serial_mxc: Fix setup of UARTx_UFCR register
This patch writes the default values for TXTL and RXTL to UARTx_UFCR.
Without this patch some older kernel versions crash as UARTx_UFCR was
not always correctly initialized.
Signed-off-by: Maximilian Schwerin <maximilian.schwerin@tigris.de>
diff --git a/drivers/serial/serial_mxc.c b/drivers/serial/serial_mxc.c
index d6cf1d8..51485c0 100644
--- a/drivers/serial/serial_mxc.c
+++ b/drivers/serial/serial_mxc.c
@@ -75,6 +75,7 @@
#define UCR4_DREN (1<<0) /* Recv data ready interrupt enable */
#define UFCR_RXTL_SHF 0 /* Receiver trigger level shift */
#define UFCR_RFDIV (7<<7) /* Reference freq divider mask */
+#define UFCR_RFDIV_SHF 7 /* Reference freq divider shift */
#define UFCR_TXTL_SHF 10 /* Transmitter trigger level shift */
#define USR1_PARITYERR (1<<15) /* Parity error interrupt flag */
#define USR1_RTSS (1<<14) /* RTS pin status */
@@ -135,6 +136,10 @@
DECLARE_GLOBAL_DATA_PTR;
+#define TXTL 2 /* reset default */
+#define RXTL 1 /* reset default */
+#define RFDIV 4 /* divide input clock by 2 */
+
static void mxc_serial_setbrg(void)
{
u32 clk = imx_get_uartclk();
@@ -142,7 +147,9 @@
if (!gd->baudrate)
gd->baudrate = CONFIG_BAUDRATE;
- __REG(UART_PHYS + UFCR) = 4 << 7; /* divide input clock by 2 */
+ __REG(UART_PHYS + UFCR) = (RFDIV << UFCR_RFDIV_SHF)
+ | (TXTL << UFCR_TXTL_SHF)
+ | (RXTL << UFCR_RXTL_SHF);
__REG(UART_PHYS + UBIR) = 0xf;
__REG(UART_PHYS + UBMR) = clk / (2 * gd->baudrate);