tty: max310x: Fix external crystal register setup
commit 5d24f455c182d5116dd5db8e1dc501115ecc9c2c upstream.
The datasheet states:
Bit 4: ClockEnSet the ClockEn bit high to enable an external clocking
(crystal or clock generator at XIN). Set the ClockEn bit to 0 to disable
clocking
Bit 1: CrystalEnSet the CrystalEn bit high to enable the crystal
oscillator. When using an external clock source at XIN, CrystalEn must
be set low.
The bit 4, MAX310X_CLKSRC_EXTCLK_BIT, should be set and was not.
This was required to make the MAX3107 with an external crystal on our
board able to send or receive data.
Signed-off-by: Joe Burmeister <joe.burmeister@devtank.co.uk>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
index 5331baf..ec3db8d 100644
--- a/drivers/tty/serial/max310x.c
+++ b/drivers/tty/serial/max310x.c
@@ -579,7 +579,7 @@
}
/* Configure clock source */
- clksrc = xtal ? MAX310X_CLKSRC_CRYST_BIT : MAX310X_CLKSRC_EXTCLK_BIT;
+ clksrc = MAX310X_CLKSRC_EXTCLK_BIT | (xtal ? MAX310X_CLKSRC_CRYST_BIT : 0);
/* Configure PLL */
if (pllcfg) {