xref: /openbmc/u-boot/drivers/spi/ich.c (revision dd580801)
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 <malloc.h>
11 #include <spi.h>
12 #include <pci.h>
13 #include <pci_ids.h>
14 #include <asm/io.h>
15 
16 #include "ich.h"
17 
18 #define SPI_OPCODE_WREN      0x06
19 #define SPI_OPCODE_FAST_READ 0x0b
20 
21 struct ich_ctlr {
22 	pci_dev_t dev;		/* PCI device number */
23 	int ich_version;	/* Controller version, 7 or 9 */
24 	int ichspi_lock;
25 	int locked;
26 	uint8_t *opmenu;
27 	int menubytes;
28 	void *base;		/* Base of register set */
29 	uint16_t *preop;
30 	uint16_t *optype;
31 	uint32_t *addr;
32 	uint8_t *data;
33 	unsigned databytes;
34 	uint8_t *status;
35 	uint16_t *control;
36 	uint32_t *bbar;
37 	uint32_t *pr;		/* only for ich9 */
38 	uint8_t *speed;		/* pointer to speed control */
39 	ulong max_speed;	/* Maximum bus speed in MHz */
40 };
41 
42 struct ich_ctlr ctlr;
43 
44 static inline struct ich_spi_slave *to_ich_spi(struct spi_slave *slave)
45 {
46 	return container_of(slave, struct ich_spi_slave, slave);
47 }
48 
49 static unsigned int ich_reg(const void *addr)
50 {
51 	return (unsigned)(addr - ctlr.base) & 0xffff;
52 }
53 
54 static u8 ich_readb(const void *addr)
55 {
56 	u8 value = readb(addr);
57 
58 	debug("read %2.2x from %4.4x\n", value, ich_reg(addr));
59 
60 	return value;
61 }
62 
63 static u16 ich_readw(const void *addr)
64 {
65 	u16 value = readw(addr);
66 
67 	debug("read %4.4x from %4.4x\n", value, ich_reg(addr));
68 
69 	return value;
70 }
71 
72 static u32 ich_readl(const void *addr)
73 {
74 	u32 value = readl(addr);
75 
76 	debug("read %8.8x from %4.4x\n", value, ich_reg(addr));
77 
78 	return value;
79 }
80 
81 static void ich_writeb(u8 value, void *addr)
82 {
83 	writeb(value, addr);
84 	debug("wrote %2.2x to %4.4x\n", value, ich_reg(addr));
85 }
86 
87 static void ich_writew(u16 value, void *addr)
88 {
89 	writew(value, addr);
90 	debug("wrote %4.4x to %4.4x\n", value, ich_reg(addr));
91 }
92 
93 static void ich_writel(u32 value, void *addr)
94 {
95 	writel(value, addr);
96 	debug("wrote %8.8x to %4.4x\n", value, ich_reg(addr));
97 }
98 
99 static void write_reg(const void *value, void *dest, uint32_t size)
100 {
101 	memcpy_toio(dest, value, size);
102 }
103 
104 static void read_reg(const void *src, void *value, uint32_t size)
105 {
106 	memcpy_fromio(value, src, size);
107 }
108 
109 static void ich_set_bbar(struct ich_ctlr *ctlr, uint32_t minaddr)
110 {
111 	const uint32_t bbar_mask = 0x00ffff00;
112 	uint32_t ichspi_bbar;
113 
114 	minaddr &= bbar_mask;
115 	ichspi_bbar = ich_readl(ctlr->bbar) & ~bbar_mask;
116 	ichspi_bbar |= minaddr;
117 	ich_writel(ichspi_bbar, ctlr->bbar);
118 }
119 
120 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
121 {
122 	puts("spi_cs_is_valid used but not implemented\n");
123 	return 0;
124 }
125 
126 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
127 		unsigned int max_hz, unsigned int mode)
128 {
129 	struct ich_spi_slave *ich;
130 
131 	ich = spi_alloc_slave(struct ich_spi_slave, bus, cs);
132 	if (!ich) {
133 		puts("ICH SPI: Out of memory\n");
134 		return NULL;
135 	}
136 
137 	/*
138 	 * Yes this controller can only write a small number of bytes at
139 	 * once! The limit is typically 64 bytes.
