[PATCH v2 14/15] drivers: thermal: tsens: Create function to return sign-extended temperature

Amit Kucheria
2019-08-27T12:15:35Z

Hide the details of how to convert values read from TSENS HW to mCelsius
behind a function. All versions of the IP can be supported as a result.

Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
---
drivers/thermal/qcom/tsens-common.c | 50 +++++++++++++++++++++--------
drivers/thermal/qcom/tsens.h | 2 ++
2 files changed, 38 insertions(+), 14 deletions(-)

diff --git a/drivers/thermal/qcom/tsens-common.c b/drivers/thermal/qcom/tsens-common.c
index ea2c46cc6a66a..06b44cfd5eab9 100644
--- a/drivers/thermal/qcom/tsens-common.c
+++ b/drivers/thermal/qcom/tsens-common.c
@@ -84,13 +84,43 @@ static inline int code_to_degc(u32 adc_code, const struct tsens_sensor *s)
return degc;
}

+/**
+ * tsens_hw_to_mC - Return sign-extended temperature in mCelsius.
+ * @s: Pointer to sensor struct
+ * @field: Index into regmap_field array pointing to temperature data
+ *
+ * This function handles temperature returned in ADC code or deciCelsius
+ * depending on IP version.
+ *
+ * Return: Temperature in milliCelsius on success, a negative errno will
+ * be returned in error cases
+ */
+static int tsens_hw_to_mC(struct tsens_sensor *s, int field)
+{
+ struct tsens_priv *priv = s->priv;
+ u32 temp = 0;
+ int ret;
+
+ ret = regmap_field_read(priv->rf[field], &temp);
+ if (ret)
+ return ret;
+
+ if (priv->feat->adc) {
+ /* Convert temperature from ADC code to milliCelsius */
+ return code_to_degc(temp, s) * 1000;
+ }
+
+ /* deciCelsius -> milliCelsius along with sign extension */
+ return sign_extend32(temp, priv->tempres) * 100;
+}
+
int get_temp_tsens_valid(struct tsens_sensor *s, int *temp)
{
struct tsens_priv *priv = s->priv;
int hw_id = s->hw_id;
u32 temp_idx = LAST_TEMP_0 + hw_id;
u32 valid_idx = VALID_0 + hw_id;
- u32 last_temp = 0, valid, mask;
+ u32 valid;
int ret;

ret = regmap_field_read(priv->rf[valid_idx], &valid);
@@ -108,19 +138,7 @@ int get_temp_tsens_valid(struct tsens_sensor *s, int *temp)
}

/* Valid bit is set, OK to read the temperature */
- ret = regmap_field_read(priv->rf[temp_idx], &last_temp);
- if (ret)
- return ret;
-
- if (priv->feat->adc) {
- /* Convert temperature from ADC code to milliCelsius */
- *temp = code_to_degc(last_temp, s) * 1000;
- } else {
- mask = GENMASK(priv->fields[LAST_TEMP_0].msb,
- priv->fields[LAST_TEMP_0].lsb);
- /* Convert temperature from deciCelsius to milliCelsius */
- *temp = sign_extend32(last_temp, fls(mask) - 1) * 100;
- }
+ *temp = tsens_hw_to_mC(s, temp_idx);

return 0;
}
@@ -310,6 +328,10 @@ int __init init_common(struct tsens_priv *priv)
goto err_put_device;
}
}
+
+ /* Save away resolution of signed temperature value for this IP */
+ priv->tempres = priv->fields[LAST_TEMP_0].msb - priv->fields[LAST_TEMP_0].lsb;
+
for (i = 0, j = VALID_0; i < priv->feat->max_sensors; i++, j++) {
priv->rf[j] = devm_regmap_field_alloc(dev, priv->tm_map,
priv->fields[j]);
diff --git a/drivers/thermal/qcom/tsens.h b/drivers/thermal/qcom/tsens.h
index e1d6af71b2b9a..409395e436f32 100644
--- a/drivers/thermal/qcom/tsens.h
+++ b/drivers/thermal/qcom/tsens.h
@@ -283,6 +283,7 @@ struct tsens_context {
* struct tsens_priv - private data for each instance of the tsens IP
* @dev: pointer to struct device
* @num_sensors: number of sensors enabled on this device
+ * @tempres: number of bits used to represent signed temperature (resolution)
* @tm_map: pointer to TM register address space
* @srot_map: pointer to SROT register address space
* @tm_offset: deal with old device trees that don't address TM and SROT
@@ -299,6 +300,7 @@ struct tsens_context {
struct tsens_priv {
struct device *dev;
u32 num_sensors;
+ u32 tempres;
struct regmap *tm_map;
struct regmap *srot_map;
u32 tm_offset;
--
2.17.1