From: Kumar Gala <kumar.gala@freescale.com>
To: "Russell King" <rmk+lkml@arm.linux.org.uk>
Cc: "Linux Kernel list" <linux-kernel@vger.kernel.org>,
"Greg KH" <greg@kroah.com>
Subject: Re: serial8250_init and platform_device
Date: Thu, 20 Jan 2005 14:26:30 -0600 [thread overview]
Message-ID: <91CB879A-6B21-11D9-BD44-000393DBC2E8@freescale.com> (raw)
In-Reply-To: <20050120193845.H13242@flint.arm.linux.org.uk>
Good, I can understand the need to maintain compatibility until we get
ride of SERIAL_PORT_DFNS.
- kumar
On Jan 20, 2005, at 1:38 PM, Russell King wrote:
> On Thu, Jan 20, 2005 at 01:06:55PM -0600, Kumar Gala wrote:
> > Russell,
> >
> > I think this all makes sense to me. I'm just wondering why we would
> > have a platform device register in a system for 'legacy ISA' when we
> > know the system doesnt have any ports that will fit the category.
> >
> > As you show in example #2 you have
> >
> > .../devices/platform/serial82500
> > .../devices/platform/serial8250
> >
> > why have the 'serial8250' if you know your system doesnt have any
> ports
> > that will exist there?
>
> In this case, it is a placeholder, and needs to be there if you're
> using
> power management.
>
> For instance, you may use setserial on /dev/ttyS2 to reconfigure it
> to an address where you know a serial port is. Without the
> "serial8250"
> device, it isn't linked into the device model, and therefore doesn't
> receive any power management notifications.
>
> Once the SERIAL_PORT_DFNS are gone, and we have a more modern interface
> than setserial for setting up random ports, this "serial8250" device
> will vanish.
>
> While we're here, you've reminded me about an annoying point about
> platform device naming...
>
> Greg - the name is constructed from "name" + "id num" thusly:
>
> serial8250
> serial82500
> serial82501
> serial82502
>
> When "name" ends in a number, it gets rather confusing. Can we have
> an optional delimiter in there when we append the ID number, maybe
> something like a '.' or ':' ?
>
> --
> Russell King
> Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
> maintainer of: 2.6 PCMCIA - http://pcmcia.arm.linux.org.uk/
> 2.6 Serial core
prev parent reply other threads:[~2005-01-20 20:29 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-01-20 7:14 serial8250_init and platform_device Kumar Gala
2005-01-20 11:43 ` Russell King
2005-01-20 15:23 ` Kumar Gala
2005-01-20 15:44 ` Russell King
2005-01-20 19:06 ` Kumar Gala
2005-01-20 19:38 ` Russell King
2005-01-20 19:50 ` Greg KH
2005-01-20 20:10 ` Russell King
2005-01-20 20:25 ` Kumar Gala
2005-02-01 8:41 ` Greg KH
2005-01-20 20:26 ` Kumar Gala [this message]
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