xref: /openbmc/u-boot/drivers/spi/ich.c (revision b44b3026)
1 /*
2  * Copyright (c) 2011-12 The Chromium OS Authors.
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  *
6  * This file is derived from the flashrom project.
7  */
8 
9 #include <common.h>
10 #include <dm.h>
11 #include <errno.h>
12 #include <malloc.h>
13 #include <pch.h>
14 #include <pci.h>
15 #include <pci_ids.h>
16 #include <spi.h>
17 #include <asm/io.h>
18 
19 #include "ich.h"
20 
21 DECLARE_GLOBAL_DATA_PTR;
22 
23 #ifdef DEBUG_TRACE
24 #define debug_trace(fmt, args...) debug(fmt, ##args)
25 #else
26 #define debug_trace(x, args...)
27 #endif
28 
29 static u8 ich_readb(struct ich_spi_priv *priv, int reg)
30 {
31 	u8 value = readb(priv->base + reg);
32 
33 	debug_trace("read %2.2x from %4.4x\n", value, reg);
34 
35 	return value;
36 }
37 
38 static u16 ich_readw(struct ich_spi_priv *priv, int reg)
39 {
40 	u16 value = readw(priv->base + reg);
41 
42 	debug_trace("read %4.4x from %4.4x\n", value, reg);
43 
44 	return value;
45 }
46 
47 static u32 ich_readl(struct ich_spi_priv *priv, int reg)
48 {
49 	u32 value = readl(priv->base + reg);
50 
51 	debug_trace("read %8.8x from %4.4x\n", value, reg);
52 
53 	return value;
54 }
55 
56 static void ich_writeb(struct ich_spi_priv *priv, u8 value, int reg)
57 {
58 	writeb(value, priv->base + reg);
59 	debug_trace("wrote %2.2x to %4.4x\n", value, reg);
60 }
61 
62 static void ich_writew(struct ich_spi_priv *priv, u16 value, int reg)
63 {
64 	writew(value, priv->base + reg);
65 	debug_trace("wrote %4.4x to %4.4x\n", value, reg);
66 }
67 
68 static void ich_writel(struct ich_spi_priv *priv, u32 value, int reg)
69 {
70 	writel(value, priv->base + reg);
71 	debug_trace("wrote %8.8x to %4.4x\n", value, reg);
72 }
73 
74 static void write_reg(struct ich_spi_priv *priv, const void *value,
75 		      int dest_reg, uint32_t size)
76 {
77 	memcpy_toio(priv->base + dest_reg, value, size);
78 }
79 
80 static void read_reg(struct ich_spi_priv *priv, int src_reg, void *value,
81 		     uint32_t size)
82 {
83 	memcpy_fromio(value, priv->base + src_reg, size);
84 }
85 
86 static void ich_set_bbar(struct ich_spi_priv *ctlr, uint32_t minaddr)
87 {
88 	const uint32_t bbar_mask = 0x00ffff00;
89 	uint32_t ichspi_bbar;
90 
91 	minaddr &= bbar_mask;
92 	ichspi_bbar = ich_readl(ctlr, ctlr->bbar) & ~bbar_mask;
93 	ichspi_bbar |= minaddr;
94 	ich_writel(ctlr, ichspi_bbar, ctlr->bbar);
95 }
96 
97 /* @return 1 if the SPI flash supports the 33MHz speed */
98 static int ich9_can_do_33mhz(struct udevice *dev)
99 {
100 	u32 fdod, speed;
101 
102 	/* Observe SPI Descriptor Component Section 0 */
103 	dm_pci_write_config32(dev->parent, 0xb0, 0x1000);
104 
105 	/* Extract the Write/Erase SPI Frequency from descriptor */
106 	dm_pci_read_config32(dev->parent, 0xb4, &fdod);
107 
108 	/* Bits 23:21 have the fast read clock frequency, 0=20MHz, 1=33MHz */
109 	speed = (fdod >> 21) & 7;
110 
111 	return speed == 1;
112 }
113 
114 static int ich_init_controller(struct udevice *dev,
115 			       struct ich_spi_platdata *plat,
116 			       struct ich_spi_priv *ctlr)
117 {
118 	ulong sbase_addr;
119 	void *sbase;
120 
121 	/* SBASE is similar */
122 	pch_get_spi_base(dev->parent, &sbase_addr);
