xref: /openbmc/u-boot/drivers/spi/ich.c (revision 998e121a)
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 	/*
145 	 * ICH 7 SPI controller only supports array read command
146 	 * and byte program command for SST flash
147 	 */
148 	if (ctlr.ich_version == 7) {
149 		ich->slave.op_mode_rx = SPI_OPM_RX_AS;
150 		ich->slave.op_mode_tx = SPI_OPM_TX_BP;
151 	}
152 
153 	return &ich->slave;
154 }
155 
156 void spi_free_slave(struct spi_slave *slave)
157 {
158 	struct ich_spi_slave *ich = to_ich_spi(slave);
159 
160 	free(ich);
161 }
162 
163 /*
164  * Check if this device ID matches one of supported Intel PCH devices.
165  *
166  * Return the ICH version if there is a match, or zero otherwise.
167  */
168 static int get_ich_version(uint16_t device_id)
169 {
170 	if (device_id == PCI_DEVICE_ID_INTEL_TGP_LPC ||
171 	    device_id == PCI_DEVICE_ID_INTEL_ITC_LPC)
172 		return 7;
173 
174 	if ((device_id >= PCI_DEVICE_ID_INTEL_COUGARPOINT_LPC_MIN &&
175 	     device_id <= PCI_DEVICE_ID_INTEL_COUGARPOINT_LPC_MAX) ||
176 	    (device_id >= PCI_DEVICE_ID_INTEL_PANTHERPOINT_LPC_MIN &&
177 	     device_id <= PCI_DEVICE_ID_INTEL_PANTHERPOINT_LPC_MAX))
178 		return 9;
179 
180 	return 0;
181 }
182 
183 /* @return 1 if the SPI flash supports the 33MHz speed */
184 static int ich9_can_do_33mhz(pci_dev_t dev)
185 {
186 	u32 fdod, speed;
187 
188 	/* Observe SPI Descriptor Component Section 0 */
189 	pci_write_config_dword(dev, 0xb0, 0x1000);
190 
191 	/* Extract the Write/Erase SPI Frequency from descriptor */
192 	pci_read_config_dword(dev, 0xb4, &fdod);
193 
194 	/* Bits 23:21 have the fast read clock frequency, 0=20MHz, 1=33MHz */
195 	speed = (fdod >> 21) & 7;
196 
197 	return speed == 1;
198 }
199 
200 static int ich_find_spi_controller(pci_dev_t *devp, int *ich_versionp)
201 {
202 	int last_bus = pci_last_busno();
203 	int bus;
204 
205 	if (last_bus == -1) {
206 		debug("No PCI busses?\n");
207 		return -1;
208 	}
209 
210 	for (bus = 0; bus <= last_bus; bus++) {
211 		uint16_t vendor_id, device_id;
212 		uint32_t ids;
213 		pci_dev_t dev;
214 
215 		dev = PCI_BDF(bus, 31, 0);
216 		pci_read_config_dword(dev, 0, &ids);
217 		vendor_id = ids;
218 		device_id = ids >> 16;
219 
220 		if (vendor_id == PCI_VENDOR_ID_INTEL) {
221 			*devp = dev;
222 			*ich_versionp = get_ich_version(device_id);
223 			return 0;
224 		}
225 	}
226 
227 	debug("ICH SPI: No ICH found.\n");
228 	return -1;
229 }
230 
231 static int ich_init_controller(struct ich_ctlr *ctlr)
232 {
233 	uint8_t *rcrb; /* Root Complex Register Block */
