From 04bc5c939a79c796374ffb93251841317ef8cf6f Mon Sep 17 00:00:00 2001
From: Michal Simek <michal.simek@xilinx.com>
Date: Wed, 15 Apr 2015 13:05:06 +0200
Subject: [PATCH] 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>
---
 drivers/serial/serial_zynq.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/serial/serial_zynq.c b/drivers/serial/serial_zynq.c
index 3e2b8dc183..9278763164 100644
--- a/drivers/serial/serial_zynq.c
+++ b/drivers/serial/serial_zynq.c
@@ -48,10 +48,16 @@ static void uart_zynq_serial_setbrg(const int port)
 	/* 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)
-- 
2.39.5