diff options
Diffstat (limited to 'firmware/target/coldfire/iriver/h100')
-rw-r--r-- | firmware/target/coldfire/iriver/h100/sw_i2c-h100.c | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/firmware/target/coldfire/iriver/h100/sw_i2c-h100.c b/firmware/target/coldfire/iriver/h100/sw_i2c-h100.c new file mode 100644 index 0000000000..cb061875e0 --- /dev/null +++ b/firmware/target/coldfire/iriver/h100/sw_i2c-h100.c | |||
@@ -0,0 +1,259 @@ | |||
1 | /*************************************************************************** | ||
2 | * __________ __ ___. | ||
3 | * Open \______ \ ____ ____ | | _\_ |__ _______ ___ | ||
4 | * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / | ||
5 | * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < | ||
6 | * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ | ||
7 | * \/ \/ \/ \/ \/ | ||
8 | * $Id$ | ||
9 | * | ||
10 | * Copyright (C) 2006 by Miika Pekkarinen | ||
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 "system.h" | ||
20 | #include "logf.h" | ||
21 | #include "inttypes.h" | ||
22 | |||
23 | #include "sw_i2c.h" | ||
24 | |||
25 | /** | ||
26 | * I2C-functions are copied and ported from fmradio.c. | ||
27 | * later fixed, adapted and moved to a seperate file so they can be re-used by the rtc-ds1339c code by Robert Kukla | ||
28 | */ | ||
29 | |||
30 | /* cute little functions, atomic read-modify-write */ | ||
31 | |||
32 | /* SCL is GPIO, 12 */ | ||
33 | #define SCL ( 0x00001000 & GPIO_READ) | ||
34 | #define SCL_OUT_LO and_l(~0x00001000, &GPIO_OUT) | ||
35 | #define SCL_LO or_l( 0x00001000, &GPIO_ENABLE) | ||
36 | #define SCL_HI and_l(~0x00001000, &GPIO_ENABLE) | ||
37 | |||
38 | /* SDA is GPIO1, 13 */ | ||
39 | #define SDA ( 0x00002000 & GPIO1_READ) | ||
40 | #define SDA_OUT_LO and_l(~0x00002000, &GPIO1_OUT) | ||
41 | #define SDA_LO or_l( 0x00002000, &GPIO1_ENABLE) | ||
42 | #define SDA_HI and_l(~0x00002000, &GPIO1_ENABLE) | ||
43 | |||
44 | /* delay loop to achieve 400kHz at 120MHz CPU frequency */ | ||
45 | #define DELAY do { int _x; for(_x=0;_x<22;_x++);} while(0) | ||
46 | |||
47 | void sw_i2c_init(void) | ||
48 | { | ||
49 | or_l(0x00001000, &GPIO_FUNCTION); | ||
50 | or_l(0x00002000, &GPIO1_FUNCTION); | ||
51 | SDA_HI; | ||
52 | SCL_HI; | ||
53 | SDA_OUT_LO; | ||
54 | SCL_OUT_LO; | ||
55 | } | ||
56 | |||
57 | /* in: C=? D=? | ||
58 | * out: C=L D=L | ||
59 | */ | ||
60 | static void sw_i2c_start(void) | ||
61 | { | ||
62 | SCL_LO; | ||
63 | DELAY; | ||
64 | SDA_HI; | ||
65 | DELAY; | ||
66 | SCL_HI; | ||
67 | DELAY; | ||
68 | SDA_LO; | ||
69 | DELAY; | ||
70 | SCL_LO; | ||
71 | } | ||
72 | |||
73 | /* in: C=L D=? | ||
74 | * out: C=H D=H | ||
75 | */ | ||
76 | static void sw_i2c_stop(void) | ||
77 | { | ||
78 | SDA_LO; | ||
79 | DELAY; | ||
80 | SCL_HI; | ||
81 | DELAY; | ||
82 | SDA_HI; | ||
83 | } | ||
84 | |||
85 | /* in: C=L D=H | ||
86 | * out: C=L D=L | ||
87 | */ | ||
88 | static void sw_i2c_ack(void) | ||
89 | { | ||
90 | SDA_LO; | ||
91 | DELAY; | ||
92 | |||
93 | SCL_HI; | ||
94 | DELAY; | ||
95 | SCL_LO; | ||
96 | } | ||
97 | |||
98 | /* in: C=L D=H | ||
99 | * out: C=L D=H | ||
100 | */ | ||
101 | static void sw_i2c_nack(void) | ||
102 | { | ||
103 | SDA_HI; /* redundant */ | ||
104 | DELAY; | ||
105 | |||
106 | SCL_HI; | ||
107 | DELAY; | ||
108 | SCL_LO; | ||
109 | } | ||
110 | |||
111 | /* in: C=L D=? | ||
