xref: /rk3399_rockchip-uboot/drivers/spi/ich.c (revision 9eb4339ba45fc7147b013c8e8d579ebc6d8d1bdb)
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 #ifdef DEBUG_TRACE
22 #define debug_trace(fmt, args...) debug(fmt, ##args)
23 #else
24 #define debug_trace(x, args...)
25 #endif
26 
27 static u8 ich_readb(struct ich_spi_priv *priv, int reg)
28 {
29 	u8 value = readb(priv->base + reg);
30 
31 	debug_trace("read %2.2x from %4.4x\n", value, reg);
32 
33 	return value;
34 }
35 
36 static u16 ich_readw(struct ich_spi_priv *priv, int reg)
37 {
38 	u16 value = readw(priv->base + reg);
39 
40 	debug_trace("read %4.4x from %4.4x\n", value, reg);
41 
42 	return value;
43 }
44 
45 static u32 ich_readl(struct ich_spi_priv *priv, int reg)
46 {
47 	u32 value = readl(priv->base + reg);
48 
49 	debug_trace("read %8.8x from %4.4x\n", value, reg);
50 
51 	return value;
52 }
53 
54 static void ich_writeb(struct ich_spi_priv *priv, u8 value, int reg)
55 {
56 	writeb(value, priv->base + reg);
57 	debug_trace("wrote %2.2x to %4.4x\n", value, reg);
58 }
59 
60 static void ich_writew(struct ich_spi_priv *priv, u16 value, int reg)
61 {
62 	writew(value, priv->base + reg);
63 	debug_trace("wrote %4.4x to %4.4x\n", value, reg);
64 }
65 
66 static void ich_writel(struct ich_spi_priv *priv, u32 value, int reg)
67 {
68 	writel(value, priv->base + reg);
69 	debug_trace("wrote %8.8x to %4.4x\n", value, reg);
70 }
71 
72 static void write_reg(struct ich_spi_priv *priv, const void *value,
73 		      int dest_reg, uint32_t size)
74 {
75 	memcpy_toio(priv->base + dest_reg, value, size);
76 }
77 
78 static void read_reg(struct ich_spi_priv *priv, int src_reg, void *value,
79 		     uint32_t size)
80 {
81 	memcpy_fromio(value, priv->base + src_reg, size);
82 }
83 
84 static void ich_set_bbar(struct ich_spi_priv *ctlr, uint32_t minaddr)
85 {
86 	const uint32_t bbar_mask = 0x00ffff00;
87 	uint32_t ichspi_bbar;
88 
89 	minaddr &= bbar_mask;
90 	ichspi_bbar = ich_readl(ctlr, ctlr->bbar) & ~bbar_mask;
91 	ichspi_bbar |= minaddr;
92 	ich_writel(ctlr, ichspi_bbar, ctlr->bbar);
93 }
94 
95 /* @return 1 if the SPI flash supports the 33MHz speed */
96 static int ich9_can_do_33mhz(struct udevice *dev)
97 {
98 	u32 fdod, speed;
99 
100 	/* Observe SPI Descriptor Component Section 0 */
101 	dm_pci_write_config32(dev->parent, 0xb0, 0x1000);
102 
103 	/* Extract the Write/Erase SPI Frequency from descriptor */
104 	dm_pci_read_config32(dev->parent, 0xb4, &fdod);
105 
106 	/* Bits 23:21 have the fast read clock frequency, 0=20MHz, 1=33MHz */
107 	speed = (fdod >> 21) & 7;
108 
109 	return speed == 1;
110 }
111 
112 static int ich_init_controller(struct udevice *dev,
113 			       struct ich_spi_platdata *plat,
114 			       struct ich_spi_priv *ctlr)
115 {
116 	ulong sbase_addr;
117 	void *sbase;
118 
119 	/* SBASE is similar */
120 	pch_get_sbase(dev->parent, &sbase_addr);
121 	sbase = (void *)sbase_addr;
122 	debug("%s: sbase=%p\n", __func__, sbase);
123 
124 	if (plat->ich_version == PCHV_7) {
125 		struct ich7_spi_regs *ich7_spi = sbase;
126 
127 		ich7_spi = (struct ich7_spi_regs *)sbase;
128 		ctlr->ichspi_lock = readw(&ich7_spi->spis) & SPIS_LOCK;
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 == PCHV_9) {
141 		struct ich9_spi_regs *ich9_spi = sbase;
142 
143 		ctlr->ichspi_lock = readw(&ich9_spi->hsfs) & HSFS_FLOCKDN;
144 		ctlr->opmenu = offsetof(struct ich9_spi_regs, opmenu);
145 		ctlr->menubytes = sizeof(ich9_spi->opmenu);
146 		ctlr->optype = offsetof(struct ich9_spi_regs, optype);
147 		ctlr->addr = offsetof(struct ich9_spi_regs, faddr);
148 		ctlr->data = offsetof(struct ich9_spi_regs, fdata);
