Re: [PATCH V5 09/18] clk: tegra: Add save and restore context support for peripheral clocks

[Dmitry Osipenko]

28.06.2019 5:12, Sowjanya Komatineni ÐÐÑÐÑ:
> This patch implements save and restore context for peripheral fixed
> clock ops, peripheral gate clock ops, sdmmc mux clock ops, and
> peripheral clock ops.
> 
> During system suspend, core power goes off and looses the settings
> of the Tegra CAR controller registers.
> 
> So during suspend entry clock and reset state of peripherals is saved
> and on resume they are restored to have clocks back to same rate and
> state as before suspend.
> 
> Acked-by: Thierry Reding <treding@xxxxxxxxxx>
> Signed-off-by: Sowjanya Komatineni <skomatineni@xxxxxxxxxx>
> ---
>  drivers/clk/tegra/clk-periph-fixed.c | 31 ++++++++++++++++++++++++++
>  drivers/clk/tegra/clk-periph-gate.c  | 34 ++++++++++++++++++++++++++++
>  drivers/clk/tegra/clk-periph.c       | 43 ++++++++++++++++++++++++++++++++++++
>  drivers/clk/tegra/clk-sdmmc-mux.c    | 30 +++++++++++++++++++++++++
>  drivers/clk/tegra/clk.h              |  8 +++++++
>  5 files changed, 146 insertions(+)
> 
> diff --git a/drivers/clk/tegra/clk-periph-fixed.c b/drivers/clk/tegra/clk-periph-fixed.c
> index c088e7a280df..981f68b0a937 100644
> --- a/drivers/clk/tegra/clk-periph-fixed.c
> +++ b/drivers/clk/tegra/clk-periph-fixed.c
> @@ -60,11 +60,42 @@ tegra_clk_periph_fixed_recalc_rate(struct clk_hw *hw,
>  	return (unsigned long)rate;
>  }
>  
> +static int tegra_clk_periph_fixed_save_context(struct clk_hw *hw)
> +{
> +	struct tegra_clk_periph_fixed *fixed = to_tegra_clk_periph_fixed(hw);
> +	u32 mask = 1 << (fixed->num % 32);
> +
> +	fixed->enb_ctx = readl(fixed->base + fixed->regs->enb_reg) & mask;
> +	fixed->rst_ctx = readl(fixed->base + fixed->regs->rst_reg) & mask;
> +

readl_relaxed() ?