123 	sbase = (void *)sbase_addr;
124 	debug("%s: sbase=%p\n", __func__, sbase);
125 
126 	if (plat->ich_version == ICHV_7) {
127 		struct ich7_spi_regs *ich7_spi = sbase;
128 
129 		ctlr->opmenu = offsetof(struct ich7_spi_regs, opmenu);
130 		ctlr->menubytes = sizeof(ich7_spi->opmenu);
131 		ctlr->optype = offsetof(struct ich7_spi_regs, optype);
132 		ctlr->addr = offsetof(struct ich7_spi_regs, spia);
133 		ctlr->data = offsetof(struct ich7_spi_regs, spid);
134 		ctlr->databytes = sizeof(ich7_spi->spid);
135 		ctlr->status = offsetof(struct ich7_spi_regs, spis);
136 		ctlr->control = offsetof(struct ich7_spi_regs, spic);
137 		ctlr->bbar = offsetof(struct ich7_spi_regs, bbar);
138 		ctlr->preop = offsetof(struct ich7_spi_regs, preop);
139 		ctlr->base = ich7_spi;
140 	} else if (plat->ich_version == ICHV_9) {
141 		struct ich9_spi_regs *ich9_spi = sbase;
142 
143 		ctlr->opmenu = offsetof(struct ich9_spi_regs, opmenu);
144 		ctlr->menubytes = sizeof(ich9_spi->opmenu);
145 		ctlr->optype = offsetof(struct ich9_spi_regs, optype);
146 		ctlr->addr = offsetof(struct ich9_spi_regs, faddr);
147 		ctlr->data = offsetof(struct ich9_spi_regs, fdata);
148 		ctlr->databytes = sizeof(ich9_spi->fdata);
149 		ctlr->status = offsetof(struct ich9_spi_regs, ssfs);
150 		ctlr->control = offsetof(struct ich9_spi_regs, ssfc);
151 		ctlr->speed = ctlr->control + 2;
152 		ctlr->bbar = offsetof(struct ich9_spi_regs, bbar);
153 		ctlr->preop = offsetof(struct ich9_spi_regs, preop);
154 		ctlr->bcr = offsetof(struct ich9_spi_regs, bcr);
155 		ctlr->pr = &ich9_spi->pr[0];
156 		ctlr->base = ich9_spi;
157 	} else {
158 		debug("ICH SPI: Unrecognised ICH version %d\n",
159 		      plat->ich_version);
160 		return -EINVAL;
161 	}
162 
163 	/* Work out the maximum speed we can support */
164 	ctlr->max_speed = 20000000;
165 	if (plat->ich_version == ICHV_9 && ich9_can_do_33mhz(dev))
166 		ctlr->max_speed = 33000000;
167 	debug("ICH SPI: Version ID %d detected at %p, speed %ld\n",
168 	      plat->ich_version, ctlr->base, ctlr->max_speed);
169 
170 	ich_set_bbar(ctlr, 0);
171 
172 	return 0;
173 }
174 
175 static inline void spi_use_out(struct spi_trans *trans, unsigned bytes)
176 {
177 	trans->out += bytes;
178 	trans->bytesout -= bytes;
179 }
180 
181 static inline void spi_use_in(struct spi_trans *trans, unsigned bytes)
182 {
183 	trans->in += bytes;
184 	trans->bytesin -= bytes;
185 }
186 
187 static bool spi_lock_status(struct ich_spi_platdata *plat, void *sbase)
188 {
189 	int lock = 0;
190 
191 	if (plat->ich_version == ICHV_7) {
192 		struct ich7_spi_regs *ich7_spi = sbase;
193 
194 		lock = readw(&ich7_spi->spis) & SPIS_LOCK;
195 	} else if (plat->ich_version == ICHV_9) {
196 		struct ich9_spi_regs *ich9_spi = sbase;
197 
198 		lock = readw(&ich9_spi->hsfs) & HSFS_FLOCKDN;
199 	}
200 
201 	return lock != 0;
202 }
203 
204 static void spi_setup_type(struct spi_trans *trans, int data_bytes)
205 {
206 	trans->type = 0xFF;
207 
208 	/* Try to guess spi type from read/write sizes */
209 	if (trans->bytesin == 0) {
210 		if (trans->bytesout + data_bytes > 4)
211 			/*
212 			 * If bytesin = 0 and bytesout > 4, we presume this is
213 			 * a write data operation, which is accompanied by an
214 			 * address.
