xref: /openbmc/u-boot/drivers/spi/ich.c (revision 7e8702a00fe88590c2ece93061da4a40adf3c242)
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  #include <common.h>
9  #include <dm.h>
10  #include <errno.h>
11  #include <malloc.h>
12  #include <pch.h>
13  #include <pci.h>
14  #include <pci_ids.h>
15  #include <spi.h>
16  #include <asm/io.h>
17  
18  #include "ich.h"
19  
20  #define SPI_OPCODE_WREN      0x06
21  #define SPI_OPCODE_FAST_READ 0x0b
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  struct ich_spi_platdata {
30  	enum pch_version ich_version;	/* Controller version, 7 or 9 */
31  };
32  
33  struct ich_spi_priv {
34  	int ichspi_lock;
35  	int locked;
36  	int opmenu;
37  	int menubytes;
38  	void *base;		/* Base of register set */
39  	int preop;
40  	int optype;
41  	int addr;
42  	int data;
43  	unsigned databytes;
44  	int status;
45  	int control;
46  	int bbar;
47  	int bcr;
48  	uint32_t *pr;		/* only for ich9 */
49  	int speed;		/* pointer to speed control */
50  	ulong max_speed;	/* Maximum bus speed in MHz */
51  	ulong cur_speed;	/* Current bus speed */
52  	struct spi_trans trans;	/* current transaction in progress */
53  };
54  
55  static u8 ich_readb(struct ich_spi_priv *priv, int reg)
56  {
57  	u8 value = readb(priv->base + reg);
58  
59  	debug_trace("read %2.2x from %4.4x\n", value, reg);
60  
61  	return value;
62  }
63  
64  static u16 ich_readw(struct ich_spi_priv *priv, int reg)
65  {
66  	u16 value = readw(priv->base + reg);
67  
68  	debug_trace("read %4.4x from %4.4x\n", value, reg);
69  
70  	return value;
71  }
72  
73  static u32 ich_readl(struct ich_spi_priv *priv, int reg)
74  {
75  	u32 value = readl(priv->base + reg);
76  
77  	debug_trace("read %8.8x from %4.4x\n", value, reg);
78  
79  	return value;
80  }
81  
82  static void ich_writeb(struct ich_spi_priv *priv, u8 value, int reg)
83  {
84  	writeb(value, priv->base + reg);
85  	debug_trace("wrote %2.2x to %4.4x\n", value, reg);
86  }
87  
88  static void ich_writew(struct ich_spi_priv *priv, u16 value, int reg)
89  {
90  	writew(value, priv->base + reg);
91  	debug_trace("wrote %4.4x to %4.4x\n", value, reg);
92  }
93  
94  static void ich_writel(struct ich_spi_priv *priv, u32 value, int reg)
95  {
96  	writel(value, priv->base + reg);
97  	debug_trace("wrote %8.8x to %4.4x\n", value, reg);
98  }
99  
100  static void write_reg(struct ich_spi_priv *priv, const void *value,
101  		      int dest_reg, uint32_t size)
102  {
103  	memcpy_toio(priv->base + dest_reg, value, size);
104  }
105  
106  static void read_reg(struct ich_spi_priv *priv, int src_reg, void *value,
107  		     uint32_t size)
108  {
109  	memcpy_fromio(value, priv->base + src_reg, size);
110  }
111  
112  static void ich_set_bbar(struct ich_spi_priv *ctlr, uint32_t minaddr)
113  {
114  	const uint32_t bbar_mask = 0x00ffff00;
115  	uint32_t ichspi_bbar;
116  
117  	minaddr &= bbar_mask;
118  	ichspi_bbar = ich_readl(ctlr, ctlr->bbar) & ~bbar_mask;
119  	ichspi_bbar |= minaddr;
120  	ich_writel(ctlr, ichspi_bbar, ctlr->bbar);
121  }
122  
123  /* @return 1 if the SPI flash supports the 33MHz speed */
124  static int ich9_can_do_33mhz(struct udevice *dev)
125  {
126  	u32 fdod, speed;
127  
128  	/* Observe SPI Descriptor Component Section 0 */
129  	dm_pci_write_config32(dev->parent, 0xb0, 0x1000);
130  
131  	/* Extract the Write/Erase SPI Frequency from descriptor */
132  	dm_pci_read_config32(dev->parent, 0xb4, &fdod);
133  
