[PATCH v4 1/2] firmware: arm_scmi: Fetch and store sensor scale

Florian Fainelli
2019-05-08T17:00:44Z

In preparation for dealing with scales within the SCMI HWMON driver,
fetch and store the sensor unit scale into the scmi_sensor_info
structure. In order to simplify computations for upper layer, take care
of sign extending the scale to a full 8-bit signed value.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
drivers/firmware/arm_scmi/sensors.c | 6 ++++++
include/linux/scmi_protocol.h | 1 +
2 files changed, 7 insertions(+)

diff --git a/drivers/firmware/arm_scmi/sensors.c b/drivers/firmware/arm_scmi/sensors.c
index b53d5cc9c9f6..21353470a740 100644
--- a/drivers/firmware/arm_scmi/sensors.c
+++ b/drivers/firmware/arm_scmi/sensors.c
@@ -34,6 +34,8 @@ struct scmi_msg_resp_sensor_description {
__le32 attributes_high;
#define SENSOR_TYPE(x) ((x) & 0xff)
#define SENSOR_SCALE(x) (((x) >> 11) & 0x3f)
+#define SENSOR_SCALE_SIGN BIT(5)
+#define SENSOR_SCALE_EXTEND GENMASK(7, 6)
#define SENSOR_UPDATE_SCALE(x) (((x) >> 22) & 0x1f)
#define SENSOR_UPDATE_BASE(x) (((x) >> 27) & 0x1f)
u8 name[SCMI_MAX_STR_SIZE];
@@ -140,6 +142,10 @@ static int scmi_sensor_description_get(const struct scmi_handle *handle,
s = &si->sensors[desc_index + cnt];
s->id = le32_to_cpu(buf->desc[cnt].id);
s->type = SENSOR_TYPE(attrh);
+ s->scale = SENSOR_SCALE(attrh);
+ /* Sign extend to a full s8 */
+ if (s->scale & SENSOR_SCALE_SIGN)
+ s->scale |= SENSOR_SCALE_EXTEND;
strlcpy(s->name, buf->desc[cnt].name, SCMI_MAX_STR_SIZE);
}

diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index 3105055c00a7..9ff2e9357e9a 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -144,6 +144,7 @@ struct scmi_power_ops {
struct scmi_sensor_info {
u32 id;
u8 type;
+ s8 scale;
char name[SCMI_MAX_STR_SIZE];
};

--
2.17.1