140 	 */
141 	ich->slave.max_write_size = ctlr.databytes;
142 	ich->speed = max_hz;
143 
144 	return &ich->slave;
145 }
146 
147 void spi_free_slave(struct spi_slave *slave)
148 {
149 	struct ich_spi_slave *ich = to_ich_spi(slave);
150 
151 	free(ich);
152 }
153 
154 /*
155  * Check if this device ID matches one of supported Intel PCH devices.
156  *
157  * Return the ICH version if there is a match, or zero otherwise.
158  */
159 static int get_ich_version(uint16_t device_id)
160 {
161 	if (device_id == PCI_DEVICE_ID_INTEL_TGP_LPC)
162 		return 7;
163 
164 	if ((device_id >= PCI_DEVICE_ID_INTEL_COUGARPOINT_LPC_MIN &&
165 	     device_id <= PCI_DEVICE_ID_INTEL_COUGARPOINT_LPC_MAX) ||
166 	    (device_id >= PCI_DEVICE_ID_INTEL_PANTHERPOINT_LPC_MIN &&
167 	     device_id <= PCI_DEVICE_ID_INTEL_PANTHERPOINT_LPC_MAX))
168 		return 9;
169 
170 	return 0;
171 }
172 
173 /* @return 1 if the SPI flash supports the 33MHz speed */
174 static int ich9_can_do_33mhz(pci_dev_t dev)
175 {
176 	u32 fdod, speed;
177 
178 	/* Observe SPI Descriptor Component Section 0 */
179 	pci_write_config_dword(dev, 0xb0, 0x1000);
180 
181 	/* Extract the Write/Erase SPI Frequency from descriptor */
182 	pci_read_config_dword(dev, 0xb4, &fdod);
183 
184 	/* Bits 23:21 have the fast read clock frequency, 0=20MHz, 1=33MHz */
185 	speed = (fdod >> 21) & 7;
186 
187 	return speed == 1;
188 }
189 
190 static int ich_find_spi_controller(pci_dev_t *devp, int *ich_versionp)
191 {
192 	int last_bus = pci_last_busno();
193 	int bus;
194 
195 	if (last_bus == -1) {
196 		debug("No PCI busses?\n");
197 		return -1;
198 	}
199 
200 	for (bus = 0; bus <= last_bus; bus++) {
201 		uint16_t vendor_id, device_id;
202 		uint32_t ids;
203 		pci_dev_t dev;
204 
205 		dev = PCI_BDF(bus, 31, 0);
206 		pci_read_config_dword(dev, 0, &ids);
207 		vendor_id = ids;
208 		device_id = ids >> 16;
209 
210 		if (vendor_id == PCI_VENDOR_ID_INTEL) {
211 			*devp = dev;
212 			*ich_versionp = get_ich_version(device_id);
213 			return 0;
214 		}
215 	}
216 
217 	debug("ICH SPI: No ICH found.\n");
218 	return -1;
219 }
220 
221 static int ich_init_controller(struct ich_ctlr *ctlr)
222 {
223 	uint8_t *rcrb; /* Root Complex Register Block */
224 	uint32_t rcba; /* Root Complex Base Address */
225 
226 	pci_read_config_dword(ctlr->dev, 0xf0, &rcba);
227 	/* Bits 31-14 are the base address, 13-1 are reserved, 0 is enable. */
228 	rcrb = (uint8_t *)(rcba & 0xffffc000);
229 	if (ctlr->ich_version == 7) {
230 		struct ich7_spi_regs *ich7_spi;
231 
232 		ich7_spi = (struct ich7_spi_regs *)(rcrb + 0x3020);
233 		ctlr->ichspi_lock = ich_readw(&ich7_spi->spis) & SPIS_LOCK;
234 		ctlr->opmenu = ich7_spi->opmenu;
235 		ctlr->menubytes = sizeof(ich7_spi->opmenu);
236 		ctlr->optype = &ich7_spi->optype;
237 		ctlr->addr = &ich7_spi->spia;
238 		ctlr->data = (uint8_t *)ich7_spi->spid;
239 		ctlr->databytes = sizeof(ich7_spi->spid);
240 		ctlr->status = (uint8_t *)&ich7_spi->spis;
241 		ctlr->control = &ich7_spi->spic;
242 		ctlr->bbar = &ich7_spi->bbar;