134  	/* Bits 23:21 have the fast read clock frequency, 0=20MHz, 1=33MHz */
135  	speed = (fdod >> 21) & 7;
136  
137  	return speed == 1;
138  }
139  
140  static int ich_init_controller(struct udevice *dev,
141  			       struct ich_spi_platdata *plat,
142  			       struct ich_spi_priv *ctlr)
143  {
144  	ulong sbase_addr;
145  	void *sbase;
146  
147  	/* SBASE is similar */
148  	pch_get_sbase(dev->parent, &sbase_addr);
149  	sbase = (void *)sbase_addr;
150  	debug("%s: sbase=%p\n", __func__, sbase);
151  
152  	if (plat->ich_version == PCHV_7) {
153  		struct ich7_spi_regs *ich7_spi = sbase;
154  
155  		ich7_spi = (struct ich7_spi_regs *)sbase;
156  		ctlr->ichspi_lock = readw(&ich7_spi->spis) & SPIS_LOCK;
157  		ctlr->opmenu = offsetof(struct ich7_spi_regs, opmenu);
158  		ctlr->menubytes = sizeof(ich7_spi->opmenu);
159  		ctlr->optype = offsetof(struct ich7_spi_regs, optype);
160  		ctlr->addr = offsetof(struct ich7_spi_regs, spia);
161  		ctlr->data = offsetof(struct ich7_spi_regs, spid);
162  		ctlr->databytes = sizeof(ich7_spi->spid);
163  		ctlr->status = offsetof(struct ich7_spi_regs, spis);
164  		ctlr->control = offsetof(struct ich7_spi_regs, spic);
165  		ctlr->bbar = offsetof(struct ich7_spi_regs, bbar);
166  		ctlr->preop = offsetof(struct ich7_spi_regs, preop);
167  		ctlr->base = ich7_spi;
168  	} else if (plat->ich_version == PCHV_9) {
169  		struct ich9_spi_regs *ich9_spi = sbase;
170  
171  		ctlr->ichspi_lock = readw(&ich9_spi->hsfs) & HSFS_FLOCKDN;
172  		ctlr->opmenu = offsetof(struct ich9_spi_regs, opmenu);
173  		ctlr->menubytes = sizeof(ich9_spi->opmenu);
174  		ctlr->optype = offsetof(struct ich9_spi_regs, optype);
175  		ctlr->addr = offsetof(struct ich9_spi_regs, faddr);
176  		ctlr->data = offsetof(struct ich9_spi_regs, fdata);
177  		ctlr->databytes = sizeof(ich9_spi->fdata);
178  		ctlr->status = offsetof(struct ich9_spi_regs, ssfs);
179  		ctlr->control = offsetof(struct ich9_spi_regs, ssfc);
180  		ctlr->speed = ctlr->control + 2;
181  		ctlr->bbar = offsetof(struct ich9_spi_regs, bbar);
182  		ctlr->preop = offsetof(struct ich9_spi_regs, preop);
183  		ctlr->bcr = offsetof(struct ich9_spi_regs, bcr);
184  		ctlr->pr = &ich9_spi->pr[0];
185  		ctlr->base = ich9_spi;
186  	} else {
187  		debug("ICH SPI: Unrecognised ICH version %d\n",
188  		      plat->ich_version);
189  		return -EINVAL;
190  	}
191  
192  	/* Work out the maximum speed we can support */
193  	ctlr->max_speed = 20000000;
194  	if (plat->ich_version == PCHV_9 && ich9_can_do_33mhz(dev))
195  		ctlr->max_speed = 33000000;
196  	debug("ICH SPI: Version ID %d detected at %p, speed %ld\n",
197  	      plat->ich_version, ctlr->base, ctlr->max_speed);
198  
199  	ich_set_bbar(ctlr, 0);
200  
201  	return 0;
202  }
203  
204  static inline void spi_use_out(struct spi_trans *trans, unsigned bytes)
205  {
206  	trans->out += bytes;
207  	trans->bytesout -= bytes;
208  }
209  
210  static inline void spi_use_in(struct spi_trans *trans, unsigned bytes)
211  {
212  	trans->in += bytes;
213  	trans->bytesin -= bytes;
214  }
215  
216  static void spi_setup_type(struct spi_trans *trans, int data_bytes)
217  {
218  	trans->type = 0xFF;
219  
220  	/* Try to guess spi type from read/write sizes. */
221  	if (trans->bytesin == 0) {
222  		if (trans->bytesout + data_bytes > 4)
223  			/*
224  			 * If bytesin = 0 and bytesout > 4, we presume this is
225  			 * a write data operation, which is accompanied by an
226  			 * address.
