xref: /linux/drivers/net/ethernet/intel/e1000e/nvm.c (revision e9f0878c4b2004ac19581274c1ae4c61ae3ca70e)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright(c) 1999 - 2018 Intel Corporation. */
3 
4 #include "e1000.h"
5 
6 /**
7  *  e1000_raise_eec_clk - Raise EEPROM clock
8  *  @hw: pointer to the HW structure
9  *  @eecd: pointer to the EEPROM
10  *
11  *  Enable/Raise the EEPROM clock bit.
12  **/
13 static void e1000_raise_eec_clk(struct e1000_hw *hw, u32 *eecd)
14 {
15 	*eecd = *eecd | E1000_EECD_SK;
16 	ew32(EECD, *eecd);
17 	e1e_flush();
18 	udelay(hw->nvm.delay_usec);
19 }
20 
21 /**
22  *  e1000_lower_eec_clk - Lower EEPROM clock
23  *  @hw: pointer to the HW structure
24  *  @eecd: pointer to the EEPROM
25  *
26  *  Clear/Lower the EEPROM clock bit.
27  **/
28 static void e1000_lower_eec_clk(struct e1000_hw *hw, u32 *eecd)
29 {
30 	*eecd = *eecd & ~E1000_EECD_SK;
31 	ew32(EECD, *eecd);
32 	e1e_flush();
33 	udelay(hw->nvm.delay_usec);
34 }
35 
36 /**
37  *  e1000_shift_out_eec_bits - Shift data bits our to the EEPROM
38  *  @hw: pointer to the HW structure
39  *  @data: data to send to the EEPROM
40  *  @count: number of bits to shift out
41  *
42  *  We need to shift 'count' bits out to the EEPROM.  So, the value in the
43  *  "data" parameter will be shifted out to the EEPROM one bit at a time.
44  *  In order to do this, "data" must be broken down into bits.
45  **/
46 static void e1000_shift_out_eec_bits(struct e1000_hw *hw, u16 data, u16 count)
47 {
48 	struct e1000_nvm_info *nvm = &hw->nvm;
49 	u32 eecd = er32(EECD);
50 	u32 mask;
51 
52 	mask = BIT(count - 1);
53 	if (nvm->type == e1000_nvm_eeprom_spi)
54 		eecd |= E1000_EECD_DO;
55 
56 	do {
57 		eecd &= ~E1000_EECD_DI;
58 
59 		if (data & mask)
60 			eecd |= E1000_EECD_DI;
61 
62 		ew32(EECD, eecd);
63 		e1e_flush();
64 
65 		udelay(nvm->delay_usec);
66 
67 		e1000_raise_eec_clk(hw, &eecd);
68 		e1000_lower_eec_clk(hw, &eecd);
69 
70 		mask >>= 1;
71 	} while (mask);
72 
73 	eecd &= ~E1000_EECD_DI;
74 	ew32(EECD, eecd);
75 }
76 
77 /**
78  *  e1000_shift_in_eec_bits - Shift data bits in from the EEPROM
79  *  @hw: pointer to the HW structure
80  *  @count: number of bits to shift in
81  *
82  *  In order to read a register from the EEPROM, we need to shift 'count' bits
83  *  in from the EEPROM.  Bits are "shifted in" by raising the clock input to
84  *  the EEPROM (setting the SK bit), and then reading the value of the data out
85  *  "DO" bit.  During this "shifting in" process the data in "DI" bit should
86  *  always be clear.
