From: Ivor Wanders <ivor@xxxxxxxxxxxx>
The thermal subsystem of the Surface Aggregator Module allows us to
query the names of the respective thermal sensors. Forward those to
userspace.
Signed-off-by: Ivor Wanders <ivor@xxxxxxxxxxxx>
Co-developed-by: Maximilian Luz <luzmaximilian@xxxxxxxxx>
Signed-off-by: Maximilian Luz <luzmaximilian@xxxxxxxxx>
---
drivers/hwmon/surface_temp.c | 112 +++++++++++++++++++++++++++++------
1 file changed, 95 insertions(+), 17 deletions(-)
diff --git a/drivers/hwmon/surface_temp.c b/drivers/hwmon/surface_temp.c
index 48c3e826713f6..7a2e1f638336c 100644
--- a/drivers/hwmon/surface_temp.c
+++ b/drivers/hwmon/surface_temp.c
@@ -17,6 +17,27 @@
/* -- SAM interface. -------------------------------------------------------- */
+/*
+ * Available sensors are indicated by a 16-bit bitfield, where a 1 marks the
+ * presence of a sensor. So we have at most 16 possible sensors/channels.
+ */
+#define SSAM_TMP_SENSOR_MAX_COUNT 16
+
+/*
+ * All names observed so far are 6 characters long, but there's only
+ * zeros after the name, so perhaps they can be longer. This number reflects
+ * the maximum zero-padded space observed in the returned buffer.
+ */
+#define SSAM_TMP_SENSOR_NAME_LENGTH 18
+
+struct ssam_tmp_get_name_rsp {
+ __le16 unknown1;
+ char unknown2;
+ char name[SSAM_TMP_SENSOR_NAME_LENGTH];
+} __packed;
+
+static_assert(sizeof(struct ssam_tmp_get_name_rsp) == 21);
+
SSAM_DEFINE_SYNC_REQUEST_CL_R(__ssam_tmp_get_available_sensors, __le16, {
.target_category = SSAM_SSH_TC_TMP,
.command_id = 0x04,
@@ -27,6 +48,11 @@ SSAM_DEFINE_SYNC_REQUEST_MD_R(__ssam_tmp_get_temperature, __le16, {
.command_id = 0x01,
});
+SSAM_DEFINE_SYNC_REQUEST_MD_R(__ssam_tmp_get_name, struct ssam_tmp_get_name_rsp, {
+ .target_category = SSAM_SSH_TC_TMP,
+ .command_id = 0x0e,
+});
+
static int ssam_tmp_get_available_sensors(struct ssam_device *sdev, s16 *sensors)
{
__le16 sensors_le;
@@ -54,12 +80,37 @@ static int ssam_tmp_get_temperature(struct ssam_device *sdev, u8 iid, long *temp
return 0;
}
+static int ssam_tmp_get_name(struct ssam_device *sdev, u8 iid, char *buf, size_t buf_len)
+{
+ struct ssam_tmp_get_name_rsp name_rsp;
+ int status;
+
+ status = __ssam_tmp_get_name(sdev->ctrl, sdev->uid.target, iid, &name_rsp);
+ if (status)
+ return status;
+
+ /*
+ * This should not fail unless the name in the returned struct is not
+ * null-terminated or someone changed something in the struct
+ * definitions above, since our buffer and struct have the same
+ * capacity by design. So if this fails blow this up with a warning.
+ * Since the more likely cause is that the returned string isn't
+ * null-terminated, we might have received garbage (as opposed to just
+ * an incomplete string), so also fail the function.
+ */
+ status = strscpy(buf, name_rsp.name, buf_len);
+ WARN_ON(status < 0);
+
+ return status < 0 ? status : 0;
+}
+
/* -- Driver.---------------------------------------------------------------- */
struct ssam_temp {
struct ssam_device *sdev;
s16 sensors;
+ char names[SSAM_TMP_SENSOR_MAX_COUNT][SSAM_TMP_SENSOR_NAME_LENGTH];
};
static umode_t ssam_temp_hwmon_is_visible(const void *data,
@@ -83,33 +134,47 @@ static int ssam_temp_hwmon_read(struct device *dev,
return ssam_tmp_get_temperature(ssam_temp->sdev, channel + 1, value);
}
+static int ssam_temp_hwmon_read_string(struct device *dev,
+ enum hwmon_sensor_types type,
+ u32 attr, int channel, const char **str)
+{
+ const struct ssam_temp *ssam_temp = dev_get_drvdata(dev);
+
+ *str = ssam_temp->names[channel];
+ return 0;
+}
+
static const struct hwmon_channel_info * const ssam_temp_hwmon_info[] = {
HWMON_CHANNEL_INFO(chip,
HWMON_C_REGISTER_TZ),
- /* We have at most 16 thermal sensor channels. */
+ /*
+ * We have at most SSAM_TMP_SENSOR_MAX_COUNT = 16 thermal sensor
+ * channels.
+ */
HWMON_CHANNEL_INFO(temp,
- HWMON_T_INPUT,
- HWMON_T_INPUT,
- HWMON_T_INPUT,
- HWMON_T_INPUT,
- HWMON_T_INPUT,
- HWMON_T_INPUT,
- HWMON_T_INPUT,
- HWMON_T_INPUT,
- HWMON_T_INPUT,
- HWMON_T_INPUT,
- HWMON_T_INPUT,
- HWMON_T_INPUT,
- HWMON_T_INPUT,
- HWMON_T_INPUT,
- HWMON_T_INPUT,
- HWMON_T_INPUT),
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL),
NULL
};
static const struct hwmon_ops ssam_temp_hwmon_ops = {
.is_visible = ssam_temp_hwmon_is_visible,
.read = ssam_temp_hwmon_read,
+ .read_string = ssam_temp_hwmon_read_string,
};
static const struct hwmon_chip_info ssam_temp_hwmon_chip_info = {
@@ -122,6 +187,7 @@ static int ssam_temp_probe(struct ssam_device *sdev)
struct ssam_temp *ssam_temp;
struct device *hwmon_dev;
s16 sensors;
+ int channel;
int status;
status = ssam_tmp_get_available_sensors(sdev, &sensors);
@@ -135,6 +201,18 @@ static int ssam_temp_probe(struct ssam_device *sdev)
ssam_temp->sdev = sdev;
ssam_temp->sensors = sensors;
+ /* Retrieve the name for each available sensor. */
+ for (channel = 0; channel < SSAM_TMP_SENSOR_MAX_COUNT; channel++) {
+ if (!(sensors & BIT(channel)))
+ continue;
+
+ status = ssam_tmp_get_name(sdev, channel + 1,
+ ssam_temp->names[channel],
+ SSAM_TMP_SENSOR_NAME_LENGTH);
+ if (status)
+ return status;
+ }
+
hwmon_dev = devm_hwmon_device_register_with_info(&sdev->dev,
"surface_thermal", ssam_temp, &ssam_temp_hwmon_chip_info,
NULL);
--
2.44.0