227  			 */
228  			trans->type = SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS;
229  		else
230  			trans->type = SPI_OPCODE_TYPE_WRITE_NO_ADDRESS;
231  		return;
232  	}
233  
234  	if (trans->bytesout == 1) {	/* and bytesin is > 0 */
235  		trans->type = SPI_OPCODE_TYPE_READ_NO_ADDRESS;
236  		return;
237  	}
238  
239  	if (trans->bytesout == 4)	/* and bytesin is > 0 */
240  		trans->type = SPI_OPCODE_TYPE_READ_WITH_ADDRESS;
241  
242  	/* Fast read command is called with 5 bytes instead of 4 */
243  	if (trans->out[0] == SPI_OPCODE_FAST_READ && trans->bytesout == 5) {
244  		trans->type = SPI_OPCODE_TYPE_READ_WITH_ADDRESS;
245  		--trans->bytesout;
246  	}
247  }
248  
249  static int spi_setup_opcode(struct ich_spi_priv *ctlr, struct spi_trans *trans)
250  {
251  	uint16_t optypes;
252  	uint8_t opmenu[ctlr->menubytes];
253  
254  	trans->opcode = trans->out[0];
255  	spi_use_out(trans, 1);
256  	if (!ctlr->ichspi_lock) {
257  		/* The lock is off, so just use index 0. */
258  		ich_writeb(ctlr, trans->opcode, ctlr->opmenu);
259  		optypes = ich_readw(ctlr, ctlr->optype);
260  		optypes = (optypes & 0xfffc) | (trans->type & 0x3);
261  		ich_writew(ctlr, optypes, ctlr->optype);
262  		return 0;
263  	} else {
264  		/* The lock is on. See if what we need is on the menu. */
265  		uint8_t optype;
266  		uint16_t opcode_index;
267  
268  		/* Write Enable is handled as atomic prefix */
269  		if (trans->opcode == SPI_OPCODE_WREN)
270  			return 0;
271  
272  		read_reg(ctlr, ctlr->opmenu, opmenu, sizeof(opmenu));
273  		for (opcode_index = 0; opcode_index < ctlr->menubytes;
274  				opcode_index++) {
275  			if (opmenu[opcode_index] == trans->opcode)
276  				break;
277  		}
278  
279  		if (opcode_index == ctlr->menubytes) {
280  			printf("ICH SPI: Opcode %x not found\n",
281  			       trans->opcode);
282  			return -EINVAL;
283  		}
284  
285  		optypes = ich_readw(ctlr, ctlr->optype);
286  		optype = (optypes >> (opcode_index * 2)) & 0x3;
287  		if (trans->type == SPI_OPCODE_TYPE_WRITE_NO_ADDRESS &&
288  		    optype == SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS &&
289  		    trans->bytesout >= 3) {
290  			/* We guessed wrong earlier. Fix it up. */
291  			trans->type = optype;
292  		}
293  		if (optype != trans->type) {
294  			printf("ICH SPI: Transaction doesn't fit type %d\n",
295  			       optype);
296  			return -ENOSPC;
297  		}
298  		return opcode_index;
299  	}
300  }
301  
302  static int spi_setup_offset(struct spi_trans *trans)
303  {
304  	/* Separate the SPI address and data. */
305  	switch (trans->type) {
306  	case SPI_OPCODE_TYPE_READ_NO_ADDRESS:
307  	case SPI_OPCODE_TYPE_WRITE_NO_ADDRESS:
308  		return 0;
309  	case SPI_OPCODE_TYPE_READ_WITH_ADDRESS:
310  	case SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS:
311  		trans->offset = ((uint32_t)trans->out[0] << 16) |
312  				((uint32_t)trans->out[1] << 8) |
313  				((uint32_t)trans->out[2] << 0);
314  		spi_use_out(trans, 3);
315  		return 1;
316  	default:
317  		printf("Unrecognized SPI transaction type %#x\n", trans->type);
318  		return -EPROTO;
319  	}
320  }
321  
322  /*
323   * Wait for up to 6s til status register bit(s) turn 1 (in case wait_til_set
324   * below is true) or 0. In case the wait was for the bit(s) to set - write
325   * those bits back, which would cause resetting them.
