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authorJ Keerthy <j-keerthy@ti.com>2013-04-01 12:04:45 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-04-01 12:27:30 -0700
commit2f440b0622085a130ff723bb037066c9cbfc8cd7 (patch)
tree6a0b049ca925f4d16cdddb51a8f30057a9645ec5 /drivers/staging/ti-soc-thermal
parent54b59c922400bf1ef16dee4834a4a5722552176e (diff)
downloadlinux-2f440b0622085a130ff723bb037066c9cbfc8cd7.tar.gz
staging: ti-soc-thermal:Introduce ti_bandgap_get_trend function for OMAP5
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@ti.com> Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/ti-soc-thermal')
-rw-r--r--drivers/staging/ti-soc-thermal/ti-bandgap.c67
-rw-r--r--drivers/staging/ti-soc-thermal/ti-bandgap.h1
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 cc0c4ba9eaa..5b06b12ae91 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 e29e357fd19..5f4794abf58 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;