234 	uint32_t rcba; /* Root Complex Base Address */
235 
236 	pci_read_config_dword(ctlr->dev, 0xf0, &rcba);
237 	/* Bits 31-14 are the base address, 13-1 are reserved, 0 is enable. */
238 	rcrb = (uint8_t *)(rcba & 0xffffc000);
239 	if (ctlr->ich_version == 7) {
240 		struct ich7_spi_regs *ich7_spi;
241 
242 		ich7_spi = (struct ich7_spi_regs *)(rcrb + 0x3020);
243 		ctlr->ichspi_lock = ich_readw(&ich7_spi->spis) & SPIS_LOCK;
244 		ctlr->opmenu = ich7_spi->opmenu;
245 		ctlr->menubytes = sizeof(ich7_spi->opmenu);
246 		ctlr->optype = &ich7_spi->optype;
247 		ctlr->addr = &ich7_spi->spia;
248 		ctlr->data = (uint8_t *)ich7_spi->spid;
249 		ctlr->databytes = sizeof(ich7_spi->spid);
250 		ctlr->status = (uint8_t *)&ich7_spi->spis;
251 		ctlr->control = &ich7_spi->spic;
252 		ctlr->bbar = &ich7_spi->bbar;
253 		ctlr->preop = &ich7_spi->preop;
254 		ctlr->base = ich7_spi;
255 	} else if (ctlr->ich_version == 9) {
256 		struct ich9_spi_regs *ich9_spi;
257 
258 		ich9_spi = (struct ich9_spi_regs *)(rcrb + 0x3800);
259 		ctlr->ichspi_lock = ich_readw(&ich9_spi->hsfs) & HSFS_FLOCKDN;
260 		ctlr->opmenu = ich9_spi->opmenu;
261 		ctlr->menubytes = sizeof(ich9_spi->opmenu);
262 		ctlr->optype = &ich9_spi->optype;
263 		ctlr->addr = &ich9_spi->faddr;
264 		ctlr->data = (uint8_t *)ich9_spi->fdata;
265 		ctlr->databytes = sizeof(ich9_spi->fdata);
266 		ctlr->status = &ich9_spi->ssfs;
267 		ctlr->control = (uint16_t *)ich9_spi->ssfc;
268 		ctlr->speed = ich9_spi->ssfc + 2;
269 		ctlr->bbar = &ich9_spi->bbar;
270 		ctlr->preop = &ich9_spi->preop;
271 		ctlr->pr = &ich9_spi->pr[0];
272 		ctlr->base = ich9_spi;
273 	} else {
274 		debug("ICH SPI: Unrecognized ICH version %d.\n",
275 		      ctlr->ich_version);
276 		return -1;
277 	}
278 	debug("ICH SPI: Version %d detected\n", ctlr->ich_version);
279 
280 	/* Work out the maximum speed we can support */
281 	ctlr->max_speed = 20000000;
282 	if (ctlr->ich_version == 9 && ich9_can_do_33mhz(ctlr->dev))
283 		ctlr->max_speed = 33000000;
284 
285 	ich_set_bbar(ctlr, 0);
286 
287 	return 0;
288 }
289 
290 void spi_init(void)
291 {
292 	uint8_t bios_cntl;
293 
294 	if (ich_find_spi_controller(&ctlr.dev, &ctlr.ich_version)) {
295 		printf("ICH SPI: Cannot find device\n");
296 		return;
297 	}
298 
299 	if (ich_init_controller(&ctlr)) {
300 		printf("ICH SPI: Cannot setup controller\n");
301 		return;
302 	}
303 
304 	/*
305 	 * Disable the BIOS write protect so write commands are allowed.  On
306 	 * v9, deassert SMM BIOS Write Protect Disable.