326   *
327   * Return the last read status value on success or -1 on failure.
328   */
329  static int ich_status_poll(struct ich_spi_priv *ctlr, u16 bitmask,
330  			   int wait_til_set)
331  {
332  	int timeout = 600000; /* This will result in 6s */
333  	u16 status = 0;
334  
335  	while (timeout--) {
336  		status = ich_readw(ctlr, ctlr->status);
337  		if (wait_til_set ^ ((status & bitmask) == 0)) {
338  			if (wait_til_set) {
339  				ich_writew(ctlr, status & bitmask,
340  					   ctlr->status);
341  			}
342  			return status;
343  		}
344  		udelay(10);
345  	}
346  
347  	printf("ICH SPI: SCIP timeout, read %x, expected %x\n",
348  	       status, bitmask);
349  	return -ETIMEDOUT;
350  }
351  
352  static int ich_spi_xfer(struct udevice *dev, unsigned int bitlen,
353  			const void *dout, void *din, unsigned long flags)
354  {
355  	struct udevice *bus = dev_get_parent(dev);
356  	struct ich_spi_platdata *plat = dev_get_platdata(bus);
357  	struct ich_spi_priv *ctlr = dev_get_priv(bus);
358  	uint16_t control;
359  	int16_t opcode_index;
360  	int with_address;
361  	int status;
362  	int bytes = bitlen / 8;
363  	struct spi_trans *trans = &ctlr->trans;
364  	unsigned type = flags & (SPI_XFER_BEGIN | SPI_XFER_END);
365  	int using_cmd = 0;
366  	int ret;
367  
368  	/* We don't support writing partial bytes */
369  	if (bitlen % 8) {
370  		debug("ICH SPI: Accessing partial bytes not supported\n");
371  		return -EPROTONOSUPPORT;
372  	}
373  
374  	/* An empty end transaction can be ignored */
375  	if (type == SPI_XFER_END && !dout && !din)
376  		return 0;
377  
378  	if (type & SPI_XFER_BEGIN)
379  		memset(trans, '\0', sizeof(*trans));
380  
381  	/* Dp we need to come back later to finish it? */
382  	if (dout && type == SPI_XFER_BEGIN) {
383  		if (bytes > ICH_MAX_CMD_LEN) {
384  			debug("ICH SPI: Command length limit exceeded\n");
385  			return -ENOSPC;
386  		}
387  		memcpy(trans->cmd, dout, bytes);
388  		trans->cmd_len = bytes;
389  		debug_trace("ICH SPI: Saved %d bytes\n", bytes);
390  		return 0;
391  	}
392  
393  	/*
394  	 * We process a 'middle' spi_xfer() call, which has no
395  	 * SPI_XFER_BEGIN/END, as an independent transaction as if it had
396  	 * an end. We therefore repeat the command. This is because ICH
397  	 * seems to have no support for this, or because interest (in digging
398  	 * out the details and creating a special case in the code) is low.
