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

[Priyansh Jain]

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,
 };
 
 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