149 		ctlr->databytes = sizeof(ich9_spi->fdata);
150 		ctlr->status = offsetof(struct ich9_spi_regs, ssfs);
151 		ctlr->control = offsetof(struct ich9_spi_regs, ssfc);
152 		ctlr->speed = ctlr->control + 2;
153 		ctlr->bbar = offsetof(struct ich9_spi_regs, bbar);
154 		ctlr->preop = offsetof(struct ich9_spi_regs, preop);
155 		ctlr->bcr = offsetof(struct ich9_spi_regs, bcr);
156 		ctlr->pr = &ich9_spi->pr[0];
157 		ctlr->base = ich9_spi;
158 	} else {
159 		debug("ICH SPI: Unrecognised ICH version %d\n",
160 		      plat->ich_version);
161 		return -EINVAL;
162 	}
163 
164 	/* Work out the maximum speed we can support */
165 	ctlr->max_speed = 20000000;
166 	if (plat->ich_version == PCHV_9 && ich9_can_do_33mhz(dev))
167 		ctlr->max_speed = 33000000;
168 	debug("ICH SPI: Version ID %d detected at %p, speed %ld\n",
169 	      plat->ich_version, ctlr->base, ctlr->max_speed);
170 
171 	ich_set_bbar(ctlr, 0);
172 
173 	return 0;
174 }
175 
176 static inline void spi_use_out(struct spi_trans *trans, unsigned bytes)
177 {
178 	trans->out += bytes;
179 	trans->bytesout -= bytes;
180 }
181 
182 static inline void spi_use_in(struct spi_trans *trans, unsigned bytes)
183 {
184 	trans->in += bytes;
185 	trans->bytesin -= bytes;
186 }
187 
188 static void spi_setup_type(struct spi_trans *trans, int data_bytes)
189 {
190 	trans->type = 0xFF;
191 
192 	/* Try to guess spi type from read/write sizes */
193 	if (trans->bytesin == 0) {
194 		if (trans->bytesout + data_bytes > 4)
195 			/*
196 			 * If bytesin = 0 and bytesout > 4, we presume this is
197 			 * a write data operation, which is accompanied by an
198 			 * address.
199 			 */
200 			trans->type = SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS;
201 		else
202 			trans->type = SPI_OPCODE_TYPE_WRITE_NO_ADDRESS;
203 		return;
204 	}
205 
206 	if (trans->bytesout == 1) {	/* and bytesin is > 0 */
207 		trans->type = SPI_OPCODE_TYPE_READ_NO_ADDRESS;
208 		return;
209 	}
210 
211 	if (trans->bytesout == 4)	/* and bytesin is > 0 */
212 		trans->type = SPI_OPCODE_TYPE_READ_WITH_ADDRESS;
213 
214 	/* Fast read command is called with 5 bytes instead of 4 */
215 	if (trans->out[0] == SPI_OPCODE_FAST_READ && trans->bytesout == 5) {
216 		trans->type = SPI_OPCODE_TYPE_READ_WITH_ADDRESS;
217 		--trans->bytesout;
218 	}
219 }
220 
221 static int spi_setup_opcode(struct ich_spi_priv *ctlr, struct spi_trans *trans)
222 {
223 	uint16_t optypes;
224 	uint8_t opmenu[ctlr->menubytes];
225 
226 	trans->opcode = trans->out[0];
227 	spi_use_out(trans, 1);
228 	if (!ctlr->ichspi_lock) {
229 		/* The lock is off, so just use index 0. */
230 		ich_writeb(ctlr, trans->opcode, ctlr->opmenu);
231 		optypes = ich_readw(ctlr, ctlr->optype);
232 		optypes = (optypes & 0xfffc) | (trans->type & 0x3);
233 		ich_writew(ctlr, optypes, ctlr->optype);
234 		return 0;
235 	} else {
236 		/* The lock is on. See if what we need is on the menu. */
237 		uint8_t optype;
238 		uint16_t opcode_index;
239 
240 		/* Write Enable is handled as atomic prefix */
241 		if (trans->opcode == SPI_OPCODE_WREN)
242 			return 0;
243 
244 		read_reg(ctlr, ctlr->opmenu, opmenu, sizeof(opmenu));
245 		for (opcode_index = 0; opcode_index < ctlr->menubytes;
246 				opcode_index++) {
247 			if (opmenu[opcode_index] == trans->opcode)
248 				break;
249 		}
250 
251 		if (opcode_index == ctlr->menubytes) {
252 			printf("ICH SPI: Opcode %x not found\n",
253 			       trans->opcode);
254 			return -EINVAL;
255 		}
256 
257 		optypes = ich_readw(ctlr, ctlr->optype);
258 		optype = (optypes >> (opcode_index * 2)) & 0x3;
259 		if (trans->type == SPI_OPCODE_TYPE_WRITE_NO_ADDRESS &&
