Re: [PATCH v3] thermal/drivers/tsens: Add suspend to RAM support for tsens

[Amit Kucheria]

On Tue, Feb 27, 2024 at 9:40 PM Priyansh Jain <quic_priyjain@xxxxxxxxxxx> wrote:
>
> As part of suspend to RAM, tsens hardware will be turned off.
> While resume callback, re-initialize tsens hardware.
>
> Signed-off-by: Priyansh Jain <quic_priyjain@xxxxxxxxxxx>
> ---
> V2 -> V3: Remove suspend callback & interrupt enablement part from
> resume callback.
> V1 -> V2: Update commit text to explain the necessity of this patch
>
>  drivers/thermal/qcom/tsens-v2.c |  1 +
>  drivers/thermal/qcom/tsens.c    | 40 +++++++++++++++++++++++++++++++++
>  drivers/thermal/qcom/tsens.h    |  6 +++++
>  3 files changed, 47 insertions(+)
>
> diff --git a/drivers/thermal/qcom/tsens-v2.c b/drivers/thermal/qcom/tsens-v2.c
> index 29a61d2d6ca3..0cb7301eca6e 100644
> --- a/drivers/thermal/qcom/tsens-v2.c
> +++ b/drivers/thermal/qcom/tsens-v2.c
> @@ -107,6 +107,7 @@ static const struct reg_field tsens_v2_regfields[MAX_REGFIELDS] = {
>  static const struct tsens_ops ops_generic_v2 = {
>         .init           = init_common,
>         .get_temp       = get_temp_tsens_valid,
> +       .resume         = tsens_resume_common,
>  };

Please add resume callbacks for the other tsens hardware too and make
sure that your reinit function handles them too.

>
>  struct tsens_plat_data data_tsens_v2 = {
> diff --git a/drivers/thermal/qcom/tsens.c b/drivers/thermal/qcom/tsens.c
> index 6d7c16ccb44d..396c1cd71351 100644
> --- a/drivers/thermal/qcom/tsens.c
> +++ b/drivers/thermal/qcom/tsens.c
> @@ -17,6 +17,7 @@
>  #include <linux/pm.h>
>  #include <linux/regmap.h>
>  #include <linux/slab.h>
> +#include <linux/suspend.h>
>  #include <linux/thermal.h>
>  #include "../thermal_hwmon.h"
>  #include "tsens.h"
> @@ -1193,6 +1194,45 @@ static int tsens_register_irq(struct tsens_priv *priv, char *irqname,
>         return ret;
>  }
>
> +#ifdef CONFIG_SUSPEND
> +static int tsens_reinit(struct tsens_priv *priv)
> +{
> +       unsigned long flags;
> +
> +       spin_lock_irqsave(&priv->ul_lock, flags);
> +
> +       /* in VER_0 TSENS need to be explicitly enabled */
> +       if (tsens_version(priv) == VER_0)
> +               regmap_field_write(priv->rf[TSENS_EN], 1);
> +
> +       /*
> +        * Re-enable the watchdog, unmask the bark.
> +        * Disable cycle completion monitoring
> +        */
> +       if (priv->feat->has_watchdog) {
> +               regmap_field_write(priv->rf[WDOG_BARK_MASK], 0);
> +               regmap_field_write(priv->rf[CC_MON_MASK], 1);
> +       }
> +
> +       /* Re-enable interrupts */
> +       if (tsens_version(priv) >= VER_0_1)
> +               tsens_enable_irq(priv);
> +
> +       spin_unlock_irqrestore(&priv->ul_lock, flags);
> +
> +       return 0;
> +}
> +
> +int tsens_resume_common(struct tsens_priv *priv)
> +{
> +       if (pm_suspend_target_state == PM_SUSPEND_MEM)
> +               tsens_reinit(priv);
> +
> +       return 0;
> +}
> +
> +#endif /* !CONFIG_SUSPEND */
> +
>  static int tsens_register(struct tsens_priv *priv)
>  {
>         int i, ret;
> diff --git a/drivers/thermal/qcom/tsens.h b/drivers/thermal/qcom/tsens.h
> index cb637fa289ca..7a147d9d8544 100644
> --- a/drivers/thermal/qcom/tsens.h
> +++ b/drivers/thermal/qcom/tsens.h
> @@ -635,6 +635,12 @@ int init_common(struct tsens_priv *priv);
>  int get_temp_tsens_valid(const struct tsens_sensor *s, int *temp);
>  int get_temp_common(const struct tsens_sensor *s, int *temp);
>
> +#ifdef CONFIG_SUSPEND
> +int tsens_resume_common(struct tsens_priv *priv);
> +#else
> +#define tsens_resume_common            NULL
> +#endif
> +
>  /* TSENS target */
>  extern struct tsens_plat_data data_8960;
>
> --
> 2.17.1
>