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Subject: Re: [PATCH v3 5/5] serial: 8250_dw: add em485 support
To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Heiko Stuebner <heiko@sntech.de>
Cc:     gregkh@linuxfoundation.org, jslaby@suse.com,
        matwey.kornilov@gmail.com, lukas@wunner.de,
        linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org,
        christoph.muellner@theobroma-systems.com,
        Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
References: <20200517215610.2131618-1-heiko@sntech.de>
 <20200517215610.2131618-6-heiko@sntech.de>
 <20200518152103.GI1634618@smile.fi.intel.com>
From:   Giulio Benetti <giulio.benetti@micronovasrl.com>
Message-ID: <1f7881b5-f900-dbbe-3f8d-f990d2bdf5a7@micronovasrl.com>
Date:   Tue, 2 Feb 2021 01:31:17 +0100
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Hi Andy,

Il 18/05/2020 17:21, Andy Shevchenko ha scritto:
> On Sun, May 17, 2020 at 11:56:10PM +0200, Heiko Stuebner wrote:
>> From: Giulio Benetti <giulio.benetti@micronovasrl.com>
>>
>> Need to use rs485 transceiver so let's use existing em485 485 emulation
>> layer on top of 8250.
>>
>> Add rs485_config callback to port and uses the standard em485 start and
>> stop helpers.
> 
> Would it prevent to use native RS485 support?

8250_dw doesn't have a native RS485 support, do you mean using hardware
RTS assertion? Anyway at the moment it's not present. This would be the
first rs485 support added to 8250_dw.

Best regards
-- 
Giulio Benetti
CTO

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> ...
> 
>>   	p->serial_out	= dw8250_serial_out;
>>   	p->set_ldisc	= dw8250_set_ldisc;
>>   	p->set_termios	= dw8250_set_termios;
>> +	p->rs485_config = serial8250_em485_config;
>> +	up->rs485_start_tx = serial8250_em485_start_tx;
>> +	up->rs485_stop_tx = serial8250_em485_stop_tx;
>