1 /*******************************************************************************
2 
3   Intel(R) Gigabit Ethernet Linux driver
4   Copyright(c) 2007-2012 Intel Corporation.
5 
6   This program is free software; you can redistribute it and/or modify it
7   under the terms and conditions of the GNU General Public License,
8   version 2, as published by the Free Software Foundation.
9 
10   This program is distributed in the hope it will be useful, but WITHOUT
11   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13   more details.
14 
15   You should have received a copy of the GNU General Public License along with
16   this program; if not, write to the Free Software Foundation, Inc.,
17   51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
18 
19   The full GNU General Public License is included in this distribution in
20   the file called "COPYING".
21 
22   Contact Information:
23   e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
24   Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
25 
26 *******************************************************************************/
27 
28 #include <linux/if_ether.h>
29 #include <linux/delay.h>
30 
31 #include "e1000_mac.h"
32 #include "e1000_nvm.h"
33 
34 /**
35  *  igb_raise_eec_clk - Raise EEPROM clock
36  *  @hw: pointer to the HW structure
37  *  @eecd: pointer to the EEPROM
38  *
39  *  Enable/Raise the EEPROM clock bit.
40  **/
41 static void igb_raise_eec_clk(struct e1000_hw *hw, u32 *eecd)
42 {
43 	*eecd = *eecd | E1000_EECD_SK;
44 	wr32(E1000_EECD, *eecd);
45 	wrfl();
46 	udelay(hw->nvm.delay_usec);
47 }
48 
49 /**
50  *  igb_lower_eec_clk - Lower EEPROM clock
51  *  @hw: pointer to the HW structure
52  *  @eecd: pointer to the EEPROM
53  *
54  *  Clear/Lower the EEPROM clock bit.
55  **/
56 static void igb_lower_eec_clk(struct e1000_hw *hw, u32 *eecd)
57 {
58 	*eecd = *eecd & ~E1000_EECD_SK;
59 	wr32(E1000_EECD, *eecd);
60 	wrfl();
61 	udelay(hw->nvm.delay_usec);
62 }
63 
64 /**
65  *  igb_shift_out_eec_bits - Shift data bits our to the EEPROM
66  *  @hw: pointer to the HW structure
67  *  @data: data to send to the EEPROM
68  *  @count: number of bits to shift out
69  *
70  *  We need to shift 'count' bits out to the EEPROM.  So, the value in the
71  *  "data" parameter will be shifted out to the EEPROM one bit at a time.
72  *  In order to do this, "data" must be broken down into bits.
73  **/
74 static void igb_shift_out_eec_bits(struct e1000_hw *hw, u16 data, u16 count)
75 {
76 	struct e1000_nvm_info *nvm = &hw->nvm;
77 	u32 eecd = rd32(E1000_EECD);
78 	u32 mask;
79 
80 	mask = 0x01 << (count - 1);
81 	if (nvm->type == e1000_nvm_eeprom_spi)
82 		eecd |= E1000_EECD_DO;
83 
84 	do {
85 		eecd &= ~E1000_EECD_DI;
86 
87 		if (data & mask)
88 			eecd |= E1000_EECD_DI;
89 
90 		wr32(E1000_EECD, eecd);
91 		wrfl();
92 
93 		udelay(nvm->delay_usec);
94 
95 		igb_raise_eec_clk(hw, &eecd);
96 		igb_lower_eec_clk(hw, &eecd);
97 
98 		mask >>= 1;
99 	} while (mask);
100 
101 	eecd &= ~E1000_EECD_DI;
102 	wr32(E1000_EECD, eecd);
103 }
104 
105 /**
106  *  igb_shift_in_eec_bits - Shift data bits in from the EEPROM
107  *  @hw: pointer to the HW structure
108  *  @count: number of bits to shift in
109  *
110  *  In order to read a register from the EEPROM, we need to shift 'count' bits
111  *  in from the EEPROM.  Bits are "shifted in" by raising the clock input to
112  *  the EEPROM (setting the SK bit), and then reading the value of the data out
113  *  "DO" bit.  During this "shifting in" process the data in "DI" bit should
114  *  always be clear.
