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[v4,0/2] Implement support for inverted serial TX/RX on i.MX

Message ID 20200226222319.18383-1-ghilliard@kopismobile.com
Headers show
Series Implement support for inverted serial TX/RX on i.MX | expand

Message

George Hilliard Feb. 26, 2020, 10:23 p.m. UTC 
This peripheral has dedicated control bits that flip input/output
signals before handing them off to the OS.  This is useful on my
hardware because the UART is connected to an RS-422 transceiver with the
+/- pins hooked up backward.  Instead of a hack flipping all the bits
before sending them, the hardware can do it for free.

v4 cleans up the bit manipulation in v3; see previous series at
https://lore.kernel.org/linux-serial/20200212163538.3006-1-ghilliard@kopismobile.com/

George Hilliard (2):
  dt-bindings: serial: document fsl,inverted-tx and -rx options
  tty: imx serial: Implement support for reversing TX and RX polarity

 .../bindings/serial/fsl-imx-uart.txt          |  4 ++
 drivers/tty/serial/imx.c                      | 44 ++++++++++++-------
 2 files changed, 32 insertions(+), 16 deletions(-)