Re: [PATCH v8 05/21] clk: tegra: pll: Save and restore pll context

From: Dmitry Osipenko
Date: Fri Aug 09 2019 - 07:33:25 EST


09.08.2019 2:46, Sowjanya Komatineni ÐÐÑÐÑ:
> This patch implements save and restore of PLL context.
>
> During system suspend, core power goes off and looses the settings
> of the Tegra CAR controller registers.
>
> So during suspend entry pll context is stored and on resume it is
> restored back along with its state.
>
> Acked-by: Thierry Reding <treding@xxxxxxxxxx>
> Signed-off-by: Sowjanya Komatineni <skomatineni@xxxxxxxxxx>
> ---
> drivers/clk/tegra/clk-pll.c | 88 ++++++++++++++++++++++++++++-----------------
> drivers/clk/tegra/clk.h | 2 ++
> 2 files changed, 58 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/clk/tegra/clk-pll.c b/drivers/clk/tegra/clk-pll.c
> index 1583f5fc992f..e52add2bbdbb 100644
> --- a/drivers/clk/tegra/clk-pll.c
> +++ b/drivers/clk/tegra/clk-pll.c
> @@ -1008,6 +1008,28 @@ static unsigned long clk_plle_recalc_rate(struct clk_hw *hw,
> return rate;
> }
>
> +static void tegra_clk_pll_restore_context(struct clk_hw *hw)
> +{
> + struct tegra_clk_pll *pll = to_clk_pll(hw);
> + struct clk_hw *parent = clk_hw_get_parent(hw);
> + unsigned long parent_rate = clk_hw_get_rate(parent);
> + unsigned long rate = clk_hw_get_rate(hw);
> + u32 val;
> +
> + if (clk_pll_is_enabled(hw))
> + return;
> +
> + if (pll->params->set_defaults)
> + pll->params->set_defaults(pll);
> +
> + clk_pll_set_rate(hw, rate, parent_rate);
> +
> + if (!__clk_get_enable_count(hw->clk))

What about orphaned clocks? Is enable_count > 0 for them?

> + clk_pll_disable(hw);
> + else
> + clk_pll_enable(hw);
> +}

[snip]