87  **/
88 static u16 e1000_shift_in_eec_bits(struct e1000_hw *hw, u16 count)
89 {
90 	u32 eecd;
91 	u32 i;
92 	u16 data;
93 
94 	eecd = er32(EECD);
95 	eecd &= ~(E1000_EECD_DO | E1000_EECD_DI);
96 	data = 0;
97 
98 	for (i = 0; i < count; i++) {
99 		data <<= 1;
100 		e1000_raise_eec_clk(hw, &eecd);
101 
102 		eecd = er32(EECD);
103 
104 		eecd &= ~E1000_EECD_DI;
105 		if (eecd & E1000_EECD_DO)
106 			data |= 1;
107 
108 		e1000_lower_eec_clk(hw, &eecd);
109 	}
110 
111 	return data;
112 }
113 
114 /**
115  *  e1000e_poll_eerd_eewr_done - Poll for EEPROM read/write completion
116  *  @hw: pointer to the HW structure
117  *  @ee_reg: EEPROM flag for polling
118  *
119  *  Polls the EEPROM status bit for either read or write completion based
120  *  upon the value of 'ee_reg'.
121  **/
122 s32 e1000e_poll_eerd_eewr_done(struct e1000_hw *hw, int ee_reg)
123 {
124 	u32 attempts = 100000;
125 	u32 i, reg = 0;
126 
127 	for (i = 0; i < attempts; i++) {
128 		if (ee_reg == E1000_NVM_POLL_READ)
129 			reg = er32(EERD);
130 		else
131 			reg = er32(EEWR);
132 
133 		if (reg & E1000_NVM_RW_REG_DONE)
134 			return 0;
135 
136 		udelay(5);
137 	}
138 
139 	return -E1000_ERR_NVM;
140 }
141 
142 /**
143  *  e1000e_acquire_nvm - Generic request for access to EEPROM
144  *  @hw: pointer to the HW structure
145  *
146  *  Set the EEPROM access request bit and wait for EEPROM access grant bit.
147  *  Return successful if access grant bit set, else clear the request for
148  *  EEPROM access and return -E1000_ERR_NVM (-1).
149  **/
150 s32 e1000e_acquire_nvm(struct e1000_hw *hw)
151 {
152 	u32 eecd = er32(EECD);
153 	s32 timeout = E1000_NVM_GRANT_ATTEMPTS;
154 
155 	ew32(EECD, eecd | E1000_EECD_REQ);
156 	eecd = er32(EECD);
157 
158 	while (timeout) {
159 		if (eecd & E1000_EECD_GNT)
160 			break;
161 		udelay(5);
162 		eecd = er32(EECD);
163 		timeout--;
164 	}
165 
166 	if (!timeout) {
167 		eecd &= ~E1000_EECD_REQ;
168 		ew32(EECD, eecd);
169 		e_dbg("Could not acquire NVM grant\n");
170 		return -E1000_ERR_NVM;
171 	}
172 
173 	return 0;
174 }
175 
176 /**
177  *  e1000_standby_nvm - Return EEPROM to standby state
178  *  @hw: pointer to the HW structure
179  *
180  *  Return the EEPROM to a standby state.
181  **/
182 static void e1000_standby_nvm(struct e1000_hw *hw)
183 {
184 	struct e1000_nvm_info *nvm = &hw->nvm;
185 	u32 eecd = er32(EECD);
186 
187 	if (nvm->type == e1000_nvm_eeprom_spi) {
188 		/* Toggle CS to flush commands */
189 		eecd |= E1000_EECD_CS;
190 		ew32(EECD, eecd);
191 		e1e_flush();
192 		udelay(nvm->delay_usec);
193 		eecd &= ~E1000_EECD_CS;
194 		ew32(EECD, eecd);
195 		e1e_flush();
196 		udelay(nvm->delay_usec);
197 	}
198 }
199 
200 /**
201  *  e1000_stop_nvm - Terminate EEPROM command
202  *  @hw: pointer to the HW structure
203  *
204  *  Terminates the current command by inverting the EEPROM's chip select pin.
205  **/
206 static void e1000_stop_nvm(struct e1000_hw *hw)
207 {
208 	u32 eecd;
209 
210 	eecd = er32(EECD);
211 	if (hw->nvm.type == e1000_nvm_eeprom_spi) {
212 		/* Pull CS high */
213 		eecd |= E1000_EECD_CS;
214 		e1000_lower_eec_clk(hw, &eecd);
215 	}
216 }
217 
218 /**
219  *  e1000e_release_nvm - Release exclusive access to EEPROM
220  *  @hw: pointer to the HW structure
221  *
222  *  Stop any current commands to the EEPROM and clear the EEPROM request bit.
