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Date:   Fri, 31 Mar 2023 12:59:33 -0500
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Subject: Re: [PATCH tty-next 2/2] serial: 8250: add driver for NI UARTs
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To:     =?UTF-8?Q?Ilpo_J=c3=a4rvinen?= <ilpo.jarvinen@linux.intel.com>
Cc:     Gratian Crisan <gratian.crisan@ni.com>,
        Jason Smith <jason.smith@ni.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Jiri Slaby <jirislaby@kernel.org>,
        linux-serial <linux-serial@vger.kernel.org>,
        devicetree@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>
References: <20230329154235.615349-1-brenda.streiff@ni.com>
 <20230329154235.615349-3-brenda.streiff@ni.com>
 <4687fc63-65ad-c717-70b4-731079be38f7@linux.intel.com>
From:   Brenda Streiff <brenda.streiff@ni.com>
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On 3/31/23 06:46, Ilpo Järvinen wrote:
> On Wed, 29 Mar 2023, Brenda Streiff wrote:
> 
>> +static int ni16550_get_regs(struct platform_device *pdev,
>> +			    struct uart_port *port)
>> +{
>> +	struct resource *regs;
>> +
>> +	regs = platform_get_resource(pdev, IORESOURCE_IO, 0);
>> +	if (regs) {
>> +		port->iotype = UPIO_PORT;
>> +		port->iobase = regs->start;
>> +
>> +		return 0;
>> +	}
> 
> Do you need the port io?

Yes; on our x86_64 hardware this UART IP is in logic connected to LPC,
and the registers lie in I/O port space.


>> +	int irq;
>> +	int rs232_property = 0;
>> +	unsigned int prescaler;
>> +	const char *transceiver;
>> +	int txfifosz, rxfifosz;
> 
> Try to follow reverse xmas-tree order.

Is reverse xmas tree also the rule in the tty subsystem? I was aware of
it for netdev but I thought that was a netdev-specific rule (since it
only shows up in maintainer-netdev.rst and not more broadly)