399  	 */
400  	if (trans->cmd_len) {
401  		trans->out = trans->cmd;
402  		trans->bytesout = trans->cmd_len;
403  		using_cmd = 1;
404  		debug_trace("ICH SPI: Using %d bytes\n", trans->cmd_len);
405  	} else {
406  		trans->out = dout;
407  		trans->bytesout = dout ? bytes : 0;
408  	}
409  
410  	trans->in = din;
411  	trans->bytesin = din ? bytes : 0;
412  
413  	/* There has to always at least be an opcode. */
414  	if (!trans->bytesout) {
415  		debug("ICH SPI: No opcode for transfer\n");
416  		return -EPROTO;
417  	}
418  
419  	ret = ich_status_poll(ctlr, SPIS_SCIP, 0);
420  	if (ret < 0)
421  		return ret;
422  
423  	if (plat->ich_version == PCHV_7)
424  		ich_writew(ctlr, SPIS_CDS | SPIS_FCERR, ctlr->status);
425  	else
426  		ich_writeb(ctlr, SPIS_CDS | SPIS_FCERR, ctlr->status);
427  
428  	spi_setup_type(trans, using_cmd ? bytes : 0);
429  	opcode_index = spi_setup_opcode(ctlr, trans);
430  	if (opcode_index < 0)
431  		return -EINVAL;
432  	with_address = spi_setup_offset(trans);
433  	if (with_address < 0)
434  		return -EINVAL;
435  
436  	if (trans->opcode == SPI_OPCODE_WREN) {
437  		/*
438  		 * Treat Write Enable as Atomic Pre-Op if possible
439  		 * in order to prevent the Management Engine from
440  		 * issuing a transaction between WREN and DATA.
441  		 */
442  		if (!ctlr->ichspi_lock)
443  			ich_writew(ctlr, trans->opcode, ctlr->preop);
444  		return 0;
445  	}
446  
447  	if (ctlr->speed && ctlr->max_speed >= 33000000) {
448  		int byte;
449  
450  		byte = ich_readb(ctlr, ctlr->speed);
451  		if (ctlr->cur_speed >= 33000000)
452  			byte |= SSFC_SCF_33MHZ;
453  		else
454  			byte &= ~SSFC_SCF_33MHZ;
455  		ich_writeb(ctlr, byte, ctlr->speed);
456  	}
457  
458  	/* See if we have used up the command data */
459  	if (using_cmd && dout && bytes) {
460  		trans->out = dout;
461  		trans->bytesout = bytes;
462  		debug_trace("ICH SPI: Moving to data, %d bytes\n", bytes);
463  	}
464  
465  	/* Preset control fields */
466  	control = ich_readw(ctlr, ctlr->control);
467  	control &= ~SSFC_RESERVED;
468  	control = SPIC_SCGO | ((opcode_index & 0x07) << 4);
469  
470  	/* Issue atomic preop cycle if needed */
471  	if (ich_readw(ctlr, ctlr->preop))
472  		control |= SPIC_ACS;
473  
474  	if (!trans->bytesout && !trans->bytesin) {
475  		/* SPI addresses are 24 bit only */
476  		if (with_address) {
477  			ich_writel(ctlr, trans->offset & 0x00FFFFFF,
478  				   ctlr->addr);
479  		}
480  		/*
481  		 * This is a 'no data' command (like Write Enable), its
482  		 * bitesout size was 1, decremented to zero while executing
483  		 * spi_setup_opcode() above. Tell the chip to send the
484  		 * command.
485  		 */
486  		ich_writew(ctlr, control, ctlr->control);
487  
488  		/* wait for the result */
489  		status = ich_status_poll(ctlr, SPIS_CDS | SPIS_FCERR, 1);
490  		if (status < 0)
491  			return status;
492  
493  		if (status & SPIS_FCERR) {
494  			debug("ICH SPI: Command transaction error\n");
495  			return -EIO;
496  		}
497  
498  		return 0;
499  	}
500  
501  	/*
502  	 * Check if this is a write command atempting to transfer more bytes
503  	 * than the controller can handle. Iterations for writes are not
504  	 * supported here because each SPI write command needs to be preceded
505  	 * and followed by other SPI commands, and this sequence is controlled
506  	 * by the SPI chip driver.