307 	 */
308 	pci_read_config_byte(ctlr.dev, 0xdc, &bios_cntl);
309 	if (ctlr.ich_version == 9)
310 		bios_cntl &= ~(1 << 5);
311 	pci_write_config_byte(ctlr.dev, 0xdc, bios_cntl | 0x1);
312 }
313 
314 int spi_claim_bus(struct spi_slave *slave)
315 {
316 	/* Handled by ICH automatically. */
317 	return 0;
318 }
319 
320 void spi_release_bus(struct spi_slave *slave)
321 {
322 	/* Handled by ICH automatically. */
323 }
324 
325 void spi_cs_activate(struct spi_slave *slave)
326 {
327 	/* Handled by ICH automatically. */
328 }
329 
330 void spi_cs_deactivate(struct spi_slave *slave)
331 {
332 	/* Handled by ICH automatically. */
333 }
334 
335 static inline void spi_use_out(struct spi_trans *trans, unsigned bytes)
336 {
337 	trans->out += bytes;
338 	trans->bytesout -= bytes;
339 }
340 
341 static inline void spi_use_in(struct spi_trans *trans, unsigned bytes)
342 {
343 	trans->in += bytes;
344 	trans->bytesin -= bytes;
345 }
346 
347 static void spi_setup_type(struct spi_trans *trans, int data_bytes)
348 {
349 	trans->type = 0xFF;
350 
351 	/* Try to guess spi type from read/write sizes. */
352 	if (trans->bytesin == 0) {
353 		if (trans->bytesout + data_bytes > 4)
354 			/*
355 			 * If bytesin = 0 and bytesout > 4, we presume this is
356 			 * a write data operation, which is accompanied by an
357 			 * address.
358 			 */
359 			trans->type = SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS;
360 		else
361 			trans->type = SPI_OPCODE_TYPE_WRITE_NO_ADDRESS;
362 		return;
363 	}
364 
365 	if (trans->bytesout == 1) {	/* and bytesin is > 0 */
366 		trans->type = SPI_OPCODE_TYPE_READ_NO_ADDRESS;
367 		return;
368 	}
369 
370 	if (trans->bytesout == 4)	/* and bytesin is > 0 */
371 		trans->type = SPI_OPCODE_TYPE_READ_WITH_ADDRESS;
372 
373 	/* Fast read command is called with 5 bytes instead of 4 */
374 	if (trans->out[0] == SPI_OPCODE_FAST_READ && trans->bytesout == 5) {
375 		trans->type = SPI_OPCODE_TYPE_READ_WITH_ADDRESS;
376 		--trans->bytesout;
377 	}
378 }
379 
380 static int spi_setup_opcode(struct spi_trans *trans)
381 {
382 	uint16_t optypes;
383 	uint8_t opmenu[ctlr.menubytes];
384 
385 	trans->opcode = trans->out[0];
386 	spi_use_out(trans, 1);
387 	if (!ctlr.ichspi_lock) {
388 		/* The lock is off, so just use index 0. */
389 		ich_writeb(trans->opcode, ctlr.opmenu);
390 		optypes = ich_readw(ctlr.optype);
391 		optypes = (optypes & 0xfffc) | (trans->type & 0x3);
392 		ich_writew(optypes, ctlr.optype);
393 		return 0;
394 	} else {
395 		/* The lock is on. See if what we need is on the menu. */
396 		uint8_t optype;
397 		uint16_t opcode_index;
398 
399 		/* Write Enable is handled as atomic prefix */
400 		if (trans->opcode == SPI_OPCODE_WREN)
401 			return 0;
402 
403 		read_reg(ctlr.opmenu, opmenu, sizeof(opmenu));
404 		for (opcode_index = 0; opcode_index < ctlr.menubytes;
405 				opcode_index++) {
406 			if (opmenu[opcode_index] == trans->opcode)
407 				break;
408 		}
409 
410 		if (opcode_index == ctlr.menubytes) {
411 			printf("ICH SPI: Opcode %x not found\n",
412 			       trans->opcode);
413 			return -1;
414 		}
415 
416 		optypes = ich_readw(ctlr.optype);
417 		optype = (optypes >> (opcode_index * 2)) & 0x3;
418 		if (trans->type == SPI_OPCODE_TYPE_WRITE_NO_ADDRESS &&
419 		    optype == SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS &&
420 		    trans->bytesout >= 3) {
