From: Joe Burmeister Date: Mon, 13 May 2019 10:23:57 +0000 (+0100) Subject: tty: max310x: Fix external crystal register setup X-Git-Tag: v4.14.124~21 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=3d3494aa6609d2acc5e37f09a95a13bc41868af8;p=users%2Fdwmw2%2Flinux.git 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 Cc: stable Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c index 54660002271a1..1a98b6631e906 100644 --- a/drivers/tty/serial/max310x.c +++ b/drivers/tty/serial/max310x.c @@ -579,7 +579,7 @@ static int max310x_set_ref_clk(struct max310x_port *s, unsigned long freq, } /* 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) {