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dummy for platform event messages, so rsbs2 doesn't wait for timeout
[rsbs2] / bmc / i2c.c
CommitLineData
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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"
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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 12volatile unsigned char i2c_databuf[24];
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13volatile uint8_t i2c_len = 0x00;
14static volatile uint8_t i2c_pos = 0x00;
15volatile uint8_t i2c_done = 0x00;
77ad1a84 16
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17void i2c_init()
18{
da7751cb 19 TWBR = 0xff;
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20 TWAR = BMC_ADDR & 0xfe;
21 TWDR = 0x00;
22 TWCR &= ~((1<<TWSTA) | (1<<TWSTO));
23 TWCR |= ((1<<TWEA) | (1<<TWEN) | (1<<TWIE));
e641fce6 24#ifdef __AVR_ATmega16__
7f52e040 25 PORTC = 0x03;
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26#else
27#error "Don't know how to set pullups for this chip, please add support"
28#endif
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29}
30
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31void i2c_send(unsigned char *buf, int len)
32{
33 uint8_t old_TWCR = TWCR;
34 uint8_t old_SREG = SREG;
35 int i;
36
37 cli();
38
39 TWCR = ((1<<TWINT) | (1<<TWSTA) | (1<<TWEN)); /* Send start */
40
41 while(!(TWCR & (1<<TWINT))) {}
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42 if (TW_STATUS != TW_START) {
43#ifdef DEBUG
44 printf("I2C: error sending START\n");
45#endif
d5193055 46 goto out;
87f4338b 47 }
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48
49 TWDR = buf[0]; /* SLA_W */
50 TWCR = ((1<<TWINT) | (1<<TWEN));
51
52 while(!(TWCR & (1<<TWINT))) {}
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53 if (TW_STATUS != TW_MT_SLA_ACK) {
54#ifdef DEBUG
55 printf("I2C: error sending SLA_W\n");
56#endif
57 goto out2;
58 }
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59
60 for(i = 1; i < len; i++) {
61 TWDR = buf[i]; /* Send Data */
62 TWCR = ((1<<TWINT) | (1<<TWEN));
63
64 while(!(TWCR & (1<<TWINT))) {}
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65 if (TW_STATUS != TW_MT_DATA_ACK) {
66#ifdef DEBUG
67 printf("I2C: error sending DATA byte %d\n", i);
68#endif
69 goto out2;
70 }
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71 }
72
27f7ea19 73#ifdef DEBUG
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74 printf("I2C Data sent\n");
75#endif
d5193055 76
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77out2:
78 TWCR = ((1<<TWINT) | (1<<TWEN) | (1<<TWSTO));
79 while(TWCR & (1<<TWSTO)) {}
80
d5193055 81out:
d5193055 82 SREG = old_SREG;
285b23e4 83 TWCR = old_TWCR | (1<<TWINT);
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84}
85
7f52e040 86ISR (TWI_vect, ISR_BLOCK)
99e4226b 87{
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88 if (i2c_done)
89 TWCR_RESET;
90
87f4338b 91 switch (TW_STATUS) {
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92 case TW_SR_SLA_ACK:
93#ifdef DEBUG
94 printf("I2C: Slave 0x%02x adressed\n", TWDR);
95#endif
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96 i2c_pos = 0x00;
97 i2c_databuf[i2c_pos] = TWDR;
98 i2c_pos++;
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99 TWCR_ACK;
100 break;
101
102 case TW_SR_DATA_ACK:
103#ifdef DEBUG
104 printf("I2C: Data received: 0x%02x\n", TWDR);
105#endif
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106 if (i2c_pos >= sizeof(i2c_databuf)) {
107 TWCR_RESET;
108 i2c_pos = 0x00;
109 break;
110 }
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111 i2c_databuf[i2c_pos] = TWDR;
112 i2c_pos++;
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113 TWCR_ACK;
114 break;
115
116 case TW_SR_STOP:
117#ifdef DEBUG
118 printf("I2C: STOP received\n");
119#endif
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120 i2c_len = i2c_pos;
121 i2c_pos = 0x00;
122 i2c_done = 0x01;
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123 TWCR_RESET;
124 break;
125
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126 case TW_NO_INFO:
127#ifdef DEBUG
128 printf("I2C: TW_NO_INFO received status 0x%2x\n", TW_STATUS);
129#endif
130 TWCR |= (1<<TWINT);
131 break;
132
77ad1a84 133 default:
f9d5c6e0 134#ifdef DEBUG
87f4338b 135 printf("I2C: Unimplemented status 0x%02x\n", TW_STATUS);
f9d5c6e0 136#endif
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137 TWCR_RESET;
138 break;
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139 }
140}
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