diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/mips/sgi-ip22/ip22-nvram.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/mips/sgi-ip22/ip22-nvram.c')
-rw-r--r-- | arch/mips/sgi-ip22/ip22-nvram.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/arch/mips/sgi-ip22/ip22-nvram.c b/arch/mips/sgi-ip22/ip22-nvram.c new file mode 100644 index 000000000000..de43e86fa17c --- /dev/null +++ b/arch/mips/sgi-ip22/ip22-nvram.c | |||
@@ -0,0 +1,119 @@ | |||
1 | /* | ||
2 | * ip22-nvram.c: NVRAM and serial EEPROM handling. | ||
3 | * | ||
4 | * Copyright (C) 2003 Ladislav Michl (ladis@linux-mips.org) | ||
5 | */ | ||
6 | #include <linux/module.h> | ||
7 | |||
8 | #include <asm/sgi/hpc3.h> | ||
9 | #include <asm/sgi/ip22.h> | ||
10 | |||
11 | /* Control opcode for serial eeprom */ | ||
12 | #define EEPROM_READ 0xc000 /* serial memory read */ | ||
13 | #define EEPROM_WEN 0x9800 /* write enable before prog modes */ | ||
14 | #define EEPROM_WRITE 0xa000 /* serial memory write */ | ||
15 | #define EEPROM_WRALL 0x8800 /* write all registers */ | ||
16 | #define EEPROM_WDS 0x8000 /* disable all programming */ | ||
17 | #define EEPROM_PRREAD 0xc000 /* read protect register */ | ||
18 | #define EEPROM_PREN 0x9800 /* enable protect register mode */ | ||
19 | #define EEPROM_PRCLEAR 0xffff /* clear protect register */ | ||
20 | #define EEPROM_PRWRITE 0xa000 /* write protect register */ | ||
21 | #define EEPROM_PRDS 0x8000 /* disable protect register, forever */ | ||
22 | |||
23 | #define EEPROM_EPROT 0x01 /* Protect register enable */ | ||
24 | #define EEPROM_CSEL 0x02 /* Chip select */ | ||
25 | #define EEPROM_ECLK 0x04 /* EEPROM clock */ | ||
26 | #define EEPROM_DATO 0x08 /* Data out */ | ||
27 | #define EEPROM_DATI 0x10 /* Data in */ | ||
28 | |||
29 | /* We need to use these functions early... */ | ||
30 | #define delay() ({ \ | ||
31 | int x; \ | ||
32 | for (x=0; x<100000; x++) __asm__ __volatile__(""); }) | ||
33 | |||
34 | #define eeprom_cs_on(ptr) ({ \ | ||
35 | *ptr &= ~EEPROM_DATO; \ | ||
36 | *ptr &= ~EEPROM_ECLK; \ | ||
37 | *ptr &= ~EEPROM_EPROT; \ | ||
38 | delay(); \ | ||
39 | *ptr |= EEPROM_CSEL; \ | ||
40 | *ptr |= EEPROM_ECLK; }) | ||
41 | |||
42 | |||
43 | #define eeprom_cs_off(ptr) ({ \ | ||
44 | *ptr &= ~EEPROM_ECLK; \ | ||
45 | *ptr &= ~EEPROM_CSEL; \ | ||
46 | *ptr |= EEPROM_EPROT; \ | ||
47 | *ptr |= EEPROM_ECLK; }) | ||
48 | |||
49 | #define BITS_IN_COMMAND 11 | ||
50 | /* | ||
51 | * clock in the nvram command and the register number. For the | ||
52 | * national semiconductor nv ram chip the op code is 3 bits and | ||
53 | * the address is 6/8 bits. | ||
54 | */ | ||
55 | static inline void eeprom_cmd(volatile unsigned int *ctrl, unsigned cmd, | ||
56 | unsigned reg) | ||
57 | { | ||
58 | unsigned short ser_cmd; | ||
59 | int i; | ||
60 | |||
61 | ser_cmd = cmd | (reg << (16 - BITS_IN_COMMAND)); | ||
62 | for (i = 0; i < BITS_IN_COMMAND; i++) { | ||
63 | if (ser_cmd & (1<<15)) /* if high order bit set */ | ||
64 | *ctrl |= EEPROM_DATO; | ||
65 | else | ||
66 | *ctrl &= ~EEPROM_DATO; | ||
67 | *ctrl &= ~EEPROM_ECLK; | ||
68 | *ctrl |= EEPROM_ECLK; | ||
69 | ser_cmd <<= 1; | ||
70 | } | ||
71 | *ctrl &= ~EEPROM_DATO; /* see data sheet timing diagram */ | ||
72 | } | ||
73 | |||
74 | unsigned short ip22_eeprom_read(volatile unsigned int *ctrl, int reg) | ||
75 | { | ||
76 | unsigned short res = 0; | ||
77 | int i; | ||
78 | |||
79 | *ctrl &= ~EEPROM_EPROT; | ||
80 | eeprom_cs_on(ctrl); | ||
81 | eeprom_cmd(ctrl, EEPROM_READ, reg); | ||
82 | |||
83 | /* clock the data ouf of serial mem */ | ||
84 | for (i = 0; i < 16; i++) { | ||
85 | *ctrl &= ~EEPROM_ECLK; | ||
86 | delay(); | ||
87 | *ctrl |= EEPROM_ECLK; | ||
88 | delay(); | ||
89 | res <<= 1; | ||
90 | if (*ctrl & EEPROM_DATI) | ||
91 | res |= 1; | ||
92 | } | ||
93 | |||
94 | eeprom_cs_off(ctrl); | ||
95 | |||
96 | return res; | ||
97 | } | ||
98 | |||
99 | EXPORT_SYMBOL(ip22_eeprom_read); | ||
100 | |||
101 | /* | ||
102 | * Read specified register from main NVRAM | ||
103 | */ | ||
104 | unsigned short ip22_nvram_read(int reg) | ||
105 | { | ||
106 | if (ip22_is_fullhouse()) | ||
107 | /* IP22 (Indigo2 aka FullHouse) stores env variables into | ||
108 | * 93CS56 Microwire Bus EEPROM 2048 Bit (128x16) */ | ||
109 | return ip22_eeprom_read(&hpc3c0->eeprom, reg); | ||
110 | else { | ||
111 | unsigned short tmp; | ||
112 | /* IP24 (Indy aka Guiness) uses DS1386 8K version */ | ||
113 | reg <<= 1; | ||
114 | tmp = hpc3c0->bbram[reg++] & 0xff; | ||
115 | return (tmp << 8) | (hpc3c0->bbram[reg] & 0xff); | ||
116 | } | ||
117 | } | ||
118 | |||
119 | EXPORT_SYMBOL(ip22_nvram_read); | ||