1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2010-2013 Bluecherry, LLC <https://www.bluecherrydvr.com>
4  *
5  * Original author:
6  * Ben Collins <bcollins@ubuntu.com>
7  *
8  * Additional work by:
9  * John Brooks <john.brooks@bluecherry.net>
10  */
11 
12 #include <linux/kernel.h>
13 #include <linux/delay.h>
14 
15 #include "solo6x10.h"
16 
17 /* Control */
18 #define EE_SHIFT_CLK	0x04
19 #define EE_CS		0x08
20 #define EE_DATA_WRITE	0x02
21 #define EE_DATA_READ	0x01
22 #define EE_ENB		(0x80 | EE_CS)
23 
24 #define eeprom_delay()	udelay(100)
25 #if 0
26 #define eeprom_delay()	solo_reg_read(solo_dev, SOLO_EEPROM_CTRL)
27 #define eeprom_delay()	({				\
28 	int i, ret;					\
29 	udelay(100);					\
30 	for (i = ret = 0; i < 1000 && !ret; i++)	\
31 		ret = solo_eeprom_reg_read(solo_dev);	\
32 })
33 #endif
34 #define ADDR_LEN	6
35 
36 /* Commands */
37 #define EE_EWEN_CMD	4
38 #define EE_EWDS_CMD	4
39 #define EE_WRITE_CMD	5
40 #define EE_READ_CMD	6
41 #define EE_ERASE_CMD	7
42 
43 static unsigned int solo_eeprom_reg_read(struct solo_dev *solo_dev)
44 {
45 	return solo_reg_read(solo_dev, SOLO_EEPROM_CTRL) & EE_DATA_READ;
46 }
47 
48 static void solo_eeprom_reg_write(struct solo_dev *solo_dev, u32 data)
49 {
50 	solo_reg_write(solo_dev, SOLO_EEPROM_CTRL, data);
51 	eeprom_delay();
52 }
53 
54 static void solo_eeprom_cmd(struct solo_dev *solo_dev, int cmd)
55 {
56 	int i;
57 
58 	solo_eeprom_reg_write(solo_dev, SOLO_EEPROM_ACCESS_EN);
59 	solo_eeprom_reg_write(solo_dev, SOLO_EEPROM_ENABLE);
60 
61 	for (i = 4 + ADDR_LEN; i >= 0; i--) {
62 		int dataval = (cmd & (1 << i)) ? EE_DATA_WRITE : 0;
63 
64 		solo_eeprom_reg_write(solo_dev, SOLO_EEPROM_ENABLE | dataval);
65 		solo_eeprom_reg_write(solo_dev, SOLO_EEPROM_ENABLE |
66 				      EE_SHIFT_CLK | dataval);
67 	}
68 
69 	solo_eeprom_reg_write(solo_dev, SOLO_EEPROM_ENABLE);
70 }
71 
72 unsigned int solo_eeprom_ewen(struct solo_dev *solo_dev, int w_en)
73 {
74 	int ewen_cmd = (w_en ? 0x3f : 0) | (EE_EWEN_CMD << ADDR_LEN);
75 	unsigned int retval = 0;
76 	int i;
77 
78 	solo_eeprom_cmd(solo_dev, ewen_cmd);
79 
80 	for (i = 0; i < 16; i++) {
81 		solo_eeprom_reg_write(solo_dev, SOLO_EEPROM_ENABLE |
82 				      EE_SHIFT_CLK);
83 		retval = (retval << 1) | solo_eeprom_reg_read(solo_dev);
84 		solo_eeprom_reg_write(solo_dev, SOLO_EEPROM_ENABLE);
85 		retval = (retval << 1) | solo_eeprom_reg_read(solo_dev);
86 	}
87 
88 	solo_eeprom_reg_write(solo_dev, ~EE_CS);
89 	retval = (retval << 1) | solo_eeprom_reg_read(solo_dev);
90 
91 	return retval;
92 }
93 
94 __be16 solo_eeprom_read(struct solo_dev *solo_dev, int loc)
95 {
96 	int read_cmd = loc | (EE_READ_CMD << ADDR_LEN);
97 	u16 retval = 0;
98 	int i;
99 
100 	solo_eeprom_cmd(solo_dev, read_cmd);
101 
102 	for (i = 0; i < 16; i++) {
103 		solo_eeprom_reg_write(solo_dev, SOLO_EEPROM_ENABLE |
104 				      EE_SHIFT_CLK);
105 		retval = (retval << 1) | solo_eeprom_reg_read(solo_dev);
106 		solo_eeprom_reg_write(solo_dev, SOLO_EEPROM_ENABLE);
107 	}
108 
109 	solo_eeprom_reg_write(solo_dev, ~EE_CS);
110 
111 	return (__force __be16)retval;
112 }
113 
114 int solo_eeprom_write(struct solo_dev *solo_dev, int loc,
115 		      __be16 data)
116 {
117 	int write_cmd = loc | (EE_WRITE_CMD << ADDR_LEN);
118 	unsigned int retval;
119 	int i;
120 
121 	solo_eeprom_cmd(solo_dev, write_cmd);
122 
123 	for (i = 15; i >= 0; i--) {
124 		unsigned int dataval = ((__force unsigned)data >> i) & 1;
125 
126 		solo_eeprom_reg_write(solo_dev, EE_ENB);
127 		solo_eeprom_reg_write(solo_dev,
128 				      EE_ENB | (dataval << 1) | EE_SHIFT_CLK);
129 	}
130 
131 	solo_eeprom_reg_write(solo_dev, EE_ENB);
132 	solo_eeprom_reg_write(solo_dev, ~EE_CS);
133 	solo_eeprom_reg_write(solo_dev, EE_ENB);
134 
135 	for (i = retval = 0; i < 10000 && !retval; i++)
136 		retval = solo_eeprom_reg_read(solo_dev);
137 
138 	solo_eeprom_reg_write(solo_dev, ~EE_CS);
139 
140 	return !retval;
141 }
142