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/lasat/ds1603.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/lasat/ds1603.c')
-rw-r--r-- | arch/mips/lasat/ds1603.c | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/arch/mips/lasat/ds1603.c b/arch/mips/lasat/ds1603.c new file mode 100644 index 000000000000..7bbf6cf923c9 --- /dev/null +++ b/arch/mips/lasat/ds1603.c | |||
@@ -0,0 +1,174 @@ | |||
1 | /* | ||
2 | * Dallas Semiconductors 1603 RTC driver | ||
3 | * | ||
4 | * Brian Murphy <brian@murphy.dk> | ||
5 | * | ||
6 | */ | ||
7 | #include <linux/kernel.h> | ||
8 | #include <asm/lasat/lasat.h> | ||
9 | #include <linux/delay.h> | ||
10 | #include <asm/lasat/ds1603.h> | ||
11 | |||
12 | #include "ds1603.h" | ||
13 | |||
14 | #define READ_TIME_CMD 0x81 | ||
15 | #define SET_TIME_CMD 0x80 | ||
16 | #define TRIMMER_SET_CMD 0xC0 | ||
17 | #define TRIMMER_VALUE_MASK 0x38 | ||
18 | #define TRIMMER_SHIFT 3 | ||
19 | |||
20 | struct ds_defs *ds1603 = NULL; | ||
21 | |||
22 | /* HW specific register functions */ | ||
23 | static void rtc_reg_write(unsigned long val) | ||
24 | { | ||
25 | *ds1603->reg = val; | ||
26 | } | ||
27 | |||
28 | static unsigned long rtc_reg_read(void) | ||
29 | { | ||
30 | unsigned long tmp = *ds1603->reg; | ||
31 | return tmp; | ||
32 | } | ||
33 | |||
34 | static unsigned long rtc_datareg_read(void) | ||
35 | { | ||
36 | unsigned long tmp = *ds1603->data_reg; | ||
37 | return tmp; | ||
38 | } | ||
39 | |||
40 | static void rtc_nrst_high(void) | ||
41 | { | ||
42 | rtc_reg_write(rtc_reg_read() | ds1603->rst); | ||
43 | } | ||
44 | |||
45 | static void rtc_nrst_low(void) | ||
46 | { | ||
47 | rtc_reg_write(rtc_reg_read() & ~ds1603->rst); | ||
48 | } | ||
49 | |||
50 | static void rtc_cycle_clock(unsigned long data) | ||
51 | { | ||
52 | data |= ds1603->clk; | ||
53 | rtc_reg_write(data); | ||
54 | lasat_ndelay(250); | ||
55 | if (ds1603->data_reversed) | ||
56 | data &= ~ds1603->data; | ||
57 | else | ||
58 | data |= ds1603->data; | ||
59 | data &= ~ds1603->clk; | ||
60 | rtc_reg_write(data); | ||
61 | lasat_ndelay(250 + ds1603->huge_delay); | ||
62 | } | ||
63 | |||
64 | static void rtc_write_databit(unsigned int bit) | ||
65 | { | ||
66 | unsigned long data = rtc_reg_read(); | ||
67 | if (ds1603->data_reversed) | ||
68 | bit = !bit; | ||
69 | if (bit) | ||
70 | data |= ds1603->data; | ||
71 | else | ||
72 | data &= ~ds1603->data; | ||
73 | |||
74 | rtc_reg_write(data); | ||
75 | lasat_ndelay(50 + ds1603->huge_delay); | ||
76 | rtc_cycle_clock(data); | ||
77 | } | ||
78 | |||
79 | static unsigned int rtc_read_databit(void) | ||
80 | { | ||
81 | unsigned int data; | ||
82 | |||
83 | data = (rtc_datareg_read() & (1 << ds1603->data_read_shift)) | ||
84 | >> ds1603->data_read_shift; | ||
85 | rtc_cycle_clock(rtc_reg_read()); | ||
86 | return data; | ||
87 | } | ||
88 | |||
89 | static void rtc_write_byte(unsigned int byte) | ||
90 | { | ||
91 | int i; | ||
92 | |||
93 | for (i = 0; i<=7; i++) { | ||
94 | rtc_write_databit(byte & 1L); | ||
95 | byte >>= 1; | ||
96 | } | ||
97 | } | ||
98 | |||
99 | static void rtc_write_word(unsigned long word) | ||
100 | { | ||
101 | int i; | ||
102 | |||
103 | for (i = 0; i<=31; i++) { | ||
104 | rtc_write_databit(word & 1L); | ||
105 | word >>= 1; | ||
106 | } | ||
107 | } | ||
108 | |||
109 | static unsigned long rtc_read_word(void) | ||
110 | { | ||
111 | int i; | ||
112 | unsigned long word = 0; | ||
113 | unsigned long shift = 0; | ||
114 | |||
115 | for (i = 0; i<=31; i++) { | ||
116 | word |= rtc_read_databit() << shift; | ||
117 | shift++; | ||
118 | } | ||
119 | return word; | ||
120 | } | ||
121 | |||
122 | static void rtc_init_op(void) | ||
123 | { | ||
124 | rtc_nrst_high(); | ||
125 | |||
126 | rtc_reg_write(rtc_reg_read() & ~ds1603->clk); | ||
127 | |||
128 | lasat_ndelay(50); | ||
129 | } | ||
130 | |||
131 | static void rtc_end_op(void) | ||
132 | { | ||
133 | rtc_nrst_low(); | ||
134 | lasat_ndelay(1000); | ||
135 | } | ||
136 | |||
137 | /* interface */ | ||
138 | unsigned long ds1603_read(void) | ||
139 | { | ||
140 | unsigned long word; | ||
141 | rtc_init_op(); | ||
142 | rtc_write_byte(READ_TIME_CMD); | ||
143 | word = rtc_read_word(); | ||
144 | rtc_end_op(); | ||
145 | return word; | ||
146 | } | ||
147 | |||
148 | int ds1603_set(unsigned long time) | ||
149 | { | ||
150 | rtc_init_op(); | ||
151 | rtc_write_byte(SET_TIME_CMD); | ||
152 | rtc_write_word(time); | ||
153 | rtc_end_op(); | ||
154 | |||
155 | return 0; | ||
156 | } | ||
157 | |||
158 | void ds1603_set_trimmer(unsigned int trimval) | ||
159 | { | ||
160 | rtc_init_op(); | ||
161 | rtc_write_byte(((trimval << TRIMMER_SHIFT) & TRIMMER_VALUE_MASK) | ||
162 | | (TRIMMER_SET_CMD)); | ||
163 | rtc_end_op(); | ||
164 | } | ||
165 | |||
166 | void ds1603_disable(void) | ||
167 | { | ||
168 | ds1603_set_trimmer(TRIMMER_DISABLE_RTC); | ||
169 | } | ||
170 | |||
171 | void ds1603_enable(void) | ||
172 | { | ||
173 | ds1603_set_trimmer(TRIMMER_DEFAULT); | ||
174 | } | ||