1 /*******************************************************************************
2 
3   Intel(R) Gigabit Ethernet Linux driver
4   Copyright(c) 2007-2014 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, see <http://www.gnu.org/licenses/>.
17 
18   The full GNU General Public License is included in this distribution in
19   the file called "COPYING".
20 
21   Contact Information:
22   e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
23   Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
24 
25 *******************************************************************************/
26 
27 #include <linux/if_ether.h>
28 #include <linux/delay.h>
29 
30 #include "e1000_mac.h"
31 #include "e1000_nvm.h"
32 
33 /**
34  *  igb_raise_eec_clk - Raise EEPROM clock
35  *  @hw: pointer to the HW structure
36  *  @eecd: pointer to the EEPROM
37  *
38  *  Enable/Raise the EEPROM clock bit.
39  **/
40 static void igb_raise_eec_clk(struct e1000_hw *hw, u32 *eecd)
41 {
42 	*eecd = *eecd | E1000_EECD_SK;
43 	wr32(E1000_EECD, *eecd);
44 	wrfl();
45 	udelay(hw->nvm.delay_usec);
46 }
47 
48 /**
49  *  igb_lower_eec_clk - Lower EEPROM clock
50  *  @hw: pointer to the HW structure
51  *  @eecd: pointer to the EEPROM
52  *
53  *  Clear/Lower the EEPROM clock bit.
54  **/
55 static void igb_lower_eec_clk(struct e1000_hw *hw, u32 *eecd)
56 {
57 	*eecd = *eecd & ~E1000_EECD_SK;
58 	wr32(E1000_EECD, *eecd);
59 	wrfl();
60 	udelay(hw->nvm.delay_usec);
61 }
62 
63 /**
64  *  igb_shift_out_eec_bits - Shift data bits our to the EEPROM
65  *  @hw: pointer to the HW structure
66  *  @data: data to send to the EEPROM
67  *  @count: number of bits to shift out
68  *
69  *  We need to shift 'count' bits out to the EEPROM.  So, the value in the
70  *  "data" parameter will be shifted out to the EEPROM one bit at a time.
71  *  In order to do this, "data" must be broken down into bits.
72  **/
73 static void igb_shift_out_eec_bits(struct e1000_hw *hw, u16 data, u16 count)
74 {
75 	struct e1000_nvm_info *nvm = &hw->nvm;
76 	u32 eecd = rd32(E1000_EECD);
77 	u32 mask;
78 
79 	mask = 0x01 << (count - 1);
80 	if (nvm->type == e1000_nvm_eeprom_spi)
81 		eecd |= E1000_EECD_DO;
82 
83 	do {
84 		eecd &= ~E1000_EECD_DI;
85 
86 		if (data & mask)
87 			eecd |= E1000_EECD_DI;
88 
89 		wr32(E1000_EECD, eecd);
90 		wrfl();
91 
92 		udelay(nvm->delay_usec);
93 
94 		igb_raise_eec_clk(hw, &eecd);
95 		igb_lower_eec_clk(hw, &eecd);
96 
97 		mask >>= 1;
98 	} while (mask);
99 
100 	eecd &= ~E1000_EECD_DI;
101 	wr32(E1000_EECD, eecd);
102 }
103 
104 /**
105  *  igb_shift_in_eec_bits - Shift data bits in from the EEPROM
106  *  @hw: pointer to the HW structure
107  *  @count: number of bits to shift in
108  *
109  *  In order to read a register from the EEPROM, we need to shift 'count' bits
110  *  in from the EEPROM.  Bits are "shifted in" by raising the clock input to
111  *  the EEPROM (setting the SK bit), and then reading the value of the data out
112  *  "DO" bit.  During this "shifting in" process the data in "DI" bit should
113  *  always be clear.
