dm: serial: Move baud rate calculation to ns16550.c

Move the function that calculates the baud rate divisor into ns16550.c so
it can be used by that file.

Signed-off-by: Simon Glass <sjg@chromium.org>

3 files changed, 34 insertions, 11 deletions

diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
index 079f67d380..3f5f4efe07 100644
--- a/drivers/serial/ns16550.c
+++ b/drivers/serial/ns16550.c
@@ -4,7 +4,7 @@
  * modified to use CONFIG_SYS_ISA_MEM and new defines
  */
 
-#include <config.h>
+#include <common.h>
 #include <ns16550.h>
 #include <watchdog.h>
 #include <linux/types.h>
@@ -45,6 +45,22 @@
 #define CONFIG_SYS_NS16550_IER  0x00
 #endif /* CONFIG_SYS_NS16550_IER */
 
+int ns16550_calc_divisor(NS16550_t port, int clock, int baudrate)
+{
+	const unsigned int mode_x_div = 16;
+
+#ifdef CONFIG_OMAP1510
+	/* If can't cleanly clock 115200 set div to 1 */
+	if ((clock == 12000000) && (baudrate == 115200)) {
+		port->osc_12m_sel = OSC_12M_SEL;  /* enable 6.5 * divisor */
+		return 1;			/* return 1 for base divisor */
+	}
+	port->osc_12m_sel = 0;			/* clear if previsouly set */
+#endif
+
+	return DIV_ROUND_CLOSEST(clock, mode_x_div * baudrate);
+}
+
 void NS16550_init(NS16550_t com_port, int baud_divisor)
 {
 #if (defined(CONFIG_SPL_BUILD) && defined(CONFIG_OMAP34XX))
diff --git a/drivers/serial/serial_ns16550.c b/drivers/serial/serial_ns16550.c
index dafeed742d..632da4cf70 100644
--- a/drivers/serial/serial_ns16550.c
+++ b/drivers/serial/serial_ns16550.c
@@ -81,7 +81,8 @@ static NS16550_t serial_ports[6] = {
 	static int  eserial##port##_init(void) \
 	{ \
 		int clock_divisor; \
-		clock_divisor = calc_divisor(serial_ports[port-1]); \
+		clock_divisor = ns16550_calc_divisor(serial_ports[port-1], \
+				CONFIG_SYS_NS16550_CLK, gd->baudrate); \
 		NS16550_init(serial_ports[port-1], clock_divisor); \
 		return 0 ; \
 	} \
@@ -118,14 +119,6 @@ static NS16550_t serial_ports[6] = {
 	.puts	= eserial##port##_puts,		\
 }
 
-static int calc_divisor (NS16550_t port)
-{
-	const unsigned int mode_x_div = 16;
-
-	return DIV_ROUND_CLOSEST(CONFIG_SYS_NS16550_CLK,
-						mode_x_div * gd->baudrate);
-}
-
 void
 _serial_putc(const char c,const int port)
 {
@@ -167,7 +160,8 @@ _serial_setbrg (const int port)
 {
 	int clock_divisor;
 
-	clock_divisor = calc_divisor(PORT);
+	clock_divisor = ns16550_calc_divisor(PORT, CONFIG_SYS_NS16550_CLK,
+					     gd->baudrate);
 	NS16550_reinit(PORT, clock_divisor);
 }
 
diff --git a/include/ns16550.h b/include/ns16550.h
index d1f3a906c0..d93e28e3ec 100644
--- a/include/ns16550.h
+++ b/include/ns16550.h
@@ -170,3 +170,16 @@ void NS16550_putc(NS16550_t com_port, char c);
 char NS16550_getc(NS16550_t com_port);
 int NS16550_tstc(NS16550_t com_port);
 void NS16550_reinit(NS16550_t com_port, int baud_divisor);
+
+/**
+ * ns16550_calc_divisor() - calculate the divisor given clock and baud rate
+ *
+ * Given the UART input clock and required baudrate, calculate the divisor
+ * that should be used.
+ *
+ * @port:	UART port
+ * @clock:	UART input clock speed in Hz
+ * @baudrate:	Required baud rate
+ * @return baud rate divisor that should be used
+ */
+int ns16550_calc_divisor(NS16550_t port, int clock, int baudrate);