From 96048edcc740850823f4821cbe2524cffc7cf2ee Mon Sep 17 00:00:00 2001
From: Sudeep Holla <sudeep.holla@arm.com>
Date: Mon, 8 Jul 2019 09:41:01 +0100
Subject: [PATCH] UPSTREAM: firmware: arm_scmi: Add asynchronous sensor read if
 it supports

SENSOR_DESCRIPTION_GET provides attributes to indicate if the sensor
supports asynchronous read. We can read that flag and use asynchronous
reads for any sensors with that attribute set.

Let's use the new scmi_do_xfer_with_response to support asynchronous
sensor reads.

Change-Id: I8066cecb9565d5f40c42accbebc8ced2747d5dba
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Tao Huang <huangtao@rock-chips.com>
(cherry picked from commit d09aac0eb17c6ce2b66095e1e324f60ec9dd8988)
---
 drivers/firmware/arm_scmi/sensors.c | 30 +++++++++++++++++++++--------
 include/linux/scmi_protocol.h       |  2 ++
 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/drivers/firmware/arm_scmi/sensors.c b/drivers/firmware/arm_scmi/sensors.c
index 7e701fddd7d2..73cebecf8be6 100644
--- a/drivers/firmware/arm_scmi/sensors.c
+++ b/drivers/firmware/arm_scmi/sensors.c
@@ -136,9 +136,10 @@ static int scmi_sensor_description_get(const struct scmi_handle *handle,
 		}
 
 		for (cnt = 0; cnt < num_returned; cnt++) {
-			u32 attrh;
+			u32 attrh, attrl;
 			struct scmi_sensor_info *s;
 
+			attrl = le32_to_cpu(buf->desc[cnt].attributes_low);
 			attrh = le32_to_cpu(buf->desc[cnt].attributes_high);
 			s = &si->sensors[desc_index + cnt];
 			s->id = le32_to_cpu(buf->desc[cnt].id);
@@ -147,6 +148,8 @@ static int scmi_sensor_description_get(const struct scmi_handle *handle,
 			/* Sign extend to a full s8 */
 			if (s->scale & SENSOR_SCALE_SIGN)
 				s->scale |= SENSOR_SCALE_EXTEND;
+			s->async = SUPPORTS_ASYNC_READ(attrl);
+			s->num_trip_points = NUM_TRIP_POINTS(attrl);
 			strlcpy(s->name, buf->desc[cnt].name, SCMI_MAX_STR_SIZE);
 		}
 
@@ -214,8 +217,11 @@ static int scmi_sensor_reading_get(const struct scmi_handle *handle,
 				   u32 sensor_id, u64 *value)
 {
 	int ret;
+	__le32 *pval;
 	struct scmi_xfer *t;
 	struct scmi_msg_sensor_reading_get *sensor;
+	struct sensors_info *si = handle->sensor_priv;
+	struct scmi_sensor_info *s = si->sensors + sensor_id;
 
 	ret = scmi_xfer_get_init(handle, SENSOR_READING_GET,
 				 SCMI_PROTOCOL_SENSOR, sizeof(*sensor),
@@ -223,16 +229,24 @@ static int scmi_sensor_reading_get(const struct scmi_handle *handle,
 	if (ret)
 		return ret;
 
+	pval = t->rx.buf;
 	sensor = t->tx.buf;
 	sensor->id = cpu_to_le32(sensor_id);
-	sensor->flags = cpu_to_le32(0);
 
-	ret = scmi_do_xfer(handle, t);
-	if (!ret) {
-		__le32 *pval = t->rx.buf;
-
-		*value = le32_to_cpu(*pval);
-		*value |= (u64)le32_to_cpu(*(pval + 1)) << 32;
+	if (s->async) {
+		sensor->flags = cpu_to_le32(SENSOR_READ_ASYNC);
+		ret = scmi_do_xfer_with_response(handle, t);
+		if (!ret) {
+			*value = le32_to_cpu(*(pval + 1));
+			*value |= (u64)le32_to_cpu(*(pval + 2)) << 32;
+		}
+	} else {
+		sensor->flags = cpu_to_le32(0);
+		ret = scmi_do_xfer(handle, t);
+		if (!ret) {
+			*value = le32_to_cpu(*pval);
+			*value |= (u64)le32_to_cpu(*(pval + 1)) << 32;
+		}
 	}
 
 	scmi_xfer_put(handle, t);
diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index 83d72cc80b03..e60a307aabeb 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -145,6 +145,8 @@ struct scmi_sensor_info {
 	u32 id;
 	u8 type;
 	s8 scale;
+	u8 num_trip_points;
+	bool async;
 	char name[SCMI_MAX_STR_SIZE];
 };