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

Message ID 1464857449-12627-5-git-send-email-shreyas@linux.vnet.ibm.com
State Changes Requested
Headers show

Commit Message

Shreyas B. Prabhu June 2, 2016, 8:50 a.m. UTC
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@linux.vnet.ibm.com>
---
 doc/device-tree/ibm,opal/power-mgt.txt | 32 +++++++++++++++++++++++++++-----
 1 file changed, 27 insertions(+), 5 deletions(-)

Comments

Michael Neuling June 6, 2016, 6:02 a.m. UTC | #1
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@linux.vnet.ibm.com>

Acked-by: Michael Neuling <mikey@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
diff mbox

Patch

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