115  **/
116 static u16 igb_shift_in_eec_bits(struct e1000_hw *hw, u16 count)
117 {
118 	u32 eecd;
119 	u32 i;
120 	u16 data;
121 
122 	eecd = rd32(E1000_EECD);
123 
124 	eecd &= ~(E1000_EECD_DO | E1000_EECD_DI);
125 	data = 0;
126 
127 	for (i = 0; i < count; i++) {
128 		data <<= 1;
129 		igb_raise_eec_clk(hw, &eecd);
130 
131 		eecd = rd32(E1000_EECD);
132 
133 		eecd &= ~E1000_EECD_DI;
134 		if (eecd & E1000_EECD_DO)
135 			data |= 1;
136 
137 		igb_lower_eec_clk(hw, &eecd);
138 	}
139 
140 	return data;
141 }
142 
143 /**
144  *  igb_poll_eerd_eewr_done - Poll for EEPROM read/write completion
145  *  @hw: pointer to the HW structure
146  *  @ee_reg: EEPROM flag for polling
147  *
148  *  Polls the EEPROM status bit for either read or write completion based
149  *  upon the value of 'ee_reg'.
150  **/
151 static s32 igb_poll_eerd_eewr_done(struct e1000_hw *hw, int ee_reg)
152 {
153 	u32 attempts = 100000;
154 	u32 i, reg = 0;
155 	s32 ret_val = -E1000_ERR_NVM;
156 
157 	for (i = 0; i < attempts; i++) {
158 		if (ee_reg == E1000_NVM_POLL_READ)
159 			reg = rd32(E1000_EERD);
160 		else
161 			reg = rd32(E1000_EEWR);
162 
163 		if (reg & E1000_NVM_RW_REG_DONE) {
164 			ret_val = 0;
165 			break;
166 		}
167 
168 		udelay(5);
169 	}
170 
171 	return ret_val;
172 }
173 
174 /**
175  *  igb_acquire_nvm - Generic request for access to EEPROM
176  *  @hw: pointer to the HW structure
177  *
178  *  Set the EEPROM access request bit and wait for EEPROM access grant bit.
179  *  Return successful if access grant bit set, else clear the request for
180  *  EEPROM access and return -E1000_ERR_NVM (-1).
181  **/
182 s32 igb_acquire_nvm(struct e1000_hw *hw)
183 {
184 	u32 eecd = rd32(E1000_EECD);
185 	s32 timeout = E1000_NVM_GRANT_ATTEMPTS;
186 	s32 ret_val = 0;
187 
188 
189 	wr32(E1000_EECD, eecd | E1000_EECD_REQ);
190 	eecd = rd32(E1000_EECD);
191 
192 	while (timeout) {
193 		if (eecd & E1000_EECD_GNT)
194 			break;
195 		udelay(5);
196 		eecd = rd32(E1000_EECD);
197 		timeout--;
198 	}
199 
200 	if (!timeout) {
201 		eecd &= ~E1000_EECD_REQ;
202 		wr32(E1000_EECD, eecd);
203 		hw_dbg("Could not acquire NVM grant\n");
204 		ret_val = -E1000_ERR_NVM;
205 	}
206 
207 	return ret_val;
208 }
209 
210 /**
211  *  igb_standby_nvm - Return EEPROM to standby state
212  *  @hw: pointer to the HW structure
213  *
214  *  Return the EEPROM to a standby state.
215  **/
216 static void igb_standby_nvm(struct e1000_hw *hw)
217 {
218 	struct e1000_nvm_info *nvm = &hw->nvm;
219 	u32 eecd = rd32(E1000_EECD);
220 
221 	if (nvm->type == e1000_nvm_eeprom_spi) {
222 		/* Toggle CS to flush commands */
223 		eecd |= E1000_EECD_CS;
224 		wr32(E1000_EECD, eecd);
225 		wrfl();
226 		udelay(nvm->delay_usec);
227 		eecd &= ~E1000_EECD_CS;
228 		wr32(E1000_EECD, eecd);
229 		wrfl();
230 		udelay(nvm->delay_usec);
231 	}
232 }
233 
234 /**
235  *  e1000_stop_nvm - Terminate EEPROM command
236  *  @hw: pointer to the HW structure
237  *
238  *  Terminates the current command by inverting the EEPROM's chip select pin.