507  	 */
508  	if (trans->bytesout > ctlr->databytes) {
509  		debug("ICH SPI: Too much to write. This should be prevented by the driver's max_write_size?\n");
510  		return -EPROTO;
511  	}
512  
513  	/*
514  	 * Read or write up to databytes bytes at a time until everything has
515  	 * been sent.
516  	 */
517  	while (trans->bytesout || trans->bytesin) {
518  		uint32_t data_length;
519  
520  		/* SPI addresses are 24 bit only */
521  		ich_writel(ctlr, trans->offset & 0x00FFFFFF, ctlr->addr);
522  
523  		if (trans->bytesout)
524  			data_length = min(trans->bytesout, ctlr->databytes);
525  		else
526  			data_length = min(trans->bytesin, ctlr->databytes);
527  
528  		/* Program data into FDATA0 to N */
529  		if (trans->bytesout) {
530  			write_reg(ctlr, trans->out, ctlr->data, data_length);
531  			spi_use_out(trans, data_length);
532  			if (with_address)
533  				trans->offset += data_length;
534  		}
535  
536  		/* Add proper control fields' values */
537  		control &= ~((ctlr->databytes - 1) << 8);
538  		control |= SPIC_DS;
539  		control |= (data_length - 1) << 8;
540  
541  		/* write it */
542  		ich_writew(ctlr, control, ctlr->control);
543  
544  		/* Wait for Cycle Done Status or Flash Cycle Error. */
545  		status = ich_status_poll(ctlr, SPIS_CDS | SPIS_FCERR, 1);
546  		if (status < 0)
547  			return status;
548  
549  		if (status & SPIS_FCERR) {
550  			debug("ICH SPI: Data transaction error %x\n", status);
551  			return -EIO;
552  		}
553  
554  		if (trans->bytesin) {
555  			read_reg(ctlr, ctlr->data, trans->in, data_length);
556  			spi_use_in(trans, data_length);
557  			if (with_address)
558  				trans->offset += data_length;
559  		}
560  	}
561  
562  	/* Clear atomic preop now that xfer is done */
563  	ich_writew(ctlr, 0, ctlr->preop);
564  
565  	return 0;
566  }
567  
568  /*
569   * This uses the SPI controller from the Intel Cougar Point and Panther Point
570   * PCH to write-protect portions of the SPI flash until reboot. The changes
571   * don't actually take effect until the HSFS[FLOCKDN] bit is set, but that's
572   * done elsewhere.
573   */
574  int spi_write_protect_region(struct udevice *dev, uint32_t lower_limit,
575  			     uint32_t length, int hint)
576  {
577  	struct udevice *bus = dev->parent;
578  	struct ich_spi_priv *ctlr = dev_get_priv(bus);
579  	uint32_t tmplong;
580  	uint32_t upper_limit;
581  
582  	if (!ctlr->pr) {
583  		printf("%s: operation not supported on this chipset\n",
584  		       __func__);
585  		return -ENOSYS;
586  	}
587  
588  	if (length == 0 ||
589  	    lower_limit > (0xFFFFFFFFUL - length) + 1 ||
590  	    hint < 0 || hint > 4) {
591  		printf("%s(0x%x, 0x%x, %d): invalid args\n", __func__,
592  		       lower_limit, length, hint);
593  		return -EPERM;
594  	}
595  
596  	upper_limit = lower_limit + length - 1;
597  
598  	/*
599  	 * Determine bits to write, as follows:
600  	 *  31     Write-protection enable (includes erase operation)
601  	 *  30:29  reserved
602  	 *  28:16  Upper Limit (FLA address bits 24:12, with 11:0 == 0xfff)
603  	 *  15     Read-protection enable
604  	 *  14:13  reserved
605  	 *  12:0   Lower Limit (FLA address bits 24:12, with 11:0 == 0x000)