243 		ctlr->preop = &ich7_spi->preop;
244 		ctlr->base = ich7_spi;
245 	} else if (ctlr->ich_version == 9) {
246 		struct ich9_spi_regs *ich9_spi;
247 
248 		ich9_spi = (struct ich9_spi_regs *)(rcrb + 0x3800);
249 		ctlr->ichspi_lock = ich_readw(&ich9_spi->hsfs) & HSFS_FLOCKDN;
250 		ctlr->opmenu = ich9_spi->opmenu;
251 		ctlr->menubytes = sizeof(ich9_spi->opmenu);
252 		ctlr->optype = &ich9_spi->optype;
253 		ctlr->addr = &ich9_spi->faddr;
254 		ctlr->data = (uint8_t *)ich9_spi->fdata;
255 		ctlr->databytes = sizeof(ich9_spi->fdata);
256 		ctlr->status = &ich9_spi->ssfs;
257 		ctlr->control = (uint16_t *)ich9_spi->ssfc;
258 		ctlr->speed = ich9_spi->ssfc + 2;
259 		ctlr->bbar = &ich9_spi->bbar;
260 		ctlr->preop = &ich9_spi->preop;
261 		ctlr->pr = &ich9_spi->pr[0];
262 		ctlr->base = ich9_spi;
263 	} else {
264 		debug("ICH SPI: Unrecognized ICH version %d.\n",
265 		      ctlr->ich_version);
266 		return -1;
267 	}
268 	debug("ICH SPI: Version %d detected\n", ctlr->ich_version);
269 
270 	/* Work out the maximum speed we can support */
271 	ctlr->max_speed = 20000000;
272 	if (ctlr->ich_version == 9 && ich9_can_do_33mhz(ctlr->dev))
273 		ctlr->max_speed = 33000000;
274 
275 	ich_set_bbar(ctlr, 0);
276 
277 	return 0;
278 }
279 
280 void spi_init(void)
281 {
282 	uint8_t bios_cntl;
283 
284 	if (ich_find_spi_controller(&ctlr.dev, &ctlr.ich_version)) {
285 		printf("ICH SPI: Cannot find device\n");
286 		return;
287 	}
288 
289 	if (ich_init_controller(&ctlr)) {
290 		printf("ICH SPI: Cannot setup controller\n");
291 		return;
292 	}
293 
294 	/*
295 	 * Disable the BIOS write protect so write commands are allowed.  On
296 	 * v9, deassert SMM BIOS Write Protect Disable.
297 	 */
298 	pci_read_config_byte(ctlr.dev, 0xdc, &bios_cntl);
299 	if (ctlr.ich_version == 9)
300 		bios_cntl &= ~(1 << 5);
301 	pci_write_config_byte(ctlr.dev, 0xdc, bios_cntl | 0x1);
302 }
303 
304 int spi_claim_bus(struct spi_slave *slave)
305 {
306 	/* Handled by ICH automatically. */
307 	return 0;
308 }
309 
310 void spi_release_bus(struct spi_slave *slave)
311 {
312 	/* Handled by ICH automatically. */
313 }
314 
315 void spi_cs_activate(struct spi_slave *slave)
316 {
317 	/* Handled by ICH automatically. */
318 }
319 
320 void spi_cs_deactivate(struct spi_slave *slave)
321 {
322 	/* Handled by ICH automatically. */
323 }
324 
325 static inline void spi_use_out(struct spi_trans *trans, unsigned bytes)
326 {
327 	trans->out += bytes;
328 	trans->bytesout -= bytes;
329 }
330 
331 static inline void spi_use_in(struct spi_trans *trans, unsigned bytes)
332 {
333 	trans->in += bytes;
334 	trans->bytesin -= bytes;
335 }
336 
337 static void spi_setup_type(struct spi_trans *trans, int data_bytes)
338 {
339 	trans->type = 0xFF;
340 
341 	/* Try to guess spi type from read/write sizes. */
342 	if (trans->bytesin == 0) {
343 		if (trans->bytesout + data_bytes > 4)
344 			/*
345 			 * If bytesin = 0 and bytesout > 4, we presume this is
346 			 * a write data operation, which is accompanied by an
347 			 * address.
