xref: /openbmc/u-boot/drivers/spi/ich.c (revision 3a1a18ff)
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 <errno.h>
11 #include <malloc.h>
12 #include <spi.h>
13 #include <pci.h>
14 #include <pci_ids.h>
15 #include <asm/io.h>
16 
17 #include "ich.h"
18 
19 #define SPI_OPCODE_WREN      0x06
20 #define SPI_OPCODE_FAST_READ 0x0b
21 
22 struct ich_ctlr {
23 	pci_dev_t dev;		/* PCI device number */
24 	int ich_version;	/* Controller version, 7 or 9 */
25 	bool use_sbase;		/* Use SBASE instead of RCB */
26 	int ichspi_lock;
27 	int locked;
28 	uint8_t *opmenu;
29 	int menubytes;
30 	void *base;		/* Base of register set */
31 	uint16_t *preop;
32 	uint16_t *optype;
33 	uint32_t *addr;
34 	uint8_t *data;
35 	unsigned databytes;
36 	uint8_t *status;
37 	uint16_t *control;
38 	uint32_t *bbar;
39 	uint32_t *pr;		/* only for ich9 */
40 	uint8_t *speed;		/* pointer to speed control */
41 	ulong max_speed;	/* Maximum bus speed in MHz */
42 };
43 
44 struct ich_ctlr ctlr;
45 
46 static inline struct ich_spi_slave *to_ich_spi(struct spi_slave *slave)
47 {
48 	return container_of(slave, struct ich_spi_slave, slave);
49 }
50 
51 static unsigned int ich_reg(const void *addr)
52 {
53 	return (unsigned)(addr - ctlr.base) & 0xffff;
54 }
55 
56 static u8 ich_readb(const void *addr)
57 {
58 	u8 value = readb(addr);
59 
60 	debug("read %2.2x from %4.4x\n", value, ich_reg(addr));
61 
62 	return value;
63 }
64 
65 static u16 ich_readw(const void *addr)
66 {
67 	u16 value = readw(addr);
68 
69 	debug("read %4.4x from %4.4x\n", value, ich_reg(addr));
70 
71 	return value;
72 }
73 
74 static u32 ich_readl(const void *addr)
75 {
76 	u32 value = readl(addr);
77 
78 	debug("read %8.8x from %4.4x\n", value, ich_reg(addr));
79 
80 	return value;
81 }
82 
83 static void ich_writeb(u8 value, void *addr)
84 {
85 	writeb(value, addr);
86 	debug("wrote %2.2x to %4.4x\n", value, ich_reg(addr));
87 }
88 
89 static void ich_writew(u16 value, void *addr)
90 {
91 	writew(value, addr);
92 	debug("wrote %4.4x to %4.4x\n", value, ich_reg(addr));
93 }
94 
95 static void ich_writel(u32 value, void *addr)
96 {
97 	writel(value, addr);
98 	debug("wrote %8.8x to %4.4x\n", value, ich_reg(addr));
99 }
100 
101 static void write_reg(const void *value, void *dest, uint32_t size)
102 {
103 	memcpy_toio(dest, value, size);
104 }
105 
106 static void read_reg(const void *src, void *value, uint32_t size)
107 {
108 	memcpy_fromio(value, src, size);
109 }
110 
111 static void ich_set_bbar(struct ich_ctlr *ctlr, uint32_t minaddr)
112 {
113 	const uint32_t bbar_mask = 0x00ffff00;
114 	uint32_t ichspi_bbar;
115 
116 	minaddr &= bbar_mask;
117 	ichspi_bbar = ich_readl(ctlr->bbar) & ~bbar_mask;
118 	ichspi_bbar |= minaddr;
119 	ich_writel(ichspi_bbar, ctlr->bbar);
120 }
121 
122 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
123 {
124 	puts("spi_cs_is_valid used but not implemented\n");
125 	return 0;
126 }
127 
128 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
129 		unsigned int max_hz, unsigned int mode)
130 {
131 	struct ich_spi_slave *ich;
132 
133 	ich = spi_alloc_slave(struct ich_spi_slave, bus, cs);
134 	if (!ich) {
135 		puts("ICH SPI: Out of memory\n");
136 		return NULL;
137 	}
138 
139 	/*
140 	 * Yes this controller can only write a small number of bytes at
141 	 * once! The limit is typically 64 bytes.
