[U-Boot] [PATCH v5 10/14] dm: serial: Move baud rate calculation to ns16550.c
Simon Glass
sjg at chromium.org
Fri Sep 5 00:27:32 CEST 2014
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 at chromium.org>
---
Changes in v5: None
Changes in v4: None
Changes in v3:
- Add new patch to move baud rate calculation to ns16550.c
Changes in v2: None
drivers/serial/ns16550.c | 18 +++++++++++++++++-
drivers/serial/serial_ns16550.c | 14 ++++----------
include/ns16550.h | 13 +++++++++++++
3 files changed, 34 insertions(+), 11 deletions(-)
diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
index 079f67d..3f5f4ef 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 dafeed7..632da4c 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 d1f3a90..d93e28e 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);
--
2.1.0.rc2.206.gedb03e5
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