642aa7603e
The Synopsys DesignWare UART can be configured to have HW support for the RS485 protocol from IP version 4.0 onward. Add support for hardware-controlled half duplex and full duplex modes. HW will take care of managing DE and RE, the driver just gives it permission to use either by setting both to 1. To ask for full duplex mode, userspace sets SER_RS485_RX_DURING_TX flag and HW will take care of the rest. Set delay_rts_before_send and delay_rts_after_send to zero for now. The granularity of that ABI is too coarse to be useful. Co-developed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Co-developed-by: Raymond Tan <raymond.tan@intel.com> Signed-off-by: Raymond Tan <raymond.tan@intel.com> Co-developed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220426122448.38997-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.