
590 			ctx->max_xfr_size = SPI_FSI_MAX_XFR_SIZE;
591 		}
592 
593 		rc = devm_spi_register_controller(dev, ctlr);
594 		if (rc)
595 			spi_controller_put(ctlr);
596 		else
597 			num_controllers_registered++;
598 	}
599 
600 	if (!num_controllers_registered)
601 		return -ENODEV;
602 
603 	return 0;
604 }
605 
606 static const struct fsi_device_id fsi_spi_ids[] = {
607 	{ FSI_ENGID_SPI, FSI_VERSION_ANY },
608 	{ }
609 };
610 MODULE_DEVICE_TABLE(fsi, fsi_spi_ids);
611 
612 static struct fsi_driver fsi_spi_driver = {
613 	.id_table = fsi_spi_ids,
614 	.drv = {
615 		.name = "spi-fsi",
616 		.bus = &fsi_bus_type,
617 		.probe = fsi_spi_probe,
618 	},
619 };
620 module_fsi_driver(fsi_spi_driver);
621 
622 MODULE_AUTHOR("Eddie James <eajames@linux.ibm.com>");
623 MODULE_DESCRIPTION("FSI attached SPI controller");
624 MODULE_LICENSE("GPL");
625