Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Tue, 20 Sep 2022 13:20:11 +0200
From:   Lukas Wunner <lukas@wunner.de>
To:     Ilpo =?iso-8859-1?Q?J=E4rvinen?= <ilpo.jarvinen@linux.intel.com>
Cc:     linux-serial@vger.kernel.org, Greg KH <gregkh@linuxfoundation.org>,
        Jiri Slaby <jirislaby@kernel.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Arnd Bergmann <arnd@arndb.de>, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= 
        <u.kleine-koenig@pengutronix.de>,
        Lino Sanfilippo <LinoSanfilippo@gmx.de>,
        linux-api@vger.kernel.org
Subject: Re: [PATCH v9 5/6] serial: Support for RS-485 multipoint addresses
Message-ID: <20220920112011.GA7187@wunner.de>
References: <20220624204210.11112-1-ilpo.jarvinen@linux.intel.com>
 <20220624204210.11112-6-ilpo.jarvinen@linux.intel.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <20220624204210.11112-6-ilpo.jarvinen@linux.intel.com>
User-Agent: Mutt/1.10.1 (2018-07-13)
Precedence: bulk

On Fri, Jun 24, 2022 at 11:42:09PM +0300, Ilpo J?rvinen wrote:
> ADDRB in termios indicates 9th bit addressing mode is enabled. In this
> mode, 9th bit is used to indicate an address (byte) within the
> communication line. ADDRB can only be enabled/disabled through
> ->rs485_config() that is also responsible for setting the destination and
> receiver (filter) addresses.
[...]
> --- a/include/uapi/asm-generic/termbits-common.h
> +++ b/include/uapi/asm-generic/termbits-common.h
> @@ -46,6 +46,7 @@ typedef unsigned int	speed_t;
>  #define EXTA		B19200
>  #define EXTB		B38400
>  
> +#define ADDRB		0x20000000	/* address bit */
>  #define CMSPAR		0x40000000	/* mark or space (stick) parity */
>  #define CRTSCTS		0x80000000	/* flow control */
>

You may want to consider submitting a patch to the Linux man-pages
project to document the newly introduced bit:

https://www.kernel.org/doc/man-pages/patches.html
https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/man3/termios.3

Thanks,

Lukas