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Commit | Line | Data |
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99e4226b MG |
1 | #include <util/twi.h> |
2 | #include <avr/interrupt.h> | |
3 | #include <stdio.h> | |
4 | #include "i2c.h" | |
da7751cb | 5 | #include "bmc.h" |
d5193055 | 6 | #include "ipmb.h" |
99e4226b MG |
7 | |
8 | #define TWCR_ACK TWCR = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(1<<TWEA)|(0<<TWSTA)|(0<<TWSTO)|(0<<TWWC); | |
9 | #define TWCR_NACK TWCR = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(0<<TWEA)|(0<<TWSTA)|(0<<TWSTO)|(0<<TWWC); | |
10 | #define TWCR_RESET TWCR = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(1<<TWEA)|(0<<TWSTA)|(1<<TWSTO)|(0<<TWWC); | |
11 | ||
45320371 | 12 | volatile unsigned char i2c_databuf[24]; |
da7751cb MG |
13 | volatile uint8_t i2c_len = 0x00; |
14 | static volatile uint8_t i2c_pos = 0x00; | |
15 | volatile uint8_t i2c_done = 0x00; | |
77ad1a84 | 16 | |
989281f2 MG |
17 | #define I2C_FREQ 20000UL |
18 | ||
99e4226b MG |
19 | void i2c_init() |
20 | { | |
989281f2 MG |
21 | /* SCLf = F_CPU / (16 + 2 * TWBR * 4^TWPS) |
22 | * TWPS is 0 => | |
23 | * TWBR = (F_CPU/(2 * SCL)) - 8 | |
24 | */ | |
25 | TWBR = (F_CPU/(2*I2C_FREQ))-8; | |
7f52e040 MG |
26 | TWAR = BMC_ADDR & 0xfe; |
27 | TWDR = 0x00; | |
28 | TWCR &= ~((1<<TWSTA) | (1<<TWSTO)); | |
29 | TWCR |= ((1<<TWEA) | (1<<TWEN) | (1<<TWIE)); | |
e641fce6 | 30 | #ifdef __AVR_ATmega16__ |
7f52e040 | 31 | PORTC = 0x03; |
e641fce6 MG |
32 | #else |
33 | #error "Don't know how to set pullups for this chip, please add support" | |
34 | #endif | |
99e4226b MG |
35 | } |
36 | ||
d5193055 MG |
37 | void i2c_send(unsigned char *buf, int len) |
38 | { | |
39 | uint8_t old_TWCR = TWCR; | |
40 | uint8_t old_SREG = SREG; | |
41 | int i; | |
42 | ||
43 | cli(); | |
44 | ||
45 | TWCR = ((1<<TWINT) | (1<<TWSTA) | (1<<TWEN)); /* Send start */ | |
46 | ||
47 | while(!(TWCR & (1<<TWINT))) {} | |
87f4338b MG |
48 | if (TW_STATUS != TW_START) { |
49 | #ifdef DEBUG | |
50 | printf("I2C: error sending START\n"); | |
51 | #endif | |
d5193055 | 52 | goto out; |
87f4338b | 53 | } |
d5193055 MG |
54 | |
55 | TWDR = buf[0]; /* SLA_W */ | |
56 | TWCR = ((1<<TWINT) | (1<<TWEN)); | |
57 | ||
58 | while(!(TWCR & (1<<TWINT))) {} | |
87f4338b MG |
59 | if (TW_STATUS != TW_MT_SLA_ACK) { |
60 | #ifdef DEBUG | |
61 | printf("I2C: error sending SLA_W\n"); | |
62 | #endif | |
63 | goto out2; | |
64 | } | |
d5193055 MG |
65 | |
66 | for(i = 1; i < len; i++) { | |
67 | TWDR = buf[i]; /* Send Data */ | |
68 | TWCR = ((1<<TWINT) | (1<<TWEN)); | |
69 | ||
70 | while(!(TWCR & (1<<TWINT))) {} | |
87f4338b MG |
71 | if (TW_STATUS != TW_MT_DATA_ACK) { |
72 | #ifdef DEBUG | |
73 | printf("I2C: error sending DATA byte %d\n", i); | |
74 | #endif | |
75 | goto out2; | |
76 | } | |
d5193055 MG |
77 | } |
78 | ||
27f7ea19 | 79 | #ifdef DEBUG |
da7751cb MG |
80 | printf("I2C Data sent\n"); |
81 | #endif | |
d5193055 | 82 | |
87f4338b MG |
83 | out2: |
84 | TWCR = ((1<<TWINT) | (1<<TWEN) | (1<<TWSTO)); | |
85 | while(TWCR & (1<<TWSTO)) {} | |
86 | ||
d5193055 | 87 | out: |
d5193055 | 88 | SREG = old_SREG; |
285b23e4 | 89 | TWCR = old_TWCR | (1<<TWINT); |
d5193055 MG |
90 | } |
91 | ||
7f52e040 | 92 | ISR (TWI_vect, ISR_BLOCK) |
99e4226b | 93 | { |
da7751cb MG |
94 | if (i2c_done) |
95 | TWCR_RESET; | |
96 | ||
87f4338b | 97 | switch (TW_STATUS) { |
77ad1a84 MG |
98 | case TW_SR_SLA_ACK: |
99 | #ifdef DEBUG | |
100 | printf("I2C: Slave 0x%02x adressed\n", TWDR); | |
101 | #endif | |
da7751cb MG |
102 | i2c_pos = 0x00; |
103 | i2c_databuf[i2c_pos] = TWDR; | |
104 | i2c_pos++; | |
77ad1a84 MG |
105 | TWCR_ACK; |
106 | break; | |
107 | ||
108 | case TW_SR_DATA_ACK: | |
109 | #ifdef DEBUG | |
110 | printf("I2C: Data received: 0x%02x\n", TWDR); | |
111 | #endif | |
a44532dc MG |
112 | if (i2c_pos >= sizeof(i2c_databuf)) { |
113 | TWCR_RESET; | |
114 | i2c_pos = 0x00; | |
115 | break; | |
116 | } | |
da7751cb MG |
117 | i2c_databuf[i2c_pos] = TWDR; |
118 | i2c_pos++; | |
77ad1a84 MG |
119 | TWCR_ACK; |
120 | break; | |
121 | ||
122 | case TW_SR_STOP: | |
123 | #ifdef DEBUG | |
124 | printf("I2C: STOP received\n"); | |
125 | #endif | |
da7751cb MG |
126 | i2c_len = i2c_pos; |
127 | i2c_pos = 0x00; | |
128 | i2c_done = 0x01; | |
77ad1a84 MG |
129 | TWCR_RESET; |
130 | break; | |
131 | ||
87f4338b MG |
132 | case TW_NO_INFO: |
133 | #ifdef DEBUG | |
134 | printf("I2C: TW_NO_INFO received status 0x%2x\n", TW_STATUS); | |
135 | #endif | |
136 | TWCR |= (1<<TWINT); | |
137 | break; | |
138 | ||
77ad1a84 | 139 | default: |
f9d5c6e0 | 140 | #ifdef DEBUG |
87f4338b | 141 | printf("I2C: Unimplemented status 0x%02x\n", TW_STATUS); |
f9d5c6e0 | 142 | #endif |
77ad1a84 MG |
143 | TWCR_RESET; |
144 | break; | |
99e4226b MG |
145 | } |
146 | } |