Re: [PATCH v4] thermal/drivers/tsens: Add suspend to RAM support for tsens

From: Priyansh Jain
Date: Wed Mar 27 2024 - 05:42:20 EST




On 3/26/2024 4:30 PM, Daniel Lezcano wrote:
On 26/03/2024 08:40, Priyansh Jain 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>
---
V3 -> V4: Make tsens_reinit function specific to tsens v2. Add
NULL resume callback support for platform whose versions < ver_2_x
in tsens ops.
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-v0_1.c |  6 +++++
  drivers/thermal/qcom/tsens-v1.c   |  3 +++
  drivers/thermal/qcom/tsens-v2.c   |  1 +
  drivers/thermal/qcom/tsens.c      | 37 +++++++++++++++++++++++++++++++
  drivers/thermal/qcom/tsens.h      |  5 +++++
  5 files changed, 52 insertions(+)

diff --git a/drivers/thermal/qcom/tsens-v0_1.c b/drivers/thermal/qcom/tsens-v0_1.c
index 32d2d3e33287..7ed85379247b 100644
--- a/drivers/thermal/qcom/tsens-v0_1.c
+++ b/drivers/thermal/qcom/tsens-v0_1.c
@@ -329,6 +329,7 @@ static const struct tsens_ops ops_8226 = {
      .init        = init_8226,
      .calibrate    = tsens_calibrate_common,
      .get_temp    = get_temp_common,
+    .resume        = NULL,

As a static variable it is already set to NULL. Why do you need to explicitly set them everywhere ?

It was asked in last version to explicitly add (.resume = NULL). So added this for all the tsens platforms for which resume callback is not
validated.

[ ... ]

+#ifdef CONFIG_SUSPEND
+static int tsens_reinit(struct tsens_priv *priv)
+{
+    unsigned long flags;
+
+    spin_lock_irqsave(&priv->ul_lock, flags);

What this lock is protecting ?

Yes this lock can be removed, will remove this in next patch.

+    if (tsens_version(priv) >= VER_2_X) {

May be move this test before the lock ?

+        /*
+         * 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 */
+        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 */