msp430fr spi: Use 16-bit lengths

include/arch/msp430fr5969lp/driver/spi.h

@@ -14,8 +14,8 @@ class SPI {
 		SPI () {}
 		void setup();
 		signed char xmit(
-				unsigned char tx_len, unsigned char *tx_buf,
-				unsigned char rx_len, unsigned char *rx_buf);
+				unsigned int tx_len, unsigned char *tx_buf,
+				unsigned int rx_len, unsigned char *rx_buf);
 };
 
 extern SPI spi;

include/arch/msp430fr5994lp/driver/spi.h

@@ -14,8 +14,8 @@ class SPI {
 		SPI () {}
 		void setup();
 		signed char xmit(
-				unsigned char tx_len, unsigned char *tx_buf,
-				unsigned char rx_len, unsigned char *rx_buf);
+				unsigned int tx_len, unsigned char *tx_buf,
+				unsigned int rx_len, unsigned char *rx_buf);
 };
 
 extern SPI spi;

src/arch/msp430fr5969lp/driver/spi.cc

@@ -41,8 +41,8 @@ static inline unsigned char clean_rxbuf()
 	return UCB0RXBUF;
 }
 
-signed char SPI::xmit(unsigned char tx_len, unsigned char *tx_buf,
-		unsigned char rx_len, unsigned char *rx_buf)
+signed char SPI::xmit(unsigned int tx_len, unsigned char *tx_buf,
+		unsigned int rx_len, unsigned char *rx_buf)
 {
 	if (tx_len < 1) {
 		return -1;

src/arch/msp430fr5994lp/driver/spi.cc

@@ -41,8 +41,8 @@ static inline unsigned char clean_rxbuf()
 	return UCB1RXBUF;
 }
 
-signed char SPI::xmit(unsigned char tx_len, unsigned char *tx_buf,
-		unsigned char rx_len, unsigned char *rx_buf)
+signed char SPI::xmit(unsigned int tx_len, unsigned char *tx_buf,
+		unsigned int rx_len, unsigned char *rx_buf)
 {
 	if (tx_len < 1) {
 		return -1;