Date: Tue, 22 Oct 2013 11:50:04 -0700
From: Bin Gao <bin.gao@linux.intel.com>
To: Guenter Roeck <linux@roeck-us.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Arnd Bergmann <arnd@arndb.de>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/4] drivers/misc: add rawio framework and drivers
Message-ID: <20131022185004.GC53231@bingao-desk1.fm.intel.com>
References: <5265C0C5.70905@linux.intel.com>
 <20131022054406.GA14163@kroah.com>
 <20131022171400.GA14558@roeck-us.net>
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On Tue, Oct 22, 2013 at 10:14:00AM -0700, Guenter Roeck wrote:
> > 
> > You can already do this today for PCI with the UIO framework, right?
> > Why duplicate that functionality here with another userapce API that we
> > will then have to maintain for the next 40+ years?
> > 
> Same for i2c, where the same functionality is supported through i2c-tools and
> the i2c-dev driver. Adding i2c-tools to initramfs and/or to the root file system
> should not be that much of an issue, much less than having to maintain two APIs
> for the same purpose.
> 
> Guenter

For PCI and memory mapped I/O devices, we have the runtime pm issue that has to
be addressed from kernel space.
For I2C slave devices, there is no such a issue so yes i2c-tools and i2c-dev drivers
are fine. But the two APIs are required by PCI and memory mapped I/O devices anyway.
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