serial: zynq: Add support for slow emulation platform
On slow platforms not all baudrate setting is valid.
Check it directly in the driver and setup maximum possible
frequency.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/drivers/serial/serial_zynq.c b/drivers/serial/serial_zynq.c
index 3e2b8dc..9278763 100644
--- a/drivers/serial/serial_zynq.c
+++ b/drivers/serial/serial_zynq.c
@@ -48,10 +48,16 @@
/* Calculation results. */
unsigned int calc_bauderror, bdiv, bgen;
unsigned long calc_baud = 0;
- unsigned long baud = gd->baudrate;
+ unsigned long baud;
unsigned long clock = get_uart_clk(port);
struct uart_zynq *regs = uart_zynq_ports[port];
+ /* Covering case where input clock is so slow */
+ if (clock < 1000000 && gd->baudrate > 4800)
+ gd->baudrate = 4800;
+
+ baud = gd->baudrate;
+
/* master clock
* Baud rate = ------------------
* bgen * (bdiv + 1)