drivers: thermal: tsens: Add new operation to check if a sensor is enabled

is_sensor_enabled() checks if the sensors are enabled on this platform.
It is possible that the SoC might choose not to enable all the sensors
that the IP block is capable of supporting.
Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

drivers/thermal/qcom/tsens-common.c

@@ -69,6 +69,20 @@ void compute_intercept_slope(struct tsens_priv *priv, u32 *p1,
 	}
 }
 
+bool is_sensor_enabled(struct tsens_priv *priv, u32 hw_id)
+{
+	u32 val;
+	int ret;
+
+	if ((hw_id > (priv->num_sensors - 1)) || (hw_id < 0))
+		return -EINVAL;
+	ret = regmap_field_read(priv->rf[SENSOR_EN], &val);
+	if (ret)
+		return ret;
+
+	return val & (1 << hw_id);
+}
+
 static inline int code_to_degc(u32 adc_code, const struct tsens_sensor *s)
 {
 	int degc, num, den;

drivers/thermal/qcom/tsens-v0_1.c

@@ -333,6 +333,7 @@ static const struct reg_field tsens_v0_1_regfields[MAX_REGFIELDS] = {
 	/* CTRL_OFFSET */
 	[TSENS_EN]     = REG_FIELD(SROT_CTRL_OFF, 0,  0),
 	[TSENS_SW_RST] = REG_FIELD(SROT_CTRL_OFF, 1,  1),
+	[SENSOR_EN]    = REG_FIELD(SROT_CTRL_OFF, 3, 13),
 
 	/* ----- TM ------ */
 	/* INTERRUPT ENABLE */

drivers/thermal/qcom/tsens-v2.c

@@ -99,6 +99,7 @@ static const struct reg_field tsens_v2_regfields[MAX_REGFIELDS] = {
 	/* CTRL_OFF */
 	[TSENS_EN]     = REG_FIELD(SROT_CTRL_OFF,    0,  0),
 	[TSENS_SW_RST] = REG_FIELD(SROT_CTRL_OFF,    1,  1),
+	[SENSOR_EN]    = REG_FIELD(SROT_CTRL_OFF,    3, 18),
 
 	/* ----- TM ------ */
 	/* INTERRUPT ENABLE */

drivers/thermal/qcom/tsens.c

@@ -82,6 +82,11 @@ static int tsens_register(struct tsens_priv *priv)
 	struct thermal_zone_device *tzd;
 
 	for (i = 0;  i < priv->num_sensors; i++) {
+		if (!is_sensor_enabled(priv, priv->sensor[i].hw_id)) {
+			dev_err(priv->dev, "sensor %d: disabled\n",
+				priv->sensor[i].hw_id);
+			continue;
+		}
 		priv->sensor[i].priv = priv;
 		priv->sensor[i].id = i;
 		tzd = devm_thermal_zone_of_sensor_register(priv->dev, i,

drivers/thermal/qcom/tsens.h

@@ -307,6 +307,7 @@ char *qfprom_read(struct device *dev, const char *cname);
 void compute_intercept_slope(struct tsens_priv *priv, u32 *pt1, u32 *pt2, u32 mode);
 int init_common(struct tsens_priv *priv);
 int get_temp_common(struct tsens_priv *priv, int i, int *temp);
+bool is_sensor_enabled(struct tsens_priv *priv, u32 hw_id);
 
 /* TSENS target */
 extern const struct tsens_plat_data data_8960;