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From: andy.yan@rock-chips•com (Andy Yan)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2 2/4] power: reset: add reboot mode driver
Date: Tue, 19 Jan 2016 16:38:20 +0800	[thread overview]
Message-ID: <569DF5FC.1080402@rock-chips.com> (raw)
In-Reply-To: <CALAqxLVNUG_cVbavXC34sNPv68jbMghti31+PrgQ7mpPngXh6g@mail.gmail.com>

Hi John:

On 2016?01?16? 04:27, John Stultz wrote:
> On Tue, Jan 12, 2016 at 3:31 AM, Andy Yan <andy.yan@rock-chips•com> wrote:
>> This driver parse the reboot commands like "reboot loader"
>> and "reboot recovery" to get a boot mode described in the
>> device tree , then call the write interfae to store the boot
>> mode in some persistent storage  like special register or ram,
>> which can be read by the bootloader after system reboot, then
>> the bootloader can take different action according to the mode
>> stored.
>>
>> This is commonly used on Android based devices, which in order
>> to reboot the device into fastboot or recovery mode.
>>
>> Signed-off-by: Andy Yan <andy.yan@rock-chips•com>
>
> Hey Andy!
>    Thanks for keeping this work going! I've just successfully reworked
> my Nexus7 tree to use your implementation (using the syscon version,
> setting up a syscon for IMEM as Bjorn had requested earlier).
>
> All is working well so far!
>
> The one thing I was working on supporting with my own version that
> seems to be missing here are for devices that use string based codes,
> rather then magic numbers.
>
> This was mostly a theoretical issue. I think the Galaxy Nexus used it,
> and when I was looking at some of the HTC devices, they support a text
> based reason along with the magic code, but at least in some
> implementations the text mode isn't used, so I suspect there its just
> for extra debugging.  So this may not be critical to solve until
> someone tries to add support for such a device.
>
> Anyway, I'm going to look at porting this to the HiKey board next
> (which just uses reserved ram, not syscon), so I'll try to do a an
> SRAM driver implementaiton to see how that goes.
>
> thanks!
> -john
>
>
>
>

  Very glad to hear news from you. And welcome your SRAM based driver 
implementation.

  reply	other threads:[~2016-01-19  8:38 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-12 11:27 [PATCH v2 0/4] add reboot mode driver Andy Yan
2016-01-12 11:29 ` [PATCH v2 1/4] dt-bindings: power: reset: add document for reboot-mode driver Andy Yan
2016-01-15 22:41   ` John Stultz
2016-01-19  8:31     ` Andy Yan
2016-01-20 18:28   ` Rob Herring
2016-01-20 18:47     ` John Stultz
2016-01-20 19:53       ` Rob Herring
2016-01-20 20:25         ` John Stultz
2016-01-21  6:27     ` Andy Yan
2016-01-25 17:11       ` Rob Herring
2016-01-26  7:35         ` Andy Yan
2016-01-12 11:31 ` [PATCH v2 2/4] power: reset: add reboot mode driver Andy Yan
2016-01-15 20:27   ` John Stultz
2016-01-19  8:38     ` Andy Yan [this message]
2016-01-21  8:37   ` Matthias Brugger
2016-01-27 10:53   ` Moritz Fischer
2016-02-02  7:31     ` Andy Yan
2016-01-12 11:32 ` [PATCH v2 3/4] ARM: dts: rockchip: add syscon-reboot-mode node Andy Yan
2016-01-21  8:38   ` Matthias Brugger
2016-01-12 11:33 ` [PATCH v2 4/4] ARM64: dts: rockchip: add syscon-reboot-mode DT node Andy Yan
2016-01-13  2:17 ` [PATCH v2 0/4] add reboot mode driver Caesar Wang

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