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>
This commit is contained in:
Simon Glass 2014-09-04 16:27:32 -06:00
parent 2a9ae6e02f
commit fa54eb1243
3 changed files with 34 additions and 11 deletions

View file

@ -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))

View file

@ -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);
}

View file

@ -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);