From: Greg KH <gregkh@linuxfoundation.org>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Cyril Bur <cyrilbur@gmail.com>,
devicetree@vger.kernel.org, jassisinghbrar@gmail.com,
arnd@arndb.de, joel@jms.id.au, mark.rutland@arm.com,
robh+dt@kernel.org, openbmc@lists.ozlabs.org, andrew@aj.id.au,
xow@google.com, jk@ozlabs.org
Subject: Re: [PATCH 3/4] drivers/misc: Add ASpeed LPC control driver
Date: Thu, 12 Jan 2017 18:27:13 +0100 [thread overview]
Message-ID: <20170112172713.GF13342@kroah.com> (raw)
In-Reply-To: <1484238577.2492.45.camel@kernel.crashing.org>
On Thu, Jan 12, 2017 at 10:29:37AM -0600, Benjamin Herrenschmidt wrote:
> So I think the best approach here is:
>
> - A pair of ioctls to read and write random registers in the
> LPC bridge for all the "generally configuration gunk". These have a
> filter to ensure that the registers controlling the above mapping
> cannot be accessed that way.
>
> - An ioctl to control the above mapping window. It takes as
> arguments the location in LPC space, the window type (flash vs.
> memory), for memory, maybe an ID (several windows to chose from), and
> the offset& size in the latter. The driver can enforce that the windows
> are one of the specially reserved areas of memory etc...
>
> - An mmap function to map those reserved windows into userspace
> so the daemon can communicate appropriately (only needed for the memory
> windows, the flash space is accessed via the normal /dev/mtd drivers)
>
> Greg, does that make sense ?
Yes, that makes a lot more sense to me. Thanks for writing it up,
hopefully it survives into the next driver submission, otherwise I'll
ask the same questions again due to not having a short-term memory at
all :)
thanks,
greg k-h
WARNING: multiple messages have this Message-ID (diff)
From: Greg KH <gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org>
To: Benjamin Herrenschmidt
<benh-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>
Cc: Cyril Bur <cyrilbur-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
jassisinghbrar-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
arnd-r2nGTMty4D4@public.gmane.org,
joel-U3u1mxZcP9KHXe+LvDLADg@public.gmane.org,
mark.rutland-5wv7dgnIgG8@public.gmane.org,
robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
openbmc-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org,
andrew-zrmu5oMJ5Fs@public.gmane.org,
xow-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org,
jk-mnsaURCQ41sdnm+yROfE0A@public.gmane.org
Subject: Re: [PATCH 3/4] drivers/misc: Add ASpeed LPC control driver
Date: Thu, 12 Jan 2017 18:27:13 +0100 [thread overview]
Message-ID: <20170112172713.GF13342@kroah.com> (raw)
In-Reply-To: <1484238577.2492.45.camel-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>
On Thu, Jan 12, 2017 at 10:29:37AM -0600, Benjamin Herrenschmidt wrote:
> So I think the best approach here is:
>
> - A pair of ioctls to read and write random registers in the
> LPC bridge for all the "generally configuration gunk". These have a
> filter to ensure that the registers controlling the above mapping
> cannot be accessed that way.
>
> - An ioctl to control the above mapping window. It takes as
> arguments the location in LPC space, the window type (flash vs.
> memory), for memory, maybe an ID (several windows to chose from), and
> the offset& size in the latter. The driver can enforce that the windows
> are one of the specially reserved areas of memory etc...
>
> - An mmap function to map those reserved windows into userspace
> so the daemon can communicate appropriately (only needed for the memory
> windows, the flash space is accessed via the normal /dev/mtd drivers)
>
> Greg, does that make sense ?
Yes, that makes a lot more sense to me. Thanks for writing it up,
hopefully it survives into the next driver submission, otherwise I'll
ask the same questions again due to not having a short-term memory at
all :)
thanks,
greg k-h
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next prev parent reply other threads:[~2017-01-12 17:26 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-12 0:29 [PATCH 0/4] ASpeed mailbox and LPC control drivers Cyril Bur
2017-01-12 0:29 ` Cyril Bur
2017-01-12 0:29 ` [PATCH 1/4] Documentation: dt: mailbox: Add Aspeed ast2400/2500 bindings Cyril Bur
2017-01-12 0:29 ` Cyril Bur
2017-01-18 20:38 ` Rob Herring
2017-01-18 20:38 ` Rob Herring
2017-01-19 0:05 ` Cyril Bur
2017-01-19 0:05 ` Cyril Bur
2017-01-19 15:08 ` Benjamin Herrenschmidt
2017-01-19 15:08 ` Benjamin Herrenschmidt
2017-01-12 0:29 ` [PATCH 2/4] Documentation: dt: misc: Add Aspeed ast2400/2500 LPC Control bindings Cyril Bur
2017-01-12 0:29 ` Cyril Bur
2017-01-18 21:16 ` Rob Herring
2017-01-18 21:16 ` Rob Herring
2017-01-19 0:19 ` Cyril Bur
2017-01-19 0:19 ` Cyril Bur
2017-01-12 0:29 ` [PATCH 3/4] drivers/misc: Add ASpeed LPC control driver Cyril Bur
2017-01-12 0:29 ` Cyril Bur
2017-01-12 7:43 ` Greg KH
2017-01-12 7:43 ` Greg KH
2017-01-12 15:36 ` Benjamin Herrenschmidt
2017-01-12 15:36 ` Benjamin Herrenschmidt
2017-01-12 7:47 ` Greg KH
2017-01-12 7:47 ` Greg KH
2017-01-12 10:16 ` Cyril Bur
2017-01-12 10:16 ` Cyril Bur
2017-01-12 10:30 ` Greg KH
2017-01-12 10:30 ` Greg KH
2017-01-12 15:27 ` Benjamin Herrenschmidt
2017-01-12 15:27 ` Benjamin Herrenschmidt
2017-01-12 16:00 ` Greg KH
2017-01-12 16:00 ` Greg KH
2017-01-12 16:07 ` Benjamin Herrenschmidt
2017-01-12 16:07 ` Benjamin Herrenschmidt
2017-01-12 16:26 ` Greg KH
2017-01-12 16:26 ` Greg KH
2017-01-12 16:31 ` Benjamin Herrenschmidt
2017-01-12 16:31 ` Benjamin Herrenschmidt
2017-01-12 15:35 ` Benjamin Herrenschmidt
2017-01-12 15:35 ` Benjamin Herrenschmidt
2017-01-12 16:27 ` Greg KH
2017-01-12 16:27 ` Greg KH
2017-01-12 16:29 ` Benjamin Herrenschmidt
2017-01-12 16:29 ` Benjamin Herrenschmidt
2017-01-12 17:27 ` Greg KH [this message]
2017-01-12 17:27 ` Greg KH
2017-01-12 0:29 ` [PATCH 4/4] drivers/mailbox: Add ASpeed mailbox driver Cyril Bur
2017-01-12 0:29 ` Cyril Bur
2017-02-07 5:40 ` Joel Stanley
2017-02-07 5:40 ` Joel Stanley
2017-02-07 5:44 ` Benjamin Herrenschmidt
2017-02-07 5:44 ` Benjamin Herrenschmidt
2017-02-07 22:57 ` Cyril Bur
2017-02-07 22:57 ` Cyril Bur
2017-02-07 22:59 ` Joel Stanley
2017-02-07 22:59 ` Joel Stanley
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