215 			 */
216 			trans->type = SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS;
217 		else
218 			trans->type = SPI_OPCODE_TYPE_WRITE_NO_ADDRESS;
219 		return;
220 	}
221 
222 	if (trans->bytesout == 1) {	/* and bytesin is > 0 */
223 		trans->type = SPI_OPCODE_TYPE_READ_NO_ADDRESS;
224 		return;
225 	}
226 
227 	if (trans->bytesout == 4)	/* and bytesin is > 0 */
228 		trans->type = SPI_OPCODE_TYPE_READ_WITH_ADDRESS;
229 
230 	/* Fast read command is called with 5 bytes instead of 4 */
231 	if (trans->out[0] == SPI_OPCODE_FAST_READ && trans->bytesout == 5) {
232 		trans->type = SPI_OPCODE_TYPE_READ_WITH_ADDRESS;
233 		--trans->bytesout;
234 	}
235 }
236 
237 static int spi_setup_opcode(struct ich_spi_priv *ctlr, struct spi_trans *trans,
238 			    bool lock)
239 {
240 	uint16_t optypes;
241 	uint8_t opmenu[ctlr->menubytes];
242 
243 	trans->opcode = trans->out[0];
244 	spi_use_out(trans, 1);
245 	if (!lock) {
246 		/* The lock is off, so just use index 0. */
247 		ich_writeb(ctlr, trans->opcode, ctlr->opmenu);
248 		optypes = ich_readw(ctlr, ctlr->optype);
249 		optypes = (optypes & 0xfffc) | (trans->type & 0x3);
250 		ich_writew(ctlr, optypes, ctlr->optype);
251 		return 0;
252 	} else {
253 		/* The lock is on. See if what we need is on the menu. */
254 		uint8_t optype;
255 		uint16_t opcode_index;
256 
257 		/* Write Enable is handled as atomic prefix */
258 		if (trans->opcode == SPI_OPCODE_WREN)
259 			return 0;
260 
261 		read_reg(ctlr, ctlr->opmenu, opmenu, sizeof(opmenu));
262 		for (opcode_index = 0; opcode_index < ctlr->menubytes;
263 				opcode_index++) {
264 			if (opmenu[opcode_index] == trans->opcode)
265 				break;
266 		}
267 
268 		if (opcode_index == ctlr->menubytes) {
269 			printf("ICH SPI: Opcode %x not found\n",
270 			       trans->opcode);
271 			return -EINVAL;
272 		}
273 
274 		optypes = ich_readw(ctlr, ctlr->optype);
275 		optype = (optypes >> (opcode_index * 2)) & 0x3;
276 		if (trans->type == SPI_OPCODE_TYPE_WRITE_NO_ADDRESS &&
277 		    optype == SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS &&
278 		    trans->bytesout >= 3) {
279 			/* We guessed wrong earlier. Fix it up. */
280 			trans->type = optype;
281 		}
282 		if (optype != trans->type) {
283 			printf("ICH SPI: Transaction doesn't fit type %d\n",
284 			       optype);
285 			return -ENOSPC;
286 		}
287 		return opcode_index;
288 	}
289 }
290 
291 static int spi_setup_offset(struct spi_trans *trans)
292 {
293 	/* Separate the SPI address and data */
294 	switch (trans->type) {
295 	case SPI_OPCODE_TYPE_READ_NO_ADDRESS:
296 	case SPI_OPCODE_TYPE_WRITE_NO_ADDRESS:
297 		return 0;
298 	case SPI_OPCODE_TYPE_READ_WITH_ADDRESS:
299 	case SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS:
300 		trans->offset = ((uint32_t)trans->out[0] << 16) |
301 				((uint32_t)trans->out[1] << 8) |
302 				((uint32_t)trans->out[2] << 0);
303 		spi_use_out(trans, 3);
304 		return 1;
305 	default:
306 		printf("Unrecognized SPI transaction type %#x\n", trans->type);
307 		return -EPROTO;
308 	}
309 }
310 
311 /*
312  * Wait for up to 6s til status register bit(s) turn 1 (in case wait_til_set
313  * below is true) or 0. In case the wait was for the bit(s) to set - write
314  * those bits back, which would cause resetting them.
