reduce i2c delays

bigdinotech · calvinatintel · commit 868214917755 · 2016-06-29T17:46:13.000-07:00
-reduce i2c delays to increase performace without changing the timeout
threshold
diff --git a/cores/arduino/i2c.c b/cores/arduino/i2c.c
@@ -49,7 +49,7 @@ static void ss_i2c_err(uint32_t dev_id)
 }
 
 static int wait_rx_or_err(bool no_stop){
-	uint64_t timeout = TIMEOUT_MS;
+	uint64_t timeout = TIMEOUT_MS * 20;
 	while(timeout--) {
 		if (i2c_err_detect) {
 			if (i2c_err_source & I2C_ABRT_7B_ADDR_NOACK )
@@ -70,7 +70,7 @@ static int wait_rx_or_err(bool no_stop){
 				return I2C_OK;
 			}
 		}
-		delay(1);
+		delayMicroseconds(50);
 	}
 	if (!no_stop)
 		return I2C_TIMEOUT;
@@ -79,7 +79,7 @@ static int wait_rx_or_err(bool no_stop){
 }
 
 static int wait_tx_or_err(bool no_stop){
-	uint64_t timeout = TIMEOUT_MS;
+	uint64_t timeout = TIMEOUT_MS * 20;
 	while(timeout--) {
 		if (i2c_err_detect) {
 			if (i2c_err_source & I2C_ABRT_7B_ADDR_NOACK )
@@ -100,7 +100,7 @@ static int wait_tx_or_err(bool no_stop){
 			return I2C_OK;
 			}
 		}
-		delay(1);
+		delayMicroseconds(50);
 	}
 	if (!no_stop)
 		return I2C_TIMEOUT;
@@ -109,15 +109,15 @@ static int wait_tx_or_err(bool no_stop){
 }
 
 static int wait_dev_ready(I2C_CONTROLLER controller_id, bool no_stop){
-	uint64_t timeout = TIMEOUT_MS;
+	uint64_t timeout = TIMEOUT_MS * 20;
 	int ret = 0;
 	while(timeout--) {
 		ret = ss_i2c_status(controller_id, no_stop);
 		if (ret == I2C_OK) {
 			return I2C_OK;
 		}
 		if (ret == I2C_BUSY) {
-			delay(1);
+			delayMicroseconds(50);
 		}
 	}
 	return I2C_TIMEOUT - ret;

Original file line number	Diff line number	Diff line change
`@@ -49,7 +49,7 @@ static void ss_i2c_err(uint32_t dev_id)`
`49`	`49`	`}`
`50`	`50`
`51`	`51`	`static int wait_rx_or_err(bool no_stop){`
`52`		`- uint64_t timeout = TIMEOUT_MS;`
	`52`	`+ uint64_t timeout = TIMEOUT_MS * 20;`
`53`	`53`	`while(timeout--) {`
`54`	`54`	`if (i2c_err_detect) {`
`55`	`55`	`if (i2c_err_source & I2C_ABRT_7B_ADDR_NOACK )`
`@@ -70,7 +70,7 @@ static int wait_rx_or_err(bool no_stop){`
`70`	`70`	`return I2C_OK;`
`71`	`71`	`}`
`72`	`72`	`}`
`73`		`- delay(1);`
	`73`	`+ delayMicroseconds(50);`
`74`	`74`	`}`
`75`	`75`	`if (!no_stop)`
`76`	`76`	`return I2C_TIMEOUT;`
`@@ -79,7 +79,7 @@ static int wait_rx_or_err(bool no_stop){`
`79`	`79`	`}`
`80`	`80`
`81`	`81`	`static int wait_tx_or_err(bool no_stop){`
`82`		`- uint64_t timeout = TIMEOUT_MS;`
	`82`	`+ uint64_t timeout = TIMEOUT_MS * 20;`
`83`	`83`	`while(timeout--) {`
`84`	`84`	`if (i2c_err_detect) {`
`85`	`85`	`if (i2c_err_source & I2C_ABRT_7B_ADDR_NOACK )`
`@@ -100,7 +100,7 @@ static int wait_tx_or_err(bool no_stop){`
`100`	`100`	`return I2C_OK;`
`101`	`101`	`}`
`102`	`102`	`}`
`103`		`- delay(1);`
	`103`	`+ delayMicroseconds(50);`
`104`	`104`	`}`
`105`	`105`	`if (!no_stop)`
`106`	`106`	`return I2C_TIMEOUT;`
`@@ -109,15 +109,15 @@ static int wait_tx_or_err(bool no_stop){`
`109`	`109`	`}`
`110`	`110`
`111`	`111`	`static int wait_dev_ready(I2C_CONTROLLER controller_id, bool no_stop){`
`112`		`- uint64_t timeout = TIMEOUT_MS;`
	`112`	`+ uint64_t timeout = TIMEOUT_MS * 20;`
`113`	`113`	`int ret = 0;`
`114`	`114`	`while(timeout--) {`
`115`	`115`	`ret = ss_i2c_status(controller_id, no_stop);`
`116`	`116`	`if (ret == I2C_OK) {`
`117`	`117`	`return I2C_OK;`
`118`	`118`	`}`
`119`	`119`	`if (ret == I2C_BUSY) {`
`120`		`- delay(1);`
	`120`	`+ delayMicroseconds(50);`
`121`	`121`	`}`
`122`	`122`	`}`
`123`	`123`	`return I2C_TIMEOUT - ret;`