diff --git a/drivers/thermal/qcom/tsens.c b/drivers/thermal/qcom/tsens.c index 5e19c7588e03..cf7fc0d57a54 100644 --- a/drivers/thermal/qcom/tsens.c +++ b/drivers/thermal/qcom/tsens.c @@ -316,9 +316,66 @@ static inline int code_to_degc(u32 adc_code, const struct tsens_sensor *s) } /** - * tsens_hw_to_mC - Return sign-extended temperature in mCelsius. + * tsens_read_temp - Retrieve temperature readings from the hardware. * @s: Pointer to sensor struct * @field: Index into regmap_field array pointing to temperature data + * @temp: temperature in deciCelsius to be read from hardware + * + * This function handles temperature returned in ADC code or deciCelsius + * depending on IP version. + * + * Return: 0 on success, a negative errno will be returned in error cases + */ +static int tsens_read_temp(const struct tsens_sensor *s, int field, int *temp) +{ + struct tsens_priv *priv = s->priv; + int temp_val[MAX_READ_RETRY] = {0}; + u32 status; + int ret; + u32 last_temp_mask = GENMASK(priv->fields[LAST_TEMP_0].msb, + priv->fields[LAST_TEMP_0].lsb); + u32 valid_bit = priv->rf[VALID_0] ? BIT(priv->fields[VALID_0].lsb) : 0; + + for (int i = 0; i < MAX_READ_RETRY; i++) { + ret = regmap_read(priv->tm_map, priv->fields[field].reg, &status); + if (ret) + return ret; + + /* VER_0 doesn't have a VALID bit */ + if (!valid_bit) { + *temp = status & last_temp_mask; + return 0; + } + + temp_val[i] = status & last_temp_mask; + + if (status & valid_bit) { + *temp = temp_val[i]; + return 0; + } + } + + /* + * As per the HW guidelines, if none of the attempts observe a + * valid sample, a stable fallback value must be returned. If the + * first and second samples match, the second value is returned; + * otherwise, if the second and third samples match, the third + * value is returned. + */ + if (temp_val[0] == temp_val[1]) + *temp = temp_val[1]; + else if (temp_val[1] == temp_val[2]) + *temp = temp_val[2]; + else + return -EAGAIN; + + return 0; +} + +/** + * tsens_hw_to_mC - Return sign-extended temperature in mCelsius. + * @s: Pointer to sensor struct + * @temp: temperature in milliCelsius to be read from hardware * * This function handles temperature returned in ADC code or deciCelsius * depending on IP version. @@ -326,20 +383,14 @@ static inline int code_to_degc(u32 adc_code, const struct tsens_sensor *s) * Return: Temperature in milliCelsius on success, a negative errno will * be returned in error cases */ -static int tsens_hw_to_mC(const struct tsens_sensor *s, int field) +static int tsens_hw_to_mC(const struct tsens_sensor *s, int temp) { struct tsens_priv *priv = s->priv; u32 resolution; - u32 temp = 0; - int ret; resolution = priv->fields[LAST_TEMP_0].msb - priv->fields[LAST_TEMP_0].lsb; - ret = regmap_field_read(priv->rf[field], &temp); - if (ret) - return ret; - /* Convert temperature from ADC code to milliCelsius */ if (priv->feat->adc) return code_to_degc(temp, s) * 1000; @@ -514,8 +565,10 @@ static int tsens_read_irq_state(struct tsens_priv *priv, u32 hw_id, &d->crit_irq_mask); if (ret) return ret; - - d->crit_thresh = tsens_hw_to_mC(s, CRIT_THRESH_0 + hw_id); + ret = regmap_field_read(priv->rf[CRIT_THRESH_0 + hw_id], &d->crit_thresh); + if (ret) + return ret; + d->crit_thresh = tsens_hw_to_mC(s, d->crit_thresh); } else { /* No mask register on older TSENS */ d->up_irq_mask = 0; @@ -525,8 +578,16 @@ static int tsens_read_irq_state(struct tsens_priv *priv, u32 hw_id, d->crit_thresh = 0; } - d->up_thresh = tsens_hw_to_mC(s, UP_THRESH_0 + hw_id); - d->low_thresh = tsens_hw_to_mC(s, LOW_THRESH_0 + hw_id); + ret = regmap_field_read(priv->rf[UP_THRESH_0 + hw_id], &d->up_thresh); + if (ret) + return ret; + + d->up_thresh = tsens_hw_to_mC(s, d->up_thresh); + ret = regmap_field_read(priv->rf[LOW_THRESH_0 + hw_id], &d->low_thresh); + if (ret) + return ret; + + d->low_thresh = tsens_hw_to_mC(s, d->low_thresh); dev_dbg(priv->dev, "[%u] %s%s: status(%u|%u|%u) | clr(%u|%u|%u) | mask(%u|%u|%u)\n", hw_id, __func__, @@ -750,33 +811,15 @@ static void tsens_disable_irq(struct tsens_priv *priv) int get_temp_tsens_valid(const 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 valid; int ret; - /* VER_0 doesn't have VALID bit */ - if (tsens_version(priv) == VER_0) - goto get_temp; + ret = tsens_read_temp(s, temp_idx, temp); + if (!ret) + *temp = tsens_hw_to_mC(s, *temp); - /* Valid bit is 0 for 6 AHB clock cycles. - * At 19.2MHz, 1 AHB clock is ~60ns. - * We should enter this loop very, very rarely. - * Wait 1 us since it's the min of poll_timeout macro. - * Old value was 400 ns. - */ - ret = regmap_field_read_poll_timeout(priv->rf[valid_idx], valid, - valid, 1, 20 * USEC_PER_MSEC); - if (ret) - return ret; - -get_temp: - /* Valid bit is set, OK to read the temperature */ - *temp = tsens_hw_to_mC(s, temp_idx); - - return 0; + return ret; } int get_temp_common(const struct tsens_sensor *s, int *temp) diff --git a/drivers/thermal/qcom/tsens.h b/drivers/thermal/qcom/tsens.h index 2a7afa4c899b..ab57ad88c3f7 100644 --- a/drivers/thermal/qcom/tsens.h +++ b/drivers/thermal/qcom/tsens.h @@ -21,6 +21,7 @@ #define THRESHOLD_MIN_ADC_CODE 0x0 #define MAX_SENSORS 16 +#define MAX_READ_RETRY 3 #include #include