Re: [PATCHv5 03/14] arm: omap3+: voltage: parameter segregation
On Thu, Feb 23, 2012 at 03:08, Tero Kristo t-kri...@ti.com wrote: On Wed, 2012-02-22 at 19:37 -0600, Menon, Nishanth wrote: On Tue, Feb 21, 2012 at 08:04, Tero Kristo t-kri...@ti.com wrote: [...] diff --git a/arch/arm/mach-omap2/voltage.h b/arch/arm/mach-omap2/voltage.h index 949938d..940a0d6 100644 --- a/arch/arm/mach-omap2/voltage.h +++ b/arch/arm/mach-omap2/voltage.h [...] @@ -171,6 +169,18 @@ struct omap_voltdm_pmic { u8 (*uv_to_vsel) (unsigned long uV); }; +struct omap_vp_param { + u32 vddmax; + u32 vddmin; +}; + Thinking a little deeper about this(SoC level vdd min and max) on a slightly different angle- core of the question that intend to answer are: - what is the least voltage we want to allow in active transtion? it should not be lower than retention voltage. I think this is a fair assumption, so we could init the vddmin to be the same as the retention voltage for the domain (or even drop the parameter.) - what is the max voltage we want to allow in active transition? it should be the max Nom voltage of all the OPPs for that domain. Isn't it higher? I guess smartreflex can scale voltages even up from the nominal level if we have a really old and/or bad silicon. Limiting this to max opp would be bad, no? Maybe we could use max opp voltage + some margin though... but what would be a safe margin here? Vnom voltage definition tends to be a variant - yep. at least OMAP3,4 have intended to have Vnom as the max voltage for the worst corner lot sample at end of life - aka worst possible voltage for that OPP. But with newer process technologies of the future SoCs, this definition might turn out to become the start voltage. OK, it is safer to have vnom max at max SoC supported voltage i guess to prevent code churn in the future and maintain compatibility with current SoCs. Regards, Nishanth Menon -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCHv5 03/14] arm: omap3+: voltage: parameter segregation
On Wed, 2012-02-22 at 19:37 -0600, Menon, Nishanth wrote: On Tue, Feb 21, 2012 at 08:04, Tero Kristo t-kri...@ti.com wrote: [...] diff --git a/arch/arm/mach-omap2/voltage.h b/arch/arm/mach-omap2/voltage.h index 949938d..940a0d6 100644 --- a/arch/arm/mach-omap2/voltage.h +++ b/arch/arm/mach-omap2/voltage.h [...] @@ -171,6 +169,18 @@ struct omap_voltdm_pmic { u8 (*uv_to_vsel) (unsigned long uV); }; +struct omap_vp_param { + u32 vddmax; + u32 vddmin; +}; + Thinking a little deeper about this(SoC level vdd min and max) on a slightly different angle- core of the question that intend to answer are: - what is the least voltage we want to allow in active transtion? it should not be lower than retention voltage. I think this is a fair assumption, so we could init the vddmin to be the same as the retention voltage for the domain (or even drop the parameter.) - what is the max voltage we want to allow in active transition? it should be the max Nom voltage of all the OPPs for that domain. Isn't it higher? I guess smartreflex can scale voltages even up from the nominal level if we have a really old and/or bad silicon. Limiting this to max opp would be bad, no? Maybe we could use max opp voltage + some margin though... but what would be a safe margin here? In effect, why do we even need to register voltdm-vp_param-vdd[min|max]? We already have that info - right? On the other hand it might be safer to do this way to handle quirks in future SoCs.. but thought I'd spit it out anyways.. +struct omap_vc_param { and elsewhere - please add kernel-doc struct documentation as well when new structs are introduced? Yea, I can add those for next version. + u32 on; + u32 onlp; + u32 ret; + u32 off; +}; + [...] Regards, Nishanth Menon -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCHv5 03/14] arm: omap3+: voltage: parameter segregation
On Tue, Feb 21, 2012 at 08:04, Tero Kristo t-kri...@ti.com wrote: [...] diff --git a/arch/arm/mach-omap2/voltage.h b/arch/arm/mach-omap2/voltage.h index 949938d..940a0d6 100644 --- a/arch/arm/mach-omap2/voltage.h +++ b/arch/arm/mach-omap2/voltage.h [...] @@ -171,6 +169,18 @@ struct omap_voltdm_pmic { u8 (*uv_to_vsel) (unsigned long uV); }; +struct omap_vp_param { + u32 vddmax; + u32 vddmin; +}; + Thinking a little deeper about this(SoC level vdd min and max) on a slightly different angle- core of the question that intend to answer are: - what is the least voltage we want to allow in active transtion? it should not be lower than retention voltage. - what is the max voltage we want to allow in active transition? it should be the max Nom voltage of all the OPPs for that domain. In effect, why do we even need to register voltdm-vp_param-vdd[min|max]? We already have that info - right? On the other hand it might be safer to do this way to handle quirks in future SoCs.. but thought I'd spit it out anyways.. +struct omap_vc_param { and elsewhere - please add kernel-doc struct documentation as well when new structs are introduced? + u32 on; + u32 onlp; + u32 ret; + u32 off; +}; + [...] Regards, Nishanth Menon -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html