315  *
316  * Return the last read status value on success or -1 on failure.
317  */
318 static int ich_status_poll(struct ich_spi_priv *ctlr, u16 bitmask,
319 			   int wait_til_set)
320 {
321 	int timeout = 600000; /* This will result in 6s */
322 	u16 status = 0;
323 
324 	while (timeout--) {
325 		status = ich_readw(ctlr, ctlr->status);
326 		if (wait_til_set ^ ((status & bitmask) == 0)) {
327 			if (wait_til_set) {
328 				ich_writew(ctlr, status & bitmask,
329 					   ctlr->status);
330 			}
331 			return status;
332 		}
333 		udelay(10);
334 	}
335 
336 	printf("ICH SPI: SCIP timeout, read %x, expected %x\n",
337 	       status, bitmask);
338 	return -ETIMEDOUT;
339 }
340 
341 void ich_spi_config_opcode(struct udevice *dev)
342 {
343 	struct ich_spi_priv *ctlr = dev_get_priv(dev);
344 
345 	/*
346 	 * PREOP, OPTYPE, OPMENU1/OPMENU2 registers can be locked down
347 	 * to prevent accidental or intentional writes. Before they get
348 	 * locked down, these registers should be initialized properly.
349 	 */
350 	ich_writew(ctlr, SPI_OPPREFIX, ctlr->preop);
351 	ich_writew(ctlr, SPI_OPTYPE, ctlr->optype);
352 	ich_writel(ctlr, SPI_OPMENU_LOWER, ctlr->opmenu);
353 	ich_writel(ctlr, SPI_OPMENU_UPPER, ctlr->opmenu + sizeof(u32));
354 }
355 
356 static int ich_spi_xfer(struct udevice *dev, unsigned int bitlen,
357 			const void *dout, void *din, unsigned long flags)
358 {
359 	struct udevice *bus = dev_get_parent(dev);
360 	struct ich_spi_platdata *plat = dev_get_platdata(bus);
361 	struct ich_spi_priv *ctlr = dev_get_priv(bus);
362 	uint16_t control;
363 	int16_t opcode_index;
364 	int with_address;
365 	int status;
366 	int bytes = bitlen / 8;
367 	struct spi_trans *trans = &ctlr->trans;
368 	unsigned type = flags & (SPI_XFER_BEGIN | SPI_XFER_END);
369 	int using_cmd = 0;
370 	bool lock = spi_lock_status(plat, ctlr->base);
371 	int ret;
372 
373 	/* We don't support writing partial bytes */
374 	if (bitlen % 8) {
375 		debug("ICH SPI: Accessing partial bytes not supported\n");
376 		return -EPROTONOSUPPORT;
377 	}
378 
379 	/* An empty end transaction can be ignored */
380 	if (type == SPI_XFER_END && !dout && !din)
381 		return 0;
382 
383 	if (type & SPI_XFER_BEGIN)
384 		memset(trans, '\0', sizeof(*trans));
385 
386 	/* Dp we need to come back later to finish it? */
387 	if (dout && type == SPI_XFER_BEGIN) {
388 		if (bytes > ICH_MAX_CMD_LEN) {
389 			debug("ICH SPI: Command length limit exceeded\n");
390 			return -ENOSPC;
391 		}
392 		memcpy(trans->cmd, dout, bytes);
393 		trans->cmd_len = bytes;
394 		debug_trace("ICH SPI: Saved %d bytes\n", bytes);
395 		return 0;
396 	}
397 
398 	/*
399 	 * We process a 'middle' spi_xfer() call, which has no
400 	 * SPI_XFER_BEGIN/END, as an independent transaction as if it had
401 	 * an end. We therefore repeat the command. This is because ICH
402 	 * seems to have no support for this, or because interest (in digging
403 	 * out the details and creating a special case in the code) is low.
