01.08.2019 0:10, Sowjanya Komatineni пишет:
> This patch implements DFLL suspend and resume operation.
>
> During system suspend entry, CPU clock will switch CPU to safe
> clock source of PLLP and disables DFLL clock output.
>
> DFLL driver suspend confirms DFLL disable state and errors out on
> being active.
>
> DFLL is re-initialized during the DFLL driver resume as it goes
> through complete reset during suspend entry.
>
> Signed-off-by: Sowjanya Komatineni <skomatineni@xxxxxxxxxx>
> ---
> drivers/clk/tegra/clk-dfll.c | 56 ++++++++++++++++++++++++++++++
> drivers/clk/tegra/clk-dfll.h | 2 ++
> drivers/clk/tegra/clk-tegra124-dfll-fcpu.c | 1 +
> 3 files changed, 59 insertions(+)
>
> diff --git a/drivers/clk/tegra/clk-dfll.c b/drivers/clk/tegra/clk-dfll.c
> index f8688c2ddf1a..9900097ec2aa 100644
> --- a/drivers/clk/tegra/clk-dfll.c
> +++ b/drivers/clk/tegra/clk-dfll.c
> @@ -1513,6 +1513,62 @@ static int dfll_init(struct tegra_dfll *td)
> return ret;
> }
>
> +/**
> + * tegra_dfll_suspend - check DFLL is disabled
> + * @dev: DFLL device *
> + *
> + * DFLL clock should be disabled by the CPUFreq driver. So, make
> + * sure it is disabled and disable all clocks needed by the DFLL.
> + */
> +int tegra_dfll_suspend(struct device *dev)
> +{
> + struct tegra_dfll *td = dev_get_drvdata(dev);
> +
> + if (dfll_is_running(td)) {
> + dev_err(td->dev, "dfll is enabled while shouldn't be\n");
> + return -EBUSY;
> + }
> +
> + reset_control_assert(td->dvco_rst);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(tegra_dfll_suspend);
> +
> +/**
> + * tegra_dfll_resume - reinitialize DFLL on resume
> + * @dev: DFLL instance
> + *
> + * DFLL is disabled and reset during suspend and resume.
> + * So, reinitialize the DFLL IP block back for use.
> + * DFLL clock is enabled later in closed loop mode by CPUFreq
> + * driver before switching its clock source to DFLL output.
> + */
> +int tegra_dfll_resume(struct device *dev)
> +{
> + struct tegra_dfll *td = dev_get_drvdata(dev);
> +
> + reset_control_deassert(td->dvco_rst);
> +
> + pm_runtime_irq_safe(td->dev);
Please see my previous reply.