348 			 */
349 			trans->type = SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS;
350 		else
351 			trans->type = SPI_OPCODE_TYPE_WRITE_NO_ADDRESS;
352 		return;
353 	}
354 
355 	if (trans->bytesout == 1) {	/* and bytesin is > 0 */
356 		trans->type = SPI_OPCODE_TYPE_READ_NO_ADDRESS;
357 		return;
358 	}
359 
360 	if (trans->bytesout == 4)	/* and bytesin is > 0 */
361 		trans->type = SPI_OPCODE_TYPE_READ_WITH_ADDRESS;
362 
363 	/* Fast read command is called with 5 bytes instead of 4 */
364 	if (trans->out[0] == SPI_OPCODE_FAST_READ && trans->bytesout == 5) {
365 		trans->type = SPI_OPCODE_TYPE_READ_WITH_ADDRESS;
366 		--trans->bytesout;
367 	}
368 }
369 
370 static int spi_setup_opcode(struct spi_trans *trans)
371 {
372 	uint16_t optypes;
373 	uint8_t opmenu[ctlr.menubytes];
374 
375 	trans->opcode = trans->out[0];
376 	spi_use_out(trans, 1);
377 	if (!ctlr.ichspi_lock) {
378 		/* The lock is off, so just use index 0. */
379 		ich_writeb(trans->opcode, ctlr.opmenu);
380 		optypes = ich_readw(ctlr.optype);
381 		optypes = (optypes & 0xfffc) | (trans->type & 0x3);
382 		ich_writew(optypes, ctlr.optype);
383 		return 0;
384 	} else {
385 		/* The lock is on. See if what we need is on the menu. */
386 		uint8_t optype;
387 		uint16_t opcode_index;
388 
389 		/* Write Enable is handled as atomic prefix */
390 		if (trans->opcode == SPI_OPCODE_WREN)
391 			return 0;
392 
393 		read_reg(ctlr.opmenu, opmenu, sizeof(opmenu));
394 		for (opcode_index = 0; opcode_index < ctlr.menubytes;
395 				opcode_index++) {
396 			if (opmenu[opcode_index] == trans->opcode)
397 				break;
398 		}
399 
400 		if (opcode_index == ctlr.menubytes) {
401 			printf("ICH SPI: Opcode %x not found\n",
402 			       trans->opcode);
403 			return -1;
404 		}
405 
406 		optypes = ich_readw(ctlr.optype);
407 		optype = (optypes >> (opcode_index * 2)) & 0x3;
408 		if (trans->type == SPI_OPCODE_TYPE_WRITE_NO_ADDRESS &&
409 		    optype == SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS &&
410 		    trans->bytesout >= 3) {
411 			/* We guessed wrong earlier. Fix it up. */
412 			trans->type = optype;
413 		}
414 		if (optype != trans->type) {
415 			printf("ICH SPI: Transaction doesn't fit type %d\n",
416 			       optype);
417 			return -1;
418 		}
419 		return opcode_index;
420 	}
421 }
422 
423 static int spi_setup_offset(struct spi_trans *trans)
424 {
425 	/* Separate the SPI address and data. */
426 	switch (trans->type) {
427 	case SPI_OPCODE_TYPE_READ_NO_ADDRESS:
428 	case SPI_OPCODE_TYPE_WRITE_NO_ADDRESS:
429 		return 0;
430 	case SPI_OPCODE_TYPE_READ_WITH_ADDRESS:
431 	case SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS:
432 		trans->offset = ((uint32_t)trans->out[0] << 16) |
433 				((uint32_t)trans->out[1] << 8) |
434 				((uint32_t)trans->out[2] << 0);
435 		spi_use_out(trans, 3);
436 		return 1;
437 	default:
438 		printf("Unrecognized SPI transaction type %#x\n", trans->type);
439 		return -1;
440 	}
441 }
442 
443 /*
444  * Wait for up to 6s til status register bit(s) turn 1 (in case wait_til_set
445  * below is true) or 0. In case the wait was for the bit(s) to set - write
446  * those bits back, which would cause resetting them.
