Re: [PATCH] power: reset: msm: Add support for download-mode control

[Stephen Boyd]

Quoting Stephen Boyd (2018-07-20 10:44:53)
> Quoting Rajendra Nayak (2018-07-18 23:59:20)
> > On 7/19/2018 11:12 AM, Bjorn Andersson wrote:
> > > On Wed 18 Jul 22:18 PDT 2018, Rajendra Nayak wrote:
> > >> diff --git a/Documentation/devicetree/bindings/power/reset/msm-poweroff.txt b/Documentation/devicetree/bindings/power/reset/msm-poweroff.txt
> > >> index ce44ad3..9dd489f 100644
> > >> --- a/Documentation/devicetree/bindings/power/reset/msm-poweroff.txt
> > >> +++ b/Documentation/devicetree/bindings/power/reset/msm-poweroff.txt
> > >> @@ -8,6 +8,9 @@ settings.
> > >>   Required Properties:
> > >>   -compatible: "qcom,pshold"
> > >>   -reg: Specifies the physical address of the ps-hold register
> > >> +Optional Properties:
> > >> +-qcom,dload-mode: phandle to the TCSR hardware block and offset of the
> > >> +             download mode control register
> > >>   
> > >>   Example:
> > >>   
> > >> diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
> > >> index df58fc8..0c97e34 100644
> > >> --- a/drivers/power/reset/Kconfig
> > >> +++ b/drivers/power/reset/Kconfig
> > >> @@ -104,6 +104,17 @@ config POWER_RESET_MSM
> > >>      help
> > >>        Power off and restart support for Qualcomm boards.
> > >>   
> > >> +config POWER_RESET_MSM_DOWNLOAD_MODE
> > > 
> > > How about moving QCOM_SCM_DOWNLOAD_MODE_DEFAULT to
> > > drivers/soc/qcom/Kconfig (and removing "SCM") and referencing this in
> > > both drivers?
> > 
> > yes, thats possible, but I am not sure how to make the command line
> > option common for both. One other option I thought was if we could handle it
> > within the scm driver itself with an additional
> > binding to specify the non-secure download mode address.
> > something like qcom,dload-mode-ns?
> 
> Is the SCM device and driver always going to be present though? It may
> be better to make a TCSR platform device driver on designs that would
> configure the cookie with direct read/writes from Linux to break the
> relationship with scm entirely. Then the different configurations could
> flow from the DTS file either describing scm that has scm call, a
> special scm_writel address for TCSR, or a specific TCSR node with the
> address of the download mode cookie that triggers a TCSR driver to probe
> and register a reboot handler.
> 

Does my proposal work? I haven't seen anything new on the list since
this email.