114  **/
115 static u16 igb_shift_in_eec_bits(struct e1000_hw *hw, u16 count)
116 {
117 	u32 eecd;
118 	u32 i;
119 	u16 data;
120 
121 	eecd = rd32(E1000_EECD);
122 
123 	eecd &= ~(E1000_EECD_DO | E1000_EECD_DI);
124 	data = 0;
125 
126 	for (i = 0; i < count; i++) {
127 		data <<= 1;
128 		igb_raise_eec_clk(hw, &eecd);
129 
130 		eecd = rd32(E1000_EECD);
131 
132 		eecd &= ~E1000_EECD_DI;
133 		if (eecd & E1000_EECD_DO)
134 			data |= 1;
135 
136 		igb_lower_eec_clk(hw, &eecd);
137 	}
138 
139 	return data;
140 }
141 
142 /**
143  *  igb_poll_eerd_eewr_done - Poll for EEPROM read/write completion
144  *  @hw: pointer to the HW structure
145  *  @ee_reg: EEPROM flag for polling
146  *
147  *  Polls the EEPROM status bit for either read or write completion based
148  *  upon the value of 'ee_reg'.
149  **/
150 static s32 igb_poll_eerd_eewr_done(struct e1000_hw *hw, int ee_reg)
151 {
152 	u32 attempts = 100000;
153 	u32 i, reg = 0;
154 	s32 ret_val = -E1000_ERR_NVM;
155 
156 	for (i = 0; i < attempts; i++) {
157 		if (ee_reg == E1000_NVM_POLL_READ)
158 			reg = rd32(E1000_EERD);
159 		else
160 			reg = rd32(E1000_EEWR);
161 
162 		if (reg & E1000_NVM_RW_REG_DONE) {
163 			ret_val = 0;
164 			break;
165 		}
166 
167 		udelay(5);
168 	}
169 
170 	return ret_val;
171 }
172 
173 /**
174  *  igb_acquire_nvm - Generic request for access to EEPROM
175  *  @hw: pointer to the HW structure
176  *
177  *  Set the EEPROM access request bit and wait for EEPROM access grant bit.
178  *  Return successful if access grant bit set, else clear the request for
179  *  EEPROM access and return -E1000_ERR_NVM (-1).
180  **/
181 s32 igb_acquire_nvm(struct e1000_hw *hw)
182 {
183 	u32 eecd = rd32(E1000_EECD);
184 	s32 timeout = E1000_NVM_GRANT_ATTEMPTS;
185 	s32 ret_val = 0;
186 
187 
188 	wr32(E1000_EECD, eecd | E1000_EECD_REQ);
189 	eecd = rd32(E1000_EECD);
190 
191 	while (timeout) {
192 		if (eecd & E1000_EECD_GNT)
193 			break;
194 		udelay(5);
195 		eecd = rd32(E1000_EECD);
196 		timeout--;
197 	}
198 
199 	if (!timeout) {
200 		eecd &= ~E1000_EECD_REQ;
201 		wr32(E1000_EECD, eecd);
202 		hw_dbg("Could not acquire NVM grant\n");
203 		ret_val = -E1000_ERR_NVM;
204 	}
205 
206 	return ret_val;
207 }
208 
209 /**
210  *  igb_standby_nvm - Return EEPROM to standby state
211  *  @hw: pointer to the HW structure
212  *
213  *  Return the EEPROM to a standby state.
214  **/
215 static void igb_standby_nvm(struct e1000_hw *hw)
216 {
217 	struct e1000_nvm_info *nvm = &hw->nvm;
218 	u32 eecd = rd32(E1000_EECD);
219 
220 	if (nvm->type == e1000_nvm_eeprom_spi) {
221 		/* Toggle CS to flush commands */
222 		eecd |= E1000_EECD_CS;
223 		wr32(E1000_EECD, eecd);
224 		wrfl();
225 		udelay(nvm->delay_usec);
226 		eecd &= ~E1000_EECD_CS;
227 		wr32(E1000_EECD, eecd);
228 		wrfl();
229 		udelay(nvm->delay_usec);
230 	}
231 }
232 
233 /**
234  *  e1000_stop_nvm - Terminate EEPROM command
235  *  @hw: pointer to the HW structure
236  *
237  *  Terminates the current command by inverting the EEPROM's chip select pin.