260 		    optype == SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS &&
261 		    trans->bytesout >= 3) {
262 			/* We guessed wrong earlier. Fix it up. */
263 			trans->type = optype;
264 		}
265 		if (optype != trans->type) {
266 			printf("ICH SPI: Transaction doesn't fit type %d\n",
267 			       optype);
268 			return -ENOSPC;
269 		}
270 		return opcode_index;
271 	}
272 }
273 
274 static int spi_setup_offset(struct spi_trans *trans)
275 {
276 	/* Separate the SPI address and data */
277 	switch (trans->type) {
278 	case SPI_OPCODE_TYPE_READ_NO_ADDRESS:
279 	case SPI_OPCODE_TYPE_WRITE_NO_ADDRESS:
280 		return 0;
281 	case SPI_OPCODE_TYPE_READ_WITH_ADDRESS:
282 	case SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS:
283 		trans->offset = ((uint32_t)trans->out[0] << 16) |
284 				((uint32_t)trans->out[1] << 8) |
285 				((uint32_t)trans->out[2] << 0);
286 		spi_use_out(trans, 3);
287 		return 1;
288 	default:
289 		printf("Unrecognized SPI transaction type %#x\n", trans->type);
290 		return -EPROTO;
291 	}
292 }
293 
294 /*
295  * Wait for up to 6s til status register bit(s) turn 1 (in case wait_til_set
296  * below is true) or 0. In case the wait was for the bit(s) to set - write
297  * those bits back, which would cause resetting them.
298  *
299  * Return the last read status value on success or -1 on failure.
300  */
301 static int ich_status_poll(struct ich_spi_priv *ctlr, u16 bitmask,
302 			   int wait_til_set)
303 {
304 	int timeout = 600000; /* This will result in 6s */
305 	u16 status = 0;
306 
307 	while (timeout--) {
308 		status = ich_readw(ctlr, ctlr->status);
309 		if (wait_til_set ^ ((status & bitmask) == 0)) {
310 			if (wait_til_set) {
311 				ich_writew(ctlr, status & bitmask,
312 					   ctlr->status);
313 			}
314 			return status;
315 		}
316 		udelay(10);
317 	}
318 
319 	printf("ICH SPI: SCIP timeout, read %x, expected %x\n",
320 	       status, bitmask);
321 	return -ETIMEDOUT;
322 }
323 
324 static int ich_spi_xfer(struct udevice *dev, unsigned int bitlen,
325 			const void *dout, void *din, unsigned long flags)
326 {
327 	struct udevice *bus = dev_get_parent(dev);
328 	struct ich_spi_platdata *plat = dev_get_platdata(bus);
329 	struct ich_spi_priv *ctlr = dev_get_priv(bus);
330 	uint16_t control;
331 	int16_t opcode_index;
332 	int with_address;
333 	int status;
334 	int bytes = bitlen / 8;
335 	struct spi_trans *trans = &ctlr->trans;
336 	unsigned type = flags & (SPI_XFER_BEGIN | SPI_XFER_END);
337 	int using_cmd = 0;
338 	int ret;
339 
340 	/* We don't support writing partial bytes */
341 	if (bitlen % 8) {
342 		debug("ICH SPI: Accessing partial bytes not supported\n");
343 		return -EPROTONOSUPPORT;
344 	}
345 
346 	/* An empty end transaction can be ignored */
347 	if (type == SPI_XFER_END && !dout && !din)
348 		return 0;
349 
350 	if (type & SPI_XFER_BEGIN)
351 		memset(trans, '\0', sizeof(*trans));
352 
353 	/* Dp we need to come back later to finish it? */
354 	if (dout && type == SPI_XFER_BEGIN) {
355 		if (bytes > ICH_MAX_CMD_LEN) {
356 			debug("ICH SPI: Command length limit exceeded\n");
357 			return -ENOSPC;
358 		}
359 		memcpy(trans->cmd, dout, bytes);
360 		trans->cmd_len = bytes;
361 		debug_trace("ICH SPI: Saved %d bytes\n", bytes);
362 		return 0;
363 	}
364 
365 	/*
366 	 * We process a 'middle' spi_xfer() call, which has no
367 	 * SPI_XFER_BEGIN/END, as an independent transaction as if it had
368 	 * an end. We therefore repeat the command. This is because ICH
369 	 * seems to have no support for this, or because interest (in digging
370 	 * out the details and creating a special case in the code) is low.