447  *
448  * Return the last read status value on success or -1 on failure.
449  */
450 static int ich_status_poll(u16 bitmask, int wait_til_set)
451 {
452 	int timeout = 600000; /* This will result in 6s */
453 	u16 status = 0;
454 
455 	while (timeout--) {
456 		status = ich_readw(ctlr.status);
457 		if (wait_til_set ^ ((status & bitmask) == 0)) {
458 			if (wait_til_set)
459 				ich_writew((status & bitmask), ctlr.status);
460 			return status;
461 		}
462 		udelay(10);
463 	}
464 
465 	printf("ICH SPI: SCIP timeout, read %x, expected %x\n",
466 	       status, bitmask);
467 	return -1;
468 }
469 
470 /*
471 int spi_xfer(struct spi_slave *slave, const void *dout,
472 		unsigned int bitsout, void *din, unsigned int bitsin)
473 */
474 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
475 		void *din, unsigned long flags)
476 {
477 	struct ich_spi_slave *ich = to_ich_spi(slave);
478 	uint16_t control;
479 	int16_t opcode_index;
480 	int with_address;
481 	int status;
482 	int bytes = bitlen / 8;
483 	struct spi_trans *trans = &ich->trans;
484 	unsigned type = flags & (SPI_XFER_BEGIN | SPI_XFER_END);
485 	int using_cmd = 0;
486 	/* Align read transactions to 64-byte boundaries */
487 	char buff[ctlr.databytes];
488 
489 	/* Ee don't support writing partial bytes. */
490 	if (bitlen % 8) {
491 		debug("ICH SPI: Accessing partial bytes not supported\n");
492 		return -1;
493 	}
494 
495 	/* An empty end transaction can be ignored */
496 	if (type == SPI_XFER_END && !dout && !din)
497 		return 0;
498 
499 	if (type & SPI_XFER_BEGIN)
500 		memset(trans, '\0', sizeof(*trans));
501 
502 	/* Dp we need to come back later to finish it? */
503 	if (dout && type == SPI_XFER_BEGIN) {
504 		if (bytes > ICH_MAX_CMD_LEN) {
505 			debug("ICH SPI: Command length limit exceeded\n");
506 			return -1;
507 		}
508 		memcpy(trans->cmd, dout, bytes);
509 		trans->cmd_len = bytes;
510 		debug("ICH SPI: Saved %d bytes\n", bytes);
511 		return 0;
512 	}
513 
514 	/*
515 	 * We process a 'middle' spi_xfer() call, which has no
516 	 * SPI_XFER_BEGIN/END, as an independent transaction as if it had
517 	 * an end. We therefore repeat the command. This is because ICH
518 	 * seems to have no support for this, or because interest (in digging
519 	 * out the details and creating a special case in the code) is low.