239  **/
240 static void e1000_stop_nvm(struct e1000_hw *hw)
241 {
242 	u32 eecd;
243 
244 	eecd = rd32(E1000_EECD);
245 	if (hw->nvm.type == e1000_nvm_eeprom_spi) {
246 		/* Pull CS high */
247 		eecd |= E1000_EECD_CS;
248 		igb_lower_eec_clk(hw, &eecd);
249 	}
250 }
251 
252 /**
253  *  igb_release_nvm - Release exclusive access to EEPROM
254  *  @hw: pointer to the HW structure
255  *
256  *  Stop any current commands to the EEPROM and clear the EEPROM request bit.
257  **/
258 void igb_release_nvm(struct e1000_hw *hw)
259 {
260 	u32 eecd;
261 
262 	e1000_stop_nvm(hw);
263 
264 	eecd = rd32(E1000_EECD);
265 	eecd &= ~E1000_EECD_REQ;
266 	wr32(E1000_EECD, eecd);
267 }
268 
269 /**
270  *  igb_ready_nvm_eeprom - Prepares EEPROM for read/write
271  *  @hw: pointer to the HW structure
272  *
273  *  Setups the EEPROM for reading and writing.
274  **/
275 static s32 igb_ready_nvm_eeprom(struct e1000_hw *hw)
276 {
277 	struct e1000_nvm_info *nvm = &hw->nvm;
278 	u32 eecd = rd32(E1000_EECD);
279 	s32 ret_val = 0;
280 	u16 timeout = 0;
281 	u8 spi_stat_reg;
282 
283 
284 	if (nvm->type == e1000_nvm_eeprom_spi) {
285 		/* Clear SK and CS */
286 		eecd &= ~(E1000_EECD_CS | E1000_EECD_SK);
287 		wr32(E1000_EECD, eecd);
288 		wrfl();
289 		udelay(1);
290 		timeout = NVM_MAX_RETRY_SPI;
291 
292 		/*
293 		 * Read "Status Register" repeatedly until the LSB is cleared.
294 		 * The EEPROM will signal that the command has been completed
295 		 * by clearing bit 0 of the internal status register.  If it's
296 		 * not cleared within 'timeout', then error out.
297 		 */
298 		while (timeout) {
299 			igb_shift_out_eec_bits(hw, NVM_RDSR_OPCODE_SPI,
300 						 hw->nvm.opcode_bits);
301 			spi_stat_reg = (u8)igb_shift_in_eec_bits(hw, 8);
302 			if (!(spi_stat_reg & NVM_STATUS_RDY_SPI))
303 				break;
304 
305 			udelay(5);
306 			igb_standby_nvm(hw);
307 			timeout--;
308 		}
309 
310 		if (!timeout) {
311 			hw_dbg("SPI NVM Status error\n");
312 			ret_val = -E1000_ERR_NVM;
313 			goto out;
314 		}
315 	}
316 
317 out:
318 	return ret_val;
319 }
320 
321 /**
322  *  igb_read_nvm_spi - Read EEPROM's using SPI
323  *  @hw: pointer to the HW structure
324  *  @offset: offset of word in the EEPROM to read
325  *  @words: number of words to read
326  *  @data: word read from the EEPROM
327  *
328  *  Reads a 16 bit word from the EEPROM.
329  **/
330 s32 igb_read_nvm_spi(struct e1000_hw *hw, u16 offset, u16 words, u16 *data)
331 {
332 	struct e1000_nvm_info *nvm = &hw->nvm;
333 	u32 i = 0;
334 	s32 ret_val;
335 	u16 word_in;
336 	u8 read_opcode = NVM_READ_OPCODE_SPI;
337 
338 	/*
339 	 * A check for invalid values:  offset too large, too many words,
340 	 * and not enough words.
