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path: root/drivers/serial/ns16550.c
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Diffstat (limited to 'drivers/serial/ns16550.c')
-rw-r--r--drivers/serial/ns16550.c20
1 files changed, 18 insertions, 2 deletions
diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
index f9041aa626..1e6fc6c668 100644
--- a/drivers/serial/ns16550.c
+++ b/drivers/serial/ns16550.c
@@ -267,12 +267,26 @@ static inline void _debug_uart_init(void)
serial_dout(&com_port->lcr, UART_LCRVAL);
}
+static inline int NS16550_read_baud_divisor(struct NS16550 *com_port)
+{
+ int ret;
+
+ serial_dout(&com_port->lcr, UART_LCR_BKSE | UART_LCRVAL);
+ ret = serial_din(&com_port->dll) & 0xff;
+ ret |= (serial_din(&com_port->dlm) & 0xff) << 8;
+ serial_dout(&com_port->lcr, UART_LCRVAL);
+
+ return ret;
+}
+
static inline void _debug_uart_putc(int ch)
{
struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
- while (!(serial_din(&com_port->lsr) & UART_LSR_THRE))
- ;
+ while (!(serial_din(&com_port->lsr) & UART_LSR_THRE)) {
+ if (!NS16550_read_baud_divisor(com_port))
+ return;
+ }
serial_dout(&com_port->thr, ch);
}
@@ -473,7 +487,9 @@ U_BOOT_DRIVER(ns16550_serial) = {
.priv_auto_alloc_size = sizeof(struct NS16550),
.probe = ns16550_serial_probe,
.ops = &ns16550_serial_ops,
+#if !CONFIG_IS_ENABLED(OF_CONTROL)
.flags = DM_FLAG_PRE_RELOC,
+#endif
};
#endif
#endif /* SERIAL_PRESENT */