PERFORCE change 88426 for review

[Warner Losh]

http://perforce.freebsd.org/chv.cgi?CH=88426

Change 88426 by imp at imp_Speedy on 2005/12/19 21:35:29

	Default RCLK is the system's master clock.  Add some comments.

Affected files ...

.. //depot/projects/arm/src/sys/arm/at91/uart_dev_at91usart.c#3 edit

Differences ...

==== //depot/projects/arm/src/sys/arm/at91/uart_dev_at91usart.c#3 (text+ko) ====

@@ -43,7 +43,7 @@
 
 #include "uart_if.h"
 
-#define      DEFAULT_RCLK    3686400
+#define      DEFAULT_RCLK    AT91C_MASTER_CLOCK
 
 /*
  * Low-level UART interface.
@@ -71,9 +71,13 @@
 static int
 usart_at91rm92_probe(struct uart_bas *bas)
 {
+	/* We know that this is always here */
 	return (0);
 }
 
+/*
+ * Initialize this device (I think as the console)
+ */
 static void
 usart_at91rm92_init(struct uart_bas *bas, int baudrate, int databits, int stopbits,
     int parity)
@@ -84,12 +88,19 @@
 	uart_setreg(bas, USART_IER, USART_CSR_TXRDY | USART_CSR_RXRDY);
 }
 
+/*
+ * Free resources now that we're no longer the console.
+ */
 static void
 usart_at91rm92_term(struct uart_bas *bas)
 {
 	/* XXX */
 }
 
+/*
+ * Put a character of console output (so we do it here polling rather than
+ * interrutp driven).
+ */
 static void
 usart_at91rm92_putc(struct uart_bas *bas, int c)
 {
@@ -99,6 +110,9 @@
 	uart_setreg(bas, USART_THR, c);
 }
 
+/*
+ * Poll for a character available
+ */
 static int
 usart_at91rm92_poll(struct uart_bas *bas)
 {
@@ -108,6 +122,9 @@
 	return (uart_getreg(bas, USART_RHR) & 0xff);
 }
 
+/*
+ * Block waiting for a character.
+ */
 static int
 usart_at91rm92_getc(struct uart_bas *bas)
 {
@@ -212,5 +229,5 @@
 	usart_at91rm92_methods,
 	1,
 	.uc_range = 8,
-	.uc_rclk = 3686400
+	.uc_rclk = DEFAULT_RCLK
 };