xref: /linux/drivers/net/ethernet/intel/igc/igc_nvm.c (revision 816b02e63a759c4458edee142b721ab09c918b3d)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c)  2018 Intel Corporation */
3 
4 #include "igc_mac.h"
5 #include "igc_nvm.h"
6 
7 /**
8  * igc_poll_eerd_eewr_done - Poll for EEPROM read/write completion
9  * @hw: pointer to the HW structure
10  * @ee_reg: EEPROM flag for polling
11  *
12  * Polls the EEPROM status bit for either read or write completion based
13  * upon the value of 'ee_reg'.
14  */
15 static s32 igc_poll_eerd_eewr_done(struct igc_hw *hw, int ee_reg)
16 {
17 	s32 ret_val = -IGC_ERR_NVM;
18 	u32 attempts = 100000;
19 	u32 i, reg = 0;
20 
21 	for (i = 0; i < attempts; i++) {
22 		if (ee_reg == IGC_NVM_POLL_READ)
23 			reg = rd32(IGC_EERD);
24 		else
25 			reg = rd32(IGC_EEWR);
26 
27 		if (reg & IGC_NVM_RW_REG_DONE) {
28 			ret_val = 0;
29 			break;
30 		}
31 
32 		udelay(5);
33 	}
34 
35 	return ret_val;
36 }
37 
38 /**
39  * igc_read_nvm_eerd - Reads EEPROM using EERD register
40  * @hw: pointer to the HW structure
41  * @offset: offset of word in the EEPROM to read
42  * @words: number of words to read
43  * @data: word read from the EEPROM
44  *
45  * Reads a 16 bit word from the EEPROM using the EERD register.
46  */
47 s32 igc_read_nvm_eerd(struct igc_hw *hw, u16 offset, u16 words, u16 *data)
48 {
49 	struct igc_nvm_info *nvm = &hw->nvm;
50 	u32 i, eerd = 0;
51 	s32 ret_val = 0;
52 
53 	/* A check for invalid values:  offset too large, too many words,
54 	 * and not enough words.
55 	 */
56 	if (offset >= nvm->word_size || (words > (nvm->word_size - offset)) ||
57 	    words == 0) {
58 		hw_dbg("nvm parameter(s) out of bounds\n");
59 		ret_val = -IGC_ERR_NVM;
60 		goto out;
61 	}
62 
63 	for (i = 0; i < words; i++) {
64 		eerd = ((offset + i) << IGC_NVM_RW_ADDR_SHIFT) +
65 			IGC_NVM_RW_REG_START;
66 
67 		wr32(IGC_EERD, eerd);
68 		ret_val = igc_poll_eerd_eewr_done(hw, IGC_NVM_POLL_READ);
69 		if (ret_val)
70 			break;
71 
72 		data[i] = (rd32(IGC_EERD) >> IGC_NVM_RW_REG_DATA);
73 	}
74 
75 out:
76 	return ret_val;
77 }
78 
79 /**
80  * igc_read_mac_addr - Read device MAC address
81  * @hw: pointer to the HW structure
82  */
83 s32 igc_read_mac_addr(struct igc_hw *hw)
84 {
85 	u32 rar_high;
86 	u32 rar_low;
87 	u16 i;
88 
89 	rar_high = rd32(IGC_RAH(0));
90 	rar_low = rd32(IGC_RAL(0));
91 
92 	for (i = 0; i < IGC_RAL_MAC_ADDR_LEN; i++)
93 		hw->mac.perm_addr[i] = (u8)(rar_low >> (i * 8));
94 
95 	for (i = 0; i < IGC_RAH_MAC_ADDR_LEN; i++)
96 		hw->mac.perm_addr[i + 4] = (u8)(rar_high >> (i * 8));
97 
98 	for (i = 0; i < ETH_ALEN; i++)
99 		hw->mac.addr[i] = hw->mac.perm_addr[i];
100 
101 	return 0;
102 }
103 
104 /**
105  * igc_validate_nvm_checksum - Validate EEPROM checksum
106  * @hw: pointer to the HW structure
107  *
108  * Calculates the EEPROM checksum by reading/adding each word of the EEPROM
109  * and then verifies that the sum of the EEPROM is equal to 0xBABA.
110  */
111 s32 igc_validate_nvm_checksum(struct igc_hw *hw)
112 {
113 	u16 checksum = 0;
114 	u16 i, nvm_data;
115 	s32 ret_val = 0;
116 
117 	for (i = 0; i < (NVM_CHECKSUM_REG + 1); i++) {
118 		ret_val = hw->nvm.ops.read(hw, i, 1, &nvm_data);
119 		if (ret_val) {
120 			hw_dbg("NVM Read Error\n");
121 			goto out;
122 		}
123 		checksum += nvm_data;
124 	}
125 
126 	if (checksum != (u16)NVM_SUM) {
127 		hw_dbg("NVM Checksum Invalid\n");
128 		ret_val = -IGC_ERR_NVM;
129 		goto out;
130 	}
131 
132 out:
133 	return ret_val;
134 }
135 
136 /**
137  * igc_update_nvm_checksum - Update EEPROM checksum
138  * @hw: pointer to the HW structure
139  *
140  * Updates the EEPROM checksum by reading/adding each word of the EEPROM
141  * up to the checksum.  Then calculates the EEPROM checksum and writes the
142  * value to the EEPROM.
143  */
144 s32 igc_update_nvm_checksum(struct igc_hw *hw)
145 {
146 	u16 checksum = 0;
147 	u16 i, nvm_data;
148 	s32  ret_val;
149 
150 	for (i = 0; i < NVM_CHECKSUM_REG; i++) {
151 		ret_val = hw->nvm.ops.read(hw, i, 1, &nvm_data);
152 		if (ret_val) {
153 			hw_dbg("NVM Read Error while updating checksum.\n");
154 			goto out;
155 		}
156 		checksum += nvm_data;
157 	}
158 	checksum = (u16)NVM_SUM - checksum;
159 	ret_val = hw->nvm.ops.write(hw, NVM_CHECKSUM_REG, 1, &checksum);
160 	if (ret_val)
161 		hw_dbg("NVM Write Error while updating checksum.\n");
162 
163 out:
164 	return ret_val;
165 }
166