238  **/
239 static void e1000_stop_nvm(struct e1000_hw *hw)
240 {
241 	u32 eecd;
242 
243 	eecd = rd32(E1000_EECD);
244 	if (hw->nvm.type == e1000_nvm_eeprom_spi) {
245 		/* Pull CS high */
246 		eecd |= E1000_EECD_CS;
247 		igb_lower_eec_clk(hw, &eecd);
248 	}
249 }
250 
251 /**
252  *  igb_release_nvm - Release exclusive access to EEPROM
253  *  @hw: pointer to the HW structure
254  *
255  *  Stop any current commands to the EEPROM and clear the EEPROM request bit.
256  **/
257 void igb_release_nvm(struct e1000_hw *hw)
258 {
259 	u32 eecd;
260 
261 	e1000_stop_nvm(hw);
262 
263 	eecd = rd32(E1000_EECD);
264 	eecd &= ~E1000_EECD_REQ;
265 	wr32(E1000_EECD, eecd);
266 }
267 
268 /**
269  *  igb_ready_nvm_eeprom - Prepares EEPROM for read/write
270  *  @hw: pointer to the HW structure
271  *
272  *  Setups the EEPROM for reading and writing.
273  **/
274 static s32 igb_ready_nvm_eeprom(struct e1000_hw *hw)
275 {
276 	struct e1000_nvm_info *nvm = &hw->nvm;
277 	u32 eecd = rd32(E1000_EECD);
278 	s32 ret_val = 0;
279 	u16 timeout = 0;
280 	u8 spi_stat_reg;
281 
282 
283 	if (nvm->type == e1000_nvm_eeprom_spi) {
284 		/* Clear SK and CS */
285 		eecd &= ~(E1000_EECD_CS | E1000_EECD_SK);
286 		wr32(E1000_EECD, eecd);
287 		wrfl();
288 		udelay(1);
289 		timeout = NVM_MAX_RETRY_SPI;
290 
291 		/* Read "Status Register" repeatedly until the LSB is cleared.
292 		 * The EEPROM will signal that the command has been completed
293 		 * by clearing bit 0 of the internal status register.  If it's
294 		 * not cleared within 'timeout', then error out.
295 		 */
296 		while (timeout) {
297 			igb_shift_out_eec_bits(hw, NVM_RDSR_OPCODE_SPI,
298 					       hw->nvm.opcode_bits);
299 			spi_stat_reg = (u8)igb_shift_in_eec_bits(hw, 8);
300 			if (!(spi_stat_reg & NVM_STATUS_RDY_SPI))
301 				break;
302 
303 			udelay(5);
304 			igb_standby_nvm(hw);
305 			timeout--;
306 		}
307 
308 		if (!timeout) {
309 			hw_dbg("SPI NVM Status error\n");
310 			ret_val = -E1000_ERR_NVM;
311 			goto out;
312 		}
313 	}
314 
315 out:
316 	return ret_val;
317 }
318 
319 /**
320  *  igb_read_nvm_spi - Read EEPROM's using SPI
321  *  @hw: pointer to the HW structure
322  *  @offset: offset of word in the EEPROM to read
323  *  @words: number of words to read
324  *  @data: word read from the EEPROM
325  *
326  *  Reads a 16 bit word from the EEPROM.
327  **/
328 s32 igb_read_nvm_spi(struct e1000_hw *hw, u16 offset, u16 words, u16 *data)
329 {
330 	struct e1000_nvm_info *nvm = &hw->nvm;
331 	u32 i = 0;
332 	s32 ret_val;
333 	u16 word_in;
334 	u8 read_opcode = NVM_READ_OPCODE_SPI;
335 
336 	/* A check for invalid values:  offset too large, too many words,
337 	 * and not enough words.