421 			/* We guessed wrong earlier. Fix it up. */
422 			trans->type = optype;
423 		}
424 		if (optype != trans->type) {
425 			printf("ICH SPI: Transaction doesn't fit type %d\n",
426 			       optype);
427 			return -1;
428 		}
429 		return opcode_index;
430 	}
431 }
432 
433 static int spi_setup_offset(struct spi_trans *trans)
434 {
435 	/* Separate the SPI address and data. */
436 	switch (trans->type) {
437 	case SPI_OPCODE_TYPE_READ_NO_ADDRESS:
438 	case SPI_OPCODE_TYPE_WRITE_NO_ADDRESS:
439 		return 0;
440 	case SPI_OPCODE_TYPE_READ_WITH_ADDRESS:
441 	case SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS:
442 		trans->offset = ((uint32_t)trans->out[0] << 16) |
443 				((uint32_t)trans->out[1] << 8) |
444 				((uint32_t)trans->out[2] << 0);
445 		spi_use_out(trans, 3);
446 		return 1;
447 	default:
448 		printf("Unrecognized SPI transaction type %#x\n", trans->type);
449 		return -1;
450 	}
451 }
452 
453 /*
454  * Wait for up to 6s til status register bit(s) turn 1 (in case wait_til_set
455  * below is true) or 0. In case the wait was for the bit(s) to set - write
456  * those bits back, which would cause resetting them.
457  *
458  * Return the last read status value on success or -1 on failure.
459  */
460 static int ich_status_poll(u16 bitmask, int wait_til_set)
461 {
462 	int timeout = 600000; /* This will result in 6s */
463 	u16 status = 0;
464 
465 	while (timeout--) {
466 		status = ich_readw(ctlr.status);
467 		if (wait_til_set ^ ((status & bitmask) == 0)) {
468 			if (wait_til_set)
469 				ich_writew((status & bitmask), ctlr.status);
470 			return status;
471 		}
472 		udelay(10);
473 	}
474 
475 	printf("ICH SPI: SCIP timeout, read %x, expected %x\n",
476 	       status, bitmask);
477 	return -1;
478 }
479 
480 /*
481 int spi_xfer(struct spi_slave *slave, const void *dout,
482 		unsigned int bitsout, void *din, unsigned int bitsin)
483 */
484 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
485 		void *din, unsigned long flags)
486 {
487 	struct ich_spi_slave *ich = to_ich_spi(slave);
488 	uint16_t control;
489 	int16_t opcode_index;
490 	int with_address;
491 	int status;
492 	int bytes = bitlen / 8;
493 	struct spi_trans *trans = &ich->trans;
494 	unsigned type = flags & (SPI_XFER_BEGIN | SPI_XFER_END);
495 	int using_cmd = 0;
496 
497 	/* Ee don't support writing partial bytes. */
498 	if (bitlen % 8) {
499 		debug("ICH SPI: Accessing partial bytes not supported\n");
500 		return -1;
501 	}
502 
503 	/* An empty end transaction can be ignored */
504 	if (type == SPI_XFER_END && !dout && !din)
505 		return 0;
506 
507 	if (type & SPI_XFER_BEGIN)
508 		memset(trans, '\0', sizeof(*trans));
509 
510 	/* Dp we need to come back later to finish it? */
511 	if (dout && type == SPI_XFER_BEGIN) {
512 		if (bytes > ICH_MAX_CMD_LEN) {
513 			debug("ICH SPI: Command length limit exceeded\n");
514 			return -1;
515 		}
516 		memcpy(trans->cmd, dout, bytes);
517 		trans->cmd_len = bytes;
518 		debug("ICH SPI: Saved %d bytes\n", bytes);
519 		return 0;
520 	}
521 
522 	/*
523 	 * We process a 'middle' spi_xfer() call, which has no
524 	 * SPI_XFER_BEGIN/END, as an independent transaction as if it had
525 	 * an end. We therefore repeat the command. This is because ICH
526 	 * seems to have no support for this, or because interest (in digging
527 	 * out the details and creating a special case in the code) is low.