142 	 */
143 	ich->slave.max_write_size = ctlr.databytes;
144 	ich->speed = max_hz;
145 
146 	/*
147 	 * ICH 7 SPI controller only supports array read command
148 	 * and byte program command for SST flash
149 	 */
150 	if (ctlr.ich_version == 7 || ctlr.use_sbase) {
151 		ich->slave.op_mode_rx = SPI_OPM_RX_AS;
152 		ich->slave.op_mode_tx = SPI_OPM_TX_BP;
153 	}
154 
155 	return &ich->slave;
156 }
157 
158 struct spi_slave *spi_setup_slave_fdt(const void *blob, int slave_node,
159 				      int spi_node)
160 {
161 	/* We only support a single SPI at present */
162 	return spi_setup_slave(0, 0, 20000000, 0);
163 }
164 
165 void spi_free_slave(struct spi_slave *slave)
166 {
167 	struct ich_spi_slave *ich = to_ich_spi(slave);
168 
169 	free(ich);
170 }
171 
172 /*
173  * Check if this device ID matches one of supported Intel PCH devices.
174  *
175  * Return the ICH version if there is a match, or zero otherwise.
176  */
177 static int get_ich_version(uint16_t device_id)
178 {
179 	if (device_id == PCI_DEVICE_ID_INTEL_TGP_LPC ||
180 	    device_id == PCI_DEVICE_ID_INTEL_ITC_LPC)
181 		return 7;
182 
183 	if ((device_id >= PCI_DEVICE_ID_INTEL_COUGARPOINT_LPC_MIN &&
184 	     device_id <= PCI_DEVICE_ID_INTEL_COUGARPOINT_LPC_MAX) ||
185 	    (device_id >= PCI_DEVICE_ID_INTEL_PANTHERPOINT_LPC_MIN &&
186 	     device_id <= PCI_DEVICE_ID_INTEL_PANTHERPOINT_LPC_MAX) ||
187 	    device_id == PCI_DEVICE_ID_INTEL_VALLEYVIEW_LPC)
188 		return 9;
189 
190 	return 0;
191 }
192 
193 /* @return 1 if the SPI flash supports the 33MHz speed */
194 static int ich9_can_do_33mhz(pci_dev_t dev)
195 {
196 	u32 fdod, speed;
197 
198 	/* Observe SPI Descriptor Component Section 0 */
199 	pci_write_config_dword(dev, 0xb0, 0x1000);
200 
201 	/* Extract the Write/Erase SPI Frequency from descriptor */
202 	pci_read_config_dword(dev, 0xb4, &fdod);
203 
204 	/* Bits 23:21 have the fast read clock frequency, 0=20MHz, 1=33MHz */
205 	speed = (fdod >> 21) & 7;
206 
207 	return speed == 1;
208 }
209 
210 static int ich_find_spi_controller(struct ich_ctlr *ich)
211 {
212 	int last_bus = pci_last_busno();
213 	int bus;
214 
215 	if (last_bus == -1) {
216 		debug("No PCI busses?\n");
217 		return -ENODEV;
218 	}
219 
220 	for (bus = 0; bus <= last_bus; bus++) {
221 		uint16_t vendor_id, device_id;
222 		uint32_t ids;
223 		pci_dev_t dev;
224 
225 		dev = PCI_BDF(bus, 31, 0);
226 		pci_read_config_dword(dev, 0, &ids);
227 		vendor_id = ids;
228 		device_id = ids >> 16;
229 
230 		if (vendor_id == PCI_VENDOR_ID_INTEL) {
231 			ich->dev = dev;
232 			ich->ich_version = get_ich_version(device_id);
233 			if (device_id == PCI_DEVICE_ID_INTEL_VALLEYVIEW_LPC)
234 				ich->use_sbase = true;
235 			return ich->ich_version == 0 ? -ENODEV : 0;
236 		}
237 	}
238 
239 	debug("ICH SPI: No ICH found.\n");
240 	return -ENODEV;
241 }
242 
243 static int ich_init_controller(struct ich_ctlr *ctlr)
