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This diff has been restricted to the following files: 'i2c.c'

#
# old_revision [a2621a92a8c03a907239e78df69f38370d023a70]
# new_revision [4cc7246c1b6c809c9dc15997798f6deed15b3631]
#
# patch "i2c.c"
#  from [1d978ba6c211e6b68c567fa852d9cbefe8ebad13]
#    to [7f5362fc29f8f8f81682424c73930b5e3044c994]
#
============================================================
--- i2c.c	1d978ba6c211e6b68c567fa852d9cbefe8ebad13
+++ i2c.c	7f5362fc29f8f8f81682424c73930b5e3044c994
@@ -1,5 +1,7 @@
 
 #include "i2c.h"
+#include "interrupt.h"
+#include "event.h"
 
 #define I2CBASE  0xE001C000
 
@@ -21,35 +23,25 @@
 
 #define SI (IREG(I2CONSET) & SIFLAG)
 
+void __attribute__((interrupt("IRQ"))) i2c_interrupt_handler(void);
+
+struct i2c_transaction *i2c_transaction;
+int i2c_bytes;
+
 void init_i2c(void)
 {
 	IREG(I2CONSET) = 0x40; /* Enable I2C ready for Master Tx */
 	/* Set up for just under 400kHz */
-#if 0
+#ifdef I2C_FAST
 	IWREG(I2SCLL) = (25 * 100);
 	IWREG(I2SCLH) = (12 * 100);
 #else
-# if 0
-	IWREG(I2SCLL) = 1475; /* ~5kHz */
-	IWREG(I2SCLH) = 1475;
-# else
 	IWREG(I2SCLL) = 73; /* ~100kHz */
 	IWREG(I2SCLH) = 73;
-# endif
 #endif
+	interrupt_register(I2C0, i2c_interrupt_handler);
 }
 
-int i2cstat;
-
-int i2c_wait(void)
-{
-	int stat;
-	while (!SI);
-	stat = IREG(I2STAT);
-	i2cstat = stat;
-	return stat;
-}
-
 int i2c_conreg(void)
 {
 	return IREG(I2CONSET);
@@ -60,61 +52,113 @@ int i2c_statreg(void)
 	return IREG(I2STAT);
 }
 
-bool i2c_send_start(void)
+bool i2c_busy(void)
 {
+	return i2c_transaction != NULL;
+}
+
+bool i2c_start_transaction(struct i2c_transaction *t)
+{
+	if (i2c_transaction)
+		return FALSE;
+
+	i2c_transaction = t;
+	*(t->result) = I2C_IN_PROGRESS;
+
+	/* Paranoia in case we left things in a bad state */
 	IREG(I2CONCLR) = STOFLAG | STAFLAG;
+
+	/* Set it all going */
 	IREG(I2CONSET) = STAFLAG;
-	switch (i2c_wait()) {
-	case 0x08:
-	case 0x10:
-		return TRUE;
-	default:
-		i2c_send_stop();
-		return FALSE;
-	}
-}
 
-bool i2c_send_address(int addr, bool write)
-{
-	return i2c_send_data((addr<<1) + (write?0:1));
+	return TRUE;
 }
 
-bool i2c_send_data(unsigned int data)
+void __attribute__((interrupt("IRQ"))) i2c_interrupt_handler(void)
 {
-	IREG(I2DAT) = data;
-	IREG(I2CONCLR) = STAFLAG | STOFLAG | SIFLAG;
-	switch (i2c_wait()) {
-	case 0x18:
-	case 0x28:
-	case 0x40:
-		return TRUE;
-	default:
-		i2c_send_stop();
-		return FALSE;
+	int stat = IREG(I2STAT);
+
+	if (!i2c_transaction) {
+		IREG(I2CONSET) = STOFLAG;
+		IREG(I2CONCLR) = STAFLAG | AAFLAG | SIFLAG;
+		interrupt_clear();
+		return;
 	}
-}
 