520 	 */
521 	if (trans->cmd_len) {
522 		trans->out = trans->cmd;
523 		trans->bytesout = trans->cmd_len;
524 		using_cmd = 1;
525 		debug("ICH SPI: Using %d bytes\n", trans->cmd_len);
526 	} else {
527 		trans->out = dout;
528 		trans->bytesout = dout ? bytes : 0;
529 	}
530 
531 	trans->in = din;
532 	trans->bytesin = din ? bytes : 0;
533 
534 	/* There has to always at least be an opcode. */
535 	if (!trans->bytesout) {
536 		debug("ICH SPI: No opcode for transfer\n");
537 		return -1;
538 	}
539 
540 	if (ich_status_poll(SPIS_SCIP, 0) == -1)
541 		return -1;
542 
543 	ich_writew(SPIS_CDS | SPIS_FCERR, ctlr.status);
544 
545 	spi_setup_type(trans, using_cmd ? bytes : 0);
546 	opcode_index = spi_setup_opcode(trans);
547 	if (opcode_index < 0)
548 		return -1;
549 	with_address = spi_setup_offset(trans);
550 	if (with_address < 0)
551 		return -1;
552 
553 	if (trans->opcode == SPI_OPCODE_WREN) {
554 		/*
555 		 * Treat Write Enable as Atomic Pre-Op if possible
556 		 * in order to prevent the Management Engine from
557 		 * issuing a transaction between WREN and DATA.
558 		 */
559 		if (!ctlr.ichspi_lock)
560 			ich_writew(trans->opcode, ctlr.preop);
561 		return 0;
562 	}
563 
564 	if (ctlr.speed && ctlr.max_speed >= 33000000) {
565 		int byte;
566 
567 		byte = ich_readb(ctlr.speed);
568 		if (ich->speed >= 33000000)
569 			byte |= SSFC_SCF_33MHZ;
570 		else
571 			byte &= ~SSFC_SCF_33MHZ;
572 		ich_writeb(byte, ctlr.speed);
573 	}
574 
575 	/* See if we have used up the command data */
576 	if (using_cmd && dout && bytes) {
577 		trans->out = dout;
578 		trans->bytesout = bytes;
579 		debug("ICH SPI: Moving to data, %d bytes\n", bytes);
580 	}
581 
582 	/* Preset control fields */
583 	control = ich_readw(ctlr.control);
584 	control &= ~SSFC_RESERVED;
585 	control = SPIC_SCGO | ((opcode_index & 0x07) << 4);
586 
587 	/* Issue atomic preop cycle if needed */
588 	if (ich_readw(ctlr.preop))
589 		control |= SPIC_ACS;
590 
591 	if (!trans->bytesout && !trans->bytesin) {
592 		/* SPI addresses are 24 bit only */
593 		if (with_address)
594 			ich_writel(trans->offset & 0x00FFFFFF, ctlr.addr);
595 
596 		/*
597 		 * This is a 'no data' command (like Write Enable), its
598 		 * bitesout size was 1, decremented to zero while executing
599 		 * spi_setup_opcode() above. Tell the chip to send the
600 		 * command.
601 		 */
602 		ich_writew(control, ctlr.control);
603 
604 		/* wait for the result */
605 		status = ich_status_poll(SPIS_CDS | SPIS_FCERR, 1);
606 		if (status == -1)
607 			return -1;
608 
609 		if (status & SPIS_FCERR) {
610 			debug("ICH SPI: Command transaction error\n");
611 			return -1;
612 		}
613 
614 		return 0;
615 	}
616 
617 	/*
618 	 * Check if this is a write command atempting to transfer more bytes
619 	 * than the controller can handle. Iterations for writes are not
620 	 * supported here because each SPI write command needs to be preceded
621 	 * and followed by other SPI commands, and this sequence is controlled
622 	 * by the SPI chip driver.
623 	 */
624 	if (trans->bytesout > ctlr.databytes) {
625 		debug("ICH SPI: Too much to write. This should be prevented by the driver's max_write_size?\n");
626 		return -1;
627 	}
628 
629 	/*
630 	 * Read or write up to databytes bytes at a time until everything has
631 	 * been sent.