338 	 */
339 	if ((offset >= nvm->word_size) || (words > (nvm->word_size - offset)) ||
340 	    (words == 0)) {
341 		hw_dbg("nvm parameter(s) out of bounds\n");
342 		ret_val = -E1000_ERR_NVM;
343 		goto out;
344 	}
345 
346 	ret_val = nvm->ops.acquire(hw);
347 	if (ret_val)
348 		goto out;
349 
350 	ret_val = igb_ready_nvm_eeprom(hw);
351 	if (ret_val)
352 		goto release;
353 
354 	igb_standby_nvm(hw);
355 
356 	if ((nvm->address_bits == 8) && (offset >= 128))
357 		read_opcode |= NVM_A8_OPCODE_SPI;
358 
359 	/* Send the READ command (opcode + addr) */
360 	igb_shift_out_eec_bits(hw, read_opcode, nvm->opcode_bits);
361 	igb_shift_out_eec_bits(hw, (u16)(offset*2), nvm->address_bits);
362 
363 	/* Read the data.  SPI NVMs increment the address with each byte
364 	 * read and will roll over if reading beyond the end.  This allows
365 	 * us to read the whole NVM from any offset
366 	 */
367 	for (i = 0; i < words; i++) {
368 		word_in = igb_shift_in_eec_bits(hw, 16);
369 		data[i] = (word_in >> 8) | (word_in << 8);
370 	}
371 
372 release:
373 	nvm->ops.release(hw);
374 
375 out:
376 	return ret_val;
377 }
378 
379 /**
380  *  igb_read_nvm_eerd - Reads EEPROM using EERD register
381  *  @hw: pointer to the HW structure
382  *  @offset: offset of word in the EEPROM to read
383  *  @words: number of words to read
384  *  @data: word read from the EEPROM
385  *
386  *  Reads a 16 bit word from the EEPROM using the EERD register.
387  **/
388 s32 igb_read_nvm_eerd(struct e1000_hw *hw, u16 offset, u16 words, u16 *data)
389 {
390 	struct e1000_nvm_info *nvm = &hw->nvm;
391 	u32 i, eerd = 0;
392 	s32 ret_val = 0;
393 
394 	/* A check for invalid values:  offset too large, too many words,
395 	 * and not enough words.
396 	 */
397 	if ((offset >= nvm->word_size) || (words > (nvm->word_size - offset)) ||
398 	    (words == 0)) {
399 		hw_dbg("nvm parameter(s) out of bounds\n");
400 		ret_val = -E1000_ERR_NVM;
401 		goto out;
402 	}
403 
404 	for (i = 0; i < words; i++) {
405 		eerd = ((offset+i) << E1000_NVM_RW_ADDR_SHIFT) +
406 			E1000_NVM_RW_REG_START;
407 
408 		wr32(E1000_EERD, eerd);
409 		ret_val = igb_poll_eerd_eewr_done(hw, E1000_NVM_POLL_READ);
410 		if (ret_val)
411 			break;
412 
413 		data[i] = (rd32(E1000_EERD) >>
414 			E1000_NVM_RW_REG_DATA);
415 	}
416 
417 out:
418 	return ret_val;
419 }
420 
421 /**
422  *  igb_write_nvm_spi - Write to EEPROM using SPI
423  *  @hw: pointer to the HW structure
424  *  @offset: offset within the EEPROM to be written to
425  *  @words: number of words to write
426  *  @data: 16 bit word(s) to be written to the EEPROM
427  *
428  *  Writes data to EEPROM at offset using SPI interface.
429  *
430  *  If e1000_update_nvm_checksum is not called after this function , the
431  *  EEPROM will most likley contain an invalid checksum.
