[PATCH 3.16 013/192] Fix serial console on SNI RM400 machines

Ben Hutchings
2017-10-09T14:01:10Z

From: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

commit e279e6d98e0cf2c2fe008b3c29042b92f0e17b1d upstream.

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>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/tty/serial/sccnxp.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)

--- a/drivers/tty/serial/sccnxp.c
+++ b/drivers/tty/serial/sccnxp.c
@@ -890,14 +890,19 @@ static int sccnxp_probe(struct platform_

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)) {