341 	 */
342 	if ((offset >= nvm->word_size) || (words > (nvm->word_size - offset)) ||
343 	    (words == 0)) {
344 		hw_dbg("nvm parameter(s) out of bounds\n");
345 		ret_val = -E1000_ERR_NVM;
346 		goto out;
347 	}
348 
349 	ret_val = nvm->ops.acquire(hw);
350 	if (ret_val)
351 		goto out;
352 
353 	ret_val = igb_ready_nvm_eeprom(hw);
354 	if (ret_val)
355 		goto release;
356 
357 	igb_standby_nvm(hw);
358 
359 	if ((nvm->address_bits == 8) && (offset >= 128))
360 		read_opcode |= NVM_A8_OPCODE_SPI;
361 
362 	/* Send the READ command (opcode + addr) */
363 	igb_shift_out_eec_bits(hw, read_opcode, nvm->opcode_bits);
364 	igb_shift_out_eec_bits(hw, (u16)(offset*2), nvm->address_bits);
365 
366 	/*
367 	 * Read the data.  SPI NVMs increment the address with each byte
368 	 * read and will roll over if reading beyond the end.  This allows
369 	 * us to read the whole NVM from any offset
370 	 */
371 	for (i = 0; i < words; i++) {
372 		word_in = igb_shift_in_eec_bits(hw, 16);
373 		data[i] = (word_in >> 8) | (word_in << 8);
374 	}
375 
376 release:
377 	nvm->ops.release(hw);
378 
379 out:
380 	return ret_val;
381 }
382 
383 /**
384  *  igb_read_nvm_eerd - Reads EEPROM using EERD register
385  *  @hw: pointer to the HW structure
386  *  @offset: offset of word in the EEPROM to read
387  *  @words: number of words to read
388  *  @data: word read from the EEPROM
389  *
390  *  Reads a 16 bit word from the EEPROM using the EERD register.
391  **/
392 s32 igb_read_nvm_eerd(struct e1000_hw *hw, u16 offset, u16 words, u16 *data)
393 {
394 	struct e1000_nvm_info *nvm = &hw->nvm;
395 	u32 i, eerd = 0;
396 	s32 ret_val = 0;
397 
398 	/*
399 	 * A check for invalid values:  offset too large, too many words,
400 	 * and not enough words.
401 	 */
402 	if ((offset >= nvm->word_size) || (words > (nvm->word_size - offset)) ||
403 	    (words == 0)) {
404 		hw_dbg("nvm parameter(s) out of bounds\n");
405 		ret_val = -E1000_ERR_NVM;
406 		goto out;
407 	}
408 
409 	for (i = 0; i < words; i++) {
410 		eerd = ((offset+i) << E1000_NVM_RW_ADDR_SHIFT) +
411 		       E1000_NVM_RW_REG_START;
412 
413 		wr32(E1000_EERD, eerd);
414 		ret_val = igb_poll_eerd_eewr_done(hw, E1000_NVM_POLL_READ);
415 		if (ret_val)
416 			break;
417 
418 		data[i] = (rd32(E1000_EERD) >>
419 			E1000_NVM_RW_REG_DATA);
420 	}
421 
422 out:
423 	return ret_val;
424 }
425 
426 /**
427  *  igb_write_nvm_spi - Write to EEPROM using SPI
428  *  @hw: pointer to the HW structure
429  *  @offset: offset within the EEPROM to be written to
430  *  @words: number of words to write
431  *  @data: 16 bit word(s) to be written to the EEPROM
432  *
433  *  Writes data to EEPROM at offset using SPI interface.
434  *
435  *  If e1000_update_nvm_checksum is not called after this function , the
436  *  EEPROM will most likley contain an invalid checksum.
437  **/
438 s32 igb_write_nvm_spi(struct e1000_hw *hw, u16 offset, u16 words, u16 *data)
439 {
440 	struct e1000_nvm_info *nvm = &hw->nvm;
441 	s32 ret_val = -E1000_ERR_NVM;
442 	u16 widx = 0;
443 
444 	/*
445 	 * A check for invalid values:  offset too large, too many words,
446 	 * and not enough words.
