[Skiboot] [PATCH v3 4/6] doc/device-tree: Add documentation for ibm, cpu-idle-state-* properties

[Michael Neuling]

On Thu, 2016-06-02 at 14:20 +0530, Shreyas B. Prabhu wrote:
> Add documentation for following nodes-
> 	ibm,cpu-idle-state-pmicr ibm,cpu-idle-state-pmicr-mask
> 	ibm,cpu-idle-state-psscr ibm,cpu-idle-state-psscr-mask
> 	ibm,cpu-idle-state-flags
> 
> Also removing ibm,cpu-idle-state-names from FIXME since its
> already documented.
> 
> Signed-off-by: Shreyas B. Prabhu <shreyas at linux.vnet.ibm.com>

Acked-by: Michael Neuling <mikey at neuling.org>

> ---
>  doc/device-tree/ibm,opal/power-mgt.txt | 32 +++++++++++++++++++++++++++-
> ----
>  1 file changed, 27 insertions(+), 5 deletions(-)
> 
> diff --git a/doc/device-tree/ibm,opal/power-mgt.txt b/doc/device-
> tree/ibm,opal/power-mgt.txt
> index d9cadb87fdea..ca3487d492d8 100644
> --- a/doc/device-tree/ibm,opal/power-mgt.txt
> +++ b/doc/device-tree/ibm,opal/power-mgt.txt
> @@ -26,6 +26,33 @@ ibm,cpu-idle-state-residency-ns = <0x1 0x2 0x3>
>  ibm,cpu-idle-state-latencies-ns = <0x1 0x2 0x3>
>  
>  
> +ibm,cpu-idle-state-pmicr ibm,cpu-idle-state-pmicr-mask
> +------------------------------------------------------
> +In POWER8, idle states sleep and winkle have 2 modes- fast and deep. In
> fast
> +mode, idle state puts the core into threshold voltage whereas deep mode
> +completely turns off the core. Choosing fast vs deep mode for an idle
> state
> +can be done either via PM_GP1 scom or by writing to PMICR special
> register.
> +If using the PMICR path to choose fast/deep mode then ibm,cpu-idle-
> state-pmicr
> +and ibm,cpu-idle-state-pmicr-mask properties expose relevant PMICR bits
> and
> +values for corresponding idle states.
> +
> +
> +ibm,cpu-idle-state-psscr ibm,cpu-idle-state-psscr-mask
> +------------------------------------------------------
> +In POWER ISA v3, there is a common instruction 'stop' to enter any idle
> state
> +and SPR PSSCR is used to specify which idle state needs to be entered
> upon
> +executing stop instruction. Properties ibm,cpu-idle-state-psscr and
> +ibm,cpu-idle-state-psscr-mask expose the relevant PSSCR bits and values
> for
> +corresponding idle states.
> +
> +
> +ibm,cpu-idle-state-flags
> +------------------------
> +These flags are used to describe the characteristics of the idle states
> like
> +the kind of core state loss caused. These flags are used by the kernel
> to
> +save/restore appropriate context while using the idle states.
> +
> +
>  ibm,pstate-ids
>  --------------
>  
> @@ -67,8 +94,3 @@ ibm,pstate-core-max
>  This property is added when ultra_turbo(WOF) is enabled. This property
> gives
>  the list of max pstate for each 'n' number of active cores in the chip.
>  
> -FIXME: document these:
> -ibm,cpu-idle-state-flags
> -ibm,cpu-idle-state-names
> -ibm,cpu-idle-state-pmicr
> -ibm,cpu-idle-state-pmicr-mask