112 | * out: C=L D=H | ||
113 | */ | ||
114 | static bool sw_i2c_getack(void) | ||
115 | { | ||
116 | bool ret = true; | ||
117 | /* int count = 10; */ | ||
118 | |||
119 | SDA_HI; /* sets to input */ | ||
120 | DELAY; | ||
121 | SCL_HI; | ||
122 | DELAY; | ||
123 | |||
124 | /* while (SDA && count--) */ | ||
125 | /* DELAY; */ | ||
126 | |||
127 | if (SDA) | ||
128 | /* ack failed */ | ||
129 | ret = false; | ||
130 | |||
131 | SCL_LO; | ||
132 | |||
133 | return ret; | ||
134 | } | ||
135 | |||
136 | /* in: C=L D=? | ||
137 | * out: C=L D=? | ||
138 | */ | ||
139 | static void sw_i2c_outb(unsigned char byte) | ||
140 | { | ||
141 | int i; | ||
142 | |||
143 | /* clock out each bit, MSB first */ | ||
144 | for ( i=0x80; i; i>>=1 ) | ||
145 | { | ||
146 | if ( i & byte ) | ||
147 | SDA_HI; | ||
148 | else | ||
149 | SDA_LO; | ||
150 | DELAY; | ||
151 | |||
152 | SCL_HI; | ||
153 | DELAY; | ||
154 | SCL_LO; | ||
155 | } | ||
156 | } | ||
157 | |||
158 | /* in: C=L D=? | ||
159 | * out: C=L D=H | ||
160 | */ | ||
161 | static unsigned char sw_i2c_inb(void) | ||
162 | { | ||
163 | int i; | ||
164 | unsigned char byte = 0; | ||
165 | |||
166 | SDA_HI; /* sets to input */ | ||
167 | |||
168 | /* clock in each bit, MSB first */ | ||
169 | for ( i=0x80; i; i>>=1 ) | ||
170 | { | ||
171 | DELAY; | ||
172 | do { | ||
173 | SCL_HI; | ||
174 | DELAY; | ||
175 | } | ||
176 | while(SCL==0); /* wait for any SCL clock stretching */ | ||
177 | if ( SDA ) | ||
178 | byte |= i; | ||
179 | SCL_LO; | ||
180 | } | ||
181 | |||
182 | return byte; | ||
183 | } | ||
184 | |||
185 | int sw_i2c_write(unsigned char chip, unsigned char location, const unsigned char* buf, int count) | ||
186 | { | ||
187 | int i; | ||
188 | |||
189 | sw_i2c_start(); | ||
190 | sw_i2c_outb((chip & 0xfe) | SW_I2C_WRITE); | ||
191 | if (!sw_i2c_getack()) | ||
192 | { | ||
193 | sw_i2c_stop(); | ||
194 | return -1; | ||
195 | } | ||
196 | |||
197 | sw_i2c_outb(location); | ||
198 | if (!sw_i2c_getack()) | ||
199 | { | ||
200 | sw_i2c_stop(); | ||
201 | return -2; | ||
202 | } | ||
203 | |||
204 | for (i=0; i<count; i++) | ||
205 | { | ||
206 | sw_i2c_outb(buf[i]); | ||
207 | if (!sw_i2c_getack()) | ||
208 | { | ||
209 | sw_i2c_stop(); | ||
210 | return -3; | ||
211 | } | ||
212 | } | ||
213 | |||
214 | sw_i2c_stop(); | ||
215 | |||
216 | return 0; | ||
217 | } | ||
218 | |||
219 | int sw_i2c_read(unsigned char chip, unsigned char location, unsigned char* buf, int count) | ||
220 | { | ||
221 | int i; | ||
222 | |||
223 | sw_i2c_start(); | ||
224 | sw_i2c_outb((chip & 0xfe) | SW_I2C_WRITE); | ||
225 | if (!sw_i2c_getack()) | ||
226 | { | ||
227 | sw_i2c_stop(); | ||
228 | return -1; | ||
229 | } | ||
230 | |||
231 | sw_i2c_outb(location); | ||
232 | if (!sw_i2c_getack()) | ||
233 | { | ||
234 | sw_i2c_stop(); | ||
235 | return -2; | ||
236 | } | ||
237 | |||
238 | sw_i2c_start(); | ||
239 | sw_i2c_outb((chip & 0xfe) | SW_I2C_READ); | ||
240 | if (!sw_i2c_getack()) | ||
241 | { | ||
242 | sw_i2c_stop(); | ||
243 | return -3; | ||
244 | } | ||
245 | |||
246 | for (i=0; i<count-1; i++) | ||
247 | { | ||
248 | buf[i] = sw_i2c_inb(); | ||
249 | sw_i2c_ack(); | ||
250 | } | ||
251 | |||
252 | /* 1byte min */ | ||
253 | buf[i] = sw_i2c_inb(); | ||
254 | sw_i2c_nack(); | ||
255 | |||
256 | sw_i2c_stop(); | ||
257 | |||
258 | return 0; | ||
259 | } | ||