[U-Boot] [PATCH V2] imx: mx7: psci: add system reset support

[Anson Huang]

Hi, Fabio

Best Regards!
Anson Huang


> -----Original Message-----
> From: Fabio Estevam [mailto:festevam at gmail.com]
> Sent: 2018-01-04 8:57 PM
> To: Anson Huang <anson.huang at nxp.com>
> Cc: Stefano Babic <sbabic at denx.de>; Fabio Estevam
> <fabio.estevam at nxp.com>; Albert ARIBAUD <albert.u.boot at aribaud.net>;
> Christian Gmeiner <christian.gmeiner at gmail.com>; Peng Fan
> <peng.fan at nxp.com>; U-Boot-Denx <u-boot at lists.denx.de>
> Subject: Re: [U-Boot] [PATCH V2] imx: mx7: psci: add system reset support
> 
> Hi Anson,
> 
> On Thu, Jan 4, 2018 at 7:03 AM, Anson Huang <Anson.Huang at nxp.com> wrote:
> > Add i.MX7 PSCI system reset support, linux kernel now can use "reboot"
> > command to reset system.
> 
> Reading this commit message gives me the impression that the 'reboot'
> command does not work currently.
> 
> However, the 'reboot' command works provided the boards connects the
> WDOG output pin to the PMIC  due to the MX7 erratum.
> 
> What exactly are you fixing here? Please clarify.

Thanks for the comments, the current reboot command works is just
because wdog driver is enabled and when system reboot, the reboot notification
callback in wdog driver will do reset. But if wdog is disabled in dtb, the reboot
command will fail.

As now we use PSCI, the reboot operation will eventually call into u-boot's psci
reset callback, we should support this feature, the reboot feature in Linux kernel
should NOT depends on wdog's existence.

But I did notice that I miss a change to enable the psci reset feature, we should
Use psci 1.0 instead of 0.1, psci 0.1 only supports very limited features which does
NOT include system reset, power off etc..

So I re-send a patch series to do these changes, to support PSCI system reset, system
power off, please help review, thanks.

Anson.