[PATCH v3 2/3] drivers: qcom: rpmh-rsc: return if the controller is idle

[Raju P.L.S.S.S.N]

From: Lina Iyer <ilina@xxxxxxxxxxxxxx>

Allow the controller status be queried. The controller is busy if it is
actively processing request. Also allow the controller state be read by
platform drivers. This is useful for PM drivers which can choose to
disallow idle modes when the controller is busy.

Signed-off-by: Lina Iyer <ilina@xxxxxxxxxxxxxx>
Signed-off-by: Raju P.L.S.S.S.N <rplsssn@xxxxxxxxxxxxxx>
---
changes in v3
- Add lock check to avoid potential race as suggested by Matthias
---
 drivers/soc/qcom/rpmh-internal.h |  1 +
 drivers/soc/qcom/rpmh-rsc.c      | 24 ++++++++++++++++++++++++
 drivers/soc/qcom/rpmh.c          | 13 +++++++++++++
 include/soc/qcom/rpmh.h          |  5 +++++
 4 files changed, 43 insertions(+)

diff --git a/drivers/soc/qcom/rpmh-internal.h b/drivers/soc/qcom/rpmh-internal.h
index 2e3ffcd..4b891c23 100644
--- a/drivers/soc/qcom/rpmh-internal.h
+++ b/drivers/soc/qcom/rpmh-internal.h
@@ -109,6 +109,7 @@ int rpmh_rsc_write_ctrl_data(struct rsc_drv *drv,
 			     const struct tcs_request *msg);
 int rpmh_rsc_invalidate(struct rsc_drv *drv);
 int rpmh_rsc_write_pdc_data(struct rsc_drv *drv, const struct tcs_request *msg);
+bool rpmh_rsc_ctrlr_is_idle(struct rsc_drv *drv);
 void rpmh_tx_done(const struct tcs_request *msg, int r);
 
 #endif /* __RPM_INTERNAL_H__ */
diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c
index d6b834e..9cc303e 100644
--- a/drivers/soc/qcom/rpmh-rsc.c
+++ b/drivers/soc/qcom/rpmh-rsc.c
@@ -525,6 +525,30 @@ static int tcs_ctrl_write(struct rsc_drv *drv, const struct tcs_request *msg)
 }
 
 /**
+ *  rpmh_rsc_ctrlr_is_idle: Check if any of the AMCs are busy.
+ *
+ *  @drv: The controller
+ *
+ *  Returns true if the TCSes are engaged in handling requests.
+ */
+bool rpmh_rsc_ctrlr_is_idle(struct rsc_drv *drv)
+{
+	int m;
+	struct tcs_group *tcs = get_tcs_of_type(drv, ACTIVE_TCS);
+
+	spin_lock(&drv->lock);
+	for (m = tcs->offset; m < tcs->offset + tcs->num_tcs; m++) {
+		if (!tcs_is_free(drv, m)) {
+			spin_unlock(&drv->lock);
+			return false;
+		}
+	}
+	spin_unlock(&drv->lock);
+
+	return true;
+}
+
+/**
  * rpmh_rsc_write_ctrl_data: Write request to the controller
  *
  * @drv: the controller
diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c
index 297d6cc..43eb981 100644
--- a/drivers/soc/qcom/rpmh.c
+++ b/drivers/soc/qcom/rpmh.c
@@ -535,3 +535,16 @@ int rpmh_invalidate(const struct device *dev)
 	return ret;
 }
 EXPORT_SYMBOL(rpmh_invalidate);
+
+/**
+ * rpmh_ctrlr_idle: Return the controller idle status
+ *
+ * @dev: the device making the request
+ */
+int rpmh_ctrlr_idle(const struct device *dev)
+{
+	struct rpmh_ctrlr *ctrlr = get_rpmh_ctrlr(dev);
+
+	return rpmh_rsc_ctrlr_is_idle(ctrlr_to_drv(ctrlr));
+}
+EXPORT_SYMBOL(rpmh_ctrlr_idle);
diff --git a/include/soc/qcom/rpmh.h b/include/soc/qcom/rpmh.h
index b05e31a..4c4b013 100644
--- a/include/soc/qcom/rpmh.h
+++ b/include/soc/qcom/rpmh.h
@@ -27,6 +27,8 @@ int rpmh_write_batch(const struct device *dev, enum rpmh_state state,
 int rpmh_write_pdc_data(const struct device *dev,
 			const struct tcs_cmd *cmd, u32 n);
 
+int rpmh_ctrlr_idle(const struct device *dev);
+
 #else
 
 static inline int rpmh_write(const struct device *dev, enum rpmh_state state,
@@ -53,6 +55,9 @@ static inline int rpmh_write_pdc_data(const struct device *dev,
 				      const struct tcs_cmd *cmd, u32 n)
 { return -ENODEV; }
 
+static inline int rpmh_ctrlr_idle(const struct device *dev)
+{ return -ENODEV; }
+
 #endif /* CONFIG_QCOM_RPMH */
 
 #endif /* __SOC_QCOM_RPMH_H__ */
-- 
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