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Commit | Line | Data |
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7a8e9bed WD |
1 | |
2 | #include <common.h> | |
8907b8db GR |
3 | #include <asm/ic/ssi.h> |
4 | #include <ds1722.h> | |
58b74b05 | 5 | |
7a8e9bed WD |
6 | static void ds1722_select(int dev) |
7 | { | |
8 | ssi_set_interface(4096, 0, 0, 0); | |
9 | ssi_chip_select(0); | |
10 | udelay(1); | |
11 | ssi_chip_select(dev); | |
12 | udelay(1); | |
13 | } | |
14 | ||
15 | ||
16 | u8 ds1722_read(int dev, int addr) | |
17 | { | |
18 | u8 res; | |
8bde7f77 | 19 | |
7a8e9bed | 20 | ds1722_select(dev); |
8bde7f77 WD |
21 | |
22 | ssi_tx_byte(addr); | |
23 | res = ssi_rx_byte(); | |
24 | ||
7a8e9bed | 25 | ssi_chip_select(0); |
8bde7f77 | 26 | |
7a8e9bed WD |
27 | return res; |
28 | } | |
29 | ||
30 | void ds1722_write(int dev, int addr, u8 data) | |
31 | { | |
32 | ds1722_select(dev); | |
8bde7f77 WD |
33 | |
34 | ssi_tx_byte(0x80|addr); | |
35 | ssi_tx_byte(data); | |
36 | ||
7a8e9bed WD |
37 | ssi_chip_select(0); |
38 | } | |
39 | ||
40 | ||
41 | u16 ds1722_temp(int dev, int resolution) | |
42 | { | |
43 | static int useconds[] = { | |
8bde7f77 | 44 | 75000, 150000, 300000, 600000, 1200000 |
7a8e9bed WD |
45 | }; |
46 | char temp; | |
47 | u16 res; | |
8bde7f77 WD |
48 | |
49 | ||
7a8e9bed WD |
50 | /* set up the desired resulotion ... */ |
51 | ds1722_write(dev, 0, 0xe0 | (resolution << 1)); | |
8bde7f77 | 52 | |
7a8e9bed | 53 | /* wait while the chip measures the tremperature */ |
8bde7f77 WD |
54 | udelay(useconds[resolution]); |
55 | ||
7a8e9bed | 56 | res = (temp = ds1722_read(dev, 2)) << 8; |
8bde7f77 WD |
57 | |
58 | if (temp < 0) { | |
7a8e9bed WD |
59 | temp = (16 - (ds1722_read(dev, 1) >> 4)) & 0x0f; |
60 | } else { | |
61 | temp = (ds1722_read(dev, 1) >> 4); | |
62 | } | |
8bde7f77 | 63 | |
7a8e9bed WD |
64 | switch (temp) { |
65 | case 0: | |
66 | /* .0000 */ | |
67 | break; | |
68 | case 1: | |
69 | /* .0625 */ | |
70 | res |=1; | |
71 | break; | |
72 | case 2: | |
73 | /* .1250 */ | |
74 | res |=1; | |
75 | break; | |
76 | case 3: | |
77 | /* .1875 */ | |
78 | res |=2; | |
79 | break; | |
80 | case 4: | |
81 | /* .2500 */ | |
82 | res |=3; | |
83 | break; | |
84 | case 5: | |
85 | /* .3125 */ | |
86 | res |=3; | |
87 | break; | |
88 | case 6: | |
89 | /* .3750 */ | |
90 | res |=4; | |
91 | break; | |
92 | case 7: | |
93 | /* .4375 */ | |
94 | res |=4; | |
95 | break; | |
96 | case 8: | |
97 | /* .5000 */ | |
98 | res |=5; | |
99 | break; | |
100 | case 9: | |
101 | /* .5625 */ | |
102 | res |=6; | |
103 | break; | |
104 | case 10: | |
105 | /* .6250 */ | |
106 | res |=6; | |
107 | break; | |
108 | case 11: | |
109 | /* .6875 */ | |
110 | res |=7; | |
111 | break; | |
112 | case 12: | |
113 | /* .7500 */ | |
114 | res |=8; | |
115 | break; | |
116 | case 13: | |
117 | /* .8125 */ | |
118 | res |=8; | |
119 | break; | |
120 | case 14: | |
121 | /* .8750 */ | |
122 | res |=9; | |
123 | break; | |
124 | case 15: | |
125 | /* .9375 */ | |
126 | res |=9; | |
127 | break; | |
128 | } | |
129 | return res; | |
8bde7f77 | 130 | |
7a8e9bed WD |
131 | } |
132 | ||
133 | int ds1722_probe(int dev) | |
134 | { | |
135 | u16 temp = ds1722_temp(dev, DS1722_RESOLUTION_12BIT); | |
136 | printf("%d.%d deg C\n\n", (char)(temp >> 8), temp & 0xff); | |
137 | return 0; | |
138 | } |