diff options
Diffstat (limited to 'firmware/target/arm/i2c-telechips.c')
-rw-r--r-- | firmware/target/arm/i2c-telechips.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/firmware/target/arm/i2c-telechips.c b/firmware/target/arm/i2c-telechips.c new file mode 100644 index 0000000000..e3e8fd3d33 --- /dev/null +++ b/firmware/target/arm/i2c-telechips.c | |||
@@ -0,0 +1,187 @@ | |||
1 | /*************************************************************************** | ||
2 | * __________ __ ___. | ||
3 | * Open \______ \ ____ ____ | | _\_ |__ _______ ___ | ||
4 | * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / | ||
5 | * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < | ||
6 | * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ | ||
7 | * \/ \/ \/ \/ \/ | ||
8 | * $Id$ | ||
9 | * | ||
10 | * Copyright (C) 2008 by Rob Purchase | ||
11 | * | ||
12 | * All files in this archive are subject to the GNU General Public License. | ||
13 | * See the file COPYING in the source tree root for full license agreement. | ||
14 | * | ||
15 | * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY | ||
16 | * KIND, either express or implied. | ||
17 | * | ||
18 | ****************************************************************************/ | ||
19 | #include "config.h" | ||
20 | |||
21 | #include "system.h" | ||
22 | #include "i2c.h" | ||
23 | #include "i2c-target.h" | ||
24 | |||
25 | /* arbitrary delay loop */ | ||
26 | #define DELAY do { int _x; for(_x=0;_x<20;_x++);} while (0) | ||
27 | |||
28 | static struct mutex i2c_mtx; | ||
29 | |||
30 | void i2c_init(void) | ||
31 | { | ||
32 | /* nothing to do */ | ||
33 | } | ||
34 | |||
35 | void i2c_start(void) | ||
36 | { | ||
37 | SDA_OUTPUT; | ||
38 | |||
39 | SCL_HI; | ||
40 | SDA_HI; | ||
41 | DELAY; | ||
42 | |||
43 | SDA_LO; | ||
44 | DELAY; | ||
45 | SCL_LO; | ||
46 | DELAY; | ||
47 | } | ||
48 | |||
49 | void i2c_stop(void) | ||
50 | { | ||
51 | SDA_OUTPUT; | ||
52 | |||
53 | SDA_LO; | ||
54 | DELAY; | ||
55 | |||
56 | SCL_HI; | ||
57 | DELAY; | ||
58 | SDA_HI; | ||
59 | DELAY; | ||
60 | } | ||
61 | |||
62 | void i2c_outb(unsigned char byte) | ||
63 | { | ||
64 | int bit; | ||
65 | |||
66 | SDA_OUTPUT; | ||
67 | |||
68 | for (bit = 0; bit < 8; bit++) | ||
69 | { | ||
70 | if ((byte<<bit) & 0x80) | ||
71 | SDA_HI; | ||
72 | else | ||
73 | SDA_LO; | ||
74 | |||
75 | DELAY; | ||
76 | |||
77 | SCL_HI; | ||
78 | DELAY; | ||
79 | SCL_LO; | ||
80 | DELAY; | ||
81 | } | ||
82 | } | ||
83 | |||
84 | unsigned char i2c_inb(int ack) | ||
85 | { | ||
86 | int i; | ||
87 | unsigned char byte = 0; | ||
88 | |||
89 | SDA_INPUT; | ||
90 | |||
91 | /* clock in each bit, MSB first */ | ||
92 | for ( i=0x80; i; i>>=1 ) | ||
93 | { | ||
94 | SCL_HI; | ||
95 | DELAY; | ||
96 | |||
97 | if ( SDA ) byte |= i; | ||
98 | |||
99 | SCL_LO; | ||
100 | DELAY; | ||
101 | } | ||
102 | |||
103 | i2c_ack(ack); | ||
104 | return byte; | ||
105 | } | ||
106 | |||
107 | void i2c_ack(int bit) | ||
108 | { | ||
109 | SDA_OUTPUT; | ||
110 | |||
111 | if (bit) | ||
112 | SDA_HI; | ||
113 | else | ||
114 | SDA_LO; | ||
115 | |||
116 | SCL_HI; | ||
117 | DELAY; | ||
118 | SCL_LO; | ||
119 | DELAY; | ||
120 | } | ||
121 | |||
122 | int i2c_getack(void) | ||
123 | { | ||
124 | bool ack_bit; | ||
125 | |||
126 | SDA_INPUT; | ||
127 | |||
128 | SCL_HI; | ||
129 | DELAY; | ||
130 | |||
131 | ack_bit = SDA; | ||
132 | DELAY; | ||
133 | |||
134 | SCL_LO; | ||
135 | DELAY; | ||
136 | |||
137 | return ack_bit; | ||
138 | } | ||
139 | |||
140 | /* device = 8 bit slave address */ | ||
141 | int i2c_write(int device, unsigned char* buf, int count ) | ||
142 | { | ||
143 | int i = 0; | ||
144 | mutex_lock(&i2c_mtx); | ||
145 | |||
146 | i2c_start(); | ||
147 | i2c_outb(device & 0xfe); | ||
148 | |||
149 | while (!i2c_getack() && i < count) | ||
150 | { | ||
151 | i2c_outb(buf[i++]); | ||
152 | } | ||
153 | |||
154 | i2c_stop(); | ||
155 | mutex_unlock(&i2c_mtx); | ||
156 | return 0; | ||
157 | } | ||
158 | |||
159 | |||
160 | /* device = 8 bit slave address */ | ||
161 | int i2c_readmem(int device, int address, unsigned char* buf, int count ) | ||
162 | { | ||
163 | int i = 0; | ||
164 | mutex_lock(&i2c_mtx); | ||
165 | |||
166 | i2c_start(); | ||
167 | i2c_outb(device & 0xfe); | ||
168 | if (i2c_getack()) goto exit; | ||
169 | |||
170 | i2c_outb(address); | ||
171 | if (i2c_getack()) goto exit; | ||
172 | |||
173 | i2c_start(); | ||
174 | i2c_outb(device | 1); | ||
175 | if (i2c_getack()) goto exit; | ||
176 | |||
177 | while (i < count) | ||
178 | { | ||
179 | buf[i] = i2c_inb(i == (count-1)); | ||
180 | i++; | ||
181 | } | ||
182 | |||
183 | exit: | ||
184 | i2c_stop(); | ||
185 | mutex_unlock(&i2c_mtx); | ||
186 | return 0; | ||
187 | } | ||