altos: Make stdio 8-bit clean by making pollchar return int

We were stealing one value (0xff) in the return value from pollchar to
indicate 'not ready yet'. Instead of doing that, use the integer value
-1 and have pollchar return an int instead of a char. That
necessitated cleaning a few other bits to make sure that 0xff wouldn't
get promoted to -1 on accident.

Signed-off-by: Keith Packard <keithp@keithp.com>

5 files changed, 32 insertions, 8 deletions

diff --git a/src/core/ao.h b/src/core/ao.h
index 1aff3d49..54018b37 100644
--- a/src/core/ao.h
+++ b/src/core/ao.h
@@ -599,10 +599,10 @@ ao_monitor_init(void) __reentrant;
  * ao_stdio.c
  */
 
-#define AO_READ_AGAIN	((char) -1)
+#define AO_READ_AGAIN	(-1)
 
 struct ao_stdio {
-	char	(*pollchar)(void);
+	int	(*pollchar)(void);
 	void	(*putchar)(char c) __reentrant;
 	void	(*flush)(void);
 	uint8_t	echo;
@@ -621,7 +621,7 @@ uint8_t
 ao_echo(void);
 
 int8_t
-ao_add_stdio(char (*pollchar)(void),
+ao_add_stdio(int (*pollchar)(void),
 	     void (*putchar)(char) __reentrant,
 	     void (*flush)(void)) __reentrant;
 
diff --git a/src/core/ao_packet.h b/src/core/ao_packet.h
index 0eafd3b2..08b184d6 100644
--- a/src/core/ao_packet.h
+++ b/src/core/ao_packet.h
@@ -62,7 +62,7 @@ ao_packet_flush(void);
 void
 ao_packet_putchar(char c) __reentrant;
 
-char
+int
 ao_packet_pollchar(void);
 
 #if PACKET_HAS_MASTER
diff --git a/src/core/ao_serial.h b/src/core/ao_serial.h
index 53aa8a89..a799bf2c 100644
--- a/src/core/ao_serial.h
+++ b/src/core/ao_serial.h
@@ -22,6 +22,7 @@
 #define AO_SERIAL_SPEED_9600	1
 #define AO_SERIAL_SPEED_19200	2
 #define AO_SERIAL_SPEED_57600	3
+#define AO_SERIAL_SPEED_115200	4
 
 #if HAS_SERIAL_0
 extern volatile __xdata struct ao_fifo	ao_serial0_rx_fifo;
@@ -30,6 +31,9 @@ extern volatile __xdata struct ao_fifo	ao_serial0_tx_fifo;
 char
 ao_serial0_getchar(void);
 
+int
+ao_serial0_pollchar(void);
+
 void
 ao_serial0_putchar(char c);
 
@@ -47,7 +51,7 @@ extern volatile __xdata struct ao_fifo	ao_serial1_tx_fifo;
 char
 ao_serial1_getchar(void);
 
-char
+int
 ao_serial1_pollchar(void);
 
 void
@@ -67,7 +71,7 @@ extern volatile __xdata struct ao_fifo	ao_serial2_tx_fifo;
 char
 ao_serial2_getchar(void);
 
-char
+int
 ao_serial2_pollchar(void);
 
 void
@@ -80,6 +84,26 @@ void
 ao_serial2_set_speed(uint8_t speed);
 #endif
 
+#if HAS_SERIAL_3
+extern volatile __xdata struct ao_fifo	ao_serial3_rx_fifo;
+extern volatile __xdata struct ao_fifo	ao_serial3_tx_fifo;
+
+char
+ao_serial3_getchar(void);
+
+int
+ao_serial3_pollchar(void);
+
+void
+ao_serial3_putchar(char c);
+
+void
+ao_serial3_drain(void);
+
+void
+ao_serial3_set_speed(uint8_t speed);
+#endif
+
 void
 ao_serial_init(void);
 
diff --git a/src/core/ao_stdio.c b/src/core/ao_stdio.c
index 8cf66a23..4a832487 100644
--- a/src/core/ao_stdio.c
+++ b/src/core/ao_stdio.c
@@ -123,7 +123,7 @@ ao_echo(void)
 }
 
 int8_t
-ao_add_stdio(char (*pollchar)(void),
+ao_add_stdio(int (*pollchar)(void),
 	     void (*putchar)(char),
 	     void (*flush)(void)) __reentrant
 {
diff --git a/src/core/ao_usb.h b/src/core/ao_usb.h
index e051db93..4476ee6b 100644
--- a/src/core/ao_usb.h
+++ b/src/core/ao_usb.h
@@ -33,7 +33,7 @@ ao_usb_getchar(void);
 /* Poll for a charcter on the USB input queue.
  * returns AO_READ_AGAIN if none are available
  */
-char
+int
 ao_usb_pollchar(void);
 
 /* Flush the USB output queue */