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

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On 8/9/19 9:23 AM, Sowjanya Komatineni wrote:

On 8/9/19 6:23 AM, Dmitry Osipenko wrote:
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@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.
POR value for these timing registers is not 0 and has default timings based on chip design and on top of that based on platform HW components charge/discharge timings there's a need to increase these timings so support for programming these thru DT is needed and these values have effect only in LP0.
  }
    static void tegra20_pmc_setup_irq_polarity(struct tegra_pmc *pmc,





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