632 	 */
633 	while (trans->bytesout || trans->bytesin) {
634 		uint32_t data_length;
635 		uint32_t aligned_offset;
636 		uint32_t diff;
637 
638 		aligned_offset = trans->offset & ~(ctlr.databytes - 1);
639 		diff = trans->offset - aligned_offset;
640 
641 		/* SPI addresses are 24 bit only */
642 		ich_writel(aligned_offset & 0x00FFFFFF, ctlr.addr);
643 
644 		if (trans->bytesout)
645 			data_length = min(trans->bytesout, ctlr.databytes);
646 		else
647 			data_length = min(trans->bytesin, ctlr.databytes);
648 
649 		/* Program data into FDATA0 to N */
650 		if (trans->bytesout) {
651 			write_reg(trans->out, ctlr.data, data_length);
652 			spi_use_out(trans, data_length);
653 			if (with_address)
654 				trans->offset += data_length;
655 		}
656 
657 		/* Add proper control fields' values */
658 		control &= ~((ctlr.databytes - 1) << 8);
659 		control |= SPIC_DS;
660 		control |= (data_length - 1) << 8;
661 
662 		/* write it */
663 		ich_writew(control, ctlr.control);
664 
665 		/* Wait for Cycle Done Status or Flash Cycle Error. */
666 		status = ich_status_poll(SPIS_CDS | SPIS_FCERR, 1);
667 		if (status == -1)
668 			return -1;
669 
670 		if (status & SPIS_FCERR) {
671 			debug("ICH SPI: Data transaction error\n");
672 			return -1;
673 		}
674 
675 		if (trans->bytesin) {
676 			if (diff) {
677 				data_length -= diff;
678 				read_reg(ctlr.data, buff, ctlr.databytes);
679 				memcpy(trans->in, buff + diff, data_length);
680 			} else {
681 				read_reg(ctlr.data, trans->in, data_length);
682 			}
683 			spi_use_in(trans, data_length);
684 			if (with_address)
685 				trans->offset += data_length;
686 		}
687 	}
688 
689 	/* Clear atomic preop now that xfer is done */
690 	ich_writew(0, ctlr.preop);
691 
692 	return 0;
693 }
694 
695 
696 /*
697  * This uses the SPI controller from the Intel Cougar Point and Panther Point
698  * PCH to write-protect portions of the SPI flash until reboot. The changes
699  * don't actually take effect until the HSFS[FLOCKDN] bit is set, but that's
700  * done elsewhere.
701  */
702 int spi_write_protect_region(uint32_t lower_limit, uint32_t length, int hint)
703 {
704 	uint32_t tmplong;
705 	uint32_t upper_limit;
706 
707 	if (!ctlr.pr) {
708 		printf("%s: operation not supported on this chipset\n",
709 		       __func__);
710 		return -1;
711 	}
712 
713 	if (length == 0 ||
714 	    lower_limit > (0xFFFFFFFFUL - length) + 1 ||
715 	    hint < 0 || hint > 4) {
716 		printf("%s(0x%x, 0x%x, %d): invalid args\n", __func__,
717 		       lower_limit, length, hint);
718 		return -1;
719 	}
720 
721 	upper_limit = lower_limit + length - 1;
722 
723 	/*
724 	 * Determine bits to write, as follows:
725 	 *  31     Write-protection enable (includes erase operation)
726 	 *  30:29  reserved
727 	 *  28:16  Upper Limit (FLA address bits 24:12, with 11:0 == 0xfff)
728 	 *  15     Read-protection enable
729 	 *  14:13  reserved
730 	 *  12:0   Lower Limit (FLA address bits 24:12, with 11:0 == 0x000)
731 	 */
732 	tmplong = 0x80000000 |
733 		((upper_limit & 0x01fff000) << 4) |
734 		((lower_limit & 0x01fff000) >> 12);
735 
736 	printf("%s: writing 0x%08x to %p\n", __func__, tmplong,
737 	       &ctlr.pr[hint]);
738 	ctlr.pr[hint] = tmplong;
739 
740 	return 0;
741 }
742