244 {
245 	uint8_t *rcrb; /* Root Complex Register Block */
246 	uint32_t rcba; /* Root Complex Base Address */
247 	uint32_t sbase_addr;
248 	uint8_t *sbase;
249 
250 	pci_read_config_dword(ctlr->dev, 0xf0, &rcba);
251 	/* Bits 31-14 are the base address, 13-1 are reserved, 0 is enable. */
252 	rcrb = (uint8_t *)(rcba & 0xffffc000);
253 
254 	/* SBASE is similar */
255 	pci_read_config_dword(ctlr->dev, 0x54, &sbase_addr);
256 	sbase = (uint8_t *)(sbase_addr & 0xfffffe00);
257 
258 	if (ctlr->ich_version == 7) {
259 		struct ich7_spi_regs *ich7_spi;
260 
261 		ich7_spi = (struct ich7_spi_regs *)(rcrb + 0x3020);
262 		ctlr->ichspi_lock = ich_readw(&ich7_spi->spis) & SPIS_LOCK;
263 		ctlr->opmenu = ich7_spi->opmenu;
264 		ctlr->menubytes = sizeof(ich7_spi->opmenu);
265 		ctlr->optype = &ich7_spi->optype;
266 		ctlr->addr = &ich7_spi->spia;
267 		ctlr->data = (uint8_t *)ich7_spi->spid;
268 		ctlr->databytes = sizeof(ich7_spi->spid);
269 		ctlr->status = (uint8_t *)&ich7_spi->spis;
270 		ctlr->control = &ich7_spi->spic;
271 		ctlr->bbar = &ich7_spi->bbar;
272 		ctlr->preop = &ich7_spi->preop;
273 		ctlr->base = ich7_spi;
274 	} else if (ctlr->ich_version == 9) {
275 		struct ich9_spi_regs *ich9_spi;
276 
277 		if (ctlr->use_sbase)
278 			ich9_spi = (struct ich9_spi_regs *)sbase;
279 		else
280 			ich9_spi = (struct ich9_spi_regs *)(rcrb + 0x3800);
281 		ctlr->ichspi_lock = ich_readw(&ich9_spi->hsfs) & HSFS_FLOCKDN;
282 		ctlr->opmenu = ich9_spi->opmenu;
283 		ctlr->menubytes = sizeof(ich9_spi->opmenu);
284 		ctlr->optype = &ich9_spi->optype;
285 		ctlr->addr = &ich9_spi->faddr;
286 		ctlr->data = (uint8_t *)ich9_spi->fdata;
287 		ctlr->databytes = sizeof(ich9_spi->fdata);
288 		ctlr->status = &ich9_spi->ssfs;
289 		ctlr->control = (uint16_t *)ich9_spi->ssfc;
290 		ctlr->speed = ich9_spi->ssfc + 2;
291 		ctlr->bbar = &ich9_spi->bbar;
292 		ctlr->preop = &ich9_spi->preop;
293 		ctlr->pr = &ich9_spi->pr[0];
294 		ctlr->base = ich9_spi;
295 	} else {
296 		debug("ICH SPI: Unrecognized ICH version %d.\n",
297 		      ctlr->ich_version);
298 		return -1;
299 	}
300 
301 	/* Work out the maximum speed we can support */
302 	ctlr->max_speed = 20000000;
303 	if (ctlr->ich_version == 9 && ich9_can_do_33mhz(ctlr->dev))
304 		ctlr->max_speed = 33000000;
305 	debug("ICH SPI: Version %d detected at %p, speed %ld\n",
306 	      ctlr->ich_version, ctlr->base, ctlr->max_speed);
307 
308 	ich_set_bbar(ctlr, 0);
309 
310 	return 0;
311 }
312 
313 void spi_init(void)
314 {
315 	uint8_t bios_cntl;
316 
317 	if (ich_find_spi_controller(&ctlr)) {
318 		printf("ICH SPI: Cannot find device\n");
319 		return;
320 	}
321 
322 	if (ich_init_controller(&ctlr)) {
323 		printf("ICH SPI: Cannot setup controller\n");
324 		return;
325 	}
326 
327 	/*
328 	 * Disable the BIOS write protect so write commands are allowed.  On
329 	 * v9, deassert SMM BIOS Write Protect Disable.
