Re: [PATCH 2/2] mmc: sdhci-of-at91: set clocks and presets after resume from deepest PM

From: Ludovic Desroches
Date: Tue Jun 20 2017 - 02:34:05 EST


On Fri, Jun 16, 2017 at 09:29:29AM +0200, Quentin Schulz wrote:
> This adds deepest (Backup+Self-Refresh) PM support to the ATMEL SAMA5D2
> SoC's SDHCI controller.
>
> When resuming from deepest state, it is required to restore preset
> registers as the registers are lost since VDD core has been shut down
> when entering deepest state on the SAMA5D2. The clocks need to be
> reconfigured as well.
>
> The other registers and init process are taken care of by the SDHCI
> core.
>
> Signed-off-by: Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxx>
Acked-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxxxxxx>
> ---
> drivers/mmc/host/sdhci-of-at91.c | 34 ++++++++++++++++++++++++++++++++--
> 1 file changed, 32 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c
> index fb8c6011f13d..300513fc1068 100644
> --- a/drivers/mmc/host/sdhci-of-at91.c
> +++ b/drivers/mmc/host/sdhci-of-at91.c
> @@ -207,6 +207,37 @@ static int sdhci_at91_set_clks_presets(struct device *dev)
> }
>
> #ifdef CONFIG_PM
> +static int sdhci_at91_suspend(struct device *dev)
> +{
> + struct sdhci_host *host = dev_get_drvdata(dev);
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
> + int ret;
> +
> + ret = sdhci_suspend_host(host);
> +
> + if (host->runtime_suspended)
> + return ret;
> +
> + clk_disable_unprepare(priv->gck);
> + clk_disable_unprepare(priv->hclock);
> + clk_disable_unprepare(priv->mainck);
> +
> + return ret;
> +}
> +
> +static int sdhci_at91_resume(struct device *dev)
> +{
> + struct sdhci_host *host = dev_get_drvdata(dev);
> + int ret;
> +
> + ret = sdhci_at91_set_clks_presets(dev);
> + if (ret)
> + return ret;
> +
> + return sdhci_resume_host(host);
> +}
> +
> static int sdhci_at91_runtime_suspend(struct device *dev)
> {
> struct sdhci_host *host = dev_get_drvdata(dev);
> @@ -256,8 +287,7 @@ static int sdhci_at91_runtime_resume(struct device *dev)
> #endif /* CONFIG_PM */
>
> static const struct dev_pm_ops sdhci_at91_dev_pm_ops = {
> - SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> - pm_runtime_force_resume)
> + SET_SYSTEM_SLEEP_PM_OPS(sdhci_at91_suspend, sdhci_at91_resume)
> SET_RUNTIME_PM_OPS(sdhci_at91_runtime_suspend,
> sdhci_at91_runtime_resume,
> NULL)
> --
> 2.11.0
>
> --
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