447 	 */
448 	if ((offset >= nvm->word_size) || (words > (nvm->word_size - offset)) ||
449 	    (words == 0)) {
450 		hw_dbg("nvm parameter(s) out of bounds\n");
451 		return ret_val;
452 	}
453 
454 	while (widx < words) {
455 		u8 write_opcode = NVM_WRITE_OPCODE_SPI;
456 
457 		ret_val = nvm->ops.acquire(hw);
458 		if (ret_val)
459 			return ret_val;
460 
461 		ret_val = igb_ready_nvm_eeprom(hw);
462 		if (ret_val) {
463 			nvm->ops.release(hw);
464 			return ret_val;
465 		}
466 
467 		igb_standby_nvm(hw);
468 
469 		/* Send the WRITE ENABLE command (8 bit opcode) */
470 		igb_shift_out_eec_bits(hw, NVM_WREN_OPCODE_SPI,
471 					 nvm->opcode_bits);
472 
473 		igb_standby_nvm(hw);
474 
475 		/*
476 		 * Some SPI eeproms use the 8th address bit embedded in the
477 		 * opcode
478 		 */
479 		if ((nvm->address_bits == 8) && (offset >= 128))
480 			write_opcode |= NVM_A8_OPCODE_SPI;
481 
482 		/* Send the Write command (8-bit opcode + addr) */
483 		igb_shift_out_eec_bits(hw, write_opcode, nvm->opcode_bits);
484 		igb_shift_out_eec_bits(hw, (u16)((offset + widx) * 2),
485 					 nvm->address_bits);
486 
487 		/* Loop to allow for up to whole page write of eeprom */
488 		while (widx < words) {
489 			u16 word_out = data[widx];
490 			word_out = (word_out >> 8) | (word_out << 8);
491 			igb_shift_out_eec_bits(hw, word_out, 16);
492 			widx++;
493 
494 			if ((((offset + widx) * 2) % nvm->page_size) == 0) {
495 				igb_standby_nvm(hw);
496 				break;
497 			}
498 		}
499 		usleep_range(1000, 2000);
500 		nvm->ops.release(hw);
501 	}
502 
503 	return ret_val;
504 }
505 
506 /**
507  *  igb_read_part_string - Read device part number
508  *  @hw: pointer to the HW structure
509  *  @part_num: pointer to device part number
510  *  @part_num_size: size of part number buffer
511  *
512  *  Reads the product board assembly (PBA) number from the EEPROM and stores
513  *  the value in part_num.
514  **/
515 s32 igb_read_part_string(struct e1000_hw *hw, u8 *part_num, u32 part_num_size)
516 {
517 	s32 ret_val;
518 	u16 nvm_data;
519 	u16 pointer;
520 	u16 offset;
521 	u16 length;
522 
523 	if (part_num == NULL) {
524 		hw_dbg("PBA string buffer was null\n");
525 		ret_val = E1000_ERR_INVALID_ARGUMENT;
526 		goto out;
527 	}
528 
529 	ret_val = hw->nvm.ops.read(hw, NVM_PBA_OFFSET_0, 1, &nvm_data);
530 	if (ret_val) {
531 		hw_dbg("NVM Read Error\n");
532 		goto out;
533 	}
534 
535 	ret_val = hw->nvm.ops.read(hw, NVM_PBA_OFFSET_1, 1, &pointer);
536 	if (ret_val) {
537 		hw_dbg("NVM Read Error\n");
538 		goto out;
539 	}
540 
541 	/*
542 	 * if nvm_data is not ptr guard the PBA must be in legacy format which
543 	 * means pointer is actually our second data word for the PBA number
544 	 * and we can decode it into an ascii string
545 	 */
546 	if (nvm_data != NVM_PBA_PTR_GUARD) {
547 		hw_dbg("NVM PBA number is not stored as string\n");
548 
549 		/* we will need 11 characters to store the PBA */
550 		if (part_num_size < 11) {
551 			hw_dbg("PBA string buffer too small\n");
552 			return E1000_ERR_NO_SPACE;
553 		}
554 
555 		/* extract hex string from data and pointer */
556 		part_num[0] = (nvm_data >> 12) & 0xF;
557 		part_num[1] = (nvm_data >> 8) & 0xF;
558 		part_num[2] = (nvm_data >> 4) & 0xF;
559 		part_num[3] = nvm_data & 0xF;
560 		part_num[4] = (pointer >> 12) & 0xF;
561 		part_num[5] = (pointer >> 8) & 0xF;
562 		part_num[6] = '-';
563 		part_num[7] = 0;