330 	 */
331 	if (ctlr.use_sbase) {
332 		struct ich9_spi_regs *ich9_spi;
333 
334 		ich9_spi = (struct ich9_spi_regs *)ctlr.base;
335 		bios_cntl = ich_readb(&ich9_spi->bcr);
336 		bios_cntl &= ~(1 << 5);	/* clear Enable InSMM_STS (EISS) */
337 		bios_cntl |= 1;		/* Write Protect Disable (WPD) */
338 		ich_writeb(bios_cntl, &ich9_spi->bcr);
339 	} else {
340 		pci_read_config_byte(ctlr.dev, 0xdc, &bios_cntl);
341 		if (ctlr.ich_version == 9)
342 			bios_cntl &= ~(1 << 5);
343 		pci_write_config_byte(ctlr.dev, 0xdc, bios_cntl | 0x1);
344 	}
345 }
346 
347 int spi_claim_bus(struct spi_slave *slave)
348 {
349 	/* Handled by ICH automatically. */
350 	return 0;
351 }
352 
353 void spi_release_bus(struct spi_slave *slave)
354 {
355 	/* Handled by ICH automatically. */
356 }
357 
358 void spi_cs_activate(struct spi_slave *slave)
359 {
360 	/* Handled by ICH automatically. */
361 }
362 
363 void spi_cs_deactivate(struct spi_slave *slave)
364 {
365 	/* Handled by ICH automatically. */
366 }
367 
368 static inline void spi_use_out(struct spi_trans *trans, unsigned bytes)
369 {
370 	trans->out += bytes;
371 	trans->bytesout -= bytes;
372 }
373 
374 static inline void spi_use_in(struct spi_trans *trans, unsigned bytes)
375 {
376 	trans->in += bytes;
377 	trans->bytesin -= bytes;
378 }
379 
380 static void spi_setup_type(struct spi_trans *trans, int data_bytes)
381 {
382 	trans->type = 0xFF;
383 
384 	/* Try to guess spi type from read/write sizes. */
385 	if (trans->bytesin == 0) {
386 		if (trans->bytesout + data_bytes > 4)
387 			/*
388 			 * If bytesin = 0 and bytesout > 4, we presume this is
389 			 * a write data operation, which is accompanied by an
390 			 * address.
391 			 */
392 			trans->type = SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS;
393 		else
394 			trans->type = SPI_OPCODE_TYPE_WRITE_NO_ADDRESS;
395 		return;
396 	}
397 
398 	if (trans->bytesout == 1) {	/* and bytesin is > 0 */
399 		trans->type = SPI_OPCODE_TYPE_READ_NO_ADDRESS;
400 		return;
401 	}
402 
403 	if (trans->bytesout == 4)	/* and bytesin is > 0 */
404 		trans->type = SPI_OPCODE_TYPE_READ_WITH_ADDRESS;
405 
406 	/* Fast read command is called with 5 bytes instead of 4 */
407 	if (trans->out[0] == SPI_OPCODE_FAST_READ && trans->bytesout == 5) {
408 		trans->type = SPI_OPCODE_TYPE_READ_WITH_ADDRESS;
409 		--trans->bytesout;
410 	}
411 }
412 
413 static int spi_setup_opcode(struct spi_trans *trans)
414 {
415 	uint16_t optypes;
416 	uint8_t opmenu[ctlr.menubytes];
417 
418 	trans->opcode = trans->out[0];
419 	spi_use_out(trans, 1);
420 	if (!ctlr.ichspi_lock) {
421 		/* The lock is off, so just use index 0. */
422 		ich_writeb(trans->opcode, ctlr.opmenu);
423 		optypes = ich_readw(ctlr.optype);
424 		optypes = (optypes & 0xfffc) | (trans->type & 0x3);
425 		ich_writew(optypes, ctlr.optype);
426 		return 0;
427 	} else {
428 		/* The lock is on. See if what we need is on the menu. */
429 		uint8_t optype;
430 		uint16_t opcode_index;
431 
432 		/* Write Enable is handled as atomic prefix */
433 		if (trans->opcode == SPI_OPCODE_WREN)
434 			return 0;
435 
436 		read_reg(ctlr.opmenu, opmenu, sizeof(opmenu));
437 		for (opcode_index = 0; opcode_index < ctlr.menubytes;
438 				opcode_index++) {
439 			if (opmenu[opcode_index] == trans->opcode)
440 				break;
441 		}
442 
443 		if (opcode_index == ctlr.menubytes) {
444 			printf("ICH SPI: Opcode %x not found\n",
445 			       trans->opcode);
446 			return -1;
447 		}
448 
449 		optypes = ich_readw(ctlr.optype);
450 		optype = (optypes >> (opcode_index * 2)) & 0x3;