404 	 */
405 	if (trans->cmd_len) {
406 		trans->out = trans->cmd;
407 		trans->bytesout = trans->cmd_len;
408 		using_cmd = 1;
409 		debug_trace("ICH SPI: Using %d bytes\n", trans->cmd_len);
410 	} else {
411 		trans->out = dout;
412 		trans->bytesout = dout ? bytes : 0;
413 	}
414 
415 	trans->in = din;
416 	trans->bytesin = din ? bytes : 0;
417 
418 	/* There has to always at least be an opcode */
419 	if (!trans->bytesout) {
420 		debug("ICH SPI: No opcode for transfer\n");
421 		return -EPROTO;
422 	}
423 
424 	ret = ich_status_poll(ctlr, SPIS_SCIP, 0);
425 	if (ret < 0)
426 		return ret;
427 
428 	if (plat->ich_version == ICHV_7)
429 		ich_writew(ctlr, SPIS_CDS | SPIS_FCERR, ctlr->status);
430 	else
431 		ich_writeb(ctlr, SPIS_CDS | SPIS_FCERR, ctlr->status);
432 
433 	spi_setup_type(trans, using_cmd ? bytes : 0);
434 	opcode_index = spi_setup_opcode(ctlr, trans, lock);
435 	if (opcode_index < 0)
436 		return -EINVAL;
437 	with_address = spi_setup_offset(trans);
438 	if (with_address < 0)
439 		return -EINVAL;
440 
441 	if (trans->opcode == SPI_OPCODE_WREN) {
442 		/*
443 		 * Treat Write Enable as Atomic Pre-Op if possible
444 		 * in order to prevent the Management Engine from
445 		 * issuing a transaction between WREN and DATA.
446 		 */
447 		if (!lock)
448 			ich_writew(ctlr, trans->opcode, ctlr->preop);
449 		return 0;
450 	}
451 
452 	if (ctlr->speed && ctlr->max_speed >= 33000000) {
453 		int byte;
454 
455 		byte = ich_readb(ctlr, ctlr->speed);
456 		if (ctlr->cur_speed >= 33000000)
457 			byte |= SSFC_SCF_33MHZ;
458 		else
459 			byte &= ~SSFC_SCF_33MHZ;
460 		ich_writeb(ctlr, byte, ctlr->speed);
461 	}
462 
463 	/* See if we have used up the command data */
464 	if (using_cmd && dout && bytes) {
465 		trans->out = dout;
466 		trans->bytesout = bytes;
467 		debug_trace("ICH SPI: Moving to data, %d bytes\n", bytes);
468 	}
469 
470 	/* Preset control fields */
471 	control = SPIC_SCGO | ((opcode_index & 0x07) << 4);
472 
473 	/* Issue atomic preop cycle if needed */
474 	if (ich_readw(ctlr, ctlr->preop))
475 		control |= SPIC_ACS;
476 
477 	if (!trans->bytesout && !trans->bytesin) {
478 		/* SPI addresses are 24 bit only */
479 		if (with_address) {
480 			ich_writel(ctlr, trans->offset & 0x00FFFFFF,
481 				   ctlr->addr);
482 		}
483 		/*
484 		 * This is a 'no data' command (like Write Enable), its
485 		 * bitesout size was 1, decremented to zero while executing
486 		 * spi_setup_opcode() above. Tell the chip to send the
487 		 * command.