606  	 */
607  	tmplong = 0x80000000 |
608  		((upper_limit & 0x01fff000) << 4) |
609  		((lower_limit & 0x01fff000) >> 12);
610  
611  	printf("%s: writing 0x%08x to %p\n", __func__, tmplong,
612  	       &ctlr->pr[hint]);
613  	ctlr->pr[hint] = tmplong;
614  
615  	return 0;
616  }
617  
618  static int ich_spi_probe(struct udevice *dev)
619  {
620  	struct ich_spi_platdata *plat = dev_get_platdata(dev);
621  	struct ich_spi_priv *priv = dev_get_priv(dev);
622  	uint8_t bios_cntl;
623  	int ret;
624  
625  	/* Check the ICH version */
626  	plat->ich_version = pch_get_version(dev->parent);
627  
628  	ret = ich_init_controller(dev, plat, priv);
629  	if (ret)
630  		return ret;
631  	/* Disable the BIOS write protect so write commands are allowed */
632  	ret = pch_set_spi_protect(dev->parent, false);
633  	if (ret == -ENOSYS) {
634  		bios_cntl = ich_readb(priv, priv->bcr);
635  		bios_cntl &= ~BIT(5);	/* clear Enable InSMM_STS (EISS) */
636  		bios_cntl |= 1;		/* Write Protect Disable (WPD) */
637  		ich_writeb(priv, bios_cntl, priv->bcr);
638  	} else if (ret) {
639  		debug("%s: Failed to disable write-protect: err=%d\n",
640  		      __func__, ret);
641  		return ret;
642  	}
643  
644  	priv->cur_speed = priv->max_speed;
645  
646  	return 0;
647  }
648  
649  static int ich_spi_set_speed(struct udevice *bus, uint speed)
650  {
651  	struct ich_spi_priv *priv = dev_get_priv(bus);
652  
653  	priv->cur_speed = speed;
654  
655  	return 0;
656  }
657  
658  static int ich_spi_set_mode(struct udevice *bus, uint mode)
659  {
660  	debug("%s: mode=%d\n", __func__, mode);
661  
662  	return 0;
663  }
664  
665  static int ich_spi_child_pre_probe(struct udevice *dev)
666  {
667  	struct udevice *bus = dev_get_parent(dev);
668  	struct ich_spi_platdata *plat = dev_get_platdata(bus);
669  	struct ich_spi_priv *priv = dev_get_priv(bus);
670  	struct spi_slave *slave = dev_get_parent_priv(dev);
671  
672  	/*
673  	 * Yes this controller can only write a small number of bytes at
674  	 * once! The limit is typically 64 bytes.
675  	 */
676  	slave->max_write_size = priv->databytes;
677  	/*
678  	 * ICH 7 SPI controller only supports array read command
679  	 * and byte program command for SST flash
680  	 */
681  	if (plat->ich_version == PCHV_7) {
682  		slave->mode_rx = SPI_RX_SLOW;
683  		slave->mode = SPI_TX_BYTE;
684  	}
685  
686  	return 0;
687  }
688  
689  static const struct dm_spi_ops ich_spi_ops = {
690  	.xfer		= ich_spi_xfer,
691  	.set_speed	= ich_spi_set_speed,
692  	.set_mode	= ich_spi_set_mode,
693  	/*
694  	 * cs_info is not needed, since we require all chip selects to be
695  	 * in the device tree explicitly
696  	 */
697  };
698  
699  static const struct udevice_id ich_spi_ids[] = {
700  	{ .compatible = "intel,ich-spi" },
701  	{ }
702  };
703  
704  U_BOOT_DRIVER(ich_spi) = {
705  	.name	= "ich_spi",
706  	.id	= UCLASS_SPI,
707  	.of_match = ich_spi_ids,
708  	.ops	= &ich_spi_ops,
709  	.platdata_auto_alloc_size = sizeof(struct ich_spi_platdata),
710  	.priv_auto_alloc_size = sizeof(struct ich_spi_priv),
711  	.child_pre_probe = ich_spi_child_pre_probe,
712  	.probe	= ich_spi_probe,
713  };
714