223  **/
224 void e1000e_release_nvm(struct e1000_hw *hw)
225 {
226 	u32 eecd;
227 
228 	e1000_stop_nvm(hw);
229 
230 	eecd = er32(EECD);
231 	eecd &= ~E1000_EECD_REQ;
232 	ew32(EECD, eecd);
233 }
234 
235 /**
236  *  e1000_ready_nvm_eeprom - Prepares EEPROM for read/write
237  *  @hw: pointer to the HW structure
238  *
239  *  Setups the EEPROM for reading and writing.
240  **/
241 static s32 e1000_ready_nvm_eeprom(struct e1000_hw *hw)
242 {
243 	struct e1000_nvm_info *nvm = &hw->nvm;
244 	u32 eecd = er32(EECD);
245 	u8 spi_stat_reg;
246 
247 	if (nvm->type == e1000_nvm_eeprom_spi) {
248 		u16 timeout = NVM_MAX_RETRY_SPI;
249 
250 		/* Clear SK and CS */
251 		eecd &= ~(E1000_EECD_CS | E1000_EECD_SK);
252 		ew32(EECD, eecd);
253 		e1e_flush();
254 		udelay(1);
255 
256 		/* Read "Status Register" repeatedly until the LSB is cleared.
257 		 * The EEPROM will signal that the command has been completed
258 		 * by clearing bit 0 of the internal status register.  If it's
259 		 * not cleared within 'timeout', then error out.
260 		 */
261 		while (timeout) {
262 			e1000_shift_out_eec_bits(hw, NVM_RDSR_OPCODE_SPI,
263 						 hw->nvm.opcode_bits);
264 			spi_stat_reg = (u8)e1000_shift_in_eec_bits(hw, 8);
265 			if (!(spi_stat_reg & NVM_STATUS_RDY_SPI))
266 				break;
267 
268 			udelay(5);
269 			e1000_standby_nvm(hw);
270 			timeout--;
271 		}
272 
273 		if (!timeout) {
274 			e_dbg("SPI NVM Status error\n");
275 			return -E1000_ERR_NVM;
276 		}
277 	}
278 
279 	return 0;
280 }
281 
282 /**
283  *  e1000e_read_nvm_eerd - Reads EEPROM using EERD register
284  *  @hw: pointer to the HW structure
285  *  @offset: offset of word in the EEPROM to read
286  *  @words: number of words to read
287  *  @data: word read from the EEPROM
288  *
289  *  Reads a 16 bit word from the EEPROM using the EERD register.
290  **/
291 s32 e1000e_read_nvm_eerd(struct e1000_hw *hw, u16 offset, u16 words, u16 *data)
292 {
293 	struct e1000_nvm_info *nvm = &hw->nvm;
294 	u32 i, eerd = 0;
295 	s32 ret_val = 0;
296 
297 	/* A check for invalid values:  offset too large, too many words,
298 	 * too many words for the offset, and not enough words.
299 	 */
300 	if ((offset >= nvm->word_size) || (words > (nvm->word_size - offset)) ||
301 	    (words == 0)) {
302 		e_dbg("nvm parameter(s) out of bounds\n");
303 		return -E1000_ERR_NVM;
304 	}
305 
306 	for (i = 0; i < words; i++) {
307 		eerd = ((offset + i) << E1000_NVM_RW_ADDR_SHIFT) +
308 		    E1000_NVM_RW_REG_START;
309 
310 		ew32(EERD, eerd);
311 		ret_val = e1000e_poll_eerd_eewr_done(hw, E1000_NVM_POLL_READ);
312 		if (ret_val) {
313 			e_dbg("NVM read error: %d\n", ret_val);
314 			break;
315 		}
316 
317 		data[i] = (er32(EERD) >> E1000_NVM_RW_REG_DATA);
318 	}
319 
320 	return ret_val;
321 }
322 
323 /**
324  *  e1000e_write_nvm_spi - Write to EEPROM using SPI
325  *  @hw: pointer to the HW structure
326  *  @offset: offset within the EEPROM to be written to
327  *  @words: number of words to write
328  *  @data: 16 bit word(s) to be written to the EEPROM
329  *
330  *  Writes data to EEPROM at offset using SPI interface.
