Re: [PATCH v9 20/22] soc/tegra: pmc: Configure deep sleep control settings

[Sowjanya Komatineni]

On 8/19/19 11:20 AM, Sowjanya Komatineni wrote:
> On 8/19/19 9:48 AM, Dmitry Osipenko wrote:
> > 16.08.2019 22:42, Sowjanya Komatineni ÐÐÑÐÑ:
> > > Tegra210 and prior Tegra chips have deep sleep entry and wakeup related
> > > timings which are platform specific that should be configured before
> > > entering into deep sleep.
> > >
> > > Below are the timing specific configurations for deep sleep entry and
> > > wakeup.
> > > - Core rail power-on stabilization timer
> > > - OSC clock stabilization timer after SOC rail power is stabilized.
> > > - Core power off time is the minimum wake delay to keep the system
> > > ÂÂ in deep sleep state irrespective of any quick wake event.
> > >
> > > These values depends on the discharge time of regulators and turn OFF
> > > time of the PMIC to allow the complete system to finish entering into
> > > deep sleep state.
> > >
> > > These values vary based on the platform design and are specified
> > > through the device tree.
> > >
> > > This patch has implementation to configure these timings which are must
> > > to have for proper deep sleep and wakeup operations.
> > >
> > > Signed-off-by: Sowjanya Komatineni <skomatineni@xxxxxxxxxx>
> > > ---
> > > Â drivers/soc/tegra/pmc.c | 14 +++++++++++++-
> > > Â 1 file changed, 13 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
> > > index 53ed70773872..710969043668 100644
> > > --- a/drivers/soc/tegra/pmc.c
> > > +++ b/drivers/soc/tegra/pmc.c
> > > @@ -88,6 +88,8 @@
> > > Â Â #define PMC_CPUPWRGOOD_TIMERÂÂÂÂÂÂÂ 0xc8
> > > Â #define PMC_CPUPWROFF_TIMERÂÂÂÂÂÂÂ 0xcc
> > > +#define PMC_COREPWRGOOD_TIMERÂÂÂÂÂÂÂ 0x3c
> > > +#define PMC_COREPWROFF_TIMERÂÂÂÂÂÂÂ 0xe0
> > > Â Â #define PMC_PWR_DET_VALUEÂÂÂÂÂÂÂ 0xe4
> > > Â @@ -2277,7 +2279,7 @@ static const struct tegra_pmc_regs 
> > > tegra20_pmc_regs = {
> > > Â Â static void tegra20_pmc_init(struct tegra_pmc *pmc)
> > > Â {
> > > -ÂÂÂ u32 value;
> > > +ÂÂÂ u32 value, osc, pmu, off;
> > > Â ÂÂÂÂÂ /* Always enable CPU power request */
> > > ÂÂÂÂÂ value = tegra_pmc_readl(pmc, PMC_CNTRL);
> > > @@ -2303,6 +2305,16 @@ static void tegra20_pmc_init(struct tegra_pmc 
> > > *pmc)
> > > ÂÂÂÂÂ value = tegra_pmc_readl(pmc, PMC_CNTRL);
> > > ÂÂÂÂÂ value |= PMC_CNTRL_SYSCLK_OE;
> > > ÂÂÂÂÂ tegra_pmc_writel(pmc, value, PMC_CNTRL);
> > > +
> > > +ÂÂÂ /* program core timings which are applicable only for suspend 
> > > state */
> > > +ÂÂÂ if (pmc->suspend_mode != TEGRA_SUSPEND_NONE) {
> > > +ÂÂÂÂÂÂÂ osc = DIV_ROUND_UP(pmc->core_osc_time * 8192, 1000000);
> > > +ÂÂÂÂÂÂÂ pmu = DIV_ROUND_UP(pmc->core_pmu_time * 32768, 1000000);
> > > +ÂÂÂÂÂÂÂ off = DIV_ROUND_UP(pmc->core_off_time * 32768, 1000000);
> > > +ÂÂÂÂÂÂÂ tegra_pmc_writel(pmc, ((osc << 8) & 0xff00) | (pmu & 0xff),
> > > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ PMC_COREPWRGOOD_TIMER);
> > > +ÂÂÂÂÂÂÂ tegra_pmc_writel(pmc, off, PMC_COREPWROFF_TIMER);
> > > +ÂÂÂ }
> > > Â }
> > > Â Â static void tegra20_pmc_setup_irq_polarity(struct tegra_pmc *pmc,
> > In the previous version of this patch there were checks for zero values
> > of the timers with intention to skip programming of the timers if value
> > is zero. I'm a bit puzzled by the new version, given that SUSPEND_NONE
> > means that suspending isn't available at all and thus PMC timers won't
> > be utilized, hence it shouldn't matter what values are programmed for
> > the counters, isn't it?
>
> Yes, as I see in documentation we already specify all these timings 
> are required properties when suspend mode is used, I updated in this 
> version to program core timings only when suspend mode is enabled.
In other words, core timings are for SC7 entry only. So when SC7/suspend 
mode is not used, these timings doesn't matter.