| | 1 | #include <util/twi.h> |
| | 2 | #include <avr/interrupt.h> |
| | 3 | #include <stdio.h> |
| | 4 | #include "i2c.h" |
| | 5 | #include "bmc.h" |
| | 6 | #include "ipmb.h" |
| | 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 | |
| | 12 | volatile unsigned char i2c_databuf[24]; |
| | 13 | volatile uint8_t i2c_len = 0x00; |
| | 14 | static volatile uint8_t i2c_pos = 0x00; |
| | 15 | volatile uint8_t i2c_done = 0x00; |
| | 16 | |
| | 17 | void i2c_init() |
| | 18 | { |
| | 19 | TWBR = 0xff; |
| | 20 | TWAR = BMC_ADDR & 0xfe; |
| | 21 | TWDR = 0x00; |
| | 22 | TWCR &= ~((1<<TWSTA) | (1<<TWSTO)); |
| | 23 | TWCR |= ((1<<TWEA) | (1<<TWEN) | (1<<TWIE)); |
| | 24 | PORTC = 0x03; |
| | 25 | } |
| | 26 | |
| | 27 | void i2c_send(unsigned char *buf, int len) |
| | 28 | { |
| | 29 | uint8_t old_TWCR = TWCR; |
| | 30 | uint8_t old_SREG = SREG; |
| | 31 | int i; |
| | 32 | |
| | 33 | cli(); |
| | 34 | |
| | 35 | TWCR = ((1<<TWINT) | (1<<TWSTA) | (1<<TWEN)); /* Send start */ |
| | 36 | |
| | 37 | while(!(TWCR & (1<<TWINT))) {} |
| | 38 | if ((TW_STATUS & 0xf8) != TW_START) |
| | 39 | goto out; |
| | 40 | |
| | 41 | TWDR = buf[0]; /* SLA_W */ |
| | 42 | TWCR = ((1<<TWINT) | (1<<TWEN)); |
| | 43 | |
| | 44 | while(!(TWCR & (1<<TWINT))) {} |
| | 45 | if ((TW_STATUS & 0xf8) != TW_MT_SLA_ACK) |
| | 46 | goto out; |
| | 47 | |
| | 48 | for(i = 1; i < len; i++) { |
| | 49 | TWDR = buf[i]; /* Send Data */ |
| | 50 | TWCR = ((1<<TWINT) | (1<<TWEN)); |
| | 51 | |
| | 52 | while(!(TWCR & (1<<TWINT))) {} |
| | 53 | if ((TW_STATUS & 0xf8) != TW_MT_DATA_ACK) |
| | 54 | goto out; |
| | 55 | } |
| | 56 | |
| | 57 | TWCR = ((1<<TWINT) | (1<<TWEN) | (1<<TWSTO)); |
| | 58 | while(TWCR & (1<<TWSTO)) {} |
| | 59 | |
| | 60 | #ifdef DEBUG |
| | 61 | printf("I2C Data sent\n"); |
| | 62 | #endif |
| | 63 | |
| | 64 | out: |
| | 65 | TWDR = 0x00; |
| | 66 | TWCR = old_TWCR; |
| | 67 | SREG = old_SREG; |
| | 68 | } |
| | 69 | |
| | 70 | ISR (TWI_vect, ISR_BLOCK) |
| | 71 | { |
| | 72 | if (i2c_done) |
| | 73 | TWCR_RESET; |
| | 74 | |
| | 75 | switch (TW_STATUS & 0xf8) { |
| | 76 | case TW_SR_SLA_ACK: |
| | 77 | #ifdef DEBUG |
| | 78 | printf("I2C: Slave 0x%02x adressed\n", TWDR); |
| | 79 | #endif |
| | 80 | i2c_pos = 0x00; |
| | 81 | i2c_databuf[i2c_pos] = TWDR; |
| | 82 | i2c_pos++; |
| | 83 | TWCR_ACK; |
| | 84 | break; |
| | 85 | |
| | 86 | case TW_SR_DATA_ACK: |
| | 87 | #ifdef DEBUG |
| | 88 | printf("I2C: Data received: 0x%02x\n", TWDR); |
| | 89 | #endif |
| | 90 | if (i2c_pos >= sizeof(i2c_databuf)) { |
| | 91 | TWCR_RESET; |
| | 92 | i2c_pos = 0x00; |
| | 93 | break; |
| | 94 | } |
| | 95 | i2c_databuf[i2c_pos] = TWDR; |
| | 96 | i2c_pos++; |
| | 97 | TWCR_ACK; |
| | 98 | break; |
| | 99 | |
| | 100 | case TW_SR_STOP: |
| | 101 | #ifdef DEBUG |
| | 102 | printf("I2C: STOP received\n"); |
| | 103 | #endif |
| | 104 | i2c_len = i2c_pos; |
| | 105 | i2c_pos = 0x00; |
| | 106 | i2c_done = 0x01; |
| | 107 | TWCR_RESET; |
| | 108 | break; |
| | 109 | |
| | 110 | default: |
| | 111 | #ifdef DEBUG |
| | 112 | printf("I2C: Unimplemented status 0x%02x\n", (TW_STATUS & 0xf8)); |
| | 113 | #endif |
| | 114 | TWCR_RESET; |
| | 115 | break; |
| | 116 | } |
| | 117 | } |
projects / rsbs2 / blame_incremental