Re: [PATCH v8 19/21] soc/tegra: pmc: Configure deep sleep control settings

[Sowjanya Komatineni]

On 8/9/19 6:23 AM, Dmitry Osipenko wrote:
> 09.08.2019 2:46, 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
> >    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>
> > ---
> >   drivers/soc/tegra/pmc.c | 13 ++++++++++++-
> >   1 file changed, 12 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
> > index e013ada7e4e9..9a78d8417367 100644
> > --- a/drivers/soc/tegra/pmc.c
> > +++ b/drivers/soc/tegra/pmc.c
> > @@ -88,6 +88,8 @@
> >   
> >   #define PMC_CPUPWRGOOD_TIMER		0xc8
> >   #define PMC_CPUPWROFF_TIMER		0xcc
> > +#define PMC_COREPWRGOOD_TIMER		0x3c
> > +#define PMC_COREPWROFF_TIMER		0xe0
> >   
> >   #define PMC_PWR_DET_VALUE		0xe4
> >   
> > @@ -2277,7 +2279,7 @@ static const struct tegra_pmc_regs tegra20_pmc_regs = {
> >   
> >   static void tegra20_pmc_init(struct tegra_pmc *pmc)
> >   {
> > -	u32 value;
> > +	u32 value, osc, pmu, off;
> >   
> >   	/* Always enable CPU power request */
> >   	value = tegra_pmc_readl(pmc, PMC_CNTRL);
> > @@ -2303,6 +2305,15 @@ static void tegra20_pmc_init(struct tegra_pmc *pmc)
> >   	value = tegra_pmc_readl(pmc, PMC_CNTRL);
> >   	value |= PMC_CNTRL_SYSCLK_OE;
> >   	tegra_pmc_writel(pmc, value, PMC_CNTRL);
> > +
> > +	osc = DIV_ROUND_UP(pmc->core_osc_time * 8192, 1000000);
> > +	pmu = DIV_ROUND_UP(pmc->core_pmu_time * 32768, 1000000);
> > +	off = DIV_ROUND_UP(pmc->core_off_time * 32768, 1000000);
> > +	if (osc && pmu)
> > +		tegra_pmc_writel(pmc, ((osc << 8) & 0xff00) | (pmu & 0xff),
> > +				 PMC_COREPWRGOOD_TIMER);
> > +	if (off)
> > +		tegra_pmc_writel(pmc, off, PMC_COREPWROFF_TIMER);
> The osc/pmu/off values are undefined if they are not defined in device-tree. I suppose this
> need to be corrected in tegra_pmc_parse_dt() if the values really matter even if LP0 suspend
> isn't supported in device-tree.
>
> And I'm also not sure what's wrong with setting 0 for the timers.
These settings are for SC7 only and will not have any impact in normal 
state.
> >   }
> >   
> >   static void tegra20_pmc_setup_irq_polarity(struct tegra_pmc *pmc,