add information about session timeouts to readme

[rsbs2] / bmc / i2c.c

diff --git a/bmc/i2c.c b/bmc/i2c.c
index f081991ad34c5c1b5a449b147fc527afe77af976..07d2e7902a4e5a6858a550dd7c423baf450f5b6f 100644 (file)
--- a/bmc/i2c.c
+++ b/bmc/i2c.c
@@ -3,6 +3,7 @@
 #include <stdio.h>
 #include "i2c.h"
 #include "bmc.h"
+#include "config.h"
 #include "ipmb.h"
 
 #define TWCR_ACK TWCR = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(1<<TWEA)|(0<<TWSTA)|(0<<TWSTO)|(0<<TWWC);  
@@ -14,14 +15,24 @@ volatile uint8_t i2c_len = 0x00;
 static volatile uint8_t i2c_pos = 0x00;
 volatile uint8_t i2c_done = 0x00;
 
+#define I2C_FREQ 20000UL
+
 void i2c_init()
 {
-       TWBR = 0xff;
+       /* SCLf = F_CPU / (16 + 2 * TWBR * 4^TWPS)
+        * TWPS is 0 =>
+        * TWBR = (F_CPU/(2 * SCL)) - 8
+        */
+       TWBR = (F_CPU/(2*I2C_FREQ))-8;
        TWAR = BMC_ADDR & 0xfe;
        TWDR = 0x00;
        TWCR &= ~((1<<TWSTA) | (1<<TWSTO));
        TWCR |= ((1<<TWEA) | (1<<TWEN) | (1<<TWIE)); 
+#ifdef __AVR_ATmega16__
        PORTC = 0x03;
+#else
+#error "Don't know how to set pullups for this chip, please add support"
+#endif
 }
 
 void i2c_send(unsigned char *buf, int len)
@@ -35,36 +46,48 @@ void i2c_send(unsigned char *buf, int len)
        TWCR = ((1<<TWINT) | (1<<TWSTA) | (1<<TWEN)); /* Send start */
 
        while(!(TWCR & (1<<TWINT))) {}
-       if ((TW_STATUS & 0xf8) != TW_START)
+       if (TW_STATUS != TW_START) {
+#ifdef DEBUG
+               printf("I2C: error sending START\n");
+#endif
                goto out;
+       }
 
        TWDR = buf[0]; /* SLA_W */
        TWCR = ((1<<TWINT) | (1<<TWEN));
 
        while(!(TWCR & (1<<TWINT))) {}
-       if ((TW_STATUS & 0xf8) != TW_MT_SLA_ACK)
-               goto out;
+       if (TW_STATUS != TW_MT_SLA_ACK) {
+#ifdef DEBUG
+               printf("I2C: error sending SLA_W\n");
+#endif
+               goto out2;
+       }
        
        for(i = 1; i < len; i++) {
                TWDR = buf[i]; /* Send Data */
                TWCR = ((1<<TWINT) | (1<<TWEN));
 
                while(!(TWCR & (1<<TWINT))) {}
-               if ((TW_STATUS & 0xf8) != TW_MT_DATA_ACK)
-                       goto out;
+               if (TW_STATUS != TW_MT_DATA_ACK) {
+#ifdef DEBUG
+                       printf("I2C: error sending DATA byte %d\n", i);
+#endif
+                       goto out2;
+               }
        }
 
-       TWCR = ((1<<TWINT) | (1<<TWEN) | (1<<TWSTO));
-       while(TWCR & (1<<TWSTO)) {}
-
 #ifdef DEBUG
        printf("I2C Data sent\n");
 #endif
 
+out2:
+       TWCR = ((1<<TWINT) | (1<<TWEN) | (1<<TWSTO));
+       while(TWCR & (1<<TWSTO)) {}
+
 out:   
-       TWDR = 0x00;
-       TWCR = old_TWCR;
        SREG = old_SREG;
+       TWCR = old_TWCR | (1<<TWINT);
 }
 
 ISR (TWI_vect, ISR_BLOCK)
@@ -87,6 +110,11 @@ ISR (TWI_vect, ISR_BLOCK)
 #ifdef DEBUG
                        printf("I2C: Data received: 0x%02x\n", TWDR);
 #endif
+                       if (i2c_pos >= sizeof(i2c_databuf)) {
+                               TWCR_RESET;
+                               i2c_pos = 0x00;
+                               break;
+                       }
                        i2c_databuf[i2c_pos] = TWDR;
                        i2c_pos++;
                        TWCR_ACK;
@@ -102,6 +130,13 @@ ISR (TWI_vect, ISR_BLOCK)
                        TWCR_RESET;
                        break;
 
+               case TW_NO_INFO:
+#ifdef DEBUG
+                       printf("I2C: TW_NO_INFO received status 0x%2x\n", TW_STATUS);
+#endif
+                       TWCR |= (1<<TWINT);
+                       break;
+
                default:
 #ifdef DEBUG
                        printf("I2C: Unimplemented status 0x%02x\n", TW_STATUS);