371 	 */
372 	if (trans->cmd_len) {
373 		trans->out = trans->cmd;
374 		trans->bytesout = trans->cmd_len;
375 		using_cmd = 1;
376 		debug_trace("ICH SPI: Using %d bytes\n", trans->cmd_len);
377 	} else {
378 		trans->out = dout;
379 		trans->bytesout = dout ? bytes : 0;
380 	}
381 
382 	trans->in = din;
383 	trans->bytesin = din ? bytes : 0;
384 
385 	/* There has to always at least be an opcode */
386 	if (!trans->bytesout) {
387 		debug("ICH SPI: No opcode for transfer\n");
388 		return -EPROTO;
389 	}
390 
391 	ret = ich_status_poll(ctlr, SPIS_SCIP, 0);
392 	if (ret < 0)
393 		return ret;
394 
395 	if (plat->ich_version == PCHV_7)
396 		ich_writew(ctlr, SPIS_CDS | SPIS_FCERR, ctlr->status);
397 	else
398 		ich_writeb(ctlr, SPIS_CDS | SPIS_FCERR, ctlr->status);
399 
400 	spi_setup_type(trans, using_cmd ? bytes : 0);
401 	opcode_index = spi_setup_opcode(ctlr, trans);
402 	if (opcode_index < 0)
403 		return -EINVAL;
404 	with_address = spi_setup_offset(trans);
405 	if (with_address < 0)
406 		return -EINVAL;
407 
408 	if (trans->opcode == SPI_OPCODE_WREN) {
409 		/*
410 		 * Treat Write Enable as Atomic Pre-Op if possible
411 		 * in order to prevent the Management Engine from
412 		 * issuing a transaction between WREN and DATA.
413 		 */
414 		if (!ctlr->ichspi_lock)
415 			ich_writew(ctlr, trans->opcode, ctlr->preop);
416 		return 0;
417 	}
418 
419 	if (ctlr->speed && ctlr->max_speed >= 33000000) {
420 		int byte;
421 
422 		byte = ich_readb(ctlr, ctlr->speed);
423 		if (ctlr->cur_speed >= 33000000)
424 			byte |= SSFC_SCF_33MHZ;
425 		else
426 			byte &= ~SSFC_SCF_33MHZ;
427 		ich_writeb(ctlr, byte, ctlr->speed);
428 	}
429 
430 	/* See if we have used up the command data */
431 	if (using_cmd && dout && bytes) {
432 		trans->out = dout;
433 		trans->bytesout = bytes;
434 		debug_trace("ICH SPI: Moving to data, %d bytes\n", bytes);
435 	}
436 
437 	/* Preset control fields */
438 	control = ich_readw(ctlr, ctlr->control);
439 	control &= ~SSFC_RESERVED;
440 	control = SPIC_SCGO | ((opcode_index & 0x07) << 4);
441 
442 	/* Issue atomic preop cycle if needed */
443 	if (ich_readw(ctlr, ctlr->preop))
444 		control |= SPIC_ACS;
445 
446 	if (!trans->bytesout && !trans->bytesin) {
447 		/* SPI addresses are 24 bit only */
448 		if (with_address) {
449 			ich_writel(ctlr, trans->offset & 0x00FFFFFF,
450 				   ctlr->addr);
451 		}
452 		/*
453 		 * This is a 'no data' command (like Write Enable), its
454 		 * bitesout size was 1, decremented to zero while executing
455 		 * spi_setup_opcode() above. Tell the chip to send the
456 		 * command.