432  **/
433 s32 igb_write_nvm_spi(struct e1000_hw *hw, u16 offset, u16 words, u16 *data)
434 {
435 	struct e1000_nvm_info *nvm = &hw->nvm;
436 	s32 ret_val = -E1000_ERR_NVM;
437 	u16 widx = 0;
438 
439 	/* A check for invalid values:  offset too large, too many words,
440 	 * and not enough words.
441 	 */
442 	if ((offset >= nvm->word_size) || (words > (nvm->word_size - offset)) ||
443 	    (words == 0)) {
444 		hw_dbg("nvm parameter(s) out of bounds\n");
445 		return ret_val;
446 	}
447 
448 	while (widx < words) {
449 		u8 write_opcode = NVM_WRITE_OPCODE_SPI;
450 
451 		ret_val = nvm->ops.acquire(hw);
452 		if (ret_val)
453 			return ret_val;
454 
455 		ret_val = igb_ready_nvm_eeprom(hw);
456 		if (ret_val) {
457 			nvm->ops.release(hw);
458 			return ret_val;
459 		}
460 
461 		igb_standby_nvm(hw);
462 
463 		/* Send the WRITE ENABLE command (8 bit opcode) */
464 		igb_shift_out_eec_bits(hw, NVM_WREN_OPCODE_SPI,
465 					 nvm->opcode_bits);
466 
467 		igb_standby_nvm(hw);
468 
469 		/* Some SPI eeproms use the 8th address bit embedded in the
470 		 * opcode
471 		 */
472 		if ((nvm->address_bits == 8) && (offset >= 128))
473 			write_opcode |= NVM_A8_OPCODE_SPI;
474 
475 		/* Send the Write command (8-bit opcode + addr) */
476 		igb_shift_out_eec_bits(hw, write_opcode, nvm->opcode_bits);
477 		igb_shift_out_eec_bits(hw, (u16)((offset + widx) * 2),
478 					 nvm->address_bits);
479 
480 		/* Loop to allow for up to whole page write of eeprom */
481 		while (widx < words) {
482 			u16 word_out = data[widx];
483 			word_out = (word_out >> 8) | (word_out << 8);
484 			igb_shift_out_eec_bits(hw, word_out, 16);
485 			widx++;
486 
487 			if ((((offset + widx) * 2) % nvm->page_size) == 0) {
488 				igb_standby_nvm(hw);
489 				break;
490 			}
491 		}
492 		usleep_range(1000, 2000);
493 		nvm->ops.release(hw);
494 	}
495 
496 	return ret_val;
497 }
498 
499 /**
500  *  igb_read_part_string - Read device part number
501  *  @hw: pointer to the HW structure
502  *  @part_num: pointer to device part number
503  *  @part_num_size: size of part number buffer
504  *
505  *  Reads the product board assembly (PBA) number from the EEPROM and stores
506  *  the value in part_num.