488 		 */
489 		ich_writew(ctlr, control, ctlr->control);
490 
491 		/* wait for the result */
492 		status = ich_status_poll(ctlr, SPIS_CDS | SPIS_FCERR, 1);
493 		if (status < 0)
494 			return status;
495 
496 		if (status & SPIS_FCERR) {
497 			debug("ICH SPI: Command transaction error\n");
498 			return -EIO;
499 		}
500 
501 		return 0;
502 	}
503 
504 	/*
505 	 * Check if this is a write command atempting to transfer more bytes
506 	 * than the controller can handle. Iterations for writes are not
507 	 * supported here because each SPI write command needs to be preceded
508 	 * and followed by other SPI commands, and this sequence is controlled
509 	 * by the SPI chip driver.
510 	 */
511 	if (trans->bytesout > ctlr->databytes) {
512 		debug("ICH SPI: Too much to write. This should be prevented by the driver's max_write_size?\n");
513 		return -EPROTO;
514 	}
515 
516 	/*
517 	 * Read or write up to databytes bytes at a time until everything has
518 	 * been sent.
519 	 */
520 	while (trans->bytesout || trans->bytesin) {
521 		uint32_t data_length;
522 
523 		/* SPI addresses are 24 bit only */
524 		ich_writel(ctlr, trans->offset & 0x00FFFFFF, ctlr->addr);
525 
526 		if (trans->bytesout)
527 			data_length = min(trans->bytesout, ctlr->databytes);
528 		else
529 			data_length = min(trans->bytesin, ctlr->databytes);
530 
531 		/* Program data into FDATA0 to N */
532 		if (trans->bytesout) {
533 			write_reg(ctlr, trans->out, ctlr->data, data_length);
534 			spi_use_out(trans, data_length);
535 			if (with_address)
536 				trans->offset += data_length;
537 		}
538 
539 		/* Add proper control fields' values */
540 		control &= ~((ctlr->databytes - 1) << 8);
541 		control |= SPIC_DS;
542 		control |= (data_length - 1) << 8;
543 
544 		/* write it */
545 		ich_writew(ctlr, control, ctlr->control);
546 
547 		/* Wait for Cycle Done Status or Flash Cycle Error */
548 		status = ich_status_poll(ctlr, SPIS_CDS | SPIS_FCERR, 1);
549 		if (status < 0)
550 			return status;
551 
552 		if (status & SPIS_FCERR) {
553 			debug("ICH SPI: Data transaction error %x\n", status);
554 			return -EIO;
555 		}
556 
557 		if (trans->bytesin) {
558 			read_reg(ctlr, ctlr->data, trans->in, data_length);
559 			spi_use_in(trans, data_length);
560 			if (with_address)
561 				trans->offset += data_length;
562 		}
563 	}
564 
565 	/* Clear atomic preop now that xfer is done */
566 	if (!lock)
567 		ich_writew(ctlr, 0, ctlr->preop);
568 
569 	return 0;
570 }
571 
572 static int ich_spi_probe(struct udevice *dev)
573 {
574 	struct ich_spi_platdata *plat = dev_get_platdata(dev);
575 	struct ich_spi_priv *priv = dev_get_priv(dev);
576 	uint8_t bios_cntl;
577 	int ret;
578 
579 	ret = ich_init_controller(dev, plat, priv);
580 	if (ret)
581 		return ret;
582 	/* Disable the BIOS write protect so write commands are allowed */
583 	ret = pch_set_spi_protect(dev->parent, false);
584 	if (ret == -ENOSYS) {
585 		bios_cntl = ich_readb(priv, priv->bcr);
586 		bios_cntl &= ~BIT(5);	/* clear Enable InSMM_STS (EISS) */
