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SubjectRe: [PATCH v8 19/21] soc/tegra: pmc: Configure deep sleep control settings
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09.08.2019 2:46, Sowjanya Komatineni пишет:
> 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@nvidia.com>
> ---
> 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.

> }
>
> static void tegra20_pmc_setup_irq_polarity(struct tegra_pmc *pmc,
>

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