564 		part_num[8] = (pointer >> 4) & 0xF;
565 		part_num[9] = pointer & 0xF;
566 
567 		/* put a null character on the end of our string */
568 		part_num[10] = '\0';
569 
570 		/* switch all the data but the '-' to hex char */
571 		for (offset = 0; offset < 10; offset++) {
572 			if (part_num[offset] < 0xA)
573 				part_num[offset] += '0';
574 			else if (part_num[offset] < 0x10)
575 				part_num[offset] += 'A' - 0xA;
576 		}
577 
578 		goto out;
579 	}
580 
581 	ret_val = hw->nvm.ops.read(hw, pointer, 1, &length);
582 	if (ret_val) {
583 		hw_dbg("NVM Read Error\n");
584 		goto out;
585 	}
586 
587 	if (length == 0xFFFF || length == 0) {
588 		hw_dbg("NVM PBA number section invalid length\n");
589 		ret_val = E1000_ERR_NVM_PBA_SECTION;
590 		goto out;
591 	}
592 	/* check if part_num buffer is big enough */
593 	if (part_num_size < (((u32)length * 2) - 1)) {
594 		hw_dbg("PBA string buffer too small\n");
595 		ret_val = E1000_ERR_NO_SPACE;
596 		goto out;
597 	}
598 
599 	/* trim pba length from start of string */
600 	pointer++;
601 	length--;
602 
603 	for (offset = 0; offset < length; offset++) {
604 		ret_val = hw->nvm.ops.read(hw, pointer + offset, 1, &nvm_data);
605 		if (ret_val) {
606 			hw_dbg("NVM Read Error\n");
607 			goto out;
608 		}
609 		part_num[offset * 2] = (u8)(nvm_data >> 8);
610 		part_num[(offset * 2) + 1] = (u8)(nvm_data & 0xFF);
611 	}
612 	part_num[offset * 2] = '\0';
613 
614 out:
615 	return ret_val;
616 }
617 
618 /**
619  *  igb_read_mac_addr - Read device MAC address
620  *  @hw: pointer to the HW structure
621  *
622  *  Reads the device MAC address from the EEPROM and stores the value.
623  *  Since devices with two ports use the same EEPROM, we increment the
624  *  last bit in the MAC address for the second port.
625  **/
626 s32 igb_read_mac_addr(struct e1000_hw *hw)
627 {
628 	u32 rar_high;
629 	u32 rar_low;
630 	u16 i;
631 
632 	rar_high = rd32(E1000_RAH(0));
633 	rar_low = rd32(E1000_RAL(0));
634 
635 	for (i = 0; i < E1000_RAL_MAC_ADDR_LEN; i++)
636 		hw->mac.perm_addr[i] = (u8)(rar_low >> (i*8));
637 
638 	for (i = 0; i < E1000_RAH_MAC_ADDR_LEN; i++)
639 		hw->mac.perm_addr[i+4] = (u8)(rar_high >> (i*8));
640 
641 	for (i = 0; i < ETH_ALEN; i++)
642 		hw->mac.addr[i] = hw->mac.perm_addr[i];
643 
644 	return 0;
645 }
646 
647 /**
648  *  igb_validate_nvm_checksum - Validate EEPROM checksum
649  *  @hw: pointer to the HW structure
650  *
651  *  Calculates the EEPROM checksum by reading/adding each word of the EEPROM
652  *  and then verifies that the sum of the EEPROM is equal to 0xBABA.
653  **/
654 s32 igb_validate_nvm_checksum(struct e1000_hw *hw)
655 {
656 	s32 ret_val = 0;
657 	u16 checksum = 0;
658 	u16 i, nvm_data;
659 
660 	for (i = 0; i < (NVM_CHECKSUM_REG + 1); i++) {
661 		ret_val = hw->nvm.ops.read(hw, i, 1, &nvm_data);
662 		if (ret_val) {
663 			hw_dbg("NVM Read Error\n");
664 			goto out;
665 		}
666 		checksum += nvm_data;
667 	}
668 
669 	if (checksum != (u16) NVM_SUM) {
670 		hw_dbg("NVM Checksum Invalid\n");
671 		ret_val = -E1000_ERR_NVM;
672 		goto out;
673 	}
674 
675 out:
676 	return ret_val;
677 }
678 
679 /**
680  *  igb_update_nvm_checksum - Update EEPROM checksum
681  *  @hw: pointer to the HW structure
682  *
683  *  Updates the EEPROM checksum by reading/adding each word of the EEPROM
684  *  up to the checksum.  Then calculates the EEPROM checksum and writes the
685  *  value to the EEPROM.