507  **/
508 s32 igb_read_part_string(struct e1000_hw *hw, u8 *part_num, u32 part_num_size)
509 {
510 	s32 ret_val;
511 	u16 nvm_data;
512 	u16 pointer;
513 	u16 offset;
514 	u16 length;
515 
516 	if (part_num == NULL) {
517 		hw_dbg("PBA string buffer was null\n");
518 		ret_val = E1000_ERR_INVALID_ARGUMENT;
519 		goto out;
520 	}
521 
522 	ret_val = hw->nvm.ops.read(hw, NVM_PBA_OFFSET_0, 1, &nvm_data);
523 	if (ret_val) {
524 		hw_dbg("NVM Read Error\n");
525 		goto out;
526 	}
527 
528 	ret_val = hw->nvm.ops.read(hw, NVM_PBA_OFFSET_1, 1, &pointer);
529 	if (ret_val) {
530 		hw_dbg("NVM Read Error\n");
531 		goto out;
532 	}
533 
534 	/* if nvm_data is not ptr guard the PBA must be in legacy format which
535 	 * means pointer is actually our second data word for the PBA number
536 	 * and we can decode it into an ascii string
537 	 */
538 	if (nvm_data != NVM_PBA_PTR_GUARD) {
539 		hw_dbg("NVM PBA number is not stored as string\n");
540 
541 		/* we will need 11 characters to store the PBA */
542 		if (part_num_size < 11) {
543 			hw_dbg("PBA string buffer too small\n");
544 			return E1000_ERR_NO_SPACE;
545 		}
546 
547 		/* extract hex string from data and pointer */
548 		part_num[0] = (nvm_data >> 12) & 0xF;
549 		part_num[1] = (nvm_data >> 8) & 0xF;
550 		part_num[2] = (nvm_data >> 4) & 0xF;
551 		part_num[3] = nvm_data & 0xF;
552 		part_num[4] = (pointer >> 12) & 0xF;
553 		part_num[5] = (pointer >> 8) & 0xF;
554 		part_num[6] = '-';
555 		part_num[7] = 0;
556 		part_num[8] = (pointer >> 4) & 0xF;
557 		part_num[9] = pointer & 0xF;
558 
559 		/* put a null character on the end of our string */
560 		part_num[10] = '\0';
561 
562 		/* switch all the data but the '-' to hex char */
563 		for (offset = 0; offset < 10; offset++) {
564 			if (part_num[offset] < 0xA)
565 				part_num[offset] += '0';
566 			else if (part_num[offset] < 0x10)
567 				part_num[offset] += 'A' - 0xA;
568 		}
569 
570 		goto out;
571 	}
572 
573 	ret_val = hw->nvm.ops.read(hw, pointer, 1, &length);
574 	if (ret_val) {
575 		hw_dbg("NVM Read Error\n");
576 		goto out;
577 	}
578 
579 	if (length == 0xFFFF || length == 0) {
580 		hw_dbg("NVM PBA number section invalid length\n");
581 		ret_val = E1000_ERR_NVM_PBA_SECTION;
582 		goto out;
583 	}
584 	/* check if part_num buffer is big enough */
585 	if (part_num_size < (((u32)length * 2) - 1)) {
586 		hw_dbg("PBA string buffer too small\n");
587 		ret_val = E1000_ERR_NO_SPACE;
588 		goto out;
589 	}
590 
591 	/* trim pba length from start of string */
592 	pointer++;
593 	length--;
594 
595 	for (offset = 0; offset < length; offset++) {
596 		ret_val = hw->nvm.ops.read(hw, pointer + offset, 1, &nvm_data);
597 		if (ret_val) {
598 			hw_dbg("NVM Read Error\n");
599 			goto out;
600 		}
601 		part_num[offset * 2] = (u8)(nvm_data >> 8);
602 		part_num[(offset * 2) + 1] = (u8)(nvm_data & 0xFF);
603 	}
604 	part_num[offset * 2] = '\0';
605 
606 out:
607 	return ret_val;
608 }
609 
610 /**
611  *  igb_read_mac_addr - Read device MAC address
612  *  @hw: pointer to the HW structure
613  *
614  *  Reads the device MAC address from the EEPROM and stores the value.
615  *  Since devices with two ports use the same EEPROM, we increment the
616  *  last bit in the MAC address for the second port.
