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

Dmitry Osipenko
2019-06-29T13:17:59Z

28.06.2019 5:12, Sowjanya Komatineni пишет:
> 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@nvidia.com>
> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
> ---
> 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() ?