[PATCH v3 11/13] thermal: qoriq: Do not report invalid temperature reading

From: Andrey Smirnov
Date: Mon Apr 01 2019 - 00:14:55 EST


Before returning measured temperature data to upper layer we need to
make sure that the reading was marked as "valid" to avoid reporting
bogus data.

Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
Cc: Chris Healy <cphealy@xxxxxxxxx>
Cc: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
Cc: Zhang Rui <rui.zhang@xxxxxxxxx>
Cc: Eduardo Valentin <edubezval@xxxxxxxxx>
Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Cc: Angus Ainslie (Purism) <angus@xxxxxxxx>
Cc: linux-imx@xxxxxxx
Cc: linux-pm@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
drivers/thermal/qoriq_thermal.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/thermal/qoriq_thermal.c b/drivers/thermal/qoriq_thermal.c
index 7ff93dfcd68b..9d227654f879 100644
--- a/drivers/thermal/qoriq_thermal.c
+++ b/drivers/thermal/qoriq_thermal.c
@@ -37,6 +37,7 @@
#define REGS_TRITSR(n) (0x100 + 16 * (n)) /* Immediate Temperature
* Site Register
*/
+#define TRITSR_V BIT(31)
#define REGS_TTRnCR(n) (0xf10 + 4 * (n)) /* Temperature Range n
* Control Register
*/
@@ -62,10 +63,18 @@ static int tmu_get_temp(void *p, int *temp)
struct qoriq_sensor *qsensor = p;
struct qoriq_tmu_data *qdata = qoriq_sensor_to_data(qsensor);
u32 val;
+ int ret;

- regmap_read(qdata->regmap, REGS_TRITSR(qsensor->id), &val);
- *temp = (val & 0xff) * 1000;
+ ret = regmap_read_poll_timeout(qdata->regmap,
+ REGS_TRITSR(qsensor->id),
+ val,
+ val & TRITSR_V,
+ USEC_PER_MSEC,
+ 10 * USEC_PER_MSEC);
+ if (ret)
+ return ret;

+ *temp = (val & 0xff) * 1000;
return 0;
}

--
2.20.1