Fix serial console on SNI RM400 machines

sccnxp driver doesn't get the correct uart clock rate, if CONFIG_HAVE_CLOCK
is disabled. Correct usage of clk API to make it work with/without it.

Fixes: 90efa75f7ab0 (serial: sccnxp: Using CLK API for getting UART clock)

Suggested-by: Russell King - ARM Linux <linux@armlinux.org.uk>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 10 insertions, 5 deletions

diff --git a/drivers/tty/serial/sccnxp.c b/drivers/tty/serial/sccnxp.c
index fcf803ffad19..cdd2f942317c 100644
--- a/drivers/tty/serial/sccnxp.c
+++ b/drivers/tty/serial/sccnxp.c
@@ -884,14 +884,19 @@ static int sccnxp_probe(struct platform_device *pdev)
 
         clk = devm_clk_get(&pdev->dev, NULL);
         if (IS_ERR(clk)) {
-                if (PTR_ERR(clk) == -EPROBE_DEFER) {
-                        ret = -EPROBE_DEFER;
+                ret = PTR_ERR(clk);
+                if (ret == -EPROBE_DEFER)
                         goto err_out;
-                }
+                uartclk = 0;
+        } else {
+                clk_prepare_enable(clk);
+                uartclk = clk_get_rate(clk);
+        }
+
+        if (!uartclk) {
                 dev_notice(&pdev->dev, "Using default clock frequency\n");
                 uartclk = s->chip->freq_std;
-        } else
-                uartclk = clk_get_rate(clk);
+        }
 
         /* Check input frequency */
         if ((uartclk < s->chip->freq_min) || (uartclk > s->chip->freq_max)) {