451 		if (trans->type == SPI_OPCODE_TYPE_WRITE_NO_ADDRESS &&
452 		    optype == SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS &&
453 		    trans->bytesout >= 3) {
454 			/* We guessed wrong earlier. Fix it up. */
455 			trans->type = optype;
456 		}
457 		if (optype != trans->type) {
458 			printf("ICH SPI: Transaction doesn't fit type %d\n",
459 			       optype);
460 			return -1;
461 		}
462 		return opcode_index;
463 	}
464 }
465 
466 static int spi_setup_offset(struct spi_trans *trans)
467 {
468 	/* Separate the SPI address and data. */
469 	switch (trans->type) {
470 	case SPI_OPCODE_TYPE_READ_NO_ADDRESS:
471 	case SPI_OPCODE_TYPE_WRITE_NO_ADDRESS:
472 		return 0;
473 	case SPI_OPCODE_TYPE_READ_WITH_ADDRESS:
474 	case SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS:
475 		trans->offset = ((uint32_t)trans->out[0] << 16) |
476 				((uint32_t)trans->out[1] << 8) |
477 				((uint32_t)trans->out[2] << 0);
478 		spi_use_out(trans, 3);
479 		return 1;
480 	default:
481 		printf("Unrecognized SPI transaction type %#x\n", trans->type);
482 		return -1;
483 	}
484 }
485 
486 /*
487  * Wait for up to 6s til status register bit(s) turn 1 (in case wait_til_set
488  * below is true) or 0. In case the wait was for the bit(s) to set - write
489  * those bits back, which would cause resetting them.
490  *
491  * Return the last read status value on success or -1 on failure.
492  */
493 static int ich_status_poll(u16 bitmask, int wait_til_set)
494 {
495 	int timeout = 600000; /* This will result in 6s */
496 	u16 status = 0;
497 
498 	while (timeout--) {
499 		status = ich_readw(ctlr.status);
500 		if (wait_til_set ^ ((status & bitmask) == 0)) {
501 			if (wait_til_set)
502 				ich_writew((status & bitmask), ctlr.status);
503 			return status;
504 		}
505 		udelay(10);
506 	}
507 
508 	printf("ICH SPI: SCIP timeout, read %x, expected %x\n",
509 	       status, bitmask);
510 	return -1;
511 }
512 
513 /*
514 int spi_xfer(struct spi_slave *slave, const void *dout,
515 		unsigned int bitsout, void *din, unsigned int bitsin)
516 */
517 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
518 		void *din, unsigned long flags)
519 {
520 	struct ich_spi_slave *ich = to_ich_spi(slave);
521 	uint16_t control;
522 	int16_t opcode_index;
523 	int with_address;
524 	int status;
525 	int bytes = bitlen / 8;
526 	struct spi_trans *trans = &ich->trans;
527 	unsigned type = flags & (SPI_XFER_BEGIN | SPI_XFER_END);
528 	int using_cmd = 0;
529 
530 	/* Ee don't support writing partial bytes. */
531 	if (bitlen % 8) {
532 		debug("ICH SPI: Accessing partial bytes not supported\n");
533 		return -1;
534 	}
535 
536 	/* An empty end transaction can be ignored */
537 	if (type == SPI_XFER_END && !dout && !din)
538 		return 0;
539 
540 	if (type & SPI_XFER_BEGIN)
541 		memset(trans, '\0', sizeof(*trans));
542 
543 	/* Dp we need to come back later to finish it? */
544 	if (dout && type == SPI_XFER_BEGIN) {
545 		if (bytes > ICH_MAX_CMD_LEN) {
546 			debug("ICH SPI: Command length limit exceeded\n");
547 			return -1;
548 		}
549 		memcpy(trans->cmd, dout, bytes);
550 		trans->cmd_len = bytes;
551 		debug("ICH SPI: Saved %d bytes\n", bytes);
552 		return 0;
553 	}
554 
555 	/*
556 	 * We process a 'middle' spi_xfer() call, which has no
557 	 * SPI_XFER_BEGIN/END, as an independent transaction as if it had
558 	 * an end. We therefore repeat the command. This is because ICH
559 	 * seems to have no support for this, or because interest (in digging
560 	 * out the details and creating a special case in the code) is low.