331  *
332  *  If e1000e_update_nvm_checksum is not called after this function , the
333  *  EEPROM will most likely contain an invalid checksum.
334  **/
335 s32 e1000e_write_nvm_spi(struct e1000_hw *hw, u16 offset, u16 words, u16 *data)
336 {
337 	struct e1000_nvm_info *nvm = &hw->nvm;
338 	s32 ret_val = -E1000_ERR_NVM;
339 	u16 widx = 0;
340 
341 	/* A check for invalid values:  offset too large, too many words,
342 	 * and not enough words.
343 	 */
344 	if ((offset >= nvm->word_size) || (words > (nvm->word_size - offset)) ||
345 	    (words == 0)) {
346 		e_dbg("nvm parameter(s) out of bounds\n");
347 		return -E1000_ERR_NVM;
348 	}
349 
350 	while (widx < words) {
351 		u8 write_opcode = NVM_WRITE_OPCODE_SPI;
352 
353 		ret_val = nvm->ops.acquire(hw);
354 		if (ret_val)
355 			return ret_val;
356 
357 		ret_val = e1000_ready_nvm_eeprom(hw);
358 		if (ret_val) {
359 			nvm->ops.release(hw);
360 			return ret_val;
361 		}
362 
363 		e1000_standby_nvm(hw);
364 
365 		/* Send the WRITE ENABLE command (8 bit opcode) */
366 		e1000_shift_out_eec_bits(hw, NVM_WREN_OPCODE_SPI,
367 					 nvm->opcode_bits);
368 
369 		e1000_standby_nvm(hw);
370 
371 		/* Some SPI eeproms use the 8th address bit embedded in the
372 		 * opcode
373 		 */
374 		if ((nvm->address_bits == 8) && (offset >= 128))
375 			write_opcode |= NVM_A8_OPCODE_SPI;
376 
377 		/* Send the Write command (8-bit opcode + addr) */
378 		e1000_shift_out_eec_bits(hw, write_opcode, nvm->opcode_bits);
379 		e1000_shift_out_eec_bits(hw, (u16)((offset + widx) * 2),
380 					 nvm->address_bits);
381 
382 		/* Loop to allow for up to whole page write of eeprom */
383 		while (widx < words) {
384 			u16 word_out = data[widx];
385 
386 			word_out = (word_out >> 8) | (word_out << 8);
387 			e1000_shift_out_eec_bits(hw, word_out, 16);
388 			widx++;
389 
390 			if ((((offset + widx) * 2) % nvm->page_size) == 0) {
391 				e1000_standby_nvm(hw);
392 				break;
393 			}
394 		}
395 		usleep_range(10000, 20000);
396 		nvm->ops.release(hw);
397 	}
398 
399 	return ret_val;
400 }
401 
402 /**
403  *  e1000_read_pba_string_generic - Read device part number
404  *  @hw: pointer to the HW structure
405  *  @pba_num: pointer to device part number
406  *  @pba_num_size: size of part number buffer
407  *
408  *  Reads the product board assembly (PBA) number from the EEPROM and stores
409  *  the value in pba_num.
