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Commit | Line | Data |
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9e2c3471 | 1 | /* |
7754f33c | 2 | * (C) Copyright 2007-2008 |
9e2c3471 LJ |
3 | * Larry Johnson, [email protected] |
4 | * | |
5 | * based on dtt/lm75.c which is ... | |
6 | * | |
7 | * (C) Copyright 2001 | |
8 | * Bill Hunter, Wave 7 Optics, [email protected] | |
9 | * | |
1a459660 | 10 | * SPDX-License-Identifier: GPL-2.0+ |
9e2c3471 LJ |
11 | */ |
12 | ||
13 | /* | |
14 | * National Semiconductor LM73 Temperature Sensor | |
15 | */ | |
16 | ||
17 | #include <common.h> | |
9e2c3471 LJ |
18 | #include <i2c.h> |
19 | #include <dtt.h> | |
20 | ||
21 | /* | |
22 | * Device code | |
23 | */ | |
24 | #define DTT_I2C_DEV_CODE 0x48 /* National Semi's LM73 device */ | |
6ecbb45b MS |
25 | #define DTT_READ_TEMP 0x0 |
26 | #define DTT_CONFIG 0x1 | |
27 | #define DTT_TEMP_HIGH 0x2 | |
28 | #define DTT_TEMP_LOW 0x3 | |
29 | #define DTT_CONTROL 0x4 | |
30 | #define DTT_ID 0x7 | |
9e2c3471 | 31 | |
7754f33c | 32 | int dtt_read(int const sensor, int const reg) |
9e2c3471 LJ |
33 | { |
34 | int dlen; | |
7754f33c | 35 | uint8_t data[2]; |
9e2c3471 LJ |
36 | |
37 | /* | |
38 | * Validate 'reg' param and get register size. | |
39 | */ | |
40 | switch (reg) { | |
41 | case DTT_CONFIG: | |
42 | case DTT_CONTROL: | |
43 | dlen = 1; | |
44 | break; | |
45 | case DTT_READ_TEMP: | |
46 | case DTT_TEMP_HIGH: | |
47 | case DTT_TEMP_LOW: | |
48 | case DTT_ID: | |
49 | dlen = 2; | |
50 | break; | |
51 | default: | |
52 | return -1; | |
53 | } | |
54 | /* | |
7754f33c | 55 | * Try to read the register at the calculated sensor address. |
9e2c3471 | 56 | */ |
7754f33c LJ |
57 | if (0 != |
58 | i2c_read(DTT_I2C_DEV_CODE + (sensor & 0x07), reg, 1, data, dlen)) | |
9e2c3471 LJ |
59 | return -1; |
60 | /* | |
61 | * Handle 2 byte result. | |
62 | */ | |
63 | if (2 == dlen) | |
7754f33c | 64 | return (int)((unsigned)data[0] << 8 | (unsigned)data[1]); |
9e2c3471 LJ |
65 | |
66 | return (int)data[0]; | |
67 | } /* dtt_read() */ | |
68 | ||
7754f33c | 69 | int dtt_write(int const sensor, int const reg, int const val) |
9e2c3471 LJ |
70 | { |
71 | int dlen; | |
7754f33c | 72 | uint8_t data[2]; |
9e2c3471 LJ |
73 | |
74 | /* | |
75 | * Validate 'reg' param and handle register size | |
76 | */ | |
77 | switch (reg) { | |
78 | case DTT_CONFIG: | |
79 | case DTT_CONTROL: | |
80 | dlen = 1; | |
7754f33c | 81 | data[0] = (uint8_t) val; |
9e2c3471 LJ |
82 | break; |
83 | case DTT_TEMP_HIGH: | |
84 | case DTT_TEMP_LOW: | |
85 | dlen = 2; | |
7754f33c LJ |
86 | data[0] = (uint8_t) (val >> 8); /* MSB first */ |
87 | data[1] = (uint8_t) val; | |
9e2c3471 LJ |
88 | break; |
89 | default: | |
90 | return -1; | |
91 | } | |
92 | /* | |
7754f33c | 93 | * Write value to register at the calculated sensor address. |
9e2c3471 | 94 | */ |
7754f33c LJ |
95 | return 0 != i2c_write(DTT_I2C_DEV_CODE + (sensor & 0x07), reg, 1, data, |
96 | dlen); | |
9e2c3471 LJ |
97 | } /* dtt_write() */ |
98 | ||
780f13a9 | 99 | int dtt_init_one(int const sensor) |
9e2c3471 LJ |
100 | { |
101 | int val; | |
102 | ||
103 | /* | |
104 | * Validate the Identification register | |
105 | */ | |
106 | if (0x0190 != dtt_read(sensor, DTT_ID)) | |
7754f33c | 107 | return -1; |
9e2c3471 LJ |
108 | /* |
109 | * Setup THIGH (upper-limit) and TLOW (lower-limit) registers | |
110 | */ | |
6d0f6bcf | 111 | val = CONFIG_SYS_DTT_MAX_TEMP << 7; |
9e2c3471 | 112 | if (dtt_write(sensor, DTT_TEMP_HIGH, val)) |
7754f33c | 113 | return -1; |
9e2c3471 | 114 | |
6d0f6bcf | 115 | val = CONFIG_SYS_DTT_MIN_TEMP << 7; |
9e2c3471 | 116 | if (dtt_write(sensor, DTT_TEMP_LOW, val)) |
7754f33c | 117 | return -1; |
9e2c3471 LJ |
118 | /* |
119 | * Setup configuraton register | |
120 | */ | |
121 | /* config = alert active low, disabled, and reset */ | |
122 | val = 0x64; | |
123 | if (dtt_write(sensor, DTT_CONFIG, val)) | |
7754f33c | 124 | return -1; |
9e2c3471 LJ |
125 | /* |
126 | * Setup control/status register | |
127 | */ | |
128 | /* control = temp resolution 0.25C */ | |
129 | val = 0x00; | |
130 | if (dtt_write(sensor, DTT_CONTROL, val)) | |
7754f33c | 131 | return -1; |
9e2c3471 LJ |
132 | |
133 | dtt_read(sensor, DTT_CONTROL); /* clear temperature flags */ | |
134 | return 0; | |
780f13a9 | 135 | } /* dtt_init_one() */ |
9e2c3471 | 136 | |
7754f33c | 137 | int dtt_get_temp(int const sensor) |
9e2c3471 | 138 | { |
7754f33c LJ |
139 | int const ret = dtt_read(sensor, DTT_READ_TEMP); |
140 | ||
141 | if (ret < 0) { | |
142 | printf("DTT temperature read failed.\n"); | |
143 | return 0; | |
144 | } | |
145 | return (int)((int16_t) ret + 0x0040) >> 7; | |
9e2c3471 | 146 | } /* dtt_get_temp() */ |