561 	 */
562 	if (trans->cmd_len) {
563 		trans->out = trans->cmd;
564 		trans->bytesout = trans->cmd_len;
565 		using_cmd = 1;
566 		debug("ICH SPI: Using %d bytes\n", trans->cmd_len);
567 	} else {
568 		trans->out = dout;
569 		trans->bytesout = dout ? bytes : 0;
570 	}
571 
572 	trans->in = din;
573 	trans->bytesin = din ? bytes : 0;
574 
575 	/* There has to always at least be an opcode. */
576 	if (!trans->bytesout) {
577 		debug("ICH SPI: No opcode for transfer\n");
578 		return -1;
579 	}
580 
581 	if (ich_status_poll(SPIS_SCIP, 0) == -1)
582 		return -1;
583 
584 	ich_writew(SPIS_CDS | SPIS_FCERR, ctlr.status);
585 
586 	spi_setup_type(trans, using_cmd ? bytes : 0);
587 	opcode_index = spi_setup_opcode(trans);
588 	if (opcode_index < 0)
589 		return -1;
590 	with_address = spi_setup_offset(trans);
591 	if (with_address < 0)
592 		return -1;
593 
594 	if (trans->opcode == SPI_OPCODE_WREN) {
595 		/*
596 		 * Treat Write Enable as Atomic Pre-Op if possible
597 		 * in order to prevent the Management Engine from
598 		 * issuing a transaction between WREN and DATA.
599 		 */
600 		if (!ctlr.ichspi_lock)
601 			ich_writew(trans->opcode, ctlr.preop);
602 		return 0;
603 	}
604 
605 	if (ctlr.speed && ctlr.max_speed >= 33000000) {
606 		int byte;
607 
608 		byte = ich_readb(ctlr.speed);
609 		if (ich->speed >= 33000000)
610 			byte |= SSFC_SCF_33MHZ;
611 		else
612 			byte &= ~SSFC_SCF_33MHZ;
613 		ich_writeb(byte, ctlr.speed);
614 	}
615 
616 	/* See if we have used up the command data */
617 	if (using_cmd && dout && bytes) {
618 		trans->out = dout;
619 		trans->bytesout = bytes;
620 		debug("ICH SPI: Moving to data, %d bytes\n", bytes);
621 	}
622 
623 	/* Preset control fields */
624 	control = ich_readw(ctlr.control);
625 	control &= ~SSFC_RESERVED;
626 	control = SPIC_SCGO | ((opcode_index & 0x07) << 4);
627 
628 	/* Issue atomic preop cycle if needed */
629 	if (ich_readw(ctlr.preop))
630 		control |= SPIC_ACS;
631 
632 	if (!trans->bytesout && !trans->bytesin) {
633 		/* SPI addresses are 24 bit only */
634 		if (with_address)
635 			ich_writel(trans->offset & 0x00FFFFFF, ctlr.addr);
636 
637 		/*
638 		 * This is a 'no data' command (like Write Enable), its
639 		 * bitesout size was 1, decremented to zero while executing
640 		 * spi_setup_opcode() above. Tell the chip to send the
641 		 * command.
642 		 */
643 		ich_writew(control, ctlr.control);
644 
645 		/* wait for the result */
646 		status = ich_status_poll(SPIS_CDS | SPIS_FCERR, 1);
647 		if (status == -1)
648 			return -1;
649 
650 		if (status & SPIS_FCERR) {
651 			debug("ICH SPI: Command transaction error\n");
652 			return -1;
653 		}
654 
655 		return 0;
656 	}
657 
658 	/*
659 	 * Check if this is a write command atempting to transfer more bytes
660 	 * than the controller can handle. Iterations for writes are not
661 	 * supported here because each SPI write command needs to be preceded
662 	 * and followed by other SPI commands, and this sequence is controlled
663 	 * by the SPI chip driver.