410  **/
411 s32 e1000_read_pba_string_generic(struct e1000_hw *hw, u8 *pba_num,
412 				  u32 pba_num_size)
413 {
414 	s32 ret_val;
415 	u16 nvm_data;
416 	u16 pba_ptr;
417 	u16 offset;
418 	u16 length;
419 
420 	if (pba_num == NULL) {
421 		e_dbg("PBA string buffer was null\n");
422 		return -E1000_ERR_INVALID_ARGUMENT;
423 	}
424 
425 	ret_val = e1000_read_nvm(hw, NVM_PBA_OFFSET_0, 1, &nvm_data);
426 	if (ret_val) {
427 		e_dbg("NVM Read Error\n");
428 		return ret_val;
429 	}
430 
431 	ret_val = e1000_read_nvm(hw, NVM_PBA_OFFSET_1, 1, &pba_ptr);
432 	if (ret_val) {
433 		e_dbg("NVM Read Error\n");
434 		return ret_val;
435 	}
436 
437 	/* if nvm_data is not ptr guard the PBA must be in legacy format which
438 	 * means pba_ptr is actually our second data word for the PBA number
439 	 * and we can decode it into an ascii string
440 	 */
441 	if (nvm_data != NVM_PBA_PTR_GUARD) {
442 		e_dbg("NVM PBA number is not stored as string\n");
443 
444 		/* make sure callers buffer is big enough to store the PBA */
445 		if (pba_num_size < E1000_PBANUM_LENGTH) {
446 			e_dbg("PBA string buffer too small\n");
447 			return E1000_ERR_NO_SPACE;
448 		}
449 
450 		/* extract hex string from data and pba_ptr */
451 		pba_num[0] = (nvm_data >> 12) & 0xF;
452 		pba_num[1] = (nvm_data >> 8) & 0xF;
453 		pba_num[2] = (nvm_data >> 4) & 0xF;
454 		pba_num[3] = nvm_data & 0xF;
455 		pba_num[4] = (pba_ptr >> 12) & 0xF;
456 		pba_num[5] = (pba_ptr >> 8) & 0xF;
457 		pba_num[6] = '-';
458 		pba_num[7] = 0;
459 		pba_num[8] = (pba_ptr >> 4) & 0xF;
460 		pba_num[9] = pba_ptr & 0xF;
461 
462 		/* put a null character on the end of our string */
463 		pba_num[10] = '\0';
464 
465 		/* switch all the data but the '-' to hex char */
466 		for (offset = 0; offset < 10; offset++) {
467 			if (pba_num[offset] < 0xA)
468 				pba_num[offset] += '0';
469 			else if (pba_num[offset] < 0x10)
470 				pba_num[offset] += 'A' - 0xA;
471 		}
472 
473 		return 0;
474 	}
475 
476 	ret_val = e1000_read_nvm(hw, pba_ptr, 1, &length);
477 	if (ret_val) {
478 		e_dbg("NVM Read Error\n");
479 		return ret_val;
480 	}
481 
482 	if (length == 0xFFFF || length == 0) {
483 		e_dbg("NVM PBA number section invalid length\n");
484 		return -E1000_ERR_NVM_PBA_SECTION;
485 	}
486 	/* check if pba_num buffer is big enough */
487 	if (pba_num_size < (((u32)length * 2) - 1)) {
488 		e_dbg("PBA string buffer too small\n");
489 		return -E1000_ERR_NO_SPACE;
490 	}
491 
492 	/* trim pba length from start of string */
493 	pba_ptr++;
494 	length--;
495 
496 	for (offset = 0; offset < length; offset++) {
497 		ret_val = e1000_read_nvm(hw, pba_ptr + offset, 1, &nvm_data);
498 		if (ret_val) {
499 			e_dbg("NVM Read Error\n");
500 			return ret_val;
501 		}
502 		pba_num[offset * 2] = (u8)(nvm_data >> 8);
503 		pba_num[(offset * 2) + 1] = (u8)(nvm_data & 0xFF);
504 	}
505 	pba_num[offset * 2] = '\0';
506 
507 	return 0;
508 }
509 
510 /**
511  *  e1000_read_mac_addr_generic - Read device MAC address
512  *  @hw: pointer to the HW structure
513  *
514  *  Reads the device MAC address from the EEPROM and stores the value.
515  *  Since devices with two ports use the same EEPROM, we increment the
516  *  last bit in the MAC address for the second port.