617  **/
618 s32 igb_read_mac_addr(struct e1000_hw *hw)
619 {
620 	u32 rar_high;
621 	u32 rar_low;
622 	u16 i;
623 
624 	rar_high = rd32(E1000_RAH(0));
625 	rar_low = rd32(E1000_RAL(0));
626 
627 	for (i = 0; i < E1000_RAL_MAC_ADDR_LEN; i++)
628 		hw->mac.perm_addr[i] = (u8)(rar_low >> (i*8));
629 
630 	for (i = 0; i < E1000_RAH_MAC_ADDR_LEN; i++)
631 		hw->mac.perm_addr[i+4] = (u8)(rar_high >> (i*8));
632 
633 	for (i = 0; i < ETH_ALEN; i++)
634 		hw->mac.addr[i] = hw->mac.perm_addr[i];
635 
636 	return 0;
637 }
638 
639 /**
640  *  igb_validate_nvm_checksum - Validate EEPROM checksum
641  *  @hw: pointer to the HW structure
642  *
643  *  Calculates the EEPROM checksum by reading/adding each word of the EEPROM
644  *  and then verifies that the sum of the EEPROM is equal to 0xBABA.
645  **/
646 s32 igb_validate_nvm_checksum(struct e1000_hw *hw)
647 {
648 	s32 ret_val = 0;
649 	u16 checksum = 0;
650 	u16 i, nvm_data;
651 
652 	for (i = 0; i < (NVM_CHECKSUM_REG + 1); i++) {
653 		ret_val = hw->nvm.ops.read(hw, i, 1, &nvm_data);
654 		if (ret_val) {
655 			hw_dbg("NVM Read Error\n");
656 			goto out;
657 		}
658 		checksum += nvm_data;
659 	}
660 
661 	if (checksum != (u16) NVM_SUM) {
662 		hw_dbg("NVM Checksum Invalid\n");
663 		ret_val = -E1000_ERR_NVM;
664 		goto out;
665 	}
666 
667 out:
668 	return ret_val;
669 }
670 
671 /**
672  *  igb_update_nvm_checksum - Update EEPROM checksum
673  *  @hw: pointer to the HW structure
674  *
675  *  Updates the EEPROM checksum by reading/adding each word of the EEPROM
676  *  up to the checksum.  Then calculates the EEPROM checksum and writes the
677  *  value to the EEPROM.
678  **/
679 s32 igb_update_nvm_checksum(struct e1000_hw *hw)
680 {
681 	s32  ret_val;
682 	u16 checksum = 0;
683 	u16 i, nvm_data;
684 
685 	for (i = 0; i < NVM_CHECKSUM_REG; i++) {
686 		ret_val = hw->nvm.ops.read(hw, i, 1, &nvm_data);
687 		if (ret_val) {
688 			hw_dbg("NVM Read Error while updating checksum.\n");
689 			goto out;
690 		}
691 		checksum += nvm_data;
692 	}
693 	checksum = (u16) NVM_SUM - checksum;
694 	ret_val = hw->nvm.ops.write(hw, NVM_CHECKSUM_REG, 1, &checksum);
695 	if (ret_val)
696 		hw_dbg("NVM Write Error while updating checksum.\n");
697 
698 out:
699 	return ret_val;
700 }
701 
702 /**
703  *  igb_get_fw_version - Get firmware version information
704  *  @hw: pointer to the HW structure
705  *  @fw_vers: pointer to output structure
706  *
707  *  unsupported MAC types will return all 0 version structure
708  **/
709 void igb_get_fw_version(struct e1000_hw *hw, struct e1000_fw_version *fw_vers)
710 {
711 	u16 eeprom_verh, eeprom_verl, etrack_test, fw_version;
712 	u8 q, hval, rem, result;
713 	u16 comb_verh, comb_verl, comb_offset;
714 
715 	memset(fw_vers, 0, sizeof(struct e1000_fw_version));
716 
717 	/* basic eeprom version numbers and bits used vary by part and by tool
718 	 * used to create the nvm images. Check which data format we have.