528 	 */
529 	if (trans->cmd_len) {
530 		trans->out = trans->cmd;
531 		trans->bytesout = trans->cmd_len;
532 		using_cmd = 1;
533 		debug("ICH SPI: Using %d bytes\n", trans->cmd_len);
534 	} else {
535 		trans->out = dout;
536 		trans->bytesout = dout ? bytes : 0;
537 	}
538 
539 	trans->in = din;
540 	trans->bytesin = din ? bytes : 0;
541 
542 	/* There has to always at least be an opcode. */
543 	if (!trans->bytesout) {
544 		debug("ICH SPI: No opcode for transfer\n");
545 		return -1;
546 	}
547 
548 	if (ich_status_poll(SPIS_SCIP, 0) == -1)
549 		return -1;
550 
551 	ich_writew(SPIS_CDS | SPIS_FCERR, ctlr.status);
552 
553 	spi_setup_type(trans, using_cmd ? bytes : 0);
554 	opcode_index = spi_setup_opcode(trans);
555 	if (opcode_index < 0)
556 		return -1;
557 	with_address = spi_setup_offset(trans);
558 	if (with_address < 0)
559 		return -1;
560 
561 	if (trans->opcode == SPI_OPCODE_WREN) {
562 		/*
563 		 * Treat Write Enable as Atomic Pre-Op if possible
564 		 * in order to prevent the Management Engine from
565 		 * issuing a transaction between WREN and DATA.
566 		 */
567 		if (!ctlr.ichspi_lock)
568 			ich_writew(trans->opcode, ctlr.preop);
569 		return 0;
570 	}
571 
572 	if (ctlr.speed && ctlr.max_speed >= 33000000) {
573 		int byte;
574 
575 		byte = ich_readb(ctlr.speed);
576 		if (ich->speed >= 33000000)
577 			byte |= SSFC_SCF_33MHZ;
578 		else
579 			byte &= ~SSFC_SCF_33MHZ;
580 		ich_writeb(byte, ctlr.speed);
581 	}
582 
583 	/* See if we have used up the command data */
584 	if (using_cmd && dout && bytes) {
585 		trans->out = dout;
586 		trans->bytesout = bytes;
587 		debug("ICH SPI: Moving to data, %d bytes\n", bytes);
588 	}
589 
590 	/* Preset control fields */
591 	control = ich_readw(ctlr.control);
592 	control &= ~SSFC_RESERVED;
593 	control = SPIC_SCGO | ((opcode_index & 0x07) << 4);
594 
595 	/* Issue atomic preop cycle if needed */
596 	if (ich_readw(ctlr.preop))
597 		control |= SPIC_ACS;
598 
599 	if (!trans->bytesout && !trans->bytesin) {
600 		/* SPI addresses are 24 bit only */
601 		if (with_address)
602 			ich_writel(trans->offset & 0x00FFFFFF, ctlr.addr);
603 
604 		/*
605 		 * This is a 'no data' command (like Write Enable), its
606 		 * bitesout size was 1, decremented to zero while executing
607 		 * spi_setup_opcode() above. Tell the chip to send the
608 		 * command.
609 		 */
610 		ich_writew(control, ctlr.control);
611 
612 		/* wait for the result */
613 		status = ich_status_poll(SPIS_CDS | SPIS_FCERR, 1);
614 		if (status == -1)
615 			return -1;
616 
617 		if (status & SPIS_FCERR) {
618 			debug("ICH SPI: Command transaction error\n");
619 			return -1;
620 		}
621 
622 		return 0;
623 	}
624 
625 	/*
626 	 * Check if this is a write command atempting to transfer more bytes
627 	 * than the controller can handle. Iterations for writes are not
628 	 * supported here because each SPI write command needs to be preceded
629 	 * and followed by other SPI commands, and this sequence is controlled
630 	 * by the SPI chip driver.
