tree f37856c6234d03687e44d6003bee49d770d32e63
parent 2e6514aad1e5a02ba17c172c367dc554dc343c1f
author Joe Burmeister <joe.burmeister@devtank.co.uk> 1557743037 +0100
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1560248562 +0200

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>