457 		 */
458 		ich_writew(ctlr, control, ctlr->control);
459 
460 		/* wait for the result */
461 		status = ich_status_poll(ctlr, SPIS_CDS | SPIS_FCERR, 1);
462 		if (status < 0)
463 			return status;
464 
465 		if (status & SPIS_FCERR) {
466 			debug("ICH SPI: Command transaction error\n");
467 			return -EIO;
468 		}
469 
470 		return 0;
471 	}
472 
473 	/*
474 	 * Check if this is a write command atempting to transfer more bytes
475 	 * than the controller can handle. Iterations for writes are not
476 	 * supported here because each SPI write command needs to be preceded
477 	 * and followed by other SPI commands, and this sequence is controlled
478 	 * by the SPI chip driver.
479 	 */
480 	if (trans->bytesout > ctlr->databytes) {
481 		debug("ICH SPI: Too much to write. This should be prevented by the driver's max_write_size?\n");
482 		return -EPROTO;
483 	}
484 
485 	/*
486 	 * Read or write up to databytes bytes at a time until everything has
487 	 * been sent.
488 	 */
489 	while (trans->bytesout || trans->bytesin) {
490 		uint32_t data_length;
491 
492 		/* SPI addresses are 24 bit only */
493 		ich_writel(ctlr, trans->offset & 0x00FFFFFF, ctlr->addr);
494 
495 		if (trans->bytesout)
496 			data_length = min(trans->bytesout, ctlr->databytes);
497 		else
498 			data_length = min(trans->bytesin, ctlr->databytes);
499 
500 		/* Program data into FDATA0 to N */
501 		if (trans->bytesout) {
502 			write_reg(ctlr, trans->out, ctlr->data, data_length);
503 			spi_use_out(trans, data_length);
504 			if (with_address)
505 				trans->offset += data_length;
506 		}
507 
508 		/* Add proper control fields' values */
509 		control &= ~((ctlr->databytes - 1) << 8);
510 		control |= SPIC_DS;
511 		control |= (data_length - 1) << 8;
512 
513 		/* write it */
514 		ich_writew(ctlr, control, ctlr->control);
515 
516 		/* Wait for Cycle Done Status or Flash Cycle Error */
517 		status = ich_status_poll(ctlr, SPIS_CDS | SPIS_FCERR, 1);
518 		if (status < 0)
519 			return status;
520 
521 		if (status & SPIS_FCERR) {
522 			debug("ICH SPI: Data transaction error %x\n", status);
523 			return -EIO;
524 		}
525 
526 		if (trans->bytesin) {
527 			read_reg(ctlr, ctlr->data, trans->in, data_length);
528 			spi_use_in(trans, data_length);
529 			if (with_address)
530 				trans->offset += data_length;
531 		}
532 	}
533 
534 	/* Clear atomic preop now that xfer is done */
535 	ich_writew(ctlr, 0, ctlr->preop);
536 
537 	return 0;
538 }
539 
540 /*
541  * This uses the SPI controller from the Intel Cougar Point and Panther Point
542  * PCH to write-protect portions of the SPI flash until reboot. The changes
543  * don't actually take effect until the HSFS[FLOCKDN] bit is set, but that's
544  * done elsewhere.