-bool i2c_receive_data(unsigned int *data, bool last)
-{
-	if (!last)
-		IREG(I2CONSET) = AAFLAG;
-	IREG(I2CONCLR) = STAFLAG | STOFLAG | SIFLAG | (last?AAFLAG:0);
-	switch (i2c_wait()) {
-	case 0x50:
-	case 0x58:
-		*data = IREG(I2DAT);
-		return TRUE;
-	default:
-		i2c_send_stop();
-		return FALSE;
+	switch (stat) {
+
+	case 0x08: /* START transmitted */
+	case 0x10: /* repeated START transmitted */
+		IREG(I2DAT) = i2c_transaction->address;
+		IREG(I2CONCLR) = STAFLAG | STOFLAG | SIFLAG;
+		i2c_bytes = 0;
+		break;
+	case 0x18: /* SA+W transmitted, ACK received */
+	case 0x28: /* data transmitted, ACK received */
+		if (i2c_bytes < i2c_transaction->bytes) {
+			IREG(I2DAT) = i2c_transaction->data[i2c_bytes++];
+			IREG(I2CONCLR) = STAFLAG | STOFLAG | SIFLAG;
+		} else {
+			*(i2c_transaction->result) = I2C_SUCCESS;
+			if (i2c_transaction->next) {
+				i2c_transaction = i2c_transaction->next;
+				i2c_bytes = 0;
+				IREG(I2CONSET) = STAFLAG;
+				IREG(I2CONCLR) = STOFLAG | AAFLAG | SIFLAG;
+			} else {
+				i2c_transaction = NULL;
+				IREG(I2CONSET) = STOFLAG;
+				IREG(I2CONCLR) = STAFLAG | AAFLAG | SIFLAG;
+				event_set(EVENT_I2C_COMPLETE);
+			}
+		}
+		break;
+
+	case 0x50: /* data received, ACK returned */
+		i2c_transaction->data[i2c_bytes++] = IREG(I2DAT);
+		/* fall through */
+
+	case 0x40: /* SA+R transmitted, ACK received */
+		if (i2c_bytes < (i2c_transaction->bytes-1)) {
+			IREG(I2CONSET) = AAFLAG;
+			IREG(I2CONCLR) = STAFLAG | STOFLAG | SIFLAG;
+		} else {
+			IREG(I2CONCLR) = STAFLAG | STOFLAG | SIFLAG 
+							   | AAFLAG;
+		}
+		break;
+
+	case 0x58: /* data received, NACK returned */
+		i2c_transaction->data[i2c_bytes] = IREG(I2DAT);
+		*(i2c_transaction->result) = I2C_SUCCESS;
+		if (i2c_transaction->next) {
+			i2c_transaction = i2c_transaction->next;
+			i2c_bytes = 0;
+			IREG(I2CONSET) = STAFLAG;
+			IREG(I2CONCLR) = STOFLAG | AAFLAG | SIFLAG;
+		} else {
+			i2c_transaction = NULL;
+			IREG(I2CONSET) = STOFLAG;
+			IREG(I2CONCLR) = STAFLAG | AAFLAG | SIFLAG;
+			event_set(EVENT_I2C_COMPLETE);
+		}
+		break;
+
+	case 0x20: /* SA+W transmitted, NACK received */
+	case 0x30: /* data transmitted, NACK received */
+	case 0x48: /* SA+R transmitted, NACK received */
+	case 0x38: /* arbitration lost during SA+W or data */
+	case 0x00: /* bus error */
+		*(i2c_transaction->result) = I2C_FAIL;
+		i2c_transaction = NULL;
+		IREG(I2CONSET) = STOFLAG;
+		IREG(I2CONCLR) = STAFLAG | AAFLAG | SIFLAG;
+		event_set(EVENT_I2C_COMPLETE);
+		break;
+
+	/* We don't handle slave mode */
 	}
-}
 
-void i2c_send_stop(void)
-{
-	IREG(I2CONCLR) = STAFLAG | AAFLAG;
-	IREG(I2CONSET) = STOFLAG;
-	IREG(I2CONCLR) = SIFLAG;
-	/* Don't think we need to wait here. Could be wrong. */
+	interrupt_clear();
 }