631 	 */
632 	if (trans->bytesout > ctlr.databytes) {
633 		debug("ICH SPI: Too much to write. This should be prevented by the driver's max_write_size?\n");
634 		return -1;
635 	}
636 
637 	/*
638 	 * Read or write up to databytes bytes at a time until everything has
639 	 * been sent.
640 	 */
641 	while (trans->bytesout || trans->bytesin) {
642 		uint32_t data_length;
643 
644 		/* SPI addresses are 24 bit only */
645 		ich_writel(trans->offset & 0x00FFFFFF, ctlr.addr);
646 
647 		if (trans->bytesout)
648 			data_length = min(trans->bytesout, ctlr.databytes);
649 		else
650 			data_length = min(trans->bytesin, ctlr.databytes);
651 
652 		/* Program data into FDATA0 to N */
653 		if (trans->bytesout) {
654 			write_reg(trans->out, ctlr.data, data_length);
655 			spi_use_out(trans, data_length);
656 			if (with_address)
657 				trans->offset += data_length;
658 		}
659 
660 		/* Add proper control fields' values */
661 		control &= ~((ctlr.databytes - 1) << 8);
662 		control |= SPIC_DS;
663 		control |= (data_length - 1) << 8;
664 
665 		/* write it */
666 		ich_writew(control, ctlr.control);
667 
668 		/* Wait for Cycle Done Status or Flash Cycle Error. */
669 		status = ich_status_poll(SPIS_CDS | SPIS_FCERR, 1);
670 		if (status == -1)
671 			return -1;
672 
673 		if (status & SPIS_FCERR) {
674 			debug("ICH SPI: Data transaction error\n");
675 			return -1;
676 		}
677 
678 		if (trans->bytesin) {
679 			read_reg(ctlr.data, trans->in, data_length);
680 			spi_use_in(trans, data_length);
681 			if (with_address)
682 				trans->offset += data_length;
683 		}
684 	}
685 
686 	/* Clear atomic preop now that xfer is done */
687 	ich_writew(0, ctlr.preop);
688 
689 	return 0;
690 }
691 
692 
693 /*
694  * This uses the SPI controller from the Intel Cougar Point and Panther Point
695  * PCH to write-protect portions of the SPI flash until reboot. The changes
696  * don't actually take effect until the HSFS[FLOCKDN] bit is set, but that's
697  * done elsewhere.
698  */
699 int spi_write_protect_region(uint32_t lower_limit, uint32_t length, int hint)
700 {
701 	uint32_t tmplong;
702 	uint32_t upper_limit;
703 
704 	if (!ctlr.pr) {
705 		printf("%s: operation not supported on this chipset\n",
706 		       __func__);
707 		return -1;
708 	}
709 
710 	if (length == 0 ||
711 	    lower_limit > (0xFFFFFFFFUL - length) + 1 ||
712 	    hint < 0 || hint > 4) {
713 		printf("%s(0x%x, 0x%x, %d): invalid args\n", __func__,
714 		       lower_limit, length, hint);
715 		return -1;
716 	}
717 
718 	upper_limit = lower_limit + length - 1;
719 
720 	/*
721 	 * Determine bits to write, as follows:
722 	 *  31     Write-protection enable (includes erase operation)
723 	 *  30:29  reserved
724 	 *  28:16  Upper Limit (FLA address bits 24:12, with 11:0 == 0xfff)
725 	 *  15     Read-protection enable
726 	 *  14:13  reserved
727 	 *  12:0   Lower Limit (FLA address bits 24:12, with 11:0 == 0x000)
728 	 */
729 	tmplong = 0x80000000 |
730 		((upper_limit & 0x01fff000) << 4) |
731 		((lower_limit & 0x01fff000) >> 12);
732 
733 	printf("%s: writing 0x%08x to %p\n", __func__, tmplong,
734 	       &ctlr.pr[hint]);
735 	ctlr.pr[hint] = tmplong;
736 
737 	return 0;
738 }
739