PPC32: fix serial clock for embedded EP405 board.

diff --git a/arch/ppc/boot/simple/embed_config.c b/arch/ppc/boot/simple/embed_config.c
index 5c37dd3a6394eb33f189cd18a020a2a0f287c01a..8ef9ca4ae2111ef07c72f7c90814deb7203be687 100644 (file)
--- a/arch/ppc/boot/simple/embed_config.c
+++ b/arch/ppc/boot/simple/embed_config.c
@@ -706,12 +706,30 @@ embed_config(bd_t **bdp)
 #endif
 
 #ifdef CONFIG_EP405
+#include <linux/serial_reg.h>
+
 void
 embed_config(bd_t **bdp)
 {
+       u32 chcr0;
        u_char *cp;
        bd_t    *bd;
 
+       /* Different versions of the PlanetCore firmware vary in how
+          they set up the serial port - in particular whether they
+          use the internal or external serial clock for UART0.  Make
+          sure the UART is in a known state. */
+       /* FIXME: We should use the board's 11.0592MHz external serial
+          clock - it will be more accurate for serial rates.  For
+          now, however the baud rates in ep405.h are for the internal
+          clock. */
+       chcr0 = mfdcr(DCRN_CHCR0);
+       if ( (chcr0 & 0x1fff) != 0x103e ) {
+               mtdcr(DCRN_CHCR0, (chcr0 & 0xffffe000) | 0x103e);
+               /* The following tricks serial_init() into resetting the baud rate */
+               writeb(0, UART0_IO_BASE + UART_LCR);
+       }
+
        bd = &bdinfo;
        *bdp = bd;
 #if 1