517  **/
518 s32 e1000_read_mac_addr_generic(struct e1000_hw *hw)
519 {
520 	u32 rar_high;
521 	u32 rar_low;
522 	u16 i;
523 
524 	rar_high = er32(RAH(0));
525 	rar_low = er32(RAL(0));
526 
527 	for (i = 0; i < E1000_RAL_MAC_ADDR_LEN; i++)
528 		hw->mac.perm_addr[i] = (u8)(rar_low >> (i * 8));
529 
530 	for (i = 0; i < E1000_RAH_MAC_ADDR_LEN; i++)
531 		hw->mac.perm_addr[i + 4] = (u8)(rar_high >> (i * 8));
532 
533 	for (i = 0; i < ETH_ALEN; i++)
534 		hw->mac.addr[i] = hw->mac.perm_addr[i];
535 
536 	return 0;
537 }
538 
539 /**
540  *  e1000e_validate_nvm_checksum_generic - Validate EEPROM checksum
541  *  @hw: pointer to the HW structure
542  *
543  *  Calculates the EEPROM checksum by reading/adding each word of the EEPROM
544  *  and then verifies that the sum of the EEPROM is equal to 0xBABA.
545  **/
546 s32 e1000e_validate_nvm_checksum_generic(struct e1000_hw *hw)
547 {
548 	s32 ret_val;
549 	u16 checksum = 0;
550 	u16 i, nvm_data;
551 
552 	for (i = 0; i < (NVM_CHECKSUM_REG + 1); i++) {
553 		ret_val = e1000_read_nvm(hw, i, 1, &nvm_data);
554 		if (ret_val) {
555 			e_dbg("NVM Read Error\n");
556 			return ret_val;
557 		}
558 		checksum += nvm_data;
559 	}
560 
561 	if (checksum != (u16)NVM_SUM) {
562 		e_dbg("NVM Checksum Invalid\n");
563 		return -E1000_ERR_NVM;
564 	}
565 
566 	return 0;
567 }
568 
569 /**
570  *  e1000e_update_nvm_checksum_generic - Update EEPROM checksum
571  *  @hw: pointer to the HW structure
572  *
573  *  Updates the EEPROM checksum by reading/adding each word of the EEPROM
574  *  up to the checksum.  Then calculates the EEPROM checksum and writes the
575  *  value to the EEPROM.
576  **/
577 s32 e1000e_update_nvm_checksum_generic(struct e1000_hw *hw)
578 {
579 	s32 ret_val;
580 	u16 checksum = 0;
581 	u16 i, nvm_data;
582 
583 	for (i = 0; i < NVM_CHECKSUM_REG; i++) {
584 		ret_val = e1000_read_nvm(hw, i, 1, &nvm_data);
585 		if (ret_val) {
586 			e_dbg("NVM Read Error while updating checksum.\n");
587 			return ret_val;
588 		}
589 		checksum += nvm_data;
590 	}
591 	checksum = (u16)NVM_SUM - checksum;
592 	ret_val = e1000_write_nvm(hw, NVM_CHECKSUM_REG, 1, &checksum);
593 	if (ret_val)
594 		e_dbg("NVM Write Error while updating checksum.\n");
595 
596 	return ret_val;
597 }
598 
599 /**
600  *  e1000e_reload_nvm_generic - Reloads EEPROM
601  *  @hw: pointer to the HW structure
602  *
603  *  Reloads the EEPROM by setting the "Reinitialize from EEPROM" bit in the
604  *  extended control register.
605  **/
606 void e1000e_reload_nvm_generic(struct e1000_hw *hw)
607 {
608 	u32 ctrl_ext;
609 
610 	usleep_range(10, 20);
611 	ctrl_ext = er32(CTRL_EXT);
612 	ctrl_ext |= E1000_CTRL_EXT_EE_RST;
613 	ew32(CTRL_EXT, ctrl_ext);
614 	e1e_flush();
615 }
616