664 	 */
665 	if (trans->bytesout > ctlr.databytes) {
666 		debug("ICH SPI: Too much to write. This should be prevented by the driver's max_write_size?\n");
667 		return -1;
668 	}
669 
670 	/*
671 	 * Read or write up to databytes bytes at a time until everything has
672 	 * been sent.
673 	 */
674 	while (trans->bytesout || trans->bytesin) {
675 		uint32_t data_length;
676 
677 		/* SPI addresses are 24 bit only */
678 		ich_writel(trans->offset & 0x00FFFFFF, ctlr.addr);
679 
680 		if (trans->bytesout)
681 			data_length = min(trans->bytesout, ctlr.databytes);
682 		else
683 			data_length = min(trans->bytesin, ctlr.databytes);
684 
685 		/* Program data into FDATA0 to N */
686 		if (trans->bytesout) {
687 			write_reg(trans->out, ctlr.data, data_length);
688 			spi_use_out(trans, data_length);
689 			if (with_address)
690 				trans->offset += data_length;
691 		}
692 
693 		/* Add proper control fields' values */
694 		control &= ~((ctlr.databytes - 1) << 8);
695 		control |= SPIC_DS;
696 		control |= (data_length - 1) << 8;
697 
698 		/* write it */
699 		ich_writew(control, ctlr.control);
700 
701 		/* Wait for Cycle Done Status or Flash Cycle Error. */
702 		status = ich_status_poll(SPIS_CDS | SPIS_FCERR, 1);
703 		if (status == -1)
704 			return -1;
705 
706 		if (status & SPIS_FCERR) {
707 			debug("ICH SPI: Data transaction error\n");
708 			return -1;
709 		}
710 
711 		if (trans->bytesin) {
712 			read_reg(ctlr.data, trans->in, data_length);
713 			spi_use_in(trans, data_length);
714 			if (with_address)
715 				trans->offset += data_length;
716 		}
717 	}
718 
719 	/* Clear atomic preop now that xfer is done */
720 	ich_writew(0, ctlr.preop);
721 
722 	return 0;
723 }
724 
725 
726 /*
727  * This uses the SPI controller from the Intel Cougar Point and Panther Point
728  * PCH to write-protect portions of the SPI flash until reboot. The changes
729  * don't actually take effect until the HSFS[FLOCKDN] bit is set, but that's
730  * done elsewhere.
731  */
732 int spi_write_protect_region(uint32_t lower_limit, uint32_t length, int hint)
733 {
734 	uint32_t tmplong;
735 	uint32_t upper_limit;
736 
737 	if (!ctlr.pr) {
738 		printf("%s: operation not supported on this chipset\n",
739 		       __func__);
740 		return -1;
741 	}
742 
743 	if (length == 0 ||
744 	    lower_limit > (0xFFFFFFFFUL - length) + 1 ||
745 	    hint < 0 || hint > 4) {
746 		printf("%s(0x%x, 0x%x, %d): invalid args\n", __func__,
747 		       lower_limit, length, hint);
748 		return -1;
749 	}
750 
751 	upper_limit = lower_limit + length - 1;
752 
753 	/*
754 	 * Determine bits to write, as follows:
755 	 *  31     Write-protection enable (includes erase operation)
756 	 *  30:29  reserved
757 	 *  28:16  Upper Limit (FLA address bits 24:12, with 11:0 == 0xfff)
758 	 *  15     Read-protection enable
759 	 *  14:13  reserved
760 	 *  12:0   Lower Limit (FLA address bits 24:12, with 11:0 == 0x000)
761 	 */
762 	tmplong = 0x80000000 |
763 		((upper_limit & 0x01fff000) << 4) |
764 		((lower_limit & 0x01fff000) >> 12);
765 
766 	printf("%s: writing 0x%08x to %p\n", __func__, tmplong,
767 	       &ctlr.pr[hint]);
768 	ctlr.pr[hint] = tmplong;
769 
770 	return 0;
771 }
772