686  **/
687 s32 igb_update_nvm_checksum(struct e1000_hw *hw)
688 {
689 	s32  ret_val;
690 	u16 checksum = 0;
691 	u16 i, nvm_data;
692 
693 	for (i = 0; i < NVM_CHECKSUM_REG; i++) {
694 		ret_val = hw->nvm.ops.read(hw, i, 1, &nvm_data);
695 		if (ret_val) {
696 			hw_dbg("NVM Read Error while updating checksum.\n");
697 			goto out;
698 		}
699 		checksum += nvm_data;
700 	}
701 	checksum = (u16) NVM_SUM - checksum;
702 	ret_val = hw->nvm.ops.write(hw, NVM_CHECKSUM_REG, 1, &checksum);
703 	if (ret_val)
704 		hw_dbg("NVM Write Error while updating checksum.\n");
705 
706 out:
707 	return ret_val;
708 }
709 
710 /**
711  *  igb_get_fw_version - Get firmware version information
712  *  @hw: pointer to the HW structure
713  *  @fw_vers: pointer to output structure
714  *
715  *  unsupported MAC types will return all 0 version structure
716  **/
717 void igb_get_fw_version(struct e1000_hw *hw, struct e1000_fw_version *fw_vers)
718 {
719 	u16 eeprom_verh, eeprom_verl, comb_verh, comb_verl, comb_offset;
720 	u16 fw_version;
721 
722 	memset(fw_vers, 0, sizeof(struct e1000_fw_version));
723 
724 	switch (hw->mac.type) {
725 	case e1000_i211:
726 		igb_read_invm_version(hw, fw_vers);
727 		return;
728 	case e1000_82575:
729 	case e1000_82576:
730 	case e1000_82580:
731 	case e1000_i350:
732 	case e1000_i210:
733 		break;
734 	default:
735 		return;
736 	}
737 	/* basic eeprom version numbers */
738 	hw->nvm.ops.read(hw, NVM_VERSION, 1, &fw_version);
739 	fw_vers->eep_major = (fw_version & NVM_MAJOR_MASK) >> NVM_MAJOR_SHIFT;
740 	fw_vers->eep_minor = (fw_version & NVM_MINOR_MASK);
741 
742 	/* etrack id */
743 	hw->nvm.ops.read(hw, NVM_ETRACK_WORD, 1, &eeprom_verl);
744 	hw->nvm.ops.read(hw, (NVM_ETRACK_WORD + 1), 1, &eeprom_verh);
745 	fw_vers->etrack_id = (eeprom_verh << NVM_ETRACK_SHIFT) | eeprom_verl;
746 
747 	switch (hw->mac.type) {
748 	case e1000_i210:
749 	case e1000_i350:
750 		/* find combo image version */
751 		hw->nvm.ops.read(hw, NVM_COMB_VER_PTR, 1, &comb_offset);
752 		if ((comb_offset != 0x0) && (comb_offset != NVM_VER_INVALID)) {
753 
754 			hw->nvm.ops.read(hw, (NVM_COMB_VER_OFF + comb_offset
755 					 + 1), 1, &comb_verh);
756 			hw->nvm.ops.read(hw, (NVM_COMB_VER_OFF + comb_offset),
757 					 1, &comb_verl);
758 
759 			/* get Option Rom version if it exists and is valid */
760 			if ((comb_verh && comb_verl) &&
761 			    ((comb_verh != NVM_VER_INVALID) &&
762 			     (comb_verl != NVM_VER_INVALID))) {
763 
764 				fw_vers->or_valid = true;
765 				fw_vers->or_major =
766 					comb_verl >> NVM_COMB_VER_SHFT;
767 				fw_vers->or_build =
768 					((comb_verl << NVM_COMB_VER_SHFT)
769 					| (comb_verh >> NVM_COMB_VER_SHFT));
770 				fw_vers->or_patch =
771 					comb_verh & NVM_COMB_VER_MASK;
772 			}
773 		}
774 		break;
775 	default:
776 		break;
777 	}
778 	return;
779 }
780