545  */
546 int spi_write_protect_region(struct udevice *dev, uint32_t lower_limit,
547 			     uint32_t length, int hint)
548 {
549 	struct udevice *bus = dev->parent;
550 	struct ich_spi_priv *ctlr = dev_get_priv(bus);
551 	uint32_t tmplong;
552 	uint32_t upper_limit;
553 
554 	if (!ctlr->pr) {
555 		printf("%s: operation not supported on this chipset\n",
556 		       __func__);
557 		return -ENOSYS;
558 	}
559 
560 	if (length == 0 ||
561 	    lower_limit > (0xFFFFFFFFUL - length) + 1 ||
562 	    hint < 0 || hint > 4) {
563 		printf("%s(0x%x, 0x%x, %d): invalid args\n", __func__,
564 		       lower_limit, length, hint);
565 		return -EPERM;
566 	}
567 
568 	upper_limit = lower_limit + length - 1;
569 
570 	/*
571 	 * Determine bits to write, as follows:
572 	 *  31     Write-protection enable (includes erase operation)
573 	 *  30:29  reserved
574 	 *  28:16  Upper Limit (FLA address bits 24:12, with 11:0 == 0xfff)
575 	 *  15     Read-protection enable
576 	 *  14:13  reserved
577 	 *  12:0   Lower Limit (FLA address bits 24:12, with 11:0 == 0x000)
578 	 */
579 	tmplong = 0x80000000 |
580 		((upper_limit & 0x01fff000) << 4) |
581 		((lower_limit & 0x01fff000) >> 12);
582 
583 	printf("%s: writing 0x%08x to %p\n", __func__, tmplong,
584 	       &ctlr->pr[hint]);
585 	ctlr->pr[hint] = tmplong;
586 
587 	return 0;
588 }
589 
590 static int ich_spi_probe(struct udevice *dev)
591 {
592 	struct ich_spi_platdata *plat = dev_get_platdata(dev);
593 	struct ich_spi_priv *priv = dev_get_priv(dev);
594 	uint8_t bios_cntl;
595 	int ret;
596 
597 	/* Check the ICH version */
598 	plat->ich_version = pch_get_version(dev->parent);
599 
600 	ret = ich_init_controller(dev, plat, priv);
601 	if (ret)
602 		return ret;
603 	/* Disable the BIOS write protect so write commands are allowed */
604 	ret = pch_set_spi_protect(dev->parent, false);
605 	if (ret == -ENOSYS) {
606 		bios_cntl = ich_readb(priv, priv->bcr);
607 		bios_cntl &= ~BIT(5);	/* clear Enable InSMM_STS (EISS) */
608 		bios_cntl |= 1;		/* Write Protect Disable (WPD) */
609 		ich_writeb(priv, bios_cntl, priv->bcr);
610 	} else if (ret) {
611 		debug("%s: Failed to disable write-protect: err=%d\n",
612 		      __func__, ret);
613 		return ret;
614 	}
615 
616 	priv->cur_speed = priv->max_speed;
617 
618 	return 0;
619 }
620 
621 static int ich_spi_set_speed(struct udevice *bus, uint speed)
622 {
623 	struct ich_spi_priv *priv = dev_get_priv(bus);
624 
625 	priv->cur_speed = speed;
626 
627 	return 0;
628 }
629 
630 static int ich_spi_set_mode(struct udevice *bus, uint mode)
631 {
632 	debug("%s: mode=%d\n", __func__, mode);
633 
634 	return 0;
635 }
636 
637 static int ich_spi_child_pre_probe(struct udevice *dev)
638 {
639 	struct udevice *bus = dev_get_parent(dev);
640 	struct ich_spi_platdata *plat = dev_get_platdata(bus);
641 	struct ich_spi_priv *priv = dev_get_priv(bus);
642 	struct spi_slave *slave = dev_get_parent_priv(dev);
643 
644 	/*
645 	 * Yes this controller can only write a small number of bytes at
646 	 * once! The limit is typically 64 bytes.
647 	 */
648 	slave->max_write_size = priv->databytes;
649 	/*
650 	 * ICH 7 SPI controller only supports array read command
651 	 * and byte program command for SST flash
652 	 */
653 	if (plat->ich_version == PCHV_7) {
654 		slave->mode_rx = SPI_RX_SLOW;
655 		slave->mode = SPI_TX_BYTE;
656 	}
657 
658 	return 0;
659 }
660 
661 static const struct dm_spi_ops ich_spi_ops = {
662 	.xfer		= ich_spi_xfer,
663 	.set_speed	= ich_spi_set_speed,
664 	.set_mode	= ich_spi_set_mode,
665 	/*
666 	 * cs_info is not needed, since we require all chip selects to be
667 	 * in the device tree explicitly
668 	 */
669 };
670 
671 static const struct udevice_id ich_spi_ids[] = {
672 	{ .compatible = "intel,ich-spi" },
673 	{ }
674 };
675 
676 U_BOOT_DRIVER(ich_spi) = {
677 	.name	= "ich_spi",
678 	.id	= UCLASS_SPI,
679 	.of_match = ich_spi_ids,
680 	.ops	= &ich_spi_ops,
681 	.platdata_auto_alloc_size = sizeof(struct ich_spi_platdata),
682 	.priv_auto_alloc_size = sizeof(struct ich_spi_priv),
683 	.child_pre_probe = ich_spi_child_pre_probe,
684 	.probe	= ich_spi_probe,
685 };
686