From: J Keerthy <j-keerthy@xxxxxx>
The patch adds ti_bandgap_get_trend function. This is specific
to OMAP5 for now it computes the trend from the temp values stored
in the hardware history buffer.
Formula: (T1 - T2) / P.
Where:
T1: Last read valid temperature.
T2: Last but one read valid temperature.
P: Update Interval.
Signed-off-by: J Keerthy <j-keerthy@xxxxxx>
Signed-off-by: Eduardo Valentin <eduardo.valentin@xxxxxx>
---
drivers/staging/ti-soc-thermal/ti-bandgap.c | 67 +++++++++++++++++++++++++++
drivers/staging/ti-soc-thermal/ti-bandgap.h | 1 +
2 files changed, 68 insertions(+), 0 deletions(-)
diff --git a/drivers/staging/ti-soc-thermal/ti-bandgap.c b/drivers/staging/ti-soc-thermal/ti-bandgap.c
index cc0c4ba..5b06b12 100644
--- a/drivers/staging/ti-soc-thermal/ti-bandgap.c
+++ b/drivers/staging/ti-soc-thermal/ti-bandgap.c
@@ -962,6 +962,73 @@ static int ti_bandgap_set_continuous_mode(struct ti_bandgap *bgp)
}
/**
+ * ti_bandgap_get_trend() - To fetch the temperature trend of a sensor
+ * @bgp: pointer to struct ti_bandgap
+ * @id: id of the individual sensor
+ * @trend: Pointer to trend.
+ *
+ * This function needs to be called to fetch the temperature trend of a
+ * Particular sensor. The function computes the difference in temperature
+ * w.r.t time. For the bandgaps with built in history buffer the temperatures
+ * are read from the buffer and for those without the Buffer -ENOTSUPP is
+ * returned.
+ *
+ * Return: 0 if no error, else return corresponding error. If no
+ * error then the trend value is passed on to trend parameter
+ */
+int ti_bandgap_get_trend(struct ti_bandgap *bgp, int id, int *trend)
+{
+ struct temp_sensor_registers *tsr;
+ u32 temp1, temp2, reg1, reg2;
+ int t1, t2, interval, ret = 0;
+
+ ret = ti_bandgap_validate(bgp, id);
+ if (ret)
+ goto exit;
+
+ if (!TI_BANDGAP_HAS(bgp, HISTORY_BUFFER) ||
+ !TI_BANDGAP_HAS(bgp, FREEZE_BIT)) {
+ ret = -ENOTSUPP;
+ goto exit;
+ }
+
+ tsr = bgp->conf->sensors[id].registers;
+
+ /* Freeze and read the last 2 valid readings */
+ reg1 = tsr->ctrl_dtemp_1;
+ reg2 = tsr->ctrl_dtemp_2;
+
+ /* read temperature from history buffer */
+ temp1 = ti_bandgap_readl(bgp, reg1);
+ temp1 &= tsr->bgap_dtemp_mask;
+
+ temp2 = ti_bandgap_readl(bgp, reg2);
+ temp2 &= tsr->bgap_dtemp_mask;
+
+ /* Convert from adc values to mCelsius temperature */
+ ret = ti_bandgap_adc_to_mcelsius(bgp, temp1, &t1);
+ if (ret)
+ goto exit;
+
+ ret = ti_bandgap_adc_to_mcelsius(bgp, temp2, &t2);
+ if (ret)
+ goto exit;
+
+ /* Fetch the update interval */
+ ret = ti_bandgap_read_update_interval(bgp, id, &interval);
+ if (ret || !interval)
+ goto exit;
+
+ *trend = (t1 - t2) / interval;
+
+ dev_dbg(bgp->dev, "The temperatures are t1 = %d and t2 = %d and trend =%d\n",
+ t1, t2, *trend);
+
+exit:
+ return ret;
+}
+
+/**
* ti_bandgap_tshut_init() - setup and initialize tshut handling
* @bgp: pointer to struct ti_bandgap
* @pdev: pointer to device struct platform_device
diff --git a/drivers/staging/ti-soc-thermal/ti-bandgap.h b/drivers/staging/ti-soc-thermal/ti-bandgap.h
index e29e357..5f4794a 100644
--- a/drivers/staging/ti-soc-thermal/ti-bandgap.h
+++ b/drivers/staging/ti-soc-thermal/ti-bandgap.h
@@ -382,6 +382,7 @@ int ti_bandgap_read_temperature(struct ti_bandgap *bgp, int id,
int *temperature);
int ti_bandgap_set_sensor_data(struct ti_bandgap *bgp, int id, void *data);
void *ti_bandgap_get_sensor_data(struct ti_bandgap *bgp, int id);
+int ti_bandgap_get_trend(struct ti_bandgap *bgp, int id, int *trend);
#ifdef CONFIG_OMAP4_THERMAL
extern const struct ti_bandgap_data omap4430_data;
--
1.7.7.1.488.ge8e1c
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