Re: [PATCH v2] ARM: dts: sunxi: Add sid for a83t

From: Kyle Evans
Date: Mon Jan 08 2018 - 10:31:36 EST


On Thu, Jan 4, 2018 at 8:01 AM, Maxime Ripard
<maxime.ripard@xxxxxxxxxxxxxxxxxx> wrote:
> On Fri, Dec 22, 2017 at 06:11:52PM +0800, Chen-Yu Tsai wrote:
>> On Fri, Dec 22, 2017 at 6:07 PM, Emmanuel Vadot <manu@xxxxxxxxxxxxxxxx> wrote:
>> > On Fri, 22 Dec 2017 09:35:08 +0100
>> > Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> wrote:
>> >
>> >> On Thu, Dec 21, 2017 at 07:09:03PM +0100, Emmanuel Vadot wrote:
>> >> >
>> >> > Hi Maxime,
>> >> >
>> >> > On Thu, 21 Dec 2017 16:26:30 +0100
>> >> > Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> wrote:
>> >> >
>> >> > > Hi,
>> >> > >
>> >> > > On Thu, Dec 21, 2017 at 09:19:24AM -0600, Kyle Evans wrote:
>> >> > > > On Thu, Dec 21, 2017 at 8:55 AM, Maxime Ripard
>> >> > > > <maxime.ripard@xxxxxxxxxxxxxxxxxx> wrote:
>> >> > > > > Hi Kyle,
>> >> > > > >
>> >> > > > > On Tue, Dec 19, 2017 at 03:05:23PM -0600, kevans91@xxxxxxx wrote:
>> >> > > > >> Allwinner a83t has a 1 KB sid block with efuse for security rootkey and
>> >> > > > >> thermal calibration data, add node to describe it.
>> >> > > > >>
>> >> > > > >> a83t-sid is not currently supported by nvmem/sunxi-sid, but it is
>> >> > > > >> supported in an external driver for FreeBSD.
>> >> > > > >>
>> >> > > > >> Signed-off-by: Kyle Evans <kevans91@xxxxxxx>
>> >> > > > >
>> >> > > > > The patch looks fine in itself, but we've had a number of issues with
>> >> > > > > the register layout (and access patterns) in the past, so I'd rather
>> >> > > > > have something that works in Linux too if possible.
>> >> > > >
>> >> > > > I have a patch that I think should make it work fine on Linux [1], but
>> >> > > > I'm afraid I have little to no capability to test it myself and so I
>> >> > > > did not add it as well.
>> >> > > >
>> >> > > > I do know that the rootkey is offset 0x200 into the given space [2],
>> >> > > > as is the case with the H3, and that the readout quirk is not needed.
>> >> > > > I wasn't 100% sure that the a83t has 2Kbit worth of efuse space as the
>> >> > > > H3, but I do know that thermal data can be found at 0x34 and 0x38 in
>> >> > > > this space.
>> >> > >
>> >> > > Then maybe we should leave it aside until someone takes some time on
>> >> > > the A83t.
>> >> >
>> >> > Take some time on the Linux driver and do not apply this patch for
>> >> > now you mean ?
>> >>
>> >> Yep.
>> >>
>> >> Maxime
>> >
>> > Since linux doesn't have the compatible in it's driver what would
>> > be the harm to add the node in the DTS ? If a quirks is needed because
>> > some region is weird this would go in the driver right ? I don't see a
>> > technical problem for adding this node right now.
>> > If Kyle confirm the lenght of the region and that no quirk is needed
>> > will it be enough ?
>>
>> I guess I wasn't very clear. I'm OK with the patch going in. The device
>> node currently says nothing about how much efuse space there is. The
>> memory region covers that and the control section, and the size matches
>> what the memory map says.
>>
>> The size and offset of the efuse space would be dealt with in the driver.
>
> Let's merge it then.
>
> Acked-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
>
> Maxime

Hi,

What does the timeline for these things normally look like? I'm new to
these parts. =)

Thanks,

Kyle Evans