719 	 */
720 	hw->nvm.ops.read(hw, NVM_ETRACK_HIWORD, 1, &etrack_test);
721 	switch (hw->mac.type) {
722 	case e1000_i211:
723 		igb_read_invm_version(hw, fw_vers);
724 		return;
725 	case e1000_82575:
726 	case e1000_82576:
727 	case e1000_82580:
728 		/* Use this format, unless EETRACK ID exists,
729 		 * then use alternate format
730 		 */
731 		if ((etrack_test &  NVM_MAJOR_MASK) != NVM_ETRACK_VALID) {
732 			hw->nvm.ops.read(hw, NVM_VERSION, 1, &fw_version);
733 			fw_vers->eep_major = (fw_version & NVM_MAJOR_MASK)
734 					      >> NVM_MAJOR_SHIFT;
735 			fw_vers->eep_minor = (fw_version & NVM_MINOR_MASK)
736 					      >> NVM_MINOR_SHIFT;
737 			fw_vers->eep_build = (fw_version & NVM_IMAGE_ID_MASK);
738 			goto etrack_id;
739 		}
740 		break;
741 	case e1000_i210:
742 		if (!(igb_get_flash_presence_i210(hw))) {
743 			igb_read_invm_version(hw, fw_vers);
744 			return;
745 		}
746 		/* fall through */
747 	case e1000_i350:
748 		/* find combo image version */
749 		hw->nvm.ops.read(hw, NVM_COMB_VER_PTR, 1, &comb_offset);
750 		if ((comb_offset != 0x0) &&
751 		    (comb_offset != NVM_VER_INVALID)) {
752 
753 			hw->nvm.ops.read(hw, (NVM_COMB_VER_OFF + comb_offset
754 					 + 1), 1, &comb_verh);
755 			hw->nvm.ops.read(hw, (NVM_COMB_VER_OFF + comb_offset),
756 					 1, &comb_verl);
757 
758 			/* get Option Rom version if it exists and is valid */
759 			if ((comb_verh && comb_verl) &&
760 			    ((comb_verh != NVM_VER_INVALID) &&
761 			     (comb_verl != NVM_VER_INVALID))) {
762 
763 				fw_vers->or_valid = true;
764 				fw_vers->or_major =
765 					comb_verl >> NVM_COMB_VER_SHFT;
766 				fw_vers->or_build =
767 					(comb_verl << NVM_COMB_VER_SHFT)
768 					| (comb_verh >> NVM_COMB_VER_SHFT);
769 				fw_vers->or_patch =
770 					comb_verh & NVM_COMB_VER_MASK;
771 			}
772 		}
773 		break;
774 	default:
775 		return;
776 	}
777 	hw->nvm.ops.read(hw, NVM_VERSION, 1, &fw_version);
778 	fw_vers->eep_major = (fw_version & NVM_MAJOR_MASK)
779 			      >> NVM_MAJOR_SHIFT;
780 
781 	/* check for old style version format in newer images*/
782 	if ((fw_version & NVM_NEW_DEC_MASK) == 0x0) {
783 		eeprom_verl = (fw_version & NVM_COMB_VER_MASK);
784 	} else {
785 		eeprom_verl = (fw_version & NVM_MINOR_MASK)
786 				>> NVM_MINOR_SHIFT;
787 	}
788 	/* Convert minor value to hex before assigning to output struct
789 	 * Val to be converted will not be higher than 99, per tool output
790 	 */
791 	q = eeprom_verl / NVM_HEX_CONV;
792 	hval = q * NVM_HEX_TENS;
793 	rem = eeprom_verl % NVM_HEX_CONV;
794 	result = hval + rem;
795 	fw_vers->eep_minor = result;
796 
797 etrack_id:
798 	if ((etrack_test &  NVM_MAJOR_MASK) == NVM_ETRACK_VALID) {
799 		hw->nvm.ops.read(hw, NVM_ETRACK_WORD, 1, &eeprom_verl);
800 		hw->nvm.ops.read(hw, (NVM_ETRACK_WORD + 1), 1, &eeprom_verh);
801 		fw_vers->etrack_id = (eeprom_verh << NVM_ETRACK_SHIFT)
802 			| eeprom_verl;
803 	}
804 	return;
805 }
806