587 		bios_cntl |= 1;		/* Write Protect Disable (WPD) */
588 		ich_writeb(priv, bios_cntl, priv->bcr);
589 	} else if (ret) {
590 		debug("%s: Failed to disable write-protect: err=%d\n",
591 		      __func__, ret);
592 		return ret;
593 	}
594 
595 	priv->cur_speed = priv->max_speed;
596 
597 	return 0;
598 }
599 
600 static int ich_spi_remove(struct udevice *bus)
601 {
602 	/*
603 	 * Configure SPI controller so that the Linux MTD driver can fully
604 	 * access the SPI NOR chip
605 	 */
606 	ich_spi_config_opcode(bus);
607 
608 	return 0;
609 }
610 
611 static int ich_spi_set_speed(struct udevice *bus, uint speed)
612 {
613 	struct ich_spi_priv *priv = dev_get_priv(bus);
614 
615 	priv->cur_speed = speed;
616 
617 	return 0;
618 }
619 
620 static int ich_spi_set_mode(struct udevice *bus, uint mode)
621 {
622 	debug("%s: mode=%d\n", __func__, mode);
623 
624 	return 0;
625 }
626 
627 static int ich_spi_child_pre_probe(struct udevice *dev)
628 {
629 	struct udevice *bus = dev_get_parent(dev);
630 	struct ich_spi_platdata *plat = dev_get_platdata(bus);
631 	struct ich_spi_priv *priv = dev_get_priv(bus);
632 	struct spi_slave *slave = dev_get_parent_priv(dev);
633 
634 	/*
635 	 * Yes this controller can only write a small number of bytes at
636 	 * once! The limit is typically 64 bytes.
637 	 */
638 	slave->max_write_size = priv->databytes;
639 	/*
640 	 * ICH 7 SPI controller only supports array read command
641 	 * and byte program command for SST flash
642 	 */
643 	if (plat->ich_version == ICHV_7)
644 		slave->mode = SPI_RX_SLOW | SPI_TX_BYTE;
645 
646 	return 0;
647 }
648 
649 static int ich_spi_ofdata_to_platdata(struct udevice *dev)
650 {
651 	struct ich_spi_platdata *plat = dev_get_platdata(dev);
652 	int node = dev_of_offset(dev);
653 	int ret;
654 
655 	ret = fdt_node_check_compatible(gd->fdt_blob, node, "intel,ich7-spi");
656 	if (ret == 0) {
657 		plat->ich_version = ICHV_7;
658 	} else {
659 		ret = fdt_node_check_compatible(gd->fdt_blob, node,
660 						"intel,ich9-spi");
661 		if (ret == 0)
662 			plat->ich_version = ICHV_9;
663 	}
664 
665 	return ret;
666 }
667 
668 static const struct dm_spi_ops ich_spi_ops = {
669 	.xfer		= ich_spi_xfer,
670 	.set_speed	= ich_spi_set_speed,
671 	.set_mode	= ich_spi_set_mode,
672 	/*
673 	 * cs_info is not needed, since we require all chip selects to be
674 	 * in the device tree explicitly
675 	 */
676 };
677 
678 static const struct udevice_id ich_spi_ids[] = {
679 	{ .compatible = "intel,ich7-spi" },
680 	{ .compatible = "intel,ich9-spi" },
681 	{ }
682 };
683 
684 U_BOOT_DRIVER(ich_spi) = {
685 	.name	= "ich_spi",
686 	.id	= UCLASS_SPI,
687 	.of_match = ich_spi_ids,
688 	.ops	= &ich_spi_ops,
689 	.ofdata_to_platdata = ich_spi_ofdata_to_platdata,
690 	.platdata_auto_alloc_size = sizeof(struct ich_spi_platdata),
691 	.priv_auto_alloc_size = sizeof(struct ich_spi_priv),
692 	.child_pre_probe = ich_spi_child_pre_probe,
693 	.probe	= ich_spi_probe,
694 	.remove	= ich_spi_remove,
695 	.flags	= DM_FLAG_OS_PREPARE,
696 };
697